Kernel: Move PhysicalRange to its own file and add VirtualRange

kernel/include/kernel/Memory/PhysicalRange.h

@@ -0,0 +1,46 @@
+#pragma once
+
+#include <kernel/Memory/Types.h>
+
+#include <stddef.h>
+#include <stdint.h>
+
+namespace Kernel
+{
+
+	class PhysicalRange
+	{
+	public:
+		PhysicalRange(paddr_t, size_t);
+		paddr_t reserve_page();
+		void release_page(paddr_t);
+
+		paddr_t start() const { return m_start; }
+		paddr_t end() const { return m_start + m_size; }
+		bool contains(paddr_t addr) const { return m_start <= addr && addr < m_start + m_size; }
+
+		size_t usable_memory() const { return m_reservable_pages * PAGE_SIZE; }
+
+	private:
+		struct node
+		{
+			node* next;
+			node* prev;
+		};
+		
+		paddr_t page_address(const node*) const;
+		node* node_address(paddr_t) const;
+
+	private:
+		paddr_t m_start	{ 0 };
+		size_t m_size	{ 0 };
+
+		uint64_t m_total_pages		{ 0 };
+		uint64_t m_reservable_pages	{ 0 };
+		uint64_t m_list_pages		{ 0 };
+
+		node* m_free_list { nullptr };
+		node* m_used_list { nullptr };
+	};
+
+}