1 #ifndef _ASM_GENERIC_BITOPS_LOCK_H_ 2 #define _ASM_GENERIC_BITOPS_LOCK_H_ 3 4 /** 5 * test_and_set_bit_lock - Set a bit and return its old value, for lock 6 * @nr: Bit to set 7 * @addr: Address to count from 8 * 9 * This operation is atomic and provides acquire barrier semantics. 10 * It can be used to implement bit locks. 11 */ 12 #define test_and_set_bit_lock(nr, addr) test_and_set_bit(nr, addr) 13 14 /** 15 * clear_bit_unlock - Clear a bit in memory, for unlock 16 * @nr: the bit to set 17 * @addr: the address to start counting from 18 * 19 * This operation is atomic and provides release barrier semantics. 20 */ 21 #define clear_bit_unlock(nr, addr) \ 22 do { \ 23 smp_mb__before_atomic(); \ 24 clear_bit(nr, addr); \ 25 } while (0) 26 27 /** 28 * __clear_bit_unlock - Clear a bit in memory, for unlock 29 * @nr: the bit to set 30 * @addr: the address to start counting from 31 * 32 * A weaker form of clear_bit_unlock() as used by __bit_lock_unlock(). If all 33 * the bits in the word are protected by this lock some archs can use weaker 34 * ops to safely unlock. 35 * 36 * See for example x86's implementation. 37 */ 38 #define __clear_bit_unlock(nr, addr) \ 39 do { \ 40 smp_mb__before_atomic(); \ 41 clear_bit(nr, addr); \ 42 } while (0) 43 44 #endif /* _ASM_GENERIC_BITOPS_LOCK_H_ */ 45 46