memory_hotplug.c revision 6811378e7d8b9aa4fca2a1ca73d24c9d67c9cb12 
1/*
2 *  linux/mm/memory_hotplug.c
3 *
4 *  Copyright (C)
5 */
6
7#include <linux/config.h>
8#include <linux/stddef.h>
9#include <linux/mm.h>
10#include <linux/swap.h>
11#include <linux/interrupt.h>
12#include <linux/pagemap.h>
13#include <linux/bootmem.h>
14#include <linux/compiler.h>
15#include <linux/module.h>
16#include <linux/pagevec.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
25#include <asm/tlbflush.h>
26
27extern void zonetable_add(struct zone *zone, int nid, int zid, unsigned long pfn,
28			  unsigned long size);
29static int __add_zone(struct zone *zone, unsigned long phys_start_pfn)
30{
31	struct pglist_data *pgdat = zone->zone_pgdat;
32	int nr_pages = PAGES_PER_SECTION;
33	int nid = pgdat->node_id;
34	int zone_type;
35
36	zone_type = zone - pgdat->node_zones;
37	if (!populated_zone(zone)) {
38		int ret = 0;
39		ret = init_currently_empty_zone(zone, phys_start_pfn, nr_pages);
40		if (ret < 0)
41			return ret;
42	}
43	memmap_init_zone(nr_pages, nid, zone_type, phys_start_pfn);
44	zonetable_add(zone, nid, zone_type, phys_start_pfn, nr_pages);
45	return 0;
46}
47
48extern int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
49				  int nr_pages);
50static int __add_section(struct zone *zone, unsigned long phys_start_pfn)
51{
52	int nr_pages = PAGES_PER_SECTION;
53	int ret;
54
55	ret = sparse_add_one_section(zone, phys_start_pfn, nr_pages);
56
57	if (ret < 0)
58		return ret;
59
60	ret = __add_zone(zone, phys_start_pfn);
61
62	if (ret < 0)
63		return ret;
64
65	return register_new_memory(__pfn_to_section(phys_start_pfn));
66}
67
68/*
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
72 * add the new pages.
73 */
74int __add_pages(struct zone *zone, unsigned long phys_start_pfn,
75		 unsigned long nr_pages)
76{
77	unsigned long i;
78	int err = 0;
79
80	for (i = 0; i < nr_pages; i += PAGES_PER_SECTION) {
81		err = __add_section(zone, phys_start_pfn + i);
82
83		/* We want to keep adding the rest of the
84		 * sections if the first ones already exist
85		 */
86		if (err && (err != -EEXIST))
87			break;
88	}
89
90	return err;
91}
92EXPORT_SYMBOL_GPL(__add_pages);
93
94static void grow_zone_span(struct zone *zone,
95		unsigned long start_pfn, unsigned long end_pfn)
96{
97	unsigned long old_zone_end_pfn;
98
99	zone_span_writelock(zone);
100
101	old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages;
102	if (start_pfn < zone->zone_start_pfn)
103		zone->zone_start_pfn = start_pfn;
104
105	zone->spanned_pages = max(old_zone_end_pfn, end_pfn) -
106				zone->zone_start_pfn;
107
108	zone_span_writeunlock(zone);
109}
110
111static void grow_pgdat_span(struct pglist_data *pgdat,
112		unsigned long start_pfn, unsigned long end_pfn)
113{
114	unsigned long old_pgdat_end_pfn =
115		pgdat->node_start_pfn + pgdat->node_spanned_pages;
116
117	if (start_pfn < pgdat->node_start_pfn)
118		pgdat->node_start_pfn = start_pfn;
119
120	pgdat->node_spanned_pages = max(old_pgdat_end_pfn, end_pfn) -
121					pgdat->node_start_pfn;
122}
123
124int online_pages(unsigned long pfn, unsigned long nr_pages)
125{
126	unsigned long i;
127	unsigned long flags;
128	unsigned long onlined_pages = 0;
129	struct zone *zone;
130	int need_zonelists_rebuild = 0;
131
132	/*
133	 * This doesn't need a lock to do pfn_to_page().
134	 * The section can't be removed here because of the
135	 * memory_block->state_sem.
136	 */
137	zone = page_zone(pfn_to_page(pfn));
138	pgdat_resize_lock(zone->zone_pgdat, &flags);
139	grow_zone_span(zone, pfn, pfn + nr_pages);
140	grow_pgdat_span(zone->zone_pgdat, pfn, pfn + nr_pages);
141	pgdat_resize_unlock(zone->zone_pgdat, &flags);
142
143	/*
144	 * If this zone is not populated, then it is not in zonelist.
145	 * This means the page allocator ignores this zone.
146	 * So, zonelist must be updated after online.
147	 */
148	if (!populated_zone(zone))
149		need_zonelists_rebuild = 1;
150
151	for (i = 0; i < nr_pages; i++) {
152		struct page *page = pfn_to_page(pfn + i);
153		online_page(page);
154		onlined_pages++;
155	}
156	zone->present_pages += onlined_pages;
157	zone->zone_pgdat->node_present_pages += onlined_pages;
158
159	setup_per_zone_pages_min();
160
161	if (need_zonelists_rebuild)
162		build_all_zonelists();
163
164	return 0;
165}
166