xref: /openbmc/linux/drivers/acpi/acpica/evxface.c (revision ecba1060)
1 /******************************************************************************
2  *
3  * Module Name: evxface - External interfaces for ACPI events
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2008, Intel Corp.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    substantially similar to the "NO WARRANTY" disclaimer below
19  *    ("Disclaimer") and any redistribution must be conditioned upon
20  *    including a substantially similar Disclaimer requirement for further
21  *    binary redistribution.
22  * 3. Neither the names of the above-listed copyright holders nor the names
23  *    of any contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * Alternatively, this software may be distributed under the terms of the
27  * GNU General Public License ("GPL") version 2 as published by the Free
28  * Software Foundation.
29  *
30  * NO WARRANTY
31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41  * POSSIBILITY OF SUCH DAMAGES.
42  */
43 
44 #include <acpi/acpi.h>
45 #include "accommon.h"
46 #include "acnamesp.h"
47 #include "acevents.h"
48 #include "acinterp.h"
49 
50 #define _COMPONENT          ACPI_EVENTS
51 ACPI_MODULE_NAME("evxface")
52 
53 /*******************************************************************************
54  *
55  * FUNCTION:    acpi_install_exception_handler
56  *
57  * PARAMETERS:  Handler         - Pointer to the handler function for the
58  *                                event
59  *
60  * RETURN:      Status
61  *
62  * DESCRIPTION: Saves the pointer to the handler function
63  *
64  ******************************************************************************/
65 #ifdef ACPI_FUTURE_USAGE
66 acpi_status acpi_install_exception_handler(acpi_exception_handler handler)
67 {
68 	acpi_status status;
69 
70 	ACPI_FUNCTION_TRACE(acpi_install_exception_handler);
71 
72 	status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
73 	if (ACPI_FAILURE(status)) {
74 		return_ACPI_STATUS(status);
75 	}
76 
77 	/* Don't allow two handlers. */
78 
79 	if (acpi_gbl_exception_handler) {
80 		status = AE_ALREADY_EXISTS;
81 		goto cleanup;
82 	}
83 
84 	/* Install the handler */
85 
86 	acpi_gbl_exception_handler = handler;
87 
88       cleanup:
89 	(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
90 	return_ACPI_STATUS(status);
91 }
92 
93 ACPI_EXPORT_SYMBOL(acpi_install_exception_handler)
94 #endif				/*  ACPI_FUTURE_USAGE  */
95 /*******************************************************************************
96  *
97  * FUNCTION:    acpi_install_fixed_event_handler
98  *
99  * PARAMETERS:  Event           - Event type to enable.
100  *              Handler         - Pointer to the handler function for the
101  *                                event
102  *              Context         - Value passed to the handler on each GPE
103  *
104  * RETURN:      Status
105  *
106  * DESCRIPTION: Saves the pointer to the handler function and then enables the
107  *              event.
108  *
109  ******************************************************************************/
110 acpi_status
111 acpi_install_fixed_event_handler(u32 event,
112 				 acpi_event_handler handler, void *context)
113 {
114 	acpi_status status;
115 
116 	ACPI_FUNCTION_TRACE(acpi_install_fixed_event_handler);
117 
118 	/* Parameter validation */
119 
120 	if (event > ACPI_EVENT_MAX) {
121 		return_ACPI_STATUS(AE_BAD_PARAMETER);
122 	}
123 
124 	status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
125 	if (ACPI_FAILURE(status)) {
126 		return_ACPI_STATUS(status);
127 	}
128 
129 	/* Don't allow two handlers. */
130 
131 	if (NULL != acpi_gbl_fixed_event_handlers[event].handler) {
132 		status = AE_ALREADY_EXISTS;
133 		goto cleanup;
134 	}
135 
136 	/* Install the handler before enabling the event */
137 
138 	acpi_gbl_fixed_event_handlers[event].handler = handler;
139 	acpi_gbl_fixed_event_handlers[event].context = context;
140 
141 	status = acpi_clear_event(event);
142 	if (ACPI_SUCCESS(status))
143 		status = acpi_enable_event(event, 0);
144 	if (ACPI_FAILURE(status)) {
145 		ACPI_WARNING((AE_INFO, "Could not enable fixed event %X",
146 			      event));
147 
148 		/* Remove the handler */
149 
150 		acpi_gbl_fixed_event_handlers[event].handler = NULL;
151 		acpi_gbl_fixed_event_handlers[event].context = NULL;
152 	} else {
153 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
154 				  "Enabled fixed event %X, Handler=%p\n", event,
155 				  handler));
156 	}
157 
158       cleanup:
159 	(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
160 	return_ACPI_STATUS(status);
161 }
162 
163 ACPI_EXPORT_SYMBOL(acpi_install_fixed_event_handler)
164 
165 /*******************************************************************************
166  *
167  * FUNCTION:    acpi_remove_fixed_event_handler
168  *
169  * PARAMETERS:  Event           - Event type to disable.
170  *              Handler         - Address of the handler
171  *
172  * RETURN:      Status
173  *
174  * DESCRIPTION: Disables the event and unregisters the event handler.
175  *
176  ******************************************************************************/
177 acpi_status
178 acpi_remove_fixed_event_handler(u32 event, acpi_event_handler handler)
179 {
180 	acpi_status status = AE_OK;
181 
182 	ACPI_FUNCTION_TRACE(acpi_remove_fixed_event_handler);
183 
184 	/* Parameter validation */
185 
186 	if (event > ACPI_EVENT_MAX) {
187 		return_ACPI_STATUS(AE_BAD_PARAMETER);
188 	}
189 
190 	status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
191 	if (ACPI_FAILURE(status)) {
192 		return_ACPI_STATUS(status);
193 	}
194 
195 	/* Disable the event before removing the handler */
196 
197 	status = acpi_disable_event(event, 0);
198 
199 	/* Always Remove the handler */
200 
201 	acpi_gbl_fixed_event_handlers[event].handler = NULL;
202 	acpi_gbl_fixed_event_handlers[event].context = NULL;
203 
204 	if (ACPI_FAILURE(status)) {
205 		ACPI_WARNING((AE_INFO,
206 			      "Could not write to fixed event enable register %X",
207 			      event));
208 	} else {
209 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Disabled fixed event %X\n",
210 				  event));
211 	}
212 
213 	(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
214 	return_ACPI_STATUS(status);
215 }
216 
217 ACPI_EXPORT_SYMBOL(acpi_remove_fixed_event_handler)
218 
219 /*******************************************************************************
220  *
221  * FUNCTION:    acpi_install_notify_handler
222  *
223  * PARAMETERS:  Device          - The device for which notifies will be handled
224  *              handler_type    - The type of handler:
225  *                                  ACPI_SYSTEM_NOTIFY: system_handler (00-7f)
226  *                                  ACPI_DEVICE_NOTIFY: driver_handler (80-ff)
227  *                                  ACPI_ALL_NOTIFY:  both system and device
228  *              Handler         - Address of the handler
229  *              Context         - Value passed to the handler on each GPE
230  *
231  * RETURN:      Status
232  *
233  * DESCRIPTION: Install a handler for notifies on an ACPI device
234  *
235  ******************************************************************************/
236 acpi_status
237 acpi_install_notify_handler(acpi_handle device,
238 			    u32 handler_type,
239 			    acpi_notify_handler handler, void *context)
240 {
241 	union acpi_operand_object *obj_desc;
242 	union acpi_operand_object *notify_obj;
243 	struct acpi_namespace_node *node;
244 	acpi_status status;
245 
246 	ACPI_FUNCTION_TRACE(acpi_install_notify_handler);
247 
248 	/* Parameter validation */
249 
250 	if ((!device) ||
251 	    (!handler) || (handler_type > ACPI_MAX_NOTIFY_HANDLER_TYPE)) {
252 		return_ACPI_STATUS(AE_BAD_PARAMETER);
253 	}
254 
255 	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
256 	if (ACPI_FAILURE(status)) {
257 		return_ACPI_STATUS(status);
258 	}
259 
260 	/* Convert and validate the device handle */
261 
262 	node = acpi_ns_map_handle_to_node(device);
263 	if (!node) {
264 		status = AE_BAD_PARAMETER;
265 		goto unlock_and_exit;
266 	}
267 
268 	/*
269 	 * Root Object:
270 	 * Registering a notify handler on the root object indicates that the
271 	 * caller wishes to receive notifications for all objects. Note that
272 	 * only one <external> global handler can be regsitered (per notify type).
273 	 */
274 	if (device == ACPI_ROOT_OBJECT) {
275 
276 		/* Make sure the handler is not already installed */
277 
278 		if (((handler_type & ACPI_SYSTEM_NOTIFY) &&
279 		     acpi_gbl_system_notify.handler) ||
280 		    ((handler_type & ACPI_DEVICE_NOTIFY) &&
281 		     acpi_gbl_device_notify.handler)) {
282 			status = AE_ALREADY_EXISTS;
283 			goto unlock_and_exit;
284 		}
285 
286 		if (handler_type & ACPI_SYSTEM_NOTIFY) {
287 			acpi_gbl_system_notify.node = node;
288 			acpi_gbl_system_notify.handler = handler;
289 			acpi_gbl_system_notify.context = context;
290 		}
291 
292 		if (handler_type & ACPI_DEVICE_NOTIFY) {
293 			acpi_gbl_device_notify.node = node;
294 			acpi_gbl_device_notify.handler = handler;
295 			acpi_gbl_device_notify.context = context;
296 		}
297 
298 		/* Global notify handler installed */
299 	}
300 
301 	/*
302 	 * All Other Objects:
303 	 * Caller will only receive notifications specific to the target object.
304 	 * Note that only certain object types can receive notifications.
305 	 */
306 	else {
307 		/* Notifies allowed on this object? */
308 
309 		if (!acpi_ev_is_notify_object(node)) {
310 			status = AE_TYPE;
311 			goto unlock_and_exit;
312 		}
313 
314 		/* Check for an existing internal object */
315 
316 		obj_desc = acpi_ns_get_attached_object(node);
317 		if (obj_desc) {
318 
319 			/* Object exists - make sure there's no handler */
320 
321 			if (((handler_type & ACPI_SYSTEM_NOTIFY) &&
322 			     obj_desc->common_notify.system_notify) ||
323 			    ((handler_type & ACPI_DEVICE_NOTIFY) &&
324 			     obj_desc->common_notify.device_notify)) {
325 				status = AE_ALREADY_EXISTS;
326 				goto unlock_and_exit;
327 			}
328 		} else {
329 			/* Create a new object */
330 
331 			obj_desc = acpi_ut_create_internal_object(node->type);
332 			if (!obj_desc) {
333 				status = AE_NO_MEMORY;
334 				goto unlock_and_exit;
335 			}
336 
337 			/* Attach new object to the Node */
338 
339 			status =
340 			    acpi_ns_attach_object(device, obj_desc, node->type);
341 
342 			/* Remove local reference to the object */
343 
344 			acpi_ut_remove_reference(obj_desc);
345 			if (ACPI_FAILURE(status)) {
346 				goto unlock_and_exit;
347 			}
348 		}
349 
350 		/* Install the handler */
351 
352 		notify_obj =
353 		    acpi_ut_create_internal_object(ACPI_TYPE_LOCAL_NOTIFY);
354 		if (!notify_obj) {
355 			status = AE_NO_MEMORY;
356 			goto unlock_and_exit;
357 		}
358 
359 		notify_obj->notify.node = node;
360 		notify_obj->notify.handler = handler;
361 		notify_obj->notify.context = context;
362 
363 		if (handler_type & ACPI_SYSTEM_NOTIFY) {
364 			obj_desc->common_notify.system_notify = notify_obj;
365 		}
366 
367 		if (handler_type & ACPI_DEVICE_NOTIFY) {
368 			obj_desc->common_notify.device_notify = notify_obj;
369 		}
370 
371 		if (handler_type == ACPI_ALL_NOTIFY) {
372 
373 			/* Extra ref if installed in both */
374 
375 			acpi_ut_add_reference(notify_obj);
376 		}
377 	}
378 
379       unlock_and_exit:
380 	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
381 	return_ACPI_STATUS(status);
382 }
383 
384 ACPI_EXPORT_SYMBOL(acpi_install_notify_handler)
385 
386 /*******************************************************************************
387  *
388  * FUNCTION:    acpi_remove_notify_handler
389  *
390  * PARAMETERS:  Device          - The device for which notifies will be handled
391  *              handler_type    - The type of handler:
392  *                                  ACPI_SYSTEM_NOTIFY: system_handler (00-7f)
393  *                                  ACPI_DEVICE_NOTIFY: driver_handler (80-ff)
394  *                                  ACPI_ALL_NOTIFY:  both system and device
395  *              Handler         - Address of the handler
396  *
397  * RETURN:      Status
398  *
399  * DESCRIPTION: Remove a handler for notifies on an ACPI device
400  *
401  ******************************************************************************/
402 acpi_status
403 acpi_remove_notify_handler(acpi_handle device,
404 			   u32 handler_type, acpi_notify_handler handler)
405 {
406 	union acpi_operand_object *notify_obj;
407 	union acpi_operand_object *obj_desc;
408 	struct acpi_namespace_node *node;
409 	acpi_status status;
410 
411 	ACPI_FUNCTION_TRACE(acpi_remove_notify_handler);
412 
413 	/* Parameter validation */
414 
415 	if ((!device) ||
416 	    (!handler) || (handler_type > ACPI_MAX_NOTIFY_HANDLER_TYPE)) {
417 		status = AE_BAD_PARAMETER;
418 		goto exit;
419 	}
420 
421 	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
422 	if (ACPI_FAILURE(status)) {
423 		goto exit;
424 	}
425 
426 	/* Convert and validate the device handle */
427 
428 	node = acpi_ns_map_handle_to_node(device);
429 	if (!node) {
430 		status = AE_BAD_PARAMETER;
431 		goto unlock_and_exit;
432 	}
433 
434 	/* Root Object */
435 
436 	if (device == ACPI_ROOT_OBJECT) {
437 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
438 				  "Removing notify handler for namespace root object\n"));
439 
440 		if (((handler_type & ACPI_SYSTEM_NOTIFY) &&
441 		     !acpi_gbl_system_notify.handler) ||
442 		    ((handler_type & ACPI_DEVICE_NOTIFY) &&
443 		     !acpi_gbl_device_notify.handler)) {
444 			status = AE_NOT_EXIST;
445 			goto unlock_and_exit;
446 		}
447 
448 		/* Make sure all deferred tasks are completed */
449 
450 		(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
451 		acpi_os_wait_events_complete(NULL);
452 		status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
453 		if (ACPI_FAILURE(status)) {
454 			goto exit;
455 		}
456 
457 		if (handler_type & ACPI_SYSTEM_NOTIFY) {
458 			acpi_gbl_system_notify.node = NULL;
459 			acpi_gbl_system_notify.handler = NULL;
460 			acpi_gbl_system_notify.context = NULL;
461 		}
462 
463 		if (handler_type & ACPI_DEVICE_NOTIFY) {
464 			acpi_gbl_device_notify.node = NULL;
465 			acpi_gbl_device_notify.handler = NULL;
466 			acpi_gbl_device_notify.context = NULL;
467 		}
468 	}
469 
470 	/* All Other Objects */
471 
472 	else {
473 		/* Notifies allowed on this object? */
474 
475 		if (!acpi_ev_is_notify_object(node)) {
476 			status = AE_TYPE;
477 			goto unlock_and_exit;
478 		}
479 
480 		/* Check for an existing internal object */
481 
482 		obj_desc = acpi_ns_get_attached_object(node);
483 		if (!obj_desc) {
484 			status = AE_NOT_EXIST;
485 			goto unlock_and_exit;
486 		}
487 
488 		/* Object exists - make sure there's an existing handler */
489 
490 		if (handler_type & ACPI_SYSTEM_NOTIFY) {
491 			notify_obj = obj_desc->common_notify.system_notify;
492 			if (!notify_obj) {
493 				status = AE_NOT_EXIST;
494 				goto unlock_and_exit;
495 			}
496 
497 			if (notify_obj->notify.handler != handler) {
498 				status = AE_BAD_PARAMETER;
499 				goto unlock_and_exit;
500 			}
501 			/* Make sure all deferred tasks are completed */
502 
503 			(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
504 			acpi_os_wait_events_complete(NULL);
505 			status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
506 			if (ACPI_FAILURE(status)) {
507 				goto exit;
508 			}
509 
510 			/* Remove the handler */
511 			obj_desc->common_notify.system_notify = NULL;
512 			acpi_ut_remove_reference(notify_obj);
513 		}
514 
515 		if (handler_type & ACPI_DEVICE_NOTIFY) {
516 			notify_obj = obj_desc->common_notify.device_notify;
517 			if (!notify_obj) {
518 				status = AE_NOT_EXIST;
519 				goto unlock_and_exit;
520 			}
521 
522 			if (notify_obj->notify.handler != handler) {
523 				status = AE_BAD_PARAMETER;
524 				goto unlock_and_exit;
525 			}
526 			/* Make sure all deferred tasks are completed */
527 
528 			(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
529 			acpi_os_wait_events_complete(NULL);
530 			status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
531 			if (ACPI_FAILURE(status)) {
532 				goto exit;
533 			}
534 
535 			/* Remove the handler */
536 			obj_desc->common_notify.device_notify = NULL;
537 			acpi_ut_remove_reference(notify_obj);
538 		}
539 	}
540 
541       unlock_and_exit:
542 	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
543       exit:
544 	if (ACPI_FAILURE(status))
545 		ACPI_EXCEPTION((AE_INFO, status, "Removing notify handler"));
546 	return_ACPI_STATUS(status);
547 }
548 
549 ACPI_EXPORT_SYMBOL(acpi_remove_notify_handler)
550 
551 /*******************************************************************************
552  *
553  * FUNCTION:    acpi_install_gpe_handler
554  *
555  * PARAMETERS:  gpe_device      - Namespace node for the GPE (NULL for FADT
556  *                                defined GPEs)
557  *              gpe_number      - The GPE number within the GPE block
558  *              Type            - Whether this GPE should be treated as an
559  *                                edge- or level-triggered interrupt.
560  *              Address         - Address of the handler
561  *              Context         - Value passed to the handler on each GPE
562  *
563  * RETURN:      Status
564  *
565  * DESCRIPTION: Install a handler for a General Purpose Event.
566  *
567  ******************************************************************************/
568 acpi_status
569 acpi_install_gpe_handler(acpi_handle gpe_device,
570 			 u32 gpe_number,
571 			 u32 type, acpi_event_handler address, void *context)
572 {
573 	struct acpi_gpe_event_info *gpe_event_info;
574 	struct acpi_handler_info *handler;
575 	acpi_status status;
576 	acpi_cpu_flags flags;
577 
578 	ACPI_FUNCTION_TRACE(acpi_install_gpe_handler);
579 
580 	/* Parameter validation */
581 
582 	if ((!address) || (type > ACPI_GPE_XRUPT_TYPE_MASK)) {
583 		status = AE_BAD_PARAMETER;
584 		goto exit;
585 	}
586 
587 	status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
588 	if (ACPI_FAILURE(status)) {
589 		goto exit;
590 	}
591 
592 	/* Ensure that we have a valid GPE number */
593 
594 	gpe_event_info = acpi_ev_get_gpe_event_info(gpe_device, gpe_number);
595 	if (!gpe_event_info) {
596 		status = AE_BAD_PARAMETER;
597 		goto unlock_and_exit;
598 	}
599 
600 	/* Make sure that there isn't a handler there already */
601 
602 	if ((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) ==
603 	    ACPI_GPE_DISPATCH_HANDLER) {
604 		status = AE_ALREADY_EXISTS;
605 		goto unlock_and_exit;
606 	}
607 
608 	/* Allocate and init handler object */
609 
610 	handler = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_handler_info));
611 	if (!handler) {
612 		status = AE_NO_MEMORY;
613 		goto unlock_and_exit;
614 	}
615 
616 	handler->address = address;
617 	handler->context = context;
618 	handler->method_node = gpe_event_info->dispatch.method_node;
619 
620 	/* Disable the GPE before installing the handler */
621 
622 	status = acpi_ev_disable_gpe(gpe_event_info);
623 	if (ACPI_FAILURE(status)) {
624 		goto unlock_and_exit;
625 	}
626 
627 	/* Install the handler */
628 
629 	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
630 	gpe_event_info->dispatch.handler = handler;
631 
632 	/* Setup up dispatch flags to indicate handler (vs. method) */
633 
634 	gpe_event_info->flags &=
635 	    ~(ACPI_GPE_XRUPT_TYPE_MASK | ACPI_GPE_DISPATCH_MASK);
636 	gpe_event_info->flags |= (u8) (type | ACPI_GPE_DISPATCH_HANDLER);
637 
638 	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
639 
640       unlock_and_exit:
641 	(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
642       exit:
643 	if (ACPI_FAILURE(status))
644 		ACPI_EXCEPTION((AE_INFO, status,
645 				"Installing notify handler failed"));
646 	return_ACPI_STATUS(status);
647 }
648 
649 ACPI_EXPORT_SYMBOL(acpi_install_gpe_handler)
650 
651 /*******************************************************************************
652  *
653  * FUNCTION:    acpi_remove_gpe_handler
654  *
655  * PARAMETERS:  gpe_device      - Namespace node for the GPE (NULL for FADT
656  *                                defined GPEs)
657  *              gpe_number      - The event to remove a handler
658  *              Address         - Address of the handler
659  *
660  * RETURN:      Status
661  *
662  * DESCRIPTION: Remove a handler for a General Purpose acpi_event.
663  *
664  ******************************************************************************/
665 acpi_status
666 acpi_remove_gpe_handler(acpi_handle gpe_device,
667 			u32 gpe_number, acpi_event_handler address)
668 {
669 	struct acpi_gpe_event_info *gpe_event_info;
670 	struct acpi_handler_info *handler;
671 	acpi_status status;
672 	acpi_cpu_flags flags;
673 
674 	ACPI_FUNCTION_TRACE(acpi_remove_gpe_handler);
675 
676 	/* Parameter validation */
677 
678 	if (!address) {
679 		return_ACPI_STATUS(AE_BAD_PARAMETER);
680 	}
681 
682 	status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
683 	if (ACPI_FAILURE(status)) {
684 		return_ACPI_STATUS(status);
685 	}
686 
687 	/* Ensure that we have a valid GPE number */
688 
689 	gpe_event_info = acpi_ev_get_gpe_event_info(gpe_device, gpe_number);
690 	if (!gpe_event_info) {
691 		status = AE_BAD_PARAMETER;
692 		goto unlock_and_exit;
693 	}
694 
695 	/* Make sure that a handler is indeed installed */
696 
697 	if ((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) !=
698 	    ACPI_GPE_DISPATCH_HANDLER) {
699 		status = AE_NOT_EXIST;
700 		goto unlock_and_exit;
701 	}
702 
703 	/* Make sure that the installed handler is the same */
704 
705 	if (gpe_event_info->dispatch.handler->address != address) {
706 		status = AE_BAD_PARAMETER;
707 		goto unlock_and_exit;
708 	}
709 
710 	/* Disable the GPE before removing the handler */
711 
712 	status = acpi_ev_disable_gpe(gpe_event_info);
713 	if (ACPI_FAILURE(status)) {
714 		goto unlock_and_exit;
715 	}
716 
717 	/* Make sure all deferred tasks are completed */
718 
719 	(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
720 	acpi_os_wait_events_complete(NULL);
721 	status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
722 	if (ACPI_FAILURE(status)) {
723 		return_ACPI_STATUS(status);
724 	}
725 
726 	/* Remove the handler */
727 
728 	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
729 	handler = gpe_event_info->dispatch.handler;
730 
731 	/* Restore Method node (if any), set dispatch flags */
732 
733 	gpe_event_info->dispatch.method_node = handler->method_node;
734 	gpe_event_info->flags &= ~ACPI_GPE_DISPATCH_MASK;	/* Clear bits */
735 	if (handler->method_node) {
736 		gpe_event_info->flags |= ACPI_GPE_DISPATCH_METHOD;
737 	}
738 	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
739 
740 	/* Now we can free the handler object */
741 
742 	ACPI_FREE(handler);
743 
744       unlock_and_exit:
745 	(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
746 	return_ACPI_STATUS(status);
747 }
748 
749 ACPI_EXPORT_SYMBOL(acpi_remove_gpe_handler)
750 
751 /*******************************************************************************
752  *
753  * FUNCTION:    acpi_acquire_global_lock
754  *
755  * PARAMETERS:  Timeout         - How long the caller is willing to wait
756  *              Handle          - Where the handle to the lock is returned
757  *                                (if acquired)
758  *
759  * RETURN:      Status
760  *
761  * DESCRIPTION: Acquire the ACPI Global Lock
762  *
763  * Note: Allows callers with the same thread ID to acquire the global lock
764  * multiple times. In other words, externally, the behavior of the global lock
765  * is identical to an AML mutex. On the first acquire, a new handle is
766  * returned. On any subsequent calls to acquire by the same thread, the same
767  * handle is returned.
768  *
769  ******************************************************************************/
770 acpi_status acpi_acquire_global_lock(u16 timeout, u32 * handle)
771 {
772 	acpi_status status;
773 
774 	if (!handle) {
775 		return (AE_BAD_PARAMETER);
776 	}
777 
778 	/* Must lock interpreter to prevent race conditions */
779 
780 	acpi_ex_enter_interpreter();
781 
782 	status = acpi_ex_acquire_mutex_object(timeout,
783 					      acpi_gbl_global_lock_mutex,
784 					      acpi_os_get_thread_id());
785 
786 	if (ACPI_SUCCESS(status)) {
787 
788 		/* Return the global lock handle (updated in acpi_ev_acquire_global_lock) */
789 
790 		*handle = acpi_gbl_global_lock_handle;
791 	}
792 
793 	acpi_ex_exit_interpreter();
794 	return (status);
795 }
796 
797 ACPI_EXPORT_SYMBOL(acpi_acquire_global_lock)
798 
799 /*******************************************************************************
800  *
801  * FUNCTION:    acpi_release_global_lock
802  *
803  * PARAMETERS:  Handle      - Returned from acpi_acquire_global_lock
804  *
805  * RETURN:      Status
806  *
807  * DESCRIPTION: Release the ACPI Global Lock. The handle must be valid.
808  *
809  ******************************************************************************/
810 acpi_status acpi_release_global_lock(u32 handle)
811 {
812 	acpi_status status;
813 
814 	if (!handle || (handle != acpi_gbl_global_lock_handle)) {
815 		return (AE_NOT_ACQUIRED);
816 	}
817 
818 	status = acpi_ex_release_mutex_object(acpi_gbl_global_lock_mutex);
819 	return (status);
820 }
821 
822 ACPI_EXPORT_SYMBOL(acpi_release_global_lock)
823