src/mapi/entry_ppc64le_tls.h

   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
  74 void
  75 entry_patch_public(void)
  76 {
  77 }
  78
  79 extern char
  80 ppc64le_entry_start[] HIDDEN;
  81
  82 mapi_func
  83 entry_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
  96 extern uint64_t ppc64le_dispatch_tls();
  97
  98 static 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 };
 123 static const uint64_t TEMPLATE_OFFSET_TLS_ADDR = sizeof(code_templ) - 2*8;
 124 static const uint64_t TEMPLATE_OFFSET_SLOT = sizeof(code_templ) - 1*8;
 125
 126 void
 127 entry_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
 134 mapi_func
 135 entry_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 */