xref: /openbmc/linux/mm/memory_hotplug.c (revision 87c2ce3b) 
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 	int nr_pages = PAGES_PER_SECTION;
46 	int ret;
47 
48 	ret = sparse_add_one_section(zone, phys_start_pfn, nr_pages);
49 
50 	if (ret < 0)
51 		return ret;
52 
53 	__add_zone(zone, phys_start_pfn);
54 	return register_new_memory(__pfn_to_section(phys_start_pfn));
55 }
56 
57 /*
58  * Reasonably generic function for adding memory.  It is
59  * expected that archs that support memory hotplug will
60  * call this function after deciding the zone to which to
61  * add the new pages.
62  */
63 int __add_pages(struct zone *zone, unsigned long phys_start_pfn,
64 		 unsigned long nr_pages)
65 {
66 	unsigned long i;
67 	int err = 0;
68 
69 	for (i = 0; i < nr_pages; i += PAGES_PER_SECTION) {
70 		err = __add_section(zone, phys_start_pfn + i);
71 
72 		if (err)
73 			break;
74 	}
75 
76 	return err;
77 }
78 
79 static void grow_zone_span(struct zone *zone,
80 		unsigned long start_pfn, unsigned long end_pfn)
81 {
82 	unsigned long old_zone_end_pfn;
83 
84 	zone_span_writelock(zone);
85 
86 	old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages;
87 	if (start_pfn < zone->zone_start_pfn)
88 		zone->zone_start_pfn = start_pfn;
89 
90 	if (end_pfn > old_zone_end_pfn)
91 		zone->spanned_pages = end_pfn - zone->zone_start_pfn;
92 
93 	zone_span_writeunlock(zone);
94 }
95 
96 static void grow_pgdat_span(struct pglist_data *pgdat,
97 		unsigned long start_pfn, unsigned long end_pfn)
98 {
99 	unsigned long old_pgdat_end_pfn =
100 		pgdat->node_start_pfn + pgdat->node_spanned_pages;
101 
102 	if (start_pfn < pgdat->node_start_pfn)
103 		pgdat->node_start_pfn = start_pfn;
104 
105 	if (end_pfn > old_pgdat_end_pfn)
106 		pgdat->node_spanned_pages = end_pfn - pgdat->node_start_pfn;
107 }
108 
109 int online_pages(unsigned long pfn, unsigned long nr_pages)
110 {
111 	unsigned long i;
112 	unsigned long flags;
113 	unsigned long onlined_pages = 0;
114 	struct zone *zone;
115 
116 	/*
117 	 * This doesn't need a lock to do pfn_to_page().
118 	 * The section can't be removed here because of the
119 	 * memory_block->state_sem.
120 	 */
121 	zone = page_zone(pfn_to_page(pfn));
122 	pgdat_resize_lock(zone->zone_pgdat, &flags);
123 	grow_zone_span(zone, pfn, pfn + nr_pages);
124 	grow_pgdat_span(zone->zone_pgdat, pfn, pfn + nr_pages);
125 	pgdat_resize_unlock(zone->zone_pgdat, &flags);
126 
127 	for (i = 0; i < nr_pages; i++) {
128 		struct page *page = pfn_to_page(pfn + i);
129 		online_page(page);
130 		onlined_pages++;
131 	}
132 	zone->present_pages += onlined_pages;
133 
134 	setup_per_zone_pages_min();
135 
136 	return 0;
137 }
138