1 files changed, 147 insertions, 7 deletions

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 70df5c0d957..01c9fb97c61 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -4,7 +4,6 @@
  *  Copyright (C)
  */
 
-#include <linux/config.h>
 #include <linux/stddef.h>
 #include <linux/mm.h>
 #include <linux/swap.h>
@@ -21,12 +20,13 @@
 #include <linux/memory_hotplug.h>
 #include <linux/highmem.h>
 #include <linux/vmalloc.h>
+#include <linux/ioport.h>
 
 #include <asm/tlbflush.h>
 
 extern void zonetable_add(struct zone *zone, int nid, int zid, unsigned long pfn,
 			  unsigned long size);
-static void __add_zone(struct zone *zone, unsigned long phys_start_pfn)
+static int __add_zone(struct zone *zone, unsigned long phys_start_pfn)
 {
 	struct pglist_data *pgdat = zone->zone_pgdat;
 	int nr_pages = PAGES_PER_SECTION;
@@ -34,8 +34,15 @@ static void __add_zone(struct zone *zone, unsigned long phys_start_pfn)
 	int zone_type;
 
 	zone_type = zone - pgdat->node_zones;
+	if (!populated_zone(zone)) {
+		int ret = 0;
+		ret = init_currently_empty_zone(zone, phys_start_pfn, nr_pages);
+		if (ret < 0)
+			return ret;
+	}
 	memmap_init_zone(nr_pages, nid, zone_type, phys_start_pfn);
 	zonetable_add(zone, nid, zone_type, phys_start_pfn, nr_pages);
+	return 0;
 }
 
 extern int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
@@ -50,7 +57,11 @@ static int __add_section(struct zone *zone, unsigned long phys_start_pfn)
 	if (ret < 0)
 		return ret;
 
-	__add_zone(zone, phys_start_pfn);
+	ret = __add_zone(zone, phys_start_pfn);
+
+	if (ret < 0)
+		return ret;
+
 	return register_new_memory(__pfn_to_section(phys_start_pfn));
 }
 
@@ -115,7 +126,11 @@ int online_pages(unsigned long pfn, unsigned long nr_pages)
 	unsigned long i;
 	unsigned long flags;
 	unsigned long onlined_pages = 0;
+	struct resource res;
+	u64 section_end;
+	unsigned long start_pfn;
 	struct zone *zone;
+	int need_zonelists_rebuild = 0;
 
 	/*
 	 * This doesn't need a lock to do pfn_to_page().
@@ -128,15 +143,140 @@ int online_pages(unsigned long pfn, unsigned long nr_pages)
 	grow_pgdat_span(zone->zone_pgdat, pfn, pfn + nr_pages);
 	pgdat_resize_unlock(zone->zone_pgdat, &flags);
 
-	for (i = 0; i < nr_pages; i++) {
-		struct page *page = pfn_to_page(pfn + i);
-		online_page(page);
-		onlined_pages++;
+	/*
+	 * If this zone is not populated, then it is not in zonelist.
+	 * This means the page allocator ignores this zone.
+	 * So, zonelist must be updated after online.
+	 */
+	if (!populated_zone(zone))
+		need_zonelists_rebuild = 1;
+
+	res.start = (u64)pfn << PAGE_SHIFT;
+	res.end = res.start + ((u64)nr_pages << PAGE_SHIFT) - 1;
+	res.flags = IORESOURCE_MEM; /* we just need system ram */
+	section_end = res.end;
+
+	while (find_next_system_ram(&res) >= 0) {
+		start_pfn = (unsigned long)(res.start >> PAGE_SHIFT);
+		nr_pages = (unsigned long)
+                           ((res.end + 1 - res.start) >> PAGE_SHIFT);
+
+		if (PageReserved(pfn_to_page(start_pfn))) {
+			/* this region's page is not onlined now */
+			for (i = 0; i < nr_pages; i++) {
+				struct page *page = pfn_to_page(start_pfn + i);
+				online_page(page);
+				onlined_pages++;
+			}
+		}
+
+		res.start = res.end + 1;
+		res.end = section_end;
 	}
 	zone->present_pages += onlined_pages;
 	zone->zone_pgdat->node_present_pages += onlined_pages;
 
 	setup_per_zone_pages_min();
 
+	if (need_zonelists_rebuild)
+		build_all_zonelists();
+	vm_total_pages = nr_free_pagecache_pages();
 	return 0;
 }
+
+static pg_data_t *hotadd_new_pgdat(int nid, u64 start)
+{
+	struct pglist_data *pgdat;
+	unsigned long zones_size[MAX_NR_ZONES] = {0};
+	unsigned long zholes_size[MAX_NR_ZONES] = {0};
+	unsigned long start_pfn = start >> PAGE_SHIFT;
+
+	pgdat = arch_alloc_nodedata(nid);
+	if (!pgdat)
+		return NULL;
+
+	arch_refresh_nodedata(nid, pgdat);
+
+	/* we can use NODE_DATA(nid) from here */
+
+	/* init node's zones as empty zones, we don't have any present pages.*/
+	free_area_init_node(nid, pgdat, zones_size, start_pfn, zholes_size);
+
+	return pgdat;
+}
+
+static void rollback_node_hotadd(int nid, pg_data_t *pgdat)
+{
+	arch_refresh_nodedata(nid, NULL);
+	arch_free_nodedata(pgdat);
+	return;
+}
+
+/* add this memory to iomem resource */
+static void register_memory_resource(u64 start, u64 size)
+{
+	struct resource *res;
+
+	res = kzalloc(sizeof(struct resource), GFP_KERNEL);
+	BUG_ON(!res);
+
+	res->name = "System RAM";
+	res->start = start;
+	res->end = start + size - 1;
+	res->flags = IORESOURCE_MEM;
+	if (request_resource(&iomem_resource, res) < 0) {
+		printk("System RAM resource %llx - %llx cannot be added\n",
+		(unsigned long long)res->start, (unsigned long long)res->end);
+		kfree(res);
+	}
+}
+
+
+
+int add_memory(int nid, u64 start, u64 size)
+{
+	pg_data_t *pgdat = NULL;
+	int new_pgdat = 0;
+	int ret;
+
+	if (!node_online(nid)) {
+		pgdat = hotadd_new_pgdat(nid, start);
+		if (!pgdat)
+			return -ENOMEM;
+		new_pgdat = 1;
+		ret = kswapd_run(nid);
+		if (ret)
+			goto error;
+	}
+
+	/* call arch's memory hotadd */
+	ret = arch_add_memory(nid, start, size);
+
+	if (ret < 0)
+		goto error;
+
+	/* we online node here. we can't roll back from here. */
+	node_set_online(nid);
+
+	if (new_pgdat) {
+		ret = register_one_node(nid);
+		/*
+		 * If sysfs file of new node can't create, cpu on the node
+		 * can't be hot-added. There is no rollback way now.
+		 * So, check by BUG_ON() to catch it reluctantly..
+		 */
+		BUG_ON(ret);
+	}
+
+	/* register this memory as resource */
+	register_memory_resource(start, size);
+
+	return ret;
+error:
+	/* rollback pgdat allocation and others */
+	if (new_pgdat)
+		rollback_node_hotadd(nid, pgdat);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(add_memory);