arch/sh/include/asm/atomic-llsc.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __ASM_SH_ATOMIC_LLSC_H
   3 #define __ASM_SH_ATOMIC_LLSC_H
   4
   5 /*
   6  * SH-4A note:
   7  *
   8  * We basically get atomic_xxx_return() for free compared with
   9  * atomic_xxx(). movli.l/movco.l require r0 due to the instruction
  10  * encoding, so the retval is automatically set without having to
  11  * do any special work.
  12  */
  13 /*
  14  * To get proper branch prediction for the main line, we must branch
  15  * forward to code at the end of this object's .text section, then
  16  * branch back to restart the operation.
  17  */
  18
  19 #define ATOMIC_OP(op)                                                   \
  20 static inline void atomic_##op(int i, atomic_t *v)                      \
  21 {                                                                       \
  22         unsigned long tmp;                                              \
  23                                                                         \
  24         __asm__ __volatile__ (                                          \
  25 "1:     movli.l @%2, %0         ! atomic_" #op "\n"                     \
  26 "       " #op " %1, %0                          \n"                     \
  27 "       movco.l %0, @%2                         \n"                     \
  28 "       bf      1b                              \n"                     \
  29         : "=&z" (tmp)                                                   \
  30         : "r" (i), "r" (&v->counter)                                    \
  31         : "t");                                                         \
  32 }
  33
  34 #define ATOMIC_OP_RETURN(op)                                            \
  35 static inline int atomic_##op##_return(int i, atomic_t *v)              \
  36 {                                                                       \
  37         unsigned long temp;                                             \
  38                                                                         \
  39         __asm__ __volatile__ (                                          \
  40 "1:     movli.l @%2, %0         ! atomic_" #op "_return \n"             \
  41 "       " #op " %1, %0                                  \n"             \
  42 "       movco.l %0, @%2                                 \n"             \
  43 "       bf      1b                                      \n"             \
  44 "       synco                                           \n"             \
  45         : "=&z" (temp)                                                  \
  46         : "r" (i), "r" (&v->counter)                                    \
  47         : "t");                                                         \
  48                                                                         \
  49         return temp;                                                    \
  50 }
  51
  52 #define ATOMIC_FETCH_OP(op)                                             \
  53 static inline int atomic_fetch_##op(int i, atomic_t *v)                 \
  54 {                                                                       \
  55         unsigned long res, temp;                                        \
  56                                                                         \
  57         __asm__ __volatile__ (                                          \
  58 "1:     movli.l @%3, %0         ! atomic_fetch_" #op "  \n"             \
  59 "       mov %0, %1                                      \n"             \
  60 "       " #op " %2, %0                                  \n"             \
  61 "       movco.l %0, @%3                                 \n"             \
  62 "       bf      1b                                      \n"             \
  63 "       synco                                           \n"             \
  64         : "=&z" (temp), "=&r" (res)                                     \
  65         : "r" (i), "r" (&v->counter)                                    \
  66         : "t");                                                         \
  67                                                                         \
  68         return res;                                                     \
  69 }
  70
  71 #define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op) ATOMIC_FETCH_OP(op)
  72
  73 ATOMIC_OPS(add)
  74 ATOMIC_OPS(sub)
  75
  76 #undef ATOMIC_OPS
  77 #define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_FETCH_OP(op)
  78
  79 ATOMIC_OPS(and)
  80 ATOMIC_OPS(or)
  81 ATOMIC_OPS(xor)
  82
  83 #undef ATOMIC_OPS
  84 #undef ATOMIC_FETCH_OP
  85 #undef ATOMIC_OP_RETURN
  86 #undef ATOMIC_OP
  87
  88 #endif /* __ASM_SH_ATOMIC_LLSC_H */