ladybird/Kernel/VM/PhysicalPage.cpp
Tom c1006a3689 Kernel: Return an already destructed PhysicalPage to the allocators
By making sure the PhysicalPage instance is fully destructed the
allocators will have a chance to reclaim the PhysicalPageEntry for
free-list purposes. Just pass them the physical address of the page
that was freed, which is enough to lookup the PhysicalPageEntry later.
2021-07-08 11:43:34 +02:00

48 lines
1.2 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/Heap/kmalloc.h>
#include <Kernel/VM/MemoryManager.h>
#include <Kernel/VM/PhysicalPage.h>
namespace Kernel {
NonnullRefPtr<PhysicalPage> PhysicalPage::create(PhysicalAddress paddr, bool supervisor, bool may_return_to_freelist)
{
auto& physical_page_entry = MM.get_physical_page_entry(paddr);
return adopt_ref(*new (&physical_page_entry.physical_page) PhysicalPage(supervisor, may_return_to_freelist));
}
PhysicalPage::PhysicalPage(bool supervisor, bool may_return_to_freelist)
: m_may_return_to_freelist(may_return_to_freelist)
, m_supervisor(supervisor)
{
}
PhysicalAddress PhysicalPage::paddr() const
{
return MM.get_physical_address(*this);
}
void PhysicalPage::free_this()
{
if (m_may_return_to_freelist) {
auto paddr = MM.get_physical_address(*this);
bool is_supervisor = m_supervisor;
this->~PhysicalPage(); // delete in place
if (is_supervisor)
MM.deallocate_supervisor_physical_page(paddr);
else
MM.deallocate_user_physical_page(paddr);
} else {
this->~PhysicalPage(); // delete in place
}
}
}