diff options
| author | Maxime Ripard <maxime@cerno.tech> | 2022-10-18 15:00:03 +0200 |
|---|---|---|
| committer | Maxime Ripard <maxime@cerno.tech> | 2022-10-18 15:00:03 +0200 |
| commit | a140a6a2d5ec0329ad05cd3532a91ad0ce58dceb (patch) | |
| tree | b2d44a1da423c53bd6c3ab3facd45ff5f2087ffd /include/linux/bitops.h | |
| parent | 28743e25fa1c867675bd8ff976eb92d4251f13a1 (diff) | |
| parent | 9abf2313adc1ca1b6180c508c25f22f9395cc780 (diff) | |
Merge drm/drm-next into drm-misc-next
Let's kick-off this release cycle.
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Diffstat (limited to 'include/linux/bitops.h')
| -rw-r--r-- | include/linux/bitops.h | 31 |
1 files changed, 26 insertions, 5 deletions
diff --git a/include/linux/bitops.h b/include/linux/bitops.h index cf9bf65039f2..2ba557e067fe 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -59,6 +59,7 @@ extern unsigned long __sw_hweight64(__u64 w); #define __test_and_clear_bit(nr, addr) bitop(___test_and_clear_bit, nr, addr) #define __test_and_change_bit(nr, addr) bitop(___test_and_change_bit, nr, addr) #define test_bit(nr, addr) bitop(_test_bit, nr, addr) +#define test_bit_acquire(nr, addr) bitop(_test_bit_acquire, nr, addr) /* * Include this here because some architectures need generic_ffs/fls in @@ -247,6 +248,25 @@ static inline unsigned long __ffs64(u64 word) } /** + * fns - find N'th set bit in a word + * @word: The word to search + * @n: Bit to find + */ +static inline unsigned long fns(unsigned long word, unsigned int n) +{ + unsigned int bit; + + while (word) { + bit = __ffs(word); + if (n-- == 0) + return bit; + __clear_bit(bit, &word); + } + + return BITS_PER_LONG; +} + +/** * assign_bit - Assign value to a bit in memory * @nr: the bit to set * @addr: the address to start counting from @@ -327,10 +347,10 @@ static __always_inline void __assign_bit(long nr, volatile unsigned long *addr, const typeof(*(ptr)) mask__ = (mask), bits__ = (bits); \ typeof(*(ptr)) old__, new__; \ \ + old__ = READ_ONCE(*(ptr)); \ do { \ - old__ = READ_ONCE(*(ptr)); \ new__ = (old__ & ~mask__) | bits__; \ - } while (cmpxchg(ptr, old__, new__) != old__); \ + } while (!try_cmpxchg(ptr, &old__, new__)); \ \ old__; \ }) @@ -342,11 +362,12 @@ static __always_inline void __assign_bit(long nr, volatile unsigned long *addr, const typeof(*(ptr)) clear__ = (clear), test__ = (test);\ typeof(*(ptr)) old__, new__; \ \ + old__ = READ_ONCE(*(ptr)); \ do { \ - old__ = READ_ONCE(*(ptr)); \ + if (old__ & test__) \ + break; \ new__ = old__ & ~clear__; \ - } while (!(old__ & test__) && \ - cmpxchg(ptr, old__, new__) != old__); \ + } while (!try_cmpxchg(ptr, &old__, new__)); \ \ !(old__ & test__); \ }) |