LXR linux/include/asm-generic/bitops/atomic.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _ASM_GENERIC_BITOPS_ATOMIC_H_
   3#define _ASM_GENERIC_BITOPS_ATOMIC_H_
   4
   5#include <linux/atomic.h>
   6#include <linux/compiler.h>
   7#include <asm/barrier.h>
   8
   9/*
  10 * Implementation of atomic bitops using atomic-fetch ops.
  11 * See Documentation/atomic_bitops.txt for details.
  12 */
  13
  14static __always_inline void
  15arch_set_bit(unsigned int nr, volatile unsigned long *p)
  16{
  17        p += BIT_WORD(nr);
  18        arch_atomic_long_or(BIT_MASK(nr), (atomic_long_t *)p);
  19}
  20
  21static __always_inline void
  22arch_clear_bit(unsigned int nr, volatile unsigned long *p)
  23{
  24        p += BIT_WORD(nr);
  25        arch_atomic_long_andnot(BIT_MASK(nr), (atomic_long_t *)p);
  26}
  27
  28static __always_inline void
  29arch_change_bit(unsigned int nr, volatile unsigned long *p)
  30{
  31        p += BIT_WORD(nr);
  32        arch_atomic_long_xor(BIT_MASK(nr), (atomic_long_t *)p);
  33}
  34
  35static __always_inline int
  36arch_test_and_set_bit(unsigned int nr, volatile unsigned long *p)
  37{
  38        long old;
  39        unsigned long mask = BIT_MASK(nr);
  40
  41        p += BIT_WORD(nr);
  42        if (READ_ONCE(*p) & mask)
  43                return 1;
  44
  45        old = arch_atomic_long_fetch_or(mask, (atomic_long_t *)p);
  46        return !!(old & mask);
  47}
  48
  49static __always_inline int
  50arch_test_and_clear_bit(unsigned int nr, volatile unsigned long *p)
  51{
  52        long old;
  53        unsigned long mask = BIT_MASK(nr);
  54
  55        p += BIT_WORD(nr);
  56        if (!(READ_ONCE(*p) & mask))
  57                return 0;
  58
  59        old = arch_atomic_long_fetch_andnot(mask, (atomic_long_t *)p);
  60        return !!(old & mask);
  61}
  62
  63static __always_inline int
  64arch_test_and_change_bit(unsigned int nr, volatile unsigned long *p)
  65{
  66        long old;
  67        unsigned long mask = BIT_MASK(nr);
  68
  69        p += BIT_WORD(nr);
  70        old = arch_atomic_long_fetch_xor(mask, (atomic_long_t *)p);
  71        return !!(old & mask);
  72}
  73
  74#include <asm-generic/bitops/instrumented-atomic.h>
  75
  76#endif /* _ASM_GENERIC_BITOPS_ATOMIC_H */
  77