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acpi_memhotplug.c: bind the memory device when the driver is being loaded
[karo-tx-linux.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 firmware 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 <linux/slab.h>
34 #include <acpi/acpi_drivers.h>
35
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 #undef PREFIX
43 #define         PREFIX          "ACPI:memory_hp:"
44
45 ACPI_MODULE_NAME("acpi_memhotplug");
46 MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>");
47 MODULE_DESCRIPTION("Hotplug Mem Driver");
48 MODULE_LICENSE("GPL");
49
50 /* Memory Device States */
51 #define MEMORY_INVALID_STATE    0
52 #define MEMORY_POWER_ON_STATE   1
53 #define MEMORY_POWER_OFF_STATE  2
54
55 static int acpi_memory_device_add(struct acpi_device *device);
56 static int acpi_memory_device_remove(struct acpi_device *device, int type);
57
58 static const struct acpi_device_id memory_device_ids[] = {
59         {ACPI_MEMORY_DEVICE_HID, 0},
60         {"", 0},
61 };
62 MODULE_DEVICE_TABLE(acpi, memory_device_ids);
63
64 static struct acpi_driver acpi_memory_device_driver = {
65         .name = "acpi_memhotplug",
66         .class = ACPI_MEMORY_DEVICE_CLASS,
67         .ids = memory_device_ids,
68         .ops = {
69                 .add = acpi_memory_device_add,
70                 .remove = acpi_memory_device_remove,
71                 },
72 };
73
74 struct acpi_memory_info {
75         struct list_head list;
76         u64 start_addr;         /* Memory Range start physical addr */
77         u64 length;             /* Memory Range length */
78         unsigned short caching; /* memory cache attribute */
79         unsigned short write_protect;   /* memory read/write attribute */
80         unsigned int enabled:1;
81         unsigned int failed:1;
82 };
83
84 struct acpi_memory_device {
85         struct acpi_device * device;
86         unsigned int state;     /* State of the memory device */
87         struct list_head res_list;
88 };
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 void
128 acpi_memory_free_device_resources(struct acpi_memory_device *mem_device)
129 {
130         struct acpi_memory_info *info, *n;
131
132         list_for_each_entry_safe(info, n, &mem_device->res_list, list)
133                 kfree(info);
134         INIT_LIST_HEAD(&mem_device->res_list);
135 }
136
137 static int
138 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
139 {
140         acpi_status status;
141
142         if (!list_empty(&mem_device->res_list))
143                 return 0;
144
145         status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
146                                      acpi_memory_get_resource, mem_device);
147         if (ACPI_FAILURE(status)) {
148                 acpi_memory_free_device_resources(mem_device);
149                 return -EINVAL;
150         }
151
152         return 0;
153 }
154
155 static int
156 acpi_memory_get_device(acpi_handle handle,
157                        struct acpi_memory_device **mem_device)
158 {
159         acpi_status status;
160         acpi_handle phandle;
161         struct acpi_device *device = NULL;
162         struct acpi_device *pdevice = NULL;
163         int result;
164
165
166         if (!acpi_bus_get_device(handle, &device) && device)
167                 goto end;
168
169         status = acpi_get_parent(handle, &phandle);
170         if (ACPI_FAILURE(status)) {
171                 ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
172                 return -EINVAL;
173         }
174
175         /* Get the parent device */
176         result = acpi_bus_get_device(phandle, &pdevice);
177         if (result) {
178                 printk(KERN_WARNING PREFIX "Cannot get acpi bus device");
179                 return -EINVAL;
180         }
181
182         /*
183          * Now add the notified device.  This creates the acpi_device
184          * and invokes .add function
185          */
186         result = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
187         if (result) {
188                 printk(KERN_WARNING PREFIX "Cannot add acpi bus");
189                 return -EINVAL;
190         }
191
192       end:
193         *mem_device = acpi_driver_data(device);
194         if (!(*mem_device)) {
195                 printk(KERN_ERR "\n driver data not found");
196                 return -ENODEV;
197         }
198
199         return 0;
200 }
201
202 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
203 {
204         unsigned long long current_status;
205
206         /* Get device present/absent information from the _STA */
207         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
208                                                NULL, &current_status)))
209                 return -ENODEV;
210         /*
211          * Check for device status. Device should be
212          * present/enabled/functioning.
213          */
214         if (!((current_status & ACPI_STA_DEVICE_PRESENT)
215               && (current_status & ACPI_STA_DEVICE_ENABLED)
216               && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
217                 return -ENODEV;
218
219         return 0;
220 }
221
222 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
223 {
224         int result, num_enabled = 0;
225         struct acpi_memory_info *info;
226         int node;
227
228
229         /* Get the range from the _CRS */
230         result = acpi_memory_get_device_resources(mem_device);
231         if (result) {
232                 printk(KERN_ERR PREFIX "get_device_resources failed\n");
233                 mem_device->state = MEMORY_INVALID_STATE;
234                 return result;
235         }
236
237         node = acpi_get_node(mem_device->device->handle);
238         /*
239          * Tell the VM there is more memory here...
240          * Note: Assume that this function returns zero on success
241          * We don't have memory-hot-add rollback function,now.
242          * (i.e. memory-hot-remove function)
243          */
244         list_for_each_entry(info, &mem_device->res_list, list) {
245                 if (info->enabled) { /* just sanity check...*/
246                         num_enabled++;
247                         continue;
248                 }
249                 /*
250                  * If the memory block size is zero, please ignore it.
251                  * Don't try to do the following memory hotplug flowchart.
252                  */
253                 if (!info->length)
254                         continue;
255                 if (node < 0)
256                         node = memory_add_physaddr_to_nid(info->start_addr);
257
258                 result = add_memory(node, info->start_addr, info->length);
259
260                 /*
261                  * If the memory block has been used by the kernel, add_memory()
262                  * returns -EEXIST. If add_memory() returns the other error, it
263                  * means that this memory block is not used by the kernel.
264                  */
265                 if (result && result != -EEXIST) {
266                         info->failed = 1;
267                         continue;
268                 }
269
270                 if (!result)
271                         info->enabled = 1;
272                 /*
273                  * Add num_enable even if add_memory() returns -EEXIST, so the
274                  * device is bound to this driver.
275                  */
276                 num_enabled++;
277         }
278         if (!num_enabled) {
279                 printk(KERN_ERR PREFIX "add_memory failed\n");
280                 mem_device->state = MEMORY_INVALID_STATE;
281                 return -EINVAL;
282         }
283         /*
284          * Sometimes the memory device will contain several memory blocks.
285          * When one memory block is hot-added to the system memory, it will
286          * be regarded as a success.
287          * Otherwise if the last memory block can't be hot-added to the system
288          * memory, it will be failure and the memory device can't be bound with
289          * driver.
290          */
291         return 0;
292 }
293
294 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
295 {
296         acpi_status status;
297         struct acpi_object_list arg_list;
298         union acpi_object arg;
299         unsigned long long current_status;
300
301
302         /* Issue the _EJ0 command */
303         arg_list.count = 1;
304         arg_list.pointer = &arg;
305         arg.type = ACPI_TYPE_INTEGER;
306         arg.integer.value = 1;
307         status = acpi_evaluate_object(mem_device->device->handle,
308                                       "_EJ0", &arg_list, NULL);
309         /* Return on _EJ0 failure */
310         if (ACPI_FAILURE(status)) {
311                 ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
312                 return -ENODEV;
313         }
314
315         /* Evalute _STA to check if the device is disabled */
316         status = acpi_evaluate_integer(mem_device->device->handle, "_STA",
317                                        NULL, &current_status);
318         if (ACPI_FAILURE(status))
319                 return -ENODEV;
320
321         /* Check for device status.  Device should be disabled */
322         if (current_status & ACPI_STA_DEVICE_ENABLED)
323                 return -EINVAL;
324
325         return 0;
326 }
327
328 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
329 {
330         int result;
331         struct acpi_memory_info *info, *n;
332
333
334         /*
335          * Ask the VM to offline this memory range.
336          * Note: Assume that this function returns zero on success
337          */
338         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
339                 if (info->failed)
340                         /* The kernel does not use this memory block */
341                         continue;
342
343                 if (!info->enabled)
344                         /*
345                          * The kernel uses this memory block, but it may be not
346                          * managed by us.
347                          */
348                         return -EBUSY;
349
350                 result = remove_memory(info->start_addr, info->length);
351                 if (result)
352                         return result;
353                 list_del(&info->list);
354                 kfree(info);
355         }
356
357         /* Power-off and eject the device */
358         result = acpi_memory_powerdown_device(mem_device);
359         if (result) {
360                 /* Set the status of the device to invalid */
361                 mem_device->state = MEMORY_INVALID_STATE;
362                 return result;
363         }
364
365         mem_device->state = MEMORY_POWER_OFF_STATE;
366         return result;
367 }
368
369 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
370 {
371         struct acpi_memory_device *mem_device;
372         struct acpi_device *device;
373         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
374
375         switch (event) {
376         case ACPI_NOTIFY_BUS_CHECK:
377                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
378                                   "\nReceived BUS CHECK notification for device\n"));
379                 /* Fall Through */
380         case ACPI_NOTIFY_DEVICE_CHECK:
381                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
382                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
383                                           "\nReceived DEVICE CHECK notification for device\n"));
384                 if (acpi_memory_get_device(handle, &mem_device)) {
385                         printk(KERN_ERR PREFIX "Cannot find driver data\n");
386                         break;
387                 }
388
389                 if (acpi_memory_check_device(mem_device))
390                         break;
391
392                 if (acpi_memory_enable_device(mem_device)) {
393                         printk(KERN_ERR PREFIX "Cannot enable memory device\n");
394                         break;
395                 }
396
397                 ost_code = ACPI_OST_SC_SUCCESS;
398                 break;
399
400         case ACPI_NOTIFY_EJECT_REQUEST:
401                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
402                                   "\nReceived EJECT REQUEST notification for device\n"));
403
404                 if (acpi_bus_get_device(handle, &device)) {
405                         printk(KERN_ERR PREFIX "Device doesn't exist\n");
406                         break;
407                 }
408                 mem_device = acpi_driver_data(device);
409                 if (!mem_device) {
410                         printk(KERN_ERR PREFIX "Driver Data is NULL\n");
411                         break;
412                 }
413
414                 /*
415                  * Currently disabling memory device from kernel mode
416                  * TBD: Can also be disabled from user mode scripts
417                  * TBD: Can also be disabled by Callback registration
418                  *      with generic sysfs driver
419                  */
420                 if (acpi_memory_disable_device(mem_device)) {
421                         printk(KERN_ERR PREFIX "Disable memory device\n");
422                         /*
423                          * If _EJ0 was called but failed, _OST is not
424                          * necessary.
425                          */
426                         if (mem_device->state == MEMORY_INVALID_STATE)
427                                 return;
428
429                         break;
430                 }
431
432                 /*
433                  * TBD: Invoke acpi_bus_remove to cleanup data structures
434                  */
435
436                 /* _EJ0 succeeded; _OST is not necessary */
437                 return;
438
439         default:
440                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
441                                   "Unsupported event [0x%x]\n", event));
442
443                 /* non-hotplug event; possibly handled by other handler */
444                 return;
445         }
446
447         /* Inform firmware that the hotplug operation has completed */
448         (void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
449         return;
450 }
451
452 static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
453 {
454         if (!mem_device)
455                 return;
456
457         acpi_memory_free_device_resources(mem_device);
458         kfree(mem_device);
459 }
460
461 static int acpi_memory_device_add(struct acpi_device *device)
462 {
463         int result;
464         struct acpi_memory_device *mem_device = NULL;
465
466
467         if (!device)
468                 return -EINVAL;
469
470         mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
471         if (!mem_device)
472                 return -ENOMEM;
473
474         INIT_LIST_HEAD(&mem_device->res_list);
475         mem_device->device = device;
476         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
477         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
478         device->driver_data = mem_device;
479
480         /* Get the range from the _CRS */
481         result = acpi_memory_get_device_resources(mem_device);
482         if (result) {
483                 kfree(mem_device);
484                 return result;
485         }
486
487         /* Set the device state */
488         mem_device->state = MEMORY_POWER_ON_STATE;
489
490         printk(KERN_DEBUG "%s \n", acpi_device_name(device));
491
492         if (!acpi_memory_check_device(mem_device)) {
493                 /* call add_memory func */
494                 result = acpi_memory_enable_device(mem_device);
495                 if (result) {
496                         printk(KERN_ERR PREFIX
497                                 "Error in acpi_memory_enable_device\n");
498                         acpi_memory_device_free(mem_device);
499                 }
500         }
501         return result;
502 }
503
504 static int acpi_memory_device_remove(struct acpi_device *device, int type)
505 {
506         if (!device || !acpi_driver_data(device))
507                 return -EINVAL;
508
509         acpi_memory_device_free(acpi_driver_data(device));
510
511         return 0;
512 }
513
514 /*
515  * Helper function to check for memory device
516  */
517 static acpi_status is_memory_device(acpi_handle handle)
518 {
519         char *hardware_id;
520         acpi_status status;
521         struct acpi_device_info *info;
522
523         status = acpi_get_object_info(handle, &info);
524         if (ACPI_FAILURE(status))
525                 return status;
526
527         if (!(info->valid & ACPI_VALID_HID)) {
528                 kfree(info);
529                 return AE_ERROR;
530         }
531
532         hardware_id = info->hardware_id.string;
533         if ((hardware_id == NULL) ||
534             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
535                 status = AE_ERROR;
536
537         kfree(info);
538         return status;
539 }
540
541 static acpi_status
542 acpi_memory_register_notify_handler(acpi_handle handle,
543                                     u32 level, void *ctxt, void **retv)
544 {
545         acpi_status status;
546
547
548         status = is_memory_device(handle);
549         if (ACPI_FAILURE(status))
550                 return AE_OK;   /* continue */
551
552         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
553                                              acpi_memory_device_notify, NULL);
554         /* continue */
555         return AE_OK;
556 }
557
558 static acpi_status
559 acpi_memory_deregister_notify_handler(acpi_handle handle,
560                                       u32 level, void *ctxt, void **retv)
561 {
562         acpi_status status;
563
564
565         status = is_memory_device(handle);
566         if (ACPI_FAILURE(status))
567                 return AE_OK;   /* continue */
568
569         status = acpi_remove_notify_handler(handle,
570                                             ACPI_SYSTEM_NOTIFY,
571                                             acpi_memory_device_notify);
572
573         return AE_OK;   /* continue */
574 }
575
576 static int __init acpi_memory_device_init(void)
577 {
578         int result;
579         acpi_status status;
580
581
582         result = acpi_bus_register_driver(&acpi_memory_device_driver);
583
584         if (result < 0)
585                 return -ENODEV;
586
587         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
588                                      ACPI_UINT32_MAX,
589                                      acpi_memory_register_notify_handler, NULL,
590                                      NULL, NULL);
591
592         if (ACPI_FAILURE(status)) {
593                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
594                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
595                 return -ENODEV;
596         }
597
598         return 0;
599 }
600
601 static void __exit acpi_memory_device_exit(void)
602 {
603         acpi_status status;
604
605
606         /*
607          * Adding this to un-install notification handlers for all the device
608          * handles.
609          */
610         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
611                                      ACPI_UINT32_MAX,
612                                      acpi_memory_deregister_notify_handler, NULL,
613                                      NULL, NULL);
614
615         if (ACPI_FAILURE(status))
616                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
617
618         acpi_bus_unregister_driver(&acpi_memory_device_driver);
619
620         return;
621 }
622
623 module_init(acpi_memory_device_init);
624 module_exit(acpi_memory_device_exit);