xref: /linux/drivers/pci/pci.c (revision a1087ef6abedf0bfd60e5e3fddf33192cb2c1325)
1 /*
2  *	PCI Bus Services, see include/linux/pci.h for further explanation.
3  *
4  *	Copyright 1993 -- 1997 Drew Eckhardt, Frederic Potter,
5  *	David Mosberger-Tang
6  *
7  *	Copyright 1997 -- 2000 Martin Mares <mj@ucw.cz>
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/delay.h>
12 #include <linux/init.h>
13 #include <linux/pci.h>
14 #include <linux/pm.h>
15 #include <linux/slab.h>
16 #include <linux/module.h>
17 #include <linux/spinlock.h>
18 #include <linux/string.h>
19 #include <linux/log2.h>
20 #include <linux/pci-aspm.h>
21 #include <linux/pm_wakeup.h>
22 #include <linux/interrupt.h>
23 #include <linux/device.h>
24 #include <linux/pm_runtime.h>
25 #include <asm/setup.h>
26 #include "pci.h"
27 
28 const char *pci_power_names[] = {
29 	"error", "D0", "D1", "D2", "D3hot", "D3cold", "unknown",
30 };
31 EXPORT_SYMBOL_GPL(pci_power_names);
32 
33 int isa_dma_bridge_buggy;
34 EXPORT_SYMBOL(isa_dma_bridge_buggy);
35 
36 int pci_pci_problems;
37 EXPORT_SYMBOL(pci_pci_problems);
38 
39 unsigned int pci_pm_d3_delay;
40 
41 static void pci_pme_list_scan(struct work_struct *work);
42 
43 static LIST_HEAD(pci_pme_list);
44 static DEFINE_MUTEX(pci_pme_list_mutex);
45 static DECLARE_DELAYED_WORK(pci_pme_work, pci_pme_list_scan);
46 
47 struct pci_pme_device {
48 	struct list_head list;
49 	struct pci_dev *dev;
50 };
51 
52 #define PME_TIMEOUT 1000 /* How long between PME checks */
53 
54 static void pci_dev_d3_sleep(struct pci_dev *dev)
55 {
56 	unsigned int delay = dev->d3_delay;
57 
58 	if (delay < pci_pm_d3_delay)
59 		delay = pci_pm_d3_delay;
60 
61 	msleep(delay);
62 }
63 
64 #ifdef CONFIG_PCI_DOMAINS
65 int pci_domains_supported = 1;
66 #endif
67 
68 #define DEFAULT_CARDBUS_IO_SIZE		(256)
69 #define DEFAULT_CARDBUS_MEM_SIZE	(64*1024*1024)
70 /* pci=cbmemsize=nnM,cbiosize=nn can override this */
71 unsigned long pci_cardbus_io_size = DEFAULT_CARDBUS_IO_SIZE;
72 unsigned long pci_cardbus_mem_size = DEFAULT_CARDBUS_MEM_SIZE;
73 
74 #define DEFAULT_HOTPLUG_IO_SIZE		(256)
75 #define DEFAULT_HOTPLUG_MEM_SIZE	(2*1024*1024)
76 /* pci=hpmemsize=nnM,hpiosize=nn can override this */
77 unsigned long pci_hotplug_io_size  = DEFAULT_HOTPLUG_IO_SIZE;
78 unsigned long pci_hotplug_mem_size = DEFAULT_HOTPLUG_MEM_SIZE;
79 
80 /*
81  * The default CLS is used if arch didn't set CLS explicitly and not
82  * all pci devices agree on the same value.  Arch can override either
83  * the dfl or actual value as it sees fit.  Don't forget this is
84  * measured in 32-bit words, not bytes.
85  */
86 u8 pci_dfl_cache_line_size __devinitdata = L1_CACHE_BYTES >> 2;
87 u8 pci_cache_line_size;
88 
89 /**
90  * pci_bus_max_busnr - returns maximum PCI bus number of given bus' children
91  * @bus: pointer to PCI bus structure to search
92  *
93  * Given a PCI bus, returns the highest PCI bus number present in the set
94  * including the given PCI bus and its list of child PCI buses.
95  */
96 unsigned char pci_bus_max_busnr(struct pci_bus* bus)
97 {
98 	struct list_head *tmp;
99 	unsigned char max, n;
100 
101 	max = bus->subordinate;
102 	list_for_each(tmp, &bus->children) {
103 		n = pci_bus_max_busnr(pci_bus_b(tmp));
104 		if(n > max)
105 			max = n;
106 	}
107 	return max;
108 }
109 EXPORT_SYMBOL_GPL(pci_bus_max_busnr);
110 
111 #ifdef CONFIG_HAS_IOMEM
112 void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar)
113 {
114 	/*
115 	 * Make sure the BAR is actually a memory resource, not an IO resource
116 	 */
117 	if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM)) {
118 		WARN_ON(1);
119 		return NULL;
120 	}
121 	return ioremap_nocache(pci_resource_start(pdev, bar),
122 				     pci_resource_len(pdev, bar));
123 }
124 EXPORT_SYMBOL_GPL(pci_ioremap_bar);
125 #endif
126 
127 #if 0
128 /**
129  * pci_max_busnr - returns maximum PCI bus number
130  *
131  * Returns the highest PCI bus number present in the system global list of
132  * PCI buses.
133  */
134 unsigned char __devinit
135 pci_max_busnr(void)
136 {
137 	struct pci_bus *bus = NULL;
138 	unsigned char max, n;
139 
140 	max = 0;
141 	while ((bus = pci_find_next_bus(bus)) != NULL) {
142 		n = pci_bus_max_busnr(bus);
143 		if(n > max)
144 			max = n;
145 	}
146 	return max;
147 }
148 
149 #endif  /*  0  */
150 
151 #define PCI_FIND_CAP_TTL	48
152 
153 static int __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn,
154 				   u8 pos, int cap, int *ttl)
155 {
156 	u8 id;
157 
158 	while ((*ttl)--) {
159 		pci_bus_read_config_byte(bus, devfn, pos, &pos);
160 		if (pos < 0x40)
161 			break;
162 		pos &= ~3;
163 		pci_bus_read_config_byte(bus, devfn, pos + PCI_CAP_LIST_ID,
164 					 &id);
165 		if (id == 0xff)
166 			break;
167 		if (id == cap)
168 			return pos;
169 		pos += PCI_CAP_LIST_NEXT;
170 	}
171 	return 0;
172 }
173 
174 static int __pci_find_next_cap(struct pci_bus *bus, unsigned int devfn,
175 			       u8 pos, int cap)
176 {
177 	int ttl = PCI_FIND_CAP_TTL;
178 
179 	return __pci_find_next_cap_ttl(bus, devfn, pos, cap, &ttl);
180 }
181 
182 int pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap)
183 {
184 	return __pci_find_next_cap(dev->bus, dev->devfn,
185 				   pos + PCI_CAP_LIST_NEXT, cap);
186 }
187 EXPORT_SYMBOL_GPL(pci_find_next_capability);
188 
189 static int __pci_bus_find_cap_start(struct pci_bus *bus,
190 				    unsigned int devfn, u8 hdr_type)
191 {
192 	u16 status;
193 
194 	pci_bus_read_config_word(bus, devfn, PCI_STATUS, &status);
195 	if (!(status & PCI_STATUS_CAP_LIST))
196 		return 0;
197 
198 	switch (hdr_type) {
199 	case PCI_HEADER_TYPE_NORMAL:
200 	case PCI_HEADER_TYPE_BRIDGE:
201 		return PCI_CAPABILITY_LIST;
202 	case PCI_HEADER_TYPE_CARDBUS:
203 		return PCI_CB_CAPABILITY_LIST;
204 	default:
205 		return 0;
206 	}
207 
208 	return 0;
209 }
210 
211 /**
212  * pci_find_capability - query for devices' capabilities
213  * @dev: PCI device to query
214  * @cap: capability code
215  *
216  * Tell if a device supports a given PCI capability.
217  * Returns the address of the requested capability structure within the
218  * device's PCI configuration space or 0 in case the device does not
219  * support it.  Possible values for @cap:
220  *
221  *  %PCI_CAP_ID_PM           Power Management
222  *  %PCI_CAP_ID_AGP          Accelerated Graphics Port
223  *  %PCI_CAP_ID_VPD          Vital Product Data
224  *  %PCI_CAP_ID_SLOTID       Slot Identification
225  *  %PCI_CAP_ID_MSI          Message Signalled Interrupts
226  *  %PCI_CAP_ID_CHSWP        CompactPCI HotSwap
227  *  %PCI_CAP_ID_PCIX         PCI-X
228  *  %PCI_CAP_ID_EXP          PCI Express
229  */
230 int pci_find_capability(struct pci_dev *dev, int cap)
231 {
232 	int pos;
233 
234 	pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);
235 	if (pos)
236 		pos = __pci_find_next_cap(dev->bus, dev->devfn, pos, cap);
237 
238 	return pos;
239 }
240 
241 /**
242  * pci_bus_find_capability - query for devices' capabilities
243  * @bus:   the PCI bus to query
244  * @devfn: PCI device to query
245  * @cap:   capability code
246  *
247  * Like pci_find_capability() but works for pci devices that do not have a
248  * pci_dev structure set up yet.
249  *
250  * Returns the address of the requested capability structure within the
251  * device's PCI configuration space or 0 in case the device does not
252  * support it.
253  */
254 int pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap)
255 {
256 	int pos;
257 	u8 hdr_type;
258 
259 	pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &hdr_type);
260 
261 	pos = __pci_bus_find_cap_start(bus, devfn, hdr_type & 0x7f);
262 	if (pos)
263 		pos = __pci_find_next_cap(bus, devfn, pos, cap);
264 
265 	return pos;
266 }
267 
268 /**
269  * pci_find_ext_capability - Find an extended capability
270  * @dev: PCI device to query
271  * @cap: capability code
272  *
273  * Returns the address of the requested extended capability structure
274  * within the device's PCI configuration space or 0 if the device does
275  * not support it.  Possible values for @cap:
276  *
277  *  %PCI_EXT_CAP_ID_ERR		Advanced Error Reporting
278  *  %PCI_EXT_CAP_ID_VC		Virtual Channel
279  *  %PCI_EXT_CAP_ID_DSN		Device Serial Number
280  *  %PCI_EXT_CAP_ID_PWR		Power Budgeting
281  */
282 int pci_find_ext_capability(struct pci_dev *dev, int cap)
283 {
284 	u32 header;
285 	int ttl;
286 	int pos = PCI_CFG_SPACE_SIZE;
287 
288 	/* minimum 8 bytes per capability */
289 	ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8;
290 
291 	if (dev->cfg_size <= PCI_CFG_SPACE_SIZE)
292 		return 0;
293 
294 	if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
295 		return 0;
296 
297 	/*
298 	 * If we have no capabilities, this is indicated by cap ID,
299 	 * cap version and next pointer all being 0.
300 	 */
301 	if (header == 0)
302 		return 0;
303 
304 	while (ttl-- > 0) {
305 		if (PCI_EXT_CAP_ID(header) == cap)
306 			return pos;
307 
308 		pos = PCI_EXT_CAP_NEXT(header);
309 		if (pos < PCI_CFG_SPACE_SIZE)
310 			break;
311 
312 		if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
313 			break;
314 	}
315 
316 	return 0;
317 }
318 EXPORT_SYMBOL_GPL(pci_find_ext_capability);
319 
320 /**
321  * pci_bus_find_ext_capability - find an extended capability
322  * @bus:   the PCI bus to query
323  * @devfn: PCI device to query
324  * @cap:   capability code
325  *
326  * Like pci_find_ext_capability() but works for pci devices that do not have a
327  * pci_dev structure set up yet.
328  *
329  * Returns the address of the requested capability structure within the
330  * device's PCI configuration space or 0 in case the device does not
331  * support it.
332  */
333 int pci_bus_find_ext_capability(struct pci_bus *bus, unsigned int devfn,
334 				int cap)
335 {
336 	u32 header;
337 	int ttl;
338 	int pos = PCI_CFG_SPACE_SIZE;
339 
340 	/* minimum 8 bytes per capability */
341 	ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8;
342 
343 	if (!pci_bus_read_config_dword(bus, devfn, pos, &header))
344 		return 0;
345 	if (header == 0xffffffff || header == 0)
346 		return 0;
347 
348 	while (ttl-- > 0) {
349 		if (PCI_EXT_CAP_ID(header) == cap)
350 			return pos;
351 
352 		pos = PCI_EXT_CAP_NEXT(header);
353 		if (pos < PCI_CFG_SPACE_SIZE)
354 			break;
355 
356 		if (!pci_bus_read_config_dword(bus, devfn, pos, &header))
357 			break;
358 	}
359 
360 	return 0;
361 }
362 
363 static int __pci_find_next_ht_cap(struct pci_dev *dev, int pos, int ht_cap)
364 {
365 	int rc, ttl = PCI_FIND_CAP_TTL;
366 	u8 cap, mask;
367 
368 	if (ht_cap == HT_CAPTYPE_SLAVE || ht_cap == HT_CAPTYPE_HOST)
369 		mask = HT_3BIT_CAP_MASK;
370 	else
371 		mask = HT_5BIT_CAP_MASK;
372 
373 	pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn, pos,
374 				      PCI_CAP_ID_HT, &ttl);
375 	while (pos) {
376 		rc = pci_read_config_byte(dev, pos + 3, &cap);
377 		if (rc != PCIBIOS_SUCCESSFUL)
378 			return 0;
379 
380 		if ((cap & mask) == ht_cap)
381 			return pos;
382 
383 		pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn,
384 					      pos + PCI_CAP_LIST_NEXT,
385 					      PCI_CAP_ID_HT, &ttl);
386 	}
387 
388 	return 0;
389 }
390 /**
391  * pci_find_next_ht_capability - query a device's Hypertransport capabilities
392  * @dev: PCI device to query
393  * @pos: Position from which to continue searching
394  * @ht_cap: Hypertransport capability code
395  *
396  * To be used in conjunction with pci_find_ht_capability() to search for
397  * all capabilities matching @ht_cap. @pos should always be a value returned
398  * from pci_find_ht_capability().
399  *
400  * NB. To be 100% safe against broken PCI devices, the caller should take
401  * steps to avoid an infinite loop.
402  */
403 int pci_find_next_ht_capability(struct pci_dev *dev, int pos, int ht_cap)
404 {
405 	return __pci_find_next_ht_cap(dev, pos + PCI_CAP_LIST_NEXT, ht_cap);
406 }
407 EXPORT_SYMBOL_GPL(pci_find_next_ht_capability);
408 
409 /**
410  * pci_find_ht_capability - query a device's Hypertransport capabilities
411  * @dev: PCI device to query
412  * @ht_cap: Hypertransport capability code
413  *
414  * Tell if a device supports a given Hypertransport capability.
415  * Returns an address within the device's PCI configuration space
416  * or 0 in case the device does not support the request capability.
417  * The address points to the PCI capability, of type PCI_CAP_ID_HT,
418  * which has a Hypertransport capability matching @ht_cap.
419  */
420 int pci_find_ht_capability(struct pci_dev *dev, int ht_cap)
421 {
422 	int pos;
423 
424 	pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);
425 	if (pos)
426 		pos = __pci_find_next_ht_cap(dev, pos, ht_cap);
427 
428 	return pos;
429 }
430 EXPORT_SYMBOL_GPL(pci_find_ht_capability);
431 
432 /**
433  * pci_find_parent_resource - return resource region of parent bus of given region
434  * @dev: PCI device structure contains resources to be searched
435  * @res: child resource record for which parent is sought
436  *
437  *  For given resource region of given device, return the resource
438  *  region of parent bus the given region is contained in or where
439  *  it should be allocated from.
440  */
441 struct resource *
442 pci_find_parent_resource(const struct pci_dev *dev, struct resource *res)
443 {
444 	const struct pci_bus *bus = dev->bus;
445 	int i;
446 	struct resource *best = NULL, *r;
447 
448 	pci_bus_for_each_resource(bus, r, i) {
449 		if (!r)
450 			continue;
451 		if (res->start && !(res->start >= r->start && res->end <= r->end))
452 			continue;	/* Not contained */
453 		if ((res->flags ^ r->flags) & (IORESOURCE_IO | IORESOURCE_MEM))
454 			continue;	/* Wrong type */
455 		if (!((res->flags ^ r->flags) & IORESOURCE_PREFETCH))
456 			return r;	/* Exact match */
457 		/* We can't insert a non-prefetch resource inside a prefetchable parent .. */
458 		if (r->flags & IORESOURCE_PREFETCH)
459 			continue;
460 		/* .. but we can put a prefetchable resource inside a non-prefetchable one */
461 		if (!best)
462 			best = r;
463 	}
464 	return best;
465 }
466 
467 /**
468  * pci_restore_bars - restore a devices BAR values (e.g. after wake-up)
469  * @dev: PCI device to have its BARs restored
470  *
471  * Restore the BAR values for a given device, so as to make it
472  * accessible by its driver.
473  */
474 static void
475 pci_restore_bars(struct pci_dev *dev)
476 {
477 	int i;
478 
479 	for (i = 0; i < PCI_BRIDGE_RESOURCES; i++)
480 		pci_update_resource(dev, i);
481 }
482 
483 static struct pci_platform_pm_ops *pci_platform_pm;
484 
485 int pci_set_platform_pm(struct pci_platform_pm_ops *ops)
486 {
487 	if (!ops->is_manageable || !ops->set_state || !ops->choose_state
488 	    || !ops->sleep_wake || !ops->can_wakeup)
489 		return -EINVAL;
490 	pci_platform_pm = ops;
491 	return 0;
492 }
493 
494 static inline bool platform_pci_power_manageable(struct pci_dev *dev)
495 {
496 	return pci_platform_pm ? pci_platform_pm->is_manageable(dev) : false;
497 }
498 
499 static inline int platform_pci_set_power_state(struct pci_dev *dev,
500                                                 pci_power_t t)
501 {
502 	return pci_platform_pm ? pci_platform_pm->set_state(dev, t) : -ENOSYS;
503 }
504 
505 static inline pci_power_t platform_pci_choose_state(struct pci_dev *dev)
506 {
507 	return pci_platform_pm ?
508 			pci_platform_pm->choose_state(dev) : PCI_POWER_ERROR;
509 }
510 
511 static inline bool platform_pci_can_wakeup(struct pci_dev *dev)
512 {
513 	return pci_platform_pm ? pci_platform_pm->can_wakeup(dev) : false;
514 }
515 
516 static inline int platform_pci_sleep_wake(struct pci_dev *dev, bool enable)
517 {
518 	return pci_platform_pm ?
519 			pci_platform_pm->sleep_wake(dev, enable) : -ENODEV;
520 }
521 
522 static inline int platform_pci_run_wake(struct pci_dev *dev, bool enable)
523 {
524 	return pci_platform_pm ?
525 			pci_platform_pm->run_wake(dev, enable) : -ENODEV;
526 }
527 
528 /**
529  * pci_raw_set_power_state - Use PCI PM registers to set the power state of
530  *                           given PCI device
531  * @dev: PCI device to handle.
532  * @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
533  *
534  * RETURN VALUE:
535  * -EINVAL if the requested state is invalid.
536  * -EIO if device does not support PCI PM or its PM capabilities register has a
537  * wrong version, or device doesn't support the requested state.
538  * 0 if device already is in the requested state.
539  * 0 if device's power state has been successfully changed.
540  */
541 static int pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
542 {
543 	u16 pmcsr;
544 	bool need_restore = false;
545 
546 	/* Check if we're already there */
547 	if (dev->current_state == state)
548 		return 0;
549 
550 	if (!dev->pm_cap)
551 		return -EIO;
552 
553 	if (state < PCI_D0 || state > PCI_D3hot)
554 		return -EINVAL;
555 
556 	/* Validate current state:
557 	 * Can enter D0 from any state, but if we can only go deeper
558 	 * to sleep if we're already in a low power state
559 	 */
560 	if (state != PCI_D0 && dev->current_state <= PCI_D3cold
561 	    && dev->current_state > state) {
562 		dev_err(&dev->dev, "invalid power transition "
563 			"(from state %d to %d)\n", dev->current_state, state);
564 		return -EINVAL;
565 	}
566 
567 	/* check if this device supports the desired state */
568 	if ((state == PCI_D1 && !dev->d1_support)
569 	   || (state == PCI_D2 && !dev->d2_support))
570 		return -EIO;
571 
572 	pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
573 
574 	/* If we're (effectively) in D3, force entire word to 0.
575 	 * This doesn't affect PME_Status, disables PME_En, and
576 	 * sets PowerState to 0.
577 	 */
578 	switch (dev->current_state) {
579 	case PCI_D0:
580 	case PCI_D1:
581 	case PCI_D2:
582 		pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
583 		pmcsr |= state;
584 		break;
585 	case PCI_D3hot:
586 	case PCI_D3cold:
587 	case PCI_UNKNOWN: /* Boot-up */
588 		if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot
589 		 && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))
590 			need_restore = true;
591 		/* Fall-through: force to D0 */
592 	default:
593 		pmcsr = 0;
594 		break;
595 	}
596 
597 	/* enter specified state */
598 	pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
599 
600 	/* Mandatory power management transition delays */
601 	/* see PCI PM 1.1 5.6.1 table 18 */
602 	if (state == PCI_D3hot || dev->current_state == PCI_D3hot)
603 		pci_dev_d3_sleep(dev);
604 	else if (state == PCI_D2 || dev->current_state == PCI_D2)
605 		udelay(PCI_PM_D2_DELAY);
606 
607 	pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
608 	dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
609 	if (dev->current_state != state && printk_ratelimit())
610 		dev_info(&dev->dev, "Refused to change power state, "
611 			"currently in D%d\n", dev->current_state);
612 
613 	/* According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT
614 	 * INTERFACE SPECIFICATION, REV. 1.2", a device transitioning
615 	 * from D3hot to D0 _may_ perform an internal reset, thereby
616 	 * going to "D0 Uninitialized" rather than "D0 Initialized".
617 	 * For example, at least some versions of the 3c905B and the
618 	 * 3c556B exhibit this behaviour.
619 	 *
620 	 * At least some laptop BIOSen (e.g. the Thinkpad T21) leave
621 	 * devices in a D3hot state at boot.  Consequently, we need to
622 	 * restore at least the BARs so that the device will be
623 	 * accessible to its driver.
624 	 */
625 	if (need_restore)
626 		pci_restore_bars(dev);
627 
628 	if (dev->bus->self)
629 		pcie_aspm_pm_state_change(dev->bus->self);
630 
631 	return 0;
632 }
633 
634 /**
635  * pci_update_current_state - Read PCI power state of given device from its
636  *                            PCI PM registers and cache it
637  * @dev: PCI device to handle.
638  * @state: State to cache in case the device doesn't have the PM capability
639  */
640 void pci_update_current_state(struct pci_dev *dev, pci_power_t state)
641 {
642 	if (dev->pm_cap) {
643 		u16 pmcsr;
644 
645 		pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
646 		dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
647 	} else {
648 		dev->current_state = state;
649 	}
650 }
651 
652 /**
653  * pci_platform_power_transition - Use platform to change device power state
654  * @dev: PCI device to handle.
655  * @state: State to put the device into.
656  */
657 static int pci_platform_power_transition(struct pci_dev *dev, pci_power_t state)
658 {
659 	int error;
660 
661 	if (platform_pci_power_manageable(dev)) {
662 		error = platform_pci_set_power_state(dev, state);
663 		if (!error)
664 			pci_update_current_state(dev, state);
665 	} else {
666 		error = -ENODEV;
667 		/* Fall back to PCI_D0 if native PM is not supported */
668 		if (!dev->pm_cap)
669 			dev->current_state = PCI_D0;
670 	}
671 
672 	return error;
673 }
674 
675 /**
676  * __pci_start_power_transition - Start power transition of a PCI device
677  * @dev: PCI device to handle.
678  * @state: State to put the device into.
679  */
680 static void __pci_start_power_transition(struct pci_dev *dev, pci_power_t state)
681 {
682 	if (state == PCI_D0)
683 		pci_platform_power_transition(dev, PCI_D0);
684 }
685 
686 /**
687  * __pci_complete_power_transition - Complete power transition of a PCI device
688  * @dev: PCI device to handle.
689  * @state: State to put the device into.
690  *
691  * This function should not be called directly by device drivers.
692  */
693 int __pci_complete_power_transition(struct pci_dev *dev, pci_power_t state)
694 {
695 	return state >= PCI_D0 ?
696 			pci_platform_power_transition(dev, state) : -EINVAL;
697 }
698 EXPORT_SYMBOL_GPL(__pci_complete_power_transition);
699 
700 /**
701  * pci_set_power_state - Set the power state of a PCI device
702  * @dev: PCI device to handle.
703  * @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
704  *
705  * Transition a device to a new power state, using the platform firmware and/or
706  * the device's PCI PM registers.
707  *
708  * RETURN VALUE:
709  * -EINVAL if the requested state is invalid.
710  * -EIO if device does not support PCI PM or its PM capabilities register has a
711  * wrong version, or device doesn't support the requested state.
712  * 0 if device already is in the requested state.
713  * 0 if device's power state has been successfully changed.
714  */
715 int pci_set_power_state(struct pci_dev *dev, pci_power_t state)
716 {
717 	int error;
718 
719 	/* bound the state we're entering */
720 	if (state > PCI_D3hot)
721 		state = PCI_D3hot;
722 	else if (state < PCI_D0)
723 		state = PCI_D0;
724 	else if ((state == PCI_D1 || state == PCI_D2) && pci_no_d1d2(dev))
725 		/*
726 		 * If the device or the parent bridge do not support PCI PM,
727 		 * ignore the request if we're doing anything other than putting
728 		 * it into D0 (which would only happen on boot).
729 		 */
730 		return 0;
731 
732 	__pci_start_power_transition(dev, state);
733 
734 	/* This device is quirked not to be put into D3, so
735 	   don't put it in D3 */
736 	if (state == PCI_D3hot && (dev->dev_flags & PCI_DEV_FLAGS_NO_D3))
737 		return 0;
738 
739 	error = pci_raw_set_power_state(dev, state);
740 
741 	if (!__pci_complete_power_transition(dev, state))
742 		error = 0;
743 
744 	return error;
745 }
746 
747 /**
748  * pci_choose_state - Choose the power state of a PCI device
749  * @dev: PCI device to be suspended
750  * @state: target sleep state for the whole system. This is the value
751  *	that is passed to suspend() function.
752  *
753  * Returns PCI power state suitable for given device and given system
754  * message.
755  */
756 
757 pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state)
758 {
759 	pci_power_t ret;
760 
761 	if (!pci_find_capability(dev, PCI_CAP_ID_PM))
762 		return PCI_D0;
763 
764 	ret = platform_pci_choose_state(dev);
765 	if (ret != PCI_POWER_ERROR)
766 		return ret;
767 
768 	switch (state.event) {
769 	case PM_EVENT_ON:
770 		return PCI_D0;
771 	case PM_EVENT_FREEZE:
772 	case PM_EVENT_PRETHAW:
773 		/* REVISIT both freeze and pre-thaw "should" use D0 */
774 	case PM_EVENT_SUSPEND:
775 	case PM_EVENT_HIBERNATE:
776 		return PCI_D3hot;
777 	default:
778 		dev_info(&dev->dev, "unrecognized suspend event %d\n",
779 			 state.event);
780 		BUG();
781 	}
782 	return PCI_D0;
783 }
784 
785 EXPORT_SYMBOL(pci_choose_state);
786 
787 #define PCI_EXP_SAVE_REGS	7
788 
789 #define pcie_cap_has_devctl(type, flags)	1
790 #define pcie_cap_has_lnkctl(type, flags)		\
791 		((flags & PCI_EXP_FLAGS_VERS) > 1 ||	\
792 		 (type == PCI_EXP_TYPE_ROOT_PORT ||	\
793 		  type == PCI_EXP_TYPE_ENDPOINT ||	\
794 		  type == PCI_EXP_TYPE_LEG_END))
795 #define pcie_cap_has_sltctl(type, flags)		\
796 		((flags & PCI_EXP_FLAGS_VERS) > 1 ||	\
797 		 ((type == PCI_EXP_TYPE_ROOT_PORT) ||	\
798 		  (type == PCI_EXP_TYPE_DOWNSTREAM &&	\
799 		   (flags & PCI_EXP_FLAGS_SLOT))))
800 #define pcie_cap_has_rtctl(type, flags)			\
801 		((flags & PCI_EXP_FLAGS_VERS) > 1 ||	\
802 		 (type == PCI_EXP_TYPE_ROOT_PORT ||	\
803 		  type == PCI_EXP_TYPE_RC_EC))
804 #define pcie_cap_has_devctl2(type, flags)		\
805 		((flags & PCI_EXP_FLAGS_VERS) > 1)
806 #define pcie_cap_has_lnkctl2(type, flags)		\
807 		((flags & PCI_EXP_FLAGS_VERS) > 1)
808 #define pcie_cap_has_sltctl2(type, flags)		\
809 		((flags & PCI_EXP_FLAGS_VERS) > 1)
810 
811 static int pci_save_pcie_state(struct pci_dev *dev)
812 {
813 	int pos, i = 0;
814 	struct pci_cap_saved_state *save_state;
815 	u16 *cap;
816 	u16 flags;
817 
818 	pos = pci_pcie_cap(dev);
819 	if (!pos)
820 		return 0;
821 
822 	save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
823 	if (!save_state) {
824 		dev_err(&dev->dev, "buffer not found in %s\n", __func__);
825 		return -ENOMEM;
826 	}
827 	cap = (u16 *)&save_state->data[0];
828 
829 	pci_read_config_word(dev, pos + PCI_EXP_FLAGS, &flags);
830 
831 	if (pcie_cap_has_devctl(dev->pcie_type, flags))
832 		pci_read_config_word(dev, pos + PCI_EXP_DEVCTL, &cap[i++]);
833 	if (pcie_cap_has_lnkctl(dev->pcie_type, flags))
834 		pci_read_config_word(dev, pos + PCI_EXP_LNKCTL, &cap[i++]);
835 	if (pcie_cap_has_sltctl(dev->pcie_type, flags))
836 		pci_read_config_word(dev, pos + PCI_EXP_SLTCTL, &cap[i++]);
837 	if (pcie_cap_has_rtctl(dev->pcie_type, flags))
838 		pci_read_config_word(dev, pos + PCI_EXP_RTCTL, &cap[i++]);
839 	if (pcie_cap_has_devctl2(dev->pcie_type, flags))
840 		pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &cap[i++]);
841 	if (pcie_cap_has_lnkctl2(dev->pcie_type, flags))
842 		pci_read_config_word(dev, pos + PCI_EXP_LNKCTL2, &cap[i++]);
843 	if (pcie_cap_has_sltctl2(dev->pcie_type, flags))
844 		pci_read_config_word(dev, pos + PCI_EXP_SLTCTL2, &cap[i++]);
845 
846 	return 0;
847 }
848 
849 static void pci_restore_pcie_state(struct pci_dev *dev)
850 {
851 	int i = 0, pos;
852 	struct pci_cap_saved_state *save_state;
853 	u16 *cap;
854 	u16 flags;
855 
856 	save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
857 	pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
858 	if (!save_state || pos <= 0)
859 		return;
860 	cap = (u16 *)&save_state->data[0];
861 
862 	pci_read_config_word(dev, pos + PCI_EXP_FLAGS, &flags);
863 
864 	if (pcie_cap_has_devctl(dev->pcie_type, flags))
865 		pci_write_config_word(dev, pos + PCI_EXP_DEVCTL, cap[i++]);
866 	if (pcie_cap_has_lnkctl(dev->pcie_type, flags))
867 		pci_write_config_word(dev, pos + PCI_EXP_LNKCTL, cap[i++]);
868 	if (pcie_cap_has_sltctl(dev->pcie_type, flags))
869 		pci_write_config_word(dev, pos + PCI_EXP_SLTCTL, cap[i++]);
870 	if (pcie_cap_has_rtctl(dev->pcie_type, flags))
871 		pci_write_config_word(dev, pos + PCI_EXP_RTCTL, cap[i++]);
872 	if (pcie_cap_has_devctl2(dev->pcie_type, flags))
873 		pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, cap[i++]);
874 	if (pcie_cap_has_lnkctl2(dev->pcie_type, flags))
875 		pci_write_config_word(dev, pos + PCI_EXP_LNKCTL2, cap[i++]);
876 	if (pcie_cap_has_sltctl2(dev->pcie_type, flags))
877 		pci_write_config_word(dev, pos + PCI_EXP_SLTCTL2, cap[i++]);
878 }
879 
880 
881 static int pci_save_pcix_state(struct pci_dev *dev)
882 {
883 	int pos;
884 	struct pci_cap_saved_state *save_state;
885 
886 	pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
887 	if (pos <= 0)
888 		return 0;
889 
890 	save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX);
891 	if (!save_state) {
892 		dev_err(&dev->dev, "buffer not found in %s\n", __func__);
893 		return -ENOMEM;
894 	}
895 
896 	pci_read_config_word(dev, pos + PCI_X_CMD, (u16 *)save_state->data);
897 
898 	return 0;
899 }
900 
901 static void pci_restore_pcix_state(struct pci_dev *dev)
902 {
903 	int i = 0, pos;
904 	struct pci_cap_saved_state *save_state;
905 	u16 *cap;
906 
907 	save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX);
908 	pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
909 	if (!save_state || pos <= 0)
910 		return;
911 	cap = (u16 *)&save_state->data[0];
912 
913 	pci_write_config_word(dev, pos + PCI_X_CMD, cap[i++]);
914 }
915 
916 
917 /**
918  * pci_save_state - save the PCI configuration space of a device before suspending
919  * @dev: - PCI device that we're dealing with
920  */
921 int
922 pci_save_state(struct pci_dev *dev)
923 {
924 	int i;
925 	/* XXX: 100% dword access ok here? */
926 	for (i = 0; i < 16; i++)
927 		pci_read_config_dword(dev, i * 4, &dev->saved_config_space[i]);
928 	dev->state_saved = true;
929 	if ((i = pci_save_pcie_state(dev)) != 0)
930 		return i;
931 	if ((i = pci_save_pcix_state(dev)) != 0)
932 		return i;
933 	return 0;
934 }
935 
936 /**
937  * pci_restore_state - Restore the saved state of a PCI device
938  * @dev: - PCI device that we're dealing with
939  */
940 int
941 pci_restore_state(struct pci_dev *dev)
942 {
943 	int i;
944 	u32 val;
945 
946 	if (!dev->state_saved)
947 		return 0;
948 
949 	/* PCI Express register must be restored first */
950 	pci_restore_pcie_state(dev);
951 
952 	/*
953 	 * The Base Address register should be programmed before the command
954 	 * register(s)
955 	 */
956 	for (i = 15; i >= 0; i--) {
957 		pci_read_config_dword(dev, i * 4, &val);
958 		if (val != dev->saved_config_space[i]) {
959 			dev_printk(KERN_DEBUG, &dev->dev, "restoring config "
960 				"space at offset %#x (was %#x, writing %#x)\n",
961 				i, val, (int)dev->saved_config_space[i]);
962 			pci_write_config_dword(dev,i * 4,
963 				dev->saved_config_space[i]);
964 		}
965 	}
966 	pci_restore_pcix_state(dev);
967 	pci_restore_msi_state(dev);
968 	pci_restore_iov_state(dev);
969 
970 	dev->state_saved = false;
971 
972 	return 0;
973 }
974 
975 static int do_pci_enable_device(struct pci_dev *dev, int bars)
976 {
977 	int err;
978 
979 	err = pci_set_power_state(dev, PCI_D0);
980 	if (err < 0 && err != -EIO)
981 		return err;
982 	err = pcibios_enable_device(dev, bars);
983 	if (err < 0)
984 		return err;
985 	pci_fixup_device(pci_fixup_enable, dev);
986 
987 	return 0;
988 }
989 
990 /**
991  * pci_reenable_device - Resume abandoned device
992  * @dev: PCI device to be resumed
993  *
994  *  Note this function is a backend of pci_default_resume and is not supposed
995  *  to be called by normal code, write proper resume handler and use it instead.
996  */
997 int pci_reenable_device(struct pci_dev *dev)
998 {
999 	if (pci_is_enabled(dev))
1000 		return do_pci_enable_device(dev, (1 << PCI_NUM_RESOURCES) - 1);
1001 	return 0;
1002 }
1003 
1004 static int __pci_enable_device_flags(struct pci_dev *dev,
1005 				     resource_size_t flags)
1006 {
1007 	int err;
1008 	int i, bars = 0;
1009 
1010 	if (atomic_add_return(1, &dev->enable_cnt) > 1)
1011 		return 0;		/* already enabled */
1012 
1013 	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++)
1014 		if (dev->resource[i].flags & flags)
1015 			bars |= (1 << i);
1016 
1017 	err = do_pci_enable_device(dev, bars);
1018 	if (err < 0)
1019 		atomic_dec(&dev->enable_cnt);
1020 	return err;
1021 }
1022 
1023 /**
1024  * pci_enable_device_io - Initialize a device for use with IO space
1025  * @dev: PCI device to be initialized
1026  *
1027  *  Initialize device before it's used by a driver. Ask low-level code
1028  *  to enable I/O resources. Wake up the device if it was suspended.
1029  *  Beware, this function can fail.
1030  */
1031 int pci_enable_device_io(struct pci_dev *dev)
1032 {
1033 	return __pci_enable_device_flags(dev, IORESOURCE_IO);
1034 }
1035 
1036 /**
1037  * pci_enable_device_mem - Initialize a device for use with Memory space
1038  * @dev: PCI device to be initialized
1039  *
1040  *  Initialize device before it's used by a driver. Ask low-level code
1041  *  to enable Memory resources. Wake up the device if it was suspended.
1042  *  Beware, this function can fail.
1043  */
1044 int pci_enable_device_mem(struct pci_dev *dev)
1045 {
1046 	return __pci_enable_device_flags(dev, IORESOURCE_MEM);
1047 }
1048 
1049 /**
1050  * pci_enable_device - Initialize device before it's used by a driver.
1051  * @dev: PCI device to be initialized
1052  *
1053  *  Initialize device before it's used by a driver. Ask low-level code
1054  *  to enable I/O and memory. Wake up the device if it was suspended.
1055  *  Beware, this function can fail.
1056  *
1057  *  Note we don't actually enable the device many times if we call
1058  *  this function repeatedly (we just increment the count).
1059  */
1060 int pci_enable_device(struct pci_dev *dev)
1061 {
1062 	return __pci_enable_device_flags(dev, IORESOURCE_MEM | IORESOURCE_IO);
1063 }
1064 
1065 /*
1066  * Managed PCI resources.  This manages device on/off, intx/msi/msix
1067  * on/off and BAR regions.  pci_dev itself records msi/msix status, so
1068  * there's no need to track it separately.  pci_devres is initialized
1069  * when a device is enabled using managed PCI device enable interface.
1070  */
1071 struct pci_devres {
1072 	unsigned int enabled:1;
1073 	unsigned int pinned:1;
1074 	unsigned int orig_intx:1;
1075 	unsigned int restore_intx:1;
1076 	u32 region_mask;
1077 };
1078 
1079 static void pcim_release(struct device *gendev, void *res)
1080 {
1081 	struct pci_dev *dev = container_of(gendev, struct pci_dev, dev);
1082 	struct pci_devres *this = res;
1083 	int i;
1084 
1085 	if (dev->msi_enabled)
1086 		pci_disable_msi(dev);
1087 	if (dev->msix_enabled)
1088 		pci_disable_msix(dev);
1089 
1090 	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++)
1091 		if (this->region_mask & (1 << i))
1092 			pci_release_region(dev, i);
1093 
1094 	if (this->restore_intx)
1095 		pci_intx(dev, this->orig_intx);
1096 
1097 	if (this->enabled && !this->pinned)
1098 		pci_disable_device(dev);
1099 }
1100 
1101 static struct pci_devres * get_pci_dr(struct pci_dev *pdev)
1102 {
1103 	struct pci_devres *dr, *new_dr;
1104 
1105 	dr = devres_find(&pdev->dev, pcim_release, NULL, NULL);
1106 	if (dr)
1107 		return dr;
1108 
1109 	new_dr = devres_alloc(pcim_release, sizeof(*new_dr), GFP_KERNEL);
1110 	if (!new_dr)
1111 		return NULL;
1112 	return devres_get(&pdev->dev, new_dr, NULL, NULL);
1113 }
1114 
1115 static struct pci_devres * find_pci_dr(struct pci_dev *pdev)
1116 {
1117 	if (pci_is_managed(pdev))
1118 		return devres_find(&pdev->dev, pcim_release, NULL, NULL);
1119 	return NULL;
1120 }
1121 
1122 /**
1123  * pcim_enable_device - Managed pci_enable_device()
1124  * @pdev: PCI device to be initialized
1125  *
1126  * Managed pci_enable_device().
1127  */
1128 int pcim_enable_device(struct pci_dev *pdev)
1129 {
1130 	struct pci_devres *dr;
1131 	int rc;
1132 
1133 	dr = get_pci_dr(pdev);
1134 	if (unlikely(!dr))
1135 		return -ENOMEM;
1136 	if (dr->enabled)
1137 		return 0;
1138 
1139 	rc = pci_enable_device(pdev);
1140 	if (!rc) {
1141 		pdev->is_managed = 1;
1142 		dr->enabled = 1;
1143 	}
1144 	return rc;
1145 }
1146 
1147 /**
1148  * pcim_pin_device - Pin managed PCI device
1149  * @pdev: PCI device to pin
1150  *
1151  * Pin managed PCI device @pdev.  Pinned device won't be disabled on
1152  * driver detach.  @pdev must have been enabled with
1153  * pcim_enable_device().
1154  */
1155 void pcim_pin_device(struct pci_dev *pdev)
1156 {
1157 	struct pci_devres *dr;
1158 
1159 	dr = find_pci_dr(pdev);
1160 	WARN_ON(!dr || !dr->enabled);
1161 	if (dr)
1162 		dr->pinned = 1;
1163 }
1164 
1165 /**
1166  * pcibios_disable_device - disable arch specific PCI resources for device dev
1167  * @dev: the PCI device to disable
1168  *
1169  * Disables architecture specific PCI resources for the device. This
1170  * is the default implementation. Architecture implementations can
1171  * override this.
1172  */
1173 void __attribute__ ((weak)) pcibios_disable_device (struct pci_dev *dev) {}
1174 
1175 static void do_pci_disable_device(struct pci_dev *dev)
1176 {
1177 	u16 pci_command;
1178 
1179 	pci_read_config_word(dev, PCI_COMMAND, &pci_command);
1180 	if (pci_command & PCI_COMMAND_MASTER) {
1181 		pci_command &= ~PCI_COMMAND_MASTER;
1182 		pci_write_config_word(dev, PCI_COMMAND, pci_command);
1183 	}
1184 
1185 	pcibios_disable_device(dev);
1186 }
1187 
1188 /**
1189  * pci_disable_enabled_device - Disable device without updating enable_cnt
1190  * @dev: PCI device to disable
1191  *
1192  * NOTE: This function is a backend of PCI power management routines and is
1193  * not supposed to be called drivers.
1194  */
1195 void pci_disable_enabled_device(struct pci_dev *dev)
1196 {
1197 	if (pci_is_enabled(dev))
1198 		do_pci_disable_device(dev);
1199 }
1200 
1201 /**
1202  * pci_disable_device - Disable PCI device after use
1203  * @dev: PCI device to be disabled
1204  *
1205  * Signal to the system that the PCI device is not in use by the system
1206  * anymore.  This only involves disabling PCI bus-mastering, if active.
1207  *
1208  * Note we don't actually disable the device until all callers of
1209  * pci_enable_device() have called pci_disable_device().
1210  */
1211 void
1212 pci_disable_device(struct pci_dev *dev)
1213 {
1214 	struct pci_devres *dr;
1215 
1216 	dr = find_pci_dr(dev);
1217 	if (dr)
1218 		dr->enabled = 0;
1219 
1220 	if (atomic_sub_return(1, &dev->enable_cnt) != 0)
1221 		return;
1222 
1223 	do_pci_disable_device(dev);
1224 
1225 	dev->is_busmaster = 0;
1226 }
1227 
1228 /**
1229  * pcibios_set_pcie_reset_state - set reset state for device dev
1230  * @dev: the PCIe device reset
1231  * @state: Reset state to enter into
1232  *
1233  *
1234  * Sets the PCIe reset state for the device. This is the default
1235  * implementation. Architecture implementations can override this.
1236  */
1237 int __attribute__ ((weak)) pcibios_set_pcie_reset_state(struct pci_dev *dev,
1238 							enum pcie_reset_state state)
1239 {
1240 	return -EINVAL;
1241 }
1242 
1243 /**
1244  * pci_set_pcie_reset_state - set reset state for device dev
1245  * @dev: the PCIe device reset
1246  * @state: Reset state to enter into
1247  *
1248  *
1249  * Sets the PCI reset state for the device.
1250  */
1251 int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state)
1252 {
1253 	return pcibios_set_pcie_reset_state(dev, state);
1254 }
1255 
1256 /**
1257  * pci_check_pme_status - Check if given device has generated PME.
1258  * @dev: Device to check.
1259  *
1260  * Check the PME status of the device and if set, clear it and clear PME enable
1261  * (if set).  Return 'true' if PME status and PME enable were both set or
1262  * 'false' otherwise.
1263  */
1264 bool pci_check_pme_status(struct pci_dev *dev)
1265 {
1266 	int pmcsr_pos;
1267 	u16 pmcsr;
1268 	bool ret = false;
1269 
1270 	if (!dev->pm_cap)
1271 		return false;
1272 
1273 	pmcsr_pos = dev->pm_cap + PCI_PM_CTRL;
1274 	pci_read_config_word(dev, pmcsr_pos, &pmcsr);
1275 	if (!(pmcsr & PCI_PM_CTRL_PME_STATUS))
1276 		return false;
1277 
1278 	/* Clear PME status. */
1279 	pmcsr |= PCI_PM_CTRL_PME_STATUS;
1280 	if (pmcsr & PCI_PM_CTRL_PME_ENABLE) {
1281 		/* Disable PME to avoid interrupt flood. */
1282 		pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
1283 		ret = true;
1284 	}
1285 
1286 	pci_write_config_word(dev, pmcsr_pos, pmcsr);
1287 
1288 	return ret;
1289 }
1290 
1291 /*
1292  * Time to wait before the system can be put into a sleep state after reporting
1293  * a wakeup event signaled by a PCI device.
1294  */
1295 #define PCI_WAKEUP_COOLDOWN	100
1296 
1297 /**
1298  * pci_wakeup_event - Report a wakeup event related to a given PCI device.
1299  * @dev: Device to report the wakeup event for.
1300  */
1301 void pci_wakeup_event(struct pci_dev *dev)
1302 {
1303 	if (device_may_wakeup(&dev->dev))
1304 		pm_wakeup_event(&dev->dev, PCI_WAKEUP_COOLDOWN);
1305 }
1306 
1307 /**
1308  * pci_pme_wakeup - Wake up a PCI device if its PME Status bit is set.
1309  * @dev: Device to handle.
1310  * @ign: Ignored.
1311  *
1312  * Check if @dev has generated PME and queue a resume request for it in that
1313  * case.
1314  */
1315 static int pci_pme_wakeup(struct pci_dev *dev, void *ign)
1316 {
1317 	if (pci_check_pme_status(dev)) {
1318 		pm_request_resume(&dev->dev);
1319 		pci_wakeup_event(dev);
1320 	}
1321 	return 0;
1322 }
1323 
1324 /**
1325  * pci_pme_wakeup_bus - Walk given bus and wake up devices on it, if necessary.
1326  * @bus: Top bus of the subtree to walk.
1327  */
1328 void pci_pme_wakeup_bus(struct pci_bus *bus)
1329 {
1330 	if (bus)
1331 		pci_walk_bus(bus, pci_pme_wakeup, NULL);
1332 }
1333 
1334 /**
1335  * pci_pme_capable - check the capability of PCI device to generate PME#
1336  * @dev: PCI device to handle.
1337  * @state: PCI state from which device will issue PME#.
1338  */
1339 bool pci_pme_capable(struct pci_dev *dev, pci_power_t state)
1340 {
1341 	if (!dev->pm_cap)
1342 		return false;
1343 
1344 	return !!(dev->pme_support & (1 << state));
1345 }
1346 
1347 static void pci_pme_list_scan(struct work_struct *work)
1348 {
1349 	struct pci_pme_device *pme_dev;
1350 
1351 	mutex_lock(&pci_pme_list_mutex);
1352 	if (!list_empty(&pci_pme_list)) {
1353 		list_for_each_entry(pme_dev, &pci_pme_list, list)
1354 			pci_pme_wakeup(pme_dev->dev, NULL);
1355 		schedule_delayed_work(&pci_pme_work, msecs_to_jiffies(PME_TIMEOUT));
1356 	}
1357 	mutex_unlock(&pci_pme_list_mutex);
1358 }
1359 
1360 /**
1361  * pci_external_pme - is a device an external PCI PME source?
1362  * @dev: PCI device to check
1363  *
1364  */
1365 
1366 static bool pci_external_pme(struct pci_dev *dev)
1367 {
1368 	if (pci_is_pcie(dev) || dev->bus->number == 0)
1369 		return false;
1370 	return true;
1371 }
1372 
1373 /**
1374  * pci_pme_active - enable or disable PCI device's PME# function
1375  * @dev: PCI device to handle.
1376  * @enable: 'true' to enable PME# generation; 'false' to disable it.
1377  *
1378  * The caller must verify that the device is capable of generating PME# before
1379  * calling this function with @enable equal to 'true'.
1380  */
1381 void pci_pme_active(struct pci_dev *dev, bool enable)
1382 {
1383 	u16 pmcsr;
1384 
1385 	if (!dev->pm_cap)
1386 		return;
1387 
1388 	pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
1389 	/* Clear PME_Status by writing 1 to it and enable PME# */
1390 	pmcsr |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE;
1391 	if (!enable)
1392 		pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
1393 
1394 	pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
1395 
1396 	/* PCI (as opposed to PCIe) PME requires that the device have
1397 	   its PME# line hooked up correctly. Not all hardware vendors
1398 	   do this, so the PME never gets delivered and the device
1399 	   remains asleep. The easiest way around this is to
1400 	   periodically walk the list of suspended devices and check
1401 	   whether any have their PME flag set. The assumption is that
1402 	   we'll wake up often enough anyway that this won't be a huge
1403 	   hit, and the power savings from the devices will still be a
1404 	   win. */
1405 
1406 	if (pci_external_pme(dev)) {
1407 		struct pci_pme_device *pme_dev;
1408 		if (enable) {
1409 			pme_dev = kmalloc(sizeof(struct pci_pme_device),
1410 					  GFP_KERNEL);
1411 			if (!pme_dev)
1412 				goto out;
1413 			pme_dev->dev = dev;
1414 			mutex_lock(&pci_pme_list_mutex);
1415 			list_add(&pme_dev->list, &pci_pme_list);
1416 			if (list_is_singular(&pci_pme_list))
1417 				schedule_delayed_work(&pci_pme_work,
1418 						      msecs_to_jiffies(PME_TIMEOUT));
1419 			mutex_unlock(&pci_pme_list_mutex);
1420 		} else {
1421 			mutex_lock(&pci_pme_list_mutex);
1422 			list_for_each_entry(pme_dev, &pci_pme_list, list) {
1423 				if (pme_dev->dev == dev) {
1424 					list_del(&pme_dev->list);
1425 					kfree(pme_dev);
1426 					break;
1427 				}
1428 			}
1429 			mutex_unlock(&pci_pme_list_mutex);
1430 		}
1431 	}
1432 
1433 out:
1434 	dev_printk(KERN_DEBUG, &dev->dev, "PME# %s\n",
1435 			enable ? "enabled" : "disabled");
1436 }
1437 
1438 /**
1439  * __pci_enable_wake - enable PCI device as wakeup event source
1440  * @dev: PCI device affected
1441  * @state: PCI state from which device will issue wakeup events
1442  * @runtime: True if the events are to be generated at run time
1443  * @enable: True to enable event generation; false to disable
1444  *
1445  * This enables the device as a wakeup event source, or disables it.
1446  * When such events involves platform-specific hooks, those hooks are
1447  * called automatically by this routine.
1448  *
1449  * Devices with legacy power management (no standard PCI PM capabilities)
1450  * always require such platform hooks.
1451  *
1452  * RETURN VALUE:
1453  * 0 is returned on success
1454  * -EINVAL is returned if device is not supposed to wake up the system
1455  * Error code depending on the platform is returned if both the platform and
1456  * the native mechanism fail to enable the generation of wake-up events
1457  */
1458 int __pci_enable_wake(struct pci_dev *dev, pci_power_t state,
1459 		      bool runtime, bool enable)
1460 {
1461 	int ret = 0;
1462 
1463 	if (enable && !runtime && !device_may_wakeup(&dev->dev))
1464 		return -EINVAL;
1465 
1466 	/* Don't do the same thing twice in a row for one device. */
1467 	if (!!enable == !!dev->wakeup_prepared)
1468 		return 0;
1469 
1470 	/*
1471 	 * According to "PCI System Architecture" 4th ed. by Tom Shanley & Don
1472 	 * Anderson we should be doing PME# wake enable followed by ACPI wake
1473 	 * enable.  To disable wake-up we call the platform first, for symmetry.
1474 	 */
1475 
1476 	if (enable) {
1477 		int error;
1478 
1479 		if (pci_pme_capable(dev, state))
1480 			pci_pme_active(dev, true);
1481 		else
1482 			ret = 1;
1483 		error = runtime ? platform_pci_run_wake(dev, true) :
1484 					platform_pci_sleep_wake(dev, true);
1485 		if (ret)
1486 			ret = error;
1487 		if (!ret)
1488 			dev->wakeup_prepared = true;
1489 	} else {
1490 		if (runtime)
1491 			platform_pci_run_wake(dev, false);
1492 		else
1493 			platform_pci_sleep_wake(dev, false);
1494 		pci_pme_active(dev, false);
1495 		dev->wakeup_prepared = false;
1496 	}
1497 
1498 	return ret;
1499 }
1500 EXPORT_SYMBOL(__pci_enable_wake);
1501 
1502 /**
1503  * pci_wake_from_d3 - enable/disable device to wake up from D3_hot or D3_cold
1504  * @dev: PCI device to prepare
1505  * @enable: True to enable wake-up event generation; false to disable
1506  *
1507  * Many drivers want the device to wake up the system from D3_hot or D3_cold
1508  * and this function allows them to set that up cleanly - pci_enable_wake()
1509  * should not be called twice in a row to enable wake-up due to PCI PM vs ACPI
1510  * ordering constraints.
1511  *
1512  * This function only returns error code if the device is not capable of
1513  * generating PME# from both D3_hot and D3_cold, and the platform is unable to
1514  * enable wake-up power for it.
1515  */
1516 int pci_wake_from_d3(struct pci_dev *dev, bool enable)
1517 {
1518 	return pci_pme_capable(dev, PCI_D3cold) ?
1519 			pci_enable_wake(dev, PCI_D3cold, enable) :
1520 			pci_enable_wake(dev, PCI_D3hot, enable);
1521 }
1522 
1523 /**
1524  * pci_target_state - find an appropriate low power state for a given PCI dev
1525  * @dev: PCI device
1526  *
1527  * Use underlying platform code to find a supported low power state for @dev.
1528  * If the platform can't manage @dev, return the deepest state from which it
1529  * can generate wake events, based on any available PME info.
1530  */
1531 pci_power_t pci_target_state(struct pci_dev *dev)
1532 {
1533 	pci_power_t target_state = PCI_D3hot;
1534 
1535 	if (platform_pci_power_manageable(dev)) {
1536 		/*
1537 		 * Call the platform to choose the target state of the device
1538 		 * and enable wake-up from this state if supported.
1539 		 */
1540 		pci_power_t state = platform_pci_choose_state(dev);
1541 
1542 		switch (state) {
1543 		case PCI_POWER_ERROR:
1544 		case PCI_UNKNOWN:
1545 			break;
1546 		case PCI_D1:
1547 		case PCI_D2:
1548 			if (pci_no_d1d2(dev))
1549 				break;
1550 		default:
1551 			target_state = state;
1552 		}
1553 	} else if (!dev->pm_cap) {
1554 		target_state = PCI_D0;
1555 	} else if (device_may_wakeup(&dev->dev)) {
1556 		/*
1557 		 * Find the deepest state from which the device can generate
1558 		 * wake-up events, make it the target state and enable device
1559 		 * to generate PME#.
1560 		 */
1561 		if (dev->pme_support) {
1562 			while (target_state
1563 			      && !(dev->pme_support & (1 << target_state)))
1564 				target_state--;
1565 		}
1566 	}
1567 
1568 	return target_state;
1569 }
1570 
1571 /**
1572  * pci_prepare_to_sleep - prepare PCI device for system-wide transition into a sleep state
1573  * @dev: Device to handle.
1574  *
1575  * Choose the power state appropriate for the device depending on whether
1576  * it can wake up the system and/or is power manageable by the platform
1577  * (PCI_D3hot is the default) and put the device into that state.
1578  */
1579 int pci_prepare_to_sleep(struct pci_dev *dev)
1580 {
1581 	pci_power_t target_state = pci_target_state(dev);
1582 	int error;
1583 
1584 	if (target_state == PCI_POWER_ERROR)
1585 		return -EIO;
1586 
1587 	pci_enable_wake(dev, target_state, device_may_wakeup(&dev->dev));
1588 
1589 	error = pci_set_power_state(dev, target_state);
1590 
1591 	if (error)
1592 		pci_enable_wake(dev, target_state, false);
1593 
1594 	return error;
1595 }
1596 
1597 /**
1598  * pci_back_from_sleep - turn PCI device on during system-wide transition into working state
1599  * @dev: Device to handle.
1600  *
1601  * Disable device's system wake-up capability and put it into D0.
1602  */
1603 int pci_back_from_sleep(struct pci_dev *dev)
1604 {
1605 	pci_enable_wake(dev, PCI_D0, false);
1606 	return pci_set_power_state(dev, PCI_D0);
1607 }
1608 
1609 /**
1610  * pci_finish_runtime_suspend - Carry out PCI-specific part of runtime suspend.
1611  * @dev: PCI device being suspended.
1612  *
1613  * Prepare @dev to generate wake-up events at run time and put it into a low
1614  * power state.
1615  */
1616 int pci_finish_runtime_suspend(struct pci_dev *dev)
1617 {
1618 	pci_power_t target_state = pci_target_state(dev);
1619 	int error;
1620 
1621 	if (target_state == PCI_POWER_ERROR)
1622 		return -EIO;
1623 
1624 	__pci_enable_wake(dev, target_state, true, pci_dev_run_wake(dev));
1625 
1626 	error = pci_set_power_state(dev, target_state);
1627 
1628 	if (error)
1629 		__pci_enable_wake(dev, target_state, true, false);
1630 
1631 	return error;
1632 }
1633 
1634 /**
1635  * pci_dev_run_wake - Check if device can generate run-time wake-up events.
1636  * @dev: Device to check.
1637  *
1638  * Return true if the device itself is cabable of generating wake-up events
1639  * (through the platform or using the native PCIe PME) or if the device supports
1640  * PME and one of its upstream bridges can generate wake-up events.
1641  */
1642 bool pci_dev_run_wake(struct pci_dev *dev)
1643 {
1644 	struct pci_bus *bus = dev->bus;
1645 
1646 	if (device_run_wake(&dev->dev))
1647 		return true;
1648 
1649 	if (!dev->pme_support)
1650 		return false;
1651 
1652 	while (bus->parent) {
1653 		struct pci_dev *bridge = bus->self;
1654 
1655 		if (device_run_wake(&bridge->dev))
1656 			return true;
1657 
1658 		bus = bus->parent;
1659 	}
1660 
1661 	/* We have reached the root bus. */
1662 	if (bus->bridge)
1663 		return device_run_wake(bus->bridge);
1664 
1665 	return false;
1666 }
1667 EXPORT_SYMBOL_GPL(pci_dev_run_wake);
1668 
1669 /**
1670  * pci_pm_init - Initialize PM functions of given PCI device
1671  * @dev: PCI device to handle.
1672  */
1673 void pci_pm_init(struct pci_dev *dev)
1674 {
1675 	int pm;
1676 	u16 pmc;
1677 
1678 	pm_runtime_forbid(&dev->dev);
1679 	device_enable_async_suspend(&dev->dev);
1680 	dev->wakeup_prepared = false;
1681 
1682 	dev->pm_cap = 0;
1683 
1684 	/* find PCI PM capability in list */
1685 	pm = pci_find_capability(dev, PCI_CAP_ID_PM);
1686 	if (!pm)
1687 		return;
1688 	/* Check device's ability to generate PME# */
1689 	pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
1690 
1691 	if ((pmc & PCI_PM_CAP_VER_MASK) > 3) {
1692 		dev_err(&dev->dev, "unsupported PM cap regs version (%u)\n",
1693 			pmc & PCI_PM_CAP_VER_MASK);
1694 		return;
1695 	}
1696 
1697 	dev->pm_cap = pm;
1698 	dev->d3_delay = PCI_PM_D3_WAIT;
1699 
1700 	dev->d1_support = false;
1701 	dev->d2_support = false;
1702 	if (!pci_no_d1d2(dev)) {
1703 		if (pmc & PCI_PM_CAP_D1)
1704 			dev->d1_support = true;
1705 		if (pmc & PCI_PM_CAP_D2)
1706 			dev->d2_support = true;
1707 
1708 		if (dev->d1_support || dev->d2_support)
1709 			dev_printk(KERN_DEBUG, &dev->dev, "supports%s%s\n",
1710 				   dev->d1_support ? " D1" : "",
1711 				   dev->d2_support ? " D2" : "");
1712 	}
1713 
1714 	pmc &= PCI_PM_CAP_PME_MASK;
1715 	if (pmc) {
1716 		dev_printk(KERN_DEBUG, &dev->dev,
1717 			 "PME# supported from%s%s%s%s%s\n",
1718 			 (pmc & PCI_PM_CAP_PME_D0) ? " D0" : "",
1719 			 (pmc & PCI_PM_CAP_PME_D1) ? " D1" : "",
1720 			 (pmc & PCI_PM_CAP_PME_D2) ? " D2" : "",
1721 			 (pmc & PCI_PM_CAP_PME_D3) ? " D3hot" : "",
1722 			 (pmc & PCI_PM_CAP_PME_D3cold) ? " D3cold" : "");
1723 		dev->pme_support = pmc >> PCI_PM_CAP_PME_SHIFT;
1724 		/*
1725 		 * Make device's PM flags reflect the wake-up capability, but
1726 		 * let the user space enable it to wake up the system as needed.
1727 		 */
1728 		device_set_wakeup_capable(&dev->dev, true);
1729 		/* Disable the PME# generation functionality */
1730 		pci_pme_active(dev, false);
1731 	} else {
1732 		dev->pme_support = 0;
1733 	}
1734 }
1735 
1736 /**
1737  * platform_pci_wakeup_init - init platform wakeup if present
1738  * @dev: PCI device
1739  *
1740  * Some devices don't have PCI PM caps but can still generate wakeup
1741  * events through platform methods (like ACPI events).  If @dev supports
1742  * platform wakeup events, set the device flag to indicate as much.  This
1743  * may be redundant if the device also supports PCI PM caps, but double
1744  * initialization should be safe in that case.
1745  */
1746 void platform_pci_wakeup_init(struct pci_dev *dev)
1747 {
1748 	if (!platform_pci_can_wakeup(dev))
1749 		return;
1750 
1751 	device_set_wakeup_capable(&dev->dev, true);
1752 	platform_pci_sleep_wake(dev, false);
1753 }
1754 
1755 /**
1756  * pci_add_save_buffer - allocate buffer for saving given capability registers
1757  * @dev: the PCI device
1758  * @cap: the capability to allocate the buffer for
1759  * @size: requested size of the buffer
1760  */
1761 static int pci_add_cap_save_buffer(
1762 	struct pci_dev *dev, char cap, unsigned int size)
1763 {
1764 	int pos;
1765 	struct pci_cap_saved_state *save_state;
1766 
1767 	pos = pci_find_capability(dev, cap);
1768 	if (pos <= 0)
1769 		return 0;
1770 
1771 	save_state = kzalloc(sizeof(*save_state) + size, GFP_KERNEL);
1772 	if (!save_state)
1773 		return -ENOMEM;
1774 
1775 	save_state->cap_nr = cap;
1776 	pci_add_saved_cap(dev, save_state);
1777 
1778 	return 0;
1779 }
1780 
1781 /**
1782  * pci_allocate_cap_save_buffers - allocate buffers for saving capabilities
1783  * @dev: the PCI device
1784  */
1785 void pci_allocate_cap_save_buffers(struct pci_dev *dev)
1786 {
1787 	int error;
1788 
1789 	error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_EXP,
1790 					PCI_EXP_SAVE_REGS * sizeof(u16));
1791 	if (error)
1792 		dev_err(&dev->dev,
1793 			"unable to preallocate PCI Express save buffer\n");
1794 
1795 	error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_PCIX, sizeof(u16));
1796 	if (error)
1797 		dev_err(&dev->dev,
1798 			"unable to preallocate PCI-X save buffer\n");
1799 }
1800 
1801 /**
1802  * pci_enable_ari - enable ARI forwarding if hardware support it
1803  * @dev: the PCI device
1804  */
1805 void pci_enable_ari(struct pci_dev *dev)
1806 {
1807 	int pos;
1808 	u32 cap;
1809 	u16 ctrl;
1810 	struct pci_dev *bridge;
1811 
1812 	if (!pci_is_pcie(dev) || dev->devfn)
1813 		return;
1814 
1815 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI);
1816 	if (!pos)
1817 		return;
1818 
1819 	bridge = dev->bus->self;
1820 	if (!bridge || !pci_is_pcie(bridge))
1821 		return;
1822 
1823 	pos = pci_pcie_cap(bridge);
1824 	if (!pos)
1825 		return;
1826 
1827 	pci_read_config_dword(bridge, pos + PCI_EXP_DEVCAP2, &cap);
1828 	if (!(cap & PCI_EXP_DEVCAP2_ARI))
1829 		return;
1830 
1831 	pci_read_config_word(bridge, pos + PCI_EXP_DEVCTL2, &ctrl);
1832 	ctrl |= PCI_EXP_DEVCTL2_ARI;
1833 	pci_write_config_word(bridge, pos + PCI_EXP_DEVCTL2, ctrl);
1834 
1835 	bridge->ari_enabled = 1;
1836 }
1837 
1838 static int pci_acs_enable;
1839 
1840 /**
1841  * pci_request_acs - ask for ACS to be enabled if supported
1842  */
1843 void pci_request_acs(void)
1844 {
1845 	pci_acs_enable = 1;
1846 }
1847 
1848 /**
1849  * pci_enable_acs - enable ACS if hardware support it
1850  * @dev: the PCI device
1851  */
1852 void pci_enable_acs(struct pci_dev *dev)
1853 {
1854 	int pos;
1855 	u16 cap;
1856 	u16 ctrl;
1857 
1858 	if (!pci_acs_enable)
1859 		return;
1860 
1861 	if (!pci_is_pcie(dev))
1862 		return;
1863 
1864 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS);
1865 	if (!pos)
1866 		return;
1867 
1868 	pci_read_config_word(dev, pos + PCI_ACS_CAP, &cap);
1869 	pci_read_config_word(dev, pos + PCI_ACS_CTRL, &ctrl);
1870 
1871 	/* Source Validation */
1872 	ctrl |= (cap & PCI_ACS_SV);
1873 
1874 	/* P2P Request Redirect */
1875 	ctrl |= (cap & PCI_ACS_RR);
1876 
1877 	/* P2P Completion Redirect */
1878 	ctrl |= (cap & PCI_ACS_CR);
1879 
1880 	/* Upstream Forwarding */
1881 	ctrl |= (cap & PCI_ACS_UF);
1882 
1883 	pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl);
1884 }
1885 
1886 /**
1887  * pci_swizzle_interrupt_pin - swizzle INTx for device behind bridge
1888  * @dev: the PCI device
1889  * @pin: the INTx pin (1=INTA, 2=INTB, 3=INTD, 4=INTD)
1890  *
1891  * Perform INTx swizzling for a device behind one level of bridge.  This is
1892  * required by section 9.1 of the PCI-to-PCI bridge specification for devices
1893  * behind bridges on add-in cards.  For devices with ARI enabled, the slot
1894  * number is always 0 (see the Implementation Note in section 2.2.8.1 of
1895  * the PCI Express Base Specification, Revision 2.1)
1896  */
1897 u8 pci_swizzle_interrupt_pin(struct pci_dev *dev, u8 pin)
1898 {
1899 	int slot;
1900 
1901 	if (pci_ari_enabled(dev->bus))
1902 		slot = 0;
1903 	else
1904 		slot = PCI_SLOT(dev->devfn);
1905 
1906 	return (((pin - 1) + slot) % 4) + 1;
1907 }
1908 
1909 int
1910 pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge)
1911 {
1912 	u8 pin;
1913 
1914 	pin = dev->pin;
1915 	if (!pin)
1916 		return -1;
1917 
1918 	while (!pci_is_root_bus(dev->bus)) {
1919 		pin = pci_swizzle_interrupt_pin(dev, pin);
1920 		dev = dev->bus->self;
1921 	}
1922 	*bridge = dev;
1923 	return pin;
1924 }
1925 
1926 /**
1927  * pci_common_swizzle - swizzle INTx all the way to root bridge
1928  * @dev: the PCI device
1929  * @pinp: pointer to the INTx pin value (1=INTA, 2=INTB, 3=INTD, 4=INTD)
1930  *
1931  * Perform INTx swizzling for a device.  This traverses through all PCI-to-PCI
1932  * bridges all the way up to a PCI root bus.
1933  */
1934 u8 pci_common_swizzle(struct pci_dev *dev, u8 *pinp)
1935 {
1936 	u8 pin = *pinp;
1937 
1938 	while (!pci_is_root_bus(dev->bus)) {
1939 		pin = pci_swizzle_interrupt_pin(dev, pin);
1940 		dev = dev->bus->self;
1941 	}
1942 	*pinp = pin;
1943 	return PCI_SLOT(dev->devfn);
1944 }
1945 
1946 /**
1947  *	pci_release_region - Release a PCI bar
1948  *	@pdev: PCI device whose resources were previously reserved by pci_request_region
1949  *	@bar: BAR to release
1950  *
1951  *	Releases the PCI I/O and memory resources previously reserved by a
1952  *	successful call to pci_request_region.  Call this function only
1953  *	after all use of the PCI regions has ceased.
1954  */
1955 void pci_release_region(struct pci_dev *pdev, int bar)
1956 {
1957 	struct pci_devres *dr;
1958 
1959 	if (pci_resource_len(pdev, bar) == 0)
1960 		return;
1961 	if (pci_resource_flags(pdev, bar) & IORESOURCE_IO)
1962 		release_region(pci_resource_start(pdev, bar),
1963 				pci_resource_len(pdev, bar));
1964 	else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM)
1965 		release_mem_region(pci_resource_start(pdev, bar),
1966 				pci_resource_len(pdev, bar));
1967 
1968 	dr = find_pci_dr(pdev);
1969 	if (dr)
1970 		dr->region_mask &= ~(1 << bar);
1971 }
1972 
1973 /**
1974  *	__pci_request_region - Reserved PCI I/O and memory resource
1975  *	@pdev: PCI device whose resources are to be reserved
1976  *	@bar: BAR to be reserved
1977  *	@res_name: Name to be associated with resource.
1978  *	@exclusive: whether the region access is exclusive or not
1979  *
1980  *	Mark the PCI region associated with PCI device @pdev BR @bar as
1981  *	being reserved by owner @res_name.  Do not access any
1982  *	address inside the PCI regions unless this call returns
1983  *	successfully.
1984  *
1985  *	If @exclusive is set, then the region is marked so that userspace
1986  *	is explicitly not allowed to map the resource via /dev/mem or
1987  * 	sysfs MMIO access.
1988  *
1989  *	Returns 0 on success, or %EBUSY on error.  A warning
1990  *	message is also printed on failure.
1991  */
1992 static int __pci_request_region(struct pci_dev *pdev, int bar, const char *res_name,
1993 									int exclusive)
1994 {
1995 	struct pci_devres *dr;
1996 
1997 	if (pci_resource_len(pdev, bar) == 0)
1998 		return 0;
1999 
2000 	if (pci_resource_flags(pdev, bar) & IORESOURCE_IO) {
2001 		if (!request_region(pci_resource_start(pdev, bar),
2002 			    pci_resource_len(pdev, bar), res_name))
2003 			goto err_out;
2004 	}
2005 	else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM) {
2006 		if (!__request_mem_region(pci_resource_start(pdev, bar),
2007 					pci_resource_len(pdev, bar), res_name,
2008 					exclusive))
2009 			goto err_out;
2010 	}
2011 
2012 	dr = find_pci_dr(pdev);
2013 	if (dr)
2014 		dr->region_mask |= 1 << bar;
2015 
2016 	return 0;
2017 
2018 err_out:
2019 	dev_warn(&pdev->dev, "BAR %d: can't reserve %pR\n", bar,
2020 		 &pdev->resource[bar]);
2021 	return -EBUSY;
2022 }
2023 
2024 /**
2025  *	pci_request_region - Reserve PCI I/O and memory resource
2026  *	@pdev: PCI device whose resources are to be reserved
2027  *	@bar: BAR to be reserved
2028  *	@res_name: Name to be associated with resource
2029  *
2030  *	Mark the PCI region associated with PCI device @pdev BAR @bar as
2031  *	being reserved by owner @res_name.  Do not access any
2032  *	address inside the PCI regions unless this call returns
2033  *	successfully.
2034  *
2035  *	Returns 0 on success, or %EBUSY on error.  A warning
2036  *	message is also printed on failure.
2037  */
2038 int pci_request_region(struct pci_dev *pdev, int bar, const char *res_name)
2039 {
2040 	return __pci_request_region(pdev, bar, res_name, 0);
2041 }
2042 
2043 /**
2044  *	pci_request_region_exclusive - Reserved PCI I/O and memory resource
2045  *	@pdev: PCI device whose resources are to be reserved
2046  *	@bar: BAR to be reserved
2047  *	@res_name: Name to be associated with resource.
2048  *
2049  *	Mark the PCI region associated with PCI device @pdev BR @bar as
2050  *	being reserved by owner @res_name.  Do not access any
2051  *	address inside the PCI regions unless this call returns
2052  *	successfully.
2053  *
2054  *	Returns 0 on success, or %EBUSY on error.  A warning
2055  *	message is also printed on failure.
2056  *
2057  *	The key difference that _exclusive makes it that userspace is
2058  *	explicitly not allowed to map the resource via /dev/mem or
2059  * 	sysfs.
2060  */
2061 int pci_request_region_exclusive(struct pci_dev *pdev, int bar, const char *res_name)
2062 {
2063 	return __pci_request_region(pdev, bar, res_name, IORESOURCE_EXCLUSIVE);
2064 }
2065 /**
2066  * pci_release_selected_regions - Release selected PCI I/O and memory resources
2067  * @pdev: PCI device whose resources were previously reserved
2068  * @bars: Bitmask of BARs to be released
2069  *
2070  * Release selected PCI I/O and memory resources previously reserved.
2071  * Call this function only after all use of the PCI regions has ceased.
2072  */
2073 void pci_release_selected_regions(struct pci_dev *pdev, int bars)
2074 {
2075 	int i;
2076 
2077 	for (i = 0; i < 6; i++)
2078 		if (bars & (1 << i))
2079 			pci_release_region(pdev, i);
2080 }
2081 
2082 int __pci_request_selected_regions(struct pci_dev *pdev, int bars,
2083 				 const char *res_name, int excl)
2084 {
2085 	int i;
2086 
2087 	for (i = 0; i < 6; i++)
2088 		if (bars & (1 << i))
2089 			if (__pci_request_region(pdev, i, res_name, excl))
2090 				goto err_out;
2091 	return 0;
2092 
2093 err_out:
2094 	while(--i >= 0)
2095 		if (bars & (1 << i))
2096 			pci_release_region(pdev, i);
2097 
2098 	return -EBUSY;
2099 }
2100 
2101 
2102 /**
2103  * pci_request_selected_regions - Reserve selected PCI I/O and memory resources
2104  * @pdev: PCI device whose resources are to be reserved
2105  * @bars: Bitmask of BARs to be requested
2106  * @res_name: Name to be associated with resource
2107  */
2108 int pci_request_selected_regions(struct pci_dev *pdev, int bars,
2109 				 const char *res_name)
2110 {
2111 	return __pci_request_selected_regions(pdev, bars, res_name, 0);
2112 }
2113 
2114 int pci_request_selected_regions_exclusive(struct pci_dev *pdev,
2115 				 int bars, const char *res_name)
2116 {
2117 	return __pci_request_selected_regions(pdev, bars, res_name,
2118 			IORESOURCE_EXCLUSIVE);
2119 }
2120 
2121 /**
2122  *	pci_release_regions - Release reserved PCI I/O and memory resources
2123  *	@pdev: PCI device whose resources were previously reserved by pci_request_regions
2124  *
2125  *	Releases all PCI I/O and memory resources previously reserved by a
2126  *	successful call to pci_request_regions.  Call this function only
2127  *	after all use of the PCI regions has ceased.
2128  */
2129 
2130 void pci_release_regions(struct pci_dev *pdev)
2131 {
2132 	pci_release_selected_regions(pdev, (1 << 6) - 1);
2133 }
2134 
2135 /**
2136  *	pci_request_regions - Reserved PCI I/O and memory resources
2137  *	@pdev: PCI device whose resources are to be reserved
2138  *	@res_name: Name to be associated with resource.
2139  *
2140  *	Mark all PCI regions associated with PCI device @pdev as
2141  *	being reserved by owner @res_name.  Do not access any
2142  *	address inside the PCI regions unless this call returns
2143  *	successfully.
2144  *
2145  *	Returns 0 on success, or %EBUSY on error.  A warning
2146  *	message is also printed on failure.
2147  */
2148 int pci_request_regions(struct pci_dev *pdev, const char *res_name)
2149 {
2150 	return pci_request_selected_regions(pdev, ((1 << 6) - 1), res_name);
2151 }
2152 
2153 /**
2154  *	pci_request_regions_exclusive - Reserved PCI I/O and memory resources
2155  *	@pdev: PCI device whose resources are to be reserved
2156  *	@res_name: Name to be associated with resource.
2157  *
2158  *	Mark all PCI regions associated with PCI device @pdev as
2159  *	being reserved by owner @res_name.  Do not access any
2160  *	address inside the PCI regions unless this call returns
2161  *	successfully.
2162  *
2163  *	pci_request_regions_exclusive() will mark the region so that
2164  * 	/dev/mem and the sysfs MMIO access will not be allowed.
2165  *
2166  *	Returns 0 on success, or %EBUSY on error.  A warning
2167  *	message is also printed on failure.
2168  */
2169 int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name)
2170 {
2171 	return pci_request_selected_regions_exclusive(pdev,
2172 					((1 << 6) - 1), res_name);
2173 }
2174 
2175 static void __pci_set_master(struct pci_dev *dev, bool enable)
2176 {
2177 	u16 old_cmd, cmd;
2178 
2179 	pci_read_config_word(dev, PCI_COMMAND, &old_cmd);
2180 	if (enable)
2181 		cmd = old_cmd | PCI_COMMAND_MASTER;
2182 	else
2183 		cmd = old_cmd & ~PCI_COMMAND_MASTER;
2184 	if (cmd != old_cmd) {
2185 		dev_dbg(&dev->dev, "%s bus mastering\n",
2186 			enable ? "enabling" : "disabling");
2187 		pci_write_config_word(dev, PCI_COMMAND, cmd);
2188 	}
2189 	dev->is_busmaster = enable;
2190 }
2191 
2192 /**
2193  * pci_set_master - enables bus-mastering for device dev
2194  * @dev: the PCI device to enable
2195  *
2196  * Enables bus-mastering on the device and calls pcibios_set_master()
2197  * to do the needed arch specific settings.
2198  */
2199 void pci_set_master(struct pci_dev *dev)
2200 {
2201 	__pci_set_master(dev, true);
2202 	pcibios_set_master(dev);
2203 }
2204 
2205 /**
2206  * pci_clear_master - disables bus-mastering for device dev
2207  * @dev: the PCI device to disable
2208  */
2209 void pci_clear_master(struct pci_dev *dev)
2210 {
2211 	__pci_set_master(dev, false);
2212 }
2213 
2214 /**
2215  * pci_set_cacheline_size - ensure the CACHE_LINE_SIZE register is programmed
2216  * @dev: the PCI device for which MWI is to be enabled
2217  *
2218  * Helper function for pci_set_mwi.
2219  * Originally copied from drivers/net/acenic.c.
2220  * Copyright 1998-2001 by Jes Sorensen, <jes@trained-monkey.org>.
2221  *
2222  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2223  */
2224 int pci_set_cacheline_size(struct pci_dev *dev)
2225 {
2226 	u8 cacheline_size;
2227 
2228 	if (!pci_cache_line_size)
2229 		return -EINVAL;
2230 
2231 	/* Validate current setting: the PCI_CACHE_LINE_SIZE must be
2232 	   equal to or multiple of the right value. */
2233 	pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
2234 	if (cacheline_size >= pci_cache_line_size &&
2235 	    (cacheline_size % pci_cache_line_size) == 0)
2236 		return 0;
2237 
2238 	/* Write the correct value. */
2239 	pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, pci_cache_line_size);
2240 	/* Read it back. */
2241 	pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
2242 	if (cacheline_size == pci_cache_line_size)
2243 		return 0;
2244 
2245 	dev_printk(KERN_DEBUG, &dev->dev, "cache line size of %d is not "
2246 		   "supported\n", pci_cache_line_size << 2);
2247 
2248 	return -EINVAL;
2249 }
2250 EXPORT_SYMBOL_GPL(pci_set_cacheline_size);
2251 
2252 #ifdef PCI_DISABLE_MWI
2253 int pci_set_mwi(struct pci_dev *dev)
2254 {
2255 	return 0;
2256 }
2257 
2258 int pci_try_set_mwi(struct pci_dev *dev)
2259 {
2260 	return 0;
2261 }
2262 
2263 void pci_clear_mwi(struct pci_dev *dev)
2264 {
2265 }
2266 
2267 #else
2268 
2269 /**
2270  * pci_set_mwi - enables memory-write-invalidate PCI transaction
2271  * @dev: the PCI device for which MWI is enabled
2272  *
2273  * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND.
2274  *
2275  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2276  */
2277 int
2278 pci_set_mwi(struct pci_dev *dev)
2279 {
2280 	int rc;
2281 	u16 cmd;
2282 
2283 	rc = pci_set_cacheline_size(dev);
2284 	if (rc)
2285 		return rc;
2286 
2287 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
2288 	if (! (cmd & PCI_COMMAND_INVALIDATE)) {
2289 		dev_dbg(&dev->dev, "enabling Mem-Wr-Inval\n");
2290 		cmd |= PCI_COMMAND_INVALIDATE;
2291 		pci_write_config_word(dev, PCI_COMMAND, cmd);
2292 	}
2293 
2294 	return 0;
2295 }
2296 
2297 /**
2298  * pci_try_set_mwi - enables memory-write-invalidate PCI transaction
2299  * @dev: the PCI device for which MWI is enabled
2300  *
2301  * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND.
2302  * Callers are not required to check the return value.
2303  *
2304  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2305  */
2306 int pci_try_set_mwi(struct pci_dev *dev)
2307 {
2308 	int rc = pci_set_mwi(dev);
2309 	return rc;
2310 }
2311 
2312 /**
2313  * pci_clear_mwi - disables Memory-Write-Invalidate for device dev
2314  * @dev: the PCI device to disable
2315  *
2316  * Disables PCI Memory-Write-Invalidate transaction on the device
2317  */
2318 void
2319 pci_clear_mwi(struct pci_dev *dev)
2320 {
2321 	u16 cmd;
2322 
2323 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
2324 	if (cmd & PCI_COMMAND_INVALIDATE) {
2325 		cmd &= ~PCI_COMMAND_INVALIDATE;
2326 		pci_write_config_word(dev, PCI_COMMAND, cmd);
2327 	}
2328 }
2329 #endif /* ! PCI_DISABLE_MWI */
2330 
2331 /**
2332  * pci_intx - enables/disables PCI INTx for device dev
2333  * @pdev: the PCI device to operate on
2334  * @enable: boolean: whether to enable or disable PCI INTx
2335  *
2336  * Enables/disables PCI INTx for device dev
2337  */
2338 void
2339 pci_intx(struct pci_dev *pdev, int enable)
2340 {
2341 	u16 pci_command, new;
2342 
2343 	pci_read_config_word(pdev, PCI_COMMAND, &pci_command);
2344 
2345 	if (enable) {
2346 		new = pci_command & ~PCI_COMMAND_INTX_DISABLE;
2347 	} else {
2348 		new = pci_command | PCI_COMMAND_INTX_DISABLE;
2349 	}
2350 
2351 	if (new != pci_command) {
2352 		struct pci_devres *dr;
2353 
2354 		pci_write_config_word(pdev, PCI_COMMAND, new);
2355 
2356 		dr = find_pci_dr(pdev);
2357 		if (dr && !dr->restore_intx) {
2358 			dr->restore_intx = 1;
2359 			dr->orig_intx = !enable;
2360 		}
2361 	}
2362 }
2363 
2364 /**
2365  * pci_msi_off - disables any msi or msix capabilities
2366  * @dev: the PCI device to operate on
2367  *
2368  * If you want to use msi see pci_enable_msi and friends.
2369  * This is a lower level primitive that allows us to disable
2370  * msi operation at the device level.
2371  */
2372 void pci_msi_off(struct pci_dev *dev)
2373 {
2374 	int pos;
2375 	u16 control;
2376 
2377 	pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
2378 	if (pos) {
2379 		pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control);
2380 		control &= ~PCI_MSI_FLAGS_ENABLE;
2381 		pci_write_config_word(dev, pos + PCI_MSI_FLAGS, control);
2382 	}
2383 	pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
2384 	if (pos) {
2385 		pci_read_config_word(dev, pos + PCI_MSIX_FLAGS, &control);
2386 		control &= ~PCI_MSIX_FLAGS_ENABLE;
2387 		pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control);
2388 	}
2389 }
2390 EXPORT_SYMBOL_GPL(pci_msi_off);
2391 
2392 int pci_set_dma_max_seg_size(struct pci_dev *dev, unsigned int size)
2393 {
2394 	return dma_set_max_seg_size(&dev->dev, size);
2395 }
2396 EXPORT_SYMBOL(pci_set_dma_max_seg_size);
2397 
2398 int pci_set_dma_seg_boundary(struct pci_dev *dev, unsigned long mask)
2399 {
2400 	return dma_set_seg_boundary(&dev->dev, mask);
2401 }
2402 EXPORT_SYMBOL(pci_set_dma_seg_boundary);
2403 
2404 static int pcie_flr(struct pci_dev *dev, int probe)
2405 {
2406 	int i;
2407 	int pos;
2408 	u32 cap;
2409 	u16 status, control;
2410 
2411 	pos = pci_pcie_cap(dev);
2412 	if (!pos)
2413 		return -ENOTTY;
2414 
2415 	pci_read_config_dword(dev, pos + PCI_EXP_DEVCAP, &cap);
2416 	if (!(cap & PCI_EXP_DEVCAP_FLR))
2417 		return -ENOTTY;
2418 
2419 	if (probe)
2420 		return 0;
2421 
2422 	/* Wait for Transaction Pending bit clean */
2423 	for (i = 0; i < 4; i++) {
2424 		if (i)
2425 			msleep((1 << (i - 1)) * 100);
2426 
2427 		pci_read_config_word(dev, pos + PCI_EXP_DEVSTA, &status);
2428 		if (!(status & PCI_EXP_DEVSTA_TRPND))
2429 			goto clear;
2430 	}
2431 
2432 	dev_err(&dev->dev, "transaction is not cleared; "
2433 			"proceeding with reset anyway\n");
2434 
2435 clear:
2436 	pci_read_config_word(dev, pos + PCI_EXP_DEVCTL, &control);
2437 	control |= PCI_EXP_DEVCTL_BCR_FLR;
2438 	pci_write_config_word(dev, pos + PCI_EXP_DEVCTL, control);
2439 
2440 	msleep(100);
2441 
2442 	return 0;
2443 }
2444 
2445 static int pci_af_flr(struct pci_dev *dev, int probe)
2446 {
2447 	int i;
2448 	int pos;
2449 	u8 cap;
2450 	u8 status;
2451 
2452 	pos = pci_find_capability(dev, PCI_CAP_ID_AF);
2453 	if (!pos)
2454 		return -ENOTTY;
2455 
2456 	pci_read_config_byte(dev, pos + PCI_AF_CAP, &cap);
2457 	if (!(cap & PCI_AF_CAP_TP) || !(cap & PCI_AF_CAP_FLR))
2458 		return -ENOTTY;
2459 
2460 	if (probe)
2461 		return 0;
2462 
2463 	/* Wait for Transaction Pending bit clean */
2464 	for (i = 0; i < 4; i++) {
2465 		if (i)
2466 			msleep((1 << (i - 1)) * 100);
2467 
2468 		pci_read_config_byte(dev, pos + PCI_AF_STATUS, &status);
2469 		if (!(status & PCI_AF_STATUS_TP))
2470 			goto clear;
2471 	}
2472 
2473 	dev_err(&dev->dev, "transaction is not cleared; "
2474 			"proceeding with reset anyway\n");
2475 
2476 clear:
2477 	pci_write_config_byte(dev, pos + PCI_AF_CTRL, PCI_AF_CTRL_FLR);
2478 	msleep(100);
2479 
2480 	return 0;
2481 }
2482 
2483 static int pci_pm_reset(struct pci_dev *dev, int probe)
2484 {
2485 	u16 csr;
2486 
2487 	if (!dev->pm_cap)
2488 		return -ENOTTY;
2489 
2490 	pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &csr);
2491 	if (csr & PCI_PM_CTRL_NO_SOFT_RESET)
2492 		return -ENOTTY;
2493 
2494 	if (probe)
2495 		return 0;
2496 
2497 	if (dev->current_state != PCI_D0)
2498 		return -EINVAL;
2499 
2500 	csr &= ~PCI_PM_CTRL_STATE_MASK;
2501 	csr |= PCI_D3hot;
2502 	pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);
2503 	pci_dev_d3_sleep(dev);
2504 
2505 	csr &= ~PCI_PM_CTRL_STATE_MASK;
2506 	csr |= PCI_D0;
2507 	pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);
2508 	pci_dev_d3_sleep(dev);
2509 
2510 	return 0;
2511 }
2512 
2513 static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
2514 {
2515 	u16 ctrl;
2516 	struct pci_dev *pdev;
2517 
2518 	if (pci_is_root_bus(dev->bus) || dev->subordinate || !dev->bus->self)
2519 		return -ENOTTY;
2520 
2521 	list_for_each_entry(pdev, &dev->bus->devices, bus_list)
2522 		if (pdev != dev)
2523 			return -ENOTTY;
2524 
2525 	if (probe)
2526 		return 0;
2527 
2528 	pci_read_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, &ctrl);
2529 	ctrl |= PCI_BRIDGE_CTL_BUS_RESET;
2530 	pci_write_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, ctrl);
2531 	msleep(100);
2532 
2533 	ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET;
2534 	pci_write_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, ctrl);
2535 	msleep(100);
2536 
2537 	return 0;
2538 }
2539 
2540 static int pci_dev_reset(struct pci_dev *dev, int probe)
2541 {
2542 	int rc;
2543 
2544 	might_sleep();
2545 
2546 	if (!probe) {
2547 		pci_block_user_cfg_access(dev);
2548 		/* block PM suspend, driver probe, etc. */
2549 		device_lock(&dev->dev);
2550 	}
2551 
2552 	rc = pci_dev_specific_reset(dev, probe);
2553 	if (rc != -ENOTTY)
2554 		goto done;
2555 
2556 	rc = pcie_flr(dev, probe);
2557 	if (rc != -ENOTTY)
2558 		goto done;
2559 
2560 	rc = pci_af_flr(dev, probe);
2561 	if (rc != -ENOTTY)
2562 		goto done;
2563 
2564 	rc = pci_pm_reset(dev, probe);
2565 	if (rc != -ENOTTY)
2566 		goto done;
2567 
2568 	rc = pci_parent_bus_reset(dev, probe);
2569 done:
2570 	if (!probe) {
2571 		device_unlock(&dev->dev);
2572 		pci_unblock_user_cfg_access(dev);
2573 	}
2574 
2575 	return rc;
2576 }
2577 
2578 /**
2579  * __pci_reset_function - reset a PCI device function
2580  * @dev: PCI device to reset
2581  *
2582  * Some devices allow an individual function to be reset without affecting
2583  * other functions in the same device.  The PCI device must be responsive
2584  * to PCI config space in order to use this function.
2585  *
2586  * The device function is presumed to be unused when this function is called.
2587  * Resetting the device will make the contents of PCI configuration space
2588  * random, so any caller of this must be prepared to reinitialise the
2589  * device including MSI, bus mastering, BARs, decoding IO and memory spaces,
2590  * etc.
2591  *
2592  * Returns 0 if the device function was successfully reset or negative if the
2593  * device doesn't support resetting a single function.
2594  */
2595 int __pci_reset_function(struct pci_dev *dev)
2596 {
2597 	return pci_dev_reset(dev, 0);
2598 }
2599 EXPORT_SYMBOL_GPL(__pci_reset_function);
2600 
2601 /**
2602  * pci_probe_reset_function - check whether the device can be safely reset
2603  * @dev: PCI device to reset
2604  *
2605  * Some devices allow an individual function to be reset without affecting
2606  * other functions in the same device.  The PCI device must be responsive
2607  * to PCI config space in order to use this function.
2608  *
2609  * Returns 0 if the device function can be reset or negative if the
2610  * device doesn't support resetting a single function.
2611  */
2612 int pci_probe_reset_function(struct pci_dev *dev)
2613 {
2614 	return pci_dev_reset(dev, 1);
2615 }
2616 
2617 /**
2618  * pci_reset_function - quiesce and reset a PCI device function
2619  * @dev: PCI device to reset
2620  *
2621  * Some devices allow an individual function to be reset without affecting
2622  * other functions in the same device.  The PCI device must be responsive
2623  * to PCI config space in order to use this function.
2624  *
2625  * This function does not just reset the PCI portion of a device, but
2626  * clears all the state associated with the device.  This function differs
2627  * from __pci_reset_function in that it saves and restores device state
2628  * over the reset.
2629  *
2630  * Returns 0 if the device function was successfully reset or negative if the
2631  * device doesn't support resetting a single function.
2632  */
2633 int pci_reset_function(struct pci_dev *dev)
2634 {
2635 	int rc;
2636 
2637 	rc = pci_dev_reset(dev, 1);
2638 	if (rc)
2639 		return rc;
2640 
2641 	pci_save_state(dev);
2642 
2643 	/*
2644 	 * both INTx and MSI are disabled after the Interrupt Disable bit
2645 	 * is set and the Bus Master bit is cleared.
2646 	 */
2647 	pci_write_config_word(dev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
2648 
2649 	rc = pci_dev_reset(dev, 0);
2650 
2651 	pci_restore_state(dev);
2652 
2653 	return rc;
2654 }
2655 EXPORT_SYMBOL_GPL(pci_reset_function);
2656 
2657 /**
2658  * pcix_get_max_mmrbc - get PCI-X maximum designed memory read byte count
2659  * @dev: PCI device to query
2660  *
2661  * Returns mmrbc: maximum designed memory read count in bytes
2662  *    or appropriate error value.
2663  */
2664 int pcix_get_max_mmrbc(struct pci_dev *dev)
2665 {
2666 	int cap;
2667 	u32 stat;
2668 
2669 	cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
2670 	if (!cap)
2671 		return -EINVAL;
2672 
2673 	if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat))
2674 		return -EINVAL;
2675 
2676 	return 512 << ((stat & PCI_X_STATUS_MAX_READ) >> 21);
2677 }
2678 EXPORT_SYMBOL(pcix_get_max_mmrbc);
2679 
2680 /**
2681  * pcix_get_mmrbc - get PCI-X maximum memory read byte count
2682  * @dev: PCI device to query
2683  *
2684  * Returns mmrbc: maximum memory read count in bytes
2685  *    or appropriate error value.
2686  */
2687 int pcix_get_mmrbc(struct pci_dev *dev)
2688 {
2689 	int cap;
2690 	u16 cmd;
2691 
2692 	cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
2693 	if (!cap)
2694 		return -EINVAL;
2695 
2696 	if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd))
2697 		return -EINVAL;
2698 
2699 	return 512 << ((cmd & PCI_X_CMD_MAX_READ) >> 2);
2700 }
2701 EXPORT_SYMBOL(pcix_get_mmrbc);
2702 
2703 /**
2704  * pcix_set_mmrbc - set PCI-X maximum memory read byte count
2705  * @dev: PCI device to query
2706  * @mmrbc: maximum memory read count in bytes
2707  *    valid values are 512, 1024, 2048, 4096
2708  *
2709  * If possible sets maximum memory read byte count, some bridges have erratas
2710  * that prevent this.
2711  */
2712 int pcix_set_mmrbc(struct pci_dev *dev, int mmrbc)
2713 {
2714 	int cap;
2715 	u32 stat, v, o;
2716 	u16 cmd;
2717 
2718 	if (mmrbc < 512 || mmrbc > 4096 || !is_power_of_2(mmrbc))
2719 		return -EINVAL;
2720 
2721 	v = ffs(mmrbc) - 10;
2722 
2723 	cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
2724 	if (!cap)
2725 		return -EINVAL;
2726 
2727 	if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat))
2728 		return -EINVAL;
2729 
2730 	if (v > (stat & PCI_X_STATUS_MAX_READ) >> 21)
2731 		return -E2BIG;
2732 
2733 	if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd))
2734 		return -EINVAL;
2735 
2736 	o = (cmd & PCI_X_CMD_MAX_READ) >> 2;
2737 	if (o != v) {
2738 		if (v > o && dev->bus &&
2739 		   (dev->bus->bus_flags & PCI_BUS_FLAGS_NO_MMRBC))
2740 			return -EIO;
2741 
2742 		cmd &= ~PCI_X_CMD_MAX_READ;
2743 		cmd |= v << 2;
2744 		if (pci_write_config_word(dev, cap + PCI_X_CMD, cmd))
2745 			return -EIO;
2746 	}
2747 	return 0;
2748 }
2749 EXPORT_SYMBOL(pcix_set_mmrbc);
2750 
2751 /**
2752  * pcie_get_readrq - get PCI Express read request size
2753  * @dev: PCI device to query
2754  *
2755  * Returns maximum memory read request in bytes
2756  *    or appropriate error value.
2757  */
2758 int pcie_get_readrq(struct pci_dev *dev)
2759 {
2760 	int ret, cap;
2761 	u16 ctl;
2762 
2763 	cap = pci_pcie_cap(dev);
2764 	if (!cap)
2765 		return -EINVAL;
2766 
2767 	ret = pci_read_config_word(dev, cap + PCI_EXP_DEVCTL, &ctl);
2768 	if (!ret)
2769 		ret = 128 << ((ctl & PCI_EXP_DEVCTL_READRQ) >> 12);
2770 
2771 	return ret;
2772 }
2773 EXPORT_SYMBOL(pcie_get_readrq);
2774 
2775 /**
2776  * pcie_set_readrq - set PCI Express maximum memory read request
2777  * @dev: PCI device to query
2778  * @rq: maximum memory read count in bytes
2779  *    valid values are 128, 256, 512, 1024, 2048, 4096
2780  *
2781  * If possible sets maximum read byte count
2782  */
2783 int pcie_set_readrq(struct pci_dev *dev, int rq)
2784 {
2785 	int cap, err = -EINVAL;
2786 	u16 ctl, v;
2787 
2788 	if (rq < 128 || rq > 4096 || !is_power_of_2(rq))
2789 		goto out;
2790 
2791 	v = (ffs(rq) - 8) << 12;
2792 
2793 	cap = pci_pcie_cap(dev);
2794 	if (!cap)
2795 		goto out;
2796 
2797 	err = pci_read_config_word(dev, cap + PCI_EXP_DEVCTL, &ctl);
2798 	if (err)
2799 		goto out;
2800 
2801 	if ((ctl & PCI_EXP_DEVCTL_READRQ) != v) {
2802 		ctl &= ~PCI_EXP_DEVCTL_READRQ;
2803 		ctl |= v;
2804 		err = pci_write_config_dword(dev, cap + PCI_EXP_DEVCTL, ctl);
2805 	}
2806 
2807 out:
2808 	return err;
2809 }
2810 EXPORT_SYMBOL(pcie_set_readrq);
2811 
2812 /**
2813  * pci_select_bars - Make BAR mask from the type of resource
2814  * @dev: the PCI device for which BAR mask is made
2815  * @flags: resource type mask to be selected
2816  *
2817  * This helper routine makes bar mask from the type of resource.
2818  */
2819 int pci_select_bars(struct pci_dev *dev, unsigned long flags)
2820 {
2821 	int i, bars = 0;
2822 	for (i = 0; i < PCI_NUM_RESOURCES; i++)
2823 		if (pci_resource_flags(dev, i) & flags)
2824 			bars |= (1 << i);
2825 	return bars;
2826 }
2827 
2828 /**
2829  * pci_resource_bar - get position of the BAR associated with a resource
2830  * @dev: the PCI device
2831  * @resno: the resource number
2832  * @type: the BAR type to be filled in
2833  *
2834  * Returns BAR position in config space, or 0 if the BAR is invalid.
2835  */
2836 int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type)
2837 {
2838 	int reg;
2839 
2840 	if (resno < PCI_ROM_RESOURCE) {
2841 		*type = pci_bar_unknown;
2842 		return PCI_BASE_ADDRESS_0 + 4 * resno;
2843 	} else if (resno == PCI_ROM_RESOURCE) {
2844 		*type = pci_bar_mem32;
2845 		return dev->rom_base_reg;
2846 	} else if (resno < PCI_BRIDGE_RESOURCES) {
2847 		/* device specific resource */
2848 		reg = pci_iov_resource_bar(dev, resno, type);
2849 		if (reg)
2850 			return reg;
2851 	}
2852 
2853 	dev_err(&dev->dev, "BAR %d: invalid resource\n", resno);
2854 	return 0;
2855 }
2856 
2857 /* Some architectures require additional programming to enable VGA */
2858 static arch_set_vga_state_t arch_set_vga_state;
2859 
2860 void __init pci_register_set_vga_state(arch_set_vga_state_t func)
2861 {
2862 	arch_set_vga_state = func;	/* NULL disables */
2863 }
2864 
2865 static int pci_set_vga_state_arch(struct pci_dev *dev, bool decode,
2866 		      unsigned int command_bits, bool change_bridge)
2867 {
2868 	if (arch_set_vga_state)
2869 		return arch_set_vga_state(dev, decode, command_bits,
2870 						change_bridge);
2871 	return 0;
2872 }
2873 
2874 /**
2875  * pci_set_vga_state - set VGA decode state on device and parents if requested
2876  * @dev: the PCI device
2877  * @decode: true = enable decoding, false = disable decoding
2878  * @command_bits: PCI_COMMAND_IO and/or PCI_COMMAND_MEMORY
2879  * @change_bridge: traverse ancestors and change bridges
2880  */
2881 int pci_set_vga_state(struct pci_dev *dev, bool decode,
2882 		      unsigned int command_bits, bool change_bridge)
2883 {
2884 	struct pci_bus *bus;
2885 	struct pci_dev *bridge;
2886 	u16 cmd;
2887 	int rc;
2888 
2889 	WARN_ON(command_bits & ~(PCI_COMMAND_IO|PCI_COMMAND_MEMORY));
2890 
2891 	/* ARCH specific VGA enables */
2892 	rc = pci_set_vga_state_arch(dev, decode, command_bits, change_bridge);
2893 	if (rc)
2894 		return rc;
2895 
2896 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
2897 	if (decode == true)
2898 		cmd |= command_bits;
2899 	else
2900 		cmd &= ~command_bits;
2901 	pci_write_config_word(dev, PCI_COMMAND, cmd);
2902 
2903 	if (change_bridge == false)
2904 		return 0;
2905 
2906 	bus = dev->bus;
2907 	while (bus) {
2908 		bridge = bus->self;
2909 		if (bridge) {
2910 			pci_read_config_word(bridge, PCI_BRIDGE_CONTROL,
2911 					     &cmd);
2912 			if (decode == true)
2913 				cmd |= PCI_BRIDGE_CTL_VGA;
2914 			else
2915 				cmd &= ~PCI_BRIDGE_CTL_VGA;
2916 			pci_write_config_word(bridge, PCI_BRIDGE_CONTROL,
2917 					      cmd);
2918 		}
2919 		bus = bus->parent;
2920 	}
2921 	return 0;
2922 }
2923 
2924 #define RESOURCE_ALIGNMENT_PARAM_SIZE COMMAND_LINE_SIZE
2925 static char resource_alignment_param[RESOURCE_ALIGNMENT_PARAM_SIZE] = {0};
2926 static DEFINE_SPINLOCK(resource_alignment_lock);
2927 
2928 /**
2929  * pci_specified_resource_alignment - get resource alignment specified by user.
2930  * @dev: the PCI device to get
2931  *
2932  * RETURNS: Resource alignment if it is specified.
2933  *          Zero if it is not specified.
2934  */
2935 resource_size_t pci_specified_resource_alignment(struct pci_dev *dev)
2936 {
2937 	int seg, bus, slot, func, align_order, count;
2938 	resource_size_t align = 0;
2939 	char *p;
2940 
2941 	spin_lock(&resource_alignment_lock);
2942 	p = resource_alignment_param;
2943 	while (*p) {
2944 		count = 0;
2945 		if (sscanf(p, "%d%n", &align_order, &count) == 1 &&
2946 							p[count] == '@') {
2947 			p += count + 1;
2948 		} else {
2949 			align_order = -1;
2950 		}
2951 		if (sscanf(p, "%x:%x:%x.%x%n",
2952 			&seg, &bus, &slot, &func, &count) != 4) {
2953 			seg = 0;
2954 			if (sscanf(p, "%x:%x.%x%n",
2955 					&bus, &slot, &func, &count) != 3) {
2956 				/* Invalid format */
2957 				printk(KERN_ERR "PCI: Can't parse resource_alignment parameter: %s\n",
2958 					p);
2959 				break;
2960 			}
2961 		}
2962 		p += count;
2963 		if (seg == pci_domain_nr(dev->bus) &&
2964 			bus == dev->bus->number &&
2965 			slot == PCI_SLOT(dev->devfn) &&
2966 			func == PCI_FUNC(dev->devfn)) {
2967 			if (align_order == -1) {
2968 				align = PAGE_SIZE;
2969 			} else {
2970 				align = 1 << align_order;
2971 			}
2972 			/* Found */
2973 			break;
2974 		}
2975 		if (*p != ';' && *p != ',') {
2976 			/* End of param or invalid format */
2977 			break;
2978 		}
2979 		p++;
2980 	}
2981 	spin_unlock(&resource_alignment_lock);
2982 	return align;
2983 }
2984 
2985 /**
2986  * pci_is_reassigndev - check if specified PCI is target device to reassign
2987  * @dev: the PCI device to check
2988  *
2989  * RETURNS: non-zero for PCI device is a target device to reassign,
2990  *          or zero is not.
2991  */
2992 int pci_is_reassigndev(struct pci_dev *dev)
2993 {
2994 	return (pci_specified_resource_alignment(dev) != 0);
2995 }
2996 
2997 ssize_t pci_set_resource_alignment_param(const char *buf, size_t count)
2998 {
2999 	if (count > RESOURCE_ALIGNMENT_PARAM_SIZE - 1)
3000 		count = RESOURCE_ALIGNMENT_PARAM_SIZE - 1;
3001 	spin_lock(&resource_alignment_lock);
3002 	strncpy(resource_alignment_param, buf, count);
3003 	resource_alignment_param[count] = '\0';
3004 	spin_unlock(&resource_alignment_lock);
3005 	return count;
3006 }
3007 
3008 ssize_t pci_get_resource_alignment_param(char *buf, size_t size)
3009 {
3010 	size_t count;
3011 	spin_lock(&resource_alignment_lock);
3012 	count = snprintf(buf, size, "%s", resource_alignment_param);
3013 	spin_unlock(&resource_alignment_lock);
3014 	return count;
3015 }
3016 
3017 static ssize_t pci_resource_alignment_show(struct bus_type *bus, char *buf)
3018 {
3019 	return pci_get_resource_alignment_param(buf, PAGE_SIZE);
3020 }
3021 
3022 static ssize_t pci_resource_alignment_store(struct bus_type *bus,
3023 					const char *buf, size_t count)
3024 {
3025 	return pci_set_resource_alignment_param(buf, count);
3026 }
3027 
3028 BUS_ATTR(resource_alignment, 0644, pci_resource_alignment_show,
3029 					pci_resource_alignment_store);
3030 
3031 static int __init pci_resource_alignment_sysfs_init(void)
3032 {
3033 	return bus_create_file(&pci_bus_type,
3034 					&bus_attr_resource_alignment);
3035 }
3036 
3037 late_initcall(pci_resource_alignment_sysfs_init);
3038 
3039 static void __devinit pci_no_domains(void)
3040 {
3041 #ifdef CONFIG_PCI_DOMAINS
3042 	pci_domains_supported = 0;
3043 #endif
3044 }
3045 
3046 /**
3047  * pci_ext_cfg_enabled - can we access extended PCI config space?
3048  * @dev: The PCI device of the root bridge.
3049  *
3050  * Returns 1 if we can access PCI extended config space (offsets
3051  * greater than 0xff). This is the default implementation. Architecture
3052  * implementations can override this.
3053  */
3054 int __attribute__ ((weak)) pci_ext_cfg_avail(struct pci_dev *dev)
3055 {
3056 	return 1;
3057 }
3058 
3059 void __weak pci_fixup_cardbus(struct pci_bus *bus)
3060 {
3061 }
3062 EXPORT_SYMBOL(pci_fixup_cardbus);
3063 
3064 static int __init pci_setup(char *str)
3065 {
3066 	while (str) {
3067 		char *k = strchr(str, ',');
3068 		if (k)
3069 			*k++ = 0;
3070 		if (*str && (str = pcibios_setup(str)) && *str) {
3071 			if (!strcmp(str, "nomsi")) {
3072 				pci_no_msi();
3073 			} else if (!strcmp(str, "noaer")) {
3074 				pci_no_aer();
3075 			} else if (!strcmp(str, "nodomains")) {
3076 				pci_no_domains();
3077 			} else if (!strncmp(str, "cbiosize=", 9)) {
3078 				pci_cardbus_io_size = memparse(str + 9, &str);
3079 			} else if (!strncmp(str, "cbmemsize=", 10)) {
3080 				pci_cardbus_mem_size = memparse(str + 10, &str);
3081 			} else if (!strncmp(str, "resource_alignment=", 19)) {
3082 				pci_set_resource_alignment_param(str + 19,
3083 							strlen(str + 19));
3084 			} else if (!strncmp(str, "ecrc=", 5)) {
3085 				pcie_ecrc_get_policy(str + 5);
3086 			} else if (!strncmp(str, "hpiosize=", 9)) {
3087 				pci_hotplug_io_size = memparse(str + 9, &str);
3088 			} else if (!strncmp(str, "hpmemsize=", 10)) {
3089 				pci_hotplug_mem_size = memparse(str + 10, &str);
3090 			} else {
3091 				printk(KERN_ERR "PCI: Unknown option `%s'\n",
3092 						str);
3093 			}
3094 		}
3095 		str = k;
3096 	}
3097 	return 0;
3098 }
3099 early_param("pci", pci_setup);
3100 
3101 EXPORT_SYMBOL(pci_reenable_device);
3102 EXPORT_SYMBOL(pci_enable_device_io);
3103 EXPORT_SYMBOL(pci_enable_device_mem);
3104 EXPORT_SYMBOL(pci_enable_device);
3105 EXPORT_SYMBOL(pcim_enable_device);
3106 EXPORT_SYMBOL(pcim_pin_device);
3107 EXPORT_SYMBOL(pci_disable_device);
3108 EXPORT_SYMBOL(pci_find_capability);
3109 EXPORT_SYMBOL(pci_bus_find_capability);
3110 EXPORT_SYMBOL(pci_release_regions);
3111 EXPORT_SYMBOL(pci_request_regions);
3112 EXPORT_SYMBOL(pci_request_regions_exclusive);
3113 EXPORT_SYMBOL(pci_release_region);
3114 EXPORT_SYMBOL(pci_request_region);
3115 EXPORT_SYMBOL(pci_request_region_exclusive);
3116 EXPORT_SYMBOL(pci_release_selected_regions);
3117 EXPORT_SYMBOL(pci_request_selected_regions);
3118 EXPORT_SYMBOL(pci_request_selected_regions_exclusive);
3119 EXPORT_SYMBOL(pci_set_master);
3120 EXPORT_SYMBOL(pci_clear_master);
3121 EXPORT_SYMBOL(pci_set_mwi);
3122 EXPORT_SYMBOL(pci_try_set_mwi);
3123 EXPORT_SYMBOL(pci_clear_mwi);
3124 EXPORT_SYMBOL_GPL(pci_intx);
3125 EXPORT_SYMBOL(pci_assign_resource);
3126 EXPORT_SYMBOL(pci_find_parent_resource);
3127 EXPORT_SYMBOL(pci_select_bars);
3128 
3129 EXPORT_SYMBOL(pci_set_power_state);
3130 EXPORT_SYMBOL(pci_save_state);
3131 EXPORT_SYMBOL(pci_restore_state);
3132 EXPORT_SYMBOL(pci_pme_capable);
3133 EXPORT_SYMBOL(pci_pme_active);
3134 EXPORT_SYMBOL(pci_wake_from_d3);
3135 EXPORT_SYMBOL(pci_target_state);
3136 EXPORT_SYMBOL(pci_prepare_to_sleep);
3137 EXPORT_SYMBOL(pci_back_from_sleep);
3138 EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state);
3139