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Diffstat (limited to 'ANDROID_3.4.5/drivers/mtd/mtdblock.c')
-rw-r--r--ANDROID_3.4.5/drivers/mtd/mtdblock.c407
1 files changed, 0 insertions, 407 deletions
diff --git a/ANDROID_3.4.5/drivers/mtd/mtdblock.c b/ANDROID_3.4.5/drivers/mtd/mtdblock.c
deleted file mode 100644
index 6c6d8073..00000000
--- a/ANDROID_3.4.5/drivers/mtd/mtdblock.c
+++ /dev/null
@@ -1,407 +0,0 @@
-/*
- * Direct MTD block device access
- *
- * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
- * Copyright © 2000-2003 Nicolas Pitre <nico@fluxnic.net>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
- *
- */
-
-#include <linux/fs.h>
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/slab.h>
-#include <linux/types.h>
-#include <linux/vmalloc.h>
-
-#include <linux/mtd/mtd.h>
-#include <linux/mtd/blktrans.h>
-#include <linux/mutex.h>
-
-
-struct mtdblk_dev {
- struct mtd_blktrans_dev mbd;
- int count;
- struct mutex cache_mutex;
- unsigned char *cache_data;
- unsigned long cache_offset;
- unsigned int cache_size;
- enum { STATE_EMPTY, STATE_CLEAN, STATE_DIRTY } cache_state;
-};
-
-static DEFINE_MUTEX(mtdblks_lock);
-
-/*
- * Cache stuff...
- *
- * Since typical flash erasable sectors are much larger than what Linux's
- * buffer cache can handle, we must implement read-modify-write on flash
- * sectors for each block write requests. To avoid over-erasing flash sectors
- * and to speed things up, we locally cache a whole flash sector while it is
- * being written to until a different sector is required.
- */
-
-static void erase_callback(struct erase_info *done)
-{
- wait_queue_head_t *wait_q = (wait_queue_head_t *)done->priv;
- wake_up(wait_q);
-}
-
-static int erase_write (struct mtd_info *mtd, unsigned long pos,
- int len, const char *buf)
-{
- struct erase_info erase;
- DECLARE_WAITQUEUE(wait, current);
- wait_queue_head_t wait_q;
- size_t retlen;
- int ret;
-
- /*
- * First, let's erase the flash block.
- */
-
- init_waitqueue_head(&wait_q);
- erase.mtd = mtd;
- erase.callback = erase_callback;
- erase.addr = pos;
- erase.len = len;
- erase.priv = (u_long)&wait_q;
-
- set_current_state(TASK_INTERRUPTIBLE);
- add_wait_queue(&wait_q, &wait);
-
- ret = mtd_erase(mtd, &erase);
- if (ret) {
- set_current_state(TASK_RUNNING);
- remove_wait_queue(&wait_q, &wait);
- printk (KERN_WARNING "mtdblock: erase of region [0x%lx, 0x%x] "
- "on \"%s\" failed\n",
- pos, len, mtd->name);
- return ret;
- }
-
- schedule(); /* Wait for erase to finish. */
- remove_wait_queue(&wait_q, &wait);
-
- /*
- * Next, write the data to flash.
- */
-
- ret = mtd_write(mtd, pos, len, &retlen, buf);
- if (ret)
- return ret;
- if (retlen != len)
- return -EIO;
- return 0;
-}
-
-
-static int write_cached_data (struct mtdblk_dev *mtdblk)
-{
- struct mtd_info *mtd = mtdblk->mbd.mtd;
- int ret;
-
- if (mtdblk->cache_state != STATE_DIRTY)
- return 0;
-
- pr_debug("mtdblock: writing cached data for \"%s\" "
- "at 0x%lx, size 0x%x\n", mtd->name,
- mtdblk->cache_offset, mtdblk->cache_size);
-
- ret = erase_write (mtd, mtdblk->cache_offset,
- mtdblk->cache_size, mtdblk->cache_data);
- if (ret)
- return ret;
-
- /*
- * Here we could arguably set the cache state to STATE_CLEAN.
- * However this could lead to inconsistency since we will not
- * be notified if this content is altered on the flash by other
- * means. Let's declare it empty and leave buffering tasks to
- * the buffer cache instead.
- */
- mtdblk->cache_state = STATE_EMPTY;
- return 0;
-}
-
-
-static int do_cached_write (struct mtdblk_dev *mtdblk, unsigned long pos,
- int len, const char *buf)
-{
- struct mtd_info *mtd = mtdblk->mbd.mtd;
- unsigned int sect_size = mtdblk->cache_size;
- size_t retlen;
- int ret;
-
- pr_debug("mtdblock: write on \"%s\" at 0x%lx, size 0x%x\n",
- mtd->name, pos, len);
-
- if (!sect_size)
- return mtd_write(mtd, pos, len, &retlen, buf);
-
- while (len > 0) {
- unsigned long sect_start = (pos/sect_size)*sect_size;
- unsigned int offset = pos - sect_start;
- unsigned int size = sect_size - offset;
- if( size > len )
- size = len;
-
- if (size == sect_size) {
- /*
- * We are covering a whole sector. Thus there is no
- * need to bother with the cache while it may still be
- * useful for other partial writes.
- */
- ret = erase_write (mtd, pos, size, buf);
- if (ret)
- return ret;
- } else {
- /* Partial sector: need to use the cache */
-
- if (mtdblk->cache_state == STATE_DIRTY &&
- mtdblk->cache_offset != sect_start) {
- ret = write_cached_data(mtdblk);
- if (ret)
- return ret;
- }
-
- if (mtdblk->cache_state == STATE_EMPTY ||
- mtdblk->cache_offset != sect_start) {
- /* fill the cache with the current sector */
- mtdblk->cache_state = STATE_EMPTY;
- ret = mtd_read(mtd, sect_start, sect_size,
- &retlen, mtdblk->cache_data);
- if (ret)
- return ret;
- if (retlen != sect_size)
- return -EIO;
-
- mtdblk->cache_offset = sect_start;
- mtdblk->cache_size = sect_size;
- mtdblk->cache_state = STATE_CLEAN;
- }
-
- /* write data to our local cache */
- memcpy (mtdblk->cache_data + offset, buf, size);
- mtdblk->cache_state = STATE_DIRTY;
- }
-
- buf += size;
- pos += size;
- len -= size;
- }
-
- return 0;
-}
-
-
-static int do_cached_read (struct mtdblk_dev *mtdblk, unsigned long pos,
- int len, char *buf)
-{
- struct mtd_info *mtd = mtdblk->mbd.mtd;
- unsigned int sect_size = mtdblk->cache_size;
- size_t retlen;
- int ret;
-
- pr_debug("mtdblock: read on \"%s\" at 0x%lx, size 0x%x\n",
- mtd->name, pos, len);
-
- if (!sect_size)
- return mtd_read(mtd, pos, len, &retlen, buf);
-
- while (len > 0) {
- unsigned long sect_start = (pos/sect_size)*sect_size;
- unsigned int offset = pos - sect_start;
- unsigned int size = sect_size - offset;
- if (size > len)
- size = len;
-
- /*
- * Check if the requested data is already cached
- * Read the requested amount of data from our internal cache if it
- * contains what we want, otherwise we read the data directly
- * from flash.
- */
- if (mtdblk->cache_state != STATE_EMPTY &&
- mtdblk->cache_offset == sect_start) {
- memcpy (buf, mtdblk->cache_data + offset, size);
- } else {
- ret = mtd_read(mtd, pos, size, &retlen, buf);
- if (ret)
- return ret;
- if (retlen != size)
- return -EIO;
- }
-
- buf += size;
- pos += size;
- len -= size;
- }
-
- return 0;
-}
-
-static int mtdblock_readsect(struct mtd_blktrans_dev *dev,
- unsigned long block, char *buf)
-{
- struct mtdblk_dev *mtdblk = container_of(dev, struct mtdblk_dev, mbd);
- return do_cached_read(mtdblk, block<<9, 512, buf);
-}
-
-static int mtdblock_writesect(struct mtd_blktrans_dev *dev,
- unsigned long block, char *buf)
-{
- struct mtdblk_dev *mtdblk = container_of(dev, struct mtdblk_dev, mbd);
- if (unlikely(!mtdblk->cache_data && mtdblk->cache_size)) {
- mtdblk->cache_data = vmalloc(mtdblk->mbd.mtd->erasesize);
- if (!mtdblk->cache_data)
- return -EINTR;
- /* -EINTR is not really correct, but it is the best match
- * documented in man 2 write for all cases. We could also
- * return -EAGAIN sometimes, but why bother?
- */
- }
- return do_cached_write(mtdblk, block<<9, 512, buf);
-}
-
-static int mtdblock_open(struct mtd_blktrans_dev *mbd)
-{
- struct mtdblk_dev *mtdblk = container_of(mbd, struct mtdblk_dev, mbd);
-
- pr_debug("mtdblock_open\n");
-
- mutex_lock(&mtdblks_lock);
- if (mtdblk->count) {
- mtdblk->count++;
- mutex_unlock(&mtdblks_lock);
- return 0;
- }
-
- /* OK, it's not open. Create cache info for it */
- mtdblk->count = 1;
- mutex_init(&mtdblk->cache_mutex);
- mtdblk->cache_state = STATE_EMPTY;
- if (!(mbd->mtd->flags & MTD_NO_ERASE) && mbd->mtd->erasesize) {
- mtdblk->cache_size = mbd->mtd->erasesize;
- mtdblk->cache_data = NULL;
- }
-
- mutex_unlock(&mtdblks_lock);
-
- pr_debug("ok\n");
-
- return 0;
-}
-
-static int mtdblock_release(struct mtd_blktrans_dev *mbd)
-{
- struct mtdblk_dev *mtdblk = container_of(mbd, struct mtdblk_dev, mbd);
-
- pr_debug("mtdblock_release\n");
-
- mutex_lock(&mtdblks_lock);
-
- mutex_lock(&mtdblk->cache_mutex);
- write_cached_data(mtdblk);
- mutex_unlock(&mtdblk->cache_mutex);
-
- if (!--mtdblk->count) {
- /*
- * It was the last usage. Free the cache, but only sync if
- * opened for writing.
- */
- if (mbd->file_mode & FMODE_WRITE)
- mtd_sync(mbd->mtd);
- vfree(mtdblk->cache_data);
- }
-
- mutex_unlock(&mtdblks_lock);
-
- pr_debug("ok\n");
-
- return 0;
-}
-
-static int mtdblock_flush(struct mtd_blktrans_dev *dev)
-{
- struct mtdblk_dev *mtdblk = container_of(dev, struct mtdblk_dev, mbd);
-
- mutex_lock(&mtdblk->cache_mutex);
- write_cached_data(mtdblk);
- mutex_unlock(&mtdblk->cache_mutex);
- mtd_sync(dev->mtd);
- return 0;
-}
-
-static void mtdblock_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
-{
- struct mtdblk_dev *dev = kzalloc(sizeof(*dev), GFP_KERNEL);
-
- if (!dev)
- return;
-
- dev->mbd.mtd = mtd;
- dev->mbd.devnum = mtd->index;
-
- dev->mbd.size = mtd->size >> 9;
- dev->mbd.tr = tr;
-
- if (!(mtd->flags & MTD_WRITEABLE))
- dev->mbd.readonly = 1;
-
- if (add_mtd_blktrans_dev(&dev->mbd))
- kfree(dev);
-}
-
-static void mtdblock_remove_dev(struct mtd_blktrans_dev *dev)
-{
- del_mtd_blktrans_dev(dev);
-}
-
-static struct mtd_blktrans_ops mtdblock_tr = {
- .name = "mtdblock",
- .major = 31,
- .part_bits = 0,
- .blksize = 512,
- .open = mtdblock_open,
- .flush = mtdblock_flush,
- .release = mtdblock_release,
- .readsect = mtdblock_readsect,
- .writesect = mtdblock_writesect,
- .add_mtd = mtdblock_add_mtd,
- .remove_dev = mtdblock_remove_dev,
- .owner = THIS_MODULE,
-};
-
-static int __init init_mtdblock(void)
-{
- return register_mtd_blktrans(&mtdblock_tr);
-}
-
-static void __exit cleanup_mtdblock(void)
-{
- deregister_mtd_blktrans(&mtdblock_tr);
-}
-
-module_init(init_mtdblock);
-module_exit(cleanup_mtdblock);
-
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Nicolas Pitre <nico@fluxnic.net> et al.");
-MODULE_DESCRIPTION("Caching read/erase/writeback block device emulation access to MTD devices");