linux-kernel - [PATCH 1/3] cputime_nsecs: use math64.h for nsec resolution conversion helpers

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Message-Id: <1363822467-6275-2-git-send-email-khilman@linaro.org>
Date:	Wed, 20 Mar 2013 16:34:25 -0700
From:	Kevin Hilman <khilman@...aro.org>
To:	Frederic Weisbecker <fweisbec@...il.com>,
	Russell King <rmk+kernel@....linux.org.uk>,
	linux-kernel@...r.kernel.org
Cc:	Paul McKenney <paulmck@...ux.vnet.ibm.com>,
	linux-arm-kernel@...ts.infradead.org,
	linaro-kernel@...ts.linaro.org
Subject: [PATCH 1/3] cputime_nsecs: use math64.h for nsec resolution conversion helpers

For the nsec resolution conversions to be useable on non 64-bit
architectures, the helpers in <linux/math64.h> need to be used so the
right arch-specific 64-bit math helpers can be used (e.g. do_div())

Cc: Frederic Weisbecker <fweisbec@...il.com>
Signed-off-by: Kevin Hilman <khilman@...aro.org>
---
 include/asm-generic/cputime_nsecs.h | 28 +++++++++++++++++++---------
 1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/include/asm-generic/cputime_nsecs.h b/include/asm-generic/cputime_nsecs.h
index a8ece9a..2c9e62c 100644
--- a/include/asm-generic/cputime_nsecs.h
+++ b/include/asm-generic/cputime_nsecs.h
@@ -16,21 +16,27 @@
 #ifndef _ASM_GENERIC_CPUTIME_NSECS_H
 #define _ASM_GENERIC_CPUTIME_NSECS_H
 
+#include <linux/math64.h>
+
 typedef u64 __nocast cputime_t;
 typedef u64 __nocast cputime64_t;
 
 #define cputime_one_jiffy		jiffies_to_cputime(1)
 
+#define cputime_div(__ct, divisor)  div_u64((__force u64)__ct, divisor)
+#define cputime_div_rem(__ct, divisor, remainder) \
+	div_u64_rem((__force u64)__ct, divisor, remainder);
+
 /*
  * Convert cputime <-> jiffies (HZ)
  */
 #define cputime_to_jiffies(__ct)	\
-	((__force u64)(__ct) / (NSEC_PER_SEC / HZ))
+	cputime_div(__ct, NSEC_PER_SEC / HZ)
 #define cputime_to_scaled(__ct)		(__ct)
 #define jiffies_to_cputime(__jif)	\
 	(__force cputime_t)((__jif) * (NSEC_PER_SEC / HZ))
 #define cputime64_to_jiffies64(__ct)	\
-	((__force u64)(__ct) / (NSEC_PER_SEC / HZ))
+	cputime_div(__ct, NSEC_PER_SEC / HZ)
 #define jiffies64_to_cputime64(__jif)	\
 	(__force cputime64_t)((__jif) * (NSEC_PER_SEC / HZ))
 
@@ -45,7 +51,7 @@ typedef u64 __nocast cputime64_t;
  * Convert cputime <-> microseconds
  */
 #define cputime_to_usecs(__ct)		\
-	((__force u64)(__ct) / NSEC_PER_USEC)
+	cputime_div(__ct, NSEC_PER_USEC)
 #define usecs_to_cputime(__usecs)	\
 	(__force cputime_t)((__usecs) * NSEC_PER_USEC)
 #define usecs_to_cputime64(__usecs)	\
@@ -55,7 +61,7 @@ typedef u64 __nocast cputime64_t;
  * Convert cputime <-> seconds
  */
 #define cputime_to_secs(__ct)		\
-	((__force u64)(__ct) / NSEC_PER_SEC)
+	cputime_div(__ct, NSEC_PER_SEC)
 #define secs_to_cputime(__secs)		\
 	(__force cputime_t)((__secs) * NSEC_PER_SEC)
 
@@ -69,8 +75,10 @@ static inline cputime_t timespec_to_cputime(const struct timespec *val)
 }
 static inline void cputime_to_timespec(const cputime_t ct, struct timespec *val)
 {
-	val->tv_sec  = (__force u64) ct / NSEC_PER_SEC;
-	val->tv_nsec = (__force u64) ct % NSEC_PER_SEC;
+	u32 rem;
+
+	val->tv_sec = cputime_div_rem(ct, NSEC_PER_SEC, &rem);
+	val->tv_nsec = rem;
 }
 
 /*
@@ -83,15 +91,17 @@ static inline cputime_t timeval_to_cputime(const struct timeval *val)
 }
 static inline void cputime_to_timeval(const cputime_t ct, struct timeval *val)
 {
-	val->tv_sec = (__force u64) ct / NSEC_PER_SEC;
-	val->tv_usec = ((__force u64) ct % NSEC_PER_SEC) / NSEC_PER_USEC;
+	u32 rem;
+
+	val->tv_sec = cputime_div_rem(ct, NSEC_PER_SEC, &rem);
+	val->tv_usec = rem / NSEC_PER_USEC;
 }
 
 /*
  * Convert cputime <-> clock (USER_HZ)
  */
 #define cputime_to_clock_t(__ct)	\
-	((__force u64)(__ct) / (NSEC_PER_SEC / USER_HZ))
+	cputime_div(__ct, (NSEC_PER_SEC / USER_HZ))
 #define clock_t_to_cputime(__x)		\
 	(__force cputime_t)((__x) * (NSEC_PER_SEC / USER_HZ))
 
-- 
1.8.2

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