Commit | Line | Data |
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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 | ||
43cfba56 RZ |
10 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
11 | ||
4b23aff0 RP |
12 | #include <linux/kernel.h> |
13 | #include <linux/module.h> | |
14 | #include <linux/console.h> | |
15 | #include <linux/vmalloc.h> | |
16 | #include <linux/workqueue.h> | |
17 | #include <linux/sched.h> | |
18 | #include <linux/wait.h> | |
621e4f8e | 19 | #include <linux/delay.h> |
f9f7dd22 | 20 | #include <linux/interrupt.h> |
aa641a22 | 21 | #include <linux/timekeeping.h> |
4b23aff0 | 22 | #include <linux/mtd/mtd.h> |
2e386e4b | 23 | #include <linux/kmsg_dump.h> |
4b23aff0 | 24 | |
1114e3d0 SK |
25 | /* Maximum MTD partition size */ |
26 | #define MTDOOPS_MAX_MTD_SIZE (8 * 1024 * 1024) | |
27 | ||
9507b0c8 SK |
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 | ||
aa641a22 JME |
43 | #define MTDOOPS_KERNMSG_MAGIC_v1 0x5d005d00 /* Original */ |
44 | #define MTDOOPS_KERNMSG_MAGIC_v2 0x5d005e00 /* Adds the timestamp */ | |
0bd359ee JME |
45 | |
46 | struct mtdoops_hdr { | |
47 | u32 seq; | |
48 | u32 magic; | |
aa641a22 | 49 | ktime_t timestamp; |
0bd359ee JME |
50 | } __packed; |
51 | ||
7903cbab | 52 | static struct mtdoops_context { |
2e386e4b SK |
53 | struct kmsg_dumper dump; |
54 | ||
4b23aff0 | 55 | int mtd_index; |
6ce0a856 RP |
56 | struct work_struct work_erase; |
57 | struct work_struct work_write; | |
4b23aff0 RP |
58 | struct mtd_info *mtd; |
59 | int oops_pages; | |
60 | int nextpage; | |
61 | int nextcount; | |
be95745f | 62 | unsigned long *oops_page_used; |
4b23aff0 | 63 | |
40ddbbac | 64 | unsigned long oops_buf_busy; |
4b23aff0 | 65 | void *oops_buf; |
4b23aff0 RP |
66 | } oops_cxt; |
67 | ||
be95745f SK |
68 | static void mark_page_used(struct mtdoops_context *cxt, int page) |
69 | { | |
70 | set_bit(page, cxt->oops_page_used); | |
71 | } | |
72 | ||
73 | static void mark_page_unused(struct mtdoops_context *cxt, int page) | |
74 | { | |
75 | clear_bit(page, cxt->oops_page_used); | |
76 | } | |
77 | ||
78 | static int page_is_used(struct mtdoops_context *cxt, int page) | |
79 | { | |
80 | return test_bit(page, cxt->oops_page_used); | |
81 | } | |
82 | ||
be95745f | 83 | static int mtdoops_erase_block(struct mtdoops_context *cxt, int offset) |
4b23aff0 | 84 | { |
be95745f SK |
85 | struct mtd_info *mtd = cxt->mtd; |
86 | u32 start_page_offset = mtd_div_by_eb(offset, mtd) * mtd->erasesize; | |
9507b0c8 SK |
87 | u32 start_page = start_page_offset / record_size; |
88 | u32 erase_pages = mtd->erasesize / record_size; | |
4b23aff0 | 89 | struct erase_info erase; |
4b23aff0 | 90 | int ret; |
be95745f | 91 | int page; |
4b23aff0 | 92 | |
4b23aff0 | 93 | erase.addr = offset; |
79dcd8e9 | 94 | erase.len = mtd->erasesize; |
4b23aff0 | 95 | |
7e1f0dc0 | 96 | ret = mtd_erase(mtd, &erase); |
4b23aff0 | 97 | if (ret) { |
43cfba56 RZ |
98 | pr_warn("erase of region [0x%llx, 0x%llx] on \"%s\" failed\n", |
99 | (unsigned long long)erase.addr, | |
100 | (unsigned long long)erase.len, mtddev); | |
4b23aff0 RP |
101 | return ret; |
102 | } | |
103 | ||
be95745f SK |
104 | /* Mark pages as unused */ |
105 | for (page = start_page; page < start_page + erase_pages; page++) | |
106 | mark_page_unused(cxt, page); | |
107 | ||
4b23aff0 RP |
108 | return 0; |
109 | } | |
110 | ||
340193e0 | 111 | static void mtdoops_erase(struct mtdoops_context *cxt) |
4b23aff0 RP |
112 | { |
113 | struct mtd_info *mtd = cxt->mtd; | |
114 | int i = 0, j, ret, mod; | |
115 | ||
116 | /* We were unregistered */ | |
117 | if (!mtd) | |
118 | return; | |
119 | ||
9507b0c8 | 120 | mod = (cxt->nextpage * record_size) % mtd->erasesize; |
4b23aff0 | 121 | if (mod != 0) { |
9507b0c8 | 122 | cxt->nextpage = cxt->nextpage + ((mtd->erasesize - mod) / record_size); |
ecd5b310 | 123 | if (cxt->nextpage >= cxt->oops_pages) |
4b23aff0 RP |
124 | cxt->nextpage = 0; |
125 | } | |
126 | ||
9cb93fbb | 127 | while ((ret = mtd_block_isbad(mtd, cxt->nextpage * record_size)) > 0) { |
4b23aff0 | 128 | badblock: |
43cfba56 RZ |
129 | pr_warn("bad block at %08lx\n", |
130 | cxt->nextpage * record_size); | |
4b23aff0 | 131 | i++; |
9507b0c8 | 132 | cxt->nextpage = cxt->nextpage + (mtd->erasesize / record_size); |
ecd5b310 | 133 | if (cxt->nextpage >= cxt->oops_pages) |
4b23aff0 | 134 | cxt->nextpage = 0; |
9507b0c8 | 135 | if (i == cxt->oops_pages / (mtd->erasesize / record_size)) { |
43cfba56 | 136 | pr_err("all blocks bad!\n"); |
4b23aff0 RP |
137 | return; |
138 | } | |
139 | } | |
140 | ||
9cb93fbb | 141 | if (ret < 0) { |
43cfba56 | 142 | pr_err("mtd_block_isbad failed, aborting\n"); |
9cb93fbb BN |
143 | return; |
144 | } | |
145 | ||
4b23aff0 | 146 | for (j = 0, ret = -1; (j < 3) && (ret < 0); j++) |
9507b0c8 | 147 | ret = mtdoops_erase_block(cxt, cxt->nextpage * record_size); |
4b23aff0 | 148 | |
2986bd2a | 149 | if (ret >= 0) { |
43cfba56 RZ |
150 | pr_debug("ready %d, %d\n", |
151 | cxt->nextpage, cxt->nextcount); | |
2986bd2a | 152 | return; |
4b23aff0 RP |
153 | } |
154 | ||
bb4a0986 | 155 | if (ret == -EIO) { |
5942ddbc | 156 | ret = mtd_block_markbad(mtd, cxt->nextpage * record_size); |
bb4a0986 | 157 | if (ret < 0 && ret != -EOPNOTSUPP) { |
43cfba56 | 158 | pr_err("block_markbad failed, aborting\n"); |
2986bd2a RP |
159 | return; |
160 | } | |
161 | } | |
162 | goto badblock; | |
4b23aff0 RP |
163 | } |
164 | ||
340193e0 RZ |
165 | /* Scheduled work - when we can't proceed without erasing a block */ |
166 | static void mtdoops_workfunc_erase(struct work_struct *work) | |
167 | { | |
168 | struct mtdoops_context *cxt = | |
169 | container_of(work, struct mtdoops_context, work_erase); | |
170 | mtdoops_erase(cxt); | |
171 | } | |
172 | ||
7cc84e0e | 173 | static void mtdoops_inc_counter(struct mtdoops_context *cxt, int panic) |
340193e0 RZ |
174 | { |
175 | cxt->nextpage++; | |
176 | if (cxt->nextpage >= cxt->oops_pages) | |
177 | cxt->nextpage = 0; | |
178 | cxt->nextcount++; | |
179 | if (cxt->nextcount == 0xffffffff) | |
180 | cxt->nextcount = 0; | |
181 | ||
182 | if (page_is_used(cxt, cxt->nextpage)) { | |
7cc84e0e RZ |
183 | pr_debug("not ready %d, %d (erase %s)\n", |
184 | cxt->nextpage, cxt->nextcount, | |
185 | panic ? "immediately" : "scheduled"); | |
186 | if (panic) { | |
187 | /* In case of panic, erase immediately */ | |
188 | mtdoops_erase(cxt); | |
189 | } else { | |
190 | /* Otherwise, schedule work to erase it "nicely" */ | |
191 | schedule_work(&cxt->work_erase); | |
192 | } | |
193 | } else { | |
194 | pr_debug("ready %d, %d (no erase)\n", | |
195 | cxt->nextpage, cxt->nextcount); | |
340193e0 | 196 | } |
340193e0 RZ |
197 | } |
198 | ||
621e4f8e | 199 | static void mtdoops_write(struct mtdoops_context *cxt, int panic) |
4b23aff0 | 200 | { |
6ce0a856 RP |
201 | struct mtd_info *mtd = cxt->mtd; |
202 | size_t retlen; | |
0bd359ee | 203 | struct mtdoops_hdr *hdr; |
6ce0a856 | 204 | int ret; |
4b23aff0 | 205 | |
40ddbbac JO |
206 | if (test_and_set_bit(0, &cxt->oops_buf_busy)) |
207 | return; | |
208 | ||
2e386e4b | 209 | /* Add mtdoops header to the buffer */ |
0bd359ee JME |
210 | hdr = (struct mtdoops_hdr *)cxt->oops_buf; |
211 | hdr->seq = cxt->nextcount; | |
aa641a22 JME |
212 | hdr->magic = MTDOOPS_KERNMSG_MAGIC_v2; |
213 | hdr->timestamp = ktime_get_real(); | |
6ce0a856 | 214 | |
016c1291 | 215 | if (panic) { |
7ae79d7f AB |
216 | ret = mtd_panic_write(mtd, cxt->nextpage * record_size, |
217 | record_size, &retlen, cxt->oops_buf); | |
016c1291 | 218 | if (ret == -EOPNOTSUPP) { |
43cfba56 | 219 | pr_err("Cannot write from panic without panic_write\n"); |
40ddbbac | 220 | goto out; |
016c1291 AB |
221 | } |
222 | } else | |
eda95cbf AB |
223 | ret = mtd_write(mtd, cxt->nextpage * record_size, |
224 | record_size, &retlen, cxt->oops_buf); | |
6ce0a856 | 225 | |
9507b0c8 | 226 | if (retlen != record_size || ret < 0) |
43cfba56 | 227 | pr_err("write failure at %ld (%td of %ld written), error %d\n", |
9507b0c8 | 228 | cxt->nextpage * record_size, retlen, record_size, ret); |
be95745f | 229 | mark_page_used(cxt, cxt->nextpage); |
2e386e4b | 230 | memset(cxt->oops_buf, 0xff, record_size); |
6ce0a856 | 231 | |
7cc84e0e | 232 | mtdoops_inc_counter(cxt, panic); |
40ddbbac JO |
233 | out: |
234 | clear_bit(0, &cxt->oops_buf_busy); | |
621e4f8e RP |
235 | } |
236 | ||
621e4f8e RP |
237 | static void mtdoops_workfunc_write(struct work_struct *work) |
238 | { | |
239 | struct mtdoops_context *cxt = | |
240 | container_of(work, struct mtdoops_context, work_write); | |
241 | ||
242 | mtdoops_write(cxt, 0); | |
a15b124f | 243 | } |
4b23aff0 | 244 | |
6ce0a856 | 245 | static void find_next_position(struct mtdoops_context *cxt) |
4b23aff0 RP |
246 | { |
247 | struct mtd_info *mtd = cxt->mtd; | |
0bd359ee | 248 | struct mtdoops_hdr hdr; |
2986bd2a | 249 | int ret, page, maxpos = 0; |
0bd359ee | 250 | u32 maxcount = 0xffffffff; |
4b23aff0 RP |
251 | size_t retlen; |
252 | ||
253 | for (page = 0; page < cxt->oops_pages; page++) { | |
bb4a0986 | 254 | if (mtd_block_isbad(mtd, page * record_size)) |
3538c563 | 255 | continue; |
be95745f SK |
256 | /* Assume the page is used */ |
257 | mark_page_used(cxt, page); | |
0bd359ee JME |
258 | ret = mtd_read(mtd, page * record_size, sizeof(hdr), |
259 | &retlen, (u_char *)&hdr); | |
260 | if (retlen != sizeof(hdr) || | |
d57f4054 | 261 | (ret < 0 && !mtd_is_bitflip(ret))) { |
43cfba56 | 262 | pr_err("read failure at %ld (%zu of %zu read), err %d\n", |
0bd359ee | 263 | page * record_size, retlen, sizeof(hdr), ret); |
2986bd2a RP |
264 | continue; |
265 | } | |
266 | ||
0bd359ee | 267 | if (hdr.seq == 0xffffffff && hdr.magic == 0xffffffff) |
be95745f | 268 | mark_page_unused(cxt, page); |
aa641a22 JME |
269 | if (hdr.seq == 0xffffffff || |
270 | (hdr.magic != MTDOOPS_KERNMSG_MAGIC_v1 && | |
271 | hdr.magic != MTDOOPS_KERNMSG_MAGIC_v2)) | |
4b23aff0 RP |
272 | continue; |
273 | if (maxcount == 0xffffffff) { | |
0bd359ee | 274 | maxcount = hdr.seq; |
4b23aff0 | 275 | maxpos = page; |
0bd359ee JME |
276 | } else if (hdr.seq < 0x40000000 && maxcount > 0xc0000000) { |
277 | maxcount = hdr.seq; | |
4b23aff0 | 278 | maxpos = page; |
0bd359ee JME |
279 | } else if (hdr.seq > maxcount && hdr.seq < 0xc0000000) { |
280 | maxcount = hdr.seq; | |
4b23aff0 | 281 | maxpos = page; |
0bd359ee | 282 | } else if (hdr.seq > maxcount && hdr.seq > 0xc0000000 |
a15b124f | 283 | && maxcount > 0x80000000) { |
0bd359ee | 284 | maxcount = hdr.seq; |
4b23aff0 RP |
285 | maxpos = page; |
286 | } | |
287 | } | |
288 | if (maxcount == 0xffffffff) { | |
cd409c61 MC |
289 | cxt->nextpage = cxt->oops_pages - 1; |
290 | cxt->nextcount = 0; | |
291 | } | |
292 | else { | |
293 | cxt->nextpage = maxpos; | |
294 | cxt->nextcount = maxcount; | |
4b23aff0 | 295 | } |
4b23aff0 | 296 | |
7cc84e0e | 297 | mtdoops_inc_counter(cxt, 0); |
4b23aff0 RP |
298 | } |
299 | ||
2e386e4b | 300 | static void mtdoops_do_dump(struct kmsg_dumper *dumper, |
e2ae715d | 301 | enum kmsg_dump_reason reason) |
2e386e4b SK |
302 | { |
303 | struct mtdoops_context *cxt = container_of(dumper, | |
304 | struct mtdoops_context, dump); | |
f9f3f02d | 305 | struct kmsg_dump_iter iter; |
fc2d557c | 306 | |
2e386e4b SK |
307 | /* Only dump oopses if dump_oops is set */ |
308 | if (reason == KMSG_DUMP_OOPS && !dump_oops) | |
309 | return; | |
310 | ||
f9f3f02d JO |
311 | kmsg_dump_rewind(&iter); |
312 | ||
40ddbbac JO |
313 | if (test_and_set_bit(0, &cxt->oops_buf_busy)) |
314 | return; | |
0bd359ee JME |
315 | kmsg_dump_get_buffer(&iter, true, |
316 | cxt->oops_buf + sizeof(struct mtdoops_hdr), | |
317 | record_size - sizeof(struct mtdoops_hdr), NULL); | |
40ddbbac | 318 | clear_bit(0, &cxt->oops_buf_busy); |
2e386e4b | 319 | |
c1cf1d57 MT |
320 | if (reason != KMSG_DUMP_OOPS) { |
321 | /* Panics must be written immediately */ | |
016c1291 | 322 | mtdoops_write(cxt, 1); |
c1cf1d57 MT |
323 | } else { |
324 | /* For other cases, schedule work to write it "nicely" */ | |
325 | schedule_work(&cxt->work_write); | |
326 | } | |
2e386e4b | 327 | } |
4b23aff0 RP |
328 | |
329 | static void mtdoops_notify_add(struct mtd_info *mtd) | |
330 | { | |
331 | struct mtdoops_context *cxt = &oops_cxt; | |
2e386e4b SK |
332 | u64 mtdoops_pages = div_u64(mtd->size, record_size); |
333 | int err; | |
4b23aff0 | 334 | |
2e386e4b | 335 | if (!strcmp(mtd->name, mtddev)) |
e2a0f25b AH |
336 | cxt->mtd_index = mtd->index; |
337 | ||
a15b124f | 338 | if (mtd->index != cxt->mtd_index || cxt->mtd_index < 0) |
4b23aff0 RP |
339 | return; |
340 | ||
a15b124f | 341 | if (mtd->size < mtd->erasesize * 2) { |
43cfba56 | 342 | pr_err("MTD partition %d not big enough for mtdoops\n", |
a15b124f | 343 | mtd->index); |
4b23aff0 RP |
344 | return; |
345 | } | |
9507b0c8 | 346 | if (mtd->erasesize < record_size) { |
43cfba56 | 347 | pr_err("eraseblock size of MTD partition %d too small\n", |
a15b124f | 348 | mtd->index); |
79dcd8e9 RP |
349 | return; |
350 | } | |
1114e3d0 | 351 | if (mtd->size > MTDOOPS_MAX_MTD_SIZE) { |
43cfba56 | 352 | pr_err("mtd%d is too large (limit is %d MiB)\n", |
1114e3d0 SK |
353 | mtd->index, MTDOOPS_MAX_MTD_SIZE / 1024 / 1024); |
354 | return; | |
355 | } | |
356 | ||
be95745f | 357 | /* oops_page_used is a bit field */ |
42bc47b3 KC |
358 | cxt->oops_page_used = |
359 | vmalloc(array_size(sizeof(unsigned long), | |
360 | DIV_ROUND_UP(mtdoops_pages, | |
361 | BITS_PER_LONG))); | |
be95745f | 362 | if (!cxt->oops_page_used) { |
43cfba56 | 363 | pr_err("could not allocate page array\n"); |
2e386e4b SK |
364 | return; |
365 | } | |
366 | ||
e2ae715d | 367 | cxt->dump.max_reason = KMSG_DUMP_OOPS; |
2e386e4b SK |
368 | cxt->dump.dump = mtdoops_do_dump; |
369 | err = kmsg_dump_register(&cxt->dump); | |
370 | if (err) { | |
43cfba56 | 371 | pr_err("registering kmsg dumper failed, error %d\n", err); |
2e386e4b SK |
372 | vfree(cxt->oops_page_used); |
373 | cxt->oops_page_used = NULL; | |
be95745f SK |
374 | return; |
375 | } | |
4b23aff0 | 376 | |
1114e3d0 | 377 | cxt->mtd = mtd; |
9507b0c8 | 378 | cxt->oops_pages = (int)mtd->size / record_size; |
6ce0a856 | 379 | find_next_position(cxt); |
43cfba56 | 380 | pr_info("Attached to MTD device %d\n", mtd->index); |
4b23aff0 RP |
381 | } |
382 | ||
383 | static void mtdoops_notify_remove(struct mtd_info *mtd) | |
384 | { | |
385 | struct mtdoops_context *cxt = &oops_cxt; | |
386 | ||
a15b124f | 387 | if (mtd->index != cxt->mtd_index || cxt->mtd_index < 0) |
4b23aff0 RP |
388 | return; |
389 | ||
2e386e4b | 390 | if (kmsg_dump_unregister(&cxt->dump) < 0) |
43cfba56 | 391 | pr_warn("could not unregister kmsg_dumper\n"); |
2e386e4b | 392 | |
4b23aff0 | 393 | cxt->mtd = NULL; |
43829731 TH |
394 | flush_work(&cxt->work_erase); |
395 | flush_work(&cxt->work_write); | |
4b23aff0 RP |
396 | } |
397 | ||
4b23aff0 RP |
398 | |
399 | static struct mtd_notifier mtdoops_notifier = { | |
400 | .add = mtdoops_notify_add, | |
401 | .remove = mtdoops_notify_remove, | |
402 | }; | |
403 | ||
2e386e4b | 404 | static int __init mtdoops_init(void) |
4b23aff0 RP |
405 | { |
406 | struct mtdoops_context *cxt = &oops_cxt; | |
2e386e4b SK |
407 | int mtd_index; |
408 | char *endp; | |
4b23aff0 | 409 | |
2e386e4b | 410 | if (strlen(mtddev) == 0) { |
43cfba56 | 411 | pr_err("mtd device (mtddev=name/number) must be supplied\n"); |
2e386e4b SK |
412 | return -EINVAL; |
413 | } | |
9507b0c8 | 414 | if ((record_size & 4095) != 0) { |
43cfba56 | 415 | pr_err("record_size must be a multiple of 4096\n"); |
9507b0c8 SK |
416 | return -EINVAL; |
417 | } | |
418 | if (record_size < 4096) { | |
43cfba56 | 419 | pr_err("record_size must be over 4096 bytes\n"); |
9507b0c8 SK |
420 | return -EINVAL; |
421 | } | |
2e386e4b SK |
422 | |
423 | /* Setup the MTD device to use */ | |
4b23aff0 | 424 | cxt->mtd_index = -1; |
2e386e4b SK |
425 | mtd_index = simple_strtoul(mtddev, &endp, 0); |
426 | if (*endp == '\0') | |
427 | cxt->mtd_index = mtd_index; | |
2e386e4b | 428 | |
9507b0c8 | 429 | cxt->oops_buf = vmalloc(record_size); |
313ea21a | 430 | if (!cxt->oops_buf) |
4b23aff0 | 431 | return -ENOMEM; |
2e386e4b | 432 | memset(cxt->oops_buf, 0xff, record_size); |
40ddbbac | 433 | cxt->oops_buf_busy = 0; |
4b23aff0 | 434 | |
6ce0a856 RP |
435 | INIT_WORK(&cxt->work_erase, mtdoops_workfunc_erase); |
436 | INIT_WORK(&cxt->work_write, mtdoops_workfunc_write); | |
4b23aff0 | 437 | |
4b23aff0 RP |
438 | register_mtd_user(&mtdoops_notifier); |
439 | return 0; | |
440 | } | |
441 | ||
2e386e4b | 442 | static void __exit mtdoops_exit(void) |
4b23aff0 RP |
443 | { |
444 | struct mtdoops_context *cxt = &oops_cxt; | |
445 | ||
446 | unregister_mtd_user(&mtdoops_notifier); | |
4b23aff0 | 447 | vfree(cxt->oops_buf); |
be95745f | 448 | vfree(cxt->oops_page_used); |
4b23aff0 RP |
449 | } |
450 | ||
451 | ||
2e386e4b SK |
452 | module_init(mtdoops_init); |
453 | module_exit(mtdoops_exit); | |
4b23aff0 RP |
454 | |
455 | MODULE_LICENSE("GPL"); | |
456 | MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>"); | |
457 | MODULE_DESCRIPTION("MTD Oops/Panic console logger/driver"); |