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include/linux/kernel.h: deduplicate code implementing clamp* macros
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Instead of open-coding clamp_t macro min_t and max_t the way clamp macro
does and instead of open-coding clamp_val simply use clamp_t.
Furthermore, normalise argument naming in the macros to be lo and hi.

Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Mark Rustad <mark.d.rustad@intel.com>
Cc: "Kirsher, Jeffrey T" <jeffrey.t.kirsher@intel.com>
Cc: Hagen Paul Pfeifer <hagen@jauu.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Michal Nazarewicz authored and Linus Torvalds committed Oct 10, 2014
1 parent 2e1d06e commit c185b07
Showing 1 changed file with 7 additions and 17 deletions.
24 changes: 7 additions & 17 deletions include/linux/kernel.h
Original file line number Diff line number Diff line change
Expand Up @@ -734,7 +734,7 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
* @lo: lowest allowable value
* @hi: highest allowable value
*
* This macro does strict typechecking of min/max to make sure they are of the
* This macro does strict typechecking of lo/hi to make sure they are of the
* same type as val. See the unnecessary pointer comparisons.
*/
#define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi)
Expand All @@ -759,36 +759,26 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
* 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
* @lo: minimum allowable value
* @hi: 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); \
type __max = (max); \
__val = __val < __min ? __min: __val; \
__val > __max ? __max: __val; })
#define clamp_t(type, val, lo, hi) min_t(type, max_t(type, val, lo), hi)

/**
* 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
* @lo: minimum allowable value
* @hi: 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); \
typeof(val) __max = (max); \
__val = __val < __min ? __min: __val; \
__val > __max ? __max: __val; })
#define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi)


/*
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