mm: refactor unregister_cpu_under_node()
[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 node_class = {
20         .name = "node",
21 };
22
23
24 static ssize_t node_read_cpumap(struct sys_device *dev, int type, char *buf)
25 {
26         struct node *node_dev = to_node(dev);
27         const struct cpumask *mask = cpumask_of_node(node_dev->sysdev.id);
28         int len;
29
30         /* 2008/04/07: buf currently PAGE_SIZE, need 9 chars per 32 bits. */
31         BUILD_BUG_ON((NR_CPUS/32 * 9) > (PAGE_SIZE-1));
32
33         len = type?
34                 cpulist_scnprintf(buf, PAGE_SIZE-2, mask) :
35                 cpumask_scnprintf(buf, PAGE_SIZE-2, mask);
36         buf[len++] = '\n';
37         buf[len] = '\0';
38         return len;
39 }
40
41 static inline ssize_t node_read_cpumask(struct sys_device *dev,
42                                 struct sysdev_attribute *attr, char *buf)
43 {
44         return node_read_cpumap(dev, 0, buf);
45 }
46 static inline ssize_t node_read_cpulist(struct sys_device *dev,
47                                 struct sysdev_attribute *attr, char *buf)
48 {
49         return node_read_cpumap(dev, 1, buf);
50 }
51
52 static SYSDEV_ATTR(cpumap,  S_IRUGO, node_read_cpumask, NULL);
53 static SYSDEV_ATTR(cpulist, S_IRUGO, node_read_cpulist, NULL);
54
55 #define K(x) ((x) << (PAGE_SHIFT - 10))
56 static ssize_t node_read_meminfo(struct sys_device * dev,
57                         struct sysdev_attribute *attr, char * buf)
58 {
59         int n;
60         int nid = dev->id;
61         struct sysinfo i;
62
63         si_meminfo_node(&i, nid);
64
65         n = sprintf(buf, "\n"
66                        "Node %d MemTotal:       %8lu kB\n"
67                        "Node %d MemFree:        %8lu kB\n"
68                        "Node %d MemUsed:        %8lu kB\n"
69                        "Node %d Active:         %8lu kB\n"
70                        "Node %d Inactive:       %8lu kB\n"
71                        "Node %d Active(anon):   %8lu kB\n"
72                        "Node %d Inactive(anon): %8lu kB\n"
73                        "Node %d Active(file):   %8lu kB\n"
74                        "Node %d Inactive(file): %8lu kB\n"
75                        "Node %d Unevictable:    %8lu kB\n"
76                        "Node %d Mlocked:        %8lu kB\n"
77 #ifdef CONFIG_HIGHMEM
78                        "Node %d HighTotal:      %8lu kB\n"
79                        "Node %d HighFree:       %8lu kB\n"
80                        "Node %d LowTotal:       %8lu kB\n"
81                        "Node %d LowFree:        %8lu kB\n"
82 #endif
83                        "Node %d Dirty:          %8lu kB\n"
84                        "Node %d Writeback:      %8lu kB\n"
85                        "Node %d FilePages:      %8lu kB\n"
86                        "Node %d Mapped:         %8lu kB\n"
87                        "Node %d AnonPages:      %8lu kB\n"
88                        "Node %d Shmem:          %8lu kB\n"
89                        "Node %d KernelStack:    %8lu kB\n"
90                        "Node %d PageTables:     %8lu kB\n"
91                        "Node %d NFS_Unstable:   %8lu kB\n"
92                        "Node %d Bounce:         %8lu kB\n"
93                        "Node %d WritebackTmp:   %8lu kB\n"
94                        "Node %d Slab:           %8lu kB\n"
95                        "Node %d SReclaimable:   %8lu kB\n"
96                        "Node %d SUnreclaim:     %8lu kB\n",
97                        nid, K(i.totalram),
98                        nid, K(i.freeram),
99                        nid, K(i.totalram - i.freeram),
100                        nid, K(node_page_state(nid, NR_ACTIVE_ANON) +
101                                 node_page_state(nid, NR_ACTIVE_FILE)),
102                        nid, K(node_page_state(nid, NR_INACTIVE_ANON) +
103                                 node_page_state(nid, NR_INACTIVE_FILE)),
104                        nid, K(node_page_state(nid, NR_ACTIVE_ANON)),
105                        nid, K(node_page_state(nid, NR_INACTIVE_ANON)),
106                        nid, K(node_page_state(nid, NR_ACTIVE_FILE)),
107                        nid, K(node_page_state(nid, NR_INACTIVE_FILE)),
108                        nid, K(node_page_state(nid, NR_UNEVICTABLE)),
109                        nid, K(node_page_state(nid, NR_MLOCK)),
110 #ifdef CONFIG_HIGHMEM
111                        nid, K(i.totalhigh),
112                        nid, K(i.freehigh),
113                        nid, K(i.totalram - i.totalhigh),
114                        nid, K(i.freeram - i.freehigh),
115 #endif
116                        nid, K(node_page_state(nid, NR_FILE_DIRTY)),
117                        nid, K(node_page_state(nid, NR_WRITEBACK)),
118                        nid, K(node_page_state(nid, NR_FILE_PAGES)),
119                        nid, K(node_page_state(nid, NR_FILE_MAPPED)),
120                        nid, K(node_page_state(nid, NR_ANON_PAGES)),
121                        nid, K(node_page_state(nid, NR_SHMEM)),
122                        nid, node_page_state(nid, NR_KERNEL_STACK) *
123                                 THREAD_SIZE / 1024,
124                        nid, K(node_page_state(nid, NR_PAGETABLE)),
125                        nid, K(node_page_state(nid, NR_UNSTABLE_NFS)),
126                        nid, K(node_page_state(nid, NR_BOUNCE)),
127                        nid, K(node_page_state(nid, NR_WRITEBACK_TEMP)),
128                        nid, K(node_page_state(nid, NR_SLAB_RECLAIMABLE) +
129                                 node_page_state(nid, NR_SLAB_UNRECLAIMABLE)),
130                        nid, K(node_page_state(nid, NR_SLAB_RECLAIMABLE)),
131                        nid, K(node_page_state(nid, NR_SLAB_UNRECLAIMABLE)));
132         n += hugetlb_report_node_meminfo(nid, buf + n);
133         return n;
134 }
135
136 #undef K
137 static SYSDEV_ATTR(meminfo, S_IRUGO, node_read_meminfo, NULL);
138
139 static ssize_t node_read_numastat(struct sys_device * dev,
140                                 struct sysdev_attribute *attr, char * buf)
141 {
142         return sprintf(buf,
143                        "numa_hit %lu\n"
144                        "numa_miss %lu\n"
145                        "numa_foreign %lu\n"
146                        "interleave_hit %lu\n"
147                        "local_node %lu\n"
148                        "other_node %lu\n",
149                        node_page_state(dev->id, NUMA_HIT),
150                        node_page_state(dev->id, NUMA_MISS),
151                        node_page_state(dev->id, NUMA_FOREIGN),
152                        node_page_state(dev->id, NUMA_INTERLEAVE_HIT),
153                        node_page_state(dev->id, NUMA_LOCAL),
154                        node_page_state(dev->id, NUMA_OTHER));
155 }
156 static SYSDEV_ATTR(numastat, S_IRUGO, node_read_numastat, NULL);
157
158 static ssize_t node_read_distance(struct sys_device * dev,
159                         struct sysdev_attribute *attr, char * buf)
160 {
161         int nid = dev->id;
162         int len = 0;
163         int i;
164
165         /* buf currently PAGE_SIZE, need ~4 chars per node */
166         BUILD_BUG_ON(MAX_NUMNODES*4 > PAGE_SIZE/2);
167
168         for_each_online_node(i)
169                 len += sprintf(buf + len, "%s%d", i ? " " : "", node_distance(nid, i));
170
171         len += sprintf(buf + len, "\n");
172         return len;
173 }
174 static SYSDEV_ATTR(distance, S_IRUGO, node_read_distance, NULL);
175
176 #ifdef CONFIG_HUGETLBFS
177 /*
178  * hugetlbfs per node attributes registration interface:
179  * When/if hugetlb[fs] subsystem initializes [sometime after this module],
180  * it will register its per node attributes for all online nodes with
181  * memory.  It will also call register_hugetlbfs_with_node(), below, to
182  * register its attribute registration functions with this node driver.
183  * Once these hooks have been initialized, the node driver will call into
184  * the hugetlb module to [un]register attributes for hot-plugged nodes.
185  */
186 static node_registration_func_t __hugetlb_register_node;
187 static node_registration_func_t __hugetlb_unregister_node;
188
189 static inline bool hugetlb_register_node(struct node *node)
190 {
191         if (__hugetlb_register_node &&
192                         node_state(node->sysdev.id, N_HIGH_MEMORY)) {
193                 __hugetlb_register_node(node);
194                 return true;
195         }
196         return false;
197 }
198
199 static inline void hugetlb_unregister_node(struct node *node)
200 {
201         if (__hugetlb_unregister_node)
202                 __hugetlb_unregister_node(node);
203 }
204
205 void register_hugetlbfs_with_node(node_registration_func_t doregister,
206                                   node_registration_func_t unregister)
207 {
208         __hugetlb_register_node   = doregister;
209         __hugetlb_unregister_node = unregister;
210 }
211 #else
212 static inline void hugetlb_register_node(struct node *node) {}
213
214 static inline void hugetlb_unregister_node(struct node *node) {}
215 #endif
216
217
218 /*
219  * register_node - Setup a sysfs device for a node.
220  * @num - Node number to use when creating the device.
221  *
222  * Initialize and register the node device.
223  */
224 int register_node(struct node *node, int num, struct node *parent)
225 {
226         int error;
227
228         node->sysdev.id = num;
229         node->sysdev.cls = &node_class;
230         error = sysdev_register(&node->sysdev);
231
232         if (!error){
233                 sysdev_create_file(&node->sysdev, &attr_cpumap);
234                 sysdev_create_file(&node->sysdev, &attr_cpulist);
235                 sysdev_create_file(&node->sysdev, &attr_meminfo);
236                 sysdev_create_file(&node->sysdev, &attr_numastat);
237                 sysdev_create_file(&node->sysdev, &attr_distance);
238
239                 scan_unevictable_register_node(node);
240
241                 hugetlb_register_node(node);
242         }
243         return error;
244 }
245
246 /**
247  * unregister_node - unregister a node device
248  * @node: node going away
249  *
250  * Unregisters a node device @node.  All the devices on the node must be
251  * unregistered before calling this function.
252  */
253 void unregister_node(struct node *node)
254 {
255         sysdev_remove_file(&node->sysdev, &attr_cpumap);
256         sysdev_remove_file(&node->sysdev, &attr_cpulist);
257         sysdev_remove_file(&node->sysdev, &attr_meminfo);
258         sysdev_remove_file(&node->sysdev, &attr_numastat);
259         sysdev_remove_file(&node->sysdev, &attr_distance);
260
261         scan_unevictable_unregister_node(node);
262         hugetlb_unregister_node(node);          /* no-op, if memoryless node */
263
264         sysdev_unregister(&node->sysdev);
265 }
266
267 struct node node_devices[MAX_NUMNODES];
268
269 /*
270  * register cpu under node
271  */
272 int register_cpu_under_node(unsigned int cpu, unsigned int nid)
273 {
274         struct sys_device *obj;
275
276         if (!node_online(nid))
277                 return 0;
278
279         obj = get_cpu_sysdev(cpu);
280         if (!obj)
281                 return 0;
282
283         return sysfs_create_link(&node_devices[nid].sysdev.kobj,
284                                 &obj->kobj,
285                                 kobject_name(&obj->kobj));
286 }
287
288 int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
289 {
290         struct sys_device *obj;
291
292         if (!node_online(nid))
293                 return 0;
294
295         obj = get_cpu_sysdev(cpu);
296         if (!obj)
297                 return 0;
298
299         sysfs_remove_link(&node_devices[nid].sysdev.kobj,
300                           kobject_name(&obj->kobj));
301
302         return 0;
303 }
304
305 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
306 #define page_initialized(page)  (page->lru.next)
307
308 static int get_nid_for_pfn(unsigned long pfn)
309 {
310         struct page *page;
311
312         if (!pfn_valid_within(pfn))
313                 return -1;
314         page = pfn_to_page(pfn);
315         if (!page_initialized(page))
316                 return -1;
317         return pfn_to_nid(pfn);
318 }
319
320 /* register memory section under specified node if it spans that node */
321 int register_mem_sect_under_node(struct memory_block *mem_blk, int nid)
322 {
323         int ret;
324         unsigned long pfn, sect_start_pfn, sect_end_pfn;
325
326         if (!mem_blk)
327                 return -EFAULT;
328         if (!node_online(nid))
329                 return 0;
330         sect_start_pfn = section_nr_to_pfn(mem_blk->phys_index);
331         sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
332         for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
333                 int page_nid;
334
335                 page_nid = get_nid_for_pfn(pfn);
336                 if (page_nid < 0)
337                         continue;
338                 if (page_nid != nid)
339                         continue;
340                 ret = sysfs_create_link_nowarn(&node_devices[nid].sysdev.kobj,
341                                         &mem_blk->sysdev.kobj,
342                                         kobject_name(&mem_blk->sysdev.kobj));
343                 if (ret)
344                         return ret;
345
346                 return sysfs_create_link_nowarn(&mem_blk->sysdev.kobj,
347                                 &node_devices[nid].sysdev.kobj,
348                                 kobject_name(&node_devices[nid].sysdev.kobj));
349         }
350         /* mem section does not span the specified node */
351         return 0;
352 }
353
354 /* unregister memory section under all nodes that it spans */
355 int unregister_mem_sect_under_nodes(struct memory_block *mem_blk)
356 {
357         nodemask_t unlinked_nodes;
358         unsigned long pfn, sect_start_pfn, sect_end_pfn;
359
360         if (!mem_blk)
361                 return -EFAULT;
362         nodes_clear(unlinked_nodes);
363         sect_start_pfn = section_nr_to_pfn(mem_blk->phys_index);
364         sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
365         for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
366                 int nid;
367
368                 nid = get_nid_for_pfn(pfn);
369                 if (nid < 0)
370                         continue;
371                 if (!node_online(nid))
372                         continue;
373                 if (node_test_and_set(nid, unlinked_nodes))
374                         continue;
375                 sysfs_remove_link(&node_devices[nid].sysdev.kobj,
376                          kobject_name(&mem_blk->sysdev.kobj));
377                 sysfs_remove_link(&mem_blk->sysdev.kobj,
378                          kobject_name(&node_devices[nid].sysdev.kobj));
379         }
380         return 0;
381 }
382
383 static int link_mem_sections(int nid)
384 {
385         unsigned long start_pfn = NODE_DATA(nid)->node_start_pfn;
386         unsigned long end_pfn = start_pfn + NODE_DATA(nid)->node_spanned_pages;
387         unsigned long pfn;
388         int err = 0;
389
390         for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
391                 unsigned long section_nr = pfn_to_section_nr(pfn);
392                 struct mem_section *mem_sect;
393                 struct memory_block *mem_blk;
394                 int ret;
395
396                 if (!present_section_nr(section_nr))
397                         continue;
398                 mem_sect = __nr_to_section(section_nr);
399                 mem_blk = find_memory_block(mem_sect);
400                 ret = register_mem_sect_under_node(mem_blk, nid);
401                 if (!err)
402                         err = ret;
403
404                 /* discard ref obtained in find_memory_block() */
405                 kobject_put(&mem_blk->sysdev.kobj);
406         }
407         return err;
408 }
409
410 #ifdef CONFIG_HUGETLBFS
411 /*
412  * Handle per node hstate attribute [un]registration on transistions
413  * to/from memoryless state.
414  */
415 static void node_hugetlb_work(struct work_struct *work)
416 {
417         struct node *node = container_of(work, struct node, node_work);
418
419         /*
420          * We only get here when a node transitions to/from memoryless state.
421          * We can detect which transition occurred by examining whether the
422          * node has memory now.  hugetlb_register_node() already check this
423          * so we try to register the attributes.  If that fails, then the
424          * node has transitioned to memoryless, try to unregister the
425          * attributes.
426          */
427         if (!hugetlb_register_node(node))
428                 hugetlb_unregister_node(node);
429 }
430
431 static void init_node_hugetlb_work(int nid)
432 {
433         INIT_WORK(&node_devices[nid].node_work, node_hugetlb_work);
434 }
435
436 static int node_memory_callback(struct notifier_block *self,
437                                 unsigned long action, void *arg)
438 {
439         struct memory_notify *mnb = arg;
440         int nid = mnb->status_change_nid;
441
442         switch (action) {
443         case MEM_ONLINE:
444         case MEM_OFFLINE:
445                 /*
446                  * offload per node hstate [un]registration to a work thread
447                  * when transitioning to/from memoryless state.
448                  */
449                 if (nid != NUMA_NO_NODE)
450                         schedule_work(&node_devices[nid].node_work);
451                 break;
452
453         case MEM_GOING_ONLINE:
454         case MEM_GOING_OFFLINE:
455         case MEM_CANCEL_ONLINE:
456         case MEM_CANCEL_OFFLINE:
457         default:
458                 break;
459         }
460
461         return NOTIFY_OK;
462 }
463 #endif  /* CONFIG_HUGETLBFS */
464 #else   /* !CONFIG_MEMORY_HOTPLUG_SPARSE */
465
466 static int link_mem_sections(int nid) { return 0; }
467 #endif  /* CONFIG_MEMORY_HOTPLUG_SPARSE */
468
469 #if !defined(CONFIG_MEMORY_HOTPLUG_SPARSE) || \
470     !defined(CONFIG_HUGETLBFS)
471 static inline int node_memory_callback(struct notifier_block *self,
472                                 unsigned long action, void *arg)
473 {
474         return NOTIFY_OK;
475 }
476
477 static void init_node_hugetlb_work(int nid) { }
478
479 #endif
480
481 int register_one_node(int nid)
482 {
483         int error = 0;
484         int cpu;
485
486         if (node_online(nid)) {
487                 int p_node = parent_node(nid);
488                 struct node *parent = NULL;
489
490                 if (p_node != nid)
491                         parent = &node_devices[p_node];
492
493                 error = register_node(&node_devices[nid], nid, parent);
494
495                 /* link cpu under this node */
496                 for_each_present_cpu(cpu) {
497                         if (cpu_to_node(cpu) == nid)
498                                 register_cpu_under_node(cpu, nid);
499                 }
500
501                 /* link memory sections under this node */
502                 error = link_mem_sections(nid);
503
504                 /* initialize work queue for memory hot plug */
505                 init_node_hugetlb_work(nid);
506         }
507
508         return error;
509
510 }
511
512 void unregister_one_node(int nid)
513 {
514         unregister_node(&node_devices[nid]);
515 }
516
517 /*
518  * node states attributes
519  */
520
521 static ssize_t print_nodes_state(enum node_states state, char *buf)
522 {
523         int n;
524
525         n = nodelist_scnprintf(buf, PAGE_SIZE, node_states[state]);
526         if (n > 0 && PAGE_SIZE > n + 1) {
527                 *(buf + n++) = '\n';
528                 *(buf + n++) = '\0';
529         }
530         return n;
531 }
532
533 static ssize_t print_nodes_possible(struct sysdev_class *class, char *buf)
534 {
535         return print_nodes_state(N_POSSIBLE, buf);
536 }
537
538 static ssize_t print_nodes_online(struct sysdev_class *class, char *buf)
539 {
540         return print_nodes_state(N_ONLINE, buf);
541 }
542
543 static ssize_t print_nodes_has_normal_memory(struct sysdev_class *class,
544                                                 char *buf)
545 {
546         return print_nodes_state(N_NORMAL_MEMORY, buf);
547 }
548
549 static ssize_t print_nodes_has_cpu(struct sysdev_class *class, char *buf)
550 {
551         return print_nodes_state(N_CPU, buf);
552 }
553
554 static SYSDEV_CLASS_ATTR(possible, 0444, print_nodes_possible, NULL);
555 static SYSDEV_CLASS_ATTR(online, 0444, print_nodes_online, NULL);
556 static SYSDEV_CLASS_ATTR(has_normal_memory, 0444, print_nodes_has_normal_memory,
557                                                                         NULL);
558 static SYSDEV_CLASS_ATTR(has_cpu, 0444, print_nodes_has_cpu, NULL);
559
560 #ifdef CONFIG_HIGHMEM
561 static ssize_t print_nodes_has_high_memory(struct sysdev_class *class,
562                                                  char *buf)
563 {
564         return print_nodes_state(N_HIGH_MEMORY, buf);
565 }
566
567 static SYSDEV_CLASS_ATTR(has_high_memory, 0444, print_nodes_has_high_memory,
568                                                                          NULL);
569 #endif
570
571 struct sysdev_class_attribute *node_state_attr[] = {
572         &attr_possible,
573         &attr_online,
574         &attr_has_normal_memory,
575 #ifdef CONFIG_HIGHMEM
576         &attr_has_high_memory,
577 #endif
578         &attr_has_cpu,
579 };
580
581 static int node_states_init(void)
582 {
583         int i;
584         int err = 0;
585
586         for (i = 0;  i < NR_NODE_STATES; i++) {
587                 int ret;
588                 ret = sysdev_class_create_file(&node_class, node_state_attr[i]);
589                 if (!err)
590                         err = ret;
591         }
592         return err;
593 }
594
595 #define NODE_CALLBACK_PRI       2       /* lower than SLAB */
596 static int __init register_node_type(void)
597 {
598         int ret;
599
600         ret = sysdev_class_register(&node_class);
601         if (!ret) {
602                 ret = node_states_init();
603                 hotplug_memory_notifier(node_memory_callback,
604                                         NODE_CALLBACK_PRI);
605         }
606
607         /*
608          * Note:  we're not going to unregister the node class if we fail
609          * to register the node state class attribute files.
610          */
611         return ret;
612 }
613 postcore_initcall(register_node_type);