arch/alpha/include/asm/futex.h

   1 #ifndef _ASM_ALPHA_FUTEX_H
   2 #define _ASM_ALPHA_FUTEX_H
   3
   4 #ifdef __KERNEL__
   5
   6 #include <linux/futex.h>
   7 #include <linux/uaccess.h>
   8 #include <asm/errno.h>
   9 #include <asm/barrier.h>
  10
  11 #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg)      \
  12         __asm__ __volatile__(                                   \
  13                 __ASM_SMP_MB                                    \
  14         "1:     ldl_l   %0,0(%2)\n"                             \
  15                 insn                                            \
  16         "2:     stl_c   %1,0(%2)\n"                             \
  17         "       beq     %1,4f\n"                                \
  18         "       mov     $31,%1\n"                               \
  19         "3:     .subsection 2\n"                                \
  20         "4:     br      1b\n"                                   \
  21         "       .previous\n"                                    \
  22         EXC(1b,3b,%1,$31)                                       \
  23         EXC(2b,3b,%1,$31)                                       \
  24         :       "=&r" (oldval), "=&r"(ret)                      \
  25         :       "r" (uaddr), "r"(oparg)                         \
  26         :       "memory")
  27
  28 static inline int futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
  29 {
  30         int op = (encoded_op >> 28) & 7;
  31         int cmp = (encoded_op >> 24) & 15;
  32         int oparg = (encoded_op << 8) >> 20;
  33         int cmparg = (encoded_op << 20) >> 20;
  34         int oldval = 0, ret;
  35         if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
  36                 oparg = 1 << oparg;
  37
  38         if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
  39                 return -EFAULT;
  40
  41         pagefault_disable();
  42
  43         switch (op) {
  44         case FUTEX_OP_SET:
  45                 __futex_atomic_op("mov %3,%1\n", ret, oldval, uaddr, oparg);
  46                 break;
  47         case FUTEX_OP_ADD:
  48                 __futex_atomic_op("addl %0,%3,%1\n", ret, oldval, uaddr, oparg);
  49                 break;
  50         case FUTEX_OP_OR:
  51                 __futex_atomic_op("or %0,%3,%1\n", ret, oldval, uaddr, oparg);
  52                 break;
  53         case FUTEX_OP_ANDN:
  54                 __futex_atomic_op("andnot %0,%3,%1\n", ret, oldval, uaddr, oparg);
  55                 break;
  56         case FUTEX_OP_XOR:
  57                 __futex_atomic_op("xor %0,%3,%1\n", ret, oldval, uaddr, oparg);
  58                 break;
  59         default:
  60                 ret = -ENOSYS;
  61         }
  62
  63         pagefault_enable();
  64
  65         if (!ret) {
  66                 switch (cmp) {
  67                 case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
  68                 case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
  69                 case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
  70                 case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
  71                 case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
  72                 case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
  73                 default: ret = -ENOSYS;
  74                 }
  75         }
  76         return ret;
  77 }
  78
  79 static inline int
  80 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
  81                               u32 oldval, u32 newval)
  82 {
  83         int ret = 0, cmp;
  84         u32 prev;
  85
  86         if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
  87                 return -EFAULT;
  88
  89         __asm__ __volatile__ (
  90                 __ASM_SMP_MB
  91         "1:     ldl_l   %1,0(%3)\n"
  92         "       cmpeq   %1,%4,%2\n"
  93         "       beq     %2,3f\n"
  94         "       mov     %5,%2\n"
  95         "2:     stl_c   %2,0(%3)\n"
  96         "       beq     %2,4f\n"
  97         "3:     .subsection 2\n"
  98         "4:     br      1b\n"
  99         "       .previous\n"
 100         EXC(1b,3b,%0,$31)
 101         EXC(2b,3b,%0,$31)
 102         :       "+r"(ret), "=&r"(prev), "=&r"(cmp)
 103         :       "r"(uaddr), "r"((long)(int)oldval), "r"(newval)
 104         :       "memory");
 105
 106         *uval = prev;
 107         return ret;
 108 }
 109
 110 #endif /* __KERNEL__ */
 111 #endif /* _ASM_ALPHA_FUTEX_H */