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