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Subject[PATCH 14/15] MTD: Add new SmartMedia/xD FTL
Date
This implements new readwrite SmartMedia/xd FTL.

mtd driver must have support proper ECC and badblock vertification
based on oob parts for 512 bytes nand.

Also mtd driver must define read_oob and write_oob, which are used
to read and write both data and oob together.

Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
---
drivers/mtd/Kconfig | 21 +
drivers/mtd/Makefile | 1 +
drivers/mtd/sm_ftl.c | 1284 ++++++++++++++++++++++++++++++++++++++++++++++++++
drivers/mtd/sm_ftl.h | 94 ++++
4 files changed, 1400 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 ecf90f5..0105ae0 100644
--- a/drivers/mtd/Kconfig
+++ b/drivers/mtd/Kconfig
@@ -304,6 +304,27 @@ 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 && BLOCK
+ select MTD_BLKDEVS
+ 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 SM_FTL_MUSEUM
+ boolean "Additional Support for 1MB and 2MB SmartMedia cards"
+ depends on SM_FTL && MTD_NAND
+ select MTD_NAND_ECC_SMC
+ help
+ Very old SmartMedia cards need ECC to be caluculated in the FTL
+ Such cards are very rare, thus enabling this option is mostly useless
+ Also this support is completely UNTESTED.
+
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 82d1e4d..d53357b 100644
--- a/drivers/mtd/Makefile
+++ b/drivers/mtd/Makefile
@@ -24,6 +24,7 @@ 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..c2a409f
--- /dev/null
+++ b/drivers/mtd/sm_ftl.c
@@ -0,0 +1,1284 @@
+/*
+ * 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/sysfs.h>
+#include <linux/bitops.h>
+#include "nand/sm_common.h"
+#include "sm_ftl.h"
+
+#ifdef CONFIG_SM_FTL_MUSEUM
+#include <linux/mtd/nand_ecc.h>
+#endif
+
+
+struct workqueue_struct *cache_flush_workqueue;
+
+static int cache_timeout = 1000;
+module_param(cache_timeout, bool, 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 attributtes ---------------------------------- */
+struct sm_sysfs_attribute {
+ struct device_attribute dev_attr;
+ char *data;
+ int len;
+};
+
+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
+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;
+
+ int vendor_len = strnlen(ftl->cis_buffer + SM_CIS_VENDOR_OFFSET,
+ SM_SMALL_PAGE - SM_CIS_VENDOR_OFFSET);
+
+ char *vendor = kmalloc(vendor_len, GFP_KERNEL);
+ memcpy(vendor, ftl->cis_buffer + SM_CIS_VENDOR_OFFSET, vendor_len);
+ vendor[vendor_len] = 0;
+
+ /* Initialize sysfs attributes */
+ vendor_attribute =
+ kzalloc(sizeof(struct sm_sysfs_attribute), GFP_KERNEL);
+
+ vendor_attribute->data = vendor;
+ vendor_attribute->len = vendor_len;
+ 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 = kzalloc(sizeof(struct attribute *) * (NUM_ATTRIBUTES + 1),
+ GFP_KERNEL);
+ attributes[0] = &vendor_attribute->dev_attr.attr;
+
+ /* Finally create the attribute group */
+ attr_group = kzalloc(sizeof(struct attribute_group), GFP_KERNEL);
+ attr_group->attrs = attributes;
+ return attr_group;
+}
+
+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(u8 *lba)
+{
+ /* check fixed bits */
+ if ((lba[0] & 0xF8) != 0x10)
+ return -2;
+
+ /* check parity - endianess doesn't matter */
+ if (hweight16(*(u16 *)lba) & 1)
+ return -2;
+
+ return (lba[1] >> 1) | ((lba[0] & 0x07) << 7);
+}
+
+
+/*
+ * Read LBA asscociated with block
+ * returns -1, if block is erased
+ * returns -2 if error happens
+ */
+static int sm_read_lba(struct sm_oob *oob)
+{
+ static const u32 erased_pattern[4] = {
+ 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
+
+ u16 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 = *(u16 *)oob->lba_copy1 ^ *(u16*)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, u16 lba)
+{
+ u8 tmp[2];
+
+ WARN_ON(lba >= 1000);
+
+ tmp[0] = 0x10 | ((lba >> 7) & 0x07);
+ tmp[1] = (lba << 1) & 0xFF;
+
+ if (hweight16(*(u16 *)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 offset,
+ int *zone, int *block, int *boffset)
+{
+ *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(u8 *buffer, struct sm_oob *oob)
+{
+#ifdef CONFIG_SM_FTL_MUSEUM
+ u8 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;
+#endif
+ return 0;
+}
+
+/* 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_info *mtd = ftl->trans->mtd;
+ struct mtd_oob_ops ops;
+ struct sm_oob tmp_oob;
+ int ret;
+ 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 vertification */
+ if (!oob)
+ oob = &tmp_oob;
+
+ ops.mode = ftl->smallpagenand ? MTD_OOB_RAW : MTD_OOB_PLACE;
+ 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;
+ }
+
+ /* Unfortunelly, 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 && ret != -EUCLEAN && ret != -EBADMSG) {
+ 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 (ret == -EBADMSG ||
+ (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,
+ u8 *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_OOB_RAW : MTD_OOB_PLACE;
+ 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 you are paranoid, use CONFIG_MTD_NAND_VERIFY_WRITE */
+
+ 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, u8 *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"
+ " coudn't be read, marking it as invalid",
+ boffset / SM_SECTOR_SIZE, lba, zone);
+
+ oob.data_status = 0;
+ }
+
+#ifdef CONFIG_SM_FTL_MUSEUM
+ 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);
+ }
+#endif
+ 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 completly */
+ 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 succedes, it updates free block fifo, otherwise marks block as bad
+ */
+static int sm_erase_block(struct sm_ftl *ftl, int zone_num, u16 block,
+ int put_free)
+{
+ struct ftl_zone *zone = &ftl->zones[zone_num];
+ struct mtd_info *mtd = ftl->trans->mtd;
+ struct erase_info erase;
+
+ erase.mtd = 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 (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 (erase.state == MTD_ERASE_PENDING)
+ wait_for_completion(&ftl->erase_completion);
+
+ if (erase.state != MTD_ERASE_DONE) {
+ sm_printk("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, sizeof(block));
+
+ return 0;
+error:
+ sm_mark_block_bad(ftl, zone_num, block);
+ return -EIO;
+}
+
+static void sm_erase_callback(struct erase_info *self)
+{
+ struct sm_ftl *ftl = (struct sm_ftl *)self->priv;
+ complete(&ftl->erase_completion);
+}
+
+/* Throughtly 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 shoudn'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 (partialy 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 u8 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 */
+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 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 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 {
+
+ if (!ftl->readonly)
+ return -ENODEV;
+
+ 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. Also, 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,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 these functions for IO */
+ if (!mtd->read_oob || !mtd->write_oob)
+ 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;
+ u16 block;
+ int lba;
+ int i = 0;
+
+ dbg("initializing zone %d", zone_num);
+
+ /* Allocate memory for FTL table */
+ zone->lba_to_phys_table = kmalloc(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--) {
+ kfifo_out(&zone->free_sectors, (unsigned char *)&block, 2);
+ kfifo_in(&zone->free_sectors, (const unsigned char *)&block, 2);
+ }
+ return 0;
+}
+
+/* Get and automaticly initialize an FTL mapping for one zone */
+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 */
+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 */
+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 */
+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 */
+int sm_cache_flush(struct sm_ftl *ftl)
+{
+ struct ftl_zone *zone;
+
+ int sector_num;
+ u16 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_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;
+ /* 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, 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(unsigned long data)
+{
+ struct sm_ftl *ftl = (struct sm_ftl *)data;
+ 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, 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 int 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);
+ 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;
+}
+
+/* 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);
+ setup_timer(&ftl->timer, sm_cache_flush_timer, (unsigned long)ftl);
+ INIT_WORK(&ftl->flush_work, sm_cache_flush_work);
+ init_completion(&ftl->erase_completion);
+
+ /* 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 = kzalloc(sizeof(struct ftl_zone) * ftl->zone_count,
+ 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);
+ 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 = -1,
+ .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_freezeable_workqueue("smflush");
+
+ if (IS_ERR(cache_flush_workqueue))
+ return PTR_ERR(cache_flush_workqueue);
+
+ 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");
diff --git a/drivers/mtd/sm_ftl.h b/drivers/mtd/sm_ftl.h
new file mode 100644
index 0000000..519e2e1
--- /dev/null
+++ b/drivers/mtd/sm_ftl.h
@@ -0,0 +1,94 @@
+/*
+ * 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/blktrans.h>
+#include <linux/kfifo.h>
+#include <linux/sched.h>
+#include <linux/completion.h>
+#include <linux/mtd/mtd.h>
+
+
+
+struct ftl_zone {
+ int initialized;
+ s16 *lba_to_phys_table; /* LBA to physical table */
+ struct kfifo free_sectors; /* queue of free sectors */
+};
+
+struct sm_ftl {
+ struct mtd_blktrans_dev *trans;
+
+ struct mutex mutex; /* protects the structure */
+ struct ftl_zone *zones; /* FTL tables for each zone */
+
+ /* Media information */
+ 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; /* is FS readonly */
+ int unstable;
+ int cis_block; /* CIS block location */
+ int cis_boffset; /* CIS offset in the block */
+ int cis_page_offset; /* CIS offset in the page */
+ void *cis_buffer; /* tmp buffer for cis reads */
+
+ /* Cache */
+ int cache_block; /* block number of cached block */
+ int cache_zone; /* zone of cached block */
+ unsigned char *cache_data; /* cached block data */
+ long unsigned int cache_data_invalid_bitmap;
+ int cache_clean;
+ struct work_struct flush_work;
+ struct timer_list timer;
+
+ /* Async erase stuff */
+ struct completion erase_completion;
+
+ /* Geometry stuff */
+ int heads;
+ int sectors;
+ int cylinders;
+
+ struct attribute_group *disk_attributes;
+};
+
+struct chs_entry {
+ unsigned long size;
+ unsigned short cyl;
+ unsigned char head;
+ unsigned char sec;
+};
+
+
+#define SM_FTL_PARTN_BITS 3
+
+#define sm_printk(format, ...) \
+ printk(KERN_WARNING "sm_ftl" ": " format "\n", ## __VA_ARGS__)
+
+#define dbg(format, ...) \
+ if (debug) \
+ printk(KERN_DEBUG "sm_ftl" ": " format "\n", ## __VA_ARGS__)
+
+#define dbg_verbose(format, ...) \
+ if (debug > 1) \
+ printk(KERN_DEBUG "sm_ftl" ": " format "\n", ## __VA_ARGS__)
+
+
+static void sm_erase_callback(struct erase_info *self);
+static int sm_erase_block(struct sm_ftl *ftl, int zone_num, u16 block,
+ int put_free);
+static void sm_mark_block_bad(struct sm_ftl *ftl, int zone_num, int block);
+
+static int sm_recheck_media(struct sm_ftl *ftl);
--
1.6.3.3


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