text: /*
   * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * 1. Redistributions of source code must retain the above copyright notice, this
   *    list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright notice,
   *    this list of conditions and the following disclaimer in the documentation
   *    and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include <Kernel/VM/MemoryManager.h>
  #include <Kernel/VM/PhysicalPage.h>
  #include <Kernel/Heap/kmalloc.h>
  
  namespace Kernel {
  
  NonnullRefPtr<PhysicalPage> PhysicalPage::create(PhysicalAddress paddr, bool supervisor, bool may_return_to_freelist)
  {
      return adopt(*new PhysicalPage(paddr, supervisor, may_return_to_freelist));
  }
  
  PhysicalPage::PhysicalPage(PhysicalAddress paddr, bool supervisor, bool may_return_to_freelist)
      : m_may_return_to_freelist(may_return_to_freelist)
      , m_supervisor(supervisor)
      , m_paddr(paddr)
  {
  }
  
  void PhysicalPage::return_to_freelist() &&
  {
      ASSERT((paddr().get() & ~PAGE_MASK) == 0);
  
      InterruptDisabler disabler;
  
      m_ref_count = 1;
  
      if (m_supervisor)
          MM.deallocate_supervisor_physical_page(move(*this));
      else
          MM.deallocate_user_physical_page(move(*this));
  
  #ifdef MM_DEBUG
      dbgprintf("MM: P%x released to freelist\n", m_paddr.get());
  #endif
  }
  
  }
  