1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_GENERIC_BITOPS_LOCK_H_ 3 #define _ASM_GENERIC_BITOPS_LOCK_H_ 4 5 /** 6 * test_and_set_bit_lock - Set a bit and return its old value, for lock 7 * @nr: Bit to set 8 * @addr: Address to count from 9 * 10 * This operation is atomic and provides acquire barrier semantics if 11 * the returned value is 0. 12 * It can be used to implement bit locks. 13 */ 14 #define test_and_set_bit_lock(nr, addr) test_and_set_bit(nr, addr) 15 16 /** 17 * clear_bit_unlock - Clear a bit in memory, for unlock 18 * @nr: the bit to set 19 * @addr: the address to start counting from 20 * 21 * This operation is atomic and provides release barrier semantics. 22 */ 23 #define clear_bit_unlock(nr, addr) \ 24 do { \ 25 smp_mb__before_atomic(); \ 26 clear_bit(nr, addr); \ 27 } while (0) 28 29 /** 30 * __clear_bit_unlock - Clear a bit in memory, for unlock 31 * @nr: the bit to set 32 * @addr: the address to start counting from 33 * 34 * A weaker form of clear_bit_unlock() as used by __bit_lock_unlock(). If all 35 * the bits in the word are protected by this lock some archs can use weaker 36 * ops to safely unlock. 37 * 38 * See for example x86's implementation. 39 */ 40 #define __clear_bit_unlock(nr, addr) \ 41 do { \ 42 smp_mb__before_atomic(); \ 43 clear_bit(nr, addr); \ 44 } while (0) 45 46 #endif /* _ASM_GENERIC_BITOPS_LOCK_H_ */ 47 48