diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/mtd/nand/nand_util.c | 68 |
1 files changed, 60 insertions, 8 deletions
diff --git a/drivers/mtd/nand/nand_util.c b/drivers/mtd/nand/nand_util.c index ff2d348..4727f9c 100644 --- a/drivers/mtd/nand/nand_util.c +++ b/drivers/mtd/nand/nand_util.c @@ -416,11 +416,13 @@ int nand_unlock(struct mtd_info *mtd, loff_t start, size_t length, * @param nand NAND device * @param offset offset in flash * @param length image length + * @param used length of flash needed for the requested length * @return 0 if the image fits and there are no bad blocks * 1 if the image fits, but there are bad blocks * -1 if the image does not fit */ -static int check_skip_len(nand_info_t *nand, loff_t offset, size_t length) +static int check_skip_len(nand_info_t *nand, loff_t offset, size_t length, + size_t *used) { size_t len_excl_bad = 0; int ret = 0; @@ -442,8 +444,13 @@ static int check_skip_len(nand_info_t *nand, loff_t offset, size_t length) ret = 1; offset += block_len; + *used += block_len; } + /* If the length is not a multiple of block_len, adjust. */ + if (len_excl_bad > length) + *used -= (len_excl_bad - length); + return ret; } @@ -476,23 +483,36 @@ static size_t drop_ffs(const nand_info_t *nand, const u_char *buf, * Write image to NAND flash. * Blocks that are marked bad are skipped and the is written to the next * block instead as long as the image is short enough to fit even after - * skipping the bad blocks. + * skipping the bad blocks. Due to bad blocks we may not be able to + * perform the requested write. In the case where the write would + * extend beyond the end of the NAND device, both length and actual (if + * not NULL) are set to 0. In the case where the write would extend + * beyond the limit we are passed, length is set to 0 and actual is set + * to the required length. * * @param nand NAND device * @param offset offset in flash * @param length buffer length + * @param actual set to size required to write length worth of + * buffer or 0 on error, if not NULL + * @param lim maximum size that actual may be in order to not + * exceed the buffer * @param buffer buffer to read from * @param flags flags modifying the behaviour of the write to NAND * @return 0 in case of success */ int nand_write_skip_bad(nand_info_t *nand, loff_t offset, size_t *length, - u_char *buffer, int flags) + size_t *actual, loff_t lim, u_char *buffer, int flags) { int rval = 0, blocksize; size_t left_to_write = *length; + size_t used_for_write = 0; u_char *p_buffer = buffer; int need_skip; + if (actual) + *actual = 0; + #ifdef CONFIG_CMD_NAND_YAFFS if (flags & WITH_YAFFS_OOB) { if (flags & ~WITH_YAFFS_OOB) @@ -529,13 +549,23 @@ int nand_write_skip_bad(nand_info_t *nand, loff_t offset, size_t *length, return -EINVAL; } - need_skip = check_skip_len(nand, offset, *length); + need_skip = check_skip_len(nand, offset, *length, &used_for_write); + + if (actual) + *actual = used_for_write; + if (need_skip < 0) { printf("Attempt to write outside the flash area\n"); *length = 0; return -EINVAL; } + if (used_for_write > lim) { + puts("Size of write exceeds partition or device limit\n"); + *length = 0; + return -EFBIG; + } + if (!need_skip && !(flags & WITH_DROP_FFS)) { rval = nand_write(nand, offset, length, buffer); if (rval == 0) @@ -626,36 +656,58 @@ int nand_write_skip_bad(nand_info_t *nand, loff_t offset, size_t *length, * * Read image from NAND flash. * Blocks that are marked bad are skipped and the next block is read - * instead as long as the image is short enough to fit even after skipping the - * bad blocks. + * instead as long as the image is short enough to fit even after + * skipping the bad blocks. Due to bad blocks we may not be able to + * perform the requested read. In the case where the read would extend + * beyond the end of the NAND device, both length and actual (if not + * NULL) are set to 0. In the case where the read would extend beyond + * the limit we are passed, length is set to 0 and actual is set to the + * required length. * * @param nand NAND device * @param offset offset in flash * @param length buffer length, on return holds number of read bytes + * @param actual set to size required to read length worth of buffer or 0 + * on error, if not NULL + * @param lim maximum size that actual may be in order to not exceed the + * buffer * @param buffer buffer to write to * @return 0 in case of success */ int nand_read_skip_bad(nand_info_t *nand, loff_t offset, size_t *length, - u_char *buffer) + size_t *actual, loff_t lim, u_char *buffer) { int rval; size_t left_to_read = *length; + size_t used_for_read = 0; u_char *p_buffer = buffer; int need_skip; if ((offset & (nand->writesize - 1)) != 0) { printf("Attempt to read non page-aligned data\n"); *length = 0; + if (actual) + *actual = 0; return -EINVAL; } - need_skip = check_skip_len(nand, offset, *length); + need_skip = check_skip_len(nand, offset, *length, &used_for_read); + + if (actual) + *actual = used_for_read; + if (need_skip < 0) { printf("Attempt to read outside the flash area\n"); *length = 0; return -EINVAL; } + if (used_for_read > lim) { + puts("Size of read exceeds partition or device limit\n"); + *length = 0; + return -EFBIG; + } + if (!need_skip) { rval = nand_read(nand, offset, length, buffer); if (!rval || rval == -EUCLEAN) |