2 * linux/mm/memory_hotplug.c
7 #include <linux/stddef.h>
9 #include <linux/swap.h>
10 #include <linux/interrupt.h>
11 #include <linux/pagemap.h>
12 #include <linux/bootmem.h>
13 #include <linux/compiler.h>
14 #include <linux/module.h>
15 #include <linux/pagevec.h>
16 #include <linux/slab.h>
17 #include <linux/sysctl.h>
18 #include <linux/cpu.h>
19 #include <linux/memory.h>
20 #include <linux/memory_hotplug.h>
21 #include <linux/highmem.h>
22 #include <linux/vmalloc.h>
23 #include <linux/ioport.h>
25 #include <asm/tlbflush.h>
27 extern void zonetable_add(struct zone *zone, int nid, int zid, unsigned long pfn,
29 static int __add_zone(struct zone *zone, unsigned long phys_start_pfn)
31 struct pglist_data *pgdat = zone->zone_pgdat;
32 int nr_pages = PAGES_PER_SECTION;
33 int nid = pgdat->node_id;
36 zone_type = zone - pgdat->node_zones;
37 if (!populated_zone(zone)) {
39 ret = init_currently_empty_zone(zone, phys_start_pfn, nr_pages);
43 memmap_init_zone(nr_pages, nid, zone_type, phys_start_pfn);
44 zonetable_add(zone, nid, zone_type, phys_start_pfn, nr_pages);
48 extern int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
50 static int __add_section(struct zone *zone, unsigned long phys_start_pfn)
52 int nr_pages = PAGES_PER_SECTION;
55 ret = sparse_add_one_section(zone, phys_start_pfn, nr_pages);
60 ret = __add_zone(zone, phys_start_pfn);
65 return register_new_memory(__pfn_to_section(phys_start_pfn));
69 * Reasonably generic function for adding memory. It is
70 * expected that archs that support memory hotplug will
71 * call this function after deciding the zone to which to
74 int __add_pages(struct zone *zone, unsigned long phys_start_pfn,
75 unsigned long nr_pages)
79 int start_sec, end_sec;
80 /* during initialize mem_map, align hot-added range to section */
81 start_sec = pfn_to_section_nr(phys_start_pfn);
82 end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1);
84 for (i = start_sec; i <= end_sec; i++) {
85 err = __add_section(zone, i << PFN_SECTION_SHIFT);
88 * EEXIST is finally dealed with by ioresource collision
89 * check. see add_memory() => register_memory_resource()
90 * Warning will be printed if there is collision.
92 if (err && (err != -EEXIST))
99 EXPORT_SYMBOL_GPL(__add_pages);
101 static void grow_zone_span(struct zone *zone,
102 unsigned long start_pfn, unsigned long end_pfn)
104 unsigned long old_zone_end_pfn;
106 zone_span_writelock(zone);
108 old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages;
109 if (start_pfn < zone->zone_start_pfn)
110 zone->zone_start_pfn = start_pfn;
112 zone->spanned_pages = max(old_zone_end_pfn, end_pfn) -
113 zone->zone_start_pfn;
115 zone_span_writeunlock(zone);
118 static void grow_pgdat_span(struct pglist_data *pgdat,
119 unsigned long start_pfn, unsigned long end_pfn)
121 unsigned long old_pgdat_end_pfn =
122 pgdat->node_start_pfn + pgdat->node_spanned_pages;
124 if (start_pfn < pgdat->node_start_pfn)
125 pgdat->node_start_pfn = start_pfn;
127 pgdat->node_spanned_pages = max(old_pgdat_end_pfn, end_pfn) -
128 pgdat->node_start_pfn;
131 int online_pages(unsigned long pfn, unsigned long nr_pages)
135 unsigned long onlined_pages = 0;
138 unsigned long start_pfn;
140 int need_zonelists_rebuild = 0;
143 * This doesn't need a lock to do pfn_to_page().
144 * The section can't be removed here because of the
145 * memory_block->state_sem.
147 zone = page_zone(pfn_to_page(pfn));
148 pgdat_resize_lock(zone->zone_pgdat, &flags);
149 grow_zone_span(zone, pfn, pfn + nr_pages);
150 grow_pgdat_span(zone->zone_pgdat, pfn, pfn + nr_pages);
151 pgdat_resize_unlock(zone->zone_pgdat, &flags);
154 * If this zone is not populated, then it is not in zonelist.
155 * This means the page allocator ignores this zone.
156 * So, zonelist must be updated after online.
158 if (!populated_zone(zone))
159 need_zonelists_rebuild = 1;
161 res.start = (u64)pfn << PAGE_SHIFT;
162 res.end = res.start + ((u64)nr_pages << PAGE_SHIFT) - 1;
163 res.flags = IORESOURCE_MEM; /* we just need system ram */
164 section_end = res.end;
166 while ((res.start < res.end) && (find_next_system_ram(&res) >= 0)) {
167 start_pfn = (unsigned long)(res.start >> PAGE_SHIFT);
168 nr_pages = (unsigned long)
169 ((res.end + 1 - res.start) >> PAGE_SHIFT);
171 if (PageReserved(pfn_to_page(start_pfn))) {
172 /* this region's page is not onlined now */
173 for (i = 0; i < nr_pages; i++) {
174 struct page *page = pfn_to_page(start_pfn + i);
180 res.start = res.end + 1;
181 res.end = section_end;
183 zone->present_pages += onlined_pages;
184 zone->zone_pgdat->node_present_pages += onlined_pages;
186 setup_per_zone_pages_min();
188 if (need_zonelists_rebuild)
189 build_all_zonelists();
190 vm_total_pages = nr_free_pagecache_pages();
194 static pg_data_t *hotadd_new_pgdat(int nid, u64 start)
196 struct pglist_data *pgdat;
197 unsigned long zones_size[MAX_NR_ZONES] = {0};
198 unsigned long zholes_size[MAX_NR_ZONES] = {0};
199 unsigned long start_pfn = start >> PAGE_SHIFT;
201 pgdat = arch_alloc_nodedata(nid);
205 arch_refresh_nodedata(nid, pgdat);
207 /* we can use NODE_DATA(nid) from here */
209 /* init node's zones as empty zones, we don't have any present pages.*/
210 free_area_init_node(nid, pgdat, zones_size, start_pfn, zholes_size);
215 static void rollback_node_hotadd(int nid, pg_data_t *pgdat)
217 arch_refresh_nodedata(nid, NULL);
218 arch_free_nodedata(pgdat);
222 /* add this memory to iomem resource */
223 static int register_memory_resource(u64 start, u64 size)
225 struct resource *res;
227 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
230 res->name = "System RAM";
232 res->end = start + size - 1;
233 res->flags = IORESOURCE_MEM;
234 if (request_resource(&iomem_resource, res) < 0) {
235 printk("System RAM resource %llx - %llx cannot be added\n",
236 (unsigned long long)res->start, (unsigned long long)res->end);
245 int add_memory(int nid, u64 start, u64 size)
247 pg_data_t *pgdat = NULL;
251 if (!node_online(nid)) {
252 pgdat = hotadd_new_pgdat(nid, start);
256 ret = kswapd_run(nid);
261 /* call arch's memory hotadd */
262 ret = arch_add_memory(nid, start, size);
267 /* we online node here. we can't roll back from here. */
268 node_set_online(nid);
271 ret = register_one_node(nid);
273 * If sysfs file of new node can't create, cpu on the node
274 * can't be hot-added. There is no rollback way now.
275 * So, check by BUG_ON() to catch it reluctantly..
280 /* register this memory as resource */
281 ret = register_memory_resource(start, size);
285 /* rollback pgdat allocation and others */
287 rollback_node_hotadd(nid, pgdat);
291 EXPORT_SYMBOL_GPL(add_memory);