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 psb_csync()     asm volatile("hint #17" : : : "memory")
  35
  36 #define mb()            dsb(sy)
  37 #define rmb()           dsb(ld)
  38 #define wmb()           dsb(st)
  39
  40 #define dma_rmb()       dmb(oshld)
  41 #define dma_wmb()       dmb(oshst)
  42
  43 #define __smp_mb()      dmb(ish)
  44 #define __smp_rmb()     dmb(ishld)
  45 #define __smp_wmb()     dmb(ishst)
  46
  47 #define __smp_store_release(p, v)                                       \
  48 do {                                                                    \
  49         union { typeof(*p) __val; char __c[1]; } __u =                  \
  50                 { .__val = (__force typeof(*p)) (v) };                  \
  51         compiletime_assert_atomic_type(*p);                             \
  52         switch (sizeof(*p)) {                                           \
  53         case 1:                                                         \
  54                 asm volatile ("stlrb %w1, %0"                           \
  55                                 : "=Q" (*p)                             \
  56                                 : "r" (*(__u8 *)__u.__c)                \
  57                                 : "memory");                            \
  58                 break;                                                  \
  59         case 2:                                                         \
  60                 asm volatile ("stlrh %w1, %0"                           \
  61                                 : "=Q" (*p)                             \
  62                                 : "r" (*(__u16 *)__u.__c)               \
  63                                 : "memory");                            \
  64                 break;                                                  \
  65         case 4:                                                         \
  66                 asm volatile ("stlr %w1, %0"                            \
  67                                 : "=Q" (*p)                             \
  68                                 : "r" (*(__u32 *)__u.__c)               \
  69                                 : "memory");                            \
  70                 break;                                                  \
  71         case 8:                                                         \
  72                 asm volatile ("stlr %1, %0"                             \
  73                                 : "=Q" (*p)                             \
  74                                 : "r" (*(__u64 *)__u.__c)               \
  75                                 : "memory");                            \
  76                 break;                                                  \
  77         }                                                               \
  78 } while (0)
  79
  80 #define __smp_load_acquire(p)                                           \
  81 ({                                                                      \
  82         union { typeof(*p) __val; char __c[1]; } __u;                   \
  83         compiletime_assert_atomic_type(*p);                             \
  84         switch (sizeof(*p)) {                                           \
  85         case 1:                                                         \
  86                 asm volatile ("ldarb %w0, %1"                           \
  87                         : "=r" (*(__u8 *)__u.__c)                       \
  88                         : "Q" (*p) : "memory");                         \
  89                 break;                                                  \
  90         case 2:                                                         \
  91                 asm volatile ("ldarh %w0, %1"                           \
  92                         : "=r" (*(__u16 *)__u.__c)                      \
  93                         : "Q" (*p) : "memory");                         \
  94                 break;                                                  \
  95         case 4:                                                         \
  96                 asm volatile ("ldar %w0, %1"                            \
  97                         : "=r" (*(__u32 *)__u.__c)                      \
  98                         : "Q" (*p) : "memory");                         \
  99                 break;                                                  \
 100         case 8:                                                         \
 101                 asm volatile ("ldar %0, %1"                             \
 102                         : "=r" (*(__u64 *)__u.__c)                      \
 103                         : "Q" (*p) : "memory");                         \
 104                 break;                                                  \
 105         }                                                               \
 106         __u.__val;                                                      \
 107 })
 108
 109 #define smp_cond_load_acquire(ptr, cond_expr)                           \
 110 ({                                                                      \
 111         typeof(ptr) __PTR = (ptr);                                      \
 112         typeof(*ptr) VAL;                                               \
 113         for (;;) {                                                      \
 114                 VAL = smp_load_acquire(__PTR);                          \
 115                 if (cond_expr)                                          \
 116                         break;                                          \
 117                 __cmpwait_relaxed(__PTR, VAL);                          \
 118         }                                                               \
 119         VAL;                                                            \
 120 })
 121
 122 #include <asm-generic/barrier.h>
 123
 124 #endif  /* __ASSEMBLY__ */
 125
 126 #endif  /* __ASM_BARRIER_H */