Kernel: Move PhysicalRange to its own file and add VirtualRange

kernel/CMakeLists.txt

@@ -29,6 +29,8 @@ set(KERNEL_SOURCES
 	kernel/Memory/GeneralAllocator.cpp
 	kernel/Memory/Heap.cpp
 	kernel/Memory/kmalloc.cpp
+	kernel/Memory/PhysicalRange.cpp
+	kernel/Memory/VirtualRange.cpp
 	kernel/Panic.cpp
 	kernel/PCI.cpp
 	kernel/PIC.cpp

kernel/include/kernel/Memory/Heap.h

@@ -3,51 +3,12 @@
 #include <BAN/NoCopyMove.h>
 #include <BAN/Vector.h>
 
-#include <stdint.h>
+#include <kernel/Memory/PhysicalRange.h>
-
+#include <kernel/SpinLock.h>
-#define PAGE_SIZE 4096
 
 namespace Kernel
 {
 	
-	using vaddr_t = uintptr_t;
-	using paddr_t = uintptr_t;
-
-	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 };
-	};
-	
 	class Heap
 	{
 		BAN_NON_COPYABLE(Heap);
@@ -65,7 +26,8 @@ namespace Kernel
 		void initialize_impl();
 
 	private:
-		BAN::Vector<PhysicalRange> m_physical_ranges;
+		BAN::Vector<PhysicalRange>	m_physical_ranges;
+		SpinLock					m_lock;
 	};
 
 }

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 };
+	};
+
+}

kernel/include/kernel/Memory/Types.h

@@ -0,0 +1,11 @@
+#pragma once
+
+#define PAGE_SIZE 4096
+
+namespace Kernel
+{
+
+	using vaddr_t = uintptr_t;
+	using paddr_t = uintptr_t;
+	
+}

kernel/include/kernel/Memory/VirtualRange.h

@@ -0,0 +1,38 @@
+#pragma once
+
+#include <BAN/Vector.h>
+#include <BAN/NoCopyMove.h>
+#include <kernel/Memory/MMU.h>
+#include <kernel/Memory/Types.h>
+
+namespace Kernel
+{
+
+	class VirtualRange
+	{
+		BAN_NON_COPYABLE(VirtualRange);
+		BAN_NON_MOVABLE(VirtualRange);
+
+	public:
+		static VirtualRange* create(MMU&, vaddr_t, size_t, uint8_t flags);
+		static VirtualRange* create_kmalloc(size_t);
+		~VirtualRange();
+
+		VirtualRange* clone(MMU& new_mmu);
+
+		vaddr_t vaddr() const { return m_vaddr; }
+		size_t size() const { return m_size; }
+		uint8_t flags() const { return m_flags; }
+
+	private:
+		VirtualRange(MMU&);
+
+	private:
+		MMU&					m_mmu;
+		vaddr_t					m_vaddr { 0 };
+		size_t					m_size { 0 };
+		uint8_t					m_flags { 0 };
+		BAN::Vector<paddr_t>	m_physical_pages;
+	};
+
+}

kernel/kernel/Memory/Heap.cpp

@@ -1,118 +1,11 @@
+#include <kernel/LockGuard.h>
 #include <kernel/Memory/Heap.h>
 #include <kernel/Memory/MMU.h>
 #include <kernel/multiboot.h>
 
-extern uint8_t g_kernel_end[];
-
 namespace Kernel
 {
 
-	PhysicalRange::PhysicalRange(paddr_t start, size_t size)
-	{
-		// We can't use the memory ovelapping with kernel
-		if (start + size <= (paddr_t)g_kernel_end)
-			return;
-
-		// Align start to page boundary and after the kernel memory
-		m_start = BAN::Math::max(start, (paddr_t)g_kernel_end);
-		if (auto rem = m_start % PAGE_SIZE)
-			m_start += PAGE_SIZE - rem;
-
-		if (size <= m_start - start)
-			return;
-
-		// Align size to page boundary
-		m_size = size - (m_start - start);
-		if (auto rem = m_size % PAGE_SIZE)
-			m_size -= rem;
-
-		// We need atleast 2 pages
-		m_total_pages = m_size / PAGE_SIZE;
-		if (m_total_pages <= 1)
-			return;
-
-		// FIXME: if total pages is just over multiple of (PAGE_SIZE / sizeof(node)) we might make
-		//        couple of pages unallocatable
-		m_list_pages		= BAN::Math::div_round_up<uint64_t>(m_total_pages * sizeof(node), PAGE_SIZE);
-		m_reservable_pages	= m_total_pages - m_list_pages;
-
-		MMU::get().identity_map_range(m_start, m_list_pages * PAGE_SIZE, MMU::Flags::ReadWrite | MMU::Flags::Present);
-
-		// Initialize page list so that every page points to the next one
-		node* page_list = (node*)m_start;
-
-		ASSERT((paddr_t)&page_list[m_reservable_pages - 1] <= m_start + m_size);
-
-		for (uint64_t i = 0; i < m_reservable_pages; i++)
-			page_list[i] = { page_list + i - 1, page_list + i + 1 };
-		page_list[           0          ].next = nullptr;
-		page_list[m_reservable_pages - 1].prev = nullptr;
-
-		m_free_list = page_list;
-		m_used_list = nullptr;
-	}
-
-	paddr_t PhysicalRange::reserve_page()
-	{
-		if (m_free_list == nullptr)
-			return 0;
-
-		node* page = m_free_list;
-		ASSERT(page->next == nullptr);
-
-		// Detatch page from top of the free list
-		m_free_list = m_free_list->prev ? m_free_list->prev : nullptr;
-		if (m_free_list)
-			m_free_list->next = nullptr;
-
-		// Add page to used list
-		if (m_used_list)
-			m_used_list->next = page;
-		page->prev = m_used_list;
-		m_used_list = page;
-
-		return page_address(page);
-	}
-
-	void PhysicalRange::release_page(paddr_t page_address)
-	{
-		ASSERT(m_used_list);
-
-		node* page = node_address(page_address);
-		
-		// Detach page from used list
-		if (page->prev)
-			page->prev->next = page->next;
-		if (page->next)
-			page->next->prev = page->prev;
-		if (m_used_list == page)
-			m_used_list = page->prev;
-
-		// Add page to the top of free list
-		page->prev = m_free_list;
-		page->next = nullptr;
-		if (m_free_list)
-			m_free_list->next = page;
-		m_free_list = page;
-	}	
-
-	paddr_t PhysicalRange::page_address(const node* page) const
-	{
-		ASSERT((paddr_t)page <= m_start + m_reservable_pages * sizeof(node));
-		uint64_t page_index = page - (node*)m_start;
-		return m_start + (page_index + m_list_pages) * PAGE_SIZE;
-	}
-
-	PhysicalRange::node* PhysicalRange::node_address(paddr_t page_address) const
-	{
-		ASSERT(page_address % PAGE_SIZE == 0);
-		ASSERT(m_start + m_list_pages * PAGE_SIZE <= page_address && page_address < m_start + m_size);
-		uint64_t page_offset = page_address - (m_start + m_list_pages * PAGE_SIZE);
-		return (node*)m_start + page_offset / PAGE_SIZE;
-	}
-
-
-
 	static Heap* s_instance = nullptr;
 
 	void Heap::initialize()
@@ -160,6 +53,7 @@ namespace Kernel
 
 	paddr_t Heap::take_free_page()
 	{
+		LockGuard _(m_lock);
 		for (auto& range : m_physical_ranges)
 			if (paddr_t page = range.reserve_page())
 				return page;
@@ -168,6 +62,7 @@ namespace Kernel
 	
 	void Heap::release_page(paddr_t addr)
 	{
+		LockGuard _(m_lock);
 		for (auto& range : m_physical_ranges)
 		{
 			if (range.contains(addr))

kernel/kernel/Memory/PhysicalRange.cpp

@@ -0,0 +1,115 @@
+#include <BAN/Assert.h>
+#include <BAN/Math.h>
+#include <kernel/Memory/MMU.h>
+#include <kernel/Memory/PhysicalRange.h>
+
+extern uint8_t g_kernel_end[];
+
+namespace Kernel
+{
+
+	PhysicalRange::PhysicalRange(paddr_t start, size_t size)
+	{
+		// We can't use the memory ovelapping with kernel
+		if (start + size <= (paddr_t)g_kernel_end)
+			return;
+
+		// Align start to page boundary and after the kernel memory
+		m_start = BAN::Math::max(start, (paddr_t)g_kernel_end);
+		if (auto rem = m_start % PAGE_SIZE)
+			m_start += PAGE_SIZE - rem;
+
+		if (size <= m_start - start)
+			return;
+
+		// Align size to page boundary
+		m_size = size - (m_start - start);
+		if (auto rem = m_size % PAGE_SIZE)
+			m_size -= rem;
+
+		// We need atleast 2 pages
+		m_total_pages = m_size / PAGE_SIZE;
+		if (m_total_pages <= 1)
+			return;
+
+		// FIXME: if total pages is just over multiple of (PAGE_SIZE / sizeof(node)) we might make
+		//        couple of pages unallocatable
+		m_list_pages		= BAN::Math::div_round_up<uint64_t>(m_total_pages * sizeof(node), PAGE_SIZE);
+		m_reservable_pages	= m_total_pages - m_list_pages;
+
+		MMU::kernel().identity_map_range(m_start, m_list_pages * PAGE_SIZE, MMU::Flags::ReadWrite | MMU::Flags::Present);
+
+		// Initialize page list so that every page points to the next one
+		node* page_list = (node*)m_start;
+
+		ASSERT((paddr_t)&page_list[m_reservable_pages - 1] <= m_start + m_size);
+
+		for (uint64_t i = 0; i < m_reservable_pages; i++)
+			page_list[i] = { page_list + i - 1, page_list + i + 1 };
+		page_list[           0          ].next = nullptr;
+		page_list[m_reservable_pages - 1].prev = nullptr;
+
+		m_free_list = page_list;
+		m_used_list = nullptr;
+	}
+
+	paddr_t PhysicalRange::reserve_page()
+	{
+		if (m_free_list == nullptr)
+			return 0;
+
+		node* page = m_free_list;
+		ASSERT(page->next == nullptr);
+
+		// Detatch page from top of the free list
+		m_free_list = m_free_list->prev ? m_free_list->prev : nullptr;
+		if (m_free_list)
+			m_free_list->next = nullptr;
+
+		// Add page to used list
+		if (m_used_list)
+			m_used_list->next = page;
+		page->prev = m_used_list;
+		m_used_list = page;
+
+		return page_address(page);
+	}
+
+	void PhysicalRange::release_page(paddr_t page_address)
+	{
+		ASSERT(m_used_list);
+
+		node* page = node_address(page_address);
+		
+		// Detach page from used list
+		if (page->prev)
+			page->prev->next = page->next;
+		if (page->next)
+			page->next->prev = page->prev;
+		if (m_used_list == page)
+			m_used_list = page->prev;
+
+		// Add page to the top of free list
+		page->prev = m_free_list;
+		page->next = nullptr;
+		if (m_free_list)
+			m_free_list->next = page;
+		m_free_list = page;
+	}	
+
+	paddr_t PhysicalRange::page_address(const node* page) const
+	{
+		ASSERT((paddr_t)page <= m_start + m_reservable_pages * sizeof(node));
+		uint64_t page_index = page - (node*)m_start;
+		return m_start + (page_index + m_list_pages) * PAGE_SIZE;
+	}
+
+	PhysicalRange::node* PhysicalRange::node_address(paddr_t page_address) const
+	{
+		ASSERT(page_address % PAGE_SIZE == 0);
+		ASSERT(m_start + m_list_pages * PAGE_SIZE <= page_address && page_address < m_start + m_size);
+		uint64_t page_offset = page_address - (m_start + m_list_pages * PAGE_SIZE);
+		return (node*)m_start + page_offset / PAGE_SIZE;
+	}	
+
+}

kernel/kernel/Memory/VirtualRange.cpp

@@ -0,0 +1,93 @@
+#include <kernel/Memory/Heap.h>
+#include <kernel/Memory/MMUScope.h>
+#include <kernel/Memory/VirtualRange.h>
+
+namespace Kernel
+{
+
+	VirtualRange* VirtualRange::create(MMU& mmu, vaddr_t vaddr, size_t size, uint8_t flags)
+	{
+		ASSERT(size % PAGE_SIZE == 0);
+		ASSERT(vaddr % PAGE_SIZE == 0);
+		ASSERT(&mmu != &MMU::kernel());
+
+		VirtualRange* result = new VirtualRange(mmu);
+		ASSERT(result);
+
+		result->m_size = size;
+		result->m_flags = flags;
+		MUST(result->m_physical_pages.reserve(size / PAGE_SIZE));
+
+		mmu.lock();
+
+		if (vaddr == 0)
+		{
+			vaddr = mmu.get_free_contiguous_pages(size / PAGE_SIZE);
+			ASSERT(vaddr);
+		}
+
+		result->m_vaddr = vaddr;
+
+		ASSERT(mmu.is_range_free(vaddr, size));
+		for (size_t offset = 0; offset < size; offset += PAGE_SIZE)
+		{
+			paddr_t paddr = Heap::get().take_free_page();
+			ASSERT(paddr);
+			MUST(result->m_physical_pages.push_back(paddr));
+			mmu.map_page_at(paddr, vaddr + offset, flags);
+		}
+		mmu.unlock();
+
+		return result;
+	}
+
+	VirtualRange* VirtualRange::create_kmalloc(size_t size)
+	{
+		VirtualRange* result = new VirtualRange(MMU::kernel());
+		if (result == nullptr)
+			return nullptr;
+		result->m_size = size;
+		result->m_flags = MMU::Flags::ReadWrite | MMU::Flags::Present;
+		result->m_vaddr = (vaddr_t)kmalloc(size);
+		if (result->m_vaddr == 0)
+		{
+			delete result;
+			return nullptr;
+		}
+		return result;
+	}
+
+	VirtualRange::VirtualRange(MMU& mmu)
+		: m_mmu(mmu)
+	{ }
+
+	VirtualRange::~VirtualRange()
+	{
+		if (&m_mmu == &MMU::kernel())
+		{
+			kfree((void*)m_vaddr);
+			return;
+		}
+
+		m_mmu.unmap_range(vaddr(), size());
+		for (paddr_t page : m_physical_pages)
+			Heap::get().release_page(page);
+	}
+
+	VirtualRange* VirtualRange::clone(MMU& mmu)
+	{
+		VirtualRange* result = create(mmu, vaddr(), size(), flags());
+
+		MMUScope _(m_mmu);
+		ASSERT(m_mmu.is_page_free(0));
+		for (size_t i = 0; i < result->m_physical_pages.size(); i++)
+		{
+			m_mmu.map_page_at(result->m_physical_pages[i], 0, MMU::Flags::ReadWrite | MMU::Flags::Present);
+			memcpy((void*)0, (void*)(vaddr() + i * PAGE_SIZE), PAGE_SIZE);
+		}
+		m_mmu.unmap_page(0);
+
+		return result;
+	}
+
+}