Merge branch 'origin'
[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 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->caching =
101                             address64.info.mem.caching;
102                         mem_device->write_protect =
103                             address64.info.mem.write_protect;
104                         mem_device->start_addr = address64.minimum;
105                         mem_device->end_addr = address64.maximum;
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         if (result) {
205                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "\nadd_memory failed\n"));
206                 mem_device->state = MEMORY_INVALID_STATE;
207                 return result;
208         }
209
210         return result;
211 }
212
213 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
214 {
215         acpi_status status;
216         struct acpi_object_list arg_list;
217         union acpi_object arg;
218         unsigned long current_status;
219
220         ACPI_FUNCTION_TRACE("acpi_memory_powerdown_device");
221
222         /* Issue the _EJ0 command */
223         arg_list.count = 1;
224         arg_list.pointer = &arg;
225         arg.type = ACPI_TYPE_INTEGER;
226         arg.integer.value = 1;
227         status = acpi_evaluate_object(mem_device->handle,
228                                       "_EJ0", &arg_list, NULL);
229         /* Return on _EJ0 failure */
230         if (ACPI_FAILURE(status)) {
231                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "_EJ0 failed.\n"));
232                 return_VALUE(-ENODEV);
233         }
234
235         /* Evalute _STA to check if the device is disabled */
236         status = acpi_evaluate_integer(mem_device->handle, "_STA",
237                                        NULL, &current_status);
238         if (ACPI_FAILURE(status))
239                 return_VALUE(-ENODEV);
240
241         /* Check for device status.  Device should be disabled */
242         if (current_status & ACPI_MEMORY_STA_ENABLED)
243                 return_VALUE(-EINVAL);
244
245         return_VALUE(0);
246 }
247
248 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
249 {
250         int result;
251         u64 start = mem_device->start_addr;
252         u64 len = mem_device->end_addr - start + 1;
253
254         ACPI_FUNCTION_TRACE("acpi_memory_disable_device");
255
256         /*
257          * Ask the VM to offline this memory range.
258          * Note: Assume that this function returns zero on success
259          */
260         result = remove_memory(start, len);
261         if (result) {
262                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Hot-Remove failed.\n"));
263                 return_VALUE(result);
264         }
265
266         /* Power-off and eject the device */
267         result = acpi_memory_powerdown_device(mem_device);
268         if (result) {
269                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
270                                   "Device Power Down failed.\n"));
271                 /* Set the status of the device to invalid */
272                 mem_device->state = MEMORY_INVALID_STATE;
273                 return result;
274         }
275
276         mem_device->state = MEMORY_POWER_OFF_STATE;
277         return result;
278 }
279
280 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
281 {
282         struct acpi_memory_device *mem_device;
283         struct acpi_device *device;
284
285         ACPI_FUNCTION_TRACE("acpi_memory_device_notify");
286
287         switch (event) {
288         case ACPI_NOTIFY_BUS_CHECK:
289                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
290                                   "\nReceived BUS CHECK notification for device\n"));
291                 /* Fall Through */
292         case ACPI_NOTIFY_DEVICE_CHECK:
293                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
294                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
295                                           "\nReceived DEVICE CHECK notification for device\n"));
296                 if (acpi_memory_get_device(handle, &mem_device)) {
297                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
298                                           "Error in finding driver data\n"));
299                         return_VOID;
300                 }
301
302                 if (!acpi_memory_check_device(mem_device)) {
303                         if (acpi_memory_enable_device(mem_device))
304                                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
305                                                   "Error in acpi_memory_enable_device\n"));
306                 }
307                 break;
308         case ACPI_NOTIFY_EJECT_REQUEST:
309                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
310                                   "\nReceived EJECT REQUEST notification for device\n"));
311
312                 if (acpi_bus_get_device(handle, &device)) {
313                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
314                                           "Device doesn't exist\n"));
315                         break;
316                 }
317                 mem_device = acpi_driver_data(device);
318                 if (!mem_device) {
319                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
320                                           "Driver Data is NULL\n"));
321                         break;
322                 }
323
324                 /*
325                  * Currently disabling memory device from kernel mode
326                  * TBD: Can also be disabled from user mode scripts
327                  * TBD: Can also be disabled by Callback registration
328                  *      with generic sysfs driver
329                  */
330                 if (acpi_memory_disable_device(mem_device))
331                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
332                                           "Error in acpi_memory_disable_device\n"));
333                 /*
334                  * TBD: Invoke acpi_bus_remove to cleanup data structures
335                  */
336                 break;
337         default:
338                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
339                                   "Unsupported event [0x%x]\n", event));
340                 break;
341         }
342
343         return_VOID;
344 }
345
346 static int acpi_memory_device_add(struct acpi_device *device)
347 {
348         int result;
349         struct acpi_memory_device *mem_device = NULL;
350
351         ACPI_FUNCTION_TRACE("acpi_memory_device_add");
352
353         if (!device)
354                 return_VALUE(-EINVAL);
355
356         mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
357         if (!mem_device)
358                 return_VALUE(-ENOMEM);
359         memset(mem_device, 0, sizeof(struct acpi_memory_device));
360
361         mem_device->handle = device->handle;
362         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
363         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
364         acpi_driver_data(device) = mem_device;
365
366         /* Get the range from the _CRS */
367         result = acpi_memory_get_device_resources(mem_device);
368         if (result) {
369                 kfree(mem_device);
370                 return_VALUE(result);
371         }
372
373         /* Set the device state */
374         mem_device->state = MEMORY_POWER_ON_STATE;
375
376         printk(KERN_INFO "%s \n", acpi_device_name(device));
377
378         return_VALUE(result);
379 }
380
381 static int acpi_memory_device_remove(struct acpi_device *device, int type)
382 {
383         struct acpi_memory_device *mem_device = NULL;
384
385         ACPI_FUNCTION_TRACE("acpi_memory_device_remove");
386
387         if (!device || !acpi_driver_data(device))
388                 return_VALUE(-EINVAL);
389
390         mem_device = (struct acpi_memory_device *)acpi_driver_data(device);
391         kfree(mem_device);
392
393         return_VALUE(0);
394 }
395
396 /*
397  * Helper function to check for memory device
398  */
399 static acpi_status is_memory_device(acpi_handle handle)
400 {
401         char *hardware_id;
402         acpi_status status;
403         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
404         struct acpi_device_info *info;
405
406         ACPI_FUNCTION_TRACE("is_memory_device");
407
408         status = acpi_get_object_info(handle, &buffer);
409         if (ACPI_FAILURE(status))
410                 return_ACPI_STATUS(AE_ERROR);
411
412         info = buffer.pointer;
413         if (!(info->valid & ACPI_VALID_HID)) {
414                 acpi_os_free(buffer.pointer);
415                 return_ACPI_STATUS(AE_ERROR);
416         }
417
418         hardware_id = info->hardware_id.value;
419         if ((hardware_id == NULL) ||
420             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
421                 status = AE_ERROR;
422
423         acpi_os_free(buffer.pointer);
424         return_ACPI_STATUS(status);
425 }
426
427 static acpi_status
428 acpi_memory_register_notify_handler(acpi_handle handle,
429                                     u32 level, void *ctxt, void **retv)
430 {
431         acpi_status status;
432
433         ACPI_FUNCTION_TRACE("acpi_memory_register_notify_handler");
434
435         status = is_memory_device(handle);
436         if (ACPI_FAILURE(status))
437                 return_ACPI_STATUS(AE_OK);      /* continue */
438
439         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
440                                              acpi_memory_device_notify, NULL);
441         if (ACPI_FAILURE(status)) {
442                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
443                                   "Error installing notify handler\n"));
444                 return_ACPI_STATUS(AE_OK);      /* continue */
445         }
446
447         return_ACPI_STATUS(status);
448 }
449
450 static acpi_status
451 acpi_memory_deregister_notify_handler(acpi_handle handle,
452                                       u32 level, void *ctxt, void **retv)
453 {
454         acpi_status status;
455
456         ACPI_FUNCTION_TRACE("acpi_memory_deregister_notify_handler");
457
458         status = is_memory_device(handle);
459         if (ACPI_FAILURE(status))
460                 return_ACPI_STATUS(AE_OK);      /* continue */
461
462         status = acpi_remove_notify_handler(handle,
463                                             ACPI_SYSTEM_NOTIFY,
464                                             acpi_memory_device_notify);
465         if (ACPI_FAILURE(status)) {
466                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
467                                   "Error removing notify handler\n"));
468                 return_ACPI_STATUS(AE_OK);      /* continue */
469         }
470
471         return_ACPI_STATUS(status);
472 }
473
474 static int __init acpi_memory_device_init(void)
475 {
476         int result;
477         acpi_status status;
478
479         ACPI_FUNCTION_TRACE("acpi_memory_device_init");
480
481         result = acpi_bus_register_driver(&acpi_memory_device_driver);
482
483         if (result < 0)
484                 return_VALUE(-ENODEV);
485
486         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
487                                      ACPI_UINT32_MAX,
488                                      acpi_memory_register_notify_handler,
489                                      NULL, NULL);
490
491         if (ACPI_FAILURE(status)) {
492                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n"));
493                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
494                 return_VALUE(-ENODEV);
495         }
496
497         return_VALUE(0);
498 }
499
500 static void __exit acpi_memory_device_exit(void)
501 {
502         acpi_status status;
503
504         ACPI_FUNCTION_TRACE("acpi_memory_device_exit");
505
506         /*
507          * Adding this to un-install notification handlers for all the device
508          * handles.
509          */
510         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
511                                      ACPI_UINT32_MAX,
512                                      acpi_memory_deregister_notify_handler,
513                                      NULL, NULL);
514
515         if (ACPI_FAILURE(status))
516                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n"));
517
518         acpi_bus_unregister_driver(&acpi_memory_device_driver);
519
520         return_VOID;
521 }
522
523 module_init(acpi_memory_device_init);
524 module_exit(acpi_memory_device_exit);