SAFE public projects git trees. - safe/jmp/linux-2.6/blob - drivers/mtd/mtdoops.c

   1 /*
   2  * MTD Oops/Panic logger
   3  *
   4  * Copyright (C) 2007 Nokia Corporation. All rights reserved.
   5  *
   6  * Author: Richard Purdie <rpurdie@openedhand.com>
   7  *
   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.
  11  *
  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.
  16  *
  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
  20  * 02110-1301 USA
  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
  35 struct mtdoops_context {
  36         int mtd_index;
  37         struct work_struct work_erase;
  38         struct work_struct work_write;
  39         struct mtd_info *mtd;
  40         int oops_pages;
  41         int nextpage;
  42         int nextcount;
  43
  44         void *oops_buf;
  45         int ready;
  46         int writecount;
  47 } oops_cxt;
  48
  49 static void mtdoops_erase_callback(struct erase_info *done)
  50 {
  51         wait_queue_head_t *wait_q = (wait_queue_head_t *)done->priv;
  52         wake_up(wait_q);
  53 }
  54
  55 static int mtdoops_erase_block(struct mtd_info *mtd, int offset)
  56 {
  57         struct erase_info erase;
  58         DECLARE_WAITQUEUE(wait, current);
  59         wait_queue_head_t wait_q;
  60         int ret;
  61
  62         init_waitqueue_head(&wait_q);
  63         erase.mtd = mtd;
  64         erase.callback = mtdoops_erase_callback;
  65         erase.addr = offset;
  66         if (mtd->erasesize < OOPS_PAGE_SIZE)
  67                 erase.len = OOPS_PAGE_SIZE;
  68         else
  69                 erase.len = mtd->erasesize;
  70         erase.priv = (u_long)&wait_q;
  71
  72         set_current_state(TASK_INTERRUPTIBLE);
  73         add_wait_queue(&wait_q, &wait);
  74
  75         ret = mtd->erase(mtd, &erase);
  76         if (ret) {
  77                 set_current_state(TASK_RUNNING);
  78                 remove_wait_queue(&wait_q, &wait);
  79                 printk (KERN_WARNING "mtdoops: erase of region [0x%x, 0x%x] "
  80                                      "on \"%s\" failed\n",
  81                         erase.addr, erase.len, mtd->name);
  82                 return ret;
  83         }
  84
  85         schedule();  /* Wait for erase to finish. */
  86         remove_wait_queue(&wait_q, &wait);
  87
  88         return 0;
  89 }
  90
  91 static void mtdoops_inc_counter(struct mtdoops_context *cxt)
  92 {
  93         struct mtd_info *mtd = cxt->mtd;
  94         size_t retlen;
  95         u32 count;
  96         int ret;
  97
  98         cxt->nextpage++;
  99         if (cxt->nextpage > cxt->oops_pages)
 100                 cxt->nextpage = 0;
 101         cxt->nextcount++;
 102         if (cxt->nextcount == 0xffffffff)
 103                 cxt->nextcount = 0;
 104
 105         ret = mtd->read(mtd, cxt->nextpage * OOPS_PAGE_SIZE, 4,
 106                         &retlen, (u_char *) &count);
 107         if ((retlen != 4) || ((ret < 0) && (ret != -EUCLEAN))) {
 108                 printk(KERN_ERR "mtdoops: Read failure at %d (%td of 4 read)"
 109                                 ", err %d.\n", cxt->nextpage * OOPS_PAGE_SIZE,
 110                                 retlen, ret);
 111                 schedule_work(&cxt->work_erase);
 112                 return;
 113         }
 114
 115         /* See if we need to erase the next block */
 116         if (count != 0xffffffff) {
 117                 schedule_work(&cxt->work_erase);
 118                 return;
 119         }
 120
 121         printk(KERN_DEBUG "mtdoops: Ready %d, %d (no erase)\n",
 122                         cxt->nextpage, cxt->nextcount);
 123         cxt->ready = 1;
 124 }
 125
 126 /* Scheduled work - when we can't proceed without erasing a block */
 127 static void mtdoops_workfunc_erase(struct work_struct *work)
 128 {
 129         struct mtdoops_context *cxt =
 130                         container_of(work, struct mtdoops_context, work_erase);
 131         struct mtd_info *mtd = cxt->mtd;
 132         int i = 0, j, ret, mod;
 133
 134         /* We were unregistered */
 135         if (!mtd)
 136                 return;
 137
 138         mod = (cxt->nextpage * OOPS_PAGE_SIZE) % mtd->erasesize;
 139         if (mod != 0) {
 140                 cxt->nextpage = cxt->nextpage + ((mtd->erasesize - mod) / OOPS_PAGE_SIZE);
 141                 if (cxt->nextpage > cxt->oops_pages)
 142                         cxt->nextpage = 0;
 143         }
 144
 145         while (mtd->block_isbad) {
 146                 ret = mtd->block_isbad(mtd, cxt->nextpage * OOPS_PAGE_SIZE);
 147                 if (!ret)
 148                         break;
 149                 if (ret < 0) {
 150                         printk(KERN_ERR "mtdoops: block_isbad failed, aborting.\n");
 151                         return;
 152                 }
 153 badblock:
 154                 printk(KERN_WARNING "mtdoops: Bad block at %08x\n",
 155                                 cxt->nextpage * OOPS_PAGE_SIZE);
 156                 i++;
 157                 cxt->nextpage = cxt->nextpage + (mtd->erasesize / OOPS_PAGE_SIZE);
 158                 if (cxt->nextpage > cxt->oops_pages)
 159                         cxt->nextpage = 0;
 160                 if (i == (cxt->oops_pages / (mtd->erasesize / OOPS_PAGE_SIZE))) {
 161                         printk(KERN_ERR "mtdoops: All blocks bad!\n");
 162                         return;
 163                 }
 164         }
 165
 166         for (j = 0, ret = -1; (j < 3) && (ret < 0); j++)
 167                 ret = mtdoops_erase_block(mtd, cxt->nextpage * OOPS_PAGE_SIZE);
 168
 169         if (ret >= 0) {
 170                 printk(KERN_DEBUG "mtdoops: Ready %d, %d \n", cxt->nextpage, cxt->nextcount);
 171                 cxt->ready = 1;
 172                 return;
 173         }
 174
 175         if (mtd->block_markbad && (ret == -EIO)) {
 176                 ret = mtd->block_markbad(mtd, cxt->nextpage * OOPS_PAGE_SIZE);
 177                 if (ret < 0) {
 178                         printk(KERN_ERR "mtdoops: block_markbad failed, aborting.\n");
 179                         return;
 180                 }
 181         }
 182         goto badblock;
 183 }
 184
 185 static void mtdoops_workfunc_write(struct work_struct *work)
 186 {
 187         struct mtdoops_context *cxt =
 188                         container_of(work, struct mtdoops_context, work_write);
 189         struct mtd_info *mtd = cxt->mtd;
 190         size_t retlen;
 191         int ret;
 192
 193         if (cxt->writecount < OOPS_PAGE_SIZE)
 194                 memset(cxt->oops_buf + cxt->writecount, 0xff,
 195                                         OOPS_PAGE_SIZE - cxt->writecount);
 196
 197         ret = mtd->write(mtd, cxt->nextpage * OOPS_PAGE_SIZE,
 198                                         OOPS_PAGE_SIZE, &retlen, cxt->oops_buf);
 199
 200         cxt->writecount = 0;
 201
 202         if ((retlen != OOPS_PAGE_SIZE) || (ret < 0))
 203                 printk(KERN_ERR "mtdoops: Write failure at %d (%td of %d written), err %d.\n",
 204                         cxt->nextpage * OOPS_PAGE_SIZE, retlen, OOPS_PAGE_SIZE, ret);
 205
 206         mtdoops_inc_counter(cxt);
 207 }
 208
 209 static void find_next_position(struct mtdoops_context *cxt)
 210 {
 211         struct mtd_info *mtd = cxt->mtd;
 212         int ret, page, maxpos = 0;
 213         u32 count, maxcount = 0xffffffff;
 214         size_t retlen;
 215
 216         for (page = 0; page < cxt->oops_pages; page++) {
 217                 ret = mtd->read(mtd, page * OOPS_PAGE_SIZE, 4, &retlen, (u_char *) &count);
 218                 if ((retlen != 4) || ((ret < 0) && (ret != -EUCLEAN))) {
 219                         printk(KERN_ERR "mtdoops: Read failure at %d (%td of 4 read)"
 220                                 ", err %d.\n", page * OOPS_PAGE_SIZE, retlen, ret);
 221                         continue;
 222                 }
 223
 224                 if (count == 0xffffffff)
 225                         continue;
 226                 if (maxcount == 0xffffffff) {
 227                         maxcount = count;
 228                         maxpos = page;
 229                 } else if ((count < 0x40000000) && (maxcount > 0xc0000000)) {
 230                         maxcount = count;
 231                         maxpos = page;
 232                 } else if ((count > maxcount) && (count < 0xc0000000)) {
 233                         maxcount = count;
 234                         maxpos = page;
 235                 } else if ((count > maxcount) && (count > 0xc0000000)
 236                                         && (maxcount > 0x80000000)) {
 237                         maxcount = count;
 238                         maxpos = page;
 239                 }
 240         }
 241         if (maxcount == 0xffffffff) {
 242                 cxt->nextpage = 0;
 243                 cxt->nextcount = 1;
 244                 cxt->ready = 1;
 245                 printk(KERN_DEBUG "mtdoops: Ready %d, %d (first init)\n",
 246                                 cxt->nextpage, cxt->nextcount);
 247                 return;
 248         }
 249
 250         cxt->nextpage = maxpos;
 251         cxt->nextcount = maxcount;
 252
 253         mtdoops_inc_counter(cxt);
 254 }
 255
 256
 257 static void mtdoops_notify_add(struct mtd_info *mtd)
 258 {
 259         struct mtdoops_context *cxt = &oops_cxt;
 260
 261         if ((mtd->index != cxt->mtd_index) || cxt->mtd_index < 0)
 262                 return;
 263
 264         if (mtd->size < (mtd->erasesize * 2)) {
 265                 printk(KERN_ERR "MTD partition %d not big enough for mtdoops\n",
 266                                 mtd->index);
 267                 return;
 268         }
 269
 270         cxt->mtd = mtd;
 271         cxt->oops_pages = mtd->size / OOPS_PAGE_SIZE;
 272
 273         find_next_position(cxt);
 274
 275         printk(KERN_DEBUG "mtdoops: Attached to MTD device %d\n", mtd->index);
 276 }
 277
 278 static void mtdoops_notify_remove(struct mtd_info *mtd)
 279 {
 280         struct mtdoops_context *cxt = &oops_cxt;
 281
 282         if ((mtd->index != cxt->mtd_index) || cxt->mtd_index < 0)
 283                 return;
 284
 285         cxt->mtd = NULL;
 286         flush_scheduled_work();
 287 }
 288
 289 static void mtdoops_console_sync(void)
 290 {
 291         struct mtdoops_context *cxt = &oops_cxt;
 292         struct mtd_info *mtd = cxt->mtd;
 293
 294         if (!cxt->ready || !mtd || cxt->writecount == 0)
 295                 return;
 296
 297         cxt->ready = 0;
 298
 299         schedule_work(&cxt->work_write);
 300 }
 301
 302 static void
 303 mtdoops_console_write(struct console *co, const char *s, unsigned int count)
 304 {
 305         struct mtdoops_context *cxt = co->data;
 306         struct mtd_info *mtd = cxt->mtd;
 307
 308         if (!oops_in_progress) {
 309                 mtdoops_console_sync();
 310                 return;
 311         }
 312
 313         if (!cxt->ready || !mtd)
 314                 return;
 315
 316         if (cxt->writecount == 0) {
 317                 u32 *stamp = cxt->oops_buf;
 318                 *stamp = cxt->nextcount;
 319                 cxt->writecount = 4;
 320         }
 321
 322         if ((count + cxt->writecount) > OOPS_PAGE_SIZE)
 323                 count = OOPS_PAGE_SIZE - cxt->writecount;
 324
 325         memcpy(cxt->oops_buf + cxt->writecount, s, count);
 326         cxt->writecount += count;
 327 }
 328
 329 static int __init mtdoops_console_setup(struct console *co, char *options)
 330 {
 331         struct mtdoops_context *cxt = co->data;
 332
 333         if (cxt->mtd_index != -1)
 334                 return -EBUSY;
 335         if (co->index == -1)
 336                 return -EINVAL;
 337
 338         cxt->mtd_index = co->index;
 339         return 0;
 340 }
 341
 342 static struct mtd_notifier mtdoops_notifier = {
 343         .add    = mtdoops_notify_add,
 344         .remove = mtdoops_notify_remove,
 345 };
 346
 347 static struct console mtdoops_console = {
 348         .name           = "ttyMTD",
 349         .write          = mtdoops_console_write,
 350         .setup          = mtdoops_console_setup,
 351         .unblank        = mtdoops_console_sync,
 352         .flags          = CON_PRINTBUFFER,
 353         .index          = -1,
 354         .data           = &oops_cxt,
 355 };
 356
 357 static int __init mtdoops_console_init(void)
 358 {
 359         struct mtdoops_context *cxt = &oops_cxt;
 360
 361         cxt->mtd_index = -1;
 362         cxt->oops_buf = vmalloc(OOPS_PAGE_SIZE);
 363
 364         if (!cxt->oops_buf) {
 365                 printk(KERN_ERR "Failed to allocate oops buffer workspace\n");
 366                 return -ENOMEM;
 367         }
 368
 369         INIT_WORK(&cxt->work_erase, mtdoops_workfunc_erase);
 370         INIT_WORK(&cxt->work_write, mtdoops_workfunc_write);
 371
 372         register_console(&mtdoops_console);
 373         register_mtd_user(&mtdoops_notifier);
 374         return 0;
 375 }
 376
 377 static void __exit mtdoops_console_exit(void)
 378 {
 379         struct mtdoops_context *cxt = &oops_cxt;
 380
 381         unregister_mtd_user(&mtdoops_notifier);
 382         unregister_console(&mtdoops_console);
 383         vfree(cxt->oops_buf);
 384 }
 385
 386
 387 subsys_initcall(mtdoops_console_init);
 388 module_exit(mtdoops_console_exit);
 389
 390 MODULE_LICENSE("GPL");
 391 MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
 392 MODULE_DESCRIPTION("MTD Oops/Panic console logger/driver");