Create a DIV_ROUND_CLOSEST macro to do division with rounding
Darrick J. Wong [Tue, 6 Jan 2009 22:40:51 +0000 (14:40 -0800)]
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>

include/linux/kernel.h

index ca9ff64..7219848 100644 (file)
@@ -48,6 +48,12 @@ extern const char linux_proc_banner[];
 #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; })