c7c8d537a063e26bf65b0f278e85f7e39e2b0a86
[linux-2.6.git] / 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_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
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_EXCEPTION((AE_INFO, status, "Cannot get acpi bus device"));
136                 return_VALUE(-EINVAL);
137         }
138
139         /*
140          * Now add the notified device.  This creates the acpi_device
141          * and invokes .add function
142          */
143         status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
144         if (ACPI_FAILURE(status)) {
145                 ACPI_EXCEPTION((AE_INFO, status, "Cannot add acpi bus"));
146                 return_VALUE(-EINVAL);
147         }
148
149       end:
150         *mem_device = acpi_driver_data(device);
151         if (!(*mem_device)) {
152                 printk(KERN_ERR "\n driver data not found");
153                 return_VALUE(-ENODEV);
154         }
155
156         return_VALUE(0);
157 }
158
159 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
160 {
161         unsigned long current_status;
162
163         ACPI_FUNCTION_TRACE("acpi_memory_check_device");
164
165         /* Get device present/absent information from the _STA */
166         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->handle, "_STA",
167                                                NULL, &current_status)))
168                 return_VALUE(-ENODEV);
169         /*
170          * Check for device status. Device should be
171          * present/enabled/functioning.
172          */
173         if (!((current_status & ACPI_MEMORY_STA_PRESENT)
174               && (current_status & ACPI_MEMORY_STA_ENABLED)
175               && (current_status & ACPI_MEMORY_STA_FUNCTIONAL)))
176                 return_VALUE(-ENODEV);
177
178         return_VALUE(0);
179 }
180
181 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
182 {
183         int result;
184
185         ACPI_FUNCTION_TRACE("acpi_memory_enable_device");
186
187         /* Get the range from the _CRS */
188         result = acpi_memory_get_device_resources(mem_device);
189         if (result) {
190                 printk(KERN_ERR PREFIX "get_device_resources failed\n");
191                 mem_device->state = MEMORY_INVALID_STATE;
192                 return result;
193         }
194
195         /*
196          * Tell the VM there is more memory here...
197          * Note: Assume that this function returns zero on success
198          */
199         result = add_memory(mem_device->start_addr, mem_device->length);
200         if (result) {
201                 printk(KERN_ERR PREFIX "add_memory failed\n");
202                 mem_device->state = MEMORY_INVALID_STATE;
203                 return result;
204         }
205
206         return result;
207 }
208
209 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
210 {
211         acpi_status status;
212         struct acpi_object_list arg_list;
213         union acpi_object arg;
214         unsigned long current_status;
215
216         ACPI_FUNCTION_TRACE("acpi_memory_powerdown_device");
217
218         /* Issue the _EJ0 command */
219         arg_list.count = 1;
220         arg_list.pointer = &arg;
221         arg.type = ACPI_TYPE_INTEGER;
222         arg.integer.value = 1;
223         status = acpi_evaluate_object(mem_device->handle,
224                                       "_EJ0", &arg_list, NULL);
225         /* Return on _EJ0 failure */
226         if (ACPI_FAILURE(status)) {
227                 ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
228                 return_VALUE(-ENODEV);
229         }
230
231         /* Evalute _STA to check if the device is disabled */
232         status = acpi_evaluate_integer(mem_device->handle, "_STA",
233                                        NULL, &current_status);
234         if (ACPI_FAILURE(status))
235                 return_VALUE(-ENODEV);
236
237         /* Check for device status.  Device should be disabled */
238         if (current_status & ACPI_MEMORY_STA_ENABLED)
239                 return_VALUE(-EINVAL);
240
241         return_VALUE(0);
242 }
243
244 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
245 {
246         int result;
247         u64 start = mem_device->start_addr;
248         u64 len = mem_device->length;
249
250         ACPI_FUNCTION_TRACE("acpi_memory_disable_device");
251
252         /*
253          * Ask the VM to offline this memory range.
254          * Note: Assume that this function returns zero on success
255          */
256         result = remove_memory(start, len);
257         if (result)
258                 return_VALUE(result);
259
260         /* Power-off and eject the device */
261         result = acpi_memory_powerdown_device(mem_device);
262         if (result) {
263                 /* Set the status of the device to invalid */
264                 mem_device->state = MEMORY_INVALID_STATE;
265                 return result;
266         }
267
268         mem_device->state = MEMORY_POWER_OFF_STATE;
269         return result;
270 }
271
272 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
273 {
274         struct acpi_memory_device *mem_device;
275         struct acpi_device *device;
276
277         ACPI_FUNCTION_TRACE("acpi_memory_device_notify");
278
279         switch (event) {
280         case ACPI_NOTIFY_BUS_CHECK:
281                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
282                                   "\nReceived BUS CHECK notification for device\n"));
283                 /* Fall Through */
284         case ACPI_NOTIFY_DEVICE_CHECK:
285                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
286                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
287                                           "\nReceived DEVICE CHECK notification for device\n"));
288                 if (acpi_memory_get_device(handle, &mem_device)) {
289                         printk(KERN_ERR PREFIX "Cannot find driver data\n");
290                         return_VOID;
291                 }
292
293                 if (!acpi_memory_check_device(mem_device)) {
294                         if (acpi_memory_enable_device(mem_device))
295                                 printk(KERN_ERR PREFIX
296                                             "Cannot enable memory device\n");
297                 }
298                 break;
299         case ACPI_NOTIFY_EJECT_REQUEST:
300                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
301                                   "\nReceived EJECT REQUEST notification for device\n"));
302
303                 if (acpi_bus_get_device(handle, &device)) {
304                         printk(KERN_ERR PREFIX "Device doesn't exist\n");
305                         break;
306                 }
307                 mem_device = acpi_driver_data(device);
308                 if (!mem_device) {
309                         printk(KERN_ERR PREFIX "Driver Data is NULL\n");
310                         break;
311                 }
312
313                 /*
314                  * Currently disabling memory device from kernel mode
315                  * TBD: Can also be disabled from user mode scripts
316                  * TBD: Can also be disabled by Callback registration
317                  *      with generic sysfs driver
318                  */
319                 if (acpi_memory_disable_device(mem_device))
320                         printk(KERN_ERR PREFIX
321                                     "Disable memory device\n");
322                 /*
323                  * TBD: Invoke acpi_bus_remove to cleanup data structures
324                  */
325                 break;
326         default:
327                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
328                                   "Unsupported event [0x%x]\n", event));
329                 break;
330         }
331
332         return_VOID;
333 }
334
335 static int acpi_memory_device_add(struct acpi_device *device)
336 {
337         int result;
338         struct acpi_memory_device *mem_device = NULL;
339
340         ACPI_FUNCTION_TRACE("acpi_memory_device_add");
341
342         if (!device)
343                 return_VALUE(-EINVAL);
344
345         mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
346         if (!mem_device)
347                 return_VALUE(-ENOMEM);
348         memset(mem_device, 0, sizeof(struct acpi_memory_device));
349
350         mem_device->handle = device->handle;
351         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
352         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
353         acpi_driver_data(device) = mem_device;
354
355         /* Get the range from the _CRS */
356         result = acpi_memory_get_device_resources(mem_device);
357         if (result) {
358                 kfree(mem_device);
359                 return_VALUE(result);
360         }
361
362         /* Set the device state */
363         mem_device->state = MEMORY_POWER_ON_STATE;
364
365         printk(KERN_INFO "%s \n", acpi_device_name(device));
366
367         return_VALUE(result);
368 }
369
370 static int acpi_memory_device_remove(struct acpi_device *device, int type)
371 {
372         struct acpi_memory_device *mem_device = NULL;
373
374         ACPI_FUNCTION_TRACE("acpi_memory_device_remove");
375
376         if (!device || !acpi_driver_data(device))
377                 return_VALUE(-EINVAL);
378
379         mem_device = (struct acpi_memory_device *)acpi_driver_data(device);
380         kfree(mem_device);
381
382         return_VALUE(0);
383 }
384
385 /*
386  * Helper function to check for memory device
387  */
388 static acpi_status is_memory_device(acpi_handle handle)
389 {
390         char *hardware_id;
391         acpi_status status;
392         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
393         struct acpi_device_info *info;
394
395         ACPI_FUNCTION_TRACE("is_memory_device");
396
397         status = acpi_get_object_info(handle, &buffer);
398         if (ACPI_FAILURE(status))
399                 return_ACPI_STATUS(status);
400
401         info = buffer.pointer;
402         if (!(info->valid & ACPI_VALID_HID)) {
403                 acpi_os_free(buffer.pointer);
404                 return_ACPI_STATUS(AE_ERROR);
405         }
406
407         hardware_id = info->hardware_id.value;
408         if ((hardware_id == NULL) ||
409             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
410                 status = AE_ERROR;
411
412         acpi_os_free(buffer.pointer);
413         return_ACPI_STATUS(status);
414 }
415
416 static acpi_status
417 acpi_memory_register_notify_handler(acpi_handle handle,
418                                     u32 level, void *ctxt, void **retv)
419 {
420         acpi_status status;
421
422         ACPI_FUNCTION_TRACE("acpi_memory_register_notify_handler");
423
424         status = is_memory_device(handle);
425         if (ACPI_FAILURE(status)){
426                 ACPI_EXCEPTION((AE_INFO, status, "handle is no memory device"));
427                 return_ACPI_STATUS(AE_OK);      /* continue */
428         }
429
430         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
431                                              acpi_memory_device_notify, NULL);
432         /* continue */
433         return_ACPI_STATUS(AE_OK);
434 }
435
436 static acpi_status
437 acpi_memory_deregister_notify_handler(acpi_handle handle,
438                                       u32 level, void *ctxt, void **retv)
439 {
440         acpi_status status;
441
442         ACPI_FUNCTION_TRACE("acpi_memory_deregister_notify_handler");
443
444         status = is_memory_device(handle);
445         if (ACPI_FAILURE(status)){
446                 ACPI_EXCEPTION((AE_INFO, status, "handle is no memory device"));
447                 return_ACPI_STATUS(AE_OK);      /* continue */
448         }
449
450         status = acpi_remove_notify_handler(handle,
451                                             ACPI_SYSTEM_NOTIFY,
452                                             acpi_memory_device_notify);
453
454         return_ACPI_STATUS(AE_OK);      /* continue */
455 }
456
457 static int __init acpi_memory_device_init(void)
458 {
459         int result;
460         acpi_status status;
461
462         ACPI_FUNCTION_TRACE("acpi_memory_device_init");
463
464         result = acpi_bus_register_driver(&acpi_memory_device_driver);
465
466         if (result < 0)
467                 return_VALUE(-ENODEV);
468
469         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
470                                      ACPI_UINT32_MAX,
471                                      acpi_memory_register_notify_handler,
472                                      NULL, NULL);
473
474         if (ACPI_FAILURE(status)) {
475                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
476                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
477                 return_VALUE(-ENODEV);
478         }
479
480         return_VALUE(0);
481 }
482
483 static void __exit acpi_memory_device_exit(void)
484 {
485         acpi_status status;
486
487         ACPI_FUNCTION_TRACE("acpi_memory_device_exit");
488
489         /*
490          * Adding this to un-install notification handlers for all the device
491          * handles.
492          */
493         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
494                                      ACPI_UINT32_MAX,
495                                      acpi_memory_deregister_notify_handler,
496                                      NULL, NULL);
497
498         if (ACPI_FAILURE(status))
499                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
500
501         acpi_bus_unregister_driver(&acpi_memory_device_driver);
502
503         return_VOID;
504 }
505
506 module_init(acpi_memory_device_init);
507 module_exit(acpi_memory_device_exit);