xref: /linux/drivers/pci/pci.c (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862)
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 <linux/string.h>
19 #include <asm/dma.h>	/* isa_dma_bridge_buggy */
20 #include "pci.h"
21 
22 
23 /**
24  * pci_bus_max_busnr - returns maximum PCI bus number of given bus' children
25  * @bus: pointer to PCI bus structure to search
26  *
27  * Given a PCI bus, returns the highest PCI bus number present in the set
28  * including the given PCI bus and its list of child PCI buses.
29  */
30 unsigned char __devinit
31 pci_bus_max_busnr(struct pci_bus* bus)
32 {
33 	struct list_head *tmp;
34 	unsigned char max, n;
35 
36 	max = bus->subordinate;
37 	list_for_each(tmp, &bus->children) {
38 		n = pci_bus_max_busnr(pci_bus_b(tmp));
39 		if(n > max)
40 			max = n;
41 	}
42 	return max;
43 }
44 EXPORT_SYMBOL_GPL(pci_bus_max_busnr);
45 
46 #if 0
47 /**
48  * pci_max_busnr - returns maximum PCI bus number
49  *
50  * Returns the highest PCI bus number present in the system global list of
51  * PCI buses.
52  */
53 unsigned char __devinit
54 pci_max_busnr(void)
55 {
56 	struct pci_bus *bus = NULL;
57 	unsigned char max, n;
58 
59 	max = 0;
60 	while ((bus = pci_find_next_bus(bus)) != NULL) {
61 		n = pci_bus_max_busnr(bus);
62 		if(n > max)
63 			max = n;
64 	}
65 	return max;
66 }
67 
68 #endif  /*  0  */
69 
70 static int __pci_find_next_cap(struct pci_bus *bus, unsigned int devfn, u8 pos, int cap)
71 {
72 	u8 id;
73 	int ttl = 48;
74 
75 	while (ttl--) {
76 		pci_bus_read_config_byte(bus, devfn, pos, &pos);
77 		if (pos < 0x40)
78 			break;
79 		pos &= ~3;
80 		pci_bus_read_config_byte(bus, devfn, pos + PCI_CAP_LIST_ID,
81 					 &id);
82 		if (id == 0xff)
83 			break;
84 		if (id == cap)
85 			return pos;
86 		pos += PCI_CAP_LIST_NEXT;
87 	}
88 	return 0;
89 }
90 
91 int pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap)
92 {
93 	return __pci_find_next_cap(dev->bus, dev->devfn,
94 				   pos + PCI_CAP_LIST_NEXT, cap);
95 }
96 EXPORT_SYMBOL_GPL(pci_find_next_capability);
97 
98 static int __pci_bus_find_cap(struct pci_bus *bus, unsigned int devfn, u8 hdr_type, int cap)
99 {
100 	u16 status;
101 	u8 pos;
102 
103 	pci_bus_read_config_word(bus, devfn, PCI_STATUS, &status);
104 	if (!(status & PCI_STATUS_CAP_LIST))
105 		return 0;
106 
107 	switch (hdr_type) {
108 	case PCI_HEADER_TYPE_NORMAL:
109 	case PCI_HEADER_TYPE_BRIDGE:
110 		pos = PCI_CAPABILITY_LIST;
111 		break;
112 	case PCI_HEADER_TYPE_CARDBUS:
113 		pos = PCI_CB_CAPABILITY_LIST;
114 		break;
115 	default:
116 		return 0;
117 	}
118 	return __pci_find_next_cap(bus, devfn, pos, cap);
119 }
120 
121 /**
122  * pci_find_capability - query for devices' capabilities
123  * @dev: PCI device to query
124  * @cap: capability code
125  *
126  * Tell if a device supports a given PCI capability.
127  * Returns the address of the requested capability structure within the
128  * device's PCI configuration space or 0 in case the device does not
129  * support it.  Possible values for @cap:
130  *
131  *  %PCI_CAP_ID_PM           Power Management
132  *  %PCI_CAP_ID_AGP          Accelerated Graphics Port
133  *  %PCI_CAP_ID_VPD          Vital Product Data
134  *  %PCI_CAP_ID_SLOTID       Slot Identification
135  *  %PCI_CAP_ID_MSI          Message Signalled Interrupts
136  *  %PCI_CAP_ID_CHSWP        CompactPCI HotSwap
137  *  %PCI_CAP_ID_PCIX         PCI-X
138  *  %PCI_CAP_ID_EXP          PCI Express
139  */
140 int pci_find_capability(struct pci_dev *dev, int cap)
141 {
142 	return __pci_bus_find_cap(dev->bus, dev->devfn, dev->hdr_type, cap);
143 }
144 
145 /**
146  * pci_bus_find_capability - query for devices' capabilities
147  * @bus:   the PCI bus to query
148  * @devfn: PCI device to query
149  * @cap:   capability code
150  *
151  * Like pci_find_capability() but works for pci devices that do not have a
152  * pci_dev structure set up yet.
153  *
154  * Returns the address of the requested capability structure within the
155  * device's PCI configuration space or 0 in case the device does not
156  * support it.
157  */
158 int pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap)
159 {
160 	u8 hdr_type;
161 
162 	pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &hdr_type);
163 
164 	return __pci_bus_find_cap(bus, devfn, hdr_type & 0x7f, cap);
165 }
166 
167 /**
168  * pci_find_ext_capability - Find an extended capability
169  * @dev: PCI device to query
170  * @cap: capability code
171  *
172  * Returns the address of the requested extended capability structure
173  * within the device's PCI configuration space or 0 if the device does
174  * not support it.  Possible values for @cap:
175  *
176  *  %PCI_EXT_CAP_ID_ERR		Advanced Error Reporting
177  *  %PCI_EXT_CAP_ID_VC		Virtual Channel
178  *  %PCI_EXT_CAP_ID_DSN		Device Serial Number
179  *  %PCI_EXT_CAP_ID_PWR		Power Budgeting
180  */
181 int pci_find_ext_capability(struct pci_dev *dev, int cap)
182 {
183 	u32 header;
184 	int ttl = 480; /* 3840 bytes, minimum 8 bytes per capability */
185 	int pos = 0x100;
186 
187 	if (dev->cfg_size <= 256)
188 		return 0;
189 
190 	if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
191 		return 0;
192 
193 	/*
194 	 * If we have no capabilities, this is indicated by cap ID,
195 	 * cap version and next pointer all being 0.
196 	 */
197 	if (header == 0)
198 		return 0;
199 
200 	while (ttl-- > 0) {
201 		if (PCI_EXT_CAP_ID(header) == cap)
202 			return pos;
203 
204 		pos = PCI_EXT_CAP_NEXT(header);
205 		if (pos < 0x100)
206 			break;
207 
208 		if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
209 			break;
210 	}
211 
212 	return 0;
213 }
214 EXPORT_SYMBOL_GPL(pci_find_ext_capability);
215 
216 /**
217  * pci_find_parent_resource - return resource region of parent bus of given region
218  * @dev: PCI device structure contains resources to be searched
219  * @res: child resource record for which parent is sought
220  *
221  *  For given resource region of given device, return the resource
222  *  region of parent bus the given region is contained in or where
223  *  it should be allocated from.
224  */
225 struct resource *
226 pci_find_parent_resource(const struct pci_dev *dev, struct resource *res)
227 {
228 	const struct pci_bus *bus = dev->bus;
229 	int i;
230 	struct resource *best = NULL;
231 
232 	for(i = 0; i < PCI_BUS_NUM_RESOURCES; i++) {
233 		struct resource *r = bus->resource[i];
234 		if (!r)
235 			continue;
236 		if (res->start && !(res->start >= r->start && res->end <= r->end))
237 			continue;	/* Not contained */
238 		if ((res->flags ^ r->flags) & (IORESOURCE_IO | IORESOURCE_MEM))
239 			continue;	/* Wrong type */
240 		if (!((res->flags ^ r->flags) & IORESOURCE_PREFETCH))
241 			return r;	/* Exact match */
242 		if ((res->flags & IORESOURCE_PREFETCH) && !(r->flags & IORESOURCE_PREFETCH))
243 			best = r;	/* Approximating prefetchable by non-prefetchable */
244 	}
245 	return best;
246 }
247 
248 /**
249  * pci_restore_bars - restore a devices BAR values (e.g. after wake-up)
250  * @dev: PCI device to have its BARs restored
251  *
252  * Restore the BAR values for a given device, so as to make it
253  * accessible by its driver.
254  */
255 void
256 pci_restore_bars(struct pci_dev *dev)
257 {
258 	int i, numres;
259 
260 	switch (dev->hdr_type) {
261 	case PCI_HEADER_TYPE_NORMAL:
262 		numres = 6;
263 		break;
264 	case PCI_HEADER_TYPE_BRIDGE:
265 		numres = 2;
266 		break;
267 	case PCI_HEADER_TYPE_CARDBUS:
268 		numres = 1;
269 		break;
270 	default:
271 		/* Should never get here, but just in case... */
272 		return;
273 	}
274 
275 	for (i = 0; i < numres; i ++)
276 		pci_update_resource(dev, &dev->resource[i], i);
277 }
278 
279 int (*platform_pci_set_power_state)(struct pci_dev *dev, pci_power_t t);
280 
281 /**
282  * pci_set_power_state - Set the power state of a PCI device
283  * @dev: PCI device to be suspended
284  * @state: PCI power state (D0, D1, D2, D3hot, D3cold) we're entering
285  *
286  * Transition a device to a new power state, using the Power Management
287  * Capabilities in the device's config space.
288  *
289  * RETURN VALUE:
290  * -EINVAL if trying to enter a lower state than we're already in.
291  * 0 if we're already in the requested state.
292  * -EIO if device does not support PCI PM.
293  * 0 if we can successfully change the power state.
294  */
295 int
296 pci_set_power_state(struct pci_dev *dev, pci_power_t state)
297 {
298 	int pm, need_restore = 0;
299 	u16 pmcsr, pmc;
300 
301 	/* bound the state we're entering */
302 	if (state > PCI_D3hot)
303 		state = PCI_D3hot;
304 
305 	/* Validate current state:
306 	 * Can enter D0 from any state, but if we can only go deeper
307 	 * to sleep if we're already in a low power state
308 	 */
309 	if (state != PCI_D0 && dev->current_state > state) {
310 		printk(KERN_ERR "%s(): %s: state=%d, current state=%d\n",
311 			__FUNCTION__, pci_name(dev), state, dev->current_state);
312 		return -EINVAL;
313 	} else if (dev->current_state == state)
314 		return 0;        /* we're already there */
315 
316 	/* find PCI PM capability in list */
317 	pm = pci_find_capability(dev, PCI_CAP_ID_PM);
318 
319 	/* abort if the device doesn't support PM capabilities */
320 	if (!pm)
321 		return -EIO;
322 
323 	pci_read_config_word(dev,pm + PCI_PM_PMC,&pmc);
324 	if ((pmc & PCI_PM_CAP_VER_MASK) > 3) {
325 		printk(KERN_DEBUG
326 		       "PCI: %s has unsupported PM cap regs version (%u)\n",
327 		       pci_name(dev), pmc & PCI_PM_CAP_VER_MASK);
328 		return -EIO;
329 	}
330 
331 	/* check if this device supports the desired state */
332 	if (state == PCI_D1 && !(pmc & PCI_PM_CAP_D1))
333 		return -EIO;
334 	else if (state == PCI_D2 && !(pmc & PCI_PM_CAP_D2))
335 		return -EIO;
336 
337 	pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr);
338 
339 	/* If we're (effectively) in D3, force entire word to 0.
340 	 * This doesn't affect PME_Status, disables PME_En, and
341 	 * sets PowerState to 0.
342 	 */
343 	switch (dev->current_state) {
344 	case PCI_D0:
345 	case PCI_D1:
346 	case PCI_D2:
347 		pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
348 		pmcsr |= state;
349 		break;
350 	case PCI_UNKNOWN: /* Boot-up */
351 		if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot
352 		 && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))
353 			need_restore = 1;
354 		/* Fall-through: force to D0 */
355 	default:
356 		pmcsr = 0;
357 		break;
358 	}
359 
360 	/* enter specified state */
361 	pci_write_config_word(dev, pm + PCI_PM_CTRL, pmcsr);
362 
363 	/* Mandatory power management transition delays */
364 	/* see PCI PM 1.1 5.6.1 table 18 */
365 	if (state == PCI_D3hot || dev->current_state == PCI_D3hot)
366 		msleep(10);
367 	else if (state == PCI_D2 || dev->current_state == PCI_D2)
368 		udelay(200);
369 
370 	/*
371 	 * Give firmware a chance to be called, such as ACPI _PRx, _PSx
372 	 * Firmware method after native method ?
373 	 */
374 	if (platform_pci_set_power_state)
375 		platform_pci_set_power_state(dev, state);
376 
377 	dev->current_state = state;
378 
379 	/* According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT
380 	 * INTERFACE SPECIFICATION, REV. 1.2", a device transitioning
381 	 * from D3hot to D0 _may_ perform an internal reset, thereby
382 	 * going to "D0 Uninitialized" rather than "D0 Initialized".
383 	 * For example, at least some versions of the 3c905B and the
384 	 * 3c556B exhibit this behaviour.
385 	 *
386 	 * At least some laptop BIOSen (e.g. the Thinkpad T21) leave
387 	 * devices in a D3hot state at boot.  Consequently, we need to
388 	 * restore at least the BARs so that the device will be
389 	 * accessible to its driver.
390 	 */
391 	if (need_restore)
392 		pci_restore_bars(dev);
393 
394 	return 0;
395 }
396 
397 int (*platform_pci_choose_state)(struct pci_dev *dev, pm_message_t state);
398 
399 /**
400  * pci_choose_state - Choose the power state of a PCI device
401  * @dev: PCI device to be suspended
402  * @state: target sleep state for the whole system. This is the value
403  *	that is passed to suspend() function.
404  *
405  * Returns PCI power state suitable for given device and given system
406  * message.
407  */
408 
409 pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state)
410 {
411 	int ret;
412 
413 	if (!pci_find_capability(dev, PCI_CAP_ID_PM))
414 		return PCI_D0;
415 
416 	if (platform_pci_choose_state) {
417 		ret = platform_pci_choose_state(dev, state);
418 		if (ret >= 0)
419 			state.event = ret;
420 	}
421 
422 	switch (state.event) {
423 	case PM_EVENT_ON:
424 		return PCI_D0;
425 	case PM_EVENT_FREEZE:
426 	case PM_EVENT_SUSPEND:
427 		return PCI_D3hot;
428 	default:
429 		printk("They asked me for state %d\n", state.event);
430 		BUG();
431 	}
432 	return PCI_D0;
433 }
434 
435 EXPORT_SYMBOL(pci_choose_state);
436 
437 /**
438  * pci_save_state - save the PCI configuration space of a device before suspending
439  * @dev: - PCI device that we're dealing with
440  */
441 int
442 pci_save_state(struct pci_dev *dev)
443 {
444 	int i;
445 	/* XXX: 100% dword access ok here? */
446 	for (i = 0; i < 16; i++)
447 		pci_read_config_dword(dev, i * 4,&dev->saved_config_space[i]);
448 	if ((i = pci_save_msi_state(dev)) != 0)
449 		return i;
450 	if ((i = pci_save_msix_state(dev)) != 0)
451 		return i;
452 	return 0;
453 }
454 
455 /**
456  * pci_restore_state - Restore the saved state of a PCI device
457  * @dev: - PCI device that we're dealing with
458  */
459 int
460 pci_restore_state(struct pci_dev *dev)
461 {
462 	int i;
463 	int val;
464 
465 	/*
466 	 * The Base Address register should be programmed before the command
467 	 * register(s)
468 	 */
469 	for (i = 15; i >= 0; i--) {
470 		pci_read_config_dword(dev, i * 4, &val);
471 		if (val != dev->saved_config_space[i]) {
472 			printk(KERN_DEBUG "PM: Writing back config space on "
473 				"device %s at offset %x (was %x, writing %x)\n",
474 				pci_name(dev), i,
475 				val, (int)dev->saved_config_space[i]);
476 			pci_write_config_dword(dev,i * 4,
477 				dev->saved_config_space[i]);
478 		}
479 	}
480 	pci_restore_msi_state(dev);
481 	pci_restore_msix_state(dev);
482 	return 0;
483 }
484 
485 /**
486  * pci_enable_device_bars - Initialize some of a device for use
487  * @dev: PCI device to be initialized
488  * @bars: bitmask of BAR's that must be configured
489  *
490  *  Initialize device before it's used by a driver. Ask low-level code
491  *  to enable selected I/O and memory resources. Wake up the device if it
492  *  was suspended. Beware, this function can fail.
493  */
494 
495 int
496 pci_enable_device_bars(struct pci_dev *dev, int bars)
497 {
498 	int err;
499 
500 	err = pci_set_power_state(dev, PCI_D0);
501 	if (err < 0 && err != -EIO)
502 		return err;
503 	err = pcibios_enable_device(dev, bars);
504 	if (err < 0)
505 		return err;
506 	return 0;
507 }
508 
509 /**
510  * pci_enable_device - Initialize device before it's used by a driver.
511  * @dev: PCI device to be initialized
512  *
513  *  Initialize device before it's used by a driver. Ask low-level code
514  *  to enable I/O and memory. Wake up the device if it was suspended.
515  *  Beware, this function can fail.
516  */
517 int
518 pci_enable_device(struct pci_dev *dev)
519 {
520 	int err;
521 
522 	if (dev->is_enabled)
523 		return 0;
524 
525 	err = pci_enable_device_bars(dev, (1 << PCI_NUM_RESOURCES) - 1);
526 	if (err)
527 		return err;
528 	pci_fixup_device(pci_fixup_enable, dev);
529 	dev->is_enabled = 1;
530 	return 0;
531 }
532 
533 /**
534  * pcibios_disable_device - disable arch specific PCI resources for device dev
535  * @dev: the PCI device to disable
536  *
537  * Disables architecture specific PCI resources for the device. This
538  * is the default implementation. Architecture implementations can
539  * override this.
540  */
541 void __attribute__ ((weak)) pcibios_disable_device (struct pci_dev *dev) {}
542 
543 /**
544  * pci_disable_device - Disable PCI device after use
545  * @dev: PCI device to be disabled
546  *
547  * Signal to the system that the PCI device is not in use by the system
548  * anymore.  This only involves disabling PCI bus-mastering, if active.
549  */
550 void
551 pci_disable_device(struct pci_dev *dev)
552 {
553 	u16 pci_command;
554 
555 	if (dev->msi_enabled)
556 		disable_msi_mode(dev, pci_find_capability(dev, PCI_CAP_ID_MSI),
557 			PCI_CAP_ID_MSI);
558 	if (dev->msix_enabled)
559 		disable_msi_mode(dev, pci_find_capability(dev, PCI_CAP_ID_MSI),
560 			PCI_CAP_ID_MSIX);
561 
562 	pci_read_config_word(dev, PCI_COMMAND, &pci_command);
563 	if (pci_command & PCI_COMMAND_MASTER) {
564 		pci_command &= ~PCI_COMMAND_MASTER;
565 		pci_write_config_word(dev, PCI_COMMAND, pci_command);
566 	}
567 	dev->is_busmaster = 0;
568 
569 	pcibios_disable_device(dev);
570 	dev->is_enabled = 0;
571 }
572 
573 /**
574  * pci_enable_wake - enable device to generate PME# when suspended
575  * @dev: - PCI device to operate on
576  * @state: - Current state of device.
577  * @enable: - Flag to enable or disable generation
578  *
579  * Set the bits in the device's PM Capabilities to generate PME# when
580  * the system is suspended.
581  *
582  * -EIO is returned if device doesn't have PM Capabilities.
583  * -EINVAL is returned if device supports it, but can't generate wake events.
584  * 0 if operation is successful.
585  *
586  */
587 int pci_enable_wake(struct pci_dev *dev, pci_power_t state, int enable)
588 {
589 	int pm;
590 	u16 value;
591 
592 	/* find PCI PM capability in list */
593 	pm = pci_find_capability(dev, PCI_CAP_ID_PM);
594 
595 	/* If device doesn't support PM Capabilities, but request is to disable
596 	 * wake events, it's a nop; otherwise fail */
597 	if (!pm)
598 		return enable ? -EIO : 0;
599 
600 	/* Check device's ability to generate PME# */
601 	pci_read_config_word(dev,pm+PCI_PM_PMC,&value);
602 
603 	value &= PCI_PM_CAP_PME_MASK;
604 	value >>= ffs(PCI_PM_CAP_PME_MASK) - 1;   /* First bit of mask */
605 
606 	/* Check if it can generate PME# from requested state. */
607 	if (!value || !(value & (1 << state)))
608 		return enable ? -EINVAL : 0;
609 
610 	pci_read_config_word(dev, pm + PCI_PM_CTRL, &value);
611 
612 	/* Clear PME_Status by writing 1 to it and enable PME# */
613 	value |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE;
614 
615 	if (!enable)
616 		value &= ~PCI_PM_CTRL_PME_ENABLE;
617 
618 	pci_write_config_word(dev, pm + PCI_PM_CTRL, value);
619 
620 	return 0;
621 }
622 
623 int
624 pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge)
625 {
626 	u8 pin;
627 
628 	pin = dev->pin;
629 	if (!pin)
630 		return -1;
631 	pin--;
632 	while (dev->bus->self) {
633 		pin = (pin + PCI_SLOT(dev->devfn)) % 4;
634 		dev = dev->bus->self;
635 	}
636 	*bridge = dev;
637 	return pin;
638 }
639 
640 /**
641  *	pci_release_region - Release a PCI bar
642  *	@pdev: PCI device whose resources were previously reserved by pci_request_region
643  *	@bar: BAR to release
644  *
645  *	Releases the PCI I/O and memory resources previously reserved by a
646  *	successful call to pci_request_region.  Call this function only
647  *	after all use of the PCI regions has ceased.
648  */
649 void pci_release_region(struct pci_dev *pdev, int bar)
650 {
651 	if (pci_resource_len(pdev, bar) == 0)
652 		return;
653 	if (pci_resource_flags(pdev, bar) & IORESOURCE_IO)
654 		release_region(pci_resource_start(pdev, bar),
655 				pci_resource_len(pdev, bar));
656 	else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM)
657 		release_mem_region(pci_resource_start(pdev, bar),
658 				pci_resource_len(pdev, bar));
659 }
660 
661 /**
662  *	pci_request_region - Reserved PCI I/O and memory resource
663  *	@pdev: PCI device whose resources are to be reserved
664  *	@bar: BAR to be reserved
665  *	@res_name: Name to be associated with resource.
666  *
667  *	Mark the PCI region associated with PCI device @pdev BR @bar as
668  *	being reserved by owner @res_name.  Do not access any
669  *	address inside the PCI regions unless this call returns
670  *	successfully.
671  *
672  *	Returns 0 on success, or %EBUSY on error.  A warning
673  *	message is also printed on failure.
674  */
675 int pci_request_region(struct pci_dev *pdev, int bar, const char *res_name)
676 {
677 	if (pci_resource_len(pdev, bar) == 0)
678 		return 0;
679 
680 	if (pci_resource_flags(pdev, bar) & IORESOURCE_IO) {
681 		if (!request_region(pci_resource_start(pdev, bar),
682 			    pci_resource_len(pdev, bar), res_name))
683 			goto err_out;
684 	}
685 	else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM) {
686 		if (!request_mem_region(pci_resource_start(pdev, bar),
687 				        pci_resource_len(pdev, bar), res_name))
688 			goto err_out;
689 	}
690 
691 	return 0;
692 
693 err_out:
694 	printk (KERN_WARNING "PCI: Unable to reserve %s region #%d:%llx@%llx "
695 		"for device %s\n",
696 		pci_resource_flags(pdev, bar) & IORESOURCE_IO ? "I/O" : "mem",
697 		bar + 1, /* PCI BAR # */
698 		(unsigned long long)pci_resource_len(pdev, bar),
699 		(unsigned long long)pci_resource_start(pdev, bar),
700 		pci_name(pdev));
701 	return -EBUSY;
702 }
703 
704 
705 /**
706  *	pci_release_regions - Release reserved PCI I/O and memory resources
707  *	@pdev: PCI device whose resources were previously reserved by pci_request_regions
708  *
709  *	Releases all PCI I/O and memory resources previously reserved by a
710  *	successful call to pci_request_regions.  Call this function only
711  *	after all use of the PCI regions has ceased.
712  */
713 
714 void pci_release_regions(struct pci_dev *pdev)
715 {
716 	int i;
717 
718 	for (i = 0; i < 6; i++)
719 		pci_release_region(pdev, i);
720 }
721 
722 /**
723  *	pci_request_regions - Reserved PCI I/O and memory resources
724  *	@pdev: PCI device whose resources are to be reserved
725  *	@res_name: Name to be associated with resource.
726  *
727  *	Mark all PCI regions associated with PCI device @pdev as
728  *	being reserved by owner @res_name.  Do not access any
729  *	address inside the PCI regions unless this call returns
730  *	successfully.
731  *
732  *	Returns 0 on success, or %EBUSY on error.  A warning
733  *	message is also printed on failure.
734  */
735 int pci_request_regions(struct pci_dev *pdev, const char *res_name)
736 {
737 	int i;
738 
739 	for (i = 0; i < 6; i++)
740 		if(pci_request_region(pdev, i, res_name))
741 			goto err_out;
742 	return 0;
743 
744 err_out:
745 	while(--i >= 0)
746 		pci_release_region(pdev, i);
747 
748 	return -EBUSY;
749 }
750 
751 /**
752  * pci_set_master - enables bus-mastering for device dev
753  * @dev: the PCI device to enable
754  *
755  * Enables bus-mastering on the device and calls pcibios_set_master()
756  * to do the needed arch specific settings.
757  */
758 void
759 pci_set_master(struct pci_dev *dev)
760 {
761 	u16 cmd;
762 
763 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
764 	if (! (cmd & PCI_COMMAND_MASTER)) {
765 		pr_debug("PCI: Enabling bus mastering for device %s\n", pci_name(dev));
766 		cmd |= PCI_COMMAND_MASTER;
767 		pci_write_config_word(dev, PCI_COMMAND, cmd);
768 	}
769 	dev->is_busmaster = 1;
770 	pcibios_set_master(dev);
771 }
772 
773 #ifndef HAVE_ARCH_PCI_MWI
774 /* This can be overridden by arch code. */
775 u8 pci_cache_line_size = L1_CACHE_BYTES >> 2;
776 
777 /**
778  * pci_generic_prep_mwi - helper function for pci_set_mwi
779  * @dev: the PCI device for which MWI is enabled
780  *
781  * Helper function for generic implementation of pcibios_prep_mwi
782  * function.  Originally copied from drivers/net/acenic.c.
783  * Copyright 1998-2001 by Jes Sorensen, <jes@trained-monkey.org>.
784  *
785  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
786  */
787 static int
788 pci_generic_prep_mwi(struct pci_dev *dev)
789 {
790 	u8 cacheline_size;
791 
792 	if (!pci_cache_line_size)
793 		return -EINVAL;		/* The system doesn't support MWI. */
794 
795 	/* Validate current setting: the PCI_CACHE_LINE_SIZE must be
796 	   equal to or multiple of the right value. */
797 	pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
798 	if (cacheline_size >= pci_cache_line_size &&
799 	    (cacheline_size % pci_cache_line_size) == 0)
800 		return 0;
801 
802 	/* Write the correct value. */
803 	pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, pci_cache_line_size);
804 	/* Read it back. */
805 	pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
806 	if (cacheline_size == pci_cache_line_size)
807 		return 0;
808 
809 	printk(KERN_DEBUG "PCI: cache line size of %d is not supported "
810 	       "by device %s\n", pci_cache_line_size << 2, pci_name(dev));
811 
812 	return -EINVAL;
813 }
814 #endif /* !HAVE_ARCH_PCI_MWI */
815 
816 /**
817  * pci_set_mwi - enables memory-write-invalidate PCI transaction
818  * @dev: the PCI device for which MWI is enabled
819  *
820  * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND,
821  * and then calls @pcibios_set_mwi to do the needed arch specific
822  * operations or a generic mwi-prep function.
823  *
824  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
825  */
826 int
827 pci_set_mwi(struct pci_dev *dev)
828 {
829 	int rc;
830 	u16 cmd;
831 
832 #ifdef HAVE_ARCH_PCI_MWI
833 	rc = pcibios_prep_mwi(dev);
834 #else
835 	rc = pci_generic_prep_mwi(dev);
836 #endif
837 
838 	if (rc)
839 		return rc;
840 
841 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
842 	if (! (cmd & PCI_COMMAND_INVALIDATE)) {
843 		pr_debug("PCI: Enabling Mem-Wr-Inval for device %s\n", pci_name(dev));
844 		cmd |= PCI_COMMAND_INVALIDATE;
845 		pci_write_config_word(dev, PCI_COMMAND, cmd);
846 	}
847 
848 	return 0;
849 }
850 
851 /**
852  * pci_clear_mwi - disables Memory-Write-Invalidate for device dev
853  * @dev: the PCI device to disable
854  *
855  * Disables PCI Memory-Write-Invalidate transaction on the device
856  */
857 void
858 pci_clear_mwi(struct pci_dev *dev)
859 {
860 	u16 cmd;
861 
862 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
863 	if (cmd & PCI_COMMAND_INVALIDATE) {
864 		cmd &= ~PCI_COMMAND_INVALIDATE;
865 		pci_write_config_word(dev, PCI_COMMAND, cmd);
866 	}
867 }
868 
869 /**
870  * pci_intx - enables/disables PCI INTx for device dev
871  * @pdev: the PCI device to operate on
872  * @enable: boolean: whether to enable or disable PCI INTx
873  *
874  * Enables/disables PCI INTx for device dev
875  */
876 void
877 pci_intx(struct pci_dev *pdev, int enable)
878 {
879 	u16 pci_command, new;
880 
881 	pci_read_config_word(pdev, PCI_COMMAND, &pci_command);
882 
883 	if (enable) {
884 		new = pci_command & ~PCI_COMMAND_INTX_DISABLE;
885 	} else {
886 		new = pci_command | PCI_COMMAND_INTX_DISABLE;
887 	}
888 
889 	if (new != pci_command) {
890 		pci_write_config_word(pdev, PCI_COMMAND, new);
891 	}
892 }
893 
894 #ifndef HAVE_ARCH_PCI_SET_DMA_MASK
895 /*
896  * These can be overridden by arch-specific implementations
897  */
898 int
899 pci_set_dma_mask(struct pci_dev *dev, u64 mask)
900 {
901 	if (!pci_dma_supported(dev, mask))
902 		return -EIO;
903 
904 	dev->dma_mask = mask;
905 
906 	return 0;
907 }
908 
909 int
910 pci_set_consistent_dma_mask(struct pci_dev *dev, u64 mask)
911 {
912 	if (!pci_dma_supported(dev, mask))
913 		return -EIO;
914 
915 	dev->dev.coherent_dma_mask = mask;
916 
917 	return 0;
918 }
919 #endif
920 
921 static int __devinit pci_init(void)
922 {
923 	struct pci_dev *dev = NULL;
924 
925 	while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
926 		pci_fixup_device(pci_fixup_final, dev);
927 	}
928 	return 0;
929 }
930 
931 static int __devinit pci_setup(char *str)
932 {
933 	while (str) {
934 		char *k = strchr(str, ',');
935 		if (k)
936 			*k++ = 0;
937 		if (*str && (str = pcibios_setup(str)) && *str) {
938 			if (!strcmp(str, "nomsi")) {
939 				pci_no_msi();
940 			} else {
941 				printk(KERN_ERR "PCI: Unknown option `%s'\n",
942 						str);
943 			}
944 		}
945 		str = k;
946 	}
947 	return 1;
948 }
949 
950 device_initcall(pci_init);
951 
952 __setup("pci=", pci_setup);
953 
954 #if defined(CONFIG_ISA) || defined(CONFIG_EISA)
955 /* FIXME: Some boxes have multiple ISA bridges! */
956 struct pci_dev *isa_bridge;
957 EXPORT_SYMBOL(isa_bridge);
958 #endif
959 
960 EXPORT_SYMBOL_GPL(pci_restore_bars);
961 EXPORT_SYMBOL(pci_enable_device_bars);
962 EXPORT_SYMBOL(pci_enable_device);
963 EXPORT_SYMBOL(pci_disable_device);
964 EXPORT_SYMBOL(pci_find_capability);
965 EXPORT_SYMBOL(pci_bus_find_capability);
966 EXPORT_SYMBOL(pci_release_regions);
967 EXPORT_SYMBOL(pci_request_regions);
968 EXPORT_SYMBOL(pci_release_region);
969 EXPORT_SYMBOL(pci_request_region);
970 EXPORT_SYMBOL(pci_set_master);
971 EXPORT_SYMBOL(pci_set_mwi);
972 EXPORT_SYMBOL(pci_clear_mwi);
973 EXPORT_SYMBOL_GPL(pci_intx);
974 EXPORT_SYMBOL(pci_set_dma_mask);
975 EXPORT_SYMBOL(pci_set_consistent_dma_mask);
976 EXPORT_SYMBOL(pci_assign_resource);
977 EXPORT_SYMBOL(pci_find_parent_resource);
978 
979 EXPORT_SYMBOL(pci_set_power_state);
980 EXPORT_SYMBOL(pci_save_state);
981 EXPORT_SYMBOL(pci_restore_state);
982 EXPORT_SYMBOL(pci_enable_wake);
983 
984 /* Quirk info */
985 
986 EXPORT_SYMBOL(isa_dma_bridge_buggy);
987 EXPORT_SYMBOL(pci_pci_problems);
988