xref: /linux/drivers/firmware/dmi_scan.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
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 
127 		list_add(&dev->list, &dmi_devices);
128 	}
129 }
130 
131 static void __init dmi_save_ipmi_device(struct dmi_header *dm)
132 {
133 	struct dmi_device *dev;
134 	void * data;
135 
136 	data = dmi_alloc(dm->length);
137 	if (data == NULL) {
138 		printk(KERN_ERR "dmi_save_ipmi_device: out of memory.\n");
139 		return;
140 	}
141 
142 	memcpy(data, dm, dm->length);
143 
144 	dev = dmi_alloc(sizeof(*dev));
145 	if (!dev) {
146 		printk(KERN_ERR "dmi_save_ipmi_device: out of memory.\n");
147 		return;
148 	}
149 
150 	dev->type = DMI_DEV_TYPE_IPMI;
151 	dev->name = "IPMI controller";
152 	dev->device_data = data;
153 
154 	list_add(&dev->list, &dmi_devices);
155 }
156 
157 /*
158  *	Process a DMI table entry. Right now all we care about are the BIOS
159  *	and machine entries. For 2.5 we should pull the smbus controller info
160  *	out of here.
161  */
162 static void __init dmi_decode(struct dmi_header *dm)
163 {
164 	switch(dm->type) {
165 	case 0:		/* BIOS Information */
166 		dmi_save_ident(dm, DMI_BIOS_VENDOR, 4);
167 		dmi_save_ident(dm, DMI_BIOS_VERSION, 5);
168 		dmi_save_ident(dm, DMI_BIOS_DATE, 8);
169 		break;
170 	case 1:		/* System Information */
171 		dmi_save_ident(dm, DMI_SYS_VENDOR, 4);
172 		dmi_save_ident(dm, DMI_PRODUCT_NAME, 5);
173 		dmi_save_ident(dm, DMI_PRODUCT_VERSION, 6);
174 		dmi_save_ident(dm, DMI_PRODUCT_SERIAL, 7);
175 		break;
176 	case 2:		/* Base Board Information */
177 		dmi_save_ident(dm, DMI_BOARD_VENDOR, 4);
178 		dmi_save_ident(dm, DMI_BOARD_NAME, 5);
179 		dmi_save_ident(dm, DMI_BOARD_VERSION, 6);
180 		break;
181 	case 10:	/* Onboard Devices Information */
182 		dmi_save_devices(dm);
183 		break;
184 	case 38:	/* IPMI Device Information */
185 		dmi_save_ipmi_device(dm);
186 	}
187 }
188 
189 static int __init dmi_present(char __iomem *p)
190 {
191 	u8 buf[15];
192 	memcpy_fromio(buf, p, 15);
193 	if ((memcmp(buf, "_DMI_", 5) == 0) && dmi_checksum(buf)) {
194 		u16 num = (buf[13] << 8) | buf[12];
195 		u16 len = (buf[7] << 8) | buf[6];
196 		u32 base = (buf[11] << 24) | (buf[10] << 16) |
197 			(buf[9] << 8) | buf[8];
198 
199 		/*
200 		 * DMI version 0.0 means that the real version is taken from
201 		 * the SMBIOS version, which we don't know at this point.
202 		 */
203 		if (buf[14] != 0)
204 			printk(KERN_INFO "DMI %d.%d present.\n",
205 			       buf[14] >> 4, buf[14] & 0xF);
206 		else
207 			printk(KERN_INFO "DMI present.\n");
208 		if (dmi_table(base,len, num, dmi_decode) == 0)
209 			return 0;
210 	}
211 	return 1;
212 }
213 
214 void __init dmi_scan_machine(void)
215 {
216 	char __iomem *p, *q;
217 	int rc;
218 
219 	if (efi_enabled) {
220 		if (efi.smbios == EFI_INVALID_TABLE_ADDR)
221 			goto out;
222 
223                /* This is called as a core_initcall() because it isn't
224                 * needed during early boot.  This also means we can
225                 * iounmap the space when we're done with it.
226 		*/
227 		p = dmi_ioremap(efi.smbios, 32);
228 		if (p == NULL)
229 			goto out;
230 
231 		rc = dmi_present(p + 0x10); /* offset of _DMI_ string */
232 		dmi_iounmap(p, 32);
233 		if (!rc)
234 			return;
235 	}
236 	else {
237 		/*
238 		 * no iounmap() for that ioremap(); it would be a no-op, but
239 		 * it's so early in setup that sucker gets confused into doing
240 		 * what it shouldn't if we actually call it.
241 		 */
242 		p = dmi_ioremap(0xF0000, 0x10000);
243 		if (p == NULL)
244 			goto out;
245 
246 		for (q = p; q < p + 0x10000; q += 16) {
247 			rc = dmi_present(q);
248 			if (!rc)
249 				return;
250 		}
251 	}
252  out:	printk(KERN_INFO "DMI not present or invalid.\n");
253 }
254 
255 /**
256  *	dmi_check_system - check system DMI data
257  *	@list: array of dmi_system_id structures to match against
258  *
259  *	Walk the blacklist table running matching functions until someone
260  *	returns non zero or we hit the end. Callback function is called for
261  *	each successfull match. Returns the number of matches.
262  */
263 int dmi_check_system(struct dmi_system_id *list)
264 {
265 	int i, count = 0;
266 	struct dmi_system_id *d = list;
267 
268 	while (d->ident) {
269 		for (i = 0; i < ARRAY_SIZE(d->matches); i++) {
270 			int s = d->matches[i].slot;
271 			if (s == DMI_NONE)
272 				continue;
273 			if (dmi_ident[s] && strstr(dmi_ident[s], d->matches[i].substr))
274 				continue;
275 			/* No match */
276 			goto fail;
277 		}
278 		count++;
279 		if (d->callback && d->callback(d))
280 			break;
281 fail:		d++;
282 	}
283 
284 	return count;
285 }
286 EXPORT_SYMBOL(dmi_check_system);
287 
288 /**
289  *	dmi_get_system_info - return DMI data value
290  *	@field: data index (see enum dmi_filed)
291  *
292  *	Returns one DMI data value, can be used to perform
293  *	complex DMI data checks.
294  */
295 char *dmi_get_system_info(int field)
296 {
297 	return dmi_ident[field];
298 }
299 EXPORT_SYMBOL(dmi_get_system_info);
300 
301 /**
302  *	dmi_find_device - find onboard device by type/name
303  *	@type: device type or %DMI_DEV_TYPE_ANY to match all device types
304  *	@desc: device name string or %NULL to match all
305  *	@from: previous device found in search, or %NULL for new search.
306  *
307  *	Iterates through the list of known onboard devices. If a device is
308  *	found with a matching @vendor and @device, a pointer to its device
309  *	structure is returned.  Otherwise, %NULL is returned.
310  *	A new search is initiated by passing %NULL to the @from argument.
311  *	If @from is not %NULL, searches continue from next device.
312  */
313 struct dmi_device * dmi_find_device(int type, const char *name,
314 				    struct dmi_device *from)
315 {
316 	struct list_head *d, *head = from ? &from->list : &dmi_devices;
317 
318 	for(d = head->next; d != &dmi_devices; d = d->next) {
319 		struct dmi_device *dev = list_entry(d, struct dmi_device, list);
320 
321 		if (((type == DMI_DEV_TYPE_ANY) || (dev->type == type)) &&
322 		    ((name == NULL) || (strcmp(dev->name, name) == 0)))
323 			return dev;
324 	}
325 
326 	return NULL;
327 }
328 EXPORT_SYMBOL(dmi_find_device);
329 
330 /**
331  *	dmi_get_year - Return year of a DMI date
332  *	@field:	data index (like dmi_get_system_info)
333  *
334  *	Returns -1 when the field doesn't exist. 0 when it is broken.
335  */
336 int dmi_get_year(int field)
337 {
338 	int year;
339 	char *s = dmi_get_system_info(field);
340 
341 	if (!s)
342 		return -1;
343 	if (*s == '\0')
344 		return 0;
345 	s = strrchr(s, '/');
346 	if (!s)
347 		return 0;
348 
349 	s += 1;
350 	year = simple_strtoul(s, NULL, 0);
351 	if (year && year < 100) {	/* 2-digit year */
352 		year += 1900;
353 		if (year < 1996)	/* no dates < spec 1.0 */
354 			year += 100;
355 	}
356 
357 	return year;
358 }
359