src/mesa/drivers/dos/dpmi.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  4.0
   4  *
   5  * Copyright (C) 1999  Brian Paul   All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 /*
  26  * DOS/DJGPP device driver v1.4 for Mesa
  27  *
  28  *  Copyright (C) 2002 - Borca Daniel
  29  *  Email : dborca@yahoo.com
  30  *  Web   : http://www.geocities.com/dborca
  31  */
  32
  33
  34 #include <dpmi.h>
  35
  36 #include "internal.h"
  37
  38
  39
  40 #ifndef MAX
  41 #define MAX(x, y) (((x)<(y))?(y):(x))
  42 #endif
  43
  44
  45
  46 /* _create_linear_mapping:
  47  *  Maps a physical address range into linear memory.
  48  */
  49 int _create_linear_mapping (unsigned long *linear, unsigned long physaddr, int size)
  50 {
  51  __dpmi_meminfo meminfo;
  52
  53  if (physaddr >= 0x100000) {
  54     /* map into linear memory */
  55     meminfo.address = physaddr;
  56     meminfo.size = size;
  57     if (__dpmi_physical_address_mapping(&meminfo) != 0)
  58        return -1;
  59
  60     *linear = meminfo.address;
  61  } else {
  62     /* exploit 1 -> 1 physical to linear mapping in low megabyte */
  63     *linear = physaddr;
  64  }
  65
  66  return 0;
  67 }
  68
  69
  70
  71 /* _remove_linear_mapping:
  72  *  Frees the DPMI resources being used to map a linear address range.
  73  */
  74 void _remove_linear_mapping (unsigned long *linear)
  75 {
  76  __dpmi_meminfo meminfo;
  77
  78  if (*linear) {
  79     if (*linear >= 0x100000) {
  80        meminfo.address = *linear;
  81        __dpmi_free_physical_address_mapping(&meminfo);
  82     }
  83
  84     *linear = 0;
  85  }
  86 }
  87
  88
  89
  90 /* _create_selector:
  91  *  Allocates a selector to access a region of linear memory.
  92  */
  93 int _create_selector (int *segment, unsigned long base, int size)
  94 {
  95  /* allocate an ldt descriptor */
  96  if ((*segment=__dpmi_allocate_ldt_descriptors(1)) < 0) {
  97     *segment = 0;
  98     return -1;
  99  }
 100
 101  /* create the linear mapping */
 102  if (_create_linear_mapping(&base, base, size)) {
 103     __dpmi_free_ldt_descriptor(*segment);
 104     *segment = 0;
 105     return -1;
 106  }
 107
 108  /* set the descriptor base and limit */
 109  __dpmi_set_segment_base_address(*segment, base);
 110  __dpmi_set_segment_limit(*segment, MAX(size-1, 0xFFFF));
 111
 112  return 0;
 113 }
 114
 115
 116
 117 /* _remove_selector:
 118  *  Frees a DPMI segment selector.
 119  */
 120 void _remove_selector (int *segment)
 121 {
 122  if (*segment) {
 123     unsigned long base;
 124     __dpmi_get_segment_base_address(*segment, &base);
 125     _remove_linear_mapping(&base);
 126     __dpmi_free_ldt_descriptor(*segment);
 127     *segment = 0;
 128  }
 129 }
 130
 131
 132
 133 /* Desc: retrieve CPU MMX capability
 134  *
 135  * In  : -
 136  * Out : FALSE if CPU cannot do MMX
 137  *
 138  * Note: -
 139  */
 140 int _can_mmx (void)
 141 {
 142 #ifdef USE_MMX_ASM
 143  extern int _mesa_x86_cpu_features;
 144  return (_mesa_x86_cpu_features & 0x00800000);
 145 #else
 146  return 0;
 147 #endif
 148 }