libdha/sysdep/pci_os2.c

   1 /*
   2    This file is based on:
   3    $XFree86: xc/programs/Xserver/hw/xfree86/etc/scanpci.c,v 3.34.2.17 1998/11/10 11:55:40 dawes Exp $
   4    Modified for readability by Nick Kurshev
   5 */
   6 #define INCL_DOSFILEMGR
   7 #include <os2.h>
   8
   9 static USHORT callgate[3] = {0,0,0};
  10
  11 static __inline__ int enable_os_io(void)
  12 {
  13         HFILE hfd;
  14         ULONG dlen,action;
  15         APIRET rc;
  16         static char *ioDrvPath = "/dev/fastio$";
  17
  18         if (DosOpen((PSZ)ioDrvPath, (PHFILE)&hfd, (PULONG)&action,
  19            (ULONG)0, FILE_SYSTEM, FILE_OPEN,
  20            OPEN_SHARE_DENYNONE|OPEN_FLAGS_NOINHERIT|OPEN_ACCESS_READONLY,
  21            (ULONG)0) != 0) {
  22                 fprintf(stderr,"Error opening fastio$ driver...\n");
  23                 fprintf(stderr,"Please install xf86sup.sys in config.sys!\n");
  24                 return(42);
  25         }
  26         callgate[0] = callgate[1] = 0;
  27
  28 /* Get callgate from driver for fast io to ports and other stuff */
  29
  30         rc = DosDevIOCtl(hfd, (ULONG)0x76, (ULONG)0x64,
  31                 NULL, 0, NULL,
  32                 (ULONG*)&callgate[2], sizeof(USHORT), &dlen);
  33         if (rc) {
  34                 fprintf(stderr,"xf86-OS/2: EnableIOPorts failed, rc=%d, dlen=%d; emergency exit\n",
  35                         rc,dlen);
  36                 DosClose(hfd);
  37                 return(42);
  38         }
  39
  40 /* Calling callgate with function 13 sets IOPL for the program */
  41
  42         asm volatile ("movl $13,%%ebx;.byte 0xff,0x1d;.long _callgate"
  43                         : /*no outputs */
  44                         : /*no inputs */
  45                         : "eax","ebx","ecx","edx","cc");
  46
  47         DosClose(hfd);
  48         return(0);
  49 }
  50
  51 static __inline__ int disable_os_io(void)
  52 {
  53 /* Nothing to do */
  54         return(0);
  55 }