2.6.26-rc1

 mm

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 7469c50..b17dca7 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -29,6 +29,8 @@
 
 #include <asm/tlbflush.h>
 
+#include "internal.h"
+
 /* add this memory to iomem resource */
 static struct resource *register_memory_resource(u64 start, u64 size)
 {
@@ -58,8 +60,105 @@ 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;
@@ -101,6 +200,36 @@ static int __add_section(struct zone *zone, unsigned long phys_start_pfn)
    return register_new_memory(__pfn_to_section(phys_start_pfn));
 }
 
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+static int __remove_section(struct zone *zone, struct mem_section *ms)
+{
+   /*
+    * XXX: Freeing memmap with vmemmap is not implement yet.
+    *      This should be removed later.
+    */
+   return -EBUSY;
+}
+#else
+static int __remove_section(struct zone *zone, struct mem_section *ms)
+{
+   unsigned long flags;
+   struct pglist_data *pgdat = zone->zone_pgdat;
+   int ret = -EINVAL;
+
+   if (!valid_section(ms))
+      return ret;
+
+   ret = unregister_memory_section(ms);
+   if (ret)
+      return ret;
+
+   pgdat_resize_lock(pgdat, &flags);
+   sparse_remove_one_section(zone, ms);
+   pgdat_resize_unlock(pgdat, &flags);
+   return 0;
+}
+#endif
+
 /*
  * Reasonably generic function for adding memory.  It is
  * expected that archs that support memory hotplug will
@@ -134,6 +263,42 @@ int __add_pages(struct zone *zone, unsigned long phys_start_pfn,
 }
 EXPORT_SYMBOL_GPL(__add_pages);
 
+/**
+ * __remove_pages() - remove sections of pages from a zone
+ * @zone: zone from which pages need to be removed
+ * @phys_start_pfn: starting pageframe (must be aligned to start of a section)
+ * @nr_pages: number of pages to remove (must be multiple of section size)
+ *
+ * Generic helper function to remove section mappings and sysfs entries
+ * for the section of the memory we are removing. Caller needs to make
+ * sure that pages are marked reserved and zones are adjust properly by
+ * calling offline_pages().
+ */
+int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
+       unsigned long nr_pages)
+{
+   unsigned long i, ret = 0;
+   int sections_to_remove;
+
+   /*
+    * We can only remove entire sections
+    */
+   BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK);
+   BUG_ON(nr_pages % PAGES_PER_SECTION);
+
+   release_mem_region(phys_start_pfn << PAGE_SHIFT, nr_pages * PAGE_SIZE);
+
+   sections_to_remove = nr_pages / PAGES_PER_SECTION;
+   for (i = 0; i < sections_to_remove; i++) {
+      unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION;
+      ret = __remove_section(zone, __pfn_to_section(pfn));
+      if (ret)
+         break;
+   }
+   return ret;
+}
+EXPORT_SYMBOL_GPL(__remove_pages);
+
 static void grow_zone_span(struct zone *zone,
       unsigned long start_pfn, unsigned long end_pfn)
 {
@@ -164,6 +329,25 @@ static void grow_pgdat_span(struct pglist_data *pgdat,
                pgdat->node_start_pfn;
 }
 
+void online_page(struct page *page)
+{
+   totalram_pages++;
+   num_physpages++;
+
+#ifdef CONFIG_HIGHMEM
+   if (PageHighMem(page))
+      totalhigh_pages++;
+#endif
+
+#ifdef CONFIG_FLATMEM
+   max_mapnr = max(page_to_pfn(page), max_mapnr);
+#endif
+
+   ClearPageReserved(page);
+   init_page_count(page);
+   __free_page(page);
+}
+
 static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
          void *arg)
 {
@@ -208,7 +392,7 @@ int online_pages(unsigned long pfn, unsigned long nr_pages)
    /*
     * This doesn't need a lock to do pfn_to_page().
     * The section can't be removed here because of the
-    * memory_block->state_sem.
+    * memory_block->state_mutex.
     */
    zone = page_zone(pfn_to_page(pfn));
    pgdat_resize_lock(zone->zone_pgdat, &flags);