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 __nops(n)       ".rept  " #n "\nnop\n.endr\n"
  24 #define nops(n)         asm volatile(__nops(n))
  25
  26 #define sev()           asm volatile("sev" : : : "memory")
  27 #define wfe()           asm volatile("wfe" : : : "memory")
  28 #define wfi()           asm volatile("wfi" : : : "memory")
  29
  30 #define isb()           asm volatile("isb" : : : "memory")
  31 #define dmb(opt)        asm volatile("dmb " #opt : : : "memory")
  32 #define dsb(opt)        asm volatile("dsb " #opt : : : "memory")
  33
  34 #define mb()            dsb(sy)
  35 #define rmb()           dsb(ld)
  36 #define wmb()           dsb(st)
  37
  38 #define dma_rmb()       dmb(oshld)
  39 #define dma_wmb()       dmb(oshst)
  40
  41 #define __smp_mb()      dmb(ish)
  42 #define __smp_rmb()     dmb(ishld)
  43 #define __smp_wmb()     dmb(ishst)
  44
  45 #define __smp_store_release(p, v)                                               \
  46 do {                                                                    \
  47         compiletime_assert_atomic_type(*p);                             \
  48         switch (sizeof(*p)) {                                           \
  49         case 1:                                                         \
  50                 asm volatile ("stlrb %w1, %0"                           \
  51                                 : "=Q" (*p) : "r" (v) : "memory");      \
  52                 break;                                                  \
  53         case 2:                                                         \
  54                 asm volatile ("stlrh %w1, %0"                           \
  55                                 : "=Q" (*p) : "r" (v) : "memory");      \
  56                 break;                                                  \
  57         case 4:                                                         \
  58                 asm volatile ("stlr %w1, %0"                            \
  59                                 : "=Q" (*p) : "r" (v) : "memory");      \
  60                 break;                                                  \
  61         case 8:                                                         \
  62                 asm volatile ("stlr %1, %0"                             \
  63                                 : "=Q" (*p) : "r" (v) : "memory");      \
  64                 break;                                                  \
  65         }                                                               \
  66 } while (0)
  67
  68 #define __smp_load_acquire(p)                                           \
  69 ({                                                                      \
  70         union { typeof(*p) __val; char __c[1]; } __u;                   \
  71         compiletime_assert_atomic_type(*p);                             \
  72         switch (sizeof(*p)) {                                           \
  73         case 1:                                                         \
  74                 asm volatile ("ldarb %w0, %1"                           \
  75                         : "=r" (*(__u8 *)__u.__c)                       \
  76                         : "Q" (*p) : "memory");                         \
  77                 break;                                                  \
  78         case 2:                                                         \
  79                 asm volatile ("ldarh %w0, %1"                           \
  80                         : "=r" (*(__u16 *)__u.__c)                      \
  81                         : "Q" (*p) : "memory");                         \
  82                 break;                                                  \
  83         case 4:                                                         \
  84                 asm volatile ("ldar %w0, %1"                            \
  85                         : "=r" (*(__u32 *)__u.__c)                      \
  86                         : "Q" (*p) : "memory");                         \
  87                 break;                                                  \
  88         case 8:                                                         \
  89                 asm volatile ("ldar %0, %1"                             \
  90                         : "=r" (*(__u64 *)__u.__c)                      \
  91                         : "Q" (*p) : "memory");                         \
  92                 break;                                                  \
  93         }                                                               \
  94         __u.__val;                                                      \
  95 })
  96
  97 #define smp_cond_load_acquire(ptr, cond_expr)                           \
  98 ({                                                                      \
  99         typeof(ptr) __PTR = (ptr);                                      \
 100         typeof(*ptr) VAL;                                               \
 101         for (;;) {                                                      \
 102                 VAL = smp_load_acquire(__PTR);                          \
 103                 if (cond_expr)                                          \
 104                         break;                                          \
 105                 __cmpwait_relaxed(__PTR, VAL);                          \
 106         }                                                               \
 107         VAL;                                                            \
 108 })
 109
 110 #include <asm-generic/barrier.h>
 111
 112 #endif  /* __ASSEMBLY__ */
 113
 114 #endif  /* __ASM_BARRIER_H */