Simple physical memory allocator, virtual memory manager

src/buddyallocator.hpp

@@ -0,0 +1,94 @@
+#ifndef BUDDYALLOCATOR_H_
+#define BUDDYALLOCATOR_H_
+
+#include "memoryallocator.hpp"
+#include "memorymap.hpp"
+
+namespace qkernel
+{
+
+class BuddyAllocator : public MemoryAllocator
+{
+public:
+
+	BuddyAllocator();
+
+	BuddyAllocator(MemoryMap& memmap, char* bitmap, size_t blockCount,
+		       size_t treeHeight);
+
+	BuddyAllocator(char* bitmap, size_t blockSize, size_t blockCount,
+		       size_t treeHeight);
+    
+	/**
+	 * Allocate a block of memory containing at least 'size' bytes. 
+	 * Rounds up to the nearest power of 2 times the size of a block.
+	 */
+	virtual physaddr_t allocate(size_t size);
+
+	/**
+	 * Free the region of memory starting at 'location' and containing 
+	 * 'size' bytes.
+	 */
+	virtual void free(physaddr_t location, size_t size);
+
+	/**
+	 * @returns the total number of free blocks of memory.
+	 */
+	virtual size_t freeBlocks() const;
+
+	/**
+	 * @returns the size in blocks of the largest possible allocation that 
+	 * will not fail due to lack of memory.
+	 */
+	virtual size_t maxAllocationSize() const;
+
+	/**
+	 * @returns the size in bytes of a single block.
+	 */
+	virtual size_t getBlockSize() const;
+
+	/**
+	 * @returns the total number of blocks managed by this memory 
+	 * allocator.
+	 */
+	virtual size_t getMemorySize() const;
+
+private:
+
+	static const size_t INVALID = (size_t) -1;
+
+	char* bitmap;
+
+	size_t blockSize;
+
+	size_t blockCount;
+
+	size_t treeHeight;
+
+	size_t findFreeBlock(size_t height);
+
+	size_t split(size_t height, size_t index);
+
+	size_t merge(size_t height, size_t index);
+
+	size_t getBuddy(size_t index);
+
+	size_t getParent(size_t index);
+
+	size_t getChild(size_t index);
+
+	physaddr_t nodeToAddress(size_t height, size_t index) const;
+
+	size_t addressToNode(size_t height, physaddr_t location) const;
+
+	void reserveNode(size_t height, size_t index);
+
+	void freeNode(size_t height, size_t index);
+
+	bool isFree(size_t height, size_t index) const;
+	
+};
+
+}
+
+#endif