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Subject[RFC PATCH 1/6] kenrel.h: add ALIGN_OF_LAST_BIT()
Date
Get the biggest 2**y that x % (2**y) == 0 for the align value. 

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
---
include/linux/kernel.h | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 5113462..2c439dc 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -44,6 +44,8 @@
#define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a)))
#define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0)

+#define ALIGN_OF_LAST_BIT(x) ((((x)^((x) - 1))>>1) + 1)
+
#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))

/*
--
1.7.4.4


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