1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright © 2009 - Maxim Levitsky 4 * SmartMedia/xD translation layer 5 */ 6 7 #include <linux/kernel.h> 8 #include <linux/module.h> 9 #include <linux/random.h> 10 #include <linux/hdreg.h> 11 #include <linux/kthread.h> 12 #include <linux/freezer.h> 13 #include <linux/sysfs.h> 14 #include <linux/bitops.h> 15 #include <linux/slab.h> 16 #include <linux/mtd/nand_ecc.h> 17 #include "nand/raw/sm_common.h" 18 #include "sm_ftl.h" 19 20 21 22 static struct workqueue_struct *cache_flush_workqueue; 23 24 static int cache_timeout = 1000; 25 module_param(cache_timeout, int, S_IRUGO); 26 MODULE_PARM_DESC(cache_timeout, 27 "Timeout (in ms) for cache flush (1000 ms default"); 28 29 static int debug; 30 module_param(debug, int, S_IRUGO | S_IWUSR); 31 MODULE_PARM_DESC(debug, "Debug level (0-2)"); 32 33 34 /* ------------------- sysfs attributes ---------------------------------- */ 35 struct sm_sysfs_attribute { 36 struct device_attribute dev_attr; 37 char *data; 38 int len; 39 }; 40 41 static ssize_t sm_attr_show(struct device *dev, struct device_attribute *attr, 42 char *buf) 43 { 44 struct sm_sysfs_attribute *sm_attr = 45 container_of(attr, struct sm_sysfs_attribute, dev_attr); 46 47 strncpy(buf, sm_attr->data, sm_attr->len); 48 return sm_attr->len; 49 } 50 51 52 #define NUM_ATTRIBUTES 1 53 #define SM_CIS_VENDOR_OFFSET 0x59 54 static struct attribute_group *sm_create_sysfs_attributes(struct sm_ftl *ftl) 55 { 56 struct attribute_group *attr_group; 57 struct attribute **attributes; 58 struct sm_sysfs_attribute *vendor_attribute; 59 char *vendor; 60 61 vendor = kstrndup(ftl->cis_buffer + SM_CIS_VENDOR_OFFSET, 62 SM_SMALL_PAGE - SM_CIS_VENDOR_OFFSET, GFP_KERNEL); 63 if (!vendor) 64 goto error1; 65 66 /* Initialize sysfs attributes */ 67 vendor_attribute = 68 kzalloc(sizeof(struct sm_sysfs_attribute), GFP_KERNEL); 69 if (!vendor_attribute) 70 goto error2; 71 72 sysfs_attr_init(&vendor_attribute->dev_attr.attr); 73 74 vendor_attribute->data = vendor; 75 vendor_attribute->len = strlen(vendor); 76 vendor_attribute->dev_attr.attr.name = "vendor"; 77 vendor_attribute->dev_attr.attr.mode = S_IRUGO; 78 vendor_attribute->dev_attr.show = sm_attr_show; 79 80 81 /* Create array of pointers to the attributes */ 82 attributes = kcalloc(NUM_ATTRIBUTES + 1, sizeof(struct attribute *), 83 GFP_KERNEL); 84 if (!attributes) 85 goto error3; 86 attributes[0] = &vendor_attribute->dev_attr.attr; 87 88 /* Finally create the attribute group */ 89 attr_group = kzalloc(sizeof(struct attribute_group), GFP_KERNEL); 90 if (!attr_group) 91 goto error4; 92 attr_group->attrs = attributes; 93 return attr_group; 94 error4: 95 kfree(attributes); 96 error3: 97 kfree(vendor_attribute); 98 error2: 99 kfree(vendor); 100 error1: 101 return NULL; 102 } 103 104 static void sm_delete_sysfs_attributes(struct sm_ftl *ftl) 105 { 106 struct attribute **attributes = ftl->disk_attributes->attrs; 107 int i; 108 109 for (i = 0; attributes[i] ; i++) { 110 111 struct device_attribute *dev_attr = container_of(attributes[i], 112 struct device_attribute, attr); 113 114 struct sm_sysfs_attribute *sm_attr = 115 container_of(dev_attr, 116 struct sm_sysfs_attribute, dev_attr); 117 118 kfree(sm_attr->data); 119 kfree(sm_attr); 120 } 121 122 kfree(ftl->disk_attributes->attrs); 123 kfree(ftl->disk_attributes); 124 } 125 126 127 /* ----------------------- oob helpers -------------------------------------- */ 128 129 static int sm_get_lba(uint8_t *lba) 130 { 131 /* check fixed bits */ 132 if ((lba[0] & 0xF8) != 0x10) 133 return -2; 134 135 /* check parity - endianness doesn't matter */ 136 if (hweight16(*(uint16_t *)lba) & 1) 137 return -2; 138 139 return (lba[1] >> 1) | ((lba[0] & 0x07) << 7); 140 } 141 142 143 /* 144 * Read LBA associated with block 145 * returns -1, if block is erased 146 * returns -2 if error happens 147 */ 148 static int sm_read_lba(struct sm_oob *oob) 149 { 150 static const uint32_t erased_pattern[4] = { 151 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF }; 152 153 uint16_t lba_test; 154 int lba; 155 156 /* First test for erased block */ 157 if (!memcmp(oob, erased_pattern, SM_OOB_SIZE)) 158 return -1; 159 160 /* Now check is both copies of the LBA differ too much */ 161 lba_test = *(uint16_t *)oob->lba_copy1 ^ *(uint16_t*)oob->lba_copy2; 162 if (lba_test && !is_power_of_2(lba_test)) 163 return -2; 164 165 /* And read it */ 166 lba = sm_get_lba(oob->lba_copy1); 167 168 if (lba == -2) 169 lba = sm_get_lba(oob->lba_copy2); 170 171 return lba; 172 } 173 174 static void sm_write_lba(struct sm_oob *oob, uint16_t lba) 175 { 176 uint8_t tmp[2]; 177 178 WARN_ON(lba >= 1000); 179 180 tmp[0] = 0x10 | ((lba >> 7) & 0x07); 181 tmp[1] = (lba << 1) & 0xFF; 182 183 if (hweight16(*(uint16_t *)tmp) & 0x01) 184 tmp[1] |= 1; 185 186 oob->lba_copy1[0] = oob->lba_copy2[0] = tmp[0]; 187 oob->lba_copy1[1] = oob->lba_copy2[1] = tmp[1]; 188 } 189 190 191 /* Make offset from parts */ 192 static loff_t sm_mkoffset(struct sm_ftl *ftl, int zone, int block, int boffset) 193 { 194 WARN_ON(boffset & (SM_SECTOR_SIZE - 1)); 195 WARN_ON(zone < 0 || zone >= ftl->zone_count); 196 WARN_ON(block >= ftl->zone_size); 197 WARN_ON(boffset >= ftl->block_size); 198 199 if (block == -1) 200 return -1; 201 202 return (zone * SM_MAX_ZONE_SIZE + block) * ftl->block_size + boffset; 203 } 204 205 /* Breaks offset into parts */ 206 static void sm_break_offset(struct sm_ftl *ftl, loff_t loffset, 207 int *zone, int *block, int *boffset) 208 { 209 u64 offset = loffset; 210 *boffset = do_div(offset, ftl->block_size); 211 *block = do_div(offset, ftl->max_lba); 212 *zone = offset >= ftl->zone_count ? -1 : offset; 213 } 214 215 /* ---------------------- low level IO ------------------------------------- */ 216 217 static int sm_correct_sector(uint8_t *buffer, struct sm_oob *oob) 218 { 219 uint8_t ecc[3]; 220 221 __nand_calculate_ecc(buffer, SM_SMALL_PAGE, ecc, 222 IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING_SMC)); 223 if (__nand_correct_data(buffer, ecc, oob->ecc1, SM_SMALL_PAGE, 224 IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING_SMC)) < 0) 225 return -EIO; 226 227 buffer += SM_SMALL_PAGE; 228 229 __nand_calculate_ecc(buffer, SM_SMALL_PAGE, ecc, 230 IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING_SMC)); 231 if (__nand_correct_data(buffer, ecc, oob->ecc2, SM_SMALL_PAGE, 232 IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING_SMC)) < 0) 233 return -EIO; 234 return 0; 235 } 236 237 /* Reads a sector + oob*/ 238 static int sm_read_sector(struct sm_ftl *ftl, 239 int zone, int block, int boffset, 240 uint8_t *buffer, struct sm_oob *oob) 241 { 242 struct mtd_info *mtd = ftl->trans->mtd; 243 struct mtd_oob_ops ops; 244 struct sm_oob tmp_oob; 245 int ret = -EIO; 246 int try = 0; 247 248 /* FTL can contain -1 entries that are by default filled with bits */ 249 if (block == -1) { 250 memset(buffer, 0xFF, SM_SECTOR_SIZE); 251 return 0; 252 } 253 254 /* User might not need the oob, but we do for data verification */ 255 if (!oob) 256 oob = &tmp_oob; 257 258 ops.mode = ftl->smallpagenand ? MTD_OPS_RAW : MTD_OPS_PLACE_OOB; 259 ops.ooboffs = 0; 260 ops.ooblen = SM_OOB_SIZE; 261 ops.oobbuf = (void *)oob; 262 ops.len = SM_SECTOR_SIZE; 263 ops.datbuf = buffer; 264 265 again: 266 if (try++) { 267 /* Avoid infinite recursion on CIS reads, sm_recheck_media 268 won't help anyway */ 269 if (zone == 0 && block == ftl->cis_block && boffset == 270 ftl->cis_boffset) 271 return ret; 272 273 /* Test if media is stable */ 274 if (try == 3 || sm_recheck_media(ftl)) 275 return ret; 276 } 277 278 /* Unfortunately, oob read will _always_ succeed, 279 despite card removal..... */ 280 ret = mtd_read_oob(mtd, sm_mkoffset(ftl, zone, block, boffset), &ops); 281 282 /* Test for unknown errors */ 283 if (ret != 0 && !mtd_is_bitflip_or_eccerr(ret)) { 284 dbg("read of block %d at zone %d, failed due to error (%d)", 285 block, zone, ret); 286 goto again; 287 } 288 289 /* Do a basic test on the oob, to guard against returned garbage */ 290 if (oob->reserved != 0xFFFFFFFF && !is_power_of_2(~oob->reserved)) 291 goto again; 292 293 /* This should never happen, unless there is a bug in the mtd driver */ 294 WARN_ON(ops.oobretlen != SM_OOB_SIZE); 295 WARN_ON(buffer && ops.retlen != SM_SECTOR_SIZE); 296 297 if (!buffer) 298 return 0; 299 300 /* Test if sector marked as bad */ 301 if (!sm_sector_valid(oob)) { 302 dbg("read of block %d at zone %d, failed because it is marked" 303 " as bad" , block, zone); 304 goto again; 305 } 306 307 /* Test ECC*/ 308 if (mtd_is_eccerr(ret) || 309 (ftl->smallpagenand && sm_correct_sector(buffer, oob))) { 310 311 dbg("read of block %d at zone %d, failed due to ECC error", 312 block, zone); 313 goto again; 314 } 315 316 return 0; 317 } 318 319 /* Writes a sector to media */ 320 static int sm_write_sector(struct sm_ftl *ftl, 321 int zone, int block, int boffset, 322 uint8_t *buffer, struct sm_oob *oob) 323 { 324 struct mtd_oob_ops ops; 325 struct mtd_info *mtd = ftl->trans->mtd; 326 int ret; 327 328 BUG_ON(ftl->readonly); 329 330 if (zone == 0 && (block == ftl->cis_block || block == 0)) { 331 dbg("attempted to write the CIS!"); 332 return -EIO; 333 } 334 335 if (ftl->unstable) 336 return -EIO; 337 338 ops.mode = ftl->smallpagenand ? MTD_OPS_RAW : MTD_OPS_PLACE_OOB; 339 ops.len = SM_SECTOR_SIZE; 340 ops.datbuf = buffer; 341 ops.ooboffs = 0; 342 ops.ooblen = SM_OOB_SIZE; 343 ops.oobbuf = (void *)oob; 344 345 ret = mtd_write_oob(mtd, sm_mkoffset(ftl, zone, block, boffset), &ops); 346 347 /* Now we assume that hardware will catch write bitflip errors */ 348 349 if (ret) { 350 dbg("write to block %d at zone %d, failed with error %d", 351 block, zone, ret); 352 353 sm_recheck_media(ftl); 354 return ret; 355 } 356 357 /* This should never happen, unless there is a bug in the driver */ 358 WARN_ON(ops.oobretlen != SM_OOB_SIZE); 359 WARN_ON(buffer && ops.retlen != SM_SECTOR_SIZE); 360 361 return 0; 362 } 363 364 /* ------------------------ block IO ------------------------------------- */ 365 366 /* Write a block using data and lba, and invalid sector bitmap */ 367 static int sm_write_block(struct sm_ftl *ftl, uint8_t *buf, 368 int zone, int block, int lba, 369 unsigned long invalid_bitmap) 370 { 371 struct sm_oob oob; 372 int boffset; 373 int retry = 0; 374 375 /* Initialize the oob with requested values */ 376 memset(&oob, 0xFF, SM_OOB_SIZE); 377 sm_write_lba(&oob, lba); 378 restart: 379 if (ftl->unstable) 380 return -EIO; 381 382 for (boffset = 0; boffset < ftl->block_size; 383 boffset += SM_SECTOR_SIZE) { 384 385 oob.data_status = 0xFF; 386 387 if (test_bit(boffset / SM_SECTOR_SIZE, &invalid_bitmap)) { 388 389 sm_printk("sector %d of block at LBA %d of zone %d" 390 " couldn't be read, marking it as invalid", 391 boffset / SM_SECTOR_SIZE, lba, zone); 392 393 oob.data_status = 0; 394 } 395 396 if (ftl->smallpagenand) { 397 __nand_calculate_ecc(buf + boffset, SM_SMALL_PAGE, 398 oob.ecc1, 399 IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING_SMC)); 400 401 __nand_calculate_ecc(buf + boffset + SM_SMALL_PAGE, 402 SM_SMALL_PAGE, oob.ecc2, 403 IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING_SMC)); 404 } 405 if (!sm_write_sector(ftl, zone, block, boffset, 406 buf + boffset, &oob)) 407 continue; 408 409 if (!retry) { 410 411 /* If write fails. try to erase the block */ 412 /* This is safe, because we never write in blocks 413 that contain valuable data. 414 This is intended to repair block that are marked 415 as erased, but that isn't fully erased*/ 416 417 if (sm_erase_block(ftl, zone, block, 0)) 418 return -EIO; 419 420 retry = 1; 421 goto restart; 422 } else { 423 sm_mark_block_bad(ftl, zone, block); 424 return -EIO; 425 } 426 } 427 return 0; 428 } 429 430 431 /* Mark whole block at offset 'offs' as bad. */ 432 static void sm_mark_block_bad(struct sm_ftl *ftl, int zone, int block) 433 { 434 struct sm_oob oob; 435 int boffset; 436 437 memset(&oob, 0xFF, SM_OOB_SIZE); 438 oob.block_status = 0xF0; 439 440 if (ftl->unstable) 441 return; 442 443 if (sm_recheck_media(ftl)) 444 return; 445 446 sm_printk("marking block %d of zone %d as bad", block, zone); 447 448 /* We aren't checking the return value, because we don't care */ 449 /* This also fails on fake xD cards, but I guess these won't expose 450 any bad blocks till fail completely */ 451 for (boffset = 0; boffset < ftl->block_size; boffset += SM_SECTOR_SIZE) 452 sm_write_sector(ftl, zone, block, boffset, NULL, &oob); 453 } 454 455 /* 456 * Erase a block within a zone 457 * If erase succeeds, it updates free block fifo, otherwise marks block as bad 458 */ 459 static int sm_erase_block(struct sm_ftl *ftl, int zone_num, uint16_t block, 460 int put_free) 461 { 462 struct ftl_zone *zone = &ftl->zones[zone_num]; 463 struct mtd_info *mtd = ftl->trans->mtd; 464 struct erase_info erase; 465 466 erase.addr = sm_mkoffset(ftl, zone_num, block, 0); 467 erase.len = ftl->block_size; 468 469 if (ftl->unstable) 470 return -EIO; 471 472 BUG_ON(ftl->readonly); 473 474 if (zone_num == 0 && (block == ftl->cis_block || block == 0)) { 475 sm_printk("attempted to erase the CIS!"); 476 return -EIO; 477 } 478 479 if (mtd_erase(mtd, &erase)) { 480 sm_printk("erase of block %d in zone %d failed", 481 block, zone_num); 482 goto error; 483 } 484 485 if (put_free) 486 kfifo_in(&zone->free_sectors, 487 (const unsigned char *)&block, sizeof(block)); 488 489 return 0; 490 error: 491 sm_mark_block_bad(ftl, zone_num, block); 492 return -EIO; 493 } 494 495 /* Thoroughly test that block is valid. */ 496 static int sm_check_block(struct sm_ftl *ftl, int zone, int block) 497 { 498 int boffset; 499 struct sm_oob oob; 500 int lbas[] = { -3, 0, 0, 0 }; 501 int i = 0; 502 int test_lba; 503 504 505 /* First just check that block doesn't look fishy */ 506 /* Only blocks that are valid or are sliced in two parts, are 507 accepted */ 508 for (boffset = 0; boffset < ftl->block_size; 509 boffset += SM_SECTOR_SIZE) { 510 511 /* This shouldn't happen anyway */ 512 if (sm_read_sector(ftl, zone, block, boffset, NULL, &oob)) 513 return -2; 514 515 test_lba = sm_read_lba(&oob); 516 517 if (lbas[i] != test_lba) 518 lbas[++i] = test_lba; 519 520 /* If we found three different LBAs, something is fishy */ 521 if (i == 3) 522 return -EIO; 523 } 524 525 /* If the block is sliced (partially erased usually) erase it */ 526 if (i == 2) { 527 sm_erase_block(ftl, zone, block, 1); 528 return 1; 529 } 530 531 return 0; 532 } 533 534 /* ----------------- media scanning --------------------------------- */ 535 static const struct chs_entry chs_table[] = { 536 { 1, 125, 4, 4 }, 537 { 2, 125, 4, 8 }, 538 { 4, 250, 4, 8 }, 539 { 8, 250, 4, 16 }, 540 { 16, 500, 4, 16 }, 541 { 32, 500, 8, 16 }, 542 { 64, 500, 8, 32 }, 543 { 128, 500, 16, 32 }, 544 { 256, 1000, 16, 32 }, 545 { 512, 1015, 32, 63 }, 546 { 1024, 985, 33, 63 }, 547 { 2048, 985, 33, 63 }, 548 { 0 }, 549 }; 550 551 552 static const uint8_t cis_signature[] = { 553 0x01, 0x03, 0xD9, 0x01, 0xFF, 0x18, 0x02, 0xDF, 0x01, 0x20 554 }; 555 /* Find out media parameters. 556 * This ideally has to be based on nand id, but for now device size is enough */ 557 static int sm_get_media_info(struct sm_ftl *ftl, struct mtd_info *mtd) 558 { 559 int i; 560 int size_in_megs = mtd->size / (1024 * 1024); 561 562 ftl->readonly = mtd->type == MTD_ROM; 563 564 /* Manual settings for very old devices */ 565 ftl->zone_count = 1; 566 ftl->smallpagenand = 0; 567 568 switch (size_in_megs) { 569 case 1: 570 /* 1 MiB flash/rom SmartMedia card (256 byte pages)*/ 571 ftl->zone_size = 256; 572 ftl->max_lba = 250; 573 ftl->block_size = 8 * SM_SECTOR_SIZE; 574 ftl->smallpagenand = 1; 575 576 break; 577 case 2: 578 /* 2 MiB flash SmartMedia (256 byte pages)*/ 579 if (mtd->writesize == SM_SMALL_PAGE) { 580 ftl->zone_size = 512; 581 ftl->max_lba = 500; 582 ftl->block_size = 8 * SM_SECTOR_SIZE; 583 ftl->smallpagenand = 1; 584 /* 2 MiB rom SmartMedia */ 585 } else { 586 587 if (!ftl->readonly) 588 return -ENODEV; 589 590 ftl->zone_size = 256; 591 ftl->max_lba = 250; 592 ftl->block_size = 16 * SM_SECTOR_SIZE; 593 } 594 break; 595 case 4: 596 /* 4 MiB flash/rom SmartMedia device */ 597 ftl->zone_size = 512; 598 ftl->max_lba = 500; 599 ftl->block_size = 16 * SM_SECTOR_SIZE; 600 break; 601 case 8: 602 /* 8 MiB flash/rom SmartMedia device */ 603 ftl->zone_size = 1024; 604 ftl->max_lba = 1000; 605 ftl->block_size = 16 * SM_SECTOR_SIZE; 606 } 607 608 /* Minimum xD size is 16MiB. Also, all xD cards have standard zone 609 sizes. SmartMedia cards exist up to 128 MiB and have same layout*/ 610 if (size_in_megs >= 16) { 611 ftl->zone_count = size_in_megs / 16; 612 ftl->zone_size = 1024; 613 ftl->max_lba = 1000; 614 ftl->block_size = 32 * SM_SECTOR_SIZE; 615 } 616 617 /* Test for proper write,erase and oob sizes */ 618 if (mtd->erasesize > ftl->block_size) 619 return -ENODEV; 620 621 if (mtd->writesize > SM_SECTOR_SIZE) 622 return -ENODEV; 623 624 if (ftl->smallpagenand && mtd->oobsize < SM_SMALL_OOB_SIZE) 625 return -ENODEV; 626 627 if (!ftl->smallpagenand && mtd->oobsize < SM_OOB_SIZE) 628 return -ENODEV; 629 630 /* We use OOB */ 631 if (!mtd_has_oob(mtd)) 632 return -ENODEV; 633 634 /* Find geometry information */ 635 for (i = 0 ; i < ARRAY_SIZE(chs_table) ; i++) { 636 if (chs_table[i].size == size_in_megs) { 637 ftl->cylinders = chs_table[i].cyl; 638 ftl->heads = chs_table[i].head; 639 ftl->sectors = chs_table[i].sec; 640 return 0; 641 } 642 } 643 644 sm_printk("media has unknown size : %dMiB", size_in_megs); 645 ftl->cylinders = 985; 646 ftl->heads = 33; 647 ftl->sectors = 63; 648 return 0; 649 } 650 651 /* Validate the CIS */ 652 static int sm_read_cis(struct sm_ftl *ftl) 653 { 654 struct sm_oob oob; 655 656 if (sm_read_sector(ftl, 657 0, ftl->cis_block, ftl->cis_boffset, ftl->cis_buffer, &oob)) 658 return -EIO; 659 660 if (!sm_sector_valid(&oob) || !sm_block_valid(&oob)) 661 return -EIO; 662 663 if (!memcmp(ftl->cis_buffer + ftl->cis_page_offset, 664 cis_signature, sizeof(cis_signature))) { 665 return 0; 666 } 667 668 return -EIO; 669 } 670 671 /* Scan the media for the CIS */ 672 static int sm_find_cis(struct sm_ftl *ftl) 673 { 674 struct sm_oob oob; 675 int block, boffset; 676 int block_found = 0; 677 int cis_found = 0; 678 679 /* Search for first valid block */ 680 for (block = 0 ; block < ftl->zone_size - ftl->max_lba ; block++) { 681 682 if (sm_read_sector(ftl, 0, block, 0, NULL, &oob)) 683 continue; 684 685 if (!sm_block_valid(&oob)) 686 continue; 687 block_found = 1; 688 break; 689 } 690 691 if (!block_found) 692 return -EIO; 693 694 /* Search for first valid sector in this block */ 695 for (boffset = 0 ; boffset < ftl->block_size; 696 boffset += SM_SECTOR_SIZE) { 697 698 if (sm_read_sector(ftl, 0, block, boffset, NULL, &oob)) 699 continue; 700 701 if (!sm_sector_valid(&oob)) 702 continue; 703 break; 704 } 705 706 if (boffset == ftl->block_size) 707 return -EIO; 708 709 ftl->cis_block = block; 710 ftl->cis_boffset = boffset; 711 ftl->cis_page_offset = 0; 712 713 cis_found = !sm_read_cis(ftl); 714 715 if (!cis_found) { 716 ftl->cis_page_offset = SM_SMALL_PAGE; 717 cis_found = !sm_read_cis(ftl); 718 } 719 720 if (cis_found) { 721 dbg("CIS block found at offset %x", 722 block * ftl->block_size + 723 boffset + ftl->cis_page_offset); 724 return 0; 725 } 726 return -EIO; 727 } 728 729 /* Basic test to determine if underlying mtd device if functional */ 730 static int sm_recheck_media(struct sm_ftl *ftl) 731 { 732 if (sm_read_cis(ftl)) { 733 734 if (!ftl->unstable) { 735 sm_printk("media unstable, not allowing writes"); 736 ftl->unstable = 1; 737 } 738 return -EIO; 739 } 740 return 0; 741 } 742 743 /* Initialize a FTL zone */ 744 static int sm_init_zone(struct sm_ftl *ftl, int zone_num) 745 { 746 struct ftl_zone *zone = &ftl->zones[zone_num]; 747 struct sm_oob oob; 748 uint16_t block; 749 int lba; 750 int i = 0; 751 int len; 752 753 dbg("initializing zone %d", zone_num); 754 755 /* Allocate memory for FTL table */ 756 zone->lba_to_phys_table = kmalloc_array(ftl->max_lba, 2, GFP_KERNEL); 757 758 if (!zone->lba_to_phys_table) 759 return -ENOMEM; 760 memset(zone->lba_to_phys_table, -1, ftl->max_lba * 2); 761 762 763 /* Allocate memory for free sectors FIFO */ 764 if (kfifo_alloc(&zone->free_sectors, ftl->zone_size * 2, GFP_KERNEL)) { 765 kfree(zone->lba_to_phys_table); 766 return -ENOMEM; 767 } 768 769 /* Now scan the zone */ 770 for (block = 0 ; block < ftl->zone_size ; block++) { 771 772 /* Skip blocks till the CIS (including) */ 773 if (zone_num == 0 && block <= ftl->cis_block) 774 continue; 775 776 /* Read the oob of first sector */ 777 if (sm_read_sector(ftl, zone_num, block, 0, NULL, &oob)) { 778 kfifo_free(&zone->free_sectors); 779 kfree(zone->lba_to_phys_table); 780 return -EIO; 781 } 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