xref: /openbmc/linux/mm/memory_hotplug.c (revision d5cb9783536a41df9f9cba5b0a1d78047ed787f7)
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 
27 extern void zonetable_add(struct zone *zone, int nid, int zid, unsigned long pfn,
28 			  unsigned long size);
29 static 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 
41 extern int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
42 				  int nr_pages);
43 static 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  */
64 int __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 
80 static 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 
97 static 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 
110 int 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 	setup_per_zone_pages_min();
136 
137 	return 0;
138 }
139