Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm
[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         struct acpi_device * device;
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
132         if (!list_empty(&mem_device->res_list))
133                 return 0;
134
135         status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
136                                      acpi_memory_get_resource, mem_device);
137         if (ACPI_FAILURE(status)) {
138                 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
139                         kfree(info);
140                 INIT_LIST_HEAD(&mem_device->res_list);
141                 return -EINVAL;
142         }
143
144         return 0;
145 }
146
147 static int
148 acpi_memory_get_device(acpi_handle handle,
149                        struct acpi_memory_device **mem_device)
150 {
151         acpi_status status;
152         acpi_handle phandle;
153         struct acpi_device *device = NULL;
154         struct acpi_device *pdevice = NULL;
155
156
157         if (!acpi_bus_get_device(handle, &device) && device)
158                 goto end;
159
160         status = acpi_get_parent(handle, &phandle);
161         if (ACPI_FAILURE(status)) {
162                 ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
163                 return -EINVAL;
164         }
165
166         /* Get the parent device */
167         status = acpi_bus_get_device(phandle, &pdevice);
168         if (ACPI_FAILURE(status)) {
169                 ACPI_EXCEPTION((AE_INFO, status, "Cannot get acpi bus device"));
170                 return -EINVAL;
171         }
172
173         /*
174          * Now add the notified device.  This creates the acpi_device
175          * and invokes .add function
176          */
177         status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
178         if (ACPI_FAILURE(status)) {
179                 ACPI_EXCEPTION((AE_INFO, status, "Cannot add acpi bus"));
180                 return -EINVAL;
181         }
182
183       end:
184         *mem_device = acpi_driver_data(device);
185         if (!(*mem_device)) {
186                 printk(KERN_ERR "\n driver data not found");
187                 return -ENODEV;
188         }
189
190         return 0;
191 }
192
193 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
194 {
195         unsigned long current_status;
196
197
198         /* Get device present/absent information from the _STA */
199         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
200                                                NULL, &current_status)))
201                 return -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 -ENODEV;
210
211         return 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
221         /* Get the range from the _CRS */
222         result = acpi_memory_get_device_resources(mem_device);
223         if (result) {
224                 printk(KERN_ERR PREFIX "get_device_resources failed\n");
225                 mem_device->state = MEMORY_INVALID_STATE;
226                 return result;
227         }
228
229         node = acpi_get_node(mem_device->device->handle);
230         /*
231          * Tell the VM there is more memory here...
232          * Note: Assume that this function returns zero on success
233          * We don't have memory-hot-add rollback function,now.
234          * (i.e. memory-hot-remove function)
235          */
236         list_for_each_entry(info, &mem_device->res_list, list) {
237                 if (info->enabled) { /* just sanity check...*/
238                         num_enabled++;
239                         continue;
240                 }
241
242                 if (node < 0)
243                         node = memory_add_physaddr_to_nid(info->start_addr);
244
245                 result = add_memory(node, info->start_addr, info->length);
246                 if (result)
247                         continue;
248                 info->enabled = 1;
249                 num_enabled++;
250         }
251         if (!num_enabled) {
252                 printk(KERN_ERR PREFIX "add_memory failed\n");
253                 mem_device->state = MEMORY_INVALID_STATE;
254                 return -EINVAL;
255         }
256
257         return result;
258 }
259
260 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
261 {
262         acpi_status status;
263         struct acpi_object_list arg_list;
264         union acpi_object arg;
265         unsigned long current_status;
266
267
268         /* Issue the _EJ0 command */
269         arg_list.count = 1;
270         arg_list.pointer = &arg;
271         arg.type = ACPI_TYPE_INTEGER;
272         arg.integer.value = 1;
273         status = acpi_evaluate_object(mem_device->device->handle,
274                                       "_EJ0", &arg_list, NULL);
275         /* Return on _EJ0 failure */
276         if (ACPI_FAILURE(status)) {
277                 ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
278                 return -ENODEV;
279         }
280
281         /* Evalute _STA to check if the device is disabled */
282         status = acpi_evaluate_integer(mem_device->device->handle, "_STA",
283                                        NULL, &current_status);
284         if (ACPI_FAILURE(status))
285                 return -ENODEV;
286
287         /* Check for device status.  Device should be disabled */
288         if (current_status & ACPI_MEMORY_STA_ENABLED)
289                 return -EINVAL;
290
291         return 0;
292 }
293
294 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
295 {
296         int result;
297         struct acpi_memory_info *info, *n;
298
299
300         /*
301          * Ask the VM to offline this memory range.
302          * Note: Assume that this function returns zero on success
303          */
304         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
305                 if (info->enabled) {
306                         result = remove_memory(info->start_addr, info->length);
307                         if (result)
308                                 return result;
309                 }
310                 kfree(info);
311         }
312
313         /* Power-off and eject the device */
314         result = acpi_memory_powerdown_device(mem_device);
315         if (result) {
316                 /* Set the status of the device to invalid */
317                 mem_device->state = MEMORY_INVALID_STATE;
318                 return result;
319         }
320
321         mem_device->state = MEMORY_POWER_OFF_STATE;
322         return result;
323 }
324
325 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
326 {
327         struct acpi_memory_device *mem_device;
328         struct acpi_device *device;
329
330
331         switch (event) {
332         case ACPI_NOTIFY_BUS_CHECK:
333                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
334                                   "\nReceived BUS CHECK notification for device\n"));
335                 /* Fall Through */
336         case ACPI_NOTIFY_DEVICE_CHECK:
337                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
338                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
339                                           "\nReceived DEVICE CHECK notification for device\n"));
340                 if (acpi_memory_get_device(handle, &mem_device)) {
341                         printk(KERN_ERR PREFIX "Cannot find driver data\n");
342                         return;
343                 }
344
345                 if (!acpi_memory_check_device(mem_device)) {
346                         if (acpi_memory_enable_device(mem_device))
347                                 printk(KERN_ERR PREFIX
348                                             "Cannot enable memory device\n");
349                 }
350                 break;
351         case ACPI_NOTIFY_EJECT_REQUEST:
352                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
353                                   "\nReceived EJECT REQUEST notification for device\n"));
354
355                 if (acpi_bus_get_device(handle, &device)) {
356                         printk(KERN_ERR PREFIX "Device doesn't exist\n");
357                         break;
358                 }
359                 mem_device = acpi_driver_data(device);
360                 if (!mem_device) {
361                         printk(KERN_ERR PREFIX "Driver Data is NULL\n");
362                         break;
363                 }
364
365                 /*
366                  * Currently disabling memory device from kernel mode
367                  * TBD: Can also be disabled from user mode scripts
368                  * TBD: Can also be disabled by Callback registration
369                  *      with generic sysfs driver
370                  */
371                 if (acpi_memory_disable_device(mem_device))
372                         printk(KERN_ERR PREFIX
373                                     "Disable memory device\n");
374                 /*
375                  * TBD: Invoke acpi_bus_remove to cleanup data structures
376                  */
377                 break;
378         default:
379                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
380                                   "Unsupported event [0x%x]\n", event));
381                 break;
382         }
383
384         return;
385 }
386
387 static int acpi_memory_device_add(struct acpi_device *device)
388 {
389         int result;
390         struct acpi_memory_device *mem_device = NULL;
391
392
393         if (!device)
394                 return -EINVAL;
395
396         mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
397         if (!mem_device)
398                 return -ENOMEM;
399         memset(mem_device, 0, sizeof(struct acpi_memory_device));
400
401         INIT_LIST_HEAD(&mem_device->res_list);
402         mem_device->device = device;
403         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
404         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
405         acpi_driver_data(device) = mem_device;
406
407         /* Get the range from the _CRS */
408         result = acpi_memory_get_device_resources(mem_device);
409         if (result) {
410                 kfree(mem_device);
411                 return result;
412         }
413
414         /* Set the device state */
415         mem_device->state = MEMORY_POWER_ON_STATE;
416
417         printk(KERN_INFO "%s \n", acpi_device_name(device));
418
419         return result;
420 }
421
422 static int acpi_memory_device_remove(struct acpi_device *device, int type)
423 {
424         struct acpi_memory_device *mem_device = NULL;
425
426
427         if (!device || !acpi_driver_data(device))
428                 return -EINVAL;
429
430         mem_device = (struct acpi_memory_device *)acpi_driver_data(device);
431         kfree(mem_device);
432
433         return 0;
434 }
435
436 static int acpi_memory_device_start (struct acpi_device *device)
437 {
438         struct acpi_memory_device *mem_device;
439         int result = 0;
440
441         mem_device = acpi_driver_data(device);
442
443         if (!acpi_memory_check_device(mem_device)) {
444                 /* call add_memory func */
445                 result = acpi_memory_enable_device(mem_device);
446                 if (result)
447                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
448                                 "Error in acpi_memory_enable_device\n"));
449         }
450         return result;
451 }
452
453 /*
454  * Helper function to check for memory device
455  */
456 static acpi_status is_memory_device(acpi_handle handle)
457 {
458         char *hardware_id;
459         acpi_status status;
460         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
461         struct acpi_device_info *info;
462
463
464         status = acpi_get_object_info(handle, &buffer);
465         if (ACPI_FAILURE(status))
466                 return status;
467
468         info = buffer.pointer;
469         if (!(info->valid & ACPI_VALID_HID)) {
470                 kfree(buffer.pointer);
471                 return AE_ERROR;
472         }
473
474         hardware_id = info->hardware_id.value;
475         if ((hardware_id == NULL) ||
476             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
477                 status = AE_ERROR;
478
479         kfree(buffer.pointer);
480         return status;
481 }
482
483 static acpi_status
484 acpi_memory_register_notify_handler(acpi_handle handle,
485                                     u32 level, void *ctxt, void **retv)
486 {
487         acpi_status status;
488
489
490         status = is_memory_device(handle);
491         if (ACPI_FAILURE(status))
492                 return AE_OK;   /* continue */
493
494         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
495                                              acpi_memory_device_notify, NULL);
496         /* continue */
497         return AE_OK;
498 }
499
500 static acpi_status
501 acpi_memory_deregister_notify_handler(acpi_handle handle,
502                                       u32 level, void *ctxt, void **retv)
503 {
504         acpi_status status;
505
506
507         status = is_memory_device(handle);
508         if (ACPI_FAILURE(status))
509                 return AE_OK;   /* continue */
510
511         status = acpi_remove_notify_handler(handle,
512                                             ACPI_SYSTEM_NOTIFY,
513                                             acpi_memory_device_notify);
514
515         return AE_OK;   /* continue */
516 }
517
518 static int __init acpi_memory_device_init(void)
519 {
520         int result;
521         acpi_status status;
522
523
524         result = acpi_bus_register_driver(&acpi_memory_device_driver);
525
526         if (result < 0)
527                 return -ENODEV;
528
529         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
530                                      ACPI_UINT32_MAX,
531                                      acpi_memory_register_notify_handler,
532                                      NULL, NULL);
533
534         if (ACPI_FAILURE(status)) {
535                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
536                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
537                 return -ENODEV;
538         }
539
540         return 0;
541 }
542
543 static void __exit acpi_memory_device_exit(void)
544 {
545         acpi_status status;
546
547
548         /*
549          * Adding this to un-install notification handlers for all the device
550          * handles.
551          */
552         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
553                                      ACPI_UINT32_MAX,
554                                      acpi_memory_deregister_notify_handler,
555                                      NULL, NULL);
556
557         if (ACPI_FAILURE(status))
558                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
559
560         acpi_bus_unregister_driver(&acpi_memory_device_driver);
561
562         return;
563 }
564
565 module_init(acpi_memory_device_init);
566 module_exit(acpi_memory_device_exit);