Commit 686a0f3d authored by Eric Paris's avatar Eric Paris Committed by James Morris

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: default avatarEric Paris <eparis@redhat.com>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
parent 1ae4de0c
...@@ -59,6 +59,12 @@ extern const char linux_proc_banner[]; ...@@ -59,6 +59,12 @@ extern const char linux_proc_banner[];
#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f)) #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d)) #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
#define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y)) #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)( \ #define DIV_ROUND_CLOSEST(x, divisor)( \
{ \ { \
typeof(divisor) __divisor = divisor; \ typeof(divisor) __divisor = divisor; \
......
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