Pull sn-features into release branch
[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 cache_attribute; /* memory cache attribute */
75         unsigned short read_write_attribute;    /* memory read/write attribute */
76         u64 start_addr;         /* Memory Range start physical addr */
77         u64 end_addr;           /* Memory Range end physical addr */
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->cache_attribute =
101                             address64.attribute.memory.cache_attribute;
102                         mem_device->read_write_attribute =
103                             address64.attribute.memory.read_write_attribute;
104                         mem_device->start_addr = address64.min_address_range;
105                         mem_device->end_addr = address64.max_address_range;
106                 }
107         }
108
109         acpi_os_free(buffer.pointer);
110         return_VALUE(0);
111 }
112
113 static int
114 acpi_memory_get_device(acpi_handle handle,
115                        struct acpi_memory_device **mem_device)
116 {
117         acpi_status status;
118         acpi_handle phandle;
119         struct acpi_device *device = NULL;
120         struct acpi_device *pdevice = NULL;
121
122         ACPI_FUNCTION_TRACE("acpi_memory_get_device");
123
124         if (!acpi_bus_get_device(handle, &device) && device)
125                 goto end;
126
127         status = acpi_get_parent(handle, &phandle);
128         if (ACPI_FAILURE(status)) {
129                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error in acpi_get_parent\n"));
130                 return_VALUE(-EINVAL);
131         }
132
133         /* Get the parent device */
134         status = acpi_bus_get_device(phandle, &pdevice);
135         if (ACPI_FAILURE(status)) {
136                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
137                                   "Error in acpi_bus_get_device\n"));
138                 return_VALUE(-EINVAL);
139         }
140
141         /*
142          * Now add the notified device.  This creates the acpi_device
143          * and invokes .add function
144          */
145         status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
146         if (ACPI_FAILURE(status)) {
147                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error in acpi_bus_add\n"));
148                 return_VALUE(-EINVAL);
149         }
150
151       end:
152         *mem_device = acpi_driver_data(device);
153         if (!(*mem_device)) {
154                 printk(KERN_ERR "\n driver data not found");
155                 return_VALUE(-ENODEV);
156         }
157
158         return_VALUE(0);
159 }
160
161 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
162 {
163         unsigned long current_status;
164
165         ACPI_FUNCTION_TRACE("acpi_memory_check_device");
166
167         /* Get device present/absent information from the _STA */
168         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->handle, "_STA",
169                                                NULL, &current_status)))
170                 return_VALUE(-ENODEV);
171         /*
172          * Check for device status. Device should be
173          * present/enabled/functioning.
174          */
175         if (!((current_status & ACPI_MEMORY_STA_PRESENT)
176               && (current_status & ACPI_MEMORY_STA_ENABLED)
177               && (current_status & ACPI_MEMORY_STA_FUNCTIONAL)))
178                 return_VALUE(-ENODEV);
179
180         return_VALUE(0);
181 }
182
183 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
184 {
185         int result;
186
187         ACPI_FUNCTION_TRACE("acpi_memory_enable_device");
188
189         /* Get the range from the _CRS */
190         result = acpi_memory_get_device_resources(mem_device);
191         if (result) {
192                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
193                                   "\nget_device_resources failed\n"));
194                 mem_device->state = MEMORY_INVALID_STATE;
195                 return result;
196         }
197
198         /*
199          * Tell the VM there is more memory here...
200          * Note: Assume that this function returns zero on success
201          */
202         result = add_memory(mem_device->start_addr,
203                             (mem_device->end_addr - mem_device->start_addr) + 1,
204                             mem_device->read_write_attribute);
205         if (result) {
206                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "\nadd_memory failed\n"));
207                 mem_device->state = MEMORY_INVALID_STATE;
208                 return result;
209         }
210
211         return result;
212 }
213
214 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
215 {
216         acpi_status status;
217         struct acpi_object_list arg_list;
218         union acpi_object arg;
219         unsigned long current_status;
220
221         ACPI_FUNCTION_TRACE("acpi_memory_powerdown_device");
222
223         /* Issue the _EJ0 command */
224         arg_list.count = 1;
225         arg_list.pointer = &arg;
226         arg.type = ACPI_TYPE_INTEGER;
227         arg.integer.value = 1;
228         status = acpi_evaluate_object(mem_device->handle,
229                                       "_EJ0", &arg_list, NULL);
230         /* Return on _EJ0 failure */
231         if (ACPI_FAILURE(status)) {
232                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "_EJ0 failed.\n"));
233                 return_VALUE(-ENODEV);
234         }
235
236         /* Evalute _STA to check if the device is disabled */
237         status = acpi_evaluate_integer(mem_device->handle, "_STA",
238                                        NULL, &current_status);
239         if (ACPI_FAILURE(status))
240                 return_VALUE(-ENODEV);
241
242         /* Check for device status.  Device should be disabled */
243         if (current_status & ACPI_MEMORY_STA_ENABLED)
244                 return_VALUE(-EINVAL);
245
246         return_VALUE(0);
247 }
248
249 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
250 {
251         int result;
252         u64 start = mem_device->start_addr;
253         u64 len = mem_device->end_addr - start + 1;
254         unsigned long attr = mem_device->read_write_attribute;
255
256         ACPI_FUNCTION_TRACE("acpi_memory_disable_device");
257
258         /*
259          * Ask the VM to offline this memory range.
260          * Note: Assume that this function returns zero on success
261          */
262         result = remove_memory(start, len, attr);
263         if (result) {
264                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Hot-Remove failed.\n"));
265                 return_VALUE(result);
266         }
267
268         /* Power-off and eject the device */
269         result = acpi_memory_powerdown_device(mem_device);
270         if (result) {
271                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
272                                   "Device Power Down failed.\n"));
273                 /* Set the status of the device to invalid */
274                 mem_device->state = MEMORY_INVALID_STATE;
275                 return result;
276         }
277
278         mem_device->state = MEMORY_POWER_OFF_STATE;
279         return result;
280 }
281
282 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
283 {
284         struct acpi_memory_device *mem_device;
285         struct acpi_device *device;
286
287         ACPI_FUNCTION_TRACE("acpi_memory_device_notify");
288
289         switch (event) {
290         case ACPI_NOTIFY_BUS_CHECK:
291                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
292                                   "\nReceived BUS CHECK notification for device\n"));
293                 /* Fall Through */
294         case ACPI_NOTIFY_DEVICE_CHECK:
295                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
296                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
297                                           "\nReceived DEVICE CHECK notification for device\n"));
298                 if (acpi_memory_get_device(handle, &mem_device)) {
299                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
300                                           "Error in finding driver data\n"));
301                         return_VOID;
302                 }
303
304                 if (!acpi_memory_check_device(mem_device)) {
305                         if (acpi_memory_enable_device(mem_device))
306                                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
307                                                   "Error in acpi_memory_enable_device\n"));
308                 }
309                 break;
310         case ACPI_NOTIFY_EJECT_REQUEST:
311                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
312                                   "\nReceived EJECT REQUEST notification for device\n"));
313
314                 if (acpi_bus_get_device(handle, &device)) {
315                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
316                                           "Device doesn't exist\n"));
317                         break;
318                 }
319                 mem_device = acpi_driver_data(device);
320                 if (!mem_device) {
321                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
322                                           "Driver Data is NULL\n"));
323                         break;
324                 }
325
326                 /*
327                  * Currently disabling memory device from kernel mode
328                  * TBD: Can also be disabled from user mode scripts
329                  * TBD: Can also be disabled by Callback registration
330                  *      with generic sysfs driver
331                  */
332                 if (acpi_memory_disable_device(mem_device))
333                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
334                                           "Error in acpi_memory_disable_device\n"));
335                 /*
336                  * TBD: Invoke acpi_bus_remove to cleanup data structures
337                  */
338                 break;
339         default:
340                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
341                                   "Unsupported event [0x%x]\n", event));
342                 break;
343         }
344
345         return_VOID;
346 }
347
348 static int acpi_memory_device_add(struct acpi_device *device)
349 {
350         int result;
351         struct acpi_memory_device *mem_device = NULL;
352
353         ACPI_FUNCTION_TRACE("acpi_memory_device_add");
354
355         if (!device)
356                 return_VALUE(-EINVAL);
357
358         mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
359         if (!mem_device)
360                 return_VALUE(-ENOMEM);
361         memset(mem_device, 0, sizeof(struct acpi_memory_device));
362
363         mem_device->handle = device->handle;
364         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
365         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
366         acpi_driver_data(device) = mem_device;
367
368         /* Get the range from the _CRS */
369         result = acpi_memory_get_device_resources(mem_device);
370         if (result) {
371                 kfree(mem_device);
372                 return_VALUE(result);
373         }
374
375         /* Set the device state */
376         mem_device->state = MEMORY_POWER_ON_STATE;
377
378         printk(KERN_INFO "%s \n", acpi_device_name(device));
379
380         return_VALUE(result);
381 }
382
383 static int acpi_memory_device_remove(struct acpi_device *device, int type)
384 {
385         struct acpi_memory_device *mem_device = NULL;
386
387         ACPI_FUNCTION_TRACE("acpi_memory_device_remove");
388
389         if (!device || !acpi_driver_data(device))
390                 return_VALUE(-EINVAL);
391
392         mem_device = (struct acpi_memory_device *)acpi_driver_data(device);
393         kfree(mem_device);
394
395         return_VALUE(0);
396 }
397
398 /*
399  * Helper function to check for memory device
400  */
401 static acpi_status is_memory_device(acpi_handle handle)
402 {
403         char *hardware_id;
404         acpi_status status;
405         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
406         struct acpi_device_info *info;
407
408         ACPI_FUNCTION_TRACE("is_memory_device");
409
410         status = acpi_get_object_info(handle, &buffer);
411         if (ACPI_FAILURE(status))
412                 return_ACPI_STATUS(AE_ERROR);
413
414         info = buffer.pointer;
415         if (!(info->valid & ACPI_VALID_HID)) {
416                 acpi_os_free(buffer.pointer);
417                 return_ACPI_STATUS(AE_ERROR);
418         }
419
420         hardware_id = info->hardware_id.value;
421         if ((hardware_id == NULL) ||
422             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
423                 status = AE_ERROR;
424
425         acpi_os_free(buffer.pointer);
426         return_ACPI_STATUS(status);
427 }
428
429 static acpi_status
430 acpi_memory_register_notify_handler(acpi_handle handle,
431                                     u32 level, void *ctxt, void **retv)
432 {
433         acpi_status status;
434
435         ACPI_FUNCTION_TRACE("acpi_memory_register_notify_handler");
436
437         status = is_memory_device(handle);
438         if (ACPI_FAILURE(status))
439                 return_ACPI_STATUS(AE_OK);      /* continue */
440
441         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
442                                              acpi_memory_device_notify, NULL);
443         if (ACPI_FAILURE(status)) {
444                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
445                                   "Error installing notify handler\n"));
446                 return_ACPI_STATUS(AE_OK);      /* continue */
447         }
448
449         return_ACPI_STATUS(status);
450 }
451
452 static acpi_status
453 acpi_memory_deregister_notify_handler(acpi_handle handle,
454                                       u32 level, void *ctxt, void **retv)
455 {
456         acpi_status status;
457
458         ACPI_FUNCTION_TRACE("acpi_memory_deregister_notify_handler");
459
460         status = is_memory_device(handle);
461         if (ACPI_FAILURE(status))
462                 return_ACPI_STATUS(AE_OK);      /* continue */
463
464         status = acpi_remove_notify_handler(handle,
465                                             ACPI_SYSTEM_NOTIFY,
466                                             acpi_memory_device_notify);
467         if (ACPI_FAILURE(status)) {
468                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
469                                   "Error removing notify handler\n"));
470                 return_ACPI_STATUS(AE_OK);      /* continue */
471         }
472
473         return_ACPI_STATUS(status);
474 }
475
476 static int __init acpi_memory_device_init(void)
477 {
478         int result;
479         acpi_status status;
480
481         ACPI_FUNCTION_TRACE("acpi_memory_device_init");
482
483         result = acpi_bus_register_driver(&acpi_memory_device_driver);
484
485         if (result < 0)
486                 return_VALUE(-ENODEV);
487
488         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
489                                      ACPI_UINT32_MAX,
490                                      acpi_memory_register_notify_handler,
491                                      NULL, NULL);
492
493         if (ACPI_FAILURE(status)) {
494                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n"));
495                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
496                 return_VALUE(-ENODEV);
497         }
498
499         return_VALUE(0);
500 }
501
502 static void __exit acpi_memory_device_exit(void)
503 {
504         acpi_status status;
505
506         ACPI_FUNCTION_TRACE("acpi_memory_device_exit");
507
508         /*
509          * Adding this to un-install notification handlers for all the device
510          * handles.
511          */
512         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
513                                      ACPI_UINT32_MAX,
514                                      acpi_memory_deregister_notify_handler,
515                                      NULL, NULL);
516
517         if (ACPI_FAILURE(status))
518                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n"));
519
520         acpi_bus_unregister_driver(&acpi_memory_device_driver);
521
522         return_VOID;
523 }
524
525 module_init(acpi_memory_device_init);
526 module_exit(acpi_memory_device_exit);