linux-kernel - [PATCH v2 2/7] staging: most: Using macro DIV_ROUND

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 22 Feb 2017 14:40:15 +0530
From:   simran singhal <singhalsimran0@...il.com>
To:     gregkh@...uxfoundation.org
Cc:     devel@...verdev.osuosl.org, linux-kernel@...r.kernel.org,
        outreachy-kernel@...glegroups.com
Subject: [PATCH v2 2/7] staging: most: Using macro DIV_ROUND_UP

The macro DIV_ROUND_UP performs the computation (((n) + (d) - 1) /(d)).
It clarifies the divisor calculations. This occurence was detected using
the coccinelle script:

@@
expression e1;
expression e2;
@@
(
- ((e1) + e2 - 1) / (e2)
+ DIV_ROUND_UP(e1,e2)
|
- ((e1) + (e2 - 1)) / (e2)
+ DIV_ROUND_UP(e1,e2)
)

Signed-off-by: simran singhal <singhalsimran0@...il.com>
---
 
 v2:
   -Included kernel.h as DIV_ROUND_UP is defined in it,
    before it was giving compilation error.

 drivers/staging/most/hdm-dim2/dim2_hal.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/most/hdm-dim2/dim2_hal.c b/drivers/staging/most/hdm-dim2/dim2_hal.c
index 0b9816c..d604ec09 100644
--- a/drivers/staging/most/hdm-dim2/dim2_hal.c
+++ b/drivers/staging/most/hdm-dim2/dim2_hal.c
@@ -18,6 +18,7 @@
 #include "dim2_errors.h"
 #include "dim2_reg.h"
 #include <linux/stddef.h>
+#include <linux/kernel.h>
 
 /*
  * Size factor for isochronous DBR buffer.
@@ -49,7 +50,7 @@
 #define DBR_SIZE  (16 * 1024) /* specified by IP */
 #define DBR_BLOCK_SIZE  (DBR_SIZE / 32 / DBR_MAP_SIZE)
 
-#define ROUND_UP_TO(x, d)  (((x) + (d) - 1) / (d) * (d))
+#define ROUND_UP_TO(x, d)  (DIV_ROUND_UP(x, (d)) * (d))
 
 /* -------------------------------------------------------------------------- */
 /* generic helper functions and macros */
@@ -117,7 +118,7 @@ static int alloc_dbr(u16 size)
 		return DBR_SIZE; /* out of memory */
 
 	for (i = 0; i < DBR_MAP_SIZE; i++) {
-		u32 const blocks = (size + DBR_BLOCK_SIZE - 1) / DBR_BLOCK_SIZE;
+		u32 const blocks = DIV_ROUND_UP(size, DBR_BLOCK_SIZE);
 		u32 mask = ~((~(u32)0) << blocks);
 
 		do {
@@ -137,7 +138,7 @@ static int alloc_dbr(u16 size)
 static void free_dbr(int offs, int size)
 {
 	int block_idx = offs / DBR_BLOCK_SIZE;
-	u32 const blocks = (size + DBR_BLOCK_SIZE - 1) / DBR_BLOCK_SIZE;
+	u32 const blocks = DIV_ROUND_UP(size, DBR_BLOCK_SIZE);
 	u32 mask = ~((~(u32)0) << blocks);
 
 	mask <<= block_idx % 32;
-- 
2.7.4