1 /*
2 * Copyright (c) 2017, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24 #include "precompiled.hpp"
25 #include "gc/z/zGlobals.hpp"
26 #include "runtime/globals.hpp"
27 #include "utilities/globalDefinitions.hpp"
28 #include "utilities/powerOfTwo.hpp"
29
30 //
31 // The heap can have three different layouts, depending on the max heap size.
32 //
33 // Address Space & Pointer Layout 1
34 // --------------------------------
35 //
36 // +--------------------------------+ 0x00007FFFFFFFFFFF (127TB)
37 // . .
38 // . .
39 // . .
40 // +--------------------------------+ 0x0000014000000000 (20TB)
41 // | Remapped View |
42 // +--------------------------------+ 0x0000010000000000 (16TB)
43 // . .
44 // +--------------------------------+ 0x00000c0000000000 (12TB)
45 // | Marked1 View |
46 // +--------------------------------+ 0x0000080000000000 (8TB)
47 // | Marked0 View |
48 // +--------------------------------+ 0x0000040000000000 (4TB)
49 // . .
50 // +--------------------------------+ 0x0000000000000000
51 //
52 // 6 4 4 4 4
53 // 3 6 5 2 1 0
54 // +--------------------+----+-----------------------------------------------+
55 // |00000000 00000000 00|1111|11 11111111 11111111 11111111 11111111 11111111|
56 // +--------------------+----+-----------------------------------------------+
57 // | | |
58 // | | * 41-0 Object Offset (42-bits, 4TB address space)
59 // | |
60 // | * 45-42 Metadata Bits (4-bits) 0001 = Marked0 (Address view 4-8TB)
61 // | 0010 = Marked1 (Address view 8-12TB)
62 // | 0100 = Remapped (Address view 16-20TB)
63 // | 1000 = Finalizable (Address view N/A)
64 // |
65 // * 63-46 Fixed (18-bits, always zero)
66 //
67 //
68 // Address Space & Pointer Layout 2
69 // --------------------------------
70 //
71 // +--------------------------------+ 0x00007FFFFFFFFFFF (127TB)
72 // . .
73 // . .
74 // . .
75 // +--------------------------------+ 0x0000280000000000 (40TB)
76 // | Remapped View |
77 // +--------------------------------+ 0x0000200000000000 (32TB)
78 // . .
79 // +--------------------------------+ 0x0000180000000000 (24TB)
80 // | Marked1 View |
81 // +--------------------------------+ 0x0000100000000000 (16TB)
82 // | Marked0 View |
83 // +--------------------------------+ 0x0000080000000000 (8TB)
84 // . .
85 // +--------------------------------+ 0x0000000000000000
86 //
87 // 6 4 4 4 4
88 // 3 7 6 3 2 0
89 // +------------------+-----+------------------------------------------------+
90 // |00000000 00000000 0|1111|111 11111111 11111111 11111111 11111111 11111111|
91 // +-------------------+----+------------------------------------------------+
92 // | | |
93 // | | * 42-0 Object Offset (43-bits, 8TB address space)
94 // | |
95 // | * 46-43 Metadata Bits (4-bits) 0001 = Marked0 (Address view 8-16TB)
96 // | 0010 = Marked1 (Address view 16-24TB)
97 // | 0100 = Remapped (Address view 32-40TB)
98 // | 1000 = Finalizable (Address view N/A)
99 // |
100 // * 63-47 Fixed (17-bits, always zero)
101 //
102 //
103 // Address Space & Pointer Layout 3
104 // --------------------------------
105 //
106 // +--------------------------------+ 0x00007FFFFFFFFFFF (127TB)
107 // . .
108 // . .
109 // . .
110 // +--------------------------------+ 0x0000500000000000 (80TB)
111 // | Remapped View |
112 // +--------------------------------+ 0x0000400000000000 (64TB)
113 // . .
114 // +--------------------------------+ 0x0000300000000000 (48TB)
115 // | Marked1 View |
116 // +--------------------------------+ 0x0000200000000000 (32TB)
117 // | Marked0 View |
118 // +--------------------------------+ 0x0000100000000000 (16TB)
119 // . .
120 // +--------------------------------+ 0x0000000000000000
121 //
122 // 6 4 4 4 4
123 // 3 8 7 4 3 0
124 // +------------------+----+-------------------------------------------------+
125 // |00000000 00000000 |1111|1111 11111111 11111111 11111111 11111111 11111111|
126 // +------------------+----+-------------------------------------------------+
127 // | | |
128 // | | * 43-0 Object Offset (44-bits, 16TB address space)
129 // | |
130 // | * 47-44 Metadata Bits (4-bits) 0001 = Marked0 (Address view 16-32TB)
131 // | 0010 = Marked1 (Address view 32-48TB)
132 // | 0100 = Remapped (Address view 64-80TB)
133 // | 1000 = Finalizable (Address view N/A)
134 // |
135 // * 63-48 Fixed (16-bits, always zero)
136 //
137
138 size_t ZPlatformAddressOffsetBits() {
139 // 42 VA_BITS uses 64K pages
140 // 47 VA_BITS uses 16K pages - default mode
141 const bool is_using_42_va_bits = os::vm_page_size() == (64 * 1024);
142 const bool is_using_47_va_bits = os::vm_page_size() == (16 * 1024);
143
144 assert(is_using_42_va_bits ^ is_using_47_va_bits, "One mode should be set");
145
146 const int va_bits = is_using_42_va_bits ? 42 : 47;
147
148 // The max_address_offset_bits need to contain 5 full offsets:
149 //
150 // Remapped
151 // Gap
152 // Marked1
153 // Marked0
154 // Base
155 //
156 // Which uses 3 of the available bits
157 const size_t max_address_offset_bits = va_bits - 3;
158
159 // Don't unnecessarily overuse the virtual address space
160 const size_t min_address_offset_bits = max_address_offset_bits - 2;
161
162 const size_t address_offset = round_up_power_of_2(MaxHeapSize * ZVirtualToPhysicalRatio);
163 const size_t address_offset_bits = log2_intptr(address_offset);
164 return clamp(address_offset_bits, min_address_offset_bits, max_address_offset_bits);
165 }
166
167 size_t ZPlatformAddressMetadataShift() {
168 return ZPlatformAddressOffsetBits();
169 }