ad43185ec15adebc4d48d80ffb58275b18827da3
[linux-2.6.git] / drivers / base / node.c
1 /*
2  * drivers/base/node.c - basic Node class support
3  */
4
5 #include <linux/sysdev.h>
6 #include <linux/module.h>
7 #include <linux/init.h>
8 #include <linux/mm.h>
9 #include <linux/memory.h>
10 #include <linux/node.h>
11 #include <linux/hugetlb.h>
12 #include <linux/cpumask.h>
13 #include <linux/topology.h>
14 #include <linux/nodemask.h>
15 #include <linux/cpu.h>
16 #include <linux/device.h>
17 #include <linux/swap.h>
18
19 static struct sysdev_class_attribute *node_state_attrs[];
20
21 static struct sysdev_class node_class = {
22         .name = "node",
23         .attrs = node_state_attrs,
24 };
25
26
27 static ssize_t node_read_cpumap(struct sys_device *dev, int type, char *buf)
28 {
29         struct node *node_dev = to_node(dev);
30         const struct cpumask *mask = cpumask_of_node(node_dev->sysdev.id);
31         int len;
32
33         /* 2008/04/07: buf currently PAGE_SIZE, need 9 chars per 32 bits. */
34         BUILD_BUG_ON((NR_CPUS/32 * 9) > (PAGE_SIZE-1));
35
36         len = type?
37                 cpulist_scnprintf(buf, PAGE_SIZE-2, mask) :
38                 cpumask_scnprintf(buf, PAGE_SIZE-2, mask);
39         buf[len++] = '\n';
40         buf[len] = '\0';
41         return len;
42 }
43
44 static inline ssize_t node_read_cpumask(struct sys_device *dev,
45                                 struct sysdev_attribute *attr, char *buf)
46 {
47         return node_read_cpumap(dev, 0, buf);
48 }
49 static inline ssize_t node_read_cpulist(struct sys_device *dev,
50                                 struct sysdev_attribute *attr, char *buf)
51 {
52         return node_read_cpumap(dev, 1, buf);
53 }
54
55 static SYSDEV_ATTR(cpumap,  S_IRUGO, node_read_cpumask, NULL);
56 static SYSDEV_ATTR(cpulist, S_IRUGO, node_read_cpulist, NULL);
57
58 #define K(x) ((x) << (PAGE_SHIFT - 10))
59 static ssize_t node_read_meminfo(struct sys_device * dev,
60                         struct sysdev_attribute *attr, char * buf)
61 {
62         int n;
63         int nid = dev->id;
64         struct sysinfo i;
65
66         si_meminfo_node(&i, nid);
67
68         n = sprintf(buf, "\n"
69                        "Node %d MemTotal:       %8lu kB\n"
70                        "Node %d MemFree:        %8lu kB\n"
71                        "Node %d MemUsed:        %8lu kB\n"
72                        "Node %d Active:         %8lu kB\n"
73                        "Node %d Inactive:       %8lu kB\n"
74                        "Node %d Active(anon):   %8lu kB\n"
75                        "Node %d Inactive(anon): %8lu kB\n"
76                        "Node %d Active(file):   %8lu kB\n"
77                        "Node %d Inactive(file): %8lu kB\n"
78                        "Node %d Unevictable:    %8lu kB\n"
79                        "Node %d Mlocked:        %8lu kB\n"
80 #ifdef CONFIG_HIGHMEM
81                        "Node %d HighTotal:      %8lu kB\n"
82                        "Node %d HighFree:       %8lu kB\n"
83                        "Node %d LowTotal:       %8lu kB\n"
84                        "Node %d LowFree:        %8lu kB\n"
85 #endif
86                        "Node %d Dirty:          %8lu kB\n"
87                        "Node %d Writeback:      %8lu kB\n"
88                        "Node %d FilePages:      %8lu kB\n"
89                        "Node %d Mapped:         %8lu kB\n"
90                        "Node %d AnonPages:      %8lu kB\n"
91                        "Node %d Shmem:          %8lu kB\n"
92                        "Node %d KernelStack:    %8lu kB\n"
93                        "Node %d PageTables:     %8lu kB\n"
94                        "Node %d NFS_Unstable:   %8lu kB\n"
95                        "Node %d Bounce:         %8lu kB\n"
96                        "Node %d WritebackTmp:   %8lu kB\n"
97                        "Node %d Slab:           %8lu kB\n"
98                        "Node %d SReclaimable:   %8lu kB\n"
99                        "Node %d SUnreclaim:     %8lu kB\n",
100                        nid, K(i.totalram),
101                        nid, K(i.freeram),
102                        nid, K(i.totalram - i.freeram),
103                        nid, K(node_page_state(nid, NR_ACTIVE_ANON) +
104                                 node_page_state(nid, NR_ACTIVE_FILE)),
105                        nid, K(node_page_state(nid, NR_INACTIVE_ANON) +
106                                 node_page_state(nid, NR_INACTIVE_FILE)),
107                        nid, K(node_page_state(nid, NR_ACTIVE_ANON)),
108                        nid, K(node_page_state(nid, NR_INACTIVE_ANON)),
109                        nid, K(node_page_state(nid, NR_ACTIVE_FILE)),
110                        nid, K(node_page_state(nid, NR_INACTIVE_FILE)),
111                        nid, K(node_page_state(nid, NR_UNEVICTABLE)),
112                        nid, K(node_page_state(nid, NR_MLOCK)),
113 #ifdef CONFIG_HIGHMEM
114                        nid, K(i.totalhigh),
115                        nid, K(i.freehigh),
116                        nid, K(i.totalram - i.totalhigh),
117                        nid, K(i.freeram - i.freehigh),
118 #endif
119                        nid, K(node_page_state(nid, NR_FILE_DIRTY)),
120                        nid, K(node_page_state(nid, NR_WRITEBACK)),
121                        nid, K(node_page_state(nid, NR_FILE_PAGES)),
122                        nid, K(node_page_state(nid, NR_FILE_MAPPED)),
123                        nid, K(node_page_state(nid, NR_ANON_PAGES)),
124                        nid, K(node_page_state(nid, NR_SHMEM)),
125                        nid, node_page_state(nid, NR_KERNEL_STACK) *
126                                 THREAD_SIZE / 1024,
127                        nid, K(node_page_state(nid, NR_PAGETABLE)),
128                        nid, K(node_page_state(nid, NR_UNSTABLE_NFS)),
129                        nid, K(node_page_state(nid, NR_BOUNCE)),
130                        nid, K(node_page_state(nid, NR_WRITEBACK_TEMP)),
131                        nid, K(node_page_state(nid, NR_SLAB_RECLAIMABLE) +
132                                 node_page_state(nid, NR_SLAB_UNRECLAIMABLE)),
133                        nid, K(node_page_state(nid, NR_SLAB_RECLAIMABLE)),
134                        nid, K(node_page_state(nid, NR_SLAB_UNRECLAIMABLE)));
135         n += hugetlb_report_node_meminfo(nid, buf + n);
136         return n;
137 }
138
139 #undef K
140 static SYSDEV_ATTR(meminfo, S_IRUGO, node_read_meminfo, NULL);
141
142 static ssize_t node_read_numastat(struct sys_device * dev,
143                                 struct sysdev_attribute *attr, char * buf)
144 {
145         return sprintf(buf,
146                        "numa_hit %lu\n"
147                        "numa_miss %lu\n"
148                        "numa_foreign %lu\n"
149                        "interleave_hit %lu\n"
150                        "local_node %lu\n"
151                        "other_node %lu\n",
152                        node_page_state(dev->id, NUMA_HIT),
153                        node_page_state(dev->id, NUMA_MISS),
154                        node_page_state(dev->id, NUMA_FOREIGN),
155                        node_page_state(dev->id, NUMA_INTERLEAVE_HIT),
156                        node_page_state(dev->id, NUMA_LOCAL),
157                        node_page_state(dev->id, NUMA_OTHER));
158 }
159 static SYSDEV_ATTR(numastat, S_IRUGO, node_read_numastat, NULL);
160
161 static ssize_t node_read_distance(struct sys_device * dev,
162                         struct sysdev_attribute *attr, char * buf)
163 {
164         int nid = dev->id;
165         int len = 0;
166         int i;
167
168         /* buf currently PAGE_SIZE, need ~4 chars per node */
169         BUILD_BUG_ON(MAX_NUMNODES*4 > PAGE_SIZE/2);
170
171         for_each_online_node(i)
172                 len += sprintf(buf + len, "%s%d", i ? " " : "", node_distance(nid, i));
173
174         len += sprintf(buf + len, "\n");
175         return len;
176 }
177 static SYSDEV_ATTR(distance, S_IRUGO, node_read_distance, NULL);
178
179 #ifdef CONFIG_HUGETLBFS
180 /*
181  * hugetlbfs per node attributes registration interface:
182  * When/if hugetlb[fs] subsystem initializes [sometime after this module],
183  * it will register its per node attributes for all online nodes with
184  * memory.  It will also call register_hugetlbfs_with_node(), below, to
185  * register its attribute registration functions with this node driver.
186  * Once these hooks have been initialized, the node driver will call into
187  * the hugetlb module to [un]register attributes for hot-plugged nodes.
188  */
189 static node_registration_func_t __hugetlb_register_node;
190 static node_registration_func_t __hugetlb_unregister_node;
191
192 static inline bool hugetlb_register_node(struct node *node)
193 {
194         if (__hugetlb_register_node &&
195                         node_state(node->sysdev.id, N_HIGH_MEMORY)) {
196                 __hugetlb_register_node(node);
197                 return true;
198         }
199         return false;
200 }
201
202 static inline void hugetlb_unregister_node(struct node *node)
203 {
204         if (__hugetlb_unregister_node)
205                 __hugetlb_unregister_node(node);
206 }
207
208 void register_hugetlbfs_with_node(node_registration_func_t doregister,
209                                   node_registration_func_t unregister)
210 {
211         __hugetlb_register_node   = doregister;
212         __hugetlb_unregister_node = unregister;
213 }
214 #else
215 static inline void hugetlb_register_node(struct node *node) {}
216
217 static inline void hugetlb_unregister_node(struct node *node) {}
218 #endif
219
220
221 /*
222  * register_node - Setup a sysfs device for a node.
223  * @num - Node number to use when creating the device.
224  *
225  * Initialize and register the node device.
226  */
227 int register_node(struct node *node, int num, struct node *parent)
228 {
229         int error;
230
231         node->sysdev.id = num;
232         node->sysdev.cls = &node_class;
233         error = sysdev_register(&node->sysdev);
234
235         if (!error){
236                 sysdev_create_file(&node->sysdev, &attr_cpumap);
237                 sysdev_create_file(&node->sysdev, &attr_cpulist);
238                 sysdev_create_file(&node->sysdev, &attr_meminfo);
239                 sysdev_create_file(&node->sysdev, &attr_numastat);
240                 sysdev_create_file(&node->sysdev, &attr_distance);
241
242                 scan_unevictable_register_node(node);
243
244                 hugetlb_register_node(node);
245         }
246         return error;
247 }
248
249 /**
250  * unregister_node - unregister a node device
251  * @node: node going away
252  *
253  * Unregisters a node device @node.  All the devices on the node must be
254  * unregistered before calling this function.
255  */
256 void unregister_node(struct node *node)
257 {
258         sysdev_remove_file(&node->sysdev, &attr_cpumap);
259         sysdev_remove_file(&node->sysdev, &attr_cpulist);
260         sysdev_remove_file(&node->sysdev, &attr_meminfo);
261         sysdev_remove_file(&node->sysdev, &attr_numastat);
262         sysdev_remove_file(&node->sysdev, &attr_distance);
263
264         scan_unevictable_unregister_node(node);
265         hugetlb_unregister_node(node);          /* no-op, if memoryless node */
266
267         sysdev_unregister(&node->sysdev);
268 }
269
270 struct node node_devices[MAX_NUMNODES];
271
272 /*
273  * register cpu under node
274  */
275 int register_cpu_under_node(unsigned int cpu, unsigned int nid)
276 {
277         int ret;
278         struct sys_device *obj;
279
280         if (!node_online(nid))
281                 return 0;
282
283         obj = get_cpu_sysdev(cpu);
284         if (!obj)
285                 return 0;
286
287         ret = sysfs_create_link(&node_devices[nid].sysdev.kobj,
288                                 &obj->kobj,
289                                 kobject_name(&obj->kobj));
290         if (ret)
291                 return ret;
292
293         return sysfs_create_link(&obj->kobj,
294                                  &node_devices[nid].sysdev.kobj,
295                                  kobject_name(&node_devices[nid].sysdev.kobj));
296 }
297
298 int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
299 {
300         struct sys_device *obj;
301
302         if (!node_online(nid))
303                 return 0;
304
305         obj = get_cpu_sysdev(cpu);
306         if (!obj)
307                 return 0;
308
309         sysfs_remove_link(&node_devices[nid].sysdev.kobj,
310                           kobject_name(&obj->kobj));
311         sysfs_remove_link(&obj->kobj,
312                           kobject_name(&node_devices[nid].sysdev.kobj));
313
314         return 0;
315 }
316
317 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
318 #define page_initialized(page)  (page->lru.next)
319
320 static int get_nid_for_pfn(unsigned long pfn)
321 {
322         struct page *page;
323
324         if (!pfn_valid_within(pfn))
325                 return -1;
326         page = pfn_to_page(pfn);
327         if (!page_initialized(page))
328                 return -1;
329         return pfn_to_nid(pfn);
330 }
331
332 /* register memory section under specified node if it spans that node */
333 int register_mem_sect_under_node(struct memory_block *mem_blk, int nid)
334 {
335         int ret;
336         unsigned long pfn, sect_start_pfn, sect_end_pfn;
337
338         if (!mem_blk)
339                 return -EFAULT;
340         if (!node_online(nid))
341                 return 0;
342         sect_start_pfn = section_nr_to_pfn(mem_blk->phys_index);
343         sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
344         for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
345                 int page_nid;
346
347                 page_nid = get_nid_for_pfn(pfn);
348                 if (page_nid < 0)
349                         continue;
350                 if (page_nid != nid)
351                         continue;
352                 ret = sysfs_create_link_nowarn(&node_devices[nid].sysdev.kobj,
353                                         &mem_blk->sysdev.kobj,
354                                         kobject_name(&mem_blk->sysdev.kobj));
355                 if (ret)
356                         return ret;
357
358                 return sysfs_create_link_nowarn(&mem_blk->sysdev.kobj,
359                                 &node_devices[nid].sysdev.kobj,
360                                 kobject_name(&node_devices[nid].sysdev.kobj));
361         }
362         /* mem section does not span the specified node */
363         return 0;
364 }
365
366 /* unregister memory section under all nodes that it spans */
367 int unregister_mem_sect_under_nodes(struct memory_block *mem_blk)
368 {
369         NODEMASK_ALLOC(nodemask_t, unlinked_nodes, GFP_KERNEL);
370         unsigned long pfn, sect_start_pfn, sect_end_pfn;
371
372         if (!mem_blk) {
373                 NODEMASK_FREE(unlinked_nodes);
374                 return -EFAULT;
375         }
376         if (!unlinked_nodes)
377                 return -ENOMEM;
378         nodes_clear(*unlinked_nodes);
379         sect_start_pfn = section_nr_to_pfn(mem_blk->phys_index);
380         sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
381         for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
382                 int nid;
383
384                 nid = get_nid_for_pfn(pfn);
385                 if (nid < 0)
386                         continue;
387                 if (!node_online(nid))
388                         continue;
389                 if (node_test_and_set(nid, *unlinked_nodes))
390                         continue;
391                 sysfs_remove_link(&node_devices[nid].sysdev.kobj,
392                          kobject_name(&mem_blk->sysdev.kobj));
393                 sysfs_remove_link(&mem_blk->sysdev.kobj,
394                          kobject_name(&node_devices[nid].sysdev.kobj));
395         }
396         NODEMASK_FREE(unlinked_nodes);
397         return 0;
398 }
399
400 static int link_mem_sections(int nid)
401 {
402         unsigned long start_pfn = NODE_DATA(nid)->node_start_pfn;
403         unsigned long end_pfn = start_pfn + NODE_DATA(nid)->node_spanned_pages;
404         unsigned long pfn;
405         int err = 0;
406
407         for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
408                 unsigned long section_nr = pfn_to_section_nr(pfn);
409                 struct mem_section *mem_sect;
410                 struct memory_block *mem_blk;
411                 int ret;
412
413                 if (!present_section_nr(section_nr))
414                         continue;
415                 mem_sect = __nr_to_section(section_nr);
416                 mem_blk = find_memory_block(mem_sect);
417                 ret = register_mem_sect_under_node(mem_blk, nid);
418                 if (!err)
419                         err = ret;
420
421                 /* discard ref obtained in find_memory_block() */
422                 kobject_put(&mem_blk->sysdev.kobj);
423         }
424         return err;
425 }
426
427 #ifdef CONFIG_HUGETLBFS
428 /*
429  * Handle per node hstate attribute [un]registration on transistions
430  * to/from memoryless state.
431  */
432 static void node_hugetlb_work(struct work_struct *work)
433 {
434         struct node *node = container_of(work, struct node, node_work);
435
436         /*
437          * We only get here when a node transitions to/from memoryless state.
438          * We can detect which transition occurred by examining whether the
439          * node has memory now.  hugetlb_register_node() already check this
440          * so we try to register the attributes.  If that fails, then the
441          * node has transitioned to memoryless, try to unregister the
442          * attributes.
443          */
444         if (!hugetlb_register_node(node))
445                 hugetlb_unregister_node(node);
446 }
447
448 static void init_node_hugetlb_work(int nid)
449 {
450         INIT_WORK(&node_devices[nid].node_work, node_hugetlb_work);
451 }
452
453 static int node_memory_callback(struct notifier_block *self,
454                                 unsigned long action, void *arg)
455 {
456         struct memory_notify *mnb = arg;
457         int nid = mnb->status_change_nid;
458
459         switch (action) {
460         case MEM_ONLINE:
461         case MEM_OFFLINE:
462                 /*
463                  * offload per node hstate [un]registration to a work thread
464                  * when transitioning to/from memoryless state.
465                  */
466                 if (nid != NUMA_NO_NODE)
467                         schedule_work(&node_devices[nid].node_work);
468                 break;
469
470         case MEM_GOING_ONLINE:
471         case MEM_GOING_OFFLINE:
472         case MEM_CANCEL_ONLINE:
473         case MEM_CANCEL_OFFLINE:
474         default:
475                 break;
476         }
477
478         return NOTIFY_OK;
479 }
480 #endif  /* CONFIG_HUGETLBFS */
481 #else   /* !CONFIG_MEMORY_HOTPLUG_SPARSE */
482
483 static int link_mem_sections(int nid) { return 0; }
484 #endif  /* CONFIG_MEMORY_HOTPLUG_SPARSE */
485
486 #if !defined(CONFIG_MEMORY_HOTPLUG_SPARSE) || \
487     !defined(CONFIG_HUGETLBFS)
488 static inline int node_memory_callback(struct notifier_block *self,
489                                 unsigned long action, void *arg)
490 {
491         return NOTIFY_OK;
492 }
493
494 static void init_node_hugetlb_work(int nid) { }
495
496 #endif
497
498 int register_one_node(int nid)
499 {
500         int error = 0;
501         int cpu;
502
503         if (node_online(nid)) {
504                 int p_node = parent_node(nid);
505                 struct node *parent = NULL;
506
507                 if (p_node != nid)
508                         parent = &node_devices[p_node];
509
510                 error = register_node(&node_devices[nid], nid, parent);
511
512                 /* link cpu under this node */
513                 for_each_present_cpu(cpu) {
514                         if (cpu_to_node(cpu) == nid)
515                                 register_cpu_under_node(cpu, nid);
516                 }
517
518                 /* link memory sections under this node */
519                 error = link_mem_sections(nid);
520
521                 /* initialize work queue for memory hot plug */
522                 init_node_hugetlb_work(nid);
523         }
524
525         return error;
526
527 }
528
529 void unregister_one_node(int nid)
530 {
531         unregister_node(&node_devices[nid]);
532 }
533
534 /*
535  * node states attributes
536  */
537
538 static ssize_t print_nodes_state(enum node_states state, char *buf)
539 {
540         int n;
541
542         n = nodelist_scnprintf(buf, PAGE_SIZE, node_states[state]);
543         if (n > 0 && PAGE_SIZE > n + 1) {
544                 *(buf + n++) = '\n';
545                 *(buf + n++) = '\0';
546         }
547         return n;
548 }
549
550 struct node_attr {
551         struct sysdev_class_attribute attr;
552         enum node_states state;
553 };
554
555 static ssize_t show_node_state(struct sysdev_class *class,
556                                struct sysdev_class_attribute *attr, char *buf)
557 {
558         struct node_attr *na = container_of(attr, struct node_attr, attr);
559         return print_nodes_state(na->state, buf);
560 }
561
562 #define _NODE_ATTR(name, state) \
563         { _SYSDEV_CLASS_ATTR(name, 0444, show_node_state, NULL), state }
564
565 static struct node_attr node_state_attr[] = {
566         _NODE_ATTR(possible, N_POSSIBLE),
567         _NODE_ATTR(online, N_ONLINE),
568         _NODE_ATTR(has_normal_memory, N_NORMAL_MEMORY),
569         _NODE_ATTR(has_cpu, N_CPU),
570 #ifdef CONFIG_HIGHMEM
571         _NODE_ATTR(has_high_memory, N_HIGH_MEMORY),
572 #endif
573 };
574
575 static struct sysdev_class_attribute *node_state_attrs[] = {
576         &node_state_attr[0].attr,
577         &node_state_attr[1].attr,
578         &node_state_attr[2].attr,
579         &node_state_attr[3].attr,
580 #ifdef CONFIG_HIGHMEM
581         &node_state_attr[4].attr,
582 #endif
583         NULL
584 };
585
586 #define NODE_CALLBACK_PRI       2       /* lower than SLAB */
587 static int __init register_node_type(void)
588 {
589         int ret;
590
591         BUILD_BUG_ON(ARRAY_SIZE(node_state_attr) != NR_NODE_STATES);
592         BUILD_BUG_ON(ARRAY_SIZE(node_state_attrs)-1 != NR_NODE_STATES);
593
594         ret = sysdev_class_register(&node_class);
595         if (!ret) {
596                 hotplug_memory_notifier(node_memory_callback,
597                                         NODE_CALLBACK_PRI);
598         }
599
600         /*
601          * Note:  we're not going to unregister the node class if we fail
602          * to register the node state class attribute files.
603          */
604         return ret;
605 }
606 postcore_initcall(register_node_type);