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author | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
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committer | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
commit | 871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch) | |
tree | 8718f573808810c2a1e8cb8fb6ac469093ca2784 /include/asm-generic/bitops/lock.h | |
parent | 9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff) | |
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Moved, renamed, and deleted files
The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.
Diffstat (limited to 'include/asm-generic/bitops/lock.h')
-rw-r--r-- | include/asm-generic/bitops/lock.h | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/include/asm-generic/bitops/lock.h b/include/asm-generic/bitops/lock.h new file mode 100644 index 00000000..308a9e22 --- /dev/null +++ b/include/asm-generic/bitops/lock.h @@ -0,0 +1,45 @@ +#ifndef _ASM_GENERIC_BITOPS_LOCK_H_ +#define _ASM_GENERIC_BITOPS_LOCK_H_ + +/** + * test_and_set_bit_lock - Set a bit and return its old value, for lock + * @nr: Bit to set + * @addr: Address to count from + * + * This operation is atomic and provides acquire barrier semantics. + * It can be used to implement bit locks. + */ +#define test_and_set_bit_lock(nr, addr) test_and_set_bit(nr, addr) + +/** + * clear_bit_unlock - Clear a bit in memory, for unlock + * @nr: the bit to set + * @addr: the address to start counting from + * + * This operation is atomic and provides release barrier semantics. + */ +#define clear_bit_unlock(nr, addr) \ +do { \ + smp_mb__before_clear_bit(); \ + clear_bit(nr, addr); \ +} while (0) + +/** + * __clear_bit_unlock - Clear a bit in memory, for unlock + * @nr: the bit to set + * @addr: the address to start counting from + * + * This operation is like clear_bit_unlock, however it is not atomic. + * It does provide release barrier semantics so it can be used to unlock + * a bit lock, however it would only be used if no other CPU can modify + * any bits in the memory until the lock is released (a good example is + * if the bit lock itself protects access to the other bits in the word). + */ +#define __clear_bit_unlock(nr, addr) \ +do { \ + smp_mb(); \ + __clear_bit(nr, addr); \ +} while (0) + +#endif /* _ASM_GENERIC_BITOPS_LOCK_H_ */ + |