xref: /linux/drivers/firmware/dmi_scan.c (revision 498ade1a133dffd0f3ee90952737045d56e6689a)
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 char * __init dmi_string(const struct dmi_header *dm, u8 s)
14 {
15 	const u8 *bp = ((u8 *) dm) + dm->length;
16 	char *str = "";
17 
18 	if (s) {
19 		s--;
20 		while (s > 0 && *bp) {
21 			bp += strlen(bp) + 1;
22 			s--;
23 		}
24 
25 		if (*bp != 0) {
26 			size_t len = strlen(bp)+1;
27 			size_t cmp_len = len > 8 ? 8 : len;
28 
29 			if (!memcmp(bp, dmi_empty_string, cmp_len))
30 				return dmi_empty_string;
31 			str = dmi_alloc(len);
32 			if (str != NULL)
33 				strcpy(str, bp);
34 			else
35 				printk(KERN_ERR "dmi_string: cannot allocate %Zu bytes.\n", len);
36 		}
37 	}
38 
39 	return str;
40 }
41 
42 /*
43  *	We have to be cautious here. We have seen BIOSes with DMI pointers
44  *	pointing to completely the wrong place for example
45  */
46 static int __init dmi_table(u32 base, int len, int num,
47 			    void (*decode)(const struct dmi_header *))
48 {
49 	u8 *buf, *data;
50 	int i = 0;
51 
52 	buf = dmi_ioremap(base, len);
53 	if (buf == NULL)
54 		return -1;
55 
56 	data = buf;
57 
58 	/*
59 	 *	Stop when we see all the items the table claimed to have
60 	 *	OR we run off the end of the table (also happens)
61 	 */
62 	while ((i < num) && (data - buf + sizeof(struct dmi_header)) <= len) {
63 		const struct dmi_header *dm = (const struct dmi_header *)data;
64 
65 		/*
66 		 *  We want to know the total length (formated area and strings)
67 		 *  before decoding to make sure we won't run off the table in
68 		 *  dmi_decode or dmi_string
69 		 */
70 		data += dm->length;
71 		while ((data - buf < len - 1) && (data[0] || data[1]))
72 			data++;
73 		if (data - buf < len - 1)
74 			decode(dm);
75 		data += 2;
76 		i++;
77 	}
78 	dmi_iounmap(buf, len);
79 	return 0;
80 }
81 
82 static int __init dmi_checksum(const u8 *buf)
83 {
84 	u8 sum = 0;
85 	int a;
86 
87 	for (a = 0; a < 15; a++)
88 		sum += buf[a];
89 
90 	return sum == 0;
91 }
92 
93 static char *dmi_ident[DMI_STRING_MAX];
94 static LIST_HEAD(dmi_devices);
95 int dmi_available;
96 
97 /*
98  *	Save a DMI string
99  */
100 static void __init dmi_save_ident(const struct dmi_header *dm, int slot, int string)
101 {
102 	const char *d = (const char*) dm;
103 	char *p;
104 
105 	if (dmi_ident[slot])
106 		return;
107 
108 	p = dmi_string(dm, d[string]);
109 	if (p == NULL)
110 		return;
111 
112 	dmi_ident[slot] = p;
113 }
114 
115 static void __init dmi_save_uuid(const struct dmi_header *dm, int slot, int index)
116 {
117 	const u8 *d = (u8*) dm + index;
118 	char *s;
119 	int is_ff = 1, is_00 = 1, i;
120 
121 	if (dmi_ident[slot])
122 		return;
123 
124 	for (i = 0; i < 16 && (is_ff || is_00); i++) {
125 		if(d[i] != 0x00) is_ff = 0;
126 		if(d[i] != 0xFF) is_00 = 0;
127 	}
128 
129 	if (is_ff || is_00)
130 		return;
131 
132 	s = dmi_alloc(16*2+4+1);
133 	if (!s)
134 		return;
135 
136 	sprintf(s,
137 		"%02X%02X%02X%02X-%02X%02X-%02X%02X-%02X%02X-%02X%02X%02X%02X%02X%02X",
138 		d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7],
139 		d[8], d[9], d[10], d[11], d[12], d[13], d[14], d[15]);
140 
141         dmi_ident[slot] = s;
142 }
143 
144 static void __init dmi_save_type(const struct dmi_header *dm, int slot, int index)
145 {
146 	const u8 *d = (u8*) dm + index;
147 	char *s;
148 
149 	if (dmi_ident[slot])
150 		return;
151 
152 	s = dmi_alloc(4);
153 	if (!s)
154 		return;
155 
156 	sprintf(s, "%u", *d & 0x7F);
157 	dmi_ident[slot] = s;
158 }
159 
160 static void __init dmi_save_devices(const struct dmi_header *dm)
161 {
162 	int i, count = (dm->length - sizeof(struct dmi_header)) / 2;
163 	struct dmi_device *dev;
164 
165 	for (i = 0; i < count; i++) {
166 		const char *d = (char *)(dm + 1) + (i * 2);
167 
168 		/* Skip disabled device */
169 		if ((*d & 0x80) == 0)
170 			continue;
171 
172 		dev = dmi_alloc(sizeof(*dev));
173 		if (!dev) {
174 			printk(KERN_ERR "dmi_save_devices: out of memory.\n");
175 			break;
176 		}
177 
178 		dev->type = *d++ & 0x7f;
179 		dev->name = dmi_string(dm, *d);
180 		dev->device_data = NULL;
181 		list_add(&dev->list, &dmi_devices);
182 	}
183 }
184 
185 static struct dmi_device empty_oem_string_dev = {
186 	.name = dmi_empty_string,
187 };
188 
189 static void __init dmi_save_oem_strings_devices(const struct dmi_header *dm)
190 {
191 	int i, count = *(u8 *)(dm + 1);
192 	struct dmi_device *dev;
193 
194 	for (i = 1; i <= count; i++) {
195 		char *devname = dmi_string(dm, i);
196 
197 		if (!strcmp(devname, dmi_empty_string)) {
198 			list_add(&empty_oem_string_dev.list, &dmi_devices);
199 			continue;
200 		}
201 
202 		dev = dmi_alloc(sizeof(*dev));
203 		if (!dev) {
204 			printk(KERN_ERR
205 			   "dmi_save_oem_strings_devices: out of memory.\n");
206 			break;
207 		}
208 
209 		dev->type = DMI_DEV_TYPE_OEM_STRING;
210 		dev->name = devname;
211 		dev->device_data = NULL;
212 
213 		list_add(&dev->list, &dmi_devices);
214 	}
215 }
216 
217 static void __init dmi_save_ipmi_device(const struct dmi_header *dm)
218 {
219 	struct dmi_device *dev;
220 	void * data;
221 
222 	data = dmi_alloc(dm->length);
223 	if (data == NULL) {
224 		printk(KERN_ERR "dmi_save_ipmi_device: out of memory.\n");
225 		return;
226 	}
227 
228 	memcpy(data, dm, dm->length);
229 
230 	dev = dmi_alloc(sizeof(*dev));
231 	if (!dev) {
232 		printk(KERN_ERR "dmi_save_ipmi_device: out of memory.\n");
233 		return;
234 	}
235 
236 	dev->type = DMI_DEV_TYPE_IPMI;
237 	dev->name = "IPMI controller";
238 	dev->device_data = data;
239 
240 	list_add(&dev->list, &dmi_devices);
241 }
242 
243 /*
244  *	Process a DMI table entry. Right now all we care about are the BIOS
245  *	and machine entries. For 2.5 we should pull the smbus controller info
246  *	out of here.
247  */
248 static void __init dmi_decode(const struct dmi_header *dm)
249 {
250 	switch(dm->type) {
251 	case 0:		/* BIOS Information */
252 		dmi_save_ident(dm, DMI_BIOS_VENDOR, 4);
253 		dmi_save_ident(dm, DMI_BIOS_VERSION, 5);
254 		dmi_save_ident(dm, DMI_BIOS_DATE, 8);
255 		break;
256 	case 1:		/* System Information */
257 		dmi_save_ident(dm, DMI_SYS_VENDOR, 4);
258 		dmi_save_ident(dm, DMI_PRODUCT_NAME, 5);
259 		dmi_save_ident(dm, DMI_PRODUCT_VERSION, 6);
260 		dmi_save_ident(dm, DMI_PRODUCT_SERIAL, 7);
261 		dmi_save_uuid(dm, DMI_PRODUCT_UUID, 8);
262 		break;
263 	case 2:		/* Base Board Information */
264 		dmi_save_ident(dm, DMI_BOARD_VENDOR, 4);
265 		dmi_save_ident(dm, DMI_BOARD_NAME, 5);
266 		dmi_save_ident(dm, DMI_BOARD_VERSION, 6);
267 		dmi_save_ident(dm, DMI_BOARD_SERIAL, 7);
268 		dmi_save_ident(dm, DMI_BOARD_ASSET_TAG, 8);
269 		break;
270 	case 3:		/* Chassis Information */
271 		dmi_save_ident(dm, DMI_CHASSIS_VENDOR, 4);
272 		dmi_save_type(dm, DMI_CHASSIS_TYPE, 5);
273 		dmi_save_ident(dm, DMI_CHASSIS_VERSION, 6);
274 		dmi_save_ident(dm, DMI_CHASSIS_SERIAL, 7);
275 		dmi_save_ident(dm, DMI_CHASSIS_ASSET_TAG, 8);
276 		break;
277 	case 10:	/* Onboard Devices Information */
278 		dmi_save_devices(dm);
279 		break;
280 	case 11:	/* OEM Strings */
281 		dmi_save_oem_strings_devices(dm);
282 		break;
283 	case 38:	/* IPMI Device Information */
284 		dmi_save_ipmi_device(dm);
285 	}
286 }
287 
288 static int __init dmi_present(const char __iomem *p)
289 {
290 	u8 buf[15];
291 
292 	memcpy_fromio(buf, p, 15);
293 	if ((memcmp(buf, "_DMI_", 5) == 0) && dmi_checksum(buf)) {
294 		u16 num = (buf[13] << 8) | buf[12];
295 		u16 len = (buf[7] << 8) | buf[6];
296 		u32 base = (buf[11] << 24) | (buf[10] << 16) |
297 			(buf[9] << 8) | buf[8];
298 
299 		/*
300 		 * DMI version 0.0 means that the real version is taken from
301 		 * the SMBIOS version, which we don't know at this point.
302 		 */
303 		if (buf[14] != 0)
304 			printk(KERN_INFO "DMI %d.%d present.\n",
305 			       buf[14] >> 4, buf[14] & 0xF);
306 		else
307 			printk(KERN_INFO "DMI present.\n");
308 		if (dmi_table(base,len, num, dmi_decode) == 0)
309 			return 0;
310 	}
311 	return 1;
312 }
313 
314 void __init dmi_scan_machine(void)
315 {
316 	char __iomem *p, *q;
317 	int rc;
318 
319 	if (efi_enabled) {
320 		if (efi.smbios == EFI_INVALID_TABLE_ADDR)
321 			goto out;
322 
323 		/* This is called as a core_initcall() because it isn't
324 		 * needed during early boot.  This also means we can
325 		 * iounmap the space when we're done with it.
326 		 */
327 		p = dmi_ioremap(efi.smbios, 32);
328 		if (p == NULL)
329 			goto out;
330 
331 		rc = dmi_present(p + 0x10); /* offset of _DMI_ string */
332 		dmi_iounmap(p, 32);
333 		if (!rc) {
334 			dmi_available = 1;
335 			return;
336 		}
337 	}
338 	else {
339 		/*
340 		 * no iounmap() for that ioremap(); it would be a no-op, but
341 		 * it's so early in setup that sucker gets confused into doing
342 		 * what it shouldn't if we actually call it.
343 		 */
344 		p = dmi_ioremap(0xF0000, 0x10000);
345 		if (p == NULL)
346 			goto out;
347 
348 		for (q = p; q < p + 0x10000; q += 16) {
349 			rc = dmi_present(q);
350 			if (!rc) {
351 				dmi_available = 1;
352 				dmi_iounmap(p, 0x10000);
353 				return;
354 			}
355 		}
356 		dmi_iounmap(p, 0x10000);
357 	}
358  out:	printk(KERN_INFO "DMI not present or invalid.\n");
359 }
360 
361 /**
362  *	dmi_check_system - check system DMI data
363  *	@list: array of dmi_system_id structures to match against
364  *		All non-null elements of the list must match
365  *		their slot's (field index's) data (i.e., each
366  *		list string must be a substring of the specified
367  *		DMI slot's string data) to be considered a
368  *		successful match.
369  *
370  *	Walk the blacklist table running matching functions until someone
371  *	returns non zero or we hit the end. Callback function is called for
372  *	each successful match. Returns the number of matches.
373  */
374 int dmi_check_system(const struct dmi_system_id *list)
375 {
376 	int i, count = 0;
377 	const struct dmi_system_id *d = list;
378 
379 	while (d->ident) {
380 		for (i = 0; i < ARRAY_SIZE(d->matches); i++) {
381 			int s = d->matches[i].slot;
382 			if (s == DMI_NONE)
383 				continue;
384 			if (dmi_ident[s] && strstr(dmi_ident[s], d->matches[i].substr))
385 				continue;
386 			/* No match */
387 			goto fail;
388 		}
389 		count++;
390 		if (d->callback && d->callback(d))
391 			break;
392 fail:		d++;
393 	}
394 
395 	return count;
396 }
397 EXPORT_SYMBOL(dmi_check_system);
398 
399 /**
400  *	dmi_get_system_info - return DMI data value
401  *	@field: data index (see enum dmi_field)
402  *
403  *	Returns one DMI data value, can be used to perform
404  *	complex DMI data checks.
405  */
406 const char *dmi_get_system_info(int field)
407 {
408 	return dmi_ident[field];
409 }
410 EXPORT_SYMBOL(dmi_get_system_info);
411 
412 
413 /**
414  *	dmi_name_in_vendors - Check if string is anywhere in the DMI vendor information.
415  *	@str: 	Case sensitive Name
416  */
417 int dmi_name_in_vendors(const char *str)
418 {
419 	static int fields[] = { DMI_BIOS_VENDOR, DMI_BIOS_VERSION, DMI_SYS_VENDOR,
420 				DMI_PRODUCT_NAME, DMI_PRODUCT_VERSION, DMI_BOARD_VENDOR,
421 				DMI_BOARD_NAME, DMI_BOARD_VERSION, DMI_NONE };
422 	int i;
423 	for (i = 0; fields[i] != DMI_NONE; i++) {
424 		int f = fields[i];
425 		if (dmi_ident[f] && strstr(dmi_ident[f], str))
426 			return 1;
427 	}
428 	return 0;
429 }
430 EXPORT_SYMBOL(dmi_name_in_vendors);
431 
432 /**
433  *	dmi_find_device - find onboard device by type/name
434  *	@type: device type or %DMI_DEV_TYPE_ANY to match all device types
435  *	@name: device name string or %NULL to match all
436  *	@from: previous device found in search, or %NULL for new search.
437  *
438  *	Iterates through the list of known onboard devices. If a device is
439  *	found with a matching @vendor and @device, a pointer to its device
440  *	structure is returned.  Otherwise, %NULL is returned.
441  *	A new search is initiated by passing %NULL as the @from argument.
442  *	If @from is not %NULL, searches continue from next device.
443  */
444 const struct dmi_device * dmi_find_device(int type, const char *name,
445 				    const struct dmi_device *from)
446 {
447 	const struct list_head *head = from ? &from->list : &dmi_devices;
448 	struct list_head *d;
449 
450 	for(d = head->next; d != &dmi_devices; d = d->next) {
451 		const struct dmi_device *dev =
452 			list_entry(d, struct dmi_device, list);
453 
454 		if (((type == DMI_DEV_TYPE_ANY) || (dev->type == type)) &&
455 		    ((name == NULL) || (strcmp(dev->name, name) == 0)))
456 			return dev;
457 	}
458 
459 	return NULL;
460 }
461 EXPORT_SYMBOL(dmi_find_device);
462 
463 /**
464  *	dmi_get_year - Return year of a DMI date
465  *	@field:	data index (like dmi_get_system_info)
466  *
467  *	Returns -1 when the field doesn't exist. 0 when it is broken.
468  */
469 int dmi_get_year(int field)
470 {
471 	int year;
472 	const char *s = dmi_get_system_info(field);
473 
474 	if (!s)
475 		return -1;
476 	if (*s == '\0')
477 		return 0;
478 	s = strrchr(s, '/');
479 	if (!s)
480 		return 0;
481 
482 	s += 1;
483 	year = simple_strtoul(s, NULL, 0);
484 	if (year && year < 100) {	/* 2-digit year */
485 		year += 1900;
486 		if (year < 1996)	/* no dates < spec 1.0 */
487 			year += 100;
488 	}
489 
490 	return year;
491 }
492 
493 /**
494  *	dmi_get_slot - return dmi_ident[slot]
495  *	@slot:	index into dmi_ident[]
496  */
497 char *dmi_get_slot(int slot)
498 {
499 	return(dmi_ident[slot]);
500 }
501