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/* Copyright (C) 2004 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Robert Millan <robertmh@gnu.org>
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <errno.h>
#include <fcntl.h> /* open */
#include <unistd.h> /* close */
static int __iopl_fd = -1;
int
iopl (int level)
{
switch (level)
{
case 3:
if (__iopl_fd != -1)
return 0;
__iopl_fd = __open ("/dev/io", O_RDWR);
if (__iopl_fd == -1)
{
if (errno == EACCES)
__set_errno (EPERM);
return -1;
}
return 0;
case 0:
if (__iopl_fd != -1)
if (__close (__iopl_fd) == -1)
return 1;
return 0;
default:
__set_errno (EINVAL);
return -1;
}
}
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