2 * MTD Oops/Panic logger
4 * Copyright © 2007 Nokia Corporation. All rights reserved.
6 * Author: Richard Purdie <rpurdie@openedhand.com>
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.
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.
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
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>
36 /* Maximum MTD partition size */
37 #define MTDOOPS_MAX_MTD_SIZE (8 * 1024 * 1024)
39 #define MTDOOPS_KERNMSG_MAGIC 0x5d005d00
40 #define MTDOOPS_HEADER_SIZE 8
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)");
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");
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)");
57 static struct mtdoops_context {
58 struct kmsg_dumper dump;
61 struct work_struct work_erase;
62 struct work_struct work_write;
67 unsigned long *oops_page_used;
72 static void mark_page_used(struct mtdoops_context *cxt, int page)
74 set_bit(page, cxt->oops_page_used);
77 static void mark_page_unused(struct mtdoops_context *cxt, int page)
79 clear_bit(page, cxt->oops_page_used);
82 static int page_is_used(struct mtdoops_context *cxt, int page)
84 return test_bit(page, cxt->oops_page_used);
87 static void mtdoops_erase_callback(struct erase_info *done)
89 wait_queue_head_t *wait_q = (wait_queue_head_t *)done->priv;
93 static int mtdoops_erase_block(struct mtdoops_context *cxt, int offset)
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;
105 init_waitqueue_head(&wait_q);
107 erase.callback = mtdoops_erase_callback;
109 erase.len = mtd->erasesize;
110 erase.priv = (u_long)&wait_q;
112 set_current_state(TASK_INTERRUPTIBLE);
113 add_wait_queue(&wait_q, &wait);
115 ret = mtd_erase(mtd, &erase);
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);
125 schedule(); /* Wait for erase to finish. */
126 remove_wait_queue(&wait_q, &wait);
128 /* Mark pages as unused */
129 for (page = start_page; page < start_page + erase_pages; page++)
130 mark_page_unused(cxt, page);
135 static void mtdoops_inc_counter(struct mtdoops_context *cxt)
138 if (cxt->nextpage >= cxt->oops_pages)
141 if (cxt->nextcount == 0xffffffff)
144 if (page_is_used(cxt, cxt->nextpage)) {
145 schedule_work(&cxt->work_erase);
149 printk(KERN_DEBUG "mtdoops: ready %d, %d (no erase)\n",
150 cxt->nextpage, cxt->nextcount);
153 /* Scheduled work - when we can't proceed without erasing a block */
154 static void mtdoops_workfunc_erase(struct work_struct *work)
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;
161 /* We were unregistered */
165 mod = (cxt->nextpage * record_size) % mtd->erasesize;
167 cxt->nextpage = cxt->nextpage + ((mtd->erasesize - mod) / record_size);
168 if (cxt->nextpage >= cxt->oops_pages)
172 while ((ret = mtd_block_isbad(mtd, cxt->nextpage * record_size)) > 0) {
174 printk(KERN_WARNING "mtdoops: bad block at %08lx\n",
175 cxt->nextpage * record_size);
177 cxt->nextpage = cxt->nextpage + (mtd->erasesize / record_size);
178 if (cxt->nextpage >= cxt->oops_pages)
180 if (i == cxt->oops_pages / (mtd->erasesize / record_size)) {
181 printk(KERN_ERR "mtdoops: all blocks bad!\n");
187 printk(KERN_ERR "mtdoops: mtd_block_isbad failed, aborting\n");
191 for (j = 0, ret = -1; (j < 3) && (ret < 0); j++)
192 ret = mtdoops_erase_block(cxt, cxt->nextpage * record_size);
195 printk(KERN_DEBUG "mtdoops: ready %d, %d\n",
196 cxt->nextpage, cxt->nextcount);
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");
210 static void mtdoops_write(struct mtdoops_context *cxt, int panic)
212 struct mtd_info *mtd = cxt->mtd;
217 /* Add mtdoops header to the buffer */
219 hdr[0] = cxt->nextcount;
220 hdr[1] = MTDOOPS_KERNMSG_MAGIC;
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");
230 ret = mtd_write(mtd, cxt->nextpage * record_size,
231 record_size, &retlen, cxt->oops_buf);
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);
239 mtdoops_inc_counter(cxt);
242 static void mtdoops_workfunc_write(struct work_struct *work)
244 struct mtdoops_context *cxt =
245 container_of(work, struct mtdoops_context, work_write);
247 mtdoops_write(cxt, 0);
250 static void find_next_position(struct mtdoops_context *cxt)
252 struct mtd_info *mtd = cxt->mtd;
253 int ret, page, maxpos = 0;
254 u32 count[2], maxcount = 0xffffffff;
257 for (page = 0; page < cxt->oops_pages; page++) {
258 if (mtd_block_isbad(mtd, page * record_size))
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);
272 if (count[0] == 0xffffffff && count[1] == 0xffffffff)
273 mark_page_unused(cxt, page);
274 if (count[0] == 0xffffffff)
276 if (maxcount == 0xffffffff) {
279 } else if (count[0] < 0x40000000 && maxcount > 0xc0000000) {
282 } else if (count[0] > maxcount && count[0] < 0xc0000000) {
285 } else if (count[0] > maxcount && count[0] > 0xc0000000
286 && maxcount > 0x80000000) {
291 if (maxcount == 0xffffffff) {
294 schedule_work(&cxt->work_erase);
298 cxt->nextpage = maxpos;
299 cxt->nextcount = maxcount;
301 mtdoops_inc_counter(cxt);
304 static void mtdoops_do_dump(struct kmsg_dumper *dumper,
305 enum kmsg_dump_reason reason)
307 struct mtdoops_context *cxt = container_of(dumper,
308 struct mtdoops_context, dump);
310 /* Only dump oopses if dump_oops is set */
311 if (reason == KMSG_DUMP_OOPS && !dump_oops)
314 kmsg_dump_get_buffer(dumper, true, cxt->oops_buf + MTDOOPS_HEADER_SIZE,
315 record_size - MTDOOPS_HEADER_SIZE, NULL);
317 /* Panics must be written immediately */
318 if (reason != KMSG_DUMP_OOPS)
319 mtdoops_write(cxt, 1);
321 /* For other cases, schedule work to write it "nicely" */
322 schedule_work(&cxt->work_write);
325 static void mtdoops_notify_add(struct mtd_info *mtd)
327 struct mtdoops_context *cxt = &oops_cxt;
328 u64 mtdoops_pages = div_u64(mtd->size, record_size);
331 if (!strcmp(mtd->name, mtddev))
332 cxt->mtd_index = mtd->index;
334 if (mtd->index != cxt->mtd_index || cxt->mtd_index < 0)
337 if (mtd->size < mtd->erasesize * 2) {
338 printk(KERN_ERR "mtdoops: MTD partition %d not big enough for mtdoops\n",
342 if (mtd->erasesize < record_size) {
343 printk(KERN_ERR "mtdoops: eraseblock size of MTD partition %d too small\n",
347 if (mtd->size > MTDOOPS_MAX_MTD_SIZE) {
348 printk(KERN_ERR "mtdoops: mtd%d is too large (limit is %d MiB)\n",
349 mtd->index, MTDOOPS_MAX_MTD_SIZE / 1024 / 1024);
353 /* oops_page_used is a bit field */
354 cxt->oops_page_used = vmalloc(DIV_ROUND_UP(mtdoops_pages,
355 BITS_PER_LONG) * sizeof(unsigned long));
356 if (!cxt->oops_page_used) {
357 printk(KERN_ERR "mtdoops: could not allocate page array\n");
361 cxt->dump.max_reason = KMSG_DUMP_OOPS;
362 cxt->dump.dump = mtdoops_do_dump;
363 err = kmsg_dump_register(&cxt->dump);
365 printk(KERN_ERR "mtdoops: registering kmsg dumper failed, error %d\n", err);
366 vfree(cxt->oops_page_used);
367 cxt->oops_page_used = NULL;
372 cxt->oops_pages = (int)mtd->size / record_size;
373 find_next_position(cxt);
374 printk(KERN_INFO "mtdoops: Attached to MTD device %d\n", mtd->index);
377 static void mtdoops_notify_remove(struct mtd_info *mtd)
379 struct mtdoops_context *cxt = &oops_cxt;
381 if (mtd->index != cxt->mtd_index || cxt->mtd_index < 0)
384 if (kmsg_dump_unregister(&cxt->dump) < 0)
385 printk(KERN_WARNING "mtdoops: could not unregister kmsg_dumper\n");
388 flush_work(&cxt->work_erase);
389 flush_work(&cxt->work_write);
393 static struct mtd_notifier mtdoops_notifier = {
394 .add = mtdoops_notify_add,
395 .remove = mtdoops_notify_remove,
398 static int __init mtdoops_init(void)
400 struct mtdoops_context *cxt = &oops_cxt;
404 if (strlen(mtddev) == 0) {
405 printk(KERN_ERR "mtdoops: mtd device (mtddev=name/number) must be supplied\n");
408 if ((record_size & 4095) != 0) {
409 printk(KERN_ERR "mtdoops: record_size must be a multiple of 4096\n");
412 if (record_size < 4096) {
413 printk(KERN_ERR "mtdoops: record_size must be over 4096 bytes\n");
417 /* Setup the MTD device to use */
419 mtd_index = simple_strtoul(mtddev, &endp, 0);
421 cxt->mtd_index = mtd_index;
423 cxt->oops_buf = vmalloc(record_size);
424 if (!cxt->oops_buf) {
425 printk(KERN_ERR "mtdoops: failed to allocate buffer workspace\n");
428 memset(cxt->oops_buf, 0xff, record_size);
430 INIT_WORK(&cxt->work_erase, mtdoops_workfunc_erase);
431 INIT_WORK(&cxt->work_write, mtdoops_workfunc_write);
433 register_mtd_user(&mtdoops_notifier);
437 static void __exit mtdoops_exit(void)
439 struct mtdoops_context *cxt = &oops_cxt;
441 unregister_mtd_user(&mtdoops_notifier);
442 vfree(cxt->oops_buf);
443 vfree(cxt->oops_page_used);
447 module_init(mtdoops_init);
448 module_exit(mtdoops_exit);
450 MODULE_LICENSE("GPL");
451 MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
452 MODULE_DESCRIPTION("MTD Oops/Panic console logger/driver");