LXR linux/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)                                                   \
  20static inline void arch_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)                                            \
  35static inline int arch_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)                                             \
  53static inline int arch_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
  73ATOMIC_OPS(add)
  74ATOMIC_OPS(sub)
  75
  76#undef ATOMIC_OPS
  77#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_FETCH_OP(op)
  78
  79ATOMIC_OPS(and)
  80ATOMIC_OPS(or)
  81ATOMIC_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 */
  89