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 /* add this memory to iomem resource */
30 static struct resource
*register_memory_resource(u64 start
, u64 size
)
33 res
= kzalloc(sizeof(struct resource
), GFP_KERNEL
);
36 res
->name
= "System RAM";
38 res
->end
= start
+ size
- 1;
39 res
->flags
= IORESOURCE_MEM
;
40 if (request_resource(&iomem_resource
, res
) < 0) {
41 printk("System RAM resource %llx - %llx cannot be added\n",
42 (unsigned long long)res
->start
, (unsigned long long)res
->end
);
49 static void release_memory_resource(struct resource
*res
)
53 release_resource(res
);
59 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
60 static int __add_zone(struct zone
*zone
, unsigned long phys_start_pfn
)
62 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
63 int nr_pages
= PAGES_PER_SECTION
;
64 int nid
= pgdat
->node_id
;
67 zone_type
= zone
- pgdat
->node_zones
;
68 if (!zone
->wait_table
) {
70 ret
= init_currently_empty_zone(zone
, phys_start_pfn
,
71 nr_pages
, MEMMAP_HOTPLUG
);
75 memmap_init_zone(nr_pages
, nid
, zone_type
,
76 phys_start_pfn
, MEMMAP_HOTPLUG
);
80 static int __add_section(struct zone
*zone
, unsigned long phys_start_pfn
)
82 int nr_pages
= PAGES_PER_SECTION
;
85 if (pfn_valid(phys_start_pfn
))
88 ret
= sparse_add_one_section(zone
, phys_start_pfn
, nr_pages
);
93 ret
= __add_zone(zone
, phys_start_pfn
);
98 return register_new_memory(__pfn_to_section(phys_start_pfn
));
102 * Reasonably generic function for adding memory. It is
103 * expected that archs that support memory hotplug will
104 * call this function after deciding the zone to which to
107 int __add_pages(struct zone
*zone
, unsigned long phys_start_pfn
,
108 unsigned long nr_pages
)
112 int start_sec
, end_sec
;
113 /* during initialize mem_map, align hot-added range to section */
114 start_sec
= pfn_to_section_nr(phys_start_pfn
);
115 end_sec
= pfn_to_section_nr(phys_start_pfn
+ nr_pages
- 1);
117 for (i
= start_sec
; i
<= end_sec
; i
++) {
118 err
= __add_section(zone
, i
<< PFN_SECTION_SHIFT
);
121 * EEXIST is finally dealed with by ioresource collision
122 * check. see add_memory() => register_memory_resource()
123 * Warning will be printed if there is collision.
125 if (err
&& (err
!= -EEXIST
))
132 EXPORT_SYMBOL_GPL(__add_pages
);
134 static void grow_zone_span(struct zone
*zone
,
135 unsigned long start_pfn
, unsigned long end_pfn
)
137 unsigned long old_zone_end_pfn
;
139 zone_span_writelock(zone
);
141 old_zone_end_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
142 if (start_pfn
< zone
->zone_start_pfn
)
143 zone
->zone_start_pfn
= start_pfn
;
145 zone
->spanned_pages
= max(old_zone_end_pfn
, end_pfn
) -
146 zone
->zone_start_pfn
;
148 zone_span_writeunlock(zone
);
151 static void grow_pgdat_span(struct pglist_data
*pgdat
,
152 unsigned long start_pfn
, unsigned long end_pfn
)
154 unsigned long old_pgdat_end_pfn
=
155 pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
157 if (start_pfn
< pgdat
->node_start_pfn
)
158 pgdat
->node_start_pfn
= start_pfn
;
160 pgdat
->node_spanned_pages
= max(old_pgdat_end_pfn
, end_pfn
) -
161 pgdat
->node_start_pfn
;
164 static int online_pages_range(unsigned long start_pfn
, unsigned long nr_pages
,
168 unsigned long onlined_pages
= *(unsigned long *)arg
;
170 if (PageReserved(pfn_to_page(start_pfn
)))
171 for (i
= 0; i
< nr_pages
; i
++) {
172 page
= pfn_to_page(start_pfn
+ i
);
176 *(unsigned long *)arg
= onlined_pages
;
181 int online_pages(unsigned long pfn
, unsigned long nr_pages
)
184 unsigned long onlined_pages
= 0;
186 int need_zonelists_rebuild
= 0;
189 * This doesn't need a lock to do pfn_to_page().
190 * The section can't be removed here because of the
191 * memory_block->state_sem.
193 zone
= page_zone(pfn_to_page(pfn
));
194 pgdat_resize_lock(zone
->zone_pgdat
, &flags
);
195 grow_zone_span(zone
, pfn
, pfn
+ nr_pages
);
196 grow_pgdat_span(zone
->zone_pgdat
, pfn
, pfn
+ nr_pages
);
197 pgdat_resize_unlock(zone
->zone_pgdat
, &flags
);
200 * If this zone is not populated, then it is not in zonelist.
201 * This means the page allocator ignores this zone.
202 * So, zonelist must be updated after online.
204 if (!populated_zone(zone
))
205 need_zonelists_rebuild
= 1;
207 walk_memory_resource(pfn
, nr_pages
, &onlined_pages
,
209 zone
->present_pages
+= onlined_pages
;
210 zone
->zone_pgdat
->node_present_pages
+= onlined_pages
;
212 setup_per_zone_pages_min();
214 kswapd_run(zone_to_nid(zone
));
215 node_set_state(zone_to_nid(zone
), N_HIGH_MEMORY
);
218 if (need_zonelists_rebuild
)
219 build_all_zonelists();
220 vm_total_pages
= nr_free_pagecache_pages();
221 writeback_set_ratelimit();
224 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
226 static pg_data_t
*hotadd_new_pgdat(int nid
, u64 start
)
228 struct pglist_data
*pgdat
;
229 unsigned long zones_size
[MAX_NR_ZONES
] = {0};
230 unsigned long zholes_size
[MAX_NR_ZONES
] = {0};
231 unsigned long start_pfn
= start
>> PAGE_SHIFT
;
233 pgdat
= arch_alloc_nodedata(nid
);
237 arch_refresh_nodedata(nid
, pgdat
);
239 /* we can use NODE_DATA(nid) from here */
241 /* init node's zones as empty zones, we don't have any present pages.*/
242 free_area_init_node(nid
, pgdat
, zones_size
, start_pfn
, zholes_size
);
247 static void rollback_node_hotadd(int nid
, pg_data_t
*pgdat
)
249 arch_refresh_nodedata(nid
, NULL
);
250 arch_free_nodedata(pgdat
);
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
);
273 /* call arch's memory hotadd */
274 ret
= arch_add_memory(nid
, start
, size
);
279 /* we online node here. we can't roll back from here. */
280 node_set_online(nid
);
282 cpuset_track_online_nodes();
285 ret
= register_one_node(nid
);
287 * If sysfs file of new node can't create, cpu on the node
288 * can't be hot-added. There is no rollback way now.
289 * So, check by BUG_ON() to catch it reluctantly..
296 /* rollback pgdat allocation and others */
298 rollback_node_hotadd(nid
, pgdat
);
300 release_memory_resource(res
);
304 EXPORT_SYMBOL_GPL(add_memory
);