| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * 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/compaction.h> |
| #include <linux/rmap.h> |
| |
| #include <asm/tlbflush.h> |
| |
| #include "internal.h" |
| #include "shuffle.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 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 |
| int memhp_default_online_type = MMOP_OFFLINE; |
| #else |
| int memhp_default_online_type = MMOP_ONLINE; |
| #endif |
| |
| static int __init setup_memhp_default_state(char *str) |
| { |
| const int online_type = memhp_online_type_from_str(str); |
| |
| if (online_type >= 0) |
| memhp_default_online_type = online_type; |
| |
| 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(); |
| } |
| |
| u64 max_mem_size = U64_MAX; |
| |
| /* add this memory to iomem resource */ |
| static struct resource *register_memory_resource(u64 start, u64 size, |
| const char *resource_name) |
| { |
| struct resource *res; |
| unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; |
| |
| if (strcmp(resource_name, "System RAM")) |
| flags |= IORESOURCE_MEM_DRIVER_MANAGED; |
| |
| /* |
| * Make sure value parsed from 'mem=' only restricts memory adding |
| * while booting, so that memory hotplug won't be impacted. Please |
| * refer to document of 'mem=' in kernel-parameters.txt for more |
| * details. |
| */ |
| if (start + size > max_mem_size && system_state < SYSTEM_RUNNING) |
| return ERR_PTR(-E2BIG); |
| |
| /* |
| * Request ownership of the new memory range. This might be |
| * a child of an existing resource that was present but |
| * not marked as busy. |
| */ |
| res = __request_region(&iomem_resource, start, size, |
| resource_name, flags); |
| |
| if (!res) { |
| pr_debug("Unable to reserve System RAM region: %016llx->%016llx\n", |
| start, start + size); |
| return ERR_PTR(-EEXIST); |
| } |
| return res; |
| } |
| |
| static void release_memory_resource(struct resource *res) |
| { |
| if (!res) |
| return; |
| release_resource(res); |
| kfree(res); |
| } |
| |
| #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 mapsize, section_nr, i; |
| struct mem_section *ms; |
| struct page *page, *memmap; |
| struct mem_section_usage *usage; |
| |
| 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); |
| |
| usage = ms->usage; |
| page = virt_to_page(usage); |
| |
| mapsize = PAGE_ALIGN(mem_section_usage_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 mapsize, section_nr, i; |
| struct mem_section *ms; |
| struct page *page, *memmap; |
| struct mem_section_usage *usage; |
| |
| 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); |
| |
| usage = ms->usage; |
| page = virt_to_page(usage); |
| |
| mapsize = PAGE_ALIGN(mem_section_usage_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 check_pfn_span(unsigned long pfn, unsigned long nr_pages, |
| const char *reason) |
| { |
| /* |
| * Disallow all operations smaller than a sub-section and only |
| * allow operations smaller than a section for |
| * SPARSEMEM_VMEMMAP. Note that check_hotplug_memory_range() |
| * enforces a larger memory_block_size_bytes() granularity for |
| * memory that will be marked online, so this check should only |
| * fire for direct arch_{add,remove}_memory() users outside of |
| * add_memory_resource(). |
| */ |
| unsigned long min_align; |
| |
| if (IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP)) |
| min_align = PAGES_PER_SUBSECTION; |
| else |
| min_align = PAGES_PER_SECTION; |
| if (!IS_ALIGNED(pfn, min_align) |
| || !IS_ALIGNED(nr_pages, min_align)) { |
| WARN(1, "Misaligned __%s_pages start: %#lx end: #%lx\n", |
| reason, pfn, pfn + nr_pages - 1); |
| return -EINVAL; |
| } |
| return 0; |
| } |
| |
| static int check_hotplug_memory_addressable(unsigned long pfn, |
| unsigned long nr_pages) |
| { |
| const u64 max_addr = PFN_PHYS(pfn + nr_pages) - 1; |
| |
| if (max_addr >> MAX_PHYSMEM_BITS) { |
| const u64 max_allowed = (1ull << (MAX_PHYSMEM_BITS + 1)) - 1; |
| WARN(1, |
| "Hotplugged memory exceeds maximum addressable address, range=%#llx-%#llx, maximum=%#llx\n", |
| (u64)PFN_PHYS(pfn), max_addr, max_allowed); |
| return -E2BIG; |
| } |
| |
| return 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 pfn, unsigned long nr_pages, |
| struct mhp_params *params) |
| { |
| const unsigned long end_pfn = pfn + nr_pages; |
| unsigned long cur_nr_pages; |
| int err; |
| struct vmem_altmap *altmap = params->altmap; |
| |
| if (WARN_ON_ONCE(!params->pgprot.pgprot)) |
| return -EINVAL; |
| |
| err = check_hotplug_memory_addressable(pfn, nr_pages); |
| if (err) |
| return err; |
| |
| if (altmap) { |
| /* |
| * Validate altmap is within bounds of the total request |
| */ |
| if (altmap->base_pfn != pfn |
| || vmem_altmap_offset(altmap) > nr_pages) { |
| pr_warn_once("memory add fail, invalid altmap\n"); |
| return -EINVAL; |
| } |
| altmap->alloc = 0; |
| } |
| |
| err = check_pfn_span(pfn, nr_pages, "add"); |
| if (err) |
| return err; |
| |
| for (; pfn < end_pfn; pfn += cur_nr_pages) { |
| /* Select all remaining pages up to the next section boundary */ |
| cur_nr_pages = min(end_pfn - pfn, |
| SECTION_ALIGN_UP(pfn + 1) - pfn); |
| err = sparse_add_section(nid, pfn, cur_nr_pages, altmap); |
| if (err) |
| break; |
| cond_resched(); |
| } |
| vmemmap_populate_print_last(); |
| 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_SUBSECTION) { |
| if (unlikely(!pfn_to_online_page(start_pfn))) |
| continue; |
| |
| if (unlikely(pfn_to_nid(start_pfn) != nid)) |
| continue; |
| |
| if (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_SUBSECTION) { |
| if (unlikely(!pfn_to_online_page(pfn))) |
| continue; |
| |
| if (unlikely(pfn_to_nid(pfn) != nid)) |
| continue; |
| |
| if (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 pfn; |
| int nid = zone_to_nid(zone); |
| |
| zone_span_writelock(zone); |
| if (zone->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(zone)); |
| if (pfn) { |
| zone->spanned_pages = zone_end_pfn(zone) - pfn; |
| zone->zone_start_pfn = pfn; |
| } else { |
| zone->zone_start_pfn = 0; |
| zone->spanned_pages = 0; |
| } |
| } else if (zone_end_pfn(zone) == 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->zone_start_pfn, |
| start_pfn); |
| if (pfn) |
| zone->spanned_pages = pfn - zone->zone_start_pfn + 1; |
| else { |
| 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; |
| |
| /* Poison struct pages because they are now uninitialized again. */ |
| page_init_poison(pfn_to_page(start_pfn), sizeof(struct page) * nr_pages); |
| |
| #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(unsigned long pfn, unsigned long nr_pages, |
| unsigned long map_offset, |
| struct vmem_altmap *altmap) |
| { |
| struct mem_section *ms = __pfn_to_section(pfn); |
| |
| if (WARN_ON_ONCE(!valid_section(ms))) |
| return; |
| |
| sparse_remove_section(ms, pfn, nr_pages, map_offset, altmap); |
| } |
| |
| /** |
| * __remove_pages() - remove sections of pages |
| * @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 pfn, unsigned long nr_pages, |
| struct vmem_altmap *altmap) |
| { |
| const unsigned long end_pfn = pfn + nr_pages; |
| unsigned long cur_nr_pages; |
| unsigned long map_offset = 0; |
| |
| map_offset = vmem_altmap_offset(altmap); |
| |
| if (check_pfn_span(pfn, nr_pages, "remove")) |
| return; |
| |
| for (; pfn < end_pfn; pfn += cur_nr_pages) { |
| cond_resched(); |
| /* Select all remaining pages up to the next section boundary */ |
| cur_nr_pages = min(end_pfn - pfn, |
| SECTION_ALIGN_UP(pfn + 1) - pfn); |
| __remove_section(pfn, cur_nr_pages, 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 generic_online_page(struct page *page, unsigned int order) |
| { |
| /* |
| * Freeing the page with debug_pagealloc enabled will try to unmap it, |
| * so we should map it first. This is better than introducing a special |
| * case in page freeing fast path. |
| */ |
| if (debug_pagealloc_enabled_static()) |
| kernel_map_pages(page, 1 << order, 1); |
| __free_pages_core(page, order); |
| totalram_pages_add(1UL << order); |
| #ifdef CONFIG_HIGHMEM |
| if (PageHighMem(page)) |
| totalhigh_pages_add(1UL << order); |
| #endif |
| } |
| EXPORT_SYMBOL_GPL(generic_online_page); |
| |
| static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages, |
| void *arg) |
| { |
| const unsigned long end_pfn = start_pfn + nr_pages; |
| unsigned long pfn; |
| int order; |
| |
| /* |
| * Online the pages. The callback might decide to keep some pages |
| * PG_reserved (to add them to the buddy later), but we still account |
| * them as being online/belonging to this zone ("present"). |
| */ |
| for (pfn = start_pfn; pfn < end_pfn; pfn += 1ul << order) { |
| order = min(MAX_ORDER - 1, get_order(PFN_PHYS(end_pfn - pfn))); |
| /* __free_pages_core() wants pfns to be aligned to the order */ |
| if (WARN_ON_ONCE(!IS_ALIGNED(pfn, 1ul << order))) |
| order = 0; |
| (*online_page_callback)(pfn_to_page(pfn), order); |
| } |
| |
| /* mark all involved sections as online */ |
| online_mem_sections(start_pfn, end_pfn); |
| |
| *(unsigned long *)arg += nr_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); |
| |
| arg->status_change_nid = NUMA_NO_NODE; |
| arg->status_change_nid_normal = NUMA_NO_NODE; |
| arg->status_change_nid_high = NUMA_NO_NODE; |
| |
| if (!node_state(nid, N_MEMORY)) |
| arg->status_change_nid = nid; |
| if (zone_idx(zone) <= ZONE_NORMAL && !node_state(nid, N_NORMAL_MEMORY)) |
| arg->status_change_nid_normal = nid; |
| #ifdef CONFIG_HIGHMEM |
| if (zone_idx(zone) <= ZONE_HIGHMEM && !node_state(nid, N_HIGH_MEMORY)) |
| arg->status_change_nid_high = nid; |
| #endif |
| } |
| |
| 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); |
| |
| if (arg->status_change_nid >= 0) |
| 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; |
| |
| } |
| /* |
| * Associate the pfn range with the given zone, initializing the memmaps |
| * and resizing the pgdat/zone data to span the added pages. After this |
| * call, all affected pages are PG_reserved. |
| */ |
| 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; |
| |
| 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); |
| if (zone_is_empty(zone)) |
| init_currently_empty_zone(zone, start_pfn, nr_pages); |
| 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, |
| MEMMAP_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 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); |
| } |
| |
| int __ref online_pages(unsigned long pfn, unsigned long nr_pages, |
| int online_type, int nid) |
| { |
| unsigned long flags; |
| unsigned long onlined_pages = 0; |
| struct zone *zone; |
| int need_zonelists_rebuild = 0; |
| int ret; |
| struct memory_notify arg; |
| |
| mem_hotplug_begin(); |
| |
| /* associate pfn range with the zone */ |
| zone = zone_for_pfn_range(online_type, nid, pfn, nr_pages); |
| move_pfn_range_to_zone(zone, pfn, nr_pages, NULL); |
| |
| 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) { |
| /* not a single memory resource was applicable */ |
| 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); |
| |
| shuffle_zone(zone); |
| |
| node_states_set_node(nid, &arg); |
| if (need_zonelists_rebuild) |
| build_all_zonelists(NULL); |
| else |
| zone_pcp_update(zone); |
| |
| init_per_zone_wmark_min(); |
| |
| kswapd_run(nid); |
| kcompactd_run(nid); |
| |
| vm_total_pages = nr_free_pagecache_pages(); |
| |
| writeback_set_ratelimit(); |
| |
| 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) |
| { |
| struct pglist_data *pgdat; |
| |
| pgdat = NODE_DATA(nid); |
| if (!pgdat) { |
| pgdat = arch_alloc_nodedata(nid); |
| if (!pgdat) |
| return NULL; |
| |
| pgdat->per_cpu_nodestats = |
| alloc_percpu(struct per_cpu_nodestat); |
| arch_refresh_nodedata(nid, pgdat); |
| } else { |
| int cpu; |
| /* |
| * Reset the nr_zones, order and highest_zoneidx before reuse. |
| * Note that kswapd will init kswapd_highest_zoneidx properly |
| * when it starts in the near future. |
| */ |
| pgdat->nr_zones = 0; |
| pgdat->kswapd_order = 0; |
| pgdat->kswapd_highest_zoneidx = 0; |
| for_each_online_cpu(cpu) { |
| struct per_cpu_nodestat *p; |
| |
| p = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu); |
| memset(p, 0, sizeof(*p)); |
| } |
| } |
| |
| /* we can use NODE_DATA(nid) from here */ |
| pgdat->node_id = nid; |
| pgdat->node_start_pfn = 0; |
| |
| /* init node's zones as empty zones, we don't have any present pages.*/ |
| free_area_init_core_hotplug(nid); |
| |
| /* |
| * 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); |
| } |
| |
| |
| /** |
| * try_online_node - online a node if offlined |
| * @nid: the node ID |
| * @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, bool set_node_online) |
| { |
| pg_data_t *pgdat; |
| int ret = 1; |
| |
| if (node_online(nid)) |
| return 0; |
| |
| pgdat = hotadd_new_pgdat(nid); |
| 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, true); |
| mem_hotplug_done(); |
| return ret; |
| } |
| |
| static int check_hotplug_memory_range(u64 start, u64 size) |
| { |
| /* memory range must be block size aligned */ |
| if (!size || !IS_ALIGNED(start, memory_block_size_bytes()) || |
| !IS_ALIGNED(size, memory_block_size_bytes())) { |
| pr_err("Block size [%#lx] unaligned hotplug range: start %#llx, size %#llx", |
| memory_block_size_bytes(), start, size); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static int online_memory_block(struct memory_block *mem, void *arg) |
| { |
| mem->online_type = memhp_default_online_type; |
| 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) |
| { |
| struct mhp_params params = { .pgprot = PAGE_KERNEL }; |
| 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; |
| |
| if (!node_possible(nid)) { |
| WARN(1, "node %d was absent from the node_possible_map\n", nid); |
| return -EINVAL; |
| } |
| |
| mem_hotplug_begin(); |
| |
| if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) |
| memblock_add_node(start, size, nid); |
| |
| ret = __try_online_node(nid, false); |
| if (ret < 0) |
| goto error; |
| new_node = ret; |
| |
| /* call arch's memory hotadd */ |
| ret = arch_add_memory(nid, start, size, ¶ms); |
| 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)); |
| BUG_ON(ret); |
| |
| /* create new memmap entry */ |
| if (!strcmp(res->name, "System RAM")) |
| 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 (memhp_default_online_type != MMOP_OFFLINE) |
| walk_memory_blocks(start, size, NULL, online_memory_block); |
| |
| return ret; |
| error: |
| /* rollback pgdat allocation and others */ |
| if (new_node) |
| rollback_node_hotadd(nid); |
| if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) |
| 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, "System RAM"); |
| if (IS_ERR(res)) |
| return PTR_ERR(res); |
| |
| ret = add_memory_resource(nid, res); |
| 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); |
| |
| /* |
| * Add special, driver-managed memory to the system as system RAM. Such |
| * memory is not exposed via the raw firmware-provided memmap as system |
| * RAM, instead, it is detected and added by a driver - during cold boot, |
| * after a reboot, and after kexec. |
| * |
| * Reasons why this memory should not be used for the initial memmap of a |
| * kexec kernel or for placing kexec images: |
| * - The booting kernel is in charge of determining how this memory will be |
| * used (e.g., use persistent memory as system RAM) |
| * - Coordination with a hypervisor is required before this memory |
| * can be used (e.g., inaccessible parts). |
| * |
| * For this memory, no entries in /sys/firmware/memmap ("raw firmware-provided |
| * memory map") are created. Also, the created memory resource is flagged |
| * with IORESOURCE_MEM_DRIVER_MANAGED, so in-kernel users can special-case |
| * this memory as well (esp., not place kexec images onto it). |
| * |
| * The resource_name (visible via /proc/iomem) has to have the format |
| * "System RAM ($DRIVER)". |
| */ |
| int add_memory_driver_managed(int nid, u64 start, u64 size, |
| const char *resource_name) |
| { |
| struct resource *res; |
| int rc; |
| |
| if (!resource_name || |
| strstr(resource_name, "System RAM (") != resource_name || |
| resource_name[strlen(resource_name) - 1] != ')') |
| return -EINVAL; |
| |
| lock_device_hotplug(); |
| |
| res = register_memory_resource(start, size, resource_name); |
| if (IS_ERR(res)) { |
| rc = PTR_ERR(res); |
| goto out_unlock; |
| } |
| |
| rc = add_memory_resource(nid, res); |
| if (rc < 0) |
| release_memory_resource(res); |
| |
| out_unlock: |
| unlock_device_hotplug(); |
| return rc; |
| } |
| EXPORT_SYMBOL_GPL(add_memory_driver_managed); |
| |
| #ifdef CONFIG_MEMORY_HOTREMOVE |
| /* |
| * Confirm all pages in a range [start, end) belong to the same zone (skipping |
| * memory holes). When true, return the zone. |
| */ |
| struct zone *test_pages_in_a_zone(unsigned long start_pfn, |
| unsigned long end_pfn) |
| { |
| unsigned long pfn, sec_end_pfn; |
| 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 NULL; |
| page = pfn_to_page(pfn + i); |
| if (zone && page_zone(page) != zone) |
| return NULL; |
| zone = page_zone(page); |
| } |
| } |
| |
| return zone; |
| } |
| |
| /* |
| * 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 (page_huge_active(head)) |
| return pfn; |
| skip = compound_nr(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); |
| } |
| |
| static int |
| do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) |
| { |
| unsigned long pfn; |
| struct page *page; |
| int ret = 0; |
| LIST_HEAD(source); |
| |
| for (pfn = start_pfn; pfn < end_pfn; 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) + compound_nr(head) - 1; |
| isolate_huge_page(head, &source); |
| 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 */ |
| list_add_tail(&page->lru, &source); |
| if (!__PageMovable(page)) |
| inc_node_page_state(page, NR_ISOLATED_ANON + |
| page_is_file_lru(page)); |
| |
| } else { |
| pr_warn("failed to isolate pfn %lx\n", pfn); |
| dump_page(page, "isolation failed"); |
| } |
| put_page(page); |
| } |
| if (!list_empty(&source)) { |
| /* 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) { |
| list_for_each_entry(page, &source, lru) { |
| pr_warn("migrating pfn %lx failed ret:%d ", |
| page_to_pfn(page), ret); |
| dump_page(page, "migration failure"); |
| } |
| putback_movable_pages(&source); |
| } |
| } |
| |
| return ret; |
| } |
| |
| /* Mark all sections offline and remove all free pages from the buddy. */ |
| static int |
| offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages, |
| void *data) |
| { |
| unsigned long *offlined_pages = (unsigned long *)data; |
| |
| *offlined_pages += __offline_isolated_pages(start, start + nr_pages); |
| return 0; |
| } |
| |
| /* |
| * Check all pages in range, recorded as memory resource, are isolated. |
| */ |
| static int |
| check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages, |
| void *data) |
| { |
| return test_pages_isolated(start_pfn, start_pfn + nr_pages, |
| MEMORY_OFFLINE); |
| } |
| |
| static int __init cmdline_parse_movable_node(char *p) |
| { |
| movable_node_enabled = true; |
| 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; |
| |
| arg->status_change_nid = NUMA_NO_NODE; |
| arg->status_change_nid_normal = NUMA_NO_NODE; |
| arg->status_change_nid_high = NUMA_NO_NODE; |
| |
| /* |
| * Check whether node_states[N_NORMAL_MEMORY] will be changed. |
| * If the memory to be offline is within the range |
| * [0..ZONE_NORMAL], and it is the last present memory there, |
| * the zones in that range will become empty after the offlining, |
| * thus we can determine that we need to clear the node from |
| * node_states[N_NORMAL_MEMORY]. |
| */ |
| for (zt = 0; zt <= ZONE_NORMAL; zt++) |
| present_pages += pgdat->node_zones[zt].present_pages; |
| if (zone_idx(zone) <= ZONE_NORMAL && nr_pages >= present_pages) |
| arg->status_change_nid_normal = zone_to_nid(zone); |
| |
| #ifdef CONFIG_HIGHMEM |
| /* |
| * node_states[N_HIGH_MEMORY] contains nodes which |
| * have normal memory or high memory. |
| * Here we add the present_pages belonging to ZONE_HIGHMEM. |
| * If the zone is within the range of [0..ZONE_HIGHMEM), and |
| * we determine that the zones in that range become empty, |
| * we need to clear the node for N_HIGH_MEMORY. |
| */ |
| present_pages += pgdat->node_zones[ZONE_HIGHMEM].present_pages; |
| if (zone_idx(zone) <= ZONE_HIGHMEM && nr_pages >= present_pages) |
| arg->status_change_nid_high = zone_to_nid(zone); |
| #endif |
| |
| /* |
| * We have accounted the pages from [0..ZONE_NORMAL), and |
| * in case of CONFIG_HIGHMEM the pages from ZONE_HIGHMEM |
| * as well. |
| * Here we count the possible pages from ZONE_MOVABLE. |
| * If after having accounted all the pages, we see that the nr_pages |
| * to be offlined is over or equal to the accounted pages, |
| * we know that the node will become empty, and so, we can clear |
| * it for N_MEMORY as well. |
| */ |
| present_pages += pgdat->node_zones[ZONE_MOVABLE].present_pages; |
| |
| if (nr_pages >= present_pages) |
| arg->status_change_nid = zone_to_nid(zone); |
| } |
| |
| 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 (arg->status_change_nid_high >= 0) |
| node_clear_state(node, N_HIGH_MEMORY); |
| |
| if (arg->status_change_nid >= 0) |
| node_clear_state(node, N_MEMORY); |
| } |
| |
| static int count_system_ram_pages_cb(unsigned long start_pfn, |
| unsigned long nr_pages, void *data) |
| { |
| unsigned long *nr_system_ram_pages = data; |
| |
| *nr_system_ram_pages += nr_pages; |
| return 0; |
| } |
| |
| static int __ref __offline_pages(unsigned long start_pfn, |
| unsigned long end_pfn) |
| { |
| unsigned long pfn, nr_pages = 0; |
| unsigned long offlined_pages = 0; |
| int ret, node, nr_isolate_pageblock; |
| unsigned long flags; |
| struct zone *zone; |
| struct memory_notify arg; |
| char *reason; |
| |
| mem_hotplug_begin(); |
| |
| /* |
| * Don't allow to offline memory blocks that contain holes. |
| * Consequently, memory blocks with holes can never get onlined |
| * via the hotplug path - online_pages() - as hotplugged memory has |
| * no holes. This way, we e.g., don't have to worry about marking |
| * memory holes PG_reserved, don't need pfn_valid() checks, and can |
| * avoid using walk_system_ram_range() later. |
| */ |
| walk_system_ram_range(start_pfn, end_pfn - start_pfn, &nr_pages, |
| count_system_ram_pages_cb); |
| if (nr_pages != end_pfn - start_pfn) { |
| ret = -EINVAL; |
| reason = "memory holes"; |
| goto failed_removal; |
| } |
| |
| /* This makes hotplug much easier...and readable. |
| we assume this for now. .*/ |
| zone = test_pages_in_a_zone(start_pfn, end_pfn); |
| if (!zone) { |
| ret = -EINVAL; |
| reason = "multizone range"; |
| goto failed_removal; |
| } |
| node = zone_to_nid(zone); |
| |
| /* set above range as isolated */ |
| ret = start_isolate_page_range(start_pfn, end_pfn, |
| MIGRATE_MOVABLE, |
| MEMORY_OFFLINE | REPORT_FAILURE); |
| if (ret < 0) { |
| reason = "failure to isolate range"; |
| goto failed_removal; |
| } |
| nr_isolate_pageblock = 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) { |
| reason = "notifier failure"; |
| goto failed_removal_isolated; |
| } |
| |
| do { |
| for (pfn = start_pfn; pfn;) { |
| if (signal_pending(current)) { |
| ret = -EINTR; |
| reason = "signal backoff"; |
| goto failed_removal_isolated; |
| } |
| |
| cond_resched(); |
| lru_add_drain_all(); |
| |
| pfn = scan_movable_pages(pfn, end_pfn); |
| if (pfn) { |
| /* |
| * TODO: fatal migration failures should bail |
| * out |
| */ |
| do_migrate_range(pfn, end_pfn); |
| } |
| } |
| |
| /* |
| * 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) { |
| reason = "failure to dissolve huge pages"; |
| goto failed_removal_isolated; |
| } |
| /* check again */ |
| ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn, |
| NULL, check_pages_isolated_cb); |
| } while (ret); |
| |
| /* Ok, all of our target is isolated. |
| We cannot do rollback at this point. */ |
| walk_system_ram_range(start_pfn, end_pfn - start_pfn, |
| &offlined_pages, offline_isolated_pages_cb); |
| pr_info("Offlined Pages %ld\n", offlined_pages); |
| /* |
| * Onlining will reset pagetype flags and makes migrate type |
| * MOVABLE, so just need to decrease the number of isolated |
| * pageblocks zone counter here. |
| */ |
| spin_lock_irqsave(&zone->lock, flags); |
| zone->nr_isolate_pageblock -= nr_isolate_pageblock; |
| spin_unlock_irqrestore(&zone->lock, flags); |
| |
| /* 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_isolated: |
| undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE); |
| memory_notify(MEM_CANCEL_OFFLINE, &arg); |
| failed_removal: |
| pr_debug("memory offlining [mem %#010llx-%#010llx] failed due to %s\n", |
| (unsigned long long) start_pfn << PAGE_SHIFT, |
| ((unsigned long long) end_pfn << PAGE_SHIFT) - 1, |
| reason); |
| /* pushback to free area */ |
| 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); |
| } |
| |
| 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 = beginpa + memory_block_size_bytes() - 1; |
| pr_warn("removing memory fails, because memory [%pa-%pa] is onlined\n", |
| &beginpa, &endpa); |
| |
| return -EBUSY; |
| } |
| return 0; |
| } |
| |
| 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 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_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); |
| } |
| } |
| |
| static int __ref try_remove_memory(int nid, u64 start, u64 size) |
| { |
| int rc = 0; |
| |
| 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 return error |
| * if this is not the case. |
| */ |
| rc = walk_memory_blocks(start, size, NULL, check_memblock_offlined_cb); |
| if (rc) |
| goto done; |
| |
| /* remove memmap entry */ |
| firmware_map_remove(start, start + size, "System RAM"); |
| |
| /* |
| * 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); |
| |
| if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) { |
| memblock_free(start, size); |
| memblock_remove(start, size); |
| } |
| |
| __release_memory_resource(start, size); |
| |
| try_offline_node(nid); |
| |
| done: |
| mem_hotplug_done(); |
| return rc; |
| } |
| |
| /** |
| * 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 __remove_memory(int nid, u64 start, u64 size) |
| { |
| |
| /* |
| * trigger BUG() if some memory is not offlined prior to calling this |
| * function |
| */ |
| if (try_remove_memory(nid, start, size)) |
| BUG(); |
| } |
| |
| /* |
| * Remove memory if every memory block is offline, otherwise return -EBUSY is |
| * some memory is not offline |
| */ |
| int remove_memory(int nid, u64 start, u64 size) |
| { |
| int rc; |
| |
| lock_device_hotplug(); |
| rc = try_remove_memory(nid, start, size); |
| unlock_device_hotplug(); |
| |
| return rc; |
| } |
| EXPORT_SYMBOL_GPL(remove_memory); |
| #endif /* CONFIG_MEMORY_HOTREMOVE */ |