ladybird/Kernel/Memory/PageDirectory.h
Andreas Kling 2c72d495a3 Kernel: Use RefPtr instead of LockRefPtr for PhysicalPage
I believe this to be safe, as the main thing that LockRefPtr provides
over RefPtr is safe copying from a shared LockRefPtr instance. I've
inspected the uses of RefPtr<PhysicalPage> and it seems they're all
guarded by external locking. Some of it is less obvious, but this is
an area where we're making continuous headway.
2022-08-24 18:35:41 +02:00

81 lines
2.1 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/AtomicRefCounted.h>
#include <AK/Badge.h>
#include <AK/HashMap.h>
#include <AK/IntrusiveRedBlackTree.h>
#include <AK/RefPtr.h>
#include <Kernel/Forward.h>
#include <Kernel/Locking/Spinlock.h>
#include <Kernel/Memory/PhysicalPage.h>
namespace Kernel::Memory {
class PageDirectory final : public AtomicRefCounted<PageDirectory> {
friend class MemoryManager;
public:
static ErrorOr<NonnullLockRefPtr<PageDirectory>> try_create_for_userspace();
static NonnullLockRefPtr<PageDirectory> must_create_kernel_page_directory();
static LockRefPtr<PageDirectory> find_current();
~PageDirectory();
void allocate_kernel_directory();
FlatPtr cr3() const
{
#if ARCH(X86_64)
return m_pml4t->paddr().get();
#else
return m_directory_table->paddr().get();
#endif
}
bool is_cr3_initialized() const
{
#if ARCH(X86_64)
return m_pml4t;
#else
return m_directory_table;
#endif
}
AddressSpace* address_space() { return m_space; }
AddressSpace const* address_space() const { return m_space; }
void set_space(Badge<AddressSpace>, AddressSpace& space) { m_space = &space; }
RecursiveSpinlock& get_lock() { return m_lock; }
// This has to be public to let the global singleton access the member pointer
IntrusiveRedBlackTreeNode<FlatPtr, PageDirectory, RawPtr<PageDirectory>> m_tree_node;
private:
PageDirectory();
static void register_page_directory(PageDirectory* directory);
static void deregister_page_directory(PageDirectory* directory);
AddressSpace* m_space { nullptr };
#if ARCH(X86_64)
RefPtr<PhysicalPage> m_pml4t;
#endif
RefPtr<PhysicalPage> m_directory_table;
#if ARCH(X86_64)
RefPtr<PhysicalPage> m_directory_pages[512];
#else
RefPtr<PhysicalPage> m_directory_pages[4];
#endif
RecursiveSpinlock m_lock { LockRank::None };
};
void activate_kernel_page_directory(PageDirectory const& pgd);
void activate_page_directory(PageDirectory const& pgd, Thread* current_thread);
}