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-rw-r--r--mm/mmzone.c89
1 files changed, 89 insertions, 0 deletions
diff --git a/mm/mmzone.c b/mm/mmzone.c
new file mode 100644
index 00000000..f5b7d176
--- /dev/null
+++ b/mm/mmzone.c
@@ -0,0 +1,89 @@
+/*
+ * linux/mm/mmzone.c
+ *
+ * management codes for pgdats and zones.
+ */
+
+
+#include <linux/stddef.h>
+#include <linux/mm.h>
+#include <linux/mmzone.h>
+#include <linux/module.h>
+
+struct pglist_data *first_online_pgdat(void)
+{
+ return NODE_DATA(first_online_node);
+}
+
+struct pglist_data *next_online_pgdat(struct pglist_data *pgdat)
+{
+ int nid = next_online_node(pgdat->node_id);
+
+ if (nid == MAX_NUMNODES)
+ return NULL;
+ return NODE_DATA(nid);
+}
+
+/*
+ * next_zone - helper magic for for_each_zone()
+ */
+struct zone *next_zone(struct zone *zone)
+{
+ pg_data_t *pgdat = zone->zone_pgdat;
+
+ if (zone < pgdat->node_zones + MAX_NR_ZONES - 1)
+ zone++;
+ else {
+ pgdat = next_online_pgdat(pgdat);
+ if (pgdat)
+ zone = pgdat->node_zones;
+ else
+ zone = NULL;
+ }
+ return zone;
+}
+
+static inline int zref_in_nodemask(struct zoneref *zref, nodemask_t *nodes)
+{
+#ifdef CONFIG_NUMA
+ return node_isset(zonelist_node_idx(zref), *nodes);
+#else
+ return 1;
+#endif /* CONFIG_NUMA */
+}
+
+/* Returns the next zone at or below highest_zoneidx in a zonelist */
+struct zoneref *next_zones_zonelist(struct zoneref *z,
+ enum zone_type highest_zoneidx,
+ nodemask_t *nodes,
+ struct zone **zone)
+{
+ /*
+ * Find the next suitable zone to use for the allocation.
+ * Only filter based on nodemask if it's set
+ */
+ if (likely(nodes == NULL))
+ while (zonelist_zone_idx(z) > highest_zoneidx)
+ z++;
+ else
+ while (zonelist_zone_idx(z) > highest_zoneidx ||
+ (z->zone && !zref_in_nodemask(z, nodes)))
+ z++;
+
+ *zone = zonelist_zone(z);
+ return z;
+}
+
+#ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL
+int memmap_valid_within(unsigned long pfn,
+ struct page *page, struct zone *zone)
+{
+ if (page_to_pfn(page) != pfn)
+ return 0;
+
+ if (page_zone(page) != zone)
+ return 0;
+
+ return 1;
+}
+#endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */