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,
9 * Copyright 1997 -- 2000 Martin Mares <mj@ucw.cz>
12 #include <linux/delay.h>
13 #include <linux/init.h>
14 #include <linux/pci.h>
15 #include <linux/module.h>
16 #include <linux/spinlock.h>
17 #include <asm/dma.h> /* isa_dma_bridge_buggy */
22 #define DBG(x...) printk(x)
28 * pci_bus_max_busnr - returns maximum PCI bus number of given bus' children
29 * @bus: pointer to PCI bus structure to search
31 * Given a PCI bus, returns the highest PCI bus number present in the set
32 * including the given PCI bus and its list of child PCI buses.
34 unsigned char __devinit
35 pci_bus_max_busnr(struct pci_bus
* bus
)
37 struct list_head
*tmp
;
41 list_for_each(tmp
, &bus
->children
) {
42 n
= pci_bus_max_busnr(pci_bus_b(tmp
));
50 * pci_max_busnr - returns maximum PCI bus number
52 * Returns the highest PCI bus number present in the system global list of
55 unsigned char __devinit
58 struct pci_bus
*bus
= NULL
;
62 while ((bus
= pci_find_next_bus(bus
)) != NULL
) {
63 n
= pci_bus_max_busnr(bus
);
70 static int __pci_bus_find_cap(struct pci_bus
*bus
, unsigned int devfn
, u8 hdr_type
, int cap
)
76 pci_bus_read_config_word(bus
, devfn
, PCI_STATUS
, &status
);
77 if (!(status
& PCI_STATUS_CAP_LIST
))
81 case PCI_HEADER_TYPE_NORMAL
:
82 case PCI_HEADER_TYPE_BRIDGE
:
83 pci_bus_read_config_byte(bus
, devfn
, PCI_CAPABILITY_LIST
, &pos
);
85 case PCI_HEADER_TYPE_CARDBUS
:
86 pci_bus_read_config_byte(bus
, devfn
, PCI_CB_CAPABILITY_LIST
, &pos
);
91 while (ttl
-- && pos
>= 0x40) {
93 pci_bus_read_config_byte(bus
, devfn
, pos
+ PCI_CAP_LIST_ID
, &id
);
98 pci_bus_read_config_byte(bus
, devfn
, pos
+ PCI_CAP_LIST_NEXT
, &pos
);
104 * pci_find_capability - query for devices' capabilities
105 * @dev: PCI device to query
106 * @cap: capability code
108 * Tell if a device supports a given PCI capability.
109 * Returns the address of the requested capability structure within the
110 * device's PCI configuration space or 0 in case the device does not
111 * support it. Possible values for @cap:
113 * %PCI_CAP_ID_PM Power Management
114 * %PCI_CAP_ID_AGP Accelerated Graphics Port
115 * %PCI_CAP_ID_VPD Vital Product Data
116 * %PCI_CAP_ID_SLOTID Slot Identification
117 * %PCI_CAP_ID_MSI Message Signalled Interrupts
118 * %PCI_CAP_ID_CHSWP CompactPCI HotSwap
119 * %PCI_CAP_ID_PCIX PCI-X
120 * %PCI_CAP_ID_EXP PCI Express
122 int pci_find_capability(struct pci_dev
*dev
, int cap
)
124 return __pci_bus_find_cap(dev
->bus
, dev
->devfn
, dev
->hdr_type
, cap
);
128 * pci_bus_find_capability - query for devices' capabilities
129 * @bus: the PCI bus to query
130 * @devfn: PCI device to query
131 * @cap: capability code
133 * Like pci_find_capability() but works for pci devices that do not have a
134 * pci_dev structure set up yet.
136 * Returns the address of the requested capability structure within the
137 * device's PCI configuration space or 0 in case the device does not
140 int pci_bus_find_capability(struct pci_bus
*bus
, unsigned int devfn
, int cap
)
144 pci_bus_read_config_byte(bus
, devfn
, PCI_HEADER_TYPE
, &hdr_type
);
146 return __pci_bus_find_cap(bus
, devfn
, hdr_type
& 0x7f, cap
);
150 * pci_find_ext_capability - Find an extended capability
151 * @dev: PCI device to query
152 * @cap: capability code
154 * Returns the address of the requested extended capability structure
155 * within the device's PCI configuration space or 0 if the device does
156 * not support it. Possible values for @cap:
158 * %PCI_EXT_CAP_ID_ERR Advanced Error Reporting
159 * %PCI_EXT_CAP_ID_VC Virtual Channel
160 * %PCI_EXT_CAP_ID_DSN Device Serial Number
161 * %PCI_EXT_CAP_ID_PWR Power Budgeting
163 int pci_find_ext_capability(struct pci_dev
*dev
, int cap
)
166 int ttl
= 480; /* 3840 bytes, minimum 8 bytes per capability */
169 if (dev
->cfg_size
<= 256)
172 if (pci_read_config_dword(dev
, pos
, &header
) != PCIBIOS_SUCCESSFUL
)
176 * If we have no capabilities, this is indicated by cap ID,
177 * cap version and next pointer all being 0.
183 if (PCI_EXT_CAP_ID(header
) == cap
)
186 pos
= PCI_EXT_CAP_NEXT(header
);
190 if (pci_read_config_dword(dev
, pos
, &header
) != PCIBIOS_SUCCESSFUL
)
198 * pci_find_parent_resource - return resource region of parent bus of given region
199 * @dev: PCI device structure contains resources to be searched
200 * @res: child resource record for which parent is sought
202 * For given resource region of given device, return the resource
203 * region of parent bus the given region is contained in or where
204 * it should be allocated from.
207 pci_find_parent_resource(const struct pci_dev
*dev
, struct resource
*res
)
209 const struct pci_bus
*bus
= dev
->bus
;
211 struct resource
*best
= NULL
;
213 for(i
= 0; i
< PCI_BUS_NUM_RESOURCES
; i
++) {
214 struct resource
*r
= bus
->resource
[i
];
217 if (res
->start
&& !(res
->start
>= r
->start
&& res
->end
<= r
->end
))
218 continue; /* Not contained */
219 if ((res
->flags
^ r
->flags
) & (IORESOURCE_IO
| IORESOURCE_MEM
))
220 continue; /* Wrong type */
221 if (!((res
->flags
^ r
->flags
) & IORESOURCE_PREFETCH
))
222 return r
; /* Exact match */
223 if ((res
->flags
& IORESOURCE_PREFETCH
) && !(r
->flags
& IORESOURCE_PREFETCH
))
224 best
= r
; /* Approximating prefetchable by non-prefetchable */
230 * pci_set_power_state - Set the power state of a PCI device
231 * @dev: PCI device to be suspended
232 * @state: Power state we're entering
234 * Transition a device to a new power state, using the Power Management
235 * Capabilities in the device's config space.
238 * -EINVAL if trying to enter a lower state than we're already in.
239 * 0 if we're already in the requested state.
240 * -EIO if device does not support PCI PM.
241 * 0 if we can successfully change the power state.
245 pci_set_power_state(struct pci_dev
*dev
, int state
)
250 /* bound the state we're entering */
251 if (state
> 3) state
= 3;
253 /* Validate current state:
254 * Can enter D0 from any state, but if we can only go deeper
255 * to sleep if we're already in a low power state
257 if (state
> 0 && dev
->current_state
> state
)
259 else if (dev
->current_state
== state
)
260 return 0; /* we're already there */
262 /* find PCI PM capability in list */
263 pm
= pci_find_capability(dev
, PCI_CAP_ID_PM
);
265 /* abort if the device doesn't support PM capabilities */
266 if (!pm
) return -EIO
;
268 /* check if this device supports the desired state */
269 if (state
== 1 || state
== 2) {
271 pci_read_config_word(dev
,pm
+ PCI_PM_PMC
,&pmc
);
272 if (state
== 1 && !(pmc
& PCI_PM_CAP_D1
)) return -EIO
;
273 else if (state
== 2 && !(pmc
& PCI_PM_CAP_D2
)) return -EIO
;
276 /* If we're in D3, force entire word to 0.
277 * This doesn't affect PME_Status, disables PME_En, and
278 * sets PowerState to 0.
280 if (dev
->current_state
>= 3)
283 pci_read_config_word(dev
, pm
+ PCI_PM_CTRL
, &pmcsr
);
284 pmcsr
&= ~PCI_PM_CTRL_STATE_MASK
;
288 /* enter specified state */
289 pci_write_config_word(dev
, pm
+ PCI_PM_CTRL
, pmcsr
);
291 /* Mandatory power management transition delays */
292 /* see PCI PM 1.1 5.6.1 table 18 */
293 if(state
== 3 || dev
->current_state
== 3)
295 else if(state
== 2 || dev
->current_state
== 2)
297 dev
->current_state
= state
;
303 * pci_save_state - save the PCI configuration space of a device before suspending
304 * @dev: - PCI device that we're dealing with
305 * @buffer: - buffer to hold config space context
307 * @buffer must be large enough to hold the entire PCI 2.2 config space
311 pci_save_state(struct pci_dev
*dev
, u32
*buffer
)
315 /* XXX: 100% dword access ok here? */
316 for (i
= 0; i
< 16; i
++)
317 pci_read_config_dword(dev
, i
* 4,&buffer
[i
]);
323 * pci_restore_state - Restore the saved state of a PCI device
324 * @dev: - PCI device that we're dealing with
325 * @buffer: - saved PCI config space
329 pci_restore_state(struct pci_dev
*dev
, u32
*buffer
)
334 for (i
= 0; i
< 16; i
++)
335 pci_write_config_dword(dev
,i
* 4, buffer
[i
]);
338 * otherwise, write the context information we know from bootup.
339 * This works around a problem where warm-booting from Windows
340 * combined with a D3(hot)->D0 transition causes PCI config
341 * header data to be forgotten.
344 for (i
= 0; i
< 6; i
++)
345 pci_write_config_dword(dev
,
346 PCI_BASE_ADDRESS_0
+ (i
* 4),
347 dev
->resource
[i
].start
);
348 pci_write_config_byte(dev
, PCI_INTERRUPT_LINE
, dev
->irq
);
354 * pci_enable_device_bars - Initialize some of a device for use
355 * @dev: PCI device to be initialized
356 * @bars: bitmask of BAR's that must be configured
358 * Initialize device before it's used by a driver. Ask low-level code
359 * to enable selected I/O and memory resources. Wake up the device if it
360 * was suspended. Beware, this function can fail.
364 pci_enable_device_bars(struct pci_dev
*dev
, int bars
)
368 pci_set_power_state(dev
, 0);
369 if ((err
= pcibios_enable_device(dev
, bars
)) < 0)
375 * pci_enable_device - Initialize device before it's used by a driver.
376 * @dev: PCI device to be initialized
378 * Initialize device before it's used by a driver. Ask low-level code
379 * to enable I/O and memory. Wake up the device if it was suspended.
380 * Beware, this function can fail.
383 pci_enable_device(struct pci_dev
*dev
)
386 return pci_enable_device_bars(dev
, (1 << PCI_NUM_RESOURCES
) - 1);
390 * pci_disable_device - Disable PCI device after use
391 * @dev: PCI device to be disabled
393 * Signal to the system that the PCI device is not in use by the system
394 * anymore. This only involves disabling PCI bus-mastering, if active.
397 pci_disable_device(struct pci_dev
*dev
)
402 dev
->is_busmaster
= 0;
404 pci_read_config_word(dev
, PCI_COMMAND
, &pci_command
);
405 if (pci_command
& PCI_COMMAND_MASTER
) {
406 pci_command
&= ~PCI_COMMAND_MASTER
;
407 pci_write_config_word(dev
, PCI_COMMAND
, pci_command
);
412 * pci_enable_wake - enable device to generate PME# when suspended
413 * @dev: - PCI device to operate on
414 * @state: - Current state of device.
415 * @enable: - Flag to enable or disable generation
417 * Set the bits in the device's PM Capabilities to generate PME# when
418 * the system is suspended.
420 * -EIO is returned if device doesn't have PM Capabilities.
421 * -EINVAL is returned if device supports it, but can't generate wake events.
422 * 0 if operation is successful.
425 int pci_enable_wake(struct pci_dev
*dev
, u32 state
, int enable
)
430 /* find PCI PM capability in list */
431 pm
= pci_find_capability(dev
, PCI_CAP_ID_PM
);
433 /* If device doesn't support PM Capabilities, but request is to disable
434 * wake events, it's a nop; otherwise fail */
436 return enable
? -EIO
: 0;
438 /* Check device's ability to generate PME# */
439 pci_read_config_word(dev
,pm
+PCI_PM_PMC
,&value
);
441 value
&= PCI_PM_CAP_PME_MASK
;
442 value
>>= ffs(PCI_PM_CAP_PME_MASK
) - 1; /* First bit of mask */
444 /* Check if it can generate PME# from requested state. */
445 if (!value
|| !(value
& (1 << state
)))
446 return enable
? -EINVAL
: 0;
448 pci_read_config_word(dev
, pm
+ PCI_PM_CTRL
, &value
);
450 /* Clear PME_Status by writing 1 to it and enable PME# */
451 value
|= PCI_PM_CTRL_PME_STATUS
| PCI_PM_CTRL_PME_ENABLE
;
454 value
&= ~PCI_PM_CTRL_PME_ENABLE
;
456 pci_write_config_word(dev
, pm
+ PCI_PM_CTRL
, value
);
462 pci_get_interrupt_pin(struct pci_dev
*dev
, struct pci_dev
**bridge
)
466 pci_read_config_byte(dev
, PCI_INTERRUPT_PIN
, &pin
);
470 while (dev
->bus
->self
) {
471 pin
= (pin
+ PCI_SLOT(dev
->devfn
)) % 4;
472 dev
= dev
->bus
->self
;
479 * pci_release_region - Release a PCI bar
480 * @pdev: PCI device whose resources were previously reserved by pci_request_region
481 * @bar: BAR to release
483 * Releases the PCI I/O and memory resources previously reserved by a
484 * successful call to pci_request_region. Call this function only
485 * after all use of the PCI regions has ceased.
487 void pci_release_region(struct pci_dev
*pdev
, int bar
)
489 if (pci_resource_len(pdev
, bar
) == 0)
491 if (pci_resource_flags(pdev
, bar
) & IORESOURCE_IO
)
492 release_region(pci_resource_start(pdev
, bar
),
493 pci_resource_len(pdev
, bar
));
494 else if (pci_resource_flags(pdev
, bar
) & IORESOURCE_MEM
)
495 release_mem_region(pci_resource_start(pdev
, bar
),
496 pci_resource_len(pdev
, bar
));
500 * pci_request_region - Reserved PCI I/O and memory resource
501 * @pdev: PCI device whose resources are to be reserved
502 * @bar: BAR to be reserved
503 * @res_name: Name to be associated with resource.
505 * Mark the PCI region associated with PCI device @pdev BR @bar as
506 * being reserved by owner @res_name. Do not access any
507 * address inside the PCI regions unless this call returns
510 * Returns 0 on success, or %EBUSY on error. A warning
511 * message is also printed on failure.
513 int pci_request_region(struct pci_dev
*pdev
, int bar
, char *res_name
)
515 if (pci_resource_len(pdev
, bar
) == 0)
518 if (pci_resource_flags(pdev
, bar
) & IORESOURCE_IO
) {
519 if (!request_region(pci_resource_start(pdev
, bar
),
520 pci_resource_len(pdev
, bar
), res_name
))
523 else if (pci_resource_flags(pdev
, bar
) & IORESOURCE_MEM
) {
524 if (!request_mem_region(pci_resource_start(pdev
, bar
),
525 pci_resource_len(pdev
, bar
), res_name
))
532 printk (KERN_WARNING
"PCI: Unable to reserve %s region #%d:%lx@%lx for device %s\n",
533 pci_resource_flags(pdev
, bar
) & IORESOURCE_IO
? "I/O" : "mem",
534 bar
+ 1, /* PCI BAR # */
535 pci_resource_len(pdev
, bar
), pci_resource_start(pdev
, bar
),
542 * pci_release_regions - Release reserved PCI I/O and memory resources
543 * @pdev: PCI device whose resources were previously reserved by pci_request_regions
545 * Releases all PCI I/O and memory resources previously reserved by a
546 * successful call to pci_request_regions. Call this function only
547 * after all use of the PCI regions has ceased.
550 void pci_release_regions(struct pci_dev
*pdev
)
554 for (i
= 0; i
< 6; i
++)
555 pci_release_region(pdev
, i
);
559 * pci_request_regions - Reserved PCI I/O and memory resources
560 * @pdev: PCI device whose resources are to be reserved
561 * @res_name: Name to be associated with resource.
563 * Mark all PCI regions associated with PCI device @pdev as
564 * being reserved by owner @res_name. Do not access any
565 * address inside the PCI regions unless this call returns
568 * Returns 0 on success, or %EBUSY on error. A warning
569 * message is also printed on failure.
571 int pci_request_regions(struct pci_dev
*pdev
, char *res_name
)
575 for (i
= 0; i
< 6; i
++)
576 if(pci_request_region(pdev
, i
, res_name
))
582 pci_release_region(pdev
, i
);
588 * pci_set_master - enables bus-mastering for device dev
589 * @dev: the PCI device to enable
591 * Enables bus-mastering on the device and calls pcibios_set_master()
592 * to do the needed arch specific settings.
595 pci_set_master(struct pci_dev
*dev
)
599 pci_read_config_word(dev
, PCI_COMMAND
, &cmd
);
600 if (! (cmd
& PCI_COMMAND_MASTER
)) {
601 DBG("PCI: Enabling bus mastering for device %s\n", pci_name(dev
));
602 cmd
|= PCI_COMMAND_MASTER
;
603 pci_write_config_word(dev
, PCI_COMMAND
, cmd
);
605 dev
->is_busmaster
= 1;
606 pcibios_set_master(dev
);
609 #ifndef HAVE_ARCH_PCI_MWI
610 /* This can be overridden by arch code. */
611 u8 pci_cache_line_size
= L1_CACHE_BYTES
>> 2;
614 * pci_generic_prep_mwi - helper function for pci_set_mwi
615 * @dev: the PCI device for which MWI is enabled
617 * Helper function for generic implementation of pcibios_prep_mwi
618 * function. Originally copied from drivers/net/acenic.c.
619 * Copyright 1998-2001 by Jes Sorensen, <jes@trained-monkey.org>.
621 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
624 pci_generic_prep_mwi(struct pci_dev
*dev
)
628 if (!pci_cache_line_size
)
629 return -EINVAL
; /* The system doesn't support MWI. */
631 /* Validate current setting: the PCI_CACHE_LINE_SIZE must be
632 equal to or multiple of the right value. */
633 pci_read_config_byte(dev
, PCI_CACHE_LINE_SIZE
, &cacheline_size
);
634 if (cacheline_size
>= pci_cache_line_size
&&
635 (cacheline_size
% pci_cache_line_size
) == 0)
638 /* Write the correct value. */
639 pci_write_config_byte(dev
, PCI_CACHE_LINE_SIZE
, pci_cache_line_size
);
641 pci_read_config_byte(dev
, PCI_CACHE_LINE_SIZE
, &cacheline_size
);
642 if (cacheline_size
== pci_cache_line_size
)
645 printk(KERN_DEBUG
"PCI: cache line size of %d is not supported "
646 "by device %s\n", pci_cache_line_size
<< 2, pci_name(dev
));
650 #endif /* !HAVE_ARCH_PCI_MWI */
653 * pci_set_mwi - enables memory-write-invalidate PCI transaction
654 * @dev: the PCI device for which MWI is enabled
656 * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND,
657 * and then calls @pcibios_set_mwi to do the needed arch specific
658 * operations or a generic mwi-prep function.
660 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
663 pci_set_mwi(struct pci_dev
*dev
)
668 #ifdef HAVE_ARCH_PCI_MWI
669 rc
= pcibios_prep_mwi(dev
);
671 rc
= pci_generic_prep_mwi(dev
);
677 pci_read_config_word(dev
, PCI_COMMAND
, &cmd
);
678 if (! (cmd
& PCI_COMMAND_INVALIDATE
)) {
679 DBG("PCI: Enabling Mem-Wr-Inval for device %s\n", pci_name(dev
));
680 cmd
|= PCI_COMMAND_INVALIDATE
;
681 pci_write_config_word(dev
, PCI_COMMAND
, cmd
);
688 * pci_clear_mwi - disables Memory-Write-Invalidate for device dev
689 * @dev: the PCI device to disable
691 * Disables PCI Memory-Write-Invalidate transaction on the device
694 pci_clear_mwi(struct pci_dev
*dev
)
698 pci_read_config_word(dev
, PCI_COMMAND
, &cmd
);
699 if (cmd
& PCI_COMMAND_INVALIDATE
) {
700 cmd
&= ~PCI_COMMAND_INVALIDATE
;
701 pci_write_config_word(dev
, PCI_COMMAND
, cmd
);
705 #ifndef HAVE_ARCH_PCI_SET_DMA_MASK
707 * These can be overridden by arch-specific implementations
710 pci_set_dma_mask(struct pci_dev
*dev
, u64 mask
)
712 if (!pci_dma_supported(dev
, mask
))
715 dev
->dma_mask
= mask
;
721 pci_dac_set_dma_mask(struct pci_dev
*dev
, u64 mask
)
723 if (!pci_dac_dma_supported(dev
, mask
))
726 dev
->dma_mask
= mask
;
732 pci_set_consistent_dma_mask(struct pci_dev
*dev
, u64 mask
)
734 if (!pci_dma_supported(dev
, mask
))
737 dev
->dev
.coherent_dma_mask
= mask
;
743 static int __devinit
pci_init(void)
745 struct pci_dev
*dev
= NULL
;
747 while ((dev
= pci_find_device(PCI_ANY_ID
, PCI_ANY_ID
, dev
)) != NULL
) {
748 pci_fixup_device(pci_fixup_final
, dev
);
753 static int __devinit
pci_setup(char *str
)
756 char *k
= strchr(str
, ',');
759 if (*str
&& (str
= pcibios_setup(str
)) && *str
) {
760 /* PCI layer options should be handled here */
761 printk(KERN_ERR
"PCI: Unknown option `%s'\n", str
);
768 device_initcall(pci_init
);
770 __setup("pci=", pci_setup
);
772 #if defined(CONFIG_ISA) || defined(CONFIG_EISA)
773 /* FIXME: Some boxes have multiple ISA bridges! */
774 struct pci_dev
*isa_bridge
;
775 EXPORT_SYMBOL(isa_bridge
);
778 EXPORT_SYMBOL(pci_enable_device_bars
);
779 EXPORT_SYMBOL(pci_enable_device
);
780 EXPORT_SYMBOL(pci_disable_device
);
781 EXPORT_SYMBOL(pci_max_busnr
);
782 EXPORT_SYMBOL(pci_bus_max_busnr
);
783 EXPORT_SYMBOL(pci_find_capability
);
784 EXPORT_SYMBOL(pci_bus_find_capability
);
785 EXPORT_SYMBOL(pci_release_regions
);
786 EXPORT_SYMBOL(pci_request_regions
);
787 EXPORT_SYMBOL(pci_release_region
);
788 EXPORT_SYMBOL(pci_request_region
);
789 EXPORT_SYMBOL(pci_set_master
);
790 EXPORT_SYMBOL(pci_set_mwi
);
791 EXPORT_SYMBOL(pci_clear_mwi
);
792 EXPORT_SYMBOL(pci_set_dma_mask
);
793 EXPORT_SYMBOL(pci_dac_set_dma_mask
);
794 EXPORT_SYMBOL(pci_set_consistent_dma_mask
);
795 EXPORT_SYMBOL(pci_assign_resource
);
796 EXPORT_SYMBOL(pci_find_parent_resource
);
798 EXPORT_SYMBOL(pci_set_power_state
);
799 EXPORT_SYMBOL(pci_save_state
);
800 EXPORT_SYMBOL(pci_restore_state
);
801 EXPORT_SYMBOL(pci_enable_wake
);
805 EXPORT_SYMBOL(isa_dma_bridge_buggy
);
806 EXPORT_SYMBOL(pci_pci_problems
);