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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/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);
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/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 <linux/pci-ats.h>
33#include <asm/setup.h>
34#include <asm/dma.h>
35#include <linux/aer.h>
36#include "pci.h"
37
38DEFINE_MUTEX(pci_slot_mutex);
39
40const char *pci_power_names[] = {
41 "error", "D0", "D1", "D2", "D3hot", "D3cold", "unknown",
42};
43EXPORT_SYMBOL_GPL(pci_power_names);
44
45int isa_dma_bridge_buggy;
46EXPORT_SYMBOL(isa_dma_bridge_buggy);
47
48int pci_pci_problems;
49EXPORT_SYMBOL(pci_pci_problems);
50
51unsigned int pci_pm_d3_delay;
52
53static void pci_pme_list_scan(struct work_struct *work);
54
55static LIST_HEAD(pci_pme_list);
56static DEFINE_MUTEX(pci_pme_list_mutex);
57static DECLARE_DELAYED_WORK(pci_pme_work, pci_pme_list_scan);
58
59struct pci_pme_device {
60 struct list_head list;
61 struct pci_dev *dev;
62};
63
64#define PME_TIMEOUT 1000 /* How long between PME checks */
65
66static void pci_dev_d3_sleep(struct pci_dev *dev)
67{
68 unsigned int delay = dev->d3_delay;
69
70 if (delay < pci_pm_d3_delay)
71 delay = pci_pm_d3_delay;
72
73 if (delay)
74 msleep(delay);
75}
76
77#ifdef CONFIG_PCI_DOMAINS
78int pci_domains_supported = 1;
79#endif
80
81#define DEFAULT_CARDBUS_IO_SIZE (256)
82#define DEFAULT_CARDBUS_MEM_SIZE (64*1024*1024)
83/* pci=cbmemsize=nnM,cbiosize=nn can override this */
84unsigned long pci_cardbus_io_size = DEFAULT_CARDBUS_IO_SIZE;
85unsigned long pci_cardbus_mem_size = DEFAULT_CARDBUS_MEM_SIZE;
86
87#define DEFAULT_HOTPLUG_IO_SIZE (256)
88#define DEFAULT_HOTPLUG_MEM_SIZE (2*1024*1024)
89/* pci=hpmemsize=nnM,hpiosize=nn can override this */
90unsigned long pci_hotplug_io_size = DEFAULT_HOTPLUG_IO_SIZE;
91unsigned long pci_hotplug_mem_size = DEFAULT_HOTPLUG_MEM_SIZE;
92
93#define DEFAULT_HOTPLUG_BUS_SIZE 1
94unsigned long pci_hotplug_bus_size = DEFAULT_HOTPLUG_BUS_SIZE;
95
96enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_DEFAULT;
97
98/*
99 * The default CLS is used if arch didn't set CLS explicitly and not
100 * all pci devices agree on the same value. Arch can override either
101 * the dfl or actual value as it sees fit. Don't forget this is
102 * measured in 32-bit words, not bytes.
103 */
104u8 pci_dfl_cache_line_size = L1_CACHE_BYTES >> 2;
105u8 pci_cache_line_size;
106
107/*
108 * If we set up a device for bus mastering, we need to check the latency
109 * timer as certain BIOSes forget to set it properly.
110 */
111unsigned int pcibios_max_latency = 255;
112
113/* If set, the PCIe ARI capability will not be used. */
114static bool pcie_ari_disabled;
115
116/* If set, the PCIe ATS capability will not be used. */
117static bool pcie_ats_disabled;
118
119/* If set, the PCI config space of each device is printed during boot. */
120bool pci_early_dump;
121
122bool pci_ats_disabled(void)
123{
124 return pcie_ats_disabled;
125}
126
127/* Disable bridge_d3 for all PCIe ports */
128static bool pci_bridge_d3_disable;
129/* Force bridge_d3 for all PCIe ports */
130static bool pci_bridge_d3_force;
131
132static int __init pcie_port_pm_setup(char *str)
133{
134 if (!strcmp(str, "off"))
135 pci_bridge_d3_disable = true;
136 else if (!strcmp(str, "force"))
137 pci_bridge_d3_force = true;
138 return 1;
139}
140__setup("pcie_port_pm=", pcie_port_pm_setup);
141
142/* Time to wait after a reset for device to become responsive */
143#define PCIE_RESET_READY_POLL_MS 60000
144
145/**
146 * pci_bus_max_busnr - returns maximum PCI bus number of given bus' children
147 * @bus: pointer to PCI bus structure to search
148 *
149 * Given a PCI bus, returns the highest PCI bus number present in the set
150 * including the given PCI bus and its list of child PCI buses.
151 */
152unsigned char pci_bus_max_busnr(struct pci_bus *bus)
153{
154 struct pci_bus *tmp;
155 unsigned char max, n;
156
157 max = bus->busn_res.end;
158 list_for_each_entry(tmp, &bus->children, node) {
159 n = pci_bus_max_busnr(tmp);
160 if (n > max)
161 max = n;
162 }
163 return max;
164}
165EXPORT_SYMBOL_GPL(pci_bus_max_busnr);
166
167#ifdef CONFIG_HAS_IOMEM
168void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar)
169{
170 struct resource *res = &pdev->resource[bar];
171
172 /*
173 * Make sure the BAR is actually a memory resource, not an IO resource
174 */
175 if (res->flags & IORESOURCE_UNSET || !(res->flags & IORESOURCE_MEM)) {
176 pci_warn(pdev, "can't ioremap BAR %d: %pR\n", bar, res);
177 return NULL;
178 }
179 return ioremap_nocache(res->start, resource_size(res));
180}
181EXPORT_SYMBOL_GPL(pci_ioremap_bar);
182
183void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar)
184{
185 /*
186 * Make sure the BAR is actually a memory resource, not an IO resource
187 */
188 if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM)) {
189 WARN_ON(1);
190 return NULL;
191 }
192 return ioremap_wc(pci_resource_start(pdev, bar),
193 pci_resource_len(pdev, bar));
194}
195EXPORT_SYMBOL_GPL(pci_ioremap_wc_bar);
196#endif
197
198/**
199 * pci_dev_str_match_path - test if a path string matches a device
200 * @dev: the PCI device to test
201 * @path: string to match the device against
202 * @endptr: pointer to the string after the match
203 *
204 * Test if a string (typically from a kernel parameter) formatted as a
205 * path of device/function addresses matches a PCI device. The string must
206 * be of the form:
207 *
208 * [<domain>:]<bus>:<device>.<func>[/<device>.<func>]*
209 *
210 * A path for a device can be obtained using 'lspci -t'. Using a path
211 * is more robust against bus renumbering than using only a single bus,
212 * device and function address.
213 *
214 * Returns 1 if the string matches the device, 0 if it does not and
215 * a negative error code if it fails to parse the string.
216 */
217static int pci_dev_str_match_path(struct pci_dev *dev, const char *path,
218 const char **endptr)
219{
220 int ret;
221 int seg, bus, slot, func;
222 char *wpath, *p;
223 char end;
224
225 *endptr = strchrnul(path, ';');
226
227 wpath = kmemdup_nul(path, *endptr - path, GFP_KERNEL);
228 if (!wpath)
229 return -ENOMEM;
230
231 while (1) {
232 p = strrchr(wpath, '/');
233 if (!p)
234 break;
235 ret = sscanf(p, "/%x.%x%c", &slot, &func, &end);
236 if (ret != 2) {
237 ret = -EINVAL;
238 goto free_and_exit;
239 }
240
241 if (dev->devfn != PCI_DEVFN(slot, func)) {
242 ret = 0;
243 goto free_and_exit;
244 }
245
246 /*
247 * Note: we don't need to get a reference to the upstream
248 * bridge because we hold a reference to the top level
249 * device which should hold a reference to the bridge,
250 * and so on.
251 */
252 dev = pci_upstream_bridge(dev);
253 if (!dev) {
254 ret = 0;
255 goto free_and_exit;
256 }
257
258 *p = 0;
259 }
260
261 ret = sscanf(wpath, "%x:%x:%x.%x%c", &seg, &bus, &slot,
262 &func, &end);
263 if (ret != 4) {
264 seg = 0;
265 ret = sscanf(wpath, "%x:%x.%x%c", &bus, &slot, &func, &end);
266 if (ret != 3) {
267 ret = -EINVAL;
268 goto free_and_exit;
269 }
270 }
271
272 ret = (seg == pci_domain_nr(dev->bus) &&
273 bus == dev->bus->number &&
274 dev->devfn == PCI_DEVFN(slot, func));
275
276free_and_exit:
277 kfree(wpath);
278 return ret;
279}
280
281/**
282 * pci_dev_str_match - test if a string matches a device
283 * @dev: the PCI device to test
284 * @p: string to match the device against
285 * @endptr: pointer to the string after the match
286 *
287 * Test if a string (typically from a kernel parameter) matches a specified
288 * PCI device. The string may be of one of the following formats:
289 *
290 * [<domain>:]<bus>:<device>.<func>[/<device>.<func>]*
291 * pci:<vendor>:<device>[:<subvendor>:<subdevice>]
292 *
293 * The first format specifies a PCI bus/device/function address which
294 * may change if new hardware is inserted, if motherboard firmware changes,
295 * or due to changes caused in kernel parameters. If the domain is
296 * left unspecified, it is taken to be 0. In order to be robust against
297 * bus renumbering issues, a path of PCI device/function numbers may be used
298 * to address the specific device. The path for a device can be determined
299 * through the use of 'lspci -t'.
300 *
301 * The second format matches devices using IDs in the configuration
302 * space which may match multiple devices in the system. A value of 0
303 * for any field will match all devices. (Note: this differs from
304 * in-kernel code that uses PCI_ANY_ID which is ~0; this is for
305 * legacy reasons and convenience so users don't have to specify
306 * FFFFFFFFs on the command line.)
307 *
308 * Returns 1 if the string matches the device, 0 if it does not and
309 * a negative error code if the string cannot be parsed.
310 */
311static int pci_dev_str_match(struct pci_dev *dev, const char *p,
312 const char **endptr)
313{
314 int ret;
315 int count;
316 unsigned short vendor, device, subsystem_vendor, subsystem_device;
317
318 if (strncmp(p, "pci:", 4) == 0) {
319 /* PCI vendor/device (subvendor/subdevice) IDs are specified */
320 p += 4;
321 ret = sscanf(p, "%hx:%hx:%hx:%hx%n", &vendor, &device,
322 &subsystem_vendor, &subsystem_device, &count);
323 if (ret != 4) {
324 ret = sscanf(p, "%hx:%hx%n", &vendor, &device, &count);
325 if (ret != 2)
326 return -EINVAL;
327
328 subsystem_vendor = 0;
329 subsystem_device = 0;
330 }
331
332 p += count;
333
334 if ((!vendor || vendor == dev->vendor) &&
335 (!device || device == dev->device) &&
336 (!subsystem_vendor ||
337 subsystem_vendor == dev->subsystem_vendor) &&
338 (!subsystem_device ||
339 subsystem_device == dev->subsystem_device))
340 goto found;
341 } else {
342 /*
343 * PCI Bus, Device, Function IDs are specified
344 * (optionally, may include a path of devfns following it)
345 */
346 ret = pci_dev_str_match_path(dev, p, &p);
347 if (ret < 0)
348 return ret;
349 else if (ret)
350 goto found;
351 }
352
353 *endptr = p;
354 return 0;
355
356found:
357 *endptr = p;
358 return 1;
359}
360
361static int __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn,
362 u8 pos, int cap, int *ttl)
363{
364 u8 id;
365 u16 ent;
366
367 pci_bus_read_config_byte(bus, devfn, pos, &pos);
368
369 while ((*ttl)--) {
370 if (pos < 0x40)
371 break;
372 pos &= ~3;
373 pci_bus_read_config_word(bus, devfn, pos, &ent);
374
375 id = ent & 0xff;
376 if (id == 0xff)
377 break;
378 if (id == cap)
379 return pos;
380 pos = (ent >> 8);
381 }
382 return 0;
383}
384
385static int __pci_find_next_cap(struct pci_bus *bus, unsigned int devfn,
386 u8 pos, int cap)
387{
388 int ttl = PCI_FIND_CAP_TTL;
389
390 return __pci_find_next_cap_ttl(bus, devfn, pos, cap, &ttl);
391}
392
393int pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap)
394{
395 return __pci_find_next_cap(dev->bus, dev->devfn,
396 pos + PCI_CAP_LIST_NEXT, cap);
397}
398EXPORT_SYMBOL_GPL(pci_find_next_capability);
399
400static int __pci_bus_find_cap_start(struct pci_bus *bus,
401 unsigned int devfn, u8 hdr_type)
402{
403 u16 status;
404
405 pci_bus_read_config_word(bus, devfn, PCI_STATUS, &status);
406 if (!(status & PCI_STATUS_CAP_LIST))
407 return 0;
408
409 switch (hdr_type) {
410 case PCI_HEADER_TYPE_NORMAL:
411 case PCI_HEADER_TYPE_BRIDGE:
412 return PCI_CAPABILITY_LIST;
413 case PCI_HEADER_TYPE_CARDBUS:
414 return PCI_CB_CAPABILITY_LIST;
415 }
416
417 return 0;
418}
419
420/**
421 * pci_find_capability - query for devices' capabilities
422 * @dev: PCI device to query
423 * @cap: capability code
424 *
425 * Tell if a device supports a given PCI capability.
426 * Returns the address of the requested capability structure within the
427 * device's PCI configuration space or 0 in case the device does not
428 * support it. Possible values for @cap include:
429 *
430 * %PCI_CAP_ID_PM Power Management
431 * %PCI_CAP_ID_AGP Accelerated Graphics Port
432 * %PCI_CAP_ID_VPD Vital Product Data
433 * %PCI_CAP_ID_SLOTID Slot Identification
434 * %PCI_CAP_ID_MSI Message Signalled Interrupts
435 * %PCI_CAP_ID_CHSWP CompactPCI HotSwap
436 * %PCI_CAP_ID_PCIX PCI-X
437 * %PCI_CAP_ID_EXP PCI Express
438 */
439int pci_find_capability(struct pci_dev *dev, int cap)
440{
441 int pos;
442
443 pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);
444 if (pos)
445 pos = __pci_find_next_cap(dev->bus, dev->devfn, pos, cap);
446
447 return pos;
448}
449EXPORT_SYMBOL(pci_find_capability);
450
451/**
452 * pci_bus_find_capability - query for devices' capabilities
453 * @bus: the PCI bus to query
454 * @devfn: PCI device to query
455 * @cap: capability code
456 *
457 * Like pci_find_capability() but works for PCI devices that do not have a
458 * pci_dev structure set up yet.
459 *
460 * Returns the address of the requested capability structure within the
461 * device's PCI configuration space or 0 in case the device does not
462 * support it.
463 */
464int pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap)
465{
466 int pos;
467 u8 hdr_type;
468
469 pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &hdr_type);
470
471 pos = __pci_bus_find_cap_start(bus, devfn, hdr_type & 0x7f);
472 if (pos)
473 pos = __pci_find_next_cap(bus, devfn, pos, cap);
474
475 return pos;
476}
477EXPORT_SYMBOL(pci_bus_find_capability);
478
479/**
480 * pci_find_next_ext_capability - Find an extended capability
481 * @dev: PCI device to query
482 * @start: address at which to start looking (0 to start at beginning of list)
483 * @cap: capability code
484 *
485 * Returns the address of the next matching extended capability structure
486 * within the device's PCI configuration space or 0 if the device does
487 * not support it. Some capabilities can occur several times, e.g., the
488 * vendor-specific capability, and this provides a way to find them all.
489 */
490int pci_find_next_ext_capability(struct pci_dev *dev, int start, int cap)
491{
492 u32 header;
493 int ttl;
494 int pos = PCI_CFG_SPACE_SIZE;
495
496 /* minimum 8 bytes per capability */
497 ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8;
498
499 if (dev->cfg_size <= PCI_CFG_SPACE_SIZE)
500 return 0;
501
502 if (start)
503 pos = start;
504
505 if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
506 return 0;
507
508 /*
509 * If we have no capabilities, this is indicated by cap ID,
510 * cap version and next pointer all being 0.
511 */
512 if (header == 0)
513 return 0;
514
515 while (ttl-- > 0) {
516 if (PCI_EXT_CAP_ID(header) == cap && pos != start)
517 return pos;
518
519 pos = PCI_EXT_CAP_NEXT(header);
520 if (pos < PCI_CFG_SPACE_SIZE)
521 break;
522
523 if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
524 break;
525 }
526
527 return 0;
528}
529EXPORT_SYMBOL_GPL(pci_find_next_ext_capability);
530
531/**
532 * pci_find_ext_capability - Find an extended capability
533 * @dev: PCI device to query
534 * @cap: capability code
535 *
536 * Returns the address of the requested extended capability structure
537 * within the device's PCI configuration space or 0 if the device does
538 * not support it. Possible values for @cap include:
539 *
540 * %PCI_EXT_CAP_ID_ERR Advanced Error Reporting
541 * %PCI_EXT_CAP_ID_VC Virtual Channel
542 * %PCI_EXT_CAP_ID_DSN Device Serial Number
543 * %PCI_EXT_CAP_ID_PWR Power Budgeting
544 */
545int pci_find_ext_capability(struct pci_dev *dev, int cap)
546{
547 return pci_find_next_ext_capability(dev, 0, cap);
548}
549EXPORT_SYMBOL_GPL(pci_find_ext_capability);
550
551static int __pci_find_next_ht_cap(struct pci_dev *dev, int pos, int ht_cap)
552{
553 int rc, ttl = PCI_FIND_CAP_TTL;
554 u8 cap, mask;
555
556 if (ht_cap == HT_CAPTYPE_SLAVE || ht_cap == HT_CAPTYPE_HOST)
557 mask = HT_3BIT_CAP_MASK;
558 else
559 mask = HT_5BIT_CAP_MASK;
560
561 pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn, pos,
562 PCI_CAP_ID_HT, &ttl);
563 while (pos) {
564 rc = pci_read_config_byte(dev, pos + 3, &cap);
565 if (rc != PCIBIOS_SUCCESSFUL)
566 return 0;
567
568 if ((cap & mask) == ht_cap)
569 return pos;
570
571 pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn,
572 pos + PCI_CAP_LIST_NEXT,
573 PCI_CAP_ID_HT, &ttl);
574 }
575
576 return 0;
577}
578/**
579 * pci_find_next_ht_capability - query a device's Hypertransport capabilities
580 * @dev: PCI device to query
581 * @pos: Position from which to continue searching
582 * @ht_cap: Hypertransport capability code
583 *
584 * To be used in conjunction with pci_find_ht_capability() to search for
585 * all capabilities matching @ht_cap. @pos should always be a value returned
586 * from pci_find_ht_capability().
587 *
588 * NB. To be 100% safe against broken PCI devices, the caller should take
589 * steps to avoid an infinite loop.
590 */
591int pci_find_next_ht_capability(struct pci_dev *dev, int pos, int ht_cap)
592{
593 return __pci_find_next_ht_cap(dev, pos + PCI_CAP_LIST_NEXT, ht_cap);
594}
595EXPORT_SYMBOL_GPL(pci_find_next_ht_capability);
596
597/**
598 * pci_find_ht_capability - query a device's Hypertransport capabilities
599 * @dev: PCI device to query
600 * @ht_cap: Hypertransport capability code
601 *
602 * Tell if a device supports a given Hypertransport capability.
603 * Returns an address within the device's PCI configuration space
604 * or 0 in case the device does not support the request capability.
605 * The address points to the PCI capability, of type PCI_CAP_ID_HT,
606 * which has a Hypertransport capability matching @ht_cap.
607 */
608int pci_find_ht_capability(struct pci_dev *dev, int ht_cap)
609{
610 int pos;
611
612 pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);
613 if (pos)
614 pos = __pci_find_next_ht_cap(dev, pos, ht_cap);
615
616 return pos;
617}
618EXPORT_SYMBOL_GPL(pci_find_ht_capability);
619
620/**
621 * pci_find_parent_resource - return resource region of parent bus of given
622 * region
623 * @dev: PCI device structure contains resources to be searched
624 * @res: child resource record for which parent is sought
625 *
626 * For given resource region of given device, return the resource region of
627 * parent bus the given region is contained in.
628 */
629struct resource *pci_find_parent_resource(const struct pci_dev *dev,
630 struct resource *res)
631{
632 const struct pci_bus *bus = dev->bus;
633 struct resource *r;
634 int i;
635
636 pci_bus_for_each_resource(bus, r, i) {
637 if (!r)
638 continue;
639 if (resource_contains(r, res)) {
640
641 /*
642 * If the window is prefetchable but the BAR is
643 * not, the allocator made a mistake.
644 */
645 if (r->flags & IORESOURCE_PREFETCH &&
646 !(res->flags & IORESOURCE_PREFETCH))
647 return NULL;
648
649 /*
650 * If we're below a transparent bridge, there may
651 * be both a positively-decoded aperture and a
652 * subtractively-decoded region that contain the BAR.
653 * We want the positively-decoded one, so this depends
654 * on pci_bus_for_each_resource() giving us those
655 * first.
656 */
657 return r;
658 }
659 }
660 return NULL;
661}
662EXPORT_SYMBOL(pci_find_parent_resource);
663
664/**
665 * pci_find_resource - Return matching PCI device resource
666 * @dev: PCI device to query
667 * @res: Resource to look for
668 *
669 * Goes over standard PCI resources (BARs) and checks if the given resource
670 * is partially or fully contained in any of them. In that case the
671 * matching resource is returned, %NULL otherwise.
672 */
673struct resource *pci_find_resource(struct pci_dev *dev, struct resource *res)
674{
675 int i;
676
677 for (i = 0; i < PCI_ROM_RESOURCE; i++) {
678 struct resource *r = &dev->resource[i];
679
680 if (r->start && resource_contains(r, res))
681 return r;
682 }
683
684 return NULL;
685}
686EXPORT_SYMBOL(pci_find_resource);
687
688/**
689 * pci_find_pcie_root_port - return PCIe Root Port
690 * @dev: PCI device to query
691 *
692 * Traverse up the parent chain and return the PCIe Root Port PCI Device
693 * for a given PCI Device.
694 */
695struct pci_dev *pci_find_pcie_root_port(struct pci_dev *dev)
696{
697 struct pci_dev *bridge, *highest_pcie_bridge = dev;
698
699 bridge = pci_upstream_bridge(dev);
700 while (bridge && pci_is_pcie(bridge)) {
701 highest_pcie_bridge = bridge;
702 bridge = pci_upstream_bridge(bridge);
703 }
704
705 if (pci_pcie_type(highest_pcie_bridge) != PCI_EXP_TYPE_ROOT_PORT)
706 return NULL;
707
708 return highest_pcie_bridge;
709}
710EXPORT_SYMBOL(pci_find_pcie_root_port);
711
712/**
713 * pci_wait_for_pending - wait for @mask bit(s) to clear in status word @pos
714 * @dev: the PCI device to operate on
715 * @pos: config space offset of status word
716 * @mask: mask of bit(s) to care about in status word
717 *
718 * Return 1 when mask bit(s) in status word clear, 0 otherwise.
719 */
720int pci_wait_for_pending(struct pci_dev *dev, int pos, u16 mask)
721{
722 int i;
723
724 /* Wait for Transaction Pending bit clean */
725 for (i = 0; i < 4; i++) {
726 u16 status;
727 if (i)
728 msleep((1 << (i - 1)) * 100);
729
730 pci_read_config_word(dev, pos, &status);
731 if (!(status & mask))
732 return 1;
733 }
734
735 return 0;
736}
737
738/**
739 * pci_restore_bars - restore a device's BAR values (e.g. after wake-up)
740 * @dev: PCI device to have its BARs restored
741 *
742 * Restore the BAR values for a given device, so as to make it
743 * accessible by its driver.
744 */
745static void pci_restore_bars(struct pci_dev *dev)
746{
747 int i;
748
749 for (i = 0; i < PCI_BRIDGE_RESOURCES; i++)
750 pci_update_resource(dev, i);
751}
752
753static const struct pci_platform_pm_ops *pci_platform_pm;
754
755int pci_set_platform_pm(const struct pci_platform_pm_ops *ops)
756{
757 if (!ops->is_manageable || !ops->set_state || !ops->get_state ||
758 !ops->choose_state || !ops->set_wakeup || !ops->need_resume)
759 return -EINVAL;
760 pci_platform_pm = ops;
761 return 0;
762}
763
764static inline bool platform_pci_power_manageable(struct pci_dev *dev)
765{
766 return pci_platform_pm ? pci_platform_pm->is_manageable(dev) : false;
767}
768
769static inline int platform_pci_set_power_state(struct pci_dev *dev,
770 pci_power_t t)
771{
772 return pci_platform_pm ? pci_platform_pm->set_state(dev, t) : -ENOSYS;
773}
774
775static inline pci_power_t platform_pci_get_power_state(struct pci_dev *dev)
776{
777 return pci_platform_pm ? pci_platform_pm->get_state(dev) : PCI_UNKNOWN;
778}
779
780static inline void platform_pci_refresh_power_state(struct pci_dev *dev)
781{
782 if (pci_platform_pm && pci_platform_pm->refresh_state)
783 pci_platform_pm->refresh_state(dev);
784}
785
786static inline pci_power_t platform_pci_choose_state(struct pci_dev *dev)
787{
788 return pci_platform_pm ?
789 pci_platform_pm->choose_state(dev) : PCI_POWER_ERROR;
790}
791
792static inline int platform_pci_set_wakeup(struct pci_dev *dev, bool enable)
793{
794 return pci_platform_pm ?
795 pci_platform_pm->set_wakeup(dev, enable) : -ENODEV;
796}
797
798static inline bool platform_pci_need_resume(struct pci_dev *dev)
799{
800 return pci_platform_pm ? pci_platform_pm->need_resume(dev) : false;
801}
802
803static inline bool platform_pci_bridge_d3(struct pci_dev *dev)
804{
805 return pci_platform_pm ? pci_platform_pm->bridge_d3(dev) : false;
806}
807
808/**
809 * pci_raw_set_power_state - Use PCI PM registers to set the power state of
810 * given PCI device
811 * @dev: PCI device to handle.
812 * @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
813 *
814 * RETURN VALUE:
815 * -EINVAL if the requested state is invalid.
816 * -EIO if device does not support PCI PM or its PM capabilities register has a
817 * wrong version, or device doesn't support the requested state.
818 * 0 if device already is in the requested state.
819 * 0 if device's power state has been successfully changed.
820 */
821static int pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
822{
823 u16 pmcsr;
824 bool need_restore = false;
825
826 /* Check if we're already there */
827 if (dev->current_state == state)
828 return 0;
829
830 if (!dev->pm_cap)
831 return -EIO;
832
833 if (state < PCI_D0 || state > PCI_D3hot)
834 return -EINVAL;
835
836 /*
837 * Validate current state:
838 * Can enter D0 from any state, but if we can only go deeper
839 * to sleep if we're already in a low power state
840 */
841 if (state != PCI_D0 && dev->current_state <= PCI_D3cold
842 && dev->current_state > state) {
843 pci_err(dev, "invalid power transition (from state %d to %d)\n",
844 dev->current_state, state);
845 return -EINVAL;
846 }
847
848 /* Check if this device supports the desired state */
849 if ((state == PCI_D1 && !dev->d1_support)
850 || (state == PCI_D2 && !dev->d2_support))
851 return -EIO;
852
853 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
854
855 /*
856 * If we're (effectively) in D3, force entire word to 0.
857 * This doesn't affect PME_Status, disables PME_En, and
858 * sets PowerState to 0.
859 */
860 switch (dev->current_state) {
861 case PCI_D0:
862 case PCI_D1:
863 case PCI_D2:
864 pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
865 pmcsr |= state;
866 break;
867 case PCI_D3hot:
868 case PCI_D3cold:
869 case PCI_UNKNOWN: /* Boot-up */
870 if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot
871 && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))
872 need_restore = true;
873 /* Fall-through - force to D0 */
874 default:
875 pmcsr = 0;
876 break;
877 }
878
879 /* Enter specified state */
880 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
881
882 /*
883 * Mandatory power management transition delays; see PCI PM 1.1
884 * 5.6.1 table 18
885 */
886 if (state == PCI_D3hot || dev->current_state == PCI_D3hot)
887 pci_dev_d3_sleep(dev);
888 else if (state == PCI_D2 || dev->current_state == PCI_D2)
889 udelay(PCI_PM_D2_DELAY);
890
891 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
892 dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
893 if (dev->current_state != state)
894 pci_info_ratelimited(dev, "Refused to change power state, currently in D%d\n",
895 dev->current_state);
896
897 /*
898 * According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT
899 * INTERFACE SPECIFICATION, REV. 1.2", a device transitioning
900 * from D3hot to D0 _may_ perform an internal reset, thereby
901 * going to "D0 Uninitialized" rather than "D0 Initialized".
902 * For example, at least some versions of the 3c905B and the
903 * 3c556B exhibit this behaviour.
904 *
905 * At least some laptop BIOSen (e.g. the Thinkpad T21) leave
906 * devices in a D3hot state at boot. Consequently, we need to
907 * restore at least the BARs so that the device will be
908 * accessible to its driver.
909 */
910 if (need_restore)
911 pci_restore_bars(dev);
912
913 if (dev->bus->self)
914 pcie_aspm_pm_state_change(dev->bus->self);
915
916 return 0;
917}
918
919/**
920 * pci_update_current_state - Read power state of given device and cache it
921 * @dev: PCI device to handle.
922 * @state: State to cache in case the device doesn't have the PM capability
923 *
924 * The power state is read from the PMCSR register, which however is
925 * inaccessible in D3cold. The platform firmware is therefore queried first
926 * to detect accessibility of the register. In case the platform firmware
927 * reports an incorrect state or the device isn't power manageable by the
928 * platform at all, we try to detect D3cold by testing accessibility of the
929 * vendor ID in config space.
930 */
931void pci_update_current_state(struct pci_dev *dev, pci_power_t state)
932{
933 if (platform_pci_get_power_state(dev) == PCI_D3cold ||
934 !pci_device_is_present(dev)) {
935 dev->current_state = PCI_D3cold;
936 } else if (dev->pm_cap) {
937 u16 pmcsr;
938
939 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
940 dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
941 } else {
942 dev->current_state = state;
943 }
944}
945
946/**
947 * pci_refresh_power_state - Refresh the given device's power state data
948 * @dev: Target PCI device.
949 *
950 * Ask the platform to refresh the devices power state information and invoke
951 * pci_update_current_state() to update its current PCI power state.
952 */
953void pci_refresh_power_state(struct pci_dev *dev)
954{
955 if (platform_pci_power_manageable(dev))
956 platform_pci_refresh_power_state(dev);
957
958 pci_update_current_state(dev, dev->current_state);
959}
960
961/**
962 * pci_platform_power_transition - Use platform to change device power state
963 * @dev: PCI device to handle.
964 * @state: State to put the device into.
965 */
966static int pci_platform_power_transition(struct pci_dev *dev, pci_power_t state)
967{
968 int error;
969
970 if (platform_pci_power_manageable(dev)) {
971 error = platform_pci_set_power_state(dev, state);
972 if (!error)
973 pci_update_current_state(dev, state);
974 } else
975 error = -ENODEV;
976
977 if (error && !dev->pm_cap) /* Fall back to PCI_D0 */
978 dev->current_state = PCI_D0;
979
980 return error;
981}
982
983/**
984 * pci_wakeup - Wake up a PCI device
985 * @pci_dev: Device to handle.
986 * @ign: ignored parameter
987 */
988static int pci_wakeup(struct pci_dev *pci_dev, void *ign)
989{
990 pci_wakeup_event(pci_dev);
991 pm_request_resume(&pci_dev->dev);
992 return 0;
993}
994
995/**
996 * pci_wakeup_bus - Walk given bus and wake up devices on it
997 * @bus: Top bus of the subtree to walk.
998 */
999void pci_wakeup_bus(struct pci_bus *bus)
1000{
1001 if (bus)
1002 pci_walk_bus(bus, pci_wakeup, NULL);
1003}
1004
1005/**
1006 * __pci_start_power_transition - Start power transition of a PCI device
1007 * @dev: PCI device to handle.
1008 * @state: State to put the device into.
1009 */
1010static void __pci_start_power_transition(struct pci_dev *dev, pci_power_t state)
1011{
1012 if (state == PCI_D0) {
1013 pci_platform_power_transition(dev, PCI_D0);
1014 /*
1015 * Mandatory power management transition delays, see
1016 * PCI Express Base Specification Revision 2.0 Section
1017 * 6.6.1: Conventional Reset. Do not delay for
1018 * devices powered on/off by corresponding bridge,
1019 * because have already delayed for the bridge.
1020 */
1021 if (dev->runtime_d3cold) {
1022 if (dev->d3cold_delay && !dev->imm_ready)
1023 msleep(dev->d3cold_delay);
1024 /*
1025 * When powering on a bridge from D3cold, the
1026 * whole hierarchy may be powered on into
1027 * D0uninitialized state, resume them to give
1028 * them a chance to suspend again
1029 */
1030 pci_wakeup_bus(dev->subordinate);
1031 }
1032 }
1033}
1034
1035/**
1036 * __pci_dev_set_current_state - Set current state of a PCI device
1037 * @dev: Device to handle
1038 * @data: pointer to state to be set
1039 */
1040static int __pci_dev_set_current_state(struct pci_dev *dev, void *data)
1041{
1042 pci_power_t state = *(pci_power_t *)data;
1043
1044 dev->current_state = state;
1045 return 0;
1046}
1047
1048/**
1049 * pci_bus_set_current_state - Walk given bus and set current state of devices
1050 * @bus: Top bus of the subtree to walk.
1051 * @state: state to be set
1052 */
1053void pci_bus_set_current_state(struct pci_bus *bus, pci_power_t state)
1054{
1055 if (bus)
1056 pci_walk_bus(bus, __pci_dev_set_current_state, &state);
1057}
1058
1059/**
1060 * __pci_complete_power_transition - Complete power transition of a PCI device
1061 * @dev: PCI device to handle.
1062 * @state: State to put the device into.
1063 *
1064 * This function should not be called directly by device drivers.
1065 */
1066int __pci_complete_power_transition(struct pci_dev *dev, pci_power_t state)
1067{
1068 int ret;
1069
1070 if (state <= PCI_D0)
1071 return -EINVAL;
1072 ret = pci_platform_power_transition(dev, state);
1073 /* Power off the bridge may power off the whole hierarchy */
1074 if (!ret && state == PCI_D3cold)
1075 pci_bus_set_current_state(dev->subordinate, PCI_D3cold);
1076 return ret;
1077}
1078EXPORT_SYMBOL_GPL(__pci_complete_power_transition);
1079
1080/**
1081 * pci_set_power_state - Set the power state of a PCI device
1082 * @dev: PCI device to handle.
1083 * @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
1084 *
1085 * Transition a device to a new power state, using the platform firmware and/or
1086 * the device's PCI PM registers.
1087 *
1088 * RETURN VALUE:
1089 * -EINVAL if the requested state is invalid.
1090 * -EIO if device does not support PCI PM or its PM capabilities register has a
1091 * wrong version, or device doesn't support the requested state.
1092 * 0 if the transition is to D1 or D2 but D1 and D2 are not supported.
1093 * 0 if device already is in the requested state.
1094 * 0 if the transition is to D3 but D3 is not supported.
1095 * 0 if device's power state has been successfully changed.
1096 */
1097int pci_set_power_state(struct pci_dev *dev, pci_power_t state)
1098{
1099 int error;
1100
1101 /* Bound the state we're entering */
1102 if (state > PCI_D3cold)
1103 state = PCI_D3cold;
1104 else if (state < PCI_D0)
1105 state = PCI_D0;
1106 else if ((state == PCI_D1 || state == PCI_D2) && pci_no_d1d2(dev))
1107
1108 /*
1109 * If the device or the parent bridge do not support PCI
1110 * PM, ignore the request if we're doing anything other
1111 * than putting it into D0 (which would only happen on
1112 * boot).
1113 */
1114 return 0;
1115
1116 /* Check if we're already there */
1117 if (dev->current_state == state)
1118 return 0;
1119
1120 __pci_start_power_transition(dev, state);
1121
1122 /*
1123 * This device is quirked not to be put into D3, so don't put it in
1124 * D3
1125 */
1126 if (state >= PCI_D3hot && (dev->dev_flags & PCI_DEV_FLAGS_NO_D3))
1127 return 0;
1128
1129 /*
1130 * To put device in D3cold, we put device into D3hot in native
1131 * way, then put device into D3cold with platform ops
1132 */
1133 error = pci_raw_set_power_state(dev, state > PCI_D3hot ?
1134 PCI_D3hot : state);
1135
1136 if (!__pci_complete_power_transition(dev, state))
1137 error = 0;
1138
1139 return error;
1140}
1141EXPORT_SYMBOL(pci_set_power_state);
1142
1143/**
1144 * pci_power_up - Put the given device into D0 forcibly
1145 * @dev: PCI device to power up
1146 */
1147void pci_power_up(struct pci_dev *dev)
1148{
1149 __pci_start_power_transition(dev, PCI_D0);
1150 pci_raw_set_power_state(dev, PCI_D0);
1151 pci_update_current_state(dev, PCI_D0);
1152}
1153
1154/**
1155 * pci_choose_state - Choose the power state of a PCI device
1156 * @dev: PCI device to be suspended
1157 * @state: target sleep state for the whole system. This is the value
1158 * that is passed to suspend() function.
1159 *
1160 * Returns PCI power state suitable for given device and given system
1161 * message.
1162 */
1163pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state)
1164{
1165 pci_power_t ret;
1166
1167 if (!dev->pm_cap)
1168 return PCI_D0;
1169
1170 ret = platform_pci_choose_state(dev);
1171 if (ret != PCI_POWER_ERROR)
1172 return ret;
1173
1174 switch (state.event) {
1175 case PM_EVENT_ON:
1176 return PCI_D0;
1177 case PM_EVENT_FREEZE:
1178 case PM_EVENT_PRETHAW:
1179 /* REVISIT both freeze and pre-thaw "should" use D0 */
1180 case PM_EVENT_SUSPEND:
1181 case PM_EVENT_HIBERNATE:
1182 return PCI_D3hot;
1183 default:
1184 pci_info(dev, "unrecognized suspend event %d\n",
1185 state.event);
1186 BUG();
1187 }
1188 return PCI_D0;
1189}
1190EXPORT_SYMBOL(pci_choose_state);
1191
1192#define PCI_EXP_SAVE_REGS 7
1193
1194static struct pci_cap_saved_state *_pci_find_saved_cap(struct pci_dev *pci_dev,
1195 u16 cap, bool extended)
1196{
1197 struct pci_cap_saved_state *tmp;
1198
1199 hlist_for_each_entry(tmp, &pci_dev->saved_cap_space, next) {
1200 if (tmp->cap.cap_extended == extended && tmp->cap.cap_nr == cap)
1201 return tmp;
1202 }
1203 return NULL;
1204}
1205
1206struct pci_cap_saved_state *pci_find_saved_cap(struct pci_dev *dev, char cap)
1207{
1208 return _pci_find_saved_cap(dev, cap, false);
1209}
1210
1211struct pci_cap_saved_state *pci_find_saved_ext_cap(struct pci_dev *dev, u16 cap)
1212{
1213 return _pci_find_saved_cap(dev, cap, true);
1214}
1215
1216static int pci_save_pcie_state(struct pci_dev *dev)
1217{
1218 int i = 0;
1219 struct pci_cap_saved_state *save_state;
1220 u16 *cap;
1221
1222 if (!pci_is_pcie(dev))
1223 return 0;
1224
1225 save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
1226 if (!save_state) {
1227 pci_err(dev, "buffer not found in %s\n", __func__);
1228 return -ENOMEM;
1229 }
1230
1231 cap = (u16 *)&save_state->cap.data[0];
1232 pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &cap[i++]);
1233 pcie_capability_read_word(dev, PCI_EXP_LNKCTL, &cap[i++]);
1234 pcie_capability_read_word(dev, PCI_EXP_SLTCTL, &cap[i++]);
1235 pcie_capability_read_word(dev, PCI_EXP_RTCTL, &cap[i++]);
1236 pcie_capability_read_word(dev, PCI_EXP_DEVCTL2, &cap[i++]);
1237 pcie_capability_read_word(dev, PCI_EXP_LNKCTL2, &cap[i++]);
1238 pcie_capability_read_word(dev, PCI_EXP_SLTCTL2, &cap[i++]);
1239
1240 return 0;
1241}
1242
1243static void pci_restore_pcie_state(struct pci_dev *dev)
1244{
1245 int i = 0;
1246 struct pci_cap_saved_state *save_state;
1247 u16 *cap;
1248
1249 save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
1250 if (!save_state)
1251 return;
1252
1253 cap = (u16 *)&save_state->cap.data[0];
1254 pcie_capability_write_word(dev, PCI_EXP_DEVCTL, cap[i++]);
1255 pcie_capability_write_word(dev, PCI_EXP_LNKCTL, cap[i++]);
1256 pcie_capability_write_word(dev, PCI_EXP_SLTCTL, cap[i++]);
1257 pcie_capability_write_word(dev, PCI_EXP_RTCTL, cap[i++]);
1258 pcie_capability_write_word(dev, PCI_EXP_DEVCTL2, cap[i++]);
1259 pcie_capability_write_word(dev, PCI_EXP_LNKCTL2, cap[i++]);
1260 pcie_capability_write_word(dev, PCI_EXP_SLTCTL2, cap[i++]);
1261}
1262
1263static int pci_save_pcix_state(struct pci_dev *dev)
1264{
1265 int pos;
1266 struct pci_cap_saved_state *save_state;
1267
1268 pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
1269 if (!pos)
1270 return 0;
1271
1272 save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX);
1273 if (!save_state) {
1274 pci_err(dev, "buffer not found in %s\n", __func__);
1275 return -ENOMEM;
1276 }
1277
1278 pci_read_config_word(dev, pos + PCI_X_CMD,
1279 (u16 *)save_state->cap.data);
1280
1281 return 0;
1282}
1283
1284static void pci_restore_pcix_state(struct pci_dev *dev)
1285{
1286 int i = 0, pos;
1287 struct pci_cap_saved_state *save_state;
1288 u16 *cap;
1289
1290 save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX);
1291 pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
1292 if (!save_state || !pos)
1293 return;
1294 cap = (u16 *)&save_state->cap.data[0];
1295
1296 pci_write_config_word(dev, pos + PCI_X_CMD, cap[i++]);
1297}
1298
1299static void pci_save_ltr_state(struct pci_dev *dev)
1300{
1301 int ltr;
1302 struct pci_cap_saved_state *save_state;
1303 u16 *cap;
1304
1305 if (!pci_is_pcie(dev))
1306 return;
1307
1308 ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR);
1309 if (!ltr)
1310 return;
1311
1312 save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR);
1313 if (!save_state) {
1314 pci_err(dev, "no suspend buffer for LTR; ASPM issues possible after resume\n");
1315 return;
1316 }
1317
1318 cap = (u16 *)&save_state->cap.data[0];
1319 pci_read_config_word(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, cap++);
1320 pci_read_config_word(dev, ltr + PCI_LTR_MAX_NOSNOOP_LAT, cap++);
1321}
1322
1323static void pci_restore_ltr_state(struct pci_dev *dev)
1324{
1325 struct pci_cap_saved_state *save_state;
1326 int ltr;
1327 u16 *cap;
1328
1329 save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR);
1330 ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR);
1331 if (!save_state || !ltr)
1332 return;
1333
1334 cap = (u16 *)&save_state->cap.data[0];
1335 pci_write_config_word(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, *cap++);
1336 pci_write_config_word(dev, ltr + PCI_LTR_MAX_NOSNOOP_LAT, *cap++);
1337}
1338
1339/**
1340 * pci_save_state - save the PCI configuration space of a device before
1341 * suspending
1342 * @dev: PCI device that we're dealing with
1343 */
1344int pci_save_state(struct pci_dev *dev)
1345{
1346 int i;
1347 /* XXX: 100% dword access ok here? */
1348 for (i = 0; i < 16; i++)
1349 pci_read_config_dword(dev, i * 4, &dev->saved_config_space[i]);
1350 dev->state_saved = true;
1351
1352 i = pci_save_pcie_state(dev);
1353 if (i != 0)
1354 return i;
1355
1356 i = pci_save_pcix_state(dev);
1357 if (i != 0)
1358 return i;
1359
1360 pci_save_ltr_state(dev);
1361 pci_save_dpc_state(dev);
1362 return pci_save_vc_state(dev);
1363}
1364EXPORT_SYMBOL(pci_save_state);
1365
1366static void pci_restore_config_dword(struct pci_dev *pdev, int offset,
1367 u32 saved_val, int retry, bool force)
1368{
1369 u32 val;
1370
1371 pci_read_config_dword(pdev, offset, &val);
1372 if (!force && val == saved_val)
1373 return;
1374
1375 for (;;) {
1376 pci_dbg(pdev, "restoring config space at offset %#x (was %#x, writing %#x)\n",
1377 offset, val, saved_val);
1378 pci_write_config_dword(pdev, offset, saved_val);
1379 if (retry-- <= 0)
1380 return;
1381
1382 pci_read_config_dword(pdev, offset, &val);
1383 if (val == saved_val)
1384 return;
1385
1386 mdelay(1);
1387 }
1388}
1389
1390static void pci_restore_config_space_range(struct pci_dev *pdev,
1391 int start, int end, int retry,
1392 bool force)
1393{
1394 int index;
1395
1396 for (index = end; index >= start; index--)
1397 pci_restore_config_dword(pdev, 4 * index,
1398 pdev->saved_config_space[index],
1399 retry, force);
1400}
1401
1402static void pci_restore_config_space(struct pci_dev *pdev)
1403{
1404 if (pdev->hdr_type == PCI_HEADER_TYPE_NORMAL) {
1405 pci_restore_config_space_range(pdev, 10, 15, 0, false);
1406 /* Restore BARs before the command register. */
1407 pci_restore_config_space_range(pdev, 4, 9, 10, false);
1408 pci_restore_config_space_range(pdev, 0, 3, 0, false);
1409 } else if (pdev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
1410 pci_restore_config_space_range(pdev, 12, 15, 0, false);
1411
1412 /*
1413 * Force rewriting of prefetch registers to avoid S3 resume
1414 * issues on Intel PCI bridges that occur when these
1415 * registers are not explicitly written.
1416 */
1417 pci_restore_config_space_range(pdev, 9, 11, 0, true);
1418 pci_restore_config_space_range(pdev, 0, 8, 0, false);
1419 } else {
1420 pci_restore_config_space_range(pdev, 0, 15, 0, false);
1421 }
1422}
1423
1424static void pci_restore_rebar_state(struct pci_dev *pdev)
1425{
1426 unsigned int pos, nbars, i;
1427 u32 ctrl;
1428
1429 pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR);
1430 if (!pos)
1431 return;
1432
1433 pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
1434 nbars = (ctrl & PCI_REBAR_CTRL_NBAR_MASK) >>
1435 PCI_REBAR_CTRL_NBAR_SHIFT;
1436
1437 for (i = 0; i < nbars; i++, pos += 8) {
1438 struct resource *res;
1439 int bar_idx, size;
1440
1441 pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
1442 bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX;
1443 res = pdev->resource + bar_idx;
1444 size = ilog2(resource_size(res)) - 20;
1445 ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE;
1446 ctrl |= size << PCI_REBAR_CTRL_BAR_SHIFT;
1447 pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl);
1448 }
1449}
1450
1451/**
1452 * pci_restore_state - Restore the saved state of a PCI device
1453 * @dev: PCI device that we're dealing with
1454 */
1455void pci_restore_state(struct pci_dev *dev)
1456{
1457 if (!dev->state_saved)
1458 return;
1459
1460 /*
1461 * Restore max latencies (in the LTR capability) before enabling
1462 * LTR itself (in the PCIe capability).
1463 */
1464 pci_restore_ltr_state(dev);
1465
1466 pci_restore_pcie_state(dev);
1467 pci_restore_pasid_state(dev);
1468 pci_restore_pri_state(dev);
1469 pci_restore_ats_state(dev);
1470 pci_restore_vc_state(dev);
1471 pci_restore_rebar_state(dev);
1472 pci_restore_dpc_state(dev);
1473
1474 pci_cleanup_aer_error_status_regs(dev);
1475
1476 pci_restore_config_space(dev);
1477
1478 pci_restore_pcix_state(dev);
1479 pci_restore_msi_state(dev);
1480
1481 /* Restore ACS and IOV configuration state */
1482 pci_enable_acs(dev);
1483 pci_restore_iov_state(dev);
1484
1485 dev->state_saved = false;
1486}
1487EXPORT_SYMBOL(pci_restore_state);
1488
1489struct pci_saved_state {
1490 u32 config_space[16];
1491 struct pci_cap_saved_data cap[0];
1492};
1493
1494/**
1495 * pci_store_saved_state - Allocate and return an opaque struct containing
1496 * the device saved state.
1497 * @dev: PCI device that we're dealing with
1498 *
1499 * Return NULL if no state or error.
1500 */
1501struct pci_saved_state *pci_store_saved_state(struct pci_dev *dev)
1502{
1503 struct pci_saved_state *state;
1504 struct pci_cap_saved_state *tmp;
1505 struct pci_cap_saved_data *cap;
1506 size_t size;
1507
1508 if (!dev->state_saved)
1509 return NULL;
1510
1511 size = sizeof(*state) + sizeof(struct pci_cap_saved_data);
1512
1513 hlist_for_each_entry(tmp, &dev->saved_cap_space, next)
1514 size += sizeof(struct pci_cap_saved_data) + tmp->cap.size;
1515
1516 state = kzalloc(size, GFP_KERNEL);
1517 if (!state)
1518 return NULL;
1519
1520 memcpy(state->config_space, dev->saved_config_space,
1521 sizeof(state->config_space));
1522
1523 cap = state->cap;
1524 hlist_for_each_entry(tmp, &dev->saved_cap_space, next) {
1525 size_t len = sizeof(struct pci_cap_saved_data) + tmp->cap.size;
1526 memcpy(cap, &tmp->cap, len);
1527 cap = (struct pci_cap_saved_data *)((u8 *)cap + len);
1528 }
1529 /* Empty cap_save terminates list */
1530
1531 return state;
1532}
1533EXPORT_SYMBOL_GPL(pci_store_saved_state);
1534
1535/**
1536 * pci_load_saved_state - Reload the provided save state into struct pci_dev.
1537 * @dev: PCI device that we're dealing with
1538 * @state: Saved state returned from pci_store_saved_state()
1539 */
1540int pci_load_saved_state(struct pci_dev *dev,
1541 struct pci_saved_state *state)
1542{
1543 struct pci_cap_saved_data *cap;
1544
1545 dev->state_saved = false;
1546
1547 if (!state)
1548 return 0;
1549
1550 memcpy(dev->saved_config_space, state->config_space,
1551 sizeof(state->config_space));
1552
1553 cap = state->cap;
1554 while (cap->size) {
1555 struct pci_cap_saved_state *tmp;
1556
1557 tmp = _pci_find_saved_cap(dev, cap->cap_nr, cap->cap_extended);
1558 if (!tmp || tmp->cap.size != cap->size)
1559 return -EINVAL;
1560
1561 memcpy(tmp->cap.data, cap->data, tmp->cap.size);
1562 cap = (struct pci_cap_saved_data *)((u8 *)cap +
1563 sizeof(struct pci_cap_saved_data) + cap->size);
1564 }
1565
1566 dev->state_saved = true;
1567 return 0;
1568}
1569EXPORT_SYMBOL_GPL(pci_load_saved_state);
1570
1571/**
1572 * pci_load_and_free_saved_state - Reload the save state pointed to by state,
1573 * and free the memory allocated for it.
1574 * @dev: PCI device that we're dealing with
1575 * @state: Pointer to saved state returned from pci_store_saved_state()
1576 */
1577int pci_load_and_free_saved_state(struct pci_dev *dev,
1578 struct pci_saved_state **state)
1579{
1580 int ret = pci_load_saved_state(dev, *state);
1581 kfree(*state);
1582 *state = NULL;
1583 return ret;
1584}
1585EXPORT_SYMBOL_GPL(pci_load_and_free_saved_state);
1586
1587int __weak pcibios_enable_device(struct pci_dev *dev, int bars)
1588{
1589 return pci_enable_resources(dev, bars);
1590}
1591
1592static int do_pci_enable_device(struct pci_dev *dev, int bars)
1593{
1594 int err;
1595 struct pci_dev *bridge;
1596 u16 cmd;
1597 u8 pin;
1598
1599 err = pci_set_power_state(dev, PCI_D0);
1600 if (err < 0 && err != -EIO)
1601 return err;
1602
1603 bridge = pci_upstream_bridge(dev);
1604 if (bridge)
1605 pcie_aspm_powersave_config_link(bridge);
1606
1607 err = pcibios_enable_device(dev, bars);
1608 if (err < 0)
1609 return err;
1610 pci_fixup_device(pci_fixup_enable, dev);
1611
1612 if (dev->msi_enabled || dev->msix_enabled)
1613 return 0;
1614
1615 pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
1616 if (pin) {
1617 pci_read_config_word(dev, PCI_COMMAND, &cmd);
1618 if (cmd & PCI_COMMAND_INTX_DISABLE)
1619 pci_write_config_word(dev, PCI_COMMAND,
1620 cmd & ~PCI_COMMAND_INTX_DISABLE);
1621 }
1622
1623 return 0;
1624}
1625
1626/**
1627 * pci_reenable_device - Resume abandoned device
1628 * @dev: PCI device to be resumed
1629 *
1630 * NOTE: This function is a backend of pci_default_resume() and is not supposed
1631 * to be called by normal code, write proper resume handler and use it instead.
1632 */
1633int pci_reenable_device(struct pci_dev *dev)
1634{
1635 if (pci_is_enabled(dev))
1636 return do_pci_enable_device(dev, (1 << PCI_NUM_RESOURCES) - 1);
1637 return 0;
1638}
1639EXPORT_SYMBOL(pci_reenable_device);
1640
1641static void pci_enable_bridge(struct pci_dev *dev)
1642{
1643 struct pci_dev *bridge;
1644 int retval;
1645
1646 bridge = pci_upstream_bridge(dev);
1647 if (bridge)
1648 pci_enable_bridge(bridge);
1649
1650 if (pci_is_enabled(dev)) {
1651 if (!dev->is_busmaster)
1652 pci_set_master(dev);
1653 return;
1654 }
1655
1656 retval = pci_enable_device(dev);
1657 if (retval)
1658 pci_err(dev, "Error enabling bridge (%d), continuing\n",
1659 retval);
1660 pci_set_master(dev);
1661}
1662
1663static int pci_enable_device_flags(struct pci_dev *dev, unsigned long flags)
1664{
1665 struct pci_dev *bridge;
1666 int err;
1667 int i, bars = 0;
1668
1669 /*
1670 * Power state could be unknown at this point, either due to a fresh
1671 * boot or a device removal call. So get the current power state
1672 * so that things like MSI message writing will behave as expected
1673 * (e.g. if the device really is in D0 at enable time).
1674 */
1675 if (dev->pm_cap) {
1676 u16 pmcsr;
1677 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
1678 dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
1679 }
1680
1681 if (atomic_inc_return(&dev->enable_cnt) > 1)
1682 return 0; /* already enabled */
1683
1684 bridge = pci_upstream_bridge(dev);
1685 if (bridge)
1686 pci_enable_bridge(bridge);
1687
1688 /* only skip sriov related */
1689 for (i = 0; i <= PCI_ROM_RESOURCE; i++)
1690 if (dev->resource[i].flags & flags)
1691 bars |= (1 << i);
1692 for (i = PCI_BRIDGE_RESOURCES; i < DEVICE_COUNT_RESOURCE; i++)
1693 if (dev->resource[i].flags & flags)
1694 bars |= (1 << i);
1695
1696 err = do_pci_enable_device(dev, bars);
1697 if (err < 0)
1698 atomic_dec(&dev->enable_cnt);
1699 return err;
1700}
1701
1702/**
1703 * pci_enable_device_io - Initialize a device for use with IO space
1704 * @dev: PCI device to be initialized
1705 *
1706 * Initialize device before it's used by a driver. Ask low-level code
1707 * to enable I/O resources. Wake up the device if it was suspended.
1708 * Beware, this function can fail.
1709 */
1710int pci_enable_device_io(struct pci_dev *dev)
1711{
1712 return pci_enable_device_flags(dev, IORESOURCE_IO);
1713}
1714EXPORT_SYMBOL(pci_enable_device_io);
1715
1716/**
1717 * pci_enable_device_mem - Initialize a device for use with Memory space
1718 * @dev: PCI device to be initialized
1719 *
1720 * Initialize device before it's used by a driver. Ask low-level code
1721 * to enable Memory resources. Wake up the device if it was suspended.
1722 * Beware, this function can fail.
1723 */
1724int pci_enable_device_mem(struct pci_dev *dev)
1725{
1726 return pci_enable_device_flags(dev, IORESOURCE_MEM);
1727}
1728EXPORT_SYMBOL(pci_enable_device_mem);
1729
1730/**
1731 * pci_enable_device - Initialize device before it's used by a driver.
1732 * @dev: PCI device to be initialized
1733 *
1734 * Initialize device before it's used by a driver. Ask low-level code
1735 * to enable I/O and memory. Wake up the device if it was suspended.
1736 * Beware, this function can fail.
1737 *
1738 * Note we don't actually enable the device many times if we call
1739 * this function repeatedly (we just increment the count).
1740 */
1741int pci_enable_device(struct pci_dev *dev)
1742{
1743 return pci_enable_device_flags(dev, IORESOURCE_MEM | IORESOURCE_IO);
1744}
1745EXPORT_SYMBOL(pci_enable_device);
1746
1747/*
1748 * Managed PCI resources. This manages device on/off, INTx/MSI/MSI-X
1749 * on/off and BAR regions. pci_dev itself records MSI/MSI-X status, so
1750 * there's no need to track it separately. pci_devres is initialized
1751 * when a device is enabled using managed PCI device enable interface.
1752 */
1753struct pci_devres {
1754 unsigned int enabled:1;
1755 unsigned int pinned:1;
1756 unsigned int orig_intx:1;
1757 unsigned int restore_intx:1;
1758 unsigned int mwi:1;
1759 u32 region_mask;
1760};
1761
1762static void pcim_release(struct device *gendev, void *res)
1763{
1764 struct pci_dev *dev = to_pci_dev(gendev);
1765 struct pci_devres *this = res;
1766 int i;
1767
1768 if (dev->msi_enabled)
1769 pci_disable_msi(dev);
1770 if (dev->msix_enabled)
1771 pci_disable_msix(dev);
1772
1773 for (i = 0; i < DEVICE_COUNT_RESOURCE; i++)
1774 if (this->region_mask & (1 << i))
1775 pci_release_region(dev, i);
1776
1777 if (this->mwi)
1778 pci_clear_mwi(dev);
1779
1780 if (this->restore_intx)
1781 pci_intx(dev, this->orig_intx);
1782
1783 if (this->enabled && !this->pinned)
1784 pci_disable_device(dev);
1785}
1786
1787static struct pci_devres *get_pci_dr(struct pci_dev *pdev)
1788{
1789 struct pci_devres *dr, *new_dr;
1790
1791 dr = devres_find(&pdev->dev, pcim_release, NULL, NULL);
1792 if (dr)
1793 return dr;
1794
1795 new_dr = devres_alloc(pcim_release, sizeof(*new_dr), GFP_KERNEL);
1796 if (!new_dr)
1797 return NULL;
1798 return devres_get(&pdev->dev, new_dr, NULL, NULL);
1799}
1800
1801static struct pci_devres *find_pci_dr(struct pci_dev *pdev)
1802{
1803 if (pci_is_managed(pdev))
1804 return devres_find(&pdev->dev, pcim_release, NULL, NULL);
1805 return NULL;
1806}
1807
1808/**
1809 * pcim_enable_device - Managed pci_enable_device()
1810 * @pdev: PCI device to be initialized
1811 *
1812 * Managed pci_enable_device().
1813 */
1814int pcim_enable_device(struct pci_dev *pdev)
1815{
1816 struct pci_devres *dr;
1817 int rc;
1818
1819 dr = get_pci_dr(pdev);
1820 if (unlikely(!dr))
1821 return -ENOMEM;
1822 if (dr->enabled)
1823 return 0;
1824
1825 rc = pci_enable_device(pdev);
1826 if (!rc) {
1827 pdev->is_managed = 1;
1828 dr->enabled = 1;
1829 }
1830 return rc;
1831}
1832EXPORT_SYMBOL(pcim_enable_device);
1833
1834/**
1835 * pcim_pin_device - Pin managed PCI device
1836 * @pdev: PCI device to pin
1837 *
1838 * Pin managed PCI device @pdev. Pinned device won't be disabled on
1839 * driver detach. @pdev must have been enabled with
1840 * pcim_enable_device().
1841 */
1842void pcim_pin_device(struct pci_dev *pdev)
1843{
1844 struct pci_devres *dr;
1845
1846 dr = find_pci_dr(pdev);
1847 WARN_ON(!dr || !dr->enabled);
1848 if (dr)
1849 dr->pinned = 1;
1850}
1851EXPORT_SYMBOL(pcim_pin_device);
1852
1853/*
1854 * pcibios_add_device - provide arch specific hooks when adding device dev
1855 * @dev: the PCI device being added
1856 *
1857 * Permits the platform to provide architecture specific functionality when
1858 * devices are added. This is the default implementation. Architecture
1859 * implementations can override this.
1860 */
1861int __weak pcibios_add_device(struct pci_dev *dev)
1862{
1863 return 0;
1864}
1865
1866/**
1867 * pcibios_release_device - provide arch specific hooks when releasing
1868 * device dev
1869 * @dev: the PCI device being released
1870 *
1871 * Permits the platform to provide architecture specific functionality when
1872 * devices are released. This is the default implementation. Architecture
1873 * implementations can override this.
1874 */
1875void __weak pcibios_release_device(struct pci_dev *dev) {}
1876
1877/**
1878 * pcibios_disable_device - disable arch specific PCI resources for device dev
1879 * @dev: the PCI device to disable
1880 *
1881 * Disables architecture specific PCI resources for the device. This
1882 * is the default implementation. Architecture implementations can
1883 * override this.
1884 */
1885void __weak pcibios_disable_device(struct pci_dev *dev) {}
1886
1887/**
1888 * pcibios_penalize_isa_irq - penalize an ISA IRQ
1889 * @irq: ISA IRQ to penalize
1890 * @active: IRQ active or not
1891 *
1892 * Permits the platform to provide architecture-specific functionality when
1893 * penalizing ISA IRQs. This is the default implementation. Architecture
1894 * implementations can override this.
1895 */
1896void __weak pcibios_penalize_isa_irq(int irq, int active) {}
1897
1898static void do_pci_disable_device(struct pci_dev *dev)
1899{
1900 u16 pci_command;
1901
1902 pci_read_config_word(dev, PCI_COMMAND, &pci_command);
1903 if (pci_command & PCI_COMMAND_MASTER) {
1904 pci_command &= ~PCI_COMMAND_MASTER;
1905 pci_write_config_word(dev, PCI_COMMAND, pci_command);
1906 }
1907
1908 pcibios_disable_device(dev);
1909}
1910
1911/**
1912 * pci_disable_enabled_device - Disable device without updating enable_cnt
1913 * @dev: PCI device to disable
1914 *
1915 * NOTE: This function is a backend of PCI power management routines and is
1916 * not supposed to be called drivers.
1917 */
1918void pci_disable_enabled_device(struct pci_dev *dev)
1919{
1920 if (pci_is_enabled(dev))
1921 do_pci_disable_device(dev);
1922}
1923
1924/**
1925 * pci_disable_device - Disable PCI device after use
1926 * @dev: PCI device to be disabled
1927 *
1928 * Signal to the system that the PCI device is not in use by the system
1929 * anymore. This only involves disabling PCI bus-mastering, if active.
1930 *
1931 * Note we don't actually disable the device until all callers of
1932 * pci_enable_device() have called pci_disable_device().
1933 */
1934void pci_disable_device(struct pci_dev *dev)
1935{
1936 struct pci_devres *dr;
1937
1938 dr = find_pci_dr(dev);
1939 if (dr)
1940 dr->enabled = 0;
1941
1942 dev_WARN_ONCE(&dev->dev, atomic_read(&dev->enable_cnt) <= 0,
1943 "disabling already-disabled device");
1944
1945 if (atomic_dec_return(&dev->enable_cnt) != 0)
1946 return;
1947
1948 do_pci_disable_device(dev);
1949
1950 dev->is_busmaster = 0;
1951}
1952EXPORT_SYMBOL(pci_disable_device);
1953
1954/**
1955 * pcibios_set_pcie_reset_state - set reset state for device dev
1956 * @dev: the PCIe device reset
1957 * @state: Reset state to enter into
1958 *
1959 * Set the PCIe reset state for the device. This is the default
1960 * implementation. Architecture implementations can override this.
1961 */
1962int __weak pcibios_set_pcie_reset_state(struct pci_dev *dev,
1963 enum pcie_reset_state state)
1964{
1965 return -EINVAL;
1966}
1967
1968/**
1969 * pci_set_pcie_reset_state - set reset state for device dev
1970 * @dev: the PCIe device reset
1971 * @state: Reset state to enter into
1972 *
1973 * Sets the PCI reset state for the device.
1974 */
1975int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state)
1976{
1977 return pcibios_set_pcie_reset_state(dev, state);
1978}
1979EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state);
1980
1981/**
1982 * pcie_clear_root_pme_status - Clear root port PME interrupt status.
1983 * @dev: PCIe root port or event collector.
1984 */
1985void pcie_clear_root_pme_status(struct pci_dev *dev)
1986{
1987 pcie_capability_set_dword(dev, PCI_EXP_RTSTA, PCI_EXP_RTSTA_PME);
1988}
1989
1990/**
1991 * pci_check_pme_status - Check if given device has generated PME.
1992 * @dev: Device to check.
1993 *
1994 * Check the PME status of the device and if set, clear it and clear PME enable
1995 * (if set). Return 'true' if PME status and PME enable were both set or
1996 * 'false' otherwise.
1997 */
1998bool pci_check_pme_status(struct pci_dev *dev)
1999{
2000 int pmcsr_pos;
2001 u16 pmcsr;
2002 bool ret = false;
2003
2004 if (!dev->pm_cap)
2005 return false;
2006
2007 pmcsr_pos = dev->pm_cap + PCI_PM_CTRL;
2008 pci_read_config_word(dev, pmcsr_pos, &pmcsr);
2009 if (!(pmcsr & PCI_PM_CTRL_PME_STATUS))
2010 return false;
2011
2012 /* Clear PME status. */
2013 pmcsr |= PCI_PM_CTRL_PME_STATUS;
2014 if (pmcsr & PCI_PM_CTRL_PME_ENABLE) {
2015 /* Disable PME to avoid interrupt flood. */
2016 pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
2017 ret = true;
2018 }
2019
2020 pci_write_config_word(dev, pmcsr_pos, pmcsr);
2021
2022 return ret;
2023}
2024
2025/**
2026 * pci_pme_wakeup - Wake up a PCI device if its PME Status bit is set.
2027 * @dev: Device to handle.
2028 * @pme_poll_reset: Whether or not to reset the device's pme_poll flag.
2029 *
2030 * Check if @dev has generated PME and queue a resume request for it in that
2031 * case.
2032 */
2033static int pci_pme_wakeup(struct pci_dev *dev, void *pme_poll_reset)
2034{
2035 if (pme_poll_reset && dev->pme_poll)
2036 dev->pme_poll = false;
2037
2038 if (pci_check_pme_status(dev)) {
2039 pci_wakeup_event(dev);
2040 pm_request_resume(&dev->dev);
2041 }
2042 return 0;
2043}
2044
2045/**
2046 * pci_pme_wakeup_bus - Walk given bus and wake up devices on it, if necessary.
2047 * @bus: Top bus of the subtree to walk.
2048 */
2049void pci_pme_wakeup_bus(struct pci_bus *bus)
2050{
2051 if (bus)
2052 pci_walk_bus(bus, pci_pme_wakeup, (void *)true);
2053}
2054
2055
2056/**
2057 * pci_pme_capable - check the capability of PCI device to generate PME#
2058 * @dev: PCI device to handle.
2059 * @state: PCI state from which device will issue PME#.
2060 */
2061bool pci_pme_capable(struct pci_dev *dev, pci_power_t state)
2062{
2063 if (!dev->pm_cap)
2064 return false;
2065
2066 return !!(dev->pme_support & (1 << state));
2067}
2068EXPORT_SYMBOL(pci_pme_capable);
2069
2070static void pci_pme_list_scan(struct work_struct *work)
2071{
2072 struct pci_pme_device *pme_dev, *n;
2073
2074 mutex_lock(&pci_pme_list_mutex);
2075 list_for_each_entry_safe(pme_dev, n, &pci_pme_list, list) {
2076 if (pme_dev->dev->pme_poll) {
2077 struct pci_dev *bridge;
2078
2079 bridge = pme_dev->dev->bus->self;
2080 /*
2081 * If bridge is in low power state, the
2082 * configuration space of subordinate devices
2083 * may be not accessible
2084 */
2085 if (bridge && bridge->current_state != PCI_D0)
2086 continue;
2087 /*
2088 * If the device is in D3cold it should not be
2089 * polled either.
2090 */
2091 if (pme_dev->dev->current_state == PCI_D3cold)
2092 continue;
2093
2094 pci_pme_wakeup(pme_dev->dev, NULL);
2095 } else {
2096 list_del(&pme_dev->list);
2097 kfree(pme_dev);
2098 }
2099 }
2100 if (!list_empty(&pci_pme_list))
2101 queue_delayed_work(system_freezable_wq, &pci_pme_work,
2102 msecs_to_jiffies(PME_TIMEOUT));
2103 mutex_unlock(&pci_pme_list_mutex);
2104}
2105
2106static void __pci_pme_active(struct pci_dev *dev, bool enable)
2107{
2108 u16 pmcsr;
2109
2110 if (!dev->pme_support)
2111 return;
2112
2113 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
2114 /* Clear PME_Status by writing 1 to it and enable PME# */
2115 pmcsr |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE;
2116 if (!enable)
2117 pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
2118
2119 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
2120}
2121
2122/**
2123 * pci_pme_restore - Restore PME configuration after config space restore.
2124 * @dev: PCI device to update.
2125 */
2126void pci_pme_restore(struct pci_dev *dev)
2127{
2128 u16 pmcsr;
2129
2130 if (!dev->pme_support)
2131 return;
2132
2133 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
2134 if (dev->wakeup_prepared) {
2135 pmcsr |= PCI_PM_CTRL_PME_ENABLE;
2136 pmcsr &= ~PCI_PM_CTRL_PME_STATUS;
2137 } else {
2138 pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
2139 pmcsr |= PCI_PM_CTRL_PME_STATUS;
2140 }
2141 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
2142}
2143
2144/**
2145 * pci_pme_active - enable or disable PCI device's PME# function
2146 * @dev: PCI device to handle.
2147 * @enable: 'true' to enable PME# generation; 'false' to disable it.
2148 *
2149 * The caller must verify that the device is capable of generating PME# before
2150 * calling this function with @enable equal to 'true'.
2151 */
2152void pci_pme_active(struct pci_dev *dev, bool enable)
2153{
2154 __pci_pme_active(dev, enable);
2155
2156 /*
2157 * PCI (as opposed to PCIe) PME requires that the device have
2158 * its PME# line hooked up correctly. Not all hardware vendors
2159 * do this, so the PME never gets delivered and the device
2160 * remains asleep. The easiest way around this is to
2161 * periodically walk the list of suspended devices and check
2162 * whether any have their PME flag set. The assumption is that
2163 * we'll wake up often enough anyway that this won't be a huge
2164 * hit, and the power savings from the devices will still be a
2165 * win.
2166 *
2167 * Although PCIe uses in-band PME message instead of PME# line
2168 * to report PME, PME does not work for some PCIe devices in
2169 * reality. For example, there are devices that set their PME
2170 * status bits, but don't really bother to send a PME message;
2171 * there are PCI Express Root Ports that don't bother to
2172 * trigger interrupts when they receive PME messages from the
2173 * devices below. So PME poll is used for PCIe devices too.
2174 */
2175
2176 if (dev->pme_poll) {
2177 struct pci_pme_device *pme_dev;
2178 if (enable) {
2179 pme_dev = kmalloc(sizeof(struct pci_pme_device),
2180 GFP_KERNEL);
2181 if (!pme_dev) {
2182 pci_warn(dev, "can't enable PME#\n");
2183 return;
2184 }
2185 pme_dev->dev = dev;
2186 mutex_lock(&pci_pme_list_mutex);
2187 list_add(&pme_dev->list, &pci_pme_list);
2188 if (list_is_singular(&pci_pme_list))
2189 queue_delayed_work(system_freezable_wq,
2190 &pci_pme_work,
2191 msecs_to_jiffies(PME_TIMEOUT));
2192 mutex_unlock(&pci_pme_list_mutex);
2193 } else {
2194 mutex_lock(&pci_pme_list_mutex);
2195 list_for_each_entry(pme_dev, &pci_pme_list, list) {
2196 if (pme_dev->dev == dev) {
2197 list_del(&pme_dev->list);
2198 kfree(pme_dev);
2199 break;
2200 }
2201 }
2202 mutex_unlock(&pci_pme_list_mutex);
2203 }
2204 }
2205
2206 pci_dbg(dev, "PME# %s\n", enable ? "enabled" : "disabled");
2207}
2208EXPORT_SYMBOL(pci_pme_active);
2209
2210/**
2211 * __pci_enable_wake - enable PCI device as wakeup event source
2212 * @dev: PCI device affected
2213 * @state: PCI state from which device will issue wakeup events
2214 * @enable: True to enable event generation; false to disable
2215 *
2216 * This enables the device as a wakeup event source, or disables it.
2217 * When such events involves platform-specific hooks, those hooks are
2218 * called automatically by this routine.
2219 *
2220 * Devices with legacy power management (no standard PCI PM capabilities)
2221 * always require such platform hooks.
2222 *
2223 * RETURN VALUE:
2224 * 0 is returned on success
2225 * -EINVAL is returned if device is not supposed to wake up the system
2226 * Error code depending on the platform is returned if both the platform and
2227 * the native mechanism fail to enable the generation of wake-up events
2228 */
2229static int __pci_enable_wake(struct pci_dev *dev, pci_power_t state, bool enable)
2230{
2231 int ret = 0;
2232
2233 /*
2234 * Bridges that are not power-manageable directly only signal
2235 * wakeup on behalf of subordinate devices which is set up
2236 * elsewhere, so skip them. However, bridges that are
2237 * power-manageable may signal wakeup for themselves (for example,
2238 * on a hotplug event) and they need to be covered here.
2239 */
2240 if (!pci_power_manageable(dev))
2241 return 0;
2242
2243 /* Don't do the same thing twice in a row for one device. */
2244 if (!!enable == !!dev->wakeup_prepared)
2245 return 0;
2246
2247 /*
2248 * According to "PCI System Architecture" 4th ed. by Tom Shanley & Don
2249 * Anderson we should be doing PME# wake enable followed by ACPI wake
2250 * enable. To disable wake-up we call the platform first, for symmetry.
2251 */
2252
2253 if (enable) {
2254 int error;
2255
2256 if (pci_pme_capable(dev, state))
2257 pci_pme_active(dev, true);
2258 else
2259 ret = 1;
2260 error = platform_pci_set_wakeup(dev, true);
2261 if (ret)
2262 ret = error;
2263 if (!ret)
2264 dev->wakeup_prepared = true;
2265 } else {
2266 platform_pci_set_wakeup(dev, false);
2267 pci_pme_active(dev, false);
2268 dev->wakeup_prepared = false;
2269 }
2270
2271 return ret;
2272}
2273
2274/**
2275 * pci_enable_wake - change wakeup settings for a PCI device
2276 * @pci_dev: Target device
2277 * @state: PCI state from which device will issue wakeup events
2278 * @enable: Whether or not to enable event generation
2279 *
2280 * If @enable is set, check device_may_wakeup() for the device before calling
2281 * __pci_enable_wake() for it.
2282 */
2283int pci_enable_wake(struct pci_dev *pci_dev, pci_power_t state, bool enable)
2284{
2285 if (enable && !device_may_wakeup(&pci_dev->dev))
2286 return -EINVAL;
2287
2288 return __pci_enable_wake(pci_dev, state, enable);
2289}
2290EXPORT_SYMBOL(pci_enable_wake);
2291
2292/**
2293 * pci_wake_from_d3 - enable/disable device to wake up from D3_hot or D3_cold
2294 * @dev: PCI device to prepare
2295 * @enable: True to enable wake-up event generation; false to disable
2296 *
2297 * Many drivers want the device to wake up the system from D3_hot or D3_cold
2298 * and this function allows them to set that up cleanly - pci_enable_wake()
2299 * should not be called twice in a row to enable wake-up due to PCI PM vs ACPI
2300 * ordering constraints.
2301 *
2302 * This function only returns error code if the device is not allowed to wake
2303 * up the system from sleep or it is not capable of generating PME# from both
2304 * D3_hot and D3_cold and the platform is unable to enable wake-up power for it.
2305 */
2306int pci_wake_from_d3(struct pci_dev *dev, bool enable)
2307{
2308 return pci_pme_capable(dev, PCI_D3cold) ?
2309 pci_enable_wake(dev, PCI_D3cold, enable) :
2310 pci_enable_wake(dev, PCI_D3hot, enable);
2311}
2312EXPORT_SYMBOL(pci_wake_from_d3);
2313
2314/**
2315 * pci_target_state - find an appropriate low power state for a given PCI dev
2316 * @dev: PCI device
2317 * @wakeup: Whether or not wakeup functionality will be enabled for the device.
2318 *
2319 * Use underlying platform code to find a supported low power state for @dev.
2320 * If the platform can't manage @dev, return the deepest state from which it
2321 * can generate wake events, based on any available PME info.
2322 */
2323static pci_power_t pci_target_state(struct pci_dev *dev, bool wakeup)
2324{
2325 pci_power_t target_state = PCI_D3hot;
2326
2327 if (platform_pci_power_manageable(dev)) {
2328 /*
2329 * Call the platform to find the target state for the device.
2330 */
2331 pci_power_t state = platform_pci_choose_state(dev);
2332
2333 switch (state) {
2334 case PCI_POWER_ERROR:
2335 case PCI_UNKNOWN:
2336 break;
2337 case PCI_D1:
2338 case PCI_D2:
2339 if (pci_no_d1d2(dev))
2340 break;
2341 /* else, fall through */
2342 default:
2343 target_state = state;
2344 }
2345
2346 return target_state;
2347 }
2348
2349 if (!dev->pm_cap)
2350 target_state = PCI_D0;
2351
2352 /*
2353 * If the device is in D3cold even though it's not power-manageable by
2354 * the platform, it may have been powered down by non-standard means.
2355 * Best to let it slumber.
2356 */
2357 if (dev->current_state == PCI_D3cold)
2358 target_state = PCI_D3cold;
2359
2360 if (wakeup) {
2361 /*
2362 * Find the deepest state from which the device can generate
2363 * PME#.
2364 */
2365 if (dev->pme_support) {
2366 while (target_state
2367 && !(dev->pme_support & (1 << target_state)))
2368 target_state--;
2369 }
2370 }
2371
2372 return target_state;
2373}
2374
2375/**
2376 * pci_prepare_to_sleep - prepare PCI device for system-wide transition
2377 * into a sleep state
2378 * @dev: Device to handle.
2379 *
2380 * Choose the power state appropriate for the device depending on whether
2381 * it can wake up the system and/or is power manageable by the platform
2382 * (PCI_D3hot is the default) and put the device into that state.
2383 */
2384int pci_prepare_to_sleep(struct pci_dev *dev)
2385{
2386 bool wakeup = device_may_wakeup(&dev->dev);
2387 pci_power_t target_state = pci_target_state(dev, wakeup);
2388 int error;
2389
2390 if (target_state == PCI_POWER_ERROR)
2391 return -EIO;
2392
2393 pci_enable_wake(dev, target_state, wakeup);
2394
2395 error = pci_set_power_state(dev, target_state);
2396
2397 if (error)
2398 pci_enable_wake(dev, target_state, false);
2399
2400 return error;
2401}
2402EXPORT_SYMBOL(pci_prepare_to_sleep);
2403
2404/**
2405 * pci_back_from_sleep - turn PCI device on during system-wide transition
2406 * into working state
2407 * @dev: Device to handle.
2408 *
2409 * Disable device's system wake-up capability and put it into D0.
2410 */
2411int pci_back_from_sleep(struct pci_dev *dev)
2412{
2413 pci_enable_wake(dev, PCI_D0, false);
2414 return pci_set_power_state(dev, PCI_D0);
2415}
2416EXPORT_SYMBOL(pci_back_from_sleep);
2417
2418/**
2419 * pci_finish_runtime_suspend - Carry out PCI-specific part of runtime suspend.
2420 * @dev: PCI device being suspended.
2421 *
2422 * Prepare @dev to generate wake-up events at run time and put it into a low
2423 * power state.
2424 */
2425int pci_finish_runtime_suspend(struct pci_dev *dev)
2426{
2427 pci_power_t target_state;
2428 int error;
2429
2430 target_state = pci_target_state(dev, device_can_wakeup(&dev->dev));
2431 if (target_state == PCI_POWER_ERROR)
2432 return -EIO;
2433
2434 dev->runtime_d3cold = target_state == PCI_D3cold;
2435
2436 __pci_enable_wake(dev, target_state, pci_dev_run_wake(dev));
2437
2438 error = pci_set_power_state(dev, target_state);
2439
2440 if (error) {
2441 pci_enable_wake(dev, target_state, false);
2442 dev->runtime_d3cold = false;
2443 }
2444
2445 return error;
2446}
2447
2448/**
2449 * pci_dev_run_wake - Check if device can generate run-time wake-up events.
2450 * @dev: Device to check.
2451 *
2452 * Return true if the device itself is capable of generating wake-up events
2453 * (through the platform or using the native PCIe PME) or if the device supports
2454 * PME and one of its upstream bridges can generate wake-up events.
2455 */
2456bool pci_dev_run_wake(struct pci_dev *dev)
2457{
2458 struct pci_bus *bus = dev->bus;
2459
2460 if (!dev->pme_support)
2461 return false;
2462
2463 /* PME-capable in principle, but not from the target power state */
2464 if (!pci_pme_capable(dev, pci_target_state(dev, true)))
2465 return false;
2466
2467 if (device_can_wakeup(&dev->dev))
2468 return true;
2469
2470 while (bus->parent) {
2471 struct pci_dev *bridge = bus->self;
2472
2473 if (device_can_wakeup(&bridge->dev))
2474 return true;
2475
2476 bus = bus->parent;
2477 }
2478
2479 /* We have reached the root bus. */
2480 if (bus->bridge)
2481 return device_can_wakeup(bus->bridge);
2482
2483 return false;
2484}
2485EXPORT_SYMBOL_GPL(pci_dev_run_wake);
2486
2487/**
2488 * pci_dev_need_resume - Check if it is necessary to resume the device.
2489 * @pci_dev: Device to check.
2490 *
2491 * Return 'true' if the device is not runtime-suspended or it has to be
2492 * reconfigured due to wakeup settings difference between system and runtime
2493 * suspend, or the current power state of it is not suitable for the upcoming
2494 * (system-wide) transition.
2495 */
2496bool pci_dev_need_resume(struct pci_dev *pci_dev)
2497{
2498 struct device *dev = &pci_dev->dev;
2499 pci_power_t target_state;
2500
2501 if (!pm_runtime_suspended(dev) || platform_pci_need_resume(pci_dev))
2502 return true;
2503
2504 target_state = pci_target_state(pci_dev, device_may_wakeup(dev));
2505
2506 /*
2507 * If the earlier platform check has not triggered, D3cold is just power
2508 * removal on top of D3hot, so no need to resume the device in that
2509 * case.
2510 */
2511 return target_state != pci_dev->current_state &&
2512 target_state != PCI_D3cold &&
2513 pci_dev->current_state != PCI_D3hot;
2514}
2515
2516/**
2517 * pci_dev_adjust_pme - Adjust PME setting for a suspended device.
2518 * @pci_dev: Device to check.
2519 *
2520 * If the device is suspended and it is not configured for system wakeup,
2521 * disable PME for it to prevent it from waking up the system unnecessarily.
2522 *
2523 * Note that if the device's power state is D3cold and the platform check in
2524 * pci_dev_need_resume() has not triggered, the device's configuration need not
2525 * be changed.
2526 */
2527void pci_dev_adjust_pme(struct pci_dev *pci_dev)
2528{
2529 struct device *dev = &pci_dev->dev;
2530
2531 spin_lock_irq(&dev->power.lock);
2532
2533 if (pm_runtime_suspended(dev) && !device_may_wakeup(dev) &&
2534 pci_dev->current_state < PCI_D3cold)
2535 __pci_pme_active(pci_dev, false);
2536
2537 spin_unlock_irq(&dev->power.lock);
2538}
2539
2540/**
2541 * pci_dev_complete_resume - Finalize resume from system sleep for a device.
2542 * @pci_dev: Device to handle.
2543 *
2544 * If the device is runtime suspended and wakeup-capable, enable PME for it as
2545 * it might have been disabled during the prepare phase of system suspend if
2546 * the device was not configured for system wakeup.
2547 */
2548void pci_dev_complete_resume(struct pci_dev *pci_dev)
2549{
2550 struct device *dev = &pci_dev->dev;
2551
2552 if (!pci_dev_run_wake(pci_dev))
2553 return;
2554
2555 spin_lock_irq(&dev->power.lock);
2556
2557 if (pm_runtime_suspended(dev) && pci_dev->current_state < PCI_D3cold)
2558 __pci_pme_active(pci_dev, true);
2559
2560 spin_unlock_irq(&dev->power.lock);
2561}
2562
2563void pci_config_pm_runtime_get(struct pci_dev *pdev)
2564{
2565 struct device *dev = &pdev->dev;
2566 struct device *parent = dev->parent;
2567
2568 if (parent)
2569 pm_runtime_get_sync(parent);
2570 pm_runtime_get_noresume(dev);
2571 /*
2572 * pdev->current_state is set to PCI_D3cold during suspending,
2573 * so wait until suspending completes
2574 */
2575 pm_runtime_barrier(dev);
2576 /*
2577 * Only need to resume devices in D3cold, because config
2578 * registers are still accessible for devices suspended but
2579 * not in D3cold.
2580 */
2581 if (pdev->current_state == PCI_D3cold)
2582 pm_runtime_resume(dev);
2583}
2584
2585void pci_config_pm_runtime_put(struct pci_dev *pdev)
2586{
2587 struct device *dev = &pdev->dev;
2588 struct device *parent = dev->parent;
2589
2590 pm_runtime_put(dev);
2591 if (parent)
2592 pm_runtime_put_sync(parent);
2593}
2594
2595static const struct dmi_system_id bridge_d3_blacklist[] = {
2596#ifdef CONFIG_X86
2597 {
2598 /*
2599 * Gigabyte X299 root port is not marked as hotplug capable
2600 * which allows Linux to power manage it. However, this
2601 * confuses the BIOS SMI handler so don't power manage root
2602 * ports on that system.
2603 */
2604 .ident = "X299 DESIGNARE EX-CF",
2605 .matches = {
2606 DMI_MATCH(DMI_BOARD_VENDOR, "Gigabyte Technology Co., Ltd."),
2607 DMI_MATCH(DMI_BOARD_NAME, "X299 DESIGNARE EX-CF"),
2608 },
2609 },
2610#endif
2611 { }
2612};
2613
2614/**
2615 * pci_bridge_d3_possible - Is it possible to put the bridge into D3
2616 * @bridge: Bridge to check
2617 *
2618 * This function checks if it is possible to move the bridge to D3.
2619 * Currently we only allow D3 for recent enough PCIe ports and Thunderbolt.
2620 */
2621bool pci_bridge_d3_possible(struct pci_dev *bridge)
2622{
2623 if (!pci_is_pcie(bridge))
2624 return false;
2625
2626 switch (pci_pcie_type(bridge)) {
2627 case PCI_EXP_TYPE_ROOT_PORT:
2628 case PCI_EXP_TYPE_UPSTREAM:
2629 case PCI_EXP_TYPE_DOWNSTREAM:
2630 if (pci_bridge_d3_disable)
2631 return false;
2632
2633 /*
2634 * Hotplug ports handled by firmware in System Management Mode
2635 * may not be put into D3 by the OS (Thunderbolt on non-Macs).
2636 */
2637 if (bridge->is_hotplug_bridge && !pciehp_is_native(bridge))
2638 return false;
2639
2640 if (pci_bridge_d3_force)
2641 return true;
2642
2643 /* Even the oldest 2010 Thunderbolt controller supports D3. */
2644 if (bridge->is_thunderbolt)
2645 return true;
2646
2647 /* Platform might know better if the bridge supports D3 */
2648 if (platform_pci_bridge_d3(bridge))
2649 return true;
2650
2651 /*
2652 * Hotplug ports handled natively by the OS were not validated
2653 * by vendors for runtime D3 at least until 2018 because there
2654 * was no OS support.
2655 */
2656 if (bridge->is_hotplug_bridge)
2657 return false;
2658
2659 if (dmi_check_system(bridge_d3_blacklist))
2660 return false;
2661
2662 /*
2663 * It should be safe to put PCIe ports from 2015 or newer
2664 * to D3.
2665 */
2666 if (dmi_get_bios_year() >= 2015)
2667 return true;
2668 break;
2669 }
2670
2671 return false;
2672}
2673
2674static int pci_dev_check_d3cold(struct pci_dev *dev, void *data)
2675{
2676 bool *d3cold_ok = data;
2677
2678 if (/* The device needs to be allowed to go D3cold ... */
2679 dev->no_d3cold || !dev->d3cold_allowed ||
2680
2681 /* ... and if it is wakeup capable to do so from D3cold. */
2682 (device_may_wakeup(&dev->dev) &&
2683 !pci_pme_capable(dev, PCI_D3cold)) ||
2684
2685 /* If it is a bridge it must be allowed to go to D3. */
2686 !pci_power_manageable(dev))
2687
2688 *d3cold_ok = false;
2689
2690 return !*d3cold_ok;
2691}
2692
2693/*
2694 * pci_bridge_d3_update - Update bridge D3 capabilities
2695 * @dev: PCI device which is changed
2696 *
2697 * Update upstream bridge PM capabilities accordingly depending on if the
2698 * device PM configuration was changed or the device is being removed. The
2699 * change is also propagated upstream.
2700 */
2701void pci_bridge_d3_update(struct pci_dev *dev)
2702{
2703 bool remove = !device_is_registered(&dev->dev);
2704 struct pci_dev *bridge;
2705 bool d3cold_ok = true;
2706
2707 bridge = pci_upstream_bridge(dev);
2708 if (!bridge || !pci_bridge_d3_possible(bridge))
2709 return;
2710
2711 /*
2712 * If D3 is currently allowed for the bridge, removing one of its
2713 * children won't change that.
2714 */
2715 if (remove && bridge->bridge_d3)
2716 return;
2717
2718 /*
2719 * If D3 is currently allowed for the bridge and a child is added or
2720 * changed, disallowance of D3 can only be caused by that child, so
2721 * we only need to check that single device, not any of its siblings.
2722 *
2723 * If D3 is currently not allowed for the bridge, checking the device
2724 * first may allow us to skip checking its siblings.
2725 */
2726 if (!remove)
2727 pci_dev_check_d3cold(dev, &d3cold_ok);
2728
2729 /*
2730 * If D3 is currently not allowed for the bridge, this may be caused
2731 * either by the device being changed/removed or any of its siblings,
2732 * so we need to go through all children to find out if one of them
2733 * continues to block D3.
2734 */
2735 if (d3cold_ok && !bridge->bridge_d3)
2736 pci_walk_bus(bridge->subordinate, pci_dev_check_d3cold,
2737 &d3cold_ok);
2738
2739 if (bridge->bridge_d3 != d3cold_ok) {
2740 bridge->bridge_d3 = d3cold_ok;
2741 /* Propagate change to upstream bridges */
2742 pci_bridge_d3_update(bridge);
2743 }
2744}
2745
2746/**
2747 * pci_d3cold_enable - Enable D3cold for device
2748 * @dev: PCI device to handle
2749 *
2750 * This function can be used in drivers to enable D3cold from the device
2751 * they handle. It also updates upstream PCI bridge PM capabilities
2752 * accordingly.
2753 */
2754void pci_d3cold_enable(struct pci_dev *dev)
2755{
2756 if (dev->no_d3cold) {
2757 dev->no_d3cold = false;
2758 pci_bridge_d3_update(dev);
2759 }
2760}
2761EXPORT_SYMBOL_GPL(pci_d3cold_enable);
2762
2763/**
2764 * pci_d3cold_disable - Disable D3cold for device
2765 * @dev: PCI device to handle
2766 *
2767 * This function can be used in drivers to disable D3cold from the device
2768 * they handle. It also updates upstream PCI bridge PM capabilities
2769 * accordingly.
2770 */
2771void pci_d3cold_disable(struct pci_dev *dev)
2772{
2773 if (!dev->no_d3cold) {
2774 dev->no_d3cold = true;
2775 pci_bridge_d3_update(dev);
2776 }
2777}
2778EXPORT_SYMBOL_GPL(pci_d3cold_disable);
2779
2780/**
2781 * pci_pm_init - Initialize PM functions of given PCI device
2782 * @dev: PCI device to handle.
2783 */
2784void pci_pm_init(struct pci_dev *dev)
2785{
2786 int pm;
2787 u16 status;
2788 u16 pmc;
2789
2790 pm_runtime_forbid(&dev->dev);
2791 pm_runtime_set_active(&dev->dev);
2792 pm_runtime_enable(&dev->dev);
2793 device_enable_async_suspend(&dev->dev);
2794 dev->wakeup_prepared = false;
2795
2796 dev->pm_cap = 0;
2797 dev->pme_support = 0;
2798
2799 /* find PCI PM capability in list */
2800 pm = pci_find_capability(dev, PCI_CAP_ID_PM);
2801 if (!pm)
2802 return;
2803 /* Check device's ability to generate PME# */
2804 pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
2805
2806 if ((pmc & PCI_PM_CAP_VER_MASK) > 3) {
2807 pci_err(dev, "unsupported PM cap regs version (%u)\n",
2808 pmc & PCI_PM_CAP_VER_MASK);
2809 return;
2810 }
2811
2812 dev->pm_cap = pm;
2813 dev->d3_delay = PCI_PM_D3_WAIT;
2814 dev->d3cold_delay = PCI_PM_D3COLD_WAIT;
2815 dev->bridge_d3 = pci_bridge_d3_possible(dev);
2816 dev->d3cold_allowed = true;
2817
2818 dev->d1_support = false;
2819 dev->d2_support = false;
2820 if (!pci_no_d1d2(dev)) {
2821 if (pmc & PCI_PM_CAP_D1)
2822 dev->d1_support = true;
2823 if (pmc & PCI_PM_CAP_D2)
2824 dev->d2_support = true;
2825
2826 if (dev->d1_support || dev->d2_support)
2827 pci_info(dev, "supports%s%s\n",
2828 dev->d1_support ? " D1" : "",
2829 dev->d2_support ? " D2" : "");
2830 }
2831
2832 pmc &= PCI_PM_CAP_PME_MASK;
2833 if (pmc) {
2834 pci_info(dev, "PME# supported from%s%s%s%s%s\n",
2835 (pmc & PCI_PM_CAP_PME_D0) ? " D0" : "",
2836 (pmc & PCI_PM_CAP_PME_D1) ? " D1" : "",
2837 (pmc & PCI_PM_CAP_PME_D2) ? " D2" : "",
2838 (pmc & PCI_PM_CAP_PME_D3) ? " D3hot" : "",
2839 (pmc & PCI_PM_CAP_PME_D3cold) ? " D3cold" : "");
2840 dev->pme_support = pmc >> PCI_PM_CAP_PME_SHIFT;
2841 dev->pme_poll = true;
2842 /*
2843 * Make device's PM flags reflect the wake-up capability, but
2844 * let the user space enable it to wake up the system as needed.
2845 */
2846 device_set_wakeup_capable(&dev->dev, true);
2847 /* Disable the PME# generation functionality */
2848 pci_pme_active(dev, false);
2849 }
2850
2851 pci_read_config_word(dev, PCI_STATUS, &status);
2852 if (status & PCI_STATUS_IMM_READY)
2853 dev->imm_ready = 1;
2854}
2855
2856static unsigned long pci_ea_flags(struct pci_dev *dev, u8 prop)
2857{
2858 unsigned long flags = IORESOURCE_PCI_FIXED | IORESOURCE_PCI_EA_BEI;
2859
2860 switch (prop) {
2861 case PCI_EA_P_MEM:
2862 case PCI_EA_P_VF_MEM:
2863 flags |= IORESOURCE_MEM;
2864 break;
2865 case PCI_EA_P_MEM_PREFETCH:
2866 case PCI_EA_P_VF_MEM_PREFETCH:
2867 flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH;
2868 break;
2869 case PCI_EA_P_IO:
2870 flags |= IORESOURCE_IO;
2871 break;
2872 default:
2873 return 0;
2874 }
2875
2876 return flags;
2877}
2878
2879static struct resource *pci_ea_get_resource(struct pci_dev *dev, u8 bei,
2880 u8 prop)
2881{
2882 if (bei <= PCI_EA_BEI_BAR5 && prop <= PCI_EA_P_IO)
2883 return &dev->resource[bei];
2884#ifdef CONFIG_PCI_IOV
2885 else if (bei >= PCI_EA_BEI_VF_BAR0 && bei <= PCI_EA_BEI_VF_BAR5 &&
2886 (prop == PCI_EA_P_VF_MEM || prop == PCI_EA_P_VF_MEM_PREFETCH))
2887 return &dev->resource[PCI_IOV_RESOURCES +
2888 bei - PCI_EA_BEI_VF_BAR0];
2889#endif
2890 else if (bei == PCI_EA_BEI_ROM)
2891 return &dev->resource[PCI_ROM_RESOURCE];
2892 else
2893 return NULL;
2894}
2895
2896/* Read an Enhanced Allocation (EA) entry */
2897static int pci_ea_read(struct pci_dev *dev, int offset)
2898{
2899 struct resource *res;
2900 int ent_size, ent_offset = offset;
2901 resource_size_t start, end;
2902 unsigned long flags;
2903 u32 dw0, bei, base, max_offset;
2904 u8 prop;
2905 bool support_64 = (sizeof(resource_size_t) >= 8);
2906
2907 pci_read_config_dword(dev, ent_offset, &dw0);
2908 ent_offset += 4;
2909
2910 /* Entry size field indicates DWORDs after 1st */
2911 ent_size = ((dw0 & PCI_EA_ES) + 1) << 2;
2912
2913 if (!(dw0 & PCI_EA_ENABLE)) /* Entry not enabled */
2914 goto out;
2915
2916 bei = (dw0 & PCI_EA_BEI) >> 4;
2917 prop = (dw0 & PCI_EA_PP) >> 8;
2918
2919 /*
2920 * If the Property is in the reserved range, try the Secondary
2921 * Property instead.
2922 */
2923 if (prop > PCI_EA_P_BRIDGE_IO && prop < PCI_EA_P_MEM_RESERVED)
2924 prop = (dw0 & PCI_EA_SP) >> 16;
2925 if (prop > PCI_EA_P_BRIDGE_IO)
2926 goto out;
2927
2928 res = pci_ea_get_resource(dev, bei, prop);
2929 if (!res) {
2930 pci_err(dev, "Unsupported EA entry BEI: %u\n", bei);
2931 goto out;
2932 }
2933
2934 flags = pci_ea_flags(dev, prop);
2935 if (!flags) {
2936 pci_err(dev, "Unsupported EA properties: %#x\n", prop);
2937 goto out;
2938 }
2939
2940 /* Read Base */
2941 pci_read_config_dword(dev, ent_offset, &base);
2942 start = (base & PCI_EA_FIELD_MASK);
2943 ent_offset += 4;
2944
2945 /* Read MaxOffset */
2946 pci_read_config_dword(dev, ent_offset, &max_offset);
2947 ent_offset += 4;
2948
2949 /* Read Base MSBs (if 64-bit entry) */
2950 if (base & PCI_EA_IS_64) {
2951 u32 base_upper;
2952
2953 pci_read_config_dword(dev, ent_offset, &base_upper);
2954 ent_offset += 4;
2955
2956 flags |= IORESOURCE_MEM_64;
2957
2958 /* entry starts above 32-bit boundary, can't use */
2959 if (!support_64 && base_upper)
2960 goto out;
2961
2962 if (support_64)
2963 start |= ((u64)base_upper << 32);
2964 }
2965
2966 end = start + (max_offset | 0x03);
2967
2968 /* Read MaxOffset MSBs (if 64-bit entry) */
2969 if (max_offset & PCI_EA_IS_64) {
2970 u32 max_offset_upper;
2971
2972 pci_read_config_dword(dev, ent_offset, &max_offset_upper);
2973 ent_offset += 4;
2974
2975 flags |= IORESOURCE_MEM_64;
2976
2977 /* entry too big, can't use */
2978 if (!support_64 && max_offset_upper)
2979 goto out;
2980
2981 if (support_64)
2982 end += ((u64)max_offset_upper << 32);
2983 }
2984
2985 if (end < start) {
2986 pci_err(dev, "EA Entry crosses address boundary\n");
2987 goto out;
2988 }
2989
2990 if (ent_size != ent_offset - offset) {
2991 pci_err(dev, "EA Entry Size (%d) does not match length read (%d)\n",
2992 ent_size, ent_offset - offset);
2993 goto out;
2994 }
2995
2996 res->name = pci_name(dev);
2997 res->start = start;
2998 res->end = end;
2999 res->flags = flags;
3000
3001 if (bei <= PCI_EA_BEI_BAR5)
3002 pci_info(dev, "BAR %d: %pR (from Enhanced Allocation, properties %#02x)\n",
3003 bei, res, prop);
3004 else if (bei == PCI_EA_BEI_ROM)
3005 pci_info(dev, "ROM: %pR (from Enhanced Allocation, properties %#02x)\n",
3006 res, prop);
3007 else if (bei >= PCI_EA_BEI_VF_BAR0 && bei <= PCI_EA_BEI_VF_BAR5)
3008 pci_info(dev, "VF BAR %d: %pR (from Enhanced Allocation, properties %#02x)\n",
3009 bei - PCI_EA_BEI_VF_BAR0, res, prop);
3010 else
3011 pci_info(dev, "BEI %d res: %pR (from Enhanced Allocation, properties %#02x)\n",
3012 bei, res, prop);
3013
3014out:
3015 return offset + ent_size;
3016}
3017
3018/* Enhanced Allocation Initialization */
3019void pci_ea_init(struct pci_dev *dev)
3020{
3021 int ea;
3022 u8 num_ent;
3023 int offset;
3024 int i;
3025
3026 /* find PCI EA capability in list */
3027 ea = pci_find_capability(dev, PCI_CAP_ID_EA);
3028 if (!ea)
3029 return;
3030
3031 /* determine the number of entries */
3032 pci_bus_read_config_byte(dev->bus, dev->devfn, ea + PCI_EA_NUM_ENT,
3033 &num_ent);
3034 num_ent &= PCI_EA_NUM_ENT_MASK;
3035
3036 offset = ea + PCI_EA_FIRST_ENT;
3037
3038 /* Skip DWORD 2 for type 1 functions */
3039 if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)
3040 offset += 4;
3041
3042 /* parse each EA entry */
3043 for (i = 0; i < num_ent; ++i)
3044 offset = pci_ea_read(dev, offset);
3045}
3046
3047static void pci_add_saved_cap(struct pci_dev *pci_dev,
3048 struct pci_cap_saved_state *new_cap)
3049{
3050 hlist_add_head(&new_cap->next, &pci_dev->saved_cap_space);
3051}
3052
3053/**
3054 * _pci_add_cap_save_buffer - allocate buffer for saving given
3055 * capability registers
3056 * @dev: the PCI device
3057 * @cap: the capability to allocate the buffer for
3058 * @extended: Standard or Extended capability ID
3059 * @size: requested size of the buffer
3060 */
3061static int _pci_add_cap_save_buffer(struct pci_dev *dev, u16 cap,
3062 bool extended, unsigned int size)
3063{
3064 int pos;
3065 struct pci_cap_saved_state *save_state;
3066
3067 if (extended)
3068 pos = pci_find_ext_capability(dev, cap);
3069 else
3070 pos = pci_find_capability(dev, cap);
3071
3072 if (!pos)
3073 return 0;
3074
3075 save_state = kzalloc(sizeof(*save_state) + size, GFP_KERNEL);
3076 if (!save_state)
3077 return -ENOMEM;
3078
3079 save_state->cap.cap_nr = cap;
3080 save_state->cap.cap_extended = extended;
3081 save_state->cap.size = size;
3082 pci_add_saved_cap(dev, save_state);
3083
3084 return 0;
3085}
3086
3087int pci_add_cap_save_buffer(struct pci_dev *dev, char cap, unsigned int size)
3088{
3089 return _pci_add_cap_save_buffer(dev, cap, false, size);
3090}
3091
3092int pci_add_ext_cap_save_buffer(struct pci_dev *dev, u16 cap, unsigned int size)
3093{
3094 return _pci_add_cap_save_buffer(dev, cap, true, size);
3095}
3096
3097/**
3098 * pci_allocate_cap_save_buffers - allocate buffers for saving capabilities
3099 * @dev: the PCI device
3100 */
3101void pci_allocate_cap_save_buffers(struct pci_dev *dev)
3102{
3103 int error;
3104
3105 error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_EXP,
3106 PCI_EXP_SAVE_REGS * sizeof(u16));
3107 if (error)
3108 pci_err(dev, "unable to preallocate PCI Express save buffer\n");
3109
3110 error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_PCIX, sizeof(u16));
3111 if (error)
3112 pci_err(dev, "unable to preallocate PCI-X save buffer\n");
3113
3114 error = pci_add_ext_cap_save_buffer(dev, PCI_EXT_CAP_ID_LTR,
3115 2 * sizeof(u16));
3116 if (error)
3117 pci_err(dev, "unable to allocate suspend buffer for LTR\n");
3118
3119 pci_allocate_vc_save_buffers(dev);
3120}
3121
3122void pci_free_cap_save_buffers(struct pci_dev *dev)
3123{
3124 struct pci_cap_saved_state *tmp;
3125 struct hlist_node *n;
3126
3127 hlist_for_each_entry_safe(tmp, n, &dev->saved_cap_space, next)
3128 kfree(tmp);
3129}
3130
3131/**
3132 * pci_configure_ari - enable or disable ARI forwarding
3133 * @dev: the PCI device
3134 *
3135 * If @dev and its upstream bridge both support ARI, enable ARI in the
3136 * bridge. Otherwise, disable ARI in the bridge.
3137 */
3138void pci_configure_ari(struct pci_dev *dev)
3139{
3140 u32 cap;
3141 struct pci_dev *bridge;
3142
3143 if (pcie_ari_disabled || !pci_is_pcie(dev) || dev->devfn)
3144 return;
3145
3146 bridge = dev->bus->self;
3147 if (!bridge)
3148 return;
3149
3150 pcie_capability_read_dword(bridge, PCI_EXP_DEVCAP2, &cap);
3151 if (!(cap & PCI_EXP_DEVCAP2_ARI))
3152 return;
3153
3154 if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI)) {
3155 pcie_capability_set_word(bridge, PCI_EXP_DEVCTL2,
3156 PCI_EXP_DEVCTL2_ARI);
3157 bridge->ari_enabled = 1;
3158 } else {
3159 pcie_capability_clear_word(bridge, PCI_EXP_DEVCTL2,
3160 PCI_EXP_DEVCTL2_ARI);
3161 bridge->ari_enabled = 0;
3162 }
3163}
3164
3165static int pci_acs_enable;
3166
3167/**
3168 * pci_request_acs - ask for ACS to be enabled if supported
3169 */
3170void pci_request_acs(void)
3171{
3172 pci_acs_enable = 1;
3173}
3174
3175static const char *disable_acs_redir_param;
3176
3177/**
3178 * pci_disable_acs_redir - disable ACS redirect capabilities
3179 * @dev: the PCI device
3180 *
3181 * For only devices specified in the disable_acs_redir parameter.
3182 */
3183static void pci_disable_acs_redir(struct pci_dev *dev)
3184{
3185 int ret = 0;
3186 const char *p;
3187 int pos;
3188 u16 ctrl;
3189
3190 if (!disable_acs_redir_param)
3191 return;
3192
3193 p = disable_acs_redir_param;
3194 while (*p) {
3195 ret = pci_dev_str_match(dev, p, &p);
3196 if (ret < 0) {
3197 pr_info_once("PCI: Can't parse disable_acs_redir parameter: %s\n",
3198 disable_acs_redir_param);
3199
3200 break;
3201 } else if (ret == 1) {
3202 /* Found a match */
3203 break;
3204 }
3205
3206 if (*p != ';' && *p != ',') {
3207 /* End of param or invalid format */
3208 break;
3209 }
3210 p++;
3211 }
3212
3213 if (ret != 1)
3214 return;
3215
3216 if (!pci_dev_specific_disable_acs_redir(dev))
3217 return;
3218
3219 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS);
3220 if (!pos) {
3221 pci_warn(dev, "cannot disable ACS redirect for this hardware as it does not have ACS capabilities\n");
3222 return;
3223 }
3224
3225 pci_read_config_word(dev, pos + PCI_ACS_CTRL, &ctrl);
3226
3227 /* P2P Request & Completion Redirect */
3228 ctrl &= ~(PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_EC);
3229
3230 pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl);
3231
3232 pci_info(dev, "disabled ACS redirect\n");
3233}
3234
3235/**
3236 * pci_std_enable_acs - enable ACS on devices using standard ACS capabilities
3237 * @dev: the PCI device
3238 */
3239static void pci_std_enable_acs(struct pci_dev *dev)
3240{
3241 int pos;
3242 u16 cap;
3243 u16 ctrl;
3244
3245 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS);
3246 if (!pos)
3247 return;
3248
3249 pci_read_config_word(dev, pos + PCI_ACS_CAP, &cap);
3250 pci_read_config_word(dev, pos + PCI_ACS_CTRL, &ctrl);
3251
3252 /* Source Validation */
3253 ctrl |= (cap & PCI_ACS_SV);
3254
3255 /* P2P Request Redirect */
3256 ctrl |= (cap & PCI_ACS_RR);
3257
3258 /* P2P Completion Redirect */
3259 ctrl |= (cap & PCI_ACS_CR);
3260
3261 /* Upstream Forwarding */
3262 ctrl |= (cap & PCI_ACS_UF);
3263
3264 pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl);
3265}
3266
3267/**
3268 * pci_enable_acs - enable ACS if hardware support it
3269 * @dev: the PCI device
3270 */
3271void pci_enable_acs(struct pci_dev *dev)
3272{
3273 if (!pci_acs_enable)
3274 goto disable_acs_redir;
3275
3276 if (!pci_dev_specific_enable_acs(dev))
3277 goto disable_acs_redir;
3278
3279 pci_std_enable_acs(dev);
3280
3281disable_acs_redir:
3282 /*
3283 * Note: pci_disable_acs_redir() must be called even if ACS was not
3284 * enabled by the kernel because it may have been enabled by
3285 * platform firmware. So if we are told to disable it, we should
3286 * always disable it after setting the kernel's default
3287 * preferences.
3288 */
3289 pci_disable_acs_redir(dev);
3290}
3291
3292static bool pci_acs_flags_enabled(struct pci_dev *pdev, u16 acs_flags)
3293{
3294 int pos;
3295 u16 cap, ctrl;
3296
3297 pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ACS);
3298 if (!pos)
3299 return false;
3300
3301 /*
3302 * Except for egress control, capabilities are either required
3303 * or only required if controllable. Features missing from the
3304 * capability field can therefore be assumed as hard-wired enabled.
3305 */
3306 pci_read_config_word(pdev, pos + PCI_ACS_CAP, &cap);
3307 acs_flags &= (cap | PCI_ACS_EC);
3308
3309 pci_read_config_word(pdev, pos + PCI_ACS_CTRL, &ctrl);
3310 return (ctrl & acs_flags) == acs_flags;
3311}
3312
3313/**
3314 * pci_acs_enabled - test ACS against required flags for a given device
3315 * @pdev: device to test
3316 * @acs_flags: required PCI ACS flags
3317 *
3318 * Return true if the device supports the provided flags. Automatically
3319 * filters out flags that are not implemented on multifunction devices.
3320 *
3321 * Note that this interface checks the effective ACS capabilities of the
3322 * device rather than the actual capabilities. For instance, most single
3323 * function endpoints are not required to support ACS because they have no
3324 * opportunity for peer-to-peer access. We therefore return 'true'
3325 * regardless of whether the device exposes an ACS capability. This makes
3326 * it much easier for callers of this function to ignore the actual type
3327 * or topology of the device when testing ACS support.
3328 */
3329bool pci_acs_enabled(struct pci_dev *pdev, u16 acs_flags)
3330{
3331 int ret;
3332
3333 ret = pci_dev_specific_acs_enabled(pdev, acs_flags);
3334 if (ret >= 0)
3335 return ret > 0;
3336
3337 /*
3338 * Conventional PCI and PCI-X devices never support ACS, either
3339 * effectively or actually. The shared bus topology implies that
3340 * any device on the bus can receive or snoop DMA.
3341 */
3342 if (!pci_is_pcie(pdev))
3343 return false;
3344
3345 switch (pci_pcie_type(pdev)) {
3346 /*
3347 * PCI/X-to-PCIe bridges are not specifically mentioned by the spec,
3348 * but since their primary interface is PCI/X, we conservatively
3349 * handle them as we would a non-PCIe device.
3350 */
3351 case PCI_EXP_TYPE_PCIE_BRIDGE:
3352 /*
3353 * PCIe 3.0, 6.12.1 excludes ACS on these devices. "ACS is never
3354 * applicable... must never implement an ACS Extended Capability...".
3355 * This seems arbitrary, but we take a conservative interpretation
3356 * of this statement.
3357 */
3358 case PCI_EXP_TYPE_PCI_BRIDGE:
3359 case PCI_EXP_TYPE_RC_EC:
3360 return false;
3361 /*
3362 * PCIe 3.0, 6.12.1.1 specifies that downstream and root ports should
3363 * implement ACS in order to indicate their peer-to-peer capabilities,
3364 * regardless of whether they are single- or multi-function devices.
3365 */
3366 case PCI_EXP_TYPE_DOWNSTREAM:
3367 case PCI_EXP_TYPE_ROOT_PORT:
3368 return pci_acs_flags_enabled(pdev, acs_flags);
3369 /*
3370 * PCIe 3.0, 6.12.1.2 specifies ACS capabilities that should be
3371 * implemented by the remaining PCIe types to indicate peer-to-peer
3372 * capabilities, but only when they are part of a multifunction
3373 * device. The footnote for section 6.12 indicates the specific
3374 * PCIe types included here.
3375 */
3376 case PCI_EXP_TYPE_ENDPOINT:
3377 case PCI_EXP_TYPE_UPSTREAM:
3378 case PCI_EXP_TYPE_LEG_END:
3379 case PCI_EXP_TYPE_RC_END:
3380 if (!pdev->multifunction)
3381 break;
3382
3383 return pci_acs_flags_enabled(pdev, acs_flags);
3384 }
3385
3386 /*
3387 * PCIe 3.0, 6.12.1.3 specifies no ACS capabilities are applicable
3388 * to single function devices with the exception of downstream ports.
3389 */
3390 return true;
3391}
3392
3393/**
3394 * pci_acs_path_enable - test ACS flags from start to end in a hierarchy
3395 * @start: starting downstream device
3396 * @end: ending upstream device or NULL to search to the root bus
3397 * @acs_flags: required flags
3398 *
3399 * Walk up a device tree from start to end testing PCI ACS support. If
3400 * any step along the way does not support the required flags, return false.
3401 */
3402bool pci_acs_path_enabled(struct pci_dev *start,
3403 struct pci_dev *end, u16 acs_flags)
3404{
3405 struct pci_dev *pdev, *parent = start;
3406
3407 do {
3408 pdev = parent;
3409
3410 if (!pci_acs_enabled(pdev, acs_flags))
3411 return false;
3412
3413 if (pci_is_root_bus(pdev->bus))
3414 return (end == NULL);
3415
3416 parent = pdev->bus->self;
3417 } while (pdev != end);
3418
3419 return true;
3420}
3421
3422/**
3423 * pci_rebar_find_pos - find position of resize ctrl reg for BAR
3424 * @pdev: PCI device
3425 * @bar: BAR to find
3426 *
3427 * Helper to find the position of the ctrl register for a BAR.
3428 * Returns -ENOTSUPP if resizable BARs are not supported at all.
3429 * Returns -ENOENT if no ctrl register for the BAR could be found.
3430 */
3431static int pci_rebar_find_pos(struct pci_dev *pdev, int bar)
3432{
3433 unsigned int pos, nbars, i;
3434 u32 ctrl;
3435
3436 pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR);
3437 if (!pos)
3438 return -ENOTSUPP;
3439
3440 pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
3441 nbars = (ctrl & PCI_REBAR_CTRL_NBAR_MASK) >>
3442 PCI_REBAR_CTRL_NBAR_SHIFT;
3443
3444 for (i = 0; i < nbars; i++, pos += 8) {
3445 int bar_idx;
3446
3447 pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
3448 bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX;
3449 if (bar_idx == bar)
3450 return pos;
3451 }
3452
3453 return -ENOENT;
3454}
3455
3456/**
3457 * pci_rebar_get_possible_sizes - get possible sizes for BAR
3458 * @pdev: PCI device
3459 * @bar: BAR to query
3460 *
3461 * Get the possible sizes of a resizable BAR as bitmask defined in the spec
3462 * (bit 0=1MB, bit 19=512GB). Returns 0 if BAR isn't resizable.
3463 */
3464u32 pci_rebar_get_possible_sizes(struct pci_dev *pdev, int bar)
3465{
3466 int pos;
3467 u32 cap;
3468
3469 pos = pci_rebar_find_pos(pdev, bar);
3470 if (pos < 0)
3471 return 0;
3472
3473 pci_read_config_dword(pdev, pos + PCI_REBAR_CAP, &cap);
3474 return (cap & PCI_REBAR_CAP_SIZES) >> 4;
3475}
3476
3477/**
3478 * pci_rebar_get_current_size - get the current size of a BAR
3479 * @pdev: PCI device
3480 * @bar: BAR to set size to
3481 *
3482 * Read the size of a BAR from the resizable BAR config.
3483 * Returns size if found or negative error code.
3484 */
3485int pci_rebar_get_current_size(struct pci_dev *pdev, int bar)
3486{
3487 int pos;
3488 u32 ctrl;
3489
3490 pos = pci_rebar_find_pos(pdev, bar);
3491 if (pos < 0)
3492 return pos;
3493
3494 pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
3495 return (ctrl & PCI_REBAR_CTRL_BAR_SIZE) >> PCI_REBAR_CTRL_BAR_SHIFT;
3496}
3497
3498/**
3499 * pci_rebar_set_size - set a new size for a BAR
3500 * @pdev: PCI device
3501 * @bar: BAR to set size to
3502 * @size: new size as defined in the spec (0=1MB, 19=512GB)
3503 *
3504 * Set the new size of a BAR as defined in the spec.
3505 * Returns zero if resizing was successful, error code otherwise.
3506 */
3507int pci_rebar_set_size(struct pci_dev *pdev, int bar, int size)
3508{
3509 int pos;
3510 u32 ctrl;
3511
3512 pos = pci_rebar_find_pos(pdev, bar);
3513 if (pos < 0)
3514 return pos;
3515
3516 pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
3517 ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE;
3518 ctrl |= size << PCI_REBAR_CTRL_BAR_SHIFT;
3519 pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl);
3520 return 0;
3521}
3522
3523/**
3524 * pci_enable_atomic_ops_to_root - enable AtomicOp requests to root port
3525 * @dev: the PCI device
3526 * @cap_mask: mask of desired AtomicOp sizes, including one or more of:
3527 * PCI_EXP_DEVCAP2_ATOMIC_COMP32
3528 * PCI_EXP_DEVCAP2_ATOMIC_COMP64
3529 * PCI_EXP_DEVCAP2_ATOMIC_COMP128
3530 *
3531 * Return 0 if all upstream bridges support AtomicOp routing, egress
3532 * blocking is disabled on all upstream ports, and the root port supports
3533 * the requested completion capabilities (32-bit, 64-bit and/or 128-bit
3534 * AtomicOp completion), or negative otherwise.
3535 */
3536int pci_enable_atomic_ops_to_root(struct pci_dev *dev, u32 cap_mask)
3537{
3538 struct pci_bus *bus = dev->bus;
3539 struct pci_dev *bridge;
3540 u32 cap, ctl2;
3541
3542 if (!pci_is_pcie(dev))
3543 return -EINVAL;
3544
3545 /*
3546 * Per PCIe r4.0, sec 6.15, endpoints and root ports may be
3547 * AtomicOp requesters. For now, we only support endpoints as
3548 * requesters and root ports as completers. No endpoints as
3549 * completers, and no peer-to-peer.
3550 */
3551
3552 switch (pci_pcie_type(dev)) {
3553 case PCI_EXP_TYPE_ENDPOINT:
3554 case PCI_EXP_TYPE_LEG_END:
3555 case PCI_EXP_TYPE_RC_END:
3556 break;
3557 default:
3558 return -EINVAL;
3559 }
3560
3561 while (bus->parent) {
3562 bridge = bus->self;
3563
3564 pcie_capability_read_dword(bridge, PCI_EXP_DEVCAP2, &cap);
3565
3566 switch (pci_pcie_type(bridge)) {
3567 /* Ensure switch ports support AtomicOp routing */
3568 case PCI_EXP_TYPE_UPSTREAM:
3569 case PCI_EXP_TYPE_DOWNSTREAM:
3570 if (!(cap & PCI_EXP_DEVCAP2_ATOMIC_ROUTE))
3571 return -EINVAL;
3572 break;
3573
3574 /* Ensure root port supports all the sizes we care about */
3575 case PCI_EXP_TYPE_ROOT_PORT:
3576 if ((cap & cap_mask) != cap_mask)
3577 return -EINVAL;
3578 break;
3579 }
3580
3581 /* Ensure upstream ports don't block AtomicOps on egress */
3582 if (pci_pcie_type(bridge) == PCI_EXP_TYPE_UPSTREAM) {
3583 pcie_capability_read_dword(bridge, PCI_EXP_DEVCTL2,
3584 &ctl2);
3585 if (ctl2 & PCI_EXP_DEVCTL2_ATOMIC_EGRESS_BLOCK)
3586 return -EINVAL;
3587 }
3588
3589 bus = bus->parent;
3590 }
3591
3592 pcie_capability_set_word(dev, PCI_EXP_DEVCTL2,
3593 PCI_EXP_DEVCTL2_ATOMIC_REQ);
3594 return 0;
3595}
3596EXPORT_SYMBOL(pci_enable_atomic_ops_to_root);
3597
3598/**
3599 * pci_swizzle_interrupt_pin - swizzle INTx for device behind bridge
3600 * @dev: the PCI device
3601 * @pin: the INTx pin (1=INTA, 2=INTB, 3=INTC, 4=INTD)
3602 *
3603 * Perform INTx swizzling for a device behind one level of bridge. This is
3604 * required by section 9.1 of the PCI-to-PCI bridge specification for devices
3605 * behind bridges on add-in cards. For devices with ARI enabled, the slot
3606 * number is always 0 (see the Implementation Note in section 2.2.8.1 of
3607 * the PCI Express Base Specification, Revision 2.1)
3608 */
3609u8 pci_swizzle_interrupt_pin(const struct pci_dev *dev, u8 pin)
3610{
3611 int slot;
3612
3613 if (pci_ari_enabled(dev->bus))
3614 slot = 0;
3615 else
3616 slot = PCI_SLOT(dev->devfn);
3617
3618 return (((pin - 1) + slot) % 4) + 1;
3619}
3620
3621int pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge)
3622{
3623 u8 pin;
3624
3625 pin = dev->pin;
3626 if (!pin)
3627 return -1;
3628
3629 while (!pci_is_root_bus(dev->bus)) {
3630 pin = pci_swizzle_interrupt_pin(dev, pin);
3631 dev = dev->bus->self;
3632 }
3633 *bridge = dev;
3634 return pin;
3635}
3636
3637/**
3638 * pci_common_swizzle - swizzle INTx all the way to root bridge
3639 * @dev: the PCI device
3640 * @pinp: pointer to the INTx pin value (1=INTA, 2=INTB, 3=INTD, 4=INTD)
3641 *
3642 * Perform INTx swizzling for a device. This traverses through all PCI-to-PCI
3643 * bridges all the way up to a PCI root bus.
3644 */
3645u8 pci_common_swizzle(struct pci_dev *dev, u8 *pinp)
3646{
3647 u8 pin = *pinp;
3648
3649 while (!pci_is_root_bus(dev->bus)) {
3650 pin = pci_swizzle_interrupt_pin(dev, pin);
3651 dev = dev->bus->self;
3652 }
3653 *pinp = pin;
3654 return PCI_SLOT(dev->devfn);
3655}
3656EXPORT_SYMBOL_GPL(pci_common_swizzle);
3657
3658/**
3659 * pci_release_region - Release a PCI bar
3660 * @pdev: PCI device whose resources were previously reserved by
3661 * pci_request_region()
3662 * @bar: BAR to release
3663 *
3664 * Releases the PCI I/O and memory resources previously reserved by a
3665 * successful call to pci_request_region(). Call this function only
3666 * after all use of the PCI regions has ceased.
3667 */
3668void pci_release_region(struct pci_dev *pdev, int bar)
3669{
3670 struct pci_devres *dr;
3671
3672 if (pci_resource_len(pdev, bar) == 0)
3673 return;
3674 if (pci_resource_flags(pdev, bar) & IORESOURCE_IO)
3675 release_region(pci_resource_start(pdev, bar),
3676 pci_resource_len(pdev, bar));
3677 else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM)
3678 release_mem_region(pci_resource_start(pdev, bar),
3679 pci_resource_len(pdev, bar));
3680
3681 dr = find_pci_dr(pdev);
3682 if (dr)
3683 dr->region_mask &= ~(1 << bar);
3684}
3685EXPORT_SYMBOL(pci_release_region);
3686
3687/**
3688 * __pci_request_region - Reserved PCI I/O and memory resource
3689 * @pdev: PCI device whose resources are to be reserved
3690 * @bar: BAR to be reserved
3691 * @res_name: Name to be associated with resource.
3692 * @exclusive: whether the region access is exclusive or not
3693 *
3694 * Mark the PCI region associated with PCI device @pdev BAR @bar as
3695 * being reserved by owner @res_name. Do not access any
3696 * address inside the PCI regions unless this call returns
3697 * successfully.
3698 *
3699 * If @exclusive is set, then the region is marked so that userspace
3700 * is explicitly not allowed to map the resource via /dev/mem or
3701 * sysfs MMIO access.
3702 *
3703 * Returns 0 on success, or %EBUSY on error. A warning
3704 * message is also printed on failure.
3705 */
3706static int __pci_request_region(struct pci_dev *pdev, int bar,
3707 const char *res_name, int exclusive)
3708{
3709 struct pci_devres *dr;
3710
3711 if (pci_resource_len(pdev, bar) == 0)
3712 return 0;
3713
3714 if (pci_resource_flags(pdev, bar) & IORESOURCE_IO) {
3715 if (!request_region(pci_resource_start(pdev, bar),
3716 pci_resource_len(pdev, bar), res_name))
3717 goto err_out;
3718 } else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM) {
3719 if (!__request_mem_region(pci_resource_start(pdev, bar),
3720 pci_resource_len(pdev, bar), res_name,
3721 exclusive))
3722 goto err_out;
3723 }
3724
3725 dr = find_pci_dr(pdev);
3726 if (dr)
3727 dr->region_mask |= 1 << bar;
3728
3729 return 0;
3730
3731err_out:
3732 pci_warn(pdev, "BAR %d: can't reserve %pR\n", bar,
3733 &pdev->resource[bar]);
3734 return -EBUSY;
3735}
3736
3737/**
3738 * pci_request_region - Reserve PCI I/O and memory resource
3739 * @pdev: PCI device whose resources are to be reserved
3740 * @bar: BAR to be reserved
3741 * @res_name: Name to be associated with resource
3742 *
3743 * Mark the PCI region associated with PCI device @pdev BAR @bar as
3744 * being reserved by owner @res_name. Do not access any
3745 * address inside the PCI regions unless this call returns
3746 * successfully.
3747 *
3748 * Returns 0 on success, or %EBUSY on error. A warning
3749 * message is also printed on failure.
3750 */
3751int pci_request_region(struct pci_dev *pdev, int bar, const char *res_name)
3752{
3753 return __pci_request_region(pdev, bar, res_name, 0);
3754}
3755EXPORT_SYMBOL(pci_request_region);
3756
3757/**
3758 * pci_release_selected_regions - Release selected PCI I/O and memory resources
3759 * @pdev: PCI device whose resources were previously reserved
3760 * @bars: Bitmask of BARs to be released
3761 *
3762 * Release selected PCI I/O and memory resources previously reserved.
3763 * Call this function only after all use of the PCI regions has ceased.
3764 */
3765void pci_release_selected_regions(struct pci_dev *pdev, int bars)
3766{
3767 int i;
3768
3769 for (i = 0; i < 6; i++)
3770 if (bars & (1 << i))
3771 pci_release_region(pdev, i);
3772}
3773EXPORT_SYMBOL(pci_release_selected_regions);
3774
3775static int __pci_request_selected_regions(struct pci_dev *pdev, int bars,
3776 const char *res_name, int excl)
3777{
3778 int i;
3779
3780 for (i = 0; i < 6; i++)
3781 if (bars & (1 << i))
3782 if (__pci_request_region(pdev, i, res_name, excl))
3783 goto err_out;
3784 return 0;
3785
3786err_out:
3787 while (--i >= 0)
3788 if (bars & (1 << i))
3789 pci_release_region(pdev, i);
3790
3791 return -EBUSY;
3792}
3793
3794
3795/**
3796 * pci_request_selected_regions - Reserve selected PCI I/O and memory resources
3797 * @pdev: PCI device whose resources are to be reserved
3798 * @bars: Bitmask of BARs to be requested
3799 * @res_name: Name to be associated with resource
3800 */
3801int pci_request_selected_regions(struct pci_dev *pdev, int bars,
3802 const char *res_name)
3803{
3804 return __pci_request_selected_regions(pdev, bars, res_name, 0);
3805}
3806EXPORT_SYMBOL(pci_request_selected_regions);
3807
3808int pci_request_selected_regions_exclusive(struct pci_dev *pdev, int bars,
3809 const char *res_name)
3810{
3811 return __pci_request_selected_regions(pdev, bars, res_name,
3812 IORESOURCE_EXCLUSIVE);
3813}
3814EXPORT_SYMBOL(pci_request_selected_regions_exclusive);
3815
3816/**
3817 * pci_release_regions - Release reserved PCI I/O and memory resources
3818 * @pdev: PCI device whose resources were previously reserved by
3819 * pci_request_regions()
3820 *
3821 * Releases all PCI I/O and memory resources previously reserved by a
3822 * successful call to pci_request_regions(). Call this function only
3823 * after all use of the PCI regions has ceased.
3824 */
3825
3826void pci_release_regions(struct pci_dev *pdev)
3827{
3828 pci_release_selected_regions(pdev, (1 << 6) - 1);
3829}
3830EXPORT_SYMBOL(pci_release_regions);
3831
3832/**
3833 * pci_request_regions - Reserve PCI I/O and memory resources
3834 * @pdev: PCI device whose resources are to be reserved
3835 * @res_name: Name to be associated with resource.
3836 *
3837 * Mark all PCI regions associated with PCI device @pdev as
3838 * being reserved by owner @res_name. Do not access any
3839 * address inside the PCI regions unless this call returns
3840 * successfully.
3841 *
3842 * Returns 0 on success, or %EBUSY on error. A warning
3843 * message is also printed on failure.
3844 */
3845int pci_request_regions(struct pci_dev *pdev, const char *res_name)
3846{
3847 return pci_request_selected_regions(pdev, ((1 << 6) - 1), res_name);
3848}
3849EXPORT_SYMBOL(pci_request_regions);
3850
3851/**
3852 * pci_request_regions_exclusive - Reserve PCI I/O and memory resources
3853 * @pdev: PCI device whose resources are to be reserved
3854 * @res_name: Name to be associated with resource.
3855 *
3856 * Mark all PCI regions associated with PCI device @pdev as being reserved
3857 * by owner @res_name. Do not access any address inside the PCI regions
3858 * unless this call returns successfully.
3859 *
3860 * pci_request_regions_exclusive() will mark the region so that /dev/mem
3861 * and the sysfs MMIO access will not be allowed.
3862 *
3863 * Returns 0 on success, or %EBUSY on error. A warning message is also
3864 * printed on failure.
3865 */
3866int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name)
3867{
3868 return pci_request_selected_regions_exclusive(pdev,
3869 ((1 << 6) - 1), res_name);
3870}
3871EXPORT_SYMBOL(pci_request_regions_exclusive);
3872
3873/*
3874 * Record the PCI IO range (expressed as CPU physical address + size).
3875 * Return a negative value if an error has occurred, zero otherwise
3876 */
3877int pci_register_io_range(struct fwnode_handle *fwnode, phys_addr_t addr,
3878 resource_size_t size)
3879{
3880 int ret = 0;
3881#ifdef PCI_IOBASE
3882 struct logic_pio_hwaddr *range;
3883
3884 if (!size || addr + size < addr)
3885 return -EINVAL;
3886
3887 range = kzalloc(sizeof(*range), GFP_ATOMIC);
3888 if (!range)
3889 return -ENOMEM;
3890
3891 range->fwnode = fwnode;
3892 range->size = size;
3893 range->hw_start = addr;
3894 range->flags = LOGIC_PIO_CPU_MMIO;
3895
3896 ret = logic_pio_register_range(range);
3897 if (ret)
3898 kfree(range);
3899#endif
3900
3901 return ret;
3902}
3903
3904phys_addr_t pci_pio_to_address(unsigned long pio)
3905{
3906 phys_addr_t address = (phys_addr_t)OF_BAD_ADDR;
3907
3908#ifdef PCI_IOBASE
3909 if (pio >= MMIO_UPPER_LIMIT)
3910 return address;
3911
3912 address = logic_pio_to_hwaddr(pio);
3913#endif
3914
3915 return address;
3916}
3917
3918unsigned long __weak pci_address_to_pio(phys_addr_t address)
3919{
3920#ifdef PCI_IOBASE
3921 return logic_pio_trans_cpuaddr(address);
3922#else
3923 if (address > IO_SPACE_LIMIT)
3924 return (unsigned long)-1;
3925
3926 return (unsigned long) address;
3927#endif
3928}
3929
3930/**
3931 * pci_remap_iospace - Remap the memory mapped I/O space
3932 * @res: Resource describing the I/O space
3933 * @phys_addr: physical address of range to be mapped
3934 *
3935 * Remap the memory mapped I/O space described by the @res and the CPU
3936 * physical address @phys_addr into virtual address space. Only
3937 * architectures that have memory mapped IO functions defined (and the
3938 * PCI_IOBASE value defined) should call this function.
3939 */
3940int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr)
3941{
3942#if defined(PCI_IOBASE) && defined(CONFIG_MMU)
3943 unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start;
3944
3945 if (!(res->flags & IORESOURCE_IO))
3946 return -EINVAL;
3947
3948 if (res->end > IO_SPACE_LIMIT)
3949 return -EINVAL;
3950
3951 return ioremap_page_range(vaddr, vaddr + resource_size(res), phys_addr,
3952 pgprot_device(PAGE_KERNEL));
3953#else
3954 /*
3955 * This architecture does not have memory mapped I/O space,
3956 * so this function should never be called
3957 */
3958 WARN_ONCE(1, "This architecture does not support memory mapped I/O\n");
3959 return -ENODEV;
3960#endif
3961}
3962EXPORT_SYMBOL(pci_remap_iospace);
3963
3964/**
3965 * pci_unmap_iospace - Unmap the memory mapped I/O space
3966 * @res: resource to be unmapped
3967 *
3968 * Unmap the CPU virtual address @res from virtual address space. Only
3969 * architectures that have memory mapped IO functions defined (and the
3970 * PCI_IOBASE value defined) should call this function.
3971 */
3972void pci_unmap_iospace(struct resource *res)
3973{
3974#if defined(PCI_IOBASE) && defined(CONFIG_MMU)
3975 unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start;
3976
3977 unmap_kernel_range(vaddr, resource_size(res));
3978#endif
3979}
3980EXPORT_SYMBOL(pci_unmap_iospace);
3981
3982static void devm_pci_unmap_iospace(struct device *dev, void *ptr)
3983{
3984 struct resource **res = ptr;
3985
3986 pci_unmap_iospace(*res);
3987}
3988
3989/**
3990 * devm_pci_remap_iospace - Managed pci_remap_iospace()
3991 * @dev: Generic device to remap IO address for
3992 * @res: Resource describing the I/O space
3993 * @phys_addr: physical address of range to be mapped
3994 *
3995 * Managed pci_remap_iospace(). Map is automatically unmapped on driver
3996 * detach.
3997 */
3998int devm_pci_remap_iospace(struct device *dev, const struct resource *res,
3999 phys_addr_t phys_addr)
4000{
4001 const struct resource **ptr;
4002 int error;
4003
4004 ptr = devres_alloc(devm_pci_unmap_iospace, sizeof(*ptr), GFP_KERNEL);
4005 if (!ptr)
4006 return -ENOMEM;
4007
4008 error = pci_remap_iospace(res, phys_addr);
4009 if (error) {
4010 devres_free(ptr);
4011 } else {
4012 *ptr = res;
4013 devres_add(dev, ptr);
4014 }
4015
4016 return error;
4017}
4018EXPORT_SYMBOL(devm_pci_remap_iospace);
4019
4020/**
4021 * devm_pci_remap_cfgspace - Managed pci_remap_cfgspace()
4022 * @dev: Generic device to remap IO address for
4023 * @offset: Resource address to map
4024 * @size: Size of map
4025 *
4026 * Managed pci_remap_cfgspace(). Map is automatically unmapped on driver
4027 * detach.
4028 */
4029void __iomem *devm_pci_remap_cfgspace(struct device *dev,
4030 resource_size_t offset,
4031 resource_size_t size)
4032{
4033 void __iomem **ptr, *addr;
4034
4035 ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL);
4036 if (!ptr)
4037 return NULL;
4038
4039 addr = pci_remap_cfgspace(offset, size);
4040 if (addr) {
4041 *ptr = addr;
4042 devres_add(dev, ptr);
4043 } else
4044 devres_free(ptr);
4045
4046 return addr;
4047}
4048EXPORT_SYMBOL(devm_pci_remap_cfgspace);
4049
4050/**
4051 * devm_pci_remap_cfg_resource - check, request region and ioremap cfg resource
4052 * @dev: generic device to handle the resource for
4053 * @res: configuration space resource to be handled
4054 *
4055 * Checks that a resource is a valid memory region, requests the memory
4056 * region and ioremaps with pci_remap_cfgspace() API that ensures the
4057 * proper PCI configuration space memory attributes are guaranteed.
4058 *
4059 * All operations are managed and will be undone on driver detach.
4060 *
4061 * Returns a pointer to the remapped memory or an ERR_PTR() encoded error code
4062 * on failure. Usage example::
4063 *
4064 * res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
4065 * base = devm_pci_remap_cfg_resource(&pdev->dev, res);
4066 * if (IS_ERR(base))
4067 * return PTR_ERR(base);
4068 */
4069void __iomem *devm_pci_remap_cfg_resource(struct device *dev,
4070 struct resource *res)
4071{
4072 resource_size_t size;
4073 const char *name;
4074 void __iomem *dest_ptr;
4075
4076 BUG_ON(!dev);
4077
4078 if (!res || resource_type(res) != IORESOURCE_MEM) {
4079 dev_err(dev, "invalid resource\n");
4080 return IOMEM_ERR_PTR(-EINVAL);
4081 }
4082
4083 size = resource_size(res);
4084 name = res->name ?: dev_name(dev);
4085
4086 if (!devm_request_mem_region(dev, res->start, size, name)) {
4087 dev_err(dev, "can't request region for resource %pR\n", res);
4088 return IOMEM_ERR_PTR(-EBUSY);
4089 }
4090
4091 dest_ptr = devm_pci_remap_cfgspace(dev, res->start, size);
4092 if (!dest_ptr) {
4093 dev_err(dev, "ioremap failed for resource %pR\n", res);
4094 devm_release_mem_region(dev, res->start, size);
4095 dest_ptr = IOMEM_ERR_PTR(-ENOMEM);
4096 }
4097
4098 return dest_ptr;
4099}
4100EXPORT_SYMBOL(devm_pci_remap_cfg_resource);
4101
4102static void __pci_set_master(struct pci_dev *dev, bool enable)
4103{
4104 u16 old_cmd, cmd;
4105
4106 pci_read_config_word(dev, PCI_COMMAND, &old_cmd);
4107 if (enable)
4108 cmd = old_cmd | PCI_COMMAND_MASTER;
4109 else
4110 cmd = old_cmd & ~PCI_COMMAND_MASTER;
4111 if (cmd != old_cmd) {
4112 pci_dbg(dev, "%s bus mastering\n",
4113 enable ? "enabling" : "disabling");
4114 pci_write_config_word(dev, PCI_COMMAND, cmd);
4115 }
4116 dev->is_busmaster = enable;
4117}
4118
4119/**
4120 * pcibios_setup - process "pci=" kernel boot arguments
4121 * @str: string used to pass in "pci=" kernel boot arguments
4122 *
4123 * Process kernel boot arguments. This is the default implementation.
4124 * Architecture specific implementations can override this as necessary.
4125 */
4126char * __weak __init pcibios_setup(char *str)
4127{
4128 return str;
4129}
4130
4131/**
4132 * pcibios_set_master - enable PCI bus-mastering for device dev
4133 * @dev: the PCI device to enable
4134 *
4135 * Enables PCI bus-mastering for the device. This is the default
4136 * implementation. Architecture specific implementations can override
4137 * this if necessary.
4138 */
4139void __weak pcibios_set_master(struct pci_dev *dev)
4140{
4141 u8 lat;
4142
4143 /* The latency timer doesn't apply to PCIe (either Type 0 or Type 1) */
4144 if (pci_is_pcie(dev))
4145 return;
4146
4147 pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat);
4148 if (lat < 16)
4149 lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency;
4150 else if (lat > pcibios_max_latency)
4151 lat = pcibios_max_latency;
4152 else
4153 return;
4154
4155 pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat);
4156}
4157
4158/**
4159 * pci_set_master - enables bus-mastering for device dev
4160 * @dev: the PCI device to enable
4161 *
4162 * Enables bus-mastering on the device and calls pcibios_set_master()
4163 * to do the needed arch specific settings.
4164 */
4165void pci_set_master(struct pci_dev *dev)
4166{
4167 __pci_set_master(dev, true);
4168 pcibios_set_master(dev);
4169}
4170EXPORT_SYMBOL(pci_set_master);
4171
4172/**
4173 * pci_clear_master - disables bus-mastering for device dev
4174 * @dev: the PCI device to disable
4175 */
4176void pci_clear_master(struct pci_dev *dev)
4177{
4178 __pci_set_master(dev, false);
4179}
4180EXPORT_SYMBOL(pci_clear_master);
4181
4182/**
4183 * pci_set_cacheline_size - ensure the CACHE_LINE_SIZE register is programmed
4184 * @dev: the PCI device for which MWI is to be enabled
4185 *
4186 * Helper function for pci_set_mwi.
4187 * Originally copied from drivers/net/acenic.c.
4188 * Copyright 1998-2001 by Jes Sorensen, <jes@trained-monkey.org>.
4189 *
4190 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
4191 */
4192int pci_set_cacheline_size(struct pci_dev *dev)
4193{
4194 u8 cacheline_size;
4195
4196 if (!pci_cache_line_size)
4197 return -EINVAL;
4198
4199 /* Validate current setting: the PCI_CACHE_LINE_SIZE must be
4200 equal to or multiple of the right value. */
4201 pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
4202 if (cacheline_size >= pci_cache_line_size &&
4203 (cacheline_size % pci_cache_line_size) == 0)
4204 return 0;
4205
4206 /* Write the correct value. */
4207 pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, pci_cache_line_size);
4208 /* Read it back. */
4209 pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
4210 if (cacheline_size == pci_cache_line_size)
4211 return 0;
4212
4213 pci_info(dev, "cache line size of %d is not supported\n",
4214 pci_cache_line_size << 2);
4215
4216 return -EINVAL;
4217}
4218EXPORT_SYMBOL_GPL(pci_set_cacheline_size);
4219
4220/**
4221 * pci_set_mwi - enables memory-write-invalidate PCI transaction
4222 * @dev: the PCI device for which MWI is enabled
4223 *
4224 * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND.
4225 *
4226 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
4227 */
4228int pci_set_mwi(struct pci_dev *dev)
4229{
4230#ifdef PCI_DISABLE_MWI
4231 return 0;
4232#else
4233 int rc;
4234 u16 cmd;
4235
4236 rc = pci_set_cacheline_size(dev);
4237 if (rc)
4238 return rc;
4239
4240 pci_read_config_word(dev, PCI_COMMAND, &cmd);
4241 if (!(cmd & PCI_COMMAND_INVALIDATE)) {
4242 pci_dbg(dev, "enabling Mem-Wr-Inval\n");
4243 cmd |= PCI_COMMAND_INVALIDATE;
4244 pci_write_config_word(dev, PCI_COMMAND, cmd);
4245 }
4246 return 0;
4247#endif
4248}
4249EXPORT_SYMBOL(pci_set_mwi);
4250
4251/**
4252 * pcim_set_mwi - a device-managed pci_set_mwi()
4253 * @dev: the PCI device for which MWI is enabled
4254 *
4255 * Managed pci_set_mwi().
4256 *
4257 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
4258 */
4259int pcim_set_mwi(struct pci_dev *dev)
4260{
4261 struct pci_devres *dr;
4262
4263 dr = find_pci_dr(dev);
4264 if (!dr)
4265 return -ENOMEM;
4266
4267 dr->mwi = 1;
4268 return pci_set_mwi(dev);
4269}
4270EXPORT_SYMBOL(pcim_set_mwi);
4271
4272/**
4273 * pci_try_set_mwi - enables memory-write-invalidate PCI transaction
4274 * @dev: the PCI device for which MWI is enabled
4275 *
4276 * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND.
4277 * Callers are not required to check the return value.
4278 *
4279 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
4280 */
4281int pci_try_set_mwi(struct pci_dev *dev)
4282{
4283#ifdef PCI_DISABLE_MWI
4284 return 0;
4285#else
4286 return pci_set_mwi(dev);
4287#endif
4288}
4289EXPORT_SYMBOL(pci_try_set_mwi);
4290
4291/**
4292 * pci_clear_mwi - disables Memory-Write-Invalidate for device dev
4293 * @dev: the PCI device to disable
4294 *
4295 * Disables PCI Memory-Write-Invalidate transaction on the device
4296 */
4297void pci_clear_mwi(struct pci_dev *dev)
4298{
4299#ifndef PCI_DISABLE_MWI
4300 u16 cmd;
4301
4302 pci_read_config_word(dev, PCI_COMMAND, &cmd);
4303 if (cmd & PCI_COMMAND_INVALIDATE) {
4304 cmd &= ~PCI_COMMAND_INVALIDATE;
4305 pci_write_config_word(dev, PCI_COMMAND, cmd);
4306 }
4307#endif
4308}
4309EXPORT_SYMBOL(pci_clear_mwi);
4310
4311/**
4312 * pci_intx - enables/disables PCI INTx for device dev
4313 * @pdev: the PCI device to operate on
4314 * @enable: boolean: whether to enable or disable PCI INTx
4315 *
4316 * Enables/disables PCI INTx for device @pdev
4317 */
4318void pci_intx(struct pci_dev *pdev, int enable)
4319{
4320 u16 pci_command, new;
4321
4322 pci_read_config_word(pdev, PCI_COMMAND, &pci_command);
4323
4324 if (enable)
4325 new = pci_command & ~PCI_COMMAND_INTX_DISABLE;
4326 else
4327 new = pci_command | PCI_COMMAND_INTX_DISABLE;
4328
4329 if (new != pci_command) {
4330 struct pci_devres *dr;
4331
4332 pci_write_config_word(pdev, PCI_COMMAND, new);
4333
4334 dr = find_pci_dr(pdev);
4335 if (dr && !dr->restore_intx) {
4336 dr->restore_intx = 1;
4337 dr->orig_intx = !enable;
4338 }
4339 }
4340}
4341EXPORT_SYMBOL_GPL(pci_intx);
4342
4343static bool pci_check_and_set_intx_mask(struct pci_dev *dev, bool mask)
4344{
4345 struct pci_bus *bus = dev->bus;
4346 bool mask_updated = true;
4347 u32 cmd_status_dword;
4348 u16 origcmd, newcmd;
4349 unsigned long flags;
4350 bool irq_pending;
4351
4352 /*
4353 * We do a single dword read to retrieve both command and status.
4354 * Document assumptions that make this possible.
4355 */
4356 BUILD_BUG_ON(PCI_COMMAND % 4);
4357 BUILD_BUG_ON(PCI_COMMAND + 2 != PCI_STATUS);
4358
4359 raw_spin_lock_irqsave(&pci_lock, flags);
4360
4361 bus->ops->read(bus, dev->devfn, PCI_COMMAND, 4, &cmd_status_dword);
4362
4363 irq_pending = (cmd_status_dword >> 16) & PCI_STATUS_INTERRUPT;
4364
4365 /*
4366 * Check interrupt status register to see whether our device
4367 * triggered the interrupt (when masking) or the next IRQ is
4368 * already pending (when unmasking).
4369 */
4370 if (mask != irq_pending) {
4371 mask_updated = false;
4372 goto done;
4373 }
4374
4375 origcmd = cmd_status_dword;
4376 newcmd = origcmd & ~PCI_COMMAND_INTX_DISABLE;
4377 if (mask)
4378 newcmd |= PCI_COMMAND_INTX_DISABLE;
4379 if (newcmd != origcmd)
4380 bus->ops->write(bus, dev->devfn, PCI_COMMAND, 2, newcmd);
4381
4382done:
4383 raw_spin_unlock_irqrestore(&pci_lock, flags);
4384
4385 return mask_updated;
4386}
4387
4388/**
4389 * pci_check_and_mask_intx - mask INTx on pending interrupt
4390 * @dev: the PCI device to operate on
4391 *
4392 * Check if the device dev has its INTx line asserted, mask it and return
4393 * true in that case. False is returned if no interrupt was pending.
4394 */
4395bool pci_check_and_mask_intx(struct pci_dev *dev)
4396{
4397 return pci_check_and_set_intx_mask(dev, true);
4398}
4399EXPORT_SYMBOL_GPL(pci_check_and_mask_intx);
4400
4401/**
4402 * pci_check_and_unmask_intx - unmask INTx if no interrupt is pending
4403 * @dev: the PCI device to operate on
4404 *
4405 * Check if the device dev has its INTx line asserted, unmask it if not and
4406 * return true. False is returned and the mask remains active if there was
4407 * still an interrupt pending.
4408 */
4409bool pci_check_and_unmask_intx(struct pci_dev *dev)
4410{
4411 return pci_check_and_set_intx_mask(dev, false);
4412}
4413EXPORT_SYMBOL_GPL(pci_check_and_unmask_intx);
4414
4415/**
4416 * pci_wait_for_pending_transaction - wait for pending transaction
4417 * @dev: the PCI device to operate on
4418 *
4419 * Return 0 if transaction is pending 1 otherwise.
4420 */
4421int pci_wait_for_pending_transaction(struct pci_dev *dev)
4422{
4423 if (!pci_is_pcie(dev))
4424 return 1;
4425
4426 return pci_wait_for_pending(dev, pci_pcie_cap(dev) + PCI_EXP_DEVSTA,
4427 PCI_EXP_DEVSTA_TRPND);
4428}
4429EXPORT_SYMBOL(pci_wait_for_pending_transaction);
4430
4431static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout)
4432{
4433 int delay = 1;
4434 u32 id;
4435
4436 /*
4437 * After reset, the device should not silently discard config
4438 * requests, but it may still indicate that it needs more time by
4439 * responding to them with CRS completions. The Root Port will
4440 * generally synthesize ~0 data to complete the read (except when
4441 * CRS SV is enabled and the read was for the Vendor ID; in that
4442 * case it synthesizes 0x0001 data).
4443 *
4444 * Wait for the device to return a non-CRS completion. Read the
4445 * Command register instead of Vendor ID so we don't have to
4446 * contend with the CRS SV value.
4447 */
4448 pci_read_config_dword(dev, PCI_COMMAND, &id);
4449 while (id == ~0) {
4450 if (delay > timeout) {
4451 pci_warn(dev, "not ready %dms after %s; giving up\n",
4452 delay - 1, reset_type);
4453 return -ENOTTY;
4454 }
4455
4456 if (delay > 1000)
4457 pci_info(dev, "not ready %dms after %s; waiting\n",
4458 delay - 1, reset_type);
4459
4460 msleep(delay);
4461 delay *= 2;
4462 pci_read_config_dword(dev, PCI_COMMAND, &id);
4463 }
4464
4465 if (delay > 1000)
4466 pci_info(dev, "ready %dms after %s\n", delay - 1,
4467 reset_type);
4468
4469 return 0;
4470}
4471
4472/**
4473 * pcie_has_flr - check if a device supports function level resets
4474 * @dev: device to check
4475 *
4476 * Returns true if the device advertises support for PCIe function level
4477 * resets.
4478 */
4479bool pcie_has_flr(struct pci_dev *dev)
4480{
4481 u32 cap;
4482
4483 if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
4484 return false;
4485
4486 pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap);
4487 return cap & PCI_EXP_DEVCAP_FLR;
4488}
4489EXPORT_SYMBOL_GPL(pcie_has_flr);
4490
4491/**
4492 * pcie_flr - initiate a PCIe function level reset
4493 * @dev: device to reset
4494 *
4495 * Initiate a function level reset on @dev. The caller should ensure the
4496 * device supports FLR before calling this function, e.g. by using the
4497 * pcie_has_flr() helper.
4498 */
4499int pcie_flr(struct pci_dev *dev)
4500{
4501 if (!pci_wait_for_pending_transaction(dev))
4502 pci_err(dev, "timed out waiting for pending transaction; performing function level reset anyway\n");
4503
4504 pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR);
4505
4506 if (dev->imm_ready)
4507 return 0;
4508
4509 /*
4510 * Per PCIe r4.0, sec 6.6.2, a device must complete an FLR within
4511 * 100ms, but may silently discard requests while the FLR is in
4512 * progress. Wait 100ms before trying to access the device.
4513 */
4514 msleep(100);
4515
4516 return pci_dev_wait(dev, "FLR", PCIE_RESET_READY_POLL_MS);
4517}
4518EXPORT_SYMBOL_GPL(pcie_flr);
4519
4520static int pci_af_flr(struct pci_dev *dev, int probe)
4521{
4522 int pos;
4523 u8 cap;
4524
4525 pos = pci_find_capability(dev, PCI_CAP_ID_AF);
4526 if (!pos)
4527 return -ENOTTY;
4528
4529 if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
4530 return -ENOTTY;
4531
4532 pci_read_config_byte(dev, pos + PCI_AF_CAP, &cap);
4533 if (!(cap & PCI_AF_CAP_TP) || !(cap & PCI_AF_CAP_FLR))
4534 return -ENOTTY;
4535
4536 if (probe)
4537 return 0;
4538
4539 /*
4540 * Wait for Transaction Pending bit to clear. A word-aligned test
4541 * is used, so we use the control offset rather than status and shift
4542 * the test bit to match.
4543 */
4544 if (!pci_wait_for_pending(dev, pos + PCI_AF_CTRL,
4545 PCI_AF_STATUS_TP << 8))
4546 pci_err(dev, "timed out waiting for pending transaction; performing AF function level reset anyway\n");
4547
4548 pci_write_config_byte(dev, pos + PCI_AF_CTRL, PCI_AF_CTRL_FLR);
4549
4550 if (dev->imm_ready)
4551 return 0;
4552
4553 /*
4554 * Per Advanced Capabilities for Conventional PCI ECN, 13 April 2006,
4555 * updated 27 July 2006; a device must complete an FLR within
4556 * 100ms, but may silently discard requests while the FLR is in
4557 * progress. Wait 100ms before trying to access the device.
4558 */
4559 msleep(100);
4560
4561 return pci_dev_wait(dev, "AF_FLR", PCIE_RESET_READY_POLL_MS);
4562}
4563
4564/**
4565 * pci_pm_reset - Put device into PCI_D3 and back into PCI_D0.
4566 * @dev: Device to reset.
4567 * @probe: If set, only check if the device can be reset this way.
4568 *
4569 * If @dev supports native PCI PM and its PCI_PM_CTRL_NO_SOFT_RESET flag is
4570 * unset, it will be reinitialized internally when going from PCI_D3hot to
4571 * PCI_D0. If that's the case and the device is not in a low-power state
4572 * already, force it into PCI_D3hot and back to PCI_D0, causing it to be reset.
4573 *
4574 * NOTE: This causes the caller to sleep for twice the device power transition
4575 * cooldown period, which for the D0->D3hot and D3hot->D0 transitions is 10 ms
4576 * by default (i.e. unless the @dev's d3_delay field has a different value).
4577 * Moreover, only devices in D0 can be reset by this function.
4578 */
4579static int pci_pm_reset(struct pci_dev *dev, int probe)
4580{
4581 u16 csr;
4582
4583 if (!dev->pm_cap || dev->dev_flags & PCI_DEV_FLAGS_NO_PM_RESET)
4584 return -ENOTTY;
4585
4586 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &csr);
4587 if (csr & PCI_PM_CTRL_NO_SOFT_RESET)
4588 return -ENOTTY;
4589
4590 if (probe)
4591 return 0;
4592
4593 if (dev->current_state != PCI_D0)
4594 return -EINVAL;
4595
4596 csr &= ~PCI_PM_CTRL_STATE_MASK;
4597 csr |= PCI_D3hot;
4598 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);
4599 pci_dev_d3_sleep(dev);
4600
4601 csr &= ~PCI_PM_CTRL_STATE_MASK;
4602 csr |= PCI_D0;
4603 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);
4604 pci_dev_d3_sleep(dev);
4605
4606 return pci_dev_wait(dev, "PM D3->D0", PCIE_RESET_READY_POLL_MS);
4607}
4608/**
4609 * pcie_wait_for_link - Wait until link is active or inactive
4610 * @pdev: Bridge device
4611 * @active: waiting for active or inactive?
4612 *
4613 * Use this to wait till link becomes active or inactive.
4614 */
4615bool pcie_wait_for_link(struct pci_dev *pdev, bool active)
4616{
4617 int timeout = 1000;
4618 bool ret;
4619 u16 lnk_status;
4620
4621 /*
4622 * Some controllers might not implement link active reporting. In this
4623 * case, we wait for 1000 + 100 ms.
4624 */
4625 if (!pdev->link_active_reporting) {
4626 msleep(1100);
4627 return true;
4628 }
4629
4630 /*
4631 * PCIe r4.0 sec 6.6.1, a component must enter LTSSM Detect within 20ms,
4632 * after which we should expect an link active if the reset was
4633 * successful. If so, software must wait a minimum 100ms before sending
4634 * configuration requests to devices downstream this port.
4635 *
4636 * If the link fails to activate, either the device was physically
4637 * removed or the link is permanently failed.
4638 */
4639 if (active)
4640 msleep(20);
4641 for (;;) {
4642 pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
4643 ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA);
4644 if (ret == active)
4645 break;
4646 if (timeout <= 0)
4647 break;
4648 msleep(10);
4649 timeout -= 10;
4650 }
4651 if (active && ret)
4652 msleep(100);
4653 else if (ret != active)
4654 pci_info(pdev, "Data Link Layer Link Active not %s in 1000 msec\n",
4655 active ? "set" : "cleared");
4656 return ret == active;
4657}
4658
4659void pci_reset_secondary_bus(struct pci_dev *dev)
4660{
4661 u16 ctrl;
4662
4663 pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &ctrl);
4664 ctrl |= PCI_BRIDGE_CTL_BUS_RESET;
4665 pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl);
4666
4667 /*
4668 * PCI spec v3.0 7.6.4.2 requires minimum Trst of 1ms. Double
4669 * this to 2ms to ensure that we meet the minimum requirement.
4670 */
4671 msleep(2);
4672
4673 ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET;
4674 pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl);
4675
4676 /*
4677 * Trhfa for conventional PCI is 2^25 clock cycles.
4678 * Assuming a minimum 33MHz clock this results in a 1s
4679 * delay before we can consider subordinate devices to
4680 * be re-initialized. PCIe has some ways to shorten this,
4681 * but we don't make use of them yet.
4682 */
4683 ssleep(1);
4684}
4685
4686void __weak pcibios_reset_secondary_bus(struct pci_dev *dev)
4687{
4688 pci_reset_secondary_bus(dev);
4689}
4690
4691/**
4692 * pci_bridge_secondary_bus_reset - Reset the secondary bus on a PCI bridge.
4693 * @dev: Bridge device
4694 *
4695 * Use the bridge control register to assert reset on the secondary bus.
4696 * Devices on the secondary bus are left in power-on state.
4697 */
4698int pci_bridge_secondary_bus_reset(struct pci_dev *dev)
4699{
4700 pcibios_reset_secondary_bus(dev);
4701
4702 return pci_dev_wait(dev, "bus reset", PCIE_RESET_READY_POLL_MS);
4703}
4704EXPORT_SYMBOL_GPL(pci_bridge_secondary_bus_reset);
4705
4706static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
4707{
4708 struct pci_dev *pdev;
4709
4710 if (pci_is_root_bus(dev->bus) || dev->subordinate ||
4711 !dev->bus->self || dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)
4712 return -ENOTTY;
4713
4714 list_for_each_entry(pdev, &dev->bus->devices, bus_list)
4715 if (pdev != dev)
4716 return -ENOTTY;
4717
4718 if (probe)
4719 return 0;
4720
4721 return pci_bridge_secondary_bus_reset(dev->bus->self);
4722}
4723
4724static int pci_reset_hotplug_slot(struct hotplug_slot *hotplug, int probe)
4725{
4726 int rc = -ENOTTY;
4727
4728 if (!hotplug || !try_module_get(hotplug->owner))
4729 return rc;
4730
4731 if (hotplug->ops->reset_slot)
4732 rc = hotplug->ops->reset_slot(hotplug, probe);
4733
4734 module_put(hotplug->owner);
4735
4736 return rc;
4737}
4738
4739static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe)
4740{
4741 struct pci_dev *pdev;
4742
4743 if (dev->subordinate || !dev->slot ||
4744 dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)
4745 return -ENOTTY;
4746
4747 list_for_each_entry(pdev, &dev->bus->devices, bus_list)
4748 if (pdev != dev && pdev->slot == dev->slot)
4749 return -ENOTTY;
4750
4751 return pci_reset_hotplug_slot(dev->slot->hotplug, probe);
4752}
4753
4754static void pci_dev_lock(struct pci_dev *dev)
4755{
4756 pci_cfg_access_lock(dev);
4757 /* block PM suspend, driver probe, etc. */
4758 device_lock(&dev->dev);
4759}
4760
4761/* Return 1 on successful lock, 0 on contention */
4762static int pci_dev_trylock(struct pci_dev *dev)
4763{
4764 if (pci_cfg_access_trylock(dev)) {
4765 if (device_trylock(&dev->dev))
4766 return 1;
4767 pci_cfg_access_unlock(dev);
4768 }
4769
4770 return 0;
4771}
4772
4773static void pci_dev_unlock(struct pci_dev *dev)
4774{
4775 device_unlock(&dev->dev);
4776 pci_cfg_access_unlock(dev);
4777}
4778
4779static void pci_dev_save_and_disable(struct pci_dev *dev)
4780{
4781 const struct pci_error_handlers *err_handler =
4782 dev->driver ? dev->driver->err_handler : NULL;
4783
4784 /*
4785 * dev->driver->err_handler->reset_prepare() is protected against
4786 * races with ->remove() by the device lock, which must be held by
4787 * the caller.
4788 */
4789 if (err_handler && err_handler->reset_prepare)
4790 err_handler->reset_prepare(dev);
4791
4792 /*
4793 * Wake-up device prior to save. PM registers default to D0 after
4794 * reset and a simple register restore doesn't reliably return
4795 * to a non-D0 state anyway.
4796 */
4797 pci_set_power_state(dev, PCI_D0);
4798
4799 pci_save_state(dev);
4800 /*
4801 * Disable the device by clearing the Command register, except for
4802 * INTx-disable which is set. This not only disables MMIO and I/O port
4803 * BARs, but also prevents the device from being Bus Master, preventing
4804 * DMA from the device including MSI/MSI-X interrupts. For PCI 2.3
4805 * compliant devices, INTx-disable prevents legacy interrupts.
4806 */
4807 pci_write_config_word(dev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
4808}
4809
4810static void pci_dev_restore(struct pci_dev *dev)
4811{
4812 const struct pci_error_handlers *err_handler =
4813 dev->driver ? dev->driver->err_handler : NULL;
4814
4815 pci_restore_state(dev);
4816
4817 /*
4818 * dev->driver->err_handler->reset_done() is protected against
4819 * races with ->remove() by the device lock, which must be held by
4820 * the caller.
4821 */
4822 if (err_handler && err_handler->reset_done)
4823 err_handler->reset_done(dev);
4824}
4825
4826/**
4827 * __pci_reset_function_locked - reset a PCI device function while holding
4828 * the @dev mutex lock.
4829 * @dev: PCI device to reset
4830 *
4831 * Some devices allow an individual function to be reset without affecting
4832 * other functions in the same device. The PCI device must be responsive
4833 * to PCI config space in order to use this function.
4834 *
4835 * The device function is presumed to be unused and the caller is holding
4836 * the device mutex lock when this function is called.
4837 *
4838 * Resetting the device will make the contents of PCI configuration space
4839 * random, so any caller of this must be prepared to reinitialise the
4840 * device including MSI, bus mastering, BARs, decoding IO and memory spaces,
4841 * etc.
4842 *
4843 * Returns 0 if the device function was successfully reset or negative if the
4844 * device doesn't support resetting a single function.
4845 */
4846int __pci_reset_function_locked(struct pci_dev *dev)
4847{
4848 int rc;
4849
4850 might_sleep();
4851
4852 /*
4853 * A reset method returns -ENOTTY if it doesn't support this device
4854 * and we should try the next method.
4855 *
4856 * If it returns 0 (success), we're finished. If it returns any
4857 * other error, we're also finished: this indicates that further
4858 * reset mechanisms might be broken on the device.
4859 */
4860 rc = pci_dev_specific_reset(dev, 0);
4861 if (rc != -ENOTTY)
4862 return rc;
4863 if (pcie_has_flr(dev)) {
4864 rc = pcie_flr(dev);
4865 if (rc != -ENOTTY)
4866 return rc;
4867 }
4868 rc = pci_af_flr(dev, 0);
4869 if (rc != -ENOTTY)
4870 return rc;
4871 rc = pci_pm_reset(dev, 0);
4872 if (rc != -ENOTTY)
4873 return rc;
4874 rc = pci_dev_reset_slot_function(dev, 0);
4875 if (rc != -ENOTTY)
4876 return rc;
4877 return pci_parent_bus_reset(dev, 0);
4878}
4879EXPORT_SYMBOL_GPL(__pci_reset_function_locked);
4880
4881/**
4882 * pci_probe_reset_function - check whether the device can be safely reset
4883 * @dev: PCI device to reset
4884 *
4885 * Some devices allow an individual function to be reset without affecting
4886 * other functions in the same device. The PCI device must be responsive
4887 * to PCI config space in order to use this function.
4888 *
4889 * Returns 0 if the device function can be reset or negative if the
4890 * device doesn't support resetting a single function.
4891 */
4892int pci_probe_reset_function(struct pci_dev *dev)
4893{
4894 int rc;
4895
4896 might_sleep();
4897
4898 rc = pci_dev_specific_reset(dev, 1);
4899 if (rc != -ENOTTY)
4900 return rc;
4901 if (pcie_has_flr(dev))
4902 return 0;
4903 rc = pci_af_flr(dev, 1);
4904 if (rc != -ENOTTY)
4905 return rc;
4906 rc = pci_pm_reset(dev, 1);
4907 if (rc != -ENOTTY)
4908 return rc;
4909 rc = pci_dev_reset_slot_function(dev, 1);
4910 if (rc != -ENOTTY)
4911 return rc;
4912
4913 return pci_parent_bus_reset(dev, 1);
4914}
4915
4916/**
4917 * pci_reset_function - quiesce and reset a PCI device function
4918 * @dev: PCI device to reset
4919 *
4920 * Some devices allow an individual function to be reset without affecting
4921 * other functions in the same device. The PCI device must be responsive
4922 * to PCI config space in order to use this function.
4923 *
4924 * This function does not just reset the PCI portion of a device, but
4925 * clears all the state associated with the device. This function differs
4926 * from __pci_reset_function_locked() in that it saves and restores device state
4927 * over the reset and takes the PCI device lock.
4928 *
4929 * Returns 0 if the device function was successfully reset or negative if the
4930 * device doesn't support resetting a single function.
4931 */
4932int pci_reset_function(struct pci_dev *dev)
4933{
4934 int rc;
4935
4936 if (!dev->reset_fn)
4937 return -ENOTTY;
4938
4939 pci_dev_lock(dev);
4940 pci_dev_save_and_disable(dev);
4941
4942 rc = __pci_reset_function_locked(dev);
4943
4944 pci_dev_restore(dev);
4945 pci_dev_unlock(dev);
4946
4947 return rc;
4948}
4949EXPORT_SYMBOL_GPL(pci_reset_function);
4950
4951/**
4952 * pci_reset_function_locked - quiesce and reset a PCI device function
4953 * @dev: PCI device to reset
4954 *
4955 * Some devices allow an individual function to be reset without affecting
4956 * other functions in the same device. The PCI device must be responsive
4957 * to PCI config space in order to use this function.
4958 *
4959 * This function does not just reset the PCI portion of a device, but
4960 * clears all the state associated with the device. This function differs
4961 * from __pci_reset_function_locked() in that it saves and restores device state
4962 * over the reset. It also differs from pci_reset_function() in that it
4963 * requires the PCI device lock to be held.
4964 *
4965 * Returns 0 if the device function was successfully reset or negative if the
4966 * device doesn't support resetting a single function.
4967 */
4968int pci_reset_function_locked(struct pci_dev *dev)
4969{
4970 int rc;
4971
4972 if (!dev->reset_fn)
4973 return -ENOTTY;
4974
4975 pci_dev_save_and_disable(dev);
4976
4977 rc = __pci_reset_function_locked(dev);
4978
4979 pci_dev_restore(dev);
4980
4981 return rc;
4982}
4983EXPORT_SYMBOL_GPL(pci_reset_function_locked);
4984
4985/**
4986 * pci_try_reset_function - quiesce and reset a PCI device function
4987 * @dev: PCI device to reset
4988 *
4989 * Same as above, except return -EAGAIN if unable to lock device.
4990 */
4991int pci_try_reset_function(struct pci_dev *dev)
4992{
4993 int rc;
4994
4995 if (!dev->reset_fn)
4996 return -ENOTTY;
4997
4998 if (!pci_dev_trylock(dev))
4999 return -EAGAIN;
5000
5001 pci_dev_save_and_disable(dev);
5002 rc = __pci_reset_function_locked(dev);
5003 pci_dev_restore(dev);
5004 pci_dev_unlock(dev);
5005
5006 return rc;
5007}
5008EXPORT_SYMBOL_GPL(pci_try_reset_function);
5009
5010/* Do any devices on or below this bus prevent a bus reset? */
5011static bool pci_bus_resetable(struct pci_bus *bus)
5012{
5013 struct pci_dev *dev;
5014
5015
5016 if (bus->self && (bus->self->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET))
5017 return false;
5018
5019 list_for_each_entry(dev, &bus->devices, bus_list) {
5020 if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET ||
5021 (dev->subordinate && !pci_bus_resetable(dev->subordinate)))
5022 return false;
5023 }
5024
5025 return true;
5026}
5027
5028/* Lock devices from the top of the tree down */
5029static void pci_bus_lock(struct pci_bus *bus)
5030{
5031 struct pci_dev *dev;
5032
5033 list_for_each_entry(dev, &bus->devices, bus_list) {
5034 pci_dev_lock(dev);
5035 if (dev->subordinate)
5036 pci_bus_lock(dev->subordinate);
5037 }
5038}
5039
5040/* Unlock devices from the bottom of the tree up */
5041static void pci_bus_unlock(struct pci_bus *bus)
5042{
5043 struct pci_dev *dev;
5044
5045 list_for_each_entry(dev, &bus->devices, bus_list) {
5046 if (dev->subordinate)
5047 pci_bus_unlock(dev->subordinate);
5048 pci_dev_unlock(dev);
5049 }
5050}
5051
5052/* Return 1 on successful lock, 0 on contention */
5053static int pci_bus_trylock(struct pci_bus *bus)
5054{
5055 struct pci_dev *dev;
5056
5057 list_for_each_entry(dev, &bus->devices, bus_list) {
5058 if (!pci_dev_trylock(dev))
5059 goto unlock;
5060 if (dev->subordinate) {
5061 if (!pci_bus_trylock(dev->subordinate)) {
5062 pci_dev_unlock(dev);
5063 goto unlock;
5064 }
5065 }
5066 }
5067 return 1;
5068
5069unlock:
5070 list_for_each_entry_continue_reverse(dev, &bus->devices, bus_list) {
5071 if (dev->subordinate)
5072 pci_bus_unlock(dev->subordinate);
5073 pci_dev_unlock(dev);
5074 }
5075 return 0;
5076}
5077
5078/* Do any devices on or below this slot prevent a bus reset? */
5079static bool pci_slot_resetable(struct pci_slot *slot)
5080{
5081 struct pci_dev *dev;
5082
5083 if (slot->bus->self &&
5084 (slot->bus->self->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET))
5085 return false;
5086
5087 list_for_each_entry(dev, &slot->bus->devices, bus_list) {
5088 if (!dev->slot || dev->slot != slot)
5089 continue;
5090 if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET ||
5091 (dev->subordinate && !pci_bus_resetable(dev->subordinate)))
5092 return false;
5093 }
5094
5095 return true;
5096}
5097
5098/* Lock devices from the top of the tree down */
5099static void pci_slot_lock(struct pci_slot *slot)
5100{
5101 struct pci_dev *dev;
5102
5103 list_for_each_entry(dev, &slot->bus->devices, bus_list) {
5104 if (!dev->slot || dev->slot != slot)
5105 continue;
5106 pci_dev_lock(dev);
5107 if (dev->subordinate)
5108 pci_bus_lock(dev->subordinate);
5109 }
5110}
5111
5112/* Unlock devices from the bottom of the tree up */
5113static void pci_slot_unlock(struct pci_slot *slot)
5114{
5115 struct pci_dev *dev;
5116
5117 list_for_each_entry(dev, &slot->bus->devices, bus_list) {
5118 if (!dev->slot || dev->slot != slot)
5119 continue;
5120 if (dev->subordinate)
5121 pci_bus_unlock(dev->subordinate);
5122 pci_dev_unlock(dev);
5123 }
5124}
5125
5126/* Return 1 on successful lock, 0 on contention */
5127static int pci_slot_trylock(struct pci_slot *slot)
5128{
5129 struct pci_dev *dev;
5130
5131 list_for_each_entry(dev, &slot->bus->devices, bus_list) {
5132 if (!dev->slot || dev->slot != slot)
5133 continue;
5134 if (!pci_dev_trylock(dev))
5135 goto unlock;
5136 if (dev->subordinate) {
5137 if (!pci_bus_trylock(dev->subordinate)) {
5138 pci_dev_unlock(dev);
5139 goto unlock;
5140 }
5141 }
5142 }
5143 return 1;
5144
5145unlock:
5146 list_for_each_entry_continue_reverse(dev,
5147 &slot->bus->devices, bus_list) {
5148 if (!dev->slot || dev->slot != slot)
5149 continue;
5150 if (dev->subordinate)
5151 pci_bus_unlock(dev->subordinate);
5152 pci_dev_unlock(dev);
5153 }
5154 return 0;
5155}
5156
5157/*
5158 * Save and disable devices from the top of the tree down while holding
5159 * the @dev mutex lock for the entire tree.
5160 */
5161static void pci_bus_save_and_disable_locked(struct pci_bus *bus)
5162{
5163 struct pci_dev *dev;
5164
5165 list_for_each_entry(dev, &bus->devices, bus_list) {
5166 pci_dev_save_and_disable(dev);
5167 if (dev->subordinate)
5168 pci_bus_save_and_disable_locked(dev->subordinate);
5169 }
5170}
5171
5172/*
5173 * Restore devices from top of the tree down while holding @dev mutex lock
5174 * for the entire tree. Parent bridges need to be restored before we can
5175 * get to subordinate devices.
5176 */
5177static void pci_bus_restore_locked(struct pci_bus *bus)
5178{
5179 struct pci_dev *dev;
5180
5181 list_for_each_entry(dev, &bus->devices, bus_list) {
5182 pci_dev_restore(dev);
5183 if (dev->subordinate)
5184 pci_bus_restore_locked(dev->subordinate);
5185 }
5186}
5187
5188/*
5189 * Save and disable devices from the top of the tree down while holding
5190 * the @dev mutex lock for the entire tree.
5191 */
5192static void pci_slot_save_and_disable_locked(struct pci_slot *slot)
5193{
5194 struct pci_dev *dev;
5195
5196 list_for_each_entry(dev, &slot->bus->devices, bus_list) {
5197 if (!dev->slot || dev->slot != slot)
5198 continue;
5199 pci_dev_save_and_disable(dev);
5200 if (dev->subordinate)
5201 pci_bus_save_and_disable_locked(dev->subordinate);
5202 }
5203}
5204
5205/*
5206 * Restore devices from top of the tree down while holding @dev mutex lock
5207 * for the entire tree. Parent bridges need to be restored before we can
5208 * get to subordinate devices.
5209 */
5210static void pci_slot_restore_locked(struct pci_slot *slot)
5211{
5212 struct pci_dev *dev;
5213
5214 list_for_each_entry(dev, &slot->bus->devices, bus_list) {
5215 if (!dev->slot || dev->slot != slot)
5216 continue;
5217 pci_dev_restore(dev);
5218 if (dev->subordinate)
5219 pci_bus_restore_locked(dev->subordinate);
5220 }
5221}
5222
5223static int pci_slot_reset(struct pci_slot *slot, int probe)
5224{
5225 int rc;
5226
5227 if (!slot || !pci_slot_resetable(slot))
5228 return -ENOTTY;
5229
5230 if (!probe)
5231 pci_slot_lock(slot);
5232
5233 might_sleep();
5234
5235 rc = pci_reset_hotplug_slot(slot->hotplug, probe);
5236
5237 if (!probe)
5238 pci_slot_unlock(slot);
5239
5240 return rc;
5241}
5242
5243/**
5244 * pci_probe_reset_slot - probe whether a PCI slot can be reset
5245 * @slot: PCI slot to probe
5246 *
5247 * Return 0 if slot can be reset, negative if a slot reset is not supported.
5248 */
5249int pci_probe_reset_slot(struct pci_slot *slot)
5250{
5251 return pci_slot_reset(slot, 1);
5252}
5253EXPORT_SYMBOL_GPL(pci_probe_reset_slot);
5254
5255/**
5256 * __pci_reset_slot - Try to reset a PCI slot
5257 * @slot: PCI slot to reset
5258 *
5259 * A PCI bus may host multiple slots, each slot may support a reset mechanism
5260 * independent of other slots. For instance, some slots may support slot power
5261 * control. In the case of a 1:1 bus to slot architecture, this function may
5262 * wrap the bus reset to avoid spurious slot related events such as hotplug.
5263 * Generally a slot reset should be attempted before a bus reset. All of the
5264 * function of the slot and any subordinate buses behind the slot are reset
5265 * through this function. PCI config space of all devices in the slot and
5266 * behind the slot is saved before and restored after reset.
5267 *
5268 * Same as above except return -EAGAIN if the slot cannot be locked
5269 */
5270static int __pci_reset_slot(struct pci_slot *slot)
5271{
5272 int rc;
5273
5274 rc = pci_slot_reset(slot, 1);
5275 if (rc)
5276 return rc;
5277
5278 if (pci_slot_trylock(slot)) {
5279 pci_slot_save_and_disable_locked(slot);
5280 might_sleep();
5281 rc = pci_reset_hotplug_slot(slot->hotplug, 0);
5282 pci_slot_restore_locked(slot);
5283 pci_slot_unlock(slot);
5284 } else
5285 rc = -EAGAIN;
5286
5287 return rc;
5288}
5289
5290static int pci_bus_reset(struct pci_bus *bus, int probe)
5291{
5292 int ret;
5293
5294 if (!bus->self || !pci_bus_resetable(bus))
5295 return -ENOTTY;
5296
5297 if (probe)
5298 return 0;
5299
5300 pci_bus_lock(bus);
5301
5302 might_sleep();
5303
5304 ret = pci_bridge_secondary_bus_reset(bus->self);
5305
5306 pci_bus_unlock(bus);
5307
5308 return ret;
5309}
5310
5311/**
5312 * pci_bus_error_reset - reset the bridge's subordinate bus
5313 * @bridge: The parent device that connects to the bus to reset
5314 *
5315 * This function will first try to reset the slots on this bus if the method is
5316 * available. If slot reset fails or is not available, this will fall back to a
5317 * secondary bus reset.
5318 */
5319int pci_bus_error_reset(struct pci_dev *bridge)
5320{
5321 struct pci_bus *bus = bridge->subordinate;
5322 struct pci_slot *slot;
5323
5324 if (!bus)
5325 return -ENOTTY;
5326
5327 mutex_lock(&pci_slot_mutex);
5328 if (list_empty(&bus->slots))
5329 goto bus_reset;
5330
5331 list_for_each_entry(slot, &bus->slots, list)
5332 if (pci_probe_reset_slot(slot))
5333 goto bus_reset;
5334
5335 list_for_each_entry(slot, &bus->slots, list)
5336 if (pci_slot_reset(slot, 0))
5337 goto bus_reset;
5338
5339 mutex_unlock(&pci_slot_mutex);
5340 return 0;
5341bus_reset:
5342 mutex_unlock(&pci_slot_mutex);
5343 return pci_bus_reset(bridge->subordinate, 0);
5344}
5345
5346/**
5347 * pci_probe_reset_bus - probe whether a PCI bus can be reset
5348 * @bus: PCI bus to probe
5349 *
5350 * Return 0 if bus can be reset, negative if a bus reset is not supported.
5351 */
5352int pci_probe_reset_bus(struct pci_bus *bus)
5353{
5354 return pci_bus_reset(bus, 1);
5355}
5356EXPORT_SYMBOL_GPL(pci_probe_reset_bus);
5357
5358/**
5359 * __pci_reset_bus - Try to reset a PCI bus
5360 * @bus: top level PCI bus to reset
5361 *
5362 * Same as above except return -EAGAIN if the bus cannot be locked
5363 */
5364static int __pci_reset_bus(struct pci_bus *bus)
5365{
5366 int rc;
5367
5368 rc = pci_bus_reset(bus, 1);
5369 if (rc)
5370 return rc;
5371
5372 if (pci_bus_trylock(bus)) {
5373 pci_bus_save_and_disable_locked(bus);
5374 might_sleep();
5375 rc = pci_bridge_secondary_bus_reset(bus->self);
5376 pci_bus_restore_locked(bus);
5377 pci_bus_unlock(bus);
5378 } else
5379 rc = -EAGAIN;
5380
5381 return rc;
5382}
5383
5384/**
5385 * pci_reset_bus - Try to reset a PCI bus
5386 * @pdev: top level PCI device to reset via slot/bus
5387 *
5388 * Same as above except return -EAGAIN if the bus cannot be locked
5389 */
5390int pci_reset_bus(struct pci_dev *pdev)
5391{
5392 return (!pci_probe_reset_slot(pdev->slot)) ?
5393 __pci_reset_slot(pdev->slot) : __pci_reset_bus(pdev->bus);
5394}
5395EXPORT_SYMBOL_GPL(pci_reset_bus);
5396
5397/**
5398 * pcix_get_max_mmrbc - get PCI-X maximum designed memory read byte count
5399 * @dev: PCI device to query
5400 *
5401 * Returns mmrbc: maximum designed memory read count in bytes or
5402 * appropriate error value.
5403 */
5404int pcix_get_max_mmrbc(struct pci_dev *dev)
5405{
5406 int cap;
5407 u32 stat;
5408
5409 cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
5410 if (!cap)
5411 return -EINVAL;
5412
5413 if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat))
5414 return -EINVAL;
5415
5416 return 512 << ((stat & PCI_X_STATUS_MAX_READ) >> 21);
5417}
5418EXPORT_SYMBOL(pcix_get_max_mmrbc);
5419
5420/**
5421 * pcix_get_mmrbc - get PCI-X maximum memory read byte count
5422 * @dev: PCI device to query
5423 *
5424 * Returns mmrbc: maximum memory read count in bytes or appropriate error
5425 * value.
5426 */
5427int pcix_get_mmrbc(struct pci_dev *dev)
5428{
5429 int cap;
5430 u16 cmd;
5431
5432 cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
5433 if (!cap)
5434 return -EINVAL;
5435
5436 if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd))
5437 return -EINVAL;
5438
5439 return 512 << ((cmd & PCI_X_CMD_MAX_READ) >> 2);
5440}
5441EXPORT_SYMBOL(pcix_get_mmrbc);
5442
5443/**
5444 * pcix_set_mmrbc - set PCI-X maximum memory read byte count
5445 * @dev: PCI device to query
5446 * @mmrbc: maximum memory read count in bytes
5447 * valid values are 512, 1024, 2048, 4096
5448 *
5449 * If possible sets maximum memory read byte count, some bridges have errata
5450 * that prevent this.
5451 */
5452int pcix_set_mmrbc(struct pci_dev *dev, int mmrbc)
5453{
5454 int cap;
5455 u32 stat, v, o;
5456 u16 cmd;
5457
5458 if (mmrbc < 512 || mmrbc > 4096 || !is_power_of_2(mmrbc))
5459 return -EINVAL;
5460
5461 v = ffs(mmrbc) - 10;
5462
5463 cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
5464 if (!cap)
5465 return -EINVAL;
5466
5467 if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat))
5468 return -EINVAL;
5469
5470 if (v > (stat & PCI_X_STATUS_MAX_READ) >> 21)
5471 return -E2BIG;
5472
5473 if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd))
5474 return -EINVAL;
5475
5476 o = (cmd & PCI_X_CMD_MAX_READ) >> 2;
5477 if (o != v) {
5478 if (v > o && (dev->bus->bus_flags & PCI_BUS_FLAGS_NO_MMRBC))
5479 return -EIO;
5480
5481 cmd &= ~PCI_X_CMD_MAX_READ;
5482 cmd |= v << 2;
5483 if (pci_write_config_word(dev, cap + PCI_X_CMD, cmd))
5484 return -EIO;
5485 }
5486 return 0;
5487}
5488EXPORT_SYMBOL(pcix_set_mmrbc);
5489
5490/**
5491 * pcie_get_readrq - get PCI Express read request size
5492 * @dev: PCI device to query
5493 *
5494 * Returns maximum memory read request in bytes or appropriate error value.
5495 */
5496int pcie_get_readrq(struct pci_dev *dev)
5497{
5498 u16 ctl;
5499
5500 pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl);
5501
5502 return 128 << ((ctl & PCI_EXP_DEVCTL_READRQ) >> 12);
5503}
5504EXPORT_SYMBOL(pcie_get_readrq);
5505
5506/**
5507 * pcie_set_readrq - set PCI Express maximum memory read request
5508 * @dev: PCI device to query
5509 * @rq: maximum memory read count in bytes
5510 * valid values are 128, 256, 512, 1024, 2048, 4096
5511 *
5512 * If possible sets maximum memory read request in bytes
5513 */
5514int pcie_set_readrq(struct pci_dev *dev, int rq)
5515{
5516 u16 v;
5517
5518 if (rq < 128 || rq > 4096 || !is_power_of_2(rq))
5519 return -EINVAL;
5520
5521 /*
5522 * If using the "performance" PCIe config, we clamp the read rq
5523 * size to the max packet size to keep the host bridge from
5524 * generating requests larger than we can cope with.
5525 */
5526 if (pcie_bus_config == PCIE_BUS_PERFORMANCE) {
5527 int mps = pcie_get_mps(dev);
5528
5529 if (mps < rq)
5530 rq = mps;
5531 }
5532
5533 v = (ffs(rq) - 8) << 12;
5534
5535 return pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
5536 PCI_EXP_DEVCTL_READRQ, v);
5537}
5538EXPORT_SYMBOL(pcie_set_readrq);
5539
5540/**
5541 * pcie_get_mps - get PCI Express maximum payload size
5542 * @dev: PCI device to query
5543 *
5544 * Returns maximum payload size in bytes
5545 */
5546int pcie_get_mps(struct pci_dev *dev)
5547{
5548 u16 ctl;
5549
5550 pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl);
5551
5552 return 128 << ((ctl & PCI_EXP_DEVCTL_PAYLOAD) >> 5);
5553}
5554EXPORT_SYMBOL(pcie_get_mps);
5555
5556/**
5557 * pcie_set_mps - set PCI Express maximum payload size
5558 * @dev: PCI device to query
5559 * @mps: maximum payload size in bytes
5560 * valid values are 128, 256, 512, 1024, 2048, 4096
5561 *
5562 * If possible sets maximum payload size
5563 */
5564int pcie_set_mps(struct pci_dev *dev, int mps)
5565{
5566 u16 v;
5567
5568 if (mps < 128 || mps > 4096 || !is_power_of_2(mps))
5569 return -EINVAL;
5570
5571 v = ffs(mps) - 8;
5572 if (v > dev->pcie_mpss)
5573 return -EINVAL;
5574 v <<= 5;
5575
5576 return pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
5577 PCI_EXP_DEVCTL_PAYLOAD, v);
5578}
5579EXPORT_SYMBOL(pcie_set_mps);
5580
5581/**
5582 * pcie_bandwidth_available - determine minimum link settings of a PCIe
5583 * device and its bandwidth limitation
5584 * @dev: PCI device to query
5585 * @limiting_dev: storage for device causing the bandwidth limitation
5586 * @speed: storage for speed of limiting device
5587 * @width: storage for width of limiting device
5588 *
5589 * Walk up the PCI device chain and find the point where the minimum
5590 * bandwidth is available. Return the bandwidth available there and (if
5591 * limiting_dev, speed, and width pointers are supplied) information about
5592 * that point. The bandwidth returned is in Mb/s, i.e., megabits/second of
5593 * raw bandwidth.
5594 */
5595u32 pcie_bandwidth_available(struct pci_dev *dev, struct pci_dev **limiting_dev,
5596 enum pci_bus_speed *speed,
5597 enum pcie_link_width *width)
5598{
5599 u16 lnksta;
5600 enum pci_bus_speed next_speed;
5601 enum pcie_link_width next_width;
5602 u32 bw, next_bw;
5603
5604 if (speed)
5605 *speed = PCI_SPEED_UNKNOWN;
5606 if (width)
5607 *width = PCIE_LNK_WIDTH_UNKNOWN;
5608
5609 bw = 0;
5610
5611 while (dev) {
5612 pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta);
5613
5614 next_speed = pcie_link_speed[lnksta & PCI_EXP_LNKSTA_CLS];
5615 next_width = (lnksta & PCI_EXP_LNKSTA_NLW) >>
5616 PCI_EXP_LNKSTA_NLW_SHIFT;
5617
5618 next_bw = next_width * PCIE_SPEED2MBS_ENC(next_speed);
5619
5620 /* Check if current device limits the total bandwidth */
5621 if (!bw || next_bw <= bw) {
5622 bw = next_bw;
5623
5624 if (limiting_dev)
5625 *limiting_dev = dev;
5626 if (speed)
5627 *speed = next_speed;
5628 if (width)
5629 *width = next_width;
5630 }
5631
5632 dev = pci_upstream_bridge(dev);
5633 }
5634
5635 return bw;
5636}
5637EXPORT_SYMBOL(pcie_bandwidth_available);
5638
5639/**
5640 * pcie_get_speed_cap - query for the PCI device's link speed capability
5641 * @dev: PCI device to query
5642 *
5643 * Query the PCI device speed capability. Return the maximum link speed
5644 * supported by the device.
5645 */
5646enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev)
5647{
5648 u32 lnkcap2, lnkcap;
5649
5650 /*
5651 * Link Capabilities 2 was added in PCIe r3.0, sec 7.8.18. The
5652 * implementation note there recommends using the Supported Link
5653 * Speeds Vector in Link Capabilities 2 when supported.
5654 *
5655 * Without Link Capabilities 2, i.e., prior to PCIe r3.0, software
5656 * should use the Supported Link Speeds field in Link Capabilities,
5657 * where only 2.5 GT/s and 5.0 GT/s speeds were defined.
5658 */
5659 pcie_capability_read_dword(dev, PCI_EXP_LNKCAP2, &lnkcap2);
5660 if (lnkcap2) { /* PCIe r3.0-compliant */
5661 if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_32_0GB)
5662 return PCIE_SPEED_32_0GT;
5663 else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_16_0GB)
5664 return PCIE_SPEED_16_0GT;
5665 else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_8_0GB)
5666 return PCIE_SPEED_8_0GT;
5667 else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_5_0GB)
5668 return PCIE_SPEED_5_0GT;
5669 else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_2_5GB)
5670 return PCIE_SPEED_2_5GT;
5671 return PCI_SPEED_UNKNOWN;
5672 }
5673
5674 pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap);
5675 if ((lnkcap & PCI_EXP_LNKCAP_SLS) == PCI_EXP_LNKCAP_SLS_5_0GB)
5676 return PCIE_SPEED_5_0GT;
5677 else if ((lnkcap & PCI_EXP_LNKCAP_SLS) == PCI_EXP_LNKCAP_SLS_2_5GB)
5678 return PCIE_SPEED_2_5GT;
5679
5680 return PCI_SPEED_UNKNOWN;
5681}
5682EXPORT_SYMBOL(pcie_get_speed_cap);
5683
5684/**
5685 * pcie_get_width_cap - query for the PCI device's link width capability
5686 * @dev: PCI device to query
5687 *
5688 * Query the PCI device width capability. Return the maximum link width
5689 * supported by the device.
5690 */
5691enum pcie_link_width pcie_get_width_cap(struct pci_dev *dev)
5692{
5693 u32 lnkcap;
5694
5695 pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap);
5696 if (lnkcap)
5697 return (lnkcap & PCI_EXP_LNKCAP_MLW) >> 4;
5698
5699 return PCIE_LNK_WIDTH_UNKNOWN;
5700}
5701EXPORT_SYMBOL(pcie_get_width_cap);
5702
5703/**
5704 * pcie_bandwidth_capable - calculate a PCI device's link bandwidth capability
5705 * @dev: PCI device
5706 * @speed: storage for link speed
5707 * @width: storage for link width
5708 *
5709 * Calculate a PCI device's link bandwidth by querying for its link speed
5710 * and width, multiplying them, and applying encoding overhead. The result
5711 * is in Mb/s, i.e., megabits/second of raw bandwidth.
5712 */
5713u32 pcie_bandwidth_capable(struct pci_dev *dev, enum pci_bus_speed *speed,
5714 enum pcie_link_width *width)
5715{
5716 *speed = pcie_get_speed_cap(dev);
5717 *width = pcie_get_width_cap(dev);
5718
5719 if (*speed == PCI_SPEED_UNKNOWN || *width == PCIE_LNK_WIDTH_UNKNOWN)
5720 return 0;
5721
5722 return *width * PCIE_SPEED2MBS_ENC(*speed);
5723}
5724
5725/**
5726 * __pcie_print_link_status - Report the PCI device's link speed and width
5727 * @dev: PCI device to query
5728 * @verbose: Print info even when enough bandwidth is available
5729 *
5730 * If the available bandwidth at the device is less than the device is
5731 * capable of, report the device's maximum possible bandwidth and the
5732 * upstream link that limits its performance. If @verbose, always print
5733 * the available bandwidth, even if the device isn't constrained.
5734 */
5735void __pcie_print_link_status(struct pci_dev *dev, bool verbose)
5736{
5737 enum pcie_link_width width, width_cap;
5738 enum pci_bus_speed speed, speed_cap;
5739 struct pci_dev *limiting_dev = NULL;
5740 u32 bw_avail, bw_cap;
5741
5742 bw_cap = pcie_bandwidth_capable(dev, &speed_cap, &width_cap);
5743 bw_avail = pcie_bandwidth_available(dev, &limiting_dev, &speed, &width);
5744
5745 if (bw_avail >= bw_cap && verbose)
5746 pci_info(dev, "%u.%03u Gb/s available PCIe bandwidth (%s x%d link)\n",
5747 bw_cap / 1000, bw_cap % 1000,
5748 PCIE_SPEED2STR(speed_cap), width_cap);
5749 else if (bw_avail < bw_cap)
5750 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",
5751 bw_avail / 1000, bw_avail % 1000,
5752 PCIE_SPEED2STR(speed), width,
5753 limiting_dev ? pci_name(limiting_dev) : "<unknown>",
5754 bw_cap / 1000, bw_cap % 1000,
5755 PCIE_SPEED2STR(speed_cap), width_cap);
5756}
5757
5758/**
5759 * pcie_print_link_status - Report the PCI device's link speed and width
5760 * @dev: PCI device to query
5761 *
5762 * Report the available bandwidth at the device.
5763 */
5764void pcie_print_link_status(struct pci_dev *dev)
5765{
5766 __pcie_print_link_status(dev, true);
5767}
5768EXPORT_SYMBOL(pcie_print_link_status);
5769
5770/**
5771 * pci_select_bars - Make BAR mask from the type of resource
5772 * @dev: the PCI device for which BAR mask is made
5773 * @flags: resource type mask to be selected
5774 *
5775 * This helper routine makes bar mask from the type of resource.
5776 */
5777int pci_select_bars(struct pci_dev *dev, unsigned long flags)
5778{
5779 int i, bars = 0;
5780 for (i = 0; i < PCI_NUM_RESOURCES; i++)
5781 if (pci_resource_flags(dev, i) & flags)
5782 bars |= (1 << i);
5783 return bars;
5784}
5785EXPORT_SYMBOL(pci_select_bars);
5786
5787/* Some architectures require additional programming to enable VGA */
5788static arch_set_vga_state_t arch_set_vga_state;
5789
5790void __init pci_register_set_vga_state(arch_set_vga_state_t func)
5791{
5792 arch_set_vga_state = func; /* NULL disables */
5793}
5794
5795static int pci_set_vga_state_arch(struct pci_dev *dev, bool decode,
5796 unsigned int command_bits, u32 flags)
5797{
5798 if (arch_set_vga_state)
5799 return arch_set_vga_state(dev, decode, command_bits,
5800 flags);
5801 return 0;
5802}
5803
5804/**
5805 * pci_set_vga_state - set VGA decode state on device and parents if requested
5806 * @dev: the PCI device
5807 * @decode: true = enable decoding, false = disable decoding
5808 * @command_bits: PCI_COMMAND_IO and/or PCI_COMMAND_MEMORY
5809 * @flags: traverse ancestors and change bridges
5810 * CHANGE_BRIDGE_ONLY / CHANGE_BRIDGE
5811 */
5812int pci_set_vga_state(struct pci_dev *dev, bool decode,
5813 unsigned int command_bits, u32 flags)
5814{
5815 struct pci_bus *bus;
5816 struct pci_dev *bridge;
5817 u16 cmd;
5818 int rc;
5819
5820 WARN_ON((flags & PCI_VGA_STATE_CHANGE_DECODES) && (command_bits & ~(PCI_COMMAND_IO|PCI_COMMAND_MEMORY)));
5821
5822 /* ARCH specific VGA enables */
5823 rc = pci_set_vga_state_arch(dev, decode, command_bits, flags);
5824 if (rc)
5825 return rc;
5826
5827 if (flags & PCI_VGA_STATE_CHANGE_DECODES) {
5828 pci_read_config_word(dev, PCI_COMMAND, &cmd);
5829 if (decode == true)
5830 cmd |= command_bits;
5831 else
5832 cmd &= ~command_bits;
5833 pci_write_config_word(dev, PCI_COMMAND, cmd);
5834 }
5835
5836 if (!(flags & PCI_VGA_STATE_CHANGE_BRIDGE))
5837 return 0;
5838
5839 bus = dev->bus;
5840 while (bus) {
5841 bridge = bus->self;
5842 if (bridge) {
5843 pci_read_config_word(bridge, PCI_BRIDGE_CONTROL,
5844 &cmd);
5845 if (decode == true)
5846 cmd |= PCI_BRIDGE_CTL_VGA;
5847 else
5848 cmd &= ~PCI_BRIDGE_CTL_VGA;
5849 pci_write_config_word(bridge, PCI_BRIDGE_CONTROL,
5850 cmd);
5851 }
5852 bus = bus->parent;
5853 }
5854 return 0;
5855}
5856
5857/**
5858 * pci_add_dma_alias - Add a DMA devfn alias for a device
5859 * @dev: the PCI device for which alias is added
5860 * @devfn: alias slot and function
5861 *
5862 * This helper encodes an 8-bit devfn as a bit number in dma_alias_mask
5863 * which is used to program permissible bus-devfn source addresses for DMA
5864 * requests in an IOMMU. These aliases factor into IOMMU group creation
5865 * and are useful for devices generating DMA requests beyond or different
5866 * from their logical bus-devfn. Examples include device quirks where the
5867 * device simply uses the wrong devfn, as well as non-transparent bridges
5868 * where the alias may be a proxy for devices in another domain.
5869 *
5870 * IOMMU group creation is performed during device discovery or addition,
5871 * prior to any potential DMA mapping and therefore prior to driver probing
5872 * (especially for userspace assigned devices where IOMMU group definition
5873 * cannot be left as a userspace activity). DMA aliases should therefore
5874 * be configured via quirks, such as the PCI fixup header quirk.
5875 */
5876void pci_add_dma_alias(struct pci_dev *dev, u8 devfn)
5877{
5878 if (!dev->dma_alias_mask)
5879 dev->dma_alias_mask = bitmap_zalloc(U8_MAX, GFP_KERNEL);
5880 if (!dev->dma_alias_mask) {
5881 pci_warn(dev, "Unable to allocate DMA alias mask\n");
5882 return;
5883 }
5884
5885 set_bit(devfn, dev->dma_alias_mask);
5886 pci_info(dev, "Enabling fixed DMA alias to %02x.%d\n",
5887 PCI_SLOT(devfn), PCI_FUNC(devfn));
5888}
5889
5890bool pci_devs_are_dma_aliases(struct pci_dev *dev1, struct pci_dev *dev2)
5891{
5892 return (dev1->dma_alias_mask &&
5893 test_bit(dev2->devfn, dev1->dma_alias_mask)) ||
5894 (dev2->dma_alias_mask &&
5895 test_bit(dev1->devfn, dev2->dma_alias_mask));
5896}
5897
5898bool pci_device_is_present(struct pci_dev *pdev)
5899{
5900 u32 v;
5901
5902 if (pci_dev_is_disconnected(pdev))
5903 return false;
5904 return pci_bus_read_dev_vendor_id(pdev->bus, pdev->devfn, &v, 0);
5905}
5906EXPORT_SYMBOL_GPL(pci_device_is_present);
5907
5908void pci_ignore_hotplug(struct pci_dev *dev)
5909{
5910 struct pci_dev *bridge = dev->bus->self;
5911
5912 dev->ignore_hotplug = 1;
5913 /* Propagate the "ignore hotplug" setting to the parent bridge. */
5914 if (bridge)
5915 bridge->ignore_hotplug = 1;
5916}
5917EXPORT_SYMBOL_GPL(pci_ignore_hotplug);
5918
5919resource_size_t __weak pcibios_default_alignment(void)
5920{
5921 return 0;
5922}
5923
5924/*
5925 * Arches that don't want to expose struct resource to userland as-is in
5926 * sysfs and /proc can implement their own pci_resource_to_user().
5927 */
5928void __weak pci_resource_to_user(const struct pci_dev *dev, int bar,
5929 const struct resource *rsrc,
5930 resource_size_t *start, resource_size_t *end)
5931{
5932 *start = rsrc->start;
5933 *end = rsrc->end;
5934}
5935
5936static char *resource_alignment_param;
5937static DEFINE_SPINLOCK(resource_alignment_lock);
5938
5939/**
5940 * pci_specified_resource_alignment - get resource alignment specified by user.
5941 * @dev: the PCI device to get
5942 * @resize: whether or not to change resources' size when reassigning alignment
5943 *
5944 * RETURNS: Resource alignment if it is specified.
5945 * Zero if it is not specified.
5946 */
5947static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev,
5948 bool *resize)
5949{
5950 int align_order, count;
5951 resource_size_t align = pcibios_default_alignment();
5952 const char *p;
5953 int ret;
5954
5955 spin_lock(&resource_alignment_lock);
5956 p = resource_alignment_param;
5957 if (!p || !*p)
5958 goto out;
5959 if (pci_has_flag(PCI_PROBE_ONLY)) {
5960 align = 0;
5961 pr_info_once("PCI: Ignoring requested alignments (PCI_PROBE_ONLY)\n");
5962 goto out;
5963 }
5964
5965 while (*p) {
5966 count = 0;
5967 if (sscanf(p, "%d%n", &align_order, &count) == 1 &&
5968 p[count] == '@') {
5969 p += count + 1;
5970 } else {
5971 align_order = -1;
5972 }
5973
5974 ret = pci_dev_str_match(dev, p, &p);
5975 if (ret == 1) {
5976 *resize = true;
5977 if (align_order == -1)
5978 align = PAGE_SIZE;
5979 else
5980 align = 1 << align_order;
5981 break;
5982 } else if (ret < 0) {
5983 pr_err("PCI: Can't parse resource_alignment parameter: %s\n",
5984 p);
5985 break;
5986 }
5987
5988 if (*p != ';' && *p != ',') {
5989 /* End of param or invalid format */
5990 break;
5991 }
5992 p++;
5993 }
5994out:
5995 spin_unlock(&resource_alignment_lock);
5996 return align;
5997}
5998
5999static void pci_request_resource_alignment(struct pci_dev *dev, int bar,
6000 resource_size_t align, bool resize)
6001{
6002 struct resource *r = &dev->resource[bar];
6003 resource_size_t size;
6004
6005 if (!(r->flags & IORESOURCE_MEM))
6006 return;
6007
6008 if (r->flags & IORESOURCE_PCI_FIXED) {
6009 pci_info(dev, "BAR%d %pR: ignoring requested alignment %#llx\n",
6010 bar, r, (unsigned long long)align);
6011 return;
6012 }
6013
6014 size = resource_size(r);
6015 if (size >= align)
6016 return;
6017
6018 /*
6019 * Increase the alignment of the resource. There are two ways we
6020 * can do this:
6021 *
6022 * 1) Increase the size of the resource. BARs are aligned on their
6023 * size, so when we reallocate space for this resource, we'll
6024 * allocate it with the larger alignment. This also prevents
6025 * assignment of any other BARs inside the alignment region, so
6026 * if we're requesting page alignment, this means no other BARs
6027 * will share the page.
6028 *
6029 * The disadvantage is that this makes the resource larger than
6030 * the hardware BAR, which may break drivers that compute things
6031 * based on the resource size, e.g., to find registers at a
6032 * fixed offset before the end of the BAR.
6033 *
6034 * 2) Retain the resource size, but use IORESOURCE_STARTALIGN and
6035 * set r->start to the desired alignment. By itself this
6036 * doesn't prevent other BARs being put inside the alignment
6037 * region, but if we realign *every* resource of every device in
6038 * the system, none of them will share an alignment region.
6039 *
6040 * When the user has requested alignment for only some devices via
6041 * the "pci=resource_alignment" argument, "resize" is true and we
6042 * use the first method. Otherwise we assume we're aligning all
6043 * devices and we use the second.
6044 */
6045
6046 pci_info(dev, "BAR%d %pR: requesting alignment to %#llx\n",
6047 bar, r, (unsigned long long)align);
6048
6049 if (resize) {
6050 r->start = 0;
6051 r->end = align - 1;
6052 } else {
6053 r->flags &= ~IORESOURCE_SIZEALIGN;
6054 r->flags |= IORESOURCE_STARTALIGN;
6055 r->start = align;
6056 r->end = r->start + size - 1;
6057 }
6058 r->flags |= IORESOURCE_UNSET;
6059}
6060
6061/*
6062 * This function disables memory decoding and releases memory resources
6063 * of the device specified by kernel's boot parameter 'pci=resource_alignment='.
6064 * It also rounds up size to specified alignment.
6065 * Later on, the kernel will assign page-aligned memory resource back
6066 * to the device.
6067 */
6068void pci_reassigndev_resource_alignment(struct pci_dev *dev)
6069{
6070 int i;
6071 struct resource *r;
6072 resource_size_t align;
6073 u16 command;
6074 bool resize = false;
6075
6076 /*
6077 * VF BARs are read-only zero according to SR-IOV spec r1.1, sec
6078 * 3.4.1.11. Their resources are allocated from the space
6079 * described by the VF BARx register in the PF's SR-IOV capability.
6080 * We can't influence their alignment here.
6081 */
6082 if (dev->is_virtfn)
6083 return;
6084
6085 /* check if specified PCI is target device to reassign */
6086 align = pci_specified_resource_alignment(dev, &resize);
6087 if (!align)
6088 return;
6089
6090 if (dev->hdr_type == PCI_HEADER_TYPE_NORMAL &&
6091 (dev->class >> 8) == PCI_CLASS_BRIDGE_HOST) {
6092 pci_warn(dev, "Can't reassign resources to host bridge\n");
6093 return;
6094 }
6095
6096 pci_read_config_word(dev, PCI_COMMAND, &command);
6097 command &= ~PCI_COMMAND_MEMORY;
6098 pci_write_config_word(dev, PCI_COMMAND, command);
6099
6100 for (i = 0; i <= PCI_ROM_RESOURCE; i++)
6101 pci_request_resource_alignment(dev, i, align, resize);
6102
6103 /*
6104 * Need to disable bridge's resource window,
6105 * to enable the kernel to reassign new resource
6106 * window later on.
6107 */
6108 if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
6109 for (i = PCI_BRIDGE_RESOURCES; i < PCI_NUM_RESOURCES; i++) {
6110 r = &dev->resource[i];
6111 if (!(r->flags & IORESOURCE_MEM))
6112 continue;
6113 r->flags |= IORESOURCE_UNSET;
6114 r->end = resource_size(r) - 1;
6115 r->start = 0;
6116 }
6117 pci_disable_bridge_window(dev);
6118 }
6119}
6120
6121static ssize_t resource_alignment_show(struct bus_type *bus, char *buf)
6122{
6123 size_t count = 0;
6124
6125 spin_lock(&resource_alignment_lock);
6126 if (resource_alignment_param)
6127 count = snprintf(buf, PAGE_SIZE, "%s", resource_alignment_param);
6128 spin_unlock(&resource_alignment_lock);
6129
6130 /*
6131 * When set by the command line, resource_alignment_param will not
6132 * have a trailing line feed, which is ugly. So conditionally add
6133 * it here.
6134 */
6135 if (count >= 2 && buf[count - 2] != '\n' && count < PAGE_SIZE - 1) {
6136 buf[count - 1] = '\n';
6137 buf[count++] = 0;
6138 }
6139
6140 return count;
6141}
6142
6143static ssize_t resource_alignment_store(struct bus_type *bus,
6144 const char *buf, size_t count)
6145{
6146 char *param = kstrndup(buf, count, GFP_KERNEL);
6147
6148 if (!param)
6149 return -ENOMEM;
6150
6151 spin_lock(&resource_alignment_lock);
6152 kfree(resource_alignment_param);
6153 resource_alignment_param = param;
6154 spin_unlock(&resource_alignment_lock);
6155 return count;
6156}
6157
6158static BUS_ATTR_RW(resource_alignment);
6159
6160static int __init pci_resource_alignment_sysfs_init(void)
6161{
6162 return bus_create_file(&pci_bus_type,
6163 &bus_attr_resource_alignment);
6164}
6165late_initcall(pci_resource_alignment_sysfs_init);
6166
6167static void pci_no_domains(void)
6168{
6169#ifdef CONFIG_PCI_DOMAINS
6170 pci_domains_supported = 0;
6171#endif
6172}
6173
6174#ifdef CONFIG_PCI_DOMAINS_GENERIC
6175static atomic_t __domain_nr = ATOMIC_INIT(-1);
6176
6177static int pci_get_new_domain_nr(void)
6178{
6179 return atomic_inc_return(&__domain_nr);
6180}
6181
6182static int of_pci_bus_find_domain_nr(struct device *parent)
6183{
6184 static int use_dt_domains = -1;
6185 int domain = -1;
6186
6187 if (parent)
6188 domain = of_get_pci_domain_nr(parent->of_node);
6189
6190 /*
6191 * Check DT domain and use_dt_domains values.
6192 *
6193 * If DT domain property is valid (domain >= 0) and
6194 * use_dt_domains != 0, the DT assignment is valid since this means
6195 * we have not previously allocated a domain number by using
6196 * pci_get_new_domain_nr(); we should also update use_dt_domains to
6197 * 1, to indicate that we have just assigned a domain number from
6198 * DT.
6199 *
6200 * If DT domain property value is not valid (ie domain < 0), and we
6201 * have not previously assigned a domain number from DT
6202 * (use_dt_domains != 1) we should assign a domain number by
6203 * using the:
6204 *
6205 * pci_get_new_domain_nr()
6206 *
6207 * API and update the use_dt_domains value to keep track of method we
6208 * are using to assign domain numbers (use_dt_domains = 0).
6209 *
6210 * All other combinations imply we have a platform that is trying
6211 * to mix domain numbers obtained from DT and pci_get_new_domain_nr(),
6212 * which is a recipe for domain mishandling and it is prevented by
6213 * invalidating the domain value (domain = -1) and printing a
6214 * corresponding error.
6215 */
6216 if (domain >= 0 && use_dt_domains) {
6217 use_dt_domains = 1;
6218 } else if (domain < 0 && use_dt_domains != 1) {
6219 use_dt_domains = 0;
6220 domain = pci_get_new_domain_nr();
6221 } else {
6222 if (parent)
6223 pr_err("Node %pOF has ", parent->of_node);
6224 pr_err("Inconsistent \"linux,pci-domain\" property in DT\n");
6225 domain = -1;
6226 }
6227
6228 return domain;
6229}
6230
6231int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent)
6232{
6233 return acpi_disabled ? of_pci_bus_find_domain_nr(parent) :
6234 acpi_pci_bus_find_domain_nr(bus);
6235}
6236#endif
6237
6238/**
6239 * pci_ext_cfg_avail - can we access extended PCI config space?
6240 *
6241 * Returns 1 if we can access PCI extended config space (offsets
6242 * greater than 0xff). This is the default implementation. Architecture
6243 * implementations can override this.
6244 */
6245int __weak pci_ext_cfg_avail(void)
6246{
6247 return 1;
6248}
6249
6250void __weak pci_fixup_cardbus(struct pci_bus *bus)
6251{
6252}
6253EXPORT_SYMBOL(pci_fixup_cardbus);
6254
6255static int __init pci_setup(char *str)
6256{
6257 while (str) {
6258 char *k = strchr(str, ',');
6259 if (k)
6260 *k++ = 0;
6261 if (*str && (str = pcibios_setup(str)) && *str) {
6262 if (!strcmp(str, "nomsi")) {
6263 pci_no_msi();
6264 } else if (!strncmp(str, "noats", 5)) {
6265 pr_info("PCIe: ATS is disabled\n");
6266 pcie_ats_disabled = true;
6267 } else if (!strcmp(str, "noaer")) {
6268 pci_no_aer();
6269 } else if (!strcmp(str, "earlydump")) {
6270 pci_early_dump = true;
6271 } else if (!strncmp(str, "realloc=", 8)) {
6272 pci_realloc_get_opt(str + 8);
6273 } else if (!strncmp(str, "realloc", 7)) {
6274 pci_realloc_get_opt("on");
6275 } else if (!strcmp(str, "nodomains")) {
6276 pci_no_domains();
6277 } else if (!strncmp(str, "noari", 5)) {
6278 pcie_ari_disabled = true;
6279 } else if (!strncmp(str, "cbiosize=", 9)) {
6280 pci_cardbus_io_size = memparse(str + 9, &str);
6281 } else if (!strncmp(str, "cbmemsize=", 10)) {
6282 pci_cardbus_mem_size = memparse(str + 10, &str);
6283 } else if (!strncmp(str, "resource_alignment=", 19)) {
6284 resource_alignment_param = str + 19;
6285 } else if (!strncmp(str, "ecrc=", 5)) {
6286 pcie_ecrc_get_policy(str + 5);
6287 } else if (!strncmp(str, "hpiosize=", 9)) {
6288 pci_hotplug_io_size = memparse(str + 9, &str);
6289 } else if (!strncmp(str, "hpmemsize=", 10)) {
6290 pci_hotplug_mem_size = memparse(str + 10, &str);
6291 } else if (!strncmp(str, "hpbussize=", 10)) {
6292 pci_hotplug_bus_size =
6293 simple_strtoul(str + 10, &str, 0);
6294 if (pci_hotplug_bus_size > 0xff)
6295 pci_hotplug_bus_size = DEFAULT_HOTPLUG_BUS_SIZE;
6296 } else if (!strncmp(str, "pcie_bus_tune_off", 17)) {
6297 pcie_bus_config = PCIE_BUS_TUNE_OFF;
6298 } else if (!strncmp(str, "pcie_bus_safe", 13)) {
6299 pcie_bus_config = PCIE_BUS_SAFE;
6300 } else if (!strncmp(str, "pcie_bus_perf", 13)) {
6301 pcie_bus_config = PCIE_BUS_PERFORMANCE;
6302 } else if (!strncmp(str, "pcie_bus_peer2peer", 18)) {
6303 pcie_bus_config = PCIE_BUS_PEER2PEER;
6304 } else if (!strncmp(str, "pcie_scan_all", 13)) {
6305 pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS);
6306 } else if (!strncmp(str, "disable_acs_redir=", 18)) {
6307 disable_acs_redir_param = str + 18;
6308 } else {
6309 pr_err("PCI: Unknown option `%s'\n", str);
6310 }
6311 }
6312 str = k;
6313 }
6314 return 0;
6315}
6316early_param("pci", pci_setup);
6317
6318/*
6319 * 'resource_alignment_param' and 'disable_acs_redir_param' are initialized
6320 * in pci_setup(), above, to point to data in the __initdata section which
6321 * will be freed after the init sequence is complete. We can't allocate memory
6322 * in pci_setup() because some architectures do not have any memory allocation
6323 * service available during an early_param() call. So we allocate memory and
6324 * copy the variable here before the init section is freed.
6325 *
6326 */
6327static int __init pci_realloc_setup_params(void)
6328{
6329 resource_alignment_param = kstrdup(resource_alignment_param,
6330 GFP_KERNEL);
6331 disable_acs_redir_param = kstrdup(disable_acs_redir_param, GFP_KERNEL);
6332
6333 return 0;
6334}
6335pure_initcall(pci_realloc_setup_params);