5 files changed, 128 insertions, 3 deletions

diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index aca9c65f8d08..73e358612eaf 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -11,6 +11,15 @@ struct pglist_data;
 struct mem_section;
 
 #ifdef CONFIG_MEMORY_HOTPLUG
+
+/*
+ * Magic number for free bootmem.
+ * The normal smallest mapcount is -1. Here is smaller value than it.
+ */
+#define SECTION_INFO            0xfffffffe
+#define MIX_INFO                0xfffffffd
+#define NODE_INFO               0xfffffffc
+
 /*
  * pgdat resizing functions
  */
@@ -145,6 +154,18 @@ static inline void arch_refresh_nodedata(int nid, pg_data_t *pgdat)
 #endif /* CONFIG_NUMA */
 #endif /* CONFIG_HAVE_ARCH_NODEDATA_EXTENSION */
 
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+static inline void register_page_bootmem_info_node(struct pglist_data *pgdat)
+{
+}
+static inline void put_page_bootmem(struct page *page)
+{
+}
+#else
+extern void register_page_bootmem_info_node(struct pglist_data *pgdat);
+extern void put_page_bootmem(struct page *page);
+#endif
+
 #else /* ! CONFIG_MEMORY_HOTPLUG */
 /*
  * Stub functions for when hotplug is off
@@ -172,6 +193,10 @@ static inline int mhp_notimplemented(const char *func)
         return -ENOSYS;
 }
 
+static inline void register_page_bootmem_info_node(struct pglist_data *pgdat)
+{
+}
+
 #endif /* ! CONFIG_MEMORY_HOTPLUG */
 
 extern int add_memory(int nid, u64 start, u64 size);
@@ -180,5 +205,7 @@ extern int remove_memory(u64 start, u64 size);
 extern int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
                                                                 int nr_pages);
 extern void sparse_remove_one_section(struct zone *zone, struct mem_section *ms);
+extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map,
+                                          unsigned long pnum);
 
 #endif /* __LINUX_MEMORY_HOTPLUG_H */
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index c3828497f41d..aad98003176f 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -896,6 +896,7 @@ static inline struct mem_section *__nr_to_section(unsigned long nr)
         return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK];
 }
 extern int __section_nr(struct mem_section* ms);
+extern unsigned long usemap_size(void);
 
 /*
  * We use the lower bits of the mem_map pointer to store
diff --git a/mm/bootmem.c b/mm/bootmem.c
index b6791646143e..369624d2789c 100644
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -461,6 +461,7 @@ void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
 
 unsigned long __init free_all_bootmem_node(pg_data_t *pgdat)
 {
+        register_page_bootmem_info_node(pgdat);
         return free_all_bootmem_core(pgdat);
 }
 
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index c8b3ca79de2d..cba36ef0d506 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -58,8 +58,105 @@ static void release_memory_resource(struct resource *res)
         return;
 }
 
-
 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
+#ifndef CONFIG_SPARSEMEM_VMEMMAP
+static void get_page_bootmem(unsigned long info,  struct page *page, int magic)
+{
+        atomic_set(&page->_mapcount, magic);
+        SetPagePrivate(page);
+        set_page_private(page, info);
+        atomic_inc(&page->_count);
+}
+
+void put_page_bootmem(struct page *page)
+{
+        int magic;
+
+        magic = atomic_read(&page->_mapcount);
+        BUG_ON(magic >= -1);
+
+        if (atomic_dec_return(&page->_count) == 1) {
+                ClearPagePrivate(page);
+                set_page_private(page, 0);
+                reset_page_mapcount(page);
+                __free_pages_bootmem(page, 0);
+        }
+
+}
+
+void register_page_bootmem_info_section(unsigned long start_pfn)
+{
+        unsigned long *usemap, mapsize, section_nr, i;
+        struct mem_section *ms;
+        struct page *page, *memmap;
+
+        if (!pfn_valid(start_pfn))
+                return;
+
+        section_nr = pfn_to_section_nr(start_pfn);
+        ms = __nr_to_section(section_nr);
+
+        /* Get section's memmap address */
+        memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
+
+        /*
+         * Get page for the memmap's phys address
+         * XXX: need more consideration for sparse_vmemmap...
+         */
+        page = virt_to_page(memmap);
+        mapsize = sizeof(struct page) * PAGES_PER_SECTION;
+        mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT;
+
+        /* remember memmap's page */
+        for (i = 0; i < mapsize; i++, page++)
+                get_page_bootmem(section_nr, page, SECTION_INFO);
+
+        usemap = __nr_to_section(section_nr)->pageblock_flags;
+        page = virt_to_page(usemap);
+
+        mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT;
+
+        for (i = 0; i < mapsize; i++, page++)
+                get_page_bootmem(section_nr, page, MIX_INFO);
+
+}
+
+void register_page_bootmem_info_node(struct pglist_data *pgdat)
+{
+        unsigned long i, pfn, end_pfn, nr_pages;
+        int node = pgdat->node_id;
+        struct page *page;
+        struct zone *zone;
+
+        nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT;
+        page = virt_to_page(pgdat);
+
+        for (i = 0; i < nr_pages; i++, page++)
+                get_page_bootmem(node, page, NODE_INFO);
+
+        zone = &pgdat->node_zones[0];
+        for (; zone < pgdat->node_zones + MAX_NR_ZONES - 1; zone++) {
+                if (zone->wait_table) {
+                        nr_pages = zone->wait_table_hash_nr_entries
+                                * sizeof(wait_queue_head_t);
+                        nr_pages = PAGE_ALIGN(nr_pages) >> PAGE_SHIFT;
+                        page = virt_to_page(zone->wait_table);
+
+                        for (i = 0; i < nr_pages; i++, page++)
+                                get_page_bootmem(node, page, NODE_INFO);
+                }
+        }
+
+        pfn = pgdat->node_start_pfn;
+        end_pfn = pfn + pgdat->node_spanned_pages;
+
+        /* register_section info */
+        for (; pfn < end_pfn; pfn += PAGES_PER_SECTION)
+                register_page_bootmem_info_section(pfn);
+
+}
+#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
+
 static int __add_zone(struct zone *zone, unsigned long phys_start_pfn)
 {
         struct pglist_data *pgdat = zone->zone_pgdat;
diff --git a/mm/sparse.c b/mm/sparse.c
index 186a85bf7912..8903c484389a 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -210,7 +210,6 @@ static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long p
 /*
  * Decode mem_map from the coded memmap
  */
-static
 struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum)
 {
         /* mask off the extra low bits of information */
@@ -233,7 +232,7 @@ static int __meminit sparse_init_one_section(struct mem_section *ms,
         return 1;
 }
 
-static unsigned long usemap_size(void)
+unsigned long usemap_size(void)
 {
         unsigned long size_bytes;
         size_bytes = roundup(SECTION_BLOCKFLAGS_BITS, 8) / 8;