diff options
Diffstat (limited to 'Kernel/VM/MemoryManager.h')
| -rw-r--r-- | Kernel/VM/MemoryManager.h | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/Kernel/VM/MemoryManager.h b/Kernel/VM/MemoryManager.h new file mode 100644 index 0000000000..b33ae2605f --- /dev/null +++ b/Kernel/VM/MemoryManager.h @@ -0,0 +1,227 @@ +#pragma once + +#include "types.h" +#include "i386.h" +#include <AK/Bitmap.h> +#include <AK/ByteBuffer.h> +#include <AK/Retainable.h> +#include <AK/RetainPtr.h> +#include <AK/Vector.h> +#include <AK/HashTable.h> +#include <AK/AKString.h> +#include <AK/Badge.h> +#include <AK/Weakable.h> +#include <Kernel/VM/PhysicalPage.h> +#include <Kernel/VM/Region.h> +#include <Kernel/VM/VMObject.h> +#include <Kernel/FileSystem/InodeIdentifier.h> + +#define PAGE_ROUND_UP(x) ((((dword)(x)) + PAGE_SIZE-1) & (~(PAGE_SIZE-1))) + +class SynthFSInode; + +enum class PageFaultResponse { + ShouldCrash, + Continue, +}; + +#define MM MemoryManager::the() + +class MemoryManager { + AK_MAKE_ETERNAL + friend class PageDirectory; + friend class PhysicalPage; + friend class Region; + friend class VMObject; + friend ByteBuffer procfs$mm(InodeIdentifier); + friend ByteBuffer procfs$memstat(InodeIdentifier); +public: + [[gnu::pure]] static MemoryManager& the(); + + static void initialize(); + + PageFaultResponse handle_page_fault(const PageFault&); + + bool map_region(Process&, Region&); + bool unmap_region(Region&); + + void populate_page_directory(PageDirectory&); + + void enter_process_paging_scope(Process&); + void enter_kernel_paging_scope(); + + bool validate_user_read(const Process&, LinearAddress) const; + bool validate_user_write(const Process&, LinearAddress) const; + + enum class ShouldZeroFill { No, Yes }; + + RetainPtr<PhysicalPage> allocate_physical_page(ShouldZeroFill); + RetainPtr<PhysicalPage> allocate_supervisor_physical_page(); + + void remap_region(PageDirectory&, Region&); + + size_t ram_size() const { return m_ram_size; } + + int user_physical_pages_in_existence() const { return s_user_physical_pages_in_existence; } + int super_physical_pages_in_existence() const { return s_super_physical_pages_in_existence; } + + void map_for_kernel(LinearAddress, PhysicalAddress); + +private: + MemoryManager(); + ~MemoryManager(); + + void register_vmo(VMObject&); + void unregister_vmo(VMObject&); + void register_region(Region&); + void unregister_region(Region&); + + void map_region_at_address(PageDirectory&, Region&, LinearAddress, bool user_accessible); + void remap_region_page(Region&, unsigned page_index_in_region, bool user_allowed); + + void initialize_paging(); + void flush_entire_tlb(); + void flush_tlb(LinearAddress); + + RetainPtr<PhysicalPage> allocate_page_table(PageDirectory&, unsigned index); + + void map_protected(LinearAddress, size_t length); + + void create_identity_mapping(PageDirectory&, LinearAddress, size_t length); + void remove_identity_mapping(PageDirectory&, LinearAddress, size_t); + + static Region* region_from_laddr(Process&, LinearAddress); + static const Region* region_from_laddr(const Process&, LinearAddress); + + bool copy_on_write(Region&, unsigned page_index_in_region); + bool page_in_from_inode(Region&, unsigned page_index_in_region); + bool zero_page(Region& region, unsigned page_index_in_region); + + 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) { } + + dword* page_table_base() { return reinterpret_cast<dword*>(raw() & 0xfffff000u); } + void set_page_table_base(dword value) + { + *m_pde &= 0xfff; + *m_pde |= value & 0xfffff000; + } + + dword raw() const { return *m_pde; } + dword* ptr() { return m_pde; } + + enum Flags { + Present = 1 << 0, + ReadWrite = 1 << 1, + UserSupervisor = 1 << 2, + WriteThrough = 1 << 3, + CacheDisabled = 1 << 4, + }; + + bool is_present() const { return raw() & Present; } + void set_present(bool b) { set_bit(Present, b); } + + bool is_user_allowed() const { return raw() & UserSupervisor; } + void set_user_allowed(bool b) { set_bit(UserSupervisor, b); } + + bool is_writable() const { return raw() & ReadWrite; } + void set_writable(bool b) { set_bit(ReadWrite, b); } + + bool is_write_through() const { return raw() & WriteThrough; } + void set_write_through(bool b) { set_bit(WriteThrough, b); } + + bool is_cache_disabled() const { return raw() & CacheDisabled; } + void set_cache_disabled(bool b) { set_bit(CacheDisabled, b); } + + void set_bit(byte bit, bool value) + { + if (value) + *m_pde |= bit; + else + *m_pde &= ~bit; + } + + dword* m_pde; + }; + + struct PageTableEntry { + explicit PageTableEntry(dword* pte) : m_pte(pte) { } + + dword* physical_page_base() { return reinterpret_cast<dword*>(raw() & 0xfffff000u); } + void set_physical_page_base(dword value) + { + *m_pte &= 0xfffu; + *m_pte |= value & 0xfffff000u; + } + + dword raw() const { return *m_pte; } + dword* ptr() { return m_pte; } + + enum Flags { + Present = 1 << 0, + ReadWrite = 1 << 1, + UserSupervisor = 1 << 2, + WriteThrough = 1 << 3, + CacheDisabled = 1 << 4, + }; + + bool is_present() const { return raw() & Present; } + void set_present(bool b) { set_bit(Present, b); } + + bool is_user_allowed() const { return raw() & UserSupervisor; } + void set_user_allowed(bool b) { set_bit(UserSupervisor, b); } + + bool is_writable() const { return raw() & ReadWrite; } + void set_writable(bool b) { set_bit(ReadWrite, b); } + + bool is_write_through() const { return raw() & WriteThrough; } + void set_write_through(bool b) { set_bit(WriteThrough, b); } + + bool is_cache_disabled() const { return raw() & CacheDisabled; } + void set_cache_disabled(bool b) { set_bit(CacheDisabled, b); } + + void set_bit(byte bit, bool value) + { + if (value) + *m_pte |= bit; + else + *m_pte &= ~bit; + } + + dword* m_pte; + }; + + static unsigned s_user_physical_pages_in_existence; + static unsigned s_super_physical_pages_in_existence; + + PageTableEntry ensure_pte(PageDirectory&, LinearAddress); + + RetainPtr<PageDirectory> m_kernel_page_directory; + dword* m_page_table_zero; + + LinearAddress m_quickmap_addr; + + Vector<Retained<PhysicalPage>> m_free_physical_pages; + Vector<Retained<PhysicalPage>> m_free_supervisor_physical_pages; + + HashTable<VMObject*> m_vmos; + HashTable<Region*> m_regions; + + size_t m_ram_size { 0 }; + bool m_quickmap_in_use { false }; +}; + +struct ProcessPagingScope { + ProcessPagingScope(Process&); + ~ProcessPagingScope(); +}; + +struct KernelPagingScope { + KernelPagingScope(); + ~KernelPagingScope(); +}; |