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author | Alexander van Heukelum <heukelum@mailshack.com> | 2008-04-01 11:46:19 +0200 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-04-26 19:21:16 +0200 |
commit | 77b9bd9c49442407804c37bcc82021a35277f83c (patch) | |
tree | 251900d95c6c9c5371542d5dda7d89cb31cd0801 /include/linux/bitops.h | |
parent | d57594c203b1e7b54373080a797f0cbfa4aade68 (diff) | |
download | blackbird-op-linux-77b9bd9c49442407804c37bcc82021a35277f83c.tar.gz blackbird-op-linux-77b9bd9c49442407804c37bcc82021a35277f83c.zip |
x86: generic versions of find_first_(zero_)bit, convert i386
Generic versions of __find_first_bit and __find_first_zero_bit
are introduced as simplified versions of __find_next_bit and
__find_next_zero_bit. Their compilation and use are guarded by
a new config variable GENERIC_FIND_FIRST_BIT.
The generic versions of find_first_bit and find_first_zero_bit
are implemented in terms of the newly introduced __find_first_bit
and __find_first_zero_bit.
This patch does not remove the i386-specific implementation,
but it does switch i386 to use the generic functions by setting
GENERIC_FIND_FIRST_BIT=y for X86_32.
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/bitops.h')
-rw-r--r-- | include/linux/bitops.h | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/include/linux/bitops.h b/include/linux/bitops.h index 3865f2c93bd8..355d67ba3bdc 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -113,6 +113,40 @@ static inline unsigned fls_long(unsigned long l) } #ifdef __KERNEL__ +#ifdef CONFIG_GENERIC_FIND_FIRST_BIT +extern unsigned long __find_first_bit(const unsigned long *addr, + unsigned long size); + +/** + * find_first_bit - find the first set bit in a memory region + * @addr: The address to start the search at + * @size: The maximum size to search + * + * Returns the bit number of the first set bit. + */ +static __always_inline unsigned long +find_first_bit(const unsigned long *addr, unsigned long size) +{ + return __find_first_bit(addr, size); +} + +extern unsigned long __find_first_zero_bit(const unsigned long *addr, + unsigned long size); + +/** + * find_first_zero_bit - find the first cleared bit in a memory region + * @addr: The address to start the search at + * @size: The maximum size to search + * + * Returns the bit number of the first cleared bit. + */ +static __always_inline unsigned long +find_first_zero_bit(const unsigned long *addr, unsigned long size) +{ + return __find_first_zero_bit(addr, size); +} +#endif /* CONFIG_GENERIC_FIND_FIRST_BIT */ + #ifdef CONFIG_GENERIC_FIND_NEXT_BIT extern unsigned long __find_next_bit(const unsigned long *addr, unsigned long size, unsigned long offset); |