diff options
Diffstat (limited to 'mm/memory_hotplug.c')
| -rw-r--r-- | mm/memory_hotplug.c | 1944 |
1 files changed, 1944 insertions, 0 deletions
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c new file mode 100644 index 000000000..20f079c81 --- /dev/null +++ b/mm/memory_hotplug.c @@ -0,0 +1,1944 @@ +/* + * linux/mm/memory_hotplug.c + * + * Copyright (C) + */ + +#include <linux/stddef.h> +#include <linux/mm.h> +#include <linux/sched/signal.h> +#include <linux/swap.h> +#include <linux/interrupt.h> +#include <linux/pagemap.h> +#include <linux/compiler.h> +#include <linux/export.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/memremap.h> +#include <linux/memory_hotplug.h> +#include <linux/highmem.h> +#include <linux/vmalloc.h> +#include <linux/ioport.h> +#include <linux/delay.h> +#include <linux/migrate.h> +#include <linux/page-isolation.h> +#include <linux/pfn.h> +#include <linux/suspend.h> +#include <linux/mm_inline.h> +#include <linux/firmware-map.h> +#include <linux/stop_machine.h> +#include <linux/hugetlb.h> +#include <linux/memblock.h> +#include <linux/bootmem.h> +#include <linux/compaction.h> +#include <linux/rmap.h> + +#include <asm/tlbflush.h> + +#include "internal.h" + +/* + * online_page_callback contains pointer to current page onlining function. + * Initially it is generic_online_page(). If it is required it could be + * changed by calling set_online_page_callback() for callback registration + * and restore_online_page_callback() for generic callback restore. + */ + +static void generic_online_page(struct page *page); + +static online_page_callback_t online_page_callback = generic_online_page; +static DEFINE_MUTEX(online_page_callback_lock); + +DEFINE_STATIC_PERCPU_RWSEM(mem_hotplug_lock); + +void get_online_mems(void) +{ + percpu_down_read(&mem_hotplug_lock); +} + +void put_online_mems(void) +{ + percpu_up_read(&mem_hotplug_lock); +} + +bool movable_node_enabled = false; + +#ifndef CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE +bool memhp_auto_online; +#else +bool memhp_auto_online = true; +#endif +EXPORT_SYMBOL_GPL(memhp_auto_online); + +static int __init setup_memhp_default_state(char *str) +{ + if (!strcmp(str, "online")) + memhp_auto_online = true; + else if (!strcmp(str, "offline")) + memhp_auto_online = false; + + return 1; +} +__setup("memhp_default_state=", setup_memhp_default_state); + +void mem_hotplug_begin(void) +{ + cpus_read_lock(); + percpu_down_write(&mem_hotplug_lock); +} + +void mem_hotplug_done(void) +{ + percpu_up_write(&mem_hotplug_lock); + cpus_read_unlock(); +} + +/* add this memory to iomem resource */ +static struct resource *register_memory_resource(u64 start, u64 size) +{ + struct resource *res, *conflict; + res = kzalloc(sizeof(struct resource), GFP_KERNEL); + if (!res) + return ERR_PTR(-ENOMEM); + + res->name = "System RAM"; + res->start = start; + res->end = start + size - 1; + res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; + conflict = request_resource_conflict(&iomem_resource, res); + if (conflict) { + if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) { + pr_debug("Device unaddressable memory block " + "memory hotplug at %#010llx !\n", + (unsigned long long)start); + } + pr_debug("System RAM resource %pR cannot be added\n", res); + kfree(res); + return ERR_PTR(-EEXIST); + } + return res; +} + +static void release_memory_resource(struct resource *res) +{ + if (!res) + return; + release_resource(res); + kfree(res); + return; +} + +#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE +void get_page_bootmem(unsigned long info, struct page *page, + unsigned long type) +{ + page->freelist = (void *)type; + SetPagePrivate(page); + set_page_private(page, info); + page_ref_inc(page); +} + +void put_page_bootmem(struct page *page) +{ + unsigned long type; + + type = (unsigned long) page->freelist; + BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE || + type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE); + + if (page_ref_dec_return(page) == 1) { + page->freelist = NULL; + ClearPagePrivate(page); + set_page_private(page, 0); + INIT_LIST_HEAD(&page->lru); + free_reserved_page(page); + } +} + +#ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE +#ifndef CONFIG_SPARSEMEM_VMEMMAP +static 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; + + 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 = ms->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_SECTION_INFO); + +} +#else /* CONFIG_SPARSEMEM_VMEMMAP */ +static 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; + + section_nr = pfn_to_section_nr(start_pfn); + ms = __nr_to_section(section_nr); + + memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); + + register_page_bootmem_memmap(section_nr, memmap, PAGES_PER_SECTION); + + usemap = ms->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_SECTION_INFO); +} +#endif /* !CONFIG_SPARSEMEM_VMEMMAP */ + +void __init 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; + + 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); + + pfn = pgdat->node_start_pfn; + end_pfn = pgdat_end_pfn(pgdat); + + /* register section info */ + for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) { + /* + * Some platforms can assign the same pfn to multiple nodes - on + * node0 as well as nodeN. To avoid registering a pfn against + * multiple nodes we check that this pfn does not already + * reside in some other nodes. + */ + if (pfn_valid(pfn) && (early_pfn_to_nid(pfn) == node)) + register_page_bootmem_info_section(pfn); + } +} +#endif /* CONFIG_HAVE_BOOTMEM_INFO_NODE */ + +static int __meminit __add_section(int nid, unsigned long phys_start_pfn, + struct vmem_altmap *altmap, bool want_memblock) +{ + int ret; + + if (pfn_valid(phys_start_pfn)) + return -EEXIST; + + ret = sparse_add_one_section(nid, phys_start_pfn, altmap); + return ret < 0 ? ret : 0; +} + +/* + * 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 __ref __add_pages(int nid, unsigned long phys_start_pfn, + unsigned long nr_pages, struct vmem_altmap *altmap, + bool want_memblock) +{ + 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); + + if (altmap) { + /* + * Validate altmap is within bounds of the total request + */ + if (altmap->base_pfn != phys_start_pfn + || vmem_altmap_offset(altmap) > nr_pages) { + pr_warn_once("memory add fail, invalid altmap\n"); + err = -EINVAL; + goto out; + } + altmap->alloc = 0; + } + + for (i = start_sec; i <= end_sec; i++) { + err = __add_section(nid, section_nr_to_pfn(i), altmap, + want_memblock); + + /* + * EEXIST is finally dealt 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; + cond_resched(); + } + vmemmap_populate_print_last(); +out: + return err; +} + +/* find the smallest valid pfn in the range [start_pfn, end_pfn) */ +static unsigned long find_smallest_section_pfn(int nid, struct zone *zone, + unsigned long start_pfn, + unsigned long end_pfn) +{ + for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SECTION) { + if (unlikely(!pfn_to_online_page(start_pfn))) + continue; + + if (unlikely(pfn_to_nid(start_pfn) != nid)) + continue; + + if (zone && zone != page_zone(pfn_to_page(start_pfn))) + continue; + + return start_pfn; + } + + return 0; +} + +/* find the biggest valid pfn in the range [start_pfn, end_pfn). */ +static unsigned long find_biggest_section_pfn(int nid, struct zone *zone, + unsigned long start_pfn, + unsigned long end_pfn) +{ + unsigned long pfn; + + /* pfn is the end pfn of a memory section. */ + pfn = end_pfn - 1; + for (; pfn >= start_pfn; pfn -= PAGES_PER_SECTION) { + if (unlikely(!pfn_to_online_page(pfn))) + continue; + + if (unlikely(pfn_to_nid(pfn) != nid)) + continue; + + if (zone && zone != page_zone(pfn_to_page(pfn))) + continue; + + return pfn; + } + + return 0; +} + +static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, + unsigned long end_pfn) +{ + unsigned long zone_start_pfn = zone->zone_start_pfn; + unsigned long z = zone_end_pfn(zone); /* zone_end_pfn namespace clash */ + unsigned long zone_end_pfn = z; + unsigned long pfn; + int nid = zone_to_nid(zone); + + zone_span_writelock(zone); + if (zone_start_pfn == start_pfn) { + /* + * If the section is smallest section in the zone, it need + * shrink zone->zone_start_pfn and zone->zone_spanned_pages. + * In this case, we find second smallest valid mem_section + * for shrinking zone. + */ + pfn = find_smallest_section_pfn(nid, zone, end_pfn, + zone_end_pfn); + if (pfn) { + zone->zone_start_pfn = pfn; + zone->spanned_pages = zone_end_pfn - pfn; + } + } else if (zone_end_pfn == end_pfn) { + /* + * If the section is biggest section in the zone, it need + * shrink zone->spanned_pages. + * In this case, we find second biggest valid mem_section for + * shrinking zone. + */ + pfn = find_biggest_section_pfn(nid, zone, zone_start_pfn, + start_pfn); + if (pfn) + zone->spanned_pages = pfn - zone_start_pfn + 1; + } + + /* + * The section is not biggest or smallest mem_section in the zone, it + * only creates a hole in the zone. So in this case, we need not + * change the zone. But perhaps, the zone has only hole data. Thus + * it check the zone has only hole or not. + */ + pfn = zone_start_pfn; + for (; pfn < zone_end_pfn; pfn += PAGES_PER_SECTION) { + if (unlikely(!pfn_to_online_page(pfn))) + continue; + + if (page_zone(pfn_to_page(pfn)) != zone) + continue; + + /* If the section is current section, it continues the loop */ + if (start_pfn == pfn) + continue; + + /* If we find valid section, we have nothing to do */ + zone_span_writeunlock(zone); + return; + } + + /* The zone has no valid section */ + zone->zone_start_pfn = 0; + zone->spanned_pages = 0; + zone_span_writeunlock(zone); +} + +static void update_pgdat_span(struct pglist_data *pgdat) +{ + unsigned long node_start_pfn = 0, node_end_pfn = 0; + struct zone *zone; + + for (zone = pgdat->node_zones; + zone < pgdat->node_zones + MAX_NR_ZONES; zone++) { + unsigned long zone_end_pfn = zone->zone_start_pfn + + zone->spanned_pages; + + /* No need to lock the zones, they can't change. */ + if (!zone->spanned_pages) + continue; + if (!node_end_pfn) { + node_start_pfn = zone->zone_start_pfn; + node_end_pfn = zone_end_pfn; + continue; + } + + if (zone_end_pfn > node_end_pfn) + node_end_pfn = zone_end_pfn; + if (zone->zone_start_pfn < node_start_pfn) + node_start_pfn = zone->zone_start_pfn; + } + + pgdat->node_start_pfn = node_start_pfn; + pgdat->node_spanned_pages = node_end_pfn - node_start_pfn; +} + +void __ref remove_pfn_range_from_zone(struct zone *zone, + unsigned long start_pfn, + unsigned long nr_pages) +{ + struct pglist_data *pgdat = zone->zone_pgdat; + unsigned long flags; + +#ifdef CONFIG_ZONE_DEVICE + /* + * Zone shrinking code cannot properly deal with ZONE_DEVICE. So + * we will not try to shrink the zones - which is okay as + * set_zone_contiguous() cannot deal with ZONE_DEVICE either way. + */ + if (zone_idx(zone) == ZONE_DEVICE) + return; +#endif + + clear_zone_contiguous(zone); + + pgdat_resize_lock(zone->zone_pgdat, &flags); + shrink_zone_span(zone, start_pfn, start_pfn + nr_pages); + update_pgdat_span(pgdat); + pgdat_resize_unlock(zone->zone_pgdat, &flags); + + set_zone_contiguous(zone); +} + +static void __remove_section(struct mem_section *ms, unsigned long map_offset, + struct vmem_altmap *altmap) +{ + unsigned long start_pfn; + int scn_nr; + + if (WARN_ON_ONCE(!valid_section(ms))) + return; + + scn_nr = __section_nr(ms); + start_pfn = section_nr_to_pfn((unsigned long)scn_nr); + + sparse_remove_one_section(ms, map_offset, altmap); +} + +/** + * __remove_pages() - remove sections of pages + * @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) + * @altmap: alternative device page map or %NULL if default memmap is used + * + * 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(). + */ +void __remove_pages(unsigned long phys_start_pfn, unsigned long nr_pages, + struct vmem_altmap *altmap) +{ + unsigned long i; + unsigned long map_offset = 0; + int sections_to_remove; + + if (altmap) + map_offset = vmem_altmap_offset(altmap); + + /* + * We can only remove entire sections + */ + BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK); + BUG_ON(nr_pages % PAGES_PER_SECTION); + + 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; + + cond_resched(); + __remove_section(__pfn_to_section(pfn), map_offset, altmap); + map_offset = 0; + } +} + +int set_online_page_callback(online_page_callback_t callback) +{ + int rc = -EINVAL; + + get_online_mems(); + mutex_lock(&online_page_callback_lock); + + if (online_page_callback == generic_online_page) { + online_page_callback = callback; + rc = 0; + } + + mutex_unlock(&online_page_callback_lock); + put_online_mems(); + + return rc; +} +EXPORT_SYMBOL_GPL(set_online_page_callback); + +int restore_online_page_callback(online_page_callback_t callback) +{ + int rc = -EINVAL; + + get_online_mems(); + mutex_lock(&online_page_callback_lock); + + if (online_page_callback == callback) { + online_page_callback = generic_online_page; + rc = 0; + } + + mutex_unlock(&online_page_callback_lock); + put_online_mems(); + + return rc; +} +EXPORT_SYMBOL_GPL(restore_online_page_callback); + +void __online_page_set_limits(struct page *page) +{ +} +EXPORT_SYMBOL_GPL(__online_page_set_limits); + +void __online_page_increment_counters(struct page *page) +{ + adjust_managed_page_count(page, 1); +} +EXPORT_SYMBOL_GPL(__online_page_increment_counters); + +void __online_page_free(struct page *page) +{ + __free_reserved_page(page); +} +EXPORT_SYMBOL_GPL(__online_page_free); + +static void generic_online_page(struct page *page) +{ + __online_page_set_limits(page); + __online_page_increment_counters(page); + __online_page_free(page); +} + +static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages, + void *arg) +{ + unsigned long i; + unsigned long onlined_pages = *(unsigned long *)arg; + struct page *page; + + if (PageReserved(pfn_to_page(start_pfn))) + for (i = 0; i < nr_pages; i++) { + page = pfn_to_page(start_pfn + i); + (*online_page_callback)(page); + onlined_pages++; + } + + online_mem_sections(start_pfn, start_pfn + nr_pages); + + *(unsigned long *)arg = onlined_pages; + return 0; +} + +/* check which state of node_states will be changed when online memory */ +static void node_states_check_changes_online(unsigned long nr_pages, + struct zone *zone, struct memory_notify *arg) +{ + int nid = zone_to_nid(zone); + enum zone_type zone_last = ZONE_NORMAL; + + /* + * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY] + * contains nodes which have zones of 0...ZONE_NORMAL, + * set zone_last to ZONE_NORMAL. + * + * If we don't have HIGHMEM nor movable node, + * node_states[N_NORMAL_MEMORY] contains nodes which have zones of + * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE. + */ + if (N_MEMORY == N_NORMAL_MEMORY) + zone_last = ZONE_MOVABLE; + + /* + * if the memory to be online is in a zone of 0...zone_last, and + * the zones of 0...zone_last don't have memory before online, we will + * need to set the node to node_states[N_NORMAL_MEMORY] after + * the memory is online. + */ + if (zone_idx(zone) <= zone_last && !node_state(nid, N_NORMAL_MEMORY)) + arg->status_change_nid_normal = nid; + else + arg->status_change_nid_normal = -1; + +#ifdef CONFIG_HIGHMEM + /* + * If we have movable node, node_states[N_HIGH_MEMORY] + * contains nodes which have zones of 0...ZONE_HIGHMEM, + * set zone_last to ZONE_HIGHMEM. + * + * If we don't have movable node, node_states[N_NORMAL_MEMORY] + * contains nodes which have zones of 0...ZONE_MOVABLE, + * set zone_last to ZONE_MOVABLE. + */ + zone_last = ZONE_HIGHMEM; + if (N_MEMORY == N_HIGH_MEMORY) + zone_last = ZONE_MOVABLE; + + if (zone_idx(zone) <= zone_last && !node_state(nid, N_HIGH_MEMORY)) + arg->status_change_nid_high = nid; + else + arg->status_change_nid_high = -1; +#else + arg->status_change_nid_high = arg->status_change_nid_normal; +#endif + + /* + * if the node don't have memory befor online, we will need to + * set the node to node_states[N_MEMORY] after the memory + * is online. + */ + if (!node_state(nid, N_MEMORY)) + arg->status_change_nid = nid; + else + arg->status_change_nid = -1; +} + +static void node_states_set_node(int node, struct memory_notify *arg) +{ + if (arg->status_change_nid_normal >= 0) + node_set_state(node, N_NORMAL_MEMORY); + + if (arg->status_change_nid_high >= 0) + node_set_state(node, N_HIGH_MEMORY); + + node_set_state(node, N_MEMORY); +} + +static void __meminit resize_zone_range(struct zone *zone, unsigned long start_pfn, + unsigned long nr_pages) +{ + unsigned long old_end_pfn = zone_end_pfn(zone); + + if (zone_is_empty(zone) || start_pfn < zone->zone_start_pfn) + zone->zone_start_pfn = start_pfn; + + zone->spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - zone->zone_start_pfn; +} + +static void __meminit resize_pgdat_range(struct pglist_data *pgdat, unsigned long start_pfn, + unsigned long nr_pages) +{ + unsigned long old_end_pfn = pgdat_end_pfn(pgdat); + + if (!pgdat->node_spanned_pages || start_pfn < pgdat->node_start_pfn) + pgdat->node_start_pfn = start_pfn; + + pgdat->node_spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - pgdat->node_start_pfn; +} + +void __ref move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn, + unsigned long nr_pages, struct vmem_altmap *altmap) +{ + struct pglist_data *pgdat = zone->zone_pgdat; + int nid = pgdat->node_id; + unsigned long flags; + + if (zone_is_empty(zone)) + init_currently_empty_zone(zone, start_pfn, nr_pages); + + clear_zone_contiguous(zone); + + /* TODO Huh pgdat is irqsave while zone is not. It used to be like that before */ + pgdat_resize_lock(pgdat, &flags); + zone_span_writelock(zone); + resize_zone_range(zone, start_pfn, nr_pages); + zone_span_writeunlock(zone); + resize_pgdat_range(pgdat, start_pfn, nr_pages); + pgdat_resize_unlock(pgdat, &flags); + + /* + * TODO now we have a visible range of pages which are not associated + * with their zone properly. Not nice but set_pfnblock_flags_mask + * expects the zone spans the pfn range. All the pages in the range + * are reserved so nobody should be touching them so we should be safe + */ + memmap_init_zone(nr_pages, nid, zone_idx(zone), start_pfn, + MEMINIT_HOTPLUG, altmap); + + set_zone_contiguous(zone); +} + +/* + * Returns a default kernel memory zone for the given pfn range. + * If no kernel zone covers this pfn range it will automatically go + * to the ZONE_NORMAL. + */ +static struct zone *default_kernel_zone_for_pfn(int nid, unsigned long start_pfn, + unsigned long nr_pages) +{ + struct pglist_data *pgdat = NODE_DATA(nid); + int zid; + + for (zid = 0; zid <= ZONE_NORMAL; zid++) { + struct zone *zone = &pgdat->node_zones[zid]; + + if (zone_intersects(zone, start_pfn, nr_pages)) + return zone; + } + + return &pgdat->node_zones[ZONE_NORMAL]; +} + +static inline struct zone *default_zone_for_pfn(int nid, unsigned long start_pfn, + unsigned long nr_pages) +{ + struct zone *kernel_zone = default_kernel_zone_for_pfn(nid, start_pfn, + nr_pages); + struct zone *movable_zone = &NODE_DATA(nid)->node_zones[ZONE_MOVABLE]; + bool in_kernel = zone_intersects(kernel_zone, start_pfn, nr_pages); + bool in_movable = zone_intersects(movable_zone, start_pfn, nr_pages); + + /* + * We inherit the existing zone in a simple case where zones do not + * overlap in the given range + */ + if (in_kernel ^ in_movable) + return (in_kernel) ? kernel_zone : movable_zone; + + /* + * If the range doesn't belong to any zone or two zones overlap in the + * given range then we use movable zone only if movable_node is + * enabled because we always online to a kernel zone by default. + */ + return movable_node_enabled ? movable_zone : kernel_zone; +} + +struct zone *zone_for_pfn_range(int online_type, int nid, + unsigned long start_pfn, unsigned long nr_pages) +{ + if (online_type == MMOP_ONLINE_KERNEL) + return default_kernel_zone_for_pfn(nid, start_pfn, nr_pages); + + if (online_type == MMOP_ONLINE_MOVABLE) + return &NODE_DATA(nid)->node_zones[ZONE_MOVABLE]; + + return default_zone_for_pfn(nid, start_pfn, nr_pages); +} + +/* + * Associates the given pfn range with the given node and the zone appropriate + * for the given online type. + */ +static struct zone * __meminit move_pfn_range(int online_type, int nid, + unsigned long start_pfn, unsigned long nr_pages) +{ + struct zone *zone; + + zone = zone_for_pfn_range(online_type, nid, start_pfn, nr_pages); + move_pfn_range_to_zone(zone, start_pfn, nr_pages, NULL); + return zone; +} + +int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_type) +{ + unsigned long flags; + unsigned long onlined_pages = 0; + struct zone *zone; + int need_zonelists_rebuild = 0; + int nid; + int ret; + struct memory_notify arg; + struct memory_block *mem; + + mem_hotplug_begin(); + + /* + * We can't use pfn_to_nid() because nid might be stored in struct page + * which is not yet initialized. Instead, we find nid from memory block. + */ + mem = find_memory_block(__pfn_to_section(pfn)); + nid = mem->nid; + put_device(&mem->dev); + + /* associate pfn range with the zone */ + zone = move_pfn_range(online_type, nid, pfn, nr_pages); + + arg.start_pfn = pfn; + arg.nr_pages = nr_pages; + node_states_check_changes_online(nr_pages, zone, &arg); + + ret = memory_notify(MEM_GOING_ONLINE, &arg); + ret = notifier_to_errno(ret); + if (ret) + goto failed_addition; + + /* + * 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; + setup_zone_pageset(zone); + } + + ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages, + online_pages_range); + if (ret) { + if (need_zonelists_rebuild) + zone_pcp_reset(zone); + goto failed_addition; + } + + zone->present_pages += onlined_pages; + + pgdat_resize_lock(zone->zone_pgdat, &flags); + zone->zone_pgdat->node_present_pages += onlined_pages; + pgdat_resize_unlock(zone->zone_pgdat, &flags); + + if (onlined_pages) { + node_states_set_node(nid, &arg); + if (need_zonelists_rebuild) + build_all_zonelists(NULL); + else + zone_pcp_update(zone); + } + + init_per_zone_wmark_min(); + + if (onlined_pages) { + kswapd_run(nid); + kcompactd_run(nid); + } + + vm_total_pages = nr_free_pagecache_pages(); + + writeback_set_ratelimit(); + + if (onlined_pages) + memory_notify(MEM_ONLINE, &arg); + mem_hotplug_done(); + return 0; + +failed_addition: + pr_debug("online_pages [mem %#010llx-%#010llx] failed\n", + (unsigned long long) pfn << PAGE_SHIFT, + (((unsigned long long) pfn + nr_pages) << PAGE_SHIFT) - 1); + memory_notify(MEM_CANCEL_ONLINE, &arg); + remove_pfn_range_from_zone(zone, pfn, nr_pages); + mem_hotplug_done(); + return ret; +} +#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ + +static void reset_node_present_pages(pg_data_t *pgdat) +{ + struct zone *z; + + for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++) + z->present_pages = 0; + + pgdat->node_present_pages = 0; +} + +/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ +static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start) +{ + struct pglist_data *pgdat; + unsigned long start_pfn = PFN_DOWN(start); + + pgdat = NODE_DATA(nid); + if (!pgdat) { + pgdat = arch_alloc_nodedata(nid); + if (!pgdat) + return NULL; + + arch_refresh_nodedata(nid, pgdat); + } else { + /* + * Reset the nr_zones, order and classzone_idx before reuse. + * Note that kswapd will init kswapd_classzone_idx properly + * when it starts in the near future. + */ + pgdat->nr_zones = 0; + pgdat->kswapd_order = 0; + pgdat->kswapd_classzone_idx = 0; + } + + /* we can use NODE_DATA(nid) from here */ + + pgdat->node_id = nid; + pgdat->node_start_pfn = start_pfn; + + /* init node's zones as empty zones, we don't have any present pages.*/ + free_area_init_core_hotplug(nid); + pgdat->per_cpu_nodestats = alloc_percpu(struct per_cpu_nodestat); + + /* + * The node we allocated has no zone fallback lists. For avoiding + * to access not-initialized zonelist, build here. + */ + build_all_zonelists(pgdat); + + /* + * When memory is hot-added, all the memory is in offline state. So + * clear all zones' present_pages because they will be updated in + * online_pages() and offline_pages(). + */ + reset_node_managed_pages(pgdat); + reset_node_present_pages(pgdat); + + return pgdat; +} + +static void rollback_node_hotadd(int nid) +{ + pg_data_t *pgdat = NODE_DATA(nid); + + arch_refresh_nodedata(nid, NULL); + free_percpu(pgdat->per_cpu_nodestats); + arch_free_nodedata(pgdat); + return; +} + + +/** + * try_online_node - online a node if offlined + * @nid: the node ID + * @start: start addr of the node + * @set_node_online: Whether we want to online the node + * called by cpu_up() to online a node without onlined memory. + * + * Returns: + * 1 -> a new node has been allocated + * 0 -> the node is already online + * -ENOMEM -> the node could not be allocated + */ +static int __try_online_node(int nid, u64 start, bool set_node_online) +{ + pg_data_t *pgdat; + int ret = 1; + + if (node_online(nid)) + return 0; + + pgdat = hotadd_new_pgdat(nid, start); + if (!pgdat) { + pr_err("Cannot online node %d due to NULL pgdat\n", nid); + ret = -ENOMEM; + goto out; + } + + if (set_node_online) { + node_set_online(nid); + ret = register_one_node(nid); + BUG_ON(ret); + } +out: + return ret; +} + +/* + * Users of this function always want to online/register the node + */ +int try_online_node(int nid) +{ + int ret; + + mem_hotplug_begin(); + ret = __try_online_node(nid, 0, true); + mem_hotplug_done(); + return ret; +} + +static int check_hotplug_memory_range(u64 start, u64 size) +{ + unsigned long block_sz = memory_block_size_bytes(); + u64 block_nr_pages = block_sz >> PAGE_SHIFT; + u64 nr_pages = size >> PAGE_SHIFT; + u64 start_pfn = PFN_DOWN(start); + + /* memory range must be block size aligned */ + if (!nr_pages || !IS_ALIGNED(start_pfn, block_nr_pages) || + !IS_ALIGNED(nr_pages, block_nr_pages)) { + pr_err("Block size [%#lx] unaligned hotplug range: start %#llx, size %#llx", + block_sz, start, size); + return -EINVAL; + } + + return 0; +} + +static int online_memory_block(struct memory_block *mem, void *arg) +{ + return device_online(&mem->dev); +} + +/* + * NOTE: The caller must call lock_device_hotplug() to serialize hotplug + * and online/offline operations (triggered e.g. by sysfs). + * + * we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG + */ +int __ref add_memory_resource(int nid, struct resource *res, bool online) +{ + u64 start, size; + bool new_node = false; + int ret; + + start = res->start; + size = resource_size(res); + + ret = check_hotplug_memory_range(start, size); + if (ret) + return ret; + + mem_hotplug_begin(); + + /* + * Add new range to memblock so that when hotadd_new_pgdat() is called + * to allocate new pgdat, get_pfn_range_for_nid() will be able to find + * this new range and calculate total pages correctly. The range will + * be removed at hot-remove time. + */ + memblock_add_node(start, size, nid); + + ret = __try_online_node(nid, start, false); + if (ret < 0) + goto error; + new_node = ret; + + /* call arch's memory hotadd */ + ret = arch_add_memory(nid, start, size, NULL, true); + if (ret < 0) + goto error; + + /* create memory block devices after memory was added */ + ret = create_memory_block_devices(start, size); + if (ret) { + arch_remove_memory(nid, start, size, NULL); + goto error; + } + + if (new_node) { + /* If sysfs file of new node can't be created, cpu on the node + * can't be hot-added. There is no rollback way now. + * So, check by BUG_ON() to catch it reluctantly.. + * We online node here. We can't roll back from here. + */ + node_set_online(nid); + ret = __register_one_node(nid); + BUG_ON(ret); + } + + /* link memory sections under this node.*/ + ret = link_mem_sections(nid, PFN_DOWN(start), PFN_UP(start + size - 1), + MEMINIT_HOTPLUG); + BUG_ON(ret); + + /* create new memmap entry */ + firmware_map_add_hotplug(start, start + size, "System RAM"); + + /* device_online() will take the lock when calling online_pages() */ + mem_hotplug_done(); + + /* online pages if requested */ + if (online) + walk_memory_range(PFN_DOWN(start), PFN_UP(start + size - 1), + NULL, online_memory_block); + + return ret; +error: + /* rollback pgdat allocation and others */ + if (new_node) + rollback_node_hotadd(nid); + memblock_remove(start, size); + mem_hotplug_done(); + return ret; +} + +/* requires device_hotplug_lock, see add_memory_resource() */ +int __ref __add_memory(int nid, u64 start, u64 size) +{ + struct resource *res; + int ret; + + res = register_memory_resource(start, size); + if (IS_ERR(res)) + return PTR_ERR(res); + + ret = add_memory_resource(nid, res, memhp_auto_online); + if (ret < 0) + release_memory_resource(res); + return ret; +} + +int add_memory(int nid, u64 start, u64 size) +{ + int rc; + + lock_device_hotplug(); + rc = __add_memory(nid, start, size); + unlock_device_hotplug(); + + return rc; +} +EXPORT_SYMBOL_GPL(add_memory); + +#ifdef CONFIG_MEMORY_HOTREMOVE +/* + * A free page on the buddy free lists (not the per-cpu lists) has PageBuddy + * set and the size of the free page is given by page_order(). Using this, + * the function determines if the pageblock contains only free pages. + * Due to buddy contraints, a free page at least the size of a pageblock will + * be located at the start of the pageblock + */ +static inline int pageblock_free(struct page *page) +{ + return PageBuddy(page) && page_order(page) >= pageblock_order; +} + +/* Return the pfn of the start of the next active pageblock after a given pfn */ +static unsigned long next_active_pageblock(unsigned long pfn) +{ + struct page *page = pfn_to_page(pfn); + + /* Ensure the starting page is pageblock-aligned */ + BUG_ON(pfn & (pageblock_nr_pages - 1)); + + /* If the entire pageblock is free, move to the end of free page */ + if (pageblock_free(page)) { + int order; + /* be careful. we don't have locks, page_order can be changed.*/ + order = page_order(page); + if ((order < MAX_ORDER) && (order >= pageblock_order)) + return pfn + (1 << order); + } + + return pfn + pageblock_nr_pages; +} + +static bool is_pageblock_removable_nolock(unsigned long pfn) +{ + struct page *page = pfn_to_page(pfn); + struct zone *zone; + + /* + * We have to be careful here because we are iterating over memory + * sections which are not zone aware so we might end up outside of + * the zone but still within the section. + * We have to take care about the node as well. If the node is offline + * its NODE_DATA will be NULL - see page_zone. + */ + if (!node_online(page_to_nid(page))) + return false; + + zone = page_zone(page); + pfn = page_to_pfn(page); + if (!zone_spans_pfn(zone, pfn)) + return false; + + return !has_unmovable_pages(zone, page, 0, MIGRATE_MOVABLE, true); +} + +/* Checks if this range of memory is likely to be hot-removable. */ +bool is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages) +{ + unsigned long end_pfn, pfn; + + end_pfn = min(start_pfn + nr_pages, + zone_end_pfn(page_zone(pfn_to_page(start_pfn)))); + + /* Check the starting page of each pageblock within the range */ + for (pfn = start_pfn; pfn < end_pfn; pfn = next_active_pageblock(pfn)) { + if (!is_pageblock_removable_nolock(pfn)) + return false; + cond_resched(); + } + + /* All pageblocks in the memory block are likely to be hot-removable */ + return true; +} + +/* + * Confirm all pages in a range [start, end) belong to the same zone. + * When true, return its valid [start, end). + */ +int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn, + unsigned long *valid_start, unsigned long *valid_end) +{ + unsigned long pfn, sec_end_pfn; + unsigned long start, end; + struct zone *zone = NULL; + struct page *page; + int i; + for (pfn = start_pfn, sec_end_pfn = SECTION_ALIGN_UP(start_pfn + 1); + pfn < end_pfn; + pfn = sec_end_pfn, sec_end_pfn += PAGES_PER_SECTION) { + /* Make sure the memory section is present first */ + if (!present_section_nr(pfn_to_section_nr(pfn))) + continue; + for (; pfn < sec_end_pfn && pfn < end_pfn; + pfn += MAX_ORDER_NR_PAGES) { + i = 0; + /* This is just a CONFIG_HOLES_IN_ZONE check.*/ + while ((i < MAX_ORDER_NR_PAGES) && + !pfn_valid_within(pfn + i)) + i++; + if (i == MAX_ORDER_NR_PAGES || pfn + i >= end_pfn) + continue; + /* Check if we got outside of the zone */ + if (zone && !zone_spans_pfn(zone, pfn + i)) + return 0; + page = pfn_to_page(pfn + i); + if (zone && page_zone(page) != zone) + return 0; + if (!zone) + start = pfn + i; + zone = page_zone(page); + end = pfn + MAX_ORDER_NR_PAGES; + } + } + + if (zone) { + *valid_start = start; + *valid_end = min(end, end_pfn); + return 1; + } else { + return 0; + } +} + +/* + * Scan pfn range [start,end) to find movable/migratable pages (LRU pages, + * non-lru movable pages and hugepages). We scan pfn because it's much + * easier than scanning over linked list. This function returns the pfn + * of the first found movable page if it's found, otherwise 0. + */ +static unsigned long scan_movable_pages(unsigned long start, unsigned long end) +{ + unsigned long pfn; + + for (pfn = start; pfn < end; pfn++) { + struct page *page, *head; + unsigned long skip; + + if (!pfn_valid(pfn)) + continue; + page = pfn_to_page(pfn); + if (PageLRU(page)) + return pfn; + if (__PageMovable(page)) + return pfn; + + if (!PageHuge(page)) + continue; + head = compound_head(page); + if (hugepage_migration_supported(page_hstate(head)) && + page_huge_active(head)) + return pfn; + skip = (1 << compound_order(head)) - (page - head); + pfn += skip - 1; + } + return 0; +} + +static struct page *new_node_page(struct page *page, unsigned long private) +{ + int nid = page_to_nid(page); + nodemask_t nmask = node_states[N_MEMORY]; + + /* + * try to allocate from a different node but reuse this node if there + * are no other online nodes to be used (e.g. we are offlining a part + * of the only existing node) + */ + node_clear(nid, nmask); + if (nodes_empty(nmask)) + node_set(nid, nmask); + + return new_page_nodemask(page, nid, &nmask); +} + +#define NR_OFFLINE_AT_ONCE_PAGES (256) +static int +do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) +{ + unsigned long pfn; + struct page *page; + int move_pages = NR_OFFLINE_AT_ONCE_PAGES; + int not_managed = 0; + int ret = 0; + LIST_HEAD(source); + + for (pfn = start_pfn; pfn < end_pfn && move_pages > 0; pfn++) { + if (!pfn_valid(pfn)) + continue; + page = pfn_to_page(pfn); + + if (PageHuge(page)) { + struct page *head = compound_head(page); + pfn = page_to_pfn(head) + (1<<compound_order(head)) - 1; + if (compound_order(head) > PFN_SECTION_SHIFT) { + ret = -EBUSY; + break; + } + if (isolate_huge_page(page, &source)) + move_pages -= 1 << compound_order(head); + continue; + } else if (PageTransHuge(page)) + pfn = page_to_pfn(compound_head(page)) + + hpage_nr_pages(page) - 1; + + /* + * HWPoison pages have elevated reference counts so the migration would + * fail on them. It also doesn't make any sense to migrate them in the + * first place. Still try to unmap such a page in case it is still mapped + * (e.g. current hwpoison implementation doesn't unmap KSM pages but keep + * the unmap as the catch all safety net). + */ + if (PageHWPoison(page)) { + if (WARN_ON(PageLRU(page))) + isolate_lru_page(page); + if (page_mapped(page)) + try_to_unmap(page, TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS); + continue; + } + + if (!get_page_unless_zero(page)) + continue; + /* + * We can skip free pages. And we can deal with pages on + * LRU and non-lru movable pages. + */ + if (PageLRU(page)) + ret = isolate_lru_page(page); + else + ret = isolate_movable_page(page, ISOLATE_UNEVICTABLE); + if (!ret) { /* Success */ + put_page(page); + list_add_tail(&page->lru, &source); + move_pages--; + if (!__PageMovable(page)) + inc_node_page_state(page, NR_ISOLATED_ANON + + page_is_file_cache(page)); + + } else { +#ifdef CONFIG_DEBUG_VM + pr_alert("failed to isolate pfn %lx\n", pfn); + dump_page(page, "isolation failed"); +#endif + put_page(page); + /* Because we don't have big zone->lock. we should + check this again here. */ + if (page_count(page)) { + not_managed++; + ret = -EBUSY; + break; + } + } + } + if (!list_empty(&source)) { + if (not_managed) { + putback_movable_pages(&source); + goto out; + } + + /* Allocate a new page from the nearest neighbor node */ + ret = migrate_pages(&source, new_node_page, NULL, 0, + MIGRATE_SYNC, MR_MEMORY_HOTPLUG); + if (ret) + putback_movable_pages(&source); + } +out: + return ret; +} + +/* + * remove from free_area[] and mark all as Reserved. + */ +static int +offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages, + void *data) +{ + __offline_isolated_pages(start, start + nr_pages); + return 0; +} + +static void +offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) +{ + walk_system_ram_range(start_pfn, end_pfn - start_pfn, NULL, + offline_isolated_pages_cb); +} + +/* + * Check all pages in range, recoreded as memory resource, are isolated. + */ +static int +check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages, + void *data) +{ + int ret; + long offlined = *(long *)data; + ret = test_pages_isolated(start_pfn, start_pfn + nr_pages, true); + offlined = nr_pages; + if (!ret) + *(long *)data += offlined; + return ret; +} + +static long +check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn) +{ + long offlined = 0; + int ret; + + ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn, &offlined, + check_pages_isolated_cb); + if (ret < 0) + offlined = (long)ret; + return offlined; +} + +static int __init cmdline_parse_movable_node(char *p) +{ +#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP + movable_node_enabled = true; +#else + pr_warn("movable_node parameter depends on CONFIG_HAVE_MEMBLOCK_NODE_MAP to work properly\n"); +#endif + return 0; +} +early_param("movable_node", cmdline_parse_movable_node); + +/* check which state of node_states will be changed when offline memory */ +static void node_states_check_changes_offline(unsigned long nr_pages, + struct zone *zone, struct memory_notify *arg) +{ + struct pglist_data *pgdat = zone->zone_pgdat; + unsigned long present_pages = 0; + enum zone_type zt, zone_last = ZONE_NORMAL; + + /* + * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY] + * contains nodes which have zones of 0...ZONE_NORMAL, + * set zone_last to ZONE_NORMAL. + * + * If we don't have HIGHMEM nor movable node, + * node_states[N_NORMAL_MEMORY] contains nodes which have zones of + * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE. + */ + if (N_MEMORY == N_NORMAL_MEMORY) + zone_last = ZONE_MOVABLE; + + /* + * check whether node_states[N_NORMAL_MEMORY] will be changed. + * If the memory to be offline is in a zone of 0...zone_last, + * and it is the last present memory, 0...zone_last will + * become empty after offline , thus we can determind we will + * need to clear the node from node_states[N_NORMAL_MEMORY]. + */ + for (zt = 0; zt <= zone_last; zt++) + present_pages += pgdat->node_zones[zt].present_pages; + if (zone_idx(zone) <= zone_last && nr_pages >= present_pages) + arg->status_change_nid_normal = zone_to_nid(zone); + else + arg->status_change_nid_normal = -1; + +#ifdef CONFIG_HIGHMEM + /* + * If we have movable node, node_states[N_HIGH_MEMORY] + * contains nodes which have zones of 0...ZONE_HIGHMEM, + * set zone_last to ZONE_HIGHMEM. + * + * If we don't have movable node, node_states[N_NORMAL_MEMORY] + * contains nodes which have zones of 0...ZONE_MOVABLE, + * set zone_last to ZONE_MOVABLE. + */ + zone_last = ZONE_HIGHMEM; + if (N_MEMORY == N_HIGH_MEMORY) + zone_last = ZONE_MOVABLE; + + for (; zt <= zone_last; zt++) + present_pages += pgdat->node_zones[zt].present_pages; + if (zone_idx(zone) <= zone_last && nr_pages >= present_pages) + arg->status_change_nid_high = zone_to_nid(zone); + else + arg->status_change_nid_high = -1; +#else + arg->status_change_nid_high = arg->status_change_nid_normal; +#endif + + /* + * node_states[N_HIGH_MEMORY] contains nodes which have 0...ZONE_MOVABLE + */ + zone_last = ZONE_MOVABLE; + + /* + * check whether node_states[N_HIGH_MEMORY] will be changed + * If we try to offline the last present @nr_pages from the node, + * we can determind we will need to clear the node from + * node_states[N_HIGH_MEMORY]. + */ + for (; zt <= zone_last; zt++) + present_pages += pgdat->node_zones[zt].present_pages; + if (nr_pages >= present_pages) + arg->status_change_nid = zone_to_nid(zone); + else + arg->status_change_nid = -1; +} + +static void node_states_clear_node(int node, struct memory_notify *arg) +{ + if (arg->status_change_nid_normal >= 0) + node_clear_state(node, N_NORMAL_MEMORY); + + if ((N_MEMORY != N_NORMAL_MEMORY) && + (arg->status_change_nid_high >= 0)) + node_clear_state(node, N_HIGH_MEMORY); + + if ((N_MEMORY != N_HIGH_MEMORY) && + (arg->status_change_nid >= 0)) + node_clear_state(node, N_MEMORY); +} + +static int __ref __offline_pages(unsigned long start_pfn, + unsigned long end_pfn) +{ + unsigned long pfn, nr_pages; + long offlined_pages; + int ret, node; + unsigned long flags; + unsigned long valid_start, valid_end; + struct zone *zone; + struct memory_notify arg; + + /* at least, alignment against pageblock is necessary */ + if (!IS_ALIGNED(start_pfn, pageblock_nr_pages)) + return -EINVAL; + if (!IS_ALIGNED(end_pfn, pageblock_nr_pages)) + return -EINVAL; + + mem_hotplug_begin(); + + /* This makes hotplug much easier...and readable. + we assume this for now. .*/ + if (!test_pages_in_a_zone(start_pfn, end_pfn, &valid_start, + &valid_end)) { + mem_hotplug_done(); + return -EINVAL; + } + + zone = page_zone(pfn_to_page(valid_start)); + node = zone_to_nid(zone); + nr_pages = end_pfn - start_pfn; + + /* set above range as isolated */ + ret = start_isolate_page_range(start_pfn, end_pfn, + MIGRATE_MOVABLE, true); + if (ret) { + mem_hotplug_done(); + return ret; + } + + arg.start_pfn = start_pfn; + arg.nr_pages = nr_pages; + node_states_check_changes_offline(nr_pages, zone, &arg); + + ret = memory_notify(MEM_GOING_OFFLINE, &arg); + ret = notifier_to_errno(ret); + if (ret) + goto failed_removal; + + pfn = start_pfn; +repeat: + /* start memory hot removal */ + ret = -EINTR; + if (signal_pending(current)) + goto failed_removal; + + cond_resched(); + lru_add_drain_all(); + drain_all_pages(zone); + + pfn = scan_movable_pages(start_pfn, end_pfn); + if (pfn) { /* We have movable pages */ + ret = do_migrate_range(pfn, end_pfn); + goto repeat; + } + + /* + * dissolve free hugepages in the memory block before doing offlining + * actually in order to make hugetlbfs's object counting consistent. + */ + ret = dissolve_free_huge_pages(start_pfn, end_pfn); + if (ret) + goto failed_removal; + /* check again */ + offlined_pages = check_pages_isolated(start_pfn, end_pfn); + if (offlined_pages < 0) + goto repeat; + pr_info("Offlined Pages %ld\n", offlined_pages); + /* Ok, all of our target is isolated. + We cannot do rollback at this point. */ + offline_isolated_pages(start_pfn, end_pfn); + /* reset pagetype flags and makes migrate type to be MOVABLE */ + undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE); + /* removal success */ + adjust_managed_page_count(pfn_to_page(start_pfn), -offlined_pages); + zone->present_pages -= offlined_pages; + + pgdat_resize_lock(zone->zone_pgdat, &flags); + zone->zone_pgdat->node_present_pages -= offlined_pages; + pgdat_resize_unlock(zone->zone_pgdat, &flags); + + init_per_zone_wmark_min(); + + if (!populated_zone(zone)) { + zone_pcp_reset(zone); + build_all_zonelists(NULL); + } else + zone_pcp_update(zone); + + node_states_clear_node(node, &arg); + if (arg.status_change_nid >= 0) { + kswapd_stop(node); + kcompactd_stop(node); + } + + vm_total_pages = nr_free_pagecache_pages(); + writeback_set_ratelimit(); + + memory_notify(MEM_OFFLINE, &arg); + remove_pfn_range_from_zone(zone, start_pfn, nr_pages); + mem_hotplug_done(); + return 0; + +failed_removal: + pr_debug("memory offlining [mem %#010llx-%#010llx] failed\n", + (unsigned long long) start_pfn << PAGE_SHIFT, + ((unsigned long long) end_pfn << PAGE_SHIFT) - 1); + memory_notify(MEM_CANCEL_OFFLINE, &arg); + /* pushback to free area */ + undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE); + mem_hotplug_done(); + return ret; +} + +int offline_pages(unsigned long start_pfn, unsigned long nr_pages) +{ + return __offline_pages(start_pfn, start_pfn + nr_pages); +} +#endif /* CONFIG_MEMORY_HOTREMOVE */ + +/** + * walk_memory_range - walks through all mem sections in [start_pfn, end_pfn) + * @start_pfn: start pfn of the memory range + * @end_pfn: end pfn of the memory range + * @arg: argument passed to func + * @func: callback for each memory section walked + * + * This function walks through all present mem sections in range + * [start_pfn, end_pfn) and call func on each mem section. + * + * Returns the return value of func. + */ +int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn, + void *arg, int (*func)(struct memory_block *, void *)) +{ + struct memory_block *mem = NULL; + struct mem_section *section; + unsigned long pfn, section_nr; + int ret; + + for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { + section_nr = pfn_to_section_nr(pfn); + if (!present_section_nr(section_nr)) + continue; + + section = __nr_to_section(section_nr); + /* same memblock? */ + if (mem) + if ((section_nr >= mem->start_section_nr) && + (section_nr <= mem->end_section_nr)) + continue; + + mem = find_memory_block_hinted(section, mem); + if (!mem) + continue; + + ret = func(mem, arg); + if (ret) { + kobject_put(&mem->dev.kobj); + return ret; + } + } + + if (mem) + kobject_put(&mem->dev.kobj); + + return 0; +} + +#ifdef CONFIG_MEMORY_HOTREMOVE +static int check_memblock_offlined_cb(struct memory_block *mem, void *arg) +{ + int ret = !is_memblock_offlined(mem); + + if (unlikely(ret)) { + phys_addr_t beginpa, endpa; + + beginpa = PFN_PHYS(section_nr_to_pfn(mem->start_section_nr)); + endpa = PFN_PHYS(section_nr_to_pfn(mem->end_section_nr + 1))-1; + pr_warn("removing memory fails, because memory [%pa-%pa] is onlined\n", + &beginpa, &endpa); + } + + return ret; +} + +static int check_cpu_on_node(pg_data_t *pgdat) +{ + int cpu; + + for_each_present_cpu(cpu) { + if (cpu_to_node(cpu) == pgdat->node_id) + /* + * the cpu on this node isn't removed, and we can't + * offline this node. + */ + return -EBUSY; + } + + return 0; +} + +static void unmap_cpu_on_node(pg_data_t *pgdat) +{ +#ifdef CONFIG_ACPI_NUMA + int cpu; + + for_each_possible_cpu(cpu) + if (cpu_to_node(cpu) == pgdat->node_id) + numa_clear_node(cpu); +#endif +} + +static int check_and_unmap_cpu_on_node(pg_data_t *pgdat) +{ + int ret; + + ret = check_cpu_on_node(pgdat); + if (ret) + return ret; + + /* + * the node will be offlined when we come here, so we can clear + * the cpu_to_node() now. + */ + + unmap_cpu_on_node(pgdat); + return 0; +} + +static int check_no_memblock_for_node_cb(struct memory_block *mem, void *arg) +{ + int nid = *(int *)arg; + + /* + * If a memory block belongs to multiple nodes, the stored nid is not + * reliable. However, such blocks are always online (e.g., cannot get + * offlined) and, therefore, are still spanned by the node. + */ + return mem->nid == nid ? -EEXIST : 0; +} + +/** + * try_offline_node + * @nid: the node ID + * + * Offline a node if all memory sections and cpus of the node are removed. + * + * NOTE: The caller must call lock_device_hotplug() to serialize hotplug + * and online/offline operations before this call. + */ +void try_offline_node(int nid) +{ + pg_data_t *pgdat = NODE_DATA(nid); + int rc; + + /* + * If the node still spans pages (especially ZONE_DEVICE), don't + * offline it. A node spans memory after move_pfn_range_to_zone(), + * e.g., after the memory block was onlined. + */ + if (pgdat->node_spanned_pages) + return; + + /* + * Especially offline memory blocks might not be spanned by the + * node. They will get spanned by the node once they get onlined. + * However, they link to the node in sysfs and can get onlined later. + */ + rc = for_each_memory_block(&nid, check_no_memblock_for_node_cb); + if (rc) + return; + + if (check_and_unmap_cpu_on_node(pgdat)) + return; + + /* + * all memory/cpu of this node are removed, we can offline this + * node now. + */ + node_set_offline(nid); + unregister_one_node(nid); +} +EXPORT_SYMBOL(try_offline_node); + +static void __release_memory_resource(resource_size_t start, + resource_size_t size) +{ + int ret; + + /* + * When removing memory in the same granularity as it was added, + * this function never fails. It might only fail if resources + * have to be adjusted or split. We'll ignore the error, as + * removing of memory cannot fail. + */ + ret = release_mem_region_adjustable(&iomem_resource, start, size); + if (ret) { + resource_size_t endres = start + size - 1; + + pr_warn("Unable to release resource <%pa-%pa> (%d)\n", + &start, &endres, ret); + } +} + +/** + * remove_memory + * @nid: the node ID + * @start: physical address of the region to remove + * @size: size of the region to remove + * + * NOTE: The caller must call lock_device_hotplug() to serialize hotplug + * and online/offline operations before this call, as required by + * try_offline_node(). + */ +void __ref __remove_memory(int nid, u64 start, u64 size) +{ + int ret; + + BUG_ON(check_hotplug_memory_range(start, size)); + + /* + * All memory blocks must be offlined before removing memory. Check + * whether all memory blocks in question are offline and trigger a BUG() + * if this is not the case. + */ + ret = walk_memory_range(PFN_DOWN(start), PFN_UP(start + size - 1), NULL, + check_memblock_offlined_cb); + if (ret) + BUG(); + + /* remove memmap entry */ + firmware_map_remove(start, start + size, "System RAM"); + memblock_free(start, size); + memblock_remove(start, size); + + /* + * Memory block device removal under the device_hotplug_lock is + * a barrier against racing online attempts. + */ + remove_memory_block_devices(start, size); + + mem_hotplug_begin(); + + arch_remove_memory(nid, start, size, NULL); + __release_memory_resource(start, size); + + try_offline_node(nid); + + mem_hotplug_done(); +} + +void remove_memory(int nid, u64 start, u64 size) +{ + lock_device_hotplug(); + __remove_memory(nid, start, size); + unlock_device_hotplug(); +} +EXPORT_SYMBOL_GPL(remove_memory); +#endif /* CONFIG_MEMORY_HOTREMOVE */ |