v4.19.13 snapshot.
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
new file mode 100644
index 0000000..f3f9197
--- /dev/null
+++ b/mm/memory_hotplug.c
@@ -0,0 +1,1907 @@
+/*
+ * linux/mm/memory_hotplug.c
+ *
+ * Copyright (C)
+ */
+
+#include <linux/stddef.h>
+#include <linux/mm.h>
+#include <linux/sched/signal.h>
+#include <linux/swap.h>
+#include <linux/interrupt.h>
+#include <linux/pagemap.h>
+#include <linux/compiler.h>
+#include <linux/export.h>
+#include <linux/pagevec.h>
+#include <linux/writeback.h>
+#include <linux/slab.h>
+#include <linux/sysctl.h>
+#include <linux/cpu.h>
+#include <linux/memory.h>
+#include <linux/memremap.h>
+#include <linux/memory_hotplug.h>
+#include <linux/highmem.h>
+#include <linux/vmalloc.h>
+#include <linux/ioport.h>
+#include <linux/delay.h>
+#include <linux/migrate.h>
+#include <linux/page-isolation.h>
+#include <linux/pfn.h>
+#include <linux/suspend.h>
+#include <linux/mm_inline.h>
+#include <linux/firmware-map.h>
+#include <linux/stop_machine.h>
+#include <linux/hugetlb.h>
+#include <linux/memblock.h>
+#include <linux/bootmem.h>
+#include <linux/compaction.h>
+
+#include <asm/tlbflush.h>
+
+#include "internal.h"
+
+/*
+ * online_page_callback contains pointer to current page onlining function.
+ * Initially it is generic_online_page(). If it is required it could be
+ * changed by calling set_online_page_callback() for callback registration
+ * and restore_online_page_callback() for generic callback restore.
+ */
+
+static void generic_online_page(struct page *page);
+
+static online_page_callback_t online_page_callback = generic_online_page;
+static DEFINE_MUTEX(online_page_callback_lock);
+
+DEFINE_STATIC_PERCPU_RWSEM(mem_hotplug_lock);
+
+void get_online_mems(void)
+{
+ percpu_down_read(&mem_hotplug_lock);
+}
+
+void put_online_mems(void)
+{
+ percpu_up_read(&mem_hotplug_lock);
+}
+
+bool movable_node_enabled = false;
+
+#ifndef CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE
+bool memhp_auto_online;
+#else
+bool memhp_auto_online = true;
+#endif
+EXPORT_SYMBOL_GPL(memhp_auto_online);
+
+static int __init setup_memhp_default_state(char *str)
+{
+ if (!strcmp(str, "online"))
+ memhp_auto_online = true;
+ else if (!strcmp(str, "offline"))
+ memhp_auto_online = false;
+
+ return 1;
+}
+__setup("memhp_default_state=", setup_memhp_default_state);
+
+void mem_hotplug_begin(void)
+{
+ cpus_read_lock();
+ percpu_down_write(&mem_hotplug_lock);
+}
+
+void mem_hotplug_done(void)
+{
+ percpu_up_write(&mem_hotplug_lock);
+ cpus_read_unlock();
+}
+
+/* add this memory to iomem resource */
+static struct resource *register_memory_resource(u64 start, u64 size)
+{
+ struct resource *res, *conflict;
+ res = kzalloc(sizeof(struct resource), GFP_KERNEL);
+ if (!res)
+ return ERR_PTR(-ENOMEM);
+
+ res->name = "System RAM";
+ res->start = start;
+ res->end = start + size - 1;
+ res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
+ conflict = request_resource_conflict(&iomem_resource, res);
+ if (conflict) {
+ if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) {
+ pr_debug("Device unaddressable memory block "
+ "memory hotplug at %#010llx !\n",
+ (unsigned long long)start);
+ }
+ pr_debug("System RAM resource %pR cannot be added\n", res);
+ kfree(res);
+ return ERR_PTR(-EEXIST);
+ }
+ return res;
+}
+
+static void release_memory_resource(struct resource *res)
+{
+ if (!res)
+ return;
+ release_resource(res);
+ kfree(res);
+ return;
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
+void get_page_bootmem(unsigned long info, struct page *page,
+ unsigned long type)
+{
+ page->freelist = (void *)type;
+ SetPagePrivate(page);
+ set_page_private(page, info);
+ page_ref_inc(page);
+}
+
+void put_page_bootmem(struct page *page)
+{
+ unsigned long type;
+
+ type = (unsigned long) page->freelist;
+ BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
+ type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE);
+
+ if (page_ref_dec_return(page) == 1) {
+ page->freelist = NULL;
+ ClearPagePrivate(page);
+ set_page_private(page, 0);
+ INIT_LIST_HEAD(&page->lru);
+ free_reserved_page(page);
+ }
+}
+
+#ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE
+#ifndef CONFIG_SPARSEMEM_VMEMMAP
+static void register_page_bootmem_info_section(unsigned long start_pfn)
+{
+ unsigned long *usemap, mapsize, section_nr, i;
+ struct mem_section *ms;
+ struct page *page, *memmap;
+
+ section_nr = pfn_to_section_nr(start_pfn);
+ ms = __nr_to_section(section_nr);
+
+ /* Get section's memmap address */
+ memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
+
+ /*
+ * Get page for the memmap's phys address
+ * XXX: need more consideration for sparse_vmemmap...
+ */
+ page = virt_to_page(memmap);
+ mapsize = sizeof(struct page) * PAGES_PER_SECTION;
+ mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT;
+
+ /* remember memmap's page */
+ for (i = 0; i < mapsize; i++, page++)
+ get_page_bootmem(section_nr, page, SECTION_INFO);
+
+ usemap = ms->pageblock_flags;
+ page = virt_to_page(usemap);
+
+ mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT;
+
+ for (i = 0; i < mapsize; i++, page++)
+ get_page_bootmem(section_nr, page, MIX_SECTION_INFO);
+
+}
+#else /* CONFIG_SPARSEMEM_VMEMMAP */
+static void register_page_bootmem_info_section(unsigned long start_pfn)
+{
+ unsigned long *usemap, mapsize, section_nr, i;
+ struct mem_section *ms;
+ struct page *page, *memmap;
+
+ section_nr = pfn_to_section_nr(start_pfn);
+ ms = __nr_to_section(section_nr);
+
+ memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
+
+ register_page_bootmem_memmap(section_nr, memmap, PAGES_PER_SECTION);
+
+ usemap = ms->pageblock_flags;
+ page = virt_to_page(usemap);
+
+ mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT;
+
+ for (i = 0; i < mapsize; i++, page++)
+ get_page_bootmem(section_nr, page, MIX_SECTION_INFO);
+}
+#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
+
+void __init register_page_bootmem_info_node(struct pglist_data *pgdat)
+{
+ unsigned long i, pfn, end_pfn, nr_pages;
+ int node = pgdat->node_id;
+ struct page *page;
+
+ nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT;
+ page = virt_to_page(pgdat);
+
+ for (i = 0; i < nr_pages; i++, page++)
+ get_page_bootmem(node, page, NODE_INFO);
+
+ pfn = pgdat->node_start_pfn;
+ end_pfn = pgdat_end_pfn(pgdat);
+
+ /* register section info */
+ for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
+ /*
+ * Some platforms can assign the same pfn to multiple nodes - on
+ * node0 as well as nodeN. To avoid registering a pfn against
+ * multiple nodes we check that this pfn does not already
+ * reside in some other nodes.
+ */
+ if (pfn_valid(pfn) && (early_pfn_to_nid(pfn) == node))
+ register_page_bootmem_info_section(pfn);
+ }
+}
+#endif /* CONFIG_HAVE_BOOTMEM_INFO_NODE */
+
+static int __meminit __add_section(int nid, unsigned long phys_start_pfn,
+ struct vmem_altmap *altmap, bool want_memblock)
+{
+ int ret;
+
+ if (pfn_valid(phys_start_pfn))
+ return -EEXIST;
+
+ ret = sparse_add_one_section(NODE_DATA(nid), phys_start_pfn, altmap);
+ if (ret < 0)
+ return ret;
+
+ if (!want_memblock)
+ return 0;
+
+ return hotplug_memory_register(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, unsigned long phys_start_pfn,
+ unsigned long nr_pages, struct vmem_altmap *altmap,
+ bool want_memblock)
+{
+ unsigned long i;
+ int err = 0;
+ int start_sec, end_sec;
+
+ /* during initialize mem_map, align hot-added range to section */
+ start_sec = pfn_to_section_nr(phys_start_pfn);
+ end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1);
+
+ if (altmap) {
+ /*
+ * Validate altmap is within bounds of the total request
+ */
+ if (altmap->base_pfn != phys_start_pfn
+ || vmem_altmap_offset(altmap) > nr_pages) {
+ pr_warn_once("memory add fail, invalid altmap\n");
+ err = -EINVAL;
+ goto out;
+ }
+ altmap->alloc = 0;
+ }
+
+ for (i = start_sec; i <= end_sec; i++) {
+ err = __add_section(nid, section_nr_to_pfn(i), altmap,
+ want_memblock);
+
+ /*
+ * EEXIST is finally dealt with by ioresource collision
+ * check. see add_memory() => register_memory_resource()
+ * Warning will be printed if there is collision.
+ */
+ if (err && (err != -EEXIST))
+ break;
+ err = 0;
+ cond_resched();
+ }
+ vmemmap_populate_print_last();
+out:
+ return err;
+}
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+/* 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)
+{
+ 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 unsigned long 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;
+ unsigned long flags;
+
+ 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 map_offset, struct vmem_altmap *altmap)
+{
+ 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((unsigned long)scn_nr);
+ __remove_zone(zone, start_pfn);
+
+ sparse_remove_one_section(zone, ms, map_offset, altmap);
+ 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)
+ * @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().
+ */
+int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
+ unsigned long nr_pages, struct vmem_altmap *altmap)
+{
+ unsigned long i;
+ unsigned long map_offset = 0;
+ int sections_to_remove, ret = 0;
+
+ /* In the ZONE_DEVICE case device driver owns the memory region */
+ if (is_dev_zone(zone)) {
+ if (altmap)
+ map_offset = vmem_altmap_offset(altmap);
+ } else {
+ resource_size_t start, size;
+
+ 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);
+ }
+ }
+
+ clear_zone_contiguous(zone);
+
+ /*
+ * We can only remove entire sections
+ */
+ BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK);
+ BUG_ON(nr_pages % PAGES_PER_SECTION);
+
+ sections_to_remove = nr_pages / PAGES_PER_SECTION;
+ for (i = 0; i < sections_to_remove; i++) {
+ unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION;
+
+ cond_resched();
+ ret = __remove_section(zone, __pfn_to_section(pfn), map_offset,
+ altmap);
+ map_offset = 0;
+ if (ret)
+ break;
+ }
+
+ set_zone_contiguous(zone);
+
+ return ret;
+}
+#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++;
+ }
+
+ online_mem_sections(start_pfn, start_pfn + nr_pages);
+
+ *(unsigned long *)arg = onlined_pages;
+ return 0;
+}
+
+/* check which state of node_states will be changed when online memory */
+static void node_states_check_changes_online(unsigned long nr_pages,
+ struct zone *zone, struct memory_notify *arg)
+{
+ int nid = zone_to_nid(zone);
+ enum zone_type zone_last = ZONE_NORMAL;
+
+ /*
+ * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY]
+ * contains nodes which have zones of 0...ZONE_NORMAL,
+ * set zone_last to ZONE_NORMAL.
+ *
+ * If we don't have HIGHMEM nor movable node,
+ * node_states[N_NORMAL_MEMORY] contains nodes which have zones of
+ * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE.
+ */
+ if (N_MEMORY == N_NORMAL_MEMORY)
+ zone_last = ZONE_MOVABLE;
+
+ /*
+ * if the memory to be online is in a zone of 0...zone_last, and
+ * the zones of 0...zone_last don't have memory before online, we will
+ * need to set the node to node_states[N_NORMAL_MEMORY] after
+ * the memory is online.
+ */
+ if (zone_idx(zone) <= zone_last && !node_state(nid, N_NORMAL_MEMORY))
+ arg->status_change_nid_normal = nid;
+ else
+ arg->status_change_nid_normal = -1;
+
+#ifdef CONFIG_HIGHMEM
+ /*
+ * If we have movable node, node_states[N_HIGH_MEMORY]
+ * contains nodes which have zones of 0...ZONE_HIGHMEM,
+ * set zone_last to ZONE_HIGHMEM.
+ *
+ * If we don't have movable node, node_states[N_NORMAL_MEMORY]
+ * contains nodes which have zones of 0...ZONE_MOVABLE,
+ * set zone_last to ZONE_MOVABLE.
+ */
+ zone_last = ZONE_HIGHMEM;
+ if (N_MEMORY == N_HIGH_MEMORY)
+ zone_last = ZONE_MOVABLE;
+
+ if (zone_idx(zone) <= zone_last && !node_state(nid, N_HIGH_MEMORY))
+ arg->status_change_nid_high = nid;
+ else
+ arg->status_change_nid_high = -1;
+#else
+ arg->status_change_nid_high = arg->status_change_nid_normal;
+#endif
+
+ /*
+ * if the node don't have memory befor online, we will need to
+ * set the node to node_states[N_MEMORY] after the memory
+ * is online.
+ */
+ if (!node_state(nid, N_MEMORY))
+ arg->status_change_nid = nid;
+ else
+ arg->status_change_nid = -1;
+}
+
+static void node_states_set_node(int node, struct memory_notify *arg)
+{
+ if (arg->status_change_nid_normal >= 0)
+ node_set_state(node, N_NORMAL_MEMORY);
+
+ if (arg->status_change_nid_high >= 0)
+ node_set_state(node, N_HIGH_MEMORY);
+
+ node_set_state(node, N_MEMORY);
+}
+
+static void __meminit resize_zone_range(struct zone *zone, unsigned long start_pfn,
+ unsigned long nr_pages)
+{
+ unsigned long old_end_pfn = zone_end_pfn(zone);
+
+ if (zone_is_empty(zone) || start_pfn < zone->zone_start_pfn)
+ zone->zone_start_pfn = start_pfn;
+
+ zone->spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - zone->zone_start_pfn;
+}
+
+static void __meminit resize_pgdat_range(struct pglist_data *pgdat, unsigned long start_pfn,
+ unsigned long nr_pages)
+{
+ unsigned long old_end_pfn = pgdat_end_pfn(pgdat);
+
+ if (!pgdat->node_spanned_pages || start_pfn < pgdat->node_start_pfn)
+ pgdat->node_start_pfn = start_pfn;
+
+ pgdat->node_spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - pgdat->node_start_pfn;
+}
+
+void __ref move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn,
+ unsigned long nr_pages, struct vmem_altmap *altmap)
+{
+ struct pglist_data *pgdat = zone->zone_pgdat;
+ int nid = pgdat->node_id;
+ unsigned long flags;
+
+ if (zone_is_empty(zone))
+ init_currently_empty_zone(zone, start_pfn, nr_pages);
+
+ clear_zone_contiguous(zone);
+
+ /* TODO Huh pgdat is irqsave while zone is not. It used to be like that before */
+ pgdat_resize_lock(pgdat, &flags);
+ zone_span_writelock(zone);
+ resize_zone_range(zone, start_pfn, nr_pages);
+ zone_span_writeunlock(zone);
+ resize_pgdat_range(pgdat, start_pfn, nr_pages);
+ pgdat_resize_unlock(pgdat, &flags);
+
+ /*
+ * TODO now we have a visible range of pages which are not associated
+ * with their zone properly. Not nice but set_pfnblock_flags_mask
+ * expects the zone spans the pfn range. All the pages in the range
+ * are reserved so nobody should be touching them so we should be safe
+ */
+ memmap_init_zone(nr_pages, nid, zone_idx(zone), start_pfn,
+ 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);
+}
+
+/*
+ * Associates the given pfn range with the given node and the zone appropriate
+ * for the given online type.
+ */
+static struct zone * __meminit move_pfn_range(int online_type, int nid,
+ unsigned long start_pfn, unsigned long nr_pages)
+{
+ struct zone *zone;
+
+ zone = zone_for_pfn_range(online_type, nid, start_pfn, nr_pages);
+ move_pfn_range_to_zone(zone, start_pfn, nr_pages, NULL);
+ return zone;
+}
+
+/* Must be protected by mem_hotplug_begin() or a device_lock */
+int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_type)
+{
+ unsigned long flags;
+ unsigned long onlined_pages = 0;
+ struct zone *zone;
+ int need_zonelists_rebuild = 0;
+ int nid;
+ int ret;
+ struct memory_notify arg;
+ struct memory_block *mem;
+
+ /*
+ * We can't use pfn_to_nid() because nid might be stored in struct page
+ * which is not yet initialized. Instead, we find nid from memory block.
+ */
+ mem = find_memory_block(__pfn_to_section(pfn));
+ nid = mem->nid;
+
+ /* associate pfn range with the zone */
+ zone = move_pfn_range(online_type, nid, pfn, nr_pages);
+
+ arg.start_pfn = pfn;
+ arg.nr_pages = nr_pages;
+ node_states_check_changes_online(nr_pages, zone, &arg);
+
+ ret = memory_notify(MEM_GOING_ONLINE, &arg);
+ ret = notifier_to_errno(ret);
+ if (ret)
+ goto failed_addition;
+
+ /*
+ * If this zone is not populated, then it is not in zonelist.
+ * This means the page allocator ignores this zone.
+ * So, zonelist must be updated after online.
+ */
+ if (!populated_zone(zone)) {
+ need_zonelists_rebuild = 1;
+ setup_zone_pageset(zone);
+ }
+
+ ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages,
+ online_pages_range);
+ if (ret) {
+ if (need_zonelists_rebuild)
+ zone_pcp_reset(zone);
+ goto failed_addition;
+ }
+
+ zone->present_pages += onlined_pages;
+
+ pgdat_resize_lock(zone->zone_pgdat, &flags);
+ zone->zone_pgdat->node_present_pages += onlined_pages;
+ pgdat_resize_unlock(zone->zone_pgdat, &flags);
+
+ if (onlined_pages) {
+ node_states_set_node(nid, &arg);
+ if (need_zonelists_rebuild)
+ build_all_zonelists(NULL);
+ else
+ zone_pcp_update(zone);
+ }
+
+ init_per_zone_wmark_min();
+
+ if (onlined_pages) {
+ kswapd_run(nid);
+ kcompactd_run(nid);
+ }
+
+ vm_total_pages = nr_free_pagecache_pages();
+
+ writeback_set_ratelimit();
+
+ if (onlined_pages)
+ memory_notify(MEM_ONLINE, &arg);
+ 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);
+ return ret;
+}
+#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
+
+static void reset_node_present_pages(pg_data_t *pgdat)
+{
+ struct zone *z;
+
+ for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
+ z->present_pages = 0;
+
+ pgdat->node_present_pages = 0;
+}
+
+/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
+static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
+{
+ struct pglist_data *pgdat;
+ unsigned long start_pfn = PFN_DOWN(start);
+
+ pgdat = NODE_DATA(nid);
+ if (!pgdat) {
+ pgdat = arch_alloc_nodedata(nid);
+ if (!pgdat)
+ return NULL;
+
+ arch_refresh_nodedata(nid, pgdat);
+ } else {
+ /*
+ * Reset the nr_zones, order and classzone_idx before reuse.
+ * Note that kswapd will init kswapd_classzone_idx properly
+ * when it starts in the near future.
+ */
+ pgdat->nr_zones = 0;
+ pgdat->kswapd_order = 0;
+ pgdat->kswapd_classzone_idx = 0;
+ }
+
+ /* we can use NODE_DATA(nid) from here */
+
+ pgdat->node_id = nid;
+ pgdat->node_start_pfn = start_pfn;
+
+ /* init node's zones as empty zones, we don't have any present pages.*/
+ free_area_init_core_hotplug(nid);
+ pgdat->per_cpu_nodestats = alloc_percpu(struct per_cpu_nodestat);
+
+ /*
+ * The node we allocated has no zone fallback lists. For avoiding
+ * to access not-initialized zonelist, build here.
+ */
+ build_all_zonelists(pgdat);
+
+ /*
+ * When memory is hot-added, all the memory is in offline state. So
+ * clear all zones' present_pages because they will be updated in
+ * online_pages() and offline_pages().
+ */
+ reset_node_managed_pages(pgdat);
+ reset_node_present_pages(pgdat);
+
+ return pgdat;
+}
+
+static void rollback_node_hotadd(int nid)
+{
+ pg_data_t *pgdat = NODE_DATA(nid);
+
+ arch_refresh_nodedata(nid, NULL);
+ free_percpu(pgdat->per_cpu_nodestats);
+ arch_free_nodedata(pgdat);
+ return;
+}
+
+
+/**
+ * try_online_node - online a node if offlined
+ * @nid: the node ID
+ * @start: start addr of the node
+ * @set_node_online: Whether we want to online the node
+ * called by cpu_up() to online a node without onlined memory.
+ *
+ * Returns:
+ * 1 -> a new node has been allocated
+ * 0 -> the node is already online
+ * -ENOMEM -> the node could not be allocated
+ */
+static int __try_online_node(int nid, u64 start, bool set_node_online)
+{
+ pg_data_t *pgdat;
+ int ret = 1;
+
+ if (node_online(nid))
+ return 0;
+
+ pgdat = hotadd_new_pgdat(nid, start);
+ if (!pgdat) {
+ pr_err("Cannot online node %d due to NULL pgdat\n", nid);
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ if (set_node_online) {
+ node_set_online(nid);
+ ret = register_one_node(nid);
+ BUG_ON(ret);
+ }
+out:
+ return ret;
+}
+
+/*
+ * Users of this function always want to online/register the node
+ */
+int try_online_node(int nid)
+{
+ int ret;
+
+ mem_hotplug_begin();
+ ret = __try_online_node(nid, 0, true);
+ mem_hotplug_done();
+ return ret;
+}
+
+static int check_hotplug_memory_range(u64 start, u64 size)
+{
+ unsigned long block_sz = memory_block_size_bytes();
+ u64 block_nr_pages = block_sz >> PAGE_SHIFT;
+ u64 nr_pages = size >> PAGE_SHIFT;
+ u64 start_pfn = PFN_DOWN(start);
+
+ /* memory range must be block size aligned */
+ if (!nr_pages || !IS_ALIGNED(start_pfn, block_nr_pages) ||
+ !IS_ALIGNED(nr_pages, block_nr_pages)) {
+ pr_err("Block size [%#lx] unaligned hotplug range: start %#llx, size %#llx",
+ block_sz, start, size);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int online_memory_block(struct memory_block *mem, void *arg)
+{
+ return device_online(&mem->dev);
+}
+
+/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
+int __ref add_memory_resource(int nid, struct resource *res, bool online)
+{
+ u64 start, size;
+ bool new_node = false;
+ int ret;
+
+ start = res->start;
+ size = resource_size(res);
+
+ ret = check_hotplug_memory_range(start, size);
+ if (ret)
+ return ret;
+
+ mem_hotplug_begin();
+
+ /*
+ * Add new range to memblock so that when hotadd_new_pgdat() is called
+ * to allocate new pgdat, get_pfn_range_for_nid() will be able to find
+ * this new range and calculate total pages correctly. The range will
+ * be removed at hot-remove time.
+ */
+ memblock_add_node(start, size, nid);
+
+ ret = __try_online_node(nid, start, false);
+ if (ret < 0)
+ goto error;
+ new_node = ret;
+
+ /* call arch's memory hotadd */
+ ret = arch_add_memory(nid, start, size, NULL, true);
+ if (ret < 0)
+ goto error;
+
+ 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 */
+ firmware_map_add_hotplug(start, start + size, "System RAM");
+
+ /* online pages if requested */
+ if (online)
+ walk_memory_range(PFN_DOWN(start), PFN_UP(start + size - 1),
+ NULL, online_memory_block);
+
+ goto out;
+
+error:
+ /* rollback pgdat allocation and others */
+ if (new_node)
+ rollback_node_hotadd(nid);
+ memblock_remove(start, size);
+
+out:
+ mem_hotplug_done();
+ return ret;
+}
+EXPORT_SYMBOL_GPL(add_memory_resource);
+
+int __ref add_memory(int nid, u64 start, u64 size)
+{
+ struct resource *res;
+ int ret;
+
+ res = register_memory_resource(start, size);
+ if (IS_ERR(res))
+ return PTR_ERR(res);
+
+ ret = add_memory_resource(nid, res, memhp_auto_online);
+ if (ret < 0)
+ release_memory_resource(res);
+ return ret;
+}
+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;
+}
+
+static bool is_pageblock_removable_nolock(struct page *page)
+{
+ struct zone *zone;
+ unsigned long pfn;
+
+ /*
+ * We have to be careful here because we are iterating over memory
+ * sections which are not zone aware so we might end up outside of
+ * the zone but still within the section.
+ * We have to take care about the node as well. If the node is offline
+ * its NODE_DATA will be NULL - see page_zone.
+ */
+ if (!node_online(page_to_nid(page)))
+ return false;
+
+ zone = page_zone(page);
+ pfn = page_to_pfn(page);
+ if (!zone_spans_pfn(zone, pfn))
+ return false;
+
+ return !has_unmovable_pages(zone, page, 0, MIGRATE_MOVABLE, true);
+}
+
+/* Checks if this range of memory is likely to be hot-removable. */
+bool is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages)
+{
+ 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 false;
+ cond_resched();
+ }
+
+ /* All pageblocks in the memory block are likely to be hot-removable */
+ return true;
+}
+
+/*
+ * Confirm all pages in a range [start, end) belong to the same zone.
+ * When true, return its valid [start, end).
+ */
+int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn,
+ unsigned long *valid_start, unsigned long *valid_end)
+{
+ unsigned long pfn, sec_end_pfn;
+ unsigned long start, end;
+ struct zone *zone = NULL;
+ struct page *page;
+ int i;
+ for (pfn = start_pfn, sec_end_pfn = SECTION_ALIGN_UP(start_pfn + 1);
+ pfn < end_pfn;
+ pfn = sec_end_pfn, sec_end_pfn += PAGES_PER_SECTION) {
+ /* Make sure the memory section is present first */
+ if (!present_section_nr(pfn_to_section_nr(pfn)))
+ continue;
+ for (; pfn < sec_end_pfn && pfn < end_pfn;
+ pfn += MAX_ORDER_NR_PAGES) {
+ i = 0;
+ /* This is just a CONFIG_HOLES_IN_ZONE check.*/
+ while ((i < MAX_ORDER_NR_PAGES) &&
+ !pfn_valid_within(pfn + i))
+ i++;
+ if (i == MAX_ORDER_NR_PAGES || pfn + i >= end_pfn)
+ continue;
+ page = pfn_to_page(pfn + i);
+ if (zone && page_zone(page) != zone)
+ return 0;
+ if (!zone)
+ start = pfn + i;
+ zone = page_zone(page);
+ end = pfn + MAX_ORDER_NR_PAGES;
+ }
+ }
+
+ if (zone) {
+ *valid_start = start;
+ *valid_end = min(end, end_pfn);
+ return 1;
+ } else {
+ return 0;
+ }
+}
+
+/*
+ * Scan pfn range [start,end) to find movable/migratable pages (LRU pages,
+ * non-lru movable pages and hugepages). We scan pfn because it's much
+ * easier than scanning over linked list. This function returns the pfn
+ * of the first found movable page if it's found, otherwise 0.
+ */
+static unsigned long scan_movable_pages(unsigned long start, unsigned long end)
+{
+ unsigned long pfn;
+ struct page *page;
+ for (pfn = start; pfn < end; pfn++) {
+ if (pfn_valid(pfn)) {
+ page = pfn_to_page(pfn);
+ if (PageLRU(page))
+ return pfn;
+ if (__PageMovable(page))
+ return pfn;
+ if (PageHuge(page)) {
+ if (hugepage_migration_supported(page_hstate(page)) &&
+ page_huge_active(page))
+ return pfn;
+ else
+ pfn = round_up(pfn + 1,
+ 1 << compound_order(page)) - 1;
+ }
+ }
+ }
+ return 0;
+}
+
+static struct page *new_node_page(struct page *page, unsigned long private)
+{
+ int nid = page_to_nid(page);
+ nodemask_t nmask = node_states[N_MEMORY];
+
+ /*
+ * try to allocate from a different node but reuse this node if there
+ * are no other online nodes to be used (e.g. we are offlining a part
+ * of the only existing node)
+ */
+ node_clear(nid, nmask);
+ if (nodes_empty(nmask))
+ node_set(nid, nmask);
+
+ return new_page_nodemask(page, nid, &nmask);
+}
+
+#define NR_OFFLINE_AT_ONCE_PAGES (256)
+static int
+do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
+{
+ unsigned long pfn;
+ struct page *page;
+ int move_pages = NR_OFFLINE_AT_ONCE_PAGES;
+ int not_managed = 0;
+ int ret = 0;
+ LIST_HEAD(source);
+
+ for (pfn = start_pfn; pfn < end_pfn && move_pages > 0; pfn++) {
+ if (!pfn_valid(pfn))
+ continue;
+ page = pfn_to_page(pfn);
+
+ if (PageHuge(page)) {
+ struct page *head = compound_head(page);
+ pfn = page_to_pfn(head) + (1<<compound_order(head)) - 1;
+ if (compound_order(head) > PFN_SECTION_SHIFT) {
+ ret = -EBUSY;
+ break;
+ }
+ if (isolate_huge_page(page, &source))
+ move_pages -= 1 << compound_order(head);
+ continue;
+ } else if (PageTransHuge(page))
+ pfn = page_to_pfn(compound_head(page))
+ + hpage_nr_pages(page) - 1;
+
+ if (!get_page_unless_zero(page))
+ continue;
+ /*
+ * We can skip free pages. And we can deal with pages on
+ * LRU and non-lru movable pages.
+ */
+ if (PageLRU(page))
+ ret = isolate_lru_page(page);
+ else
+ ret = isolate_movable_page(page, ISOLATE_UNEVICTABLE);
+ if (!ret) { /* Success */
+ put_page(page);
+ list_add_tail(&page->lru, &source);
+ move_pages--;
+ if (!__PageMovable(page))
+ inc_node_page_state(page, NR_ISOLATED_ANON +
+ page_is_file_cache(page));
+
+ } else {
+#ifdef CONFIG_DEBUG_VM
+ pr_alert("failed to isolate pfn %lx\n", pfn);
+ dump_page(page, "isolation failed");
+#endif
+ put_page(page);
+ /* Because we don't have big zone->lock. we should
+ check this again here. */
+ if (page_count(page)) {
+ not_managed++;
+ ret = -EBUSY;
+ break;
+ }
+ }
+ }
+ if (!list_empty(&source)) {
+ if (not_managed) {
+ putback_movable_pages(&source);
+ goto out;
+ }
+
+ /* Allocate a new page from the nearest neighbor node */
+ ret = migrate_pages(&source, new_node_page, NULL, 0,
+ MIGRATE_SYNC, MR_MEMORY_HOTPLUG);
+ if (ret)
+ putback_movable_pages(&source);
+ }
+out:
+ return ret;
+}
+
+/*
+ * remove from free_area[] and mark all as Reserved.
+ */
+static int
+offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages,
+ void *data)
+{
+ __offline_isolated_pages(start, start + nr_pages);
+ return 0;
+}
+
+static void
+offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
+{
+ walk_system_ram_range(start_pfn, end_pfn - start_pfn, NULL,
+ offline_isolated_pages_cb);
+}
+
+/*
+ * Check all pages in range, recoreded as memory resource, are isolated.
+ */
+static int
+check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages,
+ void *data)
+{
+ int ret;
+ long offlined = *(long *)data;
+ ret = test_pages_isolated(start_pfn, start_pfn + nr_pages, true);
+ offlined = nr_pages;
+ if (!ret)
+ *(long *)data += offlined;
+ return ret;
+}
+
+static long
+check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
+{
+ long offlined = 0;
+ int ret;
+
+ ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn, &offlined,
+ check_pages_isolated_cb);
+ if (ret < 0)
+ offlined = (long)ret;
+ return offlined;
+}
+
+static int __init cmdline_parse_movable_node(char *p)
+{
+#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
+ movable_node_enabled = true;
+#else
+ pr_warn("movable_node parameter depends on CONFIG_HAVE_MEMBLOCK_NODE_MAP to work properly\n");
+#endif
+ return 0;
+}
+early_param("movable_node", cmdline_parse_movable_node);
+
+/* check which state of node_states will be changed when offline memory */
+static void node_states_check_changes_offline(unsigned long nr_pages,
+ struct zone *zone, struct memory_notify *arg)
+{
+ struct pglist_data *pgdat = zone->zone_pgdat;
+ unsigned long present_pages = 0;
+ enum zone_type zt, zone_last = ZONE_NORMAL;
+
+ /*
+ * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY]
+ * contains nodes which have zones of 0...ZONE_NORMAL,
+ * set zone_last to ZONE_NORMAL.
+ *
+ * If we don't have HIGHMEM nor movable node,
+ * node_states[N_NORMAL_MEMORY] contains nodes which have zones of
+ * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE.
+ */
+ if (N_MEMORY == N_NORMAL_MEMORY)
+ zone_last = ZONE_MOVABLE;
+
+ /*
+ * check whether node_states[N_NORMAL_MEMORY] will be changed.
+ * If the memory to be offline is in a zone of 0...zone_last,
+ * and it is the last present memory, 0...zone_last will
+ * become empty after offline , thus we can determind we will
+ * need to clear the node from node_states[N_NORMAL_MEMORY].
+ */
+ for (zt = 0; zt <= zone_last; zt++)
+ present_pages += pgdat->node_zones[zt].present_pages;
+ if (zone_idx(zone) <= zone_last && nr_pages >= present_pages)
+ arg->status_change_nid_normal = zone_to_nid(zone);
+ else
+ arg->status_change_nid_normal = -1;
+
+#ifdef CONFIG_HIGHMEM
+ /*
+ * If we have movable node, node_states[N_HIGH_MEMORY]
+ * contains nodes which have zones of 0...ZONE_HIGHMEM,
+ * set zone_last to ZONE_HIGHMEM.
+ *
+ * If we don't have movable node, node_states[N_NORMAL_MEMORY]
+ * contains nodes which have zones of 0...ZONE_MOVABLE,
+ * set zone_last to ZONE_MOVABLE.
+ */
+ zone_last = ZONE_HIGHMEM;
+ if (N_MEMORY == N_HIGH_MEMORY)
+ zone_last = ZONE_MOVABLE;
+
+ for (; zt <= zone_last; zt++)
+ present_pages += pgdat->node_zones[zt].present_pages;
+ if (zone_idx(zone) <= zone_last && nr_pages >= present_pages)
+ arg->status_change_nid_high = zone_to_nid(zone);
+ else
+ arg->status_change_nid_high = -1;
+#else
+ arg->status_change_nid_high = arg->status_change_nid_normal;
+#endif
+
+ /*
+ * node_states[N_HIGH_MEMORY] contains nodes which have 0...ZONE_MOVABLE
+ */
+ zone_last = ZONE_MOVABLE;
+
+ /*
+ * check whether node_states[N_HIGH_MEMORY] will be changed
+ * If we try to offline the last present @nr_pages from the node,
+ * we can determind we will need to clear the node from
+ * node_states[N_HIGH_MEMORY].
+ */
+ for (; zt <= zone_last; zt++)
+ present_pages += pgdat->node_zones[zt].present_pages;
+ if (nr_pages >= present_pages)
+ arg->status_change_nid = zone_to_nid(zone);
+ else
+ arg->status_change_nid = -1;
+}
+
+static void node_states_clear_node(int node, struct memory_notify *arg)
+{
+ if (arg->status_change_nid_normal >= 0)
+ node_clear_state(node, N_NORMAL_MEMORY);
+
+ if ((N_MEMORY != N_NORMAL_MEMORY) &&
+ (arg->status_change_nid_high >= 0))
+ node_clear_state(node, N_HIGH_MEMORY);
+
+ if ((N_MEMORY != N_HIGH_MEMORY) &&
+ (arg->status_change_nid >= 0))
+ node_clear_state(node, N_MEMORY);
+}
+
+static int __ref __offline_pages(unsigned long start_pfn,
+ unsigned long end_pfn)
+{
+ unsigned long pfn, nr_pages;
+ long offlined_pages;
+ int ret, node;
+ unsigned long flags;
+ unsigned long valid_start, valid_end;
+ struct zone *zone;
+ struct memory_notify arg;
+
+ /* at least, alignment against pageblock is necessary */
+ if (!IS_ALIGNED(start_pfn, pageblock_nr_pages))
+ return -EINVAL;
+ if (!IS_ALIGNED(end_pfn, pageblock_nr_pages))
+ return -EINVAL;
+ /* This makes hotplug much easier...and readable.
+ we assume this for now. .*/
+ if (!test_pages_in_a_zone(start_pfn, end_pfn, &valid_start, &valid_end))
+ return -EINVAL;
+
+ zone = page_zone(pfn_to_page(valid_start));
+ node = zone_to_nid(zone);
+ nr_pages = end_pfn - start_pfn;
+
+ /* set above range as isolated */
+ ret = start_isolate_page_range(start_pfn, end_pfn,
+ MIGRATE_MOVABLE, true);
+ if (ret)
+ return ret;
+
+ arg.start_pfn = start_pfn;
+ arg.nr_pages = nr_pages;
+ node_states_check_changes_offline(nr_pages, zone, &arg);
+
+ ret = memory_notify(MEM_GOING_OFFLINE, &arg);
+ ret = notifier_to_errno(ret);
+ if (ret)
+ goto failed_removal;
+
+ pfn = start_pfn;
+repeat:
+ /* start memory hot removal */
+ ret = -EINTR;
+ if (signal_pending(current))
+ goto failed_removal;
+
+ cond_resched();
+ lru_add_drain_all();
+ drain_all_pages(zone);
+
+ pfn = scan_movable_pages(start_pfn, end_pfn);
+ if (pfn) { /* We have movable pages */
+ ret = do_migrate_range(pfn, end_pfn);
+ goto repeat;
+ }
+
+ /*
+ * dissolve free hugepages in the memory block before doing offlining
+ * actually in order to make hugetlbfs's object counting consistent.
+ */
+ ret = dissolve_free_huge_pages(start_pfn, end_pfn);
+ if (ret)
+ goto failed_removal;
+ /* check again */
+ offlined_pages = check_pages_isolated(start_pfn, end_pfn);
+ if (offlined_pages < 0)
+ goto repeat;
+ pr_info("Offlined Pages %ld\n", offlined_pages);
+ /* Ok, all of our target is isolated.
+ We cannot do rollback at this point. */
+ offline_isolated_pages(start_pfn, end_pfn);
+ /* reset pagetype flags and makes migrate type to be MOVABLE */
+ undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE);
+ /* removal success */
+ adjust_managed_page_count(pfn_to_page(start_pfn), -offlined_pages);
+ zone->present_pages -= offlined_pages;
+
+ pgdat_resize_lock(zone->zone_pgdat, &flags);
+ zone->zone_pgdat->node_present_pages -= offlined_pages;
+ pgdat_resize_unlock(zone->zone_pgdat, &flags);
+
+ init_per_zone_wmark_min();
+
+ if (!populated_zone(zone)) {
+ zone_pcp_reset(zone);
+ build_all_zonelists(NULL);
+ } else
+ zone_pcp_update(zone);
+
+ node_states_clear_node(node, &arg);
+ if (arg.status_change_nid >= 0) {
+ kswapd_stop(node);
+ kcompactd_stop(node);
+ }
+
+ vm_total_pages = nr_free_pagecache_pages();
+ writeback_set_ratelimit();
+
+ memory_notify(MEM_OFFLINE, &arg);
+ return 0;
+
+failed_removal:
+ pr_debug("memory offlining [mem %#010llx-%#010llx] failed\n",
+ (unsigned long long) start_pfn << PAGE_SHIFT,
+ ((unsigned long long) end_pfn << PAGE_SHIFT) - 1);
+ memory_notify(MEM_CANCEL_OFFLINE, &arg);
+ /* pushback to free area */
+ undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE);
+ return ret;
+}
+
+/* Must be protected by mem_hotplug_begin() or a device_lock */
+int offline_pages(unsigned long start_pfn, unsigned long nr_pages)
+{
+ return __offline_pages(start_pfn, start_pfn + nr_pages);
+}
+#endif /* CONFIG_MEMORY_HOTREMOVE */
+
+/**
+ * walk_memory_range - walks through all mem sections in [start_pfn, end_pfn)
+ * @start_pfn: start pfn of the memory range
+ * @end_pfn: end pfn of the memory range
+ * @arg: argument passed to func
+ * @func: callback for each memory section walked
+ *
+ * This function walks through all present mem sections in range
+ * [start_pfn, end_pfn) and call func on each mem section.
+ *
+ * Returns the return value of func.
+ */
+int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn,
+ void *arg, int (*func)(struct memory_block *, void *))
+{
+ struct memory_block *mem = NULL;
+ struct mem_section *section;
+ unsigned long pfn, section_nr;
+ int ret;
+
+ for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
+ section_nr = pfn_to_section_nr(pfn);
+ if (!present_section_nr(section_nr))
+ continue;
+
+ section = __nr_to_section(section_nr);
+ /* same memblock? */
+ if (mem)
+ if ((section_nr >= mem->start_section_nr) &&
+ (section_nr <= mem->end_section_nr))
+ continue;
+
+ mem = find_memory_block_hinted(section, mem);
+ if (!mem)
+ continue;
+
+ ret = func(mem, arg);
+ if (ret) {
+ kobject_put(&mem->dev.kobj);
+ return ret;
+ }
+ }
+
+ if (mem)
+ kobject_put(&mem->dev.kobj);
+
+ return 0;
+}
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+static int check_memblock_offlined_cb(struct memory_block *mem, void *arg)
+{
+ int ret = !is_memblock_offlined(mem);
+
+ if (unlikely(ret)) {
+ phys_addr_t beginpa, endpa;
+
+ beginpa = PFN_PHYS(section_nr_to_pfn(mem->start_section_nr));
+ endpa = PFN_PHYS(section_nr_to_pfn(mem->end_section_nr + 1))-1;
+ pr_warn("removing memory fails, because memory [%pa-%pa] is onlined\n",
+ &beginpa, &endpa);
+ }
+
+ return ret;
+}
+
+static int check_cpu_on_node(pg_data_t *pgdat)
+{
+ int cpu;
+
+ for_each_present_cpu(cpu) {
+ if (cpu_to_node(cpu) == pgdat->node_id)
+ /*
+ * the cpu on this node isn't removed, and we can't
+ * offline this node.
+ */
+ return -EBUSY;
+ }
+
+ return 0;
+}
+
+static void unmap_cpu_on_node(pg_data_t *pgdat)
+{
+#ifdef CONFIG_ACPI_NUMA
+ int cpu;
+
+ for_each_possible_cpu(cpu)
+ if (cpu_to_node(cpu) == pgdat->node_id)
+ numa_clear_node(cpu);
+#endif
+}
+
+static int check_and_unmap_cpu_on_node(pg_data_t *pgdat)
+{
+ int ret;
+
+ ret = check_cpu_on_node(pgdat);
+ if (ret)
+ return ret;
+
+ /*
+ * the node will be offlined when we come here, so we can clear
+ * the cpu_to_node() now.
+ */
+
+ unmap_cpu_on_node(pgdat);
+ return 0;
+}
+
+/**
+ * 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);
+ unsigned long start_pfn = pgdat->node_start_pfn;
+ unsigned long end_pfn = start_pfn + pgdat->node_spanned_pages;
+ unsigned long pfn;
+
+ 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);
+}
+EXPORT_SYMBOL(try_offline_node);
+
+/**
+ * remove_memory
+ * @nid: the node ID
+ * @start: physical address of the region to remove
+ * @size: size of the region to remove
+ *
+ * NOTE: The caller must call lock_device_hotplug() to serialize hotplug
+ * and online/offline operations before this call, as required by
+ * try_offline_node().
+ */
+void __ref remove_memory(int nid, u64 start, u64 size)
+{
+ int ret;
+
+ BUG_ON(check_hotplug_memory_range(start, size));
+
+ 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");
+ memblock_free(start, size);
+ memblock_remove(start, size);
+
+ arch_remove_memory(start, size, NULL);
+
+ try_offline_node(nid);
+
+ mem_hotplug_done();
+}
+EXPORT_SYMBOL_GPL(remove_memory);
+#endif /* CONFIG_MEMORY_HOTREMOVE */