USB: gadgetfs behaves better on userspace init bug
[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 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 current_status;
198
199
200         /* Get device present/absent information from the _STA */
201         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
202                                                NULL, &current_status)))
203                 return -ENODEV;
204         /*
205          * Check for device status. Device should be
206          * present/enabled/functioning.
207          */
208         if (!((current_status & ACPI_MEMORY_STA_PRESENT)
209               && (current_status & ACPI_MEMORY_STA_ENABLED)
210               && (current_status & ACPI_MEMORY_STA_FUNCTIONAL)))
211                 return -ENODEV;
212
213         return 0;
214 }
215
216 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
217 {
218         int result, num_enabled = 0;
219         struct acpi_memory_info *info;
220         int node;
221
222
223         /* Get the range from the _CRS */
224         result = acpi_memory_get_device_resources(mem_device);
225         if (result) {
226                 printk(KERN_ERR PREFIX "get_device_resources failed\n");
227                 mem_device->state = MEMORY_INVALID_STATE;
228                 return result;
229         }
230
231         node = acpi_get_node(mem_device->device->handle);
232         /*
233          * Tell the VM there is more memory here...
234          * Note: Assume that this function returns zero on success
235          * We don't have memory-hot-add rollback function,now.
236          * (i.e. memory-hot-remove function)
237          */
238         list_for_each_entry(info, &mem_device->res_list, list) {
239                 if (info->enabled) { /* just sanity check...*/
240                         num_enabled++;
241                         continue;
242                 }
243
244                 if (node < 0)
245                         node = memory_add_physaddr_to_nid(info->start_addr);
246
247                 result = add_memory(node, info->start_addr, info->length);
248                 if (result)
249                         continue;
250                 info->enabled = 1;
251                 num_enabled++;
252         }
253         if (!num_enabled) {
254                 printk(KERN_ERR PREFIX "add_memory failed\n");
255                 mem_device->state = MEMORY_INVALID_STATE;
256                 return -EINVAL;
257         }
258
259         return result;
260 }
261
262 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
263 {
264         acpi_status status;
265         struct acpi_object_list arg_list;
266         union acpi_object arg;
267         unsigned long current_status;
268
269
270         /* Issue the _EJ0 command */
271         arg_list.count = 1;
272         arg_list.pointer = &arg;
273         arg.type = ACPI_TYPE_INTEGER;
274         arg.integer.value = 1;
275         status = acpi_evaluate_object(mem_device->device->handle,
276                                       "_EJ0", &arg_list, NULL);
277         /* Return on _EJ0 failure */
278         if (ACPI_FAILURE(status)) {
279                 ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
280                 return -ENODEV;
281         }
282
283         /* Evalute _STA to check if the device is disabled */
284         status = acpi_evaluate_integer(mem_device->device->handle, "_STA",
285                                        NULL, &current_status);
286         if (ACPI_FAILURE(status))
287                 return -ENODEV;
288
289         /* Check for device status.  Device should be disabled */
290         if (current_status & ACPI_MEMORY_STA_ENABLED)
291                 return -EINVAL;
292
293         return 0;
294 }
295
296 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
297 {
298         int result;
299         struct acpi_memory_info *info, *n;
300
301
302         /*
303          * Ask the VM to offline this memory range.
304          * Note: Assume that this function returns zero on success
305          */
306         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
307                 if (info->enabled) {
308                         result = remove_memory(info->start_addr, info->length);
309                         if (result)
310                                 return result;
311                 }
312                 kfree(info);
313         }
314
315         /* Power-off and eject the device */
316         result = acpi_memory_powerdown_device(mem_device);
317         if (result) {
318                 /* Set the status of the device to invalid */
319                 mem_device->state = MEMORY_INVALID_STATE;
320                 return result;
321         }
322
323         mem_device->state = MEMORY_POWER_OFF_STATE;
324         return result;
325 }
326
327 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
328 {
329         struct acpi_memory_device *mem_device;
330         struct acpi_device *device;
331
332
333         switch (event) {
334         case ACPI_NOTIFY_BUS_CHECK:
335                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
336                                   "\nReceived BUS CHECK notification for device\n"));
337                 /* Fall Through */
338         case ACPI_NOTIFY_DEVICE_CHECK:
339                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
340                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
341                                           "\nReceived DEVICE CHECK notification for device\n"));
342                 if (acpi_memory_get_device(handle, &mem_device)) {
343                         printk(KERN_ERR PREFIX "Cannot find driver data\n");
344                         return;
345                 }
346
347                 if (!acpi_memory_check_device(mem_device)) {
348                         if (acpi_memory_enable_device(mem_device))
349                                 printk(KERN_ERR PREFIX
350                                             "Cannot enable memory device\n");
351                 }
352                 break;
353         case ACPI_NOTIFY_EJECT_REQUEST:
354                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
355                                   "\nReceived EJECT REQUEST notification for device\n"));
356
357                 if (acpi_bus_get_device(handle, &device)) {
358                         printk(KERN_ERR PREFIX "Device doesn't exist\n");
359                         break;
360                 }
361                 mem_device = acpi_driver_data(device);
362                 if (!mem_device) {
363                         printk(KERN_ERR PREFIX "Driver Data is NULL\n");
364                         break;
365                 }
366
367                 /*
368                  * Currently disabling memory device from kernel mode
369                  * TBD: Can also be disabled from user mode scripts
370                  * TBD: Can also be disabled by Callback registration
371                  *      with generic sysfs driver
372                  */
373                 if (acpi_memory_disable_device(mem_device))
374                         printk(KERN_ERR PREFIX
375                                     "Disable memory device\n");
376                 /*
377                  * TBD: Invoke acpi_bus_remove to cleanup data structures
378                  */
379                 break;
380         default:
381                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
382                                   "Unsupported event [0x%x]\n", event));
383                 break;
384         }
385
386         return;
387 }
388
389 static int acpi_memory_device_add(struct acpi_device *device)
390 {
391         int result;
392         struct acpi_memory_device *mem_device = NULL;
393
394
395         if (!device)
396                 return -EINVAL;
397
398         mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
399         if (!mem_device)
400                 return -ENOMEM;
401
402         INIT_LIST_HEAD(&mem_device->res_list);
403         mem_device->device = device;
404         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
405         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
406         acpi_driver_data(device) = mem_device;
407
408         /* Get the range from the _CRS */
409         result = acpi_memory_get_device_resources(mem_device);
410         if (result) {
411                 kfree(mem_device);
412                 return result;
413         }
414
415         /* Set the device state */
416         mem_device->state = MEMORY_POWER_ON_STATE;
417
418         printk(KERN_DEBUG "%s \n", acpi_device_name(device));
419
420         return result;
421 }
422
423 static int acpi_memory_device_remove(struct acpi_device *device, int type)
424 {
425         struct acpi_memory_device *mem_device = NULL;
426
427
428         if (!device || !acpi_driver_data(device))
429                 return -EINVAL;
430
431         mem_device = acpi_driver_data(device);
432         kfree(mem_device);
433
434         return 0;
435 }
436
437 static int acpi_memory_device_start (struct acpi_device *device)
438 {
439         struct acpi_memory_device *mem_device;
440         int result = 0;
441
442         /*
443          * Early boot code has recognized memory area by EFI/E820.
444          * If DSDT shows these memory devices on boot, hotplug is not necessary
445          * for them. So, it just returns until completion of this driver's
446          * start up.
447          */
448         if (!acpi_hotmem_initialized)
449                 return 0;
450
451         mem_device = acpi_driver_data(device);
452
453         if (!acpi_memory_check_device(mem_device)) {
454                 /* call add_memory func */
455                 result = acpi_memory_enable_device(mem_device);
456                 if (result)
457                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
458                                 "Error in acpi_memory_enable_device\n"));
459         }
460         return result;
461 }
462
463 /*
464  * Helper function to check for memory device
465  */
466 static acpi_status is_memory_device(acpi_handle handle)
467 {
468         char *hardware_id;
469         acpi_status status;
470         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
471         struct acpi_device_info *info;
472
473
474         status = acpi_get_object_info(handle, &buffer);
475         if (ACPI_FAILURE(status))
476                 return status;
477
478         info = buffer.pointer;
479         if (!(info->valid & ACPI_VALID_HID)) {
480                 kfree(buffer.pointer);
481                 return AE_ERROR;
482         }
483
484         hardware_id = info->hardware_id.value;
485         if ((hardware_id == NULL) ||
486             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
487                 status = AE_ERROR;
488
489         kfree(buffer.pointer);
490         return status;
491 }
492
493 static acpi_status
494 acpi_memory_register_notify_handler(acpi_handle handle,
495                                     u32 level, void *ctxt, void **retv)
496 {
497         acpi_status status;
498
499
500         status = is_memory_device(handle);
501         if (ACPI_FAILURE(status))
502                 return AE_OK;   /* continue */
503
504         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
505                                              acpi_memory_device_notify, NULL);
506         /* continue */
507         return AE_OK;
508 }
509
510 static acpi_status
511 acpi_memory_deregister_notify_handler(acpi_handle handle,
512                                       u32 level, void *ctxt, void **retv)
513 {
514         acpi_status status;
515
516
517         status = is_memory_device(handle);
518         if (ACPI_FAILURE(status))
519                 return AE_OK;   /* continue */
520
521         status = acpi_remove_notify_handler(handle,
522                                             ACPI_SYSTEM_NOTIFY,
523                                             acpi_memory_device_notify);
524
525         return AE_OK;   /* continue */
526 }
527
528 static int __init acpi_memory_device_init(void)
529 {
530         int result;
531         acpi_status status;
532
533
534         result = acpi_bus_register_driver(&acpi_memory_device_driver);
535
536         if (result < 0)
537                 return -ENODEV;
538
539         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
540                                      ACPI_UINT32_MAX,
541                                      acpi_memory_register_notify_handler,
542                                      NULL, NULL);
543
544         if (ACPI_FAILURE(status)) {
545                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
546                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
547                 return -ENODEV;
548         }
549
550         acpi_hotmem_initialized = 1;
551         return 0;
552 }
553
554 static void __exit acpi_memory_device_exit(void)
555 {
556         acpi_status status;
557
558
559         /*
560          * Adding this to un-install notification handlers for all the device
561          * handles.
562          */
563         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
564                                      ACPI_UINT32_MAX,
565                                      acpi_memory_deregister_notify_handler,
566                                      NULL, NULL);
567
568         if (ACPI_FAILURE(status))
569                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
570
571         acpi_bus_unregister_driver(&acpi_memory_device_driver);
572
573         return;
574 }
575
576 module_init(acpi_memory_device_init);
577 module_exit(acpi_memory_device_exit);