Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
[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         /*
169          * buf is currently PAGE_SIZE in length and each node needs 4 chars
170          * at the most (distance + space or newline).
171          */
172         BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE);
173
174         for_each_online_node(i)
175                 len += sprintf(buf + len, "%s%d", i ? " " : "", node_distance(nid, i));
176
177         len += sprintf(buf + len, "\n");
178         return len;
179 }
180 static SYSDEV_ATTR(distance, S_IRUGO, node_read_distance, NULL);
181
182 #ifdef CONFIG_HUGETLBFS
183 /*
184  * hugetlbfs per node attributes registration interface:
185  * When/if hugetlb[fs] subsystem initializes [sometime after this module],
186  * it will register its per node attributes for all online nodes with
187  * memory.  It will also call register_hugetlbfs_with_node(), below, to
188  * register its attribute registration functions with this node driver.
189  * Once these hooks have been initialized, the node driver will call into
190  * the hugetlb module to [un]register attributes for hot-plugged nodes.
191  */
192 static node_registration_func_t __hugetlb_register_node;
193 static node_registration_func_t __hugetlb_unregister_node;
194
195 static inline bool hugetlb_register_node(struct node *node)
196 {
197         if (__hugetlb_register_node &&
198                         node_state(node->sysdev.id, N_HIGH_MEMORY)) {
199                 __hugetlb_register_node(node);
200                 return true;
201         }
202         return false;
203 }
204
205 static inline void hugetlb_unregister_node(struct node *node)
206 {
207         if (__hugetlb_unregister_node)
208                 __hugetlb_unregister_node(node);
209 }
210
211 void register_hugetlbfs_with_node(node_registration_func_t doregister,
212                                   node_registration_func_t unregister)
213 {
214         __hugetlb_register_node   = doregister;
215         __hugetlb_unregister_node = unregister;
216 }
217 #else
218 static inline void hugetlb_register_node(struct node *node) {}
219
220 static inline void hugetlb_unregister_node(struct node *node) {}
221 #endif
222
223
224 /*
225  * register_node - Setup a sysfs device for a node.
226  * @num - Node number to use when creating the device.
227  *
228  * Initialize and register the node device.
229  */
230 int register_node(struct node *node, int num, struct node *parent)
231 {
232         int error;
233
234         node->sysdev.id = num;
235         node->sysdev.cls = &node_class;
236         error = sysdev_register(&node->sysdev);
237
238         if (!error){
239                 sysdev_create_file(&node->sysdev, &attr_cpumap);
240                 sysdev_create_file(&node->sysdev, &attr_cpulist);
241                 sysdev_create_file(&node->sysdev, &attr_meminfo);
242                 sysdev_create_file(&node->sysdev, &attr_numastat);
243                 sysdev_create_file(&node->sysdev, &attr_distance);
244
245                 scan_unevictable_register_node(node);
246
247                 hugetlb_register_node(node);
248         }
249         return error;
250 }
251
252 /**
253  * unregister_node - unregister a node device
254  * @node: node going away
255  *
256  * Unregisters a node device @node.  All the devices on the node must be
257  * unregistered before calling this function.
258  */
259 void unregister_node(struct node *node)
260 {
261         sysdev_remove_file(&node->sysdev, &attr_cpumap);
262         sysdev_remove_file(&node->sysdev, &attr_cpulist);
263         sysdev_remove_file(&node->sysdev, &attr_meminfo);
264         sysdev_remove_file(&node->sysdev, &attr_numastat);
265         sysdev_remove_file(&node->sysdev, &attr_distance);
266
267         scan_unevictable_unregister_node(node);
268         hugetlb_unregister_node(node);          /* no-op, if memoryless node */
269
270         sysdev_unregister(&node->sysdev);
271 }
272
273 struct node node_devices[MAX_NUMNODES];
274
275 /*
276  * register cpu under node
277  */
278 int register_cpu_under_node(unsigned int cpu, unsigned int nid)
279 {
280         int ret;
281         struct sys_device *obj;
282
283         if (!node_online(nid))
284                 return 0;
285
286         obj = get_cpu_sysdev(cpu);
287         if (!obj)
288                 return 0;
289
290         ret = sysfs_create_link(&node_devices[nid].sysdev.kobj,
291                                 &obj->kobj,
292                                 kobject_name(&obj->kobj));
293         if (ret)
294                 return ret;
295
296         return sysfs_create_link(&obj->kobj,
297                                  &node_devices[nid].sysdev.kobj,
298                                  kobject_name(&node_devices[nid].sysdev.kobj));
299 }
300
301 int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
302 {
303         struct sys_device *obj;
304
305         if (!node_online(nid))
306                 return 0;
307
308         obj = get_cpu_sysdev(cpu);
309         if (!obj)
310                 return 0;
311
312         sysfs_remove_link(&node_devices[nid].sysdev.kobj,
313                           kobject_name(&obj->kobj));
314         sysfs_remove_link(&obj->kobj,
315                           kobject_name(&node_devices[nid].sysdev.kobj));
316
317         return 0;
318 }
319
320 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
321 #define page_initialized(page)  (page->lru.next)
322
323 static int get_nid_for_pfn(unsigned long pfn)
324 {
325         struct page *page;
326
327         if (!pfn_valid_within(pfn))
328                 return -1;
329         page = pfn_to_page(pfn);
330         if (!page_initialized(page))
331                 return -1;
332         return pfn_to_nid(pfn);
333 }
334
335 /* register memory section under specified node if it spans that node */
336 int register_mem_sect_under_node(struct memory_block *mem_blk, int nid)
337 {
338         int ret;
339         unsigned long pfn, sect_start_pfn, sect_end_pfn;
340
341         if (!mem_blk)
342                 return -EFAULT;
343         if (!node_online(nid))
344                 return 0;
345         sect_start_pfn = section_nr_to_pfn(mem_blk->phys_index);
346         sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
347         for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
348                 int page_nid;
349
350                 page_nid = get_nid_for_pfn(pfn);
351                 if (page_nid < 0)
352                         continue;
353                 if (page_nid != nid)
354                         continue;
355                 ret = sysfs_create_link_nowarn(&node_devices[nid].sysdev.kobj,
356                                         &mem_blk->sysdev.kobj,
357                                         kobject_name(&mem_blk->sysdev.kobj));
358                 if (ret)
359                         return ret;
360
361                 return sysfs_create_link_nowarn(&mem_blk->sysdev.kobj,
362                                 &node_devices[nid].sysdev.kobj,
363                                 kobject_name(&node_devices[nid].sysdev.kobj));
364         }
365         /* mem section does not span the specified node */
366         return 0;
367 }
368
369 /* unregister memory section under all nodes that it spans */
370 int unregister_mem_sect_under_nodes(struct memory_block *mem_blk)
371 {
372         NODEMASK_ALLOC(nodemask_t, unlinked_nodes, GFP_KERNEL);
373         unsigned long pfn, sect_start_pfn, sect_end_pfn;
374
375         if (!mem_blk) {
376                 NODEMASK_FREE(unlinked_nodes);
377                 return -EFAULT;
378         }
379         if (!unlinked_nodes)
380                 return -ENOMEM;
381         nodes_clear(*unlinked_nodes);
382         sect_start_pfn = section_nr_to_pfn(mem_blk->phys_index);
383         sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
384         for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
385                 int nid;
386
387                 nid = get_nid_for_pfn(pfn);
388                 if (nid < 0)
389                         continue;
390                 if (!node_online(nid))
391                         continue;
392                 if (node_test_and_set(nid, *unlinked_nodes))
393                         continue;
394                 sysfs_remove_link(&node_devices[nid].sysdev.kobj,
395                          kobject_name(&mem_blk->sysdev.kobj));
396                 sysfs_remove_link(&mem_blk->sysdev.kobj,
397                          kobject_name(&node_devices[nid].sysdev.kobj));
398         }
399         NODEMASK_FREE(unlinked_nodes);
400         return 0;
401 }
402
403 static int link_mem_sections(int nid)
404 {
405         unsigned long start_pfn = NODE_DATA(nid)->node_start_pfn;
406         unsigned long end_pfn = start_pfn + NODE_DATA(nid)->node_spanned_pages;
407         unsigned long pfn;
408         int err = 0;
409
410         for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
411                 unsigned long section_nr = pfn_to_section_nr(pfn);
412                 struct mem_section *mem_sect;
413                 struct memory_block *mem_blk;
414                 int ret;
415
416                 if (!present_section_nr(section_nr))
417                         continue;
418                 mem_sect = __nr_to_section(section_nr);
419                 mem_blk = find_memory_block(mem_sect);
420                 ret = register_mem_sect_under_node(mem_blk, nid);
421                 if (!err)
422                         err = ret;
423
424                 /* discard ref obtained in find_memory_block() */
425                 kobject_put(&mem_blk->sysdev.kobj);
426         }
427         return err;
428 }
429
430 #ifdef CONFIG_HUGETLBFS
431 /*
432  * Handle per node hstate attribute [un]registration on transistions
433  * to/from memoryless state.
434  */
435 static void node_hugetlb_work(struct work_struct *work)
436 {
437         struct node *node = container_of(work, struct node, node_work);
438
439         /*
440          * We only get here when a node transitions to/from memoryless state.
441          * We can detect which transition occurred by examining whether the
442          * node has memory now.  hugetlb_register_node() already check this
443          * so we try to register the attributes.  If that fails, then the
444          * node has transitioned to memoryless, try to unregister the
445          * attributes.
446          */
447         if (!hugetlb_register_node(node))
448                 hugetlb_unregister_node(node);
449 }
450
451 static void init_node_hugetlb_work(int nid)
452 {
453         INIT_WORK(&node_devices[nid].node_work, node_hugetlb_work);
454 }
455
456 static int node_memory_callback(struct notifier_block *self,
457                                 unsigned long action, void *arg)
458 {
459         struct memory_notify *mnb = arg;
460         int nid = mnb->status_change_nid;
461
462         switch (action) {
463         case MEM_ONLINE:
464         case MEM_OFFLINE:
465                 /*
466                  * offload per node hstate [un]registration to a work thread
467                  * when transitioning to/from memoryless state.
468                  */
469                 if (nid != NUMA_NO_NODE)
470                         schedule_work(&node_devices[nid].node_work);
471                 break;
472
473         case MEM_GOING_ONLINE:
474         case MEM_GOING_OFFLINE:
475         case MEM_CANCEL_ONLINE:
476         case MEM_CANCEL_OFFLINE:
477         default:
478                 break;
479         }
480
481         return NOTIFY_OK;
482 }
483 #endif  /* CONFIG_HUGETLBFS */
484 #else   /* !CONFIG_MEMORY_HOTPLUG_SPARSE */
485
486 static int link_mem_sections(int nid) { return 0; }
487 #endif  /* CONFIG_MEMORY_HOTPLUG_SPARSE */
488
489 #if !defined(CONFIG_MEMORY_HOTPLUG_SPARSE) || \
490     !defined(CONFIG_HUGETLBFS)
491 static inline int node_memory_callback(struct notifier_block *self,
492                                 unsigned long action, void *arg)
493 {
494         return NOTIFY_OK;
495 }
496
497 static void init_node_hugetlb_work(int nid) { }
498
499 #endif
500
501 int register_one_node(int nid)
502 {
503         int error = 0;
504         int cpu;
505
506         if (node_online(nid)) {
507                 int p_node = parent_node(nid);
508                 struct node *parent = NULL;
509
510                 if (p_node != nid)
511                         parent = &node_devices[p_node];
512
513                 error = register_node(&node_devices[nid], nid, parent);
514
515                 /* link cpu under this node */
516                 for_each_present_cpu(cpu) {
517                         if (cpu_to_node(cpu) == nid)
518                                 register_cpu_under_node(cpu, nid);
519                 }
520
521                 /* link memory sections under this node */
522                 error = link_mem_sections(nid);
523
524                 /* initialize work queue for memory hot plug */
525                 init_node_hugetlb_work(nid);
526         }
527
528         return error;
529
530 }
531
532 void unregister_one_node(int nid)
533 {
534         unregister_node(&node_devices[nid]);
535 }
536
537 /*
538  * node states attributes
539  */
540
541 static ssize_t print_nodes_state(enum node_states state, char *buf)
542 {
543         int n;
544
545         n = nodelist_scnprintf(buf, PAGE_SIZE, node_states[state]);
546         if (n > 0 && PAGE_SIZE > n + 1) {
547                 *(buf + n++) = '\n';
548                 *(buf + n++) = '\0';
549         }
550         return n;
551 }
552
553 struct node_attr {
554         struct sysdev_class_attribute attr;
555         enum node_states state;
556 };
557
558 static ssize_t show_node_state(struct sysdev_class *class,
559                                struct sysdev_class_attribute *attr, char *buf)
560 {
561         struct node_attr *na = container_of(attr, struct node_attr, attr);
562         return print_nodes_state(na->state, buf);
563 }
564
565 #define _NODE_ATTR(name, state) \
566         { _SYSDEV_CLASS_ATTR(name, 0444, show_node_state, NULL), state }
567
568 static struct node_attr node_state_attr[] = {
569         _NODE_ATTR(possible, N_POSSIBLE),
570         _NODE_ATTR(online, N_ONLINE),
571         _NODE_ATTR(has_normal_memory, N_NORMAL_MEMORY),
572         _NODE_ATTR(has_cpu, N_CPU),
573 #ifdef CONFIG_HIGHMEM
574         _NODE_ATTR(has_high_memory, N_HIGH_MEMORY),
575 #endif
576 };
577
578 static struct sysdev_class_attribute *node_state_attrs[] = {
579         &node_state_attr[0].attr,
580         &node_state_attr[1].attr,
581         &node_state_attr[2].attr,
582         &node_state_attr[3].attr,
583 #ifdef CONFIG_HIGHMEM
584         &node_state_attr[4].attr,
585 #endif
586         NULL
587 };
588
589 #define NODE_CALLBACK_PRI       2       /* lower than SLAB */
590 static int __init register_node_type(void)
591 {
592         int ret;
593
594         BUILD_BUG_ON(ARRAY_SIZE(node_state_attr) != NR_NODE_STATES);
595         BUILD_BUG_ON(ARRAY_SIZE(node_state_attrs)-1 != NR_NODE_STATES);
596
597         ret = sysdev_class_register(&node_class);
598         if (!ret) {
599                 hotplug_memory_notifier(node_memory_callback,
600                                         NODE_CALLBACK_PRI);
601         }
602
603         /*
604          * Note:  we're not going to unregister the node class if we fail
605          * to register the node state class attribute files.
606          */
607         return ret;
608 }
609 postcore_initcall(register_node_type);