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/writeback.h>
17 #include <linux/slab.h>
18 #include <linux/sysctl.h>
19 #include <linux/cpu.h>
20 #include <linux/memory.h>
21 #include <linux/memory_hotplug.h>
22 #include <linux/highmem.h>
23 #include <linux/vmalloc.h>
24 #include <linux/ioport.h>
25 #include <linux/cpuset.h>
27 #include <asm/tlbflush.h>
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 static int __add_section(struct zone *zone, unsigned long phys_start_pfn)
50 int nr_pages = PAGES_PER_SECTION;
53 if (pfn_valid(phys_start_pfn))
56 ret = sparse_add_one_section(zone, phys_start_pfn, nr_pages);
61 ret = __add_zone(zone, phys_start_pfn);
66 return register_new_memory(__pfn_to_section(phys_start_pfn));
70 * Reasonably generic function for adding memory. It is
71 * expected that archs that support memory hotplug will
72 * call this function after deciding the zone to which to
75 int __add_pages(struct zone *zone, unsigned long phys_start_pfn,
76 unsigned long nr_pages)
80 int start_sec, end_sec;
81 /* during initialize mem_map, align hot-added range to section */
82 start_sec = pfn_to_section_nr(phys_start_pfn);
83 end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1);
85 for (i = start_sec; i <= end_sec; i++) {
86 err = __add_section(zone, i << PFN_SECTION_SHIFT);
89 * EEXIST is finally dealed with by ioresource collision
90 * check. see add_memory() => register_memory_resource()
91 * Warning will be printed if there is collision.
93 if (err && (err != -EEXIST))
100 EXPORT_SYMBOL_GPL(__add_pages);
102 static void grow_zone_span(struct zone *zone,
103 unsigned long start_pfn, unsigned long end_pfn)
105 unsigned long old_zone_end_pfn;
107 zone_span_writelock(zone);
109 old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages;
110 if (start_pfn < zone->zone_start_pfn)
111 zone->zone_start_pfn = start_pfn;
113 zone->spanned_pages = max(old_zone_end_pfn, end_pfn) -
114 zone->zone_start_pfn;
116 zone_span_writeunlock(zone);
119 static void grow_pgdat_span(struct pglist_data *pgdat,
120 unsigned long start_pfn, unsigned long end_pfn)
122 unsigned long old_pgdat_end_pfn =
123 pgdat->node_start_pfn + pgdat->node_spanned_pages;
125 if (start_pfn < pgdat->node_start_pfn)
126 pgdat->node_start_pfn = start_pfn;
128 pgdat->node_spanned_pages = max(old_pgdat_end_pfn, end_pfn) -
129 pgdat->node_start_pfn;
132 int online_pages(unsigned long pfn, unsigned long nr_pages)
136 unsigned long onlined_pages = 0;
139 unsigned long start_pfn;
141 int need_zonelists_rebuild = 0;
144 * This doesn't need a lock to do pfn_to_page().
145 * The section can't be removed here because of the
146 * memory_block->state_sem.
148 zone = page_zone(pfn_to_page(pfn));
149 pgdat_resize_lock(zone->zone_pgdat, &flags);
150 grow_zone_span(zone, pfn, pfn + nr_pages);
151 grow_pgdat_span(zone->zone_pgdat, pfn, pfn + nr_pages);
152 pgdat_resize_unlock(zone->zone_pgdat, &flags);
155 * If this zone is not populated, then it is not in zonelist.
156 * This means the page allocator ignores this zone.
157 * So, zonelist must be updated after online.
159 if (!populated_zone(zone))
160 need_zonelists_rebuild = 1;
162 res.start = (u64)pfn << PAGE_SHIFT;
163 res.end = res.start + ((u64)nr_pages << PAGE_SHIFT) - 1;
164 res.flags = IORESOURCE_MEM; /* we just need system ram */
165 section_end = res.end;
167 while ((res.start < res.end) && (find_next_system_ram(&res) >= 0)) {
168 start_pfn = (unsigned long)(res.start >> PAGE_SHIFT);
169 nr_pages = (unsigned long)
170 ((res.end + 1 - res.start) >> PAGE_SHIFT);
172 if (PageReserved(pfn_to_page(start_pfn))) {
173 /* this region's page is not onlined now */
174 for (i = 0; i < nr_pages; i++) {
175 struct page *page = pfn_to_page(start_pfn + i);
181 res.start = res.end + 1;
182 res.end = section_end;
184 zone->present_pages += onlined_pages;
185 zone->zone_pgdat->node_present_pages += onlined_pages;
187 setup_per_zone_pages_min();
189 if (need_zonelists_rebuild)
190 build_all_zonelists();
191 vm_total_pages = nr_free_pagecache_pages();
192 writeback_set_ratelimit();
196 static pg_data_t *hotadd_new_pgdat(int nid, u64 start)
198 struct pglist_data *pgdat;
199 unsigned long zones_size[MAX_NR_ZONES] = {0};
200 unsigned long zholes_size[MAX_NR_ZONES] = {0};
201 unsigned long start_pfn = start >> PAGE_SHIFT;
203 pgdat = arch_alloc_nodedata(nid);
207 arch_refresh_nodedata(nid, pgdat);
209 /* we can use NODE_DATA(nid) from here */
211 /* init node's zones as empty zones, we don't have any present pages.*/
212 free_area_init_node(nid, pgdat, zones_size, start_pfn, zholes_size);
217 static void rollback_node_hotadd(int nid, pg_data_t *pgdat)
219 arch_refresh_nodedata(nid, NULL);
220 arch_free_nodedata(pgdat);
224 /* add this memory to iomem resource */
225 static struct resource *register_memory_resource(u64 start, u64 size)
227 struct resource *res;
228 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
231 res->name = "System RAM";
233 res->end = start + size - 1;
234 res->flags = IORESOURCE_MEM;
235 if (request_resource(&iomem_resource, res) < 0) {
236 printk("System RAM resource %llx - %llx cannot be added\n",
237 (unsigned long long)res->start, (unsigned long long)res->end);
244 static void release_memory_resource(struct resource *res)
248 release_resource(res);
255 int add_memory(int nid, u64 start, u64 size)
257 pg_data_t *pgdat = NULL;
259 struct resource *res;
262 res = register_memory_resource(start, size);
266 if (!node_online(nid)) {
267 pgdat = hotadd_new_pgdat(nid, start);
271 ret = kswapd_run(nid);
276 /* call arch's memory hotadd */
277 ret = arch_add_memory(nid, start, size);
282 /* we online node here. we can't roll back from here. */
283 node_set_online(nid);
285 cpuset_track_online_nodes();
288 ret = register_one_node(nid);
290 * If sysfs file of new node can't create, cpu on the node
291 * can't be hot-added. There is no rollback way now.
292 * So, check by BUG_ON() to catch it reluctantly..
299 /* rollback pgdat allocation and others */
301 rollback_node_hotadd(nid, pgdat);
303 release_memory_resource(res);
307 EXPORT_SYMBOL_GPL(add_memory);