Revert "ARM: tegra: tegratab: dummy change"
[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 <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 };
82
83 struct acpi_memory_device {
84         struct acpi_device * device;
85         unsigned int state;     /* State of the memory device */
86         struct list_head res_list;
87 };
88
89 static int acpi_hotmem_initialized;
90
91 static acpi_status
92 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
93 {
94         struct acpi_memory_device *mem_device = context;
95         struct acpi_resource_address64 address64;
96         struct acpi_memory_info *info, *new;
97         acpi_status status;
98
99         status = acpi_resource_to_address64(resource, &address64);
100         if (ACPI_FAILURE(status) ||
101             (address64.resource_type != ACPI_MEMORY_RANGE))
102                 return AE_OK;
103
104         list_for_each_entry(info, &mem_device->res_list, list) {
105                 /* Can we combine the resource range information? */
106                 if ((info->caching == address64.info.mem.caching) &&
107                     (info->write_protect == address64.info.mem.write_protect) &&
108                     (info->start_addr + info->length == address64.minimum)) {
109                         info->length += address64.address_length;
110                         return AE_OK;
111                 }
112         }
113
114         new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
115         if (!new)
116                 return AE_ERROR;
117
118         INIT_LIST_HEAD(&new->list);
119         new->caching = address64.info.mem.caching;
120         new->write_protect = address64.info.mem.write_protect;
121         new->start_addr = address64.minimum;
122         new->length = address64.address_length;
123         list_add_tail(&new->list, &mem_device->res_list);
124
125         return AE_OK;
126 }
127
128 static int
129 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
130 {
131         acpi_status status;
132         struct acpi_memory_info *info, *n;
133
134
135         if (!list_empty(&mem_device->res_list))
136                 return 0;
137
138         status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
139                                      acpi_memory_get_resource, mem_device);
140         if (ACPI_FAILURE(status)) {
141                 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
142                         kfree(info);
143                 INIT_LIST_HEAD(&mem_device->res_list);
144                 return -EINVAL;
145         }
146
147         return 0;
148 }
149
150 static int
151 acpi_memory_get_device(acpi_handle handle,
152                        struct acpi_memory_device **mem_device)
153 {
154         acpi_status status;
155         acpi_handle phandle;
156         struct acpi_device *device = NULL;
157         struct acpi_device *pdevice = NULL;
158         int result;
159
160
161         if (!acpi_bus_get_device(handle, &device) && device)
162                 goto end;
163
164         status = acpi_get_parent(handle, &phandle);
165         if (ACPI_FAILURE(status)) {
166                 ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
167                 return -EINVAL;
168         }
169
170         /* Get the parent device */
171         result = acpi_bus_get_device(phandle, &pdevice);
172         if (result) {
173                 printk(KERN_WARNING PREFIX "Cannot get acpi bus device");
174                 return -EINVAL;
175         }
176
177         /*
178          * Now add the notified device.  This creates the acpi_device
179          * and invokes .add function
180          */
181         result = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
182         if (result) {
183                 printk(KERN_WARNING PREFIX "Cannot add acpi bus");
184                 return -EINVAL;
185         }
186
187       end:
188         *mem_device = acpi_driver_data(device);
189         if (!(*mem_device)) {
190                 printk(KERN_ERR "\n driver data not found");
191                 return -ENODEV;
192         }
193
194         return 0;
195 }
196
197 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
198 {
199         unsigned long long current_status;
200
201         /* Get device present/absent information from the _STA */
202         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
203                                                NULL, &current_status)))
204                 return -ENODEV;
205         /*
206          * Check for device status. Device should be
207          * present/enabled/functioning.
208          */
209         if (!((current_status & ACPI_STA_DEVICE_PRESENT)
210               && (current_status & ACPI_STA_DEVICE_ENABLED)
211               && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
212                 return -ENODEV;
213
214         return 0;
215 }
216
217 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
218 {
219         int result, num_enabled = 0;
220         struct acpi_memory_info *info;
221         int node;
222
223
224         /* Get the range from the _CRS */
225         result = acpi_memory_get_device_resources(mem_device);
226         if (result) {
227                 printk(KERN_ERR PREFIX "get_device_resources failed\n");
228                 mem_device->state = MEMORY_INVALID_STATE;
229                 return result;
230         }
231
232         node = acpi_get_node(mem_device->device->handle);
233         /*
234          * Tell the VM there is more memory here...
235          * Note: Assume that this function returns zero on success
236          * We don't have memory-hot-add rollback function,now.
237          * (i.e. memory-hot-remove function)
238          */
239         list_for_each_entry(info, &mem_device->res_list, list) {
240                 if (info->enabled) { /* just sanity check...*/
241                         num_enabled++;
242                         continue;
243                 }
244                 /*
245                  * If the memory block size is zero, please ignore it.
246                  * Don't try to do the following memory hotplug flowchart.
247                  */
248                 if (!info->length)
249                         continue;
250                 if (node < 0)
251                         node = memory_add_physaddr_to_nid(info->start_addr);
252
253                 result = add_memory(node, info->start_addr, info->length);
254                 if (result)
255                         continue;
256                 info->enabled = 1;
257                 num_enabled++;
258         }
259         if (!num_enabled) {
260                 printk(KERN_ERR PREFIX "add_memory failed\n");
261                 mem_device->state = MEMORY_INVALID_STATE;
262                 return -EINVAL;
263         }
264         /*
265          * Sometimes the memory device will contain several memory blocks.
266          * When one memory block is hot-added to the system memory, it will
267          * be regarded as a success.
268          * Otherwise if the last memory block can't be hot-added to the system
269          * memory, it will be failure and the memory device can't be bound with
270          * driver.
271          */
272         return 0;
273 }
274
275 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
276 {
277         acpi_status status;
278         struct acpi_object_list arg_list;
279         union acpi_object arg;
280         unsigned long long current_status;
281
282
283         /* Issue the _EJ0 command */
284         arg_list.count = 1;
285         arg_list.pointer = &arg;
286         arg.type = ACPI_TYPE_INTEGER;
287         arg.integer.value = 1;
288         status = acpi_evaluate_object(mem_device->device->handle,
289                                       "_EJ0", &arg_list, NULL);
290         /* Return on _EJ0 failure */
291         if (ACPI_FAILURE(status)) {
292                 ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
293                 return -ENODEV;
294         }
295
296         /* Evalute _STA to check if the device is disabled */
297         status = acpi_evaluate_integer(mem_device->device->handle, "_STA",
298                                        NULL, &current_status);
299         if (ACPI_FAILURE(status))
300                 return -ENODEV;
301
302         /* Check for device status.  Device should be disabled */
303         if (current_status & ACPI_STA_DEVICE_ENABLED)
304                 return -EINVAL;
305
306         return 0;
307 }
308
309 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
310 {
311         int result;
312         struct acpi_memory_info *info, *n;
313
314
315         /*
316          * Ask the VM to offline this memory range.
317          * Note: Assume that this function returns zero on success
318          */
319         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
320                 if (info->enabled) {
321                         result = remove_memory(info->start_addr, info->length);
322                         if (result)
323                                 return result;
324                 }
325                 kfree(info);
326         }
327
328         /* Power-off and eject the device */
329         result = acpi_memory_powerdown_device(mem_device);
330         if (result) {
331                 /* Set the status of the device to invalid */
332                 mem_device->state = MEMORY_INVALID_STATE;
333                 return result;
334         }
335
336         mem_device->state = MEMORY_POWER_OFF_STATE;
337         return result;
338 }
339
340 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
341 {
342         struct acpi_memory_device *mem_device;
343         struct acpi_device *device;
344
345
346         switch (event) {
347         case ACPI_NOTIFY_BUS_CHECK:
348                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
349                                   "\nReceived BUS CHECK notification for device\n"));
350                 /* Fall Through */
351         case ACPI_NOTIFY_DEVICE_CHECK:
352                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
353                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
354                                           "\nReceived DEVICE CHECK notification for device\n"));
355                 if (acpi_memory_get_device(handle, &mem_device)) {
356                         printk(KERN_ERR PREFIX "Cannot find driver data\n");
357                         return;
358                 }
359
360                 if (!acpi_memory_check_device(mem_device)) {
361                         if (acpi_memory_enable_device(mem_device))
362                                 printk(KERN_ERR PREFIX
363                                             "Cannot enable memory device\n");
364                 }
365                 break;
366         case ACPI_NOTIFY_EJECT_REQUEST:
367                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
368                                   "\nReceived EJECT REQUEST notification for device\n"));
369
370                 if (acpi_bus_get_device(handle, &device)) {
371                         printk(KERN_ERR PREFIX "Device doesn't exist\n");
372                         break;
373                 }
374                 mem_device = acpi_driver_data(device);
375                 if (!mem_device) {
376                         printk(KERN_ERR PREFIX "Driver Data is NULL\n");
377                         break;
378                 }
379
380                 /*
381                  * Currently disabling memory device from kernel mode
382                  * TBD: Can also be disabled from user mode scripts
383                  * TBD: Can also be disabled by Callback registration
384                  *      with generic sysfs driver
385                  */
386                 if (acpi_memory_disable_device(mem_device))
387                         printk(KERN_ERR PREFIX
388                                     "Disable memory device\n");
389                 /*
390                  * TBD: Invoke acpi_bus_remove to cleanup data structures
391                  */
392                 break;
393         default:
394                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
395                                   "Unsupported event [0x%x]\n", event));
396                 break;
397         }
398
399         return;
400 }
401
402 static int acpi_memory_device_add(struct acpi_device *device)
403 {
404         int result;
405         struct acpi_memory_device *mem_device = NULL;
406
407
408         if (!device)
409                 return -EINVAL;
410
411         mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
412         if (!mem_device)
413                 return -ENOMEM;
414
415         INIT_LIST_HEAD(&mem_device->res_list);
416         mem_device->device = device;
417         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
418         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
419         device->driver_data = mem_device;
420
421         /* Get the range from the _CRS */
422         result = acpi_memory_get_device_resources(mem_device);
423         if (result) {
424                 device->driver_data = NULL;
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         /*
435          * Early boot code has recognized memory area by EFI/E820.
436          * If DSDT shows these memory devices on boot, hotplug is not necessary
437          * for them. So, it just returns until completion of this driver's
438          * start up.
439          */
440         if (!acpi_hotmem_initialized)
441                 return 0;
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                         printk(KERN_ERR PREFIX
448                                 "Error in acpi_memory_enable_device\n");
449         }
450         return result;
451 }
452
453 static int acpi_memory_device_remove(struct acpi_device *device, int type)
454 {
455         struct acpi_memory_device *mem_device = NULL;
456
457
458         if (!device || !acpi_driver_data(device))
459                 return -EINVAL;
460
461         mem_device = acpi_driver_data(device);
462         kfree(mem_device);
463
464         return 0;
465 }
466
467 /*
468  * Helper function to check for memory device
469  */
470 static acpi_status is_memory_device(acpi_handle handle)
471 {
472         char *hardware_id;
473         acpi_status status;
474         struct acpi_device_info *info;
475
476         status = acpi_get_object_info(handle, &info);
477         if (ACPI_FAILURE(status))
478                 return status;
479
480         if (!(info->valid & ACPI_VALID_HID)) {
481                 kfree(info);
482                 return AE_ERROR;
483         }
484
485         hardware_id = info->hardware_id.string;
486         if ((hardware_id == NULL) ||
487             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
488                 status = AE_ERROR;
489
490         kfree(info);
491         return status;
492 }
493
494 static acpi_status
495 acpi_memory_register_notify_handler(acpi_handle handle,
496                                     u32 level, void *ctxt, void **retv)
497 {
498         acpi_status status;
499
500
501         status = is_memory_device(handle);
502         if (ACPI_FAILURE(status))
503                 return AE_OK;   /* continue */
504
505         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
506                                              acpi_memory_device_notify, NULL);
507         /* continue */
508         return AE_OK;
509 }
510
511 static acpi_status
512 acpi_memory_deregister_notify_handler(acpi_handle handle,
513                                       u32 level, void *ctxt, void **retv)
514 {
515         acpi_status status;
516
517
518         status = is_memory_device(handle);
519         if (ACPI_FAILURE(status))
520                 return AE_OK;   /* continue */
521
522         status = acpi_remove_notify_handler(handle,
523                                             ACPI_SYSTEM_NOTIFY,
524                                             acpi_memory_device_notify);
525
526         return AE_OK;   /* continue */
527 }
528
529 static int __init acpi_memory_device_init(void)
530 {
531         int result;
532         acpi_status status;
533
534
535         result = acpi_bus_register_driver(&acpi_memory_device_driver);
536
537         if (result < 0)
538                 return -ENODEV;
539
540         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
541                                      ACPI_UINT32_MAX,
542                                      acpi_memory_register_notify_handler, NULL,
543                                      NULL, NULL);
544
545         if (ACPI_FAILURE(status)) {
546                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
547                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
548                 return -ENODEV;
549         }
550
551         acpi_hotmem_initialized = 1;
552         return 0;
553 }
554
555 static void __exit acpi_memory_device_exit(void)
556 {
557         acpi_status status;
558
559
560         /*
561          * Adding this to un-install notification handlers for all the device
562          * handles.
563          */
564         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
565                                      ACPI_UINT32_MAX,
566                                      acpi_memory_deregister_notify_handler, NULL,
567                                      NULL, NULL);
568
569         if (ACPI_FAILURE(status))
570                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
571
572         acpi_bus_unregister_driver(&acpi_memory_device_driver);
573
574         return;
575 }
576
577 module_init(acpi_memory_device_init);
578 module_exit(acpi_memory_device_exit);