xref: /openbmc/linux/arch/x86/pci/mmconfig-shared.c (revision 9ac8d3fb) 
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/bitmap.h>
17 #include <asm/e820.h>
18 
19 #include "pci.h"
20 
21 /* aperture is up to 256MB but BIOS may reserve less */
22 #define MMCONFIG_APER_MIN	(2 * 1024*1024)
23 #define MMCONFIG_APER_MAX	(256 * 1024*1024)
24 
25 /* Indicate if the mmcfg resources have been placed into the resource table. */
26 static int __initdata pci_mmcfg_resources_inserted;
27 
28 static const char __init *pci_mmcfg_e7520(void)
29 {
30 	u32 win;
31 	raw_pci_ops->read(0, 0, PCI_DEVFN(0, 0), 0xce, 2, &win);
32 
33 	win = win & 0xf000;
34 	if(win == 0x0000 || win == 0xf000)
35 		pci_mmcfg_config_num = 0;
36 	else {
37 		pci_mmcfg_config_num = 1;
38 		pci_mmcfg_config = kzalloc(sizeof(pci_mmcfg_config[0]), GFP_KERNEL);
39 		if (!pci_mmcfg_config)
40 			return NULL;
41 		pci_mmcfg_config[0].address = win << 16;
42 		pci_mmcfg_config[0].pci_segment = 0;
43 		pci_mmcfg_config[0].start_bus_number = 0;
44 		pci_mmcfg_config[0].end_bus_number = 255;
45 	}
46 
47 	return "Intel Corporation E7520 Memory Controller Hub";
48 }
49 
50 static const char __init *pci_mmcfg_intel_945(void)
51 {
52 	u32 pciexbar, mask = 0, len = 0;
53 
54 	pci_mmcfg_config_num = 1;
55 
56 	raw_pci_ops->read(0, 0, PCI_DEVFN(0, 0), 0x48, 4, &pciexbar);
57 
58 	/* Enable bit */
59 	if (!(pciexbar & 1))
60 		pci_mmcfg_config_num = 0;
61 
62 	/* Size bits */
63 	switch ((pciexbar >> 1) & 3) {
64 	case 0:
65 		mask = 0xf0000000U;
66 		len  = 0x10000000U;
67 		break;
68 	case 1:
69 		mask = 0xf8000000U;
70 		len  = 0x08000000U;
71 		break;
72 	case 2:
73 		mask = 0xfc000000U;
74 		len  = 0x04000000U;
75 		break;
76 	default:
77 		pci_mmcfg_config_num = 0;
78 	}
79 
80 	/* Errata #2, things break when not aligned on a 256Mb boundary */
81 	/* Can only happen in 64M/128M mode */
82 
83 	if ((pciexbar & mask) & 0x0fffffffU)
84 		pci_mmcfg_config_num = 0;
85 
86 	/* Don't hit the APIC registers and their friends */
87 	if ((pciexbar & mask) >= 0xf0000000U)
88 		pci_mmcfg_config_num = 0;
89 
90 	if (pci_mmcfg_config_num) {
91 		pci_mmcfg_config = kzalloc(sizeof(pci_mmcfg_config[0]), GFP_KERNEL);
92 		if (!pci_mmcfg_config)
93 			return NULL;
94 		pci_mmcfg_config[0].address = pciexbar & mask;
95 		pci_mmcfg_config[0].pci_segment = 0;
96 		pci_mmcfg_config[0].start_bus_number = 0;
97 		pci_mmcfg_config[0].end_bus_number = (len >> 20) - 1;
98 	}
99 
100 	return "Intel Corporation 945G/GZ/P/PL Express Memory Controller Hub";
101 }
102 
103 static const char __init *pci_mmcfg_amd_fam10h(void)
104 {
105 	u32 low, high, address;
106 	u64 base, msr;
107 	int i;
108 	unsigned segnbits = 0, busnbits;
109 
110 	if (!(pci_probe & PCI_CHECK_ENABLE_AMD_MMCONF))
111 		return NULL;
112 
113 	address = MSR_FAM10H_MMIO_CONF_BASE;
114 	if (rdmsr_safe(address, &low, &high))
115 		return NULL;
116 
117 	msr = high;
118 	msr <<= 32;
119 	msr |= low;
120 
121 	/* mmconfig is not enable */
122 	if (!(msr & FAM10H_MMIO_CONF_ENABLE))
123 		return NULL;
124 
125 	base = msr & (FAM10H_MMIO_CONF_BASE_MASK<<FAM10H_MMIO_CONF_BASE_SHIFT);
126 
127 	busnbits = (msr >> FAM10H_MMIO_CONF_BUSRANGE_SHIFT) &
128 			 FAM10H_MMIO_CONF_BUSRANGE_MASK;
129 
130 	/*
131 	 * only handle bus 0 ?
132 	 * need to skip it
133 	 */
134 	if (!busnbits)
135 		return NULL;
136 
137 	if (busnbits > 8) {
138 		segnbits = busnbits - 8;
139 		busnbits = 8;
140 	}
141 
142 	pci_mmcfg_config_num = (1 << segnbits);
143 	pci_mmcfg_config = kzalloc(sizeof(pci_mmcfg_config[0]) *
144 				   pci_mmcfg_config_num, GFP_KERNEL);
145 	if (!pci_mmcfg_config)
146 		return NULL;
147 
148 	for (i = 0; i < (1 << segnbits); i++) {
149 		pci_mmcfg_config[i].address = base + (1<<28) * i;
150 		pci_mmcfg_config[i].pci_segment = i;
151 		pci_mmcfg_config[i].start_bus_number = 0;
152 		pci_mmcfg_config[i].end_bus_number = (1 << busnbits) - 1;
153 	}
154 
155 	return "AMD Family 10h NB";
156 }
157 
158 struct pci_mmcfg_hostbridge_probe {
159 	u32 bus;
160 	u32 devfn;
161 	u32 vendor;
162 	u32 device;
163 	const char *(*probe)(void);
164 };
165 
166 static struct pci_mmcfg_hostbridge_probe pci_mmcfg_probes[] __initdata = {
167 	{ 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_INTEL,
168 	  PCI_DEVICE_ID_INTEL_E7520_MCH, pci_mmcfg_e7520 },
169 	{ 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_INTEL,
170 	  PCI_DEVICE_ID_INTEL_82945G_HB, pci_mmcfg_intel_945 },
171 	{ 0, PCI_DEVFN(0x18, 0), PCI_VENDOR_ID_AMD,
172 	  0x1200, pci_mmcfg_amd_fam10h },
173 	{ 0xff, PCI_DEVFN(0, 0), PCI_VENDOR_ID_AMD,
174 	  0x1200, pci_mmcfg_amd_fam10h },
175 };
176 
177 static int __init pci_mmcfg_check_hostbridge(void)
178 {
179 	u32 l;
180 	u32 bus, devfn;
181 	u16 vendor, device;
182 	int i;
183 	const char *name;
184 
185 	if (!raw_pci_ops)
186 		return 0;
187 
188 	pci_mmcfg_config_num = 0;
189 	pci_mmcfg_config = NULL;
190 	name = NULL;
191 
192 	for (i = 0; !name && i < ARRAY_SIZE(pci_mmcfg_probes); i++) {
193 		bus =  pci_mmcfg_probes[i].bus;
194 		devfn = pci_mmcfg_probes[i].devfn;
195 		raw_pci_ops->read(0, bus, devfn, 0, 4, &l);
196 		vendor = l & 0xffff;
197 		device = (l >> 16) & 0xffff;
198 
199 		if (pci_mmcfg_probes[i].vendor == vendor &&
200 		    pci_mmcfg_probes[i].device == device)
201 			name = pci_mmcfg_probes[i].probe();
202 	}
203 
204 	if (name) {
205 		printk(KERN_INFO "PCI: Found %s %s MMCONFIG support.\n",
206 		       name, pci_mmcfg_config_num ? "with" : "without");
207 	}
208 
209 	return name != NULL;
210 }
211 
212 static void __init pci_mmcfg_insert_resources(void)
213 {
214 #define PCI_MMCFG_RESOURCE_NAME_LEN 19
215 	int i;
216 	struct resource *res;
217 	char *names;
218 	unsigned num_buses;
219 
220 	res = kcalloc(PCI_MMCFG_RESOURCE_NAME_LEN + sizeof(*res),
221 			pci_mmcfg_config_num, GFP_KERNEL);
222 	if (!res) {
223 		printk(KERN_ERR "PCI: Unable to allocate MMCONFIG resources\n");
224 		return;
225 	}
226 
227 	names = (void *)&res[pci_mmcfg_config_num];
228 	for (i = 0; i < pci_mmcfg_config_num; i++, res++) {
229 		struct acpi_mcfg_allocation *cfg = &pci_mmcfg_config[i];
230 		num_buses = cfg->end_bus_number - cfg->start_bus_number + 1;
231 		res->name = names;
232 		snprintf(names, PCI_MMCFG_RESOURCE_NAME_LEN, "PCI MMCONFIG %u",
233 			 cfg->pci_segment);
234 		res->start = cfg->address;
235 		res->end = res->start + (num_buses << 20) - 1;
236 		res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
237 		insert_resource(&iomem_resource, res);
238 		names += PCI_MMCFG_RESOURCE_NAME_LEN;
239 	}
240 
241 	/* Mark that the resources have been inserted. */
242 	pci_mmcfg_resources_inserted = 1;
243 }
244 
245 static acpi_status __init check_mcfg_resource(struct acpi_resource *res,
246 					      void *data)
247 {
248 	struct resource *mcfg_res = data;
249 	struct acpi_resource_address64 address;
250 	acpi_status status;
251 
252 	if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
253 		struct acpi_resource_fixed_memory32 *fixmem32 =
254 			&res->data.fixed_memory32;
255 		if (!fixmem32)
256 			return AE_OK;
257 		if ((mcfg_res->start >= fixmem32->address) &&
258 		    (mcfg_res->end < (fixmem32->address +
259 				      fixmem32->address_length))) {
260 			mcfg_res->flags = 1;
261 			return AE_CTRL_TERMINATE;
262 		}
263 	}
264 	if ((res->type != ACPI_RESOURCE_TYPE_ADDRESS32) &&
265 	    (res->type != ACPI_RESOURCE_TYPE_ADDRESS64))
266 		return AE_OK;
267 
268 	status = acpi_resource_to_address64(res, &address);
269 	if (ACPI_FAILURE(status) ||
270 	   (address.address_length <= 0) ||
271 	   (address.resource_type != ACPI_MEMORY_RANGE))
272 		return AE_OK;
273 
274 	if ((mcfg_res->start >= address.minimum) &&
275 	    (mcfg_res->end < (address.minimum + address.address_length))) {
276 		mcfg_res->flags = 1;
277 		return AE_CTRL_TERMINATE;
278 	}
279 	return AE_OK;
280 }
281 
282 static acpi_status __init find_mboard_resource(acpi_handle handle, u32 lvl,
283 		void *context, void **rv)
284 {
285 	struct resource *mcfg_res = context;
286 
287 	acpi_walk_resources(handle, METHOD_NAME__CRS,
288 			    check_mcfg_resource, context);
289 
290 	if (mcfg_res->flags)
291 		return AE_CTRL_TERMINATE;
292 
293 	return AE_OK;
294 }
295 
296 static int __init is_acpi_reserved(u64 start, u64 end, unsigned not_used)
297 {
298 	struct resource mcfg_res;
299 
300 	mcfg_res.start = start;
301 	mcfg_res.end = end;
302 	mcfg_res.flags = 0;
303 
304 	acpi_get_devices("PNP0C01", find_mboard_resource, &mcfg_res, NULL);
305 
306 	if (!mcfg_res.flags)
307 		acpi_get_devices("PNP0C02", find_mboard_resource, &mcfg_res,
308 				 NULL);
309 
310 	return mcfg_res.flags;
311 }
312 
313 typedef int (*check_reserved_t)(u64 start, u64 end, unsigned type);
314 
315 static int __init is_mmconf_reserved(check_reserved_t is_reserved,
316 		u64 addr, u64 size, int i,
317 		typeof(pci_mmcfg_config[0]) *cfg, int with_e820)
318 {
319 	u64 old_size = size;
320 	int valid = 0;
321 
322 	while (!is_reserved(addr, addr + size - 1, E820_RESERVED)) {
323 		size >>= 1;
324 		if (size < (16UL<<20))
325 			break;
326 	}
327 
328 	if (size >= (16UL<<20) || size == old_size) {
329 		printk(KERN_NOTICE
330 		       "PCI: MCFG area at %Lx reserved in %s\n",
331 			addr, with_e820?"E820":"ACPI motherboard resources");
332 		valid = 1;
333 
334 		if (old_size != size) {
335 			/* update end_bus_number */
336 			cfg->end_bus_number = cfg->start_bus_number + ((size>>20) - 1);
337 			printk(KERN_NOTICE "PCI: updated MCFG configuration %d: base %lx "
338 			       "segment %hu buses %u - %u\n",
339 			       i, (unsigned long)cfg->address, cfg->pci_segment,
340 			       (unsigned int)cfg->start_bus_number,
341 			       (unsigned int)cfg->end_bus_number);
342 		}
343 	}
344 
345 	return valid;
346 }
347 
348 static void __init pci_mmcfg_reject_broken(int early)
349 {
350 	typeof(pci_mmcfg_config[0]) *cfg;
351 	int i;
352 
353 	if ((pci_mmcfg_config_num == 0) ||
354 	    (pci_mmcfg_config == NULL) ||
355 	    (pci_mmcfg_config[0].address == 0))
356 		return;
357 
358 	cfg = &pci_mmcfg_config[0];
359 
360 	for (i = 0; i < pci_mmcfg_config_num; i++) {
361 		int valid = 0;
362 		u64 addr, size;
363 
364 		cfg = &pci_mmcfg_config[i];
365 		addr = cfg->start_bus_number;
366 		addr <<= 20;
367 		addr += cfg->address;
368 		size = cfg->end_bus_number + 1 - cfg->start_bus_number;
369 		size <<= 20;
370 		printk(KERN_NOTICE "PCI: MCFG configuration %d: base %lx "
371 		       "segment %hu buses %u - %u\n",
372 		       i, (unsigned long)cfg->address, cfg->pci_segment,
373 		       (unsigned int)cfg->start_bus_number,
374 		       (unsigned int)cfg->end_bus_number);
375 
376 		if (!early)
377 			valid = is_mmconf_reserved(is_acpi_reserved, addr, size, i, cfg, 0);
378 
379 		if (valid)
380 			continue;
381 
382 		if (!early)
383 			printk(KERN_ERR "PCI: BIOS Bug: MCFG area at %Lx is not"
384 			       " reserved in ACPI motherboard resources\n",
385 			       cfg->address);
386 
387 		/* Don't try to do this check unless configuration
388 		   type 1 is available. how about type 2 ?*/
389 		if (raw_pci_ops)
390 			valid = is_mmconf_reserved(e820_all_mapped, addr, size, i, cfg, 1);
391 
392 		if (!valid)
393 			goto reject;
394 	}
395 
396 	return;
397 
398 reject:
399 	printk(KERN_INFO "PCI: Not using MMCONFIG.\n");
400 	pci_mmcfg_arch_free();
401 	kfree(pci_mmcfg_config);
402 	pci_mmcfg_config = NULL;
403 	pci_mmcfg_config_num = 0;
404 }
405 
406 static int __initdata known_bridge;
407 
408 static void __init __pci_mmcfg_init(int early)
409 {
410 	/* MMCONFIG disabled */
411 	if ((pci_probe & PCI_PROBE_MMCONF) == 0)
412 		return;
413 
414 	/* MMCONFIG already enabled */
415 	if (!early && !(pci_probe & PCI_PROBE_MASK & ~PCI_PROBE_MMCONF))
416 		return;
417 
418 	/* for late to exit */
419 	if (known_bridge)
420 		return;
421 
422 	if (early) {
423 		if (pci_mmcfg_check_hostbridge())
424 			known_bridge = 1;
425 	}
426 
427 	if (!known_bridge) {
428 		acpi_table_parse(ACPI_SIG_MCFG, acpi_parse_mcfg);
429 		pci_mmcfg_reject_broken(early);
430 	}
431 
432 	if ((pci_mmcfg_config_num == 0) ||
433 	    (pci_mmcfg_config == NULL) ||
434 	    (pci_mmcfg_config[0].address == 0))
435 		return;
436 
437 	if (pci_mmcfg_arch_init())
438 		pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
439 	else {
440 		/*
441 		 * Signal not to attempt to insert mmcfg resources because
442 		 * the architecture mmcfg setup could not initialize.
443 		 */
444 		pci_mmcfg_resources_inserted = 1;
445 	}
446 }
447 
448 void __init pci_mmcfg_early_init(void)
449 {
450 	__pci_mmcfg_init(1);
451 }
452 
453 void __init pci_mmcfg_late_init(void)
454 {
455 	__pci_mmcfg_init(0);
456 }
457 
458 static int __init pci_mmcfg_late_insert_resources(void)
459 {
460 	/*
461 	 * If resources are already inserted or we are not using MMCONFIG,
462 	 * don't insert the resources.
463 	 */
464 	if ((pci_mmcfg_resources_inserted == 1) ||
465 	    (pci_probe & PCI_PROBE_MMCONF) == 0 ||
466 	    (pci_mmcfg_config_num == 0) ||
467 	    (pci_mmcfg_config == NULL) ||
468 	    (pci_mmcfg_config[0].address == 0))
469 		return 1;
470 
471 	/*
472 	 * Attempt to insert the mmcfg resources but not with the busy flag
473 	 * marked so it won't cause request errors when __request_region is
474 	 * called.
475 	 */
476 	pci_mmcfg_insert_resources();
477 
478 	return 0;
479 }
480 
481 /*
482  * Perform MMCONFIG resource insertion after PCI initialization to allow for
483  * misprogrammed MCFG tables that state larger sizes but actually conflict
484  * with other system resources.
485  */
486 late_initcall(pci_mmcfg_late_insert_resources);
487