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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-05-21 15:29:01 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2024-05-21 15:29:01 -0700 |
| commit | 4865a27c66fda6a32511ec5492f4bbec437f512d (patch) | |
| tree | dae4d82641bb45bc97735799dd7f0aac88b34778 /include/linux/bitops.h | |
| parent | b6394d6f715919c053c1450ef0d7c5e517b53764 (diff) | |
| parent | 5671dca241b9a2f4ecf88d8e992041cfb580e0a5 (diff) | |
Merge tag 'bitmap-for-6.10v2' of https://github.com/norov/linux
Pull bitmap updates from Yury Norov:
- topology_span_sane() optimization from Kyle Meyer
- fns() rework from Kuan-Wei Chiu (used in cpumask_local_spread() and
other places)
- headers cleanup from Andy
- add a MAINTAINERS record for bitops API
* tag 'bitmap-for-6.10v2' of https://github.com/norov/linux:
usercopy: Don't use "proxy" headers
bitops: Move aligned_byte_mask() to wordpart.h
MAINTAINERS: add BITOPS API record
bitmap: relax find_nth_bit() limitation on return value
lib: make test_bitops compilable into the kernel image
bitops: Optimize fns() for improved performance
lib/test_bitops: Add benchmark test for fns()
Compiler Attributes: Add __always_used macro
sched/topology: Optimize topology_span_sane()
cpumask: Add for_each_cpu_from()
Diffstat (limited to 'include/linux/bitops.h')
| -rw-r--r-- | include/linux/bitops.h | 19 |
1 files changed, 3 insertions, 16 deletions
diff --git a/include/linux/bitops.h b/include/linux/bitops.h index 3112ae7d6524..46d4bdc634c0 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -8,13 +8,6 @@ #include <uapi/linux/kernel.h> -/* Set bits in the first 'n' bytes when loaded from memory */ -#ifdef __LITTLE_ENDIAN -# define aligned_byte_mask(n) ((1UL << 8*(n))-1) -#else -# define aligned_byte_mask(n) (~0xffUL << (BITS_PER_LONG - 8 - 8*(n))) -#endif - #define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE) #define BITS_TO_LONGS(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(long)) #define BITS_TO_U64(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u64)) @@ -257,16 +250,10 @@ static inline unsigned int __ffs64(u64 word) */ static inline unsigned int fns(unsigned long word, unsigned int n) { - unsigned int bit; - - while (word) { - bit = __ffs(word); - if (n-- == 0) - return bit; - __clear_bit(bit, &word); - } + while (word && n--) + word &= word - 1; - return BITS_PER_LONG; + return word ? __ffs(word) : BITS_PER_LONG; } /** |