Commit | Line | Data |
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3947be19 DH |
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> | |
3947be19 | 16 | #include <linux/topology.h> |
c59ede7b | 17 | #include <linux/capability.h> |
3947be19 DH |
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> | |
da19cbcf | 23 | #include <linux/mutex.h> |
9f1b16a5 SL |
24 | #include <linux/stat.h> |
25 | ||
3947be19 DH |
26 | #include <asm/atomic.h> |
27 | #include <asm/uaccess.h> | |
28 | ||
29 | #define MEMORY_CLASS_NAME "memory" | |
30 | ||
31 | static struct sysdev_class memory_sysdev_class = { | |
af5ca3f4 | 32 | .name = MEMORY_CLASS_NAME, |
3947be19 | 33 | }; |
3947be19 | 34 | |
312c004d | 35 | static const char *memory_uevent_name(struct kset *kset, struct kobject *kobj) |
3947be19 DH |
36 | { |
37 | return MEMORY_CLASS_NAME; | |
38 | } | |
39 | ||
9ec0fd4e | 40 | static int memory_uevent(struct kset *kset, struct kobject *obj, struct kobj_uevent_env *env) |
3947be19 DH |
41 | { |
42 | int retval = 0; | |
43 | ||
44 | return retval; | |
45 | } | |
46 | ||
312c004d KS |
47 | static struct kset_uevent_ops memory_uevent_ops = { |
48 | .name = memory_uevent_name, | |
49 | .uevent = memory_uevent, | |
3947be19 DH |
50 | }; |
51 | ||
e041c683 | 52 | static BLOCKING_NOTIFIER_HEAD(memory_chain); |
3947be19 | 53 | |
98a38ebd | 54 | int register_memory_notifier(struct notifier_block *nb) |
3947be19 | 55 | { |
e041c683 | 56 | return blocking_notifier_chain_register(&memory_chain, nb); |
3947be19 | 57 | } |
3c82c30c | 58 | EXPORT_SYMBOL(register_memory_notifier); |
3947be19 | 59 | |
98a38ebd | 60 | void unregister_memory_notifier(struct notifier_block *nb) |
3947be19 | 61 | { |
e041c683 | 62 | blocking_notifier_chain_unregister(&memory_chain, nb); |
3947be19 | 63 | } |
3c82c30c | 64 | EXPORT_SYMBOL(unregister_memory_notifier); |
3947be19 DH |
65 | |
66 | /* | |
67 | * register_memory - Setup a sysfs device for a memory block | |
68 | */ | |
00a41db5 BP |
69 | static |
70 | int register_memory(struct memory_block *memory, struct mem_section *section) | |
3947be19 DH |
71 | { |
72 | int error; | |
73 | ||
74 | memory->sysdev.cls = &memory_sysdev_class; | |
75 | memory->sysdev.id = __section_nr(section); | |
76 | ||
77 | error = sysdev_register(&memory->sysdev); | |
3947be19 DH |
78 | return error; |
79 | } | |
80 | ||
81 | static void | |
00a41db5 | 82 | unregister_memory(struct memory_block *memory, struct mem_section *section) |
3947be19 DH |
83 | { |
84 | BUG_ON(memory->sysdev.cls != &memory_sysdev_class); | |
85 | BUG_ON(memory->sysdev.id != __section_nr(section)); | |
86 | ||
00a41db5 BP |
87 | /* drop the ref. we got in remove_memory_block() */ |
88 | kobject_put(&memory->sysdev.kobj); | |
3947be19 | 89 | sysdev_unregister(&memory->sysdev); |
3947be19 DH |
90 | } |
91 | ||
92 | /* | |
93 | * use this as the physical section index that this memsection | |
94 | * uses. | |
95 | */ | |
96 | ||
4a0b2b4d AK |
97 | static ssize_t show_mem_phys_index(struct sys_device *dev, |
98 | struct sysdev_attribute *attr, char *buf) | |
3947be19 DH |
99 | { |
100 | struct memory_block *mem = | |
101 | container_of(dev, struct memory_block, sysdev); | |
102 | return sprintf(buf, "%08lx\n", mem->phys_index); | |
103 | } | |
104 | ||
5c755e9f BP |
105 | /* |
106 | * Show whether the section of memory is likely to be hot-removable | |
107 | */ | |
1f07be1c SR |
108 | static ssize_t show_mem_removable(struct sys_device *dev, |
109 | struct sysdev_attribute *attr, char *buf) | |
5c755e9f BP |
110 | { |
111 | unsigned long start_pfn; | |
112 | int ret; | |
113 | struct memory_block *mem = | |
114 | container_of(dev, struct memory_block, sysdev); | |
115 | ||
116 | start_pfn = section_nr_to_pfn(mem->phys_index); | |
117 | ret = is_mem_section_removable(start_pfn, PAGES_PER_SECTION); | |
118 | return sprintf(buf, "%d\n", ret); | |
119 | } | |
120 | ||
3947be19 DH |
121 | /* |
122 | * online, offline, going offline, etc. | |
123 | */ | |
4a0b2b4d AK |
124 | static ssize_t show_mem_state(struct sys_device *dev, |
125 | struct sysdev_attribute *attr, char *buf) | |
3947be19 DH |
126 | { |
127 | struct memory_block *mem = | |
128 | container_of(dev, struct memory_block, sysdev); | |
129 | ssize_t len = 0; | |
130 | ||
131 | /* | |
132 | * We can probably put these states in a nice little array | |
133 | * so that they're not open-coded | |
134 | */ | |
135 | switch (mem->state) { | |
136 | case MEM_ONLINE: | |
137 | len = sprintf(buf, "online\n"); | |
138 | break; | |
139 | case MEM_OFFLINE: | |
140 | len = sprintf(buf, "offline\n"); | |
141 | break; | |
142 | case MEM_GOING_OFFLINE: | |
143 | len = sprintf(buf, "going-offline\n"); | |
144 | break; | |
145 | default: | |
146 | len = sprintf(buf, "ERROR-UNKNOWN-%ld\n", | |
147 | mem->state); | |
148 | WARN_ON(1); | |
149 | break; | |
150 | } | |
151 | ||
152 | return len; | |
153 | } | |
154 | ||
7b78d335 | 155 | int memory_notify(unsigned long val, void *v) |
3947be19 | 156 | { |
e041c683 | 157 | return blocking_notifier_call_chain(&memory_chain, val, v); |
3947be19 DH |
158 | } |
159 | ||
160 | /* | |
161 | * MEMORY_HOTPLUG depends on SPARSEMEM in mm/Kconfig, so it is | |
162 | * OK to have direct references to sparsemem variables in here. | |
163 | */ | |
164 | static int | |
165 | memory_block_action(struct memory_block *mem, unsigned long action) | |
166 | { | |
167 | int i; | |
168 | unsigned long psection; | |
169 | unsigned long start_pfn, start_paddr; | |
170 | struct page *first_page; | |
171 | int ret; | |
172 | int old_state = mem->state; | |
173 | ||
174 | psection = mem->phys_index; | |
175 | first_page = pfn_to_page(psection << PFN_SECTION_SHIFT); | |
176 | ||
177 | /* | |
178 | * The probe routines leave the pages reserved, just | |
179 | * as the bootmem code does. Make sure they're still | |
180 | * that way. | |
181 | */ | |
182 | if (action == MEM_ONLINE) { | |
183 | for (i = 0; i < PAGES_PER_SECTION; i++) { | |
184 | if (PageReserved(first_page+i)) | |
185 | continue; | |
186 | ||
187 | printk(KERN_WARNING "section number %ld page number %d " | |
188 | "not reserved, was it already online? \n", | |
189 | psection, i); | |
190 | return -EBUSY; | |
191 | } | |
192 | } | |
193 | ||
194 | switch (action) { | |
195 | case MEM_ONLINE: | |
196 | start_pfn = page_to_pfn(first_page); | |
197 | ret = online_pages(start_pfn, PAGES_PER_SECTION); | |
198 | break; | |
199 | case MEM_OFFLINE: | |
200 | mem->state = MEM_GOING_OFFLINE; | |
3947be19 DH |
201 | start_paddr = page_to_pfn(first_page) << PAGE_SHIFT; |
202 | ret = remove_memory(start_paddr, | |
203 | PAGES_PER_SECTION << PAGE_SHIFT); | |
204 | if (ret) { | |
205 | mem->state = old_state; | |
206 | break; | |
207 | } | |
3947be19 DH |
208 | break; |
209 | default: | |
f810a5cf | 210 | WARN(1, KERN_WARNING "%s(%p, %ld) unknown action: %ld\n", |
2b3a302a | 211 | __func__, mem, action, action); |
3947be19 DH |
212 | ret = -EINVAL; |
213 | } | |
3947be19 DH |
214 | |
215 | return ret; | |
216 | } | |
217 | ||
218 | static int memory_block_change_state(struct memory_block *mem, | |
219 | unsigned long to_state, unsigned long from_state_req) | |
220 | { | |
221 | int ret = 0; | |
da19cbcf | 222 | mutex_lock(&mem->state_mutex); |
3947be19 DH |
223 | |
224 | if (mem->state != from_state_req) { | |
225 | ret = -EINVAL; | |
226 | goto out; | |
227 | } | |
228 | ||
229 | ret = memory_block_action(mem, to_state); | |
230 | if (!ret) | |
231 | mem->state = to_state; | |
232 | ||
233 | out: | |
da19cbcf | 234 | mutex_unlock(&mem->state_mutex); |
3947be19 DH |
235 | return ret; |
236 | } | |
237 | ||
238 | static ssize_t | |
4a0b2b4d AK |
239 | store_mem_state(struct sys_device *dev, |
240 | struct sysdev_attribute *attr, const char *buf, size_t count) | |
3947be19 DH |
241 | { |
242 | struct memory_block *mem; | |
243 | unsigned int phys_section_nr; | |
244 | int ret = -EINVAL; | |
245 | ||
246 | mem = container_of(dev, struct memory_block, sysdev); | |
247 | phys_section_nr = mem->phys_index; | |
248 | ||
540557b9 | 249 | if (!present_section_nr(phys_section_nr)) |
3947be19 DH |
250 | goto out; |
251 | ||
252 | if (!strncmp(buf, "online", min((int)count, 6))) | |
253 | ret = memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE); | |
254 | else if(!strncmp(buf, "offline", min((int)count, 7))) | |
255 | ret = memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE); | |
256 | out: | |
257 | if (ret) | |
258 | return ret; | |
259 | return count; | |
260 | } | |
261 | ||
262 | /* | |
263 | * phys_device is a bad name for this. What I really want | |
264 | * is a way to differentiate between memory ranges that | |
265 | * are part of physical devices that constitute | |
266 | * a complete removable unit or fru. | |
267 | * i.e. do these ranges belong to the same physical device, | |
268 | * s.t. if I offline all of these sections I can then | |
269 | * remove the physical device? | |
270 | */ | |
4a0b2b4d AK |
271 | static ssize_t show_phys_device(struct sys_device *dev, |
272 | struct sysdev_attribute *attr, char *buf) | |
3947be19 DH |
273 | { |
274 | struct memory_block *mem = | |
275 | container_of(dev, struct memory_block, sysdev); | |
276 | return sprintf(buf, "%d\n", mem->phys_device); | |
277 | } | |
278 | ||
279 | static SYSDEV_ATTR(phys_index, 0444, show_mem_phys_index, NULL); | |
280 | static SYSDEV_ATTR(state, 0644, show_mem_state, store_mem_state); | |
281 | static SYSDEV_ATTR(phys_device, 0444, show_phys_device, NULL); | |
5c755e9f | 282 | static SYSDEV_ATTR(removable, 0444, show_mem_removable, NULL); |
3947be19 DH |
283 | |
284 | #define mem_create_simple_file(mem, attr_name) \ | |
285 | sysdev_create_file(&mem->sysdev, &attr_##attr_name) | |
286 | #define mem_remove_simple_file(mem, attr_name) \ | |
287 | sysdev_remove_file(&mem->sysdev, &attr_##attr_name) | |
288 | ||
289 | /* | |
290 | * Block size attribute stuff | |
291 | */ | |
292 | static ssize_t | |
293 | print_block_size(struct class *class, char *buf) | |
294 | { | |
295 | return sprintf(buf, "%lx\n", (unsigned long)PAGES_PER_SECTION * PAGE_SIZE); | |
296 | } | |
297 | ||
298 | static CLASS_ATTR(block_size_bytes, 0444, print_block_size, NULL); | |
299 | ||
300 | static int block_size_init(void) | |
301 | { | |
28ec24e2 AM |
302 | return sysfs_create_file(&memory_sysdev_class.kset.kobj, |
303 | &class_attr_block_size_bytes.attr); | |
3947be19 DH |
304 | } |
305 | ||
306 | /* | |
307 | * Some architectures will have custom drivers to do this, and | |
308 | * will not need to do it from userspace. The fake hot-add code | |
309 | * as well as ppc64 will do all of their discovery in userspace | |
310 | * and will require this interface. | |
311 | */ | |
312 | #ifdef CONFIG_ARCH_MEMORY_PROBE | |
313 | static ssize_t | |
be7ee9b2 | 314 | memory_probe_store(struct class *class, const char *buf, size_t count) |
3947be19 DH |
315 | { |
316 | u64 phys_addr; | |
bc02af93 | 317 | int nid; |
3947be19 DH |
318 | int ret; |
319 | ||
320 | phys_addr = simple_strtoull(buf, NULL, 0); | |
321 | ||
bc02af93 YG |
322 | nid = memory_add_physaddr_to_nid(phys_addr); |
323 | ret = add_memory(nid, phys_addr, PAGES_PER_SECTION << PAGE_SHIFT); | |
3947be19 DH |
324 | |
325 | if (ret) | |
326 | count = ret; | |
327 | ||
328 | return count; | |
329 | } | |
9f1b16a5 | 330 | static CLASS_ATTR(probe, S_IWUSR, NULL, memory_probe_store); |
3947be19 DH |
331 | |
332 | static int memory_probe_init(void) | |
333 | { | |
28ec24e2 AM |
334 | return sysfs_create_file(&memory_sysdev_class.kset.kobj, |
335 | &class_attr_probe.attr); | |
3947be19 DH |
336 | } |
337 | #else | |
28ec24e2 AM |
338 | static inline int memory_probe_init(void) |
339 | { | |
340 | return 0; | |
341 | } | |
3947be19 DH |
342 | #endif |
343 | ||
344 | /* | |
345 | * Note that phys_device is optional. It is here to allow for | |
346 | * differentiation between which *physical* devices each | |
347 | * section belongs to... | |
348 | */ | |
349 | ||
c04fc586 GH |
350 | static int add_memory_block(int nid, struct mem_section *section, |
351 | unsigned long state, int phys_device, | |
352 | enum mem_add_context context) | |
3947be19 | 353 | { |
0b0acbec | 354 | struct memory_block *mem = kzalloc(sizeof(*mem), GFP_KERNEL); |
3947be19 DH |
355 | int ret = 0; |
356 | ||
357 | if (!mem) | |
358 | return -ENOMEM; | |
359 | ||
3947be19 DH |
360 | mem->phys_index = __section_nr(section); |
361 | mem->state = state; | |
da19cbcf | 362 | mutex_init(&mem->state_mutex); |
3947be19 DH |
363 | mem->phys_device = phys_device; |
364 | ||
00a41db5 | 365 | ret = register_memory(mem, section); |
3947be19 DH |
366 | if (!ret) |
367 | ret = mem_create_simple_file(mem, phys_index); | |
368 | if (!ret) | |
369 | ret = mem_create_simple_file(mem, state); | |
370 | if (!ret) | |
371 | ret = mem_create_simple_file(mem, phys_device); | |
5c755e9f BP |
372 | if (!ret) |
373 | ret = mem_create_simple_file(mem, removable); | |
c04fc586 GH |
374 | if (!ret) { |
375 | if (context == HOTPLUG) | |
376 | ret = register_mem_sect_under_node(mem, nid); | |
377 | } | |
3947be19 DH |
378 | |
379 | return ret; | |
380 | } | |
381 | ||
382 | /* | |
383 | * For now, we have a linear search to go find the appropriate | |
384 | * memory_block corresponding to a particular phys_index. If | |
385 | * this gets to be a real problem, we can always use a radix | |
386 | * tree or something here. | |
387 | * | |
388 | * This could be made generic for all sysdev classes. | |
389 | */ | |
c04fc586 | 390 | struct memory_block *find_memory_block(struct mem_section *section) |
3947be19 DH |
391 | { |
392 | struct kobject *kobj; | |
393 | struct sys_device *sysdev; | |
394 | struct memory_block *mem; | |
395 | char name[sizeof(MEMORY_CLASS_NAME) + 9 + 1]; | |
396 | ||
397 | /* | |
398 | * This only works because we know that section == sysdev->id | |
399 | * slightly redundant with sysdev_register() | |
400 | */ | |
401 | sprintf(&name[0], "%s%d", MEMORY_CLASS_NAME, __section_nr(section)); | |
402 | ||
403 | kobj = kset_find_obj(&memory_sysdev_class.kset, name); | |
404 | if (!kobj) | |
405 | return NULL; | |
406 | ||
407 | sysdev = container_of(kobj, struct sys_device, kobj); | |
408 | mem = container_of(sysdev, struct memory_block, sysdev); | |
409 | ||
410 | return mem; | |
411 | } | |
412 | ||
413 | int remove_memory_block(unsigned long node_id, struct mem_section *section, | |
414 | int phys_device) | |
415 | { | |
416 | struct memory_block *mem; | |
417 | ||
418 | mem = find_memory_block(section); | |
c04fc586 | 419 | unregister_mem_sect_under_nodes(mem); |
3947be19 DH |
420 | mem_remove_simple_file(mem, phys_index); |
421 | mem_remove_simple_file(mem, state); | |
422 | mem_remove_simple_file(mem, phys_device); | |
5c755e9f | 423 | mem_remove_simple_file(mem, removable); |
00a41db5 | 424 | unregister_memory(mem, section); |
3947be19 DH |
425 | |
426 | return 0; | |
427 | } | |
428 | ||
429 | /* | |
430 | * need an interface for the VM to add new memory regions, | |
431 | * but without onlining it. | |
432 | */ | |
c04fc586 | 433 | int register_new_memory(int nid, struct mem_section *section) |
3947be19 | 434 | { |
c04fc586 | 435 | return add_memory_block(nid, section, MEM_OFFLINE, 0, HOTPLUG); |
3947be19 DH |
436 | } |
437 | ||
438 | int unregister_memory_section(struct mem_section *section) | |
439 | { | |
540557b9 | 440 | if (!present_section(section)) |
3947be19 DH |
441 | return -EINVAL; |
442 | ||
443 | return remove_memory_block(0, section, 0); | |
444 | } | |
445 | ||
446 | /* | |
447 | * Initialize the sysfs support for memory devices... | |
448 | */ | |
449 | int __init memory_dev_init(void) | |
450 | { | |
451 | unsigned int i; | |
452 | int ret; | |
28ec24e2 | 453 | int err; |
3947be19 | 454 | |
312c004d | 455 | memory_sysdev_class.kset.uevent_ops = &memory_uevent_ops; |
3947be19 | 456 | ret = sysdev_class_register(&memory_sysdev_class); |
28ec24e2 AM |
457 | if (ret) |
458 | goto out; | |
3947be19 DH |
459 | |
460 | /* | |
461 | * Create entries for memory sections that were found | |
462 | * during boot and have been initialized | |
463 | */ | |
464 | for (i = 0; i < NR_MEM_SECTIONS; i++) { | |
540557b9 | 465 | if (!present_section_nr(i)) |
3947be19 | 466 | continue; |
c04fc586 GH |
467 | err = add_memory_block(0, __nr_to_section(i), MEM_ONLINE, |
468 | 0, BOOT); | |
28ec24e2 AM |
469 | if (!ret) |
470 | ret = err; | |
3947be19 DH |
471 | } |
472 | ||
28ec24e2 AM |
473 | err = memory_probe_init(); |
474 | if (!ret) | |
475 | ret = err; | |
476 | err = block_size_init(); | |
477 | if (!ret) | |
478 | ret = err; | |
479 | out: | |
480 | if (ret) | |
2b3a302a | 481 | printk(KERN_ERR "%s() failed: %d\n", __func__, ret); |
3947be19 DH |
482 | return ret; |
483 | } |