1 /* 2 * Copyright © 2009 - Maxim Levitsky 3 * SmartMedia/xD translation layer 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 */ 9 10 #include <linux/kernel.h> 11 #include <linux/module.h> 12 #include <linux/random.h> 13 #include <linux/hdreg.h> 14 #include <linux/kthread.h> 15 #include <linux/freezer.h> 16 #include <linux/sysfs.h> 17 #include <linux/bitops.h> 18 #include <linux/slab.h> 19 #include <linux/mtd/nand_ecc.h> 20 #include "nand/raw/sm_common.h" 21 #include "sm_ftl.h" 22 23 24 25 static struct workqueue_struct *cache_flush_workqueue; 26 27 static int cache_timeout = 1000; 28 module_param(cache_timeout, int, S_IRUGO); 29 MODULE_PARM_DESC(cache_timeout, 30 "Timeout (in ms) for cache flush (1000 ms default"); 31 32 static int debug; 33 module_param(debug, int, S_IRUGO | S_IWUSR); 34 MODULE_PARM_DESC(debug, "Debug level (0-2)"); 35 36 37 /* ------------------- sysfs attributes ---------------------------------- */ 38 struct sm_sysfs_attribute { 39 struct device_attribute dev_attr; 40 char *data; 41 int len; 42 }; 43 44 static ssize_t sm_attr_show(struct device *dev, struct device_attribute *attr, 45 char *buf) 46 { 47 struct sm_sysfs_attribute *sm_attr = 48 container_of(attr, struct sm_sysfs_attribute, dev_attr); 49 50 strncpy(buf, sm_attr->data, sm_attr->len); 51 return sm_attr->len; 52 } 53 54 55 #define NUM_ATTRIBUTES 1 56 #define SM_CIS_VENDOR_OFFSET 0x59 57 static struct attribute_group *sm_create_sysfs_attributes(struct sm_ftl *ftl) 58 { 59 struct attribute_group *attr_group; 60 struct attribute **attributes; 61 struct sm_sysfs_attribute *vendor_attribute; 62 char *vendor; 63 64 vendor = kstrndup(ftl->cis_buffer + SM_CIS_VENDOR_OFFSET, 65 SM_SMALL_PAGE - SM_CIS_VENDOR_OFFSET, GFP_KERNEL); 66 if (!vendor) 67 goto error1; 68 69 /* Initialize sysfs attributes */ 70 vendor_attribute = 71 kzalloc(sizeof(struct sm_sysfs_attribute), GFP_KERNEL); 72 if (!vendor_attribute) 73 goto error2; 74 75 sysfs_attr_init(&vendor_attribute->dev_attr.attr); 76 77 vendor_attribute->data = vendor; 78 vendor_attribute->len = strlen(vendor); 79 vendor_attribute->dev_attr.attr.name = "vendor"; 80 vendor_attribute->dev_attr.attr.mode = S_IRUGO; 81 vendor_attribute->dev_attr.show = sm_attr_show; 82 83 84 /* Create array of pointers to the attributes */ 85 attributes = kcalloc(NUM_ATTRIBUTES + 1, sizeof(struct attribute *), 86 GFP_KERNEL); 87 if (!attributes) 88 goto error3; 89 attributes[0] = &vendor_attribute->dev_attr.attr; 90 91 /* Finally create the attribute group */ 92 attr_group = kzalloc(sizeof(struct attribute_group), GFP_KERNEL); 93 if (!attr_group) 94 goto error4; 95 attr_group->attrs = attributes; 96 return attr_group; 97 error4: 98 kfree(attributes); 99 error3: 100 kfree(vendor_attribute); 101 error2: 102 kfree(vendor); 103 error1: 104 return NULL; 105 } 106 107 static void sm_delete_sysfs_attributes(struct sm_ftl *ftl) 108 { 109 struct attribute **attributes = ftl->disk_attributes->attrs; 110 int i; 111 112 for (i = 0; attributes[i] ; i++) { 113 114 struct device_attribute *dev_attr = container_of(attributes[i], 115 struct device_attribute, attr); 116 117 struct sm_sysfs_attribute *sm_attr = 118 container_of(dev_attr, 119 struct sm_sysfs_attribute, dev_attr); 120 121 kfree(sm_attr->data); 122 kfree(sm_attr); 123 } 124 125 kfree(ftl->disk_attributes->attrs); 126 kfree(ftl->disk_attributes); 127 } 128 129 130 /* ----------------------- oob helpers -------------------------------------- */ 131 132 static int sm_get_lba(uint8_t *lba) 133 { 134 /* check fixed bits */ 135 if ((lba[0] & 0xF8) != 0x10) 136 return -2; 137 138 /* check parity - endianness doesn't matter */ 139 if (hweight16(*(uint16_t *)lba) & 1) 140 return -2; 141 142 return (lba[1] >> 1) | ((lba[0] & 0x07) << 7); 143 } 144 145 146 /* 147 * Read LBA associated with block 148 * returns -1, if block is erased 149 * returns -2 if error happens 150 */ 151 static int sm_read_lba(struct sm_oob *oob) 152 { 153 static const uint32_t erased_pattern[4] = { 154 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF }; 155 156 uint16_t lba_test; 157 int lba; 158 159 /* First test for erased block */ 160 if (!memcmp(oob, erased_pattern, SM_OOB_SIZE)) 161 return -1; 162 163 /* Now check is both copies of the LBA differ too much */ 164 lba_test = *(uint16_t *)oob->lba_copy1 ^ *(uint16_t*)oob->lba_copy2; 165 if (lba_test && !is_power_of_2(lba_test)) 166 return -2; 167 168 /* And read it */ 169 lba = sm_get_lba(oob->lba_copy1); 170 171 if (lba == -2) 172 lba = sm_get_lba(oob->lba_copy2); 173 174 return lba; 175 } 176 177 static void sm_write_lba(struct sm_oob *oob, uint16_t lba) 178 { 179 uint8_t tmp[2]; 180 181 WARN_ON(lba >= 1000); 182 183 tmp[0] = 0x10 | ((lba >> 7) & 0x07); 184 tmp[1] = (lba << 1) & 0xFF; 185 186 if (hweight16(*(uint16_t *)tmp) & 0x01) 187 tmp[1] |= 1; 188 189 oob->lba_copy1[0] = oob->lba_copy2[0] = tmp[0]; 190 oob->lba_copy1[1] = oob->lba_copy2[1] = tmp[1]; 191 } 192 193 194 /* Make offset from parts */ 195 static loff_t sm_mkoffset(struct sm_ftl *ftl, int zone, int block, int boffset) 196 { 197 WARN_ON(boffset & (SM_SECTOR_SIZE - 1)); 198 WARN_ON(zone < 0 || zone >= ftl->zone_count); 199 WARN_ON(block >= ftl->zone_size); 200 WARN_ON(boffset >= ftl->block_size); 201 202 if (block == -1) 203 return -1; 204 205 return (zone * SM_MAX_ZONE_SIZE + block) * ftl->block_size + boffset; 206 } 207 208 /* Breaks offset into parts */ 209 static void sm_break_offset(struct sm_ftl *ftl, loff_t loffset, 210 int *zone, int *block, int *boffset) 211 { 212 u64 offset = loffset; 213 *boffset = do_div(offset, ftl->block_size); 214 *block = do_div(offset, ftl->max_lba); 215 *zone = offset >= ftl->zone_count ? -1 : offset; 216 } 217 218 /* ---------------------- low level IO ------------------------------------- */ 219 220 static int sm_correct_sector(uint8_t *buffer, struct sm_oob *oob) 221 { 222 uint8_t ecc[3]; 223 224 __nand_calculate_ecc(buffer, SM_SMALL_PAGE, ecc, 225 IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING_SMC)); 226 if (__nand_correct_data(buffer, ecc, oob->ecc1, SM_SMALL_PAGE, 227 IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING_SMC)) < 0) 228 return -EIO; 229 230 buffer += SM_SMALL_PAGE; 231 232 __nand_calculate_ecc(buffer, SM_SMALL_PAGE, ecc, 233 IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING_SMC)); 234 if (__nand_correct_data(buffer, ecc, oob->ecc2, SM_SMALL_PAGE, 235 IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING_SMC)) < 0) 236 return -EIO; 237 return 0; 238 } 239 240 /* Reads a sector + oob*/ 241 static int sm_read_sector(struct sm_ftl *ftl, 242 int zone, int block, int boffset, 243 uint8_t *buffer, struct sm_oob *oob) 244 { 245 struct mtd_info *mtd = ftl->trans->mtd; 246 struct mtd_oob_ops ops; 247 struct sm_oob tmp_oob; 248 int ret = -EIO; 249 int try = 0; 250 251 /* FTL can contain -1 entries that are by default filled with bits */ 252 if (block == -1) { 253 memset(buffer, 0xFF, SM_SECTOR_SIZE); 254 return 0; 255 } 256 257 /* User might not need the oob, but we do for data verification */ 258 if (!oob) 259 oob = &tmp_oob; 260 261 ops.mode = ftl->smallpagenand ? MTD_OPS_RAW : MTD_OPS_PLACE_OOB; 262 ops.ooboffs = 0; 263 ops.ooblen = SM_OOB_SIZE; 264 ops.oobbuf = (void *)oob; 265 ops.len = SM_SECTOR_SIZE; 266 ops.datbuf = buffer; 267 268 again: 269 if (try++) { 270 /* Avoid infinite recursion on CIS reads, sm_recheck_media 271 won't help anyway */ 272 if (zone == 0 && block == ftl->cis_block && boffset == 273 ftl->cis_boffset) 274 return ret; 275 276 /* Test if media is stable */ 277 if (try == 3 || sm_recheck_media(ftl)) 278 return ret; 279 } 280 281 /* Unfortunately, oob read will _always_ succeed, 282 despite card removal..... */ 283 ret = mtd_read_oob(mtd, sm_mkoffset(ftl, zone, block, boffset), &ops); 284 285 /* Test for unknown errors */ 286 if (ret != 0 && !mtd_is_bitflip_or_eccerr(ret)) { 287 dbg("read of block %d at zone %d, failed due to error (%d)", 288 block, zone, ret); 289 goto again; 290 } 291 292 /* Do a basic test on the oob, to guard against returned garbage */ 293 if (oob->reserved != 0xFFFFFFFF && !is_power_of_2(~oob->reserved)) 294 goto again; 295 296 /* This should never happen, unless there is a bug in the mtd driver */ 297 WARN_ON(ops.oobretlen != SM_OOB_SIZE); 298 WARN_ON(buffer && ops.retlen != SM_SECTOR_SIZE); 299 300 if (!buffer) 301 return 0; 302 303 /* Test if sector marked as bad */ 304 if (!sm_sector_valid(oob)) { 305 dbg("read of block %d at zone %d, failed because it is marked" 306 " as bad" , block, zone); 307 goto again; 308 } 309 310 /* Test ECC*/ 311 if (mtd_is_eccerr(ret) || 312 (ftl->smallpagenand && sm_correct_sector(buffer, oob))) { 313 314 dbg("read of block %d at zone %d, failed due to ECC error", 315 block, zone); 316 goto again; 317 } 318 319 return 0; 320 } 321 322 /* Writes a sector to media */ 323 static int sm_write_sector(struct sm_ftl *ftl, 324 int zone, int block, int boffset, 325 uint8_t *buffer, struct sm_oob *oob) 326 { 327 struct mtd_oob_ops ops; 328 struct mtd_info *mtd = ftl->trans->mtd; 329 int ret; 330 331 BUG_ON(ftl->readonly); 332 333 if (zone == 0 && (block == ftl->cis_block || block == 0)) { 334 dbg("attempted to write the CIS!"); 335 return -EIO; 336 } 337 338 if (ftl->unstable) 339 return -EIO; 340 341 ops.mode = ftl->smallpagenand ? MTD_OPS_RAW : MTD_OPS_PLACE_OOB; 342 ops.len = SM_SECTOR_SIZE; 343 ops.datbuf = buffer; 344 ops.ooboffs = 0; 345 ops.ooblen = SM_OOB_SIZE; 346 ops.oobbuf = (void *)oob; 347 348 ret = mtd_write_oob(mtd, sm_mkoffset(ftl, zone, block, boffset), &ops); 349 350 /* Now we assume that hardware will catch write bitflip errors */ 351 352 if (ret) { 353 dbg("write to block %d at zone %d, failed with error %d", 354 block, zone, ret); 355 356 sm_recheck_media(ftl); 357 return ret; 358 } 359 360 /* This should never happen, unless there is a bug in the driver */ 361 WARN_ON(ops.oobretlen != SM_OOB_SIZE); 362 WARN_ON(buffer && ops.retlen != SM_SECTOR_SIZE); 363 364 return 0; 365 } 366 367 /* ------------------------ block IO ------------------------------------- */ 368 369 /* Write a block using data and lba, and invalid sector bitmap */ 370 static int sm_write_block(struct sm_ftl *ftl, uint8_t *buf, 371 int zone, int block, int lba, 372 unsigned long invalid_bitmap) 373 { 374 struct sm_oob oob; 375 int boffset; 376 int retry = 0; 377 378 /* Initialize the oob with requested values */ 379 memset(&oob, 0xFF, SM_OOB_SIZE); 380 sm_write_lba(&oob, lba); 381 restart: 382 if (ftl->unstable) 383 return -EIO; 384 385 for (boffset = 0; boffset < ftl->block_size; 386 boffset += SM_SECTOR_SIZE) { 387 388 oob.data_status = 0xFF; 389 390 if (test_bit(boffset / SM_SECTOR_SIZE, &invalid_bitmap)) { 391 392 sm_printk("sector %d of block at LBA %d of zone %d" 393 " couldn't be read, marking it as invalid", 394 boffset / SM_SECTOR_SIZE, lba, zone); 395 396 oob.data_status = 0; 397 } 398 399 if (ftl->smallpagenand) { 400 __nand_calculate_ecc(buf + boffset, SM_SMALL_PAGE, 401 oob.ecc1, 402 IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING_SMC)); 403 404 __nand_calculate_ecc(buf + boffset + SM_SMALL_PAGE, 405 SM_SMALL_PAGE, oob.ecc2, 406 IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING_SMC)); 407 } 408 if (!sm_write_sector(ftl, zone, block, boffset, 409 buf + boffset, &oob)) 410 continue; 411 412 if (!retry) { 413 414 /* If write fails. try to erase the block */ 415 /* This is safe, because we never write in blocks 416 that contain valuable data. 417 This is intended to repair block that are marked 418 as erased, but that isn't fully erased*/ 419 420 if (sm_erase_block(ftl, zone, block, 0)) 421 return -EIO; 422 423 retry = 1; 424 goto restart; 425 } else { 426 sm_mark_block_bad(ftl, zone, block); 427 return -EIO; 428 } 429 } 430 return 0; 431 } 432 433 434 /* Mark whole block at offset 'offs' as bad. */ 435 static void sm_mark_block_bad(struct sm_ftl *ftl, int zone, int block) 436 { 437 struct sm_oob oob; 438 int boffset; 439 440 memset(&oob, 0xFF, SM_OOB_SIZE); 441 oob.block_status = 0xF0; 442 443 if (ftl->unstable) 444 return; 445 446 if (sm_recheck_media(ftl)) 447 return; 448 449 sm_printk("marking block %d of zone %d as bad", block, zone); 450 451 /* We aren't checking the return value, because we don't care */ 452 /* This also fails on fake xD cards, but I guess these won't expose 453 any bad blocks till fail completely */ 454 for (boffset = 0; boffset < ftl->block_size; boffset += SM_SECTOR_SIZE) 455 sm_write_sector(ftl, zone, block, boffset, NULL, &oob); 456 } 457 458 /* 459 * Erase a block within a zone 460 * If erase succeeds, it updates free block fifo, otherwise marks block as bad 461 */ 462 static int sm_erase_block(struct sm_ftl *ftl, int zone_num, uint16_t block, 463 int put_free) 464 { 465 struct ftl_zone *zone = &ftl->zones[zone_num]; 466 struct mtd_info *mtd = ftl->trans->mtd; 467 struct erase_info erase; 468 469 erase.addr = sm_mkoffset(ftl, zone_num, block, 0); 470 erase.len = ftl->block_size; 471 472 if (ftl->unstable) 473 return -EIO; 474 475 BUG_ON(ftl->readonly); 476 477 if (zone_num == 0 && (block == ftl->cis_block || block == 0)) { 478 sm_printk("attempted to erase the CIS!"); 479 return -EIO; 480 } 481 482 if (mtd_erase(mtd, &erase)) { 483 sm_printk("erase of block %d in zone %d failed", 484 block, zone_num); 485 goto error; 486 } 487 488 if (put_free) 489 kfifo_in(&zone->free_sectors, 490 (const unsigned char *)&block, sizeof(block)); 491 492 return 0; 493 error: 494 sm_mark_block_bad(ftl, zone_num, block); 495 return -EIO; 496 } 497 498 /* Thoroughly test that block is valid. */ 499 static int sm_check_block(struct sm_ftl *ftl, int zone, int block) 500 { 501 int boffset; 502 struct sm_oob oob; 503 int lbas[] = { -3, 0, 0, 0 }; 504 int i = 0; 505 int test_lba; 506 507 508 /* First just check that block doesn't look fishy */ 509 /* Only blocks that are valid or are sliced in two parts, are 510 accepted */ 511 for (boffset = 0; boffset < ftl->block_size; 512 boffset += SM_SECTOR_SIZE) { 513 514 /* This shouldn't happen anyway */ 515 if (sm_read_sector(ftl, zone, block, boffset, NULL, &oob)) 516 return -2; 517 518 test_lba = sm_read_lba(&oob); 519 520 if (lbas[i] != test_lba) 521 lbas[++i] = test_lba; 522 523 /* If we found three different LBAs, something is fishy */ 524 if (i == 3) 525 return -EIO; 526 } 527 528 /* If the block is sliced (partially erased usually) erase it */ 529 if (i == 2) { 530 sm_erase_block(ftl, zone, block, 1); 531 return 1; 532 } 533 534 return 0; 535 } 536 537 /* ----------------- media scanning --------------------------------- */ 538 static const struct chs_entry chs_table[] = { 539 { 1, 125, 4, 4 }, 540 { 2, 125, 4, 8 }, 541 { 4, 250, 4, 8 }, 542 { 8, 250, 4, 16 }, 543 { 16, 500, 4, 16 }, 544 { 32, 500, 8, 16 }, 545 { 64, 500, 8, 32 }, 546 { 128, 500, 16, 32 }, 547 { 256, 1000, 16, 32 }, 548 { 512, 1015, 32, 63 }, 549 { 1024, 985, 33, 63 }, 550 { 2048, 985, 33, 63 }, 551 { 0 }, 552 }; 553 554 555 static const uint8_t cis_signature[] = { 556 0x01, 0x03, 0xD9, 0x01, 0xFF, 0x18, 0x02, 0xDF, 0x01, 0x20 557 }; 558 /* Find out media parameters. 559 * This ideally has to be based on nand id, but for now device size is enough */ 560 static int sm_get_media_info(struct sm_ftl *ftl, struct mtd_info *mtd) 561 { 562 int i; 563 int size_in_megs = mtd->size / (1024 * 1024); 564 565 ftl->readonly = mtd->type == MTD_ROM; 566 567 /* Manual settings for very old devices */ 568 ftl->zone_count = 1; 569 ftl->smallpagenand = 0; 570 571 switch (size_in_megs) { 572 case 1: 573 /* 1 MiB flash/rom SmartMedia card (256 byte pages)*/ 574 ftl->zone_size = 256; 575 ftl->max_lba = 250; 576 ftl->block_size = 8 * SM_SECTOR_SIZE; 577 ftl->smallpagenand = 1; 578 579 break; 580 case 2: 581 /* 2 MiB flash SmartMedia (256 byte pages)*/ 582 if (mtd->writesize == SM_SMALL_PAGE) { 583 ftl->zone_size = 512; 584 ftl->max_lba = 500; 585 ftl->block_size = 8 * SM_SECTOR_SIZE; 586 ftl->smallpagenand = 1; 587 /* 2 MiB rom SmartMedia */ 588 } else { 589 590 if (!ftl->readonly) 591 return -ENODEV; 592 593 ftl->zone_size = 256; 594 ftl->max_lba = 250; 595 ftl->block_size = 16 * SM_SECTOR_SIZE; 596 } 597 break; 598 case 4: 599 /* 4 MiB flash/rom SmartMedia device */ 600 ftl->zone_size = 512; 601 ftl->max_lba = 500; 602 ftl->block_size = 16 * SM_SECTOR_SIZE; 603 break; 604 case 8: 605 /* 8 MiB flash/rom SmartMedia device */ 606 ftl->zone_size = 1024; 607 ftl->max_lba = 1000; 608 ftl->block_size = 16 * SM_SECTOR_SIZE; 609 } 610 611 /* Minimum xD size is 16MiB. Also, all xD cards have standard zone 612 sizes. SmartMedia cards exist up to 128 MiB and have same layout*/ 613 if (size_in_megs >= 16) { 614 ftl->zone_count = size_in_megs / 16; 615 ftl->zone_size = 1024; 616 ftl->max_lba = 1000; 617 ftl->block_size = 32 * SM_SECTOR_SIZE; 618 } 619 620 /* Test for proper write,erase and oob sizes */ 621 if (mtd->erasesize > ftl->block_size) 622 return -ENODEV; 623 624 if (mtd->writesize > SM_SECTOR_SIZE) 625 return -ENODEV; 626 627 if (ftl->smallpagenand && mtd->oobsize < SM_SMALL_OOB_SIZE) 628 return -ENODEV; 629 630 if (!ftl->smallpagenand && mtd->oobsize < SM_OOB_SIZE) 631 return -ENODEV; 632 633 /* We use OOB */ 634 if (!mtd_has_oob(mtd)) 635 return -ENODEV; 636 637 /* Find geometry information */ 638 for (i = 0 ; i < ARRAY_SIZE(chs_table) ; i++) { 639 if (chs_table[i].size == size_in_megs) { 640 ftl->cylinders = chs_table[i].cyl; 641 ftl->heads = chs_table[i].head; 642 ftl->sectors = chs_table[i].sec; 643 return 0; 644 } 645 } 646 647 sm_printk("media has unknown size : %dMiB", size_in_megs); 648 ftl->cylinders = 985; 649 ftl->heads = 33; 650 ftl->sectors = 63; 651 return 0; 652 } 653 654 /* Validate the CIS */ 655 static int sm_read_cis(struct sm_ftl *ftl) 656 { 657 struct sm_oob oob; 658 659 if (sm_read_sector(ftl, 660 0, ftl->cis_block, ftl->cis_boffset, ftl->cis_buffer, &oob)) 661 return -EIO; 662 663 if (!sm_sector_valid(&oob) || !sm_block_valid(&oob)) 664 return -EIO; 665 666 if (!memcmp(ftl->cis_buffer + ftl->cis_page_offset, 667 cis_signature, sizeof(cis_signature))) { 668 return 0; 669 } 670 671 return -EIO; 672 } 673 674 /* Scan the media for the CIS */ 675 static int sm_find_cis(struct sm_ftl *ftl) 676 { 677 struct sm_oob oob; 678 int block, boffset; 679 int block_found = 0; 680 int cis_found = 0; 681 682 /* Search for first valid block */ 683 for (block = 0 ; block < ftl->zone_size - ftl->max_lba ; block++) { 684 685 if (sm_read_sector(ftl, 0, block, 0, NULL, &oob)) 686 continue; 687 688 if (!sm_block_valid(&oob)) 689 continue; 690 block_found = 1; 691 break; 692 } 693 694 if (!block_found) 695 return -EIO; 696 697 /* Search for first valid sector in this block */ 698 for (boffset = 0 ; boffset < ftl->block_size; 699 boffset += SM_SECTOR_SIZE) { 700 701 if (sm_read_sector(ftl, 0, block, boffset, NULL, &oob)) 702 continue; 703 704 if (!sm_sector_valid(&oob)) 705 continue; 706 break; 707 } 708 709 if (boffset == ftl->block_size) 710 return -EIO; 711 712 ftl->cis_block = block; 713 ftl->cis_boffset = boffset; 714 ftl->cis_page_offset = 0; 715 716 cis_found = !sm_read_cis(ftl); 717 718 if (!cis_found) { 719 ftl->cis_page_offset = SM_SMALL_PAGE; 720 cis_found = !sm_read_cis(ftl); 721 } 722 723 if (cis_found) { 724 dbg("CIS block found at offset %x", 725 block * ftl->block_size + 726 boffset + ftl->cis_page_offset); 727 return 0; 728 } 729 return -EIO; 730 } 731 732 /* Basic test to determine if underlying mtd device if functional */ 733 static int sm_recheck_media(struct sm_ftl *ftl) 734 { 735 if (sm_read_cis(ftl)) { 736 737 if (!ftl->unstable) { 738 sm_printk("media unstable, not allowing writes"); 739 ftl->unstable = 1; 740 } 741 return -EIO; 742 } 743 return 0; 744 } 745 746 /* Initialize a FTL zone */ 747 static int sm_init_zone(struct sm_ftl *ftl, int zone_num) 748 { 749 struct ftl_zone *zone = &ftl->zones[zone_num]; 750 struct sm_oob oob; 751 uint16_t block; 752 int lba; 753 int i = 0; 754 int len; 755 756 dbg("initializing zone %d", zone_num); 757 758 /* Allocate memory for FTL table */ 759 zone->lba_to_phys_table = kmalloc_array(ftl->max_lba, 2, GFP_KERNEL); 760 761 if (!zone->lba_to_phys_table) 762 return -ENOMEM; 763 memset(zone->lba_to_phys_table, -1, ftl->max_lba * 2); 764 765 766 /* Allocate memory for free sectors FIFO */ 767 if (kfifo_alloc(&zone->free_sectors, ftl->zone_size * 2, GFP_KERNEL)) { 768 kfree(zone->lba_to_phys_table); 769 return -ENOMEM; 770 } 771 772 /* Now scan the zone */ 773 for (block = 0 ; block < ftl->zone_size ; block++) { 774 775 /* Skip blocks till the CIS (including) */ 776 if (zone_num == 0 && block <= ftl->cis_block) 777 continue; 778 779 /* Read the oob of first sector */ 780 if (sm_read_sector(ftl, zone_num, block, 0, NULL, &oob)) 781 return -EIO; 782 783 /* Test to see if block is erased. It is enough to test 784 first sector, because erase happens in one shot */ 785 if (sm_block_erased(&oob)) { 786 kfifo_in(&zone->free_sectors, 787 (unsigned char *)&block, 2); 788 continue; 789 } 790 791 /* If block is marked as bad, skip it */ 792 /* This assumes we can trust first sector*/ 793 /* However the way the block valid status is defined, ensures 794 very low probability of failure here */ 795 if (!sm_block_valid(&oob)) { 796 dbg("PH %04d <-> <marked bad>", block); 797 continue; 798 } 799 800 801 lba = sm_read_lba(&oob); 802 803 /* Invalid LBA means that block is damaged. */ 804 /* We can try to erase it, or mark it as bad, but 805 lets leave that to recovery application */ 806 if (lba == -2 || lba >= ftl->max_lba) { 807 dbg("PH %04d <-> LBA %04d(bad)", block, lba); 808 continue; 809 } 810 811 812 /* If there is no collision, 813 just put the sector in the FTL table */ 814 if (zone->lba_to_phys_table[lba] < 0) { 815 dbg_verbose("PH %04d <-> LBA %04d", block, lba); 816 zone->lba_to_phys_table[lba] = block; 817 continue; 818 } 819 820 sm_printk("collision" 821 " of LBA %d between blocks %d and %d in zone %d", 822 lba, zone->lba_to_phys_table[lba], block, zone_num); 823 824 /* Test that this block is valid*/ 825 if (sm_check_block(ftl, zone_num, block)) 826 continue; 827 828 /* Test now the old block */ 829 if (sm_check_block(ftl, zone_num, 830 zone->lba_to_phys_table[lba])) { 831 zone->lba_to_phys_table[lba] = block; 832 continue; 833 } 834 835 /* If both blocks are valid and share same LBA, it means that 836 they hold different versions of same data. It not 837 known which is more recent, thus just erase one of them 838 */ 839 sm_printk("both blocks are valid, erasing the later"); 840 sm_erase_block(ftl, zone_num, block, 1); 841 } 842 843 dbg("zone initialized"); 844 zone->initialized = 1; 845 846 /* No free sectors, means that the zone is heavily damaged, write won't 847 work, but it can still can be (partially) read */ 848 if (!kfifo_len(&zone->free_sectors)) { 849 sm_printk("no free blocks in zone %d", zone_num); 850 return 0; 851 } 852 853 /* Randomize first block we write to */ 854 get_random_bytes(&i, 2); 855 i %= (kfifo_len(&zone->free_sectors) / 2); 856 857 while (i--) { 858 len = kfifo_out(&zone->free_sectors, 859 (unsigned char *)&block, 2); 860 WARN_ON(len != 2); 861 kfifo_in(&zone->free_sectors, (const unsigned char *)&block, 2); 862 } 863 return 0; 864 } 865 866 /* Get and automatically initialize an FTL mapping for one zone */ 867 static struct ftl_zone *sm_get_zone(struct sm_ftl *ftl, int zone_num) 868 { 869 struct ftl_zone *zone; 870 int error; 871 872 BUG_ON(zone_num >= ftl->zone_count); 873 zone = &ftl->zones[zone_num]; 874 875 if (!zone->initialized) { 876 error = sm_init_zone(ftl, zone_num); 877 878 if (error) 879 return ERR_PTR(error); 880 } 881 return zone; 882 } 883 884 885 /* ----------------- cache handling ------------------------------------------*/ 886 887 /* Initialize the one block cache */ 888 static void sm_cache_init(struct sm_ftl *ftl) 889 { 890 ftl->cache_data_invalid_bitmap = 0xFFFFFFFF; 891 ftl->cache_clean = 1; 892 ftl->cache_zone = -1; 893 ftl->cache_block = -1; 894 /*memset(ftl->cache_data, 0xAA, ftl->block_size);*/ 895 } 896 897 /* Put sector in one block cache */ 898 static void sm_cache_put(struct sm_ftl *ftl, char *buffer, int boffset) 899 { 900 memcpy(ftl->cache_data + boffset, buffer, SM_SECTOR_SIZE); 901 clear_bit(boffset / SM_SECTOR_SIZE, &ftl->cache_data_invalid_bitmap); 902 ftl->cache_clean = 0; 903 } 904 905 /* Read a sector from the cache */ 906 static int sm_cache_get(struct sm_ftl *ftl, char *buffer, int boffset) 907 { 908 if (test_bit(boffset / SM_SECTOR_SIZE, 909 &ftl->cache_data_invalid_bitmap)) 910 return -1; 911 912 memcpy(buffer, ftl->cache_data + boffset, SM_SECTOR_SIZE); 913 return 0; 914 } 915 916 /* Write the cache to hardware */ 917 static int sm_cache_flush(struct sm_ftl *ftl) 918 { 919 struct ftl_zone *zone; 920 921 int sector_num; 922 uint16_t write_sector; 923 int zone_num = ftl->cache_zone; 924 int block_num; 925 926 if (ftl->cache_clean) 927 return 0; 928 929 if (ftl->unstable) 930 return -EIO; 931 932 BUG_ON(zone_num < 0); 933 zone = &ftl->zones[zone_num]; 934 block_num = zone->lba_to_phys_table[ftl->cache_block]; 935 936 937 /* Try to read all unread areas of the cache block*/ 938 for_each_set_bit(sector_num, &ftl->cache_data_invalid_bitmap, 939 ftl->block_size / SM_SECTOR_SIZE) { 940 941 if (!sm_read_sector(ftl, 942 zone_num, block_num, sector_num * SM_SECTOR_SIZE, 943 ftl->cache_data + sector_num * SM_SECTOR_SIZE, NULL)) 944 clear_bit(sector_num, 945 &ftl->cache_data_invalid_bitmap); 946 } 947 restart: 948 949 if (ftl->unstable) 950 return -EIO; 951 952 /* If there are no spare blocks, */ 953 /* we could still continue by erasing/writing the current block, 954 but for such worn out media it doesn't worth the trouble, 955 and the dangers */ 956 if (kfifo_out(&zone->free_sectors, 957 (unsigned char *)&write_sector, 2) != 2) { 958 dbg("no free sectors for write!"); 959 return -EIO; 960 } 961 962 963 if (sm_write_block(ftl, ftl->cache_data, zone_num, write_sector, 964 ftl->cache_block, ftl->cache_data_invalid_bitmap)) 965 goto restart; 966 967 /* Update the FTL table */ 968 zone->lba_to_phys_table[ftl->cache_block] = write_sector; 969 970 /* Write succesfull, so erase and free the old block */ 971 if (block_num > 0) 972 sm_erase_block(ftl, zone_num, block_num, 1); 973 974 sm_cache_init(ftl); 975 return 0; 976 } 977 978 979 /* flush timer, runs a second after last write */ 980 static void sm_cache_flush_timer(struct timer_list *t) 981 { 982 struct sm_ftl *ftl = from_timer(ftl, t, timer); 983 queue_work(cache_flush_workqueue, &ftl->flush_work); 984 } 985 986 /* cache flush work, kicked by timer */ 987 static void sm_cache_flush_work(struct work_struct *work) 988 { 989 struct sm_ftl *ftl = container_of(work, struct sm_ftl, flush_work); 990 mutex_lock(&ftl->mutex); 991 sm_cache_flush(ftl); 992 mutex_unlock(&ftl->mutex); 993 return; 994 } 995 996 /* ---------------- outside interface -------------------------------------- */ 997 998 /* outside interface: read a sector */ 999 static int sm_read(struct mtd_blktrans_dev *dev, 1000 unsigned long sect_no, char *buf) 1001 { 1002 struct sm_ftl *ftl = dev->priv; 1003 struct ftl_zone *zone; 1004 int error = 0, in_cache = 0; 1005 int zone_num, block, boffset; 1006 1007 sm_break_offset(ftl, sect_no << 9, &zone_num, &block, &boffset); 1008 mutex_lock(&ftl->mutex); 1009 1010 1011 zone = sm_get_zone(ftl, zone_num); 1012 if (IS_ERR(zone)) { 1013 error = PTR_ERR(zone); 1014 goto unlock; 1015 } 1016 1017 /* Have to look at cache first */ 1018 if (ftl->cache_zone == zone_num && ftl->cache_block == block) { 1019 in_cache = 1; 1020 if (!sm_cache_get(ftl, buf, boffset)) 1021 goto unlock; 1022 } 1023 1024 /* Translate the block and return if doesn't exist in the table */ 1025 block = zone->lba_to_phys_table[block]; 1026 1027 if (block == -1) { 1028 memset(buf, 0xFF, SM_SECTOR_SIZE); 1029 goto unlock; 1030 } 1031 1032 if (sm_read_sector(ftl, zone_num, block, boffset, buf, NULL)) { 1033 error = -EIO; 1034 goto unlock; 1035 } 1036 1037 if (in_cache) 1038 sm_cache_put(ftl, buf, boffset); 1039 unlock: 1040 mutex_unlock(&ftl->mutex); 1041 return error; 1042 } 1043 1044 /* outside interface: write a sector */ 1045 static int sm_write(struct mtd_blktrans_dev *dev, 1046 unsigned long sec_no, char *buf) 1047 { 1048 struct sm_ftl *ftl = dev->priv; 1049 struct ftl_zone *zone; 1050 int error = 0, zone_num, block, boffset; 1051 1052 BUG_ON(ftl->readonly); 1053 sm_break_offset(ftl, sec_no << 9, &zone_num, &block, &boffset); 1054 1055 /* No need in flush thread running now */ 1056 del_timer(&ftl->timer); 1057 mutex_lock(&ftl->mutex); 1058 1059 zone = sm_get_zone(ftl, zone_num); 1060 if (IS_ERR(zone)) { 1061 error = PTR_ERR(zone); 1062 goto unlock; 1063 } 1064 1065 /* If entry is not in cache, flush it */ 1066 if (ftl->cache_block != block || ftl->cache_zone != zone_num) { 1067 1068 error = sm_cache_flush(ftl); 1069 if (error) 1070 goto unlock; 1071 1072 ftl->cache_block = block; 1073 ftl->cache_zone = zone_num; 1074 } 1075 1076 sm_cache_put(ftl, buf, boffset); 1077 unlock: 1078 mod_timer(&ftl->timer, jiffies + msecs_to_jiffies(cache_timeout)); 1079 mutex_unlock(&ftl->mutex); 1080 return error; 1081 } 1082 1083 /* outside interface: flush everything */ 1084 static int sm_flush(struct mtd_blktrans_dev *dev) 1085 { 1086 struct sm_ftl *ftl = dev->priv; 1087 int retval; 1088 1089 mutex_lock(&ftl->mutex); 1090 retval = sm_cache_flush(ftl); 1091 mutex_unlock(&ftl->mutex); 1092 return retval; 1093 } 1094 1095 /* outside interface: device is released */ 1096 static void sm_release(struct mtd_blktrans_dev *dev) 1097 { 1098 struct sm_ftl *ftl = dev->priv; 1099 1100 mutex_lock(&ftl->mutex); 1101 del_timer_sync(&ftl->timer); 1102 cancel_work_sync(&ftl->flush_work); 1103 sm_cache_flush(ftl); 1104 mutex_unlock(&ftl->mutex); 1105 } 1106 1107 /* outside interface: get geometry */ 1108 static int sm_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo) 1109 { 1110 struct sm_ftl *ftl = dev->priv; 1111 geo->heads = ftl->heads; 1112 geo->sectors = ftl->sectors; 1113 geo->cylinders = ftl->cylinders; 1114 return 0; 1115 } 1116 1117 /* external interface: main initialization function */ 1118 static void sm_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd) 1119 { 1120 struct mtd_blktrans_dev *trans; 1121 struct sm_ftl *ftl; 1122 1123 /* Allocate & initialize our private structure */ 1124 ftl = kzalloc(sizeof(struct sm_ftl), GFP_KERNEL); 1125 if (!ftl) 1126 goto error1; 1127 1128 1129 mutex_init(&ftl->mutex); 1130 timer_setup(&ftl->timer, sm_cache_flush_timer, 0); 1131 INIT_WORK(&ftl->flush_work, sm_cache_flush_work); 1132 1133 /* Read media information */ 1134 if (sm_get_media_info(ftl, mtd)) { 1135 dbg("found unsupported mtd device, aborting"); 1136 goto error2; 1137 } 1138 1139 1140 /* Allocate temporary CIS buffer for read retry support */ 1141 ftl->cis_buffer = kzalloc(SM_SECTOR_SIZE, GFP_KERNEL); 1142 if (!ftl->cis_buffer) 1143 goto error2; 1144 1145 /* Allocate zone array, it will be initialized on demand */ 1146 ftl->zones = kcalloc(ftl->zone_count, sizeof(struct ftl_zone), 1147 GFP_KERNEL); 1148 if (!ftl->zones) 1149 goto error3; 1150 1151 /* Allocate the cache*/ 1152 ftl->cache_data = kzalloc(ftl->block_size, GFP_KERNEL); 1153 1154 if (!ftl->cache_data) 1155 goto error4; 1156 1157 sm_cache_init(ftl); 1158 1159 1160 /* Allocate upper layer structure and initialize it */ 1161 trans = kzalloc(sizeof(struct mtd_blktrans_dev), GFP_KERNEL); 1162 if (!trans) 1163 goto error5; 1164 1165 ftl->trans = trans; 1166 trans->priv = ftl; 1167 1168 trans->tr = tr; 1169 trans->mtd = mtd; 1170 trans->devnum = -1; 1171 trans->size = (ftl->block_size * ftl->max_lba * ftl->zone_count) >> 9; 1172 trans->readonly = ftl->readonly; 1173 1174 if (sm_find_cis(ftl)) { 1175 dbg("CIS not found on mtd device, aborting"); 1176 goto error6; 1177 } 1178 1179 ftl->disk_attributes = sm_create_sysfs_attributes(ftl); 1180 if (!ftl->disk_attributes) 1181 goto error6; 1182 trans->disk_attributes = ftl->disk_attributes; 1183 1184 sm_printk("Found %d MiB xD/SmartMedia FTL on mtd%d", 1185 (int)(mtd->size / (1024 * 1024)), mtd->index); 1186 1187 dbg("FTL layout:"); 1188 dbg("%d zone(s), each consists of %d blocks (+%d spares)", 1189 ftl->zone_count, ftl->max_lba, 1190 ftl->zone_size - ftl->max_lba); 1191 dbg("each block consists of %d bytes", 1192 ftl->block_size); 1193 1194 1195 /* Register device*/ 1196 if (add_mtd_blktrans_dev(trans)) { 1197 dbg("error in mtdblktrans layer"); 1198 goto error6; 1199 } 1200 return; 1201 error6: 1202 kfree(trans); 1203 error5: 1204 kfree(ftl->cache_data); 1205 error4: 1206 kfree(ftl->zones); 1207 error3: 1208 kfree(ftl->cis_buffer); 1209 error2: 1210 kfree(ftl); 1211 error1: 1212 return; 1213 } 1214 1215 /* main interface: device {surprise,} removal */ 1216 static void sm_remove_dev(struct mtd_blktrans_dev *dev) 1217 { 1218 struct sm_ftl *ftl = dev->priv; 1219 int i; 1220 1221 del_mtd_blktrans_dev(dev); 1222 ftl->trans = NULL; 1223 1224 for (i = 0 ; i < ftl->zone_count; i++) { 1225 1226 if (!ftl->zones[i].initialized) 1227 continue; 1228 1229 kfree(ftl->zones[i].lba_to_phys_table); 1230 kfifo_free(&ftl->zones[i].free_sectors); 1231 } 1232 1233 sm_delete_sysfs_attributes(ftl); 1234 kfree(ftl->cis_buffer); 1235 kfree(ftl->zones); 1236 kfree(ftl->cache_data); 1237 kfree(ftl); 1238 } 1239 1240 static struct mtd_blktrans_ops sm_ftl_ops = { 1241 .name = "smblk", 1242 .major = 0, 1243 .part_bits = SM_FTL_PARTN_BITS, 1244 .blksize = SM_SECTOR_SIZE, 1245 .getgeo = sm_getgeo, 1246 1247 .add_mtd = sm_add_mtd, 1248 .remove_dev = sm_remove_dev, 1249 1250 .readsect = sm_read, 1251 .writesect = sm_write, 1252 1253 .flush = sm_flush, 1254 .release = sm_release, 1255 1256 .owner = THIS_MODULE, 1257 }; 1258 1259 static __init int sm_module_init(void) 1260 { 1261 int error = 0; 1262 1263 cache_flush_workqueue = create_freezable_workqueue("smflush"); 1264 if (!cache_flush_workqueue) 1265 return -ENOMEM; 1266 1267 error = register_mtd_blktrans(&sm_ftl_ops); 1268 if (error) 1269 destroy_workqueue(cache_flush_workqueue); 1270 return error; 1271 1272 } 1273 1274 static void __exit sm_module_exit(void) 1275 { 1276 destroy_workqueue(cache_flush_workqueue); 1277 deregister_mtd_blktrans(&sm_ftl_ops); 1278 } 1279 1280 module_init(sm_module_init); 1281 module_exit(sm_module_exit); 1282 1283 MODULE_LICENSE("GPL"); 1284 MODULE_AUTHOR("Maxim Levitsky <maximlevitsky@gmail.com>"); 1285 MODULE_DESCRIPTION("Smartmedia/xD mtd translation layer"); 1286