arch/ia64/include/asm/futex.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_FUTEX_H
   3 #define _ASM_FUTEX_H
   4
   5 #include <linux/futex.h>
   6 #include <linux/uaccess.h>
   7 #include <asm/errno.h>
   8
   9 #define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg) \
  10 do {                                                                    \
  11         register unsigned long r8 __asm ("r8") = 0;                     \
  12         __asm__ __volatile__(                                           \
  13                 "       mf;;                                    \n"     \
  14                 "[1:] " insn ";;                                \n"     \
  15                 "       .xdata4 \"__ex_table\", 1b-., 2f-.      \n"     \
  16                 "[2:]"                                                  \
  17                 : "+r" (r8), "=r" (oldval)                              \
  18                 : "r" (uaddr), "r" (oparg)                              \
  19                 : "memory");                                            \
  20         ret = r8;                                                       \
  21 } while (0)
  22
  23 #define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg) \
  24 do {                                                                    \
  25         register unsigned long r8 __asm ("r8") = 0;                     \
  26         int val, newval;                                                \
  27         do {                                                            \
  28                 __asm__ __volatile__(                                   \
  29                         "       mf;;                              \n"   \
  30                         "[1:]   ld4 %3=[%4];;                     \n"   \
  31                         "       mov %2=%3                         \n"   \
  32                                 insn    ";;                       \n"   \
  33                         "       mov ar.ccv=%2;;                   \n"   \
  34                         "[2:]   cmpxchg4.acq %1=[%4],%3,ar.ccv;;  \n"   \
  35                         "       .xdata4 \"__ex_table\", 1b-., 3f-.\n"   \
  36                         "       .xdata4 \"__ex_table\", 2b-., 3f-.\n"   \
  37                         "[3:]"                                          \
  38                         : "+r" (r8), "=r" (val), "=&r" (oldval),        \
  39                            "=&r" (newval)                               \
  40                         : "r" (uaddr), "r" (oparg)                      \
  41                         : "memory");                                    \
  42                 if (unlikely (r8))                                      \
  43                         break;                                          \
  44         } while (unlikely (val != oldval));                             \
  45         ret = r8;                                                       \
  46 } while (0)
  47
  48 static inline int
  49 arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
  50 {
  51         int oldval = 0, ret;
  52
  53         pagefault_disable();
  54
  55         switch (op) {
  56         case FUTEX_OP_SET:
  57                 __futex_atomic_op1("xchg4 %1=[%2],%3", ret, oldval, uaddr,
  58                                    oparg);
  59                 break;
  60         case FUTEX_OP_ADD:
  61                 __futex_atomic_op2("add %3=%3,%5", ret, oldval, uaddr, oparg);
  62                 break;
  63         case FUTEX_OP_OR:
  64                 __futex_atomic_op2("or %3=%3,%5", ret, oldval, uaddr, oparg);
  65                 break;
  66         case FUTEX_OP_ANDN:
  67                 __futex_atomic_op2("and %3=%3,%5", ret, oldval, uaddr,
  68                                    ~oparg);
  69                 break;
  70         case FUTEX_OP_XOR:
  71                 __futex_atomic_op2("xor %3=%3,%5", ret, oldval, uaddr, oparg);
  72                 break;
  73         default:
  74                 ret = -ENOSYS;
  75         }
  76
  77         pagefault_enable();
  78
  79         if (!ret)
  80                 *oval = oldval;
  81
  82         return ret;
  83 }
  84
  85 static inline int
  86 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
  87                               u32 oldval, u32 newval)
  88 {
  89         if (!access_ok(uaddr, sizeof(u32)))
  90                 return -EFAULT;
  91
  92         {
  93                 register unsigned long r8 __asm ("r8") = 0;
  94                 unsigned long prev;
  95                 __asm__ __volatile__(
  96                         "       mf;;                                    \n"
  97                         "       mov ar.ccv=%4;;                         \n"
  98                         "[1:]   cmpxchg4.acq %1=[%2],%3,ar.ccv          \n"
  99                         "       .xdata4 \"__ex_table\", 1b-., 2f-.      \n"
 100                         "[2:]"
 101                         : "+r" (r8), "=&r" (prev)
 102                         : "r" (uaddr), "r" (newval),
 103                           "rO" ((long) (unsigned) oldval)
 104                         : "memory");
 105                 *uval = prev;
 106                 return r8;
 107         }
 108 }
 109
 110 #endif /* _ASM_FUTEX_H */