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         "       .section __ex_table,\"a\"\n"                    \
  23         "       .long   1b-.\n"                                 \
  24         "       lda     $31,3b-1b(%1)\n"                        \
  25         "       .long   2b-.\n"                                 \
  26         "       lda     $31,3b-2b(%1)\n"                        \
  27         "       .previous\n"                                    \
  28         :       "=&r" (oldval), "=&r"(ret)                      \
  29         :       "r" (uaddr), "r"(oparg)                         \
  30         :       "memory")
  31
  32 static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
  33                 u32 __user *uaddr)
  34 {
  35         int oldval = 0, ret;
  36
  37         pagefault_disable();
  38
  39         switch (op) {
  40         case FUTEX_OP_SET:
  41                 __futex_atomic_op("mov %3,%1\n", ret, oldval, uaddr, oparg);
  42                 break;
  43         case FUTEX_OP_ADD:
  44                 __futex_atomic_op("addl %0,%3,%1\n", ret, oldval, uaddr, oparg);
  45                 break;
  46         case FUTEX_OP_OR:
  47                 __futex_atomic_op("or %0,%3,%1\n", ret, oldval, uaddr, oparg);
  48                 break;
  49         case FUTEX_OP_ANDN:
  50                 __futex_atomic_op("andnot %0,%3,%1\n", ret, oldval, uaddr, oparg);
  51                 break;
  52         case FUTEX_OP_XOR:
  53                 __futex_atomic_op("xor %0,%3,%1\n", ret, oldval, uaddr, oparg);
  54                 break;
  55         default:
  56                 ret = -ENOSYS;
  57         }
  58
  59         pagefault_enable();
  60
  61         if (!ret)
  62                 *oval = oldval;
  63
  64         return ret;
  65 }
  66
  67 static inline int
  68 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
  69                               u32 oldval, u32 newval)
  70 {
  71         int ret = 0, cmp;
  72         u32 prev;
  73
  74         if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
  75                 return -EFAULT;
  76
  77         __asm__ __volatile__ (
  78                 __ASM_SMP_MB
  79         "1:     ldl_l   %1,0(%3)\n"
  80         "       cmpeq   %1,%4,%2\n"
  81         "       beq     %2,3f\n"
  82         "       mov     %5,%2\n"
  83         "2:     stl_c   %2,0(%3)\n"
  84         "       beq     %2,4f\n"
  85         "3:     .subsection 2\n"
  86         "4:     br      1b\n"
  87         "       .previous\n"
  88         "       .section __ex_table,\"a\"\n"
  89         "       .long   1b-.\n"
  90         "       lda     $31,3b-1b(%0)\n"
  91         "       .long   2b-.\n"
  92         "       lda     $31,3b-2b(%0)\n"
  93         "       .previous\n"
  94         :       "+r"(ret), "=&r"(prev), "=&r"(cmp)
  95         :       "r"(uaddr), "r"((long)(int)oldval), "r"(newval)
  96         :       "memory");
  97
  98         *uval = prev;
  99         return ret;
 100 }
 101
 102 #endif /* __KERNEL__ */
 103 #endif /* _ASM_ALPHA_FUTEX_H */