46 lines
1.2 KiB
C
46 lines
1.2 KiB
C
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#ifndef _ASM_GENERIC_BITOPS_LOCK_H_
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#define _ASM_GENERIC_BITOPS_LOCK_H_
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/**
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* test_and_set_bit_lock - Set a bit and return its old value, for lock
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* @nr: Bit to set
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* @addr: Address to count from
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*
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* This operation is atomic and provides acquire barrier semantics.
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* It can be used to implement bit locks.
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*/
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#define test_and_set_bit_lock(nr, addr) test_and_set_bit(nr, addr)
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/**
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* clear_bit_unlock - Clear a bit in memory, for unlock
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* @nr: the bit to set
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* @addr: the address to start counting from
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*
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* This operation is atomic and provides release barrier semantics.
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*/
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#define clear_bit_unlock(nr, addr) \
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do { \
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smp_mb__before_atomic(); \
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clear_bit(nr, addr); \
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} while (0)
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/**
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* __clear_bit_unlock - Clear a bit in memory, for unlock
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* @nr: the bit to set
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* @addr: the address to start counting from
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*
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* A weaker form of clear_bit_unlock() as used by __bit_lock_unlock(). If all
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* the bits in the word are protected by this lock some archs can use weaker
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* ops to safely unlock.
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*
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* See for example x86's implementation.
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*/
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#define __clear_bit_unlock(nr, addr) \
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do { \
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smp_mb__before_atomic(); \
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clear_bit(nr, addr); \
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} while (0)
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#endif /* _ASM_GENERIC_BITOPS_LOCK_H_ */
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