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authorLinus Torvalds <torvalds@linux-foundation.org>2018-08-22 22:34:08 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-08-22 22:34:08 +0300
commitcd9b44f90763c3367e8dd0601849ffb028e8ba52 (patch)
treed1da0c2d49e3622fe51584a154ab383b3e783c1b /include/linux/kernel.h
parentdf2def49c57b4146520a1f4ca37bc3f494e2cd67 (diff)
parent2a9d6481004215da8e93edb588cf448f2af80303 (diff)
downloadlinux-cd9b44f90763c3367e8dd0601849ffb028e8ba52.tar.xz
Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton: - the rest of MM - procfs updates - various misc things - more y2038 fixes - get_maintainer updates - lib/ updates - checkpatch updates - various epoll updates - autofs updates - hfsplus - some reiserfs work - fatfs updates - signal.c cleanups - ipc/ updates * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (166 commits) ipc/util.c: update return value of ipc_getref from int to bool ipc/util.c: further variable name cleanups ipc: simplify ipc initialization ipc: get rid of ids->tables_initialized hack lib/rhashtable: guarantee initial hashtable allocation lib/rhashtable: simplify bucket_table_alloc() ipc: drop ipc_lock() ipc/util.c: correct comment in ipc_obtain_object_check ipc: rename ipcctl_pre_down_nolock() ipc/util.c: use ipc_rcu_putref() for failues in ipc_addid() ipc: reorganize initialization of kern_ipc_perm.seq ipc: compute kern_ipc_perm.id under the ipc lock init/Kconfig: remove EXPERT from CHECKPOINT_RESTORE fs/sysv/inode.c: use ktime_get_real_seconds() for superblock stamp adfs: use timespec64 for time conversion kernel/sysctl.c: fix typos in comments drivers/rapidio/devices/rio_mport_cdev.c: remove redundant pointer md fork: don't copy inconsistent signal handler state to child signal: make get_signal() return bool signal: make sigkill_pending() return bool ...
Diffstat (limited to 'include/linux/kernel.h')
-rw-r--r--include/linux/kernel.h35
1 files changed, 34 insertions, 1 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 941dc0a5a877..d6aac75b51ba 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -85,7 +85,23 @@
* arguments just once each.
*/
#define __round_mask(x, y) ((__typeof__(x))((y)-1))
+/**
+ * round_up - round up to next specified power of 2
+ * @x: the value to round
+ * @y: multiple to round up to (must be a power of 2)
+ *
+ * Rounds @x up to next multiple of @y (which must be a power of 2).
+ * To perform arbitrary rounding up, use roundup() below.
+ */
#define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
+/**
+ * round_down - round down to next specified power of 2
+ * @x: the value to round
+ * @y: multiple to round down to (must be a power of 2)
+ *
+ * Rounds @x down to next multiple of @y (which must be a power of 2).
+ * To perform arbitrary rounding down, use rounddown() below.
+ */
#define round_down(x, y) ((x) & ~__round_mask(x, y))
/**
@@ -110,13 +126,30 @@
# define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d)
#endif
-/* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */
+/**
+ * roundup - round up to the next specified multiple
+ * @x: the value to up
+ * @y: multiple to round up to
+ *
+ * Rounds @x up to next multiple of @y. If @y will always be a power
+ * of 2, consider using the faster round_up().
+ *
+ * The `const' here prevents gcc-3.3 from calling __divdi3
+ */
#define roundup(x, y) ( \
{ \
const typeof(y) __y = y; \
(((x) + (__y - 1)) / __y) * __y; \
} \
)
+/**
+ * rounddown - round down to next specified multiple
+ * @x: the value to round
+ * @y: multiple to round down to
+ *
+ * Rounds @x down to next multiple of @y. If @y will always be a power
+ * of 2, consider using the faster round_down().
+ */
#define rounddown(x, y) ( \
{ \
typeof(x) __x = (x); \