xref: /linux/drivers/pci/pci.c (revision d67b569f5f620c0fb95d5212642746b7ba9d29e4)
1 /*
2  *	$Id: pci.c,v 1.91 1999/01/21 13:34:01 davem Exp $
3  *
4  *	PCI Bus Services, see include/linux/pci.h for further explanation.
5  *
6  *	Copyright 1993 -- 1997 Drew Eckhardt, Frederic Potter,
7  *	David Mosberger-Tang
8  *
9  *	Copyright 1997 -- 2000 Martin Mares <mj@ucw.cz>
10  */
11 
12 #include <linux/kernel.h>
13 #include <linux/delay.h>
14 #include <linux/init.h>
15 #include <linux/pci.h>
16 #include <linux/module.h>
17 #include <linux/spinlock.h>
18 #include <asm/dma.h>	/* isa_dma_bridge_buggy */
19 #include "pci.h"
20 
21 
22 /**
23  * pci_bus_max_busnr - returns maximum PCI bus number of given bus' children
24  * @bus: pointer to PCI bus structure to search
25  *
26  * Given a PCI bus, returns the highest PCI bus number present in the set
27  * including the given PCI bus and its list of child PCI buses.
28  */
29 unsigned char __devinit
30 pci_bus_max_busnr(struct pci_bus* bus)
31 {
32 	struct list_head *tmp;
33 	unsigned char max, n;
34 
35 	max = bus->number;
36 	list_for_each(tmp, &bus->children) {
37 		n = pci_bus_max_busnr(pci_bus_b(tmp));
38 		if(n > max)
39 			max = n;
40 	}
41 	return max;
42 }
43 
44 /**
45  * pci_max_busnr - returns maximum PCI bus number
46  *
47  * Returns the highest PCI bus number present in the system global list of
48  * PCI buses.
49  */
50 unsigned char __devinit
51 pci_max_busnr(void)
52 {
53 	struct pci_bus *bus = NULL;
54 	unsigned char max, n;
55 
56 	max = 0;
57 	while ((bus = pci_find_next_bus(bus)) != NULL) {
58 		n = pci_bus_max_busnr(bus);
59 		if(n > max)
60 			max = n;
61 	}
62 	return max;
63 }
64 
65 static int __pci_bus_find_cap(struct pci_bus *bus, unsigned int devfn, u8 hdr_type, int cap)
66 {
67 	u16 status;
68 	u8 pos, id;
69 	int ttl = 48;
70 
71 	pci_bus_read_config_word(bus, devfn, PCI_STATUS, &status);
72 	if (!(status & PCI_STATUS_CAP_LIST))
73 		return 0;
74 
75 	switch (hdr_type) {
76 	case PCI_HEADER_TYPE_NORMAL:
77 	case PCI_HEADER_TYPE_BRIDGE:
78 		pci_bus_read_config_byte(bus, devfn, PCI_CAPABILITY_LIST, &pos);
79 		break;
80 	case PCI_HEADER_TYPE_CARDBUS:
81 		pci_bus_read_config_byte(bus, devfn, PCI_CB_CAPABILITY_LIST, &pos);
82 		break;
83 	default:
84 		return 0;
85 	}
86 	while (ttl-- && pos >= 0x40) {
87 		pos &= ~3;
88 		pci_bus_read_config_byte(bus, devfn, pos + PCI_CAP_LIST_ID, &id);
89 		if (id == 0xff)
90 			break;
91 		if (id == cap)
92 			return pos;
93 		pci_bus_read_config_byte(bus, devfn, pos + PCI_CAP_LIST_NEXT, &pos);
94 	}
95 	return 0;
96 }
97 
98 /**
99  * pci_find_capability - query for devices' capabilities
100  * @dev: PCI device to query
101  * @cap: capability code
102  *
103  * Tell if a device supports a given PCI capability.
104  * Returns the address of the requested capability structure within the
105  * device's PCI configuration space or 0 in case the device does not
106  * support it.  Possible values for @cap:
107  *
108  *  %PCI_CAP_ID_PM           Power Management
109  *  %PCI_CAP_ID_AGP          Accelerated Graphics Port
110  *  %PCI_CAP_ID_VPD          Vital Product Data
111  *  %PCI_CAP_ID_SLOTID       Slot Identification
112  *  %PCI_CAP_ID_MSI          Message Signalled Interrupts
113  *  %PCI_CAP_ID_CHSWP        CompactPCI HotSwap
114  *  %PCI_CAP_ID_PCIX         PCI-X
115  *  %PCI_CAP_ID_EXP          PCI Express
116  */
117 int pci_find_capability(struct pci_dev *dev, int cap)
118 {
119 	return __pci_bus_find_cap(dev->bus, dev->devfn, dev->hdr_type, cap);
120 }
121 
122 /**
123  * pci_bus_find_capability - query for devices' capabilities
124  * @bus:   the PCI bus to query
125  * @devfn: PCI device to query
126  * @cap:   capability code
127  *
128  * Like pci_find_capability() but works for pci devices that do not have a
129  * pci_dev structure set up yet.
130  *
131  * Returns the address of the requested capability structure within the
132  * device's PCI configuration space or 0 in case the device does not
133  * support it.
134  */
135 int pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap)
136 {
137 	u8 hdr_type;
138 
139 	pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &hdr_type);
140 
141 	return __pci_bus_find_cap(bus, devfn, hdr_type & 0x7f, cap);
142 }
143 
144 /**
145  * pci_find_ext_capability - Find an extended capability
146  * @dev: PCI device to query
147  * @cap: capability code
148  *
149  * Returns the address of the requested extended capability structure
150  * within the device's PCI configuration space or 0 if the device does
151  * not support it.  Possible values for @cap:
152  *
153  *  %PCI_EXT_CAP_ID_ERR		Advanced Error Reporting
154  *  %PCI_EXT_CAP_ID_VC		Virtual Channel
155  *  %PCI_EXT_CAP_ID_DSN		Device Serial Number
156  *  %PCI_EXT_CAP_ID_PWR		Power Budgeting
157  */
158 int pci_find_ext_capability(struct pci_dev *dev, int cap)
159 {
160 	u32 header;
161 	int ttl = 480; /* 3840 bytes, minimum 8 bytes per capability */
162 	int pos = 0x100;
163 
164 	if (dev->cfg_size <= 256)
165 		return 0;
166 
167 	if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
168 		return 0;
169 
170 	/*
171 	 * If we have no capabilities, this is indicated by cap ID,
172 	 * cap version and next pointer all being 0.
173 	 */
174 	if (header == 0)
175 		return 0;
176 
177 	while (ttl-- > 0) {
178 		if (PCI_EXT_CAP_ID(header) == cap)
179 			return pos;
180 
181 		pos = PCI_EXT_CAP_NEXT(header);
182 		if (pos < 0x100)
183 			break;
184 
185 		if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
186 			break;
187 	}
188 
189 	return 0;
190 }
191 
192 /**
193  * pci_find_parent_resource - return resource region of parent bus of given region
194  * @dev: PCI device structure contains resources to be searched
195  * @res: child resource record for which parent is sought
196  *
197  *  For given resource region of given device, return the resource
198  *  region of parent bus the given region is contained in or where
199  *  it should be allocated from.
200  */
201 struct resource *
202 pci_find_parent_resource(const struct pci_dev *dev, struct resource *res)
203 {
204 	const struct pci_bus *bus = dev->bus;
205 	int i;
206 	struct resource *best = NULL;
207 
208 	for(i = 0; i < PCI_BUS_NUM_RESOURCES; i++) {
209 		struct resource *r = bus->resource[i];
210 		if (!r)
211 			continue;
212 		if (res->start && !(res->start >= r->start && res->end <= r->end))
213 			continue;	/* Not contained */
214 		if ((res->flags ^ r->flags) & (IORESOURCE_IO | IORESOURCE_MEM))
215 			continue;	/* Wrong type */
216 		if (!((res->flags ^ r->flags) & IORESOURCE_PREFETCH))
217 			return r;	/* Exact match */
218 		if ((res->flags & IORESOURCE_PREFETCH) && !(r->flags & IORESOURCE_PREFETCH))
219 			best = r;	/* Approximating prefetchable by non-prefetchable */
220 	}
221 	return best;
222 }
223 
224 /**
225  * pci_set_power_state - Set the power state of a PCI device
226  * @dev: PCI device to be suspended
227  * @state: PCI power state (D0, D1, D2, D3hot, D3cold) we're entering
228  *
229  * Transition a device to a new power state, using the Power Management
230  * Capabilities in the device's config space.
231  *
232  * RETURN VALUE:
233  * -EINVAL if trying to enter a lower state than we're already in.
234  * 0 if we're already in the requested state.
235  * -EIO if device does not support PCI PM.
236  * 0 if we can successfully change the power state.
237  */
238 
239 int
240 pci_set_power_state(struct pci_dev *dev, pci_power_t state)
241 {
242 	int pm;
243 	u16 pmcsr, pmc;
244 
245 	/* bound the state we're entering */
246 	if (state > PCI_D3hot)
247 		state = PCI_D3hot;
248 
249 	/* Validate current state:
250 	 * Can enter D0 from any state, but if we can only go deeper
251 	 * to sleep if we're already in a low power state
252 	 */
253 	if (state != PCI_D0 && dev->current_state > state)
254 		return -EINVAL;
255 	else if (dev->current_state == state)
256 		return 0;        /* we're already there */
257 
258 	/* find PCI PM capability in list */
259 	pm = pci_find_capability(dev, PCI_CAP_ID_PM);
260 
261 	/* abort if the device doesn't support PM capabilities */
262 	if (!pm)
263 		return -EIO;
264 
265 	pci_read_config_word(dev,pm + PCI_PM_PMC,&pmc);
266 	if ((pmc & PCI_PM_CAP_VER_MASK) > 2) {
267 		printk(KERN_DEBUG
268 		       "PCI: %s has unsupported PM cap regs version (%u)\n",
269 		       pci_name(dev), pmc & PCI_PM_CAP_VER_MASK);
270 		return -EIO;
271 	}
272 
273 	/* check if this device supports the desired state */
274 	if (state == PCI_D1 || state == PCI_D2) {
275 		if (state == PCI_D1 && !(pmc & PCI_PM_CAP_D1))
276 			return -EIO;
277 		else if (state == PCI_D2 && !(pmc & PCI_PM_CAP_D2))
278 			return -EIO;
279 	}
280 
281 	/* If we're in D3, force entire word to 0.
282 	 * This doesn't affect PME_Status, disables PME_En, and
283 	 * sets PowerState to 0.
284 	 */
285 	if (dev->current_state >= PCI_D3hot)
286 		pmcsr = 0;
287 	else {
288 		pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr);
289 		pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
290 		pmcsr |= state;
291 	}
292 
293 	/* enter specified state */
294 	pci_write_config_word(dev, pm + PCI_PM_CTRL, pmcsr);
295 
296 	/* Mandatory power management transition delays */
297 	/* see PCI PM 1.1 5.6.1 table 18 */
298 	if (state == PCI_D3hot || dev->current_state == PCI_D3hot)
299 		msleep(10);
300 	else if (state == PCI_D2 || dev->current_state == PCI_D2)
301 		udelay(200);
302 	dev->current_state = state;
303 
304 	return 0;
305 }
306 
307 /**
308  * pci_choose_state - Choose the power state of a PCI device
309  * @dev: PCI device to be suspended
310  * @state: target sleep state for the whole system. This is the value
311  *	that is passed to suspend() function.
312  *
313  * Returns PCI power state suitable for given device and given system
314  * message.
315  */
316 
317 pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state)
318 {
319 	if (!pci_find_capability(dev, PCI_CAP_ID_PM))
320 		return PCI_D0;
321 
322 	switch (state) {
323 	case 0: return PCI_D0;
324 	case 3: return PCI_D3hot;
325 	default:
326 		printk("They asked me for state %d\n", state);
327 		BUG();
328 	}
329 	return PCI_D0;
330 }
331 
332 EXPORT_SYMBOL(pci_choose_state);
333 
334 /**
335  * pci_save_state - save the PCI configuration space of a device before suspending
336  * @dev: - PCI device that we're dealing with
337  */
338 int
339 pci_save_state(struct pci_dev *dev)
340 {
341 	int i;
342 	/* XXX: 100% dword access ok here? */
343 	for (i = 0; i < 16; i++)
344 		pci_read_config_dword(dev, i * 4,&dev->saved_config_space[i]);
345 	return 0;
346 }
347 
348 /**
349  * pci_restore_state - Restore the saved state of a PCI device
350  * @dev: - PCI device that we're dealing with
351  */
352 int
353 pci_restore_state(struct pci_dev *dev)
354 {
355 	int i;
356 
357 	for (i = 0; i < 16; i++)
358 		pci_write_config_dword(dev,i * 4, dev->saved_config_space[i]);
359 	return 0;
360 }
361 
362 /**
363  * pci_enable_device_bars - Initialize some of a device for use
364  * @dev: PCI device to be initialized
365  * @bars: bitmask of BAR's that must be configured
366  *
367  *  Initialize device before it's used by a driver. Ask low-level code
368  *  to enable selected I/O and memory resources. Wake up the device if it
369  *  was suspended. Beware, this function can fail.
370  */
371 
372 int
373 pci_enable_device_bars(struct pci_dev *dev, int bars)
374 {
375 	int err;
376 
377 	pci_set_power_state(dev, PCI_D0);
378 	if ((err = pcibios_enable_device(dev, bars)) < 0)
379 		return err;
380 	return 0;
381 }
382 
383 /**
384  * pci_enable_device - Initialize device before it's used by a driver.
385  * @dev: PCI device to be initialized
386  *
387  *  Initialize device before it's used by a driver. Ask low-level code
388  *  to enable I/O and memory. Wake up the device if it was suspended.
389  *  Beware, this function can fail.
390  */
391 int
392 pci_enable_device(struct pci_dev *dev)
393 {
394 	int err;
395 
396 	if ((err = pci_enable_device_bars(dev, (1 << PCI_NUM_RESOURCES) - 1)))
397 		return err;
398 	pci_fixup_device(pci_fixup_enable, dev);
399 	dev->is_enabled = 1;
400 	return 0;
401 }
402 
403 /**
404  * pcibios_disable_device - disable arch specific PCI resources for device dev
405  * @dev: the PCI device to disable
406  *
407  * Disables architecture specific PCI resources for the device. This
408  * is the default implementation. Architecture implementations can
409  * override this.
410  */
411 void __attribute__ ((weak)) pcibios_disable_device (struct pci_dev *dev) {}
412 
413 /**
414  * pci_disable_device - Disable PCI device after use
415  * @dev: PCI device to be disabled
416  *
417  * Signal to the system that the PCI device is not in use by the system
418  * anymore.  This only involves disabling PCI bus-mastering, if active.
419  */
420 void
421 pci_disable_device(struct pci_dev *dev)
422 {
423 	u16 pci_command;
424 
425 	pci_read_config_word(dev, PCI_COMMAND, &pci_command);
426 	if (pci_command & PCI_COMMAND_MASTER) {
427 		pci_command &= ~PCI_COMMAND_MASTER;
428 		pci_write_config_word(dev, PCI_COMMAND, pci_command);
429 	}
430 	dev->is_busmaster = 0;
431 
432 	pcibios_disable_device(dev);
433 	dev->is_enabled = 0;
434 }
435 
436 /**
437  * pci_enable_wake - enable device to generate PME# when suspended
438  * @dev: - PCI device to operate on
439  * @state: - Current state of device.
440  * @enable: - Flag to enable or disable generation
441  *
442  * Set the bits in the device's PM Capabilities to generate PME# when
443  * the system is suspended.
444  *
445  * -EIO is returned if device doesn't have PM Capabilities.
446  * -EINVAL is returned if device supports it, but can't generate wake events.
447  * 0 if operation is successful.
448  *
449  */
450 int pci_enable_wake(struct pci_dev *dev, pci_power_t state, int enable)
451 {
452 	int pm;
453 	u16 value;
454 
455 	/* find PCI PM capability in list */
456 	pm = pci_find_capability(dev, PCI_CAP_ID_PM);
457 
458 	/* If device doesn't support PM Capabilities, but request is to disable
459 	 * wake events, it's a nop; otherwise fail */
460 	if (!pm)
461 		return enable ? -EIO : 0;
462 
463 	/* Check device's ability to generate PME# */
464 	pci_read_config_word(dev,pm+PCI_PM_PMC,&value);
465 
466 	value &= PCI_PM_CAP_PME_MASK;
467 	value >>= ffs(PCI_PM_CAP_PME_MASK) - 1;   /* First bit of mask */
468 
469 	/* Check if it can generate PME# from requested state. */
470 	if (!value || !(value & (1 << state)))
471 		return enable ? -EINVAL : 0;
472 
473 	pci_read_config_word(dev, pm + PCI_PM_CTRL, &value);
474 
475 	/* Clear PME_Status by writing 1 to it and enable PME# */
476 	value |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE;
477 
478 	if (!enable)
479 		value &= ~PCI_PM_CTRL_PME_ENABLE;
480 
481 	pci_write_config_word(dev, pm + PCI_PM_CTRL, value);
482 
483 	return 0;
484 }
485 
486 int
487 pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge)
488 {
489 	u8 pin;
490 
491 	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
492 	if (!pin)
493 		return -1;
494 	pin--;
495 	while (dev->bus->self) {
496 		pin = (pin + PCI_SLOT(dev->devfn)) % 4;
497 		dev = dev->bus->self;
498 	}
499 	*bridge = dev;
500 	return pin;
501 }
502 
503 /**
504  *	pci_release_region - Release a PCI bar
505  *	@pdev: PCI device whose resources were previously reserved by pci_request_region
506  *	@bar: BAR to release
507  *
508  *	Releases the PCI I/O and memory resources previously reserved by a
509  *	successful call to pci_request_region.  Call this function only
510  *	after all use of the PCI regions has ceased.
511  */
512 void pci_release_region(struct pci_dev *pdev, int bar)
513 {
514 	if (pci_resource_len(pdev, bar) == 0)
515 		return;
516 	if (pci_resource_flags(pdev, bar) & IORESOURCE_IO)
517 		release_region(pci_resource_start(pdev, bar),
518 				pci_resource_len(pdev, bar));
519 	else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM)
520 		release_mem_region(pci_resource_start(pdev, bar),
521 				pci_resource_len(pdev, bar));
522 }
523 
524 /**
525  *	pci_request_region - Reserved PCI I/O and memory resource
526  *	@pdev: PCI device whose resources are to be reserved
527  *	@bar: BAR to be reserved
528  *	@res_name: Name to be associated with resource.
529  *
530  *	Mark the PCI region associated with PCI device @pdev BR @bar as
531  *	being reserved by owner @res_name.  Do not access any
532  *	address inside the PCI regions unless this call returns
533  *	successfully.
534  *
535  *	Returns 0 on success, or %EBUSY on error.  A warning
536  *	message is also printed on failure.
537  */
538 int pci_request_region(struct pci_dev *pdev, int bar, char *res_name)
539 {
540 	if (pci_resource_len(pdev, bar) == 0)
541 		return 0;
542 
543 	if (pci_resource_flags(pdev, bar) & IORESOURCE_IO) {
544 		if (!request_region(pci_resource_start(pdev, bar),
545 			    pci_resource_len(pdev, bar), res_name))
546 			goto err_out;
547 	}
548 	else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM) {
549 		if (!request_mem_region(pci_resource_start(pdev, bar),
550 				        pci_resource_len(pdev, bar), res_name))
551 			goto err_out;
552 	}
553 
554 	return 0;
555 
556 err_out:
557 	printk (KERN_WARNING "PCI: Unable to reserve %s region #%d:%lx@%lx for device %s\n",
558 		pci_resource_flags(pdev, bar) & IORESOURCE_IO ? "I/O" : "mem",
559 		bar + 1, /* PCI BAR # */
560 		pci_resource_len(pdev, bar), pci_resource_start(pdev, bar),
561 		pci_name(pdev));
562 	return -EBUSY;
563 }
564 
565 
566 /**
567  *	pci_release_regions - Release reserved PCI I/O and memory resources
568  *	@pdev: PCI device whose resources were previously reserved by pci_request_regions
569  *
570  *	Releases all PCI I/O and memory resources previously reserved by a
571  *	successful call to pci_request_regions.  Call this function only
572  *	after all use of the PCI regions has ceased.
573  */
574 
575 void pci_release_regions(struct pci_dev *pdev)
576 {
577 	int i;
578 
579 	for (i = 0; i < 6; i++)
580 		pci_release_region(pdev, i);
581 }
582 
583 /**
584  *	pci_request_regions - Reserved PCI I/O and memory resources
585  *	@pdev: PCI device whose resources are to be reserved
586  *	@res_name: Name to be associated with resource.
587  *
588  *	Mark all PCI regions associated with PCI device @pdev as
589  *	being reserved by owner @res_name.  Do not access any
590  *	address inside the PCI regions unless this call returns
591  *	successfully.
592  *
593  *	Returns 0 on success, or %EBUSY on error.  A warning
594  *	message is also printed on failure.
595  */
596 int pci_request_regions(struct pci_dev *pdev, char *res_name)
597 {
598 	int i;
599 
600 	for (i = 0; i < 6; i++)
601 		if(pci_request_region(pdev, i, res_name))
602 			goto err_out;
603 	return 0;
604 
605 err_out:
606 	while(--i >= 0)
607 		pci_release_region(pdev, i);
608 
609 	return -EBUSY;
610 }
611 
612 /**
613  * pci_set_master - enables bus-mastering for device dev
614  * @dev: the PCI device to enable
615  *
616  * Enables bus-mastering on the device and calls pcibios_set_master()
617  * to do the needed arch specific settings.
618  */
619 void
620 pci_set_master(struct pci_dev *dev)
621 {
622 	u16 cmd;
623 
624 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
625 	if (! (cmd & PCI_COMMAND_MASTER)) {
626 		pr_debug("PCI: Enabling bus mastering for device %s\n", pci_name(dev));
627 		cmd |= PCI_COMMAND_MASTER;
628 		pci_write_config_word(dev, PCI_COMMAND, cmd);
629 	}
630 	dev->is_busmaster = 1;
631 	pcibios_set_master(dev);
632 }
633 
634 #ifndef HAVE_ARCH_PCI_MWI
635 /* This can be overridden by arch code. */
636 u8 pci_cache_line_size = L1_CACHE_BYTES >> 2;
637 
638 /**
639  * pci_generic_prep_mwi - helper function for pci_set_mwi
640  * @dev: the PCI device for which MWI is enabled
641  *
642  * Helper function for generic implementation of pcibios_prep_mwi
643  * function.  Originally copied from drivers/net/acenic.c.
644  * Copyright 1998-2001 by Jes Sorensen, <jes@trained-monkey.org>.
645  *
646  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
647  */
648 static int
649 pci_generic_prep_mwi(struct pci_dev *dev)
650 {
651 	u8 cacheline_size;
652 
653 	if (!pci_cache_line_size)
654 		return -EINVAL;		/* The system doesn't support MWI. */
655 
656 	/* Validate current setting: the PCI_CACHE_LINE_SIZE must be
657 	   equal to or multiple of the right value. */
658 	pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
659 	if (cacheline_size >= pci_cache_line_size &&
660 	    (cacheline_size % pci_cache_line_size) == 0)
661 		return 0;
662 
663 	/* Write the correct value. */
664 	pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, pci_cache_line_size);
665 	/* Read it back. */
666 	pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
667 	if (cacheline_size == pci_cache_line_size)
668 		return 0;
669 
670 	printk(KERN_DEBUG "PCI: cache line size of %d is not supported "
671 	       "by device %s\n", pci_cache_line_size << 2, pci_name(dev));
672 
673 	return -EINVAL;
674 }
675 #endif /* !HAVE_ARCH_PCI_MWI */
676 
677 /**
678  * pci_set_mwi - enables memory-write-invalidate PCI transaction
679  * @dev: the PCI device for which MWI is enabled
680  *
681  * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND,
682  * and then calls @pcibios_set_mwi to do the needed arch specific
683  * operations or a generic mwi-prep function.
684  *
685  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
686  */
687 int
688 pci_set_mwi(struct pci_dev *dev)
689 {
690 	int rc;
691 	u16 cmd;
692 
693 #ifdef HAVE_ARCH_PCI_MWI
694 	rc = pcibios_prep_mwi(dev);
695 #else
696 	rc = pci_generic_prep_mwi(dev);
697 #endif
698 
699 	if (rc)
700 		return rc;
701 
702 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
703 	if (! (cmd & PCI_COMMAND_INVALIDATE)) {
704 		pr_debug("PCI: Enabling Mem-Wr-Inval for device %s\n", pci_name(dev));
705 		cmd |= PCI_COMMAND_INVALIDATE;
706 		pci_write_config_word(dev, PCI_COMMAND, cmd);
707 	}
708 
709 	return 0;
710 }
711 
712 /**
713  * pci_clear_mwi - disables Memory-Write-Invalidate for device dev
714  * @dev: the PCI device to disable
715  *
716  * Disables PCI Memory-Write-Invalidate transaction on the device
717  */
718 void
719 pci_clear_mwi(struct pci_dev *dev)
720 {
721 	u16 cmd;
722 
723 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
724 	if (cmd & PCI_COMMAND_INVALIDATE) {
725 		cmd &= ~PCI_COMMAND_INVALIDATE;
726 		pci_write_config_word(dev, PCI_COMMAND, cmd);
727 	}
728 }
729 
730 #ifndef HAVE_ARCH_PCI_SET_DMA_MASK
731 /*
732  * These can be overridden by arch-specific implementations
733  */
734 int
735 pci_set_dma_mask(struct pci_dev *dev, u64 mask)
736 {
737 	if (!pci_dma_supported(dev, mask))
738 		return -EIO;
739 
740 	dev->dma_mask = mask;
741 
742 	return 0;
743 }
744 
745 int
746 pci_set_consistent_dma_mask(struct pci_dev *dev, u64 mask)
747 {
748 	if (!pci_dma_supported(dev, mask))
749 		return -EIO;
750 
751 	dev->dev.coherent_dma_mask = mask;
752 
753 	return 0;
754 }
755 #endif
756 
757 static int __devinit pci_init(void)
758 {
759 	struct pci_dev *dev = NULL;
760 
761 	while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
762 		pci_fixup_device(pci_fixup_final, dev);
763 	}
764 	return 0;
765 }
766 
767 static int __devinit pci_setup(char *str)
768 {
769 	while (str) {
770 		char *k = strchr(str, ',');
771 		if (k)
772 			*k++ = 0;
773 		if (*str && (str = pcibios_setup(str)) && *str) {
774 			/* PCI layer options should be handled here */
775 			printk(KERN_ERR "PCI: Unknown option `%s'\n", str);
776 		}
777 		str = k;
778 	}
779 	return 1;
780 }
781 
782 device_initcall(pci_init);
783 
784 __setup("pci=", pci_setup);
785 
786 #if defined(CONFIG_ISA) || defined(CONFIG_EISA)
787 /* FIXME: Some boxes have multiple ISA bridges! */
788 struct pci_dev *isa_bridge;
789 EXPORT_SYMBOL(isa_bridge);
790 #endif
791 
792 EXPORT_SYMBOL(pci_enable_device_bars);
793 EXPORT_SYMBOL(pci_enable_device);
794 EXPORT_SYMBOL(pci_disable_device);
795 EXPORT_SYMBOL(pci_max_busnr);
796 EXPORT_SYMBOL(pci_bus_max_busnr);
797 EXPORT_SYMBOL(pci_find_capability);
798 EXPORT_SYMBOL(pci_bus_find_capability);
799 EXPORT_SYMBOL(pci_release_regions);
800 EXPORT_SYMBOL(pci_request_regions);
801 EXPORT_SYMBOL(pci_release_region);
802 EXPORT_SYMBOL(pci_request_region);
803 EXPORT_SYMBOL(pci_set_master);
804 EXPORT_SYMBOL(pci_set_mwi);
805 EXPORT_SYMBOL(pci_clear_mwi);
806 EXPORT_SYMBOL(pci_set_dma_mask);
807 EXPORT_SYMBOL(pci_set_consistent_dma_mask);
808 EXPORT_SYMBOL(pci_assign_resource);
809 EXPORT_SYMBOL(pci_find_parent_resource);
810 
811 EXPORT_SYMBOL(pci_set_power_state);
812 EXPORT_SYMBOL(pci_save_state);
813 EXPORT_SYMBOL(pci_restore_state);
814 EXPORT_SYMBOL(pci_enable_wake);
815 
816 /* Quirk info */
817 
818 EXPORT_SYMBOL(isa_dma_bridge_buggy);
819 EXPORT_SYMBOL(pci_pci_problems);
820