From 21bb8af513d35c005c401706030f4eb469538d1d Mon Sep 17 00:00:00 2001 From: Alexander Lobakin Date: Fri, 24 Jun 2022 14:13:06 +0200 Subject: bitops: always define asm-generic non-atomic bitops Move generic non-atomic bitops from the asm-generic header which gets included only when there are no architecture-specific alternatives, to a separate independent file to make them always available. Almost no actual code changes, only one comment added to generic_test_bit() saying that it's an atomic operation itself and thus `volatile` must always stay there with no cast-aways. Suggested-by: Andy Shevchenko # comment Suggested-by: Marco Elver # reference to kernel-doc Signed-off-by: Alexander Lobakin Reviewed-by: Andy Shevchenko Reviewed-by: Marco Elver Signed-off-by: Yury Norov --- include/asm-generic/bitops/non-atomic.h | 110 +++----------------------------- 1 file changed, 8 insertions(+), 102 deletions(-) (limited to 'include/asm-generic/bitops/non-atomic.h') diff --git a/include/asm-generic/bitops/non-atomic.h b/include/asm-generic/bitops/non-atomic.h index 078cc68be2f1..23d3abc1e10d 100644 --- a/include/asm-generic/bitops/non-atomic.h +++ b/include/asm-generic/bitops/non-atomic.h @@ -2,121 +2,27 @@ #ifndef _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ #define _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ -#include +#include -/** - * arch___set_bit - Set a bit in memory - * @nr: the bit to set - * @addr: the address to start counting from - * - * Unlike set_bit(), this function is non-atomic and may be reordered. - * If it's called on the same region of memory simultaneously, the effect - * may be that only one operation succeeds. - */ -static __always_inline void -arch___set_bit(unsigned int nr, volatile unsigned long *addr) -{ - unsigned long mask = BIT_MASK(nr); - unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); - - *p |= mask; -} +#define arch___set_bit generic___set_bit #define __set_bit arch___set_bit -static __always_inline void -arch___clear_bit(unsigned int nr, volatile unsigned long *addr) -{ - unsigned long mask = BIT_MASK(nr); - unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); - - *p &= ~mask; -} +#define arch___clear_bit generic___clear_bit #define __clear_bit arch___clear_bit -/** - * arch___change_bit - Toggle a bit in memory - * @nr: the bit to change - * @addr: the address to start counting from - * - * Unlike change_bit(), this function is non-atomic and may be reordered. - * If it's called on the same region of memory simultaneously, the effect - * may be that only one operation succeeds. - */ -static __always_inline -void arch___change_bit(unsigned int nr, volatile unsigned long *addr) -{ - unsigned long mask = BIT_MASK(nr); - unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); - - *p ^= mask; -} +#define arch___change_bit generic___change_bit #define __change_bit arch___change_bit -/** - * arch___test_and_set_bit - Set a bit and return its old value - * @nr: Bit to set - * @addr: Address to count from - * - * This operation is non-atomic and can be reordered. - * If two examples of this operation race, one can appear to succeed - * but actually fail. You must protect multiple accesses with a lock. - */ -static __always_inline int -arch___test_and_set_bit(unsigned int nr, volatile unsigned long *addr) -{ - unsigned long mask = BIT_MASK(nr); - unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); - unsigned long old = *p; - - *p = old | mask; - return (old & mask) != 0; -} +#define arch___test_and_set_bit generic___test_and_set_bit #define __test_and_set_bit arch___test_and_set_bit -/** - * arch___test_and_clear_bit - Clear a bit and return its old value - * @nr: Bit to clear - * @addr: Address to count from - * - * This operation is non-atomic and can be reordered. - * If two examples of this operation race, one can appear to succeed - * but actually fail. You must protect multiple accesses with a lock. - */ -static __always_inline int -arch___test_and_clear_bit(unsigned int nr, volatile unsigned long *addr) -{ - unsigned long mask = BIT_MASK(nr); - unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); - unsigned long old = *p; - - *p = old & ~mask; - return (old & mask) != 0; -} +#define arch___test_and_clear_bit generic___test_and_clear_bit #define __test_and_clear_bit arch___test_and_clear_bit -/* WARNING: non atomic and it can be reordered! */ -static __always_inline int -arch___test_and_change_bit(unsigned int nr, volatile unsigned long *addr) -{ - unsigned long mask = BIT_MASK(nr); - unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); - unsigned long old = *p; - - *p = old ^ mask; - return (old & mask) != 0; -} +#define arch___test_and_change_bit generic___test_and_change_bit #define __test_and_change_bit arch___test_and_change_bit -/** - * arch_test_bit - Determine whether a bit is set - * @nr: bit number to test - * @addr: Address to start counting from - */ -static __always_inline int -arch_test_bit(unsigned int nr, const volatile unsigned long *addr) -{ - return 1UL & (addr[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG-1))); -} +#define arch_test_bit generic_test_bit #define test_bit arch_test_bit #endif /* _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ */ -- cgit v1.2.3