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