1 /*
   2  * Copyright (c) 2015, 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/zAddress.inline.hpp"
  26 #include "gc/z/zPage.inline.hpp"
  27 #include "gc/z/zPageTable.inline.hpp"
  28 #include "runtime/orderAccess.hpp"
  29 #include "utilities/debug.hpp"
  30 
  31 ZPageTable::ZPageTable() :
  32     _map() {}
  33 
  34 ZPageTableEntry ZPageTable::get_entry(ZPage* page) const {
  35   const uintptr_t addr = ZAddress::good(page->start());
  36   return _map.get(addr);
  37 }
  38 
  39 void ZPageTable::put_entry(ZPage* page, ZPageTableEntry entry) {
  40   // Make sure a newly created page is globally visible before
  41   // updating the pagetable.
  42   OrderAccess::storestore();
  43 
  44   const uintptr_t start = ZAddress::good(page->start());
  45   const uintptr_t end = start + page->size();
  46   for (uintptr_t addr = start; addr < end; addr += ZGranuleSize) {
  47     _map.put(addr, entry);
  48   }
  49 }
  50 
  51 void ZPageTable::insert(ZPage* page) {
  52   assert(get_entry(page).page() == NULL ||
  53          get_entry(page).page() == page, "Invalid entry");
  54 
  55   // Cached pages stays in the pagetable and we must not re-insert
  56   // those when they get re-allocated because they might also be
  57   // relocating and we don't want to clear their relocating bit.
  58   if (get_entry(page).page() == NULL) {
  59     ZPageTableEntry entry(page, false /* relocating */);
  60     put_entry(page, entry);
  61   }
  62 
  63   assert(get_entry(page).page() == page, "Invalid entry");
  64 }
  65 
  66 void ZPageTable::remove(ZPage* page) {
  67   assert(get_entry(page).page() == page, "Invalid entry");
  68 
  69   ZPageTableEntry entry;
  70   put_entry(page, entry);
  71 
  72   assert(get_entry(page).page() == NULL, "Invalid entry");
  73 }
  74 
  75 void ZPageTable::set_relocating(ZPage* page) {
  76   assert(get_entry(page).page() == page, "Invalid entry");
  77   assert(!get_entry(page).relocating(), "Invalid entry");
  78 
  79   ZPageTableEntry entry(page, true /* relocating */);
  80   put_entry(page, entry);
  81 
  82   assert(get_entry(page).page() == page, "Invalid entry");
  83   assert(get_entry(page).relocating(), "Invalid entry");
  84 }
  85 
  86 void ZPageTable::clear_relocating(ZPage* page) {
  87   assert(get_entry(page).page() == page, "Invalid entry");
  88   assert(get_entry(page).relocating(), "Invalid entry");
  89 
  90   ZPageTableEntry entry(page, false /* relocating */);
  91   put_entry(page, entry);
  92 
  93   assert(get_entry(page).page() == page, "Invalid entry");
  94   assert(!get_entry(page).relocating(), "Invalid entry");
  95 }