diff options
Diffstat (limited to 'mm/memory_hotplug.c')
| -rw-r--r-- | mm/memory_hotplug.c | 2015 |
1 files changed, 2015 insertions, 0 deletions
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c new file mode 100644 index 000000000..9e88f749a --- /dev/null +++ b/mm/memory_hotplug.c @@ -0,0 +1,2015 @@ +/* + * 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/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/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 <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); + +/* The same as the cpu_hotplug lock, but for memory hotplug. */ +static struct { + struct task_struct *active_writer; + struct mutex lock; /* Synchronizes accesses to refcount, */ + /* + * Also blocks the new readers during + * an ongoing mem hotplug operation. + */ + int refcount; + +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; +#endif +} mem_hotplug = { + .active_writer = NULL, + .lock = __MUTEX_INITIALIZER(mem_hotplug.lock), + .refcount = 0, +#ifdef CONFIG_DEBUG_LOCK_ALLOC + .dep_map = {.name = "mem_hotplug.lock" }, +#endif +}; + +/* Lockdep annotations for get/put_online_mems() and mem_hotplug_begin/end() */ +#define memhp_lock_acquire_read() lock_map_acquire_read(&mem_hotplug.dep_map) +#define memhp_lock_acquire() lock_map_acquire(&mem_hotplug.dep_map) +#define memhp_lock_release() lock_map_release(&mem_hotplug.dep_map) + +void get_online_mems(void) +{ + might_sleep(); + if (mem_hotplug.active_writer == current) + return; + memhp_lock_acquire_read(); + mutex_lock(&mem_hotplug.lock); + mem_hotplug.refcount++; + mutex_unlock(&mem_hotplug.lock); + +} + +void put_online_mems(void) +{ + if (mem_hotplug.active_writer == current) + return; + mutex_lock(&mem_hotplug.lock); + + if (WARN_ON(!mem_hotplug.refcount)) + mem_hotplug.refcount++; /* try to fix things up */ + + if (!--mem_hotplug.refcount && unlikely(mem_hotplug.active_writer)) + wake_up_process(mem_hotplug.active_writer); + mutex_unlock(&mem_hotplug.lock); + memhp_lock_release(); + +} + +void mem_hotplug_begin(void) +{ + mem_hotplug.active_writer = current; + + memhp_lock_acquire(); + for (;;) { + mutex_lock(&mem_hotplug.lock); + if (likely(!mem_hotplug.refcount)) + break; + __set_current_state(TASK_UNINTERRUPTIBLE); + mutex_unlock(&mem_hotplug.lock); + schedule(); + } +} + +void mem_hotplug_done(void) +{ + mem_hotplug.active_writer = NULL; + mutex_unlock(&mem_hotplug.lock); + memhp_lock_release(); +} + +/* 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 | IORESOURCE_BUSY; + if (request_resource(&iomem_resource, res) < 0) { + pr_debug("System RAM resource %pR cannot be added\n", res); + 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 +void get_page_bootmem(unsigned long info, struct page *page, + unsigned long type) +{ + page->lru.next = (struct list_head *) type; + SetPagePrivate(page); + set_page_private(page, info); + atomic_inc(&page->_count); +} + +void put_page_bootmem(struct page *page) +{ + unsigned long type; + + type = (unsigned long) page->lru.next; + BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE || + type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE); + + if (atomic_dec_return(&page->_count) == 1) { + 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 = __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_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; + + if (!pfn_valid(start_pfn)) + return; + + 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 = __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_SECTION_INFO); +} +#endif /* !CONFIG_SPARSEMEM_VMEMMAP */ + +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_is_initialized(zone)) { + 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 = 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) && (pfn_to_nid(pfn) == node)) + register_page_bootmem_info_section(pfn); + } +} +#endif /* CONFIG_HAVE_BOOTMEM_INFO_NODE */ + +static void __meminit 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_end_pfn(zone); + if (zone_is_empty(zone) || 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 resize_zone(struct zone *zone, unsigned long start_pfn, + unsigned long end_pfn) +{ + zone_span_writelock(zone); + + if (end_pfn - start_pfn) { + zone->zone_start_pfn = start_pfn; + zone->spanned_pages = end_pfn - start_pfn; + } else { + /* + * make it consist as free_area_init_core(), + * if spanned_pages = 0, then keep start_pfn = 0 + */ + zone->zone_start_pfn = 0; + zone->spanned_pages = 0; + } + + zone_span_writeunlock(zone); +} + +static void fix_zone_id(struct zone *zone, unsigned long start_pfn, + unsigned long end_pfn) +{ + enum zone_type zid = zone_idx(zone); + int nid = zone->zone_pgdat->node_id; + unsigned long pfn; + + for (pfn = start_pfn; pfn < end_pfn; pfn++) + set_page_links(pfn_to_page(pfn), zid, nid, pfn); +} + +/* Can fail with -ENOMEM from allocating a wait table with vmalloc() or + * alloc_bootmem_node_nopanic()/memblock_virt_alloc_node_nopanic() */ +static int __ref ensure_zone_is_initialized(struct zone *zone, + unsigned long start_pfn, unsigned long num_pages) +{ + if (!zone_is_initialized(zone)) + return init_currently_empty_zone(zone, start_pfn, num_pages, + MEMMAP_HOTPLUG); + return 0; +} + +static int __meminit move_pfn_range_left(struct zone *z1, struct zone *z2, + unsigned long start_pfn, unsigned long end_pfn) +{ + int ret; + unsigned long flags; + unsigned long z1_start_pfn; + + ret = ensure_zone_is_initialized(z1, start_pfn, end_pfn - start_pfn); + if (ret) + return ret; + + pgdat_resize_lock(z1->zone_pgdat, &flags); + + /* can't move pfns which are higher than @z2 */ + if (end_pfn > zone_end_pfn(z2)) + goto out_fail; + /* the move out part must be at the left most of @z2 */ + if (start_pfn > z2->zone_start_pfn) + goto out_fail; + /* must included/overlap */ + if (end_pfn <= z2->zone_start_pfn) + goto out_fail; + + /* use start_pfn for z1's start_pfn if z1 is empty */ + if (!zone_is_empty(z1)) + z1_start_pfn = z1->zone_start_pfn; + else + z1_start_pfn = start_pfn; + + resize_zone(z1, z1_start_pfn, end_pfn); + resize_zone(z2, end_pfn, zone_end_pfn(z2)); + + pgdat_resize_unlock(z1->zone_pgdat, &flags); + + fix_zone_id(z1, start_pfn, end_pfn); + + return 0; +out_fail: + pgdat_resize_unlock(z1->zone_pgdat, &flags); + return -1; +} + +static int __meminit move_pfn_range_right(struct zone *z1, struct zone *z2, + unsigned long start_pfn, unsigned long end_pfn) +{ + int ret; + unsigned long flags; + unsigned long z2_end_pfn; + + ret = ensure_zone_is_initialized(z2, start_pfn, end_pfn - start_pfn); + if (ret) + return ret; + + pgdat_resize_lock(z1->zone_pgdat, &flags); + + /* can't move pfns which are lower than @z1 */ + if (z1->zone_start_pfn > start_pfn) + goto out_fail; + /* the move out part mast at the right most of @z1 */ + if (zone_end_pfn(z1) > end_pfn) + goto out_fail; + /* must included/overlap */ + if (start_pfn >= zone_end_pfn(z1)) + goto out_fail; + + /* use end_pfn for z2's end_pfn if z2 is empty */ + if (!zone_is_empty(z2)) + z2_end_pfn = zone_end_pfn(z2); + else + z2_end_pfn = end_pfn; + + resize_zone(z1, z1->zone_start_pfn, start_pfn); + resize_zone(z2, start_pfn, z2_end_pfn); + + pgdat_resize_unlock(z1->zone_pgdat, &flags); + + fix_zone_id(z2, start_pfn, end_pfn); + + return 0; +out_fail: + pgdat_resize_unlock(z1->zone_pgdat, &flags); + return -1; +} + +static void __meminit grow_pgdat_span(struct pglist_data *pgdat, unsigned long start_pfn, + unsigned long end_pfn) +{ + unsigned long old_pgdat_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(old_pgdat_end_pfn, end_pfn) - + pgdat->node_start_pfn; +} + +static int __meminit __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; + unsigned long flags; + int ret; + + zone_type = zone - pgdat->node_zones; + ret = ensure_zone_is_initialized(zone, phys_start_pfn, nr_pages); + if (ret) + return ret; + + pgdat_resize_lock(zone->zone_pgdat, &flags); + grow_zone_span(zone, phys_start_pfn, phys_start_pfn + nr_pages); + grow_pgdat_span(zone->zone_pgdat, phys_start_pfn, + phys_start_pfn + nr_pages); + pgdat_resize_unlock(zone->zone_pgdat, &flags); + memmap_init_zone(nr_pages, nid, zone_type, + phys_start_pfn, MEMMAP_HOTPLUG); + return 0; +} + +static int __meminit __add_section(int nid, struct zone *zone, + unsigned long phys_start_pfn) +{ + int ret; + + if (pfn_valid(phys_start_pfn)) + return -EEXIST; + + ret = sparse_add_one_section(zone, phys_start_pfn); + + if (ret < 0) + return ret; + + ret = __add_zone(zone, phys_start_pfn); + + if (ret < 0) + return ret; + + return register_new_memory(nid, __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 __ref __add_pages(int nid, 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(nid, zone, section_nr_to_pfn(i)); + + /* + * 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; + } + + return err; +} +EXPORT_SYMBOL_GPL(__add_pages); + +#ifdef CONFIG_MEMORY_HOTREMOVE +/* find the smallest valid pfn in the range [start_pfn, end_pfn) */ +static int find_smallest_section_pfn(int nid, struct zone *zone, + unsigned long start_pfn, + unsigned long end_pfn) +{ + struct mem_section *ms; + + for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SECTION) { + ms = __pfn_to_section(start_pfn); + + if (unlikely(!valid_section(ms))) + 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 int find_biggest_section_pfn(int nid, struct zone *zone, + unsigned long start_pfn, + unsigned long end_pfn) +{ + struct mem_section *ms; + unsigned long pfn; + + /* pfn is the end pfn of a memory section. */ + pfn = end_pfn - 1; + for (; pfn >= start_pfn; pfn -= PAGES_PER_SECTION) { + ms = __pfn_to_section(pfn); + + if (unlikely(!valid_section(ms))) + 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; + struct mem_section *ms; + 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) { + ms = __pfn_to_section(pfn); + + if (unlikely(!valid_section(ms))) + 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 shrink_pgdat_span(struct pglist_data *pgdat, + unsigned long start_pfn, unsigned long end_pfn) +{ + unsigned long pgdat_start_pfn = pgdat->node_start_pfn; + unsigned long p = pgdat_end_pfn(pgdat); /* pgdat_end_pfn namespace clash */ + unsigned long pgdat_end_pfn = p; + unsigned long pfn; + struct mem_section *ms; + int nid = pgdat->node_id; + + if (pgdat_start_pfn == start_pfn) { + /* + * If the section is smallest section in the pgdat, it need + * shrink pgdat->node_start_pfn and pgdat->node_spanned_pages. + * In this case, we find second smallest valid mem_section + * for shrinking zone. + */ + pfn = find_smallest_section_pfn(nid, NULL, end_pfn, + pgdat_end_pfn); + if (pfn) { + pgdat->node_start_pfn = pfn; + pgdat->node_spanned_pages = pgdat_end_pfn - pfn; + } + } else if (pgdat_end_pfn == end_pfn) { + /* + * If the section is biggest section in the pgdat, it need + * shrink pgdat->node_spanned_pages. + * In this case, we find second biggest valid mem_section for + * shrinking zone. + */ + pfn = find_biggest_section_pfn(nid, NULL, pgdat_start_pfn, + start_pfn); + if (pfn) + pgdat->node_spanned_pages = pfn - pgdat_start_pfn + 1; + } + + /* + * If the section is not biggest or smallest mem_section in the pgdat, + * it only creates a hole in the pgdat. So in this case, we need not + * change the pgdat. + * But perhaps, the pgdat has only hole data. Thus it check the pgdat + * has only hole or not. + */ + pfn = pgdat_start_pfn; + for (; pfn < pgdat_end_pfn; pfn += PAGES_PER_SECTION) { + ms = __pfn_to_section(pfn); + + if (unlikely(!valid_section(ms))) + continue; + + if (pfn_to_nid(pfn) != nid) + 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 */ + return; + } + + /* The pgdat has no valid section */ + pgdat->node_start_pfn = 0; + pgdat->node_spanned_pages = 0; +} + +static void __remove_zone(struct zone *zone, unsigned long start_pfn) +{ + struct pglist_data *pgdat = zone->zone_pgdat; + int nr_pages = PAGES_PER_SECTION; + int zone_type; + unsigned long flags; + + zone_type = zone - pgdat->node_zones; + + pgdat_resize_lock(zone->zone_pgdat, &flags); + shrink_zone_span(zone, start_pfn, start_pfn + nr_pages); + shrink_pgdat_span(pgdat, start_pfn, start_pfn + nr_pages); + pgdat_resize_unlock(zone->zone_pgdat, &flags); +} + +static int __remove_section(struct zone *zone, struct mem_section *ms) +{ + unsigned long start_pfn; + int scn_nr; + int ret = -EINVAL; + + if (!valid_section(ms)) + return ret; + + ret = unregister_memory_section(ms); + if (ret) + return ret; + + scn_nr = __section_nr(ms); + start_pfn = section_nr_to_pfn(scn_nr); + __remove_zone(zone, start_pfn); + + sparse_remove_one_section(zone, ms); + return 0; +} + +/** + * __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; + int sections_to_remove; + resource_size_t start, size; + int ret = 0; + + /* + * We can only remove entire sections + */ + BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK); + BUG_ON(nr_pages % PAGES_PER_SECTION); + + start = phys_start_pfn << PAGE_SHIFT; + size = nr_pages * PAGE_SIZE; + 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); + } + + 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); +#endif /* CONFIG_MEMORY_HOTREMOVE */ + +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++; + } + *(unsigned long *)arg = onlined_pages; + return 0; +} + +#ifdef CONFIG_MOVABLE_NODE +/* + * When CONFIG_MOVABLE_NODE, we permit onlining of a node which doesn't have + * normal memory. + */ +static bool can_online_high_movable(struct zone *zone) +{ + return true; +} +#else /* CONFIG_MOVABLE_NODE */ +/* ensure every online node has NORMAL memory */ +static bool can_online_high_movable(struct zone *zone) +{ + return node_state(zone_to_nid(zone), N_NORMAL_MEMORY); +} +#endif /* CONFIG_MOVABLE_NODE */ + +/* 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); +} + + +/* Must be protected by mem_hotplug_begin() */ +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; + + /* + * This doesn't need a lock to do pfn_to_page(). + * The section can't be removed here because of the + * memory_block->state_mutex. + */ + zone = page_zone(pfn_to_page(pfn)); + + if ((zone_idx(zone) > ZONE_NORMAL || + online_type == MMOP_ONLINE_MOVABLE) && + !can_online_high_movable(zone)) + return -EINVAL; + + if (online_type == MMOP_ONLINE_KERNEL && + zone_idx(zone) == ZONE_MOVABLE) { + if (move_pfn_range_left(zone - 1, zone, pfn, pfn + nr_pages)) + return -EINVAL; + } + if (online_type == MMOP_ONLINE_MOVABLE && + zone_idx(zone) == ZONE_MOVABLE - 1) { + if (move_pfn_range_right(zone, zone + 1, pfn, pfn + nr_pages)) + return -EINVAL; + } + + /* Previous code may changed the zone of the pfn range */ + zone = page_zone(pfn_to_page(pfn)); + + arg.start_pfn = pfn; + arg.nr_pages = nr_pages; + node_states_check_changes_online(nr_pages, zone, &arg); + + nid = pfn_to_nid(pfn); + + ret = memory_notify(MEM_GOING_ONLINE, &arg); + ret = notifier_to_errno(ret); + if (ret) { + memory_notify(MEM_CANCEL_ONLINE, &arg); + return ret; + } + /* + * 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. + */ + mutex_lock(&zonelists_mutex); + if (!populated_zone(zone)) { + need_zonelists_rebuild = 1; + build_all_zonelists(NULL, zone); + } + + ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages, + online_pages_range); + if (ret) { + if (need_zonelists_rebuild) + zone_pcp_reset(zone); + mutex_unlock(&zonelists_mutex); + printk(KERN_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); + return ret; + } + + 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(zone_to_nid(zone), &arg); + if (need_zonelists_rebuild) + build_all_zonelists(NULL, NULL); + else + zone_pcp_update(zone); + } + + mutex_unlock(&zonelists_mutex); + + init_per_zone_wmark_min(); + + if (onlined_pages) + kswapd_run(zone_to_nid(zone)); + + vm_total_pages = nr_free_pagecache_pages(); + + writeback_set_ratelimit(); + + if (onlined_pages) + memory_notify(MEM_ONLINE, &arg); + return 0; +} +#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 zones_size[MAX_NR_ZONES] = {0}; + unsigned long zholes_size[MAX_NR_ZONES] = {0}; + 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 and classzone_idx to 0 before reuse */ + pgdat->nr_zones = 0; + pgdat->classzone_idx = 0; + } + + /* 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, zones_size, start_pfn, zholes_size); + + /* + * The node we allocated has no zone fallback lists. For avoiding + * to access not-initialized zonelist, build here. + */ + mutex_lock(&zonelists_mutex); + build_all_zonelists(pgdat, NULL); + mutex_unlock(&zonelists_mutex); + + /* + * zone->managed_pages is set to an approximate value in + * free_area_init_core(), which will cause + * /sys/device/system/node/nodeX/meminfo has wrong data. + * So reset it to 0 before any memory is onlined. + */ + reset_node_managed_pages(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_present_pages(pgdat); + + return pgdat; +} + +static void rollback_node_hotadd(int nid, pg_data_t *pgdat) +{ + arch_refresh_nodedata(nid, NULL); + arch_free_nodedata(pgdat); + return; +} + + +/** + * try_online_node - online a node if offlined + * + * called by cpu_up() to online a node without onlined memory. + */ +int try_online_node(int nid) +{ + pg_data_t *pgdat; + int ret; + + if (node_online(nid)) + return 0; + + mem_hotplug_begin(); + pgdat = hotadd_new_pgdat(nid, 0); + if (!pgdat) { + pr_err("Cannot online node %d due to NULL pgdat\n", nid); + ret = -ENOMEM; + goto out; + } + node_set_online(nid); + ret = register_one_node(nid); + BUG_ON(ret); + + if (pgdat->node_zonelists->_zonerefs->zone == NULL) { + mutex_lock(&zonelists_mutex); + build_all_zonelists(NULL, NULL); + mutex_unlock(&zonelists_mutex); + } + +out: + mem_hotplug_done(); + return ret; +} + +static int check_hotplug_memory_range(u64 start, u64 size) +{ + u64 start_pfn = PFN_DOWN(start); + u64 nr_pages = size >> PAGE_SHIFT; + + /* Memory range must be aligned with section */ + if ((start_pfn & ~PAGE_SECTION_MASK) || + (nr_pages % PAGES_PER_SECTION) || (!nr_pages)) { + pr_err("Section-unaligned hotplug range: start 0x%llx, size 0x%llx\n", + (unsigned long long)start, + (unsigned long long)size); + return -EINVAL; + } + + return 0; +} + +/* + * If movable zone has already been setup, newly added memory should be check. + * If its address is higher than movable zone, it should be added as movable. + * Without this check, movable zone may overlap with other zone. + */ +static int should_add_memory_movable(int nid, u64 start, u64 size) +{ + unsigned long start_pfn = start >> PAGE_SHIFT; + pg_data_t *pgdat = NODE_DATA(nid); + struct zone *movable_zone = pgdat->node_zones + ZONE_MOVABLE; + + if (zone_is_empty(movable_zone)) + return 0; + + if (movable_zone->zone_start_pfn <= start_pfn) + return 1; + + return 0; +} + +int zone_for_memory(int nid, u64 start, u64 size, int zone_default) +{ + if (should_add_memory_movable(nid, start, size)) + return ZONE_MOVABLE; + + return zone_default; +} + +/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ +int __ref add_memory(int nid, u64 start, u64 size) +{ + pg_data_t *pgdat = NULL; + bool new_pgdat; + bool new_node; + struct resource *res; + int ret; + + ret = check_hotplug_memory_range(start, size); + if (ret) + return ret; + + res = register_memory_resource(start, size); + ret = -EEXIST; + if (!res) + return ret; + + { /* Stupid hack to suppress address-never-null warning */ + void *p = NODE_DATA(nid); + new_pgdat = !p; + } + + mem_hotplug_begin(); + + new_node = !node_online(nid); + if (new_node) { + pgdat = hotadd_new_pgdat(nid, start); + ret = -ENOMEM; + if (!pgdat) + 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); + + if (new_node) { + 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); + } + + /* create new memmap entry */ + firmware_map_add_hotplug(start, start + size, "System RAM"); + + goto out; + +error: + /* rollback pgdat allocation and others */ + if (new_pgdat) + rollback_node_hotadd(nid, pgdat); + release_memory_resource(res); + +out: + mem_hotplug_done(); + return ret; +} +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 start of the next active pageblock after a given page */ +static struct page *next_active_pageblock(struct page *page) +{ + /* Ensure the starting page is pageblock-aligned */ + BUG_ON(page_to_pfn(page) & (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 page + (1 << order); + } + + return page + pageblock_nr_pages; +} + +/* Checks if this range of memory is likely to be hot-removable. */ +int is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages) +{ + struct page *page = pfn_to_page(start_pfn); + struct page *end_page = page + nr_pages; + + /* Check the starting page of each pageblock within the range */ + for (; page < end_page; page = next_active_pageblock(page)) { + if (!is_pageblock_removable_nolock(page)) + return 0; + cond_resched(); + } + + /* All pageblocks in the memory block are likely to be hot-removable */ + return 1; +} + +/* + * Confirm all pages in a range [start, end) is belongs to the same zone. + */ +int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn) +{ + unsigned long pfn; + struct zone *zone = NULL; + struct page *page; + int i; + for (pfn = start_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) + continue; + page = pfn_to_page(pfn + i); + if (zone && page_zone(page) != zone) + return 0; + zone = page_zone(page); + } + return 1; +} + +/* + * Scan pfn range [start,end) to find movable/migratable pages (LRU 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; + struct page *page; + for (pfn = start; pfn < end; pfn++) { + if (pfn_valid(pfn)) { + page = pfn_to_page(pfn); + if (PageLRU(page)) + return pfn; + if (PageHuge(page)) { + if (page_huge_active(page)) + return pfn; + else + pfn = round_up(pfn + 1, + 1 << compound_order(page)) - 1; + } + } + } + return 0; +} + +#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; + } + + if (!get_page_unless_zero(page)) + continue; + /* + * We can skip free pages. And we can only deal with pages on + * LRU. + */ + ret = isolate_lru_page(page); + if (!ret) { /* Success */ + put_page(page); + list_add_tail(&page->lru, &source); + move_pages--; + inc_zone_page_state(page, NR_ISOLATED_ANON + + page_is_file_cache(page)); + + } else { +#ifdef CONFIG_DEBUG_VM + printk(KERN_ALERT "removing pfn %lx from LRU failed\n", + pfn); + dump_page(page, "failed to remove from LRU"); +#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; + } + + /* + * alloc_migrate_target should be improooooved!! + * migrate_pages returns # of failed pages. + */ + ret = migrate_pages(&source, alloc_migrate_target, 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; +} + +#ifdef CONFIG_MOVABLE_NODE +/* + * When CONFIG_MOVABLE_NODE, we permit offlining of a node which doesn't have + * normal memory. + */ +static bool can_offline_normal(struct zone *zone, unsigned long nr_pages) +{ + return true; +} +#else /* CONFIG_MOVABLE_NODE */ +/* ensure the node has NORMAL memory if it is still online */ +static bool can_offline_normal(struct zone *zone, unsigned long nr_pages) +{ + struct pglist_data *pgdat = zone->zone_pgdat; + unsigned long present_pages = 0; + enum zone_type zt; + + for (zt = 0; zt <= ZONE_NORMAL; zt++) + present_pages += pgdat->node_zones[zt].present_pages; + + if (present_pages > nr_pages) + return true; + + present_pages = 0; + for (; zt <= ZONE_MOVABLE; zt++) + present_pages += pgdat->node_zones[zt].present_pages; + + /* + * we can't offline the last normal memory until all + * higher memory is offlined. + */ + return present_pages == 0; +} +#endif /* CONFIG_MOVABLE_NODE */ + +static int __init cmdline_parse_movable_node(char *p) +{ +#ifdef CONFIG_MOVABLE_NODE + /* + * Memory used by the kernel cannot be hot-removed because Linux + * cannot migrate the kernel pages. When memory hotplug is + * enabled, we should prevent memblock from allocating memory + * for the kernel. + * + * ACPI SRAT records all hotpluggable memory ranges. But before + * SRAT is parsed, we don't know about it. + * + * The kernel image is loaded into memory at very early time. We + * cannot prevent this anyway. So on NUMA system, we set any + * node the kernel resides in as un-hotpluggable. + * + * Since on modern servers, one node could have double-digit + * gigabytes memory, we can assume the memory around the kernel + * image is also un-hotpluggable. So before SRAT is parsed, just + * allocate memory near the kernel image to try the best to keep + * the kernel away from hotpluggable memory. + */ + memblock_set_bottom_up(true); + movable_node_enabled = true; +#else + pr_warn("movable_node option not supported\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 timeout) +{ + unsigned long pfn, nr_pages, expire; + long offlined_pages; + int ret, drain, retry_max, node; + unsigned long flags; + 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; + /* This makes hotplug much easier...and readable. + we assume this for now. .*/ + if (!test_pages_in_a_zone(start_pfn, end_pfn)) + return -EINVAL; + + zone = page_zone(pfn_to_page(start_pfn)); + node = zone_to_nid(zone); + nr_pages = end_pfn - start_pfn; + + if (zone_idx(zone) <= ZONE_NORMAL && !can_offline_normal(zone, nr_pages)) + return -EINVAL; + + /* set above range as isolated */ + ret = start_isolate_page_range(start_pfn, end_pfn, + MIGRATE_MOVABLE, true); + if (ret) + 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; + expire = jiffies + timeout; + drain = 0; + retry_max = 5; +repeat: + /* start memory hot removal */ + ret = -EAGAIN; + if (time_after(jiffies, expire)) + goto failed_removal; + ret = -EINTR; + if (signal_pending(current)) + goto failed_removal; + ret = 0; + if (drain) { + lru_add_drain_all(); + cond_resched(); + 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); + if (!ret) { + drain = 1; + goto repeat; + } else { + if (ret < 0) + if (--retry_max == 0) + goto failed_removal; + yield(); + drain = 1; + goto repeat; + } + } + /* drain all zone's lru pagevec, this is asynchronous... */ + lru_add_drain_all(); + yield(); + /* drain pcp pages, this is synchronous. */ + drain_all_pages(zone); + /* + * dissolve free hugepages in the memory block before doing offlining + * actually in order to make hugetlbfs's object counting consistent. + */ + dissolve_free_huge_pages(start_pfn, end_pfn); + /* check again */ + offlined_pages = check_pages_isolated(start_pfn, end_pfn); + if (offlined_pages < 0) { + ret = -EBUSY; + goto failed_removal; + } + printk(KERN_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); + mutex_lock(&zonelists_mutex); + build_all_zonelists(NULL, NULL); + mutex_unlock(&zonelists_mutex); + } else + zone_pcp_update(zone); + + node_states_clear_node(node, &arg); + if (arg.status_change_nid >= 0) + kswapd_stop(node); + + vm_total_pages = nr_free_pagecache_pages(); + writeback_set_ratelimit(); + + memory_notify(MEM_OFFLINE, &arg); + return 0; + +failed_removal: + printk(KERN_INFO "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); + return ret; +} + +/* Must be protected by mem_hotplug_begin() */ +int offline_pages(unsigned long start_pfn, unsigned long nr_pages) +{ + return __offline_pages(start_pfn, start_pfn + nr_pages, 120 * HZ); +} +#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; +} + +/** + * try_offline_node + * + * 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); + unsigned long start_pfn = pgdat->node_start_pfn; + unsigned long end_pfn = start_pfn + pgdat->node_spanned_pages; + unsigned long pfn; + int i; + + for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { + unsigned long section_nr = pfn_to_section_nr(pfn); + + if (!present_section_nr(section_nr)) + continue; + + if (pfn_to_nid(pfn) != nid) + continue; + + /* + * some memory sections of this node are not removed, and we + * can't offline node now. + */ + 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); + + /* free waittable in each zone */ + for (i = 0; i < MAX_NR_ZONES; i++) { + struct zone *zone = pgdat->node_zones + i; + + /* + * wait_table may be allocated from boot memory, + * here only free if it's allocated by vmalloc. + */ + if (is_vmalloc_addr(zone->wait_table)) { + vfree(zone->wait_table); + zone->wait_table = NULL; + } + } +} +EXPORT_SYMBOL(try_offline_node); + +/** + * remove_memory + * + * 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)); + + mem_hotplug_begin(); + + /* + * 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"); + + arch_remove_memory(start, size); + + try_offline_node(nid); + + mem_hotplug_done(); +} +EXPORT_SYMBOL_GPL(remove_memory); +#endif /* CONFIG_MEMORY_HOTREMOVE */ |