-/*
+/*
* Direct MTD block device access
*
- * $Id: mtdblock.c,v 1.66 2004/11/25 13:52:52 joern Exp $
- *
- * (C) 2000-2003 Nicolas Pitre <nico@cam.org>
+ * (C) 2000-2003 Nicolas Pitre <nico@fluxnic.net>
* (C) 1999-2003 David Woodhouse <dwmw2@infradead.org>
*/
-#include <linux/config.h>
-#include <linux/types.h>
-#include <linux/module.h>
-#include <linux/kernel.h>
#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/sched.h> /* TASK_* */
+
#include <linux/mtd/mtd.h>
#include <linux/mtd/blktrans.h>
+#include <linux/mutex.h>
-static struct mtdblk_dev {
- struct mtd_info *mtd;
+
+struct mtdblk_dev {
+ struct mtd_blktrans_dev mbd;
int count;
- struct semaphore cache_sem;
+ 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;
-} *mtdblks[MAX_MTD_DEVICES];
+};
+
+static struct 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
wake_up(wait_q);
}
-static int erase_write (struct mtd_info *mtd, unsigned long pos,
+static int erase_write (struct mtd_info *mtd, unsigned long pos,
int len, const char *buf)
{
struct erase_info erase;
set_current_state(TASK_INTERRUPTIBLE);
add_wait_queue(&wait_q, &wait);
- ret = MTD_ERASE(mtd, &erase);
+ ret = mtd->erase(mtd, &erase);
if (ret) {
set_current_state(TASK_RUNNING);
remove_wait_queue(&wait_q, &wait);
remove_wait_queue(&wait_q, &wait);
/*
- * Next, writhe data to flash.
+ * Next, write the data to flash.
*/
- ret = MTD_WRITE (mtd, pos, len, &retlen, buf);
+ ret = mtd->write(mtd, pos, len, &retlen, buf);
if (ret)
return ret;
if (retlen != len)
static int write_cached_data (struct mtdblk_dev *mtdblk)
{
- struct mtd_info *mtd = mtdblk->mtd;
+ struct mtd_info *mtd = mtdblk->mbd.mtd;
int ret;
if (mtdblk->cache_state != STATE_DIRTY)
return 0;
DEBUG(MTD_DEBUG_LEVEL2, "mtdblock: writing cached data for \"%s\" "
- "at 0x%lx, size 0x%x\n", mtd->name,
+ "at 0x%lx, size 0x%x\n", mtd->name,
mtdblk->cache_offset, mtdblk->cache_size);
-
- ret = erase_write (mtd, mtdblk->cache_offset,
+
+ ret = erase_write (mtd, mtdblk->cache_offset,
mtdblk->cache_size, mtdblk->cache_data);
if (ret)
return ret;
/*
* Here we could argubly 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
+ * 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.
*/
}
-static int do_cached_write (struct mtdblk_dev *mtdblk, unsigned long pos,
+static int do_cached_write (struct mtdblk_dev *mtdblk, unsigned long pos,
int len, const char *buf)
{
- struct mtd_info *mtd = mtdblk->mtd;
+ struct mtd_info *mtd = mtdblk->mbd.mtd;
unsigned int sect_size = mtdblk->cache_size;
size_t retlen;
int ret;
DEBUG(MTD_DEBUG_LEVEL2, "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);
+ 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 )
+ 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.
if (mtdblk->cache_state == STATE_DIRTY &&
mtdblk->cache_offset != sect_start) {
ret = write_cached_data(mtdblk);
- if (ret)
+ if (ret)
return ret;
}
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);
+ ret = mtd->read(mtd, sect_start, sect_size,
+ &retlen, mtdblk->cache_data);
if (ret)
return ret;
if (retlen != sect_size)
}
-static int do_cached_read (struct mtdblk_dev *mtdblk, unsigned long pos,
+static int do_cached_read (struct mtdblk_dev *mtdblk, unsigned long pos,
int len, char *buf)
{
- struct mtd_info *mtd = mtdblk->mtd;
+ struct mtd_info *mtd = mtdblk->mbd.mtd;
unsigned int sect_size = mtdblk->cache_size;
size_t retlen;
int ret;
- DEBUG(MTD_DEBUG_LEVEL2, "mtdblock: read on \"%s\" at 0x%lx, size 0x%x\n",
+ DEBUG(MTD_DEBUG_LEVEL2, "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);
+ 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)
+ if (size > len)
size = len;
/*
mtdblk->cache_offset == sect_start) {
memcpy (buf, mtdblk->cache_data + offset, size);
} else {
- ret = MTD_READ (mtd, pos, size, &retlen, buf);
+ ret = mtd->read(mtd, pos, size, &retlen, buf);
if (ret)
return ret;
if (retlen != size)
static int mtdblock_readsect(struct mtd_blktrans_dev *dev,
unsigned long block, char *buf)
{
- struct mtdblk_dev *mtdblk = mtdblks[dev->devnum];
+ 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 = mtdblks[dev->devnum];
+ struct mtdblk_dev *mtdblk = container_of(dev, struct mtdblk_dev, mbd);
if (unlikely(!mtdblk->cache_data && mtdblk->cache_size)) {
- mtdblk->cache_data = vmalloc(mtdblk->mtd->erasesize);
+ 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
static int mtdblock_open(struct mtd_blktrans_dev *mbd)
{
- struct mtdblk_dev *mtdblk;
- struct mtd_info *mtd = mbd->mtd;
- int dev = mbd->devnum;
+ struct mtdblk_dev *mtdblk = container_of(mbd, struct mtdblk_dev, mbd);
DEBUG(MTD_DEBUG_LEVEL1,"mtdblock_open\n");
-
- if (mtdblks[dev]) {
- mtdblks[dev]->count++;
+
+ 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 = kmalloc(sizeof(struct mtdblk_dev), GFP_KERNEL);
- if (!mtdblk)
- return -ENOMEM;
- memset(mtdblk, 0, sizeof(*mtdblk));
+ /* OK, it's not open. Create cache info for it */
mtdblk->count = 1;
- mtdblk->mtd = mtd;
-
- init_MUTEX (&mtdblk->cache_sem);
+ mutex_init(&mtdblk->cache_mutex);
mtdblk->cache_state = STATE_EMPTY;
- if ((mtdblk->mtd->flags & MTD_CAP_RAM) != MTD_CAP_RAM &&
- mtdblk->mtd->erasesize) {
- mtdblk->cache_size = mtdblk->mtd->erasesize;
+ if (!(mbd->mtd->flags & MTD_NO_ERASE) && mbd->mtd->erasesize) {
+ mtdblk->cache_size = mbd->mtd->erasesize;
mtdblk->cache_data = NULL;
}
- mtdblks[dev] = mtdblk;
-
+ mutex_unlock(&mtdblks_lock);
+
DEBUG(MTD_DEBUG_LEVEL1, "ok\n");
return 0;
static int mtdblock_release(struct mtd_blktrans_dev *mbd)
{
- int dev = mbd->devnum;
- struct mtdblk_dev *mtdblk = mtdblks[dev];
+ struct mtdblk_dev *mtdblk = container_of(mbd, struct mtdblk_dev, mbd);
DEBUG(MTD_DEBUG_LEVEL1, "mtdblock_release\n");
- down(&mtdblk->cache_sem);
+ mutex_lock(&mtdblks_lock);
+
+ mutex_lock(&mtdblk->cache_mutex);
write_cached_data(mtdblk);
- up(&mtdblk->cache_sem);
+ mutex_unlock(&mtdblk->cache_mutex);
if (!--mtdblk->count) {
- /* It was the last usage. Free the device */
- mtdblks[dev] = NULL;
- if (mtdblk->mtd->sync)
- mtdblk->mtd->sync(mtdblk->mtd);
+ /* It was the last usage. Free the cache */
+ if (mbd->mtd->sync)
+ mbd->mtd->sync(mbd->mtd);
vfree(mtdblk->cache_data);
- kfree(mtdblk);
}
+
+ mutex_unlock(&mtdblks_lock);
+
DEBUG(MTD_DEBUG_LEVEL1, "ok\n");
return 0;
-}
+}
static int mtdblock_flush(struct mtd_blktrans_dev *dev)
{
- struct mtdblk_dev *mtdblk = mtdblks[dev->devnum];
+ struct mtdblk_dev *mtdblk = container_of(dev, struct mtdblk_dev, mbd);
- down(&mtdblk->cache_sem);
+ mutex_lock(&mtdblk->cache_mutex);
write_cached_data(mtdblk);
- up(&mtdblk->cache_sem);
+ mutex_unlock(&mtdblk->cache_mutex);
- if (mtdblk->mtd->sync)
- mtdblk->mtd->sync(mtdblk->mtd);
+ if (dev->mtd->sync)
+ dev->mtd->sync(dev->mtd);
return 0;
}
static void mtdblock_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
{
- struct mtd_blktrans_dev *dev = kmalloc(sizeof(*dev), GFP_KERNEL);
+ struct mtdblk_dev *dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev)
return;
- memset(dev, 0, sizeof(*dev));
+ dev->mbd.mtd = mtd;
+ dev->mbd.devnum = mtd->index;
- dev->mtd = mtd;
- dev->devnum = mtd->index;
- dev->blksize = 512;
- dev->size = mtd->size >> 9;
- dev->tr = tr;
+ dev->mbd.size = mtd->size >> 9;
+ dev->mbd.tr = tr;
if (!(mtd->flags & MTD_WRITEABLE))
- dev->readonly = 1;
+ dev->mbd.readonly = 1;
- add_mtd_blktrans_dev(dev);
+ if (add_mtd_blktrans_dev(&dev->mbd))
+ kfree(dev);
}
static void mtdblock_remove_dev(struct mtd_blktrans_dev *dev)
{
del_mtd_blktrans_dev(dev);
- kfree(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,
static int __init init_mtdblock(void)
{
+ mutex_init(&mtdblks_lock);
+
return register_mtd_blktrans(&mtdblock_tr);
}
MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Nicolas Pitre <nico@cam.org> et al.");
+MODULE_AUTHOR("Nicolas Pitre <nico@fluxnic.net> et al.");
MODULE_DESCRIPTION("Caching read/erase/writeback block device emulation access to MTD devices");
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff