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| author | Eric Paris <eparis@redhat.com> | 2010-10-13 17:50:02 -0400 |
|---|---|---|
| committer | James Morris <jmorris@namei.org> | 2010-10-21 10:12:53 +1100 |
| commit | 686a0f3d71203bbfcc186900bbb8ac2cfc3d803c (patch) | |
| tree | f0f1d965fe8c96d79b56c44e66c420d369549b2c | |
| parent | 1ae4de0cdf855305765592647025bde55e85e451 (diff) | |
| download | linux-686a0f3d71203bbfcc186900bbb8ac2cfc3d803c.tar.bz2 | |
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>
| -rw-r--r-- | include/linux/kernel.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 2b0a35e6bc69..6d6eea7f7b1e 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; \ |