xref: /openbmc/linux/drivers/firmware/dmi_scan.c (revision 64c70b1c)
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 * __init dmi_string(struct dmi_header *dm, u8 s)
12 {
13 	u8 *bp = ((u8 *) dm) + dm->length;
14 	char *str = "";
15 
16 	if (s) {
17 		s--;
18 		while (s > 0 && *bp) {
19 			bp += strlen(bp) + 1;
20 			s--;
21 		}
22 
23 		if (*bp != 0) {
24 			str = dmi_alloc(strlen(bp) + 1);
25 			if (str != NULL)
26 				strcpy(str, bp);
27 			else
28 				printk(KERN_ERR "dmi_string: out of memory.\n");
29 		}
30 	}
31 
32 	return str;
33 }
34 
35 /*
36  *	We have to be cautious here. We have seen BIOSes with DMI pointers
37  *	pointing to completely the wrong place for example
38  */
39 static int __init dmi_table(u32 base, int len, int num,
40 			    void (*decode)(struct dmi_header *))
41 {
42 	u8 *buf, *data;
43 	int i = 0;
44 
45 	buf = dmi_ioremap(base, len);
46 	if (buf == NULL)
47 		return -1;
48 
49 	data = buf;
50 
51 	/*
52 	 *	Stop when we see all the items the table claimed to have
53 	 *	OR we run off the end of the table (also happens)
54 	 */
55 	while ((i < num) && (data - buf + sizeof(struct dmi_header)) <= len) {
56 		struct dmi_header *dm = (struct dmi_header *)data;
57 		/*
58 		 *  We want to know the total length (formated area and strings)
59 		 *  before decoding to make sure we won't run off the table in
60 		 *  dmi_decode or dmi_string
61 		 */
62 		data += dm->length;
63 		while ((data - buf < len - 1) && (data[0] || data[1]))
64 			data++;
65 		if (data - buf < len - 1)
66 			decode(dm);
67 		data += 2;
68 		i++;
69 	}
70 	dmi_iounmap(buf, len);
71 	return 0;
72 }
73 
74 static int __init dmi_checksum(u8 *buf)
75 {
76 	u8 sum = 0;
77 	int a;
78 
79 	for (a = 0; a < 15; a++)
80 		sum += buf[a];
81 
82 	return sum == 0;
83 }
84 
85 static char *dmi_ident[DMI_STRING_MAX];
86 static LIST_HEAD(dmi_devices);
87 
88 /*
89  *	Save a DMI string
90  */
91 static void __init dmi_save_ident(struct dmi_header *dm, int slot, int string)
92 {
93 	char *p, *d = (char*) dm;
94 
95 	if (dmi_ident[slot])
96 		return;
97 
98 	p = dmi_string(dm, d[string]);
99 	if (p == NULL)
100 		return;
101 
102 	dmi_ident[slot] = p;
103 }
104 
105 static void __init dmi_save_devices(struct dmi_header *dm)
106 {
107 	int i, count = (dm->length - sizeof(struct dmi_header)) / 2;
108 	struct dmi_device *dev;
109 
110 	for (i = 0; i < count; i++) {
111 		char *d = (char *)(dm + 1) + (i * 2);
112 
113 		/* Skip disabled device */
114 		if ((*d & 0x80) == 0)
115 			continue;
116 
117 		dev = dmi_alloc(sizeof(*dev));
118 		if (!dev) {
119 			printk(KERN_ERR "dmi_save_devices: out of memory.\n");
120 			break;
121 		}
122 
123 		dev->type = *d++ & 0x7f;
124 		dev->name = dmi_string(dm, *d);
125 		dev->device_data = NULL;
126 		list_add(&dev->list, &dmi_devices);
127 	}
128 }
129 
130 static void __init dmi_save_oem_strings_devices(struct dmi_header *dm)
131 {
132 	int i, count = *(u8 *)(dm + 1);
133 	struct dmi_device *dev;
134 
135 	for (i = 1; i <= count; i++) {
136 		dev = dmi_alloc(sizeof(*dev));
137 		if (!dev) {
138 			printk(KERN_ERR
139 			   "dmi_save_oem_strings_devices: out of memory.\n");
140 			break;
141 		}
142 
143 		dev->type = DMI_DEV_TYPE_OEM_STRING;
144 		dev->name = dmi_string(dm, i);
145 		dev->device_data = NULL;
146 
147 		list_add(&dev->list, &dmi_devices);
148 	}
149 }
150 
151 static void __init dmi_save_ipmi_device(struct dmi_header *dm)
152 {
153 	struct dmi_device *dev;
154 	void * data;
155 
156 	data = dmi_alloc(dm->length);
157 	if (data == NULL) {
158 		printk(KERN_ERR "dmi_save_ipmi_device: out of memory.\n");
159 		return;
160 	}
161 
162 	memcpy(data, dm, dm->length);
163 
164 	dev = dmi_alloc(sizeof(*dev));
165 	if (!dev) {
166 		printk(KERN_ERR "dmi_save_ipmi_device: out of memory.\n");
167 		return;
168 	}
169 
170 	dev->type = DMI_DEV_TYPE_IPMI;
171 	dev->name = "IPMI controller";
172 	dev->device_data = data;
173 
174 	list_add(&dev->list, &dmi_devices);
175 }
176 
177 /*
178  *	Process a DMI table entry. Right now all we care about are the BIOS
179  *	and machine entries. For 2.5 we should pull the smbus controller info
180  *	out of here.
181  */
182 static void __init dmi_decode(struct dmi_header *dm)
183 {
184 	switch(dm->type) {
185 	case 0:		/* BIOS Information */
186 		dmi_save_ident(dm, DMI_BIOS_VENDOR, 4);
187 		dmi_save_ident(dm, DMI_BIOS_VERSION, 5);
188 		dmi_save_ident(dm, DMI_BIOS_DATE, 8);
189 		break;
190 	case 1:		/* System Information */
191 		dmi_save_ident(dm, DMI_SYS_VENDOR, 4);
192 		dmi_save_ident(dm, DMI_PRODUCT_NAME, 5);
193 		dmi_save_ident(dm, DMI_PRODUCT_VERSION, 6);
194 		dmi_save_ident(dm, DMI_PRODUCT_SERIAL, 7);
195 		break;
196 	case 2:		/* Base Board Information */
197 		dmi_save_ident(dm, DMI_BOARD_VENDOR, 4);
198 		dmi_save_ident(dm, DMI_BOARD_NAME, 5);
199 		dmi_save_ident(dm, DMI_BOARD_VERSION, 6);
200 		break;
201 	case 10:	/* Onboard Devices Information */
202 		dmi_save_devices(dm);
203 		break;
204 	case 11:	/* OEM Strings */
205 		dmi_save_oem_strings_devices(dm);
206 		break;
207 	case 38:	/* IPMI Device Information */
208 		dmi_save_ipmi_device(dm);
209 	}
210 }
211 
212 static int __init dmi_present(char __iomem *p)
213 {
214 	u8 buf[15];
215 	memcpy_fromio(buf, p, 15);
216 	if ((memcmp(buf, "_DMI_", 5) == 0) && dmi_checksum(buf)) {
217 		u16 num = (buf[13] << 8) | buf[12];
218 		u16 len = (buf[7] << 8) | buf[6];
219 		u32 base = (buf[11] << 24) | (buf[10] << 16) |
220 			(buf[9] << 8) | buf[8];
221 
222 		/*
223 		 * DMI version 0.0 means that the real version is taken from
224 		 * the SMBIOS version, which we don't know at this point.
225 		 */
226 		if (buf[14] != 0)
227 			printk(KERN_INFO "DMI %d.%d present.\n",
228 			       buf[14] >> 4, buf[14] & 0xF);
229 		else
230 			printk(KERN_INFO "DMI present.\n");
231 		if (dmi_table(base,len, num, dmi_decode) == 0)
232 			return 0;
233 	}
234 	return 1;
235 }
236 
237 void __init dmi_scan_machine(void)
238 {
239 	char __iomem *p, *q;
240 	int rc;
241 
242 	if (efi_enabled) {
243 		if (efi.smbios == EFI_INVALID_TABLE_ADDR)
244 			goto out;
245 
246                /* This is called as a core_initcall() because it isn't
247                 * needed during early boot.  This also means we can
248                 * iounmap the space when we're done with it.
249 		*/
250 		p = dmi_ioremap(efi.smbios, 32);
251 		if (p == NULL)
252 			goto out;
253 
254 		rc = dmi_present(p + 0x10); /* offset of _DMI_ string */
255 		dmi_iounmap(p, 32);
256 		if (!rc)
257 			return;
258 	}
259 	else {
260 		/*
261 		 * no iounmap() for that ioremap(); it would be a no-op, but
262 		 * it's so early in setup that sucker gets confused into doing
263 		 * what it shouldn't if we actually call it.
264 		 */
265 		p = dmi_ioremap(0xF0000, 0x10000);
266 		if (p == NULL)
267 			goto out;
268 
269 		for (q = p; q < p + 0x10000; q += 16) {
270 			rc = dmi_present(q);
271 			if (!rc)
272 				return;
273 		}
274 	}
275  out:	printk(KERN_INFO "DMI not present or invalid.\n");
276 }
277 
278 /**
279  *	dmi_check_system - check system DMI data
280  *	@list: array of dmi_system_id structures to match against
281  *		All non-null elements of the list must match
282  *		their slot's (field index's) data (i.e., each
283  *		list string must be a substring of the specified
284  *		DMI slot's string data) to be considered a
285  *		successful match.
286  *
287  *	Walk the blacklist table running matching functions until someone
288  *	returns non zero or we hit the end. Callback function is called for
289  *	each successful match. Returns the number of matches.
290  */
291 int dmi_check_system(struct dmi_system_id *list)
292 {
293 	int i, count = 0;
294 	struct dmi_system_id *d = list;
295 
296 	while (d->ident) {
297 		for (i = 0; i < ARRAY_SIZE(d->matches); i++) {
298 			int s = d->matches[i].slot;
299 			if (s == DMI_NONE)
300 				continue;
301 			if (dmi_ident[s] && strstr(dmi_ident[s], d->matches[i].substr))
302 				continue;
303 			/* No match */
304 			goto fail;
305 		}
306 		count++;
307 		if (d->callback && d->callback(d))
308 			break;
309 fail:		d++;
310 	}
311 
312 	return count;
313 }
314 EXPORT_SYMBOL(dmi_check_system);
315 
316 /**
317  *	dmi_get_system_info - return DMI data value
318  *	@field: data index (see enum dmi_field)
319  *
320  *	Returns one DMI data value, can be used to perform
321  *	complex DMI data checks.
322  */
323 char *dmi_get_system_info(int field)
324 {
325 	return dmi_ident[field];
326 }
327 EXPORT_SYMBOL(dmi_get_system_info);
328 
329 
330 /**
331  *	dmi_name_in_vendors - Check if string is anywhere in the DMI vendor information.
332  *	@str: 	Case sensitive Name
333  */
334 int dmi_name_in_vendors(char *str)
335 {
336 	static int fields[] = { DMI_BIOS_VENDOR, DMI_BIOS_VERSION, DMI_SYS_VENDOR,
337 				DMI_PRODUCT_NAME, DMI_PRODUCT_VERSION, DMI_BOARD_VENDOR,
338 				DMI_BOARD_NAME, DMI_BOARD_VERSION, DMI_NONE };
339 	int i;
340 	for (i = 0; fields[i] != DMI_NONE; i++) {
341 		int f = fields[i];
342 		if (dmi_ident[f] && strstr(dmi_ident[f], str))
343 			return 1;
344 	}
345 	return 0;
346 }
347 EXPORT_SYMBOL(dmi_name_in_vendors);
348 
349 /**
350  *	dmi_find_device - find onboard device by type/name
351  *	@type: device type or %DMI_DEV_TYPE_ANY to match all device types
352  *	@name: device name string or %NULL to match all
353  *	@from: previous device found in search, or %NULL for new search.
354  *
355  *	Iterates through the list of known onboard devices. If a device is
356  *	found with a matching @vendor and @device, a pointer to its device
357  *	structure is returned.  Otherwise, %NULL is returned.
358  *	A new search is initiated by passing %NULL as the @from argument.
359  *	If @from is not %NULL, searches continue from next device.
360  */
361 struct dmi_device * dmi_find_device(int type, const char *name,
362 				    struct dmi_device *from)
363 {
364 	struct list_head *d, *head = from ? &from->list : &dmi_devices;
365 
366 	for(d = head->next; d != &dmi_devices; d = d->next) {
367 		struct dmi_device *dev = list_entry(d, struct dmi_device, list);
368 
369 		if (((type == DMI_DEV_TYPE_ANY) || (dev->type == type)) &&
370 		    ((name == NULL) || (strcmp(dev->name, name) == 0)))
371 			return dev;
372 	}
373 
374 	return NULL;
375 }
376 EXPORT_SYMBOL(dmi_find_device);
377 
378 /**
379  *	dmi_get_year - Return year of a DMI date
380  *	@field:	data index (like dmi_get_system_info)
381  *
382  *	Returns -1 when the field doesn't exist. 0 when it is broken.
383  */
384 int dmi_get_year(int field)
385 {
386 	int year;
387 	char *s = dmi_get_system_info(field);
388 
389 	if (!s)
390 		return -1;
391 	if (*s == '\0')
392 		return 0;
393 	s = strrchr(s, '/');
394 	if (!s)
395 		return 0;
396 
397 	s += 1;
398 	year = simple_strtoul(s, NULL, 0);
399 	if (year && year < 100) {	/* 2-digit year */
400 		year += 1900;
401 		if (year < 1996)	/* no dates < spec 1.0 */
402 			year += 100;
403 	}
404 
405 	return year;
406 }
407