Create a DIV_ROUND_CLOSEST macro to do division with rounding

Create a helper macro to divide two numbers and round the result to the nearest whole number. This is a helper macro for hwmon drivers that want to convert incoming sysfs values per standard hwmon practice, though the macro itself can be used by anyone. Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Create a DIV_ROUND_CLOSEST macro to do division with rounding
Create a helper macro to divide two numbers and round the result to the nearest whole number. This is a helper macro for hwmon drivers that want to convert incoming sysfs values per standard hwmon practice, though the macro itself can be used by anyone. Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Darrick J. Wong · Linus Torvalds
1 parent 3007967742
Showing 1 changed file with 6 additions and 0 deletions Side-by-side Diff
include/linux/kernel.h
@@ -48,6 +48,12 @@
 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
 #define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
+#define DIV_ROUND_CLOSEST(x, divisor)(			\
+{							\
+	typeof(divisor) __divisor = divisor;		\
+	(((x) + ((__divisor) / 2)) / (__divisor));	\
+}							\
+)
  
 #define _RET_IP_		(unsigned long)__builtin_return_address(0)
 #define _THIS_IP_  ({ __label__ __here; __here: (unsigned long)&&__here; })
...	...	@@ -48,6 +48,12 @@
48	48	#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
49	49	#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
50	50	#define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
	51	+#define DIV_ROUND_CLOSEST(x, divisor)( \
	52	+{ \
	53	+ typeof(divisor) __divisor = divisor; \
	54	+ (((x) + ((__divisor) / 2)) / (__divisor)); \
	55	+} \
	56	+)
51	57
52	58	#define _RET_IP_ (unsigned long)__builtin_return_address(0)
53	59	#define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })