xref: /openbmc/linux/drivers/firmware/dmi_scan.c (revision f15cbe6f1a4b4d9df59142fc8e4abb973302cf44)
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 /*
12  * DMI stands for "Desktop Management Interface".  It is part
13  * of and an antecedent to, SMBIOS, which stands for System
14  * Management BIOS.  See further: http://www.dmtf.org/standards
15  */
16 static char dmi_empty_string[] = "        ";
17 
18 static const char * __init dmi_string_nosave(const struct dmi_header *dm, u8 s)
19 {
20 	const u8 *bp = ((u8 *) dm) + dm->length;
21 
22 	if (s) {
23 		s--;
24 		while (s > 0 && *bp) {
25 			bp += strlen(bp) + 1;
26 			s--;
27 		}
28 
29 		if (*bp != 0) {
30 			size_t len = strlen(bp)+1;
31 			size_t cmp_len = len > 8 ? 8 : len;
32 
33 			if (!memcmp(bp, dmi_empty_string, cmp_len))
34 				return dmi_empty_string;
35 			return bp;
36 		}
37 	}
38 
39 	return "";
40 }
41 
42 static char * __init dmi_string(const struct dmi_header *dm, u8 s)
43 {
44 	const char *bp = dmi_string_nosave(dm, s);
45 	char *str;
46 	size_t len;
47 
48 	if (bp == dmi_empty_string)
49 		return dmi_empty_string;
50 
51 	len = strlen(bp) + 1;
52 	str = dmi_alloc(len);
53 	if (str != NULL)
54 		strcpy(str, bp);
55 	else
56 		printk(KERN_ERR "dmi_string: cannot allocate %Zu bytes.\n", len);
57 
58 	return str;
59 }
60 
61 /*
62  *	We have to be cautious here. We have seen BIOSes with DMI pointers
63  *	pointing to completely the wrong place for example
64  */
65 static void dmi_table(u8 *buf, int len, int num,
66 		      void (*decode)(const struct dmi_header *))
67 {
68 	u8 *data = buf;
69 	int i = 0;
70 
71 	/*
72 	 *	Stop when we see all the items the table claimed to have
73 	 *	OR we run off the end of the table (also happens)
74 	 */
75 	while ((i < num) && (data - buf + sizeof(struct dmi_header)) <= len) {
76 		const struct dmi_header *dm = (const struct dmi_header *)data;
77 
78 		/*
79 		 *  We want to know the total length (formated area and strings)
80 		 *  before decoding to make sure we won't run off the table in
81 		 *  dmi_decode or dmi_string
82 		 */
83 		data += dm->length;
84 		while ((data - buf < len - 1) && (data[0] || data[1]))
85 			data++;
86 		if (data - buf < len - 1)
87 			decode(dm);
88 		data += 2;
89 		i++;
90 	}
91 }
92 
93 static u32 dmi_base;
94 static u16 dmi_len;
95 static u16 dmi_num;
96 
97 static int __init dmi_walk_early(void (*decode)(const struct dmi_header *))
98 {
99 	u8 *buf;
100 
101 	buf = dmi_ioremap(dmi_base, dmi_len);
102 	if (buf == NULL)
103 		return -1;
104 
105 	dmi_table(buf, dmi_len, dmi_num, decode);
106 
107 	dmi_iounmap(buf, dmi_len);
108 	return 0;
109 }
110 
111 static int __init dmi_checksum(const u8 *buf)
112 {
113 	u8 sum = 0;
114 	int a;
115 
116 	for (a = 0; a < 15; a++)
117 		sum += buf[a];
118 
119 	return sum == 0;
120 }
121 
122 static char *dmi_ident[DMI_STRING_MAX];
123 static LIST_HEAD(dmi_devices);
124 int dmi_available;
125 
126 /*
127  *	Save a DMI string
128  */
129 static void __init dmi_save_ident(const struct dmi_header *dm, int slot, int string)
130 {
131 	const char *d = (const char*) dm;
132 	char *p;
133 
134 	if (dmi_ident[slot])
135 		return;
136 
137 	p = dmi_string(dm, d[string]);
138 	if (p == NULL)
139 		return;
140 
141 	dmi_ident[slot] = p;
142 }
143 
144 static void __init dmi_save_uuid(const struct dmi_header *dm, int slot, int index)
145 {
146 	const u8 *d = (u8*) dm + index;
147 	char *s;
148 	int is_ff = 1, is_00 = 1, i;
149 
150 	if (dmi_ident[slot])
151 		return;
152 
153 	for (i = 0; i < 16 && (is_ff || is_00); i++) {
154 		if(d[i] != 0x00) is_ff = 0;
155 		if(d[i] != 0xFF) is_00 = 0;
156 	}
157 
158 	if (is_ff || is_00)
159 		return;
160 
161 	s = dmi_alloc(16*2+4+1);
162 	if (!s)
163 		return;
164 
165 	sprintf(s,
166 		"%02X%02X%02X%02X-%02X%02X-%02X%02X-%02X%02X-%02X%02X%02X%02X%02X%02X",
167 		d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7],
168 		d[8], d[9], d[10], d[11], d[12], d[13], d[14], d[15]);
169 
170         dmi_ident[slot] = s;
171 }
172 
173 static void __init dmi_save_type(const struct dmi_header *dm, int slot, int index)
174 {
175 	const u8 *d = (u8*) dm + index;
176 	char *s;
177 
178 	if (dmi_ident[slot])
179 		return;
180 
181 	s = dmi_alloc(4);
182 	if (!s)
183 		return;
184 
185 	sprintf(s, "%u", *d & 0x7F);
186 	dmi_ident[slot] = s;
187 }
188 
189 static void __init dmi_save_one_device(int type, const char *name)
190 {
191 	struct dmi_device *dev;
192 
193 	/* No duplicate device */
194 	if (dmi_find_device(type, name, NULL))
195 		return;
196 
197 	dev = dmi_alloc(sizeof(*dev) + strlen(name) + 1);
198 	if (!dev) {
199 		printk(KERN_ERR "dmi_save_one_device: out of memory.\n");
200 		return;
201 	}
202 
203 	dev->type = type;
204 	strcpy((char *)(dev + 1), name);
205 	dev->name = (char *)(dev + 1);
206 	dev->device_data = NULL;
207 	list_add(&dev->list, &dmi_devices);
208 }
209 
210 static void __init dmi_save_devices(const struct dmi_header *dm)
211 {
212 	int i, count = (dm->length - sizeof(struct dmi_header)) / 2;
213 
214 	for (i = 0; i < count; i++) {
215 		const char *d = (char *)(dm + 1) + (i * 2);
216 
217 		/* Skip disabled device */
218 		if ((*d & 0x80) == 0)
219 			continue;
220 
221 		dmi_save_one_device(*d & 0x7f, dmi_string_nosave(dm, *(d + 1)));
222 	}
223 }
224 
225 static void __init dmi_save_oem_strings_devices(const struct dmi_header *dm)
226 {
227 	int i, count = *(u8 *)(dm + 1);
228 	struct dmi_device *dev;
229 
230 	for (i = 1; i <= count; i++) {
231 		char *devname = dmi_string(dm, i);
232 
233 		if (devname == dmi_empty_string)
234 			continue;
235 
236 		dev = dmi_alloc(sizeof(*dev));
237 		if (!dev) {
238 			printk(KERN_ERR
239 			   "dmi_save_oem_strings_devices: out of memory.\n");
240 			break;
241 		}
242 
243 		dev->type = DMI_DEV_TYPE_OEM_STRING;
244 		dev->name = devname;
245 		dev->device_data = NULL;
246 
247 		list_add(&dev->list, &dmi_devices);
248 	}
249 }
250 
251 static void __init dmi_save_ipmi_device(const struct dmi_header *dm)
252 {
253 	struct dmi_device *dev;
254 	void * data;
255 
256 	data = dmi_alloc(dm->length);
257 	if (data == NULL) {
258 		printk(KERN_ERR "dmi_save_ipmi_device: out of memory.\n");
259 		return;
260 	}
261 
262 	memcpy(data, dm, dm->length);
263 
264 	dev = dmi_alloc(sizeof(*dev));
265 	if (!dev) {
266 		printk(KERN_ERR "dmi_save_ipmi_device: out of memory.\n");
267 		return;
268 	}
269 
270 	dev->type = DMI_DEV_TYPE_IPMI;
271 	dev->name = "IPMI controller";
272 	dev->device_data = data;
273 
274 	list_add_tail(&dev->list, &dmi_devices);
275 }
276 
277 static void __init dmi_save_extended_devices(const struct dmi_header *dm)
278 {
279 	const u8 *d = (u8*) dm + 5;
280 
281 	/* Skip disabled device */
282 	if ((*d & 0x80) == 0)
283 		return;
284 
285 	dmi_save_one_device(*d & 0x7f, dmi_string_nosave(dm, *(d - 1)));
286 }
287 
288 /*
289  *	Process a DMI table entry. Right now all we care about are the BIOS
290  *	and machine entries. For 2.5 we should pull the smbus controller info
291  *	out of here.
292  */
293 static void __init dmi_decode(const struct dmi_header *dm)
294 {
295 	switch(dm->type) {
296 	case 0:		/* BIOS Information */
297 		dmi_save_ident(dm, DMI_BIOS_VENDOR, 4);
298 		dmi_save_ident(dm, DMI_BIOS_VERSION, 5);
299 		dmi_save_ident(dm, DMI_BIOS_DATE, 8);
300 		break;
301 	case 1:		/* System Information */
302 		dmi_save_ident(dm, DMI_SYS_VENDOR, 4);
303 		dmi_save_ident(dm, DMI_PRODUCT_NAME, 5);
304 		dmi_save_ident(dm, DMI_PRODUCT_VERSION, 6);
305 		dmi_save_ident(dm, DMI_PRODUCT_SERIAL, 7);
306 		dmi_save_uuid(dm, DMI_PRODUCT_UUID, 8);
307 		break;
308 	case 2:		/* Base Board Information */
309 		dmi_save_ident(dm, DMI_BOARD_VENDOR, 4);
310 		dmi_save_ident(dm, DMI_BOARD_NAME, 5);
311 		dmi_save_ident(dm, DMI_BOARD_VERSION, 6);
312 		dmi_save_ident(dm, DMI_BOARD_SERIAL, 7);
313 		dmi_save_ident(dm, DMI_BOARD_ASSET_TAG, 8);
314 		break;
315 	case 3:		/* Chassis Information */
316 		dmi_save_ident(dm, DMI_CHASSIS_VENDOR, 4);
317 		dmi_save_type(dm, DMI_CHASSIS_TYPE, 5);
318 		dmi_save_ident(dm, DMI_CHASSIS_VERSION, 6);
319 		dmi_save_ident(dm, DMI_CHASSIS_SERIAL, 7);
320 		dmi_save_ident(dm, DMI_CHASSIS_ASSET_TAG, 8);
321 		break;
322 	case 10:	/* Onboard Devices Information */
323 		dmi_save_devices(dm);
324 		break;
325 	case 11:	/* OEM Strings */
326 		dmi_save_oem_strings_devices(dm);
327 		break;
328 	case 38:	/* IPMI Device Information */
329 		dmi_save_ipmi_device(dm);
330 		break;
331 	case 41:	/* Onboard Devices Extended Information */
332 		dmi_save_extended_devices(dm);
333 	}
334 }
335 
336 static int __init dmi_present(const char __iomem *p)
337 {
338 	u8 buf[15];
339 
340 	memcpy_fromio(buf, p, 15);
341 	if ((memcmp(buf, "_DMI_", 5) == 0) && dmi_checksum(buf)) {
342 		dmi_num = (buf[13] << 8) | buf[12];
343 		dmi_len = (buf[7] << 8) | buf[6];
344 		dmi_base = (buf[11] << 24) | (buf[10] << 16) |
345 			(buf[9] << 8) | buf[8];
346 
347 		/*
348 		 * DMI version 0.0 means that the real version is taken from
349 		 * the SMBIOS version, which we don't know at this point.
350 		 */
351 		if (buf[14] != 0)
352 			printk(KERN_INFO "DMI %d.%d present.\n",
353 			       buf[14] >> 4, buf[14] & 0xF);
354 		else
355 			printk(KERN_INFO "DMI present.\n");
356 		if (dmi_walk_early(dmi_decode) == 0)
357 			return 0;
358 	}
359 	return 1;
360 }
361 
362 void __init dmi_scan_machine(void)
363 {
364 	char __iomem *p, *q;
365 	int rc;
366 
367 	if (efi_enabled) {
368 		if (efi.smbios == EFI_INVALID_TABLE_ADDR)
369 			goto out;
370 
371 		/* This is called as a core_initcall() because it isn't
372 		 * needed during early boot.  This also means we can
373 		 * iounmap the space when we're done with it.
374 		 */
375 		p = dmi_ioremap(efi.smbios, 32);
376 		if (p == NULL)
377 			goto out;
378 
379 		rc = dmi_present(p + 0x10); /* offset of _DMI_ string */
380 		dmi_iounmap(p, 32);
381 		if (!rc) {
382 			dmi_available = 1;
383 			return;
384 		}
385 	}
386 	else {
387 		/*
388 		 * no iounmap() for that ioremap(); it would be a no-op, but
389 		 * it's so early in setup that sucker gets confused into doing
390 		 * what it shouldn't if we actually call it.
391 		 */
392 		p = dmi_ioremap(0xF0000, 0x10000);
393 		if (p == NULL)
394 			goto out;
395 
396 		for (q = p; q < p + 0x10000; q += 16) {
397 			rc = dmi_present(q);
398 			if (!rc) {
399 				dmi_available = 1;
400 				dmi_iounmap(p, 0x10000);
401 				return;
402 			}
403 		}
404 		dmi_iounmap(p, 0x10000);
405 	}
406  out:	printk(KERN_INFO "DMI not present or invalid.\n");
407 }
408 
409 /**
410  *	dmi_check_system - check system DMI data
411  *	@list: array of dmi_system_id structures to match against
412  *		All non-null elements of the list must match
413  *		their slot's (field index's) data (i.e., each
414  *		list string must be a substring of the specified
415  *		DMI slot's string data) to be considered a
416  *		successful match.
417  *
418  *	Walk the blacklist table running matching functions until someone
419  *	returns non zero or we hit the end. Callback function is called for
420  *	each successful match. Returns the number of matches.
421  */
422 int dmi_check_system(const struct dmi_system_id *list)
423 {
424 	int i, count = 0;
425 	const struct dmi_system_id *d = list;
426 
427 	while (d->ident) {
428 		for (i = 0; i < ARRAY_SIZE(d->matches); i++) {
429 			int s = d->matches[i].slot;
430 			if (s == DMI_NONE)
431 				continue;
432 			if (dmi_ident[s] && strstr(dmi_ident[s], d->matches[i].substr))
433 				continue;
434 			/* No match */
435 			goto fail;
436 		}
437 		count++;
438 		if (d->callback && d->callback(d))
439 			break;
440 fail:		d++;
441 	}
442 
443 	return count;
444 }
445 EXPORT_SYMBOL(dmi_check_system);
446 
447 /**
448  *	dmi_get_system_info - return DMI data value
449  *	@field: data index (see enum dmi_field)
450  *
451  *	Returns one DMI data value, can be used to perform
452  *	complex DMI data checks.
453  */
454 const char *dmi_get_system_info(int field)
455 {
456 	return dmi_ident[field];
457 }
458 EXPORT_SYMBOL(dmi_get_system_info);
459 
460 
461 /**
462  *	dmi_name_in_vendors - Check if string is anywhere in the DMI vendor information.
463  *	@str: 	Case sensitive Name
464  */
465 int dmi_name_in_vendors(const char *str)
466 {
467 	static int fields[] = { DMI_BIOS_VENDOR, DMI_BIOS_VERSION, DMI_SYS_VENDOR,
468 				DMI_PRODUCT_NAME, DMI_PRODUCT_VERSION, DMI_BOARD_VENDOR,
469 				DMI_BOARD_NAME, DMI_BOARD_VERSION, DMI_NONE };
470 	int i;
471 	for (i = 0; fields[i] != DMI_NONE; i++) {
472 		int f = fields[i];
473 		if (dmi_ident[f] && strstr(dmi_ident[f], str))
474 			return 1;
475 	}
476 	return 0;
477 }
478 EXPORT_SYMBOL(dmi_name_in_vendors);
479 
480 /**
481  *	dmi_find_device - find onboard device by type/name
482  *	@type: device type or %DMI_DEV_TYPE_ANY to match all device types
483  *	@name: device name string or %NULL to match all
484  *	@from: previous device found in search, or %NULL for new search.
485  *
486  *	Iterates through the list of known onboard devices. If a device is
487  *	found with a matching @vendor and @device, a pointer to its device
488  *	structure is returned.  Otherwise, %NULL is returned.
489  *	A new search is initiated by passing %NULL as the @from argument.
490  *	If @from is not %NULL, searches continue from next device.
491  */
492 const struct dmi_device * dmi_find_device(int type, const char *name,
493 				    const struct dmi_device *from)
494 {
495 	const struct list_head *head = from ? &from->list : &dmi_devices;
496 	struct list_head *d;
497 
498 	for(d = head->next; d != &dmi_devices; d = d->next) {
499 		const struct dmi_device *dev =
500 			list_entry(d, struct dmi_device, list);
501 
502 		if (((type == DMI_DEV_TYPE_ANY) || (dev->type == type)) &&
503 		    ((name == NULL) || (strcmp(dev->name, name) == 0)))
504 			return dev;
505 	}
506 
507 	return NULL;
508 }
509 EXPORT_SYMBOL(dmi_find_device);
510 
511 /**
512  *	dmi_get_year - Return year of a DMI date
513  *	@field:	data index (like dmi_get_system_info)
514  *
515  *	Returns -1 when the field doesn't exist. 0 when it is broken.
516  */
517 int dmi_get_year(int field)
518 {
519 	int year;
520 	const char *s = dmi_get_system_info(field);
521 
522 	if (!s)
523 		return -1;
524 	if (*s == '\0')
525 		return 0;
526 	s = strrchr(s, '/');
527 	if (!s)
528 		return 0;
529 
530 	s += 1;
531 	year = simple_strtoul(s, NULL, 0);
532 	if (year && year < 100) {	/* 2-digit year */
533 		year += 1900;
534 		if (year < 1996)	/* no dates < spec 1.0 */
535 			year += 100;
536 	}
537 
538 	return year;
539 }
540 
541 /**
542  *	dmi_walk - Walk the DMI table and get called back for every record
543  *	@decode: Callback function
544  *
545  *	Returns -1 when the DMI table can't be reached, 0 on success.
546  */
547 int dmi_walk(void (*decode)(const struct dmi_header *))
548 {
549 	u8 *buf;
550 
551 	if (!dmi_available)
552 		return -1;
553 
554 	buf = ioremap(dmi_base, dmi_len);
555 	if (buf == NULL)
556 		return -1;
557 
558 	dmi_table(buf, dmi_len, dmi_num, decode);
559 
560 	iounmap(buf);
561 	return 0;
562 }
563 EXPORT_SYMBOL_GPL(dmi_walk);
564