xref: /linux/drivers/base/node.c (revision e7d759f31ca295d589f7420719c311870bb3166f)
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 						       unsigned int access)
130 {
131 	struct node_access_nodes *access_node;
132 	struct device *dev;
133 
134 	list_for_each_entry(access_node, &node->access_list, list_node)
135 		if (access_node->access == access)
136 			return access_node;
137 
138 	access_node = kzalloc(sizeof(*access_node), GFP_KERNEL);
139 	if (!access_node)
140 		return NULL;
141 
142 	access_node->access = access;
143 	dev = &access_node->dev;
144 	dev->parent = &node->dev;
145 	dev->release = node_access_release;
146 	dev->groups = node_access_node_groups;
147 	if (dev_set_name(dev, "access%u", access))
148 		goto free;
149 
150 	if (device_register(dev))
151 		goto free_name;
152 
153 	pm_runtime_no_callbacks(dev);
154 	list_add_tail(&access_node->list_node, &node->access_list);
155 	return access_node;
156 free_name:
157 	kfree_const(dev->kobj.name);
158 free:
159 	kfree(access_node);
160 	return NULL;
161 }
162 
163 #ifdef CONFIG_HMEM_REPORTING
164 #define ACCESS_ATTR(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 			 unsigned int access)
195 {
196 	struct node_access_nodes *c;
197 	struct node *node;
198 	int i;
199 
200 	if (WARN_ON_ONCE(!node_online(nid)))
201 		return;
202 
203 	node = node_devices[nid];
204 	c = node_init_node_access(node, access);
205 	if (!c)
206 		return;
207 
208 	c->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 
219 /**
220  * struct node_cache_info - Internal tracking for memory node caches
221  * @dev:	Device represeting the cache level
222  * @node:	List element for tracking in the node
223  * @cache_attrs:Attributes for this cache level
224  */
225 struct node_cache_info {
226 	struct device dev;
227 	struct list_head node;
228 	struct node_cache_attrs cache_attrs;
229 };
230 #define to_cache_info(device) container_of(device, struct node_cache_info, dev)
231 
232 #define CACHE_ATTR(name, fmt) 						\
233 static ssize_t name##_show(struct device *dev,				\
234 			   struct device_attribute *attr,		\
235 			   char *buf)					\
236 {									\
237 	return sysfs_emit(buf, fmt "\n",				\
238 			  to_cache_info(dev)->cache_attrs.name);	\
239 }									\
240 static DEVICE_ATTR_RO(name);
241 
242 CACHE_ATTR(size, "%llu")
243 CACHE_ATTR(line_size, "%u")
244 CACHE_ATTR(indexing, "%u")
245 CACHE_ATTR(write_policy, "%u")
246 
247 static struct attribute *cache_attrs[] = {
248 	&dev_attr_indexing.attr,
249 	&dev_attr_size.attr,
250 	&dev_attr_line_size.attr,
251 	&dev_attr_write_policy.attr,
252 	NULL,
253 };
254 ATTRIBUTE_GROUPS(cache);
255 
256 static void node_cache_release(struct device *dev)
257 {
258 	kfree(dev);
259 }
260 
261 static void node_cacheinfo_release(struct device *dev)
262 {
263 	struct node_cache_info *info = to_cache_info(dev);
264 	kfree(info);
265 }
266 
267 static void node_init_cache_dev(struct node *node)
268 {
269 	struct device *dev;
270 
271 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
272 	if (!dev)
273 		return;
274 
275 	device_initialize(dev);
276 	dev->parent = &node->dev;
277 	dev->release = node_cache_release;
278 	if (dev_set_name(dev, "memory_side_cache"))
279 		goto put_device;
280 
281 	if (device_add(dev))
282 		goto put_device;
283 
284 	pm_runtime_no_callbacks(dev);
285 	node->cache_dev = dev;
286 	return;
287 put_device:
288 	put_device(dev);
289 }
290 
291 /**
292  * node_add_cache() - add cache attribute to a memory node
293  * @nid: Node identifier that has new cache attributes
294  * @cache_attrs: Attributes for the cache being added
295  */
296 void node_add_cache(unsigned int nid, struct node_cache_attrs *cache_attrs)
297 {
298 	struct node_cache_info *info;
299 	struct device *dev;
300 	struct node *node;
301 
302 	if (!node_online(nid) || !node_devices[nid])
303 		return;
304 
305 	node = node_devices[nid];
306 	list_for_each_entry(info, &node->cache_attrs, node) {
307 		if (info->cache_attrs.level == cache_attrs->level) {
308 			dev_warn(&node->dev,
309 				"attempt to add duplicate cache level:%d\n",
310 				cache_attrs->level);
311 			return;
312 		}
313 	}
314 
315 	if (!node->cache_dev)
316 		node_init_cache_dev(node);
317 	if (!node->cache_dev)
318 		return;
319 
320 	info = kzalloc(sizeof(*info), GFP_KERNEL);
321 	if (!info)
322 		return;
323 
324 	dev = &info->dev;
325 	device_initialize(dev);
326 	dev->parent = node->cache_dev;
327 	dev->release = node_cacheinfo_release;
328 	dev->groups = cache_groups;
329 	if (dev_set_name(dev, "index%d", cache_attrs->level))
330 		goto put_device;
331 
332 	info->cache_attrs = *cache_attrs;
333 	if (device_add(dev)) {
334 		dev_warn(&node->dev, "failed to add cache level:%d\n",
335 			 cache_attrs->level);
336 		goto put_device;
337 	}
338 	pm_runtime_no_callbacks(dev);
339 	list_add_tail(&info->node, &node->cache_attrs);
340 	return;
341 put_device:
342 	put_device(dev);
343 }
344 
345 static void node_remove_caches(struct node *node)
346 {
347 	struct node_cache_info *info, *next;
348 
349 	if (!node->cache_dev)
350 		return;
351 
352 	list_for_each_entry_safe(info, next, &node->cache_attrs, node) {
353 		list_del(&info->node);
354 		device_unregister(&info->dev);
355 	}
356 	device_unregister(node->cache_dev);
357 }
358 
359 static void node_init_caches(unsigned int nid)
360 {
361 	INIT_LIST_HEAD(&node_devices[nid]->cache_attrs);
362 }
363 #else
364 static void node_init_caches(unsigned int nid) { }
365 static void node_remove_caches(struct node *node) { }
366 #endif
367 
368 #define K(x) ((x) << (PAGE_SHIFT - 10))
369 static ssize_t node_read_meminfo(struct device *dev,
370 			struct device_attribute *attr, char *buf)
371 {
372 	int len = 0;
373 	int nid = dev->id;
374 	struct pglist_data *pgdat = NODE_DATA(nid);
375 	struct sysinfo i;
376 	unsigned long sreclaimable, sunreclaimable;
377 	unsigned long swapcached = 0;
378 
379 	si_meminfo_node(&i, nid);
380 	sreclaimable = node_page_state_pages(pgdat, NR_SLAB_RECLAIMABLE_B);
381 	sunreclaimable = node_page_state_pages(pgdat, NR_SLAB_UNRECLAIMABLE_B);
382 #ifdef CONFIG_SWAP
383 	swapcached = node_page_state_pages(pgdat, NR_SWAPCACHE);
384 #endif
385 	len = sysfs_emit_at(buf, len,
386 			    "Node %d MemTotal:       %8lu kB\n"
387 			    "Node %d MemFree:        %8lu kB\n"
388 			    "Node %d MemUsed:        %8lu kB\n"
389 			    "Node %d SwapCached:     %8lu kB\n"
390 			    "Node %d Active:         %8lu kB\n"
391 			    "Node %d Inactive:       %8lu kB\n"
392 			    "Node %d Active(anon):   %8lu kB\n"
393 			    "Node %d Inactive(anon): %8lu kB\n"
394 			    "Node %d Active(file):   %8lu kB\n"
395 			    "Node %d Inactive(file): %8lu kB\n"
396 			    "Node %d Unevictable:    %8lu kB\n"
397 			    "Node %d Mlocked:        %8lu kB\n",
398 			    nid, K(i.totalram),
399 			    nid, K(i.freeram),
400 			    nid, K(i.totalram - i.freeram),
401 			    nid, K(swapcached),
402 			    nid, K(node_page_state(pgdat, NR_ACTIVE_ANON) +
403 				   node_page_state(pgdat, NR_ACTIVE_FILE)),
404 			    nid, K(node_page_state(pgdat, NR_INACTIVE_ANON) +
405 				   node_page_state(pgdat, NR_INACTIVE_FILE)),
406 			    nid, K(node_page_state(pgdat, NR_ACTIVE_ANON)),
407 			    nid, K(node_page_state(pgdat, NR_INACTIVE_ANON)),
408 			    nid, K(node_page_state(pgdat, NR_ACTIVE_FILE)),
409 			    nid, K(node_page_state(pgdat, NR_INACTIVE_FILE)),
410 			    nid, K(node_page_state(pgdat, NR_UNEVICTABLE)),
411 			    nid, K(sum_zone_node_page_state(nid, NR_MLOCK)));
412 
413 #ifdef CONFIG_HIGHMEM
414 	len += sysfs_emit_at(buf, len,
415 			     "Node %d HighTotal:      %8lu kB\n"
416 			     "Node %d HighFree:       %8lu kB\n"
417 			     "Node %d LowTotal:       %8lu kB\n"
418 			     "Node %d LowFree:        %8lu kB\n",
419 			     nid, K(i.totalhigh),
420 			     nid, K(i.freehigh),
421 			     nid, K(i.totalram - i.totalhigh),
422 			     nid, K(i.freeram - i.freehigh));
423 #endif
424 	len += sysfs_emit_at(buf, len,
425 			     "Node %d Dirty:          %8lu kB\n"
426 			     "Node %d Writeback:      %8lu kB\n"
427 			     "Node %d FilePages:      %8lu kB\n"
428 			     "Node %d Mapped:         %8lu kB\n"
429 			     "Node %d AnonPages:      %8lu kB\n"
430 			     "Node %d Shmem:          %8lu kB\n"
431 			     "Node %d KernelStack:    %8lu kB\n"
432 #ifdef CONFIG_SHADOW_CALL_STACK
433 			     "Node %d ShadowCallStack:%8lu kB\n"
434 #endif
435 			     "Node %d PageTables:     %8lu kB\n"
436 			     "Node %d SecPageTables:  %8lu kB\n"
437 			     "Node %d NFS_Unstable:   %8lu kB\n"
438 			     "Node %d Bounce:         %8lu kB\n"
439 			     "Node %d WritebackTmp:   %8lu kB\n"
440 			     "Node %d KReclaimable:   %8lu kB\n"
441 			     "Node %d Slab:           %8lu kB\n"
442 			     "Node %d SReclaimable:   %8lu kB\n"
443 			     "Node %d SUnreclaim:     %8lu kB\n"
444 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
445 			     "Node %d AnonHugePages:  %8lu kB\n"
446 			     "Node %d ShmemHugePages: %8lu kB\n"
447 			     "Node %d ShmemPmdMapped: %8lu kB\n"
448 			     "Node %d FileHugePages:  %8lu kB\n"
449 			     "Node %d FilePmdMapped:  %8lu kB\n"
450 #endif
451 #ifdef CONFIG_UNACCEPTED_MEMORY
452 			     "Node %d Unaccepted:     %8lu kB\n"
453 #endif
454 			     ,
455 			     nid, K(node_page_state(pgdat, NR_FILE_DIRTY)),
456 			     nid, K(node_page_state(pgdat, NR_WRITEBACK)),
457 			     nid, K(node_page_state(pgdat, NR_FILE_PAGES)),
458 			     nid, K(node_page_state(pgdat, NR_FILE_MAPPED)),
459 			     nid, K(node_page_state(pgdat, NR_ANON_MAPPED)),
460 			     nid, K(i.sharedram),
461 			     nid, node_page_state(pgdat, NR_KERNEL_STACK_KB),
462 #ifdef CONFIG_SHADOW_CALL_STACK
463 			     nid, node_page_state(pgdat, NR_KERNEL_SCS_KB),
464 #endif
465 			     nid, K(node_page_state(pgdat, NR_PAGETABLE)),
466 			     nid, K(node_page_state(pgdat, NR_SECONDARY_PAGETABLE)),
467 			     nid, 0UL,
468 			     nid, K(sum_zone_node_page_state(nid, NR_BOUNCE)),
469 			     nid, K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
470 			     nid, K(sreclaimable +
471 				    node_page_state(pgdat, NR_KERNEL_MISC_RECLAIMABLE)),
472 			     nid, K(sreclaimable + sunreclaimable),
473 			     nid, K(sreclaimable),
474 			     nid, K(sunreclaimable)
475 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
476 			     ,
477 			     nid, K(node_page_state(pgdat, NR_ANON_THPS)),
478 			     nid, K(node_page_state(pgdat, NR_SHMEM_THPS)),
479 			     nid, K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED)),
480 			     nid, K(node_page_state(pgdat, NR_FILE_THPS)),
481 			     nid, K(node_page_state(pgdat, NR_FILE_PMDMAPPED))
482 #endif
483 #ifdef CONFIG_UNACCEPTED_MEMORY
484 			     ,
485 			     nid, K(sum_zone_node_page_state(nid, NR_UNACCEPTED))
486 #endif
487 			    );
488 	len += hugetlb_report_node_meminfo(buf, len, nid);
489 	return len;
490 }
491 
492 #undef K
493 static DEVICE_ATTR(meminfo, 0444, node_read_meminfo, NULL);
494 
495 static ssize_t node_read_numastat(struct device *dev,
496 				  struct device_attribute *attr, char *buf)
497 {
498 	fold_vm_numa_events();
499 	return sysfs_emit(buf,
500 			  "numa_hit %lu\n"
501 			  "numa_miss %lu\n"
502 			  "numa_foreign %lu\n"
503 			  "interleave_hit %lu\n"
504 			  "local_node %lu\n"
505 			  "other_node %lu\n",
506 			  sum_zone_numa_event_state(dev->id, NUMA_HIT),
507 			  sum_zone_numa_event_state(dev->id, NUMA_MISS),
508 			  sum_zone_numa_event_state(dev->id, NUMA_FOREIGN),
509 			  sum_zone_numa_event_state(dev->id, NUMA_INTERLEAVE_HIT),
510 			  sum_zone_numa_event_state(dev->id, NUMA_LOCAL),
511 			  sum_zone_numa_event_state(dev->id, NUMA_OTHER));
512 }
513 static DEVICE_ATTR(numastat, 0444, node_read_numastat, NULL);
514 
515 static ssize_t node_read_vmstat(struct device *dev,
516 				struct device_attribute *attr, char *buf)
517 {
518 	int nid = dev->id;
519 	struct pglist_data *pgdat = NODE_DATA(nid);
520 	int i;
521 	int len = 0;
522 
523 	for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
524 		len += sysfs_emit_at(buf, len, "%s %lu\n",
525 				     zone_stat_name(i),
526 				     sum_zone_node_page_state(nid, i));
527 
528 #ifdef CONFIG_NUMA
529 	fold_vm_numa_events();
530 	for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++)
531 		len += sysfs_emit_at(buf, len, "%s %lu\n",
532 				     numa_stat_name(i),
533 				     sum_zone_numa_event_state(nid, i));
534 
535 #endif
536 	for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
537 		unsigned long pages = node_page_state_pages(pgdat, i);
538 
539 		if (vmstat_item_print_in_thp(i))
540 			pages /= HPAGE_PMD_NR;
541 		len += sysfs_emit_at(buf, len, "%s %lu\n", node_stat_name(i),
542 				     pages);
543 	}
544 
545 	return len;
546 }
547 static DEVICE_ATTR(vmstat, 0444, node_read_vmstat, NULL);
548 
549 static ssize_t node_read_distance(struct device *dev,
550 				  struct device_attribute *attr, char *buf)
551 {
552 	int nid = dev->id;
553 	int len = 0;
554 	int i;
555 
556 	/*
557 	 * buf is currently PAGE_SIZE in length and each node needs 4 chars
558 	 * at the most (distance + space or newline).
559 	 */
560 	BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE);
561 
562 	for_each_online_node(i) {
563 		len += sysfs_emit_at(buf, len, "%s%d",
564 				     i ? " " : "", node_distance(nid, i));
565 	}
566 
567 	len += sysfs_emit_at(buf, len, "\n");
568 	return len;
569 }
570 static DEVICE_ATTR(distance, 0444, node_read_distance, NULL);
571 
572 static struct attribute *node_dev_attrs[] = {
573 	&dev_attr_meminfo.attr,
574 	&dev_attr_numastat.attr,
575 	&dev_attr_distance.attr,
576 	&dev_attr_vmstat.attr,
577 	NULL
578 };
579 
580 static struct bin_attribute *node_dev_bin_attrs[] = {
581 	&bin_attr_cpumap,
582 	&bin_attr_cpulist,
583 	NULL
584 };
585 
586 static const struct attribute_group node_dev_group = {
587 	.attrs = node_dev_attrs,
588 	.bin_attrs = node_dev_bin_attrs
589 };
590 
591 static const struct attribute_group *node_dev_groups[] = {
592 	&node_dev_group,
593 #ifdef CONFIG_HAVE_ARCH_NODE_DEV_GROUP
594 	&arch_node_dev_group,
595 #endif
596 #ifdef CONFIG_MEMORY_FAILURE
597 	&memory_failure_attr_group,
598 #endif
599 	NULL
600 };
601 
602 static void node_device_release(struct device *dev)
603 {
604 	kfree(to_node(dev));
605 }
606 
607 /*
608  * register_node - Setup a sysfs device for a node.
609  * @num - Node number to use when creating the device.
610  *
611  * Initialize and register the node device.
612  */
613 static int register_node(struct node *node, int num)
614 {
615 	int error;
616 
617 	node->dev.id = num;
618 	node->dev.bus = &node_subsys;
619 	node->dev.release = node_device_release;
620 	node->dev.groups = node_dev_groups;
621 	error = device_register(&node->dev);
622 
623 	if (error) {
624 		put_device(&node->dev);
625 	} else {
626 		hugetlb_register_node(node);
627 		compaction_register_node(node);
628 	}
629 
630 	return error;
631 }
632 
633 /**
634  * unregister_node - unregister a node device
635  * @node: node going away
636  *
637  * Unregisters a node device @node.  All the devices on the node must be
638  * unregistered before calling this function.
639  */
640 void unregister_node(struct node *node)
641 {
642 	hugetlb_unregister_node(node);
643 	compaction_unregister_node(node);
644 	node_remove_accesses(node);
645 	node_remove_caches(node);
646 	device_unregister(&node->dev);
647 }
648 
649 struct node *node_devices[MAX_NUMNODES];
650 
651 /*
652  * register cpu under node
653  */
654 int register_cpu_under_node(unsigned int cpu, unsigned int nid)
655 {
656 	int ret;
657 	struct device *obj;
658 
659 	if (!node_online(nid))
660 		return 0;
661 
662 	obj = get_cpu_device(cpu);
663 	if (!obj)
664 		return 0;
665 
666 	ret = sysfs_create_link(&node_devices[nid]->dev.kobj,
667 				&obj->kobj,
668 				kobject_name(&obj->kobj));
669 	if (ret)
670 		return ret;
671 
672 	return sysfs_create_link(&obj->kobj,
673 				 &node_devices[nid]->dev.kobj,
674 				 kobject_name(&node_devices[nid]->dev.kobj));
675 }
676 
677 /**
678  * register_memory_node_under_compute_node - link memory node to its compute
679  *					     node for a given access class.
680  * @mem_nid:	Memory node number
681  * @cpu_nid:	Cpu  node number
682  * @access:	Access class to register
683  *
684  * Description:
685  * 	For use with platforms that may have separate memory and compute nodes.
686  * 	This function will export node relationships linking which memory
687  * 	initiator nodes can access memory targets at a given ranked access
688  * 	class.
689  */
690 int register_memory_node_under_compute_node(unsigned int mem_nid,
691 					    unsigned int cpu_nid,
692 					    unsigned int access)
693 {
694 	struct node *init_node, *targ_node;
695 	struct node_access_nodes *initiator, *target;
696 	int ret;
697 
698 	if (!node_online(cpu_nid) || !node_online(mem_nid))
699 		return -ENODEV;
700 
701 	init_node = node_devices[cpu_nid];
702 	targ_node = node_devices[mem_nid];
703 	initiator = node_init_node_access(init_node, access);
704 	target = node_init_node_access(targ_node, access);
705 	if (!initiator || !target)
706 		return -ENOMEM;
707 
708 	ret = sysfs_add_link_to_group(&initiator->dev.kobj, "targets",
709 				      &targ_node->dev.kobj,
710 				      dev_name(&targ_node->dev));
711 	if (ret)
712 		return ret;
713 
714 	ret = sysfs_add_link_to_group(&target->dev.kobj, "initiators",
715 				      &init_node->dev.kobj,
716 				      dev_name(&init_node->dev));
717 	if (ret)
718 		goto err;
719 
720 	return 0;
721  err:
722 	sysfs_remove_link_from_group(&initiator->dev.kobj, "targets",
723 				     dev_name(&targ_node->dev));
724 	return ret;
725 }
726 
727 int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
728 {
729 	struct device *obj;
730 
731 	if (!node_online(nid))
732 		return 0;
733 
734 	obj = get_cpu_device(cpu);
735 	if (!obj)
736 		return 0;
737 
738 	sysfs_remove_link(&node_devices[nid]->dev.kobj,
739 			  kobject_name(&obj->kobj));
740 	sysfs_remove_link(&obj->kobj,
741 			  kobject_name(&node_devices[nid]->dev.kobj));
742 
743 	return 0;
744 }
745 
746 #ifdef CONFIG_MEMORY_HOTPLUG
747 static int __ref get_nid_for_pfn(unsigned long pfn)
748 {
749 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
750 	if (system_state < SYSTEM_RUNNING)
751 		return early_pfn_to_nid(pfn);
752 #endif
753 	return pfn_to_nid(pfn);
754 }
755 
756 static void do_register_memory_block_under_node(int nid,
757 						struct memory_block *mem_blk,
758 						enum meminit_context context)
759 {
760 	int ret;
761 
762 	memory_block_add_nid(mem_blk, nid, context);
763 
764 	ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj,
765 				       &mem_blk->dev.kobj,
766 				       kobject_name(&mem_blk->dev.kobj));
767 	if (ret && ret != -EEXIST)
768 		dev_err_ratelimited(&node_devices[nid]->dev,
769 				    "can't create link to %s in sysfs (%d)\n",
770 				    kobject_name(&mem_blk->dev.kobj), ret);
771 
772 	ret = sysfs_create_link_nowarn(&mem_blk->dev.kobj,
773 				&node_devices[nid]->dev.kobj,
774 				kobject_name(&node_devices[nid]->dev.kobj));
775 	if (ret && ret != -EEXIST)
776 		dev_err_ratelimited(&mem_blk->dev,
777 				    "can't create link to %s in sysfs (%d)\n",
778 				    kobject_name(&node_devices[nid]->dev.kobj),
779 				    ret);
780 }
781 
782 /* register memory section under specified node if it spans that node */
783 static int register_mem_block_under_node_early(struct memory_block *mem_blk,
784 					       void *arg)
785 {
786 	unsigned long memory_block_pfns = memory_block_size_bytes() / PAGE_SIZE;
787 	unsigned long start_pfn = section_nr_to_pfn(mem_blk->start_section_nr);
788 	unsigned long end_pfn = start_pfn + memory_block_pfns - 1;
789 	int nid = *(int *)arg;
790 	unsigned long pfn;
791 
792 	for (pfn = start_pfn; pfn <= end_pfn; pfn++) {
793 		int page_nid;
794 
795 		/*
796 		 * memory block could have several absent sections from start.
797 		 * skip pfn range from absent section
798 		 */
799 		if (!pfn_in_present_section(pfn)) {
800 			pfn = round_down(pfn + PAGES_PER_SECTION,
801 					 PAGES_PER_SECTION) - 1;
802 			continue;
803 		}
804 
805 		/*
806 		 * We need to check if page belongs to nid only at the boot
807 		 * case because node's ranges can be interleaved.
808 		 */
809 		page_nid = get_nid_for_pfn(pfn);
810 		if (page_nid < 0)
811 			continue;
812 		if (page_nid != nid)
813 			continue;
814 
815 		do_register_memory_block_under_node(nid, mem_blk, MEMINIT_EARLY);
816 		return 0;
817 	}
818 	/* mem section does not span the specified node */
819 	return 0;
820 }
821 
822 /*
823  * During hotplug we know that all pages in the memory block belong to the same
824  * node.
825  */
826 static int register_mem_block_under_node_hotplug(struct memory_block *mem_blk,
827 						 void *arg)
828 {
829 	int nid = *(int *)arg;
830 
831 	do_register_memory_block_under_node(nid, mem_blk, MEMINIT_HOTPLUG);
832 	return 0;
833 }
834 
835 /*
836  * Unregister a memory block device under the node it spans. Memory blocks
837  * with multiple nodes cannot be offlined and therefore also never be removed.
838  */
839 void unregister_memory_block_under_nodes(struct memory_block *mem_blk)
840 {
841 	if (mem_blk->nid == NUMA_NO_NODE)
842 		return;
843 
844 	sysfs_remove_link(&node_devices[mem_blk->nid]->dev.kobj,
845 			  kobject_name(&mem_blk->dev.kobj));
846 	sysfs_remove_link(&mem_blk->dev.kobj,
847 			  kobject_name(&node_devices[mem_blk->nid]->dev.kobj));
848 }
849 
850 void register_memory_blocks_under_node(int nid, unsigned long start_pfn,
851 				       unsigned long end_pfn,
852 				       enum meminit_context context)
853 {
854 	walk_memory_blocks_func_t func;
855 
856 	if (context == MEMINIT_HOTPLUG)
857 		func = register_mem_block_under_node_hotplug;
858 	else
859 		func = register_mem_block_under_node_early;
860 
861 	walk_memory_blocks(PFN_PHYS(start_pfn), PFN_PHYS(end_pfn - start_pfn),
862 			   (void *)&nid, func);
863 	return;
864 }
865 #endif /* CONFIG_MEMORY_HOTPLUG */
866 
867 int __register_one_node(int nid)
868 {
869 	int error;
870 	int cpu;
871 	struct node *node;
872 
873 	node = kzalloc(sizeof(struct node), GFP_KERNEL);
874 	if (!node)
875 		return -ENOMEM;
876 
877 	INIT_LIST_HEAD(&node->access_list);
878 	node_devices[nid] = node;
879 
880 	error = register_node(node_devices[nid], nid);
881 
882 	/* link cpu under this node */
883 	for_each_present_cpu(cpu) {
884 		if (cpu_to_node(cpu) == nid)
885 			register_cpu_under_node(cpu, nid);
886 	}
887 
888 	node_init_caches(nid);
889 
890 	return error;
891 }
892 
893 void unregister_one_node(int nid)
894 {
895 	if (!node_devices[nid])
896 		return;
897 
898 	unregister_node(node_devices[nid]);
899 	node_devices[nid] = NULL;
900 }
901 
902 /*
903  * node states attributes
904  */
905 
906 struct node_attr {
907 	struct device_attribute attr;
908 	enum node_states state;
909 };
910 
911 static ssize_t show_node_state(struct device *dev,
912 			       struct device_attribute *attr, char *buf)
913 {
914 	struct node_attr *na = container_of(attr, struct node_attr, attr);
915 
916 	return sysfs_emit(buf, "%*pbl\n",
917 			  nodemask_pr_args(&node_states[na->state]));
918 }
919 
920 #define _NODE_ATTR(name, state) \
921 	{ __ATTR(name, 0444, show_node_state, NULL), state }
922 
923 static struct node_attr node_state_attr[] = {
924 	[N_POSSIBLE] = _NODE_ATTR(possible, N_POSSIBLE),
925 	[N_ONLINE] = _NODE_ATTR(online, N_ONLINE),
926 	[N_NORMAL_MEMORY] = _NODE_ATTR(has_normal_memory, N_NORMAL_MEMORY),
927 #ifdef CONFIG_HIGHMEM
928 	[N_HIGH_MEMORY] = _NODE_ATTR(has_high_memory, N_HIGH_MEMORY),
929 #endif
930 	[N_MEMORY] = _NODE_ATTR(has_memory, N_MEMORY),
931 	[N_CPU] = _NODE_ATTR(has_cpu, N_CPU),
932 	[N_GENERIC_INITIATOR] = _NODE_ATTR(has_generic_initiator,
933 					   N_GENERIC_INITIATOR),
934 };
935 
936 static struct attribute *node_state_attrs[] = {
937 	&node_state_attr[N_POSSIBLE].attr.attr,
938 	&node_state_attr[N_ONLINE].attr.attr,
939 	&node_state_attr[N_NORMAL_MEMORY].attr.attr,
940 #ifdef CONFIG_HIGHMEM
941 	&node_state_attr[N_HIGH_MEMORY].attr.attr,
942 #endif
943 	&node_state_attr[N_MEMORY].attr.attr,
944 	&node_state_attr[N_CPU].attr.attr,
945 	&node_state_attr[N_GENERIC_INITIATOR].attr.attr,
946 	NULL
947 };
948 
949 static const struct attribute_group memory_root_attr_group = {
950 	.attrs = node_state_attrs,
951 };
952 
953 static const struct attribute_group *cpu_root_attr_groups[] = {
954 	&memory_root_attr_group,
955 	NULL,
956 };
957 
958 void __init node_dev_init(void)
959 {
960 	int ret, i;
961 
962  	BUILD_BUG_ON(ARRAY_SIZE(node_state_attr) != NR_NODE_STATES);
963  	BUILD_BUG_ON(ARRAY_SIZE(node_state_attrs)-1 != NR_NODE_STATES);
964 
965 	ret = subsys_system_register(&node_subsys, cpu_root_attr_groups);
966 	if (ret)
967 		panic("%s() failed to register subsystem: %d\n", __func__, ret);
968 
969 	/*
970 	 * Create all node devices, which will properly link the node
971 	 * to applicable memory block devices and already created cpu devices.
972 	 */
973 	for_each_online_node(i) {
974 		ret = register_one_node(i);
975 		if (ret)
976 			panic("%s() failed to add node: %d\n", __func__, ret);
977 	}
978 }
979