ia64/kvm: compilation fix. export account_system_vtime.
[pv_ops_mirror.git] / drivers / base / memory.c
blob937e8258981db78be0b81303d63a8e7ebc30d692
1 /*
2 * drivers/base/memory.c - basic Memory class support
4 * Written by Matt Tolentino <matthew.e.tolentino@intel.com>
5 * Dave Hansen <haveblue@us.ibm.com>
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.
13 #include <linux/sysdev.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/topology.h>
17 #include <linux/capability.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 <linux/mutex.h>
24 #include <asm/atomic.h>
25 #include <asm/uaccess.h>
27 #define MEMORY_CLASS_NAME "memory"
29 static struct sysdev_class memory_sysdev_class = {
30 .name = MEMORY_CLASS_NAME,
33 static const char *memory_uevent_name(struct kset *kset, struct kobject *kobj)
35 return MEMORY_CLASS_NAME;
38 static int memory_uevent(struct kset *kset, struct kobject *obj, struct kobj_uevent_env *env)
40 int retval = 0;
42 return retval;
45 static struct kset_uevent_ops memory_uevent_ops = {
46 .name = memory_uevent_name,
47 .uevent = memory_uevent,
50 static BLOCKING_NOTIFIER_HEAD(memory_chain);
52 int register_memory_notifier(struct notifier_block *nb)
54 return blocking_notifier_chain_register(&memory_chain, nb);
56 EXPORT_SYMBOL(register_memory_notifier);
58 void unregister_memory_notifier(struct notifier_block *nb)
60 blocking_notifier_chain_unregister(&memory_chain, nb);
62 EXPORT_SYMBOL(unregister_memory_notifier);
65 * register_memory - Setup a sysfs device for a memory block
67 static
68 int register_memory(struct memory_block *memory, struct mem_section *section)
70 int error;
72 memory->sysdev.cls = &memory_sysdev_class;
73 memory->sysdev.id = __section_nr(section);
75 error = sysdev_register(&memory->sysdev);
76 return error;
79 static void
80 unregister_memory(struct memory_block *memory, struct mem_section *section)
82 BUG_ON(memory->sysdev.cls != &memory_sysdev_class);
83 BUG_ON(memory->sysdev.id != __section_nr(section));
85 /* drop the ref. we got in remove_memory_block() */
86 kobject_put(&memory->sysdev.kobj);
87 sysdev_unregister(&memory->sysdev);
91 * use this as the physical section index that this memsection
92 * uses.
95 static ssize_t show_mem_phys_index(struct sys_device *dev, char *buf)
97 struct memory_block *mem =
98 container_of(dev, struct memory_block, sysdev);
99 return sprintf(buf, "%08lx\n", mem->phys_index);
103 * online, offline, going offline, etc.
105 static ssize_t show_mem_state(struct sys_device *dev, char *buf)
107 struct memory_block *mem =
108 container_of(dev, struct memory_block, sysdev);
109 ssize_t len = 0;
112 * We can probably put these states in a nice little array
113 * so that they're not open-coded
115 switch (mem->state) {
116 case MEM_ONLINE:
117 len = sprintf(buf, "online\n");
118 break;
119 case MEM_OFFLINE:
120 len = sprintf(buf, "offline\n");
121 break;
122 case MEM_GOING_OFFLINE:
123 len = sprintf(buf, "going-offline\n");
124 break;
125 default:
126 len = sprintf(buf, "ERROR-UNKNOWN-%ld\n",
127 mem->state);
128 WARN_ON(1);
129 break;
132 return len;
135 int memory_notify(unsigned long val, void *v)
137 return blocking_notifier_call_chain(&memory_chain, val, v);
141 * MEMORY_HOTPLUG depends on SPARSEMEM in mm/Kconfig, so it is
142 * OK to have direct references to sparsemem variables in here.
144 static int
145 memory_block_action(struct memory_block *mem, unsigned long action)
147 int i;
148 unsigned long psection;
149 unsigned long start_pfn, start_paddr;
150 struct page *first_page;
151 int ret;
152 int old_state = mem->state;
154 psection = mem->phys_index;
155 first_page = pfn_to_page(psection << PFN_SECTION_SHIFT);
158 * The probe routines leave the pages reserved, just
159 * as the bootmem code does. Make sure they're still
160 * that way.
162 if (action == MEM_ONLINE) {
163 for (i = 0; i < PAGES_PER_SECTION; i++) {
164 if (PageReserved(first_page+i))
165 continue;
167 printk(KERN_WARNING "section number %ld page number %d "
168 "not reserved, was it already online? \n",
169 psection, i);
170 return -EBUSY;
174 switch (action) {
175 case MEM_ONLINE:
176 start_pfn = page_to_pfn(first_page);
177 ret = online_pages(start_pfn, PAGES_PER_SECTION);
178 break;
179 case MEM_OFFLINE:
180 mem->state = MEM_GOING_OFFLINE;
181 start_paddr = page_to_pfn(first_page) << PAGE_SHIFT;
182 ret = remove_memory(start_paddr,
183 PAGES_PER_SECTION << PAGE_SHIFT);
184 if (ret) {
185 mem->state = old_state;
186 break;
188 break;
189 default:
190 printk(KERN_WARNING "%s(%p, %ld) unknown action: %ld\n",
191 __func__, mem, action, action);
192 WARN_ON(1);
193 ret = -EINVAL;
196 return ret;
199 static int memory_block_change_state(struct memory_block *mem,
200 unsigned long to_state, unsigned long from_state_req)
202 int ret = 0;
203 mutex_lock(&mem->state_mutex);
205 if (mem->state != from_state_req) {
206 ret = -EINVAL;
207 goto out;
210 ret = memory_block_action(mem, to_state);
211 if (!ret)
212 mem->state = to_state;
214 out:
215 mutex_unlock(&mem->state_mutex);
216 return ret;
219 static ssize_t
220 store_mem_state(struct sys_device *dev, const char *buf, size_t count)
222 struct memory_block *mem;
223 unsigned int phys_section_nr;
224 int ret = -EINVAL;
226 mem = container_of(dev, struct memory_block, sysdev);
227 phys_section_nr = mem->phys_index;
229 if (!present_section_nr(phys_section_nr))
230 goto out;
232 if (!strncmp(buf, "online", min((int)count, 6)))
233 ret = memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE);
234 else if(!strncmp(buf, "offline", min((int)count, 7)))
235 ret = memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE);
236 out:
237 if (ret)
238 return ret;
239 return count;
243 * phys_device is a bad name for this. What I really want
244 * is a way to differentiate between memory ranges that
245 * are part of physical devices that constitute
246 * a complete removable unit or fru.
247 * i.e. do these ranges belong to the same physical device,
248 * s.t. if I offline all of these sections I can then
249 * remove the physical device?
251 static ssize_t show_phys_device(struct sys_device *dev, char *buf)
253 struct memory_block *mem =
254 container_of(dev, struct memory_block, sysdev);
255 return sprintf(buf, "%d\n", mem->phys_device);
258 static SYSDEV_ATTR(phys_index, 0444, show_mem_phys_index, NULL);
259 static SYSDEV_ATTR(state, 0644, show_mem_state, store_mem_state);
260 static SYSDEV_ATTR(phys_device, 0444, show_phys_device, NULL);
262 #define mem_create_simple_file(mem, attr_name) \
263 sysdev_create_file(&mem->sysdev, &attr_##attr_name)
264 #define mem_remove_simple_file(mem, attr_name) \
265 sysdev_remove_file(&mem->sysdev, &attr_##attr_name)
268 * Block size attribute stuff
270 static ssize_t
271 print_block_size(struct class *class, char *buf)
273 return sprintf(buf, "%lx\n", (unsigned long)PAGES_PER_SECTION * PAGE_SIZE);
276 static CLASS_ATTR(block_size_bytes, 0444, print_block_size, NULL);
278 static int block_size_init(void)
280 return sysfs_create_file(&memory_sysdev_class.kset.kobj,
281 &class_attr_block_size_bytes.attr);
285 * Some architectures will have custom drivers to do this, and
286 * will not need to do it from userspace. The fake hot-add code
287 * as well as ppc64 will do all of their discovery in userspace
288 * and will require this interface.
290 #ifdef CONFIG_ARCH_MEMORY_PROBE
291 static ssize_t
292 memory_probe_store(struct class *class, const char *buf, size_t count)
294 u64 phys_addr;
295 int nid;
296 int ret;
298 phys_addr = simple_strtoull(buf, NULL, 0);
300 nid = memory_add_physaddr_to_nid(phys_addr);
301 ret = add_memory(nid, phys_addr, PAGES_PER_SECTION << PAGE_SHIFT);
303 if (ret)
304 count = ret;
306 return count;
308 static CLASS_ATTR(probe, 0700, NULL, memory_probe_store);
310 static int memory_probe_init(void)
312 return sysfs_create_file(&memory_sysdev_class.kset.kobj,
313 &class_attr_probe.attr);
315 #else
316 static inline int memory_probe_init(void)
318 return 0;
320 #endif
323 * Note that phys_device is optional. It is here to allow for
324 * differentiation between which *physical* devices each
325 * section belongs to...
328 static int add_memory_block(unsigned long node_id, struct mem_section *section,
329 unsigned long state, int phys_device)
331 struct memory_block *mem = kzalloc(sizeof(*mem), GFP_KERNEL);
332 int ret = 0;
334 if (!mem)
335 return -ENOMEM;
337 mem->phys_index = __section_nr(section);
338 mem->state = state;
339 mutex_init(&mem->state_mutex);
340 mem->phys_device = phys_device;
342 ret = register_memory(mem, section);
343 if (!ret)
344 ret = mem_create_simple_file(mem, phys_index);
345 if (!ret)
346 ret = mem_create_simple_file(mem, state);
347 if (!ret)
348 ret = mem_create_simple_file(mem, phys_device);
350 return ret;
354 * For now, we have a linear search to go find the appropriate
355 * memory_block corresponding to a particular phys_index. If
356 * this gets to be a real problem, we can always use a radix
357 * tree or something here.
359 * This could be made generic for all sysdev classes.
361 static struct memory_block *find_memory_block(struct mem_section *section)
363 struct kobject *kobj;
364 struct sys_device *sysdev;
365 struct memory_block *mem;
366 char name[sizeof(MEMORY_CLASS_NAME) + 9 + 1];
369 * This only works because we know that section == sysdev->id
370 * slightly redundant with sysdev_register()
372 sprintf(&name[0], "%s%d", MEMORY_CLASS_NAME, __section_nr(section));
374 kobj = kset_find_obj(&memory_sysdev_class.kset, name);
375 if (!kobj)
376 return NULL;
378 sysdev = container_of(kobj, struct sys_device, kobj);
379 mem = container_of(sysdev, struct memory_block, sysdev);
381 return mem;
384 int remove_memory_block(unsigned long node_id, struct mem_section *section,
385 int phys_device)
387 struct memory_block *mem;
389 mem = find_memory_block(section);
390 mem_remove_simple_file(mem, phys_index);
391 mem_remove_simple_file(mem, state);
392 mem_remove_simple_file(mem, phys_device);
393 unregister_memory(mem, section);
395 return 0;
399 * need an interface for the VM to add new memory regions,
400 * but without onlining it.
402 int register_new_memory(struct mem_section *section)
404 return add_memory_block(0, section, MEM_OFFLINE, 0);
407 int unregister_memory_section(struct mem_section *section)
409 if (!present_section(section))
410 return -EINVAL;
412 return remove_memory_block(0, section, 0);
416 * Initialize the sysfs support for memory devices...
418 int __init memory_dev_init(void)
420 unsigned int i;
421 int ret;
422 int err;
424 memory_sysdev_class.kset.uevent_ops = &memory_uevent_ops;
425 ret = sysdev_class_register(&memory_sysdev_class);
426 if (ret)
427 goto out;
430 * Create entries for memory sections that were found
431 * during boot and have been initialized
433 for (i = 0; i < NR_MEM_SECTIONS; i++) {
434 if (!present_section_nr(i))
435 continue;
436 err = add_memory_block(0, __nr_to_section(i), MEM_ONLINE, 0);
437 if (!ret)
438 ret = err;
441 err = memory_probe_init();
442 if (!ret)
443 ret = err;
444 err = block_size_init();
445 if (!ret)
446 ret = err;
447 out:
448 if (ret)
449 printk(KERN_ERR "%s() failed: %d\n", __func__, ret);
450 return ret;