Merge branch 'bugzilla-11715' into test
[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_NAME                 "Hotplug Mem Device"
39
40 #define _COMPONENT              ACPI_MEMORY_DEVICE_COMPONENT
41
42 ACPI_MODULE_NAME("acpi_memhotplug");
43 MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>");
44 MODULE_DESCRIPTION("Hotplug Mem Driver");
45 MODULE_LICENSE("GPL");
46
47 /* Memory Device States */
48 #define MEMORY_INVALID_STATE    0
49 #define MEMORY_POWER_ON_STATE   1
50 #define MEMORY_POWER_OFF_STATE  2
51
52 static int acpi_memory_device_add(struct acpi_device *device);
53 static int acpi_memory_device_remove(struct acpi_device *device, int type);
54 static int acpi_memory_device_start(struct acpi_device *device);
55
56 static const struct acpi_device_id memory_device_ids[] = {
57         {ACPI_MEMORY_DEVICE_HID, 0},
58         {"", 0},
59 };
60 MODULE_DEVICE_TABLE(acpi, memory_device_ids);
61
62 static struct acpi_driver acpi_memory_device_driver = {
63         .name = "acpi_memhotplug",
64         .class = ACPI_MEMORY_DEVICE_CLASS,
65         .ids = memory_device_ids,
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 int acpi_hotmem_initialized;
89
90 static acpi_status
91 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
92 {
93         struct acpi_memory_device *mem_device = context;
94         struct acpi_resource_address64 address64;
95         struct acpi_memory_info *info, *new;
96         acpi_status status;
97
98         status = acpi_resource_to_address64(resource, &address64);
99         if (ACPI_FAILURE(status) ||
100             (address64.resource_type != ACPI_MEMORY_RANGE))
101                 return AE_OK;
102
103         list_for_each_entry(info, &mem_device->res_list, list) {
104                 /* Can we combine the resource range information? */
105                 if ((info->caching == address64.info.mem.caching) &&
106                     (info->write_protect == address64.info.mem.write_protect) &&
107                     (info->start_addr + info->length == address64.minimum)) {
108                         info->length += address64.address_length;
109                         return AE_OK;
110                 }
111         }
112
113         new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
114         if (!new)
115                 return AE_ERROR;
116
117         INIT_LIST_HEAD(&new->list);
118         new->caching = address64.info.mem.caching;
119         new->write_protect = address64.info.mem.write_protect;
120         new->start_addr = address64.minimum;
121         new->length = address64.address_length;
122         list_add_tail(&new->list, &mem_device->res_list);
123
124         return AE_OK;
125 }
126
127 static int
128 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
129 {
130         acpi_status status;
131         struct acpi_memory_info *info, *n;
132
133
134         if (!list_empty(&mem_device->res_list))
135                 return 0;
136
137         status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
138                                      acpi_memory_get_resource, mem_device);
139         if (ACPI_FAILURE(status)) {
140                 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
141                         kfree(info);
142                 INIT_LIST_HEAD(&mem_device->res_list);
143                 return -EINVAL;
144         }
145
146         return 0;
147 }
148
149 static int
150 acpi_memory_get_device(acpi_handle handle,
151                        struct acpi_memory_device **mem_device)
152 {
153         acpi_status status;
154         acpi_handle phandle;
155         struct acpi_device *device = NULL;
156         struct acpi_device *pdevice = NULL;
157
158
159         if (!acpi_bus_get_device(handle, &device) && device)
160                 goto end;
161
162         status = acpi_get_parent(handle, &phandle);
163         if (ACPI_FAILURE(status)) {
164                 ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
165                 return -EINVAL;
166         }
167
168         /* Get the parent device */
169         status = acpi_bus_get_device(phandle, &pdevice);
170         if (ACPI_FAILURE(status)) {
171                 ACPI_EXCEPTION((AE_INFO, status, "Cannot get acpi bus device"));
172                 return -EINVAL;
173         }
174
175         /*
176          * Now add the notified device.  This creates the acpi_device
177          * and invokes .add function
178          */
179         status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
180         if (ACPI_FAILURE(status)) {
181                 ACPI_EXCEPTION((AE_INFO, status, "Cannot add acpi bus"));
182                 return -EINVAL;
183         }
184
185       end:
186         *mem_device = acpi_driver_data(device);
187         if (!(*mem_device)) {
188                 printk(KERN_ERR "\n driver data not found");
189                 return -ENODEV;
190         }
191
192         return 0;
193 }
194
195 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
196 {
197         unsigned long long current_status;
198
199         /* Get device present/absent information from the _STA */
200         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
201                                                NULL, &current_status)))
202                 return -ENODEV;
203         /*
204          * Check for device status. Device should be
205          * present/enabled/functioning.
206          */
207         if (!((current_status & ACPI_STA_DEVICE_PRESENT)
208               && (current_status & ACPI_STA_DEVICE_ENABLED)
209               && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
210                 return -ENODEV;
211
212         return 0;
213 }
214
215 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
216 {
217         int result, num_enabled = 0;
218         struct acpi_memory_info *info;
219         int node;
220
221
222         /* Get the range from the _CRS */
223         result = acpi_memory_get_device_resources(mem_device);
224         if (result) {
225                 printk(KERN_ERR PREFIX "get_device_resources failed\n");
226                 mem_device->state = MEMORY_INVALID_STATE;
227                 return result;
228         }
229
230         node = acpi_get_node(mem_device->device->handle);
231         /*
232          * Tell the VM there is more memory here...
233          * Note: Assume that this function returns zero on success
234          * We don't have memory-hot-add rollback function,now.
235          * (i.e. memory-hot-remove function)
236          */
237         list_for_each_entry(info, &mem_device->res_list, list) {
238                 if (info->enabled) { /* just sanity check...*/
239                         num_enabled++;
240                         continue;
241                 }
242
243                 if (node < 0)
244                         node = memory_add_physaddr_to_nid(info->start_addr);
245
246                 result = add_memory(node, info->start_addr, info->length);
247                 if (result)
248                         continue;
249                 info->enabled = 1;
250                 num_enabled++;
251         }
252         if (!num_enabled) {
253                 printk(KERN_ERR PREFIX "add_memory failed\n");
254                 mem_device->state = MEMORY_INVALID_STATE;
255                 return -EINVAL;
256         }
257
258         return result;
259 }
260
261 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
262 {
263         acpi_status status;
264         struct acpi_object_list arg_list;
265         union acpi_object arg;
266         unsigned long long current_status;
267
268
269         /* Issue the _EJ0 command */
270         arg_list.count = 1;
271         arg_list.pointer = &arg;
272         arg.type = ACPI_TYPE_INTEGER;
273         arg.integer.value = 1;
274         status = acpi_evaluate_object(mem_device->device->handle,
275                                       "_EJ0", &arg_list, NULL);
276         /* Return on _EJ0 failure */
277         if (ACPI_FAILURE(status)) {
278                 ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
279                 return -ENODEV;
280         }
281
282         /* Evalute _STA to check if the device is disabled */
283         status = acpi_evaluate_integer(mem_device->device->handle, "_STA",
284                                        NULL, &current_status);
285         if (ACPI_FAILURE(status))
286                 return -ENODEV;
287
288         /* Check for device status.  Device should be disabled */
289         if (current_status & ACPI_STA_DEVICE_ENABLED)
290                 return -EINVAL;
291
292         return 0;
293 }
294
295 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
296 {
297         int result;
298         struct acpi_memory_info *info, *n;
299
300
301         /*
302          * Ask the VM to offline this memory range.
303          * Note: Assume that this function returns zero on success
304          */
305         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
306                 if (info->enabled) {
307                         result = remove_memory(info->start_addr, info->length);
308                         if (result)
309                                 return result;
310                 }
311                 kfree(info);
312         }
313
314         /* Power-off and eject the device */
315         result = acpi_memory_powerdown_device(mem_device);
316         if (result) {
317                 /* Set the status of the device to invalid */
318                 mem_device->state = MEMORY_INVALID_STATE;
319                 return result;
320         }
321
322         mem_device->state = MEMORY_POWER_OFF_STATE;
323         return result;
324 }
325
326 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
327 {
328         struct acpi_memory_device *mem_device;
329         struct acpi_device *device;
330
331
332         switch (event) {
333         case ACPI_NOTIFY_BUS_CHECK:
334                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
335                                   "\nReceived BUS CHECK notification for device\n"));
336                 /* Fall Through */
337         case ACPI_NOTIFY_DEVICE_CHECK:
338                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
339                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
340                                           "\nReceived DEVICE CHECK notification for device\n"));
341                 if (acpi_memory_get_device(handle, &mem_device)) {
342                         printk(KERN_ERR PREFIX "Cannot find driver data\n");
343                         return;
344                 }
345
346                 if (!acpi_memory_check_device(mem_device)) {
347                         if (acpi_memory_enable_device(mem_device))
348                                 printk(KERN_ERR PREFIX
349                                             "Cannot enable memory device\n");
350                 }
351                 break;
352         case ACPI_NOTIFY_EJECT_REQUEST:
353                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
354                                   "\nReceived EJECT REQUEST notification for device\n"));
355
356                 if (acpi_bus_get_device(handle, &device)) {
357                         printk(KERN_ERR PREFIX "Device doesn't exist\n");
358                         break;
359                 }
360                 mem_device = acpi_driver_data(device);
361                 if (!mem_device) {
362                         printk(KERN_ERR PREFIX "Driver Data is NULL\n");
363                         break;
364                 }
365
366                 /*
367                  * Currently disabling memory device from kernel mode
368                  * TBD: Can also be disabled from user mode scripts
369                  * TBD: Can also be disabled by Callback registration
370                  *      with generic sysfs driver
371                  */
372                 if (acpi_memory_disable_device(mem_device))
373                         printk(KERN_ERR PREFIX
374                                     "Disable memory device\n");
375                 /*
376                  * TBD: Invoke acpi_bus_remove to cleanup data structures
377                  */
378                 break;
379         default:
380                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
381                                   "Unsupported event [0x%x]\n", event));
382                 break;
383         }
384
385         return;
386 }
387
388 static int acpi_memory_device_add(struct acpi_device *device)
389 {
390         int result;
391         struct acpi_memory_device *mem_device = NULL;
392
393
394         if (!device)
395                 return -EINVAL;
396
397         mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
398         if (!mem_device)
399                 return -ENOMEM;
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         device->driver_data = 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_DEBUG "%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 = 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         /*
442          * Early boot code has recognized memory area by EFI/E820.
443          * If DSDT shows these memory devices on boot, hotplug is not necessary
444          * for them. So, it just returns until completion of this driver's
445          * start up.
446          */
447         if (!acpi_hotmem_initialized)
448                 return 0;
449
450         mem_device = acpi_driver_data(device);
451
452         if (!acpi_memory_check_device(mem_device)) {
453                 /* call add_memory func */
454                 result = acpi_memory_enable_device(mem_device);
455                 if (result)
456                         printk(KERN_ERR PREFIX
457                                 "Error in acpi_memory_enable_device\n");
458         }
459         return result;
460 }
461
462 /*
463  * Helper function to check for memory device
464  */
465 static acpi_status is_memory_device(acpi_handle handle)
466 {
467         char *hardware_id;
468         acpi_status status;
469         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
470         struct acpi_device_info *info;
471
472
473         status = acpi_get_object_info(handle, &buffer);
474         if (ACPI_FAILURE(status))
475                 return status;
476
477         info = buffer.pointer;
478         if (!(info->valid & ACPI_VALID_HID)) {
479                 kfree(buffer.pointer);
480                 return AE_ERROR;
481         }
482
483         hardware_id = info->hardware_id.value;
484         if ((hardware_id == NULL) ||
485             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
486                 status = AE_ERROR;
487
488         kfree(buffer.pointer);
489         return status;
490 }
491
492 static acpi_status
493 acpi_memory_register_notify_handler(acpi_handle handle,
494                                     u32 level, void *ctxt, void **retv)
495 {
496         acpi_status status;
497
498
499         status = is_memory_device(handle);
500         if (ACPI_FAILURE(status))
501                 return AE_OK;   /* continue */
502
503         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
504                                              acpi_memory_device_notify, NULL);
505         /* continue */
506         return AE_OK;
507 }
508
509 static acpi_status
510 acpi_memory_deregister_notify_handler(acpi_handle handle,
511                                       u32 level, void *ctxt, void **retv)
512 {
513         acpi_status status;
514
515
516         status = is_memory_device(handle);
517         if (ACPI_FAILURE(status))
518                 return AE_OK;   /* continue */
519
520         status = acpi_remove_notify_handler(handle,
521                                             ACPI_SYSTEM_NOTIFY,
522                                             acpi_memory_device_notify);
523
524         return AE_OK;   /* continue */
525 }
526
527 static int __init acpi_memory_device_init(void)
528 {
529         int result;
530         acpi_status status;
531
532
533         result = acpi_bus_register_driver(&acpi_memory_device_driver);
534
535         if (result < 0)
536                 return -ENODEV;
537
538         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
539                                      ACPI_UINT32_MAX,
540                                      acpi_memory_register_notify_handler,
541                                      NULL, NULL);
542
543         if (ACPI_FAILURE(status)) {
544                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
545                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
546                 return -ENODEV;
547         }
548
549         acpi_hotmem_initialized = 1;
550         return 0;
551 }
552
553 static void __exit acpi_memory_device_exit(void)
554 {
555         acpi_status status;
556
557
558         /*
559          * Adding this to un-install notification handlers for all the device
560          * handles.
561          */
562         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
563                                      ACPI_UINT32_MAX,
564                                      acpi_memory_deregister_notify_handler,
565                                      NULL, NULL);
566
567         if (ACPI_FAILURE(status))
568                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
569
570         acpi_bus_unregister_driver(&acpi_memory_device_driver);
571
572         return;
573 }
574
575 module_init(acpi_memory_device_init);
576 module_exit(acpi_memory_device_exit);