xref: /linux/drivers/pci/pci.c (revision 99b5aa3c10c7cff1e97239fda93649222fc12d25)
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 unsigned int pci_pm_d3_delay = 10;
23 
24 /**
25  * pci_bus_max_busnr - returns maximum PCI bus number of given bus' children
26  * @bus: pointer to PCI bus structure to search
27  *
28  * Given a PCI bus, returns the highest PCI bus number present in the set
29  * including the given PCI bus and its list of child PCI buses.
30  */
31 unsigned char __devinit
32 pci_bus_max_busnr(struct pci_bus* bus)
33 {
34 	struct list_head *tmp;
35 	unsigned char max, n;
36 
37 	max = bus->subordinate;
38 	list_for_each(tmp, &bus->children) {
39 		n = pci_bus_max_busnr(pci_bus_b(tmp));
40 		if(n > max)
41 			max = n;
42 	}
43 	return max;
44 }
45 EXPORT_SYMBOL_GPL(pci_bus_max_busnr);
46 
47 #if 0
48 /**
49  * pci_max_busnr - returns maximum PCI bus number
50  *
51  * Returns the highest PCI bus number present in the system global list of
52  * PCI buses.
53  */
54 unsigned char __devinit
55 pci_max_busnr(void)
56 {
57 	struct pci_bus *bus = NULL;
58 	unsigned char max, n;
59 
60 	max = 0;
61 	while ((bus = pci_find_next_bus(bus)) != NULL) {
62 		n = pci_bus_max_busnr(bus);
63 		if(n > max)
64 			max = n;
65 	}
66 	return max;
67 }
68 
69 #endif  /*  0  */
70 
71 static int __pci_find_next_cap(struct pci_bus *bus, unsigned int devfn, u8 pos, int cap)
72 {
73 	u8 id;
74 	int ttl = 48;
75 
76 	while (ttl--) {
77 		pci_bus_read_config_byte(bus, devfn, pos, &pos);
78 		if (pos < 0x40)
79 			break;
80 		pos &= ~3;
81 		pci_bus_read_config_byte(bus, devfn, pos + PCI_CAP_LIST_ID,
82 					 &id);
83 		if (id == 0xff)
84 			break;
85 		if (id == cap)
86 			return pos;
87 		pos += PCI_CAP_LIST_NEXT;
88 	}
89 	return 0;
90 }
91 
92 int pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap)
93 {
94 	return __pci_find_next_cap(dev->bus, dev->devfn,
95 				   pos + PCI_CAP_LIST_NEXT, cap);
96 }
97 EXPORT_SYMBOL_GPL(pci_find_next_capability);
98 
99 static int __pci_bus_find_cap(struct pci_bus *bus, unsigned int devfn, u8 hdr_type, int cap)
100 {
101 	u16 status;
102 	u8 pos;
103 
104 	pci_bus_read_config_word(bus, devfn, PCI_STATUS, &status);
105 	if (!(status & PCI_STATUS_CAP_LIST))
106 		return 0;
107 
108 	switch (hdr_type) {
109 	case PCI_HEADER_TYPE_NORMAL:
110 	case PCI_HEADER_TYPE_BRIDGE:
111 		pos = PCI_CAPABILITY_LIST;
112 		break;
113 	case PCI_HEADER_TYPE_CARDBUS:
114 		pos = PCI_CB_CAPABILITY_LIST;
115 		break;
116 	default:
117 		return 0;
118 	}
119 	return __pci_find_next_cap(bus, devfn, pos, cap);
120 }
121 
122 /**
123  * pci_find_capability - query for devices' capabilities
124  * @dev: PCI device to query
125  * @cap: capability code
126  *
127  * Tell if a device supports a given PCI capability.
128  * Returns the address of the requested capability structure within the
129  * device's PCI configuration space or 0 in case the device does not
130  * support it.  Possible values for @cap:
131  *
132  *  %PCI_CAP_ID_PM           Power Management
133  *  %PCI_CAP_ID_AGP          Accelerated Graphics Port
134  *  %PCI_CAP_ID_VPD          Vital Product Data
135  *  %PCI_CAP_ID_SLOTID       Slot Identification
136  *  %PCI_CAP_ID_MSI          Message Signalled Interrupts
137  *  %PCI_CAP_ID_CHSWP        CompactPCI HotSwap
138  *  %PCI_CAP_ID_PCIX         PCI-X
139  *  %PCI_CAP_ID_EXP          PCI Express
140  */
141 int pci_find_capability(struct pci_dev *dev, int cap)
142 {
143 	return __pci_bus_find_cap(dev->bus, dev->devfn, dev->hdr_type, cap);
144 }
145 
146 /**
147  * pci_bus_find_capability - query for devices' capabilities
148  * @bus:   the PCI bus to query
149  * @devfn: PCI device to query
150  * @cap:   capability code
151  *
152  * Like pci_find_capability() but works for pci devices that do not have a
153  * pci_dev structure set up yet.
154  *
155  * Returns the address of the requested capability structure within the
156  * device's PCI configuration space or 0 in case the device does not
157  * support it.
158  */
159 int pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap)
160 {
161 	u8 hdr_type;
162 
163 	pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &hdr_type);
164 
165 	return __pci_bus_find_cap(bus, devfn, hdr_type & 0x7f, cap);
166 }
167 
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 EXPORT_SYMBOL_GPL(pci_find_ext_capability);
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 	/*
318 	 * If the device or the parent bridge can't support PCI PM, ignore
319 	 * the request if we're doing anything besides putting it into D0
320 	 * (which would only happen on boot).
321 	 */
322 	if ((state == PCI_D1 || state == PCI_D2) && pci_no_d1d2(dev))
323 		return 0;
324 
325 	/* find PCI PM capability in list */
326 	pm = pci_find_capability(dev, PCI_CAP_ID_PM);
327 
328 	/* abort if the device doesn't support PM capabilities */
329 	if (!pm)
330 		return -EIO;
331 
332 	pci_read_config_word(dev,pm + PCI_PM_PMC,&pmc);
333 	if ((pmc & PCI_PM_CAP_VER_MASK) > 3) {
334 		printk(KERN_DEBUG
335 		       "PCI: %s has unsupported PM cap regs version (%u)\n",
336 		       pci_name(dev), pmc & PCI_PM_CAP_VER_MASK);
337 		return -EIO;
338 	}
339 
340 	/* check if this device supports the desired state */
341 	if (state == PCI_D1 && !(pmc & PCI_PM_CAP_D1))
342 		return -EIO;
343 	else if (state == PCI_D2 && !(pmc & PCI_PM_CAP_D2))
344 		return -EIO;
345 
346 	pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr);
347 
348 	/* If we're (effectively) in D3, force entire word to 0.
349 	 * This doesn't affect PME_Status, disables PME_En, and
350 	 * sets PowerState to 0.
351 	 */
352 	switch (dev->current_state) {
353 	case PCI_D0:
354 	case PCI_D1:
355 	case PCI_D2:
356 		pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
357 		pmcsr |= state;
358 		break;
359 	case PCI_UNKNOWN: /* Boot-up */
360 		if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot
361 		 && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))
362 			need_restore = 1;
363 		/* Fall-through: force to D0 */
364 	default:
365 		pmcsr = 0;
366 		break;
367 	}
368 
369 	/* enter specified state */
370 	pci_write_config_word(dev, pm + PCI_PM_CTRL, pmcsr);
371 
372 	/* Mandatory power management transition delays */
373 	/* see PCI PM 1.1 5.6.1 table 18 */
374 	if (state == PCI_D3hot || dev->current_state == PCI_D3hot)
375 		msleep(pci_pm_d3_delay);
376 	else if (state == PCI_D2 || dev->current_state == PCI_D2)
377 		udelay(200);
378 
379 	/*
380 	 * Give firmware a chance to be called, such as ACPI _PRx, _PSx
381 	 * Firmware method after native method ?
382 	 */
383 	if (platform_pci_set_power_state)
384 		platform_pci_set_power_state(dev, state);
385 
386 	dev->current_state = state;
387 
388 	/* According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT
389 	 * INTERFACE SPECIFICATION, REV. 1.2", a device transitioning
390 	 * from D3hot to D0 _may_ perform an internal reset, thereby
391 	 * going to "D0 Uninitialized" rather than "D0 Initialized".
392 	 * For example, at least some versions of the 3c905B and the
393 	 * 3c556B exhibit this behaviour.
394 	 *
395 	 * At least some laptop BIOSen (e.g. the Thinkpad T21) leave
396 	 * devices in a D3hot state at boot.  Consequently, we need to
397 	 * restore at least the BARs so that the device will be
398 	 * accessible to its driver.
399 	 */
400 	if (need_restore)
401 		pci_restore_bars(dev);
402 
403 	return 0;
404 }
405 
406 int (*platform_pci_choose_state)(struct pci_dev *dev, pm_message_t state);
407 
408 /**
409  * pci_choose_state - Choose the power state of a PCI device
410  * @dev: PCI device to be suspended
411  * @state: target sleep state for the whole system. This is the value
412  *	that is passed to suspend() function.
413  *
414  * Returns PCI power state suitable for given device and given system
415  * message.
416  */
417 
418 pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state)
419 {
420 	int ret;
421 
422 	if (!pci_find_capability(dev, PCI_CAP_ID_PM))
423 		return PCI_D0;
424 
425 	if (platform_pci_choose_state) {
426 		ret = platform_pci_choose_state(dev, state);
427 		if (ret >= 0)
428 			state.event = ret;
429 	}
430 
431 	switch (state.event) {
432 	case PM_EVENT_ON:
433 		return PCI_D0;
434 	case PM_EVENT_FREEZE:
435 	case PM_EVENT_PRETHAW:
436 		/* REVISIT both freeze and pre-thaw "should" use D0 */
437 	case PM_EVENT_SUSPEND:
438 		return PCI_D3hot;
439 	default:
440 		printk("Unrecognized suspend event %d\n", state.event);
441 		BUG();
442 	}
443 	return PCI_D0;
444 }
445 
446 EXPORT_SYMBOL(pci_choose_state);
447 
448 static int pci_save_pcie_state(struct pci_dev *dev)
449 {
450 	int pos, i = 0;
451 	struct pci_cap_saved_state *save_state;
452 	u16 *cap;
453 
454 	pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
455 	if (pos <= 0)
456 		return 0;
457 
458 	save_state = kzalloc(sizeof(*save_state) + sizeof(u16) * 4, GFP_KERNEL);
459 	if (!save_state) {
460 		dev_err(&dev->dev, "Out of memory in pci_save_pcie_state\n");
461 		return -ENOMEM;
462 	}
463 	cap = (u16 *)&save_state->data[0];
464 
465 	pci_read_config_word(dev, pos + PCI_EXP_DEVCTL, &cap[i++]);
466 	pci_read_config_word(dev, pos + PCI_EXP_LNKCTL, &cap[i++]);
467 	pci_read_config_word(dev, pos + PCI_EXP_SLTCTL, &cap[i++]);
468 	pci_read_config_word(dev, pos + PCI_EXP_RTCTL, &cap[i++]);
469 	pci_add_saved_cap(dev, save_state);
470 	return 0;
471 }
472 
473 static void pci_restore_pcie_state(struct pci_dev *dev)
474 {
475 	int i = 0, pos;
476 	struct pci_cap_saved_state *save_state;
477 	u16 *cap;
478 
479 	save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
480 	pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
481 	if (!save_state || pos <= 0)
482 		return;
483 	cap = (u16 *)&save_state->data[0];
484 
485 	pci_write_config_word(dev, pos + PCI_EXP_DEVCTL, cap[i++]);
486 	pci_write_config_word(dev, pos + PCI_EXP_LNKCTL, cap[i++]);
487 	pci_write_config_word(dev, pos + PCI_EXP_SLTCTL, cap[i++]);
488 	pci_write_config_word(dev, pos + PCI_EXP_RTCTL, cap[i++]);
489 	pci_remove_saved_cap(save_state);
490 	kfree(save_state);
491 }
492 
493 
494 static int pci_save_pcix_state(struct pci_dev *dev)
495 {
496 	int pos, i = 0;
497 	struct pci_cap_saved_state *save_state;
498 	u16 *cap;
499 
500 	pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
501 	if (pos <= 0)
502 		return 0;
503 
504 	save_state = kzalloc(sizeof(*save_state) + sizeof(u16), GFP_KERNEL);
505 	if (!save_state) {
506 		dev_err(&dev->dev, "Out of memory in pci_save_pcie_state\n");
507 		return -ENOMEM;
508 	}
509 	cap = (u16 *)&save_state->data[0];
510 
511 	pci_read_config_word(dev, pos + PCI_X_CMD, &cap[i++]);
512 	pci_add_saved_cap(dev, save_state);
513 	return 0;
514 }
515 
516 static void pci_restore_pcix_state(struct pci_dev *dev)
517 {
518 	int i = 0, pos;
519 	struct pci_cap_saved_state *save_state;
520 	u16 *cap;
521 
522 	save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX);
523 	pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
524 	if (!save_state || pos <= 0)
525 		return;
526 	cap = (u16 *)&save_state->data[0];
527 
528 	pci_write_config_word(dev, pos + PCI_X_CMD, cap[i++]);
529 	pci_remove_saved_cap(save_state);
530 	kfree(save_state);
531 }
532 
533 
534 /**
535  * pci_save_state - save the PCI configuration space of a device before suspending
536  * @dev: - PCI device that we're dealing with
537  */
538 int
539 pci_save_state(struct pci_dev *dev)
540 {
541 	int i;
542 	/* XXX: 100% dword access ok here? */
543 	for (i = 0; i < 16; i++)
544 		pci_read_config_dword(dev, i * 4,&dev->saved_config_space[i]);
545 	if ((i = pci_save_msi_state(dev)) != 0)
546 		return i;
547 	if ((i = pci_save_msix_state(dev)) != 0)
548 		return i;
549 	if ((i = pci_save_pcie_state(dev)) != 0)
550 		return i;
551 	if ((i = pci_save_pcix_state(dev)) != 0)
552 		return i;
553 	return 0;
554 }
555 
556 /**
557  * pci_restore_state - Restore the saved state of a PCI device
558  * @dev: - PCI device that we're dealing with
559  */
560 int
561 pci_restore_state(struct pci_dev *dev)
562 {
563 	int i;
564 	int val;
565 
566 	/* PCI Express register must be restored first */
567 	pci_restore_pcie_state(dev);
568 
569 	/*
570 	 * The Base Address register should be programmed before the command
571 	 * register(s)
572 	 */
573 	for (i = 15; i >= 0; i--) {
574 		pci_read_config_dword(dev, i * 4, &val);
575 		if (val != dev->saved_config_space[i]) {
576 			printk(KERN_DEBUG "PM: Writing back config space on "
577 				"device %s at offset %x (was %x, writing %x)\n",
578 				pci_name(dev), i,
579 				val, (int)dev->saved_config_space[i]);
580 			pci_write_config_dword(dev,i * 4,
581 				dev->saved_config_space[i]);
582 		}
583 	}
584 	pci_restore_pcix_state(dev);
585 	pci_restore_msi_state(dev);
586 	pci_restore_msix_state(dev);
587 	return 0;
588 }
589 
590 /**
591  * pci_enable_device_bars - Initialize some of a device for use
592  * @dev: PCI device to be initialized
593  * @bars: bitmask of BAR's that must be configured
594  *
595  *  Initialize device before it's used by a driver. Ask low-level code
596  *  to enable selected I/O and memory resources. Wake up the device if it
597  *  was suspended. Beware, this function can fail.
598  */
599 
600 int
601 pci_enable_device_bars(struct pci_dev *dev, int bars)
602 {
603 	int err;
604 
605 	err = pci_set_power_state(dev, PCI_D0);
606 	if (err < 0 && err != -EIO)
607 		return err;
608 	err = pcibios_enable_device(dev, bars);
609 	if (err < 0)
610 		return err;
611 	return 0;
612 }
613 
614 /**
615  * __pci_enable_device - Initialize device before it's used by a driver.
616  * @dev: PCI device to be initialized
617  *
618  *  Initialize device before it's used by a driver. Ask low-level code
619  *  to enable I/O and memory. Wake up the device if it was suspended.
620  *  Beware, this function can fail.
621  *
622  * Note this function is a backend and is not supposed to be called by
623  * normal code, use pci_enable_device() instead.
624  */
625 int
626 __pci_enable_device(struct pci_dev *dev)
627 {
628 	int err;
629 
630 	err = pci_enable_device_bars(dev, (1 << PCI_NUM_RESOURCES) - 1);
631 	if (err)
632 		return err;
633 	pci_fixup_device(pci_fixup_enable, dev);
634 	return 0;
635 }
636 
637 /**
638  * pci_enable_device - Initialize device before it's used by a driver.
639  * @dev: PCI device to be initialized
640  *
641  *  Initialize device before it's used by a driver. Ask low-level code
642  *  to enable I/O and memory. Wake up the device if it was suspended.
643  *  Beware, this function can fail.
644  *
645  *  Note we don't actually enable the device many times if we call
646  *  this function repeatedly (we just increment the count).
647  */
648 int pci_enable_device(struct pci_dev *dev)
649 {
650 	int result;
651 	if (atomic_add_return(1, &dev->enable_cnt) > 1)
652 		return 0;		/* already enabled */
653 	result = __pci_enable_device(dev);
654 	if (result < 0)
655 		atomic_dec(&dev->enable_cnt);
656 	return result;
657 }
658 
659 /**
660  * pcibios_disable_device - disable arch specific PCI resources for device dev
661  * @dev: the PCI device to disable
662  *
663  * Disables architecture specific PCI resources for the device. This
664  * is the default implementation. Architecture implementations can
665  * override this.
666  */
667 void __attribute__ ((weak)) pcibios_disable_device (struct pci_dev *dev) {}
668 
669 /**
670  * pci_disable_device - Disable PCI device after use
671  * @dev: PCI device to be disabled
672  *
673  * Signal to the system that the PCI device is not in use by the system
674  * anymore.  This only involves disabling PCI bus-mastering, if active.
675  *
676  * Note we don't actually disable the device until all callers of
677  * pci_device_enable() have called pci_device_disable().
678  */
679 void
680 pci_disable_device(struct pci_dev *dev)
681 {
682 	u16 pci_command;
683 
684 	if (atomic_sub_return(1, &dev->enable_cnt) != 0)
685 		return;
686 
687 	if (dev->msi_enabled)
688 		disable_msi_mode(dev, pci_find_capability(dev, PCI_CAP_ID_MSI),
689 			PCI_CAP_ID_MSI);
690 	if (dev->msix_enabled)
691 		disable_msi_mode(dev, pci_find_capability(dev, PCI_CAP_ID_MSI),
692 			PCI_CAP_ID_MSIX);
693 
694 	pci_read_config_word(dev, PCI_COMMAND, &pci_command);
695 	if (pci_command & PCI_COMMAND_MASTER) {
696 		pci_command &= ~PCI_COMMAND_MASTER;
697 		pci_write_config_word(dev, PCI_COMMAND, pci_command);
698 	}
699 	dev->is_busmaster = 0;
700 
701 	pcibios_disable_device(dev);
702 }
703 
704 /**
705  * pci_enable_wake - enable device to generate PME# when suspended
706  * @dev: - PCI device to operate on
707  * @state: - Current state of device.
708  * @enable: - Flag to enable or disable generation
709  *
710  * Set the bits in the device's PM Capabilities to generate PME# when
711  * the system is suspended.
712  *
713  * -EIO is returned if device doesn't have PM Capabilities.
714  * -EINVAL is returned if device supports it, but can't generate wake events.
715  * 0 if operation is successful.
716  *
717  */
718 int pci_enable_wake(struct pci_dev *dev, pci_power_t state, int enable)
719 {
720 	int pm;
721 	u16 value;
722 
723 	/* find PCI PM capability in list */
724 	pm = pci_find_capability(dev, PCI_CAP_ID_PM);
725 
726 	/* If device doesn't support PM Capabilities, but request is to disable
727 	 * wake events, it's a nop; otherwise fail */
728 	if (!pm)
729 		return enable ? -EIO : 0;
730 
731 	/* Check device's ability to generate PME# */
732 	pci_read_config_word(dev,pm+PCI_PM_PMC,&value);
733 
734 	value &= PCI_PM_CAP_PME_MASK;
735 	value >>= ffs(PCI_PM_CAP_PME_MASK) - 1;   /* First bit of mask */
736 
737 	/* Check if it can generate PME# from requested state. */
738 	if (!value || !(value & (1 << state)))
739 		return enable ? -EINVAL : 0;
740 
741 	pci_read_config_word(dev, pm + PCI_PM_CTRL, &value);
742 
743 	/* Clear PME_Status by writing 1 to it and enable PME# */
744 	value |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE;
745 
746 	if (!enable)
747 		value &= ~PCI_PM_CTRL_PME_ENABLE;
748 
749 	pci_write_config_word(dev, pm + PCI_PM_CTRL, value);
750 
751 	return 0;
752 }
753 
754 int
755 pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge)
756 {
757 	u8 pin;
758 
759 	pin = dev->pin;
760 	if (!pin)
761 		return -1;
762 	pin--;
763 	while (dev->bus->self) {
764 		pin = (pin + PCI_SLOT(dev->devfn)) % 4;
765 		dev = dev->bus->self;
766 	}
767 	*bridge = dev;
768 	return pin;
769 }
770 
771 /**
772  *	pci_release_region - Release a PCI bar
773  *	@pdev: PCI device whose resources were previously reserved by pci_request_region
774  *	@bar: BAR to release
775  *
776  *	Releases the PCI I/O and memory resources previously reserved by a
777  *	successful call to pci_request_region.  Call this function only
778  *	after all use of the PCI regions has ceased.
779  */
780 void pci_release_region(struct pci_dev *pdev, int bar)
781 {
782 	if (pci_resource_len(pdev, bar) == 0)
783 		return;
784 	if (pci_resource_flags(pdev, bar) & IORESOURCE_IO)
785 		release_region(pci_resource_start(pdev, bar),
786 				pci_resource_len(pdev, bar));
787 	else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM)
788 		release_mem_region(pci_resource_start(pdev, bar),
789 				pci_resource_len(pdev, bar));
790 }
791 
792 /**
793  *	pci_request_region - Reserved PCI I/O and memory resource
794  *	@pdev: PCI device whose resources are to be reserved
795  *	@bar: BAR to be reserved
796  *	@res_name: Name to be associated with resource.
797  *
798  *	Mark the PCI region associated with PCI device @pdev BR @bar as
799  *	being reserved by owner @res_name.  Do not access any
800  *	address inside the PCI regions unless this call returns
801  *	successfully.
802  *
803  *	Returns 0 on success, or %EBUSY on error.  A warning
804  *	message is also printed on failure.
805  */
806 int pci_request_region(struct pci_dev *pdev, int bar, const char *res_name)
807 {
808 	if (pci_resource_len(pdev, bar) == 0)
809 		return 0;
810 
811 	if (pci_resource_flags(pdev, bar) & IORESOURCE_IO) {
812 		if (!request_region(pci_resource_start(pdev, bar),
813 			    pci_resource_len(pdev, bar), res_name))
814 			goto err_out;
815 	}
816 	else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM) {
817 		if (!request_mem_region(pci_resource_start(pdev, bar),
818 				        pci_resource_len(pdev, bar), res_name))
819 			goto err_out;
820 	}
821 
822 	return 0;
823 
824 err_out:
825 	printk (KERN_WARNING "PCI: Unable to reserve %s region #%d:%llx@%llx "
826 		"for device %s\n",
827 		pci_resource_flags(pdev, bar) & IORESOURCE_IO ? "I/O" : "mem",
828 		bar + 1, /* PCI BAR # */
829 		(unsigned long long)pci_resource_len(pdev, bar),
830 		(unsigned long long)pci_resource_start(pdev, bar),
831 		pci_name(pdev));
832 	return -EBUSY;
833 }
834 
835 
836 /**
837  *	pci_release_regions - Release reserved PCI I/O and memory resources
838  *	@pdev: PCI device whose resources were previously reserved by pci_request_regions
839  *
840  *	Releases all PCI I/O and memory resources previously reserved by a
841  *	successful call to pci_request_regions.  Call this function only
842  *	after all use of the PCI regions has ceased.
843  */
844 
845 void pci_release_regions(struct pci_dev *pdev)
846 {
847 	int i;
848 
849 	for (i = 0; i < 6; i++)
850 		pci_release_region(pdev, i);
851 }
852 
853 /**
854  *	pci_request_regions - Reserved PCI I/O and memory resources
855  *	@pdev: PCI device whose resources are to be reserved
856  *	@res_name: Name to be associated with resource.
857  *
858  *	Mark all PCI regions associated with PCI device @pdev as
859  *	being reserved by owner @res_name.  Do not access any
860  *	address inside the PCI regions unless this call returns
861  *	successfully.
862  *
863  *	Returns 0 on success, or %EBUSY on error.  A warning
864  *	message is also printed on failure.
865  */
866 int pci_request_regions(struct pci_dev *pdev, const char *res_name)
867 {
868 	int i;
869 
870 	for (i = 0; i < 6; i++)
871 		if(pci_request_region(pdev, i, res_name))
872 			goto err_out;
873 	return 0;
874 
875 err_out:
876 	while(--i >= 0)
877 		pci_release_region(pdev, i);
878 
879 	return -EBUSY;
880 }
881 
882 /**
883  * pci_set_master - enables bus-mastering for device dev
884  * @dev: the PCI device to enable
885  *
886  * Enables bus-mastering on the device and calls pcibios_set_master()
887  * to do the needed arch specific settings.
888  */
889 void
890 pci_set_master(struct pci_dev *dev)
891 {
892 	u16 cmd;
893 
894 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
895 	if (! (cmd & PCI_COMMAND_MASTER)) {
896 		pr_debug("PCI: Enabling bus mastering for device %s\n", pci_name(dev));
897 		cmd |= PCI_COMMAND_MASTER;
898 		pci_write_config_word(dev, PCI_COMMAND, cmd);
899 	}
900 	dev->is_busmaster = 1;
901 	pcibios_set_master(dev);
902 }
903 
904 #ifdef PCI_DISABLE_MWI
905 int pci_set_mwi(struct pci_dev *dev)
906 {
907 	return 0;
908 }
909 
910 void pci_clear_mwi(struct pci_dev *dev)
911 {
912 }
913 
914 #else
915 
916 #ifndef PCI_CACHE_LINE_BYTES
917 #define PCI_CACHE_LINE_BYTES L1_CACHE_BYTES
918 #endif
919 
920 /* This can be overridden by arch code. */
921 /* Don't forget this is measured in 32-bit words, not bytes */
922 u8 pci_cache_line_size = PCI_CACHE_LINE_BYTES / 4;
923 
924 /**
925  * pci_set_cacheline_size - ensure the CACHE_LINE_SIZE register is programmed
926  * @dev: the PCI device for which MWI is to be enabled
927  *
928  * Helper function for pci_set_mwi.
929  * Originally copied from drivers/net/acenic.c.
930  * Copyright 1998-2001 by Jes Sorensen, <jes@trained-monkey.org>.
931  *
932  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
933  */
934 static int
935 pci_set_cacheline_size(struct pci_dev *dev)
936 {
937 	u8 cacheline_size;
938 
939 	if (!pci_cache_line_size)
940 		return -EINVAL;		/* The system doesn't support MWI. */
941 
942 	/* Validate current setting: the PCI_CACHE_LINE_SIZE must be
943 	   equal to or multiple of the right value. */
944 	pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
945 	if (cacheline_size >= pci_cache_line_size &&
946 	    (cacheline_size % pci_cache_line_size) == 0)
947 		return 0;
948 
949 	/* Write the correct value. */
950 	pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, pci_cache_line_size);
951 	/* Read it back. */
952 	pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
953 	if (cacheline_size == pci_cache_line_size)
954 		return 0;
955 
956 	printk(KERN_DEBUG "PCI: cache line size of %d is not supported "
957 	       "by device %s\n", pci_cache_line_size << 2, pci_name(dev));
958 
959 	return -EINVAL;
960 }
961 
962 /**
963  * pci_set_mwi - enables memory-write-invalidate PCI transaction
964  * @dev: the PCI device for which MWI is enabled
965  *
966  * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND,
967  * and then calls @pcibios_set_mwi to do the needed arch specific
968  * operations or a generic mwi-prep function.
969  *
970  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
971  */
972 int
973 pci_set_mwi(struct pci_dev *dev)
974 {
975 	int rc;
976 	u16 cmd;
977 
978 	rc = pci_set_cacheline_size(dev);
979 	if (rc)
980 		return rc;
981 
982 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
983 	if (! (cmd & PCI_COMMAND_INVALIDATE)) {
984 		pr_debug("PCI: Enabling Mem-Wr-Inval for device %s\n", pci_name(dev));
985 		cmd |= PCI_COMMAND_INVALIDATE;
986 		pci_write_config_word(dev, PCI_COMMAND, cmd);
987 	}
988 
989 	return 0;
990 }
991 
992 /**
993  * pci_clear_mwi - disables Memory-Write-Invalidate for device dev
994  * @dev: the PCI device to disable
995  *
996  * Disables PCI Memory-Write-Invalidate transaction on the device
997  */
998 void
999 pci_clear_mwi(struct pci_dev *dev)
1000 {
1001 	u16 cmd;
1002 
1003 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
1004 	if (cmd & PCI_COMMAND_INVALIDATE) {
1005 		cmd &= ~PCI_COMMAND_INVALIDATE;
1006 		pci_write_config_word(dev, PCI_COMMAND, cmd);
1007 	}
1008 }
1009 #endif /* ! PCI_DISABLE_MWI */
1010 
1011 /**
1012  * pci_intx - enables/disables PCI INTx for device dev
1013  * @pdev: the PCI device to operate on
1014  * @enable: boolean: whether to enable or disable PCI INTx
1015  *
1016  * Enables/disables PCI INTx for device dev
1017  */
1018 void
1019 pci_intx(struct pci_dev *pdev, int enable)
1020 {
1021 	u16 pci_command, new;
1022 
1023 	pci_read_config_word(pdev, PCI_COMMAND, &pci_command);
1024 
1025 	if (enable) {
1026 		new = pci_command & ~PCI_COMMAND_INTX_DISABLE;
1027 	} else {
1028 		new = pci_command | PCI_COMMAND_INTX_DISABLE;
1029 	}
1030 
1031 	if (new != pci_command) {
1032 		pci_write_config_word(pdev, PCI_COMMAND, new);
1033 	}
1034 }
1035 
1036 #ifndef HAVE_ARCH_PCI_SET_DMA_MASK
1037 /*
1038  * These can be overridden by arch-specific implementations
1039  */
1040 int
1041 pci_set_dma_mask(struct pci_dev *dev, u64 mask)
1042 {
1043 	if (!pci_dma_supported(dev, mask))
1044 		return -EIO;
1045 
1046 	dev->dma_mask = mask;
1047 
1048 	return 0;
1049 }
1050 
1051 int
1052 pci_set_consistent_dma_mask(struct pci_dev *dev, u64 mask)
1053 {
1054 	if (!pci_dma_supported(dev, mask))
1055 		return -EIO;
1056 
1057 	dev->dev.coherent_dma_mask = mask;
1058 
1059 	return 0;
1060 }
1061 #endif
1062 
1063 static int __devinit pci_init(void)
1064 {
1065 	struct pci_dev *dev = NULL;
1066 
1067 	while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
1068 		pci_fixup_device(pci_fixup_final, dev);
1069 	}
1070 	return 0;
1071 }
1072 
1073 static int __devinit pci_setup(char *str)
1074 {
1075 	while (str) {
1076 		char *k = strchr(str, ',');
1077 		if (k)
1078 			*k++ = 0;
1079 		if (*str && (str = pcibios_setup(str)) && *str) {
1080 			if (!strcmp(str, "nomsi")) {
1081 				pci_no_msi();
1082 			} else {
1083 				printk(KERN_ERR "PCI: Unknown option `%s'\n",
1084 						str);
1085 			}
1086 		}
1087 		str = k;
1088 	}
1089 	return 0;
1090 }
1091 early_param("pci", pci_setup);
1092 
1093 device_initcall(pci_init);
1094 
1095 #if defined(CONFIG_ISA) || defined(CONFIG_EISA)
1096 /* FIXME: Some boxes have multiple ISA bridges! */
1097 struct pci_dev *isa_bridge;
1098 EXPORT_SYMBOL(isa_bridge);
1099 #endif
1100 
1101 EXPORT_SYMBOL_GPL(pci_restore_bars);
1102 EXPORT_SYMBOL(pci_enable_device_bars);
1103 EXPORT_SYMBOL(pci_enable_device);
1104 EXPORT_SYMBOL(pci_disable_device);
1105 EXPORT_SYMBOL(pci_find_capability);
1106 EXPORT_SYMBOL(pci_bus_find_capability);
1107 EXPORT_SYMBOL(pci_release_regions);
1108 EXPORT_SYMBOL(pci_request_regions);
1109 EXPORT_SYMBOL(pci_release_region);
1110 EXPORT_SYMBOL(pci_request_region);
1111 EXPORT_SYMBOL(pci_set_master);
1112 EXPORT_SYMBOL(pci_set_mwi);
1113 EXPORT_SYMBOL(pci_clear_mwi);
1114 EXPORT_SYMBOL_GPL(pci_intx);
1115 EXPORT_SYMBOL(pci_set_dma_mask);
1116 EXPORT_SYMBOL(pci_set_consistent_dma_mask);
1117 EXPORT_SYMBOL(pci_assign_resource);
1118 EXPORT_SYMBOL(pci_find_parent_resource);
1119 
1120 EXPORT_SYMBOL(pci_set_power_state);
1121 EXPORT_SYMBOL(pci_save_state);
1122 EXPORT_SYMBOL(pci_restore_state);
1123 EXPORT_SYMBOL(pci_enable_wake);
1124 
1125 /* Quirk info */
1126 
1127 EXPORT_SYMBOL(isa_dma_bridge_buggy);
1128 EXPORT_SYMBOL(pci_pci_problems);
1129