include/asm-mips/futex.h

   1 #ifndef _ASM_FUTEX_H
   2 #define _ASM_FUTEX_H
   3
   4 #ifdef __KERNEL__
   5
   6 #include <linux/config.h>
   7 #include <linux/futex.h>
   8 #include <asm/errno.h>
   9 #include <asm/uaccess.h>
  10
  11 #ifdef CONFIG_SMP
  12 #define __FUTEX_SMP_SYNC "      sync                                    \n"
  13 #else
  14 #define __FUTEX_SMP_SYNC
  15 #endif
  16
  17 #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg)              \
  18 {                                                                       \
  19         __asm__ __volatile__(                                           \
  20         "       .set    push                                    \n"     \
  21         "       .set    noat                                    \n"     \
  22         "       .set    mips3                                   \n"     \
  23         "1:     ll      %1, (%3)        # __futex_atomic_op1    \n"     \
  24         "       .set    mips0                                   \n"     \
  25         "       " insn  "                                       \n"     \
  26         "       .set    mips3                                   \n"     \
  27         "2:     sc      $1, (%3)                                \n"     \
  28         "       beqzl   $1, 1b                                  \n"     \
  29         __FUTEX_SMP_SYNC                                                \
  30         "3:                                                     \n"     \
  31         "       .set    pop                                     \n"     \
  32         "       .set    mips0                                   \n"     \
  33         "       .section .fixup,\"ax\"                          \n"     \
  34         "4:     li      %0, %5                                  \n"     \
  35         "       j       2b                                      \n"     \
  36         "       .previous                                       \n"     \
  37         "       .section __ex_table,\"a\"                       \n"     \
  38         "       "__UA_ADDR "\t1b, 4b                            \n"     \
  39         "       "__UA_ADDR "\t2b, 4b                            \n"     \
  40         "       .previous                                       \n"     \
  41         : "=r" (ret), "=r" (oldval)                                     \
  42         : "0" (0), "r" (uaddr), "Jr" (oparg), "i" (-EFAULT));           \
  43 }
  44
  45 static inline int
  46 futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
  47 {
  48         int op = (encoded_op >> 28) & 7;
  49         int cmp = (encoded_op >> 24) & 15;
  50         int oparg = (encoded_op << 8) >> 20;
  51         int cmparg = (encoded_op << 20) >> 20;
  52         int oldval = 0, ret;
  53         if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
  54                 oparg = 1 << oparg;
  55
  56         if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
  57                 return -EFAULT;
  58
  59         inc_preempt_count();
  60
  61         switch (op) {
  62         case FUTEX_OP_SET:
  63                 __futex_atomic_op("move $1, %z4", ret, oldval, uaddr, oparg);
  64                 break;
  65
  66         case FUTEX_OP_ADD:
  67                 __futex_atomic_op("addu $1, %1, %z4",
  68                                   ret, oldval, uaddr, oparg);
  69                 break;
  70         case FUTEX_OP_OR:
  71                 __futex_atomic_op("or   $1, %1, %z4",
  72                                   ret, oldval, uaddr, oparg);
  73                 break;
  74         case FUTEX_OP_ANDN:
  75                 __futex_atomic_op("and  $1, %1, %z4",
  76                                   ret, oldval, uaddr, ~oparg);
  77                 break;
  78         case FUTEX_OP_XOR:
  79                 __futex_atomic_op("xor  $1, %1, %z4",
  80                                   ret, oldval, uaddr, oparg);
  81                 break;
  82         default:
  83                 ret = -ENOSYS;
  84         }
  85
  86         dec_preempt_count();
  87
  88         if (!ret) {
  89                 switch (cmp) {
  90                 case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
  91                 case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
  92                 case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
  93                 case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
  94                 case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
  95                 case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
  96                 default: ret = -ENOSYS;
  97                 }
  98         }
  99         return ret;
 100 }
 101
 102 #endif
 103 #endif