1 files changed, 823 insertions, 0 deletions

diff --git a/drivers/mtd/devices/blkmtd.c b/drivers/mtd/devices/blkmtd.c
new file mode 100644
index 000000000000..662e807801ed
--- /dev/null
+++ b/drivers/mtd/devices/blkmtd.c
@@ -0,0 +1,823 @@
+/*
+ * $Id: blkmtd.c,v 1.24 2004/11/16 18:29:01 dwmw2 Exp $
+ *
+ * blkmtd.c - use a block device as a fake MTD
+ *
+ * Author: Simon Evans <spse@secret.org.uk>
+ *
+ * Copyright (C) 2001,2002 Simon Evans
+ *
+ * Licence: GPL
+ *
+ * How it works:
+ *      The driver uses raw/io to read/write the device and the page
+ *      cache to cache access. Writes update the page cache with the
+ *      new data and mark it dirty and add the page into a BIO which
+ *      is then written out.
+ *
+ *      It can be loaded Read-Only to prevent erases and writes to the
+ *      medium.
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/blkdev.h>
+#include <linux/bio.h>
+#include <linux/pagemap.h>
+#include <linux/list.h>
+#include <linux/init.h>
+#include <linux/mtd/mtd.h>
+
+
+#define err(format, arg...) printk(KERN_ERR "blkmtd: " format "\n" , ## arg)
+#define info(format, arg...) printk(KERN_INFO "blkmtd: " format "\n" , ## arg)
+#define warn(format, arg...) printk(KERN_WARNING "blkmtd: " format "\n" , ## arg)
+#define crit(format, arg...) printk(KERN_CRIT "blkmtd: " format "\n" , ## arg)
+
+
+/* Default erase size in K, always make it a multiple of PAGE_SIZE */
+#define CONFIG_MTD_BLKDEV_ERASESIZE (128 << 10) /* 128KiB */
+#define VERSION "$Revision: 1.24 $"
+
+/* Info for the block device */
+struct blkmtd_dev {
+        struct list_head list;
+        struct block_device *blkdev;
+        struct mtd_info mtd_info;
+        struct semaphore wrbuf_mutex;
+};
+
+
+/* Static info about the MTD, used in cleanup_module */
+static LIST_HEAD(blkmtd_device_list);
+
+
+static void blkmtd_sync(struct mtd_info *mtd);
+
+#define MAX_DEVICES 4
+
+/* Module parameters passed by insmod/modprobe */
+static char *device[MAX_DEVICES];    /* the block device to use */
+static int erasesz[MAX_DEVICES];     /* optional default erase size */
+static int ro[MAX_DEVICES];          /* optional read only flag */
+static int sync;
+
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Simon Evans <spse@secret.org.uk>");
+MODULE_DESCRIPTION("Emulate an MTD using a block device");
+module_param_array(device, charp, NULL, 0);
+MODULE_PARM_DESC(device, "block device to use");
+module_param_array(erasesz, int, NULL, 0);
+MODULE_PARM_DESC(erasesz, "optional erase size to use in KiB. eg 4=4KiB.");
+module_param_array(ro, bool, NULL, 0);
+MODULE_PARM_DESC(ro, "1=Read only, writes and erases cause errors");
+module_param(sync, bool, 0);
+MODULE_PARM_DESC(sync, "1=Synchronous writes");
+
+
+/* completion handler for BIO reads */
+static int bi_read_complete(struct bio *bio, unsigned int bytes_done, int error)
+{
+        if (bio->bi_size)
+                return 1;
+
+        complete((struct completion*)bio->bi_private);
+        return 0;
+}
+
+
+/* completion handler for BIO writes */
+static int bi_write_complete(struct bio *bio, unsigned int bytes_done, int error)
+{
+        const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
+        struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
+
+        if (bio->bi_size)
+                return 1;
+
+        if(!uptodate)
+                err("bi_write_complete: not uptodate\n");
+
+        do {
+                struct page *page = bvec->bv_page;
+                DEBUG(3, "Cleaning up page %ld\n", page->index);
+                if (--bvec >= bio->bi_io_vec)
+                        prefetchw(&bvec->bv_page->flags);
+
+                if (uptodate) {
+                        SetPageUptodate(page);
+                } else {
+                        ClearPageUptodate(page);
+                        SetPageError(page);
+                }
+                ClearPageDirty(page);
+                unlock_page(page);
+                page_cache_release(page);
+        } while (bvec >= bio->bi_io_vec);
+        
+        complete((struct completion*)bio->bi_private);
+        return 0;
+}
+
+
+/* read one page from the block device */
+static int blkmtd_readpage(struct blkmtd_dev *dev, struct page *page)
+{
+        struct bio *bio;
+        struct completion event;
+        int err = -ENOMEM;
+
+        if(PageUptodate(page)) {
+                DEBUG(2, "blkmtd: readpage page %ld is already upto date\n", page->index);
+                unlock_page(page);
+                return 0;
+        }
+        
+        ClearPageUptodate(page);
+        ClearPageError(page);
+
+        bio = bio_alloc(GFP_KERNEL, 1);
+        if(bio) {
+                init_completion(&event);
+                bio->bi_bdev = dev->blkdev;
+                bio->bi_sector = page->index << (PAGE_SHIFT-9);
+                bio->bi_private = &event;
+                bio->bi_end_io = bi_read_complete;
+                if(bio_add_page(bio, page, PAGE_SIZE, 0) == PAGE_SIZE) {
+                        submit_bio(READ_SYNC, bio);
+                        wait_for_completion(&event);
+                        err = test_bit(BIO_UPTODATE, &bio->bi_flags) ? 0 : -EIO;
+                        bio_put(bio);
+                }
+        }
+
+        if(err)
+                SetPageError(page);
+        else
+                SetPageUptodate(page);
+        flush_dcache_page(page);
+        unlock_page(page);
+        return err;
+}
+
+
+/* write out the current BIO and wait for it to finish */
+static int blkmtd_write_out(struct bio *bio)
+{
+        struct completion event;
+        int err;
+
+        if(!bio->bi_vcnt) {
+                bio_put(bio);
+                return 0;
+        }
+
+        init_completion(&event);
+        bio->bi_private = &event;
+        bio->bi_end_io = bi_write_complete;
+        submit_bio(WRITE_SYNC, bio);
+        wait_for_completion(&event);
+        DEBUG(3, "submit_bio completed, bi_vcnt = %d\n", bio->bi_vcnt);
+        err = test_bit(BIO_UPTODATE, &bio->bi_flags) ? 0 : -EIO;
+        bio_put(bio);
+        return err;
+}
+
+
+/**
+ * blkmtd_add_page - add a page to the current BIO
+ * @bio: bio to add to (NULL to alloc initial bio)
+ * @blkdev: block device
+ * @page: page to add
+ * @pagecnt: pages left to add
+ *
+ * Adds a page to the current bio, allocating it if necessary. If it cannot be
+ * added, the current bio is written out and a new one is allocated. Returns
+ * the new bio to add or NULL on error
+ */
+static struct bio *blkmtd_add_page(struct bio *bio, struct block_device *blkdev,
+                                   struct page *page, int pagecnt)
+{
+
+ retry:
+        if(!bio) {
+                bio = bio_alloc(GFP_KERNEL, pagecnt);
+                if(!bio)
+                        return NULL;
+                bio->bi_sector = page->index << (PAGE_SHIFT-9);
+                bio->bi_bdev = blkdev;
+        }
+
+        if(bio_add_page(bio, page, PAGE_SIZE, 0) != PAGE_SIZE) {
+                blkmtd_write_out(bio);
+                bio = NULL;
+                goto retry;
+        }
+        return bio;
+}
+
+
+/**
+ * write_pages - write block of data to device via the page cache
+ * @dev: device to write to
+ * @buf: data source or NULL if erase (output is set to 0xff)
+ * @to: offset into output device
+ * @len: amount to data to write
+ * @retlen: amount of data written
+ *
+ * Grab pages from the page cache and fill them with the source data.
+ * Non page aligned start and end result in a readin of the page and
+ * part of the page being modified. Pages are added to the bio and then written
+ * out.
+ */
+static int write_pages(struct blkmtd_dev *dev, const u_char *buf, loff_t to,
+                    size_t len, size_t *retlen)
+{
+        int pagenr, offset;
+        size_t start_len = 0, end_len;
+        int pagecnt = 0;
+        int err = 0;
+        struct bio *bio = NULL;
+        size_t thislen = 0;
+
+        pagenr = to >> PAGE_SHIFT;
+        offset = to & ~PAGE_MASK;
+
+        DEBUG(2, "blkmtd: write_pages: buf = %p to = %ld len = %zd pagenr = %d offset = %d\n",
+              buf, (long)to, len, pagenr, offset);
+
+        /* see if we have to do a partial write at the start */
+        if(offset) {
+                start_len = ((offset + len) > PAGE_SIZE) ? PAGE_SIZE - offset : len;
+                len -= start_len;
+        }
+
+        /* calculate the length of the other two regions */
+        end_len = len & ~PAGE_MASK;
+        len -= end_len;
+
+        if(start_len)
+                pagecnt++;
+
+        if(len)
+                pagecnt += len >> PAGE_SHIFT;
+
+        if(end_len)
+                pagecnt++;
+
+        down(&dev->wrbuf_mutex);
+
+        DEBUG(3, "blkmtd: write: start_len = %zd len = %zd end_len = %zd pagecnt = %d\n",
+              start_len, len, end_len, pagecnt);
+
+        if(start_len) {
+                /* do partial start region */
+                struct page *page;
+
+                DEBUG(3, "blkmtd: write: doing partial start, page = %d len = %zd offset = %d\n",
+                      pagenr, start_len, offset);
+
+                BUG_ON(!buf);
+                page = read_cache_page(dev->blkdev->bd_inode->i_mapping, pagenr, (filler_t *)blkmtd_readpage, dev);
+                lock_page(page);
+                if(PageDirty(page)) {
+                        err("to = %lld start_len = %zd len = %zd end_len = %zd pagenr = %d\n",
+                            to, start_len, len, end_len, pagenr);
+                        BUG();
+                }
+                memcpy(page_address(page)+offset, buf, start_len);
+                SetPageDirty(page);
+                SetPageUptodate(page);
+                buf += start_len;
+                thislen = start_len;
+                bio = blkmtd_add_page(bio, dev->blkdev, page, pagecnt);
+                if(!bio) {
+                        err = -ENOMEM;
+                        err("bio_add_page failed\n");
+                        goto write_err;
+                }
+                pagecnt--;
+                pagenr++;
+        }
+
+        /* Now do the main loop to a page aligned, n page sized output */
+        if(len) {
+                int pagesc = len >> PAGE_SHIFT;
+                DEBUG(3, "blkmtd: write: whole pages start = %d, count = %d\n",
+                      pagenr, pagesc);
+                while(pagesc) {
+                        struct page *page;
+
+                        /* see if page is in the page cache */
+                        DEBUG(3, "blkmtd: write: grabbing page %d from page cache\n", pagenr);
+                        page = grab_cache_page(dev->blkdev->bd_inode->i_mapping, pagenr);
+                        if(PageDirty(page)) {
+                                BUG();
+                        }
+                        if(!page) {
+                                warn("write: cannot grab cache page %d", pagenr);
+                                err = -ENOMEM;
+                                goto write_err;
+                        }
+                        if(!buf) {
+                                memset(page_address(page), 0xff, PAGE_SIZE);
+                        } else {
+                                memcpy(page_address(page), buf, PAGE_SIZE);
+                                buf += PAGE_SIZE;
+                        }
+                        bio = blkmtd_add_page(bio, dev->blkdev, page, pagecnt);
+                        if(!bio) {
+                                err = -ENOMEM;
+                                err("bio_add_page failed\n");
+                                goto write_err;
+                        }
+                        pagenr++;
+                        pagecnt--;
+                        SetPageDirty(page);
+                        SetPageUptodate(page);
+                        pagesc--;
+                        thislen += PAGE_SIZE;
+                }
+        }
+
+        if(end_len) {
+                /* do the third region */
+                struct page *page;
+                DEBUG(3, "blkmtd: write: doing partial end, page = %d len = %zd\n",
+                      pagenr, end_len);
+                BUG_ON(!buf);
+                page = read_cache_page(dev->blkdev->bd_inode->i_mapping, pagenr, (filler_t *)blkmtd_readpage, dev);
+                lock_page(page);
+                if(PageDirty(page)) {
+                        err("to = %lld start_len = %zd len = %zd end_len = %zd pagenr = %d\n",
+                            to, start_len, len, end_len, pagenr);
+                        BUG();
+                }
+                memcpy(page_address(page), buf, end_len);
+                SetPageDirty(page);
+                SetPageUptodate(page);
+                DEBUG(3, "blkmtd: write: writing out partial end\n");
+                thislen += end_len;
+                bio = blkmtd_add_page(bio, dev->blkdev, page, pagecnt);
+                if(!bio) {
+                        err = -ENOMEM;
+                        err("bio_add_page failed\n");
+                        goto write_err;
+                }
+                pagenr++;
+        }
+
+        DEBUG(3, "blkmtd: write: got %d vectors to write\n", bio->bi_vcnt);
+ write_err:
+        if(bio)
+                blkmtd_write_out(bio);
+
+        DEBUG(2, "blkmtd: write: end, retlen = %zd, err = %d\n", *retlen, err);
+        up(&dev->wrbuf_mutex);
+
+        if(retlen)
+                *retlen = thislen;
+        return err;
+}
+
+
+/* erase a specified part of the device */
+static int blkmtd_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+        struct blkmtd_dev *dev = mtd->priv;
+        struct mtd_erase_region_info *einfo = mtd->eraseregions;
+        int numregions = mtd->numeraseregions;
+        size_t from;
+        u_long len;
+        int err = -EIO;
+        size_t retlen;
+
+        instr->state = MTD_ERASING;
+        from = instr->addr;
+        len = instr->len;
+
+        /* check erase region has valid start and length */
+        DEBUG(2, "blkmtd: erase: dev = `%s' from = 0x%zx len = 0x%lx\n",
+              mtd->name+9, from, len);
+        while(numregions) {
+                DEBUG(3, "blkmtd: checking erase region = 0x%08X size = 0x%X num = 0x%x\n",
+                      einfo->offset, einfo->erasesize, einfo->numblocks);
+                if(from >= einfo->offset
+                   && from < einfo->offset + (einfo->erasesize * einfo->numblocks)) {
+                        if(len == einfo->erasesize
+                           && ( (from - einfo->offset) % einfo->erasesize == 0))
+                                break;
+                }
+                numregions--;
+                einfo++;
+        }
+
+        if(!numregions) {
+                /* Not a valid erase block */
+                err("erase: invalid erase request 0x%lX @ 0x%08zX", len, from);
+                instr->state = MTD_ERASE_FAILED;
+                err = -EIO;
+        }
+
+        if(instr->state != MTD_ERASE_FAILED) {
+                /* do the erase */
+                DEBUG(3, "Doing erase from = %zd len = %ld\n", from, len);
+                err = write_pages(dev, NULL, from, len, &retlen);
+                if(err || retlen != len) {
+                        err("erase failed err = %d", err);
+                        instr->state = MTD_ERASE_FAILED;
+                } else {
+                        instr->state = MTD_ERASE_DONE;
+                }
+        }
+
+        DEBUG(3, "blkmtd: erase: checking callback\n");
+        mtd_erase_callback(instr);
+        DEBUG(2, "blkmtd: erase: finished (err = %d)\n", err);
+        return err;
+}
+
+
+/* read a range of the data via the page cache */
+static int blkmtd_read(struct mtd_info *mtd, loff_t from, size_t len,
+                       size_t *retlen, u_char *buf)
+{
+        struct blkmtd_dev *dev = mtd->priv;
+        int err = 0;
+        int offset;
+        int pagenr, pages;
+        size_t thislen = 0;
+
+        DEBUG(2, "blkmtd: read: dev = `%s' from = %lld len = %zd buf = %p\n",
+              mtd->name+9, from, len, buf);
+
+        if(from > mtd->size)
+                return -EINVAL;
+        if(from + len > mtd->size)
+                len = mtd->size - from;
+
+        pagenr = from >> PAGE_SHIFT;
+        offset = from - (pagenr << PAGE_SHIFT);
+
+        pages = (offset+len+PAGE_SIZE-1) >> PAGE_SHIFT;
+        DEBUG(3, "blkmtd: read: pagenr = %d offset = %d, pages = %d\n",
+              pagenr, offset, pages);
+
+        while(pages) {
+                struct page *page;
+                int cpylen;
+
+                DEBUG(3, "blkmtd: read: looking for page: %d\n", pagenr);
+                page = read_cache_page(dev->blkdev->bd_inode->i_mapping, pagenr, (filler_t *)blkmtd_readpage, dev);
+                if(IS_ERR(page)) {
+                        err = -EIO;
+                        goto readerr;
+                }
+
+                cpylen = (PAGE_SIZE > len) ? len : PAGE_SIZE;
+                if(offset+cpylen > PAGE_SIZE)
+                        cpylen = PAGE_SIZE-offset;
+
+                memcpy(buf + thislen, page_address(page) + offset, cpylen);
+                offset = 0;
+                len -= cpylen;
+                thislen += cpylen;
+                pagenr++;
+                pages--;
+                if(!PageDirty(page))
+                        page_cache_release(page);
+        }
+
+ readerr:
+        if(retlen)
+                *retlen = thislen;
+        DEBUG(2, "blkmtd: end read: retlen = %zd, err = %d\n", thislen, err);
+        return err;
+}
+
+
+/* write data to the underlying device */
+static int blkmtd_write(struct mtd_info *mtd, loff_t to, size_t len,
+                        size_t *retlen, const u_char *buf)
+{
+        struct blkmtd_dev *dev = mtd->priv;
+        int err;
+
+        if(!len)
+                return 0;
+
+        DEBUG(2, "blkmtd: write: dev = `%s' to = %lld len = %zd buf = %p\n",
+              mtd->name+9, to, len, buf);
+
+        if(to >= mtd->size) {
+                return -ENOSPC;
+        }
+
+        if(to + len > mtd->size) {
+                len = mtd->size - to;
+        }
+
+        err = write_pages(dev, buf, to, len, retlen);
+        if(err > 0)
+                err = 0;
+        DEBUG(2, "blkmtd: write: end, err = %d\n", err);
+        return err;
+}
+
+
+/* sync the device - wait until the write queue is empty */
+static void blkmtd_sync(struct mtd_info *mtd)
+{
+        /* Currently all writes are synchronous */
+}
+
+
+static void free_device(struct blkmtd_dev *dev)
+{
+        DEBUG(2, "blkmtd: free_device() dev = %p\n", dev);
+        if(dev) {
+                if(dev->mtd_info.eraseregions)
+                        kfree(dev->mtd_info.eraseregions);
+                if(dev->mtd_info.name)
+                        kfree(dev->mtd_info.name);
+
+                if(dev->blkdev) {
+                        invalidate_inode_pages(dev->blkdev->bd_inode->i_mapping);
+                        close_bdev_excl(dev->blkdev);
+                }
+                kfree(dev);
+        }
+}
+
+
+/* For a given size and initial erase size, calculate the number
+ * and size of each erase region. Goes round the loop twice,
+ * once to find out how many regions, then allocates space,
+ * then round the loop again to fill it in.
+ */
+static struct mtd_erase_region_info *calc_erase_regions(
+        size_t erase_size, size_t total_size, int *regions)
+{
+        struct mtd_erase_region_info *info = NULL;
+
+        DEBUG(2, "calc_erase_regions, es = %zd size = %zd regions = %d\n",
+              erase_size, total_size, *regions);
+        /* Make any user specified erasesize be a power of 2
+           and at least PAGE_SIZE */
+        if(erase_size) {
+                int es = erase_size;
+                erase_size = 1;
+                while(es != 1) {
+                        es >>= 1;
+                        erase_size <<= 1;
+                }
+                if(erase_size < PAGE_SIZE)
+                        erase_size = PAGE_SIZE;
+        } else {
+                erase_size = CONFIG_MTD_BLKDEV_ERASESIZE;
+        }
+
+        *regions = 0;
+
+        do {
+                int tot_size = total_size;
+                int er_size = erase_size;
+                int count = 0, offset = 0, regcnt = 0;
+
+                while(tot_size) {
+                        count = tot_size / er_size;
+                        if(count) {
+                                tot_size = tot_size % er_size;
+                                if(info) {
+                                        DEBUG(2, "adding to erase info off=%d er=%d cnt=%d\n",
+                                              offset, er_size, count);
+                                        (info+regcnt)->offset = offset;
+                                        (info+regcnt)->erasesize = er_size;
+                                        (info+regcnt)->numblocks = count;
+                                        (*regions)++;
+                                }
+                                regcnt++;
+                                offset += (count * er_size);
+                        }
+                        while(er_size > tot_size)
+                                er_size >>= 1;
+                }
+                if(info == NULL) {
+                        info = kmalloc(regcnt * sizeof(struct mtd_erase_region_info), GFP_KERNEL);
+                        if(!info)
+                                break;
+                }
+        } while(!(*regions));
+        DEBUG(2, "calc_erase_regions done, es = %zd size = %zd regions = %d\n",
+              erase_size, total_size, *regions);
+        return info;
+}
+
+
+extern dev_t __init name_to_dev_t(const char *line);
+
+static struct blkmtd_dev *add_device(char *devname, int readonly, int erase_size)
+{
+        struct block_device *bdev;
+        int mode;
+        struct blkmtd_dev *dev;
+
+        if(!devname)
+                return NULL;
+
+        /* Get a handle on the device */
+
+
+#ifdef MODULE
+        mode = (readonly) ? O_RDONLY : O_RDWR;
+        bdev = open_bdev_excl(devname, mode, NULL);
+#else
+        mode = (readonly) ? FMODE_READ : FMODE_WRITE;
+        bdev = open_by_devnum(name_to_dev_t(devname), mode);
+#endif
+        if(IS_ERR(bdev)) {
+                err("error: cannot open device %s", devname);
+                DEBUG(2, "blkmtd: opening bdev returned %ld\n", PTR_ERR(bdev));
+                return NULL;
+        }
+
+        DEBUG(1, "blkmtd: found a block device major = %d, minor = %d\n",
+              MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev));
+
+        if(MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
+                err("attempting to use an MTD device as a block device");
+                blkdev_put(bdev);
+                return NULL;
+        }
+
+        dev = kmalloc(sizeof(struct blkmtd_dev), GFP_KERNEL);
+        if(dev == NULL) {
+                blkdev_put(bdev);
+                return NULL;
+        }
+
+        memset(dev, 0, sizeof(struct blkmtd_dev));
+        dev->blkdev = bdev;
+        if(!readonly) {
+                init_MUTEX(&dev->wrbuf_mutex);
+        }
+
+        dev->mtd_info.size = dev->blkdev->bd_inode->i_size & PAGE_MASK;
+
+        /* Setup the MTD structure */
+        /* make the name contain the block device in */
+        dev->mtd_info.name = kmalloc(sizeof("blkmtd: ") + strlen(devname), GFP_KERNEL);
+        if(dev->mtd_info.name == NULL)
+                goto devinit_err;
+
+        sprintf(dev->mtd_info.name, "blkmtd: %s", devname);
+        dev->mtd_info.eraseregions = calc_erase_regions(erase_size, dev->mtd_info.size,
+                                                        &dev->mtd_info.numeraseregions);
+        if(dev->mtd_info.eraseregions == NULL)
+                goto devinit_err;
+
+        dev->mtd_info.erasesize = dev->mtd_info.eraseregions->erasesize;
+        DEBUG(1, "blkmtd: init: found %d erase regions\n",
+              dev->mtd_info.numeraseregions);
+
+        if(readonly) {
+                dev->mtd_info.type = MTD_ROM;
+                dev->mtd_info.flags = MTD_CAP_ROM;
+        } else {
+                dev->mtd_info.type = MTD_RAM;
+                dev->mtd_info.flags = MTD_CAP_RAM;
+                dev->mtd_info.erase = blkmtd_erase;
+                dev->mtd_info.write = blkmtd_write;
+                dev->mtd_info.writev = default_mtd_writev;
+                dev->mtd_info.sync = blkmtd_sync;
+        }
+        dev->mtd_info.read = blkmtd_read;
+        dev->mtd_info.readv = default_mtd_readv;
+        dev->mtd_info.priv = dev;
+        dev->mtd_info.owner = THIS_MODULE;
+
+        list_add(&dev->list, &blkmtd_device_list);
+        if (add_mtd_device(&dev->mtd_info)) {
+                /* Device didnt get added, so free the entry */
+                list_del(&dev->list);
+                goto devinit_err;
+        } else {
+                info("mtd%d: [%s] erase_size = %dKiB %s",
+                     dev->mtd_info.index, dev->mtd_info.name + strlen("blkmtd: "),
+                     dev->mtd_info.erasesize >> 10,
+                     readonly ? "(read-only)" : "");
+        }
+        
+        return dev;
+
+ devinit_err:
+        free_device(dev);
+        return NULL;
+}
+
+
+/* Cleanup and exit - sync the device and kill of the kernel thread */
+static void __devexit cleanup_blkmtd(void)
+{
+        struct list_head *temp1, *temp2;
+
+        /* Remove the MTD devices */
+        list_for_each_safe(temp1, temp2, &blkmtd_device_list) {
+                struct blkmtd_dev *dev = list_entry(temp1, struct blkmtd_dev,
+                                                    list);
+                blkmtd_sync(&dev->mtd_info);
+                del_mtd_device(&dev->mtd_info);
+                info("mtd%d: [%s] removed", dev->mtd_info.index,
+                     dev->mtd_info.name + strlen("blkmtd: "));
+                list_del(&dev->list);
+                free_device(dev);
+        }
+}
+
+#ifndef MODULE
+
+/* Handle kernel boot params */
+
+
+static int __init param_blkmtd_device(char *str)
+{
+        int i;
+
+        for(i = 0; i < MAX_DEVICES; i++) {
+                device[i] = str;
+                DEBUG(2, "blkmtd: device setup: %d = %s\n", i, device[i]);
+                strsep(&str, ",");
+        }
+        return 1;
+}
+
+
+static int __init param_blkmtd_erasesz(char *str)
+{
+        int i;
+        for(i = 0; i < MAX_DEVICES; i++) {
+                char *val = strsep(&str, ",");
+                if(val)
+                        erasesz[i] = simple_strtoul(val, NULL, 0);
+                DEBUG(2, "blkmtd: erasesz setup: %d = %d\n", i, erasesz[i]);
+        }
+
+        return 1;
+}
+
+
+static int __init param_blkmtd_ro(char *str)
+{
+        int i;
+        for(i = 0; i < MAX_DEVICES; i++) {
+                char *val = strsep(&str, ",");
+                if(val)
+                        ro[i] = simple_strtoul(val, NULL, 0);
+                DEBUG(2, "blkmtd: ro setup: %d = %d\n", i, ro[i]);
+        }
+
+        return 1;
+}
+
+
+static int __init param_blkmtd_sync(char *str)
+{
+        if(str[0] == '1')
+                sync = 1;
+        return 1;
+}
+
+__setup("blkmtd_device=", param_blkmtd_device);
+__setup("blkmtd_erasesz=", param_blkmtd_erasesz);
+__setup("blkmtd_ro=", param_blkmtd_ro);
+__setup("blkmtd_sync=", param_blkmtd_sync);
+
+#endif
+
+
+/* Startup */
+static int __init init_blkmtd(void)
+{
+        int i;
+
+        info("version " VERSION);
+        /* Check args - device[0] is the bare minimum*/
+        if(!device[0]) {
+                err("error: missing `device' name\n");
+                return -EINVAL;
+        }
+
+        for(i = 0; i < MAX_DEVICES; i++)
+                add_device(device[i], ro[i], erasesz[i] << 10);
+
+        if(list_empty(&blkmtd_device_list))
+                return -EINVAL;
+
+        return 0;
+}
+
+module_init(init_blkmtd);
+module_exit(cleanup_blkmtd);