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1 | /* |
2 | * MTD Oops/Panic logger |
3 | * |
4 | * Copyright © 2007 Nokia Corporation. All rights reserved. |
5 | * |
6 | * Author: Richard Purdie <rpurdie@openedhand.com> |
7 | * |
8 | * This program is free software; you can redistribute it and/or |
9 | * modify it under the terms of the GNU General Public License |
10 | * version 2 as published by the Free Software Foundation. |
11 | * |
12 | * This program is distributed in the hope that it will be useful, but |
13 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
15 | * General Public License for more details. |
16 | * |
17 | * You should have received a copy of the GNU General Public License |
18 | * along with this program; if not, write to the Free Software |
19 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA |
20 | * 02110-1301 USA |
21 | * |
22 | */ |
23 | |
24 | #include <linux/kernel.h> |
25 | #include <linux/module.h> |
26 | #include <linux/console.h> |
27 | #include <linux/vmalloc.h> |
28 | #include <linux/workqueue.h> |
29 | #include <linux/sched.h> |
30 | #include <linux/wait.h> |
31 | #include <linux/delay.h> |
32 | #include <linux/interrupt.h> |
33 | #include <linux/mtd/mtd.h> |
34 | #include <linux/kmsg_dump.h> |
35 | |
36 | /* Maximum MTD partition size */ |
37 | #define MTDOOPS_MAX_MTD_SIZE (8 * 1024 * 1024) |
38 | |
39 | #define MTDOOPS_KERNMSG_MAGIC 0x5d005d00 |
40 | #define MTDOOPS_HEADER_SIZE 8 |
41 | |
42 | static unsigned long record_size = 4096; |
43 | module_param(record_size, ulong, 0400); |
44 | MODULE_PARM_DESC(record_size, |
45 | "record size for MTD OOPS pages in bytes (default 4096)"); |
46 | |
47 | static char mtddev[80]; |
48 | module_param_string(mtddev, mtddev, 80, 0400); |
49 | MODULE_PARM_DESC(mtddev, |
50 | "name or index number of the MTD device to use"); |
51 | |
52 | static int dump_oops = 1; |
53 | module_param(dump_oops, int, 0600); |
54 | MODULE_PARM_DESC(dump_oops, |
55 | "set to 1 to dump oopses, 0 to only dump panics (default 1)"); |
56 | |
57 | static struct mtdoops_context { |
58 | struct kmsg_dumper dump; |
59 | |
60 | int mtd_index; |
61 | struct work_struct work_erase; |
62 | struct work_struct work_write; |
63 | struct mtd_info *mtd; |
64 | int oops_pages; |
65 | int nextpage; |
66 | int nextcount; |
67 | unsigned long *oops_page_used; |
68 | |
69 | void *oops_buf; |
70 | } oops_cxt; |
71 | |
72 | static void mark_page_used(struct mtdoops_context *cxt, int page) |
73 | { |
74 | set_bit(page, cxt->oops_page_used); |
75 | } |
76 | |
77 | static void mark_page_unused(struct mtdoops_context *cxt, int page) |
78 | { |
79 | clear_bit(page, cxt->oops_page_used); |
80 | } |
81 | |
82 | static int page_is_used(struct mtdoops_context *cxt, int page) |
83 | { |
84 | return test_bit(page, cxt->oops_page_used); |
85 | } |
86 | |
87 | static void mtdoops_erase_callback(struct erase_info *done) |
88 | { |
89 | wait_queue_head_t *wait_q = (wait_queue_head_t *)done->priv; |
90 | wake_up(wait_q); |
91 | } |
92 | |
93 | static int mtdoops_erase_block(struct mtdoops_context *cxt, int offset) |
94 | { |
95 | struct mtd_info *mtd = cxt->mtd; |
96 | u32 start_page_offset = mtd_div_by_eb(offset, mtd) * mtd->erasesize; |
97 | u32 start_page = start_page_offset / record_size; |
98 | u32 erase_pages = mtd->erasesize / record_size; |
99 | struct erase_info erase; |
100 | DECLARE_WAITQUEUE(wait, current); |
101 | wait_queue_head_t wait_q; |
102 | int ret; |
103 | int page; |
104 | |
105 | init_waitqueue_head(&wait_q); |
106 | erase.mtd = mtd; |
107 | erase.callback = mtdoops_erase_callback; |
108 | erase.addr = offset; |
109 | erase.len = mtd->erasesize; |
110 | erase.priv = (u_long)&wait_q; |
111 | |
112 | set_current_state(TASK_INTERRUPTIBLE); |
113 | add_wait_queue(&wait_q, &wait); |
114 | |
115 | ret = mtd_erase(mtd, &erase); |
116 | if (ret) { |
117 | set_current_state(TASK_RUNNING); |
118 | remove_wait_queue(&wait_q, &wait); |
119 | printk(KERN_WARNING "mtdoops: erase of region [0x%llx, 0x%llx] on \"%s\" failed\n", |
120 | (unsigned long long)erase.addr, |
121 | (unsigned long long)erase.len, mtddev); |
122 | return ret; |
123 | } |
124 | |
125 | schedule(); /* Wait for erase to finish. */ |
126 | remove_wait_queue(&wait_q, &wait); |
127 | |
128 | /* Mark pages as unused */ |
129 | for (page = start_page; page < start_page + erase_pages; page++) |
130 | mark_page_unused(cxt, page); |
131 | |
132 | return 0; |
133 | } |
134 | |
135 | static void mtdoops_inc_counter(struct mtdoops_context *cxt) |
136 | { |
137 | cxt->nextpage++; |
138 | if (cxt->nextpage >= cxt->oops_pages) |
139 | cxt->nextpage = 0; |
140 | cxt->nextcount++; |
141 | if (cxt->nextcount == 0xffffffff) |
142 | cxt->nextcount = 0; |
143 | |
144 | if (page_is_used(cxt, cxt->nextpage)) { |
145 | schedule_work(&cxt->work_erase); |
146 | return; |
147 | } |
148 | |
149 | printk(KERN_DEBUG "mtdoops: ready %d, %d (no erase)\n", |
150 | cxt->nextpage, cxt->nextcount); |
151 | } |
152 | |
153 | /* Scheduled work - when we can't proceed without erasing a block */ |
154 | static void mtdoops_workfunc_erase(struct work_struct *work) |
155 | { |
156 | struct mtdoops_context *cxt = |
157 | container_of(work, struct mtdoops_context, work_erase); |
158 | struct mtd_info *mtd = cxt->mtd; |
159 | int i = 0, j, ret, mod; |
160 | |
161 | /* We were unregistered */ |
162 | if (!mtd) |
163 | return; |
164 | |
165 | mod = (cxt->nextpage * record_size) % mtd->erasesize; |
166 | if (mod != 0) { |
167 | cxt->nextpage = cxt->nextpage + ((mtd->erasesize - mod) / record_size); |
168 | if (cxt->nextpage >= cxt->oops_pages) |
169 | cxt->nextpage = 0; |
170 | } |
171 | |
172 | while ((ret = mtd_block_isbad(mtd, cxt->nextpage * record_size)) > 0) { |
173 | badblock: |
174 | printk(KERN_WARNING "mtdoops: bad block at %08lx\n", |
175 | cxt->nextpage * record_size); |
176 | i++; |
177 | cxt->nextpage = cxt->nextpage + (mtd->erasesize / record_size); |
178 | if (cxt->nextpage >= cxt->oops_pages) |
179 | cxt->nextpage = 0; |
180 | if (i == cxt->oops_pages / (mtd->erasesize / record_size)) { |
181 | printk(KERN_ERR "mtdoops: all blocks bad!\n"); |
182 | return; |
183 | } |
184 | } |
185 | |
186 | if (ret < 0) { |
187 | printk(KERN_ERR "mtdoops: mtd_block_isbad failed, aborting\n"); |
188 | return; |
189 | } |
190 | |
191 | for (j = 0, ret = -1; (j < 3) && (ret < 0); j++) |
192 | ret = mtdoops_erase_block(cxt, cxt->nextpage * record_size); |
193 | |
194 | if (ret >= 0) { |
195 | printk(KERN_DEBUG "mtdoops: ready %d, %d\n", |
196 | cxt->nextpage, cxt->nextcount); |
197 | return; |
198 | } |
199 | |
200 | if (ret == -EIO) { |
201 | ret = mtd_block_markbad(mtd, cxt->nextpage * record_size); |
202 | if (ret < 0 && ret != -EOPNOTSUPP) { |
203 | printk(KERN_ERR "mtdoops: block_markbad failed, aborting\n"); |
204 | return; |
205 | } |
206 | } |
207 | goto badblock; |
208 | } |
209 | |
210 | static void mtdoops_write(struct mtdoops_context *cxt, int panic) |
211 | { |
212 | struct mtd_info *mtd = cxt->mtd; |
213 | size_t retlen; |
214 | u32 *hdr; |
215 | int ret; |
216 | |
217 | /* Add mtdoops header to the buffer */ |
218 | hdr = cxt->oops_buf; |
219 | hdr[0] = cxt->nextcount; |
220 | hdr[1] = MTDOOPS_KERNMSG_MAGIC; |
221 | |
222 | if (panic) { |
223 | ret = mtd_panic_write(mtd, cxt->nextpage * record_size, |
224 | record_size, &retlen, cxt->oops_buf); |
225 | if (ret == -EOPNOTSUPP) { |
226 | printk(KERN_ERR "mtdoops: Cannot write from panic without panic_write\n"); |
227 | return; |
228 | } |
229 | } else |
230 | ret = mtd_write(mtd, cxt->nextpage * record_size, |
231 | record_size, &retlen, cxt->oops_buf); |
232 | |
233 | if (retlen != record_size || ret < 0) |
234 | printk(KERN_ERR "mtdoops: write failure at %ld (%td of %ld written), error %d\n", |
235 | cxt->nextpage * record_size, retlen, record_size, ret); |
236 | mark_page_used(cxt, cxt->nextpage); |
237 | memset(cxt->oops_buf, 0xff, record_size); |
238 | |
239 | mtdoops_inc_counter(cxt); |
240 | } |
241 | |
242 | static void mtdoops_workfunc_write(struct work_struct *work) |
243 | { |
244 | struct mtdoops_context *cxt = |
245 | container_of(work, struct mtdoops_context, work_write); |
246 | |
247 | mtdoops_write(cxt, 0); |
248 | } |
249 | |
250 | static void find_next_position(struct mtdoops_context *cxt) |
251 | { |
252 | struct mtd_info *mtd = cxt->mtd; |
253 | int ret, page, maxpos = 0; |
254 | u32 count[2], maxcount = 0xffffffff; |
255 | size_t retlen; |
256 | |
257 | for (page = 0; page < cxt->oops_pages; page++) { |
258 | if (mtd_block_isbad(mtd, page * record_size)) |
259 | continue; |
260 | /* Assume the page is used */ |
261 | mark_page_used(cxt, page); |
262 | ret = mtd_read(mtd, page * record_size, MTDOOPS_HEADER_SIZE, |
263 | &retlen, (u_char *)&count[0]); |
264 | if (retlen != MTDOOPS_HEADER_SIZE || |
265 | (ret < 0 && !mtd_is_bitflip(ret))) { |
266 | printk(KERN_ERR "mtdoops: read failure at %ld (%td of %d read), err %d\n", |
267 | page * record_size, retlen, |
268 | MTDOOPS_HEADER_SIZE, ret); |
269 | continue; |
270 | } |
271 | |
272 | if (count[0] == 0xffffffff && count[1] == 0xffffffff) |
273 | mark_page_unused(cxt, page); |
274 | if (count[0] == 0xffffffff || count[1] != MTDOOPS_KERNMSG_MAGIC) |
275 | continue; |
276 | if (maxcount == 0xffffffff) { |
277 | maxcount = count[0]; |
278 | maxpos = page; |
279 | } else if (count[0] < 0x40000000 && maxcount > 0xc0000000) { |
280 | maxcount = count[0]; |
281 | maxpos = page; |
282 | } else if (count[0] > maxcount && count[0] < 0xc0000000) { |
283 | maxcount = count[0]; |
284 | maxpos = page; |
285 | } else if (count[0] > maxcount && count[0] > 0xc0000000 |
286 | && maxcount > 0x80000000) { |
287 | maxcount = count[0]; |
288 | maxpos = page; |
289 | } |
290 | } |
291 | if (maxcount == 0xffffffff) { |
292 | cxt->nextpage = cxt->oops_pages - 1; |
293 | cxt->nextcount = 0; |
294 | } |
295 | else { |
296 | cxt->nextpage = maxpos; |
297 | cxt->nextcount = maxcount; |
298 | } |
299 | |
300 | mtdoops_inc_counter(cxt); |
301 | } |
302 | |
303 | static void mtdoops_do_dump(struct kmsg_dumper *dumper, |
304 | enum kmsg_dump_reason reason) |
305 | { |
306 | struct mtdoops_context *cxt = container_of(dumper, |
307 | struct mtdoops_context, dump); |
308 | |
309 | /* Only dump oopses if dump_oops is set */ |
310 | if (reason == KMSG_DUMP_OOPS && !dump_oops) |
311 | return; |
312 | |
313 | kmsg_dump_get_buffer(dumper, true, cxt->oops_buf + MTDOOPS_HEADER_SIZE, |
314 | record_size - MTDOOPS_HEADER_SIZE, NULL); |
315 | |
316 | /* Panics must be written immediately */ |
317 | if (reason != KMSG_DUMP_OOPS) |
318 | mtdoops_write(cxt, 1); |
319 | |
320 | /* For other cases, schedule work to write it "nicely" */ |
321 | schedule_work(&cxt->work_write); |
322 | } |
323 | |
324 | static void mtdoops_notify_add(struct mtd_info *mtd) |
325 | { |
326 | struct mtdoops_context *cxt = &oops_cxt; |
327 | u64 mtdoops_pages = div_u64(mtd->size, record_size); |
328 | int err; |
329 | |
330 | if (!strcmp(mtd->name, mtddev)) |
331 | cxt->mtd_index = mtd->index; |
332 | |
333 | if (mtd->index != cxt->mtd_index || cxt->mtd_index < 0) |
334 | return; |
335 | |
336 | if (mtd->size < mtd->erasesize * 2) { |
337 | printk(KERN_ERR "mtdoops: MTD partition %d not big enough for mtdoops\n", |
338 | mtd->index); |
339 | return; |
340 | } |
341 | if (mtd->erasesize < record_size) { |
342 | printk(KERN_ERR "mtdoops: eraseblock size of MTD partition %d too small\n", |
343 | mtd->index); |
344 | return; |
345 | } |
346 | if (mtd->size > MTDOOPS_MAX_MTD_SIZE) { |
347 | printk(KERN_ERR "mtdoops: mtd%d is too large (limit is %d MiB)\n", |
348 | mtd->index, MTDOOPS_MAX_MTD_SIZE / 1024 / 1024); |
349 | return; |
350 | } |
351 | |
352 | /* oops_page_used is a bit field */ |
353 | cxt->oops_page_used = vmalloc(DIV_ROUND_UP(mtdoops_pages, |
354 | BITS_PER_LONG) * sizeof(unsigned long)); |
355 | if (!cxt->oops_page_used) { |
356 | printk(KERN_ERR "mtdoops: could not allocate page array\n"); |
357 | return; |
358 | } |
359 | |
360 | cxt->dump.max_reason = KMSG_DUMP_OOPS; |
361 | cxt->dump.dump = mtdoops_do_dump; |
362 | err = kmsg_dump_register(&cxt->dump); |
363 | if (err) { |
364 | printk(KERN_ERR "mtdoops: registering kmsg dumper failed, error %d\n", err); |
365 | vfree(cxt->oops_page_used); |
366 | cxt->oops_page_used = NULL; |
367 | return; |
368 | } |
369 | |
370 | cxt->mtd = mtd; |
371 | cxt->oops_pages = (int)mtd->size / record_size; |
372 | find_next_position(cxt); |
373 | printk(KERN_INFO "mtdoops: Attached to MTD device %d\n", mtd->index); |
374 | } |
375 | |
376 | static void mtdoops_notify_remove(struct mtd_info *mtd) |
377 | { |
378 | struct mtdoops_context *cxt = &oops_cxt; |
379 | |
380 | if (mtd->index != cxt->mtd_index || cxt->mtd_index < 0) |
381 | return; |
382 | |
383 | if (kmsg_dump_unregister(&cxt->dump) < 0) |
384 | printk(KERN_WARNING "mtdoops: could not unregister kmsg_dumper\n"); |
385 | |
386 | cxt->mtd = NULL; |
387 | flush_work(&cxt->work_erase); |
388 | flush_work(&cxt->work_write); |
389 | } |
390 | |
391 | |
392 | static struct mtd_notifier mtdoops_notifier = { |
393 | .add = mtdoops_notify_add, |
394 | .remove = mtdoops_notify_remove, |
395 | }; |
396 | |
397 | static int __init mtdoops_init(void) |
398 | { |
399 | struct mtdoops_context *cxt = &oops_cxt; |
400 | int mtd_index; |
401 | char *endp; |
402 | |
403 | if (strlen(mtddev) == 0) { |
404 | printk(KERN_ERR "mtdoops: mtd device (mtddev=name/number) must be supplied\n"); |
405 | return -EINVAL; |
406 | } |
407 | if ((record_size & 4095) != 0) { |
408 | printk(KERN_ERR "mtdoops: record_size must be a multiple of 4096\n"); |
409 | return -EINVAL; |
410 | } |
411 | if (record_size < 4096) { |
412 | printk(KERN_ERR "mtdoops: record_size must be over 4096 bytes\n"); |
413 | return -EINVAL; |
414 | } |
415 | |
416 | /* Setup the MTD device to use */ |
417 | cxt->mtd_index = -1; |
418 | mtd_index = simple_strtoul(mtddev, &endp, 0); |
419 | if (*endp == '\0') |
420 | cxt->mtd_index = mtd_index; |
421 | |
422 | cxt->oops_buf = vmalloc(record_size); |
423 | if (!cxt->oops_buf) { |
424 | printk(KERN_ERR "mtdoops: failed to allocate buffer workspace\n"); |
425 | return -ENOMEM; |
426 | } |
427 | memset(cxt->oops_buf, 0xff, record_size); |
428 | |
429 | INIT_WORK(&cxt->work_erase, mtdoops_workfunc_erase); |
430 | INIT_WORK(&cxt->work_write, mtdoops_workfunc_write); |
431 | |
432 | register_mtd_user(&mtdoops_notifier); |
433 | return 0; |
434 | } |
435 | |
436 | static void __exit mtdoops_exit(void) |
437 | { |
438 | struct mtdoops_context *cxt = &oops_cxt; |
439 | |
440 | unregister_mtd_user(&mtdoops_notifier); |
441 | vfree(cxt->oops_buf); |
442 | vfree(cxt->oops_page_used); |
443 | } |
444 | |
445 | |
446 | module_init(mtdoops_init); |
447 | module_exit(mtdoops_exit); |
448 | |
449 | MODULE_LICENSE("GPL"); |
450 | MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>"); |
451 | MODULE_DESCRIPTION("MTD Oops/Panic console logger/driver"); |
452 |
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