9a62224cc27816b039d116cc1732acad7080fdb2
[linux-2.6.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 <acpi/acpi_drivers.h>
34
35 #define ACPI_MEMORY_DEVICE_CLASS                "memory"
36 #define ACPI_MEMORY_DEVICE_HID                  "PNP0C80"
37 #define ACPI_MEMORY_DEVICE_NAME                 "Hotplug Mem Device"
38
39 #define _COMPONENT              ACPI_MEMORY_DEVICE_COMPONENT
40
41 #undef PREFIX
42 #define         PREFIX          "ACPI:memory_hp:"
43
44 ACPI_MODULE_NAME("acpi_memhotplug");
45 MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>");
46 MODULE_DESCRIPTION("Hotplug Mem Driver");
47 MODULE_LICENSE("GPL");
48
49 /* Memory Device States */
50 #define MEMORY_INVALID_STATE    0
51 #define MEMORY_POWER_ON_STATE   1
52 #define MEMORY_POWER_OFF_STATE  2
53
54 static int acpi_memory_device_add(struct acpi_device *device);
55 static int acpi_memory_device_remove(struct acpi_device *device, int type);
56 static int acpi_memory_device_start(struct acpi_device *device);
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                 .start = acpi_memory_device_start,
72                 },
73 };
74
75 struct acpi_memory_info {
76         struct list_head list;
77         u64 start_addr;         /* Memory Range start physical addr */
78         u64 length;             /* Memory Range length */
79         unsigned short caching; /* memory cache attribute */
80         unsigned short write_protect;   /* memory read/write attribute */
81         unsigned int enabled: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 int acpi_hotmem_initialized;
91
92 static acpi_status
93 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
94 {
95         struct acpi_memory_device *mem_device = context;
96         struct acpi_resource_address64 address64;
97         struct acpi_memory_info *info, *new;
98         acpi_status status;
99
100         status = acpi_resource_to_address64(resource, &address64);
101         if (ACPI_FAILURE(status) ||
102             (address64.resource_type != ACPI_MEMORY_RANGE))
103                 return AE_OK;
104
105         list_for_each_entry(info, &mem_device->res_list, list) {
106                 /* Can we combine the resource range information? */
107                 if ((info->caching == address64.info.mem.caching) &&
108                     (info->write_protect == address64.info.mem.write_protect) &&
109                     (info->start_addr + info->length == address64.minimum)) {
110                         info->length += address64.address_length;
111                         return AE_OK;
112                 }
113         }
114
115         new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
116         if (!new)
117                 return AE_ERROR;
118
119         INIT_LIST_HEAD(&new->list);
120         new->caching = address64.info.mem.caching;
121         new->write_protect = address64.info.mem.write_protect;
122         new->start_addr = address64.minimum;
123         new->length = address64.address_length;
124         list_add_tail(&new->list, &mem_device->res_list);
125
126         return AE_OK;
127 }
128
129 static int
130 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
131 {
132         acpi_status status;
133         struct acpi_memory_info *info, *n;
134
135
136         if (!list_empty(&mem_device->res_list))
137                 return 0;
138
139         status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
140                                      acpi_memory_get_resource, mem_device);
141         if (ACPI_FAILURE(status)) {
142                 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
143                         kfree(info);
144                 INIT_LIST_HEAD(&mem_device->res_list);
145                 return -EINVAL;
146         }
147
148         return 0;
149 }
150
151 static int
152 acpi_memory_get_device(acpi_handle handle,
153                        struct acpi_memory_device **mem_device)
154 {
155         acpi_status status;
156         acpi_handle phandle;
157         struct acpi_device *device = NULL;
158         struct acpi_device *pdevice = NULL;
159         int result;
160
161
162         if (!acpi_bus_get_device(handle, &device) && device)
163                 goto end;
164
165         status = acpi_get_parent(handle, &phandle);
166         if (ACPI_FAILURE(status)) {
167                 ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
168                 return -EINVAL;
169         }
170
171         /* Get the parent device */
172         result = acpi_bus_get_device(phandle, &pdevice);
173         if (result) {
174                 printk(KERN_WARNING PREFIX "Cannot get acpi bus device");
175                 return -EINVAL;
176         }
177
178         /*
179          * Now add the notified device.  This creates the acpi_device
180          * and invokes .add function
181          */
182         result = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
183         if (result) {
184                 printk(KERN_WARNING PREFIX "Cannot add acpi bus");
185                 return -EINVAL;
186         }
187
188       end:
189         *mem_device = acpi_driver_data(device);
190         if (!(*mem_device)) {
191                 printk(KERN_ERR "\n driver data not found");
192                 return -ENODEV;
193         }
194
195         return 0;
196 }
197
198 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
199 {
200         unsigned long long current_status;
201
202         /* Get device present/absent information from the _STA */
203         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
204                                                NULL, &current_status)))
205                 return -ENODEV;
206         /*
207          * Check for device status. Device should be
208          * present/enabled/functioning.
209          */
210         if (!((current_status & ACPI_STA_DEVICE_PRESENT)
211               && (current_status & ACPI_STA_DEVICE_ENABLED)
212               && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
213                 return -ENODEV;
214
215         return 0;
216 }
217
218 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
219 {
220         int result, num_enabled = 0;
221         struct acpi_memory_info *info;
222         int node;
223
224
225         /* Get the range from the _CRS */
226         result = acpi_memory_get_device_resources(mem_device);
227         if (result) {
228                 printk(KERN_ERR PREFIX "get_device_resources failed\n");
229                 mem_device->state = MEMORY_INVALID_STATE;
230                 return result;
231         }
232
233         node = acpi_get_node(mem_device->device->handle);
234         /*
235          * Tell the VM there is more memory here...
236          * Note: Assume that this function returns zero on success
237          * We don't have memory-hot-add rollback function,now.
238          * (i.e. memory-hot-remove function)
239          */
240         list_for_each_entry(info, &mem_device->res_list, list) {
241                 if (info->enabled) { /* just sanity check...*/
242                         num_enabled++;
243                         continue;
244                 }
245                 /*
246                  * If the memory block size is zero, please ignore it.
247                  * Don't try to do the following memory hotplug flowchart.
248                  */
249                 if (!info->length)
250                         continue;
251                 if (node < 0)
252                         node = memory_add_physaddr_to_nid(info->start_addr);
253
254                 result = add_memory(node, info->start_addr, info->length);
255                 if (result)
256                         continue;
257                 info->enabled = 1;
258                 num_enabled++;
259         }
260         if (!num_enabled) {
261                 printk(KERN_ERR PREFIX "add_memory failed\n");
262                 mem_device->state = MEMORY_INVALID_STATE;
263                 return -EINVAL;
264         }
265         /*
266          * Sometimes the memory device will contain several memory blocks.
267          * When one memory block is hot-added to the system memory, it will
268          * be regarded as a success.
269          * Otherwise if the last memory block can't be hot-added to the system
270          * memory, it will be failure and the memory device can't be bound with
271          * driver.
272          */
273         return 0;
274 }
275
276 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
277 {
278         acpi_status status;
279         struct acpi_object_list arg_list;
280         union acpi_object arg;
281         unsigned long long current_status;
282
283
284         /* Issue the _EJ0 command */
285         arg_list.count = 1;
286         arg_list.pointer = &arg;
287         arg.type = ACPI_TYPE_INTEGER;
288         arg.integer.value = 1;
289         status = acpi_evaluate_object(mem_device->device->handle,
290                                       "_EJ0", &arg_list, NULL);
291         /* Return on _EJ0 failure */
292         if (ACPI_FAILURE(status)) {
293                 ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
294                 return -ENODEV;
295         }
296
297         /* Evalute _STA to check if the device is disabled */
298         status = acpi_evaluate_integer(mem_device->device->handle, "_STA",
299                                        NULL, &current_status);
300         if (ACPI_FAILURE(status))
301                 return -ENODEV;
302
303         /* Check for device status.  Device should be disabled */
304         if (current_status & ACPI_STA_DEVICE_ENABLED)
305                 return -EINVAL;
306
307         return 0;
308 }
309
310 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
311 {
312         int result;
313         struct acpi_memory_info *info, *n;
314
315
316         /*
317          * Ask the VM to offline this memory range.
318          * Note: Assume that this function returns zero on success
319          */
320         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
321                 if (info->enabled) {
322                         result = remove_memory(info->start_addr, info->length);
323                         if (result)
324                                 return result;
325                 }
326                 kfree(info);
327         }
328
329         /* Power-off and eject the device */
330         result = acpi_memory_powerdown_device(mem_device);
331         if (result) {
332                 /* Set the status of the device to invalid */
333                 mem_device->state = MEMORY_INVALID_STATE;
334                 return result;
335         }
336
337         mem_device->state = MEMORY_POWER_OFF_STATE;
338         return result;
339 }
340
341 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
342 {
343         struct acpi_memory_device *mem_device;
344         struct acpi_device *device;
345
346
347         switch (event) {
348         case ACPI_NOTIFY_BUS_CHECK:
349                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
350                                   "\nReceived BUS CHECK notification for device\n"));
351                 /* Fall Through */
352         case ACPI_NOTIFY_DEVICE_CHECK:
353                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
354                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
355                                           "\nReceived DEVICE CHECK notification for device\n"));
356                 if (acpi_memory_get_device(handle, &mem_device)) {
357                         printk(KERN_ERR PREFIX "Cannot find driver data\n");
358                         return;
359                 }
360
361                 if (!acpi_memory_check_device(mem_device)) {
362                         if (acpi_memory_enable_device(mem_device))
363                                 printk(KERN_ERR PREFIX
364                                             "Cannot enable memory device\n");
365                 }
366                 break;
367         case ACPI_NOTIFY_EJECT_REQUEST:
368                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
369                                   "\nReceived EJECT REQUEST notification for device\n"));
370
371                 if (acpi_bus_get_device(handle, &device)) {
372                         printk(KERN_ERR PREFIX "Device doesn't exist\n");
373                         break;
374                 }
375                 mem_device = acpi_driver_data(device);
376                 if (!mem_device) {
377                         printk(KERN_ERR PREFIX "Driver Data is NULL\n");
378                         break;
379                 }
380
381                 /*
382                  * Currently disabling memory device from kernel mode
383                  * TBD: Can also be disabled from user mode scripts
384                  * TBD: Can also be disabled by Callback registration
385                  *      with generic sysfs driver
386                  */
387                 if (acpi_memory_disable_device(mem_device))
388                         printk(KERN_ERR PREFIX
389                                     "Disable memory device\n");
390                 /*
391                  * TBD: Invoke acpi_bus_remove to cleanup data structures
392                  */
393                 break;
394         default:
395                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
396                                   "Unsupported event [0x%x]\n", event));
397                 break;
398         }
399
400         return;
401 }
402
403 static int acpi_memory_device_add(struct acpi_device *device)
404 {
405         int result;
406         struct acpi_memory_device *mem_device = NULL;
407
408
409         if (!device)
410                 return -EINVAL;
411
412         mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
413         if (!mem_device)
414                 return -ENOMEM;
415
416         INIT_LIST_HEAD(&mem_device->res_list);
417         mem_device->device = device;
418         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
419         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
420         device->driver_data = mem_device;
421
422         /* Get the range from the _CRS */
423         result = acpi_memory_get_device_resources(mem_device);
424         if (result) {
425                 kfree(mem_device);
426                 return result;
427         }
428
429         /* Set the device state */
430         mem_device->state = MEMORY_POWER_ON_STATE;
431
432         printk(KERN_DEBUG "%s \n", acpi_device_name(device));
433
434         return result;
435 }
436
437 static int acpi_memory_device_remove(struct acpi_device *device, int type)
438 {
439         struct acpi_memory_device *mem_device = NULL;
440
441
442         if (!device || !acpi_driver_data(device))
443                 return -EINVAL;
444
445         mem_device = acpi_driver_data(device);
446         kfree(mem_device);
447
448         return 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         /*
457          * Early boot code has recognized memory area by EFI/E820.
458          * If DSDT shows these memory devices on boot, hotplug is not necessary
459          * for them. So, it just returns until completion of this driver's
460          * start up.
461          */
462         if (!acpi_hotmem_initialized)
463                 return 0;
464
465         mem_device = acpi_driver_data(device);
466
467         if (!acpi_memory_check_device(mem_device)) {
468                 /* call add_memory func */
469                 result = acpi_memory_enable_device(mem_device);
470                 if (result)
471                         printk(KERN_ERR PREFIX
472                                 "Error in acpi_memory_enable_device\n");
473         }
474         return result;
475 }
476
477 /*
478  * Helper function to check for memory device
479  */
480 static acpi_status is_memory_device(acpi_handle handle)
481 {
482         char *hardware_id;
483         acpi_status status;
484         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
485         struct acpi_device_info *info;
486
487
488         status = acpi_get_object_info(handle, &buffer);
489         if (ACPI_FAILURE(status))
490                 return status;
491
492         info = buffer.pointer;
493         if (!(info->valid & ACPI_VALID_HID)) {
494                 kfree(buffer.pointer);
495                 return AE_ERROR;
496         }
497
498         hardware_id = info->hardware_id.value;
499         if ((hardware_id == NULL) ||
500             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
501                 status = AE_ERROR;
502
503         kfree(buffer.pointer);
504         return status;
505 }
506
507 static acpi_status
508 acpi_memory_register_notify_handler(acpi_handle handle,
509                                     u32 level, void *ctxt, void **retv)
510 {
511         acpi_status status;
512
513
514         status = is_memory_device(handle);
515         if (ACPI_FAILURE(status))
516                 return AE_OK;   /* continue */
517
518         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
519                                              acpi_memory_device_notify, NULL);
520         /* continue */
521         return AE_OK;
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
531         status = is_memory_device(handle);
532         if (ACPI_FAILURE(status))
533                 return AE_OK;   /* continue */
534
535         status = acpi_remove_notify_handler(handle,
536                                             ACPI_SYSTEM_NOTIFY,
537                                             acpi_memory_device_notify);
538
539         return AE_OK;   /* continue */
540 }
541
542 static int __init acpi_memory_device_init(void)
543 {
544         int result;
545         acpi_status status;
546
547
548         result = acpi_bus_register_driver(&acpi_memory_device_driver);
549
550         if (result < 0)
551                 return -ENODEV;
552
553         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
554                                      ACPI_UINT32_MAX,
555                                      acpi_memory_register_notify_handler,
556                                      NULL, NULL);
557
558         if (ACPI_FAILURE(status)) {
559                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
560                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
561                 return -ENODEV;
562         }
563
564         acpi_hotmem_initialized = 1;
565         return 0;
566 }
567
568 static void __exit acpi_memory_device_exit(void)
569 {
570         acpi_status status;
571
572
573         /*
574          * Adding this to un-install notification handlers for all the device
575          * handles.
576          */
577         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
578                                      ACPI_UINT32_MAX,
579                                      acpi_memory_deregister_notify_handler,
580                                      NULL, NULL);
581
582         if (ACPI_FAILURE(status))
583                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
584
585         acpi_bus_unregister_driver(&acpi_memory_device_driver);
586
587         return;
588 }
589
590 module_init(acpi_memory_device_init);
591 module_exit(acpi_memory_device_exit);