+/*
+ * Memory hotplug specific functions
+ */
+void online_page(struct page *page)
+{
+ ClearPageReserved(page);
+ init_page_count(page);
+ __free_page(page);
+ totalram_pages++;
+ num_physpages++;
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+/*
+ * Memory is added always to NORMAL zone. This means you will never get
+ * additional DMA/DMA32 memory.
+ */
+int arch_add_memory(int nid, u64 start, u64 size)
+{
+ struct pglist_data *pgdat = NODE_DATA(nid);
+ struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
+ unsigned long start_pfn = start >> PAGE_SHIFT;
+ unsigned long nr_pages = size >> PAGE_SHIFT;
+ int ret;
+
+ init_memory_mapping(start, (start + size -1));
+
+ ret = __add_pages(zone, start_pfn, nr_pages);
+ if (ret)
+ goto error;
+
+ return ret;
+error:
+ printk("%s: Problem encountered in __add_pages!\n", __func__);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(arch_add_memory);
+
+int remove_memory(u64 start, u64 size)
+{
+ return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(remove_memory);
+
+#if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
+int memory_add_physaddr_to_nid(u64 start)
+{
+ return 0;
+}
+EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
+#endif
+
+#endif /* CONFIG_MEMORY_HOTPLUG */
+
+#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
+/*
+ * Memory Hotadd without sparsemem. The mem_maps have been allocated in advance,
+ * just online the pages.
+ */
+int __add_pages(struct zone *z, unsigned long start_pfn, unsigned long nr_pages)
+{
+ int err = -EIO;
+ unsigned long pfn;
+ unsigned long total = 0, mem = 0;
+ for (pfn = start_pfn; pfn < start_pfn + nr_pages; pfn++) {
+ if (pfn_valid(pfn)) {
+ online_page(pfn_to_page(pfn));
+ err = 0;
+ mem++;
+ }
+ total++;
+ }
+ if (!err) {
+ z->spanned_pages += total;
+ z->present_pages += mem;
+ z->zone_pgdat->node_spanned_pages += total;
+ z->zone_pgdat->node_present_pages += mem;
+ }
+ return err;
+}
+#endif
+
+/*
+ * devmem_is_allowed() checks to see if /dev/mem access to a certain address is
+ * valid. The argument is a physical page number.
+ *
+ *
+ * On x86-64, access has to be given to the first megabyte of ram because that area
+ * contains bios code and data regions used by X and dosemu and similar apps.
+ * Access has to be given to non-kernel-ram areas as well, these contain the PCI
+ * mmio resources as well as potential bios/acpi data regions.
+ */
+int devmem_is_allowed(unsigned long pagenr)
+{
+ if (pagenr <= 256)
+ return 1;
+ if (!page_is_ram(pagenr))
+ return 1;
+ return 0;
+}
+
+
+EXPORT_SYMBOL_GPL(page_is_ram);