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 } 143