1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
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/mtd/mtd.h>
32
33#define OOPS_PAGE_SIZE 4096
34
35static struct mtdoops_context {
36 int mtd_index;
37 struct work_struct work;
38 struct mtd_info *mtd;
39 int oops_pages;
40 int nextpage;
41 int nextcount;
42
43 void *oops_buf;
44 int ready;
45 int writecount;
46} oops_cxt;
47
48static void mtdoops_erase_callback(struct erase_info *done)
49{
50 wait_queue_head_t *wait_q = (wait_queue_head_t *)done->priv;
51 wake_up(wait_q);
52}
53
54static int mtdoops_erase_block(struct mtd_info *mtd, int offset)
55{
56 struct erase_info erase;
57 DECLARE_WAITQUEUE(wait, current);
58 wait_queue_head_t wait_q;
59 int ret;
60
61 init_waitqueue_head(&wait_q);
62 erase.mtd = mtd;
63 erase.callback = mtdoops_erase_callback;
64 erase.addr = offset;
65 if (mtd->erasesize < OOPS_PAGE_SIZE)
66 erase.len = OOPS_PAGE_SIZE;
67 else
68 erase.len = mtd->erasesize;
69 erase.priv = (u_long)&wait_q;
70
71 set_current_state(TASK_INTERRUPTIBLE);
72 add_wait_queue(&wait_q, &wait);
73
74 ret = mtd->erase(mtd, &erase);
75 if (ret) {
76 set_current_state(TASK_RUNNING);
77 remove_wait_queue(&wait_q, &wait);
78 printk (KERN_WARNING "mtdoops: erase of region [0x%x, 0x%x] "
79 "on \"%s\" failed\n",
80 erase.addr, erase.len, mtd->name);
81 return ret;
82 }
83
84 schedule();
85 remove_wait_queue(&wait_q, &wait);
86
87 return 0;
88}
89
90static int mtdoops_inc_counter(struct mtdoops_context *cxt)
91{
92 struct mtd_info *mtd = cxt->mtd;
93 size_t retlen;
94 u32 count;
95 int ret;
96
97 cxt->nextpage++;
98 if (cxt->nextpage > cxt->oops_pages)
99 cxt->nextpage = 0;
100 cxt->nextcount++;
101 if (cxt->nextcount == 0xffffffff)
102 cxt->nextcount = 0;
103
104 ret = mtd->read(mtd, cxt->nextpage * OOPS_PAGE_SIZE, 4,
105 &retlen, (u_char *) &count);
106 if ((retlen != 4) || (ret < 0)) {
107 printk(KERN_ERR "mtdoops: Read failure at %d (%td of 4 read)"
108 ", err %d.\n", cxt->nextpage * OOPS_PAGE_SIZE,
109 retlen, ret);
110 return 1;
111 }
112
113
114 if (count != 0xffffffff)
115 return 1;
116
117 printk(KERN_DEBUG "mtdoops: Ready %d, %d (no erase)\n",
118 cxt->nextpage, cxt->nextcount);
119 cxt->ready = 1;
120 return 0;
121}
122
123static void mtdoops_prepare(struct mtdoops_context *cxt)
124{
125 struct mtd_info *mtd = cxt->mtd;
126 int i = 0, j, ret, mod;
127
128
129 if (!mtd)
130 return;
131
132 mod = (cxt->nextpage * OOPS_PAGE_SIZE) % mtd->erasesize;
133 if (mod != 0) {
134 cxt->nextpage = cxt->nextpage + ((mtd->erasesize - mod) / OOPS_PAGE_SIZE);
135 if (cxt->nextpage > cxt->oops_pages)
136 cxt->nextpage = 0;
137 }
138
139 while (mtd->block_isbad &&
140 mtd->block_isbad(mtd, cxt->nextpage * OOPS_PAGE_SIZE)) {
141badblock:
142 printk(KERN_WARNING "mtdoops: Bad block at %08x\n",
143 cxt->nextpage * OOPS_PAGE_SIZE);
144 i++;
145 cxt->nextpage = cxt->nextpage + (mtd->erasesize / OOPS_PAGE_SIZE);
146 if (cxt->nextpage > cxt->oops_pages)
147 cxt->nextpage = 0;
148 if (i == (cxt->oops_pages / (mtd->erasesize / OOPS_PAGE_SIZE))) {
149 printk(KERN_ERR "mtdoops: All blocks bad!\n");
150 return;
151 }
152 }
153
154 for (j = 0, ret = -1; (j < 3) && (ret < 0); j++)
155 ret = mtdoops_erase_block(mtd, cxt->nextpage * OOPS_PAGE_SIZE);
156
157 if (ret < 0) {
158 if (mtd->block_markbad)
159 mtd->block_markbad(mtd, cxt->nextpage * OOPS_PAGE_SIZE);
160 goto badblock;
161 }
162
163 printk(KERN_DEBUG "mtdoops: Ready %d, %d \n", cxt->nextpage, cxt->nextcount);
164
165 cxt->ready = 1;
166}
167
168static void mtdoops_workfunc(struct work_struct *work)
169{
170 struct mtdoops_context *cxt =
171 container_of(work, struct mtdoops_context, work);
172
173 mtdoops_prepare(cxt);
174}
175
176static int find_next_position(struct mtdoops_context *cxt)
177{
178 struct mtd_info *mtd = cxt->mtd;
179 int page, maxpos = 0;
180 u32 count, maxcount = 0xffffffff;
181 size_t retlen;
182
183 for (page = 0; page < cxt->oops_pages; page++) {
184 mtd->read(mtd, page * OOPS_PAGE_SIZE, 4, &retlen, (u_char *) &count);
185 if (count == 0xffffffff)
186 continue;
187 if (maxcount == 0xffffffff) {
188 maxcount = count;
189 maxpos = page;
190 } else if ((count < 0x40000000) && (maxcount > 0xc0000000)) {
191 maxcount = count;
192 maxpos = page;
193 } else if ((count > maxcount) && (count < 0xc0000000)) {
194 maxcount = count;
195 maxpos = page;
196 } else if ((count > maxcount) && (count > 0xc0000000)
197 && (maxcount > 0x80000000)) {
198 maxcount = count;
199 maxpos = page;
200 }
201 }
202 if (maxcount == 0xffffffff) {
203 cxt->nextpage = 0;
204 cxt->nextcount = 1;
205 cxt->ready = 1;
206 printk(KERN_DEBUG "mtdoops: Ready %d, %d (first init)\n",
207 cxt->nextpage, cxt->nextcount);
208 return 0;
209 }
210
211 cxt->nextpage = maxpos;
212 cxt->nextcount = maxcount;
213
214 return mtdoops_inc_counter(cxt);
215}
216
217
218static void mtdoops_notify_add(struct mtd_info *mtd)
219{
220 struct mtdoops_context *cxt = &oops_cxt;
221 int ret;
222
223 if ((mtd->index != cxt->mtd_index) || cxt->mtd_index < 0)
224 return;
225
226 if (mtd->size < (mtd->erasesize * 2)) {
227 printk(KERN_ERR "MTD partition %d not big enough for mtdoops\n",
228 mtd->index);
229 return;
230 }
231
232 cxt->mtd = mtd;
233 cxt->oops_pages = mtd->size / OOPS_PAGE_SIZE;
234
235 ret = find_next_position(cxt);
236 if (ret == 1)
237 mtdoops_prepare(cxt);
238
239 printk(KERN_DEBUG "mtdoops: Attached to MTD device %d\n", mtd->index);
240}
241
242static void mtdoops_notify_remove(struct mtd_info *mtd)
243{
244 struct mtdoops_context *cxt = &oops_cxt;
245
246 if ((mtd->index != cxt->mtd_index) || cxt->mtd_index < 0)
247 return;
248
249 cxt->mtd = NULL;
250 flush_scheduled_work();
251}
252
253static void mtdoops_console_sync(void)
254{
255 struct mtdoops_context *cxt = &oops_cxt;
256 struct mtd_info *mtd = cxt->mtd;
257 size_t retlen;
258 int ret;
259
260 if (!cxt->ready || !mtd)
261 return;
262
263 if (cxt->writecount == 0)
264 return;
265
266 if (cxt->writecount < OOPS_PAGE_SIZE)
267 memset(cxt->oops_buf + cxt->writecount, 0xff,
268 OOPS_PAGE_SIZE - cxt->writecount);
269
270 ret = mtd->write(mtd, cxt->nextpage * OOPS_PAGE_SIZE,
271 OOPS_PAGE_SIZE, &retlen, cxt->oops_buf);
272 cxt->ready = 0;
273 cxt->writecount = 0;
274
275 if ((retlen != OOPS_PAGE_SIZE) || (ret < 0))
276 printk(KERN_ERR "mtdoops: Write failure at %d (%td of %d written), err %d.\n",
277 cxt->nextpage * OOPS_PAGE_SIZE, retlen, OOPS_PAGE_SIZE, ret);
278
279 ret = mtdoops_inc_counter(cxt);
280 if (ret == 1)
281 schedule_work(&cxt->work);
282}
283
284static void
285mtdoops_console_write(struct console *co, const char *s, unsigned int count)
286{
287 struct mtdoops_context *cxt = co->data;
288 struct mtd_info *mtd = cxt->mtd;
289 int i;
290
291 if (!oops_in_progress) {
292 mtdoops_console_sync();
293 return;
294 }
295
296 if (!cxt->ready || !mtd)
297 return;
298
299 if (cxt->writecount == 0) {
300 u32 *stamp = cxt->oops_buf;
301 *stamp = cxt->nextcount;
302 cxt->writecount = 4;
303 }
304
305 if ((count + cxt->writecount) > OOPS_PAGE_SIZE)
306 count = OOPS_PAGE_SIZE - cxt->writecount;
307
308 for (i = 0; i < count; i++, s++)
309 *((char *)(cxt->oops_buf) + cxt->writecount + i) = *s;
310
311 cxt->writecount = cxt->writecount + count;
312}
313
314static int __init mtdoops_console_setup(struct console *co, char *options)
315{
316 struct mtdoops_context *cxt = co->data;
317
318 if (cxt->mtd_index != -1)
319 return -EBUSY;
320 if (co->index == -1)
321 return -EINVAL;
322
323 cxt->mtd_index = co->index;
324 return 0;
325}
326
327static struct mtd_notifier mtdoops_notifier = {
328 .add = mtdoops_notify_add,
329 .remove = mtdoops_notify_remove,
330};
331
332static struct console mtdoops_console = {
333 .name = "ttyMTD",
334 .write = mtdoops_console_write,
335 .setup = mtdoops_console_setup,
336 .unblank = mtdoops_console_sync,
337 .flags = CON_PRINTBUFFER,
338 .index = -1,
339 .data = &oops_cxt,
340};
341
342static int __init mtdoops_console_init(void)
343{
344 struct mtdoops_context *cxt = &oops_cxt;
345
346 cxt->mtd_index = -1;
347 cxt->oops_buf = vmalloc(OOPS_PAGE_SIZE);
348
349 if (!cxt->oops_buf) {
350 printk(KERN_ERR "Failed to allocate oops buffer workspace\n");
351 return -ENOMEM;
352 }
353
354 INIT_WORK(&cxt->work, mtdoops_workfunc);
355
356 register_console(&mtdoops_console);
357 register_mtd_user(&mtdoops_notifier);
358 return 0;
359}
360
361static void __exit mtdoops_console_exit(void)
362{
363 struct mtdoops_context *cxt = &oops_cxt;
364
365 unregister_mtd_user(&mtdoops_notifier);
366 unregister_console(&mtdoops_console);
367 vfree(cxt->oops_buf);
368}
369
370
371subsys_initcall(mtdoops_console_init);
372module_exit(mtdoops_console_exit);
373
374MODULE_LICENSE("GPL");
375MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
376MODULE_DESCRIPTION("MTD Oops/Panic console logger/driver");
377
