[PATCH v4 11/13] mtd: ssfdc: Replace open-coded parity calculation with parity_odd()

Kuan-Wei Chiu
2025-05-15T09:20:19Z

Refactor parity calculations to use the standard parity_odd() helper.
This change eliminates redundant implementations.

Co-developed-by: Yu-Chun Lin <eleanor15x@gmail.com>
Signed-off-by: Yu-Chun Lin <eleanor15x@gmail.com>
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
---
drivers/mtd/ssfdc.c | 20 ++++----------------
1 file changed, 4 insertions(+), 16 deletions(-)

diff --git a/drivers/mtd/ssfdc.c b/drivers/mtd/ssfdc.c
index 46c01fa2ec46..0db4776424d0 100644
--- a/drivers/mtd/ssfdc.c
+++ b/drivers/mtd/ssfdc.c
@@ -7,6 +7,7 @@
* Based on NTFL and MTDBLOCK_RO drivers
*/

+#include <linux/bitops.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
@@ -178,24 +179,11 @@ static int read_raw_oob(struct mtd_info *mtd, loff_t offs, uint8_t *buf)
return 0;
}

-/* Parity calculator on a word of n bit size */
-static int get_parity(int number, int size)
-{
- int k;
- int parity;
-
- parity = 1;
- for (k = 0; k < size; k++) {
- parity += (number >> k);
- parity &= 1;
- }
- return parity;
-}
-
/* Read and validate the logical block address field stored in the OOB */
static int get_logical_address(uint8_t *oob_buf)
{
- int block_address, parity;
+ int block_address;
+ bool parity;
int offset[2] = {6, 11}; /* offset of the 2 address fields within OOB */
int j;
int ok = 0;
@@ -215,7 +203,7 @@ static int get_logical_address(uint8_t *oob_buf)
block_address &= 0x7FF;
block_address >>= 1;

- if (get_parity(block_address, 10) != parity) {
+ if (parity_odd(block_address & 0x3ff) == parity) {
pr_debug("SSFDC_RO: logical address field%d"
"parity error(0x%04X)\n", j+1,
block_address);
--
2.34.1