linux/arch/csky/include/asm/futex.h
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2
   3#ifndef __ASM_CSKY_FUTEX_H
   4#define __ASM_CSKY_FUTEX_H
   5
   6#ifndef CONFIG_SMP
   7#include <asm-generic/futex.h>
   8#else
   9#include <linux/atomic.h>
  10#include <linux/futex.h>
  11#include <linux/uaccess.h>
  12#include <linux/errno.h>
  13
  14#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg)              \
  15{                                                                       \
  16        u32 tmp;                                                        \
  17                                                                        \
  18        __atomic_pre_full_fence();                                      \
  19                                                                        \
  20        __asm__ __volatile__ (                                          \
  21        "1:     ldex.w  %[ov], %[u]                     \n"             \
  22        "       "insn"                                  \n"             \
  23        "2:     stex.w  %[t], %[u]                      \n"             \
  24        "       bez     %[t], 1b                        \n"             \
  25        "       br      4f                              \n"             \
  26        "3:     mov     %[r], %[e]                      \n"             \
  27        "4:                                             \n"             \
  28        "       .section __ex_table,\"a\"               \n"             \
  29        "       .balign 4                               \n"             \
  30        "       .long   1b, 3b                          \n"             \
  31        "       .long   2b, 3b                          \n"             \
  32        "       .previous                               \n"             \
  33        : [r] "+r" (ret), [ov] "=&r" (oldval),                          \
  34          [u] "+m" (*uaddr), [t] "=&r" (tmp)                            \
  35        : [op] "Jr" (oparg), [e] "jr" (-EFAULT)                         \
  36        : "memory");                                                    \
  37                                                                        \
  38        __atomic_post_full_fence();                                     \
  39}
  40
  41static inline int
  42arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
  43{
  44        int oldval = 0, ret = 0;
  45
  46        if (!access_ok(uaddr, sizeof(u32)))
  47                return -EFAULT;
  48
  49        switch (op) {
  50        case FUTEX_OP_SET:
  51                __futex_atomic_op("mov %[t], %[ov]",
  52                                  ret, oldval, uaddr, oparg);
  53                break;
  54        case FUTEX_OP_ADD:
  55                __futex_atomic_op("add %[t], %[ov], %[op]",
  56                                  ret, oldval, uaddr, oparg);
  57                break;
  58        case FUTEX_OP_OR:
  59                __futex_atomic_op("or %[t], %[ov], %[op]",
  60                                  ret, oldval, uaddr, oparg);
  61                break;
  62        case FUTEX_OP_ANDN:
  63                __futex_atomic_op("and %[t], %[ov], %[op]",
  64                                  ret, oldval, uaddr, ~oparg);
  65                break;
  66        case FUTEX_OP_XOR:
  67                __futex_atomic_op("xor %[t], %[ov], %[op]",
  68                                  ret, oldval, uaddr, oparg);
  69                break;
  70        default:
  71                ret = -ENOSYS;
  72        }
  73
  74        if (!ret)
  75                *oval = oldval;
  76
  77        return ret;
  78}
  79
  80
  81
  82static inline int
  83futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
  84                              u32 oldval, u32 newval)
  85{
  86        int ret = 0;
  87        u32 val, tmp;
  88
  89        if (!access_ok(uaddr, sizeof(u32)))
  90                return -EFAULT;
  91
  92        __atomic_pre_full_fence();
  93
  94        __asm__ __volatile__ (
  95        "1:     ldex.w  %[v], %[u]                      \n"
  96        "       cmpne   %[v], %[ov]                     \n"
  97        "       bt      4f                              \n"
  98        "       mov     %[t], %[nv]                     \n"
  99        "2:     stex.w  %[t], %[u]                      \n"
 100        "       bez     %[t], 1b                        \n"
 101        "       br      4f                              \n"
 102        "3:     mov     %[r], %[e]                      \n"
 103        "4:                                             \n"
 104        "       .section __ex_table,\"a\"               \n"
 105        "       .balign 4                               \n"
 106        "       .long   1b, 3b                          \n"
 107        "       .long   2b, 3b                          \n"
 108        "       .previous                               \n"
 109        : [r] "+r" (ret), [v] "=&r" (val), [u] "+m" (*uaddr),
 110          [t] "=&r" (tmp)
 111        : [ov] "Jr" (oldval), [nv] "Jr" (newval), [e] "Jr" (-EFAULT)
 112        : "memory");
 113
 114        __atomic_post_full_fence();
 115
 116        *uval = val;
 117        return ret;
 118}
 119
 120#endif /* CONFIG_SMP */
 121#endif /* __ASM_CSKY_FUTEX_H */
 122