drivers/base/node.c

   1 /*
   2  * Basic Node interface support
   3  */
   4
   5 #include <linux/module.h>
   6 #include <linux/init.h>
   7 #include <linux/mm.h>
   8 #include <linux/memory.h>
   9 #include <linux/vmstat.h>
  10 #include <linux/notifier.h>
  11 #include <linux/node.h>
  12 #include <linux/hugetlb.h>
  13 #include <linux/compaction.h>
  14 #include <linux/cpumask.h>
  15 #include <linux/topology.h>
  16 #include <linux/nodemask.h>
  17 #include <linux/cpu.h>
  18 #include <linux/device.h>
  19 #include <linux/swap.h>
  20 #include <linux/slab.h>
  21
  22 static struct bus_type node_subsys = {
  23         .name = "node",
  24         .dev_name = "node",
  25 };
  26
  27
  28 static ssize_t node_read_cpumap(struct device *dev, int type, char *buf)
  29 {
  30         struct node *node_dev = to_node(dev);
  31         const struct cpumask *mask = cpumask_of_node(node_dev->dev.id);
  32         int len;
  33
  34         /* 2008/04/07: buf currently PAGE_SIZE, need 9 chars per 32 bits. */
  35         BUILD_BUG_ON((NR_CPUS/32 * 9) > (PAGE_SIZE-1));
  36
  37         len = type?
  38                 cpulist_scnprintf(buf, PAGE_SIZE-2, mask) :
  39                 cpumask_scnprintf(buf, PAGE_SIZE-2, mask);
  40         buf[len++] = '\n';
  41         buf[len] = '\0';
  42         return len;
  43 }
  44
  45 static inline ssize_t node_read_cpumask(struct device *dev,
  46                                 struct device_attribute *attr, char *buf)
  47 {
  48         return node_read_cpumap(dev, 0, buf);
  49 }
  50 static inline ssize_t node_read_cpulist(struct device *dev,
  51                                 struct device_attribute *attr, char *buf)
  52 {
  53         return node_read_cpumap(dev, 1, buf);
  54 }
  55
  56 static DEVICE_ATTR(cpumap,  S_IRUGO, node_read_cpumask, NULL);
  57 static DEVICE_ATTR(cpulist, S_IRUGO, node_read_cpulist, NULL);
  58
  59 #define K(x) ((x) << (PAGE_SHIFT - 10))
  60 static ssize_t node_read_meminfo(struct device *dev,
  61                         struct device_attribute *attr, char *buf)
  62 {
  63         int n;
  64         int nid = dev->id;
  65         struct sysinfo i;
  66
  67         si_meminfo_node(&i, nid);
  68         n = sprintf(buf,
  69                        "Node %d MemTotal:       %8lu kB\n"
  70                        "Node %d MemFree:        %8lu kB\n"
  71                        "Node %d MemUsed:        %8lu kB\n"
  72                        "Node %d Active:         %8lu kB\n"
  73                        "Node %d Inactive:       %8lu kB\n"
  74                        "Node %d Active(anon):   %8lu kB\n"
  75                        "Node %d Inactive(anon): %8lu kB\n"
  76                        "Node %d Active(file):   %8lu kB\n"
  77                        "Node %d Inactive(file): %8lu kB\n"
  78                        "Node %d Unevictable:    %8lu kB\n"
  79                        "Node %d Mlocked:        %8lu kB\n",
  80                        nid, K(i.totalram),
  81                        nid, K(i.freeram),
  82                        nid, K(i.totalram - i.freeram),
  83                        nid, K(node_page_state(nid, NR_ACTIVE_ANON) +
  84                                 node_page_state(nid, NR_ACTIVE_FILE)),
  85                        nid, K(node_page_state(nid, NR_INACTIVE_ANON) +
  86                                 node_page_state(nid, NR_INACTIVE_FILE)),
  87                        nid, K(node_page_state(nid, NR_ACTIVE_ANON)),
  88                        nid, K(node_page_state(nid, NR_INACTIVE_ANON)),
  89                        nid, K(node_page_state(nid, NR_ACTIVE_FILE)),
  90                        nid, K(node_page_state(nid, NR_INACTIVE_FILE)),
  91                        nid, K(node_page_state(nid, NR_UNEVICTABLE)),
  92                        nid, K(node_page_state(nid, NR_MLOCK)));
  93
  94 #ifdef CONFIG_HIGHMEM
  95         n += sprintf(buf + n,
  96                        "Node %d HighTotal:      %8lu kB\n"
  97                        "Node %d HighFree:       %8lu kB\n"
  98                        "Node %d LowTotal:       %8lu kB\n"
  99                        "Node %d LowFree:        %8lu kB\n",
 100                        nid, K(i.totalhigh),
 101                        nid, K(i.freehigh),
 102                        nid, K(i.totalram - i.totalhigh),
 103                        nid, K(i.freeram - i.freehigh));
 104 #endif
 105         n += sprintf(buf + n,
 106                        "Node %d Dirty:          %8lu kB\n"
 107                        "Node %d Writeback:      %8lu kB\n"
 108                        "Node %d FilePages:      %8lu kB\n"
 109                        "Node %d Mapped:         %8lu kB\n"
 110                        "Node %d AnonPages:      %8lu kB\n"
 111                        "Node %d Shmem:          %8lu kB\n"
 112                        "Node %d KernelStack:    %8lu kB\n"
 113                        "Node %d PageTables:     %8lu kB\n"
 114                        "Node %d NFS_Unstable:   %8lu kB\n"
 115                        "Node %d Bounce:         %8lu kB\n"
 116                        "Node %d WritebackTmp:   %8lu kB\n"
 117                        "Node %d Slab:           %8lu kB\n"
 118                        "Node %d SReclaimable:   %8lu kB\n"
 119                        "Node %d SUnreclaim:     %8lu kB\n"
 120 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 121                        "Node %d AnonHugePages:  %8lu kB\n"
 122 #endif
 123                         ,
 124                        nid, K(node_page_state(nid, NR_FILE_DIRTY)),
 125                        nid, K(node_page_state(nid, NR_WRITEBACK)),
 126                        nid, K(node_page_state(nid, NR_FILE_PAGES)),
 127                        nid, K(node_page_state(nid, NR_FILE_MAPPED)),
 128 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 129                        nid, K(node_page_state(nid, NR_ANON_PAGES)
 130                         + node_page_state(nid, NR_ANON_TRANSPARENT_HUGEPAGES) *
 131                         HPAGE_PMD_NR),
 132 #else
 133                        nid, K(node_page_state(nid, NR_ANON_PAGES)),
 134 #endif
 135                        nid, K(node_page_state(nid, NR_SHMEM)),
 136                        nid, node_page_state(nid, NR_KERNEL_STACK) *
 137                                 THREAD_SIZE / 1024,
 138                        nid, K(node_page_state(nid, NR_PAGETABLE)),
 139                        nid, K(node_page_state(nid, NR_UNSTABLE_NFS)),
 140                        nid, K(node_page_state(nid, NR_BOUNCE)),
 141                        nid, K(node_page_state(nid, NR_WRITEBACK_TEMP)),
 142                        nid, K(node_page_state(nid, NR_SLAB_RECLAIMABLE) +
 143                                 node_page_state(nid, NR_SLAB_UNRECLAIMABLE)),
 144                        nid, K(node_page_state(nid, NR_SLAB_RECLAIMABLE)),
 145 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 146                        nid, K(node_page_state(nid, NR_SLAB_UNRECLAIMABLE))
 147                         , nid,
 148                         K(node_page_state(nid, NR_ANON_TRANSPARENT_HUGEPAGES) *
 149                         HPAGE_PMD_NR));
 150 #else
 151                        nid, K(node_page_state(nid, NR_SLAB_UNRECLAIMABLE)));
 152 #endif
 153         n += hugetlb_report_node_meminfo(nid, buf + n);
 154         return n;
 155 }
 156
 157 #undef K
 158 static DEVICE_ATTR(meminfo, S_IRUGO, node_read_meminfo, NULL);
 159
 160 static ssize_t node_read_numastat(struct device *dev,
 161                                 struct device_attribute *attr, char *buf)
 162 {
 163         return sprintf(buf,
 164                        "numa_hit %lu\n"
 165                        "numa_miss %lu\n"
 166                        "numa_foreign %lu\n"
 167                        "interleave_hit %lu\n"
 168                        "local_node %lu\n"
 169                        "other_node %lu\n",
 170                        node_page_state(dev->id, NUMA_HIT),
 171                        node_page_state(dev->id, NUMA_MISS),
 172                        node_page_state(dev->id, NUMA_FOREIGN),
 173                        node_page_state(dev->id, NUMA_INTERLEAVE_HIT),
 174                        node_page_state(dev->id, NUMA_LOCAL),
 175                        node_page_state(dev->id, NUMA_OTHER));
 176 }
 177 static DEVICE_ATTR(numastat, S_IRUGO, node_read_numastat, NULL);
 178
 179 static ssize_t node_read_vmstat(struct device *dev,
 180                                 struct device_attribute *attr, char *buf)
 181 {
 182         int nid = dev->id;
 183         int i;
 184         int n = 0;
 185
 186         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
 187                 n += sprintf(buf+n, "%s %lu\n", vmstat_text[i],
 188                              node_page_state(nid, i));
 189
 190         return n;
 191 }
 192 static DEVICE_ATTR(vmstat, S_IRUGO, node_read_vmstat, NULL);
 193
 194 static ssize_t node_read_distance(struct device *dev,
 195                         struct device_attribute *attr, char * buf)
 196 {
 197         int nid = dev->id;
 198         int len = 0;
 199         int i;
 200
 201         /*
 202          * buf is currently PAGE_SIZE in length and each node needs 4 chars
 203          * at the most (distance + space or newline).
 204          */
 205         BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE);
 206
 207         for_each_online_node(i)
 208                 len += sprintf(buf + len, "%s%d", i ? " " : "", node_distance(nid, i));
 209
 210         len += sprintf(buf + len, "\n");
 211         return len;
 212 }
 213 static DEVICE_ATTR(distance, S_IRUGO, node_read_distance, NULL);
 214
 215 #ifdef CONFIG_HUGETLBFS
 216 /*
 217  * hugetlbfs per node attributes registration interface:
 218  * When/if hugetlb[fs] subsystem initializes [sometime after this module],
 219  * it will register its per node attributes for all online nodes with
 220  * memory.  It will also call register_hugetlbfs_with_node(), below, to
 221  * register its attribute registration functions with this node driver.
 222  * Once these hooks have been initialized, the node driver will call into
 223  * the hugetlb module to [un]register attributes for hot-plugged nodes.
 224  */
 225 static node_registration_func_t __hugetlb_register_node;
 226 static node_registration_func_t __hugetlb_unregister_node;
 227
 228 static inline bool hugetlb_register_node(struct node *node)
 229 {
 230         if (__hugetlb_register_node &&
 231                         node_state(node->dev.id, N_MEMORY)) {
 232                 __hugetlb_register_node(node);
 233                 return true;
 234         }
 235         return false;
 236 }
 237
 238 static inline void hugetlb_unregister_node(struct node *node)
 239 {
 240         if (__hugetlb_unregister_node)
 241                 __hugetlb_unregister_node(node);
 242 }
 243
 244 void register_hugetlbfs_with_node(node_registration_func_t doregister,
 245                                   node_registration_func_t unregister)
 246 {
 247         __hugetlb_register_node   = doregister;
 248         __hugetlb_unregister_node = unregister;
 249 }
 250 #else
 251 static inline void hugetlb_register_node(struct node *node) {}
 252
 253 static inline void hugetlb_unregister_node(struct node *node) {}
 254 #endif
 255
 256 static void node_device_release(struct device *dev)
 257 {
 258         struct node *node = to_node(dev);
 259
 260 #if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HUGETLBFS)
 261         /*
 262          * We schedule the work only when a memory section is
 263          * onlined/offlined on this node. When we come here,
 264          * all the memory on this node has been offlined,
 265          * so we won't enqueue new work to this work.
 266          *
 267          * The work is using node->node_work, so we should
 268          * flush work before freeing the memory.
 269          */
 270         flush_work(&node->node_work);
 271 #endif
 272         kfree(node);
 273 }
 274
 275 /*
 276  * register_node - Setup a sysfs device for a node.
 277  * @num - Node number to use when creating the device.
 278  *
 279  * Initialize and register the node device.
 280  */
 281 static int register_node(struct node *node, int num, struct node *parent)
 282 {
 283         int error;
 284
 285         node->dev.id = num;
 286         node->dev.bus = &node_subsys;
 287         node->dev.release = node_device_release;
 288         error = device_register(&node->dev);
 289
 290         if (!error){
 291                 device_create_file(&node->dev, &dev_attr_cpumap);
 292                 device_create_file(&node->dev, &dev_attr_cpulist);
 293                 device_create_file(&node->dev, &dev_attr_meminfo);
 294                 device_create_file(&node->dev, &dev_attr_numastat);
 295                 device_create_file(&node->dev, &dev_attr_distance);
 296                 device_create_file(&node->dev, &dev_attr_vmstat);
 297
 298                 scan_unevictable_register_node(node);
 299
 300                 hugetlb_register_node(node);
 301
 302                 compaction_register_node(node);
 303         }
 304         return error;
 305 }
 306
 307 /**
 308  * unregister_node - unregister a node device
 309  * @node: node going away
 310  *
 311  * Unregisters a node device @node.  All the devices on the node must be
 312  * unregistered before calling this function.
 313  */
 314 void unregister_node(struct node *node)
 315 {
 316         device_remove_file(&node->dev, &dev_attr_cpumap);
 317         device_remove_file(&node->dev, &dev_attr_cpulist);
 318         device_remove_file(&node->dev, &dev_attr_meminfo);
 319         device_remove_file(&node->dev, &dev_attr_numastat);
 320         device_remove_file(&node->dev, &dev_attr_distance);
 321         device_remove_file(&node->dev, &dev_attr_vmstat);
 322
 323         scan_unevictable_unregister_node(node);
 324         hugetlb_unregister_node(node);          /* no-op, if memoryless node */
 325
 326         device_unregister(&node->dev);
 327 }
 328
 329 struct node *node_devices[MAX_NUMNODES];
 330
 331 /*
 332  * register cpu under node
 333  */
 334 int register_cpu_under_node(unsigned int cpu, unsigned int nid)
 335 {
 336         int ret;
 337         struct device *obj;
 338
 339         if (!node_online(nid))
 340                 return 0;
 341
 342         obj = get_cpu_device(cpu);
 343         if (!obj)
 344                 return 0;
 345
 346         ret = sysfs_create_link(&node_devices[nid]->dev.kobj,
 347                                 &obj->kobj,
 348                                 kobject_name(&obj->kobj));
 349         if (ret)
 350                 return ret;
 351
 352         return sysfs_create_link(&obj->kobj,
 353                                  &node_devices[nid]->dev.kobj,
 354                                  kobject_name(&node_devices[nid]->dev.kobj));
 355 }
 356
 357 int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
 358 {
 359         struct device *obj;
 360
 361         if (!node_online(nid))
 362                 return 0;
 363
 364         obj = get_cpu_device(cpu);
 365         if (!obj)
 366                 return 0;
 367
 368         sysfs_remove_link(&node_devices[nid]->dev.kobj,
 369                           kobject_name(&obj->kobj));
 370         sysfs_remove_link(&obj->kobj,
 371                           kobject_name(&node_devices[nid]->dev.kobj));
 372
 373         return 0;
 374 }
 375
 376 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
 377 #define page_initialized(page)  (page->lru.next)
 378
 379 static int get_nid_for_pfn(unsigned long pfn)
 380 {
 381         struct page *page;
 382
 383         if (!pfn_valid_within(pfn))
 384                 return -1;
 385         page = pfn_to_page(pfn);
 386         if (!page_initialized(page))
 387                 return -1;
 388         return pfn_to_nid(pfn);
 389 }
 390
 391 /* register memory section under specified node if it spans that node */
 392 int register_mem_sect_under_node(struct memory_block *mem_blk, int nid)
 393 {
 394         int ret;
 395         unsigned long pfn, sect_start_pfn, sect_end_pfn;
 396
 397         if (!mem_blk)
 398                 return -EFAULT;
 399         if (!node_online(nid))
 400                 return 0;
 401
 402         sect_start_pfn = section_nr_to_pfn(mem_blk->start_section_nr);
 403         sect_end_pfn = section_nr_to_pfn(mem_blk->end_section_nr);
 404         sect_end_pfn += PAGES_PER_SECTION - 1;
 405         for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
 406                 int page_nid;
 407
 408                 page_nid = get_nid_for_pfn(pfn);
 409                 if (page_nid < 0)
 410                         continue;
 411                 if (page_nid != nid)
 412                         continue;
 413                 ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj,
 414                                         &mem_blk->dev.kobj,
 415                                         kobject_name(&mem_blk->dev.kobj));
 416                 if (ret)
 417                         return ret;
 418
 419                 return sysfs_create_link_nowarn(&mem_blk->dev.kobj,
 420                                 &node_devices[nid]->dev.kobj,
 421                                 kobject_name(&node_devices[nid]->dev.kobj));
 422         }
 423         /* mem section does not span the specified node */
 424         return 0;
 425 }
 426
 427 /* unregister memory section under all nodes that it spans */
 428 int unregister_mem_sect_under_nodes(struct memory_block *mem_blk,
 429                                     unsigned long phys_index)
 430 {
 431         NODEMASK_ALLOC(nodemask_t, unlinked_nodes, GFP_KERNEL);
 432         unsigned long pfn, sect_start_pfn, sect_end_pfn;
 433
 434         if (!mem_blk) {
 435                 NODEMASK_FREE(unlinked_nodes);
 436                 return -EFAULT;
 437         }
 438         if (!unlinked_nodes)
 439                 return -ENOMEM;
 440         nodes_clear(*unlinked_nodes);
 441
 442         sect_start_pfn = section_nr_to_pfn(phys_index);
 443         sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
 444         for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
 445                 int nid;
 446
 447                 nid = get_nid_for_pfn(pfn);
 448                 if (nid < 0)
 449                         continue;
 450                 if (!node_online(nid))
 451                         continue;
 452                 if (node_test_and_set(nid, *unlinked_nodes))
 453                         continue;
 454                 sysfs_remove_link(&node_devices[nid]->dev.kobj,
 455                          kobject_name(&mem_blk->dev.kobj));
 456                 sysfs_remove_link(&mem_blk->dev.kobj,
 457                          kobject_name(&node_devices[nid]->dev.kobj));
 458         }
 459         NODEMASK_FREE(unlinked_nodes);
 460         return 0;
 461 }
 462
 463 static int link_mem_sections(int nid)
 464 {
 465         unsigned long start_pfn = NODE_DATA(nid)->node_start_pfn;
 466         unsigned long end_pfn = start_pfn + NODE_DATA(nid)->node_spanned_pages;
 467         unsigned long pfn;
 468         struct memory_block *mem_blk = NULL;
 469         int err = 0;
 470
 471         for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
 472                 unsigned long section_nr = pfn_to_section_nr(pfn);
 473                 struct mem_section *mem_sect;
 474                 int ret;
 475
 476                 if (!present_section_nr(section_nr))
 477                         continue;
 478                 mem_sect = __nr_to_section(section_nr);
 479
 480                 /* same memblock ? */
 481                 if (mem_blk)
 482                         if ((section_nr >= mem_blk->start_section_nr) &&
 483                             (section_nr <= mem_blk->end_section_nr))
 484                                 continue;
 485
 486                 mem_blk = find_memory_block_hinted(mem_sect, mem_blk);
 487
 488                 ret = register_mem_sect_under_node(mem_blk, nid);
 489                 if (!err)
 490                         err = ret;
 491
 492                 /* discard ref obtained in find_memory_block() */
 493         }
 494
 495         if (mem_blk)
 496                 kobject_put(&mem_blk->dev.kobj);
 497         return err;
 498 }
 499
 500 #ifdef CONFIG_HUGETLBFS
 501 /*
 502  * Handle per node hstate attribute [un]registration on transistions
 503  * to/from memoryless state.
 504  */
 505 static void node_hugetlb_work(struct work_struct *work)
 506 {
 507         struct node *node = container_of(work, struct node, node_work);
 508
 509         /*
 510          * We only get here when a node transitions to/from memoryless state.
 511          * We can detect which transition occurred by examining whether the
 512          * node has memory now.  hugetlb_register_node() already check this
 513          * so we try to register the attributes.  If that fails, then the
 514          * node has transitioned to memoryless, try to unregister the
 515          * attributes.
 516          */
 517         if (!hugetlb_register_node(node))
 518                 hugetlb_unregister_node(node);
 519 }
 520
 521 static void init_node_hugetlb_work(int nid)
 522 {
 523         INIT_WORK(&node_devices[nid]->node_work, node_hugetlb_work);
 524 }
 525
 526 static int node_memory_callback(struct notifier_block *self,
 527                                 unsigned long action, void *arg)
 528 {
 529         struct memory_notify *mnb = arg;
 530         int nid = mnb->status_change_nid;
 531
 532         switch (action) {
 533         case MEM_ONLINE:
 534         case MEM_OFFLINE:
 535                 /*
 536                  * offload per node hstate [un]registration to a work thread
 537                  * when transitioning to/from memoryless state.
 538                  */
 539                 if (nid != NUMA_NO_NODE)
 540                         schedule_work(&node_devices[nid]->node_work);
 541                 break;
 542
 543         case MEM_GOING_ONLINE:
 544         case MEM_GOING_OFFLINE:
 545         case MEM_CANCEL_ONLINE:
 546         case MEM_CANCEL_OFFLINE:
 547         default:
 548                 break;
 549         }
 550
 551         return NOTIFY_OK;
 552 }
 553 #endif  /* CONFIG_HUGETLBFS */
 554 #else   /* !CONFIG_MEMORY_HOTPLUG_SPARSE */
 555
 556 static int link_mem_sections(int nid) { return 0; }
 557 #endif  /* CONFIG_MEMORY_HOTPLUG_SPARSE */
 558
 559 #if !defined(CONFIG_MEMORY_HOTPLUG_SPARSE) || \
 560     !defined(CONFIG_HUGETLBFS)
 561 static inline int node_memory_callback(struct notifier_block *self,
 562                                 unsigned long action, void *arg)
 563 {
 564         return NOTIFY_OK;
 565 }
 566
 567 static void init_node_hugetlb_work(int nid) { }
 568
 569 #endif
 570
 571 int register_one_node(int nid)
 572 {
 573         int error = 0;
 574         int cpu;
 575
 576         if (node_online(nid)) {
 577                 int p_node = parent_node(nid);
 578                 struct node *parent = NULL;
 579
 580                 if (p_node != nid)
 581                         parent = node_devices[p_node];
 582
 583                 node_devices[nid] = kzalloc(sizeof(struct node), GFP_KERNEL);
 584                 if (!node_devices[nid])
 585                         return -ENOMEM;
 586
 587                 error = register_node(node_devices[nid], nid, parent);
 588
 589                 /* link cpu under this node */
 590                 for_each_present_cpu(cpu) {
 591                         if (cpu_to_node(cpu) == nid)
 592                                 register_cpu_under_node(cpu, nid);
 593                 }
 594
 595                 /* link memory sections under this node */
 596                 error = link_mem_sections(nid);
 597
 598                 /* initialize work queue for memory hot plug */
 599                 init_node_hugetlb_work(nid);
 600         }
 601
 602         return error;
 603
 604 }
 605
 606 void unregister_one_node(int nid)
 607 {
 608         unregister_node(node_devices[nid]);
 609         node_devices[nid] = NULL;
 610 }
 611
 612 /*
 613  * node states attributes
 614  */
 615
 616 static ssize_t print_nodes_state(enum node_states state, char *buf)
 617 {
 618         int n;
 619
 620         n = nodelist_scnprintf(buf, PAGE_SIZE-2, node_states[state]);
 621         buf[n++] = '\n';
 622         buf[n] = '\0';
 623         return n;
 624 }
 625
 626 struct node_attr {
 627         struct device_attribute attr;
 628         enum node_states state;
 629 };
 630
 631 static ssize_t show_node_state(struct device *dev,
 632                                struct device_attribute *attr, char *buf)
 633 {
 634         struct node_attr *na = container_of(attr, struct node_attr, attr);
 635         return print_nodes_state(na->state, buf);
 636 }
 637
 638 #define _NODE_ATTR(name, state) \
 639         { __ATTR(name, 0444, show_node_state, NULL), state }
 640
 641 static struct node_attr node_state_attr[] = {
 642         [N_POSSIBLE] = _NODE_ATTR(possible, N_POSSIBLE),
 643         [N_ONLINE] = _NODE_ATTR(online, N_ONLINE),
 644         [N_NORMAL_MEMORY] = _NODE_ATTR(has_normal_memory, N_NORMAL_MEMORY),
 645 #ifdef CONFIG_HIGHMEM
 646         [N_HIGH_MEMORY] = _NODE_ATTR(has_high_memory, N_HIGH_MEMORY),
 647 #endif
 648 #ifdef CONFIG_MOVABLE_NODE
 649         [N_MEMORY] = _NODE_ATTR(has_memory, N_MEMORY),
 650 #endif
 651         [N_CPU] = _NODE_ATTR(has_cpu, N_CPU),
 652 };
 653
 654 static struct attribute *node_state_attrs[] = {
 655         &node_state_attr[N_POSSIBLE].attr.attr,
 656         &node_state_attr[N_ONLINE].attr.attr,
 657         &node_state_attr[N_NORMAL_MEMORY].attr.attr,
 658 #ifdef CONFIG_HIGHMEM
 659         &node_state_attr[N_HIGH_MEMORY].attr.attr,
 660 #endif
 661 #ifdef CONFIG_MOVABLE_NODE
 662         &node_state_attr[N_MEMORY].attr.attr,
 663 #endif
 664         &node_state_attr[N_CPU].attr.attr,
 665         NULL
 666 };
 667
 668 static struct attribute_group memory_root_attr_group = {
 669         .attrs = node_state_attrs,
 670 };
 671
 672 static const struct attribute_group *cpu_root_attr_groups[] = {
 673         &memory_root_attr_group,
 674         NULL,
 675 };
 676
 677 #define NODE_CALLBACK_PRI       2       /* lower than SLAB */
 678 static int __init register_node_type(void)
 679 {
 680         int ret;
 681
 682         BUILD_BUG_ON(ARRAY_SIZE(node_state_attr) != NR_NODE_STATES);
 683         BUILD_BUG_ON(ARRAY_SIZE(node_state_attrs)-1 != NR_NODE_STATES);
 684
 685         ret = subsys_system_register(&node_subsys, cpu_root_attr_groups);
 686         if (!ret) {
 687                 static struct notifier_block node_memory_callback_nb = {
 688                         .notifier_call = node_memory_callback,
 689                         .priority = NODE_CALLBACK_PRI,
 690                 };
 691                 register_hotmemory_notifier(&node_memory_callback_nb);
 692         }
 693
 694         /*
 695          * Note:  we're not going to unregister the node class if we fail
 696          * to register the node state class attribute files.
 697          */
 698         return ret;
 699 }
 700 postcore_initcall(register_node_type);