blob: 7ae413fdd5fc4bd1f0d1b0941316df52dbe8e11f [file] [log] [blame]
Dave Hansen3947be12005-10-29 18:16:54 -07001/*
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>
Dave Hansen3947be12005-10-29 18:16:54 -070016#include <linux/topology.h>
Randy.Dunlapc59ede72006-01-11 12:17:46 -080017#include <linux/capability.h>
Dave Hansen3947be12005-10-29 18:16:54 -070018#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
28static struct sysdev_class memory_sysdev_class = {
Kay Sieversaf5ca3f2007-12-20 02:09:39 +010029 .name = MEMORY_CLASS_NAME,
Dave Hansen3947be12005-10-29 18:16:54 -070030};
Dave Hansen3947be12005-10-29 18:16:54 -070031
Kay Sievers312c0042005-11-16 09:00:00 +010032static const char *memory_uevent_name(struct kset *kset, struct kobject *kobj)
Dave Hansen3947be12005-10-29 18:16:54 -070033{
34 return MEMORY_CLASS_NAME;
35}
36
Al Viro9ec0fd4e2007-10-14 06:53:45 +010037static int memory_uevent(struct kset *kset, struct kobject *obj, struct kobj_uevent_env *env)
Dave Hansen3947be12005-10-29 18:16:54 -070038{
39 int retval = 0;
40
41 return retval;
42}
43
Kay Sievers312c0042005-11-16 09:00:00 +010044static struct kset_uevent_ops memory_uevent_ops = {
45 .name = memory_uevent_name,
46 .uevent = memory_uevent,
Dave Hansen3947be12005-10-29 18:16:54 -070047};
48
Alan Sterne041c682006-03-27 01:16:30 -080049static BLOCKING_NOTIFIER_HEAD(memory_chain);
Dave Hansen3947be12005-10-29 18:16:54 -070050
Andy Whitcroft98a38eb2006-01-06 00:10:35 -080051int register_memory_notifier(struct notifier_block *nb)
Dave Hansen3947be12005-10-29 18:16:54 -070052{
Alan Sterne041c682006-03-27 01:16:30 -080053 return blocking_notifier_chain_register(&memory_chain, nb);
Dave Hansen3947be12005-10-29 18:16:54 -070054}
55
Andy Whitcroft98a38eb2006-01-06 00:10:35 -080056void unregister_memory_notifier(struct notifier_block *nb)
Dave Hansen3947be12005-10-29 18:16:54 -070057{
Alan Sterne041c682006-03-27 01:16:30 -080058 blocking_notifier_chain_unregister(&memory_chain, nb);
Dave Hansen3947be12005-10-29 18:16:54 -070059}
60
61/*
62 * register_memory - Setup a sysfs device for a memory block
63 */
Andy Whitcroft900b2b42006-01-06 00:10:35 -080064int register_memory(struct memory_block *memory, struct mem_section *section,
Dave Hansen3947be12005-10-29 18:16:54 -070065 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
82static void
83unregister_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
100static 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 */
110static 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
Yasunori Goto7b78d332007-10-21 16:41:36 -0700140int memory_notify(unsigned long val, void *v)
Dave Hansen3947be12005-10-29 18:16:54 -0700141{
Alan Sterne041c682006-03-27 01:16:30 -0800142 return blocking_notifier_call_chain(&memory_chain, val, v);
Dave Hansen3947be12005-10-29 18:16:54 -0700143}
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 */
149static int
150memory_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;
Dave Hansen3947be12005-10-29 18:16:54 -0700186 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 }
Dave Hansen3947be12005-10-29 18:16:54 -0700193 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 }
Dave Hansen3947be12005-10-29 18:16:54 -0700200
201 return ret;
202}
203
204static 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
219out:
220 up(&mem->state_sem);
221 return ret;
222}
223
224static ssize_t
225store_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
Andy Whitcroft540557b2007-10-16 01:24:11 -0700234 if (!present_section_nr(phys_section_nr))
Dave Hansen3947be12005-10-29 18:16:54 -0700235 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);
241out:
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 */
256static 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
263static SYSDEV_ATTR(phys_index, 0444, show_mem_phys_index, NULL);
264static SYSDEV_ATTR(state, 0644, show_mem_state, store_mem_state);
265static 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 */
275static ssize_t
276print_block_size(struct class *class, char *buf)
277{
278 return sprintf(buf, "%lx\n", (unsigned long)PAGES_PER_SECTION * PAGE_SIZE);
279}
280
281static CLASS_ATTR(block_size_bytes, 0444, print_block_size, NULL);
282
283static int block_size_init(void)
284{
Andrew Morton28ec24e2006-12-06 20:37:29 -0800285 return sysfs_create_file(&memory_sysdev_class.kset.kobj,
286 &class_attr_block_size_bytes.attr);
Dave Hansen3947be12005-10-29 18:16:54 -0700287}
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
296static ssize_t
Al Virobe7ee9b2006-02-01 06:06:16 -0500297memory_probe_store(struct class *class, const char *buf, size_t count)
Dave Hansen3947be12005-10-29 18:16:54 -0700298{
299 u64 phys_addr;
Yasunori Gotobc02af92006-06-27 02:53:30 -0700300 int nid;
Dave Hansen3947be12005-10-29 18:16:54 -0700301 int ret;
302
303 phys_addr = simple_strtoull(buf, NULL, 0);
304
Yasunori Gotobc02af92006-06-27 02:53:30 -0700305 nid = memory_add_physaddr_to_nid(phys_addr);
306 ret = add_memory(nid, phys_addr, PAGES_PER_SECTION << PAGE_SHIFT);
Dave Hansen3947be12005-10-29 18:16:54 -0700307
308 if (ret)
309 count = ret;
310
311 return count;
312}
313static CLASS_ATTR(probe, 0700, NULL, memory_probe_store);
314
315static int memory_probe_init(void)
316{
Andrew Morton28ec24e2006-12-06 20:37:29 -0800317 return sysfs_create_file(&memory_sysdev_class.kset.kobj,
318 &class_attr_probe.attr);
Dave Hansen3947be12005-10-29 18:16:54 -0700319}
320#else
Andrew Morton28ec24e2006-12-06 20:37:29 -0800321static inline int memory_probe_init(void)
322{
323 return 0;
324}
Dave Hansen3947be12005-10-29 18:16:54 -0700325#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
333static int add_memory_block(unsigned long node_id, struct mem_section *section,
334 unsigned long state, int phys_device)
335{
Dave Hansen0b0acbe2005-10-29 18:16:55 -0700336 struct memory_block *mem = kzalloc(sizeof(*mem), GFP_KERNEL);
Dave Hansen3947be12005-10-29 18:16:54 -0700337 int ret = 0;
338
339 if (!mem)
340 return -ENOMEM;
341
Dave Hansen3947be12005-10-29 18:16:54 -0700342 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 */
366static 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
389int 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 */
407int register_new_memory(struct mem_section *section)
408{
409 return add_memory_block(0, section, MEM_OFFLINE, 0);
410}
411
412int unregister_memory_section(struct mem_section *section)
413{
Andy Whitcroft540557b2007-10-16 01:24:11 -0700414 if (!present_section(section))
Dave Hansen3947be12005-10-29 18:16:54 -0700415 return -EINVAL;
416
417 return remove_memory_block(0, section, 0);
418}
419
420/*
421 * Initialize the sysfs support for memory devices...
422 */
423int __init memory_dev_init(void)
424{
425 unsigned int i;
426 int ret;
Andrew Morton28ec24e2006-12-06 20:37:29 -0800427 int err;
Dave Hansen3947be12005-10-29 18:16:54 -0700428
Kay Sievers312c0042005-11-16 09:00:00 +0100429 memory_sysdev_class.kset.uevent_ops = &memory_uevent_ops;
Dave Hansen3947be12005-10-29 18:16:54 -0700430 ret = sysdev_class_register(&memory_sysdev_class);
Andrew Morton28ec24e2006-12-06 20:37:29 -0800431 if (ret)
432 goto out;
Dave Hansen3947be12005-10-29 18:16:54 -0700433
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++) {
Andy Whitcroft540557b2007-10-16 01:24:11 -0700439 if (!present_section_nr(i))
Dave Hansen3947be12005-10-29 18:16:54 -0700440 continue;
Andrew Morton28ec24e2006-12-06 20:37:29 -0800441 err = add_memory_block(0, __nr_to_section(i), MEM_ONLINE, 0);
442 if (!ret)
443 ret = err;
Dave Hansen3947be12005-10-29 18:16:54 -0700444 }
445
Andrew Morton28ec24e2006-12-06 20:37:29 -0800446 err = memory_probe_init();
447 if (!ret)
448 ret = err;
449 err = block_size_init();
450 if (!ret)
451 ret = err;
452out:
453 if (ret)
454 printk(KERN_ERR "%s() failed: %d\n", __FUNCTION__, ret);
Dave Hansen3947be12005-10-29 18:16:54 -0700455 return ret;
456}