/*
 * Written by Pat Gaughen (gone@us.ibm.com) Mar 2002
 *
 */

#ifndef _ASM_MMZONE_H_
#define _ASM_MMZONE_H_

#include <asm/smp.h>

#ifdef CONFIG_DISCONTIGMEM

extern struct pglist_data *node_data[];
#define NODE_DATA(nid)		(node_data[nid])

#define node_localnr(pfn, nid)	((pfn) - NODE_DATA(nid)->node_start_pfn)
#define node_start_pfn(nid)	(NODE_DATA(nid)->node_start_pfn)
#define node_end_pfn(nid)						\
({									\
	pg_data_t *__pgdat = NODE_DATA(nid);				\
	__pgdat->node_start_pfn + __pgdat->node_spanned_pages - 1;	\
})

#define pfn_to_page(pfn)						\
({									\
	unsigned long __pfn = pfn;					\
	int __node  = pfn_to_nid(__pfn);				\
	&NODE_DATA(__node)->node_mem_map[node_localnr(__pfn,__node)];	\
})

#define page_to_pfn(pg)							\
({									\
	struct page *__page = pg;					\
	struct zone *__zone = page_zone(__page);			\
	(unsigned long)(__page - __zone->zone_mem_map)			\
		+ __zone->zone_start_pfn;				\
})
#define pmd_page(pmd)		(pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT))
/*
 * pfn_valid should be made as fast as possible, and the current definition
 * is valid for machines that are NUMA, but still contiguous, which is what
 * is currently supported. A more generalised, but slower definition would
 * be something like this - mbligh:
 * ( pfn_to_pgdat(pfn) && ((pfn) < node_end_pfn(pfn_to_nid(pfn))) )
 */
#if 1	/* M32R_FIXME */
#define pfn_valid(pfn)	(1)
#else
#define pfn_valid(pfn)	((pfn) < num_physpages)
#endif

/*
 * generic node memory support, the following assumptions apply:
 */

static __inline__ int pfn_to_nid(unsigned long pfn)
{
	int node;

	for (node = 0 ; node < MAX_NUMNODES ; node++)
		if (pfn >= node_start_pfn(node) && pfn <= node_end_pfn(node))
			break;

	return node;
}

static __inline__ struct pglist_data *pfn_to_pgdat(unsigned long pfn)
{
	return(NODE_DATA(pfn_to_nid(pfn)));
}

#endif /* CONFIG_DISCONTIGMEM */
#endif /* _ASM_MMZONE_H_ */
