xref: /openbmc/linux/arch/x86/pci/mmconfig-shared.c (revision 79f08d9e)
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 <linux/mutex.h>
21 #include <linux/rculist.h>
22 #include <asm/e820.h>
23 #include <asm/pci_x86.h>
24 #include <asm/acpi.h>
25 
26 #define PREFIX "PCI: "
27 
28 /* Indicate if the mmcfg resources have been placed into the resource table. */
29 static bool pci_mmcfg_running_state;
30 static bool pci_mmcfg_arch_init_failed;
31 static DEFINE_MUTEX(pci_mmcfg_lock);
32 
33 LIST_HEAD(pci_mmcfg_list);
34 
35 static __init void pci_mmconfig_remove(struct pci_mmcfg_region *cfg)
36 {
37 	if (cfg->res.parent)
38 		release_resource(&cfg->res);
39 	list_del(&cfg->list);
40 	kfree(cfg);
41 }
42 
43 static __init void free_all_mmcfg(void)
44 {
45 	struct pci_mmcfg_region *cfg, *tmp;
46 
47 	pci_mmcfg_arch_free();
48 	list_for_each_entry_safe(cfg, tmp, &pci_mmcfg_list, list)
49 		pci_mmconfig_remove(cfg);
50 }
51 
52 static void list_add_sorted(struct pci_mmcfg_region *new)
53 {
54 	struct pci_mmcfg_region *cfg;
55 
56 	/* keep list sorted by segment and starting bus number */
57 	list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list) {
58 		if (cfg->segment > new->segment ||
59 		    (cfg->segment == new->segment &&
60 		     cfg->start_bus >= new->start_bus)) {
61 			list_add_tail_rcu(&new->list, &cfg->list);
62 			return;
63 		}
64 	}
65 	list_add_tail_rcu(&new->list, &pci_mmcfg_list);
66 }
67 
68 static struct pci_mmcfg_region *pci_mmconfig_alloc(int segment, int start,
69 						   int end, u64 addr)
70 {
71 	struct pci_mmcfg_region *new;
72 	struct resource *res;
73 
74 	if (addr == 0)
75 		return NULL;
76 
77 	new = kzalloc(sizeof(*new), GFP_KERNEL);
78 	if (!new)
79 		return NULL;
80 
81 	new->address = addr;
82 	new->segment = segment;
83 	new->start_bus = start;
84 	new->end_bus = end;
85 
86 	res = &new->res;
87 	res->start = addr + PCI_MMCFG_BUS_OFFSET(start);
88 	res->end = addr + PCI_MMCFG_BUS_OFFSET(end + 1) - 1;
89 	res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
90 	snprintf(new->name, PCI_MMCFG_RESOURCE_NAME_LEN,
91 		 "PCI MMCONFIG %04x [bus %02x-%02x]", segment, start, end);
92 	res->name = new->name;
93 
94 	return new;
95 }
96 
97 static __init struct pci_mmcfg_region *pci_mmconfig_add(int segment, int start,
98 							int end, u64 addr)
99 {
100 	struct pci_mmcfg_region *new;
101 
102 	new = pci_mmconfig_alloc(segment, start, end, addr);
103 	if (new) {
104 		mutex_lock(&pci_mmcfg_lock);
105 		list_add_sorted(new);
106 		mutex_unlock(&pci_mmcfg_lock);
107 
108 		pr_info(PREFIX
109 		       "MMCONFIG for domain %04x [bus %02x-%02x] at %pR "
110 		       "(base %#lx)\n",
111 		       segment, start, end, &new->res, (unsigned long)addr);
112 	}
113 
114 	return new;
115 }
116 
117 struct pci_mmcfg_region *pci_mmconfig_lookup(int segment, int bus)
118 {
119 	struct pci_mmcfg_region *cfg;
120 
121 	list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list)
122 		if (cfg->segment == segment &&
123 		    cfg->start_bus <= bus && bus <= cfg->end_bus)
124 			return cfg;
125 
126 	return NULL;
127 }
128 
129 static const char __init *pci_mmcfg_e7520(void)
130 {
131 	u32 win;
132 	raw_pci_ops->read(0, 0, PCI_DEVFN(0, 0), 0xce, 2, &win);
133 
134 	win = win & 0xf000;
135 	if (win == 0x0000 || win == 0xf000)
136 		return NULL;
137 
138 	if (pci_mmconfig_add(0, 0, 255, win << 16) == NULL)
139 		return NULL;
140 
141 	return "Intel Corporation E7520 Memory Controller Hub";
142 }
143 
144 static const char __init *pci_mmcfg_intel_945(void)
145 {
146 	u32 pciexbar, mask = 0, len = 0;
147 
148 	raw_pci_ops->read(0, 0, PCI_DEVFN(0, 0), 0x48, 4, &pciexbar);
149 
150 	/* Enable bit */
151 	if (!(pciexbar & 1))
152 		return NULL;
153 
154 	/* Size bits */
155 	switch ((pciexbar >> 1) & 3) {
156 	case 0:
157 		mask = 0xf0000000U;
158 		len  = 0x10000000U;
159 		break;
160 	case 1:
161 		mask = 0xf8000000U;
162 		len  = 0x08000000U;
163 		break;
164 	case 2:
165 		mask = 0xfc000000U;
166 		len  = 0x04000000U;
167 		break;
168 	default:
169 		return NULL;
170 	}
171 
172 	/* Errata #2, things break when not aligned on a 256Mb boundary */
173 	/* Can only happen in 64M/128M mode */
174 
175 	if ((pciexbar & mask) & 0x0fffffffU)
176 		return NULL;
177 
178 	/* Don't hit the APIC registers and their friends */
179 	if ((pciexbar & mask) >= 0xf0000000U)
180 		return NULL;
181 
182 	if (pci_mmconfig_add(0, 0, (len >> 20) - 1, pciexbar & mask) == NULL)
183 		return NULL;
184 
185 	return "Intel Corporation 945G/GZ/P/PL Express Memory Controller Hub";
186 }
187 
188 static const char __init *pci_mmcfg_amd_fam10h(void)
189 {
190 	u32 low, high, address;
191 	u64 base, msr;
192 	int i;
193 	unsigned segnbits = 0, busnbits, end_bus;
194 
195 	if (!(pci_probe & PCI_CHECK_ENABLE_AMD_MMCONF))
196 		return NULL;
197 
198 	address = MSR_FAM10H_MMIO_CONF_BASE;
199 	if (rdmsr_safe(address, &low, &high))
200 		return NULL;
201 
202 	msr = high;
203 	msr <<= 32;
204 	msr |= low;
205 
206 	/* mmconfig is not enable */
207 	if (!(msr & FAM10H_MMIO_CONF_ENABLE))
208 		return NULL;
209 
210 	base = msr & (FAM10H_MMIO_CONF_BASE_MASK<<FAM10H_MMIO_CONF_BASE_SHIFT);
211 
212 	busnbits = (msr >> FAM10H_MMIO_CONF_BUSRANGE_SHIFT) &
213 			 FAM10H_MMIO_CONF_BUSRANGE_MASK;
214 
215 	/*
216 	 * only handle bus 0 ?
217 	 * need to skip it
218 	 */
219 	if (!busnbits)
220 		return NULL;
221 
222 	if (busnbits > 8) {
223 		segnbits = busnbits - 8;
224 		busnbits = 8;
225 	}
226 
227 	end_bus = (1 << busnbits) - 1;
228 	for (i = 0; i < (1 << segnbits); i++)
229 		if (pci_mmconfig_add(i, 0, end_bus,
230 				     base + (1<<28) * i) == NULL) {
231 			free_all_mmcfg();
232 			return NULL;
233 		}
234 
235 	return "AMD Family 10h NB";
236 }
237 
238 static bool __initdata mcp55_checked;
239 static const char __init *pci_mmcfg_nvidia_mcp55(void)
240 {
241 	int bus;
242 	int mcp55_mmconf_found = 0;
243 
244 	static const u32 extcfg_regnum		= 0x90;
245 	static const u32 extcfg_regsize		= 4;
246 	static const u32 extcfg_enable_mask	= 1<<31;
247 	static const u32 extcfg_start_mask	= 0xff<<16;
248 	static const int extcfg_start_shift	= 16;
249 	static const u32 extcfg_size_mask	= 0x3<<28;
250 	static const int extcfg_size_shift	= 28;
251 	static const int extcfg_sizebus[]	= {0x100, 0x80, 0x40, 0x20};
252 	static const u32 extcfg_base_mask[]	= {0x7ff8, 0x7ffc, 0x7ffe, 0x7fff};
253 	static const int extcfg_base_lshift	= 25;
254 
255 	/*
256 	 * do check if amd fam10h already took over
257 	 */
258 	if (!acpi_disabled || !list_empty(&pci_mmcfg_list) || mcp55_checked)
259 		return NULL;
260 
261 	mcp55_checked = true;
262 	for (bus = 0; bus < 256; bus++) {
263 		u64 base;
264 		u32 l, extcfg;
265 		u16 vendor, device;
266 		int start, size_index, end;
267 
268 		raw_pci_ops->read(0, bus, PCI_DEVFN(0, 0), 0, 4, &l);
269 		vendor = l & 0xffff;
270 		device = (l >> 16) & 0xffff;
271 
272 		if (PCI_VENDOR_ID_NVIDIA != vendor || 0x0369 != device)
273 			continue;
274 
275 		raw_pci_ops->read(0, bus, PCI_DEVFN(0, 0), extcfg_regnum,
276 				  extcfg_regsize, &extcfg);
277 
278 		if (!(extcfg & extcfg_enable_mask))
279 			continue;
280 
281 		size_index = (extcfg & extcfg_size_mask) >> extcfg_size_shift;
282 		base = extcfg & extcfg_base_mask[size_index];
283 		/* base could > 4G */
284 		base <<= extcfg_base_lshift;
285 		start = (extcfg & extcfg_start_mask) >> extcfg_start_shift;
286 		end = start + extcfg_sizebus[size_index] - 1;
287 		if (pci_mmconfig_add(0, start, end, base) == NULL)
288 			continue;
289 		mcp55_mmconf_found++;
290 	}
291 
292 	if (!mcp55_mmconf_found)
293 		return NULL;
294 
295 	return "nVidia MCP55";
296 }
297 
298 struct pci_mmcfg_hostbridge_probe {
299 	u32 bus;
300 	u32 devfn;
301 	u32 vendor;
302 	u32 device;
303 	const char *(*probe)(void);
304 };
305 
306 static struct pci_mmcfg_hostbridge_probe pci_mmcfg_probes[] __initdata = {
307 	{ 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_INTEL,
308 	  PCI_DEVICE_ID_INTEL_E7520_MCH, pci_mmcfg_e7520 },
309 	{ 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_INTEL,
310 	  PCI_DEVICE_ID_INTEL_82945G_HB, pci_mmcfg_intel_945 },
311 	{ 0, PCI_DEVFN(0x18, 0), PCI_VENDOR_ID_AMD,
312 	  0x1200, pci_mmcfg_amd_fam10h },
313 	{ 0xff, PCI_DEVFN(0, 0), PCI_VENDOR_ID_AMD,
314 	  0x1200, pci_mmcfg_amd_fam10h },
315 	{ 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_NVIDIA,
316 	  0x0369, pci_mmcfg_nvidia_mcp55 },
317 };
318 
319 static void __init pci_mmcfg_check_end_bus_number(void)
320 {
321 	struct pci_mmcfg_region *cfg, *cfgx;
322 
323 	/* Fixup overlaps */
324 	list_for_each_entry(cfg, &pci_mmcfg_list, list) {
325 		if (cfg->end_bus < cfg->start_bus)
326 			cfg->end_bus = 255;
327 
328 		/* Don't access the list head ! */
329 		if (cfg->list.next == &pci_mmcfg_list)
330 			break;
331 
332 		cfgx = list_entry(cfg->list.next, typeof(*cfg), list);
333 		if (cfg->end_bus >= cfgx->start_bus)
334 			cfg->end_bus = cfgx->start_bus - 1;
335 	}
336 }
337 
338 static int __init pci_mmcfg_check_hostbridge(void)
339 {
340 	u32 l;
341 	u32 bus, devfn;
342 	u16 vendor, device;
343 	int i;
344 	const char *name;
345 
346 	if (!raw_pci_ops)
347 		return 0;
348 
349 	free_all_mmcfg();
350 
351 	for (i = 0; i < ARRAY_SIZE(pci_mmcfg_probes); i++) {
352 		bus =  pci_mmcfg_probes[i].bus;
353 		devfn = pci_mmcfg_probes[i].devfn;
354 		raw_pci_ops->read(0, bus, devfn, 0, 4, &l);
355 		vendor = l & 0xffff;
356 		device = (l >> 16) & 0xffff;
357 
358 		name = NULL;
359 		if (pci_mmcfg_probes[i].vendor == vendor &&
360 		    pci_mmcfg_probes[i].device == device)
361 			name = pci_mmcfg_probes[i].probe();
362 
363 		if (name)
364 			pr_info(PREFIX "%s with MMCONFIG support\n", name);
365 	}
366 
367 	/* some end_bus_number is crazy, fix it */
368 	pci_mmcfg_check_end_bus_number();
369 
370 	return !list_empty(&pci_mmcfg_list);
371 }
372 
373 static acpi_status check_mcfg_resource(struct acpi_resource *res, void *data)
374 {
375 	struct resource *mcfg_res = data;
376 	struct acpi_resource_address64 address;
377 	acpi_status status;
378 
379 	if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
380 		struct acpi_resource_fixed_memory32 *fixmem32 =
381 			&res->data.fixed_memory32;
382 		if (!fixmem32)
383 			return AE_OK;
384 		if ((mcfg_res->start >= fixmem32->address) &&
385 		    (mcfg_res->end < (fixmem32->address +
386 				      fixmem32->address_length))) {
387 			mcfg_res->flags = 1;
388 			return AE_CTRL_TERMINATE;
389 		}
390 	}
391 	if ((res->type != ACPI_RESOURCE_TYPE_ADDRESS32) &&
392 	    (res->type != ACPI_RESOURCE_TYPE_ADDRESS64))
393 		return AE_OK;
394 
395 	status = acpi_resource_to_address64(res, &address);
396 	if (ACPI_FAILURE(status) ||
397 	   (address.address_length <= 0) ||
398 	   (address.resource_type != ACPI_MEMORY_RANGE))
399 		return AE_OK;
400 
401 	if ((mcfg_res->start >= address.minimum) &&
402 	    (mcfg_res->end < (address.minimum + address.address_length))) {
403 		mcfg_res->flags = 1;
404 		return AE_CTRL_TERMINATE;
405 	}
406 	return AE_OK;
407 }
408 
409 static acpi_status find_mboard_resource(acpi_handle handle, u32 lvl,
410 					void *context, void **rv)
411 {
412 	struct resource *mcfg_res = context;
413 
414 	acpi_walk_resources(handle, METHOD_NAME__CRS,
415 			    check_mcfg_resource, context);
416 
417 	if (mcfg_res->flags)
418 		return AE_CTRL_TERMINATE;
419 
420 	return AE_OK;
421 }
422 
423 static int is_acpi_reserved(u64 start, u64 end, unsigned not_used)
424 {
425 	struct resource mcfg_res;
426 
427 	mcfg_res.start = start;
428 	mcfg_res.end = end - 1;
429 	mcfg_res.flags = 0;
430 
431 	acpi_get_devices("PNP0C01", find_mboard_resource, &mcfg_res, NULL);
432 
433 	if (!mcfg_res.flags)
434 		acpi_get_devices("PNP0C02", find_mboard_resource, &mcfg_res,
435 				 NULL);
436 
437 	return mcfg_res.flags;
438 }
439 
440 typedef int (*check_reserved_t)(u64 start, u64 end, unsigned type);
441 
442 static int __ref is_mmconf_reserved(check_reserved_t is_reserved,
443 				    struct pci_mmcfg_region *cfg,
444 				    struct device *dev, int with_e820)
445 {
446 	u64 addr = cfg->res.start;
447 	u64 size = resource_size(&cfg->res);
448 	u64 old_size = size;
449 	int num_buses;
450 	char *method = with_e820 ? "E820" : "ACPI motherboard resources";
451 
452 	while (!is_reserved(addr, addr + size, E820_RESERVED)) {
453 		size >>= 1;
454 		if (size < (16UL<<20))
455 			break;
456 	}
457 
458 	if (size < (16UL<<20) && size != old_size)
459 		return 0;
460 
461 	if (dev)
462 		dev_info(dev, "MMCONFIG at %pR reserved in %s\n",
463 			 &cfg->res, method);
464 	else
465 		pr_info(PREFIX "MMCONFIG at %pR reserved in %s\n",
466 		       &cfg->res, method);
467 
468 	if (old_size != size) {
469 		/* update end_bus */
470 		cfg->end_bus = cfg->start_bus + ((size>>20) - 1);
471 		num_buses = cfg->end_bus - cfg->start_bus + 1;
472 		cfg->res.end = cfg->res.start +
473 		    PCI_MMCFG_BUS_OFFSET(num_buses) - 1;
474 		snprintf(cfg->name, PCI_MMCFG_RESOURCE_NAME_LEN,
475 			 "PCI MMCONFIG %04x [bus %02x-%02x]",
476 			 cfg->segment, cfg->start_bus, cfg->end_bus);
477 
478 		if (dev)
479 			dev_info(dev,
480 				"MMCONFIG "
481 				"at %pR (base %#lx) (size reduced!)\n",
482 				&cfg->res, (unsigned long) cfg->address);
483 		else
484 			pr_info(PREFIX
485 				"MMCONFIG for %04x [bus%02x-%02x] "
486 				"at %pR (base %#lx) (size reduced!)\n",
487 				cfg->segment, cfg->start_bus, cfg->end_bus,
488 				&cfg->res, (unsigned long) cfg->address);
489 	}
490 
491 	return 1;
492 }
493 
494 static int __ref pci_mmcfg_check_reserved(struct device *dev,
495 		  struct pci_mmcfg_region *cfg, int early)
496 {
497 	if (!early && !acpi_disabled) {
498 		if (is_mmconf_reserved(is_acpi_reserved, cfg, dev, 0))
499 			return 1;
500 
501 		if (dev)
502 			dev_info(dev, FW_INFO
503 				 "MMCONFIG at %pR not reserved in "
504 				 "ACPI motherboard resources\n",
505 				 &cfg->res);
506 		else
507 			pr_info(FW_INFO PREFIX
508 			       "MMCONFIG at %pR not reserved in "
509 			       "ACPI motherboard resources\n",
510 			       &cfg->res);
511 	}
512 
513 	/*
514 	 * e820_all_mapped() is marked as __init.
515 	 * All entries from ACPI MCFG table have been checked at boot time.
516 	 * For MCFG information constructed from hotpluggable host bridge's
517 	 * _CBA method, just assume it's reserved.
518 	 */
519 	if (pci_mmcfg_running_state)
520 		return 1;
521 
522 	/* Don't try to do this check unless configuration
523 	   type 1 is available. how about type 2 ?*/
524 	if (raw_pci_ops)
525 		return is_mmconf_reserved(e820_all_mapped, cfg, dev, 1);
526 
527 	return 0;
528 }
529 
530 static void __init pci_mmcfg_reject_broken(int early)
531 {
532 	struct pci_mmcfg_region *cfg;
533 
534 	list_for_each_entry(cfg, &pci_mmcfg_list, list) {
535 		if (pci_mmcfg_check_reserved(NULL, cfg, early) == 0) {
536 			pr_info(PREFIX "not using MMCONFIG\n");
537 			free_all_mmcfg();
538 			return;
539 		}
540 	}
541 }
542 
543 static int __init acpi_mcfg_check_entry(struct acpi_table_mcfg *mcfg,
544 					struct acpi_mcfg_allocation *cfg)
545 {
546 	int year;
547 
548 	if (cfg->address < 0xFFFFFFFF)
549 		return 0;
550 
551 	if (!strncmp(mcfg->header.oem_id, "SGI", 3))
552 		return 0;
553 
554 	if (mcfg->header.revision >= 1) {
555 		if (dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL) &&
556 		    year >= 2010)
557 			return 0;
558 	}
559 
560 	pr_err(PREFIX "MCFG region for %04x [bus %02x-%02x] at %#llx "
561 	       "is above 4GB, ignored\n", cfg->pci_segment,
562 	       cfg->start_bus_number, cfg->end_bus_number, cfg->address);
563 	return -EINVAL;
564 }
565 
566 static int __init pci_parse_mcfg(struct acpi_table_header *header)
567 {
568 	struct acpi_table_mcfg *mcfg;
569 	struct acpi_mcfg_allocation *cfg_table, *cfg;
570 	unsigned long i;
571 	int entries;
572 
573 	if (!header)
574 		return -EINVAL;
575 
576 	mcfg = (struct acpi_table_mcfg *)header;
577 
578 	/* how many config structures do we have */
579 	free_all_mmcfg();
580 	entries = 0;
581 	i = header->length - sizeof(struct acpi_table_mcfg);
582 	while (i >= sizeof(struct acpi_mcfg_allocation)) {
583 		entries++;
584 		i -= sizeof(struct acpi_mcfg_allocation);
585 	}
586 	if (entries == 0) {
587 		pr_err(PREFIX "MMCONFIG has no entries\n");
588 		return -ENODEV;
589 	}
590 
591 	cfg_table = (struct acpi_mcfg_allocation *) &mcfg[1];
592 	for (i = 0; i < entries; i++) {
593 		cfg = &cfg_table[i];
594 		if (acpi_mcfg_check_entry(mcfg, cfg)) {
595 			free_all_mmcfg();
596 			return -ENODEV;
597 		}
598 
599 		if (pci_mmconfig_add(cfg->pci_segment, cfg->start_bus_number,
600 				   cfg->end_bus_number, cfg->address) == NULL) {
601 			pr_warn(PREFIX "no memory for MCFG entries\n");
602 			free_all_mmcfg();
603 			return -ENOMEM;
604 		}
605 	}
606 
607 	return 0;
608 }
609 
610 static void __init __pci_mmcfg_init(int early)
611 {
612 	pci_mmcfg_reject_broken(early);
613 	if (list_empty(&pci_mmcfg_list))
614 		return;
615 
616 	if (pcibios_last_bus < 0) {
617 		const struct pci_mmcfg_region *cfg;
618 
619 		list_for_each_entry(cfg, &pci_mmcfg_list, list) {
620 			if (cfg->segment)
621 				break;
622 			pcibios_last_bus = cfg->end_bus;
623 		}
624 	}
625 
626 	if (pci_mmcfg_arch_init())
627 		pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
628 	else {
629 		free_all_mmcfg();
630 		pci_mmcfg_arch_init_failed = true;
631 	}
632 }
633 
634 static int __initdata known_bridge;
635 
636 void __init pci_mmcfg_early_init(void)
637 {
638 	if (pci_probe & PCI_PROBE_MMCONF) {
639 		if (pci_mmcfg_check_hostbridge())
640 			known_bridge = 1;
641 		else
642 			acpi_sfi_table_parse(ACPI_SIG_MCFG, pci_parse_mcfg);
643 		__pci_mmcfg_init(1);
644 	}
645 }
646 
647 void __init pci_mmcfg_late_init(void)
648 {
649 	/* MMCONFIG disabled */
650 	if ((pci_probe & PCI_PROBE_MMCONF) == 0)
651 		return;
652 
653 	if (known_bridge)
654 		return;
655 
656 	/* MMCONFIG hasn't been enabled yet, try again */
657 	if (pci_probe & PCI_PROBE_MASK & ~PCI_PROBE_MMCONF) {
658 		acpi_sfi_table_parse(ACPI_SIG_MCFG, pci_parse_mcfg);
659 		__pci_mmcfg_init(0);
660 	}
661 }
662 
663 static int __init pci_mmcfg_late_insert_resources(void)
664 {
665 	struct pci_mmcfg_region *cfg;
666 
667 	pci_mmcfg_running_state = true;
668 
669 	/* If we are not using MMCONFIG, don't insert the resources. */
670 	if ((pci_probe & PCI_PROBE_MMCONF) == 0)
671 		return 1;
672 
673 	/*
674 	 * Attempt to insert the mmcfg resources but not with the busy flag
675 	 * marked so it won't cause request errors when __request_region is
676 	 * called.
677 	 */
678 	list_for_each_entry(cfg, &pci_mmcfg_list, list)
679 		if (!cfg->res.parent)
680 			insert_resource(&iomem_resource, &cfg->res);
681 
682 	return 0;
683 }
684 
685 /*
686  * Perform MMCONFIG resource insertion after PCI initialization to allow for
687  * misprogrammed MCFG tables that state larger sizes but actually conflict
688  * with other system resources.
689  */
690 late_initcall(pci_mmcfg_late_insert_resources);
691 
692 /* Add MMCFG information for host bridges */
693 int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
694 			phys_addr_t addr)
695 {
696 	int rc;
697 	struct resource *tmp = NULL;
698 	struct pci_mmcfg_region *cfg;
699 
700 	if (!(pci_probe & PCI_PROBE_MMCONF) || pci_mmcfg_arch_init_failed)
701 		return -ENODEV;
702 
703 	if (start > end)
704 		return -EINVAL;
705 
706 	mutex_lock(&pci_mmcfg_lock);
707 	cfg = pci_mmconfig_lookup(seg, start);
708 	if (cfg) {
709 		if (cfg->end_bus < end)
710 			dev_info(dev, FW_INFO
711 				 "MMCONFIG for "
712 				 "domain %04x [bus %02x-%02x] "
713 				 "only partially covers this bridge\n",
714 				  cfg->segment, cfg->start_bus, cfg->end_bus);
715 		mutex_unlock(&pci_mmcfg_lock);
716 		return -EEXIST;
717 	}
718 
719 	if (!addr) {
720 		mutex_unlock(&pci_mmcfg_lock);
721 		return -EINVAL;
722 	}
723 
724 	rc = -EBUSY;
725 	cfg = pci_mmconfig_alloc(seg, start, end, addr);
726 	if (cfg == NULL) {
727 		dev_warn(dev, "fail to add MMCONFIG (out of memory)\n");
728 		rc = -ENOMEM;
729 	} else if (!pci_mmcfg_check_reserved(dev, cfg, 0)) {
730 		dev_warn(dev, FW_BUG "MMCONFIG %pR isn't reserved\n",
731 			 &cfg->res);
732 	} else {
733 		/* Insert resource if it's not in boot stage */
734 		if (pci_mmcfg_running_state)
735 			tmp = insert_resource_conflict(&iomem_resource,
736 						       &cfg->res);
737 
738 		if (tmp) {
739 			dev_warn(dev,
740 				 "MMCONFIG %pR conflicts with "
741 				 "%s %pR\n",
742 				 &cfg->res, tmp->name, tmp);
743 		} else if (pci_mmcfg_arch_map(cfg)) {
744 			dev_warn(dev, "fail to map MMCONFIG %pR.\n",
745 				 &cfg->res);
746 		} else {
747 			list_add_sorted(cfg);
748 			dev_info(dev, "MMCONFIG at %pR (base %#lx)\n",
749 				 &cfg->res, (unsigned long)addr);
750 			cfg = NULL;
751 			rc = 0;
752 		}
753 	}
754 
755 	if (cfg) {
756 		if (cfg->res.parent)
757 			release_resource(&cfg->res);
758 		kfree(cfg);
759 	}
760 
761 	mutex_unlock(&pci_mmcfg_lock);
762 
763 	return rc;
764 }
765 
766 /* Delete MMCFG information for host bridges */
767 int pci_mmconfig_delete(u16 seg, u8 start, u8 end)
768 {
769 	struct pci_mmcfg_region *cfg;
770 
771 	mutex_lock(&pci_mmcfg_lock);
772 	list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list)
773 		if (cfg->segment == seg && cfg->start_bus == start &&
774 		    cfg->end_bus == end) {
775 			list_del_rcu(&cfg->list);
776 			synchronize_rcu();
777 			pci_mmcfg_arch_unmap(cfg);
778 			if (cfg->res.parent)
779 				release_resource(&cfg->res);
780 			mutex_unlock(&pci_mmcfg_lock);
781 			kfree(cfg);
782 			return 0;
783 		}
784 	mutex_unlock(&pci_mmcfg_lock);
785 
786 	return -ENOENT;
787 }
788