53 lines
1.3 KiB
C
53 lines
1.3 KiB
C
#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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int initialize_page_stack(struct page_stack_t *stack, struct memory_map_t *map, size_t page_size)
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{
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stack->total_pages = 0;
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for(int i = 0; i < map->size; i++)
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{
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if(map->array[i].type != M_AVAILABLE)
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{
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continue;
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}
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size_t location = (map->array[i].location + page_size - 1) & ~(page_size - 1);
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while(location + page_size <= map->array[i].location + map->array[i].size)
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{
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if(free_page(stack, location) != S_OK)
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{
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return S_OUT_OF_MEMORY;
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}
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stack->total_pages++;
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location += page_size;
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}
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}
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}
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