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1/*
2 * mmconfig-shared.c - Low-level direct PCI config space access via
3 * MMCONFIG - common code between i386 and x86-64.
4 *
5 * This code does:
6 * - known chipset handling
7 * - ACPI decoding and validation
8 *
9 * Per-architecture code takes care of the mappings and accesses
10 * themselves.
11 */
12
13#include <linux/pci.h>
14#include <linux/init.h>
15#include <linux/acpi.h>
16#include <linux/sfi_acpi.h>
17#include <linux/bitmap.h>
18#include <linux/dmi.h>
19#include <linux/slab.h>
20#include <asm/e820.h>
21#include <asm/pci_x86.h>
22#include <asm/acpi.h>
23
24#define PREFIX "PCI: "
25
26/* Indicate if the mmcfg resources have been placed into the resource table. */
27static int __initdata pci_mmcfg_resources_inserted;
28
29LIST_HEAD(pci_mmcfg_list);
30
31static __init void pci_mmconfig_remove(struct pci_mmcfg_region *cfg)
32{
33 if (cfg->res.parent)
34 release_resource(&cfg->res);
35 list_del(&cfg->list);
36 kfree(cfg);
37}
38
39static __init void free_all_mmcfg(void)
40{
41 struct pci_mmcfg_region *cfg, *tmp;
42
43 pci_mmcfg_arch_free();
44 list_for_each_entry_safe(cfg, tmp, &pci_mmcfg_list, list)
45 pci_mmconfig_remove(cfg);
46}
47
48static __init void list_add_sorted(struct pci_mmcfg_region *new)
49{
50 struct pci_mmcfg_region *cfg;
51
52 /* keep list sorted by segment and starting bus number */
53 list_for_each_entry(cfg, &pci_mmcfg_list, list) {
54 if (cfg->segment > new->segment ||
55 (cfg->segment == new->segment &&
56 cfg->start_bus >= new->start_bus)) {
57 list_add_tail(&new->list, &cfg->list);
58 return;
59 }
60 }
61 list_add_tail(&new->list, &pci_mmcfg_list);
62}
63
64static __init struct pci_mmcfg_region *pci_mmconfig_add(int segment, int start,
65 int end, u64 addr)
66{
67 struct pci_mmcfg_region *new;
68 struct resource *res;
69
70 if (addr == 0)
71 return NULL;
72
73 new = kzalloc(sizeof(*new), GFP_KERNEL);
74 if (!new)
75 return NULL;
76
77 new->address = addr;
78 new->segment = segment;
79 new->start_bus = start;
80 new->end_bus = end;
81
82 list_add_sorted(new);
83
84 res = &new->res;
85 res->start = addr + PCI_MMCFG_BUS_OFFSET(start);
86 res->end = addr + PCI_MMCFG_BUS_OFFSET(end + 1) - 1;
87 res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
88 snprintf(new->name, PCI_MMCFG_RESOURCE_NAME_LEN,
89 "PCI MMCONFIG %04x [bus %02x-%02x]", segment, start, end);
90 res->name = new->name;
91
92 printk(KERN_INFO PREFIX "MMCONFIG for domain %04x [bus %02x-%02x] at "
93 "%pR (base %#lx)\n", segment, start, end, &new->res,
94 (unsigned long) addr);
95
96 return new;
97}
98
99struct pci_mmcfg_region *pci_mmconfig_lookup(int segment, int bus)
100{
101 struct pci_mmcfg_region *cfg;
102
103 list_for_each_entry(cfg, &pci_mmcfg_list, list)
104 if (cfg->segment == segment &&
105 cfg->start_bus <= bus && bus <= cfg->end_bus)
106 return cfg;
107
108 return NULL;
109}
110
111static const char __init *pci_mmcfg_e7520(void)
112{
113 u32 win;
114 raw_pci_ops->read(0, 0, PCI_DEVFN(0, 0), 0xce, 2, &win);
115
116 win = win & 0xf000;
117 if (win == 0x0000 || win == 0xf000)
118 return NULL;
119
120 if (pci_mmconfig_add(0, 0, 255, win << 16) == NULL)
121 return NULL;
122
123 return "Intel Corporation E7520 Memory Controller Hub";
124}
125
126static const char __init *pci_mmcfg_intel_945(void)
127{
128 u32 pciexbar, mask = 0, len = 0;
129
130 raw_pci_ops->read(0, 0, PCI_DEVFN(0, 0), 0x48, 4, &pciexbar);
131
132 /* Enable bit */
133 if (!(pciexbar & 1))
134 return NULL;
135
136 /* Size bits */
137 switch ((pciexbar >> 1) & 3) {
138 case 0:
139 mask = 0xf0000000U;
140 len = 0x10000000U;
141 break;
142 case 1:
143 mask = 0xf8000000U;
144 len = 0x08000000U;
145 break;
146 case 2:
147 mask = 0xfc000000U;
148 len = 0x04000000U;
149 break;
150 default:
151 return NULL;
152 }
153
154 /* Errata #2, things break when not aligned on a 256Mb boundary */
155 /* Can only happen in 64M/128M mode */
156
157 if ((pciexbar & mask) & 0x0fffffffU)
158 return NULL;
159
160 /* Don't hit the APIC registers and their friends */
161 if ((pciexbar & mask) >= 0xf0000000U)
162 return NULL;
163
164 if (pci_mmconfig_add(0, 0, (len >> 20) - 1, pciexbar & mask) == NULL)
165 return NULL;
166
167 return "Intel Corporation 945G/GZ/P/PL Express Memory Controller Hub";
168}
169
170static const char __init *pci_mmcfg_amd_fam10h(void)
171{
172 u32 low, high, address;
173 u64 base, msr;
174 int i;
175 unsigned segnbits = 0, busnbits, end_bus;
176
177 if (!(pci_probe & PCI_CHECK_ENABLE_AMD_MMCONF))
178 return NULL;
179
180 address = MSR_FAM10H_MMIO_CONF_BASE;
181 if (rdmsr_safe(address, &low, &high))
182 return NULL;
183
184 msr = high;
185 msr <<= 32;
186 msr |= low;
187
188 /* mmconfig is not enable */
189 if (!(msr & FAM10H_MMIO_CONF_ENABLE))
190 return NULL;
191
192 base = msr & (FAM10H_MMIO_CONF_BASE_MASK<<FAM10H_MMIO_CONF_BASE_SHIFT);
193
194 busnbits = (msr >> FAM10H_MMIO_CONF_BUSRANGE_SHIFT) &
195 FAM10H_MMIO_CONF_BUSRANGE_MASK;
196
197 /*
198 * only handle bus 0 ?
199 * need to skip it
200 */
201 if (!busnbits)
202 return NULL;
203
204 if (busnbits > 8) {
205 segnbits = busnbits - 8;
206 busnbits = 8;
207 }
208
209 end_bus = (1 << busnbits) - 1;
210 for (i = 0; i < (1 << segnbits); i++)
211 if (pci_mmconfig_add(i, 0, end_bus,
212 base + (1<<28) * i) == NULL) {
213 free_all_mmcfg();
214 return NULL;
215 }
216
217 return "AMD Family 10h NB";
218}
219
220static bool __initdata mcp55_checked;
221static const char __init *pci_mmcfg_nvidia_mcp55(void)
222{
223 int bus;
224 int mcp55_mmconf_found = 0;
225
226 static const u32 extcfg_regnum = 0x90;
227 static const u32 extcfg_regsize = 4;
228 static const u32 extcfg_enable_mask = 1<<31;
229 static const u32 extcfg_start_mask = 0xff<<16;
230 static const int extcfg_start_shift = 16;
231 static const u32 extcfg_size_mask = 0x3<<28;
232 static const int extcfg_size_shift = 28;
233 static const int extcfg_sizebus[] = {0x100, 0x80, 0x40, 0x20};
234 static const u32 extcfg_base_mask[] = {0x7ff8, 0x7ffc, 0x7ffe, 0x7fff};
235 static const int extcfg_base_lshift = 25;
236
237 /*
238 * do check if amd fam10h already took over
239 */
240 if (!acpi_disabled || !list_empty(&pci_mmcfg_list) || mcp55_checked)
241 return NULL;
242
243 mcp55_checked = true;
244 for (bus = 0; bus < 256; bus++) {
245 u64 base;
246 u32 l, extcfg;
247 u16 vendor, device;
248 int start, size_index, end;
249
250 raw_pci_ops->read(0, bus, PCI_DEVFN(0, 0), 0, 4, &l);
251 vendor = l & 0xffff;
252 device = (l >> 16) & 0xffff;
253
254 if (PCI_VENDOR_ID_NVIDIA != vendor || 0x0369 != device)
255 continue;
256
257 raw_pci_ops->read(0, bus, PCI_DEVFN(0, 0), extcfg_regnum,
258 extcfg_regsize, &extcfg);
259
260 if (!(extcfg & extcfg_enable_mask))
261 continue;
262
263 size_index = (extcfg & extcfg_size_mask) >> extcfg_size_shift;
264 base = extcfg & extcfg_base_mask[size_index];
265 /* base could > 4G */
266 base <<= extcfg_base_lshift;
267 start = (extcfg & extcfg_start_mask) >> extcfg_start_shift;
268 end = start + extcfg_sizebus[size_index] - 1;
269 if (pci_mmconfig_add(0, start, end, base) == NULL)
270 continue;
271 mcp55_mmconf_found++;
272 }
273
274 if (!mcp55_mmconf_found)
275 return NULL;
276
277 return "nVidia MCP55";
278}
279
280struct pci_mmcfg_hostbridge_probe {
281 u32 bus;
282 u32 devfn;
283 u32 vendor;
284 u32 device;
285 const char *(*probe)(void);
286};
287
288static struct pci_mmcfg_hostbridge_probe pci_mmcfg_probes[] __initdata = {
289 { 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_INTEL,
290 PCI_DEVICE_ID_INTEL_E7520_MCH, pci_mmcfg_e7520 },
291 { 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_INTEL,
292 PCI_DEVICE_ID_INTEL_82945G_HB, pci_mmcfg_intel_945 },
293 { 0, PCI_DEVFN(0x18, 0), PCI_VENDOR_ID_AMD,
294 0x1200, pci_mmcfg_amd_fam10h },
295 { 0xff, PCI_DEVFN(0, 0), PCI_VENDOR_ID_AMD,
296 0x1200, pci_mmcfg_amd_fam10h },
297 { 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_NVIDIA,
298 0x0369, pci_mmcfg_nvidia_mcp55 },
299};
300
301static void __init pci_mmcfg_check_end_bus_number(void)
302{
303 struct pci_mmcfg_region *cfg, *cfgx;
304
305 /* Fixup overlaps */
306 list_for_each_entry(cfg, &pci_mmcfg_list, list) {
307 if (cfg->end_bus < cfg->start_bus)
308 cfg->end_bus = 255;
309
310 /* Don't access the list head ! */
311 if (cfg->list.next == &pci_mmcfg_list)
312 break;
313
314 cfgx = list_entry(cfg->list.next, typeof(*cfg), list);
315 if (cfg->end_bus >= cfgx->start_bus)
316 cfg->end_bus = cfgx->start_bus - 1;
317 }
318}
319
320static int __init pci_mmcfg_check_hostbridge(void)
321{
322 u32 l;
323 u32 bus, devfn;
324 u16 vendor, device;
325 int i;
326 const char *name;
327
328 if (!raw_pci_ops)
329 return 0;
330
331 free_all_mmcfg();
332
333 for (i = 0; i < ARRAY_SIZE(pci_mmcfg_probes); i++) {
334 bus = pci_mmcfg_probes[i].bus;
335 devfn = pci_mmcfg_probes[i].devfn;
336 raw_pci_ops->read(0, bus, devfn, 0, 4, &l);
337 vendor = l & 0xffff;
338 device = (l >> 16) & 0xffff;
339
340 name = NULL;
341 if (pci_mmcfg_probes[i].vendor == vendor &&
342 pci_mmcfg_probes[i].device == device)
343 name = pci_mmcfg_probes[i].probe();
344
345 if (name)
346 printk(KERN_INFO PREFIX "%s with MMCONFIG support\n",
347 name);
348 }
349
350 /* some end_bus_number is crazy, fix it */
351 pci_mmcfg_check_end_bus_number();
352
353 return !list_empty(&pci_mmcfg_list);
354}
355
356static void __init pci_mmcfg_insert_resources(void)
357{
358 struct pci_mmcfg_region *cfg;
359
360 list_for_each_entry(cfg, &pci_mmcfg_list, list)
361 insert_resource(&iomem_resource, &cfg->res);
362
363 /* Mark that the resources have been inserted. */
364 pci_mmcfg_resources_inserted = 1;
365}
366
367static acpi_status __init check_mcfg_resource(struct acpi_resource *res,
368 void *data)
369{
370 struct resource *mcfg_res = data;
371 struct acpi_resource_address64 address;
372 acpi_status status;
373
374 if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
375 struct acpi_resource_fixed_memory32 *fixmem32 =
376 &res->data.fixed_memory32;
377 if (!fixmem32)
378 return AE_OK;
379 if ((mcfg_res->start >= fixmem32->address) &&
380 (mcfg_res->end < (fixmem32->address +
381 fixmem32->address_length))) {
382 mcfg_res->flags = 1;
383 return AE_CTRL_TERMINATE;
384 }
385 }
386 if ((res->type != ACPI_RESOURCE_TYPE_ADDRESS32) &&
387 (res->type != ACPI_RESOURCE_TYPE_ADDRESS64))
388 return AE_OK;
389
390 status = acpi_resource_to_address64(res, &address);
391 if (ACPI_FAILURE(status) ||
392 (address.address_length <= 0) ||
393 (address.resource_type != ACPI_MEMORY_RANGE))
394 return AE_OK;
395
396 if ((mcfg_res->start >= address.minimum) &&
397 (mcfg_res->end < (address.minimum + address.address_length))) {
398 mcfg_res->flags = 1;
399 return AE_CTRL_TERMINATE;
400 }
401 return AE_OK;
402}
403
404static acpi_status __init find_mboard_resource(acpi_handle handle, u32 lvl,
405 void *context, void **rv)
406{
407 struct resource *mcfg_res = context;
408
409 acpi_walk_resources(handle, METHOD_NAME__CRS,
410 check_mcfg_resource, context);
411
412 if (mcfg_res->flags)
413 return AE_CTRL_TERMINATE;
414
415 return AE_OK;
416}
417
418static int __init is_acpi_reserved(u64 start, u64 end, unsigned not_used)
419{
420 struct resource mcfg_res;
421
422 mcfg_res.start = start;
423 mcfg_res.end = end - 1;
424 mcfg_res.flags = 0;
425
426 acpi_get_devices("PNP0C01", find_mboard_resource, &mcfg_res, NULL);
427
428 if (!mcfg_res.flags)
429 acpi_get_devices("PNP0C02", find_mboard_resource, &mcfg_res,
430 NULL);
431
432 return mcfg_res.flags;
433}
434
435typedef int (*check_reserved_t)(u64 start, u64 end, unsigned type);
436
437static int __init is_mmconf_reserved(check_reserved_t is_reserved,
438 struct pci_mmcfg_region *cfg, int with_e820)
439{
440 u64 addr = cfg->res.start;
441 u64 size = resource_size(&cfg->res);
442 u64 old_size = size;
443 int valid = 0, num_buses;
444
445 while (!is_reserved(addr, addr + size, E820_RESERVED)) {
446 size >>= 1;
447 if (size < (16UL<<20))
448 break;
449 }
450
451 if (size >= (16UL<<20) || size == old_size) {
452 printk(KERN_INFO PREFIX "MMCONFIG at %pR reserved in %s\n",
453 &cfg->res,
454 with_e820 ? "E820" : "ACPI motherboard resources");
455 valid = 1;
456
457 if (old_size != size) {
458 /* update end_bus */
459 cfg->end_bus = cfg->start_bus + ((size>>20) - 1);
460 num_buses = cfg->end_bus - cfg->start_bus + 1;
461 cfg->res.end = cfg->res.start +
462 PCI_MMCFG_BUS_OFFSET(num_buses) - 1;
463 snprintf(cfg->name, PCI_MMCFG_RESOURCE_NAME_LEN,
464 "PCI MMCONFIG %04x [bus %02x-%02x]",
465 cfg->segment, cfg->start_bus, cfg->end_bus);
466 printk(KERN_INFO PREFIX
467 "MMCONFIG for %04x [bus%02x-%02x] "
468 "at %pR (base %#lx) (size reduced!)\n",
469 cfg->segment, cfg->start_bus, cfg->end_bus,
470 &cfg->res, (unsigned long) cfg->address);
471 }
472 }
473
474 return valid;
475}
476
477static void __init pci_mmcfg_reject_broken(int early)
478{
479 struct pci_mmcfg_region *cfg;
480
481 list_for_each_entry(cfg, &pci_mmcfg_list, list) {
482 int valid = 0;
483
484 if (!early && !acpi_disabled) {
485 valid = is_mmconf_reserved(is_acpi_reserved, cfg, 0);
486
487 if (valid)
488 continue;
489 else
490 printk(KERN_ERR FW_BUG PREFIX
491 "MMCONFIG at %pR not reserved in "
492 "ACPI motherboard resources\n",
493 &cfg->res);
494 }
495
496 /* Don't try to do this check unless configuration
497 type 1 is available. how about type 2 ?*/
498 if (raw_pci_ops)
499 valid = is_mmconf_reserved(e820_all_mapped, cfg, 1);
500
501 if (!valid)
502 goto reject;
503 }
504
505 return;
506
507reject:
508 printk(KERN_INFO PREFIX "not using MMCONFIG\n");
509 free_all_mmcfg();
510}
511
512static int __initdata known_bridge;
513
514static int __init acpi_mcfg_check_entry(struct acpi_table_mcfg *mcfg,
515 struct acpi_mcfg_allocation *cfg)
516{
517 int year;
518
519 if (cfg->address < 0xFFFFFFFF)
520 return 0;
521
522 if (!strcmp(mcfg->header.oem_id, "SGI") ||
523 !strcmp(mcfg->header.oem_id, "SGI2"))
524 return 0;
525
526 if (mcfg->header.revision >= 1) {
527 if (dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL) &&
528 year >= 2010)
529 return 0;
530 }
531
532 printk(KERN_ERR PREFIX "MCFG region for %04x [bus %02x-%02x] at %#llx "
533 "is above 4GB, ignored\n", cfg->pci_segment,
534 cfg->start_bus_number, cfg->end_bus_number, cfg->address);
535 return -EINVAL;
536}
537
538static int __init pci_parse_mcfg(struct acpi_table_header *header)
539{
540 struct acpi_table_mcfg *mcfg;
541 struct acpi_mcfg_allocation *cfg_table, *cfg;
542 unsigned long i;
543 int entries;
544
545 if (!header)
546 return -EINVAL;
547
548 mcfg = (struct acpi_table_mcfg *)header;
549
550 /* how many config structures do we have */
551 free_all_mmcfg();
552 entries = 0;
553 i = header->length - sizeof(struct acpi_table_mcfg);
554 while (i >= sizeof(struct acpi_mcfg_allocation)) {
555 entries++;
556 i -= sizeof(struct acpi_mcfg_allocation);
557 };
558 if (entries == 0) {
559 printk(KERN_ERR PREFIX "MMCONFIG has no entries\n");
560 return -ENODEV;
561 }
562
563 cfg_table = (struct acpi_mcfg_allocation *) &mcfg[1];
564 for (i = 0; i < entries; i++) {
565 cfg = &cfg_table[i];
566 if (acpi_mcfg_check_entry(mcfg, cfg)) {
567 free_all_mmcfg();
568 return -ENODEV;
569 }
570
571 if (pci_mmconfig_add(cfg->pci_segment, cfg->start_bus_number,
572 cfg->end_bus_number, cfg->address) == NULL) {
573 printk(KERN_WARNING PREFIX
574 "no memory for MCFG entries\n");
575 free_all_mmcfg();
576 return -ENOMEM;
577 }
578 }
579
580 return 0;
581}
582
583static void __init __pci_mmcfg_init(int early)
584{
585 /* MMCONFIG disabled */
586 if ((pci_probe & PCI_PROBE_MMCONF) == 0)
587 return;
588
589 /* MMCONFIG already enabled */
590 if (!early && !(pci_probe & PCI_PROBE_MASK & ~PCI_PROBE_MMCONF))
591 return;
592
593 /* for late to exit */
594 if (known_bridge)
595 return;
596
597 if (early) {
598 if (pci_mmcfg_check_hostbridge())
599 known_bridge = 1;
600 }
601
602 if (!known_bridge)
603 acpi_sfi_table_parse(ACPI_SIG_MCFG, pci_parse_mcfg);
604
605 pci_mmcfg_reject_broken(early);
606
607 if (list_empty(&pci_mmcfg_list))
608 return;
609
610 if (pcibios_last_bus < 0) {
611 const struct pci_mmcfg_region *cfg;
612
613 list_for_each_entry(cfg, &pci_mmcfg_list, list) {
614 if (cfg->segment)
615 break;
616 pcibios_last_bus = cfg->end_bus;
617 }
618 }
619
620 if (pci_mmcfg_arch_init())
621 pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
622 else {
623 /*
624 * Signal not to attempt to insert mmcfg resources because
625 * the architecture mmcfg setup could not initialize.
626 */
627 pci_mmcfg_resources_inserted = 1;
628 }
629}
630
631void __init pci_mmcfg_early_init(void)
632{
633 __pci_mmcfg_init(1);
634}
635
636void __init pci_mmcfg_late_init(void)
637{
638 __pci_mmcfg_init(0);
639}
640
641static int __init pci_mmcfg_late_insert_resources(void)
642{
643 /*
644 * If resources are already inserted or we are not using MMCONFIG,
645 * don't insert the resources.
646 */
647 if ((pci_mmcfg_resources_inserted == 1) ||
648 (pci_probe & PCI_PROBE_MMCONF) == 0 ||
649 list_empty(&pci_mmcfg_list))
650 return 1;
651
652 /*
653 * Attempt to insert the mmcfg resources but not with the busy flag
654 * marked so it won't cause request errors when __request_region is
655 * called.
656 */
657 pci_mmcfg_insert_resources();
658
659 return 0;
660}
661
662/*
663 * Perform MMCONFIG resource insertion after PCI initialization to allow for
664 * misprogrammed MCFG tables that state larger sizes but actually conflict
665 * with other system resources.
666 */
667late_initcall(pci_mmcfg_late_insert_resources);
1/*
2 * mmconfig-shared.c - Low-level direct PCI config space access via
3 * MMCONFIG - common code between i386 and x86-64.
4 *
5 * This code does:
6 * - known chipset handling
7 * - ACPI decoding and validation
8 *
9 * Per-architecture code takes care of the mappings and accesses
10 * themselves.
11 */
12
13#include <linux/pci.h>
14#include <linux/init.h>
15#include <linux/sfi_acpi.h>
16#include <linux/bitmap.h>
17#include <linux/dmi.h>
18#include <linux/slab.h>
19#include <linux/mutex.h>
20#include <linux/rculist.h>
21#include <asm/e820.h>
22#include <asm/pci_x86.h>
23#include <asm/acpi.h>
24
25#define PREFIX "PCI: "
26
27/* Indicate if the mmcfg resources have been placed into the resource table. */
28static bool pci_mmcfg_running_state;
29static bool pci_mmcfg_arch_init_failed;
30static DEFINE_MUTEX(pci_mmcfg_lock);
31
32LIST_HEAD(pci_mmcfg_list);
33
34static __init void pci_mmconfig_remove(struct pci_mmcfg_region *cfg)
35{
36 if (cfg->res.parent)
37 release_resource(&cfg->res);
38 list_del(&cfg->list);
39 kfree(cfg);
40}
41
42static __init void free_all_mmcfg(void)
43{
44 struct pci_mmcfg_region *cfg, *tmp;
45
46 pci_mmcfg_arch_free();
47 list_for_each_entry_safe(cfg, tmp, &pci_mmcfg_list, list)
48 pci_mmconfig_remove(cfg);
49}
50
51static void list_add_sorted(struct pci_mmcfg_region *new)
52{
53 struct pci_mmcfg_region *cfg;
54
55 /* keep list sorted by segment and starting bus number */
56 list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list) {
57 if (cfg->segment > new->segment ||
58 (cfg->segment == new->segment &&
59 cfg->start_bus >= new->start_bus)) {
60 list_add_tail_rcu(&new->list, &cfg->list);
61 return;
62 }
63 }
64 list_add_tail_rcu(&new->list, &pci_mmcfg_list);
65}
66
67static struct pci_mmcfg_region *pci_mmconfig_alloc(int segment, int start,
68 int end, u64 addr)
69{
70 struct pci_mmcfg_region *new;
71 struct resource *res;
72
73 if (addr == 0)
74 return NULL;
75
76 new = kzalloc(sizeof(*new), GFP_KERNEL);
77 if (!new)
78 return NULL;
79
80 new->address = addr;
81 new->segment = segment;
82 new->start_bus = start;
83 new->end_bus = end;
84
85 res = &new->res;
86 res->start = addr + PCI_MMCFG_BUS_OFFSET(start);
87 res->end = addr + PCI_MMCFG_BUS_OFFSET(end + 1) - 1;
88 res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
89 snprintf(new->name, PCI_MMCFG_RESOURCE_NAME_LEN,
90 "PCI MMCONFIG %04x [bus %02x-%02x]", segment, start, end);
91 res->name = new->name;
92
93 return new;
94}
95
96static __init struct pci_mmcfg_region *pci_mmconfig_add(int segment, int start,
97 int end, u64 addr)
98{
99 struct pci_mmcfg_region *new;
100
101 new = pci_mmconfig_alloc(segment, start, end, addr);
102 if (new) {
103 mutex_lock(&pci_mmcfg_lock);
104 list_add_sorted(new);
105 mutex_unlock(&pci_mmcfg_lock);
106
107 pr_info(PREFIX
108 "MMCONFIG for domain %04x [bus %02x-%02x] at %pR "
109 "(base %#lx)\n",
110 segment, start, end, &new->res, (unsigned long)addr);
111 }
112
113 return new;
114}
115
116struct pci_mmcfg_region *pci_mmconfig_lookup(int segment, int bus)
117{
118 struct pci_mmcfg_region *cfg;
119
120 list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list)
121 if (cfg->segment == segment &&
122 cfg->start_bus <= bus && bus <= cfg->end_bus)
123 return cfg;
124
125 return NULL;
126}
127
128static const char __init *pci_mmcfg_e7520(void)
129{
130 u32 win;
131 raw_pci_ops->read(0, 0, PCI_DEVFN(0, 0), 0xce, 2, &win);
132
133 win = win & 0xf000;
134 if (win == 0x0000 || win == 0xf000)
135 return NULL;
136
137 if (pci_mmconfig_add(0, 0, 255, win << 16) == NULL)
138 return NULL;
139
140 return "Intel Corporation E7520 Memory Controller Hub";
141}
142
143static const char __init *pci_mmcfg_intel_945(void)
144{
145 u32 pciexbar, mask = 0, len = 0;
146
147 raw_pci_ops->read(0, 0, PCI_DEVFN(0, 0), 0x48, 4, &pciexbar);
148
149 /* Enable bit */
150 if (!(pciexbar & 1))
151 return NULL;
152
153 /* Size bits */
154 switch ((pciexbar >> 1) & 3) {
155 case 0:
156 mask = 0xf0000000U;
157 len = 0x10000000U;
158 break;
159 case 1:
160 mask = 0xf8000000U;
161 len = 0x08000000U;
162 break;
163 case 2:
164 mask = 0xfc000000U;
165 len = 0x04000000U;
166 break;
167 default:
168 return NULL;
169 }
170
171 /* Errata #2, things break when not aligned on a 256Mb boundary */
172 /* Can only happen in 64M/128M mode */
173
174 if ((pciexbar & mask) & 0x0fffffffU)
175 return NULL;
176
177 /* Don't hit the APIC registers and their friends */
178 if ((pciexbar & mask) >= 0xf0000000U)
179 return NULL;
180
181 if (pci_mmconfig_add(0, 0, (len >> 20) - 1, pciexbar & mask) == NULL)
182 return NULL;
183
184 return "Intel Corporation 945G/GZ/P/PL Express Memory Controller Hub";
185}
186
187static const char __init *pci_mmcfg_amd_fam10h(void)
188{
189 u32 low, high, address;
190 u64 base, msr;
191 int i;
192 unsigned segnbits = 0, busnbits, end_bus;
193
194 if (!(pci_probe & PCI_CHECK_ENABLE_AMD_MMCONF))
195 return NULL;
196
197 address = MSR_FAM10H_MMIO_CONF_BASE;
198 if (rdmsr_safe(address, &low, &high))
199 return NULL;
200
201 msr = high;
202 msr <<= 32;
203 msr |= low;
204
205 /* mmconfig is not enable */
206 if (!(msr & FAM10H_MMIO_CONF_ENABLE))
207 return NULL;
208
209 base = msr & (FAM10H_MMIO_CONF_BASE_MASK<<FAM10H_MMIO_CONF_BASE_SHIFT);
210
211 busnbits = (msr >> FAM10H_MMIO_CONF_BUSRANGE_SHIFT) &
212 FAM10H_MMIO_CONF_BUSRANGE_MASK;
213
214 /*
215 * only handle bus 0 ?
216 * need to skip it
217 */
218 if (!busnbits)
219 return NULL;
220
221 if (busnbits > 8) {
222 segnbits = busnbits - 8;
223 busnbits = 8;
224 }
225
226 end_bus = (1 << busnbits) - 1;
227 for (i = 0; i < (1 << segnbits); i++)
228 if (pci_mmconfig_add(i, 0, end_bus,
229 base + (1<<28) * i) == NULL) {
230 free_all_mmcfg();
231 return NULL;
232 }
233
234 return "AMD Family 10h NB";
235}
236
237static bool __initdata mcp55_checked;
238static const char __init *pci_mmcfg_nvidia_mcp55(void)
239{
240 int bus;
241 int mcp55_mmconf_found = 0;
242
243 static const u32 extcfg_regnum = 0x90;
244 static const u32 extcfg_regsize = 4;
245 static const u32 extcfg_enable_mask = 1<<31;
246 static const u32 extcfg_start_mask = 0xff<<16;
247 static const int extcfg_start_shift = 16;
248 static const u32 extcfg_size_mask = 0x3<<28;
249 static const int extcfg_size_shift = 28;
250 static const int extcfg_sizebus[] = {0x100, 0x80, 0x40, 0x20};
251 static const u32 extcfg_base_mask[] = {0x7ff8, 0x7ffc, 0x7ffe, 0x7fff};
252 static const int extcfg_base_lshift = 25;
253
254 /*
255 * do check if amd fam10h already took over
256 */
257 if (!acpi_disabled || !list_empty(&pci_mmcfg_list) || mcp55_checked)
258 return NULL;
259
260 mcp55_checked = true;
261 for (bus = 0; bus < 256; bus++) {
262 u64 base;
263 u32 l, extcfg;
264 u16 vendor, device;
265 int start, size_index, end;
266
267 raw_pci_ops->read(0, bus, PCI_DEVFN(0, 0), 0, 4, &l);
268 vendor = l & 0xffff;
269 device = (l >> 16) & 0xffff;
270
271 if (PCI_VENDOR_ID_NVIDIA != vendor || 0x0369 != device)
272 continue;
273
274 raw_pci_ops->read(0, bus, PCI_DEVFN(0, 0), extcfg_regnum,
275 extcfg_regsize, &extcfg);
276
277 if (!(extcfg & extcfg_enable_mask))
278 continue;
279
280 size_index = (extcfg & extcfg_size_mask) >> extcfg_size_shift;
281 base = extcfg & extcfg_base_mask[size_index];
282 /* base could > 4G */
283 base <<= extcfg_base_lshift;
284 start = (extcfg & extcfg_start_mask) >> extcfg_start_shift;
285 end = start + extcfg_sizebus[size_index] - 1;
286 if (pci_mmconfig_add(0, start, end, base) == NULL)
287 continue;
288 mcp55_mmconf_found++;
289 }
290
291 if (!mcp55_mmconf_found)
292 return NULL;
293
294 return "nVidia MCP55";
295}
296
297struct pci_mmcfg_hostbridge_probe {
298 u32 bus;
299 u32 devfn;
300 u32 vendor;
301 u32 device;
302 const char *(*probe)(void);
303};
304
305static struct pci_mmcfg_hostbridge_probe pci_mmcfg_probes[] __initdata = {
306 { 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_INTEL,
307 PCI_DEVICE_ID_INTEL_E7520_MCH, pci_mmcfg_e7520 },
308 { 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_INTEL,
309 PCI_DEVICE_ID_INTEL_82945G_HB, pci_mmcfg_intel_945 },
310 { 0, PCI_DEVFN(0x18, 0), PCI_VENDOR_ID_AMD,
311 0x1200, pci_mmcfg_amd_fam10h },
312 { 0xff, PCI_DEVFN(0, 0), PCI_VENDOR_ID_AMD,
313 0x1200, pci_mmcfg_amd_fam10h },
314 { 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_NVIDIA,
315 0x0369, pci_mmcfg_nvidia_mcp55 },
316};
317
318static void __init pci_mmcfg_check_end_bus_number(void)
319{
320 struct pci_mmcfg_region *cfg, *cfgx;
321
322 /* Fixup overlaps */
323 list_for_each_entry(cfg, &pci_mmcfg_list, list) {
324 if (cfg->end_bus < cfg->start_bus)
325 cfg->end_bus = 255;
326
327 /* Don't access the list head ! */
328 if (cfg->list.next == &pci_mmcfg_list)
329 break;
330
331 cfgx = list_entry(cfg->list.next, typeof(*cfg), list);
332 if (cfg->end_bus >= cfgx->start_bus)
333 cfg->end_bus = cfgx->start_bus - 1;
334 }
335}
336
337static int __init pci_mmcfg_check_hostbridge(void)
338{
339 u32 l;
340 u32 bus, devfn;
341 u16 vendor, device;
342 int i;
343 const char *name;
344
345 if (!raw_pci_ops)
346 return 0;
347
348 free_all_mmcfg();
349
350 for (i = 0; i < ARRAY_SIZE(pci_mmcfg_probes); i++) {
351 bus = pci_mmcfg_probes[i].bus;
352 devfn = pci_mmcfg_probes[i].devfn;
353 raw_pci_ops->read(0, bus, devfn, 0, 4, &l);
354 vendor = l & 0xffff;
355 device = (l >> 16) & 0xffff;
356
357 name = NULL;
358 if (pci_mmcfg_probes[i].vendor == vendor &&
359 pci_mmcfg_probes[i].device == device)
360 name = pci_mmcfg_probes[i].probe();
361
362 if (name)
363 pr_info(PREFIX "%s with MMCONFIG support\n", name);
364 }
365
366 /* some end_bus_number is crazy, fix it */
367 pci_mmcfg_check_end_bus_number();
368
369 return !list_empty(&pci_mmcfg_list);
370}
371
372static acpi_status check_mcfg_resource(struct acpi_resource *res, void *data)
373{
374 struct resource *mcfg_res = data;
375 struct acpi_resource_address64 address;
376 acpi_status status;
377
378 if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
379 struct acpi_resource_fixed_memory32 *fixmem32 =
380 &res->data.fixed_memory32;
381 if (!fixmem32)
382 return AE_OK;
383 if ((mcfg_res->start >= fixmem32->address) &&
384 (mcfg_res->end < (fixmem32->address +
385 fixmem32->address_length))) {
386 mcfg_res->flags = 1;
387 return AE_CTRL_TERMINATE;
388 }
389 }
390 if ((res->type != ACPI_RESOURCE_TYPE_ADDRESS32) &&
391 (res->type != ACPI_RESOURCE_TYPE_ADDRESS64))
392 return AE_OK;
393
394 status = acpi_resource_to_address64(res, &address);
395 if (ACPI_FAILURE(status) ||
396 (address.address_length <= 0) ||
397 (address.resource_type != ACPI_MEMORY_RANGE))
398 return AE_OK;
399
400 if ((mcfg_res->start >= address.minimum) &&
401 (mcfg_res->end < (address.minimum + address.address_length))) {
402 mcfg_res->flags = 1;
403 return AE_CTRL_TERMINATE;
404 }
405 return AE_OK;
406}
407
408static acpi_status find_mboard_resource(acpi_handle handle, u32 lvl,
409 void *context, void **rv)
410{
411 struct resource *mcfg_res = context;
412
413 acpi_walk_resources(handle, METHOD_NAME__CRS,
414 check_mcfg_resource, context);
415
416 if (mcfg_res->flags)
417 return AE_CTRL_TERMINATE;
418
419 return AE_OK;
420}
421
422static int is_acpi_reserved(u64 start, u64 end, unsigned not_used)
423{
424 struct resource mcfg_res;
425
426 mcfg_res.start = start;
427 mcfg_res.end = end - 1;
428 mcfg_res.flags = 0;
429
430 acpi_get_devices("PNP0C01", find_mboard_resource, &mcfg_res, NULL);
431
432 if (!mcfg_res.flags)
433 acpi_get_devices("PNP0C02", find_mboard_resource, &mcfg_res,
434 NULL);
435
436 return mcfg_res.flags;
437}
438
439typedef int (*check_reserved_t)(u64 start, u64 end, unsigned type);
440
441static int __ref is_mmconf_reserved(check_reserved_t is_reserved,
442 struct pci_mmcfg_region *cfg,
443 struct device *dev, int with_e820)
444{
445 u64 addr = cfg->res.start;
446 u64 size = resource_size(&cfg->res);
447 u64 old_size = size;
448 int num_buses;
449 char *method = with_e820 ? "E820" : "ACPI motherboard resources";
450
451 while (!is_reserved(addr, addr + size, E820_RESERVED)) {
452 size >>= 1;
453 if (size < (16UL<<20))
454 break;
455 }
456
457 if (size < (16UL<<20) && size != old_size)
458 return 0;
459
460 if (dev)
461 dev_info(dev, "MMCONFIG at %pR reserved in %s\n",
462 &cfg->res, method);
463 else
464 pr_info(PREFIX "MMCONFIG at %pR reserved in %s\n",
465 &cfg->res, method);
466
467 if (old_size != size) {
468 /* update end_bus */
469 cfg->end_bus = cfg->start_bus + ((size>>20) - 1);
470 num_buses = cfg->end_bus - cfg->start_bus + 1;
471 cfg->res.end = cfg->res.start +
472 PCI_MMCFG_BUS_OFFSET(num_buses) - 1;
473 snprintf(cfg->name, PCI_MMCFG_RESOURCE_NAME_LEN,
474 "PCI MMCONFIG %04x [bus %02x-%02x]",
475 cfg->segment, cfg->start_bus, cfg->end_bus);
476
477 if (dev)
478 dev_info(dev,
479 "MMCONFIG "
480 "at %pR (base %#lx) (size reduced!)\n",
481 &cfg->res, (unsigned long) cfg->address);
482 else
483 pr_info(PREFIX
484 "MMCONFIG for %04x [bus%02x-%02x] "
485 "at %pR (base %#lx) (size reduced!)\n",
486 cfg->segment, cfg->start_bus, cfg->end_bus,
487 &cfg->res, (unsigned long) cfg->address);
488 }
489
490 return 1;
491}
492
493static int __ref pci_mmcfg_check_reserved(struct device *dev,
494 struct pci_mmcfg_region *cfg, int early)
495{
496 if (!early && !acpi_disabled) {
497 if (is_mmconf_reserved(is_acpi_reserved, cfg, dev, 0))
498 return 1;
499
500 if (dev)
501 dev_info(dev, FW_INFO
502 "MMCONFIG at %pR not reserved in "
503 "ACPI motherboard resources\n",
504 &cfg->res);
505 else
506 pr_info(FW_INFO PREFIX
507 "MMCONFIG at %pR not reserved in "
508 "ACPI motherboard resources\n",
509 &cfg->res);
510 }
511
512 /*
513 * e820_all_mapped() is marked as __init.
514 * All entries from ACPI MCFG table have been checked at boot time.
515 * For MCFG information constructed from hotpluggable host bridge's
516 * _CBA method, just assume it's reserved.
517 */
518 if (pci_mmcfg_running_state)
519 return 1;
520
521 /* Don't try to do this check unless configuration
522 type 1 is available. how about type 2 ?*/
523 if (raw_pci_ops)
524 return is_mmconf_reserved(e820_all_mapped, cfg, dev, 1);
525
526 return 0;
527}
528
529static void __init pci_mmcfg_reject_broken(int early)
530{
531 struct pci_mmcfg_region *cfg;
532
533 list_for_each_entry(cfg, &pci_mmcfg_list, list) {
534 if (pci_mmcfg_check_reserved(NULL, cfg, early) == 0) {
535 pr_info(PREFIX "not using MMCONFIG\n");
536 free_all_mmcfg();
537 return;
538 }
539 }
540}
541
542static int __init acpi_mcfg_check_entry(struct acpi_table_mcfg *mcfg,
543 struct acpi_mcfg_allocation *cfg)
544{
545 int year;
546
547 if (cfg->address < 0xFFFFFFFF)
548 return 0;
549
550 if (!strncmp(mcfg->header.oem_id, "SGI", 3))
551 return 0;
552
553 if (mcfg->header.revision >= 1) {
554 if (dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL) &&
555 year >= 2010)
556 return 0;
557 }
558
559 pr_err(PREFIX "MCFG region for %04x [bus %02x-%02x] at %#llx "
560 "is above 4GB, ignored\n", cfg->pci_segment,
561 cfg->start_bus_number, cfg->end_bus_number, cfg->address);
562 return -EINVAL;
563}
564
565static int __init pci_parse_mcfg(struct acpi_table_header *header)
566{
567 struct acpi_table_mcfg *mcfg;
568 struct acpi_mcfg_allocation *cfg_table, *cfg;
569 unsigned long i;
570 int entries;
571
572 if (!header)
573 return -EINVAL;
574
575 mcfg = (struct acpi_table_mcfg *)header;
576
577 /* how many config structures do we have */
578 free_all_mmcfg();
579 entries = 0;
580 i = header->length - sizeof(struct acpi_table_mcfg);
581 while (i >= sizeof(struct acpi_mcfg_allocation)) {
582 entries++;
583 i -= sizeof(struct acpi_mcfg_allocation);
584 }
585 if (entries == 0) {
586 pr_err(PREFIX "MMCONFIG has no entries\n");
587 return -ENODEV;
588 }
589
590 cfg_table = (struct acpi_mcfg_allocation *) &mcfg[1];
591 for (i = 0; i < entries; i++) {
592 cfg = &cfg_table[i];
593 if (acpi_mcfg_check_entry(mcfg, cfg)) {
594 free_all_mmcfg();
595 return -ENODEV;
596 }
597
598 if (pci_mmconfig_add(cfg->pci_segment, cfg->start_bus_number,
599 cfg->end_bus_number, cfg->address) == NULL) {
600 pr_warn(PREFIX "no memory for MCFG entries\n");
601 free_all_mmcfg();
602 return -ENOMEM;
603 }
604 }
605
606 return 0;
607}
608
609static void __init __pci_mmcfg_init(int early)
610{
611 pci_mmcfg_reject_broken(early);
612 if (list_empty(&pci_mmcfg_list))
613 return;
614
615 if (pcibios_last_bus < 0) {
616 const struct pci_mmcfg_region *cfg;
617
618 list_for_each_entry(cfg, &pci_mmcfg_list, list) {
619 if (cfg->segment)
620 break;
621 pcibios_last_bus = cfg->end_bus;
622 }
623 }
624
625 if (pci_mmcfg_arch_init())
626 pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
627 else {
628 free_all_mmcfg();
629 pci_mmcfg_arch_init_failed = true;
630 }
631}
632
633static int __initdata known_bridge;
634
635void __init pci_mmcfg_early_init(void)
636{
637 if (pci_probe & PCI_PROBE_MMCONF) {
638 if (pci_mmcfg_check_hostbridge())
639 known_bridge = 1;
640 else
641 acpi_sfi_table_parse(ACPI_SIG_MCFG, pci_parse_mcfg);
642 __pci_mmcfg_init(1);
643 }
644}
645
646void __init pci_mmcfg_late_init(void)
647{
648 /* MMCONFIG disabled */
649 if ((pci_probe & PCI_PROBE_MMCONF) == 0)
650 return;
651
652 if (known_bridge)
653 return;
654
655 /* MMCONFIG hasn't been enabled yet, try again */
656 if (pci_probe & PCI_PROBE_MASK & ~PCI_PROBE_MMCONF) {
657 acpi_sfi_table_parse(ACPI_SIG_MCFG, pci_parse_mcfg);
658 __pci_mmcfg_init(0);
659 }
660}
661
662static int __init pci_mmcfg_late_insert_resources(void)
663{
664 struct pci_mmcfg_region *cfg;
665
666 pci_mmcfg_running_state = true;
667
668 /* If we are not using MMCONFIG, don't insert the resources. */
669 if ((pci_probe & PCI_PROBE_MMCONF) == 0)
670 return 1;
671
672 /*
673 * Attempt to insert the mmcfg resources but not with the busy flag
674 * marked so it won't cause request errors when __request_region is
675 * called.
676 */
677 list_for_each_entry(cfg, &pci_mmcfg_list, list)
678 if (!cfg->res.parent)
679 insert_resource(&iomem_resource, &cfg->res);
680
681 return 0;
682}
683
684/*
685 * Perform MMCONFIG resource insertion after PCI initialization to allow for
686 * misprogrammed MCFG tables that state larger sizes but actually conflict
687 * with other system resources.
688 */
689late_initcall(pci_mmcfg_late_insert_resources);
690
691/* Add MMCFG information for host bridges */
692int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
693 phys_addr_t addr)
694{
695 int rc;
696 struct resource *tmp = NULL;
697 struct pci_mmcfg_region *cfg;
698
699 if (!(pci_probe & PCI_PROBE_MMCONF) || pci_mmcfg_arch_init_failed)
700 return -ENODEV;
701
702 if (start > end)
703 return -EINVAL;
704
705 mutex_lock(&pci_mmcfg_lock);
706 cfg = pci_mmconfig_lookup(seg, start);
707 if (cfg) {
708 if (cfg->end_bus < end)
709 dev_info(dev, FW_INFO
710 "MMCONFIG for "
711 "domain %04x [bus %02x-%02x] "
712 "only partially covers this bridge\n",
713 cfg->segment, cfg->start_bus, cfg->end_bus);
714 mutex_unlock(&pci_mmcfg_lock);
715 return -EEXIST;
716 }
717
718 if (!addr) {
719 mutex_unlock(&pci_mmcfg_lock);
720 return -EINVAL;
721 }
722
723 rc = -EBUSY;
724 cfg = pci_mmconfig_alloc(seg, start, end, addr);
725 if (cfg == NULL) {
726 dev_warn(dev, "fail to add MMCONFIG (out of memory)\n");
727 rc = -ENOMEM;
728 } else if (!pci_mmcfg_check_reserved(dev, cfg, 0)) {
729 dev_warn(dev, FW_BUG "MMCONFIG %pR isn't reserved\n",
730 &cfg->res);
731 } else {
732 /* Insert resource if it's not in boot stage */
733 if (pci_mmcfg_running_state)
734 tmp = insert_resource_conflict(&iomem_resource,
735 &cfg->res);
736
737 if (tmp) {
738 dev_warn(dev,
739 "MMCONFIG %pR conflicts with "
740 "%s %pR\n",
741 &cfg->res, tmp->name, tmp);
742 } else if (pci_mmcfg_arch_map(cfg)) {
743 dev_warn(dev, "fail to map MMCONFIG %pR.\n",
744 &cfg->res);
745 } else {
746 list_add_sorted(cfg);
747 dev_info(dev, "MMCONFIG at %pR (base %#lx)\n",
748 &cfg->res, (unsigned long)addr);
749 cfg = NULL;
750 rc = 0;
751 }
752 }
753
754 if (cfg) {
755 if (cfg->res.parent)
756 release_resource(&cfg->res);
757 kfree(cfg);
758 }
759
760 mutex_unlock(&pci_mmcfg_lock);
761
762 return rc;
763}
764
765/* Delete MMCFG information for host bridges */
766int pci_mmconfig_delete(u16 seg, u8 start, u8 end)
767{
768 struct pci_mmcfg_region *cfg;
769
770 mutex_lock(&pci_mmcfg_lock);
771 list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list)
772 if (cfg->segment == seg && cfg->start_bus == start &&
773 cfg->end_bus == end) {
774 list_del_rcu(&cfg->list);
775 synchronize_rcu();
776 pci_mmcfg_arch_unmap(cfg);
777 if (cfg->res.parent)
778 release_resource(&cfg->res);
779 mutex_unlock(&pci_mmcfg_lock);
780 kfree(cfg);
781 return 0;
782 }
783 mutex_unlock(&pci_mmcfg_lock);
784
785 return -ENOENT;
786}