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 static 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 48 static 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 54 static 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(); /* Wait for erase to finish. */ 85 remove_wait_queue(&wait_q, &wait); 86 87 return 0; 88 } 89 90 static 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 /* See if we need to erase the next block */ 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 } 122 123 static void mtdoops_prepare(struct mtdoops_context *cxt) 124 { 125 struct mtd_info *mtd = cxt->mtd; 126 int i = 0, j, ret, mod; 127 128 /* We were unregistered */ 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)) { 141 badblock: 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 } 167 168 static 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 } 175 176 static 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 } 216 217 218 static 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 } 241 242 static 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 } 252 253 static 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 } 283 284 static void 285 mtdoops_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 } 313 314 static 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 } 326 327 static struct mtd_notifier mtdoops_notifier = { 328 .add = mtdoops_notify_add, 329 .remove = mtdoops_notify_remove, 330 }; 331 332 static 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 }; 341 342 static 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 } 360 361 static 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 } 369 370 371 subsys_initcall(mtdoops_console_init); 372 module_exit(mtdoops_console_exit); 373 374 MODULE_LICENSE("GPL"); 375 MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>"); 376 MODULE_DESCRIPTION("MTD Oops/Panic console logger/driver"); 377