qemu-common: add QEMU_ALIGN_DOWN() and QEMU_ALIGN_UP() macros

Add macros for aligning a number to a multiple, for example:

QEMU_ALIGN_DOWN(500, 2000) = 0
QEMU_ALIGN_UP(500, 2000) = 2000

Since ALIGN_UP() is a common macro name use the QEMU_* namespace prefix.
Hopefully this will protect us from included headers that leak something
with a similar name.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Stefan Hajnoczi 2011-11-17 13:40:25 +00:00 committed by Kevin Wolf
parent 060f51c9de
commit 3951690a4a
1 changed files with 6 additions and 0 deletions

View File

@ -341,6 +341,12 @@ static inline uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c)
return res.ll;
}
/* Round number down to multiple */
#define QEMU_ALIGN_DOWN(n, m) ((n) / (m) * (m))
/* Round number up to multiple */
#define QEMU_ALIGN_UP(n, m) QEMU_ALIGN_DOWN((n) + (m) - 1, (m))
#include "module.h"
#endif