1/*
2 * Mesa 3-D graphics library
3 *
4 * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included
14 * in all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22 * OTHER DEALINGS IN THE SOFTWARE.
23 */
24
25/**
26 * \file glapi_entrypoint.c
27 *
28 * Arch-specific code for manipulating GL API entrypoints (dispatch stubs).
29 */
30
31
32#include <string.h>
33
34#include "c11/threads.h"
35#include "glapi/glapi_priv.h"
36#include "u_execmem.h"
37
38
39#ifdef USE_X86_ASM
40
41extern       GLubyte gl_dispatch_functions_start[];
42extern       GLubyte gl_dispatch_functions_end[];
43
44#endif /* USE_X86_ASM */
45
46
47#if defined(DISPATCH_FUNCTION_SIZE)
48
49_glapi_proc
50get_entrypoint_address(unsigned int functionOffset)
51{
52   return (_glapi_proc) (gl_dispatch_functions_start
53                         + (DISPATCH_FUNCTION_SIZE * functionOffset));
54}
55
56#endif
57
58
59#if defined(USE_X86_ASM)
60
61/**
62 * Perform platform-specific GL API entry-point fixups.
63 */
64static void
65init_glapi_relocs( void )
66{
67#if !defined(GLX_X86_READONLY_TEXT)
68    extern unsigned long _x86_get_dispatch(void);
69    char run_time_patch[] = {
70       0x65, 0xa1, 0, 0, 0, 0 /* movl %gs:0,%eax */
71    };
72    GLuint *offset = (GLuint *) &run_time_patch[2]; /* 32-bits for x86/32 */
73    const GLubyte * const get_disp = (const GLubyte *) run_time_patch;
74    GLubyte * curr_func = (GLubyte *) gl_dispatch_functions_start;
75
76    *offset = _x86_get_dispatch();
77    while ( curr_func != (GLubyte *) gl_dispatch_functions_end ) {
78	(void) memcpy( curr_func, get_disp, sizeof(run_time_patch));
79	curr_func += DISPATCH_FUNCTION_SIZE;
80    }
81#endif
82}
83
84
85/**
86 * Generate a dispatch function (entrypoint) which jumps through
87 * the given slot number (offset) in the current dispatch table.
88 * We need assembly language in order to accomplish this.
89 */
90_glapi_proc
91generate_entrypoint(unsigned int functionOffset)
92{
93   /* 32 is chosen as something of a magic offset.  For x86, the dispatch
94    * at offset 32 is the first one where the offset in the
95    * "jmp OFFSET*4(%eax)" can't be encoded in a single byte.
96    */
97   const GLubyte * const template_func = gl_dispatch_functions_start
98     + (DISPATCH_FUNCTION_SIZE * 32);
99   GLubyte * const code = (GLubyte *) u_execmem_alloc(DISPATCH_FUNCTION_SIZE);
100
101
102   if ( code != NULL ) {
103      (void) memcpy(code, template_func, DISPATCH_FUNCTION_SIZE);
104      fill_in_entrypoint_offset( (_glapi_proc) code, functionOffset );
105   }
106
107   return (_glapi_proc) code;
108}
109
110
111/**
112 * This function inserts a new dispatch offset into the assembly language
113 * stub that was generated with the preceeding function.
114 */
115void
116fill_in_entrypoint_offset(_glapi_proc entrypoint, unsigned int offset)
117{
118   GLubyte * const code = (GLubyte *) entrypoint;
119
120   *((unsigned int *)(code +  8)) = 4 * offset;
121}
122
123
124#elif defined(USE_SPARC_ASM)
125
126extern void __glapi_sparc_icache_flush(unsigned int *);
127
128static void
129init_glapi_relocs( void )
130{
131    static const unsigned int template[] = {
132	0x05000000, /* sethi %hi(_glapi_tls_Dispatch), %g2 */
133	0x8730e00a, /* srl %g3, 10, %g3 */
134	0x8410a000, /* or %g2, %lo(_glapi_tls_Dispatch), %g2 */
135#ifdef __arch64__
136	0xc259c002, /* ldx [%g7 + %g2], %g1 */
137	0xc2584003, /* ldx [%g1 + %g3], %g1 */
138#else
139	0xc201c002, /* ld [%g7 + %g2], %g1 */
140	0xc2004003, /* ld [%g1 + %g3], %g1 */
141#endif
142	0x81c04000, /* jmp %g1 */
143	0x01000000, /* nop  */
144    };
145    extern unsigned int __glapi_sparc_tls_stub;
146    extern unsigned long __glapi_sparc_get_dispatch(void);
147    unsigned int *code = &__glapi_sparc_tls_stub;
148    unsigned long dispatch = __glapi_sparc_get_dispatch();
149
150    code[0] = template[0] | (dispatch >> 10);
151    code[1] = template[1];
152    __glapi_sparc_icache_flush(&code[0]);
153    code[2] = template[2] | (dispatch & 0x3ff);
154    code[3] = template[3];
155    __glapi_sparc_icache_flush(&code[2]);
156    code[4] = template[4];
157    code[5] = template[5];
158    __glapi_sparc_icache_flush(&code[4]);
159    code[6] = template[6];
160    __glapi_sparc_icache_flush(&code[6]);
161}
162
163
164_glapi_proc
165generate_entrypoint(GLuint functionOffset)
166{
167   static const unsigned int template[] = {
168      0x07000000, /* sethi %hi(0), %g3 */
169      0x8210000f, /* mov  %o7, %g1 */
170      0x40000000, /* call */
171      0x9e100001, /* mov  %g1, %o7 */
172   };
173   extern unsigned int __glapi_sparc_tls_stub;
174   unsigned long call_dest = (unsigned long ) &__glapi_sparc_tls_stub;
175   unsigned int *code = (unsigned int *) u_execmem_alloc(sizeof(template));
176   if (code) {
177      code[0] = template[0] | (functionOffset & 0x3fffff);
178      code[1] = template[1];
179      __glapi_sparc_icache_flush(&code[0]);
180      code[2] = template[2] |
181         (((call_dest - ((unsigned long) &code[2]))
182	   >> 2) & 0x3fffffff);
183      code[3] = template[3];
184      __glapi_sparc_icache_flush(&code[2]);
185   }
186   return (_glapi_proc) code;
187}
188
189
190void
191fill_in_entrypoint_offset(_glapi_proc entrypoint, GLuint offset)
192{
193   unsigned int *code = (unsigned int *) entrypoint;
194
195   code[0] &= ~0x3fffff;
196   code[0] |= (offset * sizeof(void *)) & 0x3fffff;
197   __glapi_sparc_icache_flush(&code[0]);
198}
199
200
201#else /* USE_*_ASM */
202
203static void
204init_glapi_relocs( void )
205{
206}
207
208
209_glapi_proc
210generate_entrypoint(GLuint functionOffset)
211{
212   (void) functionOffset;
213   return NULL;
214}
215
216
217void
218fill_in_entrypoint_offset(_glapi_proc entrypoint, GLuint offset)
219{
220   /* an unimplemented architecture */
221   (void) entrypoint;
222   (void) offset;
223}
224
225#endif /* USE_*_ASM */
226
227
228void
229init_glapi_relocs_once( void )
230{
231   static once_flag flag = ONCE_FLAG_INIT;
232   call_once(&flag, init_glapi_relocs);
233}
234