drivers/mtd/tests/oobtest.c

   1 /*
   2  * Copyright (C) 2006-2008 Nokia Corporation
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 as published by
   6  * the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; see the file COPYING. If not, write to the Free Software
  15  * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  16  *
  17  * Test OOB read and write on MTD device.
  18  *
  19  * Author: Adrian Hunter <[email protected]>
  20  */
  21
  22 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  23
  24 #include <asm/div64.h>
  25 #include <linux/init.h>
  26 #include <linux/module.h>
  27 #include <linux/moduleparam.h>
  28 #include <linux/err.h>
  29 #include <linux/mtd/mtd.h>
  30 #include <linux/slab.h>
  31 #include <linux/sched.h>
  32 #include <linux/random.h>
  33
  34 #include "mtd_test.h"
  35
  36 static int dev = -EINVAL;
  37 static int bitflip_limit;
  38 module_param(dev, int, S_IRUGO);
  39 MODULE_PARM_DESC(dev, "MTD device number to use");
  40 module_param(bitflip_limit, int, S_IRUGO);
  41 MODULE_PARM_DESC(bitflip_limit, "Max. allowed bitflips per page");
  42
  43 static struct mtd_info *mtd;
  44 static unsigned char *readbuf;
  45 static unsigned char *writebuf;
  46 static unsigned char *bbt;
  47
  48 static int ebcnt;
  49 static int pgcnt;
  50 static int errcnt;
  51 static int use_offset;
  52 static int use_len;
  53 static int use_len_max;
  54 static int vary_offset;
  55 static struct rnd_state rnd_state;
  56
  57 static void do_vary_offset(void)
  58 {
  59         use_len -= 1;
  60         if (use_len < 1) {
  61                 use_offset += 1;
  62                 if (use_offset >= use_len_max)
  63                         use_offset = 0;
  64                 use_len = use_len_max - use_offset;
  65         }
  66 }
  67
  68 static int write_eraseblock(int ebnum)
  69 {
  70         int i;
  71         struct mtd_oob_ops ops;
  72         int err = 0;
  73         loff_t addr = (loff_t)ebnum * mtd->erasesize;
  74
  75         prandom_bytes_state(&rnd_state, writebuf, use_len_max * pgcnt);
  76         for (i = 0; i < pgcnt; ++i, addr += mtd->writesize) {
  77                 ops.mode      = MTD_OPS_AUTO_OOB;
  78                 ops.len       = 0;
  79                 ops.retlen    = 0;
  80                 ops.ooblen    = use_len;
  81                 ops.oobretlen = 0;
  82                 ops.ooboffs   = use_offset;
  83                 ops.datbuf    = NULL;
  84                 ops.oobbuf    = writebuf + (use_len_max * i) + use_offset;
  85                 err = mtd_write_oob(mtd, addr, &ops);
  86                 if (err || ops.oobretlen != use_len) {
  87                         pr_err("error: writeoob failed at %#llx\n",
  88                                (long long)addr);
  89                         pr_err("error: use_len %d, use_offset %d\n",
  90                                use_len, use_offset);
  91                         errcnt += 1;
  92                         return err ? err : -1;
  93                 }
  94                 if (vary_offset)
  95                         do_vary_offset();
  96         }
  97
  98         return err;
  99 }
 100
 101 static int write_whole_device(void)
 102 {
 103         int err;
 104         unsigned int i;
 105
 106         pr_info("writing OOBs of whole device\n");
 107         for (i = 0; i < ebcnt; ++i) {
 108                 if (bbt[i])
 109                         continue;
 110                 err = write_eraseblock(i);
 111                 if (err)
 112                         return err;
 113                 if (i % 256 == 0)
 114                         pr_info("written up to eraseblock %u\n", i);
 115
 116                 err = mtdtest_relax();
 117                 if (err)
 118                         return err;
 119         }
 120         pr_info("written %u eraseblocks\n", i);
 121         return 0;
 122 }
 123
 124 /*
 125  * Display the address, offset and data bytes at comparison failure.
 126  * Return number of bitflips encountered.
 127  */
 128 static size_t memcmpshowoffset(loff_t addr, loff_t offset, const void *cs,
 129                                const void *ct, size_t count)
 130 {
 131         const unsigned char *su1, *su2;
 132         int res;
 133         size_t i = 0;
 134         size_t bitflips = 0;
 135
 136         for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--, i++) {
 137                 res = *su1 ^ *su2;
 138                 if (res) {
 139                         pr_info("error @addr[0x%lx:0x%lx] 0x%x -> 0x%x diff 0x%x\n",
 140                                 (unsigned long)addr, (unsigned long)offset + i,
 141                                 *su1, *su2, res);
 142                         bitflips += hweight8(res);
 143                 }
 144         }
 145
 146         return bitflips;
 147 }
 148
 149 #define memcmpshow(addr, cs, ct, count) memcmpshowoffset((addr), 0, (cs), (ct),\
 150                                                          (count))
 151
 152 /*
 153  * Compare with 0xff and show the address, offset and data bytes at
 154  * comparison failure. Return number of bitflips encountered.
 155  */
 156 static size_t memffshow(loff_t addr, loff_t offset, const void *cs,
 157                         size_t count)
 158 {
 159         const unsigned char *su1;
 160         int res;
 161         size_t i = 0;
 162         size_t bitflips = 0;
 163
 164         for (su1 = cs; 0 < count; ++su1, count--, i++) {
 165                 res = *su1 ^ 0xff;
 166                 if (res) {
 167                         pr_info("error @addr[0x%lx:0x%lx] 0x%x -> 0xff diff 0x%x\n",
 168                                 (unsigned long)addr, (unsigned long)offset + i,
 169                                 *su1, res);
 170                         bitflips += hweight8(res);
 171                 }
 172         }
 173
 174         return bitflips;
 175 }
 176
 177 static int verify_eraseblock(int ebnum)
 178 {
 179         int i;
 180         struct mtd_oob_ops ops;
 181         int err = 0;
 182         loff_t addr = (loff_t)ebnum * mtd->erasesize;
 183         size_t bitflips;
 184
 185         prandom_bytes_state(&rnd_state, writebuf, use_len_max * pgcnt);
 186         for (i = 0; i < pgcnt; ++i, addr += mtd->writesize) {
 187                 ops.mode      = MTD_OPS_AUTO_OOB;
 188                 ops.len       = 0;
 189                 ops.retlen    = 0;
 190                 ops.ooblen    = use_len;
 191                 ops.oobretlen = 0;
 192                 ops.ooboffs   = use_offset;
 193                 ops.datbuf    = NULL;
 194                 ops.oobbuf    = readbuf;
 195                 err = mtd_read_oob(mtd, addr, &ops);
 196                 if (mtd_is_bitflip(err))
 197                         err = 0;
 198
 199                 if (err || ops.oobretlen != use_len) {
 200                         pr_err("error: readoob failed at %#llx\n",
 201                                (long long)addr);
 202                         errcnt += 1;
 203                         return err ? err : -1;
 204                 }
 205
 206                 bitflips = memcmpshow(addr, readbuf,
 207                                       writebuf + (use_len_max * i) + use_offset,
 208                                       use_len);
 209                 if (bitflips > bitflip_limit) {
 210                         pr_err("error: verify failed at %#llx\n",
 211                                (long long)addr);
 212                         errcnt += 1;
 213                         if (errcnt > 1000) {
 214                                 pr_err("error: too many errors\n");
 215                                 return -1;
 216                         }
 217                 } else if (bitflips) {
 218                         pr_info("ignoring error as within bitflip_limit\n");
 219                 }
 220
 221                 if (use_offset != 0 || use_len < mtd->oobavail) {
 222                         int k;
 223
 224                         ops.mode      = MTD_OPS_AUTO_OOB;
 225                         ops.len       = 0;
 226                         ops.retlen    = 0;
 227                         ops.ooblen    = mtd->oobavail;
 228                         ops.oobretlen = 0;
 229                         ops.ooboffs   = 0;
 230                         ops.datbuf    = NULL;
 231                         ops.oobbuf    = readbuf;
 232                         err = mtd_read_oob(mtd, addr, &ops);
 233                         if (mtd_is_bitflip(err))
 234                                 err = 0;
 235
 236                         if (err || ops.oobretlen != mtd->oobavail) {
 237                                 pr_err("error: readoob failed at %#llx\n",
 238                                                 (long long)addr);
 239                                 errcnt += 1;
 240                                 return err ? err : -1;
 241                         }
 242                         bitflips = memcmpshowoffset(addr, use_offset,
 243                                                     readbuf + use_offset,
 244                                                     writebuf + (use_len_max * i) + use_offset,
 245                                                     use_len);
 246
 247                         /* verify pre-offset area for 0xff */
 248                         bitflips += memffshow(addr, 0, readbuf, use_offset);
 249
 250                         /* verify post-(use_offset + use_len) area for 0xff */
 251                         k = use_offset + use_len;
 252                         bitflips += memffshow(addr, k, readbuf + k,
 253                                               mtd->oobavail - k);
 254
 255                         if (bitflips > bitflip_limit) {
 256                                 pr_err("error: verify failed at %#llx\n",
 257                                                 (long long)addr);
 258                                 errcnt += 1;
 259                                 if (errcnt > 1000) {
 260                                         pr_err("error: too many errors\n");
 261                                         return -1;
 262                                 }
 263                         } else if (bitflips) {
 264                                 pr_info("ignoring errors as within bitflip limit\n");
 265                         }
 266                 }
 267                 if (vary_offset)
 268                         do_vary_offset();
 269         }
 270         return err;
 271 }
 272
 273 static int verify_eraseblock_in_one_go(int ebnum)
 274 {
 275         struct mtd_oob_ops ops;
 276         int err = 0;
 277         loff_t addr = (loff_t)ebnum * mtd->erasesize;
 278         size_t len = mtd->oobavail * pgcnt;
 279         size_t oobavail = mtd->oobavail;
 280         size_t bitflips;
 281         int i;
 282
 283         prandom_bytes_state(&rnd_state, writebuf, len);
 284         ops.mode      = MTD_OPS_AUTO_OOB;
 285         ops.len       = 0;
 286         ops.retlen    = 0;
 287         ops.ooblen    = len;
 288         ops.oobretlen = 0;
 289         ops.ooboffs   = 0;
 290         ops.datbuf    = NULL;
 291         ops.oobbuf    = readbuf;
 292
 293         /* read entire block's OOB at one go */
 294         err = mtd_read_oob(mtd, addr, &ops);
 295         if (mtd_is_bitflip(err))
 296                 err = 0;
 297
 298         if (err || ops.oobretlen != len) {
 299                 pr_err("error: readoob failed at %#llx\n",
 300                        (long long)addr);
 301                 errcnt += 1;
 302                 return err ? err : -1;
 303         }
 304
 305         /* verify one page OOB at a time for bitflip per page limit check */
 306         for (i = 0; i < pgcnt; ++i, addr += mtd->writesize) {
 307                 bitflips = memcmpshow(addr, readbuf + (i * oobavail),
 308                                       writebuf + (i * oobavail), oobavail);
 309                 if (bitflips > bitflip_limit) {
 310                         pr_err("error: verify failed at %#llx\n",
 311                                (long long)addr);
 312                         errcnt += 1;
 313                         if (errcnt > 1000) {
 314                                 pr_err("error: too many errors\n");
 315                                 return -1;
 316                         }
 317                 } else if (bitflips) {
 318                         pr_info("ignoring error as within bitflip_limit\n");
 319                 }
 320         }
 321
 322         return err;
 323 }
 324
 325 static int verify_all_eraseblocks(void)
 326 {
 327         int err;
 328         unsigned int i;
 329
 330         pr_info("verifying all eraseblocks\n");
 331         for (i = 0; i < ebcnt; ++i) {
 332                 if (bbt[i])
 333                         continue;
 334                 err = verify_eraseblock(i);
 335                 if (err)
 336                         return err;
 337                 if (i % 256 == 0)
 338                         pr_info("verified up to eraseblock %u\n", i);
 339
 340                 err = mtdtest_relax();
 341                 if (err)
 342                         return err;
 343         }
 344         pr_info("verified %u eraseblocks\n", i);
 345         return 0;
 346 }
 347
 348 static int __init mtd_oobtest_init(void)
 349 {
 350         int err = 0;
 351         unsigned int i;
 352         uint64_t tmp;
 353         struct mtd_oob_ops ops;
 354         loff_t addr = 0, addr0;
 355
 356         printk(KERN_INFO "\n");
 357         printk(KERN_INFO "=================================================\n");
 358
 359         if (dev < 0) {
 360                 pr_info("Please specify a valid mtd-device via module parameter\n");
 361                 pr_crit("CAREFUL: This test wipes all data on the specified MTD device!\n");
 362                 return -EINVAL;
 363         }
 364
 365         pr_info("MTD device: %d\n", dev);
 366
 367         mtd = get_mtd_device(NULL, dev);
 368         if (IS_ERR(mtd)) {
 369                 err = PTR_ERR(mtd);
 370                 pr_err("error: cannot get MTD device\n");
 371                 return err;
 372         }
 373
 374         if (!mtd_type_is_nand(mtd)) {
 375                 pr_info("this test requires NAND flash\n");
 376                 goto out;
 377         }
 378
 379         tmp = mtd->size;
 380         do_div(tmp, mtd->erasesize);
 381         ebcnt = tmp;
 382         pgcnt = mtd->erasesize / mtd->writesize;
 383
 384         pr_info("MTD device size %llu, eraseblock size %u, "
 385                "page size %u, count of eraseblocks %u, pages per "
 386                "eraseblock %u, OOB size %u\n",
 387                (unsigned long long)mtd->size, mtd->erasesize,
 388                mtd->writesize, ebcnt, pgcnt, mtd->oobsize);
 389
 390         err = -ENOMEM;
 391         readbuf = kmalloc(mtd->erasesize, GFP_KERNEL);
 392         if (!readbuf)
 393                 goto out;
 394         writebuf = kmalloc(mtd->erasesize, GFP_KERNEL);
 395         if (!writebuf)
 396                 goto out;
 397         bbt = kzalloc(ebcnt, GFP_KERNEL);
 398         if (!bbt)
 399                 goto out;
 400
 401         err = mtdtest_scan_for_bad_eraseblocks(mtd, bbt, 0, ebcnt);
 402         if (err)
 403                 goto out;
 404
 405         use_offset = 0;
 406         use_len = mtd->oobavail;
 407         use_len_max = mtd->oobavail;
 408         vary_offset = 0;
 409
 410         /* First test: write all OOB, read it back and verify */
 411         pr_info("test 1 of 5\n");
 412
 413         err = mtdtest_erase_good_eraseblocks(mtd, bbt, 0, ebcnt);
 414         if (err)
 415                 goto out;
 416
 417         prandom_seed_state(&rnd_state, 1);
 418         err = write_whole_device();
 419         if (err)
 420                 goto out;
 421
 422         prandom_seed_state(&rnd_state, 1);
 423         err = verify_all_eraseblocks();
 424         if (err)
 425                 goto out;
 426
 427         /*
 428          * Second test: write all OOB, a block at a time, read it back and
 429          * verify.
 430          */
 431         pr_info("test 2 of 5\n");
 432
 433         err = mtdtest_erase_good_eraseblocks(mtd, bbt, 0, ebcnt);
 434         if (err)
 435                 goto out;
 436
 437         prandom_seed_state(&rnd_state, 3);
 438         err = write_whole_device();
 439         if (err)
 440                 goto out;
 441
 442         /* Check all eraseblocks */
 443         prandom_seed_state(&rnd_state, 3);
 444         pr_info("verifying all eraseblocks\n");
 445         for (i = 0; i < ebcnt; ++i) {
 446                 if (bbt[i])
 447                         continue;
 448                 err = verify_eraseblock_in_one_go(i);
 449                 if (err)
 450                         goto out;
 451                 if (i % 256 == 0)
 452                         pr_info("verified up to eraseblock %u\n", i);
 453
 454                 err = mtdtest_relax();
 455                 if (err)
 456                         goto out;
 457         }
 458         pr_info("verified %u eraseblocks\n", i);
 459
 460         /*
 461          * Third test: write OOB at varying offsets and lengths, read it back
 462          * and verify.
 463          */
 464         pr_info("test 3 of 5\n");
 465
 466         err = mtdtest_erase_good_eraseblocks(mtd, bbt, 0, ebcnt);
 467         if (err)
 468                 goto out;
 469
 470         /* Write all eraseblocks */
 471         use_offset = 0;
 472         use_len = mtd->oobavail;
 473         use_len_max = mtd->oobavail;
 474         vary_offset = 1;
 475         prandom_seed_state(&rnd_state, 5);
 476
 477         err = write_whole_device();
 478         if (err)
 479                 goto out;
 480
 481         /* Check all eraseblocks */
 482         use_offset = 0;
 483         use_len = mtd->oobavail;
 484         use_len_max = mtd->oobavail;
 485         vary_offset = 1;
 486         prandom_seed_state(&rnd_state, 5);
 487         err = verify_all_eraseblocks();
 488         if (err)
 489                 goto out;
 490
 491         use_offset = 0;
 492         use_len = mtd->oobavail;
 493         use_len_max = mtd->oobavail;
 494         vary_offset = 0;
 495
 496         /* Fourth test: try to write off end of device */
 497         pr_info("test 4 of 5\n");
 498
 499         err = mtdtest_erase_good_eraseblocks(mtd, bbt, 0, ebcnt);
 500         if (err)
 501                 goto out;
 502
 503         addr0 = 0;
 504         for (i = 0; i < ebcnt && bbt[i]; ++i)
 505                 addr0 += mtd->erasesize;
 506
 507         /* Attempt to write off end of OOB */
 508         ops.mode      = MTD_OPS_AUTO_OOB;
 509         ops.len       = 0;
 510         ops.retlen    = 0;
 511         ops.ooblen    = 1;
 512         ops.oobretlen = 0;
 513         ops.ooboffs   = mtd->oobavail;
 514         ops.datbuf    = NULL;
 515         ops.oobbuf    = writebuf;
 516         pr_info("attempting to start write past end of OOB\n");
 517         pr_info("an error is expected...\n");
 518         err = mtd_write_oob(mtd, addr0, &ops);
 519         if (err) {
 520                 pr_info("error occurred as expected\n");
 521                 err = 0;
 522         } else {
 523                 pr_err("error: can write past end of OOB\n");
 524                 errcnt += 1;
 525         }
 526
 527         /* Attempt to read off end of OOB */
 528         ops.mode      = MTD_OPS_AUTO_OOB;
 529         ops.len       = 0;
 530         ops.retlen    = 0;
 531         ops.ooblen    = 1;
 532         ops.oobretlen = 0;
 533         ops.ooboffs   = mtd->oobavail;
 534         ops.datbuf    = NULL;
 535         ops.oobbuf    = readbuf;
 536         pr_info("attempting to start read past end of OOB\n");
 537         pr_info("an error is expected...\n");
 538         err = mtd_read_oob(mtd, addr0, &ops);
 539         if (mtd_is_bitflip(err))
 540                 err = 0;
 541
 542         if (err) {
 543                 pr_info("error occurred as expected\n");
 544                 err = 0;
 545         } else {
 546                 pr_err("error: can read past end of OOB\n");
 547                 errcnt += 1;
 548         }
 549
 550         if (bbt[ebcnt - 1])
 551                 pr_info("skipping end of device tests because last "
 552                        "block is bad\n");
 553         else {
 554                 /* Attempt to write off end of device */
 555                 ops.mode      = MTD_OPS_AUTO_OOB;
 556                 ops.len       = 0;
 557                 ops.retlen    = 0;
 558                 ops.ooblen    = mtd->oobavail + 1;
 559                 ops.oobretlen = 0;
 560                 ops.ooboffs   = 0;
 561                 ops.datbuf    = NULL;
 562                 ops.oobbuf    = writebuf;
 563                 pr_info("attempting to write past end of device\n");
 564                 pr_info("an error is expected...\n");
 565                 err = mtd_write_oob(mtd, mtd->size - mtd->writesize, &ops);
 566                 if (err) {
 567                         pr_info("error occurred as expected\n");
 568                         err = 0;
 569                 } else {
 570                         pr_err("error: wrote past end of device\n");
 571                         errcnt += 1;
 572                 }
 573
 574                 /* Attempt to read off end of device */
 575                 ops.mode      = MTD_OPS_AUTO_OOB;
 576                 ops.len       = 0;
 577                 ops.retlen    = 0;
 578                 ops.ooblen    = mtd->oobavail + 1;
 579                 ops.oobretlen = 0;
 580                 ops.ooboffs   = 0;
 581                 ops.datbuf    = NULL;
 582                 ops.oobbuf    = readbuf;
 583                 pr_info("attempting to read past end of device\n");
 584                 pr_info("an error is expected...\n");
 585                 err = mtd_read_oob(mtd, mtd->size - mtd->writesize, &ops);
 586                 if (mtd_is_bitflip(err))
 587                         err = 0;
 588
 589                 if (err) {
 590                         pr_info("error occurred as expected\n");
 591                         err = 0;
 592                 } else {
 593                         pr_err("error: read past end of device\n");
 594                         errcnt += 1;
 595                 }
 596
 597                 err = mtdtest_erase_eraseblock(mtd, ebcnt - 1);
 598                 if (err)
 599                         goto out;
 600
 601                 /* Attempt to write off end of device */
 602                 ops.mode      = MTD_OPS_AUTO_OOB;
 603                 ops.len       = 0;
 604                 ops.retlen    = 0;
 605                 ops.ooblen    = mtd->oobavail;
 606                 ops.oobretlen = 0;
 607                 ops.ooboffs   = 1;
 608                 ops.datbuf    = NULL;
 609                 ops.oobbuf    = writebuf;
 610                 pr_info("attempting to write past end of device\n");
 611                 pr_info("an error is expected...\n");
 612                 err = mtd_write_oob(mtd, mtd->size - mtd->writesize, &ops);
 613                 if (err) {
 614                         pr_info("error occurred as expected\n");
 615                         err = 0;
 616                 } else {
 617                         pr_err("error: wrote past end of device\n");
 618                         errcnt += 1;
 619                 }
 620
 621                 /* Attempt to read off end of device */
 622                 ops.mode      = MTD_OPS_AUTO_OOB;
 623                 ops.len       = 0;
 624                 ops.retlen    = 0;
 625                 ops.ooblen    = mtd->oobavail;
 626                 ops.oobretlen = 0;
 627                 ops.ooboffs   = 1;
 628                 ops.datbuf    = NULL;
 629                 ops.oobbuf    = readbuf;
 630                 pr_info("attempting to read past end of device\n");
 631                 pr_info("an error is expected...\n");
 632                 err = mtd_read_oob(mtd, mtd->size - mtd->writesize, &ops);
 633                 if (mtd_is_bitflip(err))
 634                         err = 0;
 635
 636                 if (err) {
 637                         pr_info("error occurred as expected\n");
 638                         err = 0;
 639                 } else {
 640                         pr_err("error: read past end of device\n");
 641                         errcnt += 1;
 642                 }
 643         }
 644
 645         /* Fifth test: write / read across block boundaries */
 646         pr_info("test 5 of 5\n");
 647
 648         /* Erase all eraseblocks */
 649         err = mtdtest_erase_good_eraseblocks(mtd, bbt, 0, ebcnt);
 650         if (err)
 651                 goto out;
 652
 653         /* Write all eraseblocks */
 654         prandom_seed_state(&rnd_state, 11);
 655         pr_info("writing OOBs of whole device\n");
 656         for (i = 0; i < ebcnt - 1; ++i) {
 657                 int cnt = 2;
 658                 int pg;
 659                 size_t sz = mtd->oobavail;
 660                 if (bbt[i] || bbt[i + 1])
 661                         continue;
 662                 addr = (loff_t)(i + 1) * mtd->erasesize - mtd->writesize;
 663                 prandom_bytes_state(&rnd_state, writebuf, sz * cnt);
 664                 for (pg = 0; pg < cnt; ++pg) {
 665                         ops.mode      = MTD_OPS_AUTO_OOB;
 666                         ops.len       = 0;
 667                         ops.retlen    = 0;
 668                         ops.ooblen    = sz;
 669                         ops.oobretlen = 0;
 670                         ops.ooboffs   = 0;
 671                         ops.datbuf    = NULL;
 672                         ops.oobbuf    = writebuf + pg * sz;
 673                         err = mtd_write_oob(mtd, addr, &ops);
 674                         if (err)
 675                                 goto out;
 676                         if (i % 256 == 0)
 677                                 pr_info("written up to eraseblock %u\n", i);
 678
 679                         err = mtdtest_relax();
 680                         if (err)
 681                                 goto out;
 682
 683                         addr += mtd->writesize;
 684                 }
 685         }
 686         pr_info("written %u eraseblocks\n", i);
 687
 688         /* Check all eraseblocks */
 689         prandom_seed_state(&rnd_state, 11);
 690         pr_info("verifying all eraseblocks\n");
 691         for (i = 0; i < ebcnt - 1; ++i) {
 692                 if (bbt[i] || bbt[i + 1])
 693                         continue;
 694                 prandom_bytes_state(&rnd_state, writebuf, mtd->oobavail * 2);
 695                 addr = (loff_t)(i + 1) * mtd->erasesize - mtd->writesize;
 696                 ops.mode      = MTD_OPS_AUTO_OOB;
 697                 ops.len       = 0;
 698                 ops.retlen    = 0;
 699                 ops.ooblen    = mtd->oobavail * 2;
 700                 ops.oobretlen = 0;
 701                 ops.ooboffs   = 0;
 702                 ops.datbuf    = NULL;
 703                 ops.oobbuf    = readbuf;
 704                 err = mtd_read_oob(mtd, addr, &ops);
 705                 if (mtd_is_bitflip(err))
 706                         err = 0;
 707
 708                 if (err)
 709                         goto out;
 710                 if (memcmpshow(addr, readbuf, writebuf,
 711                                mtd->oobavail * 2)) {
 712                         pr_err("error: verify failed at %#llx\n",
 713                                (long long)addr);
 714                         errcnt += 1;
 715                         if (errcnt > 1000) {
 716                                 pr_err("error: too many errors\n");
 717                                 goto out;
 718                         }
 719                 }
 720                 if (i % 256 == 0)
 721                         pr_info("verified up to eraseblock %u\n", i);
 722
 723                 err = mtdtest_relax();
 724                 if (err)
 725                         goto out;
 726         }
 727         pr_info("verified %u eraseblocks\n", i);
 728
 729         pr_info("finished with %d errors\n", errcnt);
 730 out:
 731         kfree(bbt);
 732         kfree(writebuf);
 733         kfree(readbuf);
 734         put_mtd_device(mtd);
 735         if (err)
 736                 pr_info("error %d occurred\n", err);
 737         printk(KERN_INFO "=================================================\n");
 738         return err;
 739 }
 740 module_init(mtd_oobtest_init);
 741
 742 static void __exit mtd_oobtest_exit(void)
 743 {
 744         return;
 745 }
 746 module_exit(mtd_oobtest_exit);
 747
 748 MODULE_DESCRIPTION("Out-of-band test module");
 749 MODULE_AUTHOR("Adrian Hunter");
 750 MODULE_LICENSE("GPL");