xen: add static initialization of steal_clock op to xen_time_ops
[sfrench/cifs-2.6.git] / drivers / acpi / scan.c
1 /*
2  * scan.c - support for transforming the ACPI namespace into individual objects
3  */
4
5 #include <linux/module.h>
6 #include <linux/init.h>
7 #include <linux/slab.h>
8 #include <linux/kernel.h>
9 #include <linux/acpi.h>
10 #include <linux/signal.h>
11 #include <linux/kthread.h>
12 #include <linux/dmi.h>
13 #include <linux/nls.h>
14 #include <linux/dma-mapping.h>
15
16 #include <asm/pgtable.h>
17
18 #include "internal.h"
19
20 #define _COMPONENT              ACPI_BUS_COMPONENT
21 ACPI_MODULE_NAME("scan");
22 extern struct acpi_device *acpi_root;
23
24 #define ACPI_BUS_CLASS                  "system_bus"
25 #define ACPI_BUS_HID                    "LNXSYBUS"
26 #define ACPI_BUS_DEVICE_NAME            "System Bus"
27
28 #define ACPI_IS_ROOT_DEVICE(device)    (!(device)->parent)
29
30 #define INVALID_ACPI_HANDLE     ((acpi_handle)empty_zero_page)
31
32 /*
33  * If set, devices will be hot-removed even if they cannot be put offline
34  * gracefully (from the kernel's standpoint).
35  */
36 bool acpi_force_hot_remove;
37
38 static const char *dummy_hid = "device";
39
40 static LIST_HEAD(acpi_dep_list);
41 static DEFINE_MUTEX(acpi_dep_list_lock);
42 LIST_HEAD(acpi_bus_id_list);
43 static DEFINE_MUTEX(acpi_scan_lock);
44 static LIST_HEAD(acpi_scan_handlers_list);
45 DEFINE_MUTEX(acpi_device_lock);
46 LIST_HEAD(acpi_wakeup_device_list);
47 static DEFINE_MUTEX(acpi_hp_context_lock);
48
49 /*
50  * The UART device described by the SPCR table is the only object which needs
51  * special-casing. Everything else is covered by ACPI namespace paths in STAO
52  * table.
53  */
54 static u64 spcr_uart_addr;
55
56 struct acpi_dep_data {
57         struct list_head node;
58         acpi_handle master;
59         acpi_handle slave;
60 };
61
62 void acpi_scan_lock_acquire(void)
63 {
64         mutex_lock(&acpi_scan_lock);
65 }
66 EXPORT_SYMBOL_GPL(acpi_scan_lock_acquire);
67
68 void acpi_scan_lock_release(void)
69 {
70         mutex_unlock(&acpi_scan_lock);
71 }
72 EXPORT_SYMBOL_GPL(acpi_scan_lock_release);
73
74 void acpi_lock_hp_context(void)
75 {
76         mutex_lock(&acpi_hp_context_lock);
77 }
78
79 void acpi_unlock_hp_context(void)
80 {
81         mutex_unlock(&acpi_hp_context_lock);
82 }
83
84 void acpi_initialize_hp_context(struct acpi_device *adev,
85                                 struct acpi_hotplug_context *hp,
86                                 int (*notify)(struct acpi_device *, u32),
87                                 void (*uevent)(struct acpi_device *, u32))
88 {
89         acpi_lock_hp_context();
90         hp->notify = notify;
91         hp->uevent = uevent;
92         acpi_set_hp_context(adev, hp);
93         acpi_unlock_hp_context();
94 }
95 EXPORT_SYMBOL_GPL(acpi_initialize_hp_context);
96
97 int acpi_scan_add_handler(struct acpi_scan_handler *handler)
98 {
99         if (!handler)
100                 return -EINVAL;
101
102         list_add_tail(&handler->list_node, &acpi_scan_handlers_list);
103         return 0;
104 }
105
106 int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
107                                        const char *hotplug_profile_name)
108 {
109         int error;
110
111         error = acpi_scan_add_handler(handler);
112         if (error)
113                 return error;
114
115         acpi_sysfs_add_hotplug_profile(&handler->hotplug, hotplug_profile_name);
116         return 0;
117 }
118
119 bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent)
120 {
121         struct acpi_device_physical_node *pn;
122         bool offline = true;
123
124         /*
125          * acpi_container_offline() calls this for all of the container's
126          * children under the container's physical_node_lock lock.
127          */
128         mutex_lock_nested(&adev->physical_node_lock, SINGLE_DEPTH_NESTING);
129
130         list_for_each_entry(pn, &adev->physical_node_list, node)
131                 if (device_supports_offline(pn->dev) && !pn->dev->offline) {
132                         if (uevent)
133                                 kobject_uevent(&pn->dev->kobj, KOBJ_CHANGE);
134
135                         offline = false;
136                         break;
137                 }
138
139         mutex_unlock(&adev->physical_node_lock);
140         return offline;
141 }
142
143 static acpi_status acpi_bus_offline(acpi_handle handle, u32 lvl, void *data,
144                                     void **ret_p)
145 {
146         struct acpi_device *device = NULL;
147         struct acpi_device_physical_node *pn;
148         bool second_pass = (bool)data;
149         acpi_status status = AE_OK;
150
151         if (acpi_bus_get_device(handle, &device))
152                 return AE_OK;
153
154         if (device->handler && !device->handler->hotplug.enabled) {
155                 *ret_p = &device->dev;
156                 return AE_SUPPORT;
157         }
158
159         mutex_lock(&device->physical_node_lock);
160
161         list_for_each_entry(pn, &device->physical_node_list, node) {
162                 int ret;
163
164                 if (second_pass) {
165                         /* Skip devices offlined by the first pass. */
166                         if (pn->put_online)
167                                 continue;
168                 } else {
169                         pn->put_online = false;
170                 }
171                 ret = device_offline(pn->dev);
172                 if (acpi_force_hot_remove)
173                         continue;
174
175                 if (ret >= 0) {
176                         pn->put_online = !ret;
177                 } else {
178                         *ret_p = pn->dev;
179                         if (second_pass) {
180                                 status = AE_ERROR;
181                                 break;
182                         }
183                 }
184         }
185
186         mutex_unlock(&device->physical_node_lock);
187
188         return status;
189 }
190
191 static acpi_status acpi_bus_online(acpi_handle handle, u32 lvl, void *data,
192                                    void **ret_p)
193 {
194         struct acpi_device *device = NULL;
195         struct acpi_device_physical_node *pn;
196
197         if (acpi_bus_get_device(handle, &device))
198                 return AE_OK;
199
200         mutex_lock(&device->physical_node_lock);
201
202         list_for_each_entry(pn, &device->physical_node_list, node)
203                 if (pn->put_online) {
204                         device_online(pn->dev);
205                         pn->put_online = false;
206                 }
207
208         mutex_unlock(&device->physical_node_lock);
209
210         return AE_OK;
211 }
212
213 static int acpi_scan_try_to_offline(struct acpi_device *device)
214 {
215         acpi_handle handle = device->handle;
216         struct device *errdev = NULL;
217         acpi_status status;
218
219         /*
220          * Carry out two passes here and ignore errors in the first pass,
221          * because if the devices in question are memory blocks and
222          * CONFIG_MEMCG is set, one of the blocks may hold data structures
223          * that the other blocks depend on, but it is not known in advance which
224          * block holds them.
225          *
226          * If the first pass is successful, the second one isn't needed, though.
227          */
228         status = acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
229                                      NULL, acpi_bus_offline, (void *)false,
230                                      (void **)&errdev);
231         if (status == AE_SUPPORT) {
232                 dev_warn(errdev, "Offline disabled.\n");
233                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
234                                     acpi_bus_online, NULL, NULL, NULL);
235                 return -EPERM;
236         }
237         acpi_bus_offline(handle, 0, (void *)false, (void **)&errdev);
238         if (errdev) {
239                 errdev = NULL;
240                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
241                                     NULL, acpi_bus_offline, (void *)true,
242                                     (void **)&errdev);
243                 if (!errdev || acpi_force_hot_remove)
244                         acpi_bus_offline(handle, 0, (void *)true,
245                                          (void **)&errdev);
246
247                 if (errdev && !acpi_force_hot_remove) {
248                         dev_warn(errdev, "Offline failed.\n");
249                         acpi_bus_online(handle, 0, NULL, NULL);
250                         acpi_walk_namespace(ACPI_TYPE_ANY, handle,
251                                             ACPI_UINT32_MAX, acpi_bus_online,
252                                             NULL, NULL, NULL);
253                         return -EBUSY;
254                 }
255         }
256         return 0;
257 }
258
259 static int acpi_scan_hot_remove(struct acpi_device *device)
260 {
261         acpi_handle handle = device->handle;
262         unsigned long long sta;
263         acpi_status status;
264
265         if (device->handler && device->handler->hotplug.demand_offline
266             && !acpi_force_hot_remove) {
267                 if (!acpi_scan_is_offline(device, true))
268                         return -EBUSY;
269         } else {
270                 int error = acpi_scan_try_to_offline(device);
271                 if (error)
272                         return error;
273         }
274
275         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
276                 "Hot-removing device %s...\n", dev_name(&device->dev)));
277
278         acpi_bus_trim(device);
279
280         acpi_evaluate_lck(handle, 0);
281         /*
282          * TBD: _EJD support.
283          */
284         status = acpi_evaluate_ej0(handle);
285         if (status == AE_NOT_FOUND)
286                 return -ENODEV;
287         else if (ACPI_FAILURE(status))
288                 return -EIO;
289
290         /*
291          * Verify if eject was indeed successful.  If not, log an error
292          * message.  No need to call _OST since _EJ0 call was made OK.
293          */
294         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
295         if (ACPI_FAILURE(status)) {
296                 acpi_handle_warn(handle,
297                         "Status check after eject failed (0x%x)\n", status);
298         } else if (sta & ACPI_STA_DEVICE_ENABLED) {
299                 acpi_handle_warn(handle,
300                         "Eject incomplete - status 0x%llx\n", sta);
301         }
302
303         return 0;
304 }
305
306 static int acpi_scan_device_not_present(struct acpi_device *adev)
307 {
308         if (!acpi_device_enumerated(adev)) {
309                 dev_warn(&adev->dev, "Still not present\n");
310                 return -EALREADY;
311         }
312         acpi_bus_trim(adev);
313         return 0;
314 }
315
316 static int acpi_scan_device_check(struct acpi_device *adev)
317 {
318         int error;
319
320         acpi_bus_get_status(adev);
321         if (adev->status.present || adev->status.functional) {
322                 /*
323                  * This function is only called for device objects for which
324                  * matching scan handlers exist.  The only situation in which
325                  * the scan handler is not attached to this device object yet
326                  * is when the device has just appeared (either it wasn't
327                  * present at all before or it was removed and then added
328                  * again).
329                  */
330                 if (adev->handler) {
331                         dev_warn(&adev->dev, "Already enumerated\n");
332                         return -EALREADY;
333                 }
334                 error = acpi_bus_scan(adev->handle);
335                 if (error) {
336                         dev_warn(&adev->dev, "Namespace scan failure\n");
337                         return error;
338                 }
339                 if (!adev->handler) {
340                         dev_warn(&adev->dev, "Enumeration failure\n");
341                         error = -ENODEV;
342                 }
343         } else {
344                 error = acpi_scan_device_not_present(adev);
345         }
346         return error;
347 }
348
349 static int acpi_scan_bus_check(struct acpi_device *adev)
350 {
351         struct acpi_scan_handler *handler = adev->handler;
352         struct acpi_device *child;
353         int error;
354
355         acpi_bus_get_status(adev);
356         if (!(adev->status.present || adev->status.functional)) {
357                 acpi_scan_device_not_present(adev);
358                 return 0;
359         }
360         if (handler && handler->hotplug.scan_dependent)
361                 return handler->hotplug.scan_dependent(adev);
362
363         error = acpi_bus_scan(adev->handle);
364         if (error) {
365                 dev_warn(&adev->dev, "Namespace scan failure\n");
366                 return error;
367         }
368         list_for_each_entry(child, &adev->children, node) {
369                 error = acpi_scan_bus_check(child);
370                 if (error)
371                         return error;
372         }
373         return 0;
374 }
375
376 static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
377 {
378         switch (type) {
379         case ACPI_NOTIFY_BUS_CHECK:
380                 return acpi_scan_bus_check(adev);
381         case ACPI_NOTIFY_DEVICE_CHECK:
382                 return acpi_scan_device_check(adev);
383         case ACPI_NOTIFY_EJECT_REQUEST:
384         case ACPI_OST_EC_OSPM_EJECT:
385                 if (adev->handler && !adev->handler->hotplug.enabled) {
386                         dev_info(&adev->dev, "Eject disabled\n");
387                         return -EPERM;
388                 }
389                 acpi_evaluate_ost(adev->handle, ACPI_NOTIFY_EJECT_REQUEST,
390                                   ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
391                 return acpi_scan_hot_remove(adev);
392         }
393         return -EINVAL;
394 }
395
396 void acpi_device_hotplug(struct acpi_device *adev, u32 src)
397 {
398         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
399         int error = -ENODEV;
400
401         lock_device_hotplug();
402         mutex_lock(&acpi_scan_lock);
403
404         /*
405          * The device object's ACPI handle cannot become invalid as long as we
406          * are holding acpi_scan_lock, but it might have become invalid before
407          * that lock was acquired.
408          */
409         if (adev->handle == INVALID_ACPI_HANDLE)
410                 goto err_out;
411
412         if (adev->flags.is_dock_station) {
413                 error = dock_notify(adev, src);
414         } else if (adev->flags.hotplug_notify) {
415                 error = acpi_generic_hotplug_event(adev, src);
416                 if (error == -EPERM) {
417                         ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
418                         goto err_out;
419                 }
420         } else {
421                 int (*notify)(struct acpi_device *, u32);
422
423                 acpi_lock_hp_context();
424                 notify = adev->hp ? adev->hp->notify : NULL;
425                 acpi_unlock_hp_context();
426                 /*
427                  * There may be additional notify handlers for device objects
428                  * without the .event() callback, so ignore them here.
429                  */
430                 if (notify)
431                         error = notify(adev, src);
432                 else
433                         goto out;
434         }
435         if (!error)
436                 ost_code = ACPI_OST_SC_SUCCESS;
437
438  err_out:
439         acpi_evaluate_ost(adev->handle, src, ost_code, NULL);
440
441  out:
442         acpi_bus_put_acpi_device(adev);
443         mutex_unlock(&acpi_scan_lock);
444         unlock_device_hotplug();
445 }
446
447 static void acpi_free_power_resources_lists(struct acpi_device *device)
448 {
449         int i;
450
451         if (device->wakeup.flags.valid)
452                 acpi_power_resources_list_free(&device->wakeup.resources);
453
454         if (!device->power.flags.power_resources)
455                 return;
456
457         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
458                 struct acpi_device_power_state *ps = &device->power.states[i];
459                 acpi_power_resources_list_free(&ps->resources);
460         }
461 }
462
463 static void acpi_device_release(struct device *dev)
464 {
465         struct acpi_device *acpi_dev = to_acpi_device(dev);
466
467         acpi_free_properties(acpi_dev);
468         acpi_free_pnp_ids(&acpi_dev->pnp);
469         acpi_free_power_resources_lists(acpi_dev);
470         kfree(acpi_dev);
471 }
472
473 static void acpi_device_del(struct acpi_device *device)
474 {
475         struct acpi_device_bus_id *acpi_device_bus_id;
476
477         mutex_lock(&acpi_device_lock);
478         if (device->parent)
479                 list_del(&device->node);
480
481         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
482                 if (!strcmp(acpi_device_bus_id->bus_id,
483                             acpi_device_hid(device))) {
484                         if (acpi_device_bus_id->instance_no > 0)
485                                 acpi_device_bus_id->instance_no--;
486                         else {
487                                 list_del(&acpi_device_bus_id->node);
488                                 kfree(acpi_device_bus_id);
489                         }
490                         break;
491                 }
492
493         list_del(&device->wakeup_list);
494         mutex_unlock(&acpi_device_lock);
495
496         acpi_power_add_remove_device(device, false);
497         acpi_device_remove_files(device);
498         if (device->remove)
499                 device->remove(device);
500
501         device_del(&device->dev);
502 }
503
504 static LIST_HEAD(acpi_device_del_list);
505 static DEFINE_MUTEX(acpi_device_del_lock);
506
507 static void acpi_device_del_work_fn(struct work_struct *work_not_used)
508 {
509         for (;;) {
510                 struct acpi_device *adev;
511
512                 mutex_lock(&acpi_device_del_lock);
513
514                 if (list_empty(&acpi_device_del_list)) {
515                         mutex_unlock(&acpi_device_del_lock);
516                         break;
517                 }
518                 adev = list_first_entry(&acpi_device_del_list,
519                                         struct acpi_device, del_list);
520                 list_del(&adev->del_list);
521
522                 mutex_unlock(&acpi_device_del_lock);
523
524                 acpi_device_del(adev);
525                 /*
526                  * Drop references to all power resources that might have been
527                  * used by the device.
528                  */
529                 acpi_power_transition(adev, ACPI_STATE_D3_COLD);
530                 put_device(&adev->dev);
531         }
532 }
533
534 /**
535  * acpi_scan_drop_device - Drop an ACPI device object.
536  * @handle: Handle of an ACPI namespace node, not used.
537  * @context: Address of the ACPI device object to drop.
538  *
539  * This is invoked by acpi_ns_delete_node() during the removal of the ACPI
540  * namespace node the device object pointed to by @context is attached to.
541  *
542  * The unregistration is carried out asynchronously to avoid running
543  * acpi_device_del() under the ACPICA's namespace mutex and the list is used to
544  * ensure the correct ordering (the device objects must be unregistered in the
545  * same order in which the corresponding namespace nodes are deleted).
546  */
547 static void acpi_scan_drop_device(acpi_handle handle, void *context)
548 {
549         static DECLARE_WORK(work, acpi_device_del_work_fn);
550         struct acpi_device *adev = context;
551
552         mutex_lock(&acpi_device_del_lock);
553
554         /*
555          * Use the ACPI hotplug workqueue which is ordered, so this work item
556          * won't run after any hotplug work items submitted subsequently.  That
557          * prevents attempts to register device objects identical to those being
558          * deleted from happening concurrently (such attempts result from
559          * hotplug events handled via the ACPI hotplug workqueue).  It also will
560          * run after all of the work items submitted previosuly, which helps
561          * those work items to ensure that they are not accessing stale device
562          * objects.
563          */
564         if (list_empty(&acpi_device_del_list))
565                 acpi_queue_hotplug_work(&work);
566
567         list_add_tail(&adev->del_list, &acpi_device_del_list);
568         /* Make acpi_ns_validate_handle() return NULL for this handle. */
569         adev->handle = INVALID_ACPI_HANDLE;
570
571         mutex_unlock(&acpi_device_del_lock);
572 }
573
574 static int acpi_get_device_data(acpi_handle handle, struct acpi_device **device,
575                                 void (*callback)(void *))
576 {
577         acpi_status status;
578
579         if (!device)
580                 return -EINVAL;
581
582         status = acpi_get_data_full(handle, acpi_scan_drop_device,
583                                     (void **)device, callback);
584         if (ACPI_FAILURE(status) || !*device) {
585                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
586                                   handle));
587                 return -ENODEV;
588         }
589         return 0;
590 }
591
592 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
593 {
594         return acpi_get_device_data(handle, device, NULL);
595 }
596 EXPORT_SYMBOL(acpi_bus_get_device);
597
598 static void get_acpi_device(void *dev)
599 {
600         if (dev)
601                 get_device(&((struct acpi_device *)dev)->dev);
602 }
603
604 struct acpi_device *acpi_bus_get_acpi_device(acpi_handle handle)
605 {
606         struct acpi_device *adev = NULL;
607
608         acpi_get_device_data(handle, &adev, get_acpi_device);
609         return adev;
610 }
611
612 void acpi_bus_put_acpi_device(struct acpi_device *adev)
613 {
614         put_device(&adev->dev);
615 }
616
617 int acpi_device_add(struct acpi_device *device,
618                     void (*release)(struct device *))
619 {
620         int result;
621         struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
622         int found = 0;
623
624         if (device->handle) {
625                 acpi_status status;
626
627                 status = acpi_attach_data(device->handle, acpi_scan_drop_device,
628                                           device);
629                 if (ACPI_FAILURE(status)) {
630                         acpi_handle_err(device->handle,
631                                         "Unable to attach device data\n");
632                         return -ENODEV;
633                 }
634         }
635
636         /*
637          * Linkage
638          * -------
639          * Link this device to its parent and siblings.
640          */
641         INIT_LIST_HEAD(&device->children);
642         INIT_LIST_HEAD(&device->node);
643         INIT_LIST_HEAD(&device->wakeup_list);
644         INIT_LIST_HEAD(&device->physical_node_list);
645         INIT_LIST_HEAD(&device->del_list);
646         mutex_init(&device->physical_node_lock);
647
648         new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
649         if (!new_bus_id) {
650                 pr_err(PREFIX "Memory allocation error\n");
651                 result = -ENOMEM;
652                 goto err_detach;
653         }
654
655         mutex_lock(&acpi_device_lock);
656         /*
657          * Find suitable bus_id and instance number in acpi_bus_id_list
658          * If failed, create one and link it into acpi_bus_id_list
659          */
660         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
661                 if (!strcmp(acpi_device_bus_id->bus_id,
662                             acpi_device_hid(device))) {
663                         acpi_device_bus_id->instance_no++;
664                         found = 1;
665                         kfree(new_bus_id);
666                         break;
667                 }
668         }
669         if (!found) {
670                 acpi_device_bus_id = new_bus_id;
671                 strcpy(acpi_device_bus_id->bus_id, acpi_device_hid(device));
672                 acpi_device_bus_id->instance_no = 0;
673                 list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
674         }
675         dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
676
677         if (device->parent)
678                 list_add_tail(&device->node, &device->parent->children);
679
680         if (device->wakeup.flags.valid)
681                 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
682         mutex_unlock(&acpi_device_lock);
683
684         if (device->parent)
685                 device->dev.parent = &device->parent->dev;
686         device->dev.bus = &acpi_bus_type;
687         device->dev.release = release;
688         result = device_add(&device->dev);
689         if (result) {
690                 dev_err(&device->dev, "Error registering device\n");
691                 goto err;
692         }
693
694         result = acpi_device_setup_files(device);
695         if (result)
696                 printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n",
697                        dev_name(&device->dev));
698
699         return 0;
700
701  err:
702         mutex_lock(&acpi_device_lock);
703         if (device->parent)
704                 list_del(&device->node);
705         list_del(&device->wakeup_list);
706         mutex_unlock(&acpi_device_lock);
707
708  err_detach:
709         acpi_detach_data(device->handle, acpi_scan_drop_device);
710         return result;
711 }
712
713 /* --------------------------------------------------------------------------
714                                  Device Enumeration
715    -------------------------------------------------------------------------- */
716 static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
717 {
718         struct acpi_device *device = NULL;
719         acpi_status status;
720
721         /*
722          * Fixed hardware devices do not appear in the namespace and do not
723          * have handles, but we fabricate acpi_devices for them, so we have
724          * to deal with them specially.
725          */
726         if (!handle)
727                 return acpi_root;
728
729         do {
730                 status = acpi_get_parent(handle, &handle);
731                 if (ACPI_FAILURE(status))
732                         return status == AE_NULL_ENTRY ? NULL : acpi_root;
733         } while (acpi_bus_get_device(handle, &device));
734         return device;
735 }
736
737 acpi_status
738 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
739 {
740         acpi_status status;
741         acpi_handle tmp;
742         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
743         union acpi_object *obj;
744
745         status = acpi_get_handle(handle, "_EJD", &tmp);
746         if (ACPI_FAILURE(status))
747                 return status;
748
749         status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
750         if (ACPI_SUCCESS(status)) {
751                 obj = buffer.pointer;
752                 status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
753                                          ejd);
754                 kfree(buffer.pointer);
755         }
756         return status;
757 }
758 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
759
760 static int acpi_bus_extract_wakeup_device_power_package(acpi_handle handle,
761                                         struct acpi_device_wakeup *wakeup)
762 {
763         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
764         union acpi_object *package = NULL;
765         union acpi_object *element = NULL;
766         acpi_status status;
767         int err = -ENODATA;
768
769         if (!wakeup)
770                 return -EINVAL;
771
772         INIT_LIST_HEAD(&wakeup->resources);
773
774         /* _PRW */
775         status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
776         if (ACPI_FAILURE(status)) {
777                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
778                 return err;
779         }
780
781         package = (union acpi_object *)buffer.pointer;
782
783         if (!package || package->package.count < 2)
784                 goto out;
785
786         element = &(package->package.elements[0]);
787         if (!element)
788                 goto out;
789
790         if (element->type == ACPI_TYPE_PACKAGE) {
791                 if ((element->package.count < 2) ||
792                     (element->package.elements[0].type !=
793                      ACPI_TYPE_LOCAL_REFERENCE)
794                     || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
795                         goto out;
796
797                 wakeup->gpe_device =
798                     element->package.elements[0].reference.handle;
799                 wakeup->gpe_number =
800                     (u32) element->package.elements[1].integer.value;
801         } else if (element->type == ACPI_TYPE_INTEGER) {
802                 wakeup->gpe_device = NULL;
803                 wakeup->gpe_number = element->integer.value;
804         } else {
805                 goto out;
806         }
807
808         element = &(package->package.elements[1]);
809         if (element->type != ACPI_TYPE_INTEGER)
810                 goto out;
811
812         wakeup->sleep_state = element->integer.value;
813
814         err = acpi_extract_power_resources(package, 2, &wakeup->resources);
815         if (err)
816                 goto out;
817
818         if (!list_empty(&wakeup->resources)) {
819                 int sleep_state;
820
821                 err = acpi_power_wakeup_list_init(&wakeup->resources,
822                                                   &sleep_state);
823                 if (err) {
824                         acpi_handle_warn(handle, "Retrieving current states "
825                                          "of wakeup power resources failed\n");
826                         acpi_power_resources_list_free(&wakeup->resources);
827                         goto out;
828                 }
829                 if (sleep_state < wakeup->sleep_state) {
830                         acpi_handle_warn(handle, "Overriding _PRW sleep state "
831                                          "(S%d) by S%d from power resources\n",
832                                          (int)wakeup->sleep_state, sleep_state);
833                         wakeup->sleep_state = sleep_state;
834                 }
835         }
836
837  out:
838         kfree(buffer.pointer);
839         return err;
840 }
841
842 static void acpi_wakeup_gpe_init(struct acpi_device *device)
843 {
844         static const struct acpi_device_id button_device_ids[] = {
845                 {"PNP0C0C", 0},
846                 {"PNP0C0D", 0},
847                 {"PNP0C0E", 0},
848                 {"", 0},
849         };
850         struct acpi_device_wakeup *wakeup = &device->wakeup;
851         acpi_status status;
852         acpi_event_status event_status;
853
854         wakeup->flags.notifier_present = 0;
855
856         /* Power button, Lid switch always enable wakeup */
857         if (!acpi_match_device_ids(device, button_device_ids)) {
858                 wakeup->flags.run_wake = 1;
859                 if (!acpi_match_device_ids(device, &button_device_ids[1])) {
860                         /* Do not use Lid/sleep button for S5 wakeup */
861                         if (wakeup->sleep_state == ACPI_STATE_S5)
862                                 wakeup->sleep_state = ACPI_STATE_S4;
863                 }
864                 acpi_mark_gpe_for_wake(wakeup->gpe_device, wakeup->gpe_number);
865                 device_set_wakeup_capable(&device->dev, true);
866                 return;
867         }
868
869         acpi_setup_gpe_for_wake(device->handle, wakeup->gpe_device,
870                                 wakeup->gpe_number);
871         status = acpi_get_gpe_status(wakeup->gpe_device, wakeup->gpe_number,
872                                      &event_status);
873         if (ACPI_FAILURE(status))
874                 return;
875
876         wakeup->flags.run_wake = !!(event_status & ACPI_EVENT_FLAG_HAS_HANDLER);
877 }
878
879 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
880 {
881         int err;
882
883         /* Presence of _PRW indicates wake capable */
884         if (!acpi_has_method(device->handle, "_PRW"))
885                 return;
886
887         err = acpi_bus_extract_wakeup_device_power_package(device->handle,
888                                                            &device->wakeup);
889         if (err) {
890                 dev_err(&device->dev, "_PRW evaluation error: %d\n", err);
891                 return;
892         }
893
894         device->wakeup.flags.valid = 1;
895         device->wakeup.prepare_count = 0;
896         acpi_wakeup_gpe_init(device);
897         /* Call _PSW/_DSW object to disable its ability to wake the sleeping
898          * system for the ACPI device with the _PRW object.
899          * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW.
900          * So it is necessary to call _DSW object first. Only when it is not
901          * present will the _PSW object used.
902          */
903         err = acpi_device_sleep_wake(device, 0, 0, 0);
904         if (err)
905                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
906                                 "error in _DSW or _PSW evaluation\n"));
907 }
908
909 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
910 {
911         struct acpi_device_power_state *ps = &device->power.states[state];
912         char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
913         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
914         acpi_status status;
915
916         INIT_LIST_HEAD(&ps->resources);
917
918         /* Evaluate "_PRx" to get referenced power resources */
919         status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
920         if (ACPI_SUCCESS(status)) {
921                 union acpi_object *package = buffer.pointer;
922
923                 if (buffer.length && package
924                     && package->type == ACPI_TYPE_PACKAGE
925                     && package->package.count) {
926                         int err = acpi_extract_power_resources(package, 0,
927                                                                &ps->resources);
928                         if (!err)
929                                 device->power.flags.power_resources = 1;
930                 }
931                 ACPI_FREE(buffer.pointer);
932         }
933
934         /* Evaluate "_PSx" to see if we can do explicit sets */
935         pathname[2] = 'S';
936         if (acpi_has_method(device->handle, pathname))
937                 ps->flags.explicit_set = 1;
938
939         /* State is valid if there are means to put the device into it. */
940         if (!list_empty(&ps->resources) || ps->flags.explicit_set)
941                 ps->flags.valid = 1;
942
943         ps->power = -1;         /* Unknown - driver assigned */
944         ps->latency = -1;       /* Unknown - driver assigned */
945 }
946
947 static void acpi_bus_get_power_flags(struct acpi_device *device)
948 {
949         u32 i;
950
951         /* Presence of _PS0|_PR0 indicates 'power manageable' */
952         if (!acpi_has_method(device->handle, "_PS0") &&
953             !acpi_has_method(device->handle, "_PR0"))
954                 return;
955
956         device->flags.power_manageable = 1;
957
958         /*
959          * Power Management Flags
960          */
961         if (acpi_has_method(device->handle, "_PSC"))
962                 device->power.flags.explicit_get = 1;
963
964         if (acpi_has_method(device->handle, "_IRC"))
965                 device->power.flags.inrush_current = 1;
966
967         if (acpi_has_method(device->handle, "_DSW"))
968                 device->power.flags.dsw_present = 1;
969
970         /*
971          * Enumerate supported power management states
972          */
973         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
974                 acpi_bus_init_power_state(device, i);
975
976         INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
977         if (!list_empty(&device->power.states[ACPI_STATE_D3_HOT].resources))
978                 device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
979
980         /* Set defaults for D0 and D3hot states (always valid) */
981         device->power.states[ACPI_STATE_D0].flags.valid = 1;
982         device->power.states[ACPI_STATE_D0].power = 100;
983         device->power.states[ACPI_STATE_D3_HOT].flags.valid = 1;
984
985         if (acpi_bus_init_power(device))
986                 device->flags.power_manageable = 0;
987 }
988
989 static void acpi_bus_get_flags(struct acpi_device *device)
990 {
991         /* Presence of _STA indicates 'dynamic_status' */
992         if (acpi_has_method(device->handle, "_STA"))
993                 device->flags.dynamic_status = 1;
994
995         /* Presence of _RMV indicates 'removable' */
996         if (acpi_has_method(device->handle, "_RMV"))
997                 device->flags.removable = 1;
998
999         /* Presence of _EJD|_EJ0 indicates 'ejectable' */
1000         if (acpi_has_method(device->handle, "_EJD") ||
1001             acpi_has_method(device->handle, "_EJ0"))
1002                 device->flags.ejectable = 1;
1003 }
1004
1005 static void acpi_device_get_busid(struct acpi_device *device)
1006 {
1007         char bus_id[5] = { '?', 0 };
1008         struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1009         int i = 0;
1010
1011         /*
1012          * Bus ID
1013          * ------
1014          * The device's Bus ID is simply the object name.
1015          * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1016          */
1017         if (ACPI_IS_ROOT_DEVICE(device)) {
1018                 strcpy(device->pnp.bus_id, "ACPI");
1019                 return;
1020         }
1021
1022         switch (device->device_type) {
1023         case ACPI_BUS_TYPE_POWER_BUTTON:
1024                 strcpy(device->pnp.bus_id, "PWRF");
1025                 break;
1026         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1027                 strcpy(device->pnp.bus_id, "SLPF");
1028                 break;
1029         default:
1030                 acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1031                 /* Clean up trailing underscores (if any) */
1032                 for (i = 3; i > 1; i--) {
1033                         if (bus_id[i] == '_')
1034                                 bus_id[i] = '\0';
1035                         else
1036                                 break;
1037                 }
1038                 strcpy(device->pnp.bus_id, bus_id);
1039                 break;
1040         }
1041 }
1042
1043 /*
1044  * acpi_ata_match - see if an acpi object is an ATA device
1045  *
1046  * If an acpi object has one of the ACPI ATA methods defined,
1047  * then we can safely call it an ATA device.
1048  */
1049 bool acpi_ata_match(acpi_handle handle)
1050 {
1051         return acpi_has_method(handle, "_GTF") ||
1052                acpi_has_method(handle, "_GTM") ||
1053                acpi_has_method(handle, "_STM") ||
1054                acpi_has_method(handle, "_SDD");
1055 }
1056
1057 /*
1058  * acpi_bay_match - see if an acpi object is an ejectable driver bay
1059  *
1060  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1061  * then we can safely call it an ejectable drive bay
1062  */
1063 bool acpi_bay_match(acpi_handle handle)
1064 {
1065         acpi_handle phandle;
1066
1067         if (!acpi_has_method(handle, "_EJ0"))
1068                 return false;
1069         if (acpi_ata_match(handle))
1070                 return true;
1071         if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
1072                 return false;
1073
1074         return acpi_ata_match(phandle);
1075 }
1076
1077 bool acpi_device_is_battery(struct acpi_device *adev)
1078 {
1079         struct acpi_hardware_id *hwid;
1080
1081         list_for_each_entry(hwid, &adev->pnp.ids, list)
1082                 if (!strcmp("PNP0C0A", hwid->id))
1083                         return true;
1084
1085         return false;
1086 }
1087
1088 static bool is_ejectable_bay(struct acpi_device *adev)
1089 {
1090         acpi_handle handle = adev->handle;
1091
1092         if (acpi_has_method(handle, "_EJ0") && acpi_device_is_battery(adev))
1093                 return true;
1094
1095         return acpi_bay_match(handle);
1096 }
1097
1098 /*
1099  * acpi_dock_match - see if an acpi object has a _DCK method
1100  */
1101 bool acpi_dock_match(acpi_handle handle)
1102 {
1103         return acpi_has_method(handle, "_DCK");
1104 }
1105
1106 static acpi_status
1107 acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
1108                           void **return_value)
1109 {
1110         long *cap = context;
1111
1112         if (acpi_has_method(handle, "_BCM") &&
1113             acpi_has_method(handle, "_BCL")) {
1114                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found generic backlight "
1115                                   "support\n"));
1116                 *cap |= ACPI_VIDEO_BACKLIGHT;
1117                 if (!acpi_has_method(handle, "_BQC"))
1118                         printk(KERN_WARNING FW_BUG PREFIX "No _BQC method, "
1119                                 "cannot determine initial brightness\n");
1120                 /* We have backlight support, no need to scan further */
1121                 return AE_CTRL_TERMINATE;
1122         }
1123         return 0;
1124 }
1125
1126 /* Returns true if the ACPI object is a video device which can be
1127  * handled by video.ko.
1128  * The device will get a Linux specific CID added in scan.c to
1129  * identify the device as an ACPI graphics device
1130  * Be aware that the graphics device may not be physically present
1131  * Use acpi_video_get_capabilities() to detect general ACPI video
1132  * capabilities of present cards
1133  */
1134 long acpi_is_video_device(acpi_handle handle)
1135 {
1136         long video_caps = 0;
1137
1138         /* Is this device able to support video switching ? */
1139         if (acpi_has_method(handle, "_DOD") || acpi_has_method(handle, "_DOS"))
1140                 video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
1141
1142         /* Is this device able to retrieve a video ROM ? */
1143         if (acpi_has_method(handle, "_ROM"))
1144                 video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
1145
1146         /* Is this device able to configure which video head to be POSTed ? */
1147         if (acpi_has_method(handle, "_VPO") &&
1148             acpi_has_method(handle, "_GPD") &&
1149             acpi_has_method(handle, "_SPD"))
1150                 video_caps |= ACPI_VIDEO_DEVICE_POSTING;
1151
1152         /* Only check for backlight functionality if one of the above hit. */
1153         if (video_caps)
1154                 acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
1155                                     ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
1156                                     &video_caps, NULL);
1157
1158         return video_caps;
1159 }
1160 EXPORT_SYMBOL(acpi_is_video_device);
1161
1162 const char *acpi_device_hid(struct acpi_device *device)
1163 {
1164         struct acpi_hardware_id *hid;
1165
1166         if (list_empty(&device->pnp.ids))
1167                 return dummy_hid;
1168
1169         hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
1170         return hid->id;
1171 }
1172 EXPORT_SYMBOL(acpi_device_hid);
1173
1174 static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
1175 {
1176         struct acpi_hardware_id *id;
1177
1178         id = kmalloc(sizeof(*id), GFP_KERNEL);
1179         if (!id)
1180                 return;
1181
1182         id->id = kstrdup_const(dev_id, GFP_KERNEL);
1183         if (!id->id) {
1184                 kfree(id);
1185                 return;
1186         }
1187
1188         list_add_tail(&id->list, &pnp->ids);
1189         pnp->type.hardware_id = 1;
1190 }
1191
1192 /*
1193  * Old IBM workstations have a DSDT bug wherein the SMBus object
1194  * lacks the SMBUS01 HID and the methods do not have the necessary "_"
1195  * prefix.  Work around this.
1196  */
1197 static bool acpi_ibm_smbus_match(acpi_handle handle)
1198 {
1199         char node_name[ACPI_PATH_SEGMENT_LENGTH];
1200         struct acpi_buffer path = { sizeof(node_name), node_name };
1201
1202         if (!dmi_name_in_vendors("IBM"))
1203                 return false;
1204
1205         /* Look for SMBS object */
1206         if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
1207             strcmp("SMBS", path.pointer))
1208                 return false;
1209
1210         /* Does it have the necessary (but misnamed) methods? */
1211         if (acpi_has_method(handle, "SBI") &&
1212             acpi_has_method(handle, "SBR") &&
1213             acpi_has_method(handle, "SBW"))
1214                 return true;
1215
1216         return false;
1217 }
1218
1219 static bool acpi_object_is_system_bus(acpi_handle handle)
1220 {
1221         acpi_handle tmp;
1222
1223         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_SB", &tmp)) &&
1224             tmp == handle)
1225                 return true;
1226         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_TZ", &tmp)) &&
1227             tmp == handle)
1228                 return true;
1229
1230         return false;
1231 }
1232
1233 static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
1234                                 int device_type)
1235 {
1236         acpi_status status;
1237         struct acpi_device_info *info;
1238         struct acpi_pnp_device_id_list *cid_list;
1239         int i;
1240
1241         switch (device_type) {
1242         case ACPI_BUS_TYPE_DEVICE:
1243                 if (handle == ACPI_ROOT_OBJECT) {
1244                         acpi_add_id(pnp, ACPI_SYSTEM_HID);
1245                         break;
1246                 }
1247
1248                 status = acpi_get_object_info(handle, &info);
1249                 if (ACPI_FAILURE(status)) {
1250                         pr_err(PREFIX "%s: Error reading device info\n",
1251                                         __func__);
1252                         return;
1253                 }
1254
1255                 if (info->valid & ACPI_VALID_HID) {
1256                         acpi_add_id(pnp, info->hardware_id.string);
1257                         pnp->type.platform_id = 1;
1258                 }
1259                 if (info->valid & ACPI_VALID_CID) {
1260                         cid_list = &info->compatible_id_list;
1261                         for (i = 0; i < cid_list->count; i++)
1262                                 acpi_add_id(pnp, cid_list->ids[i].string);
1263                 }
1264                 if (info->valid & ACPI_VALID_ADR) {
1265                         pnp->bus_address = info->address;
1266                         pnp->type.bus_address = 1;
1267                 }
1268                 if (info->valid & ACPI_VALID_UID)
1269                         pnp->unique_id = kstrdup(info->unique_id.string,
1270                                                         GFP_KERNEL);
1271                 if (info->valid & ACPI_VALID_CLS)
1272                         acpi_add_id(pnp, info->class_code.string);
1273
1274                 kfree(info);
1275
1276                 /*
1277                  * Some devices don't reliably have _HIDs & _CIDs, so add
1278                  * synthetic HIDs to make sure drivers can find them.
1279                  */
1280                 if (acpi_is_video_device(handle))
1281                         acpi_add_id(pnp, ACPI_VIDEO_HID);
1282                 else if (acpi_bay_match(handle))
1283                         acpi_add_id(pnp, ACPI_BAY_HID);
1284                 else if (acpi_dock_match(handle))
1285                         acpi_add_id(pnp, ACPI_DOCK_HID);
1286                 else if (acpi_ibm_smbus_match(handle))
1287                         acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
1288                 else if (list_empty(&pnp->ids) &&
1289                          acpi_object_is_system_bus(handle)) {
1290                         /* \_SB, \_TZ, LNXSYBUS */
1291                         acpi_add_id(pnp, ACPI_BUS_HID);
1292                         strcpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
1293                         strcpy(pnp->device_class, ACPI_BUS_CLASS);
1294                 }
1295
1296                 break;
1297         case ACPI_BUS_TYPE_POWER:
1298                 acpi_add_id(pnp, ACPI_POWER_HID);
1299                 break;
1300         case ACPI_BUS_TYPE_PROCESSOR:
1301                 acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
1302                 break;
1303         case ACPI_BUS_TYPE_THERMAL:
1304                 acpi_add_id(pnp, ACPI_THERMAL_HID);
1305                 break;
1306         case ACPI_BUS_TYPE_POWER_BUTTON:
1307                 acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
1308                 break;
1309         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1310                 acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
1311                 break;
1312         }
1313 }
1314
1315 void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
1316 {
1317         struct acpi_hardware_id *id, *tmp;
1318
1319         list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
1320                 kfree_const(id->id);
1321                 kfree(id);
1322         }
1323         kfree(pnp->unique_id);
1324 }
1325
1326 /**
1327  * acpi_dma_supported - Check DMA support for the specified device.
1328  * @adev: The pointer to acpi device
1329  *
1330  * Return false if DMA is not supported. Otherwise, return true
1331  */
1332 bool acpi_dma_supported(struct acpi_device *adev)
1333 {
1334         if (!adev)
1335                 return false;
1336
1337         if (adev->flags.cca_seen)
1338                 return true;
1339
1340         /*
1341         * Per ACPI 6.0 sec 6.2.17, assume devices can do cache-coherent
1342         * DMA on "Intel platforms".  Presumably that includes all x86 and
1343         * ia64, and other arches will set CONFIG_ACPI_CCA_REQUIRED=y.
1344         */
1345         if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1346                 return true;
1347
1348         return false;
1349 }
1350
1351 /**
1352  * acpi_get_dma_attr - Check the supported DMA attr for the specified device.
1353  * @adev: The pointer to acpi device
1354  *
1355  * Return enum dev_dma_attr.
1356  */
1357 enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev)
1358 {
1359         if (!acpi_dma_supported(adev))
1360                 return DEV_DMA_NOT_SUPPORTED;
1361
1362         if (adev->flags.coherent_dma)
1363                 return DEV_DMA_COHERENT;
1364         else
1365                 return DEV_DMA_NON_COHERENT;
1366 }
1367
1368 static void acpi_init_coherency(struct acpi_device *adev)
1369 {
1370         unsigned long long cca = 0;
1371         acpi_status status;
1372         struct acpi_device *parent = adev->parent;
1373
1374         if (parent && parent->flags.cca_seen) {
1375                 /*
1376                  * From ACPI spec, OSPM will ignore _CCA if an ancestor
1377                  * already saw one.
1378                  */
1379                 adev->flags.cca_seen = 1;
1380                 cca = parent->flags.coherent_dma;
1381         } else {
1382                 status = acpi_evaluate_integer(adev->handle, "_CCA",
1383                                                NULL, &cca);
1384                 if (ACPI_SUCCESS(status))
1385                         adev->flags.cca_seen = 1;
1386                 else if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1387                         /*
1388                          * If architecture does not specify that _CCA is
1389                          * required for DMA-able devices (e.g. x86),
1390                          * we default to _CCA=1.
1391                          */
1392                         cca = 1;
1393                 else
1394                         acpi_handle_debug(adev->handle,
1395                                           "ACPI device is missing _CCA.\n");
1396         }
1397
1398         adev->flags.coherent_dma = cca;
1399 }
1400
1401 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
1402                              int type, unsigned long long sta)
1403 {
1404         INIT_LIST_HEAD(&device->pnp.ids);
1405         device->device_type = type;
1406         device->handle = handle;
1407         device->parent = acpi_bus_get_parent(handle);
1408         device->fwnode.type = FWNODE_ACPI;
1409         acpi_set_device_status(device, sta);
1410         acpi_device_get_busid(device);
1411         acpi_set_pnp_ids(handle, &device->pnp, type);
1412         acpi_init_properties(device);
1413         acpi_bus_get_flags(device);
1414         device->flags.match_driver = false;
1415         device->flags.initialized = true;
1416         device->flags.visited = false;
1417         device_initialize(&device->dev);
1418         dev_set_uevent_suppress(&device->dev, true);
1419         acpi_init_coherency(device);
1420 }
1421
1422 void acpi_device_add_finalize(struct acpi_device *device)
1423 {
1424         dev_set_uevent_suppress(&device->dev, false);
1425         kobject_uevent(&device->dev.kobj, KOBJ_ADD);
1426 }
1427
1428 static int acpi_add_single_object(struct acpi_device **child,
1429                                   acpi_handle handle, int type,
1430                                   unsigned long long sta)
1431 {
1432         int result;
1433         struct acpi_device *device;
1434         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1435
1436         device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1437         if (!device) {
1438                 printk(KERN_ERR PREFIX "Memory allocation error\n");
1439                 return -ENOMEM;
1440         }
1441
1442         acpi_init_device_object(device, handle, type, sta);
1443         acpi_bus_get_power_flags(device);
1444         acpi_bus_get_wakeup_device_flags(device);
1445
1446         result = acpi_device_add(device, acpi_device_release);
1447         if (result) {
1448                 acpi_device_release(&device->dev);
1449                 return result;
1450         }
1451
1452         acpi_power_add_remove_device(device, true);
1453         acpi_device_add_finalize(device);
1454         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
1455         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Added %s [%s] parent %s\n",
1456                 dev_name(&device->dev), (char *) buffer.pointer,
1457                 device->parent ? dev_name(&device->parent->dev) : "(null)"));
1458         kfree(buffer.pointer);
1459         *child = device;
1460         return 0;
1461 }
1462
1463 static acpi_status acpi_get_resource_memory(struct acpi_resource *ares,
1464                                             void *context)
1465 {
1466         struct resource *res = context;
1467
1468         if (acpi_dev_resource_memory(ares, res))
1469                 return AE_CTRL_TERMINATE;
1470
1471         return AE_OK;
1472 }
1473
1474 static bool acpi_device_should_be_hidden(acpi_handle handle)
1475 {
1476         acpi_status status;
1477         struct resource res;
1478
1479         /* Check if it should ignore the UART device */
1480         if (!(spcr_uart_addr && acpi_has_method(handle, METHOD_NAME__CRS)))
1481                 return false;
1482
1483         /*
1484          * The UART device described in SPCR table is assumed to have only one
1485          * memory resource present. So we only look for the first one here.
1486          */
1487         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1488                                      acpi_get_resource_memory, &res);
1489         if (ACPI_FAILURE(status) || res.start != spcr_uart_addr)
1490                 return false;
1491
1492         acpi_handle_info(handle, "The UART device @%pa in SPCR table will be hidden\n",
1493                          &res.start);
1494
1495         return true;
1496 }
1497
1498 static int acpi_bus_type_and_status(acpi_handle handle, int *type,
1499                                     unsigned long long *sta)
1500 {
1501         acpi_status status;
1502         acpi_object_type acpi_type;
1503
1504         status = acpi_get_type(handle, &acpi_type);
1505         if (ACPI_FAILURE(status))
1506                 return -ENODEV;
1507
1508         switch (acpi_type) {
1509         case ACPI_TYPE_ANY:             /* for ACPI_ROOT_OBJECT */
1510         case ACPI_TYPE_DEVICE:
1511                 if (acpi_device_should_be_hidden(handle))
1512                         return -ENODEV;
1513
1514                 *type = ACPI_BUS_TYPE_DEVICE;
1515                 status = acpi_bus_get_status_handle(handle, sta);
1516                 if (ACPI_FAILURE(status))
1517                         *sta = 0;
1518                 break;
1519         case ACPI_TYPE_PROCESSOR:
1520                 *type = ACPI_BUS_TYPE_PROCESSOR;
1521                 status = acpi_bus_get_status_handle(handle, sta);
1522                 if (ACPI_FAILURE(status))
1523                         return -ENODEV;
1524                 break;
1525         case ACPI_TYPE_THERMAL:
1526                 *type = ACPI_BUS_TYPE_THERMAL;
1527                 *sta = ACPI_STA_DEFAULT;
1528                 break;
1529         case ACPI_TYPE_POWER:
1530                 *type = ACPI_BUS_TYPE_POWER;
1531                 *sta = ACPI_STA_DEFAULT;
1532                 break;
1533         default:
1534                 return -ENODEV;
1535         }
1536
1537         return 0;
1538 }
1539
1540 bool acpi_device_is_present(struct acpi_device *adev)
1541 {
1542         if (adev->status.present || adev->status.functional)
1543                 return true;
1544
1545         adev->flags.initialized = false;
1546         return false;
1547 }
1548
1549 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
1550                                        const char *idstr,
1551                                        const struct acpi_device_id **matchid)
1552 {
1553         const struct acpi_device_id *devid;
1554
1555         if (handler->match)
1556                 return handler->match(idstr, matchid);
1557
1558         for (devid = handler->ids; devid->id[0]; devid++)
1559                 if (!strcmp((char *)devid->id, idstr)) {
1560                         if (matchid)
1561                                 *matchid = devid;
1562
1563                         return true;
1564                 }
1565
1566         return false;
1567 }
1568
1569 static struct acpi_scan_handler *acpi_scan_match_handler(const char *idstr,
1570                                         const struct acpi_device_id **matchid)
1571 {
1572         struct acpi_scan_handler *handler;
1573
1574         list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
1575                 if (acpi_scan_handler_matching(handler, idstr, matchid))
1576                         return handler;
1577
1578         return NULL;
1579 }
1580
1581 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
1582 {
1583         if (!!hotplug->enabled == !!val)
1584                 return;
1585
1586         mutex_lock(&acpi_scan_lock);
1587
1588         hotplug->enabled = val;
1589
1590         mutex_unlock(&acpi_scan_lock);
1591 }
1592
1593 static void acpi_scan_init_hotplug(struct acpi_device *adev)
1594 {
1595         struct acpi_hardware_id *hwid;
1596
1597         if (acpi_dock_match(adev->handle) || is_ejectable_bay(adev)) {
1598                 acpi_dock_add(adev);
1599                 return;
1600         }
1601         list_for_each_entry(hwid, &adev->pnp.ids, list) {
1602                 struct acpi_scan_handler *handler;
1603
1604                 handler = acpi_scan_match_handler(hwid->id, NULL);
1605                 if (handler) {
1606                         adev->flags.hotplug_notify = true;
1607                         break;
1608                 }
1609         }
1610 }
1611
1612 static void acpi_device_dep_initialize(struct acpi_device *adev)
1613 {
1614         struct acpi_dep_data *dep;
1615         struct acpi_handle_list dep_devices;
1616         acpi_status status;
1617         int i;
1618
1619         if (!acpi_has_method(adev->handle, "_DEP"))
1620                 return;
1621
1622         status = acpi_evaluate_reference(adev->handle, "_DEP", NULL,
1623                                         &dep_devices);
1624         if (ACPI_FAILURE(status)) {
1625                 dev_dbg(&adev->dev, "Failed to evaluate _DEP.\n");
1626                 return;
1627         }
1628
1629         for (i = 0; i < dep_devices.count; i++) {
1630                 struct acpi_device_info *info;
1631                 int skip;
1632
1633                 status = acpi_get_object_info(dep_devices.handles[i], &info);
1634                 if (ACPI_FAILURE(status)) {
1635                         dev_dbg(&adev->dev, "Error reading _DEP device info\n");
1636                         continue;
1637                 }
1638
1639                 /*
1640                  * Skip the dependency of Windows System Power
1641                  * Management Controller
1642                  */
1643                 skip = info->valid & ACPI_VALID_HID &&
1644                         !strcmp(info->hardware_id.string, "INT3396");
1645
1646                 kfree(info);
1647
1648                 if (skip)
1649                         continue;
1650
1651                 dep = kzalloc(sizeof(struct acpi_dep_data), GFP_KERNEL);
1652                 if (!dep)
1653                         return;
1654
1655                 dep->master = dep_devices.handles[i];
1656                 dep->slave  = adev->handle;
1657                 adev->dep_unmet++;
1658
1659                 mutex_lock(&acpi_dep_list_lock);
1660                 list_add_tail(&dep->node , &acpi_dep_list);
1661                 mutex_unlock(&acpi_dep_list_lock);
1662         }
1663 }
1664
1665 static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl_not_used,
1666                                       void *not_used, void **return_value)
1667 {
1668         struct acpi_device *device = NULL;
1669         int type;
1670         unsigned long long sta;
1671         int result;
1672
1673         acpi_bus_get_device(handle, &device);
1674         if (device)
1675                 goto out;
1676
1677         result = acpi_bus_type_and_status(handle, &type, &sta);
1678         if (result)
1679                 return AE_OK;
1680
1681         if (type == ACPI_BUS_TYPE_POWER) {
1682                 acpi_add_power_resource(handle);
1683                 return AE_OK;
1684         }
1685
1686         acpi_add_single_object(&device, handle, type, sta);
1687         if (!device)
1688                 return AE_CTRL_DEPTH;
1689
1690         acpi_scan_init_hotplug(device);
1691         acpi_device_dep_initialize(device);
1692
1693  out:
1694         if (!*return_value)
1695                 *return_value = device;
1696
1697         return AE_OK;
1698 }
1699
1700 static int acpi_check_spi_i2c_slave(struct acpi_resource *ares, void *data)
1701 {
1702         bool *is_spi_i2c_slave_p = data;
1703
1704         if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
1705                 return 1;
1706
1707         /*
1708          * devices that are connected to UART still need to be enumerated to
1709          * platform bus
1710          */
1711         if (ares->data.common_serial_bus.type != ACPI_RESOURCE_SERIAL_TYPE_UART)
1712                 *is_spi_i2c_slave_p = true;
1713
1714          /* no need to do more checking */
1715         return -1;
1716 }
1717
1718 static void acpi_default_enumeration(struct acpi_device *device)
1719 {
1720         struct list_head resource_list;
1721         bool is_spi_i2c_slave = false;
1722
1723         /*
1724          * Do not enemerate SPI/I2C slaves as they will be enuerated by their
1725          * respective parents.
1726          */
1727         INIT_LIST_HEAD(&resource_list);
1728         acpi_dev_get_resources(device, &resource_list, acpi_check_spi_i2c_slave,
1729                                &is_spi_i2c_slave);
1730         acpi_dev_free_resource_list(&resource_list);
1731         if (!is_spi_i2c_slave)
1732                 acpi_create_platform_device(device);
1733 }
1734
1735 static const struct acpi_device_id generic_device_ids[] = {
1736         {ACPI_DT_NAMESPACE_HID, },
1737         {"", },
1738 };
1739
1740 static int acpi_generic_device_attach(struct acpi_device *adev,
1741                                       const struct acpi_device_id *not_used)
1742 {
1743         /*
1744          * Since ACPI_DT_NAMESPACE_HID is the only ID handled here, the test
1745          * below can be unconditional.
1746          */
1747         if (adev->data.of_compatible)
1748                 acpi_default_enumeration(adev);
1749
1750         return 1;
1751 }
1752
1753 static struct acpi_scan_handler generic_device_handler = {
1754         .ids = generic_device_ids,
1755         .attach = acpi_generic_device_attach,
1756 };
1757
1758 static int acpi_scan_attach_handler(struct acpi_device *device)
1759 {
1760         struct acpi_hardware_id *hwid;
1761         int ret = 0;
1762
1763         list_for_each_entry(hwid, &device->pnp.ids, list) {
1764                 const struct acpi_device_id *devid;
1765                 struct acpi_scan_handler *handler;
1766
1767                 handler = acpi_scan_match_handler(hwid->id, &devid);
1768                 if (handler) {
1769                         if (!handler->attach) {
1770                                 device->pnp.type.platform_id = 0;
1771                                 continue;
1772                         }
1773                         device->handler = handler;
1774                         ret = handler->attach(device, devid);
1775                         if (ret > 0)
1776                                 break;
1777
1778                         device->handler = NULL;
1779                         if (ret < 0)
1780                                 break;
1781                 }
1782         }
1783
1784         return ret;
1785 }
1786
1787 static void acpi_bus_attach(struct acpi_device *device)
1788 {
1789         struct acpi_device *child;
1790         acpi_handle ejd;
1791         int ret;
1792
1793         if (ACPI_SUCCESS(acpi_bus_get_ejd(device->handle, &ejd)))
1794                 register_dock_dependent_device(device, ejd);
1795
1796         acpi_bus_get_status(device);
1797         /* Skip devices that are not present. */
1798         if (!acpi_device_is_present(device)) {
1799                 device->flags.visited = false;
1800                 device->flags.power_manageable = 0;
1801                 return;
1802         }
1803         if (device->handler)
1804                 goto ok;
1805
1806         if (!device->flags.initialized) {
1807                 device->flags.power_manageable =
1808                         device->power.states[ACPI_STATE_D0].flags.valid;
1809                 if (acpi_bus_init_power(device))
1810                         device->flags.power_manageable = 0;
1811
1812                 device->flags.initialized = true;
1813         }
1814         device->flags.visited = false;
1815         ret = acpi_scan_attach_handler(device);
1816         if (ret < 0)
1817                 return;
1818
1819         device->flags.match_driver = true;
1820         if (!ret) {
1821                 ret = device_attach(&device->dev);
1822                 if (ret < 0)
1823                         return;
1824
1825                 if (!ret && device->pnp.type.platform_id)
1826                         acpi_default_enumeration(device);
1827         }
1828         device->flags.visited = true;
1829
1830  ok:
1831         list_for_each_entry(child, &device->children, node)
1832                 acpi_bus_attach(child);
1833
1834         if (device->handler && device->handler->hotplug.notify_online)
1835                 device->handler->hotplug.notify_online(device);
1836 }
1837
1838 void acpi_walk_dep_device_list(acpi_handle handle)
1839 {
1840         struct acpi_dep_data *dep, *tmp;
1841         struct acpi_device *adev;
1842
1843         mutex_lock(&acpi_dep_list_lock);
1844         list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
1845                 if (dep->master == handle) {
1846                         acpi_bus_get_device(dep->slave, &adev);
1847                         if (!adev)
1848                                 continue;
1849
1850                         adev->dep_unmet--;
1851                         if (!adev->dep_unmet)
1852                                 acpi_bus_attach(adev);
1853                         list_del(&dep->node);
1854                         kfree(dep);
1855                 }
1856         }
1857         mutex_unlock(&acpi_dep_list_lock);
1858 }
1859 EXPORT_SYMBOL_GPL(acpi_walk_dep_device_list);
1860
1861 /**
1862  * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
1863  * @handle: Root of the namespace scope to scan.
1864  *
1865  * Scan a given ACPI tree (probably recently hot-plugged) and create and add
1866  * found devices.
1867  *
1868  * If no devices were found, -ENODEV is returned, but it does not mean that
1869  * there has been a real error.  There just have been no suitable ACPI objects
1870  * in the table trunk from which the kernel could create a device and add an
1871  * appropriate driver.
1872  *
1873  * Must be called under acpi_scan_lock.
1874  */
1875 int acpi_bus_scan(acpi_handle handle)
1876 {
1877         void *device = NULL;
1878
1879         if (ACPI_SUCCESS(acpi_bus_check_add(handle, 0, NULL, &device)))
1880                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
1881                                     acpi_bus_check_add, NULL, NULL, &device);
1882
1883         if (device) {
1884                 acpi_bus_attach(device);
1885                 return 0;
1886         }
1887         return -ENODEV;
1888 }
1889 EXPORT_SYMBOL(acpi_bus_scan);
1890
1891 /**
1892  * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
1893  * @adev: Root of the ACPI namespace scope to walk.
1894  *
1895  * Must be called under acpi_scan_lock.
1896  */
1897 void acpi_bus_trim(struct acpi_device *adev)
1898 {
1899         struct acpi_scan_handler *handler = adev->handler;
1900         struct acpi_device *child;
1901
1902         list_for_each_entry_reverse(child, &adev->children, node)
1903                 acpi_bus_trim(child);
1904
1905         adev->flags.match_driver = false;
1906         if (handler) {
1907                 if (handler->detach)
1908                         handler->detach(adev);
1909
1910                 adev->handler = NULL;
1911         } else {
1912                 device_release_driver(&adev->dev);
1913         }
1914         /*
1915          * Most likely, the device is going away, so put it into D3cold before
1916          * that.
1917          */
1918         acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
1919         adev->flags.initialized = false;
1920         adev->flags.visited = false;
1921 }
1922 EXPORT_SYMBOL_GPL(acpi_bus_trim);
1923
1924 static int acpi_bus_scan_fixed(void)
1925 {
1926         int result = 0;
1927
1928         /*
1929          * Enumerate all fixed-feature devices.
1930          */
1931         if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
1932                 struct acpi_device *device = NULL;
1933
1934                 result = acpi_add_single_object(&device, NULL,
1935                                                 ACPI_BUS_TYPE_POWER_BUTTON,
1936                                                 ACPI_STA_DEFAULT);
1937                 if (result)
1938                         return result;
1939
1940                 device->flags.match_driver = true;
1941                 result = device_attach(&device->dev);
1942                 if (result < 0)
1943                         return result;
1944
1945                 device_init_wakeup(&device->dev, true);
1946         }
1947
1948         if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
1949                 struct acpi_device *device = NULL;
1950
1951                 result = acpi_add_single_object(&device, NULL,
1952                                                 ACPI_BUS_TYPE_SLEEP_BUTTON,
1953                                                 ACPI_STA_DEFAULT);
1954                 if (result)
1955                         return result;
1956
1957                 device->flags.match_driver = true;
1958                 result = device_attach(&device->dev);
1959         }
1960
1961         return result < 0 ? result : 0;
1962 }
1963
1964 static void __init acpi_get_spcr_uart_addr(void)
1965 {
1966         acpi_status status;
1967         struct acpi_table_spcr *spcr_ptr;
1968
1969         status = acpi_get_table(ACPI_SIG_SPCR, 0,
1970                                 (struct acpi_table_header **)&spcr_ptr);
1971         if (ACPI_SUCCESS(status))
1972                 spcr_uart_addr = spcr_ptr->serial_port.address;
1973         else
1974                 printk(KERN_WARNING PREFIX "STAO table present, but SPCR is missing\n");
1975 }
1976
1977 int __init acpi_scan_init(void)
1978 {
1979         int result;
1980         acpi_status status;
1981         struct acpi_table_stao *stao_ptr;
1982
1983         acpi_pci_root_init();
1984         acpi_pci_link_init();
1985         acpi_processor_init();
1986         acpi_lpss_init();
1987         acpi_apd_init();
1988         acpi_cmos_rtc_init();
1989         acpi_container_init();
1990         acpi_memory_hotplug_init();
1991         acpi_pnp_init();
1992         acpi_int340x_thermal_init();
1993         acpi_amba_init();
1994
1995         acpi_scan_add_handler(&generic_device_handler);
1996
1997         /*
1998          * If there is STAO table, check whether it needs to ignore the UART
1999          * device in SPCR table.
2000          */
2001         status = acpi_get_table(ACPI_SIG_STAO, 0,
2002                                 (struct acpi_table_header **)&stao_ptr);
2003         if (ACPI_SUCCESS(status)) {
2004                 if (stao_ptr->header.length > sizeof(struct acpi_table_stao))
2005                         printk(KERN_INFO PREFIX "STAO Name List not yet supported.");
2006
2007                 if (stao_ptr->ignore_uart)
2008                         acpi_get_spcr_uart_addr();
2009         }
2010
2011         mutex_lock(&acpi_scan_lock);
2012         /*
2013          * Enumerate devices in the ACPI namespace.
2014          */
2015         result = acpi_bus_scan(ACPI_ROOT_OBJECT);
2016         if (result)
2017                 goto out;
2018
2019         result = acpi_bus_get_device(ACPI_ROOT_OBJECT, &acpi_root);
2020         if (result)
2021                 goto out;
2022
2023         /* Fixed feature devices do not exist on HW-reduced platform */
2024         if (!acpi_gbl_reduced_hardware) {
2025                 result = acpi_bus_scan_fixed();
2026                 if (result) {
2027                         acpi_detach_data(acpi_root->handle,
2028                                          acpi_scan_drop_device);
2029                         acpi_device_del(acpi_root);
2030                         put_device(&acpi_root->dev);
2031                         goto out;
2032                 }
2033         }
2034
2035         acpi_update_all_gpes();
2036
2037  out:
2038         mutex_unlock(&acpi_scan_lock);
2039         return result;
2040 }
2041
2042 static struct acpi_probe_entry *ape;
2043 static int acpi_probe_count;
2044 static DEFINE_SPINLOCK(acpi_probe_lock);
2045
2046 static int __init acpi_match_madt(struct acpi_subtable_header *header,
2047                                   const unsigned long end)
2048 {
2049         if (!ape->subtable_valid || ape->subtable_valid(header, ape))
2050                 if (!ape->probe_subtbl(header, end))
2051                         acpi_probe_count++;
2052
2053         return 0;
2054 }
2055
2056 int __init __acpi_probe_device_table(struct acpi_probe_entry *ap_head, int nr)
2057 {
2058         int count = 0;
2059
2060         if (acpi_disabled)
2061                 return 0;
2062
2063         spin_lock(&acpi_probe_lock);
2064         for (ape = ap_head; nr; ape++, nr--) {
2065                 if (ACPI_COMPARE_NAME(ACPI_SIG_MADT, ape->id)) {
2066                         acpi_probe_count = 0;
2067                         acpi_table_parse_madt(ape->type, acpi_match_madt, 0);
2068                         count += acpi_probe_count;
2069                 } else {
2070                         int res;
2071                         res = acpi_table_parse(ape->id, ape->probe_table);
2072                         if (!res)
2073                                 count++;
2074                 }
2075         }
2076         spin_unlock(&acpi_probe_lock);
2077
2078         return count;
2079 }