PCI: kernel-doc fix
[linux-2.6/mini2440.git] / drivers / pci / pci.c
blob7bd8a725bea21d6fb9ea960261e68082da3e1066
1 /*
2 * $Id: pci.c,v 1.91 1999/01/21 13:34:01 davem Exp $
4 * PCI Bus Services, see include/linux/pci.h for further explanation.
6 * Copyright 1993 -- 1997 Drew Eckhardt, Frederic Potter,
7 * David Mosberger-Tang
9 * Copyright 1997 -- 2000 Martin Mares <mj@ucw.cz>
12 #include <linux/kernel.h>
13 #include <linux/delay.h>
14 #include <linux/init.h>
15 #include <linux/pci.h>
16 #include <linux/pm.h>
17 #include <linux/module.h>
18 #include <linux/spinlock.h>
19 #include <linux/string.h>
20 #include <asm/dma.h> /* isa_dma_bridge_buggy */
21 #include "pci.h"
23 unsigned int pci_pm_d3_delay = 10;
25 #define DEFAULT_CARDBUS_IO_SIZE (256)
26 #define DEFAULT_CARDBUS_MEM_SIZE (64*1024*1024)
27 /* pci=cbmemsize=nnM,cbiosize=nn can override this */
28 unsigned long pci_cardbus_io_size = DEFAULT_CARDBUS_IO_SIZE;
29 unsigned long pci_cardbus_mem_size = DEFAULT_CARDBUS_MEM_SIZE;
31 /**
32 * pci_bus_max_busnr - returns maximum PCI bus number of given bus' children
33 * @bus: pointer to PCI bus structure to search
35 * Given a PCI bus, returns the highest PCI bus number present in the set
36 * including the given PCI bus and its list of child PCI buses.
38 unsigned char __devinit
39 pci_bus_max_busnr(struct pci_bus* bus)
41 struct list_head *tmp;
42 unsigned char max, n;
44 max = bus->subordinate;
45 list_for_each(tmp, &bus->children) {
46 n = pci_bus_max_busnr(pci_bus_b(tmp));
47 if(n > max)
48 max = n;
50 return max;
52 EXPORT_SYMBOL_GPL(pci_bus_max_busnr);
54 #if 0
55 /**
56 * pci_max_busnr - returns maximum PCI bus number
58 * Returns the highest PCI bus number present in the system global list of
59 * PCI buses.
61 unsigned char __devinit
62 pci_max_busnr(void)
64 struct pci_bus *bus = NULL;
65 unsigned char max, n;
67 max = 0;
68 while ((bus = pci_find_next_bus(bus)) != NULL) {
69 n = pci_bus_max_busnr(bus);
70 if(n > max)
71 max = n;
73 return max;
76 #endif /* 0 */
78 #define PCI_FIND_CAP_TTL 48
80 static int __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn,
81 u8 pos, int cap, int *ttl)
83 u8 id;
85 while ((*ttl)--) {
86 pci_bus_read_config_byte(bus, devfn, pos, &pos);
87 if (pos < 0x40)
88 break;
89 pos &= ~3;
90 pci_bus_read_config_byte(bus, devfn, pos + PCI_CAP_LIST_ID,
91 &id);
92 if (id == 0xff)
93 break;
94 if (id == cap)
95 return pos;
96 pos += PCI_CAP_LIST_NEXT;
98 return 0;
101 static int __pci_find_next_cap(struct pci_bus *bus, unsigned int devfn,
102 u8 pos, int cap)
104 int ttl = PCI_FIND_CAP_TTL;
106 return __pci_find_next_cap_ttl(bus, devfn, pos, cap, &ttl);
109 int pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap)
111 return __pci_find_next_cap(dev->bus, dev->devfn,
112 pos + PCI_CAP_LIST_NEXT, cap);
114 EXPORT_SYMBOL_GPL(pci_find_next_capability);
116 static int __pci_bus_find_cap_start(struct pci_bus *bus,
117 unsigned int devfn, u8 hdr_type)
119 u16 status;
121 pci_bus_read_config_word(bus, devfn, PCI_STATUS, &status);
122 if (!(status & PCI_STATUS_CAP_LIST))
123 return 0;
125 switch (hdr_type) {
126 case PCI_HEADER_TYPE_NORMAL:
127 case PCI_HEADER_TYPE_BRIDGE:
128 return PCI_CAPABILITY_LIST;
129 case PCI_HEADER_TYPE_CARDBUS:
130 return PCI_CB_CAPABILITY_LIST;
131 default:
132 return 0;
135 return 0;
139 * pci_find_capability - query for devices' capabilities
140 * @dev: PCI device to query
141 * @cap: capability code
143 * Tell if a device supports a given PCI capability.
144 * Returns the address of the requested capability structure within the
145 * device's PCI configuration space or 0 in case the device does not
146 * support it. Possible values for @cap:
148 * %PCI_CAP_ID_PM Power Management
149 * %PCI_CAP_ID_AGP Accelerated Graphics Port
150 * %PCI_CAP_ID_VPD Vital Product Data
151 * %PCI_CAP_ID_SLOTID Slot Identification
152 * %PCI_CAP_ID_MSI Message Signalled Interrupts
153 * %PCI_CAP_ID_CHSWP CompactPCI HotSwap
154 * %PCI_CAP_ID_PCIX PCI-X
155 * %PCI_CAP_ID_EXP PCI Express
157 int pci_find_capability(struct pci_dev *dev, int cap)
159 int pos;
161 pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);
162 if (pos)
163 pos = __pci_find_next_cap(dev->bus, dev->devfn, pos, cap);
165 return pos;
169 * pci_bus_find_capability - query for devices' capabilities
170 * @bus: the PCI bus to query
171 * @devfn: PCI device to query
172 * @cap: capability code
174 * Like pci_find_capability() but works for pci devices that do not have a
175 * pci_dev structure set up yet.
177 * Returns the address of the requested capability structure within the
178 * device's PCI configuration space or 0 in case the device does not
179 * support it.
181 int pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap)
183 int pos;
184 u8 hdr_type;
186 pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &hdr_type);
188 pos = __pci_bus_find_cap_start(bus, devfn, hdr_type & 0x7f);
189 if (pos)
190 pos = __pci_find_next_cap(bus, devfn, pos, cap);
192 return pos;
196 * pci_find_ext_capability - Find an extended capability
197 * @dev: PCI device to query
198 * @cap: capability code
200 * Returns the address of the requested extended capability structure
201 * within the device's PCI configuration space or 0 if the device does
202 * not support it. Possible values for @cap:
204 * %PCI_EXT_CAP_ID_ERR Advanced Error Reporting
205 * %PCI_EXT_CAP_ID_VC Virtual Channel
206 * %PCI_EXT_CAP_ID_DSN Device Serial Number
207 * %PCI_EXT_CAP_ID_PWR Power Budgeting
209 int pci_find_ext_capability(struct pci_dev *dev, int cap)
211 u32 header;
212 int ttl = 480; /* 3840 bytes, minimum 8 bytes per capability */
213 int pos = 0x100;
215 if (dev->cfg_size <= 256)
216 return 0;
218 if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
219 return 0;
222 * If we have no capabilities, this is indicated by cap ID,
223 * cap version and next pointer all being 0.
225 if (header == 0)
226 return 0;
228 while (ttl-- > 0) {
229 if (PCI_EXT_CAP_ID(header) == cap)
230 return pos;
232 pos = PCI_EXT_CAP_NEXT(header);
233 if (pos < 0x100)
234 break;
236 if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
237 break;
240 return 0;
242 EXPORT_SYMBOL_GPL(pci_find_ext_capability);
244 static int __pci_find_next_ht_cap(struct pci_dev *dev, int pos, int ht_cap)
246 int rc, ttl = PCI_FIND_CAP_TTL;
247 u8 cap, mask;
249 if (ht_cap == HT_CAPTYPE_SLAVE || ht_cap == HT_CAPTYPE_HOST)
250 mask = HT_3BIT_CAP_MASK;
251 else
252 mask = HT_5BIT_CAP_MASK;
254 pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn, pos,
255 PCI_CAP_ID_HT, &ttl);
256 while (pos) {
257 rc = pci_read_config_byte(dev, pos + 3, &cap);
258 if (rc != PCIBIOS_SUCCESSFUL)
259 return 0;
261 if ((cap & mask) == ht_cap)
262 return pos;
264 pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn,
265 pos + PCI_CAP_LIST_NEXT,
266 PCI_CAP_ID_HT, &ttl);
269 return 0;
272 * pci_find_next_ht_capability - query a device's Hypertransport capabilities
273 * @dev: PCI device to query
274 * @pos: Position from which to continue searching
275 * @ht_cap: Hypertransport capability code
277 * To be used in conjunction with pci_find_ht_capability() to search for
278 * all capabilities matching @ht_cap. @pos should always be a value returned
279 * from pci_find_ht_capability().
281 * NB. To be 100% safe against broken PCI devices, the caller should take
282 * steps to avoid an infinite loop.
284 int pci_find_next_ht_capability(struct pci_dev *dev, int pos, int ht_cap)
286 return __pci_find_next_ht_cap(dev, pos + PCI_CAP_LIST_NEXT, ht_cap);
288 EXPORT_SYMBOL_GPL(pci_find_next_ht_capability);
291 * pci_find_ht_capability - query a device's Hypertransport capabilities
292 * @dev: PCI device to query
293 * @ht_cap: Hypertransport capability code
295 * Tell if a device supports a given Hypertransport capability.
296 * Returns an address within the device's PCI configuration space
297 * or 0 in case the device does not support the request capability.
298 * The address points to the PCI capability, of type PCI_CAP_ID_HT,
299 * which has a Hypertransport capability matching @ht_cap.
301 int pci_find_ht_capability(struct pci_dev *dev, int ht_cap)
303 int pos;
305 pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);
306 if (pos)
307 pos = __pci_find_next_ht_cap(dev, pos, ht_cap);
309 return pos;
311 EXPORT_SYMBOL_GPL(pci_find_ht_capability);
314 * pci_find_parent_resource - return resource region of parent bus of given region
315 * @dev: PCI device structure contains resources to be searched
316 * @res: child resource record for which parent is sought
318 * For given resource region of given device, return the resource
319 * region of parent bus the given region is contained in or where
320 * it should be allocated from.
322 struct resource *
323 pci_find_parent_resource(const struct pci_dev *dev, struct resource *res)
325 const struct pci_bus *bus = dev->bus;
326 int i;
327 struct resource *best = NULL;
329 for(i = 0; i < PCI_BUS_NUM_RESOURCES; i++) {
330 struct resource *r = bus->resource[i];
331 if (!r)
332 continue;
333 if (res->start && !(res->start >= r->start && res->end <= r->end))
334 continue; /* Not contained */
335 if ((res->flags ^ r->flags) & (IORESOURCE_IO | IORESOURCE_MEM))
336 continue; /* Wrong type */
337 if (!((res->flags ^ r->flags) & IORESOURCE_PREFETCH))
338 return r; /* Exact match */
339 if ((res->flags & IORESOURCE_PREFETCH) && !(r->flags & IORESOURCE_PREFETCH))
340 best = r; /* Approximating prefetchable by non-prefetchable */
342 return best;
346 * pci_restore_bars - restore a devices BAR values (e.g. after wake-up)
347 * @dev: PCI device to have its BARs restored
349 * Restore the BAR values for a given device, so as to make it
350 * accessible by its driver.
352 void
353 pci_restore_bars(struct pci_dev *dev)
355 int i, numres;
357 switch (dev->hdr_type) {
358 case PCI_HEADER_TYPE_NORMAL:
359 numres = 6;
360 break;
361 case PCI_HEADER_TYPE_BRIDGE:
362 numres = 2;
363 break;
364 case PCI_HEADER_TYPE_CARDBUS:
365 numres = 1;
366 break;
367 default:
368 /* Should never get here, but just in case... */
369 return;
372 for (i = 0; i < numres; i ++)
373 pci_update_resource(dev, &dev->resource[i], i);
376 int (*platform_pci_set_power_state)(struct pci_dev *dev, pci_power_t t);
379 * pci_set_power_state - Set the power state of a PCI device
380 * @dev: PCI device to be suspended
381 * @state: PCI power state (D0, D1, D2, D3hot, D3cold) we're entering
383 * Transition a device to a new power state, using the Power Management
384 * Capabilities in the device's config space.
386 * RETURN VALUE:
387 * -EINVAL if trying to enter a lower state than we're already in.
388 * 0 if we're already in the requested state.
389 * -EIO if device does not support PCI PM.
390 * 0 if we can successfully change the power state.
393 pci_set_power_state(struct pci_dev *dev, pci_power_t state)
395 int pm, need_restore = 0;
396 u16 pmcsr, pmc;
398 /* bound the state we're entering */
399 if (state > PCI_D3hot)
400 state = PCI_D3hot;
403 * If the device or the parent bridge can't support PCI PM, ignore
404 * the request if we're doing anything besides putting it into D0
405 * (which would only happen on boot).
407 if ((state == PCI_D1 || state == PCI_D2) && pci_no_d1d2(dev))
408 return 0;
410 /* Validate current state:
411 * Can enter D0 from any state, but if we can only go deeper
412 * to sleep if we're already in a low power state
414 if (state != PCI_D0 && dev->current_state > state) {
415 printk(KERN_ERR "%s(): %s: state=%d, current state=%d\n",
416 __FUNCTION__, pci_name(dev), state, dev->current_state);
417 return -EINVAL;
418 } else if (dev->current_state == state)
419 return 0; /* we're already there */
422 /* find PCI PM capability in list */
423 pm = pci_find_capability(dev, PCI_CAP_ID_PM);
425 /* abort if the device doesn't support PM capabilities */
426 if (!pm)
427 return -EIO;
429 pci_read_config_word(dev,pm + PCI_PM_PMC,&pmc);
430 if ((pmc & PCI_PM_CAP_VER_MASK) > 3) {
431 printk(KERN_DEBUG
432 "PCI: %s has unsupported PM cap regs version (%u)\n",
433 pci_name(dev), pmc & PCI_PM_CAP_VER_MASK);
434 return -EIO;
437 /* check if this device supports the desired state */
438 if (state == PCI_D1 && !(pmc & PCI_PM_CAP_D1))
439 return -EIO;
440 else if (state == PCI_D2 && !(pmc & PCI_PM_CAP_D2))
441 return -EIO;
443 pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr);
445 /* If we're (effectively) in D3, force entire word to 0.
446 * This doesn't affect PME_Status, disables PME_En, and
447 * sets PowerState to 0.
449 switch (dev->current_state) {
450 case PCI_D0:
451 case PCI_D1:
452 case PCI_D2:
453 pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
454 pmcsr |= state;
455 break;
456 case PCI_UNKNOWN: /* Boot-up */
457 if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot
458 && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))
459 need_restore = 1;
460 /* Fall-through: force to D0 */
461 default:
462 pmcsr = 0;
463 break;
466 /* enter specified state */
467 pci_write_config_word(dev, pm + PCI_PM_CTRL, pmcsr);
469 /* Mandatory power management transition delays */
470 /* see PCI PM 1.1 5.6.1 table 18 */
471 if (state == PCI_D3hot || dev->current_state == PCI_D3hot)
472 msleep(pci_pm_d3_delay);
473 else if (state == PCI_D2 || dev->current_state == PCI_D2)
474 udelay(200);
477 * Give firmware a chance to be called, such as ACPI _PRx, _PSx
478 * Firmware method after native method ?
480 if (platform_pci_set_power_state)
481 platform_pci_set_power_state(dev, state);
483 dev->current_state = state;
485 /* According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT
486 * INTERFACE SPECIFICATION, REV. 1.2", a device transitioning
487 * from D3hot to D0 _may_ perform an internal reset, thereby
488 * going to "D0 Uninitialized" rather than "D0 Initialized".
489 * For example, at least some versions of the 3c905B and the
490 * 3c556B exhibit this behaviour.
492 * At least some laptop BIOSen (e.g. the Thinkpad T21) leave
493 * devices in a D3hot state at boot. Consequently, we need to
494 * restore at least the BARs so that the device will be
495 * accessible to its driver.
497 if (need_restore)
498 pci_restore_bars(dev);
500 return 0;
503 int (*platform_pci_choose_state)(struct pci_dev *dev, pm_message_t state);
506 * pci_choose_state - Choose the power state of a PCI device
507 * @dev: PCI device to be suspended
508 * @state: target sleep state for the whole system. This is the value
509 * that is passed to suspend() function.
511 * Returns PCI power state suitable for given device and given system
512 * message.
515 pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state)
517 int ret;
519 if (!pci_find_capability(dev, PCI_CAP_ID_PM))
520 return PCI_D0;
522 if (platform_pci_choose_state) {
523 ret = platform_pci_choose_state(dev, state);
524 if (ret >= 0)
525 state.event = ret;
528 switch (state.event) {
529 case PM_EVENT_ON:
530 return PCI_D0;
531 case PM_EVENT_FREEZE:
532 case PM_EVENT_PRETHAW:
533 /* REVISIT both freeze and pre-thaw "should" use D0 */
534 case PM_EVENT_SUSPEND:
535 return PCI_D3hot;
536 default:
537 printk("Unrecognized suspend event %d\n", state.event);
538 BUG();
540 return PCI_D0;
543 EXPORT_SYMBOL(pci_choose_state);
545 static int pci_save_pcie_state(struct pci_dev *dev)
547 int pos, i = 0;
548 struct pci_cap_saved_state *save_state;
549 u16 *cap;
551 pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
552 if (pos <= 0)
553 return 0;
555 save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
556 if (!save_state)
557 save_state = kzalloc(sizeof(*save_state) + sizeof(u16) * 4, GFP_KERNEL);
558 if (!save_state) {
559 dev_err(&dev->dev, "Out of memory in pci_save_pcie_state\n");
560 return -ENOMEM;
562 cap = (u16 *)&save_state->data[0];
564 pci_read_config_word(dev, pos + PCI_EXP_DEVCTL, &cap[i++]);
565 pci_read_config_word(dev, pos + PCI_EXP_LNKCTL, &cap[i++]);
566 pci_read_config_word(dev, pos + PCI_EXP_SLTCTL, &cap[i++]);
567 pci_read_config_word(dev, pos + PCI_EXP_RTCTL, &cap[i++]);
568 pci_add_saved_cap(dev, save_state);
569 return 0;
572 static void pci_restore_pcie_state(struct pci_dev *dev)
574 int i = 0, pos;
575 struct pci_cap_saved_state *save_state;
576 u16 *cap;
578 save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
579 pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
580 if (!save_state || pos <= 0)
581 return;
582 cap = (u16 *)&save_state->data[0];
584 pci_write_config_word(dev, pos + PCI_EXP_DEVCTL, cap[i++]);
585 pci_write_config_word(dev, pos + PCI_EXP_LNKCTL, cap[i++]);
586 pci_write_config_word(dev, pos + PCI_EXP_SLTCTL, cap[i++]);
587 pci_write_config_word(dev, pos + PCI_EXP_RTCTL, cap[i++]);
591 static int pci_save_pcix_state(struct pci_dev *dev)
593 int pos, i = 0;
594 struct pci_cap_saved_state *save_state;
595 u16 *cap;
597 pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
598 if (pos <= 0)
599 return 0;
601 save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
602 if (!save_state)
603 save_state = kzalloc(sizeof(*save_state) + sizeof(u16), GFP_KERNEL);
604 if (!save_state) {
605 dev_err(&dev->dev, "Out of memory in pci_save_pcie_state\n");
606 return -ENOMEM;
608 cap = (u16 *)&save_state->data[0];
610 pci_read_config_word(dev, pos + PCI_X_CMD, &cap[i++]);
611 pci_add_saved_cap(dev, save_state);
612 return 0;
615 static void pci_restore_pcix_state(struct pci_dev *dev)
617 int i = 0, pos;
618 struct pci_cap_saved_state *save_state;
619 u16 *cap;
621 save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX);
622 pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
623 if (!save_state || pos <= 0)
624 return;
625 cap = (u16 *)&save_state->data[0];
627 pci_write_config_word(dev, pos + PCI_X_CMD, cap[i++]);
632 * pci_save_state - save the PCI configuration space of a device before suspending
633 * @dev: - PCI device that we're dealing with
636 pci_save_state(struct pci_dev *dev)
638 int i;
639 /* XXX: 100% dword access ok here? */
640 for (i = 0; i < 16; i++)
641 pci_read_config_dword(dev, i * 4,&dev->saved_config_space[i]);
642 if ((i = pci_save_pcie_state(dev)) != 0)
643 return i;
644 if ((i = pci_save_pcix_state(dev)) != 0)
645 return i;
646 return 0;
649 /**
650 * pci_restore_state - Restore the saved state of a PCI device
651 * @dev: - PCI device that we're dealing with
653 int
654 pci_restore_state(struct pci_dev *dev)
656 int i;
657 int val;
659 /* PCI Express register must be restored first */
660 pci_restore_pcie_state(dev);
663 * The Base Address register should be programmed before the command
664 * register(s)
666 for (i = 15; i >= 0; i--) {
667 pci_read_config_dword(dev, i * 4, &val);
668 if (val != dev->saved_config_space[i]) {
669 printk(KERN_DEBUG "PM: Writing back config space on "
670 "device %s at offset %x (was %x, writing %x)\n",
671 pci_name(dev), i,
672 val, (int)dev->saved_config_space[i]);
673 pci_write_config_dword(dev,i * 4,
674 dev->saved_config_space[i]);
677 pci_restore_pcix_state(dev);
678 pci_restore_msi_state(dev);
680 return 0;
683 static int do_pci_enable_device(struct pci_dev *dev, int bars)
685 int err;
687 err = pci_set_power_state(dev, PCI_D0);
688 if (err < 0 && err != -EIO)
689 return err;
690 err = pcibios_enable_device(dev, bars);
691 if (err < 0)
692 return err;
693 pci_fixup_device(pci_fixup_enable, dev);
695 return 0;
699 * __pci_reenable_device - Resume abandoned device
700 * @dev: PCI device to be resumed
702 * Note this function is a backend of pci_default_resume and is not supposed
703 * to be called by normal code, write proper resume handler and use it instead.
706 __pci_reenable_device(struct pci_dev *dev)
708 if (atomic_read(&dev->enable_cnt))
709 return do_pci_enable_device(dev, (1 << PCI_NUM_RESOURCES) - 1);
710 return 0;
714 * pci_enable_device_bars - Initialize some of a device for use
715 * @dev: PCI device to be initialized
716 * @bars: bitmask of BAR's that must be configured
718 * Initialize device before it's used by a driver. Ask low-level code
719 * to enable selected I/O and memory resources. Wake up the device if it
720 * was suspended. Beware, this function can fail.
723 pci_enable_device_bars(struct pci_dev *dev, int bars)
725 int err;
727 if (atomic_add_return(1, &dev->enable_cnt) > 1)
728 return 0; /* already enabled */
730 err = do_pci_enable_device(dev, bars);
731 if (err < 0)
732 atomic_dec(&dev->enable_cnt);
733 return err;
737 * pci_enable_device - Initialize device before it's used by a driver.
738 * @dev: PCI device to be initialized
740 * Initialize device before it's used by a driver. Ask low-level code
741 * to enable I/O and memory. Wake up the device if it was suspended.
742 * Beware, this function can fail.
744 * Note we don't actually enable the device many times if we call
745 * this function repeatedly (we just increment the count).
747 int pci_enable_device(struct pci_dev *dev)
749 return pci_enable_device_bars(dev, (1 << PCI_NUM_RESOURCES) - 1);
753 * Managed PCI resources. This manages device on/off, intx/msi/msix
754 * on/off and BAR regions. pci_dev itself records msi/msix status, so
755 * there's no need to track it separately. pci_devres is initialized
756 * when a device is enabled using managed PCI device enable interface.
758 struct pci_devres {
759 unsigned int enabled:1;
760 unsigned int pinned:1;
761 unsigned int orig_intx:1;
762 unsigned int restore_intx:1;
763 u32 region_mask;
766 static void pcim_release(struct device *gendev, void *res)
768 struct pci_dev *dev = container_of(gendev, struct pci_dev, dev);
769 struct pci_devres *this = res;
770 int i;
772 if (dev->msi_enabled)
773 pci_disable_msi(dev);
774 if (dev->msix_enabled)
775 pci_disable_msix(dev);
777 for (i = 0; i < DEVICE_COUNT_RESOURCE; i++)
778 if (this->region_mask & (1 << i))
779 pci_release_region(dev, i);
781 if (this->restore_intx)
782 pci_intx(dev, this->orig_intx);
784 if (this->enabled && !this->pinned)
785 pci_disable_device(dev);
788 static struct pci_devres * get_pci_dr(struct pci_dev *pdev)
790 struct pci_devres *dr, *new_dr;
792 dr = devres_find(&pdev->dev, pcim_release, NULL, NULL);
793 if (dr)
794 return dr;
796 new_dr = devres_alloc(pcim_release, sizeof(*new_dr), GFP_KERNEL);
797 if (!new_dr)
798 return NULL;
799 return devres_get(&pdev->dev, new_dr, NULL, NULL);
802 static struct pci_devres * find_pci_dr(struct pci_dev *pdev)
804 if (pci_is_managed(pdev))
805 return devres_find(&pdev->dev, pcim_release, NULL, NULL);
806 return NULL;
810 * pcim_enable_device - Managed pci_enable_device()
811 * @pdev: PCI device to be initialized
813 * Managed pci_enable_device().
815 int pcim_enable_device(struct pci_dev *pdev)
817 struct pci_devres *dr;
818 int rc;
820 dr = get_pci_dr(pdev);
821 if (unlikely(!dr))
822 return -ENOMEM;
823 WARN_ON(!!dr->enabled);
825 rc = pci_enable_device(pdev);
826 if (!rc) {
827 pdev->is_managed = 1;
828 dr->enabled = 1;
830 return rc;
834 * pcim_pin_device - Pin managed PCI device
835 * @pdev: PCI device to pin
837 * Pin managed PCI device @pdev. Pinned device won't be disabled on
838 * driver detach. @pdev must have been enabled with
839 * pcim_enable_device().
841 void pcim_pin_device(struct pci_dev *pdev)
843 struct pci_devres *dr;
845 dr = find_pci_dr(pdev);
846 WARN_ON(!dr || !dr->enabled);
847 if (dr)
848 dr->pinned = 1;
852 * pcibios_disable_device - disable arch specific PCI resources for device dev
853 * @dev: the PCI device to disable
855 * Disables architecture specific PCI resources for the device. This
856 * is the default implementation. Architecture implementations can
857 * override this.
859 void __attribute__ ((weak)) pcibios_disable_device (struct pci_dev *dev) {}
862 * pci_disable_device - Disable PCI device after use
863 * @dev: PCI device to be disabled
865 * Signal to the system that the PCI device is not in use by the system
866 * anymore. This only involves disabling PCI bus-mastering, if active.
868 * Note we don't actually disable the device until all callers of
869 * pci_device_enable() have called pci_device_disable().
871 void
872 pci_disable_device(struct pci_dev *dev)
874 struct pci_devres *dr;
875 u16 pci_command;
877 dr = find_pci_dr(dev);
878 if (dr)
879 dr->enabled = 0;
881 if (atomic_sub_return(1, &dev->enable_cnt) != 0)
882 return;
884 pci_read_config_word(dev, PCI_COMMAND, &pci_command);
885 if (pci_command & PCI_COMMAND_MASTER) {
886 pci_command &= ~PCI_COMMAND_MASTER;
887 pci_write_config_word(dev, PCI_COMMAND, pci_command);
889 dev->is_busmaster = 0;
891 pcibios_disable_device(dev);
895 * pcibios_set_pcie_reset_state - set reset state for device dev
896 * @dev: the PCI-E device reset
897 * @state: Reset state to enter into
900 * Sets the PCI-E reset state for the device. This is the default
901 * implementation. Architecture implementations can override this.
903 int __attribute__ ((weak)) pcibios_set_pcie_reset_state(struct pci_dev *dev,
904 enum pcie_reset_state state)
906 return -EINVAL;
910 * pci_set_pcie_reset_state - set reset state for device dev
911 * @dev: the PCI-E device reset
912 * @state: Reset state to enter into
915 * Sets the PCI reset state for the device.
917 int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state)
919 return pcibios_set_pcie_reset_state(dev, state);
923 * pci_enable_wake - enable PCI device as wakeup event source
924 * @dev: PCI device affected
925 * @state: PCI state from which device will issue wakeup events
926 * @enable: True to enable event generation; false to disable
928 * This enables the device as a wakeup event source, or disables it.
929 * When such events involves platform-specific hooks, those hooks are
930 * called automatically by this routine.
932 * Devices with legacy power management (no standard PCI PM capabilities)
933 * always require such platform hooks. Depending on the platform, devices
934 * supporting the standard PCI PME# signal may require such platform hooks;
935 * they always update bits in config space to allow PME# generation.
937 * -EIO is returned if the device can't ever be a wakeup event source.
938 * -EINVAL is returned if the device can't generate wakeup events from
939 * the specified PCI state. Returns zero if the operation is successful.
941 int pci_enable_wake(struct pci_dev *dev, pci_power_t state, int enable)
943 int pm;
944 int status;
945 u16 value;
947 /* Note that drivers should verify device_may_wakeup(&dev->dev)
948 * before calling this function. Platform code should report
949 * errors when drivers try to enable wakeup on devices that
950 * can't issue wakeups, or on which wakeups were disabled by
951 * userspace updating the /sys/devices.../power/wakeup file.
954 status = call_platform_enable_wakeup(&dev->dev, enable);
956 /* find PCI PM capability in list */
957 pm = pci_find_capability(dev, PCI_CAP_ID_PM);
959 /* If device doesn't support PM Capabilities, but caller wants to
960 * disable wake events, it's a NOP. Otherwise fail unless the
961 * platform hooks handled this legacy device already.
963 if (!pm)
964 return enable ? status : 0;
966 /* Check device's ability to generate PME# */
967 pci_read_config_word(dev,pm+PCI_PM_PMC,&value);
969 value &= PCI_PM_CAP_PME_MASK;
970 value >>= ffs(PCI_PM_CAP_PME_MASK) - 1; /* First bit of mask */
972 /* Check if it can generate PME# from requested state. */
973 if (!value || !(value & (1 << state))) {
974 /* if it can't, revert what the platform hook changed,
975 * always reporting the base "EINVAL, can't PME#" error
977 if (enable)
978 call_platform_enable_wakeup(&dev->dev, 0);
979 return enable ? -EINVAL : 0;
982 pci_read_config_word(dev, pm + PCI_PM_CTRL, &value);
984 /* Clear PME_Status by writing 1 to it and enable PME# */
985 value |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE;
987 if (!enable)
988 value &= ~PCI_PM_CTRL_PME_ENABLE;
990 pci_write_config_word(dev, pm + PCI_PM_CTRL, value);
992 return 0;
996 pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge)
998 u8 pin;
1000 pin = dev->pin;
1001 if (!pin)
1002 return -1;
1003 pin--;
1004 while (dev->bus->self) {
1005 pin = (pin + PCI_SLOT(dev->devfn)) % 4;
1006 dev = dev->bus->self;
1008 *bridge = dev;
1009 return pin;
1013 * pci_release_region - Release a PCI bar
1014 * @pdev: PCI device whose resources were previously reserved by pci_request_region
1015 * @bar: BAR to release
1017 * Releases the PCI I/O and memory resources previously reserved by a
1018 * successful call to pci_request_region. Call this function only
1019 * after all use of the PCI regions has ceased.
1021 void pci_release_region(struct pci_dev *pdev, int bar)
1023 struct pci_devres *dr;
1025 if (pci_resource_len(pdev, bar) == 0)
1026 return;
1027 if (pci_resource_flags(pdev, bar) & IORESOURCE_IO)
1028 release_region(pci_resource_start(pdev, bar),
1029 pci_resource_len(pdev, bar));
1030 else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM)
1031 release_mem_region(pci_resource_start(pdev, bar),
1032 pci_resource_len(pdev, bar));
1034 dr = find_pci_dr(pdev);
1035 if (dr)
1036 dr->region_mask &= ~(1 << bar);
1040 * pci_request_region - Reserved PCI I/O and memory resource
1041 * @pdev: PCI device whose resources are to be reserved
1042 * @bar: BAR to be reserved
1043 * @res_name: Name to be associated with resource.
1045 * Mark the PCI region associated with PCI device @pdev BR @bar as
1046 * being reserved by owner @res_name. Do not access any
1047 * address inside the PCI regions unless this call returns
1048 * successfully.
1050 * Returns 0 on success, or %EBUSY on error. A warning
1051 * message is also printed on failure.
1053 int pci_request_region(struct pci_dev *pdev, int bar, const char *res_name)
1055 struct pci_devres *dr;
1057 if (pci_resource_len(pdev, bar) == 0)
1058 return 0;
1060 if (pci_resource_flags(pdev, bar) & IORESOURCE_IO) {
1061 if (!request_region(pci_resource_start(pdev, bar),
1062 pci_resource_len(pdev, bar), res_name))
1063 goto err_out;
1065 else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM) {
1066 if (!request_mem_region(pci_resource_start(pdev, bar),
1067 pci_resource_len(pdev, bar), res_name))
1068 goto err_out;
1071 dr = find_pci_dr(pdev);
1072 if (dr)
1073 dr->region_mask |= 1 << bar;
1075 return 0;
1077 err_out:
1078 printk (KERN_WARNING "PCI: Unable to reserve %s region #%d:%llx@%llx "
1079 "for device %s\n",
1080 pci_resource_flags(pdev, bar) & IORESOURCE_IO ? "I/O" : "mem",
1081 bar + 1, /* PCI BAR # */
1082 (unsigned long long)pci_resource_len(pdev, bar),
1083 (unsigned long long)pci_resource_start(pdev, bar),
1084 pci_name(pdev));
1085 return -EBUSY;
1089 * pci_release_selected_regions - Release selected PCI I/O and memory resources
1090 * @pdev: PCI device whose resources were previously reserved
1091 * @bars: Bitmask of BARs to be released
1093 * Release selected PCI I/O and memory resources previously reserved.
1094 * Call this function only after all use of the PCI regions has ceased.
1096 void pci_release_selected_regions(struct pci_dev *pdev, int bars)
1098 int i;
1100 for (i = 0; i < 6; i++)
1101 if (bars & (1 << i))
1102 pci_release_region(pdev, i);
1106 * pci_request_selected_regions - Reserve selected PCI I/O and memory resources
1107 * @pdev: PCI device whose resources are to be reserved
1108 * @bars: Bitmask of BARs to be requested
1109 * @res_name: Name to be associated with resource
1111 int pci_request_selected_regions(struct pci_dev *pdev, int bars,
1112 const char *res_name)
1114 int i;
1116 for (i = 0; i < 6; i++)
1117 if (bars & (1 << i))
1118 if(pci_request_region(pdev, i, res_name))
1119 goto err_out;
1120 return 0;
1122 err_out:
1123 while(--i >= 0)
1124 if (bars & (1 << i))
1125 pci_release_region(pdev, i);
1127 return -EBUSY;
1131 * pci_release_regions - Release reserved PCI I/O and memory resources
1132 * @pdev: PCI device whose resources were previously reserved by pci_request_regions
1134 * Releases all PCI I/O and memory resources previously reserved by a
1135 * successful call to pci_request_regions. Call this function only
1136 * after all use of the PCI regions has ceased.
1139 void pci_release_regions(struct pci_dev *pdev)
1141 pci_release_selected_regions(pdev, (1 << 6) - 1);
1145 * pci_request_regions - Reserved PCI I/O and memory resources
1146 * @pdev: PCI device whose resources are to be reserved
1147 * @res_name: Name to be associated with resource.
1149 * Mark all PCI regions associated with PCI device @pdev as
1150 * being reserved by owner @res_name. Do not access any
1151 * address inside the PCI regions unless this call returns
1152 * successfully.
1154 * Returns 0 on success, or %EBUSY on error. A warning
1155 * message is also printed on failure.
1157 int pci_request_regions(struct pci_dev *pdev, const char *res_name)
1159 return pci_request_selected_regions(pdev, ((1 << 6) - 1), res_name);
1163 * pci_set_master - enables bus-mastering for device dev
1164 * @dev: the PCI device to enable
1166 * Enables bus-mastering on the device and calls pcibios_set_master()
1167 * to do the needed arch specific settings.
1169 void
1170 pci_set_master(struct pci_dev *dev)
1172 u16 cmd;
1174 pci_read_config_word(dev, PCI_COMMAND, &cmd);
1175 if (! (cmd & PCI_COMMAND_MASTER)) {
1176 pr_debug("PCI: Enabling bus mastering for device %s\n", pci_name(dev));
1177 cmd |= PCI_COMMAND_MASTER;
1178 pci_write_config_word(dev, PCI_COMMAND, cmd);
1180 dev->is_busmaster = 1;
1181 pcibios_set_master(dev);
1184 #ifdef PCI_DISABLE_MWI
1185 int pci_set_mwi(struct pci_dev *dev)
1187 return 0;
1190 void pci_clear_mwi(struct pci_dev *dev)
1194 #else
1196 #ifndef PCI_CACHE_LINE_BYTES
1197 #define PCI_CACHE_LINE_BYTES L1_CACHE_BYTES
1198 #endif
1200 /* This can be overridden by arch code. */
1201 /* Don't forget this is measured in 32-bit words, not bytes */
1202 u8 pci_cache_line_size = PCI_CACHE_LINE_BYTES / 4;
1205 * pci_set_cacheline_size - ensure the CACHE_LINE_SIZE register is programmed
1206 * @dev: the PCI device for which MWI is to be enabled
1208 * Helper function for pci_set_mwi.
1209 * Originally copied from drivers/net/acenic.c.
1210 * Copyright 1998-2001 by Jes Sorensen, <jes@trained-monkey.org>.
1212 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1214 static int
1215 pci_set_cacheline_size(struct pci_dev *dev)
1217 u8 cacheline_size;
1219 if (!pci_cache_line_size)
1220 return -EINVAL; /* The system doesn't support MWI. */
1222 /* Validate current setting: the PCI_CACHE_LINE_SIZE must be
1223 equal to or multiple of the right value. */
1224 pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
1225 if (cacheline_size >= pci_cache_line_size &&
1226 (cacheline_size % pci_cache_line_size) == 0)
1227 return 0;
1229 /* Write the correct value. */
1230 pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, pci_cache_line_size);
1231 /* Read it back. */
1232 pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
1233 if (cacheline_size == pci_cache_line_size)
1234 return 0;
1236 printk(KERN_DEBUG "PCI: cache line size of %d is not supported "
1237 "by device %s\n", pci_cache_line_size << 2, pci_name(dev));
1239 return -EINVAL;
1243 * pci_set_mwi - enables memory-write-invalidate PCI transaction
1244 * @dev: the PCI device for which MWI is enabled
1246 * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND,
1247 * and then calls @pcibios_set_mwi to do the needed arch specific
1248 * operations or a generic mwi-prep function.
1250 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1253 pci_set_mwi(struct pci_dev *dev)
1255 int rc;
1256 u16 cmd;
1258 rc = pci_set_cacheline_size(dev);
1259 if (rc)
1260 return rc;
1262 pci_read_config_word(dev, PCI_COMMAND, &cmd);
1263 if (! (cmd & PCI_COMMAND_INVALIDATE)) {
1264 pr_debug("PCI: Enabling Mem-Wr-Inval for device %s\n", pci_name(dev));
1265 cmd |= PCI_COMMAND_INVALIDATE;
1266 pci_write_config_word(dev, PCI_COMMAND, cmd);
1269 return 0;
1273 * pci_clear_mwi - disables Memory-Write-Invalidate for device dev
1274 * @dev: the PCI device to disable
1276 * Disables PCI Memory-Write-Invalidate transaction on the device
1278 void
1279 pci_clear_mwi(struct pci_dev *dev)
1281 u16 cmd;
1283 pci_read_config_word(dev, PCI_COMMAND, &cmd);
1284 if (cmd & PCI_COMMAND_INVALIDATE) {
1285 cmd &= ~PCI_COMMAND_INVALIDATE;
1286 pci_write_config_word(dev, PCI_COMMAND, cmd);
1289 #endif /* ! PCI_DISABLE_MWI */
1292 * pci_intx - enables/disables PCI INTx for device dev
1293 * @pdev: the PCI device to operate on
1294 * @enable: boolean: whether to enable or disable PCI INTx
1296 * Enables/disables PCI INTx for device dev
1298 void
1299 pci_intx(struct pci_dev *pdev, int enable)
1301 u16 pci_command, new;
1303 pci_read_config_word(pdev, PCI_COMMAND, &pci_command);
1305 if (enable) {
1306 new = pci_command & ~PCI_COMMAND_INTX_DISABLE;
1307 } else {
1308 new = pci_command | PCI_COMMAND_INTX_DISABLE;
1311 if (new != pci_command) {
1312 struct pci_devres *dr;
1314 pci_write_config_word(pdev, PCI_COMMAND, new);
1316 dr = find_pci_dr(pdev);
1317 if (dr && !dr->restore_intx) {
1318 dr->restore_intx = 1;
1319 dr->orig_intx = !enable;
1325 * pci_msi_off - disables any msi or msix capabilities
1326 * @dev: the PCI device to operate on
1328 * If you want to use msi see pci_enable_msi and friends.
1329 * This is a lower level primitive that allows us to disable
1330 * msi operation at the device level.
1332 void pci_msi_off(struct pci_dev *dev)
1334 int pos;
1335 u16 control;
1337 pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
1338 if (pos) {
1339 pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control);
1340 control &= ~PCI_MSI_FLAGS_ENABLE;
1341 pci_write_config_word(dev, pos + PCI_MSI_FLAGS, control);
1343 pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
1344 if (pos) {
1345 pci_read_config_word(dev, pos + PCI_MSIX_FLAGS, &control);
1346 control &= ~PCI_MSIX_FLAGS_ENABLE;
1347 pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control);
1351 #ifndef HAVE_ARCH_PCI_SET_DMA_MASK
1353 * These can be overridden by arch-specific implementations
1356 pci_set_dma_mask(struct pci_dev *dev, u64 mask)
1358 if (!pci_dma_supported(dev, mask))
1359 return -EIO;
1361 dev->dma_mask = mask;
1363 return 0;
1367 pci_set_consistent_dma_mask(struct pci_dev *dev, u64 mask)
1369 if (!pci_dma_supported(dev, mask))
1370 return -EIO;
1372 dev->dev.coherent_dma_mask = mask;
1374 return 0;
1376 #endif
1379 * pci_select_bars - Make BAR mask from the type of resource
1380 * @dev: the PCI device for which BAR mask is made
1381 * @flags: resource type mask to be selected
1383 * This helper routine makes bar mask from the type of resource.
1385 int pci_select_bars(struct pci_dev *dev, unsigned long flags)
1387 int i, bars = 0;
1388 for (i = 0; i < PCI_NUM_RESOURCES; i++)
1389 if (pci_resource_flags(dev, i) & flags)
1390 bars |= (1 << i);
1391 return bars;
1394 static int __devinit pci_init(void)
1396 struct pci_dev *dev = NULL;
1398 while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
1399 pci_fixup_device(pci_fixup_final, dev);
1401 return 0;
1404 static int __devinit pci_setup(char *str)
1406 while (str) {
1407 char *k = strchr(str, ',');
1408 if (k)
1409 *k++ = 0;
1410 if (*str && (str = pcibios_setup(str)) && *str) {
1411 if (!strcmp(str, "nomsi")) {
1412 pci_no_msi();
1413 } else if (!strncmp(str, "cbiosize=", 9)) {
1414 pci_cardbus_io_size = memparse(str + 9, &str);
1415 } else if (!strncmp(str, "cbmemsize=", 10)) {
1416 pci_cardbus_mem_size = memparse(str + 10, &str);
1417 } else {
1418 printk(KERN_ERR "PCI: Unknown option `%s'\n",
1419 str);
1422 str = k;
1424 return 0;
1426 early_param("pci", pci_setup);
1428 device_initcall(pci_init);
1430 EXPORT_SYMBOL_GPL(pci_restore_bars);
1431 EXPORT_SYMBOL(pci_enable_device_bars);
1432 EXPORT_SYMBOL(pci_enable_device);
1433 EXPORT_SYMBOL(pcim_enable_device);
1434 EXPORT_SYMBOL(pcim_pin_device);
1435 EXPORT_SYMBOL(pci_disable_device);
1436 EXPORT_SYMBOL(pci_find_capability);
1437 EXPORT_SYMBOL(pci_bus_find_capability);
1438 EXPORT_SYMBOL(pci_release_regions);
1439 EXPORT_SYMBOL(pci_request_regions);
1440 EXPORT_SYMBOL(pci_release_region);
1441 EXPORT_SYMBOL(pci_request_region);
1442 EXPORT_SYMBOL(pci_release_selected_regions);
1443 EXPORT_SYMBOL(pci_request_selected_regions);
1444 EXPORT_SYMBOL(pci_set_master);
1445 EXPORT_SYMBOL(pci_set_mwi);
1446 EXPORT_SYMBOL(pci_clear_mwi);
1447 EXPORT_SYMBOL_GPL(pci_intx);
1448 EXPORT_SYMBOL(pci_set_dma_mask);
1449 EXPORT_SYMBOL(pci_set_consistent_dma_mask);
1450 EXPORT_SYMBOL(pci_assign_resource);
1451 EXPORT_SYMBOL(pci_find_parent_resource);
1452 EXPORT_SYMBOL(pci_select_bars);
1454 EXPORT_SYMBOL(pci_set_power_state);
1455 EXPORT_SYMBOL(pci_save_state);
1456 EXPORT_SYMBOL(pci_restore_state);
1457 EXPORT_SYMBOL(pci_enable_wake);
1458 EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state);