1 /* 2 * linux/mm/memory_hotplug.c 3 * 4 * Copyright (C) 5 */ 6 7 #include <linux/stddef.h> 8 #include <linux/mm.h> 9 #include <linux/swap.h> 10 #include <linux/interrupt.h> 11 #include <linux/pagemap.h> 12 #include <linux/bootmem.h> 13 #include <linux/compiler.h> 14 #include <linux/module.h> 15 #include <linux/pagevec.h> 16 #include <linux/slab.h> 17 #include <linux/sysctl.h> 18 #include <linux/cpu.h> 19 #include <linux/memory.h> 20 #include <linux/memory_hotplug.h> 21 #include <linux/highmem.h> 22 #include <linux/vmalloc.h> 23 #include <linux/ioport.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 resource res; 130 u64 section_end; 131 unsigned long start_pfn; 132 struct zone *zone; 133 int need_zonelists_rebuild = 0; 134 135 /* 136 * This doesn't need a lock to do pfn_to_page(). 137 * The section can't be removed here because of the 138 * memory_block->state_sem. 139 */ 140 zone = page_zone(pfn_to_page(pfn)); 141 pgdat_resize_lock(zone->zone_pgdat, &flags); 142 grow_zone_span(zone, pfn, pfn + nr_pages); 143 grow_pgdat_span(zone->zone_pgdat, pfn, pfn + nr_pages); 144 pgdat_resize_unlock(zone->zone_pgdat, &flags); 145 146 /* 147 * If this zone is not populated, then it is not in zonelist. 148 * This means the page allocator ignores this zone. 149 * So, zonelist must be updated after online. 150 */ 151 if (!populated_zone(zone)) 152 need_zonelists_rebuild = 1; 153 154 res.start = (u64)pfn << PAGE_SHIFT; 155 res.end = res.start + ((u64)nr_pages << PAGE_SHIFT) - 1; 156 res.flags = IORESOURCE_MEM; /* we just need system ram */ 157 section_end = res.end; 158 159 while (find_next_system_ram(&res) >= 0) { 160 start_pfn = (unsigned long)(res.start >> PAGE_SHIFT); 161 nr_pages = (unsigned long) 162 ((res.end + 1 - res.start) >> PAGE_SHIFT); 163 164 if (PageReserved(pfn_to_page(start_pfn))) { 165 /* this region's page is not onlined now */ 166 for (i = 0; i < nr_pages; i++) { 167 struct page *page = pfn_to_page(start_pfn + i); 168 online_page(page); 169 onlined_pages++; 170 } 171 } 172 173 res.start = res.end + 1; 174 res.end = section_end; 175 } 176 zone->present_pages += onlined_pages; 177 zone->zone_pgdat->node_present_pages += onlined_pages; 178 179 setup_per_zone_pages_min(); 180 181 if (need_zonelists_rebuild) 182 build_all_zonelists(); 183 vm_total_pages = nr_free_pagecache_pages(); 184 return 0; 185 } 186 187 static pg_data_t *hotadd_new_pgdat(int nid, u64 start) 188 { 189 struct pglist_data *pgdat; 190 unsigned long zones_size[MAX_NR_ZONES] = {0}; 191 unsigned long zholes_size[MAX_NR_ZONES] = {0}; 192 unsigned long start_pfn = start >> PAGE_SHIFT; 193 194 pgdat = arch_alloc_nodedata(nid); 195 if (!pgdat) 196 return NULL; 197 198 arch_refresh_nodedata(nid, pgdat); 199 200 /* we can use NODE_DATA(nid) from here */ 201 202 /* init node's zones as empty zones, we don't have any present pages.*/ 203 free_area_init_node(nid, pgdat, zones_size, start_pfn, zholes_size); 204 205 return pgdat; 206 } 207 208 static void rollback_node_hotadd(int nid, pg_data_t *pgdat) 209 { 210 arch_refresh_nodedata(nid, NULL); 211 arch_free_nodedata(pgdat); 212 return; 213 } 214 215 /* add this memory to iomem resource */ 216 static void register_memory_resource(u64 start, u64 size) 217 { 218 struct resource *res; 219 220 res = kzalloc(sizeof(struct resource), GFP_KERNEL); 221 BUG_ON(!res); 222 223 res->name = "System RAM"; 224 res->start = start; 225 res->end = start + size - 1; 226 res->flags = IORESOURCE_MEM; 227 if (request_resource(&iomem_resource, res) < 0) { 228 printk("System RAM resource %llx - %llx cannot be added\n", 229 (unsigned long long)res->start, (unsigned long long)res->end); 230 kfree(res); 231 } 232 } 233 234 235 236 int add_memory(int nid, u64 start, u64 size) 237 { 238 pg_data_t *pgdat = NULL; 239 int new_pgdat = 0; 240 int ret; 241 242 if (!node_online(nid)) { 243 pgdat = hotadd_new_pgdat(nid, start); 244 if (!pgdat) 245 return -ENOMEM; 246 new_pgdat = 1; 247 ret = kswapd_run(nid); 248 if (ret) 249 goto error; 250 } 251 252 /* call arch's memory hotadd */ 253 ret = arch_add_memory(nid, start, size); 254 255 if (ret < 0) 256 goto error; 257 258 /* we online node here. we can't roll back from here. */ 259 node_set_online(nid); 260 261 if (new_pgdat) { 262 ret = register_one_node(nid); 263 /* 264 * If sysfs file of new node can't create, cpu on the node 265 * can't be hot-added. There is no rollback way now. 266 * So, check by BUG_ON() to catch it reluctantly.. 267 */ 268 BUG_ON(ret); 269 } 270 271 /* register this memory as resource */ 272 register_memory_resource(start, size); 273 274 return ret; 275 error: 276 /* rollback pgdat allocation and others */ 277 if (new_pgdat) 278 rollback_node_hotadd(nid, pgdat); 279 280 return ret; 281 } 282 EXPORT_SYMBOL_GPL(add_memory); 283