1 /* 2 * This work is licensed under the terms of the GNU LGPL, version 2. 3 * 4 * This is a simple allocator that provides contiguous physical addresses 5 * with byte granularity. 6 */ 7 8 #ifndef ALLOC_PAGE_H 9 #define ALLOC_PAGE_H 1 10 11 #include <asm/memory_areas.h> 12 13 /* Returns true if the page allocator has been initialized */ 14 bool page_alloc_initialized(void); 15 16 /* 17 * Initializes a memory area. 18 * n is the number of the area to initialize 19 * base_pfn is the physical frame number of the start of the area to initialize 20 * top_pfn is the physical frame number of the first page immediately after 21 * the end of the area to initialize 22 */ 23 void page_alloc_init_area(u8 n, uintptr_t base_pfn, uintptr_t top_pfn); 24 25 /* Enables the page allocator. At least one area must have been initialized */ 26 void page_alloc_ops_enable(void); 27 28 /* 29 * Allocate aligned memory from the specified areas. 30 * areas is a bitmap of allowed areas 31 * alignment must be a power of 2 32 */ 33 void *memalign_pages_area(unsigned int areas, size_t alignment, size_t size); 34 35 /* 36 * Allocate aligned memory from any area. 37 * Equivalent to memalign_pages_area(~0, alignment, size). 38 */ 39 void *memalign_pages(size_t alignment, size_t size); 40 41 /* 42 * Allocate naturally aligned memory from the specified areas. 43 * Equivalent to memalign_pages_area(areas, 1ull << order, 1ull << order). 44 */ 45 void *alloc_pages_area(unsigned int areas, unsigned int order); 46 47 /* 48 * Allocate one page from any area. 49 * Equivalent to alloc_pages(0); 50 */ 51 void *alloc_page(void); 52 53 /* 54 * Allocate naturally aligned memory from any area. 55 * Equivalent to alloc_pages_area(~0, order); 56 */ 57 void *alloc_pages(unsigned int order); 58 59 /* 60 * Frees a memory block allocated with any of the memalign_pages* or 61 * alloc_pages* functions. 62 * The pointer must point to the start of the block. 63 */ 64 void free_pages(void *mem, size_t size); 65 66 /* For backwards compatibility */ 67 static inline void free_page(void *mem) 68 { 69 return free_pages(mem, 1); 70 } 71 72 /* For backwards compatibility */ 73 static inline void free_pages_by_order(void *mem, unsigned int order) 74 { 75 free_pages(mem, 1ull << order); 76 } 77 78 #endif 79