FRV: Use generic show_interrupts()
[cris-mirror.git] / drivers / base / memory.c
blob3da6a43b77567d622f0768e6049c71533e55ed0e
1 /*
2 * drivers/base/memory.c - basic Memory class support
4 * Written by Matt Tolentino <matthew.e.tolentino@intel.com>
5 * Dave Hansen <haveblue@us.ibm.com>
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.
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>
27 #include <asm/atomic.h>
28 #include <asm/uaccess.h>
30 static DEFINE_MUTEX(mem_sysfs_mutex);
32 #define MEMORY_CLASS_NAME "memory"
33 #define MIN_MEMORY_BLOCK_SIZE (1 << SECTION_SIZE_BITS)
35 static int sections_per_block;
37 static inline int base_memory_block_id(int section_nr)
39 return section_nr / sections_per_block;
42 static struct sysdev_class memory_sysdev_class = {
43 .name = MEMORY_CLASS_NAME,
46 static const char *memory_uevent_name(struct kset *kset, struct kobject *kobj)
48 return MEMORY_CLASS_NAME;
51 static int memory_uevent(struct kset *kset, struct kobject *obj, struct kobj_uevent_env *env)
53 int retval = 0;
55 return retval;
58 static const struct kset_uevent_ops memory_uevent_ops = {
59 .name = memory_uevent_name,
60 .uevent = memory_uevent,
63 static BLOCKING_NOTIFIER_HEAD(memory_chain);
65 int register_memory_notifier(struct notifier_block *nb)
67 return blocking_notifier_chain_register(&memory_chain, nb);
69 EXPORT_SYMBOL(register_memory_notifier);
71 void unregister_memory_notifier(struct notifier_block *nb)
73 blocking_notifier_chain_unregister(&memory_chain, nb);
75 EXPORT_SYMBOL(unregister_memory_notifier);
77 static ATOMIC_NOTIFIER_HEAD(memory_isolate_chain);
79 int register_memory_isolate_notifier(struct notifier_block *nb)
81 return atomic_notifier_chain_register(&memory_isolate_chain, nb);
83 EXPORT_SYMBOL(register_memory_isolate_notifier);
85 void unregister_memory_isolate_notifier(struct notifier_block *nb)
87 atomic_notifier_chain_unregister(&memory_isolate_chain, nb);
89 EXPORT_SYMBOL(unregister_memory_isolate_notifier);
92 * register_memory - Setup a sysfs device for a memory block
94 static
95 int register_memory(struct memory_block *memory)
97 int error;
99 memory->sysdev.cls = &memory_sysdev_class;
100 memory->sysdev.id = memory->start_section_nr / sections_per_block;
102 error = sysdev_register(&memory->sysdev);
103 return error;
106 static void
107 unregister_memory(struct memory_block *memory)
109 BUG_ON(memory->sysdev.cls != &memory_sysdev_class);
111 /* drop the ref. we got in remove_memory_block() */
112 kobject_put(&memory->sysdev.kobj);
113 sysdev_unregister(&memory->sysdev);
116 unsigned long __weak memory_block_size_bytes(void)
118 return MIN_MEMORY_BLOCK_SIZE;
121 static unsigned long get_memory_block_size(void)
123 unsigned long block_sz;
125 block_sz = memory_block_size_bytes();
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;
133 return block_sz;
137 * use this as the physical section index that this memsection
138 * uses.
141 static ssize_t show_mem_start_phys_index(struct sys_device *dev,
142 struct sysdev_attribute *attr, char *buf)
144 struct memory_block *mem =
145 container_of(dev, struct memory_block, sysdev);
146 unsigned long phys_index;
148 phys_index = mem->start_section_nr / sections_per_block;
149 return sprintf(buf, "%08lx\n", phys_index);
152 static ssize_t show_mem_end_phys_index(struct sys_device *dev,
153 struct sysdev_attribute *attr, char *buf)
155 struct memory_block *mem =
156 container_of(dev, struct memory_block, sysdev);
157 unsigned long phys_index;
159 phys_index = mem->end_section_nr / sections_per_block;
160 return sprintf(buf, "%08lx\n", phys_index);
164 * Show whether the section of memory is likely to be hot-removable
166 static ssize_t show_mem_removable(struct sys_device *dev,
167 struct sysdev_attribute *attr, char *buf)
169 unsigned long i, pfn;
170 int ret = 1;
171 struct memory_block *mem =
172 container_of(dev, struct memory_block, sysdev);
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);
179 return sprintf(buf, "%d\n", ret);
183 * online, offline, going offline, etc.
185 static ssize_t show_mem_state(struct sys_device *dev,
186 struct sysdev_attribute *attr, char *buf)
188 struct memory_block *mem =
189 container_of(dev, struct memory_block, sysdev);
190 ssize_t len = 0;
193 * We can probably put these states in a nice little array
194 * so that they're not open-coded
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;
213 return len;
216 int memory_notify(unsigned long val, void *v)
218 return blocking_notifier_call_chain(&memory_chain, val, v);
221 int memory_isolate_notify(unsigned long val, void *v)
223 return atomic_notifier_call_chain(&memory_isolate_chain, val, v);
227 * MEMORY_HOTPLUG depends on SPARSEMEM in mm/Kconfig, so it is
228 * OK to have direct references to sparsemem variables in here.
230 static int
231 memory_section_action(unsigned long phys_index, unsigned long action)
233 int i;
234 unsigned long start_pfn, start_paddr;
235 struct page *first_page;
236 int ret;
238 first_page = pfn_to_page(phys_index << PFN_SECTION_SHIFT);
241 * The probe routines leave the pages reserved, just
242 * as the bootmem code does. Make sure they're still
243 * that way.
245 if (action == MEM_ONLINE) {
246 for (i = 0; i < PAGES_PER_SECTION; i++) {
247 if (PageReserved(first_page+i))
248 continue;
250 printk(KERN_WARNING "section number %ld page number %d "
251 "not reserved, was it already online?\n",
252 phys_index, i);
253 return -EBUSY;
257 switch (action) {
258 case MEM_ONLINE:
259 start_pfn = page_to_pfn(first_page);
260 ret = online_pages(start_pfn, PAGES_PER_SECTION);
261 break;
262 case MEM_OFFLINE:
263 start_paddr = page_to_pfn(first_page) << PAGE_SHIFT;
264 ret = remove_memory(start_paddr,
265 PAGES_PER_SECTION << PAGE_SHIFT);
266 break;
267 default:
268 WARN(1, KERN_WARNING "%s(%ld, %ld) unknown action: "
269 "%ld\n", __func__, phys_index, action, action);
270 ret = -EINVAL;
273 return ret;
276 static int memory_block_change_state(struct memory_block *mem,
277 unsigned long to_state, unsigned long from_state_req)
279 int i, ret = 0;
281 mutex_lock(&mem->state_mutex);
283 if (mem->state != from_state_req) {
284 ret = -EINVAL;
285 goto out;
288 if (to_state == MEM_OFFLINE)
289 mem->state = MEM_GOING_OFFLINE;
291 for (i = 0; i < sections_per_block; i++) {
292 ret = memory_section_action(mem->start_section_nr + i,
293 to_state);
294 if (ret)
295 break;
298 if (ret) {
299 for (i = 0; i < sections_per_block; i++)
300 memory_section_action(mem->start_section_nr + i,
301 from_state_req);
303 mem->state = from_state_req;
304 } else
305 mem->state = to_state;
307 out:
308 mutex_unlock(&mem->state_mutex);
309 return ret;
312 static ssize_t
313 store_mem_state(struct sys_device *dev,
314 struct sysdev_attribute *attr, const char *buf, size_t count)
316 struct memory_block *mem;
317 int ret = -EINVAL;
319 mem = container_of(dev, struct memory_block, sysdev);
321 if (!strncmp(buf, "online", min((int)count, 6)))
322 ret = memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE);
323 else if(!strncmp(buf, "offline", min((int)count, 7)))
324 ret = memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE);
326 if (ret)
327 return ret;
328 return count;
332 * phys_device is a bad name for this. What I really want
333 * is a way to differentiate between memory ranges that
334 * are part of physical devices that constitute
335 * a complete removable unit or fru.
336 * i.e. do these ranges belong to the same physical device,
337 * s.t. if I offline all of these sections I can then
338 * remove the physical device?
340 static ssize_t show_phys_device(struct sys_device *dev,
341 struct sysdev_attribute *attr, char *buf)
343 struct memory_block *mem =
344 container_of(dev, struct memory_block, sysdev);
345 return sprintf(buf, "%d\n", mem->phys_device);
348 static SYSDEV_ATTR(phys_index, 0444, show_mem_start_phys_index, NULL);
349 static SYSDEV_ATTR(end_phys_index, 0444, show_mem_end_phys_index, NULL);
350 static SYSDEV_ATTR(state, 0644, show_mem_state, store_mem_state);
351 static SYSDEV_ATTR(phys_device, 0444, show_phys_device, NULL);
352 static SYSDEV_ATTR(removable, 0444, show_mem_removable, NULL);
354 #define mem_create_simple_file(mem, attr_name) \
355 sysdev_create_file(&mem->sysdev, &attr_##attr_name)
356 #define mem_remove_simple_file(mem, attr_name) \
357 sysdev_remove_file(&mem->sysdev, &attr_##attr_name)
360 * Block size attribute stuff
362 static ssize_t
363 print_block_size(struct sysdev_class *class, struct sysdev_class_attribute *attr,
364 char *buf)
366 return sprintf(buf, "%lx\n", get_memory_block_size());
369 static SYSDEV_CLASS_ATTR(block_size_bytes, 0444, print_block_size, NULL);
371 static int block_size_init(void)
373 return sysfs_create_file(&memory_sysdev_class.kset.kobj,
374 &attr_block_size_bytes.attr);
378 * Some architectures will have custom drivers to do this, and
379 * will not need to do it from userspace. The fake hot-add code
380 * as well as ppc64 will do all of their discovery in userspace
381 * and will require this interface.
383 #ifdef CONFIG_ARCH_MEMORY_PROBE
384 static ssize_t
385 memory_probe_store(struct class *class, struct class_attribute *attr,
386 const char *buf, size_t count)
388 u64 phys_addr;
389 int nid;
390 int i, ret;
392 phys_addr = simple_strtoull(buf, NULL, 0);
394 for (i = 0; i < sections_per_block; i++) {
395 nid = memory_add_physaddr_to_nid(phys_addr);
396 ret = add_memory(nid, phys_addr,
397 PAGES_PER_SECTION << PAGE_SHIFT);
398 if (ret)
399 break;
401 phys_addr += MIN_MEMORY_BLOCK_SIZE;
404 if (ret)
405 count = ret;
407 return count;
409 static CLASS_ATTR(probe, S_IWUSR, NULL, memory_probe_store);
411 static int memory_probe_init(void)
413 return sysfs_create_file(&memory_sysdev_class.kset.kobj,
414 &class_attr_probe.attr);
416 #else
417 static inline int memory_probe_init(void)
419 return 0;
421 #endif
423 #ifdef CONFIG_MEMORY_FAILURE
425 * Support for offlining pages of memory
428 /* Soft offline a page */
429 static ssize_t
430 store_soft_offline_page(struct class *class,
431 struct class_attribute *attr,
432 const char *buf, size_t count)
434 int ret;
435 u64 pfn;
436 if (!capable(CAP_SYS_ADMIN))
437 return -EPERM;
438 if (strict_strtoull(buf, 0, &pfn) < 0)
439 return -EINVAL;
440 pfn >>= PAGE_SHIFT;
441 if (!pfn_valid(pfn))
442 return -ENXIO;
443 ret = soft_offline_page(pfn_to_page(pfn), 0);
444 return ret == 0 ? count : ret;
447 /* Forcibly offline a page, including killing processes. */
448 static ssize_t
449 store_hard_offline_page(struct class *class,
450 struct class_attribute *attr,
451 const char *buf, size_t count)
453 int ret;
454 u64 pfn;
455 if (!capable(CAP_SYS_ADMIN))
456 return -EPERM;
457 if (strict_strtoull(buf, 0, &pfn) < 0)
458 return -EINVAL;
459 pfn >>= PAGE_SHIFT;
460 ret = __memory_failure(pfn, 0, 0);
461 return ret ? ret : count;
464 static CLASS_ATTR(soft_offline_page, 0644, NULL, store_soft_offline_page);
465 static CLASS_ATTR(hard_offline_page, 0644, NULL, store_hard_offline_page);
467 static __init int memory_fail_init(void)
469 int err;
471 err = sysfs_create_file(&memory_sysdev_class.kset.kobj,
472 &class_attr_soft_offline_page.attr);
473 if (!err)
474 err = sysfs_create_file(&memory_sysdev_class.kset.kobj,
475 &class_attr_hard_offline_page.attr);
476 return err;
478 #else
479 static inline int memory_fail_init(void)
481 return 0;
483 #endif
486 * Note that phys_device is optional. It is here to allow for
487 * differentiation between which *physical* devices each
488 * section belongs to...
490 int __weak arch_get_memory_phys_device(unsigned long start_pfn)
492 return 0;
495 struct memory_block *find_memory_block_hinted(struct mem_section *section,
496 struct memory_block *hint)
498 struct kobject *kobj;
499 struct sys_device *sysdev;
500 struct memory_block *mem;
501 char name[sizeof(MEMORY_CLASS_NAME) + 9 + 1];
502 int block_id = base_memory_block_id(__section_nr(section));
504 kobj = hint ? &hint->sysdev.kobj : NULL;
507 * This only works because we know that section == sysdev->id
508 * slightly redundant with sysdev_register()
510 sprintf(&name[0], "%s%d", MEMORY_CLASS_NAME, block_id);
512 kobj = kset_find_obj_hinted(&memory_sysdev_class.kset, name, kobj);
513 if (!kobj)
514 return NULL;
516 sysdev = container_of(kobj, struct sys_device, kobj);
517 mem = container_of(sysdev, struct memory_block, sysdev);
519 return mem;
523 * For now, we have a linear search to go find the appropriate
524 * memory_block corresponding to a particular phys_index. If
525 * this gets to be a real problem, we can always use a radix
526 * tree or something here.
528 * This could be made generic for all sysdev classes.
530 struct memory_block *find_memory_block(struct mem_section *section)
532 return find_memory_block_hinted(section, NULL);
535 static int init_memory_block(struct memory_block **memory,
536 struct mem_section *section, unsigned long state)
538 struct memory_block *mem;
539 unsigned long start_pfn;
540 int scn_nr;
541 int ret = 0;
543 mem = kzalloc(sizeof(*mem), GFP_KERNEL);
544 if (!mem)
545 return -ENOMEM;
547 scn_nr = __section_nr(section);
548 mem->start_section_nr =
549 base_memory_block_id(scn_nr) * sections_per_block;
550 mem->end_section_nr = mem->start_section_nr + sections_per_block - 1;
551 mem->state = state;
552 mem->section_count++;
553 mutex_init(&mem->state_mutex);
554 start_pfn = section_nr_to_pfn(mem->start_section_nr);
555 mem->phys_device = arch_get_memory_phys_device(start_pfn);
557 ret = register_memory(mem);
558 if (!ret)
559 ret = mem_create_simple_file(mem, phys_index);
560 if (!ret)
561 ret = mem_create_simple_file(mem, end_phys_index);
562 if (!ret)
563 ret = mem_create_simple_file(mem, state);
564 if (!ret)
565 ret = mem_create_simple_file(mem, phys_device);
566 if (!ret)
567 ret = mem_create_simple_file(mem, removable);
569 *memory = mem;
570 return ret;
573 static int add_memory_section(int nid, struct mem_section *section,
574 unsigned long state, enum mem_add_context context)
576 struct memory_block *mem;
577 int ret = 0;
579 mutex_lock(&mem_sysfs_mutex);
581 mem = find_memory_block(section);
582 if (mem) {
583 mem->section_count++;
584 kobject_put(&mem->sysdev.kobj);
585 } else
586 ret = init_memory_block(&mem, section, state);
588 if (!ret) {
589 if (context == HOTPLUG &&
590 mem->section_count == sections_per_block)
591 ret = register_mem_sect_under_node(mem, nid);
594 mutex_unlock(&mem_sysfs_mutex);
595 return ret;
598 int remove_memory_block(unsigned long node_id, struct mem_section *section,
599 int phys_device)
601 struct memory_block *mem;
603 mutex_lock(&mem_sysfs_mutex);
604 mem = find_memory_block(section);
605 unregister_mem_sect_under_nodes(mem, __section_nr(section));
607 mem->section_count--;
608 if (mem->section_count == 0) {
609 mem_remove_simple_file(mem, phys_index);
610 mem_remove_simple_file(mem, end_phys_index);
611 mem_remove_simple_file(mem, state);
612 mem_remove_simple_file(mem, phys_device);
613 mem_remove_simple_file(mem, removable);
614 unregister_memory(mem);
615 kfree(mem);
616 } else
617 kobject_put(&mem->sysdev.kobj);
619 mutex_unlock(&mem_sysfs_mutex);
620 return 0;
624 * need an interface for the VM to add new memory regions,
625 * but without onlining it.
627 int register_new_memory(int nid, struct mem_section *section)
629 return add_memory_section(nid, section, MEM_OFFLINE, HOTPLUG);
632 int unregister_memory_section(struct mem_section *section)
634 if (!present_section(section))
635 return -EINVAL;
637 return remove_memory_block(0, section, 0);
641 * Initialize the sysfs support for memory devices...
643 int __init memory_dev_init(void)
645 unsigned int i;
646 int ret;
647 int err;
648 unsigned long block_sz;
650 memory_sysdev_class.kset.uevent_ops = &memory_uevent_ops;
651 ret = sysdev_class_register(&memory_sysdev_class);
652 if (ret)
653 goto out;
655 block_sz = get_memory_block_size();
656 sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;
659 * Create entries for memory sections that were found
660 * during boot and have been initialized
662 for (i = 0; i < NR_MEM_SECTIONS; i++) {
663 if (!present_section_nr(i))
664 continue;
665 err = add_memory_section(0, __nr_to_section(i), MEM_ONLINE,
666 BOOT);
667 if (!ret)
668 ret = err;
671 err = memory_probe_init();
672 if (!ret)
673 ret = err;
674 err = memory_fail_init();
675 if (!ret)
676 ret = err;
677 err = block_size_init();
678 if (!ret)
679 ret = err;
680 out:
681 if (ret)
682 printk(KERN_ERR "%s() failed: %d\n", __func__, ret);
683 return ret;