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