90 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			90 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * linux/mm/mmzone.c
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 *
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 * management codes for pgdats and zones.
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 */
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#include <linux/stddef.h>
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#include <linux/mm.h>
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#include <linux/mmzone.h>
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#include <linux/module.h>
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struct pglist_data *first_online_pgdat(void)
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{
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	return NODE_DATA(first_online_node);
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}
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struct pglist_data *next_online_pgdat(struct pglist_data *pgdat)
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{
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	int nid = next_online_node(pgdat->node_id);
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	if (nid == MAX_NUMNODES)
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		return NULL;
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	return NODE_DATA(nid);
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}
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/*
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 * next_zone - helper magic for for_each_zone()
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 */
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struct zone *next_zone(struct zone *zone)
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{
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	pg_data_t *pgdat = zone->zone_pgdat;
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	if (zone < pgdat->node_zones + MAX_NR_ZONES - 1)
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		zone++;
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	else {
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		pgdat = next_online_pgdat(pgdat);
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		if (pgdat)
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			zone = pgdat->node_zones;
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		else
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			zone = NULL;
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	}
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	return zone;
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}
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static inline int zref_in_nodemask(struct zoneref *zref, nodemask_t *nodes)
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{
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#ifdef CONFIG_NUMA
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	return node_isset(zonelist_node_idx(zref), *nodes);
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#else
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	return 1;
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#endif /* CONFIG_NUMA */
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}
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/* Returns the next zone at or below highest_zoneidx in a zonelist */
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struct zoneref *next_zones_zonelist(struct zoneref *z,
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					enum zone_type highest_zoneidx,
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					nodemask_t *nodes,
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					struct zone **zone)
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{
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	/*
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	 * Find the next suitable zone to use for the allocation.
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	 * Only filter based on nodemask if it's set
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	 */
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	if (likely(nodes == NULL))
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		while (zonelist_zone_idx(z) > highest_zoneidx)
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			z++;
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	else
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		while (zonelist_zone_idx(z) > highest_zoneidx ||
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				(z->zone && !zref_in_nodemask(z, nodes)))
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			z++;
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	*zone = zonelist_zone(z);
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	return z;
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}
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#ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL
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int memmap_valid_within(unsigned long pfn,
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					struct page *page, struct zone *zone)
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{
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	if (page_to_pfn(page) != pfn)
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		return 0;
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	if (page_zone(page) != zone)
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		return 0;
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	return 1;
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}
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#endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */
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