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/*
* 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/bootmem.h>
#include <linux/compiler.h>
#include <linux/module.h>
#include <linux/pagevec.h>
#include <linux/writeback.h>
#include <linux/slab.h>
#include <linux/sysctl.h>
#include <linux/cpu.h>
#include <linux/memory.h>
#include <linux/memory_hotplug.h>
#include <linux/highmem.h>
#include <linux/vmalloc.h>
#include <linux/ioport.h>
#include <linux/cpuset.h>
#include <asm/tlbflush.h>
/* add this memory to iomem resource */
static struct resource *register_memory_resource(u64 start, u64 size)
{
struct resource *res;
res = kzalloc(sizeof(struct resource), GFP_KERNEL);
BUG_ON(!res);
res->name = "System RAM";
res->start = start;
res->end = start + size - 1;
res->flags = IORESOURCE_MEM;
if (request_resource(&iomem_resource, res) < 0) {
printk("System RAM resource %llx - %llx cannot be added\n",
(unsigned long long)res->start, (unsigned long long)res->end);
kfree(res);
res = NULL;
}
return res;
}
static void release_memory_resource(struct resource *res)
{
if (!res)
return;
release_resource(res);
kfree(res);
return;
}
#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
static int __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;
zone_type = zone - pgdat->node_zones;
if (!populated_zone(zone)) {
int ret = 0;
ret = init_currently_empty_zone(zone, phys_start_pfn, nr_pages);
if (ret < 0)
return ret;
}
memmap_init_zone(nr_pages, nid, zone_type, phys_start_pfn);
return 0;
}
static int __add_section(struct zone *zone, unsigned long phys_start_pfn)
{
int nr_pages = PAGES_PER_SECTION;
int ret;
if (pfn_valid(phys_start_pfn))
return -EEXIST;
ret = sparse_add_one_section(zone, phys_start_pfn, nr_pages);
if (ret < 0)
return ret;
ret = __add_zone(zone, phys_start_pfn);
if (ret < 0)
return ret;
return register_new_memory(__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 __add_pages(struct zone *zone, unsigned long phys_start_pfn,
unsigned long nr_pages)
{
unsigned long i;
int err = 0;
int start_sec, end_sec;
/* during initialize mem_map, align hot-added range to section */
start_sec = pfn_to_section_nr(phys_start_pfn);
end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1);
for (i = start_sec; i <= end_sec; i++) {
err = __add_section(zone, i << PFN_SECTION_SHIFT);
/*
* EEXIST is finally dealed with by ioresource collision
* check. see add_memory() => register_memory_resource()
* Warning will be printed if there is collision.
*/
if (err && (err != -EEXIST))
break;
err = 0;
}
return err;
}
EXPORT_SYMBOL_GPL(__add_pages);
static void 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->zone_start_pfn + zone->spanned_pages;
if (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 grow_pgdat_span(struct pglist_data *pgdat,
unsigned long start_pfn, unsigned long end_pfn)
{
unsigned long old_pgdat_end_pfn =
pgdat->node_start_pfn + pgdat->node_spanned_pages;
if (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;
}
int online_pages(unsigned long pfn, unsigned long nr_pages)
{
unsigned long i;
unsigned long flags;
unsigned long onlined_pages = 0;
struct resource res;
u64 section_end;
unsigned long start_pfn;
struct zone *zone;
int need_zonelists_rebuild = 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_sem.
*/
zone = page_zone(pfn_to_page(pfn));
pgdat_resize_lock(zone->zone_pgdat, &flags);
grow_zone_span(zone, pfn, pfn + nr_pages);
grow_pgdat_span(zone->zone_pgdat, pfn, pfn + nr_pages);
pgdat_resize_unlock(zone->zone_pgdat, &flags);
/*
* 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;
res.start = (u64)pfn << PAGE_SHIFT;
res.end = res.start + ((u64)nr_pages << PAGE_SHIFT) - 1;
res.flags = IORESOURCE_MEM; /* we just need system ram */
section_end = res.end;
while ((res.start < res.end) && (find_next_system_ram(&res) >= 0)) {
start_pfn = (unsigned long)(res.start >> PAGE_SHIFT);
nr_pages = (unsigned long)
((res.end + 1 - res.start) >> PAGE_SHIFT);
if (PageReserved(pfn_to_page(start_pfn))) {
/* this region's page is not onlined now */
for (i = 0; i < nr_pages; i++) {
struct page *page = pfn_to_page(start_pfn + i);
online_page(page);
onlined_pages++;
}
}
res.start = res.end + 1;
res.end = section_end;
}
zone->present_pages += onlined_pages;
zone->zone_pgdat->node_present_pages += onlined_pages;
setup_per_zone_pages_min();
if (need_zonelists_rebuild)
build_all_zonelists();
vm_total_pages = nr_free_pagecache_pages();
writeback_set_ratelimit();
return 0;
}
#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
static pg_data_t *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 = start >> PAGE_SHIFT;
pgdat = arch_alloc_nodedata(nid);
if (!pgdat)
return NULL;
arch_refresh_nodedata(nid, pgdat);
/* 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, pgdat, zones_size, start_pfn, zholes_size);
return pgdat;
}
static void rollback_node_hotadd(int nid, pg_data_t *pgdat)
{
arch_refresh_nodedata(nid, NULL);
arch_free_nodedata(pgdat);
return;
}
int add_memory(int nid, u64 start, u64 size)
{
pg_data_t *pgdat = NULL;
int new_pgdat = 0;
struct resource *res;
int ret;
res = register_memory_resource(start, size);
if (!res)
return -EEXIST;
if (!node_online(nid)) {
pgdat = hotadd_new_pgdat(nid, start);
if (!pgdat)
return -ENOMEM;
new_pgdat = 1;
ret = kswapd_run(nid);
if (ret)
goto error;
}
/* call arch's memory hotadd */
ret = arch_add_memory(nid, start, size);
if (ret < 0)
goto error;
/* we online node here. we can't roll back from here. */
node_set_online(nid);
cpuset_track_online_nodes();
if (new_pgdat) {
ret =
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