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Let PageDirectory have a PhysicalPage for the PDB instead of being the PDB.

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This is more efficient than using the wasteful kmalloc_aligned() approach
to allocation. It also allows much tighter encapsulation of the class.
This commit is contained in:
Andreas Kling 2018-12-31 14:58:03 +01:00
parent 2239ab96e7
commit 193ead94f8
4 changed files with 122 additions and 100 deletions
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28
Kernel/MemoryManager.h
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@ -21,6 +21,7 @@ enum class PageFaultResponse {
class PhysicalPage {
friend class MemoryManager;
friend class PageDirectory;
public:
~PhysicalPage() { }
PhysicalAddress paddr() const { return m_paddr; }
@ -53,11 +54,20 @@ private:
};
class PageDirectory {
friend class MemoryManager;
public:
dword entries[1024];
RetainPtr<PhysicalPage> physical_pages[1024];
PageDirectory();
explicit PageDirectory(PhysicalAddress);
~PageDirectory();
dword cr3() const { return m_directory_page->paddr().get(); }
dword* entries() { return reinterpret_cast<dword*>(cr3()); }
bool is_active() const;
private:
RetainPtr<PhysicalPage> m_directory_page;
RetainPtr<PhysicalPage> m_physical_pages[1024];
};
class VMObject : public Retainable<VMObject> {
@ -148,6 +158,7 @@ public:
class MemoryManager {
AK_MAKE_ETERNAL
friend class PageDirectory;
friend class PhysicalPage;
friend class Region;
friend class VMObject;
@ -164,7 +175,6 @@ public:
bool unmap_region(Process&, Region&);
void populate_page_directory(PageDirectory&);
void release_page_directory(PageDirectory&);
byte* create_kernel_alias_for_region(Region&);
void remove_kernel_alias_for_region(Region&, byte*);
@ -189,9 +199,9 @@ private:
void unregister_region(Region&);
LinearAddress allocate_linear_address_range(size_t);
void map_region_at_address(PageDirectory*, Region&, LinearAddress, bool user_accessible);
void unmap_range(PageDirectory*, LinearAddress, size_t);
void remap_region_page(PageDirectory*, Region&, unsigned page_index_in_region, bool user_allowed);
void map_region_at_address(PageDirectory&, Region&, LinearAddress, bool user_accessible);
void unmap_range(PageDirectory&, LinearAddress, size_t);
void remap_region_page(PageDirectory&, Region&, unsigned page_index_in_region, bool user_allowed);
void initialize_paging();
void flush_entire_tlb();
@ -214,6 +224,8 @@ private:
byte* quickmap_page(PhysicalPage&);
void unquickmap_page();
PageDirectory& kernel_page_directory() { return *m_kernel_page_directory; }
struct PageDirectoryEntry {
explicit PageDirectoryEntry(dword* pde) : m_pde(pde) { }
@ -292,9 +304,9 @@ private:
dword* m_pte;
};
PageTableEntry ensure_pte(PageDirectory*, LinearAddress);
PageTableEntry ensure_pte(PageDirectory&, LinearAddress);
PageDirectory* m_kernel_page_directory;
OwnPtr<PageDirectory> m_kernel_page_directory;
dword* m_page_table_zero;
dword* m_page_table_one;