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/*
* Mesa 3-D graphics library
* Version: 4.0
*
* Copyright (C) 1999 Brian Paul All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
/*
* DOS/DJGPP device driver v1.3 for Mesa 5.0
*
* Copyright (C) 2002 - Borca Daniel
* Email : dborca@yahoo.com
* Web : http://www.geocities.com/dborca
*/
#include <dpmi.h>
#include "internal.h"
#ifndef MAX
#define MAX(x, y) (((x)<(y))?(y):(x))
#endif
/* _create_linear_mapping:
* Maps a physical address range into linear memory.
*/
static int _create_linear_mapping (unsigned long *linear, unsigned long physaddr, int size)
{
__dpmi_meminfo meminfo;
if (physaddr >= 0x100000) {
/* map into linear memory */
meminfo.address = physaddr;
meminfo.size = size;
if (__dpmi_physical_address_mapping(&meminfo) != 0)
return -1;
*linear = meminfo.address;
} else {
/* exploit 1 -> 1 physical to linear mapping in low megabyte */
*linear = physaddr;
}
return 0;
}
/* _remove_linear_mapping:
* Frees the DPMI resources being used to map a linear address range.
*/
static void _remove_linear_mapping (unsigned long *linear)
{
__dpmi_meminfo meminfo;
if (*linear) {
if (*linear >= 0x100000) {
meminfo.address = *linear;
__dpmi_free_physical_address_mapping(&meminfo);
}
*linear = 0;
}
}
/* _create_selector:
* Allocates a selector to access a region of linear memory.
*/
int _create_selector (int *segment, unsigned long base, int size)
{
/* allocate an ldt descriptor */
if ((*segment=__dpmi_allocate_ldt_descriptors(1)) < 0) {
*segment = 0;
return -1;
}
/* create the linear mapping */
if (_create_linear_mapping(&base, base, size)) {
__dpmi_free_ldt_descriptor(*segment);
*segment = 0;
return -1;
}
/* set the descriptor base and limit */
__dpmi_set_segment_base_address(*segment, base);
__dpmi_set_segment_limit(*segment, MAX(size-1, 0xFFFF));
return 0;
}
/* _remove_selector:
* Frees a DPMI segment selector.
*/
void _remove_selector (int *segment)
{
if (*segment) {
unsigned long base;
__dpmi_get_segment_base_address(*segment, &base);
_remove_linear_mapping(&base);
__dpmi_free_ldt_descriptor(*segment);
*segment = 0;
}
}
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