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 const 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  * @coord:      Heterogeneous memory performance coordinates
  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 access_coordinate        coord;
  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                                                        enum access_coordinate_class 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(property)                                           \
 165 static ssize_t property##_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)->coord.property);        \
 171 }                                                                       \
 172 static DEVICE_ATTR_RO(property)
 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  * @coord: Heterogeneous memory performance coordinates
 191  * @access: The access class the for the given attributes
 192  */
 193 void node_set_perf_attrs(unsigned int nid, struct access_coordinate *coord,
 194                          enum access_coordinate_class 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->coord = *coord;
 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 EXPORT_SYMBOL_GPL(node_set_perf_attrs);
 219
 220 /**
 221  * struct node_cache_info - Internal tracking for memory node caches
 222  * @dev:        Device represeting the cache level
 223  * @node:       List element for tracking in the node
 224  * @cache_attrs:Attributes for this cache level
 225  */
 226 struct node_cache_info {
 227         struct device dev;
 228         struct list_head node;
 229         struct node_cache_attrs cache_attrs;
 230 };
 231 #define to_cache_info(device) container_of(device, struct node_cache_info, dev)
 232
 233 #define CACHE_ATTR(name, fmt)                                           \
 234 static ssize_t name##_show(struct device *dev,                          \
 235                            struct device_attribute *attr,               \
 236                            char *buf)                                   \
 237 {                                                                       \
 238         return sysfs_emit(buf, fmt "\n",                                \
 239                           to_cache_info(dev)->cache_attrs.name);        \
 240 }                                                                       \
 241 static DEVICE_ATTR_RO(name);
 242
 243 CACHE_ATTR(size, "%llu")
 244 CACHE_ATTR(line_size, "%u")
 245 CACHE_ATTR(indexing, "%u")
 246 CACHE_ATTR(write_policy, "%u")
 247
 248 static struct attribute *cache_attrs[] = {
 249         &dev_attr_indexing.attr,
 250         &dev_attr_size.attr,
 251         &dev_attr_line_size.attr,
 252         &dev_attr_write_policy.attr,
 253         NULL,
 254 };
 255 ATTRIBUTE_GROUPS(cache);
 256
 257 static void node_cache_release(struct device *dev)
 258 {
 259         kfree(dev);
 260 }
 261
 262 static void node_cacheinfo_release(struct device *dev)
 263 {
 264         struct node_cache_info *info = to_cache_info(dev);
 265         kfree(info);
 266 }
 267
 268 static void node_init_cache_dev(struct node *node)
 269 {
 270         struct device *dev;
 271
 272         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 273         if (!dev)
 274                 return;
 275
 276         device_initialize(dev);
 277         dev->parent = &node->dev;
 278         dev->release = node_cache_release;
 279         if (dev_set_name(dev, "memory_side_cache"))
 280                 goto put_device;
 281
 282         if (device_add(dev))
 283                 goto put_device;
 284
 285         pm_runtime_no_callbacks(dev);
 286         node->cache_dev = dev;
 287         return;
 288 put_device:
 289         put_device(dev);
 290 }
 291
 292 /**
 293  * node_add_cache() - add cache attribute to a memory node
 294  * @nid: Node identifier that has new cache attributes
 295  * @cache_attrs: Attributes for the cache being added
 296  */
 297 void node_add_cache(unsigned int nid, struct node_cache_attrs *cache_attrs)
 298 {
 299         struct node_cache_info *info;
 300         struct device *dev;
 301         struct node *node;
 302
 303         if (!node_online(nid) || !node_devices[nid])
 304                 return;
 305
 306         node = node_devices[nid];
 307         list_for_each_entry(info, &node->cache_attrs, node) {
 308                 if (info->cache_attrs.level == cache_attrs->level) {
 309                         dev_warn(&node->dev,
 310                                 "attempt to add duplicate cache level:%d\n",
 311                                 cache_attrs->level);
 312                         return;
 313                 }
 314         }
 315
 316         if (!node->cache_dev)
 317                 node_init_cache_dev(node);
 318         if (!node->cache_dev)
 319                 return;
 320
 321         info = kzalloc(sizeof(*info), GFP_KERNEL);
 322         if (!info)
 323                 return;
 324
 325         dev = &info->dev;
 326         device_initialize(dev);
 327         dev->parent = node->cache_dev;
 328         dev->release = node_cacheinfo_release;
 329         dev->groups = cache_groups;
 330         if (dev_set_name(dev, "index%d", cache_attrs->level))
 331                 goto put_device;
 332
 333         info->cache_attrs = *cache_attrs;
 334         if (device_add(dev)) {
 335                 dev_warn(&node->dev, "failed to add cache level:%d\n",
 336                          cache_attrs->level);
 337                 goto put_device;
 338         }
 339         pm_runtime_no_callbacks(dev);
 340         list_add_tail(&info->node, &node->cache_attrs);
 341         return;
 342 put_device:
 343         put_device(dev);
 344 }
 345
 346 static void node_remove_caches(struct node *node)
 347 {
 348         struct node_cache_info *info, *next;
 349
 350         if (!node->cache_dev)
 351                 return;
 352
 353         list_for_each_entry_safe(info, next, &node->cache_attrs, node) {
 354                 list_del(&info->node);
 355                 device_unregister(&info->dev);
 356         }
 357         device_unregister(node->cache_dev);
 358 }
 359
 360 static void node_init_caches(unsigned int nid)
 361 {
 362         INIT_LIST_HEAD(&node_devices[nid]->cache_attrs);
 363 }
 364 #else
 365 static void node_init_caches(unsigned int nid) { }
 366 static void node_remove_caches(struct node *node) { }
 367 #endif
 368
 369 #define K(x) ((x) << (PAGE_SHIFT - 10))
 370 static ssize_t node_read_meminfo(struct device *dev,
 371                         struct device_attribute *attr, char *buf)
 372 {
 373         int len = 0;
 374         int nid = dev->id;
 375         struct pglist_data *pgdat = NODE_DATA(nid);
 376         struct sysinfo i;
 377         unsigned long sreclaimable, sunreclaimable;
 378         unsigned long swapcached = 0;
 379
 380         si_meminfo_node(&i, nid);
 381         sreclaimable = node_page_state_pages(pgdat, NR_SLAB_RECLAIMABLE_B);
 382         sunreclaimable = node_page_state_pages(pgdat, NR_SLAB_UNRECLAIMABLE_B);
 383 #ifdef CONFIG_SWAP
 384         swapcached = node_page_state_pages(pgdat, NR_SWAPCACHE);
 385 #endif
 386         len = sysfs_emit_at(buf, len,
 387                             "Node %d MemTotal:       %8lu kB\n"
 388                             "Node %d MemFree:        %8lu kB\n"
 389                             "Node %d MemUsed:        %8lu kB\n"
 390                             "Node %d SwapCached:     %8lu kB\n"
 391                             "Node %d Active:         %8lu kB\n"
 392                             "Node %d Inactive:       %8lu kB\n"
 393                             "Node %d Active(anon):   %8lu kB\n"
 394                             "Node %d Inactive(anon): %8lu kB\n"
 395                             "Node %d Active(file):   %8lu kB\n"
 396                             "Node %d Inactive(file): %8lu kB\n"
 397                             "Node %d Unevictable:    %8lu kB\n"
 398                             "Node %d Mlocked:        %8lu kB\n",
 399                             nid, K(i.totalram),
 400                             nid, K(i.freeram),
 401                             nid, K(i.totalram - i.freeram),
 402                             nid, K(swapcached),
 403                             nid, K(node_page_state(pgdat, NR_ACTIVE_ANON) +
 404                                    node_page_state(pgdat, NR_ACTIVE_FILE)),
 405                             nid, K(node_page_state(pgdat, NR_INACTIVE_ANON) +
 406                                    node_page_state(pgdat, NR_INACTIVE_FILE)),
 407                             nid, K(node_page_state(pgdat, NR_ACTIVE_ANON)),
 408                             nid, K(node_page_state(pgdat, NR_INACTIVE_ANON)),
 409                             nid, K(node_page_state(pgdat, NR_ACTIVE_FILE)),
 410                             nid, K(node_page_state(pgdat, NR_INACTIVE_FILE)),
 411                             nid, K(node_page_state(pgdat, NR_UNEVICTABLE)),
 412                             nid, K(sum_zone_node_page_state(nid, NR_MLOCK)));
 413
 414 #ifdef CONFIG_HIGHMEM
 415         len += sysfs_emit_at(buf, len,
 416                              "Node %d HighTotal:      %8lu kB\n"
 417                              "Node %d HighFree:       %8lu kB\n"
 418                              "Node %d LowTotal:       %8lu kB\n"
 419                              "Node %d LowFree:        %8lu kB\n",
 420                              nid, K(i.totalhigh),
 421                              nid, K(i.freehigh),
 422                              nid, K(i.totalram - i.totalhigh),
 423                              nid, K(i.freeram - i.freehigh));
 424 #endif
 425         len += sysfs_emit_at(buf, len,
 426                              "Node %d Dirty:          %8lu kB\n"
 427                              "Node %d Writeback:      %8lu kB\n"
 428                              "Node %d FilePages:      %8lu kB\n"
 429                              "Node %d Mapped:         %8lu kB\n"
 430                              "Node %d AnonPages:      %8lu kB\n"
 431                              "Node %d Shmem:          %8lu kB\n"
 432                              "Node %d KernelStack:    %8lu kB\n"
 433 #ifdef CONFIG_SHADOW_CALL_STACK
 434                              "Node %d ShadowCallStack:%8lu kB\n"
 435 #endif
 436                              "Node %d PageTables:     %8lu kB\n"
 437                              "Node %d SecPageTables:  %8lu kB\n"
 438                              "Node %d NFS_Unstable:   %8lu kB\n"
 439                              "Node %d Bounce:         %8lu kB\n"
 440                              "Node %d WritebackTmp:   %8lu kB\n"
 441                              "Node %d KReclaimable:   %8lu kB\n"
 442                              "Node %d Slab:           %8lu kB\n"
 443                              "Node %d SReclaimable:   %8lu kB\n"
 444                              "Node %d SUnreclaim:     %8lu kB\n"
 445 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 446                              "Node %d AnonHugePages:  %8lu kB\n"
 447                              "Node %d ShmemHugePages: %8lu kB\n"
 448                              "Node %d ShmemPmdMapped: %8lu kB\n"
 449                              "Node %d FileHugePages:  %8lu kB\n"
 450                              "Node %d FilePmdMapped:  %8lu kB\n"
 451 #endif
 452 #ifdef CONFIG_UNACCEPTED_MEMORY
 453                              "Node %d Unaccepted:     %8lu kB\n"
 454 #endif
 455                              ,
 456                              nid, K(node_page_state(pgdat, NR_FILE_DIRTY)),
 457                              nid, K(node_page_state(pgdat, NR_WRITEBACK)),
 458                              nid, K(node_page_state(pgdat, NR_FILE_PAGES)),
 459                              nid, K(node_page_state(pgdat, NR_FILE_MAPPED)),
 460                              nid, K(node_page_state(pgdat, NR_ANON_MAPPED)),
 461                              nid, K(i.sharedram),
 462                              nid, node_page_state(pgdat, NR_KERNEL_STACK_KB),
 463 #ifdef CONFIG_SHADOW_CALL_STACK
 464                              nid, node_page_state(pgdat, NR_KERNEL_SCS_KB),
 465 #endif
 466                              nid, K(node_page_state(pgdat, NR_PAGETABLE)),
 467                              nid, K(node_page_state(pgdat, NR_SECONDARY_PAGETABLE)),
 468                              nid, 0UL,
 469                              nid, K(sum_zone_node_page_state(nid, NR_BOUNCE)),
 470                              nid, K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
 471                              nid, K(sreclaimable +
 472                                     node_page_state(pgdat, NR_KERNEL_MISC_RECLAIMABLE)),
 473                              nid, K(sreclaimable + sunreclaimable),
 474                              nid, K(sreclaimable),
 475                              nid, K(sunreclaimable)
 476 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 477                              ,
 478                              nid, K(node_page_state(pgdat, NR_ANON_THPS)),
 479                              nid, K(node_page_state(pgdat, NR_SHMEM_THPS)),
 480                              nid, K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED)),
 481                              nid, K(node_page_state(pgdat, NR_FILE_THPS)),
 482                              nid, K(node_page_state(pgdat, NR_FILE_PMDMAPPED))
 483 #endif
 484 #ifdef CONFIG_UNACCEPTED_MEMORY
 485                              ,
 486                              nid, K(sum_zone_node_page_state(nid, NR_UNACCEPTED))
 487 #endif
 488                             );
 489         len += hugetlb_report_node_meminfo(buf, len, nid);
 490         return len;
 491 }
 492
 493 #undef K
 494 static DEVICE_ATTR(meminfo, 0444, node_read_meminfo, NULL);
 495
 496 static ssize_t node_read_numastat(struct device *dev,
 497                                   struct device_attribute *attr, char *buf)
 498 {
 499         fold_vm_numa_events();
 500         return sysfs_emit(buf,
 501                           "numa_hit %lu\n"
 502                           "numa_miss %lu\n"
 503                           "numa_foreign %lu\n"
 504                           "interleave_hit %lu\n"
 505                           "local_node %lu\n"
 506                           "other_node %lu\n",
 507                           sum_zone_numa_event_state(dev->id, NUMA_HIT),
 508                           sum_zone_numa_event_state(dev->id, NUMA_MISS),
 509                           sum_zone_numa_event_state(dev->id, NUMA_FOREIGN),
 510                           sum_zone_numa_event_state(dev->id, NUMA_INTERLEAVE_HIT),
 511                           sum_zone_numa_event_state(dev->id, NUMA_LOCAL),
 512                           sum_zone_numa_event_state(dev->id, NUMA_OTHER));
 513 }
 514 static DEVICE_ATTR(numastat, 0444, node_read_numastat, NULL);
 515
 516 static ssize_t node_read_vmstat(struct device *dev,
 517                                 struct device_attribute *attr, char *buf)
 518 {
 519         int nid = dev->id;
 520         struct pglist_data *pgdat = NODE_DATA(nid);
 521         int i;
 522         int len = 0;
 523
 524         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
 525                 len += sysfs_emit_at(buf, len, "%s %lu\n",
 526                                      zone_stat_name(i),
 527                                      sum_zone_node_page_state(nid, i));
 528
 529 #ifdef CONFIG_NUMA
 530         fold_vm_numa_events();
 531         for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++)
 532                 len += sysfs_emit_at(buf, len, "%s %lu\n",
 533                                      numa_stat_name(i),
 534                                      sum_zone_numa_event_state(nid, i));
 535
 536 #endif
 537         for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
 538                 unsigned long pages = node_page_state_pages(pgdat, i);
 539
 540                 if (vmstat_item_print_in_thp(i))
 541                         pages /= HPAGE_PMD_NR;
 542                 len += sysfs_emit_at(buf, len, "%s %lu\n", node_stat_name(i),
 543                                      pages);
 544         }
 545
 546         return len;
 547 }
 548 static DEVICE_ATTR(vmstat, 0444, node_read_vmstat, NULL);
 549
 550 static ssize_t node_read_distance(struct device *dev,
 551                                   struct device_attribute *attr, char *buf)
 552 {
 553         int nid = dev->id;
 554         int len = 0;
 555         int i;
 556
 557         /*
 558          * buf is currently PAGE_SIZE in length and each node needs 4 chars
 559          * at the most (distance + space or newline).
 560          */
 561         BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE);
 562
 563         for_each_online_node(i) {
 564                 len += sysfs_emit_at(buf, len, "%s%d",
 565                                      i ? " " : "", node_distance(nid, i));
 566         }
 567
 568         len += sysfs_emit_at(buf, len, "\n");
 569         return len;
 570 }
 571 static DEVICE_ATTR(distance, 0444, node_read_distance, NULL);
 572
 573 static struct attribute *node_dev_attrs[] = {
 574         &dev_attr_meminfo.attr,
 575         &dev_attr_numastat.attr,
 576         &dev_attr_distance.attr,
 577         &dev_attr_vmstat.attr,
 578         NULL
 579 };
 580
 581 static struct bin_attribute *node_dev_bin_attrs[] = {
 582         &bin_attr_cpumap,
 583         &bin_attr_cpulist,
 584         NULL
 585 };
 586
 587 static const struct attribute_group node_dev_group = {
 588         .attrs = node_dev_attrs,
 589         .bin_attrs = node_dev_bin_attrs
 590 };
 591
 592 static const struct attribute_group *node_dev_groups[] = {
 593         &node_dev_group,
 594 #ifdef CONFIG_HAVE_ARCH_NODE_DEV_GROUP
 595         &arch_node_dev_group,
 596 #endif
 597 #ifdef CONFIG_MEMORY_FAILURE
 598         &memory_failure_attr_group,
 599 #endif
 600         NULL
 601 };
 602
 603 static void node_device_release(struct device *dev)
 604 {
 605         kfree(to_node(dev));
 606 }
 607
 608 /*
 609  * register_node - Setup a sysfs device for a node.
 610  * @num - Node number to use when creating the device.
 611  *
 612  * Initialize and register the node device.
 613  */
 614 static int register_node(struct node *node, int num)
 615 {
 616         int error;
 617
 618         node->dev.id = num;
 619         node->dev.bus = &node_subsys;
 620         node->dev.release = node_device_release;
 621         node->dev.groups = node_dev_groups;
 622         error = device_register(&node->dev);
 623
 624         if (error) {
 625                 put_device(&node->dev);
 626         } else {
 627                 hugetlb_register_node(node);
 628                 compaction_register_node(node);
 629         }
 630
 631         return error;
 632 }
 633
 634 /**
 635  * unregister_node - unregister a node device
 636  * @node: node going away
 637  *
 638  * Unregisters a node device @node.  All the devices on the node must be
 639  * unregistered before calling this function.
 640  */
 641 void unregister_node(struct node *node)
 642 {
 643         hugetlb_unregister_node(node);
 644         compaction_unregister_node(node);
 645         node_remove_accesses(node);
 646         node_remove_caches(node);
 647         device_unregister(&node->dev);
 648 }
 649
 650 struct node *node_devices[MAX_NUMNODES];
 651
 652 /*
 653  * register cpu under node
 654  */
 655 int register_cpu_under_node(unsigned int cpu, unsigned int nid)
 656 {
 657         int ret;
 658         struct device *obj;
 659
 660         if (!node_online(nid))
 661                 return 0;
 662
 663         obj = get_cpu_device(cpu);
 664         if (!obj)
 665                 return 0;
 666
 667         ret = sysfs_create_link(&node_devices[nid]->dev.kobj,
 668                                 &obj->kobj,
 669                                 kobject_name(&obj->kobj));
 670         if (ret)
 671                 return ret;
 672
 673         return sysfs_create_link(&obj->kobj,
 674                                  &node_devices[nid]->dev.kobj,
 675                                  kobject_name(&node_devices[nid]->dev.kobj));
 676 }
 677
 678 /**
 679  * register_memory_node_under_compute_node - link memory node to its compute
 680  *                                           node for a given access class.
 681  * @mem_nid:    Memory node number
 682  * @cpu_nid:    Cpu  node number
 683  * @access:     Access class to register
 684  *
 685  * Description:
 686  *      For use with platforms that may have separate memory and compute nodes.
 687  *      This function will export node relationships linking which memory
 688  *      initiator nodes can access memory targets at a given ranked access
 689  *      class.
 690  */
 691 int register_memory_node_under_compute_node(unsigned int mem_nid,
 692                                             unsigned int cpu_nid,
 693                                             enum access_coordinate_class access)
 694 {
 695         struct node *init_node, *targ_node;
 696         struct node_access_nodes *initiator, *target;
 697         int ret;
 698
 699         if (!node_online(cpu_nid) || !node_online(mem_nid))
 700                 return -ENODEV;
 701
 702         init_node = node_devices[cpu_nid];
 703         targ_node = node_devices[mem_nid];
 704         initiator = node_init_node_access(init_node, access);
 705         target = node_init_node_access(targ_node, access);
 706         if (!initiator || !target)
 707                 return -ENOMEM;
 708
 709         ret = sysfs_add_link_to_group(&initiator->dev.kobj, "targets",
 710                                       &targ_node->dev.kobj,
 711                                       dev_name(&targ_node->dev));
 712         if (ret)
 713                 return ret;
 714
 715         ret = sysfs_add_link_to_group(&target->dev.kobj, "initiators",
 716                                       &init_node->dev.kobj,
 717                                       dev_name(&init_node->dev));
 718         if (ret)
 719                 goto err;
 720
 721         return 0;
 722  err:
 723         sysfs_remove_link_from_group(&initiator->dev.kobj, "targets",
 724                                      dev_name(&targ_node->dev));
 725         return ret;
 726 }
 727
 728 int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
 729 {
 730         struct device *obj;
 731
 732         if (!node_online(nid))
 733                 return 0;
 734
 735         obj = get_cpu_device(cpu);
 736         if (!obj)
 737                 return 0;
 738
 739         sysfs_remove_link(&node_devices[nid]->dev.kobj,
 740                           kobject_name(&obj->kobj));
 741         sysfs_remove_link(&obj->kobj,
 742                           kobject_name(&node_devices[nid]->dev.kobj));
 743
 744         return 0;
 745 }
 746
 747 #ifdef CONFIG_MEMORY_HOTPLUG
 748 static int __ref get_nid_for_pfn(unsigned long pfn)
 749 {
 750 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
 751         if (system_state < SYSTEM_RUNNING)
 752                 return early_pfn_to_nid(pfn);
 753 #endif
 754         return pfn_to_nid(pfn);
 755 }
 756
 757 static void do_register_memory_block_under_node(int nid,
 758                                                 struct memory_block *mem_blk,
 759                                                 enum meminit_context context)
 760 {
 761         int ret;
 762
 763         memory_block_add_nid(mem_blk, nid, context);
 764
 765         ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj,
 766                                        &mem_blk->dev.kobj,
 767                                        kobject_name(&mem_blk->dev.kobj));
 768         if (ret && ret != -EEXIST)
 769                 dev_err_ratelimited(&node_devices[nid]->dev,
 770                                     "can't create link to %s in sysfs (%d)\n",
 771                                     kobject_name(&mem_blk->dev.kobj), ret);
 772
 773         ret = sysfs_create_link_nowarn(&mem_blk->dev.kobj,
 774                                 &node_devices[nid]->dev.kobj,
 775                                 kobject_name(&node_devices[nid]->dev.kobj));
 776         if (ret && ret != -EEXIST)
 777                 dev_err_ratelimited(&mem_blk->dev,
 778                                     "can't create link to %s in sysfs (%d)\n",
 779                                     kobject_name(&node_devices[nid]->dev.kobj),
 780                                     ret);
 781 }
 782
 783 /* register memory section under specified node if it spans that node */
 784 static int register_mem_block_under_node_early(struct memory_block *mem_blk,
 785                                                void *arg)
 786 {
 787         unsigned long memory_block_pfns = memory_block_size_bytes() / PAGE_SIZE;
 788         unsigned long start_pfn = section_nr_to_pfn(mem_blk->start_section_nr);
 789         unsigned long end_pfn = start_pfn + memory_block_pfns - 1;
 790         int nid = *(int *)arg;
 791         unsigned long pfn;
 792
 793         for (pfn = start_pfn; pfn <= end_pfn; pfn++) {
 794                 int page_nid;
 795
 796                 /*
 797                  * memory block could have several absent sections from start.
 798                  * skip pfn range from absent section
 799                  */
 800                 if (!pfn_in_present_section(pfn)) {
 801                         pfn = round_down(pfn + PAGES_PER_SECTION,
 802                                          PAGES_PER_SECTION) - 1;
 803                         continue;
 804                 }
 805
 806                 /*
 807                  * We need to check if page belongs to nid only at the boot
 808                  * case because node's ranges can be interleaved.
 809                  */
 810                 page_nid = get_nid_for_pfn(pfn);
 811                 if (page_nid < 0)
 812                         continue;
 813                 if (page_nid != nid)
 814                         continue;
 815
 816                 do_register_memory_block_under_node(nid, mem_blk, MEMINIT_EARLY);
 817                 return 0;
 818         }
 819         /* mem section does not span the specified node */
 820         return 0;
 821 }
 822
 823 /*
 824  * During hotplug we know that all pages in the memory block belong to the same
 825  * node.
 826  */
 827 static int register_mem_block_under_node_hotplug(struct memory_block *mem_blk,
 828                                                  void *arg)
 829 {
 830         int nid = *(int *)arg;
 831
 832         do_register_memory_block_under_node(nid, mem_blk, MEMINIT_HOTPLUG);
 833         return 0;
 834 }
 835
 836 /*
 837  * Unregister a memory block device under the node it spans. Memory blocks
 838  * with multiple nodes cannot be offlined and therefore also never be removed.
 839  */
 840 void unregister_memory_block_under_nodes(struct memory_block *mem_blk)
 841 {
 842         if (mem_blk->nid == NUMA_NO_NODE)
 843                 return;
 844
 845         sysfs_remove_link(&node_devices[mem_blk->nid]->dev.kobj,
 846                           kobject_name(&mem_blk->dev.kobj));
 847         sysfs_remove_link(&mem_blk->dev.kobj,
 848                           kobject_name(&node_devices[mem_blk->nid]->dev.kobj));
 849 }
 850
 851 void register_memory_blocks_under_node(int nid, unsigned long start_pfn,
 852                                        unsigned long end_pfn,
 853                                        enum meminit_context context)
 854 {
 855         walk_memory_blocks_func_t func;
 856
 857         if (context == MEMINIT_HOTPLUG)
 858                 func = register_mem_block_under_node_hotplug;
 859         else
 860                 func = register_mem_block_under_node_early;
 861
 862         walk_memory_blocks(PFN_PHYS(start_pfn), PFN_PHYS(end_pfn - start_pfn),
 863                            (void *)&nid, func);
 864         return;
 865 }
 866 #endif /* CONFIG_MEMORY_HOTPLUG */
 867
 868 int __register_one_node(int nid)
 869 {
 870         int error;
 871         int cpu;
 872         struct node *node;
 873
 874         node = kzalloc(sizeof(struct node), GFP_KERNEL);
 875         if (!node)
 876                 return -ENOMEM;
 877
 878         INIT_LIST_HEAD(&node->access_list);
 879         node_devices[nid] = node;
 880
 881         error = register_node(node_devices[nid], nid);
 882
 883         /* link cpu under this node */
 884         for_each_present_cpu(cpu) {
 885                 if (cpu_to_node(cpu) == nid)
 886                         register_cpu_under_node(cpu, nid);
 887         }
 888
 889         node_init_caches(nid);
 890
 891         return error;
 892 }
 893
 894 void unregister_one_node(int nid)
 895 {
 896         if (!node_devices[nid])
 897                 return;
 898
 899         unregister_node(node_devices[nid]);
 900         node_devices[nid] = NULL;
 901 }
 902
 903 /*
 904  * node states attributes
 905  */
 906
 907 struct node_attr {
 908         struct device_attribute attr;
 909         enum node_states state;
 910 };
 911
 912 static ssize_t show_node_state(struct device *dev,
 913                                struct device_attribute *attr, char *buf)
 914 {
 915         struct node_attr *na = container_of(attr, struct node_attr, attr);
 916
 917         return sysfs_emit(buf, "%*pbl\n",
 918                           nodemask_pr_args(&node_states[na->state]));
 919 }
 920
 921 #define _NODE_ATTR(name, state) \
 922         { __ATTR(name, 0444, show_node_state, NULL), state }
 923
 924 static struct node_attr node_state_attr[] = {
 925         [N_POSSIBLE] = _NODE_ATTR(possible, N_POSSIBLE),
 926         [N_ONLINE] = _NODE_ATTR(online, N_ONLINE),
 927         [N_NORMAL_MEMORY] = _NODE_ATTR(has_normal_memory, N_NORMAL_MEMORY),
 928 #ifdef CONFIG_HIGHMEM
 929         [N_HIGH_MEMORY] = _NODE_ATTR(has_high_memory, N_HIGH_MEMORY),
 930 #endif
 931         [N_MEMORY] = _NODE_ATTR(has_memory, N_MEMORY),
 932         [N_CPU] = _NODE_ATTR(has_cpu, N_CPU),
 933         [N_GENERIC_INITIATOR] = _NODE_ATTR(has_generic_initiator,
 934                                            N_GENERIC_INITIATOR),
 935 };
 936
 937 static struct attribute *node_state_attrs[] = {
 938         &node_state_attr[N_POSSIBLE].attr.attr,
 939         &node_state_attr[N_ONLINE].attr.attr,
 940         &node_state_attr[N_NORMAL_MEMORY].attr.attr,
 941 #ifdef CONFIG_HIGHMEM
 942         &node_state_attr[N_HIGH_MEMORY].attr.attr,
 943 #endif
 944         &node_state_attr[N_MEMORY].attr.attr,
 945         &node_state_attr[N_CPU].attr.attr,
 946         &node_state_attr[N_GENERIC_INITIATOR].attr.attr,
 947         NULL
 948 };
 949
 950 static const struct attribute_group memory_root_attr_group = {
 951         .attrs = node_state_attrs,
 952 };
 953
 954 static const struct attribute_group *cpu_root_attr_groups[] = {
 955         &memory_root_attr_group,
 956         NULL,
 957 };
 958
 959 void __init node_dev_init(void)
 960 {
 961         int ret, i;
 962
 963         BUILD_BUG_ON(ARRAY_SIZE(node_state_attr) != NR_NODE_STATES);
 964         BUILD_BUG_ON(ARRAY_SIZE(node_state_attrs)-1 != NR_NODE_STATES);
 965
 966         ret = subsys_system_register(&node_subsys, cpu_root_attr_groups);
 967         if (ret)
 968                 panic("%s() failed to register subsystem: %d\n", __func__, ret);
 969
 970         /*
 971          * Create all node devices, which will properly link the node
 972          * to applicable memory block devices and already created cpu devices.
 973          */
 974         for_each_online_node(i) {
 975                 ret = register_one_node(i);
 976                 if (ret)
 977                         panic("%s() failed to add node: %d\n", __func__, ret);
 978         }
 979 }