xref: /openbmc/linux/arch/x86/pci/mmconfig-shared.c (revision 5d331b7f)
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/pci.h>
15 #include <linux/init.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/api.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 void __init 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 void __init 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 struct pci_mmcfg_region *__init 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 __initconst	= 0x90;
245 	static const u32 extcfg_regsize __initconst	= 4;
246 	static const u32 extcfg_enable_mask __initconst	= 1 << 31;
247 	static const u32 extcfg_start_mask __initconst	= 0xff << 16;
248 	static const int extcfg_start_shift __initconst	= 16;
249 	static const u32 extcfg_size_mask __initconst	= 0x3 << 28;
250 	static const int extcfg_size_shift __initconst	= 28;
251 	static const int extcfg_sizebus[] __initconst	= {
252 		0x100, 0x80, 0x40, 0x20
253 	};
254 	static const u32 extcfg_base_mask[] __initconst	= {
255 		0x7ff8, 0x7ffc, 0x7ffe, 0x7fff
256 	};
257 	static const int extcfg_base_lshift __initconst	= 25;
258 
259 	/*
260 	 * do check if amd fam10h already took over
261 	 */
262 	if (!acpi_disabled || !list_empty(&pci_mmcfg_list) || mcp55_checked)
263 		return NULL;
264 
265 	mcp55_checked = true;
266 	for (bus = 0; bus < 256; bus++) {
267 		u64 base;
268 		u32 l, extcfg;
269 		u16 vendor, device;
270 		int start, size_index, end;
271 
272 		raw_pci_ops->read(0, bus, PCI_DEVFN(0, 0), 0, 4, &l);
273 		vendor = l & 0xffff;
274 		device = (l >> 16) & 0xffff;
275 
276 		if (PCI_VENDOR_ID_NVIDIA != vendor || 0x0369 != device)
277 			continue;
278 
279 		raw_pci_ops->read(0, bus, PCI_DEVFN(0, 0), extcfg_regnum,
280 				  extcfg_regsize, &extcfg);
281 
282 		if (!(extcfg & extcfg_enable_mask))
283 			continue;
284 
285 		size_index = (extcfg & extcfg_size_mask) >> extcfg_size_shift;
286 		base = extcfg & extcfg_base_mask[size_index];
287 		/* base could > 4G */
288 		base <<= extcfg_base_lshift;
289 		start = (extcfg & extcfg_start_mask) >> extcfg_start_shift;
290 		end = start + extcfg_sizebus[size_index] - 1;
291 		if (pci_mmconfig_add(0, start, end, base) == NULL)
292 			continue;
293 		mcp55_mmconf_found++;
294 	}
295 
296 	if (!mcp55_mmconf_found)
297 		return NULL;
298 
299 	return "nVidia MCP55";
300 }
301 
302 struct pci_mmcfg_hostbridge_probe {
303 	u32 bus;
304 	u32 devfn;
305 	u32 vendor;
306 	u32 device;
307 	const char *(*probe)(void);
308 };
309 
310 static const struct pci_mmcfg_hostbridge_probe pci_mmcfg_probes[] __initconst = {
311 	{ 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_INTEL,
312 	  PCI_DEVICE_ID_INTEL_E7520_MCH, pci_mmcfg_e7520 },
313 	{ 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_INTEL,
314 	  PCI_DEVICE_ID_INTEL_82945G_HB, pci_mmcfg_intel_945 },
315 	{ 0, PCI_DEVFN(0x18, 0), PCI_VENDOR_ID_AMD,
316 	  0x1200, pci_mmcfg_amd_fam10h },
317 	{ 0xff, PCI_DEVFN(0, 0), PCI_VENDOR_ID_AMD,
318 	  0x1200, pci_mmcfg_amd_fam10h },
319 	{ 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_NVIDIA,
320 	  0x0369, pci_mmcfg_nvidia_mcp55 },
321 };
322 
323 static void __init pci_mmcfg_check_end_bus_number(void)
324 {
325 	struct pci_mmcfg_region *cfg, *cfgx;
326 
327 	/* Fixup overlaps */
328 	list_for_each_entry(cfg, &pci_mmcfg_list, list) {
329 		if (cfg->end_bus < cfg->start_bus)
330 			cfg->end_bus = 255;
331 
332 		/* Don't access the list head ! */
333 		if (cfg->list.next == &pci_mmcfg_list)
334 			break;
335 
336 		cfgx = list_entry(cfg->list.next, typeof(*cfg), list);
337 		if (cfg->end_bus >= cfgx->start_bus)
338 			cfg->end_bus = cfgx->start_bus - 1;
339 	}
340 }
341 
342 static int __init pci_mmcfg_check_hostbridge(void)
343 {
344 	u32 l;
345 	u32 bus, devfn;
346 	u16 vendor, device;
347 	int i;
348 	const char *name;
349 
350 	if (!raw_pci_ops)
351 		return 0;
352 
353 	free_all_mmcfg();
354 
355 	for (i = 0; i < ARRAY_SIZE(pci_mmcfg_probes); i++) {
356 		bus =  pci_mmcfg_probes[i].bus;
357 		devfn = pci_mmcfg_probes[i].devfn;
358 		raw_pci_ops->read(0, bus, devfn, 0, 4, &l);
359 		vendor = l & 0xffff;
360 		device = (l >> 16) & 0xffff;
361 
362 		name = NULL;
363 		if (pci_mmcfg_probes[i].vendor == vendor &&
364 		    pci_mmcfg_probes[i].device == device)
365 			name = pci_mmcfg_probes[i].probe();
366 
367 		if (name)
368 			pr_info(PREFIX "%s with MMCONFIG support\n", name);
369 	}
370 
371 	/* some end_bus_number is crazy, fix it */
372 	pci_mmcfg_check_end_bus_number();
373 
374 	return !list_empty(&pci_mmcfg_list);
375 }
376 
377 static acpi_status check_mcfg_resource(struct acpi_resource *res, void *data)
378 {
379 	struct resource *mcfg_res = data;
380 	struct acpi_resource_address64 address;
381 	acpi_status status;
382 
383 	if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
384 		struct acpi_resource_fixed_memory32 *fixmem32 =
385 			&res->data.fixed_memory32;
386 		if (!fixmem32)
387 			return AE_OK;
388 		if ((mcfg_res->start >= fixmem32->address) &&
389 		    (mcfg_res->end < (fixmem32->address +
390 				      fixmem32->address_length))) {
391 			mcfg_res->flags = 1;
392 			return AE_CTRL_TERMINATE;
393 		}
394 	}
395 	if ((res->type != ACPI_RESOURCE_TYPE_ADDRESS32) &&
396 	    (res->type != ACPI_RESOURCE_TYPE_ADDRESS64))
397 		return AE_OK;
398 
399 	status = acpi_resource_to_address64(res, &address);
400 	if (ACPI_FAILURE(status) ||
401 	   (address.address.address_length <= 0) ||
402 	   (address.resource_type != ACPI_MEMORY_RANGE))
403 		return AE_OK;
404 
405 	if ((mcfg_res->start >= address.address.minimum) &&
406 	    (mcfg_res->end < (address.address.minimum + address.address.address_length))) {
407 		mcfg_res->flags = 1;
408 		return AE_CTRL_TERMINATE;
409 	}
410 	return AE_OK;
411 }
412 
413 static acpi_status find_mboard_resource(acpi_handle handle, u32 lvl,
414 					void *context, void **rv)
415 {
416 	struct resource *mcfg_res = context;
417 
418 	acpi_walk_resources(handle, METHOD_NAME__CRS,
419 			    check_mcfg_resource, context);
420 
421 	if (mcfg_res->flags)
422 		return AE_CTRL_TERMINATE;
423 
424 	return AE_OK;
425 }
426 
427 static bool is_acpi_reserved(u64 start, u64 end, unsigned not_used)
428 {
429 	struct resource mcfg_res;
430 
431 	mcfg_res.start = start;
432 	mcfg_res.end = end - 1;
433 	mcfg_res.flags = 0;
434 
435 	acpi_get_devices("PNP0C01", find_mboard_resource, &mcfg_res, NULL);
436 
437 	if (!mcfg_res.flags)
438 		acpi_get_devices("PNP0C02", find_mboard_resource, &mcfg_res,
439 				 NULL);
440 
441 	return mcfg_res.flags;
442 }
443 
444 typedef bool (*check_reserved_t)(u64 start, u64 end, unsigned type);
445 
446 static bool __ref is_mmconf_reserved(check_reserved_t is_reserved,
447 				     struct pci_mmcfg_region *cfg,
448 				     struct device *dev, int with_e820)
449 {
450 	u64 addr = cfg->res.start;
451 	u64 size = resource_size(&cfg->res);
452 	u64 old_size = size;
453 	int num_buses;
454 	char *method = with_e820 ? "E820" : "ACPI motherboard resources";
455 
456 	while (!is_reserved(addr, addr + size, E820_TYPE_RESERVED)) {
457 		size >>= 1;
458 		if (size < (16UL<<20))
459 			break;
460 	}
461 
462 	if (size < (16UL<<20) && size != old_size)
463 		return 0;
464 
465 	if (dev)
466 		dev_info(dev, "MMCONFIG at %pR reserved in %s\n",
467 			 &cfg->res, method);
468 	else
469 		pr_info(PREFIX "MMCONFIG at %pR reserved in %s\n",
470 		       &cfg->res, method);
471 
472 	if (old_size != size) {
473 		/* update end_bus */
474 		cfg->end_bus = cfg->start_bus + ((size>>20) - 1);
475 		num_buses = cfg->end_bus - cfg->start_bus + 1;
476 		cfg->res.end = cfg->res.start +
477 		    PCI_MMCFG_BUS_OFFSET(num_buses) - 1;
478 		snprintf(cfg->name, PCI_MMCFG_RESOURCE_NAME_LEN,
479 			 "PCI MMCONFIG %04x [bus %02x-%02x]",
480 			 cfg->segment, cfg->start_bus, cfg->end_bus);
481 
482 		if (dev)
483 			dev_info(dev,
484 				"MMCONFIG "
485 				"at %pR (base %#lx) (size reduced!)\n",
486 				&cfg->res, (unsigned long) cfg->address);
487 		else
488 			pr_info(PREFIX
489 				"MMCONFIG for %04x [bus%02x-%02x] "
490 				"at %pR (base %#lx) (size reduced!)\n",
491 				cfg->segment, cfg->start_bus, cfg->end_bus,
492 				&cfg->res, (unsigned long) cfg->address);
493 	}
494 
495 	return 1;
496 }
497 
498 static bool __ref
499 pci_mmcfg_check_reserved(struct device *dev, struct pci_mmcfg_region *cfg, int early)
500 {
501 	if (!early && !acpi_disabled) {
502 		if (is_mmconf_reserved(is_acpi_reserved, cfg, dev, 0))
503 			return 1;
504 
505 		if (dev)
506 			dev_info(dev, FW_INFO
507 				 "MMCONFIG at %pR not reserved in "
508 				 "ACPI motherboard resources\n",
509 				 &cfg->res);
510 		else
511 			pr_info(FW_INFO PREFIX
512 			       "MMCONFIG at %pR not reserved in "
513 			       "ACPI motherboard resources\n",
514 			       &cfg->res);
515 	}
516 
517 	/*
518 	 * e820__mapped_all() is marked as __init.
519 	 * All entries from ACPI MCFG table have been checked at boot time.
520 	 * For MCFG information constructed from hotpluggable host bridge's
521 	 * _CBA method, just assume it's reserved.
522 	 */
523 	if (pci_mmcfg_running_state)
524 		return 1;
525 
526 	/* Don't try to do this check unless configuration
527 	   type 1 is available. how about type 2 ?*/
528 	if (raw_pci_ops)
529 		return is_mmconf_reserved(e820__mapped_all, cfg, dev, 1);
530 
531 	return 0;
532 }
533 
534 static void __init pci_mmcfg_reject_broken(int early)
535 {
536 	struct pci_mmcfg_region *cfg;
537 
538 	list_for_each_entry(cfg, &pci_mmcfg_list, list) {
539 		if (pci_mmcfg_check_reserved(NULL, cfg, early) == 0) {
540 			pr_info(PREFIX "not using MMCONFIG\n");
541 			free_all_mmcfg();
542 			return;
543 		}
544 	}
545 }
546 
547 static int __init acpi_mcfg_check_entry(struct acpi_table_mcfg *mcfg,
548 					struct acpi_mcfg_allocation *cfg)
549 {
550 	if (cfg->address < 0xFFFFFFFF)
551 		return 0;
552 
553 	if (!strncmp(mcfg->header.oem_id, "SGI", 3))
554 		return 0;
555 
556 	if ((mcfg->header.revision >= 1) && (dmi_get_bios_year() >= 2010))
557 		return 0;
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 
565 static 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 
609 #ifdef CONFIG_ACPI_APEI
610 extern int (*arch_apei_filter_addr)(int (*func)(__u64 start, __u64 size,
611 				     void *data), void *data);
612 
613 static int pci_mmcfg_for_each_region(int (*func)(__u64 start, __u64 size,
614 				     void *data), void *data)
615 {
616 	struct pci_mmcfg_region *cfg;
617 	int rc;
618 
619 	if (list_empty(&pci_mmcfg_list))
620 		return 0;
621 
622 	list_for_each_entry(cfg, &pci_mmcfg_list, list) {
623 		rc = func(cfg->res.start, resource_size(&cfg->res), data);
624 		if (rc)
625 			return rc;
626 	}
627 
628 	return 0;
629 }
630 #define set_apei_filter() (arch_apei_filter_addr = pci_mmcfg_for_each_region)
631 #else
632 #define set_apei_filter()
633 #endif
634 
635 static void __init __pci_mmcfg_init(int early)
636 {
637 	pci_mmcfg_reject_broken(early);
638 	if (list_empty(&pci_mmcfg_list))
639 		return;
640 
641 	if (pcibios_last_bus < 0) {
642 		const struct pci_mmcfg_region *cfg;
643 
644 		list_for_each_entry(cfg, &pci_mmcfg_list, list) {
645 			if (cfg->segment)
646 				break;
647 			pcibios_last_bus = cfg->end_bus;
648 		}
649 	}
650 
651 	if (pci_mmcfg_arch_init())
652 		pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
653 	else {
654 		free_all_mmcfg();
655 		pci_mmcfg_arch_init_failed = true;
656 	}
657 }
658 
659 static int __initdata known_bridge;
660 
661 void __init pci_mmcfg_early_init(void)
662 {
663 	if (pci_probe & PCI_PROBE_MMCONF) {
664 		if (pci_mmcfg_check_hostbridge())
665 			known_bridge = 1;
666 		else
667 			acpi_sfi_table_parse(ACPI_SIG_MCFG, pci_parse_mcfg);
668 		__pci_mmcfg_init(1);
669 
670 		set_apei_filter();
671 	}
672 }
673 
674 void __init pci_mmcfg_late_init(void)
675 {
676 	/* MMCONFIG disabled */
677 	if ((pci_probe & PCI_PROBE_MMCONF) == 0)
678 		return;
679 
680 	if (known_bridge)
681 		return;
682 
683 	/* MMCONFIG hasn't been enabled yet, try again */
684 	if (pci_probe & PCI_PROBE_MASK & ~PCI_PROBE_MMCONF) {
685 		acpi_sfi_table_parse(ACPI_SIG_MCFG, pci_parse_mcfg);
686 		__pci_mmcfg_init(0);
687 	}
688 }
689 
690 static int __init pci_mmcfg_late_insert_resources(void)
691 {
692 	struct pci_mmcfg_region *cfg;
693 
694 	pci_mmcfg_running_state = true;
695 
696 	/* If we are not using MMCONFIG, don't insert the resources. */
697 	if ((pci_probe & PCI_PROBE_MMCONF) == 0)
698 		return 1;
699 
700 	/*
701 	 * Attempt to insert the mmcfg resources but not with the busy flag
702 	 * marked so it won't cause request errors when __request_region is
703 	 * called.
704 	 */
705 	list_for_each_entry(cfg, &pci_mmcfg_list, list)
706 		if (!cfg->res.parent)
707 			insert_resource(&iomem_resource, &cfg->res);
708 
709 	return 0;
710 }
711 
712 /*
713  * Perform MMCONFIG resource insertion after PCI initialization to allow for
714  * misprogrammed MCFG tables that state larger sizes but actually conflict
715  * with other system resources.
716  */
717 late_initcall(pci_mmcfg_late_insert_resources);
718 
719 /* Add MMCFG information for host bridges */
720 int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
721 			phys_addr_t addr)
722 {
723 	int rc;
724 	struct resource *tmp = NULL;
725 	struct pci_mmcfg_region *cfg;
726 
727 	if (!(pci_probe & PCI_PROBE_MMCONF) || pci_mmcfg_arch_init_failed)
728 		return -ENODEV;
729 
730 	if (start > end)
731 		return -EINVAL;
732 
733 	mutex_lock(&pci_mmcfg_lock);
734 	cfg = pci_mmconfig_lookup(seg, start);
735 	if (cfg) {
736 		if (cfg->end_bus < end)
737 			dev_info(dev, FW_INFO
738 				 "MMCONFIG for "
739 				 "domain %04x [bus %02x-%02x] "
740 				 "only partially covers this bridge\n",
741 				  cfg->segment, cfg->start_bus, cfg->end_bus);
742 		mutex_unlock(&pci_mmcfg_lock);
743 		return -EEXIST;
744 	}
745 
746 	if (!addr) {
747 		mutex_unlock(&pci_mmcfg_lock);
748 		return -EINVAL;
749 	}
750 
751 	rc = -EBUSY;
752 	cfg = pci_mmconfig_alloc(seg, start, end, addr);
753 	if (cfg == NULL) {
754 		dev_warn(dev, "fail to add MMCONFIG (out of memory)\n");
755 		rc = -ENOMEM;
756 	} else if (!pci_mmcfg_check_reserved(dev, cfg, 0)) {
757 		dev_warn(dev, FW_BUG "MMCONFIG %pR isn't reserved\n",
758 			 &cfg->res);
759 	} else {
760 		/* Insert resource if it's not in boot stage */
761 		if (pci_mmcfg_running_state)
762 			tmp = insert_resource_conflict(&iomem_resource,
763 						       &cfg->res);
764 
765 		if (tmp) {
766 			dev_warn(dev,
767 				 "MMCONFIG %pR conflicts with "
768 				 "%s %pR\n",
769 				 &cfg->res, tmp->name, tmp);
770 		} else if (pci_mmcfg_arch_map(cfg)) {
771 			dev_warn(dev, "fail to map MMCONFIG %pR.\n",
772 				 &cfg->res);
773 		} else {
774 			list_add_sorted(cfg);
775 			dev_info(dev, "MMCONFIG at %pR (base %#lx)\n",
776 				 &cfg->res, (unsigned long)addr);
777 			cfg = NULL;
778 			rc = 0;
779 		}
780 	}
781 
782 	if (cfg) {
783 		if (cfg->res.parent)
784 			release_resource(&cfg->res);
785 		kfree(cfg);
786 	}
787 
788 	mutex_unlock(&pci_mmcfg_lock);
789 
790 	return rc;
791 }
792 
793 /* Delete MMCFG information for host bridges */
794 int pci_mmconfig_delete(u16 seg, u8 start, u8 end)
795 {
796 	struct pci_mmcfg_region *cfg;
797 
798 	mutex_lock(&pci_mmcfg_lock);
799 	list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list)
800 		if (cfg->segment == seg && cfg->start_bus == start &&
801 		    cfg->end_bus == end) {
802 			list_del_rcu(&cfg->list);
803 			synchronize_rcu();
804 			pci_mmcfg_arch_unmap(cfg);
805 			if (cfg->res.parent)
806 				release_resource(&cfg->res);
807 			mutex_unlock(&pci_mmcfg_lock);
808 			kfree(cfg);
809 			return 0;
810 		}
811 	mutex_unlock(&pci_mmcfg_lock);
812 
813 	return -ENOENT;
814 }
815