freebsd-skq/sys/dev/io/iodev.c
marcel ef030a7c4e Use io(4) for I/O port access on ia64, rather than through sysarch(2).
I/O port access is implemented on Itanium by reading and writing to a
special region in memory. To hide details and avoid misaligned memory
accesses, a process did I/O port reads and writes by making a MD system
call. There's one fatal problem with this approach: unprivileged access
was not being prevented. /dev/io serves that purpose on amd64/i386, so
employ it on ia64 as well. Use an ioctl for doing the actual I/O and
remove the sysarch(2) interface.

Backward compatibility is not being considered. The sysarch(2) approach
was added to support X11, but support for FreeBSD/ia64 was never fully
implemented in X11. Thus, nothing gets broken that didn't need more work
to begin with.

MFC after:	1 week
2010-01-11 18:10:13 +00:00

89 lines
2.3 KiB
C

/*-
* Copyright (c) 2004 Mark R V Murray
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer
* in this position and unchanged.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/signalvar.h>
#include <sys/systm.h>
#include <sys/uio.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <machine/iodev.h>
static struct cdev *iodev;
static struct cdevsw io_cdevsw = {
.d_version = D_VERSION,
.d_open = ioopen,
.d_close = ioclose,
.d_ioctl = ioioctl,
.d_name = "io",
};
/* ARGSUSED */
static int
io_modevent(module_t mod __unused, int type, void *data __unused)
{
switch(type) {
case MOD_LOAD:
if (bootverbose)
printf("io: <I/O>\n");
iodev = make_dev(&io_cdevsw, 0,
UID_ROOT, GID_WHEEL, 0600, "io");
break;
case MOD_UNLOAD:
destroy_dev(iodev);
break;
case MOD_SHUTDOWN:
break;
default:
return(EOPNOTSUPP);
break;
}
return (0);
}
DEV_MODULE(io, io_modevent, NULL);
MODULE_VERSION(io, 1);