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/writeback.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 #include <linux/ioport.h> 25 #include <linux/cpuset.h> 26 27 #include <asm/tlbflush.h> 28 29 /* add this memory to iomem resource */ 30 static struct resource *register_memory_resource(u64 start, u64 size) 31 { 32 struct resource *res; 33 res = kzalloc(sizeof(struct resource), GFP_KERNEL); 34 BUG_ON(!res); 35 36 res->name = "System RAM"; 37 res->start = start; 38 res->end = start + size - 1; 39 res->flags = IORESOURCE_MEM; 40 if (request_resource(&iomem_resource, res) < 0) { 41 printk("System RAM resource %llx - %llx cannot be added\n", 42 (unsigned long long)res->start, (unsigned long long)res->end); 43 kfree(res); 44 res = NULL; 45 } 46 return res; 47 } 48 49 static void release_memory_resource(struct resource *res) 50 { 51 if (!res) 52 return; 53 release_resource(res); 54 kfree(res); 55 return; 56 } 57 58 59 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE 60 static int __add_zone(struct zone *zone, unsigned long phys_start_pfn) 61 { 62 struct pglist_data *pgdat = zone->zone_pgdat; 63 int nr_pages = PAGES_PER_SECTION; 64 int nid = pgdat->node_id; 65 int zone_type; 66 67 zone_type = zone - pgdat->node_zones; 68 if (!populated_zone(zone)) { 69 int ret = 0; 70 ret = init_currently_empty_zone(zone, phys_start_pfn, nr_pages); 71 if (ret < 0) 72 return ret; 73 } 74 memmap_init_zone(nr_pages, nid, zone_type, phys_start_pfn); 75 return 0; 76 } 77 78 static int __add_section(struct zone *zone, unsigned long phys_start_pfn) 79 { 80 int nr_pages = PAGES_PER_SECTION; 81 int ret; 82 83 if (pfn_valid(phys_start_pfn)) 84 return -EEXIST; 85 86 ret = sparse_add_one_section(zone, phys_start_pfn, nr_pages); 87 88 if (ret < 0) 89 return ret; 90 91 ret = __add_zone(zone, phys_start_pfn); 92 93 if (ret < 0) 94 return ret; 95 96 return register_new_memory(__pfn_to_section(phys_start_pfn)); 97 } 98 99 /* 100 * Reasonably generic function for adding memory. It is 101 * expected that archs that support memory hotplug will 102 * call this function after deciding the zone to which to 103 * add the new pages. 104 */ 105 int __add_pages(struct zone *zone, unsigned long phys_start_pfn, 106 unsigned long nr_pages) 107 { 108 unsigned long i; 109 int err = 0; 110 int start_sec, end_sec; 111 /* during initialize mem_map, align hot-added range to section */ 112 start_sec = pfn_to_section_nr(phys_start_pfn); 113 end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1); 114 115 for (i = start_sec; i <= end_sec; i++) { 116 err = __add_section(zone, i << PFN_SECTION_SHIFT); 117 118 /* 119 * EEXIST is finally dealed with by ioresource collision 120 * check. see add_memory() => register_memory_resource() 121 * Warning will be printed if there is collision. 122 */ 123 if (err && (err != -EEXIST)) 124 break; 125 err = 0; 126 } 127 128 return err; 129 } 130 EXPORT_SYMBOL_GPL(__add_pages); 131 132 static void grow_zone_span(struct zone *zone, 133 unsigned long start_pfn, unsigned long end_pfn) 134 { 135 unsigned long old_zone_end_pfn; 136 137 zone_span_writelock(zone); 138 139 old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages; 140 if (start_pfn < zone->zone_start_pfn) 141 zone->zone_start_pfn = start_pfn; 142 143 zone->spanned_pages = max(old_zone_end_pfn, end_pfn) - 144 zone->zone_start_pfn; 145 146 zone_span_writeunlock(zone); 147 } 148 149 static void grow_pgdat_span(struct pglist_data *pgdat, 150 unsigned long start_pfn, unsigned long end_pfn) 151 { 152 unsigned long old_pgdat_end_pfn = 153 pgdat->node_start_pfn + pgdat->node_spanned_pages; 154 155 if (start_pfn < pgdat->node_start_pfn) 156 pgdat->node_start_pfn = start_pfn; 157 158 pgdat->node_spanned_pages = max(old_pgdat_end_pfn, end_pfn) - 159 pgdat->node_start_pfn; 160 } 161 162 int online_pages(unsigned long pfn, unsigned long nr_pages) 163 { 164 unsigned long i; 165 unsigned long flags; 166 unsigned long onlined_pages = 0; 167 struct resource res; 168 u64 section_end; 169 unsigned long start_pfn; 170 struct zone *zone; 171 int need_zonelists_rebuild = 0; 172 173 /* 174 * This doesn't need a lock to do pfn_to_page(). 175 * The section can't be removed here because of the 176 * memory_block->state_sem. 177 */ 178 zone = page_zone(pfn_to_page(pfn)); 179 pgdat_resize_lock(zone->zone_pgdat, &flags); 180 grow_zone_span(zone, pfn, pfn + nr_pages); 181 grow_pgdat_span(zone->zone_pgdat, pfn, pfn + nr_pages); 182 pgdat_resize_unlock(zone->zone_pgdat, &flags); 183 184 /* 185 * If this zone is not populated, then it is not in zonelist. 186 * This means the page allocator ignores this zone. 187 * So, zonelist must be updated after online. 188 */ 189 if (!populated_zone(zone)) 190 need_zonelists_rebuild = 1; 191 192 res.start = (u64)pfn << PAGE_SHIFT; 193 res.end = res.start + ((u64)nr_pages << PAGE_SHIFT) - 1; 194 res.flags = IORESOURCE_MEM; /* we just need system ram */ 195 section_end = res.end; 196 197 while ((res.start < res.end) && (find_next_system_ram(&res) >= 0)) { 198 start_pfn = (unsigned long)(res.start >> PAGE_SHIFT); 199 nr_pages = (unsigned long) 200 ((res.end + 1 - res.start) >> PAGE_SHIFT); 201 202 if (PageReserved(pfn_to_page(start_pfn))) { 203 /* this region's page is not onlined now */ 204 for (i = 0; i < nr_pages; i++) { 205 struct page *page = pfn_to_page(start_pfn + i); 206 online_page(page); 207 onlined_pages++; 208 } 209 } 210 211 res.start = res.end + 1; 212 res.end = section_end; 213 } 214 zone->present_pages += onlined_pages; 215 zone->zone_pgdat->node_present_pages += onlined_pages; 216 217 setup_per_zone_pages_min(); 218 219 if (need_zonelists_rebuild) 220 build_all_zonelists(); 221 vm_total_pages = nr_free_pagecache_pages(); 222 writeback_set_ratelimit(); 223 return 0; 224 } 225 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ 226 227 static pg_data_t *hotadd_new_pgdat(int nid, u64 start) 228 { 229 struct pglist_data *pgdat; 230 unsigned long zones_size[MAX_NR_ZONES] = {0}; 231 unsigned long zholes_size[MAX_NR_ZONES] = {0}; 232 unsigned long start_pfn = start >> PAGE_SHIFT; 233 234 pgdat = arch_alloc_nodedata(nid); 235 if (!pgdat) 236 return NULL; 237 238 arch_refresh_nodedata(nid, pgdat); 239 240 /* we can use NODE_DATA(nid) from here */ 241 242 /* init node's zones as empty zones, we don't have any present pages.*/ 243 free_area_init_node(nid, pgdat, zones_size, start_pfn, zholes_size); 244 245 return pgdat; 246 } 247 248 static void rollback_node_hotadd(int nid, pg_data_t *pgdat) 249 { 250 arch_refresh_nodedata(nid, NULL); 251 arch_free_nodedata(pgdat); 252 return; 253 } 254 255 256 int add_memory(int nid, u64 start, u64 size) 257 { 258 pg_data_t *pgdat = NULL; 259 int new_pgdat = 0; 260 struct resource *res; 261 int ret; 262 263 res = register_memory_resource(start, size); 264 if (!res) 265 return -EEXIST; 266 267 if (!node_online(nid)) { 268 pgdat = hotadd_new_pgdat(nid, start); 269 if (!pgdat) 270 return -ENOMEM; 271 new_pgdat = 1; 272 ret = kswapd_run(nid); 273 if (ret) 274 goto error; 275 } 276 277 /* call arch's memory hotadd */ 278 ret = arch_add_memory(nid, start, size); 279 280 if (ret < 0) 281 goto error; 282 283 /* we online node here. we can't roll back from here. */ 284 node_set_online(nid); 285 286 cpuset_track_online_nodes(); 287 288 if (new_pgdat) { 289 ret = register_one_node(nid); 290 /* 291 * If sysfs file of new node can't create, cpu on the node 292 * can't be hot-added. There is no rollback way now. 293 * So, check by BUG_ON() to catch it reluctantly.. 294 */ 295 BUG_ON(ret); 296 } 297 298 return ret; 299 error: 300 /* rollback pgdat allocation and others */ 301 if (new_pgdat) 302 rollback_node_hotadd(nid, pgdat); 303 if (res) 304 release_memory_resource(res); 305 306 return ret; 307 } 308 EXPORT_SYMBOL_GPL(add_memory); 309