diff options
| author | Andreas Herrmann <andreas.herrmann3@amd.com> | 2010-08-30 19:04:01 +0000 |
|---|---|---|
| committer | John W. Linville <linville@tuxdriver.com> | 2010-11-15 13:27:04 -0500 |
| commit | 7919a57bc608140aa8614c19eac40c6916fb61d2 (patch) | |
| tree | 0813ff8983a937eae8636808167bc59aa0e80c34 /include/linux/bitops.h | |
| parent | e4b3fdb80021bc0a3239bfc2a873a6d7c6ac52a1 (diff) | |
| download | lwn-7919a57bc608140aa8614c19eac40c6916fb61d2.tar.gz lwn-7919a57bc608140aa8614c19eac40c6916fb61d2.zip | |
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.h | 11 |
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) |