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1/*
2 * drivers/base/memory.c - basic Memory class support
3 *
4 * Written by Matt Tolentino <matthew.e.tolentino@intel.com>
5 * Dave Hansen <haveblue@us.ibm.com>
6 *
7 * This file provides the necessary infrastructure to represent
8 * a SPARSEMEM-memory-model system's physical memory in /sysfs.
9 * All arch-independent code that assumes MEMORY_HOTPLUG requires
10 * SPARSEMEM should be contained here, or in mm/memory_hotplug.c.
11 */
12
13#include <linux/sysdev.h>
14#include <linux/module.h>
15#include <linux/init.h>
16#include <linux/topology.h>
17#include <linux/capability.h>
18#include <linux/device.h>
19#include <linux/memory.h>
20#include <linux/kobject.h>
21#include <linux/memory_hotplug.h>
22#include <linux/mm.h>
23#include <linux/mutex.h>
24#include <linux/stat.h>
25#include <linux/slab.h>
26
27#include <linux/atomic.h>
28#include <asm/uaccess.h>
29
30static DEFINE_MUTEX(mem_sysfs_mutex);
31
32#define MEMORY_CLASS_NAME "memory"
33
34static int sections_per_block;
35
36static inline int base_memory_block_id(int section_nr)
37{
38 return section_nr / sections_per_block;
39}
40
41static struct sysdev_class memory_sysdev_class = {
42 .name = MEMORY_CLASS_NAME,
43};
44
45static const char *memory_uevent_name(struct kset *kset, struct kobject *kobj)
46{
47 return MEMORY_CLASS_NAME;
48}
49
50static int memory_uevent(struct kset *kset, struct kobject *obj,
51 struct kobj_uevent_env *env)
52{
53 int retval = 0;
54
55 return retval;
56}
57
58static const struct kset_uevent_ops memory_uevent_ops = {
59 .name = memory_uevent_name,
60 .uevent = memory_uevent,
61};
62
63static BLOCKING_NOTIFIER_HEAD(memory_chain);
64
65int register_memory_notifier(struct notifier_block *nb)
66{
67 return blocking_notifier_chain_register(&memory_chain, nb);
68}
69EXPORT_SYMBOL(register_memory_notifier);
70
71void unregister_memory_notifier(struct notifier_block *nb)
72{
73 blocking_notifier_chain_unregister(&memory_chain, nb);
74}
75EXPORT_SYMBOL(unregister_memory_notifier);
76
77static ATOMIC_NOTIFIER_HEAD(memory_isolate_chain);
78
79int register_memory_isolate_notifier(struct notifier_block *nb)
80{
81 return atomic_notifier_chain_register(&memory_isolate_chain, nb);
82}
83EXPORT_SYMBOL(register_memory_isolate_notifier);
84
85void unregister_memory_isolate_notifier(struct notifier_block *nb)
86{
87 atomic_notifier_chain_unregister(&memory_isolate_chain, nb);
88}
89EXPORT_SYMBOL(unregister_memory_isolate_notifier);
90
91/*
92 * register_memory - Setup a sysfs device for a memory block
93 */
94static
95int register_memory(struct memory_block *memory)
96{
97 int error;
98
99 memory->sysdev.cls = &memory_sysdev_class;
100 memory->sysdev.id = memory->start_section_nr / sections_per_block;
101
102 error = sysdev_register(&memory->sysdev);
103 return error;
104}
105
106static void
107unregister_memory(struct memory_block *memory)
108{
109 BUG_ON(memory->sysdev.cls != &memory_sysdev_class);
110
111 /* drop the ref. we got in remove_memory_block() */
112 kobject_put(&memory->sysdev.kobj);
113 sysdev_unregister(&memory->sysdev);
114}
115
116unsigned long __weak memory_block_size_bytes(void)
117{
118 return MIN_MEMORY_BLOCK_SIZE;
119}
120
121static unsigned long get_memory_block_size(void)
122{
123 unsigned long block_sz;
124
125 block_sz = memory_block_size_bytes();
126
127 /* Validate blk_sz is a power of 2 and not less than section size */
128 if ((block_sz & (block_sz - 1)) || (block_sz < MIN_MEMORY_BLOCK_SIZE)) {
129 WARN_ON(1);
130 block_sz = MIN_MEMORY_BLOCK_SIZE;
131 }
132
133 return block_sz;
134}
135
136/*
137 * use this as the physical section index that this memsection
138 * uses.
139 */
140
141static ssize_t show_mem_start_phys_index(struct sys_device *dev,
142 struct sysdev_attribute *attr, char *buf)
143{
144 struct memory_block *mem =
145 container_of(dev, struct memory_block, sysdev);
146 unsigned long phys_index;
147
148 phys_index = mem->start_section_nr / sections_per_block;
149 return sprintf(buf, "%08lx\n", phys_index);
150}
151
152static ssize_t show_mem_end_phys_index(struct sys_device *dev,
153 struct sysdev_attribute *attr, char *buf)
154{
155 struct memory_block *mem =
156 container_of(dev, struct memory_block, sysdev);
157 unsigned long phys_index;
158
159 phys_index = mem->end_section_nr / sections_per_block;
160 return sprintf(buf, "%08lx\n", phys_index);
161}
162
163/*
164 * Show whether the section of memory is likely to be hot-removable
165 */
166static ssize_t show_mem_removable(struct sys_device *dev,
167 struct sysdev_attribute *attr, char *buf)
168{
169 unsigned long i, pfn;
170 int ret = 1;
171 struct memory_block *mem =
172 container_of(dev, struct memory_block, sysdev);
173
174 for (i = 0; i < sections_per_block; i++) {
175 pfn = section_nr_to_pfn(mem->start_section_nr + i);
176 ret &= is_mem_section_removable(pfn, PAGES_PER_SECTION);
177 }
178
179 return sprintf(buf, "%d\n", ret);
180}
181
182/*
183 * online, offline, going offline, etc.
184 */
185static ssize_t show_mem_state(struct sys_device *dev,
186 struct sysdev_attribute *attr, char *buf)
187{
188 struct memory_block *mem =
189 container_of(dev, struct memory_block, sysdev);
190 ssize_t len = 0;
191
192 /*
193 * We can probably put these states in a nice little array
194 * so that they're not open-coded
195 */
196 switch (mem->state) {
197 case MEM_ONLINE:
198 len = sprintf(buf, "online\n");
199 break;
200 case MEM_OFFLINE:
201 len = sprintf(buf, "offline\n");
202 break;
203 case MEM_GOING_OFFLINE:
204 len = sprintf(buf, "going-offline\n");
205 break;
206 default:
207 len = sprintf(buf, "ERROR-UNKNOWN-%ld\n",
208 mem->state);
209 WARN_ON(1);
210 break;
211 }
212
213 return len;
214}
215
216int memory_notify(unsigned long val, void *v)
217{
218 return blocking_notifier_call_chain(&memory_chain, val, v);
219}
220
221int memory_isolate_notify(unsigned long val, void *v)
222{
223 return atomic_notifier_call_chain(&memory_isolate_chain, val, v);
224}
225
226/*
227 * MEMORY_HOTPLUG depends on SPARSEMEM in mm/Kconfig, so it is
228 * OK to have direct references to sparsemem variables in here.
229 */
230static int
231memory_block_action(unsigned long phys_index, unsigned long action)
232{
233 int i;
234 unsigned long start_pfn, start_paddr;
235 unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block;
236 struct page *first_page;
237 int ret;
238
239 first_page = pfn_to_page(phys_index << PFN_SECTION_SHIFT);
240
241 /*
242 * The probe routines leave the pages reserved, just
243 * as the bootmem code does. Make sure they're still
244 * that way.
245 */
246 if (action == MEM_ONLINE) {
247 for (i = 0; i < nr_pages; i++) {
248 if (PageReserved(first_page+i))
249 continue;
250
251 printk(KERN_WARNING "section number %ld page number %d "
252 "not reserved, was it already online?\n",
253 phys_index, i);
254 return -EBUSY;
255 }
256 }
257
258 switch (action) {
259 case MEM_ONLINE:
260 start_pfn = page_to_pfn(first_page);
261 ret = online_pages(start_pfn, nr_pages);
262 break;
263 case MEM_OFFLINE:
264 start_paddr = page_to_pfn(first_page) << PAGE_SHIFT;
265 ret = remove_memory(start_paddr,
266 nr_pages << PAGE_SHIFT);
267 break;
268 default:
269 WARN(1, KERN_WARNING "%s(%ld, %ld) unknown action: "
270 "%ld\n", __func__, phys_index, action, action);
271 ret = -EINVAL;
272 }
273
274 return ret;
275}
276
277static int memory_block_change_state(struct memory_block *mem,
278 unsigned long to_state, unsigned long from_state_req)
279{
280 int ret = 0;
281
282 mutex_lock(&mem->state_mutex);
283
284 if (mem->state != from_state_req) {
285 ret = -EINVAL;
286 goto out;
287 }
288
289 if (to_state == MEM_OFFLINE)
290 mem->state = MEM_GOING_OFFLINE;
291
292 ret = memory_block_action(mem->start_section_nr, to_state);
293
294 if (ret)
295 mem->state = from_state_req;
296 else
297 mem->state = to_state;
298
299out:
300 mutex_unlock(&mem->state_mutex);
301 return ret;
302}
303
304static ssize_t
305store_mem_state(struct sys_device *dev,
306 struct sysdev_attribute *attr, const char *buf, size_t count)
307{
308 struct memory_block *mem;
309 int ret = -EINVAL;
310
311 mem = container_of(dev, struct memory_block, sysdev);
312
313 if (!strncmp(buf, "online", min((int)count, 6)))
314 ret = memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE);
315 else if(!strncmp(buf, "offline", min((int)count, 7)))
316 ret = memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE);
317
318 if (ret)
319 return ret;
320 return count;
321}
322
323/*
324 * phys_device is a bad name for this. What I really want
325 * is a way to differentiate between memory ranges that
326 * are part of physical devices that constitute
327 * a complete removable unit or fru.
328 * i.e. do these ranges belong to the same physical device,
329 * s.t. if I offline all of these sections I can then
330 * remove the physical device?
331 */
332static ssize_t show_phys_device(struct sys_device *dev,
333 struct sysdev_attribute *attr, char *buf)
334{
335 struct memory_block *mem =
336 container_of(dev, struct memory_block, sysdev);
337 return sprintf(buf, "%d\n", mem->phys_device);
338}
339
340static SYSDEV_ATTR(phys_index, 0444, show_mem_start_phys_index, NULL);
341static SYSDEV_ATTR(end_phys_index, 0444, show_mem_end_phys_index, NULL);
342static SYSDEV_ATTR(state, 0644, show_mem_state, store_mem_state);
343static SYSDEV_ATTR(phys_device, 0444, show_phys_device, NULL);
344static SYSDEV_ATTR(removable, 0444, show_mem_removable, NULL);
345
346#define mem_create_simple_file(mem, attr_name) \
347 sysdev_create_file(&mem->sysdev, &attr_##attr_name)
348#define mem_remove_simple_file(mem, attr_name) \
349 sysdev_remove_file(&mem->sysdev, &attr_##attr_name)
350
351/*
352 * Block size attribute stuff
353 */
354static ssize_t
355print_block_size(struct sysdev_class *class, struct sysdev_class_attribute *attr,
356 char *buf)
357{
358 return sprintf(buf, "%lx\n", get_memory_block_size());
359}
360
361static SYSDEV_CLASS_ATTR(block_size_bytes, 0444, print_block_size, NULL);
362
363static int block_size_init(void)
364{
365 return sysfs_create_file(&memory_sysdev_class.kset.kobj,
366 &attr_block_size_bytes.attr);
367}
368
369/*
370 * Some architectures will have custom drivers to do this, and
371 * will not need to do it from userspace. The fake hot-add code
372 * as well as ppc64 will do all of their discovery in userspace
373 * and will require this interface.
374 */
375#ifdef CONFIG_ARCH_MEMORY_PROBE
376static ssize_t
377memory_probe_store(struct class *class, struct class_attribute *attr,
378 const char *buf, size_t count)
379{
380 u64 phys_addr;
381 int nid;
382 int i, ret;
383
384 phys_addr = simple_strtoull(buf, NULL, 0);
385
386 for (i = 0; i < sections_per_block; i++) {
387 nid = memory_add_physaddr_to_nid(phys_addr);
388 ret = add_memory(nid, phys_addr,
389 PAGES_PER_SECTION << PAGE_SHIFT);
390 if (ret)
391 goto out;
392
393 phys_addr += MIN_MEMORY_BLOCK_SIZE;
394 }
395
396 ret = count;
397out:
398 return ret;
399}
400static CLASS_ATTR(probe, S_IWUSR, NULL, memory_probe_store);
401
402static int memory_probe_init(void)
403{
404 return sysfs_create_file(&memory_sysdev_class.kset.kobj,
405 &class_attr_probe.attr);
406}
407#else
408static inline int memory_probe_init(void)
409{
410 return 0;
411}
412#endif
413
414#ifdef CONFIG_MEMORY_FAILURE
415/*
416 * Support for offlining pages of memory
417 */
418
419/* Soft offline a page */
420static ssize_t
421store_soft_offline_page(struct class *class,
422 struct class_attribute *attr,
423 const char *buf, size_t count)
424{
425 int ret;
426 u64 pfn;
427 if (!capable(CAP_SYS_ADMIN))
428 return -EPERM;
429 if (strict_strtoull(buf, 0, &pfn) < 0)
430 return -EINVAL;
431 pfn >>= PAGE_SHIFT;
432 if (!pfn_valid(pfn))
433 return -ENXIO;
434 ret = soft_offline_page(pfn_to_page(pfn), 0);
435 return ret == 0 ? count : ret;
436}
437
438/* Forcibly offline a page, including killing processes. */
439static ssize_t
440store_hard_offline_page(struct class *class,
441 struct class_attribute *attr,
442 const char *buf, size_t count)
443{
444 int ret;
445 u64 pfn;
446 if (!capable(CAP_SYS_ADMIN))
447 return -EPERM;
448 if (strict_strtoull(buf, 0, &pfn) < 0)
449 return -EINVAL;
450 pfn >>= PAGE_SHIFT;
451 ret = __memory_failure(pfn, 0, 0);
452 return ret ? ret : count;
453}
454
455static CLASS_ATTR(soft_offline_page, 0644, NULL, store_soft_offline_page);
456static CLASS_ATTR(hard_offline_page, 0644, NULL, store_hard_offline_page);
457
458static __init int memory_fail_init(void)
459{
460 int err;
461
462 err = sysfs_create_file(&memory_sysdev_class.kset.kobj,
463 &class_attr_soft_offline_page.attr);
464 if (!err)
465 err = sysfs_create_file(&memory_sysdev_class.kset.kobj,
466 &class_attr_hard_offline_page.attr);
467 return err;
468}
469#else
470static inline int memory_fail_init(void)
471{
472 return 0;
473}
474#endif
475
476/*
477 * Note that phys_device is optional. It is here to allow for
478 * differentiation between which *physical* devices each
479 * section belongs to...
480 */
481int __weak arch_get_memory_phys_device(unsigned long start_pfn)
482{
483 return 0;
484}
485
486struct memory_block *find_memory_block_hinted(struct mem_section *section,
487 struct memory_block *hint)
488{
489 struct kobject *kobj;
490 struct sys_device *sysdev;
491 struct memory_block *mem;
492 char name[sizeof(MEMORY_CLASS_NAME) + 9 + 1];
493 int block_id = base_memory_block_id(__section_nr(section));
494
495 kobj = hint ? &hint->sysdev.kobj : NULL;
496
497 /*
498 * This only works because we know that section == sysdev->id
499 * slightly redundant with sysdev_register()
500 */
501 sprintf(&name[0], "%s%d", MEMORY_CLASS_NAME, block_id);
502
503 kobj = kset_find_obj_hinted(&memory_sysdev_class.kset, name, kobj);
504 if (!kobj)
505 return NULL;
506
507 sysdev = container_of(kobj, struct sys_device, kobj);
508 mem = container_of(sysdev, struct memory_block, sysdev);
509
510 return mem;
511}
512
513/*
514 * For now, we have a linear search to go find the appropriate
515 * memory_block corresponding to a particular phys_index. If
516 * this gets to be a real problem, we can always use a radix
517 * tree or something here.
518 *
519 * This could be made generic for all sysdev classes.
520 */
521struct memory_block *find_memory_block(struct mem_section *section)
522{
523 return find_memory_block_hinted(section, NULL);
524}
525
526static int init_memory_block(struct memory_block **memory,
527 struct mem_section *section, unsigned long state)
528{
529 struct memory_block *mem;
530 unsigned long start_pfn;
531 int scn_nr;
532 int ret = 0;
533
534 mem = kzalloc(sizeof(*mem), GFP_KERNEL);
535 if (!mem)
536 return -ENOMEM;
537
538 scn_nr = __section_nr(section);
539 mem->start_section_nr =
540 base_memory_block_id(scn_nr) * sections_per_block;
541 mem->end_section_nr = mem->start_section_nr + sections_per_block - 1;
542 mem->state = state;
543 mem->section_count++;
544 mutex_init(&mem->state_mutex);
545 start_pfn = section_nr_to_pfn(mem->start_section_nr);
546 mem->phys_device = arch_get_memory_phys_device(start_pfn);
547
548 ret = register_memory(mem);
549 if (!ret)
550 ret = mem_create_simple_file(mem, phys_index);
551 if (!ret)
552 ret = mem_create_simple_file(mem, end_phys_index);
553 if (!ret)
554 ret = mem_create_simple_file(mem, state);
555 if (!ret)
556 ret = mem_create_simple_file(mem, phys_device);
557 if (!ret)
558 ret = mem_create_simple_file(mem, removable);
559
560 *memory = mem;
561 return ret;
562}
563
564static int add_memory_section(int nid, struct mem_section *section,
565 unsigned long state, enum mem_add_context context)
566{
567 struct memory_block *mem;
568 int ret = 0;
569
570 mutex_lock(&mem_sysfs_mutex);
571
572 mem = find_memory_block(section);
573 if (mem) {
574 mem->section_count++;
575 kobject_put(&mem->sysdev.kobj);
576 } else
577 ret = init_memory_block(&mem, section, state);
578
579 if (!ret) {
580 if (context == HOTPLUG &&
581 mem->section_count == sections_per_block)
582 ret = register_mem_sect_under_node(mem, nid);
583 }
584
585 mutex_unlock(&mem_sysfs_mutex);
586 return ret;
587}
588
589int remove_memory_block(unsigned long node_id, struct mem_section *section,
590 int phys_device)
591{
592 struct memory_block *mem;
593
594 mutex_lock(&mem_sysfs_mutex);
595 mem = find_memory_block(section);
596 unregister_mem_sect_under_nodes(mem, __section_nr(section));
597
598 mem->section_count--;
599 if (mem->section_count == 0) {
600 mem_remove_simple_file(mem, phys_index);
601 mem_remove_simple_file(mem, end_phys_index);
602 mem_remove_simple_file(mem, state);
603 mem_remove_simple_file(mem, phys_device);
604 mem_remove_simple_file(mem, removable);
605 unregister_memory(mem);
606 kfree(mem);
607 } else
608 kobject_put(&mem->sysdev.kobj);
609
610 mutex_unlock(&mem_sysfs_mutex);
611 return 0;
612}
613
614/*
615 * need an interface for the VM to add new memory regions,
616 * but without onlining it.
617 */
618int register_new_memory(int nid, struct mem_section *section)
619{
620 return add_memory_section(nid, section, MEM_OFFLINE, HOTPLUG);
621}
622
623int unregister_memory_section(struct mem_section *section)
624{
625 if (!present_section(section))
626 return -EINVAL;
627
628 return remove_memory_block(0, section, 0);
629}
630
631/*
632 * Initialize the sysfs support for memory devices...
633 */
634int __init memory_dev_init(void)
635{
636 unsigned int i;
637 int ret;
638 int err;
639 unsigned long block_sz;
640
641 memory_sysdev_class.kset.uevent_ops = &memory_uevent_ops;
642 ret = sysdev_class_register(&memory_sysdev_class);
643 if (ret)
644 goto out;
645
646 block_sz = get_memory_block_size();
647 sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;
648
649 /*
650 * Create entries for memory sections that were found
651 * during boot and have been initialized
652 */
653 for (i = 0; i < NR_MEM_SECTIONS; i++) {
654 if (!present_section_nr(i))
655 continue;
656 err = add_memory_section(0, __nr_to_section(i), MEM_ONLINE,
657 BOOT);
658 if (!ret)
659 ret = err;
660 }
661
662 err = memory_probe_init();
663 if (!ret)
664 ret = err;
665 err = memory_fail_init();
666 if (!ret)
667 ret = err;
668 err = block_size_init();
669 if (!ret)
670 ret = err;
671out:
672 if (ret)
673 printk(KERN_ERR "%s() failed: %d\n", __func__, ret);
674 return ret;
675}
1/*
2 * Memory subsystem support
3 *
4 * Written by Matt Tolentino <matthew.e.tolentino@intel.com>
5 * Dave Hansen <haveblue@us.ibm.com>
6 *
7 * This file provides the necessary infrastructure to represent
8 * a SPARSEMEM-memory-model system's physical memory in /sysfs.
9 * All arch-independent code that assumes MEMORY_HOTPLUG requires
10 * SPARSEMEM should be contained here, or in mm/memory_hotplug.c.
11 */
12
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/topology.h>
16#include <linux/capability.h>
17#include <linux/device.h>
18#include <linux/memory.h>
19#include <linux/memory_hotplug.h>
20#include <linux/mm.h>
21#include <linux/mutex.h>
22#include <linux/stat.h>
23#include <linux/slab.h>
24
25#include <linux/atomic.h>
26#include <asm/uaccess.h>
27
28static DEFINE_MUTEX(mem_sysfs_mutex);
29
30#define MEMORY_CLASS_NAME "memory"
31
32#define to_memory_block(dev) container_of(dev, struct memory_block, dev)
33
34static int sections_per_block;
35
36static inline int base_memory_block_id(int section_nr)
37{
38 return section_nr / sections_per_block;
39}
40
41static int memory_subsys_online(struct device *dev);
42static int memory_subsys_offline(struct device *dev);
43
44static struct bus_type memory_subsys = {
45 .name = MEMORY_CLASS_NAME,
46 .dev_name = MEMORY_CLASS_NAME,
47 .online = memory_subsys_online,
48 .offline = memory_subsys_offline,
49};
50
51static BLOCKING_NOTIFIER_HEAD(memory_chain);
52
53int register_memory_notifier(struct notifier_block *nb)
54{
55 return blocking_notifier_chain_register(&memory_chain, nb);
56}
57EXPORT_SYMBOL(register_memory_notifier);
58
59void unregister_memory_notifier(struct notifier_block *nb)
60{
61 blocking_notifier_chain_unregister(&memory_chain, nb);
62}
63EXPORT_SYMBOL(unregister_memory_notifier);
64
65static ATOMIC_NOTIFIER_HEAD(memory_isolate_chain);
66
67int register_memory_isolate_notifier(struct notifier_block *nb)
68{
69 return atomic_notifier_chain_register(&memory_isolate_chain, nb);
70}
71EXPORT_SYMBOL(register_memory_isolate_notifier);
72
73void unregister_memory_isolate_notifier(struct notifier_block *nb)
74{
75 atomic_notifier_chain_unregister(&memory_isolate_chain, nb);
76}
77EXPORT_SYMBOL(unregister_memory_isolate_notifier);
78
79static void memory_block_release(struct device *dev)
80{
81 struct memory_block *mem = to_memory_block(dev);
82
83 kfree(mem);
84}
85
86unsigned long __weak memory_block_size_bytes(void)
87{
88 return MIN_MEMORY_BLOCK_SIZE;
89}
90
91static unsigned long get_memory_block_size(void)
92{
93 unsigned long block_sz;
94
95 block_sz = memory_block_size_bytes();
96
97 /* Validate blk_sz is a power of 2 and not less than section size */
98 if ((block_sz & (block_sz - 1)) || (block_sz < MIN_MEMORY_BLOCK_SIZE)) {
99 WARN_ON(1);
100 block_sz = MIN_MEMORY_BLOCK_SIZE;
101 }
102
103 return block_sz;
104}
105
106/*
107 * use this as the physical section index that this memsection
108 * uses.
109 */
110
111static ssize_t show_mem_start_phys_index(struct device *dev,
112 struct device_attribute *attr, char *buf)
113{
114 struct memory_block *mem = to_memory_block(dev);
115 unsigned long phys_index;
116
117 phys_index = mem->start_section_nr / sections_per_block;
118 return sprintf(buf, "%08lx\n", phys_index);
119}
120
121static ssize_t show_mem_end_phys_index(struct device *dev,
122 struct device_attribute *attr, char *buf)
123{
124 struct memory_block *mem = to_memory_block(dev);
125 unsigned long phys_index;
126
127 phys_index = mem->end_section_nr / sections_per_block;
128 return sprintf(buf, "%08lx\n", phys_index);
129}
130
131/*
132 * Show whether the section of memory is likely to be hot-removable
133 */
134static ssize_t show_mem_removable(struct device *dev,
135 struct device_attribute *attr, char *buf)
136{
137 unsigned long i, pfn;
138 int ret = 1;
139 struct memory_block *mem = to_memory_block(dev);
140
141 for (i = 0; i < sections_per_block; i++) {
142 if (!present_section_nr(mem->start_section_nr + i))
143 continue;
144 pfn = section_nr_to_pfn(mem->start_section_nr + i);
145 ret &= is_mem_section_removable(pfn, PAGES_PER_SECTION);
146 }
147
148 return sprintf(buf, "%d\n", ret);
149}
150
151/*
152 * online, offline, going offline, etc.
153 */
154static ssize_t show_mem_state(struct device *dev,
155 struct device_attribute *attr, char *buf)
156{
157 struct memory_block *mem = to_memory_block(dev);
158 ssize_t len = 0;
159
160 /*
161 * We can probably put these states in a nice little array
162 * so that they're not open-coded
163 */
164 switch (mem->state) {
165 case MEM_ONLINE:
166 len = sprintf(buf, "online\n");
167 break;
168 case MEM_OFFLINE:
169 len = sprintf(buf, "offline\n");
170 break;
171 case MEM_GOING_OFFLINE:
172 len = sprintf(buf, "going-offline\n");
173 break;
174 default:
175 len = sprintf(buf, "ERROR-UNKNOWN-%ld\n",
176 mem->state);
177 WARN_ON(1);
178 break;
179 }
180
181 return len;
182}
183
184int memory_notify(unsigned long val, void *v)
185{
186 return blocking_notifier_call_chain(&memory_chain, val, v);
187}
188
189int memory_isolate_notify(unsigned long val, void *v)
190{
191 return atomic_notifier_call_chain(&memory_isolate_chain, val, v);
192}
193
194/*
195 * The probe routines leave the pages reserved, just as the bootmem code does.
196 * Make sure they're still that way.
197 */
198static bool pages_correctly_reserved(unsigned long start_pfn)
199{
200 int i, j;
201 struct page *page;
202 unsigned long pfn = start_pfn;
203
204 /*
205 * memmap between sections is not contiguous except with
206 * SPARSEMEM_VMEMMAP. We lookup the page once per section
207 * and assume memmap is contiguous within each section
208 */
209 for (i = 0; i < sections_per_block; i++, pfn += PAGES_PER_SECTION) {
210 if (WARN_ON_ONCE(!pfn_valid(pfn)))
211 return false;
212 page = pfn_to_page(pfn);
213
214 for (j = 0; j < PAGES_PER_SECTION; j++) {
215 if (PageReserved(page + j))
216 continue;
217
218 printk(KERN_WARNING "section number %ld page number %d "
219 "not reserved, was it already online?\n",
220 pfn_to_section_nr(pfn), j);
221
222 return false;
223 }
224 }
225
226 return true;
227}
228
229/*
230 * MEMORY_HOTPLUG depends on SPARSEMEM in mm/Kconfig, so it is
231 * OK to have direct references to sparsemem variables in here.
232 */
233static int
234memory_block_action(unsigned long phys_index, unsigned long action, int online_type)
235{
236 unsigned long start_pfn;
237 unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block;
238 struct page *first_page;
239 int ret;
240
241 first_page = pfn_to_page(phys_index << PFN_SECTION_SHIFT);
242 start_pfn = page_to_pfn(first_page);
243
244 switch (action) {
245 case MEM_ONLINE:
246 if (!pages_correctly_reserved(start_pfn))
247 return -EBUSY;
248
249 ret = online_pages(start_pfn, nr_pages, online_type);
250 break;
251 case MEM_OFFLINE:
252 ret = offline_pages(start_pfn, nr_pages);
253 break;
254 default:
255 WARN(1, KERN_WARNING "%s(%ld, %ld) unknown action: "
256 "%ld\n", __func__, phys_index, action, action);
257 ret = -EINVAL;
258 }
259
260 return ret;
261}
262
263static int memory_block_change_state(struct memory_block *mem,
264 unsigned long to_state, unsigned long from_state_req)
265{
266 int ret = 0;
267
268 if (mem->state != from_state_req)
269 return -EINVAL;
270
271 if (to_state == MEM_OFFLINE)
272 mem->state = MEM_GOING_OFFLINE;
273
274 ret = memory_block_action(mem->start_section_nr, to_state,
275 mem->online_type);
276
277 mem->state = ret ? from_state_req : to_state;
278
279 return ret;
280}
281
282/* The device lock serializes operations on memory_subsys_[online|offline] */
283static int memory_subsys_online(struct device *dev)
284{
285 struct memory_block *mem = to_memory_block(dev);
286 int ret;
287
288 if (mem->state == MEM_ONLINE)
289 return 0;
290
291 /*
292 * If we are called from store_mem_state(), online_type will be
293 * set >= 0 Otherwise we were called from the device online
294 * attribute and need to set the online_type.
295 */
296 if (mem->online_type < 0)
297 mem->online_type = ONLINE_KEEP;
298
299 ret = memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE);
300
301 /* clear online_type */
302 mem->online_type = -1;
303
304 return ret;
305}
306
307static int memory_subsys_offline(struct device *dev)
308{
309 struct memory_block *mem = to_memory_block(dev);
310
311 if (mem->state == MEM_OFFLINE)
312 return 0;
313
314 return memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE);
315}
316
317static ssize_t
318store_mem_state(struct device *dev,
319 struct device_attribute *attr, const char *buf, size_t count)
320{
321 struct memory_block *mem = to_memory_block(dev);
322 int ret, online_type;
323
324 ret = lock_device_hotplug_sysfs();
325 if (ret)
326 return ret;
327
328 if (!strncmp(buf, "online_kernel", min_t(int, count, 13)))
329 online_type = ONLINE_KERNEL;
330 else if (!strncmp(buf, "online_movable", min_t(int, count, 14)))
331 online_type = ONLINE_MOVABLE;
332 else if (!strncmp(buf, "online", min_t(int, count, 6)))
333 online_type = ONLINE_KEEP;
334 else if (!strncmp(buf, "offline", min_t(int, count, 7)))
335 online_type = -1;
336 else {
337 ret = -EINVAL;
338 goto err;
339 }
340
341 switch (online_type) {
342 case ONLINE_KERNEL:
343 case ONLINE_MOVABLE:
344 case ONLINE_KEEP:
345 /*
346 * mem->online_type is not protected so there can be a
347 * race here. However, when racing online, the first
348 * will succeed and the second will just return as the
349 * block will already be online. The online type
350 * could be either one, but that is expected.
351 */
352 mem->online_type = online_type;
353 ret = device_online(&mem->dev);
354 break;
355 case -1:
356 ret = device_offline(&mem->dev);
357 break;
358 default:
359 ret = -EINVAL; /* should never happen */
360 }
361
362err:
363 unlock_device_hotplug();
364
365 if (ret)
366 return ret;
367 return count;
368}
369
370/*
371 * phys_device is a bad name for this. What I really want
372 * is a way to differentiate between memory ranges that
373 * are part of physical devices that constitute
374 * a complete removable unit or fru.
375 * i.e. do these ranges belong to the same physical device,
376 * s.t. if I offline all of these sections I can then
377 * remove the physical device?
378 */
379static ssize_t show_phys_device(struct device *dev,
380 struct device_attribute *attr, char *buf)
381{
382 struct memory_block *mem = to_memory_block(dev);
383 return sprintf(buf, "%d\n", mem->phys_device);
384}
385
386static DEVICE_ATTR(phys_index, 0444, show_mem_start_phys_index, NULL);
387static DEVICE_ATTR(end_phys_index, 0444, show_mem_end_phys_index, NULL);
388static DEVICE_ATTR(state, 0644, show_mem_state, store_mem_state);
389static DEVICE_ATTR(phys_device, 0444, show_phys_device, NULL);
390static DEVICE_ATTR(removable, 0444, show_mem_removable, NULL);
391
392/*
393 * Block size attribute stuff
394 */
395static ssize_t
396print_block_size(struct device *dev, struct device_attribute *attr,
397 char *buf)
398{
399 return sprintf(buf, "%lx\n", get_memory_block_size());
400}
401
402static DEVICE_ATTR(block_size_bytes, 0444, print_block_size, NULL);
403
404/*
405 * Some architectures will have custom drivers to do this, and
406 * will not need to do it from userspace. The fake hot-add code
407 * as well as ppc64 will do all of their discovery in userspace
408 * and will require this interface.
409 */
410#ifdef CONFIG_ARCH_MEMORY_PROBE
411static ssize_t
412memory_probe_store(struct device *dev, struct device_attribute *attr,
413 const char *buf, size_t count)
414{
415 u64 phys_addr;
416 int nid;
417 int i, ret;
418 unsigned long pages_per_block = PAGES_PER_SECTION * sections_per_block;
419
420 phys_addr = simple_strtoull(buf, NULL, 0);
421
422 if (phys_addr & ((pages_per_block << PAGE_SHIFT) - 1))
423 return -EINVAL;
424
425 for (i = 0; i < sections_per_block; i++) {
426 nid = memory_add_physaddr_to_nid(phys_addr);
427 ret = add_memory(nid, phys_addr,
428 PAGES_PER_SECTION << PAGE_SHIFT);
429 if (ret)
430 goto out;
431
432 phys_addr += MIN_MEMORY_BLOCK_SIZE;
433 }
434
435 ret = count;
436out:
437 return ret;
438}
439
440static DEVICE_ATTR(probe, S_IWUSR, NULL, memory_probe_store);
441#endif
442
443#ifdef CONFIG_MEMORY_FAILURE
444/*
445 * Support for offlining pages of memory
446 */
447
448/* Soft offline a page */
449static ssize_t
450store_soft_offline_page(struct device *dev,
451 struct device_attribute *attr,
452 const char *buf, size_t count)
453{
454 int ret;
455 u64 pfn;
456 if (!capable(CAP_SYS_ADMIN))
457 return -EPERM;
458 if (kstrtoull(buf, 0, &pfn) < 0)
459 return -EINVAL;
460 pfn >>= PAGE_SHIFT;
461 if (!pfn_valid(pfn))
462 return -ENXIO;
463 ret = soft_offline_page(pfn_to_page(pfn), 0);
464 return ret == 0 ? count : ret;
465}
466
467/* Forcibly offline a page, including killing processes. */
468static ssize_t
469store_hard_offline_page(struct device *dev,
470 struct device_attribute *attr,
471 const char *buf, size_t count)
472{
473 int ret;
474 u64 pfn;
475 if (!capable(CAP_SYS_ADMIN))
476 return -EPERM;
477 if (kstrtoull(buf, 0, &pfn) < 0)
478 return -EINVAL;
479 pfn >>= PAGE_SHIFT;
480 ret = memory_failure(pfn, 0, 0);
481 return ret ? ret : count;
482}
483
484static DEVICE_ATTR(soft_offline_page, S_IWUSR, NULL, store_soft_offline_page);
485static DEVICE_ATTR(hard_offline_page, S_IWUSR, NULL, store_hard_offline_page);
486#endif
487
488/*
489 * Note that phys_device is optional. It is here to allow for
490 * differentiation between which *physical* devices each
491 * section belongs to...
492 */
493int __weak arch_get_memory_phys_device(unsigned long start_pfn)
494{
495 return 0;
496}
497
498/*
499 * A reference for the returned object is held and the reference for the
500 * hinted object is released.
501 */
502struct memory_block *find_memory_block_hinted(struct mem_section *section,
503 struct memory_block *hint)
504{
505 int block_id = base_memory_block_id(__section_nr(section));
506 struct device *hintdev = hint ? &hint->dev : NULL;
507 struct device *dev;
508
509 dev = subsys_find_device_by_id(&memory_subsys, block_id, hintdev);
510 if (hint)
511 put_device(&hint->dev);
512 if (!dev)
513 return NULL;
514 return to_memory_block(dev);
515}
516
517/*
518 * For now, we have a linear search to go find the appropriate
519 * memory_block corresponding to a particular phys_index. If
520 * this gets to be a real problem, we can always use a radix
521 * tree or something here.
522 *
523 * This could be made generic for all device subsystems.
524 */
525struct memory_block *find_memory_block(struct mem_section *section)
526{
527 return find_memory_block_hinted(section, NULL);
528}
529
530static struct attribute *memory_memblk_attrs[] = {
531 &dev_attr_phys_index.attr,
532 &dev_attr_end_phys_index.attr,
533 &dev_attr_state.attr,
534 &dev_attr_phys_device.attr,
535 &dev_attr_removable.attr,
536 NULL
537};
538
539static struct attribute_group memory_memblk_attr_group = {
540 .attrs = memory_memblk_attrs,
541};
542
543static const struct attribute_group *memory_memblk_attr_groups[] = {
544 &memory_memblk_attr_group,
545 NULL,
546};
547
548/*
549 * register_memory - Setup a sysfs device for a memory block
550 */
551static
552int register_memory(struct memory_block *memory)
553{
554 memory->dev.bus = &memory_subsys;
555 memory->dev.id = memory->start_section_nr / sections_per_block;
556 memory->dev.release = memory_block_release;
557 memory->dev.groups = memory_memblk_attr_groups;
558 memory->dev.offline = memory->state == MEM_OFFLINE;
559
560 return device_register(&memory->dev);
561}
562
563static int init_memory_block(struct memory_block **memory,
564 struct mem_section *section, unsigned long state)
565{
566 struct memory_block *mem;
567 unsigned long start_pfn;
568 int scn_nr;
569 int ret = 0;
570
571 mem = kzalloc(sizeof(*mem), GFP_KERNEL);
572 if (!mem)
573 return -ENOMEM;
574
575 scn_nr = __section_nr(section);
576 mem->start_section_nr =
577 base_memory_block_id(scn_nr) * sections_per_block;
578 mem->end_section_nr = mem->start_section_nr + sections_per_block - 1;
579 mem->state = state;
580 mem->section_count++;
581 start_pfn = section_nr_to_pfn(mem->start_section_nr);
582 mem->phys_device = arch_get_memory_phys_device(start_pfn);
583
584 ret = register_memory(mem);
585
586 *memory = mem;
587 return ret;
588}
589
590static int add_memory_block(int base_section_nr)
591{
592 struct memory_block *mem;
593 int i, ret, section_count = 0, section_nr;
594
595 for (i = base_section_nr;
596 (i < base_section_nr + sections_per_block) && i < NR_MEM_SECTIONS;
597 i++) {
598 if (!present_section_nr(i))
599 continue;
600 if (section_count == 0)
601 section_nr = i;
602 section_count++;
603 }
604
605 if (section_count == 0)
606 return 0;
607 ret = init_memory_block(&mem, __nr_to_section(section_nr), MEM_ONLINE);
608 if (ret)
609 return ret;
610 mem->section_count = section_count;
611 return 0;
612}
613
614
615/*
616 * need an interface for the VM to add new memory regions,
617 * but without onlining it.
618 */
619int register_new_memory(int nid, struct mem_section *section)
620{
621 int ret = 0;
622 struct memory_block *mem;
623
624 mutex_lock(&mem_sysfs_mutex);
625
626 mem = find_memory_block(section);
627 if (mem) {
628 mem->section_count++;
629 put_device(&mem->dev);
630 } else {
631 ret = init_memory_block(&mem, section, MEM_OFFLINE);
632 if (ret)
633 goto out;
634 }
635
636 if (mem->section_count == sections_per_block)
637 ret = register_mem_sect_under_node(mem, nid);
638out:
639 mutex_unlock(&mem_sysfs_mutex);
640 return ret;
641}
642
643#ifdef CONFIG_MEMORY_HOTREMOVE
644static void
645unregister_memory(struct memory_block *memory)
646{
647 BUG_ON(memory->dev.bus != &memory_subsys);
648
649 /* drop the ref. we got in remove_memory_block() */
650 put_device(&memory->dev);
651 device_unregister(&memory->dev);
652}
653
654static int remove_memory_block(unsigned long node_id,
655 struct mem_section *section, int phys_device)
656{
657 struct memory_block *mem;
658
659 mutex_lock(&mem_sysfs_mutex);
660 mem = find_memory_block(section);
661 unregister_mem_sect_under_nodes(mem, __section_nr(section));
662
663 mem->section_count--;
664 if (mem->section_count == 0)
665 unregister_memory(mem);
666 else
667 put_device(&mem->dev);
668
669 mutex_unlock(&mem_sysfs_mutex);
670 return 0;
671}
672
673int unregister_memory_section(struct mem_section *section)
674{
675 if (!present_section(section))
676 return -EINVAL;
677
678 return remove_memory_block(0, section, 0);
679}
680#endif /* CONFIG_MEMORY_HOTREMOVE */
681
682/* return true if the memory block is offlined, otherwise, return false */
683bool is_memblock_offlined(struct memory_block *mem)
684{
685 return mem->state == MEM_OFFLINE;
686}
687
688static struct attribute *memory_root_attrs[] = {
689#ifdef CONFIG_ARCH_MEMORY_PROBE
690 &dev_attr_probe.attr,
691#endif
692
693#ifdef CONFIG_MEMORY_FAILURE
694 &dev_attr_soft_offline_page.attr,
695 &dev_attr_hard_offline_page.attr,
696#endif
697
698 &dev_attr_block_size_bytes.attr,
699 NULL
700};
701
702static struct attribute_group memory_root_attr_group = {
703 .attrs = memory_root_attrs,
704};
705
706static const struct attribute_group *memory_root_attr_groups[] = {
707 &memory_root_attr_group,
708 NULL,
709};
710
711/*
712 * Initialize the sysfs support for memory devices...
713 */
714int __init memory_dev_init(void)
715{
716 unsigned int i;
717 int ret;
718 int err;
719 unsigned long block_sz;
720
721 ret = subsys_system_register(&memory_subsys, memory_root_attr_groups);
722 if (ret)
723 goto out;
724
725 block_sz = get_memory_block_size();
726 sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;
727
728 /*
729 * Create entries for memory sections that were found
730 * during boot and have been initialized
731 */
732 mutex_lock(&mem_sysfs_mutex);
733 for (i = 0; i < NR_MEM_SECTIONS; i += sections_per_block) {
734 err = add_memory_block(i);
735 if (!ret)
736 ret = err;
737 }
738 mutex_unlock(&mem_sysfs_mutex);
739
740out:
741 if (ret)
742 printk(KERN_ERR "%s() failed: %d\n", __func__, ret);
743 return ret;
744}