typedef struct
{
  link_t buddy_link;        /**< link to the next free block inside one  order */
  count_t refcount;         /**< tracking of shared frames  */
  u32_t buddy_order;        /**< buddy system block order */
  void *parent;             /**< If allocated by slab, this points there */
} frame_t;

typedef struct {
  SPINLOCK_DECLARE(lock);   /**< this lock protects everything below */
  pfn_t base;               /**< frame_no of the first frame in the frames array */
  count_t count;            /**< Size of zone */

  frame_t *frames;          /**< array of frame_t structures in this zone */
  count_t free_count;       /**< number of free frame_t structures */
  count_t busy_count;       /**< number of busy frame_t structures */

  u32_t max_order;
  link_t order[21];

	int flags;
} zone_t;


typedef struct
{
    link_t  link;
    link_t  adj;
    addr_t  base;
    size_t  size;
    void   *parent;
    u32_t   state;
}md_t;


#define PG_MAP        1
#define PG_WRITE      2
#define PG_USER       4

#define PG_SW         3
#define PG_UW         7



#define PAGE_SIZE    4096
#define FRAME_WIDTH  12

#define BUDDY_SYSTEM_INNER_BLOCK  0xff


# define PA2KA(x) (((addr_t) (x)) + OS_BASE)
# define KA2PA(x) (((addr_t) (x)) - OS_BASE)

static inline count_t SIZE2FRAMES(size_t size)
{
	if (!size)
		return 0;
  return (count_t) ((size - 1) >> FRAME_WIDTH) + 1;
}

static inline addr_t PFN2ADDR(pfn_t frame)
{
  return (addr_t) (frame << FRAME_WIDTH);
}

static inline pfn_t ADDR2PFN(addr_t addr)
{
	return (pfn_t) (addr >> FRAME_WIDTH);
};

void init_mm();

void* __fastcall frame_get_parent(pfn_t pfn);
void  __fastcall frame_set_parent(pfn_t pfn, void *data);

void frame_free(pfn_t frame);


addr_t __fastcall core_alloc(u32_t order);
void   __fastcall core_free(addr_t frame);

pfn_t alloc_page() __attribute__ ((deprecated));


#define __export __attribute__ ((dllexport))


md_t* __fastcall md_alloc(size_t size, u32_t flags) ;
void  __fastcall md_free(md_t *md);

void* __fastcall __export mem_alloc(size_t size, u32_t flags) asm ("MemAlloc");
void  __fastcall __export mem_free(void *mem) asm ("MemFree");