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 for Mesa
  27  *
  28  *  Author: Daniel Borca
  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 #ifndef MAX
  40 #define MAX(x, y) (((x) < (y)) ? (y) : (x))
  41 #endif
  42
  43
  44 /* _create_linear_mapping:
  45  *  Maps a physical address range into linear memory.
  46  */
  47 int
  48 _create_linear_mapping (unsigned long *linear, unsigned long physaddr, int size)
  49 {
  50    __dpmi_meminfo meminfo;
  51
  52    if (physaddr >= 0x100000) {
  53       /* map into linear memory */
  54       meminfo.address = physaddr;
  55       meminfo.size = size;
  56       if (__dpmi_physical_address_mapping(&meminfo) != 0) {
  57          return -1;
  58       }
  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 /* _remove_linear_mapping:
  71  *  Frees the DPMI resources being used to map a linear address range.
  72  */
  73 void
  74 _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 /* _create_selector:
  90  *  Allocates a selector to access a region of linear memory.
  91  */
  92 int
  93 _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 /* _remove_selector:
 117  *  Frees a DPMI segment selector.
 118  */
 119 void
 120 _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 /* Desc: retrieve CPU MMX capability
 133  *
 134  * In  : -
 135  * Out : FALSE if CPU cannot do MMX
 136  *
 137  * Note: -
 138  */
 139 int
 140 _can_mmx (void)
 141 {
 142 #ifdef USE_MMX_ASM
 143    int x86_cpu_features = 0;
 144    __asm("\n\
 145                 pushfl                  \n\
 146                 popl    %%eax           \n\
 147                 movl    %%eax, %%ecx    \n\
 148                 xorl    $0x200000, %%eax\n\
 149                 pushl   %%eax           \n\
 150                 popfl                   \n\
 151                 pushfl                  \n\
 152                 popl    %%eax           \n\
 153                 pushl   %%ecx           \n\
 154                 popfl                   \n\
 155                 xorl    %%ecx, %%eax    \n\
 156                 jz 0f                   \n\
 157                 movl    $1, %%eax       \n\
 158                 cpuid                   \n\
 159                 movl    %%edx, %0       \n\
 160         0:                              \n\
 161    ":"=g"(x86_cpu_features)::"%eax", "%ebx", "%ecx", "%edx");
 162    return (x86_cpu_features & 0x00800000);
 163 #else
 164    return 0;
 165 #endif
 166 }