1 // SPDX-License-Identifier: GPL-2.0
3 * PCI detection and setup code
6 #include <linux/kernel.h>
7 #include <linux/delay.h>
8 #include <linux/init.h>
10 #include <linux/msi.h>
11 #include <linux/of_device.h>
12 #include <linux/of_pci.h>
13 #include <linux/pci_hotplug.h>
14 #include <linux/slab.h>
15 #include <linux/module.h>
16 #include <linux/cpumask.h>
17 #include <linux/aer.h>
18 #include <linux/acpi.h>
19 #include <linux/hypervisor.h>
20 #include <linux/irqdomain.h>
21 #include <linux/pm_runtime.h>
22 #include <linux/list_sort.h>
25 #define CARDBUS_LATENCY_TIMER 176 /* secondary latency timer */
26 #define CARDBUS_RESERVE_BUSNR 3
28 static struct resource busn_resource
= {
32 .flags
= IORESOURCE_BUS
,
35 /* Ugh. Need to stop exporting this to modules. */
36 LIST_HEAD(pci_root_buses
);
37 EXPORT_SYMBOL(pci_root_buses
);
39 static LIST_HEAD(pci_domain_busn_res_list
);
41 struct pci_domain_busn_res
{
42 struct list_head list
;
47 static struct resource
*get_pci_domain_busn_res(int domain_nr
)
49 struct pci_domain_busn_res
*r
;
51 list_for_each_entry(r
, &pci_domain_busn_res_list
, list
)
52 if (r
->domain_nr
== domain_nr
)
55 r
= kzalloc(sizeof(*r
), GFP_KERNEL
);
59 r
->domain_nr
= domain_nr
;
62 r
->res
.flags
= IORESOURCE_BUS
| IORESOURCE_PCI_FIXED
;
64 list_add_tail(&r
->list
, &pci_domain_busn_res_list
);
70 * Some device drivers need know if PCI is initiated.
71 * Basically, we think PCI is not initiated when there
72 * is no device to be found on the pci_bus_type.
74 int no_pci_devices(void)
79 dev
= bus_find_next_device(&pci_bus_type
, NULL
);
80 no_devices
= (dev
== NULL
);
84 EXPORT_SYMBOL(no_pci_devices
);
89 static void release_pcibus_dev(struct device
*dev
)
91 struct pci_bus
*pci_bus
= to_pci_bus(dev
);
93 put_device(pci_bus
->bridge
);
94 pci_bus_remove_resources(pci_bus
);
95 pci_release_bus_of_node(pci_bus
);
99 static struct class pcibus_class
= {
101 .dev_release
= &release_pcibus_dev
,
102 .dev_groups
= pcibus_groups
,
105 static int __init
pcibus_class_init(void)
107 return class_register(&pcibus_class
);
109 postcore_initcall(pcibus_class_init
);
111 static u64
pci_size(u64 base
, u64 maxbase
, u64 mask
)
113 u64 size
= mask
& maxbase
; /* Find the significant bits */
118 * Get the lowest of them to find the decode size, and from that
121 size
= size
& ~(size
-1);
124 * base == maxbase can be valid only if the BAR has already been
125 * programmed with all 1s.
127 if (base
== maxbase
&& ((base
| (size
- 1)) & mask
) != mask
)
133 static inline unsigned long decode_bar(struct pci_dev
*dev
, u32 bar
)
138 if ((bar
& PCI_BASE_ADDRESS_SPACE
) == PCI_BASE_ADDRESS_SPACE_IO
) {
139 flags
= bar
& ~PCI_BASE_ADDRESS_IO_MASK
;
140 flags
|= IORESOURCE_IO
;
144 flags
= bar
& ~PCI_BASE_ADDRESS_MEM_MASK
;
145 flags
|= IORESOURCE_MEM
;
146 if (flags
& PCI_BASE_ADDRESS_MEM_PREFETCH
)
147 flags
|= IORESOURCE_PREFETCH
;
149 mem_type
= bar
& PCI_BASE_ADDRESS_MEM_TYPE_MASK
;
151 case PCI_BASE_ADDRESS_MEM_TYPE_32
:
153 case PCI_BASE_ADDRESS_MEM_TYPE_1M
:
154 /* 1M mem BAR treated as 32-bit BAR */
156 case PCI_BASE_ADDRESS_MEM_TYPE_64
:
157 flags
|= IORESOURCE_MEM_64
;
160 /* mem unknown type treated as 32-bit BAR */
166 #define PCI_COMMAND_DECODE_ENABLE (PCI_COMMAND_MEMORY | PCI_COMMAND_IO)
169 * __pci_read_base - Read a PCI BAR
170 * @dev: the PCI device
171 * @type: type of the BAR
172 * @res: resource buffer to be filled in
173 * @pos: BAR position in the config space
175 * Returns 1 if the BAR is 64-bit, or 0 if 32-bit.
177 int __pci_read_base(struct pci_dev
*dev
, enum pci_bar_type type
,
178 struct resource
*res
, unsigned int pos
)
180 u32 l
= 0, sz
= 0, mask
;
181 u64 l64
, sz64
, mask64
;
183 struct pci_bus_region region
, inverted_region
;
185 mask
= type
? PCI_ROM_ADDRESS_MASK
: ~0;
187 /* No printks while decoding is disabled! */
188 if (!dev
->mmio_always_on
) {
189 pci_read_config_word(dev
, PCI_COMMAND
, &orig_cmd
);
190 if (orig_cmd
& PCI_COMMAND_DECODE_ENABLE
) {
191 pci_write_config_word(dev
, PCI_COMMAND
,
192 orig_cmd
& ~PCI_COMMAND_DECODE_ENABLE
);
196 res
->name
= pci_name(dev
);
198 pci_read_config_dword(dev
, pos
, &l
);
199 pci_write_config_dword(dev
, pos
, l
| mask
);
200 pci_read_config_dword(dev
, pos
, &sz
);
201 pci_write_config_dword(dev
, pos
, l
);
204 * All bits set in sz means the device isn't working properly.
205 * If the BAR isn't implemented, all bits must be 0. If it's a
206 * memory BAR or a ROM, bit 0 must be clear; if it's an io BAR, bit
209 if (sz
== 0xffffffff)
213 * I don't know how l can have all bits set. Copied from old code.
214 * Maybe it fixes a bug on some ancient platform.
219 if (type
== pci_bar_unknown
) {
220 res
->flags
= decode_bar(dev
, l
);
221 res
->flags
|= IORESOURCE_SIZEALIGN
;
222 if (res
->flags
& IORESOURCE_IO
) {
223 l64
= l
& PCI_BASE_ADDRESS_IO_MASK
;
224 sz64
= sz
& PCI_BASE_ADDRESS_IO_MASK
;
225 mask64
= PCI_BASE_ADDRESS_IO_MASK
& (u32
)IO_SPACE_LIMIT
;
227 l64
= l
& PCI_BASE_ADDRESS_MEM_MASK
;
228 sz64
= sz
& PCI_BASE_ADDRESS_MEM_MASK
;
229 mask64
= (u32
)PCI_BASE_ADDRESS_MEM_MASK
;
232 if (l
& PCI_ROM_ADDRESS_ENABLE
)
233 res
->flags
|= IORESOURCE_ROM_ENABLE
;
234 l64
= l
& PCI_ROM_ADDRESS_MASK
;
235 sz64
= sz
& PCI_ROM_ADDRESS_MASK
;
236 mask64
= PCI_ROM_ADDRESS_MASK
;
239 if (res
->flags
& IORESOURCE_MEM_64
) {
240 pci_read_config_dword(dev
, pos
+ 4, &l
);
241 pci_write_config_dword(dev
, pos
+ 4, ~0);
242 pci_read_config_dword(dev
, pos
+ 4, &sz
);
243 pci_write_config_dword(dev
, pos
+ 4, l
);
245 l64
|= ((u64
)l
<< 32);
246 sz64
|= ((u64
)sz
<< 32);
247 mask64
|= ((u64
)~0 << 32);
250 if (!dev
->mmio_always_on
&& (orig_cmd
& PCI_COMMAND_DECODE_ENABLE
))
251 pci_write_config_word(dev
, PCI_COMMAND
, orig_cmd
);
256 sz64
= pci_size(l64
, sz64
, mask64
);
258 pci_info(dev
, FW_BUG
"reg 0x%x: invalid BAR (can't size)\n",
263 if (res
->flags
& IORESOURCE_MEM_64
) {
264 if ((sizeof(pci_bus_addr_t
) < 8 || sizeof(resource_size_t
) < 8)
265 && sz64
> 0x100000000ULL
) {
266 res
->flags
|= IORESOURCE_UNSET
| IORESOURCE_DISABLED
;
269 pci_err(dev
, "reg 0x%x: can't handle BAR larger than 4GB (size %#010llx)\n",
270 pos
, (unsigned long long)sz64
);
274 if ((sizeof(pci_bus_addr_t
) < 8) && l
) {
275 /* Above 32-bit boundary; try to reallocate */
276 res
->flags
|= IORESOURCE_UNSET
;
279 pci_info(dev
, "reg 0x%x: can't handle BAR above 4GB (bus address %#010llx)\n",
280 pos
, (unsigned long long)l64
);
286 region
.end
= l64
+ sz64
- 1;
288 pcibios_bus_to_resource(dev
->bus
, res
, ®ion
);
289 pcibios_resource_to_bus(dev
->bus
, &inverted_region
, res
);
292 * If "A" is a BAR value (a bus address), "bus_to_resource(A)" is
293 * the corresponding resource address (the physical address used by
294 * the CPU. Converting that resource address back to a bus address
295 * should yield the original BAR value:
297 * resource_to_bus(bus_to_resource(A)) == A
299 * If it doesn't, CPU accesses to "bus_to_resource(A)" will not
300 * be claimed by the device.
302 if (inverted_region
.start
!= region
.start
) {
303 res
->flags
|= IORESOURCE_UNSET
;
305 res
->end
= region
.end
- region
.start
;
306 pci_info(dev
, "reg 0x%x: initial BAR value %#010llx invalid\n",
307 pos
, (unsigned long long)region
.start
);
317 pci_info(dev
, "reg 0x%x: %pR\n", pos
, res
);
319 return (res
->flags
& IORESOURCE_MEM_64
) ? 1 : 0;
322 static void pci_read_bases(struct pci_dev
*dev
, unsigned int howmany
, int rom
)
324 unsigned int pos
, reg
;
326 if (dev
->non_compliant_bars
)
329 /* Per PCIe r4.0, sec 9.3.4.1.11, the VF BARs are all RO Zero */
333 for (pos
= 0; pos
< howmany
; pos
++) {
334 struct resource
*res
= &dev
->resource
[pos
];
335 reg
= PCI_BASE_ADDRESS_0
+ (pos
<< 2);
336 pos
+= __pci_read_base(dev
, pci_bar_unknown
, res
, reg
);
340 struct resource
*res
= &dev
->resource
[PCI_ROM_RESOURCE
];
341 dev
->rom_base_reg
= rom
;
342 res
->flags
= IORESOURCE_MEM
| IORESOURCE_PREFETCH
|
343 IORESOURCE_READONLY
| IORESOURCE_SIZEALIGN
;
344 __pci_read_base(dev
, pci_bar_mem32
, res
, rom
);
348 static void pci_read_bridge_windows(struct pci_dev
*bridge
)
353 pci_read_config_word(bridge
, PCI_IO_BASE
, &io
);
355 pci_write_config_word(bridge
, PCI_IO_BASE
, 0xe0f0);
356 pci_read_config_word(bridge
, PCI_IO_BASE
, &io
);
357 pci_write_config_word(bridge
, PCI_IO_BASE
, 0x0);
360 bridge
->io_window
= 1;
363 * DECchip 21050 pass 2 errata: the bridge may miss an address
364 * disconnect boundary by one PCI data phase. Workaround: do not
365 * use prefetching on this device.
367 if (bridge
->vendor
== PCI_VENDOR_ID_DEC
&& bridge
->device
== 0x0001)
370 pci_read_config_dword(bridge
, PCI_PREF_MEMORY_BASE
, &pmem
);
372 pci_write_config_dword(bridge
, PCI_PREF_MEMORY_BASE
,
374 pci_read_config_dword(bridge
, PCI_PREF_MEMORY_BASE
, &pmem
);
375 pci_write_config_dword(bridge
, PCI_PREF_MEMORY_BASE
, 0x0);
380 bridge
->pref_window
= 1;
382 if ((pmem
& PCI_PREF_RANGE_TYPE_MASK
) == PCI_PREF_RANGE_TYPE_64
) {
385 * Bridge claims to have a 64-bit prefetchable memory
386 * window; verify that the upper bits are actually
389 pci_read_config_dword(bridge
, PCI_PREF_BASE_UPPER32
, &pmem
);
390 pci_write_config_dword(bridge
, PCI_PREF_BASE_UPPER32
,
392 pci_read_config_dword(bridge
, PCI_PREF_BASE_UPPER32
, &tmp
);
393 pci_write_config_dword(bridge
, PCI_PREF_BASE_UPPER32
, pmem
);
395 bridge
->pref_64_window
= 1;
399 static void pci_read_bridge_io(struct pci_bus
*child
)
401 struct pci_dev
*dev
= child
->self
;
402 u8 io_base_lo
, io_limit_lo
;
403 unsigned long io_mask
, io_granularity
, base
, limit
;
404 struct pci_bus_region region
;
405 struct resource
*res
;
407 io_mask
= PCI_IO_RANGE_MASK
;
408 io_granularity
= 0x1000;
409 if (dev
->io_window_1k
) {
410 /* Support 1K I/O space granularity */
411 io_mask
= PCI_IO_1K_RANGE_MASK
;
412 io_granularity
= 0x400;
415 res
= child
->resource
[0];
416 pci_read_config_byte(dev
, PCI_IO_BASE
, &io_base_lo
);
417 pci_read_config_byte(dev
, PCI_IO_LIMIT
, &io_limit_lo
);
418 base
= (io_base_lo
& io_mask
) << 8;
419 limit
= (io_limit_lo
& io_mask
) << 8;
421 if ((io_base_lo
& PCI_IO_RANGE_TYPE_MASK
) == PCI_IO_RANGE_TYPE_32
) {
422 u16 io_base_hi
, io_limit_hi
;
424 pci_read_config_word(dev
, PCI_IO_BASE_UPPER16
, &io_base_hi
);
425 pci_read_config_word(dev
, PCI_IO_LIMIT_UPPER16
, &io_limit_hi
);
426 base
|= ((unsigned long) io_base_hi
<< 16);
427 limit
|= ((unsigned long) io_limit_hi
<< 16);
431 res
->flags
= (io_base_lo
& PCI_IO_RANGE_TYPE_MASK
) | IORESOURCE_IO
;
433 region
.end
= limit
+ io_granularity
- 1;
434 pcibios_bus_to_resource(dev
->bus
, res
, ®ion
);
435 pci_info(dev
, " bridge window %pR\n", res
);
439 static void pci_read_bridge_mmio(struct pci_bus
*child
)
441 struct pci_dev
*dev
= child
->self
;
442 u16 mem_base_lo
, mem_limit_lo
;
443 unsigned long base
, limit
;
444 struct pci_bus_region region
;
445 struct resource
*res
;
447 res
= child
->resource
[1];
448 pci_read_config_word(dev
, PCI_MEMORY_BASE
, &mem_base_lo
);
449 pci_read_config_word(dev
, PCI_MEMORY_LIMIT
, &mem_limit_lo
);
450 base
= ((unsigned long) mem_base_lo
& PCI_MEMORY_RANGE_MASK
) << 16;
451 limit
= ((unsigned long) mem_limit_lo
& PCI_MEMORY_RANGE_MASK
) << 16;
453 res
->flags
= (mem_base_lo
& PCI_MEMORY_RANGE_TYPE_MASK
) | IORESOURCE_MEM
;
455 region
.end
= limit
+ 0xfffff;
456 pcibios_bus_to_resource(dev
->bus
, res
, ®ion
);
457 pci_info(dev
, " bridge window %pR\n", res
);
461 static void pci_read_bridge_mmio_pref(struct pci_bus
*child
)
463 struct pci_dev
*dev
= child
->self
;
464 u16 mem_base_lo
, mem_limit_lo
;
466 pci_bus_addr_t base
, limit
;
467 struct pci_bus_region region
;
468 struct resource
*res
;
470 res
= child
->resource
[2];
471 pci_read_config_word(dev
, PCI_PREF_MEMORY_BASE
, &mem_base_lo
);
472 pci_read_config_word(dev
, PCI_PREF_MEMORY_LIMIT
, &mem_limit_lo
);
473 base64
= (mem_base_lo
& PCI_PREF_RANGE_MASK
) << 16;
474 limit64
= (mem_limit_lo
& PCI_PREF_RANGE_MASK
) << 16;
476 if ((mem_base_lo
& PCI_PREF_RANGE_TYPE_MASK
) == PCI_PREF_RANGE_TYPE_64
) {
477 u32 mem_base_hi
, mem_limit_hi
;
479 pci_read_config_dword(dev
, PCI_PREF_BASE_UPPER32
, &mem_base_hi
);
480 pci_read_config_dword(dev
, PCI_PREF_LIMIT_UPPER32
, &mem_limit_hi
);
483 * Some bridges set the base > limit by default, and some
484 * (broken) BIOSes do not initialize them. If we find
485 * this, just assume they are not being used.
487 if (mem_base_hi
<= mem_limit_hi
) {
488 base64
|= (u64
) mem_base_hi
<< 32;
489 limit64
|= (u64
) mem_limit_hi
<< 32;
493 base
= (pci_bus_addr_t
) base64
;
494 limit
= (pci_bus_addr_t
) limit64
;
496 if (base
!= base64
) {
497 pci_err(dev
, "can't handle bridge window above 4GB (bus address %#010llx)\n",
498 (unsigned long long) base64
);
503 res
->flags
= (mem_base_lo
& PCI_PREF_RANGE_TYPE_MASK
) |
504 IORESOURCE_MEM
| IORESOURCE_PREFETCH
;
505 if (res
->flags
& PCI_PREF_RANGE_TYPE_64
)
506 res
->flags
|= IORESOURCE_MEM_64
;
508 region
.end
= limit
+ 0xfffff;
509 pcibios_bus_to_resource(dev
->bus
, res
, ®ion
);
510 pci_info(dev
, " bridge window %pR\n", res
);
514 void pci_read_bridge_bases(struct pci_bus
*child
)
516 struct pci_dev
*dev
= child
->self
;
517 struct resource
*res
;
520 if (pci_is_root_bus(child
)) /* It's a host bus, nothing to read */
523 pci_info(dev
, "PCI bridge to %pR%s\n",
525 dev
->transparent
? " (subtractive decode)" : "");
527 pci_bus_remove_resources(child
);
528 for (i
= 0; i
< PCI_BRIDGE_RESOURCE_NUM
; i
++)
529 child
->resource
[i
] = &dev
->resource
[PCI_BRIDGE_RESOURCES
+i
];
531 pci_read_bridge_io(child
);
532 pci_read_bridge_mmio(child
);
533 pci_read_bridge_mmio_pref(child
);
535 if (dev
->transparent
) {
536 pci_bus_for_each_resource(child
->parent
, res
, i
) {
537 if (res
&& res
->flags
) {
538 pci_bus_add_resource(child
, res
,
539 PCI_SUBTRACTIVE_DECODE
);
540 pci_info(dev
, " bridge window %pR (subtractive decode)\n",
547 static struct pci_bus
*pci_alloc_bus(struct pci_bus
*parent
)
551 b
= kzalloc(sizeof(*b
), GFP_KERNEL
);
555 INIT_LIST_HEAD(&b
->node
);
556 INIT_LIST_HEAD(&b
->children
);
557 INIT_LIST_HEAD(&b
->devices
);
558 INIT_LIST_HEAD(&b
->slots
);
559 INIT_LIST_HEAD(&b
->resources
);
560 b
->max_bus_speed
= PCI_SPEED_UNKNOWN
;
561 b
->cur_bus_speed
= PCI_SPEED_UNKNOWN
;
562 #ifdef CONFIG_PCI_DOMAINS_GENERIC
564 b
->domain_nr
= parent
->domain_nr
;
569 static void pci_release_host_bridge_dev(struct device
*dev
)
571 struct pci_host_bridge
*bridge
= to_pci_host_bridge(dev
);
573 if (bridge
->release_fn
)
574 bridge
->release_fn(bridge
);
576 pci_free_resource_list(&bridge
->windows
);
577 pci_free_resource_list(&bridge
->dma_ranges
);
581 static void pci_init_host_bridge(struct pci_host_bridge
*bridge
)
583 INIT_LIST_HEAD(&bridge
->windows
);
584 INIT_LIST_HEAD(&bridge
->dma_ranges
);
587 * We assume we can manage these PCIe features. Some systems may
588 * reserve these for use by the platform itself, e.g., an ACPI BIOS
589 * may implement its own AER handling and use _OSC to prevent the
590 * OS from interfering.
592 bridge
->native_aer
= 1;
593 bridge
->native_pcie_hotplug
= 1;
594 bridge
->native_shpc_hotplug
= 1;
595 bridge
->native_pme
= 1;
596 bridge
->native_ltr
= 1;
597 bridge
->native_dpc
= 1;
599 device_initialize(&bridge
->dev
);
602 struct pci_host_bridge
*pci_alloc_host_bridge(size_t priv
)
604 struct pci_host_bridge
*bridge
;
606 bridge
= kzalloc(sizeof(*bridge
) + priv
, GFP_KERNEL
);
610 pci_init_host_bridge(bridge
);
611 bridge
->dev
.release
= pci_release_host_bridge_dev
;
615 EXPORT_SYMBOL(pci_alloc_host_bridge
);
617 static void devm_pci_alloc_host_bridge_release(void *data
)
619 pci_free_host_bridge(data
);
622 struct pci_host_bridge
*devm_pci_alloc_host_bridge(struct device
*dev
,
626 struct pci_host_bridge
*bridge
;
628 bridge
= pci_alloc_host_bridge(priv
);
632 bridge
->dev
.parent
= dev
;
634 ret
= devm_add_action_or_reset(dev
, devm_pci_alloc_host_bridge_release
,
639 ret
= devm_of_pci_bridge_init(dev
, bridge
);
645 EXPORT_SYMBOL(devm_pci_alloc_host_bridge
);
647 void pci_free_host_bridge(struct pci_host_bridge
*bridge
)
649 put_device(&bridge
->dev
);
651 EXPORT_SYMBOL(pci_free_host_bridge
);
653 /* Indexed by PCI_X_SSTATUS_FREQ (secondary bus mode and frequency) */
654 static const unsigned char pcix_bus_speed
[] = {
655 PCI_SPEED_UNKNOWN
, /* 0 */
656 PCI_SPEED_66MHz_PCIX
, /* 1 */
657 PCI_SPEED_100MHz_PCIX
, /* 2 */
658 PCI_SPEED_133MHz_PCIX
, /* 3 */
659 PCI_SPEED_UNKNOWN
, /* 4 */
660 PCI_SPEED_66MHz_PCIX_ECC
, /* 5 */
661 PCI_SPEED_100MHz_PCIX_ECC
, /* 6 */
662 PCI_SPEED_133MHz_PCIX_ECC
, /* 7 */
663 PCI_SPEED_UNKNOWN
, /* 8 */
664 PCI_SPEED_66MHz_PCIX_266
, /* 9 */
665 PCI_SPEED_100MHz_PCIX_266
, /* A */
666 PCI_SPEED_133MHz_PCIX_266
, /* B */
667 PCI_SPEED_UNKNOWN
, /* C */
668 PCI_SPEED_66MHz_PCIX_533
, /* D */
669 PCI_SPEED_100MHz_PCIX_533
, /* E */
670 PCI_SPEED_133MHz_PCIX_533
/* F */
673 /* Indexed by PCI_EXP_LNKCAP_SLS, PCI_EXP_LNKSTA_CLS */
674 const unsigned char pcie_link_speed
[] = {
675 PCI_SPEED_UNKNOWN
, /* 0 */
676 PCIE_SPEED_2_5GT
, /* 1 */
677 PCIE_SPEED_5_0GT
, /* 2 */
678 PCIE_SPEED_8_0GT
, /* 3 */
679 PCIE_SPEED_16_0GT
, /* 4 */
680 PCIE_SPEED_32_0GT
, /* 5 */
681 PCIE_SPEED_64_0GT
, /* 6 */
682 PCI_SPEED_UNKNOWN
, /* 7 */
683 PCI_SPEED_UNKNOWN
, /* 8 */
684 PCI_SPEED_UNKNOWN
, /* 9 */
685 PCI_SPEED_UNKNOWN
, /* A */
686 PCI_SPEED_UNKNOWN
, /* B */
687 PCI_SPEED_UNKNOWN
, /* C */
688 PCI_SPEED_UNKNOWN
, /* D */
689 PCI_SPEED_UNKNOWN
, /* E */
690 PCI_SPEED_UNKNOWN
/* F */
692 EXPORT_SYMBOL_GPL(pcie_link_speed
);
694 const char *pci_speed_string(enum pci_bus_speed speed
)
696 /* Indexed by the pci_bus_speed enum */
697 static const char *speed_strings
[] = {
698 "33 MHz PCI", /* 0x00 */
699 "66 MHz PCI", /* 0x01 */
700 "66 MHz PCI-X", /* 0x02 */
701 "100 MHz PCI-X", /* 0x03 */
702 "133 MHz PCI-X", /* 0x04 */
707 "66 MHz PCI-X 266", /* 0x09 */
708 "100 MHz PCI-X 266", /* 0x0a */
709 "133 MHz PCI-X 266", /* 0x0b */
710 "Unknown AGP", /* 0x0c */
715 "66 MHz PCI-X 533", /* 0x11 */
716 "100 MHz PCI-X 533", /* 0x12 */
717 "133 MHz PCI-X 533", /* 0x13 */
718 "2.5 GT/s PCIe", /* 0x14 */
719 "5.0 GT/s PCIe", /* 0x15 */
720 "8.0 GT/s PCIe", /* 0x16 */
721 "16.0 GT/s PCIe", /* 0x17 */
722 "32.0 GT/s PCIe", /* 0x18 */
723 "64.0 GT/s PCIe", /* 0x19 */
726 if (speed
< ARRAY_SIZE(speed_strings
))
727 return speed_strings
[speed
];
730 EXPORT_SYMBOL_GPL(pci_speed_string
);
732 void pcie_update_link_speed(struct pci_bus
*bus
, u16 linksta
)
734 bus
->cur_bus_speed
= pcie_link_speed
[linksta
& PCI_EXP_LNKSTA_CLS
];
736 EXPORT_SYMBOL_GPL(pcie_update_link_speed
);
738 static unsigned char agp_speeds
[] = {
746 static enum pci_bus_speed
agp_speed(int agp3
, int agpstat
)
752 else if (agpstat
& 2)
754 else if (agpstat
& 1)
766 return agp_speeds
[index
];
769 static void pci_set_bus_speed(struct pci_bus
*bus
)
771 struct pci_dev
*bridge
= bus
->self
;
774 pos
= pci_find_capability(bridge
, PCI_CAP_ID_AGP
);
776 pos
= pci_find_capability(bridge
, PCI_CAP_ID_AGP3
);
780 pci_read_config_dword(bridge
, pos
+ PCI_AGP_STATUS
, &agpstat
);
781 bus
->max_bus_speed
= agp_speed(agpstat
& 8, agpstat
& 7);
783 pci_read_config_dword(bridge
, pos
+ PCI_AGP_COMMAND
, &agpcmd
);
784 bus
->cur_bus_speed
= agp_speed(agpstat
& 8, agpcmd
& 7);
787 pos
= pci_find_capability(bridge
, PCI_CAP_ID_PCIX
);
790 enum pci_bus_speed max
;
792 pci_read_config_word(bridge
, pos
+ PCI_X_BRIDGE_SSTATUS
,
795 if (status
& PCI_X_SSTATUS_533MHZ
) {
796 max
= PCI_SPEED_133MHz_PCIX_533
;
797 } else if (status
& PCI_X_SSTATUS_266MHZ
) {
798 max
= PCI_SPEED_133MHz_PCIX_266
;
799 } else if (status
& PCI_X_SSTATUS_133MHZ
) {
800 if ((status
& PCI_X_SSTATUS_VERS
) == PCI_X_SSTATUS_V2
)
801 max
= PCI_SPEED_133MHz_PCIX_ECC
;
803 max
= PCI_SPEED_133MHz_PCIX
;
805 max
= PCI_SPEED_66MHz_PCIX
;
808 bus
->max_bus_speed
= max
;
809 bus
->cur_bus_speed
= pcix_bus_speed
[
810 (status
& PCI_X_SSTATUS_FREQ
) >> 6];
815 if (pci_is_pcie(bridge
)) {
819 pcie_capability_read_dword(bridge
, PCI_EXP_LNKCAP
, &linkcap
);
820 bus
->max_bus_speed
= pcie_link_speed
[linkcap
& PCI_EXP_LNKCAP_SLS
];
821 bridge
->link_active_reporting
= !!(linkcap
& PCI_EXP_LNKCAP_DLLLARC
);
823 pcie_capability_read_word(bridge
, PCI_EXP_LNKSTA
, &linksta
);
824 pcie_update_link_speed(bus
, linksta
);
828 static struct irq_domain
*pci_host_bridge_msi_domain(struct pci_bus
*bus
)
830 struct irq_domain
*d
;
833 * Any firmware interface that can resolve the msi_domain
834 * should be called from here.
836 d
= pci_host_bridge_of_msi_domain(bus
);
838 d
= pci_host_bridge_acpi_msi_domain(bus
);
840 #ifdef CONFIG_PCI_MSI_IRQ_DOMAIN
842 * If no IRQ domain was found via the OF tree, try looking it up
843 * directly through the fwnode_handle.
846 struct fwnode_handle
*fwnode
= pci_root_bus_fwnode(bus
);
849 d
= irq_find_matching_fwnode(fwnode
,
857 static void pci_set_bus_msi_domain(struct pci_bus
*bus
)
859 struct irq_domain
*d
;
863 * The bus can be a root bus, a subordinate bus, or a virtual bus
864 * created by an SR-IOV device. Walk up to the first bridge device
865 * found or derive the domain from the host bridge.
867 for (b
= bus
, d
= NULL
; !d
&& !pci_is_root_bus(b
); b
= b
->parent
) {
869 d
= dev_get_msi_domain(&b
->self
->dev
);
873 d
= pci_host_bridge_msi_domain(b
);
875 dev_set_msi_domain(&bus
->dev
, d
);
878 static int res_cmp(void *priv
, const struct list_head
*a
,
879 const struct list_head
*b
)
881 struct resource_entry
*entry1
, *entry2
;
883 entry1
= container_of(a
, struct resource_entry
, node
);
884 entry2
= container_of(b
, struct resource_entry
, node
);
886 if (entry1
->res
->flags
!= entry2
->res
->flags
)
887 return entry1
->res
->flags
> entry2
->res
->flags
;
889 if (entry1
->offset
!= entry2
->offset
)
890 return entry1
->offset
> entry2
->offset
;
892 return entry1
->res
->start
> entry2
->res
->start
;
895 static int pci_register_host_bridge(struct pci_host_bridge
*bridge
)
897 struct device
*parent
= bridge
->dev
.parent
;
898 struct resource_entry
*window
, *next
, *n
;
899 struct pci_bus
*bus
, *b
;
900 resource_size_t offset
, next_offset
;
901 LIST_HEAD(resources
);
902 struct resource
*res
, *next_res
;
907 bus
= pci_alloc_bus(NULL
);
913 /* Temporarily move resources off the list */
914 list_splice_init(&bridge
->windows
, &resources
);
915 bus
->sysdata
= bridge
->sysdata
;
916 bus
->ops
= bridge
->ops
;
917 bus
->number
= bus
->busn_res
.start
= bridge
->busnr
;
918 #ifdef CONFIG_PCI_DOMAINS_GENERIC
919 bus
->domain_nr
= pci_bus_find_domain_nr(bus
, parent
);
922 b
= pci_find_bus(pci_domain_nr(bus
), bridge
->busnr
);
924 /* Ignore it if we already got here via a different bridge */
925 dev_dbg(&b
->dev
, "bus already known\n");
930 dev_set_name(&bridge
->dev
, "pci%04x:%02x", pci_domain_nr(bus
),
933 err
= pcibios_root_bridge_prepare(bridge
);
937 err
= device_add(&bridge
->dev
);
939 put_device(&bridge
->dev
);
942 bus
->bridge
= get_device(&bridge
->dev
);
943 device_enable_async_suspend(bus
->bridge
);
944 pci_set_bus_of_node(bus
);
945 pci_set_bus_msi_domain(bus
);
946 if (bridge
->msi_domain
&& !dev_get_msi_domain(&bus
->dev
) &&
947 !pci_host_of_has_msi_map(parent
))
948 bus
->bus_flags
|= PCI_BUS_FLAGS_NO_MSI
;
951 set_dev_node(bus
->bridge
, pcibus_to_node(bus
));
953 bus
->dev
.class = &pcibus_class
;
954 bus
->dev
.parent
= bus
->bridge
;
956 dev_set_name(&bus
->dev
, "%04x:%02x", pci_domain_nr(bus
), bus
->number
);
957 name
= dev_name(&bus
->dev
);
959 err
= device_register(&bus
->dev
);
963 pcibios_add_bus(bus
);
965 if (bus
->ops
->add_bus
) {
966 err
= bus
->ops
->add_bus(bus
);
967 if (WARN_ON(err
< 0))
968 dev_err(&bus
->dev
, "failed to add bus: %d\n", err
);
971 /* Create legacy_io and legacy_mem files for this bus */
972 pci_create_legacy_files(bus
);
975 dev_info(parent
, "PCI host bridge to bus %s\n", name
);
977 pr_info("PCI host bridge to bus %s\n", name
);
979 if (nr_node_ids
> 1 && pcibus_to_node(bus
) == NUMA_NO_NODE
)
980 dev_warn(&bus
->dev
, "Unknown NUMA node; performance will be reduced\n");
982 /* Sort and coalesce contiguous windows */
983 list_sort(NULL
, &resources
, res_cmp
);
984 resource_list_for_each_entry_safe(window
, n
, &resources
) {
985 if (list_is_last(&window
->node
, &resources
))
988 next
= list_next_entry(window
, node
);
989 offset
= window
->offset
;
991 next_offset
= next
->offset
;
992 next_res
= next
->res
;
994 if (res
->flags
!= next_res
->flags
|| offset
!= next_offset
)
997 if (res
->end
+ 1 == next_res
->start
) {
998 next_res
->start
= res
->start
;
999 res
->flags
= res
->start
= res
->end
= 0;
1003 /* Add initial resources to the bus */
1004 resource_list_for_each_entry_safe(window
, n
, &resources
) {
1005 offset
= window
->offset
;
1010 list_move_tail(&window
->node
, &bridge
->windows
);
1012 if (res
->flags
& IORESOURCE_BUS
)
1013 pci_bus_insert_busn_res(bus
, bus
->number
, res
->end
);
1015 pci_bus_add_resource(bus
, res
, 0);
1018 if (resource_type(res
) == IORESOURCE_IO
)
1019 fmt
= " (bus address [%#06llx-%#06llx])";
1021 fmt
= " (bus address [%#010llx-%#010llx])";
1023 snprintf(addr
, sizeof(addr
), fmt
,
1024 (unsigned long long)(res
->start
- offset
),
1025 (unsigned long long)(res
->end
- offset
));
1029 dev_info(&bus
->dev
, "root bus resource %pR%s\n", res
, addr
);
1032 down_write(&pci_bus_sem
);
1033 list_add_tail(&bus
->node
, &pci_root_buses
);
1034 up_write(&pci_bus_sem
);
1039 put_device(&bridge
->dev
);
1040 device_del(&bridge
->dev
);
1047 static bool pci_bridge_child_ext_cfg_accessible(struct pci_dev
*bridge
)
1053 * If extended config space isn't accessible on a bridge's primary
1054 * bus, we certainly can't access it on the secondary bus.
1056 if (bridge
->bus
->bus_flags
& PCI_BUS_FLAGS_NO_EXTCFG
)
1060 * PCIe Root Ports and switch ports are PCIe on both sides, so if
1061 * extended config space is accessible on the primary, it's also
1062 * accessible on the secondary.
1064 if (pci_is_pcie(bridge
) &&
1065 (pci_pcie_type(bridge
) == PCI_EXP_TYPE_ROOT_PORT
||
1066 pci_pcie_type(bridge
) == PCI_EXP_TYPE_UPSTREAM
||
1067 pci_pcie_type(bridge
) == PCI_EXP_TYPE_DOWNSTREAM
))
1071 * For the other bridge types:
1072 * - PCI-to-PCI bridges
1073 * - PCIe-to-PCI/PCI-X forward bridges
1074 * - PCI/PCI-X-to-PCIe reverse bridges
1075 * extended config space on the secondary side is only accessible
1076 * if the bridge supports PCI-X Mode 2.
1078 pos
= pci_find_capability(bridge
, PCI_CAP_ID_PCIX
);
1082 pci_read_config_dword(bridge
, pos
+ PCI_X_STATUS
, &status
);
1083 return status
& (PCI_X_STATUS_266MHZ
| PCI_X_STATUS_533MHZ
);
1086 static struct pci_bus
*pci_alloc_child_bus(struct pci_bus
*parent
,
1087 struct pci_dev
*bridge
, int busnr
)
1089 struct pci_bus
*child
;
1090 struct pci_host_bridge
*host
;
1094 /* Allocate a new bus and inherit stuff from the parent */
1095 child
= pci_alloc_bus(parent
);
1099 child
->parent
= parent
;
1100 child
->sysdata
= parent
->sysdata
;
1101 child
->bus_flags
= parent
->bus_flags
;
1103 host
= pci_find_host_bridge(parent
);
1104 if (host
->child_ops
)
1105 child
->ops
= host
->child_ops
;
1107 child
->ops
= parent
->ops
;
1110 * Initialize some portions of the bus device, but don't register
1111 * it now as the parent is not properly set up yet.
1113 child
->dev
.class = &pcibus_class
;
1114 dev_set_name(&child
->dev
, "%04x:%02x", pci_domain_nr(child
), busnr
);
1116 /* Set up the primary, secondary and subordinate bus numbers */
1117 child
->number
= child
->busn_res
.start
= busnr
;
1118 child
->primary
= parent
->busn_res
.start
;
1119 child
->busn_res
.end
= 0xff;
1122 child
->dev
.parent
= parent
->bridge
;
1126 child
->self
= bridge
;
1127 child
->bridge
= get_device(&bridge
->dev
);
1128 child
->dev
.parent
= child
->bridge
;
1129 pci_set_bus_of_node(child
);
1130 pci_set_bus_speed(child
);
1133 * Check whether extended config space is accessible on the child
1134 * bus. Note that we currently assume it is always accessible on
1137 if (!pci_bridge_child_ext_cfg_accessible(bridge
)) {
1138 child
->bus_flags
|= PCI_BUS_FLAGS_NO_EXTCFG
;
1139 pci_info(child
, "extended config space not accessible\n");
1142 /* Set up default resource pointers and names */
1143 for (i
= 0; i
< PCI_BRIDGE_RESOURCE_NUM
; i
++) {
1144 child
->resource
[i
] = &bridge
->resource
[PCI_BRIDGE_RESOURCES
+i
];
1145 child
->resource
[i
]->name
= child
->name
;
1147 bridge
->subordinate
= child
;
1150 pci_set_bus_msi_domain(child
);
1151 ret
= device_register(&child
->dev
);
1154 pcibios_add_bus(child
);
1156 if (child
->ops
->add_bus
) {
1157 ret
= child
->ops
->add_bus(child
);
1158 if (WARN_ON(ret
< 0))
1159 dev_err(&child
->dev
, "failed to add bus: %d\n", ret
);
1162 /* Create legacy_io and legacy_mem files for this bus */
1163 pci_create_legacy_files(child
);
1168 struct pci_bus
*pci_add_new_bus(struct pci_bus
*parent
, struct pci_dev
*dev
,
1171 struct pci_bus
*child
;
1173 child
= pci_alloc_child_bus(parent
, dev
, busnr
);
1175 down_write(&pci_bus_sem
);
1176 list_add_tail(&child
->node
, &parent
->children
);
1177 up_write(&pci_bus_sem
);
1181 EXPORT_SYMBOL(pci_add_new_bus
);
1183 static void pci_enable_crs(struct pci_dev
*pdev
)
1187 /* Enable CRS Software Visibility if supported */
1188 pcie_capability_read_word(pdev
, PCI_EXP_RTCAP
, &root_cap
);
1189 if (root_cap
& PCI_EXP_RTCAP_CRSVIS
)
1190 pcie_capability_set_word(pdev
, PCI_EXP_RTCTL
,
1191 PCI_EXP_RTCTL_CRSSVE
);
1194 static unsigned int pci_scan_child_bus_extend(struct pci_bus
*bus
,
1195 unsigned int available_buses
);
1197 * pci_ea_fixed_busnrs() - Read fixed Secondary and Subordinate bus
1198 * numbers from EA capability.
1200 * @sec: updated with secondary bus number from EA
1201 * @sub: updated with subordinate bus number from EA
1203 * If @dev is a bridge with EA capability that specifies valid secondary
1204 * and subordinate bus numbers, return true with the bus numbers in @sec
1205 * and @sub. Otherwise return false.
1207 static bool pci_ea_fixed_busnrs(struct pci_dev
*dev
, u8
*sec
, u8
*sub
)
1213 if (dev
->hdr_type
!= PCI_HEADER_TYPE_BRIDGE
)
1216 /* find PCI EA capability in list */
1217 ea
= pci_find_capability(dev
, PCI_CAP_ID_EA
);
1221 offset
= ea
+ PCI_EA_FIRST_ENT
;
1222 pci_read_config_dword(dev
, offset
, &dw
);
1223 ea_sec
= dw
& PCI_EA_SEC_BUS_MASK
;
1224 ea_sub
= (dw
& PCI_EA_SUB_BUS_MASK
) >> PCI_EA_SUB_BUS_SHIFT
;
1225 if (ea_sec
== 0 || ea_sub
< ea_sec
)
1234 * pci_scan_bridge_extend() - Scan buses behind a bridge
1235 * @bus: Parent bus the bridge is on
1236 * @dev: Bridge itself
1237 * @max: Starting subordinate number of buses behind this bridge
1238 * @available_buses: Total number of buses available for this bridge and
1239 * the devices below. After the minimal bus space has
1240 * been allocated the remaining buses will be
1241 * distributed equally between hotplug-capable bridges.
1242 * @pass: Either %0 (scan already configured bridges) or %1 (scan bridges
1243 * that need to be reconfigured.
1245 * If it's a bridge, configure it and scan the bus behind it.
1246 * For CardBus bridges, we don't scan behind as the devices will
1247 * be handled by the bridge driver itself.
1249 * We need to process bridges in two passes -- first we scan those
1250 * already configured by the BIOS and after we are done with all of
1251 * them, we proceed to assigning numbers to the remaining buses in
1252 * order to avoid overlaps between old and new bus numbers.
1254 * Return: New subordinate number covering all buses behind this bridge.
1256 static int pci_scan_bridge_extend(struct pci_bus
*bus
, struct pci_dev
*dev
,
1257 int max
, unsigned int available_buses
,
1260 struct pci_bus
*child
;
1261 int is_cardbus
= (dev
->hdr_type
== PCI_HEADER_TYPE_CARDBUS
);
1262 u32 buses
, i
, j
= 0;
1264 u8 primary
, secondary
, subordinate
;
1267 u8 fixed_sec
, fixed_sub
;
1271 * Make sure the bridge is powered on to be able to access config
1272 * space of devices below it.
1274 pm_runtime_get_sync(&dev
->dev
);
1276 pci_read_config_dword(dev
, PCI_PRIMARY_BUS
, &buses
);
1277 primary
= buses
& 0xFF;
1278 secondary
= (buses
>> 8) & 0xFF;
1279 subordinate
= (buses
>> 16) & 0xFF;
1281 pci_dbg(dev
, "scanning [bus %02x-%02x] behind bridge, pass %d\n",
1282 secondary
, subordinate
, pass
);
1284 if (!primary
&& (primary
!= bus
->number
) && secondary
&& subordinate
) {
1285 pci_warn(dev
, "Primary bus is hard wired to 0\n");
1286 primary
= bus
->number
;
1289 /* Check if setup is sensible at all */
1291 (primary
!= bus
->number
|| secondary
<= bus
->number
||
1292 secondary
> subordinate
)) {
1293 pci_info(dev
, "bridge configuration invalid ([bus %02x-%02x]), reconfiguring\n",
1294 secondary
, subordinate
);
1299 * Disable Master-Abort Mode during probing to avoid reporting of
1300 * bus errors in some architectures.
1302 pci_read_config_word(dev
, PCI_BRIDGE_CONTROL
, &bctl
);
1303 pci_write_config_word(dev
, PCI_BRIDGE_CONTROL
,
1304 bctl
& ~PCI_BRIDGE_CTL_MASTER_ABORT
);
1306 pci_enable_crs(dev
);
1308 if ((secondary
|| subordinate
) && !pcibios_assign_all_busses() &&
1309 !is_cardbus
&& !broken
) {
1313 * Bus already configured by firmware, process it in the
1314 * first pass and just note the configuration.
1320 * The bus might already exist for two reasons: Either we
1321 * are rescanning the bus or the bus is reachable through
1322 * more than one bridge. The second case can happen with
1323 * the i450NX chipset.
1325 child
= pci_find_bus(pci_domain_nr(bus
), secondary
);
1327 child
= pci_add_new_bus(bus
, dev
, secondary
);
1330 child
->primary
= primary
;
1331 pci_bus_insert_busn_res(child
, secondary
, subordinate
);
1332 child
->bridge_ctl
= bctl
;
1335 cmax
= pci_scan_child_bus(child
);
1336 if (cmax
> subordinate
)
1337 pci_warn(dev
, "bridge has subordinate %02x but max busn %02x\n",
1340 /* Subordinate should equal child->busn_res.end */
1341 if (subordinate
> max
)
1346 * We need to assign a number to this bus which we always
1347 * do in the second pass.
1350 if (pcibios_assign_all_busses() || broken
|| is_cardbus
)
1353 * Temporarily disable forwarding of the
1354 * configuration cycles on all bridges in
1355 * this bus segment to avoid possible
1356 * conflicts in the second pass between two
1357 * bridges programmed with overlapping bus
1360 pci_write_config_dword(dev
, PCI_PRIMARY_BUS
,
1366 pci_write_config_word(dev
, PCI_STATUS
, 0xffff);
1368 /* Read bus numbers from EA Capability (if present) */
1369 fixed_buses
= pci_ea_fixed_busnrs(dev
, &fixed_sec
, &fixed_sub
);
1371 next_busnr
= fixed_sec
;
1373 next_busnr
= max
+ 1;
1376 * Prevent assigning a bus number that already exists.
1377 * This can happen when a bridge is hot-plugged, so in this
1378 * case we only re-scan this bus.
1380 child
= pci_find_bus(pci_domain_nr(bus
), next_busnr
);
1382 child
= pci_add_new_bus(bus
, dev
, next_busnr
);
1385 pci_bus_insert_busn_res(child
, next_busnr
,
1389 if (available_buses
)
1392 buses
= (buses
& 0xff000000)
1393 | ((unsigned int)(child
->primary
) << 0)
1394 | ((unsigned int)(child
->busn_res
.start
) << 8)
1395 | ((unsigned int)(child
->busn_res
.end
) << 16);
1398 * yenta.c forces a secondary latency timer of 176.
1399 * Copy that behaviour here.
1402 buses
&= ~0xff000000;
1403 buses
|= CARDBUS_LATENCY_TIMER
<< 24;
1406 /* We need to blast all three values with a single write */
1407 pci_write_config_dword(dev
, PCI_PRIMARY_BUS
, buses
);
1410 child
->bridge_ctl
= bctl
;
1411 max
= pci_scan_child_bus_extend(child
, available_buses
);
1415 * For CardBus bridges, we leave 4 bus numbers as
1416 * cards with a PCI-to-PCI bridge can be inserted
1419 for (i
= 0; i
< CARDBUS_RESERVE_BUSNR
; i
++) {
1420 struct pci_bus
*parent
= bus
;
1421 if (pci_find_bus(pci_domain_nr(bus
),
1424 while (parent
->parent
) {
1425 if ((!pcibios_assign_all_busses()) &&
1426 (parent
->busn_res
.end
> max
) &&
1427 (parent
->busn_res
.end
<= max
+i
)) {
1430 parent
= parent
->parent
;
1435 * Often, there are two CardBus
1436 * bridges -- try to leave one
1437 * valid bus number for each one.
1447 * Set subordinate bus number to its real value.
1448 * If fixed subordinate bus number exists from EA
1449 * capability then use it.
1453 pci_bus_update_busn_res_end(child
, max
);
1454 pci_write_config_byte(dev
, PCI_SUBORDINATE_BUS
, max
);
1457 sprintf(child
->name
,
1458 (is_cardbus
? "PCI CardBus %04x:%02x" : "PCI Bus %04x:%02x"),
1459 pci_domain_nr(bus
), child
->number
);
1461 /* Check that all devices are accessible */
1462 while (bus
->parent
) {
1463 if ((child
->busn_res
.end
> bus
->busn_res
.end
) ||
1464 (child
->number
> bus
->busn_res
.end
) ||
1465 (child
->number
< bus
->number
) ||
1466 (child
->busn_res
.end
< bus
->number
)) {
1467 dev_info(&dev
->dev
, "devices behind bridge are unusable because %pR cannot be assigned for them\n",
1475 pci_write_config_word(dev
, PCI_BRIDGE_CONTROL
, bctl
);
1477 pm_runtime_put(&dev
->dev
);
1483 * pci_scan_bridge() - Scan buses behind a bridge
1484 * @bus: Parent bus the bridge is on
1485 * @dev: Bridge itself
1486 * @max: Starting subordinate number of buses behind this bridge
1487 * @pass: Either %0 (scan already configured bridges) or %1 (scan bridges
1488 * that need to be reconfigured.
1490 * If it's a bridge, configure it and scan the bus behind it.
1491 * For CardBus bridges, we don't scan behind as the devices will
1492 * be handled by the bridge driver itself.
1494 * We need to process bridges in two passes -- first we scan those
1495 * already configured by the BIOS and after we are done with all of
1496 * them, we proceed to assigning numbers to the remaining buses in
1497 * order to avoid overlaps between old and new bus numbers.
1499 * Return: New subordinate number covering all buses behind this bridge.
1501 int pci_scan_bridge(struct pci_bus
*bus
, struct pci_dev
*dev
, int max
, int pass
)
1503 return pci_scan_bridge_extend(bus
, dev
, max
, 0, pass
);
1505 EXPORT_SYMBOL(pci_scan_bridge
);
1508 * Read interrupt line and base address registers.
1509 * The architecture-dependent code can tweak these, of course.
1511 static void pci_read_irq(struct pci_dev
*dev
)
1515 /* VFs are not allowed to use INTx, so skip the config reads */
1516 if (dev
->is_virtfn
) {
1522 pci_read_config_byte(dev
, PCI_INTERRUPT_PIN
, &irq
);
1525 pci_read_config_byte(dev
, PCI_INTERRUPT_LINE
, &irq
);
1529 void set_pcie_port_type(struct pci_dev
*pdev
)
1534 struct pci_dev
*parent
;
1536 pos
= pci_find_capability(pdev
, PCI_CAP_ID_EXP
);
1540 pdev
->pcie_cap
= pos
;
1541 pci_read_config_word(pdev
, pos
+ PCI_EXP_FLAGS
, ®16
);
1542 pdev
->pcie_flags_reg
= reg16
;
1543 pci_read_config_word(pdev
, pos
+ PCI_EXP_DEVCAP
, ®16
);
1544 pdev
->pcie_mpss
= reg16
& PCI_EXP_DEVCAP_PAYLOAD
;
1546 parent
= pci_upstream_bridge(pdev
);
1551 * Some systems do not identify their upstream/downstream ports
1552 * correctly so detect impossible configurations here and correct
1553 * the port type accordingly.
1555 type
= pci_pcie_type(pdev
);
1556 if (type
== PCI_EXP_TYPE_DOWNSTREAM
) {
1558 * If pdev claims to be downstream port but the parent
1559 * device is also downstream port assume pdev is actually
1562 if (pcie_downstream_port(parent
)) {
1563 pci_info(pdev
, "claims to be downstream port but is acting as upstream port, correcting type\n");
1564 pdev
->pcie_flags_reg
&= ~PCI_EXP_FLAGS_TYPE
;
1565 pdev
->pcie_flags_reg
|= PCI_EXP_TYPE_UPSTREAM
;
1567 } else if (type
== PCI_EXP_TYPE_UPSTREAM
) {
1569 * If pdev claims to be upstream port but the parent
1570 * device is also upstream port assume pdev is actually
1573 if (pci_pcie_type(parent
) == PCI_EXP_TYPE_UPSTREAM
) {
1574 pci_info(pdev
, "claims to be upstream port but is acting as downstream port, correcting type\n");
1575 pdev
->pcie_flags_reg
&= ~PCI_EXP_FLAGS_TYPE
;
1576 pdev
->pcie_flags_reg
|= PCI_EXP_TYPE_DOWNSTREAM
;
1581 void set_pcie_hotplug_bridge(struct pci_dev
*pdev
)
1585 pcie_capability_read_dword(pdev
, PCI_EXP_SLTCAP
, ®32
);
1586 if (reg32
& PCI_EXP_SLTCAP_HPC
)
1587 pdev
->is_hotplug_bridge
= 1;
1590 static void set_pcie_thunderbolt(struct pci_dev
*dev
)
1595 while ((vsec
= pci_find_next_ext_capability(dev
, vsec
,
1596 PCI_EXT_CAP_ID_VNDR
))) {
1597 pci_read_config_dword(dev
, vsec
+ PCI_VNDR_HEADER
, &header
);
1599 /* Is the device part of a Thunderbolt controller? */
1600 if (dev
->vendor
== PCI_VENDOR_ID_INTEL
&&
1601 PCI_VNDR_HEADER_ID(header
) == PCI_VSEC_ID_INTEL_TBT
) {
1602 dev
->is_thunderbolt
= 1;
1608 static void set_pcie_untrusted(struct pci_dev
*dev
)
1610 struct pci_dev
*parent
;
1613 * If the upstream bridge is untrusted we treat this device
1614 * untrusted as well.
1616 parent
= pci_upstream_bridge(dev
);
1617 if (parent
&& (parent
->untrusted
|| parent
->external_facing
))
1618 dev
->untrusted
= true;
1621 static void pci_set_removable(struct pci_dev
*dev
)
1623 struct pci_dev
*parent
= pci_upstream_bridge(dev
);
1626 * We (only) consider everything downstream from an external_facing
1627 * device to be removable by the user. We're mainly concerned with
1628 * consumer platforms with user accessible thunderbolt ports that are
1629 * vulnerable to DMA attacks, and we expect those ports to be marked by
1630 * the firmware as external_facing. Devices in traditional hotplug
1631 * slots can technically be removed, but the expectation is that unless
1632 * the port is marked with external_facing, such devices are less
1633 * accessible to user / may not be removed by end user, and thus not
1634 * exposed as "removable" to userspace.
1637 (parent
->external_facing
|| dev_is_removable(&parent
->dev
)))
1638 dev_set_removable(&dev
->dev
, DEVICE_REMOVABLE
);
1642 * pci_ext_cfg_is_aliased - Is ext config space just an alias of std config?
1645 * PCI Express to PCI/PCI-X Bridge Specification, rev 1.0, 4.1.4 says that
1646 * when forwarding a type1 configuration request the bridge must check that
1647 * the extended register address field is zero. The bridge is not permitted
1648 * to forward the transactions and must handle it as an Unsupported Request.
1649 * Some bridges do not follow this rule and simply drop the extended register
1650 * bits, resulting in the standard config space being aliased, every 256
1651 * bytes across the entire configuration space. Test for this condition by
1652 * comparing the first dword of each potential alias to the vendor/device ID.
1654 * ASM1083/1085 PCIe-to-PCI Reversible Bridge (1b21:1080, rev 01 & 03)
1655 * AMD/ATI SBx00 PCI to PCI Bridge (1002:4384, rev 40)
1657 static bool pci_ext_cfg_is_aliased(struct pci_dev
*dev
)
1659 #ifdef CONFIG_PCI_QUIRKS
1663 pci_read_config_dword(dev
, PCI_VENDOR_ID
, &header
);
1665 for (pos
= PCI_CFG_SPACE_SIZE
;
1666 pos
< PCI_CFG_SPACE_EXP_SIZE
; pos
+= PCI_CFG_SPACE_SIZE
) {
1667 if (pci_read_config_dword(dev
, pos
, &tmp
) != PCIBIOS_SUCCESSFUL
1679 * pci_cfg_space_size_ext - Get the configuration space size of the PCI device
1682 * Regular PCI devices have 256 bytes, but PCI-X 2 and PCI Express devices
1683 * have 4096 bytes. Even if the device is capable, that doesn't mean we can
1684 * access it. Maybe we don't have a way to generate extended config space
1685 * accesses, or the device is behind a reverse Express bridge. So we try
1686 * reading the dword at 0x100 which must either be 0 or a valid extended
1687 * capability header.
1689 static int pci_cfg_space_size_ext(struct pci_dev
*dev
)
1692 int pos
= PCI_CFG_SPACE_SIZE
;
1694 if (pci_read_config_dword(dev
, pos
, &status
) != PCIBIOS_SUCCESSFUL
)
1695 return PCI_CFG_SPACE_SIZE
;
1696 if (status
== 0xffffffff || pci_ext_cfg_is_aliased(dev
))
1697 return PCI_CFG_SPACE_SIZE
;
1699 return PCI_CFG_SPACE_EXP_SIZE
;
1702 int pci_cfg_space_size(struct pci_dev
*dev
)
1708 #ifdef CONFIG_PCI_IOV
1710 * Per the SR-IOV specification (rev 1.1, sec 3.5), VFs are required to
1711 * implement a PCIe capability and therefore must implement extended
1712 * config space. We can skip the NO_EXTCFG test below and the
1713 * reachability/aliasing test in pci_cfg_space_size_ext() by virtue of
1714 * the fact that the SR-IOV capability on the PF resides in extended
1715 * config space and must be accessible and non-aliased to have enabled
1716 * support for this VF. This is a micro performance optimization for
1717 * systems supporting many VFs.
1720 return PCI_CFG_SPACE_EXP_SIZE
;
1723 if (dev
->bus
->bus_flags
& PCI_BUS_FLAGS_NO_EXTCFG
)
1724 return PCI_CFG_SPACE_SIZE
;
1726 class = dev
->class >> 8;
1727 if (class == PCI_CLASS_BRIDGE_HOST
)
1728 return pci_cfg_space_size_ext(dev
);
1730 if (pci_is_pcie(dev
))
1731 return pci_cfg_space_size_ext(dev
);
1733 pos
= pci_find_capability(dev
, PCI_CAP_ID_PCIX
);
1735 return PCI_CFG_SPACE_SIZE
;
1737 pci_read_config_dword(dev
, pos
+ PCI_X_STATUS
, &status
);
1738 if (status
& (PCI_X_STATUS_266MHZ
| PCI_X_STATUS_533MHZ
))
1739 return pci_cfg_space_size_ext(dev
);
1741 return PCI_CFG_SPACE_SIZE
;
1744 static u32
pci_class(struct pci_dev
*dev
)
1748 #ifdef CONFIG_PCI_IOV
1750 return dev
->physfn
->sriov
->class;
1752 pci_read_config_dword(dev
, PCI_CLASS_REVISION
, &class);
1756 static void pci_subsystem_ids(struct pci_dev
*dev
, u16
*vendor
, u16
*device
)
1758 #ifdef CONFIG_PCI_IOV
1759 if (dev
->is_virtfn
) {
1760 *vendor
= dev
->physfn
->sriov
->subsystem_vendor
;
1761 *device
= dev
->physfn
->sriov
->subsystem_device
;
1765 pci_read_config_word(dev
, PCI_SUBSYSTEM_VENDOR_ID
, vendor
);
1766 pci_read_config_word(dev
, PCI_SUBSYSTEM_ID
, device
);
1769 static u8
pci_hdr_type(struct pci_dev
*dev
)
1773 #ifdef CONFIG_PCI_IOV
1775 return dev
->physfn
->sriov
->hdr_type
;
1777 pci_read_config_byte(dev
, PCI_HEADER_TYPE
, &hdr_type
);
1781 #define LEGACY_IO_RESOURCE (IORESOURCE_IO | IORESOURCE_PCI_FIXED)
1784 * pci_intx_mask_broken - Test PCI_COMMAND_INTX_DISABLE writability
1787 * Test whether PCI_COMMAND_INTX_DISABLE is writable for @dev. Check this
1788 * at enumeration-time to avoid modifying PCI_COMMAND at run-time.
1790 static int pci_intx_mask_broken(struct pci_dev
*dev
)
1792 u16 orig
, toggle
, new;
1794 pci_read_config_word(dev
, PCI_COMMAND
, &orig
);
1795 toggle
= orig
^ PCI_COMMAND_INTX_DISABLE
;
1796 pci_write_config_word(dev
, PCI_COMMAND
, toggle
);
1797 pci_read_config_word(dev
, PCI_COMMAND
, &new);
1799 pci_write_config_word(dev
, PCI_COMMAND
, orig
);
1802 * PCI_COMMAND_INTX_DISABLE was reserved and read-only prior to PCI
1803 * r2.3, so strictly speaking, a device is not *broken* if it's not
1804 * writable. But we'll live with the misnomer for now.
1811 static void early_dump_pci_device(struct pci_dev
*pdev
)
1816 pci_info(pdev
, "config space:\n");
1818 for (i
= 0; i
< 256; i
+= 4)
1819 pci_read_config_dword(pdev
, i
, &value
[i
/ 4]);
1821 print_hex_dump(KERN_INFO
, "", DUMP_PREFIX_OFFSET
, 16, 1,
1826 * pci_setup_device - Fill in class and map information of a device
1827 * @dev: the device structure to fill
1829 * Initialize the device structure with information about the device's
1830 * vendor,class,memory and IO-space addresses, IRQ lines etc.
1831 * Called at initialisation of the PCI subsystem and by CardBus services.
1832 * Returns 0 on success and negative if unknown type of device (not normal,
1833 * bridge or CardBus).
1835 int pci_setup_device(struct pci_dev
*dev
)
1841 struct pci_bus_region region
;
1842 struct resource
*res
;
1844 hdr_type
= pci_hdr_type(dev
);
1846 dev
->sysdata
= dev
->bus
->sysdata
;
1847 dev
->dev
.parent
= dev
->bus
->bridge
;
1848 dev
->dev
.bus
= &pci_bus_type
;
1849 dev
->hdr_type
= hdr_type
& 0x7f;
1850 dev
->multifunction
= !!(hdr_type
& 0x80);
1851 dev
->error_state
= pci_channel_io_normal
;
1852 set_pcie_port_type(dev
);
1854 pci_dev_assign_slot(dev
);
1857 * Assume 32-bit PCI; let 64-bit PCI cards (which are far rarer)
1858 * set this higher, assuming the system even supports it.
1860 dev
->dma_mask
= 0xffffffff;
1862 dev_set_name(&dev
->dev
, "%04x:%02x:%02x.%d", pci_domain_nr(dev
->bus
),
1863 dev
->bus
->number
, PCI_SLOT(dev
->devfn
),
1864 PCI_FUNC(dev
->devfn
));
1866 class = pci_class(dev
);
1868 dev
->revision
= class & 0xff;
1869 dev
->class = class >> 8; /* upper 3 bytes */
1872 early_dump_pci_device(dev
);
1874 /* Need to have dev->class ready */
1875 dev
->cfg_size
= pci_cfg_space_size(dev
);
1877 /* Need to have dev->cfg_size ready */
1878 set_pcie_thunderbolt(dev
);
1880 set_pcie_untrusted(dev
);
1882 /* "Unknown power state" */
1883 dev
->current_state
= PCI_UNKNOWN
;
1885 /* Early fixups, before probing the BARs */
1886 pci_fixup_device(pci_fixup_early
, dev
);
1888 pci_set_removable(dev
);
1890 pci_info(dev
, "[%04x:%04x] type %02x class %#08x\n",
1891 dev
->vendor
, dev
->device
, dev
->hdr_type
, dev
->class);
1893 /* Device class may be changed after fixup */
1894 class = dev
->class >> 8;
1896 if (dev
->non_compliant_bars
&& !dev
->mmio_always_on
) {
1897 pci_read_config_word(dev
, PCI_COMMAND
, &cmd
);
1898 if (cmd
& (PCI_COMMAND_IO
| PCI_COMMAND_MEMORY
)) {
1899 pci_info(dev
, "device has non-compliant BARs; disabling IO/MEM decoding\n");
1900 cmd
&= ~PCI_COMMAND_IO
;
1901 cmd
&= ~PCI_COMMAND_MEMORY
;
1902 pci_write_config_word(dev
, PCI_COMMAND
, cmd
);
1906 dev
->broken_intx_masking
= pci_intx_mask_broken(dev
);
1908 switch (dev
->hdr_type
) { /* header type */
1909 case PCI_HEADER_TYPE_NORMAL
: /* standard header */
1910 if (class == PCI_CLASS_BRIDGE_PCI
)
1913 pci_read_bases(dev
, 6, PCI_ROM_ADDRESS
);
1915 pci_subsystem_ids(dev
, &dev
->subsystem_vendor
, &dev
->subsystem_device
);
1918 * Do the ugly legacy mode stuff here rather than broken chip
1919 * quirk code. Legacy mode ATA controllers have fixed
1920 * addresses. These are not always echoed in BAR0-3, and
1921 * BAR0-3 in a few cases contain junk!
1923 if (class == PCI_CLASS_STORAGE_IDE
) {
1925 pci_read_config_byte(dev
, PCI_CLASS_PROG
, &progif
);
1926 if ((progif
& 1) == 0) {
1927 region
.start
= 0x1F0;
1929 res
= &dev
->resource
[0];
1930 res
->flags
= LEGACY_IO_RESOURCE
;
1931 pcibios_bus_to_resource(dev
->bus
, res
, ®ion
);
1932 pci_info(dev
, "legacy IDE quirk: reg 0x10: %pR\n",
1934 region
.start
= 0x3F6;
1936 res
= &dev
->resource
[1];
1937 res
->flags
= LEGACY_IO_RESOURCE
;
1938 pcibios_bus_to_resource(dev
->bus
, res
, ®ion
);
1939 pci_info(dev
, "legacy IDE quirk: reg 0x14: %pR\n",
1942 if ((progif
& 4) == 0) {
1943 region
.start
= 0x170;
1945 res
= &dev
->resource
[2];
1946 res
->flags
= LEGACY_IO_RESOURCE
;
1947 pcibios_bus_to_resource(dev
->bus
, res
, ®ion
);
1948 pci_info(dev
, "legacy IDE quirk: reg 0x18: %pR\n",
1950 region
.start
= 0x376;
1952 res
= &dev
->resource
[3];
1953 res
->flags
= LEGACY_IO_RESOURCE
;
1954 pcibios_bus_to_resource(dev
->bus
, res
, ®ion
);
1955 pci_info(dev
, "legacy IDE quirk: reg 0x1c: %pR\n",
1961 case PCI_HEADER_TYPE_BRIDGE
: /* bridge header */
1963 * The PCI-to-PCI bridge spec requires that subtractive
1964 * decoding (i.e. transparent) bridge must have programming
1965 * interface code of 0x01.
1968 dev
->transparent
= ((dev
->class & 0xff) == 1);
1969 pci_read_bases(dev
, 2, PCI_ROM_ADDRESS1
);
1970 pci_read_bridge_windows(dev
);
1971 set_pcie_hotplug_bridge(dev
);
1972 pos
= pci_find_capability(dev
, PCI_CAP_ID_SSVID
);
1974 pci_read_config_word(dev
, pos
+ PCI_SSVID_VENDOR_ID
, &dev
->subsystem_vendor
);
1975 pci_read_config_word(dev
, pos
+ PCI_SSVID_DEVICE_ID
, &dev
->subsystem_device
);
1979 case PCI_HEADER_TYPE_CARDBUS
: /* CardBus bridge header */
1980 if (class != PCI_CLASS_BRIDGE_CARDBUS
)
1983 pci_read_bases(dev
, 1, 0);
1984 pci_read_config_word(dev
, PCI_CB_SUBSYSTEM_VENDOR_ID
, &dev
->subsystem_vendor
);
1985 pci_read_config_word(dev
, PCI_CB_SUBSYSTEM_ID
, &dev
->subsystem_device
);
1988 default: /* unknown header */
1989 pci_err(dev
, "unknown header type %02x, ignoring device\n",
1994 pci_err(dev
, "ignoring class %#08x (doesn't match header type %02x)\n",
1995 dev
->class, dev
->hdr_type
);
1996 dev
->class = PCI_CLASS_NOT_DEFINED
<< 8;
1999 /* We found a fine healthy device, go go go... */
2003 static void pci_configure_mps(struct pci_dev
*dev
)
2005 struct pci_dev
*bridge
= pci_upstream_bridge(dev
);
2006 int mps
, mpss
, p_mps
, rc
;
2008 if (!pci_is_pcie(dev
))
2011 /* MPS and MRRS fields are of type 'RsvdP' for VFs, short-circuit out */
2016 * For Root Complex Integrated Endpoints, program the maximum
2017 * supported value unless limited by the PCIE_BUS_PEER2PEER case.
2019 if (pci_pcie_type(dev
) == PCI_EXP_TYPE_RC_END
) {
2020 if (pcie_bus_config
== PCIE_BUS_PEER2PEER
)
2023 mps
= 128 << dev
->pcie_mpss
;
2024 rc
= pcie_set_mps(dev
, mps
);
2026 pci_warn(dev
, "can't set Max Payload Size to %d; if necessary, use \"pci=pcie_bus_safe\" and report a bug\n",
2032 if (!bridge
|| !pci_is_pcie(bridge
))
2035 mps
= pcie_get_mps(dev
);
2036 p_mps
= pcie_get_mps(bridge
);
2041 if (pcie_bus_config
== PCIE_BUS_TUNE_OFF
) {
2042 pci_warn(dev
, "Max Payload Size %d, but upstream %s set to %d; if necessary, use \"pci=pcie_bus_safe\" and report a bug\n",
2043 mps
, pci_name(bridge
), p_mps
);
2048 * Fancier MPS configuration is done later by
2049 * pcie_bus_configure_settings()
2051 if (pcie_bus_config
!= PCIE_BUS_DEFAULT
)
2054 mpss
= 128 << dev
->pcie_mpss
;
2055 if (mpss
< p_mps
&& pci_pcie_type(bridge
) == PCI_EXP_TYPE_ROOT_PORT
) {
2056 pcie_set_mps(bridge
, mpss
);
2057 pci_info(dev
, "Upstream bridge's Max Payload Size set to %d (was %d, max %d)\n",
2058 mpss
, p_mps
, 128 << bridge
->pcie_mpss
);
2059 p_mps
= pcie_get_mps(bridge
);
2062 rc
= pcie_set_mps(dev
, p_mps
);
2064 pci_warn(dev
, "can't set Max Payload Size to %d; if necessary, use \"pci=pcie_bus_safe\" and report a bug\n",
2069 pci_info(dev
, "Max Payload Size set to %d (was %d, max %d)\n",
2073 int pci_configure_extended_tags(struct pci_dev
*dev
, void *ign
)
2075 struct pci_host_bridge
*host
;
2080 if (!pci_is_pcie(dev
))
2083 ret
= pcie_capability_read_dword(dev
, PCI_EXP_DEVCAP
, &cap
);
2087 if (!(cap
& PCI_EXP_DEVCAP_EXT_TAG
))
2090 ret
= pcie_capability_read_word(dev
, PCI_EXP_DEVCTL
, &ctl
);
2094 host
= pci_find_host_bridge(dev
->bus
);
2099 * If some device in the hierarchy doesn't handle Extended Tags
2100 * correctly, make sure they're disabled.
2102 if (host
->no_ext_tags
) {
2103 if (ctl
& PCI_EXP_DEVCTL_EXT_TAG
) {
2104 pci_info(dev
, "disabling Extended Tags\n");
2105 pcie_capability_clear_word(dev
, PCI_EXP_DEVCTL
,
2106 PCI_EXP_DEVCTL_EXT_TAG
);
2111 if (!(ctl
& PCI_EXP_DEVCTL_EXT_TAG
)) {
2112 pci_info(dev
, "enabling Extended Tags\n");
2113 pcie_capability_set_word(dev
, PCI_EXP_DEVCTL
,
2114 PCI_EXP_DEVCTL_EXT_TAG
);
2120 * pcie_relaxed_ordering_enabled - Probe for PCIe relaxed ordering enable
2121 * @dev: PCI device to query
2123 * Returns true if the device has enabled relaxed ordering attribute.
2125 bool pcie_relaxed_ordering_enabled(struct pci_dev
*dev
)
2129 pcie_capability_read_word(dev
, PCI_EXP_DEVCTL
, &v
);
2131 return !!(v
& PCI_EXP_DEVCTL_RELAX_EN
);
2133 EXPORT_SYMBOL(pcie_relaxed_ordering_enabled
);
2135 static void pci_configure_relaxed_ordering(struct pci_dev
*dev
)
2137 struct pci_dev
*root
;
2139 /* PCI_EXP_DEVICE_RELAX_EN is RsvdP in VFs */
2143 if (!pcie_relaxed_ordering_enabled(dev
))
2147 * For now, we only deal with Relaxed Ordering issues with Root
2148 * Ports. Peer-to-Peer DMA is another can of worms.
2150 root
= pcie_find_root_port(dev
);
2154 if (root
->dev_flags
& PCI_DEV_FLAGS_NO_RELAXED_ORDERING
) {
2155 pcie_capability_clear_word(dev
, PCI_EXP_DEVCTL
,
2156 PCI_EXP_DEVCTL_RELAX_EN
);
2157 pci_info(dev
, "Relaxed Ordering disabled because the Root Port didn't support it\n");
2161 static void pci_configure_ltr(struct pci_dev
*dev
)
2163 #ifdef CONFIG_PCIEASPM
2164 struct pci_host_bridge
*host
= pci_find_host_bridge(dev
->bus
);
2165 struct pci_dev
*bridge
;
2168 if (!pci_is_pcie(dev
))
2171 /* Read L1 PM substate capabilities */
2172 dev
->l1ss
= pci_find_ext_capability(dev
, PCI_EXT_CAP_ID_L1SS
);
2174 pcie_capability_read_dword(dev
, PCI_EXP_DEVCAP2
, &cap
);
2175 if (!(cap
& PCI_EXP_DEVCAP2_LTR
))
2178 pcie_capability_read_dword(dev
, PCI_EXP_DEVCTL2
, &ctl
);
2179 if (ctl
& PCI_EXP_DEVCTL2_LTR_EN
) {
2180 if (pci_pcie_type(dev
) == PCI_EXP_TYPE_ROOT_PORT
) {
2185 bridge
= pci_upstream_bridge(dev
);
2186 if (bridge
&& bridge
->ltr_path
)
2192 if (!host
->native_ltr
)
2196 * Software must not enable LTR in an Endpoint unless the Root
2197 * Complex and all intermediate Switches indicate support for LTR.
2198 * PCIe r4.0, sec 6.18.
2200 if (pci_pcie_type(dev
) == PCI_EXP_TYPE_ROOT_PORT
||
2201 ((bridge
= pci_upstream_bridge(dev
)) &&
2202 bridge
->ltr_path
)) {
2203 pcie_capability_set_word(dev
, PCI_EXP_DEVCTL2
,
2204 PCI_EXP_DEVCTL2_LTR_EN
);
2210 static void pci_configure_eetlp_prefix(struct pci_dev
*dev
)
2212 #ifdef CONFIG_PCI_PASID
2213 struct pci_dev
*bridge
;
2217 if (!pci_is_pcie(dev
))
2220 pcie_capability_read_dword(dev
, PCI_EXP_DEVCAP2
, &cap
);
2221 if (!(cap
& PCI_EXP_DEVCAP2_EE_PREFIX
))
2224 pcie_type
= pci_pcie_type(dev
);
2225 if (pcie_type
== PCI_EXP_TYPE_ROOT_PORT
||
2226 pcie_type
== PCI_EXP_TYPE_RC_END
)
2227 dev
->eetlp_prefix_path
= 1;
2229 bridge
= pci_upstream_bridge(dev
);
2230 if (bridge
&& bridge
->eetlp_prefix_path
)
2231 dev
->eetlp_prefix_path
= 1;
2236 static void pci_configure_serr(struct pci_dev
*dev
)
2240 if (dev
->hdr_type
== PCI_HEADER_TYPE_BRIDGE
) {
2243 * A bridge will not forward ERR_ messages coming from an
2244 * endpoint unless SERR# forwarding is enabled.
2246 pci_read_config_word(dev
, PCI_BRIDGE_CONTROL
, &control
);
2247 if (!(control
& PCI_BRIDGE_CTL_SERR
)) {
2248 control
|= PCI_BRIDGE_CTL_SERR
;
2249 pci_write_config_word(dev
, PCI_BRIDGE_CONTROL
, control
);
2254 static void pci_configure_device(struct pci_dev
*dev
)
2256 pci_configure_mps(dev
);
2257 pci_configure_extended_tags(dev
, NULL
);
2258 pci_configure_relaxed_ordering(dev
);
2259 pci_configure_ltr(dev
);
2260 pci_configure_eetlp_prefix(dev
);
2261 pci_configure_serr(dev
);
2263 pci_acpi_program_hp_params(dev
);
2266 static void pci_release_capabilities(struct pci_dev
*dev
)
2270 pci_vpd_release(dev
);
2271 pci_iov_release(dev
);
2272 pci_free_cap_save_buffers(dev
);
2276 * pci_release_dev - Free a PCI device structure when all users of it are
2278 * @dev: device that's been disconnected
2280 * Will be called only by the device core when all users of this PCI device are
2283 static void pci_release_dev(struct device
*dev
)
2285 struct pci_dev
*pci_dev
;
2287 pci_dev
= to_pci_dev(dev
);
2288 pci_release_capabilities(pci_dev
);
2289 pci_release_of_node(pci_dev
);
2290 pcibios_release_device(pci_dev
);
2291 pci_bus_put(pci_dev
->bus
);
2292 kfree(pci_dev
->driver_override
);
2293 bitmap_free(pci_dev
->dma_alias_mask
);
2294 dev_dbg(dev
, "device released\n");
2298 struct pci_dev
*pci_alloc_dev(struct pci_bus
*bus
)
2300 struct pci_dev
*dev
;
2302 dev
= kzalloc(sizeof(struct pci_dev
), GFP_KERNEL
);
2306 INIT_LIST_HEAD(&dev
->bus_list
);
2307 dev
->dev
.type
= &pci_dev_type
;
2308 dev
->bus
= pci_bus_get(bus
);
2312 EXPORT_SYMBOL(pci_alloc_dev
);
2314 static bool pci_bus_crs_vendor_id(u32 l
)
2316 return (l
& 0xffff) == 0x0001;
2319 static bool pci_bus_wait_crs(struct pci_bus
*bus
, int devfn
, u32
*l
,
2324 if (!pci_bus_crs_vendor_id(*l
))
2325 return true; /* not a CRS completion */
2328 return false; /* CRS, but caller doesn't want to wait */
2331 * We got the reserved Vendor ID that indicates a completion with
2332 * Configuration Request Retry Status (CRS). Retry until we get a
2333 * valid Vendor ID or we time out.
2335 while (pci_bus_crs_vendor_id(*l
)) {
2336 if (delay
> timeout
) {
2337 pr_warn("pci %04x:%02x:%02x.%d: not ready after %dms; giving up\n",
2338 pci_domain_nr(bus
), bus
->number
,
2339 PCI_SLOT(devfn
), PCI_FUNC(devfn
), delay
- 1);
2344 pr_info("pci %04x:%02x:%02x.%d: not ready after %dms; waiting\n",
2345 pci_domain_nr(bus
), bus
->number
,
2346 PCI_SLOT(devfn
), PCI_FUNC(devfn
), delay
- 1);
2351 if (pci_bus_read_config_dword(bus
, devfn
, PCI_VENDOR_ID
, l
))
2356 pr_info("pci %04x:%02x:%02x.%d: ready after %dms\n",
2357 pci_domain_nr(bus
), bus
->number
,
2358 PCI_SLOT(devfn
), PCI_FUNC(devfn
), delay
- 1);
2363 bool pci_bus_generic_read_dev_vendor_id(struct pci_bus
*bus
, int devfn
, u32
*l
,
2366 if (pci_bus_read_config_dword(bus
, devfn
, PCI_VENDOR_ID
, l
))
2369 /* Some broken boards return 0 or ~0 if a slot is empty: */
2370 if (*l
== 0xffffffff || *l
== 0x00000000 ||
2371 *l
== 0x0000ffff || *l
== 0xffff0000)
2374 if (pci_bus_crs_vendor_id(*l
))
2375 return pci_bus_wait_crs(bus
, devfn
, l
, timeout
);
2380 bool pci_bus_read_dev_vendor_id(struct pci_bus
*bus
, int devfn
, u32
*l
,
2383 #ifdef CONFIG_PCI_QUIRKS
2384 struct pci_dev
*bridge
= bus
->self
;
2387 * Certain IDT switches have an issue where they improperly trigger
2388 * ACS Source Validation errors on completions for config reads.
2390 if (bridge
&& bridge
->vendor
== PCI_VENDOR_ID_IDT
&&
2391 bridge
->device
== 0x80b5)
2392 return pci_idt_bus_quirk(bus
, devfn
, l
, timeout
);
2395 return pci_bus_generic_read_dev_vendor_id(bus
, devfn
, l
, timeout
);
2397 EXPORT_SYMBOL(pci_bus_read_dev_vendor_id
);
2400 * Read the config data for a PCI device, sanity-check it,
2401 * and fill in the dev structure.
2403 static struct pci_dev
*pci_scan_device(struct pci_bus
*bus
, int devfn
)
2405 struct pci_dev
*dev
;
2408 if (!pci_bus_read_dev_vendor_id(bus
, devfn
, &l
, 60*1000))
2411 dev
= pci_alloc_dev(bus
);
2416 dev
->vendor
= l
& 0xffff;
2417 dev
->device
= (l
>> 16) & 0xffff;
2419 pci_set_of_node(dev
);
2421 if (pci_setup_device(dev
)) {
2422 pci_release_of_node(dev
);
2423 pci_bus_put(dev
->bus
);
2431 void pcie_report_downtraining(struct pci_dev
*dev
)
2433 if (!pci_is_pcie(dev
))
2436 /* Look from the device up to avoid downstream ports with no devices */
2437 if ((pci_pcie_type(dev
) != PCI_EXP_TYPE_ENDPOINT
) &&
2438 (pci_pcie_type(dev
) != PCI_EXP_TYPE_LEG_END
) &&
2439 (pci_pcie_type(dev
) != PCI_EXP_TYPE_UPSTREAM
))
2442 /* Multi-function PCIe devices share the same link/status */
2443 if (PCI_FUNC(dev
->devfn
) != 0 || dev
->is_virtfn
)
2446 /* Print link status only if the device is constrained by the fabric */
2447 __pcie_print_link_status(dev
, false);
2450 static void pci_init_capabilities(struct pci_dev
*dev
)
2452 pci_ea_init(dev
); /* Enhanced Allocation */
2453 pci_msi_init(dev
); /* Disable MSI */
2454 pci_msix_init(dev
); /* Disable MSI-X */
2456 /* Buffers for saving PCIe and PCI-X capabilities */
2457 pci_allocate_cap_save_buffers(dev
);
2459 pci_pm_init(dev
); /* Power Management */
2460 pci_vpd_init(dev
); /* Vital Product Data */
2461 pci_configure_ari(dev
); /* Alternative Routing-ID Forwarding */
2462 pci_iov_init(dev
); /* Single Root I/O Virtualization */
2463 pci_ats_init(dev
); /* Address Translation Services */
2464 pci_pri_init(dev
); /* Page Request Interface */
2465 pci_pasid_init(dev
); /* Process Address Space ID */
2466 pci_acs_init(dev
); /* Access Control Services */
2467 pci_ptm_init(dev
); /* Precision Time Measurement */
2468 pci_aer_init(dev
); /* Advanced Error Reporting */
2469 pci_dpc_init(dev
); /* Downstream Port Containment */
2470 pci_rcec_init(dev
); /* Root Complex Event Collector */
2472 pcie_report_downtraining(dev
);
2474 if (pci_probe_reset_function(dev
) == 0)
2479 * This is the equivalent of pci_host_bridge_msi_domain() that acts on
2480 * devices. Firmware interfaces that can select the MSI domain on a
2481 * per-device basis should be called from here.
2483 static struct irq_domain
*pci_dev_msi_domain(struct pci_dev
*dev
)
2485 struct irq_domain
*d
;
2488 * If a domain has been set through the pcibios_add_device()
2489 * callback, then this is the one (platform code knows best).
2491 d
= dev_get_msi_domain(&dev
->dev
);
2496 * Let's see if we have a firmware interface able to provide
2499 d
= pci_msi_get_device_domain(dev
);
2506 static void pci_set_msi_domain(struct pci_dev
*dev
)
2508 struct irq_domain
*d
;
2511 * If the platform or firmware interfaces cannot supply a
2512 * device-specific MSI domain, then inherit the default domain
2513 * from the host bridge itself.
2515 d
= pci_dev_msi_domain(dev
);
2517 d
= dev_get_msi_domain(&dev
->bus
->dev
);
2519 dev_set_msi_domain(&dev
->dev
, d
);
2522 void pci_device_add(struct pci_dev
*dev
, struct pci_bus
*bus
)
2526 pci_configure_device(dev
);
2528 device_initialize(&dev
->dev
);
2529 dev
->dev
.release
= pci_release_dev
;
2531 set_dev_node(&dev
->dev
, pcibus_to_node(bus
));
2532 dev
->dev
.dma_mask
= &dev
->dma_mask
;
2533 dev
->dev
.dma_parms
= &dev
->dma_parms
;
2534 dev
->dev
.coherent_dma_mask
= 0xffffffffull
;
2536 dma_set_max_seg_size(&dev
->dev
, 65536);
2537 dma_set_seg_boundary(&dev
->dev
, 0xffffffff);
2539 /* Fix up broken headers */
2540 pci_fixup_device(pci_fixup_header
, dev
);
2542 pci_reassigndev_resource_alignment(dev
);
2544 dev
->state_saved
= false;
2546 pci_init_capabilities(dev
);
2549 * Add the device to our list of discovered devices
2550 * and the bus list for fixup functions, etc.
2552 down_write(&pci_bus_sem
);
2553 list_add_tail(&dev
->bus_list
, &bus
->devices
);
2554 up_write(&pci_bus_sem
);
2556 ret
= pcibios_add_device(dev
);
2559 /* Set up MSI IRQ domain */
2560 pci_set_msi_domain(dev
);
2562 /* Notifier could use PCI capabilities */
2563 dev
->match_driver
= false;
2564 ret
= device_add(&dev
->dev
);
2568 struct pci_dev
*pci_scan_single_device(struct pci_bus
*bus
, int devfn
)
2570 struct pci_dev
*dev
;
2572 dev
= pci_get_slot(bus
, devfn
);
2578 dev
= pci_scan_device(bus
, devfn
);
2582 pci_device_add(dev
, bus
);
2586 EXPORT_SYMBOL(pci_scan_single_device
);
2588 static unsigned next_fn(struct pci_bus
*bus
, struct pci_dev
*dev
, unsigned fn
)
2594 if (pci_ari_enabled(bus
)) {
2597 pos
= pci_find_ext_capability(dev
, PCI_EXT_CAP_ID_ARI
);
2601 pci_read_config_word(dev
, pos
+ PCI_ARI_CAP
, &cap
);
2602 next_fn
= PCI_ARI_CAP_NFN(cap
);
2604 return 0; /* protect against malformed list */
2609 /* dev may be NULL for non-contiguous multifunction devices */
2610 if (!dev
|| dev
->multifunction
)
2611 return (fn
+ 1) % 8;
2616 static int only_one_child(struct pci_bus
*bus
)
2618 struct pci_dev
*bridge
= bus
->self
;
2621 * Systems with unusual topologies set PCI_SCAN_ALL_PCIE_DEVS so
2622 * we scan for all possible devices, not just Device 0.
2624 if (pci_has_flag(PCI_SCAN_ALL_PCIE_DEVS
))
2628 * A PCIe Downstream Port normally leads to a Link with only Device
2629 * 0 on it (PCIe spec r3.1, sec 7.3.1). As an optimization, scan
2630 * only for Device 0 in that situation.
2632 if (bridge
&& pci_is_pcie(bridge
) && pcie_downstream_port(bridge
))
2639 * pci_scan_slot - Scan a PCI slot on a bus for devices
2640 * @bus: PCI bus to scan
2641 * @devfn: slot number to scan (must have zero function)
2643 * Scan a PCI slot on the specified PCI bus for devices, adding
2644 * discovered devices to the @bus->devices list. New devices
2645 * will not have is_added set.
2647 * Returns the number of new devices found.
2649 int pci_scan_slot(struct pci_bus
*bus
, int devfn
)
2651 unsigned fn
, nr
= 0;
2652 struct pci_dev
*dev
;
2654 if (only_one_child(bus
) && (devfn
> 0))
2655 return 0; /* Already scanned the entire slot */
2657 dev
= pci_scan_single_device(bus
, devfn
);
2660 if (!pci_dev_is_added(dev
))
2663 for (fn
= next_fn(bus
, dev
, 0); fn
> 0; fn
= next_fn(bus
, dev
, fn
)) {
2664 dev
= pci_scan_single_device(bus
, devfn
+ fn
);
2666 if (!pci_dev_is_added(dev
))
2668 dev
->multifunction
= 1;
2672 /* Only one slot has PCIe device */
2673 if (bus
->self
&& nr
)
2674 pcie_aspm_init_link_state(bus
->self
);
2678 EXPORT_SYMBOL(pci_scan_slot
);
2680 static int pcie_find_smpss(struct pci_dev
*dev
, void *data
)
2684 if (!pci_is_pcie(dev
))
2688 * We don't have a way to change MPS settings on devices that have
2689 * drivers attached. A hot-added device might support only the minimum
2690 * MPS setting (MPS=128). Therefore, if the fabric contains a bridge
2691 * where devices may be hot-added, we limit the fabric MPS to 128 so
2692 * hot-added devices will work correctly.
2694 * However, if we hot-add a device to a slot directly below a Root
2695 * Port, it's impossible for there to be other existing devices below
2696 * the port. We don't limit the MPS in this case because we can
2697 * reconfigure MPS on both the Root Port and the hot-added device,
2698 * and there are no other devices involved.
2700 * Note that this PCIE_BUS_SAFE path assumes no peer-to-peer DMA.
2702 if (dev
->is_hotplug_bridge
&&
2703 pci_pcie_type(dev
) != PCI_EXP_TYPE_ROOT_PORT
)
2706 if (*smpss
> dev
->pcie_mpss
)
2707 *smpss
= dev
->pcie_mpss
;
2712 static void pcie_write_mps(struct pci_dev
*dev
, int mps
)
2716 if (pcie_bus_config
== PCIE_BUS_PERFORMANCE
) {
2717 mps
= 128 << dev
->pcie_mpss
;
2719 if (pci_pcie_type(dev
) != PCI_EXP_TYPE_ROOT_PORT
&&
2723 * For "Performance", the assumption is made that
2724 * downstream communication will never be larger than
2725 * the MRRS. So, the MPS only needs to be configured
2726 * for the upstream communication. This being the case,
2727 * walk from the top down and set the MPS of the child
2728 * to that of the parent bus.
2730 * Configure the device MPS with the smaller of the
2731 * device MPSS or the bridge MPS (which is assumed to be
2732 * properly configured at this point to the largest
2733 * allowable MPS based on its parent bus).
2735 mps
= min(mps
, pcie_get_mps(dev
->bus
->self
));
2738 rc
= pcie_set_mps(dev
, mps
);
2740 pci_err(dev
, "Failed attempting to set the MPS\n");
2743 static void pcie_write_mrrs(struct pci_dev
*dev
)
2748 * In the "safe" case, do not configure the MRRS. There appear to be
2749 * issues with setting MRRS to 0 on a number of devices.
2751 if (pcie_bus_config
!= PCIE_BUS_PERFORMANCE
)
2755 * For max performance, the MRRS must be set to the largest supported
2756 * value. However, it cannot be configured larger than the MPS the
2757 * device or the bus can support. This should already be properly
2758 * configured by a prior call to pcie_write_mps().
2760 mrrs
= pcie_get_mps(dev
);
2763 * MRRS is a R/W register. Invalid values can be written, but a
2764 * subsequent read will verify if the value is acceptable or not.
2765 * If the MRRS value provided is not acceptable (e.g., too large),
2766 * shrink the value until it is acceptable to the HW.
2768 while (mrrs
!= pcie_get_readrq(dev
) && mrrs
>= 128) {
2769 rc
= pcie_set_readrq(dev
, mrrs
);
2773 pci_warn(dev
, "Failed attempting to set the MRRS\n");
2778 pci_err(dev
, "MRRS was unable to be configured with a safe value. If problems are experienced, try running with pci=pcie_bus_safe\n");
2781 static int pcie_bus_configure_set(struct pci_dev
*dev
, void *data
)
2785 if (!pci_is_pcie(dev
))
2788 if (pcie_bus_config
== PCIE_BUS_TUNE_OFF
||
2789 pcie_bus_config
== PCIE_BUS_DEFAULT
)
2792 mps
= 128 << *(u8
*)data
;
2793 orig_mps
= pcie_get_mps(dev
);
2795 pcie_write_mps(dev
, mps
);
2796 pcie_write_mrrs(dev
);
2798 pci_info(dev
, "Max Payload Size set to %4d/%4d (was %4d), Max Read Rq %4d\n",
2799 pcie_get_mps(dev
), 128 << dev
->pcie_mpss
,
2800 orig_mps
, pcie_get_readrq(dev
));
2806 * pcie_bus_configure_settings() requires that pci_walk_bus work in a top-down,
2807 * parents then children fashion. If this changes, then this code will not
2810 void pcie_bus_configure_settings(struct pci_bus
*bus
)
2817 if (!pci_is_pcie(bus
->self
))
2821 * FIXME - Peer to peer DMA is possible, though the endpoint would need
2822 * to be aware of the MPS of the destination. To work around this,
2823 * simply force the MPS of the entire system to the smallest possible.
2825 if (pcie_bus_config
== PCIE_BUS_PEER2PEER
)
2828 if (pcie_bus_config
== PCIE_BUS_SAFE
) {
2829 smpss
= bus
->self
->pcie_mpss
;
2831 pcie_find_smpss(bus
->self
, &smpss
);
2832 pci_walk_bus(bus
, pcie_find_smpss
, &smpss
);
2835 pcie_bus_configure_set(bus
->self
, &smpss
);
2836 pci_walk_bus(bus
, pcie_bus_configure_set
, &smpss
);
2838 EXPORT_SYMBOL_GPL(pcie_bus_configure_settings
);
2841 * Called after each bus is probed, but before its children are examined. This
2842 * is marked as __weak because multiple architectures define it.
2844 void __weak
pcibios_fixup_bus(struct pci_bus
*bus
)
2846 /* nothing to do, expected to be removed in the future */
2850 * pci_scan_child_bus_extend() - Scan devices below a bus
2851 * @bus: Bus to scan for devices
2852 * @available_buses: Total number of buses available (%0 does not try to
2853 * extend beyond the minimal)
2855 * Scans devices below @bus including subordinate buses. Returns new
2856 * subordinate number including all the found devices. Passing
2857 * @available_buses causes the remaining bus space to be distributed
2858 * equally between hotplug-capable bridges to allow future extension of the
2861 static unsigned int pci_scan_child_bus_extend(struct pci_bus
*bus
,
2862 unsigned int available_buses
)
2864 unsigned int used_buses
, normal_bridges
= 0, hotplug_bridges
= 0;
2865 unsigned int start
= bus
->busn_res
.start
;
2866 unsigned int devfn
, fn
, cmax
, max
= start
;
2867 struct pci_dev
*dev
;
2870 dev_dbg(&bus
->dev
, "scanning bus\n");
2872 /* Go find them, Rover! */
2873 for (devfn
= 0; devfn
< 256; devfn
+= 8) {
2874 nr_devs
= pci_scan_slot(bus
, devfn
);
2877 * The Jailhouse hypervisor may pass individual functions of a
2878 * multi-function device to a guest without passing function 0.
2879 * Look for them as well.
2881 if (jailhouse_paravirt() && nr_devs
== 0) {
2882 for (fn
= 1; fn
< 8; fn
++) {
2883 dev
= pci_scan_single_device(bus
, devfn
+ fn
);
2885 dev
->multifunction
= 1;
2890 /* Reserve buses for SR-IOV capability */
2891 used_buses
= pci_iov_bus_range(bus
);
2895 * After performing arch-dependent fixup of the bus, look behind
2896 * all PCI-to-PCI bridges on this bus.
2898 if (!bus
->is_added
) {
2899 dev_dbg(&bus
->dev
, "fixups for bus\n");
2900 pcibios_fixup_bus(bus
);
2905 * Calculate how many hotplug bridges and normal bridges there
2906 * are on this bus. We will distribute the additional available
2907 * buses between hotplug bridges.
2909 for_each_pci_bridge(dev
, bus
) {
2910 if (dev
->is_hotplug_bridge
)
2917 * Scan bridges that are already configured. We don't touch them
2918 * unless they are misconfigured (which will be done in the second
2921 for_each_pci_bridge(dev
, bus
) {
2923 max
= pci_scan_bridge_extend(bus
, dev
, max
, 0, 0);
2926 * Reserve one bus for each bridge now to avoid extending
2927 * hotplug bridges too much during the second scan below.
2931 used_buses
+= cmax
- max
- 1;
2934 /* Scan bridges that need to be reconfigured */
2935 for_each_pci_bridge(dev
, bus
) {
2936 unsigned int buses
= 0;
2938 if (!hotplug_bridges
&& normal_bridges
== 1) {
2941 * There is only one bridge on the bus (upstream
2942 * port) so it gets all available buses which it
2943 * can then distribute to the possible hotplug
2946 buses
= available_buses
;
2947 } else if (dev
->is_hotplug_bridge
) {
2950 * Distribute the extra buses between hotplug
2953 buses
= available_buses
/ hotplug_bridges
;
2954 buses
= min(buses
, available_buses
- used_buses
+ 1);
2958 max
= pci_scan_bridge_extend(bus
, dev
, cmax
, buses
, 1);
2959 /* One bus is already accounted so don't add it again */
2961 used_buses
+= max
- cmax
- 1;
2965 * Make sure a hotplug bridge has at least the minimum requested
2966 * number of buses but allow it to grow up to the maximum available
2967 * bus number of there is room.
2969 if (bus
->self
&& bus
->self
->is_hotplug_bridge
) {
2970 used_buses
= max_t(unsigned int, available_buses
,
2971 pci_hotplug_bus_size
- 1);
2972 if (max
- start
< used_buses
) {
2973 max
= start
+ used_buses
;
2975 /* Do not allocate more buses than we have room left */
2976 if (max
> bus
->busn_res
.end
)
2977 max
= bus
->busn_res
.end
;
2979 dev_dbg(&bus
->dev
, "%pR extended by %#02x\n",
2980 &bus
->busn_res
, max
- start
);
2985 * We've scanned the bus and so we know all about what's on
2986 * the other side of any bridges that may be on this bus plus
2989 * Return how far we've got finding sub-buses.
2991 dev_dbg(&bus
->dev
, "bus scan returning with max=%02x\n", max
);
2996 * pci_scan_child_bus() - Scan devices below a bus
2997 * @bus: Bus to scan for devices
2999 * Scans devices below @bus including subordinate buses. Returns new
3000 * subordinate number including all the found devices.
3002 unsigned int pci_scan_child_bus(struct pci_bus
*bus
)
3004 return pci_scan_child_bus_extend(bus
, 0);
3006 EXPORT_SYMBOL_GPL(pci_scan_child_bus
);
3009 * pcibios_root_bridge_prepare - Platform-specific host bridge setup
3010 * @bridge: Host bridge to set up
3012 * Default empty implementation. Replace with an architecture-specific setup
3013 * routine, if necessary.
3015 int __weak
pcibios_root_bridge_prepare(struct pci_host_bridge
*bridge
)
3020 void __weak
pcibios_add_bus(struct pci_bus
*bus
)
3024 void __weak
pcibios_remove_bus(struct pci_bus
*bus
)
3028 struct pci_bus
*pci_create_root_bus(struct device
*parent
, int bus
,
3029 struct pci_ops
*ops
, void *sysdata
, struct list_head
*resources
)
3032 struct pci_host_bridge
*bridge
;
3034 bridge
= pci_alloc_host_bridge(0);
3038 bridge
->dev
.parent
= parent
;
3040 list_splice_init(resources
, &bridge
->windows
);
3041 bridge
->sysdata
= sysdata
;
3042 bridge
->busnr
= bus
;
3045 error
= pci_register_host_bridge(bridge
);
3052 put_device(&bridge
->dev
);
3055 EXPORT_SYMBOL_GPL(pci_create_root_bus
);
3057 int pci_host_probe(struct pci_host_bridge
*bridge
)
3059 struct pci_bus
*bus
, *child
;
3062 ret
= pci_scan_root_bus_bridge(bridge
);
3064 dev_err(bridge
->dev
.parent
, "Scanning root bridge failed");
3071 * We insert PCI resources into the iomem_resource and
3072 * ioport_resource trees in either pci_bus_claim_resources()
3073 * or pci_bus_assign_resources().
3075 if (pci_has_flag(PCI_PROBE_ONLY
)) {
3076 pci_bus_claim_resources(bus
);
3078 pci_bus_size_bridges(bus
);
3079 pci_bus_assign_resources(bus
);
3081 list_for_each_entry(child
, &bus
->children
, node
)
3082 pcie_bus_configure_settings(child
);
3085 pci_bus_add_devices(bus
);
3088 EXPORT_SYMBOL_GPL(pci_host_probe
);
3090 int pci_bus_insert_busn_res(struct pci_bus
*b
, int bus
, int bus_max
)
3092 struct resource
*res
= &b
->busn_res
;
3093 struct resource
*parent_res
, *conflict
;
3097 res
->flags
= IORESOURCE_BUS
;
3099 if (!pci_is_root_bus(b
))
3100 parent_res
= &b
->parent
->busn_res
;
3102 parent_res
= get_pci_domain_busn_res(pci_domain_nr(b
));
3103 res
->flags
|= IORESOURCE_PCI_FIXED
;
3106 conflict
= request_resource_conflict(parent_res
, res
);
3110 "busn_res: can not insert %pR under %s%pR (conflicts with %s %pR)\n",
3111 res
, pci_is_root_bus(b
) ? "domain " : "",
3112 parent_res
, conflict
->name
, conflict
);
3114 return conflict
== NULL
;
3117 int pci_bus_update_busn_res_end(struct pci_bus
*b
, int bus_max
)
3119 struct resource
*res
= &b
->busn_res
;
3120 struct resource old_res
= *res
;
3121 resource_size_t size
;
3124 if (res
->start
> bus_max
)
3127 size
= bus_max
- res
->start
+ 1;
3128 ret
= adjust_resource(res
, res
->start
, size
);
3129 dev_info(&b
->dev
, "busn_res: %pR end %s updated to %02x\n",
3130 &old_res
, ret
? "can not be" : "is", bus_max
);
3132 if (!ret
&& !res
->parent
)
3133 pci_bus_insert_busn_res(b
, res
->start
, res
->end
);
3138 void pci_bus_release_busn_res(struct pci_bus
*b
)
3140 struct resource
*res
= &b
->busn_res
;
3143 if (!res
->flags
|| !res
->parent
)
3146 ret
= release_resource(res
);
3147 dev_info(&b
->dev
, "busn_res: %pR %s released\n",
3148 res
, ret
? "can not be" : "is");
3151 int pci_scan_root_bus_bridge(struct pci_host_bridge
*bridge
)
3153 struct resource_entry
*window
;
3161 resource_list_for_each_entry(window
, &bridge
->windows
)
3162 if (window
->res
->flags
& IORESOURCE_BUS
) {
3163 bridge
->busnr
= window
->res
->start
;
3168 ret
= pci_register_host_bridge(bridge
);
3173 bus
= bridge
->busnr
;
3177 "No busn resource found for root bus, will use [bus %02x-ff]\n",
3179 pci_bus_insert_busn_res(b
, bus
, 255);
3182 max
= pci_scan_child_bus(b
);
3185 pci_bus_update_busn_res_end(b
, max
);
3189 EXPORT_SYMBOL(pci_scan_root_bus_bridge
);
3191 struct pci_bus
*pci_scan_root_bus(struct device
*parent
, int bus
,
3192 struct pci_ops
*ops
, void *sysdata
, struct list_head
*resources
)
3194 struct resource_entry
*window
;
3199 resource_list_for_each_entry(window
, resources
)
3200 if (window
->res
->flags
& IORESOURCE_BUS
) {
3205 b
= pci_create_root_bus(parent
, bus
, ops
, sysdata
, resources
);
3211 "No busn resource found for root bus, will use [bus %02x-ff]\n",
3213 pci_bus_insert_busn_res(b
, bus
, 255);
3216 max
= pci_scan_child_bus(b
);
3219 pci_bus_update_busn_res_end(b
, max
);
3223 EXPORT_SYMBOL(pci_scan_root_bus
);
3225 struct pci_bus
*pci_scan_bus(int bus
, struct pci_ops
*ops
,
3228 LIST_HEAD(resources
);
3231 pci_add_resource(&resources
, &ioport_resource
);
3232 pci_add_resource(&resources
, &iomem_resource
);
3233 pci_add_resource(&resources
, &busn_resource
);
3234 b
= pci_create_root_bus(NULL
, bus
, ops
, sysdata
, &resources
);
3236 pci_scan_child_bus(b
);
3238 pci_free_resource_list(&resources
);
3242 EXPORT_SYMBOL(pci_scan_bus
);
3245 * pci_rescan_bus_bridge_resize - Scan a PCI bus for devices
3246 * @bridge: PCI bridge for the bus to scan
3248 * Scan a PCI bus and child buses for new devices, add them,
3249 * and enable them, resizing bridge mmio/io resource if necessary
3250 * and possible. The caller must ensure the child devices are already
3251 * removed for resizing to occur.
3253 * Returns the max number of subordinate bus discovered.
3255 unsigned int pci_rescan_bus_bridge_resize(struct pci_dev
*bridge
)
3258 struct pci_bus
*bus
= bridge
->subordinate
;
3260 max
= pci_scan_child_bus(bus
);
3262 pci_assign_unassigned_bridge_resources(bridge
);
3264 pci_bus_add_devices(bus
);
3270 * pci_rescan_bus - Scan a PCI bus for devices
3271 * @bus: PCI bus to scan
3273 * Scan a PCI bus and child buses for new devices, add them,
3276 * Returns the max number of subordinate bus discovered.
3278 unsigned int pci_rescan_bus(struct pci_bus
*bus
)
3282 max
= pci_scan_child_bus(bus
);
3283 pci_assign_unassigned_bus_resources(bus
);
3284 pci_bus_add_devices(bus
);
3288 EXPORT_SYMBOL_GPL(pci_rescan_bus
);
3291 * pci_rescan_bus(), pci_rescan_bus_bridge_resize() and PCI device removal
3292 * routines should always be executed under this mutex.
3294 static DEFINE_MUTEX(pci_rescan_remove_lock
);
3296 void pci_lock_rescan_remove(void)
3298 mutex_lock(&pci_rescan_remove_lock
);
3300 EXPORT_SYMBOL_GPL(pci_lock_rescan_remove
);
3302 void pci_unlock_rescan_remove(void)
3304 mutex_unlock(&pci_rescan_remove_lock
);
3306 EXPORT_SYMBOL_GPL(pci_unlock_rescan_remove
);
3308 static int __init
pci_sort_bf_cmp(const struct device
*d_a
,
3309 const struct device
*d_b
)
3311 const struct pci_dev
*a
= to_pci_dev(d_a
);
3312 const struct pci_dev
*b
= to_pci_dev(d_b
);
3314 if (pci_domain_nr(a
->bus
) < pci_domain_nr(b
->bus
)) return -1;
3315 else if (pci_domain_nr(a
->bus
) > pci_domain_nr(b
->bus
)) return 1;
3317 if (a
->bus
->number
< b
->bus
->number
) return -1;
3318 else if (a
->bus
->number
> b
->bus
->number
) return 1;
3320 if (a
->devfn
< b
->devfn
) return -1;
3321 else if (a
->devfn
> b
->devfn
) return 1;
3326 void __init
pci_sort_breadthfirst(void)
3328 bus_sort_breadthfirst(&pci_bus_type
, &pci_sort_bf_cmp
);
3331 int pci_hp_add_bridge(struct pci_dev
*dev
)
3333 struct pci_bus
*parent
= dev
->bus
;
3334 int busnr
, start
= parent
->busn_res
.start
;
3335 unsigned int available_buses
= 0;
3336 int end
= parent
->busn_res
.end
;
3338 for (busnr
= start
; busnr
<= end
; busnr
++) {
3339 if (!pci_find_bus(pci_domain_nr(parent
), busnr
))
3342 if (busnr
-- > end
) {
3343 pci_err(dev
, "No bus number available for hot-added bridge\n");
3347 /* Scan bridges that are already configured */
3348 busnr
= pci_scan_bridge(parent
, dev
, busnr
, 0);
3351 * Distribute the available bus numbers between hotplug-capable
3352 * bridges to make extending the chain later possible.
3354 available_buses
= end
- busnr
;
3356 /* Scan bridges that need to be reconfigured */
3357 pci_scan_bridge_extend(parent
, dev
, busnr
, available_buses
, 1);
3359 if (!dev
->subordinate
)
3364 EXPORT_SYMBOL_GPL(pci_hp_add_bridge
);