Implemented page allocator in C; removed C++.
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30
src/pageallocator.c
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30
src/pageallocator.c
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@@ -0,0 +1,30 @@
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#include "pageallocator.h"
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#include "types/status.h"
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physaddr_t reserve_page(struct page_stack_t *stack)
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{
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if(stack->stack_pointer < stack->base_pointer)
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{
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physaddr_t frame = *stack->stack_pointer;
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*stack->stack_pointer = (physaddr_t) 0;
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stack->stack_pointer++;
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return frame;
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}
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return S_OUT_OF_MEMORY;
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}
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int free_page(struct page_stack_t *stack, physaddr_t location)
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{
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if(stack->stack_pointer > stack->limit_pointer)
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{
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stack->stack_pointer--;
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*stack->stack_pointer = location;
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return S_OK;
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}
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return S_OUT_OF_MEMORY;
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}
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size_t free_page_count(struct page_stack_t *stack)
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{
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return stack->base_pointer - stack->stack_pointer;
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}
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@@ -1,43 +0,0 @@
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#ifndef __MEMORYALLOCATOR_H_
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#define __MEMORYALLOCATOR_H_
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#include <stddef.h>
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#include "systypes.hpp"
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namespace kernelns
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{
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/**
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* Interface for a physical memory allocator.
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*/
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class PageAllocator
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{
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public:
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/**
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* Allocate a single page, returning its physical address. Upon failure,
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* returns an error code such that the least signifigant byte is nonzero.
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*/
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virtual physaddr_t next() = 0;
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/**
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* Frees a single page that has previously been allocated.
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*/
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virtual void free(physaddr_t location) = 0;
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/**
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* @returns the total number of free blocks of memory.
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*/
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virtual size_t freeBlocks() const = 0;
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/**
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* @returns the total number of blocks managed by this memory
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* allocator.
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*/
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virtual size_t getMemorySize() const = 0;
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};
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}
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#endif
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@@ -1,52 +0,0 @@
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#include "pageallocatorstack.hpp"
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#include "memorytype.hpp"
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using namespace kernelns;
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PageAllocatorStack::PageAllocatorStack(physaddr_t *stackBase, physaddr_t *stackTop, size_t frameSize, const MemoryMap& memoryMap)
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{
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m_base = stackBase;
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m_top = stackTop;
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m_stack = m_base;
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for(int i = 0; i < memoryMap.size(); i++)
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{
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if((MemoryType) memoryMap[i].getType() == MemoryType::Available)
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{
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for(int j = 0; j < memoryMap[i].getSize() / frameSize; j++)
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{
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free(memoryMap[i].getLocation() + j * frameSize);
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}
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}
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}
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}
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physaddr_t PageAllocatorStack::next()
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{
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if(m_stack < m_base)
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{
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physaddr_t frame = *m_stack;
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*m_stack = (physaddr_t) 0;
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m_stack++;
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return frame;
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}
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return (physaddr_t) -1;
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}
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void PageAllocatorStack::free(physaddr_t location)
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{
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if(m_stack > m_top)
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{
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m_stack--;
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*m_stack = location;
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}
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}
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size_t PageAllocatorStack::freeBlocks() const
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{
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return m_base - m_stack;
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}
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size_t PageAllocatorStack::getMemorySize() const
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{
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return m_totalSize;
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}
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@@ -1,34 +0,0 @@
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#ifndef PAGEALLOCATORSTACK_H
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#define PAGEALLOCATORSTACK_H
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#include "pageallocator.hpp"
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#include "memorymap.hpp"
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namespace kernelns
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{
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class PageAllocatorStack : public PageAllocator
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{
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public:
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PageAllocatorStack(physaddr_t *stackBase, physaddr_t *stackTop, size_t frameSize, const MemoryMap& memoryMap);
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virtual physaddr_t next();
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virtual void free(physaddr_t location);
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virtual size_t freeBlocks() const;
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virtual size_t getMemorySize() const;
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private:
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size_t m_totalSize;
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physaddr_t *m_stack, *m_base, *m_top;
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};
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}
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#endif
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