xref: /openbmc/linux/drivers/pci/pci.c (revision 81d67439)
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 	 * When aspm_policy is "powersave" this call ensures
745 	 * that ASPM is configured.
746 	 */
747 	if (!error && dev->bus->self)
748 		pcie_aspm_powersave_config_link(dev->bus->self);
749 
750 	return error;
751 }
752 
753 /**
754  * pci_choose_state - Choose the power state of a PCI device
755  * @dev: PCI device to be suspended
756  * @state: target sleep state for the whole system. This is the value
757  *	that is passed to suspend() function.
758  *
759  * Returns PCI power state suitable for given device and given system
760  * message.
761  */
762 
763 pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state)
764 {
765 	pci_power_t ret;
766 
767 	if (!pci_find_capability(dev, PCI_CAP_ID_PM))
768 		return PCI_D0;
769 
770 	ret = platform_pci_choose_state(dev);
771 	if (ret != PCI_POWER_ERROR)
772 		return ret;
773 
774 	switch (state.event) {
775 	case PM_EVENT_ON:
776 		return PCI_D0;
777 	case PM_EVENT_FREEZE:
778 	case PM_EVENT_PRETHAW:
779 		/* REVISIT both freeze and pre-thaw "should" use D0 */
780 	case PM_EVENT_SUSPEND:
781 	case PM_EVENT_HIBERNATE:
782 		return PCI_D3hot;
783 	default:
784 		dev_info(&dev->dev, "unrecognized suspend event %d\n",
785 			 state.event);
786 		BUG();
787 	}
788 	return PCI_D0;
789 }
790 
791 EXPORT_SYMBOL(pci_choose_state);
792 
793 #define PCI_EXP_SAVE_REGS	7
794 
795 #define pcie_cap_has_devctl(type, flags)	1
796 #define pcie_cap_has_lnkctl(type, flags)		\
797 		((flags & PCI_EXP_FLAGS_VERS) > 1 ||	\
798 		 (type == PCI_EXP_TYPE_ROOT_PORT ||	\
799 		  type == PCI_EXP_TYPE_ENDPOINT ||	\
800 		  type == PCI_EXP_TYPE_LEG_END))
801 #define pcie_cap_has_sltctl(type, flags)		\
802 		((flags & PCI_EXP_FLAGS_VERS) > 1 ||	\
803 		 ((type == PCI_EXP_TYPE_ROOT_PORT) ||	\
804 		  (type == PCI_EXP_TYPE_DOWNSTREAM &&	\
805 		   (flags & PCI_EXP_FLAGS_SLOT))))
806 #define pcie_cap_has_rtctl(type, flags)			\
807 		((flags & PCI_EXP_FLAGS_VERS) > 1 ||	\
808 		 (type == PCI_EXP_TYPE_ROOT_PORT ||	\
809 		  type == PCI_EXP_TYPE_RC_EC))
810 #define pcie_cap_has_devctl2(type, flags)		\
811 		((flags & PCI_EXP_FLAGS_VERS) > 1)
812 #define pcie_cap_has_lnkctl2(type, flags)		\
813 		((flags & PCI_EXP_FLAGS_VERS) > 1)
814 #define pcie_cap_has_sltctl2(type, flags)		\
815 		((flags & PCI_EXP_FLAGS_VERS) > 1)
816 
817 static int pci_save_pcie_state(struct pci_dev *dev)
818 {
819 	int pos, i = 0;
820 	struct pci_cap_saved_state *save_state;
821 	u16 *cap;
822 	u16 flags;
823 
824 	pos = pci_pcie_cap(dev);
825 	if (!pos)
826 		return 0;
827 
828 	save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
829 	if (!save_state) {
830 		dev_err(&dev->dev, "buffer not found in %s\n", __func__);
831 		return -ENOMEM;
832 	}
833 	cap = (u16 *)&save_state->cap.data[0];
834 
835 	pci_read_config_word(dev, pos + PCI_EXP_FLAGS, &flags);
836 
837 	if (pcie_cap_has_devctl(dev->pcie_type, flags))
838 		pci_read_config_word(dev, pos + PCI_EXP_DEVCTL, &cap[i++]);
839 	if (pcie_cap_has_lnkctl(dev->pcie_type, flags))
840 		pci_read_config_word(dev, pos + PCI_EXP_LNKCTL, &cap[i++]);
841 	if (pcie_cap_has_sltctl(dev->pcie_type, flags))
842 		pci_read_config_word(dev, pos + PCI_EXP_SLTCTL, &cap[i++]);
843 	if (pcie_cap_has_rtctl(dev->pcie_type, flags))
844 		pci_read_config_word(dev, pos + PCI_EXP_RTCTL, &cap[i++]);
845 	if (pcie_cap_has_devctl2(dev->pcie_type, flags))
846 		pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &cap[i++]);
847 	if (pcie_cap_has_lnkctl2(dev->pcie_type, flags))
848 		pci_read_config_word(dev, pos + PCI_EXP_LNKCTL2, &cap[i++]);
849 	if (pcie_cap_has_sltctl2(dev->pcie_type, flags))
850 		pci_read_config_word(dev, pos + PCI_EXP_SLTCTL2, &cap[i++]);
851 
852 	return 0;
853 }
854 
855 static void pci_restore_pcie_state(struct pci_dev *dev)
856 {
857 	int i = 0, pos;
858 	struct pci_cap_saved_state *save_state;
859 	u16 *cap;
860 	u16 flags;
861 
862 	save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
863 	pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
864 	if (!save_state || pos <= 0)
865 		return;
866 	cap = (u16 *)&save_state->cap.data[0];
867 
868 	pci_read_config_word(dev, pos + PCI_EXP_FLAGS, &flags);
869 
870 	if (pcie_cap_has_devctl(dev->pcie_type, flags))
871 		pci_write_config_word(dev, pos + PCI_EXP_DEVCTL, cap[i++]);
872 	if (pcie_cap_has_lnkctl(dev->pcie_type, flags))
873 		pci_write_config_word(dev, pos + PCI_EXP_LNKCTL, cap[i++]);
874 	if (pcie_cap_has_sltctl(dev->pcie_type, flags))
875 		pci_write_config_word(dev, pos + PCI_EXP_SLTCTL, cap[i++]);
876 	if (pcie_cap_has_rtctl(dev->pcie_type, flags))
877 		pci_write_config_word(dev, pos + PCI_EXP_RTCTL, cap[i++]);
878 	if (pcie_cap_has_devctl2(dev->pcie_type, flags))
879 		pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, cap[i++]);
880 	if (pcie_cap_has_lnkctl2(dev->pcie_type, flags))
881 		pci_write_config_word(dev, pos + PCI_EXP_LNKCTL2, cap[i++]);
882 	if (pcie_cap_has_sltctl2(dev->pcie_type, flags))
883 		pci_write_config_word(dev, pos + PCI_EXP_SLTCTL2, cap[i++]);
884 }
885 
886 
887 static int pci_save_pcix_state(struct pci_dev *dev)
888 {
889 	int pos;
890 	struct pci_cap_saved_state *save_state;
891 
892 	pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
893 	if (pos <= 0)
894 		return 0;
895 
896 	save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX);
897 	if (!save_state) {
898 		dev_err(&dev->dev, "buffer not found in %s\n", __func__);
899 		return -ENOMEM;
900 	}
901 
902 	pci_read_config_word(dev, pos + PCI_X_CMD,
903 			     (u16 *)save_state->cap.data);
904 
905 	return 0;
906 }
907 
908 static void pci_restore_pcix_state(struct pci_dev *dev)
909 {
910 	int i = 0, pos;
911 	struct pci_cap_saved_state *save_state;
912 	u16 *cap;
913 
914 	save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX);
915 	pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
916 	if (!save_state || pos <= 0)
917 		return;
918 	cap = (u16 *)&save_state->cap.data[0];
919 
920 	pci_write_config_word(dev, pos + PCI_X_CMD, cap[i++]);
921 }
922 
923 
924 /**
925  * pci_save_state - save the PCI configuration space of a device before suspending
926  * @dev: - PCI device that we're dealing with
927  */
928 int
929 pci_save_state(struct pci_dev *dev)
930 {
931 	int i;
932 	/* XXX: 100% dword access ok here? */
933 	for (i = 0; i < 16; i++)
934 		pci_read_config_dword(dev, i * 4, &dev->saved_config_space[i]);
935 	dev->state_saved = true;
936 	if ((i = pci_save_pcie_state(dev)) != 0)
937 		return i;
938 	if ((i = pci_save_pcix_state(dev)) != 0)
939 		return i;
940 	return 0;
941 }
942 
943 /**
944  * pci_restore_state - Restore the saved state of a PCI device
945  * @dev: - PCI device that we're dealing with
946  */
947 void pci_restore_state(struct pci_dev *dev)
948 {
949 	int i;
950 	u32 val;
951 
952 	if (!dev->state_saved)
953 		return;
954 
955 	/* PCI Express register must be restored first */
956 	pci_restore_pcie_state(dev);
957 
958 	/*
959 	 * The Base Address register should be programmed before the command
960 	 * register(s)
961 	 */
962 	for (i = 15; i >= 0; i--) {
963 		pci_read_config_dword(dev, i * 4, &val);
964 		if (val != dev->saved_config_space[i]) {
965 			dev_printk(KERN_DEBUG, &dev->dev, "restoring config "
966 				"space at offset %#x (was %#x, writing %#x)\n",
967 				i, val, (int)dev->saved_config_space[i]);
968 			pci_write_config_dword(dev,i * 4,
969 				dev->saved_config_space[i]);
970 		}
971 	}
972 	pci_restore_pcix_state(dev);
973 	pci_restore_msi_state(dev);
974 	pci_restore_iov_state(dev);
975 
976 	dev->state_saved = false;
977 }
978 
979 struct pci_saved_state {
980 	u32 config_space[16];
981 	struct pci_cap_saved_data cap[0];
982 };
983 
984 /**
985  * pci_store_saved_state - Allocate and return an opaque struct containing
986  *			   the device saved state.
987  * @dev: PCI device that we're dealing with
988  *
989  * Rerturn NULL if no state or error.
990  */
991 struct pci_saved_state *pci_store_saved_state(struct pci_dev *dev)
992 {
993 	struct pci_saved_state *state;
994 	struct pci_cap_saved_state *tmp;
995 	struct pci_cap_saved_data *cap;
996 	struct hlist_node *pos;
997 	size_t size;
998 
999 	if (!dev->state_saved)
1000 		return NULL;
1001 
1002 	size = sizeof(*state) + sizeof(struct pci_cap_saved_data);
1003 
1004 	hlist_for_each_entry(tmp, pos, &dev->saved_cap_space, next)
1005 		size += sizeof(struct pci_cap_saved_data) + tmp->cap.size;
1006 
1007 	state = kzalloc(size, GFP_KERNEL);
1008 	if (!state)
1009 		return NULL;
1010 
1011 	memcpy(state->config_space, dev->saved_config_space,
1012 	       sizeof(state->config_space));
1013 
1014 	cap = state->cap;
1015 	hlist_for_each_entry(tmp, pos, &dev->saved_cap_space, next) {
1016 		size_t len = sizeof(struct pci_cap_saved_data) + tmp->cap.size;
1017 		memcpy(cap, &tmp->cap, len);
1018 		cap = (struct pci_cap_saved_data *)((u8 *)cap + len);
1019 	}
1020 	/* Empty cap_save terminates list */
1021 
1022 	return state;
1023 }
1024 EXPORT_SYMBOL_GPL(pci_store_saved_state);
1025 
1026 /**
1027  * pci_load_saved_state - Reload the provided save state into struct pci_dev.
1028  * @dev: PCI device that we're dealing with
1029  * @state: Saved state returned from pci_store_saved_state()
1030  */
1031 int pci_load_saved_state(struct pci_dev *dev, struct pci_saved_state *state)
1032 {
1033 	struct pci_cap_saved_data *cap;
1034 
1035 	dev->state_saved = false;
1036 
1037 	if (!state)
1038 		return 0;
1039 
1040 	memcpy(dev->saved_config_space, state->config_space,
1041 	       sizeof(state->config_space));
1042 
1043 	cap = state->cap;
1044 	while (cap->size) {
1045 		struct pci_cap_saved_state *tmp;
1046 
1047 		tmp = pci_find_saved_cap(dev, cap->cap_nr);
1048 		if (!tmp || tmp->cap.size != cap->size)
1049 			return -EINVAL;
1050 
1051 		memcpy(tmp->cap.data, cap->data, tmp->cap.size);
1052 		cap = (struct pci_cap_saved_data *)((u8 *)cap +
1053 		       sizeof(struct pci_cap_saved_data) + cap->size);
1054 	}
1055 
1056 	dev->state_saved = true;
1057 	return 0;
1058 }
1059 EXPORT_SYMBOL_GPL(pci_load_saved_state);
1060 
1061 /**
1062  * pci_load_and_free_saved_state - Reload the save state pointed to by state,
1063  *				   and free the memory allocated for it.
1064  * @dev: PCI device that we're dealing with
1065  * @state: Pointer to saved state returned from pci_store_saved_state()
1066  */
1067 int pci_load_and_free_saved_state(struct pci_dev *dev,
1068 				  struct pci_saved_state **state)
1069 {
1070 	int ret = pci_load_saved_state(dev, *state);
1071 	kfree(*state);
1072 	*state = NULL;
1073 	return ret;
1074 }
1075 EXPORT_SYMBOL_GPL(pci_load_and_free_saved_state);
1076 
1077 static int do_pci_enable_device(struct pci_dev *dev, int bars)
1078 {
1079 	int err;
1080 
1081 	err = pci_set_power_state(dev, PCI_D0);
1082 	if (err < 0 && err != -EIO)
1083 		return err;
1084 	err = pcibios_enable_device(dev, bars);
1085 	if (err < 0)
1086 		return err;
1087 	pci_fixup_device(pci_fixup_enable, dev);
1088 
1089 	return 0;
1090 }
1091 
1092 /**
1093  * pci_reenable_device - Resume abandoned device
1094  * @dev: PCI device to be resumed
1095  *
1096  *  Note this function is a backend of pci_default_resume and is not supposed
1097  *  to be called by normal code, write proper resume handler and use it instead.
1098  */
1099 int pci_reenable_device(struct pci_dev *dev)
1100 {
1101 	if (pci_is_enabled(dev))
1102 		return do_pci_enable_device(dev, (1 << PCI_NUM_RESOURCES) - 1);
1103 	return 0;
1104 }
1105 
1106 static int __pci_enable_device_flags(struct pci_dev *dev,
1107 				     resource_size_t flags)
1108 {
1109 	int err;
1110 	int i, bars = 0;
1111 
1112 	/*
1113 	 * Power state could be unknown at this point, either due to a fresh
1114 	 * boot or a device removal call.  So get the current power state
1115 	 * so that things like MSI message writing will behave as expected
1116 	 * (e.g. if the device really is in D0 at enable time).
1117 	 */
1118 	if (dev->pm_cap) {
1119 		u16 pmcsr;
1120 		pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
1121 		dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
1122 	}
1123 
1124 	if (atomic_add_return(1, &dev->enable_cnt) > 1)
1125 		return 0;		/* already enabled */
1126 
1127 	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++)
1128 		if (dev->resource[i].flags & flags)
1129 			bars |= (1 << i);
1130 
1131 	err = do_pci_enable_device(dev, bars);
1132 	if (err < 0)
1133 		atomic_dec(&dev->enable_cnt);
1134 	return err;
1135 }
1136 
1137 /**
1138  * pci_enable_device_io - Initialize a device for use with IO space
1139  * @dev: PCI device to be initialized
1140  *
1141  *  Initialize device before it's used by a driver. Ask low-level code
1142  *  to enable I/O resources. Wake up the device if it was suspended.
1143  *  Beware, this function can fail.
1144  */
1145 int pci_enable_device_io(struct pci_dev *dev)
1146 {
1147 	return __pci_enable_device_flags(dev, IORESOURCE_IO);
1148 }
1149 
1150 /**
1151  * pci_enable_device_mem - Initialize a device for use with Memory space
1152  * @dev: PCI device to be initialized
1153  *
1154  *  Initialize device before it's used by a driver. Ask low-level code
1155  *  to enable Memory resources. Wake up the device if it was suspended.
1156  *  Beware, this function can fail.
1157  */
1158 int pci_enable_device_mem(struct pci_dev *dev)
1159 {
1160 	return __pci_enable_device_flags(dev, IORESOURCE_MEM);
1161 }
1162 
1163 /**
1164  * pci_enable_device - Initialize device before it's used by a driver.
1165  * @dev: PCI device to be initialized
1166  *
1167  *  Initialize device before it's used by a driver. Ask low-level code
1168  *  to enable I/O and memory. Wake up the device if it was suspended.
1169  *  Beware, this function can fail.
1170  *
1171  *  Note we don't actually enable the device many times if we call
1172  *  this function repeatedly (we just increment the count).
1173  */
1174 int pci_enable_device(struct pci_dev *dev)
1175 {
1176 	return __pci_enable_device_flags(dev, IORESOURCE_MEM | IORESOURCE_IO);
1177 }
1178 
1179 /*
1180  * Managed PCI resources.  This manages device on/off, intx/msi/msix
1181  * on/off and BAR regions.  pci_dev itself records msi/msix status, so
1182  * there's no need to track it separately.  pci_devres is initialized
1183  * when a device is enabled using managed PCI device enable interface.
1184  */
1185 struct pci_devres {
1186 	unsigned int enabled:1;
1187 	unsigned int pinned:1;
1188 	unsigned int orig_intx:1;
1189 	unsigned int restore_intx:1;
1190 	u32 region_mask;
1191 };
1192 
1193 static void pcim_release(struct device *gendev, void *res)
1194 {
1195 	struct pci_dev *dev = container_of(gendev, struct pci_dev, dev);
1196 	struct pci_devres *this = res;
1197 	int i;
1198 
1199 	if (dev->msi_enabled)
1200 		pci_disable_msi(dev);
1201 	if (dev->msix_enabled)
1202 		pci_disable_msix(dev);
1203 
1204 	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++)
1205 		if (this->region_mask & (1 << i))
1206 			pci_release_region(dev, i);
1207 
1208 	if (this->restore_intx)
1209 		pci_intx(dev, this->orig_intx);
1210 
1211 	if (this->enabled && !this->pinned)
1212 		pci_disable_device(dev);
1213 }
1214 
1215 static struct pci_devres * get_pci_dr(struct pci_dev *pdev)
1216 {
1217 	struct pci_devres *dr, *new_dr;
1218 
1219 	dr = devres_find(&pdev->dev, pcim_release, NULL, NULL);
1220 	if (dr)
1221 		return dr;
1222 
1223 	new_dr = devres_alloc(pcim_release, sizeof(*new_dr), GFP_KERNEL);
1224 	if (!new_dr)
1225 		return NULL;
1226 	return devres_get(&pdev->dev, new_dr, NULL, NULL);
1227 }
1228 
1229 static struct pci_devres * find_pci_dr(struct pci_dev *pdev)
1230 {
1231 	if (pci_is_managed(pdev))
1232 		return devres_find(&pdev->dev, pcim_release, NULL, NULL);
1233 	return NULL;
1234 }
1235 
1236 /**
1237  * pcim_enable_device - Managed pci_enable_device()
1238  * @pdev: PCI device to be initialized
1239  *
1240  * Managed pci_enable_device().
1241  */
1242 int pcim_enable_device(struct pci_dev *pdev)
1243 {
1244 	struct pci_devres *dr;
1245 	int rc;
1246 
1247 	dr = get_pci_dr(pdev);
1248 	if (unlikely(!dr))
1249 		return -ENOMEM;
1250 	if (dr->enabled)
1251 		return 0;
1252 
1253 	rc = pci_enable_device(pdev);
1254 	if (!rc) {
1255 		pdev->is_managed = 1;
1256 		dr->enabled = 1;
1257 	}
1258 	return rc;
1259 }
1260 
1261 /**
1262  * pcim_pin_device - Pin managed PCI device
1263  * @pdev: PCI device to pin
1264  *
1265  * Pin managed PCI device @pdev.  Pinned device won't be disabled on
1266  * driver detach.  @pdev must have been enabled with
1267  * pcim_enable_device().
1268  */
1269 void pcim_pin_device(struct pci_dev *pdev)
1270 {
1271 	struct pci_devres *dr;
1272 
1273 	dr = find_pci_dr(pdev);
1274 	WARN_ON(!dr || !dr->enabled);
1275 	if (dr)
1276 		dr->pinned = 1;
1277 }
1278 
1279 /**
1280  * pcibios_disable_device - disable arch specific PCI resources for device dev
1281  * @dev: the PCI device to disable
1282  *
1283  * Disables architecture specific PCI resources for the device. This
1284  * is the default implementation. Architecture implementations can
1285  * override this.
1286  */
1287 void __attribute__ ((weak)) pcibios_disable_device (struct pci_dev *dev) {}
1288 
1289 static void do_pci_disable_device(struct pci_dev *dev)
1290 {
1291 	u16 pci_command;
1292 
1293 	pci_read_config_word(dev, PCI_COMMAND, &pci_command);
1294 	if (pci_command & PCI_COMMAND_MASTER) {
1295 		pci_command &= ~PCI_COMMAND_MASTER;
1296 		pci_write_config_word(dev, PCI_COMMAND, pci_command);
1297 	}
1298 
1299 	pcibios_disable_device(dev);
1300 }
1301 
1302 /**
1303  * pci_disable_enabled_device - Disable device without updating enable_cnt
1304  * @dev: PCI device to disable
1305  *
1306  * NOTE: This function is a backend of PCI power management routines and is
1307  * not supposed to be called drivers.
1308  */
1309 void pci_disable_enabled_device(struct pci_dev *dev)
1310 {
1311 	if (pci_is_enabled(dev))
1312 		do_pci_disable_device(dev);
1313 }
1314 
1315 /**
1316  * pci_disable_device - Disable PCI device after use
1317  * @dev: PCI device to be disabled
1318  *
1319  * Signal to the system that the PCI device is not in use by the system
1320  * anymore.  This only involves disabling PCI bus-mastering, if active.
1321  *
1322  * Note we don't actually disable the device until all callers of
1323  * pci_enable_device() have called pci_disable_device().
1324  */
1325 void
1326 pci_disable_device(struct pci_dev *dev)
1327 {
1328 	struct pci_devres *dr;
1329 
1330 	dr = find_pci_dr(dev);
1331 	if (dr)
1332 		dr->enabled = 0;
1333 
1334 	if (atomic_sub_return(1, &dev->enable_cnt) != 0)
1335 		return;
1336 
1337 	do_pci_disable_device(dev);
1338 
1339 	dev->is_busmaster = 0;
1340 }
1341 
1342 /**
1343  * pcibios_set_pcie_reset_state - set reset state for device dev
1344  * @dev: the PCIe device reset
1345  * @state: Reset state to enter into
1346  *
1347  *
1348  * Sets the PCIe reset state for the device. This is the default
1349  * implementation. Architecture implementations can override this.
1350  */
1351 int __attribute__ ((weak)) pcibios_set_pcie_reset_state(struct pci_dev *dev,
1352 							enum pcie_reset_state state)
1353 {
1354 	return -EINVAL;
1355 }
1356 
1357 /**
1358  * pci_set_pcie_reset_state - set reset state for device dev
1359  * @dev: the PCIe device reset
1360  * @state: Reset state to enter into
1361  *
1362  *
1363  * Sets the PCI reset state for the device.
1364  */
1365 int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state)
1366 {
1367 	return pcibios_set_pcie_reset_state(dev, state);
1368 }
1369 
1370 /**
1371  * pci_check_pme_status - Check if given device has generated PME.
1372  * @dev: Device to check.
1373  *
1374  * Check the PME status of the device and if set, clear it and clear PME enable
1375  * (if set).  Return 'true' if PME status and PME enable were both set or
1376  * 'false' otherwise.
1377  */
1378 bool pci_check_pme_status(struct pci_dev *dev)
1379 {
1380 	int pmcsr_pos;
1381 	u16 pmcsr;
1382 	bool ret = false;
1383 
1384 	if (!dev->pm_cap)
1385 		return false;
1386 
1387 	pmcsr_pos = dev->pm_cap + PCI_PM_CTRL;
1388 	pci_read_config_word(dev, pmcsr_pos, &pmcsr);
1389 	if (!(pmcsr & PCI_PM_CTRL_PME_STATUS))
1390 		return false;
1391 
1392 	/* Clear PME status. */
1393 	pmcsr |= PCI_PM_CTRL_PME_STATUS;
1394 	if (pmcsr & PCI_PM_CTRL_PME_ENABLE) {
1395 		/* Disable PME to avoid interrupt flood. */
1396 		pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
1397 		ret = true;
1398 	}
1399 
1400 	pci_write_config_word(dev, pmcsr_pos, pmcsr);
1401 
1402 	return ret;
1403 }
1404 
1405 /**
1406  * pci_pme_wakeup - Wake up a PCI device if its PME Status bit is set.
1407  * @dev: Device to handle.
1408  * @ign: Ignored.
1409  *
1410  * Check if @dev has generated PME and queue a resume request for it in that
1411  * case.
1412  */
1413 static int pci_pme_wakeup(struct pci_dev *dev, void *ign)
1414 {
1415 	if (pci_check_pme_status(dev)) {
1416 		pci_wakeup_event(dev);
1417 		pm_request_resume(&dev->dev);
1418 	}
1419 	return 0;
1420 }
1421 
1422 /**
1423  * pci_pme_wakeup_bus - Walk given bus and wake up devices on it, if necessary.
1424  * @bus: Top bus of the subtree to walk.
1425  */
1426 void pci_pme_wakeup_bus(struct pci_bus *bus)
1427 {
1428 	if (bus)
1429 		pci_walk_bus(bus, pci_pme_wakeup, NULL);
1430 }
1431 
1432 /**
1433  * pci_pme_capable - check the capability of PCI device to generate PME#
1434  * @dev: PCI device to handle.
1435  * @state: PCI state from which device will issue PME#.
1436  */
1437 bool pci_pme_capable(struct pci_dev *dev, pci_power_t state)
1438 {
1439 	if (!dev->pm_cap)
1440 		return false;
1441 
1442 	return !!(dev->pme_support & (1 << state));
1443 }
1444 
1445 static void pci_pme_list_scan(struct work_struct *work)
1446 {
1447 	struct pci_pme_device *pme_dev;
1448 
1449 	mutex_lock(&pci_pme_list_mutex);
1450 	if (!list_empty(&pci_pme_list)) {
1451 		list_for_each_entry(pme_dev, &pci_pme_list, list)
1452 			pci_pme_wakeup(pme_dev->dev, NULL);
1453 		schedule_delayed_work(&pci_pme_work, msecs_to_jiffies(PME_TIMEOUT));
1454 	}
1455 	mutex_unlock(&pci_pme_list_mutex);
1456 }
1457 
1458 /**
1459  * pci_external_pme - is a device an external PCI PME source?
1460  * @dev: PCI device to check
1461  *
1462  */
1463 
1464 static bool pci_external_pme(struct pci_dev *dev)
1465 {
1466 	if (pci_is_pcie(dev) || dev->bus->number == 0)
1467 		return false;
1468 	return true;
1469 }
1470 
1471 /**
1472  * pci_pme_active - enable or disable PCI device's PME# function
1473  * @dev: PCI device to handle.
1474  * @enable: 'true' to enable PME# generation; 'false' to disable it.
1475  *
1476  * The caller must verify that the device is capable of generating PME# before
1477  * calling this function with @enable equal to 'true'.
1478  */
1479 void pci_pme_active(struct pci_dev *dev, bool enable)
1480 {
1481 	u16 pmcsr;
1482 
1483 	if (!dev->pm_cap)
1484 		return;
1485 
1486 	pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
1487 	/* Clear PME_Status by writing 1 to it and enable PME# */
1488 	pmcsr |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE;
1489 	if (!enable)
1490 		pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
1491 
1492 	pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
1493 
1494 	/* PCI (as opposed to PCIe) PME requires that the device have
1495 	   its PME# line hooked up correctly. Not all hardware vendors
1496 	   do this, so the PME never gets delivered and the device
1497 	   remains asleep. The easiest way around this is to
1498 	   periodically walk the list of suspended devices and check
1499 	   whether any have their PME flag set. The assumption is that
1500 	   we'll wake up often enough anyway that this won't be a huge
1501 	   hit, and the power savings from the devices will still be a
1502 	   win. */
1503 
1504 	if (pci_external_pme(dev)) {
1505 		struct pci_pme_device *pme_dev;
1506 		if (enable) {
1507 			pme_dev = kmalloc(sizeof(struct pci_pme_device),
1508 					  GFP_KERNEL);
1509 			if (!pme_dev)
1510 				goto out;
1511 			pme_dev->dev = dev;
1512 			mutex_lock(&pci_pme_list_mutex);
1513 			list_add(&pme_dev->list, &pci_pme_list);
1514 			if (list_is_singular(&pci_pme_list))
1515 				schedule_delayed_work(&pci_pme_work,
1516 						      msecs_to_jiffies(PME_TIMEOUT));
1517 			mutex_unlock(&pci_pme_list_mutex);
1518 		} else {
1519 			mutex_lock(&pci_pme_list_mutex);
1520 			list_for_each_entry(pme_dev, &pci_pme_list, list) {
1521 				if (pme_dev->dev == dev) {
1522 					list_del(&pme_dev->list);
1523 					kfree(pme_dev);
1524 					break;
1525 				}
1526 			}
1527 			mutex_unlock(&pci_pme_list_mutex);
1528 		}
1529 	}
1530 
1531 out:
1532 	dev_printk(KERN_DEBUG, &dev->dev, "PME# %s\n",
1533 			enable ? "enabled" : "disabled");
1534 }
1535 
1536 /**
1537  * __pci_enable_wake - enable PCI device as wakeup event source
1538  * @dev: PCI device affected
1539  * @state: PCI state from which device will issue wakeup events
1540  * @runtime: True if the events are to be generated at run time
1541  * @enable: True to enable event generation; false to disable
1542  *
1543  * This enables the device as a wakeup event source, or disables it.
1544  * When such events involves platform-specific hooks, those hooks are
1545  * called automatically by this routine.
1546  *
1547  * Devices with legacy power management (no standard PCI PM capabilities)
1548  * always require such platform hooks.
1549  *
1550  * RETURN VALUE:
1551  * 0 is returned on success
1552  * -EINVAL is returned if device is not supposed to wake up the system
1553  * Error code depending on the platform is returned if both the platform and
1554  * the native mechanism fail to enable the generation of wake-up events
1555  */
1556 int __pci_enable_wake(struct pci_dev *dev, pci_power_t state,
1557 		      bool runtime, bool enable)
1558 {
1559 	int ret = 0;
1560 
1561 	if (enable && !runtime && !device_may_wakeup(&dev->dev))
1562 		return -EINVAL;
1563 
1564 	/* Don't do the same thing twice in a row for one device. */
1565 	if (!!enable == !!dev->wakeup_prepared)
1566 		return 0;
1567 
1568 	/*
1569 	 * According to "PCI System Architecture" 4th ed. by Tom Shanley & Don
1570 	 * Anderson we should be doing PME# wake enable followed by ACPI wake
1571 	 * enable.  To disable wake-up we call the platform first, for symmetry.
1572 	 */
1573 
1574 	if (enable) {
1575 		int error;
1576 
1577 		if (pci_pme_capable(dev, state))
1578 			pci_pme_active(dev, true);
1579 		else
1580 			ret = 1;
1581 		error = runtime ? platform_pci_run_wake(dev, true) :
1582 					platform_pci_sleep_wake(dev, true);
1583 		if (ret)
1584 			ret = error;
1585 		if (!ret)
1586 			dev->wakeup_prepared = true;
1587 	} else {
1588 		if (runtime)
1589 			platform_pci_run_wake(dev, false);
1590 		else
1591 			platform_pci_sleep_wake(dev, false);
1592 		pci_pme_active(dev, false);
1593 		dev->wakeup_prepared = false;
1594 	}
1595 
1596 	return ret;
1597 }
1598 EXPORT_SYMBOL(__pci_enable_wake);
1599 
1600 /**
1601  * pci_wake_from_d3 - enable/disable device to wake up from D3_hot or D3_cold
1602  * @dev: PCI device to prepare
1603  * @enable: True to enable wake-up event generation; false to disable
1604  *
1605  * Many drivers want the device to wake up the system from D3_hot or D3_cold
1606  * and this function allows them to set that up cleanly - pci_enable_wake()
1607  * should not be called twice in a row to enable wake-up due to PCI PM vs ACPI
1608  * ordering constraints.
1609  *
1610  * This function only returns error code if the device is not capable of
1611  * generating PME# from both D3_hot and D3_cold, and the platform is unable to
1612  * enable wake-up power for it.
1613  */
1614 int pci_wake_from_d3(struct pci_dev *dev, bool enable)
1615 {
1616 	return pci_pme_capable(dev, PCI_D3cold) ?
1617 			pci_enable_wake(dev, PCI_D3cold, enable) :
1618 			pci_enable_wake(dev, PCI_D3hot, enable);
1619 }
1620 
1621 /**
1622  * pci_target_state - find an appropriate low power state for a given PCI dev
1623  * @dev: PCI device
1624  *
1625  * Use underlying platform code to find a supported low power state for @dev.
1626  * If the platform can't manage @dev, return the deepest state from which it
1627  * can generate wake events, based on any available PME info.
1628  */
1629 pci_power_t pci_target_state(struct pci_dev *dev)
1630 {
1631 	pci_power_t target_state = PCI_D3hot;
1632 
1633 	if (platform_pci_power_manageable(dev)) {
1634 		/*
1635 		 * Call the platform to choose the target state of the device
1636 		 * and enable wake-up from this state if supported.
1637 		 */
1638 		pci_power_t state = platform_pci_choose_state(dev);
1639 
1640 		switch (state) {
1641 		case PCI_POWER_ERROR:
1642 		case PCI_UNKNOWN:
1643 			break;
1644 		case PCI_D1:
1645 		case PCI_D2:
1646 			if (pci_no_d1d2(dev))
1647 				break;
1648 		default:
1649 			target_state = state;
1650 		}
1651 	} else if (!dev->pm_cap) {
1652 		target_state = PCI_D0;
1653 	} else if (device_may_wakeup(&dev->dev)) {
1654 		/*
1655 		 * Find the deepest state from which the device can generate
1656 		 * wake-up events, make it the target state and enable device
1657 		 * to generate PME#.
1658 		 */
1659 		if (dev->pme_support) {
1660 			while (target_state
1661 			      && !(dev->pme_support & (1 << target_state)))
1662 				target_state--;
1663 		}
1664 	}
1665 
1666 	return target_state;
1667 }
1668 
1669 /**
1670  * pci_prepare_to_sleep - prepare PCI device for system-wide transition into a sleep state
1671  * @dev: Device to handle.
1672  *
1673  * Choose the power state appropriate for the device depending on whether
1674  * it can wake up the system and/or is power manageable by the platform
1675  * (PCI_D3hot is the default) and put the device into that state.
1676  */
1677 int pci_prepare_to_sleep(struct pci_dev *dev)
1678 {
1679 	pci_power_t target_state = pci_target_state(dev);
1680 	int error;
1681 
1682 	if (target_state == PCI_POWER_ERROR)
1683 		return -EIO;
1684 
1685 	pci_enable_wake(dev, target_state, device_may_wakeup(&dev->dev));
1686 
1687 	error = pci_set_power_state(dev, target_state);
1688 
1689 	if (error)
1690 		pci_enable_wake(dev, target_state, false);
1691 
1692 	return error;
1693 }
1694 
1695 /**
1696  * pci_back_from_sleep - turn PCI device on during system-wide transition into working state
1697  * @dev: Device to handle.
1698  *
1699  * Disable device's system wake-up capability and put it into D0.
1700  */
1701 int pci_back_from_sleep(struct pci_dev *dev)
1702 {
1703 	pci_enable_wake(dev, PCI_D0, false);
1704 	return pci_set_power_state(dev, PCI_D0);
1705 }
1706 
1707 /**
1708  * pci_finish_runtime_suspend - Carry out PCI-specific part of runtime suspend.
1709  * @dev: PCI device being suspended.
1710  *
1711  * Prepare @dev to generate wake-up events at run time and put it into a low
1712  * power state.
1713  */
1714 int pci_finish_runtime_suspend(struct pci_dev *dev)
1715 {
1716 	pci_power_t target_state = pci_target_state(dev);
1717 	int error;
1718 
1719 	if (target_state == PCI_POWER_ERROR)
1720 		return -EIO;
1721 
1722 	__pci_enable_wake(dev, target_state, true, pci_dev_run_wake(dev));
1723 
1724 	error = pci_set_power_state(dev, target_state);
1725 
1726 	if (error)
1727 		__pci_enable_wake(dev, target_state, true, false);
1728 
1729 	return error;
1730 }
1731 
1732 /**
1733  * pci_dev_run_wake - Check if device can generate run-time wake-up events.
1734  * @dev: Device to check.
1735  *
1736  * Return true if the device itself is cabable of generating wake-up events
1737  * (through the platform or using the native PCIe PME) or if the device supports
1738  * PME and one of its upstream bridges can generate wake-up events.
1739  */
1740 bool pci_dev_run_wake(struct pci_dev *dev)
1741 {
1742 	struct pci_bus *bus = dev->bus;
1743 
1744 	if (device_run_wake(&dev->dev))
1745 		return true;
1746 
1747 	if (!dev->pme_support)
1748 		return false;
1749 
1750 	while (bus->parent) {
1751 		struct pci_dev *bridge = bus->self;
1752 
1753 		if (device_run_wake(&bridge->dev))
1754 			return true;
1755 
1756 		bus = bus->parent;
1757 	}
1758 
1759 	/* We have reached the root bus. */
1760 	if (bus->bridge)
1761 		return device_run_wake(bus->bridge);
1762 
1763 	return false;
1764 }
1765 EXPORT_SYMBOL_GPL(pci_dev_run_wake);
1766 
1767 /**
1768  * pci_pm_init - Initialize PM functions of given PCI device
1769  * @dev: PCI device to handle.
1770  */
1771 void pci_pm_init(struct pci_dev *dev)
1772 {
1773 	int pm;
1774 	u16 pmc;
1775 
1776 	pm_runtime_forbid(&dev->dev);
1777 	device_enable_async_suspend(&dev->dev);
1778 	dev->wakeup_prepared = false;
1779 
1780 	dev->pm_cap = 0;
1781 
1782 	/* find PCI PM capability in list */
1783 	pm = pci_find_capability(dev, PCI_CAP_ID_PM);
1784 	if (!pm)
1785 		return;
1786 	/* Check device's ability to generate PME# */
1787 	pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
1788 
1789 	if ((pmc & PCI_PM_CAP_VER_MASK) > 3) {
1790 		dev_err(&dev->dev, "unsupported PM cap regs version (%u)\n",
1791 			pmc & PCI_PM_CAP_VER_MASK);
1792 		return;
1793 	}
1794 
1795 	dev->pm_cap = pm;
1796 	dev->d3_delay = PCI_PM_D3_WAIT;
1797 
1798 	dev->d1_support = false;
1799 	dev->d2_support = false;
1800 	if (!pci_no_d1d2(dev)) {
1801 		if (pmc & PCI_PM_CAP_D1)
1802 			dev->d1_support = true;
1803 		if (pmc & PCI_PM_CAP_D2)
1804 			dev->d2_support = true;
1805 
1806 		if (dev->d1_support || dev->d2_support)
1807 			dev_printk(KERN_DEBUG, &dev->dev, "supports%s%s\n",
1808 				   dev->d1_support ? " D1" : "",
1809 				   dev->d2_support ? " D2" : "");
1810 	}
1811 
1812 	pmc &= PCI_PM_CAP_PME_MASK;
1813 	if (pmc) {
1814 		dev_printk(KERN_DEBUG, &dev->dev,
1815 			 "PME# supported from%s%s%s%s%s\n",
1816 			 (pmc & PCI_PM_CAP_PME_D0) ? " D0" : "",
1817 			 (pmc & PCI_PM_CAP_PME_D1) ? " D1" : "",
1818 			 (pmc & PCI_PM_CAP_PME_D2) ? " D2" : "",
1819 			 (pmc & PCI_PM_CAP_PME_D3) ? " D3hot" : "",
1820 			 (pmc & PCI_PM_CAP_PME_D3cold) ? " D3cold" : "");
1821 		dev->pme_support = pmc >> PCI_PM_CAP_PME_SHIFT;
1822 		/*
1823 		 * Make device's PM flags reflect the wake-up capability, but
1824 		 * let the user space enable it to wake up the system as needed.
1825 		 */
1826 		device_set_wakeup_capable(&dev->dev, true);
1827 		/* Disable the PME# generation functionality */
1828 		pci_pme_active(dev, false);
1829 	} else {
1830 		dev->pme_support = 0;
1831 	}
1832 }
1833 
1834 /**
1835  * platform_pci_wakeup_init - init platform wakeup if present
1836  * @dev: PCI device
1837  *
1838  * Some devices don't have PCI PM caps but can still generate wakeup
1839  * events through platform methods (like ACPI events).  If @dev supports
1840  * platform wakeup events, set the device flag to indicate as much.  This
1841  * may be redundant if the device also supports PCI PM caps, but double
1842  * initialization should be safe in that case.
1843  */
1844 void platform_pci_wakeup_init(struct pci_dev *dev)
1845 {
1846 	if (!platform_pci_can_wakeup(dev))
1847 		return;
1848 
1849 	device_set_wakeup_capable(&dev->dev, true);
1850 	platform_pci_sleep_wake(dev, false);
1851 }
1852 
1853 /**
1854  * pci_add_save_buffer - allocate buffer for saving given capability registers
1855  * @dev: the PCI device
1856  * @cap: the capability to allocate the buffer for
1857  * @size: requested size of the buffer
1858  */
1859 static int pci_add_cap_save_buffer(
1860 	struct pci_dev *dev, char cap, unsigned int size)
1861 {
1862 	int pos;
1863 	struct pci_cap_saved_state *save_state;
1864 
1865 	pos = pci_find_capability(dev, cap);
1866 	if (pos <= 0)
1867 		return 0;
1868 
1869 	save_state = kzalloc(sizeof(*save_state) + size, GFP_KERNEL);
1870 	if (!save_state)
1871 		return -ENOMEM;
1872 
1873 	save_state->cap.cap_nr = cap;
1874 	save_state->cap.size = size;
1875 	pci_add_saved_cap(dev, save_state);
1876 
1877 	return 0;
1878 }
1879 
1880 /**
1881  * pci_allocate_cap_save_buffers - allocate buffers for saving capabilities
1882  * @dev: the PCI device
1883  */
1884 void pci_allocate_cap_save_buffers(struct pci_dev *dev)
1885 {
1886 	int error;
1887 
1888 	error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_EXP,
1889 					PCI_EXP_SAVE_REGS * sizeof(u16));
1890 	if (error)
1891 		dev_err(&dev->dev,
1892 			"unable to preallocate PCI Express save buffer\n");
1893 
1894 	error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_PCIX, sizeof(u16));
1895 	if (error)
1896 		dev_err(&dev->dev,
1897 			"unable to preallocate PCI-X save buffer\n");
1898 }
1899 
1900 /**
1901  * pci_enable_ari - enable ARI forwarding if hardware support it
1902  * @dev: the PCI device
1903  */
1904 void pci_enable_ari(struct pci_dev *dev)
1905 {
1906 	int pos;
1907 	u32 cap;
1908 	u16 ctrl;
1909 	struct pci_dev *bridge;
1910 
1911 	if (!pci_is_pcie(dev) || dev->devfn)
1912 		return;
1913 
1914 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI);
1915 	if (!pos)
1916 		return;
1917 
1918 	bridge = dev->bus->self;
1919 	if (!bridge || !pci_is_pcie(bridge))
1920 		return;
1921 
1922 	pos = pci_pcie_cap(bridge);
1923 	if (!pos)
1924 		return;
1925 
1926 	pci_read_config_dword(bridge, pos + PCI_EXP_DEVCAP2, &cap);
1927 	if (!(cap & PCI_EXP_DEVCAP2_ARI))
1928 		return;
1929 
1930 	pci_read_config_word(bridge, pos + PCI_EXP_DEVCTL2, &ctrl);
1931 	ctrl |= PCI_EXP_DEVCTL2_ARI;
1932 	pci_write_config_word(bridge, pos + PCI_EXP_DEVCTL2, ctrl);
1933 
1934 	bridge->ari_enabled = 1;
1935 }
1936 
1937 /**
1938  * pci_enable_ido - enable ID-based ordering on a device
1939  * @dev: the PCI device
1940  * @type: which types of IDO to enable
1941  *
1942  * Enable ID-based ordering on @dev.  @type can contain the bits
1943  * %PCI_EXP_IDO_REQUEST and/or %PCI_EXP_IDO_COMPLETION to indicate
1944  * which types of transactions are allowed to be re-ordered.
1945  */
1946 void pci_enable_ido(struct pci_dev *dev, unsigned long type)
1947 {
1948 	int pos;
1949 	u16 ctrl;
1950 
1951 	pos = pci_pcie_cap(dev);
1952 	if (!pos)
1953 		return;
1954 
1955 	pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &ctrl);
1956 	if (type & PCI_EXP_IDO_REQUEST)
1957 		ctrl |= PCI_EXP_IDO_REQ_EN;
1958 	if (type & PCI_EXP_IDO_COMPLETION)
1959 		ctrl |= PCI_EXP_IDO_CMP_EN;
1960 	pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, ctrl);
1961 }
1962 EXPORT_SYMBOL(pci_enable_ido);
1963 
1964 /**
1965  * pci_disable_ido - disable ID-based ordering on a device
1966  * @dev: the PCI device
1967  * @type: which types of IDO to disable
1968  */
1969 void pci_disable_ido(struct pci_dev *dev, unsigned long type)
1970 {
1971 	int pos;
1972 	u16 ctrl;
1973 
1974 	if (!pci_is_pcie(dev))
1975 		return;
1976 
1977 	pos = pci_pcie_cap(dev);
1978 	if (!pos)
1979 		return;
1980 
1981 	pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &ctrl);
1982 	if (type & PCI_EXP_IDO_REQUEST)
1983 		ctrl &= ~PCI_EXP_IDO_REQ_EN;
1984 	if (type & PCI_EXP_IDO_COMPLETION)
1985 		ctrl &= ~PCI_EXP_IDO_CMP_EN;
1986 	pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, ctrl);
1987 }
1988 EXPORT_SYMBOL(pci_disable_ido);
1989 
1990 /**
1991  * pci_enable_obff - enable optimized buffer flush/fill
1992  * @dev: PCI device
1993  * @type: type of signaling to use
1994  *
1995  * Try to enable @type OBFF signaling on @dev.  It will try using WAKE#
1996  * signaling if possible, falling back to message signaling only if
1997  * WAKE# isn't supported.  @type should indicate whether the PCIe link
1998  * be brought out of L0s or L1 to send the message.  It should be either
1999  * %PCI_EXP_OBFF_SIGNAL_ALWAYS or %PCI_OBFF_SIGNAL_L0.
2000  *
2001  * If your device can benefit from receiving all messages, even at the
2002  * power cost of bringing the link back up from a low power state, use
2003  * %PCI_EXP_OBFF_SIGNAL_ALWAYS.  Otherwise, use %PCI_OBFF_SIGNAL_L0 (the
2004  * preferred type).
2005  *
2006  * RETURNS:
2007  * Zero on success, appropriate error number on failure.
2008  */
2009 int pci_enable_obff(struct pci_dev *dev, enum pci_obff_signal_type type)
2010 {
2011 	int pos;
2012 	u32 cap;
2013 	u16 ctrl;
2014 	int ret;
2015 
2016 	if (!pci_is_pcie(dev))
2017 		return -ENOTSUPP;
2018 
2019 	pos = pci_pcie_cap(dev);
2020 	if (!pos)
2021 		return -ENOTSUPP;
2022 
2023 	pci_read_config_dword(dev, pos + PCI_EXP_DEVCAP2, &cap);
2024 	if (!(cap & PCI_EXP_OBFF_MASK))
2025 		return -ENOTSUPP; /* no OBFF support at all */
2026 
2027 	/* Make sure the topology supports OBFF as well */
2028 	if (dev->bus) {
2029 		ret = pci_enable_obff(dev->bus->self, type);
2030 		if (ret)
2031 			return ret;
2032 	}
2033 
2034 	pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &ctrl);
2035 	if (cap & PCI_EXP_OBFF_WAKE)
2036 		ctrl |= PCI_EXP_OBFF_WAKE_EN;
2037 	else {
2038 		switch (type) {
2039 		case PCI_EXP_OBFF_SIGNAL_L0:
2040 			if (!(ctrl & PCI_EXP_OBFF_WAKE_EN))
2041 				ctrl |= PCI_EXP_OBFF_MSGA_EN;
2042 			break;
2043 		case PCI_EXP_OBFF_SIGNAL_ALWAYS:
2044 			ctrl &= ~PCI_EXP_OBFF_WAKE_EN;
2045 			ctrl |= PCI_EXP_OBFF_MSGB_EN;
2046 			break;
2047 		default:
2048 			WARN(1, "bad OBFF signal type\n");
2049 			return -ENOTSUPP;
2050 		}
2051 	}
2052 	pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, ctrl);
2053 
2054 	return 0;
2055 }
2056 EXPORT_SYMBOL(pci_enable_obff);
2057 
2058 /**
2059  * pci_disable_obff - disable optimized buffer flush/fill
2060  * @dev: PCI device
2061  *
2062  * Disable OBFF on @dev.
2063  */
2064 void pci_disable_obff(struct pci_dev *dev)
2065 {
2066 	int pos;
2067 	u16 ctrl;
2068 
2069 	if (!pci_is_pcie(dev))
2070 		return;
2071 
2072 	pos = pci_pcie_cap(dev);
2073 	if (!pos)
2074 		return;
2075 
2076 	pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &ctrl);
2077 	ctrl &= ~PCI_EXP_OBFF_WAKE_EN;
2078 	pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, ctrl);
2079 }
2080 EXPORT_SYMBOL(pci_disable_obff);
2081 
2082 /**
2083  * pci_ltr_supported - check whether a device supports LTR
2084  * @dev: PCI device
2085  *
2086  * RETURNS:
2087  * True if @dev supports latency tolerance reporting, false otherwise.
2088  */
2089 bool pci_ltr_supported(struct pci_dev *dev)
2090 {
2091 	int pos;
2092 	u32 cap;
2093 
2094 	if (!pci_is_pcie(dev))
2095 		return false;
2096 
2097 	pos = pci_pcie_cap(dev);
2098 	if (!pos)
2099 		return false;
2100 
2101 	pci_read_config_dword(dev, pos + PCI_EXP_DEVCAP2, &cap);
2102 
2103 	return cap & PCI_EXP_DEVCAP2_LTR;
2104 }
2105 EXPORT_SYMBOL(pci_ltr_supported);
2106 
2107 /**
2108  * pci_enable_ltr - enable latency tolerance reporting
2109  * @dev: PCI device
2110  *
2111  * Enable LTR on @dev if possible, which means enabling it first on
2112  * upstream ports.
2113  *
2114  * RETURNS:
2115  * Zero on success, errno on failure.
2116  */
2117 int pci_enable_ltr(struct pci_dev *dev)
2118 {
2119 	int pos;
2120 	u16 ctrl;
2121 	int ret;
2122 
2123 	if (!pci_ltr_supported(dev))
2124 		return -ENOTSUPP;
2125 
2126 	pos = pci_pcie_cap(dev);
2127 	if (!pos)
2128 		return -ENOTSUPP;
2129 
2130 	/* Only primary function can enable/disable LTR */
2131 	if (PCI_FUNC(dev->devfn) != 0)
2132 		return -EINVAL;
2133 
2134 	/* Enable upstream ports first */
2135 	if (dev->bus) {
2136 		ret = pci_enable_ltr(dev->bus->self);
2137 		if (ret)
2138 			return ret;
2139 	}
2140 
2141 	pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &ctrl);
2142 	ctrl |= PCI_EXP_LTR_EN;
2143 	pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, ctrl);
2144 
2145 	return 0;
2146 }
2147 EXPORT_SYMBOL(pci_enable_ltr);
2148 
2149 /**
2150  * pci_disable_ltr - disable latency tolerance reporting
2151  * @dev: PCI device
2152  */
2153 void pci_disable_ltr(struct pci_dev *dev)
2154 {
2155 	int pos;
2156 	u16 ctrl;
2157 
2158 	if (!pci_ltr_supported(dev))
2159 		return;
2160 
2161 	pos = pci_pcie_cap(dev);
2162 	if (!pos)
2163 		return;
2164 
2165 	/* Only primary function can enable/disable LTR */
2166 	if (PCI_FUNC(dev->devfn) != 0)
2167 		return;
2168 
2169 	pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &ctrl);
2170 	ctrl &= ~PCI_EXP_LTR_EN;
2171 	pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, ctrl);
2172 }
2173 EXPORT_SYMBOL(pci_disable_ltr);
2174 
2175 static int __pci_ltr_scale(int *val)
2176 {
2177 	int scale = 0;
2178 
2179 	while (*val > 1023) {
2180 		*val = (*val + 31) / 32;
2181 		scale++;
2182 	}
2183 	return scale;
2184 }
2185 
2186 /**
2187  * pci_set_ltr - set LTR latency values
2188  * @dev: PCI device
2189  * @snoop_lat_ns: snoop latency in nanoseconds
2190  * @nosnoop_lat_ns: nosnoop latency in nanoseconds
2191  *
2192  * Figure out the scale and set the LTR values accordingly.
2193  */
2194 int pci_set_ltr(struct pci_dev *dev, int snoop_lat_ns, int nosnoop_lat_ns)
2195 {
2196 	int pos, ret, snoop_scale, nosnoop_scale;
2197 	u16 val;
2198 
2199 	if (!pci_ltr_supported(dev))
2200 		return -ENOTSUPP;
2201 
2202 	snoop_scale = __pci_ltr_scale(&snoop_lat_ns);
2203 	nosnoop_scale = __pci_ltr_scale(&nosnoop_lat_ns);
2204 
2205 	if (snoop_lat_ns > PCI_LTR_VALUE_MASK ||
2206 	    nosnoop_lat_ns > PCI_LTR_VALUE_MASK)
2207 		return -EINVAL;
2208 
2209 	if ((snoop_scale > (PCI_LTR_SCALE_MASK >> PCI_LTR_SCALE_SHIFT)) ||
2210 	    (nosnoop_scale > (PCI_LTR_SCALE_MASK >> PCI_LTR_SCALE_SHIFT)))
2211 		return -EINVAL;
2212 
2213 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR);
2214 	if (!pos)
2215 		return -ENOTSUPP;
2216 
2217 	val = (snoop_scale << PCI_LTR_SCALE_SHIFT) | snoop_lat_ns;
2218 	ret = pci_write_config_word(dev, pos + PCI_LTR_MAX_SNOOP_LAT, val);
2219 	if (ret != 4)
2220 		return -EIO;
2221 
2222 	val = (nosnoop_scale << PCI_LTR_SCALE_SHIFT) | nosnoop_lat_ns;
2223 	ret = pci_write_config_word(dev, pos + PCI_LTR_MAX_NOSNOOP_LAT, val);
2224 	if (ret != 4)
2225 		return -EIO;
2226 
2227 	return 0;
2228 }
2229 EXPORT_SYMBOL(pci_set_ltr);
2230 
2231 static int pci_acs_enable;
2232 
2233 /**
2234  * pci_request_acs - ask for ACS to be enabled if supported
2235  */
2236 void pci_request_acs(void)
2237 {
2238 	pci_acs_enable = 1;
2239 }
2240 
2241 /**
2242  * pci_enable_acs - enable ACS if hardware support it
2243  * @dev: the PCI device
2244  */
2245 void pci_enable_acs(struct pci_dev *dev)
2246 {
2247 	int pos;
2248 	u16 cap;
2249 	u16 ctrl;
2250 
2251 	if (!pci_acs_enable)
2252 		return;
2253 
2254 	if (!pci_is_pcie(dev))
2255 		return;
2256 
2257 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS);
2258 	if (!pos)
2259 		return;
2260 
2261 	pci_read_config_word(dev, pos + PCI_ACS_CAP, &cap);
2262 	pci_read_config_word(dev, pos + PCI_ACS_CTRL, &ctrl);
2263 
2264 	/* Source Validation */
2265 	ctrl |= (cap & PCI_ACS_SV);
2266 
2267 	/* P2P Request Redirect */
2268 	ctrl |= (cap & PCI_ACS_RR);
2269 
2270 	/* P2P Completion Redirect */
2271 	ctrl |= (cap & PCI_ACS_CR);
2272 
2273 	/* Upstream Forwarding */
2274 	ctrl |= (cap & PCI_ACS_UF);
2275 
2276 	pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl);
2277 }
2278 
2279 /**
2280  * pci_swizzle_interrupt_pin - swizzle INTx for device behind bridge
2281  * @dev: the PCI device
2282  * @pin: the INTx pin (1=INTA, 2=INTB, 3=INTD, 4=INTD)
2283  *
2284  * Perform INTx swizzling for a device behind one level of bridge.  This is
2285  * required by section 9.1 of the PCI-to-PCI bridge specification for devices
2286  * behind bridges on add-in cards.  For devices with ARI enabled, the slot
2287  * number is always 0 (see the Implementation Note in section 2.2.8.1 of
2288  * the PCI Express Base Specification, Revision 2.1)
2289  */
2290 u8 pci_swizzle_interrupt_pin(struct pci_dev *dev, u8 pin)
2291 {
2292 	int slot;
2293 
2294 	if (pci_ari_enabled(dev->bus))
2295 		slot = 0;
2296 	else
2297 		slot = PCI_SLOT(dev->devfn);
2298 
2299 	return (((pin - 1) + slot) % 4) + 1;
2300 }
2301 
2302 int
2303 pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge)
2304 {
2305 	u8 pin;
2306 
2307 	pin = dev->pin;
2308 	if (!pin)
2309 		return -1;
2310 
2311 	while (!pci_is_root_bus(dev->bus)) {
2312 		pin = pci_swizzle_interrupt_pin(dev, pin);
2313 		dev = dev->bus->self;
2314 	}
2315 	*bridge = dev;
2316 	return pin;
2317 }
2318 
2319 /**
2320  * pci_common_swizzle - swizzle INTx all the way to root bridge
2321  * @dev: the PCI device
2322  * @pinp: pointer to the INTx pin value (1=INTA, 2=INTB, 3=INTD, 4=INTD)
2323  *
2324  * Perform INTx swizzling for a device.  This traverses through all PCI-to-PCI
2325  * bridges all the way up to a PCI root bus.
2326  */
2327 u8 pci_common_swizzle(struct pci_dev *dev, u8 *pinp)
2328 {
2329 	u8 pin = *pinp;
2330 
2331 	while (!pci_is_root_bus(dev->bus)) {
2332 		pin = pci_swizzle_interrupt_pin(dev, pin);
2333 		dev = dev->bus->self;
2334 	}
2335 	*pinp = pin;
2336 	return PCI_SLOT(dev->devfn);
2337 }
2338 
2339 /**
2340  *	pci_release_region - Release a PCI bar
2341  *	@pdev: PCI device whose resources were previously reserved by pci_request_region
2342  *	@bar: BAR to release
2343  *
2344  *	Releases the PCI I/O and memory resources previously reserved by a
2345  *	successful call to pci_request_region.  Call this function only
2346  *	after all use of the PCI regions has ceased.
2347  */
2348 void pci_release_region(struct pci_dev *pdev, int bar)
2349 {
2350 	struct pci_devres *dr;
2351 
2352 	if (pci_resource_len(pdev, bar) == 0)
2353 		return;
2354 	if (pci_resource_flags(pdev, bar) & IORESOURCE_IO)
2355 		release_region(pci_resource_start(pdev, bar),
2356 				pci_resource_len(pdev, bar));
2357 	else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM)
2358 		release_mem_region(pci_resource_start(pdev, bar),
2359 				pci_resource_len(pdev, bar));
2360 
2361 	dr = find_pci_dr(pdev);
2362 	if (dr)
2363 		dr->region_mask &= ~(1 << bar);
2364 }
2365 
2366 /**
2367  *	__pci_request_region - Reserved PCI I/O and memory resource
2368  *	@pdev: PCI device whose resources are to be reserved
2369  *	@bar: BAR to be reserved
2370  *	@res_name: Name to be associated with resource.
2371  *	@exclusive: whether the region access is exclusive or not
2372  *
2373  *	Mark the PCI region associated with PCI device @pdev BR @bar as
2374  *	being reserved by owner @res_name.  Do not access any
2375  *	address inside the PCI regions unless this call returns
2376  *	successfully.
2377  *
2378  *	If @exclusive is set, then the region is marked so that userspace
2379  *	is explicitly not allowed to map the resource via /dev/mem or
2380  * 	sysfs MMIO access.
2381  *
2382  *	Returns 0 on success, or %EBUSY on error.  A warning
2383  *	message is also printed on failure.
2384  */
2385 static int __pci_request_region(struct pci_dev *pdev, int bar, const char *res_name,
2386 									int exclusive)
2387 {
2388 	struct pci_devres *dr;
2389 
2390 	if (pci_resource_len(pdev, bar) == 0)
2391 		return 0;
2392 
2393 	if (pci_resource_flags(pdev, bar) & IORESOURCE_IO) {
2394 		if (!request_region(pci_resource_start(pdev, bar),
2395 			    pci_resource_len(pdev, bar), res_name))
2396 			goto err_out;
2397 	}
2398 	else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM) {
2399 		if (!__request_mem_region(pci_resource_start(pdev, bar),
2400 					pci_resource_len(pdev, bar), res_name,
2401 					exclusive))
2402 			goto err_out;
2403 	}
2404 
2405 	dr = find_pci_dr(pdev);
2406 	if (dr)
2407 		dr->region_mask |= 1 << bar;
2408 
2409 	return 0;
2410 
2411 err_out:
2412 	dev_warn(&pdev->dev, "BAR %d: can't reserve %pR\n", bar,
2413 		 &pdev->resource[bar]);
2414 	return -EBUSY;
2415 }
2416 
2417 /**
2418  *	pci_request_region - Reserve PCI I/O and memory resource
2419  *	@pdev: PCI device whose resources are to be reserved
2420  *	@bar: BAR to be reserved
2421  *	@res_name: Name to be associated with resource
2422  *
2423  *	Mark the PCI region associated with PCI device @pdev BAR @bar as
2424  *	being reserved by owner @res_name.  Do not access any
2425  *	address inside the PCI regions unless this call returns
2426  *	successfully.
2427  *
2428  *	Returns 0 on success, or %EBUSY on error.  A warning
2429  *	message is also printed on failure.
2430  */
2431 int pci_request_region(struct pci_dev *pdev, int bar, const char *res_name)
2432 {
2433 	return __pci_request_region(pdev, bar, res_name, 0);
2434 }
2435 
2436 /**
2437  *	pci_request_region_exclusive - Reserved PCI I/O and memory resource
2438  *	@pdev: PCI device whose resources are to be reserved
2439  *	@bar: BAR to be reserved
2440  *	@res_name: Name to be associated with resource.
2441  *
2442  *	Mark the PCI region associated with PCI device @pdev BR @bar as
2443  *	being reserved by owner @res_name.  Do not access any
2444  *	address inside the PCI regions unless this call returns
2445  *	successfully.
2446  *
2447  *	Returns 0 on success, or %EBUSY on error.  A warning
2448  *	message is also printed on failure.
2449  *
2450  *	The key difference that _exclusive makes it that userspace is
2451  *	explicitly not allowed to map the resource via /dev/mem or
2452  * 	sysfs.
2453  */
2454 int pci_request_region_exclusive(struct pci_dev *pdev, int bar, const char *res_name)
2455 {
2456 	return __pci_request_region(pdev, bar, res_name, IORESOURCE_EXCLUSIVE);
2457 }
2458 /**
2459  * pci_release_selected_regions - Release selected PCI I/O and memory resources
2460  * @pdev: PCI device whose resources were previously reserved
2461  * @bars: Bitmask of BARs to be released
2462  *
2463  * Release selected PCI I/O and memory resources previously reserved.
2464  * Call this function only after all use of the PCI regions has ceased.
2465  */
2466 void pci_release_selected_regions(struct pci_dev *pdev, int bars)
2467 {
2468 	int i;
2469 
2470 	for (i = 0; i < 6; i++)
2471 		if (bars & (1 << i))
2472 			pci_release_region(pdev, i);
2473 }
2474 
2475 int __pci_request_selected_regions(struct pci_dev *pdev, int bars,
2476 				 const char *res_name, int excl)
2477 {
2478 	int i;
2479 
2480 	for (i = 0; i < 6; i++)
2481 		if (bars & (1 << i))
2482 			if (__pci_request_region(pdev, i, res_name, excl))
2483 				goto err_out;
2484 	return 0;
2485 
2486 err_out:
2487 	while(--i >= 0)
2488 		if (bars & (1 << i))
2489 			pci_release_region(pdev, i);
2490 
2491 	return -EBUSY;
2492 }
2493 
2494 
2495 /**
2496  * pci_request_selected_regions - Reserve selected PCI I/O and memory resources
2497  * @pdev: PCI device whose resources are to be reserved
2498  * @bars: Bitmask of BARs to be requested
2499  * @res_name: Name to be associated with resource
2500  */
2501 int pci_request_selected_regions(struct pci_dev *pdev, int bars,
2502 				 const char *res_name)
2503 {
2504 	return __pci_request_selected_regions(pdev, bars, res_name, 0);
2505 }
2506 
2507 int pci_request_selected_regions_exclusive(struct pci_dev *pdev,
2508 				 int bars, const char *res_name)
2509 {
2510 	return __pci_request_selected_regions(pdev, bars, res_name,
2511 			IORESOURCE_EXCLUSIVE);
2512 }
2513 
2514 /**
2515  *	pci_release_regions - Release reserved PCI I/O and memory resources
2516  *	@pdev: PCI device whose resources were previously reserved by pci_request_regions
2517  *
2518  *	Releases all PCI I/O and memory resources previously reserved by a
2519  *	successful call to pci_request_regions.  Call this function only
2520  *	after all use of the PCI regions has ceased.
2521  */
2522 
2523 void pci_release_regions(struct pci_dev *pdev)
2524 {
2525 	pci_release_selected_regions(pdev, (1 << 6) - 1);
2526 }
2527 
2528 /**
2529  *	pci_request_regions - Reserved PCI I/O and memory resources
2530  *	@pdev: PCI device whose resources are to be reserved
2531  *	@res_name: Name to be associated with resource.
2532  *
2533  *	Mark all PCI regions associated with PCI device @pdev as
2534  *	being reserved by owner @res_name.  Do not access any
2535  *	address inside the PCI regions unless this call returns
2536  *	successfully.
2537  *
2538  *	Returns 0 on success, or %EBUSY on error.  A warning
2539  *	message is also printed on failure.
2540  */
2541 int pci_request_regions(struct pci_dev *pdev, const char *res_name)
2542 {
2543 	return pci_request_selected_regions(pdev, ((1 << 6) - 1), res_name);
2544 }
2545 
2546 /**
2547  *	pci_request_regions_exclusive - Reserved PCI I/O and memory resources
2548  *	@pdev: PCI device whose resources are to be reserved
2549  *	@res_name: Name to be associated with resource.
2550  *
2551  *	Mark all PCI regions associated with PCI device @pdev as
2552  *	being reserved by owner @res_name.  Do not access any
2553  *	address inside the PCI regions unless this call returns
2554  *	successfully.
2555  *
2556  *	pci_request_regions_exclusive() will mark the region so that
2557  * 	/dev/mem and the sysfs MMIO access will not be allowed.
2558  *
2559  *	Returns 0 on success, or %EBUSY on error.  A warning
2560  *	message is also printed on failure.
2561  */
2562 int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name)
2563 {
2564 	return pci_request_selected_regions_exclusive(pdev,
2565 					((1 << 6) - 1), res_name);
2566 }
2567 
2568 static void __pci_set_master(struct pci_dev *dev, bool enable)
2569 {
2570 	u16 old_cmd, cmd;
2571 
2572 	pci_read_config_word(dev, PCI_COMMAND, &old_cmd);
2573 	if (enable)
2574 		cmd = old_cmd | PCI_COMMAND_MASTER;
2575 	else
2576 		cmd = old_cmd & ~PCI_COMMAND_MASTER;
2577 	if (cmd != old_cmd) {
2578 		dev_dbg(&dev->dev, "%s bus mastering\n",
2579 			enable ? "enabling" : "disabling");
2580 		pci_write_config_word(dev, PCI_COMMAND, cmd);
2581 	}
2582 	dev->is_busmaster = enable;
2583 }
2584 
2585 /**
2586  * pci_set_master - enables bus-mastering for device dev
2587  * @dev: the PCI device to enable
2588  *
2589  * Enables bus-mastering on the device and calls pcibios_set_master()
2590  * to do the needed arch specific settings.
2591  */
2592 void pci_set_master(struct pci_dev *dev)
2593 {
2594 	__pci_set_master(dev, true);
2595 	pcibios_set_master(dev);
2596 }
2597 
2598 /**
2599  * pci_clear_master - disables bus-mastering for device dev
2600  * @dev: the PCI device to disable
2601  */
2602 void pci_clear_master(struct pci_dev *dev)
2603 {
2604 	__pci_set_master(dev, false);
2605 }
2606 
2607 /**
2608  * pci_set_cacheline_size - ensure the CACHE_LINE_SIZE register is programmed
2609  * @dev: the PCI device for which MWI is to be enabled
2610  *
2611  * Helper function for pci_set_mwi.
2612  * Originally copied from drivers/net/acenic.c.
2613  * Copyright 1998-2001 by Jes Sorensen, <jes@trained-monkey.org>.
2614  *
2615  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2616  */
2617 int pci_set_cacheline_size(struct pci_dev *dev)
2618 {
2619 	u8 cacheline_size;
2620 
2621 	if (!pci_cache_line_size)
2622 		return -EINVAL;
2623 
2624 	/* Validate current setting: the PCI_CACHE_LINE_SIZE must be
2625 	   equal to or multiple of the right value. */
2626 	pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
2627 	if (cacheline_size >= pci_cache_line_size &&
2628 	    (cacheline_size % pci_cache_line_size) == 0)
2629 		return 0;
2630 
2631 	/* Write the correct value. */
2632 	pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, pci_cache_line_size);
2633 	/* Read it back. */
2634 	pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
2635 	if (cacheline_size == pci_cache_line_size)
2636 		return 0;
2637 
2638 	dev_printk(KERN_DEBUG, &dev->dev, "cache line size of %d is not "
2639 		   "supported\n", pci_cache_line_size << 2);
2640 
2641 	return -EINVAL;
2642 }
2643 EXPORT_SYMBOL_GPL(pci_set_cacheline_size);
2644 
2645 #ifdef PCI_DISABLE_MWI
2646 int pci_set_mwi(struct pci_dev *dev)
2647 {
2648 	return 0;
2649 }
2650 
2651 int pci_try_set_mwi(struct pci_dev *dev)
2652 {
2653 	return 0;
2654 }
2655 
2656 void pci_clear_mwi(struct pci_dev *dev)
2657 {
2658 }
2659 
2660 #else
2661 
2662 /**
2663  * pci_set_mwi - enables memory-write-invalidate PCI transaction
2664  * @dev: the PCI device for which MWI is enabled
2665  *
2666  * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND.
2667  *
2668  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2669  */
2670 int
2671 pci_set_mwi(struct pci_dev *dev)
2672 {
2673 	int rc;
2674 	u16 cmd;
2675 
2676 	rc = pci_set_cacheline_size(dev);
2677 	if (rc)
2678 		return rc;
2679 
2680 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
2681 	if (! (cmd & PCI_COMMAND_INVALIDATE)) {
2682 		dev_dbg(&dev->dev, "enabling Mem-Wr-Inval\n");
2683 		cmd |= PCI_COMMAND_INVALIDATE;
2684 		pci_write_config_word(dev, PCI_COMMAND, cmd);
2685 	}
2686 
2687 	return 0;
2688 }
2689 
2690 /**
2691  * pci_try_set_mwi - enables memory-write-invalidate PCI transaction
2692  * @dev: the PCI device for which MWI is enabled
2693  *
2694  * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND.
2695  * Callers are not required to check the return value.
2696  *
2697  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2698  */
2699 int pci_try_set_mwi(struct pci_dev *dev)
2700 {
2701 	int rc = pci_set_mwi(dev);
2702 	return rc;
2703 }
2704 
2705 /**
2706  * pci_clear_mwi - disables Memory-Write-Invalidate for device dev
2707  * @dev: the PCI device to disable
2708  *
2709  * Disables PCI Memory-Write-Invalidate transaction on the device
2710  */
2711 void
2712 pci_clear_mwi(struct pci_dev *dev)
2713 {
2714 	u16 cmd;
2715 
2716 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
2717 	if (cmd & PCI_COMMAND_INVALIDATE) {
2718 		cmd &= ~PCI_COMMAND_INVALIDATE;
2719 		pci_write_config_word(dev, PCI_COMMAND, cmd);
2720 	}
2721 }
2722 #endif /* ! PCI_DISABLE_MWI */
2723 
2724 /**
2725  * pci_intx - enables/disables PCI INTx for device dev
2726  * @pdev: the PCI device to operate on
2727  * @enable: boolean: whether to enable or disable PCI INTx
2728  *
2729  * Enables/disables PCI INTx for device dev
2730  */
2731 void
2732 pci_intx(struct pci_dev *pdev, int enable)
2733 {
2734 	u16 pci_command, new;
2735 
2736 	pci_read_config_word(pdev, PCI_COMMAND, &pci_command);
2737 
2738 	if (enable) {
2739 		new = pci_command & ~PCI_COMMAND_INTX_DISABLE;
2740 	} else {
2741 		new = pci_command | PCI_COMMAND_INTX_DISABLE;
2742 	}
2743 
2744 	if (new != pci_command) {
2745 		struct pci_devres *dr;
2746 
2747 		pci_write_config_word(pdev, PCI_COMMAND, new);
2748 
2749 		dr = find_pci_dr(pdev);
2750 		if (dr && !dr->restore_intx) {
2751 			dr->restore_intx = 1;
2752 			dr->orig_intx = !enable;
2753 		}
2754 	}
2755 }
2756 
2757 /**
2758  * pci_msi_off - disables any msi or msix capabilities
2759  * @dev: the PCI device to operate on
2760  *
2761  * If you want to use msi see pci_enable_msi and friends.
2762  * This is a lower level primitive that allows us to disable
2763  * msi operation at the device level.
2764  */
2765 void pci_msi_off(struct pci_dev *dev)
2766 {
2767 	int pos;
2768 	u16 control;
2769 
2770 	pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
2771 	if (pos) {
2772 		pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control);
2773 		control &= ~PCI_MSI_FLAGS_ENABLE;
2774 		pci_write_config_word(dev, pos + PCI_MSI_FLAGS, control);
2775 	}
2776 	pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
2777 	if (pos) {
2778 		pci_read_config_word(dev, pos + PCI_MSIX_FLAGS, &control);
2779 		control &= ~PCI_MSIX_FLAGS_ENABLE;
2780 		pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control);
2781 	}
2782 }
2783 EXPORT_SYMBOL_GPL(pci_msi_off);
2784 
2785 int pci_set_dma_max_seg_size(struct pci_dev *dev, unsigned int size)
2786 {
2787 	return dma_set_max_seg_size(&dev->dev, size);
2788 }
2789 EXPORT_SYMBOL(pci_set_dma_max_seg_size);
2790 
2791 int pci_set_dma_seg_boundary(struct pci_dev *dev, unsigned long mask)
2792 {
2793 	return dma_set_seg_boundary(&dev->dev, mask);
2794 }
2795 EXPORT_SYMBOL(pci_set_dma_seg_boundary);
2796 
2797 static int pcie_flr(struct pci_dev *dev, int probe)
2798 {
2799 	int i;
2800 	int pos;
2801 	u32 cap;
2802 	u16 status, control;
2803 
2804 	pos = pci_pcie_cap(dev);
2805 	if (!pos)
2806 		return -ENOTTY;
2807 
2808 	pci_read_config_dword(dev, pos + PCI_EXP_DEVCAP, &cap);
2809 	if (!(cap & PCI_EXP_DEVCAP_FLR))
2810 		return -ENOTTY;
2811 
2812 	if (probe)
2813 		return 0;
2814 
2815 	/* Wait for Transaction Pending bit clean */
2816 	for (i = 0; i < 4; i++) {
2817 		if (i)
2818 			msleep((1 << (i - 1)) * 100);
2819 
2820 		pci_read_config_word(dev, pos + PCI_EXP_DEVSTA, &status);
2821 		if (!(status & PCI_EXP_DEVSTA_TRPND))
2822 			goto clear;
2823 	}
2824 
2825 	dev_err(&dev->dev, "transaction is not cleared; "
2826 			"proceeding with reset anyway\n");
2827 
2828 clear:
2829 	pci_read_config_word(dev, pos + PCI_EXP_DEVCTL, &control);
2830 	control |= PCI_EXP_DEVCTL_BCR_FLR;
2831 	pci_write_config_word(dev, pos + PCI_EXP_DEVCTL, control);
2832 
2833 	msleep(100);
2834 
2835 	return 0;
2836 }
2837 
2838 static int pci_af_flr(struct pci_dev *dev, int probe)
2839 {
2840 	int i;
2841 	int pos;
2842 	u8 cap;
2843 	u8 status;
2844 
2845 	pos = pci_find_capability(dev, PCI_CAP_ID_AF);
2846 	if (!pos)
2847 		return -ENOTTY;
2848 
2849 	pci_read_config_byte(dev, pos + PCI_AF_CAP, &cap);
2850 	if (!(cap & PCI_AF_CAP_TP) || !(cap & PCI_AF_CAP_FLR))
2851 		return -ENOTTY;
2852 
2853 	if (probe)
2854 		return 0;
2855 
2856 	/* Wait for Transaction Pending bit clean */
2857 	for (i = 0; i < 4; i++) {
2858 		if (i)
2859 			msleep((1 << (i - 1)) * 100);
2860 
2861 		pci_read_config_byte(dev, pos + PCI_AF_STATUS, &status);
2862 		if (!(status & PCI_AF_STATUS_TP))
2863 			goto clear;
2864 	}
2865 
2866 	dev_err(&dev->dev, "transaction is not cleared; "
2867 			"proceeding with reset anyway\n");
2868 
2869 clear:
2870 	pci_write_config_byte(dev, pos + PCI_AF_CTRL, PCI_AF_CTRL_FLR);
2871 	msleep(100);
2872 
2873 	return 0;
2874 }
2875 
2876 /**
2877  * pci_pm_reset - Put device into PCI_D3 and back into PCI_D0.
2878  * @dev: Device to reset.
2879  * @probe: If set, only check if the device can be reset this way.
2880  *
2881  * If @dev supports native PCI PM and its PCI_PM_CTRL_NO_SOFT_RESET flag is
2882  * unset, it will be reinitialized internally when going from PCI_D3hot to
2883  * PCI_D0.  If that's the case and the device is not in a low-power state
2884  * already, force it into PCI_D3hot and back to PCI_D0, causing it to be reset.
2885  *
2886  * NOTE: This causes the caller to sleep for twice the device power transition
2887  * cooldown period, which for the D0->D3hot and D3hot->D0 transitions is 10 ms
2888  * by devault (i.e. unless the @dev's d3_delay field has a different value).
2889  * Moreover, only devices in D0 can be reset by this function.
2890  */
2891 static int pci_pm_reset(struct pci_dev *dev, int probe)
2892 {
2893 	u16 csr;
2894 
2895 	if (!dev->pm_cap)
2896 		return -ENOTTY;
2897 
2898 	pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &csr);
2899 	if (csr & PCI_PM_CTRL_NO_SOFT_RESET)
2900 		return -ENOTTY;
2901 
2902 	if (probe)
2903 		return 0;
2904 
2905 	if (dev->current_state != PCI_D0)
2906 		return -EINVAL;
2907 
2908 	csr &= ~PCI_PM_CTRL_STATE_MASK;
2909 	csr |= PCI_D3hot;
2910 	pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);
2911 	pci_dev_d3_sleep(dev);
2912 
2913 	csr &= ~PCI_PM_CTRL_STATE_MASK;
2914 	csr |= PCI_D0;
2915 	pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);
2916 	pci_dev_d3_sleep(dev);
2917 
2918 	return 0;
2919 }
2920 
2921 static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
2922 {
2923 	u16 ctrl;
2924 	struct pci_dev *pdev;
2925 
2926 	if (pci_is_root_bus(dev->bus) || dev->subordinate || !dev->bus->self)
2927 		return -ENOTTY;
2928 
2929 	list_for_each_entry(pdev, &dev->bus->devices, bus_list)
2930 		if (pdev != dev)
2931 			return -ENOTTY;
2932 
2933 	if (probe)
2934 		return 0;
2935 
2936 	pci_read_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, &ctrl);
2937 	ctrl |= PCI_BRIDGE_CTL_BUS_RESET;
2938 	pci_write_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, ctrl);
2939 	msleep(100);
2940 
2941 	ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET;
2942 	pci_write_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, ctrl);
2943 	msleep(100);
2944 
2945 	return 0;
2946 }
2947 
2948 static int pci_dev_reset(struct pci_dev *dev, int probe)
2949 {
2950 	int rc;
2951 
2952 	might_sleep();
2953 
2954 	if (!probe) {
2955 		pci_block_user_cfg_access(dev);
2956 		/* block PM suspend, driver probe, etc. */
2957 		device_lock(&dev->dev);
2958 	}
2959 
2960 	rc = pci_dev_specific_reset(dev, probe);
2961 	if (rc != -ENOTTY)
2962 		goto done;
2963 
2964 	rc = pcie_flr(dev, probe);
2965 	if (rc != -ENOTTY)
2966 		goto done;
2967 
2968 	rc = pci_af_flr(dev, probe);
2969 	if (rc != -ENOTTY)
2970 		goto done;
2971 
2972 	rc = pci_pm_reset(dev, probe);
2973 	if (rc != -ENOTTY)
2974 		goto done;
2975 
2976 	rc = pci_parent_bus_reset(dev, probe);
2977 done:
2978 	if (!probe) {
2979 		device_unlock(&dev->dev);
2980 		pci_unblock_user_cfg_access(dev);
2981 	}
2982 
2983 	return rc;
2984 }
2985 
2986 /**
2987  * __pci_reset_function - reset a PCI device function
2988  * @dev: PCI device to reset
2989  *
2990  * Some devices allow an individual function to be reset without affecting
2991  * other functions in the same device.  The PCI device must be responsive
2992  * to PCI config space in order to use this function.
2993  *
2994  * The device function is presumed to be unused when this function is called.
2995  * Resetting the device will make the contents of PCI configuration space
2996  * random, so any caller of this must be prepared to reinitialise the
2997  * device including MSI, bus mastering, BARs, decoding IO and memory spaces,
2998  * etc.
2999  *
3000  * Returns 0 if the device function was successfully reset or negative if the
3001  * device doesn't support resetting a single function.
3002  */
3003 int __pci_reset_function(struct pci_dev *dev)
3004 {
3005 	return pci_dev_reset(dev, 0);
3006 }
3007 EXPORT_SYMBOL_GPL(__pci_reset_function);
3008 
3009 /**
3010  * pci_probe_reset_function - check whether the device can be safely reset
3011  * @dev: PCI device to reset
3012  *
3013  * Some devices allow an individual function to be reset without affecting
3014  * other functions in the same device.  The PCI device must be responsive
3015  * to PCI config space in order to use this function.
3016  *
3017  * Returns 0 if the device function can be reset or negative if the
3018  * device doesn't support resetting a single function.
3019  */
3020 int pci_probe_reset_function(struct pci_dev *dev)
3021 {
3022 	return pci_dev_reset(dev, 1);
3023 }
3024 
3025 /**
3026  * pci_reset_function - quiesce and reset a PCI device function
3027  * @dev: PCI device to reset
3028  *
3029  * Some devices allow an individual function to be reset without affecting
3030  * other functions in the same device.  The PCI device must be responsive
3031  * to PCI config space in order to use this function.
3032  *
3033  * This function does not just reset the PCI portion of a device, but
3034  * clears all the state associated with the device.  This function differs
3035  * from __pci_reset_function in that it saves and restores device state
3036  * over the reset.
3037  *
3038  * Returns 0 if the device function was successfully reset or negative if the
3039  * device doesn't support resetting a single function.
3040  */
3041 int pci_reset_function(struct pci_dev *dev)
3042 {
3043 	int rc;
3044 
3045 	rc = pci_dev_reset(dev, 1);
3046 	if (rc)
3047 		return rc;
3048 
3049 	pci_save_state(dev);
3050 
3051 	/*
3052 	 * both INTx and MSI are disabled after the Interrupt Disable bit
3053 	 * is set and the Bus Master bit is cleared.
3054 	 */
3055 	pci_write_config_word(dev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
3056 
3057 	rc = pci_dev_reset(dev, 0);
3058 
3059 	pci_restore_state(dev);
3060 
3061 	return rc;
3062 }
3063 EXPORT_SYMBOL_GPL(pci_reset_function);
3064 
3065 /**
3066  * pcix_get_max_mmrbc - get PCI-X maximum designed memory read byte count
3067  * @dev: PCI device to query
3068  *
3069  * Returns mmrbc: maximum designed memory read count in bytes
3070  *    or appropriate error value.
3071  */
3072 int pcix_get_max_mmrbc(struct pci_dev *dev)
3073 {
3074 	int cap;
3075 	u32 stat;
3076 
3077 	cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
3078 	if (!cap)
3079 		return -EINVAL;
3080 
3081 	if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat))
3082 		return -EINVAL;
3083 
3084 	return 512 << ((stat & PCI_X_STATUS_MAX_READ) >> 21);
3085 }
3086 EXPORT_SYMBOL(pcix_get_max_mmrbc);
3087 
3088 /**
3089  * pcix_get_mmrbc - get PCI-X maximum memory read byte count
3090  * @dev: PCI device to query
3091  *
3092  * Returns mmrbc: maximum memory read count in bytes
3093  *    or appropriate error value.
3094  */
3095 int pcix_get_mmrbc(struct pci_dev *dev)
3096 {
3097 	int cap;
3098 	u16 cmd;
3099 
3100 	cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
3101 	if (!cap)
3102 		return -EINVAL;
3103 
3104 	if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd))
3105 		return -EINVAL;
3106 
3107 	return 512 << ((cmd & PCI_X_CMD_MAX_READ) >> 2);
3108 }
3109 EXPORT_SYMBOL(pcix_get_mmrbc);
3110 
3111 /**
3112  * pcix_set_mmrbc - set PCI-X maximum memory read byte count
3113  * @dev: PCI device to query
3114  * @mmrbc: maximum memory read count in bytes
3115  *    valid values are 512, 1024, 2048, 4096
3116  *
3117  * If possible sets maximum memory read byte count, some bridges have erratas
3118  * that prevent this.
3119  */
3120 int pcix_set_mmrbc(struct pci_dev *dev, int mmrbc)
3121 {
3122 	int cap;
3123 	u32 stat, v, o;
3124 	u16 cmd;
3125 
3126 	if (mmrbc < 512 || mmrbc > 4096 || !is_power_of_2(mmrbc))
3127 		return -EINVAL;
3128 
3129 	v = ffs(mmrbc) - 10;
3130 
3131 	cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
3132 	if (!cap)
3133 		return -EINVAL;
3134 
3135 	if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat))
3136 		return -EINVAL;
3137 
3138 	if (v > (stat & PCI_X_STATUS_MAX_READ) >> 21)
3139 		return -E2BIG;
3140 
3141 	if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd))
3142 		return -EINVAL;
3143 
3144 	o = (cmd & PCI_X_CMD_MAX_READ) >> 2;
3145 	if (o != v) {
3146 		if (v > o && dev->bus &&
3147 		   (dev->bus->bus_flags & PCI_BUS_FLAGS_NO_MMRBC))
3148 			return -EIO;
3149 
3150 		cmd &= ~PCI_X_CMD_MAX_READ;
3151 		cmd |= v << 2;
3152 		if (pci_write_config_word(dev, cap + PCI_X_CMD, cmd))
3153 			return -EIO;
3154 	}
3155 	return 0;
3156 }
3157 EXPORT_SYMBOL(pcix_set_mmrbc);
3158 
3159 /**
3160  * pcie_get_readrq - get PCI Express read request size
3161  * @dev: PCI device to query
3162  *
3163  * Returns maximum memory read request in bytes
3164  *    or appropriate error value.
3165  */
3166 int pcie_get_readrq(struct pci_dev *dev)
3167 {
3168 	int ret, cap;
3169 	u16 ctl;
3170 
3171 	cap = pci_pcie_cap(dev);
3172 	if (!cap)
3173 		return -EINVAL;
3174 
3175 	ret = pci_read_config_word(dev, cap + PCI_EXP_DEVCTL, &ctl);
3176 	if (!ret)
3177 		ret = 128 << ((ctl & PCI_EXP_DEVCTL_READRQ) >> 12);
3178 
3179 	return ret;
3180 }
3181 EXPORT_SYMBOL(pcie_get_readrq);
3182 
3183 /**
3184  * pcie_set_readrq - set PCI Express maximum memory read request
3185  * @dev: PCI device to query
3186  * @rq: maximum memory read count in bytes
3187  *    valid values are 128, 256, 512, 1024, 2048, 4096
3188  *
3189  * If possible sets maximum read byte count
3190  */
3191 int pcie_set_readrq(struct pci_dev *dev, int rq)
3192 {
3193 	int cap, err = -EINVAL;
3194 	u16 ctl, v;
3195 
3196 	if (rq < 128 || rq > 4096 || !is_power_of_2(rq))
3197 		goto out;
3198 
3199 	v = (ffs(rq) - 8) << 12;
3200 
3201 	cap = pci_pcie_cap(dev);
3202 	if (!cap)
3203 		goto out;
3204 
3205 	err = pci_read_config_word(dev, cap + PCI_EXP_DEVCTL, &ctl);
3206 	if (err)
3207 		goto out;
3208 
3209 	if ((ctl & PCI_EXP_DEVCTL_READRQ) != v) {
3210 		ctl &= ~PCI_EXP_DEVCTL_READRQ;
3211 		ctl |= v;
3212 		err = pci_write_config_dword(dev, cap + PCI_EXP_DEVCTL, ctl);
3213 	}
3214 
3215 out:
3216 	return err;
3217 }
3218 EXPORT_SYMBOL(pcie_set_readrq);
3219 
3220 /**
3221  * pci_select_bars - Make BAR mask from the type of resource
3222  * @dev: the PCI device for which BAR mask is made
3223  * @flags: resource type mask to be selected
3224  *
3225  * This helper routine makes bar mask from the type of resource.
3226  */
3227 int pci_select_bars(struct pci_dev *dev, unsigned long flags)
3228 {
3229 	int i, bars = 0;
3230 	for (i = 0; i < PCI_NUM_RESOURCES; i++)
3231 		if (pci_resource_flags(dev, i) & flags)
3232 			bars |= (1 << i);
3233 	return bars;
3234 }
3235 
3236 /**
3237  * pci_resource_bar - get position of the BAR associated with a resource
3238  * @dev: the PCI device
3239  * @resno: the resource number
3240  * @type: the BAR type to be filled in
3241  *
3242  * Returns BAR position in config space, or 0 if the BAR is invalid.
3243  */
3244 int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type)
3245 {
3246 	int reg;
3247 
3248 	if (resno < PCI_ROM_RESOURCE) {
3249 		*type = pci_bar_unknown;
3250 		return PCI_BASE_ADDRESS_0 + 4 * resno;
3251 	} else if (resno == PCI_ROM_RESOURCE) {
3252 		*type = pci_bar_mem32;
3253 		return dev->rom_base_reg;
3254 	} else if (resno < PCI_BRIDGE_RESOURCES) {
3255 		/* device specific resource */
3256 		reg = pci_iov_resource_bar(dev, resno, type);
3257 		if (reg)
3258 			return reg;
3259 	}
3260 
3261 	dev_err(&dev->dev, "BAR %d: invalid resource\n", resno);
3262 	return 0;
3263 }
3264 
3265 /* Some architectures require additional programming to enable VGA */
3266 static arch_set_vga_state_t arch_set_vga_state;
3267 
3268 void __init pci_register_set_vga_state(arch_set_vga_state_t func)
3269 {
3270 	arch_set_vga_state = func;	/* NULL disables */
3271 }
3272 
3273 static int pci_set_vga_state_arch(struct pci_dev *dev, bool decode,
3274 		      unsigned int command_bits, u32 flags)
3275 {
3276 	if (arch_set_vga_state)
3277 		return arch_set_vga_state(dev, decode, command_bits,
3278 						flags);
3279 	return 0;
3280 }
3281 
3282 /**
3283  * pci_set_vga_state - set VGA decode state on device and parents if requested
3284  * @dev: the PCI device
3285  * @decode: true = enable decoding, false = disable decoding
3286  * @command_bits: PCI_COMMAND_IO and/or PCI_COMMAND_MEMORY
3287  * @flags: traverse ancestors and change bridges
3288  * CHANGE_BRIDGE_ONLY / CHANGE_BRIDGE
3289  */
3290 int pci_set_vga_state(struct pci_dev *dev, bool decode,
3291 		      unsigned int command_bits, u32 flags)
3292 {
3293 	struct pci_bus *bus;
3294 	struct pci_dev *bridge;
3295 	u16 cmd;
3296 	int rc;
3297 
3298 	WARN_ON((flags & PCI_VGA_STATE_CHANGE_DECODES) & (command_bits & ~(PCI_COMMAND_IO|PCI_COMMAND_MEMORY)));
3299 
3300 	/* ARCH specific VGA enables */
3301 	rc = pci_set_vga_state_arch(dev, decode, command_bits, flags);
3302 	if (rc)
3303 		return rc;
3304 
3305 	if (flags & PCI_VGA_STATE_CHANGE_DECODES) {
3306 		pci_read_config_word(dev, PCI_COMMAND, &cmd);
3307 		if (decode == true)
3308 			cmd |= command_bits;
3309 		else
3310 			cmd &= ~command_bits;
3311 		pci_write_config_word(dev, PCI_COMMAND, cmd);
3312 	}
3313 
3314 	if (!(flags & PCI_VGA_STATE_CHANGE_BRIDGE))
3315 		return 0;
3316 
3317 	bus = dev->bus;
3318 	while (bus) {
3319 		bridge = bus->self;
3320 		if (bridge) {
3321 			pci_read_config_word(bridge, PCI_BRIDGE_CONTROL,
3322 					     &cmd);
3323 			if (decode == true)
3324 				cmd |= PCI_BRIDGE_CTL_VGA;
3325 			else
3326 				cmd &= ~PCI_BRIDGE_CTL_VGA;
3327 			pci_write_config_word(bridge, PCI_BRIDGE_CONTROL,
3328 					      cmd);
3329 		}
3330 		bus = bus->parent;
3331 	}
3332 	return 0;
3333 }
3334 
3335 #define RESOURCE_ALIGNMENT_PARAM_SIZE COMMAND_LINE_SIZE
3336 static char resource_alignment_param[RESOURCE_ALIGNMENT_PARAM_SIZE] = {0};
3337 static DEFINE_SPINLOCK(resource_alignment_lock);
3338 
3339 /**
3340  * pci_specified_resource_alignment - get resource alignment specified by user.
3341  * @dev: the PCI device to get
3342  *
3343  * RETURNS: Resource alignment if it is specified.
3344  *          Zero if it is not specified.
3345  */
3346 resource_size_t pci_specified_resource_alignment(struct pci_dev *dev)
3347 {
3348 	int seg, bus, slot, func, align_order, count;
3349 	resource_size_t align = 0;
3350 	char *p;
3351 
3352 	spin_lock(&resource_alignment_lock);
3353 	p = resource_alignment_param;
3354 	while (*p) {
3355 		count = 0;
3356 		if (sscanf(p, "%d%n", &align_order, &count) == 1 &&
3357 							p[count] == '@') {
3358 			p += count + 1;
3359 		} else {
3360 			align_order = -1;
3361 		}
3362 		if (sscanf(p, "%x:%x:%x.%x%n",
3363 			&seg, &bus, &slot, &func, &count) != 4) {
3364 			seg = 0;
3365 			if (sscanf(p, "%x:%x.%x%n",
3366 					&bus, &slot, &func, &count) != 3) {
3367 				/* Invalid format */
3368 				printk(KERN_ERR "PCI: Can't parse resource_alignment parameter: %s\n",
3369 					p);
3370 				break;
3371 			}
3372 		}
3373 		p += count;
3374 		if (seg == pci_domain_nr(dev->bus) &&
3375 			bus == dev->bus->number &&
3376 			slot == PCI_SLOT(dev->devfn) &&
3377 			func == PCI_FUNC(dev->devfn)) {
3378 			if (align_order == -1) {
3379 				align = PAGE_SIZE;
3380 			} else {
3381 				align = 1 << align_order;
3382 			}
3383 			/* Found */
3384 			break;
3385 		}
3386 		if (*p != ';' && *p != ',') {
3387 			/* End of param or invalid format */
3388 			break;
3389 		}
3390 		p++;
3391 	}
3392 	spin_unlock(&resource_alignment_lock);
3393 	return align;
3394 }
3395 
3396 /**
3397  * pci_is_reassigndev - check if specified PCI is target device to reassign
3398  * @dev: the PCI device to check
3399  *
3400  * RETURNS: non-zero for PCI device is a target device to reassign,
3401  *          or zero is not.
3402  */
3403 int pci_is_reassigndev(struct pci_dev *dev)
3404 {
3405 	return (pci_specified_resource_alignment(dev) != 0);
3406 }
3407 
3408 ssize_t pci_set_resource_alignment_param(const char *buf, size_t count)
3409 {
3410 	if (count > RESOURCE_ALIGNMENT_PARAM_SIZE - 1)
3411 		count = RESOURCE_ALIGNMENT_PARAM_SIZE - 1;
3412 	spin_lock(&resource_alignment_lock);
3413 	strncpy(resource_alignment_param, buf, count);
3414 	resource_alignment_param[count] = '\0';
3415 	spin_unlock(&resource_alignment_lock);
3416 	return count;
3417 }
3418 
3419 ssize_t pci_get_resource_alignment_param(char *buf, size_t size)
3420 {
3421 	size_t count;
3422 	spin_lock(&resource_alignment_lock);
3423 	count = snprintf(buf, size, "%s", resource_alignment_param);
3424 	spin_unlock(&resource_alignment_lock);
3425 	return count;
3426 }
3427 
3428 static ssize_t pci_resource_alignment_show(struct bus_type *bus, char *buf)
3429 {
3430 	return pci_get_resource_alignment_param(buf, PAGE_SIZE);
3431 }
3432 
3433 static ssize_t pci_resource_alignment_store(struct bus_type *bus,
3434 					const char *buf, size_t count)
3435 {
3436 	return pci_set_resource_alignment_param(buf, count);
3437 }
3438 
3439 BUS_ATTR(resource_alignment, 0644, pci_resource_alignment_show,
3440 					pci_resource_alignment_store);
3441 
3442 static int __init pci_resource_alignment_sysfs_init(void)
3443 {
3444 	return bus_create_file(&pci_bus_type,
3445 					&bus_attr_resource_alignment);
3446 }
3447 
3448 late_initcall(pci_resource_alignment_sysfs_init);
3449 
3450 static void __devinit pci_no_domains(void)
3451 {
3452 #ifdef CONFIG_PCI_DOMAINS
3453 	pci_domains_supported = 0;
3454 #endif
3455 }
3456 
3457 /**
3458  * pci_ext_cfg_enabled - can we access extended PCI config space?
3459  * @dev: The PCI device of the root bridge.
3460  *
3461  * Returns 1 if we can access PCI extended config space (offsets
3462  * greater than 0xff). This is the default implementation. Architecture
3463  * implementations can override this.
3464  */
3465 int __attribute__ ((weak)) pci_ext_cfg_avail(struct pci_dev *dev)
3466 {
3467 	return 1;
3468 }
3469 
3470 void __weak pci_fixup_cardbus(struct pci_bus *bus)
3471 {
3472 }
3473 EXPORT_SYMBOL(pci_fixup_cardbus);
3474 
3475 static int __init pci_setup(char *str)
3476 {
3477 	while (str) {
3478 		char *k = strchr(str, ',');
3479 		if (k)
3480 			*k++ = 0;
3481 		if (*str && (str = pcibios_setup(str)) && *str) {
3482 			if (!strcmp(str, "nomsi")) {
3483 				pci_no_msi();
3484 			} else if (!strcmp(str, "noaer")) {
3485 				pci_no_aer();
3486 			} else if (!strncmp(str, "realloc", 7)) {
3487 				pci_realloc();
3488 			} else if (!strcmp(str, "nodomains")) {
3489 				pci_no_domains();
3490 			} else if (!strncmp(str, "cbiosize=", 9)) {
3491 				pci_cardbus_io_size = memparse(str + 9, &str);
3492 			} else if (!strncmp(str, "cbmemsize=", 10)) {
3493 				pci_cardbus_mem_size = memparse(str + 10, &str);
3494 			} else if (!strncmp(str, "resource_alignment=", 19)) {
3495 				pci_set_resource_alignment_param(str + 19,
3496 							strlen(str + 19));
3497 			} else if (!strncmp(str, "ecrc=", 5)) {
3498 				pcie_ecrc_get_policy(str + 5);
3499 			} else if (!strncmp(str, "hpiosize=", 9)) {
3500 				pci_hotplug_io_size = memparse(str + 9, &str);
3501 			} else if (!strncmp(str, "hpmemsize=", 10)) {
3502 				pci_hotplug_mem_size = memparse(str + 10, &str);
3503 			} else {
3504 				printk(KERN_ERR "PCI: Unknown option `%s'\n",
3505 						str);
3506 			}
3507 		}
3508 		str = k;
3509 	}
3510 	return 0;
3511 }
3512 early_param("pci", pci_setup);
3513 
3514 EXPORT_SYMBOL(pci_reenable_device);
3515 EXPORT_SYMBOL(pci_enable_device_io);
3516 EXPORT_SYMBOL(pci_enable_device_mem);
3517 EXPORT_SYMBOL(pci_enable_device);
3518 EXPORT_SYMBOL(pcim_enable_device);
3519 EXPORT_SYMBOL(pcim_pin_device);
3520 EXPORT_SYMBOL(pci_disable_device);
3521 EXPORT_SYMBOL(pci_find_capability);
3522 EXPORT_SYMBOL(pci_bus_find_capability);
3523 EXPORT_SYMBOL(pci_release_regions);
3524 EXPORT_SYMBOL(pci_request_regions);
3525 EXPORT_SYMBOL(pci_request_regions_exclusive);
3526 EXPORT_SYMBOL(pci_release_region);
3527 EXPORT_SYMBOL(pci_request_region);
3528 EXPORT_SYMBOL(pci_request_region_exclusive);
3529 EXPORT_SYMBOL(pci_release_selected_regions);
3530 EXPORT_SYMBOL(pci_request_selected_regions);
3531 EXPORT_SYMBOL(pci_request_selected_regions_exclusive);
3532 EXPORT_SYMBOL(pci_set_master);
3533 EXPORT_SYMBOL(pci_clear_master);
3534 EXPORT_SYMBOL(pci_set_mwi);
3535 EXPORT_SYMBOL(pci_try_set_mwi);
3536 EXPORT_SYMBOL(pci_clear_mwi);
3537 EXPORT_SYMBOL_GPL(pci_intx);
3538 EXPORT_SYMBOL(pci_assign_resource);
3539 EXPORT_SYMBOL(pci_find_parent_resource);
3540 EXPORT_SYMBOL(pci_select_bars);
3541 
3542 EXPORT_SYMBOL(pci_set_power_state);
3543 EXPORT_SYMBOL(pci_save_state);
3544 EXPORT_SYMBOL(pci_restore_state);
3545 EXPORT_SYMBOL(pci_pme_capable);
3546 EXPORT_SYMBOL(pci_pme_active);
3547 EXPORT_SYMBOL(pci_wake_from_d3);
3548 EXPORT_SYMBOL(pci_target_state);
3549 EXPORT_SYMBOL(pci_prepare_to_sleep);
3550 EXPORT_SYMBOL(pci_back_from_sleep);
3551 EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state);
3552