1 files changed, 183 insertions, 1 deletions

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 0fb330271271..c4ba85c8cb00 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;
@@ -101,6 +198,36 @@ 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 +261,42 @@ 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 +327,25 @@ 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)
 {