arch/hexagon/include/asm/futex.h

   1 #ifndef _ASM_HEXAGON_FUTEX_H
   2 #define _ASM_HEXAGON_FUTEX_H
   3
   4 #ifdef __KERNEL__
   5
   6 #include <linux/futex.h>
   7 #include <linux/uaccess.h>
   8 #include <asm/errno.h>
   9
  10 /* XXX TODO-- need to add sync barriers! */
  11
  12 #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
  13         __asm__ __volatile( \
  14         "1: %0 = memw_locked(%3);\n" \
  15             /* For example: %1 = %4 */ \
  16             insn \
  17         "2: memw_locked(%3,p2) = %1;\n" \
  18         "   if !p2 jump 1b;\n" \
  19         "   %1 = #0;\n" \
  20         "3:\n" \
  21         ".section .fixup,\"ax\"\n" \
  22         "4: %1 = #%5;\n" \
  23         "   jump 3b\n" \
  24         ".previous\n" \
  25         ".section __ex_table,\"a\"\n" \
  26         ".long 1b,4b,2b,4b\n" \
  27         ".previous\n" \
  28         : "=&r" (oldval), "=&r" (ret), "+m" (*uaddr) \
  29         : "r" (uaddr), "r" (oparg), "i" (-EFAULT) \
  30         : "p2", "memory")
  31
  32
  33 static inline int
  34 arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
  35 {
  36         int oldval = 0, ret;
  37
  38         pagefault_disable();
  39
  40         switch (op) {
  41         case FUTEX_OP_SET:
  42                 __futex_atomic_op("%1 = %4\n", ret, oldval, uaddr, oparg);
  43                 break;
  44         case FUTEX_OP_ADD:
  45                 __futex_atomic_op("%1 = add(%0,%4)\n", ret, oldval, uaddr,
  46                                   oparg);
  47                 break;
  48         case FUTEX_OP_OR:
  49                 __futex_atomic_op("%1 = or(%0,%4)\n", ret, oldval, uaddr,
  50                                   oparg);
  51                 break;
  52         case FUTEX_OP_ANDN:
  53                 __futex_atomic_op("%1 = not(%4); %1 = and(%0,%1)\n", ret,
  54                                   oldval, uaddr, oparg);
  55                 break;
  56         case FUTEX_OP_XOR:
  57                 __futex_atomic_op("%1 = xor(%0,%4)\n", ret, oldval, uaddr,
  58                                   oparg);
  59                 break;
  60         default:
  61                 ret = -ENOSYS;
  62         }
  63
  64         pagefault_enable();
  65
  66         if (!ret)
  67                 *oval = oldval;
  68
  69         return ret;
  70 }
  71
  72 static inline int
  73 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 oldval,
  74                               u32 newval)
  75 {
  76         int prev;
  77         int ret;
  78
  79         if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
  80                 return -EFAULT;
  81
  82         __asm__ __volatile__ (
  83         "1: %1 = memw_locked(%3)\n"
  84         "   {\n"
  85         "      p2 = cmp.eq(%1,%4)\n"
  86         "      if !p2.new jump:NT 3f\n"
  87         "   }\n"
  88         "2: memw_locked(%3,p2) = %5\n"
  89         "   if !p2 jump 1b\n"
  90         "3:\n"
  91         ".section .fixup,\"ax\"\n"
  92         "4: %0 = #%6\n"
  93         "   jump 3b\n"
  94         ".previous\n"
  95         ".section __ex_table,\"a\"\n"
  96         ".long 1b,4b,2b,4b\n"
  97         ".previous\n"
  98         : "+r" (ret), "=&r" (prev), "+m" (*uaddr)
  99         : "r" (uaddr), "r" (oldval), "r" (newval), "i"(-EFAULT)
 100         : "p2", "memory");
 101
 102         *uval = prev;
 103         return ret;
 104 }
 105
 106 #endif /* __KERNEL__ */
 107 #endif /* _ASM_HEXAGON_FUTEX_H */