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Date: Thu, 21 Feb 2013 09:58:57 -0800
From: Namhyung Kim <namhyung@...nel.org>
To: Kevin Hilman <khilman@...aro.org>
Cc: Frederic Weisbecker <fweisbec@...il.com>,
Mats Liljegren <mats.liljegren@...a.com>,
linaro-dev@...ts.linaro.org, linux-kernel@...r.kernel.org,
linux-arm-kernel@...ts.infradead.org
Subject: Re: [RFC/PATCH 4/5] cputime: use do_div() for nsec resolution
conversion helpers
Hi Kevin,
On Wed, Feb 20, 2013 at 11:41:41AM -0800, Kevin Hilman wrote:
> For the nsec resolution conversions to be useful on non 64-bit
> architectures, do_div() needs to be used for the 64-bit divisions.
>
> Signed-off-by: Kevin Hilman <khilman@...aro.org>
> ---
> include/asm-generic/cputime_nsecs.h | 51 +++++++++++++++++++++++++++----------
> 1 file changed, 37 insertions(+), 14 deletions(-)
>
> diff --git a/include/asm-generic/cputime_nsecs.h b/include/asm-generic/cputime_nsecs.h
> index b6485ca..daa6075 100644
> --- a/include/asm-generic/cputime_nsecs.h
> +++ b/include/asm-generic/cputime_nsecs.h
> @@ -24,13 +24,17 @@ typedef u64 __nocast cputime64_t;
> /*
> * Convert cputime <-> jiffies (HZ)
> */
> -#define cputime_to_jiffies(__ct) \
> - ((__force u64)(__ct) / (NSEC_PER_SEC / HZ))
> +static inline u64 cputime_to_jiffies(const cputime_t ct)
> +{
> + cputime_t __ct = ct;
Why it removed the "(__force u64)" conversion part? Shouldn't it be:
u64 __ct = (__force u64) ct;
? (and ditto for below changes)
Thanks,
Namhyung
> +
> + do_div(__ct, NSEC_PER_SEC / HZ);
> + return __ct;
> +}
> #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))
> +#define cputime64_to_jiffies64(__ct) cputime_to_jiffies(__ct)
> #define jiffies64_to_cputime64(__jif) \
> (__force cputime64_t)((__jif) * (NSEC_PER_SEC / HZ))
>
> @@ -44,8 +48,13 @@ typedef u64 __nocast cputime64_t;
> /*
> * Convert cputime <-> microseconds
> */
> -#define cputime_to_usecs(__ct) \
> - ((__force u64)(__ct) / NSEC_PER_USEC)
> +static inline u64 cputime_to_usecs(const cputime_t ct)
> +{
> + cputime_t __ct = ct;
> +
> + do_div(__ct, NSEC_PER_USEC);
> + return __ct;
> +}
> #define usecs_to_cputime(__usecs) \
> (__force cputime_t)((__usecs) * NSEC_PER_USEC)
> #define usecs_to_cputime64(__usecs) \
> @@ -54,8 +63,13 @@ typedef u64 __nocast cputime64_t;
> /*
> * Convert cputime <-> seconds
> */
> -#define cputime_to_secs(__ct) \
> - ((__force u64)(__ct) / NSEC_PER_SEC)
> +static inline u64 cputime_to_secs(const cputime_t ct)
> +{
> + cputime_t __ct = ct;
> +
> + do_div(__ct, NSEC_PER_SEC);
> + return __ct;
> +}
> #define secs_to_cputime(__secs) \
> (__force cputime_t)((__secs) * NSEC_PER_SEC)
>
> @@ -69,8 +83,10 @@ 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;
> + cputime_t __ct = ct;
> +
> + val->tv_nsec = do_div(__ct, NSEC_PER_SEC);
> + val->tv_sec = __ct;
> }
>
> /*
> @@ -83,15 +99,22 @@ static inline cputime_t timeval_to_cputime(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;
> + cputime_t __ct = ct;
> +
> + val->tv_usec = do_div(__ct, NSEC_PER_SEC) / NSEC_PER_USEC;
> + val->tv_sec = __ct;
> }
>
> /*
> * Convert cputime <-> clock (USER_HZ)
> */
> -#define cputime_to_clock_t(__ct) \
> - ((__force u64)(__ct) / (NSEC_PER_SEC / USER_HZ))
> +static inline u64 cputime_to_clock_t(const cputime_t ct)
> +{
> + cputime_t __ct = ct;
> +
> + do_div(__ct, (NSEC_PER_SEC / USER_HZ));
> + return __ct;
> +}
> #define clock_t_to_cputime(__x) \
> (__force cputime_t)((__x) * (NSEC_PER_SEC / USER_HZ))
>
> --
> 1.8.1.2
>
>
> _______________________________________________
> linaro-dev mailing list
> linaro-dev@...ts.linaro.org
> http://lists.linaro.org/mailman/listinfo/linaro-dev
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