LXR linux/arch/arm64/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#include <asm/cmpxchg.h>
   7
   8/* sync_bitops functions are equivalent to the SMP implementation of the
   9 * original functions, independently from CONFIG_SMP being defined.
  10 *
  11 * We need them because _set_bit etc are not SMP safe if !CONFIG_SMP. But
  12 * under Xen you might be communicating with a completely external entity
  13 * who might be on another CPU (e.g. two uniprocessor guests communicating
  14 * via event channels and grant tables). So we need a variant of the bit
  15 * ops which are SMP safe even on a UP kernel.
  16 */
  17
  18#define sync_set_bit(nr, p)                     set_bit(nr, p)
  19#define sync_clear_bit(nr, p)                   clear_bit(nr, p)
  20#define sync_change_bit(nr, p)                  change_bit(nr, p)
  21#define sync_test_and_set_bit(nr, p)            test_and_set_bit(nr, p)
  22#define sync_test_and_clear_bit(nr, p)          test_and_clear_bit(nr, p)
  23#define sync_test_and_change_bit(nr, p)         test_and_change_bit(nr, p)
  24#define sync_test_bit(nr, addr)                 test_bit(nr, addr)
  25#define arch_sync_cmpxchg                       arch_cmpxchg
  26
  27#endif
  28