arch/arm64/include/asm/barrier.h

   1 /*
   2  * Based on arch/arm/include/asm/barrier.h
   3  *
   4  * Copyright (C) 2012 ARM Ltd.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18 #ifndef __ASM_BARRIER_H
  19 #define __ASM_BARRIER_H
  20
  21 #ifndef __ASSEMBLY__
  22
  23 #define sev()           asm volatile("sev" : : : "memory")
  24 #define wfe()           asm volatile("wfe" : : : "memory")
  25 #define wfi()           asm volatile("wfi" : : : "memory")
  26
  27 #define isb()           asm volatile("isb" : : : "memory")
  28 #define dmb(opt)        asm volatile("dmb " #opt : : : "memory")
  29 #define dsb(opt)        asm volatile("dsb " #opt : : : "memory")
  30
  31 #define mb()            dsb(sy)
  32 #define rmb()           dsb(ld)
  33 #define wmb()           dsb(st)
  34
  35 #ifndef CONFIG_SMP
  36 #define smp_mb()        barrier()
  37 #define smp_rmb()       barrier()
  38 #define smp_wmb()       barrier()
  39
  40 #define smp_store_release(p, v)                                         \
  41 do {                                                                    \
  42         compiletime_assert_atomic_type(*p);                             \
  43         barrier();                                                      \
  44         ACCESS_ONCE(*p) = (v);                                          \
  45 } while (0)
  46
  47 #define smp_load_acquire(p)                                             \
  48 ({                                                                      \
  49         typeof(*p) ___p1 = ACCESS_ONCE(*p);                             \
  50         compiletime_assert_atomic_type(*p);                             \
  51         barrier();                                                      \
  52         ___p1;                                                          \
  53 })
  54
  55 #else
  56
  57 #define smp_mb()        dmb(ish)
  58 #define smp_rmb()       dmb(ishld)
  59 #define smp_wmb()       dmb(ishst)
  60
  61 #define smp_store_release(p, v)                                         \
  62 do {                                                                    \
  63         compiletime_assert_atomic_type(*p);                             \
  64         switch (sizeof(*p)) {                                           \
  65         case 4:                                                         \
  66                 asm volatile ("stlr %w1, %0"                            \
  67                                 : "=Q" (*p) : "r" (v) : "memory");      \
  68                 break;                                                  \
  69         case 8:                                                         \
  70                 asm volatile ("stlr %1, %0"                             \
  71                                 : "=Q" (*p) : "r" (v) : "memory");      \
  72                 break;                                                  \
  73         }                                                               \
  74 } while (0)
  75
  76 #define smp_load_acquire(p)                                             \
  77 ({                                                                      \
  78         typeof(*p) ___p1;                                               \
  79         compiletime_assert_atomic_type(*p);                             \
  80         switch (sizeof(*p)) {                                           \
  81         case 4:                                                         \
  82                 asm volatile ("ldar %w0, %1"                            \
  83                         : "=r" (___p1) : "Q" (*p) : "memory");          \
  84                 break;                                                  \
  85         case 8:                                                         \
  86                 asm volatile ("ldar %0, %1"                             \
  87                         : "=r" (___p1) : "Q" (*p) : "memory");          \
  88                 break;                                                  \
  89         }                                                               \
  90         ___p1;                                                          \
  91 })
  92
  93 #endif
  94
  95 #define read_barrier_depends()          do { } while(0)
  96 #define smp_read_barrier_depends()      do { } while(0)
  97
  98 #define set_mb(var, value)      do { var = value; smp_mb(); } while (0)
  99 #define nop()           asm volatile("nop");
 100
 101 #define smp_mb__before_atomic() smp_mb()
 102 #define smp_mb__after_atomic()  smp_mb()
 103
 104 #endif  /* __ASSEMBLY__ */
 105
 106 #endif  /* __ASM_BARRIER_H */