/* * linux/mm/memory_hotplug.c * * Copyright (C) */ #include <linux/stddef.h> #include <linux/mm.h> #include <linux/swap.h> #include <linux/interrupt.h> #include <linux/pagemap.h> #include <linux/bootmem.h> #include <linux/compiler.h> #include <linux/module.h> #include <linux/pagevec.h> #include <linux/writeback.h> #include <linux/slab.h> #include <linux/sysctl.h> #include <linux/cpu.h> #include <linux/memory.h> #include <linux/memory_hotplug.h> #include <linux/highmem.h> #include <linux/vmalloc.h> #include <linux/ioport.h> #include <linux/cpuset.h> #include <asm/tlbflush.h> /* add this memory to iomem resource */ static struct resource *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); res = NULL; } return res; } static void release_memory_resource(struct resource *res) { if (!res) return; release_resource(res); kfree(res); return; } #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE 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; int nid = pgdat->node_id; 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, MEMMAP_HOTPLUG); if (ret < 0) return ret; } memmap_init_zone(nr_pages, nid, zone_type, phys_start_pfn, MEMMAP_HOTPLUG); return 0; } static int __add_section(struct zone *zone, unsigned long phys_start_pfn) { int nr_pages = PAGES_PER_SECTION; int ret; if (pfn_valid(phys_start_pfn)) return -EEXIST; ret = sparse_add_one_section(zone, phys_start_pfn, nr_pages); if (ret < 0) return ret; ret = __add_zone(zone, phys_start_pfn); if (ret < 0) return ret; return register_new_memory(__pfn_to_section(phys_start_pfn)); } /* * Reasonably generic function for adding memory. It is * expected that archs that support memory hotplug will * call this function after deciding the zone to which to * add the new pages. */ int __add_pages(struct zone *zone, unsigned long phys_start_pfn, unsigned long nr_pages) { unsigned long i; int err = 0; int start_sec, end_sec; /* during initialize mem_map, align hot-added range to section */ start_sec = pfn_to_section_nr(phys_start_pfn); end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1); for (i = start_sec; i <= end_sec; i++) { err = __add_section(zone, i << PFN_SECTION_SHIFT); /* * EEXIST is finally dealed with by ioresource collision * check. see add_memory() => register_memory_resource() * Warning will be printed if there is collision. */ if (err && (err != -EEXIST)) break; err = 0; } return err; } EXPORT_SYMBOL_GPL(__add_pages); static void grow_zone_span(struct zone *zone, unsigned long start_pfn, unsigned long end_pfn) { unsigned long old_zone_end_pfn; zone_span_writelock(zone); old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages; if (start_pfn < zone->zone_start_pfn) zone->zone_start_pfn = start_pfn; zone->spanned_pages = max(old_zone_end_pfn, end_pfn) - zone->zone_start_pfn; zone_span_writeunlock(zone); } static void grow_pgdat_span(struct pglist_data *pgdat, unsigned long start_pfn, unsigned long end_pfn) { unsigned long old_pgdat_end_pfn = pgdat->node_start_pfn + pgdat->node_spanned_pages; if (start_pfn < pgdat->node_start_pfn) pgdat->node_start_pfn = start_pfn; pgdat->node_spanned_pages = max(old_pgdat_end_pfn, end_pfn) - pgdat->node_start_pfn; } 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(). * The section can't be removed here because of the * memory_block->state_sem. */ zone = page_zone(pfn_to_page(pfn)); pgdat_resize_lock(zone->zone_pgdat, &flags); grow_zone_span(zone, pfn, pfn + nr_pages); grow_pgdat_span(zone->zone_pgdat, pfn, pfn + nr_pages); pgdat_resize_unlock(zone->zone_pgdat, &flags); /* * 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 ((res.start < res.end) && (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(); writeback_set_ratelimit(); return 0; } #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ 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; } int add_memory(int nid, u64 start, u64 size) { pg_data_t *pgdat = NULL; int new_pgdat = 0; struct resource *res; int ret; res = register_memory_resource(start, size); if (!res) return -EEXIST; 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); cpuset_track_online_nodes(); 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); } return ret; error: /* rollback pgdat allocation and others */ if (new_pgdat) rollback_node_hotadd(nid, pgdat); if (res) release_memory_resource(res); return ret; } EXPORT_SYMBOL_GPL(add_memory);