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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * PCI Bus Services, see include/linux/pci.h for further explanation.
4 *
5 * Copyright 1993 -- 1997 Drew Eckhardt, Frederic Potter,
6 * David Mosberger-Tang
7 *
8 * Copyright 1997 -- 2000 Martin Mares <mj@ucw.cz>
9 */
10
11#include <linux/acpi.h>
12#include <linux/kernel.h>
13#include <linux/delay.h>
14#include <linux/dmi.h>
15#include <linux/init.h>
16#include <linux/msi.h>
17#include <linux/of.h>
18#include <linux/pci.h>
19#include <linux/pm.h>
20#include <linux/slab.h>
21#include <linux/module.h>
22#include <linux/spinlock.h>
23#include <linux/string.h>
24#include <linux/log2.h>
25#include <linux/logic_pio.h>
26#include <linux/pm_wakeup.h>
27#include <linux/interrupt.h>
28#include <linux/device.h>
29#include <linux/pm_runtime.h>
30#include <linux/pci_hotplug.h>
31#include <linux/vmalloc.h>
32#include <asm/dma.h>
33#include <linux/aer.h>
34#include <linux/bitfield.h>
35#include "pci.h"
36
37DEFINE_MUTEX(pci_slot_mutex);
38
39const char *pci_power_names[] = {
40 "error", "D0", "D1", "D2", "D3hot", "D3cold", "unknown",
41};
42EXPORT_SYMBOL_GPL(pci_power_names);
43
44#ifdef CONFIG_X86_32
45int isa_dma_bridge_buggy;
46EXPORT_SYMBOL(isa_dma_bridge_buggy);
47#endif
48
49int pci_pci_problems;
50EXPORT_SYMBOL(pci_pci_problems);
51
52unsigned int pci_pm_d3hot_delay;
53
54static void pci_pme_list_scan(struct work_struct *work);
55
56static LIST_HEAD(pci_pme_list);
57static DEFINE_MUTEX(pci_pme_list_mutex);
58static DECLARE_DELAYED_WORK(pci_pme_work, pci_pme_list_scan);
59
60struct pci_pme_device {
61 struct list_head list;
62 struct pci_dev *dev;
63};
64
65#define PME_TIMEOUT 1000 /* How long between PME checks */
66
67static void pci_dev_d3_sleep(struct pci_dev *dev)
68{
69 unsigned int delay_ms = max(dev->d3hot_delay, pci_pm_d3hot_delay);
70 unsigned int upper;
71
72 if (delay_ms) {
73 /* Use a 20% upper bound, 1ms minimum */
74 upper = max(DIV_ROUND_CLOSEST(delay_ms, 5), 1U);
75 usleep_range(delay_ms * USEC_PER_MSEC,
76 (delay_ms + upper) * USEC_PER_MSEC);
77 }
78}
79
80bool pci_reset_supported(struct pci_dev *dev)
81{
82 return dev->reset_methods[0] != 0;
83}
84
85#ifdef CONFIG_PCI_DOMAINS
86int pci_domains_supported = 1;
87#endif
88
89#define DEFAULT_CARDBUS_IO_SIZE (256)
90#define DEFAULT_CARDBUS_MEM_SIZE (64*1024*1024)
91/* pci=cbmemsize=nnM,cbiosize=nn can override this */
92unsigned long pci_cardbus_io_size = DEFAULT_CARDBUS_IO_SIZE;
93unsigned long pci_cardbus_mem_size = DEFAULT_CARDBUS_MEM_SIZE;
94
95#define DEFAULT_HOTPLUG_IO_SIZE (256)
96#define DEFAULT_HOTPLUG_MMIO_SIZE (2*1024*1024)
97#define DEFAULT_HOTPLUG_MMIO_PREF_SIZE (2*1024*1024)
98/* hpiosize=nn can override this */
99unsigned long pci_hotplug_io_size = DEFAULT_HOTPLUG_IO_SIZE;
100/*
101 * pci=hpmmiosize=nnM overrides non-prefetchable MMIO size,
102 * pci=hpmmioprefsize=nnM overrides prefetchable MMIO size;
103 * pci=hpmemsize=nnM overrides both
104 */
105unsigned long pci_hotplug_mmio_size = DEFAULT_HOTPLUG_MMIO_SIZE;
106unsigned long pci_hotplug_mmio_pref_size = DEFAULT_HOTPLUG_MMIO_PREF_SIZE;
107
108#define DEFAULT_HOTPLUG_BUS_SIZE 1
109unsigned long pci_hotplug_bus_size = DEFAULT_HOTPLUG_BUS_SIZE;
110
111
112/* PCIe MPS/MRRS strategy; can be overridden by kernel command-line param */
113#ifdef CONFIG_PCIE_BUS_TUNE_OFF
114enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_TUNE_OFF;
115#elif defined CONFIG_PCIE_BUS_SAFE
116enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_SAFE;
117#elif defined CONFIG_PCIE_BUS_PERFORMANCE
118enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_PERFORMANCE;
119#elif defined CONFIG_PCIE_BUS_PEER2PEER
120enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_PEER2PEER;
121#else
122enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_DEFAULT;
123#endif
124
125/*
126 * The default CLS is used if arch didn't set CLS explicitly and not
127 * all pci devices agree on the same value. Arch can override either
128 * the dfl or actual value as it sees fit. Don't forget this is
129 * measured in 32-bit words, not bytes.
130 */
131u8 pci_dfl_cache_line_size = L1_CACHE_BYTES >> 2;
132u8 pci_cache_line_size;
133
134/*
135 * If we set up a device for bus mastering, we need to check the latency
136 * timer as certain BIOSes forget to set it properly.
137 */
138unsigned int pcibios_max_latency = 255;
139
140/* If set, the PCIe ARI capability will not be used. */
141static bool pcie_ari_disabled;
142
143/* If set, the PCIe ATS capability will not be used. */
144static bool pcie_ats_disabled;
145
146/* If set, the PCI config space of each device is printed during boot. */
147bool pci_early_dump;
148
149bool pci_ats_disabled(void)
150{
151 return pcie_ats_disabled;
152}
153EXPORT_SYMBOL_GPL(pci_ats_disabled);
154
155/* Disable bridge_d3 for all PCIe ports */
156static bool pci_bridge_d3_disable;
157/* Force bridge_d3 for all PCIe ports */
158static bool pci_bridge_d3_force;
159
160static int __init pcie_port_pm_setup(char *str)
161{
162 if (!strcmp(str, "off"))
163 pci_bridge_d3_disable = true;
164 else if (!strcmp(str, "force"))
165 pci_bridge_d3_force = true;
166 return 1;
167}
168__setup("pcie_port_pm=", pcie_port_pm_setup);
169
170/* Time to wait after a reset for device to become responsive */
171#define PCIE_RESET_READY_POLL_MS 60000
172
173/**
174 * pci_bus_max_busnr - returns maximum PCI bus number of given bus' children
175 * @bus: pointer to PCI bus structure to search
176 *
177 * Given a PCI bus, returns the highest PCI bus number present in the set
178 * including the given PCI bus and its list of child PCI buses.
179 */
180unsigned char pci_bus_max_busnr(struct pci_bus *bus)
181{
182 struct pci_bus *tmp;
183 unsigned char max, n;
184
185 max = bus->busn_res.end;
186 list_for_each_entry(tmp, &bus->children, node) {
187 n = pci_bus_max_busnr(tmp);
188 if (n > max)
189 max = n;
190 }
191 return max;
192}
193EXPORT_SYMBOL_GPL(pci_bus_max_busnr);
194
195/**
196 * pci_status_get_and_clear_errors - return and clear error bits in PCI_STATUS
197 * @pdev: the PCI device
198 *
199 * Returns error bits set in PCI_STATUS and clears them.
200 */
201int pci_status_get_and_clear_errors(struct pci_dev *pdev)
202{
203 u16 status;
204 int ret;
205
206 ret = pci_read_config_word(pdev, PCI_STATUS, &status);
207 if (ret != PCIBIOS_SUCCESSFUL)
208 return -EIO;
209
210 status &= PCI_STATUS_ERROR_BITS;
211 if (status)
212 pci_write_config_word(pdev, PCI_STATUS, status);
213
214 return status;
215}
216EXPORT_SYMBOL_GPL(pci_status_get_and_clear_errors);
217
218#ifdef CONFIG_HAS_IOMEM
219static void __iomem *__pci_ioremap_resource(struct pci_dev *pdev, int bar,
220 bool write_combine)
221{
222 struct resource *res = &pdev->resource[bar];
223 resource_size_t start = res->start;
224 resource_size_t size = resource_size(res);
225
226 /*
227 * Make sure the BAR is actually a memory resource, not an IO resource
228 */
229 if (res->flags & IORESOURCE_UNSET || !(res->flags & IORESOURCE_MEM)) {
230 pci_err(pdev, "can't ioremap BAR %d: %pR\n", bar, res);
231 return NULL;
232 }
233
234 if (write_combine)
235 return ioremap_wc(start, size);
236
237 return ioremap(start, size);
238}
239
240void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar)
241{
242 return __pci_ioremap_resource(pdev, bar, false);
243}
244EXPORT_SYMBOL_GPL(pci_ioremap_bar);
245
246void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar)
247{
248 return __pci_ioremap_resource(pdev, bar, true);
249}
250EXPORT_SYMBOL_GPL(pci_ioremap_wc_bar);
251#endif
252
253/**
254 * pci_dev_str_match_path - test if a path string matches a device
255 * @dev: the PCI device to test
256 * @path: string to match the device against
257 * @endptr: pointer to the string after the match
258 *
259 * Test if a string (typically from a kernel parameter) formatted as a
260 * path of device/function addresses matches a PCI device. The string must
261 * be of the form:
262 *
263 * [<domain>:]<bus>:<device>.<func>[/<device>.<func>]*
264 *
265 * A path for a device can be obtained using 'lspci -t'. Using a path
266 * is more robust against bus renumbering than using only a single bus,
267 * device and function address.
268 *
269 * Returns 1 if the string matches the device, 0 if it does not and
270 * a negative error code if it fails to parse the string.
271 */
272static int pci_dev_str_match_path(struct pci_dev *dev, const char *path,
273 const char **endptr)
274{
275 int ret;
276 unsigned int seg, bus, slot, func;
277 char *wpath, *p;
278 char end;
279
280 *endptr = strchrnul(path, ';');
281
282 wpath = kmemdup_nul(path, *endptr - path, GFP_ATOMIC);
283 if (!wpath)
284 return -ENOMEM;
285
286 while (1) {
287 p = strrchr(wpath, '/');
288 if (!p)
289 break;
290 ret = sscanf(p, "/%x.%x%c", &slot, &func, &end);
291 if (ret != 2) {
292 ret = -EINVAL;
293 goto free_and_exit;
294 }
295
296 if (dev->devfn != PCI_DEVFN(slot, func)) {
297 ret = 0;
298 goto free_and_exit;
299 }
300
301 /*
302 * Note: we don't need to get a reference to the upstream
303 * bridge because we hold a reference to the top level
304 * device which should hold a reference to the bridge,
305 * and so on.
306 */
307 dev = pci_upstream_bridge(dev);
308 if (!dev) {
309 ret = 0;
310 goto free_and_exit;
311 }
312
313 *p = 0;
314 }
315
316 ret = sscanf(wpath, "%x:%x:%x.%x%c", &seg, &bus, &slot,
317 &func, &end);
318 if (ret != 4) {
319 seg = 0;
320 ret = sscanf(wpath, "%x:%x.%x%c", &bus, &slot, &func, &end);
321 if (ret != 3) {
322 ret = -EINVAL;
323 goto free_and_exit;
324 }
325 }
326
327 ret = (seg == pci_domain_nr(dev->bus) &&
328 bus == dev->bus->number &&
329 dev->devfn == PCI_DEVFN(slot, func));
330
331free_and_exit:
332 kfree(wpath);
333 return ret;
334}
335
336/**
337 * pci_dev_str_match - test if a string matches a device
338 * @dev: the PCI device to test
339 * @p: string to match the device against
340 * @endptr: pointer to the string after the match
341 *
342 * Test if a string (typically from a kernel parameter) matches a specified
343 * PCI device. The string may be of one of the following formats:
344 *
345 * [<domain>:]<bus>:<device>.<func>[/<device>.<func>]*
346 * pci:<vendor>:<device>[:<subvendor>:<subdevice>]
347 *
348 * The first format specifies a PCI bus/device/function address which
349 * may change if new hardware is inserted, if motherboard firmware changes,
350 * or due to changes caused in kernel parameters. If the domain is
351 * left unspecified, it is taken to be 0. In order to be robust against
352 * bus renumbering issues, a path of PCI device/function numbers may be used
353 * to address the specific device. The path for a device can be determined
354 * through the use of 'lspci -t'.
355 *
356 * The second format matches devices using IDs in the configuration
357 * space which may match multiple devices in the system. A value of 0
358 * for any field will match all devices. (Note: this differs from
359 * in-kernel code that uses PCI_ANY_ID which is ~0; this is for
360 * legacy reasons and convenience so users don't have to specify
361 * FFFFFFFFs on the command line.)
362 *
363 * Returns 1 if the string matches the device, 0 if it does not and
364 * a negative error code if the string cannot be parsed.
365 */
366static int pci_dev_str_match(struct pci_dev *dev, const char *p,
367 const char **endptr)
368{
369 int ret;
370 int count;
371 unsigned short vendor, device, subsystem_vendor, subsystem_device;
372
373 if (strncmp(p, "pci:", 4) == 0) {
374 /* PCI vendor/device (subvendor/subdevice) IDs are specified */
375 p += 4;
376 ret = sscanf(p, "%hx:%hx:%hx:%hx%n", &vendor, &device,
377 &subsystem_vendor, &subsystem_device, &count);
378 if (ret != 4) {
379 ret = sscanf(p, "%hx:%hx%n", &vendor, &device, &count);
380 if (ret != 2)
381 return -EINVAL;
382
383 subsystem_vendor = 0;
384 subsystem_device = 0;
385 }
386
387 p += count;
388
389 if ((!vendor || vendor == dev->vendor) &&
390 (!device || device == dev->device) &&
391 (!subsystem_vendor ||
392 subsystem_vendor == dev->subsystem_vendor) &&
393 (!subsystem_device ||
394 subsystem_device == dev->subsystem_device))
395 goto found;
396 } else {
397 /*
398 * PCI Bus, Device, Function IDs are specified
399 * (optionally, may include a path of devfns following it)
400 */
401 ret = pci_dev_str_match_path(dev, p, &p);
402 if (ret < 0)
403 return ret;
404 else if (ret)
405 goto found;
406 }
407
408 *endptr = p;
409 return 0;
410
411found:
412 *endptr = p;
413 return 1;
414}
415
416static u8 __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn,
417 u8 pos, int cap, int *ttl)
418{
419 u8 id;
420 u16 ent;
421
422 pci_bus_read_config_byte(bus, devfn, pos, &pos);
423
424 while ((*ttl)--) {
425 if (pos < 0x40)
426 break;
427 pos &= ~3;
428 pci_bus_read_config_word(bus, devfn, pos, &ent);
429
430 id = ent & 0xff;
431 if (id == 0xff)
432 break;
433 if (id == cap)
434 return pos;
435 pos = (ent >> 8);
436 }
437 return 0;
438}
439
440static u8 __pci_find_next_cap(struct pci_bus *bus, unsigned int devfn,
441 u8 pos, int cap)
442{
443 int ttl = PCI_FIND_CAP_TTL;
444
445 return __pci_find_next_cap_ttl(bus, devfn, pos, cap, &ttl);
446}
447
448u8 pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap)
449{
450 return __pci_find_next_cap(dev->bus, dev->devfn,
451 pos + PCI_CAP_LIST_NEXT, cap);
452}
453EXPORT_SYMBOL_GPL(pci_find_next_capability);
454
455static u8 __pci_bus_find_cap_start(struct pci_bus *bus,
456 unsigned int devfn, u8 hdr_type)
457{
458 u16 status;
459
460 pci_bus_read_config_word(bus, devfn, PCI_STATUS, &status);
461 if (!(status & PCI_STATUS_CAP_LIST))
462 return 0;
463
464 switch (hdr_type) {
465 case PCI_HEADER_TYPE_NORMAL:
466 case PCI_HEADER_TYPE_BRIDGE:
467 return PCI_CAPABILITY_LIST;
468 case PCI_HEADER_TYPE_CARDBUS:
469 return PCI_CB_CAPABILITY_LIST;
470 }
471
472 return 0;
473}
474
475/**
476 * pci_find_capability - query for devices' capabilities
477 * @dev: PCI device to query
478 * @cap: capability code
479 *
480 * Tell if a device supports a given PCI capability.
481 * Returns the address of the requested capability structure within the
482 * device's PCI configuration space or 0 in case the device does not
483 * support it. Possible values for @cap include:
484 *
485 * %PCI_CAP_ID_PM Power Management
486 * %PCI_CAP_ID_AGP Accelerated Graphics Port
487 * %PCI_CAP_ID_VPD Vital Product Data
488 * %PCI_CAP_ID_SLOTID Slot Identification
489 * %PCI_CAP_ID_MSI Message Signalled Interrupts
490 * %PCI_CAP_ID_CHSWP CompactPCI HotSwap
491 * %PCI_CAP_ID_PCIX PCI-X
492 * %PCI_CAP_ID_EXP PCI Express
493 */
494u8 pci_find_capability(struct pci_dev *dev, int cap)
495{
496 u8 pos;
497
498 pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);
499 if (pos)
500 pos = __pci_find_next_cap(dev->bus, dev->devfn, pos, cap);
501
502 return pos;
503}
504EXPORT_SYMBOL(pci_find_capability);
505
506/**
507 * pci_bus_find_capability - query for devices' capabilities
508 * @bus: the PCI bus to query
509 * @devfn: PCI device to query
510 * @cap: capability code
511 *
512 * Like pci_find_capability() but works for PCI devices that do not have a
513 * pci_dev structure set up yet.
514 *
515 * Returns the address of the requested capability structure within the
516 * device's PCI configuration space or 0 in case the device does not
517 * support it.
518 */
519u8 pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap)
520{
521 u8 hdr_type, pos;
522
523 pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &hdr_type);
524
525 pos = __pci_bus_find_cap_start(bus, devfn, hdr_type & 0x7f);
526 if (pos)
527 pos = __pci_find_next_cap(bus, devfn, pos, cap);
528
529 return pos;
530}
531EXPORT_SYMBOL(pci_bus_find_capability);
532
533/**
534 * pci_find_next_ext_capability - Find an extended capability
535 * @dev: PCI device to query
536 * @start: address at which to start looking (0 to start at beginning of list)
537 * @cap: capability code
538 *
539 * Returns the address of the next matching extended capability structure
540 * within the device's PCI configuration space or 0 if the device does
541 * not support it. Some capabilities can occur several times, e.g., the
542 * vendor-specific capability, and this provides a way to find them all.
543 */
544u16 pci_find_next_ext_capability(struct pci_dev *dev, u16 start, int cap)
545{
546 u32 header;
547 int ttl;
548 u16 pos = PCI_CFG_SPACE_SIZE;
549
550 /* minimum 8 bytes per capability */
551 ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8;
552
553 if (dev->cfg_size <= PCI_CFG_SPACE_SIZE)
554 return 0;
555
556 if (start)
557 pos = start;
558
559 if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
560 return 0;
561
562 /*
563 * If we have no capabilities, this is indicated by cap ID,
564 * cap version and next pointer all being 0.
565 */
566 if (header == 0)
567 return 0;
568
569 while (ttl-- > 0) {
570 if (PCI_EXT_CAP_ID(header) == cap && pos != start)
571 return pos;
572
573 pos = PCI_EXT_CAP_NEXT(header);
574 if (pos < PCI_CFG_SPACE_SIZE)
575 break;
576
577 if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
578 break;
579 }
580
581 return 0;
582}
583EXPORT_SYMBOL_GPL(pci_find_next_ext_capability);
584
585/**
586 * pci_find_ext_capability - Find an extended capability
587 * @dev: PCI device to query
588 * @cap: capability code
589 *
590 * Returns the address of the requested extended capability structure
591 * within the device's PCI configuration space or 0 if the device does
592 * not support it. Possible values for @cap include:
593 *
594 * %PCI_EXT_CAP_ID_ERR Advanced Error Reporting
595 * %PCI_EXT_CAP_ID_VC Virtual Channel
596 * %PCI_EXT_CAP_ID_DSN Device Serial Number
597 * %PCI_EXT_CAP_ID_PWR Power Budgeting
598 */
599u16 pci_find_ext_capability(struct pci_dev *dev, int cap)
600{
601 return pci_find_next_ext_capability(dev, 0, cap);
602}
603EXPORT_SYMBOL_GPL(pci_find_ext_capability);
604
605/**
606 * pci_get_dsn - Read and return the 8-byte Device Serial Number
607 * @dev: PCI device to query
608 *
609 * Looks up the PCI_EXT_CAP_ID_DSN and reads the 8 bytes of the Device Serial
610 * Number.
611 *
612 * Returns the DSN, or zero if the capability does not exist.
613 */
614u64 pci_get_dsn(struct pci_dev *dev)
615{
616 u32 dword;
617 u64 dsn;
618 int pos;
619
620 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DSN);
621 if (!pos)
622 return 0;
623
624 /*
625 * The Device Serial Number is two dwords offset 4 bytes from the
626 * capability position. The specification says that the first dword is
627 * the lower half, and the second dword is the upper half.
628 */
629 pos += 4;
630 pci_read_config_dword(dev, pos, &dword);
631 dsn = (u64)dword;
632 pci_read_config_dword(dev, pos + 4, &dword);
633 dsn |= ((u64)dword) << 32;
634
635 return dsn;
636}
637EXPORT_SYMBOL_GPL(pci_get_dsn);
638
639static u8 __pci_find_next_ht_cap(struct pci_dev *dev, u8 pos, int ht_cap)
640{
641 int rc, ttl = PCI_FIND_CAP_TTL;
642 u8 cap, mask;
643
644 if (ht_cap == HT_CAPTYPE_SLAVE || ht_cap == HT_CAPTYPE_HOST)
645 mask = HT_3BIT_CAP_MASK;
646 else
647 mask = HT_5BIT_CAP_MASK;
648
649 pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn, pos,
650 PCI_CAP_ID_HT, &ttl);
651 while (pos) {
652 rc = pci_read_config_byte(dev, pos + 3, &cap);
653 if (rc != PCIBIOS_SUCCESSFUL)
654 return 0;
655
656 if ((cap & mask) == ht_cap)
657 return pos;
658
659 pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn,
660 pos + PCI_CAP_LIST_NEXT,
661 PCI_CAP_ID_HT, &ttl);
662 }
663
664 return 0;
665}
666
667/**
668 * pci_find_next_ht_capability - query a device's HyperTransport capabilities
669 * @dev: PCI device to query
670 * @pos: Position from which to continue searching
671 * @ht_cap: HyperTransport capability code
672 *
673 * To be used in conjunction with pci_find_ht_capability() to search for
674 * all capabilities matching @ht_cap. @pos should always be a value returned
675 * from pci_find_ht_capability().
676 *
677 * NB. To be 100% safe against broken PCI devices, the caller should take
678 * steps to avoid an infinite loop.
679 */
680u8 pci_find_next_ht_capability(struct pci_dev *dev, u8 pos, int ht_cap)
681{
682 return __pci_find_next_ht_cap(dev, pos + PCI_CAP_LIST_NEXT, ht_cap);
683}
684EXPORT_SYMBOL_GPL(pci_find_next_ht_capability);
685
686/**
687 * pci_find_ht_capability - query a device's HyperTransport capabilities
688 * @dev: PCI device to query
689 * @ht_cap: HyperTransport capability code
690 *
691 * Tell if a device supports a given HyperTransport capability.
692 * Returns an address within the device's PCI configuration space
693 * or 0 in case the device does not support the request capability.
694 * The address points to the PCI capability, of type PCI_CAP_ID_HT,
695 * which has a HyperTransport capability matching @ht_cap.
696 */
697u8 pci_find_ht_capability(struct pci_dev *dev, int ht_cap)
698{
699 u8 pos;
700
701 pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);
702 if (pos)
703 pos = __pci_find_next_ht_cap(dev, pos, ht_cap);
704
705 return pos;
706}
707EXPORT_SYMBOL_GPL(pci_find_ht_capability);
708
709/**
710 * pci_find_vsec_capability - Find a vendor-specific extended capability
711 * @dev: PCI device to query
712 * @vendor: Vendor ID for which capability is defined
713 * @cap: Vendor-specific capability ID
714 *
715 * If @dev has Vendor ID @vendor, search for a VSEC capability with
716 * VSEC ID @cap. If found, return the capability offset in
717 * config space; otherwise return 0.
718 */
719u16 pci_find_vsec_capability(struct pci_dev *dev, u16 vendor, int cap)
720{
721 u16 vsec = 0;
722 u32 header;
723
724 if (vendor != dev->vendor)
725 return 0;
726
727 while ((vsec = pci_find_next_ext_capability(dev, vsec,
728 PCI_EXT_CAP_ID_VNDR))) {
729 if (pci_read_config_dword(dev, vsec + PCI_VNDR_HEADER,
730 &header) == PCIBIOS_SUCCESSFUL &&
731 PCI_VNDR_HEADER_ID(header) == cap)
732 return vsec;
733 }
734
735 return 0;
736}
737EXPORT_SYMBOL_GPL(pci_find_vsec_capability);
738
739/**
740 * pci_find_dvsec_capability - Find DVSEC for vendor
741 * @dev: PCI device to query
742 * @vendor: Vendor ID to match for the DVSEC
743 * @dvsec: Designated Vendor-specific capability ID
744 *
745 * If DVSEC has Vendor ID @vendor and DVSEC ID @dvsec return the capability
746 * offset in config space; otherwise return 0.
747 */
748u16 pci_find_dvsec_capability(struct pci_dev *dev, u16 vendor, u16 dvsec)
749{
750 int pos;
751
752 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DVSEC);
753 if (!pos)
754 return 0;
755
756 while (pos) {
757 u16 v, id;
758
759 pci_read_config_word(dev, pos + PCI_DVSEC_HEADER1, &v);
760 pci_read_config_word(dev, pos + PCI_DVSEC_HEADER2, &id);
761 if (vendor == v && dvsec == id)
762 return pos;
763
764 pos = pci_find_next_ext_capability(dev, pos, PCI_EXT_CAP_ID_DVSEC);
765 }
766
767 return 0;
768}
769EXPORT_SYMBOL_GPL(pci_find_dvsec_capability);
770
771/**
772 * pci_find_parent_resource - return resource region of parent bus of given
773 * region
774 * @dev: PCI device structure contains resources to be searched
775 * @res: child resource record for which parent is sought
776 *
777 * For given resource region of given device, return the resource region of
778 * parent bus the given region is contained in.
779 */
780struct resource *pci_find_parent_resource(const struct pci_dev *dev,
781 struct resource *res)
782{
783 const struct pci_bus *bus = dev->bus;
784 struct resource *r;
785 int i;
786
787 pci_bus_for_each_resource(bus, r, i) {
788 if (!r)
789 continue;
790 if (resource_contains(r, res)) {
791
792 /*
793 * If the window is prefetchable but the BAR is
794 * not, the allocator made a mistake.
795 */
796 if (r->flags & IORESOURCE_PREFETCH &&
797 !(res->flags & IORESOURCE_PREFETCH))
798 return NULL;
799
800 /*
801 * If we're below a transparent bridge, there may
802 * be both a positively-decoded aperture and a
803 * subtractively-decoded region that contain the BAR.
804 * We want the positively-decoded one, so this depends
805 * on pci_bus_for_each_resource() giving us those
806 * first.
807 */
808 return r;
809 }
810 }
811 return NULL;
812}
813EXPORT_SYMBOL(pci_find_parent_resource);
814
815/**
816 * pci_find_resource - Return matching PCI device resource
817 * @dev: PCI device to query
818 * @res: Resource to look for
819 *
820 * Goes over standard PCI resources (BARs) and checks if the given resource
821 * is partially or fully contained in any of them. In that case the
822 * matching resource is returned, %NULL otherwise.
823 */
824struct resource *pci_find_resource(struct pci_dev *dev, struct resource *res)
825{
826 int i;
827
828 for (i = 0; i < PCI_STD_NUM_BARS; i++) {
829 struct resource *r = &dev->resource[i];
830
831 if (r->start && resource_contains(r, res))
832 return r;
833 }
834
835 return NULL;
836}
837EXPORT_SYMBOL(pci_find_resource);
838
839/**
840 * pci_wait_for_pending - wait for @mask bit(s) to clear in status word @pos
841 * @dev: the PCI device to operate on
842 * @pos: config space offset of status word
843 * @mask: mask of bit(s) to care about in status word
844 *
845 * Return 1 when mask bit(s) in status word clear, 0 otherwise.
846 */
847int pci_wait_for_pending(struct pci_dev *dev, int pos, u16 mask)
848{
849 int i;
850
851 /* Wait for Transaction Pending bit clean */
852 for (i = 0; i < 4; i++) {
853 u16 status;
854 if (i)
855 msleep((1 << (i - 1)) * 100);
856
857 pci_read_config_word(dev, pos, &status);
858 if (!(status & mask))
859 return 1;
860 }
861
862 return 0;
863}
864
865static int pci_acs_enable;
866
867/**
868 * pci_request_acs - ask for ACS to be enabled if supported
869 */
870void pci_request_acs(void)
871{
872 pci_acs_enable = 1;
873}
874
875static const char *disable_acs_redir_param;
876
877/**
878 * pci_disable_acs_redir - disable ACS redirect capabilities
879 * @dev: the PCI device
880 *
881 * For only devices specified in the disable_acs_redir parameter.
882 */
883static void pci_disable_acs_redir(struct pci_dev *dev)
884{
885 int ret = 0;
886 const char *p;
887 int pos;
888 u16 ctrl;
889
890 if (!disable_acs_redir_param)
891 return;
892
893 p = disable_acs_redir_param;
894 while (*p) {
895 ret = pci_dev_str_match(dev, p, &p);
896 if (ret < 0) {
897 pr_info_once("PCI: Can't parse disable_acs_redir parameter: %s\n",
898 disable_acs_redir_param);
899
900 break;
901 } else if (ret == 1) {
902 /* Found a match */
903 break;
904 }
905
906 if (*p != ';' && *p != ',') {
907 /* End of param or invalid format */
908 break;
909 }
910 p++;
911 }
912
913 if (ret != 1)
914 return;
915
916 if (!pci_dev_specific_disable_acs_redir(dev))
917 return;
918
919 pos = dev->acs_cap;
920 if (!pos) {
921 pci_warn(dev, "cannot disable ACS redirect for this hardware as it does not have ACS capabilities\n");
922 return;
923 }
924
925 pci_read_config_word(dev, pos + PCI_ACS_CTRL, &ctrl);
926
927 /* P2P Request & Completion Redirect */
928 ctrl &= ~(PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_EC);
929
930 pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl);
931
932 pci_info(dev, "disabled ACS redirect\n");
933}
934
935/**
936 * pci_std_enable_acs - enable ACS on devices using standard ACS capabilities
937 * @dev: the PCI device
938 */
939static void pci_std_enable_acs(struct pci_dev *dev)
940{
941 int pos;
942 u16 cap;
943 u16 ctrl;
944
945 pos = dev->acs_cap;
946 if (!pos)
947 return;
948
949 pci_read_config_word(dev, pos + PCI_ACS_CAP, &cap);
950 pci_read_config_word(dev, pos + PCI_ACS_CTRL, &ctrl);
951
952 /* Source Validation */
953 ctrl |= (cap & PCI_ACS_SV);
954
955 /* P2P Request Redirect */
956 ctrl |= (cap & PCI_ACS_RR);
957
958 /* P2P Completion Redirect */
959 ctrl |= (cap & PCI_ACS_CR);
960
961 /* Upstream Forwarding */
962 ctrl |= (cap & PCI_ACS_UF);
963
964 /* Enable Translation Blocking for external devices and noats */
965 if (pci_ats_disabled() || dev->external_facing || dev->untrusted)
966 ctrl |= (cap & PCI_ACS_TB);
967
968 pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl);
969}
970
971/**
972 * pci_enable_acs - enable ACS if hardware support it
973 * @dev: the PCI device
974 */
975static void pci_enable_acs(struct pci_dev *dev)
976{
977 if (!pci_acs_enable)
978 goto disable_acs_redir;
979
980 if (!pci_dev_specific_enable_acs(dev))
981 goto disable_acs_redir;
982
983 pci_std_enable_acs(dev);
984
985disable_acs_redir:
986 /*
987 * Note: pci_disable_acs_redir() must be called even if ACS was not
988 * enabled by the kernel because it may have been enabled by
989 * platform firmware. So if we are told to disable it, we should
990 * always disable it after setting the kernel's default
991 * preferences.
992 */
993 pci_disable_acs_redir(dev);
994}
995
996/**
997 * pci_restore_bars - restore a device's BAR values (e.g. after wake-up)
998 * @dev: PCI device to have its BARs restored
999 *
1000 * Restore the BAR values for a given device, so as to make it
1001 * accessible by its driver.
1002 */
1003static void pci_restore_bars(struct pci_dev *dev)
1004{
1005 int i;
1006
1007 for (i = 0; i < PCI_BRIDGE_RESOURCES; i++)
1008 pci_update_resource(dev, i);
1009}
1010
1011static inline bool platform_pci_power_manageable(struct pci_dev *dev)
1012{
1013 if (pci_use_mid_pm())
1014 return true;
1015
1016 return acpi_pci_power_manageable(dev);
1017}
1018
1019static inline int platform_pci_set_power_state(struct pci_dev *dev,
1020 pci_power_t t)
1021{
1022 if (pci_use_mid_pm())
1023 return mid_pci_set_power_state(dev, t);
1024
1025 return acpi_pci_set_power_state(dev, t);
1026}
1027
1028static inline pci_power_t platform_pci_get_power_state(struct pci_dev *dev)
1029{
1030 if (pci_use_mid_pm())
1031 return mid_pci_get_power_state(dev);
1032
1033 return acpi_pci_get_power_state(dev);
1034}
1035
1036static inline void platform_pci_refresh_power_state(struct pci_dev *dev)
1037{
1038 if (!pci_use_mid_pm())
1039 acpi_pci_refresh_power_state(dev);
1040}
1041
1042static inline pci_power_t platform_pci_choose_state(struct pci_dev *dev)
1043{
1044 if (pci_use_mid_pm())
1045 return PCI_POWER_ERROR;
1046
1047 return acpi_pci_choose_state(dev);
1048}
1049
1050static inline int platform_pci_set_wakeup(struct pci_dev *dev, bool enable)
1051{
1052 if (pci_use_mid_pm())
1053 return PCI_POWER_ERROR;
1054
1055 return acpi_pci_wakeup(dev, enable);
1056}
1057
1058static inline bool platform_pci_need_resume(struct pci_dev *dev)
1059{
1060 if (pci_use_mid_pm())
1061 return false;
1062
1063 return acpi_pci_need_resume(dev);
1064}
1065
1066static inline bool platform_pci_bridge_d3(struct pci_dev *dev)
1067{
1068 if (pci_use_mid_pm())
1069 return false;
1070
1071 return acpi_pci_bridge_d3(dev);
1072}
1073
1074/**
1075 * pci_update_current_state - Read power state of given device and cache it
1076 * @dev: PCI device to handle.
1077 * @state: State to cache in case the device doesn't have the PM capability
1078 *
1079 * The power state is read from the PMCSR register, which however is
1080 * inaccessible in D3cold. The platform firmware is therefore queried first
1081 * to detect accessibility of the register. In case the platform firmware
1082 * reports an incorrect state or the device isn't power manageable by the
1083 * platform at all, we try to detect D3cold by testing accessibility of the
1084 * vendor ID in config space.
1085 */
1086void pci_update_current_state(struct pci_dev *dev, pci_power_t state)
1087{
1088 if (platform_pci_get_power_state(dev) == PCI_D3cold) {
1089 dev->current_state = PCI_D3cold;
1090 } else if (dev->pm_cap) {
1091 u16 pmcsr;
1092
1093 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
1094 if (PCI_POSSIBLE_ERROR(pmcsr)) {
1095 dev->current_state = PCI_D3cold;
1096 return;
1097 }
1098 dev->current_state = pmcsr & PCI_PM_CTRL_STATE_MASK;
1099 } else {
1100 dev->current_state = state;
1101 }
1102}
1103
1104/**
1105 * pci_refresh_power_state - Refresh the given device's power state data
1106 * @dev: Target PCI device.
1107 *
1108 * Ask the platform to refresh the devices power state information and invoke
1109 * pci_update_current_state() to update its current PCI power state.
1110 */
1111void pci_refresh_power_state(struct pci_dev *dev)
1112{
1113 platform_pci_refresh_power_state(dev);
1114 pci_update_current_state(dev, dev->current_state);
1115}
1116
1117/**
1118 * pci_platform_power_transition - Use platform to change device power state
1119 * @dev: PCI device to handle.
1120 * @state: State to put the device into.
1121 */
1122int pci_platform_power_transition(struct pci_dev *dev, pci_power_t state)
1123{
1124 int error;
1125
1126 error = platform_pci_set_power_state(dev, state);
1127 if (!error)
1128 pci_update_current_state(dev, state);
1129 else if (!dev->pm_cap) /* Fall back to PCI_D0 */
1130 dev->current_state = PCI_D0;
1131
1132 return error;
1133}
1134EXPORT_SYMBOL_GPL(pci_platform_power_transition);
1135
1136static int pci_resume_one(struct pci_dev *pci_dev, void *ign)
1137{
1138 pm_request_resume(&pci_dev->dev);
1139 return 0;
1140}
1141
1142/**
1143 * pci_resume_bus - Walk given bus and runtime resume devices on it
1144 * @bus: Top bus of the subtree to walk.
1145 */
1146void pci_resume_bus(struct pci_bus *bus)
1147{
1148 if (bus)
1149 pci_walk_bus(bus, pci_resume_one, NULL);
1150}
1151
1152static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout)
1153{
1154 int delay = 1;
1155 u32 id;
1156
1157 /*
1158 * After reset, the device should not silently discard config
1159 * requests, but it may still indicate that it needs more time by
1160 * responding to them with CRS completions. The Root Port will
1161 * generally synthesize ~0 (PCI_ERROR_RESPONSE) data to complete
1162 * the read (except when CRS SV is enabled and the read was for the
1163 * Vendor ID; in that case it synthesizes 0x0001 data).
1164 *
1165 * Wait for the device to return a non-CRS completion. Read the
1166 * Command register instead of Vendor ID so we don't have to
1167 * contend with the CRS SV value.
1168 */
1169 pci_read_config_dword(dev, PCI_COMMAND, &id);
1170 while (PCI_POSSIBLE_ERROR(id)) {
1171 if (delay > timeout) {
1172 pci_warn(dev, "not ready %dms after %s; giving up\n",
1173 delay - 1, reset_type);
1174 return -ENOTTY;
1175 }
1176
1177 if (delay > 1000)
1178 pci_info(dev, "not ready %dms after %s; waiting\n",
1179 delay - 1, reset_type);
1180
1181 msleep(delay);
1182 delay *= 2;
1183 pci_read_config_dword(dev, PCI_COMMAND, &id);
1184 }
1185
1186 if (delay > 1000)
1187 pci_info(dev, "ready %dms after %s\n", delay - 1,
1188 reset_type);
1189
1190 return 0;
1191}
1192
1193/**
1194 * pci_power_up - Put the given device into D0
1195 * @dev: PCI device to power up
1196 *
1197 * On success, return 0 or 1, depending on whether or not it is necessary to
1198 * restore the device's BARs subsequently (1 is returned in that case).
1199 */
1200int pci_power_up(struct pci_dev *dev)
1201{
1202 bool need_restore;
1203 pci_power_t state;
1204 u16 pmcsr;
1205
1206 platform_pci_set_power_state(dev, PCI_D0);
1207
1208 if (!dev->pm_cap) {
1209 state = platform_pci_get_power_state(dev);
1210 if (state == PCI_UNKNOWN)
1211 dev->current_state = PCI_D0;
1212 else
1213 dev->current_state = state;
1214
1215 if (state == PCI_D0)
1216 return 0;
1217
1218 return -EIO;
1219 }
1220
1221 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
1222 if (PCI_POSSIBLE_ERROR(pmcsr)) {
1223 pci_err(dev, "Unable to change power state from %s to D0, device inaccessible\n",
1224 pci_power_name(dev->current_state));
1225 dev->current_state = PCI_D3cold;
1226 return -EIO;
1227 }
1228
1229 state = pmcsr & PCI_PM_CTRL_STATE_MASK;
1230
1231 need_restore = (state == PCI_D3hot || dev->current_state >= PCI_D3hot) &&
1232 !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET);
1233
1234 if (state == PCI_D0)
1235 goto end;
1236
1237 /*
1238 * Force the entire word to 0. This doesn't affect PME_Status, disables
1239 * PME_En, and sets PowerState to 0.
1240 */
1241 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, 0);
1242
1243 /* Mandatory transition delays; see PCI PM 1.2. */
1244 if (state == PCI_D3hot)
1245 pci_dev_d3_sleep(dev);
1246 else if (state == PCI_D2)
1247 udelay(PCI_PM_D2_DELAY);
1248
1249end:
1250 dev->current_state = PCI_D0;
1251 if (need_restore)
1252 return 1;
1253
1254 return 0;
1255}
1256
1257/**
1258 * pci_set_full_power_state - Put a PCI device into D0 and update its state
1259 * @dev: PCI device to power up
1260 *
1261 * Call pci_power_up() to put @dev into D0, read from its PCI_PM_CTRL register
1262 * to confirm the state change, restore its BARs if they might be lost and
1263 * reconfigure ASPM in acordance with the new power state.
1264 *
1265 * If pci_restore_state() is going to be called right after a power state change
1266 * to D0, it is more efficient to use pci_power_up() directly instead of this
1267 * function.
1268 */
1269static int pci_set_full_power_state(struct pci_dev *dev)
1270{
1271 u16 pmcsr;
1272 int ret;
1273
1274 ret = pci_power_up(dev);
1275 if (ret < 0)
1276 return ret;
1277
1278 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
1279 dev->current_state = pmcsr & PCI_PM_CTRL_STATE_MASK;
1280 if (dev->current_state != PCI_D0) {
1281 pci_info_ratelimited(dev, "Refused to change power state from %s to D0\n",
1282 pci_power_name(dev->current_state));
1283 } else if (ret > 0) {
1284 /*
1285 * According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT
1286 * INTERFACE SPECIFICATION, REV. 1.2", a device transitioning
1287 * from D3hot to D0 _may_ perform an internal reset, thereby
1288 * going to "D0 Uninitialized" rather than "D0 Initialized".
1289 * For example, at least some versions of the 3c905B and the
1290 * 3c556B exhibit this behaviour.
1291 *
1292 * At least some laptop BIOSen (e.g. the Thinkpad T21) leave
1293 * devices in a D3hot state at boot. Consequently, we need to
1294 * restore at least the BARs so that the device will be
1295 * accessible to its driver.
1296 */
1297 pci_restore_bars(dev);
1298 }
1299
1300 return 0;
1301}
1302
1303/**
1304 * __pci_dev_set_current_state - Set current state of a PCI device
1305 * @dev: Device to handle
1306 * @data: pointer to state to be set
1307 */
1308static int __pci_dev_set_current_state(struct pci_dev *dev, void *data)
1309{
1310 pci_power_t state = *(pci_power_t *)data;
1311
1312 dev->current_state = state;
1313 return 0;
1314}
1315
1316/**
1317 * pci_bus_set_current_state - Walk given bus and set current state of devices
1318 * @bus: Top bus of the subtree to walk.
1319 * @state: state to be set
1320 */
1321void pci_bus_set_current_state(struct pci_bus *bus, pci_power_t state)
1322{
1323 if (bus)
1324 pci_walk_bus(bus, __pci_dev_set_current_state, &state);
1325}
1326
1327/**
1328 * pci_set_low_power_state - Put a PCI device into a low-power state.
1329 * @dev: PCI device to handle.
1330 * @state: PCI power state (D1, D2, D3hot) to put the device into.
1331 *
1332 * Use the device's PCI_PM_CTRL register to put it into a low-power state.
1333 *
1334 * RETURN VALUE:
1335 * -EINVAL if the requested state is invalid.
1336 * -EIO if device does not support PCI PM or its PM capabilities register has a
1337 * wrong version, or device doesn't support the requested state.
1338 * 0 if device already is in the requested state.
1339 * 0 if device's power state has been successfully changed.
1340 */
1341static int pci_set_low_power_state(struct pci_dev *dev, pci_power_t state)
1342{
1343 u16 pmcsr;
1344
1345 if (!dev->pm_cap)
1346 return -EIO;
1347
1348 /*
1349 * Validate transition: We can enter D0 from any state, but if
1350 * we're already in a low-power state, we can only go deeper. E.g.,
1351 * we can go from D1 to D3, but we can't go directly from D3 to D1;
1352 * we'd have to go from D3 to D0, then to D1.
1353 */
1354 if (dev->current_state <= PCI_D3cold && dev->current_state > state) {
1355 pci_dbg(dev, "Invalid power transition (from %s to %s)\n",
1356 pci_power_name(dev->current_state),
1357 pci_power_name(state));
1358 return -EINVAL;
1359 }
1360
1361 /* Check if this device supports the desired state */
1362 if ((state == PCI_D1 && !dev->d1_support)
1363 || (state == PCI_D2 && !dev->d2_support))
1364 return -EIO;
1365
1366 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
1367 if (PCI_POSSIBLE_ERROR(pmcsr)) {
1368 pci_err(dev, "Unable to change power state from %s to %s, device inaccessible\n",
1369 pci_power_name(dev->current_state),
1370 pci_power_name(state));
1371 dev->current_state = PCI_D3cold;
1372 return -EIO;
1373 }
1374
1375 pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
1376 pmcsr |= state;
1377
1378 /* Enter specified state */
1379 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
1380
1381 /* Mandatory power management transition delays; see PCI PM 1.2. */
1382 if (state == PCI_D3hot)
1383 pci_dev_d3_sleep(dev);
1384 else if (state == PCI_D2)
1385 udelay(PCI_PM_D2_DELAY);
1386
1387 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
1388 dev->current_state = pmcsr & PCI_PM_CTRL_STATE_MASK;
1389 if (dev->current_state != state)
1390 pci_info_ratelimited(dev, "Refused to change power state from %s to %s\n",
1391 pci_power_name(dev->current_state),
1392 pci_power_name(state));
1393
1394 return 0;
1395}
1396
1397/**
1398 * pci_set_power_state - Set the power state of a PCI device
1399 * @dev: PCI device to handle.
1400 * @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
1401 *
1402 * Transition a device to a new power state, using the platform firmware and/or
1403 * the device's PCI PM registers.
1404 *
1405 * RETURN VALUE:
1406 * -EINVAL if the requested state is invalid.
1407 * -EIO if device does not support PCI PM or its PM capabilities register has a
1408 * wrong version, or device doesn't support the requested state.
1409 * 0 if the transition is to D1 or D2 but D1 and D2 are not supported.
1410 * 0 if device already is in the requested state.
1411 * 0 if the transition is to D3 but D3 is not supported.
1412 * 0 if device's power state has been successfully changed.
1413 */
1414int pci_set_power_state(struct pci_dev *dev, pci_power_t state)
1415{
1416 int error;
1417
1418 /* Bound the state we're entering */
1419 if (state > PCI_D3cold)
1420 state = PCI_D3cold;
1421 else if (state < PCI_D0)
1422 state = PCI_D0;
1423 else if ((state == PCI_D1 || state == PCI_D2) && pci_no_d1d2(dev))
1424
1425 /*
1426 * If the device or the parent bridge do not support PCI
1427 * PM, ignore the request if we're doing anything other
1428 * than putting it into D0 (which would only happen on
1429 * boot).
1430 */
1431 return 0;
1432
1433 /* Check if we're already there */
1434 if (dev->current_state == state)
1435 return 0;
1436
1437 if (state == PCI_D0)
1438 return pci_set_full_power_state(dev);
1439
1440 /*
1441 * This device is quirked not to be put into D3, so don't put it in
1442 * D3
1443 */
1444 if (state >= PCI_D3hot && (dev->dev_flags & PCI_DEV_FLAGS_NO_D3))
1445 return 0;
1446
1447 if (state == PCI_D3cold) {
1448 /*
1449 * To put the device in D3cold, put it into D3hot in the native
1450 * way, then put it into D3cold using platform ops.
1451 */
1452 error = pci_set_low_power_state(dev, PCI_D3hot);
1453
1454 if (pci_platform_power_transition(dev, PCI_D3cold))
1455 return error;
1456
1457 /* Powering off a bridge may power off the whole hierarchy */
1458 if (dev->current_state == PCI_D3cold)
1459 pci_bus_set_current_state(dev->subordinate, PCI_D3cold);
1460 } else {
1461 error = pci_set_low_power_state(dev, state);
1462
1463 if (pci_platform_power_transition(dev, state))
1464 return error;
1465 }
1466
1467 return 0;
1468}
1469EXPORT_SYMBOL(pci_set_power_state);
1470
1471#define PCI_EXP_SAVE_REGS 7
1472
1473static struct pci_cap_saved_state *_pci_find_saved_cap(struct pci_dev *pci_dev,
1474 u16 cap, bool extended)
1475{
1476 struct pci_cap_saved_state *tmp;
1477
1478 hlist_for_each_entry(tmp, &pci_dev->saved_cap_space, next) {
1479 if (tmp->cap.cap_extended == extended && tmp->cap.cap_nr == cap)
1480 return tmp;
1481 }
1482 return NULL;
1483}
1484
1485struct pci_cap_saved_state *pci_find_saved_cap(struct pci_dev *dev, char cap)
1486{
1487 return _pci_find_saved_cap(dev, cap, false);
1488}
1489
1490struct pci_cap_saved_state *pci_find_saved_ext_cap(struct pci_dev *dev, u16 cap)
1491{
1492 return _pci_find_saved_cap(dev, cap, true);
1493}
1494
1495static int pci_save_pcie_state(struct pci_dev *dev)
1496{
1497 int i = 0;
1498 struct pci_cap_saved_state *save_state;
1499 u16 *cap;
1500
1501 if (!pci_is_pcie(dev))
1502 return 0;
1503
1504 save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
1505 if (!save_state) {
1506 pci_err(dev, "buffer not found in %s\n", __func__);
1507 return -ENOMEM;
1508 }
1509
1510 cap = (u16 *)&save_state->cap.data[0];
1511 pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &cap[i++]);
1512 pcie_capability_read_word(dev, PCI_EXP_LNKCTL, &cap[i++]);
1513 pcie_capability_read_word(dev, PCI_EXP_SLTCTL, &cap[i++]);
1514 pcie_capability_read_word(dev, PCI_EXP_RTCTL, &cap[i++]);
1515 pcie_capability_read_word(dev, PCI_EXP_DEVCTL2, &cap[i++]);
1516 pcie_capability_read_word(dev, PCI_EXP_LNKCTL2, &cap[i++]);
1517 pcie_capability_read_word(dev, PCI_EXP_SLTCTL2, &cap[i++]);
1518
1519 return 0;
1520}
1521
1522void pci_bridge_reconfigure_ltr(struct pci_dev *dev)
1523{
1524#ifdef CONFIG_PCIEASPM
1525 struct pci_dev *bridge;
1526 u32 ctl;
1527
1528 bridge = pci_upstream_bridge(dev);
1529 if (bridge && bridge->ltr_path) {
1530 pcie_capability_read_dword(bridge, PCI_EXP_DEVCTL2, &ctl);
1531 if (!(ctl & PCI_EXP_DEVCTL2_LTR_EN)) {
1532 pci_dbg(bridge, "re-enabling LTR\n");
1533 pcie_capability_set_word(bridge, PCI_EXP_DEVCTL2,
1534 PCI_EXP_DEVCTL2_LTR_EN);
1535 }
1536 }
1537#endif
1538}
1539
1540static void pci_restore_pcie_state(struct pci_dev *dev)
1541{
1542 int i = 0;
1543 struct pci_cap_saved_state *save_state;
1544 u16 *cap;
1545
1546 save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
1547 if (!save_state)
1548 return;
1549
1550 /*
1551 * Downstream ports reset the LTR enable bit when link goes down.
1552 * Check and re-configure the bit here before restoring device.
1553 * PCIe r5.0, sec 7.5.3.16.
1554 */
1555 pci_bridge_reconfigure_ltr(dev);
1556
1557 cap = (u16 *)&save_state->cap.data[0];
1558 pcie_capability_write_word(dev, PCI_EXP_DEVCTL, cap[i++]);
1559 pcie_capability_write_word(dev, PCI_EXP_LNKCTL, cap[i++]);
1560 pcie_capability_write_word(dev, PCI_EXP_SLTCTL, cap[i++]);
1561 pcie_capability_write_word(dev, PCI_EXP_RTCTL, cap[i++]);
1562 pcie_capability_write_word(dev, PCI_EXP_DEVCTL2, cap[i++]);
1563 pcie_capability_write_word(dev, PCI_EXP_LNKCTL2, cap[i++]);
1564 pcie_capability_write_word(dev, PCI_EXP_SLTCTL2, cap[i++]);
1565}
1566
1567static int pci_save_pcix_state(struct pci_dev *dev)
1568{
1569 int pos;
1570 struct pci_cap_saved_state *save_state;
1571
1572 pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
1573 if (!pos)
1574 return 0;
1575
1576 save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX);
1577 if (!save_state) {
1578 pci_err(dev, "buffer not found in %s\n", __func__);
1579 return -ENOMEM;
1580 }
1581
1582 pci_read_config_word(dev, pos + PCI_X_CMD,
1583 (u16 *)save_state->cap.data);
1584
1585 return 0;
1586}
1587
1588static void pci_restore_pcix_state(struct pci_dev *dev)
1589{
1590 int i = 0, pos;
1591 struct pci_cap_saved_state *save_state;
1592 u16 *cap;
1593
1594 save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX);
1595 pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
1596 if (!save_state || !pos)
1597 return;
1598 cap = (u16 *)&save_state->cap.data[0];
1599
1600 pci_write_config_word(dev, pos + PCI_X_CMD, cap[i++]);
1601}
1602
1603static void pci_save_ltr_state(struct pci_dev *dev)
1604{
1605 int ltr;
1606 struct pci_cap_saved_state *save_state;
1607 u32 *cap;
1608
1609 if (!pci_is_pcie(dev))
1610 return;
1611
1612 ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR);
1613 if (!ltr)
1614 return;
1615
1616 save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR);
1617 if (!save_state) {
1618 pci_err(dev, "no suspend buffer for LTR; ASPM issues possible after resume\n");
1619 return;
1620 }
1621
1622 /* Some broken devices only support dword access to LTR */
1623 cap = &save_state->cap.data[0];
1624 pci_read_config_dword(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, cap);
1625}
1626
1627static void pci_restore_ltr_state(struct pci_dev *dev)
1628{
1629 struct pci_cap_saved_state *save_state;
1630 int ltr;
1631 u32 *cap;
1632
1633 save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR);
1634 ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR);
1635 if (!save_state || !ltr)
1636 return;
1637
1638 /* Some broken devices only support dword access to LTR */
1639 cap = &save_state->cap.data[0];
1640 pci_write_config_dword(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, *cap);
1641}
1642
1643/**
1644 * pci_save_state - save the PCI configuration space of a device before
1645 * suspending
1646 * @dev: PCI device that we're dealing with
1647 */
1648int pci_save_state(struct pci_dev *dev)
1649{
1650 int i;
1651 /* XXX: 100% dword access ok here? */
1652 for (i = 0; i < 16; i++) {
1653 pci_read_config_dword(dev, i * 4, &dev->saved_config_space[i]);
1654 pci_dbg(dev, "saving config space at offset %#x (reading %#x)\n",
1655 i * 4, dev->saved_config_space[i]);
1656 }
1657 dev->state_saved = true;
1658
1659 i = pci_save_pcie_state(dev);
1660 if (i != 0)
1661 return i;
1662
1663 i = pci_save_pcix_state(dev);
1664 if (i != 0)
1665 return i;
1666
1667 pci_save_ltr_state(dev);
1668 pci_save_dpc_state(dev);
1669 pci_save_aer_state(dev);
1670 pci_save_ptm_state(dev);
1671 return pci_save_vc_state(dev);
1672}
1673EXPORT_SYMBOL(pci_save_state);
1674
1675static void pci_restore_config_dword(struct pci_dev *pdev, int offset,
1676 u32 saved_val, int retry, bool force)
1677{
1678 u32 val;
1679
1680 pci_read_config_dword(pdev, offset, &val);
1681 if (!force && val == saved_val)
1682 return;
1683
1684 for (;;) {
1685 pci_dbg(pdev, "restoring config space at offset %#x (was %#x, writing %#x)\n",
1686 offset, val, saved_val);
1687 pci_write_config_dword(pdev, offset, saved_val);
1688 if (retry-- <= 0)
1689 return;
1690
1691 pci_read_config_dword(pdev, offset, &val);
1692 if (val == saved_val)
1693 return;
1694
1695 mdelay(1);
1696 }
1697}
1698
1699static void pci_restore_config_space_range(struct pci_dev *pdev,
1700 int start, int end, int retry,
1701 bool force)
1702{
1703 int index;
1704
1705 for (index = end; index >= start; index--)
1706 pci_restore_config_dword(pdev, 4 * index,
1707 pdev->saved_config_space[index],
1708 retry, force);
1709}
1710
1711static void pci_restore_config_space(struct pci_dev *pdev)
1712{
1713 if (pdev->hdr_type == PCI_HEADER_TYPE_NORMAL) {
1714 pci_restore_config_space_range(pdev, 10, 15, 0, false);
1715 /* Restore BARs before the command register. */
1716 pci_restore_config_space_range(pdev, 4, 9, 10, false);
1717 pci_restore_config_space_range(pdev, 0, 3, 0, false);
1718 } else if (pdev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
1719 pci_restore_config_space_range(pdev, 12, 15, 0, false);
1720
1721 /*
1722 * Force rewriting of prefetch registers to avoid S3 resume
1723 * issues on Intel PCI bridges that occur when these
1724 * registers are not explicitly written.
1725 */
1726 pci_restore_config_space_range(pdev, 9, 11, 0, true);
1727 pci_restore_config_space_range(pdev, 0, 8, 0, false);
1728 } else {
1729 pci_restore_config_space_range(pdev, 0, 15, 0, false);
1730 }
1731}
1732
1733static void pci_restore_rebar_state(struct pci_dev *pdev)
1734{
1735 unsigned int pos, nbars, i;
1736 u32 ctrl;
1737
1738 pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR);
1739 if (!pos)
1740 return;
1741
1742 pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
1743 nbars = (ctrl & PCI_REBAR_CTRL_NBAR_MASK) >>
1744 PCI_REBAR_CTRL_NBAR_SHIFT;
1745
1746 for (i = 0; i < nbars; i++, pos += 8) {
1747 struct resource *res;
1748 int bar_idx, size;
1749
1750 pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
1751 bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX;
1752 res = pdev->resource + bar_idx;
1753 size = pci_rebar_bytes_to_size(resource_size(res));
1754 ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE;
1755 ctrl |= size << PCI_REBAR_CTRL_BAR_SHIFT;
1756 pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl);
1757 }
1758}
1759
1760/**
1761 * pci_restore_state - Restore the saved state of a PCI device
1762 * @dev: PCI device that we're dealing with
1763 */
1764void pci_restore_state(struct pci_dev *dev)
1765{
1766 if (!dev->state_saved)
1767 return;
1768
1769 /*
1770 * Restore max latencies (in the LTR capability) before enabling
1771 * LTR itself (in the PCIe capability).
1772 */
1773 pci_restore_ltr_state(dev);
1774
1775 pci_restore_pcie_state(dev);
1776 pci_restore_pasid_state(dev);
1777 pci_restore_pri_state(dev);
1778 pci_restore_ats_state(dev);
1779 pci_restore_vc_state(dev);
1780 pci_restore_rebar_state(dev);
1781 pci_restore_dpc_state(dev);
1782 pci_restore_ptm_state(dev);
1783
1784 pci_aer_clear_status(dev);
1785 pci_restore_aer_state(dev);
1786
1787 pci_restore_config_space(dev);
1788
1789 pci_restore_pcix_state(dev);
1790 pci_restore_msi_state(dev);
1791
1792 /* Restore ACS and IOV configuration state */
1793 pci_enable_acs(dev);
1794 pci_restore_iov_state(dev);
1795
1796 dev->state_saved = false;
1797}
1798EXPORT_SYMBOL(pci_restore_state);
1799
1800struct pci_saved_state {
1801 u32 config_space[16];
1802 struct pci_cap_saved_data cap[];
1803};
1804
1805/**
1806 * pci_store_saved_state - Allocate and return an opaque struct containing
1807 * the device saved state.
1808 * @dev: PCI device that we're dealing with
1809 *
1810 * Return NULL if no state or error.
1811 */
1812struct pci_saved_state *pci_store_saved_state(struct pci_dev *dev)
1813{
1814 struct pci_saved_state *state;
1815 struct pci_cap_saved_state *tmp;
1816 struct pci_cap_saved_data *cap;
1817 size_t size;
1818
1819 if (!dev->state_saved)
1820 return NULL;
1821
1822 size = sizeof(*state) + sizeof(struct pci_cap_saved_data);
1823
1824 hlist_for_each_entry(tmp, &dev->saved_cap_space, next)
1825 size += sizeof(struct pci_cap_saved_data) + tmp->cap.size;
1826
1827 state = kzalloc(size, GFP_KERNEL);
1828 if (!state)
1829 return NULL;
1830
1831 memcpy(state->config_space, dev->saved_config_space,
1832 sizeof(state->config_space));
1833
1834 cap = state->cap;
1835 hlist_for_each_entry(tmp, &dev->saved_cap_space, next) {
1836 size_t len = sizeof(struct pci_cap_saved_data) + tmp->cap.size;
1837 memcpy(cap, &tmp->cap, len);
1838 cap = (struct pci_cap_saved_data *)((u8 *)cap + len);
1839 }
1840 /* Empty cap_save terminates list */
1841
1842 return state;
1843}
1844EXPORT_SYMBOL_GPL(pci_store_saved_state);
1845
1846/**
1847 * pci_load_saved_state - Reload the provided save state into struct pci_dev.
1848 * @dev: PCI device that we're dealing with
1849 * @state: Saved state returned from pci_store_saved_state()
1850 */
1851int pci_load_saved_state(struct pci_dev *dev,
1852 struct pci_saved_state *state)
1853{
1854 struct pci_cap_saved_data *cap;
1855
1856 dev->state_saved = false;
1857
1858 if (!state)
1859 return 0;
1860
1861 memcpy(dev->saved_config_space, state->config_space,
1862 sizeof(state->config_space));
1863
1864 cap = state->cap;
1865 while (cap->size) {
1866 struct pci_cap_saved_state *tmp;
1867
1868 tmp = _pci_find_saved_cap(dev, cap->cap_nr, cap->cap_extended);
1869 if (!tmp || tmp->cap.size != cap->size)
1870 return -EINVAL;
1871
1872 memcpy(tmp->cap.data, cap->data, tmp->cap.size);
1873 cap = (struct pci_cap_saved_data *)((u8 *)cap +
1874 sizeof(struct pci_cap_saved_data) + cap->size);
1875 }
1876
1877 dev->state_saved = true;
1878 return 0;
1879}
1880EXPORT_SYMBOL_GPL(pci_load_saved_state);
1881
1882/**
1883 * pci_load_and_free_saved_state - Reload the save state pointed to by state,
1884 * and free the memory allocated for it.
1885 * @dev: PCI device that we're dealing with
1886 * @state: Pointer to saved state returned from pci_store_saved_state()
1887 */
1888int pci_load_and_free_saved_state(struct pci_dev *dev,
1889 struct pci_saved_state **state)
1890{
1891 int ret = pci_load_saved_state(dev, *state);
1892 kfree(*state);
1893 *state = NULL;
1894 return ret;
1895}
1896EXPORT_SYMBOL_GPL(pci_load_and_free_saved_state);
1897
1898int __weak pcibios_enable_device(struct pci_dev *dev, int bars)
1899{
1900 return pci_enable_resources(dev, bars);
1901}
1902
1903static int do_pci_enable_device(struct pci_dev *dev, int bars)
1904{
1905 int err;
1906 struct pci_dev *bridge;
1907 u16 cmd;
1908 u8 pin;
1909
1910 err = pci_set_power_state(dev, PCI_D0);
1911 if (err < 0 && err != -EIO)
1912 return err;
1913
1914 bridge = pci_upstream_bridge(dev);
1915 if (bridge)
1916 pcie_aspm_powersave_config_link(bridge);
1917
1918 err = pcibios_enable_device(dev, bars);
1919 if (err < 0)
1920 return err;
1921 pci_fixup_device(pci_fixup_enable, dev);
1922
1923 if (dev->msi_enabled || dev->msix_enabled)
1924 return 0;
1925
1926 pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
1927 if (pin) {
1928 pci_read_config_word(dev, PCI_COMMAND, &cmd);
1929 if (cmd & PCI_COMMAND_INTX_DISABLE)
1930 pci_write_config_word(dev, PCI_COMMAND,
1931 cmd & ~PCI_COMMAND_INTX_DISABLE);
1932 }
1933
1934 return 0;
1935}
1936
1937/**
1938 * pci_reenable_device - Resume abandoned device
1939 * @dev: PCI device to be resumed
1940 *
1941 * NOTE: This function is a backend of pci_default_resume() and is not supposed
1942 * to be called by normal code, write proper resume handler and use it instead.
1943 */
1944int pci_reenable_device(struct pci_dev *dev)
1945{
1946 if (pci_is_enabled(dev))
1947 return do_pci_enable_device(dev, (1 << PCI_NUM_RESOURCES) - 1);
1948 return 0;
1949}
1950EXPORT_SYMBOL(pci_reenable_device);
1951
1952static void pci_enable_bridge(struct pci_dev *dev)
1953{
1954 struct pci_dev *bridge;
1955 int retval;
1956
1957 bridge = pci_upstream_bridge(dev);
1958 if (bridge)
1959 pci_enable_bridge(bridge);
1960
1961 if (pci_is_enabled(dev)) {
1962 if (!dev->is_busmaster)
1963 pci_set_master(dev);
1964 return;
1965 }
1966
1967 retval = pci_enable_device(dev);
1968 if (retval)
1969 pci_err(dev, "Error enabling bridge (%d), continuing\n",
1970 retval);
1971 pci_set_master(dev);
1972}
1973
1974static int pci_enable_device_flags(struct pci_dev *dev, unsigned long flags)
1975{
1976 struct pci_dev *bridge;
1977 int err;
1978 int i, bars = 0;
1979
1980 /*
1981 * Power state could be unknown at this point, either due to a fresh
1982 * boot or a device removal call. So get the current power state
1983 * so that things like MSI message writing will behave as expected
1984 * (e.g. if the device really is in D0 at enable time).
1985 */
1986 pci_update_current_state(dev, dev->current_state);
1987
1988 if (atomic_inc_return(&dev->enable_cnt) > 1)
1989 return 0; /* already enabled */
1990
1991 bridge = pci_upstream_bridge(dev);
1992 if (bridge)
1993 pci_enable_bridge(bridge);
1994
1995 /* only skip sriov related */
1996 for (i = 0; i <= PCI_ROM_RESOURCE; i++)
1997 if (dev->resource[i].flags & flags)
1998 bars |= (1 << i);
1999 for (i = PCI_BRIDGE_RESOURCES; i < DEVICE_COUNT_RESOURCE; i++)
2000 if (dev->resource[i].flags & flags)
2001 bars |= (1 << i);
2002
2003 err = do_pci_enable_device(dev, bars);
2004 if (err < 0)
2005 atomic_dec(&dev->enable_cnt);
2006 return err;
2007}
2008
2009/**
2010 * pci_enable_device_io - Initialize a device for use with IO space
2011 * @dev: PCI device to be initialized
2012 *
2013 * Initialize device before it's used by a driver. Ask low-level code
2014 * to enable I/O resources. Wake up the device if it was suspended.
2015 * Beware, this function can fail.
2016 */
2017int pci_enable_device_io(struct pci_dev *dev)
2018{
2019 return pci_enable_device_flags(dev, IORESOURCE_IO);
2020}
2021EXPORT_SYMBOL(pci_enable_device_io);
2022
2023/**
2024 * pci_enable_device_mem - Initialize a device for use with Memory space
2025 * @dev: PCI device to be initialized
2026 *
2027 * Initialize device before it's used by a driver. Ask low-level code
2028 * to enable Memory resources. Wake up the device if it was suspended.
2029 * Beware, this function can fail.
2030 */
2031int pci_enable_device_mem(struct pci_dev *dev)
2032{
2033 return pci_enable_device_flags(dev, IORESOURCE_MEM);
2034}
2035EXPORT_SYMBOL(pci_enable_device_mem);
2036
2037/**
2038 * pci_enable_device - Initialize device before it's used by a driver.
2039 * @dev: PCI device to be initialized
2040 *
2041 * Initialize device before it's used by a driver. Ask low-level code
2042 * to enable I/O and memory. Wake up the device if it was suspended.
2043 * Beware, this function can fail.
2044 *
2045 * Note we don't actually enable the device many times if we call
2046 * this function repeatedly (we just increment the count).
2047 */
2048int pci_enable_device(struct pci_dev *dev)
2049{
2050 return pci_enable_device_flags(dev, IORESOURCE_MEM | IORESOURCE_IO);
2051}
2052EXPORT_SYMBOL(pci_enable_device);
2053
2054/*
2055 * Managed PCI resources. This manages device on/off, INTx/MSI/MSI-X
2056 * on/off and BAR regions. pci_dev itself records MSI/MSI-X status, so
2057 * there's no need to track it separately. pci_devres is initialized
2058 * when a device is enabled using managed PCI device enable interface.
2059 */
2060struct pci_devres {
2061 unsigned int enabled:1;
2062 unsigned int pinned:1;
2063 unsigned int orig_intx:1;
2064 unsigned int restore_intx:1;
2065 unsigned int mwi:1;
2066 u32 region_mask;
2067};
2068
2069static void pcim_release(struct device *gendev, void *res)
2070{
2071 struct pci_dev *dev = to_pci_dev(gendev);
2072 struct pci_devres *this = res;
2073 int i;
2074
2075 for (i = 0; i < DEVICE_COUNT_RESOURCE; i++)
2076 if (this->region_mask & (1 << i))
2077 pci_release_region(dev, i);
2078
2079 if (this->mwi)
2080 pci_clear_mwi(dev);
2081
2082 if (this->restore_intx)
2083 pci_intx(dev, this->orig_intx);
2084
2085 if (this->enabled && !this->pinned)
2086 pci_disable_device(dev);
2087}
2088
2089static struct pci_devres *get_pci_dr(struct pci_dev *pdev)
2090{
2091 struct pci_devres *dr, *new_dr;
2092
2093 dr = devres_find(&pdev->dev, pcim_release, NULL, NULL);
2094 if (dr)
2095 return dr;
2096
2097 new_dr = devres_alloc(pcim_release, sizeof(*new_dr), GFP_KERNEL);
2098 if (!new_dr)
2099 return NULL;
2100 return devres_get(&pdev->dev, new_dr, NULL, NULL);
2101}
2102
2103static struct pci_devres *find_pci_dr(struct pci_dev *pdev)
2104{
2105 if (pci_is_managed(pdev))
2106 return devres_find(&pdev->dev, pcim_release, NULL, NULL);
2107 return NULL;
2108}
2109
2110/**
2111 * pcim_enable_device - Managed pci_enable_device()
2112 * @pdev: PCI device to be initialized
2113 *
2114 * Managed pci_enable_device().
2115 */
2116int pcim_enable_device(struct pci_dev *pdev)
2117{
2118 struct pci_devres *dr;
2119 int rc;
2120
2121 dr = get_pci_dr(pdev);
2122 if (unlikely(!dr))
2123 return -ENOMEM;
2124 if (dr->enabled)
2125 return 0;
2126
2127 rc = pci_enable_device(pdev);
2128 if (!rc) {
2129 pdev->is_managed = 1;
2130 dr->enabled = 1;
2131 }
2132 return rc;
2133}
2134EXPORT_SYMBOL(pcim_enable_device);
2135
2136/**
2137 * pcim_pin_device - Pin managed PCI device
2138 * @pdev: PCI device to pin
2139 *
2140 * Pin managed PCI device @pdev. Pinned device won't be disabled on
2141 * driver detach. @pdev must have been enabled with
2142 * pcim_enable_device().
2143 */
2144void pcim_pin_device(struct pci_dev *pdev)
2145{
2146 struct pci_devres *dr;
2147
2148 dr = find_pci_dr(pdev);
2149 WARN_ON(!dr || !dr->enabled);
2150 if (dr)
2151 dr->pinned = 1;
2152}
2153EXPORT_SYMBOL(pcim_pin_device);
2154
2155/*
2156 * pcibios_device_add - provide arch specific hooks when adding device dev
2157 * @dev: the PCI device being added
2158 *
2159 * Permits the platform to provide architecture specific functionality when
2160 * devices are added. This is the default implementation. Architecture
2161 * implementations can override this.
2162 */
2163int __weak pcibios_device_add(struct pci_dev *dev)
2164{
2165 return 0;
2166}
2167
2168/**
2169 * pcibios_release_device - provide arch specific hooks when releasing
2170 * device dev
2171 * @dev: the PCI device being released
2172 *
2173 * Permits the platform to provide architecture specific functionality when
2174 * devices are released. This is the default implementation. Architecture
2175 * implementations can override this.
2176 */
2177void __weak pcibios_release_device(struct pci_dev *dev) {}
2178
2179/**
2180 * pcibios_disable_device - disable arch specific PCI resources for device dev
2181 * @dev: the PCI device to disable
2182 *
2183 * Disables architecture specific PCI resources for the device. This
2184 * is the default implementation. Architecture implementations can
2185 * override this.
2186 */
2187void __weak pcibios_disable_device(struct pci_dev *dev) {}
2188
2189/**
2190 * pcibios_penalize_isa_irq - penalize an ISA IRQ
2191 * @irq: ISA IRQ to penalize
2192 * @active: IRQ active or not
2193 *
2194 * Permits the platform to provide architecture-specific functionality when
2195 * penalizing ISA IRQs. This is the default implementation. Architecture
2196 * implementations can override this.
2197 */
2198void __weak pcibios_penalize_isa_irq(int irq, int active) {}
2199
2200static void do_pci_disable_device(struct pci_dev *dev)
2201{
2202 u16 pci_command;
2203
2204 pci_read_config_word(dev, PCI_COMMAND, &pci_command);
2205 if (pci_command & PCI_COMMAND_MASTER) {
2206 pci_command &= ~PCI_COMMAND_MASTER;
2207 pci_write_config_word(dev, PCI_COMMAND, pci_command);
2208 }
2209
2210 pcibios_disable_device(dev);
2211}
2212
2213/**
2214 * pci_disable_enabled_device - Disable device without updating enable_cnt
2215 * @dev: PCI device to disable
2216 *
2217 * NOTE: This function is a backend of PCI power management routines and is
2218 * not supposed to be called drivers.
2219 */
2220void pci_disable_enabled_device(struct pci_dev *dev)
2221{
2222 if (pci_is_enabled(dev))
2223 do_pci_disable_device(dev);
2224}
2225
2226/**
2227 * pci_disable_device - Disable PCI device after use
2228 * @dev: PCI device to be disabled
2229 *
2230 * Signal to the system that the PCI device is not in use by the system
2231 * anymore. This only involves disabling PCI bus-mastering, if active.
2232 *
2233 * Note we don't actually disable the device until all callers of
2234 * pci_enable_device() have called pci_disable_device().
2235 */
2236void pci_disable_device(struct pci_dev *dev)
2237{
2238 struct pci_devres *dr;
2239
2240 dr = find_pci_dr(dev);
2241 if (dr)
2242 dr->enabled = 0;
2243
2244 dev_WARN_ONCE(&dev->dev, atomic_read(&dev->enable_cnt) <= 0,
2245 "disabling already-disabled device");
2246
2247 if (atomic_dec_return(&dev->enable_cnt) != 0)
2248 return;
2249
2250 do_pci_disable_device(dev);
2251
2252 dev->is_busmaster = 0;
2253}
2254EXPORT_SYMBOL(pci_disable_device);
2255
2256/**
2257 * pcibios_set_pcie_reset_state - set reset state for device dev
2258 * @dev: the PCIe device reset
2259 * @state: Reset state to enter into
2260 *
2261 * Set the PCIe reset state for the device. This is the default
2262 * implementation. Architecture implementations can override this.
2263 */
2264int __weak pcibios_set_pcie_reset_state(struct pci_dev *dev,
2265 enum pcie_reset_state state)
2266{
2267 return -EINVAL;
2268}
2269
2270/**
2271 * pci_set_pcie_reset_state - set reset state for device dev
2272 * @dev: the PCIe device reset
2273 * @state: Reset state to enter into
2274 *
2275 * Sets the PCI reset state for the device.
2276 */
2277int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state)
2278{
2279 return pcibios_set_pcie_reset_state(dev, state);
2280}
2281EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state);
2282
2283#ifdef CONFIG_PCIEAER
2284void pcie_clear_device_status(struct pci_dev *dev)
2285{
2286 u16 sta;
2287
2288 pcie_capability_read_word(dev, PCI_EXP_DEVSTA, &sta);
2289 pcie_capability_write_word(dev, PCI_EXP_DEVSTA, sta);
2290}
2291#endif
2292
2293/**
2294 * pcie_clear_root_pme_status - Clear root port PME interrupt status.
2295 * @dev: PCIe root port or event collector.
2296 */
2297void pcie_clear_root_pme_status(struct pci_dev *dev)
2298{
2299 pcie_capability_set_dword(dev, PCI_EXP_RTSTA, PCI_EXP_RTSTA_PME);
2300}
2301
2302/**
2303 * pci_check_pme_status - Check if given device has generated PME.
2304 * @dev: Device to check.
2305 *
2306 * Check the PME status of the device and if set, clear it and clear PME enable
2307 * (if set). Return 'true' if PME status and PME enable were both set or
2308 * 'false' otherwise.
2309 */
2310bool pci_check_pme_status(struct pci_dev *dev)
2311{
2312 int pmcsr_pos;
2313 u16 pmcsr;
2314 bool ret = false;
2315
2316 if (!dev->pm_cap)
2317 return false;
2318
2319 pmcsr_pos = dev->pm_cap + PCI_PM_CTRL;
2320 pci_read_config_word(dev, pmcsr_pos, &pmcsr);
2321 if (!(pmcsr & PCI_PM_CTRL_PME_STATUS))
2322 return false;
2323
2324 /* Clear PME status. */
2325 pmcsr |= PCI_PM_CTRL_PME_STATUS;
2326 if (pmcsr & PCI_PM_CTRL_PME_ENABLE) {
2327 /* Disable PME to avoid interrupt flood. */
2328 pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
2329 ret = true;
2330 }
2331
2332 pci_write_config_word(dev, pmcsr_pos, pmcsr);
2333
2334 return ret;
2335}
2336
2337/**
2338 * pci_pme_wakeup - Wake up a PCI device if its PME Status bit is set.
2339 * @dev: Device to handle.
2340 * @pme_poll_reset: Whether or not to reset the device's pme_poll flag.
2341 *
2342 * Check if @dev has generated PME and queue a resume request for it in that
2343 * case.
2344 */
2345static int pci_pme_wakeup(struct pci_dev *dev, void *pme_poll_reset)
2346{
2347 if (pme_poll_reset && dev->pme_poll)
2348 dev->pme_poll = false;
2349
2350 if (pci_check_pme_status(dev)) {
2351 pci_wakeup_event(dev);
2352 pm_request_resume(&dev->dev);
2353 }
2354 return 0;
2355}
2356
2357/**
2358 * pci_pme_wakeup_bus - Walk given bus and wake up devices on it, if necessary.
2359 * @bus: Top bus of the subtree to walk.
2360 */
2361void pci_pme_wakeup_bus(struct pci_bus *bus)
2362{
2363 if (bus)
2364 pci_walk_bus(bus, pci_pme_wakeup, (void *)true);
2365}
2366
2367
2368/**
2369 * pci_pme_capable - check the capability of PCI device to generate PME#
2370 * @dev: PCI device to handle.
2371 * @state: PCI state from which device will issue PME#.
2372 */
2373bool pci_pme_capable(struct pci_dev *dev, pci_power_t state)
2374{
2375 if (!dev->pm_cap)
2376 return false;
2377
2378 return !!(dev->pme_support & (1 << state));
2379}
2380EXPORT_SYMBOL(pci_pme_capable);
2381
2382static void pci_pme_list_scan(struct work_struct *work)
2383{
2384 struct pci_pme_device *pme_dev, *n;
2385
2386 mutex_lock(&pci_pme_list_mutex);
2387 list_for_each_entry_safe(pme_dev, n, &pci_pme_list, list) {
2388 if (pme_dev->dev->pme_poll) {
2389 struct pci_dev *bridge;
2390
2391 bridge = pme_dev->dev->bus->self;
2392 /*
2393 * If bridge is in low power state, the
2394 * configuration space of subordinate devices
2395 * may be not accessible
2396 */
2397 if (bridge && bridge->current_state != PCI_D0)
2398 continue;
2399 /*
2400 * If the device is in D3cold it should not be
2401 * polled either.
2402 */
2403 if (pme_dev->dev->current_state == PCI_D3cold)
2404 continue;
2405
2406 pci_pme_wakeup(pme_dev->dev, NULL);
2407 } else {
2408 list_del(&pme_dev->list);
2409 kfree(pme_dev);
2410 }
2411 }
2412 if (!list_empty(&pci_pme_list))
2413 queue_delayed_work(system_freezable_wq, &pci_pme_work,
2414 msecs_to_jiffies(PME_TIMEOUT));
2415 mutex_unlock(&pci_pme_list_mutex);
2416}
2417
2418static void __pci_pme_active(struct pci_dev *dev, bool enable)
2419{
2420 u16 pmcsr;
2421
2422 if (!dev->pme_support)
2423 return;
2424
2425 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
2426 /* Clear PME_Status by writing 1 to it and enable PME# */
2427 pmcsr |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE;
2428 if (!enable)
2429 pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
2430
2431 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
2432}
2433
2434/**
2435 * pci_pme_restore - Restore PME configuration after config space restore.
2436 * @dev: PCI device to update.
2437 */
2438void pci_pme_restore(struct pci_dev *dev)
2439{
2440 u16 pmcsr;
2441
2442 if (!dev->pme_support)
2443 return;
2444
2445 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
2446 if (dev->wakeup_prepared) {
2447 pmcsr |= PCI_PM_CTRL_PME_ENABLE;
2448 pmcsr &= ~PCI_PM_CTRL_PME_STATUS;
2449 } else {
2450 pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
2451 pmcsr |= PCI_PM_CTRL_PME_STATUS;
2452 }
2453 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
2454}
2455
2456/**
2457 * pci_pme_active - enable or disable PCI device's PME# function
2458 * @dev: PCI device to handle.
2459 * @enable: 'true' to enable PME# generation; 'false' to disable it.
2460 *
2461 * The caller must verify that the device is capable of generating PME# before
2462 * calling this function with @enable equal to 'true'.
2463 */
2464void pci_pme_active(struct pci_dev *dev, bool enable)
2465{
2466 __pci_pme_active(dev, enable);
2467
2468 /*
2469 * PCI (as opposed to PCIe) PME requires that the device have
2470 * its PME# line hooked up correctly. Not all hardware vendors
2471 * do this, so the PME never gets delivered and the device
2472 * remains asleep. The easiest way around this is to
2473 * periodically walk the list of suspended devices and check
2474 * whether any have their PME flag set. The assumption is that
2475 * we'll wake up often enough anyway that this won't be a huge
2476 * hit, and the power savings from the devices will still be a
2477 * win.
2478 *
2479 * Although PCIe uses in-band PME message instead of PME# line
2480 * to report PME, PME does not work for some PCIe devices in
2481 * reality. For example, there are devices that set their PME
2482 * status bits, but don't really bother to send a PME message;
2483 * there are PCI Express Root Ports that don't bother to
2484 * trigger interrupts when they receive PME messages from the
2485 * devices below. So PME poll is used for PCIe devices too.
2486 */
2487
2488 if (dev->pme_poll) {
2489 struct pci_pme_device *pme_dev;
2490 if (enable) {
2491 pme_dev = kmalloc(sizeof(struct pci_pme_device),
2492 GFP_KERNEL);
2493 if (!pme_dev) {
2494 pci_warn(dev, "can't enable PME#\n");
2495 return;
2496 }
2497 pme_dev->dev = dev;
2498 mutex_lock(&pci_pme_list_mutex);
2499 list_add(&pme_dev->list, &pci_pme_list);
2500 if (list_is_singular(&pci_pme_list))
2501 queue_delayed_work(system_freezable_wq,
2502 &pci_pme_work,
2503 msecs_to_jiffies(PME_TIMEOUT));
2504 mutex_unlock(&pci_pme_list_mutex);
2505 } else {
2506 mutex_lock(&pci_pme_list_mutex);
2507 list_for_each_entry(pme_dev, &pci_pme_list, list) {
2508 if (pme_dev->dev == dev) {
2509 list_del(&pme_dev->list);
2510 kfree(pme_dev);
2511 break;
2512 }
2513 }
2514 mutex_unlock(&pci_pme_list_mutex);
2515 }
2516 }
2517
2518 pci_dbg(dev, "PME# %s\n", enable ? "enabled" : "disabled");
2519}
2520EXPORT_SYMBOL(pci_pme_active);
2521
2522/**
2523 * __pci_enable_wake - enable PCI device as wakeup event source
2524 * @dev: PCI device affected
2525 * @state: PCI state from which device will issue wakeup events
2526 * @enable: True to enable event generation; false to disable
2527 *
2528 * This enables the device as a wakeup event source, or disables it.
2529 * When such events involves platform-specific hooks, those hooks are
2530 * called automatically by this routine.
2531 *
2532 * Devices with legacy power management (no standard PCI PM capabilities)
2533 * always require such platform hooks.
2534 *
2535 * RETURN VALUE:
2536 * 0 is returned on success
2537 * -EINVAL is returned if device is not supposed to wake up the system
2538 * Error code depending on the platform is returned if both the platform and
2539 * the native mechanism fail to enable the generation of wake-up events
2540 */
2541static int __pci_enable_wake(struct pci_dev *dev, pci_power_t state, bool enable)
2542{
2543 int ret = 0;
2544
2545 /*
2546 * Bridges that are not power-manageable directly only signal
2547 * wakeup on behalf of subordinate devices which is set up
2548 * elsewhere, so skip them. However, bridges that are
2549 * power-manageable may signal wakeup for themselves (for example,
2550 * on a hotplug event) and they need to be covered here.
2551 */
2552 if (!pci_power_manageable(dev))
2553 return 0;
2554
2555 /* Don't do the same thing twice in a row for one device. */
2556 if (!!enable == !!dev->wakeup_prepared)
2557 return 0;
2558
2559 /*
2560 * According to "PCI System Architecture" 4th ed. by Tom Shanley & Don
2561 * Anderson we should be doing PME# wake enable followed by ACPI wake
2562 * enable. To disable wake-up we call the platform first, for symmetry.
2563 */
2564
2565 if (enable) {
2566 int error;
2567
2568 /*
2569 * Enable PME signaling if the device can signal PME from
2570 * D3cold regardless of whether or not it can signal PME from
2571 * the current target state, because that will allow it to
2572 * signal PME when the hierarchy above it goes into D3cold and
2573 * the device itself ends up in D3cold as a result of that.
2574 */
2575 if (pci_pme_capable(dev, state) || pci_pme_capable(dev, PCI_D3cold))
2576 pci_pme_active(dev, true);
2577 else
2578 ret = 1;
2579 error = platform_pci_set_wakeup(dev, true);
2580 if (ret)
2581 ret = error;
2582 if (!ret)
2583 dev->wakeup_prepared = true;
2584 } else {
2585 platform_pci_set_wakeup(dev, false);
2586 pci_pme_active(dev, false);
2587 dev->wakeup_prepared = false;
2588 }
2589
2590 return ret;
2591}
2592
2593/**
2594 * pci_enable_wake - change wakeup settings for a PCI device
2595 * @pci_dev: Target device
2596 * @state: PCI state from which device will issue wakeup events
2597 * @enable: Whether or not to enable event generation
2598 *
2599 * If @enable is set, check device_may_wakeup() for the device before calling
2600 * __pci_enable_wake() for it.
2601 */
2602int pci_enable_wake(struct pci_dev *pci_dev, pci_power_t state, bool enable)
2603{
2604 if (enable && !device_may_wakeup(&pci_dev->dev))
2605 return -EINVAL;
2606
2607 return __pci_enable_wake(pci_dev, state, enable);
2608}
2609EXPORT_SYMBOL(pci_enable_wake);
2610
2611/**
2612 * pci_wake_from_d3 - enable/disable device to wake up from D3_hot or D3_cold
2613 * @dev: PCI device to prepare
2614 * @enable: True to enable wake-up event generation; false to disable
2615 *
2616 * Many drivers want the device to wake up the system from D3_hot or D3_cold
2617 * and this function allows them to set that up cleanly - pci_enable_wake()
2618 * should not be called twice in a row to enable wake-up due to PCI PM vs ACPI
2619 * ordering constraints.
2620 *
2621 * This function only returns error code if the device is not allowed to wake
2622 * up the system from sleep or it is not capable of generating PME# from both
2623 * D3_hot and D3_cold and the platform is unable to enable wake-up power for it.
2624 */
2625int pci_wake_from_d3(struct pci_dev *dev, bool enable)
2626{
2627 return pci_pme_capable(dev, PCI_D3cold) ?
2628 pci_enable_wake(dev, PCI_D3cold, enable) :
2629 pci_enable_wake(dev, PCI_D3hot, enable);
2630}
2631EXPORT_SYMBOL(pci_wake_from_d3);
2632
2633/**
2634 * pci_target_state - find an appropriate low power state for a given PCI dev
2635 * @dev: PCI device
2636 * @wakeup: Whether or not wakeup functionality will be enabled for the device.
2637 *
2638 * Use underlying platform code to find a supported low power state for @dev.
2639 * If the platform can't manage @dev, return the deepest state from which it
2640 * can generate wake events, based on any available PME info.
2641 */
2642static pci_power_t pci_target_state(struct pci_dev *dev, bool wakeup)
2643{
2644 if (platform_pci_power_manageable(dev)) {
2645 /*
2646 * Call the platform to find the target state for the device.
2647 */
2648 pci_power_t state = platform_pci_choose_state(dev);
2649
2650 switch (state) {
2651 case PCI_POWER_ERROR:
2652 case PCI_UNKNOWN:
2653 return PCI_D3hot;
2654
2655 case PCI_D1:
2656 case PCI_D2:
2657 if (pci_no_d1d2(dev))
2658 return PCI_D3hot;
2659 }
2660
2661 return state;
2662 }
2663
2664 /*
2665 * If the device is in D3cold even though it's not power-manageable by
2666 * the platform, it may have been powered down by non-standard means.
2667 * Best to let it slumber.
2668 */
2669 if (dev->current_state == PCI_D3cold)
2670 return PCI_D3cold;
2671 else if (!dev->pm_cap)
2672 return PCI_D0;
2673
2674 if (wakeup && dev->pme_support) {
2675 pci_power_t state = PCI_D3hot;
2676
2677 /*
2678 * Find the deepest state from which the device can generate
2679 * PME#.
2680 */
2681 while (state && !(dev->pme_support & (1 << state)))
2682 state--;
2683
2684 if (state)
2685 return state;
2686 else if (dev->pme_support & 1)
2687 return PCI_D0;
2688 }
2689
2690 return PCI_D3hot;
2691}
2692
2693/**
2694 * pci_prepare_to_sleep - prepare PCI device for system-wide transition
2695 * into a sleep state
2696 * @dev: Device to handle.
2697 *
2698 * Choose the power state appropriate for the device depending on whether
2699 * it can wake up the system and/or is power manageable by the platform
2700 * (PCI_D3hot is the default) and put the device into that state.
2701 */
2702int pci_prepare_to_sleep(struct pci_dev *dev)
2703{
2704 bool wakeup = device_may_wakeup(&dev->dev);
2705 pci_power_t target_state = pci_target_state(dev, wakeup);
2706 int error;
2707
2708 if (target_state == PCI_POWER_ERROR)
2709 return -EIO;
2710
2711 pci_enable_wake(dev, target_state, wakeup);
2712
2713 error = pci_set_power_state(dev, target_state);
2714
2715 if (error)
2716 pci_enable_wake(dev, target_state, false);
2717
2718 return error;
2719}
2720EXPORT_SYMBOL(pci_prepare_to_sleep);
2721
2722/**
2723 * pci_back_from_sleep - turn PCI device on during system-wide transition
2724 * into working state
2725 * @dev: Device to handle.
2726 *
2727 * Disable device's system wake-up capability and put it into D0.
2728 */
2729int pci_back_from_sleep(struct pci_dev *dev)
2730{
2731 int ret = pci_set_power_state(dev, PCI_D0);
2732
2733 if (ret)
2734 return ret;
2735
2736 pci_enable_wake(dev, PCI_D0, false);
2737 return 0;
2738}
2739EXPORT_SYMBOL(pci_back_from_sleep);
2740
2741/**
2742 * pci_finish_runtime_suspend - Carry out PCI-specific part of runtime suspend.
2743 * @dev: PCI device being suspended.
2744 *
2745 * Prepare @dev to generate wake-up events at run time and put it into a low
2746 * power state.
2747 */
2748int pci_finish_runtime_suspend(struct pci_dev *dev)
2749{
2750 pci_power_t target_state;
2751 int error;
2752
2753 target_state = pci_target_state(dev, device_can_wakeup(&dev->dev));
2754 if (target_state == PCI_POWER_ERROR)
2755 return -EIO;
2756
2757 __pci_enable_wake(dev, target_state, pci_dev_run_wake(dev));
2758
2759 error = pci_set_power_state(dev, target_state);
2760
2761 if (error)
2762 pci_enable_wake(dev, target_state, false);
2763
2764 return error;
2765}
2766
2767/**
2768 * pci_dev_run_wake - Check if device can generate run-time wake-up events.
2769 * @dev: Device to check.
2770 *
2771 * Return true if the device itself is capable of generating wake-up events
2772 * (through the platform or using the native PCIe PME) or if the device supports
2773 * PME and one of its upstream bridges can generate wake-up events.
2774 */
2775bool pci_dev_run_wake(struct pci_dev *dev)
2776{
2777 struct pci_bus *bus = dev->bus;
2778
2779 if (!dev->pme_support)
2780 return false;
2781
2782 /* PME-capable in principle, but not from the target power state */
2783 if (!pci_pme_capable(dev, pci_target_state(dev, true)))
2784 return false;
2785
2786 if (device_can_wakeup(&dev->dev))
2787 return true;
2788
2789 while (bus->parent) {
2790 struct pci_dev *bridge = bus->self;
2791
2792 if (device_can_wakeup(&bridge->dev))
2793 return true;
2794
2795 bus = bus->parent;
2796 }
2797
2798 /* We have reached the root bus. */
2799 if (bus->bridge)
2800 return device_can_wakeup(bus->bridge);
2801
2802 return false;
2803}
2804EXPORT_SYMBOL_GPL(pci_dev_run_wake);
2805
2806/**
2807 * pci_dev_need_resume - Check if it is necessary to resume the device.
2808 * @pci_dev: Device to check.
2809 *
2810 * Return 'true' if the device is not runtime-suspended or it has to be
2811 * reconfigured due to wakeup settings difference between system and runtime
2812 * suspend, or the current power state of it is not suitable for the upcoming
2813 * (system-wide) transition.
2814 */
2815bool pci_dev_need_resume(struct pci_dev *pci_dev)
2816{
2817 struct device *dev = &pci_dev->dev;
2818 pci_power_t target_state;
2819
2820 if (!pm_runtime_suspended(dev) || platform_pci_need_resume(pci_dev))
2821 return true;
2822
2823 target_state = pci_target_state(pci_dev, device_may_wakeup(dev));
2824
2825 /*
2826 * If the earlier platform check has not triggered, D3cold is just power
2827 * removal on top of D3hot, so no need to resume the device in that
2828 * case.
2829 */
2830 return target_state != pci_dev->current_state &&
2831 target_state != PCI_D3cold &&
2832 pci_dev->current_state != PCI_D3hot;
2833}
2834
2835/**
2836 * pci_dev_adjust_pme - Adjust PME setting for a suspended device.
2837 * @pci_dev: Device to check.
2838 *
2839 * If the device is suspended and it is not configured for system wakeup,
2840 * disable PME for it to prevent it from waking up the system unnecessarily.
2841 *
2842 * Note that if the device's power state is D3cold and the platform check in
2843 * pci_dev_need_resume() has not triggered, the device's configuration need not
2844 * be changed.
2845 */
2846void pci_dev_adjust_pme(struct pci_dev *pci_dev)
2847{
2848 struct device *dev = &pci_dev->dev;
2849
2850 spin_lock_irq(&dev->power.lock);
2851
2852 if (pm_runtime_suspended(dev) && !device_may_wakeup(dev) &&
2853 pci_dev->current_state < PCI_D3cold)
2854 __pci_pme_active(pci_dev, false);
2855
2856 spin_unlock_irq(&dev->power.lock);
2857}
2858
2859/**
2860 * pci_dev_complete_resume - Finalize resume from system sleep for a device.
2861 * @pci_dev: Device to handle.
2862 *
2863 * If the device is runtime suspended and wakeup-capable, enable PME for it as
2864 * it might have been disabled during the prepare phase of system suspend if
2865 * the device was not configured for system wakeup.
2866 */
2867void pci_dev_complete_resume(struct pci_dev *pci_dev)
2868{
2869 struct device *dev = &pci_dev->dev;
2870
2871 if (!pci_dev_run_wake(pci_dev))
2872 return;
2873
2874 spin_lock_irq(&dev->power.lock);
2875
2876 if (pm_runtime_suspended(dev) && pci_dev->current_state < PCI_D3cold)
2877 __pci_pme_active(pci_dev, true);
2878
2879 spin_unlock_irq(&dev->power.lock);
2880}
2881
2882/**
2883 * pci_choose_state - Choose the power state of a PCI device.
2884 * @dev: Target PCI device.
2885 * @state: Target state for the whole system.
2886 *
2887 * Returns PCI power state suitable for @dev and @state.
2888 */
2889pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state)
2890{
2891 if (state.event == PM_EVENT_ON)
2892 return PCI_D0;
2893
2894 return pci_target_state(dev, false);
2895}
2896EXPORT_SYMBOL(pci_choose_state);
2897
2898void pci_config_pm_runtime_get(struct pci_dev *pdev)
2899{
2900 struct device *dev = &pdev->dev;
2901 struct device *parent = dev->parent;
2902
2903 if (parent)
2904 pm_runtime_get_sync(parent);
2905 pm_runtime_get_noresume(dev);
2906 /*
2907 * pdev->current_state is set to PCI_D3cold during suspending,
2908 * so wait until suspending completes
2909 */
2910 pm_runtime_barrier(dev);
2911 /*
2912 * Only need to resume devices in D3cold, because config
2913 * registers are still accessible for devices suspended but
2914 * not in D3cold.
2915 */
2916 if (pdev->current_state == PCI_D3cold)
2917 pm_runtime_resume(dev);
2918}
2919
2920void pci_config_pm_runtime_put(struct pci_dev *pdev)
2921{
2922 struct device *dev = &pdev->dev;
2923 struct device *parent = dev->parent;
2924
2925 pm_runtime_put(dev);
2926 if (parent)
2927 pm_runtime_put_sync(parent);
2928}
2929
2930static const struct dmi_system_id bridge_d3_blacklist[] = {
2931#ifdef CONFIG_X86
2932 {
2933 /*
2934 * Gigabyte X299 root port is not marked as hotplug capable
2935 * which allows Linux to power manage it. However, this
2936 * confuses the BIOS SMI handler so don't power manage root
2937 * ports on that system.
2938 */
2939 .ident = "X299 DESIGNARE EX-CF",
2940 .matches = {
2941 DMI_MATCH(DMI_BOARD_VENDOR, "Gigabyte Technology Co., Ltd."),
2942 DMI_MATCH(DMI_BOARD_NAME, "X299 DESIGNARE EX-CF"),
2943 },
2944 },
2945 {
2946 /*
2947 * Downstream device is not accessible after putting a root port
2948 * into D3cold and back into D0 on Elo i2.
2949 */
2950 .ident = "Elo i2",
2951 .matches = {
2952 DMI_MATCH(DMI_SYS_VENDOR, "Elo Touch Solutions"),
2953 DMI_MATCH(DMI_PRODUCT_NAME, "Elo i2"),
2954 DMI_MATCH(DMI_PRODUCT_VERSION, "RevB"),
2955 },
2956 },
2957#endif
2958 { }
2959};
2960
2961/**
2962 * pci_bridge_d3_possible - Is it possible to put the bridge into D3
2963 * @bridge: Bridge to check
2964 *
2965 * This function checks if it is possible to move the bridge to D3.
2966 * Currently we only allow D3 for recent enough PCIe ports and Thunderbolt.
2967 */
2968bool pci_bridge_d3_possible(struct pci_dev *bridge)
2969{
2970 if (!pci_is_pcie(bridge))
2971 return false;
2972
2973 switch (pci_pcie_type(bridge)) {
2974 case PCI_EXP_TYPE_ROOT_PORT:
2975 case PCI_EXP_TYPE_UPSTREAM:
2976 case PCI_EXP_TYPE_DOWNSTREAM:
2977 if (pci_bridge_d3_disable)
2978 return false;
2979
2980 /*
2981 * Hotplug ports handled by firmware in System Management Mode
2982 * may not be put into D3 by the OS (Thunderbolt on non-Macs).
2983 */
2984 if (bridge->is_hotplug_bridge && !pciehp_is_native(bridge))
2985 return false;
2986
2987 if (pci_bridge_d3_force)
2988 return true;
2989
2990 /* Even the oldest 2010 Thunderbolt controller supports D3. */
2991 if (bridge->is_thunderbolt)
2992 return true;
2993
2994 /* Platform might know better if the bridge supports D3 */
2995 if (platform_pci_bridge_d3(bridge))
2996 return true;
2997
2998 /*
2999 * Hotplug ports handled natively by the OS were not validated
3000 * by vendors for runtime D3 at least until 2018 because there
3001 * was no OS support.
3002 */
3003 if (bridge->is_hotplug_bridge)
3004 return false;
3005
3006 if (dmi_check_system(bridge_d3_blacklist))
3007 return false;
3008
3009 /*
3010 * It should be safe to put PCIe ports from 2015 or newer
3011 * to D3.
3012 */
3013 if (dmi_get_bios_year() >= 2015)
3014 return true;
3015 break;
3016 }
3017
3018 return false;
3019}
3020
3021static int pci_dev_check_d3cold(struct pci_dev *dev, void *data)
3022{
3023 bool *d3cold_ok = data;
3024
3025 if (/* The device needs to be allowed to go D3cold ... */
3026 dev->no_d3cold || !dev->d3cold_allowed ||
3027
3028 /* ... and if it is wakeup capable to do so from D3cold. */
3029 (device_may_wakeup(&dev->dev) &&
3030 !pci_pme_capable(dev, PCI_D3cold)) ||
3031
3032 /* If it is a bridge it must be allowed to go to D3. */
3033 !pci_power_manageable(dev))
3034
3035 *d3cold_ok = false;
3036
3037 return !*d3cold_ok;
3038}
3039
3040/*
3041 * pci_bridge_d3_update - Update bridge D3 capabilities
3042 * @dev: PCI device which is changed
3043 *
3044 * Update upstream bridge PM capabilities accordingly depending on if the
3045 * device PM configuration was changed or the device is being removed. The
3046 * change is also propagated upstream.
3047 */
3048void pci_bridge_d3_update(struct pci_dev *dev)
3049{
3050 bool remove = !device_is_registered(&dev->dev);
3051 struct pci_dev *bridge;
3052 bool d3cold_ok = true;
3053
3054 bridge = pci_upstream_bridge(dev);
3055 if (!bridge || !pci_bridge_d3_possible(bridge))
3056 return;
3057
3058 /*
3059 * If D3 is currently allowed for the bridge, removing one of its
3060 * children won't change that.
3061 */
3062 if (remove && bridge->bridge_d3)
3063 return;
3064
3065 /*
3066 * If D3 is currently allowed for the bridge and a child is added or
3067 * changed, disallowance of D3 can only be caused by that child, so
3068 * we only need to check that single device, not any of its siblings.
3069 *
3070 * If D3 is currently not allowed for the bridge, checking the device
3071 * first may allow us to skip checking its siblings.
3072 */
3073 if (!remove)
3074 pci_dev_check_d3cold(dev, &d3cold_ok);
3075
3076 /*
3077 * If D3 is currently not allowed for the bridge, this may be caused
3078 * either by the device being changed/removed or any of its siblings,
3079 * so we need to go through all children to find out if one of them
3080 * continues to block D3.
3081 */
3082 if (d3cold_ok && !bridge->bridge_d3)
3083 pci_walk_bus(bridge->subordinate, pci_dev_check_d3cold,
3084 &d3cold_ok);
3085
3086 if (bridge->bridge_d3 != d3cold_ok) {
3087 bridge->bridge_d3 = d3cold_ok;
3088 /* Propagate change to upstream bridges */
3089 pci_bridge_d3_update(bridge);
3090 }
3091}
3092
3093/**
3094 * pci_d3cold_enable - Enable D3cold for device
3095 * @dev: PCI device to handle
3096 *
3097 * This function can be used in drivers to enable D3cold from the device
3098 * they handle. It also updates upstream PCI bridge PM capabilities
3099 * accordingly.
3100 */
3101void pci_d3cold_enable(struct pci_dev *dev)
3102{
3103 if (dev->no_d3cold) {
3104 dev->no_d3cold = false;
3105 pci_bridge_d3_update(dev);
3106 }
3107}
3108EXPORT_SYMBOL_GPL(pci_d3cold_enable);
3109
3110/**
3111 * pci_d3cold_disable - Disable D3cold for device
3112 * @dev: PCI device to handle
3113 *
3114 * This function can be used in drivers to disable D3cold from the device
3115 * they handle. It also updates upstream PCI bridge PM capabilities
3116 * accordingly.
3117 */
3118void pci_d3cold_disable(struct pci_dev *dev)
3119{
3120 if (!dev->no_d3cold) {
3121 dev->no_d3cold = true;
3122 pci_bridge_d3_update(dev);
3123 }
3124}
3125EXPORT_SYMBOL_GPL(pci_d3cold_disable);
3126
3127/**
3128 * pci_pm_init - Initialize PM functions of given PCI device
3129 * @dev: PCI device to handle.
3130 */
3131void pci_pm_init(struct pci_dev *dev)
3132{
3133 int pm;
3134 u16 status;
3135 u16 pmc;
3136
3137 pm_runtime_forbid(&dev->dev);
3138 pm_runtime_set_active(&dev->dev);
3139 pm_runtime_enable(&dev->dev);
3140 device_enable_async_suspend(&dev->dev);
3141 dev->wakeup_prepared = false;
3142
3143 dev->pm_cap = 0;
3144 dev->pme_support = 0;
3145
3146 /* find PCI PM capability in list */
3147 pm = pci_find_capability(dev, PCI_CAP_ID_PM);
3148 if (!pm)
3149 return;
3150 /* Check device's ability to generate PME# */
3151 pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
3152
3153 if ((pmc & PCI_PM_CAP_VER_MASK) > 3) {
3154 pci_err(dev, "unsupported PM cap regs version (%u)\n",
3155 pmc & PCI_PM_CAP_VER_MASK);
3156 return;
3157 }
3158
3159 dev->pm_cap = pm;
3160 dev->d3hot_delay = PCI_PM_D3HOT_WAIT;
3161 dev->d3cold_delay = PCI_PM_D3COLD_WAIT;
3162 dev->bridge_d3 = pci_bridge_d3_possible(dev);
3163 dev->d3cold_allowed = true;
3164
3165 dev->d1_support = false;
3166 dev->d2_support = false;
3167 if (!pci_no_d1d2(dev)) {
3168 if (pmc & PCI_PM_CAP_D1)
3169 dev->d1_support = true;
3170 if (pmc & PCI_PM_CAP_D2)
3171 dev->d2_support = true;
3172
3173 if (dev->d1_support || dev->d2_support)
3174 pci_info(dev, "supports%s%s\n",
3175 dev->d1_support ? " D1" : "",
3176 dev->d2_support ? " D2" : "");
3177 }
3178
3179 pmc &= PCI_PM_CAP_PME_MASK;
3180 if (pmc) {
3181 pci_info(dev, "PME# supported from%s%s%s%s%s\n",
3182 (pmc & PCI_PM_CAP_PME_D0) ? " D0" : "",
3183 (pmc & PCI_PM_CAP_PME_D1) ? " D1" : "",
3184 (pmc & PCI_PM_CAP_PME_D2) ? " D2" : "",
3185 (pmc & PCI_PM_CAP_PME_D3hot) ? " D3hot" : "",
3186 (pmc & PCI_PM_CAP_PME_D3cold) ? " D3cold" : "");
3187 dev->pme_support = pmc >> PCI_PM_CAP_PME_SHIFT;
3188 dev->pme_poll = true;
3189 /*
3190 * Make device's PM flags reflect the wake-up capability, but
3191 * let the user space enable it to wake up the system as needed.
3192 */
3193 device_set_wakeup_capable(&dev->dev, true);
3194 /* Disable the PME# generation functionality */
3195 pci_pme_active(dev, false);
3196 }
3197
3198 pci_read_config_word(dev, PCI_STATUS, &status);
3199 if (status & PCI_STATUS_IMM_READY)
3200 dev->imm_ready = 1;
3201}
3202
3203static unsigned long pci_ea_flags(struct pci_dev *dev, u8 prop)
3204{
3205 unsigned long flags = IORESOURCE_PCI_FIXED | IORESOURCE_PCI_EA_BEI;
3206
3207 switch (prop) {
3208 case PCI_EA_P_MEM:
3209 case PCI_EA_P_VF_MEM:
3210 flags |= IORESOURCE_MEM;
3211 break;
3212 case PCI_EA_P_MEM_PREFETCH:
3213 case PCI_EA_P_VF_MEM_PREFETCH:
3214 flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH;
3215 break;
3216 case PCI_EA_P_IO:
3217 flags |= IORESOURCE_IO;
3218 break;
3219 default:
3220 return 0;
3221 }
3222
3223 return flags;
3224}
3225
3226static struct resource *pci_ea_get_resource(struct pci_dev *dev, u8 bei,
3227 u8 prop)
3228{
3229 if (bei <= PCI_EA_BEI_BAR5 && prop <= PCI_EA_P_IO)
3230 return &dev->resource[bei];
3231#ifdef CONFIG_PCI_IOV
3232 else if (bei >= PCI_EA_BEI_VF_BAR0 && bei <= PCI_EA_BEI_VF_BAR5 &&
3233 (prop == PCI_EA_P_VF_MEM || prop == PCI_EA_P_VF_MEM_PREFETCH))
3234 return &dev->resource[PCI_IOV_RESOURCES +
3235 bei - PCI_EA_BEI_VF_BAR0];
3236#endif
3237 else if (bei == PCI_EA_BEI_ROM)
3238 return &dev->resource[PCI_ROM_RESOURCE];
3239 else
3240 return NULL;
3241}
3242
3243/* Read an Enhanced Allocation (EA) entry */
3244static int pci_ea_read(struct pci_dev *dev, int offset)
3245{
3246 struct resource *res;
3247 int ent_size, ent_offset = offset;
3248 resource_size_t start, end;
3249 unsigned long flags;
3250 u32 dw0, bei, base, max_offset;
3251 u8 prop;
3252 bool support_64 = (sizeof(resource_size_t) >= 8);
3253
3254 pci_read_config_dword(dev, ent_offset, &dw0);
3255 ent_offset += 4;
3256
3257 /* Entry size field indicates DWORDs after 1st */
3258 ent_size = ((dw0 & PCI_EA_ES) + 1) << 2;
3259
3260 if (!(dw0 & PCI_EA_ENABLE)) /* Entry not enabled */
3261 goto out;
3262
3263 bei = (dw0 & PCI_EA_BEI) >> 4;
3264 prop = (dw0 & PCI_EA_PP) >> 8;
3265
3266 /*
3267 * If the Property is in the reserved range, try the Secondary
3268 * Property instead.
3269 */
3270 if (prop > PCI_EA_P_BRIDGE_IO && prop < PCI_EA_P_MEM_RESERVED)
3271 prop = (dw0 & PCI_EA_SP) >> 16;
3272 if (prop > PCI_EA_P_BRIDGE_IO)
3273 goto out;
3274
3275 res = pci_ea_get_resource(dev, bei, prop);
3276 if (!res) {
3277 pci_err(dev, "Unsupported EA entry BEI: %u\n", bei);
3278 goto out;
3279 }
3280
3281 flags = pci_ea_flags(dev, prop);
3282 if (!flags) {
3283 pci_err(dev, "Unsupported EA properties: %#x\n", prop);
3284 goto out;
3285 }
3286
3287 /* Read Base */
3288 pci_read_config_dword(dev, ent_offset, &base);
3289 start = (base & PCI_EA_FIELD_MASK);
3290 ent_offset += 4;
3291
3292 /* Read MaxOffset */
3293 pci_read_config_dword(dev, ent_offset, &max_offset);
3294 ent_offset += 4;
3295
3296 /* Read Base MSBs (if 64-bit entry) */
3297 if (base & PCI_EA_IS_64) {
3298 u32 base_upper;
3299
3300 pci_read_config_dword(dev, ent_offset, &base_upper);
3301 ent_offset += 4;
3302
3303 flags |= IORESOURCE_MEM_64;
3304
3305 /* entry starts above 32-bit boundary, can't use */
3306 if (!support_64 && base_upper)
3307 goto out;
3308
3309 if (support_64)
3310 start |= ((u64)base_upper << 32);
3311 }
3312
3313 end = start + (max_offset | 0x03);
3314
3315 /* Read MaxOffset MSBs (if 64-bit entry) */
3316 if (max_offset & PCI_EA_IS_64) {
3317 u32 max_offset_upper;
3318
3319 pci_read_config_dword(dev, ent_offset, &max_offset_upper);
3320 ent_offset += 4;
3321
3322 flags |= IORESOURCE_MEM_64;
3323
3324 /* entry too big, can't use */
3325 if (!support_64 && max_offset_upper)
3326 goto out;
3327
3328 if (support_64)
3329 end += ((u64)max_offset_upper << 32);
3330 }
3331
3332 if (end < start) {
3333 pci_err(dev, "EA Entry crosses address boundary\n");
3334 goto out;
3335 }
3336
3337 if (ent_size != ent_offset - offset) {
3338 pci_err(dev, "EA Entry Size (%d) does not match length read (%d)\n",
3339 ent_size, ent_offset - offset);
3340 goto out;
3341 }
3342
3343 res->name = pci_name(dev);
3344 res->start = start;
3345 res->end = end;
3346 res->flags = flags;
3347
3348 if (bei <= PCI_EA_BEI_BAR5)
3349 pci_info(dev, "BAR %d: %pR (from Enhanced Allocation, properties %#02x)\n",
3350 bei, res, prop);
3351 else if (bei == PCI_EA_BEI_ROM)
3352 pci_info(dev, "ROM: %pR (from Enhanced Allocation, properties %#02x)\n",
3353 res, prop);
3354 else if (bei >= PCI_EA_BEI_VF_BAR0 && bei <= PCI_EA_BEI_VF_BAR5)
3355 pci_info(dev, "VF BAR %d: %pR (from Enhanced Allocation, properties %#02x)\n",
3356 bei - PCI_EA_BEI_VF_BAR0, res, prop);
3357 else
3358 pci_info(dev, "BEI %d res: %pR (from Enhanced Allocation, properties %#02x)\n",
3359 bei, res, prop);
3360
3361out:
3362 return offset + ent_size;
3363}
3364
3365/* Enhanced Allocation Initialization */
3366void pci_ea_init(struct pci_dev *dev)
3367{
3368 int ea;
3369 u8 num_ent;
3370 int offset;
3371 int i;
3372
3373 /* find PCI EA capability in list */
3374 ea = pci_find_capability(dev, PCI_CAP_ID_EA);
3375 if (!ea)
3376 return;
3377
3378 /* determine the number of entries */
3379 pci_bus_read_config_byte(dev->bus, dev->devfn, ea + PCI_EA_NUM_ENT,
3380 &num_ent);
3381 num_ent &= PCI_EA_NUM_ENT_MASK;
3382
3383 offset = ea + PCI_EA_FIRST_ENT;
3384
3385 /* Skip DWORD 2 for type 1 functions */
3386 if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)
3387 offset += 4;
3388
3389 /* parse each EA entry */
3390 for (i = 0; i < num_ent; ++i)
3391 offset = pci_ea_read(dev, offset);
3392}
3393
3394static void pci_add_saved_cap(struct pci_dev *pci_dev,
3395 struct pci_cap_saved_state *new_cap)
3396{
3397 hlist_add_head(&new_cap->next, &pci_dev->saved_cap_space);
3398}
3399
3400/**
3401 * _pci_add_cap_save_buffer - allocate buffer for saving given
3402 * capability registers
3403 * @dev: the PCI device
3404 * @cap: the capability to allocate the buffer for
3405 * @extended: Standard or Extended capability ID
3406 * @size: requested size of the buffer
3407 */
3408static int _pci_add_cap_save_buffer(struct pci_dev *dev, u16 cap,
3409 bool extended, unsigned int size)
3410{
3411 int pos;
3412 struct pci_cap_saved_state *save_state;
3413
3414 if (extended)
3415 pos = pci_find_ext_capability(dev, cap);
3416 else
3417 pos = pci_find_capability(dev, cap);
3418
3419 if (!pos)
3420 return 0;
3421
3422 save_state = kzalloc(sizeof(*save_state) + size, GFP_KERNEL);
3423 if (!save_state)
3424 return -ENOMEM;
3425
3426 save_state->cap.cap_nr = cap;
3427 save_state->cap.cap_extended = extended;
3428 save_state->cap.size = size;
3429 pci_add_saved_cap(dev, save_state);
3430
3431 return 0;
3432}
3433
3434int pci_add_cap_save_buffer(struct pci_dev *dev, char cap, unsigned int size)
3435{
3436 return _pci_add_cap_save_buffer(dev, cap, false, size);
3437}
3438
3439int pci_add_ext_cap_save_buffer(struct pci_dev *dev, u16 cap, unsigned int size)
3440{
3441 return _pci_add_cap_save_buffer(dev, cap, true, size);
3442}
3443
3444/**
3445 * pci_allocate_cap_save_buffers - allocate buffers for saving capabilities
3446 * @dev: the PCI device
3447 */
3448void pci_allocate_cap_save_buffers(struct pci_dev *dev)
3449{
3450 int error;
3451
3452 error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_EXP,
3453 PCI_EXP_SAVE_REGS * sizeof(u16));
3454 if (error)
3455 pci_err(dev, "unable to preallocate PCI Express save buffer\n");
3456
3457 error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_PCIX, sizeof(u16));
3458 if (error)
3459 pci_err(dev, "unable to preallocate PCI-X save buffer\n");
3460
3461 error = pci_add_ext_cap_save_buffer(dev, PCI_EXT_CAP_ID_LTR,
3462 2 * sizeof(u16));
3463 if (error)
3464 pci_err(dev, "unable to allocate suspend buffer for LTR\n");
3465
3466 pci_allocate_vc_save_buffers(dev);
3467}
3468
3469void pci_free_cap_save_buffers(struct pci_dev *dev)
3470{
3471 struct pci_cap_saved_state *tmp;
3472 struct hlist_node *n;
3473
3474 hlist_for_each_entry_safe(tmp, n, &dev->saved_cap_space, next)
3475 kfree(tmp);
3476}
3477
3478/**
3479 * pci_configure_ari - enable or disable ARI forwarding
3480 * @dev: the PCI device
3481 *
3482 * If @dev and its upstream bridge both support ARI, enable ARI in the
3483 * bridge. Otherwise, disable ARI in the bridge.
3484 */
3485void pci_configure_ari(struct pci_dev *dev)
3486{
3487 u32 cap;
3488 struct pci_dev *bridge;
3489
3490 if (pcie_ari_disabled || !pci_is_pcie(dev) || dev->devfn)
3491 return;
3492
3493 bridge = dev->bus->self;
3494 if (!bridge)
3495 return;
3496
3497 pcie_capability_read_dword(bridge, PCI_EXP_DEVCAP2, &cap);
3498 if (!(cap & PCI_EXP_DEVCAP2_ARI))
3499 return;
3500
3501 if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI)) {
3502 pcie_capability_set_word(bridge, PCI_EXP_DEVCTL2,
3503 PCI_EXP_DEVCTL2_ARI);
3504 bridge->ari_enabled = 1;
3505 } else {
3506 pcie_capability_clear_word(bridge, PCI_EXP_DEVCTL2,
3507 PCI_EXP_DEVCTL2_ARI);
3508 bridge->ari_enabled = 0;
3509 }
3510}
3511
3512static bool pci_acs_flags_enabled(struct pci_dev *pdev, u16 acs_flags)
3513{
3514 int pos;
3515 u16 cap, ctrl;
3516
3517 pos = pdev->acs_cap;
3518 if (!pos)
3519 return false;
3520
3521 /*
3522 * Except for egress control, capabilities are either required
3523 * or only required if controllable. Features missing from the
3524 * capability field can therefore be assumed as hard-wired enabled.
3525 */
3526 pci_read_config_word(pdev, pos + PCI_ACS_CAP, &cap);
3527 acs_flags &= (cap | PCI_ACS_EC);
3528
3529 pci_read_config_word(pdev, pos + PCI_ACS_CTRL, &ctrl);
3530 return (ctrl & acs_flags) == acs_flags;
3531}
3532
3533/**
3534 * pci_acs_enabled - test ACS against required flags for a given device
3535 * @pdev: device to test
3536 * @acs_flags: required PCI ACS flags
3537 *
3538 * Return true if the device supports the provided flags. Automatically
3539 * filters out flags that are not implemented on multifunction devices.
3540 *
3541 * Note that this interface checks the effective ACS capabilities of the
3542 * device rather than the actual capabilities. For instance, most single
3543 * function endpoints are not required to support ACS because they have no
3544 * opportunity for peer-to-peer access. We therefore return 'true'
3545 * regardless of whether the device exposes an ACS capability. This makes
3546 * it much easier for callers of this function to ignore the actual type
3547 * or topology of the device when testing ACS support.
3548 */
3549bool pci_acs_enabled(struct pci_dev *pdev, u16 acs_flags)
3550{
3551 int ret;
3552
3553 ret = pci_dev_specific_acs_enabled(pdev, acs_flags);
3554 if (ret >= 0)
3555 return ret > 0;
3556
3557 /*
3558 * Conventional PCI and PCI-X devices never support ACS, either
3559 * effectively or actually. The shared bus topology implies that
3560 * any device on the bus can receive or snoop DMA.
3561 */
3562 if (!pci_is_pcie(pdev))
3563 return false;
3564
3565 switch (pci_pcie_type(pdev)) {
3566 /*
3567 * PCI/X-to-PCIe bridges are not specifically mentioned by the spec,
3568 * but since their primary interface is PCI/X, we conservatively
3569 * handle them as we would a non-PCIe device.
3570 */
3571 case PCI_EXP_TYPE_PCIE_BRIDGE:
3572 /*
3573 * PCIe 3.0, 6.12.1 excludes ACS on these devices. "ACS is never
3574 * applicable... must never implement an ACS Extended Capability...".
3575 * This seems arbitrary, but we take a conservative interpretation
3576 * of this statement.
3577 */
3578 case PCI_EXP_TYPE_PCI_BRIDGE:
3579 case PCI_EXP_TYPE_RC_EC:
3580 return false;
3581 /*
3582 * PCIe 3.0, 6.12.1.1 specifies that downstream and root ports should
3583 * implement ACS in order to indicate their peer-to-peer capabilities,
3584 * regardless of whether they are single- or multi-function devices.
3585 */
3586 case PCI_EXP_TYPE_DOWNSTREAM:
3587 case PCI_EXP_TYPE_ROOT_PORT:
3588 return pci_acs_flags_enabled(pdev, acs_flags);
3589 /*
3590 * PCIe 3.0, 6.12.1.2 specifies ACS capabilities that should be
3591 * implemented by the remaining PCIe types to indicate peer-to-peer
3592 * capabilities, but only when they are part of a multifunction
3593 * device. The footnote for section 6.12 indicates the specific
3594 * PCIe types included here.
3595 */
3596 case PCI_EXP_TYPE_ENDPOINT:
3597 case PCI_EXP_TYPE_UPSTREAM:
3598 case PCI_EXP_TYPE_LEG_END:
3599 case PCI_EXP_TYPE_RC_END:
3600 if (!pdev->multifunction)
3601 break;
3602
3603 return pci_acs_flags_enabled(pdev, acs_flags);
3604 }
3605
3606 /*
3607 * PCIe 3.0, 6.12.1.3 specifies no ACS capabilities are applicable
3608 * to single function devices with the exception of downstream ports.
3609 */
3610 return true;
3611}
3612
3613/**
3614 * pci_acs_path_enabled - test ACS flags from start to end in a hierarchy
3615 * @start: starting downstream device
3616 * @end: ending upstream device or NULL to search to the root bus
3617 * @acs_flags: required flags
3618 *
3619 * Walk up a device tree from start to end testing PCI ACS support. If
3620 * any step along the way does not support the required flags, return false.
3621 */
3622bool pci_acs_path_enabled(struct pci_dev *start,
3623 struct pci_dev *end, u16 acs_flags)
3624{
3625 struct pci_dev *pdev, *parent = start;
3626
3627 do {
3628 pdev = parent;
3629
3630 if (!pci_acs_enabled(pdev, acs_flags))
3631 return false;
3632
3633 if (pci_is_root_bus(pdev->bus))
3634 return (end == NULL);
3635
3636 parent = pdev->bus->self;
3637 } while (pdev != end);
3638
3639 return true;
3640}
3641
3642/**
3643 * pci_acs_init - Initialize ACS if hardware supports it
3644 * @dev: the PCI device
3645 */
3646void pci_acs_init(struct pci_dev *dev)
3647{
3648 dev->acs_cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS);
3649
3650 /*
3651 * Attempt to enable ACS regardless of capability because some Root
3652 * Ports (e.g. those quirked with *_intel_pch_acs_*) do not have
3653 * the standard ACS capability but still support ACS via those
3654 * quirks.
3655 */
3656 pci_enable_acs(dev);
3657}
3658
3659/**
3660 * pci_rebar_find_pos - find position of resize ctrl reg for BAR
3661 * @pdev: PCI device
3662 * @bar: BAR to find
3663 *
3664 * Helper to find the position of the ctrl register for a BAR.
3665 * Returns -ENOTSUPP if resizable BARs are not supported at all.
3666 * Returns -ENOENT if no ctrl register for the BAR could be found.
3667 */
3668static int pci_rebar_find_pos(struct pci_dev *pdev, int bar)
3669{
3670 unsigned int pos, nbars, i;
3671 u32 ctrl;
3672
3673 pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR);
3674 if (!pos)
3675 return -ENOTSUPP;
3676
3677 pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
3678 nbars = (ctrl & PCI_REBAR_CTRL_NBAR_MASK) >>
3679 PCI_REBAR_CTRL_NBAR_SHIFT;
3680
3681 for (i = 0; i < nbars; i++, pos += 8) {
3682 int bar_idx;
3683
3684 pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
3685 bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX;
3686 if (bar_idx == bar)
3687 return pos;
3688 }
3689
3690 return -ENOENT;
3691}
3692
3693/**
3694 * pci_rebar_get_possible_sizes - get possible sizes for BAR
3695 * @pdev: PCI device
3696 * @bar: BAR to query
3697 *
3698 * Get the possible sizes of a resizable BAR as bitmask defined in the spec
3699 * (bit 0=1MB, bit 19=512GB). Returns 0 if BAR isn't resizable.
3700 */
3701u32 pci_rebar_get_possible_sizes(struct pci_dev *pdev, int bar)
3702{
3703 int pos;
3704 u32 cap;
3705
3706 pos = pci_rebar_find_pos(pdev, bar);
3707 if (pos < 0)
3708 return 0;
3709
3710 pci_read_config_dword(pdev, pos + PCI_REBAR_CAP, &cap);
3711 cap &= PCI_REBAR_CAP_SIZES;
3712
3713 /* Sapphire RX 5600 XT Pulse has an invalid cap dword for BAR 0 */
3714 if (pdev->vendor == PCI_VENDOR_ID_ATI && pdev->device == 0x731f &&
3715 bar == 0 && cap == 0x7000)
3716 cap = 0x3f000;
3717
3718 return cap >> 4;
3719}
3720EXPORT_SYMBOL(pci_rebar_get_possible_sizes);
3721
3722/**
3723 * pci_rebar_get_current_size - get the current size of a BAR
3724 * @pdev: PCI device
3725 * @bar: BAR to set size to
3726 *
3727 * Read the size of a BAR from the resizable BAR config.
3728 * Returns size if found or negative error code.
3729 */
3730int pci_rebar_get_current_size(struct pci_dev *pdev, int bar)
3731{
3732 int pos;
3733 u32 ctrl;
3734
3735 pos = pci_rebar_find_pos(pdev, bar);
3736 if (pos < 0)
3737 return pos;
3738
3739 pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
3740 return (ctrl & PCI_REBAR_CTRL_BAR_SIZE) >> PCI_REBAR_CTRL_BAR_SHIFT;
3741}
3742
3743/**
3744 * pci_rebar_set_size - set a new size for a BAR
3745 * @pdev: PCI device
3746 * @bar: BAR to set size to
3747 * @size: new size as defined in the spec (0=1MB, 19=512GB)
3748 *
3749 * Set the new size of a BAR as defined in the spec.
3750 * Returns zero if resizing was successful, error code otherwise.
3751 */
3752int pci_rebar_set_size(struct pci_dev *pdev, int bar, int size)
3753{
3754 int pos;
3755 u32 ctrl;
3756
3757 pos = pci_rebar_find_pos(pdev, bar);
3758 if (pos < 0)
3759 return pos;
3760
3761 pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
3762 ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE;
3763 ctrl |= size << PCI_REBAR_CTRL_BAR_SHIFT;
3764 pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl);
3765 return 0;
3766}
3767
3768/**
3769 * pci_enable_atomic_ops_to_root - enable AtomicOp requests to root port
3770 * @dev: the PCI device
3771 * @cap_mask: mask of desired AtomicOp sizes, including one or more of:
3772 * PCI_EXP_DEVCAP2_ATOMIC_COMP32
3773 * PCI_EXP_DEVCAP2_ATOMIC_COMP64
3774 * PCI_EXP_DEVCAP2_ATOMIC_COMP128
3775 *
3776 * Return 0 if all upstream bridges support AtomicOp routing, egress
3777 * blocking is disabled on all upstream ports, and the root port supports
3778 * the requested completion capabilities (32-bit, 64-bit and/or 128-bit
3779 * AtomicOp completion), or negative otherwise.
3780 */
3781int pci_enable_atomic_ops_to_root(struct pci_dev *dev, u32 cap_mask)
3782{
3783 struct pci_bus *bus = dev->bus;
3784 struct pci_dev *bridge;
3785 u32 cap, ctl2;
3786
3787 /*
3788 * Per PCIe r5.0, sec 9.3.5.10, the AtomicOp Requester Enable bit
3789 * in Device Control 2 is reserved in VFs and the PF value applies
3790 * to all associated VFs.
3791 */
3792 if (dev->is_virtfn)
3793 return -EINVAL;
3794
3795 if (!pci_is_pcie(dev))
3796 return -EINVAL;
3797
3798 /*
3799 * Per PCIe r4.0, sec 6.15, endpoints and root ports may be
3800 * AtomicOp requesters. For now, we only support endpoints as
3801 * requesters and root ports as completers. No endpoints as
3802 * completers, and no peer-to-peer.
3803 */
3804
3805 switch (pci_pcie_type(dev)) {
3806 case PCI_EXP_TYPE_ENDPOINT:
3807 case PCI_EXP_TYPE_LEG_END:
3808 case PCI_EXP_TYPE_RC_END:
3809 break;
3810 default:
3811 return -EINVAL;
3812 }
3813
3814 while (bus->parent) {
3815 bridge = bus->self;
3816
3817 pcie_capability_read_dword(bridge, PCI_EXP_DEVCAP2, &cap);
3818
3819 switch (pci_pcie_type(bridge)) {
3820 /* Ensure switch ports support AtomicOp routing */
3821 case PCI_EXP_TYPE_UPSTREAM:
3822 case PCI_EXP_TYPE_DOWNSTREAM:
3823 if (!(cap & PCI_EXP_DEVCAP2_ATOMIC_ROUTE))
3824 return -EINVAL;
3825 break;
3826
3827 /* Ensure root port supports all the sizes we care about */
3828 case PCI_EXP_TYPE_ROOT_PORT:
3829 if ((cap & cap_mask) != cap_mask)
3830 return -EINVAL;
3831 break;
3832 }
3833
3834 /* Ensure upstream ports don't block AtomicOps on egress */
3835 if (pci_pcie_type(bridge) == PCI_EXP_TYPE_UPSTREAM) {
3836 pcie_capability_read_dword(bridge, PCI_EXP_DEVCTL2,
3837 &ctl2);
3838 if (ctl2 & PCI_EXP_DEVCTL2_ATOMIC_EGRESS_BLOCK)
3839 return -EINVAL;
3840 }
3841
3842 bus = bus->parent;
3843 }
3844
3845 pcie_capability_set_word(dev, PCI_EXP_DEVCTL2,
3846 PCI_EXP_DEVCTL2_ATOMIC_REQ);
3847 return 0;
3848}
3849EXPORT_SYMBOL(pci_enable_atomic_ops_to_root);
3850
3851/**
3852 * pci_swizzle_interrupt_pin - swizzle INTx for device behind bridge
3853 * @dev: the PCI device
3854 * @pin: the INTx pin (1=INTA, 2=INTB, 3=INTC, 4=INTD)
3855 *
3856 * Perform INTx swizzling for a device behind one level of bridge. This is
3857 * required by section 9.1 of the PCI-to-PCI bridge specification for devices
3858 * behind bridges on add-in cards. For devices with ARI enabled, the slot
3859 * number is always 0 (see the Implementation Note in section 2.2.8.1 of
3860 * the PCI Express Base Specification, Revision 2.1)
3861 */
3862u8 pci_swizzle_interrupt_pin(const struct pci_dev *dev, u8 pin)
3863{
3864 int slot;
3865
3866 if (pci_ari_enabled(dev->bus))
3867 slot = 0;
3868 else
3869 slot = PCI_SLOT(dev->devfn);
3870
3871 return (((pin - 1) + slot) % 4) + 1;
3872}
3873
3874int pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge)
3875{
3876 u8 pin;
3877
3878 pin = dev->pin;
3879 if (!pin)
3880 return -1;
3881
3882 while (!pci_is_root_bus(dev->bus)) {
3883 pin = pci_swizzle_interrupt_pin(dev, pin);
3884 dev = dev->bus->self;
3885 }
3886 *bridge = dev;
3887 return pin;
3888}
3889
3890/**
3891 * pci_common_swizzle - swizzle INTx all the way to root bridge
3892 * @dev: the PCI device
3893 * @pinp: pointer to the INTx pin value (1=INTA, 2=INTB, 3=INTD, 4=INTD)
3894 *
3895 * Perform INTx swizzling for a device. This traverses through all PCI-to-PCI
3896 * bridges all the way up to a PCI root bus.
3897 */
3898u8 pci_common_swizzle(struct pci_dev *dev, u8 *pinp)
3899{
3900 u8 pin = *pinp;
3901
3902 while (!pci_is_root_bus(dev->bus)) {
3903 pin = pci_swizzle_interrupt_pin(dev, pin);
3904 dev = dev->bus->self;
3905 }
3906 *pinp = pin;
3907 return PCI_SLOT(dev->devfn);
3908}
3909EXPORT_SYMBOL_GPL(pci_common_swizzle);
3910
3911/**
3912 * pci_release_region - Release a PCI bar
3913 * @pdev: PCI device whose resources were previously reserved by
3914 * pci_request_region()
3915 * @bar: BAR to release
3916 *
3917 * Releases the PCI I/O and memory resources previously reserved by a
3918 * successful call to pci_request_region(). Call this function only
3919 * after all use of the PCI regions has ceased.
3920 */
3921void pci_release_region(struct pci_dev *pdev, int bar)
3922{
3923 struct pci_devres *dr;
3924
3925 if (pci_resource_len(pdev, bar) == 0)
3926 return;
3927 if (pci_resource_flags(pdev, bar) & IORESOURCE_IO)
3928 release_region(pci_resource_start(pdev, bar),
3929 pci_resource_len(pdev, bar));
3930 else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM)
3931 release_mem_region(pci_resource_start(pdev, bar),
3932 pci_resource_len(pdev, bar));
3933
3934 dr = find_pci_dr(pdev);
3935 if (dr)
3936 dr->region_mask &= ~(1 << bar);
3937}
3938EXPORT_SYMBOL(pci_release_region);
3939
3940/**
3941 * __pci_request_region - Reserved PCI I/O and memory resource
3942 * @pdev: PCI device whose resources are to be reserved
3943 * @bar: BAR to be reserved
3944 * @res_name: Name to be associated with resource.
3945 * @exclusive: whether the region access is exclusive or not
3946 *
3947 * Mark the PCI region associated with PCI device @pdev BAR @bar as
3948 * being reserved by owner @res_name. Do not access any
3949 * address inside the PCI regions unless this call returns
3950 * successfully.
3951 *
3952 * If @exclusive is set, then the region is marked so that userspace
3953 * is explicitly not allowed to map the resource via /dev/mem or
3954 * sysfs MMIO access.
3955 *
3956 * Returns 0 on success, or %EBUSY on error. A warning
3957 * message is also printed on failure.
3958 */
3959static int __pci_request_region(struct pci_dev *pdev, int bar,
3960 const char *res_name, int exclusive)
3961{
3962 struct pci_devres *dr;
3963
3964 if (pci_resource_len(pdev, bar) == 0)
3965 return 0;
3966
3967 if (pci_resource_flags(pdev, bar) & IORESOURCE_IO) {
3968 if (!request_region(pci_resource_start(pdev, bar),
3969 pci_resource_len(pdev, bar), res_name))
3970 goto err_out;
3971 } else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM) {
3972 if (!__request_mem_region(pci_resource_start(pdev, bar),
3973 pci_resource_len(pdev, bar), res_name,
3974 exclusive))
3975 goto err_out;
3976 }
3977
3978 dr = find_pci_dr(pdev);
3979 if (dr)
3980 dr->region_mask |= 1 << bar;
3981
3982 return 0;
3983
3984err_out:
3985 pci_warn(pdev, "BAR %d: can't reserve %pR\n", bar,
3986 &pdev->resource[bar]);
3987 return -EBUSY;
3988}
3989
3990/**
3991 * pci_request_region - Reserve PCI I/O and memory resource
3992 * @pdev: PCI device whose resources are to be reserved
3993 * @bar: BAR to be reserved
3994 * @res_name: Name to be associated with resource
3995 *
3996 * Mark the PCI region associated with PCI device @pdev BAR @bar as
3997 * being reserved by owner @res_name. Do not access any
3998 * address inside the PCI regions unless this call returns
3999 * successfully.
4000 *
4001 * Returns 0 on success, or %EBUSY on error. A warning
4002 * message is also printed on failure.
4003 */
4004int pci_request_region(struct pci_dev *pdev, int bar, const char *res_name)
4005{
4006 return __pci_request_region(pdev, bar, res_name, 0);
4007}
4008EXPORT_SYMBOL(pci_request_region);
4009
4010/**
4011 * pci_release_selected_regions - Release selected PCI I/O and memory resources
4012 * @pdev: PCI device whose resources were previously reserved
4013 * @bars: Bitmask of BARs to be released
4014 *
4015 * Release selected PCI I/O and memory resources previously reserved.
4016 * Call this function only after all use of the PCI regions has ceased.
4017 */
4018void pci_release_selected_regions(struct pci_dev *pdev, int bars)
4019{
4020 int i;
4021
4022 for (i = 0; i < PCI_STD_NUM_BARS; i++)
4023 if (bars & (1 << i))
4024 pci_release_region(pdev, i);
4025}
4026EXPORT_SYMBOL(pci_release_selected_regions);
4027
4028static int __pci_request_selected_regions(struct pci_dev *pdev, int bars,
4029 const char *res_name, int excl)
4030{
4031 int i;
4032
4033 for (i = 0; i < PCI_STD_NUM_BARS; i++)
4034 if (bars & (1 << i))
4035 if (__pci_request_region(pdev, i, res_name, excl))
4036 goto err_out;
4037 return 0;
4038
4039err_out:
4040 while (--i >= 0)
4041 if (bars & (1 << i))
4042 pci_release_region(pdev, i);
4043
4044 return -EBUSY;
4045}
4046
4047
4048/**
4049 * pci_request_selected_regions - Reserve selected PCI I/O and memory resources
4050 * @pdev: PCI device whose resources are to be reserved
4051 * @bars: Bitmask of BARs to be requested
4052 * @res_name: Name to be associated with resource
4053 */
4054int pci_request_selected_regions(struct pci_dev *pdev, int bars,
4055 const char *res_name)
4056{
4057 return __pci_request_selected_regions(pdev, bars, res_name, 0);
4058}
4059EXPORT_SYMBOL(pci_request_selected_regions);
4060
4061int pci_request_selected_regions_exclusive(struct pci_dev *pdev, int bars,
4062 const char *res_name)
4063{
4064 return __pci_request_selected_regions(pdev, bars, res_name,
4065 IORESOURCE_EXCLUSIVE);
4066}
4067EXPORT_SYMBOL(pci_request_selected_regions_exclusive);
4068
4069/**
4070 * pci_release_regions - Release reserved PCI I/O and memory resources
4071 * @pdev: PCI device whose resources were previously reserved by
4072 * pci_request_regions()
4073 *
4074 * Releases all PCI I/O and memory resources previously reserved by a
4075 * successful call to pci_request_regions(). Call this function only
4076 * after all use of the PCI regions has ceased.
4077 */
4078
4079void pci_release_regions(struct pci_dev *pdev)
4080{
4081 pci_release_selected_regions(pdev, (1 << PCI_STD_NUM_BARS) - 1);
4082}
4083EXPORT_SYMBOL(pci_release_regions);
4084
4085/**
4086 * pci_request_regions - Reserve PCI I/O and memory resources
4087 * @pdev: PCI device whose resources are to be reserved
4088 * @res_name: Name to be associated with resource.
4089 *
4090 * Mark all PCI regions associated with PCI device @pdev as
4091 * being reserved by owner @res_name. Do not access any
4092 * address inside the PCI regions unless this call returns
4093 * successfully.
4094 *
4095 * Returns 0 on success, or %EBUSY on error. A warning
4096 * message is also printed on failure.
4097 */
4098int pci_request_regions(struct pci_dev *pdev, const char *res_name)
4099{
4100 return pci_request_selected_regions(pdev,
4101 ((1 << PCI_STD_NUM_BARS) - 1), res_name);
4102}
4103EXPORT_SYMBOL(pci_request_regions);
4104
4105/**
4106 * pci_request_regions_exclusive - Reserve PCI I/O and memory resources
4107 * @pdev: PCI device whose resources are to be reserved
4108 * @res_name: Name to be associated with resource.
4109 *
4110 * Mark all PCI regions associated with PCI device @pdev as being reserved
4111 * by owner @res_name. Do not access any address inside the PCI regions
4112 * unless this call returns successfully.
4113 *
4114 * pci_request_regions_exclusive() will mark the region so that /dev/mem
4115 * and the sysfs MMIO access will not be allowed.
4116 *
4117 * Returns 0 on success, or %EBUSY on error. A warning message is also
4118 * printed on failure.
4119 */
4120int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name)
4121{
4122 return pci_request_selected_regions_exclusive(pdev,
4123 ((1 << PCI_STD_NUM_BARS) - 1), res_name);
4124}
4125EXPORT_SYMBOL(pci_request_regions_exclusive);
4126
4127/*
4128 * Record the PCI IO range (expressed as CPU physical address + size).
4129 * Return a negative value if an error has occurred, zero otherwise
4130 */
4131int pci_register_io_range(struct fwnode_handle *fwnode, phys_addr_t addr,
4132 resource_size_t size)
4133{
4134 int ret = 0;
4135#ifdef PCI_IOBASE
4136 struct logic_pio_hwaddr *range;
4137
4138 if (!size || addr + size < addr)
4139 return -EINVAL;
4140
4141 range = kzalloc(sizeof(*range), GFP_ATOMIC);
4142 if (!range)
4143 return -ENOMEM;
4144
4145 range->fwnode = fwnode;
4146 range->size = size;
4147 range->hw_start = addr;
4148 range->flags = LOGIC_PIO_CPU_MMIO;
4149
4150 ret = logic_pio_register_range(range);
4151 if (ret)
4152 kfree(range);
4153
4154 /* Ignore duplicates due to deferred probing */
4155 if (ret == -EEXIST)
4156 ret = 0;
4157#endif
4158
4159 return ret;
4160}
4161
4162phys_addr_t pci_pio_to_address(unsigned long pio)
4163{
4164 phys_addr_t address = (phys_addr_t)OF_BAD_ADDR;
4165
4166#ifdef PCI_IOBASE
4167 if (pio >= MMIO_UPPER_LIMIT)
4168 return address;
4169
4170 address = logic_pio_to_hwaddr(pio);
4171#endif
4172
4173 return address;
4174}
4175EXPORT_SYMBOL_GPL(pci_pio_to_address);
4176
4177unsigned long __weak pci_address_to_pio(phys_addr_t address)
4178{
4179#ifdef PCI_IOBASE
4180 return logic_pio_trans_cpuaddr(address);
4181#else
4182 if (address > IO_SPACE_LIMIT)
4183 return (unsigned long)-1;
4184
4185 return (unsigned long) address;
4186#endif
4187}
4188
4189/**
4190 * pci_remap_iospace - Remap the memory mapped I/O space
4191 * @res: Resource describing the I/O space
4192 * @phys_addr: physical address of range to be mapped
4193 *
4194 * Remap the memory mapped I/O space described by the @res and the CPU
4195 * physical address @phys_addr into virtual address space. Only
4196 * architectures that have memory mapped IO functions defined (and the
4197 * PCI_IOBASE value defined) should call this function.
4198 */
4199#ifndef pci_remap_iospace
4200int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr)
4201{
4202#if defined(PCI_IOBASE) && defined(CONFIG_MMU)
4203 unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start;
4204
4205 if (!(res->flags & IORESOURCE_IO))
4206 return -EINVAL;
4207
4208 if (res->end > IO_SPACE_LIMIT)
4209 return -EINVAL;
4210
4211 return ioremap_page_range(vaddr, vaddr + resource_size(res), phys_addr,
4212 pgprot_device(PAGE_KERNEL));
4213#else
4214 /*
4215 * This architecture does not have memory mapped I/O space,
4216 * so this function should never be called
4217 */
4218 WARN_ONCE(1, "This architecture does not support memory mapped I/O\n");
4219 return -ENODEV;
4220#endif
4221}
4222EXPORT_SYMBOL(pci_remap_iospace);
4223#endif
4224
4225/**
4226 * pci_unmap_iospace - Unmap the memory mapped I/O space
4227 * @res: resource to be unmapped
4228 *
4229 * Unmap the CPU virtual address @res from virtual address space. Only
4230 * architectures that have memory mapped IO functions defined (and the
4231 * PCI_IOBASE value defined) should call this function.
4232 */
4233void pci_unmap_iospace(struct resource *res)
4234{
4235#if defined(PCI_IOBASE) && defined(CONFIG_MMU)
4236 unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start;
4237
4238 vunmap_range(vaddr, vaddr + resource_size(res));
4239#endif
4240}
4241EXPORT_SYMBOL(pci_unmap_iospace);
4242
4243static void devm_pci_unmap_iospace(struct device *dev, void *ptr)
4244{
4245 struct resource **res = ptr;
4246
4247 pci_unmap_iospace(*res);
4248}
4249
4250/**
4251 * devm_pci_remap_iospace - Managed pci_remap_iospace()
4252 * @dev: Generic device to remap IO address for
4253 * @res: Resource describing the I/O space
4254 * @phys_addr: physical address of range to be mapped
4255 *
4256 * Managed pci_remap_iospace(). Map is automatically unmapped on driver
4257 * detach.
4258 */
4259int devm_pci_remap_iospace(struct device *dev, const struct resource *res,
4260 phys_addr_t phys_addr)
4261{
4262 const struct resource **ptr;
4263 int error;
4264
4265 ptr = devres_alloc(devm_pci_unmap_iospace, sizeof(*ptr), GFP_KERNEL);
4266 if (!ptr)
4267 return -ENOMEM;
4268
4269 error = pci_remap_iospace(res, phys_addr);
4270 if (error) {
4271 devres_free(ptr);
4272 } else {
4273 *ptr = res;
4274 devres_add(dev, ptr);
4275 }
4276
4277 return error;
4278}
4279EXPORT_SYMBOL(devm_pci_remap_iospace);
4280
4281/**
4282 * devm_pci_remap_cfgspace - Managed pci_remap_cfgspace()
4283 * @dev: Generic device to remap IO address for
4284 * @offset: Resource address to map
4285 * @size: Size of map
4286 *
4287 * Managed pci_remap_cfgspace(). Map is automatically unmapped on driver
4288 * detach.
4289 */
4290void __iomem *devm_pci_remap_cfgspace(struct device *dev,
4291 resource_size_t offset,
4292 resource_size_t size)
4293{
4294 void __iomem **ptr, *addr;
4295
4296 ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL);
4297 if (!ptr)
4298 return NULL;
4299
4300 addr = pci_remap_cfgspace(offset, size);
4301 if (addr) {
4302 *ptr = addr;
4303 devres_add(dev, ptr);
4304 } else
4305 devres_free(ptr);
4306
4307 return addr;
4308}
4309EXPORT_SYMBOL(devm_pci_remap_cfgspace);
4310
4311/**
4312 * devm_pci_remap_cfg_resource - check, request region and ioremap cfg resource
4313 * @dev: generic device to handle the resource for
4314 * @res: configuration space resource to be handled
4315 *
4316 * Checks that a resource is a valid memory region, requests the memory
4317 * region and ioremaps with pci_remap_cfgspace() API that ensures the
4318 * proper PCI configuration space memory attributes are guaranteed.
4319 *
4320 * All operations are managed and will be undone on driver detach.
4321 *
4322 * Returns a pointer to the remapped memory or an ERR_PTR() encoded error code
4323 * on failure. Usage example::
4324 *
4325 * res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
4326 * base = devm_pci_remap_cfg_resource(&pdev->dev, res);
4327 * if (IS_ERR(base))
4328 * return PTR_ERR(base);
4329 */
4330void __iomem *devm_pci_remap_cfg_resource(struct device *dev,
4331 struct resource *res)
4332{
4333 resource_size_t size;
4334 const char *name;
4335 void __iomem *dest_ptr;
4336
4337 BUG_ON(!dev);
4338
4339 if (!res || resource_type(res) != IORESOURCE_MEM) {
4340 dev_err(dev, "invalid resource\n");
4341 return IOMEM_ERR_PTR(-EINVAL);
4342 }
4343
4344 size = resource_size(res);
4345
4346 if (res->name)
4347 name = devm_kasprintf(dev, GFP_KERNEL, "%s %s", dev_name(dev),
4348 res->name);
4349 else
4350 name = devm_kstrdup(dev, dev_name(dev), GFP_KERNEL);
4351 if (!name)
4352 return IOMEM_ERR_PTR(-ENOMEM);
4353
4354 if (!devm_request_mem_region(dev, res->start, size, name)) {
4355 dev_err(dev, "can't request region for resource %pR\n", res);
4356 return IOMEM_ERR_PTR(-EBUSY);
4357 }
4358
4359 dest_ptr = devm_pci_remap_cfgspace(dev, res->start, size);
4360 if (!dest_ptr) {
4361 dev_err(dev, "ioremap failed for resource %pR\n", res);
4362 devm_release_mem_region(dev, res->start, size);
4363 dest_ptr = IOMEM_ERR_PTR(-ENOMEM);
4364 }
4365
4366 return dest_ptr;
4367}
4368EXPORT_SYMBOL(devm_pci_remap_cfg_resource);
4369
4370static void __pci_set_master(struct pci_dev *dev, bool enable)
4371{
4372 u16 old_cmd, cmd;
4373
4374 pci_read_config_word(dev, PCI_COMMAND, &old_cmd);
4375 if (enable)
4376 cmd = old_cmd | PCI_COMMAND_MASTER;
4377 else
4378 cmd = old_cmd & ~PCI_COMMAND_MASTER;
4379 if (cmd != old_cmd) {
4380 pci_dbg(dev, "%s bus mastering\n",
4381 enable ? "enabling" : "disabling");
4382 pci_write_config_word(dev, PCI_COMMAND, cmd);
4383 }
4384 dev->is_busmaster = enable;
4385}
4386
4387/**
4388 * pcibios_setup - process "pci=" kernel boot arguments
4389 * @str: string used to pass in "pci=" kernel boot arguments
4390 *
4391 * Process kernel boot arguments. This is the default implementation.
4392 * Architecture specific implementations can override this as necessary.
4393 */
4394char * __weak __init pcibios_setup(char *str)
4395{
4396 return str;
4397}
4398
4399/**
4400 * pcibios_set_master - enable PCI bus-mastering for device dev
4401 * @dev: the PCI device to enable
4402 *
4403 * Enables PCI bus-mastering for the device. This is the default
4404 * implementation. Architecture specific implementations can override
4405 * this if necessary.
4406 */
4407void __weak pcibios_set_master(struct pci_dev *dev)
4408{
4409 u8 lat;
4410
4411 /* The latency timer doesn't apply to PCIe (either Type 0 or Type 1) */
4412 if (pci_is_pcie(dev))
4413 return;
4414
4415 pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat);
4416 if (lat < 16)
4417 lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency;
4418 else if (lat > pcibios_max_latency)
4419 lat = pcibios_max_latency;
4420 else
4421 return;
4422
4423 pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat);
4424}
4425
4426/**
4427 * pci_set_master - enables bus-mastering for device dev
4428 * @dev: the PCI device to enable
4429 *
4430 * Enables bus-mastering on the device and calls pcibios_set_master()
4431 * to do the needed arch specific settings.
4432 */
4433void pci_set_master(struct pci_dev *dev)
4434{
4435 __pci_set_master(dev, true);
4436 pcibios_set_master(dev);
4437}
4438EXPORT_SYMBOL(pci_set_master);
4439
4440/**
4441 * pci_clear_master - disables bus-mastering for device dev
4442 * @dev: the PCI device to disable
4443 */
4444void pci_clear_master(struct pci_dev *dev)
4445{
4446 __pci_set_master(dev, false);
4447}
4448EXPORT_SYMBOL(pci_clear_master);
4449
4450/**
4451 * pci_set_cacheline_size - ensure the CACHE_LINE_SIZE register is programmed
4452 * @dev: the PCI device for which MWI is to be enabled
4453 *
4454 * Helper function for pci_set_mwi.
4455 * Originally copied from drivers/net/acenic.c.
4456 * Copyright 1998-2001 by Jes Sorensen, <jes@trained-monkey.org>.
4457 *
4458 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
4459 */
4460int pci_set_cacheline_size(struct pci_dev *dev)
4461{
4462 u8 cacheline_size;
4463
4464 if (!pci_cache_line_size)
4465 return -EINVAL;
4466
4467 /* Validate current setting: the PCI_CACHE_LINE_SIZE must be
4468 equal to or multiple of the right value. */
4469 pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
4470 if (cacheline_size >= pci_cache_line_size &&
4471 (cacheline_size % pci_cache_line_size) == 0)
4472 return 0;
4473
4474 /* Write the correct value. */
4475 pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, pci_cache_line_size);
4476 /* Read it back. */
4477 pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
4478 if (cacheline_size == pci_cache_line_size)
4479 return 0;
4480
4481 pci_dbg(dev, "cache line size of %d is not supported\n",
4482 pci_cache_line_size << 2);
4483
4484 return -EINVAL;
4485}
4486EXPORT_SYMBOL_GPL(pci_set_cacheline_size);
4487
4488/**
4489 * pci_set_mwi - enables memory-write-invalidate PCI transaction
4490 * @dev: the PCI device for which MWI is enabled
4491 *
4492 * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND.
4493 *
4494 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
4495 */
4496int pci_set_mwi(struct pci_dev *dev)
4497{
4498#ifdef PCI_DISABLE_MWI
4499 return 0;
4500#else
4501 int rc;
4502 u16 cmd;
4503
4504 rc = pci_set_cacheline_size(dev);
4505 if (rc)
4506 return rc;
4507
4508 pci_read_config_word(dev, PCI_COMMAND, &cmd);
4509 if (!(cmd & PCI_COMMAND_INVALIDATE)) {
4510 pci_dbg(dev, "enabling Mem-Wr-Inval\n");
4511 cmd |= PCI_COMMAND_INVALIDATE;
4512 pci_write_config_word(dev, PCI_COMMAND, cmd);
4513 }
4514 return 0;
4515#endif
4516}
4517EXPORT_SYMBOL(pci_set_mwi);
4518
4519/**
4520 * pcim_set_mwi - a device-managed pci_set_mwi()
4521 * @dev: the PCI device for which MWI is enabled
4522 *
4523 * Managed pci_set_mwi().
4524 *
4525 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
4526 */
4527int pcim_set_mwi(struct pci_dev *dev)
4528{
4529 struct pci_devres *dr;
4530
4531 dr = find_pci_dr(dev);
4532 if (!dr)
4533 return -ENOMEM;
4534
4535 dr->mwi = 1;
4536 return pci_set_mwi(dev);
4537}
4538EXPORT_SYMBOL(pcim_set_mwi);
4539
4540/**
4541 * pci_try_set_mwi - enables memory-write-invalidate PCI transaction
4542 * @dev: the PCI device for which MWI is enabled
4543 *
4544 * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND.
4545 * Callers are not required to check the return value.
4546 *
4547 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
4548 */
4549int pci_try_set_mwi(struct pci_dev *dev)
4550{
4551#ifdef PCI_DISABLE_MWI
4552 return 0;
4553#else
4554 return pci_set_mwi(dev);
4555#endif
4556}
4557EXPORT_SYMBOL(pci_try_set_mwi);
4558
4559/**
4560 * pci_clear_mwi - disables Memory-Write-Invalidate for device dev
4561 * @dev: the PCI device to disable
4562 *
4563 * Disables PCI Memory-Write-Invalidate transaction on the device
4564 */
4565void pci_clear_mwi(struct pci_dev *dev)
4566{
4567#ifndef PCI_DISABLE_MWI
4568 u16 cmd;
4569
4570 pci_read_config_word(dev, PCI_COMMAND, &cmd);
4571 if (cmd & PCI_COMMAND_INVALIDATE) {
4572 cmd &= ~PCI_COMMAND_INVALIDATE;
4573 pci_write_config_word(dev, PCI_COMMAND, cmd);
4574 }
4575#endif
4576}
4577EXPORT_SYMBOL(pci_clear_mwi);
4578
4579/**
4580 * pci_disable_parity - disable parity checking for device
4581 * @dev: the PCI device to operate on
4582 *
4583 * Disable parity checking for device @dev
4584 */
4585void pci_disable_parity(struct pci_dev *dev)
4586{
4587 u16 cmd;
4588
4589 pci_read_config_word(dev, PCI_COMMAND, &cmd);
4590 if (cmd & PCI_COMMAND_PARITY) {
4591 cmd &= ~PCI_COMMAND_PARITY;
4592 pci_write_config_word(dev, PCI_COMMAND, cmd);
4593 }
4594}
4595
4596/**
4597 * pci_intx - enables/disables PCI INTx for device dev
4598 * @pdev: the PCI device to operate on
4599 * @enable: boolean: whether to enable or disable PCI INTx
4600 *
4601 * Enables/disables PCI INTx for device @pdev
4602 */
4603void pci_intx(struct pci_dev *pdev, int enable)
4604{
4605 u16 pci_command, new;
4606
4607 pci_read_config_word(pdev, PCI_COMMAND, &pci_command);
4608
4609 if (enable)
4610 new = pci_command & ~PCI_COMMAND_INTX_DISABLE;
4611 else
4612 new = pci_command | PCI_COMMAND_INTX_DISABLE;
4613
4614 if (new != pci_command) {
4615 struct pci_devres *dr;
4616
4617 pci_write_config_word(pdev, PCI_COMMAND, new);
4618
4619 dr = find_pci_dr(pdev);
4620 if (dr && !dr->restore_intx) {
4621 dr->restore_intx = 1;
4622 dr->orig_intx = !enable;
4623 }
4624 }
4625}
4626EXPORT_SYMBOL_GPL(pci_intx);
4627
4628static bool pci_check_and_set_intx_mask(struct pci_dev *dev, bool mask)
4629{
4630 struct pci_bus *bus = dev->bus;
4631 bool mask_updated = true;
4632 u32 cmd_status_dword;
4633 u16 origcmd, newcmd;
4634 unsigned long flags;
4635 bool irq_pending;
4636
4637 /*
4638 * We do a single dword read to retrieve both command and status.
4639 * Document assumptions that make this possible.
4640 */
4641 BUILD_BUG_ON(PCI_COMMAND % 4);
4642 BUILD_BUG_ON(PCI_COMMAND + 2 != PCI_STATUS);
4643
4644 raw_spin_lock_irqsave(&pci_lock, flags);
4645
4646 bus->ops->read(bus, dev->devfn, PCI_COMMAND, 4, &cmd_status_dword);
4647
4648 irq_pending = (cmd_status_dword >> 16) & PCI_STATUS_INTERRUPT;
4649
4650 /*
4651 * Check interrupt status register to see whether our device
4652 * triggered the interrupt (when masking) or the next IRQ is
4653 * already pending (when unmasking).
4654 */
4655 if (mask != irq_pending) {
4656 mask_updated = false;
4657 goto done;
4658 }
4659
4660 origcmd = cmd_status_dword;
4661 newcmd = origcmd & ~PCI_COMMAND_INTX_DISABLE;
4662 if (mask)
4663 newcmd |= PCI_COMMAND_INTX_DISABLE;
4664 if (newcmd != origcmd)
4665 bus->ops->write(bus, dev->devfn, PCI_COMMAND, 2, newcmd);
4666
4667done:
4668 raw_spin_unlock_irqrestore(&pci_lock, flags);
4669
4670 return mask_updated;
4671}
4672
4673/**
4674 * pci_check_and_mask_intx - mask INTx on pending interrupt
4675 * @dev: the PCI device to operate on
4676 *
4677 * Check if the device dev has its INTx line asserted, mask it and return
4678 * true in that case. False is returned if no interrupt was pending.
4679 */
4680bool pci_check_and_mask_intx(struct pci_dev *dev)
4681{
4682 return pci_check_and_set_intx_mask(dev, true);
4683}
4684EXPORT_SYMBOL_GPL(pci_check_and_mask_intx);
4685
4686/**
4687 * pci_check_and_unmask_intx - unmask INTx if no interrupt is pending
4688 * @dev: the PCI device to operate on
4689 *
4690 * Check if the device dev has its INTx line asserted, unmask it if not and
4691 * return true. False is returned and the mask remains active if there was
4692 * still an interrupt pending.
4693 */
4694bool pci_check_and_unmask_intx(struct pci_dev *dev)
4695{
4696 return pci_check_and_set_intx_mask(dev, false);
4697}
4698EXPORT_SYMBOL_GPL(pci_check_and_unmask_intx);
4699
4700/**
4701 * pci_wait_for_pending_transaction - wait for pending transaction
4702 * @dev: the PCI device to operate on
4703 *
4704 * Return 0 if transaction is pending 1 otherwise.
4705 */
4706int pci_wait_for_pending_transaction(struct pci_dev *dev)
4707{
4708 if (!pci_is_pcie(dev))
4709 return 1;
4710
4711 return pci_wait_for_pending(dev, pci_pcie_cap(dev) + PCI_EXP_DEVSTA,
4712 PCI_EXP_DEVSTA_TRPND);
4713}
4714EXPORT_SYMBOL(pci_wait_for_pending_transaction);
4715
4716/**
4717 * pcie_flr - initiate a PCIe function level reset
4718 * @dev: device to reset
4719 *
4720 * Initiate a function level reset unconditionally on @dev without
4721 * checking any flags and DEVCAP
4722 */
4723int pcie_flr(struct pci_dev *dev)
4724{
4725 if (!pci_wait_for_pending_transaction(dev))
4726 pci_err(dev, "timed out waiting for pending transaction; performing function level reset anyway\n");
4727
4728 pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR);
4729
4730 if (dev->imm_ready)
4731 return 0;
4732
4733 /*
4734 * Per PCIe r4.0, sec 6.6.2, a device must complete an FLR within
4735 * 100ms, but may silently discard requests while the FLR is in
4736 * progress. Wait 100ms before trying to access the device.
4737 */
4738 msleep(100);
4739
4740 return pci_dev_wait(dev, "FLR", PCIE_RESET_READY_POLL_MS);
4741}
4742EXPORT_SYMBOL_GPL(pcie_flr);
4743
4744/**
4745 * pcie_reset_flr - initiate a PCIe function level reset
4746 * @dev: device to reset
4747 * @probe: if true, return 0 if device can be reset this way
4748 *
4749 * Initiate a function level reset on @dev.
4750 */
4751int pcie_reset_flr(struct pci_dev *dev, bool probe)
4752{
4753 if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
4754 return -ENOTTY;
4755
4756 if (!(dev->devcap & PCI_EXP_DEVCAP_FLR))
4757 return -ENOTTY;
4758
4759 if (probe)
4760 return 0;
4761
4762 return pcie_flr(dev);
4763}
4764EXPORT_SYMBOL_GPL(pcie_reset_flr);
4765
4766static int pci_af_flr(struct pci_dev *dev, bool probe)
4767{
4768 int pos;
4769 u8 cap;
4770
4771 pos = pci_find_capability(dev, PCI_CAP_ID_AF);
4772 if (!pos)
4773 return -ENOTTY;
4774
4775 if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
4776 return -ENOTTY;
4777
4778 pci_read_config_byte(dev, pos + PCI_AF_CAP, &cap);
4779 if (!(cap & PCI_AF_CAP_TP) || !(cap & PCI_AF_CAP_FLR))
4780 return -ENOTTY;
4781
4782 if (probe)
4783 return 0;
4784
4785 /*
4786 * Wait for Transaction Pending bit to clear. A word-aligned test
4787 * is used, so we use the control offset rather than status and shift
4788 * the test bit to match.
4789 */
4790 if (!pci_wait_for_pending(dev, pos + PCI_AF_CTRL,
4791 PCI_AF_STATUS_TP << 8))
4792 pci_err(dev, "timed out waiting for pending transaction; performing AF function level reset anyway\n");
4793
4794 pci_write_config_byte(dev, pos + PCI_AF_CTRL, PCI_AF_CTRL_FLR);
4795
4796 if (dev->imm_ready)
4797 return 0;
4798
4799 /*
4800 * Per Advanced Capabilities for Conventional PCI ECN, 13 April 2006,
4801 * updated 27 July 2006; a device must complete an FLR within
4802 * 100ms, but may silently discard requests while the FLR is in
4803 * progress. Wait 100ms before trying to access the device.
4804 */
4805 msleep(100);
4806
4807 return pci_dev_wait(dev, "AF_FLR", PCIE_RESET_READY_POLL_MS);
4808}
4809
4810/**
4811 * pci_pm_reset - Put device into PCI_D3 and back into PCI_D0.
4812 * @dev: Device to reset.
4813 * @probe: if true, return 0 if the device can be reset this way.
4814 *
4815 * If @dev supports native PCI PM and its PCI_PM_CTRL_NO_SOFT_RESET flag is
4816 * unset, it will be reinitialized internally when going from PCI_D3hot to
4817 * PCI_D0. If that's the case and the device is not in a low-power state
4818 * already, force it into PCI_D3hot and back to PCI_D0, causing it to be reset.
4819 *
4820 * NOTE: This causes the caller to sleep for twice the device power transition
4821 * cooldown period, which for the D0->D3hot and D3hot->D0 transitions is 10 ms
4822 * by default (i.e. unless the @dev's d3hot_delay field has a different value).
4823 * Moreover, only devices in D0 can be reset by this function.
4824 */
4825static int pci_pm_reset(struct pci_dev *dev, bool probe)
4826{
4827 u16 csr;
4828
4829 if (!dev->pm_cap || dev->dev_flags & PCI_DEV_FLAGS_NO_PM_RESET)
4830 return -ENOTTY;
4831
4832 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &csr);
4833 if (csr & PCI_PM_CTRL_NO_SOFT_RESET)
4834 return -ENOTTY;
4835
4836 if (probe)
4837 return 0;
4838
4839 if (dev->current_state != PCI_D0)
4840 return -EINVAL;
4841
4842 csr &= ~PCI_PM_CTRL_STATE_MASK;
4843 csr |= PCI_D3hot;
4844 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);
4845 pci_dev_d3_sleep(dev);
4846
4847 csr &= ~PCI_PM_CTRL_STATE_MASK;
4848 csr |= PCI_D0;
4849 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);
4850 pci_dev_d3_sleep(dev);
4851
4852 return pci_dev_wait(dev, "PM D3hot->D0", PCIE_RESET_READY_POLL_MS);
4853}
4854
4855/**
4856 * pcie_wait_for_link_delay - Wait until link is active or inactive
4857 * @pdev: Bridge device
4858 * @active: waiting for active or inactive?
4859 * @delay: Delay to wait after link has become active (in ms)
4860 *
4861 * Use this to wait till link becomes active or inactive.
4862 */
4863static bool pcie_wait_for_link_delay(struct pci_dev *pdev, bool active,
4864 int delay)
4865{
4866 int timeout = 1000;
4867 bool ret;
4868 u16 lnk_status;
4869
4870 /*
4871 * Some controllers might not implement link active reporting. In this
4872 * case, we wait for 1000 ms + any delay requested by the caller.
4873 */
4874 if (!pdev->link_active_reporting) {
4875 msleep(timeout + delay);
4876 return true;
4877 }
4878
4879 /*
4880 * PCIe r4.0 sec 6.6.1, a component must enter LTSSM Detect within 20ms,
4881 * after which we should expect an link active if the reset was
4882 * successful. If so, software must wait a minimum 100ms before sending
4883 * configuration requests to devices downstream this port.
4884 *
4885 * If the link fails to activate, either the device was physically
4886 * removed or the link is permanently failed.
4887 */
4888 if (active)
4889 msleep(20);
4890 for (;;) {
4891 pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
4892 ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA);
4893 if (ret == active)
4894 break;
4895 if (timeout <= 0)
4896 break;
4897 msleep(10);
4898 timeout -= 10;
4899 }
4900 if (active && ret)
4901 msleep(delay);
4902
4903 return ret == active;
4904}
4905
4906/**
4907 * pcie_wait_for_link - Wait until link is active or inactive
4908 * @pdev: Bridge device
4909 * @active: waiting for active or inactive?
4910 *
4911 * Use this to wait till link becomes active or inactive.
4912 */
4913bool pcie_wait_for_link(struct pci_dev *pdev, bool active)
4914{
4915 return pcie_wait_for_link_delay(pdev, active, 100);
4916}
4917
4918/*
4919 * Find maximum D3cold delay required by all the devices on the bus. The
4920 * spec says 100 ms, but firmware can lower it and we allow drivers to
4921 * increase it as well.
4922 *
4923 * Called with @pci_bus_sem locked for reading.
4924 */
4925static int pci_bus_max_d3cold_delay(const struct pci_bus *bus)
4926{
4927 const struct pci_dev *pdev;
4928 int min_delay = 100;
4929 int max_delay = 0;
4930
4931 list_for_each_entry(pdev, &bus->devices, bus_list) {
4932 if (pdev->d3cold_delay < min_delay)
4933 min_delay = pdev->d3cold_delay;
4934 if (pdev->d3cold_delay > max_delay)
4935 max_delay = pdev->d3cold_delay;
4936 }
4937
4938 return max(min_delay, max_delay);
4939}
4940
4941/**
4942 * pci_bridge_wait_for_secondary_bus - Wait for secondary bus to be accessible
4943 * @dev: PCI bridge
4944 *
4945 * Handle necessary delays before access to the devices on the secondary
4946 * side of the bridge are permitted after D3cold to D0 transition.
4947 *
4948 * For PCIe this means the delays in PCIe 5.0 section 6.6.1. For
4949 * conventional PCI it means Tpvrh + Trhfa specified in PCI 3.0 section
4950 * 4.3.2.
4951 */
4952void pci_bridge_wait_for_secondary_bus(struct pci_dev *dev)
4953{
4954 struct pci_dev *child;
4955 int delay;
4956
4957 if (pci_dev_is_disconnected(dev))
4958 return;
4959
4960 if (!pci_is_bridge(dev) || !dev->bridge_d3)
4961 return;
4962
4963 down_read(&pci_bus_sem);
4964
4965 /*
4966 * We only deal with devices that are present currently on the bus.
4967 * For any hot-added devices the access delay is handled in pciehp
4968 * board_added(). In case of ACPI hotplug the firmware is expected
4969 * to configure the devices before OS is notified.
4970 */
4971 if (!dev->subordinate || list_empty(&dev->subordinate->devices)) {
4972 up_read(&pci_bus_sem);
4973 return;
4974 }
4975
4976 /* Take d3cold_delay requirements into account */
4977 delay = pci_bus_max_d3cold_delay(dev->subordinate);
4978 if (!delay) {
4979 up_read(&pci_bus_sem);
4980 return;
4981 }
4982
4983 child = list_first_entry(&dev->subordinate->devices, struct pci_dev,
4984 bus_list);
4985 up_read(&pci_bus_sem);
4986
4987 /*
4988 * Conventional PCI and PCI-X we need to wait Tpvrh + Trhfa before
4989 * accessing the device after reset (that is 1000 ms + 100 ms). In
4990 * practice this should not be needed because we don't do power
4991 * management for them (see pci_bridge_d3_possible()).
4992 */
4993 if (!pci_is_pcie(dev)) {
4994 pci_dbg(dev, "waiting %d ms for secondary bus\n", 1000 + delay);
4995 msleep(1000 + delay);
4996 return;
4997 }
4998
4999 /*
5000 * For PCIe downstream and root ports that do not support speeds
5001 * greater than 5 GT/s need to wait minimum 100 ms. For higher
5002 * speeds (gen3) we need to wait first for the data link layer to
5003 * become active.
5004 *
5005 * However, 100 ms is the minimum and the PCIe spec says the
5006 * software must allow at least 1s before it can determine that the
5007 * device that did not respond is a broken device. There is
5008 * evidence that 100 ms is not always enough, for example certain
5009 * Titan Ridge xHCI controller does not always respond to
5010 * configuration requests if we only wait for 100 ms (see
5011 * https://bugzilla.kernel.org/show_bug.cgi?id=203885).
5012 *
5013 * Therefore we wait for 100 ms and check for the device presence.
5014 * If it is still not present give it an additional 100 ms.
5015 */
5016 if (!pcie_downstream_port(dev))
5017 return;
5018
5019 if (pcie_get_speed_cap(dev) <= PCIE_SPEED_5_0GT) {
5020 pci_dbg(dev, "waiting %d ms for downstream link\n", delay);
5021 msleep(delay);
5022 } else {
5023 pci_dbg(dev, "waiting %d ms for downstream link, after activation\n",
5024 delay);
5025 if (!pcie_wait_for_link_delay(dev, true, delay)) {
5026 /* Did not train, no need to wait any further */
5027 pci_info(dev, "Data Link Layer Link Active not set in 1000 msec\n");
5028 return;
5029 }
5030 }
5031
5032 if (!pci_device_is_present(child)) {
5033 pci_dbg(child, "waiting additional %d ms to become accessible\n", delay);
5034 msleep(delay);
5035 }
5036}
5037
5038void pci_reset_secondary_bus(struct pci_dev *dev)
5039{
5040 u16 ctrl;
5041
5042 pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &ctrl);
5043 ctrl |= PCI_BRIDGE_CTL_BUS_RESET;
5044 pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl);
5045
5046 /*
5047 * PCI spec v3.0 7.6.4.2 requires minimum Trst of 1ms. Double
5048 * this to 2ms to ensure that we meet the minimum requirement.
5049 */
5050 msleep(2);
5051
5052 ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET;
5053 pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl);
5054
5055 /*
5056 * Trhfa for conventional PCI is 2^25 clock cycles.
5057 * Assuming a minimum 33MHz clock this results in a 1s
5058 * delay before we can consider subordinate devices to
5059 * be re-initialized. PCIe has some ways to shorten this,
5060 * but we don't make use of them yet.
5061 */
5062 ssleep(1);
5063}
5064
5065void __weak pcibios_reset_secondary_bus(struct pci_dev *dev)
5066{
5067 pci_reset_secondary_bus(dev);
5068}
5069
5070/**
5071 * pci_bridge_secondary_bus_reset - Reset the secondary bus on a PCI bridge.
5072 * @dev: Bridge device
5073 *
5074 * Use the bridge control register to assert reset on the secondary bus.
5075 * Devices on the secondary bus are left in power-on state.
5076 */
5077int pci_bridge_secondary_bus_reset(struct pci_dev *dev)
5078{
5079 pcibios_reset_secondary_bus(dev);
5080
5081 return pci_dev_wait(dev, "bus reset", PCIE_RESET_READY_POLL_MS);
5082}
5083EXPORT_SYMBOL_GPL(pci_bridge_secondary_bus_reset);
5084
5085static int pci_parent_bus_reset(struct pci_dev *dev, bool probe)
5086{
5087 struct pci_dev *pdev;
5088
5089 if (pci_is_root_bus(dev->bus) || dev->subordinate ||
5090 !dev->bus->self || dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)
5091 return -ENOTTY;
5092
5093 list_for_each_entry(pdev, &dev->bus->devices, bus_list)
5094 if (pdev != dev)
5095 return -ENOTTY;
5096
5097 if (probe)
5098 return 0;
5099
5100 return pci_bridge_secondary_bus_reset(dev->bus->self);
5101}
5102
5103static int pci_reset_hotplug_slot(struct hotplug_slot *hotplug, bool probe)
5104{
5105 int rc = -ENOTTY;
5106
5107 if (!hotplug || !try_module_get(hotplug->owner))
5108 return rc;
5109
5110 if (hotplug->ops->reset_slot)
5111 rc = hotplug->ops->reset_slot(hotplug, probe);
5112
5113 module_put(hotplug->owner);
5114
5115 return rc;
5116}
5117
5118static int pci_dev_reset_slot_function(struct pci_dev *dev, bool probe)
5119{
5120 if (dev->multifunction || dev->subordinate || !dev->slot ||
5121 dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)
5122 return -ENOTTY;
5123
5124 return pci_reset_hotplug_slot(dev->slot->hotplug, probe);
5125}
5126
5127static int pci_reset_bus_function(struct pci_dev *dev, bool probe)
5128{
5129 int rc;
5130
5131 rc = pci_dev_reset_slot_function(dev, probe);
5132 if (rc != -ENOTTY)
5133 return rc;
5134 return pci_parent_bus_reset(dev, probe);
5135}
5136
5137void pci_dev_lock(struct pci_dev *dev)
5138{
5139 /* block PM suspend, driver probe, etc. */
5140 device_lock(&dev->dev);
5141 pci_cfg_access_lock(dev);
5142}
5143EXPORT_SYMBOL_GPL(pci_dev_lock);
5144
5145/* Return 1 on successful lock, 0 on contention */
5146int pci_dev_trylock(struct pci_dev *dev)
5147{
5148 if (device_trylock(&dev->dev)) {
5149 if (pci_cfg_access_trylock(dev))
5150 return 1;
5151 device_unlock(&dev->dev);
5152 }
5153
5154 return 0;
5155}
5156EXPORT_SYMBOL_GPL(pci_dev_trylock);
5157
5158void pci_dev_unlock(struct pci_dev *dev)
5159{
5160 pci_cfg_access_unlock(dev);
5161 device_unlock(&dev->dev);
5162}
5163EXPORT_SYMBOL_GPL(pci_dev_unlock);
5164
5165static void pci_dev_save_and_disable(struct pci_dev *dev)
5166{
5167 const struct pci_error_handlers *err_handler =
5168 dev->driver ? dev->driver->err_handler : NULL;
5169
5170 /*
5171 * dev->driver->err_handler->reset_prepare() is protected against
5172 * races with ->remove() by the device lock, which must be held by
5173 * the caller.
5174 */
5175 if (err_handler && err_handler->reset_prepare)
5176 err_handler->reset_prepare(dev);
5177
5178 /*
5179 * Wake-up device prior to save. PM registers default to D0 after
5180 * reset and a simple register restore doesn't reliably return
5181 * to a non-D0 state anyway.
5182 */
5183 pci_set_power_state(dev, PCI_D0);
5184
5185 pci_save_state(dev);
5186 /*
5187 * Disable the device by clearing the Command register, except for
5188 * INTx-disable which is set. This not only disables MMIO and I/O port
5189 * BARs, but also prevents the device from being Bus Master, preventing
5190 * DMA from the device including MSI/MSI-X interrupts. For PCI 2.3
5191 * compliant devices, INTx-disable prevents legacy interrupts.
5192 */
5193 pci_write_config_word(dev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
5194}
5195
5196static void pci_dev_restore(struct pci_dev *dev)
5197{
5198 const struct pci_error_handlers *err_handler =
5199 dev->driver ? dev->driver->err_handler : NULL;
5200
5201 pci_restore_state(dev);
5202
5203 /*
5204 * dev->driver->err_handler->reset_done() is protected against
5205 * races with ->remove() by the device lock, which must be held by
5206 * the caller.
5207 */
5208 if (err_handler && err_handler->reset_done)
5209 err_handler->reset_done(dev);
5210}
5211
5212/* dev->reset_methods[] is a 0-terminated list of indices into this array */
5213static const struct pci_reset_fn_method pci_reset_fn_methods[] = {
5214 { },
5215 { pci_dev_specific_reset, .name = "device_specific" },
5216 { pci_dev_acpi_reset, .name = "acpi" },
5217 { pcie_reset_flr, .name = "flr" },
5218 { pci_af_flr, .name = "af_flr" },
5219 { pci_pm_reset, .name = "pm" },
5220 { pci_reset_bus_function, .name = "bus" },
5221};
5222
5223static ssize_t reset_method_show(struct device *dev,
5224 struct device_attribute *attr, char *buf)
5225{
5226 struct pci_dev *pdev = to_pci_dev(dev);
5227 ssize_t len = 0;
5228 int i, m;
5229
5230 for (i = 0; i < PCI_NUM_RESET_METHODS; i++) {
5231 m = pdev->reset_methods[i];
5232 if (!m)
5233 break;
5234
5235 len += sysfs_emit_at(buf, len, "%s%s", len ? " " : "",
5236 pci_reset_fn_methods[m].name);
5237 }
5238
5239 if (len)
5240 len += sysfs_emit_at(buf, len, "\n");
5241
5242 return len;
5243}
5244
5245static int reset_method_lookup(const char *name)
5246{
5247 int m;
5248
5249 for (m = 1; m < PCI_NUM_RESET_METHODS; m++) {
5250 if (sysfs_streq(name, pci_reset_fn_methods[m].name))
5251 return m;
5252 }
5253
5254 return 0; /* not found */
5255}
5256
5257static ssize_t reset_method_store(struct device *dev,
5258 struct device_attribute *attr,
5259 const char *buf, size_t count)
5260{
5261 struct pci_dev *pdev = to_pci_dev(dev);
5262 char *options, *name;
5263 int m, n;
5264 u8 reset_methods[PCI_NUM_RESET_METHODS] = { 0 };
5265
5266 if (sysfs_streq(buf, "")) {
5267 pdev->reset_methods[0] = 0;
5268 pci_warn(pdev, "All device reset methods disabled by user");
5269 return count;
5270 }
5271
5272 if (sysfs_streq(buf, "default")) {
5273 pci_init_reset_methods(pdev);
5274 return count;
5275 }
5276
5277 options = kstrndup(buf, count, GFP_KERNEL);
5278 if (!options)
5279 return -ENOMEM;
5280
5281 n = 0;
5282 while ((name = strsep(&options, " ")) != NULL) {
5283 if (sysfs_streq(name, ""))
5284 continue;
5285
5286 name = strim(name);
5287
5288 m = reset_method_lookup(name);
5289 if (!m) {
5290 pci_err(pdev, "Invalid reset method '%s'", name);
5291 goto error;
5292 }
5293
5294 if (pci_reset_fn_methods[m].reset_fn(pdev, PCI_RESET_PROBE)) {
5295 pci_err(pdev, "Unsupported reset method '%s'", name);
5296 goto error;
5297 }
5298
5299 if (n == PCI_NUM_RESET_METHODS - 1) {
5300 pci_err(pdev, "Too many reset methods\n");
5301 goto error;
5302 }
5303
5304 reset_methods[n++] = m;
5305 }
5306
5307 reset_methods[n] = 0;
5308
5309 /* Warn if dev-specific supported but not highest priority */
5310 if (pci_reset_fn_methods[1].reset_fn(pdev, PCI_RESET_PROBE) == 0 &&
5311 reset_methods[0] != 1)
5312 pci_warn(pdev, "Device-specific reset disabled/de-prioritized by user");
5313 memcpy(pdev->reset_methods, reset_methods, sizeof(pdev->reset_methods));
5314 kfree(options);
5315 return count;
5316
5317error:
5318 /* Leave previous methods unchanged */
5319 kfree(options);
5320 return -EINVAL;
5321}
5322static DEVICE_ATTR_RW(reset_method);
5323
5324static struct attribute *pci_dev_reset_method_attrs[] = {
5325 &dev_attr_reset_method.attr,
5326 NULL,
5327};
5328
5329static umode_t pci_dev_reset_method_attr_is_visible(struct kobject *kobj,
5330 struct attribute *a, int n)
5331{
5332 struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
5333
5334 if (!pci_reset_supported(pdev))
5335 return 0;
5336
5337 return a->mode;
5338}
5339
5340const struct attribute_group pci_dev_reset_method_attr_group = {
5341 .attrs = pci_dev_reset_method_attrs,
5342 .is_visible = pci_dev_reset_method_attr_is_visible,
5343};
5344
5345/**
5346 * __pci_reset_function_locked - reset a PCI device function while holding
5347 * the @dev mutex lock.
5348 * @dev: PCI device to reset
5349 *
5350 * Some devices allow an individual function to be reset without affecting
5351 * other functions in the same device. The PCI device must be responsive
5352 * to PCI config space in order to use this function.
5353 *
5354 * The device function is presumed to be unused and the caller is holding
5355 * the device mutex lock when this function is called.
5356 *
5357 * Resetting the device will make the contents of PCI configuration space
5358 * random, so any caller of this must be prepared to reinitialise the
5359 * device including MSI, bus mastering, BARs, decoding IO and memory spaces,
5360 * etc.
5361 *
5362 * Returns 0 if the device function was successfully reset or negative if the
5363 * device doesn't support resetting a single function.
5364 */
5365int __pci_reset_function_locked(struct pci_dev *dev)
5366{
5367 int i, m, rc;
5368
5369 might_sleep();
5370
5371 /*
5372 * A reset method returns -ENOTTY if it doesn't support this device and
5373 * we should try the next method.
5374 *
5375 * If it returns 0 (success), we're finished. If it returns any other
5376 * error, we're also finished: this indicates that further reset
5377 * mechanisms might be broken on the device.
5378 */
5379 for (i = 0; i < PCI_NUM_RESET_METHODS; i++) {
5380 m = dev->reset_methods[i];
5381 if (!m)
5382 return -ENOTTY;
5383
5384 rc = pci_reset_fn_methods[m].reset_fn(dev, PCI_RESET_DO_RESET);
5385 if (!rc)
5386 return 0;
5387 if (rc != -ENOTTY)
5388 return rc;
5389 }
5390
5391 return -ENOTTY;
5392}
5393EXPORT_SYMBOL_GPL(__pci_reset_function_locked);
5394
5395/**
5396 * pci_init_reset_methods - check whether device can be safely reset
5397 * and store supported reset mechanisms.
5398 * @dev: PCI device to check for reset mechanisms
5399 *
5400 * Some devices allow an individual function to be reset without affecting
5401 * other functions in the same device. The PCI device must be in D0-D3hot
5402 * state.
5403 *
5404 * Stores reset mechanisms supported by device in reset_methods byte array
5405 * which is a member of struct pci_dev.
5406 */
5407void pci_init_reset_methods(struct pci_dev *dev)
5408{
5409 int m, i, rc;
5410
5411 BUILD_BUG_ON(ARRAY_SIZE(pci_reset_fn_methods) != PCI_NUM_RESET_METHODS);
5412
5413 might_sleep();
5414
5415 i = 0;
5416 for (m = 1; m < PCI_NUM_RESET_METHODS; m++) {
5417 rc = pci_reset_fn_methods[m].reset_fn(dev, PCI_RESET_PROBE);
5418 if (!rc)
5419 dev->reset_methods[i++] = m;
5420 else if (rc != -ENOTTY)
5421 break;
5422 }
5423
5424 dev->reset_methods[i] = 0;
5425}
5426
5427/**
5428 * pci_reset_function - quiesce and reset a PCI device function
5429 * @dev: PCI device to reset
5430 *
5431 * Some devices allow an individual function to be reset without affecting
5432 * other functions in the same device. The PCI device must be responsive
5433 * to PCI config space in order to use this function.
5434 *
5435 * This function does not just reset the PCI portion of a device, but
5436 * clears all the state associated with the device. This function differs
5437 * from __pci_reset_function_locked() in that it saves and restores device state
5438 * over the reset and takes the PCI device lock.
5439 *
5440 * Returns 0 if the device function was successfully reset or negative if the
5441 * device doesn't support resetting a single function.
5442 */
5443int pci_reset_function(struct pci_dev *dev)
5444{
5445 int rc;
5446
5447 if (!pci_reset_supported(dev))
5448 return -ENOTTY;
5449
5450 pci_dev_lock(dev);
5451 pci_dev_save_and_disable(dev);
5452
5453 rc = __pci_reset_function_locked(dev);
5454
5455 pci_dev_restore(dev);
5456 pci_dev_unlock(dev);
5457
5458 return rc;
5459}
5460EXPORT_SYMBOL_GPL(pci_reset_function);
5461
5462/**
5463 * pci_reset_function_locked - quiesce and reset a PCI device function
5464 * @dev: PCI device to reset
5465 *
5466 * Some devices allow an individual function to be reset without affecting
5467 * other functions in the same device. The PCI device must be responsive
5468 * to PCI config space in order to use this function.
5469 *
5470 * This function does not just reset the PCI portion of a device, but
5471 * clears all the state associated with the device. This function differs
5472 * from __pci_reset_function_locked() in that it saves and restores device state
5473 * over the reset. It also differs from pci_reset_function() in that it
5474 * requires the PCI device lock to be held.
5475 *
5476 * Returns 0 if the device function was successfully reset or negative if the
5477 * device doesn't support resetting a single function.
5478 */
5479int pci_reset_function_locked(struct pci_dev *dev)
5480{
5481 int rc;
5482
5483 if (!pci_reset_supported(dev))
5484 return -ENOTTY;
5485
5486 pci_dev_save_and_disable(dev);
5487
5488 rc = __pci_reset_function_locked(dev);
5489
5490 pci_dev_restore(dev);
5491
5492 return rc;
5493}
5494EXPORT_SYMBOL_GPL(pci_reset_function_locked);
5495
5496/**
5497 * pci_try_reset_function - quiesce and reset a PCI device function
5498 * @dev: PCI device to reset
5499 *
5500 * Same as above, except return -EAGAIN if unable to lock device.
5501 */
5502int pci_try_reset_function(struct pci_dev *dev)
5503{
5504 int rc;
5505
5506 if (!pci_reset_supported(dev))
5507 return -ENOTTY;
5508
5509 if (!pci_dev_trylock(dev))
5510 return -EAGAIN;
5511
5512 pci_dev_save_and_disable(dev);
5513 rc = __pci_reset_function_locked(dev);
5514 pci_dev_restore(dev);
5515 pci_dev_unlock(dev);
5516
5517 return rc;
5518}
5519EXPORT_SYMBOL_GPL(pci_try_reset_function);
5520
5521/* Do any devices on or below this bus prevent a bus reset? */
5522static bool pci_bus_resetable(struct pci_bus *bus)
5523{
5524 struct pci_dev *dev;
5525
5526
5527 if (bus->self && (bus->self->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET))
5528 return false;
5529
5530 list_for_each_entry(dev, &bus->devices, bus_list) {
5531 if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET ||
5532 (dev->subordinate && !pci_bus_resetable(dev->subordinate)))
5533 return false;
5534 }
5535
5536 return true;
5537}
5538
5539/* Lock devices from the top of the tree down */
5540static void pci_bus_lock(struct pci_bus *bus)
5541{
5542 struct pci_dev *dev;
5543
5544 list_for_each_entry(dev, &bus->devices, bus_list) {
5545 pci_dev_lock(dev);
5546 if (dev->subordinate)
5547 pci_bus_lock(dev->subordinate);
5548 }
5549}
5550
5551/* Unlock devices from the bottom of the tree up */
5552static void pci_bus_unlock(struct pci_bus *bus)
5553{
5554 struct pci_dev *dev;
5555
5556 list_for_each_entry(dev, &bus->devices, bus_list) {
5557 if (dev->subordinate)
5558 pci_bus_unlock(dev->subordinate);
5559 pci_dev_unlock(dev);
5560 }
5561}
5562
5563/* Return 1 on successful lock, 0 on contention */
5564static int pci_bus_trylock(struct pci_bus *bus)
5565{
5566 struct pci_dev *dev;
5567
5568 list_for_each_entry(dev, &bus->devices, bus_list) {
5569 if (!pci_dev_trylock(dev))
5570 goto unlock;
5571 if (dev->subordinate) {
5572 if (!pci_bus_trylock(dev->subordinate)) {
5573 pci_dev_unlock(dev);
5574 goto unlock;
5575 }
5576 }
5577 }
5578 return 1;
5579
5580unlock:
5581 list_for_each_entry_continue_reverse(dev, &bus->devices, bus_list) {
5582 if (dev->subordinate)
5583 pci_bus_unlock(dev->subordinate);
5584 pci_dev_unlock(dev);
5585 }
5586 return 0;
5587}
5588
5589/* Do any devices on or below this slot prevent a bus reset? */
5590static bool pci_slot_resetable(struct pci_slot *slot)
5591{
5592 struct pci_dev *dev;
5593
5594 if (slot->bus->self &&
5595 (slot->bus->self->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET))
5596 return false;
5597
5598 list_for_each_entry(dev, &slot->bus->devices, bus_list) {
5599 if (!dev->slot || dev->slot != slot)
5600 continue;
5601 if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET ||
5602 (dev->subordinate && !pci_bus_resetable(dev->subordinate)))
5603 return false;
5604 }
5605
5606 return true;
5607}
5608
5609/* Lock devices from the top of the tree down */
5610static void pci_slot_lock(struct pci_slot *slot)
5611{
5612 struct pci_dev *dev;
5613
5614 list_for_each_entry(dev, &slot->bus->devices, bus_list) {
5615 if (!dev->slot || dev->slot != slot)
5616 continue;
5617 pci_dev_lock(dev);
5618 if (dev->subordinate)
5619 pci_bus_lock(dev->subordinate);
5620 }
5621}
5622
5623/* Unlock devices from the bottom of the tree up */
5624static void pci_slot_unlock(struct pci_slot *slot)
5625{
5626 struct pci_dev *dev;
5627
5628 list_for_each_entry(dev, &slot->bus->devices, bus_list) {
5629 if (!dev->slot || dev->slot != slot)
5630 continue;
5631 if (dev->subordinate)
5632 pci_bus_unlock(dev->subordinate);
5633 pci_dev_unlock(dev);
5634 }
5635}
5636
5637/* Return 1 on successful lock, 0 on contention */
5638static int pci_slot_trylock(struct pci_slot *slot)
5639{
5640 struct pci_dev *dev;
5641
5642 list_for_each_entry(dev, &slot->bus->devices, bus_list) {
5643 if (!dev->slot || dev->slot != slot)
5644 continue;
5645 if (!pci_dev_trylock(dev))
5646 goto unlock;
5647 if (dev->subordinate) {
5648 if (!pci_bus_trylock(dev->subordinate)) {
5649 pci_dev_unlock(dev);
5650 goto unlock;
5651 }
5652 }
5653 }
5654 return 1;
5655
5656unlock:
5657 list_for_each_entry_continue_reverse(dev,
5658 &slot->bus->devices, bus_list) {
5659 if (!dev->slot || dev->slot != slot)
5660 continue;
5661 if (dev->subordinate)
5662 pci_bus_unlock(dev->subordinate);
5663 pci_dev_unlock(dev);
5664 }
5665 return 0;
5666}
5667
5668/*
5669 * Save and disable devices from the top of the tree down while holding
5670 * the @dev mutex lock for the entire tree.
5671 */
5672static void pci_bus_save_and_disable_locked(struct pci_bus *bus)
5673{
5674 struct pci_dev *dev;
5675
5676 list_for_each_entry(dev, &bus->devices, bus_list) {
5677 pci_dev_save_and_disable(dev);
5678 if (dev->subordinate)
5679 pci_bus_save_and_disable_locked(dev->subordinate);
5680 }
5681}
5682
5683/*
5684 * Restore devices from top of the tree down while holding @dev mutex lock
5685 * for the entire tree. Parent bridges need to be restored before we can
5686 * get to subordinate devices.
5687 */
5688static void pci_bus_restore_locked(struct pci_bus *bus)
5689{
5690 struct pci_dev *dev;
5691
5692 list_for_each_entry(dev, &bus->devices, bus_list) {
5693 pci_dev_restore(dev);
5694 if (dev->subordinate)
5695 pci_bus_restore_locked(dev->subordinate);
5696 }
5697}
5698
5699/*
5700 * Save and disable devices from the top of the tree down while holding
5701 * the @dev mutex lock for the entire tree.
5702 */
5703static void pci_slot_save_and_disable_locked(struct pci_slot *slot)
5704{
5705 struct pci_dev *dev;
5706
5707 list_for_each_entry(dev, &slot->bus->devices, bus_list) {
5708 if (!dev->slot || dev->slot != slot)
5709 continue;
5710 pci_dev_save_and_disable(dev);
5711 if (dev->subordinate)
5712 pci_bus_save_and_disable_locked(dev->subordinate);
5713 }
5714}
5715
5716/*
5717 * Restore devices from top of the tree down while holding @dev mutex lock
5718 * for the entire tree. Parent bridges need to be restored before we can
5719 * get to subordinate devices.
5720 */
5721static void pci_slot_restore_locked(struct pci_slot *slot)
5722{
5723 struct pci_dev *dev;
5724
5725 list_for_each_entry(dev, &slot->bus->devices, bus_list) {
5726 if (!dev->slot || dev->slot != slot)
5727 continue;
5728 pci_dev_restore(dev);
5729 if (dev->subordinate)
5730 pci_bus_restore_locked(dev->subordinate);
5731 }
5732}
5733
5734static int pci_slot_reset(struct pci_slot *slot, bool probe)
5735{
5736 int rc;
5737
5738 if (!slot || !pci_slot_resetable(slot))
5739 return -ENOTTY;
5740
5741 if (!probe)
5742 pci_slot_lock(slot);
5743
5744 might_sleep();
5745
5746 rc = pci_reset_hotplug_slot(slot->hotplug, probe);
5747
5748 if (!probe)
5749 pci_slot_unlock(slot);
5750
5751 return rc;
5752}
5753
5754/**
5755 * pci_probe_reset_slot - probe whether a PCI slot can be reset
5756 * @slot: PCI slot to probe
5757 *
5758 * Return 0 if slot can be reset, negative if a slot reset is not supported.
5759 */
5760int pci_probe_reset_slot(struct pci_slot *slot)
5761{
5762 return pci_slot_reset(slot, PCI_RESET_PROBE);
5763}
5764EXPORT_SYMBOL_GPL(pci_probe_reset_slot);
5765
5766/**
5767 * __pci_reset_slot - Try to reset a PCI slot
5768 * @slot: PCI slot to reset
5769 *
5770 * A PCI bus may host multiple slots, each slot may support a reset mechanism
5771 * independent of other slots. For instance, some slots may support slot power
5772 * control. In the case of a 1:1 bus to slot architecture, this function may
5773 * wrap the bus reset to avoid spurious slot related events such as hotplug.
5774 * Generally a slot reset should be attempted before a bus reset. All of the
5775 * function of the slot and any subordinate buses behind the slot are reset
5776 * through this function. PCI config space of all devices in the slot and
5777 * behind the slot is saved before and restored after reset.
5778 *
5779 * Same as above except return -EAGAIN if the slot cannot be locked
5780 */
5781static int __pci_reset_slot(struct pci_slot *slot)
5782{
5783 int rc;
5784
5785 rc = pci_slot_reset(slot, PCI_RESET_PROBE);
5786 if (rc)
5787 return rc;
5788
5789 if (pci_slot_trylock(slot)) {
5790 pci_slot_save_and_disable_locked(slot);
5791 might_sleep();
5792 rc = pci_reset_hotplug_slot(slot->hotplug, PCI_RESET_DO_RESET);
5793 pci_slot_restore_locked(slot);
5794 pci_slot_unlock(slot);
5795 } else
5796 rc = -EAGAIN;
5797
5798 return rc;
5799}
5800
5801static int pci_bus_reset(struct pci_bus *bus, bool probe)
5802{
5803 int ret;
5804
5805 if (!bus->self || !pci_bus_resetable(bus))
5806 return -ENOTTY;
5807
5808 if (probe)
5809 return 0;
5810
5811 pci_bus_lock(bus);
5812
5813 might_sleep();
5814
5815 ret = pci_bridge_secondary_bus_reset(bus->self);
5816
5817 pci_bus_unlock(bus);
5818
5819 return ret;
5820}
5821
5822/**
5823 * pci_bus_error_reset - reset the bridge's subordinate bus
5824 * @bridge: The parent device that connects to the bus to reset
5825 *
5826 * This function will first try to reset the slots on this bus if the method is
5827 * available. If slot reset fails or is not available, this will fall back to a
5828 * secondary bus reset.
5829 */
5830int pci_bus_error_reset(struct pci_dev *bridge)
5831{
5832 struct pci_bus *bus = bridge->subordinate;
5833 struct pci_slot *slot;
5834
5835 if (!bus)
5836 return -ENOTTY;
5837
5838 mutex_lock(&pci_slot_mutex);
5839 if (list_empty(&bus->slots))
5840 goto bus_reset;
5841
5842 list_for_each_entry(slot, &bus->slots, list)
5843 if (pci_probe_reset_slot(slot))
5844 goto bus_reset;
5845
5846 list_for_each_entry(slot, &bus->slots, list)
5847 if (pci_slot_reset(slot, PCI_RESET_DO_RESET))
5848 goto bus_reset;
5849
5850 mutex_unlock(&pci_slot_mutex);
5851 return 0;
5852bus_reset:
5853 mutex_unlock(&pci_slot_mutex);
5854 return pci_bus_reset(bridge->subordinate, PCI_RESET_DO_RESET);
5855}
5856
5857/**
5858 * pci_probe_reset_bus - probe whether a PCI bus can be reset
5859 * @bus: PCI bus to probe
5860 *
5861 * Return 0 if bus can be reset, negative if a bus reset is not supported.
5862 */
5863int pci_probe_reset_bus(struct pci_bus *bus)
5864{
5865 return pci_bus_reset(bus, PCI_RESET_PROBE);
5866}
5867EXPORT_SYMBOL_GPL(pci_probe_reset_bus);
5868
5869/**
5870 * __pci_reset_bus - Try to reset a PCI bus
5871 * @bus: top level PCI bus to reset
5872 *
5873 * Same as above except return -EAGAIN if the bus cannot be locked
5874 */
5875static int __pci_reset_bus(struct pci_bus *bus)
5876{
5877 int rc;
5878
5879 rc = pci_bus_reset(bus, PCI_RESET_PROBE);
5880 if (rc)
5881 return rc;
5882
5883 if (pci_bus_trylock(bus)) {
5884 pci_bus_save_and_disable_locked(bus);
5885 might_sleep();
5886 rc = pci_bridge_secondary_bus_reset(bus->self);
5887 pci_bus_restore_locked(bus);
5888 pci_bus_unlock(bus);
5889 } else
5890 rc = -EAGAIN;
5891
5892 return rc;
5893}
5894
5895/**
5896 * pci_reset_bus - Try to reset a PCI bus
5897 * @pdev: top level PCI device to reset via slot/bus
5898 *
5899 * Same as above except return -EAGAIN if the bus cannot be locked
5900 */
5901int pci_reset_bus(struct pci_dev *pdev)
5902{
5903 return (!pci_probe_reset_slot(pdev->slot)) ?
5904 __pci_reset_slot(pdev->slot) : __pci_reset_bus(pdev->bus);
5905}
5906EXPORT_SYMBOL_GPL(pci_reset_bus);
5907
5908/**
5909 * pcix_get_max_mmrbc - get PCI-X maximum designed memory read byte count
5910 * @dev: PCI device to query
5911 *
5912 * Returns mmrbc: maximum designed memory read count in bytes or
5913 * appropriate error value.
5914 */
5915int pcix_get_max_mmrbc(struct pci_dev *dev)
5916{
5917 int cap;
5918 u32 stat;
5919
5920 cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
5921 if (!cap)
5922 return -EINVAL;
5923
5924 if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat))
5925 return -EINVAL;
5926
5927 return 512 << ((stat & PCI_X_STATUS_MAX_READ) >> 21);
5928}
5929EXPORT_SYMBOL(pcix_get_max_mmrbc);
5930
5931/**
5932 * pcix_get_mmrbc - get PCI-X maximum memory read byte count
5933 * @dev: PCI device to query
5934 *
5935 * Returns mmrbc: maximum memory read count in bytes or appropriate error
5936 * value.
5937 */
5938int pcix_get_mmrbc(struct pci_dev *dev)
5939{
5940 int cap;
5941 u16 cmd;
5942
5943 cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
5944 if (!cap)
5945 return -EINVAL;
5946
5947 if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd))
5948 return -EINVAL;
5949
5950 return 512 << ((cmd & PCI_X_CMD_MAX_READ) >> 2);
5951}
5952EXPORT_SYMBOL(pcix_get_mmrbc);
5953
5954/**
5955 * pcix_set_mmrbc - set PCI-X maximum memory read byte count
5956 * @dev: PCI device to query
5957 * @mmrbc: maximum memory read count in bytes
5958 * valid values are 512, 1024, 2048, 4096
5959 *
5960 * If possible sets maximum memory read byte count, some bridges have errata
5961 * that prevent this.
5962 */
5963int pcix_set_mmrbc(struct pci_dev *dev, int mmrbc)
5964{
5965 int cap;
5966 u32 stat, v, o;
5967 u16 cmd;
5968
5969 if (mmrbc < 512 || mmrbc > 4096 || !is_power_of_2(mmrbc))
5970 return -EINVAL;
5971
5972 v = ffs(mmrbc) - 10;
5973
5974 cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
5975 if (!cap)
5976 return -EINVAL;
5977
5978 if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat))
5979 return -EINVAL;
5980
5981 if (v > (stat & PCI_X_STATUS_MAX_READ) >> 21)
5982 return -E2BIG;
5983
5984 if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd))
5985 return -EINVAL;
5986
5987 o = (cmd & PCI_X_CMD_MAX_READ) >> 2;
5988 if (o != v) {
5989 if (v > o && (dev->bus->bus_flags & PCI_BUS_FLAGS_NO_MMRBC))
5990 return -EIO;
5991
5992 cmd &= ~PCI_X_CMD_MAX_READ;
5993 cmd |= v << 2;
5994 if (pci_write_config_word(dev, cap + PCI_X_CMD, cmd))
5995 return -EIO;
5996 }
5997 return 0;
5998}
5999EXPORT_SYMBOL(pcix_set_mmrbc);
6000
6001/**
6002 * pcie_get_readrq - get PCI Express read request size
6003 * @dev: PCI device to query
6004 *
6005 * Returns maximum memory read request in bytes or appropriate error value.
6006 */
6007int pcie_get_readrq(struct pci_dev *dev)
6008{
6009 u16 ctl;
6010
6011 pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl);
6012
6013 return 128 << ((ctl & PCI_EXP_DEVCTL_READRQ) >> 12);
6014}
6015EXPORT_SYMBOL(pcie_get_readrq);
6016
6017/**
6018 * pcie_set_readrq - set PCI Express maximum memory read request
6019 * @dev: PCI device to query
6020 * @rq: maximum memory read count in bytes
6021 * valid values are 128, 256, 512, 1024, 2048, 4096
6022 *
6023 * If possible sets maximum memory read request in bytes
6024 */
6025int pcie_set_readrq(struct pci_dev *dev, int rq)
6026{
6027 u16 v;
6028 int ret;
6029
6030 if (rq < 128 || rq > 4096 || !is_power_of_2(rq))
6031 return -EINVAL;
6032
6033 /*
6034 * If using the "performance" PCIe config, we clamp the read rq
6035 * size to the max packet size to keep the host bridge from
6036 * generating requests larger than we can cope with.
6037 */
6038 if (pcie_bus_config == PCIE_BUS_PERFORMANCE) {
6039 int mps = pcie_get_mps(dev);
6040
6041 if (mps < rq)
6042 rq = mps;
6043 }
6044
6045 v = (ffs(rq) - 8) << 12;
6046
6047 ret = pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
6048 PCI_EXP_DEVCTL_READRQ, v);
6049
6050 return pcibios_err_to_errno(ret);
6051}
6052EXPORT_SYMBOL(pcie_set_readrq);
6053
6054/**
6055 * pcie_get_mps - get PCI Express maximum payload size
6056 * @dev: PCI device to query
6057 *
6058 * Returns maximum payload size in bytes
6059 */
6060int pcie_get_mps(struct pci_dev *dev)
6061{
6062 u16 ctl;
6063
6064 pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl);
6065
6066 return 128 << ((ctl & PCI_EXP_DEVCTL_PAYLOAD) >> 5);
6067}
6068EXPORT_SYMBOL(pcie_get_mps);
6069
6070/**
6071 * pcie_set_mps - set PCI Express maximum payload size
6072 * @dev: PCI device to query
6073 * @mps: maximum payload size in bytes
6074 * valid values are 128, 256, 512, 1024, 2048, 4096
6075 *
6076 * If possible sets maximum payload size
6077 */
6078int pcie_set_mps(struct pci_dev *dev, int mps)
6079{
6080 u16 v;
6081 int ret;
6082
6083 if (mps < 128 || mps > 4096 || !is_power_of_2(mps))
6084 return -EINVAL;
6085
6086 v = ffs(mps) - 8;
6087 if (v > dev->pcie_mpss)
6088 return -EINVAL;
6089 v <<= 5;
6090
6091 ret = pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
6092 PCI_EXP_DEVCTL_PAYLOAD, v);
6093
6094 return pcibios_err_to_errno(ret);
6095}
6096EXPORT_SYMBOL(pcie_set_mps);
6097
6098/**
6099 * pcie_bandwidth_available - determine minimum link settings of a PCIe
6100 * device and its bandwidth limitation
6101 * @dev: PCI device to query
6102 * @limiting_dev: storage for device causing the bandwidth limitation
6103 * @speed: storage for speed of limiting device
6104 * @width: storage for width of limiting device
6105 *
6106 * Walk up the PCI device chain and find the point where the minimum
6107 * bandwidth is available. Return the bandwidth available there and (if
6108 * limiting_dev, speed, and width pointers are supplied) information about
6109 * that point. The bandwidth returned is in Mb/s, i.e., megabits/second of
6110 * raw bandwidth.
6111 */
6112u32 pcie_bandwidth_available(struct pci_dev *dev, struct pci_dev **limiting_dev,
6113 enum pci_bus_speed *speed,
6114 enum pcie_link_width *width)
6115{
6116 u16 lnksta;
6117 enum pci_bus_speed next_speed;
6118 enum pcie_link_width next_width;
6119 u32 bw, next_bw;
6120
6121 if (speed)
6122 *speed = PCI_SPEED_UNKNOWN;
6123 if (width)
6124 *width = PCIE_LNK_WIDTH_UNKNOWN;
6125
6126 bw = 0;
6127
6128 while (dev) {
6129 pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta);
6130
6131 next_speed = pcie_link_speed[lnksta & PCI_EXP_LNKSTA_CLS];
6132 next_width = (lnksta & PCI_EXP_LNKSTA_NLW) >>
6133 PCI_EXP_LNKSTA_NLW_SHIFT;
6134
6135 next_bw = next_width * PCIE_SPEED2MBS_ENC(next_speed);
6136
6137 /* Check if current device limits the total bandwidth */
6138 if (!bw || next_bw <= bw) {
6139 bw = next_bw;
6140
6141 if (limiting_dev)
6142 *limiting_dev = dev;
6143 if (speed)
6144 *speed = next_speed;
6145 if (width)
6146 *width = next_width;
6147 }
6148
6149 dev = pci_upstream_bridge(dev);
6150 }
6151
6152 return bw;
6153}
6154EXPORT_SYMBOL(pcie_bandwidth_available);
6155
6156/**
6157 * pcie_get_speed_cap - query for the PCI device's link speed capability
6158 * @dev: PCI device to query
6159 *
6160 * Query the PCI device speed capability. Return the maximum link speed
6161 * supported by the device.
6162 */
6163enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev)
6164{
6165 u32 lnkcap2, lnkcap;
6166
6167 /*
6168 * Link Capabilities 2 was added in PCIe r3.0, sec 7.8.18. The
6169 * implementation note there recommends using the Supported Link
6170 * Speeds Vector in Link Capabilities 2 when supported.
6171 *
6172 * Without Link Capabilities 2, i.e., prior to PCIe r3.0, software
6173 * should use the Supported Link Speeds field in Link Capabilities,
6174 * where only 2.5 GT/s and 5.0 GT/s speeds were defined.
6175 */
6176 pcie_capability_read_dword(dev, PCI_EXP_LNKCAP2, &lnkcap2);
6177
6178 /* PCIe r3.0-compliant */
6179 if (lnkcap2)
6180 return PCIE_LNKCAP2_SLS2SPEED(lnkcap2);
6181
6182 pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap);
6183 if ((lnkcap & PCI_EXP_LNKCAP_SLS) == PCI_EXP_LNKCAP_SLS_5_0GB)
6184 return PCIE_SPEED_5_0GT;
6185 else if ((lnkcap & PCI_EXP_LNKCAP_SLS) == PCI_EXP_LNKCAP_SLS_2_5GB)
6186 return PCIE_SPEED_2_5GT;
6187
6188 return PCI_SPEED_UNKNOWN;
6189}
6190EXPORT_SYMBOL(pcie_get_speed_cap);
6191
6192/**
6193 * pcie_get_width_cap - query for the PCI device's link width capability
6194 * @dev: PCI device to query
6195 *
6196 * Query the PCI device width capability. Return the maximum link width
6197 * supported by the device.
6198 */
6199enum pcie_link_width pcie_get_width_cap(struct pci_dev *dev)
6200{
6201 u32 lnkcap;
6202
6203 pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap);
6204 if (lnkcap)
6205 return (lnkcap & PCI_EXP_LNKCAP_MLW) >> 4;
6206
6207 return PCIE_LNK_WIDTH_UNKNOWN;
6208}
6209EXPORT_SYMBOL(pcie_get_width_cap);
6210
6211/**
6212 * pcie_bandwidth_capable - calculate a PCI device's link bandwidth capability
6213 * @dev: PCI device
6214 * @speed: storage for link speed
6215 * @width: storage for link width
6216 *
6217 * Calculate a PCI device's link bandwidth by querying for its link speed
6218 * and width, multiplying them, and applying encoding overhead. The result
6219 * is in Mb/s, i.e., megabits/second of raw bandwidth.
6220 */
6221u32 pcie_bandwidth_capable(struct pci_dev *dev, enum pci_bus_speed *speed,
6222 enum pcie_link_width *width)
6223{
6224 *speed = pcie_get_speed_cap(dev);
6225 *width = pcie_get_width_cap(dev);
6226
6227 if (*speed == PCI_SPEED_UNKNOWN || *width == PCIE_LNK_WIDTH_UNKNOWN)
6228 return 0;
6229
6230 return *width * PCIE_SPEED2MBS_ENC(*speed);
6231}
6232
6233/**
6234 * __pcie_print_link_status - Report the PCI device's link speed and width
6235 * @dev: PCI device to query
6236 * @verbose: Print info even when enough bandwidth is available
6237 *
6238 * If the available bandwidth at the device is less than the device is
6239 * capable of, report the device's maximum possible bandwidth and the
6240 * upstream link that limits its performance. If @verbose, always print
6241 * the available bandwidth, even if the device isn't constrained.
6242 */
6243void __pcie_print_link_status(struct pci_dev *dev, bool verbose)
6244{
6245 enum pcie_link_width width, width_cap;
6246 enum pci_bus_speed speed, speed_cap;
6247 struct pci_dev *limiting_dev = NULL;
6248 u32 bw_avail, bw_cap;
6249
6250 bw_cap = pcie_bandwidth_capable(dev, &speed_cap, &width_cap);
6251 bw_avail = pcie_bandwidth_available(dev, &limiting_dev, &speed, &width);
6252
6253 if (bw_avail >= bw_cap && verbose)
6254 pci_info(dev, "%u.%03u Gb/s available PCIe bandwidth (%s x%d link)\n",
6255 bw_cap / 1000, bw_cap % 1000,
6256 pci_speed_string(speed_cap), width_cap);
6257 else if (bw_avail < bw_cap)
6258 pci_info(dev, "%u.%03u Gb/s available PCIe bandwidth, limited by %s x%d link at %s (capable of %u.%03u Gb/s with %s x%d link)\n",
6259 bw_avail / 1000, bw_avail % 1000,
6260 pci_speed_string(speed), width,
6261 limiting_dev ? pci_name(limiting_dev) : "<unknown>",
6262 bw_cap / 1000, bw_cap % 1000,
6263 pci_speed_string(speed_cap), width_cap);
6264}
6265
6266/**
6267 * pcie_print_link_status - Report the PCI device's link speed and width
6268 * @dev: PCI device to query
6269 *
6270 * Report the available bandwidth at the device.
6271 */
6272void pcie_print_link_status(struct pci_dev *dev)
6273{
6274 __pcie_print_link_status(dev, true);
6275}
6276EXPORT_SYMBOL(pcie_print_link_status);
6277
6278/**
6279 * pci_select_bars - Make BAR mask from the type of resource
6280 * @dev: the PCI device for which BAR mask is made
6281 * @flags: resource type mask to be selected
6282 *
6283 * This helper routine makes bar mask from the type of resource.
6284 */
6285int pci_select_bars(struct pci_dev *dev, unsigned long flags)
6286{
6287 int i, bars = 0;
6288 for (i = 0; i < PCI_NUM_RESOURCES; i++)
6289 if (pci_resource_flags(dev, i) & flags)
6290 bars |= (1 << i);
6291 return bars;
6292}
6293EXPORT_SYMBOL(pci_select_bars);
6294
6295/* Some architectures require additional programming to enable VGA */
6296static arch_set_vga_state_t arch_set_vga_state;
6297
6298void __init pci_register_set_vga_state(arch_set_vga_state_t func)
6299{
6300 arch_set_vga_state = func; /* NULL disables */
6301}
6302
6303static int pci_set_vga_state_arch(struct pci_dev *dev, bool decode,
6304 unsigned int command_bits, u32 flags)
6305{
6306 if (arch_set_vga_state)
6307 return arch_set_vga_state(dev, decode, command_bits,
6308 flags);
6309 return 0;
6310}
6311
6312/**
6313 * pci_set_vga_state - set VGA decode state on device and parents if requested
6314 * @dev: the PCI device
6315 * @decode: true = enable decoding, false = disable decoding
6316 * @command_bits: PCI_COMMAND_IO and/or PCI_COMMAND_MEMORY
6317 * @flags: traverse ancestors and change bridges
6318 * CHANGE_BRIDGE_ONLY / CHANGE_BRIDGE
6319 */
6320int pci_set_vga_state(struct pci_dev *dev, bool decode,
6321 unsigned int command_bits, u32 flags)
6322{
6323 struct pci_bus *bus;
6324 struct pci_dev *bridge;
6325 u16 cmd;
6326 int rc;
6327
6328 WARN_ON((flags & PCI_VGA_STATE_CHANGE_DECODES) && (command_bits & ~(PCI_COMMAND_IO|PCI_COMMAND_MEMORY)));
6329
6330 /* ARCH specific VGA enables */
6331 rc = pci_set_vga_state_arch(dev, decode, command_bits, flags);
6332 if (rc)
6333 return rc;
6334
6335 if (flags & PCI_VGA_STATE_CHANGE_DECODES) {
6336 pci_read_config_word(dev, PCI_COMMAND, &cmd);
6337 if (decode)
6338 cmd |= command_bits;
6339 else
6340 cmd &= ~command_bits;
6341 pci_write_config_word(dev, PCI_COMMAND, cmd);
6342 }
6343
6344 if (!(flags & PCI_VGA_STATE_CHANGE_BRIDGE))
6345 return 0;
6346
6347 bus = dev->bus;
6348 while (bus) {
6349 bridge = bus->self;
6350 if (bridge) {
6351 pci_read_config_word(bridge, PCI_BRIDGE_CONTROL,
6352 &cmd);
6353 if (decode)
6354 cmd |= PCI_BRIDGE_CTL_VGA;
6355 else
6356 cmd &= ~PCI_BRIDGE_CTL_VGA;
6357 pci_write_config_word(bridge, PCI_BRIDGE_CONTROL,
6358 cmd);
6359 }
6360 bus = bus->parent;
6361 }
6362 return 0;
6363}
6364
6365#ifdef CONFIG_ACPI
6366bool pci_pr3_present(struct pci_dev *pdev)
6367{
6368 struct acpi_device *adev;
6369
6370 if (acpi_disabled)
6371 return false;
6372
6373 adev = ACPI_COMPANION(&pdev->dev);
6374 if (!adev)
6375 return false;
6376
6377 return adev->power.flags.power_resources &&
6378 acpi_has_method(adev->handle, "_PR3");
6379}
6380EXPORT_SYMBOL_GPL(pci_pr3_present);
6381#endif
6382
6383/**
6384 * pci_add_dma_alias - Add a DMA devfn alias for a device
6385 * @dev: the PCI device for which alias is added
6386 * @devfn_from: alias slot and function
6387 * @nr_devfns: number of subsequent devfns to alias
6388 *
6389 * This helper encodes an 8-bit devfn as a bit number in dma_alias_mask
6390 * which is used to program permissible bus-devfn source addresses for DMA
6391 * requests in an IOMMU. These aliases factor into IOMMU group creation
6392 * and are useful for devices generating DMA requests beyond or different
6393 * from their logical bus-devfn. Examples include device quirks where the
6394 * device simply uses the wrong devfn, as well as non-transparent bridges
6395 * where the alias may be a proxy for devices in another domain.
6396 *
6397 * IOMMU group creation is performed during device discovery or addition,
6398 * prior to any potential DMA mapping and therefore prior to driver probing
6399 * (especially for userspace assigned devices where IOMMU group definition
6400 * cannot be left as a userspace activity). DMA aliases should therefore
6401 * be configured via quirks, such as the PCI fixup header quirk.
6402 */
6403void pci_add_dma_alias(struct pci_dev *dev, u8 devfn_from,
6404 unsigned int nr_devfns)
6405{
6406 int devfn_to;
6407
6408 nr_devfns = min(nr_devfns, (unsigned int)MAX_NR_DEVFNS - devfn_from);
6409 devfn_to = devfn_from + nr_devfns - 1;
6410
6411 if (!dev->dma_alias_mask)
6412 dev->dma_alias_mask = bitmap_zalloc(MAX_NR_DEVFNS, GFP_KERNEL);
6413 if (!dev->dma_alias_mask) {
6414 pci_warn(dev, "Unable to allocate DMA alias mask\n");
6415 return;
6416 }
6417
6418 bitmap_set(dev->dma_alias_mask, devfn_from, nr_devfns);
6419
6420 if (nr_devfns == 1)
6421 pci_info(dev, "Enabling fixed DMA alias to %02x.%d\n",
6422 PCI_SLOT(devfn_from), PCI_FUNC(devfn_from));
6423 else if (nr_devfns > 1)
6424 pci_info(dev, "Enabling fixed DMA alias for devfn range from %02x.%d to %02x.%d\n",
6425 PCI_SLOT(devfn_from), PCI_FUNC(devfn_from),
6426 PCI_SLOT(devfn_to), PCI_FUNC(devfn_to));
6427}
6428
6429bool pci_devs_are_dma_aliases(struct pci_dev *dev1, struct pci_dev *dev2)
6430{
6431 return (dev1->dma_alias_mask &&
6432 test_bit(dev2->devfn, dev1->dma_alias_mask)) ||
6433 (dev2->dma_alias_mask &&
6434 test_bit(dev1->devfn, dev2->dma_alias_mask)) ||
6435 pci_real_dma_dev(dev1) == dev2 ||
6436 pci_real_dma_dev(dev2) == dev1;
6437}
6438
6439bool pci_device_is_present(struct pci_dev *pdev)
6440{
6441 u32 v;
6442
6443 /* Check PF if pdev is a VF, since VF Vendor/Device IDs are 0xffff */
6444 pdev = pci_physfn(pdev);
6445 if (pci_dev_is_disconnected(pdev))
6446 return false;
6447 return pci_bus_read_dev_vendor_id(pdev->bus, pdev->devfn, &v, 0);
6448}
6449EXPORT_SYMBOL_GPL(pci_device_is_present);
6450
6451void pci_ignore_hotplug(struct pci_dev *dev)
6452{
6453 struct pci_dev *bridge = dev->bus->self;
6454
6455 dev->ignore_hotplug = 1;
6456 /* Propagate the "ignore hotplug" setting to the parent bridge. */
6457 if (bridge)
6458 bridge->ignore_hotplug = 1;
6459}
6460EXPORT_SYMBOL_GPL(pci_ignore_hotplug);
6461
6462/**
6463 * pci_real_dma_dev - Get PCI DMA device for PCI device
6464 * @dev: the PCI device that may have a PCI DMA alias
6465 *
6466 * Permits the platform to provide architecture-specific functionality to
6467 * devices needing to alias DMA to another PCI device on another PCI bus. If
6468 * the PCI device is on the same bus, it is recommended to use
6469 * pci_add_dma_alias(). This is the default implementation. Architecture
6470 * implementations can override this.
6471 */
6472struct pci_dev __weak *pci_real_dma_dev(struct pci_dev *dev)
6473{
6474 return dev;
6475}
6476
6477resource_size_t __weak pcibios_default_alignment(void)
6478{
6479 return 0;
6480}
6481
6482/*
6483 * Arches that don't want to expose struct resource to userland as-is in
6484 * sysfs and /proc can implement their own pci_resource_to_user().
6485 */
6486void __weak pci_resource_to_user(const struct pci_dev *dev, int bar,
6487 const struct resource *rsrc,
6488 resource_size_t *start, resource_size_t *end)
6489{
6490 *start = rsrc->start;
6491 *end = rsrc->end;
6492}
6493
6494static char *resource_alignment_param;
6495static DEFINE_SPINLOCK(resource_alignment_lock);
6496
6497/**
6498 * pci_specified_resource_alignment - get resource alignment specified by user.
6499 * @dev: the PCI device to get
6500 * @resize: whether or not to change resources' size when reassigning alignment
6501 *
6502 * RETURNS: Resource alignment if it is specified.
6503 * Zero if it is not specified.
6504 */
6505static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev,
6506 bool *resize)
6507{
6508 int align_order, count;
6509 resource_size_t align = pcibios_default_alignment();
6510 const char *p;
6511 int ret;
6512
6513 spin_lock(&resource_alignment_lock);
6514 p = resource_alignment_param;
6515 if (!p || !*p)
6516 goto out;
6517 if (pci_has_flag(PCI_PROBE_ONLY)) {
6518 align = 0;
6519 pr_info_once("PCI: Ignoring requested alignments (PCI_PROBE_ONLY)\n");
6520 goto out;
6521 }
6522
6523 while (*p) {
6524 count = 0;
6525 if (sscanf(p, "%d%n", &align_order, &count) == 1 &&
6526 p[count] == '@') {
6527 p += count + 1;
6528 if (align_order > 63) {
6529 pr_err("PCI: Invalid requested alignment (order %d)\n",
6530 align_order);
6531 align_order = PAGE_SHIFT;
6532 }
6533 } else {
6534 align_order = PAGE_SHIFT;
6535 }
6536
6537 ret = pci_dev_str_match(dev, p, &p);
6538 if (ret == 1) {
6539 *resize = true;
6540 align = 1ULL << align_order;
6541 break;
6542 } else if (ret < 0) {
6543 pr_err("PCI: Can't parse resource_alignment parameter: %s\n",
6544 p);
6545 break;
6546 }
6547
6548 if (*p != ';' && *p != ',') {
6549 /* End of param or invalid format */
6550 break;
6551 }
6552 p++;
6553 }
6554out:
6555 spin_unlock(&resource_alignment_lock);
6556 return align;
6557}
6558
6559static void pci_request_resource_alignment(struct pci_dev *dev, int bar,
6560 resource_size_t align, bool resize)
6561{
6562 struct resource *r = &dev->resource[bar];
6563 resource_size_t size;
6564
6565 if (!(r->flags & IORESOURCE_MEM))
6566 return;
6567
6568 if (r->flags & IORESOURCE_PCI_FIXED) {
6569 pci_info(dev, "BAR%d %pR: ignoring requested alignment %#llx\n",
6570 bar, r, (unsigned long long)align);
6571 return;
6572 }
6573
6574 size = resource_size(r);
6575 if (size >= align)
6576 return;
6577
6578 /*
6579 * Increase the alignment of the resource. There are two ways we
6580 * can do this:
6581 *
6582 * 1) Increase the size of the resource. BARs are aligned on their
6583 * size, so when we reallocate space for this resource, we'll
6584 * allocate it with the larger alignment. This also prevents
6585 * assignment of any other BARs inside the alignment region, so
6586 * if we're requesting page alignment, this means no other BARs
6587 * will share the page.
6588 *
6589 * The disadvantage is that this makes the resource larger than
6590 * the hardware BAR, which may break drivers that compute things
6591 * based on the resource size, e.g., to find registers at a
6592 * fixed offset before the end of the BAR.
6593 *
6594 * 2) Retain the resource size, but use IORESOURCE_STARTALIGN and
6595 * set r->start to the desired alignment. By itself this
6596 * doesn't prevent other BARs being put inside the alignment
6597 * region, but if we realign *every* resource of every device in
6598 * the system, none of them will share an alignment region.
6599 *
6600 * When the user has requested alignment for only some devices via
6601 * the "pci=resource_alignment" argument, "resize" is true and we
6602 * use the first method. Otherwise we assume we're aligning all
6603 * devices and we use the second.
6604 */
6605
6606 pci_info(dev, "BAR%d %pR: requesting alignment to %#llx\n",
6607 bar, r, (unsigned long long)align);
6608
6609 if (resize) {
6610 r->start = 0;
6611 r->end = align - 1;
6612 } else {
6613 r->flags &= ~IORESOURCE_SIZEALIGN;
6614 r->flags |= IORESOURCE_STARTALIGN;
6615 r->start = align;
6616 r->end = r->start + size - 1;
6617 }
6618 r->flags |= IORESOURCE_UNSET;
6619}
6620
6621/*
6622 * This function disables memory decoding and releases memory resources
6623 * of the device specified by kernel's boot parameter 'pci=resource_alignment='.
6624 * It also rounds up size to specified alignment.
6625 * Later on, the kernel will assign page-aligned memory resource back
6626 * to the device.
6627 */
6628void pci_reassigndev_resource_alignment(struct pci_dev *dev)
6629{
6630 int i;
6631 struct resource *r;
6632 resource_size_t align;
6633 u16 command;
6634 bool resize = false;
6635
6636 /*
6637 * VF BARs are read-only zero according to SR-IOV spec r1.1, sec
6638 * 3.4.1.11. Their resources are allocated from the space
6639 * described by the VF BARx register in the PF's SR-IOV capability.
6640 * We can't influence their alignment here.
6641 */
6642 if (dev->is_virtfn)
6643 return;
6644
6645 /* check if specified PCI is target device to reassign */
6646 align = pci_specified_resource_alignment(dev, &resize);
6647 if (!align)
6648 return;
6649
6650 if (dev->hdr_type == PCI_HEADER_TYPE_NORMAL &&
6651 (dev->class >> 8) == PCI_CLASS_BRIDGE_HOST) {
6652 pci_warn(dev, "Can't reassign resources to host bridge\n");
6653 return;
6654 }
6655
6656 pci_read_config_word(dev, PCI_COMMAND, &command);
6657 command &= ~PCI_COMMAND_MEMORY;
6658 pci_write_config_word(dev, PCI_COMMAND, command);
6659
6660 for (i = 0; i <= PCI_ROM_RESOURCE; i++)
6661 pci_request_resource_alignment(dev, i, align, resize);
6662
6663 /*
6664 * Need to disable bridge's resource window,
6665 * to enable the kernel to reassign new resource
6666 * window later on.
6667 */
6668 if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
6669 for (i = PCI_BRIDGE_RESOURCES; i < PCI_NUM_RESOURCES; i++) {
6670 r = &dev->resource[i];
6671 if (!(r->flags & IORESOURCE_MEM))
6672 continue;
6673 r->flags |= IORESOURCE_UNSET;
6674 r->end = resource_size(r) - 1;
6675 r->start = 0;
6676 }
6677 pci_disable_bridge_window(dev);
6678 }
6679}
6680
6681static ssize_t resource_alignment_show(struct bus_type *bus, char *buf)
6682{
6683 size_t count = 0;
6684
6685 spin_lock(&resource_alignment_lock);
6686 if (resource_alignment_param)
6687 count = sysfs_emit(buf, "%s\n", resource_alignment_param);
6688 spin_unlock(&resource_alignment_lock);
6689
6690 return count;
6691}
6692
6693static ssize_t resource_alignment_store(struct bus_type *bus,
6694 const char *buf, size_t count)
6695{
6696 char *param, *old, *end;
6697
6698 if (count >= (PAGE_SIZE - 1))
6699 return -EINVAL;
6700
6701 param = kstrndup(buf, count, GFP_KERNEL);
6702 if (!param)
6703 return -ENOMEM;
6704
6705 end = strchr(param, '\n');
6706 if (end)
6707 *end = '\0';
6708
6709 spin_lock(&resource_alignment_lock);
6710 old = resource_alignment_param;
6711 if (strlen(param)) {
6712 resource_alignment_param = param;
6713 } else {
6714 kfree(param);
6715 resource_alignment_param = NULL;
6716 }
6717 spin_unlock(&resource_alignment_lock);
6718
6719 kfree(old);
6720
6721 return count;
6722}
6723
6724static BUS_ATTR_RW(resource_alignment);
6725
6726static int __init pci_resource_alignment_sysfs_init(void)
6727{
6728 return bus_create_file(&pci_bus_type,
6729 &bus_attr_resource_alignment);
6730}
6731late_initcall(pci_resource_alignment_sysfs_init);
6732
6733static void pci_no_domains(void)
6734{
6735#ifdef CONFIG_PCI_DOMAINS
6736 pci_domains_supported = 0;
6737#endif
6738}
6739
6740#ifdef CONFIG_PCI_DOMAINS_GENERIC
6741static DEFINE_IDA(pci_domain_nr_static_ida);
6742static DEFINE_IDA(pci_domain_nr_dynamic_ida);
6743
6744static void of_pci_reserve_static_domain_nr(void)
6745{
6746 struct device_node *np;
6747 int domain_nr;
6748
6749 for_each_node_by_type(np, "pci") {
6750 domain_nr = of_get_pci_domain_nr(np);
6751 if (domain_nr < 0)
6752 continue;
6753 /*
6754 * Permanently allocate domain_nr in dynamic_ida
6755 * to prevent it from dynamic allocation.
6756 */
6757 ida_alloc_range(&pci_domain_nr_dynamic_ida,
6758 domain_nr, domain_nr, GFP_KERNEL);
6759 }
6760}
6761
6762static int of_pci_bus_find_domain_nr(struct device *parent)
6763{
6764 static bool static_domains_reserved = false;
6765 int domain_nr;
6766
6767 /* On the first call scan device tree for static allocations. */
6768 if (!static_domains_reserved) {
6769 of_pci_reserve_static_domain_nr();
6770 static_domains_reserved = true;
6771 }
6772
6773 if (parent) {
6774 /*
6775 * If domain is in DT, allocate it in static IDA. This
6776 * prevents duplicate static allocations in case of errors
6777 * in DT.
6778 */
6779 domain_nr = of_get_pci_domain_nr(parent->of_node);
6780 if (domain_nr >= 0)
6781 return ida_alloc_range(&pci_domain_nr_static_ida,
6782 domain_nr, domain_nr,
6783 GFP_KERNEL);
6784 }
6785
6786 /*
6787 * If domain was not specified in DT, choose a free ID from dynamic
6788 * allocations. All domain numbers from DT are permanently in
6789 * dynamic allocations to prevent assigning them to other DT nodes
6790 * without static domain.
6791 */
6792 return ida_alloc(&pci_domain_nr_dynamic_ida, GFP_KERNEL);
6793}
6794
6795static void of_pci_bus_release_domain_nr(struct pci_bus *bus, struct device *parent)
6796{
6797 if (bus->domain_nr < 0)
6798 return;
6799
6800 /* Release domain from IDA where it was allocated. */
6801 if (of_get_pci_domain_nr(parent->of_node) == bus->domain_nr)
6802 ida_free(&pci_domain_nr_static_ida, bus->domain_nr);
6803 else
6804 ida_free(&pci_domain_nr_dynamic_ida, bus->domain_nr);
6805}
6806
6807int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent)
6808{
6809 return acpi_disabled ? of_pci_bus_find_domain_nr(parent) :
6810 acpi_pci_bus_find_domain_nr(bus);
6811}
6812
6813void pci_bus_release_domain_nr(struct pci_bus *bus, struct device *parent)
6814{
6815 if (!acpi_disabled)
6816 return;
6817 of_pci_bus_release_domain_nr(bus, parent);
6818}
6819#endif
6820
6821/**
6822 * pci_ext_cfg_avail - can we access extended PCI config space?
6823 *
6824 * Returns 1 if we can access PCI extended config space (offsets
6825 * greater than 0xff). This is the default implementation. Architecture
6826 * implementations can override this.
6827 */
6828int __weak pci_ext_cfg_avail(void)
6829{
6830 return 1;
6831}
6832
6833void __weak pci_fixup_cardbus(struct pci_bus *bus)
6834{
6835}
6836EXPORT_SYMBOL(pci_fixup_cardbus);
6837
6838static int __init pci_setup(char *str)
6839{
6840 while (str) {
6841 char *k = strchr(str, ',');
6842 if (k)
6843 *k++ = 0;
6844 if (*str && (str = pcibios_setup(str)) && *str) {
6845 if (!strcmp(str, "nomsi")) {
6846 pci_no_msi();
6847 } else if (!strncmp(str, "noats", 5)) {
6848 pr_info("PCIe: ATS is disabled\n");
6849 pcie_ats_disabled = true;
6850 } else if (!strcmp(str, "noaer")) {
6851 pci_no_aer();
6852 } else if (!strcmp(str, "earlydump")) {
6853 pci_early_dump = true;
6854 } else if (!strncmp(str, "realloc=", 8)) {
6855 pci_realloc_get_opt(str + 8);
6856 } else if (!strncmp(str, "realloc", 7)) {
6857 pci_realloc_get_opt("on");
6858 } else if (!strcmp(str, "nodomains")) {
6859 pci_no_domains();
6860 } else if (!strncmp(str, "noari", 5)) {
6861 pcie_ari_disabled = true;
6862 } else if (!strncmp(str, "cbiosize=", 9)) {
6863 pci_cardbus_io_size = memparse(str + 9, &str);
6864 } else if (!strncmp(str, "cbmemsize=", 10)) {
6865 pci_cardbus_mem_size = memparse(str + 10, &str);
6866 } else if (!strncmp(str, "resource_alignment=", 19)) {
6867 resource_alignment_param = str + 19;
6868 } else if (!strncmp(str, "ecrc=", 5)) {
6869 pcie_ecrc_get_policy(str + 5);
6870 } else if (!strncmp(str, "hpiosize=", 9)) {
6871 pci_hotplug_io_size = memparse(str + 9, &str);
6872 } else if (!strncmp(str, "hpmmiosize=", 11)) {
6873 pci_hotplug_mmio_size = memparse(str + 11, &str);
6874 } else if (!strncmp(str, "hpmmioprefsize=", 15)) {
6875 pci_hotplug_mmio_pref_size = memparse(str + 15, &str);
6876 } else if (!strncmp(str, "hpmemsize=", 10)) {
6877 pci_hotplug_mmio_size = memparse(str + 10, &str);
6878 pci_hotplug_mmio_pref_size = pci_hotplug_mmio_size;
6879 } else if (!strncmp(str, "hpbussize=", 10)) {
6880 pci_hotplug_bus_size =
6881 simple_strtoul(str + 10, &str, 0);
6882 if (pci_hotplug_bus_size > 0xff)
6883 pci_hotplug_bus_size = DEFAULT_HOTPLUG_BUS_SIZE;
6884 } else if (!strncmp(str, "pcie_bus_tune_off", 17)) {
6885 pcie_bus_config = PCIE_BUS_TUNE_OFF;
6886 } else if (!strncmp(str, "pcie_bus_safe", 13)) {
6887 pcie_bus_config = PCIE_BUS_SAFE;
6888 } else if (!strncmp(str, "pcie_bus_perf", 13)) {
6889 pcie_bus_config = PCIE_BUS_PERFORMANCE;
6890 } else if (!strncmp(str, "pcie_bus_peer2peer", 18)) {
6891 pcie_bus_config = PCIE_BUS_PEER2PEER;
6892 } else if (!strncmp(str, "pcie_scan_all", 13)) {
6893 pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS);
6894 } else if (!strncmp(str, "disable_acs_redir=", 18)) {
6895 disable_acs_redir_param = str + 18;
6896 } else {
6897 pr_err("PCI: Unknown option `%s'\n", str);
6898 }
6899 }
6900 str = k;
6901 }
6902 return 0;
6903}
6904early_param("pci", pci_setup);
6905
6906/*
6907 * 'resource_alignment_param' and 'disable_acs_redir_param' are initialized
6908 * in pci_setup(), above, to point to data in the __initdata section which
6909 * will be freed after the init sequence is complete. We can't allocate memory
6910 * in pci_setup() because some architectures do not have any memory allocation
6911 * service available during an early_param() call. So we allocate memory and
6912 * copy the variable here before the init section is freed.
6913 *
6914 */
6915static int __init pci_realloc_setup_params(void)
6916{
6917 resource_alignment_param = kstrdup(resource_alignment_param,
6918 GFP_KERNEL);
6919 disable_acs_redir_param = kstrdup(disable_acs_redir_param, GFP_KERNEL);
6920
6921 return 0;
6922}
6923pure_initcall(pci_realloc_setup_params);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * PCI Bus Services, see include/linux/pci.h for further explanation.
4 *
5 * Copyright 1993 -- 1997 Drew Eckhardt, Frederic Potter,
6 * David Mosberger-Tang
7 *
8 * Copyright 1997 -- 2000 Martin Mares <mj@ucw.cz>
9 */
10
11#include <linux/acpi.h>
12#include <linux/kernel.h>
13#include <linux/delay.h>
14#include <linux/dmi.h>
15#include <linux/init.h>
16#include <linux/of.h>
17#include <linux/of_pci.h>
18#include <linux/pci.h>
19#include <linux/pm.h>
20#include <linux/slab.h>
21#include <linux/module.h>
22#include <linux/spinlock.h>
23#include <linux/string.h>
24#include <linux/log2.h>
25#include <linux/logic_pio.h>
26#include <linux/pci-aspm.h>
27#include <linux/pm_wakeup.h>
28#include <linux/interrupt.h>
29#include <linux/device.h>
30#include <linux/pm_runtime.h>
31#include <linux/pci_hotplug.h>
32#include <linux/vmalloc.h>
33#include <linux/pci-ats.h>
34#include <asm/setup.h>
35#include <asm/dma.h>
36#include <linux/aer.h>
37#include "pci.h"
38
39const char *pci_power_names[] = {
40 "error", "D0", "D1", "D2", "D3hot", "D3cold", "unknown",
41};
42EXPORT_SYMBOL_GPL(pci_power_names);
43
44int isa_dma_bridge_buggy;
45EXPORT_SYMBOL(isa_dma_bridge_buggy);
46
47int pci_pci_problems;
48EXPORT_SYMBOL(pci_pci_problems);
49
50unsigned int pci_pm_d3_delay;
51
52static void pci_pme_list_scan(struct work_struct *work);
53
54static LIST_HEAD(pci_pme_list);
55static DEFINE_MUTEX(pci_pme_list_mutex);
56static DECLARE_DELAYED_WORK(pci_pme_work, pci_pme_list_scan);
57
58struct pci_pme_device {
59 struct list_head list;
60 struct pci_dev *dev;
61};
62
63#define PME_TIMEOUT 1000 /* How long between PME checks */
64
65static void pci_dev_d3_sleep(struct pci_dev *dev)
66{
67 unsigned int delay = dev->d3_delay;
68
69 if (delay < pci_pm_d3_delay)
70 delay = pci_pm_d3_delay;
71
72 if (delay)
73 msleep(delay);
74}
75
76#ifdef CONFIG_PCI_DOMAINS
77int pci_domains_supported = 1;
78#endif
79
80#define DEFAULT_CARDBUS_IO_SIZE (256)
81#define DEFAULT_CARDBUS_MEM_SIZE (64*1024*1024)
82/* pci=cbmemsize=nnM,cbiosize=nn can override this */
83unsigned long pci_cardbus_io_size = DEFAULT_CARDBUS_IO_SIZE;
84unsigned long pci_cardbus_mem_size = DEFAULT_CARDBUS_MEM_SIZE;
85
86#define DEFAULT_HOTPLUG_IO_SIZE (256)
87#define DEFAULT_HOTPLUG_MEM_SIZE (2*1024*1024)
88/* pci=hpmemsize=nnM,hpiosize=nn can override this */
89unsigned long pci_hotplug_io_size = DEFAULT_HOTPLUG_IO_SIZE;
90unsigned long pci_hotplug_mem_size = DEFAULT_HOTPLUG_MEM_SIZE;
91
92#define DEFAULT_HOTPLUG_BUS_SIZE 1
93unsigned long pci_hotplug_bus_size = DEFAULT_HOTPLUG_BUS_SIZE;
94
95enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_DEFAULT;
96
97/*
98 * The default CLS is used if arch didn't set CLS explicitly and not
99 * all pci devices agree on the same value. Arch can override either
100 * the dfl or actual value as it sees fit. Don't forget this is
101 * measured in 32-bit words, not bytes.
102 */
103u8 pci_dfl_cache_line_size = L1_CACHE_BYTES >> 2;
104u8 pci_cache_line_size;
105
106/*
107 * If we set up a device for bus mastering, we need to check the latency
108 * timer as certain BIOSes forget to set it properly.
109 */
110unsigned int pcibios_max_latency = 255;
111
112/* If set, the PCIe ARI capability will not be used. */
113static bool pcie_ari_disabled;
114
115/* Disable bridge_d3 for all PCIe ports */
116static bool pci_bridge_d3_disable;
117/* Force bridge_d3 for all PCIe ports */
118static bool pci_bridge_d3_force;
119
120static int __init pcie_port_pm_setup(char *str)
121{
122 if (!strcmp(str, "off"))
123 pci_bridge_d3_disable = true;
124 else if (!strcmp(str, "force"))
125 pci_bridge_d3_force = true;
126 return 1;
127}
128__setup("pcie_port_pm=", pcie_port_pm_setup);
129
130/* Time to wait after a reset for device to become responsive */
131#define PCIE_RESET_READY_POLL_MS 60000
132
133/**
134 * pci_bus_max_busnr - returns maximum PCI bus number of given bus' children
135 * @bus: pointer to PCI bus structure to search
136 *
137 * Given a PCI bus, returns the highest PCI bus number present in the set
138 * including the given PCI bus and its list of child PCI buses.
139 */
140unsigned char pci_bus_max_busnr(struct pci_bus *bus)
141{
142 struct pci_bus *tmp;
143 unsigned char max, n;
144
145 max = bus->busn_res.end;
146 list_for_each_entry(tmp, &bus->children, node) {
147 n = pci_bus_max_busnr(tmp);
148 if (n > max)
149 max = n;
150 }
151 return max;
152}
153EXPORT_SYMBOL_GPL(pci_bus_max_busnr);
154
155#ifdef CONFIG_HAS_IOMEM
156void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar)
157{
158 struct resource *res = &pdev->resource[bar];
159
160 /*
161 * Make sure the BAR is actually a memory resource, not an IO resource
162 */
163 if (res->flags & IORESOURCE_UNSET || !(res->flags & IORESOURCE_MEM)) {
164 pci_warn(pdev, "can't ioremap BAR %d: %pR\n", bar, res);
165 return NULL;
166 }
167 return ioremap_nocache(res->start, resource_size(res));
168}
169EXPORT_SYMBOL_GPL(pci_ioremap_bar);
170
171void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar)
172{
173 /*
174 * Make sure the BAR is actually a memory resource, not an IO resource
175 */
176 if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM)) {
177 WARN_ON(1);
178 return NULL;
179 }
180 return ioremap_wc(pci_resource_start(pdev, bar),
181 pci_resource_len(pdev, bar));
182}
183EXPORT_SYMBOL_GPL(pci_ioremap_wc_bar);
184#endif
185
186
187static int __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn,
188 u8 pos, int cap, int *ttl)
189{
190 u8 id;
191 u16 ent;
192
193 pci_bus_read_config_byte(bus, devfn, pos, &pos);
194
195 while ((*ttl)--) {
196 if (pos < 0x40)
197 break;
198 pos &= ~3;
199 pci_bus_read_config_word(bus, devfn, pos, &ent);
200
201 id = ent & 0xff;
202 if (id == 0xff)
203 break;
204 if (id == cap)
205 return pos;
206 pos = (ent >> 8);
207 }
208 return 0;
209}
210
211static int __pci_find_next_cap(struct pci_bus *bus, unsigned int devfn,
212 u8 pos, int cap)
213{
214 int ttl = PCI_FIND_CAP_TTL;
215
216 return __pci_find_next_cap_ttl(bus, devfn, pos, cap, &ttl);
217}
218
219int pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap)
220{
221 return __pci_find_next_cap(dev->bus, dev->devfn,
222 pos + PCI_CAP_LIST_NEXT, cap);
223}
224EXPORT_SYMBOL_GPL(pci_find_next_capability);
225
226static int __pci_bus_find_cap_start(struct pci_bus *bus,
227 unsigned int devfn, u8 hdr_type)
228{
229 u16 status;
230
231 pci_bus_read_config_word(bus, devfn, PCI_STATUS, &status);
232 if (!(status & PCI_STATUS_CAP_LIST))
233 return 0;
234
235 switch (hdr_type) {
236 case PCI_HEADER_TYPE_NORMAL:
237 case PCI_HEADER_TYPE_BRIDGE:
238 return PCI_CAPABILITY_LIST;
239 case PCI_HEADER_TYPE_CARDBUS:
240 return PCI_CB_CAPABILITY_LIST;
241 }
242
243 return 0;
244}
245
246/**
247 * pci_find_capability - query for devices' capabilities
248 * @dev: PCI device to query
249 * @cap: capability code
250 *
251 * Tell if a device supports a given PCI capability.
252 * Returns the address of the requested capability structure within the
253 * device's PCI configuration space or 0 in case the device does not
254 * support it. Possible values for @cap:
255 *
256 * %PCI_CAP_ID_PM Power Management
257 * %PCI_CAP_ID_AGP Accelerated Graphics Port
258 * %PCI_CAP_ID_VPD Vital Product Data
259 * %PCI_CAP_ID_SLOTID Slot Identification
260 * %PCI_CAP_ID_MSI Message Signalled Interrupts
261 * %PCI_CAP_ID_CHSWP CompactPCI HotSwap
262 * %PCI_CAP_ID_PCIX PCI-X
263 * %PCI_CAP_ID_EXP PCI Express
264 */
265int pci_find_capability(struct pci_dev *dev, int cap)
266{
267 int pos;
268
269 pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);
270 if (pos)
271 pos = __pci_find_next_cap(dev->bus, dev->devfn, pos, cap);
272
273 return pos;
274}
275EXPORT_SYMBOL(pci_find_capability);
276
277/**
278 * pci_bus_find_capability - query for devices' capabilities
279 * @bus: the PCI bus to query
280 * @devfn: PCI device to query
281 * @cap: capability code
282 *
283 * Like pci_find_capability() but works for pci devices that do not have a
284 * pci_dev structure set up yet.
285 *
286 * Returns the address of the requested capability structure within the
287 * device's PCI configuration space or 0 in case the device does not
288 * support it.
289 */
290int pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap)
291{
292 int pos;
293 u8 hdr_type;
294
295 pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &hdr_type);
296
297 pos = __pci_bus_find_cap_start(bus, devfn, hdr_type & 0x7f);
298 if (pos)
299 pos = __pci_find_next_cap(bus, devfn, pos, cap);
300
301 return pos;
302}
303EXPORT_SYMBOL(pci_bus_find_capability);
304
305/**
306 * pci_find_next_ext_capability - Find an extended capability
307 * @dev: PCI device to query
308 * @start: address at which to start looking (0 to start at beginning of list)
309 * @cap: capability code
310 *
311 * Returns the address of the next matching extended capability structure
312 * within the device's PCI configuration space or 0 if the device does
313 * not support it. Some capabilities can occur several times, e.g., the
314 * vendor-specific capability, and this provides a way to find them all.
315 */
316int pci_find_next_ext_capability(struct pci_dev *dev, int start, int cap)
317{
318 u32 header;
319 int ttl;
320 int pos = PCI_CFG_SPACE_SIZE;
321
322 /* minimum 8 bytes per capability */
323 ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8;
324
325 if (dev->cfg_size <= PCI_CFG_SPACE_SIZE)
326 return 0;
327
328 if (start)
329 pos = start;
330
331 if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
332 return 0;
333
334 /*
335 * If we have no capabilities, this is indicated by cap ID,
336 * cap version and next pointer all being 0.
337 */
338 if (header == 0)
339 return 0;
340
341 while (ttl-- > 0) {
342 if (PCI_EXT_CAP_ID(header) == cap && pos != start)
343 return pos;
344
345 pos = PCI_EXT_CAP_NEXT(header);
346 if (pos < PCI_CFG_SPACE_SIZE)
347 break;
348
349 if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
350 break;
351 }
352
353 return 0;
354}
355EXPORT_SYMBOL_GPL(pci_find_next_ext_capability);
356
357/**
358 * pci_find_ext_capability - Find an extended capability
359 * @dev: PCI device to query
360 * @cap: capability code
361 *
362 * Returns the address of the requested extended capability structure
363 * within the device's PCI configuration space or 0 if the device does
364 * not support it. Possible values for @cap:
365 *
366 * %PCI_EXT_CAP_ID_ERR Advanced Error Reporting
367 * %PCI_EXT_CAP_ID_VC Virtual Channel
368 * %PCI_EXT_CAP_ID_DSN Device Serial Number
369 * %PCI_EXT_CAP_ID_PWR Power Budgeting
370 */
371int pci_find_ext_capability(struct pci_dev *dev, int cap)
372{
373 return pci_find_next_ext_capability(dev, 0, cap);
374}
375EXPORT_SYMBOL_GPL(pci_find_ext_capability);
376
377static int __pci_find_next_ht_cap(struct pci_dev *dev, int pos, int ht_cap)
378{
379 int rc, ttl = PCI_FIND_CAP_TTL;
380 u8 cap, mask;
381
382 if (ht_cap == HT_CAPTYPE_SLAVE || ht_cap == HT_CAPTYPE_HOST)
383 mask = HT_3BIT_CAP_MASK;
384 else
385 mask = HT_5BIT_CAP_MASK;
386
387 pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn, pos,
388 PCI_CAP_ID_HT, &ttl);
389 while (pos) {
390 rc = pci_read_config_byte(dev, pos + 3, &cap);
391 if (rc != PCIBIOS_SUCCESSFUL)
392 return 0;
393
394 if ((cap & mask) == ht_cap)
395 return pos;
396
397 pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn,
398 pos + PCI_CAP_LIST_NEXT,
399 PCI_CAP_ID_HT, &ttl);
400 }
401
402 return 0;
403}
404/**
405 * pci_find_next_ht_capability - query a device's Hypertransport capabilities
406 * @dev: PCI device to query
407 * @pos: Position from which to continue searching
408 * @ht_cap: Hypertransport capability code
409 *
410 * To be used in conjunction with pci_find_ht_capability() to search for
411 * all capabilities matching @ht_cap. @pos should always be a value returned
412 * from pci_find_ht_capability().
413 *
414 * NB. To be 100% safe against broken PCI devices, the caller should take
415 * steps to avoid an infinite loop.
416 */
417int pci_find_next_ht_capability(struct pci_dev *dev, int pos, int ht_cap)
418{
419 return __pci_find_next_ht_cap(dev, pos + PCI_CAP_LIST_NEXT, ht_cap);
420}
421EXPORT_SYMBOL_GPL(pci_find_next_ht_capability);
422
423/**
424 * pci_find_ht_capability - query a device's Hypertransport capabilities
425 * @dev: PCI device to query
426 * @ht_cap: Hypertransport capability code
427 *
428 * Tell if a device supports a given Hypertransport capability.
429 * Returns an address within the device's PCI configuration space
430 * or 0 in case the device does not support the request capability.
431 * The address points to the PCI capability, of type PCI_CAP_ID_HT,
432 * which has a Hypertransport capability matching @ht_cap.
433 */
434int pci_find_ht_capability(struct pci_dev *dev, int ht_cap)
435{
436 int pos;
437
438 pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);
439 if (pos)
440 pos = __pci_find_next_ht_cap(dev, pos, ht_cap);
441
442 return pos;
443}
444EXPORT_SYMBOL_GPL(pci_find_ht_capability);
445
446/**
447 * pci_find_parent_resource - return resource region of parent bus of given region
448 * @dev: PCI device structure contains resources to be searched
449 * @res: child resource record for which parent is sought
450 *
451 * For given resource region of given device, return the resource
452 * region of parent bus the given region is contained in.
453 */
454struct resource *pci_find_parent_resource(const struct pci_dev *dev,
455 struct resource *res)
456{
457 const struct pci_bus *bus = dev->bus;
458 struct resource *r;
459 int i;
460
461 pci_bus_for_each_resource(bus, r, i) {
462 if (!r)
463 continue;
464 if (resource_contains(r, res)) {
465
466 /*
467 * If the window is prefetchable but the BAR is
468 * not, the allocator made a mistake.
469 */
470 if (r->flags & IORESOURCE_PREFETCH &&
471 !(res->flags & IORESOURCE_PREFETCH))
472 return NULL;
473
474 /*
475 * If we're below a transparent bridge, there may
476 * be both a positively-decoded aperture and a
477 * subtractively-decoded region that contain the BAR.
478 * We want the positively-decoded one, so this depends
479 * on pci_bus_for_each_resource() giving us those
480 * first.
481 */
482 return r;
483 }
484 }
485 return NULL;
486}
487EXPORT_SYMBOL(pci_find_parent_resource);
488
489/**
490 * pci_find_resource - Return matching PCI device resource
491 * @dev: PCI device to query
492 * @res: Resource to look for
493 *
494 * Goes over standard PCI resources (BARs) and checks if the given resource
495 * is partially or fully contained in any of them. In that case the
496 * matching resource is returned, %NULL otherwise.
497 */
498struct resource *pci_find_resource(struct pci_dev *dev, struct resource *res)
499{
500 int i;
501
502 for (i = 0; i < PCI_ROM_RESOURCE; i++) {
503 struct resource *r = &dev->resource[i];
504
505 if (r->start && resource_contains(r, res))
506 return r;
507 }
508
509 return NULL;
510}
511EXPORT_SYMBOL(pci_find_resource);
512
513/**
514 * pci_find_pcie_root_port - return PCIe Root Port
515 * @dev: PCI device to query
516 *
517 * Traverse up the parent chain and return the PCIe Root Port PCI Device
518 * for a given PCI Device.
519 */
520struct pci_dev *pci_find_pcie_root_port(struct pci_dev *dev)
521{
522 struct pci_dev *bridge, *highest_pcie_bridge = dev;
523
524 bridge = pci_upstream_bridge(dev);
525 while (bridge && pci_is_pcie(bridge)) {
526 highest_pcie_bridge = bridge;
527 bridge = pci_upstream_bridge(bridge);
528 }
529
530 if (pci_pcie_type(highest_pcie_bridge) != PCI_EXP_TYPE_ROOT_PORT)
531 return NULL;
532
533 return highest_pcie_bridge;
534}
535EXPORT_SYMBOL(pci_find_pcie_root_port);
536
537/**
538 * pci_wait_for_pending - wait for @mask bit(s) to clear in status word @pos
539 * @dev: the PCI device to operate on
540 * @pos: config space offset of status word
541 * @mask: mask of bit(s) to care about in status word
542 *
543 * Return 1 when mask bit(s) in status word clear, 0 otherwise.
544 */
545int pci_wait_for_pending(struct pci_dev *dev, int pos, u16 mask)
546{
547 int i;
548
549 /* Wait for Transaction Pending bit clean */
550 for (i = 0; i < 4; i++) {
551 u16 status;
552 if (i)
553 msleep((1 << (i - 1)) * 100);
554
555 pci_read_config_word(dev, pos, &status);
556 if (!(status & mask))
557 return 1;
558 }
559
560 return 0;
561}
562
563/**
564 * pci_restore_bars - restore a device's BAR values (e.g. after wake-up)
565 * @dev: PCI device to have its BARs restored
566 *
567 * Restore the BAR values for a given device, so as to make it
568 * accessible by its driver.
569 */
570static void pci_restore_bars(struct pci_dev *dev)
571{
572 int i;
573
574 for (i = 0; i < PCI_BRIDGE_RESOURCES; i++)
575 pci_update_resource(dev, i);
576}
577
578static const struct pci_platform_pm_ops *pci_platform_pm;
579
580int pci_set_platform_pm(const struct pci_platform_pm_ops *ops)
581{
582 if (!ops->is_manageable || !ops->set_state || !ops->get_state ||
583 !ops->choose_state || !ops->set_wakeup || !ops->need_resume)
584 return -EINVAL;
585 pci_platform_pm = ops;
586 return 0;
587}
588
589static inline bool platform_pci_power_manageable(struct pci_dev *dev)
590{
591 return pci_platform_pm ? pci_platform_pm->is_manageable(dev) : false;
592}
593
594static inline int platform_pci_set_power_state(struct pci_dev *dev,
595 pci_power_t t)
596{
597 return pci_platform_pm ? pci_platform_pm->set_state(dev, t) : -ENOSYS;
598}
599
600static inline pci_power_t platform_pci_get_power_state(struct pci_dev *dev)
601{
602 return pci_platform_pm ? pci_platform_pm->get_state(dev) : PCI_UNKNOWN;
603}
604
605static inline pci_power_t platform_pci_choose_state(struct pci_dev *dev)
606{
607 return pci_platform_pm ?
608 pci_platform_pm->choose_state(dev) : PCI_POWER_ERROR;
609}
610
611static inline int platform_pci_set_wakeup(struct pci_dev *dev, bool enable)
612{
613 return pci_platform_pm ?
614 pci_platform_pm->set_wakeup(dev, enable) : -ENODEV;
615}
616
617static inline bool platform_pci_need_resume(struct pci_dev *dev)
618{
619 return pci_platform_pm ? pci_platform_pm->need_resume(dev) : false;
620}
621
622/**
623 * pci_raw_set_power_state - Use PCI PM registers to set the power state of
624 * given PCI device
625 * @dev: PCI device to handle.
626 * @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
627 *
628 * RETURN VALUE:
629 * -EINVAL if the requested state is invalid.
630 * -EIO if device does not support PCI PM or its PM capabilities register has a
631 * wrong version, or device doesn't support the requested state.
632 * 0 if device already is in the requested state.
633 * 0 if device's power state has been successfully changed.
634 */
635static int pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
636{
637 u16 pmcsr;
638 bool need_restore = false;
639
640 /* Check if we're already there */
641 if (dev->current_state == state)
642 return 0;
643
644 if (!dev->pm_cap)
645 return -EIO;
646
647 if (state < PCI_D0 || state > PCI_D3hot)
648 return -EINVAL;
649
650 /* Validate current state:
651 * Can enter D0 from any state, but if we can only go deeper
652 * to sleep if we're already in a low power state
653 */
654 if (state != PCI_D0 && dev->current_state <= PCI_D3cold
655 && dev->current_state > state) {
656 pci_err(dev, "invalid power transition (from state %d to %d)\n",
657 dev->current_state, state);
658 return -EINVAL;
659 }
660
661 /* check if this device supports the desired state */
662 if ((state == PCI_D1 && !dev->d1_support)
663 || (state == PCI_D2 && !dev->d2_support))
664 return -EIO;
665
666 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
667
668 /* If we're (effectively) in D3, force entire word to 0.
669 * This doesn't affect PME_Status, disables PME_En, and
670 * sets PowerState to 0.
671 */
672 switch (dev->current_state) {
673 case PCI_D0:
674 case PCI_D1:
675 case PCI_D2:
676 pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
677 pmcsr |= state;
678 break;
679 case PCI_D3hot:
680 case PCI_D3cold:
681 case PCI_UNKNOWN: /* Boot-up */
682 if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot
683 && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))
684 need_restore = true;
685 /* Fall-through: force to D0 */
686 default:
687 pmcsr = 0;
688 break;
689 }
690
691 /* enter specified state */
692 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
693
694 /* Mandatory power management transition delays */
695 /* see PCI PM 1.1 5.6.1 table 18 */
696 if (state == PCI_D3hot || dev->current_state == PCI_D3hot)
697 pci_dev_d3_sleep(dev);
698 else if (state == PCI_D2 || dev->current_state == PCI_D2)
699 udelay(PCI_PM_D2_DELAY);
700
701 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
702 dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
703 if (dev->current_state != state && printk_ratelimit())
704 pci_info(dev, "Refused to change power state, currently in D%d\n",
705 dev->current_state);
706
707 /*
708 * According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT
709 * INTERFACE SPECIFICATION, REV. 1.2", a device transitioning
710 * from D3hot to D0 _may_ perform an internal reset, thereby
711 * going to "D0 Uninitialized" rather than "D0 Initialized".
712 * For example, at least some versions of the 3c905B and the
713 * 3c556B exhibit this behaviour.
714 *
715 * At least some laptop BIOSen (e.g. the Thinkpad T21) leave
716 * devices in a D3hot state at boot. Consequently, we need to
717 * restore at least the BARs so that the device will be
718 * accessible to its driver.
719 */
720 if (need_restore)
721 pci_restore_bars(dev);
722
723 if (dev->bus->self)
724 pcie_aspm_pm_state_change(dev->bus->self);
725
726 return 0;
727}
728
729/**
730 * pci_update_current_state - Read power state of given device and cache it
731 * @dev: PCI device to handle.
732 * @state: State to cache in case the device doesn't have the PM capability
733 *
734 * The power state is read from the PMCSR register, which however is
735 * inaccessible in D3cold. The platform firmware is therefore queried first
736 * to detect accessibility of the register. In case the platform firmware
737 * reports an incorrect state or the device isn't power manageable by the
738 * platform at all, we try to detect D3cold by testing accessibility of the
739 * vendor ID in config space.
740 */
741void pci_update_current_state(struct pci_dev *dev, pci_power_t state)
742{
743 if (platform_pci_get_power_state(dev) == PCI_D3cold ||
744 !pci_device_is_present(dev)) {
745 dev->current_state = PCI_D3cold;
746 } else if (dev->pm_cap) {
747 u16 pmcsr;
748
749 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
750 dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
751 } else {
752 dev->current_state = state;
753 }
754}
755
756/**
757 * pci_power_up - Put the given device into D0 forcibly
758 * @dev: PCI device to power up
759 */
760void pci_power_up(struct pci_dev *dev)
761{
762 if (platform_pci_power_manageable(dev))
763 platform_pci_set_power_state(dev, PCI_D0);
764
765 pci_raw_set_power_state(dev, PCI_D0);
766 pci_update_current_state(dev, PCI_D0);
767}
768
769/**
770 * pci_platform_power_transition - Use platform to change device power state
771 * @dev: PCI device to handle.
772 * @state: State to put the device into.
773 */
774static int pci_platform_power_transition(struct pci_dev *dev, pci_power_t state)
775{
776 int error;
777
778 if (platform_pci_power_manageable(dev)) {
779 error = platform_pci_set_power_state(dev, state);
780 if (!error)
781 pci_update_current_state(dev, state);
782 } else
783 error = -ENODEV;
784
785 if (error && !dev->pm_cap) /* Fall back to PCI_D0 */
786 dev->current_state = PCI_D0;
787
788 return error;
789}
790
791/**
792 * pci_wakeup - Wake up a PCI device
793 * @pci_dev: Device to handle.
794 * @ign: ignored parameter
795 */
796static int pci_wakeup(struct pci_dev *pci_dev, void *ign)
797{
798 pci_wakeup_event(pci_dev);
799 pm_request_resume(&pci_dev->dev);
800 return 0;
801}
802
803/**
804 * pci_wakeup_bus - Walk given bus and wake up devices on it
805 * @bus: Top bus of the subtree to walk.
806 */
807void pci_wakeup_bus(struct pci_bus *bus)
808{
809 if (bus)
810 pci_walk_bus(bus, pci_wakeup, NULL);
811}
812
813/**
814 * __pci_start_power_transition - Start power transition of a PCI device
815 * @dev: PCI device to handle.
816 * @state: State to put the device into.
817 */
818static void __pci_start_power_transition(struct pci_dev *dev, pci_power_t state)
819{
820 if (state == PCI_D0) {
821 pci_platform_power_transition(dev, PCI_D0);
822 /*
823 * Mandatory power management transition delays, see
824 * PCI Express Base Specification Revision 2.0 Section
825 * 6.6.1: Conventional Reset. Do not delay for
826 * devices powered on/off by corresponding bridge,
827 * because have already delayed for the bridge.
828 */
829 if (dev->runtime_d3cold) {
830 if (dev->d3cold_delay)
831 msleep(dev->d3cold_delay);
832 /*
833 * When powering on a bridge from D3cold, the
834 * whole hierarchy may be powered on into
835 * D0uninitialized state, resume them to give
836 * them a chance to suspend again
837 */
838 pci_wakeup_bus(dev->subordinate);
839 }
840 }
841}
842
843/**
844 * __pci_dev_set_current_state - Set current state of a PCI device
845 * @dev: Device to handle
846 * @data: pointer to state to be set
847 */
848static int __pci_dev_set_current_state(struct pci_dev *dev, void *data)
849{
850 pci_power_t state = *(pci_power_t *)data;
851
852 dev->current_state = state;
853 return 0;
854}
855
856/**
857 * pci_bus_set_current_state - Walk given bus and set current state of devices
858 * @bus: Top bus of the subtree to walk.
859 * @state: state to be set
860 */
861void pci_bus_set_current_state(struct pci_bus *bus, pci_power_t state)
862{
863 if (bus)
864 pci_walk_bus(bus, __pci_dev_set_current_state, &state);
865}
866
867/**
868 * __pci_complete_power_transition - Complete power transition of a PCI device
869 * @dev: PCI device to handle.
870 * @state: State to put the device into.
871 *
872 * This function should not be called directly by device drivers.
873 */
874int __pci_complete_power_transition(struct pci_dev *dev, pci_power_t state)
875{
876 int ret;
877
878 if (state <= PCI_D0)
879 return -EINVAL;
880 ret = pci_platform_power_transition(dev, state);
881 /* Power off the bridge may power off the whole hierarchy */
882 if (!ret && state == PCI_D3cold)
883 pci_bus_set_current_state(dev->subordinate, PCI_D3cold);
884 return ret;
885}
886EXPORT_SYMBOL_GPL(__pci_complete_power_transition);
887
888/**
889 * pci_set_power_state - Set the power state of a PCI device
890 * @dev: PCI device to handle.
891 * @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
892 *
893 * Transition a device to a new power state, using the platform firmware and/or
894 * the device's PCI PM registers.
895 *
896 * RETURN VALUE:
897 * -EINVAL if the requested state is invalid.
898 * -EIO if device does not support PCI PM or its PM capabilities register has a
899 * wrong version, or device doesn't support the requested state.
900 * 0 if the transition is to D1 or D2 but D1 and D2 are not supported.
901 * 0 if device already is in the requested state.
902 * 0 if the transition is to D3 but D3 is not supported.
903 * 0 if device's power state has been successfully changed.
904 */
905int pci_set_power_state(struct pci_dev *dev, pci_power_t state)
906{
907 int error;
908
909 /* bound the state we're entering */
910 if (state > PCI_D3cold)
911 state = PCI_D3cold;
912 else if (state < PCI_D0)
913 state = PCI_D0;
914 else if ((state == PCI_D1 || state == PCI_D2) && pci_no_d1d2(dev))
915 /*
916 * If the device or the parent bridge do not support PCI PM,
917 * ignore the request if we're doing anything other than putting
918 * it into D0 (which would only happen on boot).
919 */
920 return 0;
921
922 /* Check if we're already there */
923 if (dev->current_state == state)
924 return 0;
925
926 __pci_start_power_transition(dev, state);
927
928 /* This device is quirked not to be put into D3, so
929 don't put it in D3 */
930 if (state >= PCI_D3hot && (dev->dev_flags & PCI_DEV_FLAGS_NO_D3))
931 return 0;
932
933 /*
934 * To put device in D3cold, we put device into D3hot in native
935 * way, then put device into D3cold with platform ops
936 */
937 error = pci_raw_set_power_state(dev, state > PCI_D3hot ?
938 PCI_D3hot : state);
939
940 if (!__pci_complete_power_transition(dev, state))
941 error = 0;
942
943 return error;
944}
945EXPORT_SYMBOL(pci_set_power_state);
946
947/**
948 * pci_choose_state - Choose the power state of a PCI device
949 * @dev: PCI device to be suspended
950 * @state: target sleep state for the whole system. This is the value
951 * that is passed to suspend() function.
952 *
953 * Returns PCI power state suitable for given device and given system
954 * message.
955 */
956
957pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state)
958{
959 pci_power_t ret;
960
961 if (!dev->pm_cap)
962 return PCI_D0;
963
964 ret = platform_pci_choose_state(dev);
965 if (ret != PCI_POWER_ERROR)
966 return ret;
967
968 switch (state.event) {
969 case PM_EVENT_ON:
970 return PCI_D0;
971 case PM_EVENT_FREEZE:
972 case PM_EVENT_PRETHAW:
973 /* REVISIT both freeze and pre-thaw "should" use D0 */
974 case PM_EVENT_SUSPEND:
975 case PM_EVENT_HIBERNATE:
976 return PCI_D3hot;
977 default:
978 pci_info(dev, "unrecognized suspend event %d\n",
979 state.event);
980 BUG();
981 }
982 return PCI_D0;
983}
984EXPORT_SYMBOL(pci_choose_state);
985
986#define PCI_EXP_SAVE_REGS 7
987
988static struct pci_cap_saved_state *_pci_find_saved_cap(struct pci_dev *pci_dev,
989 u16 cap, bool extended)
990{
991 struct pci_cap_saved_state *tmp;
992
993 hlist_for_each_entry(tmp, &pci_dev->saved_cap_space, next) {
994 if (tmp->cap.cap_extended == extended && tmp->cap.cap_nr == cap)
995 return tmp;
996 }
997 return NULL;
998}
999
1000struct pci_cap_saved_state *pci_find_saved_cap(struct pci_dev *dev, char cap)
1001{
1002 return _pci_find_saved_cap(dev, cap, false);
1003}
1004
1005struct pci_cap_saved_state *pci_find_saved_ext_cap(struct pci_dev *dev, u16 cap)
1006{
1007 return _pci_find_saved_cap(dev, cap, true);
1008}
1009
1010static int pci_save_pcie_state(struct pci_dev *dev)
1011{
1012 int i = 0;
1013 struct pci_cap_saved_state *save_state;
1014 u16 *cap;
1015
1016 if (!pci_is_pcie(dev))
1017 return 0;
1018
1019 save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
1020 if (!save_state) {
1021 pci_err(dev, "buffer not found in %s\n", __func__);
1022 return -ENOMEM;
1023 }
1024
1025 cap = (u16 *)&save_state->cap.data[0];
1026 pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &cap[i++]);
1027 pcie_capability_read_word(dev, PCI_EXP_LNKCTL, &cap[i++]);
1028 pcie_capability_read_word(dev, PCI_EXP_SLTCTL, &cap[i++]);
1029 pcie_capability_read_word(dev, PCI_EXP_RTCTL, &cap[i++]);
1030 pcie_capability_read_word(dev, PCI_EXP_DEVCTL2, &cap[i++]);
1031 pcie_capability_read_word(dev, PCI_EXP_LNKCTL2, &cap[i++]);
1032 pcie_capability_read_word(dev, PCI_EXP_SLTCTL2, &cap[i++]);
1033
1034 return 0;
1035}
1036
1037static void pci_restore_pcie_state(struct pci_dev *dev)
1038{
1039 int i = 0;
1040 struct pci_cap_saved_state *save_state;
1041 u16 *cap;
1042
1043 save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
1044 if (!save_state)
1045 return;
1046
1047 cap = (u16 *)&save_state->cap.data[0];
1048 pcie_capability_write_word(dev, PCI_EXP_DEVCTL, cap[i++]);
1049 pcie_capability_write_word(dev, PCI_EXP_LNKCTL, cap[i++]);
1050 pcie_capability_write_word(dev, PCI_EXP_SLTCTL, cap[i++]);
1051 pcie_capability_write_word(dev, PCI_EXP_RTCTL, cap[i++]);
1052 pcie_capability_write_word(dev, PCI_EXP_DEVCTL2, cap[i++]);
1053 pcie_capability_write_word(dev, PCI_EXP_LNKCTL2, cap[i++]);
1054 pcie_capability_write_word(dev, PCI_EXP_SLTCTL2, cap[i++]);
1055}
1056
1057
1058static int pci_save_pcix_state(struct pci_dev *dev)
1059{
1060 int pos;
1061 struct pci_cap_saved_state *save_state;
1062
1063 pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
1064 if (!pos)
1065 return 0;
1066
1067 save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX);
1068 if (!save_state) {
1069 pci_err(dev, "buffer not found in %s\n", __func__);
1070 return -ENOMEM;
1071 }
1072
1073 pci_read_config_word(dev, pos + PCI_X_CMD,
1074 (u16 *)save_state->cap.data);
1075
1076 return 0;
1077}
1078
1079static void pci_restore_pcix_state(struct pci_dev *dev)
1080{
1081 int i = 0, pos;
1082 struct pci_cap_saved_state *save_state;
1083 u16 *cap;
1084
1085 save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX);
1086 pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
1087 if (!save_state || !pos)
1088 return;
1089 cap = (u16 *)&save_state->cap.data[0];
1090
1091 pci_write_config_word(dev, pos + PCI_X_CMD, cap[i++]);
1092}
1093
1094
1095/**
1096 * pci_save_state - save the PCI configuration space of a device before suspending
1097 * @dev: - PCI device that we're dealing with
1098 */
1099int pci_save_state(struct pci_dev *dev)
1100{
1101 int i;
1102 /* XXX: 100% dword access ok here? */
1103 for (i = 0; i < 16; i++)
1104 pci_read_config_dword(dev, i * 4, &dev->saved_config_space[i]);
1105 dev->state_saved = true;
1106
1107 i = pci_save_pcie_state(dev);
1108 if (i != 0)
1109 return i;
1110
1111 i = pci_save_pcix_state(dev);
1112 if (i != 0)
1113 return i;
1114
1115 return pci_save_vc_state(dev);
1116}
1117EXPORT_SYMBOL(pci_save_state);
1118
1119static void pci_restore_config_dword(struct pci_dev *pdev, int offset,
1120 u32 saved_val, int retry)
1121{
1122 u32 val;
1123
1124 pci_read_config_dword(pdev, offset, &val);
1125 if (val == saved_val)
1126 return;
1127
1128 for (;;) {
1129 pci_dbg(pdev, "restoring config space at offset %#x (was %#x, writing %#x)\n",
1130 offset, val, saved_val);
1131 pci_write_config_dword(pdev, offset, saved_val);
1132 if (retry-- <= 0)
1133 return;
1134
1135 pci_read_config_dword(pdev, offset, &val);
1136 if (val == saved_val)
1137 return;
1138
1139 mdelay(1);
1140 }
1141}
1142
1143static void pci_restore_config_space_range(struct pci_dev *pdev,
1144 int start, int end, int retry)
1145{
1146 int index;
1147
1148 for (index = end; index >= start; index--)
1149 pci_restore_config_dword(pdev, 4 * index,
1150 pdev->saved_config_space[index],
1151 retry);
1152}
1153
1154static void pci_restore_config_space(struct pci_dev *pdev)
1155{
1156 if (pdev->hdr_type == PCI_HEADER_TYPE_NORMAL) {
1157 pci_restore_config_space_range(pdev, 10, 15, 0);
1158 /* Restore BARs before the command register. */
1159 pci_restore_config_space_range(pdev, 4, 9, 10);
1160 pci_restore_config_space_range(pdev, 0, 3, 0);
1161 } else {
1162 pci_restore_config_space_range(pdev, 0, 15, 0);
1163 }
1164}
1165
1166/**
1167 * pci_restore_state - Restore the saved state of a PCI device
1168 * @dev: - PCI device that we're dealing with
1169 */
1170void pci_restore_state(struct pci_dev *dev)
1171{
1172 if (!dev->state_saved)
1173 return;
1174
1175 /* PCI Express register must be restored first */
1176 pci_restore_pcie_state(dev);
1177 pci_restore_pasid_state(dev);
1178 pci_restore_pri_state(dev);
1179 pci_restore_ats_state(dev);
1180 pci_restore_vc_state(dev);
1181
1182 pci_cleanup_aer_error_status_regs(dev);
1183
1184 pci_restore_config_space(dev);
1185
1186 pci_restore_pcix_state(dev);
1187 pci_restore_msi_state(dev);
1188
1189 /* Restore ACS and IOV configuration state */
1190 pci_enable_acs(dev);
1191 pci_restore_iov_state(dev);
1192
1193 dev->state_saved = false;
1194}
1195EXPORT_SYMBOL(pci_restore_state);
1196
1197struct pci_saved_state {
1198 u32 config_space[16];
1199 struct pci_cap_saved_data cap[0];
1200};
1201
1202/**
1203 * pci_store_saved_state - Allocate and return an opaque struct containing
1204 * the device saved state.
1205 * @dev: PCI device that we're dealing with
1206 *
1207 * Return NULL if no state or error.
1208 */
1209struct pci_saved_state *pci_store_saved_state(struct pci_dev *dev)
1210{
1211 struct pci_saved_state *state;
1212 struct pci_cap_saved_state *tmp;
1213 struct pci_cap_saved_data *cap;
1214 size_t size;
1215
1216 if (!dev->state_saved)
1217 return NULL;
1218
1219 size = sizeof(*state) + sizeof(struct pci_cap_saved_data);
1220
1221 hlist_for_each_entry(tmp, &dev->saved_cap_space, next)
1222 size += sizeof(struct pci_cap_saved_data) + tmp->cap.size;
1223
1224 state = kzalloc(size, GFP_KERNEL);
1225 if (!state)
1226 return NULL;
1227
1228 memcpy(state->config_space, dev->saved_config_space,
1229 sizeof(state->config_space));
1230
1231 cap = state->cap;
1232 hlist_for_each_entry(tmp, &dev->saved_cap_space, next) {
1233 size_t len = sizeof(struct pci_cap_saved_data) + tmp->cap.size;
1234 memcpy(cap, &tmp->cap, len);
1235 cap = (struct pci_cap_saved_data *)((u8 *)cap + len);
1236 }
1237 /* Empty cap_save terminates list */
1238
1239 return state;
1240}
1241EXPORT_SYMBOL_GPL(pci_store_saved_state);
1242
1243/**
1244 * pci_load_saved_state - Reload the provided save state into struct pci_dev.
1245 * @dev: PCI device that we're dealing with
1246 * @state: Saved state returned from pci_store_saved_state()
1247 */
1248int pci_load_saved_state(struct pci_dev *dev,
1249 struct pci_saved_state *state)
1250{
1251 struct pci_cap_saved_data *cap;
1252
1253 dev->state_saved = false;
1254
1255 if (!state)
1256 return 0;
1257
1258 memcpy(dev->saved_config_space, state->config_space,
1259 sizeof(state->config_space));
1260
1261 cap = state->cap;
1262 while (cap->size) {
1263 struct pci_cap_saved_state *tmp;
1264
1265 tmp = _pci_find_saved_cap(dev, cap->cap_nr, cap->cap_extended);
1266 if (!tmp || tmp->cap.size != cap->size)
1267 return -EINVAL;
1268
1269 memcpy(tmp->cap.data, cap->data, tmp->cap.size);
1270 cap = (struct pci_cap_saved_data *)((u8 *)cap +
1271 sizeof(struct pci_cap_saved_data) + cap->size);
1272 }
1273
1274 dev->state_saved = true;
1275 return 0;
1276}
1277EXPORT_SYMBOL_GPL(pci_load_saved_state);
1278
1279/**
1280 * pci_load_and_free_saved_state - Reload the save state pointed to by state,
1281 * and free the memory allocated for it.
1282 * @dev: PCI device that we're dealing with
1283 * @state: Pointer to saved state returned from pci_store_saved_state()
1284 */
1285int pci_load_and_free_saved_state(struct pci_dev *dev,
1286 struct pci_saved_state **state)
1287{
1288 int ret = pci_load_saved_state(dev, *state);
1289 kfree(*state);
1290 *state = NULL;
1291 return ret;
1292}
1293EXPORT_SYMBOL_GPL(pci_load_and_free_saved_state);
1294
1295int __weak pcibios_enable_device(struct pci_dev *dev, int bars)
1296{
1297 return pci_enable_resources(dev, bars);
1298}
1299
1300static int do_pci_enable_device(struct pci_dev *dev, int bars)
1301{
1302 int err;
1303 struct pci_dev *bridge;
1304 u16 cmd;
1305 u8 pin;
1306
1307 err = pci_set_power_state(dev, PCI_D0);
1308 if (err < 0 && err != -EIO)
1309 return err;
1310
1311 bridge = pci_upstream_bridge(dev);
1312 if (bridge)
1313 pcie_aspm_powersave_config_link(bridge);
1314
1315 err = pcibios_enable_device(dev, bars);
1316 if (err < 0)
1317 return err;
1318 pci_fixup_device(pci_fixup_enable, dev);
1319
1320 if (dev->msi_enabled || dev->msix_enabled)
1321 return 0;
1322
1323 pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
1324 if (pin) {
1325 pci_read_config_word(dev, PCI_COMMAND, &cmd);
1326 if (cmd & PCI_COMMAND_INTX_DISABLE)
1327 pci_write_config_word(dev, PCI_COMMAND,
1328 cmd & ~PCI_COMMAND_INTX_DISABLE);
1329 }
1330
1331 return 0;
1332}
1333
1334/**
1335 * pci_reenable_device - Resume abandoned device
1336 * @dev: PCI device to be resumed
1337 *
1338 * Note this function is a backend of pci_default_resume and is not supposed
1339 * to be called by normal code, write proper resume handler and use it instead.
1340 */
1341int pci_reenable_device(struct pci_dev *dev)
1342{
1343 if (pci_is_enabled(dev))
1344 return do_pci_enable_device(dev, (1 << PCI_NUM_RESOURCES) - 1);
1345 return 0;
1346}
1347EXPORT_SYMBOL(pci_reenable_device);
1348
1349static void pci_enable_bridge(struct pci_dev *dev)
1350{
1351 struct pci_dev *bridge;
1352 int retval;
1353
1354 bridge = pci_upstream_bridge(dev);
1355 if (bridge)
1356 pci_enable_bridge(bridge);
1357
1358 if (pci_is_enabled(dev)) {
1359 if (!dev->is_busmaster)
1360 pci_set_master(dev);
1361 return;
1362 }
1363
1364 retval = pci_enable_device(dev);
1365 if (retval)
1366 pci_err(dev, "Error enabling bridge (%d), continuing\n",
1367 retval);
1368 pci_set_master(dev);
1369}
1370
1371static int pci_enable_device_flags(struct pci_dev *dev, unsigned long flags)
1372{
1373 struct pci_dev *bridge;
1374 int err;
1375 int i, bars = 0;
1376
1377 /*
1378 * Power state could be unknown at this point, either due to a fresh
1379 * boot or a device removal call. So get the current power state
1380 * so that things like MSI message writing will behave as expected
1381 * (e.g. if the device really is in D0 at enable time).
1382 */
1383 if (dev->pm_cap) {
1384 u16 pmcsr;
1385 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
1386 dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
1387 }
1388
1389 if (atomic_inc_return(&dev->enable_cnt) > 1)
1390 return 0; /* already enabled */
1391
1392 bridge = pci_upstream_bridge(dev);
1393 if (bridge)
1394 pci_enable_bridge(bridge);
1395
1396 /* only skip sriov related */
1397 for (i = 0; i <= PCI_ROM_RESOURCE; i++)
1398 if (dev->resource[i].flags & flags)
1399 bars |= (1 << i);
1400 for (i = PCI_BRIDGE_RESOURCES; i < DEVICE_COUNT_RESOURCE; i++)
1401 if (dev->resource[i].flags & flags)
1402 bars |= (1 << i);
1403
1404 err = do_pci_enable_device(dev, bars);
1405 if (err < 0)
1406 atomic_dec(&dev->enable_cnt);
1407 return err;
1408}
1409
1410/**
1411 * pci_enable_device_io - Initialize a device for use with IO space
1412 * @dev: PCI device to be initialized
1413 *
1414 * Initialize device before it's used by a driver. Ask low-level code
1415 * to enable I/O resources. Wake up the device if it was suspended.
1416 * Beware, this function can fail.
1417 */
1418int pci_enable_device_io(struct pci_dev *dev)
1419{
1420 return pci_enable_device_flags(dev, IORESOURCE_IO);
1421}
1422EXPORT_SYMBOL(pci_enable_device_io);
1423
1424/**
1425 * pci_enable_device_mem - Initialize a device for use with Memory space
1426 * @dev: PCI device to be initialized
1427 *
1428 * Initialize device before it's used by a driver. Ask low-level code
1429 * to enable Memory resources. Wake up the device if it was suspended.
1430 * Beware, this function can fail.
1431 */
1432int pci_enable_device_mem(struct pci_dev *dev)
1433{
1434 return pci_enable_device_flags(dev, IORESOURCE_MEM);
1435}
1436EXPORT_SYMBOL(pci_enable_device_mem);
1437
1438/**
1439 * pci_enable_device - Initialize device before it's used by a driver.
1440 * @dev: PCI device to be initialized
1441 *
1442 * Initialize device before it's used by a driver. Ask low-level code
1443 * to enable I/O and memory. Wake up the device if it was suspended.
1444 * Beware, this function can fail.
1445 *
1446 * Note we don't actually enable the device many times if we call
1447 * this function repeatedly (we just increment the count).
1448 */
1449int pci_enable_device(struct pci_dev *dev)
1450{
1451 return pci_enable_device_flags(dev, IORESOURCE_MEM | IORESOURCE_IO);
1452}
1453EXPORT_SYMBOL(pci_enable_device);
1454
1455/*
1456 * Managed PCI resources. This manages device on/off, intx/msi/msix
1457 * on/off and BAR regions. pci_dev itself records msi/msix status, so
1458 * there's no need to track it separately. pci_devres is initialized
1459 * when a device is enabled using managed PCI device enable interface.
1460 */
1461struct pci_devres {
1462 unsigned int enabled:1;
1463 unsigned int pinned:1;
1464 unsigned int orig_intx:1;
1465 unsigned int restore_intx:1;
1466 unsigned int mwi:1;
1467 u32 region_mask;
1468};
1469
1470static void pcim_release(struct device *gendev, void *res)
1471{
1472 struct pci_dev *dev = to_pci_dev(gendev);
1473 struct pci_devres *this = res;
1474 int i;
1475
1476 if (dev->msi_enabled)
1477 pci_disable_msi(dev);
1478 if (dev->msix_enabled)
1479 pci_disable_msix(dev);
1480
1481 for (i = 0; i < DEVICE_COUNT_RESOURCE; i++)
1482 if (this->region_mask & (1 << i))
1483 pci_release_region(dev, i);
1484
1485 if (this->mwi)
1486 pci_clear_mwi(dev);
1487
1488 if (this->restore_intx)
1489 pci_intx(dev, this->orig_intx);
1490
1491 if (this->enabled && !this->pinned)
1492 pci_disable_device(dev);
1493}
1494
1495static struct pci_devres *get_pci_dr(struct pci_dev *pdev)
1496{
1497 struct pci_devres *dr, *new_dr;
1498
1499 dr = devres_find(&pdev->dev, pcim_release, NULL, NULL);
1500 if (dr)
1501 return dr;
1502
1503 new_dr = devres_alloc(pcim_release, sizeof(*new_dr), GFP_KERNEL);
1504 if (!new_dr)
1505 return NULL;
1506 return devres_get(&pdev->dev, new_dr, NULL, NULL);
1507}
1508
1509static struct pci_devres *find_pci_dr(struct pci_dev *pdev)
1510{
1511 if (pci_is_managed(pdev))
1512 return devres_find(&pdev->dev, pcim_release, NULL, NULL);
1513 return NULL;
1514}
1515
1516/**
1517 * pcim_enable_device - Managed pci_enable_device()
1518 * @pdev: PCI device to be initialized
1519 *
1520 * Managed pci_enable_device().
1521 */
1522int pcim_enable_device(struct pci_dev *pdev)
1523{
1524 struct pci_devres *dr;
1525 int rc;
1526
1527 dr = get_pci_dr(pdev);
1528 if (unlikely(!dr))
1529 return -ENOMEM;
1530 if (dr->enabled)
1531 return 0;
1532
1533 rc = pci_enable_device(pdev);
1534 if (!rc) {
1535 pdev->is_managed = 1;
1536 dr->enabled = 1;
1537 }
1538 return rc;
1539}
1540EXPORT_SYMBOL(pcim_enable_device);
1541
1542/**
1543 * pcim_pin_device - Pin managed PCI device
1544 * @pdev: PCI device to pin
1545 *
1546 * Pin managed PCI device @pdev. Pinned device won't be disabled on
1547 * driver detach. @pdev must have been enabled with
1548 * pcim_enable_device().
1549 */
1550void pcim_pin_device(struct pci_dev *pdev)
1551{
1552 struct pci_devres *dr;
1553
1554 dr = find_pci_dr(pdev);
1555 WARN_ON(!dr || !dr->enabled);
1556 if (dr)
1557 dr->pinned = 1;
1558}
1559EXPORT_SYMBOL(pcim_pin_device);
1560
1561/*
1562 * pcibios_add_device - provide arch specific hooks when adding device dev
1563 * @dev: the PCI device being added
1564 *
1565 * Permits the platform to provide architecture specific functionality when
1566 * devices are added. This is the default implementation. Architecture
1567 * implementations can override this.
1568 */
1569int __weak pcibios_add_device(struct pci_dev *dev)
1570{
1571 return 0;
1572}
1573
1574/**
1575 * pcibios_release_device - provide arch specific hooks when releasing device dev
1576 * @dev: the PCI device being released
1577 *
1578 * Permits the platform to provide architecture specific functionality when
1579 * devices are released. This is the default implementation. Architecture
1580 * implementations can override this.
1581 */
1582void __weak pcibios_release_device(struct pci_dev *dev) {}
1583
1584/**
1585 * pcibios_disable_device - disable arch specific PCI resources for device dev
1586 * @dev: the PCI device to disable
1587 *
1588 * Disables architecture specific PCI resources for the device. This
1589 * is the default implementation. Architecture implementations can
1590 * override this.
1591 */
1592void __weak pcibios_disable_device(struct pci_dev *dev) {}
1593
1594/**
1595 * pcibios_penalize_isa_irq - penalize an ISA IRQ
1596 * @irq: ISA IRQ to penalize
1597 * @active: IRQ active or not
1598 *
1599 * Permits the platform to provide architecture-specific functionality when
1600 * penalizing ISA IRQs. This is the default implementation. Architecture
1601 * implementations can override this.
1602 */
1603void __weak pcibios_penalize_isa_irq(int irq, int active) {}
1604
1605static void do_pci_disable_device(struct pci_dev *dev)
1606{
1607 u16 pci_command;
1608
1609 pci_read_config_word(dev, PCI_COMMAND, &pci_command);
1610 if (pci_command & PCI_COMMAND_MASTER) {
1611 pci_command &= ~PCI_COMMAND_MASTER;
1612 pci_write_config_word(dev, PCI_COMMAND, pci_command);
1613 }
1614
1615 pcibios_disable_device(dev);
1616}
1617
1618/**
1619 * pci_disable_enabled_device - Disable device without updating enable_cnt
1620 * @dev: PCI device to disable
1621 *
1622 * NOTE: This function is a backend of PCI power management routines and is
1623 * not supposed to be called drivers.
1624 */
1625void pci_disable_enabled_device(struct pci_dev *dev)
1626{
1627 if (pci_is_enabled(dev))
1628 do_pci_disable_device(dev);
1629}
1630
1631/**
1632 * pci_disable_device - Disable PCI device after use
1633 * @dev: PCI device to be disabled
1634 *
1635 * Signal to the system that the PCI device is not in use by the system
1636 * anymore. This only involves disabling PCI bus-mastering, if active.
1637 *
1638 * Note we don't actually disable the device until all callers of
1639 * pci_enable_device() have called pci_disable_device().
1640 */
1641void pci_disable_device(struct pci_dev *dev)
1642{
1643 struct pci_devres *dr;
1644
1645 dr = find_pci_dr(dev);
1646 if (dr)
1647 dr->enabled = 0;
1648
1649 dev_WARN_ONCE(&dev->dev, atomic_read(&dev->enable_cnt) <= 0,
1650 "disabling already-disabled device");
1651
1652 if (atomic_dec_return(&dev->enable_cnt) != 0)
1653 return;
1654
1655 do_pci_disable_device(dev);
1656
1657 dev->is_busmaster = 0;
1658}
1659EXPORT_SYMBOL(pci_disable_device);
1660
1661/**
1662 * pcibios_set_pcie_reset_state - set reset state for device dev
1663 * @dev: the PCIe device reset
1664 * @state: Reset state to enter into
1665 *
1666 *
1667 * Sets the PCIe reset state for the device. This is the default
1668 * implementation. Architecture implementations can override this.
1669 */
1670int __weak pcibios_set_pcie_reset_state(struct pci_dev *dev,
1671 enum pcie_reset_state state)
1672{
1673 return -EINVAL;
1674}
1675
1676/**
1677 * pci_set_pcie_reset_state - set reset state for device dev
1678 * @dev: the PCIe device reset
1679 * @state: Reset state to enter into
1680 *
1681 *
1682 * Sets the PCI reset state for the device.
1683 */
1684int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state)
1685{
1686 return pcibios_set_pcie_reset_state(dev, state);
1687}
1688EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state);
1689
1690/**
1691 * pcie_clear_root_pme_status - Clear root port PME interrupt status.
1692 * @dev: PCIe root port or event collector.
1693 */
1694void pcie_clear_root_pme_status(struct pci_dev *dev)
1695{
1696 pcie_capability_set_dword(dev, PCI_EXP_RTSTA, PCI_EXP_RTSTA_PME);
1697}
1698
1699/**
1700 * pci_check_pme_status - Check if given device has generated PME.
1701 * @dev: Device to check.
1702 *
1703 * Check the PME status of the device and if set, clear it and clear PME enable
1704 * (if set). Return 'true' if PME status and PME enable were both set or
1705 * 'false' otherwise.
1706 */
1707bool pci_check_pme_status(struct pci_dev *dev)
1708{
1709 int pmcsr_pos;
1710 u16 pmcsr;
1711 bool ret = false;
1712
1713 if (!dev->pm_cap)
1714 return false;
1715
1716 pmcsr_pos = dev->pm_cap + PCI_PM_CTRL;
1717 pci_read_config_word(dev, pmcsr_pos, &pmcsr);
1718 if (!(pmcsr & PCI_PM_CTRL_PME_STATUS))
1719 return false;
1720
1721 /* Clear PME status. */
1722 pmcsr |= PCI_PM_CTRL_PME_STATUS;
1723 if (pmcsr & PCI_PM_CTRL_PME_ENABLE) {
1724 /* Disable PME to avoid interrupt flood. */
1725 pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
1726 ret = true;
1727 }
1728
1729 pci_write_config_word(dev, pmcsr_pos, pmcsr);
1730
1731 return ret;
1732}
1733
1734/**
1735 * pci_pme_wakeup - Wake up a PCI device if its PME Status bit is set.
1736 * @dev: Device to handle.
1737 * @pme_poll_reset: Whether or not to reset the device's pme_poll flag.
1738 *
1739 * Check if @dev has generated PME and queue a resume request for it in that
1740 * case.
1741 */
1742static int pci_pme_wakeup(struct pci_dev *dev, void *pme_poll_reset)
1743{
1744 if (pme_poll_reset && dev->pme_poll)
1745 dev->pme_poll = false;
1746
1747 if (pci_check_pme_status(dev)) {
1748 pci_wakeup_event(dev);
1749 pm_request_resume(&dev->dev);
1750 }
1751 return 0;
1752}
1753
1754/**
1755 * pci_pme_wakeup_bus - Walk given bus and wake up devices on it, if necessary.
1756 * @bus: Top bus of the subtree to walk.
1757 */
1758void pci_pme_wakeup_bus(struct pci_bus *bus)
1759{
1760 if (bus)
1761 pci_walk_bus(bus, pci_pme_wakeup, (void *)true);
1762}
1763
1764
1765/**
1766 * pci_pme_capable - check the capability of PCI device to generate PME#
1767 * @dev: PCI device to handle.
1768 * @state: PCI state from which device will issue PME#.
1769 */
1770bool pci_pme_capable(struct pci_dev *dev, pci_power_t state)
1771{
1772 if (!dev->pm_cap)
1773 return false;
1774
1775 return !!(dev->pme_support & (1 << state));
1776}
1777EXPORT_SYMBOL(pci_pme_capable);
1778
1779static void pci_pme_list_scan(struct work_struct *work)
1780{
1781 struct pci_pme_device *pme_dev, *n;
1782
1783 mutex_lock(&pci_pme_list_mutex);
1784 list_for_each_entry_safe(pme_dev, n, &pci_pme_list, list) {
1785 if (pme_dev->dev->pme_poll) {
1786 struct pci_dev *bridge;
1787
1788 bridge = pme_dev->dev->bus->self;
1789 /*
1790 * If bridge is in low power state, the
1791 * configuration space of subordinate devices
1792 * may be not accessible
1793 */
1794 if (bridge && bridge->current_state != PCI_D0)
1795 continue;
1796 pci_pme_wakeup(pme_dev->dev, NULL);
1797 } else {
1798 list_del(&pme_dev->list);
1799 kfree(pme_dev);
1800 }
1801 }
1802 if (!list_empty(&pci_pme_list))
1803 queue_delayed_work(system_freezable_wq, &pci_pme_work,
1804 msecs_to_jiffies(PME_TIMEOUT));
1805 mutex_unlock(&pci_pme_list_mutex);
1806}
1807
1808static void __pci_pme_active(struct pci_dev *dev, bool enable)
1809{
1810 u16 pmcsr;
1811
1812 if (!dev->pme_support)
1813 return;
1814
1815 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
1816 /* Clear PME_Status by writing 1 to it and enable PME# */
1817 pmcsr |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE;
1818 if (!enable)
1819 pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
1820
1821 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
1822}
1823
1824/**
1825 * pci_pme_restore - Restore PME configuration after config space restore.
1826 * @dev: PCI device to update.
1827 */
1828void pci_pme_restore(struct pci_dev *dev)
1829{
1830 u16 pmcsr;
1831
1832 if (!dev->pme_support)
1833 return;
1834
1835 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
1836 if (dev->wakeup_prepared) {
1837 pmcsr |= PCI_PM_CTRL_PME_ENABLE;
1838 pmcsr &= ~PCI_PM_CTRL_PME_STATUS;
1839 } else {
1840 pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
1841 pmcsr |= PCI_PM_CTRL_PME_STATUS;
1842 }
1843 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
1844}
1845
1846/**
1847 * pci_pme_active - enable or disable PCI device's PME# function
1848 * @dev: PCI device to handle.
1849 * @enable: 'true' to enable PME# generation; 'false' to disable it.
1850 *
1851 * The caller must verify that the device is capable of generating PME# before
1852 * calling this function with @enable equal to 'true'.
1853 */
1854void pci_pme_active(struct pci_dev *dev, bool enable)
1855{
1856 __pci_pme_active(dev, enable);
1857
1858 /*
1859 * PCI (as opposed to PCIe) PME requires that the device have
1860 * its PME# line hooked up correctly. Not all hardware vendors
1861 * do this, so the PME never gets delivered and the device
1862 * remains asleep. The easiest way around this is to
1863 * periodically walk the list of suspended devices and check
1864 * whether any have their PME flag set. The assumption is that
1865 * we'll wake up often enough anyway that this won't be a huge
1866 * hit, and the power savings from the devices will still be a
1867 * win.
1868 *
1869 * Although PCIe uses in-band PME message instead of PME# line
1870 * to report PME, PME does not work for some PCIe devices in
1871 * reality. For example, there are devices that set their PME
1872 * status bits, but don't really bother to send a PME message;
1873 * there are PCI Express Root Ports that don't bother to
1874 * trigger interrupts when they receive PME messages from the
1875 * devices below. So PME poll is used for PCIe devices too.
1876 */
1877
1878 if (dev->pme_poll) {
1879 struct pci_pme_device *pme_dev;
1880 if (enable) {
1881 pme_dev = kmalloc(sizeof(struct pci_pme_device),
1882 GFP_KERNEL);
1883 if (!pme_dev) {
1884 pci_warn(dev, "can't enable PME#\n");
1885 return;
1886 }
1887 pme_dev->dev = dev;
1888 mutex_lock(&pci_pme_list_mutex);
1889 list_add(&pme_dev->list, &pci_pme_list);
1890 if (list_is_singular(&pci_pme_list))
1891 queue_delayed_work(system_freezable_wq,
1892 &pci_pme_work,
1893 msecs_to_jiffies(PME_TIMEOUT));
1894 mutex_unlock(&pci_pme_list_mutex);
1895 } else {
1896 mutex_lock(&pci_pme_list_mutex);
1897 list_for_each_entry(pme_dev, &pci_pme_list, list) {
1898 if (pme_dev->dev == dev) {
1899 list_del(&pme_dev->list);
1900 kfree(pme_dev);
1901 break;
1902 }
1903 }
1904 mutex_unlock(&pci_pme_list_mutex);
1905 }
1906 }
1907
1908 pci_dbg(dev, "PME# %s\n", enable ? "enabled" : "disabled");
1909}
1910EXPORT_SYMBOL(pci_pme_active);
1911
1912/**
1913 * __pci_enable_wake - enable PCI device as wakeup event source
1914 * @dev: PCI device affected
1915 * @state: PCI state from which device will issue wakeup events
1916 * @enable: True to enable event generation; false to disable
1917 *
1918 * This enables the device as a wakeup event source, or disables it.
1919 * When such events involves platform-specific hooks, those hooks are
1920 * called automatically by this routine.
1921 *
1922 * Devices with legacy power management (no standard PCI PM capabilities)
1923 * always require such platform hooks.
1924 *
1925 * RETURN VALUE:
1926 * 0 is returned on success
1927 * -EINVAL is returned if device is not supposed to wake up the system
1928 * Error code depending on the platform is returned if both the platform and
1929 * the native mechanism fail to enable the generation of wake-up events
1930 */
1931static int __pci_enable_wake(struct pci_dev *dev, pci_power_t state, bool enable)
1932{
1933 int ret = 0;
1934
1935 /*
1936 * Bridges can only signal wakeup on behalf of subordinate devices,
1937 * but that is set up elsewhere, so skip them.
1938 */
1939 if (pci_has_subordinate(dev))
1940 return 0;
1941
1942 /* Don't do the same thing twice in a row for one device. */
1943 if (!!enable == !!dev->wakeup_prepared)
1944 return 0;
1945
1946 /*
1947 * According to "PCI System Architecture" 4th ed. by Tom Shanley & Don
1948 * Anderson we should be doing PME# wake enable followed by ACPI wake
1949 * enable. To disable wake-up we call the platform first, for symmetry.
1950 */
1951
1952 if (enable) {
1953 int error;
1954
1955 if (pci_pme_capable(dev, state))
1956 pci_pme_active(dev, true);
1957 else
1958 ret = 1;
1959 error = platform_pci_set_wakeup(dev, true);
1960 if (ret)
1961 ret = error;
1962 if (!ret)
1963 dev->wakeup_prepared = true;
1964 } else {
1965 platform_pci_set_wakeup(dev, false);
1966 pci_pme_active(dev, false);
1967 dev->wakeup_prepared = false;
1968 }
1969
1970 return ret;
1971}
1972
1973/**
1974 * pci_enable_wake - change wakeup settings for a PCI device
1975 * @pci_dev: Target device
1976 * @state: PCI state from which device will issue wakeup events
1977 * @enable: Whether or not to enable event generation
1978 *
1979 * If @enable is set, check device_may_wakeup() for the device before calling
1980 * __pci_enable_wake() for it.
1981 */
1982int pci_enable_wake(struct pci_dev *pci_dev, pci_power_t state, bool enable)
1983{
1984 if (enable && !device_may_wakeup(&pci_dev->dev))
1985 return -EINVAL;
1986
1987 return __pci_enable_wake(pci_dev, state, enable);
1988}
1989EXPORT_SYMBOL(pci_enable_wake);
1990
1991/**
1992 * pci_wake_from_d3 - enable/disable device to wake up from D3_hot or D3_cold
1993 * @dev: PCI device to prepare
1994 * @enable: True to enable wake-up event generation; false to disable
1995 *
1996 * Many drivers want the device to wake up the system from D3_hot or D3_cold
1997 * and this function allows them to set that up cleanly - pci_enable_wake()
1998 * should not be called twice in a row to enable wake-up due to PCI PM vs ACPI
1999 * ordering constraints.
2000 *
2001 * This function only returns error code if the device is not allowed to wake
2002 * up the system from sleep or it is not capable of generating PME# from both
2003 * D3_hot and D3_cold and the platform is unable to enable wake-up power for it.
2004 */
2005int pci_wake_from_d3(struct pci_dev *dev, bool enable)
2006{
2007 return pci_pme_capable(dev, PCI_D3cold) ?
2008 pci_enable_wake(dev, PCI_D3cold, enable) :
2009 pci_enable_wake(dev, PCI_D3hot, enable);
2010}
2011EXPORT_SYMBOL(pci_wake_from_d3);
2012
2013/**
2014 * pci_target_state - find an appropriate low power state for a given PCI dev
2015 * @dev: PCI device
2016 * @wakeup: Whether or not wakeup functionality will be enabled for the device.
2017 *
2018 * Use underlying platform code to find a supported low power state for @dev.
2019 * If the platform can't manage @dev, return the deepest state from which it
2020 * can generate wake events, based on any available PME info.
2021 */
2022static pci_power_t pci_target_state(struct pci_dev *dev, bool wakeup)
2023{
2024 pci_power_t target_state = PCI_D3hot;
2025
2026 if (platform_pci_power_manageable(dev)) {
2027 /*
2028 * Call the platform to choose the target state of the device
2029 * and enable wake-up from this state if supported.
2030 */
2031 pci_power_t state = platform_pci_choose_state(dev);
2032
2033 switch (state) {
2034 case PCI_POWER_ERROR:
2035 case PCI_UNKNOWN:
2036 break;
2037 case PCI_D1:
2038 case PCI_D2:
2039 if (pci_no_d1d2(dev))
2040 break;
2041 default:
2042 target_state = state;
2043 }
2044
2045 return target_state;
2046 }
2047
2048 if (!dev->pm_cap)
2049 target_state = PCI_D0;
2050
2051 /*
2052 * If the device is in D3cold even though it's not power-manageable by
2053 * the platform, it may have been powered down by non-standard means.
2054 * Best to let it slumber.
2055 */
2056 if (dev->current_state == PCI_D3cold)
2057 target_state = PCI_D3cold;
2058
2059 if (wakeup) {
2060 /*
2061 * Find the deepest state from which the device can generate
2062 * wake-up events, make it the target state and enable device
2063 * to generate PME#.
2064 */
2065 if (dev->pme_support) {
2066 while (target_state
2067 && !(dev->pme_support & (1 << target_state)))
2068 target_state--;
2069 }
2070 }
2071
2072 return target_state;
2073}
2074
2075/**
2076 * pci_prepare_to_sleep - prepare PCI device for system-wide transition into a sleep state
2077 * @dev: Device to handle.
2078 *
2079 * Choose the power state appropriate for the device depending on whether
2080 * it can wake up the system and/or is power manageable by the platform
2081 * (PCI_D3hot is the default) and put the device into that state.
2082 */
2083int pci_prepare_to_sleep(struct pci_dev *dev)
2084{
2085 bool wakeup = device_may_wakeup(&dev->dev);
2086 pci_power_t target_state = pci_target_state(dev, wakeup);
2087 int error;
2088
2089 if (target_state == PCI_POWER_ERROR)
2090 return -EIO;
2091
2092 pci_enable_wake(dev, target_state, wakeup);
2093
2094 error = pci_set_power_state(dev, target_state);
2095
2096 if (error)
2097 pci_enable_wake(dev, target_state, false);
2098
2099 return error;
2100}
2101EXPORT_SYMBOL(pci_prepare_to_sleep);
2102
2103/**
2104 * pci_back_from_sleep - turn PCI device on during system-wide transition into working state
2105 * @dev: Device to handle.
2106 *
2107 * Disable device's system wake-up capability and put it into D0.
2108 */
2109int pci_back_from_sleep(struct pci_dev *dev)
2110{
2111 pci_enable_wake(dev, PCI_D0, false);
2112 return pci_set_power_state(dev, PCI_D0);
2113}
2114EXPORT_SYMBOL(pci_back_from_sleep);
2115
2116/**
2117 * pci_finish_runtime_suspend - Carry out PCI-specific part of runtime suspend.
2118 * @dev: PCI device being suspended.
2119 *
2120 * Prepare @dev to generate wake-up events at run time and put it into a low
2121 * power state.
2122 */
2123int pci_finish_runtime_suspend(struct pci_dev *dev)
2124{
2125 pci_power_t target_state;
2126 int error;
2127
2128 target_state = pci_target_state(dev, device_can_wakeup(&dev->dev));
2129 if (target_state == PCI_POWER_ERROR)
2130 return -EIO;
2131
2132 dev->runtime_d3cold = target_state == PCI_D3cold;
2133
2134 __pci_enable_wake(dev, target_state, pci_dev_run_wake(dev));
2135
2136 error = pci_set_power_state(dev, target_state);
2137
2138 if (error) {
2139 pci_enable_wake(dev, target_state, false);
2140 dev->runtime_d3cold = false;
2141 }
2142
2143 return error;
2144}
2145
2146/**
2147 * pci_dev_run_wake - Check if device can generate run-time wake-up events.
2148 * @dev: Device to check.
2149 *
2150 * Return true if the device itself is capable of generating wake-up events
2151 * (through the platform or using the native PCIe PME) or if the device supports
2152 * PME and one of its upstream bridges can generate wake-up events.
2153 */
2154bool pci_dev_run_wake(struct pci_dev *dev)
2155{
2156 struct pci_bus *bus = dev->bus;
2157
2158 if (!dev->pme_support)
2159 return false;
2160
2161 /* PME-capable in principle, but not from the target power state */
2162 if (!pci_pme_capable(dev, pci_target_state(dev, true)))
2163 return false;
2164
2165 if (device_can_wakeup(&dev->dev))
2166 return true;
2167
2168 while (bus->parent) {
2169 struct pci_dev *bridge = bus->self;
2170
2171 if (device_can_wakeup(&bridge->dev))
2172 return true;
2173
2174 bus = bus->parent;
2175 }
2176
2177 /* We have reached the root bus. */
2178 if (bus->bridge)
2179 return device_can_wakeup(bus->bridge);
2180
2181 return false;
2182}
2183EXPORT_SYMBOL_GPL(pci_dev_run_wake);
2184
2185/**
2186 * pci_dev_keep_suspended - Check if the device can stay in the suspended state.
2187 * @pci_dev: Device to check.
2188 *
2189 * Return 'true' if the device is runtime-suspended, it doesn't have to be
2190 * reconfigured due to wakeup settings difference between system and runtime
2191 * suspend and the current power state of it is suitable for the upcoming
2192 * (system) transition.
2193 *
2194 * If the device is not configured for system wakeup, disable PME for it before
2195 * returning 'true' to prevent it from waking up the system unnecessarily.
2196 */
2197bool pci_dev_keep_suspended(struct pci_dev *pci_dev)
2198{
2199 struct device *dev = &pci_dev->dev;
2200 bool wakeup = device_may_wakeup(dev);
2201
2202 if (!pm_runtime_suspended(dev)
2203 || pci_target_state(pci_dev, wakeup) != pci_dev->current_state
2204 || platform_pci_need_resume(pci_dev))
2205 return false;
2206
2207 /*
2208 * At this point the device is good to go unless it's been configured
2209 * to generate PME at the runtime suspend time, but it is not supposed
2210 * to wake up the system. In that case, simply disable PME for it
2211 * (it will have to be re-enabled on exit from system resume).
2212 *
2213 * If the device's power state is D3cold and the platform check above
2214 * hasn't triggered, the device's configuration is suitable and we don't
2215 * need to manipulate it at all.
2216 */
2217 spin_lock_irq(&dev->power.lock);
2218
2219 if (pm_runtime_suspended(dev) && pci_dev->current_state < PCI_D3cold &&
2220 !wakeup)
2221 __pci_pme_active(pci_dev, false);
2222
2223 spin_unlock_irq(&dev->power.lock);
2224 return true;
2225}
2226
2227/**
2228 * pci_dev_complete_resume - Finalize resume from system sleep for a device.
2229 * @pci_dev: Device to handle.
2230 *
2231 * If the device is runtime suspended and wakeup-capable, enable PME for it as
2232 * it might have been disabled during the prepare phase of system suspend if
2233 * the device was not configured for system wakeup.
2234 */
2235void pci_dev_complete_resume(struct pci_dev *pci_dev)
2236{
2237 struct device *dev = &pci_dev->dev;
2238
2239 if (!pci_dev_run_wake(pci_dev))
2240 return;
2241
2242 spin_lock_irq(&dev->power.lock);
2243
2244 if (pm_runtime_suspended(dev) && pci_dev->current_state < PCI_D3cold)
2245 __pci_pme_active(pci_dev, true);
2246
2247 spin_unlock_irq(&dev->power.lock);
2248}
2249
2250void pci_config_pm_runtime_get(struct pci_dev *pdev)
2251{
2252 struct device *dev = &pdev->dev;
2253 struct device *parent = dev->parent;
2254
2255 if (parent)
2256 pm_runtime_get_sync(parent);
2257 pm_runtime_get_noresume(dev);
2258 /*
2259 * pdev->current_state is set to PCI_D3cold during suspending,
2260 * so wait until suspending completes
2261 */
2262 pm_runtime_barrier(dev);
2263 /*
2264 * Only need to resume devices in D3cold, because config
2265 * registers are still accessible for devices suspended but
2266 * not in D3cold.
2267 */
2268 if (pdev->current_state == PCI_D3cold)
2269 pm_runtime_resume(dev);
2270}
2271
2272void pci_config_pm_runtime_put(struct pci_dev *pdev)
2273{
2274 struct device *dev = &pdev->dev;
2275 struct device *parent = dev->parent;
2276
2277 pm_runtime_put(dev);
2278 if (parent)
2279 pm_runtime_put_sync(parent);
2280}
2281
2282/**
2283 * pci_bridge_d3_possible - Is it possible to put the bridge into D3
2284 * @bridge: Bridge to check
2285 *
2286 * This function checks if it is possible to move the bridge to D3.
2287 * Currently we only allow D3 for recent enough PCIe ports.
2288 */
2289bool pci_bridge_d3_possible(struct pci_dev *bridge)
2290{
2291 if (!pci_is_pcie(bridge))
2292 return false;
2293
2294 switch (pci_pcie_type(bridge)) {
2295 case PCI_EXP_TYPE_ROOT_PORT:
2296 case PCI_EXP_TYPE_UPSTREAM:
2297 case PCI_EXP_TYPE_DOWNSTREAM:
2298 if (pci_bridge_d3_disable)
2299 return false;
2300
2301 /*
2302 * Hotplug interrupts cannot be delivered if the link is down,
2303 * so parents of a hotplug port must stay awake. In addition,
2304 * hotplug ports handled by firmware in System Management Mode
2305 * may not be put into D3 by the OS (Thunderbolt on non-Macs).
2306 * For simplicity, disallow in general for now.
2307 */
2308 if (bridge->is_hotplug_bridge)
2309 return false;
2310
2311 if (pci_bridge_d3_force)
2312 return true;
2313
2314 /*
2315 * It should be safe to put PCIe ports from 2015 or newer
2316 * to D3.
2317 */
2318 if (dmi_get_bios_year() >= 2015)
2319 return true;
2320 break;
2321 }
2322
2323 return false;
2324}
2325
2326static int pci_dev_check_d3cold(struct pci_dev *dev, void *data)
2327{
2328 bool *d3cold_ok = data;
2329
2330 if (/* The device needs to be allowed to go D3cold ... */
2331 dev->no_d3cold || !dev->d3cold_allowed ||
2332
2333 /* ... and if it is wakeup capable to do so from D3cold. */
2334 (device_may_wakeup(&dev->dev) &&
2335 !pci_pme_capable(dev, PCI_D3cold)) ||
2336
2337 /* If it is a bridge it must be allowed to go to D3. */
2338 !pci_power_manageable(dev))
2339
2340 *d3cold_ok = false;
2341
2342 return !*d3cold_ok;
2343}
2344
2345/*
2346 * pci_bridge_d3_update - Update bridge D3 capabilities
2347 * @dev: PCI device which is changed
2348 *
2349 * Update upstream bridge PM capabilities accordingly depending on if the
2350 * device PM configuration was changed or the device is being removed. The
2351 * change is also propagated upstream.
2352 */
2353void pci_bridge_d3_update(struct pci_dev *dev)
2354{
2355 bool remove = !device_is_registered(&dev->dev);
2356 struct pci_dev *bridge;
2357 bool d3cold_ok = true;
2358
2359 bridge = pci_upstream_bridge(dev);
2360 if (!bridge || !pci_bridge_d3_possible(bridge))
2361 return;
2362
2363 /*
2364 * If D3 is currently allowed for the bridge, removing one of its
2365 * children won't change that.
2366 */
2367 if (remove && bridge->bridge_d3)
2368 return;
2369
2370 /*
2371 * If D3 is currently allowed for the bridge and a child is added or
2372 * changed, disallowance of D3 can only be caused by that child, so
2373 * we only need to check that single device, not any of its siblings.
2374 *
2375 * If D3 is currently not allowed for the bridge, checking the device
2376 * first may allow us to skip checking its siblings.
2377 */
2378 if (!remove)
2379 pci_dev_check_d3cold(dev, &d3cold_ok);
2380
2381 /*
2382 * If D3 is currently not allowed for the bridge, this may be caused
2383 * either by the device being changed/removed or any of its siblings,
2384 * so we need to go through all children to find out if one of them
2385 * continues to block D3.
2386 */
2387 if (d3cold_ok && !bridge->bridge_d3)
2388 pci_walk_bus(bridge->subordinate, pci_dev_check_d3cold,
2389 &d3cold_ok);
2390
2391 if (bridge->bridge_d3 != d3cold_ok) {
2392 bridge->bridge_d3 = d3cold_ok;
2393 /* Propagate change to upstream bridges */
2394 pci_bridge_d3_update(bridge);
2395 }
2396}
2397
2398/**
2399 * pci_d3cold_enable - Enable D3cold for device
2400 * @dev: PCI device to handle
2401 *
2402 * This function can be used in drivers to enable D3cold from the device
2403 * they handle. It also updates upstream PCI bridge PM capabilities
2404 * accordingly.
2405 */
2406void pci_d3cold_enable(struct pci_dev *dev)
2407{
2408 if (dev->no_d3cold) {
2409 dev->no_d3cold = false;
2410 pci_bridge_d3_update(dev);
2411 }
2412}
2413EXPORT_SYMBOL_GPL(pci_d3cold_enable);
2414
2415/**
2416 * pci_d3cold_disable - Disable D3cold for device
2417 * @dev: PCI device to handle
2418 *
2419 * This function can be used in drivers to disable D3cold from the device
2420 * they handle. It also updates upstream PCI bridge PM capabilities
2421 * accordingly.
2422 */
2423void pci_d3cold_disable(struct pci_dev *dev)
2424{
2425 if (!dev->no_d3cold) {
2426 dev->no_d3cold = true;
2427 pci_bridge_d3_update(dev);
2428 }
2429}
2430EXPORT_SYMBOL_GPL(pci_d3cold_disable);
2431
2432/**
2433 * pci_pm_init - Initialize PM functions of given PCI device
2434 * @dev: PCI device to handle.
2435 */
2436void pci_pm_init(struct pci_dev *dev)
2437{
2438 int pm;
2439 u16 pmc;
2440
2441 pm_runtime_forbid(&dev->dev);
2442 pm_runtime_set_active(&dev->dev);
2443 pm_runtime_enable(&dev->dev);
2444 device_enable_async_suspend(&dev->dev);
2445 dev->wakeup_prepared = false;
2446
2447 dev->pm_cap = 0;
2448 dev->pme_support = 0;
2449
2450 /* find PCI PM capability in list */
2451 pm = pci_find_capability(dev, PCI_CAP_ID_PM);
2452 if (!pm)
2453 return;
2454 /* Check device's ability to generate PME# */
2455 pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
2456
2457 if ((pmc & PCI_PM_CAP_VER_MASK) > 3) {
2458 pci_err(dev, "unsupported PM cap regs version (%u)\n",
2459 pmc & PCI_PM_CAP_VER_MASK);
2460 return;
2461 }
2462
2463 dev->pm_cap = pm;
2464 dev->d3_delay = PCI_PM_D3_WAIT;
2465 dev->d3cold_delay = PCI_PM_D3COLD_WAIT;
2466 dev->bridge_d3 = pci_bridge_d3_possible(dev);
2467 dev->d3cold_allowed = true;
2468
2469 dev->d1_support = false;
2470 dev->d2_support = false;
2471 if (!pci_no_d1d2(dev)) {
2472 if (pmc & PCI_PM_CAP_D1)
2473 dev->d1_support = true;
2474 if (pmc & PCI_PM_CAP_D2)
2475 dev->d2_support = true;
2476
2477 if (dev->d1_support || dev->d2_support)
2478 pci_printk(KERN_DEBUG, dev, "supports%s%s\n",
2479 dev->d1_support ? " D1" : "",
2480 dev->d2_support ? " D2" : "");
2481 }
2482
2483 pmc &= PCI_PM_CAP_PME_MASK;
2484 if (pmc) {
2485 pci_printk(KERN_DEBUG, dev, "PME# supported from%s%s%s%s%s\n",
2486 (pmc & PCI_PM_CAP_PME_D0) ? " D0" : "",
2487 (pmc & PCI_PM_CAP_PME_D1) ? " D1" : "",
2488 (pmc & PCI_PM_CAP_PME_D2) ? " D2" : "",
2489 (pmc & PCI_PM_CAP_PME_D3) ? " D3hot" : "",
2490 (pmc & PCI_PM_CAP_PME_D3cold) ? " D3cold" : "");
2491 dev->pme_support = pmc >> PCI_PM_CAP_PME_SHIFT;
2492 dev->pme_poll = true;
2493 /*
2494 * Make device's PM flags reflect the wake-up capability, but
2495 * let the user space enable it to wake up the system as needed.
2496 */
2497 device_set_wakeup_capable(&dev->dev, true);
2498 /* Disable the PME# generation functionality */
2499 pci_pme_active(dev, false);
2500 }
2501}
2502
2503static unsigned long pci_ea_flags(struct pci_dev *dev, u8 prop)
2504{
2505 unsigned long flags = IORESOURCE_PCI_FIXED | IORESOURCE_PCI_EA_BEI;
2506
2507 switch (prop) {
2508 case PCI_EA_P_MEM:
2509 case PCI_EA_P_VF_MEM:
2510 flags |= IORESOURCE_MEM;
2511 break;
2512 case PCI_EA_P_MEM_PREFETCH:
2513 case PCI_EA_P_VF_MEM_PREFETCH:
2514 flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH;
2515 break;
2516 case PCI_EA_P_IO:
2517 flags |= IORESOURCE_IO;
2518 break;
2519 default:
2520 return 0;
2521 }
2522
2523 return flags;
2524}
2525
2526static struct resource *pci_ea_get_resource(struct pci_dev *dev, u8 bei,
2527 u8 prop)
2528{
2529 if (bei <= PCI_EA_BEI_BAR5 && prop <= PCI_EA_P_IO)
2530 return &dev->resource[bei];
2531#ifdef CONFIG_PCI_IOV
2532 else if (bei >= PCI_EA_BEI_VF_BAR0 && bei <= PCI_EA_BEI_VF_BAR5 &&
2533 (prop == PCI_EA_P_VF_MEM || prop == PCI_EA_P_VF_MEM_PREFETCH))
2534 return &dev->resource[PCI_IOV_RESOURCES +
2535 bei - PCI_EA_BEI_VF_BAR0];
2536#endif
2537 else if (bei == PCI_EA_BEI_ROM)
2538 return &dev->resource[PCI_ROM_RESOURCE];
2539 else
2540 return NULL;
2541}
2542
2543/* Read an Enhanced Allocation (EA) entry */
2544static int pci_ea_read(struct pci_dev *dev, int offset)
2545{
2546 struct resource *res;
2547 int ent_size, ent_offset = offset;
2548 resource_size_t start, end;
2549 unsigned long flags;
2550 u32 dw0, bei, base, max_offset;
2551 u8 prop;
2552 bool support_64 = (sizeof(resource_size_t) >= 8);
2553
2554 pci_read_config_dword(dev, ent_offset, &dw0);
2555 ent_offset += 4;
2556
2557 /* Entry size field indicates DWORDs after 1st */
2558 ent_size = ((dw0 & PCI_EA_ES) + 1) << 2;
2559
2560 if (!(dw0 & PCI_EA_ENABLE)) /* Entry not enabled */
2561 goto out;
2562
2563 bei = (dw0 & PCI_EA_BEI) >> 4;
2564 prop = (dw0 & PCI_EA_PP) >> 8;
2565
2566 /*
2567 * If the Property is in the reserved range, try the Secondary
2568 * Property instead.
2569 */
2570 if (prop > PCI_EA_P_BRIDGE_IO && prop < PCI_EA_P_MEM_RESERVED)
2571 prop = (dw0 & PCI_EA_SP) >> 16;
2572 if (prop > PCI_EA_P_BRIDGE_IO)
2573 goto out;
2574
2575 res = pci_ea_get_resource(dev, bei, prop);
2576 if (!res) {
2577 pci_err(dev, "Unsupported EA entry BEI: %u\n", bei);
2578 goto out;
2579 }
2580
2581 flags = pci_ea_flags(dev, prop);
2582 if (!flags) {
2583 pci_err(dev, "Unsupported EA properties: %#x\n", prop);
2584 goto out;
2585 }
2586
2587 /* Read Base */
2588 pci_read_config_dword(dev, ent_offset, &base);
2589 start = (base & PCI_EA_FIELD_MASK);
2590 ent_offset += 4;
2591
2592 /* Read MaxOffset */
2593 pci_read_config_dword(dev, ent_offset, &max_offset);
2594 ent_offset += 4;
2595
2596 /* Read Base MSBs (if 64-bit entry) */
2597 if (base & PCI_EA_IS_64) {
2598 u32 base_upper;
2599
2600 pci_read_config_dword(dev, ent_offset, &base_upper);
2601 ent_offset += 4;
2602
2603 flags |= IORESOURCE_MEM_64;
2604
2605 /* entry starts above 32-bit boundary, can't use */
2606 if (!support_64 && base_upper)
2607 goto out;
2608
2609 if (support_64)
2610 start |= ((u64)base_upper << 32);
2611 }
2612
2613 end = start + (max_offset | 0x03);
2614
2615 /* Read MaxOffset MSBs (if 64-bit entry) */
2616 if (max_offset & PCI_EA_IS_64) {
2617 u32 max_offset_upper;
2618
2619 pci_read_config_dword(dev, ent_offset, &max_offset_upper);
2620 ent_offset += 4;
2621
2622 flags |= IORESOURCE_MEM_64;
2623
2624 /* entry too big, can't use */
2625 if (!support_64 && max_offset_upper)
2626 goto out;
2627
2628 if (support_64)
2629 end += ((u64)max_offset_upper << 32);
2630 }
2631
2632 if (end < start) {
2633 pci_err(dev, "EA Entry crosses address boundary\n");
2634 goto out;
2635 }
2636
2637 if (ent_size != ent_offset - offset) {
2638 pci_err(dev, "EA Entry Size (%d) does not match length read (%d)\n",
2639 ent_size, ent_offset - offset);
2640 goto out;
2641 }
2642
2643 res->name = pci_name(dev);
2644 res->start = start;
2645 res->end = end;
2646 res->flags = flags;
2647
2648 if (bei <= PCI_EA_BEI_BAR5)
2649 pci_printk(KERN_DEBUG, dev, "BAR %d: %pR (from Enhanced Allocation, properties %#02x)\n",
2650 bei, res, prop);
2651 else if (bei == PCI_EA_BEI_ROM)
2652 pci_printk(KERN_DEBUG, dev, "ROM: %pR (from Enhanced Allocation, properties %#02x)\n",
2653 res, prop);
2654 else if (bei >= PCI_EA_BEI_VF_BAR0 && bei <= PCI_EA_BEI_VF_BAR5)
2655 pci_printk(KERN_DEBUG, dev, "VF BAR %d: %pR (from Enhanced Allocation, properties %#02x)\n",
2656 bei - PCI_EA_BEI_VF_BAR0, res, prop);
2657 else
2658 pci_printk(KERN_DEBUG, dev, "BEI %d res: %pR (from Enhanced Allocation, properties %#02x)\n",
2659 bei, res, prop);
2660
2661out:
2662 return offset + ent_size;
2663}
2664
2665/* Enhanced Allocation Initialization */
2666void pci_ea_init(struct pci_dev *dev)
2667{
2668 int ea;
2669 u8 num_ent;
2670 int offset;
2671 int i;
2672
2673 /* find PCI EA capability in list */
2674 ea = pci_find_capability(dev, PCI_CAP_ID_EA);
2675 if (!ea)
2676 return;
2677
2678 /* determine the number of entries */
2679 pci_bus_read_config_byte(dev->bus, dev->devfn, ea + PCI_EA_NUM_ENT,
2680 &num_ent);
2681 num_ent &= PCI_EA_NUM_ENT_MASK;
2682
2683 offset = ea + PCI_EA_FIRST_ENT;
2684
2685 /* Skip DWORD 2 for type 1 functions */
2686 if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)
2687 offset += 4;
2688
2689 /* parse each EA entry */
2690 for (i = 0; i < num_ent; ++i)
2691 offset = pci_ea_read(dev, offset);
2692}
2693
2694static void pci_add_saved_cap(struct pci_dev *pci_dev,
2695 struct pci_cap_saved_state *new_cap)
2696{
2697 hlist_add_head(&new_cap->next, &pci_dev->saved_cap_space);
2698}
2699
2700/**
2701 * _pci_add_cap_save_buffer - allocate buffer for saving given
2702 * capability registers
2703 * @dev: the PCI device
2704 * @cap: the capability to allocate the buffer for
2705 * @extended: Standard or Extended capability ID
2706 * @size: requested size of the buffer
2707 */
2708static int _pci_add_cap_save_buffer(struct pci_dev *dev, u16 cap,
2709 bool extended, unsigned int size)
2710{
2711 int pos;
2712 struct pci_cap_saved_state *save_state;
2713
2714 if (extended)
2715 pos = pci_find_ext_capability(dev, cap);
2716 else
2717 pos = pci_find_capability(dev, cap);
2718
2719 if (!pos)
2720 return 0;
2721
2722 save_state = kzalloc(sizeof(*save_state) + size, GFP_KERNEL);
2723 if (!save_state)
2724 return -ENOMEM;
2725
2726 save_state->cap.cap_nr = cap;
2727 save_state->cap.cap_extended = extended;
2728 save_state->cap.size = size;
2729 pci_add_saved_cap(dev, save_state);
2730
2731 return 0;
2732}
2733
2734int pci_add_cap_save_buffer(struct pci_dev *dev, char cap, unsigned int size)
2735{
2736 return _pci_add_cap_save_buffer(dev, cap, false, size);
2737}
2738
2739int pci_add_ext_cap_save_buffer(struct pci_dev *dev, u16 cap, unsigned int size)
2740{
2741 return _pci_add_cap_save_buffer(dev, cap, true, size);
2742}
2743
2744/**
2745 * pci_allocate_cap_save_buffers - allocate buffers for saving capabilities
2746 * @dev: the PCI device
2747 */
2748void pci_allocate_cap_save_buffers(struct pci_dev *dev)
2749{
2750 int error;
2751
2752 error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_EXP,
2753 PCI_EXP_SAVE_REGS * sizeof(u16));
2754 if (error)
2755 pci_err(dev, "unable to preallocate PCI Express save buffer\n");
2756
2757 error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_PCIX, sizeof(u16));
2758 if (error)
2759 pci_err(dev, "unable to preallocate PCI-X save buffer\n");
2760
2761 pci_allocate_vc_save_buffers(dev);
2762}
2763
2764void pci_free_cap_save_buffers(struct pci_dev *dev)
2765{
2766 struct pci_cap_saved_state *tmp;
2767 struct hlist_node *n;
2768
2769 hlist_for_each_entry_safe(tmp, n, &dev->saved_cap_space, next)
2770 kfree(tmp);
2771}
2772
2773/**
2774 * pci_configure_ari - enable or disable ARI forwarding
2775 * @dev: the PCI device
2776 *
2777 * If @dev and its upstream bridge both support ARI, enable ARI in the
2778 * bridge. Otherwise, disable ARI in the bridge.
2779 */
2780void pci_configure_ari(struct pci_dev *dev)
2781{
2782 u32 cap;
2783 struct pci_dev *bridge;
2784
2785 if (pcie_ari_disabled || !pci_is_pcie(dev) || dev->devfn)
2786 return;
2787
2788 bridge = dev->bus->self;
2789 if (!bridge)
2790 return;
2791
2792 pcie_capability_read_dword(bridge, PCI_EXP_DEVCAP2, &cap);
2793 if (!(cap & PCI_EXP_DEVCAP2_ARI))
2794 return;
2795
2796 if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI)) {
2797 pcie_capability_set_word(bridge, PCI_EXP_DEVCTL2,
2798 PCI_EXP_DEVCTL2_ARI);
2799 bridge->ari_enabled = 1;
2800 } else {
2801 pcie_capability_clear_word(bridge, PCI_EXP_DEVCTL2,
2802 PCI_EXP_DEVCTL2_ARI);
2803 bridge->ari_enabled = 0;
2804 }
2805}
2806
2807static int pci_acs_enable;
2808
2809/**
2810 * pci_request_acs - ask for ACS to be enabled if supported
2811 */
2812void pci_request_acs(void)
2813{
2814 pci_acs_enable = 1;
2815}
2816
2817/**
2818 * pci_std_enable_acs - enable ACS on devices using standard ACS capabilites
2819 * @dev: the PCI device
2820 */
2821static void pci_std_enable_acs(struct pci_dev *dev)
2822{
2823 int pos;
2824 u16 cap;
2825 u16 ctrl;
2826
2827 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS);
2828 if (!pos)
2829 return;
2830
2831 pci_read_config_word(dev, pos + PCI_ACS_CAP, &cap);
2832 pci_read_config_word(dev, pos + PCI_ACS_CTRL, &ctrl);
2833
2834 /* Source Validation */
2835 ctrl |= (cap & PCI_ACS_SV);
2836
2837 /* P2P Request Redirect */
2838 ctrl |= (cap & PCI_ACS_RR);
2839
2840 /* P2P Completion Redirect */
2841 ctrl |= (cap & PCI_ACS_CR);
2842
2843 /* Upstream Forwarding */
2844 ctrl |= (cap & PCI_ACS_UF);
2845
2846 pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl);
2847}
2848
2849/**
2850 * pci_enable_acs - enable ACS if hardware support it
2851 * @dev: the PCI device
2852 */
2853void pci_enable_acs(struct pci_dev *dev)
2854{
2855 if (!pci_acs_enable)
2856 return;
2857
2858 if (!pci_dev_specific_enable_acs(dev))
2859 return;
2860
2861 pci_std_enable_acs(dev);
2862}
2863
2864static bool pci_acs_flags_enabled(struct pci_dev *pdev, u16 acs_flags)
2865{
2866 int pos;
2867 u16 cap, ctrl;
2868
2869 pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ACS);
2870 if (!pos)
2871 return false;
2872
2873 /*
2874 * Except for egress control, capabilities are either required
2875 * or only required if controllable. Features missing from the
2876 * capability field can therefore be assumed as hard-wired enabled.
2877 */
2878 pci_read_config_word(pdev, pos + PCI_ACS_CAP, &cap);
2879 acs_flags &= (cap | PCI_ACS_EC);
2880
2881 pci_read_config_word(pdev, pos + PCI_ACS_CTRL, &ctrl);
2882 return (ctrl & acs_flags) == acs_flags;
2883}
2884
2885/**
2886 * pci_acs_enabled - test ACS against required flags for a given device
2887 * @pdev: device to test
2888 * @acs_flags: required PCI ACS flags
2889 *
2890 * Return true if the device supports the provided flags. Automatically
2891 * filters out flags that are not implemented on multifunction devices.
2892 *
2893 * Note that this interface checks the effective ACS capabilities of the
2894 * device rather than the actual capabilities. For instance, most single
2895 * function endpoints are not required to support ACS because they have no
2896 * opportunity for peer-to-peer access. We therefore return 'true'
2897 * regardless of whether the device exposes an ACS capability. This makes
2898 * it much easier for callers of this function to ignore the actual type
2899 * or topology of the device when testing ACS support.
2900 */
2901bool pci_acs_enabled(struct pci_dev *pdev, u16 acs_flags)
2902{
2903 int ret;
2904
2905 ret = pci_dev_specific_acs_enabled(pdev, acs_flags);
2906 if (ret >= 0)
2907 return ret > 0;
2908
2909 /*
2910 * Conventional PCI and PCI-X devices never support ACS, either
2911 * effectively or actually. The shared bus topology implies that
2912 * any device on the bus can receive or snoop DMA.
2913 */
2914 if (!pci_is_pcie(pdev))
2915 return false;
2916
2917 switch (pci_pcie_type(pdev)) {
2918 /*
2919 * PCI/X-to-PCIe bridges are not specifically mentioned by the spec,
2920 * but since their primary interface is PCI/X, we conservatively
2921 * handle them as we would a non-PCIe device.
2922 */
2923 case PCI_EXP_TYPE_PCIE_BRIDGE:
2924 /*
2925 * PCIe 3.0, 6.12.1 excludes ACS on these devices. "ACS is never
2926 * applicable... must never implement an ACS Extended Capability...".
2927 * This seems arbitrary, but we take a conservative interpretation
2928 * of this statement.
2929 */
2930 case PCI_EXP_TYPE_PCI_BRIDGE:
2931 case PCI_EXP_TYPE_RC_EC:
2932 return false;
2933 /*
2934 * PCIe 3.0, 6.12.1.1 specifies that downstream and root ports should
2935 * implement ACS in order to indicate their peer-to-peer capabilities,
2936 * regardless of whether they are single- or multi-function devices.
2937 */
2938 case PCI_EXP_TYPE_DOWNSTREAM:
2939 case PCI_EXP_TYPE_ROOT_PORT:
2940 return pci_acs_flags_enabled(pdev, acs_flags);
2941 /*
2942 * PCIe 3.0, 6.12.1.2 specifies ACS capabilities that should be
2943 * implemented by the remaining PCIe types to indicate peer-to-peer
2944 * capabilities, but only when they are part of a multifunction
2945 * device. The footnote for section 6.12 indicates the specific
2946 * PCIe types included here.
2947 */
2948 case PCI_EXP_TYPE_ENDPOINT:
2949 case PCI_EXP_TYPE_UPSTREAM:
2950 case PCI_EXP_TYPE_LEG_END:
2951 case PCI_EXP_TYPE_RC_END:
2952 if (!pdev->multifunction)
2953 break;
2954
2955 return pci_acs_flags_enabled(pdev, acs_flags);
2956 }
2957
2958 /*
2959 * PCIe 3.0, 6.12.1.3 specifies no ACS capabilities are applicable
2960 * to single function devices with the exception of downstream ports.
2961 */
2962 return true;
2963}
2964
2965/**
2966 * pci_acs_path_enable - test ACS flags from start to end in a hierarchy
2967 * @start: starting downstream device
2968 * @end: ending upstream device or NULL to search to the root bus
2969 * @acs_flags: required flags
2970 *
2971 * Walk up a device tree from start to end testing PCI ACS support. If
2972 * any step along the way does not support the required flags, return false.
2973 */
2974bool pci_acs_path_enabled(struct pci_dev *start,
2975 struct pci_dev *end, u16 acs_flags)
2976{
2977 struct pci_dev *pdev, *parent = start;
2978
2979 do {
2980 pdev = parent;
2981
2982 if (!pci_acs_enabled(pdev, acs_flags))
2983 return false;
2984
2985 if (pci_is_root_bus(pdev->bus))
2986 return (end == NULL);
2987
2988 parent = pdev->bus->self;
2989 } while (pdev != end);
2990
2991 return true;
2992}
2993
2994/**
2995 * pci_rebar_find_pos - find position of resize ctrl reg for BAR
2996 * @pdev: PCI device
2997 * @bar: BAR to find
2998 *
2999 * Helper to find the position of the ctrl register for a BAR.
3000 * Returns -ENOTSUPP if resizable BARs are not supported at all.
3001 * Returns -ENOENT if no ctrl register for the BAR could be found.
3002 */
3003static int pci_rebar_find_pos(struct pci_dev *pdev, int bar)
3004{
3005 unsigned int pos, nbars, i;
3006 u32 ctrl;
3007
3008 pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR);
3009 if (!pos)
3010 return -ENOTSUPP;
3011
3012 pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
3013 nbars = (ctrl & PCI_REBAR_CTRL_NBAR_MASK) >>
3014 PCI_REBAR_CTRL_NBAR_SHIFT;
3015
3016 for (i = 0; i < nbars; i++, pos += 8) {
3017 int bar_idx;
3018
3019 pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
3020 bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX;
3021 if (bar_idx == bar)
3022 return pos;
3023 }
3024
3025 return -ENOENT;
3026}
3027
3028/**
3029 * pci_rebar_get_possible_sizes - get possible sizes for BAR
3030 * @pdev: PCI device
3031 * @bar: BAR to query
3032 *
3033 * Get the possible sizes of a resizable BAR as bitmask defined in the spec
3034 * (bit 0=1MB, bit 19=512GB). Returns 0 if BAR isn't resizable.
3035 */
3036u32 pci_rebar_get_possible_sizes(struct pci_dev *pdev, int bar)
3037{
3038 int pos;
3039 u32 cap;
3040
3041 pos = pci_rebar_find_pos(pdev, bar);
3042 if (pos < 0)
3043 return 0;
3044
3045 pci_read_config_dword(pdev, pos + PCI_REBAR_CAP, &cap);
3046 return (cap & PCI_REBAR_CAP_SIZES) >> 4;
3047}
3048
3049/**
3050 * pci_rebar_get_current_size - get the current size of a BAR
3051 * @pdev: PCI device
3052 * @bar: BAR to set size to
3053 *
3054 * Read the size of a BAR from the resizable BAR config.
3055 * Returns size if found or negative error code.
3056 */
3057int pci_rebar_get_current_size(struct pci_dev *pdev, int bar)
3058{
3059 int pos;
3060 u32 ctrl;
3061
3062 pos = pci_rebar_find_pos(pdev, bar);
3063 if (pos < 0)
3064 return pos;
3065
3066 pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
3067 return (ctrl & PCI_REBAR_CTRL_BAR_SIZE) >> 8;
3068}
3069
3070/**
3071 * pci_rebar_set_size - set a new size for a BAR
3072 * @pdev: PCI device
3073 * @bar: BAR to set size to
3074 * @size: new size as defined in the spec (0=1MB, 19=512GB)
3075 *
3076 * Set the new size of a BAR as defined in the spec.
3077 * Returns zero if resizing was successful, error code otherwise.
3078 */
3079int pci_rebar_set_size(struct pci_dev *pdev, int bar, int size)
3080{
3081 int pos;
3082 u32 ctrl;
3083
3084 pos = pci_rebar_find_pos(pdev, bar);
3085 if (pos < 0)
3086 return pos;
3087
3088 pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
3089 ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE;
3090 ctrl |= size << 8;
3091 pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl);
3092 return 0;
3093}
3094
3095/**
3096 * pci_enable_atomic_ops_to_root - enable AtomicOp requests to root port
3097 * @dev: the PCI device
3098 * @cap_mask: mask of desired AtomicOp sizes, including one or more of:
3099 * PCI_EXP_DEVCAP2_ATOMIC_COMP32
3100 * PCI_EXP_DEVCAP2_ATOMIC_COMP64
3101 * PCI_EXP_DEVCAP2_ATOMIC_COMP128
3102 *
3103 * Return 0 if all upstream bridges support AtomicOp routing, egress
3104 * blocking is disabled on all upstream ports, and the root port supports
3105 * the requested completion capabilities (32-bit, 64-bit and/or 128-bit
3106 * AtomicOp completion), or negative otherwise.
3107 */
3108int pci_enable_atomic_ops_to_root(struct pci_dev *dev, u32 cap_mask)
3109{
3110 struct pci_bus *bus = dev->bus;
3111 struct pci_dev *bridge;
3112 u32 cap, ctl2;
3113
3114 if (!pci_is_pcie(dev))
3115 return -EINVAL;
3116
3117 /*
3118 * Per PCIe r4.0, sec 6.15, endpoints and root ports may be
3119 * AtomicOp requesters. For now, we only support endpoints as
3120 * requesters and root ports as completers. No endpoints as
3121 * completers, and no peer-to-peer.
3122 */
3123
3124 switch (pci_pcie_type(dev)) {
3125 case PCI_EXP_TYPE_ENDPOINT:
3126 case PCI_EXP_TYPE_LEG_END:
3127 case PCI_EXP_TYPE_RC_END:
3128 break;
3129 default:
3130 return -EINVAL;
3131 }
3132
3133 while (bus->parent) {
3134 bridge = bus->self;
3135
3136 pcie_capability_read_dword(bridge, PCI_EXP_DEVCAP2, &cap);
3137
3138 switch (pci_pcie_type(bridge)) {
3139 /* Ensure switch ports support AtomicOp routing */
3140 case PCI_EXP_TYPE_UPSTREAM:
3141 case PCI_EXP_TYPE_DOWNSTREAM:
3142 if (!(cap & PCI_EXP_DEVCAP2_ATOMIC_ROUTE))
3143 return -EINVAL;
3144 break;
3145
3146 /* Ensure root port supports all the sizes we care about */
3147 case PCI_EXP_TYPE_ROOT_PORT:
3148 if ((cap & cap_mask) != cap_mask)
3149 return -EINVAL;
3150 break;
3151 }
3152
3153 /* Ensure upstream ports don't block AtomicOps on egress */
3154 if (!bridge->has_secondary_link) {
3155 pcie_capability_read_dword(bridge, PCI_EXP_DEVCTL2,
3156 &ctl2);
3157 if (ctl2 & PCI_EXP_DEVCTL2_ATOMIC_EGRESS_BLOCK)
3158 return -EINVAL;
3159 }
3160
3161 bus = bus->parent;
3162 }
3163
3164 pcie_capability_set_word(dev, PCI_EXP_DEVCTL2,
3165 PCI_EXP_DEVCTL2_ATOMIC_REQ);
3166 return 0;
3167}
3168EXPORT_SYMBOL(pci_enable_atomic_ops_to_root);
3169
3170/**
3171 * pci_swizzle_interrupt_pin - swizzle INTx for device behind bridge
3172 * @dev: the PCI device
3173 * @pin: the INTx pin (1=INTA, 2=INTB, 3=INTC, 4=INTD)
3174 *
3175 * Perform INTx swizzling for a device behind one level of bridge. This is
3176 * required by section 9.1 of the PCI-to-PCI bridge specification for devices
3177 * behind bridges on add-in cards. For devices with ARI enabled, the slot
3178 * number is always 0 (see the Implementation Note in section 2.2.8.1 of
3179 * the PCI Express Base Specification, Revision 2.1)
3180 */
3181u8 pci_swizzle_interrupt_pin(const struct pci_dev *dev, u8 pin)
3182{
3183 int slot;
3184
3185 if (pci_ari_enabled(dev->bus))
3186 slot = 0;
3187 else
3188 slot = PCI_SLOT(dev->devfn);
3189
3190 return (((pin - 1) + slot) % 4) + 1;
3191}
3192
3193int pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge)
3194{
3195 u8 pin;
3196
3197 pin = dev->pin;
3198 if (!pin)
3199 return -1;
3200
3201 while (!pci_is_root_bus(dev->bus)) {
3202 pin = pci_swizzle_interrupt_pin(dev, pin);
3203 dev = dev->bus->self;
3204 }
3205 *bridge = dev;
3206 return pin;
3207}
3208
3209/**
3210 * pci_common_swizzle - swizzle INTx all the way to root bridge
3211 * @dev: the PCI device
3212 * @pinp: pointer to the INTx pin value (1=INTA, 2=INTB, 3=INTD, 4=INTD)
3213 *
3214 * Perform INTx swizzling for a device. This traverses through all PCI-to-PCI
3215 * bridges all the way up to a PCI root bus.
3216 */
3217u8 pci_common_swizzle(struct pci_dev *dev, u8 *pinp)
3218{
3219 u8 pin = *pinp;
3220
3221 while (!pci_is_root_bus(dev->bus)) {
3222 pin = pci_swizzle_interrupt_pin(dev, pin);
3223 dev = dev->bus->self;
3224 }
3225 *pinp = pin;
3226 return PCI_SLOT(dev->devfn);
3227}
3228EXPORT_SYMBOL_GPL(pci_common_swizzle);
3229
3230/**
3231 * pci_release_region - Release a PCI bar
3232 * @pdev: PCI device whose resources were previously reserved by pci_request_region
3233 * @bar: BAR to release
3234 *
3235 * Releases the PCI I/O and memory resources previously reserved by a
3236 * successful call to pci_request_region. Call this function only
3237 * after all use of the PCI regions has ceased.
3238 */
3239void pci_release_region(struct pci_dev *pdev, int bar)
3240{
3241 struct pci_devres *dr;
3242
3243 if (pci_resource_len(pdev, bar) == 0)
3244 return;
3245 if (pci_resource_flags(pdev, bar) & IORESOURCE_IO)
3246 release_region(pci_resource_start(pdev, bar),
3247 pci_resource_len(pdev, bar));
3248 else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM)
3249 release_mem_region(pci_resource_start(pdev, bar),
3250 pci_resource_len(pdev, bar));
3251
3252 dr = find_pci_dr(pdev);
3253 if (dr)
3254 dr->region_mask &= ~(1 << bar);
3255}
3256EXPORT_SYMBOL(pci_release_region);
3257
3258/**
3259 * __pci_request_region - Reserved PCI I/O and memory resource
3260 * @pdev: PCI device whose resources are to be reserved
3261 * @bar: BAR to be reserved
3262 * @res_name: Name to be associated with resource.
3263 * @exclusive: whether the region access is exclusive or not
3264 *
3265 * Mark the PCI region associated with PCI device @pdev BR @bar as
3266 * being reserved by owner @res_name. Do not access any
3267 * address inside the PCI regions unless this call returns
3268 * successfully.
3269 *
3270 * If @exclusive is set, then the region is marked so that userspace
3271 * is explicitly not allowed to map the resource via /dev/mem or
3272 * sysfs MMIO access.
3273 *
3274 * Returns 0 on success, or %EBUSY on error. A warning
3275 * message is also printed on failure.
3276 */
3277static int __pci_request_region(struct pci_dev *pdev, int bar,
3278 const char *res_name, int exclusive)
3279{
3280 struct pci_devres *dr;
3281
3282 if (pci_resource_len(pdev, bar) == 0)
3283 return 0;
3284
3285 if (pci_resource_flags(pdev, bar) & IORESOURCE_IO) {
3286 if (!request_region(pci_resource_start(pdev, bar),
3287 pci_resource_len(pdev, bar), res_name))
3288 goto err_out;
3289 } else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM) {
3290 if (!__request_mem_region(pci_resource_start(pdev, bar),
3291 pci_resource_len(pdev, bar), res_name,
3292 exclusive))
3293 goto err_out;
3294 }
3295
3296 dr = find_pci_dr(pdev);
3297 if (dr)
3298 dr->region_mask |= 1 << bar;
3299
3300 return 0;
3301
3302err_out:
3303 pci_warn(pdev, "BAR %d: can't reserve %pR\n", bar,
3304 &pdev->resource[bar]);
3305 return -EBUSY;
3306}
3307
3308/**
3309 * pci_request_region - Reserve PCI I/O and memory resource
3310 * @pdev: PCI device whose resources are to be reserved
3311 * @bar: BAR to be reserved
3312 * @res_name: Name to be associated with resource
3313 *
3314 * Mark the PCI region associated with PCI device @pdev BAR @bar as
3315 * being reserved by owner @res_name. Do not access any
3316 * address inside the PCI regions unless this call returns
3317 * successfully.
3318 *
3319 * Returns 0 on success, or %EBUSY on error. A warning
3320 * message is also printed on failure.
3321 */
3322int pci_request_region(struct pci_dev *pdev, int bar, const char *res_name)
3323{
3324 return __pci_request_region(pdev, bar, res_name, 0);
3325}
3326EXPORT_SYMBOL(pci_request_region);
3327
3328/**
3329 * pci_request_region_exclusive - Reserved PCI I/O and memory resource
3330 * @pdev: PCI device whose resources are to be reserved
3331 * @bar: BAR to be reserved
3332 * @res_name: Name to be associated with resource.
3333 *
3334 * Mark the PCI region associated with PCI device @pdev BR @bar as
3335 * being reserved by owner @res_name. Do not access any
3336 * address inside the PCI regions unless this call returns
3337 * successfully.
3338 *
3339 * Returns 0 on success, or %EBUSY on error. A warning
3340 * message is also printed on failure.
3341 *
3342 * The key difference that _exclusive makes it that userspace is
3343 * explicitly not allowed to map the resource via /dev/mem or
3344 * sysfs.
3345 */
3346int pci_request_region_exclusive(struct pci_dev *pdev, int bar,
3347 const char *res_name)
3348{
3349 return __pci_request_region(pdev, bar, res_name, IORESOURCE_EXCLUSIVE);
3350}
3351EXPORT_SYMBOL(pci_request_region_exclusive);
3352
3353/**
3354 * pci_release_selected_regions - Release selected PCI I/O and memory resources
3355 * @pdev: PCI device whose resources were previously reserved
3356 * @bars: Bitmask of BARs to be released
3357 *
3358 * Release selected PCI I/O and memory resources previously reserved.
3359 * Call this function only after all use of the PCI regions has ceased.
3360 */
3361void pci_release_selected_regions(struct pci_dev *pdev, int bars)
3362{
3363 int i;
3364
3365 for (i = 0; i < 6; i++)
3366 if (bars & (1 << i))
3367 pci_release_region(pdev, i);
3368}
3369EXPORT_SYMBOL(pci_release_selected_regions);
3370
3371static int __pci_request_selected_regions(struct pci_dev *pdev, int bars,
3372 const char *res_name, int excl)
3373{
3374 int i;
3375
3376 for (i = 0; i < 6; i++)
3377 if (bars & (1 << i))
3378 if (__pci_request_region(pdev, i, res_name, excl))
3379 goto err_out;
3380 return 0;
3381
3382err_out:
3383 while (--i >= 0)
3384 if (bars & (1 << i))
3385 pci_release_region(pdev, i);
3386
3387 return -EBUSY;
3388}
3389
3390
3391/**
3392 * pci_request_selected_regions - Reserve selected PCI I/O and memory resources
3393 * @pdev: PCI device whose resources are to be reserved
3394 * @bars: Bitmask of BARs to be requested
3395 * @res_name: Name to be associated with resource
3396 */
3397int pci_request_selected_regions(struct pci_dev *pdev, int bars,
3398 const char *res_name)
3399{
3400 return __pci_request_selected_regions(pdev, bars, res_name, 0);
3401}
3402EXPORT_SYMBOL(pci_request_selected_regions);
3403
3404int pci_request_selected_regions_exclusive(struct pci_dev *pdev, int bars,
3405 const char *res_name)
3406{
3407 return __pci_request_selected_regions(pdev, bars, res_name,
3408 IORESOURCE_EXCLUSIVE);
3409}
3410EXPORT_SYMBOL(pci_request_selected_regions_exclusive);
3411
3412/**
3413 * pci_release_regions - Release reserved PCI I/O and memory resources
3414 * @pdev: PCI device whose resources were previously reserved by pci_request_regions
3415 *
3416 * Releases all PCI I/O and memory resources previously reserved by a
3417 * successful call to pci_request_regions. Call this function only
3418 * after all use of the PCI regions has ceased.
3419 */
3420
3421void pci_release_regions(struct pci_dev *pdev)
3422{
3423 pci_release_selected_regions(pdev, (1 << 6) - 1);
3424}
3425EXPORT_SYMBOL(pci_release_regions);
3426
3427/**
3428 * pci_request_regions - Reserved PCI I/O and memory resources
3429 * @pdev: PCI device whose resources are to be reserved
3430 * @res_name: Name to be associated with resource.
3431 *
3432 * Mark all PCI regions associated with PCI device @pdev as
3433 * being reserved by owner @res_name. Do not access any
3434 * address inside the PCI regions unless this call returns
3435 * successfully.
3436 *
3437 * Returns 0 on success, or %EBUSY on error. A warning
3438 * message is also printed on failure.
3439 */
3440int pci_request_regions(struct pci_dev *pdev, const char *res_name)
3441{
3442 return pci_request_selected_regions(pdev, ((1 << 6) - 1), res_name);
3443}
3444EXPORT_SYMBOL(pci_request_regions);
3445
3446/**
3447 * pci_request_regions_exclusive - Reserved PCI I/O and memory resources
3448 * @pdev: PCI device whose resources are to be reserved
3449 * @res_name: Name to be associated with resource.
3450 *
3451 * Mark all PCI regions associated with PCI device @pdev as
3452 * being reserved by owner @res_name. Do not access any
3453 * address inside the PCI regions unless this call returns
3454 * successfully.
3455 *
3456 * pci_request_regions_exclusive() will mark the region so that
3457 * /dev/mem and the sysfs MMIO access will not be allowed.
3458 *
3459 * Returns 0 on success, or %EBUSY on error. A warning
3460 * message is also printed on failure.
3461 */
3462int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name)
3463{
3464 return pci_request_selected_regions_exclusive(pdev,
3465 ((1 << 6) - 1), res_name);
3466}
3467EXPORT_SYMBOL(pci_request_regions_exclusive);
3468
3469/*
3470 * Record the PCI IO range (expressed as CPU physical address + size).
3471 * Return a negative value if an error has occured, zero otherwise
3472 */
3473int pci_register_io_range(struct fwnode_handle *fwnode, phys_addr_t addr,
3474 resource_size_t size)
3475{
3476 int ret = 0;
3477#ifdef PCI_IOBASE
3478 struct logic_pio_hwaddr *range;
3479
3480 if (!size || addr + size < addr)
3481 return -EINVAL;
3482
3483 range = kzalloc(sizeof(*range), GFP_ATOMIC);
3484 if (!range)
3485 return -ENOMEM;
3486
3487 range->fwnode = fwnode;
3488 range->size = size;
3489 range->hw_start = addr;
3490 range->flags = LOGIC_PIO_CPU_MMIO;
3491
3492 ret = logic_pio_register_range(range);
3493 if (ret)
3494 kfree(range);
3495#endif
3496
3497 return ret;
3498}
3499
3500phys_addr_t pci_pio_to_address(unsigned long pio)
3501{
3502 phys_addr_t address = (phys_addr_t)OF_BAD_ADDR;
3503
3504#ifdef PCI_IOBASE
3505 if (pio >= MMIO_UPPER_LIMIT)
3506 return address;
3507
3508 address = logic_pio_to_hwaddr(pio);
3509#endif
3510
3511 return address;
3512}
3513
3514unsigned long __weak pci_address_to_pio(phys_addr_t address)
3515{
3516#ifdef PCI_IOBASE
3517 return logic_pio_trans_cpuaddr(address);
3518#else
3519 if (address > IO_SPACE_LIMIT)
3520 return (unsigned long)-1;
3521
3522 return (unsigned long) address;
3523#endif
3524}
3525
3526/**
3527 * pci_remap_iospace - Remap the memory mapped I/O space
3528 * @res: Resource describing the I/O space
3529 * @phys_addr: physical address of range to be mapped
3530 *
3531 * Remap the memory mapped I/O space described by the @res
3532 * and the CPU physical address @phys_addr into virtual address space.
3533 * Only architectures that have memory mapped IO functions defined
3534 * (and the PCI_IOBASE value defined) should call this function.
3535 */
3536int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr)
3537{
3538#if defined(PCI_IOBASE) && defined(CONFIG_MMU)
3539 unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start;
3540
3541 if (!(res->flags & IORESOURCE_IO))
3542 return -EINVAL;
3543
3544 if (res->end > IO_SPACE_LIMIT)
3545 return -EINVAL;
3546
3547 return ioremap_page_range(vaddr, vaddr + resource_size(res), phys_addr,
3548 pgprot_device(PAGE_KERNEL));
3549#else
3550 /* this architecture does not have memory mapped I/O space,
3551 so this function should never be called */
3552 WARN_ONCE(1, "This architecture does not support memory mapped I/O\n");
3553 return -ENODEV;
3554#endif
3555}
3556EXPORT_SYMBOL(pci_remap_iospace);
3557
3558/**
3559 * pci_unmap_iospace - Unmap the memory mapped I/O space
3560 * @res: resource to be unmapped
3561 *
3562 * Unmap the CPU virtual address @res from virtual address space.
3563 * Only architectures that have memory mapped IO functions defined
3564 * (and the PCI_IOBASE value defined) should call this function.
3565 */
3566void pci_unmap_iospace(struct resource *res)
3567{
3568#if defined(PCI_IOBASE) && defined(CONFIG_MMU)
3569 unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start;
3570
3571 unmap_kernel_range(vaddr, resource_size(res));
3572#endif
3573}
3574EXPORT_SYMBOL(pci_unmap_iospace);
3575
3576/**
3577 * devm_pci_remap_cfgspace - Managed pci_remap_cfgspace()
3578 * @dev: Generic device to remap IO address for
3579 * @offset: Resource address to map
3580 * @size: Size of map
3581 *
3582 * Managed pci_remap_cfgspace(). Map is automatically unmapped on driver
3583 * detach.
3584 */
3585void __iomem *devm_pci_remap_cfgspace(struct device *dev,
3586 resource_size_t offset,
3587 resource_size_t size)
3588{
3589 void __iomem **ptr, *addr;
3590
3591 ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL);
3592 if (!ptr)
3593 return NULL;
3594
3595 addr = pci_remap_cfgspace(offset, size);
3596 if (addr) {
3597 *ptr = addr;
3598 devres_add(dev, ptr);
3599 } else
3600 devres_free(ptr);
3601
3602 return addr;
3603}
3604EXPORT_SYMBOL(devm_pci_remap_cfgspace);
3605
3606/**
3607 * devm_pci_remap_cfg_resource - check, request region and ioremap cfg resource
3608 * @dev: generic device to handle the resource for
3609 * @res: configuration space resource to be handled
3610 *
3611 * Checks that a resource is a valid memory region, requests the memory
3612 * region and ioremaps with pci_remap_cfgspace() API that ensures the
3613 * proper PCI configuration space memory attributes are guaranteed.
3614 *
3615 * All operations are managed and will be undone on driver detach.
3616 *
3617 * Returns a pointer to the remapped memory or an ERR_PTR() encoded error code
3618 * on failure. Usage example::
3619 *
3620 * res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
3621 * base = devm_pci_remap_cfg_resource(&pdev->dev, res);
3622 * if (IS_ERR(base))
3623 * return PTR_ERR(base);
3624 */
3625void __iomem *devm_pci_remap_cfg_resource(struct device *dev,
3626 struct resource *res)
3627{
3628 resource_size_t size;
3629 const char *name;
3630 void __iomem *dest_ptr;
3631
3632 BUG_ON(!dev);
3633
3634 if (!res || resource_type(res) != IORESOURCE_MEM) {
3635 dev_err(dev, "invalid resource\n");
3636 return IOMEM_ERR_PTR(-EINVAL);
3637 }
3638
3639 size = resource_size(res);
3640 name = res->name ?: dev_name(dev);
3641
3642 if (!devm_request_mem_region(dev, res->start, size, name)) {
3643 dev_err(dev, "can't request region for resource %pR\n", res);
3644 return IOMEM_ERR_PTR(-EBUSY);
3645 }
3646
3647 dest_ptr = devm_pci_remap_cfgspace(dev, res->start, size);
3648 if (!dest_ptr) {
3649 dev_err(dev, "ioremap failed for resource %pR\n", res);
3650 devm_release_mem_region(dev, res->start, size);
3651 dest_ptr = IOMEM_ERR_PTR(-ENOMEM);
3652 }
3653
3654 return dest_ptr;
3655}
3656EXPORT_SYMBOL(devm_pci_remap_cfg_resource);
3657
3658static void __pci_set_master(struct pci_dev *dev, bool enable)
3659{
3660 u16 old_cmd, cmd;
3661
3662 pci_read_config_word(dev, PCI_COMMAND, &old_cmd);
3663 if (enable)
3664 cmd = old_cmd | PCI_COMMAND_MASTER;
3665 else
3666 cmd = old_cmd & ~PCI_COMMAND_MASTER;
3667 if (cmd != old_cmd) {
3668 pci_dbg(dev, "%s bus mastering\n",
3669 enable ? "enabling" : "disabling");
3670 pci_write_config_word(dev, PCI_COMMAND, cmd);
3671 }
3672 dev->is_busmaster = enable;
3673}
3674
3675/**
3676 * pcibios_setup - process "pci=" kernel boot arguments
3677 * @str: string used to pass in "pci=" kernel boot arguments
3678 *
3679 * Process kernel boot arguments. This is the default implementation.
3680 * Architecture specific implementations can override this as necessary.
3681 */
3682char * __weak __init pcibios_setup(char *str)
3683{
3684 return str;
3685}
3686
3687/**
3688 * pcibios_set_master - enable PCI bus-mastering for device dev
3689 * @dev: the PCI device to enable
3690 *
3691 * Enables PCI bus-mastering for the device. This is the default
3692 * implementation. Architecture specific implementations can override
3693 * this if necessary.
3694 */
3695void __weak pcibios_set_master(struct pci_dev *dev)
3696{
3697 u8 lat;
3698
3699 /* The latency timer doesn't apply to PCIe (either Type 0 or Type 1) */
3700 if (pci_is_pcie(dev))
3701 return;
3702
3703 pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat);
3704 if (lat < 16)
3705 lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency;
3706 else if (lat > pcibios_max_latency)
3707 lat = pcibios_max_latency;
3708 else
3709 return;
3710
3711 pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat);
3712}
3713
3714/**
3715 * pci_set_master - enables bus-mastering for device dev
3716 * @dev: the PCI device to enable
3717 *
3718 * Enables bus-mastering on the device and calls pcibios_set_master()
3719 * to do the needed arch specific settings.
3720 */
3721void pci_set_master(struct pci_dev *dev)
3722{
3723 __pci_set_master(dev, true);
3724 pcibios_set_master(dev);
3725}
3726EXPORT_SYMBOL(pci_set_master);
3727
3728/**
3729 * pci_clear_master - disables bus-mastering for device dev
3730 * @dev: the PCI device to disable
3731 */
3732void pci_clear_master(struct pci_dev *dev)
3733{
3734 __pci_set_master(dev, false);
3735}
3736EXPORT_SYMBOL(pci_clear_master);
3737
3738/**
3739 * pci_set_cacheline_size - ensure the CACHE_LINE_SIZE register is programmed
3740 * @dev: the PCI device for which MWI is to be enabled
3741 *
3742 * Helper function for pci_set_mwi.
3743 * Originally copied from drivers/net/acenic.c.
3744 * Copyright 1998-2001 by Jes Sorensen, <jes@trained-monkey.org>.
3745 *
3746 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
3747 */
3748int pci_set_cacheline_size(struct pci_dev *dev)
3749{
3750 u8 cacheline_size;
3751
3752 if (!pci_cache_line_size)
3753 return -EINVAL;
3754
3755 /* Validate current setting: the PCI_CACHE_LINE_SIZE must be
3756 equal to or multiple of the right value. */
3757 pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
3758 if (cacheline_size >= pci_cache_line_size &&
3759 (cacheline_size % pci_cache_line_size) == 0)
3760 return 0;
3761
3762 /* Write the correct value. */
3763 pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, pci_cache_line_size);
3764 /* Read it back. */
3765 pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
3766 if (cacheline_size == pci_cache_line_size)
3767 return 0;
3768
3769 pci_printk(KERN_DEBUG, dev, "cache line size of %d is not supported\n",
3770 pci_cache_line_size << 2);
3771
3772 return -EINVAL;
3773}
3774EXPORT_SYMBOL_GPL(pci_set_cacheline_size);
3775
3776/**
3777 * pci_set_mwi - enables memory-write-invalidate PCI transaction
3778 * @dev: the PCI device for which MWI is enabled
3779 *
3780 * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND.
3781 *
3782 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
3783 */
3784int pci_set_mwi(struct pci_dev *dev)
3785{
3786#ifdef PCI_DISABLE_MWI
3787 return 0;
3788#else
3789 int rc;
3790 u16 cmd;
3791
3792 rc = pci_set_cacheline_size(dev);
3793 if (rc)
3794 return rc;
3795
3796 pci_read_config_word(dev, PCI_COMMAND, &cmd);
3797 if (!(cmd & PCI_COMMAND_INVALIDATE)) {
3798 pci_dbg(dev, "enabling Mem-Wr-Inval\n");
3799 cmd |= PCI_COMMAND_INVALIDATE;
3800 pci_write_config_word(dev, PCI_COMMAND, cmd);
3801 }
3802 return 0;
3803#endif
3804}
3805EXPORT_SYMBOL(pci_set_mwi);
3806
3807/**
3808 * pcim_set_mwi - a device-managed pci_set_mwi()
3809 * @dev: the PCI device for which MWI is enabled
3810 *
3811 * Managed pci_set_mwi().
3812 *
3813 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
3814 */
3815int pcim_set_mwi(struct pci_dev *dev)
3816{
3817 struct pci_devres *dr;
3818
3819 dr = find_pci_dr(dev);
3820 if (!dr)
3821 return -ENOMEM;
3822
3823 dr->mwi = 1;
3824 return pci_set_mwi(dev);
3825}
3826EXPORT_SYMBOL(pcim_set_mwi);
3827
3828/**
3829 * pci_try_set_mwi - enables memory-write-invalidate PCI transaction
3830 * @dev: the PCI device for which MWI is enabled
3831 *
3832 * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND.
3833 * Callers are not required to check the return value.
3834 *
3835 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
3836 */
3837int pci_try_set_mwi(struct pci_dev *dev)
3838{
3839#ifdef PCI_DISABLE_MWI
3840 return 0;
3841#else
3842 return pci_set_mwi(dev);
3843#endif
3844}
3845EXPORT_SYMBOL(pci_try_set_mwi);
3846
3847/**
3848 * pci_clear_mwi - disables Memory-Write-Invalidate for device dev
3849 * @dev: the PCI device to disable
3850 *
3851 * Disables PCI Memory-Write-Invalidate transaction on the device
3852 */
3853void pci_clear_mwi(struct pci_dev *dev)
3854{
3855#ifndef PCI_DISABLE_MWI
3856 u16 cmd;
3857
3858 pci_read_config_word(dev, PCI_COMMAND, &cmd);
3859 if (cmd & PCI_COMMAND_INVALIDATE) {
3860 cmd &= ~PCI_COMMAND_INVALIDATE;
3861 pci_write_config_word(dev, PCI_COMMAND, cmd);
3862 }
3863#endif
3864}
3865EXPORT_SYMBOL(pci_clear_mwi);
3866
3867/**
3868 * pci_intx - enables/disables PCI INTx for device dev
3869 * @pdev: the PCI device to operate on
3870 * @enable: boolean: whether to enable or disable PCI INTx
3871 *
3872 * Enables/disables PCI INTx for device dev
3873 */
3874void pci_intx(struct pci_dev *pdev, int enable)
3875{
3876 u16 pci_command, new;
3877
3878 pci_read_config_word(pdev, PCI_COMMAND, &pci_command);
3879
3880 if (enable)
3881 new = pci_command & ~PCI_COMMAND_INTX_DISABLE;
3882 else
3883 new = pci_command | PCI_COMMAND_INTX_DISABLE;
3884
3885 if (new != pci_command) {
3886 struct pci_devres *dr;
3887
3888 pci_write_config_word(pdev, PCI_COMMAND, new);
3889
3890 dr = find_pci_dr(pdev);
3891 if (dr && !dr->restore_intx) {
3892 dr->restore_intx = 1;
3893 dr->orig_intx = !enable;
3894 }
3895 }
3896}
3897EXPORT_SYMBOL_GPL(pci_intx);
3898
3899static bool pci_check_and_set_intx_mask(struct pci_dev *dev, bool mask)
3900{
3901 struct pci_bus *bus = dev->bus;
3902 bool mask_updated = true;
3903 u32 cmd_status_dword;
3904 u16 origcmd, newcmd;
3905 unsigned long flags;
3906 bool irq_pending;
3907
3908 /*
3909 * We do a single dword read to retrieve both command and status.
3910 * Document assumptions that make this possible.
3911 */
3912 BUILD_BUG_ON(PCI_COMMAND % 4);
3913 BUILD_BUG_ON(PCI_COMMAND + 2 != PCI_STATUS);
3914
3915 raw_spin_lock_irqsave(&pci_lock, flags);
3916
3917 bus->ops->read(bus, dev->devfn, PCI_COMMAND, 4, &cmd_status_dword);
3918
3919 irq_pending = (cmd_status_dword >> 16) & PCI_STATUS_INTERRUPT;
3920
3921 /*
3922 * Check interrupt status register to see whether our device
3923 * triggered the interrupt (when masking) or the next IRQ is
3924 * already pending (when unmasking).
3925 */
3926 if (mask != irq_pending) {
3927 mask_updated = false;
3928 goto done;
3929 }
3930
3931 origcmd = cmd_status_dword;
3932 newcmd = origcmd & ~PCI_COMMAND_INTX_DISABLE;
3933 if (mask)
3934 newcmd |= PCI_COMMAND_INTX_DISABLE;
3935 if (newcmd != origcmd)
3936 bus->ops->write(bus, dev->devfn, PCI_COMMAND, 2, newcmd);
3937
3938done:
3939 raw_spin_unlock_irqrestore(&pci_lock, flags);
3940
3941 return mask_updated;
3942}
3943
3944/**
3945 * pci_check_and_mask_intx - mask INTx on pending interrupt
3946 * @dev: the PCI device to operate on
3947 *
3948 * Check if the device dev has its INTx line asserted, mask it and
3949 * return true in that case. False is returned if no interrupt was
3950 * pending.
3951 */
3952bool pci_check_and_mask_intx(struct pci_dev *dev)
3953{
3954 return pci_check_and_set_intx_mask(dev, true);
3955}
3956EXPORT_SYMBOL_GPL(pci_check_and_mask_intx);
3957
3958/**
3959 * pci_check_and_unmask_intx - unmask INTx if no interrupt is pending
3960 * @dev: the PCI device to operate on
3961 *
3962 * Check if the device dev has its INTx line asserted, unmask it if not
3963 * and return true. False is returned and the mask remains active if
3964 * there was still an interrupt pending.
3965 */
3966bool pci_check_and_unmask_intx(struct pci_dev *dev)
3967{
3968 return pci_check_and_set_intx_mask(dev, false);
3969}
3970EXPORT_SYMBOL_GPL(pci_check_and_unmask_intx);
3971
3972/**
3973 * pci_wait_for_pending_transaction - waits for pending transaction
3974 * @dev: the PCI device to operate on
3975 *
3976 * Return 0 if transaction is pending 1 otherwise.
3977 */
3978int pci_wait_for_pending_transaction(struct pci_dev *dev)
3979{
3980 if (!pci_is_pcie(dev))
3981 return 1;
3982
3983 return pci_wait_for_pending(dev, pci_pcie_cap(dev) + PCI_EXP_DEVSTA,
3984 PCI_EXP_DEVSTA_TRPND);
3985}
3986EXPORT_SYMBOL(pci_wait_for_pending_transaction);
3987
3988static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout)
3989{
3990 int delay = 1;
3991 u32 id;
3992
3993 /*
3994 * After reset, the device should not silently discard config
3995 * requests, but it may still indicate that it needs more time by
3996 * responding to them with CRS completions. The Root Port will
3997 * generally synthesize ~0 data to complete the read (except when
3998 * CRS SV is enabled and the read was for the Vendor ID; in that
3999 * case it synthesizes 0x0001 data).
4000 *
4001 * Wait for the device to return a non-CRS completion. Read the
4002 * Command register instead of Vendor ID so we don't have to
4003 * contend with the CRS SV value.
4004 */
4005 pci_read_config_dword(dev, PCI_COMMAND, &id);
4006 while (id == ~0) {
4007 if (delay > timeout) {
4008 pci_warn(dev, "not ready %dms after %s; giving up\n",
4009 delay - 1, reset_type);
4010 return -ENOTTY;
4011 }
4012
4013 if (delay > 1000)
4014 pci_info(dev, "not ready %dms after %s; waiting\n",
4015 delay - 1, reset_type);
4016
4017 msleep(delay);
4018 delay *= 2;
4019 pci_read_config_dword(dev, PCI_COMMAND, &id);
4020 }
4021
4022 if (delay > 1000)
4023 pci_info(dev, "ready %dms after %s\n", delay - 1,
4024 reset_type);
4025
4026 return 0;
4027}
4028
4029/**
4030 * pcie_has_flr - check if a device supports function level resets
4031 * @dev: device to check
4032 *
4033 * Returns true if the device advertises support for PCIe function level
4034 * resets.
4035 */
4036static bool pcie_has_flr(struct pci_dev *dev)
4037{
4038 u32 cap;
4039
4040 if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
4041 return false;
4042
4043 pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap);
4044 return cap & PCI_EXP_DEVCAP_FLR;
4045}
4046
4047/**
4048 * pcie_flr - initiate a PCIe function level reset
4049 * @dev: device to reset
4050 *
4051 * Initiate a function level reset on @dev. The caller should ensure the
4052 * device supports FLR before calling this function, e.g. by using the
4053 * pcie_has_flr() helper.
4054 */
4055int pcie_flr(struct pci_dev *dev)
4056{
4057 if (!pci_wait_for_pending_transaction(dev))
4058 pci_err(dev, "timed out waiting for pending transaction; performing function level reset anyway\n");
4059
4060 pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR);
4061
4062 /*
4063 * Per PCIe r4.0, sec 6.6.2, a device must complete an FLR within
4064 * 100ms, but may silently discard requests while the FLR is in
4065 * progress. Wait 100ms before trying to access the device.
4066 */
4067 msleep(100);
4068
4069 return pci_dev_wait(dev, "FLR", PCIE_RESET_READY_POLL_MS);
4070}
4071EXPORT_SYMBOL_GPL(pcie_flr);
4072
4073static int pci_af_flr(struct pci_dev *dev, int probe)
4074{
4075 int pos;
4076 u8 cap;
4077
4078 pos = pci_find_capability(dev, PCI_CAP_ID_AF);
4079 if (!pos)
4080 return -ENOTTY;
4081
4082 if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
4083 return -ENOTTY;
4084
4085 pci_read_config_byte(dev, pos + PCI_AF_CAP, &cap);
4086 if (!(cap & PCI_AF_CAP_TP) || !(cap & PCI_AF_CAP_FLR))
4087 return -ENOTTY;
4088
4089 if (probe)
4090 return 0;
4091
4092 /*
4093 * Wait for Transaction Pending bit to clear. A word-aligned test
4094 * is used, so we use the conrol offset rather than status and shift
4095 * the test bit to match.
4096 */
4097 if (!pci_wait_for_pending(dev, pos + PCI_AF_CTRL,
4098 PCI_AF_STATUS_TP << 8))
4099 pci_err(dev, "timed out waiting for pending transaction; performing AF function level reset anyway\n");
4100
4101 pci_write_config_byte(dev, pos + PCI_AF_CTRL, PCI_AF_CTRL_FLR);
4102
4103 /*
4104 * Per Advanced Capabilities for Conventional PCI ECN, 13 April 2006,
4105 * updated 27 July 2006; a device must complete an FLR within
4106 * 100ms, but may silently discard requests while the FLR is in
4107 * progress. Wait 100ms before trying to access the device.
4108 */
4109 msleep(100);
4110
4111 return pci_dev_wait(dev, "AF_FLR", PCIE_RESET_READY_POLL_MS);
4112}
4113
4114/**
4115 * pci_pm_reset - Put device into PCI_D3 and back into PCI_D0.
4116 * @dev: Device to reset.
4117 * @probe: If set, only check if the device can be reset this way.
4118 *
4119 * If @dev supports native PCI PM and its PCI_PM_CTRL_NO_SOFT_RESET flag is
4120 * unset, it will be reinitialized internally when going from PCI_D3hot to
4121 * PCI_D0. If that's the case and the device is not in a low-power state
4122 * already, force it into PCI_D3hot and back to PCI_D0, causing it to be reset.
4123 *
4124 * NOTE: This causes the caller to sleep for twice the device power transition
4125 * cooldown period, which for the D0->D3hot and D3hot->D0 transitions is 10 ms
4126 * by default (i.e. unless the @dev's d3_delay field has a different value).
4127 * Moreover, only devices in D0 can be reset by this function.
4128 */
4129static int pci_pm_reset(struct pci_dev *dev, int probe)
4130{
4131 u16 csr;
4132
4133 if (!dev->pm_cap || dev->dev_flags & PCI_DEV_FLAGS_NO_PM_RESET)
4134 return -ENOTTY;
4135
4136 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &csr);
4137 if (csr & PCI_PM_CTRL_NO_SOFT_RESET)
4138 return -ENOTTY;
4139
4140 if (probe)
4141 return 0;
4142
4143 if (dev->current_state != PCI_D0)
4144 return -EINVAL;
4145
4146 csr &= ~PCI_PM_CTRL_STATE_MASK;
4147 csr |= PCI_D3hot;
4148 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);
4149 pci_dev_d3_sleep(dev);
4150
4151 csr &= ~PCI_PM_CTRL_STATE_MASK;
4152 csr |= PCI_D0;
4153 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);
4154 pci_dev_d3_sleep(dev);
4155
4156 return pci_dev_wait(dev, "PM D3->D0", PCIE_RESET_READY_POLL_MS);
4157}
4158
4159void pci_reset_secondary_bus(struct pci_dev *dev)
4160{
4161 u16 ctrl;
4162
4163 pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &ctrl);
4164 ctrl |= PCI_BRIDGE_CTL_BUS_RESET;
4165 pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl);
4166
4167 /*
4168 * PCI spec v3.0 7.6.4.2 requires minimum Trst of 1ms. Double
4169 * this to 2ms to ensure that we meet the minimum requirement.
4170 */
4171 msleep(2);
4172
4173 ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET;
4174 pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl);
4175
4176 /*
4177 * Trhfa for conventional PCI is 2^25 clock cycles.
4178 * Assuming a minimum 33MHz clock this results in a 1s
4179 * delay before we can consider subordinate devices to
4180 * be re-initialized. PCIe has some ways to shorten this,
4181 * but we don't make use of them yet.
4182 */
4183 ssleep(1);
4184}
4185
4186void __weak pcibios_reset_secondary_bus(struct pci_dev *dev)
4187{
4188 pci_reset_secondary_bus(dev);
4189}
4190
4191/**
4192 * pci_reset_bridge_secondary_bus - Reset the secondary bus on a PCI bridge.
4193 * @dev: Bridge device
4194 *
4195 * Use the bridge control register to assert reset on the secondary bus.
4196 * Devices on the secondary bus are left in power-on state.
4197 */
4198int pci_reset_bridge_secondary_bus(struct pci_dev *dev)
4199{
4200 pcibios_reset_secondary_bus(dev);
4201
4202 return pci_dev_wait(dev, "bus reset", PCIE_RESET_READY_POLL_MS);
4203}
4204EXPORT_SYMBOL_GPL(pci_reset_bridge_secondary_bus);
4205
4206static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
4207{
4208 struct pci_dev *pdev;
4209
4210 if (pci_is_root_bus(dev->bus) || dev->subordinate ||
4211 !dev->bus->self || dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)
4212 return -ENOTTY;
4213
4214 list_for_each_entry(pdev, &dev->bus->devices, bus_list)
4215 if (pdev != dev)
4216 return -ENOTTY;
4217
4218 if (probe)
4219 return 0;
4220
4221 pci_reset_bridge_secondary_bus(dev->bus->self);
4222
4223 return 0;
4224}
4225
4226static int pci_reset_hotplug_slot(struct hotplug_slot *hotplug, int probe)
4227{
4228 int rc = -ENOTTY;
4229
4230 if (!hotplug || !try_module_get(hotplug->ops->owner))
4231 return rc;
4232
4233 if (hotplug->ops->reset_slot)
4234 rc = hotplug->ops->reset_slot(hotplug, probe);
4235
4236 module_put(hotplug->ops->owner);
4237
4238 return rc;
4239}
4240
4241static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe)
4242{
4243 struct pci_dev *pdev;
4244
4245 if (dev->subordinate || !dev->slot ||
4246 dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)
4247 return -ENOTTY;
4248
4249 list_for_each_entry(pdev, &dev->bus->devices, bus_list)
4250 if (pdev != dev && pdev->slot == dev->slot)
4251 return -ENOTTY;
4252
4253 return pci_reset_hotplug_slot(dev->slot->hotplug, probe);
4254}
4255
4256static void pci_dev_lock(struct pci_dev *dev)
4257{
4258 pci_cfg_access_lock(dev);
4259 /* block PM suspend, driver probe, etc. */
4260 device_lock(&dev->dev);
4261}
4262
4263/* Return 1 on successful lock, 0 on contention */
4264static int pci_dev_trylock(struct pci_dev *dev)
4265{
4266 if (pci_cfg_access_trylock(dev)) {
4267 if (device_trylock(&dev->dev))
4268 return 1;
4269 pci_cfg_access_unlock(dev);
4270 }
4271
4272 return 0;
4273}
4274
4275static void pci_dev_unlock(struct pci_dev *dev)
4276{
4277 device_unlock(&dev->dev);
4278 pci_cfg_access_unlock(dev);
4279}
4280
4281static void pci_dev_save_and_disable(struct pci_dev *dev)
4282{
4283 const struct pci_error_handlers *err_handler =
4284 dev->driver ? dev->driver->err_handler : NULL;
4285
4286 /*
4287 * dev->driver->err_handler->reset_prepare() is protected against
4288 * races with ->remove() by the device lock, which must be held by
4289 * the caller.
4290 */
4291 if (err_handler && err_handler->reset_prepare)
4292 err_handler->reset_prepare(dev);
4293
4294 /*
4295 * Wake-up device prior to save. PM registers default to D0 after
4296 * reset and a simple register restore doesn't reliably return
4297 * to a non-D0 state anyway.
4298 */
4299 pci_set_power_state(dev, PCI_D0);
4300
4301 pci_save_state(dev);
4302 /*
4303 * Disable the device by clearing the Command register, except for
4304 * INTx-disable which is set. This not only disables MMIO and I/O port
4305 * BARs, but also prevents the device from being Bus Master, preventing
4306 * DMA from the device including MSI/MSI-X interrupts. For PCI 2.3
4307 * compliant devices, INTx-disable prevents legacy interrupts.
4308 */
4309 pci_write_config_word(dev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
4310}
4311
4312static void pci_dev_restore(struct pci_dev *dev)
4313{
4314 const struct pci_error_handlers *err_handler =
4315 dev->driver ? dev->driver->err_handler : NULL;
4316
4317 pci_restore_state(dev);
4318
4319 /*
4320 * dev->driver->err_handler->reset_done() is protected against
4321 * races with ->remove() by the device lock, which must be held by
4322 * the caller.
4323 */
4324 if (err_handler && err_handler->reset_done)
4325 err_handler->reset_done(dev);
4326}
4327
4328/**
4329 * __pci_reset_function_locked - reset a PCI device function while holding
4330 * the @dev mutex lock.
4331 * @dev: PCI device to reset
4332 *
4333 * Some devices allow an individual function to be reset without affecting
4334 * other functions in the same device. The PCI device must be responsive
4335 * to PCI config space in order to use this function.
4336 *
4337 * The device function is presumed to be unused and the caller is holding
4338 * the device mutex lock when this function is called.
4339 * Resetting the device will make the contents of PCI configuration space
4340 * random, so any caller of this must be prepared to reinitialise the
4341 * device including MSI, bus mastering, BARs, decoding IO and memory spaces,
4342 * etc.
4343 *
4344 * Returns 0 if the device function was successfully reset or negative if the
4345 * device doesn't support resetting a single function.
4346 */
4347int __pci_reset_function_locked(struct pci_dev *dev)
4348{
4349 int rc;
4350
4351 might_sleep();
4352
4353 /*
4354 * A reset method returns -ENOTTY if it doesn't support this device
4355 * and we should try the next method.
4356 *
4357 * If it returns 0 (success), we're finished. If it returns any
4358 * other error, we're also finished: this indicates that further
4359 * reset mechanisms might be broken on the device.
4360 */
4361 rc = pci_dev_specific_reset(dev, 0);
4362 if (rc != -ENOTTY)
4363 return rc;
4364 if (pcie_has_flr(dev)) {
4365 rc = pcie_flr(dev);
4366 if (rc != -ENOTTY)
4367 return rc;
4368 }
4369 rc = pci_af_flr(dev, 0);
4370 if (rc != -ENOTTY)
4371 return rc;
4372 rc = pci_pm_reset(dev, 0);
4373 if (rc != -ENOTTY)
4374 return rc;
4375 rc = pci_dev_reset_slot_function(dev, 0);
4376 if (rc != -ENOTTY)
4377 return rc;
4378 return pci_parent_bus_reset(dev, 0);
4379}
4380EXPORT_SYMBOL_GPL(__pci_reset_function_locked);
4381
4382/**
4383 * pci_probe_reset_function - check whether the device can be safely reset
4384 * @dev: PCI device to reset
4385 *
4386 * Some devices allow an individual function to be reset without affecting
4387 * other functions in the same device. The PCI device must be responsive
4388 * to PCI config space in order to use this function.
4389 *
4390 * Returns 0 if the device function can be reset or negative if the
4391 * device doesn't support resetting a single function.
4392 */
4393int pci_probe_reset_function(struct pci_dev *dev)
4394{
4395 int rc;
4396
4397 might_sleep();
4398
4399 rc = pci_dev_specific_reset(dev, 1);
4400 if (rc != -ENOTTY)
4401 return rc;
4402 if (pcie_has_flr(dev))
4403 return 0;
4404 rc = pci_af_flr(dev, 1);
4405 if (rc != -ENOTTY)
4406 return rc;
4407 rc = pci_pm_reset(dev, 1);
4408 if (rc != -ENOTTY)
4409 return rc;
4410 rc = pci_dev_reset_slot_function(dev, 1);
4411 if (rc != -ENOTTY)
4412 return rc;
4413
4414 return pci_parent_bus_reset(dev, 1);
4415}
4416
4417/**
4418 * pci_reset_function - quiesce and reset a PCI device function
4419 * @dev: PCI device to reset
4420 *
4421 * Some devices allow an individual function to be reset without affecting
4422 * other functions in the same device. The PCI device must be responsive
4423 * to PCI config space in order to use this function.
4424 *
4425 * This function does not just reset the PCI portion of a device, but
4426 * clears all the state associated with the device. This function differs
4427 * from __pci_reset_function_locked() in that it saves and restores device state
4428 * over the reset and takes the PCI device lock.
4429 *
4430 * Returns 0 if the device function was successfully reset or negative if the
4431 * device doesn't support resetting a single function.
4432 */
4433int pci_reset_function(struct pci_dev *dev)
4434{
4435 int rc;
4436
4437 if (!dev->reset_fn)
4438 return -ENOTTY;
4439
4440 pci_dev_lock(dev);
4441 pci_dev_save_and_disable(dev);
4442
4443 rc = __pci_reset_function_locked(dev);
4444
4445 pci_dev_restore(dev);
4446 pci_dev_unlock(dev);
4447
4448 return rc;
4449}
4450EXPORT_SYMBOL_GPL(pci_reset_function);
4451
4452/**
4453 * pci_reset_function_locked - quiesce and reset a PCI device function
4454 * @dev: PCI device to reset
4455 *
4456 * Some devices allow an individual function to be reset without affecting
4457 * other functions in the same device. The PCI device must be responsive
4458 * to PCI config space in order to use this function.
4459 *
4460 * This function does not just reset the PCI portion of a device, but
4461 * clears all the state associated with the device. This function differs
4462 * from __pci_reset_function_locked() in that it saves and restores device state
4463 * over the reset. It also differs from pci_reset_function() in that it
4464 * requires the PCI device lock to be held.
4465 *
4466 * Returns 0 if the device function was successfully reset or negative if the
4467 * device doesn't support resetting a single function.
4468 */
4469int pci_reset_function_locked(struct pci_dev *dev)
4470{
4471 int rc;
4472
4473 if (!dev->reset_fn)
4474 return -ENOTTY;
4475
4476 pci_dev_save_and_disable(dev);
4477
4478 rc = __pci_reset_function_locked(dev);
4479
4480 pci_dev_restore(dev);
4481
4482 return rc;
4483}
4484EXPORT_SYMBOL_GPL(pci_reset_function_locked);
4485
4486/**
4487 * pci_try_reset_function - quiesce and reset a PCI device function
4488 * @dev: PCI device to reset
4489 *
4490 * Same as above, except return -EAGAIN if unable to lock device.
4491 */
4492int pci_try_reset_function(struct pci_dev *dev)
4493{
4494 int rc;
4495
4496 if (!dev->reset_fn)
4497 return -ENOTTY;
4498
4499 if (!pci_dev_trylock(dev))
4500 return -EAGAIN;
4501
4502 pci_dev_save_and_disable(dev);
4503 rc = __pci_reset_function_locked(dev);
4504 pci_dev_restore(dev);
4505 pci_dev_unlock(dev);
4506
4507 return rc;
4508}
4509EXPORT_SYMBOL_GPL(pci_try_reset_function);
4510
4511/* Do any devices on or below this bus prevent a bus reset? */
4512static bool pci_bus_resetable(struct pci_bus *bus)
4513{
4514 struct pci_dev *dev;
4515
4516
4517 if (bus->self && (bus->self->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET))
4518 return false;
4519
4520 list_for_each_entry(dev, &bus->devices, bus_list) {
4521 if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET ||
4522 (dev->subordinate && !pci_bus_resetable(dev->subordinate)))
4523 return false;
4524 }
4525
4526 return true;
4527}
4528
4529/* Lock devices from the top of the tree down */
4530static void pci_bus_lock(struct pci_bus *bus)
4531{
4532 struct pci_dev *dev;
4533
4534 list_for_each_entry(dev, &bus->devices, bus_list) {
4535 pci_dev_lock(dev);
4536 if (dev->subordinate)
4537 pci_bus_lock(dev->subordinate);
4538 }
4539}
4540
4541/* Unlock devices from the bottom of the tree up */
4542static void pci_bus_unlock(struct pci_bus *bus)
4543{
4544 struct pci_dev *dev;
4545
4546 list_for_each_entry(dev, &bus->devices, bus_list) {
4547 if (dev->subordinate)
4548 pci_bus_unlock(dev->subordinate);
4549 pci_dev_unlock(dev);
4550 }
4551}
4552
4553/* Return 1 on successful lock, 0 on contention */
4554static int pci_bus_trylock(struct pci_bus *bus)
4555{
4556 struct pci_dev *dev;
4557
4558 list_for_each_entry(dev, &bus->devices, bus_list) {
4559 if (!pci_dev_trylock(dev))
4560 goto unlock;
4561 if (dev->subordinate) {
4562 if (!pci_bus_trylock(dev->subordinate)) {
4563 pci_dev_unlock(dev);
4564 goto unlock;
4565 }
4566 }
4567 }
4568 return 1;
4569
4570unlock:
4571 list_for_each_entry_continue_reverse(dev, &bus->devices, bus_list) {
4572 if (dev->subordinate)
4573 pci_bus_unlock(dev->subordinate);
4574 pci_dev_unlock(dev);
4575 }
4576 return 0;
4577}
4578
4579/* Do any devices on or below this slot prevent a bus reset? */
4580static bool pci_slot_resetable(struct pci_slot *slot)
4581{
4582 struct pci_dev *dev;
4583
4584 if (slot->bus->self &&
4585 (slot->bus->self->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET))
4586 return false;
4587
4588 list_for_each_entry(dev, &slot->bus->devices, bus_list) {
4589 if (!dev->slot || dev->slot != slot)
4590 continue;
4591 if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET ||
4592 (dev->subordinate && !pci_bus_resetable(dev->subordinate)))
4593 return false;
4594 }
4595
4596 return true;
4597}
4598
4599/* Lock devices from the top of the tree down */
4600static void pci_slot_lock(struct pci_slot *slot)
4601{
4602 struct pci_dev *dev;
4603
4604 list_for_each_entry(dev, &slot->bus->devices, bus_list) {
4605 if (!dev->slot || dev->slot != slot)
4606 continue;
4607 pci_dev_lock(dev);
4608 if (dev->subordinate)
4609 pci_bus_lock(dev->subordinate);
4610 }
4611}
4612
4613/* Unlock devices from the bottom of the tree up */
4614static void pci_slot_unlock(struct pci_slot *slot)
4615{
4616 struct pci_dev *dev;
4617
4618 list_for_each_entry(dev, &slot->bus->devices, bus_list) {
4619 if (!dev->slot || dev->slot != slot)
4620 continue;
4621 if (dev->subordinate)
4622 pci_bus_unlock(dev->subordinate);
4623 pci_dev_unlock(dev);
4624 }
4625}
4626
4627/* Return 1 on successful lock, 0 on contention */
4628static int pci_slot_trylock(struct pci_slot *slot)
4629{
4630 struct pci_dev *dev;
4631
4632 list_for_each_entry(dev, &slot->bus->devices, bus_list) {
4633 if (!dev->slot || dev->slot != slot)
4634 continue;
4635 if (!pci_dev_trylock(dev))
4636 goto unlock;
4637 if (dev->subordinate) {
4638 if (!pci_bus_trylock(dev->subordinate)) {
4639 pci_dev_unlock(dev);
4640 goto unlock;
4641 }
4642 }
4643 }
4644 return 1;
4645
4646unlock:
4647 list_for_each_entry_continue_reverse(dev,
4648 &slot->bus->devices, bus_list) {
4649 if (!dev->slot || dev->slot != slot)
4650 continue;
4651 if (dev->subordinate)
4652 pci_bus_unlock(dev->subordinate);
4653 pci_dev_unlock(dev);
4654 }
4655 return 0;
4656}
4657
4658/* Save and disable devices from the top of the tree down */
4659static void pci_bus_save_and_disable(struct pci_bus *bus)
4660{
4661 struct pci_dev *dev;
4662
4663 list_for_each_entry(dev, &bus->devices, bus_list) {
4664 pci_dev_lock(dev);
4665 pci_dev_save_and_disable(dev);
4666 pci_dev_unlock(dev);
4667 if (dev->subordinate)
4668 pci_bus_save_and_disable(dev->subordinate);
4669 }
4670}
4671
4672/*
4673 * Restore devices from top of the tree down - parent bridges need to be
4674 * restored before we can get to subordinate devices.
4675 */
4676static void pci_bus_restore(struct pci_bus *bus)
4677{
4678 struct pci_dev *dev;
4679
4680 list_for_each_entry(dev, &bus->devices, bus_list) {
4681 pci_dev_lock(dev);
4682 pci_dev_restore(dev);
4683 pci_dev_unlock(dev);
4684 if (dev->subordinate)
4685 pci_bus_restore(dev->subordinate);
4686 }
4687}
4688
4689/* Save and disable devices from the top of the tree down */
4690static void pci_slot_save_and_disable(struct pci_slot *slot)
4691{
4692 struct pci_dev *dev;
4693
4694 list_for_each_entry(dev, &slot->bus->devices, bus_list) {
4695 if (!dev->slot || dev->slot != slot)
4696 continue;
4697 pci_dev_save_and_disable(dev);
4698 if (dev->subordinate)
4699 pci_bus_save_and_disable(dev->subordinate);
4700 }
4701}
4702
4703/*
4704 * Restore devices from top of the tree down - parent bridges need to be
4705 * restored before we can get to subordinate devices.
4706 */
4707static void pci_slot_restore(struct pci_slot *slot)
4708{
4709 struct pci_dev *dev;
4710
4711 list_for_each_entry(dev, &slot->bus->devices, bus_list) {
4712 if (!dev->slot || dev->slot != slot)
4713 continue;
4714 pci_dev_lock(dev);
4715 pci_dev_restore(dev);
4716 pci_dev_unlock(dev);
4717 if (dev->subordinate)
4718 pci_bus_restore(dev->subordinate);
4719 }
4720}
4721
4722static int pci_slot_reset(struct pci_slot *slot, int probe)
4723{
4724 int rc;
4725
4726 if (!slot || !pci_slot_resetable(slot))
4727 return -ENOTTY;
4728
4729 if (!probe)
4730 pci_slot_lock(slot);
4731
4732 might_sleep();
4733
4734 rc = pci_reset_hotplug_slot(slot->hotplug, probe);
4735
4736 if (!probe)
4737 pci_slot_unlock(slot);
4738
4739 return rc;
4740}
4741
4742/**
4743 * pci_probe_reset_slot - probe whether a PCI slot can be reset
4744 * @slot: PCI slot to probe
4745 *
4746 * Return 0 if slot can be reset, negative if a slot reset is not supported.
4747 */
4748int pci_probe_reset_slot(struct pci_slot *slot)
4749{
4750 return pci_slot_reset(slot, 1);
4751}
4752EXPORT_SYMBOL_GPL(pci_probe_reset_slot);
4753
4754/**
4755 * pci_reset_slot - reset a PCI slot
4756 * @slot: PCI slot to reset
4757 *
4758 * A PCI bus may host multiple slots, each slot may support a reset mechanism
4759 * independent of other slots. For instance, some slots may support slot power
4760 * control. In the case of a 1:1 bus to slot architecture, this function may
4761 * wrap the bus reset to avoid spurious slot related events such as hotplug.
4762 * Generally a slot reset should be attempted before a bus reset. All of the
4763 * function of the slot and any subordinate buses behind the slot are reset
4764 * through this function. PCI config space of all devices in the slot and
4765 * behind the slot is saved before and restored after reset.
4766 *
4767 * Return 0 on success, non-zero on error.
4768 */
4769int pci_reset_slot(struct pci_slot *slot)
4770{
4771 int rc;
4772
4773 rc = pci_slot_reset(slot, 1);
4774 if (rc)
4775 return rc;
4776
4777 pci_slot_save_and_disable(slot);
4778
4779 rc = pci_slot_reset(slot, 0);
4780
4781 pci_slot_restore(slot);
4782
4783 return rc;
4784}
4785EXPORT_SYMBOL_GPL(pci_reset_slot);
4786
4787/**
4788 * pci_try_reset_slot - Try to reset a PCI slot
4789 * @slot: PCI slot to reset
4790 *
4791 * Same as above except return -EAGAIN if the slot cannot be locked
4792 */
4793int pci_try_reset_slot(struct pci_slot *slot)
4794{
4795 int rc;
4796
4797 rc = pci_slot_reset(slot, 1);
4798 if (rc)
4799 return rc;
4800
4801 pci_slot_save_and_disable(slot);
4802
4803 if (pci_slot_trylock(slot)) {
4804 might_sleep();
4805 rc = pci_reset_hotplug_slot(slot->hotplug, 0);
4806 pci_slot_unlock(slot);
4807 } else
4808 rc = -EAGAIN;
4809
4810 pci_slot_restore(slot);
4811
4812 return rc;
4813}
4814EXPORT_SYMBOL_GPL(pci_try_reset_slot);
4815
4816static int pci_bus_reset(struct pci_bus *bus, int probe)
4817{
4818 if (!bus->self || !pci_bus_resetable(bus))
4819 return -ENOTTY;
4820
4821 if (probe)
4822 return 0;
4823
4824 pci_bus_lock(bus);
4825
4826 might_sleep();
4827
4828 pci_reset_bridge_secondary_bus(bus->self);
4829
4830 pci_bus_unlock(bus);
4831
4832 return 0;
4833}
4834
4835/**
4836 * pci_probe_reset_bus - probe whether a PCI bus can be reset
4837 * @bus: PCI bus to probe
4838 *
4839 * Return 0 if bus can be reset, negative if a bus reset is not supported.
4840 */
4841int pci_probe_reset_bus(struct pci_bus *bus)
4842{
4843 return pci_bus_reset(bus, 1);
4844}
4845EXPORT_SYMBOL_GPL(pci_probe_reset_bus);
4846
4847/**
4848 * pci_reset_bus - reset a PCI bus
4849 * @bus: top level PCI bus to reset
4850 *
4851 * Do a bus reset on the given bus and any subordinate buses, saving
4852 * and restoring state of all devices.
4853 *
4854 * Return 0 on success, non-zero on error.
4855 */
4856int pci_reset_bus(struct pci_bus *bus)
4857{
4858 int rc;
4859
4860 rc = pci_bus_reset(bus, 1);
4861 if (rc)
4862 return rc;
4863
4864 pci_bus_save_and_disable(bus);
4865
4866 rc = pci_bus_reset(bus, 0);
4867
4868 pci_bus_restore(bus);
4869
4870 return rc;
4871}
4872EXPORT_SYMBOL_GPL(pci_reset_bus);
4873
4874/**
4875 * pci_try_reset_bus - Try to reset a PCI bus
4876 * @bus: top level PCI bus to reset
4877 *
4878 * Same as above except return -EAGAIN if the bus cannot be locked
4879 */
4880int pci_try_reset_bus(struct pci_bus *bus)
4881{
4882 int rc;
4883
4884 rc = pci_bus_reset(bus, 1);
4885 if (rc)
4886 return rc;
4887
4888 pci_bus_save_and_disable(bus);
4889
4890 if (pci_bus_trylock(bus)) {
4891 might_sleep();
4892 pci_reset_bridge_secondary_bus(bus->self);
4893 pci_bus_unlock(bus);
4894 } else
4895 rc = -EAGAIN;
4896
4897 pci_bus_restore(bus);
4898
4899 return rc;
4900}
4901EXPORT_SYMBOL_GPL(pci_try_reset_bus);
4902
4903/**
4904 * pcix_get_max_mmrbc - get PCI-X maximum designed memory read byte count
4905 * @dev: PCI device to query
4906 *
4907 * Returns mmrbc: maximum designed memory read count in bytes
4908 * or appropriate error value.
4909 */
4910int pcix_get_max_mmrbc(struct pci_dev *dev)
4911{
4912 int cap;
4913 u32 stat;
4914
4915 cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
4916 if (!cap)
4917 return -EINVAL;
4918
4919 if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat))
4920 return -EINVAL;
4921
4922 return 512 << ((stat & PCI_X_STATUS_MAX_READ) >> 21);
4923}
4924EXPORT_SYMBOL(pcix_get_max_mmrbc);
4925
4926/**
4927 * pcix_get_mmrbc - get PCI-X maximum memory read byte count
4928 * @dev: PCI device to query
4929 *
4930 * Returns mmrbc: maximum memory read count in bytes
4931 * or appropriate error value.
4932 */
4933int pcix_get_mmrbc(struct pci_dev *dev)
4934{
4935 int cap;
4936 u16 cmd;
4937
4938 cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
4939 if (!cap)
4940 return -EINVAL;
4941
4942 if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd))
4943 return -EINVAL;
4944
4945 return 512 << ((cmd & PCI_X_CMD_MAX_READ) >> 2);
4946}
4947EXPORT_SYMBOL(pcix_get_mmrbc);
4948
4949/**
4950 * pcix_set_mmrbc - set PCI-X maximum memory read byte count
4951 * @dev: PCI device to query
4952 * @mmrbc: maximum memory read count in bytes
4953 * valid values are 512, 1024, 2048, 4096
4954 *
4955 * If possible sets maximum memory read byte count, some bridges have erratas
4956 * that prevent this.
4957 */
4958int pcix_set_mmrbc(struct pci_dev *dev, int mmrbc)
4959{
4960 int cap;
4961 u32 stat, v, o;
4962 u16 cmd;
4963
4964 if (mmrbc < 512 || mmrbc > 4096 || !is_power_of_2(mmrbc))
4965 return -EINVAL;
4966
4967 v = ffs(mmrbc) - 10;
4968
4969 cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
4970 if (!cap)
4971 return -EINVAL;
4972
4973 if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat))
4974 return -EINVAL;
4975
4976 if (v > (stat & PCI_X_STATUS_MAX_READ) >> 21)
4977 return -E2BIG;
4978
4979 if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd))
4980 return -EINVAL;
4981
4982 o = (cmd & PCI_X_CMD_MAX_READ) >> 2;
4983 if (o != v) {
4984 if (v > o && (dev->bus->bus_flags & PCI_BUS_FLAGS_NO_MMRBC))
4985 return -EIO;
4986
4987 cmd &= ~PCI_X_CMD_MAX_READ;
4988 cmd |= v << 2;
4989 if (pci_write_config_word(dev, cap + PCI_X_CMD, cmd))
4990 return -EIO;
4991 }
4992 return 0;
4993}
4994EXPORT_SYMBOL(pcix_set_mmrbc);
4995
4996/**
4997 * pcie_get_readrq - get PCI Express read request size
4998 * @dev: PCI device to query
4999 *
5000 * Returns maximum memory read request in bytes
5001 * or appropriate error value.
5002 */
5003int pcie_get_readrq(struct pci_dev *dev)
5004{
5005 u16 ctl;
5006
5007 pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl);
5008
5009 return 128 << ((ctl & PCI_EXP_DEVCTL_READRQ) >> 12);
5010}
5011EXPORT_SYMBOL(pcie_get_readrq);
5012
5013/**
5014 * pcie_set_readrq - set PCI Express maximum memory read request
5015 * @dev: PCI device to query
5016 * @rq: maximum memory read count in bytes
5017 * valid values are 128, 256, 512, 1024, 2048, 4096
5018 *
5019 * If possible sets maximum memory read request in bytes
5020 */
5021int pcie_set_readrq(struct pci_dev *dev, int rq)
5022{
5023 u16 v;
5024
5025 if (rq < 128 || rq > 4096 || !is_power_of_2(rq))
5026 return -EINVAL;
5027
5028 /*
5029 * If using the "performance" PCIe config, we clamp the
5030 * read rq size to the max packet size to prevent the
5031 * host bridge generating requests larger than we can
5032 * cope with
5033 */
5034 if (pcie_bus_config == PCIE_BUS_PERFORMANCE) {
5035 int mps = pcie_get_mps(dev);
5036
5037 if (mps < rq)
5038 rq = mps;
5039 }
5040
5041 v = (ffs(rq) - 8) << 12;
5042
5043 return pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
5044 PCI_EXP_DEVCTL_READRQ, v);
5045}
5046EXPORT_SYMBOL(pcie_set_readrq);
5047
5048/**
5049 * pcie_get_mps - get PCI Express maximum payload size
5050 * @dev: PCI device to query
5051 *
5052 * Returns maximum payload size in bytes
5053 */
5054int pcie_get_mps(struct pci_dev *dev)
5055{
5056 u16 ctl;
5057
5058 pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl);
5059
5060 return 128 << ((ctl & PCI_EXP_DEVCTL_PAYLOAD) >> 5);
5061}
5062EXPORT_SYMBOL(pcie_get_mps);
5063
5064/**
5065 * pcie_set_mps - set PCI Express maximum payload size
5066 * @dev: PCI device to query
5067 * @mps: maximum payload size in bytes
5068 * valid values are 128, 256, 512, 1024, 2048, 4096
5069 *
5070 * If possible sets maximum payload size
5071 */
5072int pcie_set_mps(struct pci_dev *dev, int mps)
5073{
5074 u16 v;
5075
5076 if (mps < 128 || mps > 4096 || !is_power_of_2(mps))
5077 return -EINVAL;
5078
5079 v = ffs(mps) - 8;
5080 if (v > dev->pcie_mpss)
5081 return -EINVAL;
5082 v <<= 5;
5083
5084 return pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
5085 PCI_EXP_DEVCTL_PAYLOAD, v);
5086}
5087EXPORT_SYMBOL(pcie_set_mps);
5088
5089/**
5090 * pcie_get_minimum_link - determine minimum link settings of a PCI device
5091 * @dev: PCI device to query
5092 * @speed: storage for minimum speed
5093 * @width: storage for minimum width
5094 *
5095 * This function will walk up the PCI device chain and determine the minimum
5096 * link width and speed of the device.
5097 */
5098int pcie_get_minimum_link(struct pci_dev *dev, enum pci_bus_speed *speed,
5099 enum pcie_link_width *width)
5100{
5101 int ret;
5102
5103 *speed = PCI_SPEED_UNKNOWN;
5104 *width = PCIE_LNK_WIDTH_UNKNOWN;
5105
5106 while (dev) {
5107 u16 lnksta;
5108 enum pci_bus_speed next_speed;
5109 enum pcie_link_width next_width;
5110
5111 ret = pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta);
5112 if (ret)
5113 return ret;
5114
5115 next_speed = pcie_link_speed[lnksta & PCI_EXP_LNKSTA_CLS];
5116 next_width = (lnksta & PCI_EXP_LNKSTA_NLW) >>
5117 PCI_EXP_LNKSTA_NLW_SHIFT;
5118
5119 if (next_speed < *speed)
5120 *speed = next_speed;
5121
5122 if (next_width < *width)
5123 *width = next_width;
5124
5125 dev = dev->bus->self;
5126 }
5127
5128 return 0;
5129}
5130EXPORT_SYMBOL(pcie_get_minimum_link);
5131
5132/**
5133 * pcie_bandwidth_available - determine minimum link settings of a PCIe
5134 * device and its bandwidth limitation
5135 * @dev: PCI device to query
5136 * @limiting_dev: storage for device causing the bandwidth limitation
5137 * @speed: storage for speed of limiting device
5138 * @width: storage for width of limiting device
5139 *
5140 * Walk up the PCI device chain and find the point where the minimum
5141 * bandwidth is available. Return the bandwidth available there and (if
5142 * limiting_dev, speed, and width pointers are supplied) information about
5143 * that point. The bandwidth returned is in Mb/s, i.e., megabits/second of
5144 * raw bandwidth.
5145 */
5146u32 pcie_bandwidth_available(struct pci_dev *dev, struct pci_dev **limiting_dev,
5147 enum pci_bus_speed *speed,
5148 enum pcie_link_width *width)
5149{
5150 u16 lnksta;
5151 enum pci_bus_speed next_speed;
5152 enum pcie_link_width next_width;
5153 u32 bw, next_bw;
5154
5155 if (speed)
5156 *speed = PCI_SPEED_UNKNOWN;
5157 if (width)
5158 *width = PCIE_LNK_WIDTH_UNKNOWN;
5159
5160 bw = 0;
5161
5162 while (dev) {
5163 pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta);
5164
5165 next_speed = pcie_link_speed[lnksta & PCI_EXP_LNKSTA_CLS];
5166 next_width = (lnksta & PCI_EXP_LNKSTA_NLW) >>
5167 PCI_EXP_LNKSTA_NLW_SHIFT;
5168
5169 next_bw = next_width * PCIE_SPEED2MBS_ENC(next_speed);
5170
5171 /* Check if current device limits the total bandwidth */
5172 if (!bw || next_bw <= bw) {
5173 bw = next_bw;
5174
5175 if (limiting_dev)
5176 *limiting_dev = dev;
5177 if (speed)
5178 *speed = next_speed;
5179 if (width)
5180 *width = next_width;
5181 }
5182
5183 dev = pci_upstream_bridge(dev);
5184 }
5185
5186 return bw;
5187}
5188EXPORT_SYMBOL(pcie_bandwidth_available);
5189
5190/**
5191 * pcie_get_speed_cap - query for the PCI device's link speed capability
5192 * @dev: PCI device to query
5193 *
5194 * Query the PCI device speed capability. Return the maximum link speed
5195 * supported by the device.
5196 */
5197enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev)
5198{
5199 u32 lnkcap2, lnkcap;
5200
5201 /*
5202 * PCIe r4.0 sec 7.5.3.18 recommends using the Supported Link
5203 * Speeds Vector in Link Capabilities 2 when supported, falling
5204 * back to Max Link Speed in Link Capabilities otherwise.
5205 */
5206 pcie_capability_read_dword(dev, PCI_EXP_LNKCAP2, &lnkcap2);
5207 if (lnkcap2) { /* PCIe r3.0-compliant */
5208 if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_16_0GB)
5209 return PCIE_SPEED_16_0GT;
5210 else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_8_0GB)
5211 return PCIE_SPEED_8_0GT;
5212 else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_5_0GB)
5213 return PCIE_SPEED_5_0GT;
5214 else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_2_5GB)
5215 return PCIE_SPEED_2_5GT;
5216 return PCI_SPEED_UNKNOWN;
5217 }
5218
5219 pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap);
5220 if (lnkcap) {
5221 if (lnkcap & PCI_EXP_LNKCAP_SLS_16_0GB)
5222 return PCIE_SPEED_16_0GT;
5223 else if (lnkcap & PCI_EXP_LNKCAP_SLS_8_0GB)
5224 return PCIE_SPEED_8_0GT;
5225 else if (lnkcap & PCI_EXP_LNKCAP_SLS_5_0GB)
5226 return PCIE_SPEED_5_0GT;
5227 else if (lnkcap & PCI_EXP_LNKCAP_SLS_2_5GB)
5228 return PCIE_SPEED_2_5GT;
5229 }
5230
5231 return PCI_SPEED_UNKNOWN;
5232}
5233
5234/**
5235 * pcie_get_width_cap - query for the PCI device's link width capability
5236 * @dev: PCI device to query
5237 *
5238 * Query the PCI device width capability. Return the maximum link width
5239 * supported by the device.
5240 */
5241enum pcie_link_width pcie_get_width_cap(struct pci_dev *dev)
5242{
5243 u32 lnkcap;
5244
5245 pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap);
5246 if (lnkcap)
5247 return (lnkcap & PCI_EXP_LNKCAP_MLW) >> 4;
5248
5249 return PCIE_LNK_WIDTH_UNKNOWN;
5250}
5251
5252/**
5253 * pcie_bandwidth_capable - calculate a PCI device's link bandwidth capability
5254 * @dev: PCI device
5255 * @speed: storage for link speed
5256 * @width: storage for link width
5257 *
5258 * Calculate a PCI device's link bandwidth by querying for its link speed
5259 * and width, multiplying them, and applying encoding overhead. The result
5260 * is in Mb/s, i.e., megabits/second of raw bandwidth.
5261 */
5262u32 pcie_bandwidth_capable(struct pci_dev *dev, enum pci_bus_speed *speed,
5263 enum pcie_link_width *width)
5264{
5265 *speed = pcie_get_speed_cap(dev);
5266 *width = pcie_get_width_cap(dev);
5267
5268 if (*speed == PCI_SPEED_UNKNOWN || *width == PCIE_LNK_WIDTH_UNKNOWN)
5269 return 0;
5270
5271 return *width * PCIE_SPEED2MBS_ENC(*speed);
5272}
5273
5274/**
5275 * pcie_print_link_status - Report the PCI device's link speed and width
5276 * @dev: PCI device to query
5277 *
5278 * Report the available bandwidth at the device. If this is less than the
5279 * device is capable of, report the device's maximum possible bandwidth and
5280 * the upstream link that limits its performance to less than that.
5281 */
5282void pcie_print_link_status(struct pci_dev *dev)
5283{
5284 enum pcie_link_width width, width_cap;
5285 enum pci_bus_speed speed, speed_cap;
5286 struct pci_dev *limiting_dev = NULL;
5287 u32 bw_avail, bw_cap;
5288
5289 bw_cap = pcie_bandwidth_capable(dev, &speed_cap, &width_cap);
5290 bw_avail = pcie_bandwidth_available(dev, &limiting_dev, &speed, &width);
5291
5292 if (bw_avail >= bw_cap)
5293 pci_info(dev, "%u.%03u Gb/s available PCIe bandwidth (%s x%d link)\n",
5294 bw_cap / 1000, bw_cap % 1000,
5295 PCIE_SPEED2STR(speed_cap), width_cap);
5296 else
5297 pci_info(dev, "%u.%03u Gb/s available PCIe bandwidth, limited by %s x%d link at %s (capable of %u.%03u Gb/s with %s x%d link)\n",
5298 bw_avail / 1000, bw_avail % 1000,
5299 PCIE_SPEED2STR(speed), width,
5300 limiting_dev ? pci_name(limiting_dev) : "<unknown>",
5301 bw_cap / 1000, bw_cap % 1000,
5302 PCIE_SPEED2STR(speed_cap), width_cap);
5303}
5304EXPORT_SYMBOL(pcie_print_link_status);
5305
5306/**
5307 * pci_select_bars - Make BAR mask from the type of resource
5308 * @dev: the PCI device for which BAR mask is made
5309 * @flags: resource type mask to be selected
5310 *
5311 * This helper routine makes bar mask from the type of resource.
5312 */
5313int pci_select_bars(struct pci_dev *dev, unsigned long flags)
5314{
5315 int i, bars = 0;
5316 for (i = 0; i < PCI_NUM_RESOURCES; i++)
5317 if (pci_resource_flags(dev, i) & flags)
5318 bars |= (1 << i);
5319 return bars;
5320}
5321EXPORT_SYMBOL(pci_select_bars);
5322
5323/* Some architectures require additional programming to enable VGA */
5324static arch_set_vga_state_t arch_set_vga_state;
5325
5326void __init pci_register_set_vga_state(arch_set_vga_state_t func)
5327{
5328 arch_set_vga_state = func; /* NULL disables */
5329}
5330
5331static int pci_set_vga_state_arch(struct pci_dev *dev, bool decode,
5332 unsigned int command_bits, u32 flags)
5333{
5334 if (arch_set_vga_state)
5335 return arch_set_vga_state(dev, decode, command_bits,
5336 flags);
5337 return 0;
5338}
5339
5340/**
5341 * pci_set_vga_state - set VGA decode state on device and parents if requested
5342 * @dev: the PCI device
5343 * @decode: true = enable decoding, false = disable decoding
5344 * @command_bits: PCI_COMMAND_IO and/or PCI_COMMAND_MEMORY
5345 * @flags: traverse ancestors and change bridges
5346 * CHANGE_BRIDGE_ONLY / CHANGE_BRIDGE
5347 */
5348int pci_set_vga_state(struct pci_dev *dev, bool decode,
5349 unsigned int command_bits, u32 flags)
5350{
5351 struct pci_bus *bus;
5352 struct pci_dev *bridge;
5353 u16 cmd;
5354 int rc;
5355
5356 WARN_ON((flags & PCI_VGA_STATE_CHANGE_DECODES) && (command_bits & ~(PCI_COMMAND_IO|PCI_COMMAND_MEMORY)));
5357
5358 /* ARCH specific VGA enables */
5359 rc = pci_set_vga_state_arch(dev, decode, command_bits, flags);
5360 if (rc)
5361 return rc;
5362
5363 if (flags & PCI_VGA_STATE_CHANGE_DECODES) {
5364 pci_read_config_word(dev, PCI_COMMAND, &cmd);
5365 if (decode == true)
5366 cmd |= command_bits;
5367 else
5368 cmd &= ~command_bits;
5369 pci_write_config_word(dev, PCI_COMMAND, cmd);
5370 }
5371
5372 if (!(flags & PCI_VGA_STATE_CHANGE_BRIDGE))
5373 return 0;
5374
5375 bus = dev->bus;
5376 while (bus) {
5377 bridge = bus->self;
5378 if (bridge) {
5379 pci_read_config_word(bridge, PCI_BRIDGE_CONTROL,
5380 &cmd);
5381 if (decode == true)
5382 cmd |= PCI_BRIDGE_CTL_VGA;
5383 else
5384 cmd &= ~PCI_BRIDGE_CTL_VGA;
5385 pci_write_config_word(bridge, PCI_BRIDGE_CONTROL,
5386 cmd);
5387 }
5388 bus = bus->parent;
5389 }
5390 return 0;
5391}
5392
5393/**
5394 * pci_add_dma_alias - Add a DMA devfn alias for a device
5395 * @dev: the PCI device for which alias is added
5396 * @devfn: alias slot and function
5397 *
5398 * This helper encodes 8-bit devfn as bit number in dma_alias_mask.
5399 * It should be called early, preferably as PCI fixup header quirk.
5400 */
5401void pci_add_dma_alias(struct pci_dev *dev, u8 devfn)
5402{
5403 if (!dev->dma_alias_mask)
5404 dev->dma_alias_mask = kcalloc(BITS_TO_LONGS(U8_MAX),
5405 sizeof(long), GFP_KERNEL);
5406 if (!dev->dma_alias_mask) {
5407 pci_warn(dev, "Unable to allocate DMA alias mask\n");
5408 return;
5409 }
5410
5411 set_bit(devfn, dev->dma_alias_mask);
5412 pci_info(dev, "Enabling fixed DMA alias to %02x.%d\n",
5413 PCI_SLOT(devfn), PCI_FUNC(devfn));
5414}
5415
5416bool pci_devs_are_dma_aliases(struct pci_dev *dev1, struct pci_dev *dev2)
5417{
5418 return (dev1->dma_alias_mask &&
5419 test_bit(dev2->devfn, dev1->dma_alias_mask)) ||
5420 (dev2->dma_alias_mask &&
5421 test_bit(dev1->devfn, dev2->dma_alias_mask));
5422}
5423
5424bool pci_device_is_present(struct pci_dev *pdev)
5425{
5426 u32 v;
5427
5428 if (pci_dev_is_disconnected(pdev))
5429 return false;
5430 return pci_bus_read_dev_vendor_id(pdev->bus, pdev->devfn, &v, 0);
5431}
5432EXPORT_SYMBOL_GPL(pci_device_is_present);
5433
5434void pci_ignore_hotplug(struct pci_dev *dev)
5435{
5436 struct pci_dev *bridge = dev->bus->self;
5437
5438 dev->ignore_hotplug = 1;
5439 /* Propagate the "ignore hotplug" setting to the parent bridge. */
5440 if (bridge)
5441 bridge->ignore_hotplug = 1;
5442}
5443EXPORT_SYMBOL_GPL(pci_ignore_hotplug);
5444
5445resource_size_t __weak pcibios_default_alignment(void)
5446{
5447 return 0;
5448}
5449
5450#define RESOURCE_ALIGNMENT_PARAM_SIZE COMMAND_LINE_SIZE
5451static char resource_alignment_param[RESOURCE_ALIGNMENT_PARAM_SIZE] = {0};
5452static DEFINE_SPINLOCK(resource_alignment_lock);
5453
5454/**
5455 * pci_specified_resource_alignment - get resource alignment specified by user.
5456 * @dev: the PCI device to get
5457 * @resize: whether or not to change resources' size when reassigning alignment
5458 *
5459 * RETURNS: Resource alignment if it is specified.
5460 * Zero if it is not specified.
5461 */
5462static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev,
5463 bool *resize)
5464{
5465 int seg, bus, slot, func, align_order, count;
5466 unsigned short vendor, device, subsystem_vendor, subsystem_device;
5467 resource_size_t align = pcibios_default_alignment();
5468 char *p;
5469
5470 spin_lock(&resource_alignment_lock);
5471 p = resource_alignment_param;
5472 if (!*p && !align)
5473 goto out;
5474 if (pci_has_flag(PCI_PROBE_ONLY)) {
5475 align = 0;
5476 pr_info_once("PCI: Ignoring requested alignments (PCI_PROBE_ONLY)\n");
5477 goto out;
5478 }
5479
5480 while (*p) {
5481 count = 0;
5482 if (sscanf(p, "%d%n", &align_order, &count) == 1 &&
5483 p[count] == '@') {
5484 p += count + 1;
5485 } else {
5486 align_order = -1;
5487 }
5488 if (strncmp(p, "pci:", 4) == 0) {
5489 /* PCI vendor/device (subvendor/subdevice) ids are specified */
5490 p += 4;
5491 if (sscanf(p, "%hx:%hx:%hx:%hx%n",
5492 &vendor, &device, &subsystem_vendor, &subsystem_device, &count) != 4) {
5493 if (sscanf(p, "%hx:%hx%n", &vendor, &device, &count) != 2) {
5494 printk(KERN_ERR "PCI: Can't parse resource_alignment parameter: pci:%s\n",
5495 p);
5496 break;
5497 }
5498 subsystem_vendor = subsystem_device = 0;
5499 }
5500 p += count;
5501 if ((!vendor || (vendor == dev->vendor)) &&
5502 (!device || (device == dev->device)) &&
5503 (!subsystem_vendor || (subsystem_vendor == dev->subsystem_vendor)) &&
5504 (!subsystem_device || (subsystem_device == dev->subsystem_device))) {
5505 *resize = true;
5506 if (align_order == -1)
5507 align = PAGE_SIZE;
5508 else
5509 align = 1 << align_order;
5510 /* Found */
5511 break;
5512 }
5513 }
5514 else {
5515 if (sscanf(p, "%x:%x:%x.%x%n",
5516 &seg, &bus, &slot, &func, &count) != 4) {
5517 seg = 0;
5518 if (sscanf(p, "%x:%x.%x%n",
5519 &bus, &slot, &func, &count) != 3) {
5520 /* Invalid format */
5521 printk(KERN_ERR "PCI: Can't parse resource_alignment parameter: %s\n",
5522 p);
5523 break;
5524 }
5525 }
5526 p += count;
5527 if (seg == pci_domain_nr(dev->bus) &&
5528 bus == dev->bus->number &&
5529 slot == PCI_SLOT(dev->devfn) &&
5530 func == PCI_FUNC(dev->devfn)) {
5531 *resize = true;
5532 if (align_order == -1)
5533 align = PAGE_SIZE;
5534 else
5535 align = 1 << align_order;
5536 /* Found */
5537 break;
5538 }
5539 }
5540 if (*p != ';' && *p != ',') {
5541 /* End of param or invalid format */
5542 break;
5543 }
5544 p++;
5545 }
5546out:
5547 spin_unlock(&resource_alignment_lock);
5548 return align;
5549}
5550
5551static void pci_request_resource_alignment(struct pci_dev *dev, int bar,
5552 resource_size_t align, bool resize)
5553{
5554 struct resource *r = &dev->resource[bar];
5555 resource_size_t size;
5556
5557 if (!(r->flags & IORESOURCE_MEM))
5558 return;
5559
5560 if (r->flags & IORESOURCE_PCI_FIXED) {
5561 pci_info(dev, "BAR%d %pR: ignoring requested alignment %#llx\n",
5562 bar, r, (unsigned long long)align);
5563 return;
5564 }
5565
5566 size = resource_size(r);
5567 if (size >= align)
5568 return;
5569
5570 /*
5571 * Increase the alignment of the resource. There are two ways we
5572 * can do this:
5573 *
5574 * 1) Increase the size of the resource. BARs are aligned on their
5575 * size, so when we reallocate space for this resource, we'll
5576 * allocate it with the larger alignment. This also prevents
5577 * assignment of any other BARs inside the alignment region, so
5578 * if we're requesting page alignment, this means no other BARs
5579 * will share the page.
5580 *
5581 * The disadvantage is that this makes the resource larger than
5582 * the hardware BAR, which may break drivers that compute things
5583 * based on the resource size, e.g., to find registers at a
5584 * fixed offset before the end of the BAR.
5585 *
5586 * 2) Retain the resource size, but use IORESOURCE_STARTALIGN and
5587 * set r->start to the desired alignment. By itself this
5588 * doesn't prevent other BARs being put inside the alignment
5589 * region, but if we realign *every* resource of every device in
5590 * the system, none of them will share an alignment region.
5591 *
5592 * When the user has requested alignment for only some devices via
5593 * the "pci=resource_alignment" argument, "resize" is true and we
5594 * use the first method. Otherwise we assume we're aligning all
5595 * devices and we use the second.
5596 */
5597
5598 pci_info(dev, "BAR%d %pR: requesting alignment to %#llx\n",
5599 bar, r, (unsigned long long)align);
5600
5601 if (resize) {
5602 r->start = 0;
5603 r->end = align - 1;
5604 } else {
5605 r->flags &= ~IORESOURCE_SIZEALIGN;
5606 r->flags |= IORESOURCE_STARTALIGN;
5607 r->start = align;
5608 r->end = r->start + size - 1;
5609 }
5610 r->flags |= IORESOURCE_UNSET;
5611}
5612
5613/*
5614 * This function disables memory decoding and releases memory resources
5615 * of the device specified by kernel's boot parameter 'pci=resource_alignment='.
5616 * It also rounds up size to specified alignment.
5617 * Later on, the kernel will assign page-aligned memory resource back
5618 * to the device.
5619 */
5620void pci_reassigndev_resource_alignment(struct pci_dev *dev)
5621{
5622 int i;
5623 struct resource *r;
5624 resource_size_t align;
5625 u16 command;
5626 bool resize = false;
5627
5628 /*
5629 * VF BARs are read-only zero according to SR-IOV spec r1.1, sec
5630 * 3.4.1.11. Their resources are allocated from the space
5631 * described by the VF BARx register in the PF's SR-IOV capability.
5632 * We can't influence their alignment here.
5633 */
5634 if (dev->is_virtfn)
5635 return;
5636
5637 /* check if specified PCI is target device to reassign */
5638 align = pci_specified_resource_alignment(dev, &resize);
5639 if (!align)
5640 return;
5641
5642 if (dev->hdr_type == PCI_HEADER_TYPE_NORMAL &&
5643 (dev->class >> 8) == PCI_CLASS_BRIDGE_HOST) {
5644 pci_warn(dev, "Can't reassign resources to host bridge\n");
5645 return;
5646 }
5647
5648 pci_read_config_word(dev, PCI_COMMAND, &command);
5649 command &= ~PCI_COMMAND_MEMORY;
5650 pci_write_config_word(dev, PCI_COMMAND, command);
5651
5652 for (i = 0; i <= PCI_ROM_RESOURCE; i++)
5653 pci_request_resource_alignment(dev, i, align, resize);
5654
5655 /*
5656 * Need to disable bridge's resource window,
5657 * to enable the kernel to reassign new resource
5658 * window later on.
5659 */
5660 if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE &&
5661 (dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
5662 for (i = PCI_BRIDGE_RESOURCES; i < PCI_NUM_RESOURCES; i++) {
5663 r = &dev->resource[i];
5664 if (!(r->flags & IORESOURCE_MEM))
5665 continue;
5666 r->flags |= IORESOURCE_UNSET;
5667 r->end = resource_size(r) - 1;
5668 r->start = 0;
5669 }
5670 pci_disable_bridge_window(dev);
5671 }
5672}
5673
5674static ssize_t pci_set_resource_alignment_param(const char *buf, size_t count)
5675{
5676 if (count > RESOURCE_ALIGNMENT_PARAM_SIZE - 1)
5677 count = RESOURCE_ALIGNMENT_PARAM_SIZE - 1;
5678 spin_lock(&resource_alignment_lock);
5679 strncpy(resource_alignment_param, buf, count);
5680 resource_alignment_param[count] = '\0';
5681 spin_unlock(&resource_alignment_lock);
5682 return count;
5683}
5684
5685static ssize_t pci_get_resource_alignment_param(char *buf, size_t size)
5686{
5687 size_t count;
5688 spin_lock(&resource_alignment_lock);
5689 count = snprintf(buf, size, "%s", resource_alignment_param);
5690 spin_unlock(&resource_alignment_lock);
5691 return count;
5692}
5693
5694static ssize_t pci_resource_alignment_show(struct bus_type *bus, char *buf)
5695{
5696 return pci_get_resource_alignment_param(buf, PAGE_SIZE);
5697}
5698
5699static ssize_t pci_resource_alignment_store(struct bus_type *bus,
5700 const char *buf, size_t count)
5701{
5702 return pci_set_resource_alignment_param(buf, count);
5703}
5704
5705static BUS_ATTR(resource_alignment, 0644, pci_resource_alignment_show,
5706 pci_resource_alignment_store);
5707
5708static int __init pci_resource_alignment_sysfs_init(void)
5709{
5710 return bus_create_file(&pci_bus_type,
5711 &bus_attr_resource_alignment);
5712}
5713late_initcall(pci_resource_alignment_sysfs_init);
5714
5715static void pci_no_domains(void)
5716{
5717#ifdef CONFIG_PCI_DOMAINS
5718 pci_domains_supported = 0;
5719#endif
5720}
5721
5722#ifdef CONFIG_PCI_DOMAINS
5723static atomic_t __domain_nr = ATOMIC_INIT(-1);
5724
5725int pci_get_new_domain_nr(void)
5726{
5727 return atomic_inc_return(&__domain_nr);
5728}
5729
5730#ifdef CONFIG_PCI_DOMAINS_GENERIC
5731static int of_pci_bus_find_domain_nr(struct device *parent)
5732{
5733 static int use_dt_domains = -1;
5734 int domain = -1;
5735
5736 if (parent)
5737 domain = of_get_pci_domain_nr(parent->of_node);
5738 /*
5739 * Check DT domain and use_dt_domains values.
5740 *
5741 * If DT domain property is valid (domain >= 0) and
5742 * use_dt_domains != 0, the DT assignment is valid since this means
5743 * we have not previously allocated a domain number by using
5744 * pci_get_new_domain_nr(); we should also update use_dt_domains to
5745 * 1, to indicate that we have just assigned a domain number from
5746 * DT.
5747 *
5748 * If DT domain property value is not valid (ie domain < 0), and we
5749 * have not previously assigned a domain number from DT
5750 * (use_dt_domains != 1) we should assign a domain number by
5751 * using the:
5752 *
5753 * pci_get_new_domain_nr()
5754 *
5755 * API and update the use_dt_domains value to keep track of method we
5756 * are using to assign domain numbers (use_dt_domains = 0).
5757 *
5758 * All other combinations imply we have a platform that is trying
5759 * to mix domain numbers obtained from DT and pci_get_new_domain_nr(),
5760 * which is a recipe for domain mishandling and it is prevented by
5761 * invalidating the domain value (domain = -1) and printing a
5762 * corresponding error.
5763 */
5764 if (domain >= 0 && use_dt_domains) {
5765 use_dt_domains = 1;
5766 } else if (domain < 0 && use_dt_domains != 1) {
5767 use_dt_domains = 0;
5768 domain = pci_get_new_domain_nr();
5769 } else {
5770 if (parent)
5771 pr_err("Node %pOF has ", parent->of_node);
5772 pr_err("Inconsistent \"linux,pci-domain\" property in DT\n");
5773 domain = -1;
5774 }
5775
5776 return domain;
5777}
5778
5779int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent)
5780{
5781 return acpi_disabled ? of_pci_bus_find_domain_nr(parent) :
5782 acpi_pci_bus_find_domain_nr(bus);
5783}
5784#endif
5785#endif
5786
5787/**
5788 * pci_ext_cfg_avail - can we access extended PCI config space?
5789 *
5790 * Returns 1 if we can access PCI extended config space (offsets
5791 * greater than 0xff). This is the default implementation. Architecture
5792 * implementations can override this.
5793 */
5794int __weak pci_ext_cfg_avail(void)
5795{
5796 return 1;
5797}
5798
5799void __weak pci_fixup_cardbus(struct pci_bus *bus)
5800{
5801}
5802EXPORT_SYMBOL(pci_fixup_cardbus);
5803
5804static int __init pci_setup(char *str)
5805{
5806 while (str) {
5807 char *k = strchr(str, ',');
5808 if (k)
5809 *k++ = 0;
5810 if (*str && (str = pcibios_setup(str)) && *str) {
5811 if (!strcmp(str, "nomsi")) {
5812 pci_no_msi();
5813 } else if (!strcmp(str, "noaer")) {
5814 pci_no_aer();
5815 } else if (!strncmp(str, "realloc=", 8)) {
5816 pci_realloc_get_opt(str + 8);
5817 } else if (!strncmp(str, "realloc", 7)) {
5818 pci_realloc_get_opt("on");
5819 } else if (!strcmp(str, "nodomains")) {
5820 pci_no_domains();
5821 } else if (!strncmp(str, "noari", 5)) {
5822 pcie_ari_disabled = true;
5823 } else if (!strncmp(str, "cbiosize=", 9)) {
5824 pci_cardbus_io_size = memparse(str + 9, &str);
5825 } else if (!strncmp(str, "cbmemsize=", 10)) {
5826 pci_cardbus_mem_size = memparse(str + 10, &str);
5827 } else if (!strncmp(str, "resource_alignment=", 19)) {
5828 pci_set_resource_alignment_param(str + 19,
5829 strlen(str + 19));
5830 } else if (!strncmp(str, "ecrc=", 5)) {
5831 pcie_ecrc_get_policy(str + 5);
5832 } else if (!strncmp(str, "hpiosize=", 9)) {
5833 pci_hotplug_io_size = memparse(str + 9, &str);
5834 } else if (!strncmp(str, "hpmemsize=", 10)) {
5835 pci_hotplug_mem_size = memparse(str + 10, &str);
5836 } else if (!strncmp(str, "hpbussize=", 10)) {
5837 pci_hotplug_bus_size =
5838 simple_strtoul(str + 10, &str, 0);
5839 if (pci_hotplug_bus_size > 0xff)
5840 pci_hotplug_bus_size = DEFAULT_HOTPLUG_BUS_SIZE;
5841 } else if (!strncmp(str, "pcie_bus_tune_off", 17)) {
5842 pcie_bus_config = PCIE_BUS_TUNE_OFF;
5843 } else if (!strncmp(str, "pcie_bus_safe", 13)) {
5844 pcie_bus_config = PCIE_BUS_SAFE;
5845 } else if (!strncmp(str, "pcie_bus_perf", 13)) {
5846 pcie_bus_config = PCIE_BUS_PERFORMANCE;
5847 } else if (!strncmp(str, "pcie_bus_peer2peer", 18)) {
5848 pcie_bus_config = PCIE_BUS_PEER2PEER;
5849 } else if (!strncmp(str, "pcie_scan_all", 13)) {
5850 pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS);
5851 } else {
5852 printk(KERN_ERR "PCI: Unknown option `%s'\n",
5853 str);
5854 }
5855 }
5856 str = k;
5857 }
5858 return 0;
5859}
5860early_param("pci", pci_setup);