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 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                 /* We want to keep adding the rest of the
  73                  * sections if the first ones already exist
  74                  */
  75                 if (err && (err != -EEXIST))
  76                         break;
  77         }
  78
  79         return err;
  80 }
  81 EXPORT_SYMBOL_GPL(__add_pages);
  82
  83 static void grow_zone_span(struct zone *zone,
  84                 unsigned long start_pfn, unsigned long end_pfn)
  85 {
  86         unsigned long old_zone_end_pfn;
  87
  88         zone_span_writelock(zone);
  89
  90         old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages;
  91         if (start_pfn < zone->zone_start_pfn)
  92                 zone->zone_start_pfn = start_pfn;
  93
  94         zone->spanned_pages = max(old_zone_end_pfn, end_pfn) -
  95                                 zone->zone_start_pfn;
  96
  97         zone_span_writeunlock(zone);
  98 }
  99
 100 static void grow_pgdat_span(struct pglist_data *pgdat,
 101                 unsigned long start_pfn, unsigned long end_pfn)
 102 {
 103         unsigned long old_pgdat_end_pfn =
 104                 pgdat->node_start_pfn + pgdat->node_spanned_pages;
 105
 106         if (start_pfn < pgdat->node_start_pfn)
 107                 pgdat->node_start_pfn = start_pfn;
 108
 109         pgdat->node_spanned_pages = max(old_pgdat_end_pfn, end_pfn) -
 110                                         pgdat->node_start_pfn;
 111 }
 112
 113 int online_pages(unsigned long pfn, unsigned long nr_pages)
 114 {
 115         unsigned long i;
 116         unsigned long flags;
 117         unsigned long onlined_pages = 0;
 118         struct zone *zone;
 119
 120         /*
 121          * This doesn't need a lock to do pfn_to_page().
 122          * The section can't be removed here because of the
 123          * memory_block->state_sem.
 124          */
 125         zone = page_zone(pfn_to_page(pfn));
 126         pgdat_resize_lock(zone->zone_pgdat, &flags);
 127         grow_zone_span(zone, pfn, pfn + nr_pages);
 128         grow_pgdat_span(zone->zone_pgdat, pfn, pfn + nr_pages);
 129         pgdat_resize_unlock(zone->zone_pgdat, &flags);
 130
 131         for (i = 0; i < nr_pages; i++) {
 132                 struct page *page = pfn_to_page(pfn + i);
 133                 online_page(page);
 134                 onlined_pages++;
 135         }
 136         zone->present_pages += onlined_pages;
 137         zone->zone_pgdat->node_present_pages += onlined_pages;
 138
 139         setup_per_zone_pages_min();
 140
 141         return 0;
 142 }