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