xref: /linux/drivers/pci/pci.c (revision 95e9fd10f06cb5642028b6b851e32b8c8afb4571)
1 /*
2  *	PCI Bus Services, see include/linux/pci.h for further explanation.
3  *
4  *	Copyright 1993 -- 1997 Drew Eckhardt, Frederic Potter,
5  *	David Mosberger-Tang
6  *
7  *	Copyright 1997 -- 2000 Martin Mares <mj@ucw.cz>
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/delay.h>
12 #include <linux/init.h>
13 #include <linux/pci.h>
14 #include <linux/pm.h>
15 #include <linux/slab.h>
16 #include <linux/module.h>
17 #include <linux/spinlock.h>
18 #include <linux/string.h>
19 #include <linux/log2.h>
20 #include <linux/pci-aspm.h>
21 #include <linux/pm_wakeup.h>
22 #include <linux/interrupt.h>
23 #include <linux/device.h>
24 #include <linux/pm_runtime.h>
25 #include <asm-generic/pci-bridge.h>
26 #include <asm/setup.h>
27 #include "pci.h"
28 
29 const char *pci_power_names[] = {
30 	"error", "D0", "D1", "D2", "D3hot", "D3cold", "unknown",
31 };
32 EXPORT_SYMBOL_GPL(pci_power_names);
33 
34 int isa_dma_bridge_buggy;
35 EXPORT_SYMBOL(isa_dma_bridge_buggy);
36 
37 int pci_pci_problems;
38 EXPORT_SYMBOL(pci_pci_problems);
39 
40 unsigned int pci_pm_d3_delay;
41 
42 static void pci_pme_list_scan(struct work_struct *work);
43 
44 static LIST_HEAD(pci_pme_list);
45 static DEFINE_MUTEX(pci_pme_list_mutex);
46 static DECLARE_DELAYED_WORK(pci_pme_work, pci_pme_list_scan);
47 
48 struct pci_pme_device {
49 	struct list_head list;
50 	struct pci_dev *dev;
51 };
52 
53 #define PME_TIMEOUT 1000 /* How long between PME checks */
54 
55 static void pci_dev_d3_sleep(struct pci_dev *dev)
56 {
57 	unsigned int delay = dev->d3_delay;
58 
59 	if (delay < pci_pm_d3_delay)
60 		delay = pci_pm_d3_delay;
61 
62 	msleep(delay);
63 }
64 
65 #ifdef CONFIG_PCI_DOMAINS
66 int pci_domains_supported = 1;
67 #endif
68 
69 #define DEFAULT_CARDBUS_IO_SIZE		(256)
70 #define DEFAULT_CARDBUS_MEM_SIZE	(64*1024*1024)
71 /* pci=cbmemsize=nnM,cbiosize=nn can override this */
72 unsigned long pci_cardbus_io_size = DEFAULT_CARDBUS_IO_SIZE;
73 unsigned long pci_cardbus_mem_size = DEFAULT_CARDBUS_MEM_SIZE;
74 
75 #define DEFAULT_HOTPLUG_IO_SIZE		(256)
76 #define DEFAULT_HOTPLUG_MEM_SIZE	(2*1024*1024)
77 /* pci=hpmemsize=nnM,hpiosize=nn can override this */
78 unsigned long pci_hotplug_io_size  = DEFAULT_HOTPLUG_IO_SIZE;
79 unsigned long pci_hotplug_mem_size = DEFAULT_HOTPLUG_MEM_SIZE;
80 
81 enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_TUNE_OFF;
82 
83 /*
84  * The default CLS is used if arch didn't set CLS explicitly and not
85  * all pci devices agree on the same value.  Arch can override either
86  * the dfl or actual value as it sees fit.  Don't forget this is
87  * measured in 32-bit words, not bytes.
88  */
89 u8 pci_dfl_cache_line_size __devinitdata = L1_CACHE_BYTES >> 2;
90 u8 pci_cache_line_size;
91 
92 /*
93  * If we set up a device for bus mastering, we need to check the latency
94  * timer as certain BIOSes forget to set it properly.
95  */
96 unsigned int pcibios_max_latency = 255;
97 
98 /* If set, the PCIe ARI capability will not be used. */
99 static bool pcie_ari_disabled;
100 
101 /**
102  * pci_bus_max_busnr - returns maximum PCI bus number of given bus' children
103  * @bus: pointer to PCI bus structure to search
104  *
105  * Given a PCI bus, returns the highest PCI bus number present in the set
106  * including the given PCI bus and its list of child PCI buses.
107  */
108 unsigned char pci_bus_max_busnr(struct pci_bus* bus)
109 {
110 	struct list_head *tmp;
111 	unsigned char max, n;
112 
113 	max = bus->busn_res.end;
114 	list_for_each(tmp, &bus->children) {
115 		n = pci_bus_max_busnr(pci_bus_b(tmp));
116 		if(n > max)
117 			max = n;
118 	}
119 	return max;
120 }
121 EXPORT_SYMBOL_GPL(pci_bus_max_busnr);
122 
123 #ifdef CONFIG_HAS_IOMEM
124 void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar)
125 {
126 	/*
127 	 * Make sure the BAR is actually a memory resource, not an IO resource
128 	 */
129 	if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM)) {
130 		WARN_ON(1);
131 		return NULL;
132 	}
133 	return ioremap_nocache(pci_resource_start(pdev, bar),
134 				     pci_resource_len(pdev, bar));
135 }
136 EXPORT_SYMBOL_GPL(pci_ioremap_bar);
137 #endif
138 
139 #define PCI_FIND_CAP_TTL	48
140 
141 static int __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn,
142 				   u8 pos, int cap, int *ttl)
143 {
144 	u8 id;
145 
146 	while ((*ttl)--) {
147 		pci_bus_read_config_byte(bus, devfn, pos, &pos);
148 		if (pos < 0x40)
149 			break;
150 		pos &= ~3;
151 		pci_bus_read_config_byte(bus, devfn, pos + PCI_CAP_LIST_ID,
152 					 &id);
153 		if (id == 0xff)
154 			break;
155 		if (id == cap)
156 			return pos;
157 		pos += PCI_CAP_LIST_NEXT;
158 	}
159 	return 0;
160 }
161 
162 static int __pci_find_next_cap(struct pci_bus *bus, unsigned int devfn,
163 			       u8 pos, int cap)
164 {
165 	int ttl = PCI_FIND_CAP_TTL;
166 
167 	return __pci_find_next_cap_ttl(bus, devfn, pos, cap, &ttl);
168 }
169 
170 int pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap)
171 {
172 	return __pci_find_next_cap(dev->bus, dev->devfn,
173 				   pos + PCI_CAP_LIST_NEXT, cap);
174 }
175 EXPORT_SYMBOL_GPL(pci_find_next_capability);
176 
177 static int __pci_bus_find_cap_start(struct pci_bus *bus,
178 				    unsigned int devfn, u8 hdr_type)
179 {
180 	u16 status;
181 
182 	pci_bus_read_config_word(bus, devfn, PCI_STATUS, &status);
183 	if (!(status & PCI_STATUS_CAP_LIST))
184 		return 0;
185 
186 	switch (hdr_type) {
187 	case PCI_HEADER_TYPE_NORMAL:
188 	case PCI_HEADER_TYPE_BRIDGE:
189 		return PCI_CAPABILITY_LIST;
190 	case PCI_HEADER_TYPE_CARDBUS:
191 		return PCI_CB_CAPABILITY_LIST;
192 	default:
193 		return 0;
194 	}
195 
196 	return 0;
197 }
198 
199 /**
200  * pci_find_capability - query for devices' capabilities
201  * @dev: PCI device to query
202  * @cap: capability code
203  *
204  * Tell if a device supports a given PCI capability.
205  * Returns the address of the requested capability structure within the
206  * device's PCI configuration space or 0 in case the device does not
207  * support it.  Possible values for @cap:
208  *
209  *  %PCI_CAP_ID_PM           Power Management
210  *  %PCI_CAP_ID_AGP          Accelerated Graphics Port
211  *  %PCI_CAP_ID_VPD          Vital Product Data
212  *  %PCI_CAP_ID_SLOTID       Slot Identification
213  *  %PCI_CAP_ID_MSI          Message Signalled Interrupts
214  *  %PCI_CAP_ID_CHSWP        CompactPCI HotSwap
215  *  %PCI_CAP_ID_PCIX         PCI-X
216  *  %PCI_CAP_ID_EXP          PCI Express
217  */
218 int pci_find_capability(struct pci_dev *dev, int cap)
219 {
220 	int pos;
221 
222 	pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);
223 	if (pos)
224 		pos = __pci_find_next_cap(dev->bus, dev->devfn, pos, cap);
225 
226 	return pos;
227 }
228 
229 /**
230  * pci_bus_find_capability - query for devices' capabilities
231  * @bus:   the PCI bus to query
232  * @devfn: PCI device to query
233  * @cap:   capability code
234  *
235  * Like pci_find_capability() but works for pci devices that do not have a
236  * pci_dev structure set up yet.
237  *
238  * Returns the address of the requested capability structure within the
239  * device's PCI configuration space or 0 in case the device does not
240  * support it.
241  */
242 int pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap)
243 {
244 	int pos;
245 	u8 hdr_type;
246 
247 	pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &hdr_type);
248 
249 	pos = __pci_bus_find_cap_start(bus, devfn, hdr_type & 0x7f);
250 	if (pos)
251 		pos = __pci_find_next_cap(bus, devfn, pos, cap);
252 
253 	return pos;
254 }
255 
256 /**
257  * pci_pcie_cap2 - query for devices' PCI_CAP_ID_EXP v2 capability structure
258  * @dev: PCI device to check
259  *
260  * Like pci_pcie_cap() but also checks that the PCIe capability version is
261  * >= 2.  Note that v1 capability structures could be sparse in that not
262  * all register fields were required.  v2 requires the entire structure to
263  * be present size wise, while still allowing for non-implemented registers
264  * to exist but they must be hardwired to 0.
265  *
266  * Due to the differences in the versions of capability structures, one
267  * must be careful not to try and access non-existant registers that may
268  * exist in early versions - v1 - of Express devices.
269  *
270  * Returns the offset of the PCIe capability structure as long as the
271  * capability version is >= 2; otherwise 0 is returned.
272  */
273 static int pci_pcie_cap2(struct pci_dev *dev)
274 {
275 	u16 flags;
276 	int pos;
277 
278 	pos = pci_pcie_cap(dev);
279 	if (pos) {
280 		pci_read_config_word(dev, pos + PCI_EXP_FLAGS, &flags);
281 		if ((flags & PCI_EXP_FLAGS_VERS) < 2)
282 			pos = 0;
283 	}
284 
285 	return pos;
286 }
287 
288 /**
289  * pci_find_ext_capability - Find an extended capability
290  * @dev: PCI device to query
291  * @cap: capability code
292  *
293  * Returns the address of the requested extended capability structure
294  * within the device's PCI configuration space or 0 if the device does
295  * not support it.  Possible values for @cap:
296  *
297  *  %PCI_EXT_CAP_ID_ERR		Advanced Error Reporting
298  *  %PCI_EXT_CAP_ID_VC		Virtual Channel
299  *  %PCI_EXT_CAP_ID_DSN		Device Serial Number
300  *  %PCI_EXT_CAP_ID_PWR		Power Budgeting
301  */
302 int pci_find_ext_capability(struct pci_dev *dev, int cap)
303 {
304 	u32 header;
305 	int ttl;
306 	int pos = PCI_CFG_SPACE_SIZE;
307 
308 	/* minimum 8 bytes per capability */
309 	ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8;
310 
311 	if (dev->cfg_size <= PCI_CFG_SPACE_SIZE)
312 		return 0;
313 
314 	if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
315 		return 0;
316 
317 	/*
318 	 * If we have no capabilities, this is indicated by cap ID,
319 	 * cap version and next pointer all being 0.
320 	 */
321 	if (header == 0)
322 		return 0;
323 
324 	while (ttl-- > 0) {
325 		if (PCI_EXT_CAP_ID(header) == cap)
326 			return pos;
327 
328 		pos = PCI_EXT_CAP_NEXT(header);
329 		if (pos < PCI_CFG_SPACE_SIZE)
330 			break;
331 
332 		if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
333 			break;
334 	}
335 
336 	return 0;
337 }
338 EXPORT_SYMBOL_GPL(pci_find_ext_capability);
339 
340 static int __pci_find_next_ht_cap(struct pci_dev *dev, int pos, int ht_cap)
341 {
342 	int rc, ttl = PCI_FIND_CAP_TTL;
343 	u8 cap, mask;
344 
345 	if (ht_cap == HT_CAPTYPE_SLAVE || ht_cap == HT_CAPTYPE_HOST)
346 		mask = HT_3BIT_CAP_MASK;
347 	else
348 		mask = HT_5BIT_CAP_MASK;
349 
350 	pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn, pos,
351 				      PCI_CAP_ID_HT, &ttl);
352 	while (pos) {
353 		rc = pci_read_config_byte(dev, pos + 3, &cap);
354 		if (rc != PCIBIOS_SUCCESSFUL)
355 			return 0;
356 
357 		if ((cap & mask) == ht_cap)
358 			return pos;
359 
360 		pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn,
361 					      pos + PCI_CAP_LIST_NEXT,
362 					      PCI_CAP_ID_HT, &ttl);
363 	}
364 
365 	return 0;
366 }
367 /**
368  * pci_find_next_ht_capability - query a device's Hypertransport capabilities
369  * @dev: PCI device to query
370  * @pos: Position from which to continue searching
371  * @ht_cap: Hypertransport capability code
372  *
373  * To be used in conjunction with pci_find_ht_capability() to search for
374  * all capabilities matching @ht_cap. @pos should always be a value returned
375  * from pci_find_ht_capability().
376  *
377  * NB. To be 100% safe against broken PCI devices, the caller should take
378  * steps to avoid an infinite loop.
379  */
380 int pci_find_next_ht_capability(struct pci_dev *dev, int pos, int ht_cap)
381 {
382 	return __pci_find_next_ht_cap(dev, pos + PCI_CAP_LIST_NEXT, ht_cap);
383 }
384 EXPORT_SYMBOL_GPL(pci_find_next_ht_capability);
385 
386 /**
387  * pci_find_ht_capability - query a device's Hypertransport capabilities
388  * @dev: PCI device to query
389  * @ht_cap: Hypertransport capability code
390  *
391  * Tell if a device supports a given Hypertransport capability.
392  * Returns an address within the device's PCI configuration space
393  * or 0 in case the device does not support the request capability.
394  * The address points to the PCI capability, of type PCI_CAP_ID_HT,
395  * which has a Hypertransport capability matching @ht_cap.
396  */
397 int pci_find_ht_capability(struct pci_dev *dev, int ht_cap)
398 {
399 	int pos;
400 
401 	pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);
402 	if (pos)
403 		pos = __pci_find_next_ht_cap(dev, pos, ht_cap);
404 
405 	return pos;
406 }
407 EXPORT_SYMBOL_GPL(pci_find_ht_capability);
408 
409 /**
410  * pci_find_parent_resource - return resource region of parent bus of given region
411  * @dev: PCI device structure contains resources to be searched
412  * @res: child resource record for which parent is sought
413  *
414  *  For given resource region of given device, return the resource
415  *  region of parent bus the given region is contained in or where
416  *  it should be allocated from.
417  */
418 struct resource *
419 pci_find_parent_resource(const struct pci_dev *dev, struct resource *res)
420 {
421 	const struct pci_bus *bus = dev->bus;
422 	int i;
423 	struct resource *best = NULL, *r;
424 
425 	pci_bus_for_each_resource(bus, r, i) {
426 		if (!r)
427 			continue;
428 		if (res->start && !(res->start >= r->start && res->end <= r->end))
429 			continue;	/* Not contained */
430 		if ((res->flags ^ r->flags) & (IORESOURCE_IO | IORESOURCE_MEM))
431 			continue;	/* Wrong type */
432 		if (!((res->flags ^ r->flags) & IORESOURCE_PREFETCH))
433 			return r;	/* Exact match */
434 		/* We can't insert a non-prefetch resource inside a prefetchable parent .. */
435 		if (r->flags & IORESOURCE_PREFETCH)
436 			continue;
437 		/* .. but we can put a prefetchable resource inside a non-prefetchable one */
438 		if (!best)
439 			best = r;
440 	}
441 	return best;
442 }
443 
444 /**
445  * pci_restore_bars - restore a devices BAR values (e.g. after wake-up)
446  * @dev: PCI device to have its BARs restored
447  *
448  * Restore the BAR values for a given device, so as to make it
449  * accessible by its driver.
450  */
451 static void
452 pci_restore_bars(struct pci_dev *dev)
453 {
454 	int i;
455 
456 	for (i = 0; i < PCI_BRIDGE_RESOURCES; i++)
457 		pci_update_resource(dev, i);
458 }
459 
460 static struct pci_platform_pm_ops *pci_platform_pm;
461 
462 int pci_set_platform_pm(struct pci_platform_pm_ops *ops)
463 {
464 	if (!ops->is_manageable || !ops->set_state || !ops->choose_state
465 	    || !ops->sleep_wake || !ops->can_wakeup)
466 		return -EINVAL;
467 	pci_platform_pm = ops;
468 	return 0;
469 }
470 
471 static inline bool platform_pci_power_manageable(struct pci_dev *dev)
472 {
473 	return pci_platform_pm ? pci_platform_pm->is_manageable(dev) : false;
474 }
475 
476 static inline int platform_pci_set_power_state(struct pci_dev *dev,
477                                                 pci_power_t t)
478 {
479 	return pci_platform_pm ? pci_platform_pm->set_state(dev, t) : -ENOSYS;
480 }
481 
482 static inline pci_power_t platform_pci_choose_state(struct pci_dev *dev)
483 {
484 	return pci_platform_pm ?
485 			pci_platform_pm->choose_state(dev) : PCI_POWER_ERROR;
486 }
487 
488 static inline bool platform_pci_can_wakeup(struct pci_dev *dev)
489 {
490 	return pci_platform_pm ? pci_platform_pm->can_wakeup(dev) : false;
491 }
492 
493 static inline int platform_pci_sleep_wake(struct pci_dev *dev, bool enable)
494 {
495 	return pci_platform_pm ?
496 			pci_platform_pm->sleep_wake(dev, enable) : -ENODEV;
497 }
498 
499 static inline int platform_pci_run_wake(struct pci_dev *dev, bool enable)
500 {
501 	return pci_platform_pm ?
502 			pci_platform_pm->run_wake(dev, enable) : -ENODEV;
503 }
504 
505 /**
506  * pci_raw_set_power_state - Use PCI PM registers to set the power state of
507  *                           given PCI device
508  * @dev: PCI device to handle.
509  * @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
510  *
511  * RETURN VALUE:
512  * -EINVAL if the requested state is invalid.
513  * -EIO if device does not support PCI PM or its PM capabilities register has a
514  * wrong version, or device doesn't support the requested state.
515  * 0 if device already is in the requested state.
516  * 0 if device's power state has been successfully changed.
517  */
518 static int pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
519 {
520 	u16 pmcsr;
521 	bool need_restore = false;
522 
523 	/* Check if we're already there */
524 	if (dev->current_state == state)
525 		return 0;
526 
527 	if (!dev->pm_cap)
528 		return -EIO;
529 
530 	if (state < PCI_D0 || state > PCI_D3hot)
531 		return -EINVAL;
532 
533 	/* Validate current state:
534 	 * Can enter D0 from any state, but if we can only go deeper
535 	 * to sleep if we're already in a low power state
536 	 */
537 	if (state != PCI_D0 && dev->current_state <= PCI_D3cold
538 	    && dev->current_state > state) {
539 		dev_err(&dev->dev, "invalid power transition "
540 			"(from state %d to %d)\n", dev->current_state, state);
541 		return -EINVAL;
542 	}
543 
544 	/* check if this device supports the desired state */
545 	if ((state == PCI_D1 && !dev->d1_support)
546 	   || (state == PCI_D2 && !dev->d2_support))
547 		return -EIO;
548 
549 	pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
550 
551 	/* If we're (effectively) in D3, force entire word to 0.
552 	 * This doesn't affect PME_Status, disables PME_En, and
553 	 * sets PowerState to 0.
554 	 */
555 	switch (dev->current_state) {
556 	case PCI_D0:
557 	case PCI_D1:
558 	case PCI_D2:
559 		pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
560 		pmcsr |= state;
561 		break;
562 	case PCI_D3hot:
563 	case PCI_D3cold:
564 	case PCI_UNKNOWN: /* Boot-up */
565 		if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot
566 		 && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))
567 			need_restore = true;
568 		/* Fall-through: force to D0 */
569 	default:
570 		pmcsr = 0;
571 		break;
572 	}
573 
574 	/* enter specified state */
575 	pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
576 
577 	/* Mandatory power management transition delays */
578 	/* see PCI PM 1.1 5.6.1 table 18 */
579 	if (state == PCI_D3hot || dev->current_state == PCI_D3hot)
580 		pci_dev_d3_sleep(dev);
581 	else if (state == PCI_D2 || dev->current_state == PCI_D2)
582 		udelay(PCI_PM_D2_DELAY);
583 
584 	pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
585 	dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
586 	if (dev->current_state != state && printk_ratelimit())
587 		dev_info(&dev->dev, "Refused to change power state, "
588 			"currently in D%d\n", dev->current_state);
589 
590 	/*
591 	 * According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT
592 	 * INTERFACE SPECIFICATION, REV. 1.2", a device transitioning
593 	 * from D3hot to D0 _may_ perform an internal reset, thereby
594 	 * going to "D0 Uninitialized" rather than "D0 Initialized".
595 	 * For example, at least some versions of the 3c905B and the
596 	 * 3c556B exhibit this behaviour.
597 	 *
598 	 * At least some laptop BIOSen (e.g. the Thinkpad T21) leave
599 	 * devices in a D3hot state at boot.  Consequently, we need to
600 	 * restore at least the BARs so that the device will be
601 	 * accessible to its driver.
602 	 */
603 	if (need_restore)
604 		pci_restore_bars(dev);
605 
606 	if (dev->bus->self)
607 		pcie_aspm_pm_state_change(dev->bus->self);
608 
609 	return 0;
610 }
611 
612 /**
613  * pci_update_current_state - Read PCI power state of given device from its
614  *                            PCI PM registers and cache it
615  * @dev: PCI device to handle.
616  * @state: State to cache in case the device doesn't have the PM capability
617  */
618 void pci_update_current_state(struct pci_dev *dev, pci_power_t state)
619 {
620 	if (dev->pm_cap) {
621 		u16 pmcsr;
622 
623 		/*
624 		 * Configuration space is not accessible for device in
625 		 * D3cold, so just keep or set D3cold for safety
626 		 */
627 		if (dev->current_state == PCI_D3cold)
628 			return;
629 		if (state == PCI_D3cold) {
630 			dev->current_state = PCI_D3cold;
631 			return;
632 		}
633 		pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
634 		dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
635 	} else {
636 		dev->current_state = state;
637 	}
638 }
639 
640 /**
641  * pci_power_up - Put the given device into D0 forcibly
642  * @dev: PCI device to power up
643  */
644 void pci_power_up(struct pci_dev *dev)
645 {
646 	if (platform_pci_power_manageable(dev))
647 		platform_pci_set_power_state(dev, PCI_D0);
648 
649 	pci_raw_set_power_state(dev, PCI_D0);
650 	pci_update_current_state(dev, PCI_D0);
651 }
652 
653 /**
654  * pci_platform_power_transition - Use platform to change device power state
655  * @dev: PCI device to handle.
656  * @state: State to put the device into.
657  */
658 static int pci_platform_power_transition(struct pci_dev *dev, pci_power_t state)
659 {
660 	int error;
661 
662 	if (platform_pci_power_manageable(dev)) {
663 		error = platform_pci_set_power_state(dev, state);
664 		if (!error)
665 			pci_update_current_state(dev, state);
666 		/* Fall back to PCI_D0 if native PM is not supported */
667 		if (!dev->pm_cap)
668 			dev->current_state = PCI_D0;
669 	} else {
670 		error = -ENODEV;
671 		/* Fall back to PCI_D0 if native PM is not supported */
672 		if (!dev->pm_cap)
673 			dev->current_state = PCI_D0;
674 	}
675 
676 	return error;
677 }
678 
679 /**
680  * __pci_start_power_transition - Start power transition of a PCI device
681  * @dev: PCI device to handle.
682  * @state: State to put the device into.
683  */
684 static void __pci_start_power_transition(struct pci_dev *dev, pci_power_t state)
685 {
686 	if (state == PCI_D0) {
687 		pci_platform_power_transition(dev, PCI_D0);
688 		/*
689 		 * Mandatory power management transition delays, see
690 		 * PCI Express Base Specification Revision 2.0 Section
691 		 * 6.6.1: Conventional Reset.  Do not delay for
692 		 * devices powered on/off by corresponding bridge,
693 		 * because have already delayed for the bridge.
694 		 */
695 		if (dev->runtime_d3cold) {
696 			msleep(dev->d3cold_delay);
697 			/*
698 			 * When powering on a bridge from D3cold, the
699 			 * whole hierarchy may be powered on into
700 			 * D0uninitialized state, resume them to give
701 			 * them a chance to suspend again
702 			 */
703 			pci_wakeup_bus(dev->subordinate);
704 		}
705 	}
706 }
707 
708 /**
709  * __pci_dev_set_current_state - Set current state of a PCI device
710  * @dev: Device to handle
711  * @data: pointer to state to be set
712  */
713 static int __pci_dev_set_current_state(struct pci_dev *dev, void *data)
714 {
715 	pci_power_t state = *(pci_power_t *)data;
716 
717 	dev->current_state = state;
718 	return 0;
719 }
720 
721 /**
722  * __pci_bus_set_current_state - Walk given bus and set current state of devices
723  * @bus: Top bus of the subtree to walk.
724  * @state: state to be set
725  */
726 static void __pci_bus_set_current_state(struct pci_bus *bus, pci_power_t state)
727 {
728 	if (bus)
729 		pci_walk_bus(bus, __pci_dev_set_current_state, &state);
730 }
731 
732 /**
733  * __pci_complete_power_transition - Complete power transition of a PCI device
734  * @dev: PCI device to handle.
735  * @state: State to put the device into.
736  *
737  * This function should not be called directly by device drivers.
738  */
739 int __pci_complete_power_transition(struct pci_dev *dev, pci_power_t state)
740 {
741 	int ret;
742 
743 	if (state <= PCI_D0)
744 		return -EINVAL;
745 	ret = pci_platform_power_transition(dev, state);
746 	/* Power off the bridge may power off the whole hierarchy */
747 	if (!ret && state == PCI_D3cold)
748 		__pci_bus_set_current_state(dev->subordinate, PCI_D3cold);
749 	return ret;
750 }
751 EXPORT_SYMBOL_GPL(__pci_complete_power_transition);
752 
753 /**
754  * pci_set_power_state - Set the power state of a PCI device
755  * @dev: PCI device to handle.
756  * @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
757  *
758  * Transition a device to a new power state, using the platform firmware and/or
759  * the device's PCI PM registers.
760  *
761  * RETURN VALUE:
762  * -EINVAL if the requested state is invalid.
763  * -EIO if device does not support PCI PM or its PM capabilities register has a
764  * wrong version, or device doesn't support the requested state.
765  * 0 if device already is in the requested state.
766  * 0 if device's power state has been successfully changed.
767  */
768 int pci_set_power_state(struct pci_dev *dev, pci_power_t state)
769 {
770 	int error;
771 
772 	/* bound the state we're entering */
773 	if (state > PCI_D3cold)
774 		state = PCI_D3cold;
775 	else if (state < PCI_D0)
776 		state = PCI_D0;
777 	else if ((state == PCI_D1 || state == PCI_D2) && pci_no_d1d2(dev))
778 		/*
779 		 * If the device or the parent bridge do not support PCI PM,
780 		 * ignore the request if we're doing anything other than putting
781 		 * it into D0 (which would only happen on boot).
782 		 */
783 		return 0;
784 
785 	/* Check if we're already there */
786 	if (dev->current_state == state)
787 		return 0;
788 
789 	__pci_start_power_transition(dev, state);
790 
791 	/* This device is quirked not to be put into D3, so
792 	   don't put it in D3 */
793 	if (state >= PCI_D3hot && (dev->dev_flags & PCI_DEV_FLAGS_NO_D3))
794 		return 0;
795 
796 	/*
797 	 * To put device in D3cold, we put device into D3hot in native
798 	 * way, then put device into D3cold with platform ops
799 	 */
800 	error = pci_raw_set_power_state(dev, state > PCI_D3hot ?
801 					PCI_D3hot : state);
802 
803 	if (!__pci_complete_power_transition(dev, state))
804 		error = 0;
805 	/*
806 	 * When aspm_policy is "powersave" this call ensures
807 	 * that ASPM is configured.
808 	 */
809 	if (!error && dev->bus->self)
810 		pcie_aspm_powersave_config_link(dev->bus->self);
811 
812 	return error;
813 }
814 
815 /**
816  * pci_choose_state - Choose the power state of a PCI device
817  * @dev: PCI device to be suspended
818  * @state: target sleep state for the whole system. This is the value
819  *	that is passed to suspend() function.
820  *
821  * Returns PCI power state suitable for given device and given system
822  * message.
823  */
824 
825 pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state)
826 {
827 	pci_power_t ret;
828 
829 	if (!pci_find_capability(dev, PCI_CAP_ID_PM))
830 		return PCI_D0;
831 
832 	ret = platform_pci_choose_state(dev);
833 	if (ret != PCI_POWER_ERROR)
834 		return ret;
835 
836 	switch (state.event) {
837 	case PM_EVENT_ON:
838 		return PCI_D0;
839 	case PM_EVENT_FREEZE:
840 	case PM_EVENT_PRETHAW:
841 		/* REVISIT both freeze and pre-thaw "should" use D0 */
842 	case PM_EVENT_SUSPEND:
843 	case PM_EVENT_HIBERNATE:
844 		return PCI_D3hot;
845 	default:
846 		dev_info(&dev->dev, "unrecognized suspend event %d\n",
847 			 state.event);
848 		BUG();
849 	}
850 	return PCI_D0;
851 }
852 
853 EXPORT_SYMBOL(pci_choose_state);
854 
855 #define PCI_EXP_SAVE_REGS	7
856 
857 #define pcie_cap_has_devctl(type, flags)	1
858 #define pcie_cap_has_lnkctl(type, flags)		\
859 		((flags & PCI_EXP_FLAGS_VERS) > 1 ||	\
860 		 (type == PCI_EXP_TYPE_ROOT_PORT ||	\
861 		  type == PCI_EXP_TYPE_ENDPOINT ||	\
862 		  type == PCI_EXP_TYPE_LEG_END))
863 #define pcie_cap_has_sltctl(type, flags)		\
864 		((flags & PCI_EXP_FLAGS_VERS) > 1 ||	\
865 		 ((type == PCI_EXP_TYPE_ROOT_PORT) ||	\
866 		  (type == PCI_EXP_TYPE_DOWNSTREAM &&	\
867 		   (flags & PCI_EXP_FLAGS_SLOT))))
868 #define pcie_cap_has_rtctl(type, flags)			\
869 		((flags & PCI_EXP_FLAGS_VERS) > 1 ||	\
870 		 (type == PCI_EXP_TYPE_ROOT_PORT ||	\
871 		  type == PCI_EXP_TYPE_RC_EC))
872 
873 static struct pci_cap_saved_state *pci_find_saved_cap(
874 	struct pci_dev *pci_dev, char cap)
875 {
876 	struct pci_cap_saved_state *tmp;
877 	struct hlist_node *pos;
878 
879 	hlist_for_each_entry(tmp, pos, &pci_dev->saved_cap_space, next) {
880 		if (tmp->cap.cap_nr == cap)
881 			return tmp;
882 	}
883 	return NULL;
884 }
885 
886 static int pci_save_pcie_state(struct pci_dev *dev)
887 {
888 	int pos, i = 0;
889 	struct pci_cap_saved_state *save_state;
890 	u16 *cap;
891 	u16 flags;
892 
893 	pos = pci_pcie_cap(dev);
894 	if (!pos)
895 		return 0;
896 
897 	save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
898 	if (!save_state) {
899 		dev_err(&dev->dev, "buffer not found in %s\n", __func__);
900 		return -ENOMEM;
901 	}
902 	cap = (u16 *)&save_state->cap.data[0];
903 
904 	pci_read_config_word(dev, pos + PCI_EXP_FLAGS, &flags);
905 
906 	if (pcie_cap_has_devctl(dev->pcie_type, flags))
907 		pci_read_config_word(dev, pos + PCI_EXP_DEVCTL, &cap[i++]);
908 	if (pcie_cap_has_lnkctl(dev->pcie_type, flags))
909 		pci_read_config_word(dev, pos + PCI_EXP_LNKCTL, &cap[i++]);
910 	if (pcie_cap_has_sltctl(dev->pcie_type, flags))
911 		pci_read_config_word(dev, pos + PCI_EXP_SLTCTL, &cap[i++]);
912 	if (pcie_cap_has_rtctl(dev->pcie_type, flags))
913 		pci_read_config_word(dev, pos + PCI_EXP_RTCTL, &cap[i++]);
914 
915 	pos = pci_pcie_cap2(dev);
916 	if (!pos)
917 		return 0;
918 
919 	pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &cap[i++]);
920 	pci_read_config_word(dev, pos + PCI_EXP_LNKCTL2, &cap[i++]);
921 	pci_read_config_word(dev, pos + PCI_EXP_SLTCTL2, &cap[i++]);
922 	return 0;
923 }
924 
925 static void pci_restore_pcie_state(struct pci_dev *dev)
926 {
927 	int i = 0, pos;
928 	struct pci_cap_saved_state *save_state;
929 	u16 *cap;
930 	u16 flags;
931 
932 	save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
933 	pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
934 	if (!save_state || pos <= 0)
935 		return;
936 	cap = (u16 *)&save_state->cap.data[0];
937 
938 	pci_read_config_word(dev, pos + PCI_EXP_FLAGS, &flags);
939 
940 	if (pcie_cap_has_devctl(dev->pcie_type, flags))
941 		pci_write_config_word(dev, pos + PCI_EXP_DEVCTL, cap[i++]);
942 	if (pcie_cap_has_lnkctl(dev->pcie_type, flags))
943 		pci_write_config_word(dev, pos + PCI_EXP_LNKCTL, cap[i++]);
944 	if (pcie_cap_has_sltctl(dev->pcie_type, flags))
945 		pci_write_config_word(dev, pos + PCI_EXP_SLTCTL, cap[i++]);
946 	if (pcie_cap_has_rtctl(dev->pcie_type, flags))
947 		pci_write_config_word(dev, pos + PCI_EXP_RTCTL, cap[i++]);
948 
949 	pos = pci_pcie_cap2(dev);
950 	if (!pos)
951 		return;
952 
953 	pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, cap[i++]);
954 	pci_write_config_word(dev, pos + PCI_EXP_LNKCTL2, cap[i++]);
955 	pci_write_config_word(dev, pos + PCI_EXP_SLTCTL2, cap[i++]);
956 }
957 
958 
959 static int pci_save_pcix_state(struct pci_dev *dev)
960 {
961 	int pos;
962 	struct pci_cap_saved_state *save_state;
963 
964 	pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
965 	if (pos <= 0)
966 		return 0;
967 
968 	save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX);
969 	if (!save_state) {
970 		dev_err(&dev->dev, "buffer not found in %s\n", __func__);
971 		return -ENOMEM;
972 	}
973 
974 	pci_read_config_word(dev, pos + PCI_X_CMD,
975 			     (u16 *)save_state->cap.data);
976 
977 	return 0;
978 }
979 
980 static void pci_restore_pcix_state(struct pci_dev *dev)
981 {
982 	int i = 0, pos;
983 	struct pci_cap_saved_state *save_state;
984 	u16 *cap;
985 
986 	save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX);
987 	pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
988 	if (!save_state || pos <= 0)
989 		return;
990 	cap = (u16 *)&save_state->cap.data[0];
991 
992 	pci_write_config_word(dev, pos + PCI_X_CMD, cap[i++]);
993 }
994 
995 
996 /**
997  * pci_save_state - save the PCI configuration space of a device before suspending
998  * @dev: - PCI device that we're dealing with
999  */
1000 int
1001 pci_save_state(struct pci_dev *dev)
1002 {
1003 	int i;
1004 	/* XXX: 100% dword access ok here? */
1005 	for (i = 0; i < 16; i++)
1006 		pci_read_config_dword(dev, i * 4, &dev->saved_config_space[i]);
1007 	dev->state_saved = true;
1008 	if ((i = pci_save_pcie_state(dev)) != 0)
1009 		return i;
1010 	if ((i = pci_save_pcix_state(dev)) != 0)
1011 		return i;
1012 	return 0;
1013 }
1014 
1015 static void pci_restore_config_dword(struct pci_dev *pdev, int offset,
1016 				     u32 saved_val, int retry)
1017 {
1018 	u32 val;
1019 
1020 	pci_read_config_dword(pdev, offset, &val);
1021 	if (val == saved_val)
1022 		return;
1023 
1024 	for (;;) {
1025 		dev_dbg(&pdev->dev, "restoring config space at offset "
1026 			"%#x (was %#x, writing %#x)\n", offset, val, saved_val);
1027 		pci_write_config_dword(pdev, offset, saved_val);
1028 		if (retry-- <= 0)
1029 			return;
1030 
1031 		pci_read_config_dword(pdev, offset, &val);
1032 		if (val == saved_val)
1033 			return;
1034 
1035 		mdelay(1);
1036 	}
1037 }
1038 
1039 static void pci_restore_config_space_range(struct pci_dev *pdev,
1040 					   int start, int end, int retry)
1041 {
1042 	int index;
1043 
1044 	for (index = end; index >= start; index--)
1045 		pci_restore_config_dword(pdev, 4 * index,
1046 					 pdev->saved_config_space[index],
1047 					 retry);
1048 }
1049 
1050 static void pci_restore_config_space(struct pci_dev *pdev)
1051 {
1052 	if (pdev->hdr_type == PCI_HEADER_TYPE_NORMAL) {
1053 		pci_restore_config_space_range(pdev, 10, 15, 0);
1054 		/* Restore BARs before the command register. */
1055 		pci_restore_config_space_range(pdev, 4, 9, 10);
1056 		pci_restore_config_space_range(pdev, 0, 3, 0);
1057 	} else {
1058 		pci_restore_config_space_range(pdev, 0, 15, 0);
1059 	}
1060 }
1061 
1062 /**
1063  * pci_restore_state - Restore the saved state of a PCI device
1064  * @dev: - PCI device that we're dealing with
1065  */
1066 void pci_restore_state(struct pci_dev *dev)
1067 {
1068 	if (!dev->state_saved)
1069 		return;
1070 
1071 	/* PCI Express register must be restored first */
1072 	pci_restore_pcie_state(dev);
1073 	pci_restore_ats_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  * Rerturn 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 	struct hlist_node *pos;
1102 	size_t size;
1103 
1104 	if (!dev->state_saved)
1105 		return NULL;
1106 
1107 	size = sizeof(*state) + sizeof(struct pci_cap_saved_data);
1108 
1109 	hlist_for_each_entry(tmp, pos, &dev->saved_cap_space, next)
1110 		size += sizeof(struct pci_cap_saved_data) + tmp->cap.size;
1111 
1112 	state = kzalloc(size, GFP_KERNEL);
1113 	if (!state)
1114 		return NULL;
1115 
1116 	memcpy(state->config_space, dev->saved_config_space,
1117 	       sizeof(state->config_space));
1118 
1119 	cap = state->cap;
1120 	hlist_for_each_entry(tmp, pos, &dev->saved_cap_space, next) {
1121 		size_t len = sizeof(struct pci_cap_saved_data) + tmp->cap.size;
1122 		memcpy(cap, &tmp->cap, len);
1123 		cap = (struct pci_cap_saved_data *)((u8 *)cap + len);
1124 	}
1125 	/* Empty cap_save terminates list */
1126 
1127 	return state;
1128 }
1129 EXPORT_SYMBOL_GPL(pci_store_saved_state);
1130 
1131 /**
1132  * pci_load_saved_state - Reload the provided save state into struct pci_dev.
1133  * @dev: PCI device that we're dealing with
1134  * @state: Saved state returned from pci_store_saved_state()
1135  */
1136 int pci_load_saved_state(struct pci_dev *dev, 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);
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 EXPORT_SYMBOL_GPL(pci_load_saved_state);
1165 
1166 /**
1167  * pci_load_and_free_saved_state - Reload the save state pointed to by state,
1168  *				   and free the memory allocated for it.
1169  * @dev: PCI device that we're dealing with
1170  * @state: Pointer to saved state returned from pci_store_saved_state()
1171  */
1172 int pci_load_and_free_saved_state(struct pci_dev *dev,
1173 				  struct pci_saved_state **state)
1174 {
1175 	int ret = pci_load_saved_state(dev, *state);
1176 	kfree(*state);
1177 	*state = NULL;
1178 	return ret;
1179 }
1180 EXPORT_SYMBOL_GPL(pci_load_and_free_saved_state);
1181 
1182 static int do_pci_enable_device(struct pci_dev *dev, int bars)
1183 {
1184 	int err;
1185 
1186 	err = pci_set_power_state(dev, PCI_D0);
1187 	if (err < 0 && err != -EIO)
1188 		return err;
1189 	err = pcibios_enable_device(dev, bars);
1190 	if (err < 0)
1191 		return err;
1192 	pci_fixup_device(pci_fixup_enable, dev);
1193 
1194 	return 0;
1195 }
1196 
1197 /**
1198  * pci_reenable_device - Resume abandoned device
1199  * @dev: PCI device to be resumed
1200  *
1201  *  Note this function is a backend of pci_default_resume and is not supposed
1202  *  to be called by normal code, write proper resume handler and use it instead.
1203  */
1204 int pci_reenable_device(struct pci_dev *dev)
1205 {
1206 	if (pci_is_enabled(dev))
1207 		return do_pci_enable_device(dev, (1 << PCI_NUM_RESOURCES) - 1);
1208 	return 0;
1209 }
1210 
1211 static int __pci_enable_device_flags(struct pci_dev *dev,
1212 				     resource_size_t flags)
1213 {
1214 	int err;
1215 	int i, bars = 0;
1216 
1217 	/*
1218 	 * Power state could be unknown at this point, either due to a fresh
1219 	 * boot or a device removal call.  So get the current power state
1220 	 * so that things like MSI message writing will behave as expected
1221 	 * (e.g. if the device really is in D0 at enable time).
1222 	 */
1223 	if (dev->pm_cap) {
1224 		u16 pmcsr;
1225 		pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
1226 		dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
1227 	}
1228 
1229 	if (atomic_add_return(1, &dev->enable_cnt) > 1)
1230 		return 0;		/* already enabled */
1231 
1232 	/* only skip sriov related */
1233 	for (i = 0; i <= PCI_ROM_RESOURCE; i++)
1234 		if (dev->resource[i].flags & flags)
1235 			bars |= (1 << i);
1236 	for (i = PCI_BRIDGE_RESOURCES; i < DEVICE_COUNT_RESOURCE; i++)
1237 		if (dev->resource[i].flags & flags)
1238 			bars |= (1 << i);
1239 
1240 	err = do_pci_enable_device(dev, bars);
1241 	if (err < 0)
1242 		atomic_dec(&dev->enable_cnt);
1243 	return err;
1244 }
1245 
1246 /**
1247  * pci_enable_device_io - Initialize a device for use with IO space
1248  * @dev: PCI device to be initialized
1249  *
1250  *  Initialize device before it's used by a driver. Ask low-level code
1251  *  to enable I/O resources. Wake up the device if it was suspended.
1252  *  Beware, this function can fail.
1253  */
1254 int pci_enable_device_io(struct pci_dev *dev)
1255 {
1256 	return __pci_enable_device_flags(dev, IORESOURCE_IO);
1257 }
1258 
1259 /**
1260  * pci_enable_device_mem - Initialize a device for use with Memory space
1261  * @dev: PCI device to be initialized
1262  *
1263  *  Initialize device before it's used by a driver. Ask low-level code
1264  *  to enable Memory resources. Wake up the device if it was suspended.
1265  *  Beware, this function can fail.
1266  */
1267 int pci_enable_device_mem(struct pci_dev *dev)
1268 {
1269 	return __pci_enable_device_flags(dev, IORESOURCE_MEM);
1270 }
1271 
1272 /**
1273  * pci_enable_device - Initialize device before it's used by a driver.
1274  * @dev: PCI device to be initialized
1275  *
1276  *  Initialize device before it's used by a driver. Ask low-level code
1277  *  to enable I/O and memory. Wake up the device if it was suspended.
1278  *  Beware, this function can fail.
1279  *
1280  *  Note we don't actually enable the device many times if we call
1281  *  this function repeatedly (we just increment the count).
1282  */
1283 int pci_enable_device(struct pci_dev *dev)
1284 {
1285 	return __pci_enable_device_flags(dev, IORESOURCE_MEM | IORESOURCE_IO);
1286 }
1287 
1288 /*
1289  * Managed PCI resources.  This manages device on/off, intx/msi/msix
1290  * on/off and BAR regions.  pci_dev itself records msi/msix status, so
1291  * there's no need to track it separately.  pci_devres is initialized
1292  * when a device is enabled using managed PCI device enable interface.
1293  */
1294 struct pci_devres {
1295 	unsigned int enabled:1;
1296 	unsigned int pinned:1;
1297 	unsigned int orig_intx:1;
1298 	unsigned int restore_intx:1;
1299 	u32 region_mask;
1300 };
1301 
1302 static void pcim_release(struct device *gendev, void *res)
1303 {
1304 	struct pci_dev *dev = container_of(gendev, struct pci_dev, dev);
1305 	struct pci_devres *this = res;
1306 	int i;
1307 
1308 	if (dev->msi_enabled)
1309 		pci_disable_msi(dev);
1310 	if (dev->msix_enabled)
1311 		pci_disable_msix(dev);
1312 
1313 	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++)
1314 		if (this->region_mask & (1 << i))
1315 			pci_release_region(dev, i);
1316 
1317 	if (this->restore_intx)
1318 		pci_intx(dev, this->orig_intx);
1319 
1320 	if (this->enabled && !this->pinned)
1321 		pci_disable_device(dev);
1322 }
1323 
1324 static struct pci_devres * get_pci_dr(struct pci_dev *pdev)
1325 {
1326 	struct pci_devres *dr, *new_dr;
1327 
1328 	dr = devres_find(&pdev->dev, pcim_release, NULL, NULL);
1329 	if (dr)
1330 		return dr;
1331 
1332 	new_dr = devres_alloc(pcim_release, sizeof(*new_dr), GFP_KERNEL);
1333 	if (!new_dr)
1334 		return NULL;
1335 	return devres_get(&pdev->dev, new_dr, NULL, NULL);
1336 }
1337 
1338 static struct pci_devres * find_pci_dr(struct pci_dev *pdev)
1339 {
1340 	if (pci_is_managed(pdev))
1341 		return devres_find(&pdev->dev, pcim_release, NULL, NULL);
1342 	return NULL;
1343 }
1344 
1345 /**
1346  * pcim_enable_device - Managed pci_enable_device()
1347  * @pdev: PCI device to be initialized
1348  *
1349  * Managed pci_enable_device().
1350  */
1351 int pcim_enable_device(struct pci_dev *pdev)
1352 {
1353 	struct pci_devres *dr;
1354 	int rc;
1355 
1356 	dr = get_pci_dr(pdev);
1357 	if (unlikely(!dr))
1358 		return -ENOMEM;
1359 	if (dr->enabled)
1360 		return 0;
1361 
1362 	rc = pci_enable_device(pdev);
1363 	if (!rc) {
1364 		pdev->is_managed = 1;
1365 		dr->enabled = 1;
1366 	}
1367 	return rc;
1368 }
1369 
1370 /**
1371  * pcim_pin_device - Pin managed PCI device
1372  * @pdev: PCI device to pin
1373  *
1374  * Pin managed PCI device @pdev.  Pinned device won't be disabled on
1375  * driver detach.  @pdev must have been enabled with
1376  * pcim_enable_device().
1377  */
1378 void pcim_pin_device(struct pci_dev *pdev)
1379 {
1380 	struct pci_devres *dr;
1381 
1382 	dr = find_pci_dr(pdev);
1383 	WARN_ON(!dr || !dr->enabled);
1384 	if (dr)
1385 		dr->pinned = 1;
1386 }
1387 
1388 /**
1389  * pcibios_disable_device - disable arch specific PCI resources for device dev
1390  * @dev: the PCI device to disable
1391  *
1392  * Disables architecture specific PCI resources for the device. This
1393  * is the default implementation. Architecture implementations can
1394  * override this.
1395  */
1396 void __weak pcibios_disable_device (struct pci_dev *dev) {}
1397 
1398 static void do_pci_disable_device(struct pci_dev *dev)
1399 {
1400 	u16 pci_command;
1401 
1402 	pci_read_config_word(dev, PCI_COMMAND, &pci_command);
1403 	if (pci_command & PCI_COMMAND_MASTER) {
1404 		pci_command &= ~PCI_COMMAND_MASTER;
1405 		pci_write_config_word(dev, PCI_COMMAND, pci_command);
1406 	}
1407 
1408 	pcibios_disable_device(dev);
1409 }
1410 
1411 /**
1412  * pci_disable_enabled_device - Disable device without updating enable_cnt
1413  * @dev: PCI device to disable
1414  *
1415  * NOTE: This function is a backend of PCI power management routines and is
1416  * not supposed to be called drivers.
1417  */
1418 void pci_disable_enabled_device(struct pci_dev *dev)
1419 {
1420 	if (pci_is_enabled(dev))
1421 		do_pci_disable_device(dev);
1422 }
1423 
1424 /**
1425  * pci_disable_device - Disable PCI device after use
1426  * @dev: PCI device to be disabled
1427  *
1428  * Signal to the system that the PCI device is not in use by the system
1429  * anymore.  This only involves disabling PCI bus-mastering, if active.
1430  *
1431  * Note we don't actually disable the device until all callers of
1432  * pci_enable_device() have called pci_disable_device().
1433  */
1434 void
1435 pci_disable_device(struct pci_dev *dev)
1436 {
1437 	struct pci_devres *dr;
1438 
1439 	dr = find_pci_dr(dev);
1440 	if (dr)
1441 		dr->enabled = 0;
1442 
1443 	if (atomic_sub_return(1, &dev->enable_cnt) != 0)
1444 		return;
1445 
1446 	do_pci_disable_device(dev);
1447 
1448 	dev->is_busmaster = 0;
1449 }
1450 
1451 /**
1452  * pcibios_set_pcie_reset_state - set reset state for device dev
1453  * @dev: the PCIe device reset
1454  * @state: Reset state to enter into
1455  *
1456  *
1457  * Sets the PCIe reset state for the device. This is the default
1458  * implementation. Architecture implementations can override this.
1459  */
1460 int __weak pcibios_set_pcie_reset_state(struct pci_dev *dev,
1461 					enum pcie_reset_state state)
1462 {
1463 	return -EINVAL;
1464 }
1465 
1466 /**
1467  * pci_set_pcie_reset_state - set reset state for device dev
1468  * @dev: the PCIe device reset
1469  * @state: Reset state to enter into
1470  *
1471  *
1472  * Sets the PCI reset state for the device.
1473  */
1474 int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state)
1475 {
1476 	return pcibios_set_pcie_reset_state(dev, state);
1477 }
1478 
1479 /**
1480  * pci_check_pme_status - Check if given device has generated PME.
1481  * @dev: Device to check.
1482  *
1483  * Check the PME status of the device and if set, clear it and clear PME enable
1484  * (if set).  Return 'true' if PME status and PME enable were both set or
1485  * 'false' otherwise.
1486  */
1487 bool pci_check_pme_status(struct pci_dev *dev)
1488 {
1489 	int pmcsr_pos;
1490 	u16 pmcsr;
1491 	bool ret = false;
1492 
1493 	if (!dev->pm_cap)
1494 		return false;
1495 
1496 	pmcsr_pos = dev->pm_cap + PCI_PM_CTRL;
1497 	pci_read_config_word(dev, pmcsr_pos, &pmcsr);
1498 	if (!(pmcsr & PCI_PM_CTRL_PME_STATUS))
1499 		return false;
1500 
1501 	/* Clear PME status. */
1502 	pmcsr |= PCI_PM_CTRL_PME_STATUS;
1503 	if (pmcsr & PCI_PM_CTRL_PME_ENABLE) {
1504 		/* Disable PME to avoid interrupt flood. */
1505 		pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
1506 		ret = true;
1507 	}
1508 
1509 	pci_write_config_word(dev, pmcsr_pos, pmcsr);
1510 
1511 	return ret;
1512 }
1513 
1514 /**
1515  * pci_pme_wakeup - Wake up a PCI device if its PME Status bit is set.
1516  * @dev: Device to handle.
1517  * @pme_poll_reset: Whether or not to reset the device's pme_poll flag.
1518  *
1519  * Check if @dev has generated PME and queue a resume request for it in that
1520  * case.
1521  */
1522 static int pci_pme_wakeup(struct pci_dev *dev, void *pme_poll_reset)
1523 {
1524 	if (pme_poll_reset && dev->pme_poll)
1525 		dev->pme_poll = false;
1526 
1527 	if (pci_check_pme_status(dev)) {
1528 		pci_wakeup_event(dev);
1529 		pm_request_resume(&dev->dev);
1530 	}
1531 	return 0;
1532 }
1533 
1534 /**
1535  * pci_pme_wakeup_bus - Walk given bus and wake up devices on it, if necessary.
1536  * @bus: Top bus of the subtree to walk.
1537  */
1538 void pci_pme_wakeup_bus(struct pci_bus *bus)
1539 {
1540 	if (bus)
1541 		pci_walk_bus(bus, pci_pme_wakeup, (void *)true);
1542 }
1543 
1544 /**
1545  * pci_wakeup - Wake up a PCI device
1546  * @dev: Device to handle.
1547  * @ign: ignored parameter
1548  */
1549 static int pci_wakeup(struct pci_dev *pci_dev, void *ign)
1550 {
1551 	pci_wakeup_event(pci_dev);
1552 	pm_request_resume(&pci_dev->dev);
1553 	return 0;
1554 }
1555 
1556 /**
1557  * pci_wakeup_bus - Walk given bus and wake up devices on it
1558  * @bus: Top bus of the subtree to walk.
1559  */
1560 void pci_wakeup_bus(struct pci_bus *bus)
1561 {
1562 	if (bus)
1563 		pci_walk_bus(bus, pci_wakeup, NULL);
1564 }
1565 
1566 /**
1567  * pci_pme_capable - check the capability of PCI device to generate PME#
1568  * @dev: PCI device to handle.
1569  * @state: PCI state from which device will issue PME#.
1570  */
1571 bool pci_pme_capable(struct pci_dev *dev, pci_power_t state)
1572 {
1573 	if (!dev->pm_cap)
1574 		return false;
1575 
1576 	return !!(dev->pme_support & (1 << state));
1577 }
1578 
1579 static void pci_pme_list_scan(struct work_struct *work)
1580 {
1581 	struct pci_pme_device *pme_dev, *n;
1582 
1583 	mutex_lock(&pci_pme_list_mutex);
1584 	if (!list_empty(&pci_pme_list)) {
1585 		list_for_each_entry_safe(pme_dev, n, &pci_pme_list, list) {
1586 			if (pme_dev->dev->pme_poll) {
1587 				struct pci_dev *bridge;
1588 
1589 				bridge = pme_dev->dev->bus->self;
1590 				/*
1591 				 * If bridge is in low power state, the
1592 				 * configuration space of subordinate devices
1593 				 * may be not accessible
1594 				 */
1595 				if (bridge && bridge->current_state != PCI_D0)
1596 					continue;
1597 				pci_pme_wakeup(pme_dev->dev, NULL);
1598 			} else {
1599 				list_del(&pme_dev->list);
1600 				kfree(pme_dev);
1601 			}
1602 		}
1603 		if (!list_empty(&pci_pme_list))
1604 			schedule_delayed_work(&pci_pme_work,
1605 					      msecs_to_jiffies(PME_TIMEOUT));
1606 	}
1607 	mutex_unlock(&pci_pme_list_mutex);
1608 }
1609 
1610 /**
1611  * pci_pme_active - enable or disable PCI device's PME# function
1612  * @dev: PCI device to handle.
1613  * @enable: 'true' to enable PME# generation; 'false' to disable it.
1614  *
1615  * The caller must verify that the device is capable of generating PME# before
1616  * calling this function with @enable equal to 'true'.
1617  */
1618 void pci_pme_active(struct pci_dev *dev, bool enable)
1619 {
1620 	u16 pmcsr;
1621 
1622 	if (!dev->pm_cap)
1623 		return;
1624 
1625 	pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
1626 	/* Clear PME_Status by writing 1 to it and enable PME# */
1627 	pmcsr |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE;
1628 	if (!enable)
1629 		pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
1630 
1631 	pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
1632 
1633 	/* PCI (as opposed to PCIe) PME requires that the device have
1634 	   its PME# line hooked up correctly. Not all hardware vendors
1635 	   do this, so the PME never gets delivered and the device
1636 	   remains asleep. The easiest way around this is to
1637 	   periodically walk the list of suspended devices and check
1638 	   whether any have their PME flag set. The assumption is that
1639 	   we'll wake up often enough anyway that this won't be a huge
1640 	   hit, and the power savings from the devices will still be a
1641 	   win. */
1642 
1643 	if (dev->pme_poll) {
1644 		struct pci_pme_device *pme_dev;
1645 		if (enable) {
1646 			pme_dev = kmalloc(sizeof(struct pci_pme_device),
1647 					  GFP_KERNEL);
1648 			if (!pme_dev)
1649 				goto out;
1650 			pme_dev->dev = dev;
1651 			mutex_lock(&pci_pme_list_mutex);
1652 			list_add(&pme_dev->list, &pci_pme_list);
1653 			if (list_is_singular(&pci_pme_list))
1654 				schedule_delayed_work(&pci_pme_work,
1655 						      msecs_to_jiffies(PME_TIMEOUT));
1656 			mutex_unlock(&pci_pme_list_mutex);
1657 		} else {
1658 			mutex_lock(&pci_pme_list_mutex);
1659 			list_for_each_entry(pme_dev, &pci_pme_list, list) {
1660 				if (pme_dev->dev == dev) {
1661 					list_del(&pme_dev->list);
1662 					kfree(pme_dev);
1663 					break;
1664 				}
1665 			}
1666 			mutex_unlock(&pci_pme_list_mutex);
1667 		}
1668 	}
1669 
1670 out:
1671 	dev_dbg(&dev->dev, "PME# %s\n", enable ? "enabled" : "disabled");
1672 }
1673 
1674 /**
1675  * __pci_enable_wake - enable PCI device as wakeup event source
1676  * @dev: PCI device affected
1677  * @state: PCI state from which device will issue wakeup events
1678  * @runtime: True if the events are to be generated at run time
1679  * @enable: True to enable event generation; false to disable
1680  *
1681  * This enables the device as a wakeup event source, or disables it.
1682  * When such events involves platform-specific hooks, those hooks are
1683  * called automatically by this routine.
1684  *
1685  * Devices with legacy power management (no standard PCI PM capabilities)
1686  * always require such platform hooks.
1687  *
1688  * RETURN VALUE:
1689  * 0 is returned on success
1690  * -EINVAL is returned if device is not supposed to wake up the system
1691  * Error code depending on the platform is returned if both the platform and
1692  * the native mechanism fail to enable the generation of wake-up events
1693  */
1694 int __pci_enable_wake(struct pci_dev *dev, pci_power_t state,
1695 		      bool runtime, bool enable)
1696 {
1697 	int ret = 0;
1698 
1699 	if (enable && !runtime && !device_may_wakeup(&dev->dev))
1700 		return -EINVAL;
1701 
1702 	/* Don't do the same thing twice in a row for one device. */
1703 	if (!!enable == !!dev->wakeup_prepared)
1704 		return 0;
1705 
1706 	/*
1707 	 * According to "PCI System Architecture" 4th ed. by Tom Shanley & Don
1708 	 * Anderson we should be doing PME# wake enable followed by ACPI wake
1709 	 * enable.  To disable wake-up we call the platform first, for symmetry.
1710 	 */
1711 
1712 	if (enable) {
1713 		int error;
1714 
1715 		if (pci_pme_capable(dev, state))
1716 			pci_pme_active(dev, true);
1717 		else
1718 			ret = 1;
1719 		error = runtime ? platform_pci_run_wake(dev, true) :
1720 					platform_pci_sleep_wake(dev, true);
1721 		if (ret)
1722 			ret = error;
1723 		if (!ret)
1724 			dev->wakeup_prepared = true;
1725 	} else {
1726 		if (runtime)
1727 			platform_pci_run_wake(dev, false);
1728 		else
1729 			platform_pci_sleep_wake(dev, false);
1730 		pci_pme_active(dev, false);
1731 		dev->wakeup_prepared = false;
1732 	}
1733 
1734 	return ret;
1735 }
1736 EXPORT_SYMBOL(__pci_enable_wake);
1737 
1738 /**
1739  * pci_wake_from_d3 - enable/disable device to wake up from D3_hot or D3_cold
1740  * @dev: PCI device to prepare
1741  * @enable: True to enable wake-up event generation; false to disable
1742  *
1743  * Many drivers want the device to wake up the system from D3_hot or D3_cold
1744  * and this function allows them to set that up cleanly - pci_enable_wake()
1745  * should not be called twice in a row to enable wake-up due to PCI PM vs ACPI
1746  * ordering constraints.
1747  *
1748  * This function only returns error code if the device is not capable of
1749  * generating PME# from both D3_hot and D3_cold, and the platform is unable to
1750  * enable wake-up power for it.
1751  */
1752 int pci_wake_from_d3(struct pci_dev *dev, bool enable)
1753 {
1754 	return pci_pme_capable(dev, PCI_D3cold) ?
1755 			pci_enable_wake(dev, PCI_D3cold, enable) :
1756 			pci_enable_wake(dev, PCI_D3hot, enable);
1757 }
1758 
1759 /**
1760  * pci_target_state - find an appropriate low power state for a given PCI dev
1761  * @dev: PCI device
1762  *
1763  * Use underlying platform code to find a supported low power state for @dev.
1764  * If the platform can't manage @dev, return the deepest state from which it
1765  * can generate wake events, based on any available PME info.
1766  */
1767 pci_power_t pci_target_state(struct pci_dev *dev)
1768 {
1769 	pci_power_t target_state = PCI_D3hot;
1770 
1771 	if (platform_pci_power_manageable(dev)) {
1772 		/*
1773 		 * Call the platform to choose the target state of the device
1774 		 * and enable wake-up from this state if supported.
1775 		 */
1776 		pci_power_t state = platform_pci_choose_state(dev);
1777 
1778 		switch (state) {
1779 		case PCI_POWER_ERROR:
1780 		case PCI_UNKNOWN:
1781 			break;
1782 		case PCI_D1:
1783 		case PCI_D2:
1784 			if (pci_no_d1d2(dev))
1785 				break;
1786 		default:
1787 			target_state = state;
1788 		}
1789 	} else if (!dev->pm_cap) {
1790 		target_state = PCI_D0;
1791 	} else if (device_may_wakeup(&dev->dev)) {
1792 		/*
1793 		 * Find the deepest state from which the device can generate
1794 		 * wake-up events, make it the target state and enable device
1795 		 * to generate PME#.
1796 		 */
1797 		if (dev->pme_support) {
1798 			while (target_state
1799 			      && !(dev->pme_support & (1 << target_state)))
1800 				target_state--;
1801 		}
1802 	}
1803 
1804 	return target_state;
1805 }
1806 
1807 /**
1808  * pci_prepare_to_sleep - prepare PCI device for system-wide transition into a sleep state
1809  * @dev: Device to handle.
1810  *
1811  * Choose the power state appropriate for the device depending on whether
1812  * it can wake up the system and/or is power manageable by the platform
1813  * (PCI_D3hot is the default) and put the device into that state.
1814  */
1815 int pci_prepare_to_sleep(struct pci_dev *dev)
1816 {
1817 	pci_power_t target_state = pci_target_state(dev);
1818 	int error;
1819 
1820 	if (target_state == PCI_POWER_ERROR)
1821 		return -EIO;
1822 
1823 	/* D3cold during system suspend/hibernate is not supported */
1824 	if (target_state > PCI_D3hot)
1825 		target_state = PCI_D3hot;
1826 
1827 	pci_enable_wake(dev, target_state, device_may_wakeup(&dev->dev));
1828 
1829 	error = pci_set_power_state(dev, target_state);
1830 
1831 	if (error)
1832 		pci_enable_wake(dev, target_state, false);
1833 
1834 	return error;
1835 }
1836 
1837 /**
1838  * pci_back_from_sleep - turn PCI device on during system-wide transition into working state
1839  * @dev: Device to handle.
1840  *
1841  * Disable device's system wake-up capability and put it into D0.
1842  */
1843 int pci_back_from_sleep(struct pci_dev *dev)
1844 {
1845 	pci_enable_wake(dev, PCI_D0, false);
1846 	return pci_set_power_state(dev, PCI_D0);
1847 }
1848 
1849 /**
1850  * pci_finish_runtime_suspend - Carry out PCI-specific part of runtime suspend.
1851  * @dev: PCI device being suspended.
1852  *
1853  * Prepare @dev to generate wake-up events at run time and put it into a low
1854  * power state.
1855  */
1856 int pci_finish_runtime_suspend(struct pci_dev *dev)
1857 {
1858 	pci_power_t target_state = pci_target_state(dev);
1859 	int error;
1860 
1861 	if (target_state == PCI_POWER_ERROR)
1862 		return -EIO;
1863 
1864 	dev->runtime_d3cold = target_state == PCI_D3cold;
1865 
1866 	__pci_enable_wake(dev, target_state, true, pci_dev_run_wake(dev));
1867 
1868 	error = pci_set_power_state(dev, target_state);
1869 
1870 	if (error) {
1871 		__pci_enable_wake(dev, target_state, true, false);
1872 		dev->runtime_d3cold = false;
1873 	}
1874 
1875 	return error;
1876 }
1877 
1878 /**
1879  * pci_dev_run_wake - Check if device can generate run-time wake-up events.
1880  * @dev: Device to check.
1881  *
1882  * Return true if the device itself is cabable of generating wake-up events
1883  * (through the platform or using the native PCIe PME) or if the device supports
1884  * PME and one of its upstream bridges can generate wake-up events.
1885  */
1886 bool pci_dev_run_wake(struct pci_dev *dev)
1887 {
1888 	struct pci_bus *bus = dev->bus;
1889 
1890 	if (device_run_wake(&dev->dev))
1891 		return true;
1892 
1893 	if (!dev->pme_support)
1894 		return false;
1895 
1896 	while (bus->parent) {
1897 		struct pci_dev *bridge = bus->self;
1898 
1899 		if (device_run_wake(&bridge->dev))
1900 			return true;
1901 
1902 		bus = bus->parent;
1903 	}
1904 
1905 	/* We have reached the root bus. */
1906 	if (bus->bridge)
1907 		return device_run_wake(bus->bridge);
1908 
1909 	return false;
1910 }
1911 EXPORT_SYMBOL_GPL(pci_dev_run_wake);
1912 
1913 /**
1914  * pci_pm_init - Initialize PM functions of given PCI device
1915  * @dev: PCI device to handle.
1916  */
1917 void pci_pm_init(struct pci_dev *dev)
1918 {
1919 	int pm;
1920 	u16 pmc;
1921 
1922 	pm_runtime_forbid(&dev->dev);
1923 	device_enable_async_suspend(&dev->dev);
1924 	dev->wakeup_prepared = false;
1925 
1926 	dev->pm_cap = 0;
1927 
1928 	/* find PCI PM capability in list */
1929 	pm = pci_find_capability(dev, PCI_CAP_ID_PM);
1930 	if (!pm)
1931 		return;
1932 	/* Check device's ability to generate PME# */
1933 	pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
1934 
1935 	if ((pmc & PCI_PM_CAP_VER_MASK) > 3) {
1936 		dev_err(&dev->dev, "unsupported PM cap regs version (%u)\n",
1937 			pmc & PCI_PM_CAP_VER_MASK);
1938 		return;
1939 	}
1940 
1941 	dev->pm_cap = pm;
1942 	dev->d3_delay = PCI_PM_D3_WAIT;
1943 	dev->d3cold_delay = PCI_PM_D3COLD_WAIT;
1944 	dev->d3cold_allowed = true;
1945 
1946 	dev->d1_support = false;
1947 	dev->d2_support = false;
1948 	if (!pci_no_d1d2(dev)) {
1949 		if (pmc & PCI_PM_CAP_D1)
1950 			dev->d1_support = true;
1951 		if (pmc & PCI_PM_CAP_D2)
1952 			dev->d2_support = true;
1953 
1954 		if (dev->d1_support || dev->d2_support)
1955 			dev_printk(KERN_DEBUG, &dev->dev, "supports%s%s\n",
1956 				   dev->d1_support ? " D1" : "",
1957 				   dev->d2_support ? " D2" : "");
1958 	}
1959 
1960 	pmc &= PCI_PM_CAP_PME_MASK;
1961 	if (pmc) {
1962 		dev_printk(KERN_DEBUG, &dev->dev,
1963 			 "PME# supported from%s%s%s%s%s\n",
1964 			 (pmc & PCI_PM_CAP_PME_D0) ? " D0" : "",
1965 			 (pmc & PCI_PM_CAP_PME_D1) ? " D1" : "",
1966 			 (pmc & PCI_PM_CAP_PME_D2) ? " D2" : "",
1967 			 (pmc & PCI_PM_CAP_PME_D3) ? " D3hot" : "",
1968 			 (pmc & PCI_PM_CAP_PME_D3cold) ? " D3cold" : "");
1969 		dev->pme_support = pmc >> PCI_PM_CAP_PME_SHIFT;
1970 		dev->pme_poll = true;
1971 		/*
1972 		 * Make device's PM flags reflect the wake-up capability, but
1973 		 * let the user space enable it to wake up the system as needed.
1974 		 */
1975 		device_set_wakeup_capable(&dev->dev, true);
1976 		/* Disable the PME# generation functionality */
1977 		pci_pme_active(dev, false);
1978 	} else {
1979 		dev->pme_support = 0;
1980 	}
1981 }
1982 
1983 /**
1984  * platform_pci_wakeup_init - init platform wakeup if present
1985  * @dev: PCI device
1986  *
1987  * Some devices don't have PCI PM caps but can still generate wakeup
1988  * events through platform methods (like ACPI events).  If @dev supports
1989  * platform wakeup events, set the device flag to indicate as much.  This
1990  * may be redundant if the device also supports PCI PM caps, but double
1991  * initialization should be safe in that case.
1992  */
1993 void platform_pci_wakeup_init(struct pci_dev *dev)
1994 {
1995 	if (!platform_pci_can_wakeup(dev))
1996 		return;
1997 
1998 	device_set_wakeup_capable(&dev->dev, true);
1999 	platform_pci_sleep_wake(dev, false);
2000 }
2001 
2002 static void pci_add_saved_cap(struct pci_dev *pci_dev,
2003 	struct pci_cap_saved_state *new_cap)
2004 {
2005 	hlist_add_head(&new_cap->next, &pci_dev->saved_cap_space);
2006 }
2007 
2008 /**
2009  * pci_add_save_buffer - allocate buffer for saving given capability registers
2010  * @dev: the PCI device
2011  * @cap: the capability to allocate the buffer for
2012  * @size: requested size of the buffer
2013  */
2014 static int pci_add_cap_save_buffer(
2015 	struct pci_dev *dev, char cap, unsigned int size)
2016 {
2017 	int pos;
2018 	struct pci_cap_saved_state *save_state;
2019 
2020 	pos = pci_find_capability(dev, cap);
2021 	if (pos <= 0)
2022 		return 0;
2023 
2024 	save_state = kzalloc(sizeof(*save_state) + size, GFP_KERNEL);
2025 	if (!save_state)
2026 		return -ENOMEM;
2027 
2028 	save_state->cap.cap_nr = cap;
2029 	save_state->cap.size = size;
2030 	pci_add_saved_cap(dev, save_state);
2031 
2032 	return 0;
2033 }
2034 
2035 /**
2036  * pci_allocate_cap_save_buffers - allocate buffers for saving capabilities
2037  * @dev: the PCI device
2038  */
2039 void pci_allocate_cap_save_buffers(struct pci_dev *dev)
2040 {
2041 	int error;
2042 
2043 	error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_EXP,
2044 					PCI_EXP_SAVE_REGS * sizeof(u16));
2045 	if (error)
2046 		dev_err(&dev->dev,
2047 			"unable to preallocate PCI Express save buffer\n");
2048 
2049 	error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_PCIX, sizeof(u16));
2050 	if (error)
2051 		dev_err(&dev->dev,
2052 			"unable to preallocate PCI-X save buffer\n");
2053 }
2054 
2055 void pci_free_cap_save_buffers(struct pci_dev *dev)
2056 {
2057 	struct pci_cap_saved_state *tmp;
2058 	struct hlist_node *pos, *n;
2059 
2060 	hlist_for_each_entry_safe(tmp, pos, n, &dev->saved_cap_space, next)
2061 		kfree(tmp);
2062 }
2063 
2064 /**
2065  * pci_enable_ari - enable ARI forwarding if hardware support it
2066  * @dev: the PCI device
2067  */
2068 void pci_enable_ari(struct pci_dev *dev)
2069 {
2070 	int pos;
2071 	u32 cap;
2072 	u16 ctrl;
2073 	struct pci_dev *bridge;
2074 
2075 	if (pcie_ari_disabled || !pci_is_pcie(dev) || dev->devfn)
2076 		return;
2077 
2078 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI);
2079 	if (!pos)
2080 		return;
2081 
2082 	bridge = dev->bus->self;
2083 	if (!bridge)
2084 		return;
2085 
2086 	/* ARI is a PCIe cap v2 feature */
2087 	pos = pci_pcie_cap2(bridge);
2088 	if (!pos)
2089 		return;
2090 
2091 	pci_read_config_dword(bridge, pos + PCI_EXP_DEVCAP2, &cap);
2092 	if (!(cap & PCI_EXP_DEVCAP2_ARI))
2093 		return;
2094 
2095 	pci_read_config_word(bridge, pos + PCI_EXP_DEVCTL2, &ctrl);
2096 	ctrl |= PCI_EXP_DEVCTL2_ARI;
2097 	pci_write_config_word(bridge, pos + PCI_EXP_DEVCTL2, ctrl);
2098 
2099 	bridge->ari_enabled = 1;
2100 }
2101 
2102 /**
2103  * pci_enable_ido - enable ID-based Ordering on a device
2104  * @dev: the PCI device
2105  * @type: which types of IDO to enable
2106  *
2107  * Enable ID-based ordering on @dev.  @type can contain the bits
2108  * %PCI_EXP_IDO_REQUEST and/or %PCI_EXP_IDO_COMPLETION to indicate
2109  * which types of transactions are allowed to be re-ordered.
2110  */
2111 void pci_enable_ido(struct pci_dev *dev, unsigned long type)
2112 {
2113 	int pos;
2114 	u16 ctrl;
2115 
2116 	/* ID-based Ordering is a PCIe cap v2 feature */
2117 	pos = pci_pcie_cap2(dev);
2118 	if (!pos)
2119 		return;
2120 
2121 	pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &ctrl);
2122 	if (type & PCI_EXP_IDO_REQUEST)
2123 		ctrl |= PCI_EXP_IDO_REQ_EN;
2124 	if (type & PCI_EXP_IDO_COMPLETION)
2125 		ctrl |= PCI_EXP_IDO_CMP_EN;
2126 	pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, ctrl);
2127 }
2128 EXPORT_SYMBOL(pci_enable_ido);
2129 
2130 /**
2131  * pci_disable_ido - disable ID-based ordering on a device
2132  * @dev: the PCI device
2133  * @type: which types of IDO to disable
2134  */
2135 void pci_disable_ido(struct pci_dev *dev, unsigned long type)
2136 {
2137 	int pos;
2138 	u16 ctrl;
2139 
2140 	/* ID-based Ordering is a PCIe cap v2 feature */
2141 	pos = pci_pcie_cap2(dev);
2142 	if (!pos)
2143 		return;
2144 
2145 	pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &ctrl);
2146 	if (type & PCI_EXP_IDO_REQUEST)
2147 		ctrl &= ~PCI_EXP_IDO_REQ_EN;
2148 	if (type & PCI_EXP_IDO_COMPLETION)
2149 		ctrl &= ~PCI_EXP_IDO_CMP_EN;
2150 	pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, ctrl);
2151 }
2152 EXPORT_SYMBOL(pci_disable_ido);
2153 
2154 /**
2155  * pci_enable_obff - enable optimized buffer flush/fill
2156  * @dev: PCI device
2157  * @type: type of signaling to use
2158  *
2159  * Try to enable @type OBFF signaling on @dev.  It will try using WAKE#
2160  * signaling if possible, falling back to message signaling only if
2161  * WAKE# isn't supported.  @type should indicate whether the PCIe link
2162  * be brought out of L0s or L1 to send the message.  It should be either
2163  * %PCI_EXP_OBFF_SIGNAL_ALWAYS or %PCI_OBFF_SIGNAL_L0.
2164  *
2165  * If your device can benefit from receiving all messages, even at the
2166  * power cost of bringing the link back up from a low power state, use
2167  * %PCI_EXP_OBFF_SIGNAL_ALWAYS.  Otherwise, use %PCI_OBFF_SIGNAL_L0 (the
2168  * preferred type).
2169  *
2170  * RETURNS:
2171  * Zero on success, appropriate error number on failure.
2172  */
2173 int pci_enable_obff(struct pci_dev *dev, enum pci_obff_signal_type type)
2174 {
2175 	int pos;
2176 	u32 cap;
2177 	u16 ctrl;
2178 	int ret;
2179 
2180 	/* OBFF is a PCIe cap v2 feature */
2181 	pos = pci_pcie_cap2(dev);
2182 	if (!pos)
2183 		return -ENOTSUPP;
2184 
2185 	pci_read_config_dword(dev, pos + PCI_EXP_DEVCAP2, &cap);
2186 	if (!(cap & PCI_EXP_OBFF_MASK))
2187 		return -ENOTSUPP; /* no OBFF support at all */
2188 
2189 	/* Make sure the topology supports OBFF as well */
2190 	if (dev->bus->self) {
2191 		ret = pci_enable_obff(dev->bus->self, type);
2192 		if (ret)
2193 			return ret;
2194 	}
2195 
2196 	pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &ctrl);
2197 	if (cap & PCI_EXP_OBFF_WAKE)
2198 		ctrl |= PCI_EXP_OBFF_WAKE_EN;
2199 	else {
2200 		switch (type) {
2201 		case PCI_EXP_OBFF_SIGNAL_L0:
2202 			if (!(ctrl & PCI_EXP_OBFF_WAKE_EN))
2203 				ctrl |= PCI_EXP_OBFF_MSGA_EN;
2204 			break;
2205 		case PCI_EXP_OBFF_SIGNAL_ALWAYS:
2206 			ctrl &= ~PCI_EXP_OBFF_WAKE_EN;
2207 			ctrl |= PCI_EXP_OBFF_MSGB_EN;
2208 			break;
2209 		default:
2210 			WARN(1, "bad OBFF signal type\n");
2211 			return -ENOTSUPP;
2212 		}
2213 	}
2214 	pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, ctrl);
2215 
2216 	return 0;
2217 }
2218 EXPORT_SYMBOL(pci_enable_obff);
2219 
2220 /**
2221  * pci_disable_obff - disable optimized buffer flush/fill
2222  * @dev: PCI device
2223  *
2224  * Disable OBFF on @dev.
2225  */
2226 void pci_disable_obff(struct pci_dev *dev)
2227 {
2228 	int pos;
2229 	u16 ctrl;
2230 
2231 	/* OBFF is a PCIe cap v2 feature */
2232 	pos = pci_pcie_cap2(dev);
2233 	if (!pos)
2234 		return;
2235 
2236 	pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &ctrl);
2237 	ctrl &= ~PCI_EXP_OBFF_WAKE_EN;
2238 	pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, ctrl);
2239 }
2240 EXPORT_SYMBOL(pci_disable_obff);
2241 
2242 /**
2243  * pci_ltr_supported - check whether a device supports LTR
2244  * @dev: PCI device
2245  *
2246  * RETURNS:
2247  * True if @dev supports latency tolerance reporting, false otherwise.
2248  */
2249 static bool pci_ltr_supported(struct pci_dev *dev)
2250 {
2251 	int pos;
2252 	u32 cap;
2253 
2254 	/* LTR is a PCIe cap v2 feature */
2255 	pos = pci_pcie_cap2(dev);
2256 	if (!pos)
2257 		return false;
2258 
2259 	pci_read_config_dword(dev, pos + PCI_EXP_DEVCAP2, &cap);
2260 
2261 	return cap & PCI_EXP_DEVCAP2_LTR;
2262 }
2263 
2264 /**
2265  * pci_enable_ltr - enable latency tolerance reporting
2266  * @dev: PCI device
2267  *
2268  * Enable LTR on @dev if possible, which means enabling it first on
2269  * upstream ports.
2270  *
2271  * RETURNS:
2272  * Zero on success, errno on failure.
2273  */
2274 int pci_enable_ltr(struct pci_dev *dev)
2275 {
2276 	int pos;
2277 	u16 ctrl;
2278 	int ret;
2279 
2280 	if (!pci_ltr_supported(dev))
2281 		return -ENOTSUPP;
2282 
2283 	/* LTR is a PCIe cap v2 feature */
2284 	pos = pci_pcie_cap2(dev);
2285 	if (!pos)
2286 		return -ENOTSUPP;
2287 
2288 	/* Only primary function can enable/disable LTR */
2289 	if (PCI_FUNC(dev->devfn) != 0)
2290 		return -EINVAL;
2291 
2292 	/* Enable upstream ports first */
2293 	if (dev->bus->self) {
2294 		ret = pci_enable_ltr(dev->bus->self);
2295 		if (ret)
2296 			return ret;
2297 	}
2298 
2299 	pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &ctrl);
2300 	ctrl |= PCI_EXP_LTR_EN;
2301 	pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, ctrl);
2302 
2303 	return 0;
2304 }
2305 EXPORT_SYMBOL(pci_enable_ltr);
2306 
2307 /**
2308  * pci_disable_ltr - disable latency tolerance reporting
2309  * @dev: PCI device
2310  */
2311 void pci_disable_ltr(struct pci_dev *dev)
2312 {
2313 	int pos;
2314 	u16 ctrl;
2315 
2316 	if (!pci_ltr_supported(dev))
2317 		return;
2318 
2319 	/* LTR is a PCIe cap v2 feature */
2320 	pos = pci_pcie_cap2(dev);
2321 	if (!pos)
2322 		return;
2323 
2324 	/* Only primary function can enable/disable LTR */
2325 	if (PCI_FUNC(dev->devfn) != 0)
2326 		return;
2327 
2328 	pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &ctrl);
2329 	ctrl &= ~PCI_EXP_LTR_EN;
2330 	pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, ctrl);
2331 }
2332 EXPORT_SYMBOL(pci_disable_ltr);
2333 
2334 static int __pci_ltr_scale(int *val)
2335 {
2336 	int scale = 0;
2337 
2338 	while (*val > 1023) {
2339 		*val = (*val + 31) / 32;
2340 		scale++;
2341 	}
2342 	return scale;
2343 }
2344 
2345 /**
2346  * pci_set_ltr - set LTR latency values
2347  * @dev: PCI device
2348  * @snoop_lat_ns: snoop latency in nanoseconds
2349  * @nosnoop_lat_ns: nosnoop latency in nanoseconds
2350  *
2351  * Figure out the scale and set the LTR values accordingly.
2352  */
2353 int pci_set_ltr(struct pci_dev *dev, int snoop_lat_ns, int nosnoop_lat_ns)
2354 {
2355 	int pos, ret, snoop_scale, nosnoop_scale;
2356 	u16 val;
2357 
2358 	if (!pci_ltr_supported(dev))
2359 		return -ENOTSUPP;
2360 
2361 	snoop_scale = __pci_ltr_scale(&snoop_lat_ns);
2362 	nosnoop_scale = __pci_ltr_scale(&nosnoop_lat_ns);
2363 
2364 	if (snoop_lat_ns > PCI_LTR_VALUE_MASK ||
2365 	    nosnoop_lat_ns > PCI_LTR_VALUE_MASK)
2366 		return -EINVAL;
2367 
2368 	if ((snoop_scale > (PCI_LTR_SCALE_MASK >> PCI_LTR_SCALE_SHIFT)) ||
2369 	    (nosnoop_scale > (PCI_LTR_SCALE_MASK >> PCI_LTR_SCALE_SHIFT)))
2370 		return -EINVAL;
2371 
2372 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR);
2373 	if (!pos)
2374 		return -ENOTSUPP;
2375 
2376 	val = (snoop_scale << PCI_LTR_SCALE_SHIFT) | snoop_lat_ns;
2377 	ret = pci_write_config_word(dev, pos + PCI_LTR_MAX_SNOOP_LAT, val);
2378 	if (ret != 4)
2379 		return -EIO;
2380 
2381 	val = (nosnoop_scale << PCI_LTR_SCALE_SHIFT) | nosnoop_lat_ns;
2382 	ret = pci_write_config_word(dev, pos + PCI_LTR_MAX_NOSNOOP_LAT, val);
2383 	if (ret != 4)
2384 		return -EIO;
2385 
2386 	return 0;
2387 }
2388 EXPORT_SYMBOL(pci_set_ltr);
2389 
2390 static int pci_acs_enable;
2391 
2392 /**
2393  * pci_request_acs - ask for ACS to be enabled if supported
2394  */
2395 void pci_request_acs(void)
2396 {
2397 	pci_acs_enable = 1;
2398 }
2399 
2400 /**
2401  * pci_enable_acs - enable ACS if hardware support it
2402  * @dev: the PCI device
2403  */
2404 void pci_enable_acs(struct pci_dev *dev)
2405 {
2406 	int pos;
2407 	u16 cap;
2408 	u16 ctrl;
2409 
2410 	if (!pci_acs_enable)
2411 		return;
2412 
2413 	if (!pci_is_pcie(dev))
2414 		return;
2415 
2416 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS);
2417 	if (!pos)
2418 		return;
2419 
2420 	pci_read_config_word(dev, pos + PCI_ACS_CAP, &cap);
2421 	pci_read_config_word(dev, pos + PCI_ACS_CTRL, &ctrl);
2422 
2423 	/* Source Validation */
2424 	ctrl |= (cap & PCI_ACS_SV);
2425 
2426 	/* P2P Request Redirect */
2427 	ctrl |= (cap & PCI_ACS_RR);
2428 
2429 	/* P2P Completion Redirect */
2430 	ctrl |= (cap & PCI_ACS_CR);
2431 
2432 	/* Upstream Forwarding */
2433 	ctrl |= (cap & PCI_ACS_UF);
2434 
2435 	pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl);
2436 }
2437 
2438 /**
2439  * pci_acs_enabled - test ACS against required flags for a given device
2440  * @pdev: device to test
2441  * @acs_flags: required PCI ACS flags
2442  *
2443  * Return true if the device supports the provided flags.  Automatically
2444  * filters out flags that are not implemented on multifunction devices.
2445  */
2446 bool pci_acs_enabled(struct pci_dev *pdev, u16 acs_flags)
2447 {
2448 	int pos, ret;
2449 	u16 ctrl;
2450 
2451 	ret = pci_dev_specific_acs_enabled(pdev, acs_flags);
2452 	if (ret >= 0)
2453 		return ret > 0;
2454 
2455 	if (!pci_is_pcie(pdev))
2456 		return false;
2457 
2458 	/* Filter out flags not applicable to multifunction */
2459 	if (pdev->multifunction)
2460 		acs_flags &= (PCI_ACS_RR | PCI_ACS_CR |
2461 			      PCI_ACS_EC | PCI_ACS_DT);
2462 
2463 	if (pdev->pcie_type == PCI_EXP_TYPE_DOWNSTREAM ||
2464 	    pdev->pcie_type == PCI_EXP_TYPE_ROOT_PORT ||
2465 	    pdev->multifunction) {
2466 		pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ACS);
2467 		if (!pos)
2468 			return false;
2469 
2470 		pci_read_config_word(pdev, pos + PCI_ACS_CTRL, &ctrl);
2471 		if ((ctrl & acs_flags) != acs_flags)
2472 			return false;
2473 	}
2474 
2475 	return true;
2476 }
2477 
2478 /**
2479  * pci_acs_path_enable - test ACS flags from start to end in a hierarchy
2480  * @start: starting downstream device
2481  * @end: ending upstream device or NULL to search to the root bus
2482  * @acs_flags: required flags
2483  *
2484  * Walk up a device tree from start to end testing PCI ACS support.  If
2485  * any step along the way does not support the required flags, return false.
2486  */
2487 bool pci_acs_path_enabled(struct pci_dev *start,
2488 			  struct pci_dev *end, u16 acs_flags)
2489 {
2490 	struct pci_dev *pdev, *parent = start;
2491 
2492 	do {
2493 		pdev = parent;
2494 
2495 		if (!pci_acs_enabled(pdev, acs_flags))
2496 			return false;
2497 
2498 		if (pci_is_root_bus(pdev->bus))
2499 			return (end == NULL);
2500 
2501 		parent = pdev->bus->self;
2502 	} while (pdev != end);
2503 
2504 	return true;
2505 }
2506 
2507 /**
2508  * pci_swizzle_interrupt_pin - swizzle INTx for device behind bridge
2509  * @dev: the PCI device
2510  * @pin: the INTx pin (1=INTA, 2=INTB, 3=INTD, 4=INTD)
2511  *
2512  * Perform INTx swizzling for a device behind one level of bridge.  This is
2513  * required by section 9.1 of the PCI-to-PCI bridge specification for devices
2514  * behind bridges on add-in cards.  For devices with ARI enabled, the slot
2515  * number is always 0 (see the Implementation Note in section 2.2.8.1 of
2516  * the PCI Express Base Specification, Revision 2.1)
2517  */
2518 u8 pci_swizzle_interrupt_pin(const struct pci_dev *dev, u8 pin)
2519 {
2520 	int slot;
2521 
2522 	if (pci_ari_enabled(dev->bus))
2523 		slot = 0;
2524 	else
2525 		slot = PCI_SLOT(dev->devfn);
2526 
2527 	return (((pin - 1) + slot) % 4) + 1;
2528 }
2529 
2530 int
2531 pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge)
2532 {
2533 	u8 pin;
2534 
2535 	pin = dev->pin;
2536 	if (!pin)
2537 		return -1;
2538 
2539 	while (!pci_is_root_bus(dev->bus)) {
2540 		pin = pci_swizzle_interrupt_pin(dev, pin);
2541 		dev = dev->bus->self;
2542 	}
2543 	*bridge = dev;
2544 	return pin;
2545 }
2546 
2547 /**
2548  * pci_common_swizzle - swizzle INTx all the way to root bridge
2549  * @dev: the PCI device
2550  * @pinp: pointer to the INTx pin value (1=INTA, 2=INTB, 3=INTD, 4=INTD)
2551  *
2552  * Perform INTx swizzling for a device.  This traverses through all PCI-to-PCI
2553  * bridges all the way up to a PCI root bus.
2554  */
2555 u8 pci_common_swizzle(struct pci_dev *dev, u8 *pinp)
2556 {
2557 	u8 pin = *pinp;
2558 
2559 	while (!pci_is_root_bus(dev->bus)) {
2560 		pin = pci_swizzle_interrupt_pin(dev, pin);
2561 		dev = dev->bus->self;
2562 	}
2563 	*pinp = pin;
2564 	return PCI_SLOT(dev->devfn);
2565 }
2566 
2567 /**
2568  *	pci_release_region - Release a PCI bar
2569  *	@pdev: PCI device whose resources were previously reserved by pci_request_region
2570  *	@bar: BAR to release
2571  *
2572  *	Releases the PCI I/O and memory resources previously reserved by a
2573  *	successful call to pci_request_region.  Call this function only
2574  *	after all use of the PCI regions has ceased.
2575  */
2576 void pci_release_region(struct pci_dev *pdev, int bar)
2577 {
2578 	struct pci_devres *dr;
2579 
2580 	if (pci_resource_len(pdev, bar) == 0)
2581 		return;
2582 	if (pci_resource_flags(pdev, bar) & IORESOURCE_IO)
2583 		release_region(pci_resource_start(pdev, bar),
2584 				pci_resource_len(pdev, bar));
2585 	else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM)
2586 		release_mem_region(pci_resource_start(pdev, bar),
2587 				pci_resource_len(pdev, bar));
2588 
2589 	dr = find_pci_dr(pdev);
2590 	if (dr)
2591 		dr->region_mask &= ~(1 << bar);
2592 }
2593 
2594 /**
2595  *	__pci_request_region - Reserved PCI I/O and memory resource
2596  *	@pdev: PCI device whose resources are to be reserved
2597  *	@bar: BAR to be reserved
2598  *	@res_name: Name to be associated with resource.
2599  *	@exclusive: whether the region access is exclusive or not
2600  *
2601  *	Mark the PCI region associated with PCI device @pdev BR @bar as
2602  *	being reserved by owner @res_name.  Do not access any
2603  *	address inside the PCI regions unless this call returns
2604  *	successfully.
2605  *
2606  *	If @exclusive is set, then the region is marked so that userspace
2607  *	is explicitly not allowed to map the resource via /dev/mem or
2608  * 	sysfs MMIO access.
2609  *
2610  *	Returns 0 on success, or %EBUSY on error.  A warning
2611  *	message is also printed on failure.
2612  */
2613 static int __pci_request_region(struct pci_dev *pdev, int bar, const char *res_name,
2614 									int exclusive)
2615 {
2616 	struct pci_devres *dr;
2617 
2618 	if (pci_resource_len(pdev, bar) == 0)
2619 		return 0;
2620 
2621 	if (pci_resource_flags(pdev, bar) & IORESOURCE_IO) {
2622 		if (!request_region(pci_resource_start(pdev, bar),
2623 			    pci_resource_len(pdev, bar), res_name))
2624 			goto err_out;
2625 	}
2626 	else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM) {
2627 		if (!__request_mem_region(pci_resource_start(pdev, bar),
2628 					pci_resource_len(pdev, bar), res_name,
2629 					exclusive))
2630 			goto err_out;
2631 	}
2632 
2633 	dr = find_pci_dr(pdev);
2634 	if (dr)
2635 		dr->region_mask |= 1 << bar;
2636 
2637 	return 0;
2638 
2639 err_out:
2640 	dev_warn(&pdev->dev, "BAR %d: can't reserve %pR\n", bar,
2641 		 &pdev->resource[bar]);
2642 	return -EBUSY;
2643 }
2644 
2645 /**
2646  *	pci_request_region - Reserve PCI I/O and memory resource
2647  *	@pdev: PCI device whose resources are to be reserved
2648  *	@bar: BAR to be reserved
2649  *	@res_name: Name to be associated with resource
2650  *
2651  *	Mark the PCI region associated with PCI device @pdev BAR @bar as
2652  *	being reserved by owner @res_name.  Do not access any
2653  *	address inside the PCI regions unless this call returns
2654  *	successfully.
2655  *
2656  *	Returns 0 on success, or %EBUSY on error.  A warning
2657  *	message is also printed on failure.
2658  */
2659 int pci_request_region(struct pci_dev *pdev, int bar, const char *res_name)
2660 {
2661 	return __pci_request_region(pdev, bar, res_name, 0);
2662 }
2663 
2664 /**
2665  *	pci_request_region_exclusive - Reserved PCI I/O and memory resource
2666  *	@pdev: PCI device whose resources are to be reserved
2667  *	@bar: BAR to be reserved
2668  *	@res_name: Name to be associated with resource.
2669  *
2670  *	Mark the PCI region associated with PCI device @pdev BR @bar as
2671  *	being reserved by owner @res_name.  Do not access any
2672  *	address inside the PCI regions unless this call returns
2673  *	successfully.
2674  *
2675  *	Returns 0 on success, or %EBUSY on error.  A warning
2676  *	message is also printed on failure.
2677  *
2678  *	The key difference that _exclusive makes it that userspace is
2679  *	explicitly not allowed to map the resource via /dev/mem or
2680  * 	sysfs.
2681  */
2682 int pci_request_region_exclusive(struct pci_dev *pdev, int bar, const char *res_name)
2683 {
2684 	return __pci_request_region(pdev, bar, res_name, IORESOURCE_EXCLUSIVE);
2685 }
2686 /**
2687  * pci_release_selected_regions - Release selected PCI I/O and memory resources
2688  * @pdev: PCI device whose resources were previously reserved
2689  * @bars: Bitmask of BARs to be released
2690  *
2691  * Release selected PCI I/O and memory resources previously reserved.
2692  * Call this function only after all use of the PCI regions has ceased.
2693  */
2694 void pci_release_selected_regions(struct pci_dev *pdev, int bars)
2695 {
2696 	int i;
2697 
2698 	for (i = 0; i < 6; i++)
2699 		if (bars & (1 << i))
2700 			pci_release_region(pdev, i);
2701 }
2702 
2703 int __pci_request_selected_regions(struct pci_dev *pdev, int bars,
2704 				 const char *res_name, int excl)
2705 {
2706 	int i;
2707 
2708 	for (i = 0; i < 6; i++)
2709 		if (bars & (1 << i))
2710 			if (__pci_request_region(pdev, i, res_name, excl))
2711 				goto err_out;
2712 	return 0;
2713 
2714 err_out:
2715 	while(--i >= 0)
2716 		if (bars & (1 << i))
2717 			pci_release_region(pdev, i);
2718 
2719 	return -EBUSY;
2720 }
2721 
2722 
2723 /**
2724  * pci_request_selected_regions - Reserve selected PCI I/O and memory resources
2725  * @pdev: PCI device whose resources are to be reserved
2726  * @bars: Bitmask of BARs to be requested
2727  * @res_name: Name to be associated with resource
2728  */
2729 int pci_request_selected_regions(struct pci_dev *pdev, int bars,
2730 				 const char *res_name)
2731 {
2732 	return __pci_request_selected_regions(pdev, bars, res_name, 0);
2733 }
2734 
2735 int pci_request_selected_regions_exclusive(struct pci_dev *pdev,
2736 				 int bars, const char *res_name)
2737 {
2738 	return __pci_request_selected_regions(pdev, bars, res_name,
2739 			IORESOURCE_EXCLUSIVE);
2740 }
2741 
2742 /**
2743  *	pci_release_regions - Release reserved PCI I/O and memory resources
2744  *	@pdev: PCI device whose resources were previously reserved by pci_request_regions
2745  *
2746  *	Releases all PCI I/O and memory resources previously reserved by a
2747  *	successful call to pci_request_regions.  Call this function only
2748  *	after all use of the PCI regions has ceased.
2749  */
2750 
2751 void pci_release_regions(struct pci_dev *pdev)
2752 {
2753 	pci_release_selected_regions(pdev, (1 << 6) - 1);
2754 }
2755 
2756 /**
2757  *	pci_request_regions - Reserved PCI I/O and memory resources
2758  *	@pdev: PCI device whose resources are to be reserved
2759  *	@res_name: Name to be associated with resource.
2760  *
2761  *	Mark all PCI regions associated with PCI device @pdev as
2762  *	being reserved by owner @res_name.  Do not access any
2763  *	address inside the PCI regions unless this call returns
2764  *	successfully.
2765  *
2766  *	Returns 0 on success, or %EBUSY on error.  A warning
2767  *	message is also printed on failure.
2768  */
2769 int pci_request_regions(struct pci_dev *pdev, const char *res_name)
2770 {
2771 	return pci_request_selected_regions(pdev, ((1 << 6) - 1), res_name);
2772 }
2773 
2774 /**
2775  *	pci_request_regions_exclusive - Reserved PCI I/O and memory resources
2776  *	@pdev: PCI device whose resources are to be reserved
2777  *	@res_name: Name to be associated with resource.
2778  *
2779  *	Mark all PCI regions associated with PCI device @pdev as
2780  *	being reserved by owner @res_name.  Do not access any
2781  *	address inside the PCI regions unless this call returns
2782  *	successfully.
2783  *
2784  *	pci_request_regions_exclusive() will mark the region so that
2785  * 	/dev/mem and the sysfs MMIO access will not be allowed.
2786  *
2787  *	Returns 0 on success, or %EBUSY on error.  A warning
2788  *	message is also printed on failure.
2789  */
2790 int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name)
2791 {
2792 	return pci_request_selected_regions_exclusive(pdev,
2793 					((1 << 6) - 1), res_name);
2794 }
2795 
2796 static void __pci_set_master(struct pci_dev *dev, bool enable)
2797 {
2798 	u16 old_cmd, cmd;
2799 
2800 	pci_read_config_word(dev, PCI_COMMAND, &old_cmd);
2801 	if (enable)
2802 		cmd = old_cmd | PCI_COMMAND_MASTER;
2803 	else
2804 		cmd = old_cmd & ~PCI_COMMAND_MASTER;
2805 	if (cmd != old_cmd) {
2806 		dev_dbg(&dev->dev, "%s bus mastering\n",
2807 			enable ? "enabling" : "disabling");
2808 		pci_write_config_word(dev, PCI_COMMAND, cmd);
2809 	}
2810 	dev->is_busmaster = enable;
2811 }
2812 
2813 /**
2814  * pcibios_setup - process "pci=" kernel boot arguments
2815  * @str: string used to pass in "pci=" kernel boot arguments
2816  *
2817  * Process kernel boot arguments.  This is the default implementation.
2818  * Architecture specific implementations can override this as necessary.
2819  */
2820 char * __weak __init pcibios_setup(char *str)
2821 {
2822 	return str;
2823 }
2824 
2825 /**
2826  * pcibios_set_master - enable PCI bus-mastering for device dev
2827  * @dev: the PCI device to enable
2828  *
2829  * Enables PCI bus-mastering for the device.  This is the default
2830  * implementation.  Architecture specific implementations can override
2831  * this if necessary.
2832  */
2833 void __weak pcibios_set_master(struct pci_dev *dev)
2834 {
2835 	u8 lat;
2836 
2837 	/* The latency timer doesn't apply to PCIe (either Type 0 or Type 1) */
2838 	if (pci_is_pcie(dev))
2839 		return;
2840 
2841 	pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat);
2842 	if (lat < 16)
2843 		lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency;
2844 	else if (lat > pcibios_max_latency)
2845 		lat = pcibios_max_latency;
2846 	else
2847 		return;
2848 	dev_printk(KERN_DEBUG, &dev->dev, "setting latency timer to %d\n", lat);
2849 	pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat);
2850 }
2851 
2852 /**
2853  * pci_set_master - enables bus-mastering for device dev
2854  * @dev: the PCI device to enable
2855  *
2856  * Enables bus-mastering on the device and calls pcibios_set_master()
2857  * to do the needed arch specific settings.
2858  */
2859 void pci_set_master(struct pci_dev *dev)
2860 {
2861 	__pci_set_master(dev, true);
2862 	pcibios_set_master(dev);
2863 }
2864 
2865 /**
2866  * pci_clear_master - disables bus-mastering for device dev
2867  * @dev: the PCI device to disable
2868  */
2869 void pci_clear_master(struct pci_dev *dev)
2870 {
2871 	__pci_set_master(dev, false);
2872 }
2873 
2874 /**
2875  * pci_set_cacheline_size - ensure the CACHE_LINE_SIZE register is programmed
2876  * @dev: the PCI device for which MWI is to be enabled
2877  *
2878  * Helper function for pci_set_mwi.
2879  * Originally copied from drivers/net/acenic.c.
2880  * Copyright 1998-2001 by Jes Sorensen, <jes@trained-monkey.org>.
2881  *
2882  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2883  */
2884 int pci_set_cacheline_size(struct pci_dev *dev)
2885 {
2886 	u8 cacheline_size;
2887 
2888 	if (!pci_cache_line_size)
2889 		return -EINVAL;
2890 
2891 	/* Validate current setting: the PCI_CACHE_LINE_SIZE must be
2892 	   equal to or multiple of the right value. */
2893 	pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
2894 	if (cacheline_size >= pci_cache_line_size &&
2895 	    (cacheline_size % pci_cache_line_size) == 0)
2896 		return 0;
2897 
2898 	/* Write the correct value. */
2899 	pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, pci_cache_line_size);
2900 	/* Read it back. */
2901 	pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
2902 	if (cacheline_size == pci_cache_line_size)
2903 		return 0;
2904 
2905 	dev_printk(KERN_DEBUG, &dev->dev, "cache line size of %d is not "
2906 		   "supported\n", pci_cache_line_size << 2);
2907 
2908 	return -EINVAL;
2909 }
2910 EXPORT_SYMBOL_GPL(pci_set_cacheline_size);
2911 
2912 #ifdef PCI_DISABLE_MWI
2913 int pci_set_mwi(struct pci_dev *dev)
2914 {
2915 	return 0;
2916 }
2917 
2918 int pci_try_set_mwi(struct pci_dev *dev)
2919 {
2920 	return 0;
2921 }
2922 
2923 void pci_clear_mwi(struct pci_dev *dev)
2924 {
2925 }
2926 
2927 #else
2928 
2929 /**
2930  * pci_set_mwi - enables memory-write-invalidate PCI transaction
2931  * @dev: the PCI device for which MWI is enabled
2932  *
2933  * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND.
2934  *
2935  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2936  */
2937 int
2938 pci_set_mwi(struct pci_dev *dev)
2939 {
2940 	int rc;
2941 	u16 cmd;
2942 
2943 	rc = pci_set_cacheline_size(dev);
2944 	if (rc)
2945 		return rc;
2946 
2947 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
2948 	if (! (cmd & PCI_COMMAND_INVALIDATE)) {
2949 		dev_dbg(&dev->dev, "enabling Mem-Wr-Inval\n");
2950 		cmd |= PCI_COMMAND_INVALIDATE;
2951 		pci_write_config_word(dev, PCI_COMMAND, cmd);
2952 	}
2953 
2954 	return 0;
2955 }
2956 
2957 /**
2958  * pci_try_set_mwi - enables memory-write-invalidate PCI transaction
2959  * @dev: the PCI device for which MWI is enabled
2960  *
2961  * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND.
2962  * Callers are not required to check the return value.
2963  *
2964  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2965  */
2966 int pci_try_set_mwi(struct pci_dev *dev)
2967 {
2968 	int rc = pci_set_mwi(dev);
2969 	return rc;
2970 }
2971 
2972 /**
2973  * pci_clear_mwi - disables Memory-Write-Invalidate for device dev
2974  * @dev: the PCI device to disable
2975  *
2976  * Disables PCI Memory-Write-Invalidate transaction on the device
2977  */
2978 void
2979 pci_clear_mwi(struct pci_dev *dev)
2980 {
2981 	u16 cmd;
2982 
2983 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
2984 	if (cmd & PCI_COMMAND_INVALIDATE) {
2985 		cmd &= ~PCI_COMMAND_INVALIDATE;
2986 		pci_write_config_word(dev, PCI_COMMAND, cmd);
2987 	}
2988 }
2989 #endif /* ! PCI_DISABLE_MWI */
2990 
2991 /**
2992  * pci_intx - enables/disables PCI INTx for device dev
2993  * @pdev: the PCI device to operate on
2994  * @enable: boolean: whether to enable or disable PCI INTx
2995  *
2996  * Enables/disables PCI INTx for device dev
2997  */
2998 void
2999 pci_intx(struct pci_dev *pdev, int enable)
3000 {
3001 	u16 pci_command, new;
3002 
3003 	pci_read_config_word(pdev, PCI_COMMAND, &pci_command);
3004 
3005 	if (enable) {
3006 		new = pci_command & ~PCI_COMMAND_INTX_DISABLE;
3007 	} else {
3008 		new = pci_command | PCI_COMMAND_INTX_DISABLE;
3009 	}
3010 
3011 	if (new != pci_command) {
3012 		struct pci_devres *dr;
3013 
3014 		pci_write_config_word(pdev, PCI_COMMAND, new);
3015 
3016 		dr = find_pci_dr(pdev);
3017 		if (dr && !dr->restore_intx) {
3018 			dr->restore_intx = 1;
3019 			dr->orig_intx = !enable;
3020 		}
3021 	}
3022 }
3023 
3024 /**
3025  * pci_intx_mask_supported - probe for INTx masking support
3026  * @dev: the PCI device to operate on
3027  *
3028  * Check if the device dev support INTx masking via the config space
3029  * command word.
3030  */
3031 bool pci_intx_mask_supported(struct pci_dev *dev)
3032 {
3033 	bool mask_supported = false;
3034 	u16 orig, new;
3035 
3036 	if (dev->broken_intx_masking)
3037 		return false;
3038 
3039 	pci_cfg_access_lock(dev);
3040 
3041 	pci_read_config_word(dev, PCI_COMMAND, &orig);
3042 	pci_write_config_word(dev, PCI_COMMAND,
3043 			      orig ^ PCI_COMMAND_INTX_DISABLE);
3044 	pci_read_config_word(dev, PCI_COMMAND, &new);
3045 
3046 	/*
3047 	 * There's no way to protect against hardware bugs or detect them
3048 	 * reliably, but as long as we know what the value should be, let's
3049 	 * go ahead and check it.
3050 	 */
3051 	if ((new ^ orig) & ~PCI_COMMAND_INTX_DISABLE) {
3052 		dev_err(&dev->dev, "Command register changed from "
3053 			"0x%x to 0x%x: driver or hardware bug?\n", orig, new);
3054 	} else if ((new ^ orig) & PCI_COMMAND_INTX_DISABLE) {
3055 		mask_supported = true;
3056 		pci_write_config_word(dev, PCI_COMMAND, orig);
3057 	}
3058 
3059 	pci_cfg_access_unlock(dev);
3060 	return mask_supported;
3061 }
3062 EXPORT_SYMBOL_GPL(pci_intx_mask_supported);
3063 
3064 static bool pci_check_and_set_intx_mask(struct pci_dev *dev, bool mask)
3065 {
3066 	struct pci_bus *bus = dev->bus;
3067 	bool mask_updated = true;
3068 	u32 cmd_status_dword;
3069 	u16 origcmd, newcmd;
3070 	unsigned long flags;
3071 	bool irq_pending;
3072 
3073 	/*
3074 	 * We do a single dword read to retrieve both command and status.
3075 	 * Document assumptions that make this possible.
3076 	 */
3077 	BUILD_BUG_ON(PCI_COMMAND % 4);
3078 	BUILD_BUG_ON(PCI_COMMAND + 2 != PCI_STATUS);
3079 
3080 	raw_spin_lock_irqsave(&pci_lock, flags);
3081 
3082 	bus->ops->read(bus, dev->devfn, PCI_COMMAND, 4, &cmd_status_dword);
3083 
3084 	irq_pending = (cmd_status_dword >> 16) & PCI_STATUS_INTERRUPT;
3085 
3086 	/*
3087 	 * Check interrupt status register to see whether our device
3088 	 * triggered the interrupt (when masking) or the next IRQ is
3089 	 * already pending (when unmasking).
3090 	 */
3091 	if (mask != irq_pending) {
3092 		mask_updated = false;
3093 		goto done;
3094 	}
3095 
3096 	origcmd = cmd_status_dword;
3097 	newcmd = origcmd & ~PCI_COMMAND_INTX_DISABLE;
3098 	if (mask)
3099 		newcmd |= PCI_COMMAND_INTX_DISABLE;
3100 	if (newcmd != origcmd)
3101 		bus->ops->write(bus, dev->devfn, PCI_COMMAND, 2, newcmd);
3102 
3103 done:
3104 	raw_spin_unlock_irqrestore(&pci_lock, flags);
3105 
3106 	return mask_updated;
3107 }
3108 
3109 /**
3110  * pci_check_and_mask_intx - mask INTx on pending interrupt
3111  * @dev: the PCI device to operate on
3112  *
3113  * Check if the device dev has its INTx line asserted, mask it and
3114  * return true in that case. False is returned if not interrupt was
3115  * pending.
3116  */
3117 bool pci_check_and_mask_intx(struct pci_dev *dev)
3118 {
3119 	return pci_check_and_set_intx_mask(dev, true);
3120 }
3121 EXPORT_SYMBOL_GPL(pci_check_and_mask_intx);
3122 
3123 /**
3124  * pci_check_and_mask_intx - unmask INTx of no interrupt is pending
3125  * @dev: the PCI device to operate on
3126  *
3127  * Check if the device dev has its INTx line asserted, unmask it if not
3128  * and return true. False is returned and the mask remains active if
3129  * there was still an interrupt pending.
3130  */
3131 bool pci_check_and_unmask_intx(struct pci_dev *dev)
3132 {
3133 	return pci_check_and_set_intx_mask(dev, false);
3134 }
3135 EXPORT_SYMBOL_GPL(pci_check_and_unmask_intx);
3136 
3137 /**
3138  * pci_msi_off - disables any msi or msix capabilities
3139  * @dev: the PCI device to operate on
3140  *
3141  * If you want to use msi see pci_enable_msi and friends.
3142  * This is a lower level primitive that allows us to disable
3143  * msi operation at the device level.
3144  */
3145 void pci_msi_off(struct pci_dev *dev)
3146 {
3147 	int pos;
3148 	u16 control;
3149 
3150 	pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
3151 	if (pos) {
3152 		pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control);
3153 		control &= ~PCI_MSI_FLAGS_ENABLE;
3154 		pci_write_config_word(dev, pos + PCI_MSI_FLAGS, control);
3155 	}
3156 	pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
3157 	if (pos) {
3158 		pci_read_config_word(dev, pos + PCI_MSIX_FLAGS, &control);
3159 		control &= ~PCI_MSIX_FLAGS_ENABLE;
3160 		pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control);
3161 	}
3162 }
3163 EXPORT_SYMBOL_GPL(pci_msi_off);
3164 
3165 int pci_set_dma_max_seg_size(struct pci_dev *dev, unsigned int size)
3166 {
3167 	return dma_set_max_seg_size(&dev->dev, size);
3168 }
3169 EXPORT_SYMBOL(pci_set_dma_max_seg_size);
3170 
3171 int pci_set_dma_seg_boundary(struct pci_dev *dev, unsigned long mask)
3172 {
3173 	return dma_set_seg_boundary(&dev->dev, mask);
3174 }
3175 EXPORT_SYMBOL(pci_set_dma_seg_boundary);
3176 
3177 static int pcie_flr(struct pci_dev *dev, int probe)
3178 {
3179 	int i;
3180 	int pos;
3181 	u32 cap;
3182 	u16 status, control;
3183 
3184 	pos = pci_pcie_cap(dev);
3185 	if (!pos)
3186 		return -ENOTTY;
3187 
3188 	pci_read_config_dword(dev, pos + PCI_EXP_DEVCAP, &cap);
3189 	if (!(cap & PCI_EXP_DEVCAP_FLR))
3190 		return -ENOTTY;
3191 
3192 	if (probe)
3193 		return 0;
3194 
3195 	/* Wait for Transaction Pending bit clean */
3196 	for (i = 0; i < 4; i++) {
3197 		if (i)
3198 			msleep((1 << (i - 1)) * 100);
3199 
3200 		pci_read_config_word(dev, pos + PCI_EXP_DEVSTA, &status);
3201 		if (!(status & PCI_EXP_DEVSTA_TRPND))
3202 			goto clear;
3203 	}
3204 
3205 	dev_err(&dev->dev, "transaction is not cleared; "
3206 			"proceeding with reset anyway\n");
3207 
3208 clear:
3209 	pci_read_config_word(dev, pos + PCI_EXP_DEVCTL, &control);
3210 	control |= PCI_EXP_DEVCTL_BCR_FLR;
3211 	pci_write_config_word(dev, pos + PCI_EXP_DEVCTL, control);
3212 
3213 	msleep(100);
3214 
3215 	return 0;
3216 }
3217 
3218 static int pci_af_flr(struct pci_dev *dev, int probe)
3219 {
3220 	int i;
3221 	int pos;
3222 	u8 cap;
3223 	u8 status;
3224 
3225 	pos = pci_find_capability(dev, PCI_CAP_ID_AF);
3226 	if (!pos)
3227 		return -ENOTTY;
3228 
3229 	pci_read_config_byte(dev, pos + PCI_AF_CAP, &cap);
3230 	if (!(cap & PCI_AF_CAP_TP) || !(cap & PCI_AF_CAP_FLR))
3231 		return -ENOTTY;
3232 
3233 	if (probe)
3234 		return 0;
3235 
3236 	/* Wait for Transaction Pending bit clean */
3237 	for (i = 0; i < 4; i++) {
3238 		if (i)
3239 			msleep((1 << (i - 1)) * 100);
3240 
3241 		pci_read_config_byte(dev, pos + PCI_AF_STATUS, &status);
3242 		if (!(status & PCI_AF_STATUS_TP))
3243 			goto clear;
3244 	}
3245 
3246 	dev_err(&dev->dev, "transaction is not cleared; "
3247 			"proceeding with reset anyway\n");
3248 
3249 clear:
3250 	pci_write_config_byte(dev, pos + PCI_AF_CTRL, PCI_AF_CTRL_FLR);
3251 	msleep(100);
3252 
3253 	return 0;
3254 }
3255 
3256 /**
3257  * pci_pm_reset - Put device into PCI_D3 and back into PCI_D0.
3258  * @dev: Device to reset.
3259  * @probe: If set, only check if the device can be reset this way.
3260  *
3261  * If @dev supports native PCI PM and its PCI_PM_CTRL_NO_SOFT_RESET flag is
3262  * unset, it will be reinitialized internally when going from PCI_D3hot to
3263  * PCI_D0.  If that's the case and the device is not in a low-power state
3264  * already, force it into PCI_D3hot and back to PCI_D0, causing it to be reset.
3265  *
3266  * NOTE: This causes the caller to sleep for twice the device power transition
3267  * cooldown period, which for the D0->D3hot and D3hot->D0 transitions is 10 ms
3268  * by devault (i.e. unless the @dev's d3_delay field has a different value).
3269  * Moreover, only devices in D0 can be reset by this function.
3270  */
3271 static int pci_pm_reset(struct pci_dev *dev, int probe)
3272 {
3273 	u16 csr;
3274 
3275 	if (!dev->pm_cap)
3276 		return -ENOTTY;
3277 
3278 	pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &csr);
3279 	if (csr & PCI_PM_CTRL_NO_SOFT_RESET)
3280 		return -ENOTTY;
3281 
3282 	if (probe)
3283 		return 0;
3284 
3285 	if (dev->current_state != PCI_D0)
3286 		return -EINVAL;
3287 
3288 	csr &= ~PCI_PM_CTRL_STATE_MASK;
3289 	csr |= PCI_D3hot;
3290 	pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);
3291 	pci_dev_d3_sleep(dev);
3292 
3293 	csr &= ~PCI_PM_CTRL_STATE_MASK;
3294 	csr |= PCI_D0;
3295 	pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);
3296 	pci_dev_d3_sleep(dev);
3297 
3298 	return 0;
3299 }
3300 
3301 static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
3302 {
3303 	u16 ctrl;
3304 	struct pci_dev *pdev;
3305 
3306 	if (pci_is_root_bus(dev->bus) || dev->subordinate || !dev->bus->self)
3307 		return -ENOTTY;
3308 
3309 	list_for_each_entry(pdev, &dev->bus->devices, bus_list)
3310 		if (pdev != dev)
3311 			return -ENOTTY;
3312 
3313 	if (probe)
3314 		return 0;
3315 
3316 	pci_read_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, &ctrl);
3317 	ctrl |= PCI_BRIDGE_CTL_BUS_RESET;
3318 	pci_write_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, ctrl);
3319 	msleep(100);
3320 
3321 	ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET;
3322 	pci_write_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, ctrl);
3323 	msleep(100);
3324 
3325 	return 0;
3326 }
3327 
3328 static int __pci_dev_reset(struct pci_dev *dev, int probe)
3329 {
3330 	int rc;
3331 
3332 	might_sleep();
3333 
3334 	rc = pci_dev_specific_reset(dev, probe);
3335 	if (rc != -ENOTTY)
3336 		goto done;
3337 
3338 	rc = pcie_flr(dev, probe);
3339 	if (rc != -ENOTTY)
3340 		goto done;
3341 
3342 	rc = pci_af_flr(dev, probe);
3343 	if (rc != -ENOTTY)
3344 		goto done;
3345 
3346 	rc = pci_pm_reset(dev, probe);
3347 	if (rc != -ENOTTY)
3348 		goto done;
3349 
3350 	rc = pci_parent_bus_reset(dev, probe);
3351 done:
3352 	return rc;
3353 }
3354 
3355 static int pci_dev_reset(struct pci_dev *dev, int probe)
3356 {
3357 	int rc;
3358 
3359 	if (!probe) {
3360 		pci_cfg_access_lock(dev);
3361 		/* block PM suspend, driver probe, etc. */
3362 		device_lock(&dev->dev);
3363 	}
3364 
3365 	rc = __pci_dev_reset(dev, probe);
3366 
3367 	if (!probe) {
3368 		device_unlock(&dev->dev);
3369 		pci_cfg_access_unlock(dev);
3370 	}
3371 	return rc;
3372 }
3373 /**
3374  * __pci_reset_function - reset a PCI device function
3375  * @dev: PCI device to reset
3376  *
3377  * Some devices allow an individual function to be reset without affecting
3378  * other functions in the same device.  The PCI device must be responsive
3379  * to PCI config space in order to use this function.
3380  *
3381  * The device function is presumed to be unused when this function is called.
3382  * Resetting the device will make the contents of PCI configuration space
3383  * random, so any caller of this must be prepared to reinitialise the
3384  * device including MSI, bus mastering, BARs, decoding IO and memory spaces,
3385  * etc.
3386  *
3387  * Returns 0 if the device function was successfully reset or negative if the
3388  * device doesn't support resetting a single function.
3389  */
3390 int __pci_reset_function(struct pci_dev *dev)
3391 {
3392 	return pci_dev_reset(dev, 0);
3393 }
3394 EXPORT_SYMBOL_GPL(__pci_reset_function);
3395 
3396 /**
3397  * __pci_reset_function_locked - reset a PCI device function while holding
3398  * the @dev mutex lock.
3399  * @dev: PCI device to reset
3400  *
3401  * Some devices allow an individual function to be reset without affecting
3402  * other functions in the same device.  The PCI device must be responsive
3403  * to PCI config space in order to use this function.
3404  *
3405  * The device function is presumed to be unused and the caller is holding
3406  * the device mutex lock when this function is called.
3407  * Resetting the device will make the contents of PCI configuration space
3408  * random, so any caller of this must be prepared to reinitialise the
3409  * device including MSI, bus mastering, BARs, decoding IO and memory spaces,
3410  * etc.
3411  *
3412  * Returns 0 if the device function was successfully reset or negative if the
3413  * device doesn't support resetting a single function.
3414  */
3415 int __pci_reset_function_locked(struct pci_dev *dev)
3416 {
3417 	return __pci_dev_reset(dev, 0);
3418 }
3419 EXPORT_SYMBOL_GPL(__pci_reset_function_locked);
3420 
3421 /**
3422  * pci_probe_reset_function - check whether the device can be safely reset
3423  * @dev: PCI device to reset
3424  *
3425  * Some devices allow an individual function to be reset without affecting
3426  * other functions in the same device.  The PCI device must be responsive
3427  * to PCI config space in order to use this function.
3428  *
3429  * Returns 0 if the device function can be reset or negative if the
3430  * device doesn't support resetting a single function.
3431  */
3432 int pci_probe_reset_function(struct pci_dev *dev)
3433 {
3434 	return pci_dev_reset(dev, 1);
3435 }
3436 
3437 /**
3438  * pci_reset_function - quiesce and reset a PCI device function
3439  * @dev: PCI device to reset
3440  *
3441  * Some devices allow an individual function to be reset without affecting
3442  * other functions in the same device.  The PCI device must be responsive
3443  * to PCI config space in order to use this function.
3444  *
3445  * This function does not just reset the PCI portion of a device, but
3446  * clears all the state associated with the device.  This function differs
3447  * from __pci_reset_function in that it saves and restores device state
3448  * over the reset.
3449  *
3450  * Returns 0 if the device function was successfully reset or negative if the
3451  * device doesn't support resetting a single function.
3452  */
3453 int pci_reset_function(struct pci_dev *dev)
3454 {
3455 	int rc;
3456 
3457 	rc = pci_dev_reset(dev, 1);
3458 	if (rc)
3459 		return rc;
3460 
3461 	pci_save_state(dev);
3462 
3463 	/*
3464 	 * both INTx and MSI are disabled after the Interrupt Disable bit
3465 	 * is set and the Bus Master bit is cleared.
3466 	 */
3467 	pci_write_config_word(dev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
3468 
3469 	rc = pci_dev_reset(dev, 0);
3470 
3471 	pci_restore_state(dev);
3472 
3473 	return rc;
3474 }
3475 EXPORT_SYMBOL_GPL(pci_reset_function);
3476 
3477 /**
3478  * pcix_get_max_mmrbc - get PCI-X maximum designed memory read byte count
3479  * @dev: PCI device to query
3480  *
3481  * Returns mmrbc: maximum designed memory read count in bytes
3482  *    or appropriate error value.
3483  */
3484 int pcix_get_max_mmrbc(struct pci_dev *dev)
3485 {
3486 	int cap;
3487 	u32 stat;
3488 
3489 	cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
3490 	if (!cap)
3491 		return -EINVAL;
3492 
3493 	if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat))
3494 		return -EINVAL;
3495 
3496 	return 512 << ((stat & PCI_X_STATUS_MAX_READ) >> 21);
3497 }
3498 EXPORT_SYMBOL(pcix_get_max_mmrbc);
3499 
3500 /**
3501  * pcix_get_mmrbc - get PCI-X maximum memory read byte count
3502  * @dev: PCI device to query
3503  *
3504  * Returns mmrbc: maximum memory read count in bytes
3505  *    or appropriate error value.
3506  */
3507 int pcix_get_mmrbc(struct pci_dev *dev)
3508 {
3509 	int cap;
3510 	u16 cmd;
3511 
3512 	cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
3513 	if (!cap)
3514 		return -EINVAL;
3515 
3516 	if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd))
3517 		return -EINVAL;
3518 
3519 	return 512 << ((cmd & PCI_X_CMD_MAX_READ) >> 2);
3520 }
3521 EXPORT_SYMBOL(pcix_get_mmrbc);
3522 
3523 /**
3524  * pcix_set_mmrbc - set PCI-X maximum memory read byte count
3525  * @dev: PCI device to query
3526  * @mmrbc: maximum memory read count in bytes
3527  *    valid values are 512, 1024, 2048, 4096
3528  *
3529  * If possible sets maximum memory read byte count, some bridges have erratas
3530  * that prevent this.
3531  */
3532 int pcix_set_mmrbc(struct pci_dev *dev, int mmrbc)
3533 {
3534 	int cap;
3535 	u32 stat, v, o;
3536 	u16 cmd;
3537 
3538 	if (mmrbc < 512 || mmrbc > 4096 || !is_power_of_2(mmrbc))
3539 		return -EINVAL;
3540 
3541 	v = ffs(mmrbc) - 10;
3542 
3543 	cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
3544 	if (!cap)
3545 		return -EINVAL;
3546 
3547 	if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat))
3548 		return -EINVAL;
3549 
3550 	if (v > (stat & PCI_X_STATUS_MAX_READ) >> 21)
3551 		return -E2BIG;
3552 
3553 	if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd))
3554 		return -EINVAL;
3555 
3556 	o = (cmd & PCI_X_CMD_MAX_READ) >> 2;
3557 	if (o != v) {
3558 		if (v > o && (dev->bus->bus_flags & PCI_BUS_FLAGS_NO_MMRBC))
3559 			return -EIO;
3560 
3561 		cmd &= ~PCI_X_CMD_MAX_READ;
3562 		cmd |= v << 2;
3563 		if (pci_write_config_word(dev, cap + PCI_X_CMD, cmd))
3564 			return -EIO;
3565 	}
3566 	return 0;
3567 }
3568 EXPORT_SYMBOL(pcix_set_mmrbc);
3569 
3570 /**
3571  * pcie_get_readrq - get PCI Express read request size
3572  * @dev: PCI device to query
3573  *
3574  * Returns maximum memory read request in bytes
3575  *    or appropriate error value.
3576  */
3577 int pcie_get_readrq(struct pci_dev *dev)
3578 {
3579 	int ret, cap;
3580 	u16 ctl;
3581 
3582 	cap = pci_pcie_cap(dev);
3583 	if (!cap)
3584 		return -EINVAL;
3585 
3586 	ret = pci_read_config_word(dev, cap + PCI_EXP_DEVCTL, &ctl);
3587 	if (!ret)
3588 		ret = 128 << ((ctl & PCI_EXP_DEVCTL_READRQ) >> 12);
3589 
3590 	return ret;
3591 }
3592 EXPORT_SYMBOL(pcie_get_readrq);
3593 
3594 /**
3595  * pcie_set_readrq - set PCI Express maximum memory read request
3596  * @dev: PCI device to query
3597  * @rq: maximum memory read count in bytes
3598  *    valid values are 128, 256, 512, 1024, 2048, 4096
3599  *
3600  * If possible sets maximum memory read request in bytes
3601  */
3602 int pcie_set_readrq(struct pci_dev *dev, int rq)
3603 {
3604 	int cap, err = -EINVAL;
3605 	u16 ctl, v;
3606 
3607 	if (rq < 128 || rq > 4096 || !is_power_of_2(rq))
3608 		goto out;
3609 
3610 	cap = pci_pcie_cap(dev);
3611 	if (!cap)
3612 		goto out;
3613 
3614 	err = pci_read_config_word(dev, cap + PCI_EXP_DEVCTL, &ctl);
3615 	if (err)
3616 		goto out;
3617 	/*
3618 	 * If using the "performance" PCIe config, we clamp the
3619 	 * read rq size to the max packet size to prevent the
3620 	 * host bridge generating requests larger than we can
3621 	 * cope with
3622 	 */
3623 	if (pcie_bus_config == PCIE_BUS_PERFORMANCE) {
3624 		int mps = pcie_get_mps(dev);
3625 
3626 		if (mps < 0)
3627 			return mps;
3628 		if (mps < rq)
3629 			rq = mps;
3630 	}
3631 
3632 	v = (ffs(rq) - 8) << 12;
3633 
3634 	if ((ctl & PCI_EXP_DEVCTL_READRQ) != v) {
3635 		ctl &= ~PCI_EXP_DEVCTL_READRQ;
3636 		ctl |= v;
3637 		err = pci_write_config_word(dev, cap + PCI_EXP_DEVCTL, ctl);
3638 	}
3639 
3640 out:
3641 	return err;
3642 }
3643 EXPORT_SYMBOL(pcie_set_readrq);
3644 
3645 /**
3646  * pcie_get_mps - get PCI Express maximum payload size
3647  * @dev: PCI device to query
3648  *
3649  * Returns maximum payload size in bytes
3650  *    or appropriate error value.
3651  */
3652 int pcie_get_mps(struct pci_dev *dev)
3653 {
3654 	int ret, cap;
3655 	u16 ctl;
3656 
3657 	cap = pci_pcie_cap(dev);
3658 	if (!cap)
3659 		return -EINVAL;
3660 
3661 	ret = pci_read_config_word(dev, cap + PCI_EXP_DEVCTL, &ctl);
3662 	if (!ret)
3663 		ret = 128 << ((ctl & PCI_EXP_DEVCTL_PAYLOAD) >> 5);
3664 
3665 	return ret;
3666 }
3667 
3668 /**
3669  * pcie_set_mps - set PCI Express maximum payload size
3670  * @dev: PCI device to query
3671  * @mps: maximum payload size in bytes
3672  *    valid values are 128, 256, 512, 1024, 2048, 4096
3673  *
3674  * If possible sets maximum payload size
3675  */
3676 int pcie_set_mps(struct pci_dev *dev, int mps)
3677 {
3678 	int cap, err = -EINVAL;
3679 	u16 ctl, v;
3680 
3681 	if (mps < 128 || mps > 4096 || !is_power_of_2(mps))
3682 		goto out;
3683 
3684 	v = ffs(mps) - 8;
3685 	if (v > dev->pcie_mpss)
3686 		goto out;
3687 	v <<= 5;
3688 
3689 	cap = pci_pcie_cap(dev);
3690 	if (!cap)
3691 		goto out;
3692 
3693 	err = pci_read_config_word(dev, cap + PCI_EXP_DEVCTL, &ctl);
3694 	if (err)
3695 		goto out;
3696 
3697 	if ((ctl & PCI_EXP_DEVCTL_PAYLOAD) != v) {
3698 		ctl &= ~PCI_EXP_DEVCTL_PAYLOAD;
3699 		ctl |= v;
3700 		err = pci_write_config_word(dev, cap + PCI_EXP_DEVCTL, ctl);
3701 	}
3702 out:
3703 	return err;
3704 }
3705 
3706 /**
3707  * pci_select_bars - Make BAR mask from the type of resource
3708  * @dev: the PCI device for which BAR mask is made
3709  * @flags: resource type mask to be selected
3710  *
3711  * This helper routine makes bar mask from the type of resource.
3712  */
3713 int pci_select_bars(struct pci_dev *dev, unsigned long flags)
3714 {
3715 	int i, bars = 0;
3716 	for (i = 0; i < PCI_NUM_RESOURCES; i++)
3717 		if (pci_resource_flags(dev, i) & flags)
3718 			bars |= (1 << i);
3719 	return bars;
3720 }
3721 
3722 /**
3723  * pci_resource_bar - get position of the BAR associated with a resource
3724  * @dev: the PCI device
3725  * @resno: the resource number
3726  * @type: the BAR type to be filled in
3727  *
3728  * Returns BAR position in config space, or 0 if the BAR is invalid.
3729  */
3730 int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type)
3731 {
3732 	int reg;
3733 
3734 	if (resno < PCI_ROM_RESOURCE) {
3735 		*type = pci_bar_unknown;
3736 		return PCI_BASE_ADDRESS_0 + 4 * resno;
3737 	} else if (resno == PCI_ROM_RESOURCE) {
3738 		*type = pci_bar_mem32;
3739 		return dev->rom_base_reg;
3740 	} else if (resno < PCI_BRIDGE_RESOURCES) {
3741 		/* device specific resource */
3742 		reg = pci_iov_resource_bar(dev, resno, type);
3743 		if (reg)
3744 			return reg;
3745 	}
3746 
3747 	dev_err(&dev->dev, "BAR %d: invalid resource\n", resno);
3748 	return 0;
3749 }
3750 
3751 /* Some architectures require additional programming to enable VGA */
3752 static arch_set_vga_state_t arch_set_vga_state;
3753 
3754 void __init pci_register_set_vga_state(arch_set_vga_state_t func)
3755 {
3756 	arch_set_vga_state = func;	/* NULL disables */
3757 }
3758 
3759 static int pci_set_vga_state_arch(struct pci_dev *dev, bool decode,
3760 		      unsigned int command_bits, u32 flags)
3761 {
3762 	if (arch_set_vga_state)
3763 		return arch_set_vga_state(dev, decode, command_bits,
3764 						flags);
3765 	return 0;
3766 }
3767 
3768 /**
3769  * pci_set_vga_state - set VGA decode state on device and parents if requested
3770  * @dev: the PCI device
3771  * @decode: true = enable decoding, false = disable decoding
3772  * @command_bits: PCI_COMMAND_IO and/or PCI_COMMAND_MEMORY
3773  * @flags: traverse ancestors and change bridges
3774  * CHANGE_BRIDGE_ONLY / CHANGE_BRIDGE
3775  */
3776 int pci_set_vga_state(struct pci_dev *dev, bool decode,
3777 		      unsigned int command_bits, u32 flags)
3778 {
3779 	struct pci_bus *bus;
3780 	struct pci_dev *bridge;
3781 	u16 cmd;
3782 	int rc;
3783 
3784 	WARN_ON((flags & PCI_VGA_STATE_CHANGE_DECODES) & (command_bits & ~(PCI_COMMAND_IO|PCI_COMMAND_MEMORY)));
3785 
3786 	/* ARCH specific VGA enables */
3787 	rc = pci_set_vga_state_arch(dev, decode, command_bits, flags);
3788 	if (rc)
3789 		return rc;
3790 
3791 	if (flags & PCI_VGA_STATE_CHANGE_DECODES) {
3792 		pci_read_config_word(dev, PCI_COMMAND, &cmd);
3793 		if (decode == true)
3794 			cmd |= command_bits;
3795 		else
3796 			cmd &= ~command_bits;
3797 		pci_write_config_word(dev, PCI_COMMAND, cmd);
3798 	}
3799 
3800 	if (!(flags & PCI_VGA_STATE_CHANGE_BRIDGE))
3801 		return 0;
3802 
3803 	bus = dev->bus;
3804 	while (bus) {
3805 		bridge = bus->self;
3806 		if (bridge) {
3807 			pci_read_config_word(bridge, PCI_BRIDGE_CONTROL,
3808 					     &cmd);
3809 			if (decode == true)
3810 				cmd |= PCI_BRIDGE_CTL_VGA;
3811 			else
3812 				cmd &= ~PCI_BRIDGE_CTL_VGA;
3813 			pci_write_config_word(bridge, PCI_BRIDGE_CONTROL,
3814 					      cmd);
3815 		}
3816 		bus = bus->parent;
3817 	}
3818 	return 0;
3819 }
3820 
3821 #define RESOURCE_ALIGNMENT_PARAM_SIZE COMMAND_LINE_SIZE
3822 static char resource_alignment_param[RESOURCE_ALIGNMENT_PARAM_SIZE] = {0};
3823 static DEFINE_SPINLOCK(resource_alignment_lock);
3824 
3825 /**
3826  * pci_specified_resource_alignment - get resource alignment specified by user.
3827  * @dev: the PCI device to get
3828  *
3829  * RETURNS: Resource alignment if it is specified.
3830  *          Zero if it is not specified.
3831  */
3832 resource_size_t pci_specified_resource_alignment(struct pci_dev *dev)
3833 {
3834 	int seg, bus, slot, func, align_order, count;
3835 	resource_size_t align = 0;
3836 	char *p;
3837 
3838 	spin_lock(&resource_alignment_lock);
3839 	p = resource_alignment_param;
3840 	while (*p) {
3841 		count = 0;
3842 		if (sscanf(p, "%d%n", &align_order, &count) == 1 &&
3843 							p[count] == '@') {
3844 			p += count + 1;
3845 		} else {
3846 			align_order = -1;
3847 		}
3848 		if (sscanf(p, "%x:%x:%x.%x%n",
3849 			&seg, &bus, &slot, &func, &count) != 4) {
3850 			seg = 0;
3851 			if (sscanf(p, "%x:%x.%x%n",
3852 					&bus, &slot, &func, &count) != 3) {
3853 				/* Invalid format */
3854 				printk(KERN_ERR "PCI: Can't parse resource_alignment parameter: %s\n",
3855 					p);
3856 				break;
3857 			}
3858 		}
3859 		p += count;
3860 		if (seg == pci_domain_nr(dev->bus) &&
3861 			bus == dev->bus->number &&
3862 			slot == PCI_SLOT(dev->devfn) &&
3863 			func == PCI_FUNC(dev->devfn)) {
3864 			if (align_order == -1) {
3865 				align = PAGE_SIZE;
3866 			} else {
3867 				align = 1 << align_order;
3868 			}
3869 			/* Found */
3870 			break;
3871 		}
3872 		if (*p != ';' && *p != ',') {
3873 			/* End of param or invalid format */
3874 			break;
3875 		}
3876 		p++;
3877 	}
3878 	spin_unlock(&resource_alignment_lock);
3879 	return align;
3880 }
3881 
3882 /**
3883  * pci_is_reassigndev - check if specified PCI is target device to reassign
3884  * @dev: the PCI device to check
3885  *
3886  * RETURNS: non-zero for PCI device is a target device to reassign,
3887  *          or zero is not.
3888  */
3889 int pci_is_reassigndev(struct pci_dev *dev)
3890 {
3891 	return (pci_specified_resource_alignment(dev) != 0);
3892 }
3893 
3894 /*
3895  * This function disables memory decoding and releases memory resources
3896  * of the device specified by kernel's boot parameter 'pci=resource_alignment='.
3897  * It also rounds up size to specified alignment.
3898  * Later on, the kernel will assign page-aligned memory resource back
3899  * to the device.
3900  */
3901 void pci_reassigndev_resource_alignment(struct pci_dev *dev)
3902 {
3903 	int i;
3904 	struct resource *r;
3905 	resource_size_t align, size;
3906 	u16 command;
3907 
3908 	if (!pci_is_reassigndev(dev))
3909 		return;
3910 
3911 	if (dev->hdr_type == PCI_HEADER_TYPE_NORMAL &&
3912 	    (dev->class >> 8) == PCI_CLASS_BRIDGE_HOST) {
3913 		dev_warn(&dev->dev,
3914 			"Can't reassign resources to host bridge.\n");
3915 		return;
3916 	}
3917 
3918 	dev_info(&dev->dev,
3919 		"Disabling memory decoding and releasing memory resources.\n");
3920 	pci_read_config_word(dev, PCI_COMMAND, &command);
3921 	command &= ~PCI_COMMAND_MEMORY;
3922 	pci_write_config_word(dev, PCI_COMMAND, command);
3923 
3924 	align = pci_specified_resource_alignment(dev);
3925 	for (i = 0; i < PCI_BRIDGE_RESOURCES; i++) {
3926 		r = &dev->resource[i];
3927 		if (!(r->flags & IORESOURCE_MEM))
3928 			continue;
3929 		size = resource_size(r);
3930 		if (size < align) {
3931 			size = align;
3932 			dev_info(&dev->dev,
3933 				"Rounding up size of resource #%d to %#llx.\n",
3934 				i, (unsigned long long)size);
3935 		}
3936 		r->end = size - 1;
3937 		r->start = 0;
3938 	}
3939 	/* Need to disable bridge's resource window,
3940 	 * to enable the kernel to reassign new resource
3941 	 * window later on.
3942 	 */
3943 	if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE &&
3944 	    (dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
3945 		for (i = PCI_BRIDGE_RESOURCES; i < PCI_NUM_RESOURCES; i++) {
3946 			r = &dev->resource[i];
3947 			if (!(r->flags & IORESOURCE_MEM))
3948 				continue;
3949 			r->end = resource_size(r) - 1;
3950 			r->start = 0;
3951 		}
3952 		pci_disable_bridge_window(dev);
3953 	}
3954 }
3955 
3956 ssize_t pci_set_resource_alignment_param(const char *buf, size_t count)
3957 {
3958 	if (count > RESOURCE_ALIGNMENT_PARAM_SIZE - 1)
3959 		count = RESOURCE_ALIGNMENT_PARAM_SIZE - 1;
3960 	spin_lock(&resource_alignment_lock);
3961 	strncpy(resource_alignment_param, buf, count);
3962 	resource_alignment_param[count] = '\0';
3963 	spin_unlock(&resource_alignment_lock);
3964 	return count;
3965 }
3966 
3967 ssize_t pci_get_resource_alignment_param(char *buf, size_t size)
3968 {
3969 	size_t count;
3970 	spin_lock(&resource_alignment_lock);
3971 	count = snprintf(buf, size, "%s", resource_alignment_param);
3972 	spin_unlock(&resource_alignment_lock);
3973 	return count;
3974 }
3975 
3976 static ssize_t pci_resource_alignment_show(struct bus_type *bus, char *buf)
3977 {
3978 	return pci_get_resource_alignment_param(buf, PAGE_SIZE);
3979 }
3980 
3981 static ssize_t pci_resource_alignment_store(struct bus_type *bus,
3982 					const char *buf, size_t count)
3983 {
3984 	return pci_set_resource_alignment_param(buf, count);
3985 }
3986 
3987 BUS_ATTR(resource_alignment, 0644, pci_resource_alignment_show,
3988 					pci_resource_alignment_store);
3989 
3990 static int __init pci_resource_alignment_sysfs_init(void)
3991 {
3992 	return bus_create_file(&pci_bus_type,
3993 					&bus_attr_resource_alignment);
3994 }
3995 
3996 late_initcall(pci_resource_alignment_sysfs_init);
3997 
3998 static void __devinit pci_no_domains(void)
3999 {
4000 #ifdef CONFIG_PCI_DOMAINS
4001 	pci_domains_supported = 0;
4002 #endif
4003 }
4004 
4005 /**
4006  * pci_ext_cfg_enabled - can we access extended PCI config space?
4007  * @dev: The PCI device of the root bridge.
4008  *
4009  * Returns 1 if we can access PCI extended config space (offsets
4010  * greater than 0xff). This is the default implementation. Architecture
4011  * implementations can override this.
4012  */
4013 int __weak pci_ext_cfg_avail(struct pci_dev *dev)
4014 {
4015 	return 1;
4016 }
4017 
4018 void __weak pci_fixup_cardbus(struct pci_bus *bus)
4019 {
4020 }
4021 EXPORT_SYMBOL(pci_fixup_cardbus);
4022 
4023 static int __init pci_setup(char *str)
4024 {
4025 	while (str) {
4026 		char *k = strchr(str, ',');
4027 		if (k)
4028 			*k++ = 0;
4029 		if (*str && (str = pcibios_setup(str)) && *str) {
4030 			if (!strcmp(str, "nomsi")) {
4031 				pci_no_msi();
4032 			} else if (!strcmp(str, "noaer")) {
4033 				pci_no_aer();
4034 			} else if (!strncmp(str, "realloc=", 8)) {
4035 				pci_realloc_get_opt(str + 8);
4036 			} else if (!strncmp(str, "realloc", 7)) {
4037 				pci_realloc_get_opt("on");
4038 			} else if (!strcmp(str, "nodomains")) {
4039 				pci_no_domains();
4040 			} else if (!strncmp(str, "noari", 5)) {
4041 				pcie_ari_disabled = true;
4042 			} else if (!strncmp(str, "cbiosize=", 9)) {
4043 				pci_cardbus_io_size = memparse(str + 9, &str);
4044 			} else if (!strncmp(str, "cbmemsize=", 10)) {
4045 				pci_cardbus_mem_size = memparse(str + 10, &str);
4046 			} else if (!strncmp(str, "resource_alignment=", 19)) {
4047 				pci_set_resource_alignment_param(str + 19,
4048 							strlen(str + 19));
4049 			} else if (!strncmp(str, "ecrc=", 5)) {
4050 				pcie_ecrc_get_policy(str + 5);
4051 			} else if (!strncmp(str, "hpiosize=", 9)) {
4052 				pci_hotplug_io_size = memparse(str + 9, &str);
4053 			} else if (!strncmp(str, "hpmemsize=", 10)) {
4054 				pci_hotplug_mem_size = memparse(str + 10, &str);
4055 			} else if (!strncmp(str, "pcie_bus_tune_off", 17)) {
4056 				pcie_bus_config = PCIE_BUS_TUNE_OFF;
4057 			} else if (!strncmp(str, "pcie_bus_safe", 13)) {
4058 				pcie_bus_config = PCIE_BUS_SAFE;
4059 			} else if (!strncmp(str, "pcie_bus_perf", 13)) {
4060 				pcie_bus_config = PCIE_BUS_PERFORMANCE;
4061 			} else if (!strncmp(str, "pcie_bus_peer2peer", 18)) {
4062 				pcie_bus_config = PCIE_BUS_PEER2PEER;
4063 			} else if (!strncmp(str, "pcie_scan_all", 13)) {
4064 				pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS);
4065 			} else {
4066 				printk(KERN_ERR "PCI: Unknown option `%s'\n",
4067 						str);
4068 			}
4069 		}
4070 		str = k;
4071 	}
4072 	return 0;
4073 }
4074 early_param("pci", pci_setup);
4075 
4076 EXPORT_SYMBOL(pci_reenable_device);
4077 EXPORT_SYMBOL(pci_enable_device_io);
4078 EXPORT_SYMBOL(pci_enable_device_mem);
4079 EXPORT_SYMBOL(pci_enable_device);
4080 EXPORT_SYMBOL(pcim_enable_device);
4081 EXPORT_SYMBOL(pcim_pin_device);
4082 EXPORT_SYMBOL(pci_disable_device);
4083 EXPORT_SYMBOL(pci_find_capability);
4084 EXPORT_SYMBOL(pci_bus_find_capability);
4085 EXPORT_SYMBOL(pci_release_regions);
4086 EXPORT_SYMBOL(pci_request_regions);
4087 EXPORT_SYMBOL(pci_request_regions_exclusive);
4088 EXPORT_SYMBOL(pci_release_region);
4089 EXPORT_SYMBOL(pci_request_region);
4090 EXPORT_SYMBOL(pci_request_region_exclusive);
4091 EXPORT_SYMBOL(pci_release_selected_regions);
4092 EXPORT_SYMBOL(pci_request_selected_regions);
4093 EXPORT_SYMBOL(pci_request_selected_regions_exclusive);
4094 EXPORT_SYMBOL(pci_set_master);
4095 EXPORT_SYMBOL(pci_clear_master);
4096 EXPORT_SYMBOL(pci_set_mwi);
4097 EXPORT_SYMBOL(pci_try_set_mwi);
4098 EXPORT_SYMBOL(pci_clear_mwi);
4099 EXPORT_SYMBOL_GPL(pci_intx);
4100 EXPORT_SYMBOL(pci_assign_resource);
4101 EXPORT_SYMBOL(pci_find_parent_resource);
4102 EXPORT_SYMBOL(pci_select_bars);
4103 
4104 EXPORT_SYMBOL(pci_set_power_state);
4105 EXPORT_SYMBOL(pci_save_state);
4106 EXPORT_SYMBOL(pci_restore_state);
4107 EXPORT_SYMBOL(pci_pme_capable);
4108 EXPORT_SYMBOL(pci_pme_active);
4109 EXPORT_SYMBOL(pci_wake_from_d3);
4110 EXPORT_SYMBOL(pci_target_state);
4111 EXPORT_SYMBOL(pci_prepare_to_sleep);
4112 EXPORT_SYMBOL(pci_back_from_sleep);
4113 EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state);
4114