drivers/base/node.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Basic Node interface support
   4  */
   5
   6 #include <linux/module.h>
   7 #include <linux/init.h>
   8 #include <linux/mm.h>
   9 #include <linux/memory.h>
  10 #include <linux/vmstat.h>
  11 #include <linux/notifier.h>
  12 #include <linux/node.h>
  13 #include <linux/hugetlb.h>
  14 #include <linux/compaction.h>
  15 #include <linux/cpumask.h>
  16 #include <linux/topology.h>
  17 #include <linux/nodemask.h>
  18 #include <linux/cpu.h>
  19 #include <linux/device.h>
  20 #include <linux/pm_runtime.h>
  21 #include <linux/swap.h>
  22 #include <linux/slab.h>
  23
  24 static struct bus_type node_subsys = {
  25         .name = "node",
  26         .dev_name = "node",
  27 };
  28
  29 static inline ssize_t cpumap_read(struct file *file, struct kobject *kobj,
  30                                   struct bin_attribute *attr, char *buf,
  31                                   loff_t off, size_t count)
  32 {
  33         struct device *dev = kobj_to_dev(kobj);
  34         struct node *node_dev = to_node(dev);
  35         cpumask_var_t mask;
  36         ssize_t n;
  37
  38         if (!alloc_cpumask_var(&mask, GFP_KERNEL))
  39                 return 0;
  40
  41         cpumask_and(mask, cpumask_of_node(node_dev->dev.id), cpu_online_mask);
  42         n = cpumap_print_bitmask_to_buf(buf, mask, off, count);
  43         free_cpumask_var(mask);
  44
  45         return n;
  46 }
  47
  48 static BIN_ATTR_RO(cpumap, CPUMAP_FILE_MAX_BYTES);
  49
  50 static inline ssize_t cpulist_read(struct file *file, struct kobject *kobj,
  51                                    struct bin_attribute *attr, char *buf,
  52                                    loff_t off, size_t count)
  53 {
  54         struct device *dev = kobj_to_dev(kobj);
  55         struct node *node_dev = to_node(dev);
  56         cpumask_var_t mask;
  57         ssize_t n;
  58
  59         if (!alloc_cpumask_var(&mask, GFP_KERNEL))
  60                 return 0;
  61
  62         cpumask_and(mask, cpumask_of_node(node_dev->dev.id), cpu_online_mask);
  63         n = cpumap_print_list_to_buf(buf, mask, off, count);
  64         free_cpumask_var(mask);
  65
  66         return n;
  67 }
  68
  69 static BIN_ATTR_RO(cpulist, CPULIST_FILE_MAX_BYTES);
  70
  71 /**
  72  * struct node_access_nodes - Access class device to hold user visible
  73  *                            relationships to other nodes.
  74  * @dev:        Device for this memory access class
  75  * @list_node:  List element in the node's access list
  76  * @access:     The access class rank
  77  * @hmem_attrs: Heterogeneous memory performance attributes
  78  */
  79 struct node_access_nodes {
  80         struct device           dev;
  81         struct list_head        list_node;
  82         unsigned int            access;
  83 #ifdef CONFIG_HMEM_REPORTING
  84         struct node_hmem_attrs  hmem_attrs;
  85 #endif
  86 };
  87 #define to_access_nodes(dev) container_of(dev, struct node_access_nodes, dev)
  88
  89 static struct attribute *node_init_access_node_attrs[] = {
  90         NULL,
  91 };
  92
  93 static struct attribute *node_targ_access_node_attrs[] = {
  94         NULL,
  95 };
  96
  97 static const struct attribute_group initiators = {
  98         .name   = "initiators",
  99         .attrs  = node_init_access_node_attrs,
 100 };
 101
 102 static const struct attribute_group targets = {
 103         .name   = "targets",
 104         .attrs  = node_targ_access_node_attrs,
 105 };
 106
 107 static const struct attribute_group *node_access_node_groups[] = {
 108         &initiators,
 109         &targets,
 110         NULL,
 111 };
 112
 113 static void node_remove_accesses(struct node *node)
 114 {
 115         struct node_access_nodes *c, *cnext;
 116
 117         list_for_each_entry_safe(c, cnext, &node->access_list, list_node) {
 118                 list_del(&c->list_node);
 119                 device_unregister(&c->dev);
 120         }
 121 }
 122
 123 static void node_access_release(struct device *dev)
 124 {
 125         kfree(to_access_nodes(dev));
 126 }
 127
 128 static struct node_access_nodes *node_init_node_access(struct node *node,
 129                                                        unsigned int access)
 130 {
 131         struct node_access_nodes *access_node;
 132         struct device *dev;
 133
 134         list_for_each_entry(access_node, &node->access_list, list_node)
 135                 if (access_node->access == access)
 136                         return access_node;
 137
 138         access_node = kzalloc(sizeof(*access_node), GFP_KERNEL);
 139         if (!access_node)
 140                 return NULL;
 141
 142         access_node->access = access;
 143         dev = &access_node->dev;
 144         dev->parent = &node->dev;
 145         dev->release = node_access_release;
 146         dev->groups = node_access_node_groups;
 147         if (dev_set_name(dev, "access%u", access))
 148                 goto free;
 149
 150         if (device_register(dev))
 151                 goto free_name;
 152
 153         pm_runtime_no_callbacks(dev);
 154         list_add_tail(&access_node->list_node, &node->access_list);
 155         return access_node;
 156 free_name:
 157         kfree_const(dev->kobj.name);
 158 free:
 159         kfree(access_node);
 160         return NULL;
 161 }
 162
 163 #ifdef CONFIG_HMEM_REPORTING
 164 #define ACCESS_ATTR(name)                                               \
 165 static ssize_t name##_show(struct device *dev,                          \
 166                            struct device_attribute *attr,               \
 167                            char *buf)                                   \
 168 {                                                                       \
 169         return sysfs_emit(buf, "%u\n",                                  \
 170                           to_access_nodes(dev)->hmem_attrs.name);       \
 171 }                                                                       \
 172 static DEVICE_ATTR_RO(name)
 173
 174 ACCESS_ATTR(read_bandwidth);
 175 ACCESS_ATTR(read_latency);
 176 ACCESS_ATTR(write_bandwidth);
 177 ACCESS_ATTR(write_latency);
 178
 179 static struct attribute *access_attrs[] = {
 180         &dev_attr_read_bandwidth.attr,
 181         &dev_attr_read_latency.attr,
 182         &dev_attr_write_bandwidth.attr,
 183         &dev_attr_write_latency.attr,
 184         NULL,
 185 };
 186
 187 /**
 188  * node_set_perf_attrs - Set the performance values for given access class
 189  * @nid: Node identifier to be set
 190  * @hmem_attrs: Heterogeneous memory performance attributes
 191  * @access: The access class the for the given attributes
 192  */
 193 void node_set_perf_attrs(unsigned int nid, struct node_hmem_attrs *hmem_attrs,
 194                          unsigned int access)
 195 {
 196         struct node_access_nodes *c;
 197         struct node *node;
 198         int i;
 199
 200         if (WARN_ON_ONCE(!node_online(nid)))
 201                 return;
 202
 203         node = node_devices[nid];
 204         c = node_init_node_access(node, access);
 205         if (!c)
 206                 return;
 207
 208         c->hmem_attrs = *hmem_attrs;
 209         for (i = 0; access_attrs[i] != NULL; i++) {
 210                 if (sysfs_add_file_to_group(&c->dev.kobj, access_attrs[i],
 211                                             "initiators")) {
 212                         pr_info("failed to add performance attribute to node %d\n",
 213                                 nid);
 214                         break;
 215                 }
 216         }
 217 }
 218
 219 /**
 220  * struct node_cache_info - Internal tracking for memory node caches
 221  * @dev:        Device represeting the cache level
 222  * @node:       List element for tracking in the node
 223  * @cache_attrs:Attributes for this cache level
 224  */
 225 struct node_cache_info {
 226         struct device dev;
 227         struct list_head node;
 228         struct node_cache_attrs cache_attrs;
 229 };
 230 #define to_cache_info(device) container_of(device, struct node_cache_info, dev)
 231
 232 #define CACHE_ATTR(name, fmt)                                           \
 233 static ssize_t name##_show(struct device *dev,                          \
 234                            struct device_attribute *attr,               \
 235                            char *buf)                                   \
 236 {                                                                       \
 237         return sysfs_emit(buf, fmt "\n",                                \
 238                           to_cache_info(dev)->cache_attrs.name);        \
 239 }                                                                       \
 240 static DEVICE_ATTR_RO(name);
 241
 242 CACHE_ATTR(size, "%llu")
 243 CACHE_ATTR(line_size, "%u")
 244 CACHE_ATTR(indexing, "%u")
 245 CACHE_ATTR(write_policy, "%u")
 246
 247 static struct attribute *cache_attrs[] = {
 248         &dev_attr_indexing.attr,
 249         &dev_attr_size.attr,
 250         &dev_attr_line_size.attr,
 251         &dev_attr_write_policy.attr,
 252         NULL,
 253 };
 254 ATTRIBUTE_GROUPS(cache);
 255
 256 static void node_cache_release(struct device *dev)
 257 {
 258         kfree(dev);
 259 }
 260
 261 static void node_cacheinfo_release(struct device *dev)
 262 {
 263         struct node_cache_info *info = to_cache_info(dev);
 264         kfree(info);
 265 }
 266
 267 static void node_init_cache_dev(struct node *node)
 268 {
 269         struct device *dev;
 270
 271         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 272         if (!dev)
 273                 return;
 274
 275         device_initialize(dev);
 276         dev->parent = &node->dev;
 277         dev->release = node_cache_release;
 278         if (dev_set_name(dev, "memory_side_cache"))
 279                 goto put_device;
 280
 281         if (device_add(dev))
 282                 goto put_device;
 283
 284         pm_runtime_no_callbacks(dev);
 285         node->cache_dev = dev;
 286         return;
 287 put_device:
 288         put_device(dev);
 289 }
 290
 291 /**
 292  * node_add_cache() - add cache attribute to a memory node
 293  * @nid: Node identifier that has new cache attributes
 294  * @cache_attrs: Attributes for the cache being added
 295  */
 296 void node_add_cache(unsigned int nid, struct node_cache_attrs *cache_attrs)
 297 {
 298         struct node_cache_info *info;
 299         struct device *dev;
 300         struct node *node;
 301
 302         if (!node_online(nid) || !node_devices[nid])
 303                 return;
 304
 305         node = node_devices[nid];
 306         list_for_each_entry(info, &node->cache_attrs, node) {
 307                 if (info->cache_attrs.level == cache_attrs->level) {
 308                         dev_warn(&node->dev,
 309                                 "attempt to add duplicate cache level:%d\n",
 310                                 cache_attrs->level);
 311                         return;
 312                 }
 313         }
 314
 315         if (!node->cache_dev)
 316                 node_init_cache_dev(node);
 317         if (!node->cache_dev)
 318                 return;
 319
 320         info = kzalloc(sizeof(*info), GFP_KERNEL);
 321         if (!info)
 322                 return;
 323
 324         dev = &info->dev;
 325         device_initialize(dev);
 326         dev->parent = node->cache_dev;
 327         dev->release = node_cacheinfo_release;
 328         dev->groups = cache_groups;
 329         if (dev_set_name(dev, "index%d", cache_attrs->level))
 330                 goto put_device;
 331
 332         info->cache_attrs = *cache_attrs;
 333         if (device_add(dev)) {
 334                 dev_warn(&node->dev, "failed to add cache level:%d\n",
 335                          cache_attrs->level);
 336                 goto put_device;
 337         }
 338         pm_runtime_no_callbacks(dev);
 339         list_add_tail(&info->node, &node->cache_attrs);
 340         return;
 341 put_device:
 342         put_device(dev);
 343 }
 344
 345 static void node_remove_caches(struct node *node)
 346 {
 347         struct node_cache_info *info, *next;
 348
 349         if (!node->cache_dev)
 350                 return;
 351
 352         list_for_each_entry_safe(info, next, &node->cache_attrs, node) {
 353                 list_del(&info->node);
 354                 device_unregister(&info->dev);
 355         }
 356         device_unregister(node->cache_dev);
 357 }
 358
 359 static void node_init_caches(unsigned int nid)
 360 {
 361         INIT_LIST_HEAD(&node_devices[nid]->cache_attrs);
 362 }
 363 #else
 364 static void node_init_caches(unsigned int nid) { }
 365 static void node_remove_caches(struct node *node) { }
 366 #endif
 367
 368 #define K(x) ((x) << (PAGE_SHIFT - 10))
 369 static ssize_t node_read_meminfo(struct device *dev,
 370                         struct device_attribute *attr, char *buf)
 371 {
 372         int len = 0;
 373         int nid = dev->id;
 374         struct pglist_data *pgdat = NODE_DATA(nid);
 375         struct sysinfo i;
 376         unsigned long sreclaimable, sunreclaimable;
 377         unsigned long swapcached = 0;
 378
 379         si_meminfo_node(&i, nid);
 380         sreclaimable = node_page_state_pages(pgdat, NR_SLAB_RECLAIMABLE_B);
 381         sunreclaimable = node_page_state_pages(pgdat, NR_SLAB_UNRECLAIMABLE_B);
 382 #ifdef CONFIG_SWAP
 383         swapcached = node_page_state_pages(pgdat, NR_SWAPCACHE);
 384 #endif
 385         len = sysfs_emit_at(buf, len,
 386                             "Node %d MemTotal:       %8lu kB\n"
 387                             "Node %d MemFree:        %8lu kB\n"
 388                             "Node %d MemUsed:        %8lu kB\n"
 389                             "Node %d SwapCached:     %8lu kB\n"
 390                             "Node %d Active:         %8lu kB\n"
 391                             "Node %d Inactive:       %8lu kB\n"
 392                             "Node %d Active(anon):   %8lu kB\n"
 393                             "Node %d Inactive(anon): %8lu kB\n"
 394                             "Node %d Active(file):   %8lu kB\n"
 395                             "Node %d Inactive(file): %8lu kB\n"
 396                             "Node %d Unevictable:    %8lu kB\n"
 397                             "Node %d Mlocked:        %8lu kB\n",
 398                             nid, K(i.totalram),
 399                             nid, K(i.freeram),
 400                             nid, K(i.totalram - i.freeram),
 401                             nid, K(swapcached),
 402                             nid, K(node_page_state(pgdat, NR_ACTIVE_ANON) +
 403                                    node_page_state(pgdat, NR_ACTIVE_FILE)),
 404                             nid, K(node_page_state(pgdat, NR_INACTIVE_ANON) +
 405                                    node_page_state(pgdat, NR_INACTIVE_FILE)),
 406                             nid, K(node_page_state(pgdat, NR_ACTIVE_ANON)),
 407                             nid, K(node_page_state(pgdat, NR_INACTIVE_ANON)),
 408                             nid, K(node_page_state(pgdat, NR_ACTIVE_FILE)),
 409                             nid, K(node_page_state(pgdat, NR_INACTIVE_FILE)),
 410                             nid, K(node_page_state(pgdat, NR_UNEVICTABLE)),
 411                             nid, K(sum_zone_node_page_state(nid, NR_MLOCK)));
 412
 413 #ifdef CONFIG_HIGHMEM
 414         len += sysfs_emit_at(buf, len,
 415                              "Node %d HighTotal:      %8lu kB\n"
 416                              "Node %d HighFree:       %8lu kB\n"
 417                              "Node %d LowTotal:       %8lu kB\n"
 418                              "Node %d LowFree:        %8lu kB\n",
 419                              nid, K(i.totalhigh),
 420                              nid, K(i.freehigh),
 421                              nid, K(i.totalram - i.totalhigh),
 422                              nid, K(i.freeram - i.freehigh));
 423 #endif
 424         len += sysfs_emit_at(buf, len,
 425                              "Node %d Dirty:          %8lu kB\n"
 426                              "Node %d Writeback:      %8lu kB\n"
 427                              "Node %d FilePages:      %8lu kB\n"
 428                              "Node %d Mapped:         %8lu kB\n"
 429                              "Node %d AnonPages:      %8lu kB\n"
 430                              "Node %d Shmem:          %8lu kB\n"
 431                              "Node %d KernelStack:    %8lu kB\n"
 432 #ifdef CONFIG_SHADOW_CALL_STACK
 433                              "Node %d ShadowCallStack:%8lu kB\n"
 434 #endif
 435                              "Node %d PageTables:     %8lu kB\n"
 436                              "Node %d SecPageTables:  %8lu kB\n"
 437                              "Node %d NFS_Unstable:   %8lu kB\n"
 438                              "Node %d Bounce:         %8lu kB\n"
 439                              "Node %d WritebackTmp:   %8lu kB\n"
 440                              "Node %d KReclaimable:   %8lu kB\n"
 441                              "Node %d Slab:           %8lu kB\n"
 442                              "Node %d SReclaimable:   %8lu kB\n"
 443                              "Node %d SUnreclaim:     %8lu kB\n"
 444 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 445                              "Node %d AnonHugePages:  %8lu kB\n"
 446                              "Node %d ShmemHugePages: %8lu kB\n"
 447                              "Node %d ShmemPmdMapped: %8lu kB\n"
 448                              "Node %d FileHugePages: %8lu kB\n"
 449                              "Node %d FilePmdMapped: %8lu kB\n"
 450 #endif
 451                              ,
 452                              nid, K(node_page_state(pgdat, NR_FILE_DIRTY)),
 453                              nid, K(node_page_state(pgdat, NR_WRITEBACK)),
 454                              nid, K(node_page_state(pgdat, NR_FILE_PAGES)),
 455                              nid, K(node_page_state(pgdat, NR_FILE_MAPPED)),
 456                              nid, K(node_page_state(pgdat, NR_ANON_MAPPED)),
 457                              nid, K(i.sharedram),
 458                              nid, node_page_state(pgdat, NR_KERNEL_STACK_KB),
 459 #ifdef CONFIG_SHADOW_CALL_STACK
 460                              nid, node_page_state(pgdat, NR_KERNEL_SCS_KB),
 461 #endif
 462                              nid, K(node_page_state(pgdat, NR_PAGETABLE)),
 463                              nid, K(node_page_state(pgdat, NR_SECONDARY_PAGETABLE)),
 464                              nid, 0UL,
 465                              nid, K(sum_zone_node_page_state(nid, NR_BOUNCE)),
 466                              nid, K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
 467                              nid, K(sreclaimable +
 468                                     node_page_state(pgdat, NR_KERNEL_MISC_RECLAIMABLE)),
 469                              nid, K(sreclaimable + sunreclaimable),
 470                              nid, K(sreclaimable),
 471                              nid, K(sunreclaimable)
 472 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 473                              ,
 474                              nid, K(node_page_state(pgdat, NR_ANON_THPS)),
 475                              nid, K(node_page_state(pgdat, NR_SHMEM_THPS)),
 476                              nid, K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED)),
 477                              nid, K(node_page_state(pgdat, NR_FILE_THPS)),
 478                              nid, K(node_page_state(pgdat, NR_FILE_PMDMAPPED))
 479 #endif
 480                             );
 481         len += hugetlb_report_node_meminfo(buf, len, nid);
 482         return len;
 483 }
 484
 485 #undef K
 486 static DEVICE_ATTR(meminfo, 0444, node_read_meminfo, NULL);
 487
 488 static ssize_t node_read_numastat(struct device *dev,
 489                                   struct device_attribute *attr, char *buf)
 490 {
 491         fold_vm_numa_events();
 492         return sysfs_emit(buf,
 493                           "numa_hit %lu\n"
 494                           "numa_miss %lu\n"
 495                           "numa_foreign %lu\n"
 496                           "interleave_hit %lu\n"
 497                           "local_node %lu\n"
 498                           "other_node %lu\n",
 499                           sum_zone_numa_event_state(dev->id, NUMA_HIT),
 500                           sum_zone_numa_event_state(dev->id, NUMA_MISS),
 501                           sum_zone_numa_event_state(dev->id, NUMA_FOREIGN),
 502                           sum_zone_numa_event_state(dev->id, NUMA_INTERLEAVE_HIT),
 503                           sum_zone_numa_event_state(dev->id, NUMA_LOCAL),
 504                           sum_zone_numa_event_state(dev->id, NUMA_OTHER));
 505 }
 506 static DEVICE_ATTR(numastat, 0444, node_read_numastat, NULL);
 507
 508 static ssize_t node_read_vmstat(struct device *dev,
 509                                 struct device_attribute *attr, char *buf)
 510 {
 511         int nid = dev->id;
 512         struct pglist_data *pgdat = NODE_DATA(nid);
 513         int i;
 514         int len = 0;
 515
 516         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
 517                 len += sysfs_emit_at(buf, len, "%s %lu\n",
 518                                      zone_stat_name(i),
 519                                      sum_zone_node_page_state(nid, i));
 520
 521 #ifdef CONFIG_NUMA
 522         fold_vm_numa_events();
 523         for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++)
 524                 len += sysfs_emit_at(buf, len, "%s %lu\n",
 525                                      numa_stat_name(i),
 526                                      sum_zone_numa_event_state(nid, i));
 527
 528 #endif
 529         for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
 530                 unsigned long pages = node_page_state_pages(pgdat, i);
 531
 532                 if (vmstat_item_print_in_thp(i))
 533                         pages /= HPAGE_PMD_NR;
 534                 len += sysfs_emit_at(buf, len, "%s %lu\n", node_stat_name(i),
 535                                      pages);
 536         }
 537
 538         return len;
 539 }
 540 static DEVICE_ATTR(vmstat, 0444, node_read_vmstat, NULL);
 541
 542 static ssize_t node_read_distance(struct device *dev,
 543                                   struct device_attribute *attr, char *buf)
 544 {
 545         int nid = dev->id;
 546         int len = 0;
 547         int i;
 548
 549         /*
 550          * buf is currently PAGE_SIZE in length and each node needs 4 chars
 551          * at the most (distance + space or newline).
 552          */
 553         BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE);
 554
 555         for_each_online_node(i) {
 556                 len += sysfs_emit_at(buf, len, "%s%d",
 557                                      i ? " " : "", node_distance(nid, i));
 558         }
 559
 560         len += sysfs_emit_at(buf, len, "\n");
 561         return len;
 562 }
 563 static DEVICE_ATTR(distance, 0444, node_read_distance, NULL);
 564
 565 static struct attribute *node_dev_attrs[] = {
 566         &dev_attr_meminfo.attr,
 567         &dev_attr_numastat.attr,
 568         &dev_attr_distance.attr,
 569         &dev_attr_vmstat.attr,
 570         NULL
 571 };
 572
 573 static struct bin_attribute *node_dev_bin_attrs[] = {
 574         &bin_attr_cpumap,
 575         &bin_attr_cpulist,
 576         NULL
 577 };
 578
 579 static const struct attribute_group node_dev_group = {
 580         .attrs = node_dev_attrs,
 581         .bin_attrs = node_dev_bin_attrs
 582 };
 583
 584 static const struct attribute_group *node_dev_groups[] = {
 585         &node_dev_group,
 586 #ifdef CONFIG_HAVE_ARCH_NODE_DEV_GROUP
 587         &arch_node_dev_group,
 588 #endif
 589         NULL
 590 };
 591
 592 #ifdef CONFIG_HUGETLBFS
 593 /*
 594  * hugetlbfs per node attributes registration interface:
 595  * When/if hugetlb[fs] subsystem initializes [sometime after this module],
 596  * it will register its per node attributes for all online nodes with
 597  * memory.  It will also call register_hugetlbfs_with_node(), below, to
 598  * register its attribute registration functions with this node driver.
 599  * Once these hooks have been initialized, the node driver will call into
 600  * the hugetlb module to [un]register attributes for hot-plugged nodes.
 601  */
 602 static node_registration_func_t __hugetlb_register_node;
 603 static node_registration_func_t __hugetlb_unregister_node;
 604
 605 static inline bool hugetlb_register_node(struct node *node)
 606 {
 607         if (__hugetlb_register_node &&
 608                         node_state(node->dev.id, N_MEMORY)) {
 609                 __hugetlb_register_node(node);
 610                 return true;
 611         }
 612         return false;
 613 }
 614
 615 static inline void hugetlb_unregister_node(struct node *node)
 616 {
 617         if (__hugetlb_unregister_node)
 618                 __hugetlb_unregister_node(node);
 619 }
 620
 621 void register_hugetlbfs_with_node(node_registration_func_t doregister,
 622                                   node_registration_func_t unregister)
 623 {
 624         __hugetlb_register_node   = doregister;
 625         __hugetlb_unregister_node = unregister;
 626 }
 627 #else
 628 static inline void hugetlb_register_node(struct node *node) {}
 629
 630 static inline void hugetlb_unregister_node(struct node *node) {}
 631 #endif
 632
 633 static void node_device_release(struct device *dev)
 634 {
 635         struct node *node = to_node(dev);
 636
 637 #if defined(CONFIG_MEMORY_HOTPLUG) && defined(CONFIG_HUGETLBFS)
 638         /*
 639          * We schedule the work only when a memory section is
 640          * onlined/offlined on this node. When we come here,
 641          * all the memory on this node has been offlined,
 642          * so we won't enqueue new work to this work.
 643          *
 644          * The work is using node->node_work, so we should
 645          * flush work before freeing the memory.
 646          */
 647         flush_work(&node->node_work);
 648 #endif
 649         kfree(node);
 650 }
 651
 652 /*
 653  * register_node - Setup a sysfs device for a node.
 654  * @num - Node number to use when creating the device.
 655  *
 656  * Initialize and register the node device.
 657  */
 658 static int register_node(struct node *node, int num)
 659 {
 660         int error;
 661
 662         node->dev.id = num;
 663         node->dev.bus = &node_subsys;
 664         node->dev.release = node_device_release;
 665         node->dev.groups = node_dev_groups;
 666         error = device_register(&node->dev);
 667
 668         if (error)
 669                 put_device(&node->dev);
 670         else {
 671                 hugetlb_register_node(node);
 672
 673                 compaction_register_node(node);
 674         }
 675         return error;
 676 }
 677
 678 /**
 679  * unregister_node - unregister a node device
 680  * @node: node going away
 681  *
 682  * Unregisters a node device @node.  All the devices on the node must be
 683  * unregistered before calling this function.
 684  */
 685 void unregister_node(struct node *node)
 686 {
 687         compaction_unregister_node(node);
 688         hugetlb_unregister_node(node);          /* no-op, if memoryless node */
 689         node_remove_accesses(node);
 690         node_remove_caches(node);
 691         device_unregister(&node->dev);
 692 }
 693
 694 struct node *node_devices[MAX_NUMNODES];
 695
 696 /*
 697  * register cpu under node
 698  */
 699 int register_cpu_under_node(unsigned int cpu, unsigned int nid)
 700 {
 701         int ret;
 702         struct device *obj;
 703
 704         if (!node_online(nid))
 705                 return 0;
 706
 707         obj = get_cpu_device(cpu);
 708         if (!obj)
 709                 return 0;
 710
 711         ret = sysfs_create_link(&node_devices[nid]->dev.kobj,
 712                                 &obj->kobj,
 713                                 kobject_name(&obj->kobj));
 714         if (ret)
 715                 return ret;
 716
 717         return sysfs_create_link(&obj->kobj,
 718                                  &node_devices[nid]->dev.kobj,
 719                                  kobject_name(&node_devices[nid]->dev.kobj));
 720 }
 721
 722 /**
 723  * register_memory_node_under_compute_node - link memory node to its compute
 724  *                                           node for a given access class.
 725  * @mem_nid:    Memory node number
 726  * @cpu_nid:    Cpu  node number
 727  * @access:     Access class to register
 728  *
 729  * Description:
 730  *      For use with platforms that may have separate memory and compute nodes.
 731  *      This function will export node relationships linking which memory
 732  *      initiator nodes can access memory targets at a given ranked access
 733  *      class.
 734  */
 735 int register_memory_node_under_compute_node(unsigned int mem_nid,
 736                                             unsigned int cpu_nid,
 737                                             unsigned int access)
 738 {
 739         struct node *init_node, *targ_node;
 740         struct node_access_nodes *initiator, *target;
 741         int ret;
 742
 743         if (!node_online(cpu_nid) || !node_online(mem_nid))
 744                 return -ENODEV;
 745
 746         init_node = node_devices[cpu_nid];
 747         targ_node = node_devices[mem_nid];
 748         initiator = node_init_node_access(init_node, access);
 749         target = node_init_node_access(targ_node, access);
 750         if (!initiator || !target)
 751                 return -ENOMEM;
 752
 753         ret = sysfs_add_link_to_group(&initiator->dev.kobj, "targets",
 754                                       &targ_node->dev.kobj,
 755                                       dev_name(&targ_node->dev));
 756         if (ret)
 757                 return ret;
 758
 759         ret = sysfs_add_link_to_group(&target->dev.kobj, "initiators",
 760                                       &init_node->dev.kobj,
 761                                       dev_name(&init_node->dev));
 762         if (ret)
 763                 goto err;
 764
 765         return 0;
 766  err:
 767         sysfs_remove_link_from_group(&initiator->dev.kobj, "targets",
 768                                      dev_name(&targ_node->dev));
 769         return ret;
 770 }
 771
 772 int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
 773 {
 774         struct device *obj;
 775
 776         if (!node_online(nid))
 777                 return 0;
 778
 779         obj = get_cpu_device(cpu);
 780         if (!obj)
 781                 return 0;
 782
 783         sysfs_remove_link(&node_devices[nid]->dev.kobj,
 784                           kobject_name(&obj->kobj));
 785         sysfs_remove_link(&obj->kobj,
 786                           kobject_name(&node_devices[nid]->dev.kobj));
 787
 788         return 0;
 789 }
 790
 791 #ifdef CONFIG_MEMORY_HOTPLUG
 792 static int __ref get_nid_for_pfn(unsigned long pfn)
 793 {
 794 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
 795         if (system_state < SYSTEM_RUNNING)
 796                 return early_pfn_to_nid(pfn);
 797 #endif
 798         return pfn_to_nid(pfn);
 799 }
 800
 801 static void do_register_memory_block_under_node(int nid,
 802                                                 struct memory_block *mem_blk,
 803                                                 enum meminit_context context)
 804 {
 805         int ret;
 806
 807         memory_block_add_nid(mem_blk, nid, context);
 808
 809         ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj,
 810                                        &mem_blk->dev.kobj,
 811                                        kobject_name(&mem_blk->dev.kobj));
 812         if (ret && ret != -EEXIST)
 813                 dev_err_ratelimited(&node_devices[nid]->dev,
 814                                     "can't create link to %s in sysfs (%d)\n",
 815                                     kobject_name(&mem_blk->dev.kobj), ret);
 816
 817         ret = sysfs_create_link_nowarn(&mem_blk->dev.kobj,
 818                                 &node_devices[nid]->dev.kobj,
 819                                 kobject_name(&node_devices[nid]->dev.kobj));
 820         if (ret && ret != -EEXIST)
 821                 dev_err_ratelimited(&mem_blk->dev,
 822                                     "can't create link to %s in sysfs (%d)\n",
 823                                     kobject_name(&node_devices[nid]->dev.kobj),
 824                                     ret);
 825 }
 826
 827 /* register memory section under specified node if it spans that node */
 828 static int register_mem_block_under_node_early(struct memory_block *mem_blk,
 829                                                void *arg)
 830 {
 831         unsigned long memory_block_pfns = memory_block_size_bytes() / PAGE_SIZE;
 832         unsigned long start_pfn = section_nr_to_pfn(mem_blk->start_section_nr);
 833         unsigned long end_pfn = start_pfn + memory_block_pfns - 1;
 834         int nid = *(int *)arg;
 835         unsigned long pfn;
 836
 837         for (pfn = start_pfn; pfn <= end_pfn; pfn++) {
 838                 int page_nid;
 839
 840                 /*
 841                  * memory block could have several absent sections from start.
 842                  * skip pfn range from absent section
 843                  */
 844                 if (!pfn_in_present_section(pfn)) {
 845                         pfn = round_down(pfn + PAGES_PER_SECTION,
 846                                          PAGES_PER_SECTION) - 1;
 847                         continue;
 848                 }
 849
 850                 /*
 851                  * We need to check if page belongs to nid only at the boot
 852                  * case because node's ranges can be interleaved.
 853                  */
 854                 page_nid = get_nid_for_pfn(pfn);
 855                 if (page_nid < 0)
 856                         continue;
 857                 if (page_nid != nid)
 858                         continue;
 859
 860                 do_register_memory_block_under_node(nid, mem_blk, MEMINIT_EARLY);
 861                 return 0;
 862         }
 863         /* mem section does not span the specified node */
 864         return 0;
 865 }
 866
 867 /*
 868  * During hotplug we know that all pages in the memory block belong to the same
 869  * node.
 870  */
 871 static int register_mem_block_under_node_hotplug(struct memory_block *mem_blk,
 872                                                  void *arg)
 873 {
 874         int nid = *(int *)arg;
 875
 876         do_register_memory_block_under_node(nid, mem_blk, MEMINIT_HOTPLUG);
 877         return 0;
 878 }
 879
 880 /*
 881  * Unregister a memory block device under the node it spans. Memory blocks
 882  * with multiple nodes cannot be offlined and therefore also never be removed.
 883  */
 884 void unregister_memory_block_under_nodes(struct memory_block *mem_blk)
 885 {
 886         if (mem_blk->nid == NUMA_NO_NODE)
 887                 return;
 888
 889         sysfs_remove_link(&node_devices[mem_blk->nid]->dev.kobj,
 890                           kobject_name(&mem_blk->dev.kobj));
 891         sysfs_remove_link(&mem_blk->dev.kobj,
 892                           kobject_name(&node_devices[mem_blk->nid]->dev.kobj));
 893 }
 894
 895 void register_memory_blocks_under_node(int nid, unsigned long start_pfn,
 896                                        unsigned long end_pfn,
 897                                        enum meminit_context context)
 898 {
 899         walk_memory_blocks_func_t func;
 900
 901         if (context == MEMINIT_HOTPLUG)
 902                 func = register_mem_block_under_node_hotplug;
 903         else
 904                 func = register_mem_block_under_node_early;
 905
 906         walk_memory_blocks(PFN_PHYS(start_pfn), PFN_PHYS(end_pfn - start_pfn),
 907                            (void *)&nid, func);
 908         return;
 909 }
 910
 911 #ifdef CONFIG_HUGETLBFS
 912 /*
 913  * Handle per node hstate attribute [un]registration on transistions
 914  * to/from memoryless state.
 915  */
 916 static void node_hugetlb_work(struct work_struct *work)
 917 {
 918         struct node *node = container_of(work, struct node, node_work);
 919
 920         /*
 921          * We only get here when a node transitions to/from memoryless state.
 922          * We can detect which transition occurred by examining whether the
 923          * node has memory now.  hugetlb_register_node() already check this
 924          * so we try to register the attributes.  If that fails, then the
 925          * node has transitioned to memoryless, try to unregister the
 926          * attributes.
 927          */
 928         if (!hugetlb_register_node(node))
 929                 hugetlb_unregister_node(node);
 930 }
 931
 932 static void init_node_hugetlb_work(int nid)
 933 {
 934         INIT_WORK(&node_devices[nid]->node_work, node_hugetlb_work);
 935 }
 936
 937 static int node_memory_callback(struct notifier_block *self,
 938                                 unsigned long action, void *arg)
 939 {
 940         struct memory_notify *mnb = arg;
 941         int nid = mnb->status_change_nid;
 942
 943         switch (action) {
 944         case MEM_ONLINE:
 945         case MEM_OFFLINE:
 946                 /*
 947                  * offload per node hstate [un]registration to a work thread
 948                  * when transitioning to/from memoryless state.
 949                  */
 950                 if (nid != NUMA_NO_NODE)
 951                         schedule_work(&node_devices[nid]->node_work);
 952                 break;
 953
 954         case MEM_GOING_ONLINE:
 955         case MEM_GOING_OFFLINE:
 956         case MEM_CANCEL_ONLINE:
 957         case MEM_CANCEL_OFFLINE:
 958         default:
 959                 break;
 960         }
 961
 962         return NOTIFY_OK;
 963 }
 964 #endif  /* CONFIG_HUGETLBFS */
 965 #endif /* CONFIG_MEMORY_HOTPLUG */
 966
 967 #if !defined(CONFIG_MEMORY_HOTPLUG) || !defined(CONFIG_HUGETLBFS)
 968 static inline int node_memory_callback(struct notifier_block *self,
 969                                 unsigned long action, void *arg)
 970 {
 971         return NOTIFY_OK;
 972 }
 973
 974 static void init_node_hugetlb_work(int nid) { }
 975
 976 #endif
 977
 978 int __register_one_node(int nid)
 979 {
 980         int error;
 981         int cpu;
 982
 983         node_devices[nid] = kzalloc(sizeof(struct node), GFP_KERNEL);
 984         if (!node_devices[nid])
 985                 return -ENOMEM;
 986
 987         error = register_node(node_devices[nid], nid);
 988
 989         /* link cpu under this node */
 990         for_each_present_cpu(cpu) {
 991                 if (cpu_to_node(cpu) == nid)
 992                         register_cpu_under_node(cpu, nid);
 993         }
 994
 995         INIT_LIST_HEAD(&node_devices[nid]->access_list);
 996         /* initialize work queue for memory hot plug */
 997         init_node_hugetlb_work(nid);
 998         node_init_caches(nid);
 999
1000         return error;
1001 }
1002
1003 void unregister_one_node(int nid)
1004 {
1005         if (!node_devices[nid])
1006                 return;
1007
1008         unregister_node(node_devices[nid]);
1009         node_devices[nid] = NULL;
1010 }
1011
1012 /*
1013  * node states attributes
1014  */
1015
1016 struct node_attr {
1017         struct device_attribute attr;
1018         enum node_states state;
1019 };
1020
1021 static ssize_t show_node_state(struct device *dev,
1022                                struct device_attribute *attr, char *buf)
1023 {
1024         struct node_attr *na = container_of(attr, struct node_attr, attr);
1025
1026         return sysfs_emit(buf, "%*pbl\n",
1027                           nodemask_pr_args(&node_states[na->state]));
1028 }
1029
1030 #define _NODE_ATTR(name, state) \
1031         { __ATTR(name, 0444, show_node_state, NULL), state }
1032
1033 static struct node_attr node_state_attr[] = {
1034         [N_POSSIBLE] = _NODE_ATTR(possible, N_POSSIBLE),
1035         [N_ONLINE] = _NODE_ATTR(online, N_ONLINE),
1036         [N_NORMAL_MEMORY] = _NODE_ATTR(has_normal_memory, N_NORMAL_MEMORY),
1037 #ifdef CONFIG_HIGHMEM
1038         [N_HIGH_MEMORY] = _NODE_ATTR(has_high_memory, N_HIGH_MEMORY),
1039 #endif
1040         [N_MEMORY] = _NODE_ATTR(has_memory, N_MEMORY),
1041         [N_CPU] = _NODE_ATTR(has_cpu, N_CPU),
1042         [N_GENERIC_INITIATOR] = _NODE_ATTR(has_generic_initiator,
1043                                            N_GENERIC_INITIATOR),
1044 };
1045
1046 static struct attribute *node_state_attrs[] = {
1047         &node_state_attr[N_POSSIBLE].attr.attr,
1048         &node_state_attr[N_ONLINE].attr.attr,
1049         &node_state_attr[N_NORMAL_MEMORY].attr.attr,
1050 #ifdef CONFIG_HIGHMEM
1051         &node_state_attr[N_HIGH_MEMORY].attr.attr,
1052 #endif
1053         &node_state_attr[N_MEMORY].attr.attr,
1054         &node_state_attr[N_CPU].attr.attr,
1055         &node_state_attr[N_GENERIC_INITIATOR].attr.attr,
1056         NULL
1057 };
1058
1059 static const struct attribute_group memory_root_attr_group = {
1060         .attrs = node_state_attrs,
1061 };
1062
1063 static const struct attribute_group *cpu_root_attr_groups[] = {
1064         &memory_root_attr_group,
1065         NULL,
1066 };
1067
1068 #define NODE_CALLBACK_PRI       2       /* lower than SLAB */
1069 void __init node_dev_init(void)
1070 {
1071         static struct notifier_block node_memory_callback_nb = {
1072                 .notifier_call = node_memory_callback,
1073                 .priority = NODE_CALLBACK_PRI,
1074         };
1075         int ret, i;
1076
1077         BUILD_BUG_ON(ARRAY_SIZE(node_state_attr) != NR_NODE_STATES);
1078         BUILD_BUG_ON(ARRAY_SIZE(node_state_attrs)-1 != NR_NODE_STATES);
1079
1080         ret = subsys_system_register(&node_subsys, cpu_root_attr_groups);
1081         if (ret)
1082                 panic("%s() failed to register subsystem: %d\n", __func__, ret);
1083
1084         register_hotmemory_notifier(&node_memory_callback_nb);
1085
1086         /*
1087          * Create all node devices, which will properly link the node
1088          * to applicable memory block devices and already created cpu devices.
1089          */
1090         for_each_online_node(i) {
1091                 ret = register_one_node(i);
1092                 if (ret)
1093                         panic("%s() failed to add node: %d\n", __func__, ret);
1094         }
1095 }