arch/ia64/include/asm/futex.h

   1 #ifndef _ASM_FUTEX_H
   2 #define _ASM_FUTEX_H
   3
   4 #include <linux/futex.h>
   5 #include <linux/uaccess.h>
   6 #include <asm/errno.h>
   7 #include <asm/system.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 futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
  50 {
  51         int op = (encoded_op >> 28) & 7;
  52         int cmp = (encoded_op >> 24) & 15;
  53         int oparg = (encoded_op << 8) >> 20;
  54         int cmparg = (encoded_op << 20) >> 20;
  55         int oldval = 0, ret;
  56         if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
  57                 oparg = 1 << oparg;
  58
  59         if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32)))
  60                 return -EFAULT;
  61
  62         pagefault_disable();
  63
  64         switch (op) {
  65         case FUTEX_OP_SET:
  66                 __futex_atomic_op1("xchg4 %1=[%2],%3", ret, oldval, uaddr,
  67                                    oparg);
  68                 break;
  69         case FUTEX_OP_ADD:
  70                 __futex_atomic_op2("add %3=%3,%5", ret, oldval, uaddr, oparg);
  71                 break;
  72         case FUTEX_OP_OR:
  73                 __futex_atomic_op2("or %3=%3,%5", ret, oldval, uaddr, oparg);
  74                 break;
  75         case FUTEX_OP_ANDN:
  76                 __futex_atomic_op2("and %3=%3,%5", ret, oldval, uaddr,
  77                                    ~oparg);
  78                 break;
  79         case FUTEX_OP_XOR:
  80                 __futex_atomic_op2("xor %3=%3,%5", ret, oldval, uaddr, oparg);
  81                 break;
  82         default:
  83                 ret = -ENOSYS;
  84         }
  85
  86         pagefault_enable();
  87
  88         if (!ret) {
  89                 switch (cmp) {
  90                 case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
  91                 case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
  92                 case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
  93                 case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
  94                 case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
  95                 case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
  96                 default: ret = -ENOSYS;
  97                 }
  98         }
  99         return ret;
 100 }
 101
 102 static inline int
 103 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
 104                               u32 oldval, u32 newval)
 105 {
 106         if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
 107                 return -EFAULT;
 108
 109         {
 110                 register unsigned long r8 __asm ("r8");
 111                 unsigned long prev;
 112                 __asm__ __volatile__(
 113                         "       mf;;                                    \n"
 114                         "       mov %0=r0                               \n"
 115                         "       mov ar.ccv=%4;;                         \n"
 116                         "[1:]   cmpxchg4.acq %1=[%2],%3,ar.ccv          \n"
 117                         "       .xdata4 \"__ex_table\", 1b-., 2f-.      \n"
 118                         "[2:]"
 119                         : "=r" (r8), "=r" (prev)
 120                         : "r" (uaddr), "r" (newval),
 121                           "rO" ((long) (unsigned) oldval)
 122                         : "memory");
 123                 *uval = prev;
 124                 return r8;
 125         }
 126 }
 127
 128 #endif /* _ASM_FUTEX_H */