xref: /linux/drivers/pci/pci.c (revision 54f5a57e266318d72f84fda95805099986a7e201)
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 <linux/pci_hotplug.h>
26 #include <asm-generic/pci-bridge.h>
27 #include <asm/setup.h>
28 #include "pci.h"
29 
30 const char *pci_power_names[] = {
31 	"error", "D0", "D1", "D2", "D3hot", "D3cold", "unknown",
32 };
33 EXPORT_SYMBOL_GPL(pci_power_names);
34 
35 int isa_dma_bridge_buggy;
36 EXPORT_SYMBOL(isa_dma_bridge_buggy);
37 
38 int pci_pci_problems;
39 EXPORT_SYMBOL(pci_pci_problems);
40 
41 unsigned int pci_pm_d3_delay;
42 
43 static void pci_pme_list_scan(struct work_struct *work);
44 
45 static LIST_HEAD(pci_pme_list);
46 static DEFINE_MUTEX(pci_pme_list_mutex);
47 static DECLARE_DELAYED_WORK(pci_pme_work, pci_pme_list_scan);
48 
49 struct pci_pme_device {
50 	struct list_head list;
51 	struct pci_dev *dev;
52 };
53 
54 #define PME_TIMEOUT 1000 /* How long between PME checks */
55 
56 static void pci_dev_d3_sleep(struct pci_dev *dev)
57 {
58 	unsigned int delay = dev->d3_delay;
59 
60 	if (delay < pci_pm_d3_delay)
61 		delay = pci_pm_d3_delay;
62 
63 	msleep(delay);
64 }
65 
66 #ifdef CONFIG_PCI_DOMAINS
67 int pci_domains_supported = 1;
68 #endif
69 
70 #define DEFAULT_CARDBUS_IO_SIZE		(256)
71 #define DEFAULT_CARDBUS_MEM_SIZE	(64*1024*1024)
72 /* pci=cbmemsize=nnM,cbiosize=nn can override this */
73 unsigned long pci_cardbus_io_size = DEFAULT_CARDBUS_IO_SIZE;
74 unsigned long pci_cardbus_mem_size = DEFAULT_CARDBUS_MEM_SIZE;
75 
76 #define DEFAULT_HOTPLUG_IO_SIZE		(256)
77 #define DEFAULT_HOTPLUG_MEM_SIZE	(2*1024*1024)
78 /* pci=hpmemsize=nnM,hpiosize=nn can override this */
79 unsigned long pci_hotplug_io_size  = DEFAULT_HOTPLUG_IO_SIZE;
80 unsigned long pci_hotplug_mem_size = DEFAULT_HOTPLUG_MEM_SIZE;
81 
82 enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_TUNE_OFF;
83 
84 /*
85  * The default CLS is used if arch didn't set CLS explicitly and not
86  * all pci devices agree on the same value.  Arch can override either
87  * the dfl or actual value as it sees fit.  Don't forget this is
88  * measured in 32-bit words, not bytes.
89  */
90 u8 pci_dfl_cache_line_size = L1_CACHE_BYTES >> 2;
91 u8 pci_cache_line_size;
92 
93 /*
94  * If we set up a device for bus mastering, we need to check the latency
95  * timer as certain BIOSes forget to set it properly.
96  */
97 unsigned int pcibios_max_latency = 255;
98 
99 /* If set, the PCIe ARI capability will not be used. */
100 static bool pcie_ari_disabled;
101 
102 /**
103  * pci_bus_max_busnr - returns maximum PCI bus number of given bus' children
104  * @bus: pointer to PCI bus structure to search
105  *
106  * Given a PCI bus, returns the highest PCI bus number present in the set
107  * including the given PCI bus and its list of child PCI buses.
108  */
109 unsigned char pci_bus_max_busnr(struct pci_bus* bus)
110 {
111 	struct list_head *tmp;
112 	unsigned char max, n;
113 
114 	max = bus->busn_res.end;
115 	list_for_each(tmp, &bus->children) {
116 		n = pci_bus_max_busnr(pci_bus_b(tmp));
117 		if(n > max)
118 			max = n;
119 	}
120 	return max;
121 }
122 EXPORT_SYMBOL_GPL(pci_bus_max_busnr);
123 
124 #ifdef CONFIG_HAS_IOMEM
125 void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar)
126 {
127 	/*
128 	 * Make sure the BAR is actually a memory resource, not an IO resource
129 	 */
130 	if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM)) {
131 		WARN_ON(1);
132 		return NULL;
133 	}
134 	return ioremap_nocache(pci_resource_start(pdev, bar),
135 				     pci_resource_len(pdev, bar));
136 }
137 EXPORT_SYMBOL_GPL(pci_ioremap_bar);
138 #endif
139 
140 #define PCI_FIND_CAP_TTL	48
141 
142 static int __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn,
143 				   u8 pos, int cap, int *ttl)
144 {
145 	u8 id;
146 
147 	while ((*ttl)--) {
148 		pci_bus_read_config_byte(bus, devfn, pos, &pos);
149 		if (pos < 0x40)
150 			break;
151 		pos &= ~3;
152 		pci_bus_read_config_byte(bus, devfn, pos + PCI_CAP_LIST_ID,
153 					 &id);
154 		if (id == 0xff)
155 			break;
156 		if (id == cap)
157 			return pos;
158 		pos += PCI_CAP_LIST_NEXT;
159 	}
160 	return 0;
161 }
162 
163 static int __pci_find_next_cap(struct pci_bus *bus, unsigned int devfn,
164 			       u8 pos, int cap)
165 {
166 	int ttl = PCI_FIND_CAP_TTL;
167 
168 	return __pci_find_next_cap_ttl(bus, devfn, pos, cap, &ttl);
169 }
170 
171 int pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap)
172 {
173 	return __pci_find_next_cap(dev->bus, dev->devfn,
174 				   pos + PCI_CAP_LIST_NEXT, cap);
175 }
176 EXPORT_SYMBOL_GPL(pci_find_next_capability);
177 
178 static int __pci_bus_find_cap_start(struct pci_bus *bus,
179 				    unsigned int devfn, u8 hdr_type)
180 {
181 	u16 status;
182 
183 	pci_bus_read_config_word(bus, devfn, PCI_STATUS, &status);
184 	if (!(status & PCI_STATUS_CAP_LIST))
185 		return 0;
186 
187 	switch (hdr_type) {
188 	case PCI_HEADER_TYPE_NORMAL:
189 	case PCI_HEADER_TYPE_BRIDGE:
190 		return PCI_CAPABILITY_LIST;
191 	case PCI_HEADER_TYPE_CARDBUS:
192 		return PCI_CB_CAPABILITY_LIST;
193 	default:
194 		return 0;
195 	}
196 
197 	return 0;
198 }
199 
200 /**
201  * pci_find_capability - query for devices' capabilities
202  * @dev: PCI device to query
203  * @cap: capability code
204  *
205  * Tell if a device supports a given PCI capability.
206  * Returns the address of the requested capability structure within the
207  * device's PCI configuration space or 0 in case the device does not
208  * support it.  Possible values for @cap:
209  *
210  *  %PCI_CAP_ID_PM           Power Management
211  *  %PCI_CAP_ID_AGP          Accelerated Graphics Port
212  *  %PCI_CAP_ID_VPD          Vital Product Data
213  *  %PCI_CAP_ID_SLOTID       Slot Identification
214  *  %PCI_CAP_ID_MSI          Message Signalled Interrupts
215  *  %PCI_CAP_ID_CHSWP        CompactPCI HotSwap
216  *  %PCI_CAP_ID_PCIX         PCI-X
217  *  %PCI_CAP_ID_EXP          PCI Express
218  */
219 int pci_find_capability(struct pci_dev *dev, int cap)
220 {
221 	int pos;
222 
223 	pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);
224 	if (pos)
225 		pos = __pci_find_next_cap(dev->bus, dev->devfn, pos, cap);
226 
227 	return pos;
228 }
229 
230 /**
231  * pci_bus_find_capability - query for devices' capabilities
232  * @bus:   the PCI bus to query
233  * @devfn: PCI device to query
234  * @cap:   capability code
235  *
236  * Like pci_find_capability() but works for pci devices that do not have a
237  * pci_dev structure set up yet.
238  *
239  * Returns the address of the requested capability structure within the
240  * device's PCI configuration space or 0 in case the device does not
241  * support it.
242  */
243 int pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap)
244 {
245 	int pos;
246 	u8 hdr_type;
247 
248 	pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &hdr_type);
249 
250 	pos = __pci_bus_find_cap_start(bus, devfn, hdr_type & 0x7f);
251 	if (pos)
252 		pos = __pci_find_next_cap(bus, devfn, pos, cap);
253 
254 	return pos;
255 }
256 
257 /**
258  * pci_find_next_ext_capability - Find an extended capability
259  * @dev: PCI device to query
260  * @start: address at which to start looking (0 to start at beginning of list)
261  * @cap: capability code
262  *
263  * Returns the address of the next matching extended capability structure
264  * within the device's PCI configuration space or 0 if the device does
265  * not support it.  Some capabilities can occur several times, e.g., the
266  * vendor-specific capability, and this provides a way to find them all.
267  */
268 int pci_find_next_ext_capability(struct pci_dev *dev, int start, int cap)
269 {
270 	u32 header;
271 	int ttl;
272 	int pos = PCI_CFG_SPACE_SIZE;
273 
274 	/* minimum 8 bytes per capability */
275 	ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8;
276 
277 	if (dev->cfg_size <= PCI_CFG_SPACE_SIZE)
278 		return 0;
279 
280 	if (start)
281 		pos = start;
282 
283 	if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
284 		return 0;
285 
286 	/*
287 	 * If we have no capabilities, this is indicated by cap ID,
288 	 * cap version and next pointer all being 0.
289 	 */
290 	if (header == 0)
291 		return 0;
292 
293 	while (ttl-- > 0) {
294 		if (PCI_EXT_CAP_ID(header) == cap && pos != start)
295 			return pos;
296 
297 		pos = PCI_EXT_CAP_NEXT(header);
298 		if (pos < PCI_CFG_SPACE_SIZE)
299 			break;
300 
301 		if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
302 			break;
303 	}
304 
305 	return 0;
306 }
307 EXPORT_SYMBOL_GPL(pci_find_next_ext_capability);
308 
309 /**
310  * pci_find_ext_capability - Find an extended capability
311  * @dev: PCI device to query
312  * @cap: capability code
313  *
314  * Returns the address of the requested extended capability structure
315  * within the device's PCI configuration space or 0 if the device does
316  * not support it.  Possible values for @cap:
317  *
318  *  %PCI_EXT_CAP_ID_ERR		Advanced Error Reporting
319  *  %PCI_EXT_CAP_ID_VC		Virtual Channel
320  *  %PCI_EXT_CAP_ID_DSN		Device Serial Number
321  *  %PCI_EXT_CAP_ID_PWR		Power Budgeting
322  */
323 int pci_find_ext_capability(struct pci_dev *dev, int cap)
324 {
325 	return pci_find_next_ext_capability(dev, 0, cap);
326 }
327 EXPORT_SYMBOL_GPL(pci_find_ext_capability);
328 
329 static int __pci_find_next_ht_cap(struct pci_dev *dev, int pos, int ht_cap)
330 {
331 	int rc, ttl = PCI_FIND_CAP_TTL;
332 	u8 cap, mask;
333 
334 	if (ht_cap == HT_CAPTYPE_SLAVE || ht_cap == HT_CAPTYPE_HOST)
335 		mask = HT_3BIT_CAP_MASK;
336 	else
337 		mask = HT_5BIT_CAP_MASK;
338 
339 	pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn, pos,
340 				      PCI_CAP_ID_HT, &ttl);
341 	while (pos) {
342 		rc = pci_read_config_byte(dev, pos + 3, &cap);
343 		if (rc != PCIBIOS_SUCCESSFUL)
344 			return 0;
345 
346 		if ((cap & mask) == ht_cap)
347 			return pos;
348 
349 		pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn,
350 					      pos + PCI_CAP_LIST_NEXT,
351 					      PCI_CAP_ID_HT, &ttl);
352 	}
353 
354 	return 0;
355 }
356 /**
357  * pci_find_next_ht_capability - query a device's Hypertransport capabilities
358  * @dev: PCI device to query
359  * @pos: Position from which to continue searching
360  * @ht_cap: Hypertransport capability code
361  *
362  * To be used in conjunction with pci_find_ht_capability() to search for
363  * all capabilities matching @ht_cap. @pos should always be a value returned
364  * from pci_find_ht_capability().
365  *
366  * NB. To be 100% safe against broken PCI devices, the caller should take
367  * steps to avoid an infinite loop.
368  */
369 int pci_find_next_ht_capability(struct pci_dev *dev, int pos, int ht_cap)
370 {
371 	return __pci_find_next_ht_cap(dev, pos + PCI_CAP_LIST_NEXT, ht_cap);
372 }
373 EXPORT_SYMBOL_GPL(pci_find_next_ht_capability);
374 
375 /**
376  * pci_find_ht_capability - query a device's Hypertransport capabilities
377  * @dev: PCI device to query
378  * @ht_cap: Hypertransport capability code
379  *
380  * Tell if a device supports a given Hypertransport capability.
381  * Returns an address within the device's PCI configuration space
382  * or 0 in case the device does not support the request capability.
383  * The address points to the PCI capability, of type PCI_CAP_ID_HT,
384  * which has a Hypertransport capability matching @ht_cap.
385  */
386 int pci_find_ht_capability(struct pci_dev *dev, int ht_cap)
387 {
388 	int pos;
389 
390 	pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);
391 	if (pos)
392 		pos = __pci_find_next_ht_cap(dev, pos, ht_cap);
393 
394 	return pos;
395 }
396 EXPORT_SYMBOL_GPL(pci_find_ht_capability);
397 
398 /**
399  * pci_find_parent_resource - return resource region of parent bus of given region
400  * @dev: PCI device structure contains resources to be searched
401  * @res: child resource record for which parent is sought
402  *
403  *  For given resource region of given device, return the resource
404  *  region of parent bus the given region is contained in or where
405  *  it should be allocated from.
406  */
407 struct resource *
408 pci_find_parent_resource(const struct pci_dev *dev, struct resource *res)
409 {
410 	const struct pci_bus *bus = dev->bus;
411 	int i;
412 	struct resource *best = NULL, *r;
413 
414 	pci_bus_for_each_resource(bus, r, i) {
415 		if (!r)
416 			continue;
417 		if (res->start && !(res->start >= r->start && res->end <= r->end))
418 			continue;	/* Not contained */
419 		if ((res->flags ^ r->flags) & (IORESOURCE_IO | IORESOURCE_MEM))
420 			continue;	/* Wrong type */
421 		if (!((res->flags ^ r->flags) & IORESOURCE_PREFETCH))
422 			return r;	/* Exact match */
423 		/* We can't insert a non-prefetch resource inside a prefetchable parent .. */
424 		if (r->flags & IORESOURCE_PREFETCH)
425 			continue;
426 		/* .. but we can put a prefetchable resource inside a non-prefetchable one */
427 		if (!best)
428 			best = r;
429 	}
430 	return best;
431 }
432 
433 /**
434  * pci_wait_for_pending - wait for @mask bit(s) to clear in status word @pos
435  * @dev: the PCI device to operate on
436  * @pos: config space offset of status word
437  * @mask: mask of bit(s) to care about in status word
438  *
439  * Return 1 when mask bit(s) in status word clear, 0 otherwise.
440  */
441 int pci_wait_for_pending(struct pci_dev *dev, int pos, u16 mask)
442 {
443 	int i;
444 
445 	/* Wait for Transaction Pending bit clean */
446 	for (i = 0; i < 4; i++) {
447 		u16 status;
448 		if (i)
449 			msleep((1 << (i - 1)) * 100);
450 
451 		pci_read_config_word(dev, pos, &status);
452 		if (!(status & mask))
453 			return 1;
454 	}
455 
456 	return 0;
457 }
458 
459 /**
460  * pci_restore_bars - restore a devices BAR values (e.g. after wake-up)
461  * @dev: PCI device to have its BARs restored
462  *
463  * Restore the BAR values for a given device, so as to make it
464  * accessible by its driver.
465  */
466 static void
467 pci_restore_bars(struct pci_dev *dev)
468 {
469 	int i;
470 
471 	for (i = 0; i < PCI_BRIDGE_RESOURCES; i++)
472 		pci_update_resource(dev, i);
473 }
474 
475 static struct pci_platform_pm_ops *pci_platform_pm;
476 
477 int pci_set_platform_pm(struct pci_platform_pm_ops *ops)
478 {
479 	if (!ops->is_manageable || !ops->set_state || !ops->choose_state
480 	    || !ops->sleep_wake)
481 		return -EINVAL;
482 	pci_platform_pm = ops;
483 	return 0;
484 }
485 
486 static inline bool platform_pci_power_manageable(struct pci_dev *dev)
487 {
488 	return pci_platform_pm ? pci_platform_pm->is_manageable(dev) : false;
489 }
490 
491 static inline int platform_pci_set_power_state(struct pci_dev *dev,
492                                                 pci_power_t t)
493 {
494 	return pci_platform_pm ? pci_platform_pm->set_state(dev, t) : -ENOSYS;
495 }
496 
497 static inline pci_power_t platform_pci_choose_state(struct pci_dev *dev)
498 {
499 	return pci_platform_pm ?
500 			pci_platform_pm->choose_state(dev) : PCI_POWER_ERROR;
501 }
502 
503 static inline int platform_pci_sleep_wake(struct pci_dev *dev, bool enable)
504 {
505 	return pci_platform_pm ?
506 			pci_platform_pm->sleep_wake(dev, enable) : -ENODEV;
507 }
508 
509 static inline int platform_pci_run_wake(struct pci_dev *dev, bool enable)
510 {
511 	return pci_platform_pm ?
512 			pci_platform_pm->run_wake(dev, enable) : -ENODEV;
513 }
514 
515 /**
516  * pci_raw_set_power_state - Use PCI PM registers to set the power state of
517  *                           given PCI device
518  * @dev: PCI device to handle.
519  * @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
520  *
521  * RETURN VALUE:
522  * -EINVAL if the requested state is invalid.
523  * -EIO if device does not support PCI PM or its PM capabilities register has a
524  * wrong version, or device doesn't support the requested state.
525  * 0 if device already is in the requested state.
526  * 0 if device's power state has been successfully changed.
527  */
528 static int pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
529 {
530 	u16 pmcsr;
531 	bool need_restore = false;
532 
533 	/* Check if we're already there */
534 	if (dev->current_state == state)
535 		return 0;
536 
537 	if (!dev->pm_cap)
538 		return -EIO;
539 
540 	if (state < PCI_D0 || state > PCI_D3hot)
541 		return -EINVAL;
542 
543 	/* Validate current state:
544 	 * Can enter D0 from any state, but if we can only go deeper
545 	 * to sleep if we're already in a low power state
546 	 */
547 	if (state != PCI_D0 && dev->current_state <= PCI_D3cold
548 	    && dev->current_state > state) {
549 		dev_err(&dev->dev, "invalid power transition "
550 			"(from state %d to %d)\n", dev->current_state, state);
551 		return -EINVAL;
552 	}
553 
554 	/* check if this device supports the desired state */
555 	if ((state == PCI_D1 && !dev->d1_support)
556 	   || (state == PCI_D2 && !dev->d2_support))
557 		return -EIO;
558 
559 	pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
560 
561 	/* If we're (effectively) in D3, force entire word to 0.
562 	 * This doesn't affect PME_Status, disables PME_En, and
563 	 * sets PowerState to 0.
564 	 */
565 	switch (dev->current_state) {
566 	case PCI_D0:
567 	case PCI_D1:
568 	case PCI_D2:
569 		pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
570 		pmcsr |= state;
571 		break;
572 	case PCI_D3hot:
573 	case PCI_D3cold:
574 	case PCI_UNKNOWN: /* Boot-up */
575 		if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot
576 		 && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))
577 			need_restore = true;
578 		/* Fall-through: force to D0 */
579 	default:
580 		pmcsr = 0;
581 		break;
582 	}
583 
584 	/* enter specified state */
585 	pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
586 
587 	/* Mandatory power management transition delays */
588 	/* see PCI PM 1.1 5.6.1 table 18 */
589 	if (state == PCI_D3hot || dev->current_state == PCI_D3hot)
590 		pci_dev_d3_sleep(dev);
591 	else if (state == PCI_D2 || dev->current_state == PCI_D2)
592 		udelay(PCI_PM_D2_DELAY);
593 
594 	pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
595 	dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
596 	if (dev->current_state != state && printk_ratelimit())
597 		dev_info(&dev->dev, "Refused to change power state, "
598 			"currently in D%d\n", dev->current_state);
599 
600 	/*
601 	 * According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT
602 	 * INTERFACE SPECIFICATION, REV. 1.2", a device transitioning
603 	 * from D3hot to D0 _may_ perform an internal reset, thereby
604 	 * going to "D0 Uninitialized" rather than "D0 Initialized".
605 	 * For example, at least some versions of the 3c905B and the
606 	 * 3c556B exhibit this behaviour.
607 	 *
608 	 * At least some laptop BIOSen (e.g. the Thinkpad T21) leave
609 	 * devices in a D3hot state at boot.  Consequently, we need to
610 	 * restore at least the BARs so that the device will be
611 	 * accessible to its driver.
612 	 */
613 	if (need_restore)
614 		pci_restore_bars(dev);
615 
616 	if (dev->bus->self)
617 		pcie_aspm_pm_state_change(dev->bus->self);
618 
619 	return 0;
620 }
621 
622 /**
623  * pci_update_current_state - Read PCI power state of given device from its
624  *                            PCI PM registers and cache it
625  * @dev: PCI device to handle.
626  * @state: State to cache in case the device doesn't have the PM capability
627  */
628 void pci_update_current_state(struct pci_dev *dev, pci_power_t state)
629 {
630 	if (dev->pm_cap) {
631 		u16 pmcsr;
632 
633 		/*
634 		 * Configuration space is not accessible for device in
635 		 * D3cold, so just keep or set D3cold for safety
636 		 */
637 		if (dev->current_state == PCI_D3cold)
638 			return;
639 		if (state == PCI_D3cold) {
640 			dev->current_state = PCI_D3cold;
641 			return;
642 		}
643 		pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
644 		dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
645 	} else {
646 		dev->current_state = state;
647 	}
648 }
649 
650 /**
651  * pci_power_up - Put the given device into D0 forcibly
652  * @dev: PCI device to power up
653  */
654 void pci_power_up(struct pci_dev *dev)
655 {
656 	if (platform_pci_power_manageable(dev))
657 		platform_pci_set_power_state(dev, PCI_D0);
658 
659 	pci_raw_set_power_state(dev, PCI_D0);
660 	pci_update_current_state(dev, PCI_D0);
661 }
662 
663 /**
664  * pci_platform_power_transition - Use platform to change device power state
665  * @dev: PCI device to handle.
666  * @state: State to put the device into.
667  */
668 static int pci_platform_power_transition(struct pci_dev *dev, pci_power_t state)
669 {
670 	int error;
671 
672 	if (platform_pci_power_manageable(dev)) {
673 		error = platform_pci_set_power_state(dev, state);
674 		if (!error)
675 			pci_update_current_state(dev, state);
676 	} else
677 		error = -ENODEV;
678 
679 	if (error && !dev->pm_cap) /* Fall back to PCI_D0 */
680 		dev->current_state = PCI_D0;
681 
682 	return error;
683 }
684 
685 /**
686  * pci_wakeup - Wake up a PCI device
687  * @pci_dev: Device to handle.
688  * @ign: ignored parameter
689  */
690 static int pci_wakeup(struct pci_dev *pci_dev, void *ign)
691 {
692 	pci_wakeup_event(pci_dev);
693 	pm_request_resume(&pci_dev->dev);
694 	return 0;
695 }
696 
697 /**
698  * pci_wakeup_bus - Walk given bus and wake up devices on it
699  * @bus: Top bus of the subtree to walk.
700  */
701 static void pci_wakeup_bus(struct pci_bus *bus)
702 {
703 	if (bus)
704 		pci_walk_bus(bus, pci_wakeup, NULL);
705 }
706 
707 /**
708  * __pci_start_power_transition - Start power transition of a PCI device
709  * @dev: PCI device to handle.
710  * @state: State to put the device into.
711  */
712 static void __pci_start_power_transition(struct pci_dev *dev, pci_power_t state)
713 {
714 	if (state == PCI_D0) {
715 		pci_platform_power_transition(dev, PCI_D0);
716 		/*
717 		 * Mandatory power management transition delays, see
718 		 * PCI Express Base Specification Revision 2.0 Section
719 		 * 6.6.1: Conventional Reset.  Do not delay for
720 		 * devices powered on/off by corresponding bridge,
721 		 * because have already delayed for the bridge.
722 		 */
723 		if (dev->runtime_d3cold) {
724 			msleep(dev->d3cold_delay);
725 			/*
726 			 * When powering on a bridge from D3cold, the
727 			 * whole hierarchy may be powered on into
728 			 * D0uninitialized state, resume them to give
729 			 * them a chance to suspend again
730 			 */
731 			pci_wakeup_bus(dev->subordinate);
732 		}
733 	}
734 }
735 
736 /**
737  * __pci_dev_set_current_state - Set current state of a PCI device
738  * @dev: Device to handle
739  * @data: pointer to state to be set
740  */
741 static int __pci_dev_set_current_state(struct pci_dev *dev, void *data)
742 {
743 	pci_power_t state = *(pci_power_t *)data;
744 
745 	dev->current_state = state;
746 	return 0;
747 }
748 
749 /**
750  * __pci_bus_set_current_state - Walk given bus and set current state of devices
751  * @bus: Top bus of the subtree to walk.
752  * @state: state to be set
753  */
754 static void __pci_bus_set_current_state(struct pci_bus *bus, pci_power_t state)
755 {
756 	if (bus)
757 		pci_walk_bus(bus, __pci_dev_set_current_state, &state);
758 }
759 
760 /**
761  * __pci_complete_power_transition - Complete power transition of a PCI device
762  * @dev: PCI device to handle.
763  * @state: State to put the device into.
764  *
765  * This function should not be called directly by device drivers.
766  */
767 int __pci_complete_power_transition(struct pci_dev *dev, pci_power_t state)
768 {
769 	int ret;
770 
771 	if (state <= PCI_D0)
772 		return -EINVAL;
773 	ret = pci_platform_power_transition(dev, state);
774 	/* Power off the bridge may power off the whole hierarchy */
775 	if (!ret && state == PCI_D3cold)
776 		__pci_bus_set_current_state(dev->subordinate, PCI_D3cold);
777 	return ret;
778 }
779 EXPORT_SYMBOL_GPL(__pci_complete_power_transition);
780 
781 /**
782  * pci_set_power_state - Set the power state of a PCI device
783  * @dev: PCI device to handle.
784  * @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
785  *
786  * Transition a device to a new power state, using the platform firmware and/or
787  * the device's PCI PM registers.
788  *
789  * RETURN VALUE:
790  * -EINVAL if the requested state is invalid.
791  * -EIO if device does not support PCI PM or its PM capabilities register has a
792  * wrong version, or device doesn't support the requested state.
793  * 0 if device already is in the requested state.
794  * 0 if device's power state has been successfully changed.
795  */
796 int pci_set_power_state(struct pci_dev *dev, pci_power_t state)
797 {
798 	int error;
799 
800 	/* bound the state we're entering */
801 	if (state > PCI_D3cold)
802 		state = PCI_D3cold;
803 	else if (state < PCI_D0)
804 		state = PCI_D0;
805 	else if ((state == PCI_D1 || state == PCI_D2) && pci_no_d1d2(dev))
806 		/*
807 		 * If the device or the parent bridge do not support PCI PM,
808 		 * ignore the request if we're doing anything other than putting
809 		 * it into D0 (which would only happen on boot).
810 		 */
811 		return 0;
812 
813 	/* Check if we're already there */
814 	if (dev->current_state == state)
815 		return 0;
816 
817 	__pci_start_power_transition(dev, state);
818 
819 	/* This device is quirked not to be put into D3, so
820 	   don't put it in D3 */
821 	if (state >= PCI_D3hot && (dev->dev_flags & PCI_DEV_FLAGS_NO_D3))
822 		return 0;
823 
824 	/*
825 	 * To put device in D3cold, we put device into D3hot in native
826 	 * way, then put device into D3cold with platform ops
827 	 */
828 	error = pci_raw_set_power_state(dev, state > PCI_D3hot ?
829 					PCI_D3hot : state);
830 
831 	if (!__pci_complete_power_transition(dev, state))
832 		error = 0;
833 	/*
834 	 * When aspm_policy is "powersave" this call ensures
835 	 * that ASPM is configured.
836 	 */
837 	if (!error && dev->bus->self)
838 		pcie_aspm_powersave_config_link(dev->bus->self);
839 
840 	return error;
841 }
842 
843 /**
844  * pci_choose_state - Choose the power state of a PCI device
845  * @dev: PCI device to be suspended
846  * @state: target sleep state for the whole system. This is the value
847  *	that is passed to suspend() function.
848  *
849  * Returns PCI power state suitable for given device and given system
850  * message.
851  */
852 
853 pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state)
854 {
855 	pci_power_t ret;
856 
857 	if (!dev->pm_cap)
858 		return PCI_D0;
859 
860 	ret = platform_pci_choose_state(dev);
861 	if (ret != PCI_POWER_ERROR)
862 		return ret;
863 
864 	switch (state.event) {
865 	case PM_EVENT_ON:
866 		return PCI_D0;
867 	case PM_EVENT_FREEZE:
868 	case PM_EVENT_PRETHAW:
869 		/* REVISIT both freeze and pre-thaw "should" use D0 */
870 	case PM_EVENT_SUSPEND:
871 	case PM_EVENT_HIBERNATE:
872 		return PCI_D3hot;
873 	default:
874 		dev_info(&dev->dev, "unrecognized suspend event %d\n",
875 			 state.event);
876 		BUG();
877 	}
878 	return PCI_D0;
879 }
880 
881 EXPORT_SYMBOL(pci_choose_state);
882 
883 #define PCI_EXP_SAVE_REGS	7
884 
885 
886 static struct pci_cap_saved_state *_pci_find_saved_cap(struct pci_dev *pci_dev,
887 						       u16 cap, bool extended)
888 {
889 	struct pci_cap_saved_state *tmp;
890 
891 	hlist_for_each_entry(tmp, &pci_dev->saved_cap_space, next) {
892 		if (tmp->cap.cap_extended == extended && tmp->cap.cap_nr == cap)
893 			return tmp;
894 	}
895 	return NULL;
896 }
897 
898 struct pci_cap_saved_state *pci_find_saved_cap(struct pci_dev *dev, char cap)
899 {
900 	return _pci_find_saved_cap(dev, cap, false);
901 }
902 
903 struct pci_cap_saved_state *pci_find_saved_ext_cap(struct pci_dev *dev, u16 cap)
904 {
905 	return _pci_find_saved_cap(dev, cap, true);
906 }
907 
908 static int pci_save_pcie_state(struct pci_dev *dev)
909 {
910 	int i = 0;
911 	struct pci_cap_saved_state *save_state;
912 	u16 *cap;
913 
914 	if (!pci_is_pcie(dev))
915 		return 0;
916 
917 	save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
918 	if (!save_state) {
919 		dev_err(&dev->dev, "buffer not found in %s\n", __func__);
920 		return -ENOMEM;
921 	}
922 
923 	cap = (u16 *)&save_state->cap.data[0];
924 	pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &cap[i++]);
925 	pcie_capability_read_word(dev, PCI_EXP_LNKCTL, &cap[i++]);
926 	pcie_capability_read_word(dev, PCI_EXP_SLTCTL, &cap[i++]);
927 	pcie_capability_read_word(dev, PCI_EXP_RTCTL,  &cap[i++]);
928 	pcie_capability_read_word(dev, PCI_EXP_DEVCTL2, &cap[i++]);
929 	pcie_capability_read_word(dev, PCI_EXP_LNKCTL2, &cap[i++]);
930 	pcie_capability_read_word(dev, PCI_EXP_SLTCTL2, &cap[i++]);
931 
932 	return 0;
933 }
934 
935 static void pci_restore_pcie_state(struct pci_dev *dev)
936 {
937 	int i = 0;
938 	struct pci_cap_saved_state *save_state;
939 	u16 *cap;
940 
941 	save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
942 	if (!save_state)
943 		return;
944 
945 	cap = (u16 *)&save_state->cap.data[0];
946 	pcie_capability_write_word(dev, PCI_EXP_DEVCTL, cap[i++]);
947 	pcie_capability_write_word(dev, PCI_EXP_LNKCTL, cap[i++]);
948 	pcie_capability_write_word(dev, PCI_EXP_SLTCTL, cap[i++]);
949 	pcie_capability_write_word(dev, PCI_EXP_RTCTL, cap[i++]);
950 	pcie_capability_write_word(dev, PCI_EXP_DEVCTL2, cap[i++]);
951 	pcie_capability_write_word(dev, PCI_EXP_LNKCTL2, cap[i++]);
952 	pcie_capability_write_word(dev, PCI_EXP_SLTCTL2, cap[i++]);
953 }
954 
955 
956 static int pci_save_pcix_state(struct pci_dev *dev)
957 {
958 	int pos;
959 	struct pci_cap_saved_state *save_state;
960 
961 	pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
962 	if (pos <= 0)
963 		return 0;
964 
965 	save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX);
966 	if (!save_state) {
967 		dev_err(&dev->dev, "buffer not found in %s\n", __func__);
968 		return -ENOMEM;
969 	}
970 
971 	pci_read_config_word(dev, pos + PCI_X_CMD,
972 			     (u16 *)save_state->cap.data);
973 
974 	return 0;
975 }
976 
977 static void pci_restore_pcix_state(struct pci_dev *dev)
978 {
979 	int i = 0, pos;
980 	struct pci_cap_saved_state *save_state;
981 	u16 *cap;
982 
983 	save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX);
984 	pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
985 	if (!save_state || pos <= 0)
986 		return;
987 	cap = (u16 *)&save_state->cap.data[0];
988 
989 	pci_write_config_word(dev, pos + PCI_X_CMD, cap[i++]);
990 }
991 
992 
993 /**
994  * pci_save_state - save the PCI configuration space of a device before suspending
995  * @dev: - PCI device that we're dealing with
996  */
997 int
998 pci_save_state(struct pci_dev *dev)
999 {
1000 	int i;
1001 	/* XXX: 100% dword access ok here? */
1002 	for (i = 0; i < 16; i++)
1003 		pci_read_config_dword(dev, i * 4, &dev->saved_config_space[i]);
1004 	dev->state_saved = true;
1005 	if ((i = pci_save_pcie_state(dev)) != 0)
1006 		return i;
1007 	if ((i = pci_save_pcix_state(dev)) != 0)
1008 		return i;
1009 	if ((i = pci_save_vc_state(dev)) != 0)
1010 		return i;
1011 	return 0;
1012 }
1013 
1014 static void pci_restore_config_dword(struct pci_dev *pdev, int offset,
1015 				     u32 saved_val, int retry)
1016 {
1017 	u32 val;
1018 
1019 	pci_read_config_dword(pdev, offset, &val);
1020 	if (val == saved_val)
1021 		return;
1022 
1023 	for (;;) {
1024 		dev_dbg(&pdev->dev, "restoring config space at offset "
1025 			"%#x (was %#x, writing %#x)\n", offset, val, saved_val);
1026 		pci_write_config_dword(pdev, offset, saved_val);
1027 		if (retry-- <= 0)
1028 			return;
1029 
1030 		pci_read_config_dword(pdev, offset, &val);
1031 		if (val == saved_val)
1032 			return;
1033 
1034 		mdelay(1);
1035 	}
1036 }
1037 
1038 static void pci_restore_config_space_range(struct pci_dev *pdev,
1039 					   int start, int end, int retry)
1040 {
1041 	int index;
1042 
1043 	for (index = end; index >= start; index--)
1044 		pci_restore_config_dword(pdev, 4 * index,
1045 					 pdev->saved_config_space[index],
1046 					 retry);
1047 }
1048 
1049 static void pci_restore_config_space(struct pci_dev *pdev)
1050 {
1051 	if (pdev->hdr_type == PCI_HEADER_TYPE_NORMAL) {
1052 		pci_restore_config_space_range(pdev, 10, 15, 0);
1053 		/* Restore BARs before the command register. */
1054 		pci_restore_config_space_range(pdev, 4, 9, 10);
1055 		pci_restore_config_space_range(pdev, 0, 3, 0);
1056 	} else {
1057 		pci_restore_config_space_range(pdev, 0, 15, 0);
1058 	}
1059 }
1060 
1061 /**
1062  * pci_restore_state - Restore the saved state of a PCI device
1063  * @dev: - PCI device that we're dealing with
1064  */
1065 void pci_restore_state(struct pci_dev *dev)
1066 {
1067 	if (!dev->state_saved)
1068 		return;
1069 
1070 	/* PCI Express register must be restored first */
1071 	pci_restore_pcie_state(dev);
1072 	pci_restore_ats_state(dev);
1073 	pci_restore_vc_state(dev);
1074 
1075 	pci_restore_config_space(dev);
1076 
1077 	pci_restore_pcix_state(dev);
1078 	pci_restore_msi_state(dev);
1079 	pci_restore_iov_state(dev);
1080 
1081 	dev->state_saved = false;
1082 }
1083 
1084 struct pci_saved_state {
1085 	u32 config_space[16];
1086 	struct pci_cap_saved_data cap[0];
1087 };
1088 
1089 /**
1090  * pci_store_saved_state - Allocate and return an opaque struct containing
1091  *			   the device saved state.
1092  * @dev: PCI device that we're dealing with
1093  *
1094  * Return NULL if no state or error.
1095  */
1096 struct pci_saved_state *pci_store_saved_state(struct pci_dev *dev)
1097 {
1098 	struct pci_saved_state *state;
1099 	struct pci_cap_saved_state *tmp;
1100 	struct pci_cap_saved_data *cap;
1101 	size_t size;
1102 
1103 	if (!dev->state_saved)
1104 		return NULL;
1105 
1106 	size = sizeof(*state) + sizeof(struct pci_cap_saved_data);
1107 
1108 	hlist_for_each_entry(tmp, &dev->saved_cap_space, next)
1109 		size += sizeof(struct pci_cap_saved_data) + tmp->cap.size;
1110 
1111 	state = kzalloc(size, GFP_KERNEL);
1112 	if (!state)
1113 		return NULL;
1114 
1115 	memcpy(state->config_space, dev->saved_config_space,
1116 	       sizeof(state->config_space));
1117 
1118 	cap = state->cap;
1119 	hlist_for_each_entry(tmp, &dev->saved_cap_space, next) {
1120 		size_t len = sizeof(struct pci_cap_saved_data) + tmp->cap.size;
1121 		memcpy(cap, &tmp->cap, len);
1122 		cap = (struct pci_cap_saved_data *)((u8 *)cap + len);
1123 	}
1124 	/* Empty cap_save terminates list */
1125 
1126 	return state;
1127 }
1128 EXPORT_SYMBOL_GPL(pci_store_saved_state);
1129 
1130 /**
1131  * pci_load_saved_state - Reload the provided save state into struct pci_dev.
1132  * @dev: PCI device that we're dealing with
1133  * @state: Saved state returned from pci_store_saved_state()
1134  */
1135 static int pci_load_saved_state(struct pci_dev *dev,
1136 				struct pci_saved_state *state)
1137 {
1138 	struct pci_cap_saved_data *cap;
1139 
1140 	dev->state_saved = false;
1141 
1142 	if (!state)
1143 		return 0;
1144 
1145 	memcpy(dev->saved_config_space, state->config_space,
1146 	       sizeof(state->config_space));
1147 
1148 	cap = state->cap;
1149 	while (cap->size) {
1150 		struct pci_cap_saved_state *tmp;
1151 
1152 		tmp = _pci_find_saved_cap(dev, cap->cap_nr, cap->cap_extended);
1153 		if (!tmp || tmp->cap.size != cap->size)
1154 			return -EINVAL;
1155 
1156 		memcpy(tmp->cap.data, cap->data, tmp->cap.size);
1157 		cap = (struct pci_cap_saved_data *)((u8 *)cap +
1158 		       sizeof(struct pci_cap_saved_data) + cap->size);
1159 	}
1160 
1161 	dev->state_saved = true;
1162 	return 0;
1163 }
1164 
1165 /**
1166  * pci_load_and_free_saved_state - Reload the save state pointed to by state,
1167  *				   and free the memory allocated for it.
1168  * @dev: PCI device that we're dealing with
1169  * @state: Pointer to saved state returned from pci_store_saved_state()
1170  */
1171 int pci_load_and_free_saved_state(struct pci_dev *dev,
1172 				  struct pci_saved_state **state)
1173 {
1174 	int ret = pci_load_saved_state(dev, *state);
1175 	kfree(*state);
1176 	*state = NULL;
1177 	return ret;
1178 }
1179 EXPORT_SYMBOL_GPL(pci_load_and_free_saved_state);
1180 
1181 static int do_pci_enable_device(struct pci_dev *dev, int bars)
1182 {
1183 	int err;
1184 	u16 cmd;
1185 	u8 pin;
1186 
1187 	err = pci_set_power_state(dev, PCI_D0);
1188 	if (err < 0 && err != -EIO)
1189 		return err;
1190 	err = pcibios_enable_device(dev, bars);
1191 	if (err < 0)
1192 		return err;
1193 	pci_fixup_device(pci_fixup_enable, dev);
1194 
1195 	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
1196 	if (pin) {
1197 		pci_read_config_word(dev, PCI_COMMAND, &cmd);
1198 		if (cmd & PCI_COMMAND_INTX_DISABLE)
1199 			pci_write_config_word(dev, PCI_COMMAND,
1200 					      cmd & ~PCI_COMMAND_INTX_DISABLE);
1201 	}
1202 
1203 	return 0;
1204 }
1205 
1206 /**
1207  * pci_reenable_device - Resume abandoned device
1208  * @dev: PCI device to be resumed
1209  *
1210  *  Note this function is a backend of pci_default_resume and is not supposed
1211  *  to be called by normal code, write proper resume handler and use it instead.
1212  */
1213 int pci_reenable_device(struct pci_dev *dev)
1214 {
1215 	if (pci_is_enabled(dev))
1216 		return do_pci_enable_device(dev, (1 << PCI_NUM_RESOURCES) - 1);
1217 	return 0;
1218 }
1219 
1220 static void pci_enable_bridge(struct pci_dev *dev)
1221 {
1222 	struct pci_dev *bridge;
1223 	int retval;
1224 
1225 	bridge = pci_upstream_bridge(dev);
1226 	if (bridge)
1227 		pci_enable_bridge(bridge);
1228 
1229 	if (pci_is_enabled(dev)) {
1230 		if (!dev->is_busmaster)
1231 			pci_set_master(dev);
1232 		return;
1233 	}
1234 
1235 	retval = pci_enable_device(dev);
1236 	if (retval)
1237 		dev_err(&dev->dev, "Error enabling bridge (%d), continuing\n",
1238 			retval);
1239 	pci_set_master(dev);
1240 }
1241 
1242 static int pci_enable_device_flags(struct pci_dev *dev, unsigned long flags)
1243 {
1244 	struct pci_dev *bridge;
1245 	int err;
1246 	int i, bars = 0;
1247 
1248 	/*
1249 	 * Power state could be unknown at this point, either due to a fresh
1250 	 * boot or a device removal call.  So get the current power state
1251 	 * so that things like MSI message writing will behave as expected
1252 	 * (e.g. if the device really is in D0 at enable time).
1253 	 */
1254 	if (dev->pm_cap) {
1255 		u16 pmcsr;
1256 		pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
1257 		dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
1258 	}
1259 
1260 	if (atomic_inc_return(&dev->enable_cnt) > 1)
1261 		return 0;		/* already enabled */
1262 
1263 	bridge = pci_upstream_bridge(dev);
1264 	if (bridge)
1265 		pci_enable_bridge(bridge);
1266 
1267 	/* only skip sriov related */
1268 	for (i = 0; i <= PCI_ROM_RESOURCE; i++)
1269 		if (dev->resource[i].flags & flags)
1270 			bars |= (1 << i);
1271 	for (i = PCI_BRIDGE_RESOURCES; i < DEVICE_COUNT_RESOURCE; i++)
1272 		if (dev->resource[i].flags & flags)
1273 			bars |= (1 << i);
1274 
1275 	err = do_pci_enable_device(dev, bars);
1276 	if (err < 0)
1277 		atomic_dec(&dev->enable_cnt);
1278 	return err;
1279 }
1280 
1281 /**
1282  * pci_enable_device_io - Initialize a device for use with IO space
1283  * @dev: PCI device to be initialized
1284  *
1285  *  Initialize device before it's used by a driver. Ask low-level code
1286  *  to enable I/O resources. Wake up the device if it was suspended.
1287  *  Beware, this function can fail.
1288  */
1289 int pci_enable_device_io(struct pci_dev *dev)
1290 {
1291 	return pci_enable_device_flags(dev, IORESOURCE_IO);
1292 }
1293 
1294 /**
1295  * pci_enable_device_mem - Initialize a device for use with Memory space
1296  * @dev: PCI device to be initialized
1297  *
1298  *  Initialize device before it's used by a driver. Ask low-level code
1299  *  to enable Memory resources. Wake up the device if it was suspended.
1300  *  Beware, this function can fail.
1301  */
1302 int pci_enable_device_mem(struct pci_dev *dev)
1303 {
1304 	return pci_enable_device_flags(dev, IORESOURCE_MEM);
1305 }
1306 
1307 /**
1308  * pci_enable_device - Initialize device before it's used by a driver.
1309  * @dev: PCI device to be initialized
1310  *
1311  *  Initialize device before it's used by a driver. Ask low-level code
1312  *  to enable I/O and memory. Wake up the device if it was suspended.
1313  *  Beware, this function can fail.
1314  *
1315  *  Note we don't actually enable the device many times if we call
1316  *  this function repeatedly (we just increment the count).
1317  */
1318 int pci_enable_device(struct pci_dev *dev)
1319 {
1320 	return pci_enable_device_flags(dev, IORESOURCE_MEM | IORESOURCE_IO);
1321 }
1322 
1323 /*
1324  * Managed PCI resources.  This manages device on/off, intx/msi/msix
1325  * on/off and BAR regions.  pci_dev itself records msi/msix status, so
1326  * there's no need to track it separately.  pci_devres is initialized
1327  * when a device is enabled using managed PCI device enable interface.
1328  */
1329 struct pci_devres {
1330 	unsigned int enabled:1;
1331 	unsigned int pinned:1;
1332 	unsigned int orig_intx:1;
1333 	unsigned int restore_intx:1;
1334 	u32 region_mask;
1335 };
1336 
1337 static void pcim_release(struct device *gendev, void *res)
1338 {
1339 	struct pci_dev *dev = container_of(gendev, struct pci_dev, dev);
1340 	struct pci_devres *this = res;
1341 	int i;
1342 
1343 	if (dev->msi_enabled)
1344 		pci_disable_msi(dev);
1345 	if (dev->msix_enabled)
1346 		pci_disable_msix(dev);
1347 
1348 	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++)
1349 		if (this->region_mask & (1 << i))
1350 			pci_release_region(dev, i);
1351 
1352 	if (this->restore_intx)
1353 		pci_intx(dev, this->orig_intx);
1354 
1355 	if (this->enabled && !this->pinned)
1356 		pci_disable_device(dev);
1357 }
1358 
1359 static struct pci_devres * get_pci_dr(struct pci_dev *pdev)
1360 {
1361 	struct pci_devres *dr, *new_dr;
1362 
1363 	dr = devres_find(&pdev->dev, pcim_release, NULL, NULL);
1364 	if (dr)
1365 		return dr;
1366 
1367 	new_dr = devres_alloc(pcim_release, sizeof(*new_dr), GFP_KERNEL);
1368 	if (!new_dr)
1369 		return NULL;
1370 	return devres_get(&pdev->dev, new_dr, NULL, NULL);
1371 }
1372 
1373 static struct pci_devres * find_pci_dr(struct pci_dev *pdev)
1374 {
1375 	if (pci_is_managed(pdev))
1376 		return devres_find(&pdev->dev, pcim_release, NULL, NULL);
1377 	return NULL;
1378 }
1379 
1380 /**
1381  * pcim_enable_device - Managed pci_enable_device()
1382  * @pdev: PCI device to be initialized
1383  *
1384  * Managed pci_enable_device().
1385  */
1386 int pcim_enable_device(struct pci_dev *pdev)
1387 {
1388 	struct pci_devres *dr;
1389 	int rc;
1390 
1391 	dr = get_pci_dr(pdev);
1392 	if (unlikely(!dr))
1393 		return -ENOMEM;
1394 	if (dr->enabled)
1395 		return 0;
1396 
1397 	rc = pci_enable_device(pdev);
1398 	if (!rc) {
1399 		pdev->is_managed = 1;
1400 		dr->enabled = 1;
1401 	}
1402 	return rc;
1403 }
1404 
1405 /**
1406  * pcim_pin_device - Pin managed PCI device
1407  * @pdev: PCI device to pin
1408  *
1409  * Pin managed PCI device @pdev.  Pinned device won't be disabled on
1410  * driver detach.  @pdev must have been enabled with
1411  * pcim_enable_device().
1412  */
1413 void pcim_pin_device(struct pci_dev *pdev)
1414 {
1415 	struct pci_devres *dr;
1416 
1417 	dr = find_pci_dr(pdev);
1418 	WARN_ON(!dr || !dr->enabled);
1419 	if (dr)
1420 		dr->pinned = 1;
1421 }
1422 
1423 /*
1424  * pcibios_add_device - provide arch specific hooks when adding device dev
1425  * @dev: the PCI device being added
1426  *
1427  * Permits the platform to provide architecture specific functionality when
1428  * devices are added. This is the default implementation. Architecture
1429  * implementations can override this.
1430  */
1431 int __weak pcibios_add_device (struct pci_dev *dev)
1432 {
1433 	return 0;
1434 }
1435 
1436 /**
1437  * pcibios_release_device - provide arch specific hooks when releasing device dev
1438  * @dev: the PCI device being released
1439  *
1440  * Permits the platform to provide architecture specific functionality when
1441  * devices are released. This is the default implementation. Architecture
1442  * implementations can override this.
1443  */
1444 void __weak pcibios_release_device(struct pci_dev *dev) {}
1445 
1446 /**
1447  * pcibios_disable_device - disable arch specific PCI resources for device dev
1448  * @dev: the PCI device to disable
1449  *
1450  * Disables architecture specific PCI resources for the device. This
1451  * is the default implementation. Architecture implementations can
1452  * override this.
1453  */
1454 void __weak pcibios_disable_device (struct pci_dev *dev) {}
1455 
1456 static void do_pci_disable_device(struct pci_dev *dev)
1457 {
1458 	u16 pci_command;
1459 
1460 	pci_read_config_word(dev, PCI_COMMAND, &pci_command);
1461 	if (pci_command & PCI_COMMAND_MASTER) {
1462 		pci_command &= ~PCI_COMMAND_MASTER;
1463 		pci_write_config_word(dev, PCI_COMMAND, pci_command);
1464 	}
1465 
1466 	pcibios_disable_device(dev);
1467 }
1468 
1469 /**
1470  * pci_disable_enabled_device - Disable device without updating enable_cnt
1471  * @dev: PCI device to disable
1472  *
1473  * NOTE: This function is a backend of PCI power management routines and is
1474  * not supposed to be called drivers.
1475  */
1476 void pci_disable_enabled_device(struct pci_dev *dev)
1477 {
1478 	if (pci_is_enabled(dev))
1479 		do_pci_disable_device(dev);
1480 }
1481 
1482 /**
1483  * pci_disable_device - Disable PCI device after use
1484  * @dev: PCI device to be disabled
1485  *
1486  * Signal to the system that the PCI device is not in use by the system
1487  * anymore.  This only involves disabling PCI bus-mastering, if active.
1488  *
1489  * Note we don't actually disable the device until all callers of
1490  * pci_enable_device() have called pci_disable_device().
1491  */
1492 void
1493 pci_disable_device(struct pci_dev *dev)
1494 {
1495 	struct pci_devres *dr;
1496 
1497 	dr = find_pci_dr(dev);
1498 	if (dr)
1499 		dr->enabled = 0;
1500 
1501 	dev_WARN_ONCE(&dev->dev, atomic_read(&dev->enable_cnt) <= 0,
1502 		      "disabling already-disabled device");
1503 
1504 	if (atomic_dec_return(&dev->enable_cnt) != 0)
1505 		return;
1506 
1507 	do_pci_disable_device(dev);
1508 
1509 	dev->is_busmaster = 0;
1510 }
1511 
1512 /**
1513  * pcibios_set_pcie_reset_state - set reset state for device dev
1514  * @dev: the PCIe device reset
1515  * @state: Reset state to enter into
1516  *
1517  *
1518  * Sets the PCIe reset state for the device. This is the default
1519  * implementation. Architecture implementations can override this.
1520  */
1521 int __weak pcibios_set_pcie_reset_state(struct pci_dev *dev,
1522 					enum pcie_reset_state state)
1523 {
1524 	return -EINVAL;
1525 }
1526 
1527 /**
1528  * pci_set_pcie_reset_state - set reset state for device dev
1529  * @dev: the PCIe device reset
1530  * @state: Reset state to enter into
1531  *
1532  *
1533  * Sets the PCI reset state for the device.
1534  */
1535 int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state)
1536 {
1537 	return pcibios_set_pcie_reset_state(dev, state);
1538 }
1539 
1540 /**
1541  * pci_check_pme_status - Check if given device has generated PME.
1542  * @dev: Device to check.
1543  *
1544  * Check the PME status of the device and if set, clear it and clear PME enable
1545  * (if set).  Return 'true' if PME status and PME enable were both set or
1546  * 'false' otherwise.
1547  */
1548 bool pci_check_pme_status(struct pci_dev *dev)
1549 {
1550 	int pmcsr_pos;
1551 	u16 pmcsr;
1552 	bool ret = false;
1553 
1554 	if (!dev->pm_cap)
1555 		return false;
1556 
1557 	pmcsr_pos = dev->pm_cap + PCI_PM_CTRL;
1558 	pci_read_config_word(dev, pmcsr_pos, &pmcsr);
1559 	if (!(pmcsr & PCI_PM_CTRL_PME_STATUS))
1560 		return false;
1561 
1562 	/* Clear PME status. */
1563 	pmcsr |= PCI_PM_CTRL_PME_STATUS;
1564 	if (pmcsr & PCI_PM_CTRL_PME_ENABLE) {
1565 		/* Disable PME to avoid interrupt flood. */
1566 		pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
1567 		ret = true;
1568 	}
1569 
1570 	pci_write_config_word(dev, pmcsr_pos, pmcsr);
1571 
1572 	return ret;
1573 }
1574 
1575 /**
1576  * pci_pme_wakeup - Wake up a PCI device if its PME Status bit is set.
1577  * @dev: Device to handle.
1578  * @pme_poll_reset: Whether or not to reset the device's pme_poll flag.
1579  *
1580  * Check if @dev has generated PME and queue a resume request for it in that
1581  * case.
1582  */
1583 static int pci_pme_wakeup(struct pci_dev *dev, void *pme_poll_reset)
1584 {
1585 	if (pme_poll_reset && dev->pme_poll)
1586 		dev->pme_poll = false;
1587 
1588 	if (pci_check_pme_status(dev)) {
1589 		pci_wakeup_event(dev);
1590 		pm_request_resume(&dev->dev);
1591 	}
1592 	return 0;
1593 }
1594 
1595 /**
1596  * pci_pme_wakeup_bus - Walk given bus and wake up devices on it, if necessary.
1597  * @bus: Top bus of the subtree to walk.
1598  */
1599 void pci_pme_wakeup_bus(struct pci_bus *bus)
1600 {
1601 	if (bus)
1602 		pci_walk_bus(bus, pci_pme_wakeup, (void *)true);
1603 }
1604 
1605 
1606 /**
1607  * pci_pme_capable - check the capability of PCI device to generate PME#
1608  * @dev: PCI device to handle.
1609  * @state: PCI state from which device will issue PME#.
1610  */
1611 bool pci_pme_capable(struct pci_dev *dev, pci_power_t state)
1612 {
1613 	if (!dev->pm_cap)
1614 		return false;
1615 
1616 	return !!(dev->pme_support & (1 << state));
1617 }
1618 
1619 static void pci_pme_list_scan(struct work_struct *work)
1620 {
1621 	struct pci_pme_device *pme_dev, *n;
1622 
1623 	mutex_lock(&pci_pme_list_mutex);
1624 	if (!list_empty(&pci_pme_list)) {
1625 		list_for_each_entry_safe(pme_dev, n, &pci_pme_list, list) {
1626 			if (pme_dev->dev->pme_poll) {
1627 				struct pci_dev *bridge;
1628 
1629 				bridge = pme_dev->dev->bus->self;
1630 				/*
1631 				 * If bridge is in low power state, the
1632 				 * configuration space of subordinate devices
1633 				 * may be not accessible
1634 				 */
1635 				if (bridge && bridge->current_state != PCI_D0)
1636 					continue;
1637 				pci_pme_wakeup(pme_dev->dev, NULL);
1638 			} else {
1639 				list_del(&pme_dev->list);
1640 				kfree(pme_dev);
1641 			}
1642 		}
1643 		if (!list_empty(&pci_pme_list))
1644 			schedule_delayed_work(&pci_pme_work,
1645 					      msecs_to_jiffies(PME_TIMEOUT));
1646 	}
1647 	mutex_unlock(&pci_pme_list_mutex);
1648 }
1649 
1650 /**
1651  * pci_pme_active - enable or disable PCI device's PME# function
1652  * @dev: PCI device to handle.
1653  * @enable: 'true' to enable PME# generation; 'false' to disable it.
1654  *
1655  * The caller must verify that the device is capable of generating PME# before
1656  * calling this function with @enable equal to 'true'.
1657  */
1658 void pci_pme_active(struct pci_dev *dev, bool enable)
1659 {
1660 	u16 pmcsr;
1661 
1662 	if (!dev->pme_support)
1663 		return;
1664 
1665 	pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
1666 	/* Clear PME_Status by writing 1 to it and enable PME# */
1667 	pmcsr |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE;
1668 	if (!enable)
1669 		pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
1670 
1671 	pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
1672 
1673 	/*
1674 	 * PCI (as opposed to PCIe) PME requires that the device have
1675 	 * its PME# line hooked up correctly. Not all hardware vendors
1676 	 * do this, so the PME never gets delivered and the device
1677 	 * remains asleep. The easiest way around this is to
1678 	 * periodically walk the list of suspended devices and check
1679 	 * whether any have their PME flag set. The assumption is that
1680 	 * we'll wake up often enough anyway that this won't be a huge
1681 	 * hit, and the power savings from the devices will still be a
1682 	 * win.
1683 	 *
1684 	 * Although PCIe uses in-band PME message instead of PME# line
1685 	 * to report PME, PME does not work for some PCIe devices in
1686 	 * reality.  For example, there are devices that set their PME
1687 	 * status bits, but don't really bother to send a PME message;
1688 	 * there are PCI Express Root Ports that don't bother to
1689 	 * trigger interrupts when they receive PME messages from the
1690 	 * devices below.  So PME poll is used for PCIe devices too.
1691 	 */
1692 
1693 	if (dev->pme_poll) {
1694 		struct pci_pme_device *pme_dev;
1695 		if (enable) {
1696 			pme_dev = kmalloc(sizeof(struct pci_pme_device),
1697 					  GFP_KERNEL);
1698 			if (!pme_dev) {
1699 				dev_warn(&dev->dev, "can't enable PME#\n");
1700 				return;
1701 			}
1702 			pme_dev->dev = dev;
1703 			mutex_lock(&pci_pme_list_mutex);
1704 			list_add(&pme_dev->list, &pci_pme_list);
1705 			if (list_is_singular(&pci_pme_list))
1706 				schedule_delayed_work(&pci_pme_work,
1707 						      msecs_to_jiffies(PME_TIMEOUT));
1708 			mutex_unlock(&pci_pme_list_mutex);
1709 		} else {
1710 			mutex_lock(&pci_pme_list_mutex);
1711 			list_for_each_entry(pme_dev, &pci_pme_list, list) {
1712 				if (pme_dev->dev == dev) {
1713 					list_del(&pme_dev->list);
1714 					kfree(pme_dev);
1715 					break;
1716 				}
1717 			}
1718 			mutex_unlock(&pci_pme_list_mutex);
1719 		}
1720 	}
1721 
1722 	dev_dbg(&dev->dev, "PME# %s\n", enable ? "enabled" : "disabled");
1723 }
1724 
1725 /**
1726  * __pci_enable_wake - enable PCI device as wakeup event source
1727  * @dev: PCI device affected
1728  * @state: PCI state from which device will issue wakeup events
1729  * @runtime: True if the events are to be generated at run time
1730  * @enable: True to enable event generation; false to disable
1731  *
1732  * This enables the device as a wakeup event source, or disables it.
1733  * When such events involves platform-specific hooks, those hooks are
1734  * called automatically by this routine.
1735  *
1736  * Devices with legacy power management (no standard PCI PM capabilities)
1737  * always require such platform hooks.
1738  *
1739  * RETURN VALUE:
1740  * 0 is returned on success
1741  * -EINVAL is returned if device is not supposed to wake up the system
1742  * Error code depending on the platform is returned if both the platform and
1743  * the native mechanism fail to enable the generation of wake-up events
1744  */
1745 int __pci_enable_wake(struct pci_dev *dev, pci_power_t state,
1746 		      bool runtime, bool enable)
1747 {
1748 	int ret = 0;
1749 
1750 	if (enable && !runtime && !device_may_wakeup(&dev->dev))
1751 		return -EINVAL;
1752 
1753 	/* Don't do the same thing twice in a row for one device. */
1754 	if (!!enable == !!dev->wakeup_prepared)
1755 		return 0;
1756 
1757 	/*
1758 	 * According to "PCI System Architecture" 4th ed. by Tom Shanley & Don
1759 	 * Anderson we should be doing PME# wake enable followed by ACPI wake
1760 	 * enable.  To disable wake-up we call the platform first, for symmetry.
1761 	 */
1762 
1763 	if (enable) {
1764 		int error;
1765 
1766 		if (pci_pme_capable(dev, state))
1767 			pci_pme_active(dev, true);
1768 		else
1769 			ret = 1;
1770 		error = runtime ? platform_pci_run_wake(dev, true) :
1771 					platform_pci_sleep_wake(dev, true);
1772 		if (ret)
1773 			ret = error;
1774 		if (!ret)
1775 			dev->wakeup_prepared = true;
1776 	} else {
1777 		if (runtime)
1778 			platform_pci_run_wake(dev, false);
1779 		else
1780 			platform_pci_sleep_wake(dev, false);
1781 		pci_pme_active(dev, false);
1782 		dev->wakeup_prepared = false;
1783 	}
1784 
1785 	return ret;
1786 }
1787 EXPORT_SYMBOL(__pci_enable_wake);
1788 
1789 /**
1790  * pci_wake_from_d3 - enable/disable device to wake up from D3_hot or D3_cold
1791  * @dev: PCI device to prepare
1792  * @enable: True to enable wake-up event generation; false to disable
1793  *
1794  * Many drivers want the device to wake up the system from D3_hot or D3_cold
1795  * and this function allows them to set that up cleanly - pci_enable_wake()
1796  * should not be called twice in a row to enable wake-up due to PCI PM vs ACPI
1797  * ordering constraints.
1798  *
1799  * This function only returns error code if the device is not capable of
1800  * generating PME# from both D3_hot and D3_cold, and the platform is unable to
1801  * enable wake-up power for it.
1802  */
1803 int pci_wake_from_d3(struct pci_dev *dev, bool enable)
1804 {
1805 	return pci_pme_capable(dev, PCI_D3cold) ?
1806 			pci_enable_wake(dev, PCI_D3cold, enable) :
1807 			pci_enable_wake(dev, PCI_D3hot, enable);
1808 }
1809 
1810 /**
1811  * pci_target_state - find an appropriate low power state for a given PCI dev
1812  * @dev: PCI device
1813  *
1814  * Use underlying platform code to find a supported low power state for @dev.
1815  * If the platform can't manage @dev, return the deepest state from which it
1816  * can generate wake events, based on any available PME info.
1817  */
1818 static pci_power_t pci_target_state(struct pci_dev *dev)
1819 {
1820 	pci_power_t target_state = PCI_D3hot;
1821 
1822 	if (platform_pci_power_manageable(dev)) {
1823 		/*
1824 		 * Call the platform to choose the target state of the device
1825 		 * and enable wake-up from this state if supported.
1826 		 */
1827 		pci_power_t state = platform_pci_choose_state(dev);
1828 
1829 		switch (state) {
1830 		case PCI_POWER_ERROR:
1831 		case PCI_UNKNOWN:
1832 			break;
1833 		case PCI_D1:
1834 		case PCI_D2:
1835 			if (pci_no_d1d2(dev))
1836 				break;
1837 		default:
1838 			target_state = state;
1839 		}
1840 	} else if (!dev->pm_cap) {
1841 		target_state = PCI_D0;
1842 	} else if (device_may_wakeup(&dev->dev)) {
1843 		/*
1844 		 * Find the deepest state from which the device can generate
1845 		 * wake-up events, make it the target state and enable device
1846 		 * to generate PME#.
1847 		 */
1848 		if (dev->pme_support) {
1849 			while (target_state
1850 			      && !(dev->pme_support & (1 << target_state)))
1851 				target_state--;
1852 		}
1853 	}
1854 
1855 	return target_state;
1856 }
1857 
1858 /**
1859  * pci_prepare_to_sleep - prepare PCI device for system-wide transition into a sleep state
1860  * @dev: Device to handle.
1861  *
1862  * Choose the power state appropriate for the device depending on whether
1863  * it can wake up the system and/or is power manageable by the platform
1864  * (PCI_D3hot is the default) and put the device into that state.
1865  */
1866 int pci_prepare_to_sleep(struct pci_dev *dev)
1867 {
1868 	pci_power_t target_state = pci_target_state(dev);
1869 	int error;
1870 
1871 	if (target_state == PCI_POWER_ERROR)
1872 		return -EIO;
1873 
1874 	/* D3cold during system suspend/hibernate is not supported */
1875 	if (target_state > PCI_D3hot)
1876 		target_state = PCI_D3hot;
1877 
1878 	pci_enable_wake(dev, target_state, device_may_wakeup(&dev->dev));
1879 
1880 	error = pci_set_power_state(dev, target_state);
1881 
1882 	if (error)
1883 		pci_enable_wake(dev, target_state, false);
1884 
1885 	return error;
1886 }
1887 
1888 /**
1889  * pci_back_from_sleep - turn PCI device on during system-wide transition into working state
1890  * @dev: Device to handle.
1891  *
1892  * Disable device's system wake-up capability and put it into D0.
1893  */
1894 int pci_back_from_sleep(struct pci_dev *dev)
1895 {
1896 	pci_enable_wake(dev, PCI_D0, false);
1897 	return pci_set_power_state(dev, PCI_D0);
1898 }
1899 
1900 /**
1901  * pci_finish_runtime_suspend - Carry out PCI-specific part of runtime suspend.
1902  * @dev: PCI device being suspended.
1903  *
1904  * Prepare @dev to generate wake-up events at run time and put it into a low
1905  * power state.
1906  */
1907 int pci_finish_runtime_suspend(struct pci_dev *dev)
1908 {
1909 	pci_power_t target_state = pci_target_state(dev);
1910 	int error;
1911 
1912 	if (target_state == PCI_POWER_ERROR)
1913 		return -EIO;
1914 
1915 	dev->runtime_d3cold = target_state == PCI_D3cold;
1916 
1917 	__pci_enable_wake(dev, target_state, true, pci_dev_run_wake(dev));
1918 
1919 	error = pci_set_power_state(dev, target_state);
1920 
1921 	if (error) {
1922 		__pci_enable_wake(dev, target_state, true, false);
1923 		dev->runtime_d3cold = false;
1924 	}
1925 
1926 	return error;
1927 }
1928 
1929 /**
1930  * pci_dev_run_wake - Check if device can generate run-time wake-up events.
1931  * @dev: Device to check.
1932  *
1933  * Return true if the device itself is capable of generating wake-up events
1934  * (through the platform or using the native PCIe PME) or if the device supports
1935  * PME and one of its upstream bridges can generate wake-up events.
1936  */
1937 bool pci_dev_run_wake(struct pci_dev *dev)
1938 {
1939 	struct pci_bus *bus = dev->bus;
1940 
1941 	if (device_run_wake(&dev->dev))
1942 		return true;
1943 
1944 	if (!dev->pme_support)
1945 		return false;
1946 
1947 	while (bus->parent) {
1948 		struct pci_dev *bridge = bus->self;
1949 
1950 		if (device_run_wake(&bridge->dev))
1951 			return true;
1952 
1953 		bus = bus->parent;
1954 	}
1955 
1956 	/* We have reached the root bus. */
1957 	if (bus->bridge)
1958 		return device_run_wake(bus->bridge);
1959 
1960 	return false;
1961 }
1962 EXPORT_SYMBOL_GPL(pci_dev_run_wake);
1963 
1964 void pci_config_pm_runtime_get(struct pci_dev *pdev)
1965 {
1966 	struct device *dev = &pdev->dev;
1967 	struct device *parent = dev->parent;
1968 
1969 	if (parent)
1970 		pm_runtime_get_sync(parent);
1971 	pm_runtime_get_noresume(dev);
1972 	/*
1973 	 * pdev->current_state is set to PCI_D3cold during suspending,
1974 	 * so wait until suspending completes
1975 	 */
1976 	pm_runtime_barrier(dev);
1977 	/*
1978 	 * Only need to resume devices in D3cold, because config
1979 	 * registers are still accessible for devices suspended but
1980 	 * not in D3cold.
1981 	 */
1982 	if (pdev->current_state == PCI_D3cold)
1983 		pm_runtime_resume(dev);
1984 }
1985 
1986 void pci_config_pm_runtime_put(struct pci_dev *pdev)
1987 {
1988 	struct device *dev = &pdev->dev;
1989 	struct device *parent = dev->parent;
1990 
1991 	pm_runtime_put(dev);
1992 	if (parent)
1993 		pm_runtime_put_sync(parent);
1994 }
1995 
1996 /**
1997  * pci_pm_init - Initialize PM functions of given PCI device
1998  * @dev: PCI device to handle.
1999  */
2000 void pci_pm_init(struct pci_dev *dev)
2001 {
2002 	int pm;
2003 	u16 pmc;
2004 
2005 	pm_runtime_forbid(&dev->dev);
2006 	pm_runtime_set_active(&dev->dev);
2007 	pm_runtime_enable(&dev->dev);
2008 	device_enable_async_suspend(&dev->dev);
2009 	dev->wakeup_prepared = false;
2010 
2011 	dev->pm_cap = 0;
2012 	dev->pme_support = 0;
2013 
2014 	/* find PCI PM capability in list */
2015 	pm = pci_find_capability(dev, PCI_CAP_ID_PM);
2016 	if (!pm)
2017 		return;
2018 	/* Check device's ability to generate PME# */
2019 	pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
2020 
2021 	if ((pmc & PCI_PM_CAP_VER_MASK) > 3) {
2022 		dev_err(&dev->dev, "unsupported PM cap regs version (%u)\n",
2023 			pmc & PCI_PM_CAP_VER_MASK);
2024 		return;
2025 	}
2026 
2027 	dev->pm_cap = pm;
2028 	dev->d3_delay = PCI_PM_D3_WAIT;
2029 	dev->d3cold_delay = PCI_PM_D3COLD_WAIT;
2030 	dev->d3cold_allowed = true;
2031 
2032 	dev->d1_support = false;
2033 	dev->d2_support = false;
2034 	if (!pci_no_d1d2(dev)) {
2035 		if (pmc & PCI_PM_CAP_D1)
2036 			dev->d1_support = true;
2037 		if (pmc & PCI_PM_CAP_D2)
2038 			dev->d2_support = true;
2039 
2040 		if (dev->d1_support || dev->d2_support)
2041 			dev_printk(KERN_DEBUG, &dev->dev, "supports%s%s\n",
2042 				   dev->d1_support ? " D1" : "",
2043 				   dev->d2_support ? " D2" : "");
2044 	}
2045 
2046 	pmc &= PCI_PM_CAP_PME_MASK;
2047 	if (pmc) {
2048 		dev_printk(KERN_DEBUG, &dev->dev,
2049 			 "PME# supported from%s%s%s%s%s\n",
2050 			 (pmc & PCI_PM_CAP_PME_D0) ? " D0" : "",
2051 			 (pmc & PCI_PM_CAP_PME_D1) ? " D1" : "",
2052 			 (pmc & PCI_PM_CAP_PME_D2) ? " D2" : "",
2053 			 (pmc & PCI_PM_CAP_PME_D3) ? " D3hot" : "",
2054 			 (pmc & PCI_PM_CAP_PME_D3cold) ? " D3cold" : "");
2055 		dev->pme_support = pmc >> PCI_PM_CAP_PME_SHIFT;
2056 		dev->pme_poll = true;
2057 		/*
2058 		 * Make device's PM flags reflect the wake-up capability, but
2059 		 * let the user space enable it to wake up the system as needed.
2060 		 */
2061 		device_set_wakeup_capable(&dev->dev, true);
2062 		/* Disable the PME# generation functionality */
2063 		pci_pme_active(dev, false);
2064 	}
2065 }
2066 
2067 static void pci_add_saved_cap(struct pci_dev *pci_dev,
2068 	struct pci_cap_saved_state *new_cap)
2069 {
2070 	hlist_add_head(&new_cap->next, &pci_dev->saved_cap_space);
2071 }
2072 
2073 /**
2074  * _pci_add_cap_save_buffer - allocate buffer for saving given
2075  *                            capability registers
2076  * @dev: the PCI device
2077  * @cap: the capability to allocate the buffer for
2078  * @extended: Standard or Extended capability ID
2079  * @size: requested size of the buffer
2080  */
2081 static int _pci_add_cap_save_buffer(struct pci_dev *dev, u16 cap,
2082 				    bool extended, unsigned int size)
2083 {
2084 	int pos;
2085 	struct pci_cap_saved_state *save_state;
2086 
2087 	if (extended)
2088 		pos = pci_find_ext_capability(dev, cap);
2089 	else
2090 		pos = pci_find_capability(dev, cap);
2091 
2092 	if (pos <= 0)
2093 		return 0;
2094 
2095 	save_state = kzalloc(sizeof(*save_state) + size, GFP_KERNEL);
2096 	if (!save_state)
2097 		return -ENOMEM;
2098 
2099 	save_state->cap.cap_nr = cap;
2100 	save_state->cap.cap_extended = extended;
2101 	save_state->cap.size = size;
2102 	pci_add_saved_cap(dev, save_state);
2103 
2104 	return 0;
2105 }
2106 
2107 int pci_add_cap_save_buffer(struct pci_dev *dev, char cap, unsigned int size)
2108 {
2109 	return _pci_add_cap_save_buffer(dev, cap, false, size);
2110 }
2111 
2112 int pci_add_ext_cap_save_buffer(struct pci_dev *dev, u16 cap, unsigned int size)
2113 {
2114 	return _pci_add_cap_save_buffer(dev, cap, true, size);
2115 }
2116 
2117 /**
2118  * pci_allocate_cap_save_buffers - allocate buffers for saving capabilities
2119  * @dev: the PCI device
2120  */
2121 void pci_allocate_cap_save_buffers(struct pci_dev *dev)
2122 {
2123 	int error;
2124 
2125 	error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_EXP,
2126 					PCI_EXP_SAVE_REGS * sizeof(u16));
2127 	if (error)
2128 		dev_err(&dev->dev,
2129 			"unable to preallocate PCI Express save buffer\n");
2130 
2131 	error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_PCIX, sizeof(u16));
2132 	if (error)
2133 		dev_err(&dev->dev,
2134 			"unable to preallocate PCI-X save buffer\n");
2135 
2136 	pci_allocate_vc_save_buffers(dev);
2137 }
2138 
2139 void pci_free_cap_save_buffers(struct pci_dev *dev)
2140 {
2141 	struct pci_cap_saved_state *tmp;
2142 	struct hlist_node *n;
2143 
2144 	hlist_for_each_entry_safe(tmp, n, &dev->saved_cap_space, next)
2145 		kfree(tmp);
2146 }
2147 
2148 /**
2149  * pci_configure_ari - enable or disable ARI forwarding
2150  * @dev: the PCI device
2151  *
2152  * If @dev and its upstream bridge both support ARI, enable ARI in the
2153  * bridge.  Otherwise, disable ARI in the bridge.
2154  */
2155 void pci_configure_ari(struct pci_dev *dev)
2156 {
2157 	u32 cap;
2158 	struct pci_dev *bridge;
2159 
2160 	if (pcie_ari_disabled || !pci_is_pcie(dev) || dev->devfn)
2161 		return;
2162 
2163 	bridge = dev->bus->self;
2164 	if (!bridge)
2165 		return;
2166 
2167 	pcie_capability_read_dword(bridge, PCI_EXP_DEVCAP2, &cap);
2168 	if (!(cap & PCI_EXP_DEVCAP2_ARI))
2169 		return;
2170 
2171 	if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI)) {
2172 		pcie_capability_set_word(bridge, PCI_EXP_DEVCTL2,
2173 					 PCI_EXP_DEVCTL2_ARI);
2174 		bridge->ari_enabled = 1;
2175 	} else {
2176 		pcie_capability_clear_word(bridge, PCI_EXP_DEVCTL2,
2177 					   PCI_EXP_DEVCTL2_ARI);
2178 		bridge->ari_enabled = 0;
2179 	}
2180 }
2181 
2182 static int pci_acs_enable;
2183 
2184 /**
2185  * pci_request_acs - ask for ACS to be enabled if supported
2186  */
2187 void pci_request_acs(void)
2188 {
2189 	pci_acs_enable = 1;
2190 }
2191 
2192 /**
2193  * pci_enable_acs - enable ACS if hardware support it
2194  * @dev: the PCI device
2195  */
2196 void pci_enable_acs(struct pci_dev *dev)
2197 {
2198 	int pos;
2199 	u16 cap;
2200 	u16 ctrl;
2201 
2202 	if (!pci_acs_enable)
2203 		return;
2204 
2205 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS);
2206 	if (!pos)
2207 		return;
2208 
2209 	pci_read_config_word(dev, pos + PCI_ACS_CAP, &cap);
2210 	pci_read_config_word(dev, pos + PCI_ACS_CTRL, &ctrl);
2211 
2212 	/* Source Validation */
2213 	ctrl |= (cap & PCI_ACS_SV);
2214 
2215 	/* P2P Request Redirect */
2216 	ctrl |= (cap & PCI_ACS_RR);
2217 
2218 	/* P2P Completion Redirect */
2219 	ctrl |= (cap & PCI_ACS_CR);
2220 
2221 	/* Upstream Forwarding */
2222 	ctrl |= (cap & PCI_ACS_UF);
2223 
2224 	pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl);
2225 }
2226 
2227 static bool pci_acs_flags_enabled(struct pci_dev *pdev, u16 acs_flags)
2228 {
2229 	int pos;
2230 	u16 cap, ctrl;
2231 
2232 	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ACS);
2233 	if (!pos)
2234 		return false;
2235 
2236 	/*
2237 	 * Except for egress control, capabilities are either required
2238 	 * or only required if controllable.  Features missing from the
2239 	 * capability field can therefore be assumed as hard-wired enabled.
2240 	 */
2241 	pci_read_config_word(pdev, pos + PCI_ACS_CAP, &cap);
2242 	acs_flags &= (cap | PCI_ACS_EC);
2243 
2244 	pci_read_config_word(pdev, pos + PCI_ACS_CTRL, &ctrl);
2245 	return (ctrl & acs_flags) == acs_flags;
2246 }
2247 
2248 /**
2249  * pci_acs_enabled - test ACS against required flags for a given device
2250  * @pdev: device to test
2251  * @acs_flags: required PCI ACS flags
2252  *
2253  * Return true if the device supports the provided flags.  Automatically
2254  * filters out flags that are not implemented on multifunction devices.
2255  *
2256  * Note that this interface checks the effective ACS capabilities of the
2257  * device rather than the actual capabilities.  For instance, most single
2258  * function endpoints are not required to support ACS because they have no
2259  * opportunity for peer-to-peer access.  We therefore return 'true'
2260  * regardless of whether the device exposes an ACS capability.  This makes
2261  * it much easier for callers of this function to ignore the actual type
2262  * or topology of the device when testing ACS support.
2263  */
2264 bool pci_acs_enabled(struct pci_dev *pdev, u16 acs_flags)
2265 {
2266 	int ret;
2267 
2268 	ret = pci_dev_specific_acs_enabled(pdev, acs_flags);
2269 	if (ret >= 0)
2270 		return ret > 0;
2271 
2272 	/*
2273 	 * Conventional PCI and PCI-X devices never support ACS, either
2274 	 * effectively or actually.  The shared bus topology implies that
2275 	 * any device on the bus can receive or snoop DMA.
2276 	 */
2277 	if (!pci_is_pcie(pdev))
2278 		return false;
2279 
2280 	switch (pci_pcie_type(pdev)) {
2281 	/*
2282 	 * PCI/X-to-PCIe bridges are not specifically mentioned by the spec,
2283 	 * but since their primary interface is PCI/X, we conservatively
2284 	 * handle them as we would a non-PCIe device.
2285 	 */
2286 	case PCI_EXP_TYPE_PCIE_BRIDGE:
2287 	/*
2288 	 * PCIe 3.0, 6.12.1 excludes ACS on these devices.  "ACS is never
2289 	 * applicable... must never implement an ACS Extended Capability...".
2290 	 * This seems arbitrary, but we take a conservative interpretation
2291 	 * of this statement.
2292 	 */
2293 	case PCI_EXP_TYPE_PCI_BRIDGE:
2294 	case PCI_EXP_TYPE_RC_EC:
2295 		return false;
2296 	/*
2297 	 * PCIe 3.0, 6.12.1.1 specifies that downstream and root ports should
2298 	 * implement ACS in order to indicate their peer-to-peer capabilities,
2299 	 * regardless of whether they are single- or multi-function devices.
2300 	 */
2301 	case PCI_EXP_TYPE_DOWNSTREAM:
2302 	case PCI_EXP_TYPE_ROOT_PORT:
2303 		return pci_acs_flags_enabled(pdev, acs_flags);
2304 	/*
2305 	 * PCIe 3.0, 6.12.1.2 specifies ACS capabilities that should be
2306 	 * implemented by the remaining PCIe types to indicate peer-to-peer
2307 	 * capabilities, but only when they are part of a multifunction
2308 	 * device.  The footnote for section 6.12 indicates the specific
2309 	 * PCIe types included here.
2310 	 */
2311 	case PCI_EXP_TYPE_ENDPOINT:
2312 	case PCI_EXP_TYPE_UPSTREAM:
2313 	case PCI_EXP_TYPE_LEG_END:
2314 	case PCI_EXP_TYPE_RC_END:
2315 		if (!pdev->multifunction)
2316 			break;
2317 
2318 		return pci_acs_flags_enabled(pdev, acs_flags);
2319 	}
2320 
2321 	/*
2322 	 * PCIe 3.0, 6.12.1.3 specifies no ACS capabilities are applicable
2323 	 * to single function devices with the exception of downstream ports.
2324 	 */
2325 	return true;
2326 }
2327 
2328 /**
2329  * pci_acs_path_enable - test ACS flags from start to end in a hierarchy
2330  * @start: starting downstream device
2331  * @end: ending upstream device or NULL to search to the root bus
2332  * @acs_flags: required flags
2333  *
2334  * Walk up a device tree from start to end testing PCI ACS support.  If
2335  * any step along the way does not support the required flags, return false.
2336  */
2337 bool pci_acs_path_enabled(struct pci_dev *start,
2338 			  struct pci_dev *end, u16 acs_flags)
2339 {
2340 	struct pci_dev *pdev, *parent = start;
2341 
2342 	do {
2343 		pdev = parent;
2344 
2345 		if (!pci_acs_enabled(pdev, acs_flags))
2346 			return false;
2347 
2348 		if (pci_is_root_bus(pdev->bus))
2349 			return (end == NULL);
2350 
2351 		parent = pdev->bus->self;
2352 	} while (pdev != end);
2353 
2354 	return true;
2355 }
2356 
2357 /**
2358  * pci_swizzle_interrupt_pin - swizzle INTx for device behind bridge
2359  * @dev: the PCI device
2360  * @pin: the INTx pin (1=INTA, 2=INTB, 3=INTC, 4=INTD)
2361  *
2362  * Perform INTx swizzling for a device behind one level of bridge.  This is
2363  * required by section 9.1 of the PCI-to-PCI bridge specification for devices
2364  * behind bridges on add-in cards.  For devices with ARI enabled, the slot
2365  * number is always 0 (see the Implementation Note in section 2.2.8.1 of
2366  * the PCI Express Base Specification, Revision 2.1)
2367  */
2368 u8 pci_swizzle_interrupt_pin(const struct pci_dev *dev, u8 pin)
2369 {
2370 	int slot;
2371 
2372 	if (pci_ari_enabled(dev->bus))
2373 		slot = 0;
2374 	else
2375 		slot = PCI_SLOT(dev->devfn);
2376 
2377 	return (((pin - 1) + slot) % 4) + 1;
2378 }
2379 
2380 int
2381 pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge)
2382 {
2383 	u8 pin;
2384 
2385 	pin = dev->pin;
2386 	if (!pin)
2387 		return -1;
2388 
2389 	while (!pci_is_root_bus(dev->bus)) {
2390 		pin = pci_swizzle_interrupt_pin(dev, pin);
2391 		dev = dev->bus->self;
2392 	}
2393 	*bridge = dev;
2394 	return pin;
2395 }
2396 
2397 /**
2398  * pci_common_swizzle - swizzle INTx all the way to root bridge
2399  * @dev: the PCI device
2400  * @pinp: pointer to the INTx pin value (1=INTA, 2=INTB, 3=INTD, 4=INTD)
2401  *
2402  * Perform INTx swizzling for a device.  This traverses through all PCI-to-PCI
2403  * bridges all the way up to a PCI root bus.
2404  */
2405 u8 pci_common_swizzle(struct pci_dev *dev, u8 *pinp)
2406 {
2407 	u8 pin = *pinp;
2408 
2409 	while (!pci_is_root_bus(dev->bus)) {
2410 		pin = pci_swizzle_interrupt_pin(dev, pin);
2411 		dev = dev->bus->self;
2412 	}
2413 	*pinp = pin;
2414 	return PCI_SLOT(dev->devfn);
2415 }
2416 
2417 /**
2418  *	pci_release_region - Release a PCI bar
2419  *	@pdev: PCI device whose resources were previously reserved by pci_request_region
2420  *	@bar: BAR to release
2421  *
2422  *	Releases the PCI I/O and memory resources previously reserved by a
2423  *	successful call to pci_request_region.  Call this function only
2424  *	after all use of the PCI regions has ceased.
2425  */
2426 void pci_release_region(struct pci_dev *pdev, int bar)
2427 {
2428 	struct pci_devres *dr;
2429 
2430 	if (pci_resource_len(pdev, bar) == 0)
2431 		return;
2432 	if (pci_resource_flags(pdev, bar) & IORESOURCE_IO)
2433 		release_region(pci_resource_start(pdev, bar),
2434 				pci_resource_len(pdev, bar));
2435 	else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM)
2436 		release_mem_region(pci_resource_start(pdev, bar),
2437 				pci_resource_len(pdev, bar));
2438 
2439 	dr = find_pci_dr(pdev);
2440 	if (dr)
2441 		dr->region_mask &= ~(1 << bar);
2442 }
2443 
2444 /**
2445  *	__pci_request_region - Reserved PCI I/O and memory resource
2446  *	@pdev: PCI device whose resources are to be reserved
2447  *	@bar: BAR to be reserved
2448  *	@res_name: Name to be associated with resource.
2449  *	@exclusive: whether the region access is exclusive or not
2450  *
2451  *	Mark the PCI region associated with PCI device @pdev BR @bar as
2452  *	being reserved by owner @res_name.  Do not access any
2453  *	address inside the PCI regions unless this call returns
2454  *	successfully.
2455  *
2456  *	If @exclusive is set, then the region is marked so that userspace
2457  *	is explicitly not allowed to map the resource via /dev/mem or
2458  *	sysfs MMIO access.
2459  *
2460  *	Returns 0 on success, or %EBUSY on error.  A warning
2461  *	message is also printed on failure.
2462  */
2463 static int __pci_request_region(struct pci_dev *pdev, int bar, const char *res_name,
2464 									int exclusive)
2465 {
2466 	struct pci_devres *dr;
2467 
2468 	if (pci_resource_len(pdev, bar) == 0)
2469 		return 0;
2470 
2471 	if (pci_resource_flags(pdev, bar) & IORESOURCE_IO) {
2472 		if (!request_region(pci_resource_start(pdev, bar),
2473 			    pci_resource_len(pdev, bar), res_name))
2474 			goto err_out;
2475 	}
2476 	else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM) {
2477 		if (!__request_mem_region(pci_resource_start(pdev, bar),
2478 					pci_resource_len(pdev, bar), res_name,
2479 					exclusive))
2480 			goto err_out;
2481 	}
2482 
2483 	dr = find_pci_dr(pdev);
2484 	if (dr)
2485 		dr->region_mask |= 1 << bar;
2486 
2487 	return 0;
2488 
2489 err_out:
2490 	dev_warn(&pdev->dev, "BAR %d: can't reserve %pR\n", bar,
2491 		 &pdev->resource[bar]);
2492 	return -EBUSY;
2493 }
2494 
2495 /**
2496  *	pci_request_region - Reserve PCI I/O and memory resource
2497  *	@pdev: PCI device whose resources are to be reserved
2498  *	@bar: BAR to be reserved
2499  *	@res_name: Name to be associated with resource
2500  *
2501  *	Mark the PCI region associated with PCI device @pdev BAR @bar as
2502  *	being reserved by owner @res_name.  Do not access any
2503  *	address inside the PCI regions unless this call returns
2504  *	successfully.
2505  *
2506  *	Returns 0 on success, or %EBUSY on error.  A warning
2507  *	message is also printed on failure.
2508  */
2509 int pci_request_region(struct pci_dev *pdev, int bar, const char *res_name)
2510 {
2511 	return __pci_request_region(pdev, bar, res_name, 0);
2512 }
2513 
2514 /**
2515  *	pci_request_region_exclusive - Reserved PCI I/O and memory resource
2516  *	@pdev: PCI device whose resources are to be reserved
2517  *	@bar: BAR to be reserved
2518  *	@res_name: Name to be associated with resource.
2519  *
2520  *	Mark the PCI region associated with PCI device @pdev BR @bar as
2521  *	being reserved by owner @res_name.  Do not access any
2522  *	address inside the PCI regions unless this call returns
2523  *	successfully.
2524  *
2525  *	Returns 0 on success, or %EBUSY on error.  A warning
2526  *	message is also printed on failure.
2527  *
2528  *	The key difference that _exclusive makes it that userspace is
2529  *	explicitly not allowed to map the resource via /dev/mem or
2530  *	sysfs.
2531  */
2532 int pci_request_region_exclusive(struct pci_dev *pdev, int bar, const char *res_name)
2533 {
2534 	return __pci_request_region(pdev, bar, res_name, IORESOURCE_EXCLUSIVE);
2535 }
2536 /**
2537  * pci_release_selected_regions - Release selected PCI I/O and memory resources
2538  * @pdev: PCI device whose resources were previously reserved
2539  * @bars: Bitmask of BARs to be released
2540  *
2541  * Release selected PCI I/O and memory resources previously reserved.
2542  * Call this function only after all use of the PCI regions has ceased.
2543  */
2544 void pci_release_selected_regions(struct pci_dev *pdev, int bars)
2545 {
2546 	int i;
2547 
2548 	for (i = 0; i < 6; i++)
2549 		if (bars & (1 << i))
2550 			pci_release_region(pdev, i);
2551 }
2552 
2553 static int __pci_request_selected_regions(struct pci_dev *pdev, int bars,
2554 				 const char *res_name, int excl)
2555 {
2556 	int i;
2557 
2558 	for (i = 0; i < 6; i++)
2559 		if (bars & (1 << i))
2560 			if (__pci_request_region(pdev, i, res_name, excl))
2561 				goto err_out;
2562 	return 0;
2563 
2564 err_out:
2565 	while(--i >= 0)
2566 		if (bars & (1 << i))
2567 			pci_release_region(pdev, i);
2568 
2569 	return -EBUSY;
2570 }
2571 
2572 
2573 /**
2574  * pci_request_selected_regions - Reserve selected PCI I/O and memory resources
2575  * @pdev: PCI device whose resources are to be reserved
2576  * @bars: Bitmask of BARs to be requested
2577  * @res_name: Name to be associated with resource
2578  */
2579 int pci_request_selected_regions(struct pci_dev *pdev, int bars,
2580 				 const char *res_name)
2581 {
2582 	return __pci_request_selected_regions(pdev, bars, res_name, 0);
2583 }
2584 
2585 int pci_request_selected_regions_exclusive(struct pci_dev *pdev,
2586 				 int bars, const char *res_name)
2587 {
2588 	return __pci_request_selected_regions(pdev, bars, res_name,
2589 			IORESOURCE_EXCLUSIVE);
2590 }
2591 
2592 /**
2593  *	pci_release_regions - Release reserved PCI I/O and memory resources
2594  *	@pdev: PCI device whose resources were previously reserved by pci_request_regions
2595  *
2596  *	Releases all PCI I/O and memory resources previously reserved by a
2597  *	successful call to pci_request_regions.  Call this function only
2598  *	after all use of the PCI regions has ceased.
2599  */
2600 
2601 void pci_release_regions(struct pci_dev *pdev)
2602 {
2603 	pci_release_selected_regions(pdev, (1 << 6) - 1);
2604 }
2605 
2606 /**
2607  *	pci_request_regions - Reserved PCI I/O and memory resources
2608  *	@pdev: PCI device whose resources are to be reserved
2609  *	@res_name: Name to be associated with resource.
2610  *
2611  *	Mark all PCI regions associated with PCI device @pdev as
2612  *	being reserved by owner @res_name.  Do not access any
2613  *	address inside the PCI regions unless this call returns
2614  *	successfully.
2615  *
2616  *	Returns 0 on success, or %EBUSY on error.  A warning
2617  *	message is also printed on failure.
2618  */
2619 int pci_request_regions(struct pci_dev *pdev, const char *res_name)
2620 {
2621 	return pci_request_selected_regions(pdev, ((1 << 6) - 1), res_name);
2622 }
2623 
2624 /**
2625  *	pci_request_regions_exclusive - Reserved PCI I/O and memory resources
2626  *	@pdev: PCI device whose resources are to be reserved
2627  *	@res_name: Name to be associated with resource.
2628  *
2629  *	Mark all PCI regions associated with PCI device @pdev as
2630  *	being reserved by owner @res_name.  Do not access any
2631  *	address inside the PCI regions unless this call returns
2632  *	successfully.
2633  *
2634  *	pci_request_regions_exclusive() will mark the region so that
2635  *	/dev/mem and the sysfs MMIO access will not be allowed.
2636  *
2637  *	Returns 0 on success, or %EBUSY on error.  A warning
2638  *	message is also printed on failure.
2639  */
2640 int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name)
2641 {
2642 	return pci_request_selected_regions_exclusive(pdev,
2643 					((1 << 6) - 1), res_name);
2644 }
2645 
2646 static void __pci_set_master(struct pci_dev *dev, bool enable)
2647 {
2648 	u16 old_cmd, cmd;
2649 
2650 	pci_read_config_word(dev, PCI_COMMAND, &old_cmd);
2651 	if (enable)
2652 		cmd = old_cmd | PCI_COMMAND_MASTER;
2653 	else
2654 		cmd = old_cmd & ~PCI_COMMAND_MASTER;
2655 	if (cmd != old_cmd) {
2656 		dev_dbg(&dev->dev, "%s bus mastering\n",
2657 			enable ? "enabling" : "disabling");
2658 		pci_write_config_word(dev, PCI_COMMAND, cmd);
2659 	}
2660 	dev->is_busmaster = enable;
2661 }
2662 
2663 /**
2664  * pcibios_setup - process "pci=" kernel boot arguments
2665  * @str: string used to pass in "pci=" kernel boot arguments
2666  *
2667  * Process kernel boot arguments.  This is the default implementation.
2668  * Architecture specific implementations can override this as necessary.
2669  */
2670 char * __weak __init pcibios_setup(char *str)
2671 {
2672 	return str;
2673 }
2674 
2675 /**
2676  * pcibios_set_master - enable PCI bus-mastering for device dev
2677  * @dev: the PCI device to enable
2678  *
2679  * Enables PCI bus-mastering for the device.  This is the default
2680  * implementation.  Architecture specific implementations can override
2681  * this if necessary.
2682  */
2683 void __weak pcibios_set_master(struct pci_dev *dev)
2684 {
2685 	u8 lat;
2686 
2687 	/* The latency timer doesn't apply to PCIe (either Type 0 or Type 1) */
2688 	if (pci_is_pcie(dev))
2689 		return;
2690 
2691 	pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat);
2692 	if (lat < 16)
2693 		lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency;
2694 	else if (lat > pcibios_max_latency)
2695 		lat = pcibios_max_latency;
2696 	else
2697 		return;
2698 
2699 	pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat);
2700 }
2701 
2702 /**
2703  * pci_set_master - enables bus-mastering for device dev
2704  * @dev: the PCI device to enable
2705  *
2706  * Enables bus-mastering on the device and calls pcibios_set_master()
2707  * to do the needed arch specific settings.
2708  */
2709 void pci_set_master(struct pci_dev *dev)
2710 {
2711 	__pci_set_master(dev, true);
2712 	pcibios_set_master(dev);
2713 }
2714 
2715 /**
2716  * pci_clear_master - disables bus-mastering for device dev
2717  * @dev: the PCI device to disable
2718  */
2719 void pci_clear_master(struct pci_dev *dev)
2720 {
2721 	__pci_set_master(dev, false);
2722 }
2723 
2724 /**
2725  * pci_set_cacheline_size - ensure the CACHE_LINE_SIZE register is programmed
2726  * @dev: the PCI device for which MWI is to be enabled
2727  *
2728  * Helper function for pci_set_mwi.
2729  * Originally copied from drivers/net/acenic.c.
2730  * Copyright 1998-2001 by Jes Sorensen, <jes@trained-monkey.org>.
2731  *
2732  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2733  */
2734 int pci_set_cacheline_size(struct pci_dev *dev)
2735 {
2736 	u8 cacheline_size;
2737 
2738 	if (!pci_cache_line_size)
2739 		return -EINVAL;
2740 
2741 	/* Validate current setting: the PCI_CACHE_LINE_SIZE must be
2742 	   equal to or multiple of the right value. */
2743 	pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
2744 	if (cacheline_size >= pci_cache_line_size &&
2745 	    (cacheline_size % pci_cache_line_size) == 0)
2746 		return 0;
2747 
2748 	/* Write the correct value. */
2749 	pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, pci_cache_line_size);
2750 	/* Read it back. */
2751 	pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
2752 	if (cacheline_size == pci_cache_line_size)
2753 		return 0;
2754 
2755 	dev_printk(KERN_DEBUG, &dev->dev, "cache line size of %d is not "
2756 		   "supported\n", pci_cache_line_size << 2);
2757 
2758 	return -EINVAL;
2759 }
2760 EXPORT_SYMBOL_GPL(pci_set_cacheline_size);
2761 
2762 #ifdef PCI_DISABLE_MWI
2763 int pci_set_mwi(struct pci_dev *dev)
2764 {
2765 	return 0;
2766 }
2767 
2768 int pci_try_set_mwi(struct pci_dev *dev)
2769 {
2770 	return 0;
2771 }
2772 
2773 void pci_clear_mwi(struct pci_dev *dev)
2774 {
2775 }
2776 
2777 #else
2778 
2779 /**
2780  * pci_set_mwi - enables memory-write-invalidate PCI transaction
2781  * @dev: the PCI device for which MWI is enabled
2782  *
2783  * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND.
2784  *
2785  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2786  */
2787 int
2788 pci_set_mwi(struct pci_dev *dev)
2789 {
2790 	int rc;
2791 	u16 cmd;
2792 
2793 	rc = pci_set_cacheline_size(dev);
2794 	if (rc)
2795 		return rc;
2796 
2797 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
2798 	if (! (cmd & PCI_COMMAND_INVALIDATE)) {
2799 		dev_dbg(&dev->dev, "enabling Mem-Wr-Inval\n");
2800 		cmd |= PCI_COMMAND_INVALIDATE;
2801 		pci_write_config_word(dev, PCI_COMMAND, cmd);
2802 	}
2803 
2804 	return 0;
2805 }
2806 
2807 /**
2808  * pci_try_set_mwi - enables memory-write-invalidate PCI transaction
2809  * @dev: the PCI device for which MWI is enabled
2810  *
2811  * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND.
2812  * Callers are not required to check the return value.
2813  *
2814  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2815  */
2816 int pci_try_set_mwi(struct pci_dev *dev)
2817 {
2818 	int rc = pci_set_mwi(dev);
2819 	return rc;
2820 }
2821 
2822 /**
2823  * pci_clear_mwi - disables Memory-Write-Invalidate for device dev
2824  * @dev: the PCI device to disable
2825  *
2826  * Disables PCI Memory-Write-Invalidate transaction on the device
2827  */
2828 void
2829 pci_clear_mwi(struct pci_dev *dev)
2830 {
2831 	u16 cmd;
2832 
2833 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
2834 	if (cmd & PCI_COMMAND_INVALIDATE) {
2835 		cmd &= ~PCI_COMMAND_INVALIDATE;
2836 		pci_write_config_word(dev, PCI_COMMAND, cmd);
2837 	}
2838 }
2839 #endif /* ! PCI_DISABLE_MWI */
2840 
2841 /**
2842  * pci_intx - enables/disables PCI INTx for device dev
2843  * @pdev: the PCI device to operate on
2844  * @enable: boolean: whether to enable or disable PCI INTx
2845  *
2846  * Enables/disables PCI INTx for device dev
2847  */
2848 void
2849 pci_intx(struct pci_dev *pdev, int enable)
2850 {
2851 	u16 pci_command, new;
2852 
2853 	pci_read_config_word(pdev, PCI_COMMAND, &pci_command);
2854 
2855 	if (enable) {
2856 		new = pci_command & ~PCI_COMMAND_INTX_DISABLE;
2857 	} else {
2858 		new = pci_command | PCI_COMMAND_INTX_DISABLE;
2859 	}
2860 
2861 	if (new != pci_command) {
2862 		struct pci_devres *dr;
2863 
2864 		pci_write_config_word(pdev, PCI_COMMAND, new);
2865 
2866 		dr = find_pci_dr(pdev);
2867 		if (dr && !dr->restore_intx) {
2868 			dr->restore_intx = 1;
2869 			dr->orig_intx = !enable;
2870 		}
2871 	}
2872 }
2873 
2874 /**
2875  * pci_intx_mask_supported - probe for INTx masking support
2876  * @dev: the PCI device to operate on
2877  *
2878  * Check if the device dev support INTx masking via the config space
2879  * command word.
2880  */
2881 bool pci_intx_mask_supported(struct pci_dev *dev)
2882 {
2883 	bool mask_supported = false;
2884 	u16 orig, new;
2885 
2886 	if (dev->broken_intx_masking)
2887 		return false;
2888 
2889 	pci_cfg_access_lock(dev);
2890 
2891 	pci_read_config_word(dev, PCI_COMMAND, &orig);
2892 	pci_write_config_word(dev, PCI_COMMAND,
2893 			      orig ^ PCI_COMMAND_INTX_DISABLE);
2894 	pci_read_config_word(dev, PCI_COMMAND, &new);
2895 
2896 	/*
2897 	 * There's no way to protect against hardware bugs or detect them
2898 	 * reliably, but as long as we know what the value should be, let's
2899 	 * go ahead and check it.
2900 	 */
2901 	if ((new ^ orig) & ~PCI_COMMAND_INTX_DISABLE) {
2902 		dev_err(&dev->dev, "Command register changed from "
2903 			"0x%x to 0x%x: driver or hardware bug?\n", orig, new);
2904 	} else if ((new ^ orig) & PCI_COMMAND_INTX_DISABLE) {
2905 		mask_supported = true;
2906 		pci_write_config_word(dev, PCI_COMMAND, orig);
2907 	}
2908 
2909 	pci_cfg_access_unlock(dev);
2910 	return mask_supported;
2911 }
2912 EXPORT_SYMBOL_GPL(pci_intx_mask_supported);
2913 
2914 static bool pci_check_and_set_intx_mask(struct pci_dev *dev, bool mask)
2915 {
2916 	struct pci_bus *bus = dev->bus;
2917 	bool mask_updated = true;
2918 	u32 cmd_status_dword;
2919 	u16 origcmd, newcmd;
2920 	unsigned long flags;
2921 	bool irq_pending;
2922 
2923 	/*
2924 	 * We do a single dword read to retrieve both command and status.
2925 	 * Document assumptions that make this possible.
2926 	 */
2927 	BUILD_BUG_ON(PCI_COMMAND % 4);
2928 	BUILD_BUG_ON(PCI_COMMAND + 2 != PCI_STATUS);
2929 
2930 	raw_spin_lock_irqsave(&pci_lock, flags);
2931 
2932 	bus->ops->read(bus, dev->devfn, PCI_COMMAND, 4, &cmd_status_dword);
2933 
2934 	irq_pending = (cmd_status_dword >> 16) & PCI_STATUS_INTERRUPT;
2935 
2936 	/*
2937 	 * Check interrupt status register to see whether our device
2938 	 * triggered the interrupt (when masking) or the next IRQ is
2939 	 * already pending (when unmasking).
2940 	 */
2941 	if (mask != irq_pending) {
2942 		mask_updated = false;
2943 		goto done;
2944 	}
2945 
2946 	origcmd = cmd_status_dword;
2947 	newcmd = origcmd & ~PCI_COMMAND_INTX_DISABLE;
2948 	if (mask)
2949 		newcmd |= PCI_COMMAND_INTX_DISABLE;
2950 	if (newcmd != origcmd)
2951 		bus->ops->write(bus, dev->devfn, PCI_COMMAND, 2, newcmd);
2952 
2953 done:
2954 	raw_spin_unlock_irqrestore(&pci_lock, flags);
2955 
2956 	return mask_updated;
2957 }
2958 
2959 /**
2960  * pci_check_and_mask_intx - mask INTx on pending interrupt
2961  * @dev: the PCI device to operate on
2962  *
2963  * Check if the device dev has its INTx line asserted, mask it and
2964  * return true in that case. False is returned if not interrupt was
2965  * pending.
2966  */
2967 bool pci_check_and_mask_intx(struct pci_dev *dev)
2968 {
2969 	return pci_check_and_set_intx_mask(dev, true);
2970 }
2971 EXPORT_SYMBOL_GPL(pci_check_and_mask_intx);
2972 
2973 /**
2974  * pci_check_and_unmask_intx - unmask INTx if no interrupt is pending
2975  * @dev: the PCI device to operate on
2976  *
2977  * Check if the device dev has its INTx line asserted, unmask it if not
2978  * and return true. False is returned and the mask remains active if
2979  * there was still an interrupt pending.
2980  */
2981 bool pci_check_and_unmask_intx(struct pci_dev *dev)
2982 {
2983 	return pci_check_and_set_intx_mask(dev, false);
2984 }
2985 EXPORT_SYMBOL_GPL(pci_check_and_unmask_intx);
2986 
2987 /**
2988  * pci_msi_off - disables any MSI or MSI-X capabilities
2989  * @dev: the PCI device to operate on
2990  *
2991  * If you want to use MSI, see pci_enable_msi() and friends.
2992  * This is a lower-level primitive that allows us to disable
2993  * MSI operation at the device level.
2994  */
2995 void pci_msi_off(struct pci_dev *dev)
2996 {
2997 	int pos;
2998 	u16 control;
2999 
3000 	/*
3001 	 * This looks like it could go in msi.c, but we need it even when
3002 	 * CONFIG_PCI_MSI=n.  For the same reason, we can't use
3003 	 * dev->msi_cap or dev->msix_cap here.
3004 	 */
3005 	pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
3006 	if (pos) {
3007 		pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control);
3008 		control &= ~PCI_MSI_FLAGS_ENABLE;
3009 		pci_write_config_word(dev, pos + PCI_MSI_FLAGS, control);
3010 	}
3011 	pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
3012 	if (pos) {
3013 		pci_read_config_word(dev, pos + PCI_MSIX_FLAGS, &control);
3014 		control &= ~PCI_MSIX_FLAGS_ENABLE;
3015 		pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control);
3016 	}
3017 }
3018 EXPORT_SYMBOL_GPL(pci_msi_off);
3019 
3020 int pci_set_dma_max_seg_size(struct pci_dev *dev, unsigned int size)
3021 {
3022 	return dma_set_max_seg_size(&dev->dev, size);
3023 }
3024 EXPORT_SYMBOL(pci_set_dma_max_seg_size);
3025 
3026 int pci_set_dma_seg_boundary(struct pci_dev *dev, unsigned long mask)
3027 {
3028 	return dma_set_seg_boundary(&dev->dev, mask);
3029 }
3030 EXPORT_SYMBOL(pci_set_dma_seg_boundary);
3031 
3032 /**
3033  * pci_wait_for_pending_transaction - waits for pending transaction
3034  * @dev: the PCI device to operate on
3035  *
3036  * Return 0 if transaction is pending 1 otherwise.
3037  */
3038 int pci_wait_for_pending_transaction(struct pci_dev *dev)
3039 {
3040 	if (!pci_is_pcie(dev))
3041 		return 1;
3042 
3043 	return pci_wait_for_pending(dev, PCI_EXP_DEVSTA, PCI_EXP_DEVSTA_TRPND);
3044 }
3045 EXPORT_SYMBOL(pci_wait_for_pending_transaction);
3046 
3047 static int pcie_flr(struct pci_dev *dev, int probe)
3048 {
3049 	u32 cap;
3050 
3051 	pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap);
3052 	if (!(cap & PCI_EXP_DEVCAP_FLR))
3053 		return -ENOTTY;
3054 
3055 	if (probe)
3056 		return 0;
3057 
3058 	if (!pci_wait_for_pending_transaction(dev))
3059 		dev_err(&dev->dev, "transaction is not cleared; proceeding with reset anyway\n");
3060 
3061 	pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR);
3062 
3063 	msleep(100);
3064 
3065 	return 0;
3066 }
3067 
3068 static int pci_af_flr(struct pci_dev *dev, int probe)
3069 {
3070 	int pos;
3071 	u8 cap;
3072 
3073 	pos = pci_find_capability(dev, PCI_CAP_ID_AF);
3074 	if (!pos)
3075 		return -ENOTTY;
3076 
3077 	pci_read_config_byte(dev, pos + PCI_AF_CAP, &cap);
3078 	if (!(cap & PCI_AF_CAP_TP) || !(cap & PCI_AF_CAP_FLR))
3079 		return -ENOTTY;
3080 
3081 	if (probe)
3082 		return 0;
3083 
3084 	/* Wait for Transaction Pending bit clean */
3085 	if (pci_wait_for_pending(dev, PCI_AF_STATUS, PCI_AF_STATUS_TP))
3086 		goto clear;
3087 
3088 	dev_err(&dev->dev, "transaction is not cleared; "
3089 			"proceeding with reset anyway\n");
3090 
3091 clear:
3092 	pci_write_config_byte(dev, pos + PCI_AF_CTRL, PCI_AF_CTRL_FLR);
3093 	msleep(100);
3094 
3095 	return 0;
3096 }
3097 
3098 /**
3099  * pci_pm_reset - Put device into PCI_D3 and back into PCI_D0.
3100  * @dev: Device to reset.
3101  * @probe: If set, only check if the device can be reset this way.
3102  *
3103  * If @dev supports native PCI PM and its PCI_PM_CTRL_NO_SOFT_RESET flag is
3104  * unset, it will be reinitialized internally when going from PCI_D3hot to
3105  * PCI_D0.  If that's the case and the device is not in a low-power state
3106  * already, force it into PCI_D3hot and back to PCI_D0, causing it to be reset.
3107  *
3108  * NOTE: This causes the caller to sleep for twice the device power transition
3109  * cooldown period, which for the D0->D3hot and D3hot->D0 transitions is 10 ms
3110  * by default (i.e. unless the @dev's d3_delay field has a different value).
3111  * Moreover, only devices in D0 can be reset by this function.
3112  */
3113 static int pci_pm_reset(struct pci_dev *dev, int probe)
3114 {
3115 	u16 csr;
3116 
3117 	if (!dev->pm_cap)
3118 		return -ENOTTY;
3119 
3120 	pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &csr);
3121 	if (csr & PCI_PM_CTRL_NO_SOFT_RESET)
3122 		return -ENOTTY;
3123 
3124 	if (probe)
3125 		return 0;
3126 
3127 	if (dev->current_state != PCI_D0)
3128 		return -EINVAL;
3129 
3130 	csr &= ~PCI_PM_CTRL_STATE_MASK;
3131 	csr |= PCI_D3hot;
3132 	pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);
3133 	pci_dev_d3_sleep(dev);
3134 
3135 	csr &= ~PCI_PM_CTRL_STATE_MASK;
3136 	csr |= PCI_D0;
3137 	pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);
3138 	pci_dev_d3_sleep(dev);
3139 
3140 	return 0;
3141 }
3142 
3143 /**
3144  * pci_reset_bridge_secondary_bus - Reset the secondary bus on a PCI bridge.
3145  * @dev: Bridge device
3146  *
3147  * Use the bridge control register to assert reset on the secondary bus.
3148  * Devices on the secondary bus are left in power-on state.
3149  */
3150 void pci_reset_bridge_secondary_bus(struct pci_dev *dev)
3151 {
3152 	u16 ctrl;
3153 
3154 	pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &ctrl);
3155 	ctrl |= PCI_BRIDGE_CTL_BUS_RESET;
3156 	pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl);
3157 	/*
3158 	 * PCI spec v3.0 7.6.4.2 requires minimum Trst of 1ms.  Double
3159 	 * this to 2ms to ensure that we meet the minimum requirement.
3160 	 */
3161 	msleep(2);
3162 
3163 	ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET;
3164 	pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl);
3165 
3166 	/*
3167 	 * Trhfa for conventional PCI is 2^25 clock cycles.
3168 	 * Assuming a minimum 33MHz clock this results in a 1s
3169 	 * delay before we can consider subordinate devices to
3170 	 * be re-initialized.  PCIe has some ways to shorten this,
3171 	 * but we don't make use of them yet.
3172 	 */
3173 	ssleep(1);
3174 }
3175 EXPORT_SYMBOL_GPL(pci_reset_bridge_secondary_bus);
3176 
3177 static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
3178 {
3179 	struct pci_dev *pdev;
3180 
3181 	if (pci_is_root_bus(dev->bus) || dev->subordinate || !dev->bus->self)
3182 		return -ENOTTY;
3183 
3184 	list_for_each_entry(pdev, &dev->bus->devices, bus_list)
3185 		if (pdev != dev)
3186 			return -ENOTTY;
3187 
3188 	if (probe)
3189 		return 0;
3190 
3191 	pci_reset_bridge_secondary_bus(dev->bus->self);
3192 
3193 	return 0;
3194 }
3195 
3196 static int pci_reset_hotplug_slot(struct hotplug_slot *hotplug, int probe)
3197 {
3198 	int rc = -ENOTTY;
3199 
3200 	if (!hotplug || !try_module_get(hotplug->ops->owner))
3201 		return rc;
3202 
3203 	if (hotplug->ops->reset_slot)
3204 		rc = hotplug->ops->reset_slot(hotplug, probe);
3205 
3206 	module_put(hotplug->ops->owner);
3207 
3208 	return rc;
3209 }
3210 
3211 static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe)
3212 {
3213 	struct pci_dev *pdev;
3214 
3215 	if (dev->subordinate || !dev->slot)
3216 		return -ENOTTY;
3217 
3218 	list_for_each_entry(pdev, &dev->bus->devices, bus_list)
3219 		if (pdev != dev && pdev->slot == dev->slot)
3220 			return -ENOTTY;
3221 
3222 	return pci_reset_hotplug_slot(dev->slot->hotplug, probe);
3223 }
3224 
3225 static int __pci_dev_reset(struct pci_dev *dev, int probe)
3226 {
3227 	int rc;
3228 
3229 	might_sleep();
3230 
3231 	rc = pci_dev_specific_reset(dev, probe);
3232 	if (rc != -ENOTTY)
3233 		goto done;
3234 
3235 	rc = pcie_flr(dev, probe);
3236 	if (rc != -ENOTTY)
3237 		goto done;
3238 
3239 	rc = pci_af_flr(dev, probe);
3240 	if (rc != -ENOTTY)
3241 		goto done;
3242 
3243 	rc = pci_pm_reset(dev, probe);
3244 	if (rc != -ENOTTY)
3245 		goto done;
3246 
3247 	rc = pci_dev_reset_slot_function(dev, probe);
3248 	if (rc != -ENOTTY)
3249 		goto done;
3250 
3251 	rc = pci_parent_bus_reset(dev, probe);
3252 done:
3253 	return rc;
3254 }
3255 
3256 static void pci_dev_lock(struct pci_dev *dev)
3257 {
3258 	pci_cfg_access_lock(dev);
3259 	/* block PM suspend, driver probe, etc. */
3260 	device_lock(&dev->dev);
3261 }
3262 
3263 /* Return 1 on successful lock, 0 on contention */
3264 static int pci_dev_trylock(struct pci_dev *dev)
3265 {
3266 	if (pci_cfg_access_trylock(dev)) {
3267 		if (device_trylock(&dev->dev))
3268 			return 1;
3269 		pci_cfg_access_unlock(dev);
3270 	}
3271 
3272 	return 0;
3273 }
3274 
3275 static void pci_dev_unlock(struct pci_dev *dev)
3276 {
3277 	device_unlock(&dev->dev);
3278 	pci_cfg_access_unlock(dev);
3279 }
3280 
3281 static void pci_dev_save_and_disable(struct pci_dev *dev)
3282 {
3283 	/*
3284 	 * Wake-up device prior to save.  PM registers default to D0 after
3285 	 * reset and a simple register restore doesn't reliably return
3286 	 * to a non-D0 state anyway.
3287 	 */
3288 	pci_set_power_state(dev, PCI_D0);
3289 
3290 	pci_save_state(dev);
3291 	/*
3292 	 * Disable the device by clearing the Command register, except for
3293 	 * INTx-disable which is set.  This not only disables MMIO and I/O port
3294 	 * BARs, but also prevents the device from being Bus Master, preventing
3295 	 * DMA from the device including MSI/MSI-X interrupts.  For PCI 2.3
3296 	 * compliant devices, INTx-disable prevents legacy interrupts.
3297 	 */
3298 	pci_write_config_word(dev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
3299 }
3300 
3301 static void pci_dev_restore(struct pci_dev *dev)
3302 {
3303 	pci_restore_state(dev);
3304 }
3305 
3306 static int pci_dev_reset(struct pci_dev *dev, int probe)
3307 {
3308 	int rc;
3309 
3310 	if (!probe)
3311 		pci_dev_lock(dev);
3312 
3313 	rc = __pci_dev_reset(dev, probe);
3314 
3315 	if (!probe)
3316 		pci_dev_unlock(dev);
3317 
3318 	return rc;
3319 }
3320 /**
3321  * __pci_reset_function - reset a PCI device function
3322  * @dev: PCI device to reset
3323  *
3324  * Some devices allow an individual function to be reset without affecting
3325  * other functions in the same device.  The PCI device must be responsive
3326  * to PCI config space in order to use this function.
3327  *
3328  * The device function is presumed to be unused when this function is called.
3329  * Resetting the device will make the contents of PCI configuration space
3330  * random, so any caller of this must be prepared to reinitialise the
3331  * device including MSI, bus mastering, BARs, decoding IO and memory spaces,
3332  * etc.
3333  *
3334  * Returns 0 if the device function was successfully reset or negative if the
3335  * device doesn't support resetting a single function.
3336  */
3337 int __pci_reset_function(struct pci_dev *dev)
3338 {
3339 	return pci_dev_reset(dev, 0);
3340 }
3341 EXPORT_SYMBOL_GPL(__pci_reset_function);
3342 
3343 /**
3344  * __pci_reset_function_locked - reset a PCI device function while holding
3345  * the @dev mutex lock.
3346  * @dev: PCI device to reset
3347  *
3348  * Some devices allow an individual function to be reset without affecting
3349  * other functions in the same device.  The PCI device must be responsive
3350  * to PCI config space in order to use this function.
3351  *
3352  * The device function is presumed to be unused and the caller is holding
3353  * the device mutex lock when this function is called.
3354  * Resetting the device will make the contents of PCI configuration space
3355  * random, so any caller of this must be prepared to reinitialise the
3356  * device including MSI, bus mastering, BARs, decoding IO and memory spaces,
3357  * etc.
3358  *
3359  * Returns 0 if the device function was successfully reset or negative if the
3360  * device doesn't support resetting a single function.
3361  */
3362 int __pci_reset_function_locked(struct pci_dev *dev)
3363 {
3364 	return __pci_dev_reset(dev, 0);
3365 }
3366 EXPORT_SYMBOL_GPL(__pci_reset_function_locked);
3367 
3368 /**
3369  * pci_probe_reset_function - check whether the device can be safely reset
3370  * @dev: PCI device to reset
3371  *
3372  * Some devices allow an individual function to be reset without affecting
3373  * other functions in the same device.  The PCI device must be responsive
3374  * to PCI config space in order to use this function.
3375  *
3376  * Returns 0 if the device function can be reset or negative if the
3377  * device doesn't support resetting a single function.
3378  */
3379 int pci_probe_reset_function(struct pci_dev *dev)
3380 {
3381 	return pci_dev_reset(dev, 1);
3382 }
3383 
3384 /**
3385  * pci_reset_function - quiesce and reset a PCI device function
3386  * @dev: PCI device to reset
3387  *
3388  * Some devices allow an individual function to be reset without affecting
3389  * other functions in the same device.  The PCI device must be responsive
3390  * to PCI config space in order to use this function.
3391  *
3392  * This function does not just reset the PCI portion of a device, but
3393  * clears all the state associated with the device.  This function differs
3394  * from __pci_reset_function in that it saves and restores device state
3395  * over the reset.
3396  *
3397  * Returns 0 if the device function was successfully reset or negative if the
3398  * device doesn't support resetting a single function.
3399  */
3400 int pci_reset_function(struct pci_dev *dev)
3401 {
3402 	int rc;
3403 
3404 	rc = pci_dev_reset(dev, 1);
3405 	if (rc)
3406 		return rc;
3407 
3408 	pci_dev_save_and_disable(dev);
3409 
3410 	rc = pci_dev_reset(dev, 0);
3411 
3412 	pci_dev_restore(dev);
3413 
3414 	return rc;
3415 }
3416 EXPORT_SYMBOL_GPL(pci_reset_function);
3417 
3418 /**
3419  * pci_try_reset_function - quiesce and reset a PCI device function
3420  * @dev: PCI device to reset
3421  *
3422  * Same as above, except return -EAGAIN if unable to lock device.
3423  */
3424 int pci_try_reset_function(struct pci_dev *dev)
3425 {
3426 	int rc;
3427 
3428 	rc = pci_dev_reset(dev, 1);
3429 	if (rc)
3430 		return rc;
3431 
3432 	pci_dev_save_and_disable(dev);
3433 
3434 	if (pci_dev_trylock(dev)) {
3435 		rc = __pci_dev_reset(dev, 0);
3436 		pci_dev_unlock(dev);
3437 	} else
3438 		rc = -EAGAIN;
3439 
3440 	pci_dev_restore(dev);
3441 
3442 	return rc;
3443 }
3444 EXPORT_SYMBOL_GPL(pci_try_reset_function);
3445 
3446 /* Lock devices from the top of the tree down */
3447 static void pci_bus_lock(struct pci_bus *bus)
3448 {
3449 	struct pci_dev *dev;
3450 
3451 	list_for_each_entry(dev, &bus->devices, bus_list) {
3452 		pci_dev_lock(dev);
3453 		if (dev->subordinate)
3454 			pci_bus_lock(dev->subordinate);
3455 	}
3456 }
3457 
3458 /* Unlock devices from the bottom of the tree up */
3459 static void pci_bus_unlock(struct pci_bus *bus)
3460 {
3461 	struct pci_dev *dev;
3462 
3463 	list_for_each_entry(dev, &bus->devices, bus_list) {
3464 		if (dev->subordinate)
3465 			pci_bus_unlock(dev->subordinate);
3466 		pci_dev_unlock(dev);
3467 	}
3468 }
3469 
3470 /* Return 1 on successful lock, 0 on contention */
3471 static int pci_bus_trylock(struct pci_bus *bus)
3472 {
3473 	struct pci_dev *dev;
3474 
3475 	list_for_each_entry(dev, &bus->devices, bus_list) {
3476 		if (!pci_dev_trylock(dev))
3477 			goto unlock;
3478 		if (dev->subordinate) {
3479 			if (!pci_bus_trylock(dev->subordinate)) {
3480 				pci_dev_unlock(dev);
3481 				goto unlock;
3482 			}
3483 		}
3484 	}
3485 	return 1;
3486 
3487 unlock:
3488 	list_for_each_entry_continue_reverse(dev, &bus->devices, bus_list) {
3489 		if (dev->subordinate)
3490 			pci_bus_unlock(dev->subordinate);
3491 		pci_dev_unlock(dev);
3492 	}
3493 	return 0;
3494 }
3495 
3496 /* Lock devices from the top of the tree down */
3497 static void pci_slot_lock(struct pci_slot *slot)
3498 {
3499 	struct pci_dev *dev;
3500 
3501 	list_for_each_entry(dev, &slot->bus->devices, bus_list) {
3502 		if (!dev->slot || dev->slot != slot)
3503 			continue;
3504 		pci_dev_lock(dev);
3505 		if (dev->subordinate)
3506 			pci_bus_lock(dev->subordinate);
3507 	}
3508 }
3509 
3510 /* Unlock devices from the bottom of the tree up */
3511 static void pci_slot_unlock(struct pci_slot *slot)
3512 {
3513 	struct pci_dev *dev;
3514 
3515 	list_for_each_entry(dev, &slot->bus->devices, bus_list) {
3516 		if (!dev->slot || dev->slot != slot)
3517 			continue;
3518 		if (dev->subordinate)
3519 			pci_bus_unlock(dev->subordinate);
3520 		pci_dev_unlock(dev);
3521 	}
3522 }
3523 
3524 /* Return 1 on successful lock, 0 on contention */
3525 static int pci_slot_trylock(struct pci_slot *slot)
3526 {
3527 	struct pci_dev *dev;
3528 
3529 	list_for_each_entry(dev, &slot->bus->devices, bus_list) {
3530 		if (!dev->slot || dev->slot != slot)
3531 			continue;
3532 		if (!pci_dev_trylock(dev))
3533 			goto unlock;
3534 		if (dev->subordinate) {
3535 			if (!pci_bus_trylock(dev->subordinate)) {
3536 				pci_dev_unlock(dev);
3537 				goto unlock;
3538 			}
3539 		}
3540 	}
3541 	return 1;
3542 
3543 unlock:
3544 	list_for_each_entry_continue_reverse(dev,
3545 					     &slot->bus->devices, bus_list) {
3546 		if (!dev->slot || dev->slot != slot)
3547 			continue;
3548 		if (dev->subordinate)
3549 			pci_bus_unlock(dev->subordinate);
3550 		pci_dev_unlock(dev);
3551 	}
3552 	return 0;
3553 }
3554 
3555 /* Save and disable devices from the top of the tree down */
3556 static void pci_bus_save_and_disable(struct pci_bus *bus)
3557 {
3558 	struct pci_dev *dev;
3559 
3560 	list_for_each_entry(dev, &bus->devices, bus_list) {
3561 		pci_dev_save_and_disable(dev);
3562 		if (dev->subordinate)
3563 			pci_bus_save_and_disable(dev->subordinate);
3564 	}
3565 }
3566 
3567 /*
3568  * Restore devices from top of the tree down - parent bridges need to be
3569  * restored before we can get to subordinate devices.
3570  */
3571 static void pci_bus_restore(struct pci_bus *bus)
3572 {
3573 	struct pci_dev *dev;
3574 
3575 	list_for_each_entry(dev, &bus->devices, bus_list) {
3576 		pci_dev_restore(dev);
3577 		if (dev->subordinate)
3578 			pci_bus_restore(dev->subordinate);
3579 	}
3580 }
3581 
3582 /* Save and disable devices from the top of the tree down */
3583 static void pci_slot_save_and_disable(struct pci_slot *slot)
3584 {
3585 	struct pci_dev *dev;
3586 
3587 	list_for_each_entry(dev, &slot->bus->devices, bus_list) {
3588 		if (!dev->slot || dev->slot != slot)
3589 			continue;
3590 		pci_dev_save_and_disable(dev);
3591 		if (dev->subordinate)
3592 			pci_bus_save_and_disable(dev->subordinate);
3593 	}
3594 }
3595 
3596 /*
3597  * Restore devices from top of the tree down - parent bridges need to be
3598  * restored before we can get to subordinate devices.
3599  */
3600 static void pci_slot_restore(struct pci_slot *slot)
3601 {
3602 	struct pci_dev *dev;
3603 
3604 	list_for_each_entry(dev, &slot->bus->devices, bus_list) {
3605 		if (!dev->slot || dev->slot != slot)
3606 			continue;
3607 		pci_dev_restore(dev);
3608 		if (dev->subordinate)
3609 			pci_bus_restore(dev->subordinate);
3610 	}
3611 }
3612 
3613 static int pci_slot_reset(struct pci_slot *slot, int probe)
3614 {
3615 	int rc;
3616 
3617 	if (!slot)
3618 		return -ENOTTY;
3619 
3620 	if (!probe)
3621 		pci_slot_lock(slot);
3622 
3623 	might_sleep();
3624 
3625 	rc = pci_reset_hotplug_slot(slot->hotplug, probe);
3626 
3627 	if (!probe)
3628 		pci_slot_unlock(slot);
3629 
3630 	return rc;
3631 }
3632 
3633 /**
3634  * pci_probe_reset_slot - probe whether a PCI slot can be reset
3635  * @slot: PCI slot to probe
3636  *
3637  * Return 0 if slot can be reset, negative if a slot reset is not supported.
3638  */
3639 int pci_probe_reset_slot(struct pci_slot *slot)
3640 {
3641 	return pci_slot_reset(slot, 1);
3642 }
3643 EXPORT_SYMBOL_GPL(pci_probe_reset_slot);
3644 
3645 /**
3646  * pci_reset_slot - reset a PCI slot
3647  * @slot: PCI slot to reset
3648  *
3649  * A PCI bus may host multiple slots, each slot may support a reset mechanism
3650  * independent of other slots.  For instance, some slots may support slot power
3651  * control.  In the case of a 1:1 bus to slot architecture, this function may
3652  * wrap the bus reset to avoid spurious slot related events such as hotplug.
3653  * Generally a slot reset should be attempted before a bus reset.  All of the
3654  * function of the slot and any subordinate buses behind the slot are reset
3655  * through this function.  PCI config space of all devices in the slot and
3656  * behind the slot is saved before and restored after reset.
3657  *
3658  * Return 0 on success, non-zero on error.
3659  */
3660 int pci_reset_slot(struct pci_slot *slot)
3661 {
3662 	int rc;
3663 
3664 	rc = pci_slot_reset(slot, 1);
3665 	if (rc)
3666 		return rc;
3667 
3668 	pci_slot_save_and_disable(slot);
3669 
3670 	rc = pci_slot_reset(slot, 0);
3671 
3672 	pci_slot_restore(slot);
3673 
3674 	return rc;
3675 }
3676 EXPORT_SYMBOL_GPL(pci_reset_slot);
3677 
3678 /**
3679  * pci_try_reset_slot - Try to reset a PCI slot
3680  * @slot: PCI slot to reset
3681  *
3682  * Same as above except return -EAGAIN if the slot cannot be locked
3683  */
3684 int pci_try_reset_slot(struct pci_slot *slot)
3685 {
3686 	int rc;
3687 
3688 	rc = pci_slot_reset(slot, 1);
3689 	if (rc)
3690 		return rc;
3691 
3692 	pci_slot_save_and_disable(slot);
3693 
3694 	if (pci_slot_trylock(slot)) {
3695 		might_sleep();
3696 		rc = pci_reset_hotplug_slot(slot->hotplug, 0);
3697 		pci_slot_unlock(slot);
3698 	} else
3699 		rc = -EAGAIN;
3700 
3701 	pci_slot_restore(slot);
3702 
3703 	return rc;
3704 }
3705 EXPORT_SYMBOL_GPL(pci_try_reset_slot);
3706 
3707 static int pci_bus_reset(struct pci_bus *bus, int probe)
3708 {
3709 	if (!bus->self)
3710 		return -ENOTTY;
3711 
3712 	if (probe)
3713 		return 0;
3714 
3715 	pci_bus_lock(bus);
3716 
3717 	might_sleep();
3718 
3719 	pci_reset_bridge_secondary_bus(bus->self);
3720 
3721 	pci_bus_unlock(bus);
3722 
3723 	return 0;
3724 }
3725 
3726 /**
3727  * pci_probe_reset_bus - probe whether a PCI bus can be reset
3728  * @bus: PCI bus to probe
3729  *
3730  * Return 0 if bus can be reset, negative if a bus reset is not supported.
3731  */
3732 int pci_probe_reset_bus(struct pci_bus *bus)
3733 {
3734 	return pci_bus_reset(bus, 1);
3735 }
3736 EXPORT_SYMBOL_GPL(pci_probe_reset_bus);
3737 
3738 /**
3739  * pci_reset_bus - reset a PCI bus
3740  * @bus: top level PCI bus to reset
3741  *
3742  * Do a bus reset on the given bus and any subordinate buses, saving
3743  * and restoring state of all devices.
3744  *
3745  * Return 0 on success, non-zero on error.
3746  */
3747 int pci_reset_bus(struct pci_bus *bus)
3748 {
3749 	int rc;
3750 
3751 	rc = pci_bus_reset(bus, 1);
3752 	if (rc)
3753 		return rc;
3754 
3755 	pci_bus_save_and_disable(bus);
3756 
3757 	rc = pci_bus_reset(bus, 0);
3758 
3759 	pci_bus_restore(bus);
3760 
3761 	return rc;
3762 }
3763 EXPORT_SYMBOL_GPL(pci_reset_bus);
3764 
3765 /**
3766  * pci_try_reset_bus - Try to reset a PCI bus
3767  * @bus: top level PCI bus to reset
3768  *
3769  * Same as above except return -EAGAIN if the bus cannot be locked
3770  */
3771 int pci_try_reset_bus(struct pci_bus *bus)
3772 {
3773 	int rc;
3774 
3775 	rc = pci_bus_reset(bus, 1);
3776 	if (rc)
3777 		return rc;
3778 
3779 	pci_bus_save_and_disable(bus);
3780 
3781 	if (pci_bus_trylock(bus)) {
3782 		might_sleep();
3783 		pci_reset_bridge_secondary_bus(bus->self);
3784 		pci_bus_unlock(bus);
3785 	} else
3786 		rc = -EAGAIN;
3787 
3788 	pci_bus_restore(bus);
3789 
3790 	return rc;
3791 }
3792 EXPORT_SYMBOL_GPL(pci_try_reset_bus);
3793 
3794 /**
3795  * pcix_get_max_mmrbc - get PCI-X maximum designed memory read byte count
3796  * @dev: PCI device to query
3797  *
3798  * Returns mmrbc: maximum designed memory read count in bytes
3799  *    or appropriate error value.
3800  */
3801 int pcix_get_max_mmrbc(struct pci_dev *dev)
3802 {
3803 	int cap;
3804 	u32 stat;
3805 
3806 	cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
3807 	if (!cap)
3808 		return -EINVAL;
3809 
3810 	if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat))
3811 		return -EINVAL;
3812 
3813 	return 512 << ((stat & PCI_X_STATUS_MAX_READ) >> 21);
3814 }
3815 EXPORT_SYMBOL(pcix_get_max_mmrbc);
3816 
3817 /**
3818  * pcix_get_mmrbc - get PCI-X maximum memory read byte count
3819  * @dev: PCI device to query
3820  *
3821  * Returns mmrbc: maximum memory read count in bytes
3822  *    or appropriate error value.
3823  */
3824 int pcix_get_mmrbc(struct pci_dev *dev)
3825 {
3826 	int cap;
3827 	u16 cmd;
3828 
3829 	cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
3830 	if (!cap)
3831 		return -EINVAL;
3832 
3833 	if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd))
3834 		return -EINVAL;
3835 
3836 	return 512 << ((cmd & PCI_X_CMD_MAX_READ) >> 2);
3837 }
3838 EXPORT_SYMBOL(pcix_get_mmrbc);
3839 
3840 /**
3841  * pcix_set_mmrbc - set PCI-X maximum memory read byte count
3842  * @dev: PCI device to query
3843  * @mmrbc: maximum memory read count in bytes
3844  *    valid values are 512, 1024, 2048, 4096
3845  *
3846  * If possible sets maximum memory read byte count, some bridges have erratas
3847  * that prevent this.
3848  */
3849 int pcix_set_mmrbc(struct pci_dev *dev, int mmrbc)
3850 {
3851 	int cap;
3852 	u32 stat, v, o;
3853 	u16 cmd;
3854 
3855 	if (mmrbc < 512 || mmrbc > 4096 || !is_power_of_2(mmrbc))
3856 		return -EINVAL;
3857 
3858 	v = ffs(mmrbc) - 10;
3859 
3860 	cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
3861 	if (!cap)
3862 		return -EINVAL;
3863 
3864 	if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat))
3865 		return -EINVAL;
3866 
3867 	if (v > (stat & PCI_X_STATUS_MAX_READ) >> 21)
3868 		return -E2BIG;
3869 
3870 	if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd))
3871 		return -EINVAL;
3872 
3873 	o = (cmd & PCI_X_CMD_MAX_READ) >> 2;
3874 	if (o != v) {
3875 		if (v > o && (dev->bus->bus_flags & PCI_BUS_FLAGS_NO_MMRBC))
3876 			return -EIO;
3877 
3878 		cmd &= ~PCI_X_CMD_MAX_READ;
3879 		cmd |= v << 2;
3880 		if (pci_write_config_word(dev, cap + PCI_X_CMD, cmd))
3881 			return -EIO;
3882 	}
3883 	return 0;
3884 }
3885 EXPORT_SYMBOL(pcix_set_mmrbc);
3886 
3887 /**
3888  * pcie_get_readrq - get PCI Express read request size
3889  * @dev: PCI device to query
3890  *
3891  * Returns maximum memory read request in bytes
3892  *    or appropriate error value.
3893  */
3894 int pcie_get_readrq(struct pci_dev *dev)
3895 {
3896 	u16 ctl;
3897 
3898 	pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl);
3899 
3900 	return 128 << ((ctl & PCI_EXP_DEVCTL_READRQ) >> 12);
3901 }
3902 EXPORT_SYMBOL(pcie_get_readrq);
3903 
3904 /**
3905  * pcie_set_readrq - set PCI Express maximum memory read request
3906  * @dev: PCI device to query
3907  * @rq: maximum memory read count in bytes
3908  *    valid values are 128, 256, 512, 1024, 2048, 4096
3909  *
3910  * If possible sets maximum memory read request in bytes
3911  */
3912 int pcie_set_readrq(struct pci_dev *dev, int rq)
3913 {
3914 	u16 v;
3915 
3916 	if (rq < 128 || rq > 4096 || !is_power_of_2(rq))
3917 		return -EINVAL;
3918 
3919 	/*
3920 	 * If using the "performance" PCIe config, we clamp the
3921 	 * read rq size to the max packet size to prevent the
3922 	 * host bridge generating requests larger than we can
3923 	 * cope with
3924 	 */
3925 	if (pcie_bus_config == PCIE_BUS_PERFORMANCE) {
3926 		int mps = pcie_get_mps(dev);
3927 
3928 		if (mps < rq)
3929 			rq = mps;
3930 	}
3931 
3932 	v = (ffs(rq) - 8) << 12;
3933 
3934 	return pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
3935 						  PCI_EXP_DEVCTL_READRQ, v);
3936 }
3937 EXPORT_SYMBOL(pcie_set_readrq);
3938 
3939 /**
3940  * pcie_get_mps - get PCI Express maximum payload size
3941  * @dev: PCI device to query
3942  *
3943  * Returns maximum payload size in bytes
3944  */
3945 int pcie_get_mps(struct pci_dev *dev)
3946 {
3947 	u16 ctl;
3948 
3949 	pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl);
3950 
3951 	return 128 << ((ctl & PCI_EXP_DEVCTL_PAYLOAD) >> 5);
3952 }
3953 EXPORT_SYMBOL(pcie_get_mps);
3954 
3955 /**
3956  * pcie_set_mps - set PCI Express maximum payload size
3957  * @dev: PCI device to query
3958  * @mps: maximum payload size in bytes
3959  *    valid values are 128, 256, 512, 1024, 2048, 4096
3960  *
3961  * If possible sets maximum payload size
3962  */
3963 int pcie_set_mps(struct pci_dev *dev, int mps)
3964 {
3965 	u16 v;
3966 
3967 	if (mps < 128 || mps > 4096 || !is_power_of_2(mps))
3968 		return -EINVAL;
3969 
3970 	v = ffs(mps) - 8;
3971 	if (v > dev->pcie_mpss)
3972 		return -EINVAL;
3973 	v <<= 5;
3974 
3975 	return pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
3976 						  PCI_EXP_DEVCTL_PAYLOAD, v);
3977 }
3978 EXPORT_SYMBOL(pcie_set_mps);
3979 
3980 /**
3981  * pcie_get_minimum_link - determine minimum link settings of a PCI device
3982  * @dev: PCI device to query
3983  * @speed: storage for minimum speed
3984  * @width: storage for minimum width
3985  *
3986  * This function will walk up the PCI device chain and determine the minimum
3987  * link width and speed of the device.
3988  */
3989 int pcie_get_minimum_link(struct pci_dev *dev, enum pci_bus_speed *speed,
3990 			  enum pcie_link_width *width)
3991 {
3992 	int ret;
3993 
3994 	*speed = PCI_SPEED_UNKNOWN;
3995 	*width = PCIE_LNK_WIDTH_UNKNOWN;
3996 
3997 	while (dev) {
3998 		u16 lnksta;
3999 		enum pci_bus_speed next_speed;
4000 		enum pcie_link_width next_width;
4001 
4002 		ret = pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta);
4003 		if (ret)
4004 			return ret;
4005 
4006 		next_speed = pcie_link_speed[lnksta & PCI_EXP_LNKSTA_CLS];
4007 		next_width = (lnksta & PCI_EXP_LNKSTA_NLW) >>
4008 			PCI_EXP_LNKSTA_NLW_SHIFT;
4009 
4010 		if (next_speed < *speed)
4011 			*speed = next_speed;
4012 
4013 		if (next_width < *width)
4014 			*width = next_width;
4015 
4016 		dev = dev->bus->self;
4017 	}
4018 
4019 	return 0;
4020 }
4021 EXPORT_SYMBOL(pcie_get_minimum_link);
4022 
4023 /**
4024  * pci_select_bars - Make BAR mask from the type of resource
4025  * @dev: the PCI device for which BAR mask is made
4026  * @flags: resource type mask to be selected
4027  *
4028  * This helper routine makes bar mask from the type of resource.
4029  */
4030 int pci_select_bars(struct pci_dev *dev, unsigned long flags)
4031 {
4032 	int i, bars = 0;
4033 	for (i = 0; i < PCI_NUM_RESOURCES; i++)
4034 		if (pci_resource_flags(dev, i) & flags)
4035 			bars |= (1 << i);
4036 	return bars;
4037 }
4038 
4039 /**
4040  * pci_resource_bar - get position of the BAR associated with a resource
4041  * @dev: the PCI device
4042  * @resno: the resource number
4043  * @type: the BAR type to be filled in
4044  *
4045  * Returns BAR position in config space, or 0 if the BAR is invalid.
4046  */
4047 int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type)
4048 {
4049 	int reg;
4050 
4051 	if (resno < PCI_ROM_RESOURCE) {
4052 		*type = pci_bar_unknown;
4053 		return PCI_BASE_ADDRESS_0 + 4 * resno;
4054 	} else if (resno == PCI_ROM_RESOURCE) {
4055 		*type = pci_bar_mem32;
4056 		return dev->rom_base_reg;
4057 	} else if (resno < PCI_BRIDGE_RESOURCES) {
4058 		/* device specific resource */
4059 		reg = pci_iov_resource_bar(dev, resno, type);
4060 		if (reg)
4061 			return reg;
4062 	}
4063 
4064 	dev_err(&dev->dev, "BAR %d: invalid resource\n", resno);
4065 	return 0;
4066 }
4067 
4068 /* Some architectures require additional programming to enable VGA */
4069 static arch_set_vga_state_t arch_set_vga_state;
4070 
4071 void __init pci_register_set_vga_state(arch_set_vga_state_t func)
4072 {
4073 	arch_set_vga_state = func;	/* NULL disables */
4074 }
4075 
4076 static int pci_set_vga_state_arch(struct pci_dev *dev, bool decode,
4077 		      unsigned int command_bits, u32 flags)
4078 {
4079 	if (arch_set_vga_state)
4080 		return arch_set_vga_state(dev, decode, command_bits,
4081 						flags);
4082 	return 0;
4083 }
4084 
4085 /**
4086  * pci_set_vga_state - set VGA decode state on device and parents if requested
4087  * @dev: the PCI device
4088  * @decode: true = enable decoding, false = disable decoding
4089  * @command_bits: PCI_COMMAND_IO and/or PCI_COMMAND_MEMORY
4090  * @flags: traverse ancestors and change bridges
4091  * CHANGE_BRIDGE_ONLY / CHANGE_BRIDGE
4092  */
4093 int pci_set_vga_state(struct pci_dev *dev, bool decode,
4094 		      unsigned int command_bits, u32 flags)
4095 {
4096 	struct pci_bus *bus;
4097 	struct pci_dev *bridge;
4098 	u16 cmd;
4099 	int rc;
4100 
4101 	WARN_ON((flags & PCI_VGA_STATE_CHANGE_DECODES) & (command_bits & ~(PCI_COMMAND_IO|PCI_COMMAND_MEMORY)));
4102 
4103 	/* ARCH specific VGA enables */
4104 	rc = pci_set_vga_state_arch(dev, decode, command_bits, flags);
4105 	if (rc)
4106 		return rc;
4107 
4108 	if (flags & PCI_VGA_STATE_CHANGE_DECODES) {
4109 		pci_read_config_word(dev, PCI_COMMAND, &cmd);
4110 		if (decode == true)
4111 			cmd |= command_bits;
4112 		else
4113 			cmd &= ~command_bits;
4114 		pci_write_config_word(dev, PCI_COMMAND, cmd);
4115 	}
4116 
4117 	if (!(flags & PCI_VGA_STATE_CHANGE_BRIDGE))
4118 		return 0;
4119 
4120 	bus = dev->bus;
4121 	while (bus) {
4122 		bridge = bus->self;
4123 		if (bridge) {
4124 			pci_read_config_word(bridge, PCI_BRIDGE_CONTROL,
4125 					     &cmd);
4126 			if (decode == true)
4127 				cmd |= PCI_BRIDGE_CTL_VGA;
4128 			else
4129 				cmd &= ~PCI_BRIDGE_CTL_VGA;
4130 			pci_write_config_word(bridge, PCI_BRIDGE_CONTROL,
4131 					      cmd);
4132 		}
4133 		bus = bus->parent;
4134 	}
4135 	return 0;
4136 }
4137 
4138 bool pci_device_is_present(struct pci_dev *pdev)
4139 {
4140 	u32 v;
4141 
4142 	return pci_bus_read_dev_vendor_id(pdev->bus, pdev->devfn, &v, 0);
4143 }
4144 EXPORT_SYMBOL_GPL(pci_device_is_present);
4145 
4146 #define RESOURCE_ALIGNMENT_PARAM_SIZE COMMAND_LINE_SIZE
4147 static char resource_alignment_param[RESOURCE_ALIGNMENT_PARAM_SIZE] = {0};
4148 static DEFINE_SPINLOCK(resource_alignment_lock);
4149 
4150 /**
4151  * pci_specified_resource_alignment - get resource alignment specified by user.
4152  * @dev: the PCI device to get
4153  *
4154  * RETURNS: Resource alignment if it is specified.
4155  *          Zero if it is not specified.
4156  */
4157 static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev)
4158 {
4159 	int seg, bus, slot, func, align_order, count;
4160 	resource_size_t align = 0;
4161 	char *p;
4162 
4163 	spin_lock(&resource_alignment_lock);
4164 	p = resource_alignment_param;
4165 	while (*p) {
4166 		count = 0;
4167 		if (sscanf(p, "%d%n", &align_order, &count) == 1 &&
4168 							p[count] == '@') {
4169 			p += count + 1;
4170 		} else {
4171 			align_order = -1;
4172 		}
4173 		if (sscanf(p, "%x:%x:%x.%x%n",
4174 			&seg, &bus, &slot, &func, &count) != 4) {
4175 			seg = 0;
4176 			if (sscanf(p, "%x:%x.%x%n",
4177 					&bus, &slot, &func, &count) != 3) {
4178 				/* Invalid format */
4179 				printk(KERN_ERR "PCI: Can't parse resource_alignment parameter: %s\n",
4180 					p);
4181 				break;
4182 			}
4183 		}
4184 		p += count;
4185 		if (seg == pci_domain_nr(dev->bus) &&
4186 			bus == dev->bus->number &&
4187 			slot == PCI_SLOT(dev->devfn) &&
4188 			func == PCI_FUNC(dev->devfn)) {
4189 			if (align_order == -1) {
4190 				align = PAGE_SIZE;
4191 			} else {
4192 				align = 1 << align_order;
4193 			}
4194 			/* Found */
4195 			break;
4196 		}
4197 		if (*p != ';' && *p != ',') {
4198 			/* End of param or invalid format */
4199 			break;
4200 		}
4201 		p++;
4202 	}
4203 	spin_unlock(&resource_alignment_lock);
4204 	return align;
4205 }
4206 
4207 /*
4208  * This function disables memory decoding and releases memory resources
4209  * of the device specified by kernel's boot parameter 'pci=resource_alignment='.
4210  * It also rounds up size to specified alignment.
4211  * Later on, the kernel will assign page-aligned memory resource back
4212  * to the device.
4213  */
4214 void pci_reassigndev_resource_alignment(struct pci_dev *dev)
4215 {
4216 	int i;
4217 	struct resource *r;
4218 	resource_size_t align, size;
4219 	u16 command;
4220 
4221 	/* check if specified PCI is target device to reassign */
4222 	align = pci_specified_resource_alignment(dev);
4223 	if (!align)
4224 		return;
4225 
4226 	if (dev->hdr_type == PCI_HEADER_TYPE_NORMAL &&
4227 	    (dev->class >> 8) == PCI_CLASS_BRIDGE_HOST) {
4228 		dev_warn(&dev->dev,
4229 			"Can't reassign resources to host bridge.\n");
4230 		return;
4231 	}
4232 
4233 	dev_info(&dev->dev,
4234 		"Disabling memory decoding and releasing memory resources.\n");
4235 	pci_read_config_word(dev, PCI_COMMAND, &command);
4236 	command &= ~PCI_COMMAND_MEMORY;
4237 	pci_write_config_word(dev, PCI_COMMAND, command);
4238 
4239 	for (i = 0; i < PCI_BRIDGE_RESOURCES; i++) {
4240 		r = &dev->resource[i];
4241 		if (!(r->flags & IORESOURCE_MEM))
4242 			continue;
4243 		size = resource_size(r);
4244 		if (size < align) {
4245 			size = align;
4246 			dev_info(&dev->dev,
4247 				"Rounding up size of resource #%d to %#llx.\n",
4248 				i, (unsigned long long)size);
4249 		}
4250 		r->end = size - 1;
4251 		r->start = 0;
4252 	}
4253 	/* Need to disable bridge's resource window,
4254 	 * to enable the kernel to reassign new resource
4255 	 * window later on.
4256 	 */
4257 	if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE &&
4258 	    (dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
4259 		for (i = PCI_BRIDGE_RESOURCES; i < PCI_NUM_RESOURCES; i++) {
4260 			r = &dev->resource[i];
4261 			if (!(r->flags & IORESOURCE_MEM))
4262 				continue;
4263 			r->end = resource_size(r) - 1;
4264 			r->start = 0;
4265 		}
4266 		pci_disable_bridge_window(dev);
4267 	}
4268 }
4269 
4270 static ssize_t pci_set_resource_alignment_param(const char *buf, size_t count)
4271 {
4272 	if (count > RESOURCE_ALIGNMENT_PARAM_SIZE - 1)
4273 		count = RESOURCE_ALIGNMENT_PARAM_SIZE - 1;
4274 	spin_lock(&resource_alignment_lock);
4275 	strncpy(resource_alignment_param, buf, count);
4276 	resource_alignment_param[count] = '\0';
4277 	spin_unlock(&resource_alignment_lock);
4278 	return count;
4279 }
4280 
4281 static ssize_t pci_get_resource_alignment_param(char *buf, size_t size)
4282 {
4283 	size_t count;
4284 	spin_lock(&resource_alignment_lock);
4285 	count = snprintf(buf, size, "%s", resource_alignment_param);
4286 	spin_unlock(&resource_alignment_lock);
4287 	return count;
4288 }
4289 
4290 static ssize_t pci_resource_alignment_show(struct bus_type *bus, char *buf)
4291 {
4292 	return pci_get_resource_alignment_param(buf, PAGE_SIZE);
4293 }
4294 
4295 static ssize_t pci_resource_alignment_store(struct bus_type *bus,
4296 					const char *buf, size_t count)
4297 {
4298 	return pci_set_resource_alignment_param(buf, count);
4299 }
4300 
4301 BUS_ATTR(resource_alignment, 0644, pci_resource_alignment_show,
4302 					pci_resource_alignment_store);
4303 
4304 static int __init pci_resource_alignment_sysfs_init(void)
4305 {
4306 	return bus_create_file(&pci_bus_type,
4307 					&bus_attr_resource_alignment);
4308 }
4309 
4310 late_initcall(pci_resource_alignment_sysfs_init);
4311 
4312 static void pci_no_domains(void)
4313 {
4314 #ifdef CONFIG_PCI_DOMAINS
4315 	pci_domains_supported = 0;
4316 #endif
4317 }
4318 
4319 /**
4320  * pci_ext_cfg_avail - can we access extended PCI config space?
4321  *
4322  * Returns 1 if we can access PCI extended config space (offsets
4323  * greater than 0xff). This is the default implementation. Architecture
4324  * implementations can override this.
4325  */
4326 int __weak pci_ext_cfg_avail(void)
4327 {
4328 	return 1;
4329 }
4330 
4331 void __weak pci_fixup_cardbus(struct pci_bus *bus)
4332 {
4333 }
4334 EXPORT_SYMBOL(pci_fixup_cardbus);
4335 
4336 static int __init pci_setup(char *str)
4337 {
4338 	while (str) {
4339 		char *k = strchr(str, ',');
4340 		if (k)
4341 			*k++ = 0;
4342 		if (*str && (str = pcibios_setup(str)) && *str) {
4343 			if (!strcmp(str, "nomsi")) {
4344 				pci_no_msi();
4345 			} else if (!strcmp(str, "noaer")) {
4346 				pci_no_aer();
4347 			} else if (!strncmp(str, "realloc=", 8)) {
4348 				pci_realloc_get_opt(str + 8);
4349 			} else if (!strncmp(str, "realloc", 7)) {
4350 				pci_realloc_get_opt("on");
4351 			} else if (!strcmp(str, "nodomains")) {
4352 				pci_no_domains();
4353 			} else if (!strncmp(str, "noari", 5)) {
4354 				pcie_ari_disabled = true;
4355 			} else if (!strncmp(str, "cbiosize=", 9)) {
4356 				pci_cardbus_io_size = memparse(str + 9, &str);
4357 			} else if (!strncmp(str, "cbmemsize=", 10)) {
4358 				pci_cardbus_mem_size = memparse(str + 10, &str);
4359 			} else if (!strncmp(str, "resource_alignment=", 19)) {
4360 				pci_set_resource_alignment_param(str + 19,
4361 							strlen(str + 19));
4362 			} else if (!strncmp(str, "ecrc=", 5)) {
4363 				pcie_ecrc_get_policy(str + 5);
4364 			} else if (!strncmp(str, "hpiosize=", 9)) {
4365 				pci_hotplug_io_size = memparse(str + 9, &str);
4366 			} else if (!strncmp(str, "hpmemsize=", 10)) {
4367 				pci_hotplug_mem_size = memparse(str + 10, &str);
4368 			} else if (!strncmp(str, "pcie_bus_tune_off", 17)) {
4369 				pcie_bus_config = PCIE_BUS_TUNE_OFF;
4370 			} else if (!strncmp(str, "pcie_bus_safe", 13)) {
4371 				pcie_bus_config = PCIE_BUS_SAFE;
4372 			} else if (!strncmp(str, "pcie_bus_perf", 13)) {
4373 				pcie_bus_config = PCIE_BUS_PERFORMANCE;
4374 			} else if (!strncmp(str, "pcie_bus_peer2peer", 18)) {
4375 				pcie_bus_config = PCIE_BUS_PEER2PEER;
4376 			} else if (!strncmp(str, "pcie_scan_all", 13)) {
4377 				pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS);
4378 			} else {
4379 				printk(KERN_ERR "PCI: Unknown option `%s'\n",
4380 						str);
4381 			}
4382 		}
4383 		str = k;
4384 	}
4385 	return 0;
4386 }
4387 early_param("pci", pci_setup);
4388 
4389 EXPORT_SYMBOL(pci_reenable_device);
4390 EXPORT_SYMBOL(pci_enable_device_io);
4391 EXPORT_SYMBOL(pci_enable_device_mem);
4392 EXPORT_SYMBOL(pci_enable_device);
4393 EXPORT_SYMBOL(pcim_enable_device);
4394 EXPORT_SYMBOL(pcim_pin_device);
4395 EXPORT_SYMBOL(pci_disable_device);
4396 EXPORT_SYMBOL(pci_find_capability);
4397 EXPORT_SYMBOL(pci_bus_find_capability);
4398 EXPORT_SYMBOL(pci_release_regions);
4399 EXPORT_SYMBOL(pci_request_regions);
4400 EXPORT_SYMBOL(pci_request_regions_exclusive);
4401 EXPORT_SYMBOL(pci_release_region);
4402 EXPORT_SYMBOL(pci_request_region);
4403 EXPORT_SYMBOL(pci_request_region_exclusive);
4404 EXPORT_SYMBOL(pci_release_selected_regions);
4405 EXPORT_SYMBOL(pci_request_selected_regions);
4406 EXPORT_SYMBOL(pci_request_selected_regions_exclusive);
4407 EXPORT_SYMBOL(pci_set_master);
4408 EXPORT_SYMBOL(pci_clear_master);
4409 EXPORT_SYMBOL(pci_set_mwi);
4410 EXPORT_SYMBOL(pci_try_set_mwi);
4411 EXPORT_SYMBOL(pci_clear_mwi);
4412 EXPORT_SYMBOL_GPL(pci_intx);
4413 EXPORT_SYMBOL(pci_assign_resource);
4414 EXPORT_SYMBOL(pci_find_parent_resource);
4415 EXPORT_SYMBOL(pci_select_bars);
4416 
4417 EXPORT_SYMBOL(pci_set_power_state);
4418 EXPORT_SYMBOL(pci_save_state);
4419 EXPORT_SYMBOL(pci_restore_state);
4420 EXPORT_SYMBOL(pci_pme_capable);
4421 EXPORT_SYMBOL(pci_pme_active);
4422 EXPORT_SYMBOL(pci_wake_from_d3);
4423 EXPORT_SYMBOL(pci_prepare_to_sleep);
4424 EXPORT_SYMBOL(pci_back_from_sleep);
4425 EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state);
4426