xorg-server-1.4/hw/xfree86/os-support/usl/usl_iop.c

   1 /*
   2  * Copyright 2001,2005 by Kean Johnston <jkj@sco.com>
   3  *
   4  * Permission to use, copy, modify, distribute, and sell this software and its
   5  * documentation for any purpose is hereby granted without fee, provided that
   6  * the above copyright notice appear in all copies and that both that
   7  * copyright notice and this permission notice appear in supporting
   8  * documentation, and that the name Kean Johnston not be used in
   9  * advertising or publicity pertaining to distribution of the software without
  10  * specific, written prior permission.  Kean Johnston makes no
  11  * representations about the suitability of this software for any purpose.
  12  * It is provided "as is" without express or implied warranty.
  13  *
  14  * KEAN JOHNSTON DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  15  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  16  * EVENT SHALL KEAN JOHNSTON BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  17  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
  18  * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
  19  * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  20  * PERFORMANCE OF THIS SOFTWARE.
  21  */
  22
  23
  24 #include "X.h"
  25
  26 #include "compiler.h"
  27
  28 #define _NEED_SYSI86
  29 #include "xf86.h"
  30 #include "xf86Priv.h"
  31 #include "xf86OSpriv.h"
  32 #include "xf86_OSlib.h"
  33
  34
  35 /***************************************************************************/
  36 /* I/O Permissions section                                                 */
  37 /***************************************************************************/
  38
  39 static Bool IOEnabled = FALSE;
  40
  41 _X_EXPORT Bool
  42 xf86EnableIO(void)
  43 {
  44   if (IOEnabled)
  45     return TRUE;
  46
  47   if (sysi86(SI86IOPL, 3) < 0)
  48     FatalError("Failed to set IOPL for extended I/O\n");
  49   IOEnabled = TRUE;
  50   return TRUE;
  51 }
  52
  53 _X_EXPORT void
  54 xf86DisableIO(void)
  55 {
  56   if (!IOEnabled)
  57     return;
  58
  59   sysi86(SI86IOPL, 0);
  60   IOEnabled = FALSE;
  61 }
  62
  63 /***************************************************************************/
  64 /* Interrupt Handling section                                              */
  65 /***************************************************************************/
  66
  67 _X_EXPORT Bool
  68 xf86DisableInterrupts(void)
  69 {
  70   if (!IOEnabled) {
  71     if (sysi86(SI86IOPL, 3) < 0)
  72       return FALSE;
  73   }
  74
  75 #ifdef __GNUC__
  76   __asm__ __volatile__("cli");
  77 #else
  78   asm("cli");
  79 #endif /* __GNUC__ */
  80
  81   if (!IOEnabled) {
  82     sysi86(SI86IOPL, 0);
  83   }
  84
  85   return(TRUE);
  86 }
  87
  88 _X_EXPORT void
  89 xf86EnableInterrupts(void)
  90 {
  91   if (!IOEnabled) {
  92     if (sysi86(SI86IOPL, 3) < 0)
  93       return;
  94   }
  95
  96 #ifdef __GNUC__
  97   __asm__ __volatile__("sti");
  98 #else
  99   asm("sti");
 100 #endif /* __GNUC__ */
 101
 102   if (!IOEnabled) {
 103     sysi86(SI86IOPL, 0);
 104   }
 105 }
 106