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28#include <linux/kernel.h>
29#include <linux/module.h>
30#include <linux/init.h>
31#include <linux/types.h>
32#include <linux/memory_hotplug.h>
33#include <linux/slab.h>
34#include <acpi/acpi_drivers.h>
35
36#define ACPI_MEMORY_DEVICE_CLASS "memory"
37#define ACPI_MEMORY_DEVICE_HID "PNP0C80"
38#define ACPI_MEMORY_DEVICE_NAME "Hotplug Mem Device"
39
40#define _COMPONENT ACPI_MEMORY_DEVICE_COMPONENT
41
42#undef PREFIX
43#define PREFIX "ACPI:memory_hp:"
44
45ACPI_MODULE_NAME("acpi_memhotplug");
46MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>");
47MODULE_DESCRIPTION("Hotplug Mem Driver");
48MODULE_LICENSE("GPL");
49
50
51#define MEMORY_INVALID_STATE 0
52#define MEMORY_POWER_ON_STATE 1
53#define MEMORY_POWER_OFF_STATE 2
54
55static int acpi_memory_device_add(struct acpi_device *device);
56static int acpi_memory_device_remove(struct acpi_device *device, int type);
57
58static const struct acpi_device_id memory_device_ids[] = {
59 {ACPI_MEMORY_DEVICE_HID, 0},
60 {"", 0},
61};
62MODULE_DEVICE_TABLE(acpi, memory_device_ids);
63
64static struct acpi_driver acpi_memory_device_driver = {
65 .name = "acpi_memhotplug",
66 .class = ACPI_MEMORY_DEVICE_CLASS,
67 .ids = memory_device_ids,
68 .ops = {
69 .add = acpi_memory_device_add,
70 .remove = acpi_memory_device_remove,
71 },
72};
73
74struct acpi_memory_info {
75 struct list_head list;
76 u64 start_addr;
77 u64 length;
78 unsigned short caching;
79 unsigned short write_protect;
80 unsigned int enabled:1;
81};
82
83struct acpi_memory_device {
84 struct acpi_device * device;
85 unsigned int state;
86 struct list_head res_list;
87};
88
89static int acpi_hotmem_initialized;
90
91static acpi_status
92acpi_memory_get_resource(struct acpi_resource *resource, void *context)
93{
94 struct acpi_memory_device *mem_device = context;
95 struct acpi_resource_address64 address64;
96 struct acpi_memory_info *info, *new;
97 acpi_status status;
98
99 status = acpi_resource_to_address64(resource, &address64);
100 if (ACPI_FAILURE(status) ||
101 (address64.resource_type != ACPI_MEMORY_RANGE))
102 return AE_OK;
103
104 list_for_each_entry(info, &mem_device->res_list, list) {
105
106 if ((info->caching == address64.info.mem.caching) &&
107 (info->write_protect == address64.info.mem.write_protect) &&
108 (info->start_addr + info->length == address64.minimum)) {
109 info->length += address64.address_length;
110 return AE_OK;
111 }
112 }
113
114 new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
115 if (!new)
116 return AE_ERROR;
117
118 INIT_LIST_HEAD(&new->list);
119 new->caching = address64.info.mem.caching;
120 new->write_protect = address64.info.mem.write_protect;
121 new->start_addr = address64.minimum;
122 new->length = address64.address_length;
123 list_add_tail(&new->list, &mem_device->res_list);
124
125 return AE_OK;
126}
127
128static int
129acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
130{
131 acpi_status status;
132 struct acpi_memory_info *info, *n;
133
134
135 if (!list_empty(&mem_device->res_list))
136 return 0;
137
138 status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
139 acpi_memory_get_resource, mem_device);
140 if (ACPI_FAILURE(status)) {
141 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
142 kfree(info);
143 INIT_LIST_HEAD(&mem_device->res_list);
144 return -EINVAL;
145 }
146
147 return 0;
148}
149
150static int
151acpi_memory_get_device(acpi_handle handle,
152 struct acpi_memory_device **mem_device)
153{
154 acpi_status status;
155 acpi_handle phandle;
156 struct acpi_device *device = NULL;
157 struct acpi_device *pdevice = NULL;
158 int result;
159
160
161 if (!acpi_bus_get_device(handle, &device) && device)
162 goto end;
163
164 status = acpi_get_parent(handle, &phandle);
165 if (ACPI_FAILURE(status)) {
166 ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
167 return -EINVAL;
168 }
169
170
171 result = acpi_bus_get_device(phandle, &pdevice);
172 if (result) {
173 printk(KERN_WARNING PREFIX "Cannot get acpi bus device");
174 return -EINVAL;
175 }
176
177
178
179
180
181 result = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
182 if (result) {
183 printk(KERN_WARNING PREFIX "Cannot add acpi bus");
184 return -EINVAL;
185 }
186
187 end:
188 *mem_device = acpi_driver_data(device);
189 if (!(*mem_device)) {
190 printk(KERN_ERR "\n driver data not found");
191 return -ENODEV;
192 }
193
194 return 0;
195}
196
197static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
198{
199 unsigned long long current_status;
200
201
202 if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
203 NULL, ¤t_status)))
204 return -ENODEV;
205
206
207
208
209 if (!((current_status & ACPI_STA_DEVICE_PRESENT)
210 && (current_status & ACPI_STA_DEVICE_ENABLED)
211 && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
212 return -ENODEV;
213
214 return 0;
215}
216
217static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
218{
219 int result, num_enabled = 0;
220 struct acpi_memory_info *info;
221 int node;
222
223
224
225 result = acpi_memory_get_device_resources(mem_device);
226 if (result) {
227 printk(KERN_ERR PREFIX "get_device_resources failed\n");
228 mem_device->state = MEMORY_INVALID_STATE;
229 return result;
230 }
231
232 node = acpi_get_node(mem_device->device->handle);
233
234
235
236
237
238
239 list_for_each_entry(info, &mem_device->res_list, list) {
240 if (info->enabled) {
241 num_enabled++;
242 continue;
243 }
244
245
246
247
248 if (!info->length)
249 continue;
250 if (node < 0)
251 node = memory_add_physaddr_to_nid(info->start_addr);
252
253 result = add_memory(node, info->start_addr, info->length);
254 if (result)
255 continue;
256 info->enabled = 1;
257 num_enabled++;
258 }
259 if (!num_enabled) {
260 printk(KERN_ERR PREFIX "add_memory failed\n");
261 mem_device->state = MEMORY_INVALID_STATE;
262 return -EINVAL;
263 }
264
265
266
267
268
269
270
271
272 return 0;
273}
274
275static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
276{
277 acpi_status status;
278 struct acpi_object_list arg_list;
279 union acpi_object arg;
280 unsigned long long current_status;
281
282
283
284 arg_list.count = 1;
285 arg_list.pointer = &arg;
286 arg.type = ACPI_TYPE_INTEGER;
287 arg.integer.value = 1;
288 status = acpi_evaluate_object(mem_device->device->handle,
289 "_EJ0", &arg_list, NULL);
290
291 if (ACPI_FAILURE(status)) {
292 ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
293 return -ENODEV;
294 }
295
296
297 status = acpi_evaluate_integer(mem_device->device->handle, "_STA",
298 NULL, ¤t_status);
299 if (ACPI_FAILURE(status))
300 return -ENODEV;
301
302
303 if (current_status & ACPI_STA_DEVICE_ENABLED)
304 return -EINVAL;
305
306 return 0;
307}
308
309static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
310{
311 int result;
312 struct acpi_memory_info *info, *n;
313
314
315
316
317
318
319 list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
320 if (info->enabled) {
321 result = remove_memory(info->start_addr, info->length);
322 if (result)
323 return result;
324 }
325 kfree(info);
326 }
327
328
329 result = acpi_memory_powerdown_device(mem_device);
330 if (result) {
331
332 mem_device->state = MEMORY_INVALID_STATE;
333 return result;
334 }
335
336 mem_device->state = MEMORY_POWER_OFF_STATE;
337 return result;
338}
339
340static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
341{
342 struct acpi_memory_device *mem_device;
343 struct acpi_device *device;
344
345
346 switch (event) {
347 case ACPI_NOTIFY_BUS_CHECK:
348 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
349 "\nReceived BUS CHECK notification for device\n"));
350
351 case ACPI_NOTIFY_DEVICE_CHECK:
352 if (event == ACPI_NOTIFY_DEVICE_CHECK)
353 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
354 "\nReceived DEVICE CHECK notification for device\n"));
355 if (acpi_memory_get_device(handle, &mem_device)) {
356 printk(KERN_ERR PREFIX "Cannot find driver data\n");
357 return;
358 }
359
360 if (!acpi_memory_check_device(mem_device)) {
361 if (acpi_memory_enable_device(mem_device))
362 printk(KERN_ERR PREFIX
363 "Cannot enable memory device\n");
364 }
365 break;
366 case ACPI_NOTIFY_EJECT_REQUEST:
367 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
368 "\nReceived EJECT REQUEST notification for device\n"));
369
370 if (acpi_bus_get_device(handle, &device)) {
371 printk(KERN_ERR PREFIX "Device doesn't exist\n");
372 break;
373 }
374 mem_device = acpi_driver_data(device);
375 if (!mem_device) {
376 printk(KERN_ERR PREFIX "Driver Data is NULL\n");
377 break;
378 }
379
380
381
382
383
384
385
386 if (acpi_memory_disable_device(mem_device))
387 printk(KERN_ERR PREFIX
388 "Disable memory device\n");
389
390
391
392 break;
393 default:
394 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
395 "Unsupported event [0x%x]\n", event));
396 break;
397 }
398
399 return;
400}
401
402static int acpi_memory_device_add(struct acpi_device *device)
403{
404 int result;
405 struct acpi_memory_device *mem_device = NULL;
406
407
408 if (!device)
409 return -EINVAL;
410
411 mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
412 if (!mem_device)
413 return -ENOMEM;
414
415 INIT_LIST_HEAD(&mem_device->res_list);
416 mem_device->device = device;
417 sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
418 sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
419 device->driver_data = mem_device;
420
421
422 result = acpi_memory_get_device_resources(mem_device);
423 if (result) {
424 kfree(mem_device);
425 return result;
426 }
427
428
429 mem_device->state = MEMORY_POWER_ON_STATE;
430
431 printk(KERN_DEBUG "%s \n", acpi_device_name(device));
432
433
434
435
436
437
438
439 if (!acpi_hotmem_initialized)
440 return 0;
441
442 if (!acpi_memory_check_device(mem_device)) {
443
444 result = acpi_memory_enable_device(mem_device);
445 if (result)
446 printk(KERN_ERR PREFIX
447 "Error in acpi_memory_enable_device\n");
448 }
449 return result;
450}
451
452static int acpi_memory_device_remove(struct acpi_device *device, int type)
453{
454 struct acpi_memory_device *mem_device = NULL;
455
456
457 if (!device || !acpi_driver_data(device))
458 return -EINVAL;
459
460 mem_device = acpi_driver_data(device);
461 kfree(mem_device);
462
463 return 0;
464}
465
466
467
468
469static acpi_status is_memory_device(acpi_handle handle)
470{
471 char *hardware_id;
472 acpi_status status;
473 struct acpi_device_info *info;
474
475 status = acpi_get_object_info(handle, &info);
476 if (ACPI_FAILURE(status))
477 return status;
478
479 if (!(info->valid & ACPI_VALID_HID)) {
480 kfree(info);
481 return AE_ERROR;
482 }
483
484 hardware_id = info->hardware_id.string;
485 if ((hardware_id == NULL) ||
486 (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
487 status = AE_ERROR;
488
489 kfree(info);
490 return status;
491}
492
493static acpi_status
494acpi_memory_register_notify_handler(acpi_handle handle,
495 u32 level, void *ctxt, void **retv)
496{
497 acpi_status status;
498
499
500 status = is_memory_device(handle);
501 if (ACPI_FAILURE(status))
502 return AE_OK;
503
504 status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
505 acpi_memory_device_notify, NULL);
506
507 return AE_OK;
508}
509
510static acpi_status
511acpi_memory_deregister_notify_handler(acpi_handle handle,
512 u32 level, void *ctxt, void **retv)
513{
514 acpi_status status;
515
516
517 status = is_memory_device(handle);
518 if (ACPI_FAILURE(status))
519 return AE_OK;
520
521 status = acpi_remove_notify_handler(handle,
522 ACPI_SYSTEM_NOTIFY,
523 acpi_memory_device_notify);
524
525 return AE_OK;
526}
527
528static int __init acpi_memory_device_init(void)
529{
530 int result;
531 acpi_status status;
532
533
534 result = acpi_bus_register_driver(&acpi_memory_device_driver);
535
536 if (result < 0)
537 return -ENODEV;
538
539 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
540 ACPI_UINT32_MAX,
541 acpi_memory_register_notify_handler, NULL,
542 NULL, NULL);
543
544 if (ACPI_FAILURE(status)) {
545 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
546 acpi_bus_unregister_driver(&acpi_memory_device_driver);
547 return -ENODEV;
548 }
549
550 acpi_hotmem_initialized = 1;
551 return 0;
552}
553
554static void __exit acpi_memory_device_exit(void)
555{
556 acpi_status status;
557
558
559
560
561
562
563 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
564 ACPI_UINT32_MAX,
565 acpi_memory_deregister_notify_handler, NULL,
566 NULL, NULL);
567
568 if (ACPI_FAILURE(status))
569 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
570
571 acpi_bus_unregister_driver(&acpi_memory_device_driver);
572
573 return;
574}
575
576module_init(acpi_memory_device_init);
577module_exit(acpi_memory_device_exit);
578