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futex.h

#ifndef _ASM_PARISC_FUTEX_H
#define _ASM_PARISC_FUTEX_H

#ifdef __KERNEL__

#include <linux/futex.h>
#include <linux/uaccess.h>
#include <asm/errno.h>

static inline int
futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
{
      int op = (encoded_op >> 28) & 7;
      int cmp = (encoded_op >> 24) & 15;
      int oparg = (encoded_op << 8) >> 20;
      int cmparg = (encoded_op << 20) >> 20;
      int oldval = 0, ret;
      if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
            oparg = 1 << oparg;

      if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
            return -EFAULT;

      pagefault_disable();

      switch (op) {
      case FUTEX_OP_SET:
      case FUTEX_OP_ADD:
      case FUTEX_OP_OR:
      case FUTEX_OP_ANDN:
      case FUTEX_OP_XOR:
      default:
            ret = -ENOSYS;
      }

      pagefault_enable();

      if (!ret) {
            switch (cmp) {
            case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
            case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
            case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
            case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
            case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
            case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
            default: ret = -ENOSYS;
            }
      }
      return ret;
}

/* Non-atomic version */
static inline int
futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
{
      int err = 0;
      int uval;

      /* futex.c wants to do a cmpxchg_inatomic on kernel NULL, which is
       * our gateway page, and causes no end of trouble...
       */
      if (segment_eq(KERNEL_DS, get_fs()) && !uaddr)
            return -EFAULT;

      if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
            return -EFAULT;

      err = get_user(uval, uaddr);
      if (err) return -EFAULT;
      if (uval == oldval)
            err = put_user(newval, uaddr);
      if (err) return -EFAULT;
      return uval;
}

#endif /*__KERNEL__*/
#endif /*_ASM_PARISC_FUTEX_H*/

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