xref: /openbmc/linux/arch/x86/pci/mmconfig-shared.c (revision fe4549b1)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * mmconfig-shared.c - Low-level direct PCI config space access via
4  *                     MMCONFIG - common code between i386 and x86-64.
5  *
6  * This code does:
7  * - known chipset handling
8  * - ACPI decoding and validation
9  *
10  * Per-architecture code takes care of the mappings and accesses
11  * themselves.
12  */
13 
14 #include <linux/acpi.h>
15 #include <linux/efi.h>
16 #include <linux/pci.h>
17 #include <linux/init.h>
18 #include <linux/bitmap.h>
19 #include <linux/dmi.h>
20 #include <linux/slab.h>
21 #include <linux/mutex.h>
22 #include <linux/rculist.h>
23 #include <asm/e820/api.h>
24 #include <asm/pci_x86.h>
25 #include <asm/acpi.h>
26 
27 #define PREFIX "PCI: "
28 
29 /* Indicate if the mmcfg resources have been placed into the resource table. */
30 static bool pci_mmcfg_running_state;
31 static bool pci_mmcfg_arch_init_failed;
32 static DEFINE_MUTEX(pci_mmcfg_lock);
33 #define pci_mmcfg_lock_held() lock_is_held(&(pci_mmcfg_lock).dep_map)
34 
35 LIST_HEAD(pci_mmcfg_list);
36 
37 static void __init pci_mmconfig_remove(struct pci_mmcfg_region *cfg)
38 {
39 	if (cfg->res.parent)
40 		release_resource(&cfg->res);
41 	list_del(&cfg->list);
42 	kfree(cfg);
43 }
44 
45 static void __init free_all_mmcfg(void)
46 {
47 	struct pci_mmcfg_region *cfg, *tmp;
48 
49 	pci_mmcfg_arch_free();
50 	list_for_each_entry_safe(cfg, tmp, &pci_mmcfg_list, list)
51 		pci_mmconfig_remove(cfg);
52 }
53 
54 static void list_add_sorted(struct pci_mmcfg_region *new)
55 {
56 	struct pci_mmcfg_region *cfg;
57 
58 	/* keep list sorted by segment and starting bus number */
59 	list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list, pci_mmcfg_lock_held()) {
60 		if (cfg->segment > new->segment ||
61 		    (cfg->segment == new->segment &&
62 		     cfg->start_bus >= new->start_bus)) {
63 			list_add_tail_rcu(&new->list, &cfg->list);
64 			return;
65 		}
66 	}
67 	list_add_tail_rcu(&new->list, &pci_mmcfg_list);
68 }
69 
70 static struct pci_mmcfg_region *pci_mmconfig_alloc(int segment, int start,
71 						   int end, u64 addr)
72 {
73 	struct pci_mmcfg_region *new;
74 	struct resource *res;
75 
76 	if (addr == 0)
77 		return NULL;
78 
79 	new = kzalloc(sizeof(*new), GFP_KERNEL);
80 	if (!new)
81 		return NULL;
82 
83 	new->address = addr;
84 	new->segment = segment;
85 	new->start_bus = start;
86 	new->end_bus = end;
87 
88 	res = &new->res;
89 	res->start = addr + PCI_MMCFG_BUS_OFFSET(start);
90 	res->end = addr + PCI_MMCFG_BUS_OFFSET(end + 1) - 1;
91 	res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
92 	snprintf(new->name, PCI_MMCFG_RESOURCE_NAME_LEN,
93 		 "PCI MMCONFIG %04x [bus %02x-%02x]", segment, start, end);
94 	res->name = new->name;
95 
96 	return new;
97 }
98 
99 struct pci_mmcfg_region *__init pci_mmconfig_add(int segment, int start,
100 						 int end, u64 addr)
101 {
102 	struct pci_mmcfg_region *new;
103 
104 	new = pci_mmconfig_alloc(segment, start, end, addr);
105 	if (new) {
106 		mutex_lock(&pci_mmcfg_lock);
107 		list_add_sorted(new);
108 		mutex_unlock(&pci_mmcfg_lock);
109 
110 		pr_info(PREFIX
111 		       "MMCONFIG for domain %04x [bus %02x-%02x] at %pR "
112 		       "(base %#lx)\n",
113 		       segment, start, end, &new->res, (unsigned long)addr);
114 	}
115 
116 	return new;
117 }
118 
119 struct pci_mmcfg_region *pci_mmconfig_lookup(int segment, int bus)
120 {
121 	struct pci_mmcfg_region *cfg;
122 
123 	list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list, pci_mmcfg_lock_held())
124 		if (cfg->segment == segment &&
125 		    cfg->start_bus <= bus && bus <= cfg->end_bus)
126 			return cfg;
127 
128 	return NULL;
129 }
130 
131 static const char *__init pci_mmcfg_e7520(void)
132 {
133 	u32 win;
134 	raw_pci_ops->read(0, 0, PCI_DEVFN(0, 0), 0xce, 2, &win);
135 
136 	win = win & 0xf000;
137 	if (win == 0x0000 || win == 0xf000)
138 		return NULL;
139 
140 	if (pci_mmconfig_add(0, 0, 255, win << 16) == NULL)
141 		return NULL;
142 
143 	return "Intel Corporation E7520 Memory Controller Hub";
144 }
145 
146 static const char *__init pci_mmcfg_intel_945(void)
147 {
148 	u32 pciexbar, mask = 0, len = 0;
149 
150 	raw_pci_ops->read(0, 0, PCI_DEVFN(0, 0), 0x48, 4, &pciexbar);
151 
152 	/* Enable bit */
153 	if (!(pciexbar & 1))
154 		return NULL;
155 
156 	/* Size bits */
157 	switch ((pciexbar >> 1) & 3) {
158 	case 0:
159 		mask = 0xf0000000U;
160 		len  = 0x10000000U;
161 		break;
162 	case 1:
163 		mask = 0xf8000000U;
164 		len  = 0x08000000U;
165 		break;
166 	case 2:
167 		mask = 0xfc000000U;
168 		len  = 0x04000000U;
169 		break;
170 	default:
171 		return NULL;
172 	}
173 
174 	/* Errata #2, things break when not aligned on a 256Mb boundary */
175 	/* Can only happen in 64M/128M mode */
176 
177 	if ((pciexbar & mask) & 0x0fffffffU)
178 		return NULL;
179 
180 	/* Don't hit the APIC registers and their friends */
181 	if ((pciexbar & mask) >= 0xf0000000U)
182 		return NULL;
183 
184 	if (pci_mmconfig_add(0, 0, (len >> 20) - 1, pciexbar & mask) == NULL)
185 		return NULL;
186 
187 	return "Intel Corporation 945G/GZ/P/PL Express Memory Controller Hub";
188 }
189 
190 static const char *__init pci_mmcfg_amd_fam10h(void)
191 {
192 	u32 low, high, address;
193 	u64 base, msr;
194 	int i;
195 	unsigned segnbits = 0, busnbits, end_bus;
196 
197 	if (!(pci_probe & PCI_CHECK_ENABLE_AMD_MMCONF))
198 		return NULL;
199 
200 	address = MSR_FAM10H_MMIO_CONF_BASE;
201 	if (rdmsr_safe(address, &low, &high))
202 		return NULL;
203 
204 	msr = high;
205 	msr <<= 32;
206 	msr |= low;
207 
208 	/* mmconfig is not enable */
209 	if (!(msr & FAM10H_MMIO_CONF_ENABLE))
210 		return NULL;
211 
212 	base = msr & (FAM10H_MMIO_CONF_BASE_MASK<<FAM10H_MMIO_CONF_BASE_SHIFT);
213 
214 	busnbits = (msr >> FAM10H_MMIO_CONF_BUSRANGE_SHIFT) &
215 			 FAM10H_MMIO_CONF_BUSRANGE_MASK;
216 
217 	/*
218 	 * only handle bus 0 ?
219 	 * need to skip it
220 	 */
221 	if (!busnbits)
222 		return NULL;
223 
224 	if (busnbits > 8) {
225 		segnbits = busnbits - 8;
226 		busnbits = 8;
227 	}
228 
229 	end_bus = (1 << busnbits) - 1;
230 	for (i = 0; i < (1 << segnbits); i++)
231 		if (pci_mmconfig_add(i, 0, end_bus,
232 				     base + (1<<28) * i) == NULL) {
233 			free_all_mmcfg();
234 			return NULL;
235 		}
236 
237 	return "AMD Family 10h NB";
238 }
239 
240 static bool __initdata mcp55_checked;
241 static const char *__init pci_mmcfg_nvidia_mcp55(void)
242 {
243 	int bus;
244 	int mcp55_mmconf_found = 0;
245 
246 	static const u32 extcfg_regnum __initconst	= 0x90;
247 	static const u32 extcfg_regsize __initconst	= 4;
248 	static const u32 extcfg_enable_mask __initconst	= 1 << 31;
249 	static const u32 extcfg_start_mask __initconst	= 0xff << 16;
250 	static const int extcfg_start_shift __initconst	= 16;
251 	static const u32 extcfg_size_mask __initconst	= 0x3 << 28;
252 	static const int extcfg_size_shift __initconst	= 28;
253 	static const int extcfg_sizebus[] __initconst	= {
254 		0x100, 0x80, 0x40, 0x20
255 	};
256 	static const u32 extcfg_base_mask[] __initconst	= {
257 		0x7ff8, 0x7ffc, 0x7ffe, 0x7fff
258 	};
259 	static const int extcfg_base_lshift __initconst	= 25;
260 
261 	/*
262 	 * do check if amd fam10h already took over
263 	 */
264 	if (!acpi_disabled || !list_empty(&pci_mmcfg_list) || mcp55_checked)
265 		return NULL;
266 
267 	mcp55_checked = true;
268 	for (bus = 0; bus < 256; bus++) {
269 		u64 base;
270 		u32 l, extcfg;
271 		u16 vendor, device;
272 		int start, size_index, end;
273 
274 		raw_pci_ops->read(0, bus, PCI_DEVFN(0, 0), 0, 4, &l);
275 		vendor = l & 0xffff;
276 		device = (l >> 16) & 0xffff;
277 
278 		if (PCI_VENDOR_ID_NVIDIA != vendor || 0x0369 != device)
279 			continue;
280 
281 		raw_pci_ops->read(0, bus, PCI_DEVFN(0, 0), extcfg_regnum,
282 				  extcfg_regsize, &extcfg);
283 
284 		if (!(extcfg & extcfg_enable_mask))
285 			continue;
286 
287 		size_index = (extcfg & extcfg_size_mask) >> extcfg_size_shift;
288 		base = extcfg & extcfg_base_mask[size_index];
289 		/* base could > 4G */
290 		base <<= extcfg_base_lshift;
291 		start = (extcfg & extcfg_start_mask) >> extcfg_start_shift;
292 		end = start + extcfg_sizebus[size_index] - 1;
293 		if (pci_mmconfig_add(0, start, end, base) == NULL)
294 			continue;
295 		mcp55_mmconf_found++;
296 	}
297 
298 	if (!mcp55_mmconf_found)
299 		return NULL;
300 
301 	return "nVidia MCP55";
302 }
303 
304 struct pci_mmcfg_hostbridge_probe {
305 	u32 bus;
306 	u32 devfn;
307 	u32 vendor;
308 	u32 device;
309 	const char *(*probe)(void);
310 };
311 
312 static const struct pci_mmcfg_hostbridge_probe pci_mmcfg_probes[] __initconst = {
313 	{ 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_INTEL,
314 	  PCI_DEVICE_ID_INTEL_E7520_MCH, pci_mmcfg_e7520 },
315 	{ 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_INTEL,
316 	  PCI_DEVICE_ID_INTEL_82945G_HB, pci_mmcfg_intel_945 },
317 	{ 0, PCI_DEVFN(0x18, 0), PCI_VENDOR_ID_AMD,
318 	  0x1200, pci_mmcfg_amd_fam10h },
319 	{ 0xff, PCI_DEVFN(0, 0), PCI_VENDOR_ID_AMD,
320 	  0x1200, pci_mmcfg_amd_fam10h },
321 	{ 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_NVIDIA,
322 	  0x0369, pci_mmcfg_nvidia_mcp55 },
323 };
324 
325 static void __init pci_mmcfg_check_end_bus_number(void)
326 {
327 	struct pci_mmcfg_region *cfg, *cfgx;
328 
329 	/* Fixup overlaps */
330 	list_for_each_entry(cfg, &pci_mmcfg_list, list) {
331 		if (cfg->end_bus < cfg->start_bus)
332 			cfg->end_bus = 255;
333 
334 		/* Don't access the list head ! */
335 		if (cfg->list.next == &pci_mmcfg_list)
336 			break;
337 
338 		cfgx = list_entry(cfg->list.next, typeof(*cfg), list);
339 		if (cfg->end_bus >= cfgx->start_bus)
340 			cfg->end_bus = cfgx->start_bus - 1;
341 	}
342 }
343 
344 static int __init pci_mmcfg_check_hostbridge(void)
345 {
346 	u32 l;
347 	u32 bus, devfn;
348 	u16 vendor, device;
349 	int i;
350 	const char *name;
351 
352 	if (!raw_pci_ops)
353 		return 0;
354 
355 	free_all_mmcfg();
356 
357 	for (i = 0; i < ARRAY_SIZE(pci_mmcfg_probes); i++) {
358 		bus =  pci_mmcfg_probes[i].bus;
359 		devfn = pci_mmcfg_probes[i].devfn;
360 		raw_pci_ops->read(0, bus, devfn, 0, 4, &l);
361 		vendor = l & 0xffff;
362 		device = (l >> 16) & 0xffff;
363 
364 		name = NULL;
365 		if (pci_mmcfg_probes[i].vendor == vendor &&
366 		    pci_mmcfg_probes[i].device == device)
367 			name = pci_mmcfg_probes[i].probe();
368 
369 		if (name)
370 			pr_info(PREFIX "%s with MMCONFIG support\n", name);
371 	}
372 
373 	/* some end_bus_number is crazy, fix it */
374 	pci_mmcfg_check_end_bus_number();
375 
376 	return !list_empty(&pci_mmcfg_list);
377 }
378 
379 static acpi_status check_mcfg_resource(struct acpi_resource *res, void *data)
380 {
381 	struct resource *mcfg_res = data;
382 	struct acpi_resource_address64 address;
383 	acpi_status status;
384 
385 	if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
386 		struct acpi_resource_fixed_memory32 *fixmem32 =
387 			&res->data.fixed_memory32;
388 		if (!fixmem32)
389 			return AE_OK;
390 		if ((mcfg_res->start >= fixmem32->address) &&
391 		    (mcfg_res->end < (fixmem32->address +
392 				      fixmem32->address_length))) {
393 			mcfg_res->flags = 1;
394 			return AE_CTRL_TERMINATE;
395 		}
396 	}
397 	if ((res->type != ACPI_RESOURCE_TYPE_ADDRESS32) &&
398 	    (res->type != ACPI_RESOURCE_TYPE_ADDRESS64))
399 		return AE_OK;
400 
401 	status = acpi_resource_to_address64(res, &address);
402 	if (ACPI_FAILURE(status) ||
403 	   (address.address.address_length <= 0) ||
404 	   (address.resource_type != ACPI_MEMORY_RANGE))
405 		return AE_OK;
406 
407 	if ((mcfg_res->start >= address.address.minimum) &&
408 	    (mcfg_res->end < (address.address.minimum + address.address.address_length))) {
409 		mcfg_res->flags = 1;
410 		return AE_CTRL_TERMINATE;
411 	}
412 	return AE_OK;
413 }
414 
415 static acpi_status find_mboard_resource(acpi_handle handle, u32 lvl,
416 					void *context, void **rv)
417 {
418 	struct resource *mcfg_res = context;
419 
420 	acpi_walk_resources(handle, METHOD_NAME__CRS,
421 			    check_mcfg_resource, context);
422 
423 	if (mcfg_res->flags)
424 		return AE_CTRL_TERMINATE;
425 
426 	return AE_OK;
427 }
428 
429 static bool is_acpi_reserved(u64 start, u64 end, enum e820_type not_used)
430 {
431 	struct resource mcfg_res;
432 
433 	mcfg_res.start = start;
434 	mcfg_res.end = end - 1;
435 	mcfg_res.flags = 0;
436 
437 	acpi_get_devices("PNP0C01", find_mboard_resource, &mcfg_res, NULL);
438 
439 	if (!mcfg_res.flags)
440 		acpi_get_devices("PNP0C02", find_mboard_resource, &mcfg_res,
441 				 NULL);
442 
443 	return mcfg_res.flags;
444 }
445 
446 static bool is_efi_mmio(u64 start, u64 end, enum e820_type not_used)
447 {
448 #ifdef CONFIG_EFI
449 	efi_memory_desc_t *md;
450 	u64 size, mmio_start, mmio_end;
451 
452 	for_each_efi_memory_desc(md) {
453 		if (md->type == EFI_MEMORY_MAPPED_IO) {
454 			size = md->num_pages << EFI_PAGE_SHIFT;
455 			mmio_start = md->phys_addr;
456 			mmio_end = mmio_start + size;
457 
458 			/*
459 			 * N.B. Caller supplies (start, start + size),
460 			 * so to match, mmio_end is the first address
461 			 * *past* the EFI_MEMORY_MAPPED_IO area.
462 			 */
463 			if (mmio_start <= start && end <= mmio_end)
464 				return true;
465 		}
466 	}
467 #endif
468 
469 	return false;
470 }
471 
472 typedef bool (*check_reserved_t)(u64 start, u64 end, enum e820_type type);
473 
474 static bool __ref is_mmconf_reserved(check_reserved_t is_reserved,
475 				     struct pci_mmcfg_region *cfg,
476 				     struct device *dev, const char *method)
477 {
478 	u64 addr = cfg->res.start;
479 	u64 size = resource_size(&cfg->res);
480 	u64 old_size = size;
481 	int num_buses;
482 
483 	while (!is_reserved(addr, addr + size, E820_TYPE_RESERVED)) {
484 		size >>= 1;
485 		if (size < (16UL<<20))
486 			break;
487 	}
488 
489 	if (size < (16UL<<20) && size != old_size)
490 		return false;
491 
492 	if (dev)
493 		dev_info(dev, "MMCONFIG at %pR reserved as %s\n",
494 			 &cfg->res, method);
495 	else
496 		pr_info(PREFIX "MMCONFIG at %pR reserved as %s\n",
497 		       &cfg->res, method);
498 
499 	if (old_size != size) {
500 		/* update end_bus */
501 		cfg->end_bus = cfg->start_bus + ((size>>20) - 1);
502 		num_buses = cfg->end_bus - cfg->start_bus + 1;
503 		cfg->res.end = cfg->res.start +
504 		    PCI_MMCFG_BUS_OFFSET(num_buses) - 1;
505 		snprintf(cfg->name, PCI_MMCFG_RESOURCE_NAME_LEN,
506 			 "PCI MMCONFIG %04x [bus %02x-%02x]",
507 			 cfg->segment, cfg->start_bus, cfg->end_bus);
508 
509 		if (dev)
510 			dev_info(dev,
511 				"MMCONFIG "
512 				"at %pR (base %#lx) (size reduced!)\n",
513 				&cfg->res, (unsigned long) cfg->address);
514 		else
515 			pr_info(PREFIX
516 				"MMCONFIG for %04x [bus%02x-%02x] "
517 				"at %pR (base %#lx) (size reduced!)\n",
518 				cfg->segment, cfg->start_bus, cfg->end_bus,
519 				&cfg->res, (unsigned long) cfg->address);
520 	}
521 
522 	return true;
523 }
524 
525 static bool __ref
526 pci_mmcfg_check_reserved(struct device *dev, struct pci_mmcfg_region *cfg, int early)
527 {
528 	struct resource *conflict;
529 
530 	if (!early && !acpi_disabled) {
531 		if (is_mmconf_reserved(is_acpi_reserved, cfg, dev,
532 				       "ACPI motherboard resource"))
533 			return true;
534 
535 		if (dev)
536 			dev_info(dev, FW_INFO
537 				 "MMCONFIG at %pR not reserved in "
538 				 "ACPI motherboard resources\n",
539 				 &cfg->res);
540 		else
541 			pr_info(FW_INFO PREFIX
542 			       "MMCONFIG at %pR not reserved in "
543 			       "ACPI motherboard resources\n",
544 			       &cfg->res);
545 
546 		if (is_mmconf_reserved(is_efi_mmio, cfg, dev,
547 				       "EfiMemoryMappedIO")) {
548 			conflict = insert_resource_conflict(&iomem_resource,
549 							    &cfg->res);
550 			if (conflict)
551 				pr_warn("MMCONFIG %pR conflicts with %s %pR\n",
552 					&cfg->res, conflict->name, conflict);
553 			else
554 				pr_info("MMCONFIG %pR reserved to work around lack of ACPI motherboard _CRS\n",
555 					&cfg->res);
556 			return true;
557 		}
558 	}
559 
560 	/*
561 	 * e820__mapped_all() is marked as __init.
562 	 * All entries from ACPI MCFG table have been checked at boot time.
563 	 * For MCFG information constructed from hotpluggable host bridge's
564 	 * _CBA method, just assume it's reserved.
565 	 */
566 	if (pci_mmcfg_running_state)
567 		return true;
568 
569 	/* Don't try to do this check unless configuration
570 	   type 1 is available. how about type 2 ?*/
571 	if (raw_pci_ops)
572 		return is_mmconf_reserved(e820__mapped_all, cfg, dev,
573 					  "E820 entry");
574 
575 	return false;
576 }
577 
578 static void __init pci_mmcfg_reject_broken(int early)
579 {
580 	struct pci_mmcfg_region *cfg;
581 
582 	list_for_each_entry(cfg, &pci_mmcfg_list, list) {
583 		if (pci_mmcfg_check_reserved(NULL, cfg, early) == 0) {
584 			pr_info(PREFIX "not using MMCONFIG\n");
585 			free_all_mmcfg();
586 			return;
587 		}
588 	}
589 }
590 
591 static int __init acpi_mcfg_check_entry(struct acpi_table_mcfg *mcfg,
592 					struct acpi_mcfg_allocation *cfg)
593 {
594 	if (cfg->address < 0xFFFFFFFF)
595 		return 0;
596 
597 	if (!strncmp(mcfg->header.oem_id, "SGI", 3))
598 		return 0;
599 
600 	if ((mcfg->header.revision >= 1) && (dmi_get_bios_year() >= 2010))
601 		return 0;
602 
603 	pr_err(PREFIX "MCFG region for %04x [bus %02x-%02x] at %#llx "
604 	       "is above 4GB, ignored\n", cfg->pci_segment,
605 	       cfg->start_bus_number, cfg->end_bus_number, cfg->address);
606 	return -EINVAL;
607 }
608 
609 static int __init pci_parse_mcfg(struct acpi_table_header *header)
610 {
611 	struct acpi_table_mcfg *mcfg;
612 	struct acpi_mcfg_allocation *cfg_table, *cfg;
613 	unsigned long i;
614 	int entries;
615 
616 	if (!header)
617 		return -EINVAL;
618 
619 	mcfg = (struct acpi_table_mcfg *)header;
620 
621 	/* how many config structures do we have */
622 	free_all_mmcfg();
623 	entries = 0;
624 	i = header->length - sizeof(struct acpi_table_mcfg);
625 	while (i >= sizeof(struct acpi_mcfg_allocation)) {
626 		entries++;
627 		i -= sizeof(struct acpi_mcfg_allocation);
628 	}
629 	if (entries == 0) {
630 		pr_err(PREFIX "MMCONFIG has no entries\n");
631 		return -ENODEV;
632 	}
633 
634 	cfg_table = (struct acpi_mcfg_allocation *) &mcfg[1];
635 	for (i = 0; i < entries; i++) {
636 		cfg = &cfg_table[i];
637 		if (acpi_mcfg_check_entry(mcfg, cfg)) {
638 			free_all_mmcfg();
639 			return -ENODEV;
640 		}
641 
642 		if (pci_mmconfig_add(cfg->pci_segment, cfg->start_bus_number,
643 				   cfg->end_bus_number, cfg->address) == NULL) {
644 			pr_warn(PREFIX "no memory for MCFG entries\n");
645 			free_all_mmcfg();
646 			return -ENOMEM;
647 		}
648 	}
649 
650 	return 0;
651 }
652 
653 #ifdef CONFIG_ACPI_APEI
654 extern int (*arch_apei_filter_addr)(int (*func)(__u64 start, __u64 size,
655 				     void *data), void *data);
656 
657 static int pci_mmcfg_for_each_region(int (*func)(__u64 start, __u64 size,
658 				     void *data), void *data)
659 {
660 	struct pci_mmcfg_region *cfg;
661 	int rc;
662 
663 	if (list_empty(&pci_mmcfg_list))
664 		return 0;
665 
666 	list_for_each_entry(cfg, &pci_mmcfg_list, list) {
667 		rc = func(cfg->res.start, resource_size(&cfg->res), data);
668 		if (rc)
669 			return rc;
670 	}
671 
672 	return 0;
673 }
674 #define set_apei_filter() (arch_apei_filter_addr = pci_mmcfg_for_each_region)
675 #else
676 #define set_apei_filter()
677 #endif
678 
679 static void __init __pci_mmcfg_init(int early)
680 {
681 	pci_mmcfg_reject_broken(early);
682 	if (list_empty(&pci_mmcfg_list))
683 		return;
684 
685 	if (pcibios_last_bus < 0) {
686 		const struct pci_mmcfg_region *cfg;
687 
688 		list_for_each_entry(cfg, &pci_mmcfg_list, list) {
689 			if (cfg->segment)
690 				break;
691 			pcibios_last_bus = cfg->end_bus;
692 		}
693 	}
694 
695 	if (pci_mmcfg_arch_init())
696 		pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
697 	else {
698 		free_all_mmcfg();
699 		pci_mmcfg_arch_init_failed = true;
700 	}
701 }
702 
703 static int __initdata known_bridge;
704 
705 void __init pci_mmcfg_early_init(void)
706 {
707 	if (pci_probe & PCI_PROBE_MMCONF) {
708 		if (pci_mmcfg_check_hostbridge())
709 			known_bridge = 1;
710 		else
711 			acpi_table_parse(ACPI_SIG_MCFG, pci_parse_mcfg);
712 		__pci_mmcfg_init(1);
713 
714 		set_apei_filter();
715 	}
716 }
717 
718 void __init pci_mmcfg_late_init(void)
719 {
720 	/* MMCONFIG disabled */
721 	if ((pci_probe & PCI_PROBE_MMCONF) == 0)
722 		return;
723 
724 	if (known_bridge)
725 		return;
726 
727 	/* MMCONFIG hasn't been enabled yet, try again */
728 	if (pci_probe & PCI_PROBE_MASK & ~PCI_PROBE_MMCONF) {
729 		acpi_table_parse(ACPI_SIG_MCFG, pci_parse_mcfg);
730 		__pci_mmcfg_init(0);
731 	}
732 }
733 
734 static int __init pci_mmcfg_late_insert_resources(void)
735 {
736 	struct pci_mmcfg_region *cfg;
737 
738 	pci_mmcfg_running_state = true;
739 
740 	/* If we are not using MMCONFIG, don't insert the resources. */
741 	if ((pci_probe & PCI_PROBE_MMCONF) == 0)
742 		return 1;
743 
744 	/*
745 	 * Attempt to insert the mmcfg resources but not with the busy flag
746 	 * marked so it won't cause request errors when __request_region is
747 	 * called.
748 	 */
749 	list_for_each_entry(cfg, &pci_mmcfg_list, list)
750 		if (!cfg->res.parent)
751 			insert_resource(&iomem_resource, &cfg->res);
752 
753 	return 0;
754 }
755 
756 /*
757  * Perform MMCONFIG resource insertion after PCI initialization to allow for
758  * misprogrammed MCFG tables that state larger sizes but actually conflict
759  * with other system resources.
760  */
761 late_initcall(pci_mmcfg_late_insert_resources);
762 
763 /* Add MMCFG information for host bridges */
764 int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
765 			phys_addr_t addr)
766 {
767 	int rc;
768 	struct resource *tmp = NULL;
769 	struct pci_mmcfg_region *cfg;
770 
771 	if (!(pci_probe & PCI_PROBE_MMCONF) || pci_mmcfg_arch_init_failed)
772 		return -ENODEV;
773 
774 	if (start > end)
775 		return -EINVAL;
776 
777 	mutex_lock(&pci_mmcfg_lock);
778 	cfg = pci_mmconfig_lookup(seg, start);
779 	if (cfg) {
780 		if (cfg->end_bus < end)
781 			dev_info(dev, FW_INFO
782 				 "MMCONFIG for "
783 				 "domain %04x [bus %02x-%02x] "
784 				 "only partially covers this bridge\n",
785 				  cfg->segment, cfg->start_bus, cfg->end_bus);
786 		mutex_unlock(&pci_mmcfg_lock);
787 		return -EEXIST;
788 	}
789 
790 	if (!addr) {
791 		mutex_unlock(&pci_mmcfg_lock);
792 		return -EINVAL;
793 	}
794 
795 	rc = -EBUSY;
796 	cfg = pci_mmconfig_alloc(seg, start, end, addr);
797 	if (cfg == NULL) {
798 		dev_warn(dev, "fail to add MMCONFIG (out of memory)\n");
799 		rc = -ENOMEM;
800 	} else if (!pci_mmcfg_check_reserved(dev, cfg, 0)) {
801 		dev_warn(dev, FW_BUG "MMCONFIG %pR isn't reserved\n",
802 			 &cfg->res);
803 	} else {
804 		/* Insert resource if it's not in boot stage */
805 		if (pci_mmcfg_running_state)
806 			tmp = insert_resource_conflict(&iomem_resource,
807 						       &cfg->res);
808 
809 		if (tmp) {
810 			dev_warn(dev,
811 				 "MMCONFIG %pR conflicts with "
812 				 "%s %pR\n",
813 				 &cfg->res, tmp->name, tmp);
814 		} else if (pci_mmcfg_arch_map(cfg)) {
815 			dev_warn(dev, "fail to map MMCONFIG %pR.\n",
816 				 &cfg->res);
817 		} else {
818 			list_add_sorted(cfg);
819 			dev_info(dev, "MMCONFIG at %pR (base %#lx)\n",
820 				 &cfg->res, (unsigned long)addr);
821 			cfg = NULL;
822 			rc = 0;
823 		}
824 	}
825 
826 	if (cfg) {
827 		if (cfg->res.parent)
828 			release_resource(&cfg->res);
829 		kfree(cfg);
830 	}
831 
832 	mutex_unlock(&pci_mmcfg_lock);
833 
834 	return rc;
835 }
836 
837 /* Delete MMCFG information for host bridges */
838 int pci_mmconfig_delete(u16 seg, u8 start, u8 end)
839 {
840 	struct pci_mmcfg_region *cfg;
841 
842 	mutex_lock(&pci_mmcfg_lock);
843 	list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list)
844 		if (cfg->segment == seg && cfg->start_bus == start &&
845 		    cfg->end_bus == end) {
846 			list_del_rcu(&cfg->list);
847 			synchronize_rcu();
848 			pci_mmcfg_arch_unmap(cfg);
849 			if (cfg->res.parent)
850 				release_resource(&cfg->res);
851 			mutex_unlock(&pci_mmcfg_lock);
852 			kfree(cfg);
853 			return 0;
854 		}
855 	mutex_unlock(&pci_mmcfg_lock);
856 
857 	return -ENOENT;
858 }
859