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 (!zone->wait_table) { 69 int ret = 0; 70 ret = init_currently_empty_zone(zone, phys_start_pfn, 71 nr_pages, MEMMAP_HOTPLUG); 72 if (ret < 0) 73 return ret; 74 } 75 memmap_init_zone(nr_pages, nid, zone_type, 76 phys_start_pfn, MEMMAP_HOTPLUG); 77 return 0; 78 } 79 80 static int __add_section(struct zone *zone, unsigned long phys_start_pfn) 81 { 82 int nr_pages = PAGES_PER_SECTION; 83 int ret; 84 85 if (pfn_valid(phys_start_pfn)) 86 return -EEXIST; 87 88 ret = sparse_add_one_section(zone, phys_start_pfn, nr_pages); 89 90 if (ret < 0) 91 return ret; 92 93 ret = __add_zone(zone, phys_start_pfn); 94 95 if (ret < 0) 96 return ret; 97 98 return register_new_memory(__pfn_to_section(phys_start_pfn)); 99 } 100 101 /* 102 * Reasonably generic function for adding memory. It is 103 * expected that archs that support memory hotplug will 104 * call this function after deciding the zone to which to 105 * add the new pages. 106 */ 107 int __add_pages(struct zone *zone, unsigned long phys_start_pfn, 108 unsigned long nr_pages) 109 { 110 unsigned long i; 111 int err = 0; 112 int start_sec, end_sec; 113 /* during initialize mem_map, align hot-added range to section */ 114 start_sec = pfn_to_section_nr(phys_start_pfn); 115 end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1); 116 117 for (i = start_sec; i <= end_sec; i++) { 118 err = __add_section(zone, i << PFN_SECTION_SHIFT); 119 120 /* 121 * EEXIST is finally dealed with by ioresource collision 122 * check. see add_memory() => register_memory_resource() 123 * Warning will be printed if there is collision. 124 */ 125 if (err && (err != -EEXIST)) 126 break; 127 err = 0; 128 } 129 130 return err; 131 } 132 EXPORT_SYMBOL_GPL(__add_pages); 133 134 static void grow_zone_span(struct zone *zone, 135 unsigned long start_pfn, unsigned long end_pfn) 136 { 137 unsigned long old_zone_end_pfn; 138 139 zone_span_writelock(zone); 140 141 old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages; 142 if (start_pfn < zone->zone_start_pfn) 143 zone->zone_start_pfn = start_pfn; 144 145 zone->spanned_pages = max(old_zone_end_pfn, end_pfn) - 146 zone->zone_start_pfn; 147 148 zone_span_writeunlock(zone); 149 } 150 151 static void grow_pgdat_span(struct pglist_data *pgdat, 152 unsigned long start_pfn, unsigned long end_pfn) 153 { 154 unsigned long old_pgdat_end_pfn = 155 pgdat->node_start_pfn + pgdat->node_spanned_pages; 156 157 if (start_pfn < pgdat->node_start_pfn) 158 pgdat->node_start_pfn = start_pfn; 159 160 pgdat->node_spanned_pages = max(old_pgdat_end_pfn, end_pfn) - 161 pgdat->node_start_pfn; 162 } 163 164 int online_pages(unsigned long pfn, unsigned long nr_pages) 165 { 166 unsigned long i; 167 unsigned long flags; 168 unsigned long onlined_pages = 0; 169 struct resource res; 170 u64 section_end; 171 unsigned long start_pfn; 172 struct zone *zone; 173 int need_zonelists_rebuild = 0; 174 175 /* 176 * This doesn't need a lock to do pfn_to_page(). 177 * The section can't be removed here because of the 178 * memory_block->state_sem. 179 */ 180 zone = page_zone(pfn_to_page(pfn)); 181 pgdat_resize_lock(zone->zone_pgdat, &flags); 182 grow_zone_span(zone, pfn, pfn + nr_pages); 183 grow_pgdat_span(zone->zone_pgdat, pfn, pfn + nr_pages); 184 pgdat_resize_unlock(zone->zone_pgdat, &flags); 185 186 /* 187 * If this zone is not populated, then it is not in zonelist. 188 * This means the page allocator ignores this zone. 189 * So, zonelist must be updated after online. 190 */ 191 if (!populated_zone(zone)) 192 need_zonelists_rebuild = 1; 193 194 res.start = (u64)pfn << PAGE_SHIFT; 195 res.end = res.start + ((u64)nr_pages << PAGE_SHIFT) - 1; 196 res.flags = IORESOURCE_MEM; /* we just need system ram */ 197 section_end = res.end; 198 199 while ((res.start < res.end) && (find_next_system_ram(&res) >= 0)) { 200 start_pfn = (unsigned long)(res.start >> PAGE_SHIFT); 201 nr_pages = (unsigned long) 202 ((res.end + 1 - res.start) >> PAGE_SHIFT); 203 204 if (PageReserved(pfn_to_page(start_pfn))) { 205 /* this region's page is not onlined now */ 206 for (i = 0; i < nr_pages; i++) { 207 struct page *page = pfn_to_page(start_pfn + i); 208 online_page(page); 209 onlined_pages++; 210 } 211 } 212 213 res.start = res.end + 1; 214 res.end = section_end; 215 } 216 zone->present_pages += onlined_pages; 217 zone->zone_pgdat->node_present_pages += onlined_pages; 218 219 setup_per_zone_pages_min(); 220 221 if (need_zonelists_rebuild) 222 build_all_zonelists(); 223 vm_total_pages = nr_free_pagecache_pages(); 224 writeback_set_ratelimit(); 225 return 0; 226 } 227 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ 228 229 static pg_data_t *hotadd_new_pgdat(int nid, u64 start) 230 { 231 struct pglist_data *pgdat; 232 unsigned long zones_size[MAX_NR_ZONES] = {0}; 233 unsigned long zholes_size[MAX_NR_ZONES] = {0}; 234 unsigned long start_pfn = start >> PAGE_SHIFT; 235 236 pgdat = arch_alloc_nodedata(nid); 237 if (!pgdat) 238 return NULL; 239 240 arch_refresh_nodedata(nid, pgdat); 241 242 /* we can use NODE_DATA(nid) from here */ 243 244 /* init node's zones as empty zones, we don't have any present pages.*/ 245 free_area_init_node(nid, pgdat, zones_size, start_pfn, zholes_size); 246 247 return pgdat; 248 } 249 250 static void rollback_node_hotadd(int nid, pg_data_t *pgdat) 251 { 252 arch_refresh_nodedata(nid, NULL); 253 arch_free_nodedata(pgdat); 254 return; 255 } 256 257 258 int add_memory(int nid, u64 start, u64 size) 259 { 260 pg_data_t *pgdat = NULL; 261 int new_pgdat = 0; 262 struct resource *res; 263 int ret; 264 265 res = register_memory_resource(start, size); 266 if (!res) 267 return -EEXIST; 268 269 if (!node_online(nid)) { 270 pgdat = hotadd_new_pgdat(nid, start); 271 if (!pgdat) 272 return -ENOMEM; 273 new_pgdat = 1; 274 ret = kswapd_run(nid); 275 if (ret) 276 goto error; 277 } 278 279 /* call arch's memory hotadd */ 280 ret = arch_add_memory(nid, start, size); 281 282 if (ret < 0) 283 goto error; 284 285 /* we online node here. we can't roll back from here. */ 286 node_set_online(nid); 287 288 cpuset_track_online_nodes(); 289 290 if (new_pgdat) { 291 ret = register_one_node(nid); 292 /* 293 * If sysfs file of new node can't create, cpu on the node 294 * can't be hot-added. There is no rollback way now. 295 * So, check by BUG_ON() to catch it reluctantly.. 296 */ 297 BUG_ON(ret); 298 } 299 300 return ret; 301 error: 302 /* rollback pgdat allocation and others */ 303 if (new_pgdat) 304 rollback_node_hotadd(nid, pgdat); 305 if (res) 306 release_memory_resource(res); 307 308 return ret; 309 } 310 EXPORT_SYMBOL_GPL(add_memory); 311