memory_hotplug.c revision 0b0acbec1bed75ec1e1daa7f7006323a2a2b2844 
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 void __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	memmap_init_zone(nr_pages, nid, zone_type, phys_start_pfn);
38	zonetable_add(zone, nid, zone_type, phys_start_pfn, nr_pages);
39}
40
41extern int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
42				  int nr_pages);
43static int __add_section(struct zone *zone, unsigned long phys_start_pfn)
44{
45	struct pglist_data *pgdat = zone->zone_pgdat;
46	int nr_pages = PAGES_PER_SECTION;
47	int ret;
48
49	ret = sparse_add_one_section(zone, phys_start_pfn, nr_pages);
50
51	if (ret < 0)
52		return ret;
53
54	__add_zone(zone, phys_start_pfn);
55	return register_new_memory(__pfn_to_section(phys_start_pfn));
56}
57
58/*
59 * Reasonably generic function for adding memory.  It is
60 * expected that archs that support memory hotplug will
61 * call this function after deciding the zone to which to
62 * add the new pages.
63 */
64int __add_pages(struct zone *zone, unsigned long phys_start_pfn,
65		 unsigned long nr_pages)
66{
67	unsigned long i;
68	int err = 0;
69
70	for (i = 0; i < nr_pages; i += PAGES_PER_SECTION) {
71		err = __add_section(zone, phys_start_pfn + i);
72
73		if (err)
74			break;
75	}
76
77	return err;
78}
79
80static void grow_zone_span(struct zone *zone,
81		unsigned long start_pfn, unsigned long end_pfn)
82{
83	unsigned long old_zone_end_pfn;
84
85	zone_span_writelock(zone);
86
87	old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages;
88	if (start_pfn < zone->zone_start_pfn)
89		zone->zone_start_pfn = start_pfn;
90
91	if (end_pfn > old_zone_end_pfn)
92		zone->spanned_pages = end_pfn - zone->zone_start_pfn;
93
94	zone_span_writeunlock(zone);
95}
96
97static void grow_pgdat_span(struct pglist_data *pgdat,
98		unsigned long start_pfn, unsigned long end_pfn)
99{
100	unsigned long old_pgdat_end_pfn =
101		pgdat->node_start_pfn + pgdat->node_spanned_pages;
102
103	if (start_pfn < pgdat->node_start_pfn)
104		pgdat->node_start_pfn = start_pfn;
105
106	if (end_pfn > old_pgdat_end_pfn)
107		pgdat->node_spanned_pages = end_pfn - pgdat->node_spanned_pages;
108}
109
110int online_pages(unsigned long pfn, unsigned long nr_pages)
111{
112	unsigned long i;
113	unsigned long flags;
114	unsigned long onlined_pages = 0;
115	struct zone *zone;
116
117	/*
118	 * This doesn't need a lock to do pfn_to_page().
119	 * The section can't be removed here because of the
120	 * memory_block->state_sem.
121	 */
122	zone = page_zone(pfn_to_page(pfn));
123	pgdat_resize_lock(zone->zone_pgdat, &flags);
124	grow_zone_span(zone, pfn, pfn + nr_pages);
125	grow_pgdat_span(zone->zone_pgdat, pfn, pfn + nr_pages);
126	pgdat_resize_unlock(zone->zone_pgdat, &flags);
127
128	for (i = 0; i < nr_pages; i++) {
129		struct page *page = pfn_to_page(pfn + i);
130		online_page(page);
131		onlined_pages++;
132	}
133	zone->present_pages += onlined_pages;
134
135	return 0;
136}
137