/*
* linux/mm/memory_hotplug.c
*
* Copyright (C)
*/
#include <linux/stddef.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/interrupt.h>
#include <linux/pagemap.h>
#include <linux/compiler.h>
#include <linux/export.h>
#include <linux/pagevec.h>
#include <linux/writeback.h>
#include <linux/slab.h>
#include <linux/sysctl.h>
#include <linux/cpu.h>
#include <linux/memory.h>
#include <linux/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);
/* The same as the cpu_hotplug lock, but for memory hotplug. */
static struct {
struct task_struct *active_writer;
struct mutex lock; /* Synchronizes accesses to refcount, */
/*
* Also blocks the new readers during
* an ongoing mem hotplug operation.
*/
int refcount;
#ifdef [31mCONFIG_DEBUG_LOCK_ALLOC[0m
struct lockdep_map dep_map;
#endif
} mem_hotplug = {
.active_writer = NULL,
.lock = __MUTEX_INITIALIZER(mem_hotplug.lock),
.refcount = 0,
#ifdef [31mCONFIG_DEBUG_LOCK_ALLOC[0m
.dep_map = {.name = "mem_hotplug.lock" },
#endif
};
/* Lockdep annotations for get/put_online_mems() and mem_hotplug_begin/end() */
#define memhp_lock_acquire_read() lock_map_acquire_read(&mem_hotplug.dep_map)
#define memhp_lock_acquire() lock_map_acquire(&mem_hotplug.dep_map)
#define memhp_lock_release() lock_map_release(&mem_hotplug.dep_map)
#ifndef [31mCONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE[0m
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 get_online_mems(void)
{
might_sleep();
if (mem_hotplug.active_writer == current)
return;
memhp_lock_acquire_read();
mutex_lock(&mem_hotplug.lock);
mem_hotplug.refcount++;
mutex_unlock(&mem_hotplug.lock);
}
void put_online_mems(void)
{
if (mem_hotplug.active_writer == current)
return;
mutex_lock(&mem_hotplug.lock);
if (WARN_ON(!mem_hotplug.refcount))
mem_hotplug.refcount++; /* try to fix things up */
if (!--mem_hotplug.refcount && unlikely(mem_hotplug.active_writer))
wake_up_process(mem_hotplug.active_writer);
mutex_unlock(&mem_hotplug.lock);
memhp_lock_release();
}
void mem_hotplug_begin(void)
{
mem_hotplug.active_writer = current;
memhp_lock_acquire();
for (;;) {
mutex_lock(&mem_hotplug.lock);
if (likely(!mem_hotplug.refcount))
break;
__set_current_state(TASK_UNINTERRUPTIBLE);
mutex_unlock(&mem_hotplug.lock);
schedule();
}
}
void mem_hotplug_done(void)
{
mem_hotplug.active_writer = NULL;
mutex_unlock(&mem_hotplug.lock);
memhp_lock_release();
}
/* add this memory to iomem resource */
static struct resource *register_memory_resource(u64 start, u64 size)
{
struct resource *res;
res = kzalloc(sizeof(struct resource), GFP_KERNEL);
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;
if (request_resource(&iomem_resource, res) < 0) {
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 [31mCONFIG_MEMORY_HOTPLUG_SPARSE[0m
void get_page_bootmem(unsigned long info, struct page *page,
unsigned long type)
{
page->lru.next = (struct list_head *) type;
SetPagePrivate(page);
set_page_private(page, info);
page_ref_inc(page);
}
void put_page_bootmem(struct page *page)
{
unsigned long type;
type = (unsigned long) page->lru.next;
BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE);
if (page_ref_dec_return(page) == 1) {
ClearPagePrivate(page);
set_page_private(page, 0);
INIT_LIST_HEAD(&page->lru);
free_reserved_page(page);
}
}
#ifdef [31mCONFIG_HAVE_BOOTMEM_INFO_NODE[0m
#ifndef [31mCONFIG_SPARSEMEM_VMEMMAP[0m
static void register_page_bootmem_info_section(unsigned long start_pfn)
{
unsigned long *usemap, mapsize, section_nr, i;
struct mem_section *ms;
struct page *page, *memmap;
section_nr = pfn_to_section_nr(start_pfn);
ms = __nr_to_section(section_nr);
/* Get section's memmap address */
memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
/*
* Get page for the memmap's phys address
* XXX: need more consideration for sparse_vmemmap...
*/
page = virt_to_page(memmap);
mapsize = sizeof(struct page) * PAGES_PER_SECTION;
mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT;
/* remember memmap's page */
for (i = 0; i < mapsize; i++, page++)
get_page_bootmem(section_nr, page, SECTION_INFO);
usemap = __nr_to_section(section_nr)->pageblock_flags;
page = virt_to_page(usemap);
mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT;
for (i = 0; i < mapsize; i++, page++)
get_page_bootmem(section_nr, page, MIX_SECTION_INFO);
}
#else /* CONFIG_SPARSEMEM_VMEMMAP */
static void register_page_bootmem_info_section(unsigned long start_pfn)
{
unsigned long *usemap, mapsize, section_nr, i;
struct mem_section *ms;
struct page *page, *memmap;
if (!pfn_valid(start_pfn))
return;
section_nr = pfn_to_section_nr(start_pfn);
ms = __nr_to_section(section_nr);
memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
register_page_bootmem_memmap(section_nr, memmap, PAGES_PER_SECTION);
usemap = __nr_to_section(section_nr)->pageblock_flags;
page = virt_to_page(usemap);
mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT;
for (i = 0; i < mapsize; i++, page++)
get_page_bootmem(section_nr, page, MIX_SECTION_INFO);
}
#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
void __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 void __meminit grow_zone_span(struct zone *zone, unsigned long start_pfn,
unsigned long end_pfn)
{
unsigned long old_zone_end_pfn;
zone_span_writelock(zone);
old_zone_end_pfn = zone_end_pfn(zone);
if (zone_is_empty(zone) || start_pfn < zone->zone_start_pfn)
zone->zone_start_pfn = start_pfn;
zone->spanned_pages = max(old_zone_end_pfn, end_pfn) -
zone->zone_start_pfn;
zone_span_writeunlock(zone);
}
static void resize_zone(struct zone *zone, unsigned long start_pfn,
unsigned long end_pfn)
{
zone_span_writelock(zone);
if (end_pfn - start_pfn) {
zone->zone_start_pfn = start_pfn;
zone->spanned_pages = end_pfn - start_pfn;
} else {
/*
* make it consist as free_area_init_core(),
* if spanned_pages = 0, then keep start_pfn = 0
*/
zone->zone_start_pfn = 0;
zone->spanned_pages = 0;
}
zone_span_writeunlock(zone);
}
static void fix_zone_id(struct zone *zone, unsigned long start_pfn,
unsigned long end_pfn)
{
enum zone_type zid = zone_idx(zone);
int nid = zone->zone_pgdat->node_id;
unsigned long pfn;
for (pfn = start_pfn; pfn < end_pfn; pfn++)
set_page_links(pfn_to_page(pfn), zid, nid, pfn);
}
/* Can fail with -ENOMEM from allocating a wait table with vmalloc() or
* alloc_bootmem_node_nopanic()/memblock_virt_alloc_node_nopanic() */
static int __ref ensure_zone_is_initialized(struct zone *zone,
unsigned long start_pfn, unsigned long num_pages)
{
if (!zone_is_initialized(zone))
return init_currently_empty_zone(zone, start_pfn, num_pages);
return 0;
}
static int __meminit move_pfn_range_left(struct zone *z1, struct zone *z2,
unsigned long start_pfn, unsigned long end_pfn)
{
int ret;
unsigned long flags;
unsigned long z1_start_pfn;
ret = ensure_zone_is_initialized(z1, start_pfn, end_pfn - start_pfn);
if (ret)
return ret;
pgdat_resize_lock(z1->zone_pgdat, &flags);
/* can't move pfns which are higher than @z2 */
if (end_pfn > zone_end_pfn(z2))
goto out_fail;
/* the move out part must be at the left most of @z2 */
if (start_pfn > z2->zone_start_pfn)
goto out_fail;
/* must included/overlap */
if (end_pfn <= z2->zone_start_pfn)
goto out_fail;
/* use start_pfn for z1's start_pfn if z1 is empty */
if (!zone_is_empty(z1))
z1_start_pfn = z1->zone_start_pfn;
else
z1_start_pfn = start_pfn;
resize_zone(z1, z1_start_pfn, end_pfn);
resize_zone(z2, end_pfn, zone_end_pfn(z2));
pgdat_resize_unlock(z1->zone_pgdat, &flags);
fix_zone_id(z1, start_pfn, end_pfn);
return 0;
out_fail:
pgdat_resize_unlock(z1->zone_pgdat, &flags);
return -1;
}
static int __meminit move_pfn_range_right(struct zone *z1, struct zone *z2,
unsigned long start_pfn, unsigned long end_pfn)
{
int ret;
unsigned long flags;
unsigned long z2_end_pfn;
ret = ensure_zone_is_initialized(z2, start_pfn, end_pfn - start_pfn);
if (ret)
return ret;
pgdat_resize_lock(z1->zone_pgdat, &flags);
/* can't move pfns which are lower than @z1 */
if (z1->zone_start_pfn > start_pfn)
goto out_fail;
/* the move out part mast at the right most of @z1 */
if (zone_end_pfn(z1) > end_pfn)
goto out_fail;
/* must included/overlap */
if (start_pfn >= zone_end_pfn(z1))
goto out_fail;
/* use end_pfn for z2's end_pfn if z2 is empty */
if (!zone_is_empty(z2))
z2_end_pfn = zone_end_pfn(z2);
else
z2_end_pfn = end_pfn;
resize_zone(z1, z1->zone_start_pfn, start_pfn);
resize_zone(z2, start_pfn, z2_end_pfn);
pgdat_resize_unlock(z1->zone_pgdat, &flags);
fix_zone_id(z2, start_pfn, end_pfn);
return 0;
out_fail:
pgdat_resize_unlock(z1->zone_pgdat, &flags);
return -1;
}
static struct zone * __meminit move_pfn_range(int zone_shift,
unsigned long start_pfn, unsigned long end_pfn)
{
struct zone *zone = page_zone(pfn_to_page(start_pfn));
int ret = 0;
if (zone_shift < 0)
ret = move_pfn_range_left(zone + zone_shift, zone,
start_pfn, end_pfn);
else if (zone_shift)
ret = move_pfn_range_right(zone, zone + zone_shift,
start_pfn, end_pfn);
if (ret)
return NULL;
return zone + zone_shift;
}
static void __meminit grow_pgdat_span(struct pglist_data *pgdat, unsigned long start_pfn,
unsigned long end_pfn)
{
unsigned long old_pgdat_end_pfn = pgdat_end_pfn(pgdat);
if (!pgdat->node_spanned_pages || start_pfn < pgdat->node_start_pfn)
pgdat->node_start_pfn = start_pfn;
pgdat->node_spanned_pages = max(old_pgdat_end_pfn, end_pfn) -
pgdat->node_start_pfn;
}
static int __meminit __add_zone(struct zone *zone, unsigned long phys_start_pfn)
{
struct pglist_data *pgdat = zone->zone_pgdat;
int nr_pages = PAGES_PER_SECTION;
int nid = pgdat->node_id;
int zone_type;
unsigned long flags, pfn;
int ret;
zone_type = zone - pgdat->node_zones;
ret = ensure_zone_is_initialized(zone, phys_start_pfn, nr_pages);
if (ret)
return ret;
pgdat_resize_lock(zone->zone_pgdat, &flags);
grow_zone_span(zone, phys_start_pfn, phys_start_pfn + nr_pages);
grow_pgdat_span(zone->zone_pgdat, phys_start_pfn,
phys_start_pfn + nr_pages);
pgdat_resize_unlock(zone->zone_pgdat, &flags);
memmap_init_zone(nr_pages, nid, zone_type,
phys_start_pfn, MEMMAP_HOTPLUG);
/* online_page_range is called later and expects pages reserved */
for (pfn = phys_start_pfn; pfn < phys_start_pfn + nr_pages; pfn++) {
if (!pfn_valid(pfn))
continue;
SetPageReserved(pfn_to_page(pfn));
}
return 0;
}
static int __meminit __add_section(int nid, struct zone *zone,
unsigned long phys_start_pfn)
{
int ret;
if (pfn_valid(phys_start_pfn))
return -EEXIST;
ret = sparse_add_one_section(zone, phys_start_pfn);
if (ret < 0)
return ret;
ret = __add_zone(zone, phys_start_pfn);
if (ret < 0)
return ret;
return register_new_memory(nid, __pfn_to_section(phys_start_pfn));
}
/*
* Reasonably generic function for adding memory. It is
* expected that archs that support memory hotplug will
* call this function after deciding the zone to which to
* add the new pages.
*/
int __ref __add_pages(int nid, struct zone *zone, unsigned long phys_start_pfn,
unsigned long nr_pages)
{
unsigned long i;
int err = 0;
int start_sec, end_sec;
struct vmem_altmap *altmap;
clear_zone_contiguous(zone);
/* 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);
altmap = to_vmem_altmap((unsigned long) pfn_to_page(phys_start_pfn));
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, zone, section_nr_to_pfn(i));
/*
* EEXIST is finally dealt with by ioresource collision
* check. see add_memory() => register_memory_resource()
* Warning will be printed if there is collision.
*/
if (err && (err != -EEXIST))
break;
err = 0;
}
vmemmap_populate_print_last();
out:
set_zone_contiguous(zone);
return err;
}
EXPORT_SYMBOL_GPL(__add_pages);
#ifdef [31mCONFIG_MEMORY_HOTREMOVE[0m
/* find the smallest valid pfn in the range [start_pfn, end_pfn) */
static int find_smallest_section_pfn(int nid, struct zone *zone,
unsigned long start_pfn,
unsigned long end_pfn)
{
struct mem_section *ms;
for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SECTION) {
ms = __pfn_to_section(start_pfn);
if (unlikely(!valid_section(ms)))
continue;
if (unlikely(pfn_to_nid(start_pfn) != nid))
continue;
if (zone && zone != page_zone(pfn_to_page(start_pfn)))
continue;
return start_pfn;
}
return 0;
}
/* find the biggest valid pfn in the range [start_pfn, end_pfn). */
static int find_biggest_section_pfn(int nid, struct zone *zone,
unsigned long start_pfn,
unsigned long end_pfn)
{
struct mem_section *ms;
unsigned long pfn;
/* pfn is the end pfn of a memory section. */
pfn = end_pfn - 1;
for (; pfn >= start_pfn; pfn -= PAGES_PER_SECTION) {
ms = __pfn_to_section(pfn);
if (unlikely(!valid_section(ms)))
continue;
if (unlikely(pfn_to_nid(pfn) != nid))
continue;
if (zone && zone != page_zone(pfn_to_page(pfn)))
continue;
return pfn;
}
return 0;
}
static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
unsigned long end_pfn)
{
unsigned long zone_start_pfn = zone->zone_start_pfn;
unsigned long z = zone_end_pfn(zone); /* zone_end_pfn namespace clash */
unsigned long zone_end_pfn = z;
unsigned long pfn;
struct mem_section *ms;
int nid = zone_to_nid(zone);
zone_span_writelock(zone);
if (zone_start_pfn == start_pfn) {
/*
* If the section is smallest section in the zone, it need
* shrink zone->zone_start_pfn and zone->zone_spanned_pages.
* In this case, we find second smallest valid mem_section
* for shrinking zone.
*/
pfn = find_smallest_section_pfn(nid, zone, end_pfn,
zone_end_pfn);
if (pfn) {
zone->zone_start_pfn = pfn;
zone->spanned_pages = zone_end_pfn - pfn;
}
} else if (zone_end_pfn == end_pfn) {
/*
* If the section is biggest section in the zone, it need
* shrink zone->spanned_pages.
* In this case, we find second biggest valid mem_section for
* shrinking zone.
*/
pfn = find_biggest_section_pfn(nid, zone, zone_start_pfn,
start_pfn);
if (pfn)
zone->spanned_pages = pfn - zone_start_pfn + 1;
}
/*
* The section is not biggest or smallest mem_section in the zone, it
* only creates a hole in the zone. So in this case, we need not
* change the zone. But perhaps, the zone has only hole data. Thus
* it check the zone has only hole or not.
*/
pfn = zone_start_pfn;
for (; pfn < zone_end_pfn; pfn += PAGES_PER_SECTION) {
ms = __pfn_to_section(pfn);
if (unlikely(!valid_section(ms)))
continue;
if (page_zone(pfn_to_page(pfn)) != zone)
continue;
/* If the section is current section, it continues the loop */
if (start_pfn == pfn)
continue;
/* If we find valid section, we have nothing to do */
zone_span_writeunlock(zone);
return;
}
/* The zone has no valid section */
zone->zone_start_pfn = 0;
zone->spanned_pages = 0;
zone_span_writeunlock(zone);
}
static void shrink_pgdat_span(struct pglist_data *pgdat,
unsigned long start_pfn, unsigned long end_pfn)
{
unsigned long pgdat_start_pfn = pgdat->node_start_pfn;
unsigned long p = pgdat_end_pfn(pgdat); /* pgdat_end_pfn namespace clash */
unsigned long pgdat_end_pfn = p;
unsigned long pfn;
struct mem_section *ms;
int nid = pgdat->node_id;
if (pgdat_start_pfn == start_pfn) {
/*
* If the section is smallest section in the pgdat, it need
* shrink pgdat->node_start_pfn and pgdat->node_spanned_pages.
* In this case, we find second smallest valid mem_section
* for shrinking zone.
*/
pfn = find_smallest_section_pfn(nid, NULL, end_pfn,
pgdat_end_pfn);
if (pfn) {
pgdat->node_start_pfn = pfn;
pgdat->node_spanned_pages = pgdat_end_pfn - pfn;
}
} else if (pgdat_end_pfn == end_pfn) {
/*
* If the section is biggest section in the pgdat, it need
* shrink pgdat->node_spanned_pages.
* In this case, we find second biggest valid mem_section for
* shrinking zone.
*/
pfn = find_biggest_section_pfn(nid, NULL, pgdat_start_pfn,
start_pfn);
if (pfn)
pgdat->node_spanned_pages = pfn - pgdat_start_pfn + 1;
}
/*
* If the section is not biggest or smallest mem_section in the pgdat,
* it only creates a hole in the pgdat. So in this case, we need not
* change the pgdat.
* But perhaps, the pgdat has only hole data. Thus it check the pgdat
* has only hole or not.
*/
pfn = pgdat_start_pfn;
for (; pfn < pgdat_end_pfn; pfn += PAGES_PER_SECTION) {
ms = __pfn_to_section(pfn);
if (unlikely(!valid_section(ms)))
continue;
if (pfn_to_nid(pfn) != nid)
continue;
/* If the section is current section, it continues the loop */
if (start_pfn == pfn)
continue;
/* If we find valid section, we have nothing to do */
return;
}
/* The pgdat has no valid section */
pgdat->node_start_pfn = 0;
pgdat->node_spanned_pages = 0;
}
static void __remove_zone(struct zone *zone, unsigned long start_pfn)
{
struct pglist_data *pgdat = zone->zone_pgdat;
int nr_pages = PAGES_PER_SECTION;
int zone_type;
unsigned long flags;
zone_type = zone - pgdat->node_zones;
pgdat_resize_lock(zone->zone_pgdat, &flags);
shrink_zone_span(zone, start_pfn, start_pfn + nr_pages);
shrink_pgdat_span(pgdat, start_pfn, start_pfn + nr_pages);
pgdat_resize_unlock(zone->zone_pgdat, &flags);
}
static int __remove_section(struct zone *zone, struct mem_section *ms,
unsigned long map_offset)
{
unsigned long start_pfn;
int scn_nr;
int ret = -EINVAL;
if (!valid_section(ms))
return ret;
ret = unregister_memory_section(ms);
if (ret)
return ret;
scn_nr = __section_nr(ms);
start_pfn = section_nr_to_pfn(scn_nr);
__remove_zone(zone, start_pfn);
sparse_remove_one_section(zone, ms, map_offset);
return 0;
}
/**
* __remove_pages() - remove sections of pages from a zone
* @zone: zone from which pages need to be removed
* @phys_start_pfn: starting pageframe (must be aligned to start of a section)
* @nr_pages: number of pages to remove (must be multiple of section size)
*
* Generic helper function to remove section mappings and sysfs entries
* for the section of the memory we are removing. Caller needs to make
* sure that pages are marked reserved and zones are adjust properly by
* calling offline_pages().
*/
int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
unsigned long nr_pages)
{
unsigned long i;
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)) {
struct page *page = pfn_to_page(phys_start_pfn);
struct vmem_altmap *altmap;
altmap = to_vmem_altmap((unsigned long) page);
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;
ret = __remove_section(zone, __pfn_to_section(pfn), map_offset);
map_offset = 0;
if (ret)
break;
}
set_zone_contiguous(zone);
return ret;
}
EXPORT_SYMBOL_GPL(__remove_pages);
#endif /* CONFIG_MEMORY_HOTREMOVE */
int set_online_page_callback(online_page_callback_t callback)
{
int rc = -EINVAL;
get_online_mems();
mutex_lock(&online_page_callback_lock);
if (online_page_callback == generic_online_page) {
online_page_callback = callback;
rc = 0;
}
mutex_unlock(&online_page_callback_lock);
put_online_mems();
return rc;
}
EXPORT_SYMBOL_GPL(set_online_page_callback);
int restore_online_page_callback(online_page_callback_t callback)
{
int rc = -EINVAL;
get_online_mems();
mutex_lock(&online_page_callback_lock);
if (online_page_callback == callback) {
online_page_callback = generic_online_page;
rc = 0;
}
mutex_unlock(&online_page_callback_lock);
put_online_mems();
return rc;
}
EXPORT_SYMBOL_GPL(restore_online_page_callback);
void __online_page_set_limits(struct page *page)
{
}
EXPORT_SYMBOL_GPL(__online_page_set_limits);
void __online_page_increment_counters(struct page *page)
{
adjust_managed_page_count(page, 1);
}
EXPORT_SYMBOL_GPL(__online_page_increment_counters);
void __online_page_free(struct page *page)
{
__free_reserved_page(page);
}
EXPORT_SYMBOL_GPL(__online_page_free);
static void generic_online_page(struct page *page)
{
__online_page_set_limits(page);
__online_page_increment_counters(page);
__online_page_free(page);
}
static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
void *arg)
{
unsigned long i;
unsigned long onlined_pages = *(unsigned long *)arg;
struct page *page;
if (PageReserved(pfn_to_page(start_pfn)))
for (i = 0; i < nr_pages; i++) {
page = pfn_to_page(start_pfn + i);
(*online_page_callback)(page);
onlined_pages++;
}
*(unsigned long *)arg = onlined_pages;
return 0;
}
#ifdef [31mCONFIG_MOVABLE_NODE[0m
/*
* When CONFIG_MOVABLE_NODE, we permit onlining of a node which doesn't have
* normal memory.
*/
static bool can_online_high_movable(struct zone *zone)
{
return true;
}
#else /* CONFIG_MOVABLE_NODE */
/* ensure every online node has NORMAL memory */
static bool can_online_high_movable(struct zone *zone)
{
return node_state(zone_to_nid(zone), N_NORMAL_MEMORY);
}
#endif /* CONFIG_MOVABLE_NODE */
/* check which state of node_states will be changed when online memory */
static void node_states_check_changes_online(unsigned long nr_pages,
struct zone *zone, struct memory_notify *arg)
{
int nid = zone_to_nid(zone);
enum zone_type zone_last = ZONE_NORMAL;
/*
* If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY]
* contains nodes which have zones of 0...ZONE_NORMAL,
* set zone_last to ZONE_NORMAL.
*
* If we don't have HIGHMEM nor movable node,
* node_states[N_NORMAL_MEMORY] contains nodes which have zones of
* 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE.
*/
if (N_MEMORY == N_NORMAL_MEMORY)
zone_last = ZONE_MOVABLE;
/*
* if the memory to be online is in a zone of 0...zone_last, and
* the zones of 0...zone_last don't have memory before online, we will
* need to set the node to node_states[N_NORMAL_MEMORY] after
* the memory is online.
*/
if (zone_idx(zone) <= zone_last && !node_state(nid, N_NORMAL_MEMORY))
arg->status_change_nid_normal = nid;
else
arg->status_change_nid_normal = -1;
#ifdef [31mCONFIG_HIGHMEM[0m
/*
* 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);
}
bool zone_can_shift(unsigned long pfn, unsigned long nr_pages,
enum zone_type target, int *zone_shift)
{
struct zone *zone = page_zone(pfn_to_page(pfn));
enum zone_type idx = zone_idx(zone);
int i;
*zone_shift = 0;
if (idx < target) {
/* pages must be at end of current zone */
if (pfn + nr_pages != zone_end_pfn(zone))
return false;
/* no zones in use between current zone and target */
for (i = idx + 1; i < target; i++)
if (zone_is_initialized(zone - idx + i))
return false;
}
if (target < idx) {
/* pages must be at beginning of current zone */
if (pfn != zone->zone_start_pfn)
return false;
/* no zones in use between current zone and target */
for (i = target + 1; i < idx; i++)
if (zone_is_initialized(zone - idx + i))
return false;
}
*zone_shift = target - idx;
return true;
}
/* Must be protected by mem_hotplug_begin() */
int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_type)
{
unsigned long flags;
unsigned long onlined_pages = 0;
struct zone *zone;
int need_zonelists_rebuild = 0;
int nid;
int ret;
struct memory_notify arg;
int zone_shift = 0;
/*
* This doesn't need a lock to do pfn_to_page().
* The section can't be removed here because of the
* memory_block->state_mutex.
*/
zone = page_zone(pfn_to_page(pfn));
if ((zone_idx(zone) > ZONE_NORMAL ||
online_type == MMOP_ONLINE_MOVABLE) &&
!can_online_high_movable(zone))
return -EINVAL;
if (online_type == MMOP_ONLINE_KERNEL) {
if (!zone_can_shift(pfn, nr_pages, ZONE_NORMAL, &zone_shift))
return -EINVAL;
} else if (online_type == MMOP_ONLINE_MOVABLE) {
if (!zone_can_shift(pfn, nr_pages, ZONE_MOVABLE, &zone_shift))
return -EINVAL;
}
zone = move_pfn_range(zone_shift, pfn, pfn + nr_pages);
if (!zone)
return -EINVAL;
arg.start_pfn = pfn;
arg.nr_pages = nr_pages;
node_states_check_changes_online(nr_pages, zone, &arg);
nid = zone_to_nid(zone);
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.
*/
mutex_lock(&zonelists_mutex);
if (!populated_zone(zone)) {
need_zonelists_rebuild = 1;
build_all_zonelists(NULL, zone);
}
ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages,
online_pages_range);
if (ret) {
if (need_zonelists_rebuild)
zone_pcp_reset(zone);
mutex_unlock(&zonelists_mutex);
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, NULL);
else
zone_pcp_update(zone);
}
mutex_unlock(&zonelists_mutex);
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 zones_size[MAX_NR_ZONES] = {0};
unsigned long zholes_size[MAX_NR_ZONES] = {0};
unsigned long start_pfn = PFN_DOWN(start);
pgdat = NODE_DATA(nid);
if (!pgdat) {
pgdat = arch_alloc_nodedata(nid);
if (!pgdat)
return NULL;
arch_refresh_nodedata(nid, pgdat);
} else {
/* Reset the nr_zones, order and classzone_idx before reuse */
pgdat->nr_zones = 0;
pgdat->kswapd_order = 0;
pgdat->kswapd_classzone_idx = 0;
}
/* we can use NODE_DATA(nid) from here */
/* init node's zones as empty zones, we don't have any present pages.*/
free_area_init_node(nid, zones_size, start_pfn, zholes_size);
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.
*/
mutex_lock(&zonelists_mutex);
build_all_zonelists(pgdat, NULL);
mutex_unlock(&zonelists_mutex);
/*
* zone->managed_pages is set to an approximate value in
* free_area_init_core(), which will cause
* /sys/device/system/node/nodeX/meminfo has wrong data.
* So reset it to 0 before any memory is onlined.
*/
reset_node_managed_pages(pgdat);
/*
* When memory is hot-added, all the memory is in offline state. So
* clear all zones' present_pages because they will be updated in
* online_pages() and offline_pages().
*/
reset_node_present_pages(pgdat);
return pgdat;
}
static void rollback_node_hotadd(int nid, pg_data_t *pgdat)
{
arch_refresh_nodedata(nid, NULL);
free_percpu(pgdat->per_cpu_nodestats);
arch_free_nodedata(pgdat);
return;
}
/**
* try_online_node - online a node if offlined
*
* called by cpu_up() to online a node without onlined memory.
*/
int try_online_node(int nid)
{
pg_data_t *pgdat;
int ret;
if (node_online(nid))
return 0;
mem_hotplug_begin();
pgdat = hotadd_new_pgdat(nid, 0);
if (!pgdat) {
pr_err("Cannot online node %d due to NULL pgdat\n", nid);
ret = -ENOMEM;
goto out;
}
node_set_online(nid);
ret = register_one_node(nid);
BUG_ON(ret);
if (pgdat->node_zonelists->_zonerefs->zone == NULL) {
mutex_lock(&zonelists_mutex);
build_all_zonelists(NULL, NULL);
mutex_unlock(&zonelists_mutex);
}
out:
mem_hotplug_done();
return ret;
}
static int check_hotplug_memory_range(u64 start, u64 size)
{
u64 start_pfn = PFN_DOWN(start);
u64 nr_pages = size >> PAGE_SHIFT;
/* Memory range must be aligned with section */
if ((start_pfn & ~PAGE_SECTION_MASK) ||
(nr_pages % PAGES_PER_SECTION) || (!nr_pages)) {
pr_err("Section-unaligned hotplug range: start 0x%llx, size 0x%llx\n",
(unsigned long long)start,
(unsigned long long)size);
return -EINVAL;
}
return 0;
}
/*
* If movable zone has already been setup, newly added memory should be check.
* If its address is higher than movable zone, it should be added as movable.
* Without this check, movable zone may overlap with other zone.
*/
static int should_add_memory_movable(int nid, u64 start, u64 size)
{
unsigned long start_pfn = start >> PAGE_SHIFT;
pg_data_t *pgdat = NODE_DATA(nid);
struct zone *movable_zone = pgdat->node_zones + ZONE_MOVABLE;
if (zone_is_empty(movable_zone))
return 0;
if (movable_zone->zone_start_pfn <= start_pfn)
return 1;
return 0;
}
int zone_for_memory(int nid, u64 start, u64 size, int zone_default,
bool for_device)
{
#ifdef [31mCONFIG_ZONE_DEVICE[0m
if (for_device)
return ZONE_DEVICE;
#endif
if (should_add_memory_movable(nid, start, size))
return ZONE_MOVABLE;
return zone_default;
}
static int online_memory_block(struct memory_block *mem, void *arg)
{
return memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE);
}
/* 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;
pg_data_t *pgdat = NULL;
bool new_pgdat;
bool new_node;
int ret;
start = res->start;
size = resource_size(res);
ret = check_hotplug_memory_range(start, size);
if (ret)
return ret;
{ /* Stupid hack to suppress address-never-null warning */
void *p = NODE_DATA(nid);
new_pgdat = !p;
}
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);
new_node = !node_online(nid);
if (new_node) {
pgdat = hotadd_new_pgdat(nid, start);
ret = -ENOMEM;
if (!pgdat)
goto error;
}
/* call arch's memory hotadd */
ret = arch_add_memory(nid, start, size, false);
if (ret < 0)
goto error;
/* we online node here. we can't roll back from here. */
node_set_online(nid);
if (new_node) {
ret = register_one_node(nid);
/*
* If sysfs file of new node can't create, cpu on the node
* can't be hot-added. There is no rollback way now.
* So, check by BUG_ON() to catch it reluctantly..
*/
BUG_ON(ret);
}
/* create new memmap entry */
firmware_map_add_hotplug(start, start + size, "System RAM");
/* 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_pgdat)
rollback_node_hotadd(nid, pgdat);
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 [31mCONFIG_MEMORY_HOTREMOVE[0m
/*
* A free page on the buddy free lists (not the per-cpu lists) has PageBuddy
* set and the size of the free page is given by page_order(). Using this,
* the function determines if the pageblock contains only free pages.
* Due to buddy contraints, a free page at least the size of a pageblock will
* be located at the start of the pageblock
*/
static inline int pageblock_free(struct page *page)
{
return PageBuddy(page) && page_order(page) >= pageblock_order;
}
/* Return the start of the next active pageblock after a given page */
static struct page *next_active_pageblock(struct page *page)
{
/* Ensure the starting page is pageblock-aligned */
BUG_ON(page_to_pfn(page) & (pageblock_nr_pages - 1));
/* If the entire pageblock is free, move to the end of free page */
if (pageblock_free(page)) {
int order;
/* be careful. we don't have locks, page_order can be changed.*/
order = page_order(page);
if ((order < MAX_ORDER) && (order >= pageblock_order))
return page + (1 << order);
}
return page + pageblock_nr_pages;
}
/* Checks if this range of memory is likely to be hot-removable. */
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)
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 = end;
return 1;
} else {
return 0;
}
}
/*
* Scan pfn range [start,end) to find movable/migratable pages (LRU pages
* and hugepages). We scan pfn because it's much easier than scanning over
* linked list. This function returns the pfn of the first found movable
* page if it's found, otherwise 0.
*/
static unsigned long scan_movable_pages(unsigned long start, unsigned long end)
{
unsigned long pfn;
struct page *page;
for (pfn = start; pfn < end; pfn++) {
if (pfn_valid(pfn)) {
page = pfn_to_page(pfn);
if (PageLRU(page))
return pfn;
if (PageHuge(page)) {
if (page_huge_active(page))
return pfn;
else
pfn = round_up(pfn + 1,
1 << compound_order(page)) - 1;
}
}
}
return 0;
}
static struct page *new_node_page(struct page *page, unsigned long private,
int **result)
{
gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE;
int nid = page_to_nid(page);
nodemask_t nmask = node_states[N_MEMORY];
struct page *new_page = NULL;
/*
* TODO: allocate a destination hugepage from a nearest neighbor node,
* accordance with memory policy of the user process if possible. For
* now as a simple work-around, we use the next node for destination.
*/
if (PageHuge(page))
return alloc_huge_page_node(page_hstate(compound_head(page)),
next_node_in(nid, nmask));
node_clear(nid, nmask);
if (PageHighMem(page)
|| (zone_idx(page_zone(page)) == ZONE_MOVABLE))
gfp_mask |= __GFP_HIGHMEM;
if (!nodes_empty(nmask))
new_page = __alloc_pages_nodemask(gfp_mask, 0,
node_zonelist(nid, gfp_mask), &nmask);
if (!new_page)
new_page = __alloc_pages(gfp_mask, 0,
node_zonelist(nid, gfp_mask));
return new_page;
}
#define NR_OFFLINE_AT_ONCE_PAGES (256)
static int
do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
{
unsigned long pfn;
struct page *page;
int move_pages = NR_OFFLINE_AT_ONCE_PAGES;
int not_managed = 0;
int ret = 0;
LIST_HEAD(source);
for (pfn = start_pfn; pfn < end_pfn && move_pages > 0; pfn++) {
if (!pfn_valid(pfn))
continue;
page = pfn_to_page(pfn);
if (PageHuge(page)) {
struct page *head = compound_head(page);
pfn = page_to_pfn(head) + (1<<compound_order(head)) - 1;
if (compound_order(head) > PFN_SECTION_SHIFT) {
ret = -EBUSY;
break;
}
if (isolate_huge_page(page, &source))
move_pages -= 1 << compound_order(head);
continue;
}
if (!get_page_unless_zero(page))
continue;
/*
* We can skip free pages. And we can only deal with pages on
* LRU.
*/
ret = isolate_lru_page(page);
if (!ret) { /* Success */
put_page(page);
list_add_tail(&page->lru, &source);
move_pages--;
inc_node_page_state(page, NR_ISOLATED_ANON +
page_is_file_cache(page));
} else {
#ifdef [31mCONFIG_DEBUG_VM[0m
pr_alert("removing pfn %lx from LRU failed\n", pfn);
dump_page(page, "failed to remove from LRU");
#endif
put_page(page);
/* Because we don't have big zone->lock. we should
check this again here. */
if (page_count(page)) {
not_managed++;
ret = -EBUSY;
break;
}
}
}
if (!list_empty(&source)) {
if (not_managed) {
putback_movable_pages(&source);
goto out;
}
/* 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;
}
#ifdef [31mCONFIG_MOVABLE_NODE[0m
/*
* When CONFIG_MOVABLE_NODE, we permit offlining of a node which doesn't have
* normal memory.
*/
static bool can_offline_normal(struct zone *zone, unsigned long nr_pages)
{
return true;
}
#else /* CONFIG_MOVABLE_NODE */
/* ensure the node has NORMAL memory if it is still online */
static bool can_offline_normal(struct zone *zone, unsigned long nr_pages)
{
struct pglist_data *pgdat = zone->zone_pgdat;
unsigned long present_pages = 0;
enum zone_type zt;
for (zt = 0; zt <= ZONE_NORMAL; zt++)
present_pages += pgdat->node_zones[zt].present_pages;
if (present_pages > nr_pages)
return true;
present_pages = 0;
for (; zt <= ZONE_MOVABLE; zt++)
present_pages += pgdat->node_zones[zt].present_pages;
/*
* we can't offline the last normal memory until all
* higher memory is offlined.
*/
return present_pages == 0;
}
#endif /* CONFIG_MOVABLE_NODE */
static int __init cmdline_parse_movable_node(char *p)
{
#ifdef [31mCONFIG_MOVABLE_NODE[0m
movable_node_enabled = true;
#else
pr_warn("movable_node option not supported\n");
#endif
return 0;
}
early_param("movable_node", cmdline_parse_movable_node);
/* check which state of node_states will be changed when offline memory */
static void node_states_check_changes_offline(unsigned long nr_pages,
struct zone *zone, struct memory_notify *arg)
{
struct pglist_data *pgdat = zone->zone_pgdat;
unsigned long present_pages = 0;
enum zone_type zt, zone_last = ZONE_NORMAL;
/*
* If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY]
* contains nodes which have zones of 0...ZONE_NORMAL,
* set zone_last to ZONE_NORMAL.
*
* If we don't have HIGHMEM nor movable node,
* node_states[N_NORMAL_MEMORY] contains nodes which have zones of
* 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE.
*/
if (N_MEMORY == N_NORMAL_MEMORY)
zone_last = ZONE_MOVABLE;
/*
* check whether node_states[N_NORMAL_MEMORY] will be changed.
* If the memory to be offline is in a zone of 0...zone_last,
* and it is the last present memory, 0...zone_last will
* become empty after offline , thus we can determind we will
* need to clear the node from node_states[N_NORMAL_MEMORY].
*/
for (zt = 0; zt <= zone_last; zt++)
present_pages += pgdat->node_zones[zt].present_pages;
if (zone_idx(zone) <= zone_last && nr_pages >= present_pages)
arg->status_change_nid_normal = zone_to_nid(zone);
else
arg->status_change_nid_normal = -1;
#ifdef [31mCONFIG_HIGHMEM[0m
/*
* If we have movable node, node_states[N_HIGH_MEMORY]
* contains nodes which have zones of 0...ZONE_HIGHMEM,
* set zone_last to ZONE_HIGHMEM.
*
* If we don't have movable node, node_states[N_NORMAL_MEMORY]
* contains nodes which have zones of 0...ZONE_MOVABLE,
* set zone_last to ZONE_MOVABLE.
*/
zone_last = ZONE_HIGHMEM;
if (N_MEMORY == N_HIGH_MEMORY)
zone_last = ZONE_MOVABLE;
for (; zt <= zone_last; zt++)
present_pages += pgdat->node_zones[zt].present_pages;
if (zone_idx(zone) <= zone_last && nr_pages >= present_pages)
arg->status_change_nid_high = zone_to_nid(zone);
else
arg->status_change_nid_high = -1;
#else
arg->status_change_nid_high = arg->status_change_nid_normal;
#endif
/*
* node_states[N_HIGH_MEMORY] contains nodes which have 0...ZONE_MOVABLE
*/
zone_last = ZONE_MOVABLE;
/*
* check whether node_states[N_HIGH_MEMORY] will be changed
* If we try to offline the last present @nr_pages from the node,
* we can determind we will need to clear the node from
* node_states[N_HIGH_MEMORY].
*/
for (; zt <= zone_last; zt++)
present_pages += pgdat->node_zones[zt].present_pages;
if (nr_pages >= present_pages)
arg->status_change_nid = zone_to_nid(zone);
else
arg->status_change_nid = -1;
}
static void node_states_clear_node(int node, struct memory_notify *arg)
{
if (arg->status_change_nid_normal >= 0)
node_clear_state(node, N_NORMAL_MEMORY);
if ((N_MEMORY != N_NORMAL_MEMORY) &&
(arg->status_change_nid_high >= 0))
node_clear_state(node, N_HIGH_MEMORY);
if ((N_MEMORY != N_HIGH_MEMORY) &&
(arg->status_change_nid >= 0))
node_clear_state(node, N_MEMORY);
}
static int __ref __offline_pages(unsigned long start_pfn,
unsigned long end_pfn, unsigned long timeout)
{
unsigned long pfn, nr_pages, expire;
long offlined_pages;
int ret, drain, retry_max, node;
unsigned long flags;
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;
if (zone_idx(zone) <= ZONE_NORMAL && !can_offline_normal(zone, nr_pages))
return -EINVAL;
/* set above range as isolated */
ret = start_isolate_page_range(start_pfn, end_pfn,
MIGRATE_MOVABLE, true);
if (ret)
return ret;
arg.start_pfn = start_pfn;
arg.nr_pages = nr_pages;
node_states_check_changes_offline(nr_pages, zone, &arg);
ret = memory_notify(MEM_GOING_OFFLINE, &arg);
ret = notifier_to_errno(ret);
if (ret)
goto failed_removal;
pfn = start_pfn;
expire = jiffies + timeout;
drain = 0;
retry_max = 5;
repeat:
/* start memory hot removal */
ret = -EAGAIN;
if (time_after(jiffies, expire))
goto failed_removal;
ret = -EINTR;
if (signal_pending(current))
goto failed_removal;
ret = 0;
if (drain) {
lru_add_drain_all();
cond_resched();
drain_all_pages(zone);
}
pfn = scan_movable_pages(start_pfn, end_pfn);
if (pfn) { /* We have movable pages */
ret = do_migrate_range(pfn, end_pfn);
if (!ret) {
drain = 1;
goto repeat;
} else {
if (ret < 0)
if (--retry_max == 0)
goto failed_removal;
yield();
drain = 1;
goto repeat;
}
}
/* drain all zone's lru pagevec, this is asynchronous... */
lru_add_drain_all();
yield();
/* drain pcp pages, this is synchronous. */
drain_all_pages(zone);
/*
* dissolve free hugepages in the memory block before doing offlining
* actually in order to make hugetlbfs's object counting consistent.
*/
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) {
ret = -EBUSY;
goto failed_removal;
}
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);
mutex_lock(&zonelists_mutex);
build_all_zonelists(NULL, NULL);
mutex_unlock(&zonelists_mutex);
} else
zone_pcp_update(zone);
node_states_clear_node(node, &arg);
if (arg.status_change_nid >= 0) {
kswapd_stop(node);
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() */
int offline_pages(unsigned long start_pfn, unsigned long nr_pages)
{
return __offline_pages(start_pfn, start_pfn + nr_pages, 120 * HZ);
}
#endif /* CONFIG_MEMORY_HOTREMOVE */
/**
* walk_memory_range - walks through all mem sections in [start_pfn, end_pfn)
* @start_pfn: start pfn of the memory range
* @end_pfn: end pfn of the memory range
* @arg: argument passed to func
* @func: callback for each memory section walked
*
* This function walks through all present mem sections in range
* [start_pfn, end_pfn) and call func on each mem section.
*
* Returns the return value of func.
*/
int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn,
void *arg, int (*func)(struct memory_block *, void *))
{
struct memory_block *mem = NULL;
struct mem_section *section;
unsigned long pfn, section_nr;
int ret;
for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
section_nr = pfn_to_section_nr(pfn);
if (!present_section_nr(section_nr))
continue;
section = __nr_to_section(section_nr);
/* same memblock? */
if (mem)
if ((section_nr >= mem->start_section_nr) &&
(section_nr <= mem->end_section_nr))
continue;
mem = find_memory_block_hinted(section, mem);
if (!mem)
continue;
ret = func(mem, arg);
if (ret) {
kobject_put(&mem->dev.kobj);
return ret;
}
}
if (mem)
kobject_put(&mem->dev.kobj);
return 0;
}
#ifdef [31mCONFIG_MEMORY_HOTREMOVE[0m
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 [31mCONFIG_ACPI_NUMA[0m
int cpu;
for_each_possible_cpu(cpu)
if (cpu_to_node(cpu) == pgdat->node_id)
numa_clear_node(cpu);
#endif
}
static int check_and_unmap_cpu_on_node(pg_data_t *pgdat)
{
int ret;
ret = check_cpu_on_node(pgdat);
if (ret)
return ret;
/*
* the node will be offlined when we come here, so we can clear
* the cpu_to_node() now.
*/
unmap_cpu_on_node(pgdat);
return 0;
}
/**
* try_offline_node
*
* Offline a node if all memory sections and cpus of the node are removed.
*
* NOTE: The caller must call lock_device_hotplug() to serialize hotplug
* and online/offline operations before this call.
*/
void try_offline_node(int nid)
{
pg_data_t *pgdat = NODE_DATA(nid);
unsigned long start_pfn = pgdat->node_start_pfn;
unsigned long end_pfn = start_pfn + pgdat->node_spanned_pages;
unsigned long pfn;
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
*
* 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);
try_offline_node(nid);
mem_hotplug_done();
}
EXPORT_SYMBOL_GPL(remove_memory);
#endif /* CONFIG_MEMORY_HOTREMOVE */