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 (mtd->block_isbad) {
173 ret = mtd->block_isbad(mtd, cxt->nextpage * record_size);
177 printk(KERN_ERR "mtdoops: block_isbad failed, aborting\n");
181 printk(KERN_WARNING "mtdoops: bad block at %08lx\n",
182 cxt->nextpage * record_size);
184 cxt->nextpage = cxt->nextpage + (mtd->erasesize / record_size);
185 if (cxt->nextpage >= cxt->oops_pages)
187 if (i == cxt->oops_pages / (mtd->erasesize / record_size)) {
188 printk(KERN_ERR "mtdoops: all blocks bad!\n");
193 for (j = 0, ret = -1; (j < 3) && (ret < 0); j++)
194 ret = mtdoops_erase_block(cxt, cxt->nextpage * record_size);
197 printk(KERN_DEBUG "mtdoops: ready %d, %d\n",
198 cxt->nextpage, cxt->nextcount);
202 if (mtd->block_markbad && ret == -EIO) {
203 ret = mtd->block_markbad(mtd, cxt->nextpage * record_size);
205 printk(KERN_ERR "mtdoops: block_markbad failed, aborting\n");
212 static void mtdoops_write(struct mtdoops_context *cxt, int panic)
214 struct mtd_info *mtd = cxt->mtd;
219 /* Add mtdoops header to the buffer */
221 hdr[0] = cxt->nextcount;
222 hdr[1] = MTDOOPS_KERNMSG_MAGIC;
225 ret = mtd->panic_write(mtd, cxt->nextpage * record_size,
226 record_size, &retlen, cxt->oops_buf);
228 ret = mtd->write(mtd, cxt->nextpage * record_size,
229 record_size, &retlen, cxt->oops_buf);
231 if (retlen != record_size || ret < 0)
232 printk(KERN_ERR "mtdoops: write failure at %ld (%td of %ld written), error %d\n",
233 cxt->nextpage * record_size, retlen, record_size, ret);
234 mark_page_used(cxt, cxt->nextpage);
235 memset(cxt->oops_buf, 0xff, record_size);
237 mtdoops_inc_counter(cxt);
240 static void mtdoops_workfunc_write(struct work_struct *work)
242 struct mtdoops_context *cxt =
243 container_of(work, struct mtdoops_context, work_write);
245 mtdoops_write(cxt, 0);
248 static void find_next_position(struct mtdoops_context *cxt)
250 struct mtd_info *mtd = cxt->mtd;
251 int ret, page, maxpos = 0;
252 u32 count[2], maxcount = 0xffffffff;
255 for (page = 0; page < cxt->oops_pages; page++) {
256 /* Assume the page is used */
257 mark_page_used(cxt, page);
258 ret = mtd->read(mtd, page * record_size, MTDOOPS_HEADER_SIZE,
259 &retlen, (u_char *) &count[0]);
260 if (retlen != MTDOOPS_HEADER_SIZE ||
261 (ret < 0 && ret != -EUCLEAN)) {
262 printk(KERN_ERR "mtdoops: read failure at %ld (%td of %d read), err %d\n",
263 page * record_size, retlen,
264 MTDOOPS_HEADER_SIZE, ret);
268 if (count[0] == 0xffffffff && count[1] == 0xffffffff)
269 mark_page_unused(cxt, page);
270 if (count[0] == 0xffffffff)
272 if (maxcount == 0xffffffff) {
275 } else if (count[0] < 0x40000000 && maxcount > 0xc0000000) {
278 } else if (count[0] > maxcount && count[0] < 0xc0000000) {
281 } else if (count[0] > maxcount && count[0] > 0xc0000000
282 && maxcount > 0x80000000) {
287 if (maxcount == 0xffffffff) {
290 schedule_work(&cxt->work_erase);
294 cxt->nextpage = maxpos;
295 cxt->nextcount = maxcount;
297 mtdoops_inc_counter(cxt);
300 static void mtdoops_do_dump(struct kmsg_dumper *dumper,
301 enum kmsg_dump_reason reason, const char *s1, unsigned long l1,
302 const char *s2, unsigned long l2)
304 struct mtdoops_context *cxt = container_of(dumper,
305 struct mtdoops_context, dump);
306 unsigned long s1_start, s2_start;
307 unsigned long l1_cpy, l2_cpy;
310 /* Only dump oopses if dump_oops is set */
311 if (reason == KMSG_DUMP_OOPS && !dump_oops)
314 dst = cxt->oops_buf + MTDOOPS_HEADER_SIZE; /* Skip the header */
315 l2_cpy = min(l2, record_size - MTDOOPS_HEADER_SIZE);
316 l1_cpy = min(l1, record_size - MTDOOPS_HEADER_SIZE - l2_cpy);
318 s2_start = l2 - l2_cpy;
319 s1_start = l1 - l1_cpy;
321 memcpy(dst, s1 + s1_start, l1_cpy);
322 memcpy(dst + l1_cpy, s2 + s2_start, l2_cpy);
324 /* Panics must be written immediately */
325 if (reason != KMSG_DUMP_OOPS) {
326 if (!cxt->mtd->panic_write)
327 printk(KERN_ERR "mtdoops: Cannot write from panic without panic_write\n");
329 mtdoops_write(cxt, 1);
333 /* For other cases, schedule work to write it "nicely" */
334 schedule_work(&cxt->work_write);
337 static void mtdoops_notify_add(struct mtd_info *mtd)
339 struct mtdoops_context *cxt = &oops_cxt;
340 u64 mtdoops_pages = div_u64(mtd->size, record_size);
343 if (!strcmp(mtd->name, mtddev))
344 cxt->mtd_index = mtd->index;
346 if (mtd->index != cxt->mtd_index || cxt->mtd_index < 0)
349 if (mtd->size < mtd->erasesize * 2) {
350 printk(KERN_ERR "mtdoops: MTD partition %d not big enough for mtdoops\n",
354 if (mtd->erasesize < record_size) {
355 printk(KERN_ERR "mtdoops: eraseblock size of MTD partition %d too small\n",
359 if (mtd->size > MTDOOPS_MAX_MTD_SIZE) {
360 printk(KERN_ERR "mtdoops: mtd%d is too large (limit is %d MiB)\n",
361 mtd->index, MTDOOPS_MAX_MTD_SIZE / 1024 / 1024);
365 /* oops_page_used is a bit field */
366 cxt->oops_page_used = vmalloc(DIV_ROUND_UP(mtdoops_pages,
368 if (!cxt->oops_page_used) {
369 printk(KERN_ERR "mtdoops: could not allocate page array\n");
373 cxt->dump.dump = mtdoops_do_dump;
374 err = kmsg_dump_register(&cxt->dump);
376 printk(KERN_ERR "mtdoops: registering kmsg dumper failed, error %d\n", err);
377 vfree(cxt->oops_page_used);
378 cxt->oops_page_used = NULL;
383 cxt->oops_pages = (int)mtd->size / record_size;
384 find_next_position(cxt);
385 printk(KERN_INFO "mtdoops: Attached to MTD device %d\n", mtd->index);
388 static void mtdoops_notify_remove(struct mtd_info *mtd)
390 struct mtdoops_context *cxt = &oops_cxt;
392 if (mtd->index != cxt->mtd_index || cxt->mtd_index < 0)
395 if (kmsg_dump_unregister(&cxt->dump) < 0)
396 printk(KERN_WARNING "mtdoops: could not unregister kmsg_dumper\n");
399 flush_scheduled_work();
403 static struct mtd_notifier mtdoops_notifier = {
404 .add = mtdoops_notify_add,
405 .remove = mtdoops_notify_remove,
408 static int __init mtdoops_init(void)
410 struct mtdoops_context *cxt = &oops_cxt;
414 if (strlen(mtddev) == 0) {
415 printk(KERN_ERR "mtdoops: mtd device (mtddev=name/number) must be supplied\n");
418 if ((record_size & 4095) != 0) {
419 printk(KERN_ERR "mtdoops: record_size must be a multiple of 4096\n");
422 if (record_size < 4096) {
423 printk(KERN_ERR "mtdoops: record_size must be over 4096 bytes\n");
427 /* Setup the MTD device to use */
429 mtd_index = simple_strtoul(mtddev, &endp, 0);
431 cxt->mtd_index = mtd_index;
433 cxt->oops_buf = vmalloc(record_size);
434 if (!cxt->oops_buf) {
435 printk(KERN_ERR "mtdoops: failed to allocate buffer workspace\n");
438 memset(cxt->oops_buf, 0xff, record_size);
440 INIT_WORK(&cxt->work_erase, mtdoops_workfunc_erase);
441 INIT_WORK(&cxt->work_write, mtdoops_workfunc_write);
443 register_mtd_user(&mtdoops_notifier);
447 static void __exit mtdoops_exit(void)
449 struct mtdoops_context *cxt = &oops_cxt;
451 unregister_mtd_user(&mtdoops_notifier);
452 vfree(cxt->oops_buf);
453 vfree(cxt->oops_page_used);
457 module_init(mtdoops_init);
458 module_exit(mtdoops_exit);
460 MODULE_LICENSE("GPL");
461 MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
462 MODULE_DESCRIPTION("MTD Oops/Panic console logger/driver");