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