kernel/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 #define dma_rmb()       dmb(oshld)
  36 #define dma_wmb()       dmb(oshst)
  37
  38 #ifndef CONFIG_SMP
  39 #define smp_mb()        barrier()
  40 #define smp_rmb()       barrier()
  41 #define smp_wmb()       barrier()
  42
  43 #define smp_store_release(p, v)                                         \
  44 do {                                                                    \
  45         compiletime_assert_atomic_type(*p);                             \
  46         barrier();                                                      \
  47         ACCESS_ONCE(*p) = (v);                                          \
  48 } while (0)
  49
  50 #define smp_load_acquire(p)                                             \
  51 ({                                                                      \
  52         typeof(*p) ___p1 = ACCESS_ONCE(*p);                             \
  53         compiletime_assert_atomic_type(*p);                             \
  54         barrier();                                                      \
  55         ___p1;                                                          \
  56 })
  57
  58 #else
  59
  60 #define smp_mb()        dmb(ish)
  61 #define smp_rmb()       dmb(ishld)
  62 #define smp_wmb()       dmb(ishst)
  63
  64 #define smp_store_release(p, v)                                         \
  65 do {                                                                    \
  66         compiletime_assert_atomic_type(*p);                             \
  67         switch (sizeof(*p)) {                                           \
  68         case 1:                                                         \
  69                 asm volatile ("stlrb %w1, %0"                           \
  70                                 : "=Q" (*p) : "r" (v) : "memory");      \
  71                 break;                                                  \
  72         case 2:                                                         \
  73                 asm volatile ("stlrh %w1, %0"                           \
  74                                 : "=Q" (*p) : "r" (v) : "memory");      \
  75                 break;                                                  \
  76         case 4:                                                         \
  77                 asm volatile ("stlr %w1, %0"                            \
  78                                 : "=Q" (*p) : "r" (v) : "memory");      \
  79                 break;                                                  \
  80         case 8:                                                         \
  81                 asm volatile ("stlr %1, %0"                             \
  82                                 : "=Q" (*p) : "r" (v) : "memory");      \
  83                 break;                                                  \
  84         }                                                               \
  85 } while (0)
  86
  87 #define smp_load_acquire(p)                                             \
  88 ({                                                                      \
  89         typeof(*p) ___p1;                                               \
  90         compiletime_assert_atomic_type(*p);                             \
  91         switch (sizeof(*p)) {                                           \
  92         case 1:                                                         \
  93                 asm volatile ("ldarb %w0, %1"                           \
  94                         : "=r" (___p1) : "Q" (*p) : "memory");          \
  95                 break;                                                  \
  96         case 2:                                                         \
  97                 asm volatile ("ldarh %w0, %1"                           \
  98                         : "=r" (___p1) : "Q" (*p) : "memory");          \
  99                 break;                                                  \
 100         case 4:                                                         \
 101                 asm volatile ("ldar %w0, %1"                            \
 102                         : "=r" (___p1) : "Q" (*p) : "memory");          \
 103                 break;                                                  \
 104         case 8:                                                         \
 105                 asm volatile ("ldar %0, %1"                             \
 106                         : "=r" (___p1) : "Q" (*p) : "memory");          \
 107                 break;                                                  \
 108         }                                                               \
 109         ___p1;                                                          \
 110 })
 111
 112 #endif
 113
 114 #define read_barrier_depends()          do { } while(0)
 115 #define smp_read_barrier_depends()      do { } while(0)
 116
 117 #define set_mb(var, value)      do { var = value; smp_mb(); } while (0)
 118 #define nop()           asm volatile("nop");
 119
 120 #define smp_mb__before_atomic() smp_mb()
 121 #define smp_mb__after_atomic()  smp_mb()
 122
 123 #endif  /* __ASSEMBLY__ */
 124
 125 #endif  /* __ASM_BARRIER_H */