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
24static const struct bus_type node_subsys = {
25 .name = "node",
26 .dev_name = "node",
27};
28
29static 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: &mask, GFP_KERNEL))
39 return 0;
40
41 cpumask_and(dstp: mask, src1p: cpumask_of_node(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
48static BIN_ATTR_RO(cpumap, CPUMAP_FILE_MAX_BYTES);
49
50static 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: &mask, GFP_KERNEL))
60 return 0;
61
62 cpumask_and(dstp: mask, src1p: cpumask_of_node(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
69static 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 */
79struct 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
89static struct attribute *node_init_access_node_attrs[] = {
90 NULL,
91};
92
93static struct attribute *node_targ_access_node_attrs[] = {
94 NULL,
95};
96
97static const struct attribute_group initiators = {
98 .name = "initiators",
99 .attrs = node_init_access_node_attrs,
100};
101
102static const struct attribute_group targets = {
103 .name = "targets",
104 .attrs = node_targ_access_node_attrs,
105};
106
107static const struct attribute_group *node_access_node_groups[] = {
108 &initiators,
109 &targets,
110 NULL,
111};
112
113static 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(entry: &c->list_node);
119 device_unregister(dev: &c->dev);
120 }
121}
122
123static void node_access_release(struct device *dev)
124{
125 kfree(to_access_nodes(dev));
126}
127
128static struct node_access_nodes *node_init_node_access(struct node *node,
129 enum access_coordinate_class access)
130{
131 struct node_access_nodes *access_node;
132 struct device *dev;
133
134 list_for_each_entry(access_node, &node->access_list, list_node)
135 if (access_node->access == access)
136 return access_node;
137
138 access_node = kzalloc(size: 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, name: "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(new: &access_node->list_node, head: &node->access_list);
155 return access_node;
156free_name:
157 kfree_const(x: dev->kobj.name);
158free:
159 kfree(objp: access_node);
160 return NULL;
161}
162
163#ifdef CONFIG_HMEM_REPORTING
164#define ACCESS_ATTR(property) \
165static 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} \
172static DEVICE_ATTR_RO(property)
173
174ACCESS_ATTR(read_bandwidth);
175ACCESS_ATTR(read_latency);
176ACCESS_ATTR(write_bandwidth);
177ACCESS_ATTR(write_latency);
178
179static 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 */
193void node_set_perf_attrs(unsigned int nid, struct access_coordinate *coord,
194 enum access_coordinate_class access)
195{
196 struct node_access_nodes *c;
197 struct node *node;
198 int i;
199
200 if (WARN_ON_ONCE(!node_online(nid)))
201 return;
202
203 node = node_devices[nid];
204 c = node_init_node_access(node, access);
205 if (!c)
206 return;
207
208 c->coord = *coord;
209 for (i = 0; access_attrs[i] != NULL; i++) {
210 if (sysfs_add_file_to_group(kobj: &c->dev.kobj, attr: access_attrs[i],
211 group: "initiators")) {
212 pr_info("failed to add performance attribute to node %d\n",
213 nid);
214 break;
215 }
216 }
217}
218EXPORT_SYMBOL_GPL(node_set_perf_attrs);
219
220/**
221 * struct node_cache_info - Internal tracking for memory node caches
222 * @dev: Device represeting the cache level
223 * @node: List element for tracking in the node
224 * @cache_attrs:Attributes for this cache level
225 */
226struct node_cache_info {
227 struct device dev;
228 struct list_head node;
229 struct node_cache_attrs cache_attrs;
230};
231#define to_cache_info(device) container_of(device, struct node_cache_info, dev)
232
233#define CACHE_ATTR(name, fmt) \
234static ssize_t name##_show(struct device *dev, \
235 struct device_attribute *attr, \
236 char *buf) \
237{ \
238 return sysfs_emit(buf, fmt "\n", \
239 to_cache_info(dev)->cache_attrs.name); \
240} \
241static DEVICE_ATTR_RO(name);
242
243CACHE_ATTR(size, "%llu")
244CACHE_ATTR(line_size, "%u")
245CACHE_ATTR(indexing, "%u")
246CACHE_ATTR(write_policy, "%u")
247
248static struct attribute *cache_attrs[] = {
249 &dev_attr_indexing.attr,
250 &dev_attr_size.attr,
251 &dev_attr_line_size.attr,
252 &dev_attr_write_policy.attr,
253 NULL,
254};
255ATTRIBUTE_GROUPS(cache);
256
257static void node_cache_release(struct device *dev)
258{
259 kfree(objp: dev);
260}
261
262static void node_cacheinfo_release(struct device *dev)
263{
264 struct node_cache_info *info = to_cache_info(dev);
265 kfree(objp: info);
266}
267
268static void node_init_cache_dev(struct node *node)
269{
270 struct device *dev;
271
272 dev = kzalloc(size: sizeof(*dev), GFP_KERNEL);
273 if (!dev)
274 return;
275
276 device_initialize(dev);
277 dev->parent = &node->dev;
278 dev->release = node_cache_release;
279 if (dev_set_name(dev, name: "memory_side_cache"))
280 goto put_device;
281
282 if (device_add(dev))
283 goto put_device;
284
285 pm_runtime_no_callbacks(dev);
286 node->cache_dev = dev;
287 return;
288put_device:
289 put_device(dev);
290}
291
292/**
293 * node_add_cache() - add cache attribute to a memory node
294 * @nid: Node identifier that has new cache attributes
295 * @cache_attrs: Attributes for the cache being added
296 */
297void node_add_cache(unsigned int nid, struct node_cache_attrs *cache_attrs)
298{
299 struct node_cache_info *info;
300 struct device *dev;
301 struct node *node;
302
303 if (!node_online(nid) || !node_devices[nid])
304 return;
305
306 node = node_devices[nid];
307 list_for_each_entry(info, &node->cache_attrs, node) {
308 if (info->cache_attrs.level == cache_attrs->level) {
309 dev_warn(&node->dev,
310 "attempt to add duplicate cache level:%d\n",
311 cache_attrs->level);
312 return;
313 }
314 }
315
316 if (!node->cache_dev)
317 node_init_cache_dev(node);
318 if (!node->cache_dev)
319 return;
320
321 info = kzalloc(size: sizeof(*info), GFP_KERNEL);
322 if (!info)
323 return;
324
325 dev = &info->dev;
326 device_initialize(dev);
327 dev->parent = node->cache_dev;
328 dev->release = node_cacheinfo_release;
329 dev->groups = cache_groups;
330 if (dev_set_name(dev, name: "index%d", cache_attrs->level))
331 goto put_device;
332
333 info->cache_attrs = *cache_attrs;
334 if (device_add(dev)) {
335 dev_warn(&node->dev, "failed to add cache level:%d\n",
336 cache_attrs->level);
337 goto put_device;
338 }
339 pm_runtime_no_callbacks(dev);
340 list_add_tail(new: &info->node, head: &node->cache_attrs);
341 return;
342put_device:
343 put_device(dev);
344}
345
346static void node_remove_caches(struct node *node)
347{
348 struct node_cache_info *info, *next;
349
350 if (!node->cache_dev)
351 return;
352
353 list_for_each_entry_safe(info, next, &node->cache_attrs, node) {
354 list_del(entry: &info->node);
355 device_unregister(dev: &info->dev);
356 }
357 device_unregister(dev: node->cache_dev);
358}
359
360static void node_init_caches(unsigned int nid)
361{
362 INIT_LIST_HEAD(list: &node_devices[nid]->cache_attrs);
363}
364#else
365static void node_init_caches(unsigned int nid) { }
366static void node_remove_caches(struct node *node) { }
367#endif
368
369#define K(x) ((x) << (PAGE_SHIFT - 10))
370static ssize_t node_read_meminfo(struct device *dev,
371 struct device_attribute *attr, char *buf)
372{
373 int len = 0;
374 int nid = dev->id;
375 struct pglist_data *pgdat = NODE_DATA(nid);
376 struct sysinfo i;
377 unsigned long sreclaimable, sunreclaimable;
378 unsigned long swapcached = 0;
379
380 si_meminfo_node(val: &i, nid);
381 sreclaimable = node_page_state_pages(pgdat, item: NR_SLAB_RECLAIMABLE_B);
382 sunreclaimable = node_page_state_pages(pgdat, item: NR_SLAB_UNRECLAIMABLE_B);
383#ifdef CONFIG_SWAP
384 swapcached = node_page_state_pages(pgdat, item: NR_SWAPCACHE);
385#endif
386 len = sysfs_emit_at(buf, at: len,
387 fmt: "Node %d MemTotal: %8lu kB\n"
388 "Node %d MemFree: %8lu kB\n"
389 "Node %d MemUsed: %8lu kB\n"
390 "Node %d SwapCached: %8lu kB\n"
391 "Node %d Active: %8lu kB\n"
392 "Node %d Inactive: %8lu kB\n"
393 "Node %d Active(anon): %8lu kB\n"
394 "Node %d Inactive(anon): %8lu kB\n"
395 "Node %d Active(file): %8lu kB\n"
396 "Node %d Inactive(file): %8lu kB\n"
397 "Node %d Unevictable: %8lu kB\n"
398 "Node %d Mlocked: %8lu kB\n",
399 nid, K(i.totalram),
400 nid, K(i.freeram),
401 nid, K(i.totalram - i.freeram),
402 nid, K(swapcached),
403 nid, K(node_page_state(pgdat, NR_ACTIVE_ANON) +
404 node_page_state(pgdat, NR_ACTIVE_FILE)),
405 nid, K(node_page_state(pgdat, NR_INACTIVE_ANON) +
406 node_page_state(pgdat, NR_INACTIVE_FILE)),
407 nid, K(node_page_state(pgdat, NR_ACTIVE_ANON)),
408 nid, K(node_page_state(pgdat, NR_INACTIVE_ANON)),
409 nid, K(node_page_state(pgdat, NR_ACTIVE_FILE)),
410 nid, K(node_page_state(pgdat, NR_INACTIVE_FILE)),
411 nid, K(node_page_state(pgdat, NR_UNEVICTABLE)),
412 nid, K(sum_zone_node_page_state(nid, NR_MLOCK)));
413
414#ifdef CONFIG_HIGHMEM
415 len += sysfs_emit_at(buf, len,
416 "Node %d HighTotal: %8lu kB\n"
417 "Node %d HighFree: %8lu kB\n"
418 "Node %d LowTotal: %8lu kB\n"
419 "Node %d LowFree: %8lu kB\n",
420 nid, K(i.totalhigh),
421 nid, K(i.freehigh),
422 nid, K(i.totalram - i.totalhigh),
423 nid, K(i.freeram - i.freehigh));
424#endif
425 len += sysfs_emit_at(buf, at: len,
426 fmt: "Node %d Dirty: %8lu kB\n"
427 "Node %d Writeback: %8lu kB\n"
428 "Node %d FilePages: %8lu kB\n"
429 "Node %d Mapped: %8lu kB\n"
430 "Node %d AnonPages: %8lu kB\n"
431 "Node %d Shmem: %8lu kB\n"
432 "Node %d KernelStack: %8lu kB\n"
433#ifdef CONFIG_SHADOW_CALL_STACK
434 "Node %d ShadowCallStack:%8lu kB\n"
435#endif
436 "Node %d PageTables: %8lu kB\n"
437 "Node %d SecPageTables: %8lu kB\n"
438 "Node %d NFS_Unstable: %8lu kB\n"
439 "Node %d Bounce: %8lu kB\n"
440 "Node %d WritebackTmp: %8lu kB\n"
441 "Node %d KReclaimable: %8lu kB\n"
442 "Node %d Slab: %8lu kB\n"
443 "Node %d SReclaimable: %8lu kB\n"
444 "Node %d SUnreclaim: %8lu kB\n"
445#ifdef CONFIG_TRANSPARENT_HUGEPAGE
446 "Node %d AnonHugePages: %8lu kB\n"
447 "Node %d ShmemHugePages: %8lu kB\n"
448 "Node %d ShmemPmdMapped: %8lu kB\n"
449 "Node %d FileHugePages: %8lu kB\n"
450 "Node %d FilePmdMapped: %8lu kB\n"
451#endif
452#ifdef CONFIG_UNACCEPTED_MEMORY
453 "Node %d Unaccepted: %8lu kB\n"
454#endif
455 ,
456 nid, K(node_page_state(pgdat, NR_FILE_DIRTY)),
457 nid, K(node_page_state(pgdat, NR_WRITEBACK)),
458 nid, K(node_page_state(pgdat, NR_FILE_PAGES)),
459 nid, K(node_page_state(pgdat, NR_FILE_MAPPED)),
460 nid, K(node_page_state(pgdat, NR_ANON_MAPPED)),
461 nid, K(i.sharedram),
462 nid, node_page_state(pgdat, item: NR_KERNEL_STACK_KB),
463#ifdef CONFIG_SHADOW_CALL_STACK
464 nid, node_page_state(pgdat, NR_KERNEL_SCS_KB),
465#endif
466 nid, K(node_page_state(pgdat, NR_PAGETABLE)),
467 nid, K(node_page_state(pgdat, NR_SECONDARY_PAGETABLE)),
468 nid, 0UL,
469 nid, K(sum_zone_node_page_state(nid, NR_BOUNCE)),
470 nid, K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
471 nid, K(sreclaimable +
472 node_page_state(pgdat, NR_KERNEL_MISC_RECLAIMABLE)),
473 nid, K(sreclaimable + sunreclaimable),
474 nid, K(sreclaimable),
475 nid, K(sunreclaimable)
476#ifdef CONFIG_TRANSPARENT_HUGEPAGE
477 ,
478 nid, K(node_page_state(pgdat, NR_ANON_THPS)),
479 nid, K(node_page_state(pgdat, NR_SHMEM_THPS)),
480 nid, K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED)),
481 nid, K(node_page_state(pgdat, NR_FILE_THPS)),
482 nid, K(node_page_state(pgdat, NR_FILE_PMDMAPPED))
483#endif
484#ifdef CONFIG_UNACCEPTED_MEMORY
485 ,
486 nid, K(sum_zone_node_page_state(nid, NR_UNACCEPTED))
487#endif
488 );
489 len += hugetlb_report_node_meminfo(buf, len, nid);
490 return len;
491}
492
493#undef K
494static DEVICE_ATTR(meminfo, 0444, node_read_meminfo, NULL);
495
496static ssize_t node_read_numastat(struct device *dev,
497 struct device_attribute *attr, char *buf)
498{
499 fold_vm_numa_events();
500 return sysfs_emit(buf,
501 fmt: "numa_hit %lu\n"
502 "numa_miss %lu\n"
503 "numa_foreign %lu\n"
504 "interleave_hit %lu\n"
505 "local_node %lu\n"
506 "other_node %lu\n",
507 sum_zone_numa_event_state(node: dev->id, item: NUMA_HIT),
508 sum_zone_numa_event_state(node: dev->id, item: NUMA_MISS),
509 sum_zone_numa_event_state(node: dev->id, item: NUMA_FOREIGN),
510 sum_zone_numa_event_state(node: dev->id, item: NUMA_INTERLEAVE_HIT),
511 sum_zone_numa_event_state(node: dev->id, item: NUMA_LOCAL),
512 sum_zone_numa_event_state(node: dev->id, item: NUMA_OTHER));
513}
514static DEVICE_ATTR(numastat, 0444, node_read_numastat, NULL);
515
516static ssize_t node_read_vmstat(struct device *dev,
517 struct device_attribute *attr, char *buf)
518{
519 int nid = dev->id;
520 struct pglist_data *pgdat = NODE_DATA(nid);
521 int i;
522 int len = 0;
523
524 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
525 len += sysfs_emit_at(buf, at: len, fmt: "%s %lu\n",
526 zone_stat_name(item: i),
527 sum_zone_node_page_state(node: nid, item: i));
528
529#ifdef CONFIG_NUMA
530 fold_vm_numa_events();
531 for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++)
532 len += sysfs_emit_at(buf, at: len, fmt: "%s %lu\n",
533 numa_stat_name(item: i),
534 sum_zone_numa_event_state(node: nid, item: i));
535
536#endif
537 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
538 unsigned long pages = node_page_state_pages(pgdat, item: i);
539
540 if (vmstat_item_print_in_thp(item: i))
541 pages /= HPAGE_PMD_NR;
542 len += sysfs_emit_at(buf, at: len, fmt: "%s %lu\n", node_stat_name(item: i),
543 pages);
544 }
545
546 return len;
547}
548static DEVICE_ATTR(vmstat, 0444, node_read_vmstat, NULL);
549
550static ssize_t node_read_distance(struct device *dev,
551 struct device_attribute *attr, char *buf)
552{
553 int nid = dev->id;
554 int len = 0;
555 int i;
556
557 /*
558 * buf is currently PAGE_SIZE in length and each node needs 4 chars
559 * at the most (distance + space or newline).
560 */
561 BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE);
562
563 for_each_online_node(i) {
564 len += sysfs_emit_at(buf, at: len, fmt: "%s%d",
565 i ? " " : "", node_distance(nid, i));
566 }
567
568 len += sysfs_emit_at(buf, at: len, fmt: "\n");
569 return len;
570}
571static DEVICE_ATTR(distance, 0444, node_read_distance, NULL);
572
573static struct attribute *node_dev_attrs[] = {
574 &dev_attr_meminfo.attr,
575 &dev_attr_numastat.attr,
576 &dev_attr_distance.attr,
577 &dev_attr_vmstat.attr,
578 NULL
579};
580
581static struct bin_attribute *node_dev_bin_attrs[] = {
582 &bin_attr_cpumap,
583 &bin_attr_cpulist,
584 NULL
585};
586
587static const struct attribute_group node_dev_group = {
588 .attrs = node_dev_attrs,
589 .bin_attrs = node_dev_bin_attrs
590};
591
592static const struct attribute_group *node_dev_groups[] = {
593 &node_dev_group,
594#ifdef CONFIG_HAVE_ARCH_NODE_DEV_GROUP
595 &arch_node_dev_group,
596#endif
597#ifdef CONFIG_MEMORY_FAILURE
598 &memory_failure_attr_group,
599#endif
600 NULL
601};
602
603static void node_device_release(struct device *dev)
604{
605 kfree(to_node(dev));
606}
607
608/*
609 * register_node - Setup a sysfs device for a node.
610 * @num - Node number to use when creating the device.
611 *
612 * Initialize and register the node device.
613 */
614static int register_node(struct node *node, int num)
615{
616 int error;
617
618 node->dev.id = num;
619 node->dev.bus = &node_subsys;
620 node->dev.release = node_device_release;
621 node->dev.groups = node_dev_groups;
622 error = device_register(dev: &node->dev);
623
624 if (error) {
625 put_device(dev: &node->dev);
626 } else {
627 hugetlb_register_node(node);
628 compaction_register_node(node);
629 }
630
631 return error;
632}
633
634/**
635 * unregister_node - unregister a node device
636 * @node: node going away
637 *
638 * Unregisters a node device @node. All the devices on the node must be
639 * unregistered before calling this function.
640 */
641void unregister_node(struct node *node)
642{
643 hugetlb_unregister_node(node);
644 compaction_unregister_node(node);
645 node_remove_accesses(node);
646 node_remove_caches(node);
647 device_unregister(dev: &node->dev);
648}
649
650struct node *node_devices[MAX_NUMNODES];
651
652/*
653 * register cpu under node
654 */
655int register_cpu_under_node(unsigned int cpu, unsigned int nid)
656{
657 int ret;
658 struct device *obj;
659
660 if (!node_online(nid))
661 return 0;
662
663 obj = get_cpu_device(cpu);
664 if (!obj)
665 return 0;
666
667 ret = sysfs_create_link(kobj: &node_devices[nid]->dev.kobj,
668 target: &obj->kobj,
669 name: kobject_name(kobj: &obj->kobj));
670 if (ret)
671 return ret;
672
673 return sysfs_create_link(kobj: &obj->kobj,
674 target: &node_devices[nid]->dev.kobj,
675 name: kobject_name(kobj: &node_devices[nid]->dev.kobj));
676}
677
678/**
679 * register_memory_node_under_compute_node - link memory node to its compute
680 * node for a given access class.
681 * @mem_nid: Memory node number
682 * @cpu_nid: Cpu node number
683 * @access: Access class to register
684 *
685 * Description:
686 * For use with platforms that may have separate memory and compute nodes.
687 * This function will export node relationships linking which memory
688 * initiator nodes can access memory targets at a given ranked access
689 * class.
690 */
691int register_memory_node_under_compute_node(unsigned int mem_nid,
692 unsigned int cpu_nid,
693 enum access_coordinate_class access)
694{
695 struct node *init_node, *targ_node;
696 struct node_access_nodes *initiator, *target;
697 int ret;
698
699 if (!node_online(cpu_nid) || !node_online(mem_nid))
700 return -ENODEV;
701
702 init_node = node_devices[cpu_nid];
703 targ_node = node_devices[mem_nid];
704 initiator = node_init_node_access(node: init_node, access);
705 target = node_init_node_access(node: targ_node, access);
706 if (!initiator || !target)
707 return -ENOMEM;
708
709 ret = sysfs_add_link_to_group(kobj: &initiator->dev.kobj, group_name: "targets",
710 target: &targ_node->dev.kobj,
711 link_name: dev_name(dev: &targ_node->dev));
712 if (ret)
713 return ret;
714
715 ret = sysfs_add_link_to_group(kobj: &target->dev.kobj, group_name: "initiators",
716 target: &init_node->dev.kobj,
717 link_name: dev_name(dev: &init_node->dev));
718 if (ret)
719 goto err;
720
721 return 0;
722 err:
723 sysfs_remove_link_from_group(kobj: &initiator->dev.kobj, group_name: "targets",
724 link_name: dev_name(dev: &targ_node->dev));
725 return ret;
726}
727
728int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
729{
730 struct device *obj;
731
732 if (!node_online(nid))
733 return 0;
734
735 obj = get_cpu_device(cpu);
736 if (!obj)
737 return 0;
738
739 sysfs_remove_link(kobj: &node_devices[nid]->dev.kobj,
740 name: kobject_name(kobj: &obj->kobj));
741 sysfs_remove_link(kobj: &obj->kobj,
742 name: kobject_name(kobj: &node_devices[nid]->dev.kobj));
743
744 return 0;
745}
746
747#ifdef CONFIG_MEMORY_HOTPLUG
748static int __ref get_nid_for_pfn(unsigned long pfn)
749{
750#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
751 if (system_state < SYSTEM_RUNNING)
752 return early_pfn_to_nid(pfn);
753#endif
754 return pfn_to_nid(pfn);
755}
756
757static void do_register_memory_block_under_node(int nid,
758 struct memory_block *mem_blk,
759 enum meminit_context context)
760{
761 int ret;
762
763 memory_block_add_nid(mem: mem_blk, nid, context);
764
765 ret = sysfs_create_link_nowarn(kobj: &node_devices[nid]->dev.kobj,
766 target: &mem_blk->dev.kobj,
767 name: kobject_name(kobj: &mem_blk->dev.kobj));
768 if (ret && ret != -EEXIST)
769 dev_err_ratelimited(&node_devices[nid]->dev,
770 "can't create link to %s in sysfs (%d)\n",
771 kobject_name(&mem_blk->dev.kobj), ret);
772
773 ret = sysfs_create_link_nowarn(kobj: &mem_blk->dev.kobj,
774 target: &node_devices[nid]->dev.kobj,
775 name: kobject_name(kobj: &node_devices[nid]->dev.kobj));
776 if (ret && ret != -EEXIST)
777 dev_err_ratelimited(&mem_blk->dev,
778 "can't create link to %s in sysfs (%d)\n",
779 kobject_name(&node_devices[nid]->dev.kobj),
780 ret);
781}
782
783/* register memory section under specified node if it spans that node */
784static int register_mem_block_under_node_early(struct memory_block *mem_blk,
785 void *arg)
786{
787 unsigned long memory_block_pfns = memory_block_size_bytes() / PAGE_SIZE;
788 unsigned long start_pfn = section_nr_to_pfn(sec: mem_blk->start_section_nr);
789 unsigned long end_pfn = start_pfn + memory_block_pfns - 1;
790 int nid = *(int *)arg;
791 unsigned long pfn;
792
793 for (pfn = start_pfn; pfn <= end_pfn; pfn++) {
794 int page_nid;
795
796 /*
797 * memory block could have several absent sections from start.
798 * skip pfn range from absent section
799 */
800 if (!pfn_in_present_section(pfn)) {
801 pfn = round_down(pfn + PAGES_PER_SECTION,
802 PAGES_PER_SECTION) - 1;
803 continue;
804 }
805
806 /*
807 * We need to check if page belongs to nid only at the boot
808 * case because node's ranges can be interleaved.
809 */
810 page_nid = get_nid_for_pfn(pfn);
811 if (page_nid < 0)
812 continue;
813 if (page_nid != nid)
814 continue;
815
816 do_register_memory_block_under_node(nid, mem_blk, context: MEMINIT_EARLY);
817 return 0;
818 }
819 /* mem section does not span the specified node */
820 return 0;
821}
822
823/*
824 * During hotplug we know that all pages in the memory block belong to the same
825 * node.
826 */
827static int register_mem_block_under_node_hotplug(struct memory_block *mem_blk,
828 void *arg)
829{
830 int nid = *(int *)arg;
831
832 do_register_memory_block_under_node(nid, mem_blk, context: MEMINIT_HOTPLUG);
833 return 0;
834}
835
836/*
837 * Unregister a memory block device under the node it spans. Memory blocks
838 * with multiple nodes cannot be offlined and therefore also never be removed.
839 */
840void unregister_memory_block_under_nodes(struct memory_block *mem_blk)
841{
842 if (mem_blk->nid == NUMA_NO_NODE)
843 return;
844
845 sysfs_remove_link(kobj: &node_devices[mem_blk->nid]->dev.kobj,
846 name: kobject_name(kobj: &mem_blk->dev.kobj));
847 sysfs_remove_link(kobj: &mem_blk->dev.kobj,
848 name: kobject_name(kobj: &node_devices[mem_blk->nid]->dev.kobj));
849}
850
851void register_memory_blocks_under_node(int nid, unsigned long start_pfn,
852 unsigned long end_pfn,
853 enum meminit_context context)
854{
855 walk_memory_blocks_func_t func;
856
857 if (context == MEMINIT_HOTPLUG)
858 func = register_mem_block_under_node_hotplug;
859 else
860 func = register_mem_block_under_node_early;
861
862 walk_memory_blocks(PFN_PHYS(start_pfn), PFN_PHYS(end_pfn - start_pfn),
863 arg: (void *)&nid, func);
864 return;
865}
866#endif /* CONFIG_MEMORY_HOTPLUG */
867
868int __register_one_node(int nid)
869{
870 int error;
871 int cpu;
872 struct node *node;
873
874 node = kzalloc(size: sizeof(struct node), GFP_KERNEL);
875 if (!node)
876 return -ENOMEM;
877
878 INIT_LIST_HEAD(list: &node->access_list);
879 node_devices[nid] = node;
880
881 error = register_node(node: node_devices[nid], num: nid);
882
883 /* link cpu under this node */
884 for_each_present_cpu(cpu) {
885 if (cpu_to_node(cpu) == nid)
886 register_cpu_under_node(cpu, nid);
887 }
888
889 node_init_caches(nid);
890
891 return error;
892}
893
894void unregister_one_node(int nid)
895{
896 if (!node_devices[nid])
897 return;
898
899 unregister_node(node: node_devices[nid]);
900 node_devices[nid] = NULL;
901}
902
903/*
904 * node states attributes
905 */
906
907struct node_attr {
908 struct device_attribute attr;
909 enum node_states state;
910};
911
912static ssize_t show_node_state(struct device *dev,
913 struct device_attribute *attr, char *buf)
914{
915 struct node_attr *na = container_of(attr, struct node_attr, attr);
916
917 return sysfs_emit(buf, fmt: "%*pbl\n",
918 nodemask_pr_args(&node_states[na->state]));
919}
920
921#define _NODE_ATTR(name, state) \
922 { __ATTR(name, 0444, show_node_state, NULL), state }
923
924static struct node_attr node_state_attr[] = {
925 [N_POSSIBLE] = _NODE_ATTR(possible, N_POSSIBLE),
926 [N_ONLINE] = _NODE_ATTR(online, N_ONLINE),
927 [N_NORMAL_MEMORY] = _NODE_ATTR(has_normal_memory, N_NORMAL_MEMORY),
928#ifdef CONFIG_HIGHMEM
929 [N_HIGH_MEMORY] = _NODE_ATTR(has_high_memory, N_HIGH_MEMORY),
930#endif
931 [N_MEMORY] = _NODE_ATTR(has_memory, N_MEMORY),
932 [N_CPU] = _NODE_ATTR(has_cpu, N_CPU),
933 [N_GENERIC_INITIATOR] = _NODE_ATTR(has_generic_initiator,
934 N_GENERIC_INITIATOR),
935};
936
937static struct attribute *node_state_attrs[] = {
938 &node_state_attr[N_POSSIBLE].attr.attr,
939 &node_state_attr[N_ONLINE].attr.attr,
940 &node_state_attr[N_NORMAL_MEMORY].attr.attr,
941#ifdef CONFIG_HIGHMEM
942 &node_state_attr[N_HIGH_MEMORY].attr.attr,
943#endif
944 &node_state_attr[N_MEMORY].attr.attr,
945 &node_state_attr[N_CPU].attr.attr,
946 &node_state_attr[N_GENERIC_INITIATOR].attr.attr,
947 NULL
948};
949
950static const struct attribute_group memory_root_attr_group = {
951 .attrs = node_state_attrs,
952};
953
954static const struct attribute_group *cpu_root_attr_groups[] = {
955 &memory_root_attr_group,
956 NULL,
957};
958
959void __init node_dev_init(void)
960{
961 int ret, i;
962
963 BUILD_BUG_ON(ARRAY_SIZE(node_state_attr) != NR_NODE_STATES);
964 BUILD_BUG_ON(ARRAY_SIZE(node_state_attrs)-1 != NR_NODE_STATES);
965
966 ret = subsys_system_register(subsys: &node_subsys, groups: cpu_root_attr_groups);
967 if (ret)
968 panic(fmt: "%s() failed to register subsystem: %d\n", __func__, ret);
969
970 /*
971 * Create all node devices, which will properly link the node
972 * to applicable memory block devices and already created cpu devices.
973 */
974 for_each_online_node(i) {
975 ret = register_one_node(nid: i);
976 if (ret)
977 panic(fmt: "%s() failed to add node: %d\n", __func__, ret);
978 }
979}
980

source code of linux/drivers/base/node.c