1 /* $NetBSD: smbios.c,v 1.4 2021/09/16 22:19:10 andvar Exp $ */
2
3 /*
4 * Copyright (c) 1999 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9 * NASA Ames Research Center.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 /*
34 * Copyright (c) 1999, by UCHIYAMA Yasushi
35 * All rights reserved.
36 *
37 * Redistribution and use in source and binary forms, with or without
38 * modification, are permitted provided that the following conditions
39 * are met:
40 * 1. Redistributions of source code must retain the above copyright
41 * notice, this list of conditions and the following disclaimer.
42 * 2. The name of the developer may NOT be used to endorse or promote products
43 * derived from this software without specific prior written permission.
44 *
45 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
46 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
47 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
48 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
49 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
50 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
51 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
52 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
53 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
54 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
55 * SUCH DAMAGE.
56 */
57
58 /*
59 * Copyright (c) 1997-2001 Michael Shalayeff
60 * All rights reserved.
61 *
62 * Redistribution and use in source and binary forms, with or without
63 * modification, are permitted provided that the following conditions
64 * are met:
65 * 1. Redistributions of source code must retain the above copyright
66 * notice, this list of conditions and the following disclaimer.
67 * 2. Redistributions in binary form must reproduce the above copyright
68 * notice, this list of conditions and the following disclaimer in the
69 * documentation and/or other materials provided with the distribution.
70 *
71 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
72 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
73 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
74 * IN NO EVENT SHALL THE AUTHOR OR HIS RELATIVES BE LIABLE FOR ANY DIRECT,
75 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
76 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
77 * SERVICES; LOSS OF MIND, USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
78 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
79 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
80 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
81 * THE POSSIBILITY OF SUCH DAMAGE.
82 */
83
84 /*
85 * Basic interface to System Management BIOS (SMBIOS) tables.
86 */
87
88 #include <sys/cdefs.h>
89 __KERNEL_RCSID(0, "$NetBSD: smbios.c,v 1.4 2021/09/16 22:19:10 andvar Exp $");
90
91 #include <sys/param.h>
92 #include <sys/conf.h>
93 #include <sys/systm.h>
94 #include <sys/device.h>
95
96 #include <uvm/uvm_extern.h>
97
98 #include <dev/smbiosvar.h>
99
100 #define SMBIOS_MAKESIG(a, b, c, d) \
101 ((a) | ((b) << 8) | ((c) << 16) | ((d) << 24))
102
103 struct smbios_entry smbios_entry;
104
105 static dev_type_read(smbios_read);
106
107 const struct cdevsw smbios_cdevsw = {
108 .d_open = nullopen,
109 .d_close = nullclose,
110 .d_read = smbios_read,
111 .d_write = nowrite,
112 .d_ioctl = noioctl,
113 .d_stop = nostop,
114 .d_tty = notty,
115 .d_poll = nopoll,
116 .d_mmap = nommap,
117 .d_kqfilter = nokqfilter,
118 .d_discard = nodiscard,
119 .d_flag = D_OTHER | D_MPSAFE,
120 };
121
122 static void *
smbios_map_memory(paddr_t pa,size_t size)123 smbios_map_memory(paddr_t pa, size_t size)
124 {
125 paddr_t spa, epa, curpa;
126 vaddr_t va, curva;
127
128 spa = trunc_page(pa);
129 epa = round_page(pa + size);
130
131 va = uvm_km_alloc(kernel_map, epa - spa, 0, UVM_KMF_VAONLY);
132 if (va == 0) {
133 return NULL;
134 }
135
136 for (curpa = spa, curva = va; curpa < epa; curpa += PAGE_SIZE, curva += PAGE_SIZE) {
137 pmap_kenter_pa(curva, curpa, VM_PROT_READ, PMAP_WRITE_BACK);
138 }
139 pmap_update(pmap_kernel());
140
141 return (void *)(uintptr_t)(va + (pa - spa));
142 }
143
144 static void
smbios_unmap_memory(void * va,size_t size)145 smbios_unmap_memory(void *va, size_t size)
146 {
147 vaddr_t ova;
148 vsize_t osz;
149
150 ova = trunc_page((vaddr_t)va);
151 osz = round_page((vaddr_t)va + size) - ova;
152
153 pmap_kremove(ova, osz);
154 pmap_update(pmap_kernel());
155 uvm_km_free(kernel_map, ova, osz, UVM_KMF_VAONLY);
156 }
157
158 /*
159 * smbios_read --
160 *
161 * Read data from an SMBIOS table that resides in physical memory.
162 */
163 static int
smbios_read(dev_t dev,struct uio * uio,int flag)164 smbios_read(dev_t dev, struct uio *uio, int flag)
165 {
166 paddr_t pa;
167 uint8_t *data;
168 size_t len;
169 int error;
170
171 if (smbios_entry.addr == NULL) {
172 return EIO;
173 }
174 if (uio->uio_rw != UIO_READ) {
175 return EPERM;
176 }
177
178 pa = uio->uio_offset;
179 if (pa == smbios_entry.hdrphys) {
180 /* SMBIOS header */
181 len = uimin(0x20, uio->uio_resid);
182
183 } else {
184 /* Table data */
185 if (pa < smbios_entry.tabphys ||
186 pa >= smbios_entry.tabphys + smbios_entry.len) {
187 return EFAULT;
188 }
189 len = uimin(smbios_entry.len - (pa - smbios_entry.tabphys),
190 uio->uio_resid);
191 }
192
193 data = smbios_map_memory(pa, len);
194 if (data == NULL) {
195 return ENOMEM;
196 }
197 error = uiomove(data, len, uio);
198 smbios_unmap_memory(data, len);
199
200 return error;
201 }
202
203 int
smbios2_check_header(const uint8_t * p)204 smbios2_check_header(const uint8_t *p)
205 {
206 const struct smbhdr *sh = (const struct smbhdr *)p;
207 uint8_t chksum;
208 int i;
209
210 if (sh->sig != SMBIOS_MAKESIG('_', 'S', 'M', '_'))
211 return 0;
212 i = sh->len;
213 for (chksum = 0; i--; )
214 chksum += p[i];
215 if (chksum != 0)
216 return 0;
217 p += 0x10;
218 if (p[0] != '_' || p[1] != 'D' || p[2] != 'M' ||
219 p[3] != 'I' || p[4] != '_')
220 return 0;
221 for (chksum = 0, i = 0xf; i--; )
222 chksum += p[i];
223 if (chksum != 0)
224 return 0;
225
226 return 1;
227 }
228
229 int
smbios3_check_header(const uint8_t * p)230 smbios3_check_header(const uint8_t *p)
231 {
232 const struct smb3hdr *sh = (const struct smb3hdr *)p;
233 uint8_t chksum;
234 int i;
235
236 if (p[0] != '_' || p[1] != 'S' || p[2] != 'M' ||
237 p[3] != '3' || p[4] != '_')
238 return 0;
239 i = sh->len;
240 for (chksum = 0; i--; )
241 chksum += p[i];
242 if (chksum != 0)
243 return 0;
244 if (sh->eprev != SMBIOS3_EPREV_3_0)
245 return 0;
246
247 return 1;
248 }
249
250 /*
251 * smbios_find_table() takes a caller supplied smbios struct type and
252 * a pointer to a handle (struct smbtable) returning one if the structure
253 * is successfully located and zero otherwise. Callers should take care
254 * to initilize the cookie field of the smbtable structure to zero before
255 * the first invocation of this function.
256 * Multiple tables of the same type can be located by repeadtly calling
257 * smbios_find_table with the same arguments.
258 */
259 int
smbios_find_table(uint8_t type,struct smbtable * st)260 smbios_find_table(uint8_t type, struct smbtable *st)
261 {
262 uint8_t *va, *end;
263 struct smbtblhdr *hdr;
264 int ret = 0, tcount = 1;
265
266 if (smbios_entry.addr == NULL) {
267 return 0;
268 }
269
270 va = smbios_entry.addr;
271 end = va + smbios_entry.len;
272
273 /*
274 * The cookie field of the smtable structure is used to locate
275 * multiple instances of a table of an arbitrary type. Following the
276 * successful location of a table, the type is encoded as bits 0:7 of
277 * the cookie value, the offset in terms of the number of structures
278 * preceding that referenced by the handle is encoded in bits 15:31.
279 */
280 if ((st->cookie & 0xfff) == type && st->cookie >> 16) {
281 if ((uint8_t *)st->hdr >= va && (uint8_t *)st->hdr < end) {
282 hdr = st->hdr;
283 if (hdr->type == type) {
284 va = (uint8_t *)hdr + hdr->size;
285 for (; va + 1 < end; va++)
286 if (*va == 0 && *(va + 1) == 0)
287 break;
288 va+= 2;
289 tcount = st->cookie >> 16;
290 }
291 }
292 }
293 for (; va + sizeof(struct smbtblhdr) < end && tcount <=
294 smbios_entry.count; tcount++) {
295 hdr = (struct smbtblhdr *)va;
296 if (hdr->type == type) {
297 ret = 1;
298 st->hdr = hdr;
299 st->tblhdr = va + sizeof(struct smbtblhdr);
300 st->cookie = (tcount + 1) << 16 | type;
301 break;
302 }
303 if (hdr->type == SMBIOS_TYPE_EOT)
304 break;
305 va+= hdr->size;
306 for (; va + 1 < end; va++)
307 if (*va == 0 && *(va + 1) == 0)
308 break;
309 va+=2;
310 }
311
312 return ret;
313 }
314
315 char *
smbios_get_string(struct smbtable * st,uint8_t indx,char * dest,size_t len)316 smbios_get_string(struct smbtable *st, uint8_t indx, char *dest, size_t len)
317 {
318 uint8_t *va, *end;
319 char *ret = NULL;
320 int i;
321
322 KASSERT(smbios_entry.addr != NULL);
323
324 va = (uint8_t *)st->hdr + st->hdr->size;
325 end = smbios_entry.addr + smbios_entry.len;
326 for (i = 1; va < end && i < indx && *va; i++)
327 while (*va++)
328 ;
329 if (i == indx) {
330 if (va + len < end) {
331 ret = dest;
332 memcpy(ret, va, len);
333 ret[len - 1] = '\0';
334 }
335 }
336
337 return ret;
338 }
339