xref: /linux/drivers/base/node.c (revision 1a80ff0f8896750156f22dbf2d4591d79bb2a155)
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/mempolicy.h>
11 #include <linux/vmstat.h>
12 #include <linux/notifier.h>
13 #include <linux/node.h>
14 #include <linux/hugetlb.h>
15 #include <linux/compaction.h>
16 #include <linux/cpumask.h>
17 #include <linux/topology.h>
18 #include <linux/nodemask.h>
19 #include <linux/cpu.h>
20 #include <linux/device.h>
21 #include <linux/pm_runtime.h>
22 #include <linux/swap.h>
23 #include <linux/slab.h>
24 #include <linux/memblock.h>
25 
26 static const struct bus_type node_subsys = {
27 	.name = "node",
28 	.dev_name = "node",
29 };
30 
31 static inline ssize_t cpumap_read(struct file *file, struct kobject *kobj,
32 				  const struct bin_attribute *attr, char *buf,
33 				  loff_t off, size_t count)
34 {
35 	struct device *dev = kobj_to_dev(kobj);
36 	struct node *node_dev = to_node(dev);
37 	cpumask_var_t mask;
38 	ssize_t n;
39 
40 	if (!alloc_cpumask_var(&mask, GFP_KERNEL))
41 		return 0;
42 
43 	cpumask_and(mask, cpumask_of_node(node_dev->dev.id), cpu_online_mask);
44 	n = cpumap_print_bitmask_to_buf(buf, mask, off, count);
45 	free_cpumask_var(mask);
46 
47 	return n;
48 }
49 
50 static const BIN_ATTR_RO(cpumap, CPUMAP_FILE_MAX_BYTES);
51 
52 static inline ssize_t cpulist_read(struct file *file, struct kobject *kobj,
53 				   const struct bin_attribute *attr, char *buf,
54 				   loff_t off, size_t count)
55 {
56 	struct device *dev = kobj_to_dev(kobj);
57 	struct node *node_dev = to_node(dev);
58 	cpumask_var_t mask;
59 	ssize_t n;
60 
61 	if (!alloc_cpumask_var(&mask, GFP_KERNEL))
62 		return 0;
63 
64 	cpumask_and(mask, cpumask_of_node(node_dev->dev.id), cpu_online_mask);
65 	n = cpumap_print_list_to_buf(buf, mask, off, count);
66 	free_cpumask_var(mask);
67 
68 	return n;
69 }
70 
71 static const BIN_ATTR_RO(cpulist, CPULIST_FILE_MAX_BYTES);
72 
73 /**
74  * struct node_access_nodes - Access class device to hold user visible
75  * 			      relationships to other nodes.
76  * @dev:	Device for this memory access class
77  * @list_node:	List element in the node's access list
78  * @access:	The access class rank
79  * @coord:	Heterogeneous memory performance coordinates
80  */
81 struct node_access_nodes {
82 	struct device		dev;
83 	struct list_head	list_node;
84 	unsigned int		access;
85 #ifdef CONFIG_HMEM_REPORTING
86 	struct access_coordinate	coord;
87 #endif
88 };
89 #define to_access_nodes(dev) container_of(dev, struct node_access_nodes, dev)
90 
91 static struct attribute *node_init_access_node_attrs[] = {
92 	NULL,
93 };
94 
95 static struct attribute *node_targ_access_node_attrs[] = {
96 	NULL,
97 };
98 
99 static const struct attribute_group initiators = {
100 	.name	= "initiators",
101 	.attrs	= node_init_access_node_attrs,
102 };
103 
104 static const struct attribute_group targets = {
105 	.name	= "targets",
106 	.attrs	= node_targ_access_node_attrs,
107 };
108 
109 static const struct attribute_group *node_access_node_groups[] = {
110 	&initiators,
111 	&targets,
112 	NULL,
113 };
114 
115 static void node_remove_accesses(struct node *node)
116 {
117 	struct node_access_nodes *c, *cnext;
118 
119 	list_for_each_entry_safe(c, cnext, &node->access_list, list_node) {
120 		list_del(&c->list_node);
121 		device_unregister(&c->dev);
122 	}
123 }
124 
125 static void node_access_release(struct device *dev)
126 {
127 	kfree(to_access_nodes(dev));
128 }
129 
130 static struct node_access_nodes *node_init_node_access(struct node *node,
131 						       enum access_coordinate_class access)
132 {
133 	struct node_access_nodes *access_node;
134 	struct device *dev;
135 
136 	list_for_each_entry(access_node, &node->access_list, list_node)
137 		if (access_node->access == access)
138 			return access_node;
139 
140 	access_node = kzalloc(sizeof(*access_node), GFP_KERNEL);
141 	if (!access_node)
142 		return NULL;
143 
144 	access_node->access = access;
145 	dev = &access_node->dev;
146 	dev->parent = &node->dev;
147 	dev->release = node_access_release;
148 	dev->groups = node_access_node_groups;
149 	if (dev_set_name(dev, "access%u", access))
150 		goto free;
151 
152 	if (device_register(dev))
153 		goto free_name;
154 
155 	pm_runtime_no_callbacks(dev);
156 	list_add_tail(&access_node->list_node, &node->access_list);
157 	return access_node;
158 free_name:
159 	kfree_const(dev->kobj.name);
160 free:
161 	kfree(access_node);
162 	return NULL;
163 }
164 
165 #ifdef CONFIG_HMEM_REPORTING
166 #define ACCESS_ATTR(property)						\
167 static ssize_t property##_show(struct device *dev,			\
168 			   struct device_attribute *attr,		\
169 			   char *buf)					\
170 {									\
171 	return sysfs_emit(buf, "%u\n",					\
172 			  to_access_nodes(dev)->coord.property);	\
173 }									\
174 static DEVICE_ATTR_RO(property)
175 
176 ACCESS_ATTR(read_bandwidth);
177 ACCESS_ATTR(read_latency);
178 ACCESS_ATTR(write_bandwidth);
179 ACCESS_ATTR(write_latency);
180 
181 static struct attribute *access_attrs[] = {
182 	&dev_attr_read_bandwidth.attr,
183 	&dev_attr_read_latency.attr,
184 	&dev_attr_write_bandwidth.attr,
185 	&dev_attr_write_latency.attr,
186 	NULL,
187 };
188 
189 /**
190  * node_set_perf_attrs - Set the performance values for given access class
191  * @nid: Node identifier to be set
192  * @coord: Heterogeneous memory performance coordinates
193  * @access: The access class the for the given attributes
194  */
195 void node_set_perf_attrs(unsigned int nid, struct access_coordinate *coord,
196 			 enum access_coordinate_class access)
197 {
198 	struct node_access_nodes *c;
199 	struct node *node;
200 	int i;
201 
202 	if (WARN_ON_ONCE(!node_online(nid)))
203 		return;
204 
205 	node = node_devices[nid];
206 	c = node_init_node_access(node, access);
207 	if (!c)
208 		return;
209 
210 	c->coord = *coord;
211 	for (i = 0; access_attrs[i] != NULL; i++) {
212 		if (sysfs_add_file_to_group(&c->dev.kobj, access_attrs[i],
213 					    "initiators")) {
214 			pr_info("failed to add performance attribute to node %d\n",
215 				nid);
216 			break;
217 		}
218 	}
219 
220 	/* When setting CPU access coordinates, update mempolicy */
221 	if (access == ACCESS_COORDINATE_CPU) {
222 		if (mempolicy_set_node_perf(nid, coord)) {
223 			pr_info("failed to set mempolicy attrs for node %d\n",
224 				nid);
225 		}
226 	}
227 }
228 EXPORT_SYMBOL_GPL(node_set_perf_attrs);
229 
230 /**
231  * struct node_cache_info - Internal tracking for memory node caches
232  * @dev:	Device represeting the cache level
233  * @node:	List element for tracking in the node
234  * @cache_attrs:Attributes for this cache level
235  */
236 struct node_cache_info {
237 	struct device dev;
238 	struct list_head node;
239 	struct node_cache_attrs cache_attrs;
240 };
241 #define to_cache_info(device) container_of(device, struct node_cache_info, dev)
242 
243 #define CACHE_ATTR(name, fmt) 						\
244 static ssize_t name##_show(struct device *dev,				\
245 			   struct device_attribute *attr,		\
246 			   char *buf)					\
247 {									\
248 	return sysfs_emit(buf, fmt "\n",				\
249 			  to_cache_info(dev)->cache_attrs.name);	\
250 }									\
251 static DEVICE_ATTR_RO(name);
252 
253 CACHE_ATTR(size, "%llu")
254 CACHE_ATTR(line_size, "%u")
255 CACHE_ATTR(indexing, "%u")
256 CACHE_ATTR(write_policy, "%u")
257 CACHE_ATTR(address_mode, "%#x")
258 
259 static struct attribute *cache_attrs[] = {
260 	&dev_attr_indexing.attr,
261 	&dev_attr_size.attr,
262 	&dev_attr_line_size.attr,
263 	&dev_attr_write_policy.attr,
264 	&dev_attr_address_mode.attr,
265 	NULL,
266 };
267 ATTRIBUTE_GROUPS(cache);
268 
269 static void node_cache_release(struct device *dev)
270 {
271 	kfree(dev);
272 }
273 
274 static void node_cacheinfo_release(struct device *dev)
275 {
276 	struct node_cache_info *info = to_cache_info(dev);
277 	kfree(info);
278 }
279 
280 static void node_init_cache_dev(struct node *node)
281 {
282 	struct device *dev;
283 
284 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
285 	if (!dev)
286 		return;
287 
288 	device_initialize(dev);
289 	dev->parent = &node->dev;
290 	dev->release = node_cache_release;
291 	if (dev_set_name(dev, "memory_side_cache"))
292 		goto put_device;
293 
294 	if (device_add(dev))
295 		goto put_device;
296 
297 	pm_runtime_no_callbacks(dev);
298 	node->cache_dev = dev;
299 	return;
300 put_device:
301 	put_device(dev);
302 }
303 
304 /**
305  * node_add_cache() - add cache attribute to a memory node
306  * @nid: Node identifier that has new cache attributes
307  * @cache_attrs: Attributes for the cache being added
308  */
309 void node_add_cache(unsigned int nid, struct node_cache_attrs *cache_attrs)
310 {
311 	struct node_cache_info *info;
312 	struct device *dev;
313 	struct node *node;
314 
315 	if (!node_online(nid) || !node_devices[nid])
316 		return;
317 
318 	node = node_devices[nid];
319 	list_for_each_entry(info, &node->cache_attrs, node) {
320 		if (info->cache_attrs.level == cache_attrs->level) {
321 			dev_warn(&node->dev,
322 				"attempt to add duplicate cache level:%d\n",
323 				cache_attrs->level);
324 			return;
325 		}
326 	}
327 
328 	if (!node->cache_dev)
329 		node_init_cache_dev(node);
330 	if (!node->cache_dev)
331 		return;
332 
333 	info = kzalloc(sizeof(*info), GFP_KERNEL);
334 	if (!info)
335 		return;
336 
337 	dev = &info->dev;
338 	device_initialize(dev);
339 	dev->parent = node->cache_dev;
340 	dev->release = node_cacheinfo_release;
341 	dev->groups = cache_groups;
342 	if (dev_set_name(dev, "index%d", cache_attrs->level))
343 		goto put_device;
344 
345 	info->cache_attrs = *cache_attrs;
346 	if (device_add(dev)) {
347 		dev_warn(&node->dev, "failed to add cache level:%d\n",
348 			 cache_attrs->level);
349 		goto put_device;
350 	}
351 	pm_runtime_no_callbacks(dev);
352 	list_add_tail(&info->node, &node->cache_attrs);
353 	return;
354 put_device:
355 	put_device(dev);
356 }
357 
358 static void node_remove_caches(struct node *node)
359 {
360 	struct node_cache_info *info, *next;
361 
362 	if (!node->cache_dev)
363 		return;
364 
365 	list_for_each_entry_safe(info, next, &node->cache_attrs, node) {
366 		list_del(&info->node);
367 		device_unregister(&info->dev);
368 	}
369 	device_unregister(node->cache_dev);
370 }
371 
372 static void node_init_caches(unsigned int nid)
373 {
374 	INIT_LIST_HEAD(&node_devices[nid]->cache_attrs);
375 }
376 #else
377 static void node_init_caches(unsigned int nid) { }
378 static void node_remove_caches(struct node *node) { }
379 #endif
380 
381 #define K(x) ((x) << (PAGE_SHIFT - 10))
382 static ssize_t node_read_meminfo(struct device *dev,
383 			struct device_attribute *attr, char *buf)
384 {
385 	int len = 0;
386 	int nid = dev->id;
387 	struct pglist_data *pgdat = NODE_DATA(nid);
388 	struct sysinfo i;
389 	unsigned long sreclaimable, sunreclaimable;
390 	unsigned long swapcached = 0;
391 
392 	si_meminfo_node(&i, nid);
393 	sreclaimable = node_page_state_pages(pgdat, NR_SLAB_RECLAIMABLE_B);
394 	sunreclaimable = node_page_state_pages(pgdat, NR_SLAB_UNRECLAIMABLE_B);
395 #ifdef CONFIG_SWAP
396 	swapcached = node_page_state_pages(pgdat, NR_SWAPCACHE);
397 #endif
398 	len = sysfs_emit_at(buf, len,
399 			    "Node %d MemTotal:       %8lu kB\n"
400 			    "Node %d MemFree:        %8lu kB\n"
401 			    "Node %d MemUsed:        %8lu kB\n"
402 			    "Node %d SwapCached:     %8lu kB\n"
403 			    "Node %d Active:         %8lu kB\n"
404 			    "Node %d Inactive:       %8lu kB\n"
405 			    "Node %d Active(anon):   %8lu kB\n"
406 			    "Node %d Inactive(anon): %8lu kB\n"
407 			    "Node %d Active(file):   %8lu kB\n"
408 			    "Node %d Inactive(file): %8lu kB\n"
409 			    "Node %d Unevictable:    %8lu kB\n"
410 			    "Node %d Mlocked:        %8lu kB\n",
411 			    nid, K(i.totalram),
412 			    nid, K(i.freeram),
413 			    nid, K(i.totalram - i.freeram),
414 			    nid, K(swapcached),
415 			    nid, K(node_page_state(pgdat, NR_ACTIVE_ANON) +
416 				   node_page_state(pgdat, NR_ACTIVE_FILE)),
417 			    nid, K(node_page_state(pgdat, NR_INACTIVE_ANON) +
418 				   node_page_state(pgdat, NR_INACTIVE_FILE)),
419 			    nid, K(node_page_state(pgdat, NR_ACTIVE_ANON)),
420 			    nid, K(node_page_state(pgdat, NR_INACTIVE_ANON)),
421 			    nid, K(node_page_state(pgdat, NR_ACTIVE_FILE)),
422 			    nid, K(node_page_state(pgdat, NR_INACTIVE_FILE)),
423 			    nid, K(node_page_state(pgdat, NR_UNEVICTABLE)),
424 			    nid, K(sum_zone_node_page_state(nid, NR_MLOCK)));
425 
426 #ifdef CONFIG_HIGHMEM
427 	len += sysfs_emit_at(buf, len,
428 			     "Node %d HighTotal:      %8lu kB\n"
429 			     "Node %d HighFree:       %8lu kB\n"
430 			     "Node %d LowTotal:       %8lu kB\n"
431 			     "Node %d LowFree:        %8lu kB\n",
432 			     nid, K(i.totalhigh),
433 			     nid, K(i.freehigh),
434 			     nid, K(i.totalram - i.totalhigh),
435 			     nid, K(i.freeram - i.freehigh));
436 #endif
437 	len += sysfs_emit_at(buf, len,
438 			     "Node %d Dirty:          %8lu kB\n"
439 			     "Node %d Writeback:      %8lu kB\n"
440 			     "Node %d FilePages:      %8lu kB\n"
441 			     "Node %d Mapped:         %8lu kB\n"
442 			     "Node %d AnonPages:      %8lu kB\n"
443 			     "Node %d Shmem:          %8lu kB\n"
444 			     "Node %d KernelStack:    %8lu kB\n"
445 #ifdef CONFIG_SHADOW_CALL_STACK
446 			     "Node %d ShadowCallStack:%8lu kB\n"
447 #endif
448 			     "Node %d PageTables:     %8lu kB\n"
449 			     "Node %d SecPageTables:  %8lu kB\n"
450 			     "Node %d NFS_Unstable:   %8lu kB\n"
451 			     "Node %d Bounce:         %8lu kB\n"
452 			     "Node %d WritebackTmp:   %8lu kB\n"
453 			     "Node %d KReclaimable:   %8lu kB\n"
454 			     "Node %d Slab:           %8lu kB\n"
455 			     "Node %d SReclaimable:   %8lu kB\n"
456 			     "Node %d SUnreclaim:     %8lu kB\n"
457 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
458 			     "Node %d AnonHugePages:  %8lu kB\n"
459 			     "Node %d ShmemHugePages: %8lu kB\n"
460 			     "Node %d ShmemPmdMapped: %8lu kB\n"
461 			     "Node %d FileHugePages:  %8lu kB\n"
462 			     "Node %d FilePmdMapped:  %8lu kB\n"
463 #endif
464 #ifdef CONFIG_UNACCEPTED_MEMORY
465 			     "Node %d Unaccepted:     %8lu kB\n"
466 #endif
467 			     ,
468 			     nid, K(node_page_state(pgdat, NR_FILE_DIRTY)),
469 			     nid, K(node_page_state(pgdat, NR_WRITEBACK)),
470 			     nid, K(node_page_state(pgdat, NR_FILE_PAGES)),
471 			     nid, K(node_page_state(pgdat, NR_FILE_MAPPED)),
472 			     nid, K(node_page_state(pgdat, NR_ANON_MAPPED)),
473 			     nid, K(i.sharedram),
474 			     nid, node_page_state(pgdat, NR_KERNEL_STACK_KB),
475 #ifdef CONFIG_SHADOW_CALL_STACK
476 			     nid, node_page_state(pgdat, NR_KERNEL_SCS_KB),
477 #endif
478 			     nid, K(node_page_state(pgdat, NR_PAGETABLE)),
479 			     nid, K(node_page_state(pgdat, NR_SECONDARY_PAGETABLE)),
480 			     nid, 0UL,
481 			     nid, 0UL,
482 			     nid, K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
483 			     nid, K(sreclaimable +
484 				    node_page_state(pgdat, NR_KERNEL_MISC_RECLAIMABLE)),
485 			     nid, K(sreclaimable + sunreclaimable),
486 			     nid, K(sreclaimable),
487 			     nid, K(sunreclaimable)
488 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
489 			     ,
490 			     nid, K(node_page_state(pgdat, NR_ANON_THPS)),
491 			     nid, K(node_page_state(pgdat, NR_SHMEM_THPS)),
492 			     nid, K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED)),
493 			     nid, K(node_page_state(pgdat, NR_FILE_THPS)),
494 			     nid, K(node_page_state(pgdat, NR_FILE_PMDMAPPED))
495 #endif
496 #ifdef CONFIG_UNACCEPTED_MEMORY
497 			     ,
498 			     nid, K(sum_zone_node_page_state(nid, NR_UNACCEPTED))
499 #endif
500 			    );
501 	len += hugetlb_report_node_meminfo(buf, len, nid);
502 	return len;
503 }
504 
505 #undef K
506 static DEVICE_ATTR(meminfo, 0444, node_read_meminfo, NULL);
507 
508 static ssize_t node_read_numastat(struct device *dev,
509 				  struct device_attribute *attr, char *buf)
510 {
511 	fold_vm_numa_events();
512 	return sysfs_emit(buf,
513 			  "numa_hit %lu\n"
514 			  "numa_miss %lu\n"
515 			  "numa_foreign %lu\n"
516 			  "interleave_hit %lu\n"
517 			  "local_node %lu\n"
518 			  "other_node %lu\n",
519 			  sum_zone_numa_event_state(dev->id, NUMA_HIT),
520 			  sum_zone_numa_event_state(dev->id, NUMA_MISS),
521 			  sum_zone_numa_event_state(dev->id, NUMA_FOREIGN),
522 			  sum_zone_numa_event_state(dev->id, NUMA_INTERLEAVE_HIT),
523 			  sum_zone_numa_event_state(dev->id, NUMA_LOCAL),
524 			  sum_zone_numa_event_state(dev->id, NUMA_OTHER));
525 }
526 static DEVICE_ATTR(numastat, 0444, node_read_numastat, NULL);
527 
528 static ssize_t node_read_vmstat(struct device *dev,
529 				struct device_attribute *attr, char *buf)
530 {
531 	int nid = dev->id;
532 	struct pglist_data *pgdat = NODE_DATA(nid);
533 	int i;
534 	int len = 0;
535 
536 	for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
537 		len += sysfs_emit_at(buf, len, "%s %lu\n",
538 				     zone_stat_name(i),
539 				     sum_zone_node_page_state(nid, i));
540 
541 #ifdef CONFIG_NUMA
542 	fold_vm_numa_events();
543 	for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++)
544 		len += sysfs_emit_at(buf, len, "%s %lu\n",
545 				     numa_stat_name(i),
546 				     sum_zone_numa_event_state(nid, i));
547 
548 #endif
549 	for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
550 		unsigned long pages = node_page_state_pages(pgdat, i);
551 
552 		if (vmstat_item_print_in_thp(i))
553 			pages /= HPAGE_PMD_NR;
554 		len += sysfs_emit_at(buf, len, "%s %lu\n", node_stat_name(i),
555 				     pages);
556 	}
557 
558 	return len;
559 }
560 static DEVICE_ATTR(vmstat, 0444, node_read_vmstat, NULL);
561 
562 static ssize_t node_read_distance(struct device *dev,
563 				  struct device_attribute *attr, char *buf)
564 {
565 	int nid = dev->id;
566 	int len = 0;
567 	int i;
568 
569 	/*
570 	 * buf is currently PAGE_SIZE in length and each node needs 4 chars
571 	 * at the most (distance + space or newline).
572 	 */
573 	BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE);
574 
575 	for_each_online_node(i) {
576 		len += sysfs_emit_at(buf, len, "%s%d",
577 				     i ? " " : "", node_distance(nid, i));
578 	}
579 
580 	len += sysfs_emit_at(buf, len, "\n");
581 	return len;
582 }
583 static DEVICE_ATTR(distance, 0444, node_read_distance, NULL);
584 
585 static struct attribute *node_dev_attrs[] = {
586 	&dev_attr_meminfo.attr,
587 	&dev_attr_numastat.attr,
588 	&dev_attr_distance.attr,
589 	&dev_attr_vmstat.attr,
590 	NULL
591 };
592 
593 static const struct bin_attribute *node_dev_bin_attrs[] = {
594 	&bin_attr_cpumap,
595 	&bin_attr_cpulist,
596 	NULL
597 };
598 
599 static const struct attribute_group node_dev_group = {
600 	.attrs = node_dev_attrs,
601 	.bin_attrs_new = node_dev_bin_attrs,
602 };
603 
604 static const struct attribute_group *node_dev_groups[] = {
605 	&node_dev_group,
606 #ifdef CONFIG_HAVE_ARCH_NODE_DEV_GROUP
607 	&arch_node_dev_group,
608 #endif
609 #ifdef CONFIG_MEMORY_FAILURE
610 	&memory_failure_attr_group,
611 #endif
612 	NULL
613 };
614 
615 static void node_device_release(struct device *dev)
616 {
617 	kfree(to_node(dev));
618 }
619 
620 /*
621  * register_node - Setup a sysfs device for a node.
622  * @num - Node number to use when creating the device.
623  *
624  * Initialize and register the node device.
625  */
626 static int register_node(struct node *node, int num)
627 {
628 	int error;
629 
630 	node->dev.id = num;
631 	node->dev.bus = &node_subsys;
632 	node->dev.release = node_device_release;
633 	node->dev.groups = node_dev_groups;
634 	error = device_register(&node->dev);
635 
636 	if (error) {
637 		put_device(&node->dev);
638 	} else {
639 		hugetlb_register_node(node);
640 		compaction_register_node(node);
641 	}
642 
643 	return error;
644 }
645 
646 /**
647  * unregister_node - unregister a node device
648  * @node: node going away
649  *
650  * Unregisters a node device @node.  All the devices on the node must be
651  * unregistered before calling this function.
652  */
653 void unregister_node(struct node *node)
654 {
655 	hugetlb_unregister_node(node);
656 	compaction_unregister_node(node);
657 	node_remove_accesses(node);
658 	node_remove_caches(node);
659 	device_unregister(&node->dev);
660 }
661 
662 struct node *node_devices[MAX_NUMNODES];
663 
664 /*
665  * register cpu under node
666  */
667 int register_cpu_under_node(unsigned int cpu, unsigned int nid)
668 {
669 	int ret;
670 	struct device *obj;
671 
672 	if (!node_online(nid))
673 		return 0;
674 
675 	obj = get_cpu_device(cpu);
676 	if (!obj)
677 		return 0;
678 
679 	ret = sysfs_create_link(&node_devices[nid]->dev.kobj,
680 				&obj->kobj,
681 				kobject_name(&obj->kobj));
682 	if (ret)
683 		return ret;
684 
685 	return sysfs_create_link(&obj->kobj,
686 				 &node_devices[nid]->dev.kobj,
687 				 kobject_name(&node_devices[nid]->dev.kobj));
688 }
689 
690 /**
691  * register_memory_node_under_compute_node - link memory node to its compute
692  *					     node for a given access class.
693  * @mem_nid:	Memory node number
694  * @cpu_nid:	Cpu  node number
695  * @access:	Access class to register
696  *
697  * Description:
698  * 	For use with platforms that may have separate memory and compute nodes.
699  * 	This function will export node relationships linking which memory
700  * 	initiator nodes can access memory targets at a given ranked access
701  * 	class.
702  */
703 int register_memory_node_under_compute_node(unsigned int mem_nid,
704 					    unsigned int cpu_nid,
705 					    enum access_coordinate_class access)
706 {
707 	struct node *init_node, *targ_node;
708 	struct node_access_nodes *initiator, *target;
709 	int ret;
710 
711 	if (!node_online(cpu_nid) || !node_online(mem_nid))
712 		return -ENODEV;
713 
714 	init_node = node_devices[cpu_nid];
715 	targ_node = node_devices[mem_nid];
716 	initiator = node_init_node_access(init_node, access);
717 	target = node_init_node_access(targ_node, access);
718 	if (!initiator || !target)
719 		return -ENOMEM;
720 
721 	ret = sysfs_add_link_to_group(&initiator->dev.kobj, "targets",
722 				      &targ_node->dev.kobj,
723 				      dev_name(&targ_node->dev));
724 	if (ret)
725 		return ret;
726 
727 	ret = sysfs_add_link_to_group(&target->dev.kobj, "initiators",
728 				      &init_node->dev.kobj,
729 				      dev_name(&init_node->dev));
730 	if (ret)
731 		goto err;
732 
733 	return 0;
734  err:
735 	sysfs_remove_link_from_group(&initiator->dev.kobj, "targets",
736 				     dev_name(&targ_node->dev));
737 	return ret;
738 }
739 
740 int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
741 {
742 	struct device *obj;
743 
744 	if (!node_online(nid))
745 		return 0;
746 
747 	obj = get_cpu_device(cpu);
748 	if (!obj)
749 		return 0;
750 
751 	sysfs_remove_link(&node_devices[nid]->dev.kobj,
752 			  kobject_name(&obj->kobj));
753 	sysfs_remove_link(&obj->kobj,
754 			  kobject_name(&node_devices[nid]->dev.kobj));
755 
756 	return 0;
757 }
758 
759 #ifdef CONFIG_MEMORY_HOTPLUG
760 static void do_register_memory_block_under_node(int nid,
761 						struct memory_block *mem_blk,
762 						enum meminit_context context)
763 {
764 	int ret;
765 
766 	memory_block_add_nid(mem_blk, nid, context);
767 
768 	ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj,
769 				       &mem_blk->dev.kobj,
770 				       kobject_name(&mem_blk->dev.kobj));
771 	if (ret && ret != -EEXIST)
772 		dev_err_ratelimited(&node_devices[nid]->dev,
773 				    "can't create link to %s in sysfs (%d)\n",
774 				    kobject_name(&mem_blk->dev.kobj), ret);
775 
776 	ret = sysfs_create_link_nowarn(&mem_blk->dev.kobj,
777 				&node_devices[nid]->dev.kobj,
778 				kobject_name(&node_devices[nid]->dev.kobj));
779 	if (ret && ret != -EEXIST)
780 		dev_err_ratelimited(&mem_blk->dev,
781 				    "can't create link to %s in sysfs (%d)\n",
782 				    kobject_name(&node_devices[nid]->dev.kobj),
783 				    ret);
784 }
785 
786 /*
787  * During hotplug we know that all pages in the memory block belong to the same
788  * node.
789  */
790 static int register_mem_block_under_node_hotplug(struct memory_block *mem_blk,
791 						 void *arg)
792 {
793 	int nid = *(int *)arg;
794 
795 	do_register_memory_block_under_node(nid, mem_blk, MEMINIT_HOTPLUG);
796 	return 0;
797 }
798 
799 /*
800  * Unregister a memory block device under the node it spans. Memory blocks
801  * with multiple nodes cannot be offlined and therefore also never be removed.
802  */
803 void unregister_memory_block_under_nodes(struct memory_block *mem_blk)
804 {
805 	if (mem_blk->nid == NUMA_NO_NODE)
806 		return;
807 
808 	sysfs_remove_link(&node_devices[mem_blk->nid]->dev.kobj,
809 			  kobject_name(&mem_blk->dev.kobj));
810 	sysfs_remove_link(&mem_blk->dev.kobj,
811 			  kobject_name(&node_devices[mem_blk->nid]->dev.kobj));
812 }
813 
814 /* register all memory blocks under the corresponding nodes */
815 static void register_memory_blocks_under_nodes(void)
816 {
817 	struct memblock_region *r;
818 
819 	for_each_mem_region(r) {
820 		const unsigned long start_block_id = phys_to_block_id(r->base);
821 		const unsigned long end_block_id = phys_to_block_id(r->base + r->size - 1);
822 		const int nid = memblock_get_region_node(r);
823 		unsigned long block_id;
824 
825 		if (!node_online(nid))
826 			continue;
827 
828 		for (block_id = start_block_id; block_id <= end_block_id; block_id++) {
829 			struct memory_block *mem;
830 
831 			mem = find_memory_block_by_id(block_id);
832 			if (!mem)
833 				continue;
834 
835 			do_register_memory_block_under_node(nid, mem, MEMINIT_EARLY);
836 			put_device(&mem->dev);
837 		}
838 
839 	}
840 }
841 
842 void register_memory_blocks_under_node_hotplug(int nid, unsigned long start_pfn,
843 					       unsigned long end_pfn)
844 {
845 	walk_memory_blocks(PFN_PHYS(start_pfn), PFN_PHYS(end_pfn - start_pfn),
846 			   (void *)&nid, register_mem_block_under_node_hotplug);
847 	return;
848 }
849 #endif /* CONFIG_MEMORY_HOTPLUG */
850 
851 int register_one_node(int nid)
852 {
853 	int error;
854 	int cpu;
855 	struct node *node;
856 
857 	node = kzalloc(sizeof(struct node), GFP_KERNEL);
858 	if (!node)
859 		return -ENOMEM;
860 
861 	INIT_LIST_HEAD(&node->access_list);
862 	node_devices[nid] = node;
863 
864 	error = register_node(node_devices[nid], nid);
865 
866 	/* link cpu under this node */
867 	for_each_present_cpu(cpu) {
868 		if (cpu_to_node(cpu) == nid)
869 			register_cpu_under_node(cpu, nid);
870 	}
871 
872 	node_init_caches(nid);
873 
874 	return error;
875 }
876 
877 void unregister_one_node(int nid)
878 {
879 	if (!node_devices[nid])
880 		return;
881 
882 	unregister_node(node_devices[nid]);
883 	node_devices[nid] = NULL;
884 }
885 
886 /*
887  * node states attributes
888  */
889 
890 struct node_attr {
891 	struct device_attribute attr;
892 	enum node_states state;
893 };
894 
895 static ssize_t show_node_state(struct device *dev,
896 			       struct device_attribute *attr, char *buf)
897 {
898 	struct node_attr *na = container_of(attr, struct node_attr, attr);
899 
900 	return sysfs_emit(buf, "%*pbl\n",
901 			  nodemask_pr_args(&node_states[na->state]));
902 }
903 
904 #define _NODE_ATTR(name, state) \
905 	{ __ATTR(name, 0444, show_node_state, NULL), state }
906 
907 static struct node_attr node_state_attr[] = {
908 	[N_POSSIBLE] = _NODE_ATTR(possible, N_POSSIBLE),
909 	[N_ONLINE] = _NODE_ATTR(online, N_ONLINE),
910 	[N_NORMAL_MEMORY] = _NODE_ATTR(has_normal_memory, N_NORMAL_MEMORY),
911 #ifdef CONFIG_HIGHMEM
912 	[N_HIGH_MEMORY] = _NODE_ATTR(has_high_memory, N_HIGH_MEMORY),
913 #endif
914 	[N_MEMORY] = _NODE_ATTR(has_memory, N_MEMORY),
915 	[N_CPU] = _NODE_ATTR(has_cpu, N_CPU),
916 	[N_GENERIC_INITIATOR] = _NODE_ATTR(has_generic_initiator,
917 					   N_GENERIC_INITIATOR),
918 };
919 
920 static struct attribute *node_state_attrs[] = {
921 	&node_state_attr[N_POSSIBLE].attr.attr,
922 	&node_state_attr[N_ONLINE].attr.attr,
923 	&node_state_attr[N_NORMAL_MEMORY].attr.attr,
924 #ifdef CONFIG_HIGHMEM
925 	&node_state_attr[N_HIGH_MEMORY].attr.attr,
926 #endif
927 	&node_state_attr[N_MEMORY].attr.attr,
928 	&node_state_attr[N_CPU].attr.attr,
929 	&node_state_attr[N_GENERIC_INITIATOR].attr.attr,
930 	NULL
931 };
932 
933 static const struct attribute_group memory_root_attr_group = {
934 	.attrs = node_state_attrs,
935 };
936 
937 static const struct attribute_group *cpu_root_attr_groups[] = {
938 	&memory_root_attr_group,
939 	NULL,
940 };
941 
942 void __init node_dev_init(void)
943 {
944 	int ret, i;
945 
946  	BUILD_BUG_ON(ARRAY_SIZE(node_state_attr) != NR_NODE_STATES);
947  	BUILD_BUG_ON(ARRAY_SIZE(node_state_attrs)-1 != NR_NODE_STATES);
948 
949 	ret = subsys_system_register(&node_subsys, cpu_root_attr_groups);
950 	if (ret)
951 		panic("%s() failed to register subsystem: %d\n", __func__, ret);
952 
953 	/*
954 	 * Create all node devices, which will properly link the node
955 	 * to already created cpu devices.
956 	 */
957 	for_each_online_node(i) {
958 		ret =  register_one_node(i);
959 		if (ret)
960 			panic("%s() failed to add node: %d\n", __func__, ret);
961 	}
962 
963 	register_memory_blocks_under_nodes();
964 }
965