include/asm-mips/futex.h

   1 #ifndef _ASM_FUTEX_H
   2 #define _ASM_FUTEX_H
   3
   4 #ifdef __KERNEL__
   5
   6 #include <linux/futex.h>
   7 #include <asm/errno.h>
   8 #include <asm/uaccess.h>
   9
  10 #ifdef CONFIG_SMP
  11 #define __FUTEX_SMP_SYNC "      sync                                    \n"
  12 #else
  13 #define __FUTEX_SMP_SYNC
  14 #endif
  15
  16 #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg)              \
  17 {                                                                       \
  18         __asm__ __volatile__(                                           \
  19         "       .set    push                                    \n"     \
  20         "       .set    noat                                    \n"     \
  21         "       .set    mips3                                   \n"     \
  22         "1:     ll      %1, (%3)        # __futex_atomic_op1    \n"     \
  23         "       .set    mips0                                   \n"     \
  24         "       " insn  "                                       \n"     \
  25         "       .set    mips3                                   \n"     \
  26         "2:     sc      $1, (%3)                                \n"     \
  27         "       beqzl   $1, 1b                                  \n"     \
  28         __FUTEX_SMP_SYNC                                                \
  29         "3:                                                     \n"     \
  30         "       .set    pop                                     \n"     \
  31         "       .set    mips0                                   \n"     \
  32         "       .section .fixup,\"ax\"                          \n"     \
  33         "4:     li      %0, %5                                  \n"     \
  34         "       j       2b                                      \n"     \
  35         "       .previous                                       \n"     \
  36         "       .section __ex_table,\"a\"                       \n"     \
  37         "       "__UA_ADDR "\t1b, 4b                            \n"     \
  38         "       "__UA_ADDR "\t2b, 4b                            \n"     \
  39         "       .previous                                       \n"     \
  40         : "=r" (ret), "=r" (oldval)                                     \
  41         : "0" (0), "r" (uaddr), "Jr" (oparg), "i" (-EFAULT));           \
  42 }
  43
  44 static inline int
  45 futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
  46 {
  47         int op = (encoded_op >> 28) & 7;
  48         int cmp = (encoded_op >> 24) & 15;
  49         int oparg = (encoded_op << 8) >> 20;
  50         int cmparg = (encoded_op << 20) >> 20;
  51         int oldval = 0, ret;
  52         if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
  53                 oparg = 1 << oparg;
  54
  55         if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
  56                 return -EFAULT;
  57
  58         inc_preempt_count();
  59
  60         switch (op) {
  61         case FUTEX_OP_SET:
  62                 __futex_atomic_op("move $1, %z4", ret, oldval, uaddr, oparg);
  63                 break;
  64
  65         case FUTEX_OP_ADD:
  66                 __futex_atomic_op("addu $1, %1, %z4",
  67                                   ret, oldval, uaddr, oparg);
  68                 break;
  69         case FUTEX_OP_OR:
  70                 __futex_atomic_op("or   $1, %1, %z4",
  71                                   ret, oldval, uaddr, oparg);
  72                 break;
  73         case FUTEX_OP_ANDN:
  74                 __futex_atomic_op("and  $1, %1, %z4",
  75                                   ret, oldval, uaddr, ~oparg);
  76                 break;
  77         case FUTEX_OP_XOR:
  78                 __futex_atomic_op("xor  $1, %1, %z4",
  79                                   ret, oldval, uaddr, oparg);
  80                 break;
  81         default:
  82                 ret = -ENOSYS;
  83         }
  84
  85         dec_preempt_count();
  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(int __user *uaddr, int oldval, int newval)
 103 {
 104         return -ENOSYS;
 105 }
 106
 107 #endif
 108 #endif