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SubjectRe: [PATCH] add kerneldoc for clamp(), clamp_t(), clamp_val() macros
On Fri, 14 Mar 2008 12:58:49 -0700 Harvey Harrison wrote:

> Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>

Acked-by: Randy Dunlap <randy.dunlap@oracle.com>

Thanks, Harvey.

> ---
> include/linux/kernel.h | 30 ++++++++++++++++++++++++++++++
> 1 files changed, 30 insertions(+), 0 deletions(-)
>
> diff --git a/include/linux/kernel.h b/include/linux/kernel.h
> index c74460c..d57e537 100644
> --- a/include/linux/kernel.h
> +++ b/include/linux/kernel.h
> @@ -351,6 +351,15 @@ static inline int __attribute__ ((format (printf, 1, 2))) pr_debug(const char *
> (void) (&_max1 == &_max2); \
> _max1 > _max2 ? _max1 : _max2; })
>
> +/**
> + * clamp - return a value clamped to a given range with strict typechecking
> + * @val: current value
> + * @min: minimum allowable value
> + * @max: maximum allowable value
> + *
> + * This macro does strict typechecking of min/max to make sure they are of the
> + * same type as val. See the unnecessary pointer comparisons.
> + */
> #define clamp(val, min, max) ({ \
> typeof(val) __val = (val); \
> typeof(min) __min = (min); \
> @@ -376,6 +385,16 @@ static inline int __attribute__ ((format (printf, 1, 2))) pr_debug(const char *
> type __max2 = (y); \
> __max1 > __max2 ? __max1: __max2; })
>
> +/**
> + * clamp_t - return a value clamped to a given range using a given type
> + * @type: the type of variable to use
> + * @val: current value
> + * @min: minimum allowable value
> + * @max: maximum allowable value
> + *
> + * This macro does no typechecking and uses temporary variables of type
> + * 'type' to make all the comparisons.
> + */
> #define clamp_t(type, val, min, max) ({ \
> type __val = (val); \
> type __min = (min); \
> @@ -383,6 +402,17 @@ static inline int __attribute__ ((format (printf, 1, 2))) pr_debug(const char *
> __val = __val < __min ? __min: __val; \
> __val > __max ? __max: __val; })
>
> +/**
> + * clamp_val - return a value clamped to a given range using val's type
> + * @val: current value
> + * @min: minimum allowable value
> + * @max: maximum allowable value
> + *
> + * This macro does no typechecking and uses temporary variables of whatever
> + * type the input argument 'val' is. This is useful when val is an unsigned
> + * type and min and max are literals that will otherwise be assigned a signed
> + * integer type.
> + */
> #define clamp_val(val, min, max) ({ \
> typeof(val) __val = (val); \
> typeof(val) __min = (min); \
> --

---
~Randy


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