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6ae6996a FT |
1 | /* sfi_core.c Simple Firmware Interface - core internals */ |
2 | ||
3 | /* | |
4 | ||
5 | This file is provided under a dual BSD/GPLv2 license. When using or | |
6 | redistributing this file, you may do so under either license. | |
7 | ||
8 | GPL LICENSE SUMMARY | |
9 | ||
10 | Copyright(c) 2009 Intel Corporation. All rights reserved. | |
11 | ||
12 | This program is free software; you can redistribute it and/or modify | |
13 | it under the terms of version 2 of the GNU General Public License as | |
14 | published by the Free Software Foundation. | |
15 | ||
16 | This program is distributed in the hope that it will be useful, but | |
17 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
18 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
19 | General Public License for more details. | |
20 | ||
21 | You should have received a copy of the GNU General Public License | |
22 | along with this program; if not, write to the Free Software | |
23 | Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. | |
24 | The full GNU General Public License is included in this distribution | |
25 | in the file called LICENSE.GPL. | |
26 | ||
27 | BSD LICENSE | |
28 | ||
29 | Copyright(c) 2009 Intel Corporation. All rights reserved. | |
30 | ||
31 | Redistribution and use in source and binary forms, with or without | |
32 | modification, are permitted provided that the following conditions | |
33 | are met: | |
34 | ||
35 | * Redistributions of source code must retain the above copyright | |
36 | notice, this list of conditions and the following disclaimer. | |
37 | * Redistributions in binary form must reproduce the above copyright | |
38 | notice, this list of conditions and the following disclaimer in | |
39 | the documentation and/or other materials provided with the | |
40 | distribution. | |
41 | * Neither the name of Intel Corporation nor the names of its | |
42 | contributors may be used to endorse or promote products derived | |
43 | from this software without specific prior written permission. | |
44 | ||
45 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
46 | "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
47 | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | |
48 | A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
49 | OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
50 | SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |
51 | LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
52 | DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
53 | THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
54 | (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
55 | OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
56 | ||
57 | */ | |
58 | ||
59 | #define KMSG_COMPONENT "SFI" | |
60 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt | |
61 | ||
62 | #include <linux/bootmem.h> | |
63 | #include <linux/kernel.h> | |
64 | #include <linux/module.h> | |
6ae6996a FT |
65 | #include <linux/errno.h> |
66 | #include <linux/types.h> | |
67 | #include <linux/acpi.h> | |
68 | #include <linux/init.h> | |
6ae6996a | 69 | #include <linux/sfi.h> |
dce80a56 | 70 | #include <linux/slab.h> |
693bf0aa | 71 | #include <linux/io.h> |
6ae6996a FT |
72 | |
73 | #include "sfi_core.h" | |
74 | ||
75 | #define ON_SAME_PAGE(addr1, addr2) \ | |
76 | (((unsigned long)(addr1) & PAGE_MASK) == \ | |
77 | ((unsigned long)(addr2) & PAGE_MASK)) | |
78 | #define TABLE_ON_PAGE(page, table, size) (ON_SAME_PAGE(page, table) && \ | |
79 | ON_SAME_PAGE(page, table + size)) | |
80 | ||
81 | int sfi_disabled __read_mostly; | |
82 | EXPORT_SYMBOL(sfi_disabled); | |
83 | ||
84 | static u64 syst_pa __read_mostly; | |
85 | static struct sfi_table_simple *syst_va __read_mostly; | |
86 | ||
87 | /* | |
88 | * FW creates and saves the SFI tables in memory. When these tables get | |
89 | * used, they may need to be mapped to virtual address space, and the mapping | |
f7750a79 | 90 | * can happen before or after the memremap() is ready, so a flag is needed |
6ae6996a FT |
91 | * to indicating this |
92 | */ | |
f7750a79 | 93 | static u32 sfi_use_memremap __read_mostly; |
6ae6996a | 94 | |
01674da6 | 95 | /* |
f7750a79 | 96 | * sfi_un/map_memory calls early_memremap/memunmap which is a __init function |
01674da6 RM |
97 | * and introduces section mismatch. So use __ref to make it calm. |
98 | */ | |
99 | static void __iomem * __ref sfi_map_memory(u64 phys, u32 size) | |
6ae6996a FT |
100 | { |
101 | if (!phys || !size) | |
102 | return NULL; | |
103 | ||
f7750a79 TL |
104 | if (sfi_use_memremap) |
105 | return memremap(phys, size, MEMREMAP_WB); | |
6ae6996a | 106 | else |
f7750a79 | 107 | return early_memremap(phys, size); |
6ae6996a FT |
108 | } |
109 | ||
01674da6 | 110 | static void __ref sfi_unmap_memory(void __iomem *virt, u32 size) |
6ae6996a FT |
111 | { |
112 | if (!virt || !size) | |
113 | return; | |
114 | ||
f7750a79 TL |
115 | if (sfi_use_memremap) |
116 | memunmap(virt); | |
6ae6996a | 117 | else |
f7750a79 | 118 | early_memunmap(virt, size); |
6ae6996a FT |
119 | } |
120 | ||
121 | static void sfi_print_table_header(unsigned long long pa, | |
122 | struct sfi_table_header *header) | |
123 | { | |
124 | pr_info("%4.4s %llX, %04X (v%d %6.6s %8.8s)\n", | |
125 | header->sig, pa, | |
126 | header->len, header->rev, header->oem_id, | |
127 | header->oem_table_id); | |
128 | } | |
129 | ||
130 | /* | |
131 | * sfi_verify_table() | |
132 | * Sanity check table lengh, calculate checksum | |
133 | */ | |
011a606d | 134 | static int sfi_verify_table(struct sfi_table_header *table) |
6ae6996a FT |
135 | { |
136 | ||
137 | u8 checksum = 0; | |
138 | u8 *puchar = (u8 *)table; | |
139 | u32 length = table->len; | |
140 | ||
141 | /* Sanity check table length against arbitrary 1MB limit */ | |
142 | if (length > 0x100000) { | |
143 | pr_err("Invalid table length 0x%x\n", length); | |
144 | return -1; | |
145 | } | |
146 | ||
147 | while (length--) | |
148 | checksum += *puchar++; | |
149 | ||
150 | if (checksum) { | |
151 | pr_err("Checksum %2.2X should be %2.2X\n", | |
152 | table->csum, table->csum - checksum); | |
153 | return -1; | |
154 | } | |
155 | return 0; | |
156 | } | |
157 | ||
158 | /* | |
159 | * sfi_map_table() | |
160 | * | |
161 | * Return address of mapped table | |
162 | * Check for common case that we can re-use mapping to SYST, | |
163 | * which requires syst_pa, syst_va to be initialized. | |
164 | */ | |
108cc2e7 | 165 | static struct sfi_table_header *sfi_map_table(u64 pa) |
6ae6996a FT |
166 | { |
167 | struct sfi_table_header *th; | |
168 | u32 length; | |
169 | ||
170 | if (!TABLE_ON_PAGE(syst_pa, pa, sizeof(struct sfi_table_header))) | |
171 | th = sfi_map_memory(pa, sizeof(struct sfi_table_header)); | |
172 | else | |
173 | th = (void *)syst_va + (pa - syst_pa); | |
174 | ||
175 | /* If table fits on same page as its header, we are done */ | |
176 | if (TABLE_ON_PAGE(th, th, th->len)) | |
177 | return th; | |
178 | ||
179 | /* Entire table does not fit on same page as SYST */ | |
180 | length = th->len; | |
181 | if (!TABLE_ON_PAGE(syst_pa, pa, sizeof(struct sfi_table_header))) | |
182 | sfi_unmap_memory(th, sizeof(struct sfi_table_header)); | |
183 | ||
184 | return sfi_map_memory(pa, length); | |
185 | } | |
186 | ||
187 | /* | |
188 | * sfi_unmap_table() | |
189 | * | |
190 | * Undoes effect of sfi_map_table() by unmapping table | |
191 | * if it did not completely fit on same page as SYST. | |
192 | */ | |
108cc2e7 | 193 | static void sfi_unmap_table(struct sfi_table_header *th) |
6ae6996a FT |
194 | { |
195 | if (!TABLE_ON_PAGE(syst_va, th, th->len)) | |
196 | sfi_unmap_memory(th, TABLE_ON_PAGE(th, th, th->len) ? | |
197 | sizeof(*th) : th->len); | |
198 | } | |
199 | ||
200 | static int sfi_table_check_key(struct sfi_table_header *th, | |
201 | struct sfi_table_key *key) | |
202 | { | |
203 | ||
204 | if (strncmp(th->sig, key->sig, SFI_SIGNATURE_SIZE) | |
205 | || (key->oem_id && strncmp(th->oem_id, | |
206 | key->oem_id, SFI_OEM_ID_SIZE)) | |
207 | || (key->oem_table_id && strncmp(th->oem_table_id, | |
208 | key->oem_table_id, SFI_OEM_TABLE_ID_SIZE))) | |
209 | return -1; | |
210 | ||
211 | return 0; | |
212 | } | |
213 | ||
214 | /* | |
215 | * This function will be used in 2 cases: | |
216 | * 1. used to enumerate and verify the tables addressed by SYST/XSDT, | |
217 | * thus no signature will be given (in kernel boot phase) | |
218 | * 2. used to parse one specific table, signature must exist, and | |
219 | * the mapped virt address will be returned, and the virt space | |
220 | * will be released by call sfi_put_table() later | |
221 | * | |
01674da6 RM |
222 | * This two cases are from two different functions with two different |
223 | * sections and causes section mismatch warning. So use __ref to tell | |
224 | * modpost not to make any noise. | |
225 | * | |
6ae6996a FT |
226 | * Return value: |
227 | * NULL: when can't find a table matching the key | |
228 | * ERR_PTR(error): error value | |
229 | * virt table address: when a matched table is found | |
230 | */ | |
01674da6 RM |
231 | struct sfi_table_header * |
232 | __ref sfi_check_table(u64 pa, struct sfi_table_key *key) | |
6ae6996a FT |
233 | { |
234 | struct sfi_table_header *th; | |
235 | void *ret = NULL; | |
236 | ||
237 | th = sfi_map_table(pa); | |
238 | if (!th) | |
239 | return ERR_PTR(-ENOMEM); | |
240 | ||
241 | if (!key->sig) { | |
242 | sfi_print_table_header(pa, th); | |
243 | if (sfi_verify_table(th)) | |
244 | ret = ERR_PTR(-EINVAL); | |
245 | } else { | |
246 | if (!sfi_table_check_key(th, key)) | |
247 | return th; /* Success */ | |
248 | } | |
249 | ||
250 | sfi_unmap_table(th); | |
251 | return ret; | |
252 | } | |
253 | ||
254 | /* | |
255 | * sfi_get_table() | |
256 | * | |
257 | * Search SYST for the specified table with the signature in | |
258 | * the key, and return the mapped table | |
259 | */ | |
260 | struct sfi_table_header *sfi_get_table(struct sfi_table_key *key) | |
261 | { | |
262 | struct sfi_table_header *th; | |
263 | u32 tbl_cnt, i; | |
264 | ||
265 | tbl_cnt = SFI_GET_NUM_ENTRIES(syst_va, u64); | |
266 | for (i = 0; i < tbl_cnt; i++) { | |
267 | th = sfi_check_table(syst_va->pentry[i], key); | |
268 | if (!IS_ERR(th) && th) | |
269 | return th; | |
270 | } | |
271 | ||
272 | return NULL; | |
273 | } | |
274 | ||
275 | void sfi_put_table(struct sfi_table_header *th) | |
276 | { | |
277 | sfi_unmap_table(th); | |
278 | } | |
279 | ||
280 | /* Find table with signature, run handler on it */ | |
281 | int sfi_table_parse(char *signature, char *oem_id, char *oem_table_id, | |
282 | sfi_table_handler handler) | |
283 | { | |
284 | struct sfi_table_header *table = NULL; | |
285 | struct sfi_table_key key; | |
286 | int ret = -EINVAL; | |
287 | ||
288 | if (sfi_disabled || !handler || !signature) | |
289 | goto exit; | |
290 | ||
291 | key.sig = signature; | |
292 | key.oem_id = oem_id; | |
293 | key.oem_table_id = oem_table_id; | |
294 | ||
295 | table = sfi_get_table(&key); | |
296 | if (!table) | |
297 | goto exit; | |
298 | ||
299 | ret = handler(table); | |
300 | sfi_put_table(table); | |
301 | exit: | |
302 | return ret; | |
303 | } | |
304 | EXPORT_SYMBOL_GPL(sfi_table_parse); | |
305 | ||
306 | /* | |
307 | * sfi_parse_syst() | |
308 | * Checksum all the tables in SYST and print their headers | |
309 | * | |
310 | * success: set syst_va, return 0 | |
311 | */ | |
312 | static int __init sfi_parse_syst(void) | |
313 | { | |
314 | struct sfi_table_key key = SFI_ANY_KEY; | |
315 | int tbl_cnt, i; | |
316 | void *ret; | |
317 | ||
318 | syst_va = sfi_map_memory(syst_pa, sizeof(struct sfi_table_simple)); | |
319 | if (!syst_va) | |
320 | return -ENOMEM; | |
321 | ||
322 | tbl_cnt = SFI_GET_NUM_ENTRIES(syst_va, u64); | |
323 | for (i = 0; i < tbl_cnt; i++) { | |
324 | ret = sfi_check_table(syst_va->pentry[i], &key); | |
325 | if (IS_ERR(ret)) | |
326 | return PTR_ERR(ret); | |
327 | } | |
328 | ||
329 | return 0; | |
330 | } | |
331 | ||
332 | /* | |
333 | * The OS finds the System Table by searching 16-byte boundaries between | |
334 | * physical address 0x000E0000 and 0x000FFFFF. The OS shall search this region | |
335 | * starting at the low address and shall stop searching when the 1st valid SFI | |
336 | * System Table is found. | |
337 | * | |
338 | * success: set syst_pa, return 0 | |
339 | * fail: return -1 | |
340 | */ | |
341 | static __init int sfi_find_syst(void) | |
342 | { | |
343 | unsigned long offset, len; | |
344 | void *start; | |
345 | ||
346 | len = SFI_SYST_SEARCH_END - SFI_SYST_SEARCH_BEGIN; | |
347 | start = sfi_map_memory(SFI_SYST_SEARCH_BEGIN, len); | |
348 | if (!start) | |
349 | return -1; | |
350 | ||
351 | for (offset = 0; offset < len; offset += 16) { | |
352 | struct sfi_table_header *syst_hdr; | |
353 | ||
354 | syst_hdr = start + offset; | |
355 | if (strncmp(syst_hdr->sig, SFI_SIG_SYST, | |
356 | SFI_SIGNATURE_SIZE)) | |
357 | continue; | |
358 | ||
359 | if (syst_hdr->len > PAGE_SIZE) | |
360 | continue; | |
361 | ||
362 | sfi_print_table_header(SFI_SYST_SEARCH_BEGIN + offset, | |
363 | syst_hdr); | |
364 | ||
365 | if (sfi_verify_table(syst_hdr)) | |
366 | continue; | |
367 | ||
368 | /* | |
369 | * Enforce SFI spec mandate that SYST reside within a page. | |
370 | */ | |
371 | if (!ON_SAME_PAGE(syst_pa, syst_pa + syst_hdr->len)) { | |
372 | pr_info("SYST 0x%llx + 0x%x crosses page\n", | |
373 | syst_pa, syst_hdr->len); | |
374 | continue; | |
375 | } | |
376 | ||
377 | /* Success */ | |
378 | syst_pa = SFI_SYST_SEARCH_BEGIN + offset; | |
379 | sfi_unmap_memory(start, len); | |
380 | return 0; | |
381 | } | |
382 | ||
383 | sfi_unmap_memory(start, len); | |
384 | return -1; | |
385 | } | |
386 | ||
dce80a56 FT |
387 | static struct kobject *sfi_kobj; |
388 | static struct kobject *tables_kobj; | |
389 | ||
390 | static ssize_t sfi_table_show(struct file *filp, struct kobject *kobj, | |
391 | struct bin_attribute *bin_attr, char *buf, | |
392 | loff_t offset, size_t count) | |
393 | { | |
394 | struct sfi_table_attr *tbl_attr = | |
395 | container_of(bin_attr, struct sfi_table_attr, attr); | |
396 | struct sfi_table_header *th = NULL; | |
397 | struct sfi_table_key key; | |
398 | ssize_t cnt; | |
399 | ||
400 | key.sig = tbl_attr->name; | |
401 | key.oem_id = NULL; | |
402 | key.oem_table_id = NULL; | |
403 | ||
404 | if (strncmp(SFI_SIG_SYST, tbl_attr->name, SFI_SIGNATURE_SIZE)) { | |
405 | th = sfi_get_table(&key); | |
406 | if (!th) | |
407 | return 0; | |
408 | ||
409 | cnt = memory_read_from_buffer(buf, count, &offset, | |
410 | th, th->len); | |
411 | sfi_put_table(th); | |
412 | } else | |
413 | cnt = memory_read_from_buffer(buf, count, &offset, | |
414 | syst_va, syst_va->header.len); | |
415 | ||
416 | return cnt; | |
417 | } | |
418 | ||
419 | struct sfi_table_attr __init *sfi_sysfs_install_table(u64 pa) | |
420 | { | |
421 | struct sfi_table_attr *tbl_attr; | |
422 | struct sfi_table_header *th; | |
423 | int ret; | |
424 | ||
425 | tbl_attr = kzalloc(sizeof(struct sfi_table_attr), GFP_KERNEL); | |
426 | if (!tbl_attr) | |
427 | return NULL; | |
428 | ||
429 | th = sfi_map_table(pa); | |
430 | if (!th || !th->sig[0]) { | |
431 | kfree(tbl_attr); | |
432 | return NULL; | |
433 | } | |
434 | ||
435 | sysfs_attr_init(&tbl_attr->attr.attr); | |
436 | memcpy(tbl_attr->name, th->sig, SFI_SIGNATURE_SIZE); | |
437 | ||
438 | tbl_attr->attr.size = 0; | |
439 | tbl_attr->attr.read = sfi_table_show; | |
440 | tbl_attr->attr.attr.name = tbl_attr->name; | |
441 | tbl_attr->attr.attr.mode = 0400; | |
442 | ||
443 | ret = sysfs_create_bin_file(tables_kobj, | |
444 | &tbl_attr->attr); | |
e29df91e | 445 | if (ret) { |
dce80a56 | 446 | kfree(tbl_attr); |
e29df91e DC |
447 | tbl_attr = NULL; |
448 | } | |
dce80a56 FT |
449 | |
450 | sfi_unmap_table(th); | |
451 | return tbl_attr; | |
452 | } | |
453 | ||
454 | static int __init sfi_sysfs_init(void) | |
455 | { | |
456 | int tbl_cnt, i; | |
457 | ||
458 | if (sfi_disabled) | |
459 | return 0; | |
460 | ||
461 | sfi_kobj = kobject_create_and_add("sfi", firmware_kobj); | |
462 | if (!sfi_kobj) | |
463 | return 0; | |
464 | ||
465 | tables_kobj = kobject_create_and_add("tables", sfi_kobj); | |
466 | if (!tables_kobj) { | |
467 | kobject_put(sfi_kobj); | |
468 | return 0; | |
469 | } | |
470 | ||
471 | sfi_sysfs_install_table(syst_pa); | |
472 | ||
473 | tbl_cnt = SFI_GET_NUM_ENTRIES(syst_va, u64); | |
474 | ||
475 | for (i = 0; i < tbl_cnt; i++) | |
476 | sfi_sysfs_install_table(syst_va->pentry[i]); | |
477 | ||
478 | sfi_acpi_sysfs_init(); | |
479 | kobject_uevent(sfi_kobj, KOBJ_ADD); | |
480 | kobject_uevent(tables_kobj, KOBJ_ADD); | |
481 | pr_info("SFI sysfs interfaces init success\n"); | |
482 | return 0; | |
483 | } | |
484 | ||
6ae6996a FT |
485 | void __init sfi_init(void) |
486 | { | |
487 | if (!acpi_disabled) | |
488 | disable_sfi(); | |
489 | ||
490 | if (sfi_disabled) | |
491 | return; | |
492 | ||
5487ab4a | 493 | pr_info("Simple Firmware Interface v0.81 http://simplefirmware.org\n"); |
6ae6996a FT |
494 | |
495 | if (sfi_find_syst() || sfi_parse_syst() || sfi_platform_init()) | |
496 | disable_sfi(); | |
497 | ||
498 | return; | |
499 | } | |
500 | ||
501 | void __init sfi_init_late(void) | |
502 | { | |
503 | int length; | |
504 | ||
505 | if (sfi_disabled) | |
506 | return; | |
507 | ||
508 | length = syst_va->header.len; | |
509 | sfi_unmap_memory(syst_va, sizeof(struct sfi_table_simple)); | |
510 | ||
f7750a79 TL |
511 | /* Use memremap now after it is ready */ |
512 | sfi_use_memremap = 1; | |
6ae6996a FT |
513 | syst_va = sfi_map_memory(syst_pa, length); |
514 | ||
515 | sfi_acpi_init(); | |
516 | } | |
dce80a56 FT |
517 | |
518 | /* | |
25985edc | 519 | * The reason we put it here because we need wait till the /sys/firmware |
dce80a56 FT |
520 | * is setup, then our interface can be registered in /sys/firmware/sfi |
521 | */ | |
522 | core_initcall(sfi_sysfs_init); |