xref: /linux/drivers/pci/pci.c (revision 776cfebb430c7b22c208b1b17add97f354d97cab)
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  * @buffer: - buffer to hold config space context
338  *
339  * @buffer must be large enough to hold the entire PCI 2.2 config space
340  * (>= 64 bytes).
341  */
342 int
343 pci_save_state(struct pci_dev *dev)
344 {
345 	int i;
346 	/* XXX: 100% dword access ok here? */
347 	for (i = 0; i < 16; i++)
348 		pci_read_config_dword(dev, i * 4,&dev->saved_config_space[i]);
349 	return 0;
350 }
351 
352 /**
353  * pci_restore_state - Restore the saved state of a PCI device
354  * @dev: - PCI device that we're dealing with
355  * @buffer: - saved PCI config space
356  *
357  */
358 int
359 pci_restore_state(struct pci_dev *dev)
360 {
361 	int i;
362 
363 	for (i = 0; i < 16; i++)
364 		pci_write_config_dword(dev,i * 4, dev->saved_config_space[i]);
365 	return 0;
366 }
367 
368 /**
369  * pci_enable_device_bars - Initialize some of a device for use
370  * @dev: PCI device to be initialized
371  * @bars: bitmask of BAR's that must be configured
372  *
373  *  Initialize device before it's used by a driver. Ask low-level code
374  *  to enable selected I/O and memory resources. Wake up the device if it
375  *  was suspended. Beware, this function can fail.
376  */
377 
378 int
379 pci_enable_device_bars(struct pci_dev *dev, int bars)
380 {
381 	int err;
382 
383 	pci_set_power_state(dev, PCI_D0);
384 	if ((err = pcibios_enable_device(dev, bars)) < 0)
385 		return err;
386 	return 0;
387 }
388 
389 /**
390  * pci_enable_device - Initialize device before it's used by a driver.
391  * @dev: PCI device to be initialized
392  *
393  *  Initialize device before it's used by a driver. Ask low-level code
394  *  to enable I/O and memory. Wake up the device if it was suspended.
395  *  Beware, this function can fail.
396  */
397 int
398 pci_enable_device(struct pci_dev *dev)
399 {
400 	int err;
401 
402 	if ((err = pci_enable_device_bars(dev, (1 << PCI_NUM_RESOURCES) - 1)))
403 		return err;
404 	pci_fixup_device(pci_fixup_enable, dev);
405 	dev->is_enabled = 1;
406 	return 0;
407 }
408 
409 /**
410  * pcibios_disable_device - disable arch specific PCI resources for device dev
411  * @dev: the PCI device to disable
412  *
413  * Disables architecture specific PCI resources for the device. This
414  * is the default implementation. Architecture implementations can
415  * override this.
416  */
417 void __attribute__ ((weak)) pcibios_disable_device (struct pci_dev *dev) {}
418 
419 /**
420  * pci_disable_device - Disable PCI device after use
421  * @dev: PCI device to be disabled
422  *
423  * Signal to the system that the PCI device is not in use by the system
424  * anymore.  This only involves disabling PCI bus-mastering, if active.
425  */
426 void
427 pci_disable_device(struct pci_dev *dev)
428 {
429 	u16 pci_command;
430 
431 	pci_read_config_word(dev, PCI_COMMAND, &pci_command);
432 	if (pci_command & PCI_COMMAND_MASTER) {
433 		pci_command &= ~PCI_COMMAND_MASTER;
434 		pci_write_config_word(dev, PCI_COMMAND, pci_command);
435 	}
436 	dev->is_busmaster = 0;
437 
438 	pcibios_disable_device(dev);
439 	dev->is_enabled = 0;
440 }
441 
442 /**
443  * pci_enable_wake - enable device to generate PME# when suspended
444  * @dev: - PCI device to operate on
445  * @state: - Current state of device.
446  * @enable: - Flag to enable or disable generation
447  *
448  * Set the bits in the device's PM Capabilities to generate PME# when
449  * the system is suspended.
450  *
451  * -EIO is returned if device doesn't have PM Capabilities.
452  * -EINVAL is returned if device supports it, but can't generate wake events.
453  * 0 if operation is successful.
454  *
455  */
456 int pci_enable_wake(struct pci_dev *dev, pci_power_t state, int enable)
457 {
458 	int pm;
459 	u16 value;
460 
461 	/* find PCI PM capability in list */
462 	pm = pci_find_capability(dev, PCI_CAP_ID_PM);
463 
464 	/* If device doesn't support PM Capabilities, but request is to disable
465 	 * wake events, it's a nop; otherwise fail */
466 	if (!pm)
467 		return enable ? -EIO : 0;
468 
469 	/* Check device's ability to generate PME# */
470 	pci_read_config_word(dev,pm+PCI_PM_PMC,&value);
471 
472 	value &= PCI_PM_CAP_PME_MASK;
473 	value >>= ffs(PCI_PM_CAP_PME_MASK) - 1;   /* First bit of mask */
474 
475 	/* Check if it can generate PME# from requested state. */
476 	if (!value || !(value & (1 << state)))
477 		return enable ? -EINVAL : 0;
478 
479 	pci_read_config_word(dev, pm + PCI_PM_CTRL, &value);
480 
481 	/* Clear PME_Status by writing 1 to it and enable PME# */
482 	value |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE;
483 
484 	if (!enable)
485 		value &= ~PCI_PM_CTRL_PME_ENABLE;
486 
487 	pci_write_config_word(dev, pm + PCI_PM_CTRL, value);
488 
489 	return 0;
490 }
491 
492 int
493 pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge)
494 {
495 	u8 pin;
496 
497 	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
498 	if (!pin)
499 		return -1;
500 	pin--;
501 	while (dev->bus->self) {
502 		pin = (pin + PCI_SLOT(dev->devfn)) % 4;
503 		dev = dev->bus->self;
504 	}
505 	*bridge = dev;
506 	return pin;
507 }
508 
509 /**
510  *	pci_release_region - Release a PCI bar
511  *	@pdev: PCI device whose resources were previously reserved by pci_request_region
512  *	@bar: BAR to release
513  *
514  *	Releases the PCI I/O and memory resources previously reserved by a
515  *	successful call to pci_request_region.  Call this function only
516  *	after all use of the PCI regions has ceased.
517  */
518 void pci_release_region(struct pci_dev *pdev, int bar)
519 {
520 	if (pci_resource_len(pdev, bar) == 0)
521 		return;
522 	if (pci_resource_flags(pdev, bar) & IORESOURCE_IO)
523 		release_region(pci_resource_start(pdev, bar),
524 				pci_resource_len(pdev, bar));
525 	else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM)
526 		release_mem_region(pci_resource_start(pdev, bar),
527 				pci_resource_len(pdev, bar));
528 }
529 
530 /**
531  *	pci_request_region - Reserved PCI I/O and memory resource
532  *	@pdev: PCI device whose resources are to be reserved
533  *	@bar: BAR to be reserved
534  *	@res_name: Name to be associated with resource.
535  *
536  *	Mark the PCI region associated with PCI device @pdev BR @bar as
537  *	being reserved by owner @res_name.  Do not access any
538  *	address inside the PCI regions unless this call returns
539  *	successfully.
540  *
541  *	Returns 0 on success, or %EBUSY on error.  A warning
542  *	message is also printed on failure.
543  */
544 int pci_request_region(struct pci_dev *pdev, int bar, char *res_name)
545 {
546 	if (pci_resource_len(pdev, bar) == 0)
547 		return 0;
548 
549 	if (pci_resource_flags(pdev, bar) & IORESOURCE_IO) {
550 		if (!request_region(pci_resource_start(pdev, bar),
551 			    pci_resource_len(pdev, bar), res_name))
552 			goto err_out;
553 	}
554 	else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM) {
555 		if (!request_mem_region(pci_resource_start(pdev, bar),
556 				        pci_resource_len(pdev, bar), res_name))
557 			goto err_out;
558 	}
559 
560 	return 0;
561 
562 err_out:
563 	printk (KERN_WARNING "PCI: Unable to reserve %s region #%d:%lx@%lx for device %s\n",
564 		pci_resource_flags(pdev, bar) & IORESOURCE_IO ? "I/O" : "mem",
565 		bar + 1, /* PCI BAR # */
566 		pci_resource_len(pdev, bar), pci_resource_start(pdev, bar),
567 		pci_name(pdev));
568 	return -EBUSY;
569 }
570 
571 
572 /**
573  *	pci_release_regions - Release reserved PCI I/O and memory resources
574  *	@pdev: PCI device whose resources were previously reserved by pci_request_regions
575  *
576  *	Releases all PCI I/O and memory resources previously reserved by a
577  *	successful call to pci_request_regions.  Call this function only
578  *	after all use of the PCI regions has ceased.
579  */
580 
581 void pci_release_regions(struct pci_dev *pdev)
582 {
583 	int i;
584 
585 	for (i = 0; i < 6; i++)
586 		pci_release_region(pdev, i);
587 }
588 
589 /**
590  *	pci_request_regions - Reserved PCI I/O and memory resources
591  *	@pdev: PCI device whose resources are to be reserved
592  *	@res_name: Name to be associated with resource.
593  *
594  *	Mark all PCI regions associated with PCI device @pdev as
595  *	being reserved by owner @res_name.  Do not access any
596  *	address inside the PCI regions unless this call returns
597  *	successfully.
598  *
599  *	Returns 0 on success, or %EBUSY on error.  A warning
600  *	message is also printed on failure.
601  */
602 int pci_request_regions(struct pci_dev *pdev, char *res_name)
603 {
604 	int i;
605 
606 	for (i = 0; i < 6; i++)
607 		if(pci_request_region(pdev, i, res_name))
608 			goto err_out;
609 	return 0;
610 
611 err_out:
612 	while(--i >= 0)
613 		pci_release_region(pdev, i);
614 
615 	return -EBUSY;
616 }
617 
618 /**
619  * pci_set_master - enables bus-mastering for device dev
620  * @dev: the PCI device to enable
621  *
622  * Enables bus-mastering on the device and calls pcibios_set_master()
623  * to do the needed arch specific settings.
624  */
625 void
626 pci_set_master(struct pci_dev *dev)
627 {
628 	u16 cmd;
629 
630 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
631 	if (! (cmd & PCI_COMMAND_MASTER)) {
632 		pr_debug("PCI: Enabling bus mastering for device %s\n", pci_name(dev));
633 		cmd |= PCI_COMMAND_MASTER;
634 		pci_write_config_word(dev, PCI_COMMAND, cmd);
635 	}
636 	dev->is_busmaster = 1;
637 	pcibios_set_master(dev);
638 }
639 
640 #ifndef HAVE_ARCH_PCI_MWI
641 /* This can be overridden by arch code. */
642 u8 pci_cache_line_size = L1_CACHE_BYTES >> 2;
643 
644 /**
645  * pci_generic_prep_mwi - helper function for pci_set_mwi
646  * @dev: the PCI device for which MWI is enabled
647  *
648  * Helper function for generic implementation of pcibios_prep_mwi
649  * function.  Originally copied from drivers/net/acenic.c.
650  * Copyright 1998-2001 by Jes Sorensen, <jes@trained-monkey.org>.
651  *
652  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
653  */
654 static int
655 pci_generic_prep_mwi(struct pci_dev *dev)
656 {
657 	u8 cacheline_size;
658 
659 	if (!pci_cache_line_size)
660 		return -EINVAL;		/* The system doesn't support MWI. */
661 
662 	/* Validate current setting: the PCI_CACHE_LINE_SIZE must be
663 	   equal to or multiple of the right value. */
664 	pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
665 	if (cacheline_size >= pci_cache_line_size &&
666 	    (cacheline_size % pci_cache_line_size) == 0)
667 		return 0;
668 
669 	/* Write the correct value. */
670 	pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, pci_cache_line_size);
671 	/* Read it back. */
672 	pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
673 	if (cacheline_size == pci_cache_line_size)
674 		return 0;
675 
676 	printk(KERN_DEBUG "PCI: cache line size of %d is not supported "
677 	       "by device %s\n", pci_cache_line_size << 2, pci_name(dev));
678 
679 	return -EINVAL;
680 }
681 #endif /* !HAVE_ARCH_PCI_MWI */
682 
683 /**
684  * pci_set_mwi - enables memory-write-invalidate PCI transaction
685  * @dev: the PCI device for which MWI is enabled
686  *
687  * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND,
688  * and then calls @pcibios_set_mwi to do the needed arch specific
689  * operations or a generic mwi-prep function.
690  *
691  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
692  */
693 int
694 pci_set_mwi(struct pci_dev *dev)
695 {
696 	int rc;
697 	u16 cmd;
698 
699 #ifdef HAVE_ARCH_PCI_MWI
700 	rc = pcibios_prep_mwi(dev);
701 #else
702 	rc = pci_generic_prep_mwi(dev);
703 #endif
704 
705 	if (rc)
706 		return rc;
707 
708 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
709 	if (! (cmd & PCI_COMMAND_INVALIDATE)) {
710 		pr_debug("PCI: Enabling Mem-Wr-Inval for device %s\n", pci_name(dev));
711 		cmd |= PCI_COMMAND_INVALIDATE;
712 		pci_write_config_word(dev, PCI_COMMAND, cmd);
713 	}
714 
715 	return 0;
716 }
717 
718 /**
719  * pci_clear_mwi - disables Memory-Write-Invalidate for device dev
720  * @dev: the PCI device to disable
721  *
722  * Disables PCI Memory-Write-Invalidate transaction on the device
723  */
724 void
725 pci_clear_mwi(struct pci_dev *dev)
726 {
727 	u16 cmd;
728 
729 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
730 	if (cmd & PCI_COMMAND_INVALIDATE) {
731 		cmd &= ~PCI_COMMAND_INVALIDATE;
732 		pci_write_config_word(dev, PCI_COMMAND, cmd);
733 	}
734 }
735 
736 #ifndef HAVE_ARCH_PCI_SET_DMA_MASK
737 /*
738  * These can be overridden by arch-specific implementations
739  */
740 int
741 pci_set_dma_mask(struct pci_dev *dev, u64 mask)
742 {
743 	if (!pci_dma_supported(dev, mask))
744 		return -EIO;
745 
746 	dev->dma_mask = mask;
747 
748 	return 0;
749 }
750 
751 int
752 pci_set_consistent_dma_mask(struct pci_dev *dev, u64 mask)
753 {
754 	if (!pci_dma_supported(dev, mask))
755 		return -EIO;
756 
757 	dev->dev.coherent_dma_mask = mask;
758 
759 	return 0;
760 }
761 #endif
762 
763 static int __devinit pci_init(void)
764 {
765 	struct pci_dev *dev = NULL;
766 
767 	while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
768 		pci_fixup_device(pci_fixup_final, dev);
769 	}
770 	return 0;
771 }
772 
773 static int __devinit pci_setup(char *str)
774 {
775 	while (str) {
776 		char *k = strchr(str, ',');
777 		if (k)
778 			*k++ = 0;
779 		if (*str && (str = pcibios_setup(str)) && *str) {
780 			/* PCI layer options should be handled here */
781 			printk(KERN_ERR "PCI: Unknown option `%s'\n", str);
782 		}
783 		str = k;
784 	}
785 	return 1;
786 }
787 
788 device_initcall(pci_init);
789 
790 __setup("pci=", pci_setup);
791 
792 #if defined(CONFIG_ISA) || defined(CONFIG_EISA)
793 /* FIXME: Some boxes have multiple ISA bridges! */
794 struct pci_dev *isa_bridge;
795 EXPORT_SYMBOL(isa_bridge);
796 #endif
797 
798 EXPORT_SYMBOL(pci_enable_device_bars);
799 EXPORT_SYMBOL(pci_enable_device);
800 EXPORT_SYMBOL(pci_disable_device);
801 EXPORT_SYMBOL(pci_max_busnr);
802 EXPORT_SYMBOL(pci_bus_max_busnr);
803 EXPORT_SYMBOL(pci_find_capability);
804 EXPORT_SYMBOL(pci_bus_find_capability);
805 EXPORT_SYMBOL(pci_release_regions);
806 EXPORT_SYMBOL(pci_request_regions);
807 EXPORT_SYMBOL(pci_release_region);
808 EXPORT_SYMBOL(pci_request_region);
809 EXPORT_SYMBOL(pci_set_master);
810 EXPORT_SYMBOL(pci_set_mwi);
811 EXPORT_SYMBOL(pci_clear_mwi);
812 EXPORT_SYMBOL(pci_set_dma_mask);
813 EXPORT_SYMBOL(pci_set_consistent_dma_mask);
814 EXPORT_SYMBOL(pci_assign_resource);
815 EXPORT_SYMBOL(pci_find_parent_resource);
816 
817 EXPORT_SYMBOL(pci_set_power_state);
818 EXPORT_SYMBOL(pci_save_state);
819 EXPORT_SYMBOL(pci_restore_state);
820 EXPORT_SYMBOL(pci_enable_wake);
821 
822 /* Quirk info */
823 
824 EXPORT_SYMBOL(isa_dma_bridge_buggy);
825 EXPORT_SYMBOL(pci_pci_problems);
826