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/*
* Mesa 3-D graphics library
*
* Copyright (C) 1999-2008 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
* THE AUTHORS OR COPYRIGHT HOLDERS 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.
*/
/**
* \file glapi_entrypoint.c
*
* Arch-specific code for manipulating GL API entrypoints (dispatch stubs).
*/
#include <string.h>
#include "c11/threads.h"
#include "glapi/glapi_priv.h"
#include "u_execmem.h"
#ifdef USE_X86_ASM
extern GLubyte gl_dispatch_functions_start[];
extern GLubyte gl_dispatch_functions_end[];
#endif /* USE_X86_ASM */
#if defined(DISPATCH_FUNCTION_SIZE)
_glapi_proc
get_entrypoint_address(unsigned int functionOffset)
{
return (_glapi_proc) (gl_dispatch_functions_start
+ (DISPATCH_FUNCTION_SIZE * functionOffset));
}
#endif
#if defined(USE_X86_ASM)
/**
* Perform platform-specific GL API entry-point fixups.
*/
static void
init_glapi_relocs( void )
{
#if !defined(GLX_X86_READONLY_TEXT)
extern unsigned long _x86_get_dispatch(void);
char run_time_patch[] = {
0x65, 0xa1, 0, 0, 0, 0 /* movl %gs:0,%eax */
};
GLuint *offset = (GLuint *) &run_time_patch[2]; /* 32-bits for x86/32 */
const GLubyte * const get_disp = (const GLubyte *) run_time_patch;
GLubyte * curr_func = (GLubyte *) gl_dispatch_functions_start;
*offset = _x86_get_dispatch();
while ( curr_func != (GLubyte *) gl_dispatch_functions_end ) {
(void) memcpy( curr_func, get_disp, sizeof(run_time_patch));
curr_func += DISPATCH_FUNCTION_SIZE;
}
#endif
}
/**
* Generate a dispatch function (entrypoint) which jumps through
* the given slot number (offset) in the current dispatch table.
* We need assembly language in order to accomplish this.
*/
_glapi_proc
generate_entrypoint(unsigned int functionOffset)
{
/* 32 is chosen as something of a magic offset. For x86, the dispatch
* at offset 32 is the first one where the offset in the
* "jmp OFFSET*4(%eax)" can't be encoded in a single byte.
*/
const GLubyte * const template_func = gl_dispatch_functions_start
+ (DISPATCH_FUNCTION_SIZE * 32);
GLubyte * const code = (GLubyte *) u_execmem_alloc(DISPATCH_FUNCTION_SIZE);
if ( code != NULL ) {
(void) memcpy(code, template_func, DISPATCH_FUNCTION_SIZE);
fill_in_entrypoint_offset( (_glapi_proc) code, functionOffset );
}
return (_glapi_proc) code;
}
/**
* This function inserts a new dispatch offset into the assembly language
* stub that was generated with the preceeding function.
*/
void
fill_in_entrypoint_offset(_glapi_proc entrypoint, unsigned int offset)
{
GLubyte * const code = (GLubyte *) entrypoint;
*((unsigned int *)(code + 8)) = 4 * offset;
}
#elif defined(USE_SPARC_ASM)
extern void __glapi_sparc_icache_flush(unsigned int *);
static void
init_glapi_relocs( void )
{
static const unsigned int template[] = {
0x05000000, /* sethi %hi(_glapi_tls_Dispatch), %g2 */
0x8730e00a, /* srl %g3, 10, %g3 */
0x8410a000, /* or %g2, %lo(_glapi_tls_Dispatch), %g2 */
#ifdef __arch64__
0xc259c002, /* ldx [%g7 + %g2], %g1 */
0xc2584003, /* ldx [%g1 + %g3], %g1 */
#else
0xc201c002, /* ld [%g7 + %g2], %g1 */
0xc2004003, /* ld [%g1 + %g3], %g1 */
#endif
0x81c04000, /* jmp %g1 */
0x01000000, /* nop */
};
extern unsigned int __glapi_sparc_tls_stub;
extern unsigned long __glapi_sparc_get_dispatch(void);
unsigned int *code = &__glapi_sparc_tls_stub;
unsigned long dispatch = __glapi_sparc_get_dispatch();
code[0] = template[0] | (dispatch >> 10);
code[1] = template[1];
__glapi_sparc_icache_flush(&code[0]);
code[2] = template[2] | (dispatch & 0x3ff);
code[3] = template[3];
__glapi_sparc_icache_flush(&code[2]);
code[4] = template[4];
code[5] = template[5];
__glapi_sparc_icache_flush(&code[4]);
code[6] = template[6];
__glapi_sparc_icache_flush(&code[6]);
}
_glapi_proc
generate_entrypoint(GLuint functionOffset)
{
static const unsigned int template[] = {
0x07000000, /* sethi %hi(0), %g3 */
0x8210000f, /* mov %o7, %g1 */
0x40000000, /* call */
0x9e100001, /* mov %g1, %o7 */
};
extern unsigned int __glapi_sparc_tls_stub;
unsigned long call_dest = (unsigned long ) &__glapi_sparc_tls_stub;
unsigned int *code = (unsigned int *) u_execmem_alloc(sizeof(template));
if (code) {
code[0] = template[0] | (functionOffset & 0x3fffff);
code[1] = template[1];
__glapi_sparc_icache_flush(&code[0]);
code[2] = template[2] |
(((call_dest - ((unsigned long) &code[2]))
>> 2) & 0x3fffffff);
code[3] = template[3];
__glapi_sparc_icache_flush(&code[2]);
}
return (_glapi_proc) code;
}
void
fill_in_entrypoint_offset(_glapi_proc entrypoint, GLuint offset)
{
unsigned int *code = (unsigned int *) entrypoint;
code[0] &= ~0x3fffff;
code[0] |= (offset * sizeof(void *)) & 0x3fffff;
__glapi_sparc_icache_flush(&code[0]);
}
#else /* USE_*_ASM */
static void
init_glapi_relocs( void )
{
}
_glapi_proc
generate_entrypoint(GLuint functionOffset)
{
(void) functionOffset;
return NULL;
}
void
fill_in_entrypoint_offset(_glapi_proc entrypoint, GLuint offset)
{
/* an unimplemented architecture */
(void) entrypoint;
(void) offset;
}
#endif /* USE_*_ASM */
void
init_glapi_relocs_once( void )
{
static once_flag flag = ONCE_FLAG_INIT;
call_once(&flag, init_glapi_relocs);
}
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