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authorEric Paris <eparis@redhat.com>2010-10-13 17:50:02 -0400
committerJames Morris <jmorris@namei.org>2010-10-21 10:12:53 +1100
commit686a0f3d71203bbfcc186900bbb8ac2cfc3d803c (patch)
treef0f1d965fe8c96d79b56c44e66c420d369549b2c /include/linux/kernel.h
parent1ae4de0cdf855305765592647025bde55e85e451 (diff)
kernel: rounddown helper function
The roundup() helper function will round a given value up to a multiple of another given value. aka roundup(11, 7) would give 14 = 7 * 2. This new function does the opposite. It will round a given number down to the nearest multiple of the second number: rounddown(11, 7) would give 7. I need this in some future SELinux code and can carry the macro myself, but figured I would put it in the core kernel so others might find and use it if need be. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'include/linux/kernel.h')
-rw-r--r--include/linux/kernel.h6
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 2b0a35e6bc6..6d6eea7f7b1 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -59,6 +59,12 @@ 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 rounddown(x, y) ( \
+{ \
+ typeof(x) __x = (x); \
+ __x - (__x % (y)); \
+} \
+)
#define DIV_ROUND_CLOSEST(x, divisor)( \
{ \
typeof(divisor) __divisor = divisor; \