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