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2b27bdcc | 1 | // SPDX-License-Identifier: GPL-2.0-only |
4b23aff0 RP |
2 | /* |
3 | * MTD Oops/Panic logger | |
4 | * | |
a1452a37 | 5 | * Copyright © 2007 Nokia Corporation. All rights reserved. |
4b23aff0 RP |
6 | * |
7 | * Author: Richard Purdie <rpurdie@openedhand.com> | |
4b23aff0 RP |
8 | */ |
9 | ||
10 | #include <linux/kernel.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/console.h> | |
13 | #include <linux/vmalloc.h> | |
14 | #include <linux/workqueue.h> | |
15 | #include <linux/sched.h> | |
16 | #include <linux/wait.h> | |
621e4f8e | 17 | #include <linux/delay.h> |
f9f7dd22 | 18 | #include <linux/interrupt.h> |
4b23aff0 | 19 | #include <linux/mtd/mtd.h> |
2e386e4b | 20 | #include <linux/kmsg_dump.h> |
4b23aff0 | 21 | |
1114e3d0 SK |
22 | /* Maximum MTD partition size */ |
23 | #define MTDOOPS_MAX_MTD_SIZE (8 * 1024 * 1024) | |
24 | ||
f0482ee3 | 25 | #define MTDOOPS_KERNMSG_MAGIC 0x5d005d00 |
2e386e4b | 26 | #define MTDOOPS_HEADER_SIZE 8 |
9507b0c8 SK |
27 | |
28 | static unsigned long record_size = 4096; | |
29 | module_param(record_size, ulong, 0400); | |
30 | MODULE_PARM_DESC(record_size, | |
31 | "record size for MTD OOPS pages in bytes (default 4096)"); | |
4b23aff0 | 32 | |
2e386e4b SK |
33 | static char mtddev[80]; |
34 | module_param_string(mtddev, mtddev, 80, 0400); | |
35 | MODULE_PARM_DESC(mtddev, | |
36 | "name or index number of the MTD device to use"); | |
37 | ||
38 | static int dump_oops = 1; | |
39 | module_param(dump_oops, int, 0600); | |
40 | MODULE_PARM_DESC(dump_oops, | |
41 | "set to 1 to dump oopses, 0 to only dump panics (default 1)"); | |
42 | ||
7903cbab | 43 | static struct mtdoops_context { |
2e386e4b SK |
44 | struct kmsg_dumper dump; |
45 | ||
4b23aff0 | 46 | int mtd_index; |
6ce0a856 RP |
47 | struct work_struct work_erase; |
48 | struct work_struct work_write; | |
4b23aff0 RP |
49 | struct mtd_info *mtd; |
50 | int oops_pages; | |
51 | int nextpage; | |
52 | int nextcount; | |
be95745f | 53 | unsigned long *oops_page_used; |
4b23aff0 RP |
54 | |
55 | void *oops_buf; | |
4b23aff0 RP |
56 | } oops_cxt; |
57 | ||
be95745f SK |
58 | static void mark_page_used(struct mtdoops_context *cxt, int page) |
59 | { | |
60 | set_bit(page, cxt->oops_page_used); | |
61 | } | |
62 | ||
63 | static void mark_page_unused(struct mtdoops_context *cxt, int page) | |
64 | { | |
65 | clear_bit(page, cxt->oops_page_used); | |
66 | } | |
67 | ||
68 | static int page_is_used(struct mtdoops_context *cxt, int page) | |
69 | { | |
70 | return test_bit(page, cxt->oops_page_used); | |
71 | } | |
72 | ||
be95745f | 73 | static int mtdoops_erase_block(struct mtdoops_context *cxt, int offset) |
4b23aff0 | 74 | { |
be95745f SK |
75 | struct mtd_info *mtd = cxt->mtd; |
76 | u32 start_page_offset = mtd_div_by_eb(offset, mtd) * mtd->erasesize; | |
9507b0c8 SK |
77 | u32 start_page = start_page_offset / record_size; |
78 | u32 erase_pages = mtd->erasesize / record_size; | |
4b23aff0 | 79 | struct erase_info erase; |
4b23aff0 | 80 | int ret; |
be95745f | 81 | int page; |
4b23aff0 | 82 | |
4b23aff0 | 83 | erase.addr = offset; |
79dcd8e9 | 84 | erase.len = mtd->erasesize; |
4b23aff0 | 85 | |
7e1f0dc0 | 86 | ret = mtd_erase(mtd, &erase); |
4b23aff0 | 87 | if (ret) { |
a15b124f AB |
88 | printk(KERN_WARNING "mtdoops: erase of region [0x%llx, 0x%llx] on \"%s\" failed\n", |
89 | (unsigned long long)erase.addr, | |
2e386e4b | 90 | (unsigned long long)erase.len, mtddev); |
4b23aff0 RP |
91 | return ret; |
92 | } | |
93 | ||
be95745f SK |
94 | /* Mark pages as unused */ |
95 | for (page = start_page; page < start_page + erase_pages; page++) | |
96 | mark_page_unused(cxt, page); | |
97 | ||
4b23aff0 RP |
98 | return 0; |
99 | } | |
100 | ||
6ce0a856 | 101 | static void mtdoops_inc_counter(struct mtdoops_context *cxt) |
4b23aff0 | 102 | { |
4b23aff0 | 103 | cxt->nextpage++; |
ecd5b310 | 104 | if (cxt->nextpage >= cxt->oops_pages) |
4b23aff0 RP |
105 | cxt->nextpage = 0; |
106 | cxt->nextcount++; | |
107 | if (cxt->nextcount == 0xffffffff) | |
108 | cxt->nextcount = 0; | |
109 | ||
be95745f | 110 | if (page_is_used(cxt, cxt->nextpage)) { |
6ce0a856 RP |
111 | schedule_work(&cxt->work_erase); |
112 | return; | |
113 | } | |
4b23aff0 | 114 | |
a15b124f AB |
115 | printk(KERN_DEBUG "mtdoops: ready %d, %d (no erase)\n", |
116 | cxt->nextpage, cxt->nextcount); | |
4b23aff0 RP |
117 | } |
118 | ||
6ce0a856 RP |
119 | /* Scheduled work - when we can't proceed without erasing a block */ |
120 | static void mtdoops_workfunc_erase(struct work_struct *work) | |
4b23aff0 | 121 | { |
6ce0a856 RP |
122 | struct mtdoops_context *cxt = |
123 | container_of(work, struct mtdoops_context, work_erase); | |
4b23aff0 RP |
124 | struct mtd_info *mtd = cxt->mtd; |
125 | int i = 0, j, ret, mod; | |
126 | ||
127 | /* We were unregistered */ | |
128 | if (!mtd) | |
129 | return; | |
130 | ||
9507b0c8 | 131 | mod = (cxt->nextpage * record_size) % mtd->erasesize; |
4b23aff0 | 132 | if (mod != 0) { |
9507b0c8 | 133 | cxt->nextpage = cxt->nextpage + ((mtd->erasesize - mod) / record_size); |
ecd5b310 | 134 | if (cxt->nextpage >= cxt->oops_pages) |
4b23aff0 RP |
135 | cxt->nextpage = 0; |
136 | } | |
137 | ||
9cb93fbb | 138 | while ((ret = mtd_block_isbad(mtd, cxt->nextpage * record_size)) > 0) { |
4b23aff0 | 139 | badblock: |
9507b0c8 SK |
140 | printk(KERN_WARNING "mtdoops: bad block at %08lx\n", |
141 | cxt->nextpage * record_size); | |
4b23aff0 | 142 | i++; |
9507b0c8 | 143 | cxt->nextpage = cxt->nextpage + (mtd->erasesize / record_size); |
ecd5b310 | 144 | if (cxt->nextpage >= cxt->oops_pages) |
4b23aff0 | 145 | cxt->nextpage = 0; |
9507b0c8 | 146 | if (i == cxt->oops_pages / (mtd->erasesize / record_size)) { |
a15b124f | 147 | printk(KERN_ERR "mtdoops: all blocks bad!\n"); |
4b23aff0 RP |
148 | return; |
149 | } | |
150 | } | |
151 | ||
9cb93fbb BN |
152 | if (ret < 0) { |
153 | printk(KERN_ERR "mtdoops: mtd_block_isbad failed, aborting\n"); | |
154 | return; | |
155 | } | |
156 | ||
4b23aff0 | 157 | for (j = 0, ret = -1; (j < 3) && (ret < 0); j++) |
9507b0c8 | 158 | ret = mtdoops_erase_block(cxt, cxt->nextpage * record_size); |
4b23aff0 | 159 | |
2986bd2a | 160 | if (ret >= 0) { |
a15b124f AB |
161 | printk(KERN_DEBUG "mtdoops: ready %d, %d\n", |
162 | cxt->nextpage, cxt->nextcount); | |
2986bd2a | 163 | return; |
4b23aff0 RP |
164 | } |
165 | ||
bb4a0986 | 166 | if (ret == -EIO) { |
5942ddbc | 167 | ret = mtd_block_markbad(mtd, cxt->nextpage * record_size); |
bb4a0986 | 168 | if (ret < 0 && ret != -EOPNOTSUPP) { |
a15b124f | 169 | printk(KERN_ERR "mtdoops: block_markbad failed, aborting\n"); |
2986bd2a RP |
170 | return; |
171 | } | |
172 | } | |
173 | goto badblock; | |
4b23aff0 RP |
174 | } |
175 | ||
621e4f8e | 176 | static void mtdoops_write(struct mtdoops_context *cxt, int panic) |
4b23aff0 | 177 | { |
6ce0a856 RP |
178 | struct mtd_info *mtd = cxt->mtd; |
179 | size_t retlen; | |
2e386e4b | 180 | u32 *hdr; |
6ce0a856 | 181 | int ret; |
4b23aff0 | 182 | |
2e386e4b SK |
183 | /* Add mtdoops header to the buffer */ |
184 | hdr = cxt->oops_buf; | |
185 | hdr[0] = cxt->nextcount; | |
186 | hdr[1] = MTDOOPS_KERNMSG_MAGIC; | |
6ce0a856 | 187 | |
016c1291 | 188 | if (panic) { |
7ae79d7f AB |
189 | ret = mtd_panic_write(mtd, cxt->nextpage * record_size, |
190 | record_size, &retlen, cxt->oops_buf); | |
016c1291 AB |
191 | if (ret == -EOPNOTSUPP) { |
192 | printk(KERN_ERR "mtdoops: Cannot write from panic without panic_write\n"); | |
193 | return; | |
194 | } | |
195 | } else | |
eda95cbf AB |
196 | ret = mtd_write(mtd, cxt->nextpage * record_size, |
197 | record_size, &retlen, cxt->oops_buf); | |
6ce0a856 | 198 | |
9507b0c8 SK |
199 | if (retlen != record_size || ret < 0) |
200 | printk(KERN_ERR "mtdoops: write failure at %ld (%td of %ld written), error %d\n", | |
201 | cxt->nextpage * record_size, retlen, record_size, ret); | |
be95745f | 202 | mark_page_used(cxt, cxt->nextpage); |
2e386e4b | 203 | memset(cxt->oops_buf, 0xff, record_size); |
6ce0a856 RP |
204 | |
205 | mtdoops_inc_counter(cxt); | |
621e4f8e RP |
206 | } |
207 | ||
621e4f8e RP |
208 | static void mtdoops_workfunc_write(struct work_struct *work) |
209 | { | |
210 | struct mtdoops_context *cxt = | |
211 | container_of(work, struct mtdoops_context, work_write); | |
212 | ||
213 | mtdoops_write(cxt, 0); | |
a15b124f | 214 | } |
4b23aff0 | 215 | |
6ce0a856 | 216 | static void find_next_position(struct mtdoops_context *cxt) |
4b23aff0 RP |
217 | { |
218 | struct mtd_info *mtd = cxt->mtd; | |
2986bd2a | 219 | int ret, page, maxpos = 0; |
f0482ee3 | 220 | u32 count[2], maxcount = 0xffffffff; |
4b23aff0 RP |
221 | size_t retlen; |
222 | ||
223 | for (page = 0; page < cxt->oops_pages; page++) { | |
bb4a0986 | 224 | if (mtd_block_isbad(mtd, page * record_size)) |
3538c563 | 225 | continue; |
be95745f SK |
226 | /* Assume the page is used */ |
227 | mark_page_used(cxt, page); | |
329ad399 AB |
228 | ret = mtd_read(mtd, page * record_size, MTDOOPS_HEADER_SIZE, |
229 | &retlen, (u_char *)&count[0]); | |
2e386e4b | 230 | if (retlen != MTDOOPS_HEADER_SIZE || |
d57f4054 | 231 | (ret < 0 && !mtd_is_bitflip(ret))) { |
2e386e4b SK |
232 | printk(KERN_ERR "mtdoops: read failure at %ld (%td of %d read), err %d\n", |
233 | page * record_size, retlen, | |
234 | MTDOOPS_HEADER_SIZE, ret); | |
2986bd2a RP |
235 | continue; |
236 | } | |
237 | ||
be95745f SK |
238 | if (count[0] == 0xffffffff && count[1] == 0xffffffff) |
239 | mark_page_unused(cxt, page); | |
cd409c61 | 240 | if (count[0] == 0xffffffff || count[1] != MTDOOPS_KERNMSG_MAGIC) |
4b23aff0 RP |
241 | continue; |
242 | if (maxcount == 0xffffffff) { | |
f0482ee3 | 243 | maxcount = count[0]; |
4b23aff0 | 244 | maxpos = page; |
a15b124f | 245 | } else if (count[0] < 0x40000000 && maxcount > 0xc0000000) { |
f0482ee3 | 246 | maxcount = count[0]; |
4b23aff0 | 247 | maxpos = page; |
a15b124f | 248 | } else if (count[0] > maxcount && count[0] < 0xc0000000) { |
f0482ee3 | 249 | maxcount = count[0]; |
4b23aff0 | 250 | maxpos = page; |
a15b124f AB |
251 | } else if (count[0] > maxcount && count[0] > 0xc0000000 |
252 | && maxcount > 0x80000000) { | |
f0482ee3 | 253 | maxcount = count[0]; |
4b23aff0 RP |
254 | maxpos = page; |
255 | } | |
256 | } | |
257 | if (maxcount == 0xffffffff) { | |
cd409c61 MC |
258 | cxt->nextpage = cxt->oops_pages - 1; |
259 | cxt->nextcount = 0; | |
260 | } | |
261 | else { | |
262 | cxt->nextpage = maxpos; | |
263 | cxt->nextcount = maxcount; | |
4b23aff0 | 264 | } |
4b23aff0 | 265 | |
6ce0a856 | 266 | mtdoops_inc_counter(cxt); |
4b23aff0 RP |
267 | } |
268 | ||
2e386e4b | 269 | static void mtdoops_do_dump(struct kmsg_dumper *dumper, |
e2ae715d | 270 | enum kmsg_dump_reason reason) |
2e386e4b SK |
271 | { |
272 | struct mtdoops_context *cxt = container_of(dumper, | |
273 | struct mtdoops_context, dump); | |
fc2d557c | 274 | |
2e386e4b SK |
275 | /* Only dump oopses if dump_oops is set */ |
276 | if (reason == KMSG_DUMP_OOPS && !dump_oops) | |
277 | return; | |
278 | ||
e2ae715d KS |
279 | kmsg_dump_get_buffer(dumper, true, cxt->oops_buf + MTDOOPS_HEADER_SIZE, |
280 | record_size - MTDOOPS_HEADER_SIZE, NULL); | |
2e386e4b SK |
281 | |
282 | /* Panics must be written immediately */ | |
016c1291 AB |
283 | if (reason != KMSG_DUMP_OOPS) |
284 | mtdoops_write(cxt, 1); | |
2e386e4b SK |
285 | |
286 | /* For other cases, schedule work to write it "nicely" */ | |
287 | schedule_work(&cxt->work_write); | |
288 | } | |
4b23aff0 RP |
289 | |
290 | static void mtdoops_notify_add(struct mtd_info *mtd) | |
291 | { | |
292 | struct mtdoops_context *cxt = &oops_cxt; | |
2e386e4b SK |
293 | u64 mtdoops_pages = div_u64(mtd->size, record_size); |
294 | int err; | |
4b23aff0 | 295 | |
2e386e4b | 296 | if (!strcmp(mtd->name, mtddev)) |
e2a0f25b AH |
297 | cxt->mtd_index = mtd->index; |
298 | ||
a15b124f | 299 | if (mtd->index != cxt->mtd_index || cxt->mtd_index < 0) |
4b23aff0 RP |
300 | return; |
301 | ||
a15b124f AB |
302 | if (mtd->size < mtd->erasesize * 2) { |
303 | printk(KERN_ERR "mtdoops: MTD partition %d not big enough for mtdoops\n", | |
304 | mtd->index); | |
4b23aff0 RP |
305 | return; |
306 | } | |
9507b0c8 | 307 | if (mtd->erasesize < record_size) { |
a15b124f AB |
308 | printk(KERN_ERR "mtdoops: eraseblock size of MTD partition %d too small\n", |
309 | mtd->index); | |
79dcd8e9 RP |
310 | return; |
311 | } | |
1114e3d0 SK |
312 | if (mtd->size > MTDOOPS_MAX_MTD_SIZE) { |
313 | printk(KERN_ERR "mtdoops: mtd%d is too large (limit is %d MiB)\n", | |
314 | mtd->index, MTDOOPS_MAX_MTD_SIZE / 1024 / 1024); | |
315 | return; | |
316 | } | |
317 | ||
be95745f | 318 | /* oops_page_used is a bit field */ |
42bc47b3 KC |
319 | cxt->oops_page_used = |
320 | vmalloc(array_size(sizeof(unsigned long), | |
321 | DIV_ROUND_UP(mtdoops_pages, | |
322 | BITS_PER_LONG))); | |
be95745f | 323 | if (!cxt->oops_page_used) { |
2e386e4b SK |
324 | printk(KERN_ERR "mtdoops: could not allocate page array\n"); |
325 | return; | |
326 | } | |
327 | ||
e2ae715d | 328 | cxt->dump.max_reason = KMSG_DUMP_OOPS; |
2e386e4b SK |
329 | cxt->dump.dump = mtdoops_do_dump; |
330 | err = kmsg_dump_register(&cxt->dump); | |
331 | if (err) { | |
332 | printk(KERN_ERR "mtdoops: registering kmsg dumper failed, error %d\n", err); | |
333 | vfree(cxt->oops_page_used); | |
334 | cxt->oops_page_used = NULL; | |
be95745f SK |
335 | return; |
336 | } | |
4b23aff0 | 337 | |
1114e3d0 | 338 | cxt->mtd = mtd; |
9507b0c8 | 339 | cxt->oops_pages = (int)mtd->size / record_size; |
6ce0a856 | 340 | find_next_position(cxt); |
79dcd8e9 | 341 | printk(KERN_INFO "mtdoops: Attached to MTD device %d\n", mtd->index); |
4b23aff0 RP |
342 | } |
343 | ||
344 | static void mtdoops_notify_remove(struct mtd_info *mtd) | |
345 | { | |
346 | struct mtdoops_context *cxt = &oops_cxt; | |
347 | ||
a15b124f | 348 | if (mtd->index != cxt->mtd_index || cxt->mtd_index < 0) |
4b23aff0 RP |
349 | return; |
350 | ||
2e386e4b SK |
351 | if (kmsg_dump_unregister(&cxt->dump) < 0) |
352 | printk(KERN_WARNING "mtdoops: could not unregister kmsg_dumper\n"); | |
353 | ||
4b23aff0 | 354 | cxt->mtd = NULL; |
43829731 TH |
355 | flush_work(&cxt->work_erase); |
356 | flush_work(&cxt->work_write); | |
4b23aff0 RP |
357 | } |
358 | ||
4b23aff0 RP |
359 | |
360 | static struct mtd_notifier mtdoops_notifier = { | |
361 | .add = mtdoops_notify_add, | |
362 | .remove = mtdoops_notify_remove, | |
363 | }; | |
364 | ||
2e386e4b | 365 | static int __init mtdoops_init(void) |
4b23aff0 RP |
366 | { |
367 | struct mtdoops_context *cxt = &oops_cxt; | |
2e386e4b SK |
368 | int mtd_index; |
369 | char *endp; | |
4b23aff0 | 370 | |
2e386e4b SK |
371 | if (strlen(mtddev) == 0) { |
372 | printk(KERN_ERR "mtdoops: mtd device (mtddev=name/number) must be supplied\n"); | |
373 | return -EINVAL; | |
374 | } | |
9507b0c8 SK |
375 | if ((record_size & 4095) != 0) { |
376 | printk(KERN_ERR "mtdoops: record_size must be a multiple of 4096\n"); | |
377 | return -EINVAL; | |
378 | } | |
379 | if (record_size < 4096) { | |
380 | printk(KERN_ERR "mtdoops: record_size must be over 4096 bytes\n"); | |
381 | return -EINVAL; | |
382 | } | |
2e386e4b SK |
383 | |
384 | /* Setup the MTD device to use */ | |
4b23aff0 | 385 | cxt->mtd_index = -1; |
2e386e4b SK |
386 | mtd_index = simple_strtoul(mtddev, &endp, 0); |
387 | if (*endp == '\0') | |
388 | cxt->mtd_index = mtd_index; | |
2e386e4b | 389 | |
9507b0c8 | 390 | cxt->oops_buf = vmalloc(record_size); |
4b23aff0 | 391 | if (!cxt->oops_buf) { |
a15b124f | 392 | printk(KERN_ERR "mtdoops: failed to allocate buffer workspace\n"); |
4b23aff0 RP |
393 | return -ENOMEM; |
394 | } | |
2e386e4b | 395 | memset(cxt->oops_buf, 0xff, record_size); |
4b23aff0 | 396 | |
6ce0a856 RP |
397 | INIT_WORK(&cxt->work_erase, mtdoops_workfunc_erase); |
398 | INIT_WORK(&cxt->work_write, mtdoops_workfunc_write); | |
4b23aff0 | 399 | |
4b23aff0 RP |
400 | register_mtd_user(&mtdoops_notifier); |
401 | return 0; | |
402 | } | |
403 | ||
2e386e4b | 404 | static void __exit mtdoops_exit(void) |
4b23aff0 RP |
405 | { |
406 | struct mtdoops_context *cxt = &oops_cxt; | |
407 | ||
408 | unregister_mtd_user(&mtdoops_notifier); | |
4b23aff0 | 409 | vfree(cxt->oops_buf); |
be95745f | 410 | vfree(cxt->oops_page_used); |
4b23aff0 RP |
411 | } |
412 | ||
413 | ||
2e386e4b SK |
414 | module_init(mtdoops_init); |
415 | module_exit(mtdoops_exit); | |
4b23aff0 RP |
416 | |
417 | MODULE_LICENSE("GPL"); | |
418 | MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>"); | |
419 | MODULE_DESCRIPTION("MTD Oops/Panic console logger/driver"); |