Merge git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
[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 static int acpi_memory_device_start(struct acpi_device *device);
61
62 static struct acpi_driver acpi_memory_device_driver = {
63         .name = ACPI_MEMORY_DEVICE_DRIVER_NAME,
64         .class = ACPI_MEMORY_DEVICE_CLASS,
65         .ids = ACPI_MEMORY_DEVICE_HID,
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         acpi_handle handle;
84         unsigned int state;     /* State of the memory device */
85         struct list_head res_list;
86 };
87
88 static acpi_status
89 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
90 {
91         struct acpi_memory_device *mem_device = context;
92         struct acpi_resource_address64 address64;
93         struct acpi_memory_info *info, *new;
94         acpi_status status;
95
96         status = acpi_resource_to_address64(resource, &address64);
97         if (ACPI_FAILURE(status) ||
98             (address64.resource_type != ACPI_MEMORY_RANGE))
99                 return AE_OK;
100
101         list_for_each_entry(info, &mem_device->res_list, list) {
102                 /* Can we combine the resource range information? */
103                 if ((info->caching == address64.info.mem.caching) &&
104                     (info->write_protect == address64.info.mem.write_protect) &&
105                     (info->start_addr + info->length == address64.minimum)) {
106                         info->length += address64.address_length;
107                         return AE_OK;
108                 }
109         }
110
111         new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
112         if (!new)
113                 return AE_ERROR;
114
115         INIT_LIST_HEAD(&new->list);
116         new->caching = address64.info.mem.caching;
117         new->write_protect = address64.info.mem.write_protect;
118         new->start_addr = address64.minimum;
119         new->length = address64.address_length;
120         list_add_tail(&new->list, &mem_device->res_list);
121
122         return AE_OK;
123 }
124
125 static int
126 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
127 {
128         acpi_status status;
129         struct acpi_memory_info *info, *n;
130
131         ACPI_FUNCTION_TRACE("acpi_memory_get_device_resources");
132
133         status = acpi_walk_resources(mem_device->handle, METHOD_NAME__CRS,
134                                      acpi_memory_get_resource, mem_device);
135         if (ACPI_FAILURE(status)) {
136                 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
137                         kfree(info);
138                 return -EINVAL;
139         }
140
141         return 0;
142 }
143
144 static int
145 acpi_memory_get_device(acpi_handle handle,
146                        struct acpi_memory_device **mem_device)
147 {
148         acpi_status status;
149         acpi_handle phandle;
150         struct acpi_device *device = NULL;
151         struct acpi_device *pdevice = NULL;
152
153         ACPI_FUNCTION_TRACE("acpi_memory_get_device");
154
155         if (!acpi_bus_get_device(handle, &device) && device)
156                 goto end;
157
158         status = acpi_get_parent(handle, &phandle);
159         if (ACPI_FAILURE(status)) {
160                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error in acpi_get_parent\n"));
161                 return_VALUE(-EINVAL);
162         }
163
164         /* Get the parent device */
165         status = acpi_bus_get_device(phandle, &pdevice);
166         if (ACPI_FAILURE(status)) {
167                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
168                                   "Error in acpi_bus_get_device\n"));
169                 return_VALUE(-EINVAL);
170         }
171
172         /*
173          * Now add the notified device.  This creates the acpi_device
174          * and invokes .add function
175          */
176         status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
177         if (ACPI_FAILURE(status)) {
178                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error in acpi_bus_add\n"));
179                 return_VALUE(-EINVAL);
180         }
181
182       end:
183         *mem_device = acpi_driver_data(device);
184         if (!(*mem_device)) {
185                 printk(KERN_ERR "\n driver data not found");
186                 return_VALUE(-ENODEV);
187         }
188
189         return_VALUE(0);
190 }
191
192 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
193 {
194         unsigned long current_status;
195
196         ACPI_FUNCTION_TRACE("acpi_memory_check_device");
197
198         /* Get device present/absent information from the _STA */
199         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->handle, "_STA",
200                                                NULL, &current_status)))
201                 return_VALUE(-ENODEV);
202         /*
203          * Check for device status. Device should be
204          * present/enabled/functioning.
205          */
206         if (!((current_status & ACPI_MEMORY_STA_PRESENT)
207               && (current_status & ACPI_MEMORY_STA_ENABLED)
208               && (current_status & ACPI_MEMORY_STA_FUNCTIONAL)))
209                 return_VALUE(-ENODEV);
210
211         return_VALUE(0);
212 }
213
214 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
215 {
216         int result, num_enabled = 0;
217         struct acpi_memory_info *info;
218         int node;
219
220         ACPI_FUNCTION_TRACE("acpi_memory_enable_device");
221
222         /* Get the range from the _CRS */
223         result = acpi_memory_get_device_resources(mem_device);
224         if (result) {
225                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
226                                   "\nget_device_resources failed\n"));
227                 mem_device->state = MEMORY_INVALID_STATE;
228                 return result;
229         }
230
231         node = acpi_get_node(mem_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                 u64 start_pfn, end_pfn;
240
241                 start_pfn = info->start_addr >> PAGE_SHIFT;
242                 end_pfn = (info->start_addr + info->length - 1) >> PAGE_SHIFT;
243
244                 if (pfn_valid(start_pfn) || pfn_valid(end_pfn)) {
245                         /* already enabled. try next area */
246                         num_enabled++;
247                         continue;
248                 }
249
250                 result = add_memory(node, info->start_addr, info->length);
251                 if (result)
252                         continue;
253                 info->enabled = 1;
254                 num_enabled++;
255         }
256         if (!num_enabled) {
257                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "\nadd_memory failed\n"));
258                 mem_device->state = MEMORY_INVALID_STATE;
259                 return -EINVAL;
260         }
261
262         return result;
263 }
264
265 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
266 {
267         acpi_status status;
268         struct acpi_object_list arg_list;
269         union acpi_object arg;
270         unsigned long current_status;
271
272         ACPI_FUNCTION_TRACE("acpi_memory_powerdown_device");
273
274         /* Issue the _EJ0 command */
275         arg_list.count = 1;
276         arg_list.pointer = &arg;
277         arg.type = ACPI_TYPE_INTEGER;
278         arg.integer.value = 1;
279         status = acpi_evaluate_object(mem_device->handle,
280                                       "_EJ0", &arg_list, NULL);
281         /* Return on _EJ0 failure */
282         if (ACPI_FAILURE(status)) {
283                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "_EJ0 failed.\n"));
284                 return_VALUE(-ENODEV);
285         }
286
287         /* Evalute _STA to check if the device is disabled */
288         status = acpi_evaluate_integer(mem_device->handle, "_STA",
289                                        NULL, &current_status);
290         if (ACPI_FAILURE(status))
291                 return_VALUE(-ENODEV);
292
293         /* Check for device status.  Device should be disabled */
294         if (current_status & ACPI_MEMORY_STA_ENABLED)
295                 return_VALUE(-EINVAL);
296
297         return_VALUE(0);
298 }
299
300 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
301 {
302         int result;
303         struct acpi_memory_info *info, *n;
304
305         ACPI_FUNCTION_TRACE("acpi_memory_disable_device");
306
307         /*
308          * Ask the VM to offline this memory range.
309          * Note: Assume that this function returns zero on success
310          */
311         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
312                 if (info->enabled) {
313                         result = remove_memory(info->start_addr, info->length);
314                         if (result)
315                                 return result;
316                 }
317                 kfree(info);
318         }
319
320         /* Power-off and eject the device */
321         result = acpi_memory_powerdown_device(mem_device);
322         if (result) {
323                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
324                                   "Device Power Down failed.\n"));
325                 /* Set the status of the device to invalid */
326                 mem_device->state = MEMORY_INVALID_STATE;
327                 return result;
328         }
329
330         mem_device->state = MEMORY_POWER_OFF_STATE;
331         return result;
332 }
333
334 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
335 {
336         struct acpi_memory_device *mem_device;
337         struct acpi_device *device;
338
339         ACPI_FUNCTION_TRACE("acpi_memory_device_notify");
340
341         switch (event) {
342         case ACPI_NOTIFY_BUS_CHECK:
343                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
344                                   "\nReceived BUS CHECK notification for device\n"));
345                 /* Fall Through */
346         case ACPI_NOTIFY_DEVICE_CHECK:
347                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
348                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
349                                           "\nReceived DEVICE CHECK notification for device\n"));
350                 if (acpi_memory_get_device(handle, &mem_device)) {
351                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
352                                           "Error in finding driver data\n"));
353                         return_VOID;
354                 }
355
356                 if (!acpi_memory_check_device(mem_device)) {
357                         if (acpi_memory_enable_device(mem_device))
358                                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
359                                                   "Error in acpi_memory_enable_device\n"));
360                 }
361                 break;
362         case ACPI_NOTIFY_EJECT_REQUEST:
363                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
364                                   "\nReceived EJECT REQUEST notification for device\n"));
365
366                 if (acpi_bus_get_device(handle, &device)) {
367                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
368                                           "Device doesn't exist\n"));
369                         break;
370                 }
371                 mem_device = acpi_driver_data(device);
372                 if (!mem_device) {
373                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
374                                           "Driver Data is NULL\n"));
375                         break;
376                 }
377
378                 /*
379                  * Currently disabling memory device from kernel mode
380                  * TBD: Can also be disabled from user mode scripts
381                  * TBD: Can also be disabled by Callback registration
382                  *      with generic sysfs driver
383                  */
384                 if (acpi_memory_disable_device(mem_device))
385                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
386                                           "Error in acpi_memory_disable_device\n"));
387                 /*
388                  * TBD: Invoke acpi_bus_remove to cleanup data structures
389                  */
390                 break;
391         default:
392                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
393                                   "Unsupported event [0x%x]\n", event));
394                 break;
395         }
396
397         return_VOID;
398 }
399
400 static int acpi_memory_device_add(struct acpi_device *device)
401 {
402         int result;
403         struct acpi_memory_device *mem_device = NULL;
404
405         ACPI_FUNCTION_TRACE("acpi_memory_device_add");
406
407         if (!device)
408                 return_VALUE(-EINVAL);
409
410         mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
411         if (!mem_device)
412                 return_VALUE(-ENOMEM);
413         memset(mem_device, 0, sizeof(struct acpi_memory_device));
414
415         INIT_LIST_HEAD(&mem_device->res_list);
416         mem_device->handle = device->handle;
417         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
418         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
419         acpi_driver_data(device) = mem_device;
420
421         /* Get the range from the _CRS */
422         result = acpi_memory_get_device_resources(mem_device);
423         if (result) {
424                 kfree(mem_device);
425                 return_VALUE(result);
426         }
427
428         /* Set the device state */
429         mem_device->state = MEMORY_POWER_ON_STATE;
430
431         printk(KERN_INFO "%s \n", acpi_device_name(device));
432
433         return_VALUE(result);
434 }
435
436 static int acpi_memory_device_remove(struct acpi_device *device, int type)
437 {
438         struct acpi_memory_device *mem_device = NULL;
439
440         ACPI_FUNCTION_TRACE("acpi_memory_device_remove");
441
442         if (!device || !acpi_driver_data(device))
443                 return_VALUE(-EINVAL);
444
445         mem_device = (struct acpi_memory_device *)acpi_driver_data(device);
446         kfree(mem_device);
447
448         return_VALUE(0);
449 }
450
451 static int acpi_memory_device_start (struct acpi_device *device)
452 {
453         struct acpi_memory_device *mem_device;
454         int result = 0;
455
456         ACPI_FUNCTION_TRACE("acpi_memory_device_start");
457
458         mem_device = acpi_driver_data(device);
459
460         if (!acpi_memory_check_device(mem_device)) {
461                 /* call add_memory func */
462                 result = acpi_memory_enable_device(mem_device);
463                 if (result)
464                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
465                                 "Error in acpi_memory_enable_device\n"));
466         }
467         return_VALUE(result);
468 }
469
470 /*
471  * Helper function to check for memory device
472  */
473 static acpi_status is_memory_device(acpi_handle handle)
474 {
475         char *hardware_id;
476         acpi_status status;
477         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
478         struct acpi_device_info *info;
479
480         ACPI_FUNCTION_TRACE("is_memory_device");
481
482         status = acpi_get_object_info(handle, &buffer);
483         if (ACPI_FAILURE(status))
484                 return_ACPI_STATUS(AE_ERROR);
485
486         info = buffer.pointer;
487         if (!(info->valid & ACPI_VALID_HID)) {
488                 acpi_os_free(buffer.pointer);
489                 return_ACPI_STATUS(AE_ERROR);
490         }
491
492         hardware_id = info->hardware_id.value;
493         if ((hardware_id == NULL) ||
494             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
495                 status = AE_ERROR;
496
497         acpi_os_free(buffer.pointer);
498         return_ACPI_STATUS(status);
499 }
500
501 static acpi_status
502 acpi_memory_register_notify_handler(acpi_handle handle,
503                                     u32 level, void *ctxt, void **retv)
504 {
505         acpi_status status;
506
507         ACPI_FUNCTION_TRACE("acpi_memory_register_notify_handler");
508
509         status = is_memory_device(handle);
510         if (ACPI_FAILURE(status))
511                 return_ACPI_STATUS(AE_OK);      /* continue */
512
513         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
514                                              acpi_memory_device_notify, NULL);
515         if (ACPI_FAILURE(status)) {
516                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
517                                   "Error installing notify handler\n"));
518                 return_ACPI_STATUS(AE_OK);      /* continue */
519         }
520
521         return_ACPI_STATUS(status);
522 }
523
524 static acpi_status
525 acpi_memory_deregister_notify_handler(acpi_handle handle,
526                                       u32 level, void *ctxt, void **retv)
527 {
528         acpi_status status;
529
530         ACPI_FUNCTION_TRACE("acpi_memory_deregister_notify_handler");
531
532         status = is_memory_device(handle);
533         if (ACPI_FAILURE(status))
534                 return_ACPI_STATUS(AE_OK);      /* continue */
535
536         status = acpi_remove_notify_handler(handle,
537                                             ACPI_SYSTEM_NOTIFY,
538                                             acpi_memory_device_notify);
539         if (ACPI_FAILURE(status)) {
540                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
541                                   "Error removing notify handler\n"));
542                 return_ACPI_STATUS(AE_OK);      /* continue */
543         }
544
545         return_ACPI_STATUS(status);
546 }
547
548 static int __init acpi_memory_device_init(void)
549 {
550         int result;
551         acpi_status status;
552
553         ACPI_FUNCTION_TRACE("acpi_memory_device_init");
554
555         result = acpi_bus_register_driver(&acpi_memory_device_driver);
556
557         if (result < 0)
558                 return_VALUE(-ENODEV);
559
560         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
561                                      ACPI_UINT32_MAX,
562                                      acpi_memory_register_notify_handler,
563                                      NULL, NULL);
564
565         if (ACPI_FAILURE(status)) {
566                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n"));
567                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
568                 return_VALUE(-ENODEV);
569         }
570
571         return_VALUE(0);
572 }
573
574 static void __exit acpi_memory_device_exit(void)
575 {
576         acpi_status status;
577
578         ACPI_FUNCTION_TRACE("acpi_memory_device_exit");
579
580         /*
581          * Adding this to un-install notification handlers for all the device
582          * handles.
583          */
584         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
585                                      ACPI_UINT32_MAX,
586                                      acpi_memory_deregister_notify_handler,
587                                      NULL, NULL);
588
589         if (ACPI_FAILURE(status))
590                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n"));
591
592         acpi_bus_unregister_driver(&acpi_memory_device_driver);
593
594         return_VOID;
595 }
596
597 module_init(acpi_memory_device_init);
598 module_exit(acpi_memory_device_exit);