2 * probe.c - PCI detection and setup code
5 #include <linux/kernel.h>
6 #include <linux/delay.h>
7 #include <linux/init.h>
9 #include <linux/slab.h>
10 #include <linux/module.h>
11 #include <linux/cpumask.h>
12 #include <linux/pci-aspm.h>
15 #define CARDBUS_LATENCY_TIMER 176 /* secondary latency timer */
16 #define CARDBUS_RESERVE_BUSNR 3
18 /* Ugh. Need to stop exporting this to modules. */
19 LIST_HEAD(pci_root_buses
);
20 EXPORT_SYMBOL(pci_root_buses
);
23 static int find_anything(struct device
*dev
, void *data
)
29 * Some device drivers need know if pci is initiated.
30 * Basically, we think pci is not initiated when there
31 * is no device to be found on the pci_bus_type.
33 int no_pci_devices(void)
38 dev
= bus_find_device(&pci_bus_type
, NULL
, NULL
, find_anything
);
39 no_devices
= (dev
== NULL
);
43 EXPORT_SYMBOL(no_pci_devices
);
48 static void release_pcibus_dev(struct device
*dev
)
50 struct pci_bus
*pci_bus
= to_pci_bus(dev
);
53 put_device(pci_bus
->bridge
);
54 pci_bus_remove_resources(pci_bus
);
58 static struct class pcibus_class
= {
60 .dev_release
= &release_pcibus_dev
,
61 .dev_attrs
= pcibus_dev_attrs
,
64 static int __init
pcibus_class_init(void)
66 return class_register(&pcibus_class
);
68 postcore_initcall(pcibus_class_init
);
71 * Translate the low bits of the PCI base
72 * to the resource type
74 static inline unsigned int pci_calc_resource_flags(unsigned int flags
)
76 if (flags
& PCI_BASE_ADDRESS_SPACE_IO
)
79 if (flags
& PCI_BASE_ADDRESS_MEM_PREFETCH
)
80 return IORESOURCE_MEM
| IORESOURCE_PREFETCH
;
82 return IORESOURCE_MEM
;
85 static u64
pci_size(u64 base
, u64 maxbase
, u64 mask
)
87 u64 size
= mask
& maxbase
; /* Find the significant bits */
91 /* Get the lowest of them to find the decode size, and
92 from that the extent. */
93 size
= (size
& ~(size
-1)) - 1;
95 /* base == maxbase can be valid only if the BAR has
96 already been programmed with all 1s. */
97 if (base
== maxbase
&& ((base
| size
) & mask
) != mask
)
103 static inline enum pci_bar_type
decode_bar(struct resource
*res
, u32 bar
)
105 if ((bar
& PCI_BASE_ADDRESS_SPACE
) == PCI_BASE_ADDRESS_SPACE_IO
) {
106 res
->flags
= bar
& ~PCI_BASE_ADDRESS_IO_MASK
;
110 res
->flags
= bar
& ~PCI_BASE_ADDRESS_MEM_MASK
;
112 if (res
->flags
& PCI_BASE_ADDRESS_MEM_TYPE_64
)
113 return pci_bar_mem64
;
114 return pci_bar_mem32
;
118 * pci_read_base - read a PCI BAR
119 * @dev: the PCI device
120 * @type: type of the BAR
121 * @res: resource buffer to be filled in
122 * @pos: BAR position in the config space
124 * Returns 1 if the BAR is 64-bit, or 0 if 32-bit.
126 int __pci_read_base(struct pci_dev
*dev
, enum pci_bar_type type
,
127 struct resource
*res
, unsigned int pos
)
132 mask
= type
? PCI_ROM_ADDRESS_MASK
: ~0;
134 if (!dev
->mmio_always_on
) {
135 pci_read_config_word(dev
, PCI_COMMAND
, &orig_cmd
);
136 pci_write_config_word(dev
, PCI_COMMAND
,
137 orig_cmd
& ~(PCI_COMMAND_MEMORY
| PCI_COMMAND_IO
));
140 res
->name
= pci_name(dev
);
142 pci_read_config_dword(dev
, pos
, &l
);
143 pci_write_config_dword(dev
, pos
, l
| mask
);
144 pci_read_config_dword(dev
, pos
, &sz
);
145 pci_write_config_dword(dev
, pos
, l
);
147 if (!dev
->mmio_always_on
)
148 pci_write_config_word(dev
, PCI_COMMAND
, orig_cmd
);
151 * All bits set in sz means the device isn't working properly.
152 * If the BAR isn't implemented, all bits must be 0. If it's a
153 * memory BAR or a ROM, bit 0 must be clear; if it's an io BAR, bit
156 if (!sz
|| sz
== 0xffffffff)
160 * I don't know how l can have all bits set. Copied from old code.
161 * Maybe it fixes a bug on some ancient platform.
166 if (type
== pci_bar_unknown
) {
167 type
= decode_bar(res
, l
);
168 res
->flags
|= pci_calc_resource_flags(l
) | IORESOURCE_SIZEALIGN
;
169 if (type
== pci_bar_io
) {
170 l
&= PCI_BASE_ADDRESS_IO_MASK
;
171 mask
= PCI_BASE_ADDRESS_IO_MASK
& (u32
) IO_SPACE_LIMIT
;
173 l
&= PCI_BASE_ADDRESS_MEM_MASK
;
174 mask
= (u32
)PCI_BASE_ADDRESS_MEM_MASK
;
177 res
->flags
|= (l
& IORESOURCE_ROM_ENABLE
);
178 l
&= PCI_ROM_ADDRESS_MASK
;
179 mask
= (u32
)PCI_ROM_ADDRESS_MASK
;
182 if (type
== pci_bar_mem64
) {
185 u64 mask64
= mask
| (u64
)~0 << 32;
187 pci_read_config_dword(dev
, pos
+ 4, &l
);
188 pci_write_config_dword(dev
, pos
+ 4, ~0);
189 pci_read_config_dword(dev
, pos
+ 4, &sz
);
190 pci_write_config_dword(dev
, pos
+ 4, l
);
192 l64
|= ((u64
)l
<< 32);
193 sz64
|= ((u64
)sz
<< 32);
195 sz64
= pci_size(l64
, sz64
, mask64
);
200 if ((sizeof(resource_size_t
) < 8) && (sz64
> 0x100000000ULL
)) {
201 dev_err(&dev
->dev
, "reg %x: can't handle 64-bit BAR\n",
206 res
->flags
|= IORESOURCE_MEM_64
;
207 if ((sizeof(resource_size_t
) < 8) && l
) {
208 /* Address above 32-bit boundary; disable the BAR */
209 pci_write_config_dword(dev
, pos
, 0);
210 pci_write_config_dword(dev
, pos
+ 4, 0);
215 res
->end
= l64
+ sz64
;
216 dev_printk(KERN_DEBUG
, &dev
->dev
, "reg %x: %pR\n",
220 sz
= pci_size(l
, sz
, mask
);
228 dev_printk(KERN_DEBUG
, &dev
->dev
, "reg %x: %pR\n", pos
, res
);
232 return (type
== pci_bar_mem64
) ? 1 : 0;
238 static void pci_read_bases(struct pci_dev
*dev
, unsigned int howmany
, int rom
)
240 unsigned int pos
, reg
;
242 for (pos
= 0; pos
< howmany
; pos
++) {
243 struct resource
*res
= &dev
->resource
[pos
];
244 reg
= PCI_BASE_ADDRESS_0
+ (pos
<< 2);
245 pos
+= __pci_read_base(dev
, pci_bar_unknown
, res
, reg
);
249 struct resource
*res
= &dev
->resource
[PCI_ROM_RESOURCE
];
250 dev
->rom_base_reg
= rom
;
251 res
->flags
= IORESOURCE_MEM
| IORESOURCE_PREFETCH
|
252 IORESOURCE_READONLY
| IORESOURCE_CACHEABLE
|
253 IORESOURCE_SIZEALIGN
;
254 __pci_read_base(dev
, pci_bar_mem32
, res
, rom
);
258 static void __devinit
pci_read_bridge_io(struct pci_bus
*child
)
260 struct pci_dev
*dev
= child
->self
;
261 u8 io_base_lo
, io_limit_lo
;
262 unsigned long base
, limit
;
263 struct resource
*res
;
265 res
= child
->resource
[0];
266 pci_read_config_byte(dev
, PCI_IO_BASE
, &io_base_lo
);
267 pci_read_config_byte(dev
, PCI_IO_LIMIT
, &io_limit_lo
);
268 base
= (io_base_lo
& PCI_IO_RANGE_MASK
) << 8;
269 limit
= (io_limit_lo
& PCI_IO_RANGE_MASK
) << 8;
271 if ((io_base_lo
& PCI_IO_RANGE_TYPE_MASK
) == PCI_IO_RANGE_TYPE_32
) {
272 u16 io_base_hi
, io_limit_hi
;
273 pci_read_config_word(dev
, PCI_IO_BASE_UPPER16
, &io_base_hi
);
274 pci_read_config_word(dev
, PCI_IO_LIMIT_UPPER16
, &io_limit_hi
);
275 base
|= (io_base_hi
<< 16);
276 limit
|= (io_limit_hi
<< 16);
279 if (base
&& base
<= limit
) {
280 res
->flags
= (io_base_lo
& PCI_IO_RANGE_TYPE_MASK
) | IORESOURCE_IO
;
284 res
->end
= limit
+ 0xfff;
285 dev_printk(KERN_DEBUG
, &dev
->dev
, " bridge window %pR\n", res
);
287 dev_printk(KERN_DEBUG
, &dev
->dev
,
288 " bridge window [io %#06lx-%#06lx] (disabled)\n",
293 static void __devinit
pci_read_bridge_mmio(struct pci_bus
*child
)
295 struct pci_dev
*dev
= child
->self
;
296 u16 mem_base_lo
, mem_limit_lo
;
297 unsigned long base
, limit
;
298 struct resource
*res
;
300 res
= child
->resource
[1];
301 pci_read_config_word(dev
, PCI_MEMORY_BASE
, &mem_base_lo
);
302 pci_read_config_word(dev
, PCI_MEMORY_LIMIT
, &mem_limit_lo
);
303 base
= (mem_base_lo
& PCI_MEMORY_RANGE_MASK
) << 16;
304 limit
= (mem_limit_lo
& PCI_MEMORY_RANGE_MASK
) << 16;
305 if (base
&& base
<= limit
) {
306 res
->flags
= (mem_base_lo
& PCI_MEMORY_RANGE_TYPE_MASK
) | IORESOURCE_MEM
;
308 res
->end
= limit
+ 0xfffff;
309 dev_printk(KERN_DEBUG
, &dev
->dev
, " bridge window %pR\n", res
);
311 dev_printk(KERN_DEBUG
, &dev
->dev
,
312 " bridge window [mem %#010lx-%#010lx] (disabled)\n",
313 base
, limit
+ 0xfffff);
317 static void __devinit
pci_read_bridge_mmio_pref(struct pci_bus
*child
)
319 struct pci_dev
*dev
= child
->self
;
320 u16 mem_base_lo
, mem_limit_lo
;
321 unsigned long base
, limit
;
322 struct resource
*res
;
324 res
= child
->resource
[2];
325 pci_read_config_word(dev
, PCI_PREF_MEMORY_BASE
, &mem_base_lo
);
326 pci_read_config_word(dev
, PCI_PREF_MEMORY_LIMIT
, &mem_limit_lo
);
327 base
= (mem_base_lo
& PCI_PREF_RANGE_MASK
) << 16;
328 limit
= (mem_limit_lo
& PCI_PREF_RANGE_MASK
) << 16;
330 if ((mem_base_lo
& PCI_PREF_RANGE_TYPE_MASK
) == PCI_PREF_RANGE_TYPE_64
) {
331 u32 mem_base_hi
, mem_limit_hi
;
332 pci_read_config_dword(dev
, PCI_PREF_BASE_UPPER32
, &mem_base_hi
);
333 pci_read_config_dword(dev
, PCI_PREF_LIMIT_UPPER32
, &mem_limit_hi
);
336 * Some bridges set the base > limit by default, and some
337 * (broken) BIOSes do not initialize them. If we find
338 * this, just assume they are not being used.
340 if (mem_base_hi
<= mem_limit_hi
) {
341 #if BITS_PER_LONG == 64
342 base
|= ((long) mem_base_hi
) << 32;
343 limit
|= ((long) mem_limit_hi
) << 32;
345 if (mem_base_hi
|| mem_limit_hi
) {
346 dev_err(&dev
->dev
, "can't handle 64-bit "
347 "address space for bridge\n");
353 if (base
&& base
<= limit
) {
354 res
->flags
= (mem_base_lo
& PCI_PREF_RANGE_TYPE_MASK
) |
355 IORESOURCE_MEM
| IORESOURCE_PREFETCH
;
356 if (res
->flags
& PCI_PREF_RANGE_TYPE_64
)
357 res
->flags
|= IORESOURCE_MEM_64
;
359 res
->end
= limit
+ 0xfffff;
360 dev_printk(KERN_DEBUG
, &dev
->dev
, " bridge window %pR\n", res
);
362 dev_printk(KERN_DEBUG
, &dev
->dev
,
363 " bridge window [mem %#010lx-%#010lx pref] (disabled)\n",
364 base
, limit
+ 0xfffff);
368 void __devinit
pci_read_bridge_bases(struct pci_bus
*child
)
370 struct pci_dev
*dev
= child
->self
;
371 struct resource
*res
;
374 if (pci_is_root_bus(child
)) /* It's a host bus, nothing to read */
377 dev_info(&dev
->dev
, "PCI bridge to [bus %02x-%02x]%s\n",
378 child
->secondary
, child
->subordinate
,
379 dev
->transparent
? " (subtractive decode)" : "");
381 pci_bus_remove_resources(child
);
382 for (i
= 0; i
< PCI_BRIDGE_RESOURCE_NUM
; i
++)
383 child
->resource
[i
] = &dev
->resource
[PCI_BRIDGE_RESOURCES
+i
];
385 pci_read_bridge_io(child
);
386 pci_read_bridge_mmio(child
);
387 pci_read_bridge_mmio_pref(child
);
389 if (dev
->transparent
) {
390 pci_bus_for_each_resource(child
->parent
, res
, i
) {
392 pci_bus_add_resource(child
, res
,
393 PCI_SUBTRACTIVE_DECODE
);
394 dev_printk(KERN_DEBUG
, &dev
->dev
,
395 " bridge window %pR (subtractive decode)\n",
402 static struct pci_bus
* pci_alloc_bus(void)
406 b
= kzalloc(sizeof(*b
), GFP_KERNEL
);
408 INIT_LIST_HEAD(&b
->node
);
409 INIT_LIST_HEAD(&b
->children
);
410 INIT_LIST_HEAD(&b
->devices
);
411 INIT_LIST_HEAD(&b
->slots
);
412 INIT_LIST_HEAD(&b
->resources
);
413 b
->max_bus_speed
= PCI_SPEED_UNKNOWN
;
414 b
->cur_bus_speed
= PCI_SPEED_UNKNOWN
;
419 static unsigned char pcix_bus_speed
[] = {
420 PCI_SPEED_UNKNOWN
, /* 0 */
421 PCI_SPEED_66MHz_PCIX
, /* 1 */
422 PCI_SPEED_100MHz_PCIX
, /* 2 */
423 PCI_SPEED_133MHz_PCIX
, /* 3 */
424 PCI_SPEED_UNKNOWN
, /* 4 */
425 PCI_SPEED_66MHz_PCIX_ECC
, /* 5 */
426 PCI_SPEED_100MHz_PCIX_ECC
, /* 6 */
427 PCI_SPEED_133MHz_PCIX_ECC
, /* 7 */
428 PCI_SPEED_UNKNOWN
, /* 8 */
429 PCI_SPEED_66MHz_PCIX_266
, /* 9 */
430 PCI_SPEED_100MHz_PCIX_266
, /* A */
431 PCI_SPEED_133MHz_PCIX_266
, /* B */
432 PCI_SPEED_UNKNOWN
, /* C */
433 PCI_SPEED_66MHz_PCIX_533
, /* D */
434 PCI_SPEED_100MHz_PCIX_533
, /* E */
435 PCI_SPEED_133MHz_PCIX_533
/* F */
438 static unsigned char pcie_link_speed
[] = {
439 PCI_SPEED_UNKNOWN
, /* 0 */
440 PCIE_SPEED_2_5GT
, /* 1 */
441 PCIE_SPEED_5_0GT
, /* 2 */
442 PCIE_SPEED_8_0GT
, /* 3 */
443 PCI_SPEED_UNKNOWN
, /* 4 */
444 PCI_SPEED_UNKNOWN
, /* 5 */
445 PCI_SPEED_UNKNOWN
, /* 6 */
446 PCI_SPEED_UNKNOWN
, /* 7 */
447 PCI_SPEED_UNKNOWN
, /* 8 */
448 PCI_SPEED_UNKNOWN
, /* 9 */
449 PCI_SPEED_UNKNOWN
, /* A */
450 PCI_SPEED_UNKNOWN
, /* B */
451 PCI_SPEED_UNKNOWN
, /* C */
452 PCI_SPEED_UNKNOWN
, /* D */
453 PCI_SPEED_UNKNOWN
, /* E */
454 PCI_SPEED_UNKNOWN
/* F */
457 void pcie_update_link_speed(struct pci_bus
*bus
, u16 linksta
)
459 bus
->cur_bus_speed
= pcie_link_speed
[linksta
& 0xf];
461 EXPORT_SYMBOL_GPL(pcie_update_link_speed
);
463 static unsigned char agp_speeds
[] = {
471 static enum pci_bus_speed
agp_speed(int agp3
, int agpstat
)
477 else if (agpstat
& 2)
479 else if (agpstat
& 1)
491 return agp_speeds
[index
];
495 static void pci_set_bus_speed(struct pci_bus
*bus
)
497 struct pci_dev
*bridge
= bus
->self
;
500 pos
= pci_find_capability(bridge
, PCI_CAP_ID_AGP
);
502 pos
= pci_find_capability(bridge
, PCI_CAP_ID_AGP3
);
506 pci_read_config_dword(bridge
, pos
+ PCI_AGP_STATUS
, &agpstat
);
507 bus
->max_bus_speed
= agp_speed(agpstat
& 8, agpstat
& 7);
509 pci_read_config_dword(bridge
, pos
+ PCI_AGP_COMMAND
, &agpcmd
);
510 bus
->cur_bus_speed
= agp_speed(agpstat
& 8, agpcmd
& 7);
513 pos
= pci_find_capability(bridge
, PCI_CAP_ID_PCIX
);
516 enum pci_bus_speed max
;
517 pci_read_config_word(bridge
, pos
+ 2, &status
);
519 if (status
& 0x8000) {
520 max
= PCI_SPEED_133MHz_PCIX_533
;
521 } else if (status
& 0x4000) {
522 max
= PCI_SPEED_133MHz_PCIX_266
;
523 } else if (status
& 0x0002) {
524 if (((status
>> 12) & 0x3) == 2) {
525 max
= PCI_SPEED_133MHz_PCIX_ECC
;
527 max
= PCI_SPEED_133MHz_PCIX
;
530 max
= PCI_SPEED_66MHz_PCIX
;
533 bus
->max_bus_speed
= max
;
534 bus
->cur_bus_speed
= pcix_bus_speed
[(status
>> 6) & 0xf];
539 pos
= pci_find_capability(bridge
, PCI_CAP_ID_EXP
);
544 pci_read_config_dword(bridge
, pos
+ PCI_EXP_LNKCAP
, &linkcap
);
545 bus
->max_bus_speed
= pcie_link_speed
[linkcap
& 0xf];
547 pci_read_config_word(bridge
, pos
+ PCI_EXP_LNKSTA
, &linksta
);
548 pcie_update_link_speed(bus
, linksta
);
553 static struct pci_bus
*pci_alloc_child_bus(struct pci_bus
*parent
,
554 struct pci_dev
*bridge
, int busnr
)
556 struct pci_bus
*child
;
560 * Allocate a new bus, and inherit stuff from the parent..
562 child
= pci_alloc_bus();
566 child
->parent
= parent
;
567 child
->ops
= parent
->ops
;
568 child
->sysdata
= parent
->sysdata
;
569 child
->bus_flags
= parent
->bus_flags
;
571 /* initialize some portions of the bus device, but don't register it
572 * now as the parent is not properly set up yet. This device will get
573 * registered later in pci_bus_add_devices()
575 child
->dev
.class = &pcibus_class
;
576 dev_set_name(&child
->dev
, "%04x:%02x", pci_domain_nr(child
), busnr
);
579 * Set up the primary, secondary and subordinate
582 child
->number
= child
->secondary
= busnr
;
583 child
->primary
= parent
->secondary
;
584 child
->subordinate
= 0xff;
589 child
->self
= bridge
;
590 child
->bridge
= get_device(&bridge
->dev
);
592 pci_set_bus_speed(child
);
594 /* Set up default resource pointers and names.. */
595 for (i
= 0; i
< PCI_BRIDGE_RESOURCE_NUM
; i
++) {
596 child
->resource
[i
] = &bridge
->resource
[PCI_BRIDGE_RESOURCES
+i
];
597 child
->resource
[i
]->name
= child
->name
;
599 bridge
->subordinate
= child
;
604 struct pci_bus
*__ref
pci_add_new_bus(struct pci_bus
*parent
, struct pci_dev
*dev
, int busnr
)
606 struct pci_bus
*child
;
608 child
= pci_alloc_child_bus(parent
, dev
, busnr
);
610 down_write(&pci_bus_sem
);
611 list_add_tail(&child
->node
, &parent
->children
);
612 up_write(&pci_bus_sem
);
617 static void pci_fixup_parent_subordinate_busnr(struct pci_bus
*child
, int max
)
619 struct pci_bus
*parent
= child
->parent
;
621 /* Attempts to fix that up are really dangerous unless
622 we're going to re-assign all bus numbers. */
623 if (!pcibios_assign_all_busses())
626 while (parent
->parent
&& parent
->subordinate
< max
) {
627 parent
->subordinate
= max
;
628 pci_write_config_byte(parent
->self
, PCI_SUBORDINATE_BUS
, max
);
629 parent
= parent
->parent
;
634 * If it's a bridge, configure it and scan the bus behind it.
635 * For CardBus bridges, we don't scan behind as the devices will
636 * be handled by the bridge driver itself.
638 * We need to process bridges in two passes -- first we scan those
639 * already configured by the BIOS and after we are done with all of
640 * them, we proceed to assigning numbers to the remaining buses in
641 * order to avoid overlaps between old and new bus numbers.
643 int __devinit
pci_scan_bridge(struct pci_bus
*bus
, struct pci_dev
*dev
, int max
, int pass
)
645 struct pci_bus
*child
;
646 int is_cardbus
= (dev
->hdr_type
== PCI_HEADER_TYPE_CARDBUS
);
649 u8 primary
, secondary
, subordinate
;
652 pci_read_config_dword(dev
, PCI_PRIMARY_BUS
, &buses
);
653 primary
= buses
& 0xFF;
654 secondary
= (buses
>> 8) & 0xFF;
655 subordinate
= (buses
>> 16) & 0xFF;
657 dev_dbg(&dev
->dev
, "scanning [bus %02x-%02x] behind bridge, pass %d\n",
658 secondary
, subordinate
, pass
);
660 /* Check if setup is sensible at all */
662 (primary
!= bus
->number
|| secondary
<= bus
->number
)) {
663 dev_dbg(&dev
->dev
, "bus configuration invalid, reconfiguring\n");
667 /* Disable MasterAbortMode during probing to avoid reporting
668 of bus errors (in some architectures) */
669 pci_read_config_word(dev
, PCI_BRIDGE_CONTROL
, &bctl
);
670 pci_write_config_word(dev
, PCI_BRIDGE_CONTROL
,
671 bctl
& ~PCI_BRIDGE_CTL_MASTER_ABORT
);
673 if ((secondary
|| subordinate
) && !pcibios_assign_all_busses() &&
674 !is_cardbus
&& !broken
) {
677 * Bus already configured by firmware, process it in the first
678 * pass and just note the configuration.
684 * If we already got to this bus through a different bridge,
685 * don't re-add it. This can happen with the i450NX chipset.
687 * However, we continue to descend down the hierarchy and
688 * scan remaining child buses.
690 child
= pci_find_bus(pci_domain_nr(bus
), secondary
);
692 child
= pci_add_new_bus(bus
, dev
, secondary
);
695 child
->primary
= primary
;
696 child
->subordinate
= subordinate
;
697 child
->bridge_ctl
= bctl
;
700 cmax
= pci_scan_child_bus(child
);
703 if (child
->subordinate
> max
)
704 max
= child
->subordinate
;
707 * We need to assign a number to this bus which we always
708 * do in the second pass.
711 if (pcibios_assign_all_busses() || broken
)
712 /* Temporarily disable forwarding of the
713 configuration cycles on all bridges in
714 this bus segment to avoid possible
715 conflicts in the second pass between two
716 bridges programmed with overlapping
718 pci_write_config_dword(dev
, PCI_PRIMARY_BUS
,
724 pci_write_config_word(dev
, PCI_STATUS
, 0xffff);
726 /* Prevent assigning a bus number that already exists.
727 * This can happen when a bridge is hot-plugged */
728 if (pci_find_bus(pci_domain_nr(bus
), max
+1))
730 child
= pci_add_new_bus(bus
, dev
, ++max
);
733 buses
= (buses
& 0xff000000)
734 | ((unsigned int)(child
->primary
) << 0)
735 | ((unsigned int)(child
->secondary
) << 8)
736 | ((unsigned int)(child
->subordinate
) << 16);
739 * yenta.c forces a secondary latency timer of 176.
740 * Copy that behaviour here.
743 buses
&= ~0xff000000;
744 buses
|= CARDBUS_LATENCY_TIMER
<< 24;
748 * We need to blast all three values with a single write.
750 pci_write_config_dword(dev
, PCI_PRIMARY_BUS
, buses
);
753 child
->bridge_ctl
= bctl
;
755 * Adjust subordinate busnr in parent buses.
756 * We do this before scanning for children because
757 * some devices may not be detected if the bios
760 pci_fixup_parent_subordinate_busnr(child
, max
);
761 /* Now we can scan all subordinate buses... */
762 max
= pci_scan_child_bus(child
);
764 * now fix it up again since we have found
765 * the real value of max.
767 pci_fixup_parent_subordinate_busnr(child
, max
);
770 * For CardBus bridges, we leave 4 bus numbers
771 * as cards with a PCI-to-PCI bridge can be
774 for (i
=0; i
<CARDBUS_RESERVE_BUSNR
; i
++) {
775 struct pci_bus
*parent
= bus
;
776 if (pci_find_bus(pci_domain_nr(bus
),
779 while (parent
->parent
) {
780 if ((!pcibios_assign_all_busses()) &&
781 (parent
->subordinate
> max
) &&
782 (parent
->subordinate
<= max
+i
)) {
785 parent
= parent
->parent
;
789 * Often, there are two cardbus bridges
790 * -- try to leave one valid bus number
798 pci_fixup_parent_subordinate_busnr(child
, max
);
801 * Set the subordinate bus number to its real value.
803 child
->subordinate
= max
;
804 pci_write_config_byte(dev
, PCI_SUBORDINATE_BUS
, max
);
808 (is_cardbus
? "PCI CardBus %04x:%02x" : "PCI Bus %04x:%02x"),
809 pci_domain_nr(bus
), child
->number
);
811 /* Has only triggered on CardBus, fixup is in yenta_socket */
812 while (bus
->parent
) {
813 if ((child
->subordinate
> bus
->subordinate
) ||
814 (child
->number
> bus
->subordinate
) ||
815 (child
->number
< bus
->number
) ||
816 (child
->subordinate
< bus
->number
)) {
817 dev_info(&child
->dev
, "[bus %02x-%02x] %s "
818 "hidden behind%s bridge %s [bus %02x-%02x]\n",
819 child
->number
, child
->subordinate
,
820 (bus
->number
> child
->subordinate
&&
821 bus
->subordinate
< child
->number
) ?
822 "wholly" : "partially",
823 bus
->self
->transparent
? " transparent" : "",
825 bus
->number
, bus
->subordinate
);
831 pci_write_config_word(dev
, PCI_BRIDGE_CONTROL
, bctl
);
837 * Read interrupt line and base address registers.
838 * The architecture-dependent code can tweak these, of course.
840 static void pci_read_irq(struct pci_dev
*dev
)
844 pci_read_config_byte(dev
, PCI_INTERRUPT_PIN
, &irq
);
847 pci_read_config_byte(dev
, PCI_INTERRUPT_LINE
, &irq
);
851 void set_pcie_port_type(struct pci_dev
*pdev
)
856 pos
= pci_find_capability(pdev
, PCI_CAP_ID_EXP
);
860 pdev
->pcie_cap
= pos
;
861 pci_read_config_word(pdev
, pos
+ PCI_EXP_FLAGS
, ®16
);
862 pdev
->pcie_type
= (reg16
& PCI_EXP_FLAGS_TYPE
) >> 4;
865 void set_pcie_hotplug_bridge(struct pci_dev
*pdev
)
871 pos
= pci_pcie_cap(pdev
);
874 pci_read_config_word(pdev
, pos
+ PCI_EXP_FLAGS
, ®16
);
875 if (!(reg16
& PCI_EXP_FLAGS_SLOT
))
877 pci_read_config_dword(pdev
, pos
+ PCI_EXP_SLTCAP
, ®32
);
878 if (reg32
& PCI_EXP_SLTCAP_HPC
)
879 pdev
->is_hotplug_bridge
= 1;
882 #define LEGACY_IO_RESOURCE (IORESOURCE_IO | IORESOURCE_PCI_FIXED)
885 * pci_setup_device - fill in class and map information of a device
886 * @dev: the device structure to fill
888 * Initialize the device structure with information about the device's
889 * vendor,class,memory and IO-space addresses,IRQ lines etc.
890 * Called at initialisation of the PCI subsystem and by CardBus services.
891 * Returns 0 on success and negative if unknown type of device (not normal,
892 * bridge or CardBus).
894 int pci_setup_device(struct pci_dev
*dev
)
898 struct pci_slot
*slot
;
901 if (pci_read_config_byte(dev
, PCI_HEADER_TYPE
, &hdr_type
))
904 dev
->sysdata
= dev
->bus
->sysdata
;
905 dev
->dev
.parent
= dev
->bus
->bridge
;
906 dev
->dev
.bus
= &pci_bus_type
;
907 dev
->hdr_type
= hdr_type
& 0x7f;
908 dev
->multifunction
= !!(hdr_type
& 0x80);
909 dev
->error_state
= pci_channel_io_normal
;
910 set_pcie_port_type(dev
);
912 list_for_each_entry(slot
, &dev
->bus
->slots
, list
)
913 if (PCI_SLOT(dev
->devfn
) == slot
->number
)
916 /* Assume 32-bit PCI; let 64-bit PCI cards (which are far rarer)
917 set this higher, assuming the system even supports it. */
918 dev
->dma_mask
= 0xffffffff;
920 dev_set_name(&dev
->dev
, "%04x:%02x:%02x.%d", pci_domain_nr(dev
->bus
),
921 dev
->bus
->number
, PCI_SLOT(dev
->devfn
),
922 PCI_FUNC(dev
->devfn
));
924 pci_read_config_dword(dev
, PCI_CLASS_REVISION
, &class);
925 dev
->revision
= class & 0xff;
926 class >>= 8; /* upper 3 bytes */
930 dev_printk(KERN_DEBUG
, &dev
->dev
, "[%04x:%04x] type %d class %#08x\n",
931 dev
->vendor
, dev
->device
, dev
->hdr_type
, class);
933 /* need to have dev->class ready */
934 dev
->cfg_size
= pci_cfg_space_size(dev
);
936 /* "Unknown power state" */
937 dev
->current_state
= PCI_UNKNOWN
;
939 /* Early fixups, before probing the BARs */
940 pci_fixup_device(pci_fixup_early
, dev
);
941 /* device class may be changed after fixup */
942 class = dev
->class >> 8;
944 switch (dev
->hdr_type
) { /* header type */
945 case PCI_HEADER_TYPE_NORMAL
: /* standard header */
946 if (class == PCI_CLASS_BRIDGE_PCI
)
949 pci_read_bases(dev
, 6, PCI_ROM_ADDRESS
);
950 pci_read_config_word(dev
, PCI_SUBSYSTEM_VENDOR_ID
, &dev
->subsystem_vendor
);
951 pci_read_config_word(dev
, PCI_SUBSYSTEM_ID
, &dev
->subsystem_device
);
954 * Do the ugly legacy mode stuff here rather than broken chip
955 * quirk code. Legacy mode ATA controllers have fixed
956 * addresses. These are not always echoed in BAR0-3, and
957 * BAR0-3 in a few cases contain junk!
959 if (class == PCI_CLASS_STORAGE_IDE
) {
961 pci_read_config_byte(dev
, PCI_CLASS_PROG
, &progif
);
962 if ((progif
& 1) == 0) {
963 dev
->resource
[0].start
= 0x1F0;
964 dev
->resource
[0].end
= 0x1F7;
965 dev
->resource
[0].flags
= LEGACY_IO_RESOURCE
;
966 dev
->resource
[1].start
= 0x3F6;
967 dev
->resource
[1].end
= 0x3F6;
968 dev
->resource
[1].flags
= LEGACY_IO_RESOURCE
;
970 if ((progif
& 4) == 0) {
971 dev
->resource
[2].start
= 0x170;
972 dev
->resource
[2].end
= 0x177;
973 dev
->resource
[2].flags
= LEGACY_IO_RESOURCE
;
974 dev
->resource
[3].start
= 0x376;
975 dev
->resource
[3].end
= 0x376;
976 dev
->resource
[3].flags
= LEGACY_IO_RESOURCE
;
981 case PCI_HEADER_TYPE_BRIDGE
: /* bridge header */
982 if (class != PCI_CLASS_BRIDGE_PCI
)
984 /* The PCI-to-PCI bridge spec requires that subtractive
985 decoding (i.e. transparent) bridge must have programming
986 interface code of 0x01. */
988 dev
->transparent
= ((dev
->class & 0xff) == 1);
989 pci_read_bases(dev
, 2, PCI_ROM_ADDRESS1
);
990 set_pcie_hotplug_bridge(dev
);
991 pos
= pci_find_capability(dev
, PCI_CAP_ID_SSVID
);
993 pci_read_config_word(dev
, pos
+ PCI_SSVID_VENDOR_ID
, &dev
->subsystem_vendor
);
994 pci_read_config_word(dev
, pos
+ PCI_SSVID_DEVICE_ID
, &dev
->subsystem_device
);
998 case PCI_HEADER_TYPE_CARDBUS
: /* CardBus bridge header */
999 if (class != PCI_CLASS_BRIDGE_CARDBUS
)
1002 pci_read_bases(dev
, 1, 0);
1003 pci_read_config_word(dev
, PCI_CB_SUBSYSTEM_VENDOR_ID
, &dev
->subsystem_vendor
);
1004 pci_read_config_word(dev
, PCI_CB_SUBSYSTEM_ID
, &dev
->subsystem_device
);
1007 default: /* unknown header */
1008 dev_err(&dev
->dev
, "unknown header type %02x, "
1009 "ignoring device\n", dev
->hdr_type
);
1013 dev_err(&dev
->dev
, "ignoring class %02x (doesn't match header "
1014 "type %02x)\n", class, dev
->hdr_type
);
1015 dev
->class = PCI_CLASS_NOT_DEFINED
;
1018 /* We found a fine healthy device, go go go... */
1022 static void pci_release_capabilities(struct pci_dev
*dev
)
1024 pci_vpd_release(dev
);
1025 pci_iov_release(dev
);
1029 * pci_release_dev - free a pci device structure when all users of it are finished.
1030 * @dev: device that's been disconnected
1032 * Will be called only by the device core when all users of this pci device are
1035 static void pci_release_dev(struct device
*dev
)
1037 struct pci_dev
*pci_dev
;
1039 pci_dev
= to_pci_dev(dev
);
1040 pci_release_capabilities(pci_dev
);
1045 * pci_cfg_space_size - get the configuration space size of the PCI device.
1048 * Regular PCI devices have 256 bytes, but PCI-X 2 and PCI Express devices
1049 * have 4096 bytes. Even if the device is capable, that doesn't mean we can
1050 * access it. Maybe we don't have a way to generate extended config space
1051 * accesses, or the device is behind a reverse Express bridge. So we try
1052 * reading the dword at 0x100 which must either be 0 or a valid extended
1053 * capability header.
1055 int pci_cfg_space_size_ext(struct pci_dev
*dev
)
1058 int pos
= PCI_CFG_SPACE_SIZE
;
1060 if (pci_read_config_dword(dev
, pos
, &status
) != PCIBIOS_SUCCESSFUL
)
1062 if (status
== 0xffffffff)
1065 return PCI_CFG_SPACE_EXP_SIZE
;
1068 return PCI_CFG_SPACE_SIZE
;
1071 int pci_cfg_space_size(struct pci_dev
*dev
)
1077 class = dev
->class >> 8;
1078 if (class == PCI_CLASS_BRIDGE_HOST
)
1079 return pci_cfg_space_size_ext(dev
);
1081 pos
= pci_pcie_cap(dev
);
1083 pos
= pci_find_capability(dev
, PCI_CAP_ID_PCIX
);
1087 pci_read_config_dword(dev
, pos
+ PCI_X_STATUS
, &status
);
1088 if (!(status
& (PCI_X_STATUS_266MHZ
| PCI_X_STATUS_533MHZ
)))
1092 return pci_cfg_space_size_ext(dev
);
1095 return PCI_CFG_SPACE_SIZE
;
1098 static void pci_release_bus_bridge_dev(struct device
*dev
)
1103 struct pci_dev
*alloc_pci_dev(void)
1105 struct pci_dev
*dev
;
1107 dev
= kzalloc(sizeof(struct pci_dev
), GFP_KERNEL
);
1111 INIT_LIST_HEAD(&dev
->bus_list
);
1115 EXPORT_SYMBOL(alloc_pci_dev
);
1118 * Read the config data for a PCI device, sanity-check it
1119 * and fill in the dev structure...
1121 static struct pci_dev
*pci_scan_device(struct pci_bus
*bus
, int devfn
)
1123 struct pci_dev
*dev
;
1127 if (pci_bus_read_config_dword(bus
, devfn
, PCI_VENDOR_ID
, &l
))
1130 /* some broken boards return 0 or ~0 if a slot is empty: */
1131 if (l
== 0xffffffff || l
== 0x00000000 ||
1132 l
== 0x0000ffff || l
== 0xffff0000)
1135 /* Configuration request Retry Status */
1136 while (l
== 0xffff0001) {
1139 if (pci_bus_read_config_dword(bus
, devfn
, PCI_VENDOR_ID
, &l
))
1141 /* Card hasn't responded in 60 seconds? Must be stuck. */
1142 if (delay
> 60 * 1000) {
1143 printk(KERN_WARNING
"pci %04x:%02x:%02x.%d: not "
1144 "responding\n", pci_domain_nr(bus
),
1145 bus
->number
, PCI_SLOT(devfn
),
1151 dev
= alloc_pci_dev();
1157 dev
->vendor
= l
& 0xffff;
1158 dev
->device
= (l
>> 16) & 0xffff;
1160 if (pci_setup_device(dev
)) {
1168 static void pci_init_capabilities(struct pci_dev
*dev
)
1170 /* MSI/MSI-X list */
1171 pci_msi_init_pci_dev(dev
);
1173 /* Buffers for saving PCIe and PCI-X capabilities */
1174 pci_allocate_cap_save_buffers(dev
);
1176 /* Power Management */
1178 platform_pci_wakeup_init(dev
);
1180 /* Vital Product Data */
1181 pci_vpd_pci22_init(dev
);
1183 /* Alternative Routing-ID Forwarding */
1184 pci_enable_ari(dev
);
1186 /* Single Root I/O Virtualization */
1189 /* Enable ACS P2P upstream forwarding */
1190 pci_enable_acs(dev
);
1193 void pci_device_add(struct pci_dev
*dev
, struct pci_bus
*bus
)
1195 device_initialize(&dev
->dev
);
1196 dev
->dev
.release
= pci_release_dev
;
1199 dev
->dev
.dma_mask
= &dev
->dma_mask
;
1200 dev
->dev
.dma_parms
= &dev
->dma_parms
;
1201 dev
->dev
.coherent_dma_mask
= 0xffffffffull
;
1203 pci_set_dma_max_seg_size(dev
, 65536);
1204 pci_set_dma_seg_boundary(dev
, 0xffffffff);
1206 /* Fix up broken headers */
1207 pci_fixup_device(pci_fixup_header
, dev
);
1209 /* Clear the state_saved flag. */
1210 dev
->state_saved
= false;
1212 /* Initialize various capabilities */
1213 pci_init_capabilities(dev
);
1216 * Add the device to our list of discovered devices
1217 * and the bus list for fixup functions, etc.
1219 down_write(&pci_bus_sem
);
1220 list_add_tail(&dev
->bus_list
, &bus
->devices
);
1221 up_write(&pci_bus_sem
);
1224 struct pci_dev
*__ref
pci_scan_single_device(struct pci_bus
*bus
, int devfn
)
1226 struct pci_dev
*dev
;
1228 dev
= pci_get_slot(bus
, devfn
);
1234 dev
= pci_scan_device(bus
, devfn
);
1238 pci_device_add(dev
, bus
);
1242 EXPORT_SYMBOL(pci_scan_single_device
);
1244 static unsigned next_ari_fn(struct pci_dev
*dev
, unsigned fn
)
1247 unsigned pos
, next_fn
;
1252 pos
= pci_find_ext_capability(dev
, PCI_EXT_CAP_ID_ARI
);
1255 pci_read_config_word(dev
, pos
+ 4, &cap
);
1262 static unsigned next_trad_fn(struct pci_dev
*dev
, unsigned fn
)
1264 return (fn
+ 1) % 8;
1267 static unsigned no_next_fn(struct pci_dev
*dev
, unsigned fn
)
1272 static int only_one_child(struct pci_bus
*bus
)
1274 struct pci_dev
*parent
= bus
->self
;
1275 if (!parent
|| !pci_is_pcie(parent
))
1277 if (parent
->pcie_type
== PCI_EXP_TYPE_ROOT_PORT
||
1278 parent
->pcie_type
== PCI_EXP_TYPE_DOWNSTREAM
)
1284 * pci_scan_slot - scan a PCI slot on a bus for devices.
1285 * @bus: PCI bus to scan
1286 * @devfn: slot number to scan (must have zero function.)
1288 * Scan a PCI slot on the specified PCI bus for devices, adding
1289 * discovered devices to the @bus->devices list. New devices
1290 * will not have is_added set.
1292 * Returns the number of new devices found.
1294 int pci_scan_slot(struct pci_bus
*bus
, int devfn
)
1296 unsigned fn
, nr
= 0;
1297 struct pci_dev
*dev
;
1298 unsigned (*next_fn
)(struct pci_dev
*, unsigned) = no_next_fn
;
1300 if (only_one_child(bus
) && (devfn
> 0))
1301 return 0; /* Already scanned the entire slot */
1303 dev
= pci_scan_single_device(bus
, devfn
);
1309 if (pci_ari_enabled(bus
))
1310 next_fn
= next_ari_fn
;
1311 else if (dev
->multifunction
)
1312 next_fn
= next_trad_fn
;
1314 for (fn
= next_fn(dev
, 0); fn
> 0; fn
= next_fn(dev
, fn
)) {
1315 dev
= pci_scan_single_device(bus
, devfn
+ fn
);
1319 dev
->multifunction
= 1;
1323 /* only one slot has pcie device */
1324 if (bus
->self
&& nr
)
1325 pcie_aspm_init_link_state(bus
->self
);
1330 unsigned int __devinit
pci_scan_child_bus(struct pci_bus
*bus
)
1332 unsigned int devfn
, pass
, max
= bus
->secondary
;
1333 struct pci_dev
*dev
;
1335 dev_dbg(&bus
->dev
, "scanning bus\n");
1337 /* Go find them, Rover! */
1338 for (devfn
= 0; devfn
< 0x100; devfn
+= 8)
1339 pci_scan_slot(bus
, devfn
);
1341 /* Reserve buses for SR-IOV capability. */
1342 max
+= pci_iov_bus_range(bus
);
1345 * After performing arch-dependent fixup of the bus, look behind
1346 * all PCI-to-PCI bridges on this bus.
1348 if (!bus
->is_added
) {
1349 dev_dbg(&bus
->dev
, "fixups for bus\n");
1350 pcibios_fixup_bus(bus
);
1351 if (pci_is_root_bus(bus
))
1355 for (pass
=0; pass
< 2; pass
++)
1356 list_for_each_entry(dev
, &bus
->devices
, bus_list
) {
1357 if (dev
->hdr_type
== PCI_HEADER_TYPE_BRIDGE
||
1358 dev
->hdr_type
== PCI_HEADER_TYPE_CARDBUS
)
1359 max
= pci_scan_bridge(bus
, dev
, max
, pass
);
1363 * We've scanned the bus and so we know all about what's on
1364 * the other side of any bridges that may be on this bus plus
1367 * Return how far we've got finding sub-buses.
1369 dev_dbg(&bus
->dev
, "bus scan returning with max=%02x\n", max
);
1373 struct pci_bus
* pci_create_bus(struct device
*parent
,
1374 int bus
, struct pci_ops
*ops
, void *sysdata
)
1377 struct pci_bus
*b
, *b2
;
1380 b
= pci_alloc_bus();
1384 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
1390 b
->sysdata
= sysdata
;
1393 b2
= pci_find_bus(pci_domain_nr(b
), bus
);
1395 /* If we already got to this bus through a different bridge, ignore it */
1396 dev_dbg(&b2
->dev
, "bus already known\n");
1400 down_write(&pci_bus_sem
);
1401 list_add_tail(&b
->node
, &pci_root_buses
);
1402 up_write(&pci_bus_sem
);
1404 dev
->parent
= parent
;
1405 dev
->release
= pci_release_bus_bridge_dev
;
1406 dev_set_name(dev
, "pci%04x:%02x", pci_domain_nr(b
), bus
);
1407 error
= device_register(dev
);
1410 b
->bridge
= get_device(dev
);
1411 device_enable_async_suspend(b
->bridge
);
1414 set_dev_node(b
->bridge
, pcibus_to_node(b
));
1416 b
->dev
.class = &pcibus_class
;
1417 b
->dev
.parent
= b
->bridge
;
1418 dev_set_name(&b
->dev
, "%04x:%02x", pci_domain_nr(b
), bus
);
1419 error
= device_register(&b
->dev
);
1421 goto class_dev_reg_err
;
1423 /* Create legacy_io and legacy_mem files for this bus */
1424 pci_create_legacy_files(b
);
1426 b
->number
= b
->secondary
= bus
;
1427 b
->resource
[0] = &ioport_resource
;
1428 b
->resource
[1] = &iomem_resource
;
1433 device_unregister(dev
);
1435 down_write(&pci_bus_sem
);
1437 up_write(&pci_bus_sem
);
1444 struct pci_bus
* __devinit
pci_scan_bus_parented(struct device
*parent
,
1445 int bus
, struct pci_ops
*ops
, void *sysdata
)
1449 b
= pci_create_bus(parent
, bus
, ops
, sysdata
);
1451 b
->subordinate
= pci_scan_child_bus(b
);
1454 EXPORT_SYMBOL(pci_scan_bus_parented
);
1456 #ifdef CONFIG_HOTPLUG
1458 * pci_rescan_bus - scan a PCI bus for devices.
1459 * @bus: PCI bus to scan
1461 * Scan a PCI bus and child buses for new devices, adds them,
1464 * Returns the max number of subordinate bus discovered.
1466 unsigned int __ref
pci_rescan_bus(struct pci_bus
*bus
)
1469 struct pci_dev
*dev
;
1471 max
= pci_scan_child_bus(bus
);
1473 down_read(&pci_bus_sem
);
1474 list_for_each_entry(dev
, &bus
->devices
, bus_list
)
1475 if (dev
->hdr_type
== PCI_HEADER_TYPE_BRIDGE
||
1476 dev
->hdr_type
== PCI_HEADER_TYPE_CARDBUS
)
1477 if (dev
->subordinate
)
1478 pci_bus_size_bridges(dev
->subordinate
);
1479 up_read(&pci_bus_sem
);
1481 pci_bus_assign_resources(bus
);
1482 pci_enable_bridges(bus
);
1483 pci_bus_add_devices(bus
);
1487 EXPORT_SYMBOL_GPL(pci_rescan_bus
);
1489 EXPORT_SYMBOL(pci_add_new_bus
);
1490 EXPORT_SYMBOL(pci_scan_slot
);
1491 EXPORT_SYMBOL(pci_scan_bridge
);
1492 EXPORT_SYMBOL_GPL(pci_scan_child_bus
);
1495 static int __init
pci_sort_bf_cmp(const struct device
*d_a
, const struct device
*d_b
)
1497 const struct pci_dev
*a
= to_pci_dev(d_a
);
1498 const struct pci_dev
*b
= to_pci_dev(d_b
);
1500 if (pci_domain_nr(a
->bus
) < pci_domain_nr(b
->bus
)) return -1;
1501 else if (pci_domain_nr(a
->bus
) > pci_domain_nr(b
->bus
)) return 1;
1503 if (a
->bus
->number
< b
->bus
->number
) return -1;
1504 else if (a
->bus
->number
> b
->bus
->number
) return 1;
1506 if (a
->devfn
< b
->devfn
) return -1;
1507 else if (a
->devfn
> b
->devfn
) return 1;
1512 void __init
pci_sort_breadthfirst(void)
1514 bus_sort_breadthfirst(&pci_bus_type
, &pci_sort_bf_cmp
);