kernel/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
   8 #define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg) \
   9 do {                                                                    \
  10         register unsigned long r8 __asm ("r8") = 0;                     \
  11         __asm__ __volatile__(                                           \
  12                 "       mf;;                                    \n"     \
  13                 "[1:] " insn ";;                                \n"     \
  14                 "       .xdata4 \"__ex_table\", 1b-., 2f-.      \n"     \
  15                 "[2:]"                                                  \
  16                 : "+r" (r8), "=r" (oldval)                              \
  17                 : "r" (uaddr), "r" (oparg)                              \
  18                 : "memory");                                            \
  19         ret = r8;                                                       \
  20 } while (0)
  21
  22 #define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg) \
  23 do {                                                                    \
  24         register unsigned long r8 __asm ("r8") = 0;                     \
  25         int val, newval;                                                \
  26         do {                                                            \
  27                 __asm__ __volatile__(                                   \
  28                         "       mf;;                              \n"   \
  29                         "[1:]   ld4 %3=[%4];;                     \n"   \
  30                         "       mov %2=%3                         \n"   \
  31                                 insn    ";;                       \n"   \
  32                         "       mov ar.ccv=%2;;                   \n"   \
  33                         "[2:]   cmpxchg4.acq %1=[%4],%3,ar.ccv;;  \n"   \
  34                         "       .xdata4 \"__ex_table\", 1b-., 3f-.\n"   \
  35                         "       .xdata4 \"__ex_table\", 2b-., 3f-.\n"   \
  36                         "[3:]"                                          \
  37                         : "+r" (r8), "=r" (val), "=&r" (oldval),        \
  38                            "=&r" (newval)                               \
  39                         : "r" (uaddr), "r" (oparg)                      \
  40                         : "memory");                                    \
  41                 if (unlikely (r8))                                      \
  42                         break;                                          \
  43         } while (unlikely (val != oldval));                             \
  44         ret = r8;                                                       \
  45 } while (0)
  46
  47 static inline int
  48 futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
  49 {
  50         int op = (encoded_op >> 28) & 7;
  51         int cmp = (encoded_op >> 24) & 15;
  52         int oparg = (encoded_op << 8) >> 20;
  53         int cmparg = (encoded_op << 20) >> 20;
  54         int oldval = 0, ret;
  55         if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
  56                 oparg = 1 << oparg;
  57
  58         if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32)))
  59                 return -EFAULT;
  60
  61         pagefault_disable();
  62
  63         switch (op) {
  64         case FUTEX_OP_SET:
  65                 __futex_atomic_op1("xchg4 %1=[%2],%3", ret, oldval, uaddr,
  66                                    oparg);
  67                 break;
  68         case FUTEX_OP_ADD:
  69                 __futex_atomic_op2("add %3=%3,%5", ret, oldval, uaddr, oparg);
  70                 break;
  71         case FUTEX_OP_OR:
  72                 __futex_atomic_op2("or %3=%3,%5", ret, oldval, uaddr, oparg);
  73                 break;
  74         case FUTEX_OP_ANDN:
  75                 __futex_atomic_op2("and %3=%3,%5", ret, oldval, uaddr,
  76                                    ~oparg);
  77                 break;
  78         case FUTEX_OP_XOR:
  79                 __futex_atomic_op2("xor %3=%3,%5", ret, oldval, uaddr, oparg);
  80                 break;
  81         default:
  82                 ret = -ENOSYS;
  83         }
  84
  85         pagefault_enable();
  86
  87         if (!ret) {
  88                 switch (cmp) {
  89                 case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
  90                 case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
  91                 case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
  92                 case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
  93                 case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
  94                 case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
  95                 default: ret = -ENOSYS;
  96                 }
  97         }
  98         return ret;
  99 }
 100
 101 static inline int
 102 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
 103                               u32 oldval, u32 newval)
 104 {
 105         if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
 106                 return -EFAULT;
 107
 108         {
 109                 register unsigned long r8 __asm ("r8") = 0;
 110                 unsigned long prev;
 111                 __asm__ __volatile__(
 112                         "       mf;;                                    \n"
 113                         "       mov ar.ccv=%4;;                         \n"
 114                         "[1:]   cmpxchg4.acq %1=[%2],%3,ar.ccv          \n"
 115                         "       .xdata4 \"__ex_table\", 1b-., 2f-.      \n"
 116                         "[2:]"
 117                         : "+r" (r8), "=&r" (prev)
 118                         : "r" (uaddr), "r" (newval),
 119                           "rO" ((long) (unsigned) oldval)
 120                         : "memory");
 121                 *uval = prev;
 122                 return r8;
 123         }
 124 }
 125
 126 #endif /* _ASM_FUTEX_H */