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Subject[PATCH] mtd/nftlmount: use memchr_inv
Date
Use memchr_inv to check if the data contains all 0xFF bytes.  It is
faster than looping for each byte.
This also removes memcmpb which is no longer used.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: linux-mtd@lists.infradead.org
---
drivers/mtd/nftlmount.c | 20 +++++---------------
1 files changed, 5 insertions(+), 15 deletions(-)
diff --git a/drivers/mtd/nftlmount.c b/drivers/mtd/nftlmount.c
index 51b9d6a..a96bdb4 100644
--- a/drivers/mtd/nftlmount.c
+++ b/drivers/mtd/nftlmount.c
@@ -255,16 +255,6 @@ The new DiskOnChip driver already scanned the bad block table. Just query it.
return boot_record_count?0:-1;
}

-static int memcmpb(void *a, int c, int n)
-{
- int i;
- for (i = 0; i < n; i++) {
- if (c != ((unsigned char *)a)[i])
- return 1;
- }
- return 0;
-}
-
/* check_free_sector: check if a free sector is actually FREE, i.e. All 0xff in data and oob area */
static int check_free_sectors(struct NFTLrecord *nftl, unsigned int address, int len,
int check_oob)
@@ -277,14 +267,14 @@ static int check_free_sectors(struct NFTLrecord *nftl, unsigned int address, int
for (i = 0; i < len; i += SECTORSIZE) {
if (mtd_read(mtd, address, SECTORSIZE, &retlen, buf))
return -1;
- if (memcmpb(buf, 0xff, SECTORSIZE) != 0)
+ if (memchr_inv(buf, 0xff, SECTORSIZE))
return -1;

if (check_oob) {
if(nftl_read_oob(mtd, address, mtd->oobsize,
&retlen, &buf[SECTORSIZE]) < 0)
return -1;
- if (memcmpb(buf + SECTORSIZE, 0xff, mtd->oobsize) != 0)
+ if (memchr_inv(buf + SECTORSIZE, 0xff, mtd->oobsize))
return -1;
}
address += SECTORSIZE;
@@ -392,7 +382,7 @@ static void check_sectors_in_chain(struct NFTLrecord *nftl, unsigned int first_b
case SECTOR_FREE:
/* verify that the sector is really free. If not, mark
as ignore */
- if (memcmpb(&bci, 0xff, 8) != 0 ||
+ if (memchr_inv(&bci, 0xff, 8) ||
check_free_sectors(nftl, block * nftl->EraseSize + i * SECTORSIZE,
SECTORSIZE, 0) != 0) {
printk("Incorrect free sector %d in block %d: "
@@ -529,10 +519,10 @@ static int check_and_mark_free_block(struct NFTLrecord *nftl, int block)
return -1;
if (i == SECTORSIZE) {
/* skip erase mark */
- if (memcmpb(buf, 0xff, 8))
+ if (memchr_inv(buf, 0xff, 8))
return -1;
} else {
- if (memcmpb(buf, 0xff, 16))
+ if (memchr_inv(buf, 0xff, 16))
return -1;
}
}
--
1.7.4.4


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