xref: /openbmc/linux/drivers/firmware/dmi_scan.c (revision 22246614)
1 #include <linux/types.h>
2 #include <linux/string.h>
3 #include <linux/init.h>
4 #include <linux/module.h>
5 #include <linux/dmi.h>
6 #include <linux/efi.h>
7 #include <linux/bootmem.h>
8 #include <linux/slab.h>
9 #include <asm/dmi.h>
10 
11 static char dmi_empty_string[] = "        ";
12 
13 static const char * __init dmi_string_nosave(const struct dmi_header *dm, u8 s)
14 {
15 	const u8 *bp = ((u8 *) dm) + dm->length;
16 
17 	if (s) {
18 		s--;
19 		while (s > 0 && *bp) {
20 			bp += strlen(bp) + 1;
21 			s--;
22 		}
23 
24 		if (*bp != 0) {
25 			size_t len = strlen(bp)+1;
26 			size_t cmp_len = len > 8 ? 8 : len;
27 
28 			if (!memcmp(bp, dmi_empty_string, cmp_len))
29 				return dmi_empty_string;
30 			return bp;
31 		}
32 	}
33 
34 	return "";
35 }
36 
37 static char * __init dmi_string(const struct dmi_header *dm, u8 s)
38 {
39 	const char *bp = dmi_string_nosave(dm, s);
40 	char *str;
41 	size_t len;
42 
43 	if (bp == dmi_empty_string)
44 		return dmi_empty_string;
45 
46 	len = strlen(bp) + 1;
47 	str = dmi_alloc(len);
48 	if (str != NULL)
49 		strcpy(str, bp);
50 	else
51 		printk(KERN_ERR "dmi_string: cannot allocate %Zu bytes.\n", len);
52 
53 	return str;
54 }
55 
56 /*
57  *	We have to be cautious here. We have seen BIOSes with DMI pointers
58  *	pointing to completely the wrong place for example
59  */
60 static void dmi_table(u8 *buf, int len, int num,
61 		      void (*decode)(const struct dmi_header *))
62 {
63 	u8 *data = buf;
64 	int i = 0;
65 
66 	/*
67 	 *	Stop when we see all the items the table claimed to have
68 	 *	OR we run off the end of the table (also happens)
69 	 */
70 	while ((i < num) && (data - buf + sizeof(struct dmi_header)) <= len) {
71 		const struct dmi_header *dm = (const struct dmi_header *)data;
72 
73 		/*
74 		 *  We want to know the total length (formated area and strings)
75 		 *  before decoding to make sure we won't run off the table in
76 		 *  dmi_decode or dmi_string
77 		 */
78 		data += dm->length;
79 		while ((data - buf < len - 1) && (data[0] || data[1]))
80 			data++;
81 		if (data - buf < len - 1)
82 			decode(dm);
83 		data += 2;
84 		i++;
85 	}
86 }
87 
88 static u32 dmi_base;
89 static u16 dmi_len;
90 static u16 dmi_num;
91 
92 static int __init dmi_walk_early(void (*decode)(const struct dmi_header *))
93 {
94 	u8 *buf;
95 
96 	buf = dmi_ioremap(dmi_base, dmi_len);
97 	if (buf == NULL)
98 		return -1;
99 
100 	dmi_table(buf, dmi_len, dmi_num, decode);
101 
102 	dmi_iounmap(buf, dmi_len);
103 	return 0;
104 }
105 
106 static int __init dmi_checksum(const u8 *buf)
107 {
108 	u8 sum = 0;
109 	int a;
110 
111 	for (a = 0; a < 15; a++)
112 		sum += buf[a];
113 
114 	return sum == 0;
115 }
116 
117 static char *dmi_ident[DMI_STRING_MAX];
118 static LIST_HEAD(dmi_devices);
119 int dmi_available;
120 
121 /*
122  *	Save a DMI string
123  */
124 static void __init dmi_save_ident(const struct dmi_header *dm, int slot, int string)
125 {
126 	const char *d = (const char*) dm;
127 	char *p;
128 
129 	if (dmi_ident[slot])
130 		return;
131 
132 	p = dmi_string(dm, d[string]);
133 	if (p == NULL)
134 		return;
135 
136 	dmi_ident[slot] = p;
137 }
138 
139 static void __init dmi_save_uuid(const struct dmi_header *dm, int slot, int index)
140 {
141 	const u8 *d = (u8*) dm + index;
142 	char *s;
143 	int is_ff = 1, is_00 = 1, i;
144 
145 	if (dmi_ident[slot])
146 		return;
147 
148 	for (i = 0; i < 16 && (is_ff || is_00); i++) {
149 		if(d[i] != 0x00) is_ff = 0;
150 		if(d[i] != 0xFF) is_00 = 0;
151 	}
152 
153 	if (is_ff || is_00)
154 		return;
155 
156 	s = dmi_alloc(16*2+4+1);
157 	if (!s)
158 		return;
159 
160 	sprintf(s,
161 		"%02X%02X%02X%02X-%02X%02X-%02X%02X-%02X%02X-%02X%02X%02X%02X%02X%02X",
162 		d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7],
163 		d[8], d[9], d[10], d[11], d[12], d[13], d[14], d[15]);
164 
165         dmi_ident[slot] = s;
166 }
167 
168 static void __init dmi_save_type(const struct dmi_header *dm, int slot, int index)
169 {
170 	const u8 *d = (u8*) dm + index;
171 	char *s;
172 
173 	if (dmi_ident[slot])
174 		return;
175 
176 	s = dmi_alloc(4);
177 	if (!s)
178 		return;
179 
180 	sprintf(s, "%u", *d & 0x7F);
181 	dmi_ident[slot] = s;
182 }
183 
184 static void __init dmi_save_one_device(int type, const char *name)
185 {
186 	struct dmi_device *dev;
187 
188 	/* No duplicate device */
189 	if (dmi_find_device(type, name, NULL))
190 		return;
191 
192 	dev = dmi_alloc(sizeof(*dev) + strlen(name) + 1);
193 	if (!dev) {
194 		printk(KERN_ERR "dmi_save_one_device: out of memory.\n");
195 		return;
196 	}
197 
198 	dev->type = type;
199 	strcpy((char *)(dev + 1), name);
200 	dev->name = (char *)(dev + 1);
201 	dev->device_data = NULL;
202 	list_add(&dev->list, &dmi_devices);
203 }
204 
205 static void __init dmi_save_devices(const struct dmi_header *dm)
206 {
207 	int i, count = (dm->length - sizeof(struct dmi_header)) / 2;
208 
209 	for (i = 0; i < count; i++) {
210 		const char *d = (char *)(dm + 1) + (i * 2);
211 
212 		/* Skip disabled device */
213 		if ((*d & 0x80) == 0)
214 			continue;
215 
216 		dmi_save_one_device(*d & 0x7f, dmi_string_nosave(dm, *(d + 1)));
217 	}
218 }
219 
220 static void __init dmi_save_oem_strings_devices(const struct dmi_header *dm)
221 {
222 	int i, count = *(u8 *)(dm + 1);
223 	struct dmi_device *dev;
224 
225 	for (i = 1; i <= count; i++) {
226 		char *devname = dmi_string(dm, i);
227 
228 		if (devname == dmi_empty_string)
229 			continue;
230 
231 		dev = dmi_alloc(sizeof(*dev));
232 		if (!dev) {
233 			printk(KERN_ERR
234 			   "dmi_save_oem_strings_devices: out of memory.\n");
235 			break;
236 		}
237 
238 		dev->type = DMI_DEV_TYPE_OEM_STRING;
239 		dev->name = devname;
240 		dev->device_data = NULL;
241 
242 		list_add(&dev->list, &dmi_devices);
243 	}
244 }
245 
246 static void __init dmi_save_ipmi_device(const struct dmi_header *dm)
247 {
248 	struct dmi_device *dev;
249 	void * data;
250 
251 	data = dmi_alloc(dm->length);
252 	if (data == NULL) {
253 		printk(KERN_ERR "dmi_save_ipmi_device: out of memory.\n");
254 		return;
255 	}
256 
257 	memcpy(data, dm, dm->length);
258 
259 	dev = dmi_alloc(sizeof(*dev));
260 	if (!dev) {
261 		printk(KERN_ERR "dmi_save_ipmi_device: out of memory.\n");
262 		return;
263 	}
264 
265 	dev->type = DMI_DEV_TYPE_IPMI;
266 	dev->name = "IPMI controller";
267 	dev->device_data = data;
268 
269 	list_add_tail(&dev->list, &dmi_devices);
270 }
271 
272 static void __init dmi_save_extended_devices(const struct dmi_header *dm)
273 {
274 	const u8 *d = (u8*) dm + 5;
275 
276 	/* Skip disabled device */
277 	if ((*d & 0x80) == 0)
278 		return;
279 
280 	dmi_save_one_device(*d & 0x7f, dmi_string_nosave(dm, *(d - 1)));
281 }
282 
283 /*
284  *	Process a DMI table entry. Right now all we care about are the BIOS
285  *	and machine entries. For 2.5 we should pull the smbus controller info
286  *	out of here.
287  */
288 static void __init dmi_decode(const struct dmi_header *dm)
289 {
290 	switch(dm->type) {
291 	case 0:		/* BIOS Information */
292 		dmi_save_ident(dm, DMI_BIOS_VENDOR, 4);
293 		dmi_save_ident(dm, DMI_BIOS_VERSION, 5);
294 		dmi_save_ident(dm, DMI_BIOS_DATE, 8);
295 		break;
296 	case 1:		/* System Information */
297 		dmi_save_ident(dm, DMI_SYS_VENDOR, 4);
298 		dmi_save_ident(dm, DMI_PRODUCT_NAME, 5);
299 		dmi_save_ident(dm, DMI_PRODUCT_VERSION, 6);
300 		dmi_save_ident(dm, DMI_PRODUCT_SERIAL, 7);
301 		dmi_save_uuid(dm, DMI_PRODUCT_UUID, 8);
302 		break;
303 	case 2:		/* Base Board Information */
304 		dmi_save_ident(dm, DMI_BOARD_VENDOR, 4);
305 		dmi_save_ident(dm, DMI_BOARD_NAME, 5);
306 		dmi_save_ident(dm, DMI_BOARD_VERSION, 6);
307 		dmi_save_ident(dm, DMI_BOARD_SERIAL, 7);
308 		dmi_save_ident(dm, DMI_BOARD_ASSET_TAG, 8);
309 		break;
310 	case 3:		/* Chassis Information */
311 		dmi_save_ident(dm, DMI_CHASSIS_VENDOR, 4);
312 		dmi_save_type(dm, DMI_CHASSIS_TYPE, 5);
313 		dmi_save_ident(dm, DMI_CHASSIS_VERSION, 6);
314 		dmi_save_ident(dm, DMI_CHASSIS_SERIAL, 7);
315 		dmi_save_ident(dm, DMI_CHASSIS_ASSET_TAG, 8);
316 		break;
317 	case 10:	/* Onboard Devices Information */
318 		dmi_save_devices(dm);
319 		break;
320 	case 11:	/* OEM Strings */
321 		dmi_save_oem_strings_devices(dm);
322 		break;
323 	case 38:	/* IPMI Device Information */
324 		dmi_save_ipmi_device(dm);
325 		break;
326 	case 41:	/* Onboard Devices Extended Information */
327 		dmi_save_extended_devices(dm);
328 	}
329 }
330 
331 static int __init dmi_present(const char __iomem *p)
332 {
333 	u8 buf[15];
334 
335 	memcpy_fromio(buf, p, 15);
336 	if ((memcmp(buf, "_DMI_", 5) == 0) && dmi_checksum(buf)) {
337 		dmi_num = (buf[13] << 8) | buf[12];
338 		dmi_len = (buf[7] << 8) | buf[6];
339 		dmi_base = (buf[11] << 24) | (buf[10] << 16) |
340 			(buf[9] << 8) | buf[8];
341 
342 		/*
343 		 * DMI version 0.0 means that the real version is taken from
344 		 * the SMBIOS version, which we don't know at this point.
345 		 */
346 		if (buf[14] != 0)
347 			printk(KERN_INFO "DMI %d.%d present.\n",
348 			       buf[14] >> 4, buf[14] & 0xF);
349 		else
350 			printk(KERN_INFO "DMI present.\n");
351 		if (dmi_walk_early(dmi_decode) == 0)
352 			return 0;
353 	}
354 	return 1;
355 }
356 
357 void __init dmi_scan_machine(void)
358 {
359 	char __iomem *p, *q;
360 	int rc;
361 
362 	if (efi_enabled) {
363 		if (efi.smbios == EFI_INVALID_TABLE_ADDR)
364 			goto out;
365 
366 		/* This is called as a core_initcall() because it isn't
367 		 * needed during early boot.  This also means we can
368 		 * iounmap the space when we're done with it.
369 		 */
370 		p = dmi_ioremap(efi.smbios, 32);
371 		if (p == NULL)
372 			goto out;
373 
374 		rc = dmi_present(p + 0x10); /* offset of _DMI_ string */
375 		dmi_iounmap(p, 32);
376 		if (!rc) {
377 			dmi_available = 1;
378 			return;
379 		}
380 	}
381 	else {
382 		/*
383 		 * no iounmap() for that ioremap(); it would be a no-op, but
384 		 * it's so early in setup that sucker gets confused into doing
385 		 * what it shouldn't if we actually call it.
386 		 */
387 		p = dmi_ioremap(0xF0000, 0x10000);
388 		if (p == NULL)
389 			goto out;
390 
391 		for (q = p; q < p + 0x10000; q += 16) {
392 			rc = dmi_present(q);
393 			if (!rc) {
394 				dmi_available = 1;
395 				dmi_iounmap(p, 0x10000);
396 				return;
397 			}
398 		}
399 		dmi_iounmap(p, 0x10000);
400 	}
401  out:	printk(KERN_INFO "DMI not present or invalid.\n");
402 }
403 
404 /**
405  *	dmi_check_system - check system DMI data
406  *	@list: array of dmi_system_id structures to match against
407  *		All non-null elements of the list must match
408  *		their slot's (field index's) data (i.e., each
409  *		list string must be a substring of the specified
410  *		DMI slot's string data) to be considered a
411  *		successful match.
412  *
413  *	Walk the blacklist table running matching functions until someone
414  *	returns non zero or we hit the end. Callback function is called for
415  *	each successful match. Returns the number of matches.
416  */
417 int dmi_check_system(const struct dmi_system_id *list)
418 {
419 	int i, count = 0;
420 	const struct dmi_system_id *d = list;
421 
422 	while (d->ident) {
423 		for (i = 0; i < ARRAY_SIZE(d->matches); i++) {
424 			int s = d->matches[i].slot;
425 			if (s == DMI_NONE)
426 				continue;
427 			if (dmi_ident[s] && strstr(dmi_ident[s], d->matches[i].substr))
428 				continue;
429 			/* No match */
430 			goto fail;
431 		}
432 		count++;
433 		if (d->callback && d->callback(d))
434 			break;
435 fail:		d++;
436 	}
437 
438 	return count;
439 }
440 EXPORT_SYMBOL(dmi_check_system);
441 
442 /**
443  *	dmi_get_system_info - return DMI data value
444  *	@field: data index (see enum dmi_field)
445  *
446  *	Returns one DMI data value, can be used to perform
447  *	complex DMI data checks.
448  */
449 const char *dmi_get_system_info(int field)
450 {
451 	return dmi_ident[field];
452 }
453 EXPORT_SYMBOL(dmi_get_system_info);
454 
455 
456 /**
457  *	dmi_name_in_vendors - Check if string is anywhere in the DMI vendor information.
458  *	@str: 	Case sensitive Name
459  */
460 int dmi_name_in_vendors(const char *str)
461 {
462 	static int fields[] = { DMI_BIOS_VENDOR, DMI_BIOS_VERSION, DMI_SYS_VENDOR,
463 				DMI_PRODUCT_NAME, DMI_PRODUCT_VERSION, DMI_BOARD_VENDOR,
464 				DMI_BOARD_NAME, DMI_BOARD_VERSION, DMI_NONE };
465 	int i;
466 	for (i = 0; fields[i] != DMI_NONE; i++) {
467 		int f = fields[i];
468 		if (dmi_ident[f] && strstr(dmi_ident[f], str))
469 			return 1;
470 	}
471 	return 0;
472 }
473 EXPORT_SYMBOL(dmi_name_in_vendors);
474 
475 /**
476  *	dmi_find_device - find onboard device by type/name
477  *	@type: device type or %DMI_DEV_TYPE_ANY to match all device types
478  *	@name: device name string or %NULL to match all
479  *	@from: previous device found in search, or %NULL for new search.
480  *
481  *	Iterates through the list of known onboard devices. If a device is
482  *	found with a matching @vendor and @device, a pointer to its device
483  *	structure is returned.  Otherwise, %NULL is returned.
484  *	A new search is initiated by passing %NULL as the @from argument.
485  *	If @from is not %NULL, searches continue from next device.
486  */
487 const struct dmi_device * dmi_find_device(int type, const char *name,
488 				    const struct dmi_device *from)
489 {
490 	const struct list_head *head = from ? &from->list : &dmi_devices;
491 	struct list_head *d;
492 
493 	for(d = head->next; d != &dmi_devices; d = d->next) {
494 		const struct dmi_device *dev =
495 			list_entry(d, struct dmi_device, list);
496 
497 		if (((type == DMI_DEV_TYPE_ANY) || (dev->type == type)) &&
498 		    ((name == NULL) || (strcmp(dev->name, name) == 0)))
499 			return dev;
500 	}
501 
502 	return NULL;
503 }
504 EXPORT_SYMBOL(dmi_find_device);
505 
506 /**
507  *	dmi_get_year - Return year of a DMI date
508  *	@field:	data index (like dmi_get_system_info)
509  *
510  *	Returns -1 when the field doesn't exist. 0 when it is broken.
511  */
512 int dmi_get_year(int field)
513 {
514 	int year;
515 	const char *s = dmi_get_system_info(field);
516 
517 	if (!s)
518 		return -1;
519 	if (*s == '\0')
520 		return 0;
521 	s = strrchr(s, '/');
522 	if (!s)
523 		return 0;
524 
525 	s += 1;
526 	year = simple_strtoul(s, NULL, 0);
527 	if (year && year < 100) {	/* 2-digit year */
528 		year += 1900;
529 		if (year < 1996)	/* no dates < spec 1.0 */
530 			year += 100;
531 	}
532 
533 	return year;
534 }
535 
536 /**
537  *	dmi_walk - Walk the DMI table and get called back for every record
538  *	@decode: Callback function
539  *
540  *	Returns -1 when the DMI table can't be reached, 0 on success.
541  */
542 int dmi_walk(void (*decode)(const struct dmi_header *))
543 {
544 	u8 *buf;
545 
546 	if (!dmi_available)
547 		return -1;
548 
549 	buf = ioremap(dmi_base, dmi_len);
550 	if (buf == NULL)
551 		return -1;
552 
553 	dmi_table(buf, dmi_len, dmi_num, decode);
554 
555 	iounmap(buf);
556 	return 0;
557 }
558 EXPORT_SYMBOL_GPL(dmi_walk);
559