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Feng Tang6ae69962009-08-14 15:13:46 -04001/* 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>
Feng Tang6ae69962009-08-14 15:13:46 -040065#include <linux/errno.h>
66#include <linux/types.h>
67#include <linux/acpi.h>
68#include <linux/init.h>
Feng Tang6ae69962009-08-14 15:13:46 -040069#include <linux/sfi.h>
Feng Tangdce80a52010-05-26 11:28:08 +080070#include <linux/slab.h>
Feng Tang6ae69962009-08-14 15:13:46 -040071
72#include "sfi_core.h"
73
74#define ON_SAME_PAGE(addr1, addr2) \
75 (((unsigned long)(addr1) & PAGE_MASK) == \
76 ((unsigned long)(addr2) & PAGE_MASK))
77#define TABLE_ON_PAGE(page, table, size) (ON_SAME_PAGE(page, table) && \
78 ON_SAME_PAGE(page, table + size))
79
80int sfi_disabled __read_mostly;
81EXPORT_SYMBOL(sfi_disabled);
82
83static u64 syst_pa __read_mostly;
84static struct sfi_table_simple *syst_va __read_mostly;
85
86/*
87 * FW creates and saves the SFI tables in memory. When these tables get
88 * used, they may need to be mapped to virtual address space, and the mapping
89 * can happen before or after the ioremap() is ready, so a flag is needed
90 * to indicating this
91 */
92static u32 sfi_use_ioremap __read_mostly;
93
Rakib Mullick01674da2009-09-30 16:09:55 -070094/*
95 * sfi_un/map_memory calls early_ioremap/iounmap which is a __init function
96 * and introduces section mismatch. So use __ref to make it calm.
97 */
98static void __iomem * __ref sfi_map_memory(u64 phys, u32 size)
Feng Tang6ae69962009-08-14 15:13:46 -040099{
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
Rakib Mullick01674da2009-09-30 16:09:55 -0700109static void __ref sfi_unmap_memory(void __iomem *virt, u32 size)
Feng Tang6ae69962009-08-14 15:13:46 -0400110{
111 if (!virt || !size)
112 return;
113
114 if (sfi_use_ioremap)
115 iounmap(virt);
116 else
117 early_iounmap(virt, size);
118}
119
120static 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 */
Arjan van de Ven011a6062009-10-02 07:29:47 -0700133static int sfi_verify_table(struct sfi_table_header *table)
Feng Tang6ae69962009-08-14 15:13:46 -0400134{
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 */
164struct 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 */
192void 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
199static 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 *
Rakib Mullick01674da2009-09-30 16:09:55 -0700221 * This two cases are from two different functions with two different
222 * sections and causes section mismatch warning. So use __ref to tell
223 * modpost not to make any noise.
224 *
Feng Tang6ae69962009-08-14 15:13:46 -0400225 * Return value:
226 * NULL: when can't find a table matching the key
227 * ERR_PTR(error): error value
228 * virt table address: when a matched table is found
229 */
Rakib Mullick01674da2009-09-30 16:09:55 -0700230struct sfi_table_header *
231 __ref sfi_check_table(u64 pa, struct sfi_table_key *key)
Feng Tang6ae69962009-08-14 15:13:46 -0400232{
233 struct sfi_table_header *th;
234 void *ret = NULL;
235
236 th = sfi_map_table(pa);
237 if (!th)
238 return ERR_PTR(-ENOMEM);
239
240 if (!key->sig) {
241 sfi_print_table_header(pa, th);
242 if (sfi_verify_table(th))
243 ret = ERR_PTR(-EINVAL);
244 } else {
245 if (!sfi_table_check_key(th, key))
246 return th; /* Success */
247 }
248
249 sfi_unmap_table(th);
250 return ret;
251}
252
253/*
254 * sfi_get_table()
255 *
256 * Search SYST for the specified table with the signature in
257 * the key, and return the mapped table
258 */
259struct sfi_table_header *sfi_get_table(struct sfi_table_key *key)
260{
261 struct sfi_table_header *th;
262 u32 tbl_cnt, i;
263
264 tbl_cnt = SFI_GET_NUM_ENTRIES(syst_va, u64);
265 for (i = 0; i < tbl_cnt; i++) {
266 th = sfi_check_table(syst_va->pentry[i], key);
267 if (!IS_ERR(th) && th)
268 return th;
269 }
270
271 return NULL;
272}
273
274void sfi_put_table(struct sfi_table_header *th)
275{
276 sfi_unmap_table(th);
277}
278
279/* Find table with signature, run handler on it */
280int sfi_table_parse(char *signature, char *oem_id, char *oem_table_id,
281 sfi_table_handler handler)
282{
283 struct sfi_table_header *table = NULL;
284 struct sfi_table_key key;
285 int ret = -EINVAL;
286
287 if (sfi_disabled || !handler || !signature)
288 goto exit;
289
290 key.sig = signature;
291 key.oem_id = oem_id;
292 key.oem_table_id = oem_table_id;
293
294 table = sfi_get_table(&key);
295 if (!table)
296 goto exit;
297
298 ret = handler(table);
299 sfi_put_table(table);
300exit:
301 return ret;
302}
303EXPORT_SYMBOL_GPL(sfi_table_parse);
304
305/*
306 * sfi_parse_syst()
307 * Checksum all the tables in SYST and print their headers
308 *
309 * success: set syst_va, return 0
310 */
311static int __init sfi_parse_syst(void)
312{
313 struct sfi_table_key key = SFI_ANY_KEY;
314 int tbl_cnt, i;
315 void *ret;
316
317 syst_va = sfi_map_memory(syst_pa, sizeof(struct sfi_table_simple));
318 if (!syst_va)
319 return -ENOMEM;
320
321 tbl_cnt = SFI_GET_NUM_ENTRIES(syst_va, u64);
322 for (i = 0; i < tbl_cnt; i++) {
323 ret = sfi_check_table(syst_va->pentry[i], &key);
324 if (IS_ERR(ret))
325 return PTR_ERR(ret);
326 }
327
328 return 0;
329}
330
331/*
332 * The OS finds the System Table by searching 16-byte boundaries between
333 * physical address 0x000E0000 and 0x000FFFFF. The OS shall search this region
334 * starting at the low address and shall stop searching when the 1st valid SFI
335 * System Table is found.
336 *
337 * success: set syst_pa, return 0
338 * fail: return -1
339 */
340static __init int sfi_find_syst(void)
341{
342 unsigned long offset, len;
343 void *start;
344
345 len = SFI_SYST_SEARCH_END - SFI_SYST_SEARCH_BEGIN;
346 start = sfi_map_memory(SFI_SYST_SEARCH_BEGIN, len);
347 if (!start)
348 return -1;
349
350 for (offset = 0; offset < len; offset += 16) {
351 struct sfi_table_header *syst_hdr;
352
353 syst_hdr = start + offset;
354 if (strncmp(syst_hdr->sig, SFI_SIG_SYST,
355 SFI_SIGNATURE_SIZE))
356 continue;
357
358 if (syst_hdr->len > PAGE_SIZE)
359 continue;
360
361 sfi_print_table_header(SFI_SYST_SEARCH_BEGIN + offset,
362 syst_hdr);
363
364 if (sfi_verify_table(syst_hdr))
365 continue;
366
367 /*
368 * Enforce SFI spec mandate that SYST reside within a page.
369 */
370 if (!ON_SAME_PAGE(syst_pa, syst_pa + syst_hdr->len)) {
371 pr_info("SYST 0x%llx + 0x%x crosses page\n",
372 syst_pa, syst_hdr->len);
373 continue;
374 }
375
376 /* Success */
377 syst_pa = SFI_SYST_SEARCH_BEGIN + offset;
378 sfi_unmap_memory(start, len);
379 return 0;
380 }
381
382 sfi_unmap_memory(start, len);
383 return -1;
384}
385
Feng Tangdce80a52010-05-26 11:28:08 +0800386static struct kobject *sfi_kobj;
387static struct kobject *tables_kobj;
388
389static ssize_t sfi_table_show(struct file *filp, struct kobject *kobj,
390 struct bin_attribute *bin_attr, char *buf,
391 loff_t offset, size_t count)
392{
393 struct sfi_table_attr *tbl_attr =
394 container_of(bin_attr, struct sfi_table_attr, attr);
395 struct sfi_table_header *th = NULL;
396 struct sfi_table_key key;
397 ssize_t cnt;
398
399 key.sig = tbl_attr->name;
400 key.oem_id = NULL;
401 key.oem_table_id = NULL;
402
403 if (strncmp(SFI_SIG_SYST, tbl_attr->name, SFI_SIGNATURE_SIZE)) {
404 th = sfi_get_table(&key);
405 if (!th)
406 return 0;
407
408 cnt = memory_read_from_buffer(buf, count, &offset,
409 th, th->len);
410 sfi_put_table(th);
411 } else
412 cnt = memory_read_from_buffer(buf, count, &offset,
413 syst_va, syst_va->header.len);
414
415 return cnt;
416}
417
418struct sfi_table_attr __init *sfi_sysfs_install_table(u64 pa)
419{
420 struct sfi_table_attr *tbl_attr;
421 struct sfi_table_header *th;
422 int ret;
423
424 tbl_attr = kzalloc(sizeof(struct sfi_table_attr), GFP_KERNEL);
425 if (!tbl_attr)
426 return NULL;
427
428 th = sfi_map_table(pa);
429 if (!th || !th->sig[0]) {
430 kfree(tbl_attr);
431 return NULL;
432 }
433
434 sysfs_attr_init(&tbl_attr->attr.attr);
435 memcpy(tbl_attr->name, th->sig, SFI_SIGNATURE_SIZE);
436
437 tbl_attr->attr.size = 0;
438 tbl_attr->attr.read = sfi_table_show;
439 tbl_attr->attr.attr.name = tbl_attr->name;
440 tbl_attr->attr.attr.mode = 0400;
441
442 ret = sysfs_create_bin_file(tables_kobj,
443 &tbl_attr->attr);
Dan Carpentere29df912010-05-28 12:33:15 +0200444 if (ret) {
Feng Tangdce80a52010-05-26 11:28:08 +0800445 kfree(tbl_attr);
Dan Carpentere29df912010-05-28 12:33:15 +0200446 tbl_attr = NULL;
447 }
Feng Tangdce80a52010-05-26 11:28:08 +0800448
449 sfi_unmap_table(th);
450 return tbl_attr;
451}
452
453static int __init sfi_sysfs_init(void)
454{
455 int tbl_cnt, i;
456
457 if (sfi_disabled)
458 return 0;
459
460 sfi_kobj = kobject_create_and_add("sfi", firmware_kobj);
461 if (!sfi_kobj)
462 return 0;
463
464 tables_kobj = kobject_create_and_add("tables", sfi_kobj);
465 if (!tables_kobj) {
466 kobject_put(sfi_kobj);
467 return 0;
468 }
469
470 sfi_sysfs_install_table(syst_pa);
471
472 tbl_cnt = SFI_GET_NUM_ENTRIES(syst_va, u64);
473
474 for (i = 0; i < tbl_cnt; i++)
475 sfi_sysfs_install_table(syst_va->pentry[i]);
476
477 sfi_acpi_sysfs_init();
478 kobject_uevent(sfi_kobj, KOBJ_ADD);
479 kobject_uevent(tables_kobj, KOBJ_ADD);
480 pr_info("SFI sysfs interfaces init success\n");
481 return 0;
482}
483
Feng Tang6ae69962009-08-14 15:13:46 -0400484void __init sfi_init(void)
485{
486 if (!acpi_disabled)
487 disable_sfi();
488
489 if (sfi_disabled)
490 return;
491
Feng Tang5487ab42010-05-25 16:40:47 +0800492 pr_info("Simple Firmware Interface v0.81 http://simplefirmware.org\n");
Feng Tang6ae69962009-08-14 15:13:46 -0400493
494 if (sfi_find_syst() || sfi_parse_syst() || sfi_platform_init())
495 disable_sfi();
496
497 return;
498}
499
500void __init sfi_init_late(void)
501{
502 int length;
503
504 if (sfi_disabled)
505 return;
506
507 length = syst_va->header.len;
508 sfi_unmap_memory(syst_va, sizeof(struct sfi_table_simple));
509
510 /* Use ioremap now after it is ready */
511 sfi_use_ioremap = 1;
512 syst_va = sfi_map_memory(syst_pa, length);
513
514 sfi_acpi_init();
515}
Feng Tangdce80a52010-05-26 11:28:08 +0800516
517/*
518 * The reason we put it here becasue we need wait till the /sys/firmware
519 * is setup, then our interface can be registered in /sys/firmware/sfi
520 */
521core_initcall(sfi_sysfs_init);