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sm_ftl.c
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sm_ftl.c
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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright © 2009 - Maxim Levitsky
* SmartMedia/xD translation layer
*/
#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-sw-hamming.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)
{
bool sm_order = IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING_SMC);
uint8_t ecc[3];
ecc_sw_hamming_calculate(buffer, SM_SMALL_PAGE, ecc, sm_order);
if (ecc_sw_hamming_correct(buffer, ecc, oob->ecc1, SM_SMALL_PAGE,
sm_order) < 0)
return -EIO;
buffer += SM_SMALL_PAGE;
ecc_sw_hamming_calculate(buffer, SM_SMALL_PAGE, ecc, sm_order);
if (ecc_sw_hamming_correct(buffer, ecc, oob->ecc2, SM_SMALL_PAGE,
sm_order) < 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) {
if (buffer)
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)
{
bool sm_order = IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING_SMC);
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) {
ecc_sw_hamming_calculate(buf + boffset,
SM_SMALL_PAGE, oob.ecc1,
sm_order);
ecc_sw_hamming_calculate(buf + boffset + SM_SMALL_PAGE,
SM_SMALL_PAGE, oob.ecc2,
sm_order);
}
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)) {
kfifo_free(&zone->free_sectors);
kfree(zone->lba_to_phys_table);
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 successful, 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 */