diff options
Diffstat (limited to 'drivers/mtd/sm_ftl.c')
| -rw-r--r-- | drivers/mtd/sm_ftl.c | 1279 |
1 files changed, 1279 insertions, 0 deletions
diff --git a/drivers/mtd/sm_ftl.c b/drivers/mtd/sm_ftl.c new file mode 100644 index 000000000..f3bd86e13 --- /dev/null +++ b/drivers/mtd/sm_ftl.c @@ -0,0 +1,1279 @@ +/* + * Copyright © 2009 - Maxim Levitsky + * SmartMedia/xD translation layer + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/random.h> +#include <linux/hdreg.h> +#include <linux/kthread.h> +#include <linux/freezer.h> +#include <linux/sysfs.h> +#include <linux/bitops.h> +#include <linux/slab.h> +#include <linux/mtd/nand_ecc.h> +#include "nand/raw/sm_common.h" +#include "sm_ftl.h" + + + +static struct workqueue_struct *cache_flush_workqueue; + +static int cache_timeout = 1000; +module_param(cache_timeout, int, S_IRUGO); +MODULE_PARM_DESC(cache_timeout, + "Timeout (in ms) for cache flush (1000 ms default"); + +static int debug; +module_param(debug, int, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(debug, "Debug level (0-2)"); + + +/* ------------------- sysfs attributes ---------------------------------- */ +struct sm_sysfs_attribute { + struct device_attribute dev_attr; + char *data; + int len; +}; + +static ssize_t sm_attr_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct sm_sysfs_attribute *sm_attr = + container_of(attr, struct sm_sysfs_attribute, dev_attr); + + strncpy(buf, sm_attr->data, sm_attr->len); + return sm_attr->len; +} + + +#define NUM_ATTRIBUTES 1 +#define SM_CIS_VENDOR_OFFSET 0x59 +static struct attribute_group *sm_create_sysfs_attributes(struct sm_ftl *ftl) +{ + struct attribute_group *attr_group; + struct attribute **attributes; + struct sm_sysfs_attribute *vendor_attribute; + char *vendor; + + vendor = kstrndup(ftl->cis_buffer + SM_CIS_VENDOR_OFFSET, + SM_SMALL_PAGE - SM_CIS_VENDOR_OFFSET, GFP_KERNEL); + if (!vendor) + goto error1; + + /* Initialize sysfs attributes */ + vendor_attribute = + kzalloc(sizeof(struct sm_sysfs_attribute), GFP_KERNEL); + if (!vendor_attribute) + goto error2; + + sysfs_attr_init(&vendor_attribute->dev_attr.attr); + + vendor_attribute->data = vendor; + vendor_attribute->len = strlen(vendor); + vendor_attribute->dev_attr.attr.name = "vendor"; + vendor_attribute->dev_attr.attr.mode = S_IRUGO; + vendor_attribute->dev_attr.show = sm_attr_show; + + + /* Create array of pointers to the attributes */ + attributes = kcalloc(NUM_ATTRIBUTES + 1, sizeof(struct attribute *), + GFP_KERNEL); + if (!attributes) + goto error3; + attributes[0] = &vendor_attribute->dev_attr.attr; + + /* Finally create the attribute group */ + attr_group = kzalloc(sizeof(struct attribute_group), GFP_KERNEL); + if (!attr_group) + goto error4; + attr_group->attrs = attributes; + return attr_group; +error4: + kfree(attributes); +error3: + kfree(vendor_attribute); +error2: + kfree(vendor); +error1: + return NULL; +} + +static void sm_delete_sysfs_attributes(struct sm_ftl *ftl) +{ + struct attribute **attributes = ftl->disk_attributes->attrs; + int i; + + for (i = 0; attributes[i] ; i++) { + + struct device_attribute *dev_attr = container_of(attributes[i], + struct device_attribute, attr); + + struct sm_sysfs_attribute *sm_attr = + container_of(dev_attr, + struct sm_sysfs_attribute, dev_attr); + + kfree(sm_attr->data); + kfree(sm_attr); + } + + kfree(ftl->disk_attributes->attrs); + kfree(ftl->disk_attributes); +} + + +/* ----------------------- oob helpers -------------------------------------- */ + +static int sm_get_lba(uint8_t *lba) +{ + /* check fixed bits */ + if ((lba[0] & 0xF8) != 0x10) + return -2; + + /* check parity - endianness doesn't matter */ + if (hweight16(*(uint16_t *)lba) & 1) + return -2; + + return (lba[1] >> 1) | ((lba[0] & 0x07) << 7); +} + + +/* + * Read LBA associated with block + * returns -1, if block is erased + * returns -2 if error happens + */ +static int sm_read_lba(struct sm_oob *oob) +{ + static const uint32_t erased_pattern[4] = { + 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF }; + + uint16_t lba_test; + int lba; + + /* First test for erased block */ + if (!memcmp(oob, erased_pattern, SM_OOB_SIZE)) + return -1; + + /* Now check is both copies of the LBA differ too much */ + lba_test = *(uint16_t *)oob->lba_copy1 ^ *(uint16_t*)oob->lba_copy2; + if (lba_test && !is_power_of_2(lba_test)) + return -2; + + /* And read it */ + lba = sm_get_lba(oob->lba_copy1); + + if (lba == -2) + lba = sm_get_lba(oob->lba_copy2); + + return lba; +} + +static void sm_write_lba(struct sm_oob *oob, uint16_t lba) +{ + uint8_t tmp[2]; + + WARN_ON(lba >= 1000); + + tmp[0] = 0x10 | ((lba >> 7) & 0x07); + tmp[1] = (lba << 1) & 0xFF; + + if (hweight16(*(uint16_t *)tmp) & 0x01) + tmp[1] |= 1; + + oob->lba_copy1[0] = oob->lba_copy2[0] = tmp[0]; + oob->lba_copy1[1] = oob->lba_copy2[1] = tmp[1]; +} + + +/* Make offset from parts */ +static loff_t sm_mkoffset(struct sm_ftl *ftl, int zone, int block, int boffset) +{ + WARN_ON(boffset & (SM_SECTOR_SIZE - 1)); + WARN_ON(zone < 0 || zone >= ftl->zone_count); + WARN_ON(block >= ftl->zone_size); + WARN_ON(boffset >= ftl->block_size); + + if (block == -1) + return -1; + + return (zone * SM_MAX_ZONE_SIZE + block) * ftl->block_size + boffset; +} + +/* Breaks offset into parts */ +static void sm_break_offset(struct sm_ftl *ftl, loff_t loffset, + int *zone, int *block, int *boffset) +{ + u64 offset = loffset; + *boffset = do_div(offset, ftl->block_size); + *block = do_div(offset, ftl->max_lba); + *zone = offset >= ftl->zone_count ? -1 : offset; +} + +/* ---------------------- low level IO ------------------------------------- */ + +static int sm_correct_sector(uint8_t *buffer, struct sm_oob *oob) +{ + uint8_t ecc[3]; + + __nand_calculate_ecc(buffer, SM_SMALL_PAGE, ecc); + if (__nand_correct_data(buffer, ecc, oob->ecc1, SM_SMALL_PAGE) < 0) + return -EIO; + + buffer += SM_SMALL_PAGE; + + __nand_calculate_ecc(buffer, SM_SMALL_PAGE, ecc); + if (__nand_correct_data(buffer, ecc, oob->ecc2, SM_SMALL_PAGE) < 0) + return -EIO; + return 0; +} + +/* Reads a sector + oob*/ +static int sm_read_sector(struct sm_ftl *ftl, + int zone, int block, int boffset, + uint8_t *buffer, struct sm_oob *oob) +{ + struct mtd_info *mtd = ftl->trans->mtd; + struct mtd_oob_ops ops; + struct sm_oob tmp_oob; + int ret = -EIO; + int try = 0; + + /* FTL can contain -1 entries that are by default filled with bits */ + if (block == -1) { + memset(buffer, 0xFF, SM_SECTOR_SIZE); + return 0; + } + + /* User might not need the oob, but we do for data verification */ + if (!oob) + oob = &tmp_oob; + + ops.mode = ftl->smallpagenand ? MTD_OPS_RAW : MTD_OPS_PLACE_OOB; + ops.ooboffs = 0; + ops.ooblen = SM_OOB_SIZE; + ops.oobbuf = (void *)oob; + ops.len = SM_SECTOR_SIZE; + ops.datbuf = buffer; + +again: + if (try++) { + /* Avoid infinite recursion on CIS reads, sm_recheck_media + won't help anyway */ + if (zone == 0 && block == ftl->cis_block && boffset == + ftl->cis_boffset) + return ret; + + /* Test if media is stable */ + if (try == 3 || sm_recheck_media(ftl)) + return ret; + } + + /* Unfortunately, oob read will _always_ succeed, + despite card removal..... */ + ret = mtd_read_oob(mtd, sm_mkoffset(ftl, zone, block, boffset), &ops); + + /* Test for unknown errors */ + if (ret != 0 && !mtd_is_bitflip_or_eccerr(ret)) { + dbg("read of block %d at zone %d, failed due to error (%d)", + block, zone, ret); + goto again; + } + + /* Do a basic test on the oob, to guard against returned garbage */ + if (oob->reserved != 0xFFFFFFFF && !is_power_of_2(~oob->reserved)) + goto again; + + /* This should never happen, unless there is a bug in the mtd driver */ + WARN_ON(ops.oobretlen != SM_OOB_SIZE); + WARN_ON(buffer && ops.retlen != SM_SECTOR_SIZE); + + if (!buffer) + return 0; + + /* Test if sector marked as bad */ + if (!sm_sector_valid(oob)) { + dbg("read of block %d at zone %d, failed because it is marked" + " as bad" , block, zone); + goto again; + } + + /* Test ECC*/ + if (mtd_is_eccerr(ret) || + (ftl->smallpagenand && sm_correct_sector(buffer, oob))) { + + dbg("read of block %d at zone %d, failed due to ECC error", + block, zone); + goto again; + } + + return 0; +} + +/* Writes a sector to media */ +static int sm_write_sector(struct sm_ftl *ftl, + int zone, int block, int boffset, + uint8_t *buffer, struct sm_oob *oob) +{ + struct mtd_oob_ops ops; + struct mtd_info *mtd = ftl->trans->mtd; + int ret; + + BUG_ON(ftl->readonly); + + if (zone == 0 && (block == ftl->cis_block || block == 0)) { + dbg("attempted to write the CIS!"); + return -EIO; + } + + if (ftl->unstable) + return -EIO; + + ops.mode = ftl->smallpagenand ? MTD_OPS_RAW : MTD_OPS_PLACE_OOB; + ops.len = SM_SECTOR_SIZE; + ops.datbuf = buffer; + ops.ooboffs = 0; + ops.ooblen = SM_OOB_SIZE; + ops.oobbuf = (void *)oob; + + ret = mtd_write_oob(mtd, sm_mkoffset(ftl, zone, block, boffset), &ops); + + /* Now we assume that hardware will catch write bitflip errors */ + + if (ret) { + dbg("write to block %d at zone %d, failed with error %d", + block, zone, ret); + + sm_recheck_media(ftl); + return ret; + } + + /* This should never happen, unless there is a bug in the driver */ + WARN_ON(ops.oobretlen != SM_OOB_SIZE); + WARN_ON(buffer && ops.retlen != SM_SECTOR_SIZE); + + return 0; +} + +/* ------------------------ block IO ------------------------------------- */ + +/* Write a block using data and lba, and invalid sector bitmap */ +static int sm_write_block(struct sm_ftl *ftl, uint8_t *buf, + int zone, int block, int lba, + unsigned long invalid_bitmap) +{ + struct sm_oob oob; + int boffset; + int retry = 0; + + /* Initialize the oob with requested values */ + memset(&oob, 0xFF, SM_OOB_SIZE); + sm_write_lba(&oob, lba); +restart: + if (ftl->unstable) + return -EIO; + + for (boffset = 0; boffset < ftl->block_size; + boffset += SM_SECTOR_SIZE) { + + oob.data_status = 0xFF; + + if (test_bit(boffset / SM_SECTOR_SIZE, &invalid_bitmap)) { + + sm_printk("sector %d of block at LBA %d of zone %d" + " couldn't be read, marking it as invalid", + boffset / SM_SECTOR_SIZE, lba, zone); + + oob.data_status = 0; + } + + if (ftl->smallpagenand) { + __nand_calculate_ecc(buf + boffset, + SM_SMALL_PAGE, oob.ecc1); + + __nand_calculate_ecc(buf + boffset + SM_SMALL_PAGE, + SM_SMALL_PAGE, oob.ecc2); + } + if (!sm_write_sector(ftl, zone, block, boffset, + buf + boffset, &oob)) + continue; + + if (!retry) { + + /* If write fails. try to erase the block */ + /* This is safe, because we never write in blocks + that contain valuable data. + This is intended to repair block that are marked + as erased, but that isn't fully erased*/ + + if (sm_erase_block(ftl, zone, block, 0)) + return -EIO; + + retry = 1; + goto restart; + } else { + sm_mark_block_bad(ftl, zone, block); + return -EIO; + } + } + return 0; +} + + +/* Mark whole block at offset 'offs' as bad. */ +static void sm_mark_block_bad(struct sm_ftl *ftl, int zone, int block) +{ + struct sm_oob oob; + int boffset; + + memset(&oob, 0xFF, SM_OOB_SIZE); + oob.block_status = 0xF0; + + if (ftl->unstable) + return; + + if (sm_recheck_media(ftl)) + return; + + sm_printk("marking block %d of zone %d as bad", block, zone); + + /* We aren't checking the return value, because we don't care */ + /* This also fails on fake xD cards, but I guess these won't expose + any bad blocks till fail completely */ + for (boffset = 0; boffset < ftl->block_size; boffset += SM_SECTOR_SIZE) + sm_write_sector(ftl, zone, block, boffset, NULL, &oob); +} + +/* + * Erase a block within a zone + * If erase succeeds, it updates free block fifo, otherwise marks block as bad + */ +static int sm_erase_block(struct sm_ftl *ftl, int zone_num, uint16_t block, + int put_free) +{ + struct ftl_zone *zone = &ftl->zones[zone_num]; + struct mtd_info *mtd = ftl->trans->mtd; + struct erase_info erase; + + erase.addr = sm_mkoffset(ftl, zone_num, block, 0); + erase.len = ftl->block_size; + + if (ftl->unstable) + return -EIO; + + BUG_ON(ftl->readonly); + + if (zone_num == 0 && (block == ftl->cis_block || block == 0)) { + sm_printk("attempted to erase the CIS!"); + return -EIO; + } + + if (mtd_erase(mtd, &erase)) { + sm_printk("erase of block %d in zone %d failed", + block, zone_num); + goto error; + } + + if (put_free) + kfifo_in(&zone->free_sectors, + (const unsigned char *)&block, sizeof(block)); + + return 0; +error: + sm_mark_block_bad(ftl, zone_num, block); + return -EIO; +} + +/* Thoroughly test that block is valid. */ +static int sm_check_block(struct sm_ftl *ftl, int zone, int block) +{ + int boffset; + struct sm_oob oob; + int lbas[] = { -3, 0, 0, 0 }; + int i = 0; + int test_lba; + + + /* First just check that block doesn't look fishy */ + /* Only blocks that are valid or are sliced in two parts, are + accepted */ + for (boffset = 0; boffset < ftl->block_size; + boffset += SM_SECTOR_SIZE) { + + /* This shouldn't happen anyway */ + if (sm_read_sector(ftl, zone, block, boffset, NULL, &oob)) + return -2; + + test_lba = sm_read_lba(&oob); + + if (lbas[i] != test_lba) + lbas[++i] = test_lba; + + /* If we found three different LBAs, something is fishy */ + if (i == 3) + return -EIO; + } + + /* If the block is sliced (partially erased usually) erase it */ + if (i == 2) { + sm_erase_block(ftl, zone, block, 1); + return 1; + } + + return 0; +} + +/* ----------------- media scanning --------------------------------- */ +static const struct chs_entry chs_table[] = { + { 1, 125, 4, 4 }, + { 2, 125, 4, 8 }, + { 4, 250, 4, 8 }, + { 8, 250, 4, 16 }, + { 16, 500, 4, 16 }, + { 32, 500, 8, 16 }, + { 64, 500, 8, 32 }, + { 128, 500, 16, 32 }, + { 256, 1000, 16, 32 }, + { 512, 1015, 32, 63 }, + { 1024, 985, 33, 63 }, + { 2048, 985, 33, 63 }, + { 0 }, +}; + + +static const uint8_t cis_signature[] = { + 0x01, 0x03, 0xD9, 0x01, 0xFF, 0x18, 0x02, 0xDF, 0x01, 0x20 +}; +/* Find out media parameters. + * This ideally has to be based on nand id, but for now device size is enough */ +static int sm_get_media_info(struct sm_ftl *ftl, struct mtd_info *mtd) +{ + int i; + int size_in_megs = mtd->size / (1024 * 1024); + + ftl->readonly = mtd->type == MTD_ROM; + + /* Manual settings for very old devices */ + ftl->zone_count = 1; + ftl->smallpagenand = 0; + + switch (size_in_megs) { + case 1: + /* 1 MiB flash/rom SmartMedia card (256 byte pages)*/ + ftl->zone_size = 256; + ftl->max_lba = 250; + ftl->block_size = 8 * SM_SECTOR_SIZE; + ftl->smallpagenand = 1; + + break; + case 2: + /* 2 MiB flash SmartMedia (256 byte pages)*/ + if (mtd->writesize == SM_SMALL_PAGE) { + ftl->zone_size = 512; + ftl->max_lba = 500; + ftl->block_size = 8 * SM_SECTOR_SIZE; + ftl->smallpagenand = 1; + /* 2 MiB rom SmartMedia */ + } else { + + if (!ftl->readonly) + return -ENODEV; + + ftl->zone_size = 256; + ftl->max_lba = 250; + ftl->block_size = 16 * SM_SECTOR_SIZE; + } + break; + case 4: + /* 4 MiB flash/rom SmartMedia device */ + ftl->zone_size = 512; + ftl->max_lba = 500; + ftl->block_size = 16 * SM_SECTOR_SIZE; + break; + case 8: + /* 8 MiB flash/rom SmartMedia device */ + ftl->zone_size = 1024; + ftl->max_lba = 1000; + ftl->block_size = 16 * SM_SECTOR_SIZE; + } + + /* Minimum xD size is 16MiB. Also, all xD cards have standard zone + sizes. SmartMedia cards exist up to 128 MiB and have same layout*/ + if (size_in_megs >= 16) { + ftl->zone_count = size_in_megs / 16; + ftl->zone_size = 1024; + ftl->max_lba = 1000; + ftl->block_size = 32 * SM_SECTOR_SIZE; + } + + /* Test for proper write,erase and oob sizes */ + if (mtd->erasesize > ftl->block_size) + return -ENODEV; + + if (mtd->writesize > SM_SECTOR_SIZE) + return -ENODEV; + + if (ftl->smallpagenand && mtd->oobsize < SM_SMALL_OOB_SIZE) + return -ENODEV; + + if (!ftl->smallpagenand && mtd->oobsize < SM_OOB_SIZE) + return -ENODEV; + + /* We use OOB */ + if (!mtd_has_oob(mtd)) + return -ENODEV; + + /* Find geometry information */ + for (i = 0 ; i < ARRAY_SIZE(chs_table) ; i++) { + if (chs_table[i].size == size_in_megs) { + ftl->cylinders = chs_table[i].cyl; + ftl->heads = chs_table[i].head; + ftl->sectors = chs_table[i].sec; + return 0; + } + } + + sm_printk("media has unknown size : %dMiB", size_in_megs); + ftl->cylinders = 985; + ftl->heads = 33; + ftl->sectors = 63; + return 0; +} + +/* Validate the CIS */ +static int sm_read_cis(struct sm_ftl *ftl) +{ + struct sm_oob oob; + + if (sm_read_sector(ftl, + 0, ftl->cis_block, ftl->cis_boffset, ftl->cis_buffer, &oob)) + return -EIO; + + if (!sm_sector_valid(&oob) || !sm_block_valid(&oob)) + return -EIO; + + if (!memcmp(ftl->cis_buffer + ftl->cis_page_offset, + cis_signature, sizeof(cis_signature))) { + return 0; + } + + return -EIO; +} + +/* Scan the media for the CIS */ +static int sm_find_cis(struct sm_ftl *ftl) +{ + struct sm_oob oob; + int block, boffset; + int block_found = 0; + int cis_found = 0; + + /* Search for first valid block */ + for (block = 0 ; block < ftl->zone_size - ftl->max_lba ; block++) { + + if (sm_read_sector(ftl, 0, block, 0, NULL, &oob)) + continue; + + if (!sm_block_valid(&oob)) + continue; + block_found = 1; + break; + } + + if (!block_found) + return -EIO; + + /* Search for first valid sector in this block */ + for (boffset = 0 ; boffset < ftl->block_size; + boffset += SM_SECTOR_SIZE) { + + if (sm_read_sector(ftl, 0, block, boffset, NULL, &oob)) + continue; + + if (!sm_sector_valid(&oob)) + continue; + break; + } + + if (boffset == ftl->block_size) + return -EIO; + + ftl->cis_block = block; + ftl->cis_boffset = boffset; + ftl->cis_page_offset = 0; + + cis_found = !sm_read_cis(ftl); + + if (!cis_found) { + ftl->cis_page_offset = SM_SMALL_PAGE; + cis_found = !sm_read_cis(ftl); + } + + if (cis_found) { + dbg("CIS block found at offset %x", + block * ftl->block_size + + boffset + ftl->cis_page_offset); + return 0; + } + return -EIO; +} + +/* Basic test to determine if underlying mtd device if functional */ +static int sm_recheck_media(struct sm_ftl *ftl) +{ + if (sm_read_cis(ftl)) { + + if (!ftl->unstable) { + sm_printk("media unstable, not allowing writes"); + ftl->unstable = 1; + } + return -EIO; + } + return 0; +} + +/* Initialize a FTL zone */ +static int sm_init_zone(struct sm_ftl *ftl, int zone_num) +{ + struct ftl_zone *zone = &ftl->zones[zone_num]; + struct sm_oob oob; + uint16_t block; + int lba; + int i = 0; + int len; + + dbg("initializing zone %d", zone_num); + + /* Allocate memory for FTL table */ + zone->lba_to_phys_table = kmalloc_array(ftl->max_lba, 2, GFP_KERNEL); + + if (!zone->lba_to_phys_table) + return -ENOMEM; + memset(zone->lba_to_phys_table, -1, ftl->max_lba * 2); + + + /* Allocate memory for free sectors FIFO */ + if (kfifo_alloc(&zone->free_sectors, ftl->zone_size * 2, GFP_KERNEL)) { + kfree(zone->lba_to_phys_table); + return -ENOMEM; + } + + /* Now scan the zone */ + for (block = 0 ; block < ftl->zone_size ; block++) { + + /* Skip blocks till the CIS (including) */ + if (zone_num == 0 && block <= ftl->cis_block) + continue; + + /* Read the oob of first sector */ + if (sm_read_sector(ftl, zone_num, block, 0, NULL, &oob)) + return -EIO; + + /* Test to see if block is erased. It is enough to test + first sector, because erase happens in one shot */ + if (sm_block_erased(&oob)) { + kfifo_in(&zone->free_sectors, + (unsigned char *)&block, 2); + continue; + } + + /* If block is marked as bad, skip it */ + /* This assumes we can trust first sector*/ + /* However the way the block valid status is defined, ensures + very low probability of failure here */ + if (!sm_block_valid(&oob)) { + dbg("PH %04d <-> <marked bad>", block); + continue; + } + + + lba = sm_read_lba(&oob); + + /* Invalid LBA means that block is damaged. */ + /* We can try to erase it, or mark it as bad, but + lets leave that to recovery application */ + if (lba == -2 || lba >= ftl->max_lba) { + dbg("PH %04d <-> LBA %04d(bad)", block, lba); + continue; + } + + + /* If there is no collision, + just put the sector in the FTL table */ + if (zone->lba_to_phys_table[lba] < 0) { + dbg_verbose("PH %04d <-> LBA %04d", block, lba); + zone->lba_to_phys_table[lba] = block; + continue; + } + + sm_printk("collision" + " of LBA %d between blocks %d and %d in zone %d", + lba, zone->lba_to_phys_table[lba], block, zone_num); + + /* Test that this block is valid*/ + if (sm_check_block(ftl, zone_num, block)) + continue; + + /* Test now the old block */ + if (sm_check_block(ftl, zone_num, + zone->lba_to_phys_table[lba])) { + zone->lba_to_phys_table[lba] = block; + continue; + } + + /* If both blocks are valid and share same LBA, it means that + they hold different versions of same data. It not + known which is more recent, thus just erase one of them + */ + sm_printk("both blocks are valid, erasing the later"); + sm_erase_block(ftl, zone_num, block, 1); + } + + dbg("zone initialized"); + zone->initialized = 1; + + /* No free sectors, means that the zone is heavily damaged, write won't + work, but it can still can be (partially) read */ + if (!kfifo_len(&zone->free_sectors)) { + sm_printk("no free blocks in zone %d", zone_num); + return 0; + } + + /* Randomize first block we write to */ + get_random_bytes(&i, 2); + i %= (kfifo_len(&zone->free_sectors) / 2); + + while (i--) { + len = kfifo_out(&zone->free_sectors, + (unsigned char *)&block, 2); + WARN_ON(len != 2); + kfifo_in(&zone->free_sectors, (const unsigned char *)&block, 2); + } + return 0; +} + +/* Get and automatically initialize an FTL mapping for one zone */ +static struct ftl_zone *sm_get_zone(struct sm_ftl *ftl, int zone_num) +{ + struct ftl_zone *zone; + int error; + + BUG_ON(zone_num >= ftl->zone_count); + zone = &ftl->zones[zone_num]; + + if (!zone->initialized) { + error = sm_init_zone(ftl, zone_num); + + if (error) + return ERR_PTR(error); + } + return zone; +} + + +/* ----------------- cache handling ------------------------------------------*/ + +/* Initialize the one block cache */ +static void sm_cache_init(struct sm_ftl *ftl) +{ + ftl->cache_data_invalid_bitmap = 0xFFFFFFFF; + ftl->cache_clean = 1; + ftl->cache_zone = -1; + ftl->cache_block = -1; + /*memset(ftl->cache_data, 0xAA, ftl->block_size);*/ +} + +/* Put sector in one block cache */ +static void sm_cache_put(struct sm_ftl *ftl, char *buffer, int boffset) +{ + memcpy(ftl->cache_data + boffset, buffer, SM_SECTOR_SIZE); + clear_bit(boffset / SM_SECTOR_SIZE, &ftl->cache_data_invalid_bitmap); + ftl->cache_clean = 0; +} + +/* Read a sector from the cache */ +static int sm_cache_get(struct sm_ftl *ftl, char *buffer, int boffset) +{ + if (test_bit(boffset / SM_SECTOR_SIZE, + &ftl->cache_data_invalid_bitmap)) + return -1; + + memcpy(buffer, ftl->cache_data + boffset, SM_SECTOR_SIZE); + return 0; +} + +/* Write the cache to hardware */ +static int sm_cache_flush(struct sm_ftl *ftl) +{ + struct ftl_zone *zone; + + int sector_num; + uint16_t write_sector; + int zone_num = ftl->cache_zone; + int block_num; + + if (ftl->cache_clean) + return 0; + + if (ftl->unstable) + return -EIO; + + BUG_ON(zone_num < 0); + zone = &ftl->zones[zone_num]; + block_num = zone->lba_to_phys_table[ftl->cache_block]; + + + /* Try to read all unread areas of the cache block*/ + for_each_set_bit(sector_num, &ftl->cache_data_invalid_bitmap, + ftl->block_size / SM_SECTOR_SIZE) { + + if (!sm_read_sector(ftl, + zone_num, block_num, sector_num * SM_SECTOR_SIZE, + ftl->cache_data + sector_num * SM_SECTOR_SIZE, NULL)) + clear_bit(sector_num, + &ftl->cache_data_invalid_bitmap); + } +restart: + + if (ftl->unstable) + return -EIO; + + /* If there are no spare blocks, */ + /* we could still continue by erasing/writing the current block, + but for such worn out media it doesn't worth the trouble, + and the dangers */ + if (kfifo_out(&zone->free_sectors, + (unsigned char *)&write_sector, 2) != 2) { + dbg("no free sectors for write!"); + return -EIO; + } + + + if (sm_write_block(ftl, ftl->cache_data, zone_num, write_sector, + ftl->cache_block, ftl->cache_data_invalid_bitmap)) + goto restart; + + /* Update the FTL table */ + zone->lba_to_phys_table[ftl->cache_block] = write_sector; + + /* Write succesfull, so erase and free the old block */ + if (block_num > 0) + sm_erase_block(ftl, zone_num, block_num, 1); + + sm_cache_init(ftl); + return 0; +} + + +/* flush timer, runs a second after last write */ +static void sm_cache_flush_timer(struct timer_list *t) +{ + struct sm_ftl *ftl = from_timer(ftl, t, timer); + queue_work(cache_flush_workqueue, &ftl->flush_work); +} + +/* cache flush work, kicked by timer */ +static void sm_cache_flush_work(struct work_struct *work) +{ + struct sm_ftl *ftl = container_of(work, struct sm_ftl, flush_work); + mutex_lock(&ftl->mutex); + sm_cache_flush(ftl); + mutex_unlock(&ftl->mutex); + return; +} + +/* ---------------- outside interface -------------------------------------- */ + +/* outside interface: read a sector */ +static int sm_read(struct mtd_blktrans_dev *dev, + unsigned long sect_no, char *buf) +{ + struct sm_ftl *ftl = dev->priv; + struct ftl_zone *zone; + int error = 0, in_cache = 0; + int zone_num, block, boffset; + + sm_break_offset(ftl, sect_no << 9, &zone_num, &block, &boffset); + mutex_lock(&ftl->mutex); + + + zone = sm_get_zone(ftl, zone_num); + if (IS_ERR(zone)) { + error = PTR_ERR(zone); + goto unlock; + } + + /* Have to look at cache first */ + if (ftl->cache_zone == zone_num && ftl->cache_block == block) { + in_cache = 1; + if (!sm_cache_get(ftl, buf, boffset)) + goto unlock; + } + + /* Translate the block and return if doesn't exist in the table */ + block = zone->lba_to_phys_table[block]; + + if (block == -1) { + memset(buf, 0xFF, SM_SECTOR_SIZE); + goto unlock; + } + + if (sm_read_sector(ftl, zone_num, block, boffset, buf, NULL)) { + error = -EIO; + goto unlock; + } + + if (in_cache) + sm_cache_put(ftl, buf, boffset); +unlock: + mutex_unlock(&ftl->mutex); + return error; +} + +/* outside interface: write a sector */ +static int sm_write(struct mtd_blktrans_dev *dev, + unsigned long sec_no, char *buf) +{ + struct sm_ftl *ftl = dev->priv; + struct ftl_zone *zone; + int error = 0, zone_num, block, boffset; + + BUG_ON(ftl->readonly); + sm_break_offset(ftl, sec_no << 9, &zone_num, &block, &boffset); + + /* No need in flush thread running now */ + del_timer(&ftl->timer); + mutex_lock(&ftl->mutex); + + zone = sm_get_zone(ftl, zone_num); + if (IS_ERR(zone)) { + error = PTR_ERR(zone); + goto unlock; + } + + /* If entry is not in cache, flush it */ + if (ftl->cache_block != block || ftl->cache_zone != zone_num) { + + error = sm_cache_flush(ftl); + if (error) + goto unlock; + + ftl->cache_block = block; + ftl->cache_zone = zone_num; + } + + sm_cache_put(ftl, buf, boffset); +unlock: + mod_timer(&ftl->timer, jiffies + msecs_to_jiffies(cache_timeout)); + mutex_unlock(&ftl->mutex); + return error; +} + +/* outside interface: flush everything */ +static int sm_flush(struct mtd_blktrans_dev *dev) +{ + struct sm_ftl *ftl = dev->priv; + int retval; + + mutex_lock(&ftl->mutex); + retval = sm_cache_flush(ftl); + mutex_unlock(&ftl->mutex); + return retval; +} + +/* outside interface: device is released */ +static void sm_release(struct mtd_blktrans_dev *dev) +{ + struct sm_ftl *ftl = dev->priv; + + mutex_lock(&ftl->mutex); + del_timer_sync(&ftl->timer); + cancel_work_sync(&ftl->flush_work); + sm_cache_flush(ftl); + mutex_unlock(&ftl->mutex); +} + +/* outside interface: get geometry */ +static int sm_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo) +{ + struct sm_ftl *ftl = dev->priv; + geo->heads = ftl->heads; + geo->sectors = ftl->sectors; + geo->cylinders = ftl->cylinders; + return 0; +} + +/* external interface: main initialization function */ +static void sm_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd) +{ + struct mtd_blktrans_dev *trans; + struct sm_ftl *ftl; + + /* Allocate & initialize our private structure */ + ftl = kzalloc(sizeof(struct sm_ftl), GFP_KERNEL); + if (!ftl) + goto error1; + + + mutex_init(&ftl->mutex); + timer_setup(&ftl->timer, sm_cache_flush_timer, 0); + INIT_WORK(&ftl->flush_work, sm_cache_flush_work); + + /* Read media information */ + if (sm_get_media_info(ftl, mtd)) { + dbg("found unsupported mtd device, aborting"); + goto error2; + } + + + /* Allocate temporary CIS buffer for read retry support */ + ftl->cis_buffer = kzalloc(SM_SECTOR_SIZE, GFP_KERNEL); + if (!ftl->cis_buffer) + goto error2; + + /* Allocate zone array, it will be initialized on demand */ + ftl->zones = kcalloc(ftl->zone_count, sizeof(struct ftl_zone), + GFP_KERNEL); + if (!ftl->zones) + goto error3; + + /* Allocate the cache*/ + ftl->cache_data = kzalloc(ftl->block_size, GFP_KERNEL); + + if (!ftl->cache_data) + goto error4; + + sm_cache_init(ftl); + + + /* Allocate upper layer structure and initialize it */ + trans = kzalloc(sizeof(struct mtd_blktrans_dev), GFP_KERNEL); + if (!trans) + goto error5; + + ftl->trans = trans; + trans->priv = ftl; + + trans->tr = tr; + trans->mtd = mtd; + trans->devnum = -1; + trans->size = (ftl->block_size * ftl->max_lba * ftl->zone_count) >> 9; + trans->readonly = ftl->readonly; + + if (sm_find_cis(ftl)) { + dbg("CIS not found on mtd device, aborting"); + goto error6; + } + + ftl->disk_attributes = sm_create_sysfs_attributes(ftl); + if (!ftl->disk_attributes) + goto error6; + trans->disk_attributes = ftl->disk_attributes; + + sm_printk("Found %d MiB xD/SmartMedia FTL on mtd%d", + (int)(mtd->size / (1024 * 1024)), mtd->index); + + dbg("FTL layout:"); + dbg("%d zone(s), each consists of %d blocks (+%d spares)", + ftl->zone_count, ftl->max_lba, + ftl->zone_size - ftl->max_lba); + dbg("each block consists of %d bytes", + ftl->block_size); + + + /* Register device*/ + if (add_mtd_blktrans_dev(trans)) { + dbg("error in mtdblktrans layer"); + goto error6; + } + return; +error6: + kfree(trans); +error5: + kfree(ftl->cache_data); +error4: + kfree(ftl->zones); +error3: + kfree(ftl->cis_buffer); +error2: + kfree(ftl); +error1: + return; +} + +/* main interface: device {surprise,} removal */ +static void sm_remove_dev(struct mtd_blktrans_dev *dev) +{ + struct sm_ftl *ftl = dev->priv; + int i; + + del_mtd_blktrans_dev(dev); + ftl->trans = NULL; + + for (i = 0 ; i < ftl->zone_count; i++) { + + if (!ftl->zones[i].initialized) + continue; + + kfree(ftl->zones[i].lba_to_phys_table); + kfifo_free(&ftl->zones[i].free_sectors); + } + + sm_delete_sysfs_attributes(ftl); + kfree(ftl->cis_buffer); + kfree(ftl->zones); + kfree(ftl->cache_data); + kfree(ftl); +} + +static struct mtd_blktrans_ops sm_ftl_ops = { + .name = "smblk", + .major = 0, + .part_bits = SM_FTL_PARTN_BITS, + .blksize = SM_SECTOR_SIZE, + .getgeo = sm_getgeo, + + .add_mtd = sm_add_mtd, + .remove_dev = sm_remove_dev, + + .readsect = sm_read, + .writesect = sm_write, + + .flush = sm_flush, + .release = sm_release, + + .owner = THIS_MODULE, +}; + +static __init int sm_module_init(void) +{ + int error = 0; + + cache_flush_workqueue = create_freezable_workqueue("smflush"); + if (!cache_flush_workqueue) + return -ENOMEM; + + error = register_mtd_blktrans(&sm_ftl_ops); + if (error) + destroy_workqueue(cache_flush_workqueue); + return error; + +} + +static void __exit sm_module_exit(void) +{ + destroy_workqueue(cache_flush_workqueue); + deregister_mtd_blktrans(&sm_ftl_ops); +} + +module_init(sm_module_init); +module_exit(sm_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Maxim Levitsky <maximlevitsky@gmail.com>"); +MODULE_DESCRIPTION("Smartmedia/xD mtd translation layer"); |