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