xref: /linux/arch/x86/pci/mmconfig-shared.c (revision 4949009eb8d40a441dcddcd96e101e77d31cf1b2)
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. */
28 static bool pci_mmcfg_running_state;
29 static bool pci_mmcfg_arch_init_failed;
30 static DEFINE_MUTEX(pci_mmcfg_lock);
31 
32 LIST_HEAD(pci_mmcfg_list);
33 
34 static void __init 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 
42 static void __init 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 
51 static 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 
67 static 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 
96 static struct pci_mmcfg_region *__init 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 
116 struct 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 
128 static 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 
143 static 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 
187 static 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 
237 static bool __initdata mcp55_checked;
238 static 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 __initconst	= 0x90;
244 	static const u32 extcfg_regsize __initconst	= 4;
245 	static const u32 extcfg_enable_mask __initconst	= 1 << 31;
246 	static const u32 extcfg_start_mask __initconst	= 0xff << 16;
247 	static const int extcfg_start_shift __initconst	= 16;
248 	static const u32 extcfg_size_mask __initconst	= 0x3 << 28;
249 	static const int extcfg_size_shift __initconst	= 28;
250 	static const int extcfg_sizebus[] __initconst	= {
251 		0x100, 0x80, 0x40, 0x20
252 	};
253 	static const u32 extcfg_base_mask[] __initconst	= {
254 		0x7ff8, 0x7ffc, 0x7ffe, 0x7fff
255 	};
256 	static const int extcfg_base_lshift __initconst	= 25;
257 
258 	/*
259 	 * do check if amd fam10h already took over
260 	 */
261 	if (!acpi_disabled || !list_empty(&pci_mmcfg_list) || mcp55_checked)
262 		return NULL;
263 
264 	mcp55_checked = true;
265 	for (bus = 0; bus < 256; bus++) {
266 		u64 base;
267 		u32 l, extcfg;
268 		u16 vendor, device;
269 		int start, size_index, end;
270 
271 		raw_pci_ops->read(0, bus, PCI_DEVFN(0, 0), 0, 4, &l);
272 		vendor = l & 0xffff;
273 		device = (l >> 16) & 0xffff;
274 
275 		if (PCI_VENDOR_ID_NVIDIA != vendor || 0x0369 != device)
276 			continue;
277 
278 		raw_pci_ops->read(0, bus, PCI_DEVFN(0, 0), extcfg_regnum,
279 				  extcfg_regsize, &extcfg);
280 
281 		if (!(extcfg & extcfg_enable_mask))
282 			continue;
283 
284 		size_index = (extcfg & extcfg_size_mask) >> extcfg_size_shift;
285 		base = extcfg & extcfg_base_mask[size_index];
286 		/* base could > 4G */
287 		base <<= extcfg_base_lshift;
288 		start = (extcfg & extcfg_start_mask) >> extcfg_start_shift;
289 		end = start + extcfg_sizebus[size_index] - 1;
290 		if (pci_mmconfig_add(0, start, end, base) == NULL)
291 			continue;
292 		mcp55_mmconf_found++;
293 	}
294 
295 	if (!mcp55_mmconf_found)
296 		return NULL;
297 
298 	return "nVidia MCP55";
299 }
300 
301 struct pci_mmcfg_hostbridge_probe {
302 	u32 bus;
303 	u32 devfn;
304 	u32 vendor;
305 	u32 device;
306 	const char *(*probe)(void);
307 };
308 
309 static const struct pci_mmcfg_hostbridge_probe pci_mmcfg_probes[] __initconst = {
310 	{ 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_INTEL,
311 	  PCI_DEVICE_ID_INTEL_E7520_MCH, pci_mmcfg_e7520 },
312 	{ 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_INTEL,
313 	  PCI_DEVICE_ID_INTEL_82945G_HB, pci_mmcfg_intel_945 },
314 	{ 0, PCI_DEVFN(0x18, 0), PCI_VENDOR_ID_AMD,
315 	  0x1200, pci_mmcfg_amd_fam10h },
316 	{ 0xff, PCI_DEVFN(0, 0), PCI_VENDOR_ID_AMD,
317 	  0x1200, pci_mmcfg_amd_fam10h },
318 	{ 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_NVIDIA,
319 	  0x0369, pci_mmcfg_nvidia_mcp55 },
320 };
321 
322 static void __init pci_mmcfg_check_end_bus_number(void)
323 {
324 	struct pci_mmcfg_region *cfg, *cfgx;
325 
326 	/* Fixup overlaps */
327 	list_for_each_entry(cfg, &pci_mmcfg_list, list) {
328 		if (cfg->end_bus < cfg->start_bus)
329 			cfg->end_bus = 255;
330 
331 		/* Don't access the list head ! */
332 		if (cfg->list.next == &pci_mmcfg_list)
333 			break;
334 
335 		cfgx = list_entry(cfg->list.next, typeof(*cfg), list);
336 		if (cfg->end_bus >= cfgx->start_bus)
337 			cfg->end_bus = cfgx->start_bus - 1;
338 	}
339 }
340 
341 static int __init pci_mmcfg_check_hostbridge(void)
342 {
343 	u32 l;
344 	u32 bus, devfn;
345 	u16 vendor, device;
346 	int i;
347 	const char *name;
348 
349 	if (!raw_pci_ops)
350 		return 0;
351 
352 	free_all_mmcfg();
353 
354 	for (i = 0; i < ARRAY_SIZE(pci_mmcfg_probes); i++) {
355 		bus =  pci_mmcfg_probes[i].bus;
356 		devfn = pci_mmcfg_probes[i].devfn;
357 		raw_pci_ops->read(0, bus, devfn, 0, 4, &l);
358 		vendor = l & 0xffff;
359 		device = (l >> 16) & 0xffff;
360 
361 		name = NULL;
362 		if (pci_mmcfg_probes[i].vendor == vendor &&
363 		    pci_mmcfg_probes[i].device == device)
364 			name = pci_mmcfg_probes[i].probe();
365 
366 		if (name)
367 			pr_info(PREFIX "%s with MMCONFIG support\n", name);
368 	}
369 
370 	/* some end_bus_number is crazy, fix it */
371 	pci_mmcfg_check_end_bus_number();
372 
373 	return !list_empty(&pci_mmcfg_list);
374 }
375 
376 static acpi_status check_mcfg_resource(struct acpi_resource *res, void *data)
377 {
378 	struct resource *mcfg_res = data;
379 	struct acpi_resource_address64 address;
380 	acpi_status status;
381 
382 	if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
383 		struct acpi_resource_fixed_memory32 *fixmem32 =
384 			&res->data.fixed_memory32;
385 		if (!fixmem32)
386 			return AE_OK;
387 		if ((mcfg_res->start >= fixmem32->address) &&
388 		    (mcfg_res->end < (fixmem32->address +
389 				      fixmem32->address_length))) {
390 			mcfg_res->flags = 1;
391 			return AE_CTRL_TERMINATE;
392 		}
393 	}
394 	if ((res->type != ACPI_RESOURCE_TYPE_ADDRESS32) &&
395 	    (res->type != ACPI_RESOURCE_TYPE_ADDRESS64))
396 		return AE_OK;
397 
398 	status = acpi_resource_to_address64(res, &address);
399 	if (ACPI_FAILURE(status) ||
400 	   (address.address_length <= 0) ||
401 	   (address.resource_type != ACPI_MEMORY_RANGE))
402 		return AE_OK;
403 
404 	if ((mcfg_res->start >= address.minimum) &&
405 	    (mcfg_res->end < (address.minimum + address.address_length))) {
406 		mcfg_res->flags = 1;
407 		return AE_CTRL_TERMINATE;
408 	}
409 	return AE_OK;
410 }
411 
412 static acpi_status find_mboard_resource(acpi_handle handle, u32 lvl,
413 					void *context, void **rv)
414 {
415 	struct resource *mcfg_res = context;
416 
417 	acpi_walk_resources(handle, METHOD_NAME__CRS,
418 			    check_mcfg_resource, context);
419 
420 	if (mcfg_res->flags)
421 		return AE_CTRL_TERMINATE;
422 
423 	return AE_OK;
424 }
425 
426 static int is_acpi_reserved(u64 start, u64 end, unsigned not_used)
427 {
428 	struct resource mcfg_res;
429 
430 	mcfg_res.start = start;
431 	mcfg_res.end = end - 1;
432 	mcfg_res.flags = 0;
433 
434 	acpi_get_devices("PNP0C01", find_mboard_resource, &mcfg_res, NULL);
435 
436 	if (!mcfg_res.flags)
437 		acpi_get_devices("PNP0C02", find_mboard_resource, &mcfg_res,
438 				 NULL);
439 
440 	return mcfg_res.flags;
441 }
442 
443 typedef int (*check_reserved_t)(u64 start, u64 end, unsigned type);
444 
445 static int __ref is_mmconf_reserved(check_reserved_t is_reserved,
446 				    struct pci_mmcfg_region *cfg,
447 				    struct device *dev, int with_e820)
448 {
449 	u64 addr = cfg->res.start;
450 	u64 size = resource_size(&cfg->res);
451 	u64 old_size = size;
452 	int num_buses;
453 	char *method = with_e820 ? "E820" : "ACPI motherboard resources";
454 
455 	while (!is_reserved(addr, addr + size, E820_RESERVED)) {
456 		size >>= 1;
457 		if (size < (16UL<<20))
458 			break;
459 	}
460 
461 	if (size < (16UL<<20) && size != old_size)
462 		return 0;
463 
464 	if (dev)
465 		dev_info(dev, "MMCONFIG at %pR reserved in %s\n",
466 			 &cfg->res, method);
467 	else
468 		pr_info(PREFIX "MMCONFIG at %pR reserved in %s\n",
469 		       &cfg->res, method);
470 
471 	if (old_size != size) {
472 		/* update end_bus */
473 		cfg->end_bus = cfg->start_bus + ((size>>20) - 1);
474 		num_buses = cfg->end_bus - cfg->start_bus + 1;
475 		cfg->res.end = cfg->res.start +
476 		    PCI_MMCFG_BUS_OFFSET(num_buses) - 1;
477 		snprintf(cfg->name, PCI_MMCFG_RESOURCE_NAME_LEN,
478 			 "PCI MMCONFIG %04x [bus %02x-%02x]",
479 			 cfg->segment, cfg->start_bus, cfg->end_bus);
480 
481 		if (dev)
482 			dev_info(dev,
483 				"MMCONFIG "
484 				"at %pR (base %#lx) (size reduced!)\n",
485 				&cfg->res, (unsigned long) cfg->address);
486 		else
487 			pr_info(PREFIX
488 				"MMCONFIG for %04x [bus%02x-%02x] "
489 				"at %pR (base %#lx) (size reduced!)\n",
490 				cfg->segment, cfg->start_bus, cfg->end_bus,
491 				&cfg->res, (unsigned long) cfg->address);
492 	}
493 
494 	return 1;
495 }
496 
497 static int __ref pci_mmcfg_check_reserved(struct device *dev,
498 		  struct pci_mmcfg_region *cfg, int early)
499 {
500 	if (!early && !acpi_disabled) {
501 		if (is_mmconf_reserved(is_acpi_reserved, cfg, dev, 0))
502 			return 1;
503 
504 		if (dev)
505 			dev_info(dev, FW_INFO
506 				 "MMCONFIG at %pR not reserved in "
507 				 "ACPI motherboard resources\n",
508 				 &cfg->res);
509 		else
510 			pr_info(FW_INFO PREFIX
511 			       "MMCONFIG at %pR not reserved in "
512 			       "ACPI motherboard resources\n",
513 			       &cfg->res);
514 	}
515 
516 	/*
517 	 * e820_all_mapped() is marked as __init.
518 	 * All entries from ACPI MCFG table have been checked at boot time.
519 	 * For MCFG information constructed from hotpluggable host bridge's
520 	 * _CBA method, just assume it's reserved.
521 	 */
522 	if (pci_mmcfg_running_state)
523 		return 1;
524 
525 	/* Don't try to do this check unless configuration
526 	   type 1 is available. how about type 2 ?*/
527 	if (raw_pci_ops)
528 		return is_mmconf_reserved(e820_all_mapped, cfg, dev, 1);
529 
530 	return 0;
531 }
532 
533 static void __init pci_mmcfg_reject_broken(int early)
534 {
535 	struct pci_mmcfg_region *cfg;
536 
537 	list_for_each_entry(cfg, &pci_mmcfg_list, list) {
538 		if (pci_mmcfg_check_reserved(NULL, cfg, early) == 0) {
539 			pr_info(PREFIX "not using MMCONFIG\n");
540 			free_all_mmcfg();
541 			return;
542 		}
543 	}
544 }
545 
546 static int __init acpi_mcfg_check_entry(struct acpi_table_mcfg *mcfg,
547 					struct acpi_mcfg_allocation *cfg)
548 {
549 	int year;
550 
551 	if (cfg->address < 0xFFFFFFFF)
552 		return 0;
553 
554 	if (!strncmp(mcfg->header.oem_id, "SGI", 3))
555 		return 0;
556 
557 	if (mcfg->header.revision >= 1) {
558 		if (dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL) &&
559 		    year >= 2010)
560 			return 0;
561 	}
562 
563 	pr_err(PREFIX "MCFG region for %04x [bus %02x-%02x] at %#llx "
564 	       "is above 4GB, ignored\n", cfg->pci_segment,
565 	       cfg->start_bus_number, cfg->end_bus_number, cfg->address);
566 	return -EINVAL;
567 }
568 
569 static int __init pci_parse_mcfg(struct acpi_table_header *header)
570 {
571 	struct acpi_table_mcfg *mcfg;
572 	struct acpi_mcfg_allocation *cfg_table, *cfg;
573 	unsigned long i;
574 	int entries;
575 
576 	if (!header)
577 		return -EINVAL;
578 
579 	mcfg = (struct acpi_table_mcfg *)header;
580 
581 	/* how many config structures do we have */
582 	free_all_mmcfg();
583 	entries = 0;
584 	i = header->length - sizeof(struct acpi_table_mcfg);
585 	while (i >= sizeof(struct acpi_mcfg_allocation)) {
586 		entries++;
587 		i -= sizeof(struct acpi_mcfg_allocation);
588 	}
589 	if (entries == 0) {
590 		pr_err(PREFIX "MMCONFIG has no entries\n");
591 		return -ENODEV;
592 	}
593 
594 	cfg_table = (struct acpi_mcfg_allocation *) &mcfg[1];
595 	for (i = 0; i < entries; i++) {
596 		cfg = &cfg_table[i];
597 		if (acpi_mcfg_check_entry(mcfg, cfg)) {
598 			free_all_mmcfg();
599 			return -ENODEV;
600 		}
601 
602 		if (pci_mmconfig_add(cfg->pci_segment, cfg->start_bus_number,
603 				   cfg->end_bus_number, cfg->address) == NULL) {
604 			pr_warn(PREFIX "no memory for MCFG entries\n");
605 			free_all_mmcfg();
606 			return -ENOMEM;
607 		}
608 	}
609 
610 	return 0;
611 }
612 
613 static void __init __pci_mmcfg_init(int early)
614 {
615 	pci_mmcfg_reject_broken(early);
616 	if (list_empty(&pci_mmcfg_list))
617 		return;
618 
619 	if (pcibios_last_bus < 0) {
620 		const struct pci_mmcfg_region *cfg;
621 
622 		list_for_each_entry(cfg, &pci_mmcfg_list, list) {
623 			if (cfg->segment)
624 				break;
625 			pcibios_last_bus = cfg->end_bus;
626 		}
627 	}
628 
629 	if (pci_mmcfg_arch_init())
630 		pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
631 	else {
632 		free_all_mmcfg();
633 		pci_mmcfg_arch_init_failed = true;
634 	}
635 }
636 
637 static int __initdata known_bridge;
638 
639 void __init pci_mmcfg_early_init(void)
640 {
641 	if (pci_probe & PCI_PROBE_MMCONF) {
642 		if (pci_mmcfg_check_hostbridge())
643 			known_bridge = 1;
644 		else
645 			acpi_sfi_table_parse(ACPI_SIG_MCFG, pci_parse_mcfg);
646 		__pci_mmcfg_init(1);
647 	}
648 }
649 
650 void __init pci_mmcfg_late_init(void)
651 {
652 	/* MMCONFIG disabled */
653 	if ((pci_probe & PCI_PROBE_MMCONF) == 0)
654 		return;
655 
656 	if (known_bridge)
657 		return;
658 
659 	/* MMCONFIG hasn't been enabled yet, try again */
660 	if (pci_probe & PCI_PROBE_MASK & ~PCI_PROBE_MMCONF) {
661 		acpi_sfi_table_parse(ACPI_SIG_MCFG, pci_parse_mcfg);
662 		__pci_mmcfg_init(0);
663 	}
664 }
665 
666 static int __init pci_mmcfg_late_insert_resources(void)
667 {
668 	struct pci_mmcfg_region *cfg;
669 
670 	pci_mmcfg_running_state = true;
671 
672 	/* If we are not using MMCONFIG, don't insert the resources. */
673 	if ((pci_probe & PCI_PROBE_MMCONF) == 0)
674 		return 1;
675 
676 	/*
677 	 * Attempt to insert the mmcfg resources but not with the busy flag
678 	 * marked so it won't cause request errors when __request_region is
679 	 * called.
680 	 */
681 	list_for_each_entry(cfg, &pci_mmcfg_list, list)
682 		if (!cfg->res.parent)
683 			insert_resource(&iomem_resource, &cfg->res);
684 
685 	return 0;
686 }
687 
688 /*
689  * Perform MMCONFIG resource insertion after PCI initialization to allow for
690  * misprogrammed MCFG tables that state larger sizes but actually conflict
691  * with other system resources.
692  */
693 late_initcall(pci_mmcfg_late_insert_resources);
694 
695 /* Add MMCFG information for host bridges */
696 int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
697 			phys_addr_t addr)
698 {
699 	int rc;
700 	struct resource *tmp = NULL;
701 	struct pci_mmcfg_region *cfg;
702 
703 	if (!(pci_probe & PCI_PROBE_MMCONF) || pci_mmcfg_arch_init_failed)
704 		return -ENODEV;
705 
706 	if (start > end)
707 		return -EINVAL;
708 
709 	mutex_lock(&pci_mmcfg_lock);
710 	cfg = pci_mmconfig_lookup(seg, start);
711 	if (cfg) {
712 		if (cfg->end_bus < end)
713 			dev_info(dev, FW_INFO
714 				 "MMCONFIG for "
715 				 "domain %04x [bus %02x-%02x] "
716 				 "only partially covers this bridge\n",
717 				  cfg->segment, cfg->start_bus, cfg->end_bus);
718 		mutex_unlock(&pci_mmcfg_lock);
719 		return -EEXIST;
720 	}
721 
722 	if (!addr) {
723 		mutex_unlock(&pci_mmcfg_lock);
724 		return -EINVAL;
725 	}
726 
727 	rc = -EBUSY;
728 	cfg = pci_mmconfig_alloc(seg, start, end, addr);
729 	if (cfg == NULL) {
730 		dev_warn(dev, "fail to add MMCONFIG (out of memory)\n");
731 		rc = -ENOMEM;
732 	} else if (!pci_mmcfg_check_reserved(dev, cfg, 0)) {
733 		dev_warn(dev, FW_BUG "MMCONFIG %pR isn't reserved\n",
734 			 &cfg->res);
735 	} else {
736 		/* Insert resource if it's not in boot stage */
737 		if (pci_mmcfg_running_state)
738 			tmp = insert_resource_conflict(&iomem_resource,
739 						       &cfg->res);
740 
741 		if (tmp) {
742 			dev_warn(dev,
743 				 "MMCONFIG %pR conflicts with "
744 				 "%s %pR\n",
745 				 &cfg->res, tmp->name, tmp);
746 		} else if (pci_mmcfg_arch_map(cfg)) {
747 			dev_warn(dev, "fail to map MMCONFIG %pR.\n",
748 				 &cfg->res);
749 		} else {
750 			list_add_sorted(cfg);
751 			dev_info(dev, "MMCONFIG at %pR (base %#lx)\n",
752 				 &cfg->res, (unsigned long)addr);
753 			cfg = NULL;
754 			rc = 0;
755 		}
756 	}
757 
758 	if (cfg) {
759 		if (cfg->res.parent)
760 			release_resource(&cfg->res);
761 		kfree(cfg);
762 	}
763 
764 	mutex_unlock(&pci_mmcfg_lock);
765 
766 	return rc;
767 }
768 
769 /* Delete MMCFG information for host bridges */
770 int pci_mmconfig_delete(u16 seg, u8 start, u8 end)
771 {
772 	struct pci_mmcfg_region *cfg;
773 
774 	mutex_lock(&pci_mmcfg_lock);
775 	list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list)
776 		if (cfg->segment == seg && cfg->start_bus == start &&
777 		    cfg->end_bus == end) {
778 			list_del_rcu(&cfg->list);
779 			synchronize_rcu();
780 			pci_mmcfg_arch_unmap(cfg);
781 			if (cfg->res.parent)
782 				release_resource(&cfg->res);
783 			mutex_unlock(&pci_mmcfg_lock);
784 			kfree(cfg);
785 			return 0;
786 		}
787 	mutex_unlock(&pci_mmcfg_lock);
788 
789 	return -ENOENT;
790 }
791