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
  30 static ssize_t node_read_cpumap(struct device *dev, bool list, char *buf)
  31 {
  32         ssize_t n;
  33         cpumask_var_t mask;
  34         struct node *node_dev = to_node(dev);
  35
  36         /* 2008/04/07: buf currently PAGE_SIZE, need 9 chars per 32 bits. */
  37         BUILD_BUG_ON((NR_CPUS/32 * 9) > (PAGE_SIZE-1));
  38
  39         if (!alloc_cpumask_var(&mask, GFP_KERNEL))
  40                 return 0;
  41
  42         cpumask_and(mask, cpumask_of_node(node_dev->dev.id), cpu_online_mask);
  43         n = cpumap_print_to_pagebuf(list, buf, mask);
  44         free_cpumask_var(mask);
  45
  46         return n;
  47 }
  48
  49 static inline ssize_t node_read_cpumask(struct device *dev,
  50                                 struct device_attribute *attr, char *buf)
  51 {
  52         return node_read_cpumap(dev, false, buf);
  53 }
  54 static inline ssize_t node_read_cpulist(struct device *dev,
  55                                 struct device_attribute *attr, char *buf)
  56 {
  57         return node_read_cpumap(dev, true, buf);
  58 }
  59
  60 static DEVICE_ATTR(cpumap,  S_IRUGO, node_read_cpumask, NULL);
  61 static DEVICE_ATTR(cpulist, S_IRUGO, node_read_cpulist, NULL);
  62
  63 /**
  64  * struct node_access_nodes - Access class device to hold user visible
  65  *                            relationships to other nodes.
  66  * @dev:        Device for this memory access class
  67  * @list_node:  List element in the node's access list
  68  * @access:     The access class rank
  69  */
  70 struct node_access_nodes {
  71         struct device           dev;
  72         struct list_head        list_node;
  73         unsigned                access;
  74 #ifdef CONFIG_HMEM_REPORTING
  75         struct node_hmem_attrs  hmem_attrs;
  76 #endif
  77 };
  78 #define to_access_nodes(dev) container_of(dev, struct node_access_nodes, dev)
  79
  80 static struct attribute *node_init_access_node_attrs[] = {
  81         NULL,
  82 };
  83
  84 static struct attribute *node_targ_access_node_attrs[] = {
  85         NULL,
  86 };
  87
  88 static const struct attribute_group initiators = {
  89         .name   = "initiators",
  90         .attrs  = node_init_access_node_attrs,
  91 };
  92
  93 static const struct attribute_group targets = {
  94         .name   = "targets",
  95         .attrs  = node_targ_access_node_attrs,
  96 };
  97
  98 static const struct attribute_group *node_access_node_groups[] = {
  99         &initiators,
 100         &targets,
 101         NULL,
 102 };
 103
 104 static void node_remove_accesses(struct node *node)
 105 {
 106         struct node_access_nodes *c, *cnext;
 107
 108         list_for_each_entry_safe(c, cnext, &node->access_list, list_node) {
 109                 list_del(&c->list_node);
 110                 device_unregister(&c->dev);
 111         }
 112 }
 113
 114 static void node_access_release(struct device *dev)
 115 {
 116         kfree(to_access_nodes(dev));
 117 }
 118
 119 static struct node_access_nodes *node_init_node_access(struct node *node,
 120                                                        unsigned access)
 121 {
 122         struct node_access_nodes *access_node;
 123         struct device *dev;
 124
 125         list_for_each_entry(access_node, &node->access_list, list_node)
 126                 if (access_node->access == access)
 127                         return access_node;
 128
 129         access_node = kzalloc(sizeof(*access_node), GFP_KERNEL);
 130         if (!access_node)
 131                 return NULL;
 132
 133         access_node->access = access;
 134         dev = &access_node->dev;
 135         dev->parent = &node->dev;
 136         dev->release = node_access_release;
 137         dev->groups = node_access_node_groups;
 138         if (dev_set_name(dev, "access%u", access))
 139                 goto free;
 140
 141         if (device_register(dev))
 142                 goto free_name;
 143
 144         pm_runtime_no_callbacks(dev);
 145         list_add_tail(&access_node->list_node, &node->access_list);
 146         return access_node;
 147 free_name:
 148         kfree_const(dev->kobj.name);
 149 free:
 150         kfree(access_node);
 151         return NULL;
 152 }
 153
 154 #ifdef CONFIG_HMEM_REPORTING
 155 #define ACCESS_ATTR(name)                                                  \
 156 static ssize_t name##_show(struct device *dev,                             \
 157                            struct device_attribute *attr,                  \
 158                            char *buf)                                      \
 159 {                                                                          \
 160         return sprintf(buf, "%u\n", to_access_nodes(dev)->hmem_attrs.name); \
 161 }                                                                          \
 162 static DEVICE_ATTR_RO(name);
 163
 164 ACCESS_ATTR(read_bandwidth)
 165 ACCESS_ATTR(read_latency)
 166 ACCESS_ATTR(write_bandwidth)
 167 ACCESS_ATTR(write_latency)
 168
 169 static struct attribute *access_attrs[] = {
 170         &dev_attr_read_bandwidth.attr,
 171         &dev_attr_read_latency.attr,
 172         &dev_attr_write_bandwidth.attr,
 173         &dev_attr_write_latency.attr,
 174         NULL,
 175 };
 176
 177 /**
 178  * node_set_perf_attrs - Set the performance values for given access class
 179  * @nid: Node identifier to be set
 180  * @hmem_attrs: Heterogeneous memory performance attributes
 181  * @access: The access class the for the given attributes
 182  */
 183 void node_set_perf_attrs(unsigned int nid, struct node_hmem_attrs *hmem_attrs,
 184                          unsigned access)
 185 {
 186         struct node_access_nodes *c;
 187         struct node *node;
 188         int i;
 189
 190         if (WARN_ON_ONCE(!node_online(nid)))
 191                 return;
 192
 193         node = node_devices[nid];
 194         c = node_init_node_access(node, access);
 195         if (!c)
 196                 return;
 197
 198         c->hmem_attrs = *hmem_attrs;
 199         for (i = 0; access_attrs[i] != NULL; i++) {
 200                 if (sysfs_add_file_to_group(&c->dev.kobj, access_attrs[i],
 201                                             "initiators")) {
 202                         pr_info("failed to add performance attribute to node %d\n",
 203                                 nid);
 204                         break;
 205                 }
 206         }
 207 }
 208
 209 /**
 210  * struct node_cache_info - Internal tracking for memory node caches
 211  * @dev:        Device represeting the cache level
 212  * @node:       List element for tracking in the node
 213  * @cache_attrs:Attributes for this cache level
 214  */
 215 struct node_cache_info {
 216         struct device dev;
 217         struct list_head node;
 218         struct node_cache_attrs cache_attrs;
 219 };
 220 #define to_cache_info(device) container_of(device, struct node_cache_info, dev)
 221
 222 #define CACHE_ATTR(name, fmt)                                           \
 223 static ssize_t name##_show(struct device *dev,                          \
 224                            struct device_attribute *attr,               \
 225                            char *buf)                                   \
 226 {                                                                       \
 227         return sprintf(buf, fmt "\n", to_cache_info(dev)->cache_attrs.name);\
 228 }                                                                       \
 229 DEVICE_ATTR_RO(name);
 230
 231 CACHE_ATTR(size, "%llu")
 232 CACHE_ATTR(line_size, "%u")
 233 CACHE_ATTR(indexing, "%u")
 234 CACHE_ATTR(write_policy, "%u")
 235
 236 static struct attribute *cache_attrs[] = {
 237         &dev_attr_indexing.attr,
 238         &dev_attr_size.attr,
 239         &dev_attr_line_size.attr,
 240         &dev_attr_write_policy.attr,
 241         NULL,
 242 };
 243 ATTRIBUTE_GROUPS(cache);
 244
 245 static void node_cache_release(struct device *dev)
 246 {
 247         kfree(dev);
 248 }
 249
 250 static void node_cacheinfo_release(struct device *dev)
 251 {
 252         struct node_cache_info *info = to_cache_info(dev);
 253         kfree(info);
 254 }
 255
 256 static void node_init_cache_dev(struct node *node)
 257 {
 258         struct device *dev;
 259
 260         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 261         if (!dev)
 262                 return;
 263
 264         dev->parent = &node->dev;
 265         dev->release = node_cache_release;
 266         if (dev_set_name(dev, "memory_side_cache"))
 267                 goto free_dev;
 268
 269         if (device_register(dev))
 270                 goto free_name;
 271
 272         pm_runtime_no_callbacks(dev);
 273         node->cache_dev = dev;
 274         return;
 275 free_name:
 276         kfree_const(dev->kobj.name);
 277 free_dev:
 278         kfree(dev);
 279 }
 280
 281 /**
 282  * node_add_cache() - add cache attribute to a memory node
 283  * @nid: Node identifier that has new cache attributes
 284  * @cache_attrs: Attributes for the cache being added
 285  */
 286 void node_add_cache(unsigned int nid, struct node_cache_attrs *cache_attrs)
 287 {
 288         struct node_cache_info *info;
 289         struct device *dev;
 290         struct node *node;
 291
 292         if (!node_online(nid) || !node_devices[nid])
 293                 return;
 294
 295         node = node_devices[nid];
 296         list_for_each_entry(info, &node->cache_attrs, node) {
 297                 if (info->cache_attrs.level == cache_attrs->level) {
 298                         dev_warn(&node->dev,
 299                                 "attempt to add duplicate cache level:%d\n",
 300                                 cache_attrs->level);
 301                         return;
 302                 }
 303         }
 304
 305         if (!node->cache_dev)
 306                 node_init_cache_dev(node);
 307         if (!node->cache_dev)
 308                 return;
 309
 310         info = kzalloc(sizeof(*info), GFP_KERNEL);
 311         if (!info)
 312                 return;
 313
 314         dev = &info->dev;
 315         dev->parent = node->cache_dev;
 316         dev->release = node_cacheinfo_release;
 317         dev->groups = cache_groups;
 318         if (dev_set_name(dev, "index%d", cache_attrs->level))
 319                 goto free_cache;
 320
 321         info->cache_attrs = *cache_attrs;
 322         if (device_register(dev)) {
 323                 dev_warn(&node->dev, "failed to add cache level:%d\n",
 324                          cache_attrs->level);
 325                 goto free_name;
 326         }
 327         pm_runtime_no_callbacks(dev);
 328         list_add_tail(&info->node, &node->cache_attrs);
 329         return;
 330 free_name:
 331         kfree_const(dev->kobj.name);
 332 free_cache:
 333         kfree(info);
 334 }
 335
 336 static void node_remove_caches(struct node *node)
 337 {
 338         struct node_cache_info *info, *next;
 339
 340         if (!node->cache_dev)
 341                 return;
 342
 343         list_for_each_entry_safe(info, next, &node->cache_attrs, node) {
 344                 list_del(&info->node);
 345                 device_unregister(&info->dev);
 346         }
 347         device_unregister(node->cache_dev);
 348 }
 349
 350 static void node_init_caches(unsigned int nid)
 351 {
 352         INIT_LIST_HEAD(&node_devices[nid]->cache_attrs);
 353 }
 354 #else
 355 static void node_init_caches(unsigned int nid) { }
 356 static void node_remove_caches(struct node *node) { }
 357 #endif
 358
 359 #define K(x) ((x) << (PAGE_SHIFT - 10))
 360 static ssize_t node_read_meminfo(struct device *dev,
 361                         struct device_attribute *attr, char *buf)
 362 {
 363         int n;
 364         int nid = dev->id;
 365         struct pglist_data *pgdat = NODE_DATA(nid);
 366         struct sysinfo i;
 367         unsigned long sreclaimable, sunreclaimable;
 368
 369         si_meminfo_node(&i, nid);
 370         sreclaimable = node_page_state(pgdat, NR_SLAB_RECLAIMABLE);
 371         sunreclaimable = node_page_state(pgdat, NR_SLAB_UNRECLAIMABLE);
 372         n = sprintf(buf,
 373                        "Node %d MemTotal:       %8lu kB\n"
 374                        "Node %d MemFree:        %8lu kB\n"
 375                        "Node %d MemUsed:        %8lu kB\n"
 376                        "Node %d Active:         %8lu kB\n"
 377                        "Node %d Inactive:       %8lu kB\n"
 378                        "Node %d Active(anon):   %8lu kB\n"
 379                        "Node %d Inactive(anon): %8lu kB\n"
 380                        "Node %d Active(file):   %8lu kB\n"
 381                        "Node %d Inactive(file): %8lu kB\n"
 382                        "Node %d Unevictable:    %8lu kB\n"
 383                        "Node %d Mlocked:        %8lu kB\n",
 384                        nid, K(i.totalram),
 385                        nid, K(i.freeram),
 386                        nid, K(i.totalram - i.freeram),
 387                        nid, K(node_page_state(pgdat, NR_ACTIVE_ANON) +
 388                                 node_page_state(pgdat, NR_ACTIVE_FILE)),
 389                        nid, K(node_page_state(pgdat, NR_INACTIVE_ANON) +
 390                                 node_page_state(pgdat, NR_INACTIVE_FILE)),
 391                        nid, K(node_page_state(pgdat, NR_ACTIVE_ANON)),
 392                        nid, K(node_page_state(pgdat, NR_INACTIVE_ANON)),
 393                        nid, K(node_page_state(pgdat, NR_ACTIVE_FILE)),
 394                        nid, K(node_page_state(pgdat, NR_INACTIVE_FILE)),
 395                        nid, K(node_page_state(pgdat, NR_UNEVICTABLE)),
 396                        nid, K(sum_zone_node_page_state(nid, NR_MLOCK)));
 397
 398 #ifdef CONFIG_HIGHMEM
 399         n += sprintf(buf + n,
 400                        "Node %d HighTotal:      %8lu kB\n"
 401                        "Node %d HighFree:       %8lu kB\n"
 402                        "Node %d LowTotal:       %8lu kB\n"
 403                        "Node %d LowFree:        %8lu kB\n",
 404                        nid, K(i.totalhigh),
 405                        nid, K(i.freehigh),
 406                        nid, K(i.totalram - i.totalhigh),
 407                        nid, K(i.freeram - i.freehigh));
 408 #endif
 409         n += sprintf(buf + n,
 410                        "Node %d Dirty:          %8lu kB\n"
 411                        "Node %d Writeback:      %8lu kB\n"
 412                        "Node %d FilePages:      %8lu kB\n"
 413                        "Node %d Mapped:         %8lu kB\n"
 414                        "Node %d AnonPages:      %8lu kB\n"
 415                        "Node %d Shmem:          %8lu kB\n"
 416                        "Node %d KernelStack:    %8lu kB\n"
 417                        "Node %d PageTables:     %8lu kB\n"
 418                        "Node %d NFS_Unstable:   %8lu kB\n"
 419                        "Node %d Bounce:         %8lu kB\n"
 420                        "Node %d WritebackTmp:   %8lu kB\n"
 421                        "Node %d KReclaimable:   %8lu kB\n"
 422                        "Node %d Slab:           %8lu kB\n"
 423                        "Node %d SReclaimable:   %8lu kB\n"
 424                        "Node %d SUnreclaim:     %8lu kB\n"
 425 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 426                        "Node %d AnonHugePages:  %8lu kB\n"
 427                        "Node %d ShmemHugePages: %8lu kB\n"
 428                        "Node %d ShmemPmdMapped: %8lu kB\n"
 429 #endif
 430                         ,
 431                        nid, K(node_page_state(pgdat, NR_FILE_DIRTY)),
 432                        nid, K(node_page_state(pgdat, NR_WRITEBACK)),
 433                        nid, K(node_page_state(pgdat, NR_FILE_PAGES)),
 434                        nid, K(node_page_state(pgdat, NR_FILE_MAPPED)),
 435                        nid, K(node_page_state(pgdat, NR_ANON_MAPPED)),
 436                        nid, K(i.sharedram),
 437                        nid, sum_zone_node_page_state(nid, NR_KERNEL_STACK_KB),
 438                        nid, K(sum_zone_node_page_state(nid, NR_PAGETABLE)),
 439                        nid, K(node_page_state(pgdat, NR_UNSTABLE_NFS)),
 440                        nid, K(sum_zone_node_page_state(nid, NR_BOUNCE)),
 441                        nid, K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
 442                        nid, K(sreclaimable +
 443                               node_page_state(pgdat, NR_KERNEL_MISC_RECLAIMABLE)),
 444                        nid, K(sreclaimable + sunreclaimable),
 445                        nid, K(sreclaimable),
 446                        nid, K(sunreclaimable)
 447 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 448                        ,
 449                        nid, K(node_page_state(pgdat, NR_ANON_THPS) *
 450                                        HPAGE_PMD_NR),
 451                        nid, K(node_page_state(pgdat, NR_SHMEM_THPS) *
 452                                        HPAGE_PMD_NR),
 453                        nid, K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED) *
 454                                        HPAGE_PMD_NR)
 455 #endif
 456                        );
 457         n += hugetlb_report_node_meminfo(nid, buf + n);
 458         return n;
 459 }
 460
 461 #undef K
 462 static DEVICE_ATTR(meminfo, S_IRUGO, node_read_meminfo, NULL);
 463
 464 static ssize_t node_read_numastat(struct device *dev,
 465                                 struct device_attribute *attr, char *buf)
 466 {
 467         return sprintf(buf,
 468                        "numa_hit %lu\n"
 469                        "numa_miss %lu\n"
 470                        "numa_foreign %lu\n"
 471                        "interleave_hit %lu\n"
 472                        "local_node %lu\n"
 473                        "other_node %lu\n",
 474                        sum_zone_numa_state(dev->id, NUMA_HIT),
 475                        sum_zone_numa_state(dev->id, NUMA_MISS),
 476                        sum_zone_numa_state(dev->id, NUMA_FOREIGN),
 477                        sum_zone_numa_state(dev->id, NUMA_INTERLEAVE_HIT),
 478                        sum_zone_numa_state(dev->id, NUMA_LOCAL),
 479                        sum_zone_numa_state(dev->id, NUMA_OTHER));
 480 }
 481 static DEVICE_ATTR(numastat, S_IRUGO, node_read_numastat, NULL);
 482
 483 static ssize_t node_read_vmstat(struct device *dev,
 484                                 struct device_attribute *attr, char *buf)
 485 {
 486         int nid = dev->id;
 487         struct pglist_data *pgdat = NODE_DATA(nid);
 488         int i;
 489         int n = 0;
 490
 491         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
 492                 n += sprintf(buf+n, "%s %lu\n", vmstat_text[i],
 493                              sum_zone_node_page_state(nid, i));
 494
 495 #ifdef CONFIG_NUMA
 496         for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++)
 497                 n += sprintf(buf+n, "%s %lu\n",
 498                              vmstat_text[i + NR_VM_ZONE_STAT_ITEMS],
 499                              sum_zone_numa_state(nid, i));
 500 #endif
 501
 502         for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
 503                 n += sprintf(buf+n, "%s %lu\n",
 504                              vmstat_text[i + NR_VM_ZONE_STAT_ITEMS +
 505                              NR_VM_NUMA_STAT_ITEMS],
 506                              node_page_state(pgdat, i));
 507
 508         return n;
 509 }
 510 static DEVICE_ATTR(vmstat, S_IRUGO, node_read_vmstat, NULL);
 511
 512 static ssize_t node_read_distance(struct device *dev,
 513                         struct device_attribute *attr, char *buf)
 514 {
 515         int nid = dev->id;
 516         int len = 0;
 517         int i;
 518
 519         /*
 520          * buf is currently PAGE_SIZE in length and each node needs 4 chars
 521          * at the most (distance + space or newline).
 522          */
 523         BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE);
 524
 525         for_each_online_node(i)
 526                 len += sprintf(buf + len, "%s%d", i ? " " : "", node_distance(nid, i));
 527
 528         len += sprintf(buf + len, "\n");
 529         return len;
 530 }
 531 static DEVICE_ATTR(distance, S_IRUGO, node_read_distance, NULL);
 532
 533 static struct attribute *node_dev_attrs[] = {
 534         &dev_attr_cpumap.attr,
 535         &dev_attr_cpulist.attr,
 536         &dev_attr_meminfo.attr,
 537         &dev_attr_numastat.attr,
 538         &dev_attr_distance.attr,
 539         &dev_attr_vmstat.attr,
 540         NULL
 541 };
 542 ATTRIBUTE_GROUPS(node_dev);
 543
 544 #ifdef CONFIG_HUGETLBFS
 545 /*
 546  * hugetlbfs per node attributes registration interface:
 547  * When/if hugetlb[fs] subsystem initializes [sometime after this module],
 548  * it will register its per node attributes for all online nodes with
 549  * memory.  It will also call register_hugetlbfs_with_node(), below, to
 550  * register its attribute registration functions with this node driver.
 551  * Once these hooks have been initialized, the node driver will call into
 552  * the hugetlb module to [un]register attributes for hot-plugged nodes.
 553  */
 554 static node_registration_func_t __hugetlb_register_node;
 555 static node_registration_func_t __hugetlb_unregister_node;
 556
 557 static inline bool hugetlb_register_node(struct node *node)
 558 {
 559         if (__hugetlb_register_node &&
 560                         node_state(node->dev.id, N_MEMORY)) {
 561                 __hugetlb_register_node(node);
 562                 return true;
 563         }
 564         return false;
 565 }
 566
 567 static inline void hugetlb_unregister_node(struct node *node)
 568 {
 569         if (__hugetlb_unregister_node)
 570                 __hugetlb_unregister_node(node);
 571 }
 572
 573 void register_hugetlbfs_with_node(node_registration_func_t doregister,
 574                                   node_registration_func_t unregister)
 575 {
 576         __hugetlb_register_node   = doregister;
 577         __hugetlb_unregister_node = unregister;
 578 }
 579 #else
 580 static inline void hugetlb_register_node(struct node *node) {}
 581
 582 static inline void hugetlb_unregister_node(struct node *node) {}
 583 #endif
 584
 585 static void node_device_release(struct device *dev)
 586 {
 587         struct node *node = to_node(dev);
 588
 589 #if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HUGETLBFS)
 590         /*
 591          * We schedule the work only when a memory section is
 592          * onlined/offlined on this node. When we come here,
 593          * all the memory on this node has been offlined,
 594          * so we won't enqueue new work to this work.
 595          *
 596          * The work is using node->node_work, so we should
 597          * flush work before freeing the memory.
 598          */
 599         flush_work(&node->node_work);
 600 #endif
 601         kfree(node);
 602 }
 603
 604 /*
 605  * register_node - Setup a sysfs device for a node.
 606  * @num - Node number to use when creating the device.
 607  *
 608  * Initialize and register the node device.
 609  */
 610 static int register_node(struct node *node, int num)
 611 {
 612         int error;
 613
 614         node->dev.id = num;
 615         node->dev.bus = &node_subsys;
 616         node->dev.release = node_device_release;
 617         node->dev.groups = node_dev_groups;
 618         error = device_register(&node->dev);
 619
 620         if (error)
 621                 put_device(&node->dev);
 622         else {
 623                 hugetlb_register_node(node);
 624
 625                 compaction_register_node(node);
 626         }
 627         return error;
 628 }
 629
 630 /**
 631  * unregister_node - unregister a node device
 632  * @node: node going away
 633  *
 634  * Unregisters a node device @node.  All the devices on the node must be
 635  * unregistered before calling this function.
 636  */
 637 void unregister_node(struct node *node)
 638 {
 639         hugetlb_unregister_node(node);          /* no-op, if memoryless node */
 640         node_remove_accesses(node);
 641         node_remove_caches(node);
 642         device_unregister(&node->dev);
 643 }
 644
 645 struct node *node_devices[MAX_NUMNODES];
 646
 647 /*
 648  * register cpu under node
 649  */
 650 int register_cpu_under_node(unsigned int cpu, unsigned int nid)
 651 {
 652         int ret;
 653         struct device *obj;
 654
 655         if (!node_online(nid))
 656                 return 0;
 657
 658         obj = get_cpu_device(cpu);
 659         if (!obj)
 660                 return 0;
 661
 662         ret = sysfs_create_link(&node_devices[nid]->dev.kobj,
 663                                 &obj->kobj,
 664                                 kobject_name(&obj->kobj));
 665         if (ret)
 666                 return ret;
 667
 668         return sysfs_create_link(&obj->kobj,
 669                                  &node_devices[nid]->dev.kobj,
 670                                  kobject_name(&node_devices[nid]->dev.kobj));
 671 }
 672
 673 /**
 674  * register_memory_node_under_compute_node - link memory node to its compute
 675  *                                           node for a given access class.
 676  * @mem_node:   Memory node number
 677  * @cpu_node:   Cpu  node number
 678  * @access:     Access class to register
 679  *
 680  * Description:
 681  *      For use with platforms that may have separate memory and compute nodes.
 682  *      This function will export node relationships linking which memory
 683  *      initiator nodes can access memory targets at a given ranked access
 684  *      class.
 685  */
 686 int register_memory_node_under_compute_node(unsigned int mem_nid,
 687                                             unsigned int cpu_nid,
 688                                             unsigned access)
 689 {
 690         struct node *init_node, *targ_node;
 691         struct node_access_nodes *initiator, *target;
 692         int ret;
 693
 694         if (!node_online(cpu_nid) || !node_online(mem_nid))
 695                 return -ENODEV;
 696
 697         init_node = node_devices[cpu_nid];
 698         targ_node = node_devices[mem_nid];
 699         initiator = node_init_node_access(init_node, access);
 700         target = node_init_node_access(targ_node, access);
 701         if (!initiator || !target)
 702                 return -ENOMEM;
 703
 704         ret = sysfs_add_link_to_group(&initiator->dev.kobj, "targets",
 705                                       &targ_node->dev.kobj,
 706                                       dev_name(&targ_node->dev));
 707         if (ret)
 708                 return ret;
 709
 710         ret = sysfs_add_link_to_group(&target->dev.kobj, "initiators",
 711                                       &init_node->dev.kobj,
 712                                       dev_name(&init_node->dev));
 713         if (ret)
 714                 goto err;
 715
 716         return 0;
 717  err:
 718         sysfs_remove_link_from_group(&initiator->dev.kobj, "targets",
 719                                      dev_name(&targ_node->dev));
 720         return ret;
 721 }
 722
 723 int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
 724 {
 725         struct device *obj;
 726
 727         if (!node_online(nid))
 728                 return 0;
 729
 730         obj = get_cpu_device(cpu);
 731         if (!obj)
 732                 return 0;
 733
 734         sysfs_remove_link(&node_devices[nid]->dev.kobj,
 735                           kobject_name(&obj->kobj));
 736         sysfs_remove_link(&obj->kobj,
 737                           kobject_name(&node_devices[nid]->dev.kobj));
 738
 739         return 0;
 740 }
 741
 742 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
 743 static int __ref get_nid_for_pfn(unsigned long pfn)
 744 {
 745         if (!pfn_valid_within(pfn))
 746                 return -1;
 747 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
 748         if (system_state < SYSTEM_RUNNING)
 749                 return early_pfn_to_nid(pfn);
 750 #endif
 751         return pfn_to_nid(pfn);
 752 }
 753
 754 /* register memory section under specified node if it spans that node */
 755 int register_mem_sect_under_node(struct memory_block *mem_blk, void *arg)
 756 {
 757         int ret, nid = *(int *)arg;
 758         unsigned long pfn, sect_start_pfn, sect_end_pfn;
 759
 760         mem_blk->nid = nid;
 761
 762         sect_start_pfn = section_nr_to_pfn(mem_blk->start_section_nr);
 763         sect_end_pfn = section_nr_to_pfn(mem_blk->end_section_nr);
 764         sect_end_pfn += PAGES_PER_SECTION - 1;
 765         for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
 766                 int page_nid;
 767
 768                 /*
 769                  * memory block could have several absent sections from start.
 770                  * skip pfn range from absent section
 771                  */
 772                 if (!pfn_present(pfn)) {
 773                         pfn = round_down(pfn + PAGES_PER_SECTION,
 774                                          PAGES_PER_SECTION) - 1;
 775                         continue;
 776                 }
 777
 778                 /*
 779                  * We need to check if page belongs to nid only for the boot
 780                  * case, during hotplug we know that all pages in the memory
 781                  * block belong to the same node.
 782                  */
 783                 if (system_state == SYSTEM_BOOTING) {
 784                         page_nid = get_nid_for_pfn(pfn);
 785                         if (page_nid < 0)
 786                                 continue;
 787                         if (page_nid != nid)
 788                                 continue;
 789                 }
 790                 ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj,
 791                                         &mem_blk->dev.kobj,
 792                                         kobject_name(&mem_blk->dev.kobj));
 793                 if (ret)
 794                         return ret;
 795
 796                 return sysfs_create_link_nowarn(&mem_blk->dev.kobj,
 797                                 &node_devices[nid]->dev.kobj,
 798                                 kobject_name(&node_devices[nid]->dev.kobj));
 799         }
 800         /* mem section does not span the specified node */
 801         return 0;
 802 }
 803
 804 /* unregister memory section under all nodes that it spans */
 805 int unregister_mem_sect_under_nodes(struct memory_block *mem_blk,
 806                                     unsigned long phys_index)
 807 {
 808         NODEMASK_ALLOC(nodemask_t, unlinked_nodes, GFP_KERNEL);
 809         unsigned long pfn, sect_start_pfn, sect_end_pfn;
 810
 811         if (!mem_blk) {
 812                 NODEMASK_FREE(unlinked_nodes);
 813                 return -EFAULT;
 814         }
 815         if (!unlinked_nodes)
 816                 return -ENOMEM;
 817         nodes_clear(*unlinked_nodes);
 818
 819         sect_start_pfn = section_nr_to_pfn(phys_index);
 820         sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
 821         for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
 822                 int nid;
 823
 824                 nid = get_nid_for_pfn(pfn);
 825                 if (nid < 0)
 826                         continue;
 827                 if (!node_online(nid))
 828                         continue;
 829                 if (node_test_and_set(nid, *unlinked_nodes))
 830                         continue;
 831                 sysfs_remove_link(&node_devices[nid]->dev.kobj,
 832                          kobject_name(&mem_blk->dev.kobj));
 833                 sysfs_remove_link(&mem_blk->dev.kobj,
 834                          kobject_name(&node_devices[nid]->dev.kobj));
 835         }
 836         NODEMASK_FREE(unlinked_nodes);
 837         return 0;
 838 }
 839
 840 int link_mem_sections(int nid, unsigned long start_pfn, unsigned long end_pfn)
 841 {
 842         return walk_memory_range(start_pfn, end_pfn, (void *)&nid,
 843                                         register_mem_sect_under_node);
 844 }
 845
 846 #ifdef CONFIG_HUGETLBFS
 847 /*
 848  * Handle per node hstate attribute [un]registration on transistions
 849  * to/from memoryless state.
 850  */
 851 static void node_hugetlb_work(struct work_struct *work)
 852 {
 853         struct node *node = container_of(work, struct node, node_work);
 854
 855         /*
 856          * We only get here when a node transitions to/from memoryless state.
 857          * We can detect which transition occurred by examining whether the
 858          * node has memory now.  hugetlb_register_node() already check this
 859          * so we try to register the attributes.  If that fails, then the
 860          * node has transitioned to memoryless, try to unregister the
 861          * attributes.
 862          */
 863         if (!hugetlb_register_node(node))
 864                 hugetlb_unregister_node(node);
 865 }
 866
 867 static void init_node_hugetlb_work(int nid)
 868 {
 869         INIT_WORK(&node_devices[nid]->node_work, node_hugetlb_work);
 870 }
 871
 872 static int node_memory_callback(struct notifier_block *self,
 873                                 unsigned long action, void *arg)
 874 {
 875         struct memory_notify *mnb = arg;
 876         int nid = mnb->status_change_nid;
 877
 878         switch (action) {
 879         case MEM_ONLINE:
 880         case MEM_OFFLINE:
 881                 /*
 882                  * offload per node hstate [un]registration to a work thread
 883                  * when transitioning to/from memoryless state.
 884                  */
 885                 if (nid != NUMA_NO_NODE)
 886                         schedule_work(&node_devices[nid]->node_work);
 887                 break;
 888
 889         case MEM_GOING_ONLINE:
 890         case MEM_GOING_OFFLINE:
 891         case MEM_CANCEL_ONLINE:
 892         case MEM_CANCEL_OFFLINE:
 893         default:
 894                 break;
 895         }
 896
 897         return NOTIFY_OK;
 898 }
 899 #endif  /* CONFIG_HUGETLBFS */
 900 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
 901
 902 #if !defined(CONFIG_MEMORY_HOTPLUG_SPARSE) || \
 903     !defined(CONFIG_HUGETLBFS)
 904 static inline int node_memory_callback(struct notifier_block *self,
 905                                 unsigned long action, void *arg)
 906 {
 907         return NOTIFY_OK;
 908 }
 909
 910 static void init_node_hugetlb_work(int nid) { }
 911
 912 #endif
 913
 914 int __register_one_node(int nid)
 915 {
 916         int error;
 917         int cpu;
 918
 919         node_devices[nid] = kzalloc(sizeof(struct node), GFP_KERNEL);
 920         if (!node_devices[nid])
 921                 return -ENOMEM;
 922
 923         error = register_node(node_devices[nid], nid);
 924
 925         /* link cpu under this node */
 926         for_each_present_cpu(cpu) {
 927                 if (cpu_to_node(cpu) == nid)
 928                         register_cpu_under_node(cpu, nid);
 929         }
 930
 931         INIT_LIST_HEAD(&node_devices[nid]->access_list);
 932         /* initialize work queue for memory hot plug */
 933         init_node_hugetlb_work(nid);
 934         node_init_caches(nid);
 935
 936         return error;
 937 }
 938
 939 void unregister_one_node(int nid)
 940 {
 941         if (!node_devices[nid])
 942                 return;
 943
 944         unregister_node(node_devices[nid]);
 945         node_devices[nid] = NULL;
 946 }
 947
 948 /*
 949  * node states attributes
 950  */
 951
 952 static ssize_t print_nodes_state(enum node_states state, char *buf)
 953 {
 954         int n;
 955
 956         n = scnprintf(buf, PAGE_SIZE - 1, "%*pbl",
 957                       nodemask_pr_args(&node_states[state]));
 958         buf[n++] = '\n';
 959         buf[n] = '\0';
 960         return n;
 961 }
 962
 963 struct node_attr {
 964         struct device_attribute attr;
 965         enum node_states state;
 966 };
 967
 968 static ssize_t show_node_state(struct device *dev,
 969                                struct device_attribute *attr, char *buf)
 970 {
 971         struct node_attr *na = container_of(attr, struct node_attr, attr);
 972         return print_nodes_state(na->state, buf);
 973 }
 974
 975 #define _NODE_ATTR(name, state) \
 976         { __ATTR(name, 0444, show_node_state, NULL), state }
 977
 978 static struct node_attr node_state_attr[] = {
 979         [N_POSSIBLE] = _NODE_ATTR(possible, N_POSSIBLE),
 980         [N_ONLINE] = _NODE_ATTR(online, N_ONLINE),
 981         [N_NORMAL_MEMORY] = _NODE_ATTR(has_normal_memory, N_NORMAL_MEMORY),
 982 #ifdef CONFIG_HIGHMEM
 983         [N_HIGH_MEMORY] = _NODE_ATTR(has_high_memory, N_HIGH_MEMORY),
 984 #endif
 985         [N_MEMORY] = _NODE_ATTR(has_memory, N_MEMORY),
 986         [N_CPU] = _NODE_ATTR(has_cpu, N_CPU),
 987 };
 988
 989 static struct attribute *node_state_attrs[] = {
 990         &node_state_attr[N_POSSIBLE].attr.attr,
 991         &node_state_attr[N_ONLINE].attr.attr,
 992         &node_state_attr[N_NORMAL_MEMORY].attr.attr,
 993 #ifdef CONFIG_HIGHMEM
 994         &node_state_attr[N_HIGH_MEMORY].attr.attr,
 995 #endif
 996         &node_state_attr[N_MEMORY].attr.attr,
 997         &node_state_attr[N_CPU].attr.attr,
 998         NULL
 999 };
1000
1001 static struct attribute_group memory_root_attr_group = {
1002         .attrs = node_state_attrs,
1003 };
1004
1005 static const struct attribute_group *cpu_root_attr_groups[] = {
1006         &memory_root_attr_group,
1007         NULL,
1008 };
1009
1010 #define NODE_CALLBACK_PRI       2       /* lower than SLAB */
1011 static int __init register_node_type(void)
1012 {
1013         int ret;
1014
1015         BUILD_BUG_ON(ARRAY_SIZE(node_state_attr) != NR_NODE_STATES);
1016         BUILD_BUG_ON(ARRAY_SIZE(node_state_attrs)-1 != NR_NODE_STATES);
1017
1018         ret = subsys_system_register(&node_subsys, cpu_root_attr_groups);
1019         if (!ret) {
1020                 static struct notifier_block node_memory_callback_nb = {
1021                         .notifier_call = node_memory_callback,
1022                         .priority = NODE_CALLBACK_PRI,
1023                 };
1024                 register_hotmemory_notifier(&node_memory_callback_nb);
1025         }
1026
1027         /*
1028          * Note:  we're not going to unregister the node class if we fail
1029          * to register the node state class attribute files.
1030          */
1031         return ret;
1032 }
1033 postcore_initcall(register_node_type);