xref: /linux/drivers/pci/pci.c (revision 858259cf7d1c443c836a2022b78cb281f0a9b95e)
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->number;
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 
45 /**
46  * pci_max_busnr - returns maximum PCI bus number
47  *
48  * Returns the highest PCI bus number present in the system global list of
49  * PCI buses.
50  */
51 unsigned char __devinit
52 pci_max_busnr(void)
53 {
54 	struct pci_bus *bus = NULL;
55 	unsigned char max, n;
56 
57 	max = 0;
58 	while ((bus = pci_find_next_bus(bus)) != NULL) {
59 		n = pci_bus_max_busnr(bus);
60 		if(n > max)
61 			max = n;
62 	}
63 	return max;
64 }
65 
66 static int __pci_bus_find_cap(struct pci_bus *bus, unsigned int devfn, u8 hdr_type, int cap)
67 {
68 	u16 status;
69 	u8 pos, id;
70 	int ttl = 48;
71 
72 	pci_bus_read_config_word(bus, devfn, PCI_STATUS, &status);
73 	if (!(status & PCI_STATUS_CAP_LIST))
74 		return 0;
75 
76 	switch (hdr_type) {
77 	case PCI_HEADER_TYPE_NORMAL:
78 	case PCI_HEADER_TYPE_BRIDGE:
79 		pci_bus_read_config_byte(bus, devfn, PCI_CAPABILITY_LIST, &pos);
80 		break;
81 	case PCI_HEADER_TYPE_CARDBUS:
82 		pci_bus_read_config_byte(bus, devfn, PCI_CB_CAPABILITY_LIST, &pos);
83 		break;
84 	default:
85 		return 0;
86 	}
87 	while (ttl-- && pos >= 0x40) {
88 		pos &= ~3;
89 		pci_bus_read_config_byte(bus, devfn, pos + PCI_CAP_LIST_ID, &id);
90 		if (id == 0xff)
91 			break;
92 		if (id == cap)
93 			return pos;
94 		pci_bus_read_config_byte(bus, devfn, pos + PCI_CAP_LIST_NEXT, &pos);
95 	}
96 	return 0;
97 }
98 
99 /**
100  * pci_find_capability - query for devices' capabilities
101  * @dev: PCI device to query
102  * @cap: capability code
103  *
104  * Tell if a device supports a given PCI capability.
105  * Returns the address of the requested capability structure within the
106  * device's PCI configuration space or 0 in case the device does not
107  * support it.  Possible values for @cap:
108  *
109  *  %PCI_CAP_ID_PM           Power Management
110  *  %PCI_CAP_ID_AGP          Accelerated Graphics Port
111  *  %PCI_CAP_ID_VPD          Vital Product Data
112  *  %PCI_CAP_ID_SLOTID       Slot Identification
113  *  %PCI_CAP_ID_MSI          Message Signalled Interrupts
114  *  %PCI_CAP_ID_CHSWP        CompactPCI HotSwap
115  *  %PCI_CAP_ID_PCIX         PCI-X
116  *  %PCI_CAP_ID_EXP          PCI Express
117  */
118 int pci_find_capability(struct pci_dev *dev, int cap)
119 {
120 	return __pci_bus_find_cap(dev->bus, dev->devfn, dev->hdr_type, cap);
121 }
122 
123 /**
124  * pci_bus_find_capability - query for devices' capabilities
125  * @bus:   the PCI bus to query
126  * @devfn: PCI device to query
127  * @cap:   capability code
128  *
129  * Like pci_find_capability() but works for pci devices that do not have a
130  * pci_dev structure set up yet.
131  *
132  * Returns the address of the requested capability structure within the
133  * device's PCI configuration space or 0 in case the device does not
134  * support it.
135  */
136 int pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap)
137 {
138 	u8 hdr_type;
139 
140 	pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &hdr_type);
141 
142 	return __pci_bus_find_cap(bus, devfn, hdr_type & 0x7f, cap);
143 }
144 
145 /**
146  * pci_find_ext_capability - Find an extended capability
147  * @dev: PCI device to query
148  * @cap: capability code
149  *
150  * Returns the address of the requested extended capability structure
151  * within the device's PCI configuration space or 0 if the device does
152  * not support it.  Possible values for @cap:
153  *
154  *  %PCI_EXT_CAP_ID_ERR		Advanced Error Reporting
155  *  %PCI_EXT_CAP_ID_VC		Virtual Channel
156  *  %PCI_EXT_CAP_ID_DSN		Device Serial Number
157  *  %PCI_EXT_CAP_ID_PWR		Power Budgeting
158  */
159 int pci_find_ext_capability(struct pci_dev *dev, int cap)
160 {
161 	u32 header;
162 	int ttl = 480; /* 3840 bytes, minimum 8 bytes per capability */
163 	int pos = 0x100;
164 
165 	if (dev->cfg_size <= 256)
166 		return 0;
167 
168 	if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
169 		return 0;
170 
171 	/*
172 	 * If we have no capabilities, this is indicated by cap ID,
173 	 * cap version and next pointer all being 0.
174 	 */
175 	if (header == 0)
176 		return 0;
177 
178 	while (ttl-- > 0) {
179 		if (PCI_EXT_CAP_ID(header) == cap)
180 			return pos;
181 
182 		pos = PCI_EXT_CAP_NEXT(header);
183 		if (pos < 0x100)
184 			break;
185 
186 		if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
187 			break;
188 	}
189 
190 	return 0;
191 }
192 
193 /**
194  * pci_find_parent_resource - return resource region of parent bus of given region
195  * @dev: PCI device structure contains resources to be searched
196  * @res: child resource record for which parent is sought
197  *
198  *  For given resource region of given device, return the resource
199  *  region of parent bus the given region is contained in or where
200  *  it should be allocated from.
201  */
202 struct resource *
203 pci_find_parent_resource(const struct pci_dev *dev, struct resource *res)
204 {
205 	const struct pci_bus *bus = dev->bus;
206 	int i;
207 	struct resource *best = NULL;
208 
209 	for(i = 0; i < PCI_BUS_NUM_RESOURCES; i++) {
210 		struct resource *r = bus->resource[i];
211 		if (!r)
212 			continue;
213 		if (res->start && !(res->start >= r->start && res->end <= r->end))
214 			continue;	/* Not contained */
215 		if ((res->flags ^ r->flags) & (IORESOURCE_IO | IORESOURCE_MEM))
216 			continue;	/* Wrong type */
217 		if (!((res->flags ^ r->flags) & IORESOURCE_PREFETCH))
218 			return r;	/* Exact match */
219 		if ((res->flags & IORESOURCE_PREFETCH) && !(r->flags & IORESOURCE_PREFETCH))
220 			best = r;	/* Approximating prefetchable by non-prefetchable */
221 	}
222 	return best;
223 }
224 
225 /**
226  * pci_restore_bars - restore a devices BAR values (e.g. after wake-up)
227  * @dev: PCI device to have its BARs restored
228  *
229  * Restore the BAR values for a given device, so as to make it
230  * accessible by its driver.
231  */
232 void
233 pci_restore_bars(struct pci_dev *dev)
234 {
235 	int i, numres;
236 
237 	switch (dev->hdr_type) {
238 	case PCI_HEADER_TYPE_NORMAL:
239 		numres = 6;
240 		break;
241 	case PCI_HEADER_TYPE_BRIDGE:
242 		numres = 2;
243 		break;
244 	case PCI_HEADER_TYPE_CARDBUS:
245 		numres = 1;
246 		break;
247 	default:
248 		/* Should never get here, but just in case... */
249 		return;
250 	}
251 
252 	for (i = 0; i < numres; i ++)
253 		pci_update_resource(dev, &dev->resource[i], i);
254 }
255 
256 int (*platform_pci_set_power_state)(struct pci_dev *dev, pci_power_t t);
257 
258 /**
259  * pci_set_power_state - Set the power state of a PCI device
260  * @dev: PCI device to be suspended
261  * @state: PCI power state (D0, D1, D2, D3hot, D3cold) we're entering
262  *
263  * Transition a device to a new power state, using the Power Management
264  * Capabilities in the device's config space.
265  *
266  * RETURN VALUE:
267  * -EINVAL if trying to enter a lower state than we're already in.
268  * 0 if we're already in the requested state.
269  * -EIO if device does not support PCI PM.
270  * 0 if we can successfully change the power state.
271  */
272 int
273 pci_set_power_state(struct pci_dev *dev, pci_power_t state)
274 {
275 	int pm, need_restore = 0;
276 	u16 pmcsr, pmc;
277 
278 	/* bound the state we're entering */
279 	if (state > PCI_D3hot)
280 		state = PCI_D3hot;
281 
282 	/* Validate current state:
283 	 * Can enter D0 from any state, but if we can only go deeper
284 	 * to sleep if we're already in a low power state
285 	 */
286 	if (state != PCI_D0 && dev->current_state > state)
287 		return -EINVAL;
288 	else if (dev->current_state == state)
289 		return 0;        /* we're already there */
290 
291 	/* find PCI PM capability in list */
292 	pm = pci_find_capability(dev, PCI_CAP_ID_PM);
293 
294 	/* abort if the device doesn't support PM capabilities */
295 	if (!pm)
296 		return -EIO;
297 
298 	pci_read_config_word(dev,pm + PCI_PM_PMC,&pmc);
299 	if ((pmc & PCI_PM_CAP_VER_MASK) > 3) {
300 		printk(KERN_DEBUG
301 		       "PCI: %s has unsupported PM cap regs version (%u)\n",
302 		       pci_name(dev), pmc & PCI_PM_CAP_VER_MASK);
303 		return -EIO;
304 	}
305 
306 	/* check if this device supports the desired state */
307 	if (state == PCI_D1 && !(pmc & PCI_PM_CAP_D1))
308 		return -EIO;
309 	else if (state == PCI_D2 && !(pmc & PCI_PM_CAP_D2))
310 		return -EIO;
311 
312 	pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr);
313 
314 	/* If we're (effectively) in D3, force entire word to 0.
315 	 * This doesn't affect PME_Status, disables PME_En, and
316 	 * sets PowerState to 0.
317 	 */
318 	switch (dev->current_state) {
319 	case PCI_D0:
320 	case PCI_D1:
321 	case PCI_D2:
322 		pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
323 		pmcsr |= state;
324 		break;
325 	case PCI_UNKNOWN: /* Boot-up */
326 		if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot
327 		 && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))
328 			need_restore = 1;
329 		/* Fall-through: force to D0 */
330 	default:
331 		pmcsr = 0;
332 		break;
333 	}
334 
335 	/* enter specified state */
336 	pci_write_config_word(dev, pm + PCI_PM_CTRL, pmcsr);
337 
338 	/* Mandatory power management transition delays */
339 	/* see PCI PM 1.1 5.6.1 table 18 */
340 	if (state == PCI_D3hot || dev->current_state == PCI_D3hot)
341 		msleep(10);
342 	else if (state == PCI_D2 || dev->current_state == PCI_D2)
343 		udelay(200);
344 
345 	/*
346 	 * Give firmware a chance to be called, such as ACPI _PRx, _PSx
347 	 * Firmware method after natice method ?
348 	 */
349 	if (platform_pci_set_power_state)
350 		platform_pci_set_power_state(dev, state);
351 
352 	dev->current_state = state;
353 
354 	/* According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT
355 	 * INTERFACE SPECIFICATION, REV. 1.2", a device transitioning
356 	 * from D3hot to D0 _may_ perform an internal reset, thereby
357 	 * going to "D0 Uninitialized" rather than "D0 Initialized".
358 	 * For example, at least some versions of the 3c905B and the
359 	 * 3c556B exhibit this behaviour.
360 	 *
361 	 * At least some laptop BIOSen (e.g. the Thinkpad T21) leave
362 	 * devices in a D3hot state at boot.  Consequently, we need to
363 	 * restore at least the BARs so that the device will be
364 	 * accessible to its driver.
365 	 */
366 	if (need_restore)
367 		pci_restore_bars(dev);
368 
369 	return 0;
370 }
371 
372 int (*platform_pci_choose_state)(struct pci_dev *dev, pm_message_t state);
373 
374 /**
375  * pci_choose_state - Choose the power state of a PCI device
376  * @dev: PCI device to be suspended
377  * @state: target sleep state for the whole system. This is the value
378  *	that is passed to suspend() function.
379  *
380  * Returns PCI power state suitable for given device and given system
381  * message.
382  */
383 
384 pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state)
385 {
386 	int ret;
387 
388 	if (!pci_find_capability(dev, PCI_CAP_ID_PM))
389 		return PCI_D0;
390 
391 	if (platform_pci_choose_state) {
392 		ret = platform_pci_choose_state(dev, state);
393 		if (ret >= 0)
394 			state.event = ret;
395 	}
396 
397 	switch (state.event) {
398 	case PM_EVENT_ON:
399 		return PCI_D0;
400 	case PM_EVENT_FREEZE:
401 	case PM_EVENT_SUSPEND:
402 		return PCI_D3hot;
403 	default:
404 		printk("They asked me for state %d\n", state.event);
405 		BUG();
406 	}
407 	return PCI_D0;
408 }
409 
410 EXPORT_SYMBOL(pci_choose_state);
411 
412 /**
413  * pci_save_state - save the PCI configuration space of a device before suspending
414  * @dev: - PCI device that we're dealing with
415  */
416 int
417 pci_save_state(struct pci_dev *dev)
418 {
419 	int i;
420 	/* XXX: 100% dword access ok here? */
421 	for (i = 0; i < 16; i++)
422 		pci_read_config_dword(dev, i * 4,&dev->saved_config_space[i]);
423 	return 0;
424 }
425 
426 /**
427  * pci_restore_state - Restore the saved state of a PCI device
428  * @dev: - PCI device that we're dealing with
429  */
430 int
431 pci_restore_state(struct pci_dev *dev)
432 {
433 	int i;
434 
435 	for (i = 0; i < 16; i++)
436 		pci_write_config_dword(dev,i * 4, dev->saved_config_space[i]);
437 	return 0;
438 }
439 
440 /**
441  * pci_enable_device_bars - Initialize some of a device for use
442  * @dev: PCI device to be initialized
443  * @bars: bitmask of BAR's that must be configured
444  *
445  *  Initialize device before it's used by a driver. Ask low-level code
446  *  to enable selected I/O and memory resources. Wake up the device if it
447  *  was suspended. Beware, this function can fail.
448  */
449 
450 int
451 pci_enable_device_bars(struct pci_dev *dev, int bars)
452 {
453 	int err;
454 
455 	err = pci_set_power_state(dev, PCI_D0);
456 	if (err < 0 && err != -EIO)
457 		return err;
458 	err = pcibios_enable_device(dev, bars);
459 	if (err < 0)
460 		return err;
461 	return 0;
462 }
463 
464 /**
465  * pci_enable_device - Initialize device before it's used by a driver.
466  * @dev: PCI device to be initialized
467  *
468  *  Initialize device before it's used by a driver. Ask low-level code
469  *  to enable I/O and memory. Wake up the device if it was suspended.
470  *  Beware, this function can fail.
471  */
472 int
473 pci_enable_device(struct pci_dev *dev)
474 {
475 	int err;
476 
477 	if ((err = pci_enable_device_bars(dev, (1 << PCI_NUM_RESOURCES) - 1)))
478 		return err;
479 	pci_fixup_device(pci_fixup_enable, dev);
480 	dev->is_enabled = 1;
481 	return 0;
482 }
483 
484 /**
485  * pcibios_disable_device - disable arch specific PCI resources for device dev
486  * @dev: the PCI device to disable
487  *
488  * Disables architecture specific PCI resources for the device. This
489  * is the default implementation. Architecture implementations can
490  * override this.
491  */
492 void __attribute__ ((weak)) pcibios_disable_device (struct pci_dev *dev) {}
493 
494 /**
495  * pci_disable_device - Disable PCI device after use
496  * @dev: PCI device to be disabled
497  *
498  * Signal to the system that the PCI device is not in use by the system
499  * anymore.  This only involves disabling PCI bus-mastering, if active.
500  */
501 void
502 pci_disable_device(struct pci_dev *dev)
503 {
504 	u16 pci_command;
505 
506 	pci_read_config_word(dev, PCI_COMMAND, &pci_command);
507 	if (pci_command & PCI_COMMAND_MASTER) {
508 		pci_command &= ~PCI_COMMAND_MASTER;
509 		pci_write_config_word(dev, PCI_COMMAND, pci_command);
510 	}
511 	dev->is_busmaster = 0;
512 
513 	pcibios_disable_device(dev);
514 	dev->is_enabled = 0;
515 }
516 
517 /**
518  * pci_enable_wake - enable device to generate PME# when suspended
519  * @dev: - PCI device to operate on
520  * @state: - Current state of device.
521  * @enable: - Flag to enable or disable generation
522  *
523  * Set the bits in the device's PM Capabilities to generate PME# when
524  * the system is suspended.
525  *
526  * -EIO is returned if device doesn't have PM Capabilities.
527  * -EINVAL is returned if device supports it, but can't generate wake events.
528  * 0 if operation is successful.
529  *
530  */
531 int pci_enable_wake(struct pci_dev *dev, pci_power_t state, int enable)
532 {
533 	int pm;
534 	u16 value;
535 
536 	/* find PCI PM capability in list */
537 	pm = pci_find_capability(dev, PCI_CAP_ID_PM);
538 
539 	/* If device doesn't support PM Capabilities, but request is to disable
540 	 * wake events, it's a nop; otherwise fail */
541 	if (!pm)
542 		return enable ? -EIO : 0;
543 
544 	/* Check device's ability to generate PME# */
545 	pci_read_config_word(dev,pm+PCI_PM_PMC,&value);
546 
547 	value &= PCI_PM_CAP_PME_MASK;
548 	value >>= ffs(PCI_PM_CAP_PME_MASK) - 1;   /* First bit of mask */
549 
550 	/* Check if it can generate PME# from requested state. */
551 	if (!value || !(value & (1 << state)))
552 		return enable ? -EINVAL : 0;
553 
554 	pci_read_config_word(dev, pm + PCI_PM_CTRL, &value);
555 
556 	/* Clear PME_Status by writing 1 to it and enable PME# */
557 	value |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE;
558 
559 	if (!enable)
560 		value &= ~PCI_PM_CTRL_PME_ENABLE;
561 
562 	pci_write_config_word(dev, pm + PCI_PM_CTRL, value);
563 
564 	return 0;
565 }
566 
567 int
568 pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge)
569 {
570 	u8 pin;
571 
572 	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
573 	if (!pin)
574 		return -1;
575 	pin--;
576 	while (dev->bus->self) {
577 		pin = (pin + PCI_SLOT(dev->devfn)) % 4;
578 		dev = dev->bus->self;
579 	}
580 	*bridge = dev;
581 	return pin;
582 }
583 
584 /**
585  *	pci_release_region - Release a PCI bar
586  *	@pdev: PCI device whose resources were previously reserved by pci_request_region
587  *	@bar: BAR to release
588  *
589  *	Releases the PCI I/O and memory resources previously reserved by a
590  *	successful call to pci_request_region.  Call this function only
591  *	after all use of the PCI regions has ceased.
592  */
593 void pci_release_region(struct pci_dev *pdev, int bar)
594 {
595 	if (pci_resource_len(pdev, bar) == 0)
596 		return;
597 	if (pci_resource_flags(pdev, bar) & IORESOURCE_IO)
598 		release_region(pci_resource_start(pdev, bar),
599 				pci_resource_len(pdev, bar));
600 	else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM)
601 		release_mem_region(pci_resource_start(pdev, bar),
602 				pci_resource_len(pdev, bar));
603 }
604 
605 /**
606  *	pci_request_region - Reserved PCI I/O and memory resource
607  *	@pdev: PCI device whose resources are to be reserved
608  *	@bar: BAR to be reserved
609  *	@res_name: Name to be associated with resource.
610  *
611  *	Mark the PCI region associated with PCI device @pdev BR @bar as
612  *	being reserved by owner @res_name.  Do not access any
613  *	address inside the PCI regions unless this call returns
614  *	successfully.
615  *
616  *	Returns 0 on success, or %EBUSY on error.  A warning
617  *	message is also printed on failure.
618  */
619 int pci_request_region(struct pci_dev *pdev, int bar, char *res_name)
620 {
621 	if (pci_resource_len(pdev, bar) == 0)
622 		return 0;
623 
624 	if (pci_resource_flags(pdev, bar) & IORESOURCE_IO) {
625 		if (!request_region(pci_resource_start(pdev, bar),
626 			    pci_resource_len(pdev, bar), res_name))
627 			goto err_out;
628 	}
629 	else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM) {
630 		if (!request_mem_region(pci_resource_start(pdev, bar),
631 				        pci_resource_len(pdev, bar), res_name))
632 			goto err_out;
633 	}
634 
635 	return 0;
636 
637 err_out:
638 	printk (KERN_WARNING "PCI: Unable to reserve %s region #%d:%lx@%lx for device %s\n",
639 		pci_resource_flags(pdev, bar) & IORESOURCE_IO ? "I/O" : "mem",
640 		bar + 1, /* PCI BAR # */
641 		pci_resource_len(pdev, bar), pci_resource_start(pdev, bar),
642 		pci_name(pdev));
643 	return -EBUSY;
644 }
645 
646 
647 /**
648  *	pci_release_regions - Release reserved PCI I/O and memory resources
649  *	@pdev: PCI device whose resources were previously reserved by pci_request_regions
650  *
651  *	Releases all PCI I/O and memory resources previously reserved by a
652  *	successful call to pci_request_regions.  Call this function only
653  *	after all use of the PCI regions has ceased.
654  */
655 
656 void pci_release_regions(struct pci_dev *pdev)
657 {
658 	int i;
659 
660 	for (i = 0; i < 6; i++)
661 		pci_release_region(pdev, i);
662 }
663 
664 /**
665  *	pci_request_regions - Reserved PCI I/O and memory resources
666  *	@pdev: PCI device whose resources are to be reserved
667  *	@res_name: Name to be associated with resource.
668  *
669  *	Mark all PCI regions associated with PCI device @pdev as
670  *	being reserved by owner @res_name.  Do not access any
671  *	address inside the PCI regions unless this call returns
672  *	successfully.
673  *
674  *	Returns 0 on success, or %EBUSY on error.  A warning
675  *	message is also printed on failure.
676  */
677 int pci_request_regions(struct pci_dev *pdev, char *res_name)
678 {
679 	int i;
680 
681 	for (i = 0; i < 6; i++)
682 		if(pci_request_region(pdev, i, res_name))
683 			goto err_out;
684 	return 0;
685 
686 err_out:
687 	while(--i >= 0)
688 		pci_release_region(pdev, i);
689 
690 	return -EBUSY;
691 }
692 
693 /**
694  * pci_set_master - enables bus-mastering for device dev
695  * @dev: the PCI device to enable
696  *
697  * Enables bus-mastering on the device and calls pcibios_set_master()
698  * to do the needed arch specific settings.
699  */
700 void
701 pci_set_master(struct pci_dev *dev)
702 {
703 	u16 cmd;
704 
705 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
706 	if (! (cmd & PCI_COMMAND_MASTER)) {
707 		pr_debug("PCI: Enabling bus mastering for device %s\n", pci_name(dev));
708 		cmd |= PCI_COMMAND_MASTER;
709 		pci_write_config_word(dev, PCI_COMMAND, cmd);
710 	}
711 	dev->is_busmaster = 1;
712 	pcibios_set_master(dev);
713 }
714 
715 #ifndef HAVE_ARCH_PCI_MWI
716 /* This can be overridden by arch code. */
717 u8 pci_cache_line_size = L1_CACHE_BYTES >> 2;
718 
719 /**
720  * pci_generic_prep_mwi - helper function for pci_set_mwi
721  * @dev: the PCI device for which MWI is enabled
722  *
723  * Helper function for generic implementation of pcibios_prep_mwi
724  * function.  Originally copied from drivers/net/acenic.c.
725  * Copyright 1998-2001 by Jes Sorensen, <jes@trained-monkey.org>.
726  *
727  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
728  */
729 static int
730 pci_generic_prep_mwi(struct pci_dev *dev)
731 {
732 	u8 cacheline_size;
733 
734 	if (!pci_cache_line_size)
735 		return -EINVAL;		/* The system doesn't support MWI. */
736 
737 	/* Validate current setting: the PCI_CACHE_LINE_SIZE must be
738 	   equal to or multiple of the right value. */
739 	pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
740 	if (cacheline_size >= pci_cache_line_size &&
741 	    (cacheline_size % pci_cache_line_size) == 0)
742 		return 0;
743 
744 	/* Write the correct value. */
745 	pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, pci_cache_line_size);
746 	/* Read it back. */
747 	pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
748 	if (cacheline_size == pci_cache_line_size)
749 		return 0;
750 
751 	printk(KERN_DEBUG "PCI: cache line size of %d is not supported "
752 	       "by device %s\n", pci_cache_line_size << 2, pci_name(dev));
753 
754 	return -EINVAL;
755 }
756 #endif /* !HAVE_ARCH_PCI_MWI */
757 
758 /**
759  * pci_set_mwi - enables memory-write-invalidate PCI transaction
760  * @dev: the PCI device for which MWI is enabled
761  *
762  * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND,
763  * and then calls @pcibios_set_mwi to do the needed arch specific
764  * operations or a generic mwi-prep function.
765  *
766  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
767  */
768 int
769 pci_set_mwi(struct pci_dev *dev)
770 {
771 	int rc;
772 	u16 cmd;
773 
774 #ifdef HAVE_ARCH_PCI_MWI
775 	rc = pcibios_prep_mwi(dev);
776 #else
777 	rc = pci_generic_prep_mwi(dev);
778 #endif
779 
780 	if (rc)
781 		return rc;
782 
783 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
784 	if (! (cmd & PCI_COMMAND_INVALIDATE)) {
785 		pr_debug("PCI: Enabling Mem-Wr-Inval for device %s\n", pci_name(dev));
786 		cmd |= PCI_COMMAND_INVALIDATE;
787 		pci_write_config_word(dev, PCI_COMMAND, cmd);
788 	}
789 
790 	return 0;
791 }
792 
793 /**
794  * pci_clear_mwi - disables Memory-Write-Invalidate for device dev
795  * @dev: the PCI device to disable
796  *
797  * Disables PCI Memory-Write-Invalidate transaction on the device
798  */
799 void
800 pci_clear_mwi(struct pci_dev *dev)
801 {
802 	u16 cmd;
803 
804 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
805 	if (cmd & PCI_COMMAND_INVALIDATE) {
806 		cmd &= ~PCI_COMMAND_INVALIDATE;
807 		pci_write_config_word(dev, PCI_COMMAND, cmd);
808 	}
809 }
810 
811 /**
812  * pci_intx - enables/disables PCI INTx for device dev
813  * @pdev: the PCI device to operate on
814  * @enable: boolean: whether to enable or disable PCI INTx
815  *
816  * Enables/disables PCI INTx for device dev
817  */
818 void
819 pci_intx(struct pci_dev *pdev, int enable)
820 {
821 	u16 pci_command, new;
822 
823 	pci_read_config_word(pdev, PCI_COMMAND, &pci_command);
824 
825 	if (enable) {
826 		new = pci_command & ~PCI_COMMAND_INTX_DISABLE;
827 	} else {
828 		new = pci_command | PCI_COMMAND_INTX_DISABLE;
829 	}
830 
831 	if (new != pci_command) {
832 		pci_write_config_word(pdev, PCI_COMMAND, new);
833 	}
834 }
835 
836 #ifndef HAVE_ARCH_PCI_SET_DMA_MASK
837 /*
838  * These can be overridden by arch-specific implementations
839  */
840 int
841 pci_set_dma_mask(struct pci_dev *dev, u64 mask)
842 {
843 	if (!pci_dma_supported(dev, mask))
844 		return -EIO;
845 
846 	dev->dma_mask = mask;
847 
848 	return 0;
849 }
850 
851 int
852 pci_set_consistent_dma_mask(struct pci_dev *dev, u64 mask)
853 {
854 	if (!pci_dma_supported(dev, mask))
855 		return -EIO;
856 
857 	dev->dev.coherent_dma_mask = mask;
858 
859 	return 0;
860 }
861 #endif
862 
863 static int __devinit pci_init(void)
864 {
865 	struct pci_dev *dev = NULL;
866 
867 	while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
868 		pci_fixup_device(pci_fixup_final, dev);
869 	}
870 	return 0;
871 }
872 
873 static int __devinit pci_setup(char *str)
874 {
875 	while (str) {
876 		char *k = strchr(str, ',');
877 		if (k)
878 			*k++ = 0;
879 		if (*str && (str = pcibios_setup(str)) && *str) {
880 			/* PCI layer options should be handled here */
881 			printk(KERN_ERR "PCI: Unknown option `%s'\n", str);
882 		}
883 		str = k;
884 	}
885 	return 1;
886 }
887 
888 device_initcall(pci_init);
889 
890 __setup("pci=", pci_setup);
891 
892 #if defined(CONFIG_ISA) || defined(CONFIG_EISA)
893 /* FIXME: Some boxes have multiple ISA bridges! */
894 struct pci_dev *isa_bridge;
895 EXPORT_SYMBOL(isa_bridge);
896 #endif
897 
898 EXPORT_SYMBOL_GPL(pci_restore_bars);
899 EXPORT_SYMBOL(pci_enable_device_bars);
900 EXPORT_SYMBOL(pci_enable_device);
901 EXPORT_SYMBOL(pci_disable_device);
902 EXPORT_SYMBOL(pci_max_busnr);
903 EXPORT_SYMBOL(pci_bus_max_busnr);
904 EXPORT_SYMBOL(pci_find_capability);
905 EXPORT_SYMBOL(pci_bus_find_capability);
906 EXPORT_SYMBOL(pci_release_regions);
907 EXPORT_SYMBOL(pci_request_regions);
908 EXPORT_SYMBOL(pci_release_region);
909 EXPORT_SYMBOL(pci_request_region);
910 EXPORT_SYMBOL(pci_set_master);
911 EXPORT_SYMBOL(pci_set_mwi);
912 EXPORT_SYMBOL(pci_clear_mwi);
913 EXPORT_SYMBOL_GPL(pci_intx);
914 EXPORT_SYMBOL(pci_set_dma_mask);
915 EXPORT_SYMBOL(pci_set_consistent_dma_mask);
916 EXPORT_SYMBOL(pci_assign_resource);
917 EXPORT_SYMBOL(pci_find_parent_resource);
918 
919 EXPORT_SYMBOL(pci_set_power_state);
920 EXPORT_SYMBOL(pci_save_state);
921 EXPORT_SYMBOL(pci_restore_state);
922 EXPORT_SYMBOL(pci_enable_wake);
923 
924 /* Quirk info */
925 
926 EXPORT_SYMBOL(isa_dma_bridge_buggy);
927 EXPORT_SYMBOL(pci_pci_problems);
928