1 /*
2 * Copyright (C) 2004 Intel Corporation <naveen.b.s@intel.com>
3 *
4 * All rights reserved.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or (at
9 * your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
14 * NON INFRINGEMENT. See the GNU General Public License for more
15 * details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 *
21 *
22 * ACPI based HotPlug driver that supports Memory Hotplug
23 * This driver fields notifications from firmare for memory add
24 * and remove operations and alerts the VM of the affected memory
25 * ranges.
26 */
27
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 <acpi/acpi_drivers.h>
34
35 #define ACPI_MEMORY_DEVICE_COMPONENT 0x08000000UL
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 ACPI_MODULE_NAME("acpi_memhotplug");
43 MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>");
44 MODULE_DESCRIPTION("Hotplug Mem Driver");
45 MODULE_LICENSE("GPL");
46
47 /* Memory Device States */
48 #define MEMORY_INVALID_STATE 0
49 #define MEMORY_POWER_ON_STATE 1
50 #define MEMORY_POWER_OFF_STATE 2
51
52 static int acpi_memory_device_add(struct acpi_device *device);
53 static int acpi_memory_device_remove(struct acpi_device *device, int type);
54 static int acpi_memory_device_start(struct acpi_device *device);
55
56 static const struct acpi_device_id memory_device_ids[] = {
57 {ACPI_MEMORY_DEVICE_HID, 0},
58 {"", 0},
59 };
60 MODULE_DEVICE_TABLE(acpi, memory_device_ids);
61
62 static struct acpi_driver acpi_memory_device_driver = {
63 .name = "acpi_memhotplug",
64 .class = ACPI_MEMORY_DEVICE_CLASS,
65 .ids = memory_device_ids,
66 .ops = {
67 .add = acpi_memory_device_add,
68 .remove = acpi_memory_device_remove,
69 .start = acpi_memory_device_start,
70 },
71 };
72
73 struct acpi_memory_info {
74 struct list_head list;
75 u64 start_addr; /* Memory Range start physical addr */
76 u64 length; /* Memory Range length */
77 unsigned short caching; /* memory cache attribute */
78 unsigned short write_protect; /* memory read/write attribute */
79 unsigned int enabled:1;
80 };
81
82 struct acpi_memory_device {
83 struct acpi_device * device;
84 unsigned int state; /* State of the memory device */
85 struct list_head res_list;
86 };
87
88 static int acpi_hotmem_initialized;
89
90 static acpi_status
91 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
92 {
93 struct acpi_memory_device *mem_device = context;
94 struct acpi_resource_address64 address64;
95 struct acpi_memory_info *info, *new;
96 acpi_status status;
97
98 status = acpi_resource_to_address64(resource, &address64);
99 if (ACPI_FAILURE(status) ||
100 (address64.resource_type != ACPI_MEMORY_RANGE))
101 return AE_OK;
102
103 list_for_each_entry(info, &mem_device->res_list, list) {
104 /* Can we combine the resource range information? */
105 if ((info->caching == address64.info.mem.caching) &&
106 (info->write_protect == address64.info.mem.write_protect) &&
107 (info->start_addr + info->length == address64.minimum)) {
108 info->length += address64.address_length;
109 return AE_OK;
110 }
111 }
112
113 new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
114 if (!new)
115 return AE_ERROR;
116
117 INIT_LIST_HEAD(&new->list);
118 new->caching = address64.info.mem.caching;
119 new->write_protect = address64.info.mem.write_protect;
120 new->start_addr = address64.minimum;
121 new->length = address64.address_length;
122 list_add_tail(&new->list, &mem_device->res_list);
123
124 return AE_OK;
125 }
126
127 static int
128 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
129 {
130 acpi_status status;
131 struct acpi_memory_info *info, *n;
132
133
134 if (!list_empty(&mem_device->res_list))
135 return 0;
136
137 status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
138 acpi_memory_get_resource, mem_device);
139 if (ACPI_FAILURE(status)) {
140 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
141 kfree(info);
142 INIT_LIST_HEAD(&mem_device->res_list);
143 return -EINVAL;
144 }
145
146 return 0;
147 }
148
149 static int
150 acpi_memory_get_device(acpi_handle handle,
151 struct acpi_memory_device **mem_device)
152 {
153 acpi_status status;
154 acpi_handle phandle;
155 struct acpi_device *device = NULL;
156 struct acpi_device *pdevice = NULL;
157
158
159 if (!acpi_bus_get_device(handle, &device) && device)
160 goto end;
161
162 status = acpi_get_parent(handle, &phandle);
163 if (ACPI_FAILURE(status)) {
164 ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
165 return -EINVAL;
166 }
167
168 /* Get the parent device */
169 status = acpi_bus_get_device(phandle, &pdevice);
170 if (ACPI_FAILURE(status)) {
171 ACPI_EXCEPTION((AE_INFO, status, "Cannot get acpi bus device"));
172 return -EINVAL;
173 }
174
175 /*
176 * Now add the notified device. This creates the acpi_device
177 * and invokes .add function
178 */
179 status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
180 if (ACPI_FAILURE(status)) {
181 ACPI_EXCEPTION((AE_INFO, status, "Cannot add acpi bus"));
182 return -EINVAL;
183 }
184
185 end:
186 *mem_device = acpi_driver_data(device);
187 if (!(*mem_device)) {
188 printk(KERN_ERR "\n driver data not found");
189 return -ENODEV;
190 }
191
192 return 0;
193 }
194
195 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
196 {
197 unsigned long current_status;
198
199
200 /* Get device present/absent information from the _STA */
201 if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
202 NULL, ¤t_status)))
203 return -ENODEV;
204 /*
205 * Check for device status. Device should be
206 * present/enabled/functioning.
207 */
208 if (!((current_status & ACPI_STA_DEVICE_PRESENT)
209 && (current_status & ACPI_STA_DEVICE_ENABLED)
210 && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
211 return -ENODEV;
212
213 return 0;
214 }
215
216 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
217 {
218 int result, num_enabled = 0;
219 struct acpi_memory_info *info;
220 int node;
221
222
223 /* Get the range from the _CRS */
224 result = acpi_memory_get_device_resources(mem_device);
225 if (result) {
226 printk(KERN_ERR PREFIX "get_device_resources failed\n");
227 mem_device->state = MEMORY_INVALID_STATE;
228 return result;
229 }
230
231 node = acpi_get_node(mem_device->device->handle);
232 /*
233 * Tell the VM there is more memory here...
234 * Note: Assume that this function returns zero on success
235 * We don't have memory-hot-add rollback function,now.
236 * (i.e. memory-hot-remove function)
237 */
238 list_for_each_entry(info, &mem_device->res_list, list) {
239 if (info->enabled) { /* just sanity check...*/
240 num_enabled++;
241 continue;
242 }
243
244 if (node < 0)
245 node = memory_add_physaddr_to_nid(info->start_addr);
246
247 result = add_memory(node, info->start_addr, info->length);
248 if (result)
249 continue;
250 info->enabled = 1;
251 num_enabled++;
252 }
253 if (!num_enabled) {
254 printk(KERN_ERR PREFIX "add_memory failed\n");
255 mem_device->state = MEMORY_INVALID_STATE;
256 return -EINVAL;
257 }
258
259 return result;
260 }
261
262 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
263 {
264 acpi_status status;
265 struct acpi_object_list arg_list;
266 union acpi_object arg;
267 unsigned long current_status;
268
269
270 /* Issue the _EJ0 command */
271 arg_list.count = 1;
272 arg_list.pointer = &arg;
273 arg.type = ACPI_TYPE_INTEGER;
274 arg.integer.value = 1;
275 status = acpi_evaluate_object(mem_device->device->handle,
276 "_EJ0", &arg_list, NULL);
277 /* Return on _EJ0 failure */
278 if (ACPI_FAILURE(status)) {
279 ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
280 return -ENODEV;
281 }
282
283 /* Evalute _STA to check if the device is disabled */
284 status = acpi_evaluate_integer(mem_device->device->handle, "_STA",
285 NULL, ¤t_status);
286 if (ACPI_FAILURE(status))
287 return -ENODEV;
288
289 /* Check for device status. Device should be disabled */
290 if (current_status & ACPI_STA_DEVICE_ENABLED)
291 return -EINVAL;
292
293 return 0;
294 }
295
296 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
297 {
298 int result;
299 struct acpi_memory_info *info, *n;
300
301
302 /*
303 * Ask the VM to offline this memory range.
304 * Note: Assume that this function returns zero on success
305 */
306 list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
307 if (info->enabled) {
308 result = remove_memory(info->start_addr, info->length);
309 if (result)
310 return result;
311 }
312 kfree(info);
313 }
314
315 /* Power-off and eject the device */
316 result = acpi_memory_powerdown_device(mem_device);
317 if (result) {
318 /* Set the status of the device to invalid */
319 mem_device->state = MEMORY_INVALID_STATE;
320 return result;
321 }
322
323 mem_device->state = MEMORY_POWER_OFF_STATE;
324 return result;
325 }
326
327 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
328 {
329 struct acpi_memory_device *mem_device;
330 struct acpi_device *device;
331
332
333 switch (event) {
334 case ACPI_NOTIFY_BUS_CHECK:
335 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
336 "\nReceived BUS CHECK notification for device\n"));
337 /* Fall Through */
338 case ACPI_NOTIFY_DEVICE_CHECK:
339 if (event == ACPI_NOTIFY_DEVICE_CHECK)
340 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
341 "\nReceived DEVICE CHECK notification for device\n"));
342 if (acpi_memory_get_device(handle, &mem_device)) {
343 printk(KERN_ERR PREFIX "Cannot find driver data\n");
344 return;
345 }
346
347 if (!acpi_memory_check_device(mem_device)) {
348 if (acpi_memory_enable_device(mem_device))
349 printk(KERN_ERR PREFIX
350 "Cannot enable memory device\n");
351 }
352 break;
353 case ACPI_NOTIFY_EJECT_REQUEST:
354 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
355 "\nReceived EJECT REQUEST notification for device\n"));
356
357 if (acpi_bus_get_device(handle, &device)) {
358 printk(KERN_ERR PREFIX "Device doesn't exist\n");
359 break;
360 }
361 mem_device = acpi_driver_data(device);
362 if (!mem_device) {
363 printk(KERN_ERR PREFIX "Driver Data is NULL\n");
364 break;
365 }
366
367 /*
368 * Currently disabling memory device from kernel mode
369 * TBD: Can also be disabled from user mode scripts
370 * TBD: Can also be disabled by Callback registration
371 * with generic sysfs driver
372 */
373 if (acpi_memory_disable_device(mem_device))
374 printk(KERN_ERR PREFIX
375 "Disable memory device\n");
376 /*
377 * TBD: Invoke acpi_bus_remove to cleanup data structures
378 */
379 break;
380 default:
381 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
382 "Unsupported event [0x%x]\n", event));
383 break;
384 }
385
386 return;
387 }
388
389 static int acpi_memory_device_add(struct acpi_device *device)
390 {
391 int result;
392 struct acpi_memory_device *mem_device = NULL;
393
394
395 if (!device)
396 return -EINVAL;
397
398 mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
399 if (!mem_device)
400 return -ENOMEM;
401
402 INIT_LIST_HEAD(&mem_device->res_list);
403 mem_device->device = device;
404 sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
405 sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
406 acpi_driver_data(device) = mem_device;
407
408 /* Get the range from the _CRS */
409 result = acpi_memory_get_device_resources(mem_device);
410 if (result) {
411 kfree(mem_device);
412 return result;
413 }
414
415 /* Set the device state */
416 mem_device->state = MEMORY_POWER_ON_STATE;
417
418 printk(KERN_DEBUG "%s \n", acpi_device_name(device));
419
420 return result;
421 }
422
423 static int acpi_memory_device_remove(struct acpi_device *device, int type)
424 {
425 struct acpi_memory_device *mem_device = NULL;
426
427
428 if (!device || !acpi_driver_data(device))
429 return -EINVAL;
430
431 mem_device = acpi_driver_data(device);
432 kfree(mem_device);
433
434 return 0;
435 }
436
437 static int acpi_memory_device_start (struct acpi_device *device)
438 {
439 struct acpi_memory_device *mem_device;
440 int result = 0;
441
442 /*
443 * Early boot code has recognized memory area by EFI/E820.
444 * If DSDT shows these memory devices on boot, hotplug is not necessary
445 * for them. So, it just returns until completion of this driver's
446 * start up.
447 */
448 if (!acpi_hotmem_initialized)
449 return 0;
450
451 mem_device = acpi_driver_data(device);
452
453 if (!acpi_memory_check_device(mem_device)) {
454 /* call add_memory func */
455 result = acpi_memory_enable_device(mem_device);
456 if (result)
457 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
458 "Error in acpi_memory_enable_device\n"));
459 }
460 return result;
461 }
462
463 /*
464 * Helper function to check for memory device
465 */
466 static acpi_status is_memory_device(acpi_handle handle)
467 {
468 char *hardware_id;
469 acpi_status status;
470 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
471 struct acpi_device_info *info;
472
473
474 status = acpi_get_object_info(handle, &buffer);
475 if (ACPI_FAILURE(status))
476 return status;
477
478 info = buffer.pointer;
479 if (!(info->valid & ACPI_VALID_HID)) {
480 kfree(buffer.pointer);
481 return AE_ERROR;
482 }
483
484 hardware_id = info->hardware_id.value;
485 if ((hardware_id == NULL) ||
486 (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
487 status = AE_ERROR;
488
489 kfree(buffer.pointer);
490 return status;
491 }
492
493 static acpi_status
494 acpi_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; /* continue */
503
504 status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
505 acpi_memory_device_notify, NULL);
506 /* continue */
507 return AE_OK;
508 }
509
510 static acpi_status
511 acpi_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; /* continue */
520
521 status = acpi_remove_notify_handler(handle,
522 ACPI_SYSTEM_NOTIFY,
523 acpi_memory_device_notify);
524
525 return AE_OK; /* continue */
526 }
527
528 static 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,
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
554 static void __exit acpi_memory_device_exit(void)
555 {
556 acpi_status status;
557
558
559 /*
560 * Adding this to un-install notification handlers for all the device
561 * handles.
562 */
563 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
564 ACPI_UINT32_MAX,
565 acpi_memory_deregister_notify_handler,
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
576 module_init(acpi_memory_device_init);
577 module_exit(acpi_memory_device_exit);
578
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