root/arch/arm64/include/asm/sync_bitops.h

INCLUDED FROM

   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