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Subject[PATCH 9/9] mtd: Add new SmartMedia/xD FTL
From
Date
>From 743f723b6e7134cf9d99a158f3ac920c180d406a Mon Sep 17 00:00:00 2001
From: Maxim Levitsky <maximlevitsky@gmail.com>
Date: Fri, 8 Jan 2010 16:44:07 +0200
Subject: [PATCH 9/9] mtd: Add new SmartMedia/xD FTL

This implements new readwrite SmartMedia/xd FTL.

It depends on nand driver to define proper oob layout that excludes
all ecc areas and nothing more.

Support for very old 256 byte/page devices is not yet enabled/complete.
For these devices, all ecc handling will be done inside this FTL
due to wierd oob layout.

Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
---
drivers/mtd/Kconfig | 12 +
drivers/mtd/Makefile | 1 +
drivers/mtd/sm_ftl.c | 1043 ++++++++++++++++++++++++++++++++++++++++++++++++++
drivers/mtd/sm_ftl.h | 75 ++++
4 files changed, 1131 insertions(+), 0 deletions(-)
create mode 100644 drivers/mtd/sm_ftl.c
create mode 100644 drivers/mtd/sm_ftl.h
diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
index ebeabd6..e13bf41 100644
--- a/drivers/mtd/Kconfig
+++ b/drivers/mtd/Kconfig
@@ -313,6 +313,18 @@ config SSFDC
This enables read only access to SmartMedia formatted NAND
flash. You can mount it with FAT file system.

+
+config SM_FTL
+ tristate "SmartMedia/xD new translation layer"
+ depends on EXPERIMENTAL
+ select MTD_SM_COMMON
+ help
+ This enables new and very EXPERMENTAL support for SmartMedia/xD
+ FTL (Flash tanslation layer)
+ Write support isn't yet well tested, therefore this code IS likely to
+ eat your card, so please don't use it together with valuable data.
+ Use readonly driver (CONFIG_SSFDC) instead.
+
config MTD_OOPS
tristate "Log panic/oops to an MTD buffer"
depends on MTD
diff --git a/drivers/mtd/Makefile b/drivers/mtd/Makefile
index 02c5b17..02f6375 100644
--- a/drivers/mtd/Makefile
+++ b/drivers/mtd/Makefile
@@ -25,6 +25,7 @@ obj-$(CONFIG_NFTL) += nftl.o
obj-$(CONFIG_INFTL) += inftl.o
obj-$(CONFIG_RFD_FTL) += rfd_ftl.o
obj-$(CONFIG_SSFDC) += ssfdc.o
+obj-$(CONFIG_SM_FTL) += sm_ftl.o
obj-$(CONFIG_MTD_OOPS) += mtdoops.o

nftl-objs := nftlcore.o nftlmount.o
diff --git a/drivers/mtd/sm_ftl.c b/drivers/mtd/sm_ftl.c
new file mode 100644
index 0000000..b72c30b
--- /dev/null
+++ b/drivers/mtd/sm_ftl.c
@@ -0,0 +1,1043 @@
+/*
+ * Copyright (C) 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/bitops.h>
+#include "sm_common.h"
+#include "sm_ftl.h"
+
+static u8 tmp_buffer[SM_SECTOR_SIZE];
+static int cache_size = 5;
+
+module_param(cache_size, int, S_IRUGO);
+MODULE_PARM_DESC(cache_size,
+ "Number of blocks to hold in the cache (5 default)");
+
+
+static void sm_erase_callback(struct erase_info *self);
+static void sm_erase_block(struct sm_ftl *ftl, int zone_num, s16 block,
+ int put_free);
+static void sm_mark_block_bad(struct sm_ftl *ftl, int zone_num, int block);
+static int sm_cache_flush_thread(void *data);
+
+
+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 },
+};
+
+/* Find out media parameters.
+ * This ideally has to be based on nand id, but for now device size is enough */
+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 Mb flas/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 Mb 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 Mb rom SmartMedia */
+ } else {
+ ftl->zone_size = 256;
+ ftl->max_lba = 250;
+ ftl->block_size = 16 * SM_SECTOR_SIZE;
+ }
+ break;
+ case 4:
+ /* 4 Mb flash/rom SmartMedia device */
+ ftl->zone_size = 512;
+ ftl->max_lba = 500;
+ ftl->block_size = 16 * SM_SECTOR_SIZE;
+ break;
+ case 8:
+ /* 8 Mb flash/rom SmartMedia device */
+ ftl->zone_size = 1024;
+ ftl->max_lba = 1000;
+ ftl->block_size = 16 * SM_SECTOR_SIZE;
+ }
+
+ /* Minimum xD size is 16M, and thus all xD cards have standard zone
+ sizes. SmartMedia cards exist up to 128 Mb 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 and erase sizes */
+ if (mtd->erasesize > ftl->block_size)
+ return -ENODEV;
+
+ if (mtd->writesize > SM_SECTOR_SIZE)
+ return -ENODEV;
+
+ if (mtd->oobavail < sizeof(struct sm_oob))
+ return -ENODEV;
+
+ /* For now, don't support small page nand */
+ if (ftl->smallpagenand)
+ return -ENODEV;
+
+ /* This shouldn't happen */
+ if (ftl->zone_count * ftl->zone_size * ftl->block_size != mtd->size)
+ 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;
+ }
+ }
+
+ ftl->cylinders = 985;
+ ftl->heads = 33;
+ ftl->sectors = 63;
+ return 0;
+}
+
+/* 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 offset,
+ int *zone, int *block, int *boffset)
+{
+ *boffset = offset % ftl->block_size;
+ offset /= ftl->block_size;
+ *block = offset % ftl->max_lba;
+ offset /= ftl->max_lba;
+
+ if (offset >= ftl->zone_count)
+ dbg("sm_break_offset: try to access a zone %lx",
+ (long unsigned int)offset);
+
+ *zone = offset >= ftl->zone_count ? -1 : offset;
+}
+
+/* Reads a sector + oob*/
+static int sm_read_sector(struct sm_ftl *ftl,
+ int zone, int block, int boffset,
+ u8 *buffer, struct sm_oob *oob)
+{
+ struct mtd_oob_ops ops;
+ struct sm_oob tmp_oob;
+ struct mtd_info *mtd = ftl->trans->mtd;
+ int ret;
+ loff_t offset;
+
+ ops.len = SM_SECTOR_SIZE;
+ ops.datbuf = buffer;
+
+ if (!oob)
+ oob = &tmp_oob;
+
+ ops.mode = MTD_OOB_AUTO;
+ ops.ooboffs = 0;
+ ops.ooblen = sizeof(struct sm_oob);
+ ops.oobbuf = (void *)oob;
+
+ /* FTL can contain -1 entries that are by default filled with bits */
+ if (block == -1) {
+
+ if (buffer)
+ memset(buffer, 0xFF, SM_SECTOR_SIZE);
+ memset(oob, 0xFF, sizeof(struct sm_oob));
+ return 0;
+ }
+
+ offset = sm_mkoffset(ftl, zone, block, boffset);
+ ret = mtd->read_oob(mtd, offset, &ops);
+
+ if (ret) {
+ return -EIO;
+ dbg("read of sector at 0x%lx failed with error %d",
+ (long unsigned int)offset, ret);
+ }
+
+ if (ops.oobretlen != sizeof(struct sm_oob)) {
+ dbg("read of sector at 0x%lx failed with wrong oob len %d",
+ (long unsigned int)offset, (int)ops.oobretlen);
+ return -EIO;
+ }
+
+ if (buffer && sm_sector_valid(oob)) {
+ dbg("read of sector at 0x%lxfailed because "
+ "it is marked as invalid",
+ (long unsigned int)offset);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+/* Write a block using data and lba */
+static int sm_write_block(struct sm_ftl *ftl, u8 *buf,
+ int zone_num, int block, int lba)
+{
+ struct mtd_oob_ops ops;
+ struct mtd_info *mtd = ftl->trans->mtd;
+ int boffset;
+ loff_t offset;
+ int retry;
+
+ struct sm_oob oob;
+ memset(&oob, 0xFF, sizeof(oob));
+ sm_write_lba(&oob, lba);
+
+ if (zone_num == 0 && (block == ftl->cis_block || block == 0)) {
+ dbg("attempted to write the CIS!");
+ return -EIO;
+ }
+
+
+ ops.len = SM_SECTOR_SIZE;
+
+ ops.mode = MTD_OOB_AUTO;
+ ops.ooboffs = 0;
+ ops.ooblen = sizeof(struct sm_oob);
+ ops.oobbuf = (void *)&oob;
+
+ /* Use write_oob here because some xD cards only accept writes that
+ contain both page and oob write. These cards most likely
+ do their own ftl */
+
+ offset = sm_mkoffset(ftl, zone_num, block, 0);
+
+restart:
+ for (boffset = 0; boffset < ftl->block_size;
+ boffset += SM_SECTOR_SIZE) {
+
+ ops.datbuf = buf + boffset;
+
+ if (!ftl->trans->mtd->write_oob(ftl->trans->mtd,
+ offset + boffset, &ops))
+ continue;
+
+ if (!retry) {
+ dbg("write of block %d in zone %d failed, erasing it",
+ block, zone_num);
+
+ /* If write fails. try to erase the block */
+ sm_erase_block(ftl, zone_num, block, 0);
+ retry = 1;
+ goto restart;
+ } else {
+ dbg("write of block %d in zone %d failed again"
+ ", marking as bad", block, zone_num);
+
+ sm_mark_block_bad(ftl, zone_num, block);
+ return -EIO;
+ }
+ }
+ return 0;
+}
+
+/*
+ * Erase a block within a zone
+ * If erase succedes, it updates free block fifo
+ */
+static void sm_erase_block(struct sm_ftl *ftl, int zone_num, s16 block,
+ int put_free)
+{
+ struct ftl_zone *zone = &ftl->zones[zone_num];
+ struct erase_info erase;
+ struct mtd_info *mtd = ftl->trans->mtd;
+
+ erase.mtd = ftl->trans->mtd;
+ erase.callback = sm_erase_callback;
+ erase.addr = sm_mkoffset(ftl, zone_num, block, 0);
+ erase.len = ftl->block_size;
+ erase.priv = (u_long)ftl;
+
+ if (zone_num == 0 && (block == ftl->cis_block || block == 0)) {
+ dbg("attempted to erase the CIS!");
+ return;
+ }
+
+ if (ftl->trans->mtd->erase(ftl->trans->mtd, &erase)) {
+ dbg("erase of block %d in zone %d failed in mtd->erase call",
+ block, zone_num);
+ goto error;
+ }
+
+ wait_for_completion(&ftl->erase_completion);
+
+ if (ftl->erase_error) {
+ dbg("erase of block %d in zone %d failed after wait",
+ block, zone_num);
+ goto error;
+ }
+
+ if (put_free)
+ kfifo_in(&zone->free_sectors, (const unsigned char *)&block, 2);
+ return;
+
+error:
+ sm_mark_block_bad(ftl, zone_num, block);
+ return;
+}
+
+static void sm_erase_callback(struct erase_info *self)
+{
+ struct sm_ftl *ftl = (struct sm_ftl *)self->priv;
+ ftl->erase_error = (self->state == MTD_ERASE_FAILED);
+ complete(&ftl->erase_completion);
+}
+
+
+/*
+ * Throughtly test that block is valid and belongs
+ * to specified LBA. Tries to erase it if not
+ */
+static int sm_check_block_lba(struct sm_ftl *ftl, int zone, int block, int lba)
+{
+ int boffset;
+ struct sm_oob oob;
+ int tmp;
+
+ for (boffset = 0; boffset < ftl->block_size;
+ boffset += SM_SECTOR_SIZE) {
+
+ if (sm_read_sector(ftl, zone, block, boffset, tmp_buffer,
+ &oob)) {
+ dbg("block check: fail in sector %d in zone %d",
+ block, zone);
+ goto erase;
+ }
+
+ if (sm_block_valid(&oob) || sm_sector_valid(&oob)) {
+ dbg("block check: block/sector status invalid"
+ " for sector %d in zone %d",
+ block, zone);
+ goto erase;
+ }
+
+ tmp = sm_read_lba(&oob);
+
+ if (tmp != lba) {
+ dbg("block check: block offset %d, we get "
+ "different LBA (%d), should get %d",
+ boffset, tmp, lba);
+ goto erase;
+ }
+ }
+ return 0;
+erase:
+ sm_erase_block(ftl, zone, block, 1);
+ return -EIO;
+}
+
+/* Mark whole block at offset 'offs' as bad.
+ */
+static void sm_mark_block_bad(struct sm_ftl *ftl, int zone_num, int block)
+{
+ struct mtd_oob_ops ops;
+ struct sm_oob oob;
+ int boffset;
+ int offset = sm_mkoffset(ftl, zone_num, block, 0);
+ struct mtd_info *mtd = ftl->trans->mtd;
+
+ dbg("marking block %d of zone %d as bad", block, zone_num);
+ memset(&oob, 0xFF, sizeof(oob));
+ oob.block_status = 0xF0;
+
+ ops.mode = MTD_OOB_AUTO;
+ ops.ooboffs = 0;
+ ops.ooblen = sizeof(struct sm_oob);
+ ops.oobbuf = (void *)&oob;
+ ops.datbuf = NULL;
+
+ /* We aren't checking the return value, because we don't care */
+ for (boffset = 0; boffset < ftl->block_size; boffset += SM_SECTOR_SIZE)
+ mtd->write_oob(mtd, offset + boffset, &ops);
+}
+
+/* Initialize FTL mapping for one zone */
+struct ftl_zone *sm_initialize_zone(struct sm_ftl *ftl, int zone_num)
+{
+ struct sm_oob oob;
+ struct ftl_zone *zone;
+ u16 block;
+ int lba;
+ int i = 0;
+
+ BUG_ON(zone_num >= ftl->zone_count);
+ zone = &ftl->zones[zone_num];
+ if (zone->initialized)
+ return zone;
+
+ dbg("initializing zone %d", zone_num);
+
+ zone->lba_to_phys_table = kmalloc(ftl->max_lba * 2, GFP_KERNEL);
+
+ if (!zone->lba_to_phys_table)
+ return ERR_PTR(-ENOMEM);
+
+ if (kfifo_alloc(&zone->free_sectors, ftl->zone_size * 2, GFP_KERNEL)) {
+ kfree(zone->lba_to_phys_table);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ memset(zone->lba_to_phys_table, -1, ftl->max_lba * 2);
+
+ for (block = 0 ; block < ftl->zone_size ; block++) {
+
+ /* Skip blocks till the CIS (including) */
+ if (zone_num == 0 && block <= ftl->cis_block) {
+
+ if (block != ftl->cis_block)
+ dbg("skipping block %d because"
+ " it is before the CIS (%d)",
+ block, ftl->cis_block);
+ continue;
+ }
+
+ /* Not much that we can do with blocks without
+ * even readable oob... - skip*/
+ /* Shouldn't happen though */
+ if (sm_read_sector(ftl, zone_num, block, 0, NULL, &oob)) {
+ dbg("skipping block %d because it's "
+ "oob was unreadable", block);
+ continue;
+ }
+
+ /* Blocks with 0xFFs in the oob area are assumed free -
+ add to free table*/
+ lba = sm_read_lba(&oob);
+ if (lba == -1) {
+ kfifo_in(&zone->free_sectors,
+ (unsigned char *)&block, 2);
+ continue;
+ }
+
+ /* Blocks that are marked as invalid aren't for sure usable */
+ /* If such block has correct LBA and no other block has it,
+ return errors on read */
+ if (sm_block_valid(&oob)) {
+ if (lba >= 0 && lba < ftl->max_lba)
+ zone->lba_to_phys_table[lba] = -2;
+ dbg("skipping block %d because it was marked bad",
+ block);
+ continue;
+ }
+
+ /* Try to erase blocks that have invalid LBA,
+ but marked as valid */
+ if (lba >= ftl->max_lba || lba == -2) {
+ dbg("erasing block %d because it has invalid LBA (%d)",
+ block, lba);
+
+ sm_erase_block(ftl, zone_num, block, 1);
+ continue;
+ }
+
+ /* If there is no collision,
+ just put the sector in the FTL table */
+ if (zone->lba_to_phys_table[lba] < 0) {
+ /*dbg("LBA %04d -> PH %04d", lba, block);*/
+ zone->lba_to_phys_table[lba] = block;
+ continue;
+ }
+
+ dbg("collision of LBA %d between blocks %d and %d in zone %d",
+ lba, zone->lba_to_phys_table[lba], block, zone_num);
+
+ /* Otherwise, carefully see if one of them is invalid*/
+ if (sm_check_block_lba(ftl, zone_num, block, lba))
+ continue;
+
+ if (sm_check_block_lba(ftl, zone_num,
+ zone->lba_to_phys_table[lba], lba))
+ continue;
+
+ /* Now both blocks are valid and share same LBA...
+ I guess only solution is to throw a dice.... */
+ dbg("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)) {
+ dbg("no free blocks in zone %d", zone_num);
+ return zone;
+ }
+
+ return zone;
+
+ /* Randomize first block we write to */
+ get_random_bytes(&i, 2);
+ i %= (kfifo_len(&zone->free_sectors) / 2);
+
+
+ while (i--) {
+ kfifo_out(&zone->free_sectors, (unsigned char *)&block, 2);
+ kfifo_in(&zone->free_sectors, (const unsigned char *)&block, 2);
+ }
+ return zone;
+}
+
+/* Write one cached block to hardware */
+int sm_cache_block_write(struct sm_ftl *ftl, struct cached_block *cache_entry)
+{
+ struct ftl_zone *zone;
+
+ int sector_num;
+ u16 write_sector;
+ int zone_num = cache_entry->zone;
+ int block_num;
+
+ BUG_ON(cache_entry->zone < 0);
+ zone = &ftl->zones[cache_entry->zone];
+ block_num = zone->lba_to_phys_table[cache_entry->lba];
+
+
+ /* Read all unread areas of the cache block*/
+ for_each_bit(sector_num, &cache_entry->data_invalid_bitmap,
+ ftl->block_size / SM_SECTOR_SIZE) {
+
+
+ if (sm_read_sector(ftl,
+ zone_num, block_num, sector_num * SM_SECTOR_SIZE,
+ cache_entry->data + sector_num * SM_SECTOR_SIZE, NULL))
+ return -EIO;
+ }
+restart:
+ /* No spare blocks */
+ /* We could still continue by erasing the current block,
+ but for such worn out media it doesn't worth the trouble,
+ and the dangers */
+
+ if (!kfifo_len(&zone->free_sectors)) {
+ dbg("no free sectors for write!");
+ return -EIO;
+ }
+
+ kfifo_out(&zone->free_sectors, (unsigned char *)&write_sector, 2);
+
+ if (sm_write_block(ftl, cache_entry->data, zone_num, write_sector,
+ cache_entry->lba))
+ goto restart;
+
+ /* Update the FTL table */
+ zone->lba_to_phys_table[cache_entry->lba] = write_sector;
+
+ /* Write succesfull, so erase and free the old block */
+ if (block_num > 0)
+ sm_erase_block(ftl, zone_num, block_num, 1);
+ return 0;
+}
+
+/* Initialize new/used cache entry */
+static int sm_cache_block_init(struct sm_ftl *ftl,
+ struct cached_block *cache_entry)
+{
+ if (!cache_entry->data)
+ cache_entry->data = kmalloc(ftl->block_size, GFP_KERNEL);
+
+ if (!cache_entry->data)
+ return -ENOMEM;
+
+ cache_entry->data_invalid_bitmap = 0xFFFFFFFF;
+ cache_entry->lba = -1;
+ cache_entry->zone = -1;
+ return 0;
+}
+
+/* Flushes write cache, have to be run with ->cache_lock held */
+static int __sm_cache_flush(struct sm_ftl *ftl)
+{
+ struct cached_block *cache_entry = NULL, *tmp_entry;
+ struct mtd_info *mtd = ftl->trans->mtd;
+ int error;
+
+ if (ftl->readonly)
+ return -EROFS;
+
+ if (list_empty(&ftl->cache))
+ return 0;
+
+ list_for_each_entry_safe(cache_entry, tmp_entry, &ftl->cache,
+ list_member) {
+ /* Write should never fail, unless media is worn out */
+ if (sm_cache_block_write(ftl, cache_entry)) {
+ dbg("sm_ftl: failed to write block %d at zone %d",
+ (int)cache_entry->lba, cache_entry->zone);
+ ftl->readonly = 1;
+ return -EIO;
+ }
+
+ list_del(&cache_entry->list_member);
+ list_add(&cache_entry->list_member, &ftl->free_cache);
+
+ error = sm_cache_block_init(ftl, cache_entry);
+ if (error)
+ return error;
+ }
+ return 0;
+}
+
+
+/* Flushes the write cache */
+static int sm_cache_flush(struct sm_ftl *ftl)
+{
+ int retval;
+ mutex_lock(&ftl->cache_mutex);
+ retval = __sm_cache_flush(ftl);
+ mutex_unlock(&ftl->cache_mutex);
+ return retval;
+}
+
+/* Frees the write cache */
+static void sm_free_cache(struct sm_ftl *ftl)
+{
+ struct cached_block *cache_entry;
+
+ mutex_lock(&ftl->cache_mutex);
+ while (!list_empty(&ftl->free_cache)) {
+ cache_entry = list_first_entry(&ftl->free_cache,
+ struct cached_block, list_member);
+
+ kfree(cache_entry->data);
+ list_del(&cache_entry->list_member);
+ kfree(cache_entry);
+ }
+ mutex_unlock(&ftl->cache_mutex);
+}
+
+
+/* outside interface: open the device */
+static int sm_open(struct mtd_blktrans_dev *dev)
+{
+ struct sm_ftl *ftl = dev->priv;
+ ftl->flush_thread = kthread_run(sm_cache_flush_thread,
+ ftl, "smflush%d", dev->mtd->index);
+
+ if (IS_ERR(ftl->flush_thread))
+ return PTR_ERR(ftl->flush_thread);
+ return 0;
+}
+
+/* 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;
+ struct cached_block *cache_entry = NULL;
+ int error = 0;
+ int cache_found = 0;
+
+ int zone_num, block, boffset;
+
+ sm_break_offset(ftl, sect_no << 9, &zone_num, &block, &boffset);
+
+ zone = sm_initialize_zone(ftl, zone_num);
+ if (IS_ERR(zone))
+ return PTR_ERR(zone);
+
+ mutex_lock(&ftl->cache_mutex);
+
+ /* Have to look at cache first */
+ list_for_each_entry(cache_entry, &ftl->cache, list_member)
+ if (cache_entry->zone == zone_num &&
+ cache_entry->lba == block &&
+
+ !test_bit(boffset / SM_SECTOR_SIZE,
+ &cache_entry->data_invalid_bitmap)) {
+
+ memcpy(buf, cache_entry->data + boffset,
+ SM_SECTOR_SIZE);
+ 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 (block == -2) {
+ dbg("read block %d of zone %d marked invalid in the ftl",
+ block, zone_num);
+ error = -EIO;
+ goto unlock;
+ }
+
+ /* Do the read. The below relies on proper ftl setup and underlying
+ driver to check at least the ecc
+ */
+ if (sm_read_sector(ftl, zone_num, block, boffset, buf, NULL)) {
+ error = -EIO;
+ goto unlock;
+ }
+
+ /* If we already have the cache entry, then add the data there, because
+ we will need it anyway..*/
+ if (cache_found) {
+ memcpy(cache_entry->data + boffset, buf, SM_SECTOR_SIZE);
+ clear_bit(boffset / SM_SECTOR_SIZE,
+ &cache_entry->data_invalid_bitmap);
+ }
+unlock:
+ mutex_unlock(&ftl->cache_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;
+ struct cached_block *cache_entry = NULL;
+ int error;
+ int zone_num, block, boffset;
+ int cache_found = 0;
+
+ if (ftl->readonly)
+ return -EROFS;
+
+ /* Try to write the cache if possible */
+ mutex_lock(&ftl->cache_mutex);
+
+ sm_break_offset(ftl, sec_no << 9, &zone_num, &block, &boffset);
+
+ zone = sm_initialize_zone(ftl, zone_num);
+ if (IS_ERR(zone))
+ return PTR_ERR(zone);
+
+
+ /* Try to find existing cache entry */
+ list_for_each_entry(cache_entry, &ftl->cache, list_member)
+ if (cache_entry->zone == zone_num &&
+ cache_entry->lba == block) {
+ cache_found = 1;
+ break;
+ }
+
+ /* Entry not in the cache, create new cache entry */
+ if (!cache_found) {
+
+ /* Flush the cache if full */
+ if (list_empty(&ftl->free_cache)) {
+
+ error = __sm_cache_flush(ftl);
+
+ if (error)
+ goto unlock;
+ }
+
+ BUG_ON(list_empty(&ftl->free_cache));
+
+ cache_entry = list_first_entry(&ftl->free_cache,
+ struct cached_block, list_member);
+
+ cache_entry->lba = block;
+ cache_entry->zone = zone_num;
+
+ list_del(&cache_entry->list_member);
+ list_add(&cache_entry->list_member, &ftl->cache);
+ }
+
+ /* And finally put data there */
+ memcpy(cache_entry->data + boffset, buf, SM_SECTOR_SIZE);
+ clear_bit(boffset / SM_SECTOR_SIZE, &cache_entry->data_invalid_bitmap);
+unlock:
+ mutex_unlock(&ftl->cache_mutex);
+ return error;
+}
+
+/* outside interface: flush everything */
+static int sm_flush(struct mtd_blktrans_dev *dev)
+{
+ struct sm_ftl *ftl = dev->priv;
+ return sm_cache_flush(ftl);
+}
+
+/* outside interface: last user has quit using the device,
+ also called on removal */
+static int sm_release(struct mtd_blktrans_dev *dev)
+{
+ struct sm_ftl *ftl = dev->priv;
+ sm_cache_flush(ftl);
+ kthread_stop(ftl->flush_thread);
+ return 0;
+}
+
+/* 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;
+}
+
+
+/* Periodic cache flush thread */
+static int sm_cache_flush_thread(void *data)
+{
+ struct sm_ftl *ftl = (struct sm_ftl *)data;
+
+ set_freezable();
+ while (!kthread_should_stop()) {
+
+ try_to_freeze();
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(msecs_to_jiffies(500));
+ sm_cache_flush(ftl);
+ }
+
+ return 0;
+}
+
+static const u8 cis_signature[] = {
+ 0x01, 0x03, 0xD9, 0x01, 0xFF, 0x18, 0x02, 0xDF, 0x01, 0x20
+};
+
+/* Locate the CIS */
+static int sm_find_cis(struct sm_ftl *ftl)
+{
+ int block, boffset;
+ struct sm_oob oob;
+ int block_found = 0;
+
+
+ /* Scan 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;
+
+ /* Block might be still partially damaged, so scan for first valid
+ sector */
+ for (boffset = 0 ; boffset < ftl->block_size;
+ boffset += SM_SECTOR_SIZE) {
+
+ if (sm_read_sector(ftl, 0, block, boffset, tmp_buffer, &oob))
+ continue;
+
+ if (!memcmp(tmp_buffer, cis_signature, sizeof(cis_signature)))
+ goto found;
+
+ if (!memcmp(tmp_buffer + SM_SECTOR_SIZE / 2, cis_signature,
+ sizeof(cis_signature)))
+ goto found;
+ return -EIO;
+ }
+found:
+ ftl->cis_block = block;
+ dbg("CIS block found at offset %d", block * ftl->block_size + boffset);
+ 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;
+ int i;
+ struct cached_block *cache_entry;
+
+
+ /* Allocate & initialize our private structure */
+ ftl = kzalloc(sizeof(struct sm_ftl), GFP_KERNEL);
+ if (!ftl)
+ goto error1;
+
+ INIT_LIST_HEAD(&ftl->cache);
+ INIT_LIST_HEAD(&ftl->free_cache);
+ mutex_init(&ftl->cache_mutex);
+ init_completion(&ftl->erase_completion);
+
+ /* Read media information */
+ if (sm_get_media_info(ftl, mtd))
+ goto error2;
+
+ /* Allocate zone array, it will be initialized on demand */
+ ftl->zones = kzalloc(sizeof(struct ftl_zone) * ftl->zone_count,
+ GFP_KERNEL);
+ if (!ftl->zones)
+ goto error2;
+
+ /* Allocate write cache */
+ INIT_LIST_HEAD(&ftl->cache);
+ INIT_LIST_HEAD(&ftl->free_cache);
+
+ for (i = 0 ; i < cache_size ; i++) {
+ cache_entry = kzalloc(sizeof(struct cached_block),
+ GFP_KERNEL);
+ if (!cache_entry)
+ break;
+
+ if (sm_cache_block_init(ftl, cache_entry)) {
+ kfree(cache_entry);
+ break;
+ }
+ list_add(&cache_entry->list_member, &ftl->free_cache);
+ }
+
+ if (list_empty(&ftl->free_cache))
+ goto error3;
+
+ /* Allocate upper layer structure and initialize it */
+ trans = kzalloc(sizeof(struct mtd_blktrans_dev), GFP_KERNEL);
+ if (!trans)
+ goto error4;
+
+ 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))
+ goto error4;
+
+ /* Register device*/
+ if (add_mtd_blktrans_dev(trans))
+ goto error5;
+
+ dbg("Found %d MiB SmartMedia/xD card on %s",
+ (int)(mtd->size / (1024 * 1024)), mtd->name);
+
+ dbg("FTL layout:");
+ dbg("%d zones, 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);
+
+ return;
+error5:
+ kfree(trans);
+error4:
+ sm_free_cache(ftl);
+error3:
+ kfree(ftl->zones);
+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;
+ dbg("removing the ftl device");
+ del_mtd_blktrans_dev(dev);
+ kfree(ftl->zones);
+ sm_free_cache(ftl);
+ kfree(ftl); /* WE free that here, but the ->release can still
+ be called after ..... fuck */
+}
+
+static struct mtd_blktrans_ops sm_ftl_ops = {
+ .name = "smblk",
+ .major = -1,
+ .part_bits = SM_FTL_PARTN_BITS,
+ .blksize = SM_SECTOR_SIZE,
+ .getgeo = sm_getgeo,
+ .readsect = sm_read,
+ .writesect = sm_write,
+ .add_mtd = sm_add_mtd,
+ .remove_dev = sm_remove_dev,
+ .open = sm_open,
+ .release = sm_release,
+ .flush = sm_flush,
+ .owner = THIS_MODULE,
+};
+
+static __init int sm_module_init(void)
+{
+ return register_mtd_blktrans(&sm_ftl_ops);
+}
+
+static void __exit sm_module_exit(void)
+{
+ 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");
diff --git a/drivers/mtd/sm_ftl.h b/drivers/mtd/sm_ftl.h
new file mode 100644
index 0000000..d86d00e
--- /dev/null
+++ b/drivers/mtd/sm_ftl.h
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2009 - Maxim Levitsky
+ * SmartMedia/xD translation layer
+ *
+ * Based loosly on ssfdc.c which is
+ * (c) 2005 Eptar srl
+ * Author: Claudio Lanconelli <lanconelli.claudio@eptar.com>
+ *
+ * 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/mtd/nand.h>
+#include <linux/mtd/blktrans.h>
+#include <linux/list.h>
+#include <linux/kfifo.h>
+#include <linux/sched.h>
+#include <linux/completion.h>
+#include <linux/spinlock.h>
+
+
+struct ftl_zone {
+ int initialized;
+ s16 *lba_to_phys_table; /* LBA to physical table */
+ struct kfifo free_sectors; /* queue of free sectors */
+};
+
+struct cached_block {
+ int zone;
+ unsigned long lba;
+ unsigned char *data;
+ long unsigned int data_invalid_bitmap;
+ struct list_head list_member;
+};
+
+struct sm_ftl {
+ struct mtd_blktrans_dev *trans;
+ struct ftl_zone *zones;
+ struct list_head cache;
+ struct list_head free_cache;
+ struct mutex cache_mutex;
+ struct completion erase_completion;
+ struct task_struct *flush_thread;
+ int erase_error;
+
+ int block_size; /* block size in bytes */
+ int zone_size; /* zone size in blocks */
+ int zone_count; /* number of zones */
+ int max_lba; /* maximum lba in a zone */
+ int smallpagenand; /* 256 bytes/page nand */
+
+ int readonly;
+
+ /* geometry stuff */
+ int heads;
+ int sectors;
+ int cylinders;
+
+ /*Misc */
+ int cis_block;
+};
+
+struct chs_entry {
+ unsigned long size;
+ unsigned short cyl;
+ unsigned char head;
+ unsigned char sec;
+};
+
+
+#define SM_FTL_PARTN_BITS 3
+
+#define dbg(format, ...) \
+ printk(KERN_ERR "sm_ftl" ": " format "\n", ## __VA_ARGS__)
--
1.6.3.3




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