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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> | |
23 | #include <asm/atomic.h> | |
24 | #include <asm/uaccess.h> | |
25 | ||
26 | #define MEMORY_CLASS_NAME "memory" | |
27 | ||
28 | static struct sysdev_class memory_sysdev_class = { | |
af5ca3f4 | 29 | .name = MEMORY_CLASS_NAME, |
3947be19 | 30 | }; |
3947be19 | 31 | |
312c004d | 32 | static const char *memory_uevent_name(struct kset *kset, struct kobject *kobj) |
3947be19 DH |
33 | { |
34 | return MEMORY_CLASS_NAME; | |
35 | } | |
36 | ||
9ec0fd4e | 37 | static int memory_uevent(struct kset *kset, struct kobject *obj, struct kobj_uevent_env *env) |
3947be19 DH |
38 | { |
39 | int retval = 0; | |
40 | ||
41 | return retval; | |
42 | } | |
43 | ||
312c004d KS |
44 | static struct kset_uevent_ops memory_uevent_ops = { |
45 | .name = memory_uevent_name, | |
46 | .uevent = memory_uevent, | |
3947be19 DH |
47 | }; |
48 | ||
e041c683 | 49 | static BLOCKING_NOTIFIER_HEAD(memory_chain); |
3947be19 | 50 | |
98a38ebd | 51 | int register_memory_notifier(struct notifier_block *nb) |
3947be19 | 52 | { |
e041c683 | 53 | return blocking_notifier_chain_register(&memory_chain, nb); |
3947be19 DH |
54 | } |
55 | ||
98a38ebd | 56 | void unregister_memory_notifier(struct notifier_block *nb) |
3947be19 | 57 | { |
e041c683 | 58 | blocking_notifier_chain_unregister(&memory_chain, nb); |
3947be19 DH |
59 | } |
60 | ||
61 | /* | |
62 | * register_memory - Setup a sysfs device for a memory block | |
63 | */ | |
900b2b46 | 64 | int register_memory(struct memory_block *memory, struct mem_section *section, |
3947be19 DH |
65 | struct node *root) |
66 | { | |
67 | int error; | |
68 | ||
69 | memory->sysdev.cls = &memory_sysdev_class; | |
70 | memory->sysdev.id = __section_nr(section); | |
71 | ||
72 | error = sysdev_register(&memory->sysdev); | |
73 | ||
74 | if (root && !error) | |
75 | error = sysfs_create_link(&root->sysdev.kobj, | |
76 | &memory->sysdev.kobj, | |
77 | kobject_name(&memory->sysdev.kobj)); | |
78 | ||
79 | return error; | |
80 | } | |
81 | ||
82 | static void | |
83 | unregister_memory(struct memory_block *memory, struct mem_section *section, | |
84 | struct node *root) | |
85 | { | |
86 | BUG_ON(memory->sysdev.cls != &memory_sysdev_class); | |
87 | BUG_ON(memory->sysdev.id != __section_nr(section)); | |
88 | ||
89 | sysdev_unregister(&memory->sysdev); | |
90 | if (root) | |
91 | sysfs_remove_link(&root->sysdev.kobj, | |
92 | kobject_name(&memory->sysdev.kobj)); | |
93 | } | |
94 | ||
95 | /* | |
96 | * use this as the physical section index that this memsection | |
97 | * uses. | |
98 | */ | |
99 | ||
100 | static ssize_t show_mem_phys_index(struct sys_device *dev, char *buf) | |
101 | { | |
102 | struct memory_block *mem = | |
103 | container_of(dev, struct memory_block, sysdev); | |
104 | return sprintf(buf, "%08lx\n", mem->phys_index); | |
105 | } | |
106 | ||
107 | /* | |
108 | * online, offline, going offline, etc. | |
109 | */ | |
110 | static ssize_t show_mem_state(struct sys_device *dev, char *buf) | |
111 | { | |
112 | struct memory_block *mem = | |
113 | container_of(dev, struct memory_block, sysdev); | |
114 | ssize_t len = 0; | |
115 | ||
116 | /* | |
117 | * We can probably put these states in a nice little array | |
118 | * so that they're not open-coded | |
119 | */ | |
120 | switch (mem->state) { | |
121 | case MEM_ONLINE: | |
122 | len = sprintf(buf, "online\n"); | |
123 | break; | |
124 | case MEM_OFFLINE: | |
125 | len = sprintf(buf, "offline\n"); | |
126 | break; | |
127 | case MEM_GOING_OFFLINE: | |
128 | len = sprintf(buf, "going-offline\n"); | |
129 | break; | |
130 | default: | |
131 | len = sprintf(buf, "ERROR-UNKNOWN-%ld\n", | |
132 | mem->state); | |
133 | WARN_ON(1); | |
134 | break; | |
135 | } | |
136 | ||
137 | return len; | |
138 | } | |
139 | ||
7b78d335 | 140 | int memory_notify(unsigned long val, void *v) |
3947be19 | 141 | { |
e041c683 | 142 | return blocking_notifier_call_chain(&memory_chain, val, v); |
3947be19 DH |
143 | } |
144 | ||
145 | /* | |
146 | * MEMORY_HOTPLUG depends on SPARSEMEM in mm/Kconfig, so it is | |
147 | * OK to have direct references to sparsemem variables in here. | |
148 | */ | |
149 | static int | |
150 | memory_block_action(struct memory_block *mem, unsigned long action) | |
151 | { | |
152 | int i; | |
153 | unsigned long psection; | |
154 | unsigned long start_pfn, start_paddr; | |
155 | struct page *first_page; | |
156 | int ret; | |
157 | int old_state = mem->state; | |
158 | ||
159 | psection = mem->phys_index; | |
160 | first_page = pfn_to_page(psection << PFN_SECTION_SHIFT); | |
161 | ||
162 | /* | |
163 | * The probe routines leave the pages reserved, just | |
164 | * as the bootmem code does. Make sure they're still | |
165 | * that way. | |
166 | */ | |
167 | if (action == MEM_ONLINE) { | |
168 | for (i = 0; i < PAGES_PER_SECTION; i++) { | |
169 | if (PageReserved(first_page+i)) | |
170 | continue; | |
171 | ||
172 | printk(KERN_WARNING "section number %ld page number %d " | |
173 | "not reserved, was it already online? \n", | |
174 | psection, i); | |
175 | return -EBUSY; | |
176 | } | |
177 | } | |
178 | ||
179 | switch (action) { | |
180 | case MEM_ONLINE: | |
181 | start_pfn = page_to_pfn(first_page); | |
182 | ret = online_pages(start_pfn, PAGES_PER_SECTION); | |
183 | break; | |
184 | case MEM_OFFLINE: | |
185 | mem->state = MEM_GOING_OFFLINE; | |
3947be19 DH |
186 | start_paddr = page_to_pfn(first_page) << PAGE_SHIFT; |
187 | ret = remove_memory(start_paddr, | |
188 | PAGES_PER_SECTION << PAGE_SHIFT); | |
189 | if (ret) { | |
190 | mem->state = old_state; | |
191 | break; | |
192 | } | |
3947be19 DH |
193 | break; |
194 | default: | |
195 | printk(KERN_WARNING "%s(%p, %ld) unknown action: %ld\n", | |
196 | __FUNCTION__, mem, action, action); | |
197 | WARN_ON(1); | |
198 | ret = -EINVAL; | |
199 | } | |
3947be19 DH |
200 | |
201 | return ret; | |
202 | } | |
203 | ||
204 | static int memory_block_change_state(struct memory_block *mem, | |
205 | unsigned long to_state, unsigned long from_state_req) | |
206 | { | |
207 | int ret = 0; | |
208 | down(&mem->state_sem); | |
209 | ||
210 | if (mem->state != from_state_req) { | |
211 | ret = -EINVAL; | |
212 | goto out; | |
213 | } | |
214 | ||
215 | ret = memory_block_action(mem, to_state); | |
216 | if (!ret) | |
217 | mem->state = to_state; | |
218 | ||
219 | out: | |
220 | up(&mem->state_sem); | |
221 | return ret; | |
222 | } | |
223 | ||
224 | static ssize_t | |
225 | store_mem_state(struct sys_device *dev, const char *buf, size_t count) | |
226 | { | |
227 | struct memory_block *mem; | |
228 | unsigned int phys_section_nr; | |
229 | int ret = -EINVAL; | |
230 | ||
231 | mem = container_of(dev, struct memory_block, sysdev); | |
232 | phys_section_nr = mem->phys_index; | |
233 | ||
540557b9 | 234 | if (!present_section_nr(phys_section_nr)) |
3947be19 DH |
235 | goto out; |
236 | ||
237 | if (!strncmp(buf, "online", min((int)count, 6))) | |
238 | ret = memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE); | |
239 | else if(!strncmp(buf, "offline", min((int)count, 7))) | |
240 | ret = memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE); | |
241 | out: | |
242 | if (ret) | |
243 | return ret; | |
244 | return count; | |
245 | } | |
246 | ||
247 | /* | |
248 | * phys_device is a bad name for this. What I really want | |
249 | * is a way to differentiate between memory ranges that | |
250 | * are part of physical devices that constitute | |
251 | * a complete removable unit or fru. | |
252 | * i.e. do these ranges belong to the same physical device, | |
253 | * s.t. if I offline all of these sections I can then | |
254 | * remove the physical device? | |
255 | */ | |
256 | static ssize_t show_phys_device(struct sys_device *dev, char *buf) | |
257 | { | |
258 | struct memory_block *mem = | |
259 | container_of(dev, struct memory_block, sysdev); | |
260 | return sprintf(buf, "%d\n", mem->phys_device); | |
261 | } | |
262 | ||
263 | static SYSDEV_ATTR(phys_index, 0444, show_mem_phys_index, NULL); | |
264 | static SYSDEV_ATTR(state, 0644, show_mem_state, store_mem_state); | |
265 | static SYSDEV_ATTR(phys_device, 0444, show_phys_device, NULL); | |
266 | ||
267 | #define mem_create_simple_file(mem, attr_name) \ | |
268 | sysdev_create_file(&mem->sysdev, &attr_##attr_name) | |
269 | #define mem_remove_simple_file(mem, attr_name) \ | |
270 | sysdev_remove_file(&mem->sysdev, &attr_##attr_name) | |
271 | ||
272 | /* | |
273 | * Block size attribute stuff | |
274 | */ | |
275 | static ssize_t | |
276 | print_block_size(struct class *class, char *buf) | |
277 | { | |
278 | return sprintf(buf, "%lx\n", (unsigned long)PAGES_PER_SECTION * PAGE_SIZE); | |
279 | } | |
280 | ||
281 | static CLASS_ATTR(block_size_bytes, 0444, print_block_size, NULL); | |
282 | ||
283 | static int block_size_init(void) | |
284 | { | |
28ec24e2 AM |
285 | return sysfs_create_file(&memory_sysdev_class.kset.kobj, |
286 | &class_attr_block_size_bytes.attr); | |
3947be19 DH |
287 | } |
288 | ||
289 | /* | |
290 | * Some architectures will have custom drivers to do this, and | |
291 | * will not need to do it from userspace. The fake hot-add code | |
292 | * as well as ppc64 will do all of their discovery in userspace | |
293 | * and will require this interface. | |
294 | */ | |
295 | #ifdef CONFIG_ARCH_MEMORY_PROBE | |
296 | static ssize_t | |
be7ee9b2 | 297 | memory_probe_store(struct class *class, const char *buf, size_t count) |
3947be19 DH |
298 | { |
299 | u64 phys_addr; | |
bc02af93 | 300 | int nid; |
3947be19 DH |
301 | int ret; |
302 | ||
303 | phys_addr = simple_strtoull(buf, NULL, 0); | |
304 | ||
bc02af93 YG |
305 | nid = memory_add_physaddr_to_nid(phys_addr); |
306 | ret = add_memory(nid, phys_addr, PAGES_PER_SECTION << PAGE_SHIFT); | |
3947be19 DH |
307 | |
308 | if (ret) | |
309 | count = ret; | |
310 | ||
311 | return count; | |
312 | } | |
313 | static CLASS_ATTR(probe, 0700, NULL, memory_probe_store); | |
314 | ||
315 | static int memory_probe_init(void) | |
316 | { | |
28ec24e2 AM |
317 | return sysfs_create_file(&memory_sysdev_class.kset.kobj, |
318 | &class_attr_probe.attr); | |
3947be19 DH |
319 | } |
320 | #else | |
28ec24e2 AM |
321 | static inline int memory_probe_init(void) |
322 | { | |
323 | return 0; | |
324 | } | |
3947be19 DH |
325 | #endif |
326 | ||
327 | /* | |
328 | * Note that phys_device is optional. It is here to allow for | |
329 | * differentiation between which *physical* devices each | |
330 | * section belongs to... | |
331 | */ | |
332 | ||
333 | static int add_memory_block(unsigned long node_id, struct mem_section *section, | |
334 | unsigned long state, int phys_device) | |
335 | { | |
0b0acbec | 336 | struct memory_block *mem = kzalloc(sizeof(*mem), GFP_KERNEL); |
3947be19 DH |
337 | int ret = 0; |
338 | ||
339 | if (!mem) | |
340 | return -ENOMEM; | |
341 | ||
3947be19 DH |
342 | mem->phys_index = __section_nr(section); |
343 | mem->state = state; | |
344 | init_MUTEX(&mem->state_sem); | |
345 | mem->phys_device = phys_device; | |
346 | ||
347 | ret = register_memory(mem, section, NULL); | |
348 | if (!ret) | |
349 | ret = mem_create_simple_file(mem, phys_index); | |
350 | if (!ret) | |
351 | ret = mem_create_simple_file(mem, state); | |
352 | if (!ret) | |
353 | ret = mem_create_simple_file(mem, phys_device); | |
354 | ||
355 | return ret; | |
356 | } | |
357 | ||
358 | /* | |
359 | * For now, we have a linear search to go find the appropriate | |
360 | * memory_block corresponding to a particular phys_index. If | |
361 | * this gets to be a real problem, we can always use a radix | |
362 | * tree or something here. | |
363 | * | |
364 | * This could be made generic for all sysdev classes. | |
365 | */ | |
366 | static struct memory_block *find_memory_block(struct mem_section *section) | |
367 | { | |
368 | struct kobject *kobj; | |
369 | struct sys_device *sysdev; | |
370 | struct memory_block *mem; | |
371 | char name[sizeof(MEMORY_CLASS_NAME) + 9 + 1]; | |
372 | ||
373 | /* | |
374 | * This only works because we know that section == sysdev->id | |
375 | * slightly redundant with sysdev_register() | |
376 | */ | |
377 | sprintf(&name[0], "%s%d", MEMORY_CLASS_NAME, __section_nr(section)); | |
378 | ||
379 | kobj = kset_find_obj(&memory_sysdev_class.kset, name); | |
380 | if (!kobj) | |
381 | return NULL; | |
382 | ||
383 | sysdev = container_of(kobj, struct sys_device, kobj); | |
384 | mem = container_of(sysdev, struct memory_block, sysdev); | |
385 | ||
386 | return mem; | |
387 | } | |
388 | ||
389 | int remove_memory_block(unsigned long node_id, struct mem_section *section, | |
390 | int phys_device) | |
391 | { | |
392 | struct memory_block *mem; | |
393 | ||
394 | mem = find_memory_block(section); | |
395 | mem_remove_simple_file(mem, phys_index); | |
396 | mem_remove_simple_file(mem, state); | |
397 | mem_remove_simple_file(mem, phys_device); | |
398 | unregister_memory(mem, section, NULL); | |
399 | ||
400 | return 0; | |
401 | } | |
402 | ||
403 | /* | |
404 | * need an interface for the VM to add new memory regions, | |
405 | * but without onlining it. | |
406 | */ | |
407 | int register_new_memory(struct mem_section *section) | |
408 | { | |
409 | return add_memory_block(0, section, MEM_OFFLINE, 0); | |
410 | } | |
411 | ||
412 | int unregister_memory_section(struct mem_section *section) | |
413 | { | |
540557b9 | 414 | if (!present_section(section)) |
3947be19 DH |
415 | return -EINVAL; |
416 | ||
417 | return remove_memory_block(0, section, 0); | |
418 | } | |
419 | ||
420 | /* | |
421 | * Initialize the sysfs support for memory devices... | |
422 | */ | |
423 | int __init memory_dev_init(void) | |
424 | { | |
425 | unsigned int i; | |
426 | int ret; | |
28ec24e2 | 427 | int err; |
3947be19 | 428 | |
312c004d | 429 | memory_sysdev_class.kset.uevent_ops = &memory_uevent_ops; |
3947be19 | 430 | ret = sysdev_class_register(&memory_sysdev_class); |
28ec24e2 AM |
431 | if (ret) |
432 | goto out; | |
3947be19 DH |
433 | |
434 | /* | |
435 | * Create entries for memory sections that were found | |
436 | * during boot and have been initialized | |
437 | */ | |
438 | for (i = 0; i < NR_MEM_SECTIONS; i++) { | |
540557b9 | 439 | if (!present_section_nr(i)) |
3947be19 | 440 | continue; |
28ec24e2 AM |
441 | err = add_memory_block(0, __nr_to_section(i), MEM_ONLINE, 0); |
442 | if (!ret) | |
443 | ret = err; | |
3947be19 DH |
444 | } |
445 | ||
28ec24e2 AM |
446 | err = memory_probe_init(); |
447 | if (!ret) | |
448 | ret = err; | |
449 | err = block_size_init(); | |
450 | if (!ret) | |
451 | ret = err; | |
452 | out: | |
453 | if (ret) | |
454 | printk(KERN_ERR "%s() failed: %d\n", __FUNCTION__, ret); | |
3947be19 DH |
455 | return ret; |
456 | } |