src/hotspot/os_cpu/linux_aarch64/gc/z/zGlobals_linux_aarch64.cpp
author smonteith
Thu, 13 Jun 2019 15:24:34 +0100
changeset 55379 865775b86780
permissions -rw-r--r--
8214527: ZGC for Aarch64 Summary: Implement ZGC for AArch64 Reviewed-by: aph, pliden, eosterlund, rkennke, shade, njian, adinn

/*
 * Copyright (c) 2017, 2019, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

#include "precompiled.hpp"
#include "gc/z/zGlobals.hpp"
#include "gc/z/zUtils.inline.hpp"
#include "runtime/globals.hpp"
#include "utilities/globalDefinitions.hpp"

//
// The heap can have three different layouts, depending on the max heap size.
//
// Address Space & Pointer Layout 1
// --------------------------------
//
//  +--------------------------------+ 0x00007FFFFFFFFFFF (127TB)
//  .                                .
//  .                                .
//  .                                .
//  +--------------------------------+ 0x0000014000000000 (20TB)
//  |         Remapped View          |
//  +--------------------------------+ 0x0000010000000000 (16TB)
//  |     (Reserved, but unused)     |
//  +--------------------------------+ 0x00000c0000000000 (12TB)
//  |         Marked1 View           |
//  +--------------------------------+ 0x0000080000000000 (8TB)
//  |         Marked0 View           |
//  +--------------------------------+ 0x0000040000000000 (4TB)
//  .                                .
//  +--------------------------------+ 0x0000000000000000
//
//   6                  4 4  4 4
//   3                  6 5  2 1                                             0
//  +--------------------+----+-----------------------------------------------+
//  |00000000 00000000 00|1111|11 11111111 11111111 11111111 11111111 11111111|
//  +--------------------+----+-----------------------------------------------+
//  |                    |    |
//  |                    |    * 41-0 Object Offset (42-bits, 4TB address space)
//  |                    |
//  |                    * 45-42 Metadata Bits (4-bits)  0001 = Marked0      (Address view 4-8TB)
//  |                                                    0010 = Marked1      (Address view 8-12TB)
//  |                                                    0100 = Remapped     (Address view 16-20TB)
//  |                                                    1000 = Finalizable  (Address view N/A)
//  |
//  * 63-46 Fixed (18-bits, always zero)
//
//
// Address Space & Pointer Layout 2
// --------------------------------
//
//  +--------------------------------+ 0x00007FFFFFFFFFFF (127TB)
//  .                                .
//  .                                .
//  .                                .
//  +--------------------------------+ 0x0000280000000000 (40TB)
//  |         Remapped View          |
//  +--------------------------------+ 0x0000200000000000 (32TB)
//  |     (Reserved, but unused)     |
//  +--------------------------------+ 0x0000180000000000 (24TB)
//  |         Marked1 View           |
//  +--------------------------------+ 0x0000100000000000 (16TB)
//  |         Marked0 View           |
//  +--------------------------------+ 0x0000080000000000 (8TB)
//  .                                .
//  +--------------------------------+ 0x0000000000000000
//
//   6                 4 4  4 4
//   3                 7 6  3 2                                              0
//  +------------------+-----+------------------------------------------------+
//  |00000000 00000000 0|1111|111 11111111 11111111 11111111 11111111 11111111|
//  +-------------------+----+------------------------------------------------+
//  |                   |    |
//  |                   |    * 42-0 Object Offset (43-bits, 8TB address space)
//  |                   |
//  |                   * 46-43 Metadata Bits (4-bits)  0001 = Marked0      (Address view 8-16TB)
//  |                                                   0010 = Marked1      (Address view 16-24TB)
//  |                                                   0100 = Remapped     (Address view 32-40TB)
//  |                                                   1000 = Finalizable  (Address view N/A)
//  |
//  * 63-47 Fixed (17-bits, always zero)
//
//
// Address Space & Pointer Layout 3
// --------------------------------
//
//  +--------------------------------+ 0x00007FFFFFFFFFFF (127TB)
//  .                                .
//  .                                .
//  .                                .
//  +--------------------------------+ 0x0000500000000000 (80TB)
//  |         Remapped View          |
//  +--------------------------------+ 0x0000400000000000 (64TB)
//  |     (Reserved, but unused)     |
//  +--------------------------------+ 0x0000300000000000 (48TB)
//  |         Marked1 View           |
//  +--------------------------------+ 0x0000200000000000 (32TB)
//  |         Marked0 View           |
//  +--------------------------------+ 0x0000100000000000 (16TB)
//  .                                .
//  +--------------------------------+ 0x0000000000000000
//
//   6               4  4  4 4
//   3               8  7  4 3                                               0
//  +------------------+----+-------------------------------------------------+
//  |00000000 00000000 |1111|1111 11111111 11111111 11111111 11111111 11111111|
//  +------------------+----+-------------------------------------------------+
//  |                  |    |
//  |                  |    * 43-0 Object Offset (44-bits, 16TB address space)
//  |                  |
//  |                  * 47-44 Metadata Bits (4-bits)  0001 = Marked0      (Address view 16-32TB)
//  |                                                  0010 = Marked1      (Address view 32-48TB)
//  |                                                  0100 = Remapped     (Address view 64-80TB)
//  |                                                  1000 = Finalizable  (Address view N/A)
//  |
//  * 63-48 Fixed (16-bits, always zero)
//

uintptr_t ZPlatformAddressSpaceStart() {
  const uintptr_t first_heap_view_address = (uintptr_t)1 << (ZPlatformAddressMetadataShift() + 0);
  const size_t min_address_offset = 0;
  return first_heap_view_address + min_address_offset;
}

uintptr_t ZPlatformAddressSpaceEnd() {
  const uintptr_t last_heap_view_address = (uintptr_t)1 << (ZPlatformAddressMetadataShift() + 2);
  const size_t max_address_offset = (size_t)1 << ZPlatformAddressOffsetBits();
  return last_heap_view_address + max_address_offset;
}

uintptr_t ZPlatformAddressReservedStart() {
  return ZPlatformAddressSpaceStart();
}

uintptr_t ZPlatformAddressReservedEnd() {
  return ZPlatformAddressSpaceEnd();
}

uintptr_t ZPlatformAddressBase() {
  return 0;
}

size_t ZPlatformAddressOffsetBits() {
  const size_t min_address_offset_bits = 42; // 4TB
  const size_t max_address_offset_bits = 44; // 16TB
  const size_t virtual_to_physical_ratio = 7; // 7:1
  const size_t address_offset = ZUtils::round_up_power_of_2(MaxHeapSize * virtual_to_physical_ratio);
  const size_t address_offset_bits = log2_intptr(address_offset);
  return MIN2(MAX2(address_offset_bits, min_address_offset_bits), max_address_offset_bits);
}

size_t ZPlatformAddressMetadataShift() {
  return ZPlatformAddressOffsetBits();
}