xref: /linux/drivers/pci/pci.c (revision 7b12b9137930eb821b68e1bfa11e9de692208620)
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 #if 0
168 /**
169  * pci_find_ext_capability - Find an extended capability
170  * @dev: PCI device to query
171  * @cap: capability code
172  *
173  * Returns the address of the requested extended capability structure
174  * within the device's PCI configuration space or 0 if the device does
175  * not support it.  Possible values for @cap:
176  *
177  *  %PCI_EXT_CAP_ID_ERR		Advanced Error Reporting
178  *  %PCI_EXT_CAP_ID_VC		Virtual Channel
179  *  %PCI_EXT_CAP_ID_DSN		Device Serial Number
180  *  %PCI_EXT_CAP_ID_PWR		Power Budgeting
181  */
182 int pci_find_ext_capability(struct pci_dev *dev, int cap)
183 {
184 	u32 header;
185 	int ttl = 480; /* 3840 bytes, minimum 8 bytes per capability */
186 	int pos = 0x100;
187 
188 	if (dev->cfg_size <= 256)
189 		return 0;
190 
191 	if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
192 		return 0;
193 
194 	/*
195 	 * If we have no capabilities, this is indicated by cap ID,
196 	 * cap version and next pointer all being 0.
197 	 */
198 	if (header == 0)
199 		return 0;
200 
201 	while (ttl-- > 0) {
202 		if (PCI_EXT_CAP_ID(header) == cap)
203 			return pos;
204 
205 		pos = PCI_EXT_CAP_NEXT(header);
206 		if (pos < 0x100)
207 			break;
208 
209 		if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
210 			break;
211 	}
212 
213 	return 0;
214 }
215 #endif  /*  0  */
216 
217 /**
218  * pci_find_parent_resource - return resource region of parent bus of given region
219  * @dev: PCI device structure contains resources to be searched
220  * @res: child resource record for which parent is sought
221  *
222  *  For given resource region of given device, return the resource
223  *  region of parent bus the given region is contained in or where
224  *  it should be allocated from.
225  */
226 struct resource *
227 pci_find_parent_resource(const struct pci_dev *dev, struct resource *res)
228 {
229 	const struct pci_bus *bus = dev->bus;
230 	int i;
231 	struct resource *best = NULL;
232 
233 	for(i = 0; i < PCI_BUS_NUM_RESOURCES; i++) {
234 		struct resource *r = bus->resource[i];
235 		if (!r)
236 			continue;
237 		if (res->start && !(res->start >= r->start && res->end <= r->end))
238 			continue;	/* Not contained */
239 		if ((res->flags ^ r->flags) & (IORESOURCE_IO | IORESOURCE_MEM))
240 			continue;	/* Wrong type */
241 		if (!((res->flags ^ r->flags) & IORESOURCE_PREFETCH))
242 			return r;	/* Exact match */
243 		if ((res->flags & IORESOURCE_PREFETCH) && !(r->flags & IORESOURCE_PREFETCH))
244 			best = r;	/* Approximating prefetchable by non-prefetchable */
245 	}
246 	return best;
247 }
248 
249 /**
250  * pci_restore_bars - restore a devices BAR values (e.g. after wake-up)
251  * @dev: PCI device to have its BARs restored
252  *
253  * Restore the BAR values for a given device, so as to make it
254  * accessible by its driver.
255  */
256 void
257 pci_restore_bars(struct pci_dev *dev)
258 {
259 	int i, numres;
260 
261 	switch (dev->hdr_type) {
262 	case PCI_HEADER_TYPE_NORMAL:
263 		numres = 6;
264 		break;
265 	case PCI_HEADER_TYPE_BRIDGE:
266 		numres = 2;
267 		break;
268 	case PCI_HEADER_TYPE_CARDBUS:
269 		numres = 1;
270 		break;
271 	default:
272 		/* Should never get here, but just in case... */
273 		return;
274 	}
275 
276 	for (i = 0; i < numres; i ++)
277 		pci_update_resource(dev, &dev->resource[i], i);
278 }
279 
280 int (*platform_pci_set_power_state)(struct pci_dev *dev, pci_power_t t);
281 
282 /**
283  * pci_set_power_state - Set the power state of a PCI device
284  * @dev: PCI device to be suspended
285  * @state: PCI power state (D0, D1, D2, D3hot, D3cold) we're entering
286  *
287  * Transition a device to a new power state, using the Power Management
288  * Capabilities in the device's config space.
289  *
290  * RETURN VALUE:
291  * -EINVAL if trying to enter a lower state than we're already in.
292  * 0 if we're already in the requested state.
293  * -EIO if device does not support PCI PM.
294  * 0 if we can successfully change the power state.
295  */
296 int
297 pci_set_power_state(struct pci_dev *dev, pci_power_t state)
298 {
299 	int pm, need_restore = 0;
300 	u16 pmcsr, pmc;
301 
302 	/* bound the state we're entering */
303 	if (state > PCI_D3hot)
304 		state = PCI_D3hot;
305 
306 	/* Validate current state:
307 	 * Can enter D0 from any state, but if we can only go deeper
308 	 * to sleep if we're already in a low power state
309 	 */
310 	if (state != PCI_D0 && dev->current_state > state) {
311 		printk(KERN_ERR "%s(): %s: state=%d, current state=%d\n",
312 			__FUNCTION__, pci_name(dev), state, dev->current_state);
313 		return -EINVAL;
314 	} else if (dev->current_state == state)
315 		return 0;        /* we're already there */
316 
317 	/* find PCI PM capability in list */
318 	pm = pci_find_capability(dev, PCI_CAP_ID_PM);
319 
320 	/* abort if the device doesn't support PM capabilities */
321 	if (!pm)
322 		return -EIO;
323 
324 	pci_read_config_word(dev,pm + PCI_PM_PMC,&pmc);
325 	if ((pmc & PCI_PM_CAP_VER_MASK) > 3) {
326 		printk(KERN_DEBUG
327 		       "PCI: %s has unsupported PM cap regs version (%u)\n",
328 		       pci_name(dev), pmc & PCI_PM_CAP_VER_MASK);
329 		return -EIO;
330 	}
331 
332 	/* check if this device supports the desired state */
333 	if (state == PCI_D1 && !(pmc & PCI_PM_CAP_D1))
334 		return -EIO;
335 	else if (state == PCI_D2 && !(pmc & PCI_PM_CAP_D2))
336 		return -EIO;
337 
338 	pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr);
339 
340 	/* If we're (effectively) in D3, force entire word to 0.
341 	 * This doesn't affect PME_Status, disables PME_En, and
342 	 * sets PowerState to 0.
343 	 */
344 	switch (dev->current_state) {
345 	case PCI_D0:
346 	case PCI_D1:
347 	case PCI_D2:
348 		pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
349 		pmcsr |= state;
350 		break;
351 	case PCI_UNKNOWN: /* Boot-up */
352 		if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot
353 		 && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))
354 			need_restore = 1;
355 		/* Fall-through: force to D0 */
356 	default:
357 		pmcsr = 0;
358 		break;
359 	}
360 
361 	/* enter specified state */
362 	pci_write_config_word(dev, pm + PCI_PM_CTRL, pmcsr);
363 
364 	/* Mandatory power management transition delays */
365 	/* see PCI PM 1.1 5.6.1 table 18 */
366 	if (state == PCI_D3hot || dev->current_state == PCI_D3hot)
367 		msleep(10);
368 	else if (state == PCI_D2 || dev->current_state == PCI_D2)
369 		udelay(200);
370 
371 	/*
372 	 * Give firmware a chance to be called, such as ACPI _PRx, _PSx
373 	 * Firmware method after natice method ?
374 	 */
375 	if (platform_pci_set_power_state)
376 		platform_pci_set_power_state(dev, state);
377 
378 	dev->current_state = state;
379 
380 	/* According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT
381 	 * INTERFACE SPECIFICATION, REV. 1.2", a device transitioning
382 	 * from D3hot to D0 _may_ perform an internal reset, thereby
383 	 * going to "D0 Uninitialized" rather than "D0 Initialized".
384 	 * For example, at least some versions of the 3c905B and the
385 	 * 3c556B exhibit this behaviour.
386 	 *
387 	 * At least some laptop BIOSen (e.g. the Thinkpad T21) leave
388 	 * devices in a D3hot state at boot.  Consequently, we need to
389 	 * restore at least the BARs so that the device will be
390 	 * accessible to its driver.
391 	 */
392 	if (need_restore)
393 		pci_restore_bars(dev);
394 
395 	return 0;
396 }
397 
398 int (*platform_pci_choose_state)(struct pci_dev *dev, pm_message_t state);
399 
400 /**
401  * pci_choose_state - Choose the power state of a PCI device
402  * @dev: PCI device to be suspended
403  * @state: target sleep state for the whole system. This is the value
404  *	that is passed to suspend() function.
405  *
406  * Returns PCI power state suitable for given device and given system
407  * message.
408  */
409 
410 pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state)
411 {
412 	int ret;
413 
414 	if (!pci_find_capability(dev, PCI_CAP_ID_PM))
415 		return PCI_D0;
416 
417 	if (platform_pci_choose_state) {
418 		ret = platform_pci_choose_state(dev, state);
419 		if (ret >= 0)
420 			state.event = ret;
421 	}
422 
423 	switch (state.event) {
424 	case PM_EVENT_ON:
425 		return PCI_D0;
426 	case PM_EVENT_FREEZE:
427 	case PM_EVENT_SUSPEND:
428 		return PCI_D3hot;
429 	default:
430 		printk("They asked me for state %d\n", state.event);
431 		BUG();
432 	}
433 	return PCI_D0;
434 }
435 
436 EXPORT_SYMBOL(pci_choose_state);
437 
438 /**
439  * pci_save_state - save the PCI configuration space of a device before suspending
440  * @dev: - PCI device that we're dealing with
441  */
442 int
443 pci_save_state(struct pci_dev *dev)
444 {
445 	int i;
446 	/* XXX: 100% dword access ok here? */
447 	for (i = 0; i < 16; i++)
448 		pci_read_config_dword(dev, i * 4,&dev->saved_config_space[i]);
449 	if ((i = pci_save_msi_state(dev)) != 0)
450 		return i;
451 	if ((i = pci_save_msix_state(dev)) != 0)
452 		return i;
453 	return 0;
454 }
455 
456 /**
457  * pci_restore_state - Restore the saved state of a PCI device
458  * @dev: - PCI device that we're dealing with
459  */
460 int
461 pci_restore_state(struct pci_dev *dev)
462 {
463 	int i;
464 
465 	for (i = 0; i < 16; i++)
466 		pci_write_config_dword(dev,i * 4, dev->saved_config_space[i]);
467 	pci_restore_msi_state(dev);
468 	pci_restore_msix_state(dev);
469 	return 0;
470 }
471 
472 /**
473  * pci_enable_device_bars - Initialize some of a device for use
474  * @dev: PCI device to be initialized
475  * @bars: bitmask of BAR's that must be configured
476  *
477  *  Initialize device before it's used by a driver. Ask low-level code
478  *  to enable selected I/O and memory resources. Wake up the device if it
479  *  was suspended. Beware, this function can fail.
480  */
481 
482 int
483 pci_enable_device_bars(struct pci_dev *dev, int bars)
484 {
485 	int err;
486 
487 	err = pci_set_power_state(dev, PCI_D0);
488 	if (err < 0 && err != -EIO)
489 		return err;
490 	err = pcibios_enable_device(dev, bars);
491 	if (err < 0)
492 		return err;
493 	return 0;
494 }
495 
496 /**
497  * pci_enable_device - Initialize device before it's used by a driver.
498  * @dev: PCI device to be initialized
499  *
500  *  Initialize device before it's used by a driver. Ask low-level code
501  *  to enable I/O and memory. Wake up the device if it was suspended.
502  *  Beware, this function can fail.
503  */
504 int
505 pci_enable_device(struct pci_dev *dev)
506 {
507 	int err = pci_enable_device_bars(dev, (1 << PCI_NUM_RESOURCES) - 1);
508 	if (err)
509 		return err;
510 	pci_fixup_device(pci_fixup_enable, dev);
511 	dev->is_enabled = 1;
512 	return 0;
513 }
514 
515 /**
516  * pcibios_disable_device - disable arch specific PCI resources for device dev
517  * @dev: the PCI device to disable
518  *
519  * Disables architecture specific PCI resources for the device. This
520  * is the default implementation. Architecture implementations can
521  * override this.
522  */
523 void __attribute__ ((weak)) pcibios_disable_device (struct pci_dev *dev) {}
524 
525 /**
526  * pci_disable_device - Disable PCI device after use
527  * @dev: PCI device to be disabled
528  *
529  * Signal to the system that the PCI device is not in use by the system
530  * anymore.  This only involves disabling PCI bus-mastering, if active.
531  */
532 void
533 pci_disable_device(struct pci_dev *dev)
534 {
535 	u16 pci_command;
536 
537 	pci_read_config_word(dev, PCI_COMMAND, &pci_command);
538 	if (pci_command & PCI_COMMAND_MASTER) {
539 		pci_command &= ~PCI_COMMAND_MASTER;
540 		pci_write_config_word(dev, PCI_COMMAND, pci_command);
541 	}
542 	dev->is_busmaster = 0;
543 
544 	pcibios_disable_device(dev);
545 	dev->is_enabled = 0;
546 }
547 
548 /**
549  * pci_enable_wake - enable device to generate PME# when suspended
550  * @dev: - PCI device to operate on
551  * @state: - Current state of device.
552  * @enable: - Flag to enable or disable generation
553  *
554  * Set the bits in the device's PM Capabilities to generate PME# when
555  * the system is suspended.
556  *
557  * -EIO is returned if device doesn't have PM Capabilities.
558  * -EINVAL is returned if device supports it, but can't generate wake events.
559  * 0 if operation is successful.
560  *
561  */
562 int pci_enable_wake(struct pci_dev *dev, pci_power_t state, int enable)
563 {
564 	int pm;
565 	u16 value;
566 
567 	/* find PCI PM capability in list */
568 	pm = pci_find_capability(dev, PCI_CAP_ID_PM);
569 
570 	/* If device doesn't support PM Capabilities, but request is to disable
571 	 * wake events, it's a nop; otherwise fail */
572 	if (!pm)
573 		return enable ? -EIO : 0;
574 
575 	/* Check device's ability to generate PME# */
576 	pci_read_config_word(dev,pm+PCI_PM_PMC,&value);
577 
578 	value &= PCI_PM_CAP_PME_MASK;
579 	value >>= ffs(PCI_PM_CAP_PME_MASK) - 1;   /* First bit of mask */
580 
581 	/* Check if it can generate PME# from requested state. */
582 	if (!value || !(value & (1 << state)))
583 		return enable ? -EINVAL : 0;
584 
585 	pci_read_config_word(dev, pm + PCI_PM_CTRL, &value);
586 
587 	/* Clear PME_Status by writing 1 to it and enable PME# */
588 	value |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE;
589 
590 	if (!enable)
591 		value &= ~PCI_PM_CTRL_PME_ENABLE;
592 
593 	pci_write_config_word(dev, pm + PCI_PM_CTRL, value);
594 
595 	return 0;
596 }
597 
598 int
599 pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge)
600 {
601 	u8 pin;
602 
603 	pin = dev->pin;
604 	if (!pin)
605 		return -1;
606 	pin--;
607 	while (dev->bus->self) {
608 		pin = (pin + PCI_SLOT(dev->devfn)) % 4;
609 		dev = dev->bus->self;
610 	}
611 	*bridge = dev;
612 	return pin;
613 }
614 
615 /**
616  *	pci_release_region - Release a PCI bar
617  *	@pdev: PCI device whose resources were previously reserved by pci_request_region
618  *	@bar: BAR to release
619  *
620  *	Releases the PCI I/O and memory resources previously reserved by a
621  *	successful call to pci_request_region.  Call this function only
622  *	after all use of the PCI regions has ceased.
623  */
624 void pci_release_region(struct pci_dev *pdev, int bar)
625 {
626 	if (pci_resource_len(pdev, bar) == 0)
627 		return;
628 	if (pci_resource_flags(pdev, bar) & IORESOURCE_IO)
629 		release_region(pci_resource_start(pdev, bar),
630 				pci_resource_len(pdev, bar));
631 	else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM)
632 		release_mem_region(pci_resource_start(pdev, bar),
633 				pci_resource_len(pdev, bar));
634 }
635 
636 /**
637  *	pci_request_region - Reserved PCI I/O and memory resource
638  *	@pdev: PCI device whose resources are to be reserved
639  *	@bar: BAR to be reserved
640  *	@res_name: Name to be associated with resource.
641  *
642  *	Mark the PCI region associated with PCI device @pdev BR @bar as
643  *	being reserved by owner @res_name.  Do not access any
644  *	address inside the PCI regions unless this call returns
645  *	successfully.
646  *
647  *	Returns 0 on success, or %EBUSY on error.  A warning
648  *	message is also printed on failure.
649  */
650 int pci_request_region(struct pci_dev *pdev, int bar, const char *res_name)
651 {
652 	if (pci_resource_len(pdev, bar) == 0)
653 		return 0;
654 
655 	if (pci_resource_flags(pdev, bar) & IORESOURCE_IO) {
656 		if (!request_region(pci_resource_start(pdev, bar),
657 			    pci_resource_len(pdev, bar), res_name))
658 			goto err_out;
659 	}
660 	else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM) {
661 		if (!request_mem_region(pci_resource_start(pdev, bar),
662 				        pci_resource_len(pdev, bar), res_name))
663 			goto err_out;
664 	}
665 
666 	return 0;
667 
668 err_out:
669 	printk (KERN_WARNING "PCI: Unable to reserve %s region #%d:%lx@%lx for device %s\n",
670 		pci_resource_flags(pdev, bar) & IORESOURCE_IO ? "I/O" : "mem",
671 		bar + 1, /* PCI BAR # */
672 		pci_resource_len(pdev, bar), pci_resource_start(pdev, bar),
673 		pci_name(pdev));
674 	return -EBUSY;
675 }
676 
677 
678 /**
679  *	pci_release_regions - Release reserved PCI I/O and memory resources
680  *	@pdev: PCI device whose resources were previously reserved by pci_request_regions
681  *
682  *	Releases all PCI I/O and memory resources previously reserved by a
683  *	successful call to pci_request_regions.  Call this function only
684  *	after all use of the PCI regions has ceased.
685  */
686 
687 void pci_release_regions(struct pci_dev *pdev)
688 {
689 	int i;
690 
691 	for (i = 0; i < 6; i++)
692 		pci_release_region(pdev, i);
693 }
694 
695 /**
696  *	pci_request_regions - Reserved PCI I/O and memory resources
697  *	@pdev: PCI device whose resources are to be reserved
698  *	@res_name: Name to be associated with resource.
699  *
700  *	Mark all PCI regions associated with PCI device @pdev as
701  *	being reserved by owner @res_name.  Do not access any
702  *	address inside the PCI regions unless this call returns
703  *	successfully.
704  *
705  *	Returns 0 on success, or %EBUSY on error.  A warning
706  *	message is also printed on failure.
707  */
708 int pci_request_regions(struct pci_dev *pdev, const char *res_name)
709 {
710 	int i;
711 
712 	for (i = 0; i < 6; i++)
713 		if(pci_request_region(pdev, i, res_name))
714 			goto err_out;
715 	return 0;
716 
717 err_out:
718 	while(--i >= 0)
719 		pci_release_region(pdev, i);
720 
721 	return -EBUSY;
722 }
723 
724 /**
725  * pci_set_master - enables bus-mastering for device dev
726  * @dev: the PCI device to enable
727  *
728  * Enables bus-mastering on the device and calls pcibios_set_master()
729  * to do the needed arch specific settings.
730  */
731 void
732 pci_set_master(struct pci_dev *dev)
733 {
734 	u16 cmd;
735 
736 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
737 	if (! (cmd & PCI_COMMAND_MASTER)) {
738 		pr_debug("PCI: Enabling bus mastering for device %s\n", pci_name(dev));
739 		cmd |= PCI_COMMAND_MASTER;
740 		pci_write_config_word(dev, PCI_COMMAND, cmd);
741 	}
742 	dev->is_busmaster = 1;
743 	pcibios_set_master(dev);
744 }
745 
746 #ifndef HAVE_ARCH_PCI_MWI
747 /* This can be overridden by arch code. */
748 u8 pci_cache_line_size = L1_CACHE_BYTES >> 2;
749 
750 /**
751  * pci_generic_prep_mwi - helper function for pci_set_mwi
752  * @dev: the PCI device for which MWI is enabled
753  *
754  * Helper function for generic implementation of pcibios_prep_mwi
755  * function.  Originally copied from drivers/net/acenic.c.
756  * Copyright 1998-2001 by Jes Sorensen, <jes@trained-monkey.org>.
757  *
758  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
759  */
760 static int
761 pci_generic_prep_mwi(struct pci_dev *dev)
762 {
763 	u8 cacheline_size;
764 
765 	if (!pci_cache_line_size)
766 		return -EINVAL;		/* The system doesn't support MWI. */
767 
768 	/* Validate current setting: the PCI_CACHE_LINE_SIZE must be
769 	   equal to or multiple of the right value. */
770 	pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
771 	if (cacheline_size >= pci_cache_line_size &&
772 	    (cacheline_size % pci_cache_line_size) == 0)
773 		return 0;
774 
775 	/* Write the correct value. */
776 	pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, pci_cache_line_size);
777 	/* Read it back. */
778 	pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
779 	if (cacheline_size == pci_cache_line_size)
780 		return 0;
781 
782 	printk(KERN_DEBUG "PCI: cache line size of %d is not supported "
783 	       "by device %s\n", pci_cache_line_size << 2, pci_name(dev));
784 
785 	return -EINVAL;
786 }
787 #endif /* !HAVE_ARCH_PCI_MWI */
788 
789 /**
790  * pci_set_mwi - enables memory-write-invalidate PCI transaction
791  * @dev: the PCI device for which MWI is enabled
792  *
793  * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND,
794  * and then calls @pcibios_set_mwi to do the needed arch specific
795  * operations or a generic mwi-prep function.
796  *
797  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
798  */
799 int
800 pci_set_mwi(struct pci_dev *dev)
801 {
802 	int rc;
803 	u16 cmd;
804 
805 #ifdef HAVE_ARCH_PCI_MWI
806 	rc = pcibios_prep_mwi(dev);
807 #else
808 	rc = pci_generic_prep_mwi(dev);
809 #endif
810 
811 	if (rc)
812 		return rc;
813 
814 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
815 	if (! (cmd & PCI_COMMAND_INVALIDATE)) {
816 		pr_debug("PCI: Enabling Mem-Wr-Inval for device %s\n", pci_name(dev));
817 		cmd |= PCI_COMMAND_INVALIDATE;
818 		pci_write_config_word(dev, PCI_COMMAND, cmd);
819 	}
820 
821 	return 0;
822 }
823 
824 /**
825  * pci_clear_mwi - disables Memory-Write-Invalidate for device dev
826  * @dev: the PCI device to disable
827  *
828  * Disables PCI Memory-Write-Invalidate transaction on the device
829  */
830 void
831 pci_clear_mwi(struct pci_dev *dev)
832 {
833 	u16 cmd;
834 
835 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
836 	if (cmd & PCI_COMMAND_INVALIDATE) {
837 		cmd &= ~PCI_COMMAND_INVALIDATE;
838 		pci_write_config_word(dev, PCI_COMMAND, cmd);
839 	}
840 }
841 
842 /**
843  * pci_intx - enables/disables PCI INTx for device dev
844  * @pdev: the PCI device to operate on
845  * @enable: boolean: whether to enable or disable PCI INTx
846  *
847  * Enables/disables PCI INTx for device dev
848  */
849 void
850 pci_intx(struct pci_dev *pdev, int enable)
851 {
852 	u16 pci_command, new;
853 
854 	pci_read_config_word(pdev, PCI_COMMAND, &pci_command);
855 
856 	if (enable) {
857 		new = pci_command & ~PCI_COMMAND_INTX_DISABLE;
858 	} else {
859 		new = pci_command | PCI_COMMAND_INTX_DISABLE;
860 	}
861 
862 	if (new != pci_command) {
863 		pci_write_config_word(pdev, PCI_COMMAND, new);
864 	}
865 }
866 
867 #ifndef HAVE_ARCH_PCI_SET_DMA_MASK
868 /*
869  * These can be overridden by arch-specific implementations
870  */
871 int
872 pci_set_dma_mask(struct pci_dev *dev, u64 mask)
873 {
874 	if (!pci_dma_supported(dev, mask))
875 		return -EIO;
876 
877 	dev->dma_mask = mask;
878 
879 	return 0;
880 }
881 
882 int
883 pci_set_consistent_dma_mask(struct pci_dev *dev, u64 mask)
884 {
885 	if (!pci_dma_supported(dev, mask))
886 		return -EIO;
887 
888 	dev->dev.coherent_dma_mask = mask;
889 
890 	return 0;
891 }
892 #endif
893 
894 static int __devinit pci_init(void)
895 {
896 	struct pci_dev *dev = NULL;
897 
898 	while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
899 		pci_fixup_device(pci_fixup_final, dev);
900 	}
901 	return 0;
902 }
903 
904 static int __devinit pci_setup(char *str)
905 {
906 	while (str) {
907 		char *k = strchr(str, ',');
908 		if (k)
909 			*k++ = 0;
910 		if (*str && (str = pcibios_setup(str)) && *str) {
911 			if (!strcmp(str, "nomsi")) {
912 				pci_no_msi();
913 			} else {
914 				printk(KERN_ERR "PCI: Unknown option `%s'\n",
915 						str);
916 			}
917 		}
918 		str = k;
919 	}
920 	return 1;
921 }
922 
923 device_initcall(pci_init);
924 
925 __setup("pci=", pci_setup);
926 
927 #if defined(CONFIG_ISA) || defined(CONFIG_EISA)
928 /* FIXME: Some boxes have multiple ISA bridges! */
929 struct pci_dev *isa_bridge;
930 EXPORT_SYMBOL(isa_bridge);
931 #endif
932 
933 EXPORT_SYMBOL_GPL(pci_restore_bars);
934 EXPORT_SYMBOL(pci_enable_device_bars);
935 EXPORT_SYMBOL(pci_enable_device);
936 EXPORT_SYMBOL(pci_disable_device);
937 EXPORT_SYMBOL(pci_find_capability);
938 EXPORT_SYMBOL(pci_bus_find_capability);
939 EXPORT_SYMBOL(pci_release_regions);
940 EXPORT_SYMBOL(pci_request_regions);
941 EXPORT_SYMBOL(pci_release_region);
942 EXPORT_SYMBOL(pci_request_region);
943 EXPORT_SYMBOL(pci_set_master);
944 EXPORT_SYMBOL(pci_set_mwi);
945 EXPORT_SYMBOL(pci_clear_mwi);
946 EXPORT_SYMBOL_GPL(pci_intx);
947 EXPORT_SYMBOL(pci_set_dma_mask);
948 EXPORT_SYMBOL(pci_set_consistent_dma_mask);
949 EXPORT_SYMBOL(pci_assign_resource);
950 EXPORT_SYMBOL(pci_find_parent_resource);
951 
952 EXPORT_SYMBOL(pci_set_power_state);
953 EXPORT_SYMBOL(pci_save_state);
954 EXPORT_SYMBOL(pci_restore_state);
955 EXPORT_SYMBOL(pci_enable_wake);
956 
957 /* Quirk info */
958 
959 EXPORT_SYMBOL(isa_dma_bridge_buggy);
960 EXPORT_SYMBOL(pci_pci_problems);
961