arch/s390/include/asm/futex.h

   1 #ifndef _ASM_S390_FUTEX_H
   2 #define _ASM_S390_FUTEX_H
   3
   4 #ifdef __KERNEL__
   5
   6 #include <linux/futex.h>
   7 #include <linux/uaccess.h>
   8 #include <asm/errno.h>
   9
  10 static inline int futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
  11 {
  12         int op = (encoded_op >> 28) & 7;
  13         int cmp = (encoded_op >> 24) & 15;
  14         int oparg = (encoded_op << 8) >> 20;
  15         int cmparg = (encoded_op << 20) >> 20;
  16         int oldval, ret;
  17
  18         if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
  19                 oparg = 1 << oparg;
  20
  21         if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32)))
  22                 return -EFAULT;
  23
  24         pagefault_disable();
  25         ret = uaccess.futex_atomic_op(op, uaddr, oparg, &oldval);
  26         pagefault_enable();
  27
  28         if (!ret) {
  29                 switch (cmp) {
  30                 case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
  31                 case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
  32                 case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
  33                 case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
  34                 case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
  35                 case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
  36                 default: ret = -ENOSYS;
  37                 }
  38         }
  39         return ret;
  40 }
  41
  42 static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
  43                                                 u32 oldval, u32 newval)
  44 {
  45         if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32)))
  46                 return -EFAULT;
  47
  48         return uaccess.futex_atomic_cmpxchg(uval, uaddr, oldval, newval);
  49 }
  50
  51 #endif /* __KERNEL__ */
  52 #endif /* _ASM_S390_FUTEX_H */