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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// SPDX-License-Identifier: GPL-2.0
2/*
3 * Memory subsystem support
4 *
5 * Written by Matt Tolentino <matthew.e.tolentino@intel.com>
6 * Dave Hansen <haveblue@us.ibm.com>
7 *
8 * This file provides the necessary infrastructure to represent
9 * a SPARSEMEM-memory-model system's physical memory in /sysfs.
10 * All arch-independent code that assumes MEMORY_HOTPLUG requires
11 * SPARSEMEM should be contained here, or in mm/memory_hotplug.c.
12 */
13
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/memory_hotplug.h>
21#include <linux/mm.h>
22#include <linux/stat.h>
23#include <linux/slab.h>
24#include <linux/xarray.h>
25
26#include <linux/atomic.h>
27#include <linux/uaccess.h>
28
29#define MEMORY_CLASS_NAME "memory"
30
31static const char *const online_type_to_str[] = {
32 [MMOP_OFFLINE] = "offline",
33 [MMOP_ONLINE] = "online",
34 [MMOP_ONLINE_KERNEL] = "online_kernel",
35 [MMOP_ONLINE_MOVABLE] = "online_movable",
36};
37
38int mhp_online_type_from_str(const char *str)
39{
40 int i;
41
42 for (i = 0; i < ARRAY_SIZE(online_type_to_str); i++) {
43 if (sysfs_streq(str, online_type_to_str[i]))
44 return i;
45 }
46 return -EINVAL;
47}
48
49#define to_memory_block(dev) container_of(dev, struct memory_block, dev)
50
51static int sections_per_block;
52
53static inline unsigned long memory_block_id(unsigned long section_nr)
54{
55 return section_nr / sections_per_block;
56}
57
58static inline unsigned long pfn_to_block_id(unsigned long pfn)
59{
60 return memory_block_id(pfn_to_section_nr(pfn));
61}
62
63static inline unsigned long phys_to_block_id(unsigned long phys)
64{
65 return pfn_to_block_id(PFN_DOWN(phys));
66}
67
68static int memory_subsys_online(struct device *dev);
69static int memory_subsys_offline(struct device *dev);
70
71static struct bus_type memory_subsys = {
72 .name = MEMORY_CLASS_NAME,
73 .dev_name = MEMORY_CLASS_NAME,
74 .online = memory_subsys_online,
75 .offline = memory_subsys_offline,
76};
77
78/*
79 * Memory blocks are cached in a local radix tree to avoid
80 * a costly linear search for the corresponding device on
81 * the subsystem bus.
82 */
83static DEFINE_XARRAY(memory_blocks);
84
85static BLOCKING_NOTIFIER_HEAD(memory_chain);
86
87int register_memory_notifier(struct notifier_block *nb)
88{
89 return blocking_notifier_chain_register(&memory_chain, nb);
90}
91EXPORT_SYMBOL(register_memory_notifier);
92
93void unregister_memory_notifier(struct notifier_block *nb)
94{
95 blocking_notifier_chain_unregister(&memory_chain, nb);
96}
97EXPORT_SYMBOL(unregister_memory_notifier);
98
99static void memory_block_release(struct device *dev)
100{
101 struct memory_block *mem = to_memory_block(dev);
102
103 kfree(mem);
104}
105
106unsigned long __weak memory_block_size_bytes(void)
107{
108 return MIN_MEMORY_BLOCK_SIZE;
109}
110EXPORT_SYMBOL_GPL(memory_block_size_bytes);
111
112/*
113 * Show the first physical section index (number) of this memory block.
114 */
115static ssize_t phys_index_show(struct device *dev,
116 struct device_attribute *attr, char *buf)
117{
118 struct memory_block *mem = to_memory_block(dev);
119 unsigned long phys_index;
120
121 phys_index = mem->start_section_nr / sections_per_block;
122
123 return sysfs_emit(buf, "%08lx\n", phys_index);
124}
125
126/*
127 * Legacy interface that we cannot remove. Always indicate "removable"
128 * with CONFIG_MEMORY_HOTREMOVE - bad heuristic.
129 */
130static ssize_t removable_show(struct device *dev, struct device_attribute *attr,
131 char *buf)
132{
133 return sysfs_emit(buf, "%d\n", (int)IS_ENABLED(CONFIG_MEMORY_HOTREMOVE));
134}
135
136/*
137 * online, offline, going offline, etc.
138 */
139static ssize_t state_show(struct device *dev, struct device_attribute *attr,
140 char *buf)
141{
142 struct memory_block *mem = to_memory_block(dev);
143 const char *output;
144
145 /*
146 * We can probably put these states in a nice little array
147 * so that they're not open-coded
148 */
149 switch (mem->state) {
150 case MEM_ONLINE:
151 output = "online";
152 break;
153 case MEM_OFFLINE:
154 output = "offline";
155 break;
156 case MEM_GOING_OFFLINE:
157 output = "going-offline";
158 break;
159 default:
160 WARN_ON(1);
161 return sysfs_emit(buf, "ERROR-UNKNOWN-%ld\n", mem->state);
162 }
163
164 return sysfs_emit(buf, "%s\n", output);
165}
166
167int memory_notify(unsigned long val, void *v)
168{
169 return blocking_notifier_call_chain(&memory_chain, val, v);
170}
171
172static int memory_block_online(struct memory_block *mem)
173{
174 unsigned long start_pfn = section_nr_to_pfn(mem->start_section_nr);
175 unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block;
176 unsigned long nr_vmemmap_pages = mem->nr_vmemmap_pages;
177 struct zone *zone;
178 int ret;
179
180 zone = zone_for_pfn_range(mem->online_type, mem->nid, start_pfn, nr_pages);
181
182 /*
183 * Although vmemmap pages have a different lifecycle than the pages
184 * they describe (they remain until the memory is unplugged), doing
185 * their initialization and accounting at memory onlining/offlining
186 * stage helps to keep accounting easier to follow - e.g vmemmaps
187 * belong to the same zone as the memory they backed.
188 */
189 if (nr_vmemmap_pages) {
190 ret = mhp_init_memmap_on_memory(start_pfn, nr_vmemmap_pages, zone);
191 if (ret)
192 return ret;
193 }
194
195 ret = online_pages(start_pfn + nr_vmemmap_pages,
196 nr_pages - nr_vmemmap_pages, zone);
197 if (ret) {
198 if (nr_vmemmap_pages)
199 mhp_deinit_memmap_on_memory(start_pfn, nr_vmemmap_pages);
200 return ret;
201 }
202
203 /*
204 * Account once onlining succeeded. If the zone was unpopulated, it is
205 * now already properly populated.
206 */
207 if (nr_vmemmap_pages)
208 adjust_present_page_count(zone, nr_vmemmap_pages);
209
210 return ret;
211}
212
213static int memory_block_offline(struct memory_block *mem)
214{
215 unsigned long start_pfn = section_nr_to_pfn(mem->start_section_nr);
216 unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block;
217 unsigned long nr_vmemmap_pages = mem->nr_vmemmap_pages;
218 struct zone *zone;
219 int ret;
220
221 /*
222 * Unaccount before offlining, such that unpopulated zone and kthreads
223 * can properly be torn down in offline_pages().
224 */
225 if (nr_vmemmap_pages) {
226 zone = page_zone(pfn_to_page(start_pfn));
227 adjust_present_page_count(zone, -nr_vmemmap_pages);
228 }
229
230 ret = offline_pages(start_pfn + nr_vmemmap_pages,
231 nr_pages - nr_vmemmap_pages);
232 if (ret) {
233 /* offline_pages() failed. Account back. */
234 if (nr_vmemmap_pages)
235 adjust_present_page_count(zone, nr_vmemmap_pages);
236 return ret;
237 }
238
239 if (nr_vmemmap_pages)
240 mhp_deinit_memmap_on_memory(start_pfn, nr_vmemmap_pages);
241
242 return ret;
243}
244
245/*
246 * MEMORY_HOTPLUG depends on SPARSEMEM in mm/Kconfig, so it is
247 * OK to have direct references to sparsemem variables in here.
248 */
249static int
250memory_block_action(struct memory_block *mem, unsigned long action)
251{
252 int ret;
253
254 switch (action) {
255 case MEM_ONLINE:
256 ret = memory_block_online(mem);
257 break;
258 case MEM_OFFLINE:
259 ret = memory_block_offline(mem);
260 break;
261 default:
262 WARN(1, KERN_WARNING "%s(%ld, %ld) unknown action: "
263 "%ld\n", __func__, mem->start_section_nr, action, action);
264 ret = -EINVAL;
265 }
266
267 return ret;
268}
269
270static int memory_block_change_state(struct memory_block *mem,
271 unsigned long to_state, unsigned long from_state_req)
272{
273 int ret = 0;
274
275 if (mem->state != from_state_req)
276 return -EINVAL;
277
278 if (to_state == MEM_OFFLINE)
279 mem->state = MEM_GOING_OFFLINE;
280
281 ret = memory_block_action(mem, to_state);
282 mem->state = ret ? from_state_req : to_state;
283
284 return ret;
285}
286
287/* The device lock serializes operations on memory_subsys_[online|offline] */
288static int memory_subsys_online(struct device *dev)
289{
290 struct memory_block *mem = to_memory_block(dev);
291 int ret;
292
293 if (mem->state == MEM_ONLINE)
294 return 0;
295
296 /*
297 * When called via device_online() without configuring the online_type,
298 * we want to default to MMOP_ONLINE.
299 */
300 if (mem->online_type == MMOP_OFFLINE)
301 mem->online_type = MMOP_ONLINE;
302
303 ret = memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE);
304 mem->online_type = MMOP_OFFLINE;
305
306 return ret;
307}
308
309static int memory_subsys_offline(struct device *dev)
310{
311 struct memory_block *mem = to_memory_block(dev);
312
313 if (mem->state == MEM_OFFLINE)
314 return 0;
315
316 return memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE);
317}
318
319static ssize_t state_store(struct device *dev, struct device_attribute *attr,
320 const char *buf, size_t count)
321{
322 const int online_type = mhp_online_type_from_str(buf);
323 struct memory_block *mem = to_memory_block(dev);
324 int ret;
325
326 if (online_type < 0)
327 return -EINVAL;
328
329 ret = lock_device_hotplug_sysfs();
330 if (ret)
331 return ret;
332
333 switch (online_type) {
334 case MMOP_ONLINE_KERNEL:
335 case MMOP_ONLINE_MOVABLE:
336 case MMOP_ONLINE:
337 /* mem->online_type is protected by device_hotplug_lock */
338 mem->online_type = online_type;
339 ret = device_online(&mem->dev);
340 break;
341 case MMOP_OFFLINE:
342 ret = device_offline(&mem->dev);
343 break;
344 default:
345 ret = -EINVAL; /* should never happen */
346 }
347
348 unlock_device_hotplug();
349
350 if (ret < 0)
351 return ret;
352 if (ret)
353 return -EINVAL;
354
355 return count;
356}
357
358/*
359 * Legacy interface that we cannot remove: s390x exposes the storage increment
360 * covered by a memory block, allowing for identifying which memory blocks
361 * comprise a storage increment. Since a memory block spans complete
362 * storage increments nowadays, this interface is basically unused. Other
363 * archs never exposed != 0.
364 */
365static ssize_t phys_device_show(struct device *dev,
366 struct device_attribute *attr, char *buf)
367{
368 struct memory_block *mem = to_memory_block(dev);
369 unsigned long start_pfn = section_nr_to_pfn(mem->start_section_nr);
370
371 return sysfs_emit(buf, "%d\n",
372 arch_get_memory_phys_device(start_pfn));
373}
374
375#ifdef CONFIG_MEMORY_HOTREMOVE
376static int print_allowed_zone(char *buf, int len, int nid,
377 unsigned long start_pfn, unsigned long nr_pages,
378 int online_type, struct zone *default_zone)
379{
380 struct zone *zone;
381
382 zone = zone_for_pfn_range(online_type, nid, start_pfn, nr_pages);
383 if (zone == default_zone)
384 return 0;
385
386 return sysfs_emit_at(buf, len, " %s", zone->name);
387}
388
389static ssize_t valid_zones_show(struct device *dev,
390 struct device_attribute *attr, char *buf)
391{
392 struct memory_block *mem = to_memory_block(dev);
393 unsigned long start_pfn = section_nr_to_pfn(mem->start_section_nr);
394 unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block;
395 struct zone *default_zone;
396 int len = 0;
397 int nid;
398
399 /*
400 * Check the existing zone. Make sure that we do that only on the
401 * online nodes otherwise the page_zone is not reliable
402 */
403 if (mem->state == MEM_ONLINE) {
404 /*
405 * The block contains more than one zone can not be offlined.
406 * This can happen e.g. for ZONE_DMA and ZONE_DMA32
407 */
408 default_zone = test_pages_in_a_zone(start_pfn,
409 start_pfn + nr_pages);
410 if (!default_zone)
411 return sysfs_emit(buf, "%s\n", "none");
412 len += sysfs_emit_at(buf, len, "%s", default_zone->name);
413 goto out;
414 }
415
416 nid = mem->nid;
417 default_zone = zone_for_pfn_range(MMOP_ONLINE, nid, start_pfn,
418 nr_pages);
419
420 len += sysfs_emit_at(buf, len, "%s", default_zone->name);
421 len += print_allowed_zone(buf, len, nid, start_pfn, nr_pages,
422 MMOP_ONLINE_KERNEL, default_zone);
423 len += print_allowed_zone(buf, len, nid, start_pfn, nr_pages,
424 MMOP_ONLINE_MOVABLE, default_zone);
425out:
426 len += sysfs_emit_at(buf, len, "\n");
427 return len;
428}
429static DEVICE_ATTR_RO(valid_zones);
430#endif
431
432static DEVICE_ATTR_RO(phys_index);
433static DEVICE_ATTR_RW(state);
434static DEVICE_ATTR_RO(phys_device);
435static DEVICE_ATTR_RO(removable);
436
437/*
438 * Show the memory block size (shared by all memory blocks).
439 */
440static ssize_t block_size_bytes_show(struct device *dev,
441 struct device_attribute *attr, char *buf)
442{
443 return sysfs_emit(buf, "%lx\n", memory_block_size_bytes());
444}
445
446static DEVICE_ATTR_RO(block_size_bytes);
447
448/*
449 * Memory auto online policy.
450 */
451
452static ssize_t auto_online_blocks_show(struct device *dev,
453 struct device_attribute *attr, char *buf)
454{
455 return sysfs_emit(buf, "%s\n",
456 online_type_to_str[mhp_default_online_type]);
457}
458
459static ssize_t auto_online_blocks_store(struct device *dev,
460 struct device_attribute *attr,
461 const char *buf, size_t count)
462{
463 const int online_type = mhp_online_type_from_str(buf);
464
465 if (online_type < 0)
466 return -EINVAL;
467
468 mhp_default_online_type = online_type;
469 return count;
470}
471
472static DEVICE_ATTR_RW(auto_online_blocks);
473
474/*
475 * Some architectures will have custom drivers to do this, and
476 * will not need to do it from userspace. The fake hot-add code
477 * as well as ppc64 will do all of their discovery in userspace
478 * and will require this interface.
479 */
480#ifdef CONFIG_ARCH_MEMORY_PROBE
481static ssize_t probe_store(struct device *dev, struct device_attribute *attr,
482 const char *buf, size_t count)
483{
484 u64 phys_addr;
485 int nid, ret;
486 unsigned long pages_per_block = PAGES_PER_SECTION * sections_per_block;
487
488 ret = kstrtoull(buf, 0, &phys_addr);
489 if (ret)
490 return ret;
491
492 if (phys_addr & ((pages_per_block << PAGE_SHIFT) - 1))
493 return -EINVAL;
494
495 ret = lock_device_hotplug_sysfs();
496 if (ret)
497 return ret;
498
499 nid = memory_add_physaddr_to_nid(phys_addr);
500 ret = __add_memory(nid, phys_addr,
501 MIN_MEMORY_BLOCK_SIZE * sections_per_block,
502 MHP_NONE);
503
504 if (ret)
505 goto out;
506
507 ret = count;
508out:
509 unlock_device_hotplug();
510 return ret;
511}
512
513static DEVICE_ATTR_WO(probe);
514#endif
515
516#ifdef CONFIG_MEMORY_FAILURE
517/*
518 * Support for offlining pages of memory
519 */
520
521/* Soft offline a page */
522static ssize_t soft_offline_page_store(struct device *dev,
523 struct device_attribute *attr,
524 const char *buf, size_t count)
525{
526 int ret;
527 u64 pfn;
528 if (!capable(CAP_SYS_ADMIN))
529 return -EPERM;
530 if (kstrtoull(buf, 0, &pfn) < 0)
531 return -EINVAL;
532 pfn >>= PAGE_SHIFT;
533 ret = soft_offline_page(pfn, 0);
534 return ret == 0 ? count : ret;
535}
536
537/* Forcibly offline a page, including killing processes. */
538static ssize_t hard_offline_page_store(struct device *dev,
539 struct device_attribute *attr,
540 const char *buf, size_t count)
541{
542 int ret;
543 u64 pfn;
544 if (!capable(CAP_SYS_ADMIN))
545 return -EPERM;
546 if (kstrtoull(buf, 0, &pfn) < 0)
547 return -EINVAL;
548 pfn >>= PAGE_SHIFT;
549 ret = memory_failure(pfn, 0);
550 return ret ? ret : count;
551}
552
553static DEVICE_ATTR_WO(soft_offline_page);
554static DEVICE_ATTR_WO(hard_offline_page);
555#endif
556
557/* See phys_device_show(). */
558int __weak arch_get_memory_phys_device(unsigned long start_pfn)
559{
560 return 0;
561}
562
563/*
564 * A reference for the returned memory block device is acquired.
565 *
566 * Called under device_hotplug_lock.
567 */
568static struct memory_block *find_memory_block_by_id(unsigned long block_id)
569{
570 struct memory_block *mem;
571
572 mem = xa_load(&memory_blocks, block_id);
573 if (mem)
574 get_device(&mem->dev);
575 return mem;
576}
577
578/*
579 * Called under device_hotplug_lock.
580 */
581struct memory_block *find_memory_block(struct mem_section *section)
582{
583 unsigned long block_id = memory_block_id(__section_nr(section));
584
585 return find_memory_block_by_id(block_id);
586}
587
588static struct attribute *memory_memblk_attrs[] = {
589 &dev_attr_phys_index.attr,
590 &dev_attr_state.attr,
591 &dev_attr_phys_device.attr,
592 &dev_attr_removable.attr,
593#ifdef CONFIG_MEMORY_HOTREMOVE
594 &dev_attr_valid_zones.attr,
595#endif
596 NULL
597};
598
599static const struct attribute_group memory_memblk_attr_group = {
600 .attrs = memory_memblk_attrs,
601};
602
603static const struct attribute_group *memory_memblk_attr_groups[] = {
604 &memory_memblk_attr_group,
605 NULL,
606};
607
608/*
609 * register_memory - Setup a sysfs device for a memory block
610 */
611static
612int register_memory(struct memory_block *memory)
613{
614 int ret;
615
616 memory->dev.bus = &memory_subsys;
617 memory->dev.id = memory->start_section_nr / sections_per_block;
618 memory->dev.release = memory_block_release;
619 memory->dev.groups = memory_memblk_attr_groups;
620 memory->dev.offline = memory->state == MEM_OFFLINE;
621
622 ret = device_register(&memory->dev);
623 if (ret) {
624 put_device(&memory->dev);
625 return ret;
626 }
627 ret = xa_err(xa_store(&memory_blocks, memory->dev.id, memory,
628 GFP_KERNEL));
629 if (ret) {
630 put_device(&memory->dev);
631 device_unregister(&memory->dev);
632 }
633 return ret;
634}
635
636static int init_memory_block(unsigned long block_id, unsigned long state,
637 unsigned long nr_vmemmap_pages)
638{
639 struct memory_block *mem;
640 int ret = 0;
641
642 mem = find_memory_block_by_id(block_id);
643 if (mem) {
644 put_device(&mem->dev);
645 return -EEXIST;
646 }
647 mem = kzalloc(sizeof(*mem), GFP_KERNEL);
648 if (!mem)
649 return -ENOMEM;
650
651 mem->start_section_nr = block_id * sections_per_block;
652 mem->state = state;
653 mem->nid = NUMA_NO_NODE;
654 mem->nr_vmemmap_pages = nr_vmemmap_pages;
655
656 ret = register_memory(mem);
657
658 return ret;
659}
660
661static int add_memory_block(unsigned long base_section_nr)
662{
663 int section_count = 0;
664 unsigned long nr;
665
666 for (nr = base_section_nr; nr < base_section_nr + sections_per_block;
667 nr++)
668 if (present_section_nr(nr))
669 section_count++;
670
671 if (section_count == 0)
672 return 0;
673 return init_memory_block(memory_block_id(base_section_nr),
674 MEM_ONLINE, 0);
675}
676
677static void unregister_memory(struct memory_block *memory)
678{
679 if (WARN_ON_ONCE(memory->dev.bus != &memory_subsys))
680 return;
681
682 WARN_ON(xa_erase(&memory_blocks, memory->dev.id) == NULL);
683
684 /* drop the ref. we got via find_memory_block() */
685 put_device(&memory->dev);
686 device_unregister(&memory->dev);
687}
688
689/*
690 * Create memory block devices for the given memory area. Start and size
691 * have to be aligned to memory block granularity. Memory block devices
692 * will be initialized as offline.
693 *
694 * Called under device_hotplug_lock.
695 */
696int create_memory_block_devices(unsigned long start, unsigned long size,
697 unsigned long vmemmap_pages)
698{
699 const unsigned long start_block_id = pfn_to_block_id(PFN_DOWN(start));
700 unsigned long end_block_id = pfn_to_block_id(PFN_DOWN(start + size));
701 struct memory_block *mem;
702 unsigned long block_id;
703 int ret = 0;
704
705 if (WARN_ON_ONCE(!IS_ALIGNED(start, memory_block_size_bytes()) ||
706 !IS_ALIGNED(size, memory_block_size_bytes())))
707 return -EINVAL;
708
709 for (block_id = start_block_id; block_id != end_block_id; block_id++) {
710 ret = init_memory_block(block_id, MEM_OFFLINE, vmemmap_pages);
711 if (ret)
712 break;
713 }
714 if (ret) {
715 end_block_id = block_id;
716 for (block_id = start_block_id; block_id != end_block_id;
717 block_id++) {
718 mem = find_memory_block_by_id(block_id);
719 if (WARN_ON_ONCE(!mem))
720 continue;
721 unregister_memory(mem);
722 }
723 }
724 return ret;
725}
726
727/*
728 * Remove memory block devices for the given memory area. Start and size
729 * have to be aligned to memory block granularity. Memory block devices
730 * have to be offline.
731 *
732 * Called under device_hotplug_lock.
733 */
734void remove_memory_block_devices(unsigned long start, unsigned long size)
735{
736 const unsigned long start_block_id = pfn_to_block_id(PFN_DOWN(start));
737 const unsigned long end_block_id = pfn_to_block_id(PFN_DOWN(start + size));
738 struct memory_block *mem;
739 unsigned long block_id;
740
741 if (WARN_ON_ONCE(!IS_ALIGNED(start, memory_block_size_bytes()) ||
742 !IS_ALIGNED(size, memory_block_size_bytes())))
743 return;
744
745 for (block_id = start_block_id; block_id != end_block_id; block_id++) {
746 mem = find_memory_block_by_id(block_id);
747 if (WARN_ON_ONCE(!mem))
748 continue;
749 unregister_memory_block_under_nodes(mem);
750 unregister_memory(mem);
751 }
752}
753
754/* return true if the memory block is offlined, otherwise, return false */
755bool is_memblock_offlined(struct memory_block *mem)
756{
757 return mem->state == MEM_OFFLINE;
758}
759
760static struct attribute *memory_root_attrs[] = {
761#ifdef CONFIG_ARCH_MEMORY_PROBE
762 &dev_attr_probe.attr,
763#endif
764
765#ifdef CONFIG_MEMORY_FAILURE
766 &dev_attr_soft_offline_page.attr,
767 &dev_attr_hard_offline_page.attr,
768#endif
769
770 &dev_attr_block_size_bytes.attr,
771 &dev_attr_auto_online_blocks.attr,
772 NULL
773};
774
775static const struct attribute_group memory_root_attr_group = {
776 .attrs = memory_root_attrs,
777};
778
779static const struct attribute_group *memory_root_attr_groups[] = {
780 &memory_root_attr_group,
781 NULL,
782};
783
784/*
785 * Initialize the sysfs support for memory devices. At the time this function
786 * is called, we cannot have concurrent creation/deletion of memory block
787 * devices, the device_hotplug_lock is not needed.
788 */
789void __init memory_dev_init(void)
790{
791 int ret;
792 unsigned long block_sz, nr;
793
794 /* Validate the configured memory block size */
795 block_sz = memory_block_size_bytes();
796 if (!is_power_of_2(block_sz) || block_sz < MIN_MEMORY_BLOCK_SIZE)
797 panic("Memory block size not suitable: 0x%lx\n", block_sz);
798 sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;
799
800 ret = subsys_system_register(&memory_subsys, memory_root_attr_groups);
801 if (ret)
802 panic("%s() failed to register subsystem: %d\n", __func__, ret);
803
804 /*
805 * Create entries for memory sections that were found
806 * during boot and have been initialized
807 */
808 for (nr = 0; nr <= __highest_present_section_nr;
809 nr += sections_per_block) {
810 ret = add_memory_block(nr);
811 if (ret)
812 panic("%s() failed to add memory block: %d\n", __func__,
813 ret);
814 }
815}
816
817/**
818 * walk_memory_blocks - walk through all present memory blocks overlapped
819 * by the range [start, start + size)
820 *
821 * @start: start address of the memory range
822 * @size: size of the memory range
823 * @arg: argument passed to func
824 * @func: callback for each memory section walked
825 *
826 * This function walks through all present memory blocks overlapped by the
827 * range [start, start + size), calling func on each memory block.
828 *
829 * In case func() returns an error, walking is aborted and the error is
830 * returned.
831 *
832 * Called under device_hotplug_lock.
833 */
834int walk_memory_blocks(unsigned long start, unsigned long size,
835 void *arg, walk_memory_blocks_func_t func)
836{
837 const unsigned long start_block_id = phys_to_block_id(start);
838 const unsigned long end_block_id = phys_to_block_id(start + size - 1);
839 struct memory_block *mem;
840 unsigned long block_id;
841 int ret = 0;
842
843 if (!size)
844 return 0;
845
846 for (block_id = start_block_id; block_id <= end_block_id; block_id++) {
847 mem = find_memory_block_by_id(block_id);
848 if (!mem)
849 continue;
850
851 ret = func(mem, arg);
852 put_device(&mem->dev);
853 if (ret)
854 break;
855 }
856 return ret;
857}
858
859struct for_each_memory_block_cb_data {
860 walk_memory_blocks_func_t func;
861 void *arg;
862};
863
864static int for_each_memory_block_cb(struct device *dev, void *data)
865{
866 struct memory_block *mem = to_memory_block(dev);
867 struct for_each_memory_block_cb_data *cb_data = data;
868
869 return cb_data->func(mem, cb_data->arg);
870}
871
872/**
873 * for_each_memory_block - walk through all present memory blocks
874 *
875 * @arg: argument passed to func
876 * @func: callback for each memory block walked
877 *
878 * This function walks through all present memory blocks, calling func on
879 * each memory block.
880 *
881 * In case func() returns an error, walking is aborted and the error is
882 * returned.
883 */
884int for_each_memory_block(void *arg, walk_memory_blocks_func_t func)
885{
886 struct for_each_memory_block_cb_data cb_data = {
887 .func = func,
888 .arg = arg,
889 };
890
891 return bus_for_each_dev(&memory_subsys, NULL, &cb_data,
892 for_each_memory_block_cb);
893}