mm/memory_hotplug.c

   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 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
  48 extern int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
  49                                   int nr_pages);
  50 static 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  */
  74 int __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 }
  92 EXPORT_SYMBOL_GPL(__add_pages);
  93
  94 static 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
 111 static 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
 124 int 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 }