xref: /linux/drivers/acpi/acpica/evgpe.c (revision 2ba9268dd603d23e17643437b2246acb6844953b)
1 /******************************************************************************
2  *
3  * Module Name: evgpe - General Purpose Event handling and dispatch
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2015, 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 "acevents.h"
47 #include "acnamesp.h"
48 
49 #define _COMPONENT          ACPI_EVENTS
50 ACPI_MODULE_NAME("evgpe")
51 #if (!ACPI_REDUCED_HARDWARE)	/* Entire module */
52 /* Local prototypes */
53 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context);
54 
55 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_enable_gpe(void *context);
56 
57 /*******************************************************************************
58  *
59  * FUNCTION:    acpi_ev_update_gpe_enable_mask
60  *
61  * PARAMETERS:  gpe_event_info          - GPE to update
62  *
63  * RETURN:      Status
64  *
65  * DESCRIPTION: Updates GPE register enable mask based upon whether there are
66  *              runtime references to this GPE
67  *
68  ******************************************************************************/
69 
70 acpi_status
71 acpi_ev_update_gpe_enable_mask(struct acpi_gpe_event_info *gpe_event_info)
72 {
73 	struct acpi_gpe_register_info *gpe_register_info;
74 	u32 register_bit;
75 
76 	ACPI_FUNCTION_TRACE(ev_update_gpe_enable_mask);
77 
78 	gpe_register_info = gpe_event_info->register_info;
79 	if (!gpe_register_info) {
80 		return_ACPI_STATUS(AE_NOT_EXIST);
81 	}
82 
83 	register_bit = acpi_hw_get_gpe_register_bit(gpe_event_info);
84 
85 	/* Clear the run bit up front */
86 
87 	ACPI_CLEAR_BIT(gpe_register_info->enable_for_run, register_bit);
88 
89 	/* Set the mask bit only if there are references to this GPE */
90 
91 	if (gpe_event_info->runtime_count) {
92 		ACPI_SET_BIT(gpe_register_info->enable_for_run,
93 			     (u8)register_bit);
94 	}
95 
96 	return_ACPI_STATUS(AE_OK);
97 }
98 
99 /*******************************************************************************
100  *
101  * FUNCTION:    acpi_ev_enable_gpe
102  *
103  * PARAMETERS:  gpe_event_info          - GPE to enable
104  *
105  * RETURN:      Status
106  *
107  * DESCRIPTION: Clear a GPE of stale events and enable it.
108  *
109  ******************************************************************************/
110 
111 acpi_status acpi_ev_enable_gpe(struct acpi_gpe_event_info *gpe_event_info)
112 {
113 	acpi_status status;
114 
115 	ACPI_FUNCTION_TRACE(ev_enable_gpe);
116 
117 	/* Clear the GPE (of stale events) */
118 
119 	status = acpi_hw_clear_gpe(gpe_event_info);
120 	if (ACPI_FAILURE(status)) {
121 		return_ACPI_STATUS(status);
122 	}
123 
124 	/* Enable the requested GPE */
125 
126 	status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_ENABLE_SAVE);
127 	return_ACPI_STATUS(status);
128 }
129 
130 /*******************************************************************************
131  *
132  * FUNCTION:    acpi_ev_add_gpe_reference
133  *
134  * PARAMETERS:  gpe_event_info          - Add a reference to this GPE
135  *
136  * RETURN:      Status
137  *
138  * DESCRIPTION: Add a reference to a GPE. On the first reference, the GPE is
139  *              hardware-enabled.
140  *
141  ******************************************************************************/
142 
143 acpi_status
144 acpi_ev_add_gpe_reference(struct acpi_gpe_event_info *gpe_event_info)
145 {
146 	acpi_status status = AE_OK;
147 
148 	ACPI_FUNCTION_TRACE(ev_add_gpe_reference);
149 
150 	if (gpe_event_info->runtime_count == ACPI_UINT8_MAX) {
151 		return_ACPI_STATUS(AE_LIMIT);
152 	}
153 
154 	gpe_event_info->runtime_count++;
155 	if (gpe_event_info->runtime_count == 1) {
156 
157 		/* Enable on first reference */
158 
159 		status = acpi_ev_update_gpe_enable_mask(gpe_event_info);
160 		if (ACPI_SUCCESS(status)) {
161 			status = acpi_ev_enable_gpe(gpe_event_info);
162 		}
163 
164 		if (ACPI_FAILURE(status)) {
165 			gpe_event_info->runtime_count--;
166 		}
167 	}
168 
169 	return_ACPI_STATUS(status);
170 }
171 
172 /*******************************************************************************
173  *
174  * FUNCTION:    acpi_ev_remove_gpe_reference
175  *
176  * PARAMETERS:  gpe_event_info          - Remove a reference to this GPE
177  *
178  * RETURN:      Status
179  *
180  * DESCRIPTION: Remove a reference to a GPE. When the last reference is
181  *              removed, the GPE is hardware-disabled.
182  *
183  ******************************************************************************/
184 
185 acpi_status
186 acpi_ev_remove_gpe_reference(struct acpi_gpe_event_info *gpe_event_info)
187 {
188 	acpi_status status = AE_OK;
189 
190 	ACPI_FUNCTION_TRACE(ev_remove_gpe_reference);
191 
192 	if (!gpe_event_info->runtime_count) {
193 		return_ACPI_STATUS(AE_LIMIT);
194 	}
195 
196 	gpe_event_info->runtime_count--;
197 	if (!gpe_event_info->runtime_count) {
198 
199 		/* Disable on last reference */
200 
201 		status = acpi_ev_update_gpe_enable_mask(gpe_event_info);
202 		if (ACPI_SUCCESS(status)) {
203 			status =
204 			    acpi_hw_low_set_gpe(gpe_event_info,
205 						ACPI_GPE_DISABLE_SAVE);
206 		}
207 
208 		if (ACPI_FAILURE(status)) {
209 			gpe_event_info->runtime_count++;
210 		}
211 	}
212 
213 	return_ACPI_STATUS(status);
214 }
215 
216 /*******************************************************************************
217  *
218  * FUNCTION:    acpi_ev_low_get_gpe_info
219  *
220  * PARAMETERS:  gpe_number          - Raw GPE number
221  *              gpe_block           - A GPE info block
222  *
223  * RETURN:      A GPE event_info struct. NULL if not a valid GPE (The gpe_number
224  *              is not within the specified GPE block)
225  *
226  * DESCRIPTION: Returns the event_info struct associated with this GPE. This is
227  *              the low-level implementation of ev_get_gpe_event_info.
228  *
229  ******************************************************************************/
230 
231 struct acpi_gpe_event_info *acpi_ev_low_get_gpe_info(u32 gpe_number,
232 						     struct acpi_gpe_block_info
233 						     *gpe_block)
234 {
235 	u32 gpe_index;
236 
237 	/*
238 	 * Validate that the gpe_number is within the specified gpe_block.
239 	 * (Two steps)
240 	 */
241 	if (!gpe_block || (gpe_number < gpe_block->block_base_number)) {
242 		return (NULL);
243 	}
244 
245 	gpe_index = gpe_number - gpe_block->block_base_number;
246 	if (gpe_index >= gpe_block->gpe_count) {
247 		return (NULL);
248 	}
249 
250 	return (&gpe_block->event_info[gpe_index]);
251 }
252 
253 
254 /*******************************************************************************
255  *
256  * FUNCTION:    acpi_ev_get_gpe_event_info
257  *
258  * PARAMETERS:  gpe_device          - Device node. NULL for GPE0/GPE1
259  *              gpe_number          - Raw GPE number
260  *
261  * RETURN:      A GPE event_info struct. NULL if not a valid GPE
262  *
263  * DESCRIPTION: Returns the event_info struct associated with this GPE.
264  *              Validates the gpe_block and the gpe_number
265  *
266  *              Should be called only when the GPE lists are semaphore locked
267  *              and not subject to change.
268  *
269  ******************************************************************************/
270 
271 struct acpi_gpe_event_info *acpi_ev_get_gpe_event_info(acpi_handle gpe_device,
272 						       u32 gpe_number)
273 {
274 	union acpi_operand_object *obj_desc;
275 	struct acpi_gpe_event_info *gpe_info;
276 	u32 i;
277 
278 	ACPI_FUNCTION_ENTRY();
279 
280 	/* A NULL gpe_device means use the FADT-defined GPE block(s) */
281 
282 	if (!gpe_device) {
283 
284 		/* Examine GPE Block 0 and 1 (These blocks are permanent) */
285 
286 		for (i = 0; i < ACPI_MAX_GPE_BLOCKS; i++) {
287 			gpe_info = acpi_ev_low_get_gpe_info(gpe_number,
288 							    acpi_gbl_gpe_fadt_blocks
289 							    [i]);
290 			if (gpe_info) {
291 				return (gpe_info);
292 			}
293 		}
294 
295 		/* The gpe_number was not in the range of either FADT GPE block */
296 
297 		return (NULL);
298 	}
299 
300 	/* A Non-NULL gpe_device means this is a GPE Block Device */
301 
302 	obj_desc =
303 	    acpi_ns_get_attached_object((struct acpi_namespace_node *)
304 					       gpe_device);
305 	if (!obj_desc || !obj_desc->device.gpe_block) {
306 		return (NULL);
307 	}
308 
309 	return (acpi_ev_low_get_gpe_info
310 		(gpe_number, obj_desc->device.gpe_block));
311 }
312 
313 /*******************************************************************************
314  *
315  * FUNCTION:    acpi_ev_gpe_detect
316  *
317  * PARAMETERS:  gpe_xrupt_list      - Interrupt block for this interrupt.
318  *                                    Can have multiple GPE blocks attached.
319  *
320  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
321  *
322  * DESCRIPTION: Detect if any GP events have occurred. This function is
323  *              executed at interrupt level.
324  *
325  ******************************************************************************/
326 
327 u32 acpi_ev_gpe_detect(struct acpi_gpe_xrupt_info *gpe_xrupt_list)
328 {
329 	acpi_status status;
330 	struct acpi_gpe_block_info *gpe_block;
331 	struct acpi_namespace_node *gpe_device;
332 	struct acpi_gpe_register_info *gpe_register_info;
333 	struct acpi_gpe_event_info *gpe_event_info;
334 	u32 gpe_number;
335 	struct acpi_gpe_handler_info *gpe_handler_info;
336 	u32 int_status = ACPI_INTERRUPT_NOT_HANDLED;
337 	u8 enabled_status_byte;
338 	u32 status_reg;
339 	u32 enable_reg;
340 	acpi_cpu_flags flags;
341 	u32 i;
342 	u32 j;
343 
344 	ACPI_FUNCTION_NAME(ev_gpe_detect);
345 
346 	/* Check for the case where there are no GPEs */
347 
348 	if (!gpe_xrupt_list) {
349 		return (int_status);
350 	}
351 
352 	/*
353 	 * We need to obtain the GPE lock for both the data structs and registers
354 	 * Note: Not necessary to obtain the hardware lock, since the GPE
355 	 * registers are owned by the gpe_lock.
356 	 */
357 	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
358 
359 	/* Examine all GPE blocks attached to this interrupt level */
360 
361 	gpe_block = gpe_xrupt_list->gpe_block_list_head;
362 	while (gpe_block) {
363 		gpe_device = gpe_block->node;
364 
365 		/*
366 		 * Read all of the 8-bit GPE status and enable registers in this GPE
367 		 * block, saving all of them. Find all currently active GP events.
368 		 */
369 		for (i = 0; i < gpe_block->register_count; i++) {
370 
371 			/* Get the next status/enable pair */
372 
373 			gpe_register_info = &gpe_block->register_info[i];
374 
375 			/*
376 			 * Optimization: If there are no GPEs enabled within this
377 			 * register, we can safely ignore the entire register.
378 			 */
379 			if (!(gpe_register_info->enable_for_run |
380 			      gpe_register_info->enable_for_wake)) {
381 				ACPI_DEBUG_PRINT((ACPI_DB_INTERRUPTS,
382 						  "Ignore disabled registers for GPE %02X-%02X: "
383 						  "RunEnable=%02X, WakeEnable=%02X\n",
384 						  gpe_register_info->
385 						  base_gpe_number,
386 						  gpe_register_info->
387 						  base_gpe_number +
388 						  (ACPI_GPE_REGISTER_WIDTH - 1),
389 						  gpe_register_info->
390 						  enable_for_run,
391 						  gpe_register_info->
392 						  enable_for_wake));
393 				continue;
394 			}
395 
396 			/* Read the Status Register */
397 
398 			status =
399 			    acpi_hw_read(&status_reg,
400 					 &gpe_register_info->status_address);
401 			if (ACPI_FAILURE(status)) {
402 				goto unlock_and_exit;
403 			}
404 
405 			/* Read the Enable Register */
406 
407 			status =
408 			    acpi_hw_read(&enable_reg,
409 					 &gpe_register_info->enable_address);
410 			if (ACPI_FAILURE(status)) {
411 				goto unlock_and_exit;
412 			}
413 
414 			ACPI_DEBUG_PRINT((ACPI_DB_INTERRUPTS,
415 					  "Read registers for GPE %02X-%02X: Status=%02X, Enable=%02X, "
416 					  "RunEnable=%02X, WakeEnable=%02X\n",
417 					  gpe_register_info->base_gpe_number,
418 					  gpe_register_info->base_gpe_number +
419 					  (ACPI_GPE_REGISTER_WIDTH - 1),
420 					  status_reg, enable_reg,
421 					  gpe_register_info->enable_for_run,
422 					  gpe_register_info->enable_for_wake));
423 
424 			/* Check if there is anything active at all in this register */
425 
426 			enabled_status_byte = (u8)(status_reg & enable_reg);
427 			if (!enabled_status_byte) {
428 
429 				/* No active GPEs in this register, move on */
430 
431 				continue;
432 			}
433 
434 			/* Now look at the individual GPEs in this byte register */
435 
436 			for (j = 0; j < ACPI_GPE_REGISTER_WIDTH; j++) {
437 
438 				/* Examine one GPE bit */
439 
440 				gpe_event_info =
441 				    &gpe_block->
442 				    event_info[((acpi_size) i *
443 						ACPI_GPE_REGISTER_WIDTH) + j];
444 				gpe_number =
445 				    j + gpe_register_info->base_gpe_number;
446 
447 				if (enabled_status_byte & (1 << j)) {
448 
449 					/* Invoke global event handler if present */
450 
451 					acpi_gpe_count++;
452 					if (acpi_gbl_global_event_handler) {
453 						acpi_gbl_global_event_handler
454 						    (ACPI_EVENT_TYPE_GPE,
455 						     gpe_device, gpe_number,
456 						     acpi_gbl_global_event_handler_context);
457 					}
458 
459 					/* Found an active GPE */
460 
461 					if (ACPI_GPE_DISPATCH_TYPE
462 					    (gpe_event_info->flags) ==
463 					    ACPI_GPE_DISPATCH_RAW_HANDLER) {
464 
465 						/* Dispatch the event to a raw handler */
466 
467 						gpe_handler_info =
468 						    gpe_event_info->dispatch.
469 						    handler;
470 
471 						/*
472 						 * There is no protection around the namespace node
473 						 * and the GPE handler to ensure a safe destruction
474 						 * because:
475 						 * 1. The namespace node is expected to always
476 						 *    exist after loading a table.
477 						 * 2. The GPE handler is expected to be flushed by
478 						 *    acpi_os_wait_events_complete() before the
479 						 *    destruction.
480 						 */
481 						acpi_os_release_lock
482 						    (acpi_gbl_gpe_lock, flags);
483 						int_status |=
484 						    gpe_handler_info->
485 						    address(gpe_device,
486 							    gpe_number,
487 							    gpe_handler_info->
488 							    context);
489 						flags =
490 						    acpi_os_acquire_lock
491 						    (acpi_gbl_gpe_lock);
492 					} else {
493 						/*
494 						 * Dispatch the event to a standard handler or
495 						 * method.
496 						 */
497 						int_status |=
498 						    acpi_ev_gpe_dispatch
499 						    (gpe_device, gpe_event_info,
500 						     gpe_number);
501 					}
502 				}
503 			}
504 		}
505 
506 		gpe_block = gpe_block->next;
507 	}
508 
509 unlock_and_exit:
510 
511 	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
512 	return (int_status);
513 }
514 
515 /*******************************************************************************
516  *
517  * FUNCTION:    acpi_ev_asynch_execute_gpe_method
518  *
519  * PARAMETERS:  Context (gpe_event_info) - Info for this GPE
520  *
521  * RETURN:      None
522  *
523  * DESCRIPTION: Perform the actual execution of a GPE control method. This
524  *              function is called from an invocation of acpi_os_execute and
525  *              therefore does NOT execute at interrupt level - so that
526  *              the control method itself is not executed in the context of
527  *              an interrupt handler.
528  *
529  ******************************************************************************/
530 
531 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
532 {
533 	struct acpi_gpe_event_info *gpe_event_info = context;
534 	acpi_status status = AE_OK;
535 	struct acpi_evaluate_info *info;
536 	struct acpi_gpe_notify_info *notify;
537 
538 	ACPI_FUNCTION_TRACE(ev_asynch_execute_gpe_method);
539 
540 	/* Do the correct dispatch - normal method or implicit notify */
541 
542 	switch (ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags)) {
543 	case ACPI_GPE_DISPATCH_NOTIFY:
544 		/*
545 		 * Implicit notify.
546 		 * Dispatch a DEVICE_WAKE notify to the appropriate handler.
547 		 * NOTE: the request is queued for execution after this method
548 		 * completes. The notify handlers are NOT invoked synchronously
549 		 * from this thread -- because handlers may in turn run other
550 		 * control methods.
551 		 *
552 		 * June 2012: Expand implicit notify mechanism to support
553 		 * notifies on multiple device objects.
554 		 */
555 		notify = gpe_event_info->dispatch.notify_list;
556 		while (ACPI_SUCCESS(status) && notify) {
557 			status =
558 			    acpi_ev_queue_notify_request(notify->device_node,
559 							 ACPI_NOTIFY_DEVICE_WAKE);
560 
561 			notify = notify->next;
562 		}
563 
564 		break;
565 
566 	case ACPI_GPE_DISPATCH_METHOD:
567 
568 		/* Allocate the evaluation information block */
569 
570 		info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
571 		if (!info) {
572 			status = AE_NO_MEMORY;
573 		} else {
574 			/*
575 			 * Invoke the GPE Method (_Lxx, _Exx) i.e., evaluate the
576 			 * _Lxx/_Exx control method that corresponds to this GPE
577 			 */
578 			info->prefix_node =
579 			    gpe_event_info->dispatch.method_node;
580 			info->flags = ACPI_IGNORE_RETURN_VALUE;
581 
582 			status = acpi_ns_evaluate(info);
583 			ACPI_FREE(info);
584 		}
585 
586 		if (ACPI_FAILURE(status)) {
587 			ACPI_EXCEPTION((AE_INFO, status,
588 					"while evaluating GPE method [%4.4s]",
589 					acpi_ut_get_node_name(gpe_event_info->
590 							      dispatch.
591 							      method_node)));
592 		}
593 		break;
594 
595 	default:
596 
597 		goto error_exit;	/* Should never happen */
598 	}
599 
600 	/* Defer enabling of GPE until all notify handlers are done */
601 
602 	status = acpi_os_execute(OSL_NOTIFY_HANDLER,
603 				 acpi_ev_asynch_enable_gpe, gpe_event_info);
604 	if (ACPI_SUCCESS(status)) {
605 		return_VOID;
606 	}
607 
608 error_exit:
609 	acpi_ev_asynch_enable_gpe(gpe_event_info);
610 	return_VOID;
611 }
612 
613 
614 /*******************************************************************************
615  *
616  * FUNCTION:    acpi_ev_asynch_enable_gpe
617  *
618  * PARAMETERS:  Context (gpe_event_info) - Info for this GPE
619  *              Callback from acpi_os_execute
620  *
621  * RETURN:      None
622  *
623  * DESCRIPTION: Asynchronous clear/enable for GPE. This allows the GPE to
624  *              complete (i.e., finish execution of Notify)
625  *
626  ******************************************************************************/
627 
628 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_enable_gpe(void *context)
629 {
630 	struct acpi_gpe_event_info *gpe_event_info = context;
631 	acpi_cpu_flags flags;
632 
633 	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
634 	(void)acpi_ev_finish_gpe(gpe_event_info);
635 	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
636 
637 	return;
638 }
639 
640 
641 /*******************************************************************************
642  *
643  * FUNCTION:    acpi_ev_finish_gpe
644  *
645  * PARAMETERS:  gpe_event_info      - Info for this GPE
646  *
647  * RETURN:      Status
648  *
649  * DESCRIPTION: Clear/Enable a GPE. Common code that is used after execution
650  *              of a GPE method or a synchronous or asynchronous GPE handler.
651  *
652  ******************************************************************************/
653 
654 acpi_status acpi_ev_finish_gpe(struct acpi_gpe_event_info * gpe_event_info)
655 {
656 	acpi_status status;
657 
658 	if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
659 	    ACPI_GPE_LEVEL_TRIGGERED) {
660 		/*
661 		 * GPE is level-triggered, we clear the GPE status bit after
662 		 * handling the event.
663 		 */
664 		status = acpi_hw_clear_gpe(gpe_event_info);
665 		if (ACPI_FAILURE(status)) {
666 			return (status);
667 		}
668 	}
669 
670 	/*
671 	 * Enable this GPE, conditionally. This means that the GPE will
672 	 * only be physically enabled if the enable_mask bit is set
673 	 * in the event_info.
674 	 */
675 	(void)acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_CONDITIONAL_ENABLE);
676 	return (AE_OK);
677 }
678 
679 
680 /*******************************************************************************
681  *
682  * FUNCTION:    acpi_ev_gpe_dispatch
683  *
684  * PARAMETERS:  gpe_device          - Device node. NULL for GPE0/GPE1
685  *              gpe_event_info      - Info for this GPE
686  *              gpe_number          - Number relative to the parent GPE block
687  *
688  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
689  *
690  * DESCRIPTION: Dispatch a General Purpose Event to either a function (e.g. EC)
691  *              or method (e.g. _Lxx/_Exx) handler.
692  *
693  *              This function executes at interrupt level.
694  *
695  ******************************************************************************/
696 
697 u32
698 acpi_ev_gpe_dispatch(struct acpi_namespace_node *gpe_device,
699 		     struct acpi_gpe_event_info *gpe_event_info, u32 gpe_number)
700 {
701 	acpi_status status;
702 	u32 return_value;
703 
704 	ACPI_FUNCTION_TRACE(ev_gpe_dispatch);
705 
706 	/*
707 	 * Always disable the GPE so that it does not keep firing before
708 	 * any asynchronous activity completes (either from the execution
709 	 * of a GPE method or an asynchronous GPE handler.)
710 	 *
711 	 * If there is no handler or method to run, just disable the
712 	 * GPE and leave it disabled permanently to prevent further such
713 	 * pointless events from firing.
714 	 */
715 	status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
716 	if (ACPI_FAILURE(status)) {
717 		ACPI_EXCEPTION((AE_INFO, status,
718 				"Unable to disable GPE %02X", gpe_number));
719 		return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
720 	}
721 
722 	/*
723 	 * If edge-triggered, clear the GPE status bit now. Note that
724 	 * level-triggered events are cleared after the GPE is serviced.
725 	 */
726 	if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
727 	    ACPI_GPE_EDGE_TRIGGERED) {
728 		status = acpi_hw_clear_gpe(gpe_event_info);
729 		if (ACPI_FAILURE(status)) {
730 			ACPI_EXCEPTION((AE_INFO, status,
731 					"Unable to clear GPE %02X",
732 					gpe_number));
733 			(void)acpi_hw_low_set_gpe(gpe_event_info,
734 						  ACPI_GPE_CONDITIONAL_ENABLE);
735 			return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
736 		}
737 	}
738 
739 	/*
740 	 * Dispatch the GPE to either an installed handler or the control
741 	 * method associated with this GPE (_Lxx or _Exx). If a handler
742 	 * exists, we invoke it and do not attempt to run the method.
743 	 * If there is neither a handler nor a method, leave the GPE
744 	 * disabled.
745 	 */
746 	switch (ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags)) {
747 	case ACPI_GPE_DISPATCH_HANDLER:
748 
749 		/* Invoke the installed handler (at interrupt level) */
750 
751 		return_value =
752 		    gpe_event_info->dispatch.handler->address(gpe_device,
753 							      gpe_number,
754 							      gpe_event_info->
755 							      dispatch.handler->
756 							      context);
757 
758 		/* If requested, clear (if level-triggered) and reenable the GPE */
759 
760 		if (return_value & ACPI_REENABLE_GPE) {
761 			(void)acpi_ev_finish_gpe(gpe_event_info);
762 		}
763 		break;
764 
765 	case ACPI_GPE_DISPATCH_METHOD:
766 	case ACPI_GPE_DISPATCH_NOTIFY:
767 		/*
768 		 * Execute the method associated with the GPE
769 		 * NOTE: Level-triggered GPEs are cleared after the method completes.
770 		 */
771 		status = acpi_os_execute(OSL_GPE_HANDLER,
772 					 acpi_ev_asynch_execute_gpe_method,
773 					 gpe_event_info);
774 		if (ACPI_FAILURE(status)) {
775 			ACPI_EXCEPTION((AE_INFO, status,
776 					"Unable to queue handler for GPE %02X - event disabled",
777 					gpe_number));
778 		}
779 		break;
780 
781 	default:
782 		/*
783 		 * No handler or method to run!
784 		 * 03/2010: This case should no longer be possible. We will not allow
785 		 * a GPE to be enabled if it has no handler or method.
786 		 */
787 		ACPI_ERROR((AE_INFO,
788 			    "No handler or method for GPE %02X, disabling event",
789 			    gpe_number));
790 
791 		break;
792 	}
793 
794 	return_UINT32(ACPI_INTERRUPT_HANDLED);
795 }
796 
797 #endif				/* !ACPI_REDUCED_HARDWARE */
798