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authorAndreas Herrmann <andreas.herrmann3@amd.com>2010-08-30 19:04:01 +0000
committerJohn W. Linville <linville@tuxdriver.com>2010-11-15 13:27:04 -0500
commit7919a57bc608140aa8614c19eac40c6916fb61d2 (patch)
tree0813ff8983a937eae8636808167bc59aa0e80c34 /include/linux/bitops.h
parente4b3fdb80021bc0a3239bfc2a873a6d7c6ac52a1 (diff)
bitops: Provide generic sign_extend32 function
This patch moves code out from wireless drivers where two different functions are defined in three code locations for the same purpose and provides a common function to sign extend a 32-bit value. Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'include/linux/bitops.h')
-rw-r--r--include/linux/bitops.h11
1 files changed, 11 insertions, 0 deletions
diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index 827cc95711ef..2184c6b97aeb 100644
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -109,6 +109,17 @@ static inline __u8 ror8(__u8 word, unsigned int shift)
return (word >> shift) | (word << (8 - shift));
}
+/**
+ * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
+ * @value: value to sign extend
+ * @index: 0 based bit index (0<=index<32) to sign bit
+ */
+static inline __s32 sign_extend32(__u32 value, int index)
+{
+ __u8 shift = 31 - index;
+ return (__s32)(value << shift) >> shift;
+}
+
static inline unsigned fls_long(unsigned long l)
{
if (sizeof(l) == 4)