docs/mm: memblock: add kernel-doc description for memblock types

#define INIT_MEMBLOCK_REGIONS	128

#define INIT_PHYSMEM_REGIONS	4

/* Definition of memblock flags. */

/**

 * enum memblock_flags - definition of memory region attributes

 * @MEMBLOCK_NONE: no special request

 * @MEMBLOCK_HOTPLUG: hotpluggable region

 * @MEMBLOCK_MIRROR: mirrored region

 * @MEMBLOCK_NOMAP: don't add to kernel direct mapping

 */

enum memblock_flags {

	MEMBLOCK_NONE		= 0x0,	/* No special request */

	MEMBLOCK_HOTPLUG	= 0x1,	/* hotpluggable region */

	MEMBLOCK_NOMAP		= 0x4,	/* don't add to kernel direct mapping */

};

/**

 * struct memblock_region - represents a memory region

 * @base: physical address of the region

 * @size: size of the region

 * @flags: memory region attributes

 * @nid: NUMA node id

 */

struct memblock_region {

	phys_addr_t base;

	phys_addr_t size;

#endif

};

/**

 * struct memblock_type - collection of memory regions of certain type

 * @cnt: number of regions

 * @max: size of the allocated array

 * @total_size: size of all regions

 * @regions: array of regions

 * @name: the memory type symbolic name

 */

struct memblock_type {

	unsigned long cnt;	/* number of regions */

	unsigned long max;	/* size of the allocated array */

	phys_addr_t total_size;	/* size of all regions */

	unsigned long cnt;

	unsigned long max;

	phys_addr_t total_size;

	struct memblock_region *regions;

	char *name;

};

/**

 * struct memblock - memblock allocator metadata

 * @bottom_up: is bottom up direction?

 * @current_limit: physical address of the current allocation limit

 * @memory: usabe memory regions

 * @reserved: reserved memory regions

 * @physmem: all physical memory

 */

struct memblock {

	bool bottom_up;  /* is bottom up direction? */

	phys_addr_t current_limit;