cregit-Linux how code gets into the kernel

Release 4.7 include/asm-generic/bitops/lock.h

#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_atomic();        \
        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
 *
 * A weaker form of clear_bit_unlock() as used by __bit_lock_unlock(). If all
 * the bits in the word are protected by this lock some archs can use weaker
 * ops to safely unlock.
 *
 * See for example x86's implementation.
 */

#define __clear_bit_unlock(nr, addr)	\
do {                                    \
        smp_mb__before_atomic();        \
        clear_bit(nr, addr);            \
} while (0)

#endif /* _ASM_GENERIC_BITOPS_LOCK_H_ */


Overall Contributors

PersonTokensPropCommitsCommitProp
nick pigginnick piggin3892.68%133.33%
peter zijlstrapeter zijlstra37.32%266.67%
Total41100.00%3100.00%
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