mapi: Enable assembly language API acceleration for PPC64LE (V2)

Implement assembly language API acceleration for PPC64LE,
analogous to long-standing implementations for X86 and X86-64.

See also similar implementation in libglvnd.

Tested with Piglit.

Signed-off-by: Ben Crocker <[email protected]>
Acked-by: Emil Velikov <[email protected]>
Reviewed-by: Bill Schmidt <[email protected]>

1 files changed, 152 insertions, 0 deletions

diff --git a/src/mapi/entry_ppc64le_tls.h b/src/mapi/entry_ppc64le_tls.h
new file mode 100644
index 00000000000..e09a1178a06
--- /dev/null
+++ b/src/mapi/entry_ppc64le_tls.h
@@ -0,0 +1,152 @@
+/*
+ * Mesa 3-D graphics library
+ *
+ * Copyright (C) 2017 Red Hat
+ *
+ * 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.
+ *
+ * Authors:
+ *    Ben Crocker <[email protected]>
+ */
+
+#ifdef HAVE_FUNC_ATTRIBUTE_VISIBILITY
+#define HIDDEN __attribute__((visibility("hidden")))
+#else
+#define HIDDEN
+#endif
+
+// NOTE: These must be powers of two:
+#define PPC64LE_ENTRY_SIZE 64
+#define PPC64LE_PAGE_ALIGN 65536
+#if ((PPC64LE_ENTRY_SIZE & (PPC64LE_ENTRY_SIZE - 1)) != 0)
+#error PPC64LE_ENTRY_SIZE must be a power of two!
+#endif
+#if ((PPC64LE_PAGE_ALIGN & (PPC64LE_PAGE_ALIGN - 1)) != 0)
+#error PPC64LE_PAGE_ALIGN must be a power of two!
+#endif
+
+__asm__(".text\n"
+        ".balign " U_STRINGIFY(PPC64LE_ENTRY_SIZE) "\n"
+        "ppc64le_entry_start:");
+
+#define STUB_ASM_ENTRY(func)                            \
+   ".globl " func "\n"                                  \
+   ".type " func ", @function\n"                        \
+   ".balign " U_STRINGIFY(PPC64LE_ENTRY_SIZE) "\n"        \
+   func ":\n\t"                                         \
+   "  addis  2, 12, .TOC.-" func "@ha\n\t"              \
+   "  addi   2, 2, .TOC.-" func "@l\n\t"                \
+   "  .localentry  " func ", .-" func "\n\t"
+
+#define STUB_ASM_CODE(slot)                                     \
+   "  addis  11, 2, " ENTRY_CURRENT_TABLE "@got@tprel@ha\n\t"   \
+   "  ld     11, " ENTRY_CURRENT_TABLE "@got@tprel@l(11)\n\t"   \
+   "  add    11, 11," ENTRY_CURRENT_TABLE "@tls\n\t"            \
+   "  ld     11, 0(11)\n\t"                                     \
+   "  ld     12, " slot "*8(11)\n\t"                            \
+   "  mtctr  12\n\t"                                            \
+   "  bctr\n"                                                   \
+
+#define MAPI_TMP_STUB_ASM_GCC
+#include "mapi_tmp.h"
+
+#ifndef MAPI_MODE_BRIDGE
+
+#include <string.h>
+#include "u_execmem.h"
+
+void
+entry_patch_public(void)
+{
+}
+
+extern char
+ppc64le_entry_start[] HIDDEN;
+
+mapi_func
+entry_get_public(int slot)
+{
+   return (mapi_func) (ppc64le_entry_start + slot * PPC64LE_ENTRY_SIZE);
+}
+
+__asm__(".text\n");
+
+__asm__("ppc64le_dispatch_tls:\n\t"
+        "  addis  3, 2, " ENTRY_CURRENT_TABLE "@got@tprel@ha\n\t"
+        "  ld     3, " ENTRY_CURRENT_TABLE "@got@tprel@l(3)\n\t"
+        "  blr\n"
+        );
+
+extern uint64_t ppc64le_dispatch_tls();
+
+static const uint32_t code_templ[] = {
+   // This should be functionally the same code as would be generated from
+   // the STUB_ASM_CODE macro, but defined as a buffer.
+   // This is used to generate new dispatch stubs. Mesa will copy this
+   // data to the dispatch stub, and then it will patch the slot number and
+   // any addresses that it needs to.
+   // NOTE!!!  NOTE!!!  NOTE!!!
+   // This representation is correct for both little- and big-endian systems.
+   // However, more work needs to be done for big-endian Linux because it
+   // adheres to an older, AIX-compatible ABI that uses function descriptors.
+   // 1000:
+   0x7C0802A6,    // <ENTRY+00>:   mflr   0
+   0xF8010010,    // <ENTRY+04>:   std    0, 16(1)
+   0xE96C0028,    // <ENTRY+08>:   ld     11, 9000f-1000b+0(12)
+   0x7D6B6A14,    // <ENTRY+12>:   add    11, 11, 13
+   0xE96B0000,    // <ENTRY+16>:   ld     11, 0(11)
+   0xE80C0030,    // <ENTRY+20>:   ld     0, 9000f-1000b+8(12)
+   0x7D8B002A,    // <ENTRY+24>:   ldx    12, 11, 0
+   0x7D8903A6,    // <ENTRY+28>:   mtctr  12
+   0x4E800420,    // <ENTRY+32>:   bctr
+   0x60000000,    // <ENTRY+36>:   nop
+   // 9000:
+   0, 0,          // <ENTRY+40>:    .quad _glapi_tls_Dispatch
+   0, 0           // <ENTRY+48>:    .quad <slot>*8
+};
+static const uint64_t TEMPLATE_OFFSET_TLS_ADDR = sizeof(code_templ) - 2*8;
+static const uint64_t TEMPLATE_OFFSET_SLOT = sizeof(code_templ) - 1*8;
+
+void
+entry_patch(mapi_func entry, int slot)
+{
+   char *code = (char *) entry;
+   *((uint64_t *) (code + TEMPLATE_OFFSET_TLS_ADDR)) = ppc64le_dispatch_tls();
+   *((uint64_t *) (code + TEMPLATE_OFFSET_SLOT)) = slot * sizeof(mapi_func);
+}
+
+mapi_func
+entry_generate(int slot)
+{
+   char *code;
+   mapi_func entry;
+
+   code = u_execmem_alloc(sizeof(code_templ));
+   if (!code)
+      return NULL;
+
+   memcpy(code, code_templ, sizeof(code_templ));
+
+   entry = (mapi_func) code;
+   entry_patch(entry, slot);
+
+   return entry;
+}
+
+#endif /* MAPI_MODE_BRIDGE */