xserver-multidpi/hw/xfree86/os-support/sco/sco_iop.c
Egbert Eich d23c46dd3e Modifying X.Org Xserver DDX to allow to run X with ordinary user
permissions when no access to HW registers is required. For API changes
    which mostly involve the modifications to make the RRFunc (introduced
    with 6.8) more flexible please check Bugzilla #2407. NOTE: This patch
    applies changes to OS specific files for other OSes which I cannot
    test.
2005-01-28 16:13:00 +00:00

129 lines
3.9 KiB
C

/* $XFree86$ */
/*
* Copyright 2001 by J. Kean Johnston <jkj@caldera.com>
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that
* copyright notice and this permission notice appear in supporting
* documentation, and that the name J. Kean Johnston not be used in
* advertising or publicity pertaining to distribution of the software without
* specific, written prior permission. J. Kean Johnston makes no
* representations about the suitability of this software for any purpose.
* It is provided "as is" without express or implied warranty.
*
* J. KEAN JOHNSTON DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
* EVENT SHALL J. KEAN JOHNSTON BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
* USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
* OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
/* $XConsortium$ */
#include "X.h"
#include "compiler.h"
#define _NEED_SYSI86
#include "xf86.h"
#include "xf86Priv.h"
#include "xf86OSpriv.h"
#include "xf86_OSlib.h"
/***************************************************************************/
/* I/O Permissions section */
/***************************************************************************/
/*
* There is a right way and a wrong way of doing this. Unfortunately, we
* are forced to do it the wrong way. The right way is to be told the range
* or ranges of I/O ports the driver(s) need access to, in order to use the
* CONS_IOPERM ioctl() to grant access only to those ports we care about.
* This way we can guarantee some small level of stability because a driver
* does not have access to all ports (which would mean it could play with
* the PIT and thus affect scheduling times, or a whole slew of other
* nasty things). However, because XFree86 currently only enables or disables
* ALL port access, we need to run at IOPL 3, which basically means the
* X Server runs at the same level as the kernel. You can image why this is
* unsafe. Oh, and this is not a problem unique to OSR5, other OSes are
* affected by this as well.
*
* So, for the time being, we change our IOPL until such time as the XFree86
* architecture is changed to allow for tighter control of I/O ports. If and
* when it is, then the CONS_ADDIOP/DELIOP ioctl() should be used to enable
* or disable access to the desired ports.
*/
extern long sysi86 (int cmd, ...);
static Bool IOEnabled = FALSE;
Bool xf86EnableIO(void)
{
if (IOEnabled)
return TRUE;
if (sysi86(SI86V86, V86SC_IOPL, PS_IOPL) < 0) {
xf86Msg(X_WARNING,"Failed to set IOPL for extended I/O\n");
return FALSE;
}
IOEnabled = TRUE;
return TRUE;
}
void xf86DisableIO(void)
{
if (!IOEnabled)
return;
sysi86(SI86V86, V86SC_IOPL, 0);
IOEnabled = FALSE;
}
/***************************************************************************/
/* Interrupt Handling section */
/***************************************************************************/
Bool xf86DisableInterrupts()
{
if (!IOEnabled) {
if (sysi86(SI86V86, V86SC_IOPL, PS_IOPL) < 0)
return FALSE;
}
#ifdef __GNUC__
__asm__ __volatile__("cli");
#else
asm("cli");
#endif /* __GNUC__ */
if (!IOEnabled) {
sysi86(SI86V86, V86SC_IOPL, PS_IOPL);
}
return(TRUE);
}
void xf86EnableInterrupts()
{
if (!IOEnabled) {
if (sysi86(SI86V86, V86SC_IOPL, PS_IOPL) < 0)
return;
}
#ifdef __GNUC__
__asm__ __volatile__("sti");
#else
asm("sti");
#endif /* __GNUC__ */
if (!IOEnabled) {
sysi86(SI86V86, V86SC_IOPL, PS_IOPL);
}
}