linux/drivers/mtd/rfd_ftl.c
Paul Gortmaker a0e5cc581b mtd: Add module.h to drivers users that were implicitly using it.
We are cleaning up the implicit presence of module.h that these
drivers are taking advantage of.  Fix them in advance of the
cleanup operation.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:31:12 -04:00

854 lines
18 KiB
C

/*
* rfd_ftl.c -- resident flash disk (flash translation layer)
*
* Copyright © 2005 Sean Young <sean@mess.org>
*
* This type of flash translation layer (FTL) is used by the Embedded BIOS
* by General Software. It is known as the Resident Flash Disk (RFD), see:
*
* http://www.gensw.com/pages/prod/bios/rfd.htm
*
* based on ftl.c
*/
#include <linux/hdreg.h>
#include <linux/init.h>
#include <linux/mtd/blktrans.h>
#include <linux/mtd/mtd.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/module.h>
#include <asm/types.h>
static int block_size = 0;
module_param(block_size, int, 0);
MODULE_PARM_DESC(block_size, "Block size to use by RFD, defaults to erase unit size");
#define PREFIX "rfd_ftl: "
/* This major has been assigned by device@lanana.org */
#ifndef RFD_FTL_MAJOR
#define RFD_FTL_MAJOR 256
#endif
/* Maximum number of partitions in an FTL region */
#define PART_BITS 4
/* An erase unit should start with this value */
#define RFD_MAGIC 0x9193
/* the second value is 0xffff or 0xffc8; function unknown */
/* the third value is always 0xffff, ignored */
/* next is an array of mapping for each corresponding sector */
#define HEADER_MAP_OFFSET 3
#define SECTOR_DELETED 0x0000
#define SECTOR_ZERO 0xfffe
#define SECTOR_FREE 0xffff
#define SECTOR_SIZE 512
#define SECTORS_PER_TRACK 63
struct block {
enum {
BLOCK_OK,
BLOCK_ERASING,
BLOCK_ERASED,
BLOCK_UNUSED,
BLOCK_FAILED
} state;
int free_sectors;
int used_sectors;
int erases;
u_long offset;
};
struct partition {
struct mtd_blktrans_dev mbd;
u_int block_size; /* size of erase unit */
u_int total_blocks; /* number of erase units */
u_int header_sectors_per_block; /* header sectors in erase unit */
u_int data_sectors_per_block; /* data sectors in erase unit */
u_int sector_count; /* sectors in translated disk */
u_int header_size; /* bytes in header sector */
int reserved_block; /* block next up for reclaim */
int current_block; /* block to write to */
u16 *header_cache; /* cached header */
int is_reclaiming;
int cylinders;
int errors;
u_long *sector_map;
struct block *blocks;
};
static int rfd_ftl_writesect(struct mtd_blktrans_dev *dev, u_long sector, char *buf);
static int build_block_map(struct partition *part, int block_no)
{
struct block *block = &part->blocks[block_no];
int i;
block->offset = part->block_size * block_no;
if (le16_to_cpu(part->header_cache[0]) != RFD_MAGIC) {
block->state = BLOCK_UNUSED;
return -ENOENT;
}
block->state = BLOCK_OK;
for (i=0; i<part->data_sectors_per_block; i++) {
u16 entry;
entry = le16_to_cpu(part->header_cache[HEADER_MAP_OFFSET + i]);
if (entry == SECTOR_DELETED)
continue;
if (entry == SECTOR_FREE) {
block->free_sectors++;
continue;
}
if (entry == SECTOR_ZERO)
entry = 0;
if (entry >= part->sector_count) {
printk(KERN_WARNING PREFIX
"'%s': unit #%d: entry %d corrupt, "
"sector %d out of range\n",
part->mbd.mtd->name, block_no, i, entry);
continue;
}
if (part->sector_map[entry] != -1) {
printk(KERN_WARNING PREFIX
"'%s': more than one entry for sector %d\n",
part->mbd.mtd->name, entry);
part->errors = 1;
continue;
}
part->sector_map[entry] = block->offset +
(i + part->header_sectors_per_block) * SECTOR_SIZE;
block->used_sectors++;
}
if (block->free_sectors == part->data_sectors_per_block)
part->reserved_block = block_no;
return 0;
}
static int scan_header(struct partition *part)
{
int sectors_per_block;
int i, rc = -ENOMEM;
int blocks_found;
size_t retlen;
sectors_per_block = part->block_size / SECTOR_SIZE;
part->total_blocks = (u32)part->mbd.mtd->size / part->block_size;
if (part->total_blocks < 2)
return -ENOENT;
/* each erase block has three bytes header, followed by the map */
part->header_sectors_per_block =
((HEADER_MAP_OFFSET + sectors_per_block) *
sizeof(u16) + SECTOR_SIZE - 1) / SECTOR_SIZE;
part->data_sectors_per_block = sectors_per_block -
part->header_sectors_per_block;
part->header_size = (HEADER_MAP_OFFSET +
part->data_sectors_per_block) * sizeof(u16);
part->cylinders = (part->data_sectors_per_block *
(part->total_blocks - 1) - 1) / SECTORS_PER_TRACK;
part->sector_count = part->cylinders * SECTORS_PER_TRACK;
part->current_block = -1;
part->reserved_block = -1;
part->is_reclaiming = 0;
part->header_cache = kmalloc(part->header_size, GFP_KERNEL);
if (!part->header_cache)
goto err;
part->blocks = kcalloc(part->total_blocks, sizeof(struct block),
GFP_KERNEL);
if (!part->blocks)
goto err;
part->sector_map = vmalloc(part->sector_count * sizeof(u_long));
if (!part->sector_map) {
printk(KERN_ERR PREFIX "'%s': unable to allocate memory for "
"sector map", part->mbd.mtd->name);
goto err;
}
for (i=0; i<part->sector_count; i++)
part->sector_map[i] = -1;
for (i=0, blocks_found=0; i<part->total_blocks; i++) {
rc = part->mbd.mtd->read(part->mbd.mtd,
i * part->block_size, part->header_size,
&retlen, (u_char*)part->header_cache);
if (!rc && retlen != part->header_size)
rc = -EIO;
if (rc)
goto err;
if (!build_block_map(part, i))
blocks_found++;
}
if (blocks_found == 0) {
printk(KERN_NOTICE PREFIX "no RFD magic found in '%s'\n",
part->mbd.mtd->name);
rc = -ENOENT;
goto err;
}
if (part->reserved_block == -1) {
printk(KERN_WARNING PREFIX "'%s': no empty erase unit found\n",
part->mbd.mtd->name);
part->errors = 1;
}
return 0;
err:
vfree(part->sector_map);
kfree(part->header_cache);
kfree(part->blocks);
return rc;
}
static int rfd_ftl_readsect(struct mtd_blktrans_dev *dev, u_long sector, char *buf)
{
struct partition *part = (struct partition*)dev;
u_long addr;
size_t retlen;
int rc;
if (sector >= part->sector_count)
return -EIO;
addr = part->sector_map[sector];
if (addr != -1) {
rc = part->mbd.mtd->read(part->mbd.mtd, addr, SECTOR_SIZE,
&retlen, (u_char*)buf);
if (!rc && retlen != SECTOR_SIZE)
rc = -EIO;
if (rc) {
printk(KERN_WARNING PREFIX "error reading '%s' at "
"0x%lx\n", part->mbd.mtd->name, addr);
return rc;
}
} else
memset(buf, 0, SECTOR_SIZE);
return 0;
}
static void erase_callback(struct erase_info *erase)
{
struct partition *part;
u16 magic;
int i, rc;
size_t retlen;
part = (struct partition*)erase->priv;
i = (u32)erase->addr / part->block_size;
if (i >= part->total_blocks || part->blocks[i].offset != erase->addr ||
erase->addr > UINT_MAX) {
printk(KERN_ERR PREFIX "erase callback for unknown offset %llx "
"on '%s'\n", (unsigned long long)erase->addr, part->mbd.mtd->name);
return;
}
if (erase->state != MTD_ERASE_DONE) {
printk(KERN_WARNING PREFIX "erase failed at 0x%llx on '%s', "
"state %d\n", (unsigned long long)erase->addr,
part->mbd.mtd->name, erase->state);
part->blocks[i].state = BLOCK_FAILED;
part->blocks[i].free_sectors = 0;
part->blocks[i].used_sectors = 0;
kfree(erase);
return;
}
magic = cpu_to_le16(RFD_MAGIC);
part->blocks[i].state = BLOCK_ERASED;
part->blocks[i].free_sectors = part->data_sectors_per_block;
part->blocks[i].used_sectors = 0;
part->blocks[i].erases++;
rc = part->mbd.mtd->write(part->mbd.mtd,
part->blocks[i].offset, sizeof(magic), &retlen,
(u_char*)&magic);
if (!rc && retlen != sizeof(magic))
rc = -EIO;
if (rc) {
printk(KERN_ERR PREFIX "'%s': unable to write RFD "
"header at 0x%lx\n",
part->mbd.mtd->name,
part->blocks[i].offset);
part->blocks[i].state = BLOCK_FAILED;
}
else
part->blocks[i].state = BLOCK_OK;
kfree(erase);
}
static int erase_block(struct partition *part, int block)
{
struct erase_info *erase;
int rc = -ENOMEM;
erase = kmalloc(sizeof(struct erase_info), GFP_KERNEL);
if (!erase)
goto err;
erase->mtd = part->mbd.mtd;
erase->callback = erase_callback;
erase->addr = part->blocks[block].offset;
erase->len = part->block_size;
erase->priv = (u_long)part;
part->blocks[block].state = BLOCK_ERASING;
part->blocks[block].free_sectors = 0;
rc = part->mbd.mtd->erase(part->mbd.mtd, erase);
if (rc) {
printk(KERN_ERR PREFIX "erase of region %llx,%llx on '%s' "
"failed\n", (unsigned long long)erase->addr,
(unsigned long long)erase->len, part->mbd.mtd->name);
kfree(erase);
}
err:
return rc;
}
static int move_block_contents(struct partition *part, int block_no, u_long *old_sector)
{
void *sector_data;
u16 *map;
size_t retlen;
int i, rc = -ENOMEM;
part->is_reclaiming = 1;
sector_data = kmalloc(SECTOR_SIZE, GFP_KERNEL);
if (!sector_data)
goto err3;
map = kmalloc(part->header_size, GFP_KERNEL);
if (!map)
goto err2;
rc = part->mbd.mtd->read(part->mbd.mtd,
part->blocks[block_no].offset, part->header_size,
&retlen, (u_char*)map);
if (!rc && retlen != part->header_size)
rc = -EIO;
if (rc) {
printk(KERN_ERR PREFIX "error reading '%s' at "
"0x%lx\n", part->mbd.mtd->name,
part->blocks[block_no].offset);
goto err;
}
for (i=0; i<part->data_sectors_per_block; i++) {
u16 entry = le16_to_cpu(map[HEADER_MAP_OFFSET + i]);
u_long addr;
if (entry == SECTOR_FREE || entry == SECTOR_DELETED)
continue;
if (entry == SECTOR_ZERO)
entry = 0;
/* already warned about and ignored in build_block_map() */
if (entry >= part->sector_count)
continue;
addr = part->blocks[block_no].offset +
(i + part->header_sectors_per_block) * SECTOR_SIZE;
if (*old_sector == addr) {
*old_sector = -1;
if (!part->blocks[block_no].used_sectors--) {
rc = erase_block(part, block_no);
break;
}
continue;
}
rc = part->mbd.mtd->read(part->mbd.mtd, addr,
SECTOR_SIZE, &retlen, sector_data);
if (!rc && retlen != SECTOR_SIZE)
rc = -EIO;
if (rc) {
printk(KERN_ERR PREFIX "'%s': Unable to "
"read sector for relocation\n",
part->mbd.mtd->name);
goto err;
}
rc = rfd_ftl_writesect((struct mtd_blktrans_dev*)part,
entry, sector_data);
if (rc)
goto err;
}
err:
kfree(map);
err2:
kfree(sector_data);
err3:
part->is_reclaiming = 0;
return rc;
}
static int reclaim_block(struct partition *part, u_long *old_sector)
{
int block, best_block, score, old_sector_block;
int rc;
/* we have a race if sync doesn't exist */
if (part->mbd.mtd->sync)
part->mbd.mtd->sync(part->mbd.mtd);
score = 0x7fffffff; /* MAX_INT */
best_block = -1;
if (*old_sector != -1)
old_sector_block = *old_sector / part->block_size;
else
old_sector_block = -1;
for (block=0; block<part->total_blocks; block++) {
int this_score;
if (block == part->reserved_block)
continue;
/*
* Postpone reclaiming if there is a free sector as
* more removed sectors is more efficient (have to move
* less).
*/
if (part->blocks[block].free_sectors)
return 0;
this_score = part->blocks[block].used_sectors;
if (block == old_sector_block)
this_score--;
else {
/* no point in moving a full block */
if (part->blocks[block].used_sectors ==
part->data_sectors_per_block)
continue;
}
this_score += part->blocks[block].erases;
if (this_score < score) {
best_block = block;
score = this_score;
}
}
if (best_block == -1)
return -ENOSPC;
part->current_block = -1;
part->reserved_block = best_block;
pr_debug("reclaim_block: reclaiming block #%d with %d used "
"%d free sectors\n", best_block,
part->blocks[best_block].used_sectors,
part->blocks[best_block].free_sectors);
if (part->blocks[best_block].used_sectors)
rc = move_block_contents(part, best_block, old_sector);
else
rc = erase_block(part, best_block);
return rc;
}
/*
* IMPROVE: It would be best to choose the block with the most deleted sectors,
* because if we fill that one up first it'll have the most chance of having
* the least live sectors at reclaim.
*/
static int find_free_block(struct partition *part)
{
int block, stop;
block = part->current_block == -1 ?
jiffies % part->total_blocks : part->current_block;
stop = block;
do {
if (part->blocks[block].free_sectors &&
block != part->reserved_block)
return block;
if (part->blocks[block].state == BLOCK_UNUSED)
erase_block(part, block);
if (++block >= part->total_blocks)
block = 0;
} while (block != stop);
return -1;
}
static int find_writable_block(struct partition *part, u_long *old_sector)
{
int rc, block;
size_t retlen;
block = find_free_block(part);
if (block == -1) {
if (!part->is_reclaiming) {
rc = reclaim_block(part, old_sector);
if (rc)
goto err;
block = find_free_block(part);
}
if (block == -1) {
rc = -ENOSPC;
goto err;
}
}
rc = part->mbd.mtd->read(part->mbd.mtd, part->blocks[block].offset,
part->header_size, &retlen, (u_char*)part->header_cache);
if (!rc && retlen != part->header_size)
rc = -EIO;
if (rc) {
printk(KERN_ERR PREFIX "'%s': unable to read header at "
"0x%lx\n", part->mbd.mtd->name,
part->blocks[block].offset);
goto err;
}
part->current_block = block;
err:
return rc;
}
static int mark_sector_deleted(struct partition *part, u_long old_addr)
{
int block, offset, rc;
u_long addr;
size_t retlen;
u16 del = cpu_to_le16(SECTOR_DELETED);
block = old_addr / part->block_size;
offset = (old_addr % part->block_size) / SECTOR_SIZE -
part->header_sectors_per_block;
addr = part->blocks[block].offset +
(HEADER_MAP_OFFSET + offset) * sizeof(u16);
rc = part->mbd.mtd->write(part->mbd.mtd, addr,
sizeof(del), &retlen, (u_char*)&del);
if (!rc && retlen != sizeof(del))
rc = -EIO;
if (rc) {
printk(KERN_ERR PREFIX "error writing '%s' at "
"0x%lx\n", part->mbd.mtd->name, addr);
if (rc)
goto err;
}
if (block == part->current_block)
part->header_cache[offset + HEADER_MAP_OFFSET] = del;
part->blocks[block].used_sectors--;
if (!part->blocks[block].used_sectors &&
!part->blocks[block].free_sectors)
rc = erase_block(part, block);
err:
return rc;
}
static int find_free_sector(const struct partition *part, const struct block *block)
{
int i, stop;
i = stop = part->data_sectors_per_block - block->free_sectors;
do {
if (le16_to_cpu(part->header_cache[HEADER_MAP_OFFSET + i])
== SECTOR_FREE)
return i;
if (++i == part->data_sectors_per_block)
i = 0;
}
while(i != stop);
return -1;
}
static int do_writesect(struct mtd_blktrans_dev *dev, u_long sector, char *buf, ulong *old_addr)
{
struct partition *part = (struct partition*)dev;
struct block *block;
u_long addr;
int i;
int rc;
size_t retlen;
u16 entry;
if (part->current_block == -1 ||
!part->blocks[part->current_block].free_sectors) {
rc = find_writable_block(part, old_addr);
if (rc)
goto err;
}
block = &part->blocks[part->current_block];
i = find_free_sector(part, block);
if (i < 0) {
rc = -ENOSPC;
goto err;
}
addr = (i + part->header_sectors_per_block) * SECTOR_SIZE +
block->offset;
rc = part->mbd.mtd->write(part->mbd.mtd,
addr, SECTOR_SIZE, &retlen, (u_char*)buf);
if (!rc && retlen != SECTOR_SIZE)
rc = -EIO;
if (rc) {
printk(KERN_ERR PREFIX "error writing '%s' at 0x%lx\n",
part->mbd.mtd->name, addr);
if (rc)
goto err;
}
part->sector_map[sector] = addr;
entry = cpu_to_le16(sector == 0 ? SECTOR_ZERO : sector);
part->header_cache[i + HEADER_MAP_OFFSET] = entry;
addr = block->offset + (HEADER_MAP_OFFSET + i) * sizeof(u16);
rc = part->mbd.mtd->write(part->mbd.mtd, addr,
sizeof(entry), &retlen, (u_char*)&entry);
if (!rc && retlen != sizeof(entry))
rc = -EIO;
if (rc) {
printk(KERN_ERR PREFIX "error writing '%s' at 0x%lx\n",
part->mbd.mtd->name, addr);
if (rc)
goto err;
}
block->used_sectors++;
block->free_sectors--;
err:
return rc;
}
static int rfd_ftl_writesect(struct mtd_blktrans_dev *dev, u_long sector, char *buf)
{
struct partition *part = (struct partition*)dev;
u_long old_addr;
int i;
int rc = 0;
pr_debug("rfd_ftl_writesect(sector=0x%lx)\n", sector);
if (part->reserved_block == -1) {
rc = -EACCES;
goto err;
}
if (sector >= part->sector_count) {
rc = -EIO;
goto err;
}
old_addr = part->sector_map[sector];
for (i=0; i<SECTOR_SIZE; i++) {
if (!buf[i])
continue;
rc = do_writesect(dev, sector, buf, &old_addr);
if (rc)
goto err;
break;
}
if (i == SECTOR_SIZE)
part->sector_map[sector] = -1;
if (old_addr != -1)
rc = mark_sector_deleted(part, old_addr);
err:
return rc;
}
static int rfd_ftl_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo)
{
struct partition *part = (struct partition*)dev;
geo->heads = 1;
geo->sectors = SECTORS_PER_TRACK;
geo->cylinders = part->cylinders;
return 0;
}
static void rfd_ftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
{
struct partition *part;
if (mtd->type != MTD_NORFLASH || mtd->size > UINT_MAX)
return;
part = kzalloc(sizeof(struct partition), GFP_KERNEL);
if (!part)
return;
part->mbd.mtd = mtd;
if (block_size)
part->block_size = block_size;
else {
if (!mtd->erasesize) {
printk(KERN_WARNING PREFIX "please provide block_size");
goto out;
} else
part->block_size = mtd->erasesize;
}
if (scan_header(part) == 0) {
part->mbd.size = part->sector_count;
part->mbd.tr = tr;
part->mbd.devnum = -1;
if (!(mtd->flags & MTD_WRITEABLE))
part->mbd.readonly = 1;
else if (part->errors) {
printk(KERN_WARNING PREFIX "'%s': errors found, "
"setting read-only\n", mtd->name);
part->mbd.readonly = 1;
}
printk(KERN_INFO PREFIX "name: '%s' type: %d flags %x\n",
mtd->name, mtd->type, mtd->flags);
if (!add_mtd_blktrans_dev((void*)part))
return;
}
out:
kfree(part);
}
static void rfd_ftl_remove_dev(struct mtd_blktrans_dev *dev)
{
struct partition *part = (struct partition*)dev;
int i;
for (i=0; i<part->total_blocks; i++) {
pr_debug("rfd_ftl_remove_dev:'%s': erase unit #%02d: %d erases\n",
part->mbd.mtd->name, i, part->blocks[i].erases);
}
del_mtd_blktrans_dev(dev);
vfree(part->sector_map);
kfree(part->header_cache);
kfree(part->blocks);
}
static struct mtd_blktrans_ops rfd_ftl_tr = {
.name = "rfd",
.major = RFD_FTL_MAJOR,
.part_bits = PART_BITS,
.blksize = SECTOR_SIZE,
.readsect = rfd_ftl_readsect,
.writesect = rfd_ftl_writesect,
.getgeo = rfd_ftl_getgeo,
.add_mtd = rfd_ftl_add_mtd,
.remove_dev = rfd_ftl_remove_dev,
.owner = THIS_MODULE,
};
static int __init init_rfd_ftl(void)
{
return register_mtd_blktrans(&rfd_ftl_tr);
}
static void __exit cleanup_rfd_ftl(void)
{
deregister_mtd_blktrans(&rfd_ftl_tr);
}
module_init(init_rfd_ftl);
module_exit(cleanup_rfd_ftl);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Sean Young <sean@mess.org>");
MODULE_DESCRIPTION("Support code for RFD Flash Translation Layer, "
"used by General Software's Embedded BIOS");