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 futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
  35 {
  36         int op = (encoded_op >> 28) & 7;
  37         int cmp = (encoded_op >> 24) & 15;
  38         int oparg = (encoded_op << 8) >> 20;
  39         int cmparg = (encoded_op << 20) >> 20;
  40         int oldval = 0, ret;
  41         if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
  42                 oparg = 1 << oparg;
  43
  44         if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
  45                 return -EFAULT;
  46
  47         pagefault_disable();
  48
  49         switch (op) {
  50         case FUTEX_OP_SET:
  51                 __futex_atomic_op("%1 = %4\n", ret, oldval, uaddr, oparg);
  52                 break;
  53         case FUTEX_OP_ADD:
  54                 __futex_atomic_op("%1 = add(%0,%4)\n", ret, oldval, uaddr,
  55                                   oparg);
  56                 break;
  57         case FUTEX_OP_OR:
  58                 __futex_atomic_op("%1 = or(%0,%4)\n", ret, oldval, uaddr,
  59                                   oparg);
  60                 break;
  61         case FUTEX_OP_ANDN:
  62                 __futex_atomic_op("%1 = not(%4); %1 = and(%0,%1)\n", ret,
  63                                   oldval, uaddr, oparg);
  64                 break;
  65         case FUTEX_OP_XOR:
  66                 __futex_atomic_op("%1 = xor(%0,%4)\n", ret, oldval, uaddr,
  67                                   oparg);
  68                 break;
  69         default:
  70                 ret = -ENOSYS;
  71         }
  72
  73         pagefault_enable();
  74
  75         if (!ret) {
  76                 switch (cmp) {
  77                 case FUTEX_OP_CMP_EQ:
  78                         ret = (oldval == cmparg);
  79                         break;
  80                 case FUTEX_OP_CMP_NE:
  81                         ret = (oldval != cmparg);
  82                         break;
  83                 case FUTEX_OP_CMP_LT:
  84                         ret = (oldval < cmparg);
  85                         break;
  86                 case FUTEX_OP_CMP_GE:
  87                         ret = (oldval >= cmparg);
  88                         break;
  89                 case FUTEX_OP_CMP_LE:
  90                         ret = (oldval <= cmparg);
  91                         break;
  92                 case FUTEX_OP_CMP_GT:
  93                         ret = (oldval > cmparg);
  94                         break;
  95                 default:
  96                         ret = -ENOSYS;
  97                 }
  98         }
  99         return ret;
 100 }
 101
 102 static inline int
 103 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 oldval,
 104                               u32 newval)
 105 {
 106         int prev;
 107         int ret;
 108
 109         if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
 110                 return -EFAULT;
 111
 112         __asm__ __volatile__ (
 113         "1: %1 = memw_locked(%3)\n"
 114         "   {\n"
 115         "      p2 = cmp.eq(%1,%4)\n"
 116         "      if !p2.new jump:NT 3f\n"
 117         "   }\n"
 118         "2: memw_locked(%3,p2) = %5\n"
 119         "   if !p2 jump 1b\n"
 120         "3:\n"
 121         ".section .fixup,\"ax\"\n"
 122         "4: %0 = #%6\n"
 123         "   jump 3b\n"
 124         ".previous\n"
 125         ".section __ex_table,\"a\"\n"
 126         ".long 1b,4b,2b,4b\n"
 127         ".previous\n"
 128         : "+r" (ret), "=&r" (prev), "+m" (*uaddr)
 129         : "r" (uaddr), "r" (oldval), "r" (newval), "i"(-EFAULT)
 130         : "p2", "memory");
 131
 132         *uval = prev;
 133         return ret;
 134 }
 135
 136 #endif /* __KERNEL__ */
 137 #endif /* _ASM_HEXAGON_FUTEX_H */