1 /* |
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2 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. |
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8 * |
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9 * This code is distributed in the hope that it will be useful, but WITHOUT |
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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12 * version 2 for more details (a copy is included in the LICENSE file that |
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13 * accompanied this code). |
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14 * |
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15 * You should have received a copy of the GNU General Public License version |
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16 * 2 along with this work; if not, write to the Free Software Foundation, |
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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18 * |
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
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22 */ |
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23 |
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24 #ifndef SHARE_GC_Z_ZPAGETABLEENTRY_HPP |
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25 #define SHARE_GC_Z_ZPAGETABLEENTRY_HPP |
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26 |
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27 #include "gc/z/zBitField.hpp" |
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28 #include "memory/allocation.hpp" |
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29 |
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30 // |
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31 // Page table entry layout |
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32 // ----------------------- |
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33 // |
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34 // 6 |
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35 // 3 1 0 |
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36 // +----------------------------------------------------------------------+-+ |
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37 // |11111111 11111111 11111111 11111111 11111111 11111111 11111111 1111111|1| |
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38 // +----------------------------------------------------------------------+-+ |
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39 // | | |
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40 // | 0-0 Relocating Flag (1-bit) * |
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41 // | |
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42 // | |
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43 // | |
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44 // * 63-1 Page address (63-bits) |
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45 // |
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46 |
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47 class ZPage; |
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48 |
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49 class ZPageTableEntry { |
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50 private: |
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51 typedef ZBitField<uint64_t, bool, 0, 1> field_relocating; |
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52 typedef ZBitField<uint64_t, ZPage*, 1, 63, 1> field_page; |
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53 |
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54 uint64_t _entry; |
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55 |
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56 public: |
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57 ZPageTableEntry() : |
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58 _entry(0) {} |
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59 |
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60 ZPageTableEntry(ZPage* page, bool relocating) : |
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61 _entry(field_page::encode(page) | |
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62 field_relocating::encode(relocating)) {} |
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63 |
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64 bool relocating() const { |
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65 return field_relocating::decode(_entry); |
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66 } |
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67 |
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68 ZPage* page() const { |
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69 return field_page::decode(_entry); |
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70 } |
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71 }; |
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72 |
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73 #endif // SHARE_GC_Z_ZPAGETABLEENTRY_HPP |
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