LXR linux/arch/arm/include/asm/sync

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef __ASM_SYNC_BITOPS_H__
   3#define __ASM_SYNC_BITOPS_H__
   4
   5#include <asm/bitops.h>
   6
   7/* sync_bitops functions are equivalent to the SMP implementation of the
   8 * original functions, independently from CONFIG_SMP being defined.
   9 *
  10 * We need them because _set_bit etc are not SMP safe if !CONFIG_SMP. But
  11 * under Xen you might be communicating with a completely external entity
  12 * who might be on another CPU (e.g. two uniprocessor guests communicating
  13 * via event channels and grant tables). So we need a variant of the bit
  14 * ops which are SMP safe even on a UP kernel.
  15 */
  16
  17#define sync_set_bit(nr, p)             _set_bit(nr, p)
  18#define sync_clear_bit(nr, p)           _clear_bit(nr, p)
  19#define sync_change_bit(nr, p)          _change_bit(nr, p)
  20#define sync_test_and_set_bit(nr, p)    _test_and_set_bit(nr, p)
  21#define sync_test_and_clear_bit(nr, p)  _test_and_clear_bit(nr, p)
  22#define sync_test_and_change_bit(nr, p) _test_and_change_bit(nr, p)
  23#define sync_test_bit(nr, addr)         test_bit(nr, addr)
  24#define sync_cmpxchg                    cmpxchg
  25
  26
  27#endif
  28