1/*
2 * Mesa 3-D graphics library
3 *
4 * Copyright (C) 2017 Red Hat
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 OR
17 * 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 OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
22 * DEALINGS IN THE SOFTWARE.
23 *
24 * Authors:
25 *    Ben Crocker <bcrocker@redhat.com>
26 */
27
28#ifdef HAVE_FUNC_ATTRIBUTE_VISIBILITY
29#define HIDDEN __attribute__((visibility("hidden")))
30#else
31#define HIDDEN
32#endif
33
34// NOTE: These must be powers of two:
35#define PPC64LE_ENTRY_SIZE 64
36#define PPC64LE_PAGE_ALIGN 65536
37#if ((PPC64LE_ENTRY_SIZE & (PPC64LE_ENTRY_SIZE - 1)) != 0)
38#error PPC64LE_ENTRY_SIZE must be a power of two!
39#endif
40#if ((PPC64LE_PAGE_ALIGN & (PPC64LE_PAGE_ALIGN - 1)) != 0)
41#error PPC64LE_PAGE_ALIGN must be a power of two!
42#endif
43
44__asm__(".text\n"
45        ".balign " U_STRINGIFY(PPC64LE_ENTRY_SIZE) "\n"
46        "ppc64le_entry_start:");
47
48#define STUB_ASM_ENTRY(func)                            \
49   ".globl " func "\n"                                  \
50   ".type " func ", @function\n"                        \
51   ".balign " U_STRINGIFY(PPC64LE_ENTRY_SIZE) "\n"        \
52   func ":\n\t"                                         \
53   "  addis  2, 12, .TOC.-" func "@ha\n\t"              \
54   "  addi   2, 2, .TOC.-" func "@l\n\t"                \
55   "  .localentry  " func ", .-" func "\n\t"
56
57#define STUB_ASM_CODE(slot)                                     \
58   "  addis  11, 2, " ENTRY_CURRENT_TABLE "@got@tprel@ha\n\t"   \
59   "  ld     11, " ENTRY_CURRENT_TABLE "@got@tprel@l(11)\n\t"   \
60   "  add    11, 11," ENTRY_CURRENT_TABLE "@tls\n\t"            \
61   "  ld     11, 0(11)\n\t"                                     \
62   "  ld     12, " slot "*8(11)\n\t"                            \
63   "  mtctr  12\n\t"                                            \
64   "  bctr\n"                                                   \
65
66#define MAPI_TMP_STUB_ASM_GCC
67#include "mapi_tmp.h"
68
69#ifndef MAPI_MODE_BRIDGE
70
71#include <string.h>
72#include "u_execmem.h"
73
74void
75entry_patch_public(void)
76{
77}
78
79extern char
80ppc64le_entry_start[] HIDDEN;
81
82mapi_func
83entry_get_public(int slot)
84{
85   return (mapi_func) (ppc64le_entry_start + slot * PPC64LE_ENTRY_SIZE);
86}
87
88__asm__(".text\n");
89
90__asm__("ppc64le_dispatch_tls:\n\t"
91        "  addis  3, 2, " ENTRY_CURRENT_TABLE "@got@tprel@ha\n\t"
92        "  ld     3, " ENTRY_CURRENT_TABLE "@got@tprel@l(3)\n\t"
93        "  blr\n"
94        );
95
96extern uint64_t ppc64le_dispatch_tls();
97
98static const uint32_t code_templ[] = {
99   // This should be functionally the same code as would be generated from
100   // the STUB_ASM_CODE macro, but defined as a buffer.
101   // This is used to generate new dispatch stubs. Mesa will copy this
102   // data to the dispatch stub, and then it will patch the slot number and
103   // any addresses that it needs to.
104   // NOTE!!!  NOTE!!!  NOTE!!!
105   // This representation is correct for both little- and big-endian systems.
106   // However, more work needs to be done for big-endian Linux because it
107   // adheres to an older, AIX-compatible ABI that uses function descriptors.
108   // 1000:
109   0x7C0802A6,    // <ENTRY+00>:   mflr   0
110   0xF8010010,    // <ENTRY+04>:   std    0, 16(1)
111   0xE96C0028,    // <ENTRY+08>:   ld     11, 9000f-1000b+0(12)
112   0x7D6B6A14,    // <ENTRY+12>:   add    11, 11, 13
113   0xE96B0000,    // <ENTRY+16>:   ld     11, 0(11)
114   0xE80C0030,    // <ENTRY+20>:   ld     0, 9000f-1000b+8(12)
115   0x7D8B002A,    // <ENTRY+24>:   ldx    12, 11, 0
116   0x7D8903A6,    // <ENTRY+28>:   mtctr  12
117   0x4E800420,    // <ENTRY+32>:   bctr
118   0x60000000,    // <ENTRY+36>:   nop
119   // 9000:
120   0, 0,          // <ENTRY+40>:    .quad _glapi_tls_Dispatch
121   0, 0           // <ENTRY+48>:    .quad <slot>*8
122};
123static const uint64_t TEMPLATE_OFFSET_TLS_ADDR = sizeof(code_templ) - 2*8;
124static const uint64_t TEMPLATE_OFFSET_SLOT = sizeof(code_templ) - 1*8;
125
126void
127entry_patch(mapi_func entry, int slot)
128{
129   char *code = (char *) entry;
130   *((uint64_t *) (code + TEMPLATE_OFFSET_TLS_ADDR)) = ppc64le_dispatch_tls();
131   *((uint64_t *) (code + TEMPLATE_OFFSET_SLOT)) = slot * sizeof(mapi_func);
132}
133
134mapi_func
135entry_generate(int slot)
136{
137   char *code;
138   mapi_func entry;
139
140   code = u_execmem_alloc(sizeof(code_templ));
141   if (!code)
142      return NULL;
143
144   memcpy(code, code_templ, sizeof(code_templ));
145
146   entry = (mapi_func) code;
147   entry_patch(entry, slot);
148
149   return entry;
150}
151
152#endif /* MAPI_MODE_BRIDGE */
153