Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
[linux-2.6] / drivers / acpi / acpi_memhotplug.c
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_DRIVER_NAME          "Hotplug Mem Driver"
39 #define ACPI_MEMORY_DEVICE_NAME                 "Hotplug Mem Device"
40
41 #define _COMPONENT              ACPI_MEMORY_DEVICE_COMPONENT
42
43 ACPI_MODULE_NAME("acpi_memory")
44     MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>");
45 MODULE_DESCRIPTION(ACPI_MEMORY_DEVICE_DRIVER_NAME);
46 MODULE_LICENSE("GPL");
47
48 /* ACPI _STA method values */
49 #define ACPI_MEMORY_STA_PRESENT         (0x00000001UL)
50 #define ACPI_MEMORY_STA_ENABLED         (0x00000002UL)
51 #define ACPI_MEMORY_STA_FUNCTIONAL      (0x00000008UL)
52
53 /* Memory Device States */
54 #define MEMORY_INVALID_STATE    0
55 #define MEMORY_POWER_ON_STATE   1
56 #define MEMORY_POWER_OFF_STATE  2
57
58 static int acpi_memory_device_add(struct acpi_device *device);
59 static int acpi_memory_device_remove(struct acpi_device *device, int type);
60
61 static struct acpi_driver acpi_memory_device_driver = {
62         .name = ACPI_MEMORY_DEVICE_DRIVER_NAME,
63         .class = ACPI_MEMORY_DEVICE_CLASS,
64         .ids = ACPI_MEMORY_DEVICE_HID,
65         .ops = {
66                 .add = acpi_memory_device_add,
67                 .remove = acpi_memory_device_remove,
68                 },
69 };
70
71 struct acpi_memory_device {
72         acpi_handle handle;
73         unsigned int state;     /* State of the memory device */
74         unsigned short caching; /* memory cache attribute */
75         unsigned short write_protect;   /* memory read/write attribute */
76         u64 start_addr;         /* Memory Range start physical addr */
77         u64 length;             /* Memory Range length */
78 };
79
80 static int
81 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
82 {
83         acpi_status status;
84         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
85         struct acpi_resource *resource = NULL;
86         struct acpi_resource_address64 address64;
87
88         ACPI_FUNCTION_TRACE("acpi_memory_get_device_resources");
89
90         /* Get the range from the _CRS */
91         status = acpi_get_current_resources(mem_device->handle, &buffer);
92         if (ACPI_FAILURE(status))
93                 return_VALUE(-EINVAL);
94
95         resource = (struct acpi_resource *)buffer.pointer;
96         status = acpi_resource_to_address64(resource, &address64);
97         if (ACPI_SUCCESS(status)) {
98                 if (address64.resource_type == ACPI_MEMORY_RANGE) {
99                         /* Populate the structure */
100                         mem_device->caching = address64.info.mem.caching;
101                         mem_device->write_protect =
102                             address64.info.mem.write_protect;
103                         mem_device->start_addr = address64.minimum;
104                         mem_device->length = address64.address_length;
105                 }
106         }
107
108         acpi_os_free(buffer.pointer);
109         return_VALUE(0);
110 }
111
112 static int
113 acpi_memory_get_device(acpi_handle handle,
114                        struct acpi_memory_device **mem_device)
115 {
116         acpi_status status;
117         acpi_handle phandle;
118         struct acpi_device *device = NULL;
119         struct acpi_device *pdevice = NULL;
120
121         ACPI_FUNCTION_TRACE("acpi_memory_get_device");
122
123         if (!acpi_bus_get_device(handle, &device) && device)
124                 goto end;
125
126         status = acpi_get_parent(handle, &phandle);
127         if (ACPI_FAILURE(status)) {
128                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error in acpi_get_parent\n"));
129                 return_VALUE(-EINVAL);
130         }
131
132         /* Get the parent device */
133         status = acpi_bus_get_device(phandle, &pdevice);
134         if (ACPI_FAILURE(status)) {
135                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
136                                   "Error in acpi_bus_get_device\n"));
137                 return_VALUE(-EINVAL);
138         }
139
140         /*
141          * Now add the notified device.  This creates the acpi_device
142          * and invokes .add function
143          */
144         status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
145         if (ACPI_FAILURE(status)) {
146                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error in acpi_bus_add\n"));
147                 return_VALUE(-EINVAL);
148         }
149
150       end:
151         *mem_device = acpi_driver_data(device);
152         if (!(*mem_device)) {
153                 printk(KERN_ERR "\n driver data not found");
154                 return_VALUE(-ENODEV);
155         }
156
157         return_VALUE(0);
158 }
159
160 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
161 {
162         unsigned long current_status;
163
164         ACPI_FUNCTION_TRACE("acpi_memory_check_device");
165
166         /* Get device present/absent information from the _STA */
167         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->handle, "_STA",
168                                                NULL, &current_status)))
169                 return_VALUE(-ENODEV);
170         /*
171          * Check for device status. Device should be
172          * present/enabled/functioning.
173          */
174         if (!((current_status & ACPI_MEMORY_STA_PRESENT)
175               && (current_status & ACPI_MEMORY_STA_ENABLED)
176               && (current_status & ACPI_MEMORY_STA_FUNCTIONAL)))
177                 return_VALUE(-ENODEV);
178
179         return_VALUE(0);
180 }
181
182 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
183 {
184         int result;
185
186         ACPI_FUNCTION_TRACE("acpi_memory_enable_device");
187
188         /* Get the range from the _CRS */
189         result = acpi_memory_get_device_resources(mem_device);
190         if (result) {
191                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
192                                   "\nget_device_resources failed\n"));
193                 mem_device->state = MEMORY_INVALID_STATE;
194                 return result;
195         }
196
197         /*
198          * Tell the VM there is more memory here...
199          * Note: Assume that this function returns zero on success
200          */
201         result = add_memory(mem_device->start_addr, mem_device->length);
202         if (result) {
203                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "\nadd_memory failed\n"));
204                 mem_device->state = MEMORY_INVALID_STATE;
205                 return result;
206         }
207
208         return result;
209 }
210
211 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
212 {
213         acpi_status status;
214         struct acpi_object_list arg_list;
215         union acpi_object arg;
216         unsigned long current_status;
217
218         ACPI_FUNCTION_TRACE("acpi_memory_powerdown_device");
219
220         /* Issue the _EJ0 command */
221         arg_list.count = 1;
222         arg_list.pointer = &arg;
223         arg.type = ACPI_TYPE_INTEGER;
224         arg.integer.value = 1;
225         status = acpi_evaluate_object(mem_device->handle,
226                                       "_EJ0", &arg_list, NULL);
227         /* Return on _EJ0 failure */
228         if (ACPI_FAILURE(status)) {
229                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "_EJ0 failed.\n"));
230                 return_VALUE(-ENODEV);
231         }
232
233         /* Evalute _STA to check if the device is disabled */
234         status = acpi_evaluate_integer(mem_device->handle, "_STA",
235                                        NULL, &current_status);
236         if (ACPI_FAILURE(status))
237                 return_VALUE(-ENODEV);
238
239         /* Check for device status.  Device should be disabled */
240         if (current_status & ACPI_MEMORY_STA_ENABLED)
241                 return_VALUE(-EINVAL);
242
243         return_VALUE(0);
244 }
245
246 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
247 {
248         int result;
249         u64 start = mem_device->start_addr;
250         u64 len = mem_device->length;
251
252         ACPI_FUNCTION_TRACE("acpi_memory_disable_device");
253
254         /*
255          * Ask the VM to offline this memory range.
256          * Note: Assume that this function returns zero on success
257          */
258         result = remove_memory(start, len);
259         if (result) {
260                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Hot-Remove failed.\n"));
261                 return_VALUE(result);
262         }
263
264         /* Power-off and eject the device */
265         result = acpi_memory_powerdown_device(mem_device);
266         if (result) {
267                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
268                                   "Device Power Down failed.\n"));
269                 /* Set the status of the device to invalid */
270                 mem_device->state = MEMORY_INVALID_STATE;
271                 return result;
272         }
273
274         mem_device->state = MEMORY_POWER_OFF_STATE;
275         return result;
276 }
277
278 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
279 {
280         struct acpi_memory_device *mem_device;
281         struct acpi_device *device;
282
283         ACPI_FUNCTION_TRACE("acpi_memory_device_notify");
284
285         switch (event) {
286         case ACPI_NOTIFY_BUS_CHECK:
287                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
288                                   "\nReceived BUS CHECK notification for device\n"));
289                 /* Fall Through */
290         case ACPI_NOTIFY_DEVICE_CHECK:
291                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
292                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
293                                           "\nReceived DEVICE CHECK notification for device\n"));
294                 if (acpi_memory_get_device(handle, &mem_device)) {
295                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
296                                           "Error in finding driver data\n"));
297                         return_VOID;
298                 }
299
300                 if (!acpi_memory_check_device(mem_device)) {
301                         if (acpi_memory_enable_device(mem_device))
302                                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
303                                                   "Error in acpi_memory_enable_device\n"));
304                 }
305                 break;
306         case ACPI_NOTIFY_EJECT_REQUEST:
307                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
308                                   "\nReceived EJECT REQUEST notification for device\n"));
309
310                 if (acpi_bus_get_device(handle, &device)) {
311                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
312                                           "Device doesn't exist\n"));
313                         break;
314                 }
315                 mem_device = acpi_driver_data(device);
316                 if (!mem_device) {
317                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
318                                           "Driver Data is NULL\n"));
319                         break;
320                 }
321
322                 /*
323                  * Currently disabling memory device from kernel mode
324                  * TBD: Can also be disabled from user mode scripts
325                  * TBD: Can also be disabled by Callback registration
326                  *      with generic sysfs driver
327                  */
328                 if (acpi_memory_disable_device(mem_device))
329                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
330                                           "Error in acpi_memory_disable_device\n"));
331                 /*
332                  * TBD: Invoke acpi_bus_remove to cleanup data structures
333                  */
334                 break;
335         default:
336                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
337                                   "Unsupported event [0x%x]\n", event));
338                 break;
339         }
340
341         return_VOID;
342 }
343
344 static int acpi_memory_device_add(struct acpi_device *device)
345 {
346         int result;
347         struct acpi_memory_device *mem_device = NULL;
348
349         ACPI_FUNCTION_TRACE("acpi_memory_device_add");
350
351         if (!device)
352                 return_VALUE(-EINVAL);
353
354         mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
355         if (!mem_device)
356                 return_VALUE(-ENOMEM);
357         memset(mem_device, 0, sizeof(struct acpi_memory_device));
358
359         mem_device->handle = device->handle;
360         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
361         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
362         acpi_driver_data(device) = mem_device;
363
364         /* Get the range from the _CRS */
365         result = acpi_memory_get_device_resources(mem_device);
366         if (result) {
367                 kfree(mem_device);
368                 return_VALUE(result);
369         }
370
371         /* Set the device state */
372         mem_device->state = MEMORY_POWER_ON_STATE;
373
374         printk(KERN_INFO "%s \n", acpi_device_name(device));
375
376         return_VALUE(result);
377 }
378
379 static int acpi_memory_device_remove(struct acpi_device *device, int type)
380 {
381         struct acpi_memory_device *mem_device = NULL;
382
383         ACPI_FUNCTION_TRACE("acpi_memory_device_remove");
384
385         if (!device || !acpi_driver_data(device))
386                 return_VALUE(-EINVAL);
387
388         mem_device = (struct acpi_memory_device *)acpi_driver_data(device);
389         kfree(mem_device);
390
391         return_VALUE(0);
392 }
393
394 /*
395  * Helper function to check for memory device
396  */
397 static acpi_status is_memory_device(acpi_handle handle)
398 {
399         char *hardware_id;
400         acpi_status status;
401         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
402         struct acpi_device_info *info;
403
404         ACPI_FUNCTION_TRACE("is_memory_device");
405
406         status = acpi_get_object_info(handle, &buffer);
407         if (ACPI_FAILURE(status))
408                 return_ACPI_STATUS(AE_ERROR);
409
410         info = buffer.pointer;
411         if (!(info->valid & ACPI_VALID_HID)) {
412                 acpi_os_free(buffer.pointer);
413                 return_ACPI_STATUS(AE_ERROR);
414         }
415
416         hardware_id = info->hardware_id.value;
417         if ((hardware_id == NULL) ||
418             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
419                 status = AE_ERROR;
420
421         acpi_os_free(buffer.pointer);
422         return_ACPI_STATUS(status);
423 }
424
425 static acpi_status
426 acpi_memory_register_notify_handler(acpi_handle handle,
427                                     u32 level, void *ctxt, void **retv)
428 {
429         acpi_status status;
430
431         ACPI_FUNCTION_TRACE("acpi_memory_register_notify_handler");
432
433         status = is_memory_device(handle);
434         if (ACPI_FAILURE(status))
435                 return_ACPI_STATUS(AE_OK);      /* continue */
436
437         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
438                                              acpi_memory_device_notify, NULL);
439         if (ACPI_FAILURE(status)) {
440                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
441                                   "Error installing notify handler\n"));
442                 return_ACPI_STATUS(AE_OK);      /* continue */
443         }
444
445         return_ACPI_STATUS(status);
446 }
447
448 static acpi_status
449 acpi_memory_deregister_notify_handler(acpi_handle handle,
450                                       u32 level, void *ctxt, void **retv)
451 {
452         acpi_status status;
453
454         ACPI_FUNCTION_TRACE("acpi_memory_deregister_notify_handler");
455
456         status = is_memory_device(handle);
457         if (ACPI_FAILURE(status))
458                 return_ACPI_STATUS(AE_OK);      /* continue */
459
460         status = acpi_remove_notify_handler(handle,
461                                             ACPI_SYSTEM_NOTIFY,
462                                             acpi_memory_device_notify);
463         if (ACPI_FAILURE(status)) {
464                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
465                                   "Error removing notify handler\n"));
466                 return_ACPI_STATUS(AE_OK);      /* continue */
467         }
468
469         return_ACPI_STATUS(status);
470 }
471
472 static int __init acpi_memory_device_init(void)
473 {
474         int result;
475         acpi_status status;
476
477         ACPI_FUNCTION_TRACE("acpi_memory_device_init");
478
479         result = acpi_bus_register_driver(&acpi_memory_device_driver);
480
481         if (result < 0)
482                 return_VALUE(-ENODEV);
483
484         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
485                                      ACPI_UINT32_MAX,
486                                      acpi_memory_register_notify_handler,
487                                      NULL, NULL);
488
489         if (ACPI_FAILURE(status)) {
490                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n"));
491                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
492                 return_VALUE(-ENODEV);
493         }
494
495         return_VALUE(0);
496 }
497
498 static void __exit acpi_memory_device_exit(void)
499 {
500         acpi_status status;
501
502         ACPI_FUNCTION_TRACE("acpi_memory_device_exit");
503
504         /*
505          * Adding this to un-install notification handlers for all the device
506          * handles.
507          */
508         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
509                                      ACPI_UINT32_MAX,
510                                      acpi_memory_deregister_notify_handler,
511                                      NULL, NULL);
512
513         if (ACPI_FAILURE(status))
514                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n"));
515
516         acpi_bus_unregister_driver(&acpi_memory_device_driver);
517
518         return_VOID;
519 }
520
521 module_init(acpi_memory_device_init);
522 module_exit(acpi_memory_device_exit);