Merge branch 'upstream-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/linvil...
[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                 result = add_memory(node, info->start_addr, info->length);
242                 if (result)
243                         continue;
244                 info->enabled = 1;
245                 num_enabled++;
246         }
247         if (!num_enabled) {
248                 printk(KERN_ERR PREFIX "add_memory failed\n");
249                 mem_device->state = MEMORY_INVALID_STATE;
250                 return -EINVAL;
251         }
252
253         return result;
254 }
255
256 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
257 {
258         acpi_status status;
259         struct acpi_object_list arg_list;
260         union acpi_object arg;
261         unsigned long current_status;
262
263
264         /* Issue the _EJ0 command */
265         arg_list.count = 1;
266         arg_list.pointer = &arg;
267         arg.type = ACPI_TYPE_INTEGER;
268         arg.integer.value = 1;
269         status = acpi_evaluate_object(mem_device->device->handle,
270                                       "_EJ0", &arg_list, NULL);
271         /* Return on _EJ0 failure */
272         if (ACPI_FAILURE(status)) {
273                 ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
274                 return -ENODEV;
275         }
276
277         /* Evalute _STA to check if the device is disabled */
278         status = acpi_evaluate_integer(mem_device->device->handle, "_STA",
279                                        NULL, &current_status);
280         if (ACPI_FAILURE(status))
281                 return -ENODEV;
282
283         /* Check for device status.  Device should be disabled */
284         if (current_status & ACPI_MEMORY_STA_ENABLED)
285                 return -EINVAL;
286
287         return 0;
288 }
289
290 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
291 {
292         int result;
293         struct acpi_memory_info *info, *n;
294
295
296         /*
297          * Ask the VM to offline this memory range.
298          * Note: Assume that this function returns zero on success
299          */
300         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
301                 if (info->enabled) {
302                         result = remove_memory(info->start_addr, info->length);
303                         if (result)
304                                 return result;
305                 }
306                 kfree(info);
307         }
308
309         /* Power-off and eject the device */
310         result = acpi_memory_powerdown_device(mem_device);
311         if (result) {
312                 /* Set the status of the device to invalid */
313                 mem_device->state = MEMORY_INVALID_STATE;
314                 return result;
315         }
316
317         mem_device->state = MEMORY_POWER_OFF_STATE;
318         return result;
319 }
320
321 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
322 {
323         struct acpi_memory_device *mem_device;
324         struct acpi_device *device;
325
326
327         switch (event) {
328         case ACPI_NOTIFY_BUS_CHECK:
329                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
330                                   "\nReceived BUS CHECK notification for device\n"));
331                 /* Fall Through */
332         case ACPI_NOTIFY_DEVICE_CHECK:
333                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
334                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
335                                           "\nReceived DEVICE CHECK notification for device\n"));
336                 if (acpi_memory_get_device(handle, &mem_device)) {
337                         printk(KERN_ERR PREFIX "Cannot find driver data\n");
338                         return;
339                 }
340
341                 if (!acpi_memory_check_device(mem_device)) {
342                         if (acpi_memory_enable_device(mem_device))
343                                 printk(KERN_ERR PREFIX
344                                             "Cannot enable memory device\n");
345                 }
346                 break;
347         case ACPI_NOTIFY_EJECT_REQUEST:
348                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
349                                   "\nReceived EJECT REQUEST notification for device\n"));
350
351                 if (acpi_bus_get_device(handle, &device)) {
352                         printk(KERN_ERR PREFIX "Device doesn't exist\n");
353                         break;
354                 }
355                 mem_device = acpi_driver_data(device);
356                 if (!mem_device) {
357                         printk(KERN_ERR PREFIX "Driver Data is NULL\n");
358                         break;
359                 }
360
361                 /*
362                  * Currently disabling memory device from kernel mode
363                  * TBD: Can also be disabled from user mode scripts
364                  * TBD: Can also be disabled by Callback registration
365                  *      with generic sysfs driver
366                  */
367                 if (acpi_memory_disable_device(mem_device))
368                         printk(KERN_ERR PREFIX
369                                     "Disable memory device\n");
370                 /*
371                  * TBD: Invoke acpi_bus_remove to cleanup data structures
372                  */
373                 break;
374         default:
375                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
376                                   "Unsupported event [0x%x]\n", event));
377                 break;
378         }
379
380         return;
381 }
382
383 static int acpi_memory_device_add(struct acpi_device *device)
384 {
385         int result;
386         struct acpi_memory_device *mem_device = NULL;
387
388
389         if (!device)
390                 return -EINVAL;
391
392         mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
393         if (!mem_device)
394                 return -ENOMEM;
395         memset(mem_device, 0, sizeof(struct acpi_memory_device));
396
397         INIT_LIST_HEAD(&mem_device->res_list);
398         mem_device->device = device;
399         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
400         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
401         acpi_driver_data(device) = mem_device;
402
403         /* Get the range from the _CRS */
404         result = acpi_memory_get_device_resources(mem_device);
405         if (result) {
406                 kfree(mem_device);
407                 return result;
408         }
409
410         /* Set the device state */
411         mem_device->state = MEMORY_POWER_ON_STATE;
412
413         printk(KERN_INFO "%s \n", acpi_device_name(device));
414
415         return result;
416 }
417
418 static int acpi_memory_device_remove(struct acpi_device *device, int type)
419 {
420         struct acpi_memory_device *mem_device = NULL;
421
422
423         if (!device || !acpi_driver_data(device))
424                 return -EINVAL;
425
426         mem_device = (struct acpi_memory_device *)acpi_driver_data(device);
427         kfree(mem_device);
428
429         return 0;
430 }
431
432 static int acpi_memory_device_start (struct acpi_device *device)
433 {
434         struct acpi_memory_device *mem_device;
435         int result = 0;
436
437         mem_device = acpi_driver_data(device);
438
439         if (!acpi_memory_check_device(mem_device)) {
440                 /* call add_memory func */
441                 result = acpi_memory_enable_device(mem_device);
442                 if (result)
443                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
444                                 "Error in acpi_memory_enable_device\n"));
445         }
446         return result;
447 }
448
449 /*
450  * Helper function to check for memory device
451  */
452 static acpi_status is_memory_device(acpi_handle handle)
453 {
454         char *hardware_id;
455         acpi_status status;
456         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
457         struct acpi_device_info *info;
458
459
460         status = acpi_get_object_info(handle, &buffer);
461         if (ACPI_FAILURE(status))
462                 return status;
463
464         info = buffer.pointer;
465         if (!(info->valid & ACPI_VALID_HID)) {
466                 kfree(buffer.pointer);
467                 return AE_ERROR;
468         }
469
470         hardware_id = info->hardware_id.value;
471         if ((hardware_id == NULL) ||
472             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
473                 status = AE_ERROR;
474
475         kfree(buffer.pointer);
476         return status;
477 }
478
479 static acpi_status
480 acpi_memory_register_notify_handler(acpi_handle handle,
481                                     u32 level, void *ctxt, void **retv)
482 {
483         acpi_status status;
484
485
486         status = is_memory_device(handle);
487         if (ACPI_FAILURE(status)){
488                 ACPI_EXCEPTION((AE_INFO, status, "handle is no memory device"));
489                 return AE_OK;   /* continue */
490         }
491
492         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
493                                              acpi_memory_device_notify, NULL);
494         /* continue */
495         return AE_OK;
496 }
497
498 static acpi_status
499 acpi_memory_deregister_notify_handler(acpi_handle handle,
500                                       u32 level, void *ctxt, void **retv)
501 {
502         acpi_status status;
503
504
505         status = is_memory_device(handle);
506         if (ACPI_FAILURE(status)){
507                 ACPI_EXCEPTION((AE_INFO, status, "handle is no memory device"));
508                 return AE_OK;   /* continue */
509         }
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);