blob: 85467914ad23dac4461bcd0b0a222ad748e6d642 [file] [log] [blame]
// 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 void generic_online_page(struct page *page, unsigned int order);
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();
}
u64 max_mem_size = U64_MAX;
/* add this memory to iomem resource */
static struct resource *register_memory_resource(u64 start, u64 size)
{
struct resource *res;
unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
char *resource_name = "System RAM";
if (start + size > max_mem_size)
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);
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 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 __meminit __add_section(int nid, unsigned long phys_start_pfn,
struct vmem_altmap *altmap)
{
int ret;
if (pfn_valid(phys_start_pfn))
return -EEXIST;
ret = sparse_add_one_section(nid, phys_start_pfn, altmap);
return ret < 0 ? ret : 0;
}
/*
* Reasonably generic function for adding memory. It is
* expected that archs that support memory hotplug will
* call this function after deciding the zone to which to
* add the new pages.
*/
int __ref __add_pages(int nid, unsigned long phys_start_pfn,
unsigned long nr_pages, struct mhp_restrictions *restrictions)
{
unsigned long i;
int err = 0;
int start_sec, end_sec;
struct vmem_altmap *altmap = restrictions->altmap;
/* 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);
/*
* EEXIST is finally dealt with by ioresource collision
* check. see add_memory() => register_memory_resource()
* Warning will be printed if there is collision.
*/
if (err && (err != -EEXIST))
break;
err = 0;
cond_resched();
}
vmemmap_populate_print_last();
out:
return err;
}
/* find the smallest valid pfn in the range [start_pfn, end_pfn) */
static unsigned long find_smallest_section_pfn(int nid, struct zone *zone,
unsigned long start_pfn,
unsigned long end_pfn)
{
for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SUBSECTION) {
if (unlikely(!pfn_valid(start_pfn)))
continue;
if (unlikely(pfn_to_nid(start_pfn) != nid))
continue;
if (zone && zone != page_zone(pfn_to_page(start_pfn)))
continue;
return start_pfn;
}
return 0;
}
/* find the biggest valid pfn in the range [start_pfn, end_pfn). */
static unsigned long find_biggest_section_pfn(int nid, struct zone *zone,
unsigned long start_pfn,
unsigned long end_pfn)
{
unsigned long pfn;
/* pfn is the end pfn of a memory section. */
pfn = end_pfn - 1;
for (; pfn >= start_pfn; pfn -= PAGES_PER_SUBSECTION) {
if (unlikely(!pfn_valid(pfn)))
continue;
if (unlikely(pfn_to_nid(pfn) != nid))
continue;
if (zone && zone != page_zone(pfn_to_page(pfn)))
continue;
return pfn;
}
return 0;
}
static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
unsigned long end_pfn)
{
unsigned long zone_start_pfn = zone->zone_start_pfn;
unsigned long z = zone_end_pfn(zone); /* zone_end_pfn namespace clash */
unsigned long zone_end_pfn = z;
unsigned long pfn;
int nid = zone_to_nid(zone);
zone_span_writelock(zone);
if (zone_start_pfn == start_pfn) {
/*
* If the section is smallest section in the zone, it need
* shrink zone->zone_start_pfn and zone->zone_spanned_pages.
* In this case, we find second smallest valid mem_section
* for shrinking zone.
*/
pfn = find_smallest_section_pfn(nid, zone, end_pfn,
zone_end_pfn);
if (pfn) {
zone->zone_start_pfn = pfn;
zone->spanned_pages = zone_end_pfn - pfn;
}
} else if (zone_end_pfn == end_pfn) {
/*
* If the section is biggest section in the zone, it need
* shrink zone->spanned_pages.
* In this case, we find second biggest valid mem_section for
* shrinking zone.
*/
pfn = find_biggest_section_pfn(nid, zone, zone_start_pfn,
start_pfn);
if (pfn)
zone->spanned_pages = pfn - zone_start_pfn + 1;
}
/*
* The section is not biggest or smallest mem_section in the zone, it
* only creates a hole in the zone. So in this case, we need not
* change the zone. But perhaps, the zone has only hole data. Thus
* it check the zone has only hole or not.
*/
pfn = zone_start_pfn;
for (; pfn < zone_end_pfn; pfn += PAGES_PER_SUBSECTION) {
if (unlikely(!pfn_valid(pfn)))
continue;
if (page_zone(pfn_to_page(pfn)) != zone)
continue;
/* Skip range to be removed */
if (pfn >= start_pfn && pfn < end_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;
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_SUBSECTION) {
if (unlikely(!pfn_valid(pfn)))
continue;
if (pfn_to_nid(pfn) != nid)
continue;
/* Skip range to be removed */
if (pfn >= start_pfn && pfn < end_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 void __remove_section(struct zone *zone, struct mem_section *ms,
unsigned long map_offset,
struct vmem_altmap *altmap)
{
unsigned long start_pfn;
int scn_nr;
if (WARN_ON_ONCE(!valid_section(ms)))
return;
scn_nr = __section_nr(ms);
start_pfn = section_nr_to_pfn((unsigned long)scn_nr);
__remove_zone(zone, start_pfn);
sparse_remove_one_section(ms, map_offset, altmap);
}
/**
* __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().
*/
void __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;
/* In the ZONE_DEVICE case device driver owns the memory region */
if (is_dev_zone(zone))
map_offset = vmem_altmap_offset(altmap);
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();
__remove_section(zone, __pfn_to_section(pfn), map_offset,
altmap);
map_offset = 0;
}
set_zone_contiguous(zone);
}
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, unsigned int order)
{
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
}
static int online_pages_blocks(unsigned long start, unsigned long nr_pages)
{
unsigned long end = start + nr_pages;
int order, onlined_pages = 0;
while (start < end) {
order = min(MAX_ORDER - 1,
get_order(PFN_PHYS(end) - PFN_PHYS(start)));
(*online_page_callback)(pfn_to_page(start), order);
onlined_pages += (1UL << order);
start += (1UL << order);
}
return onlined_pages;
}
static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
void *arg)
{
unsigned long onlined_pages = *(unsigned long *)arg;
if (PageReserved(pfn_to_page(start_pfn)))
onlined_pages += online_pages_blocks(start_pfn, nr_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);
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;
}
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);
}
/*
* Associates the given pfn range with the given node and the zone appropriate
* for the given online type.
*/
static struct zone * __meminit move_pfn_range(int online_type, int nid,
unsigned long start_pfn, unsigned long nr_pages)
{
struct zone *zone;
zone = zone_for_pfn_range(online_type, nid, start_pfn, nr_pages);
move_pfn_range_to_zone(zone, start_pfn, nr_pages, NULL);
return zone;
}
int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_type)
{
unsigned long flags;
unsigned long onlined_pages = 0;
struct zone *zone;
int need_zonelists_rebuild = 0;
int nid;
int ret;
struct memory_notify arg;
struct memory_block *mem;
mem_hotplug_begin();
/*
* We can't use pfn_to_nid() because nid might be stored in struct page
* which is not yet initialized. Instead, we find nid from memory block.
*/
mem = find_memory_block(__pfn_to_section(pfn));
nid = mem->nid;
put_device(&mem->dev);
/* associate pfn range with the zone */
zone = move_pfn_range(online_type, nid, pfn, nr_pages);
arg.start_pfn = pfn;
arg.nr_pages = nr_pages;
node_states_check_changes_online(nr_pages, zone, &arg);
ret = memory_notify(MEM_GOING_ONLINE, &arg);
ret = notifier_to_errno(ret);
if (ret)
goto failed_addition;
/*
* If this zone is not populated, then it is not in zonelist.
* This means the page allocator ignores this zone.
* So, zonelist must be updated after online.
*/
if (!populated_zone(zone)) {
need_zonelists_rebuild = 1;
setup_zone_pageset(zone);
}
ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages,
online_pages_range);
if (ret) {
if (need_zonelists_rebuild)
zone_pcp_reset(zone);
goto failed_addition;
}
zone->present_pages += onlined_pages;
pgdat_resize_lock(zone->zone_pgdat, &flags);
zone->zone_pgdat->node_present_pages += onlined_pages;
pgdat_resize_unlock(zone->zone_pgdat, &flags);
shuffle_zone(zone);
if (onlined_pages) {
node_states_set_node(nid, &arg);
if (need_zonelists_rebuild)
build_all_zonelists(NULL);
else
zone_pcp_update(zone);
}
init_per_zone_wmark_min();
if (onlined_pages) {
kswapd_run(nid);
kcompactd_run(nid);
}
vm_total_pages = nr_free_pagecache_pages();
writeback_set_ratelimit();
if (onlined_pages)
memory_notify(MEM_ONLINE, &arg);
mem_hotplug_done();
return 0;
failed_addition:
pr_debug("online_pages [mem %#010llx-%#010llx] failed\n",
(unsigned long long) pfn << PAGE_SHIFT,
(((unsigned long long) pfn + nr_pages) << PAGE_SHIFT) - 1);
memory_notify(MEM_CANCEL_ONLINE, &arg);
mem_hotplug_done();
return ret;
}
#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
static void reset_node_present_pages(pg_data_t *pgdat)
{
struct zone *z;
for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
z->present_pages = 0;
pgdat->node_present_pages = 0;
}
/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
{
struct pglist_data *pgdat;
unsigned long start_pfn = PFN_DOWN(start);
pgdat = NODE_DATA(nid);
if (!pgdat) {
pgdat = arch_alloc_nodedata(nid);
if (!pgdat)
return NULL;
arch_refresh_nodedata(nid, pgdat);
} else {
/*
* Reset the nr_zones, order and classzone_idx before reuse.
* Note that kswapd will init kswapd_classzone_idx properly
* when it starts in the near future.
*/
pgdat->nr_zones = 0;
pgdat->kswapd_order = 0;
pgdat->kswapd_classzone_idx = 0;
}
/* we can use NODE_DATA(nid) from here */
pgdat->node_id = nid;
pgdat->node_start_pfn = start_pfn;
/* init node's zones as empty zones, we don't have any present pages.*/
free_area_init_core_hotplug(nid);
pgdat->per_cpu_nodestats = alloc_percpu(struct per_cpu_nodestat);
/*
* The node we allocated has no zone fallback lists. For avoiding
* to access not-initialized zonelist, build here.
*/
build_all_zonelists(pgdat);
/*
* When memory is hot-added, all the memory is in offline state. So
* clear all zones' present_pages because they will be updated in
* online_pages() and offline_pages().
*/
reset_node_managed_pages(pgdat);
reset_node_present_pages(pgdat);
return pgdat;
}
static void rollback_node_hotadd(int nid)
{
pg_data_t *pgdat = NODE_DATA(nid);
arch_refresh_nodedata(nid, NULL);
free_percpu(pgdat->per_cpu_nodestats);
arch_free_nodedata(pgdat);
return;
}
/**
* try_online_node - online a node if offlined
* @nid: the node ID
* @start: start addr of the node
* @set_node_online: Whether we want to online the node
* called by cpu_up() to online a node without onlined memory.
*
* Returns:
* 1 -> a new node has been allocated
* 0 -> the node is already online
* -ENOMEM -> the node could not be allocated
*/
static int __try_online_node(int nid, u64 start, bool set_node_online)
{
pg_data_t *pgdat;
int ret = 1;
if (node_online(nid))
return 0;
pgdat = hotadd_new_pgdat(nid, start);
if (!pgdat) {
pr_err("Cannot online node %d due to NULL pgdat\n", nid);
ret = -ENOMEM;
goto out;
}
if (set_node_online) {
node_set_online(nid);
ret = register_one_node(nid);
BUG_ON(ret);
}
out:
return ret;
}
/*
* Users of this function always want to online/register the node
*/
int try_online_node(int nid)
{
int ret;
mem_hotplug_begin();
ret = __try_online_node(nid, 0, true);
mem_hotplug_done();
return ret;
}
static int check_hotplug_memory_range(u64 start, u64 size)
{
/* 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)
{
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_restrictions restrictions = {};
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, &restrictions);
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 */
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_auto_online)
walk_memory_blocks(start, size, NULL, online_memory_block);
return ret;
error:
/* rollback pgdat allocation and others */
if (new_node)
rollback_node_hotadd(nid);
memblock_remove(start, size);
mem_hotplug_done();
return ret;
}
/* requires device_hotplug_lock, see add_memory_resource() */
int __ref __add_memory(int nid, u64 start, u64 size)
{
struct resource *res;
int ret;
res = register_memory_resource(start, size);
if (IS_ERR(res))
return PTR_ERR(res);
ret = add_memory_resource(nid, res);
if (ret < 0)
release_memory_resource(res);
return ret;
}
int add_memory(int nid, u64 start, u64 size)
{
int rc;
lock_device_hotplug();
rc = __add_memory(nid, start, size);
unlock_device_hotplug();
return rc;
}
EXPORT_SYMBOL_GPL(add_memory);
#ifdef CONFIG_MEMORY_HOTREMOVE
/*
* A free page on the buddy free lists (not the per-cpu lists) has PageBuddy
* set and the size of the free page is given by page_order(). Using this,
* the function determines if the pageblock contains only free pages.
* Due to buddy contraints, a free page at least the size of a pageblock will
* be located at the start of the pageblock
*/
static inline int pageblock_free(struct page *page)
{
return PageBuddy(page) && page_order(page) >= pageblock_order;
}
/* Return the pfn of the start of the next active pageblock after a given pfn */
static unsigned long next_active_pageblock(unsigned long pfn)
{
struct page *page = pfn_to_page(pfn);
/* Ensure the starting page is pageblock-aligned */
BUG_ON(pfn & (pageblock_nr_pages - 1));
/* If the entire pageblock is free, move to the end of free page */
if (pageblock_free(page)) {
int order;
/* be careful. we don't have locks, page_order can be changed.*/
order = page_order(page);
if ((order < MAX_ORDER) && (order >= pageblock_order))
return pfn + (1 << order);
}
return pfn + pageblock_nr_pages;
}
static bool is_pageblock_removable_nolock(unsigned long pfn)
{
struct page *page = pfn_to_page(pfn);
struct zone *zone;
/*
* We have to be careful here because we are iterating over memory
* sections which are not zone aware so we might end up outside of
* the zone but still within the section.
* We have to take care about the node as well. If the node is offline
* its NODE_DATA will be NULL - see page_zone.
*/
if (!node_online(page_to_nid(page)))
return false;
zone = page_zone(page);
pfn = page_to_pfn(page);
if (!zone_spans_pfn(zone, pfn))
return false;
return !has_unmovable_pages(zone, page, 0, MIGRATE_MOVABLE, SKIP_HWPOISON);
}
/* Checks if this range of memory is likely to be hot-removable. */
bool is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages)
{
unsigned long end_pfn, pfn;
end_pfn = min(start_pfn + nr_pages,
zone_end_pfn(page_zone(pfn_to_page(start_pfn))));
/* Check the starting page of each pageblock within the range */
for (pfn = start_pfn; pfn < end_pfn; pfn = next_active_pageblock(pfn)) {
if (!is_pageblock_removable_nolock(pfn))
return false;
cond_resched();
}
/* All pageblocks in the memory block are likely to be hot-removable */
return true;
}
/*
* Confirm all pages in a range [start, end) belong to the same zone.
* When true, return its valid [start, end).
*/
int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn,
unsigned long *valid_start, unsigned long *valid_end)
{
unsigned long pfn, sec_end_pfn;
unsigned long start, end;
struct zone *zone = NULL;
struct page *page;
int i;
for (pfn = start_pfn, sec_end_pfn = SECTION_ALIGN_UP(start_pfn + 1);
pfn < end_pfn;
pfn = sec_end_pfn, sec_end_pfn += PAGES_PER_SECTION) {
/* Make sure the memory section is present first */
if (!present_section_nr(pfn_to_section_nr(pfn)))
continue;
for (; pfn < sec_end_pfn && pfn < end_pfn;
pfn += MAX_ORDER_NR_PAGES) {
i = 0;
/* This is just a CONFIG_HOLES_IN_ZONE check.*/
while ((i < MAX_ORDER_NR_PAGES) &&
!pfn_valid_within(pfn + i))
i++;
if (i == MAX_ORDER_NR_PAGES || pfn + i >= end_pfn)
continue;
/* Check if we got outside of the zone */
if (zone && !zone_spans_pfn(zone, pfn + i))
return 0;
page = pfn_to_page(pfn + i);
if (zone && page_zone(page) != zone)
return 0;
if (!zone)
start = pfn + i;
zone = page_zone(page);
end = pfn + MAX_ORDER_NR_PAGES;
}
}
if (zone) {
*valid_start = start;
*valid_end = min(end, end_pfn);
return 1;
} else {
return 0;
}
}
/*
* Scan pfn range [start,end) to find movable/migratable pages (LRU pages,
* non-lru movable pages and hugepages). We scan pfn because it's much
* easier than scanning over linked list. This function returns the pfn
* of the first found movable page if it's found, otherwise 0.
*/
static unsigned long scan_movable_pages(unsigned long start, unsigned long end)
{
unsigned long pfn;
for (pfn = start; pfn < end; pfn++) {
struct page *page, *head;
unsigned long skip;
if (!pfn_valid(pfn))
continue;
page = pfn_to_page(pfn);
if (PageLRU(page))
return pfn;
if (__PageMovable(page))
return pfn;
if (!PageHuge(page))
continue;
head = compound_head(page);
if (page_huge_active(head))
return pfn;
skip = (1 << compound_order(head)) - (page - head);
pfn += skip - 1;
}
return 0;
}
static struct page *new_node_page(struct page *page, unsigned long private)
{
int nid = page_to_nid(page);
nodemask_t nmask = node_states[N_MEMORY];
/*
* try to allocate from a different node but reuse this node if there
* are no other online nodes to be used (e.g. we are offlining a part
* of the only existing node)
*/
node_clear(nid, nmask);
if (nodes_empty(nmask))
node_set(nid, nmask);
return new_page_nodemask(page, nid, &nmask);
}
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) + (1<<compound_order(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_cache(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;
}
/*
* remove from free_area[] and mark all as Reserved.
*/
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, recoreded 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, true);
}
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;
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 __ref __offline_pages(unsigned long start_pfn,
unsigned long end_pfn)
{
unsigned long pfn, nr_pages;
unsigned long offlined_pages = 0;
int ret, node, nr_isolate_pageblock;
unsigned long flags;
unsigned long valid_start, valid_end;
struct zone *zone;
struct memory_notify arg;
char *reason;
mem_hotplug_begin();
/* This makes hotplug much easier...and readable.
we assume this for now. .*/
if (!test_pages_in_a_zone(start_pfn, end_pfn, &valid_start,
&valid_end)) {
ret = -EINVAL;
reason = "multizone range";
goto failed_removal;
}
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,
SKIP_HWPOISON | 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);
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 = 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 -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;
}
/**
* 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_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));
mem_hotplug_begin();
/*
* 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");
memblock_free(start, size);
memblock_remove(start, size);
/* remove memory block devices before removing memory */
remove_memory_block_devices(start, size);
arch_remove_memory(nid, start, size, NULL);
__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() is 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 */