| rjw | 1f88458 | 2022-01-06 17:20:42 +0800 | [diff] [blame^] | 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. |
| 11 | * It can be used to implement bit locks. |
| 12 | */ |
| 13 | #define test_and_set_bit_lock(nr, addr) test_and_set_bit(nr, addr) |
| 14 | |
| 15 | /** |
| 16 | * clear_bit_unlock - Clear a bit in memory, for unlock |
| 17 | * @nr: the bit to set |
| 18 | * @addr: the address to start counting from |
| 19 | * |
| 20 | * This operation is atomic and provides release barrier semantics. |
| 21 | */ |
| 22 | #define clear_bit_unlock(nr, addr) \ |
| 23 | do { \ |
| 24 | smp_mb__before_atomic(); \ |
| 25 | clear_bit(nr, addr); \ |
| 26 | } while (0) |
| 27 | |
| 28 | /** |
| 29 | * __clear_bit_unlock - Clear a bit in memory, for unlock |
| 30 | * @nr: the bit to set |
| 31 | * @addr: the address to start counting from |
| 32 | * |
| 33 | * A weaker form of clear_bit_unlock() as used by __bit_lock_unlock(). If all |
| 34 | * the bits in the word are protected by this lock some archs can use weaker |
| 35 | * ops to safely unlock. |
| 36 | * |
| 37 | * See for example x86's implementation. |
| 38 | */ |
| 39 | #define __clear_bit_unlock(nr, addr) \ |
| 40 | do { \ |
| 41 | smp_mb__before_atomic(); \ |
| 42 | clear_bit(nr, addr); \ |
| 43 | } while (0) |
| 44 | |
| 45 | #endif /* _ASM_GENERIC_BITOPS_LOCK_H_ */ |
| 46 | |