[PATCH 21/31] mtd: use parity16 in ssfdc.c

[PATCH 21/31] mtd: use parity16 in ssfdc.c

[zhaoxiu.zeng]

From: Zeng Zhaoxiu <zhaoxiu.zeng@gmail.com>

Signed-off-by: Zeng Zhaoxiu <zhaoxiu.zeng@gmail.com>
---
 drivers/mtd/ssfdc.c | 20 ++------------------
 1 file changed, 2 insertions(+), 18 deletions(-)

diff --git a/drivers/mtd/ssfdc.c b/drivers/mtd/ssfdc.c
index daf82ba..b4d9144 100644
--- a/drivers/mtd/ssfdc.c
+++ b/drivers/mtd/ssfdc.c
@@ -182,24 +182,10 @@ 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;
 	int offset[2] = {6, 11}; /* offset of the 2 address fields within OOB */
 	int j;
 	int ok = 0;
@@ -215,11 +201,9 @@ static int get_logical_address(uint8_t *oob_buf)
 
 		/* Check for the signature bits in the address field (MSBits) */
 		if ((block_address & ~0x7FF) == 0x1000) {
-			parity = block_address & 0x01;
 			block_address &= 0x7FF;
-			block_address >>= 1;
 
-			if (get_parity(block_address, 10) != parity) {
+			if (!parity16(block_address)) {
 				pr_debug("SSFDC_RO: logical address field%d"
 					"parity error(0x%04X)\n", j+1,
 					block_address);
-- 
2.5.5

[PATCH 22/31] mtd: use parity functions in inftlcore.c

[zhaoxiu.zeng]

From: Zeng Zhaoxiu <zhaoxiu.zeng@gmail.com>

Signed-off-by: Zeng Zhaoxiu <zhaoxiu.zeng@gmail.com>
---
 drivers/mtd/inftlcore.c | 17 ++++-------------
 1 file changed, 4 insertions(+), 13 deletions(-)

diff --git a/drivers/mtd/inftlcore.c b/drivers/mtd/inftlcore.c
index b66b541..29567bb 100644
--- a/drivers/mtd/inftlcore.c
+++ b/drivers/mtd/inftlcore.c
@@ -457,15 +457,6 @@ static u16 INFTL_makefreeblock(struct INFTLrecord *inftl, unsigned pendingblock)
 	return INFTL_foldchain(inftl, LongestChain, pendingblock);
 }
 
-static int nrbits(unsigned int val, int bitcount)
-{
-	int i, total = 0;
-
-	for (i = 0; (i < bitcount); i++)
-		total += (((0x1 << i) & val) ? 1 : 0);
-	return total;
-}
-
 /*
  * INFTL_findwriteunit: Return the unit number into which we can write
  *                      for this block. Make it available if it isn't already.
@@ -593,10 +584,10 @@ hitused:
 		if (prev_block < inftl->nb_blocks)
 			prev_block -= inftl->firstEUN;
 
-		parity = (nrbits(thisVUC, 16) & 0x1) ? 0x1 : 0;
-		parity |= (nrbits(prev_block, 16) & 0x1) ? 0x2 : 0;
-		parity |= (nrbits(anac, 8) & 0x1) ? 0x4 : 0;
-		parity |= (nrbits(nacs, 8) & 0x1) ? 0x8 : 0;
+		parity = parity16(thisVUC);
+		parity |= parity16(prev_block) << 1;
+		parity |= parity8(anac) << 2;
+		parity |= parity8(nacs) << 3;
 
 		oob.u.a.virtualUnitNo = cpu_to_le16(thisVUC);
 		oob.u.a.prevUnitNo = cpu_to_le16(prev_block);
-- 
2.5.5

[PATCH 24/31] mtd: use parity16 in sm_ftl.c

[zhaoxiu.zeng]

From: Zeng Zhaoxiu <zhaoxiu.zeng@gmail.com>

Signed-off-by: Zeng Zhaoxiu <zhaoxiu.zeng@gmail.com>
---
 drivers/mtd/sm_ftl.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/sm_ftl.c b/drivers/mtd/sm_ftl.c
index b096f8b..2244588 100644
--- a/drivers/mtd/sm_ftl.c
+++ b/drivers/mtd/sm_ftl.c
@@ -136,7 +136,7 @@ static int sm_get_lba(uint8_t *lba)
 		return -2;
 
 	/* check parity - endianness doesn't matter */
-	if (hweight16(*(uint16_t *)lba) & 1)
+	if (parity16(*(uint16_t *)lba))
 		return -2;
 
 	return (lba[1] >> 1) | ((lba[0] & 0x07) << 7);
@@ -183,7 +183,7 @@ static void sm_write_lba(struct sm_oob *oob, uint16_t lba)
 	tmp[0] = 0x10 | ((lba >> 7) & 0x07);
 	tmp[1] = (lba << 1) & 0xFF;
 
-	if (hweight16(*(uint16_t *)tmp) & 0x01)
+	if (parity16(*(uint16_t *)tmp))
 		tmp[1] |= 1;
 
 	oob->lba_copy1[0] = oob->lba_copy2[0] = tmp[0];
-- 
2.5.5

Re: [PATCH 21/31] mtd: use parity16 in ssfdc.c

[Brian Norris]

On Sun, Mar 27, 2016 at 03:24:59PM +0800, zhaoxiu.zeng wrote:
> From: Zeng Zhaoxiu <zhaoxiu.zeng@gmail.com>
> 
> Signed-off-by: Zeng Zhaoxiu <zhaoxiu.zeng@gmail.com>

I'm not CC'd on the rest of this series, where you defined parity16().
And I doubt you've tested this. So I'm not applying.

Brian

>  drivers/mtd/ssfdc.c | 20 ++------------------
>  1 file changed, 2 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/mtd/ssfdc.c b/drivers/mtd/ssfdc.c
> index daf82ba..b4d9144 100644
> --- a/drivers/mtd/ssfdc.c
> +++ b/drivers/mtd/ssfdc.c
> @@ -182,24 +182,10 @@ 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;
>  	int offset[2] = {6, 11}; /* offset of the 2 address fields within OOB */
>  	int j;
>  	int ok = 0;
> @@ -215,11 +201,9 @@ static int get_logical_address(uint8_t *oob_buf)
>  
>  		/* Check for the signature bits in the address field (MSBits) */
>  		if ((block_address & ~0x7FF) == 0x1000) {
> -			parity = block_address & 0x01;
>  			block_address &= 0x7FF;
> -			block_address >>= 1;
>  
> -			if (get_parity(block_address, 10) != parity) {
> +			if (!parity16(block_address)) {
>  				pr_debug("SSFDC_RO: logical address field%d"
>  					"parity error(0x%04X)\n", j+1,
>  					block_address);
> -- 
> 2.5.5
>