banan-os/kernel/include/kernel/Memory/PageTable.h

72 lines
1.5 KiB
C++

#pragma once
#include <BAN/Errors.h>
#include <kernel/Memory/Types.h>
#include <kernel/SpinLock.h>
namespace Kernel
{
class PageTable
{
public:
using flags_t = uint8_t;
enum Flags : flags_t
{
Present = 1,
ReadWrite = 2,
UserSupervisor = 4,
};
public:
static void initialize();
static PageTable& kernel();
static PageTable& current();
static BAN::ErrorOr<PageTable*> create_userspace();
~PageTable();
void unmap_page(vaddr_t);
void unmap_range(vaddr_t, size_t bytes);
void map_range_at(paddr_t, vaddr_t, size_t, flags_t);
void map_page_at(paddr_t, vaddr_t, flags_t);
paddr_t physical_address_of(vaddr_t) const;
flags_t get_page_flags(vaddr_t) const;
bool is_page_free(vaddr_t) const;
bool is_range_free(vaddr_t, size_t bytes) const;
vaddr_t get_free_page(vaddr_t first_address = PAGE_SIZE) const;
vaddr_t get_free_contiguous_pages(size_t page_count, vaddr_t first_address = PAGE_SIZE) const;
void load();
void lock() const { m_lock.lock(); }
void unlock() const { m_lock.unlock(); }
void debug_dump();
private:
PageTable() = default;
uint64_t get_page_data(vaddr_t) const;
void initialize_kernel();
void map_kernel_memory();
void invalidate(vaddr_t);
private:
paddr_t m_highest_paging_struct { 0 };
mutable RecursiveSpinLock m_lock;
};
static constexpr size_t range_page_count(vaddr_t start, size_t bytes)
{
size_t first_page = start / PAGE_SIZE;
size_t last_page = BAN::Math::div_round_up<size_t>(start + bytes, PAGE_SIZE);
return last_page - first_page + 1;
}
}