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| author |   Yury Norov <yury.norov@gmail.com> | 2022-09-14 19:07:28 -0700 |
|---|---|---|
| committer | Yury Norov <yury.norov@gmail.com> | 2022-09-21 12:17:18 -0700 |
| commit | 14a99e130f2758bc826a7e7a8bdf6f7400b54f0f (patch) | |
| tree | 3b067dad53502e8e00c0fce608fe3b2587f2be91 | |
| parent | lib/find_bit: introduce FIND_FIRST_BIT() macro (diff) | |
| download | linux-dev-14a99e130f2758bc826a7e7a8bdf6f7400b54f0f.tar.xz linux-dev-14a99e130f2758bc826a7e7a8bdf6f7400b54f0f.zip | |
lib/find_bit: create find_first_zero_bit_le()
find_first_zero_bit_le() is an alias to find_next_zero_bit_le(),
despite that 'next' is known to be slower than 'first' version.
Now that we have common FIND_FIRST_BIT() macro helper, it's trivial
to implement find_first_zero_bit_le() as a real function.
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
| -rw-r--r-- | include/linux/find.h | 23 | ||||
| -rw-r--r-- | lib/find_bit.c | 16 |
2 files changed, 34 insertions, 5 deletions
diff --git a/include/linux/find.h b/include/linux/find.h index 424ef67d4a42..2464bff5de04 100644 --- a/include/linux/find.h +++ b/include/linux/find.h @@ -17,6 +17,10 @@ extern unsigned long _find_first_and_bit(const unsigned long *addr1, extern unsigned long _find_first_zero_bit(const unsigned long *addr, unsigned long size); extern unsigned long _find_last_bit(const unsigned long *addr, unsigned long size); +#ifdef __BIG_ENDIAN +unsigned long _find_first_zero_bit_le(const unsigned long *addr, unsigned long size); +#endif + #ifndef find_next_bit /** * find_next_bit - find the next set bit in a memory region @@ -251,6 +255,20 @@ unsigned long find_next_zero_bit_le(const void *addr, unsigned } #endif +#ifndef find_first_zero_bit_le +static inline +unsigned long find_first_zero_bit_le(const void *addr, unsigned long size) +{ + if (small_const_nbits(size)) { + unsigned long val = swab(*(const unsigned long *)addr) | ~GENMASK(size - 1, 0); + + return val == ~0UL ? size : ffz(val); + } + + return _find_first_zero_bit_le(addr, size); +} +#endif + #ifndef find_next_bit_le static inline unsigned long find_next_bit_le(const void *addr, unsigned @@ -270,11 +288,6 @@ unsigned long find_next_bit_le(const void *addr, unsigned } #endif -#ifndef find_first_zero_bit_le -#define find_first_zero_bit_le(addr, size) \ - find_next_zero_bit_le((addr), (size), 0) -#endif - #else #error "Please fix <asm/byteorder.h>" #endif diff --git a/lib/find_bit.c b/lib/find_bit.c index 894b656f6836..61ec2992938b 100644 --- a/lib/find_bit.c +++ b/lib/find_bit.c @@ -160,3 +160,19 @@ unsigned long find_next_clump8(unsigned long *clump, const unsigned long *addr, return offset; } EXPORT_SYMBOL(find_next_clump8); + +#ifdef __BIG_ENDIAN + +#ifndef find_first_zero_bit_le +/* + * Find the first cleared bit in an LE memory region. + */ +unsigned long _find_first_zero_bit_le(const unsigned long *addr, unsigned long size) +{ + return FIND_FIRST_BIT(~addr[idx], swab, size); +} +EXPORT_SYMBOL(_find_first_zero_bit_le); + +#endif + +#endif /* __BIG_ENDIAN */ |