arch/csky/include/asm/futex.h

   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
  41 static inline int
  42 arch_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
  82 static inline int
  83 futex_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 */