Something went wrong. Try again.
Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Something went wrong. Try again.
2.2 kB · 82 lines
C
at master
1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283/* SPDX-License-Identifier: GPL-2.0 */#ifndef _ASM_GENERIC_BITOPS_LOCK_H_#define _ASM_GENERIC_BITOPS_LOCK_H_
#include <linux/atomic.h>#include <linux/compiler.h>#include <asm/barrier.h>
/** * arch_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 if * the returned value is 0. * It can be used to implement bit locks. */static __always_inline intarch_test_and_set_bit_lock(unsigned int nr, volatile unsigned long *addr){ long old; unsigned long mask = BIT_MASK(nr);
addr += BIT_WORD(nr); if (READ_ONCE(*addr) & mask) return 1;
old = raw_atomic_long_fetch_or_acquire(mask, (atomic_long_t *)addr); return !!(old & mask);}
/** * arch_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. */static __always_inline voidarch_clear_bit_unlock(unsigned int nr, volatile unsigned long *addr){ addr += BIT_WORD(nr); raw_atomic_long_fetch_andnot_release(BIT_MASK(nr), (atomic_long_t *)addr);}
/** * arch___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. */static inline voidarch___clear_bit_unlock(unsigned int nr, volatile unsigned long *addr){ unsigned long old;
addr += BIT_WORD(nr); old = READ_ONCE(*addr); old &= ~BIT_MASK(nr); raw_atomic_long_set_release((atomic_long_t *)addr, old);}
#ifndef arch_xor_unlock_is_negative_bytestatic inline bool arch_xor_unlock_is_negative_byte(unsigned long mask, volatile unsigned long *p){ long old;
old = raw_atomic_long_fetch_xor_release(mask, (atomic_long_t *)p); return !!(old & BIT(7));}#endif
#include <asm-generic/bitops/instrumented-lock.h>
#endif /* _ASM_GENERIC_BITOPS_LOCK_H_ */