diff options
Diffstat (limited to 'linux-2.4.x/drivers/mtd/devices/blkmtd-24.c')
| -rw-r--r-- | linux-2.4.x/drivers/mtd/devices/blkmtd-24.c | 1056 |
1 files changed, 1056 insertions, 0 deletions
diff --git a/linux-2.4.x/drivers/mtd/devices/blkmtd-24.c b/linux-2.4.x/drivers/mtd/devices/blkmtd-24.c new file mode 100644 index 0000000..1672fc5 --- /dev/null +++ b/linux-2.4.x/drivers/mtd/devices/blkmtd-24.c @@ -0,0 +1,1056 @@ +/* + * $Id: blkmtd-24.c,v 1.24 2005/11/07 11:14:24 gleixner 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 kiobuf. + * When the kiobuf becomes full or the next extry is to an earlier + * block in the kiobuf then it is flushed to disk. This allows + * writes to remained ordered and gives a small and simple outgoing + * write cache. + * + * 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/iobuf.h> +#include <linux/slab.h> +#include <linux/pagemap.h> +#include <linux/list.h> +#include <linux/mtd/mtd.h> + +#ifdef CONFIG_MTD_DEBUG +#ifdef CONFIG_PROC_FS +# include <linux/proc_fs.h> +# define BLKMTD_PROC_DEBUG + static struct proc_dir_entry *blkmtd_proc; +#endif +#endif + + +#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 KiB, always make it a multiple of PAGE_SIZE */ +#define CONFIG_MTD_BLKDEV_ERASESIZE (128 << 10) /* 128KiB */ +#define VERSION "1.10" + +/* Info for the block device */ +struct blkmtd_dev { + struct list_head list; + struct block_device *binding; + struct mtd_info mtd_info; + struct kiobuf *rd_buf, *wr_buf; + long iobuf_locks; + 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 */ +char *device[MAX_DEVICES]; /* the block device to use */ +int erasesz[MAX_DEVICES]; /* optional default erase size */ +int ro[MAX_DEVICES]; /* optional read only flag */ +int sync; + + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Simon Evans <spse@secret.org.uk>"); +MODULE_DESCRIPTION("Emulate an MTD using a block device"); +MODULE_PARM(device, "1-4s"); +MODULE_PARM_DESC(device, "block device to use"); +MODULE_PARM(erasesz, "1-4i"); +MODULE_PARM_DESC(erasesz, "optional erase size to use in KiB. eg 4=4KiB."); +MODULE_PARM(ro, "1-4i"); +MODULE_PARM_DESC(ro, "1=Read only, writes and erases cause errors"); +MODULE_PARM(sync, "i"); +MODULE_PARM_DESC(sync, "1=Synchronous writes"); + + +/** + * read_pages - read in pages via the page cache + * @dev: device to read from + * @pagenrs: list of page numbers wanted + * @pagelst: storage for struce page * pointers + * @pages: count of pages wanted + * + * Read pages, getting them from the page cache if available + * else reading them in from disk if not. pagelst must be preallocated + * to hold the page count. + */ +static int read_pages(struct blkmtd_dev *dev, int pagenrs[], struct page **pagelst, int pages) +{ + kdev_t kdev; + struct page *page; + int cnt = 0; + struct kiobuf *iobuf; + int err = 0; + + if(!dev) { + err("read_pages: PANIC dev == NULL"); + return -EIO; + } + kdev = to_kdev_t(dev->binding->bd_dev); + + DEBUG(2, "read_pages: reading %d pages\n", pages); + if(test_and_set_bit(0, &dev->iobuf_locks)) { + err = alloc_kiovec(1, &iobuf); + if (err) { + crit("cant allocate kiobuf"); + return -ENOMEM; + } +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,4,4) + iobuf->blocks = kmalloc(KIO_MAX_SECTORS * sizeof(unsigned long), GFP_KERNEL); + if(iobuf->blocks == NULL) { + crit("cant allocate iobuf blocks"); + free_kiovec(1, &iobuf); + return -ENOMEM; + } +#endif + } else { + iobuf = dev->rd_buf; + } + + iobuf->nr_pages = 0; + iobuf->length = 0; + iobuf->offset = 0; + iobuf->locked = 1; + + for(cnt = 0; cnt < pages; cnt++) { + page = grab_cache_page(dev->binding->bd_inode->i_mapping, pagenrs[cnt]); + pagelst[cnt] = page; + if(!Page_Uptodate(page)) { + iobuf->blocks[iobuf->nr_pages] = pagenrs[cnt]; + iobuf->maplist[iobuf->nr_pages++] = page; + } + } + + if(iobuf->nr_pages) { + iobuf->length = iobuf->nr_pages << PAGE_SHIFT; + err = brw_kiovec(READ, 1, &iobuf, kdev, iobuf->blocks, PAGE_SIZE); + DEBUG(3, "blkmtd: read_pages: finished, err = %d\n", err); + if(err < 0) { + while(pages--) { + ClearPageUptodate(pagelst[pages]); + unlock_page(pagelst[pages]); + page_cache_release(pagelst[pages]); + } + } else { + while(iobuf->nr_pages--) { + SetPageUptodate(iobuf->maplist[iobuf->nr_pages]); + } + err = 0; + } + } + + + if(iobuf != dev->rd_buf) { +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,4,4) + kfree(iobuf->blocks); +#endif + free_kiovec(1, &iobuf); + } else { + clear_bit(0, &dev->iobuf_locks); + } + DEBUG(2, "read_pages: done, err = %d\n", err); + return err; +} + + +/** + * commit_pages - commit pages in the writeout kiobuf to disk + * @dev: device to write to + * + * If the current dev has pages in the dev->wr_buf kiobuf, + * they are written to disk using brw_kiovec() + */ +static int commit_pages(struct blkmtd_dev *dev) +{ + struct kiobuf *iobuf = dev->wr_buf; + kdev_t kdev = to_kdev_t(dev->binding->bd_dev); + int err = 0; + + iobuf->length = iobuf->nr_pages << PAGE_SHIFT; + iobuf->locked = 1; + if(iobuf->length) { + int i; + DEBUG(2, "blkmtd: commit_pages: nrpages = %d\n", iobuf->nr_pages); + /* Check all the pages are dirty and lock them */ + for(i = 0; i < iobuf->nr_pages; i++) { + struct page *page = iobuf->maplist[i]; + BUG_ON(!PageDirty(page)); + lock_page(page); + } + err = brw_kiovec(WRITE, 1, &iobuf, kdev, iobuf->blocks, PAGE_SIZE); + DEBUG(3, "commit_write: committed %d pages err = %d\n", iobuf->nr_pages, err); + while(iobuf->nr_pages) { + struct page *page = iobuf->maplist[--iobuf->nr_pages]; + ClearPageDirty(page); + SetPageUptodate(page); + unlock_page(page); + page_cache_release(page); + } + } + + DEBUG(2, "blkmtd: sync: end, err = %d\n", err); + iobuf->offset = 0; + iobuf->nr_pages = 0; + iobuf->length = 0; + return err; +} + + +/** + * 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 wr_buf kiobuf + * until this becomes full or the next page written to has a lower pagenr + * then the current max pagenr in the kiobuf. + */ +static int write_pages(struct blkmtd_dev *dev, const u_char *buf, loff_t to, + size_t len, int *retlen) +{ + int pagenr, offset; + size_t start_len = 0, end_len; + int pagecnt = 0; + struct kiobuf *iobuf = dev->wr_buf; + int err = 0; + struct page *pagelst[2]; + int pagenrs[2]; + int readpages = 0; + int ignorepage = -1; + + 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); + + *retlen = 0; + /* 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) { + pagenrs[0] = pagenr; + readpages++; + pagecnt++; + } + if(len) + pagecnt += len >> PAGE_SHIFT; + if(end_len) { + pagenrs[readpages] = pagenr + pagecnt; + readpages++; + pagecnt++; + } + + DEBUG(3, "blkmtd: write: start_len = %zd len = %zd end_len = %zd pagecnt = %d\n", + start_len, len, end_len, pagecnt); + + down(&dev->wrbuf_mutex); + + if(iobuf->nr_pages && ((pagenr <= iobuf->blocks[iobuf->nr_pages-1]) + || (iobuf->nr_pages + pagecnt) >= KIO_STATIC_PAGES)) { + + if((pagenr == iobuf->blocks[iobuf->nr_pages-1]) + && ((iobuf->nr_pages + pagecnt) < KIO_STATIC_PAGES)) { + iobuf->nr_pages--; + ignorepage = pagenr; + } else { + DEBUG(3, "blkmtd: doing writeout pagenr = %d max_pagenr = %ld pagecnt = %d idx = %d\n", + pagenr, iobuf->blocks[iobuf->nr_pages-1], + pagecnt, iobuf->nr_pages); + commit_pages(dev); + } + } + + if(readpages) { + err = read_pages(dev, pagenrs, pagelst, readpages); + if(err < 0) + goto readin_err; + } + + 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); + page = pagelst[0]; + BUG_ON(!buf); + if(PageDirty(page) && pagenr != ignorepage) { + err("to = %lld start_len = %zd len = %zd end_len = %zd pagenr = %d ignorepage = %d\n", + to, start_len, len, end_len, pagenr, ignorepage); + BUG(); + } + memcpy(page_address(page)+offset, buf, start_len); + SetPageDirty(page); + SetPageUptodate(page); + unlock_page(page); + buf += start_len; + *retlen = start_len; + err = 0; + iobuf->blocks[iobuf->nr_pages] = pagenr++; + iobuf->maplist[iobuf->nr_pages] = page; + iobuf->nr_pages++; + } + + /* 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->binding->bd_inode->i_mapping, pagenr); + if(PageDirty(page) && pagenr != ignorepage) { + BUG(); + } + if(!page) { + warn("write: cant 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; + } + iobuf->blocks[iobuf->nr_pages] = pagenr++; + iobuf->maplist[iobuf->nr_pages] = page; + iobuf->nr_pages++; + SetPageDirty(page); + SetPageUptodate(page); + unlock_page(page); + pagesc--; + *retlen += 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); + page = pagelst[readpages-1]; + BUG_ON(!buf); + if(PageDirty(page) && pagenr != ignorepage) { + err("to = %lld start_len = %zd len = %zd end_len = %zd pagenr = %d ignorepage = %d\n", + to, start_len, len, end_len, pagenr, ignorepage); + BUG(); + } + memcpy(page_address(page), buf, end_len); + SetPageDirty(page); + SetPageUptodate(page); + unlock_page(page); + DEBUG(3, "blkmtd: write: writing out partial end\n"); + *retlen += end_len; + err = 0; + iobuf->blocks[iobuf->nr_pages] = pagenr; + iobuf->maplist[iobuf->nr_pages] = page; + iobuf->nr_pages++; + } + + DEBUG(2, "blkmtd: write: end, retlen = %zd, err = %d\n", *retlen, err); + + if(sync) { +write_err: + commit_pages(dev); + } + +readin_err: + up(&dev->wrbuf_mutex); + 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; + + /* check readonly */ + if(!dev->wr_buf) { + err("error: mtd%d trying to erase readonly device %s", + mtd->index, mtd->name); + instr->state = MTD_ERASE_FAILED; + goto erase_callback; + } + + 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", + bdevname(dev->binding->bd_dev), 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 < 0) { + err("erase failed err = %d", err); + instr->state = MTD_ERASE_FAILED; + } else { + instr->state = MTD_ERASE_DONE; + err = 0; + } + } + + DEBUG(3, "blkmtd: erase: checking callback\n"); + erase_callback: + 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; + struct page **pagelst; + int *pagenrs; + int i; + + *retlen = 0; + + DEBUG(2, "blkmtd: read: dev = `%s' from = %lld len = %zd buf = %p\n", + bdevname(dev->binding->bd_dev), from, len, buf); + + 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); + + pagelst = kmalloc(sizeof(struct page *) * pages, GFP_KERNEL); + if(!pagelst) + return -ENOMEM; + pagenrs = kmalloc(sizeof(int) * pages, GFP_KERNEL); + if(!pagenrs) { + kfree(pagelst); + return -ENOMEM; + } + for(i = 0; i < pages; i++) + pagenrs[i] = pagenr+i; + + err = read_pages(dev, pagenrs, pagelst, pages); + if(err) + goto readerr; + + pagenr = 0; + while(pages) { + struct page *page; + int cpylen; + + DEBUG(3, "blkmtd: read: looking for page: %d\n", pagenr); + page = pagelst[pagenr]; + + cpylen = (PAGE_SIZE > len) ? len : PAGE_SIZE; + if(offset+cpylen > PAGE_SIZE) + cpylen = PAGE_SIZE-offset; + + memcpy(buf + *retlen, page_address(page) + offset, cpylen); + offset = 0; + len -= cpylen; + *retlen += cpylen; + pagenr++; + pages--; + unlock_page(page); + if(!PageDirty(page)) + page_cache_release(page); + } + + readerr: + kfree(pagelst); + kfree(pagenrs); + DEBUG(2, "blkmtd: end read: retlen = %zd, err = %d\n", *retlen, 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; + + *retlen = 0; + if(!len) + return 0; + + DEBUG(2, "blkmtd: write: dev = `%s' to = %lld len = %zd buf = %p\n", + bdevname(dev->binding->bd_dev), to, len, buf); + + /* handle readonly and out of range numbers */ + + if(!dev->wr_buf) { + err("error: trying to write to a readonly device %s", mtd->name); + return -EROFS; + } + + 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) + *retlen = 0; + else + 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) +{ + struct blkmtd_dev *dev = mtd->priv; + struct kiobuf *iobuf = dev->wr_buf; + + DEBUG(2, "blkmtd: sync: called\n"); + if(iobuf == NULL) + return; + + DEBUG(3, "blkmtd: kiovec: length = %d nr_pages = %d\n", + iobuf->length, iobuf->nr_pages); + down(&dev->wrbuf_mutex); + if(iobuf->nr_pages) + commit_pages(dev); + up(&dev->wrbuf_mutex); +} + + +#ifdef BLKMTD_PROC_DEBUG +/* procfs stuff */ +static int blkmtd_proc_read(char *page, char **start, off_t off, + int count, int *eof, void *data) +{ + int len; + struct list_head *temp1, *temp2; + + MOD_INC_USE_COUNT; + + /* Count the size of the page lists */ + + len = sprintf(page, "dev\twr_idx\tmax_idx\tnrpages\tclean\tdirty\tlocked\tlru\n"); + list_for_each_safe(temp1, temp2, &blkmtd_device_list) { + struct blkmtd_dev *dev = list_entry(temp1, struct blkmtd_dev, + list); + struct list_head *temp; + struct page *pagei; + + int clean = 0, dirty = 0, locked = 0, lru = 0; + /* Count the size of the page lists */ + list_for_each(temp, &dev->binding->bd_inode->i_mapping->clean_pages) { + pagei = list_entry(temp, struct page, list); + clean++; + if(PageLocked(pagei)) + locked++; + if(PageDirty(pagei)) + dirty++; + if(PageLRU(pagei)) + lru++; + } + list_for_each(temp, &dev->binding->bd_inode->i_mapping->dirty_pages) { + pagei = list_entry(temp, struct page, list); + if(PageLocked(pagei)) + locked++; + if(PageDirty(pagei)) + dirty++; + if(PageLRU(pagei)) + lru++; + } + list_for_each(temp, &dev->binding->bd_inode->i_mapping->locked_pages) { + pagei = list_entry(temp, struct page, list); + if(PageLocked(pagei)) + locked++; + if(PageDirty(pagei)) + dirty++; + if(PageLRU(pagei)) + lru++; + } + + len += sprintf(page+len, "mtd%d:\t%ld\t%d\t%ld\t%d\t%d\t%d\t%d\n", + dev->mtd_info.index, + (dev->wr_buf && dev->wr_buf->nr_pages) ? + dev->wr_buf->blocks[dev->wr_buf->nr_pages-1] : 0, + (dev->wr_buf) ? dev->wr_buf->nr_pages : 0, + dev->binding->bd_inode->i_mapping->nrpages, + clean, dirty, locked, lru); + } + + if(len <= count) + *eof = 1; + + MOD_DEC_USE_COUNT; + return len; +} +#endif + + +static void free_device(struct blkmtd_dev *dev) +{ + DEBUG(2, "blkmtd: free_device() dev = %p\n", dev); + if(dev) { + del_mtd_device(&dev->mtd_info); + info("mtd%d: [%s] removed", dev->mtd_info.index, + dev->mtd_info.name + strlen("blkmtd: ")); + if(dev->mtd_info.eraseregions) + kfree(dev->mtd_info.eraseregions); + if(dev->mtd_info.name) + kfree(dev->mtd_info.name); + + if(dev->rd_buf) { + dev->rd_buf->locked = 0; +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,4,4) + if(dev->rd_buf->blocks) + kfree(dev->rd_buf->blocks); +#endif + free_kiovec(1, &dev->rd_buf); + } + if(dev->wr_buf) { + dev->wr_buf->locked = 0; +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,4,4) + if(dev->wr_buf->blocks) + kfree(dev->rw_buf->blocks); +#endif + free_kiovec(1, &dev->wr_buf); + } + + if(dev->binding) { + kdev_t kdev = to_kdev_t(dev->binding->bd_dev); + invalidate_inode_pages(dev->binding->bd_inode); + set_blocksize(kdev, 1 << 10); + blkdev_put(dev->binding, BDEV_RAW); + } + 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 kdev_t name_to_kdev_t(char *line) __init; + + +static struct blkmtd_dev *add_device(char *devname, int readonly, int erase_size) +{ + int maj, min; + kdev_t kdev; + int mode; + struct blkmtd_dev *dev; + +#ifdef MODULE + struct file *file = NULL; + struct inode *inode; +#endif + + if(!devname) + return NULL; + + /* Get a handle on the device */ + mode = (readonly) ? O_RDONLY : O_RDWR; + +#ifdef MODULE + + file = filp_open(devname, mode, 0); + if(IS_ERR(file)) { + err("error: cant open device %s", devname); + DEBUG(2, "blkmtd: filp_open returned %ld\n", PTR_ERR(file)); + return NULL; + } + + /* determine is this is a block device and + * if so get its major and minor numbers + */ + inode = file->f_dentry->d_inode; + if(!S_ISBLK(inode->i_mode)) { + err("%s not a block device", devname); + filp_close(file, NULL); + return NULL; + } + kdev = inode->i_rdev; + filp_close(file, NULL); +#else + kdev = name_to_kdev_t(devname); +#endif /* MODULE */ + + if(!kdev) { + err("bad block device: `%s'", devname); + return NULL; + } + + maj = MAJOR(kdev); + min = MINOR(kdev); + DEBUG(1, "blkmtd: found a block device major = %d, minor = %d\n", + maj, min); + + if(maj == MTD_BLOCK_MAJOR) { + err("attempting to use an MTD device as a block device"); + return NULL; + } + + DEBUG(1, "blkmtd: devname = %s\n", bdevname(kdev)); + + dev = kmalloc(sizeof(struct blkmtd_dev), GFP_KERNEL); + if(dev == NULL) + return NULL; + + memset(dev, 0, sizeof(struct blkmtd_dev)); + if(alloc_kiovec(1, &dev->rd_buf)) { + err("cant allocate read iobuf"); + goto devinit_err; + } +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,4,4) + dev->rd_buf->blocks = kmalloc(KIO_MAX_SECTORS * sizeof(unsigned long), GFP_KERNEL); + if(dev->rd_buf->blocks == NULL) { + crit("cant allocate rd_buf blocks"); + goto devinit_err; + } +#endif + + if(!readonly) { + if(alloc_kiovec(1, &dev->wr_buf)) { + err("cant allocate kiobuf - readonly enabled"); + +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,4,4) + } else { + dev->wr_buf->blocks = kmalloc(KIO_MAX_SECTORS * sizeof(unsigned long), GFP_KERNEL); + if(dev->wr_buf->blocks == NULL) { + crit("cant allocate wr_buf blocks - readonly enabled"); + free_kiovec(1, &iobuf); + } +#endif + } + if(dev->wr_buf) + init_MUTEX(&dev->wrbuf_mutex); + } + + /* get the block device */ + dev->binding = bdget(kdev_t_to_nr(MKDEV(maj, min))); + if(blkdev_get(dev->binding, mode, 0, BDEV_RAW)) + goto devinit_err; + + if(set_blocksize(kdev, PAGE_SIZE)) { + err("cant set block size to PAGE_SIZE on %s", bdevname(kdev)); + goto devinit_err; + } + + dev->mtd_info.size = dev->binding->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.read = blkmtd_read; + dev->mtd_info.write = blkmtd_write; + dev->mtd_info.sync = blkmtd_sync; + dev->mtd_info.point = 0; + dev->mtd_info.unpoint = 0; + 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); + free_device(dev); + return NULL; + } else { + info("mtd%d: [%s] erase_size = %dKiB %s", + dev->mtd_info.index, dev->mtd_info.name + strlen("blkmtd: "), + dev->mtd_info.erasesize >> 10, + (dev->wr_buf) ? "" : "(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; +#ifdef BLKMTD_PROC_DEBUG + if(blkmtd_proc) { + remove_proc_entry("blkmtd_debug", NULL); + } +#endif + + /* 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); + 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; + + /* 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)) + goto init_err; + + info("version " VERSION); + +#ifdef BLKMTD_PROC_DEBUG + /* create proc entry */ + DEBUG(2, "Creating /proc/blkmtd_debug\n"); + blkmtd_proc = create_proc_read_entry("blkmtd_debug", 0444, + NULL, blkmtd_proc_read, NULL); + if(blkmtd_proc == NULL) { + err("Cant create /proc/blkmtd_debug"); + } else { + blkmtd_proc->owner = THIS_MODULE; + } +#endif + + if(!list_empty(&blkmtd_device_list)) + /* Everything is ok if we got here */ + return 0; + + init_err: + return -EINVAL; +} + +module_init(init_blkmtd); +module_exit(cleanup_blkmtd); |