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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> | |
65 | #include <linux/string.h> | |
66 | #include <linux/errno.h> | |
67 | #include <linux/types.h> | |
68 | #include <linux/acpi.h> | |
69 | #include <linux/init.h> | |
70 | #include <linux/irq.h> | |
71 | #include <linux/sfi.h> | |
72 | #include <linux/smp.h> | |
73 | ||
74 | #include <asm/pgtable.h> | |
75 | ||
76 | #include "sfi_core.h" | |
77 | ||
78 | #define ON_SAME_PAGE(addr1, addr2) \ | |
79 | (((unsigned long)(addr1) & PAGE_MASK) == \ | |
80 | ((unsigned long)(addr2) & PAGE_MASK)) | |
81 | #define TABLE_ON_PAGE(page, table, size) (ON_SAME_PAGE(page, table) && \ | |
82 | ON_SAME_PAGE(page, table + size)) | |
83 | ||
84 | int sfi_disabled __read_mostly; | |
85 | EXPORT_SYMBOL(sfi_disabled); | |
86 | ||
87 | static u64 syst_pa __read_mostly; | |
88 | static struct sfi_table_simple *syst_va __read_mostly; | |
89 | ||
90 | /* | |
91 | * FW creates and saves the SFI tables in memory. When these tables get | |
92 | * used, they may need to be mapped to virtual address space, and the mapping | |
93 | * can happen before or after the ioremap() is ready, so a flag is needed | |
94 | * to indicating this | |
95 | */ | |
96 | static u32 sfi_use_ioremap __read_mostly; | |
97 | ||
98 | static void __iomem *sfi_map_memory(u64 phys, u32 size) | |
99 | { | |
100 | if (!phys || !size) | |
101 | return NULL; | |
102 | ||
103 | if (sfi_use_ioremap) | |
104 | return ioremap(phys, size); | |
105 | else | |
106 | return early_ioremap(phys, size); | |
107 | } | |
108 | ||
109 | static void sfi_unmap_memory(void __iomem *virt, u32 size) | |
110 | { | |
111 | if (!virt || !size) | |
112 | return; | |
113 | ||
114 | if (sfi_use_ioremap) | |
115 | iounmap(virt); | |
116 | else | |
117 | early_iounmap(virt, size); | |
118 | } | |
119 | ||
120 | static void sfi_print_table_header(unsigned long long pa, | |
121 | struct sfi_table_header *header) | |
122 | { | |
123 | pr_info("%4.4s %llX, %04X (v%d %6.6s %8.8s)\n", | |
124 | header->sig, pa, | |
125 | header->len, header->rev, header->oem_id, | |
126 | header->oem_table_id); | |
127 | } | |
128 | ||
129 | /* | |
130 | * sfi_verify_table() | |
131 | * Sanity check table lengh, calculate checksum | |
132 | */ | |
133 | static __init int sfi_verify_table(struct sfi_table_header *table) | |
134 | { | |
135 | ||
136 | u8 checksum = 0; | |
137 | u8 *puchar = (u8 *)table; | |
138 | u32 length = table->len; | |
139 | ||
140 | /* Sanity check table length against arbitrary 1MB limit */ | |
141 | if (length > 0x100000) { | |
142 | pr_err("Invalid table length 0x%x\n", length); | |
143 | return -1; | |
144 | } | |
145 | ||
146 | while (length--) | |
147 | checksum += *puchar++; | |
148 | ||
149 | if (checksum) { | |
150 | pr_err("Checksum %2.2X should be %2.2X\n", | |
151 | table->csum, table->csum - checksum); | |
152 | return -1; | |
153 | } | |
154 | return 0; | |
155 | } | |
156 | ||
157 | /* | |
158 | * sfi_map_table() | |
159 | * | |
160 | * Return address of mapped table | |
161 | * Check for common case that we can re-use mapping to SYST, | |
162 | * which requires syst_pa, syst_va to be initialized. | |
163 | */ | |
164 | struct sfi_table_header *sfi_map_table(u64 pa) | |
165 | { | |
166 | struct sfi_table_header *th; | |
167 | u32 length; | |
168 | ||
169 | if (!TABLE_ON_PAGE(syst_pa, pa, sizeof(struct sfi_table_header))) | |
170 | th = sfi_map_memory(pa, sizeof(struct sfi_table_header)); | |
171 | else | |
172 | th = (void *)syst_va + (pa - syst_pa); | |
173 | ||
174 | /* If table fits on same page as its header, we are done */ | |
175 | if (TABLE_ON_PAGE(th, th, th->len)) | |
176 | return th; | |
177 | ||
178 | /* Entire table does not fit on same page as SYST */ | |
179 | length = th->len; | |
180 | if (!TABLE_ON_PAGE(syst_pa, pa, sizeof(struct sfi_table_header))) | |
181 | sfi_unmap_memory(th, sizeof(struct sfi_table_header)); | |
182 | ||
183 | return sfi_map_memory(pa, length); | |
184 | } | |
185 | ||
186 | /* | |
187 | * sfi_unmap_table() | |
188 | * | |
189 | * Undoes effect of sfi_map_table() by unmapping table | |
190 | * if it did not completely fit on same page as SYST. | |
191 | */ | |
192 | void sfi_unmap_table(struct sfi_table_header *th) | |
193 | { | |
194 | if (!TABLE_ON_PAGE(syst_va, th, th->len)) | |
195 | sfi_unmap_memory(th, TABLE_ON_PAGE(th, th, th->len) ? | |
196 | sizeof(*th) : th->len); | |
197 | } | |
198 | ||
199 | static int sfi_table_check_key(struct sfi_table_header *th, | |
200 | struct sfi_table_key *key) | |
201 | { | |
202 | ||
203 | if (strncmp(th->sig, key->sig, SFI_SIGNATURE_SIZE) | |
204 | || (key->oem_id && strncmp(th->oem_id, | |
205 | key->oem_id, SFI_OEM_ID_SIZE)) | |
206 | || (key->oem_table_id && strncmp(th->oem_table_id, | |
207 | key->oem_table_id, SFI_OEM_TABLE_ID_SIZE))) | |
208 | return -1; | |
209 | ||
210 | return 0; | |
211 | } | |
212 | ||
213 | /* | |
214 | * This function will be used in 2 cases: | |
215 | * 1. used to enumerate and verify the tables addressed by SYST/XSDT, | |
216 | * thus no signature will be given (in kernel boot phase) | |
217 | * 2. used to parse one specific table, signature must exist, and | |
218 | * the mapped virt address will be returned, and the virt space | |
219 | * will be released by call sfi_put_table() later | |
220 | * | |
221 | * Return value: | |
222 | * NULL: when can't find a table matching the key | |
223 | * ERR_PTR(error): error value | |
224 | * virt table address: when a matched table is found | |
225 | */ | |
226 | struct sfi_table_header *sfi_check_table(u64 pa, struct sfi_table_key *key) | |
227 | { | |
228 | struct sfi_table_header *th; | |
229 | void *ret = NULL; | |
230 | ||
231 | th = sfi_map_table(pa); | |
232 | if (!th) | |
233 | return ERR_PTR(-ENOMEM); | |
234 | ||
235 | if (!key->sig) { | |
236 | sfi_print_table_header(pa, th); | |
237 | if (sfi_verify_table(th)) | |
238 | ret = ERR_PTR(-EINVAL); | |
239 | } else { | |
240 | if (!sfi_table_check_key(th, key)) | |
241 | return th; /* Success */ | |
242 | } | |
243 | ||
244 | sfi_unmap_table(th); | |
245 | return ret; | |
246 | } | |
247 | ||
248 | /* | |
249 | * sfi_get_table() | |
250 | * | |
251 | * Search SYST for the specified table with the signature in | |
252 | * the key, and return the mapped table | |
253 | */ | |
254 | struct sfi_table_header *sfi_get_table(struct sfi_table_key *key) | |
255 | { | |
256 | struct sfi_table_header *th; | |
257 | u32 tbl_cnt, i; | |
258 | ||
259 | tbl_cnt = SFI_GET_NUM_ENTRIES(syst_va, u64); | |
260 | for (i = 0; i < tbl_cnt; i++) { | |
261 | th = sfi_check_table(syst_va->pentry[i], key); | |
262 | if (!IS_ERR(th) && th) | |
263 | return th; | |
264 | } | |
265 | ||
266 | return NULL; | |
267 | } | |
268 | ||
269 | void sfi_put_table(struct sfi_table_header *th) | |
270 | { | |
271 | sfi_unmap_table(th); | |
272 | } | |
273 | ||
274 | /* Find table with signature, run handler on it */ | |
275 | int sfi_table_parse(char *signature, char *oem_id, char *oem_table_id, | |
276 | sfi_table_handler handler) | |
277 | { | |
278 | struct sfi_table_header *table = NULL; | |
279 | struct sfi_table_key key; | |
280 | int ret = -EINVAL; | |
281 | ||
282 | if (sfi_disabled || !handler || !signature) | |
283 | goto exit; | |
284 | ||
285 | key.sig = signature; | |
286 | key.oem_id = oem_id; | |
287 | key.oem_table_id = oem_table_id; | |
288 | ||
289 | table = sfi_get_table(&key); | |
290 | if (!table) | |
291 | goto exit; | |
292 | ||
293 | ret = handler(table); | |
294 | sfi_put_table(table); | |
295 | exit: | |
296 | return ret; | |
297 | } | |
298 | EXPORT_SYMBOL_GPL(sfi_table_parse); | |
299 | ||
300 | /* | |
301 | * sfi_parse_syst() | |
302 | * Checksum all the tables in SYST and print their headers | |
303 | * | |
304 | * success: set syst_va, return 0 | |
305 | */ | |
306 | static int __init sfi_parse_syst(void) | |
307 | { | |
308 | struct sfi_table_key key = SFI_ANY_KEY; | |
309 | int tbl_cnt, i; | |
310 | void *ret; | |
311 | ||
312 | syst_va = sfi_map_memory(syst_pa, sizeof(struct sfi_table_simple)); | |
313 | if (!syst_va) | |
314 | return -ENOMEM; | |
315 | ||
316 | tbl_cnt = SFI_GET_NUM_ENTRIES(syst_va, u64); | |
317 | for (i = 0; i < tbl_cnt; i++) { | |
318 | ret = sfi_check_table(syst_va->pentry[i], &key); | |
319 | if (IS_ERR(ret)) | |
320 | return PTR_ERR(ret); | |
321 | } | |
322 | ||
323 | return 0; | |
324 | } | |
325 | ||
326 | /* | |
327 | * The OS finds the System Table by searching 16-byte boundaries between | |
328 | * physical address 0x000E0000 and 0x000FFFFF. The OS shall search this region | |
329 | * starting at the low address and shall stop searching when the 1st valid SFI | |
330 | * System Table is found. | |
331 | * | |
332 | * success: set syst_pa, return 0 | |
333 | * fail: return -1 | |
334 | */ | |
335 | static __init int sfi_find_syst(void) | |
336 | { | |
337 | unsigned long offset, len; | |
338 | void *start; | |
339 | ||
340 | len = SFI_SYST_SEARCH_END - SFI_SYST_SEARCH_BEGIN; | |
341 | start = sfi_map_memory(SFI_SYST_SEARCH_BEGIN, len); | |
342 | if (!start) | |
343 | return -1; | |
344 | ||
345 | for (offset = 0; offset < len; offset += 16) { | |
346 | struct sfi_table_header *syst_hdr; | |
347 | ||
348 | syst_hdr = start + offset; | |
349 | if (strncmp(syst_hdr->sig, SFI_SIG_SYST, | |
350 | SFI_SIGNATURE_SIZE)) | |
351 | continue; | |
352 | ||
353 | if (syst_hdr->len > PAGE_SIZE) | |
354 | continue; | |
355 | ||
356 | sfi_print_table_header(SFI_SYST_SEARCH_BEGIN + offset, | |
357 | syst_hdr); | |
358 | ||
359 | if (sfi_verify_table(syst_hdr)) | |
360 | continue; | |
361 | ||
362 | /* | |
363 | * Enforce SFI spec mandate that SYST reside within a page. | |
364 | */ | |
365 | if (!ON_SAME_PAGE(syst_pa, syst_pa + syst_hdr->len)) { | |
366 | pr_info("SYST 0x%llx + 0x%x crosses page\n", | |
367 | syst_pa, syst_hdr->len); | |
368 | continue; | |
369 | } | |
370 | ||
371 | /* Success */ | |
372 | syst_pa = SFI_SYST_SEARCH_BEGIN + offset; | |
373 | sfi_unmap_memory(start, len); | |
374 | return 0; | |
375 | } | |
376 | ||
377 | sfi_unmap_memory(start, len); | |
378 | return -1; | |
379 | } | |
380 | ||
381 | void __init sfi_init(void) | |
382 | { | |
383 | if (!acpi_disabled) | |
384 | disable_sfi(); | |
385 | ||
386 | if (sfi_disabled) | |
387 | return; | |
388 | ||
389 | pr_info("Simple Firmware Interface v0.7 http://simplefirmware.org\n"); | |
390 | ||
391 | if (sfi_find_syst() || sfi_parse_syst() || sfi_platform_init()) | |
392 | disable_sfi(); | |
393 | ||
394 | return; | |
395 | } | |
396 | ||
397 | void __init sfi_init_late(void) | |
398 | { | |
399 | int length; | |
400 | ||
401 | if (sfi_disabled) | |
402 | return; | |
403 | ||
404 | length = syst_va->header.len; | |
405 | sfi_unmap_memory(syst_va, sizeof(struct sfi_table_simple)); | |
406 | ||
407 | /* Use ioremap now after it is ready */ | |
408 | sfi_use_ioremap = 1; | |
409 | syst_va = sfi_map_memory(syst_pa, length); | |
410 | ||
411 | sfi_acpi_init(); | |
412 | } |