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1/*
2 * PCI Bus Services, see include/linux/pci.h for further explanation.
3 *
4 * Copyright 1993 -- 1997 Drew Eckhardt, Frederic Potter,
5 * David Mosberger-Tang
6 *
7 * Copyright 1997 -- 2000 Martin Mares <mj@ucw.cz>
8 */
9
10#include <linux/kernel.h>
11#include <linux/delay.h>
12#include <linux/init.h>
13#include <linux/pci.h>
14#include <linux/pm.h>
15#include <linux/slab.h>
16#include <linux/module.h>
17#include <linux/spinlock.h>
18#include <linux/string.h>
19#include <linux/log2.h>
20#include <linux/pci-aspm.h>
21#include <linux/pm_wakeup.h>
22#include <linux/interrupt.h>
23#include <linux/device.h>
24#include <linux/pm_runtime.h>
25#include <asm/setup.h>
26#include "pci.h"
27
28const char *pci_power_names[] = {
29 "error", "D0", "D1", "D2", "D3hot", "D3cold", "unknown",
30};
31EXPORT_SYMBOL_GPL(pci_power_names);
32
33int isa_dma_bridge_buggy;
34EXPORT_SYMBOL(isa_dma_bridge_buggy);
35
36int pci_pci_problems;
37EXPORT_SYMBOL(pci_pci_problems);
38
39unsigned int pci_pm_d3_delay;
40
41static void pci_pme_list_scan(struct work_struct *work);
42
43static LIST_HEAD(pci_pme_list);
44static DEFINE_MUTEX(pci_pme_list_mutex);
45static DECLARE_DELAYED_WORK(pci_pme_work, pci_pme_list_scan);
46
47struct pci_pme_device {
48 struct list_head list;
49 struct pci_dev *dev;
50};
51
52#define PME_TIMEOUT 1000 /* How long between PME checks */
53
54static void pci_dev_d3_sleep(struct pci_dev *dev)
55{
56 unsigned int delay = dev->d3_delay;
57
58 if (delay < pci_pm_d3_delay)
59 delay = pci_pm_d3_delay;
60
61 msleep(delay);
62}
63
64#ifdef CONFIG_PCI_DOMAINS
65int pci_domains_supported = 1;
66#endif
67
68#define DEFAULT_CARDBUS_IO_SIZE (256)
69#define DEFAULT_CARDBUS_MEM_SIZE (64*1024*1024)
70/* pci=cbmemsize=nnM,cbiosize=nn can override this */
71unsigned long pci_cardbus_io_size = DEFAULT_CARDBUS_IO_SIZE;
72unsigned long pci_cardbus_mem_size = DEFAULT_CARDBUS_MEM_SIZE;
73
74#define DEFAULT_HOTPLUG_IO_SIZE (256)
75#define DEFAULT_HOTPLUG_MEM_SIZE (2*1024*1024)
76/* pci=hpmemsize=nnM,hpiosize=nn can override this */
77unsigned long pci_hotplug_io_size = DEFAULT_HOTPLUG_IO_SIZE;
78unsigned long pci_hotplug_mem_size = DEFAULT_HOTPLUG_MEM_SIZE;
79
80enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_TUNE_OFF;
81
82/*
83 * The default CLS is used if arch didn't set CLS explicitly and not
84 * all pci devices agree on the same value. Arch can override either
85 * the dfl or actual value as it sees fit. Don't forget this is
86 * measured in 32-bit words, not bytes.
87 */
88u8 pci_dfl_cache_line_size __devinitdata = L1_CACHE_BYTES >> 2;
89u8 pci_cache_line_size;
90
91/**
92 * pci_bus_max_busnr - returns maximum PCI bus number of given bus' children
93 * @bus: pointer to PCI bus structure to search
94 *
95 * Given a PCI bus, returns the highest PCI bus number present in the set
96 * including the given PCI bus and its list of child PCI buses.
97 */
98unsigned char pci_bus_max_busnr(struct pci_bus* bus)
99{
100 struct list_head *tmp;
101 unsigned char max, n;
102
103 max = bus->subordinate;
104 list_for_each(tmp, &bus->children) {
105 n = pci_bus_max_busnr(pci_bus_b(tmp));
106 if(n > max)
107 max = n;
108 }
109 return max;
110}
111EXPORT_SYMBOL_GPL(pci_bus_max_busnr);
112
113#ifdef CONFIG_HAS_IOMEM
114void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar)
115{
116 /*
117 * Make sure the BAR is actually a memory resource, not an IO resource
118 */
119 if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM)) {
120 WARN_ON(1);
121 return NULL;
122 }
123 return ioremap_nocache(pci_resource_start(pdev, bar),
124 pci_resource_len(pdev, bar));
125}
126EXPORT_SYMBOL_GPL(pci_ioremap_bar);
127#endif
128
129#if 0
130/**
131 * pci_max_busnr - returns maximum PCI bus number
132 *
133 * Returns the highest PCI bus number present in the system global list of
134 * PCI buses.
135 */
136unsigned char __devinit
137pci_max_busnr(void)
138{
139 struct pci_bus *bus = NULL;
140 unsigned char max, n;
141
142 max = 0;
143 while ((bus = pci_find_next_bus(bus)) != NULL) {
144 n = pci_bus_max_busnr(bus);
145 if(n > max)
146 max = n;
147 }
148 return max;
149}
150
151#endif /* 0 */
152
153#define PCI_FIND_CAP_TTL 48
154
155static int __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn,
156 u8 pos, int cap, int *ttl)
157{
158 u8 id;
159
160 while ((*ttl)--) {
161 pci_bus_read_config_byte(bus, devfn, pos, &pos);
162 if (pos < 0x40)
163 break;
164 pos &= ~3;
165 pci_bus_read_config_byte(bus, devfn, pos + PCI_CAP_LIST_ID,
166 &id);
167 if (id == 0xff)
168 break;
169 if (id == cap)
170 return pos;
171 pos += PCI_CAP_LIST_NEXT;
172 }
173 return 0;
174}
175
176static int __pci_find_next_cap(struct pci_bus *bus, unsigned int devfn,
177 u8 pos, int cap)
178{
179 int ttl = PCI_FIND_CAP_TTL;
180
181 return __pci_find_next_cap_ttl(bus, devfn, pos, cap, &ttl);
182}
183
184int pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap)
185{
186 return __pci_find_next_cap(dev->bus, dev->devfn,
187 pos + PCI_CAP_LIST_NEXT, cap);
188}
189EXPORT_SYMBOL_GPL(pci_find_next_capability);
190
191static int __pci_bus_find_cap_start(struct pci_bus *bus,
192 unsigned int devfn, u8 hdr_type)
193{
194 u16 status;
195
196 pci_bus_read_config_word(bus, devfn, PCI_STATUS, &status);
197 if (!(status & PCI_STATUS_CAP_LIST))
198 return 0;
199
200 switch (hdr_type) {
201 case PCI_HEADER_TYPE_NORMAL:
202 case PCI_HEADER_TYPE_BRIDGE:
203 return PCI_CAPABILITY_LIST;
204 case PCI_HEADER_TYPE_CARDBUS:
205 return PCI_CB_CAPABILITY_LIST;
206 default:
207 return 0;
208 }
209
210 return 0;
211}
212
213/**
214 * pci_find_capability - query for devices' capabilities
215 * @dev: PCI device to query
216 * @cap: capability code
217 *
218 * Tell if a device supports a given PCI capability.
219 * Returns the address of the requested capability structure within the
220 * device's PCI configuration space or 0 in case the device does not
221 * support it. Possible values for @cap:
222 *
223 * %PCI_CAP_ID_PM Power Management
224 * %PCI_CAP_ID_AGP Accelerated Graphics Port
225 * %PCI_CAP_ID_VPD Vital Product Data
226 * %PCI_CAP_ID_SLOTID Slot Identification
227 * %PCI_CAP_ID_MSI Message Signalled Interrupts
228 * %PCI_CAP_ID_CHSWP CompactPCI HotSwap
229 * %PCI_CAP_ID_PCIX PCI-X
230 * %PCI_CAP_ID_EXP PCI Express
231 */
232int pci_find_capability(struct pci_dev *dev, int cap)
233{
234 int pos;
235
236 pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);
237 if (pos)
238 pos = __pci_find_next_cap(dev->bus, dev->devfn, pos, cap);
239
240 return pos;
241}
242
243/**
244 * pci_bus_find_capability - query for devices' capabilities
245 * @bus: the PCI bus to query
246 * @devfn: PCI device to query
247 * @cap: capability code
248 *
249 * Like pci_find_capability() but works for pci devices that do not have a
250 * pci_dev structure set up yet.
251 *
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.
255 */
256int pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap)
257{
258 int pos;
259 u8 hdr_type;
260
261 pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &hdr_type);
262
263 pos = __pci_bus_find_cap_start(bus, devfn, hdr_type & 0x7f);
264 if (pos)
265 pos = __pci_find_next_cap(bus, devfn, pos, cap);
266
267 return pos;
268}
269
270/**
271 * pci_find_ext_capability - Find an extended capability
272 * @dev: PCI device to query
273 * @cap: capability code
274 *
275 * Returns the address of the requested extended capability structure
276 * within the device's PCI configuration space or 0 if the device does
277 * not support it. Possible values for @cap:
278 *
279 * %PCI_EXT_CAP_ID_ERR Advanced Error Reporting
280 * %PCI_EXT_CAP_ID_VC Virtual Channel
281 * %PCI_EXT_CAP_ID_DSN Device Serial Number
282 * %PCI_EXT_CAP_ID_PWR Power Budgeting
283 */
284int pci_find_ext_capability(struct pci_dev *dev, int cap)
285{
286 u32 header;
287 int ttl;
288 int pos = PCI_CFG_SPACE_SIZE;
289
290 /* minimum 8 bytes per capability */
291 ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8;
292
293 if (dev->cfg_size <= PCI_CFG_SPACE_SIZE)
294 return 0;
295
296 if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
297 return 0;
298
299 /*
300 * If we have no capabilities, this is indicated by cap ID,
301 * cap version and next pointer all being 0.
302 */
303 if (header == 0)
304 return 0;
305
306 while (ttl-- > 0) {
307 if (PCI_EXT_CAP_ID(header) == cap)
308 return pos;
309
310 pos = PCI_EXT_CAP_NEXT(header);
311 if (pos < PCI_CFG_SPACE_SIZE)
312 break;
313
314 if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
315 break;
316 }
317
318 return 0;
319}
320EXPORT_SYMBOL_GPL(pci_find_ext_capability);
321
322/**
323 * pci_bus_find_ext_capability - find an extended capability
324 * @bus: the PCI bus to query
325 * @devfn: PCI device to query
326 * @cap: capability code
327 *
328 * Like pci_find_ext_capability() but works for pci devices that do not have a
329 * pci_dev structure set up yet.
330 *
331 * Returns the address of the requested capability structure within the
332 * device's PCI configuration space or 0 in case the device does not
333 * support it.
334 */
335int pci_bus_find_ext_capability(struct pci_bus *bus, unsigned int devfn,
336 int cap)
337{
338 u32 header;
339 int ttl;
340 int pos = PCI_CFG_SPACE_SIZE;
341
342 /* minimum 8 bytes per capability */
343 ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8;
344
345 if (!pci_bus_read_config_dword(bus, devfn, pos, &header))
346 return 0;
347 if (header == 0xffffffff || header == 0)
348 return 0;
349
350 while (ttl-- > 0) {
351 if (PCI_EXT_CAP_ID(header) == cap)
352 return pos;
353
354 pos = PCI_EXT_CAP_NEXT(header);
355 if (pos < PCI_CFG_SPACE_SIZE)
356 break;
357
358 if (!pci_bus_read_config_dword(bus, devfn, pos, &header))
359 break;
360 }
361
362 return 0;
363}
364
365static int __pci_find_next_ht_cap(struct pci_dev *dev, int pos, int ht_cap)
366{
367 int rc, ttl = PCI_FIND_CAP_TTL;
368 u8 cap, mask;
369
370 if (ht_cap == HT_CAPTYPE_SLAVE || ht_cap == HT_CAPTYPE_HOST)
371 mask = HT_3BIT_CAP_MASK;
372 else
373 mask = HT_5BIT_CAP_MASK;
374
375 pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn, pos,
376 PCI_CAP_ID_HT, &ttl);
377 while (pos) {
378 rc = pci_read_config_byte(dev, pos + 3, &cap);
379 if (rc != PCIBIOS_SUCCESSFUL)
380 return 0;
381
382 if ((cap & mask) == ht_cap)
383 return pos;
384
385 pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn,
386 pos + PCI_CAP_LIST_NEXT,
387 PCI_CAP_ID_HT, &ttl);
388 }
389
390 return 0;
391}
392/**
393 * pci_find_next_ht_capability - query a device's Hypertransport capabilities
394 * @dev: PCI device to query
395 * @pos: Position from which to continue searching
396 * @ht_cap: Hypertransport capability code
397 *
398 * To be used in conjunction with pci_find_ht_capability() to search for
399 * all capabilities matching @ht_cap. @pos should always be a value returned
400 * from pci_find_ht_capability().
401 *
402 * NB. To be 100% safe against broken PCI devices, the caller should take
403 * steps to avoid an infinite loop.
404 */
405int pci_find_next_ht_capability(struct pci_dev *dev, int pos, int ht_cap)
406{
407 return __pci_find_next_ht_cap(dev, pos + PCI_CAP_LIST_NEXT, ht_cap);
408}
409EXPORT_SYMBOL_GPL(pci_find_next_ht_capability);
410
411/**
412 * pci_find_ht_capability - query a device's Hypertransport capabilities
413 * @dev: PCI device to query
414 * @ht_cap: Hypertransport capability code
415 *
416 * Tell if a device supports a given Hypertransport capability.
417 * Returns an address within the device's PCI configuration space
418 * or 0 in case the device does not support the request capability.
419 * The address points to the PCI capability, of type PCI_CAP_ID_HT,
420 * which has a Hypertransport capability matching @ht_cap.
421 */
422int pci_find_ht_capability(struct pci_dev *dev, int ht_cap)
423{
424 int pos;
425
426 pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);
427 if (pos)
428 pos = __pci_find_next_ht_cap(dev, pos, ht_cap);
429
430 return pos;
431}
432EXPORT_SYMBOL_GPL(pci_find_ht_capability);
433
434/**
435 * pci_find_parent_resource - return resource region of parent bus of given region
436 * @dev: PCI device structure contains resources to be searched
437 * @res: child resource record for which parent is sought
438 *
439 * For given resource region of given device, return the resource
440 * region of parent bus the given region is contained in or where
441 * it should be allocated from.
442 */
443struct resource *
444pci_find_parent_resource(const struct pci_dev *dev, struct resource *res)
445{
446 const struct pci_bus *bus = dev->bus;
447 int i;
448 struct resource *best = NULL, *r;
449
450 pci_bus_for_each_resource(bus, r, i) {
451 if (!r)
452 continue;
453 if (res->start && !(res->start >= r->start && res->end <= r->end))
454 continue; /* Not contained */
455 if ((res->flags ^ r->flags) & (IORESOURCE_IO | IORESOURCE_MEM))
456 continue; /* Wrong type */
457 if (!((res->flags ^ r->flags) & IORESOURCE_PREFETCH))
458 return r; /* Exact match */
459 /* We can't insert a non-prefetch resource inside a prefetchable parent .. */
460 if (r->flags & IORESOURCE_PREFETCH)
461 continue;
462 /* .. but we can put a prefetchable resource inside a non-prefetchable one */
463 if (!best)
464 best = r;
465 }
466 return best;
467}
468
469/**
470 * pci_restore_bars - restore a devices BAR values (e.g. after wake-up)
471 * @dev: PCI device to have its BARs restored
472 *
473 * Restore the BAR values for a given device, so as to make it
474 * accessible by its driver.
475 */
476static void
477pci_restore_bars(struct pci_dev *dev)
478{
479 int i;
480
481 for (i = 0; i < PCI_BRIDGE_RESOURCES; i++)
482 pci_update_resource(dev, i);
483}
484
485static struct pci_platform_pm_ops *pci_platform_pm;
486
487int pci_set_platform_pm(struct pci_platform_pm_ops *ops)
488{
489 if (!ops->is_manageable || !ops->set_state || !ops->choose_state
490 || !ops->sleep_wake || !ops->can_wakeup)
491 return -EINVAL;
492 pci_platform_pm = ops;
493 return 0;
494}
495
496static inline bool platform_pci_power_manageable(struct pci_dev *dev)
497{
498 return pci_platform_pm ? pci_platform_pm->is_manageable(dev) : false;
499}
500
501static inline int platform_pci_set_power_state(struct pci_dev *dev,
502 pci_power_t t)
503{
504 return pci_platform_pm ? pci_platform_pm->set_state(dev, t) : -ENOSYS;
505}
506
507static inline pci_power_t platform_pci_choose_state(struct pci_dev *dev)
508{
509 return pci_platform_pm ?
510 pci_platform_pm->choose_state(dev) : PCI_POWER_ERROR;
511}
512
513static inline bool platform_pci_can_wakeup(struct pci_dev *dev)
514{
515 return pci_platform_pm ? pci_platform_pm->can_wakeup(dev) : false;
516}
517
518static inline int platform_pci_sleep_wake(struct pci_dev *dev, bool enable)
519{
520 return pci_platform_pm ?
521 pci_platform_pm->sleep_wake(dev, enable) : -ENODEV;
522}
523
524static inline int platform_pci_run_wake(struct pci_dev *dev, bool enable)
525{
526 return pci_platform_pm ?
527 pci_platform_pm->run_wake(dev, enable) : -ENODEV;
528}
529
530/**
531 * pci_raw_set_power_state - Use PCI PM registers to set the power state of
532 * given PCI device
533 * @dev: PCI device to handle.
534 * @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
535 *
536 * RETURN VALUE:
537 * -EINVAL if the requested state is invalid.
538 * -EIO if device does not support PCI PM or its PM capabilities register has a
539 * wrong version, or device doesn't support the requested state.
540 * 0 if device already is in the requested state.
541 * 0 if device's power state has been successfully changed.
542 */
543static int pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
544{
545 u16 pmcsr;
546 bool need_restore = false;
547
548 /* Check if we're already there */
549 if (dev->current_state == state)
550 return 0;
551
552 if (!dev->pm_cap)
553 return -EIO;
554
555 if (state < PCI_D0 || state > PCI_D3hot)
556 return -EINVAL;
557
558 /* Validate current state:
559 * Can enter D0 from any state, but if we can only go deeper
560 * to sleep if we're already in a low power state
561 */
562 if (state != PCI_D0 && dev->current_state <= PCI_D3cold
563 && dev->current_state > state) {
564 dev_err(&dev->dev, "invalid power transition "
565 "(from state %d to %d)\n", dev->current_state, state);
566 return -EINVAL;
567 }
568
569 /* check if this device supports the desired state */
570 if ((state == PCI_D1 && !dev->d1_support)
571 || (state == PCI_D2 && !dev->d2_support))
572 return -EIO;
573
574 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
575
576 /* If we're (effectively) in D3, force entire word to 0.
577 * This doesn't affect PME_Status, disables PME_En, and
578 * sets PowerState to 0.
579 */
580 switch (dev->current_state) {
581 case PCI_D0:
582 case PCI_D1:
583 case PCI_D2:
584 pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
585 pmcsr |= state;
586 break;
587 case PCI_D3hot:
588 case PCI_D3cold:
589 case PCI_UNKNOWN: /* Boot-up */
590 if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot
591 && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))
592 need_restore = true;
593 /* Fall-through: force to D0 */
594 default:
595 pmcsr = 0;
596 break;
597 }
598
599 /* enter specified state */
600 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
601
602 /* Mandatory power management transition delays */
603 /* see PCI PM 1.1 5.6.1 table 18 */
604 if (state == PCI_D3hot || dev->current_state == PCI_D3hot)
605 pci_dev_d3_sleep(dev);
606 else if (state == PCI_D2 || dev->current_state == PCI_D2)
607 udelay(PCI_PM_D2_DELAY);
608
609 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
610 dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
611 if (dev->current_state != state && printk_ratelimit())
612 dev_info(&dev->dev, "Refused to change power state, "
613 "currently in D%d\n", dev->current_state);
614
615 /* According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT
616 * INTERFACE SPECIFICATION, REV. 1.2", a device transitioning
617 * from D3hot to D0 _may_ perform an internal reset, thereby
618 * going to "D0 Uninitialized" rather than "D0 Initialized".
619 * For example, at least some versions of the 3c905B and the
620 * 3c556B exhibit this behaviour.
621 *
622 * At least some laptop BIOSen (e.g. the Thinkpad T21) leave
623 * devices in a D3hot state at boot. Consequently, we need to
624 * restore at least the BARs so that the device will be
625 * accessible to its driver.
626 */
627 if (need_restore)
628 pci_restore_bars(dev);
629
630 if (dev->bus->self)
631 pcie_aspm_pm_state_change(dev->bus->self);
632
633 return 0;
634}
635
636/**
637 * pci_update_current_state - Read PCI power state of given device from its
638 * PCI PM registers and cache it
639 * @dev: PCI device to handle.
640 * @state: State to cache in case the device doesn't have the PM capability
641 */
642void pci_update_current_state(struct pci_dev *dev, pci_power_t state)
643{
644 if (dev->pm_cap) {
645 u16 pmcsr;
646
647 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
648 dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
649 } else {
650 dev->current_state = state;
651 }
652}
653
654/**
655 * pci_platform_power_transition - Use platform to change device power state
656 * @dev: PCI device to handle.
657 * @state: State to put the device into.
658 */
659static int pci_platform_power_transition(struct pci_dev *dev, pci_power_t state)
660{
661 int error;
662
663 if (platform_pci_power_manageable(dev)) {
664 error = platform_pci_set_power_state(dev, state);
665 if (!error)
666 pci_update_current_state(dev, state);
667 } else {
668 error = -ENODEV;
669 /* Fall back to PCI_D0 if native PM is not supported */
670 if (!dev->pm_cap)
671 dev->current_state = PCI_D0;
672 }
673
674 return error;
675}
676
677/**
678 * __pci_start_power_transition - Start power transition of a PCI device
679 * @dev: PCI device to handle.
680 * @state: State to put the device into.
681 */
682static void __pci_start_power_transition(struct pci_dev *dev, pci_power_t state)
683{
684 if (state == PCI_D0)
685 pci_platform_power_transition(dev, PCI_D0);
686}
687
688/**
689 * __pci_complete_power_transition - Complete power transition of a PCI device
690 * @dev: PCI device to handle.
691 * @state: State to put the device into.
692 *
693 * This function should not be called directly by device drivers.
694 */
695int __pci_complete_power_transition(struct pci_dev *dev, pci_power_t state)
696{
697 return state >= PCI_D0 ?
698 pci_platform_power_transition(dev, state) : -EINVAL;
699}
700EXPORT_SYMBOL_GPL(__pci_complete_power_transition);
701
702/**
703 * pci_set_power_state - Set the power state of a PCI device
704 * @dev: PCI device to handle.
705 * @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
706 *
707 * Transition a device to a new power state, using the platform firmware and/or
708 * the device's PCI PM registers.
709 *
710 * RETURN VALUE:
711 * -EINVAL if the requested state is invalid.
712 * -EIO if device does not support PCI PM or its PM capabilities register has a
713 * wrong version, or device doesn't support the requested state.
714 * 0 if device already is in the requested state.
715 * 0 if device's power state has been successfully changed.
716 */
717int pci_set_power_state(struct pci_dev *dev, pci_power_t state)
718{
719 int error;
720
721 /* bound the state we're entering */
722 if (state > PCI_D3hot)
723 state = PCI_D3hot;
724 else if (state < PCI_D0)
725 state = PCI_D0;
726 else if ((state == PCI_D1 || state == PCI_D2) && pci_no_d1d2(dev))
727 /*
728 * If the device or the parent bridge do not support PCI PM,
729 * ignore the request if we're doing anything other than putting
730 * it into D0 (which would only happen on boot).
731 */
732 return 0;
733
734 __pci_start_power_transition(dev, state);
735
736 /* This device is quirked not to be put into D3, so
737 don't put it in D3 */
738 if (state == PCI_D3hot && (dev->dev_flags & PCI_DEV_FLAGS_NO_D3))
739 return 0;
740
741 error = pci_raw_set_power_state(dev, state);
742
743 if (!__pci_complete_power_transition(dev, state))
744 error = 0;
745 /*
746 * When aspm_policy is "powersave" this call ensures
747 * that ASPM is configured.
748 */
749 if (!error && dev->bus->self)
750 pcie_aspm_powersave_config_link(dev->bus->self);
751
752 return error;
753}
754
755/**
756 * pci_choose_state - Choose the power state of a PCI device
757 * @dev: PCI device to be suspended
758 * @state: target sleep state for the whole system. This is the value
759 * that is passed to suspend() function.
760 *
761 * Returns PCI power state suitable for given device and given system
762 * message.
763 */
764
765pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state)
766{
767 pci_power_t ret;
768
769 if (!pci_find_capability(dev, PCI_CAP_ID_PM))
770 return PCI_D0;
771
772 ret = platform_pci_choose_state(dev);
773 if (ret != PCI_POWER_ERROR)
774 return ret;
775
776 switch (state.event) {
777 case PM_EVENT_ON:
778 return PCI_D0;
779 case PM_EVENT_FREEZE:
780 case PM_EVENT_PRETHAW:
781 /* REVISIT both freeze and pre-thaw "should" use D0 */
782 case PM_EVENT_SUSPEND:
783 case PM_EVENT_HIBERNATE:
784 return PCI_D3hot;
785 default:
786 dev_info(&dev->dev, "unrecognized suspend event %d\n",
787 state.event);
788 BUG();
789 }
790 return PCI_D0;
791}
792
793EXPORT_SYMBOL(pci_choose_state);
794
795#define PCI_EXP_SAVE_REGS 7
796
797#define pcie_cap_has_devctl(type, flags) 1
798#define pcie_cap_has_lnkctl(type, flags) \
799 ((flags & PCI_EXP_FLAGS_VERS) > 1 || \
800 (type == PCI_EXP_TYPE_ROOT_PORT || \
801 type == PCI_EXP_TYPE_ENDPOINT || \
802 type == PCI_EXP_TYPE_LEG_END))
803#define pcie_cap_has_sltctl(type, flags) \
804 ((flags & PCI_EXP_FLAGS_VERS) > 1 || \
805 ((type == PCI_EXP_TYPE_ROOT_PORT) || \
806 (type == PCI_EXP_TYPE_DOWNSTREAM && \
807 (flags & PCI_EXP_FLAGS_SLOT))))
808#define pcie_cap_has_rtctl(type, flags) \
809 ((flags & PCI_EXP_FLAGS_VERS) > 1 || \
810 (type == PCI_EXP_TYPE_ROOT_PORT || \
811 type == PCI_EXP_TYPE_RC_EC))
812#define pcie_cap_has_devctl2(type, flags) \
813 ((flags & PCI_EXP_FLAGS_VERS) > 1)
814#define pcie_cap_has_lnkctl2(type, flags) \
815 ((flags & PCI_EXP_FLAGS_VERS) > 1)
816#define pcie_cap_has_sltctl2(type, flags) \
817 ((flags & PCI_EXP_FLAGS_VERS) > 1)
818
819static int pci_save_pcie_state(struct pci_dev *dev)
820{
821 int pos, i = 0;
822 struct pci_cap_saved_state *save_state;
823 u16 *cap;
824 u16 flags;
825
826 pos = pci_pcie_cap(dev);
827 if (!pos)
828 return 0;
829
830 save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
831 if (!save_state) {
832 dev_err(&dev->dev, "buffer not found in %s\n", __func__);
833 return -ENOMEM;
834 }
835 cap = (u16 *)&save_state->cap.data[0];
836
837 pci_read_config_word(dev, pos + PCI_EXP_FLAGS, &flags);
838
839 if (pcie_cap_has_devctl(dev->pcie_type, flags))
840 pci_read_config_word(dev, pos + PCI_EXP_DEVCTL, &cap[i++]);
841 if (pcie_cap_has_lnkctl(dev->pcie_type, flags))
842 pci_read_config_word(dev, pos + PCI_EXP_LNKCTL, &cap[i++]);
843 if (pcie_cap_has_sltctl(dev->pcie_type, flags))
844 pci_read_config_word(dev, pos + PCI_EXP_SLTCTL, &cap[i++]);
845 if (pcie_cap_has_rtctl(dev->pcie_type, flags))
846 pci_read_config_word(dev, pos + PCI_EXP_RTCTL, &cap[i++]);
847 if (pcie_cap_has_devctl2(dev->pcie_type, flags))
848 pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &cap[i++]);
849 if (pcie_cap_has_lnkctl2(dev->pcie_type, flags))
850 pci_read_config_word(dev, pos + PCI_EXP_LNKCTL2, &cap[i++]);
851 if (pcie_cap_has_sltctl2(dev->pcie_type, flags))
852 pci_read_config_word(dev, pos + PCI_EXP_SLTCTL2, &cap[i++]);
853
854 return 0;
855}
856
857static void pci_restore_pcie_state(struct pci_dev *dev)
858{
859 int i = 0, pos;
860 struct pci_cap_saved_state *save_state;
861 u16 *cap;
862 u16 flags;
863
864 save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
865 pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
866 if (!save_state || pos <= 0)
867 return;
868 cap = (u16 *)&save_state->cap.data[0];
869
870 pci_read_config_word(dev, pos + PCI_EXP_FLAGS, &flags);
871
872 if (pcie_cap_has_devctl(dev->pcie_type, flags))
873 pci_write_config_word(dev, pos + PCI_EXP_DEVCTL, cap[i++]);
874 if (pcie_cap_has_lnkctl(dev->pcie_type, flags))
875 pci_write_config_word(dev, pos + PCI_EXP_LNKCTL, cap[i++]);
876 if (pcie_cap_has_sltctl(dev->pcie_type, flags))
877 pci_write_config_word(dev, pos + PCI_EXP_SLTCTL, cap[i++]);
878 if (pcie_cap_has_rtctl(dev->pcie_type, flags))
879 pci_write_config_word(dev, pos + PCI_EXP_RTCTL, cap[i++]);
880 if (pcie_cap_has_devctl2(dev->pcie_type, flags))
881 pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, cap[i++]);
882 if (pcie_cap_has_lnkctl2(dev->pcie_type, flags))
883 pci_write_config_word(dev, pos + PCI_EXP_LNKCTL2, cap[i++]);
884 if (pcie_cap_has_sltctl2(dev->pcie_type, flags))
885 pci_write_config_word(dev, pos + PCI_EXP_SLTCTL2, cap[i++]);
886}
887
888
889static int pci_save_pcix_state(struct pci_dev *dev)
890{
891 int pos;
892 struct pci_cap_saved_state *save_state;
893
894 pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
895 if (pos <= 0)
896 return 0;
897
898 save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX);
899 if (!save_state) {
900 dev_err(&dev->dev, "buffer not found in %s\n", __func__);
901 return -ENOMEM;
902 }
903
904 pci_read_config_word(dev, pos + PCI_X_CMD,
905 (u16 *)save_state->cap.data);
906
907 return 0;
908}
909
910static void pci_restore_pcix_state(struct pci_dev *dev)
911{
912 int i = 0, pos;
913 struct pci_cap_saved_state *save_state;
914 u16 *cap;
915
916 save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX);
917 pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
918 if (!save_state || pos <= 0)
919 return;
920 cap = (u16 *)&save_state->cap.data[0];
921
922 pci_write_config_word(dev, pos + PCI_X_CMD, cap[i++]);
923}
924
925
926/**
927 * pci_save_state - save the PCI configuration space of a device before suspending
928 * @dev: - PCI device that we're dealing with
929 */
930int
931pci_save_state(struct pci_dev *dev)
932{
933 int i;
934 /* XXX: 100% dword access ok here? */
935 for (i = 0; i < 16; i++)
936 pci_read_config_dword(dev, i * 4, &dev->saved_config_space[i]);
937 dev->state_saved = true;
938 if ((i = pci_save_pcie_state(dev)) != 0)
939 return i;
940 if ((i = pci_save_pcix_state(dev)) != 0)
941 return i;
942 return 0;
943}
944
945/**
946 * pci_restore_state - Restore the saved state of a PCI device
947 * @dev: - PCI device that we're dealing with
948 */
949void pci_restore_state(struct pci_dev *dev)
950{
951 int i;
952 u32 val;
953
954 if (!dev->state_saved)
955 return;
956
957 /* PCI Express register must be restored first */
958 pci_restore_pcie_state(dev);
959
960 /*
961 * The Base Address register should be programmed before the command
962 * register(s)
963 */
964 for (i = 15; i >= 0; i--) {
965 pci_read_config_dword(dev, i * 4, &val);
966 if (val != dev->saved_config_space[i]) {
967 dev_printk(KERN_DEBUG, &dev->dev, "restoring config "
968 "space at offset %#x (was %#x, writing %#x)\n",
969 i, val, (int)dev->saved_config_space[i]);
970 pci_write_config_dword(dev,i * 4,
971 dev->saved_config_space[i]);
972 }
973 }
974 pci_restore_pcix_state(dev);
975 pci_restore_msi_state(dev);
976 pci_restore_iov_state(dev);
977
978 dev->state_saved = false;
979}
980
981struct pci_saved_state {
982 u32 config_space[16];
983 struct pci_cap_saved_data cap[0];
984};
985
986/**
987 * pci_store_saved_state - Allocate and return an opaque struct containing
988 * the device saved state.
989 * @dev: PCI device that we're dealing with
990 *
991 * Rerturn NULL if no state or error.
992 */
993struct pci_saved_state *pci_store_saved_state(struct pci_dev *dev)
994{
995 struct pci_saved_state *state;
996 struct pci_cap_saved_state *tmp;
997 struct pci_cap_saved_data *cap;
998 struct hlist_node *pos;
999 size_t size;
1000
1001 if (!dev->state_saved)
1002 return NULL;
1003
1004 size = sizeof(*state) + sizeof(struct pci_cap_saved_data);
1005
1006 hlist_for_each_entry(tmp, pos, &dev->saved_cap_space, next)
1007 size += sizeof(struct pci_cap_saved_data) + tmp->cap.size;
1008
1009 state = kzalloc(size, GFP_KERNEL);
1010 if (!state)
1011 return NULL;
1012
1013 memcpy(state->config_space, dev->saved_config_space,
1014 sizeof(state->config_space));
1015
1016 cap = state->cap;
1017 hlist_for_each_entry(tmp, pos, &dev->saved_cap_space, next) {
1018 size_t len = sizeof(struct pci_cap_saved_data) + tmp->cap.size;
1019 memcpy(cap, &tmp->cap, len);
1020 cap = (struct pci_cap_saved_data *)((u8 *)cap + len);
1021 }
1022 /* Empty cap_save terminates list */
1023
1024 return state;
1025}
1026EXPORT_SYMBOL_GPL(pci_store_saved_state);
1027
1028/**
1029 * pci_load_saved_state - Reload the provided save state into struct pci_dev.
1030 * @dev: PCI device that we're dealing with
1031 * @state: Saved state returned from pci_store_saved_state()
1032 */
1033int pci_load_saved_state(struct pci_dev *dev, struct pci_saved_state *state)
1034{
1035 struct pci_cap_saved_data *cap;
1036
1037 dev->state_saved = false;
1038
1039 if (!state)
1040 return 0;
1041
1042 memcpy(dev->saved_config_space, state->config_space,
1043 sizeof(state->config_space));
1044
1045 cap = state->cap;
1046 while (cap->size) {
1047 struct pci_cap_saved_state *tmp;
1048
1049 tmp = pci_find_saved_cap(dev, cap->cap_nr);
1050 if (!tmp || tmp->cap.size != cap->size)
1051 return -EINVAL;
1052
1053 memcpy(tmp->cap.data, cap->data, tmp->cap.size);
1054 cap = (struct pci_cap_saved_data *)((u8 *)cap +
1055 sizeof(struct pci_cap_saved_data) + cap->size);
1056 }
1057
1058 dev->state_saved = true;
1059 return 0;
1060}
1061EXPORT_SYMBOL_GPL(pci_load_saved_state);
1062
1063/**
1064 * pci_load_and_free_saved_state - Reload the save state pointed to by state,
1065 * and free the memory allocated for it.
1066 * @dev: PCI device that we're dealing with
1067 * @state: Pointer to saved state returned from pci_store_saved_state()
1068 */
1069int pci_load_and_free_saved_state(struct pci_dev *dev,
1070 struct pci_saved_state **state)
1071{
1072 int ret = pci_load_saved_state(dev, *state);
1073 kfree(*state);
1074 *state = NULL;
1075 return ret;
1076}
1077EXPORT_SYMBOL_GPL(pci_load_and_free_saved_state);
1078
1079static int do_pci_enable_device(struct pci_dev *dev, int bars)
1080{
1081 int err;
1082
1083 err = pci_set_power_state(dev, PCI_D0);
1084 if (err < 0 && err != -EIO)
1085 return err;
1086 err = pcibios_enable_device(dev, bars);
1087 if (err < 0)
1088 return err;
1089 pci_fixup_device(pci_fixup_enable, dev);
1090
1091 return 0;
1092}
1093
1094/**
1095 * pci_reenable_device - Resume abandoned device
1096 * @dev: PCI device to be resumed
1097 *
1098 * Note this function is a backend of pci_default_resume and is not supposed
1099 * to be called by normal code, write proper resume handler and use it instead.
1100 */
1101int pci_reenable_device(struct pci_dev *dev)
1102{
1103 if (pci_is_enabled(dev))
1104 return do_pci_enable_device(dev, (1 << PCI_NUM_RESOURCES) - 1);
1105 return 0;
1106}
1107
1108static int __pci_enable_device_flags(struct pci_dev *dev,
1109 resource_size_t flags)
1110{
1111 int err;
1112 int i, bars = 0;
1113
1114 /*
1115 * Power state could be unknown at this point, either due to a fresh
1116 * boot or a device removal call. So get the current power state
1117 * so that things like MSI message writing will behave as expected
1118 * (e.g. if the device really is in D0 at enable time).
1119 */
1120 if (dev->pm_cap) {
1121 u16 pmcsr;
1122 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
1123 dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
1124 }
1125
1126 if (atomic_add_return(1, &dev->enable_cnt) > 1)
1127 return 0; /* already enabled */
1128
1129 for (i = 0; i < DEVICE_COUNT_RESOURCE; i++)
1130 if (dev->resource[i].flags & flags)
1131 bars |= (1 << i);
1132
1133 err = do_pci_enable_device(dev, bars);
1134 if (err < 0)
1135 atomic_dec(&dev->enable_cnt);
1136 return err;
1137}
1138
1139/**
1140 * pci_enable_device_io - Initialize a device for use with IO space
1141 * @dev: PCI device to be initialized
1142 *
1143 * Initialize device before it's used by a driver. Ask low-level code
1144 * to enable I/O resources. Wake up the device if it was suspended.
1145 * Beware, this function can fail.
1146 */
1147int pci_enable_device_io(struct pci_dev *dev)
1148{
1149 return __pci_enable_device_flags(dev, IORESOURCE_IO);
1150}
1151
1152/**
1153 * pci_enable_device_mem - Initialize a device for use with Memory space
1154 * @dev: PCI device to be initialized
1155 *
1156 * Initialize device before it's used by a driver. Ask low-level code
1157 * to enable Memory resources. Wake up the device if it was suspended.
1158 * Beware, this function can fail.
1159 */
1160int pci_enable_device_mem(struct pci_dev *dev)
1161{
1162 return __pci_enable_device_flags(dev, IORESOURCE_MEM);
1163}
1164
1165/**
1166 * pci_enable_device - Initialize device before it's used by a driver.
1167 * @dev: PCI device to be initialized
1168 *
1169 * Initialize device before it's used by a driver. Ask low-level code
1170 * to enable I/O and memory. Wake up the device if it was suspended.
1171 * Beware, this function can fail.
1172 *
1173 * Note we don't actually enable the device many times if we call
1174 * this function repeatedly (we just increment the count).
1175 */
1176int pci_enable_device(struct pci_dev *dev)
1177{
1178 return __pci_enable_device_flags(dev, IORESOURCE_MEM | IORESOURCE_IO);
1179}
1180
1181/*
1182 * Managed PCI resources. This manages device on/off, intx/msi/msix
1183 * on/off and BAR regions. pci_dev itself records msi/msix status, so
1184 * there's no need to track it separately. pci_devres is initialized
1185 * when a device is enabled using managed PCI device enable interface.
1186 */
1187struct pci_devres {
1188 unsigned int enabled:1;
1189 unsigned int pinned:1;
1190 unsigned int orig_intx:1;
1191 unsigned int restore_intx:1;
1192 u32 region_mask;
1193};
1194
1195static void pcim_release(struct device *gendev, void *res)
1196{
1197 struct pci_dev *dev = container_of(gendev, struct pci_dev, dev);
1198 struct pci_devres *this = res;
1199 int i;
1200
1201 if (dev->msi_enabled)
1202 pci_disable_msi(dev);
1203 if (dev->msix_enabled)
1204 pci_disable_msix(dev);
1205
1206 for (i = 0; i < DEVICE_COUNT_RESOURCE; i++)
1207 if (this->region_mask & (1 << i))
1208 pci_release_region(dev, i);
1209
1210 if (this->restore_intx)
1211 pci_intx(dev, this->orig_intx);
1212
1213 if (this->enabled && !this->pinned)
1214 pci_disable_device(dev);
1215}
1216
1217static struct pci_devres * get_pci_dr(struct pci_dev *pdev)
1218{
1219 struct pci_devres *dr, *new_dr;
1220
1221 dr = devres_find(&pdev->dev, pcim_release, NULL, NULL);
1222 if (dr)
1223 return dr;
1224
1225 new_dr = devres_alloc(pcim_release, sizeof(*new_dr), GFP_KERNEL);
1226 if (!new_dr)
1227 return NULL;
1228 return devres_get(&pdev->dev, new_dr, NULL, NULL);
1229}
1230
1231static struct pci_devres * find_pci_dr(struct pci_dev *pdev)
1232{
1233 if (pci_is_managed(pdev))
1234 return devres_find(&pdev->dev, pcim_release, NULL, NULL);
1235 return NULL;
1236}
1237
1238/**
1239 * pcim_enable_device - Managed pci_enable_device()
1240 * @pdev: PCI device to be initialized
1241 *
1242 * Managed pci_enable_device().
1243 */
1244int pcim_enable_device(struct pci_dev *pdev)
1245{
1246 struct pci_devres *dr;
1247 int rc;
1248
1249 dr = get_pci_dr(pdev);
1250 if (unlikely(!dr))
1251 return -ENOMEM;
1252 if (dr->enabled)
1253 return 0;
1254
1255 rc = pci_enable_device(pdev);
1256 if (!rc) {
1257 pdev->is_managed = 1;
1258 dr->enabled = 1;
1259 }
1260 return rc;
1261}
1262
1263/**
1264 * pcim_pin_device - Pin managed PCI device
1265 * @pdev: PCI device to pin
1266 *
1267 * Pin managed PCI device @pdev. Pinned device won't be disabled on
1268 * driver detach. @pdev must have been enabled with
1269 * pcim_enable_device().
1270 */
1271void pcim_pin_device(struct pci_dev *pdev)
1272{
1273 struct pci_devres *dr;
1274
1275 dr = find_pci_dr(pdev);
1276 WARN_ON(!dr || !dr->enabled);
1277 if (dr)
1278 dr->pinned = 1;
1279}
1280
1281/**
1282 * pcibios_disable_device - disable arch specific PCI resources for device dev
1283 * @dev: the PCI device to disable
1284 *
1285 * Disables architecture specific PCI resources for the device. This
1286 * is the default implementation. Architecture implementations can
1287 * override this.
1288 */
1289void __attribute__ ((weak)) pcibios_disable_device (struct pci_dev *dev) {}
1290
1291static void do_pci_disable_device(struct pci_dev *dev)
1292{
1293 u16 pci_command;
1294
1295 pci_read_config_word(dev, PCI_COMMAND, &pci_command);
1296 if (pci_command & PCI_COMMAND_MASTER) {
1297 pci_command &= ~PCI_COMMAND_MASTER;
1298 pci_write_config_word(dev, PCI_COMMAND, pci_command);
1299 }
1300
1301 pcibios_disable_device(dev);
1302}
1303
1304/**
1305 * pci_disable_enabled_device - Disable device without updating enable_cnt
1306 * @dev: PCI device to disable
1307 *
1308 * NOTE: This function is a backend of PCI power management routines and is
1309 * not supposed to be called drivers.
1310 */
1311void pci_disable_enabled_device(struct pci_dev *dev)
1312{
1313 if (pci_is_enabled(dev))
1314 do_pci_disable_device(dev);
1315}
1316
1317/**
1318 * pci_disable_device - Disable PCI device after use
1319 * @dev: PCI device to be disabled
1320 *
1321 * Signal to the system that the PCI device is not in use by the system
1322 * anymore. This only involves disabling PCI bus-mastering, if active.
1323 *
1324 * Note we don't actually disable the device until all callers of
1325 * pci_enable_device() have called pci_disable_device().
1326 */
1327void
1328pci_disable_device(struct pci_dev *dev)
1329{
1330 struct pci_devres *dr;
1331
1332 dr = find_pci_dr(dev);
1333 if (dr)
1334 dr->enabled = 0;
1335
1336 if (atomic_sub_return(1, &dev->enable_cnt) != 0)
1337 return;
1338
1339 do_pci_disable_device(dev);
1340
1341 dev->is_busmaster = 0;
1342}
1343
1344/**
1345 * pcibios_set_pcie_reset_state - set reset state for device dev
1346 * @dev: the PCIe device reset
1347 * @state: Reset state to enter into
1348 *
1349 *
1350 * Sets the PCIe reset state for the device. This is the default
1351 * implementation. Architecture implementations can override this.
1352 */
1353int __attribute__ ((weak)) pcibios_set_pcie_reset_state(struct pci_dev *dev,
1354 enum pcie_reset_state state)
1355{
1356 return -EINVAL;
1357}
1358
1359/**
1360 * pci_set_pcie_reset_state - set reset state for device dev
1361 * @dev: the PCIe device reset
1362 * @state: Reset state to enter into
1363 *
1364 *
1365 * Sets the PCI reset state for the device.
1366 */
1367int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state)
1368{
1369 return pcibios_set_pcie_reset_state(dev, state);
1370}
1371
1372/**
1373 * pci_check_pme_status - Check if given device has generated PME.
1374 * @dev: Device to check.
1375 *
1376 * Check the PME status of the device and if set, clear it and clear PME enable
1377 * (if set). Return 'true' if PME status and PME enable were both set or
1378 * 'false' otherwise.
1379 */
1380bool pci_check_pme_status(struct pci_dev *dev)
1381{
1382 int pmcsr_pos;
1383 u16 pmcsr;
1384 bool ret = false;
1385
1386 if (!dev->pm_cap)
1387 return false;
1388
1389 pmcsr_pos = dev->pm_cap + PCI_PM_CTRL;
1390 pci_read_config_word(dev, pmcsr_pos, &pmcsr);
1391 if (!(pmcsr & PCI_PM_CTRL_PME_STATUS))
1392 return false;
1393
1394 /* Clear PME status. */
1395 pmcsr |= PCI_PM_CTRL_PME_STATUS;
1396 if (pmcsr & PCI_PM_CTRL_PME_ENABLE) {
1397 /* Disable PME to avoid interrupt flood. */
1398 pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
1399 ret = true;
1400 }
1401
1402 pci_write_config_word(dev, pmcsr_pos, pmcsr);
1403
1404 return ret;
1405}
1406
1407/**
1408 * pci_pme_wakeup - Wake up a PCI device if its PME Status bit is set.
1409 * @dev: Device to handle.
1410 * @ign: Ignored.
1411 *
1412 * Check if @dev has generated PME and queue a resume request for it in that
1413 * case.
1414 */
1415static int pci_pme_wakeup(struct pci_dev *dev, void *ign)
1416{
1417 if (pci_check_pme_status(dev)) {
1418 pci_wakeup_event(dev);
1419 pm_request_resume(&dev->dev);
1420 }
1421 return 0;
1422}
1423
1424/**
1425 * pci_pme_wakeup_bus - Walk given bus and wake up devices on it, if necessary.
1426 * @bus: Top bus of the subtree to walk.
1427 */
1428void pci_pme_wakeup_bus(struct pci_bus *bus)
1429{
1430 if (bus)
1431 pci_walk_bus(bus, pci_pme_wakeup, NULL);
1432}
1433
1434/**
1435 * pci_pme_capable - check the capability of PCI device to generate PME#
1436 * @dev: PCI device to handle.
1437 * @state: PCI state from which device will issue PME#.
1438 */
1439bool pci_pme_capable(struct pci_dev *dev, pci_power_t state)
1440{
1441 if (!dev->pm_cap)
1442 return false;
1443
1444 return !!(dev->pme_support & (1 << state));
1445}
1446
1447static void pci_pme_list_scan(struct work_struct *work)
1448{
1449 struct pci_pme_device *pme_dev;
1450
1451 mutex_lock(&pci_pme_list_mutex);
1452 if (!list_empty(&pci_pme_list)) {
1453 list_for_each_entry(pme_dev, &pci_pme_list, list)
1454 pci_pme_wakeup(pme_dev->dev, NULL);
1455 schedule_delayed_work(&pci_pme_work, msecs_to_jiffies(PME_TIMEOUT));
1456 }
1457 mutex_unlock(&pci_pme_list_mutex);
1458}
1459
1460/**
1461 * pci_external_pme - is a device an external PCI PME source?
1462 * @dev: PCI device to check
1463 *
1464 */
1465
1466static bool pci_external_pme(struct pci_dev *dev)
1467{
1468 if (pci_is_pcie(dev) || dev->bus->number == 0)
1469 return false;
1470 return true;
1471}
1472
1473/**
1474 * pci_pme_active - enable or disable PCI device's PME# function
1475 * @dev: PCI device to handle.
1476 * @enable: 'true' to enable PME# generation; 'false' to disable it.
1477 *
1478 * The caller must verify that the device is capable of generating PME# before
1479 * calling this function with @enable equal to 'true'.
1480 */
1481void pci_pme_active(struct pci_dev *dev, bool enable)
1482{
1483 u16 pmcsr;
1484
1485 if (!dev->pm_cap)
1486 return;
1487
1488 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
1489 /* Clear PME_Status by writing 1 to it and enable PME# */
1490 pmcsr |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE;
1491 if (!enable)
1492 pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
1493
1494 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
1495
1496 /* PCI (as opposed to PCIe) PME requires that the device have
1497 its PME# line hooked up correctly. Not all hardware vendors
1498 do this, so the PME never gets delivered and the device
1499 remains asleep. The easiest way around this is to
1500 periodically walk the list of suspended devices and check
1501 whether any have their PME flag set. The assumption is that
1502 we'll wake up often enough anyway that this won't be a huge
1503 hit, and the power savings from the devices will still be a
1504 win. */
1505
1506 if (pci_external_pme(dev)) {
1507 struct pci_pme_device *pme_dev;
1508 if (enable) {
1509 pme_dev = kmalloc(sizeof(struct pci_pme_device),
1510 GFP_KERNEL);
1511 if (!pme_dev)
1512 goto out;
1513 pme_dev->dev = dev;
1514 mutex_lock(&pci_pme_list_mutex);
1515 list_add(&pme_dev->list, &pci_pme_list);
1516 if (list_is_singular(&pci_pme_list))
1517 schedule_delayed_work(&pci_pme_work,
1518 msecs_to_jiffies(PME_TIMEOUT));
1519 mutex_unlock(&pci_pme_list_mutex);
1520 } else {
1521 mutex_lock(&pci_pme_list_mutex);
1522 list_for_each_entry(pme_dev, &pci_pme_list, list) {
1523 if (pme_dev->dev == dev) {
1524 list_del(&pme_dev->list);
1525 kfree(pme_dev);
1526 break;
1527 }
1528 }
1529 mutex_unlock(&pci_pme_list_mutex);
1530 }
1531 }
1532
1533out:
1534 dev_printk(KERN_DEBUG, &dev->dev, "PME# %s\n",
1535 enable ? "enabled" : "disabled");
1536}
1537
1538/**
1539 * __pci_enable_wake - enable PCI device as wakeup event source
1540 * @dev: PCI device affected
1541 * @state: PCI state from which device will issue wakeup events
1542 * @runtime: True if the events are to be generated at run time
1543 * @enable: True to enable event generation; false to disable
1544 *
1545 * This enables the device as a wakeup event source, or disables it.
1546 * When such events involves platform-specific hooks, those hooks are
1547 * called automatically by this routine.
1548 *
1549 * Devices with legacy power management (no standard PCI PM capabilities)
1550 * always require such platform hooks.
1551 *
1552 * RETURN VALUE:
1553 * 0 is returned on success
1554 * -EINVAL is returned if device is not supposed to wake up the system
1555 * Error code depending on the platform is returned if both the platform and
1556 * the native mechanism fail to enable the generation of wake-up events
1557 */
1558int __pci_enable_wake(struct pci_dev *dev, pci_power_t state,
1559 bool runtime, bool enable)
1560{
1561 int ret = 0;
1562
1563 if (enable && !runtime && !device_may_wakeup(&dev->dev))
1564 return -EINVAL;
1565
1566 /* Don't do the same thing twice in a row for one device. */
1567 if (!!enable == !!dev->wakeup_prepared)
1568 return 0;
1569
1570 /*
1571 * According to "PCI System Architecture" 4th ed. by Tom Shanley & Don
1572 * Anderson we should be doing PME# wake enable followed by ACPI wake
1573 * enable. To disable wake-up we call the platform first, for symmetry.
1574 */
1575
1576 if (enable) {
1577 int error;
1578
1579 if (pci_pme_capable(dev, state))
1580 pci_pme_active(dev, true);
1581 else
1582 ret = 1;
1583 error = runtime ? platform_pci_run_wake(dev, true) :
1584 platform_pci_sleep_wake(dev, true);
1585 if (ret)
1586 ret = error;
1587 if (!ret)
1588 dev->wakeup_prepared = true;
1589 } else {
1590 if (runtime)
1591 platform_pci_run_wake(dev, false);
1592 else
1593 platform_pci_sleep_wake(dev, false);
1594 pci_pme_active(dev, false);
1595 dev->wakeup_prepared = false;
1596 }
1597
1598 return ret;
1599}
1600EXPORT_SYMBOL(__pci_enable_wake);
1601
1602/**
1603 * pci_wake_from_d3 - enable/disable device to wake up from D3_hot or D3_cold
1604 * @dev: PCI device to prepare
1605 * @enable: True to enable wake-up event generation; false to disable
1606 *
1607 * Many drivers want the device to wake up the system from D3_hot or D3_cold
1608 * and this function allows them to set that up cleanly - pci_enable_wake()
1609 * should not be called twice in a row to enable wake-up due to PCI PM vs ACPI
1610 * ordering constraints.
1611 *
1612 * This function only returns error code if the device is not capable of
1613 * generating PME# from both D3_hot and D3_cold, and the platform is unable to
1614 * enable wake-up power for it.
1615 */
1616int pci_wake_from_d3(struct pci_dev *dev, bool enable)
1617{
1618 return pci_pme_capable(dev, PCI_D3cold) ?
1619 pci_enable_wake(dev, PCI_D3cold, enable) :
1620 pci_enable_wake(dev, PCI_D3hot, enable);
1621}
1622
1623/**
1624 * pci_target_state - find an appropriate low power state for a given PCI dev
1625 * @dev: PCI device
1626 *
1627 * Use underlying platform code to find a supported low power state for @dev.
1628 * If the platform can't manage @dev, return the deepest state from which it
1629 * can generate wake events, based on any available PME info.
1630 */
1631pci_power_t pci_target_state(struct pci_dev *dev)
1632{
1633 pci_power_t target_state = PCI_D3hot;
1634
1635 if (platform_pci_power_manageable(dev)) {
1636 /*
1637 * Call the platform to choose the target state of the device
1638 * and enable wake-up from this state if supported.
1639 */
1640 pci_power_t state = platform_pci_choose_state(dev);
1641
1642 switch (state) {
1643 case PCI_POWER_ERROR:
1644 case PCI_UNKNOWN:
1645 break;
1646 case PCI_D1:
1647 case PCI_D2:
1648 if (pci_no_d1d2(dev))
1649 break;
1650 default:
1651 target_state = state;
1652 }
1653 } else if (!dev->pm_cap) {
1654 target_state = PCI_D0;
1655 } else if (device_may_wakeup(&dev->dev)) {
1656 /*
1657 * Find the deepest state from which the device can generate
1658 * wake-up events, make it the target state and enable device
1659 * to generate PME#.
1660 */
1661 if (dev->pme_support) {
1662 while (target_state
1663 && !(dev->pme_support & (1 << target_state)))
1664 target_state--;
1665 }
1666 }
1667
1668 return target_state;
1669}
1670
1671/**
1672 * pci_prepare_to_sleep - prepare PCI device for system-wide transition into a sleep state
1673 * @dev: Device to handle.
1674 *
1675 * Choose the power state appropriate for the device depending on whether
1676 * it can wake up the system and/or is power manageable by the platform
1677 * (PCI_D3hot is the default) and put the device into that state.
1678 */
1679int pci_prepare_to_sleep(struct pci_dev *dev)
1680{
1681 pci_power_t target_state = pci_target_state(dev);
1682 int error;
1683
1684 if (target_state == PCI_POWER_ERROR)
1685 return -EIO;
1686
1687 pci_enable_wake(dev, target_state, device_may_wakeup(&dev->dev));
1688
1689 error = pci_set_power_state(dev, target_state);
1690
1691 if (error)
1692 pci_enable_wake(dev, target_state, false);
1693
1694 return error;
1695}
1696
1697/**
1698 * pci_back_from_sleep - turn PCI device on during system-wide transition into working state
1699 * @dev: Device to handle.
1700 *
1701 * Disable device's system wake-up capability and put it into D0.
1702 */
1703int pci_back_from_sleep(struct pci_dev *dev)
1704{
1705 pci_enable_wake(dev, PCI_D0, false);
1706 return pci_set_power_state(dev, PCI_D0);
1707}
1708
1709/**
1710 * pci_finish_runtime_suspend - Carry out PCI-specific part of runtime suspend.
1711 * @dev: PCI device being suspended.
1712 *
1713 * Prepare @dev to generate wake-up events at run time and put it into a low
1714 * power state.
1715 */
1716int pci_finish_runtime_suspend(struct pci_dev *dev)
1717{
1718 pci_power_t target_state = pci_target_state(dev);
1719 int error;
1720
1721 if (target_state == PCI_POWER_ERROR)
1722 return -EIO;
1723
1724 __pci_enable_wake(dev, target_state, true, pci_dev_run_wake(dev));
1725
1726 error = pci_set_power_state(dev, target_state);
1727
1728 if (error)
1729 __pci_enable_wake(dev, target_state, true, false);
1730
1731 return error;
1732}
1733
1734/**
1735 * pci_dev_run_wake - Check if device can generate run-time wake-up events.
1736 * @dev: Device to check.
1737 *
1738 * Return true if the device itself is cabable of generating wake-up events
1739 * (through the platform or using the native PCIe PME) or if the device supports
1740 * PME and one of its upstream bridges can generate wake-up events.
1741 */
1742bool pci_dev_run_wake(struct pci_dev *dev)
1743{
1744 struct pci_bus *bus = dev->bus;
1745
1746 if (device_run_wake(&dev->dev))
1747 return true;
1748
1749 if (!dev->pme_support)
1750 return false;
1751
1752 while (bus->parent) {
1753 struct pci_dev *bridge = bus->self;
1754
1755 if (device_run_wake(&bridge->dev))
1756 return true;
1757
1758 bus = bus->parent;
1759 }
1760
1761 /* We have reached the root bus. */
1762 if (bus->bridge)
1763 return device_run_wake(bus->bridge);
1764
1765 return false;
1766}
1767EXPORT_SYMBOL_GPL(pci_dev_run_wake);
1768
1769/**
1770 * pci_pm_init - Initialize PM functions of given PCI device
1771 * @dev: PCI device to handle.
1772 */
1773void pci_pm_init(struct pci_dev *dev)
1774{
1775 int pm;
1776 u16 pmc;
1777
1778 pm_runtime_forbid(&dev->dev);
1779 device_enable_async_suspend(&dev->dev);
1780 dev->wakeup_prepared = false;
1781
1782 dev->pm_cap = 0;
1783
1784 /* find PCI PM capability in list */
1785 pm = pci_find_capability(dev, PCI_CAP_ID_PM);
1786 if (!pm)
1787 return;
1788 /* Check device's ability to generate PME# */
1789 pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
1790
1791 if ((pmc & PCI_PM_CAP_VER_MASK) > 3) {
1792 dev_err(&dev->dev, "unsupported PM cap regs version (%u)\n",
1793 pmc & PCI_PM_CAP_VER_MASK);
1794 return;
1795 }
1796
1797 dev->pm_cap = pm;
1798 dev->d3_delay = PCI_PM_D3_WAIT;
1799
1800 dev->d1_support = false;
1801 dev->d2_support = false;
1802 if (!pci_no_d1d2(dev)) {
1803 if (pmc & PCI_PM_CAP_D1)
1804 dev->d1_support = true;
1805 if (pmc & PCI_PM_CAP_D2)
1806 dev->d2_support = true;
1807
1808 if (dev->d1_support || dev->d2_support)
1809 dev_printk(KERN_DEBUG, &dev->dev, "supports%s%s\n",
1810 dev->d1_support ? " D1" : "",
1811 dev->d2_support ? " D2" : "");
1812 }
1813
1814 pmc &= PCI_PM_CAP_PME_MASK;
1815 if (pmc) {
1816 dev_printk(KERN_DEBUG, &dev->dev,
1817 "PME# supported from%s%s%s%s%s\n",
1818 (pmc & PCI_PM_CAP_PME_D0) ? " D0" : "",
1819 (pmc & PCI_PM_CAP_PME_D1) ? " D1" : "",
1820 (pmc & PCI_PM_CAP_PME_D2) ? " D2" : "",
1821 (pmc & PCI_PM_CAP_PME_D3) ? " D3hot" : "",
1822 (pmc & PCI_PM_CAP_PME_D3cold) ? " D3cold" : "");
1823 dev->pme_support = pmc >> PCI_PM_CAP_PME_SHIFT;
1824 /*
1825 * Make device's PM flags reflect the wake-up capability, but
1826 * let the user space enable it to wake up the system as needed.
1827 */
1828 device_set_wakeup_capable(&dev->dev, true);
1829 /* Disable the PME# generation functionality */
1830 pci_pme_active(dev, false);
1831 } else {
1832 dev->pme_support = 0;
1833 }
1834}
1835
1836/**
1837 * platform_pci_wakeup_init - init platform wakeup if present
1838 * @dev: PCI device
1839 *
1840 * Some devices don't have PCI PM caps but can still generate wakeup
1841 * events through platform methods (like ACPI events). If @dev supports
1842 * platform wakeup events, set the device flag to indicate as much. This
1843 * may be redundant if the device also supports PCI PM caps, but double
1844 * initialization should be safe in that case.
1845 */
1846void platform_pci_wakeup_init(struct pci_dev *dev)
1847{
1848 if (!platform_pci_can_wakeup(dev))
1849 return;
1850
1851 device_set_wakeup_capable(&dev->dev, true);
1852 platform_pci_sleep_wake(dev, false);
1853}
1854
1855/**
1856 * pci_add_save_buffer - allocate buffer for saving given capability registers
1857 * @dev: the PCI device
1858 * @cap: the capability to allocate the buffer for
1859 * @size: requested size of the buffer
1860 */
1861static int pci_add_cap_save_buffer(
1862 struct pci_dev *dev, char cap, unsigned int size)
1863{
1864 int pos;
1865 struct pci_cap_saved_state *save_state;
1866
1867 pos = pci_find_capability(dev, cap);
1868 if (pos <= 0)
1869 return 0;
1870
1871 save_state = kzalloc(sizeof(*save_state) + size, GFP_KERNEL);
1872 if (!save_state)
1873 return -ENOMEM;
1874
1875 save_state->cap.cap_nr = cap;
1876 save_state->cap.size = size;
1877 pci_add_saved_cap(dev, save_state);
1878
1879 return 0;
1880}
1881
1882/**
1883 * pci_allocate_cap_save_buffers - allocate buffers for saving capabilities
1884 * @dev: the PCI device
1885 */
1886void pci_allocate_cap_save_buffers(struct pci_dev *dev)
1887{
1888 int error;
1889
1890 error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_EXP,
1891 PCI_EXP_SAVE_REGS * sizeof(u16));
1892 if (error)
1893 dev_err(&dev->dev,
1894 "unable to preallocate PCI Express save buffer\n");
1895
1896 error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_PCIX, sizeof(u16));
1897 if (error)
1898 dev_err(&dev->dev,
1899 "unable to preallocate PCI-X save buffer\n");
1900}
1901
1902/**
1903 * pci_enable_ari - enable ARI forwarding if hardware support it
1904 * @dev: the PCI device
1905 */
1906void pci_enable_ari(struct pci_dev *dev)
1907{
1908 int pos;
1909 u32 cap;
1910 u16 flags, ctrl;
1911 struct pci_dev *bridge;
1912
1913 if (!pci_is_pcie(dev) || dev->devfn)
1914 return;
1915
1916 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI);
1917 if (!pos)
1918 return;
1919
1920 bridge = dev->bus->self;
1921 if (!bridge || !pci_is_pcie(bridge))
1922 return;
1923
1924 pos = pci_pcie_cap(bridge);
1925 if (!pos)
1926 return;
1927
1928 /* ARI is a PCIe v2 feature */
1929 pci_read_config_word(bridge, pos + PCI_EXP_FLAGS, &flags);
1930 if ((flags & PCI_EXP_FLAGS_VERS) < 2)
1931 return;
1932
1933 pci_read_config_dword(bridge, pos + PCI_EXP_DEVCAP2, &cap);
1934 if (!(cap & PCI_EXP_DEVCAP2_ARI))
1935 return;
1936
1937 pci_read_config_word(bridge, pos + PCI_EXP_DEVCTL2, &ctrl);
1938 ctrl |= PCI_EXP_DEVCTL2_ARI;
1939 pci_write_config_word(bridge, pos + PCI_EXP_DEVCTL2, ctrl);
1940
1941 bridge->ari_enabled = 1;
1942}
1943
1944/**
1945 * pci_enable_ido - enable ID-based ordering on a device
1946 * @dev: the PCI device
1947 * @type: which types of IDO to enable
1948 *
1949 * Enable ID-based ordering on @dev. @type can contain the bits
1950 * %PCI_EXP_IDO_REQUEST and/or %PCI_EXP_IDO_COMPLETION to indicate
1951 * which types of transactions are allowed to be re-ordered.
1952 */
1953void pci_enable_ido(struct pci_dev *dev, unsigned long type)
1954{
1955 int pos;
1956 u16 ctrl;
1957
1958 pos = pci_pcie_cap(dev);
1959 if (!pos)
1960 return;
1961
1962 pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &ctrl);
1963 if (type & PCI_EXP_IDO_REQUEST)
1964 ctrl |= PCI_EXP_IDO_REQ_EN;
1965 if (type & PCI_EXP_IDO_COMPLETION)
1966 ctrl |= PCI_EXP_IDO_CMP_EN;
1967 pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, ctrl);
1968}
1969EXPORT_SYMBOL(pci_enable_ido);
1970
1971/**
1972 * pci_disable_ido - disable ID-based ordering on a device
1973 * @dev: the PCI device
1974 * @type: which types of IDO to disable
1975 */
1976void pci_disable_ido(struct pci_dev *dev, unsigned long type)
1977{
1978 int pos;
1979 u16 ctrl;
1980
1981 if (!pci_is_pcie(dev))
1982 return;
1983
1984 pos = pci_pcie_cap(dev);
1985 if (!pos)
1986 return;
1987
1988 pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &ctrl);
1989 if (type & PCI_EXP_IDO_REQUEST)
1990 ctrl &= ~PCI_EXP_IDO_REQ_EN;
1991 if (type & PCI_EXP_IDO_COMPLETION)
1992 ctrl &= ~PCI_EXP_IDO_CMP_EN;
1993 pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, ctrl);
1994}
1995EXPORT_SYMBOL(pci_disable_ido);
1996
1997/**
1998 * pci_enable_obff - enable optimized buffer flush/fill
1999 * @dev: PCI device
2000 * @type: type of signaling to use
2001 *
2002 * Try to enable @type OBFF signaling on @dev. It will try using WAKE#
2003 * signaling if possible, falling back to message signaling only if
2004 * WAKE# isn't supported. @type should indicate whether the PCIe link
2005 * be brought out of L0s or L1 to send the message. It should be either
2006 * %PCI_EXP_OBFF_SIGNAL_ALWAYS or %PCI_OBFF_SIGNAL_L0.
2007 *
2008 * If your device can benefit from receiving all messages, even at the
2009 * power cost of bringing the link back up from a low power state, use
2010 * %PCI_EXP_OBFF_SIGNAL_ALWAYS. Otherwise, use %PCI_OBFF_SIGNAL_L0 (the
2011 * preferred type).
2012 *
2013 * RETURNS:
2014 * Zero on success, appropriate error number on failure.
2015 */
2016int pci_enable_obff(struct pci_dev *dev, enum pci_obff_signal_type type)
2017{
2018 int pos;
2019 u32 cap;
2020 u16 ctrl;
2021 int ret;
2022
2023 if (!pci_is_pcie(dev))
2024 return -ENOTSUPP;
2025
2026 pos = pci_pcie_cap(dev);
2027 if (!pos)
2028 return -ENOTSUPP;
2029
2030 pci_read_config_dword(dev, pos + PCI_EXP_DEVCAP2, &cap);
2031 if (!(cap & PCI_EXP_OBFF_MASK))
2032 return -ENOTSUPP; /* no OBFF support at all */
2033
2034 /* Make sure the topology supports OBFF as well */
2035 if (dev->bus) {
2036 ret = pci_enable_obff(dev->bus->self, type);
2037 if (ret)
2038 return ret;
2039 }
2040
2041 pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &ctrl);
2042 if (cap & PCI_EXP_OBFF_WAKE)
2043 ctrl |= PCI_EXP_OBFF_WAKE_EN;
2044 else {
2045 switch (type) {
2046 case PCI_EXP_OBFF_SIGNAL_L0:
2047 if (!(ctrl & PCI_EXP_OBFF_WAKE_EN))
2048 ctrl |= PCI_EXP_OBFF_MSGA_EN;
2049 break;
2050 case PCI_EXP_OBFF_SIGNAL_ALWAYS:
2051 ctrl &= ~PCI_EXP_OBFF_WAKE_EN;
2052 ctrl |= PCI_EXP_OBFF_MSGB_EN;
2053 break;
2054 default:
2055 WARN(1, "bad OBFF signal type\n");
2056 return -ENOTSUPP;
2057 }
2058 }
2059 pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, ctrl);
2060
2061 return 0;
2062}
2063EXPORT_SYMBOL(pci_enable_obff);
2064
2065/**
2066 * pci_disable_obff - disable optimized buffer flush/fill
2067 * @dev: PCI device
2068 *
2069 * Disable OBFF on @dev.
2070 */
2071void pci_disable_obff(struct pci_dev *dev)
2072{
2073 int pos;
2074 u16 ctrl;
2075
2076 if (!pci_is_pcie(dev))
2077 return;
2078
2079 pos = pci_pcie_cap(dev);
2080 if (!pos)
2081 return;
2082
2083 pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &ctrl);
2084 ctrl &= ~PCI_EXP_OBFF_WAKE_EN;
2085 pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, ctrl);
2086}
2087EXPORT_SYMBOL(pci_disable_obff);
2088
2089/**
2090 * pci_ltr_supported - check whether a device supports LTR
2091 * @dev: PCI device
2092 *
2093 * RETURNS:
2094 * True if @dev supports latency tolerance reporting, false otherwise.
2095 */
2096bool pci_ltr_supported(struct pci_dev *dev)
2097{
2098 int pos;
2099 u32 cap;
2100
2101 if (!pci_is_pcie(dev))
2102 return false;
2103
2104 pos = pci_pcie_cap(dev);
2105 if (!pos)
2106 return false;
2107
2108 pci_read_config_dword(dev, pos + PCI_EXP_DEVCAP2, &cap);
2109
2110 return cap & PCI_EXP_DEVCAP2_LTR;
2111}
2112EXPORT_SYMBOL(pci_ltr_supported);
2113
2114/**
2115 * pci_enable_ltr - enable latency tolerance reporting
2116 * @dev: PCI device
2117 *
2118 * Enable LTR on @dev if possible, which means enabling it first on
2119 * upstream ports.
2120 *
2121 * RETURNS:
2122 * Zero on success, errno on failure.
2123 */
2124int pci_enable_ltr(struct pci_dev *dev)
2125{
2126 int pos;
2127 u16 ctrl;
2128 int ret;
2129
2130 if (!pci_ltr_supported(dev))
2131 return -ENOTSUPP;
2132
2133 pos = pci_pcie_cap(dev);
2134 if (!pos)
2135 return -ENOTSUPP;
2136
2137 /* Only primary function can enable/disable LTR */
2138 if (PCI_FUNC(dev->devfn) != 0)
2139 return -EINVAL;
2140
2141 /* Enable upstream ports first */
2142 if (dev->bus) {
2143 ret = pci_enable_ltr(dev->bus->self);
2144 if (ret)
2145 return ret;
2146 }
2147
2148 pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &ctrl);
2149 ctrl |= PCI_EXP_LTR_EN;
2150 pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, ctrl);
2151
2152 return 0;
2153}
2154EXPORT_SYMBOL(pci_enable_ltr);
2155
2156/**
2157 * pci_disable_ltr - disable latency tolerance reporting
2158 * @dev: PCI device
2159 */
2160void pci_disable_ltr(struct pci_dev *dev)
2161{
2162 int pos;
2163 u16 ctrl;
2164
2165 if (!pci_ltr_supported(dev))
2166 return;
2167
2168 pos = pci_pcie_cap(dev);
2169 if (!pos)
2170 return;
2171
2172 /* Only primary function can enable/disable LTR */
2173 if (PCI_FUNC(dev->devfn) != 0)
2174 return;
2175
2176 pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &ctrl);
2177 ctrl &= ~PCI_EXP_LTR_EN;
2178 pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, ctrl);
2179}
2180EXPORT_SYMBOL(pci_disable_ltr);
2181
2182static int __pci_ltr_scale(int *val)
2183{
2184 int scale = 0;
2185
2186 while (*val > 1023) {
2187 *val = (*val + 31) / 32;
2188 scale++;
2189 }
2190 return scale;
2191}
2192
2193/**
2194 * pci_set_ltr - set LTR latency values
2195 * @dev: PCI device
2196 * @snoop_lat_ns: snoop latency in nanoseconds
2197 * @nosnoop_lat_ns: nosnoop latency in nanoseconds
2198 *
2199 * Figure out the scale and set the LTR values accordingly.
2200 */
2201int pci_set_ltr(struct pci_dev *dev, int snoop_lat_ns, int nosnoop_lat_ns)
2202{
2203 int pos, ret, snoop_scale, nosnoop_scale;
2204 u16 val;
2205
2206 if (!pci_ltr_supported(dev))
2207 return -ENOTSUPP;
2208
2209 snoop_scale = __pci_ltr_scale(&snoop_lat_ns);
2210 nosnoop_scale = __pci_ltr_scale(&nosnoop_lat_ns);
2211
2212 if (snoop_lat_ns > PCI_LTR_VALUE_MASK ||
2213 nosnoop_lat_ns > PCI_LTR_VALUE_MASK)
2214 return -EINVAL;
2215
2216 if ((snoop_scale > (PCI_LTR_SCALE_MASK >> PCI_LTR_SCALE_SHIFT)) ||
2217 (nosnoop_scale > (PCI_LTR_SCALE_MASK >> PCI_LTR_SCALE_SHIFT)))
2218 return -EINVAL;
2219
2220 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR);
2221 if (!pos)
2222 return -ENOTSUPP;
2223
2224 val = (snoop_scale << PCI_LTR_SCALE_SHIFT) | snoop_lat_ns;
2225 ret = pci_write_config_word(dev, pos + PCI_LTR_MAX_SNOOP_LAT, val);
2226 if (ret != 4)
2227 return -EIO;
2228
2229 val = (nosnoop_scale << PCI_LTR_SCALE_SHIFT) | nosnoop_lat_ns;
2230 ret = pci_write_config_word(dev, pos + PCI_LTR_MAX_NOSNOOP_LAT, val);
2231 if (ret != 4)
2232 return -EIO;
2233
2234 return 0;
2235}
2236EXPORT_SYMBOL(pci_set_ltr);
2237
2238static int pci_acs_enable;
2239
2240/**
2241 * pci_request_acs - ask for ACS to be enabled if supported
2242 */
2243void pci_request_acs(void)
2244{
2245 pci_acs_enable = 1;
2246}
2247
2248/**
2249 * pci_enable_acs - enable ACS if hardware support it
2250 * @dev: the PCI device
2251 */
2252void pci_enable_acs(struct pci_dev *dev)
2253{
2254 int pos;
2255 u16 cap;
2256 u16 ctrl;
2257
2258 if (!pci_acs_enable)
2259 return;
2260
2261 if (!pci_is_pcie(dev))
2262 return;
2263
2264 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS);
2265 if (!pos)
2266 return;
2267
2268 pci_read_config_word(dev, pos + PCI_ACS_CAP, &cap);
2269 pci_read_config_word(dev, pos + PCI_ACS_CTRL, &ctrl);
2270
2271 /* Source Validation */
2272 ctrl |= (cap & PCI_ACS_SV);
2273
2274 /* P2P Request Redirect */
2275 ctrl |= (cap & PCI_ACS_RR);
2276
2277 /* P2P Completion Redirect */
2278 ctrl |= (cap & PCI_ACS_CR);
2279
2280 /* Upstream Forwarding */
2281 ctrl |= (cap & PCI_ACS_UF);
2282
2283 pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl);
2284}
2285
2286/**
2287 * pci_swizzle_interrupt_pin - swizzle INTx for device behind bridge
2288 * @dev: the PCI device
2289 * @pin: the INTx pin (1=INTA, 2=INTB, 3=INTD, 4=INTD)
2290 *
2291 * Perform INTx swizzling for a device behind one level of bridge. This is
2292 * required by section 9.1 of the PCI-to-PCI bridge specification for devices
2293 * behind bridges on add-in cards. For devices with ARI enabled, the slot
2294 * number is always 0 (see the Implementation Note in section 2.2.8.1 of
2295 * the PCI Express Base Specification, Revision 2.1)
2296 */
2297u8 pci_swizzle_interrupt_pin(struct pci_dev *dev, u8 pin)
2298{
2299 int slot;
2300
2301 if (pci_ari_enabled(dev->bus))
2302 slot = 0;
2303 else
2304 slot = PCI_SLOT(dev->devfn);
2305
2306 return (((pin - 1) + slot) % 4) + 1;
2307}
2308
2309int
2310pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge)
2311{
2312 u8 pin;
2313
2314 pin = dev->pin;
2315 if (!pin)
2316 return -1;
2317
2318 while (!pci_is_root_bus(dev->bus)) {
2319 pin = pci_swizzle_interrupt_pin(dev, pin);
2320 dev = dev->bus->self;
2321 }
2322 *bridge = dev;
2323 return pin;
2324}
2325
2326/**
2327 * pci_common_swizzle - swizzle INTx all the way to root bridge
2328 * @dev: the PCI device
2329 * @pinp: pointer to the INTx pin value (1=INTA, 2=INTB, 3=INTD, 4=INTD)
2330 *
2331 * Perform INTx swizzling for a device. This traverses through all PCI-to-PCI
2332 * bridges all the way up to a PCI root bus.
2333 */
2334u8 pci_common_swizzle(struct pci_dev *dev, u8 *pinp)
2335{
2336 u8 pin = *pinp;
2337
2338 while (!pci_is_root_bus(dev->bus)) {
2339 pin = pci_swizzle_interrupt_pin(dev, pin);
2340 dev = dev->bus->self;
2341 }
2342 *pinp = pin;
2343 return PCI_SLOT(dev->devfn);
2344}
2345
2346/**
2347 * pci_release_region - Release a PCI bar
2348 * @pdev: PCI device whose resources were previously reserved by pci_request_region
2349 * @bar: BAR to release
2350 *
2351 * Releases the PCI I/O and memory resources previously reserved by a
2352 * successful call to pci_request_region. Call this function only
2353 * after all use of the PCI regions has ceased.
2354 */
2355void pci_release_region(struct pci_dev *pdev, int bar)
2356{
2357 struct pci_devres *dr;
2358
2359 if (pci_resource_len(pdev, bar) == 0)
2360 return;
2361 if (pci_resource_flags(pdev, bar) & IORESOURCE_IO)
2362 release_region(pci_resource_start(pdev, bar),
2363 pci_resource_len(pdev, bar));
2364 else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM)
2365 release_mem_region(pci_resource_start(pdev, bar),
2366 pci_resource_len(pdev, bar));
2367
2368 dr = find_pci_dr(pdev);
2369 if (dr)
2370 dr->region_mask &= ~(1 << bar);
2371}
2372
2373/**
2374 * __pci_request_region - Reserved PCI I/O and memory resource
2375 * @pdev: PCI device whose resources are to be reserved
2376 * @bar: BAR to be reserved
2377 * @res_name: Name to be associated with resource.
2378 * @exclusive: whether the region access is exclusive or not
2379 *
2380 * Mark the PCI region associated with PCI device @pdev BR @bar as
2381 * being reserved by owner @res_name. Do not access any
2382 * address inside the PCI regions unless this call returns
2383 * successfully.
2384 *
2385 * If @exclusive is set, then the region is marked so that userspace
2386 * is explicitly not allowed to map the resource via /dev/mem or
2387 * sysfs MMIO access.
2388 *
2389 * Returns 0 on success, or %EBUSY on error. A warning
2390 * message is also printed on failure.
2391 */
2392static int __pci_request_region(struct pci_dev *pdev, int bar, const char *res_name,
2393 int exclusive)
2394{
2395 struct pci_devres *dr;
2396
2397 if (pci_resource_len(pdev, bar) == 0)
2398 return 0;
2399
2400 if (pci_resource_flags(pdev, bar) & IORESOURCE_IO) {
2401 if (!request_region(pci_resource_start(pdev, bar),
2402 pci_resource_len(pdev, bar), res_name))
2403 goto err_out;
2404 }
2405 else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM) {
2406 if (!__request_mem_region(pci_resource_start(pdev, bar),
2407 pci_resource_len(pdev, bar), res_name,
2408 exclusive))
2409 goto err_out;
2410 }
2411
2412 dr = find_pci_dr(pdev);
2413 if (dr)
2414 dr->region_mask |= 1 << bar;
2415
2416 return 0;
2417
2418err_out:
2419 dev_warn(&pdev->dev, "BAR %d: can't reserve %pR\n", bar,
2420 &pdev->resource[bar]);
2421 return -EBUSY;
2422}
2423
2424/**
2425 * pci_request_region - Reserve PCI I/O and memory resource
2426 * @pdev: PCI device whose resources are to be reserved
2427 * @bar: BAR to be reserved
2428 * @res_name: Name to be associated with resource
2429 *
2430 * Mark the PCI region associated with PCI device @pdev BAR @bar as
2431 * being reserved by owner @res_name. Do not access any
2432 * address inside the PCI regions unless this call returns
2433 * successfully.
2434 *
2435 * Returns 0 on success, or %EBUSY on error. A warning
2436 * message is also printed on failure.
2437 */
2438int pci_request_region(struct pci_dev *pdev, int bar, const char *res_name)
2439{
2440 return __pci_request_region(pdev, bar, res_name, 0);
2441}
2442
2443/**
2444 * pci_request_region_exclusive - Reserved PCI I/O and memory resource
2445 * @pdev: PCI device whose resources are to be reserved
2446 * @bar: BAR to be reserved
2447 * @res_name: Name to be associated with resource.
2448 *
2449 * Mark the PCI region associated with PCI device @pdev BR @bar as
2450 * being reserved by owner @res_name. Do not access any
2451 * address inside the PCI regions unless this call returns
2452 * successfully.
2453 *
2454 * Returns 0 on success, or %EBUSY on error. A warning
2455 * message is also printed on failure.
2456 *
2457 * The key difference that _exclusive makes it that userspace is
2458 * explicitly not allowed to map the resource via /dev/mem or
2459 * sysfs.
2460 */
2461int pci_request_region_exclusive(struct pci_dev *pdev, int bar, const char *res_name)
2462{
2463 return __pci_request_region(pdev, bar, res_name, IORESOURCE_EXCLUSIVE);
2464}
2465/**
2466 * pci_release_selected_regions - Release selected PCI I/O and memory resources
2467 * @pdev: PCI device whose resources were previously reserved
2468 * @bars: Bitmask of BARs to be released
2469 *
2470 * Release selected PCI I/O and memory resources previously reserved.
2471 * Call this function only after all use of the PCI regions has ceased.
2472 */
2473void pci_release_selected_regions(struct pci_dev *pdev, int bars)
2474{
2475 int i;
2476
2477 for (i = 0; i < 6; i++)
2478 if (bars & (1 << i))
2479 pci_release_region(pdev, i);
2480}
2481
2482int __pci_request_selected_regions(struct pci_dev *pdev, int bars,
2483 const char *res_name, int excl)
2484{
2485 int i;
2486
2487 for (i = 0; i < 6; i++)
2488 if (bars & (1 << i))
2489 if (__pci_request_region(pdev, i, res_name, excl))
2490 goto err_out;
2491 return 0;
2492
2493err_out:
2494 while(--i >= 0)
2495 if (bars & (1 << i))
2496 pci_release_region(pdev, i);
2497
2498 return -EBUSY;
2499}
2500
2501
2502/**
2503 * pci_request_selected_regions - Reserve selected PCI I/O and memory resources
2504 * @pdev: PCI device whose resources are to be reserved
2505 * @bars: Bitmask of BARs to be requested
2506 * @res_name: Name to be associated with resource
2507 */
2508int pci_request_selected_regions(struct pci_dev *pdev, int bars,
2509 const char *res_name)
2510{
2511 return __pci_request_selected_regions(pdev, bars, res_name, 0);
2512}
2513
2514int pci_request_selected_regions_exclusive(struct pci_dev *pdev,
2515 int bars, const char *res_name)
2516{
2517 return __pci_request_selected_regions(pdev, bars, res_name,
2518 IORESOURCE_EXCLUSIVE);
2519}
2520
2521/**
2522 * pci_release_regions - Release reserved PCI I/O and memory resources
2523 * @pdev: PCI device whose resources were previously reserved by pci_request_regions
2524 *
2525 * Releases all PCI I/O and memory resources previously reserved by a
2526 * successful call to pci_request_regions. Call this function only
2527 * after all use of the PCI regions has ceased.
2528 */
2529
2530void pci_release_regions(struct pci_dev *pdev)
2531{
2532 pci_release_selected_regions(pdev, (1 << 6) - 1);
2533}
2534
2535/**
2536 * pci_request_regions - Reserved PCI I/O and memory resources
2537 * @pdev: PCI device whose resources are to be reserved
2538 * @res_name: Name to be associated with resource.
2539 *
2540 * Mark all PCI regions associated with PCI device @pdev as
2541 * being reserved by owner @res_name. Do not access any
2542 * address inside the PCI regions unless this call returns
2543 * successfully.
2544 *
2545 * Returns 0 on success, or %EBUSY on error. A warning
2546 * message is also printed on failure.
2547 */
2548int pci_request_regions(struct pci_dev *pdev, const char *res_name)
2549{
2550 return pci_request_selected_regions(pdev, ((1 << 6) - 1), res_name);
2551}
2552
2553/**
2554 * pci_request_regions_exclusive - Reserved PCI I/O and memory resources
2555 * @pdev: PCI device whose resources are to be reserved
2556 * @res_name: Name to be associated with resource.
2557 *
2558 * Mark all PCI regions associated with PCI device @pdev as
2559 * being reserved by owner @res_name. Do not access any
2560 * address inside the PCI regions unless this call returns
2561 * successfully.
2562 *
2563 * pci_request_regions_exclusive() will mark the region so that
2564 * /dev/mem and the sysfs MMIO access will not be allowed.
2565 *
2566 * Returns 0 on success, or %EBUSY on error. A warning
2567 * message is also printed on failure.
2568 */
2569int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name)
2570{
2571 return pci_request_selected_regions_exclusive(pdev,
2572 ((1 << 6) - 1), res_name);
2573}
2574
2575static void __pci_set_master(struct pci_dev *dev, bool enable)
2576{
2577 u16 old_cmd, cmd;
2578
2579 pci_read_config_word(dev, PCI_COMMAND, &old_cmd);
2580 if (enable)
2581 cmd = old_cmd | PCI_COMMAND_MASTER;
2582 else
2583 cmd = old_cmd & ~PCI_COMMAND_MASTER;
2584 if (cmd != old_cmd) {
2585 dev_dbg(&dev->dev, "%s bus mastering\n",
2586 enable ? "enabling" : "disabling");
2587 pci_write_config_word(dev, PCI_COMMAND, cmd);
2588 }
2589 dev->is_busmaster = enable;
2590}
2591
2592/**
2593 * pci_set_master - enables bus-mastering for device dev
2594 * @dev: the PCI device to enable
2595 *
2596 * Enables bus-mastering on the device and calls pcibios_set_master()
2597 * to do the needed arch specific settings.
2598 */
2599void pci_set_master(struct pci_dev *dev)
2600{
2601 __pci_set_master(dev, true);
2602 pcibios_set_master(dev);
2603}
2604
2605/**
2606 * pci_clear_master - disables bus-mastering for device dev
2607 * @dev: the PCI device to disable
2608 */
2609void pci_clear_master(struct pci_dev *dev)
2610{
2611 __pci_set_master(dev, false);
2612}
2613
2614/**
2615 * pci_set_cacheline_size - ensure the CACHE_LINE_SIZE register is programmed
2616 * @dev: the PCI device for which MWI is to be enabled
2617 *
2618 * Helper function for pci_set_mwi.
2619 * Originally copied from drivers/net/acenic.c.
2620 * Copyright 1998-2001 by Jes Sorensen, <jes@trained-monkey.org>.
2621 *
2622 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2623 */
2624int pci_set_cacheline_size(struct pci_dev *dev)
2625{
2626 u8 cacheline_size;
2627
2628 if (!pci_cache_line_size)
2629 return -EINVAL;
2630
2631 /* Validate current setting: the PCI_CACHE_LINE_SIZE must be
2632 equal to or multiple of the right value. */
2633 pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
2634 if (cacheline_size >= pci_cache_line_size &&
2635 (cacheline_size % pci_cache_line_size) == 0)
2636 return 0;
2637
2638 /* Write the correct value. */
2639 pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, pci_cache_line_size);
2640 /* Read it back. */
2641 pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
2642 if (cacheline_size == pci_cache_line_size)
2643 return 0;
2644
2645 dev_printk(KERN_DEBUG, &dev->dev, "cache line size of %d is not "
2646 "supported\n", pci_cache_line_size << 2);
2647
2648 return -EINVAL;
2649}
2650EXPORT_SYMBOL_GPL(pci_set_cacheline_size);
2651
2652#ifdef PCI_DISABLE_MWI
2653int pci_set_mwi(struct pci_dev *dev)
2654{
2655 return 0;
2656}
2657
2658int pci_try_set_mwi(struct pci_dev *dev)
2659{
2660 return 0;
2661}
2662
2663void pci_clear_mwi(struct pci_dev *dev)
2664{
2665}
2666
2667#else
2668
2669/**
2670 * pci_set_mwi - enables memory-write-invalidate PCI transaction
2671 * @dev: the PCI device for which MWI is enabled
2672 *
2673 * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND.
2674 *
2675 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2676 */
2677int
2678pci_set_mwi(struct pci_dev *dev)
2679{
2680 int rc;
2681 u16 cmd;
2682
2683 rc = pci_set_cacheline_size(dev);
2684 if (rc)
2685 return rc;
2686
2687 pci_read_config_word(dev, PCI_COMMAND, &cmd);
2688 if (! (cmd & PCI_COMMAND_INVALIDATE)) {
2689 dev_dbg(&dev->dev, "enabling Mem-Wr-Inval\n");
2690 cmd |= PCI_COMMAND_INVALIDATE;
2691 pci_write_config_word(dev, PCI_COMMAND, cmd);
2692 }
2693
2694 return 0;
2695}
2696
2697/**
2698 * pci_try_set_mwi - enables memory-write-invalidate PCI transaction
2699 * @dev: the PCI device for which MWI is enabled
2700 *
2701 * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND.
2702 * Callers are not required to check the return value.
2703 *
2704 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2705 */
2706int pci_try_set_mwi(struct pci_dev *dev)
2707{
2708 int rc = pci_set_mwi(dev);
2709 return rc;
2710}
2711
2712/**
2713 * pci_clear_mwi - disables Memory-Write-Invalidate for device dev
2714 * @dev: the PCI device to disable
2715 *
2716 * Disables PCI Memory-Write-Invalidate transaction on the device
2717 */
2718void
2719pci_clear_mwi(struct pci_dev *dev)
2720{
2721 u16 cmd;
2722
2723 pci_read_config_word(dev, PCI_COMMAND, &cmd);
2724 if (cmd & PCI_COMMAND_INVALIDATE) {
2725 cmd &= ~PCI_COMMAND_INVALIDATE;
2726 pci_write_config_word(dev, PCI_COMMAND, cmd);
2727 }
2728}
2729#endif /* ! PCI_DISABLE_MWI */
2730
2731/**
2732 * pci_intx - enables/disables PCI INTx for device dev
2733 * @pdev: the PCI device to operate on
2734 * @enable: boolean: whether to enable or disable PCI INTx
2735 *
2736 * Enables/disables PCI INTx for device dev
2737 */
2738void
2739pci_intx(struct pci_dev *pdev, int enable)
2740{
2741 u16 pci_command, new;
2742
2743 pci_read_config_word(pdev, PCI_COMMAND, &pci_command);
2744
2745 if (enable) {
2746 new = pci_command & ~PCI_COMMAND_INTX_DISABLE;
2747 } else {
2748 new = pci_command | PCI_COMMAND_INTX_DISABLE;
2749 }
2750
2751 if (new != pci_command) {
2752 struct pci_devres *dr;
2753
2754 pci_write_config_word(pdev, PCI_COMMAND, new);
2755
2756 dr = find_pci_dr(pdev);
2757 if (dr && !dr->restore_intx) {
2758 dr->restore_intx = 1;
2759 dr->orig_intx = !enable;
2760 }
2761 }
2762}
2763
2764/**
2765 * pci_msi_off - disables any msi or msix capabilities
2766 * @dev: the PCI device to operate on
2767 *
2768 * If you want to use msi see pci_enable_msi and friends.
2769 * This is a lower level primitive that allows us to disable
2770 * msi operation at the device level.
2771 */
2772void pci_msi_off(struct pci_dev *dev)
2773{
2774 int pos;
2775 u16 control;
2776
2777 pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
2778 if (pos) {
2779 pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control);
2780 control &= ~PCI_MSI_FLAGS_ENABLE;
2781 pci_write_config_word(dev, pos + PCI_MSI_FLAGS, control);
2782 }
2783 pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
2784 if (pos) {
2785 pci_read_config_word(dev, pos + PCI_MSIX_FLAGS, &control);
2786 control &= ~PCI_MSIX_FLAGS_ENABLE;
2787 pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control);
2788 }
2789}
2790EXPORT_SYMBOL_GPL(pci_msi_off);
2791
2792int pci_set_dma_max_seg_size(struct pci_dev *dev, unsigned int size)
2793{
2794 return dma_set_max_seg_size(&dev->dev, size);
2795}
2796EXPORT_SYMBOL(pci_set_dma_max_seg_size);
2797
2798int pci_set_dma_seg_boundary(struct pci_dev *dev, unsigned long mask)
2799{
2800 return dma_set_seg_boundary(&dev->dev, mask);
2801}
2802EXPORT_SYMBOL(pci_set_dma_seg_boundary);
2803
2804static int pcie_flr(struct pci_dev *dev, int probe)
2805{
2806 int i;
2807 int pos;
2808 u32 cap;
2809 u16 status, control;
2810
2811 pos = pci_pcie_cap(dev);
2812 if (!pos)
2813 return -ENOTTY;
2814
2815 pci_read_config_dword(dev, pos + PCI_EXP_DEVCAP, &cap);
2816 if (!(cap & PCI_EXP_DEVCAP_FLR))
2817 return -ENOTTY;
2818
2819 if (probe)
2820 return 0;
2821
2822 /* Wait for Transaction Pending bit clean */
2823 for (i = 0; i < 4; i++) {
2824 if (i)
2825 msleep((1 << (i - 1)) * 100);
2826
2827 pci_read_config_word(dev, pos + PCI_EXP_DEVSTA, &status);
2828 if (!(status & PCI_EXP_DEVSTA_TRPND))
2829 goto clear;
2830 }
2831
2832 dev_err(&dev->dev, "transaction is not cleared; "
2833 "proceeding with reset anyway\n");
2834
2835clear:
2836 pci_read_config_word(dev, pos + PCI_EXP_DEVCTL, &control);
2837 control |= PCI_EXP_DEVCTL_BCR_FLR;
2838 pci_write_config_word(dev, pos + PCI_EXP_DEVCTL, control);
2839
2840 msleep(100);
2841
2842 return 0;
2843}
2844
2845static int pci_af_flr(struct pci_dev *dev, int probe)
2846{
2847 int i;
2848 int pos;
2849 u8 cap;
2850 u8 status;
2851
2852 pos = pci_find_capability(dev, PCI_CAP_ID_AF);
2853 if (!pos)
2854 return -ENOTTY;
2855
2856 pci_read_config_byte(dev, pos + PCI_AF_CAP, &cap);
2857 if (!(cap & PCI_AF_CAP_TP) || !(cap & PCI_AF_CAP_FLR))
2858 return -ENOTTY;
2859
2860 if (probe)
2861 return 0;
2862
2863 /* Wait for Transaction Pending bit clean */
2864 for (i = 0; i < 4; i++) {
2865 if (i)
2866 msleep((1 << (i - 1)) * 100);
2867
2868 pci_read_config_byte(dev, pos + PCI_AF_STATUS, &status);
2869 if (!(status & PCI_AF_STATUS_TP))
2870 goto clear;
2871 }
2872
2873 dev_err(&dev->dev, "transaction is not cleared; "
2874 "proceeding with reset anyway\n");
2875
2876clear:
2877 pci_write_config_byte(dev, pos + PCI_AF_CTRL, PCI_AF_CTRL_FLR);
2878 msleep(100);
2879
2880 return 0;
2881}
2882
2883/**
2884 * pci_pm_reset - Put device into PCI_D3 and back into PCI_D0.
2885 * @dev: Device to reset.
2886 * @probe: If set, only check if the device can be reset this way.
2887 *
2888 * If @dev supports native PCI PM and its PCI_PM_CTRL_NO_SOFT_RESET flag is
2889 * unset, it will be reinitialized internally when going from PCI_D3hot to
2890 * PCI_D0. If that's the case and the device is not in a low-power state
2891 * already, force it into PCI_D3hot and back to PCI_D0, causing it to be reset.
2892 *
2893 * NOTE: This causes the caller to sleep for twice the device power transition
2894 * cooldown period, which for the D0->D3hot and D3hot->D0 transitions is 10 ms
2895 * by devault (i.e. unless the @dev's d3_delay field has a different value).
2896 * Moreover, only devices in D0 can be reset by this function.
2897 */
2898static int pci_pm_reset(struct pci_dev *dev, int probe)
2899{
2900 u16 csr;
2901
2902 if (!dev->pm_cap)
2903 return -ENOTTY;
2904
2905 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &csr);
2906 if (csr & PCI_PM_CTRL_NO_SOFT_RESET)
2907 return -ENOTTY;
2908
2909 if (probe)
2910 return 0;
2911
2912 if (dev->current_state != PCI_D0)
2913 return -EINVAL;
2914
2915 csr &= ~PCI_PM_CTRL_STATE_MASK;
2916 csr |= PCI_D3hot;
2917 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);
2918 pci_dev_d3_sleep(dev);
2919
2920 csr &= ~PCI_PM_CTRL_STATE_MASK;
2921 csr |= PCI_D0;
2922 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);
2923 pci_dev_d3_sleep(dev);
2924
2925 return 0;
2926}
2927
2928static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
2929{
2930 u16 ctrl;
2931 struct pci_dev *pdev;
2932
2933 if (pci_is_root_bus(dev->bus) || dev->subordinate || !dev->bus->self)
2934 return -ENOTTY;
2935
2936 list_for_each_entry(pdev, &dev->bus->devices, bus_list)
2937 if (pdev != dev)
2938 return -ENOTTY;
2939
2940 if (probe)
2941 return 0;
2942
2943 pci_read_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, &ctrl);
2944 ctrl |= PCI_BRIDGE_CTL_BUS_RESET;
2945 pci_write_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, ctrl);
2946 msleep(100);
2947
2948 ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET;
2949 pci_write_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, ctrl);
2950 msleep(100);
2951
2952 return 0;
2953}
2954
2955static int pci_dev_reset(struct pci_dev *dev, int probe)
2956{
2957 int rc;
2958
2959 might_sleep();
2960
2961 if (!probe) {
2962 pci_block_user_cfg_access(dev);
2963 /* block PM suspend, driver probe, etc. */
2964 device_lock(&dev->dev);
2965 }
2966
2967 rc = pci_dev_specific_reset(dev, probe);
2968 if (rc != -ENOTTY)
2969 goto done;
2970
2971 rc = pcie_flr(dev, probe);
2972 if (rc != -ENOTTY)
2973 goto done;
2974
2975 rc = pci_af_flr(dev, probe);
2976 if (rc != -ENOTTY)
2977 goto done;
2978
2979 rc = pci_pm_reset(dev, probe);
2980 if (rc != -ENOTTY)
2981 goto done;
2982
2983 rc = pci_parent_bus_reset(dev, probe);
2984done:
2985 if (!probe) {
2986 device_unlock(&dev->dev);
2987 pci_unblock_user_cfg_access(dev);
2988 }
2989
2990 return rc;
2991}
2992
2993/**
2994 * __pci_reset_function - reset a PCI device function
2995 * @dev: PCI device to reset
2996 *
2997 * Some devices allow an individual function to be reset without affecting
2998 * other functions in the same device. The PCI device must be responsive
2999 * to PCI config space in order to use this function.
3000 *
3001 * The device function is presumed to be unused when this function is called.
3002 * Resetting the device will make the contents of PCI configuration space
3003 * random, so any caller of this must be prepared to reinitialise the
3004 * device including MSI, bus mastering, BARs, decoding IO and memory spaces,
3005 * etc.
3006 *
3007 * Returns 0 if the device function was successfully reset or negative if the
3008 * device doesn't support resetting a single function.
3009 */
3010int __pci_reset_function(struct pci_dev *dev)
3011{
3012 return pci_dev_reset(dev, 0);
3013}
3014EXPORT_SYMBOL_GPL(__pci_reset_function);
3015
3016/**
3017 * pci_probe_reset_function - check whether the device can be safely reset
3018 * @dev: PCI device to reset
3019 *
3020 * Some devices allow an individual function to be reset without affecting
3021 * other functions in the same device. The PCI device must be responsive
3022 * to PCI config space in order to use this function.
3023 *
3024 * Returns 0 if the device function can be reset or negative if the
3025 * device doesn't support resetting a single function.
3026 */
3027int pci_probe_reset_function(struct pci_dev *dev)
3028{
3029 return pci_dev_reset(dev, 1);
3030}
3031
3032/**
3033 * pci_reset_function - quiesce and reset a PCI device function
3034 * @dev: PCI device to reset
3035 *
3036 * Some devices allow an individual function to be reset without affecting
3037 * other functions in the same device. The PCI device must be responsive
3038 * to PCI config space in order to use this function.
3039 *
3040 * This function does not just reset the PCI portion of a device, but
3041 * clears all the state associated with the device. This function differs
3042 * from __pci_reset_function in that it saves and restores device state
3043 * over the reset.
3044 *
3045 * Returns 0 if the device function was successfully reset or negative if the
3046 * device doesn't support resetting a single function.
3047 */
3048int pci_reset_function(struct pci_dev *dev)
3049{
3050 int rc;
3051
3052 rc = pci_dev_reset(dev, 1);
3053 if (rc)
3054 return rc;
3055
3056 pci_save_state(dev);
3057
3058 /*
3059 * both INTx and MSI are disabled after the Interrupt Disable bit
3060 * is set and the Bus Master bit is cleared.
3061 */
3062 pci_write_config_word(dev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
3063
3064 rc = pci_dev_reset(dev, 0);
3065
3066 pci_restore_state(dev);
3067
3068 return rc;
3069}
3070EXPORT_SYMBOL_GPL(pci_reset_function);
3071
3072/**
3073 * pcix_get_max_mmrbc - get PCI-X maximum designed memory read byte count
3074 * @dev: PCI device to query
3075 *
3076 * Returns mmrbc: maximum designed memory read count in bytes
3077 * or appropriate error value.
3078 */
3079int pcix_get_max_mmrbc(struct pci_dev *dev)
3080{
3081 int cap;
3082 u32 stat;
3083
3084 cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
3085 if (!cap)
3086 return -EINVAL;
3087
3088 if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat))
3089 return -EINVAL;
3090
3091 return 512 << ((stat & PCI_X_STATUS_MAX_READ) >> 21);
3092}
3093EXPORT_SYMBOL(pcix_get_max_mmrbc);
3094
3095/**
3096 * pcix_get_mmrbc - get PCI-X maximum memory read byte count
3097 * @dev: PCI device to query
3098 *
3099 * Returns mmrbc: maximum memory read count in bytes
3100 * or appropriate error value.
3101 */
3102int pcix_get_mmrbc(struct pci_dev *dev)
3103{
3104 int cap;
3105 u16 cmd;
3106
3107 cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
3108 if (!cap)
3109 return -EINVAL;
3110
3111 if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd))
3112 return -EINVAL;
3113
3114 return 512 << ((cmd & PCI_X_CMD_MAX_READ) >> 2);
3115}
3116EXPORT_SYMBOL(pcix_get_mmrbc);
3117
3118/**
3119 * pcix_set_mmrbc - set PCI-X maximum memory read byte count
3120 * @dev: PCI device to query
3121 * @mmrbc: maximum memory read count in bytes
3122 * valid values are 512, 1024, 2048, 4096
3123 *
3124 * If possible sets maximum memory read byte count, some bridges have erratas
3125 * that prevent this.
3126 */
3127int pcix_set_mmrbc(struct pci_dev *dev, int mmrbc)
3128{
3129 int cap;
3130 u32 stat, v, o;
3131 u16 cmd;
3132
3133 if (mmrbc < 512 || mmrbc > 4096 || !is_power_of_2(mmrbc))
3134 return -EINVAL;
3135
3136 v = ffs(mmrbc) - 10;
3137
3138 cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
3139 if (!cap)
3140 return -EINVAL;
3141
3142 if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat))
3143 return -EINVAL;
3144
3145 if (v > (stat & PCI_X_STATUS_MAX_READ) >> 21)
3146 return -E2BIG;
3147
3148 if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd))
3149 return -EINVAL;
3150
3151 o = (cmd & PCI_X_CMD_MAX_READ) >> 2;
3152 if (o != v) {
3153 if (v > o && dev->bus &&
3154 (dev->bus->bus_flags & PCI_BUS_FLAGS_NO_MMRBC))
3155 return -EIO;
3156
3157 cmd &= ~PCI_X_CMD_MAX_READ;
3158 cmd |= v << 2;
3159 if (pci_write_config_word(dev, cap + PCI_X_CMD, cmd))
3160 return -EIO;
3161 }
3162 return 0;
3163}
3164EXPORT_SYMBOL(pcix_set_mmrbc);
3165
3166/**
3167 * pcie_get_readrq - get PCI Express read request size
3168 * @dev: PCI device to query
3169 *
3170 * Returns maximum memory read request in bytes
3171 * or appropriate error value.
3172 */
3173int pcie_get_readrq(struct pci_dev *dev)
3174{
3175 int ret, cap;
3176 u16 ctl;
3177
3178 cap = pci_pcie_cap(dev);
3179 if (!cap)
3180 return -EINVAL;
3181
3182 ret = pci_read_config_word(dev, cap + PCI_EXP_DEVCTL, &ctl);
3183 if (!ret)
3184 ret = 128 << ((ctl & PCI_EXP_DEVCTL_READRQ) >> 12);
3185
3186 return ret;
3187}
3188EXPORT_SYMBOL(pcie_get_readrq);
3189
3190/**
3191 * pcie_set_readrq - set PCI Express maximum memory read request
3192 * @dev: PCI device to query
3193 * @rq: maximum memory read count in bytes
3194 * valid values are 128, 256, 512, 1024, 2048, 4096
3195 *
3196 * If possible sets maximum memory read request in bytes
3197 */
3198int pcie_set_readrq(struct pci_dev *dev, int rq)
3199{
3200 int cap, err = -EINVAL;
3201 u16 ctl, v;
3202
3203 if (rq < 128 || rq > 4096 || !is_power_of_2(rq))
3204 goto out;
3205
3206 v = (ffs(rq) - 8) << 12;
3207
3208 cap = pci_pcie_cap(dev);
3209 if (!cap)
3210 goto out;
3211
3212 err = pci_read_config_word(dev, cap + PCI_EXP_DEVCTL, &ctl);
3213 if (err)
3214 goto out;
3215
3216 if ((ctl & PCI_EXP_DEVCTL_READRQ) != v) {
3217 ctl &= ~PCI_EXP_DEVCTL_READRQ;
3218 ctl |= v;
3219 err = pci_write_config_word(dev, cap + PCI_EXP_DEVCTL, ctl);
3220 }
3221
3222out:
3223 return err;
3224}
3225EXPORT_SYMBOL(pcie_set_readrq);
3226
3227/**
3228 * pcie_get_mps - get PCI Express maximum payload size
3229 * @dev: PCI device to query
3230 *
3231 * Returns maximum payload size in bytes
3232 * or appropriate error value.
3233 */
3234int pcie_get_mps(struct pci_dev *dev)
3235{
3236 int ret, cap;
3237 u16 ctl;
3238
3239 cap = pci_pcie_cap(dev);
3240 if (!cap)
3241 return -EINVAL;
3242
3243 ret = pci_read_config_word(dev, cap + PCI_EXP_DEVCTL, &ctl);
3244 if (!ret)
3245 ret = 128 << ((ctl & PCI_EXP_DEVCTL_PAYLOAD) >> 5);
3246
3247 return ret;
3248}
3249
3250/**
3251 * pcie_set_mps - set PCI Express maximum payload size
3252 * @dev: PCI device to query
3253 * @mps: maximum payload size in bytes
3254 * valid values are 128, 256, 512, 1024, 2048, 4096
3255 *
3256 * If possible sets maximum payload size
3257 */
3258int pcie_set_mps(struct pci_dev *dev, int mps)
3259{
3260 int cap, err = -EINVAL;
3261 u16 ctl, v;
3262
3263 if (mps < 128 || mps > 4096 || !is_power_of_2(mps))
3264 goto out;
3265
3266 v = ffs(mps) - 8;
3267 if (v > dev->pcie_mpss)
3268 goto out;
3269 v <<= 5;
3270
3271 cap = pci_pcie_cap(dev);
3272 if (!cap)
3273 goto out;
3274
3275 err = pci_read_config_word(dev, cap + PCI_EXP_DEVCTL, &ctl);
3276 if (err)
3277 goto out;
3278
3279 if ((ctl & PCI_EXP_DEVCTL_PAYLOAD) != v) {
3280 ctl &= ~PCI_EXP_DEVCTL_PAYLOAD;
3281 ctl |= v;
3282 err = pci_write_config_word(dev, cap + PCI_EXP_DEVCTL, ctl);
3283 }
3284out:
3285 return err;
3286}
3287
3288/**
3289 * pci_select_bars - Make BAR mask from the type of resource
3290 * @dev: the PCI device for which BAR mask is made
3291 * @flags: resource type mask to be selected
3292 *
3293 * This helper routine makes bar mask from the type of resource.
3294 */
3295int pci_select_bars(struct pci_dev *dev, unsigned long flags)
3296{
3297 int i, bars = 0;
3298 for (i = 0; i < PCI_NUM_RESOURCES; i++)
3299 if (pci_resource_flags(dev, i) & flags)
3300 bars |= (1 << i);
3301 return bars;
3302}
3303
3304/**
3305 * pci_resource_bar - get position of the BAR associated with a resource
3306 * @dev: the PCI device
3307 * @resno: the resource number
3308 * @type: the BAR type to be filled in
3309 *
3310 * Returns BAR position in config space, or 0 if the BAR is invalid.
3311 */
3312int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type)
3313{
3314 int reg;
3315
3316 if (resno < PCI_ROM_RESOURCE) {
3317 *type = pci_bar_unknown;
3318 return PCI_BASE_ADDRESS_0 + 4 * resno;
3319 } else if (resno == PCI_ROM_RESOURCE) {
3320 *type = pci_bar_mem32;
3321 return dev->rom_base_reg;
3322 } else if (resno < PCI_BRIDGE_RESOURCES) {
3323 /* device specific resource */
3324 reg = pci_iov_resource_bar(dev, resno, type);
3325 if (reg)
3326 return reg;
3327 }
3328
3329 dev_err(&dev->dev, "BAR %d: invalid resource\n", resno);
3330 return 0;
3331}
3332
3333/* Some architectures require additional programming to enable VGA */
3334static arch_set_vga_state_t arch_set_vga_state;
3335
3336void __init pci_register_set_vga_state(arch_set_vga_state_t func)
3337{
3338 arch_set_vga_state = func; /* NULL disables */
3339}
3340
3341static int pci_set_vga_state_arch(struct pci_dev *dev, bool decode,
3342 unsigned int command_bits, u32 flags)
3343{
3344 if (arch_set_vga_state)
3345 return arch_set_vga_state(dev, decode, command_bits,
3346 flags);
3347 return 0;
3348}
3349
3350/**
3351 * pci_set_vga_state - set VGA decode state on device and parents if requested
3352 * @dev: the PCI device
3353 * @decode: true = enable decoding, false = disable decoding
3354 * @command_bits: PCI_COMMAND_IO and/or PCI_COMMAND_MEMORY
3355 * @flags: traverse ancestors and change bridges
3356 * CHANGE_BRIDGE_ONLY / CHANGE_BRIDGE
3357 */
3358int pci_set_vga_state(struct pci_dev *dev, bool decode,
3359 unsigned int command_bits, u32 flags)
3360{
3361 struct pci_bus *bus;
3362 struct pci_dev *bridge;
3363 u16 cmd;
3364 int rc;
3365
3366 WARN_ON((flags & PCI_VGA_STATE_CHANGE_DECODES) & (command_bits & ~(PCI_COMMAND_IO|PCI_COMMAND_MEMORY)));
3367
3368 /* ARCH specific VGA enables */
3369 rc = pci_set_vga_state_arch(dev, decode, command_bits, flags);
3370 if (rc)
3371 return rc;
3372
3373 if (flags & PCI_VGA_STATE_CHANGE_DECODES) {
3374 pci_read_config_word(dev, PCI_COMMAND, &cmd);
3375 if (decode == true)
3376 cmd |= command_bits;
3377 else
3378 cmd &= ~command_bits;
3379 pci_write_config_word(dev, PCI_COMMAND, cmd);
3380 }
3381
3382 if (!(flags & PCI_VGA_STATE_CHANGE_BRIDGE))
3383 return 0;
3384
3385 bus = dev->bus;
3386 while (bus) {
3387 bridge = bus->self;
3388 if (bridge) {
3389 pci_read_config_word(bridge, PCI_BRIDGE_CONTROL,
3390 &cmd);
3391 if (decode == true)
3392 cmd |= PCI_BRIDGE_CTL_VGA;
3393 else
3394 cmd &= ~PCI_BRIDGE_CTL_VGA;
3395 pci_write_config_word(bridge, PCI_BRIDGE_CONTROL,
3396 cmd);
3397 }
3398 bus = bus->parent;
3399 }
3400 return 0;
3401}
3402
3403#define RESOURCE_ALIGNMENT_PARAM_SIZE COMMAND_LINE_SIZE
3404static char resource_alignment_param[RESOURCE_ALIGNMENT_PARAM_SIZE] = {0};
3405static DEFINE_SPINLOCK(resource_alignment_lock);
3406
3407/**
3408 * pci_specified_resource_alignment - get resource alignment specified by user.
3409 * @dev: the PCI device to get
3410 *
3411 * RETURNS: Resource alignment if it is specified.
3412 * Zero if it is not specified.
3413 */
3414resource_size_t pci_specified_resource_alignment(struct pci_dev *dev)
3415{
3416 int seg, bus, slot, func, align_order, count;
3417 resource_size_t align = 0;
3418 char *p;
3419
3420 spin_lock(&resource_alignment_lock);
3421 p = resource_alignment_param;
3422 while (*p) {
3423 count = 0;
3424 if (sscanf(p, "%d%n", &align_order, &count) == 1 &&
3425 p[count] == '@') {
3426 p += count + 1;
3427 } else {
3428 align_order = -1;
3429 }
3430 if (sscanf(p, "%x:%x:%x.%x%n",
3431 &seg, &bus, &slot, &func, &count) != 4) {
3432 seg = 0;
3433 if (sscanf(p, "%x:%x.%x%n",
3434 &bus, &slot, &func, &count) != 3) {
3435 /* Invalid format */
3436 printk(KERN_ERR "PCI: Can't parse resource_alignment parameter: %s\n",
3437 p);
3438 break;
3439 }
3440 }
3441 p += count;
3442 if (seg == pci_domain_nr(dev->bus) &&
3443 bus == dev->bus->number &&
3444 slot == PCI_SLOT(dev->devfn) &&
3445 func == PCI_FUNC(dev->devfn)) {
3446 if (align_order == -1) {
3447 align = PAGE_SIZE;
3448 } else {
3449 align = 1 << align_order;
3450 }
3451 /* Found */
3452 break;
3453 }
3454 if (*p != ';' && *p != ',') {
3455 /* End of param or invalid format */
3456 break;
3457 }
3458 p++;
3459 }
3460 spin_unlock(&resource_alignment_lock);
3461 return align;
3462}
3463
3464/**
3465 * pci_is_reassigndev - check if specified PCI is target device to reassign
3466 * @dev: the PCI device to check
3467 *
3468 * RETURNS: non-zero for PCI device is a target device to reassign,
3469 * or zero is not.
3470 */
3471int pci_is_reassigndev(struct pci_dev *dev)
3472{
3473 return (pci_specified_resource_alignment(dev) != 0);
3474}
3475
3476ssize_t pci_set_resource_alignment_param(const char *buf, size_t count)
3477{
3478 if (count > RESOURCE_ALIGNMENT_PARAM_SIZE - 1)
3479 count = RESOURCE_ALIGNMENT_PARAM_SIZE - 1;
3480 spin_lock(&resource_alignment_lock);
3481 strncpy(resource_alignment_param, buf, count);
3482 resource_alignment_param[count] = '\0';
3483 spin_unlock(&resource_alignment_lock);
3484 return count;
3485}
3486
3487ssize_t pci_get_resource_alignment_param(char *buf, size_t size)
3488{
3489 size_t count;
3490 spin_lock(&resource_alignment_lock);
3491 count = snprintf(buf, size, "%s", resource_alignment_param);
3492 spin_unlock(&resource_alignment_lock);
3493 return count;
3494}
3495
3496static ssize_t pci_resource_alignment_show(struct bus_type *bus, char *buf)
3497{
3498 return pci_get_resource_alignment_param(buf, PAGE_SIZE);
3499}
3500
3501static ssize_t pci_resource_alignment_store(struct bus_type *bus,
3502 const char *buf, size_t count)
3503{
3504 return pci_set_resource_alignment_param(buf, count);
3505}
3506
3507BUS_ATTR(resource_alignment, 0644, pci_resource_alignment_show,
3508 pci_resource_alignment_store);
3509
3510static int __init pci_resource_alignment_sysfs_init(void)
3511{
3512 return bus_create_file(&pci_bus_type,
3513 &bus_attr_resource_alignment);
3514}
3515
3516late_initcall(pci_resource_alignment_sysfs_init);
3517
3518static void __devinit pci_no_domains(void)
3519{
3520#ifdef CONFIG_PCI_DOMAINS
3521 pci_domains_supported = 0;
3522#endif
3523}
3524
3525/**
3526 * pci_ext_cfg_enabled - can we access extended PCI config space?
3527 * @dev: The PCI device of the root bridge.
3528 *
3529 * Returns 1 if we can access PCI extended config space (offsets
3530 * greater than 0xff). This is the default implementation. Architecture
3531 * implementations can override this.
3532 */
3533int __attribute__ ((weak)) pci_ext_cfg_avail(struct pci_dev *dev)
3534{
3535 return 1;
3536}
3537
3538void __weak pci_fixup_cardbus(struct pci_bus *bus)
3539{
3540}
3541EXPORT_SYMBOL(pci_fixup_cardbus);
3542
3543static int __init pci_setup(char *str)
3544{
3545 while (str) {
3546 char *k = strchr(str, ',');
3547 if (k)
3548 *k++ = 0;
3549 if (*str && (str = pcibios_setup(str)) && *str) {
3550 if (!strcmp(str, "nomsi")) {
3551 pci_no_msi();
3552 } else if (!strcmp(str, "noaer")) {
3553 pci_no_aer();
3554 } else if (!strncmp(str, "realloc", 7)) {
3555 pci_realloc();
3556 } else if (!strcmp(str, "nodomains")) {
3557 pci_no_domains();
3558 } else if (!strncmp(str, "cbiosize=", 9)) {
3559 pci_cardbus_io_size = memparse(str + 9, &str);
3560 } else if (!strncmp(str, "cbmemsize=", 10)) {
3561 pci_cardbus_mem_size = memparse(str + 10, &str);
3562 } else if (!strncmp(str, "resource_alignment=", 19)) {
3563 pci_set_resource_alignment_param(str + 19,
3564 strlen(str + 19));
3565 } else if (!strncmp(str, "ecrc=", 5)) {
3566 pcie_ecrc_get_policy(str + 5);
3567 } else if (!strncmp(str, "hpiosize=", 9)) {
3568 pci_hotplug_io_size = memparse(str + 9, &str);
3569 } else if (!strncmp(str, "hpmemsize=", 10)) {
3570 pci_hotplug_mem_size = memparse(str + 10, &str);
3571 } else if (!strncmp(str, "pcie_bus_tune_off", 17)) {
3572 pcie_bus_config = PCIE_BUS_TUNE_OFF;
3573 } else if (!strncmp(str, "pcie_bus_safe", 13)) {
3574 pcie_bus_config = PCIE_BUS_SAFE;
3575 } else if (!strncmp(str, "pcie_bus_perf", 13)) {
3576 pcie_bus_config = PCIE_BUS_PERFORMANCE;
3577 } else if (!strncmp(str, "pcie_bus_peer2peer", 18)) {
3578 pcie_bus_config = PCIE_BUS_PEER2PEER;
3579 } else {
3580 printk(KERN_ERR "PCI: Unknown option `%s'\n",
3581 str);
3582 }
3583 }
3584 str = k;
3585 }
3586 return 0;
3587}
3588early_param("pci", pci_setup);
3589
3590EXPORT_SYMBOL(pci_reenable_device);
3591EXPORT_SYMBOL(pci_enable_device_io);
3592EXPORT_SYMBOL(pci_enable_device_mem);
3593EXPORT_SYMBOL(pci_enable_device);
3594EXPORT_SYMBOL(pcim_enable_device);
3595EXPORT_SYMBOL(pcim_pin_device);
3596EXPORT_SYMBOL(pci_disable_device);
3597EXPORT_SYMBOL(pci_find_capability);
3598EXPORT_SYMBOL(pci_bus_find_capability);
3599EXPORT_SYMBOL(pci_release_regions);
3600EXPORT_SYMBOL(pci_request_regions);
3601EXPORT_SYMBOL(pci_request_regions_exclusive);
3602EXPORT_SYMBOL(pci_release_region);
3603EXPORT_SYMBOL(pci_request_region);
3604EXPORT_SYMBOL(pci_request_region_exclusive);
3605EXPORT_SYMBOL(pci_release_selected_regions);
3606EXPORT_SYMBOL(pci_request_selected_regions);
3607EXPORT_SYMBOL(pci_request_selected_regions_exclusive);
3608EXPORT_SYMBOL(pci_set_master);
3609EXPORT_SYMBOL(pci_clear_master);
3610EXPORT_SYMBOL(pci_set_mwi);
3611EXPORT_SYMBOL(pci_try_set_mwi);
3612EXPORT_SYMBOL(pci_clear_mwi);
3613EXPORT_SYMBOL_GPL(pci_intx);
3614EXPORT_SYMBOL(pci_assign_resource);
3615EXPORT_SYMBOL(pci_find_parent_resource);
3616EXPORT_SYMBOL(pci_select_bars);
3617
3618EXPORT_SYMBOL(pci_set_power_state);
3619EXPORT_SYMBOL(pci_save_state);
3620EXPORT_SYMBOL(pci_restore_state);
3621EXPORT_SYMBOL(pci_pme_capable);
3622EXPORT_SYMBOL(pci_pme_active);
3623EXPORT_SYMBOL(pci_wake_from_d3);
3624EXPORT_SYMBOL(pci_target_state);
3625EXPORT_SYMBOL(pci_prepare_to_sleep);
3626EXPORT_SYMBOL(pci_back_from_sleep);
3627EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * PCI Bus Services, see include/linux/pci.h for further explanation.
4 *
5 * Copyright 1993 -- 1997 Drew Eckhardt, Frederic Potter,
6 * David Mosberger-Tang
7 *
8 * Copyright 1997 -- 2000 Martin Mares <mj@ucw.cz>
9 */
10
11#include <linux/acpi.h>
12#include <linux/kernel.h>
13#include <linux/delay.h>
14#include <linux/dmi.h>
15#include <linux/init.h>
16#include <linux/msi.h>
17#include <linux/of.h>
18#include <linux/pci.h>
19#include <linux/pm.h>
20#include <linux/slab.h>
21#include <linux/module.h>
22#include <linux/spinlock.h>
23#include <linux/string.h>
24#include <linux/log2.h>
25#include <linux/logic_pio.h>
26#include <linux/pm_wakeup.h>
27#include <linux/interrupt.h>
28#include <linux/device.h>
29#include <linux/pm_runtime.h>
30#include <linux/pci_hotplug.h>
31#include <linux/vmalloc.h>
32#include <asm/dma.h>
33#include <linux/aer.h>
34#include <linux/bitfield.h>
35#include "pci.h"
36
37DEFINE_MUTEX(pci_slot_mutex);
38
39const char *pci_power_names[] = {
40 "error", "D0", "D1", "D2", "D3hot", "D3cold", "unknown",
41};
42EXPORT_SYMBOL_GPL(pci_power_names);
43
44#ifdef CONFIG_X86_32
45int isa_dma_bridge_buggy;
46EXPORT_SYMBOL(isa_dma_bridge_buggy);
47#endif
48
49int pci_pci_problems;
50EXPORT_SYMBOL(pci_pci_problems);
51
52unsigned int pci_pm_d3hot_delay;
53
54static void pci_pme_list_scan(struct work_struct *work);
55
56static LIST_HEAD(pci_pme_list);
57static DEFINE_MUTEX(pci_pme_list_mutex);
58static DECLARE_DELAYED_WORK(pci_pme_work, pci_pme_list_scan);
59
60struct pci_pme_device {
61 struct list_head list;
62 struct pci_dev *dev;
63};
64
65#define PME_TIMEOUT 1000 /* How long between PME checks */
66
67static void pci_dev_d3_sleep(struct pci_dev *dev)
68{
69 unsigned int delay_ms = max(dev->d3hot_delay, pci_pm_d3hot_delay);
70 unsigned int upper;
71
72 if (delay_ms) {
73 /* Use a 20% upper bound, 1ms minimum */
74 upper = max(DIV_ROUND_CLOSEST(delay_ms, 5), 1U);
75 usleep_range(delay_ms * USEC_PER_MSEC,
76 (delay_ms + upper) * USEC_PER_MSEC);
77 }
78}
79
80bool pci_reset_supported(struct pci_dev *dev)
81{
82 return dev->reset_methods[0] != 0;
83}
84
85#ifdef CONFIG_PCI_DOMAINS
86int pci_domains_supported = 1;
87#endif
88
89#define DEFAULT_CARDBUS_IO_SIZE (256)
90#define DEFAULT_CARDBUS_MEM_SIZE (64*1024*1024)
91/* pci=cbmemsize=nnM,cbiosize=nn can override this */
92unsigned long pci_cardbus_io_size = DEFAULT_CARDBUS_IO_SIZE;
93unsigned long pci_cardbus_mem_size = DEFAULT_CARDBUS_MEM_SIZE;
94
95#define DEFAULT_HOTPLUG_IO_SIZE (256)
96#define DEFAULT_HOTPLUG_MMIO_SIZE (2*1024*1024)
97#define DEFAULT_HOTPLUG_MMIO_PREF_SIZE (2*1024*1024)
98/* hpiosize=nn can override this */
99unsigned long pci_hotplug_io_size = DEFAULT_HOTPLUG_IO_SIZE;
100/*
101 * pci=hpmmiosize=nnM overrides non-prefetchable MMIO size,
102 * pci=hpmmioprefsize=nnM overrides prefetchable MMIO size;
103 * pci=hpmemsize=nnM overrides both
104 */
105unsigned long pci_hotplug_mmio_size = DEFAULT_HOTPLUG_MMIO_SIZE;
106unsigned long pci_hotplug_mmio_pref_size = DEFAULT_HOTPLUG_MMIO_PREF_SIZE;
107
108#define DEFAULT_HOTPLUG_BUS_SIZE 1
109unsigned long pci_hotplug_bus_size = DEFAULT_HOTPLUG_BUS_SIZE;
110
111
112/* PCIe MPS/MRRS strategy; can be overridden by kernel command-line param */
113#ifdef CONFIG_PCIE_BUS_TUNE_OFF
114enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_TUNE_OFF;
115#elif defined CONFIG_PCIE_BUS_SAFE
116enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_SAFE;
117#elif defined CONFIG_PCIE_BUS_PERFORMANCE
118enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_PERFORMANCE;
119#elif defined CONFIG_PCIE_BUS_PEER2PEER
120enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_PEER2PEER;
121#else
122enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_DEFAULT;
123#endif
124
125/*
126 * The default CLS is used if arch didn't set CLS explicitly and not
127 * all pci devices agree on the same value. Arch can override either
128 * the dfl or actual value as it sees fit. Don't forget this is
129 * measured in 32-bit words, not bytes.
130 */
131u8 pci_dfl_cache_line_size = L1_CACHE_BYTES >> 2;
132u8 pci_cache_line_size;
133
134/*
135 * If we set up a device for bus mastering, we need to check the latency
136 * timer as certain BIOSes forget to set it properly.
137 */
138unsigned int pcibios_max_latency = 255;
139
140/* If set, the PCIe ARI capability will not be used. */
141static bool pcie_ari_disabled;
142
143/* If set, the PCIe ATS capability will not be used. */
144static bool pcie_ats_disabled;
145
146/* If set, the PCI config space of each device is printed during boot. */
147bool pci_early_dump;
148
149bool pci_ats_disabled(void)
150{
151 return pcie_ats_disabled;
152}
153EXPORT_SYMBOL_GPL(pci_ats_disabled);
154
155/* Disable bridge_d3 for all PCIe ports */
156static bool pci_bridge_d3_disable;
157/* Force bridge_d3 for all PCIe ports */
158static bool pci_bridge_d3_force;
159
160static int __init pcie_port_pm_setup(char *str)
161{
162 if (!strcmp(str, "off"))
163 pci_bridge_d3_disable = true;
164 else if (!strcmp(str, "force"))
165 pci_bridge_d3_force = true;
166 return 1;
167}
168__setup("pcie_port_pm=", pcie_port_pm_setup);
169
170/* Time to wait after a reset for device to become responsive */
171#define PCIE_RESET_READY_POLL_MS 60000
172
173/**
174 * pci_bus_max_busnr - returns maximum PCI bus number of given bus' children
175 * @bus: pointer to PCI bus structure to search
176 *
177 * Given a PCI bus, returns the highest PCI bus number present in the set
178 * including the given PCI bus and its list of child PCI buses.
179 */
180unsigned char pci_bus_max_busnr(struct pci_bus *bus)
181{
182 struct pci_bus *tmp;
183 unsigned char max, n;
184
185 max = bus->busn_res.end;
186 list_for_each_entry(tmp, &bus->children, node) {
187 n = pci_bus_max_busnr(tmp);
188 if (n > max)
189 max = n;
190 }
191 return max;
192}
193EXPORT_SYMBOL_GPL(pci_bus_max_busnr);
194
195/**
196 * pci_status_get_and_clear_errors - return and clear error bits in PCI_STATUS
197 * @pdev: the PCI device
198 *
199 * Returns error bits set in PCI_STATUS and clears them.
200 */
201int pci_status_get_and_clear_errors(struct pci_dev *pdev)
202{
203 u16 status;
204 int ret;
205
206 ret = pci_read_config_word(pdev, PCI_STATUS, &status);
207 if (ret != PCIBIOS_SUCCESSFUL)
208 return -EIO;
209
210 status &= PCI_STATUS_ERROR_BITS;
211 if (status)
212 pci_write_config_word(pdev, PCI_STATUS, status);
213
214 return status;
215}
216EXPORT_SYMBOL_GPL(pci_status_get_and_clear_errors);
217
218#ifdef CONFIG_HAS_IOMEM
219static void __iomem *__pci_ioremap_resource(struct pci_dev *pdev, int bar,
220 bool write_combine)
221{
222 struct resource *res = &pdev->resource[bar];
223 resource_size_t start = res->start;
224 resource_size_t size = resource_size(res);
225
226 /*
227 * Make sure the BAR is actually a memory resource, not an IO resource
228 */
229 if (res->flags & IORESOURCE_UNSET || !(res->flags & IORESOURCE_MEM)) {
230 pci_err(pdev, "can't ioremap BAR %d: %pR\n", bar, res);
231 return NULL;
232 }
233
234 if (write_combine)
235 return ioremap_wc(start, size);
236
237 return ioremap(start, size);
238}
239
240void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar)
241{
242 return __pci_ioremap_resource(pdev, bar, false);
243}
244EXPORT_SYMBOL_GPL(pci_ioremap_bar);
245
246void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar)
247{
248 return __pci_ioremap_resource(pdev, bar, true);
249}
250EXPORT_SYMBOL_GPL(pci_ioremap_wc_bar);
251#endif
252
253/**
254 * pci_dev_str_match_path - test if a path string matches a device
255 * @dev: the PCI device to test
256 * @path: string to match the device against
257 * @endptr: pointer to the string after the match
258 *
259 * Test if a string (typically from a kernel parameter) formatted as a
260 * path of device/function addresses matches a PCI device. The string must
261 * be of the form:
262 *
263 * [<domain>:]<bus>:<device>.<func>[/<device>.<func>]*
264 *
265 * A path for a device can be obtained using 'lspci -t'. Using a path
266 * is more robust against bus renumbering than using only a single bus,
267 * device and function address.
268 *
269 * Returns 1 if the string matches the device, 0 if it does not and
270 * a negative error code if it fails to parse the string.
271 */
272static int pci_dev_str_match_path(struct pci_dev *dev, const char *path,
273 const char **endptr)
274{
275 int ret;
276 unsigned int seg, bus, slot, func;
277 char *wpath, *p;
278 char end;
279
280 *endptr = strchrnul(path, ';');
281
282 wpath = kmemdup_nul(path, *endptr - path, GFP_ATOMIC);
283 if (!wpath)
284 return -ENOMEM;
285
286 while (1) {
287 p = strrchr(wpath, '/');
288 if (!p)
289 break;
290 ret = sscanf(p, "/%x.%x%c", &slot, &func, &end);
291 if (ret != 2) {
292 ret = -EINVAL;
293 goto free_and_exit;
294 }
295
296 if (dev->devfn != PCI_DEVFN(slot, func)) {
297 ret = 0;
298 goto free_and_exit;
299 }
300
301 /*
302 * Note: we don't need to get a reference to the upstream
303 * bridge because we hold a reference to the top level
304 * device which should hold a reference to the bridge,
305 * and so on.
306 */
307 dev = pci_upstream_bridge(dev);
308 if (!dev) {
309 ret = 0;
310 goto free_and_exit;
311 }
312
313 *p = 0;
314 }
315
316 ret = sscanf(wpath, "%x:%x:%x.%x%c", &seg, &bus, &slot,
317 &func, &end);
318 if (ret != 4) {
319 seg = 0;
320 ret = sscanf(wpath, "%x:%x.%x%c", &bus, &slot, &func, &end);
321 if (ret != 3) {
322 ret = -EINVAL;
323 goto free_and_exit;
324 }
325 }
326
327 ret = (seg == pci_domain_nr(dev->bus) &&
328 bus == dev->bus->number &&
329 dev->devfn == PCI_DEVFN(slot, func));
330
331free_and_exit:
332 kfree(wpath);
333 return ret;
334}
335
336/**
337 * pci_dev_str_match - test if a string matches a device
338 * @dev: the PCI device to test
339 * @p: string to match the device against
340 * @endptr: pointer to the string after the match
341 *
342 * Test if a string (typically from a kernel parameter) matches a specified
343 * PCI device. The string may be of one of the following formats:
344 *
345 * [<domain>:]<bus>:<device>.<func>[/<device>.<func>]*
346 * pci:<vendor>:<device>[:<subvendor>:<subdevice>]
347 *
348 * The first format specifies a PCI bus/device/function address which
349 * may change if new hardware is inserted, if motherboard firmware changes,
350 * or due to changes caused in kernel parameters. If the domain is
351 * left unspecified, it is taken to be 0. In order to be robust against
352 * bus renumbering issues, a path of PCI device/function numbers may be used
353 * to address the specific device. The path for a device can be determined
354 * through the use of 'lspci -t'.
355 *
356 * The second format matches devices using IDs in the configuration
357 * space which may match multiple devices in the system. A value of 0
358 * for any field will match all devices. (Note: this differs from
359 * in-kernel code that uses PCI_ANY_ID which is ~0; this is for
360 * legacy reasons and convenience so users don't have to specify
361 * FFFFFFFFs on the command line.)
362 *
363 * Returns 1 if the string matches the device, 0 if it does not and
364 * a negative error code if the string cannot be parsed.
365 */
366static int pci_dev_str_match(struct pci_dev *dev, const char *p,
367 const char **endptr)
368{
369 int ret;
370 int count;
371 unsigned short vendor, device, subsystem_vendor, subsystem_device;
372
373 if (strncmp(p, "pci:", 4) == 0) {
374 /* PCI vendor/device (subvendor/subdevice) IDs are specified */
375 p += 4;
376 ret = sscanf(p, "%hx:%hx:%hx:%hx%n", &vendor, &device,
377 &subsystem_vendor, &subsystem_device, &count);
378 if (ret != 4) {
379 ret = sscanf(p, "%hx:%hx%n", &vendor, &device, &count);
380 if (ret != 2)
381 return -EINVAL;
382
383 subsystem_vendor = 0;
384 subsystem_device = 0;
385 }
386
387 p += count;
388
389 if ((!vendor || vendor == dev->vendor) &&
390 (!device || device == dev->device) &&
391 (!subsystem_vendor ||
392 subsystem_vendor == dev->subsystem_vendor) &&
393 (!subsystem_device ||
394 subsystem_device == dev->subsystem_device))
395 goto found;
396 } else {
397 /*
398 * PCI Bus, Device, Function IDs are specified
399 * (optionally, may include a path of devfns following it)
400 */
401 ret = pci_dev_str_match_path(dev, p, &p);
402 if (ret < 0)
403 return ret;
404 else if (ret)
405 goto found;
406 }
407
408 *endptr = p;
409 return 0;
410
411found:
412 *endptr = p;
413 return 1;
414}
415
416static u8 __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn,
417 u8 pos, int cap, int *ttl)
418{
419 u8 id;
420 u16 ent;
421
422 pci_bus_read_config_byte(bus, devfn, pos, &pos);
423
424 while ((*ttl)--) {
425 if (pos < 0x40)
426 break;
427 pos &= ~3;
428 pci_bus_read_config_word(bus, devfn, pos, &ent);
429
430 id = ent & 0xff;
431 if (id == 0xff)
432 break;
433 if (id == cap)
434 return pos;
435 pos = (ent >> 8);
436 }
437 return 0;
438}
439
440static u8 __pci_find_next_cap(struct pci_bus *bus, unsigned int devfn,
441 u8 pos, int cap)
442{
443 int ttl = PCI_FIND_CAP_TTL;
444
445 return __pci_find_next_cap_ttl(bus, devfn, pos, cap, &ttl);
446}
447
448u8 pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap)
449{
450 return __pci_find_next_cap(dev->bus, dev->devfn,
451 pos + PCI_CAP_LIST_NEXT, cap);
452}
453EXPORT_SYMBOL_GPL(pci_find_next_capability);
454
455static u8 __pci_bus_find_cap_start(struct pci_bus *bus,
456 unsigned int devfn, u8 hdr_type)
457{
458 u16 status;
459
460 pci_bus_read_config_word(bus, devfn, PCI_STATUS, &status);
461 if (!(status & PCI_STATUS_CAP_LIST))
462 return 0;
463
464 switch (hdr_type) {
465 case PCI_HEADER_TYPE_NORMAL:
466 case PCI_HEADER_TYPE_BRIDGE:
467 return PCI_CAPABILITY_LIST;
468 case PCI_HEADER_TYPE_CARDBUS:
469 return PCI_CB_CAPABILITY_LIST;
470 }
471
472 return 0;
473}
474
475/**
476 * pci_find_capability - query for devices' capabilities
477 * @dev: PCI device to query
478 * @cap: capability code
479 *
480 * Tell if a device supports a given PCI capability.
481 * Returns the address of the requested capability structure within the
482 * device's PCI configuration space or 0 in case the device does not
483 * support it. Possible values for @cap include:
484 *
485 * %PCI_CAP_ID_PM Power Management
486 * %PCI_CAP_ID_AGP Accelerated Graphics Port
487 * %PCI_CAP_ID_VPD Vital Product Data
488 * %PCI_CAP_ID_SLOTID Slot Identification
489 * %PCI_CAP_ID_MSI Message Signalled Interrupts
490 * %PCI_CAP_ID_CHSWP CompactPCI HotSwap
491 * %PCI_CAP_ID_PCIX PCI-X
492 * %PCI_CAP_ID_EXP PCI Express
493 */
494u8 pci_find_capability(struct pci_dev *dev, int cap)
495{
496 u8 pos;
497
498 pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);
499 if (pos)
500 pos = __pci_find_next_cap(dev->bus, dev->devfn, pos, cap);
501
502 return pos;
503}
504EXPORT_SYMBOL(pci_find_capability);
505
506/**
507 * pci_bus_find_capability - query for devices' capabilities
508 * @bus: the PCI bus to query
509 * @devfn: PCI device to query
510 * @cap: capability code
511 *
512 * Like pci_find_capability() but works for PCI devices that do not have a
513 * pci_dev structure set up yet.
514 *
515 * Returns the address of the requested capability structure within the
516 * device's PCI configuration space or 0 in case the device does not
517 * support it.
518 */
519u8 pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap)
520{
521 u8 hdr_type, pos;
522
523 pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &hdr_type);
524
525 pos = __pci_bus_find_cap_start(bus, devfn, hdr_type & 0x7f);
526 if (pos)
527 pos = __pci_find_next_cap(bus, devfn, pos, cap);
528
529 return pos;
530}
531EXPORT_SYMBOL(pci_bus_find_capability);
532
533/**
534 * pci_find_next_ext_capability - Find an extended capability
535 * @dev: PCI device to query
536 * @start: address at which to start looking (0 to start at beginning of list)
537 * @cap: capability code
538 *
539 * Returns the address of the next matching extended capability structure
540 * within the device's PCI configuration space or 0 if the device does
541 * not support it. Some capabilities can occur several times, e.g., the
542 * vendor-specific capability, and this provides a way to find them all.
543 */
544u16 pci_find_next_ext_capability(struct pci_dev *dev, u16 start, int cap)
545{
546 u32 header;
547 int ttl;
548 u16 pos = PCI_CFG_SPACE_SIZE;
549
550 /* minimum 8 bytes per capability */
551 ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8;
552
553 if (dev->cfg_size <= PCI_CFG_SPACE_SIZE)
554 return 0;
555
556 if (start)
557 pos = start;
558
559 if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
560 return 0;
561
562 /*
563 * If we have no capabilities, this is indicated by cap ID,
564 * cap version and next pointer all being 0.
565 */
566 if (header == 0)
567 return 0;
568
569 while (ttl-- > 0) {
570 if (PCI_EXT_CAP_ID(header) == cap && pos != start)
571 return pos;
572
573 pos = PCI_EXT_CAP_NEXT(header);
574 if (pos < PCI_CFG_SPACE_SIZE)
575 break;
576
577 if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
578 break;
579 }
580
581 return 0;
582}
583EXPORT_SYMBOL_GPL(pci_find_next_ext_capability);
584
585/**
586 * pci_find_ext_capability - Find an extended capability
587 * @dev: PCI device to query
588 * @cap: capability code
589 *
590 * Returns the address of the requested extended capability structure
591 * within the device's PCI configuration space or 0 if the device does
592 * not support it. Possible values for @cap include:
593 *
594 * %PCI_EXT_CAP_ID_ERR Advanced Error Reporting
595 * %PCI_EXT_CAP_ID_VC Virtual Channel
596 * %PCI_EXT_CAP_ID_DSN Device Serial Number
597 * %PCI_EXT_CAP_ID_PWR Power Budgeting
598 */
599u16 pci_find_ext_capability(struct pci_dev *dev, int cap)
600{
601 return pci_find_next_ext_capability(dev, 0, cap);
602}
603EXPORT_SYMBOL_GPL(pci_find_ext_capability);
604
605/**
606 * pci_get_dsn - Read and return the 8-byte Device Serial Number
607 * @dev: PCI device to query
608 *
609 * Looks up the PCI_EXT_CAP_ID_DSN and reads the 8 bytes of the Device Serial
610 * Number.
611 *
612 * Returns the DSN, or zero if the capability does not exist.
613 */
614u64 pci_get_dsn(struct pci_dev *dev)
615{
616 u32 dword;
617 u64 dsn;
618 int pos;
619
620 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DSN);
621 if (!pos)
622 return 0;
623
624 /*
625 * The Device Serial Number is two dwords offset 4 bytes from the
626 * capability position. The specification says that the first dword is
627 * the lower half, and the second dword is the upper half.
628 */
629 pos += 4;
630 pci_read_config_dword(dev, pos, &dword);
631 dsn = (u64)dword;
632 pci_read_config_dword(dev, pos + 4, &dword);
633 dsn |= ((u64)dword) << 32;
634
635 return dsn;
636}
637EXPORT_SYMBOL_GPL(pci_get_dsn);
638
639static u8 __pci_find_next_ht_cap(struct pci_dev *dev, u8 pos, int ht_cap)
640{
641 int rc, ttl = PCI_FIND_CAP_TTL;
642 u8 cap, mask;
643
644 if (ht_cap == HT_CAPTYPE_SLAVE || ht_cap == HT_CAPTYPE_HOST)
645 mask = HT_3BIT_CAP_MASK;
646 else
647 mask = HT_5BIT_CAP_MASK;
648
649 pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn, pos,
650 PCI_CAP_ID_HT, &ttl);
651 while (pos) {
652 rc = pci_read_config_byte(dev, pos + 3, &cap);
653 if (rc != PCIBIOS_SUCCESSFUL)
654 return 0;
655
656 if ((cap & mask) == ht_cap)
657 return pos;
658
659 pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn,
660 pos + PCI_CAP_LIST_NEXT,
661 PCI_CAP_ID_HT, &ttl);
662 }
663
664 return 0;
665}
666
667/**
668 * pci_find_next_ht_capability - query a device's HyperTransport capabilities
669 * @dev: PCI device to query
670 * @pos: Position from which to continue searching
671 * @ht_cap: HyperTransport capability code
672 *
673 * To be used in conjunction with pci_find_ht_capability() to search for
674 * all capabilities matching @ht_cap. @pos should always be a value returned
675 * from pci_find_ht_capability().
676 *
677 * NB. To be 100% safe against broken PCI devices, the caller should take
678 * steps to avoid an infinite loop.
679 */
680u8 pci_find_next_ht_capability(struct pci_dev *dev, u8 pos, int ht_cap)
681{
682 return __pci_find_next_ht_cap(dev, pos + PCI_CAP_LIST_NEXT, ht_cap);
683}
684EXPORT_SYMBOL_GPL(pci_find_next_ht_capability);
685
686/**
687 * pci_find_ht_capability - query a device's HyperTransport capabilities
688 * @dev: PCI device to query
689 * @ht_cap: HyperTransport capability code
690 *
691 * Tell if a device supports a given HyperTransport capability.
692 * Returns an address within the device's PCI configuration space
693 * or 0 in case the device does not support the request capability.
694 * The address points to the PCI capability, of type PCI_CAP_ID_HT,
695 * which has a HyperTransport capability matching @ht_cap.
696 */
697u8 pci_find_ht_capability(struct pci_dev *dev, int ht_cap)
698{
699 u8 pos;
700
701 pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);
702 if (pos)
703 pos = __pci_find_next_ht_cap(dev, pos, ht_cap);
704
705 return pos;
706}
707EXPORT_SYMBOL_GPL(pci_find_ht_capability);
708
709/**
710 * pci_find_vsec_capability - Find a vendor-specific extended capability
711 * @dev: PCI device to query
712 * @vendor: Vendor ID for which capability is defined
713 * @cap: Vendor-specific capability ID
714 *
715 * If @dev has Vendor ID @vendor, search for a VSEC capability with
716 * VSEC ID @cap. If found, return the capability offset in
717 * config space; otherwise return 0.
718 */
719u16 pci_find_vsec_capability(struct pci_dev *dev, u16 vendor, int cap)
720{
721 u16 vsec = 0;
722 u32 header;
723
724 if (vendor != dev->vendor)
725 return 0;
726
727 while ((vsec = pci_find_next_ext_capability(dev, vsec,
728 PCI_EXT_CAP_ID_VNDR))) {
729 if (pci_read_config_dword(dev, vsec + PCI_VNDR_HEADER,
730 &header) == PCIBIOS_SUCCESSFUL &&
731 PCI_VNDR_HEADER_ID(header) == cap)
732 return vsec;
733 }
734
735 return 0;
736}
737EXPORT_SYMBOL_GPL(pci_find_vsec_capability);
738
739/**
740 * pci_find_dvsec_capability - Find DVSEC for vendor
741 * @dev: PCI device to query
742 * @vendor: Vendor ID to match for the DVSEC
743 * @dvsec: Designated Vendor-specific capability ID
744 *
745 * If DVSEC has Vendor ID @vendor and DVSEC ID @dvsec return the capability
746 * offset in config space; otherwise return 0.
747 */
748u16 pci_find_dvsec_capability(struct pci_dev *dev, u16 vendor, u16 dvsec)
749{
750 int pos;
751
752 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DVSEC);
753 if (!pos)
754 return 0;
755
756 while (pos) {
757 u16 v, id;
758
759 pci_read_config_word(dev, pos + PCI_DVSEC_HEADER1, &v);
760 pci_read_config_word(dev, pos + PCI_DVSEC_HEADER2, &id);
761 if (vendor == v && dvsec == id)
762 return pos;
763
764 pos = pci_find_next_ext_capability(dev, pos, PCI_EXT_CAP_ID_DVSEC);
765 }
766
767 return 0;
768}
769EXPORT_SYMBOL_GPL(pci_find_dvsec_capability);
770
771/**
772 * pci_find_parent_resource - return resource region of parent bus of given
773 * region
774 * @dev: PCI device structure contains resources to be searched
775 * @res: child resource record for which parent is sought
776 *
777 * For given resource region of given device, return the resource region of
778 * parent bus the given region is contained in.
779 */
780struct resource *pci_find_parent_resource(const struct pci_dev *dev,
781 struct resource *res)
782{
783 const struct pci_bus *bus = dev->bus;
784 struct resource *r;
785 int i;
786
787 pci_bus_for_each_resource(bus, r, i) {
788 if (!r)
789 continue;
790 if (resource_contains(r, res)) {
791
792 /*
793 * If the window is prefetchable but the BAR is
794 * not, the allocator made a mistake.
795 */
796 if (r->flags & IORESOURCE_PREFETCH &&
797 !(res->flags & IORESOURCE_PREFETCH))
798 return NULL;
799
800 /*
801 * If we're below a transparent bridge, there may
802 * be both a positively-decoded aperture and a
803 * subtractively-decoded region that contain the BAR.
804 * We want the positively-decoded one, so this depends
805 * on pci_bus_for_each_resource() giving us those
806 * first.
807 */
808 return r;
809 }
810 }
811 return NULL;
812}
813EXPORT_SYMBOL(pci_find_parent_resource);
814
815/**
816 * pci_find_resource - Return matching PCI device resource
817 * @dev: PCI device to query
818 * @res: Resource to look for
819 *
820 * Goes over standard PCI resources (BARs) and checks if the given resource
821 * is partially or fully contained in any of them. In that case the
822 * matching resource is returned, %NULL otherwise.
823 */
824struct resource *pci_find_resource(struct pci_dev *dev, struct resource *res)
825{
826 int i;
827
828 for (i = 0; i < PCI_STD_NUM_BARS; i++) {
829 struct resource *r = &dev->resource[i];
830
831 if (r->start && resource_contains(r, res))
832 return r;
833 }
834
835 return NULL;
836}
837EXPORT_SYMBOL(pci_find_resource);
838
839/**
840 * pci_wait_for_pending - wait for @mask bit(s) to clear in status word @pos
841 * @dev: the PCI device to operate on
842 * @pos: config space offset of status word
843 * @mask: mask of bit(s) to care about in status word
844 *
845 * Return 1 when mask bit(s) in status word clear, 0 otherwise.
846 */
847int pci_wait_for_pending(struct pci_dev *dev, int pos, u16 mask)
848{
849 int i;
850
851 /* Wait for Transaction Pending bit clean */
852 for (i = 0; i < 4; i++) {
853 u16 status;
854 if (i)
855 msleep((1 << (i - 1)) * 100);
856
857 pci_read_config_word(dev, pos, &status);
858 if (!(status & mask))
859 return 1;
860 }
861
862 return 0;
863}
864
865static int pci_acs_enable;
866
867/**
868 * pci_request_acs - ask for ACS to be enabled if supported
869 */
870void pci_request_acs(void)
871{
872 pci_acs_enable = 1;
873}
874
875static const char *disable_acs_redir_param;
876
877/**
878 * pci_disable_acs_redir - disable ACS redirect capabilities
879 * @dev: the PCI device
880 *
881 * For only devices specified in the disable_acs_redir parameter.
882 */
883static void pci_disable_acs_redir(struct pci_dev *dev)
884{
885 int ret = 0;
886 const char *p;
887 int pos;
888 u16 ctrl;
889
890 if (!disable_acs_redir_param)
891 return;
892
893 p = disable_acs_redir_param;
894 while (*p) {
895 ret = pci_dev_str_match(dev, p, &p);
896 if (ret < 0) {
897 pr_info_once("PCI: Can't parse disable_acs_redir parameter: %s\n",
898 disable_acs_redir_param);
899
900 break;
901 } else if (ret == 1) {
902 /* Found a match */
903 break;
904 }
905
906 if (*p != ';' && *p != ',') {
907 /* End of param or invalid format */
908 break;
909 }
910 p++;
911 }
912
913 if (ret != 1)
914 return;
915
916 if (!pci_dev_specific_disable_acs_redir(dev))
917 return;
918
919 pos = dev->acs_cap;
920 if (!pos) {
921 pci_warn(dev, "cannot disable ACS redirect for this hardware as it does not have ACS capabilities\n");
922 return;
923 }
924
925 pci_read_config_word(dev, pos + PCI_ACS_CTRL, &ctrl);
926
927 /* P2P Request & Completion Redirect */
928 ctrl &= ~(PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_EC);
929
930 pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl);
931
932 pci_info(dev, "disabled ACS redirect\n");
933}
934
935/**
936 * pci_std_enable_acs - enable ACS on devices using standard ACS capabilities
937 * @dev: the PCI device
938 */
939static void pci_std_enable_acs(struct pci_dev *dev)
940{
941 int pos;
942 u16 cap;
943 u16 ctrl;
944
945 pos = dev->acs_cap;
946 if (!pos)
947 return;
948
949 pci_read_config_word(dev, pos + PCI_ACS_CAP, &cap);
950 pci_read_config_word(dev, pos + PCI_ACS_CTRL, &ctrl);
951
952 /* Source Validation */
953 ctrl |= (cap & PCI_ACS_SV);
954
955 /* P2P Request Redirect */
956 ctrl |= (cap & PCI_ACS_RR);
957
958 /* P2P Completion Redirect */
959 ctrl |= (cap & PCI_ACS_CR);
960
961 /* Upstream Forwarding */
962 ctrl |= (cap & PCI_ACS_UF);
963
964 /* Enable Translation Blocking for external devices and noats */
965 if (pci_ats_disabled() || dev->external_facing || dev->untrusted)
966 ctrl |= (cap & PCI_ACS_TB);
967
968 pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl);
969}
970
971/**
972 * pci_enable_acs - enable ACS if hardware support it
973 * @dev: the PCI device
974 */
975static void pci_enable_acs(struct pci_dev *dev)
976{
977 if (!pci_acs_enable)
978 goto disable_acs_redir;
979
980 if (!pci_dev_specific_enable_acs(dev))
981 goto disable_acs_redir;
982
983 pci_std_enable_acs(dev);
984
985disable_acs_redir:
986 /*
987 * Note: pci_disable_acs_redir() must be called even if ACS was not
988 * enabled by the kernel because it may have been enabled by
989 * platform firmware. So if we are told to disable it, we should
990 * always disable it after setting the kernel's default
991 * preferences.
992 */
993 pci_disable_acs_redir(dev);
994}
995
996/**
997 * pci_restore_bars - restore a device's BAR values (e.g. after wake-up)
998 * @dev: PCI device to have its BARs restored
999 *
1000 * Restore the BAR values for a given device, so as to make it
1001 * accessible by its driver.
1002 */
1003static void pci_restore_bars(struct pci_dev *dev)
1004{
1005 int i;
1006
1007 for (i = 0; i < PCI_BRIDGE_RESOURCES; i++)
1008 pci_update_resource(dev, i);
1009}
1010
1011static inline bool platform_pci_power_manageable(struct pci_dev *dev)
1012{
1013 if (pci_use_mid_pm())
1014 return true;
1015
1016 return acpi_pci_power_manageable(dev);
1017}
1018
1019static inline int platform_pci_set_power_state(struct pci_dev *dev,
1020 pci_power_t t)
1021{
1022 if (pci_use_mid_pm())
1023 return mid_pci_set_power_state(dev, t);
1024
1025 return acpi_pci_set_power_state(dev, t);
1026}
1027
1028static inline pci_power_t platform_pci_get_power_state(struct pci_dev *dev)
1029{
1030 if (pci_use_mid_pm())
1031 return mid_pci_get_power_state(dev);
1032
1033 return acpi_pci_get_power_state(dev);
1034}
1035
1036static inline void platform_pci_refresh_power_state(struct pci_dev *dev)
1037{
1038 if (!pci_use_mid_pm())
1039 acpi_pci_refresh_power_state(dev);
1040}
1041
1042static inline pci_power_t platform_pci_choose_state(struct pci_dev *dev)
1043{
1044 if (pci_use_mid_pm())
1045 return PCI_POWER_ERROR;
1046
1047 return acpi_pci_choose_state(dev);
1048}
1049
1050static inline int platform_pci_set_wakeup(struct pci_dev *dev, bool enable)
1051{
1052 if (pci_use_mid_pm())
1053 return PCI_POWER_ERROR;
1054
1055 return acpi_pci_wakeup(dev, enable);
1056}
1057
1058static inline bool platform_pci_need_resume(struct pci_dev *dev)
1059{
1060 if (pci_use_mid_pm())
1061 return false;
1062
1063 return acpi_pci_need_resume(dev);
1064}
1065
1066static inline bool platform_pci_bridge_d3(struct pci_dev *dev)
1067{
1068 if (pci_use_mid_pm())
1069 return false;
1070
1071 return acpi_pci_bridge_d3(dev);
1072}
1073
1074/**
1075 * pci_update_current_state - Read power state of given device and cache it
1076 * @dev: PCI device to handle.
1077 * @state: State to cache in case the device doesn't have the PM capability
1078 *
1079 * The power state is read from the PMCSR register, which however is
1080 * inaccessible in D3cold. The platform firmware is therefore queried first
1081 * to detect accessibility of the register. In case the platform firmware
1082 * reports an incorrect state or the device isn't power manageable by the
1083 * platform at all, we try to detect D3cold by testing accessibility of the
1084 * vendor ID in config space.
1085 */
1086void pci_update_current_state(struct pci_dev *dev, pci_power_t state)
1087{
1088 if (platform_pci_get_power_state(dev) == PCI_D3cold) {
1089 dev->current_state = PCI_D3cold;
1090 } else if (dev->pm_cap) {
1091 u16 pmcsr;
1092
1093 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
1094 if (PCI_POSSIBLE_ERROR(pmcsr)) {
1095 dev->current_state = PCI_D3cold;
1096 return;
1097 }
1098 dev->current_state = pmcsr & PCI_PM_CTRL_STATE_MASK;
1099 } else {
1100 dev->current_state = state;
1101 }
1102}
1103
1104/**
1105 * pci_refresh_power_state - Refresh the given device's power state data
1106 * @dev: Target PCI device.
1107 *
1108 * Ask the platform to refresh the devices power state information and invoke
1109 * pci_update_current_state() to update its current PCI power state.
1110 */
1111void pci_refresh_power_state(struct pci_dev *dev)
1112{
1113 platform_pci_refresh_power_state(dev);
1114 pci_update_current_state(dev, dev->current_state);
1115}
1116
1117/**
1118 * pci_platform_power_transition - Use platform to change device power state
1119 * @dev: PCI device to handle.
1120 * @state: State to put the device into.
1121 */
1122int pci_platform_power_transition(struct pci_dev *dev, pci_power_t state)
1123{
1124 int error;
1125
1126 error = platform_pci_set_power_state(dev, state);
1127 if (!error)
1128 pci_update_current_state(dev, state);
1129 else if (!dev->pm_cap) /* Fall back to PCI_D0 */
1130 dev->current_state = PCI_D0;
1131
1132 return error;
1133}
1134EXPORT_SYMBOL_GPL(pci_platform_power_transition);
1135
1136static int pci_resume_one(struct pci_dev *pci_dev, void *ign)
1137{
1138 pm_request_resume(&pci_dev->dev);
1139 return 0;
1140}
1141
1142/**
1143 * pci_resume_bus - Walk given bus and runtime resume devices on it
1144 * @bus: Top bus of the subtree to walk.
1145 */
1146void pci_resume_bus(struct pci_bus *bus)
1147{
1148 if (bus)
1149 pci_walk_bus(bus, pci_resume_one, NULL);
1150}
1151
1152static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout)
1153{
1154 int delay = 1;
1155 u32 id;
1156
1157 /*
1158 * After reset, the device should not silently discard config
1159 * requests, but it may still indicate that it needs more time by
1160 * responding to them with CRS completions. The Root Port will
1161 * generally synthesize ~0 (PCI_ERROR_RESPONSE) data to complete
1162 * the read (except when CRS SV is enabled and the read was for the
1163 * Vendor ID; in that case it synthesizes 0x0001 data).
1164 *
1165 * Wait for the device to return a non-CRS completion. Read the
1166 * Command register instead of Vendor ID so we don't have to
1167 * contend with the CRS SV value.
1168 */
1169 pci_read_config_dword(dev, PCI_COMMAND, &id);
1170 while (PCI_POSSIBLE_ERROR(id)) {
1171 if (delay > timeout) {
1172 pci_warn(dev, "not ready %dms after %s; giving up\n",
1173 delay - 1, reset_type);
1174 return -ENOTTY;
1175 }
1176
1177 if (delay > 1000)
1178 pci_info(dev, "not ready %dms after %s; waiting\n",
1179 delay - 1, reset_type);
1180
1181 msleep(delay);
1182 delay *= 2;
1183 pci_read_config_dword(dev, PCI_COMMAND, &id);
1184 }
1185
1186 if (delay > 1000)
1187 pci_info(dev, "ready %dms after %s\n", delay - 1,
1188 reset_type);
1189
1190 return 0;
1191}
1192
1193/**
1194 * pci_power_up - Put the given device into D0
1195 * @dev: PCI device to power up
1196 *
1197 * On success, return 0 or 1, depending on whether or not it is necessary to
1198 * restore the device's BARs subsequently (1 is returned in that case).
1199 */
1200int pci_power_up(struct pci_dev *dev)
1201{
1202 bool need_restore;
1203 pci_power_t state;
1204 u16 pmcsr;
1205
1206 platform_pci_set_power_state(dev, PCI_D0);
1207
1208 if (!dev->pm_cap) {
1209 state = platform_pci_get_power_state(dev);
1210 if (state == PCI_UNKNOWN)
1211 dev->current_state = PCI_D0;
1212 else
1213 dev->current_state = state;
1214
1215 if (state == PCI_D0)
1216 return 0;
1217
1218 return -EIO;
1219 }
1220
1221 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
1222 if (PCI_POSSIBLE_ERROR(pmcsr)) {
1223 pci_err(dev, "Unable to change power state from %s to D0, device inaccessible\n",
1224 pci_power_name(dev->current_state));
1225 dev->current_state = PCI_D3cold;
1226 return -EIO;
1227 }
1228
1229 state = pmcsr & PCI_PM_CTRL_STATE_MASK;
1230
1231 need_restore = (state == PCI_D3hot || dev->current_state >= PCI_D3hot) &&
1232 !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET);
1233
1234 if (state == PCI_D0)
1235 goto end;
1236
1237 /*
1238 * Force the entire word to 0. This doesn't affect PME_Status, disables
1239 * PME_En, and sets PowerState to 0.
1240 */
1241 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, 0);
1242
1243 /* Mandatory transition delays; see PCI PM 1.2. */
1244 if (state == PCI_D3hot)
1245 pci_dev_d3_sleep(dev);
1246 else if (state == PCI_D2)
1247 udelay(PCI_PM_D2_DELAY);
1248
1249end:
1250 dev->current_state = PCI_D0;
1251 if (need_restore)
1252 return 1;
1253
1254 return 0;
1255}
1256
1257/**
1258 * pci_set_full_power_state - Put a PCI device into D0 and update its state
1259 * @dev: PCI device to power up
1260 *
1261 * Call pci_power_up() to put @dev into D0, read from its PCI_PM_CTRL register
1262 * to confirm the state change, restore its BARs if they might be lost and
1263 * reconfigure ASPM in acordance with the new power state.
1264 *
1265 * If pci_restore_state() is going to be called right after a power state change
1266 * to D0, it is more efficient to use pci_power_up() directly instead of this
1267 * function.
1268 */
1269static int pci_set_full_power_state(struct pci_dev *dev)
1270{
1271 u16 pmcsr;
1272 int ret;
1273
1274 ret = pci_power_up(dev);
1275 if (ret < 0)
1276 return ret;
1277
1278 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
1279 dev->current_state = pmcsr & PCI_PM_CTRL_STATE_MASK;
1280 if (dev->current_state != PCI_D0) {
1281 pci_info_ratelimited(dev, "Refused to change power state from %s to D0\n",
1282 pci_power_name(dev->current_state));
1283 } else if (ret > 0) {
1284 /*
1285 * According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT
1286 * INTERFACE SPECIFICATION, REV. 1.2", a device transitioning
1287 * from D3hot to D0 _may_ perform an internal reset, thereby
1288 * going to "D0 Uninitialized" rather than "D0 Initialized".
1289 * For example, at least some versions of the 3c905B and the
1290 * 3c556B exhibit this behaviour.
1291 *
1292 * At least some laptop BIOSen (e.g. the Thinkpad T21) leave
1293 * devices in a D3hot state at boot. Consequently, we need to
1294 * restore at least the BARs so that the device will be
1295 * accessible to its driver.
1296 */
1297 pci_restore_bars(dev);
1298 }
1299
1300 return 0;
1301}
1302
1303/**
1304 * __pci_dev_set_current_state - Set current state of a PCI device
1305 * @dev: Device to handle
1306 * @data: pointer to state to be set
1307 */
1308static int __pci_dev_set_current_state(struct pci_dev *dev, void *data)
1309{
1310 pci_power_t state = *(pci_power_t *)data;
1311
1312 dev->current_state = state;
1313 return 0;
1314}
1315
1316/**
1317 * pci_bus_set_current_state - Walk given bus and set current state of devices
1318 * @bus: Top bus of the subtree to walk.
1319 * @state: state to be set
1320 */
1321void pci_bus_set_current_state(struct pci_bus *bus, pci_power_t state)
1322{
1323 if (bus)
1324 pci_walk_bus(bus, __pci_dev_set_current_state, &state);
1325}
1326
1327/**
1328 * pci_set_low_power_state - Put a PCI device into a low-power state.
1329 * @dev: PCI device to handle.
1330 * @state: PCI power state (D1, D2, D3hot) to put the device into.
1331 *
1332 * Use the device's PCI_PM_CTRL register to put it into a low-power state.
1333 *
1334 * RETURN VALUE:
1335 * -EINVAL if the requested state is invalid.
1336 * -EIO if device does not support PCI PM or its PM capabilities register has a
1337 * wrong version, or device doesn't support the requested state.
1338 * 0 if device already is in the requested state.
1339 * 0 if device's power state has been successfully changed.
1340 */
1341static int pci_set_low_power_state(struct pci_dev *dev, pci_power_t state)
1342{
1343 u16 pmcsr;
1344
1345 if (!dev->pm_cap)
1346 return -EIO;
1347
1348 /*
1349 * Validate transition: We can enter D0 from any state, but if
1350 * we're already in a low-power state, we can only go deeper. E.g.,
1351 * we can go from D1 to D3, but we can't go directly from D3 to D1;
1352 * we'd have to go from D3 to D0, then to D1.
1353 */
1354 if (dev->current_state <= PCI_D3cold && dev->current_state > state) {
1355 pci_dbg(dev, "Invalid power transition (from %s to %s)\n",
1356 pci_power_name(dev->current_state),
1357 pci_power_name(state));
1358 return -EINVAL;
1359 }
1360
1361 /* Check if this device supports the desired state */
1362 if ((state == PCI_D1 && !dev->d1_support)
1363 || (state == PCI_D2 && !dev->d2_support))
1364 return -EIO;
1365
1366 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
1367 if (PCI_POSSIBLE_ERROR(pmcsr)) {
1368 pci_err(dev, "Unable to change power state from %s to %s, device inaccessible\n",
1369 pci_power_name(dev->current_state),
1370 pci_power_name(state));
1371 dev->current_state = PCI_D3cold;
1372 return -EIO;
1373 }
1374
1375 pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
1376 pmcsr |= state;
1377
1378 /* Enter specified state */
1379 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
1380
1381 /* Mandatory power management transition delays; see PCI PM 1.2. */
1382 if (state == PCI_D3hot)
1383 pci_dev_d3_sleep(dev);
1384 else if (state == PCI_D2)
1385 udelay(PCI_PM_D2_DELAY);
1386
1387 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
1388 dev->current_state = pmcsr & PCI_PM_CTRL_STATE_MASK;
1389 if (dev->current_state != state)
1390 pci_info_ratelimited(dev, "Refused to change power state from %s to %s\n",
1391 pci_power_name(dev->current_state),
1392 pci_power_name(state));
1393
1394 return 0;
1395}
1396
1397/**
1398 * pci_set_power_state - Set the power state of a PCI device
1399 * @dev: PCI device to handle.
1400 * @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
1401 *
1402 * Transition a device to a new power state, using the platform firmware and/or
1403 * the device's PCI PM registers.
1404 *
1405 * RETURN VALUE:
1406 * -EINVAL if the requested state is invalid.
1407 * -EIO if device does not support PCI PM or its PM capabilities register has a
1408 * wrong version, or device doesn't support the requested state.
1409 * 0 if the transition is to D1 or D2 but D1 and D2 are not supported.
1410 * 0 if device already is in the requested state.
1411 * 0 if the transition is to D3 but D3 is not supported.
1412 * 0 if device's power state has been successfully changed.
1413 */
1414int pci_set_power_state(struct pci_dev *dev, pci_power_t state)
1415{
1416 int error;
1417
1418 /* Bound the state we're entering */
1419 if (state > PCI_D3cold)
1420 state = PCI_D3cold;
1421 else if (state < PCI_D0)
1422 state = PCI_D0;
1423 else if ((state == PCI_D1 || state == PCI_D2) && pci_no_d1d2(dev))
1424
1425 /*
1426 * If the device or the parent bridge do not support PCI
1427 * PM, ignore the request if we're doing anything other
1428 * than putting it into D0 (which would only happen on
1429 * boot).
1430 */
1431 return 0;
1432
1433 /* Check if we're already there */
1434 if (dev->current_state == state)
1435 return 0;
1436
1437 if (state == PCI_D0)
1438 return pci_set_full_power_state(dev);
1439
1440 /*
1441 * This device is quirked not to be put into D3, so don't put it in
1442 * D3
1443 */
1444 if (state >= PCI_D3hot && (dev->dev_flags & PCI_DEV_FLAGS_NO_D3))
1445 return 0;
1446
1447 if (state == PCI_D3cold) {
1448 /*
1449 * To put the device in D3cold, put it into D3hot in the native
1450 * way, then put it into D3cold using platform ops.
1451 */
1452 error = pci_set_low_power_state(dev, PCI_D3hot);
1453
1454 if (pci_platform_power_transition(dev, PCI_D3cold))
1455 return error;
1456
1457 /* Powering off a bridge may power off the whole hierarchy */
1458 if (dev->current_state == PCI_D3cold)
1459 pci_bus_set_current_state(dev->subordinate, PCI_D3cold);
1460 } else {
1461 error = pci_set_low_power_state(dev, state);
1462
1463 if (pci_platform_power_transition(dev, state))
1464 return error;
1465 }
1466
1467 return 0;
1468}
1469EXPORT_SYMBOL(pci_set_power_state);
1470
1471#define PCI_EXP_SAVE_REGS 7
1472
1473static struct pci_cap_saved_state *_pci_find_saved_cap(struct pci_dev *pci_dev,
1474 u16 cap, bool extended)
1475{
1476 struct pci_cap_saved_state *tmp;
1477
1478 hlist_for_each_entry(tmp, &pci_dev->saved_cap_space, next) {
1479 if (tmp->cap.cap_extended == extended && tmp->cap.cap_nr == cap)
1480 return tmp;
1481 }
1482 return NULL;
1483}
1484
1485struct pci_cap_saved_state *pci_find_saved_cap(struct pci_dev *dev, char cap)
1486{
1487 return _pci_find_saved_cap(dev, cap, false);
1488}
1489
1490struct pci_cap_saved_state *pci_find_saved_ext_cap(struct pci_dev *dev, u16 cap)
1491{
1492 return _pci_find_saved_cap(dev, cap, true);
1493}
1494
1495static int pci_save_pcie_state(struct pci_dev *dev)
1496{
1497 int i = 0;
1498 struct pci_cap_saved_state *save_state;
1499 u16 *cap;
1500
1501 if (!pci_is_pcie(dev))
1502 return 0;
1503
1504 save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
1505 if (!save_state) {
1506 pci_err(dev, "buffer not found in %s\n", __func__);
1507 return -ENOMEM;
1508 }
1509
1510 cap = (u16 *)&save_state->cap.data[0];
1511 pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &cap[i++]);
1512 pcie_capability_read_word(dev, PCI_EXP_LNKCTL, &cap[i++]);
1513 pcie_capability_read_word(dev, PCI_EXP_SLTCTL, &cap[i++]);
1514 pcie_capability_read_word(dev, PCI_EXP_RTCTL, &cap[i++]);
1515 pcie_capability_read_word(dev, PCI_EXP_DEVCTL2, &cap[i++]);
1516 pcie_capability_read_word(dev, PCI_EXP_LNKCTL2, &cap[i++]);
1517 pcie_capability_read_word(dev, PCI_EXP_SLTCTL2, &cap[i++]);
1518
1519 return 0;
1520}
1521
1522void pci_bridge_reconfigure_ltr(struct pci_dev *dev)
1523{
1524#ifdef CONFIG_PCIEASPM
1525 struct pci_dev *bridge;
1526 u32 ctl;
1527
1528 bridge = pci_upstream_bridge(dev);
1529 if (bridge && bridge->ltr_path) {
1530 pcie_capability_read_dword(bridge, PCI_EXP_DEVCTL2, &ctl);
1531 if (!(ctl & PCI_EXP_DEVCTL2_LTR_EN)) {
1532 pci_dbg(bridge, "re-enabling LTR\n");
1533 pcie_capability_set_word(bridge, PCI_EXP_DEVCTL2,
1534 PCI_EXP_DEVCTL2_LTR_EN);
1535 }
1536 }
1537#endif
1538}
1539
1540static void pci_restore_pcie_state(struct pci_dev *dev)
1541{
1542 int i = 0;
1543 struct pci_cap_saved_state *save_state;
1544 u16 *cap;
1545
1546 save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
1547 if (!save_state)
1548 return;
1549
1550 /*
1551 * Downstream ports reset the LTR enable bit when link goes down.
1552 * Check and re-configure the bit here before restoring device.
1553 * PCIe r5.0, sec 7.5.3.16.
1554 */
1555 pci_bridge_reconfigure_ltr(dev);
1556
1557 cap = (u16 *)&save_state->cap.data[0];
1558 pcie_capability_write_word(dev, PCI_EXP_DEVCTL, cap[i++]);
1559 pcie_capability_write_word(dev, PCI_EXP_LNKCTL, cap[i++]);
1560 pcie_capability_write_word(dev, PCI_EXP_SLTCTL, cap[i++]);
1561 pcie_capability_write_word(dev, PCI_EXP_RTCTL, cap[i++]);
1562 pcie_capability_write_word(dev, PCI_EXP_DEVCTL2, cap[i++]);
1563 pcie_capability_write_word(dev, PCI_EXP_LNKCTL2, cap[i++]);
1564 pcie_capability_write_word(dev, PCI_EXP_SLTCTL2, cap[i++]);
1565}
1566
1567static int pci_save_pcix_state(struct pci_dev *dev)
1568{
1569 int pos;
1570 struct pci_cap_saved_state *save_state;
1571
1572 pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
1573 if (!pos)
1574 return 0;
1575
1576 save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX);
1577 if (!save_state) {
1578 pci_err(dev, "buffer not found in %s\n", __func__);
1579 return -ENOMEM;
1580 }
1581
1582 pci_read_config_word(dev, pos + PCI_X_CMD,
1583 (u16 *)save_state->cap.data);
1584
1585 return 0;
1586}
1587
1588static void pci_restore_pcix_state(struct pci_dev *dev)
1589{
1590 int i = 0, pos;
1591 struct pci_cap_saved_state *save_state;
1592 u16 *cap;
1593
1594 save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX);
1595 pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
1596 if (!save_state || !pos)
1597 return;
1598 cap = (u16 *)&save_state->cap.data[0];
1599
1600 pci_write_config_word(dev, pos + PCI_X_CMD, cap[i++]);
1601}
1602
1603static void pci_save_ltr_state(struct pci_dev *dev)
1604{
1605 int ltr;
1606 struct pci_cap_saved_state *save_state;
1607 u32 *cap;
1608
1609 if (!pci_is_pcie(dev))
1610 return;
1611
1612 ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR);
1613 if (!ltr)
1614 return;
1615
1616 save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR);
1617 if (!save_state) {
1618 pci_err(dev, "no suspend buffer for LTR; ASPM issues possible after resume\n");
1619 return;
1620 }
1621
1622 /* Some broken devices only support dword access to LTR */
1623 cap = &save_state->cap.data[0];
1624 pci_read_config_dword(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, cap);
1625}
1626
1627static void pci_restore_ltr_state(struct pci_dev *dev)
1628{
1629 struct pci_cap_saved_state *save_state;
1630 int ltr;
1631 u32 *cap;
1632
1633 save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR);
1634 ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR);
1635 if (!save_state || !ltr)
1636 return;
1637
1638 /* Some broken devices only support dword access to LTR */
1639 cap = &save_state->cap.data[0];
1640 pci_write_config_dword(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, *cap);
1641}
1642
1643/**
1644 * pci_save_state - save the PCI configuration space of a device before
1645 * suspending
1646 * @dev: PCI device that we're dealing with
1647 */
1648int pci_save_state(struct pci_dev *dev)
1649{
1650 int i;
1651 /* XXX: 100% dword access ok here? */
1652 for (i = 0; i < 16; i++) {
1653 pci_read_config_dword(dev, i * 4, &dev->saved_config_space[i]);
1654 pci_dbg(dev, "saving config space at offset %#x (reading %#x)\n",
1655 i * 4, dev->saved_config_space[i]);
1656 }
1657 dev->state_saved = true;
1658
1659 i = pci_save_pcie_state(dev);
1660 if (i != 0)
1661 return i;
1662
1663 i = pci_save_pcix_state(dev);
1664 if (i != 0)
1665 return i;
1666
1667 pci_save_ltr_state(dev);
1668 pci_save_dpc_state(dev);
1669 pci_save_aer_state(dev);
1670 pci_save_ptm_state(dev);
1671 return pci_save_vc_state(dev);
1672}
1673EXPORT_SYMBOL(pci_save_state);
1674
1675static void pci_restore_config_dword(struct pci_dev *pdev, int offset,
1676 u32 saved_val, int retry, bool force)
1677{
1678 u32 val;
1679
1680 pci_read_config_dword(pdev, offset, &val);
1681 if (!force && val == saved_val)
1682 return;
1683
1684 for (;;) {
1685 pci_dbg(pdev, "restoring config space at offset %#x (was %#x, writing %#x)\n",
1686 offset, val, saved_val);
1687 pci_write_config_dword(pdev, offset, saved_val);
1688 if (retry-- <= 0)
1689 return;
1690
1691 pci_read_config_dword(pdev, offset, &val);
1692 if (val == saved_val)
1693 return;
1694
1695 mdelay(1);
1696 }
1697}
1698
1699static void pci_restore_config_space_range(struct pci_dev *pdev,
1700 int start, int end, int retry,
1701 bool force)
1702{
1703 int index;
1704
1705 for (index = end; index >= start; index--)
1706 pci_restore_config_dword(pdev, 4 * index,
1707 pdev->saved_config_space[index],
1708 retry, force);
1709}
1710
1711static void pci_restore_config_space(struct pci_dev *pdev)
1712{
1713 if (pdev->hdr_type == PCI_HEADER_TYPE_NORMAL) {
1714 pci_restore_config_space_range(pdev, 10, 15, 0, false);
1715 /* Restore BARs before the command register. */
1716 pci_restore_config_space_range(pdev, 4, 9, 10, false);
1717 pci_restore_config_space_range(pdev, 0, 3, 0, false);
1718 } else if (pdev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
1719 pci_restore_config_space_range(pdev, 12, 15, 0, false);
1720
1721 /*
1722 * Force rewriting of prefetch registers to avoid S3 resume
1723 * issues on Intel PCI bridges that occur when these
1724 * registers are not explicitly written.
1725 */
1726 pci_restore_config_space_range(pdev, 9, 11, 0, true);
1727 pci_restore_config_space_range(pdev, 0, 8, 0, false);
1728 } else {
1729 pci_restore_config_space_range(pdev, 0, 15, 0, false);
1730 }
1731}
1732
1733static void pci_restore_rebar_state(struct pci_dev *pdev)
1734{
1735 unsigned int pos, nbars, i;
1736 u32 ctrl;
1737
1738 pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR);
1739 if (!pos)
1740 return;
1741
1742 pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
1743 nbars = (ctrl & PCI_REBAR_CTRL_NBAR_MASK) >>
1744 PCI_REBAR_CTRL_NBAR_SHIFT;
1745
1746 for (i = 0; i < nbars; i++, pos += 8) {
1747 struct resource *res;
1748 int bar_idx, size;
1749
1750 pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
1751 bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX;
1752 res = pdev->resource + bar_idx;
1753 size = pci_rebar_bytes_to_size(resource_size(res));
1754 ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE;
1755 ctrl |= size << PCI_REBAR_CTRL_BAR_SHIFT;
1756 pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl);
1757 }
1758}
1759
1760/**
1761 * pci_restore_state - Restore the saved state of a PCI device
1762 * @dev: PCI device that we're dealing with
1763 */
1764void pci_restore_state(struct pci_dev *dev)
1765{
1766 if (!dev->state_saved)
1767 return;
1768
1769 /*
1770 * Restore max latencies (in the LTR capability) before enabling
1771 * LTR itself (in the PCIe capability).
1772 */
1773 pci_restore_ltr_state(dev);
1774
1775 pci_restore_pcie_state(dev);
1776 pci_restore_pasid_state(dev);
1777 pci_restore_pri_state(dev);
1778 pci_restore_ats_state(dev);
1779 pci_restore_vc_state(dev);
1780 pci_restore_rebar_state(dev);
1781 pci_restore_dpc_state(dev);
1782 pci_restore_ptm_state(dev);
1783
1784 pci_aer_clear_status(dev);
1785 pci_restore_aer_state(dev);
1786
1787 pci_restore_config_space(dev);
1788
1789 pci_restore_pcix_state(dev);
1790 pci_restore_msi_state(dev);
1791
1792 /* Restore ACS and IOV configuration state */
1793 pci_enable_acs(dev);
1794 pci_restore_iov_state(dev);
1795
1796 dev->state_saved = false;
1797}
1798EXPORT_SYMBOL(pci_restore_state);
1799
1800struct pci_saved_state {
1801 u32 config_space[16];
1802 struct pci_cap_saved_data cap[];
1803};
1804
1805/**
1806 * pci_store_saved_state - Allocate and return an opaque struct containing
1807 * the device saved state.
1808 * @dev: PCI device that we're dealing with
1809 *
1810 * Return NULL if no state or error.
1811 */
1812struct pci_saved_state *pci_store_saved_state(struct pci_dev *dev)
1813{
1814 struct pci_saved_state *state;
1815 struct pci_cap_saved_state *tmp;
1816 struct pci_cap_saved_data *cap;
1817 size_t size;
1818
1819 if (!dev->state_saved)
1820 return NULL;
1821
1822 size = sizeof(*state) + sizeof(struct pci_cap_saved_data);
1823
1824 hlist_for_each_entry(tmp, &dev->saved_cap_space, next)
1825 size += sizeof(struct pci_cap_saved_data) + tmp->cap.size;
1826
1827 state = kzalloc(size, GFP_KERNEL);
1828 if (!state)
1829 return NULL;
1830
1831 memcpy(state->config_space, dev->saved_config_space,
1832 sizeof(state->config_space));
1833
1834 cap = state->cap;
1835 hlist_for_each_entry(tmp, &dev->saved_cap_space, next) {
1836 size_t len = sizeof(struct pci_cap_saved_data) + tmp->cap.size;
1837 memcpy(cap, &tmp->cap, len);
1838 cap = (struct pci_cap_saved_data *)((u8 *)cap + len);
1839 }
1840 /* Empty cap_save terminates list */
1841
1842 return state;
1843}
1844EXPORT_SYMBOL_GPL(pci_store_saved_state);
1845
1846/**
1847 * pci_load_saved_state - Reload the provided save state into struct pci_dev.
1848 * @dev: PCI device that we're dealing with
1849 * @state: Saved state returned from pci_store_saved_state()
1850 */
1851int pci_load_saved_state(struct pci_dev *dev,
1852 struct pci_saved_state *state)
1853{
1854 struct pci_cap_saved_data *cap;
1855
1856 dev->state_saved = false;
1857
1858 if (!state)
1859 return 0;
1860
1861 memcpy(dev->saved_config_space, state->config_space,
1862 sizeof(state->config_space));
1863
1864 cap = state->cap;
1865 while (cap->size) {
1866 struct pci_cap_saved_state *tmp;
1867
1868 tmp = _pci_find_saved_cap(dev, cap->cap_nr, cap->cap_extended);
1869 if (!tmp || tmp->cap.size != cap->size)
1870 return -EINVAL;
1871
1872 memcpy(tmp->cap.data, cap->data, tmp->cap.size);
1873 cap = (struct pci_cap_saved_data *)((u8 *)cap +
1874 sizeof(struct pci_cap_saved_data) + cap->size);
1875 }
1876
1877 dev->state_saved = true;
1878 return 0;
1879}
1880EXPORT_SYMBOL_GPL(pci_load_saved_state);
1881
1882/**
1883 * pci_load_and_free_saved_state - Reload the save state pointed to by state,
1884 * and free the memory allocated for it.
1885 * @dev: PCI device that we're dealing with
1886 * @state: Pointer to saved state returned from pci_store_saved_state()
1887 */
1888int pci_load_and_free_saved_state(struct pci_dev *dev,
1889 struct pci_saved_state **state)
1890{
1891 int ret = pci_load_saved_state(dev, *state);
1892 kfree(*state);
1893 *state = NULL;
1894 return ret;
1895}
1896EXPORT_SYMBOL_GPL(pci_load_and_free_saved_state);
1897
1898int __weak pcibios_enable_device(struct pci_dev *dev, int bars)
1899{
1900 return pci_enable_resources(dev, bars);
1901}
1902
1903static int do_pci_enable_device(struct pci_dev *dev, int bars)
1904{
1905 int err;
1906 struct pci_dev *bridge;
1907 u16 cmd;
1908 u8 pin;
1909
1910 err = pci_set_power_state(dev, PCI_D0);
1911 if (err < 0 && err != -EIO)
1912 return err;
1913
1914 bridge = pci_upstream_bridge(dev);
1915 if (bridge)
1916 pcie_aspm_powersave_config_link(bridge);
1917
1918 err = pcibios_enable_device(dev, bars);
1919 if (err < 0)
1920 return err;
1921 pci_fixup_device(pci_fixup_enable, dev);
1922
1923 if (dev->msi_enabled || dev->msix_enabled)
1924 return 0;
1925
1926 pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
1927 if (pin) {
1928 pci_read_config_word(dev, PCI_COMMAND, &cmd);
1929 if (cmd & PCI_COMMAND_INTX_DISABLE)
1930 pci_write_config_word(dev, PCI_COMMAND,
1931 cmd & ~PCI_COMMAND_INTX_DISABLE);
1932 }
1933
1934 return 0;
1935}
1936
1937/**
1938 * pci_reenable_device - Resume abandoned device
1939 * @dev: PCI device to be resumed
1940 *
1941 * NOTE: This function is a backend of pci_default_resume() and is not supposed
1942 * to be called by normal code, write proper resume handler and use it instead.
1943 */
1944int pci_reenable_device(struct pci_dev *dev)
1945{
1946 if (pci_is_enabled(dev))
1947 return do_pci_enable_device(dev, (1 << PCI_NUM_RESOURCES) - 1);
1948 return 0;
1949}
1950EXPORT_SYMBOL(pci_reenable_device);
1951
1952static void pci_enable_bridge(struct pci_dev *dev)
1953{
1954 struct pci_dev *bridge;
1955 int retval;
1956
1957 bridge = pci_upstream_bridge(dev);
1958 if (bridge)
1959 pci_enable_bridge(bridge);
1960
1961 if (pci_is_enabled(dev)) {
1962 if (!dev->is_busmaster)
1963 pci_set_master(dev);
1964 return;
1965 }
1966
1967 retval = pci_enable_device(dev);
1968 if (retval)
1969 pci_err(dev, "Error enabling bridge (%d), continuing\n",
1970 retval);
1971 pci_set_master(dev);
1972}
1973
1974static int pci_enable_device_flags(struct pci_dev *dev, unsigned long flags)
1975{
1976 struct pci_dev *bridge;
1977 int err;
1978 int i, bars = 0;
1979
1980 /*
1981 * Power state could be unknown at this point, either due to a fresh
1982 * boot or a device removal call. So get the current power state
1983 * so that things like MSI message writing will behave as expected
1984 * (e.g. if the device really is in D0 at enable time).
1985 */
1986 pci_update_current_state(dev, dev->current_state);
1987
1988 if (atomic_inc_return(&dev->enable_cnt) > 1)
1989 return 0; /* already enabled */
1990
1991 bridge = pci_upstream_bridge(dev);
1992 if (bridge)
1993 pci_enable_bridge(bridge);
1994
1995 /* only skip sriov related */
1996 for (i = 0; i <= PCI_ROM_RESOURCE; i++)
1997 if (dev->resource[i].flags & flags)
1998 bars |= (1 << i);
1999 for (i = PCI_BRIDGE_RESOURCES; i < DEVICE_COUNT_RESOURCE; i++)
2000 if (dev->resource[i].flags & flags)
2001 bars |= (1 << i);
2002
2003 err = do_pci_enable_device(dev, bars);
2004 if (err < 0)
2005 atomic_dec(&dev->enable_cnt);
2006 return err;
2007}
2008
2009/**
2010 * pci_enable_device_io - Initialize a device for use with IO space
2011 * @dev: PCI device to be initialized
2012 *
2013 * Initialize device before it's used by a driver. Ask low-level code
2014 * to enable I/O resources. Wake up the device if it was suspended.
2015 * Beware, this function can fail.
2016 */
2017int pci_enable_device_io(struct pci_dev *dev)
2018{
2019 return pci_enable_device_flags(dev, IORESOURCE_IO);
2020}
2021EXPORT_SYMBOL(pci_enable_device_io);
2022
2023/**
2024 * pci_enable_device_mem - Initialize a device for use with Memory space
2025 * @dev: PCI device to be initialized
2026 *
2027 * Initialize device before it's used by a driver. Ask low-level code
2028 * to enable Memory resources. Wake up the device if it was suspended.
2029 * Beware, this function can fail.
2030 */
2031int pci_enable_device_mem(struct pci_dev *dev)
2032{
2033 return pci_enable_device_flags(dev, IORESOURCE_MEM);
2034}
2035EXPORT_SYMBOL(pci_enable_device_mem);
2036
2037/**
2038 * pci_enable_device - Initialize device before it's used by a driver.
2039 * @dev: PCI device to be initialized
2040 *
2041 * Initialize device before it's used by a driver. Ask low-level code
2042 * to enable I/O and memory. Wake up the device if it was suspended.
2043 * Beware, this function can fail.
2044 *
2045 * Note we don't actually enable the device many times if we call
2046 * this function repeatedly (we just increment the count).
2047 */
2048int pci_enable_device(struct pci_dev *dev)
2049{
2050 return pci_enable_device_flags(dev, IORESOURCE_MEM | IORESOURCE_IO);
2051}
2052EXPORT_SYMBOL(pci_enable_device);
2053
2054/*
2055 * Managed PCI resources. This manages device on/off, INTx/MSI/MSI-X
2056 * on/off and BAR regions. pci_dev itself records MSI/MSI-X status, so
2057 * there's no need to track it separately. pci_devres is initialized
2058 * when a device is enabled using managed PCI device enable interface.
2059 */
2060struct pci_devres {
2061 unsigned int enabled:1;
2062 unsigned int pinned:1;
2063 unsigned int orig_intx:1;
2064 unsigned int restore_intx:1;
2065 unsigned int mwi:1;
2066 u32 region_mask;
2067};
2068
2069static void pcim_release(struct device *gendev, void *res)
2070{
2071 struct pci_dev *dev = to_pci_dev(gendev);
2072 struct pci_devres *this = res;
2073 int i;
2074
2075 for (i = 0; i < DEVICE_COUNT_RESOURCE; i++)
2076 if (this->region_mask & (1 << i))
2077 pci_release_region(dev, i);
2078
2079 if (this->mwi)
2080 pci_clear_mwi(dev);
2081
2082 if (this->restore_intx)
2083 pci_intx(dev, this->orig_intx);
2084
2085 if (this->enabled && !this->pinned)
2086 pci_disable_device(dev);
2087}
2088
2089static struct pci_devres *get_pci_dr(struct pci_dev *pdev)
2090{
2091 struct pci_devres *dr, *new_dr;
2092
2093 dr = devres_find(&pdev->dev, pcim_release, NULL, NULL);
2094 if (dr)
2095 return dr;
2096
2097 new_dr = devres_alloc(pcim_release, sizeof(*new_dr), GFP_KERNEL);
2098 if (!new_dr)
2099 return NULL;
2100 return devres_get(&pdev->dev, new_dr, NULL, NULL);
2101}
2102
2103static struct pci_devres *find_pci_dr(struct pci_dev *pdev)
2104{
2105 if (pci_is_managed(pdev))
2106 return devres_find(&pdev->dev, pcim_release, NULL, NULL);
2107 return NULL;
2108}
2109
2110/**
2111 * pcim_enable_device - Managed pci_enable_device()
2112 * @pdev: PCI device to be initialized
2113 *
2114 * Managed pci_enable_device().
2115 */
2116int pcim_enable_device(struct pci_dev *pdev)
2117{
2118 struct pci_devres *dr;
2119 int rc;
2120
2121 dr = get_pci_dr(pdev);
2122 if (unlikely(!dr))
2123 return -ENOMEM;
2124 if (dr->enabled)
2125 return 0;
2126
2127 rc = pci_enable_device(pdev);
2128 if (!rc) {
2129 pdev->is_managed = 1;
2130 dr->enabled = 1;
2131 }
2132 return rc;
2133}
2134EXPORT_SYMBOL(pcim_enable_device);
2135
2136/**
2137 * pcim_pin_device - Pin managed PCI device
2138 * @pdev: PCI device to pin
2139 *
2140 * Pin managed PCI device @pdev. Pinned device won't be disabled on
2141 * driver detach. @pdev must have been enabled with
2142 * pcim_enable_device().
2143 */
2144void pcim_pin_device(struct pci_dev *pdev)
2145{
2146 struct pci_devres *dr;
2147
2148 dr = find_pci_dr(pdev);
2149 WARN_ON(!dr || !dr->enabled);
2150 if (dr)
2151 dr->pinned = 1;
2152}
2153EXPORT_SYMBOL(pcim_pin_device);
2154
2155/*
2156 * pcibios_device_add - provide arch specific hooks when adding device dev
2157 * @dev: the PCI device being added
2158 *
2159 * Permits the platform to provide architecture specific functionality when
2160 * devices are added. This is the default implementation. Architecture
2161 * implementations can override this.
2162 */
2163int __weak pcibios_device_add(struct pci_dev *dev)
2164{
2165 return 0;
2166}
2167
2168/**
2169 * pcibios_release_device - provide arch specific hooks when releasing
2170 * device dev
2171 * @dev: the PCI device being released
2172 *
2173 * Permits the platform to provide architecture specific functionality when
2174 * devices are released. This is the default implementation. Architecture
2175 * implementations can override this.
2176 */
2177void __weak pcibios_release_device(struct pci_dev *dev) {}
2178
2179/**
2180 * pcibios_disable_device - disable arch specific PCI resources for device dev
2181 * @dev: the PCI device to disable
2182 *
2183 * Disables architecture specific PCI resources for the device. This
2184 * is the default implementation. Architecture implementations can
2185 * override this.
2186 */
2187void __weak pcibios_disable_device(struct pci_dev *dev) {}
2188
2189/**
2190 * pcibios_penalize_isa_irq - penalize an ISA IRQ
2191 * @irq: ISA IRQ to penalize
2192 * @active: IRQ active or not
2193 *
2194 * Permits the platform to provide architecture-specific functionality when
2195 * penalizing ISA IRQs. This is the default implementation. Architecture
2196 * implementations can override this.
2197 */
2198void __weak pcibios_penalize_isa_irq(int irq, int active) {}
2199
2200static void do_pci_disable_device(struct pci_dev *dev)
2201{
2202 u16 pci_command;
2203
2204 pci_read_config_word(dev, PCI_COMMAND, &pci_command);
2205 if (pci_command & PCI_COMMAND_MASTER) {
2206 pci_command &= ~PCI_COMMAND_MASTER;
2207 pci_write_config_word(dev, PCI_COMMAND, pci_command);
2208 }
2209
2210 pcibios_disable_device(dev);
2211}
2212
2213/**
2214 * pci_disable_enabled_device - Disable device without updating enable_cnt
2215 * @dev: PCI device to disable
2216 *
2217 * NOTE: This function is a backend of PCI power management routines and is
2218 * not supposed to be called drivers.
2219 */
2220void pci_disable_enabled_device(struct pci_dev *dev)
2221{
2222 if (pci_is_enabled(dev))
2223 do_pci_disable_device(dev);
2224}
2225
2226/**
2227 * pci_disable_device - Disable PCI device after use
2228 * @dev: PCI device to be disabled
2229 *
2230 * Signal to the system that the PCI device is not in use by the system
2231 * anymore. This only involves disabling PCI bus-mastering, if active.
2232 *
2233 * Note we don't actually disable the device until all callers of
2234 * pci_enable_device() have called pci_disable_device().
2235 */
2236void pci_disable_device(struct pci_dev *dev)
2237{
2238 struct pci_devres *dr;
2239
2240 dr = find_pci_dr(dev);
2241 if (dr)
2242 dr->enabled = 0;
2243
2244 dev_WARN_ONCE(&dev->dev, atomic_read(&dev->enable_cnt) <= 0,
2245 "disabling already-disabled device");
2246
2247 if (atomic_dec_return(&dev->enable_cnt) != 0)
2248 return;
2249
2250 do_pci_disable_device(dev);
2251
2252 dev->is_busmaster = 0;
2253}
2254EXPORT_SYMBOL(pci_disable_device);
2255
2256/**
2257 * pcibios_set_pcie_reset_state - set reset state for device dev
2258 * @dev: the PCIe device reset
2259 * @state: Reset state to enter into
2260 *
2261 * Set the PCIe reset state for the device. This is the default
2262 * implementation. Architecture implementations can override this.
2263 */
2264int __weak pcibios_set_pcie_reset_state(struct pci_dev *dev,
2265 enum pcie_reset_state state)
2266{
2267 return -EINVAL;
2268}
2269
2270/**
2271 * pci_set_pcie_reset_state - set reset state for device dev
2272 * @dev: the PCIe device reset
2273 * @state: Reset state to enter into
2274 *
2275 * Sets the PCI reset state for the device.
2276 */
2277int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state)
2278{
2279 return pcibios_set_pcie_reset_state(dev, state);
2280}
2281EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state);
2282
2283#ifdef CONFIG_PCIEAER
2284void pcie_clear_device_status(struct pci_dev *dev)
2285{
2286 u16 sta;
2287
2288 pcie_capability_read_word(dev, PCI_EXP_DEVSTA, &sta);
2289 pcie_capability_write_word(dev, PCI_EXP_DEVSTA, sta);
2290}
2291#endif
2292
2293/**
2294 * pcie_clear_root_pme_status - Clear root port PME interrupt status.
2295 * @dev: PCIe root port or event collector.
2296 */
2297void pcie_clear_root_pme_status(struct pci_dev *dev)
2298{
2299 pcie_capability_set_dword(dev, PCI_EXP_RTSTA, PCI_EXP_RTSTA_PME);
2300}
2301
2302/**
2303 * pci_check_pme_status - Check if given device has generated PME.
2304 * @dev: Device to check.
2305 *
2306 * Check the PME status of the device and if set, clear it and clear PME enable
2307 * (if set). Return 'true' if PME status and PME enable were both set or
2308 * 'false' otherwise.
2309 */
2310bool pci_check_pme_status(struct pci_dev *dev)
2311{
2312 int pmcsr_pos;
2313 u16 pmcsr;
2314 bool ret = false;
2315
2316 if (!dev->pm_cap)
2317 return false;
2318
2319 pmcsr_pos = dev->pm_cap + PCI_PM_CTRL;
2320 pci_read_config_word(dev, pmcsr_pos, &pmcsr);
2321 if (!(pmcsr & PCI_PM_CTRL_PME_STATUS))
2322 return false;
2323
2324 /* Clear PME status. */
2325 pmcsr |= PCI_PM_CTRL_PME_STATUS;
2326 if (pmcsr & PCI_PM_CTRL_PME_ENABLE) {
2327 /* Disable PME to avoid interrupt flood. */
2328 pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
2329 ret = true;
2330 }
2331
2332 pci_write_config_word(dev, pmcsr_pos, pmcsr);
2333
2334 return ret;
2335}
2336
2337/**
2338 * pci_pme_wakeup - Wake up a PCI device if its PME Status bit is set.
2339 * @dev: Device to handle.
2340 * @pme_poll_reset: Whether or not to reset the device's pme_poll flag.
2341 *
2342 * Check if @dev has generated PME and queue a resume request for it in that
2343 * case.
2344 */
2345static int pci_pme_wakeup(struct pci_dev *dev, void *pme_poll_reset)
2346{
2347 if (pme_poll_reset && dev->pme_poll)
2348 dev->pme_poll = false;
2349
2350 if (pci_check_pme_status(dev)) {
2351 pci_wakeup_event(dev);
2352 pm_request_resume(&dev->dev);
2353 }
2354 return 0;
2355}
2356
2357/**
2358 * pci_pme_wakeup_bus - Walk given bus and wake up devices on it, if necessary.
2359 * @bus: Top bus of the subtree to walk.
2360 */
2361void pci_pme_wakeup_bus(struct pci_bus *bus)
2362{
2363 if (bus)
2364 pci_walk_bus(bus, pci_pme_wakeup, (void *)true);
2365}
2366
2367
2368/**
2369 * pci_pme_capable - check the capability of PCI device to generate PME#
2370 * @dev: PCI device to handle.
2371 * @state: PCI state from which device will issue PME#.
2372 */
2373bool pci_pme_capable(struct pci_dev *dev, pci_power_t state)
2374{
2375 if (!dev->pm_cap)
2376 return false;
2377
2378 return !!(dev->pme_support & (1 << state));
2379}
2380EXPORT_SYMBOL(pci_pme_capable);
2381
2382static void pci_pme_list_scan(struct work_struct *work)
2383{
2384 struct pci_pme_device *pme_dev, *n;
2385
2386 mutex_lock(&pci_pme_list_mutex);
2387 list_for_each_entry_safe(pme_dev, n, &pci_pme_list, list) {
2388 if (pme_dev->dev->pme_poll) {
2389 struct pci_dev *bridge;
2390
2391 bridge = pme_dev->dev->bus->self;
2392 /*
2393 * If bridge is in low power state, the
2394 * configuration space of subordinate devices
2395 * may be not accessible
2396 */
2397 if (bridge && bridge->current_state != PCI_D0)
2398 continue;
2399 /*
2400 * If the device is in D3cold it should not be
2401 * polled either.
2402 */
2403 if (pme_dev->dev->current_state == PCI_D3cold)
2404 continue;
2405
2406 pci_pme_wakeup(pme_dev->dev, NULL);
2407 } else {
2408 list_del(&pme_dev->list);
2409 kfree(pme_dev);
2410 }
2411 }
2412 if (!list_empty(&pci_pme_list))
2413 queue_delayed_work(system_freezable_wq, &pci_pme_work,
2414 msecs_to_jiffies(PME_TIMEOUT));
2415 mutex_unlock(&pci_pme_list_mutex);
2416}
2417
2418static void __pci_pme_active(struct pci_dev *dev, bool enable)
2419{
2420 u16 pmcsr;
2421
2422 if (!dev->pme_support)
2423 return;
2424
2425 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
2426 /* Clear PME_Status by writing 1 to it and enable PME# */
2427 pmcsr |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE;
2428 if (!enable)
2429 pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
2430
2431 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
2432}
2433
2434/**
2435 * pci_pme_restore - Restore PME configuration after config space restore.
2436 * @dev: PCI device to update.
2437 */
2438void pci_pme_restore(struct pci_dev *dev)
2439{
2440 u16 pmcsr;
2441
2442 if (!dev->pme_support)
2443 return;
2444
2445 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
2446 if (dev->wakeup_prepared) {
2447 pmcsr |= PCI_PM_CTRL_PME_ENABLE;
2448 pmcsr &= ~PCI_PM_CTRL_PME_STATUS;
2449 } else {
2450 pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
2451 pmcsr |= PCI_PM_CTRL_PME_STATUS;
2452 }
2453 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
2454}
2455
2456/**
2457 * pci_pme_active - enable or disable PCI device's PME# function
2458 * @dev: PCI device to handle.
2459 * @enable: 'true' to enable PME# generation; 'false' to disable it.
2460 *
2461 * The caller must verify that the device is capable of generating PME# before
2462 * calling this function with @enable equal to 'true'.
2463 */
2464void pci_pme_active(struct pci_dev *dev, bool enable)
2465{
2466 __pci_pme_active(dev, enable);
2467
2468 /*
2469 * PCI (as opposed to PCIe) PME requires that the device have
2470 * its PME# line hooked up correctly. Not all hardware vendors
2471 * do this, so the PME never gets delivered and the device
2472 * remains asleep. The easiest way around this is to
2473 * periodically walk the list of suspended devices and check
2474 * whether any have their PME flag set. The assumption is that
2475 * we'll wake up often enough anyway that this won't be a huge
2476 * hit, and the power savings from the devices will still be a
2477 * win.
2478 *
2479 * Although PCIe uses in-band PME message instead of PME# line
2480 * to report PME, PME does not work for some PCIe devices in
2481 * reality. For example, there are devices that set their PME
2482 * status bits, but don't really bother to send a PME message;
2483 * there are PCI Express Root Ports that don't bother to
2484 * trigger interrupts when they receive PME messages from the
2485 * devices below. So PME poll is used for PCIe devices too.
2486 */
2487
2488 if (dev->pme_poll) {
2489 struct pci_pme_device *pme_dev;
2490 if (enable) {
2491 pme_dev = kmalloc(sizeof(struct pci_pme_device),
2492 GFP_KERNEL);
2493 if (!pme_dev) {
2494 pci_warn(dev, "can't enable PME#\n");
2495 return;
2496 }
2497 pme_dev->dev = dev;
2498 mutex_lock(&pci_pme_list_mutex);
2499 list_add(&pme_dev->list, &pci_pme_list);
2500 if (list_is_singular(&pci_pme_list))
2501 queue_delayed_work(system_freezable_wq,
2502 &pci_pme_work,
2503 msecs_to_jiffies(PME_TIMEOUT));
2504 mutex_unlock(&pci_pme_list_mutex);
2505 } else {
2506 mutex_lock(&pci_pme_list_mutex);
2507 list_for_each_entry(pme_dev, &pci_pme_list, list) {
2508 if (pme_dev->dev == dev) {
2509 list_del(&pme_dev->list);
2510 kfree(pme_dev);
2511 break;
2512 }
2513 }
2514 mutex_unlock(&pci_pme_list_mutex);
2515 }
2516 }
2517
2518 pci_dbg(dev, "PME# %s\n", enable ? "enabled" : "disabled");
2519}
2520EXPORT_SYMBOL(pci_pme_active);
2521
2522/**
2523 * __pci_enable_wake - enable PCI device as wakeup event source
2524 * @dev: PCI device affected
2525 * @state: PCI state from which device will issue wakeup events
2526 * @enable: True to enable event generation; false to disable
2527 *
2528 * This enables the device as a wakeup event source, or disables it.
2529 * When such events involves platform-specific hooks, those hooks are
2530 * called automatically by this routine.
2531 *
2532 * Devices with legacy power management (no standard PCI PM capabilities)
2533 * always require such platform hooks.
2534 *
2535 * RETURN VALUE:
2536 * 0 is returned on success
2537 * -EINVAL is returned if device is not supposed to wake up the system
2538 * Error code depending on the platform is returned if both the platform and
2539 * the native mechanism fail to enable the generation of wake-up events
2540 */
2541static int __pci_enable_wake(struct pci_dev *dev, pci_power_t state, bool enable)
2542{
2543 int ret = 0;
2544
2545 /*
2546 * Bridges that are not power-manageable directly only signal
2547 * wakeup on behalf of subordinate devices which is set up
2548 * elsewhere, so skip them. However, bridges that are
2549 * power-manageable may signal wakeup for themselves (for example,
2550 * on a hotplug event) and they need to be covered here.
2551 */
2552 if (!pci_power_manageable(dev))
2553 return 0;
2554
2555 /* Don't do the same thing twice in a row for one device. */
2556 if (!!enable == !!dev->wakeup_prepared)
2557 return 0;
2558
2559 /*
2560 * According to "PCI System Architecture" 4th ed. by Tom Shanley & Don
2561 * Anderson we should be doing PME# wake enable followed by ACPI wake
2562 * enable. To disable wake-up we call the platform first, for symmetry.
2563 */
2564
2565 if (enable) {
2566 int error;
2567
2568 /*
2569 * Enable PME signaling if the device can signal PME from
2570 * D3cold regardless of whether or not it can signal PME from
2571 * the current target state, because that will allow it to
2572 * signal PME when the hierarchy above it goes into D3cold and
2573 * the device itself ends up in D3cold as a result of that.
2574 */
2575 if (pci_pme_capable(dev, state) || pci_pme_capable(dev, PCI_D3cold))
2576 pci_pme_active(dev, true);
2577 else
2578 ret = 1;
2579 error = platform_pci_set_wakeup(dev, true);
2580 if (ret)
2581 ret = error;
2582 if (!ret)
2583 dev->wakeup_prepared = true;
2584 } else {
2585 platform_pci_set_wakeup(dev, false);
2586 pci_pme_active(dev, false);
2587 dev->wakeup_prepared = false;
2588 }
2589
2590 return ret;
2591}
2592
2593/**
2594 * pci_enable_wake - change wakeup settings for a PCI device
2595 * @pci_dev: Target device
2596 * @state: PCI state from which device will issue wakeup events
2597 * @enable: Whether or not to enable event generation
2598 *
2599 * If @enable is set, check device_may_wakeup() for the device before calling
2600 * __pci_enable_wake() for it.
2601 */
2602int pci_enable_wake(struct pci_dev *pci_dev, pci_power_t state, bool enable)
2603{
2604 if (enable && !device_may_wakeup(&pci_dev->dev))
2605 return -EINVAL;
2606
2607 return __pci_enable_wake(pci_dev, state, enable);
2608}
2609EXPORT_SYMBOL(pci_enable_wake);
2610
2611/**
2612 * pci_wake_from_d3 - enable/disable device to wake up from D3_hot or D3_cold
2613 * @dev: PCI device to prepare
2614 * @enable: True to enable wake-up event generation; false to disable
2615 *
2616 * Many drivers want the device to wake up the system from D3_hot or D3_cold
2617 * and this function allows them to set that up cleanly - pci_enable_wake()
2618 * should not be called twice in a row to enable wake-up due to PCI PM vs ACPI
2619 * ordering constraints.
2620 *
2621 * This function only returns error code if the device is not allowed to wake
2622 * up the system from sleep or it is not capable of generating PME# from both
2623 * D3_hot and D3_cold and the platform is unable to enable wake-up power for it.
2624 */
2625int pci_wake_from_d3(struct pci_dev *dev, bool enable)
2626{
2627 return pci_pme_capable(dev, PCI_D3cold) ?
2628 pci_enable_wake(dev, PCI_D3cold, enable) :
2629 pci_enable_wake(dev, PCI_D3hot, enable);
2630}
2631EXPORT_SYMBOL(pci_wake_from_d3);
2632
2633/**
2634 * pci_target_state - find an appropriate low power state for a given PCI dev
2635 * @dev: PCI device
2636 * @wakeup: Whether or not wakeup functionality will be enabled for the device.
2637 *
2638 * Use underlying platform code to find a supported low power state for @dev.
2639 * If the platform can't manage @dev, return the deepest state from which it
2640 * can generate wake events, based on any available PME info.
2641 */
2642static pci_power_t pci_target_state(struct pci_dev *dev, bool wakeup)
2643{
2644 if (platform_pci_power_manageable(dev)) {
2645 /*
2646 * Call the platform to find the target state for the device.
2647 */
2648 pci_power_t state = platform_pci_choose_state(dev);
2649
2650 switch (state) {
2651 case PCI_POWER_ERROR:
2652 case PCI_UNKNOWN:
2653 return PCI_D3hot;
2654
2655 case PCI_D1:
2656 case PCI_D2:
2657 if (pci_no_d1d2(dev))
2658 return PCI_D3hot;
2659 }
2660
2661 return state;
2662 }
2663
2664 /*
2665 * If the device is in D3cold even though it's not power-manageable by
2666 * the platform, it may have been powered down by non-standard means.
2667 * Best to let it slumber.
2668 */
2669 if (dev->current_state == PCI_D3cold)
2670 return PCI_D3cold;
2671 else if (!dev->pm_cap)
2672 return PCI_D0;
2673
2674 if (wakeup && dev->pme_support) {
2675 pci_power_t state = PCI_D3hot;
2676
2677 /*
2678 * Find the deepest state from which the device can generate
2679 * PME#.
2680 */
2681 while (state && !(dev->pme_support & (1 << state)))
2682 state--;
2683
2684 if (state)
2685 return state;
2686 else if (dev->pme_support & 1)
2687 return PCI_D0;
2688 }
2689
2690 return PCI_D3hot;
2691}
2692
2693/**
2694 * pci_prepare_to_sleep - prepare PCI device for system-wide transition
2695 * into a sleep state
2696 * @dev: Device to handle.
2697 *
2698 * Choose the power state appropriate for the device depending on whether
2699 * it can wake up the system and/or is power manageable by the platform
2700 * (PCI_D3hot is the default) and put the device into that state.
2701 */
2702int pci_prepare_to_sleep(struct pci_dev *dev)
2703{
2704 bool wakeup = device_may_wakeup(&dev->dev);
2705 pci_power_t target_state = pci_target_state(dev, wakeup);
2706 int error;
2707
2708 if (target_state == PCI_POWER_ERROR)
2709 return -EIO;
2710
2711 pci_enable_wake(dev, target_state, wakeup);
2712
2713 error = pci_set_power_state(dev, target_state);
2714
2715 if (error)
2716 pci_enable_wake(dev, target_state, false);
2717
2718 return error;
2719}
2720EXPORT_SYMBOL(pci_prepare_to_sleep);
2721
2722/**
2723 * pci_back_from_sleep - turn PCI device on during system-wide transition
2724 * into working state
2725 * @dev: Device to handle.
2726 *
2727 * Disable device's system wake-up capability and put it into D0.
2728 */
2729int pci_back_from_sleep(struct pci_dev *dev)
2730{
2731 int ret = pci_set_power_state(dev, PCI_D0);
2732
2733 if (ret)
2734 return ret;
2735
2736 pci_enable_wake(dev, PCI_D0, false);
2737 return 0;
2738}
2739EXPORT_SYMBOL(pci_back_from_sleep);
2740
2741/**
2742 * pci_finish_runtime_suspend - Carry out PCI-specific part of runtime suspend.
2743 * @dev: PCI device being suspended.
2744 *
2745 * Prepare @dev to generate wake-up events at run time and put it into a low
2746 * power state.
2747 */
2748int pci_finish_runtime_suspend(struct pci_dev *dev)
2749{
2750 pci_power_t target_state;
2751 int error;
2752
2753 target_state = pci_target_state(dev, device_can_wakeup(&dev->dev));
2754 if (target_state == PCI_POWER_ERROR)
2755 return -EIO;
2756
2757 __pci_enable_wake(dev, target_state, pci_dev_run_wake(dev));
2758
2759 error = pci_set_power_state(dev, target_state);
2760
2761 if (error)
2762 pci_enable_wake(dev, target_state, false);
2763
2764 return error;
2765}
2766
2767/**
2768 * pci_dev_run_wake - Check if device can generate run-time wake-up events.
2769 * @dev: Device to check.
2770 *
2771 * Return true if the device itself is capable of generating wake-up events
2772 * (through the platform or using the native PCIe PME) or if the device supports
2773 * PME and one of its upstream bridges can generate wake-up events.
2774 */
2775bool pci_dev_run_wake(struct pci_dev *dev)
2776{
2777 struct pci_bus *bus = dev->bus;
2778
2779 if (!dev->pme_support)
2780 return false;
2781
2782 /* PME-capable in principle, but not from the target power state */
2783 if (!pci_pme_capable(dev, pci_target_state(dev, true)))
2784 return false;
2785
2786 if (device_can_wakeup(&dev->dev))
2787 return true;
2788
2789 while (bus->parent) {
2790 struct pci_dev *bridge = bus->self;
2791
2792 if (device_can_wakeup(&bridge->dev))
2793 return true;
2794
2795 bus = bus->parent;
2796 }
2797
2798 /* We have reached the root bus. */
2799 if (bus->bridge)
2800 return device_can_wakeup(bus->bridge);
2801
2802 return false;
2803}
2804EXPORT_SYMBOL_GPL(pci_dev_run_wake);
2805
2806/**
2807 * pci_dev_need_resume - Check if it is necessary to resume the device.
2808 * @pci_dev: Device to check.
2809 *
2810 * Return 'true' if the device is not runtime-suspended or it has to be
2811 * reconfigured due to wakeup settings difference between system and runtime
2812 * suspend, or the current power state of it is not suitable for the upcoming
2813 * (system-wide) transition.
2814 */
2815bool pci_dev_need_resume(struct pci_dev *pci_dev)
2816{
2817 struct device *dev = &pci_dev->dev;
2818 pci_power_t target_state;
2819
2820 if (!pm_runtime_suspended(dev) || platform_pci_need_resume(pci_dev))
2821 return true;
2822
2823 target_state = pci_target_state(pci_dev, device_may_wakeup(dev));
2824
2825 /*
2826 * If the earlier platform check has not triggered, D3cold is just power
2827 * removal on top of D3hot, so no need to resume the device in that
2828 * case.
2829 */
2830 return target_state != pci_dev->current_state &&
2831 target_state != PCI_D3cold &&
2832 pci_dev->current_state != PCI_D3hot;
2833}
2834
2835/**
2836 * pci_dev_adjust_pme - Adjust PME setting for a suspended device.
2837 * @pci_dev: Device to check.
2838 *
2839 * If the device is suspended and it is not configured for system wakeup,
2840 * disable PME for it to prevent it from waking up the system unnecessarily.
2841 *
2842 * Note that if the device's power state is D3cold and the platform check in
2843 * pci_dev_need_resume() has not triggered, the device's configuration need not
2844 * be changed.
2845 */
2846void pci_dev_adjust_pme(struct pci_dev *pci_dev)
2847{
2848 struct device *dev = &pci_dev->dev;
2849
2850 spin_lock_irq(&dev->power.lock);
2851
2852 if (pm_runtime_suspended(dev) && !device_may_wakeup(dev) &&
2853 pci_dev->current_state < PCI_D3cold)
2854 __pci_pme_active(pci_dev, false);
2855
2856 spin_unlock_irq(&dev->power.lock);
2857}
2858
2859/**
2860 * pci_dev_complete_resume - Finalize resume from system sleep for a device.
2861 * @pci_dev: Device to handle.
2862 *
2863 * If the device is runtime suspended and wakeup-capable, enable PME for it as
2864 * it might have been disabled during the prepare phase of system suspend if
2865 * the device was not configured for system wakeup.
2866 */
2867void pci_dev_complete_resume(struct pci_dev *pci_dev)
2868{
2869 struct device *dev = &pci_dev->dev;
2870
2871 if (!pci_dev_run_wake(pci_dev))
2872 return;
2873
2874 spin_lock_irq(&dev->power.lock);
2875
2876 if (pm_runtime_suspended(dev) && pci_dev->current_state < PCI_D3cold)
2877 __pci_pme_active(pci_dev, true);
2878
2879 spin_unlock_irq(&dev->power.lock);
2880}
2881
2882/**
2883 * pci_choose_state - Choose the power state of a PCI device.
2884 * @dev: Target PCI device.
2885 * @state: Target state for the whole system.
2886 *
2887 * Returns PCI power state suitable for @dev and @state.
2888 */
2889pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state)
2890{
2891 if (state.event == PM_EVENT_ON)
2892 return PCI_D0;
2893
2894 return pci_target_state(dev, false);
2895}
2896EXPORT_SYMBOL(pci_choose_state);
2897
2898void pci_config_pm_runtime_get(struct pci_dev *pdev)
2899{
2900 struct device *dev = &pdev->dev;
2901 struct device *parent = dev->parent;
2902
2903 if (parent)
2904 pm_runtime_get_sync(parent);
2905 pm_runtime_get_noresume(dev);
2906 /*
2907 * pdev->current_state is set to PCI_D3cold during suspending,
2908 * so wait until suspending completes
2909 */
2910 pm_runtime_barrier(dev);
2911 /*
2912 * Only need to resume devices in D3cold, because config
2913 * registers are still accessible for devices suspended but
2914 * not in D3cold.
2915 */
2916 if (pdev->current_state == PCI_D3cold)
2917 pm_runtime_resume(dev);
2918}
2919
2920void pci_config_pm_runtime_put(struct pci_dev *pdev)
2921{
2922 struct device *dev = &pdev->dev;
2923 struct device *parent = dev->parent;
2924
2925 pm_runtime_put(dev);
2926 if (parent)
2927 pm_runtime_put_sync(parent);
2928}
2929
2930static const struct dmi_system_id bridge_d3_blacklist[] = {
2931#ifdef CONFIG_X86
2932 {
2933 /*
2934 * Gigabyte X299 root port is not marked as hotplug capable
2935 * which allows Linux to power manage it. However, this
2936 * confuses the BIOS SMI handler so don't power manage root
2937 * ports on that system.
2938 */
2939 .ident = "X299 DESIGNARE EX-CF",
2940 .matches = {
2941 DMI_MATCH(DMI_BOARD_VENDOR, "Gigabyte Technology Co., Ltd."),
2942 DMI_MATCH(DMI_BOARD_NAME, "X299 DESIGNARE EX-CF"),
2943 },
2944 },
2945 {
2946 /*
2947 * Downstream device is not accessible after putting a root port
2948 * into D3cold and back into D0 on Elo i2.
2949 */
2950 .ident = "Elo i2",
2951 .matches = {
2952 DMI_MATCH(DMI_SYS_VENDOR, "Elo Touch Solutions"),
2953 DMI_MATCH(DMI_PRODUCT_NAME, "Elo i2"),
2954 DMI_MATCH(DMI_PRODUCT_VERSION, "RevB"),
2955 },
2956 },
2957#endif
2958 { }
2959};
2960
2961/**
2962 * pci_bridge_d3_possible - Is it possible to put the bridge into D3
2963 * @bridge: Bridge to check
2964 *
2965 * This function checks if it is possible to move the bridge to D3.
2966 * Currently we only allow D3 for recent enough PCIe ports and Thunderbolt.
2967 */
2968bool pci_bridge_d3_possible(struct pci_dev *bridge)
2969{
2970 if (!pci_is_pcie(bridge))
2971 return false;
2972
2973 switch (pci_pcie_type(bridge)) {
2974 case PCI_EXP_TYPE_ROOT_PORT:
2975 case PCI_EXP_TYPE_UPSTREAM:
2976 case PCI_EXP_TYPE_DOWNSTREAM:
2977 if (pci_bridge_d3_disable)
2978 return false;
2979
2980 /*
2981 * Hotplug ports handled by firmware in System Management Mode
2982 * may not be put into D3 by the OS (Thunderbolt on non-Macs).
2983 */
2984 if (bridge->is_hotplug_bridge && !pciehp_is_native(bridge))
2985 return false;
2986
2987 if (pci_bridge_d3_force)
2988 return true;
2989
2990 /* Even the oldest 2010 Thunderbolt controller supports D3. */
2991 if (bridge->is_thunderbolt)
2992 return true;
2993
2994 /* Platform might know better if the bridge supports D3 */
2995 if (platform_pci_bridge_d3(bridge))
2996 return true;
2997
2998 /*
2999 * Hotplug ports handled natively by the OS were not validated
3000 * by vendors for runtime D3 at least until 2018 because there
3001 * was no OS support.
3002 */
3003 if (bridge->is_hotplug_bridge)
3004 return false;
3005
3006 if (dmi_check_system(bridge_d3_blacklist))
3007 return false;
3008
3009 /*
3010 * It should be safe to put PCIe ports from 2015 or newer
3011 * to D3.
3012 */
3013 if (dmi_get_bios_year() >= 2015)
3014 return true;
3015 break;
3016 }
3017
3018 return false;
3019}
3020
3021static int pci_dev_check_d3cold(struct pci_dev *dev, void *data)
3022{
3023 bool *d3cold_ok = data;
3024
3025 if (/* The device needs to be allowed to go D3cold ... */
3026 dev->no_d3cold || !dev->d3cold_allowed ||
3027
3028 /* ... and if it is wakeup capable to do so from D3cold. */
3029 (device_may_wakeup(&dev->dev) &&
3030 !pci_pme_capable(dev, PCI_D3cold)) ||
3031
3032 /* If it is a bridge it must be allowed to go to D3. */
3033 !pci_power_manageable(dev))
3034
3035 *d3cold_ok = false;
3036
3037 return !*d3cold_ok;
3038}
3039
3040/*
3041 * pci_bridge_d3_update - Update bridge D3 capabilities
3042 * @dev: PCI device which is changed
3043 *
3044 * Update upstream bridge PM capabilities accordingly depending on if the
3045 * device PM configuration was changed or the device is being removed. The
3046 * change is also propagated upstream.
3047 */
3048void pci_bridge_d3_update(struct pci_dev *dev)
3049{
3050 bool remove = !device_is_registered(&dev->dev);
3051 struct pci_dev *bridge;
3052 bool d3cold_ok = true;
3053
3054 bridge = pci_upstream_bridge(dev);
3055 if (!bridge || !pci_bridge_d3_possible(bridge))
3056 return;
3057
3058 /*
3059 * If D3 is currently allowed for the bridge, removing one of its
3060 * children won't change that.
3061 */
3062 if (remove && bridge->bridge_d3)
3063 return;
3064
3065 /*
3066 * If D3 is currently allowed for the bridge and a child is added or
3067 * changed, disallowance of D3 can only be caused by that child, so
3068 * we only need to check that single device, not any of its siblings.
3069 *
3070 * If D3 is currently not allowed for the bridge, checking the device
3071 * first may allow us to skip checking its siblings.
3072 */
3073 if (!remove)
3074 pci_dev_check_d3cold(dev, &d3cold_ok);
3075
3076 /*
3077 * If D3 is currently not allowed for the bridge, this may be caused
3078 * either by the device being changed/removed or any of its siblings,
3079 * so we need to go through all children to find out if one of them
3080 * continues to block D3.
3081 */
3082 if (d3cold_ok && !bridge->bridge_d3)
3083 pci_walk_bus(bridge->subordinate, pci_dev_check_d3cold,
3084 &d3cold_ok);
3085
3086 if (bridge->bridge_d3 != d3cold_ok) {
3087 bridge->bridge_d3 = d3cold_ok;
3088 /* Propagate change to upstream bridges */
3089 pci_bridge_d3_update(bridge);
3090 }
3091}
3092
3093/**
3094 * pci_d3cold_enable - Enable D3cold for device
3095 * @dev: PCI device to handle
3096 *
3097 * This function can be used in drivers to enable D3cold from the device
3098 * they handle. It also updates upstream PCI bridge PM capabilities
3099 * accordingly.
3100 */
3101void pci_d3cold_enable(struct pci_dev *dev)
3102{
3103 if (dev->no_d3cold) {
3104 dev->no_d3cold = false;
3105 pci_bridge_d3_update(dev);
3106 }
3107}
3108EXPORT_SYMBOL_GPL(pci_d3cold_enable);
3109
3110/**
3111 * pci_d3cold_disable - Disable D3cold for device
3112 * @dev: PCI device to handle
3113 *
3114 * This function can be used in drivers to disable D3cold from the device
3115 * they handle. It also updates upstream PCI bridge PM capabilities
3116 * accordingly.
3117 */
3118void pci_d3cold_disable(struct pci_dev *dev)
3119{
3120 if (!dev->no_d3cold) {
3121 dev->no_d3cold = true;
3122 pci_bridge_d3_update(dev);
3123 }
3124}
3125EXPORT_SYMBOL_GPL(pci_d3cold_disable);
3126
3127/**
3128 * pci_pm_init - Initialize PM functions of given PCI device
3129 * @dev: PCI device to handle.
3130 */
3131void pci_pm_init(struct pci_dev *dev)
3132{
3133 int pm;
3134 u16 status;
3135 u16 pmc;
3136
3137 pm_runtime_forbid(&dev->dev);
3138 pm_runtime_set_active(&dev->dev);
3139 pm_runtime_enable(&dev->dev);
3140 device_enable_async_suspend(&dev->dev);
3141 dev->wakeup_prepared = false;
3142
3143 dev->pm_cap = 0;
3144 dev->pme_support = 0;
3145
3146 /* find PCI PM capability in list */
3147 pm = pci_find_capability(dev, PCI_CAP_ID_PM);
3148 if (!pm)
3149 return;
3150 /* Check device's ability to generate PME# */
3151 pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
3152
3153 if ((pmc & PCI_PM_CAP_VER_MASK) > 3) {
3154 pci_err(dev, "unsupported PM cap regs version (%u)\n",
3155 pmc & PCI_PM_CAP_VER_MASK);
3156 return;
3157 }
3158
3159 dev->pm_cap = pm;
3160 dev->d3hot_delay = PCI_PM_D3HOT_WAIT;
3161 dev->d3cold_delay = PCI_PM_D3COLD_WAIT;
3162 dev->bridge_d3 = pci_bridge_d3_possible(dev);
3163 dev->d3cold_allowed = true;
3164
3165 dev->d1_support = false;
3166 dev->d2_support = false;
3167 if (!pci_no_d1d2(dev)) {
3168 if (pmc & PCI_PM_CAP_D1)
3169 dev->d1_support = true;
3170 if (pmc & PCI_PM_CAP_D2)
3171 dev->d2_support = true;
3172
3173 if (dev->d1_support || dev->d2_support)
3174 pci_info(dev, "supports%s%s\n",
3175 dev->d1_support ? " D1" : "",
3176 dev->d2_support ? " D2" : "");
3177 }
3178
3179 pmc &= PCI_PM_CAP_PME_MASK;
3180 if (pmc) {
3181 pci_info(dev, "PME# supported from%s%s%s%s%s\n",
3182 (pmc & PCI_PM_CAP_PME_D0) ? " D0" : "",
3183 (pmc & PCI_PM_CAP_PME_D1) ? " D1" : "",
3184 (pmc & PCI_PM_CAP_PME_D2) ? " D2" : "",
3185 (pmc & PCI_PM_CAP_PME_D3hot) ? " D3hot" : "",
3186 (pmc & PCI_PM_CAP_PME_D3cold) ? " D3cold" : "");
3187 dev->pme_support = pmc >> PCI_PM_CAP_PME_SHIFT;
3188 dev->pme_poll = true;
3189 /*
3190 * Make device's PM flags reflect the wake-up capability, but
3191 * let the user space enable it to wake up the system as needed.
3192 */
3193 device_set_wakeup_capable(&dev->dev, true);
3194 /* Disable the PME# generation functionality */
3195 pci_pme_active(dev, false);
3196 }
3197
3198 pci_read_config_word(dev, PCI_STATUS, &status);
3199 if (status & PCI_STATUS_IMM_READY)
3200 dev->imm_ready = 1;
3201}
3202
3203static unsigned long pci_ea_flags(struct pci_dev *dev, u8 prop)
3204{
3205 unsigned long flags = IORESOURCE_PCI_FIXED | IORESOURCE_PCI_EA_BEI;
3206
3207 switch (prop) {
3208 case PCI_EA_P_MEM:
3209 case PCI_EA_P_VF_MEM:
3210 flags |= IORESOURCE_MEM;
3211 break;
3212 case PCI_EA_P_MEM_PREFETCH:
3213 case PCI_EA_P_VF_MEM_PREFETCH:
3214 flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH;
3215 break;
3216 case PCI_EA_P_IO:
3217 flags |= IORESOURCE_IO;
3218 break;
3219 default:
3220 return 0;
3221 }
3222
3223 return flags;
3224}
3225
3226static struct resource *pci_ea_get_resource(struct pci_dev *dev, u8 bei,
3227 u8 prop)
3228{
3229 if (bei <= PCI_EA_BEI_BAR5 && prop <= PCI_EA_P_IO)
3230 return &dev->resource[bei];
3231#ifdef CONFIG_PCI_IOV
3232 else if (bei >= PCI_EA_BEI_VF_BAR0 && bei <= PCI_EA_BEI_VF_BAR5 &&
3233 (prop == PCI_EA_P_VF_MEM || prop == PCI_EA_P_VF_MEM_PREFETCH))
3234 return &dev->resource[PCI_IOV_RESOURCES +
3235 bei - PCI_EA_BEI_VF_BAR0];
3236#endif
3237 else if (bei == PCI_EA_BEI_ROM)
3238 return &dev->resource[PCI_ROM_RESOURCE];
3239 else
3240 return NULL;
3241}
3242
3243/* Read an Enhanced Allocation (EA) entry */
3244static int pci_ea_read(struct pci_dev *dev, int offset)
3245{
3246 struct resource *res;
3247 int ent_size, ent_offset = offset;
3248 resource_size_t start, end;
3249 unsigned long flags;
3250 u32 dw0, bei, base, max_offset;
3251 u8 prop;
3252 bool support_64 = (sizeof(resource_size_t) >= 8);
3253
3254 pci_read_config_dword(dev, ent_offset, &dw0);
3255 ent_offset += 4;
3256
3257 /* Entry size field indicates DWORDs after 1st */
3258 ent_size = ((dw0 & PCI_EA_ES) + 1) << 2;
3259
3260 if (!(dw0 & PCI_EA_ENABLE)) /* Entry not enabled */
3261 goto out;
3262
3263 bei = (dw0 & PCI_EA_BEI) >> 4;
3264 prop = (dw0 & PCI_EA_PP) >> 8;
3265
3266 /*
3267 * If the Property is in the reserved range, try the Secondary
3268 * Property instead.
3269 */
3270 if (prop > PCI_EA_P_BRIDGE_IO && prop < PCI_EA_P_MEM_RESERVED)
3271 prop = (dw0 & PCI_EA_SP) >> 16;
3272 if (prop > PCI_EA_P_BRIDGE_IO)
3273 goto out;
3274
3275 res = pci_ea_get_resource(dev, bei, prop);
3276 if (!res) {
3277 pci_err(dev, "Unsupported EA entry BEI: %u\n", bei);
3278 goto out;
3279 }
3280
3281 flags = pci_ea_flags(dev, prop);
3282 if (!flags) {
3283 pci_err(dev, "Unsupported EA properties: %#x\n", prop);
3284 goto out;
3285 }
3286
3287 /* Read Base */
3288 pci_read_config_dword(dev, ent_offset, &base);
3289 start = (base & PCI_EA_FIELD_MASK);
3290 ent_offset += 4;
3291
3292 /* Read MaxOffset */
3293 pci_read_config_dword(dev, ent_offset, &max_offset);
3294 ent_offset += 4;
3295
3296 /* Read Base MSBs (if 64-bit entry) */
3297 if (base & PCI_EA_IS_64) {
3298 u32 base_upper;
3299
3300 pci_read_config_dword(dev, ent_offset, &base_upper);
3301 ent_offset += 4;
3302
3303 flags |= IORESOURCE_MEM_64;
3304
3305 /* entry starts above 32-bit boundary, can't use */
3306 if (!support_64 && base_upper)
3307 goto out;
3308
3309 if (support_64)
3310 start |= ((u64)base_upper << 32);
3311 }
3312
3313 end = start + (max_offset | 0x03);
3314
3315 /* Read MaxOffset MSBs (if 64-bit entry) */
3316 if (max_offset & PCI_EA_IS_64) {
3317 u32 max_offset_upper;
3318
3319 pci_read_config_dword(dev, ent_offset, &max_offset_upper);
3320 ent_offset += 4;
3321
3322 flags |= IORESOURCE_MEM_64;
3323
3324 /* entry too big, can't use */
3325 if (!support_64 && max_offset_upper)
3326 goto out;
3327
3328 if (support_64)
3329 end += ((u64)max_offset_upper << 32);
3330 }
3331
3332 if (end < start) {
3333 pci_err(dev, "EA Entry crosses address boundary\n");
3334 goto out;
3335 }
3336
3337 if (ent_size != ent_offset - offset) {
3338 pci_err(dev, "EA Entry Size (%d) does not match length read (%d)\n",
3339 ent_size, ent_offset - offset);
3340 goto out;
3341 }
3342
3343 res->name = pci_name(dev);
3344 res->start = start;
3345 res->end = end;
3346 res->flags = flags;
3347
3348 if (bei <= PCI_EA_BEI_BAR5)
3349 pci_info(dev, "BAR %d: %pR (from Enhanced Allocation, properties %#02x)\n",
3350 bei, res, prop);
3351 else if (bei == PCI_EA_BEI_ROM)
3352 pci_info(dev, "ROM: %pR (from Enhanced Allocation, properties %#02x)\n",
3353 res, prop);
3354 else if (bei >= PCI_EA_BEI_VF_BAR0 && bei <= PCI_EA_BEI_VF_BAR5)
3355 pci_info(dev, "VF BAR %d: %pR (from Enhanced Allocation, properties %#02x)\n",
3356 bei - PCI_EA_BEI_VF_BAR0, res, prop);
3357 else
3358 pci_info(dev, "BEI %d res: %pR (from Enhanced Allocation, properties %#02x)\n",
3359 bei, res, prop);
3360
3361out:
3362 return offset + ent_size;
3363}
3364
3365/* Enhanced Allocation Initialization */
3366void pci_ea_init(struct pci_dev *dev)
3367{
3368 int ea;
3369 u8 num_ent;
3370 int offset;
3371 int i;
3372
3373 /* find PCI EA capability in list */
3374 ea = pci_find_capability(dev, PCI_CAP_ID_EA);
3375 if (!ea)
3376 return;
3377
3378 /* determine the number of entries */
3379 pci_bus_read_config_byte(dev->bus, dev->devfn, ea + PCI_EA_NUM_ENT,
3380 &num_ent);
3381 num_ent &= PCI_EA_NUM_ENT_MASK;
3382
3383 offset = ea + PCI_EA_FIRST_ENT;
3384
3385 /* Skip DWORD 2 for type 1 functions */
3386 if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)
3387 offset += 4;
3388
3389 /* parse each EA entry */
3390 for (i = 0; i < num_ent; ++i)
3391 offset = pci_ea_read(dev, offset);
3392}
3393
3394static void pci_add_saved_cap(struct pci_dev *pci_dev,
3395 struct pci_cap_saved_state *new_cap)
3396{
3397 hlist_add_head(&new_cap->next, &pci_dev->saved_cap_space);
3398}
3399
3400/**
3401 * _pci_add_cap_save_buffer - allocate buffer for saving given
3402 * capability registers
3403 * @dev: the PCI device
3404 * @cap: the capability to allocate the buffer for
3405 * @extended: Standard or Extended capability ID
3406 * @size: requested size of the buffer
3407 */
3408static int _pci_add_cap_save_buffer(struct pci_dev *dev, u16 cap,
3409 bool extended, unsigned int size)
3410{
3411 int pos;
3412 struct pci_cap_saved_state *save_state;
3413
3414 if (extended)
3415 pos = pci_find_ext_capability(dev, cap);
3416 else
3417 pos = pci_find_capability(dev, cap);
3418
3419 if (!pos)
3420 return 0;
3421
3422 save_state = kzalloc(sizeof(*save_state) + size, GFP_KERNEL);
3423 if (!save_state)
3424 return -ENOMEM;
3425
3426 save_state->cap.cap_nr = cap;
3427 save_state->cap.cap_extended = extended;
3428 save_state->cap.size = size;
3429 pci_add_saved_cap(dev, save_state);
3430
3431 return 0;
3432}
3433
3434int pci_add_cap_save_buffer(struct pci_dev *dev, char cap, unsigned int size)
3435{
3436 return _pci_add_cap_save_buffer(dev, cap, false, size);
3437}
3438
3439int pci_add_ext_cap_save_buffer(struct pci_dev *dev, u16 cap, unsigned int size)
3440{
3441 return _pci_add_cap_save_buffer(dev, cap, true, size);
3442}
3443
3444/**
3445 * pci_allocate_cap_save_buffers - allocate buffers for saving capabilities
3446 * @dev: the PCI device
3447 */
3448void pci_allocate_cap_save_buffers(struct pci_dev *dev)
3449{
3450 int error;
3451
3452 error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_EXP,
3453 PCI_EXP_SAVE_REGS * sizeof(u16));
3454 if (error)
3455 pci_err(dev, "unable to preallocate PCI Express save buffer\n");
3456
3457 error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_PCIX, sizeof(u16));
3458 if (error)
3459 pci_err(dev, "unable to preallocate PCI-X save buffer\n");
3460
3461 error = pci_add_ext_cap_save_buffer(dev, PCI_EXT_CAP_ID_LTR,
3462 2 * sizeof(u16));
3463 if (error)
3464 pci_err(dev, "unable to allocate suspend buffer for LTR\n");
3465
3466 pci_allocate_vc_save_buffers(dev);
3467}
3468
3469void pci_free_cap_save_buffers(struct pci_dev *dev)
3470{
3471 struct pci_cap_saved_state *tmp;
3472 struct hlist_node *n;
3473
3474 hlist_for_each_entry_safe(tmp, n, &dev->saved_cap_space, next)
3475 kfree(tmp);
3476}
3477
3478/**
3479 * pci_configure_ari - enable or disable ARI forwarding
3480 * @dev: the PCI device
3481 *
3482 * If @dev and its upstream bridge both support ARI, enable ARI in the
3483 * bridge. Otherwise, disable ARI in the bridge.
3484 */
3485void pci_configure_ari(struct pci_dev *dev)
3486{
3487 u32 cap;
3488 struct pci_dev *bridge;
3489
3490 if (pcie_ari_disabled || !pci_is_pcie(dev) || dev->devfn)
3491 return;
3492
3493 bridge = dev->bus->self;
3494 if (!bridge)
3495 return;
3496
3497 pcie_capability_read_dword(bridge, PCI_EXP_DEVCAP2, &cap);
3498 if (!(cap & PCI_EXP_DEVCAP2_ARI))
3499 return;
3500
3501 if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI)) {
3502 pcie_capability_set_word(bridge, PCI_EXP_DEVCTL2,
3503 PCI_EXP_DEVCTL2_ARI);
3504 bridge->ari_enabled = 1;
3505 } else {
3506 pcie_capability_clear_word(bridge, PCI_EXP_DEVCTL2,
3507 PCI_EXP_DEVCTL2_ARI);
3508 bridge->ari_enabled = 0;
3509 }
3510}
3511
3512static bool pci_acs_flags_enabled(struct pci_dev *pdev, u16 acs_flags)
3513{
3514 int pos;
3515 u16 cap, ctrl;
3516
3517 pos = pdev->acs_cap;
3518 if (!pos)
3519 return false;
3520
3521 /*
3522 * Except for egress control, capabilities are either required
3523 * or only required if controllable. Features missing from the
3524 * capability field can therefore be assumed as hard-wired enabled.
3525 */
3526 pci_read_config_word(pdev, pos + PCI_ACS_CAP, &cap);
3527 acs_flags &= (cap | PCI_ACS_EC);
3528
3529 pci_read_config_word(pdev, pos + PCI_ACS_CTRL, &ctrl);
3530 return (ctrl & acs_flags) == acs_flags;
3531}
3532
3533/**
3534 * pci_acs_enabled - test ACS against required flags for a given device
3535 * @pdev: device to test
3536 * @acs_flags: required PCI ACS flags
3537 *
3538 * Return true if the device supports the provided flags. Automatically
3539 * filters out flags that are not implemented on multifunction devices.
3540 *
3541 * Note that this interface checks the effective ACS capabilities of the
3542 * device rather than the actual capabilities. For instance, most single
3543 * function endpoints are not required to support ACS because they have no
3544 * opportunity for peer-to-peer access. We therefore return 'true'
3545 * regardless of whether the device exposes an ACS capability. This makes
3546 * it much easier for callers of this function to ignore the actual type
3547 * or topology of the device when testing ACS support.
3548 */
3549bool pci_acs_enabled(struct pci_dev *pdev, u16 acs_flags)
3550{
3551 int ret;
3552
3553 ret = pci_dev_specific_acs_enabled(pdev, acs_flags);
3554 if (ret >= 0)
3555 return ret > 0;
3556
3557 /*
3558 * Conventional PCI and PCI-X devices never support ACS, either
3559 * effectively or actually. The shared bus topology implies that
3560 * any device on the bus can receive or snoop DMA.
3561 */
3562 if (!pci_is_pcie(pdev))
3563 return false;
3564
3565 switch (pci_pcie_type(pdev)) {
3566 /*
3567 * PCI/X-to-PCIe bridges are not specifically mentioned by the spec,
3568 * but since their primary interface is PCI/X, we conservatively
3569 * handle them as we would a non-PCIe device.
3570 */
3571 case PCI_EXP_TYPE_PCIE_BRIDGE:
3572 /*
3573 * PCIe 3.0, 6.12.1 excludes ACS on these devices. "ACS is never
3574 * applicable... must never implement an ACS Extended Capability...".
3575 * This seems arbitrary, but we take a conservative interpretation
3576 * of this statement.
3577 */
3578 case PCI_EXP_TYPE_PCI_BRIDGE:
3579 case PCI_EXP_TYPE_RC_EC:
3580 return false;
3581 /*
3582 * PCIe 3.0, 6.12.1.1 specifies that downstream and root ports should
3583 * implement ACS in order to indicate their peer-to-peer capabilities,
3584 * regardless of whether they are single- or multi-function devices.
3585 */
3586 case PCI_EXP_TYPE_DOWNSTREAM:
3587 case PCI_EXP_TYPE_ROOT_PORT:
3588 return pci_acs_flags_enabled(pdev, acs_flags);
3589 /*
3590 * PCIe 3.0, 6.12.1.2 specifies ACS capabilities that should be
3591 * implemented by the remaining PCIe types to indicate peer-to-peer
3592 * capabilities, but only when they are part of a multifunction
3593 * device. The footnote for section 6.12 indicates the specific
3594 * PCIe types included here.
3595 */
3596 case PCI_EXP_TYPE_ENDPOINT:
3597 case PCI_EXP_TYPE_UPSTREAM:
3598 case PCI_EXP_TYPE_LEG_END:
3599 case PCI_EXP_TYPE_RC_END:
3600 if (!pdev->multifunction)
3601 break;
3602
3603 return pci_acs_flags_enabled(pdev, acs_flags);
3604 }
3605
3606 /*
3607 * PCIe 3.0, 6.12.1.3 specifies no ACS capabilities are applicable
3608 * to single function devices with the exception of downstream ports.
3609 */
3610 return true;
3611}
3612
3613/**
3614 * pci_acs_path_enabled - test ACS flags from start to end in a hierarchy
3615 * @start: starting downstream device
3616 * @end: ending upstream device or NULL to search to the root bus
3617 * @acs_flags: required flags
3618 *
3619 * Walk up a device tree from start to end testing PCI ACS support. If
3620 * any step along the way does not support the required flags, return false.
3621 */
3622bool pci_acs_path_enabled(struct pci_dev *start,
3623 struct pci_dev *end, u16 acs_flags)
3624{
3625 struct pci_dev *pdev, *parent = start;
3626
3627 do {
3628 pdev = parent;
3629
3630 if (!pci_acs_enabled(pdev, acs_flags))
3631 return false;
3632
3633 if (pci_is_root_bus(pdev->bus))
3634 return (end == NULL);
3635
3636 parent = pdev->bus->self;
3637 } while (pdev != end);
3638
3639 return true;
3640}
3641
3642/**
3643 * pci_acs_init - Initialize ACS if hardware supports it
3644 * @dev: the PCI device
3645 */
3646void pci_acs_init(struct pci_dev *dev)
3647{
3648 dev->acs_cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS);
3649
3650 /*
3651 * Attempt to enable ACS regardless of capability because some Root
3652 * Ports (e.g. those quirked with *_intel_pch_acs_*) do not have
3653 * the standard ACS capability but still support ACS via those
3654 * quirks.
3655 */
3656 pci_enable_acs(dev);
3657}
3658
3659/**
3660 * pci_rebar_find_pos - find position of resize ctrl reg for BAR
3661 * @pdev: PCI device
3662 * @bar: BAR to find
3663 *
3664 * Helper to find the position of the ctrl register for a BAR.
3665 * Returns -ENOTSUPP if resizable BARs are not supported at all.
3666 * Returns -ENOENT if no ctrl register for the BAR could be found.
3667 */
3668static int pci_rebar_find_pos(struct pci_dev *pdev, int bar)
3669{
3670 unsigned int pos, nbars, i;
3671 u32 ctrl;
3672
3673 pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR);
3674 if (!pos)
3675 return -ENOTSUPP;
3676
3677 pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
3678 nbars = (ctrl & PCI_REBAR_CTRL_NBAR_MASK) >>
3679 PCI_REBAR_CTRL_NBAR_SHIFT;
3680
3681 for (i = 0; i < nbars; i++, pos += 8) {
3682 int bar_idx;
3683
3684 pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
3685 bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX;
3686 if (bar_idx == bar)
3687 return pos;
3688 }
3689
3690 return -ENOENT;
3691}
3692
3693/**
3694 * pci_rebar_get_possible_sizes - get possible sizes for BAR
3695 * @pdev: PCI device
3696 * @bar: BAR to query
3697 *
3698 * Get the possible sizes of a resizable BAR as bitmask defined in the spec
3699 * (bit 0=1MB, bit 19=512GB). Returns 0 if BAR isn't resizable.
3700 */
3701u32 pci_rebar_get_possible_sizes(struct pci_dev *pdev, int bar)
3702{
3703 int pos;
3704 u32 cap;
3705
3706 pos = pci_rebar_find_pos(pdev, bar);
3707 if (pos < 0)
3708 return 0;
3709
3710 pci_read_config_dword(pdev, pos + PCI_REBAR_CAP, &cap);
3711 cap &= PCI_REBAR_CAP_SIZES;
3712
3713 /* Sapphire RX 5600 XT Pulse has an invalid cap dword for BAR 0 */
3714 if (pdev->vendor == PCI_VENDOR_ID_ATI && pdev->device == 0x731f &&
3715 bar == 0 && cap == 0x7000)
3716 cap = 0x3f000;
3717
3718 return cap >> 4;
3719}
3720EXPORT_SYMBOL(pci_rebar_get_possible_sizes);
3721
3722/**
3723 * pci_rebar_get_current_size - get the current size of a BAR
3724 * @pdev: PCI device
3725 * @bar: BAR to set size to
3726 *
3727 * Read the size of a BAR from the resizable BAR config.
3728 * Returns size if found or negative error code.
3729 */
3730int pci_rebar_get_current_size(struct pci_dev *pdev, int bar)
3731{
3732 int pos;
3733 u32 ctrl;
3734
3735 pos = pci_rebar_find_pos(pdev, bar);
3736 if (pos < 0)
3737 return pos;
3738
3739 pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
3740 return (ctrl & PCI_REBAR_CTRL_BAR_SIZE) >> PCI_REBAR_CTRL_BAR_SHIFT;
3741}
3742
3743/**
3744 * pci_rebar_set_size - set a new size for a BAR
3745 * @pdev: PCI device
3746 * @bar: BAR to set size to
3747 * @size: new size as defined in the spec (0=1MB, 19=512GB)
3748 *
3749 * Set the new size of a BAR as defined in the spec.
3750 * Returns zero if resizing was successful, error code otherwise.
3751 */
3752int pci_rebar_set_size(struct pci_dev *pdev, int bar, int size)
3753{
3754 int pos;
3755 u32 ctrl;
3756
3757 pos = pci_rebar_find_pos(pdev, bar);
3758 if (pos < 0)
3759 return pos;
3760
3761 pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
3762 ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE;
3763 ctrl |= size << PCI_REBAR_CTRL_BAR_SHIFT;
3764 pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl);
3765 return 0;
3766}
3767
3768/**
3769 * pci_enable_atomic_ops_to_root - enable AtomicOp requests to root port
3770 * @dev: the PCI device
3771 * @cap_mask: mask of desired AtomicOp sizes, including one or more of:
3772 * PCI_EXP_DEVCAP2_ATOMIC_COMP32
3773 * PCI_EXP_DEVCAP2_ATOMIC_COMP64
3774 * PCI_EXP_DEVCAP2_ATOMIC_COMP128
3775 *
3776 * Return 0 if all upstream bridges support AtomicOp routing, egress
3777 * blocking is disabled on all upstream ports, and the root port supports
3778 * the requested completion capabilities (32-bit, 64-bit and/or 128-bit
3779 * AtomicOp completion), or negative otherwise.
3780 */
3781int pci_enable_atomic_ops_to_root(struct pci_dev *dev, u32 cap_mask)
3782{
3783 struct pci_bus *bus = dev->bus;
3784 struct pci_dev *bridge;
3785 u32 cap, ctl2;
3786
3787 /*
3788 * Per PCIe r5.0, sec 9.3.5.10, the AtomicOp Requester Enable bit
3789 * in Device Control 2 is reserved in VFs and the PF value applies
3790 * to all associated VFs.
3791 */
3792 if (dev->is_virtfn)
3793 return -EINVAL;
3794
3795 if (!pci_is_pcie(dev))
3796 return -EINVAL;
3797
3798 /*
3799 * Per PCIe r4.0, sec 6.15, endpoints and root ports may be
3800 * AtomicOp requesters. For now, we only support endpoints as
3801 * requesters and root ports as completers. No endpoints as
3802 * completers, and no peer-to-peer.
3803 */
3804
3805 switch (pci_pcie_type(dev)) {
3806 case PCI_EXP_TYPE_ENDPOINT:
3807 case PCI_EXP_TYPE_LEG_END:
3808 case PCI_EXP_TYPE_RC_END:
3809 break;
3810 default:
3811 return -EINVAL;
3812 }
3813
3814 while (bus->parent) {
3815 bridge = bus->self;
3816
3817 pcie_capability_read_dword(bridge, PCI_EXP_DEVCAP2, &cap);
3818
3819 switch (pci_pcie_type(bridge)) {
3820 /* Ensure switch ports support AtomicOp routing */
3821 case PCI_EXP_TYPE_UPSTREAM:
3822 case PCI_EXP_TYPE_DOWNSTREAM:
3823 if (!(cap & PCI_EXP_DEVCAP2_ATOMIC_ROUTE))
3824 return -EINVAL;
3825 break;
3826
3827 /* Ensure root port supports all the sizes we care about */
3828 case PCI_EXP_TYPE_ROOT_PORT:
3829 if ((cap & cap_mask) != cap_mask)
3830 return -EINVAL;
3831 break;
3832 }
3833
3834 /* Ensure upstream ports don't block AtomicOps on egress */
3835 if (pci_pcie_type(bridge) == PCI_EXP_TYPE_UPSTREAM) {
3836 pcie_capability_read_dword(bridge, PCI_EXP_DEVCTL2,
3837 &ctl2);
3838 if (ctl2 & PCI_EXP_DEVCTL2_ATOMIC_EGRESS_BLOCK)
3839 return -EINVAL;
3840 }
3841
3842 bus = bus->parent;
3843 }
3844
3845 pcie_capability_set_word(dev, PCI_EXP_DEVCTL2,
3846 PCI_EXP_DEVCTL2_ATOMIC_REQ);
3847 return 0;
3848}
3849EXPORT_SYMBOL(pci_enable_atomic_ops_to_root);
3850
3851/**
3852 * pci_swizzle_interrupt_pin - swizzle INTx for device behind bridge
3853 * @dev: the PCI device
3854 * @pin: the INTx pin (1=INTA, 2=INTB, 3=INTC, 4=INTD)
3855 *
3856 * Perform INTx swizzling for a device behind one level of bridge. This is
3857 * required by section 9.1 of the PCI-to-PCI bridge specification for devices
3858 * behind bridges on add-in cards. For devices with ARI enabled, the slot
3859 * number is always 0 (see the Implementation Note in section 2.2.8.1 of
3860 * the PCI Express Base Specification, Revision 2.1)
3861 */
3862u8 pci_swizzle_interrupt_pin(const struct pci_dev *dev, u8 pin)
3863{
3864 int slot;
3865
3866 if (pci_ari_enabled(dev->bus))
3867 slot = 0;
3868 else
3869 slot = PCI_SLOT(dev->devfn);
3870
3871 return (((pin - 1) + slot) % 4) + 1;
3872}
3873
3874int pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge)
3875{
3876 u8 pin;
3877
3878 pin = dev->pin;
3879 if (!pin)
3880 return -1;
3881
3882 while (!pci_is_root_bus(dev->bus)) {
3883 pin = pci_swizzle_interrupt_pin(dev, pin);
3884 dev = dev->bus->self;
3885 }
3886 *bridge = dev;
3887 return pin;
3888}
3889
3890/**
3891 * pci_common_swizzle - swizzle INTx all the way to root bridge
3892 * @dev: the PCI device
3893 * @pinp: pointer to the INTx pin value (1=INTA, 2=INTB, 3=INTD, 4=INTD)
3894 *
3895 * Perform INTx swizzling for a device. This traverses through all PCI-to-PCI
3896 * bridges all the way up to a PCI root bus.
3897 */
3898u8 pci_common_swizzle(struct pci_dev *dev, u8 *pinp)
3899{
3900 u8 pin = *pinp;
3901
3902 while (!pci_is_root_bus(dev->bus)) {
3903 pin = pci_swizzle_interrupt_pin(dev, pin);
3904 dev = dev->bus->self;
3905 }
3906 *pinp = pin;
3907 return PCI_SLOT(dev->devfn);
3908}
3909EXPORT_SYMBOL_GPL(pci_common_swizzle);
3910
3911/**
3912 * pci_release_region - Release a PCI bar
3913 * @pdev: PCI device whose resources were previously reserved by
3914 * pci_request_region()
3915 * @bar: BAR to release
3916 *
3917 * Releases the PCI I/O and memory resources previously reserved by a
3918 * successful call to pci_request_region(). Call this function only
3919 * after all use of the PCI regions has ceased.
3920 */
3921void pci_release_region(struct pci_dev *pdev, int bar)
3922{
3923 struct pci_devres *dr;
3924
3925 if (pci_resource_len(pdev, bar) == 0)
3926 return;
3927 if (pci_resource_flags(pdev, bar) & IORESOURCE_IO)
3928 release_region(pci_resource_start(pdev, bar),
3929 pci_resource_len(pdev, bar));
3930 else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM)
3931 release_mem_region(pci_resource_start(pdev, bar),
3932 pci_resource_len(pdev, bar));
3933
3934 dr = find_pci_dr(pdev);
3935 if (dr)
3936 dr->region_mask &= ~(1 << bar);
3937}
3938EXPORT_SYMBOL(pci_release_region);
3939
3940/**
3941 * __pci_request_region - Reserved PCI I/O and memory resource
3942 * @pdev: PCI device whose resources are to be reserved
3943 * @bar: BAR to be reserved
3944 * @res_name: Name to be associated with resource.
3945 * @exclusive: whether the region access is exclusive or not
3946 *
3947 * Mark the PCI region associated with PCI device @pdev BAR @bar as
3948 * being reserved by owner @res_name. Do not access any
3949 * address inside the PCI regions unless this call returns
3950 * successfully.
3951 *
3952 * If @exclusive is set, then the region is marked so that userspace
3953 * is explicitly not allowed to map the resource via /dev/mem or
3954 * sysfs MMIO access.
3955 *
3956 * Returns 0 on success, or %EBUSY on error. A warning
3957 * message is also printed on failure.
3958 */
3959static int __pci_request_region(struct pci_dev *pdev, int bar,
3960 const char *res_name, int exclusive)
3961{
3962 struct pci_devres *dr;
3963
3964 if (pci_resource_len(pdev, bar) == 0)
3965 return 0;
3966
3967 if (pci_resource_flags(pdev, bar) & IORESOURCE_IO) {
3968 if (!request_region(pci_resource_start(pdev, bar),
3969 pci_resource_len(pdev, bar), res_name))
3970 goto err_out;
3971 } else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM) {
3972 if (!__request_mem_region(pci_resource_start(pdev, bar),
3973 pci_resource_len(pdev, bar), res_name,
3974 exclusive))
3975 goto err_out;
3976 }
3977
3978 dr = find_pci_dr(pdev);
3979 if (dr)
3980 dr->region_mask |= 1 << bar;
3981
3982 return 0;
3983
3984err_out:
3985 pci_warn(pdev, "BAR %d: can't reserve %pR\n", bar,
3986 &pdev->resource[bar]);
3987 return -EBUSY;
3988}
3989
3990/**
3991 * pci_request_region - Reserve PCI I/O and memory resource
3992 * @pdev: PCI device whose resources are to be reserved
3993 * @bar: BAR to be reserved
3994 * @res_name: Name to be associated with resource
3995 *
3996 * Mark the PCI region associated with PCI device @pdev BAR @bar as
3997 * being reserved by owner @res_name. Do not access any
3998 * address inside the PCI regions unless this call returns
3999 * successfully.
4000 *
4001 * Returns 0 on success, or %EBUSY on error. A warning
4002 * message is also printed on failure.
4003 */
4004int pci_request_region(struct pci_dev *pdev, int bar, const char *res_name)
4005{
4006 return __pci_request_region(pdev, bar, res_name, 0);
4007}
4008EXPORT_SYMBOL(pci_request_region);
4009
4010/**
4011 * pci_release_selected_regions - Release selected PCI I/O and memory resources
4012 * @pdev: PCI device whose resources were previously reserved
4013 * @bars: Bitmask of BARs to be released
4014 *
4015 * Release selected PCI I/O and memory resources previously reserved.
4016 * Call this function only after all use of the PCI regions has ceased.
4017 */
4018void pci_release_selected_regions(struct pci_dev *pdev, int bars)
4019{
4020 int i;
4021
4022 for (i = 0; i < PCI_STD_NUM_BARS; i++)
4023 if (bars & (1 << i))
4024 pci_release_region(pdev, i);
4025}
4026EXPORT_SYMBOL(pci_release_selected_regions);
4027
4028static int __pci_request_selected_regions(struct pci_dev *pdev, int bars,
4029 const char *res_name, int excl)
4030{
4031 int i;
4032
4033 for (i = 0; i < PCI_STD_NUM_BARS; i++)
4034 if (bars & (1 << i))
4035 if (__pci_request_region(pdev, i, res_name, excl))
4036 goto err_out;
4037 return 0;
4038
4039err_out:
4040 while (--i >= 0)
4041 if (bars & (1 << i))
4042 pci_release_region(pdev, i);
4043
4044 return -EBUSY;
4045}
4046
4047
4048/**
4049 * pci_request_selected_regions - Reserve selected PCI I/O and memory resources
4050 * @pdev: PCI device whose resources are to be reserved
4051 * @bars: Bitmask of BARs to be requested
4052 * @res_name: Name to be associated with resource
4053 */
4054int pci_request_selected_regions(struct pci_dev *pdev, int bars,
4055 const char *res_name)
4056{
4057 return __pci_request_selected_regions(pdev, bars, res_name, 0);
4058}
4059EXPORT_SYMBOL(pci_request_selected_regions);
4060
4061int pci_request_selected_regions_exclusive(struct pci_dev *pdev, int bars,
4062 const char *res_name)
4063{
4064 return __pci_request_selected_regions(pdev, bars, res_name,
4065 IORESOURCE_EXCLUSIVE);
4066}
4067EXPORT_SYMBOL(pci_request_selected_regions_exclusive);
4068
4069/**
4070 * pci_release_regions - Release reserved PCI I/O and memory resources
4071 * @pdev: PCI device whose resources were previously reserved by
4072 * pci_request_regions()
4073 *
4074 * Releases all PCI I/O and memory resources previously reserved by a
4075 * successful call to pci_request_regions(). Call this function only
4076 * after all use of the PCI regions has ceased.
4077 */
4078
4079void pci_release_regions(struct pci_dev *pdev)
4080{
4081 pci_release_selected_regions(pdev, (1 << PCI_STD_NUM_BARS) - 1);
4082}
4083EXPORT_SYMBOL(pci_release_regions);
4084
4085/**
4086 * pci_request_regions - Reserve PCI I/O and memory resources
4087 * @pdev: PCI device whose resources are to be reserved
4088 * @res_name: Name to be associated with resource.
4089 *
4090 * Mark all PCI regions associated with PCI device @pdev as
4091 * being reserved by owner @res_name. Do not access any
4092 * address inside the PCI regions unless this call returns
4093 * successfully.
4094 *
4095 * Returns 0 on success, or %EBUSY on error. A warning
4096 * message is also printed on failure.
4097 */
4098int pci_request_regions(struct pci_dev *pdev, const char *res_name)
4099{
4100 return pci_request_selected_regions(pdev,
4101 ((1 << PCI_STD_NUM_BARS) - 1), res_name);
4102}
4103EXPORT_SYMBOL(pci_request_regions);
4104
4105/**
4106 * pci_request_regions_exclusive - Reserve PCI I/O and memory resources
4107 * @pdev: PCI device whose resources are to be reserved
4108 * @res_name: Name to be associated with resource.
4109 *
4110 * Mark all PCI regions associated with PCI device @pdev as being reserved
4111 * by owner @res_name. Do not access any address inside the PCI regions
4112 * unless this call returns successfully.
4113 *
4114 * pci_request_regions_exclusive() will mark the region so that /dev/mem
4115 * and the sysfs MMIO access will not be allowed.
4116 *
4117 * Returns 0 on success, or %EBUSY on error. A warning message is also
4118 * printed on failure.
4119 */
4120int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name)
4121{
4122 return pci_request_selected_regions_exclusive(pdev,
4123 ((1 << PCI_STD_NUM_BARS) - 1), res_name);
4124}
4125EXPORT_SYMBOL(pci_request_regions_exclusive);
4126
4127/*
4128 * Record the PCI IO range (expressed as CPU physical address + size).
4129 * Return a negative value if an error has occurred, zero otherwise
4130 */
4131int pci_register_io_range(struct fwnode_handle *fwnode, phys_addr_t addr,
4132 resource_size_t size)
4133{
4134 int ret = 0;
4135#ifdef PCI_IOBASE
4136 struct logic_pio_hwaddr *range;
4137
4138 if (!size || addr + size < addr)
4139 return -EINVAL;
4140
4141 range = kzalloc(sizeof(*range), GFP_ATOMIC);
4142 if (!range)
4143 return -ENOMEM;
4144
4145 range->fwnode = fwnode;
4146 range->size = size;
4147 range->hw_start = addr;
4148 range->flags = LOGIC_PIO_CPU_MMIO;
4149
4150 ret = logic_pio_register_range(range);
4151 if (ret)
4152 kfree(range);
4153
4154 /* Ignore duplicates due to deferred probing */
4155 if (ret == -EEXIST)
4156 ret = 0;
4157#endif
4158
4159 return ret;
4160}
4161
4162phys_addr_t pci_pio_to_address(unsigned long pio)
4163{
4164 phys_addr_t address = (phys_addr_t)OF_BAD_ADDR;
4165
4166#ifdef PCI_IOBASE
4167 if (pio >= MMIO_UPPER_LIMIT)
4168 return address;
4169
4170 address = logic_pio_to_hwaddr(pio);
4171#endif
4172
4173 return address;
4174}
4175EXPORT_SYMBOL_GPL(pci_pio_to_address);
4176
4177unsigned long __weak pci_address_to_pio(phys_addr_t address)
4178{
4179#ifdef PCI_IOBASE
4180 return logic_pio_trans_cpuaddr(address);
4181#else
4182 if (address > IO_SPACE_LIMIT)
4183 return (unsigned long)-1;
4184
4185 return (unsigned long) address;
4186#endif
4187}
4188
4189/**
4190 * pci_remap_iospace - Remap the memory mapped I/O space
4191 * @res: Resource describing the I/O space
4192 * @phys_addr: physical address of range to be mapped
4193 *
4194 * Remap the memory mapped I/O space described by the @res and the CPU
4195 * physical address @phys_addr into virtual address space. Only
4196 * architectures that have memory mapped IO functions defined (and the
4197 * PCI_IOBASE value defined) should call this function.
4198 */
4199#ifndef pci_remap_iospace
4200int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr)
4201{
4202#if defined(PCI_IOBASE) && defined(CONFIG_MMU)
4203 unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start;
4204
4205 if (!(res->flags & IORESOURCE_IO))
4206 return -EINVAL;
4207
4208 if (res->end > IO_SPACE_LIMIT)
4209 return -EINVAL;
4210
4211 return ioremap_page_range(vaddr, vaddr + resource_size(res), phys_addr,
4212 pgprot_device(PAGE_KERNEL));
4213#else
4214 /*
4215 * This architecture does not have memory mapped I/O space,
4216 * so this function should never be called
4217 */
4218 WARN_ONCE(1, "This architecture does not support memory mapped I/O\n");
4219 return -ENODEV;
4220#endif
4221}
4222EXPORT_SYMBOL(pci_remap_iospace);
4223#endif
4224
4225/**
4226 * pci_unmap_iospace - Unmap the memory mapped I/O space
4227 * @res: resource to be unmapped
4228 *
4229 * Unmap the CPU virtual address @res from virtual address space. Only
4230 * architectures that have memory mapped IO functions defined (and the
4231 * PCI_IOBASE value defined) should call this function.
4232 */
4233void pci_unmap_iospace(struct resource *res)
4234{
4235#if defined(PCI_IOBASE) && defined(CONFIG_MMU)
4236 unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start;
4237
4238 vunmap_range(vaddr, vaddr + resource_size(res));
4239#endif
4240}
4241EXPORT_SYMBOL(pci_unmap_iospace);
4242
4243static void devm_pci_unmap_iospace(struct device *dev, void *ptr)
4244{
4245 struct resource **res = ptr;
4246
4247 pci_unmap_iospace(*res);
4248}
4249
4250/**
4251 * devm_pci_remap_iospace - Managed pci_remap_iospace()
4252 * @dev: Generic device to remap IO address for
4253 * @res: Resource describing the I/O space
4254 * @phys_addr: physical address of range to be mapped
4255 *
4256 * Managed pci_remap_iospace(). Map is automatically unmapped on driver
4257 * detach.
4258 */
4259int devm_pci_remap_iospace(struct device *dev, const struct resource *res,
4260 phys_addr_t phys_addr)
4261{
4262 const struct resource **ptr;
4263 int error;
4264
4265 ptr = devres_alloc(devm_pci_unmap_iospace, sizeof(*ptr), GFP_KERNEL);
4266 if (!ptr)
4267 return -ENOMEM;
4268
4269 error = pci_remap_iospace(res, phys_addr);
4270 if (error) {
4271 devres_free(ptr);
4272 } else {
4273 *ptr = res;
4274 devres_add(dev, ptr);
4275 }
4276
4277 return error;
4278}
4279EXPORT_SYMBOL(devm_pci_remap_iospace);
4280
4281/**
4282 * devm_pci_remap_cfgspace - Managed pci_remap_cfgspace()
4283 * @dev: Generic device to remap IO address for
4284 * @offset: Resource address to map
4285 * @size: Size of map
4286 *
4287 * Managed pci_remap_cfgspace(). Map is automatically unmapped on driver
4288 * detach.
4289 */
4290void __iomem *devm_pci_remap_cfgspace(struct device *dev,
4291 resource_size_t offset,
4292 resource_size_t size)
4293{
4294 void __iomem **ptr, *addr;
4295
4296 ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL);
4297 if (!ptr)
4298 return NULL;
4299
4300 addr = pci_remap_cfgspace(offset, size);
4301 if (addr) {
4302 *ptr = addr;
4303 devres_add(dev, ptr);
4304 } else
4305 devres_free(ptr);
4306
4307 return addr;
4308}
4309EXPORT_SYMBOL(devm_pci_remap_cfgspace);
4310
4311/**
4312 * devm_pci_remap_cfg_resource - check, request region and ioremap cfg resource
4313 * @dev: generic device to handle the resource for
4314 * @res: configuration space resource to be handled
4315 *
4316 * Checks that a resource is a valid memory region, requests the memory
4317 * region and ioremaps with pci_remap_cfgspace() API that ensures the
4318 * proper PCI configuration space memory attributes are guaranteed.
4319 *
4320 * All operations are managed and will be undone on driver detach.
4321 *
4322 * Returns a pointer to the remapped memory or an ERR_PTR() encoded error code
4323 * on failure. Usage example::
4324 *
4325 * res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
4326 * base = devm_pci_remap_cfg_resource(&pdev->dev, res);
4327 * if (IS_ERR(base))
4328 * return PTR_ERR(base);
4329 */
4330void __iomem *devm_pci_remap_cfg_resource(struct device *dev,
4331 struct resource *res)
4332{
4333 resource_size_t size;
4334 const char *name;
4335 void __iomem *dest_ptr;
4336
4337 BUG_ON(!dev);
4338
4339 if (!res || resource_type(res) != IORESOURCE_MEM) {
4340 dev_err(dev, "invalid resource\n");
4341 return IOMEM_ERR_PTR(-EINVAL);
4342 }
4343
4344 size = resource_size(res);
4345
4346 if (res->name)
4347 name = devm_kasprintf(dev, GFP_KERNEL, "%s %s", dev_name(dev),
4348 res->name);
4349 else
4350 name = devm_kstrdup(dev, dev_name(dev), GFP_KERNEL);
4351 if (!name)
4352 return IOMEM_ERR_PTR(-ENOMEM);
4353
4354 if (!devm_request_mem_region(dev, res->start, size, name)) {
4355 dev_err(dev, "can't request region for resource %pR\n", res);
4356 return IOMEM_ERR_PTR(-EBUSY);
4357 }
4358
4359 dest_ptr = devm_pci_remap_cfgspace(dev, res->start, size);
4360 if (!dest_ptr) {
4361 dev_err(dev, "ioremap failed for resource %pR\n", res);
4362 devm_release_mem_region(dev, res->start, size);
4363 dest_ptr = IOMEM_ERR_PTR(-ENOMEM);
4364 }
4365
4366 return dest_ptr;
4367}
4368EXPORT_SYMBOL(devm_pci_remap_cfg_resource);
4369
4370static void __pci_set_master(struct pci_dev *dev, bool enable)
4371{
4372 u16 old_cmd, cmd;
4373
4374 pci_read_config_word(dev, PCI_COMMAND, &old_cmd);
4375 if (enable)
4376 cmd = old_cmd | PCI_COMMAND_MASTER;
4377 else
4378 cmd = old_cmd & ~PCI_COMMAND_MASTER;
4379 if (cmd != old_cmd) {
4380 pci_dbg(dev, "%s bus mastering\n",
4381 enable ? "enabling" : "disabling");
4382 pci_write_config_word(dev, PCI_COMMAND, cmd);
4383 }
4384 dev->is_busmaster = enable;
4385}
4386
4387/**
4388 * pcibios_setup - process "pci=" kernel boot arguments
4389 * @str: string used to pass in "pci=" kernel boot arguments
4390 *
4391 * Process kernel boot arguments. This is the default implementation.
4392 * Architecture specific implementations can override this as necessary.
4393 */
4394char * __weak __init pcibios_setup(char *str)
4395{
4396 return str;
4397}
4398
4399/**
4400 * pcibios_set_master - enable PCI bus-mastering for device dev
4401 * @dev: the PCI device to enable
4402 *
4403 * Enables PCI bus-mastering for the device. This is the default
4404 * implementation. Architecture specific implementations can override
4405 * this if necessary.
4406 */
4407void __weak pcibios_set_master(struct pci_dev *dev)
4408{
4409 u8 lat;
4410
4411 /* The latency timer doesn't apply to PCIe (either Type 0 or Type 1) */
4412 if (pci_is_pcie(dev))
4413 return;
4414
4415 pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat);
4416 if (lat < 16)
4417 lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency;
4418 else if (lat > pcibios_max_latency)
4419 lat = pcibios_max_latency;
4420 else
4421 return;
4422
4423 pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat);
4424}
4425
4426/**
4427 * pci_set_master - enables bus-mastering for device dev
4428 * @dev: the PCI device to enable
4429 *
4430 * Enables bus-mastering on the device and calls pcibios_set_master()
4431 * to do the needed arch specific settings.
4432 */
4433void pci_set_master(struct pci_dev *dev)
4434{
4435 __pci_set_master(dev, true);
4436 pcibios_set_master(dev);
4437}
4438EXPORT_SYMBOL(pci_set_master);
4439
4440/**
4441 * pci_clear_master - disables bus-mastering for device dev
4442 * @dev: the PCI device to disable
4443 */
4444void pci_clear_master(struct pci_dev *dev)
4445{
4446 __pci_set_master(dev, false);
4447}
4448EXPORT_SYMBOL(pci_clear_master);
4449
4450/**
4451 * pci_set_cacheline_size - ensure the CACHE_LINE_SIZE register is programmed
4452 * @dev: the PCI device for which MWI is to be enabled
4453 *
4454 * Helper function for pci_set_mwi.
4455 * Originally copied from drivers/net/acenic.c.
4456 * Copyright 1998-2001 by Jes Sorensen, <jes@trained-monkey.org>.
4457 *
4458 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
4459 */
4460int pci_set_cacheline_size(struct pci_dev *dev)
4461{
4462 u8 cacheline_size;
4463
4464 if (!pci_cache_line_size)
4465 return -EINVAL;
4466
4467 /* Validate current setting: the PCI_CACHE_LINE_SIZE must be
4468 equal to or multiple of the right value. */
4469 pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
4470 if (cacheline_size >= pci_cache_line_size &&
4471 (cacheline_size % pci_cache_line_size) == 0)
4472 return 0;
4473
4474 /* Write the correct value. */
4475 pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, pci_cache_line_size);
4476 /* Read it back. */
4477 pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
4478 if (cacheline_size == pci_cache_line_size)
4479 return 0;
4480
4481 pci_dbg(dev, "cache line size of %d is not supported\n",
4482 pci_cache_line_size << 2);
4483
4484 return -EINVAL;
4485}
4486EXPORT_SYMBOL_GPL(pci_set_cacheline_size);
4487
4488/**
4489 * pci_set_mwi - enables memory-write-invalidate PCI transaction
4490 * @dev: the PCI device for which MWI is enabled
4491 *
4492 * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND.
4493 *
4494 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
4495 */
4496int pci_set_mwi(struct pci_dev *dev)
4497{
4498#ifdef PCI_DISABLE_MWI
4499 return 0;
4500#else
4501 int rc;
4502 u16 cmd;
4503
4504 rc = pci_set_cacheline_size(dev);
4505 if (rc)
4506 return rc;
4507
4508 pci_read_config_word(dev, PCI_COMMAND, &cmd);
4509 if (!(cmd & PCI_COMMAND_INVALIDATE)) {
4510 pci_dbg(dev, "enabling Mem-Wr-Inval\n");
4511 cmd |= PCI_COMMAND_INVALIDATE;
4512 pci_write_config_word(dev, PCI_COMMAND, cmd);
4513 }
4514 return 0;
4515#endif
4516}
4517EXPORT_SYMBOL(pci_set_mwi);
4518
4519/**
4520 * pcim_set_mwi - a device-managed pci_set_mwi()
4521 * @dev: the PCI device for which MWI is enabled
4522 *
4523 * Managed pci_set_mwi().
4524 *
4525 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
4526 */
4527int pcim_set_mwi(struct pci_dev *dev)
4528{
4529 struct pci_devres *dr;
4530
4531 dr = find_pci_dr(dev);
4532 if (!dr)
4533 return -ENOMEM;
4534
4535 dr->mwi = 1;
4536 return pci_set_mwi(dev);
4537}
4538EXPORT_SYMBOL(pcim_set_mwi);
4539
4540/**
4541 * pci_try_set_mwi - enables memory-write-invalidate PCI transaction
4542 * @dev: the PCI device for which MWI is enabled
4543 *
4544 * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND.
4545 * Callers are not required to check the return value.
4546 *
4547 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
4548 */
4549int pci_try_set_mwi(struct pci_dev *dev)
4550{
4551#ifdef PCI_DISABLE_MWI
4552 return 0;
4553#else
4554 return pci_set_mwi(dev);
4555#endif
4556}
4557EXPORT_SYMBOL(pci_try_set_mwi);
4558
4559/**
4560 * pci_clear_mwi - disables Memory-Write-Invalidate for device dev
4561 * @dev: the PCI device to disable
4562 *
4563 * Disables PCI Memory-Write-Invalidate transaction on the device
4564 */
4565void pci_clear_mwi(struct pci_dev *dev)
4566{
4567#ifndef PCI_DISABLE_MWI
4568 u16 cmd;
4569
4570 pci_read_config_word(dev, PCI_COMMAND, &cmd);
4571 if (cmd & PCI_COMMAND_INVALIDATE) {
4572 cmd &= ~PCI_COMMAND_INVALIDATE;
4573 pci_write_config_word(dev, PCI_COMMAND, cmd);
4574 }
4575#endif
4576}
4577EXPORT_SYMBOL(pci_clear_mwi);
4578
4579/**
4580 * pci_disable_parity - disable parity checking for device
4581 * @dev: the PCI device to operate on
4582 *
4583 * Disable parity checking for device @dev
4584 */
4585void pci_disable_parity(struct pci_dev *dev)
4586{
4587 u16 cmd;
4588
4589 pci_read_config_word(dev, PCI_COMMAND, &cmd);
4590 if (cmd & PCI_COMMAND_PARITY) {
4591 cmd &= ~PCI_COMMAND_PARITY;
4592 pci_write_config_word(dev, PCI_COMMAND, cmd);
4593 }
4594}
4595
4596/**
4597 * pci_intx - enables/disables PCI INTx for device dev
4598 * @pdev: the PCI device to operate on
4599 * @enable: boolean: whether to enable or disable PCI INTx
4600 *
4601 * Enables/disables PCI INTx for device @pdev
4602 */
4603void pci_intx(struct pci_dev *pdev, int enable)
4604{
4605 u16 pci_command, new;
4606
4607 pci_read_config_word(pdev, PCI_COMMAND, &pci_command);
4608
4609 if (enable)
4610 new = pci_command & ~PCI_COMMAND_INTX_DISABLE;
4611 else
4612 new = pci_command | PCI_COMMAND_INTX_DISABLE;
4613
4614 if (new != pci_command) {
4615 struct pci_devres *dr;
4616
4617 pci_write_config_word(pdev, PCI_COMMAND, new);
4618
4619 dr = find_pci_dr(pdev);
4620 if (dr && !dr->restore_intx) {
4621 dr->restore_intx = 1;
4622 dr->orig_intx = !enable;
4623 }
4624 }
4625}
4626EXPORT_SYMBOL_GPL(pci_intx);
4627
4628static bool pci_check_and_set_intx_mask(struct pci_dev *dev, bool mask)
4629{
4630 struct pci_bus *bus = dev->bus;
4631 bool mask_updated = true;
4632 u32 cmd_status_dword;
4633 u16 origcmd, newcmd;
4634 unsigned long flags;
4635 bool irq_pending;
4636
4637 /*
4638 * We do a single dword read to retrieve both command and status.
4639 * Document assumptions that make this possible.
4640 */
4641 BUILD_BUG_ON(PCI_COMMAND % 4);
4642 BUILD_BUG_ON(PCI_COMMAND + 2 != PCI_STATUS);
4643
4644 raw_spin_lock_irqsave(&pci_lock, flags);
4645
4646 bus->ops->read(bus, dev->devfn, PCI_COMMAND, 4, &cmd_status_dword);
4647
4648 irq_pending = (cmd_status_dword >> 16) & PCI_STATUS_INTERRUPT;
4649
4650 /*
4651 * Check interrupt status register to see whether our device
4652 * triggered the interrupt (when masking) or the next IRQ is
4653 * already pending (when unmasking).
4654 */
4655 if (mask != irq_pending) {
4656 mask_updated = false;
4657 goto done;
4658 }
4659
4660 origcmd = cmd_status_dword;
4661 newcmd = origcmd & ~PCI_COMMAND_INTX_DISABLE;
4662 if (mask)
4663 newcmd |= PCI_COMMAND_INTX_DISABLE;
4664 if (newcmd != origcmd)
4665 bus->ops->write(bus, dev->devfn, PCI_COMMAND, 2, newcmd);
4666
4667done:
4668 raw_spin_unlock_irqrestore(&pci_lock, flags);
4669
4670 return mask_updated;
4671}
4672
4673/**
4674 * pci_check_and_mask_intx - mask INTx on pending interrupt
4675 * @dev: the PCI device to operate on
4676 *
4677 * Check if the device dev has its INTx line asserted, mask it and return
4678 * true in that case. False is returned if no interrupt was pending.
4679 */
4680bool pci_check_and_mask_intx(struct pci_dev *dev)
4681{
4682 return pci_check_and_set_intx_mask(dev, true);
4683}
4684EXPORT_SYMBOL_GPL(pci_check_and_mask_intx);
4685
4686/**
4687 * pci_check_and_unmask_intx - unmask INTx if no interrupt is pending
4688 * @dev: the PCI device to operate on
4689 *
4690 * Check if the device dev has its INTx line asserted, unmask it if not and
4691 * return true. False is returned and the mask remains active if there was
4692 * still an interrupt pending.
4693 */
4694bool pci_check_and_unmask_intx(struct pci_dev *dev)
4695{
4696 return pci_check_and_set_intx_mask(dev, false);
4697}
4698EXPORT_SYMBOL_GPL(pci_check_and_unmask_intx);
4699
4700/**
4701 * pci_wait_for_pending_transaction - wait for pending transaction
4702 * @dev: the PCI device to operate on
4703 *
4704 * Return 0 if transaction is pending 1 otherwise.
4705 */
4706int pci_wait_for_pending_transaction(struct pci_dev *dev)
4707{
4708 if (!pci_is_pcie(dev))
4709 return 1;
4710
4711 return pci_wait_for_pending(dev, pci_pcie_cap(dev) + PCI_EXP_DEVSTA,
4712 PCI_EXP_DEVSTA_TRPND);
4713}
4714EXPORT_SYMBOL(pci_wait_for_pending_transaction);
4715
4716/**
4717 * pcie_flr - initiate a PCIe function level reset
4718 * @dev: device to reset
4719 *
4720 * Initiate a function level reset unconditionally on @dev without
4721 * checking any flags and DEVCAP
4722 */
4723int pcie_flr(struct pci_dev *dev)
4724{
4725 if (!pci_wait_for_pending_transaction(dev))
4726 pci_err(dev, "timed out waiting for pending transaction; performing function level reset anyway\n");
4727
4728 pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR);
4729
4730 if (dev->imm_ready)
4731 return 0;
4732
4733 /*
4734 * Per PCIe r4.0, sec 6.6.2, a device must complete an FLR within
4735 * 100ms, but may silently discard requests while the FLR is in
4736 * progress. Wait 100ms before trying to access the device.
4737 */
4738 msleep(100);
4739
4740 return pci_dev_wait(dev, "FLR", PCIE_RESET_READY_POLL_MS);
4741}
4742EXPORT_SYMBOL_GPL(pcie_flr);
4743
4744/**
4745 * pcie_reset_flr - initiate a PCIe function level reset
4746 * @dev: device to reset
4747 * @probe: if true, return 0 if device can be reset this way
4748 *
4749 * Initiate a function level reset on @dev.
4750 */
4751int pcie_reset_flr(struct pci_dev *dev, bool probe)
4752{
4753 if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
4754 return -ENOTTY;
4755
4756 if (!(dev->devcap & PCI_EXP_DEVCAP_FLR))
4757 return -ENOTTY;
4758
4759 if (probe)
4760 return 0;
4761
4762 return pcie_flr(dev);
4763}
4764EXPORT_SYMBOL_GPL(pcie_reset_flr);
4765
4766static int pci_af_flr(struct pci_dev *dev, bool probe)
4767{
4768 int pos;
4769 u8 cap;
4770
4771 pos = pci_find_capability(dev, PCI_CAP_ID_AF);
4772 if (!pos)
4773 return -ENOTTY;
4774
4775 if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
4776 return -ENOTTY;
4777
4778 pci_read_config_byte(dev, pos + PCI_AF_CAP, &cap);
4779 if (!(cap & PCI_AF_CAP_TP) || !(cap & PCI_AF_CAP_FLR))
4780 return -ENOTTY;
4781
4782 if (probe)
4783 return 0;
4784
4785 /*
4786 * Wait for Transaction Pending bit to clear. A word-aligned test
4787 * is used, so we use the control offset rather than status and shift
4788 * the test bit to match.
4789 */
4790 if (!pci_wait_for_pending(dev, pos + PCI_AF_CTRL,
4791 PCI_AF_STATUS_TP << 8))
4792 pci_err(dev, "timed out waiting for pending transaction; performing AF function level reset anyway\n");
4793
4794 pci_write_config_byte(dev, pos + PCI_AF_CTRL, PCI_AF_CTRL_FLR);
4795
4796 if (dev->imm_ready)
4797 return 0;
4798
4799 /*
4800 * Per Advanced Capabilities for Conventional PCI ECN, 13 April 2006,
4801 * updated 27 July 2006; a device must complete an FLR within
4802 * 100ms, but may silently discard requests while the FLR is in
4803 * progress. Wait 100ms before trying to access the device.
4804 */
4805 msleep(100);
4806
4807 return pci_dev_wait(dev, "AF_FLR", PCIE_RESET_READY_POLL_MS);
4808}
4809
4810/**
4811 * pci_pm_reset - Put device into PCI_D3 and back into PCI_D0.
4812 * @dev: Device to reset.
4813 * @probe: if true, return 0 if the device can be reset this way.
4814 *
4815 * If @dev supports native PCI PM and its PCI_PM_CTRL_NO_SOFT_RESET flag is
4816 * unset, it will be reinitialized internally when going from PCI_D3hot to
4817 * PCI_D0. If that's the case and the device is not in a low-power state
4818 * already, force it into PCI_D3hot and back to PCI_D0, causing it to be reset.
4819 *
4820 * NOTE: This causes the caller to sleep for twice the device power transition
4821 * cooldown period, which for the D0->D3hot and D3hot->D0 transitions is 10 ms
4822 * by default (i.e. unless the @dev's d3hot_delay field has a different value).
4823 * Moreover, only devices in D0 can be reset by this function.
4824 */
4825static int pci_pm_reset(struct pci_dev *dev, bool probe)
4826{
4827 u16 csr;
4828
4829 if (!dev->pm_cap || dev->dev_flags & PCI_DEV_FLAGS_NO_PM_RESET)
4830 return -ENOTTY;
4831
4832 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &csr);
4833 if (csr & PCI_PM_CTRL_NO_SOFT_RESET)
4834 return -ENOTTY;
4835
4836 if (probe)
4837 return 0;
4838
4839 if (dev->current_state != PCI_D0)
4840 return -EINVAL;
4841
4842 csr &= ~PCI_PM_CTRL_STATE_MASK;
4843 csr |= PCI_D3hot;
4844 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);
4845 pci_dev_d3_sleep(dev);
4846
4847 csr &= ~PCI_PM_CTRL_STATE_MASK;
4848 csr |= PCI_D0;
4849 pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);
4850 pci_dev_d3_sleep(dev);
4851
4852 return pci_dev_wait(dev, "PM D3hot->D0", PCIE_RESET_READY_POLL_MS);
4853}
4854
4855/**
4856 * pcie_wait_for_link_delay - Wait until link is active or inactive
4857 * @pdev: Bridge device
4858 * @active: waiting for active or inactive?
4859 * @delay: Delay to wait after link has become active (in ms)
4860 *
4861 * Use this to wait till link becomes active or inactive.
4862 */
4863static bool pcie_wait_for_link_delay(struct pci_dev *pdev, bool active,
4864 int delay)
4865{
4866 int timeout = 1000;
4867 bool ret;
4868 u16 lnk_status;
4869
4870 /*
4871 * Some controllers might not implement link active reporting. In this
4872 * case, we wait for 1000 ms + any delay requested by the caller.
4873 */
4874 if (!pdev->link_active_reporting) {
4875 msleep(timeout + delay);
4876 return true;
4877 }
4878
4879 /*
4880 * PCIe r4.0 sec 6.6.1, a component must enter LTSSM Detect within 20ms,
4881 * after which we should expect an link active if the reset was
4882 * successful. If so, software must wait a minimum 100ms before sending
4883 * configuration requests to devices downstream this port.
4884 *
4885 * If the link fails to activate, either the device was physically
4886 * removed or the link is permanently failed.
4887 */
4888 if (active)
4889 msleep(20);
4890 for (;;) {
4891 pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
4892 ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA);
4893 if (ret == active)
4894 break;
4895 if (timeout <= 0)
4896 break;
4897 msleep(10);
4898 timeout -= 10;
4899 }
4900 if (active && ret)
4901 msleep(delay);
4902
4903 return ret == active;
4904}
4905
4906/**
4907 * pcie_wait_for_link - Wait until link is active or inactive
4908 * @pdev: Bridge device
4909 * @active: waiting for active or inactive?
4910 *
4911 * Use this to wait till link becomes active or inactive.
4912 */
4913bool pcie_wait_for_link(struct pci_dev *pdev, bool active)
4914{
4915 return pcie_wait_for_link_delay(pdev, active, 100);
4916}
4917
4918/*
4919 * Find maximum D3cold delay required by all the devices on the bus. The
4920 * spec says 100 ms, but firmware can lower it and we allow drivers to
4921 * increase it as well.
4922 *
4923 * Called with @pci_bus_sem locked for reading.
4924 */
4925static int pci_bus_max_d3cold_delay(const struct pci_bus *bus)
4926{
4927 const struct pci_dev *pdev;
4928 int min_delay = 100;
4929 int max_delay = 0;
4930
4931 list_for_each_entry(pdev, &bus->devices, bus_list) {
4932 if (pdev->d3cold_delay < min_delay)
4933 min_delay = pdev->d3cold_delay;
4934 if (pdev->d3cold_delay > max_delay)
4935 max_delay = pdev->d3cold_delay;
4936 }
4937
4938 return max(min_delay, max_delay);
4939}
4940
4941/**
4942 * pci_bridge_wait_for_secondary_bus - Wait for secondary bus to be accessible
4943 * @dev: PCI bridge
4944 *
4945 * Handle necessary delays before access to the devices on the secondary
4946 * side of the bridge are permitted after D3cold to D0 transition.
4947 *
4948 * For PCIe this means the delays in PCIe 5.0 section 6.6.1. For
4949 * conventional PCI it means Tpvrh + Trhfa specified in PCI 3.0 section
4950 * 4.3.2.
4951 */
4952void pci_bridge_wait_for_secondary_bus(struct pci_dev *dev)
4953{
4954 struct pci_dev *child;
4955 int delay;
4956
4957 if (pci_dev_is_disconnected(dev))
4958 return;
4959
4960 if (!pci_is_bridge(dev) || !dev->bridge_d3)
4961 return;
4962
4963 down_read(&pci_bus_sem);
4964
4965 /*
4966 * We only deal with devices that are present currently on the bus.
4967 * For any hot-added devices the access delay is handled in pciehp
4968 * board_added(). In case of ACPI hotplug the firmware is expected
4969 * to configure the devices before OS is notified.
4970 */
4971 if (!dev->subordinate || list_empty(&dev->subordinate->devices)) {
4972 up_read(&pci_bus_sem);
4973 return;
4974 }
4975
4976 /* Take d3cold_delay requirements into account */
4977 delay = pci_bus_max_d3cold_delay(dev->subordinate);
4978 if (!delay) {
4979 up_read(&pci_bus_sem);
4980 return;
4981 }
4982
4983 child = list_first_entry(&dev->subordinate->devices, struct pci_dev,
4984 bus_list);
4985 up_read(&pci_bus_sem);
4986
4987 /*
4988 * Conventional PCI and PCI-X we need to wait Tpvrh + Trhfa before
4989 * accessing the device after reset (that is 1000 ms + 100 ms). In
4990 * practice this should not be needed because we don't do power
4991 * management for them (see pci_bridge_d3_possible()).
4992 */
4993 if (!pci_is_pcie(dev)) {
4994 pci_dbg(dev, "waiting %d ms for secondary bus\n", 1000 + delay);
4995 msleep(1000 + delay);
4996 return;
4997 }
4998
4999 /*
5000 * For PCIe downstream and root ports that do not support speeds
5001 * greater than 5 GT/s need to wait minimum 100 ms. For higher
5002 * speeds (gen3) we need to wait first for the data link layer to
5003 * become active.
5004 *
5005 * However, 100 ms is the minimum and the PCIe spec says the
5006 * software must allow at least 1s before it can determine that the
5007 * device that did not respond is a broken device. There is
5008 * evidence that 100 ms is not always enough, for example certain
5009 * Titan Ridge xHCI controller does not always respond to
5010 * configuration requests if we only wait for 100 ms (see
5011 * https://bugzilla.kernel.org/show_bug.cgi?id=203885).
5012 *
5013 * Therefore we wait for 100 ms and check for the device presence.
5014 * If it is still not present give it an additional 100 ms.
5015 */
5016 if (!pcie_downstream_port(dev))
5017 return;
5018
5019 if (pcie_get_speed_cap(dev) <= PCIE_SPEED_5_0GT) {
5020 pci_dbg(dev, "waiting %d ms for downstream link\n", delay);
5021 msleep(delay);
5022 } else {
5023 pci_dbg(dev, "waiting %d ms for downstream link, after activation\n",
5024 delay);
5025 if (!pcie_wait_for_link_delay(dev, true, delay)) {
5026 /* Did not train, no need to wait any further */
5027 pci_info(dev, "Data Link Layer Link Active not set in 1000 msec\n");
5028 return;
5029 }
5030 }
5031
5032 if (!pci_device_is_present(child)) {
5033 pci_dbg(child, "waiting additional %d ms to become accessible\n", delay);
5034 msleep(delay);
5035 }
5036}
5037
5038void pci_reset_secondary_bus(struct pci_dev *dev)
5039{
5040 u16 ctrl;
5041
5042 pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &ctrl);
5043 ctrl |= PCI_BRIDGE_CTL_BUS_RESET;
5044 pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl);
5045
5046 /*
5047 * PCI spec v3.0 7.6.4.2 requires minimum Trst of 1ms. Double
5048 * this to 2ms to ensure that we meet the minimum requirement.
5049 */
5050 msleep(2);
5051
5052 ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET;
5053 pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl);
5054
5055 /*
5056 * Trhfa for conventional PCI is 2^25 clock cycles.
5057 * Assuming a minimum 33MHz clock this results in a 1s
5058 * delay before we can consider subordinate devices to
5059 * be re-initialized. PCIe has some ways to shorten this,
5060 * but we don't make use of them yet.
5061 */
5062 ssleep(1);
5063}
5064
5065void __weak pcibios_reset_secondary_bus(struct pci_dev *dev)
5066{
5067 pci_reset_secondary_bus(dev);
5068}
5069
5070/**
5071 * pci_bridge_secondary_bus_reset - Reset the secondary bus on a PCI bridge.
5072 * @dev: Bridge device
5073 *
5074 * Use the bridge control register to assert reset on the secondary bus.
5075 * Devices on the secondary bus are left in power-on state.
5076 */
5077int pci_bridge_secondary_bus_reset(struct pci_dev *dev)
5078{
5079 pcibios_reset_secondary_bus(dev);
5080
5081 return pci_dev_wait(dev, "bus reset", PCIE_RESET_READY_POLL_MS);
5082}
5083EXPORT_SYMBOL_GPL(pci_bridge_secondary_bus_reset);
5084
5085static int pci_parent_bus_reset(struct pci_dev *dev, bool probe)
5086{
5087 struct pci_dev *pdev;
5088
5089 if (pci_is_root_bus(dev->bus) || dev->subordinate ||
5090 !dev->bus->self || dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)
5091 return -ENOTTY;
5092
5093 list_for_each_entry(pdev, &dev->bus->devices, bus_list)
5094 if (pdev != dev)
5095 return -ENOTTY;
5096
5097 if (probe)
5098 return 0;
5099
5100 return pci_bridge_secondary_bus_reset(dev->bus->self);
5101}
5102
5103static int pci_reset_hotplug_slot(struct hotplug_slot *hotplug, bool probe)
5104{
5105 int rc = -ENOTTY;
5106
5107 if (!hotplug || !try_module_get(hotplug->owner))
5108 return rc;
5109
5110 if (hotplug->ops->reset_slot)
5111 rc = hotplug->ops->reset_slot(hotplug, probe);
5112
5113 module_put(hotplug->owner);
5114
5115 return rc;
5116}
5117
5118static int pci_dev_reset_slot_function(struct pci_dev *dev, bool probe)
5119{
5120 if (dev->multifunction || dev->subordinate || !dev->slot ||
5121 dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)
5122 return -ENOTTY;
5123
5124 return pci_reset_hotplug_slot(dev->slot->hotplug, probe);
5125}
5126
5127static int pci_reset_bus_function(struct pci_dev *dev, bool probe)
5128{
5129 int rc;
5130
5131 rc = pci_dev_reset_slot_function(dev, probe);
5132 if (rc != -ENOTTY)
5133 return rc;
5134 return pci_parent_bus_reset(dev, probe);
5135}
5136
5137void pci_dev_lock(struct pci_dev *dev)
5138{
5139 /* block PM suspend, driver probe, etc. */
5140 device_lock(&dev->dev);
5141 pci_cfg_access_lock(dev);
5142}
5143EXPORT_SYMBOL_GPL(pci_dev_lock);
5144
5145/* Return 1 on successful lock, 0 on contention */
5146int pci_dev_trylock(struct pci_dev *dev)
5147{
5148 if (device_trylock(&dev->dev)) {
5149 if (pci_cfg_access_trylock(dev))
5150 return 1;
5151 device_unlock(&dev->dev);
5152 }
5153
5154 return 0;
5155}
5156EXPORT_SYMBOL_GPL(pci_dev_trylock);
5157
5158void pci_dev_unlock(struct pci_dev *dev)
5159{
5160 pci_cfg_access_unlock(dev);
5161 device_unlock(&dev->dev);
5162}
5163EXPORT_SYMBOL_GPL(pci_dev_unlock);
5164
5165static void pci_dev_save_and_disable(struct pci_dev *dev)
5166{
5167 const struct pci_error_handlers *err_handler =
5168 dev->driver ? dev->driver->err_handler : NULL;
5169
5170 /*
5171 * dev->driver->err_handler->reset_prepare() is protected against
5172 * races with ->remove() by the device lock, which must be held by
5173 * the caller.
5174 */
5175 if (err_handler && err_handler->reset_prepare)
5176 err_handler->reset_prepare(dev);
5177
5178 /*
5179 * Wake-up device prior to save. PM registers default to D0 after
5180 * reset and a simple register restore doesn't reliably return
5181 * to a non-D0 state anyway.
5182 */
5183 pci_set_power_state(dev, PCI_D0);
5184
5185 pci_save_state(dev);
5186 /*
5187 * Disable the device by clearing the Command register, except for
5188 * INTx-disable which is set. This not only disables MMIO and I/O port
5189 * BARs, but also prevents the device from being Bus Master, preventing
5190 * DMA from the device including MSI/MSI-X interrupts. For PCI 2.3
5191 * compliant devices, INTx-disable prevents legacy interrupts.
5192 */
5193 pci_write_config_word(dev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
5194}
5195
5196static void pci_dev_restore(struct pci_dev *dev)
5197{
5198 const struct pci_error_handlers *err_handler =
5199 dev->driver ? dev->driver->err_handler : NULL;
5200
5201 pci_restore_state(dev);
5202
5203 /*
5204 * dev->driver->err_handler->reset_done() is protected against
5205 * races with ->remove() by the device lock, which must be held by
5206 * the caller.
5207 */
5208 if (err_handler && err_handler->reset_done)
5209 err_handler->reset_done(dev);
5210}
5211
5212/* dev->reset_methods[] is a 0-terminated list of indices into this array */
5213static const struct pci_reset_fn_method pci_reset_fn_methods[] = {
5214 { },
5215 { pci_dev_specific_reset, .name = "device_specific" },
5216 { pci_dev_acpi_reset, .name = "acpi" },
5217 { pcie_reset_flr, .name = "flr" },
5218 { pci_af_flr, .name = "af_flr" },
5219 { pci_pm_reset, .name = "pm" },
5220 { pci_reset_bus_function, .name = "bus" },
5221};
5222
5223static ssize_t reset_method_show(struct device *dev,
5224 struct device_attribute *attr, char *buf)
5225{
5226 struct pci_dev *pdev = to_pci_dev(dev);
5227 ssize_t len = 0;
5228 int i, m;
5229
5230 for (i = 0; i < PCI_NUM_RESET_METHODS; i++) {
5231 m = pdev->reset_methods[i];
5232 if (!m)
5233 break;
5234
5235 len += sysfs_emit_at(buf, len, "%s%s", len ? " " : "",
5236 pci_reset_fn_methods[m].name);
5237 }
5238
5239 if (len)
5240 len += sysfs_emit_at(buf, len, "\n");
5241
5242 return len;
5243}
5244
5245static int reset_method_lookup(const char *name)
5246{
5247 int m;
5248
5249 for (m = 1; m < PCI_NUM_RESET_METHODS; m++) {
5250 if (sysfs_streq(name, pci_reset_fn_methods[m].name))
5251 return m;
5252 }
5253
5254 return 0; /* not found */
5255}
5256
5257static ssize_t reset_method_store(struct device *dev,
5258 struct device_attribute *attr,
5259 const char *buf, size_t count)
5260{
5261 struct pci_dev *pdev = to_pci_dev(dev);
5262 char *options, *name;
5263 int m, n;
5264 u8 reset_methods[PCI_NUM_RESET_METHODS] = { 0 };
5265
5266 if (sysfs_streq(buf, "")) {
5267 pdev->reset_methods[0] = 0;
5268 pci_warn(pdev, "All device reset methods disabled by user");
5269 return count;
5270 }
5271
5272 if (sysfs_streq(buf, "default")) {
5273 pci_init_reset_methods(pdev);
5274 return count;
5275 }
5276
5277 options = kstrndup(buf, count, GFP_KERNEL);
5278 if (!options)
5279 return -ENOMEM;
5280
5281 n = 0;
5282 while ((name = strsep(&options, " ")) != NULL) {
5283 if (sysfs_streq(name, ""))
5284 continue;
5285
5286 name = strim(name);
5287
5288 m = reset_method_lookup(name);
5289 if (!m) {
5290 pci_err(pdev, "Invalid reset method '%s'", name);
5291 goto error;
5292 }
5293
5294 if (pci_reset_fn_methods[m].reset_fn(pdev, PCI_RESET_PROBE)) {
5295 pci_err(pdev, "Unsupported reset method '%s'", name);
5296 goto error;
5297 }
5298
5299 if (n == PCI_NUM_RESET_METHODS - 1) {
5300 pci_err(pdev, "Too many reset methods\n");
5301 goto error;
5302 }
5303
5304 reset_methods[n++] = m;
5305 }
5306
5307 reset_methods[n] = 0;
5308
5309 /* Warn if dev-specific supported but not highest priority */
5310 if (pci_reset_fn_methods[1].reset_fn(pdev, PCI_RESET_PROBE) == 0 &&
5311 reset_methods[0] != 1)
5312 pci_warn(pdev, "Device-specific reset disabled/de-prioritized by user");
5313 memcpy(pdev->reset_methods, reset_methods, sizeof(pdev->reset_methods));
5314 kfree(options);
5315 return count;
5316
5317error:
5318 /* Leave previous methods unchanged */
5319 kfree(options);
5320 return -EINVAL;
5321}
5322static DEVICE_ATTR_RW(reset_method);
5323
5324static struct attribute *pci_dev_reset_method_attrs[] = {
5325 &dev_attr_reset_method.attr,
5326 NULL,
5327};
5328
5329static umode_t pci_dev_reset_method_attr_is_visible(struct kobject *kobj,
5330 struct attribute *a, int n)
5331{
5332 struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
5333
5334 if (!pci_reset_supported(pdev))
5335 return 0;
5336
5337 return a->mode;
5338}
5339
5340const struct attribute_group pci_dev_reset_method_attr_group = {
5341 .attrs = pci_dev_reset_method_attrs,
5342 .is_visible = pci_dev_reset_method_attr_is_visible,
5343};
5344
5345/**
5346 * __pci_reset_function_locked - reset a PCI device function while holding
5347 * the @dev mutex lock.
5348 * @dev: PCI device to reset
5349 *
5350 * Some devices allow an individual function to be reset without affecting
5351 * other functions in the same device. The PCI device must be responsive
5352 * to PCI config space in order to use this function.
5353 *
5354 * The device function is presumed to be unused and the caller is holding
5355 * the device mutex lock when this function is called.
5356 *
5357 * Resetting the device will make the contents of PCI configuration space
5358 * random, so any caller of this must be prepared to reinitialise the
5359 * device including MSI, bus mastering, BARs, decoding IO and memory spaces,
5360 * etc.
5361 *
5362 * Returns 0 if the device function was successfully reset or negative if the
5363 * device doesn't support resetting a single function.
5364 */
5365int __pci_reset_function_locked(struct pci_dev *dev)
5366{
5367 int i, m, rc;
5368
5369 might_sleep();
5370
5371 /*
5372 * A reset method returns -ENOTTY if it doesn't support this device and
5373 * we should try the next method.
5374 *
5375 * If it returns 0 (success), we're finished. If it returns any other
5376 * error, we're also finished: this indicates that further reset
5377 * mechanisms might be broken on the device.
5378 */
5379 for (i = 0; i < PCI_NUM_RESET_METHODS; i++) {
5380 m = dev->reset_methods[i];
5381 if (!m)
5382 return -ENOTTY;
5383
5384 rc = pci_reset_fn_methods[m].reset_fn(dev, PCI_RESET_DO_RESET);
5385 if (!rc)
5386 return 0;
5387 if (rc != -ENOTTY)
5388 return rc;
5389 }
5390
5391 return -ENOTTY;
5392}
5393EXPORT_SYMBOL_GPL(__pci_reset_function_locked);
5394
5395/**
5396 * pci_init_reset_methods - check whether device can be safely reset
5397 * and store supported reset mechanisms.
5398 * @dev: PCI device to check for reset mechanisms
5399 *
5400 * Some devices allow an individual function to be reset without affecting
5401 * other functions in the same device. The PCI device must be in D0-D3hot
5402 * state.
5403 *
5404 * Stores reset mechanisms supported by device in reset_methods byte array
5405 * which is a member of struct pci_dev.
5406 */
5407void pci_init_reset_methods(struct pci_dev *dev)
5408{
5409 int m, i, rc;
5410
5411 BUILD_BUG_ON(ARRAY_SIZE(pci_reset_fn_methods) != PCI_NUM_RESET_METHODS);
5412
5413 might_sleep();
5414
5415 i = 0;
5416 for (m = 1; m < PCI_NUM_RESET_METHODS; m++) {
5417 rc = pci_reset_fn_methods[m].reset_fn(dev, PCI_RESET_PROBE);
5418 if (!rc)
5419 dev->reset_methods[i++] = m;
5420 else if (rc != -ENOTTY)
5421 break;
5422 }
5423
5424 dev->reset_methods[i] = 0;
5425}
5426
5427/**
5428 * pci_reset_function - quiesce and reset a PCI device function
5429 * @dev: PCI device to reset
5430 *
5431 * Some devices allow an individual function to be reset without affecting
5432 * other functions in the same device. The PCI device must be responsive
5433 * to PCI config space in order to use this function.
5434 *
5435 * This function does not just reset the PCI portion of a device, but
5436 * clears all the state associated with the device. This function differs
5437 * from __pci_reset_function_locked() in that it saves and restores device state
5438 * over the reset and takes the PCI device lock.
5439 *
5440 * Returns 0 if the device function was successfully reset or negative if the
5441 * device doesn't support resetting a single function.
5442 */
5443int pci_reset_function(struct pci_dev *dev)
5444{
5445 int rc;
5446
5447 if (!pci_reset_supported(dev))
5448 return -ENOTTY;
5449
5450 pci_dev_lock(dev);
5451 pci_dev_save_and_disable(dev);
5452
5453 rc = __pci_reset_function_locked(dev);
5454
5455 pci_dev_restore(dev);
5456 pci_dev_unlock(dev);
5457
5458 return rc;
5459}
5460EXPORT_SYMBOL_GPL(pci_reset_function);
5461
5462/**
5463 * pci_reset_function_locked - quiesce and reset a PCI device function
5464 * @dev: PCI device to reset
5465 *
5466 * Some devices allow an individual function to be reset without affecting
5467 * other functions in the same device. The PCI device must be responsive
5468 * to PCI config space in order to use this function.
5469 *
5470 * This function does not just reset the PCI portion of a device, but
5471 * clears all the state associated with the device. This function differs
5472 * from __pci_reset_function_locked() in that it saves and restores device state
5473 * over the reset. It also differs from pci_reset_function() in that it
5474 * requires the PCI device lock to be held.
5475 *
5476 * Returns 0 if the device function was successfully reset or negative if the
5477 * device doesn't support resetting a single function.
5478 */
5479int pci_reset_function_locked(struct pci_dev *dev)
5480{
5481 int rc;
5482
5483 if (!pci_reset_supported(dev))
5484 return -ENOTTY;
5485
5486 pci_dev_save_and_disable(dev);
5487
5488 rc = __pci_reset_function_locked(dev);
5489
5490 pci_dev_restore(dev);
5491
5492 return rc;
5493}
5494EXPORT_SYMBOL_GPL(pci_reset_function_locked);
5495
5496/**
5497 * pci_try_reset_function - quiesce and reset a PCI device function
5498 * @dev: PCI device to reset
5499 *
5500 * Same as above, except return -EAGAIN if unable to lock device.
5501 */
5502int pci_try_reset_function(struct pci_dev *dev)
5503{
5504 int rc;
5505
5506 if (!pci_reset_supported(dev))
5507 return -ENOTTY;
5508
5509 if (!pci_dev_trylock(dev))
5510 return -EAGAIN;
5511
5512 pci_dev_save_and_disable(dev);
5513 rc = __pci_reset_function_locked(dev);
5514 pci_dev_restore(dev);
5515 pci_dev_unlock(dev);
5516
5517 return rc;
5518}
5519EXPORT_SYMBOL_GPL(pci_try_reset_function);
5520
5521/* Do any devices on or below this bus prevent a bus reset? */
5522static bool pci_bus_resetable(struct pci_bus *bus)
5523{
5524 struct pci_dev *dev;
5525
5526
5527 if (bus->self && (bus->self->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET))
5528 return false;
5529
5530 list_for_each_entry(dev, &bus->devices, bus_list) {
5531 if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET ||
5532 (dev->subordinate && !pci_bus_resetable(dev->subordinate)))
5533 return false;
5534 }
5535
5536 return true;
5537}
5538
5539/* Lock devices from the top of the tree down */
5540static void pci_bus_lock(struct pci_bus *bus)
5541{
5542 struct pci_dev *dev;
5543
5544 list_for_each_entry(dev, &bus->devices, bus_list) {
5545 pci_dev_lock(dev);
5546 if (dev->subordinate)
5547 pci_bus_lock(dev->subordinate);
5548 }
5549}
5550
5551/* Unlock devices from the bottom of the tree up */
5552static void pci_bus_unlock(struct pci_bus *bus)
5553{
5554 struct pci_dev *dev;
5555
5556 list_for_each_entry(dev, &bus->devices, bus_list) {
5557 if (dev->subordinate)
5558 pci_bus_unlock(dev->subordinate);
5559 pci_dev_unlock(dev);
5560 }
5561}
5562
5563/* Return 1 on successful lock, 0 on contention */
5564static int pci_bus_trylock(struct pci_bus *bus)
5565{
5566 struct pci_dev *dev;
5567
5568 list_for_each_entry(dev, &bus->devices, bus_list) {
5569 if (!pci_dev_trylock(dev))
5570 goto unlock;
5571 if (dev->subordinate) {
5572 if (!pci_bus_trylock(dev->subordinate)) {
5573 pci_dev_unlock(dev);
5574 goto unlock;
5575 }
5576 }
5577 }
5578 return 1;
5579
5580unlock:
5581 list_for_each_entry_continue_reverse(dev, &bus->devices, bus_list) {
5582 if (dev->subordinate)
5583 pci_bus_unlock(dev->subordinate);
5584 pci_dev_unlock(dev);
5585 }
5586 return 0;
5587}
5588
5589/* Do any devices on or below this slot prevent a bus reset? */
5590static bool pci_slot_resetable(struct pci_slot *slot)
5591{
5592 struct pci_dev *dev;
5593
5594 if (slot->bus->self &&
5595 (slot->bus->self->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET))
5596 return false;
5597
5598 list_for_each_entry(dev, &slot->bus->devices, bus_list) {
5599 if (!dev->slot || dev->slot != slot)
5600 continue;
5601 if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET ||
5602 (dev->subordinate && !pci_bus_resetable(dev->subordinate)))
5603 return false;
5604 }
5605
5606 return true;
5607}
5608
5609/* Lock devices from the top of the tree down */
5610static void pci_slot_lock(struct pci_slot *slot)
5611{
5612 struct pci_dev *dev;
5613
5614 list_for_each_entry(dev, &slot->bus->devices, bus_list) {
5615 if (!dev->slot || dev->slot != slot)
5616 continue;
5617 pci_dev_lock(dev);
5618 if (dev->subordinate)
5619 pci_bus_lock(dev->subordinate);
5620 }
5621}
5622
5623/* Unlock devices from the bottom of the tree up */
5624static void pci_slot_unlock(struct pci_slot *slot)
5625{
5626 struct pci_dev *dev;
5627
5628 list_for_each_entry(dev, &slot->bus->devices, bus_list) {
5629 if (!dev->slot || dev->slot != slot)
5630 continue;
5631 if (dev->subordinate)
5632 pci_bus_unlock(dev->subordinate);
5633 pci_dev_unlock(dev);
5634 }
5635}
5636
5637/* Return 1 on successful lock, 0 on contention */
5638static int pci_slot_trylock(struct pci_slot *slot)
5639{
5640 struct pci_dev *dev;
5641
5642 list_for_each_entry(dev, &slot->bus->devices, bus_list) {
5643 if (!dev->slot || dev->slot != slot)
5644 continue;
5645 if (!pci_dev_trylock(dev))
5646 goto unlock;
5647 if (dev->subordinate) {
5648 if (!pci_bus_trylock(dev->subordinate)) {
5649 pci_dev_unlock(dev);
5650 goto unlock;
5651 }
5652 }
5653 }
5654 return 1;
5655
5656unlock:
5657 list_for_each_entry_continue_reverse(dev,
5658 &slot->bus->devices, bus_list) {
5659 if (!dev->slot || dev->slot != slot)
5660 continue;
5661 if (dev->subordinate)
5662 pci_bus_unlock(dev->subordinate);
5663 pci_dev_unlock(dev);
5664 }
5665 return 0;
5666}
5667
5668/*
5669 * Save and disable devices from the top of the tree down while holding
5670 * the @dev mutex lock for the entire tree.
5671 */
5672static void pci_bus_save_and_disable_locked(struct pci_bus *bus)
5673{
5674 struct pci_dev *dev;
5675
5676 list_for_each_entry(dev, &bus->devices, bus_list) {
5677 pci_dev_save_and_disable(dev);
5678 if (dev->subordinate)
5679 pci_bus_save_and_disable_locked(dev->subordinate);
5680 }
5681}
5682
5683/*
5684 * Restore devices from top of the tree down while holding @dev mutex lock
5685 * for the entire tree. Parent bridges need to be restored before we can
5686 * get to subordinate devices.
5687 */
5688static void pci_bus_restore_locked(struct pci_bus *bus)
5689{
5690 struct pci_dev *dev;
5691
5692 list_for_each_entry(dev, &bus->devices, bus_list) {
5693 pci_dev_restore(dev);
5694 if (dev->subordinate)
5695 pci_bus_restore_locked(dev->subordinate);
5696 }
5697}
5698
5699/*
5700 * Save and disable devices from the top of the tree down while holding
5701 * the @dev mutex lock for the entire tree.
5702 */
5703static void pci_slot_save_and_disable_locked(struct pci_slot *slot)
5704{
5705 struct pci_dev *dev;
5706
5707 list_for_each_entry(dev, &slot->bus->devices, bus_list) {
5708 if (!dev->slot || dev->slot != slot)
5709 continue;
5710 pci_dev_save_and_disable(dev);
5711 if (dev->subordinate)
5712 pci_bus_save_and_disable_locked(dev->subordinate);
5713 }
5714}
5715
5716/*
5717 * Restore devices from top of the tree down while holding @dev mutex lock
5718 * for the entire tree. Parent bridges need to be restored before we can
5719 * get to subordinate devices.
5720 */
5721static void pci_slot_restore_locked(struct pci_slot *slot)
5722{
5723 struct pci_dev *dev;
5724
5725 list_for_each_entry(dev, &slot->bus->devices, bus_list) {
5726 if (!dev->slot || dev->slot != slot)
5727 continue;
5728 pci_dev_restore(dev);
5729 if (dev->subordinate)
5730 pci_bus_restore_locked(dev->subordinate);
5731 }
5732}
5733
5734static int pci_slot_reset(struct pci_slot *slot, bool probe)
5735{
5736 int rc;
5737
5738 if (!slot || !pci_slot_resetable(slot))
5739 return -ENOTTY;
5740
5741 if (!probe)
5742 pci_slot_lock(slot);
5743
5744 might_sleep();
5745
5746 rc = pci_reset_hotplug_slot(slot->hotplug, probe);
5747
5748 if (!probe)
5749 pci_slot_unlock(slot);
5750
5751 return rc;
5752}
5753
5754/**
5755 * pci_probe_reset_slot - probe whether a PCI slot can be reset
5756 * @slot: PCI slot to probe
5757 *
5758 * Return 0 if slot can be reset, negative if a slot reset is not supported.
5759 */
5760int pci_probe_reset_slot(struct pci_slot *slot)
5761{
5762 return pci_slot_reset(slot, PCI_RESET_PROBE);
5763}
5764EXPORT_SYMBOL_GPL(pci_probe_reset_slot);
5765
5766/**
5767 * __pci_reset_slot - Try to reset a PCI slot
5768 * @slot: PCI slot to reset
5769 *
5770 * A PCI bus may host multiple slots, each slot may support a reset mechanism
5771 * independent of other slots. For instance, some slots may support slot power
5772 * control. In the case of a 1:1 bus to slot architecture, this function may
5773 * wrap the bus reset to avoid spurious slot related events such as hotplug.
5774 * Generally a slot reset should be attempted before a bus reset. All of the
5775 * function of the slot and any subordinate buses behind the slot are reset
5776 * through this function. PCI config space of all devices in the slot and
5777 * behind the slot is saved before and restored after reset.
5778 *
5779 * Same as above except return -EAGAIN if the slot cannot be locked
5780 */
5781static int __pci_reset_slot(struct pci_slot *slot)
5782{
5783 int rc;
5784
5785 rc = pci_slot_reset(slot, PCI_RESET_PROBE);
5786 if (rc)
5787 return rc;
5788
5789 if (pci_slot_trylock(slot)) {
5790 pci_slot_save_and_disable_locked(slot);
5791 might_sleep();
5792 rc = pci_reset_hotplug_slot(slot->hotplug, PCI_RESET_DO_RESET);
5793 pci_slot_restore_locked(slot);
5794 pci_slot_unlock(slot);
5795 } else
5796 rc = -EAGAIN;
5797
5798 return rc;
5799}
5800
5801static int pci_bus_reset(struct pci_bus *bus, bool probe)
5802{
5803 int ret;
5804
5805 if (!bus->self || !pci_bus_resetable(bus))
5806 return -ENOTTY;
5807
5808 if (probe)
5809 return 0;
5810
5811 pci_bus_lock(bus);
5812
5813 might_sleep();
5814
5815 ret = pci_bridge_secondary_bus_reset(bus->self);
5816
5817 pci_bus_unlock(bus);
5818
5819 return ret;
5820}
5821
5822/**
5823 * pci_bus_error_reset - reset the bridge's subordinate bus
5824 * @bridge: The parent device that connects to the bus to reset
5825 *
5826 * This function will first try to reset the slots on this bus if the method is
5827 * available. If slot reset fails or is not available, this will fall back to a
5828 * secondary bus reset.
5829 */
5830int pci_bus_error_reset(struct pci_dev *bridge)
5831{
5832 struct pci_bus *bus = bridge->subordinate;
5833 struct pci_slot *slot;
5834
5835 if (!bus)
5836 return -ENOTTY;
5837
5838 mutex_lock(&pci_slot_mutex);
5839 if (list_empty(&bus->slots))
5840 goto bus_reset;
5841
5842 list_for_each_entry(slot, &bus->slots, list)
5843 if (pci_probe_reset_slot(slot))
5844 goto bus_reset;
5845
5846 list_for_each_entry(slot, &bus->slots, list)
5847 if (pci_slot_reset(slot, PCI_RESET_DO_RESET))
5848 goto bus_reset;
5849
5850 mutex_unlock(&pci_slot_mutex);
5851 return 0;
5852bus_reset:
5853 mutex_unlock(&pci_slot_mutex);
5854 return pci_bus_reset(bridge->subordinate, PCI_RESET_DO_RESET);
5855}
5856
5857/**
5858 * pci_probe_reset_bus - probe whether a PCI bus can be reset
5859 * @bus: PCI bus to probe
5860 *
5861 * Return 0 if bus can be reset, negative if a bus reset is not supported.
5862 */
5863int pci_probe_reset_bus(struct pci_bus *bus)
5864{
5865 return pci_bus_reset(bus, PCI_RESET_PROBE);
5866}
5867EXPORT_SYMBOL_GPL(pci_probe_reset_bus);
5868
5869/**
5870 * __pci_reset_bus - Try to reset a PCI bus
5871 * @bus: top level PCI bus to reset
5872 *
5873 * Same as above except return -EAGAIN if the bus cannot be locked
5874 */
5875static int __pci_reset_bus(struct pci_bus *bus)
5876{
5877 int rc;
5878
5879 rc = pci_bus_reset(bus, PCI_RESET_PROBE);
5880 if (rc)
5881 return rc;
5882
5883 if (pci_bus_trylock(bus)) {
5884 pci_bus_save_and_disable_locked(bus);
5885 might_sleep();
5886 rc = pci_bridge_secondary_bus_reset(bus->self);
5887 pci_bus_restore_locked(bus);
5888 pci_bus_unlock(bus);
5889 } else
5890 rc = -EAGAIN;
5891
5892 return rc;
5893}
5894
5895/**
5896 * pci_reset_bus - Try to reset a PCI bus
5897 * @pdev: top level PCI device to reset via slot/bus
5898 *
5899 * Same as above except return -EAGAIN if the bus cannot be locked
5900 */
5901int pci_reset_bus(struct pci_dev *pdev)
5902{
5903 return (!pci_probe_reset_slot(pdev->slot)) ?
5904 __pci_reset_slot(pdev->slot) : __pci_reset_bus(pdev->bus);
5905}
5906EXPORT_SYMBOL_GPL(pci_reset_bus);
5907
5908/**
5909 * pcix_get_max_mmrbc - get PCI-X maximum designed memory read byte count
5910 * @dev: PCI device to query
5911 *
5912 * Returns mmrbc: maximum designed memory read count in bytes or
5913 * appropriate error value.
5914 */
5915int pcix_get_max_mmrbc(struct pci_dev *dev)
5916{
5917 int cap;
5918 u32 stat;
5919
5920 cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
5921 if (!cap)
5922 return -EINVAL;
5923
5924 if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat))
5925 return -EINVAL;
5926
5927 return 512 << ((stat & PCI_X_STATUS_MAX_READ) >> 21);
5928}
5929EXPORT_SYMBOL(pcix_get_max_mmrbc);
5930
5931/**
5932 * pcix_get_mmrbc - get PCI-X maximum memory read byte count
5933 * @dev: PCI device to query
5934 *
5935 * Returns mmrbc: maximum memory read count in bytes or appropriate error
5936 * value.
5937 */
5938int pcix_get_mmrbc(struct pci_dev *dev)
5939{
5940 int cap;
5941 u16 cmd;
5942
5943 cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
5944 if (!cap)
5945 return -EINVAL;
5946
5947 if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd))
5948 return -EINVAL;
5949
5950 return 512 << ((cmd & PCI_X_CMD_MAX_READ) >> 2);
5951}
5952EXPORT_SYMBOL(pcix_get_mmrbc);
5953
5954/**
5955 * pcix_set_mmrbc - set PCI-X maximum memory read byte count
5956 * @dev: PCI device to query
5957 * @mmrbc: maximum memory read count in bytes
5958 * valid values are 512, 1024, 2048, 4096
5959 *
5960 * If possible sets maximum memory read byte count, some bridges have errata
5961 * that prevent this.
5962 */
5963int pcix_set_mmrbc(struct pci_dev *dev, int mmrbc)
5964{
5965 int cap;
5966 u32 stat, v, o;
5967 u16 cmd;
5968
5969 if (mmrbc < 512 || mmrbc > 4096 || !is_power_of_2(mmrbc))
5970 return -EINVAL;
5971
5972 v = ffs(mmrbc) - 10;
5973
5974 cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
5975 if (!cap)
5976 return -EINVAL;
5977
5978 if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat))
5979 return -EINVAL;
5980
5981 if (v > (stat & PCI_X_STATUS_MAX_READ) >> 21)
5982 return -E2BIG;
5983
5984 if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd))
5985 return -EINVAL;
5986
5987 o = (cmd & PCI_X_CMD_MAX_READ) >> 2;
5988 if (o != v) {
5989 if (v > o && (dev->bus->bus_flags & PCI_BUS_FLAGS_NO_MMRBC))
5990 return -EIO;
5991
5992 cmd &= ~PCI_X_CMD_MAX_READ;
5993 cmd |= v << 2;
5994 if (pci_write_config_word(dev, cap + PCI_X_CMD, cmd))
5995 return -EIO;
5996 }
5997 return 0;
5998}
5999EXPORT_SYMBOL(pcix_set_mmrbc);
6000
6001/**
6002 * pcie_get_readrq - get PCI Express read request size
6003 * @dev: PCI device to query
6004 *
6005 * Returns maximum memory read request in bytes or appropriate error value.
6006 */
6007int pcie_get_readrq(struct pci_dev *dev)
6008{
6009 u16 ctl;
6010
6011 pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl);
6012
6013 return 128 << ((ctl & PCI_EXP_DEVCTL_READRQ) >> 12);
6014}
6015EXPORT_SYMBOL(pcie_get_readrq);
6016
6017/**
6018 * pcie_set_readrq - set PCI Express maximum memory read request
6019 * @dev: PCI device to query
6020 * @rq: maximum memory read count in bytes
6021 * valid values are 128, 256, 512, 1024, 2048, 4096
6022 *
6023 * If possible sets maximum memory read request in bytes
6024 */
6025int pcie_set_readrq(struct pci_dev *dev, int rq)
6026{
6027 u16 v;
6028 int ret;
6029
6030 if (rq < 128 || rq > 4096 || !is_power_of_2(rq))
6031 return -EINVAL;
6032
6033 /*
6034 * If using the "performance" PCIe config, we clamp the read rq
6035 * size to the max packet size to keep the host bridge from
6036 * generating requests larger than we can cope with.
6037 */
6038 if (pcie_bus_config == PCIE_BUS_PERFORMANCE) {
6039 int mps = pcie_get_mps(dev);
6040
6041 if (mps < rq)
6042 rq = mps;
6043 }
6044
6045 v = (ffs(rq) - 8) << 12;
6046
6047 ret = pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
6048 PCI_EXP_DEVCTL_READRQ, v);
6049
6050 return pcibios_err_to_errno(ret);
6051}
6052EXPORT_SYMBOL(pcie_set_readrq);
6053
6054/**
6055 * pcie_get_mps - get PCI Express maximum payload size
6056 * @dev: PCI device to query
6057 *
6058 * Returns maximum payload size in bytes
6059 */
6060int pcie_get_mps(struct pci_dev *dev)
6061{
6062 u16 ctl;
6063
6064 pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl);
6065
6066 return 128 << ((ctl & PCI_EXP_DEVCTL_PAYLOAD) >> 5);
6067}
6068EXPORT_SYMBOL(pcie_get_mps);
6069
6070/**
6071 * pcie_set_mps - set PCI Express maximum payload size
6072 * @dev: PCI device to query
6073 * @mps: maximum payload size in bytes
6074 * valid values are 128, 256, 512, 1024, 2048, 4096
6075 *
6076 * If possible sets maximum payload size
6077 */
6078int pcie_set_mps(struct pci_dev *dev, int mps)
6079{
6080 u16 v;
6081 int ret;
6082
6083 if (mps < 128 || mps > 4096 || !is_power_of_2(mps))
6084 return -EINVAL;
6085
6086 v = ffs(mps) - 8;
6087 if (v > dev->pcie_mpss)
6088 return -EINVAL;
6089 v <<= 5;
6090
6091 ret = pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
6092 PCI_EXP_DEVCTL_PAYLOAD, v);
6093
6094 return pcibios_err_to_errno(ret);
6095}
6096EXPORT_SYMBOL(pcie_set_mps);
6097
6098/**
6099 * pcie_bandwidth_available - determine minimum link settings of a PCIe
6100 * device and its bandwidth limitation
6101 * @dev: PCI device to query
6102 * @limiting_dev: storage for device causing the bandwidth limitation
6103 * @speed: storage for speed of limiting device
6104 * @width: storage for width of limiting device
6105 *
6106 * Walk up the PCI device chain and find the point where the minimum
6107 * bandwidth is available. Return the bandwidth available there and (if
6108 * limiting_dev, speed, and width pointers are supplied) information about
6109 * that point. The bandwidth returned is in Mb/s, i.e., megabits/second of
6110 * raw bandwidth.
6111 */
6112u32 pcie_bandwidth_available(struct pci_dev *dev, struct pci_dev **limiting_dev,
6113 enum pci_bus_speed *speed,
6114 enum pcie_link_width *width)
6115{
6116 u16 lnksta;
6117 enum pci_bus_speed next_speed;
6118 enum pcie_link_width next_width;
6119 u32 bw, next_bw;
6120
6121 if (speed)
6122 *speed = PCI_SPEED_UNKNOWN;
6123 if (width)
6124 *width = PCIE_LNK_WIDTH_UNKNOWN;
6125
6126 bw = 0;
6127
6128 while (dev) {
6129 pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta);
6130
6131 next_speed = pcie_link_speed[lnksta & PCI_EXP_LNKSTA_CLS];
6132 next_width = (lnksta & PCI_EXP_LNKSTA_NLW) >>
6133 PCI_EXP_LNKSTA_NLW_SHIFT;
6134
6135 next_bw = next_width * PCIE_SPEED2MBS_ENC(next_speed);
6136
6137 /* Check if current device limits the total bandwidth */
6138 if (!bw || next_bw <= bw) {
6139 bw = next_bw;
6140
6141 if (limiting_dev)
6142 *limiting_dev = dev;
6143 if (speed)
6144 *speed = next_speed;
6145 if (width)
6146 *width = next_width;
6147 }
6148
6149 dev = pci_upstream_bridge(dev);
6150 }
6151
6152 return bw;
6153}
6154EXPORT_SYMBOL(pcie_bandwidth_available);
6155
6156/**
6157 * pcie_get_speed_cap - query for the PCI device's link speed capability
6158 * @dev: PCI device to query
6159 *
6160 * Query the PCI device speed capability. Return the maximum link speed
6161 * supported by the device.
6162 */
6163enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev)
6164{
6165 u32 lnkcap2, lnkcap;
6166
6167 /*
6168 * Link Capabilities 2 was added in PCIe r3.0, sec 7.8.18. The
6169 * implementation note there recommends using the Supported Link
6170 * Speeds Vector in Link Capabilities 2 when supported.
6171 *
6172 * Without Link Capabilities 2, i.e., prior to PCIe r3.0, software
6173 * should use the Supported Link Speeds field in Link Capabilities,
6174 * where only 2.5 GT/s and 5.0 GT/s speeds were defined.
6175 */
6176 pcie_capability_read_dword(dev, PCI_EXP_LNKCAP2, &lnkcap2);
6177
6178 /* PCIe r3.0-compliant */
6179 if (lnkcap2)
6180 return PCIE_LNKCAP2_SLS2SPEED(lnkcap2);
6181
6182 pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap);
6183 if ((lnkcap & PCI_EXP_LNKCAP_SLS) == PCI_EXP_LNKCAP_SLS_5_0GB)
6184 return PCIE_SPEED_5_0GT;
6185 else if ((lnkcap & PCI_EXP_LNKCAP_SLS) == PCI_EXP_LNKCAP_SLS_2_5GB)
6186 return PCIE_SPEED_2_5GT;
6187
6188 return PCI_SPEED_UNKNOWN;
6189}
6190EXPORT_SYMBOL(pcie_get_speed_cap);
6191
6192/**
6193 * pcie_get_width_cap - query for the PCI device's link width capability
6194 * @dev: PCI device to query
6195 *
6196 * Query the PCI device width capability. Return the maximum link width
6197 * supported by the device.
6198 */
6199enum pcie_link_width pcie_get_width_cap(struct pci_dev *dev)
6200{
6201 u32 lnkcap;
6202
6203 pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap);
6204 if (lnkcap)
6205 return (lnkcap & PCI_EXP_LNKCAP_MLW) >> 4;
6206
6207 return PCIE_LNK_WIDTH_UNKNOWN;
6208}
6209EXPORT_SYMBOL(pcie_get_width_cap);
6210
6211/**
6212 * pcie_bandwidth_capable - calculate a PCI device's link bandwidth capability
6213 * @dev: PCI device
6214 * @speed: storage for link speed
6215 * @width: storage for link width
6216 *
6217 * Calculate a PCI device's link bandwidth by querying for its link speed
6218 * and width, multiplying them, and applying encoding overhead. The result
6219 * is in Mb/s, i.e., megabits/second of raw bandwidth.
6220 */
6221u32 pcie_bandwidth_capable(struct pci_dev *dev, enum pci_bus_speed *speed,
6222 enum pcie_link_width *width)
6223{
6224 *speed = pcie_get_speed_cap(dev);
6225 *width = pcie_get_width_cap(dev);
6226
6227 if (*speed == PCI_SPEED_UNKNOWN || *width == PCIE_LNK_WIDTH_UNKNOWN)
6228 return 0;
6229
6230 return *width * PCIE_SPEED2MBS_ENC(*speed);
6231}
6232
6233/**
6234 * __pcie_print_link_status - Report the PCI device's link speed and width
6235 * @dev: PCI device to query
6236 * @verbose: Print info even when enough bandwidth is available
6237 *
6238 * If the available bandwidth at the device is less than the device is
6239 * capable of, report the device's maximum possible bandwidth and the
6240 * upstream link that limits its performance. If @verbose, always print
6241 * the available bandwidth, even if the device isn't constrained.
6242 */
6243void __pcie_print_link_status(struct pci_dev *dev, bool verbose)
6244{
6245 enum pcie_link_width width, width_cap;
6246 enum pci_bus_speed speed, speed_cap;
6247 struct pci_dev *limiting_dev = NULL;
6248 u32 bw_avail, bw_cap;
6249
6250 bw_cap = pcie_bandwidth_capable(dev, &speed_cap, &width_cap);
6251 bw_avail = pcie_bandwidth_available(dev, &limiting_dev, &speed, &width);
6252
6253 if (bw_avail >= bw_cap && verbose)
6254 pci_info(dev, "%u.%03u Gb/s available PCIe bandwidth (%s x%d link)\n",
6255 bw_cap / 1000, bw_cap % 1000,
6256 pci_speed_string(speed_cap), width_cap);
6257 else if (bw_avail < bw_cap)
6258 pci_info(dev, "%u.%03u Gb/s available PCIe bandwidth, limited by %s x%d link at %s (capable of %u.%03u Gb/s with %s x%d link)\n",
6259 bw_avail / 1000, bw_avail % 1000,
6260 pci_speed_string(speed), width,
6261 limiting_dev ? pci_name(limiting_dev) : "<unknown>",
6262 bw_cap / 1000, bw_cap % 1000,
6263 pci_speed_string(speed_cap), width_cap);
6264}
6265
6266/**
6267 * pcie_print_link_status - Report the PCI device's link speed and width
6268 * @dev: PCI device to query
6269 *
6270 * Report the available bandwidth at the device.
6271 */
6272void pcie_print_link_status(struct pci_dev *dev)
6273{
6274 __pcie_print_link_status(dev, true);
6275}
6276EXPORT_SYMBOL(pcie_print_link_status);
6277
6278/**
6279 * pci_select_bars - Make BAR mask from the type of resource
6280 * @dev: the PCI device for which BAR mask is made
6281 * @flags: resource type mask to be selected
6282 *
6283 * This helper routine makes bar mask from the type of resource.
6284 */
6285int pci_select_bars(struct pci_dev *dev, unsigned long flags)
6286{
6287 int i, bars = 0;
6288 for (i = 0; i < PCI_NUM_RESOURCES; i++)
6289 if (pci_resource_flags(dev, i) & flags)
6290 bars |= (1 << i);
6291 return bars;
6292}
6293EXPORT_SYMBOL(pci_select_bars);
6294
6295/* Some architectures require additional programming to enable VGA */
6296static arch_set_vga_state_t arch_set_vga_state;
6297
6298void __init pci_register_set_vga_state(arch_set_vga_state_t func)
6299{
6300 arch_set_vga_state = func; /* NULL disables */
6301}
6302
6303static int pci_set_vga_state_arch(struct pci_dev *dev, bool decode,
6304 unsigned int command_bits, u32 flags)
6305{
6306 if (arch_set_vga_state)
6307 return arch_set_vga_state(dev, decode, command_bits,
6308 flags);
6309 return 0;
6310}
6311
6312/**
6313 * pci_set_vga_state - set VGA decode state on device and parents if requested
6314 * @dev: the PCI device
6315 * @decode: true = enable decoding, false = disable decoding
6316 * @command_bits: PCI_COMMAND_IO and/or PCI_COMMAND_MEMORY
6317 * @flags: traverse ancestors and change bridges
6318 * CHANGE_BRIDGE_ONLY / CHANGE_BRIDGE
6319 */
6320int pci_set_vga_state(struct pci_dev *dev, bool decode,
6321 unsigned int command_bits, u32 flags)
6322{
6323 struct pci_bus *bus;
6324 struct pci_dev *bridge;
6325 u16 cmd;
6326 int rc;
6327
6328 WARN_ON((flags & PCI_VGA_STATE_CHANGE_DECODES) && (command_bits & ~(PCI_COMMAND_IO|PCI_COMMAND_MEMORY)));
6329
6330 /* ARCH specific VGA enables */
6331 rc = pci_set_vga_state_arch(dev, decode, command_bits, flags);
6332 if (rc)
6333 return rc;
6334
6335 if (flags & PCI_VGA_STATE_CHANGE_DECODES) {
6336 pci_read_config_word(dev, PCI_COMMAND, &cmd);
6337 if (decode)
6338 cmd |= command_bits;
6339 else
6340 cmd &= ~command_bits;
6341 pci_write_config_word(dev, PCI_COMMAND, cmd);
6342 }
6343
6344 if (!(flags & PCI_VGA_STATE_CHANGE_BRIDGE))
6345 return 0;
6346
6347 bus = dev->bus;
6348 while (bus) {
6349 bridge = bus->self;
6350 if (bridge) {
6351 pci_read_config_word(bridge, PCI_BRIDGE_CONTROL,
6352 &cmd);
6353 if (decode)
6354 cmd |= PCI_BRIDGE_CTL_VGA;
6355 else
6356 cmd &= ~PCI_BRIDGE_CTL_VGA;
6357 pci_write_config_word(bridge, PCI_BRIDGE_CONTROL,
6358 cmd);
6359 }
6360 bus = bus->parent;
6361 }
6362 return 0;
6363}
6364
6365#ifdef CONFIG_ACPI
6366bool pci_pr3_present(struct pci_dev *pdev)
6367{
6368 struct acpi_device *adev;
6369
6370 if (acpi_disabled)
6371 return false;
6372
6373 adev = ACPI_COMPANION(&pdev->dev);
6374 if (!adev)
6375 return false;
6376
6377 return adev->power.flags.power_resources &&
6378 acpi_has_method(adev->handle, "_PR3");
6379}
6380EXPORT_SYMBOL_GPL(pci_pr3_present);
6381#endif
6382
6383/**
6384 * pci_add_dma_alias - Add a DMA devfn alias for a device
6385 * @dev: the PCI device for which alias is added
6386 * @devfn_from: alias slot and function
6387 * @nr_devfns: number of subsequent devfns to alias
6388 *
6389 * This helper encodes an 8-bit devfn as a bit number in dma_alias_mask
6390 * which is used to program permissible bus-devfn source addresses for DMA
6391 * requests in an IOMMU. These aliases factor into IOMMU group creation
6392 * and are useful for devices generating DMA requests beyond or different
6393 * from their logical bus-devfn. Examples include device quirks where the
6394 * device simply uses the wrong devfn, as well as non-transparent bridges
6395 * where the alias may be a proxy for devices in another domain.
6396 *
6397 * IOMMU group creation is performed during device discovery or addition,
6398 * prior to any potential DMA mapping and therefore prior to driver probing
6399 * (especially for userspace assigned devices where IOMMU group definition
6400 * cannot be left as a userspace activity). DMA aliases should therefore
6401 * be configured via quirks, such as the PCI fixup header quirk.
6402 */
6403void pci_add_dma_alias(struct pci_dev *dev, u8 devfn_from,
6404 unsigned int nr_devfns)
6405{
6406 int devfn_to;
6407
6408 nr_devfns = min(nr_devfns, (unsigned int)MAX_NR_DEVFNS - devfn_from);
6409 devfn_to = devfn_from + nr_devfns - 1;
6410
6411 if (!dev->dma_alias_mask)
6412 dev->dma_alias_mask = bitmap_zalloc(MAX_NR_DEVFNS, GFP_KERNEL);
6413 if (!dev->dma_alias_mask) {
6414 pci_warn(dev, "Unable to allocate DMA alias mask\n");
6415 return;
6416 }
6417
6418 bitmap_set(dev->dma_alias_mask, devfn_from, nr_devfns);
6419
6420 if (nr_devfns == 1)
6421 pci_info(dev, "Enabling fixed DMA alias to %02x.%d\n",
6422 PCI_SLOT(devfn_from), PCI_FUNC(devfn_from));
6423 else if (nr_devfns > 1)
6424 pci_info(dev, "Enabling fixed DMA alias for devfn range from %02x.%d to %02x.%d\n",
6425 PCI_SLOT(devfn_from), PCI_FUNC(devfn_from),
6426 PCI_SLOT(devfn_to), PCI_FUNC(devfn_to));
6427}
6428
6429bool pci_devs_are_dma_aliases(struct pci_dev *dev1, struct pci_dev *dev2)
6430{
6431 return (dev1->dma_alias_mask &&
6432 test_bit(dev2->devfn, dev1->dma_alias_mask)) ||
6433 (dev2->dma_alias_mask &&
6434 test_bit(dev1->devfn, dev2->dma_alias_mask)) ||
6435 pci_real_dma_dev(dev1) == dev2 ||
6436 pci_real_dma_dev(dev2) == dev1;
6437}
6438
6439bool pci_device_is_present(struct pci_dev *pdev)
6440{
6441 u32 v;
6442
6443 /* Check PF if pdev is a VF, since VF Vendor/Device IDs are 0xffff */
6444 pdev = pci_physfn(pdev);
6445 if (pci_dev_is_disconnected(pdev))
6446 return false;
6447 return pci_bus_read_dev_vendor_id(pdev->bus, pdev->devfn, &v, 0);
6448}
6449EXPORT_SYMBOL_GPL(pci_device_is_present);
6450
6451void pci_ignore_hotplug(struct pci_dev *dev)
6452{
6453 struct pci_dev *bridge = dev->bus->self;
6454
6455 dev->ignore_hotplug = 1;
6456 /* Propagate the "ignore hotplug" setting to the parent bridge. */
6457 if (bridge)
6458 bridge->ignore_hotplug = 1;
6459}
6460EXPORT_SYMBOL_GPL(pci_ignore_hotplug);
6461
6462/**
6463 * pci_real_dma_dev - Get PCI DMA device for PCI device
6464 * @dev: the PCI device that may have a PCI DMA alias
6465 *
6466 * Permits the platform to provide architecture-specific functionality to
6467 * devices needing to alias DMA to another PCI device on another PCI bus. If
6468 * the PCI device is on the same bus, it is recommended to use
6469 * pci_add_dma_alias(). This is the default implementation. Architecture
6470 * implementations can override this.
6471 */
6472struct pci_dev __weak *pci_real_dma_dev(struct pci_dev *dev)
6473{
6474 return dev;
6475}
6476
6477resource_size_t __weak pcibios_default_alignment(void)
6478{
6479 return 0;
6480}
6481
6482/*
6483 * Arches that don't want to expose struct resource to userland as-is in
6484 * sysfs and /proc can implement their own pci_resource_to_user().
6485 */
6486void __weak pci_resource_to_user(const struct pci_dev *dev, int bar,
6487 const struct resource *rsrc,
6488 resource_size_t *start, resource_size_t *end)
6489{
6490 *start = rsrc->start;
6491 *end = rsrc->end;
6492}
6493
6494static char *resource_alignment_param;
6495static DEFINE_SPINLOCK(resource_alignment_lock);
6496
6497/**
6498 * pci_specified_resource_alignment - get resource alignment specified by user.
6499 * @dev: the PCI device to get
6500 * @resize: whether or not to change resources' size when reassigning alignment
6501 *
6502 * RETURNS: Resource alignment if it is specified.
6503 * Zero if it is not specified.
6504 */
6505static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev,
6506 bool *resize)
6507{
6508 int align_order, count;
6509 resource_size_t align = pcibios_default_alignment();
6510 const char *p;
6511 int ret;
6512
6513 spin_lock(&resource_alignment_lock);
6514 p = resource_alignment_param;
6515 if (!p || !*p)
6516 goto out;
6517 if (pci_has_flag(PCI_PROBE_ONLY)) {
6518 align = 0;
6519 pr_info_once("PCI: Ignoring requested alignments (PCI_PROBE_ONLY)\n");
6520 goto out;
6521 }
6522
6523 while (*p) {
6524 count = 0;
6525 if (sscanf(p, "%d%n", &align_order, &count) == 1 &&
6526 p[count] == '@') {
6527 p += count + 1;
6528 if (align_order > 63) {
6529 pr_err("PCI: Invalid requested alignment (order %d)\n",
6530 align_order);
6531 align_order = PAGE_SHIFT;
6532 }
6533 } else {
6534 align_order = PAGE_SHIFT;
6535 }
6536
6537 ret = pci_dev_str_match(dev, p, &p);
6538 if (ret == 1) {
6539 *resize = true;
6540 align = 1ULL << align_order;
6541 break;
6542 } else if (ret < 0) {
6543 pr_err("PCI: Can't parse resource_alignment parameter: %s\n",
6544 p);
6545 break;
6546 }
6547
6548 if (*p != ';' && *p != ',') {
6549 /* End of param or invalid format */
6550 break;
6551 }
6552 p++;
6553 }
6554out:
6555 spin_unlock(&resource_alignment_lock);
6556 return align;
6557}
6558
6559static void pci_request_resource_alignment(struct pci_dev *dev, int bar,
6560 resource_size_t align, bool resize)
6561{
6562 struct resource *r = &dev->resource[bar];
6563 resource_size_t size;
6564
6565 if (!(r->flags & IORESOURCE_MEM))
6566 return;
6567
6568 if (r->flags & IORESOURCE_PCI_FIXED) {
6569 pci_info(dev, "BAR%d %pR: ignoring requested alignment %#llx\n",
6570 bar, r, (unsigned long long)align);
6571 return;
6572 }
6573
6574 size = resource_size(r);
6575 if (size >= align)
6576 return;
6577
6578 /*
6579 * Increase the alignment of the resource. There are two ways we
6580 * can do this:
6581 *
6582 * 1) Increase the size of the resource. BARs are aligned on their
6583 * size, so when we reallocate space for this resource, we'll
6584 * allocate it with the larger alignment. This also prevents
6585 * assignment of any other BARs inside the alignment region, so
6586 * if we're requesting page alignment, this means no other BARs
6587 * will share the page.
6588 *
6589 * The disadvantage is that this makes the resource larger than
6590 * the hardware BAR, which may break drivers that compute things
6591 * based on the resource size, e.g., to find registers at a
6592 * fixed offset before the end of the BAR.
6593 *
6594 * 2) Retain the resource size, but use IORESOURCE_STARTALIGN and
6595 * set r->start to the desired alignment. By itself this
6596 * doesn't prevent other BARs being put inside the alignment
6597 * region, but if we realign *every* resource of every device in
6598 * the system, none of them will share an alignment region.
6599 *
6600 * When the user has requested alignment for only some devices via
6601 * the "pci=resource_alignment" argument, "resize" is true and we
6602 * use the first method. Otherwise we assume we're aligning all
6603 * devices and we use the second.
6604 */
6605
6606 pci_info(dev, "BAR%d %pR: requesting alignment to %#llx\n",
6607 bar, r, (unsigned long long)align);
6608
6609 if (resize) {
6610 r->start = 0;
6611 r->end = align - 1;
6612 } else {
6613 r->flags &= ~IORESOURCE_SIZEALIGN;
6614 r->flags |= IORESOURCE_STARTALIGN;
6615 r->start = align;
6616 r->end = r->start + size - 1;
6617 }
6618 r->flags |= IORESOURCE_UNSET;
6619}
6620
6621/*
6622 * This function disables memory decoding and releases memory resources
6623 * of the device specified by kernel's boot parameter 'pci=resource_alignment='.
6624 * It also rounds up size to specified alignment.
6625 * Later on, the kernel will assign page-aligned memory resource back
6626 * to the device.
6627 */
6628void pci_reassigndev_resource_alignment(struct pci_dev *dev)
6629{
6630 int i;
6631 struct resource *r;
6632 resource_size_t align;
6633 u16 command;
6634 bool resize = false;
6635
6636 /*
6637 * VF BARs are read-only zero according to SR-IOV spec r1.1, sec
6638 * 3.4.1.11. Their resources are allocated from the space
6639 * described by the VF BARx register in the PF's SR-IOV capability.
6640 * We can't influence their alignment here.
6641 */
6642 if (dev->is_virtfn)
6643 return;
6644
6645 /* check if specified PCI is target device to reassign */
6646 align = pci_specified_resource_alignment(dev, &resize);
6647 if (!align)
6648 return;
6649
6650 if (dev->hdr_type == PCI_HEADER_TYPE_NORMAL &&
6651 (dev->class >> 8) == PCI_CLASS_BRIDGE_HOST) {
6652 pci_warn(dev, "Can't reassign resources to host bridge\n");
6653 return;
6654 }
6655
6656 pci_read_config_word(dev, PCI_COMMAND, &command);
6657 command &= ~PCI_COMMAND_MEMORY;
6658 pci_write_config_word(dev, PCI_COMMAND, command);
6659
6660 for (i = 0; i <= PCI_ROM_RESOURCE; i++)
6661 pci_request_resource_alignment(dev, i, align, resize);
6662
6663 /*
6664 * Need to disable bridge's resource window,
6665 * to enable the kernel to reassign new resource
6666 * window later on.
6667 */
6668 if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
6669 for (i = PCI_BRIDGE_RESOURCES; i < PCI_NUM_RESOURCES; i++) {
6670 r = &dev->resource[i];
6671 if (!(r->flags & IORESOURCE_MEM))
6672 continue;
6673 r->flags |= IORESOURCE_UNSET;
6674 r->end = resource_size(r) - 1;
6675 r->start = 0;
6676 }
6677 pci_disable_bridge_window(dev);
6678 }
6679}
6680
6681static ssize_t resource_alignment_show(struct bus_type *bus, char *buf)
6682{
6683 size_t count = 0;
6684
6685 spin_lock(&resource_alignment_lock);
6686 if (resource_alignment_param)
6687 count = sysfs_emit(buf, "%s\n", resource_alignment_param);
6688 spin_unlock(&resource_alignment_lock);
6689
6690 return count;
6691}
6692
6693static ssize_t resource_alignment_store(struct bus_type *bus,
6694 const char *buf, size_t count)
6695{
6696 char *param, *old, *end;
6697
6698 if (count >= (PAGE_SIZE - 1))
6699 return -EINVAL;
6700
6701 param = kstrndup(buf, count, GFP_KERNEL);
6702 if (!param)
6703 return -ENOMEM;
6704
6705 end = strchr(param, '\n');
6706 if (end)
6707 *end = '\0';
6708
6709 spin_lock(&resource_alignment_lock);
6710 old = resource_alignment_param;
6711 if (strlen(param)) {
6712 resource_alignment_param = param;
6713 } else {
6714 kfree(param);
6715 resource_alignment_param = NULL;
6716 }
6717 spin_unlock(&resource_alignment_lock);
6718
6719 kfree(old);
6720
6721 return count;
6722}
6723
6724static BUS_ATTR_RW(resource_alignment);
6725
6726static int __init pci_resource_alignment_sysfs_init(void)
6727{
6728 return bus_create_file(&pci_bus_type,
6729 &bus_attr_resource_alignment);
6730}
6731late_initcall(pci_resource_alignment_sysfs_init);
6732
6733static void pci_no_domains(void)
6734{
6735#ifdef CONFIG_PCI_DOMAINS
6736 pci_domains_supported = 0;
6737#endif
6738}
6739
6740#ifdef CONFIG_PCI_DOMAINS_GENERIC
6741static DEFINE_IDA(pci_domain_nr_static_ida);
6742static DEFINE_IDA(pci_domain_nr_dynamic_ida);
6743
6744static void of_pci_reserve_static_domain_nr(void)
6745{
6746 struct device_node *np;
6747 int domain_nr;
6748
6749 for_each_node_by_type(np, "pci") {
6750 domain_nr = of_get_pci_domain_nr(np);
6751 if (domain_nr < 0)
6752 continue;
6753 /*
6754 * Permanently allocate domain_nr in dynamic_ida
6755 * to prevent it from dynamic allocation.
6756 */
6757 ida_alloc_range(&pci_domain_nr_dynamic_ida,
6758 domain_nr, domain_nr, GFP_KERNEL);
6759 }
6760}
6761
6762static int of_pci_bus_find_domain_nr(struct device *parent)
6763{
6764 static bool static_domains_reserved = false;
6765 int domain_nr;
6766
6767 /* On the first call scan device tree for static allocations. */
6768 if (!static_domains_reserved) {
6769 of_pci_reserve_static_domain_nr();
6770 static_domains_reserved = true;
6771 }
6772
6773 if (parent) {
6774 /*
6775 * If domain is in DT, allocate it in static IDA. This
6776 * prevents duplicate static allocations in case of errors
6777 * in DT.
6778 */
6779 domain_nr = of_get_pci_domain_nr(parent->of_node);
6780 if (domain_nr >= 0)
6781 return ida_alloc_range(&pci_domain_nr_static_ida,
6782 domain_nr, domain_nr,
6783 GFP_KERNEL);
6784 }
6785
6786 /*
6787 * If domain was not specified in DT, choose a free ID from dynamic
6788 * allocations. All domain numbers from DT are permanently in
6789 * dynamic allocations to prevent assigning them to other DT nodes
6790 * without static domain.
6791 */
6792 return ida_alloc(&pci_domain_nr_dynamic_ida, GFP_KERNEL);
6793}
6794
6795static void of_pci_bus_release_domain_nr(struct pci_bus *bus, struct device *parent)
6796{
6797 if (bus->domain_nr < 0)
6798 return;
6799
6800 /* Release domain from IDA where it was allocated. */
6801 if (of_get_pci_domain_nr(parent->of_node) == bus->domain_nr)
6802 ida_free(&pci_domain_nr_static_ida, bus->domain_nr);
6803 else
6804 ida_free(&pci_domain_nr_dynamic_ida, bus->domain_nr);
6805}
6806
6807int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent)
6808{
6809 return acpi_disabled ? of_pci_bus_find_domain_nr(parent) :
6810 acpi_pci_bus_find_domain_nr(bus);
6811}
6812
6813void pci_bus_release_domain_nr(struct pci_bus *bus, struct device *parent)
6814{
6815 if (!acpi_disabled)
6816 return;
6817 of_pci_bus_release_domain_nr(bus, parent);
6818}
6819#endif
6820
6821/**
6822 * pci_ext_cfg_avail - can we access extended PCI config space?
6823 *
6824 * Returns 1 if we can access PCI extended config space (offsets
6825 * greater than 0xff). This is the default implementation. Architecture
6826 * implementations can override this.
6827 */
6828int __weak pci_ext_cfg_avail(void)
6829{
6830 return 1;
6831}
6832
6833void __weak pci_fixup_cardbus(struct pci_bus *bus)
6834{
6835}
6836EXPORT_SYMBOL(pci_fixup_cardbus);
6837
6838static int __init pci_setup(char *str)
6839{
6840 while (str) {
6841 char *k = strchr(str, ',');
6842 if (k)
6843 *k++ = 0;
6844 if (*str && (str = pcibios_setup(str)) && *str) {
6845 if (!strcmp(str, "nomsi")) {
6846 pci_no_msi();
6847 } else if (!strncmp(str, "noats", 5)) {
6848 pr_info("PCIe: ATS is disabled\n");
6849 pcie_ats_disabled = true;
6850 } else if (!strcmp(str, "noaer")) {
6851 pci_no_aer();
6852 } else if (!strcmp(str, "earlydump")) {
6853 pci_early_dump = true;
6854 } else if (!strncmp(str, "realloc=", 8)) {
6855 pci_realloc_get_opt(str + 8);
6856 } else if (!strncmp(str, "realloc", 7)) {
6857 pci_realloc_get_opt("on");
6858 } else if (!strcmp(str, "nodomains")) {
6859 pci_no_domains();
6860 } else if (!strncmp(str, "noari", 5)) {
6861 pcie_ari_disabled = true;
6862 } else if (!strncmp(str, "cbiosize=", 9)) {
6863 pci_cardbus_io_size = memparse(str + 9, &str);
6864 } else if (!strncmp(str, "cbmemsize=", 10)) {
6865 pci_cardbus_mem_size = memparse(str + 10, &str);
6866 } else if (!strncmp(str, "resource_alignment=", 19)) {
6867 resource_alignment_param = str + 19;
6868 } else if (!strncmp(str, "ecrc=", 5)) {
6869 pcie_ecrc_get_policy(str + 5);
6870 } else if (!strncmp(str, "hpiosize=", 9)) {
6871 pci_hotplug_io_size = memparse(str + 9, &str);
6872 } else if (!strncmp(str, "hpmmiosize=", 11)) {
6873 pci_hotplug_mmio_size = memparse(str + 11, &str);
6874 } else if (!strncmp(str, "hpmmioprefsize=", 15)) {
6875 pci_hotplug_mmio_pref_size = memparse(str + 15, &str);
6876 } else if (!strncmp(str, "hpmemsize=", 10)) {
6877 pci_hotplug_mmio_size = memparse(str + 10, &str);
6878 pci_hotplug_mmio_pref_size = pci_hotplug_mmio_size;
6879 } else if (!strncmp(str, "hpbussize=", 10)) {
6880 pci_hotplug_bus_size =
6881 simple_strtoul(str + 10, &str, 0);
6882 if (pci_hotplug_bus_size > 0xff)
6883 pci_hotplug_bus_size = DEFAULT_HOTPLUG_BUS_SIZE;
6884 } else if (!strncmp(str, "pcie_bus_tune_off", 17)) {
6885 pcie_bus_config = PCIE_BUS_TUNE_OFF;
6886 } else if (!strncmp(str, "pcie_bus_safe", 13)) {
6887 pcie_bus_config = PCIE_BUS_SAFE;
6888 } else if (!strncmp(str, "pcie_bus_perf", 13)) {
6889 pcie_bus_config = PCIE_BUS_PERFORMANCE;
6890 } else if (!strncmp(str, "pcie_bus_peer2peer", 18)) {
6891 pcie_bus_config = PCIE_BUS_PEER2PEER;
6892 } else if (!strncmp(str, "pcie_scan_all", 13)) {
6893 pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS);
6894 } else if (!strncmp(str, "disable_acs_redir=", 18)) {
6895 disable_acs_redir_param = str + 18;
6896 } else {
6897 pr_err("PCI: Unknown option `%s'\n", str);
6898 }
6899 }
6900 str = k;
6901 }
6902 return 0;
6903}
6904early_param("pci", pci_setup);
6905
6906/*
6907 * 'resource_alignment_param' and 'disable_acs_redir_param' are initialized
6908 * in pci_setup(), above, to point to data in the __initdata section which
6909 * will be freed after the init sequence is complete. We can't allocate memory
6910 * in pci_setup() because some architectures do not have any memory allocation
6911 * service available during an early_param() call. So we allocate memory and
6912 * copy the variable here before the init section is freed.
6913 *
6914 */
6915static int __init pci_realloc_setup_params(void)
6916{
6917 resource_alignment_param = kstrdup(resource_alignment_param,
6918 GFP_KERNEL);
6919 disable_acs_redir_param = kstrdup(disable_acs_redir_param, GFP_KERNEL);
6920
6921 return 0;
6922}
6923pure_initcall(pci_realloc_setup_params);