xref: /linux/drivers/acpi/acpica/evgpe.c (revision c0e297dc61f8d4453e07afbea1fa8d0e67cd4a34)
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 	gpe_register_info->enable_mask = gpe_register_info->enable_for_run;
96 
97 	return_ACPI_STATUS(AE_OK);
98 }
99 
100 /*******************************************************************************
101  *
102  * FUNCTION:    acpi_ev_enable_gpe
103  *
104  * PARAMETERS:  gpe_event_info          - GPE to enable
105  *
106  * RETURN:      Status
107  *
108  * DESCRIPTION: Clear a GPE of stale events and enable it.
109  *
110  ******************************************************************************/
111 
112 acpi_status acpi_ev_enable_gpe(struct acpi_gpe_event_info *gpe_event_info)
113 {
114 	acpi_status status;
115 
116 	ACPI_FUNCTION_TRACE(ev_enable_gpe);
117 
118 	/* Clear the GPE (of stale events) */
119 
120 	status = acpi_hw_clear_gpe(gpe_event_info);
121 	if (ACPI_FAILURE(status)) {
122 		return_ACPI_STATUS(status);
123 	}
124 
125 	/* Enable the requested GPE */
126 
127 	status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_ENABLE);
128 	return_ACPI_STATUS(status);
129 }
130 
131 /*******************************************************************************
132  *
133  * FUNCTION:    acpi_ev_add_gpe_reference
134  *
135  * PARAMETERS:  gpe_event_info          - Add a reference to this GPE
136  *
137  * RETURN:      Status
138  *
139  * DESCRIPTION: Add a reference to a GPE. On the first reference, the GPE is
140  *              hardware-enabled.
141  *
142  ******************************************************************************/
143 
144 acpi_status
145 acpi_ev_add_gpe_reference(struct acpi_gpe_event_info *gpe_event_info)
146 {
147 	acpi_status status = AE_OK;
148 
149 	ACPI_FUNCTION_TRACE(ev_add_gpe_reference);
150 
151 	if (gpe_event_info->runtime_count == ACPI_UINT8_MAX) {
152 		return_ACPI_STATUS(AE_LIMIT);
153 	}
154 
155 	gpe_event_info->runtime_count++;
156 	if (gpe_event_info->runtime_count == 1) {
157 
158 		/* Enable on first reference */
159 
160 		status = acpi_ev_update_gpe_enable_mask(gpe_event_info);
161 		if (ACPI_SUCCESS(status)) {
162 			status = acpi_ev_enable_gpe(gpe_event_info);
163 		}
164 
165 		if (ACPI_FAILURE(status)) {
166 			gpe_event_info->runtime_count--;
167 		}
168 	}
169 
170 	return_ACPI_STATUS(status);
171 }
172 
173 /*******************************************************************************
174  *
175  * FUNCTION:    acpi_ev_remove_gpe_reference
176  *
177  * PARAMETERS:  gpe_event_info          - Remove a reference to this GPE
178  *
179  * RETURN:      Status
180  *
181  * DESCRIPTION: Remove a reference to a GPE. When the last reference is
182  *              removed, the GPE is hardware-disabled.
183  *
184  ******************************************************************************/
185 
186 acpi_status
187 acpi_ev_remove_gpe_reference(struct acpi_gpe_event_info *gpe_event_info)
188 {
189 	acpi_status status = AE_OK;
190 
191 	ACPI_FUNCTION_TRACE(ev_remove_gpe_reference);
192 
193 	if (!gpe_event_info->runtime_count) {
194 		return_ACPI_STATUS(AE_LIMIT);
195 	}
196 
197 	gpe_event_info->runtime_count--;
198 	if (!gpe_event_info->runtime_count) {
199 
200 		/* Disable on last reference */
201 
202 		status = acpi_ev_update_gpe_enable_mask(gpe_event_info);
203 		if (ACPI_SUCCESS(status)) {
204 			status =
205 			    acpi_hw_low_set_gpe(gpe_event_info,
206 						ACPI_GPE_DISABLE);
207 		}
208 
209 		if (ACPI_FAILURE(status)) {
210 			gpe_event_info->runtime_count++;
211 		}
212 	}
213 
214 	return_ACPI_STATUS(status);
215 }
216 
217 /*******************************************************************************
218  *
219  * FUNCTION:    acpi_ev_low_get_gpe_info
220  *
221  * PARAMETERS:  gpe_number          - Raw GPE number
222  *              gpe_block           - A GPE info block
223  *
224  * RETURN:      A GPE event_info struct. NULL if not a valid GPE (The gpe_number
225  *              is not within the specified GPE block)
226  *
227  * DESCRIPTION: Returns the event_info struct associated with this GPE. This is
228  *              the low-level implementation of ev_get_gpe_event_info.
229  *
230  ******************************************************************************/
231 
232 struct acpi_gpe_event_info *acpi_ev_low_get_gpe_info(u32 gpe_number,
233 						     struct acpi_gpe_block_info
234 						     *gpe_block)
235 {
236 	u32 gpe_index;
237 
238 	/*
239 	 * Validate that the gpe_number is within the specified gpe_block.
240 	 * (Two steps)
241 	 */
242 	if (!gpe_block || (gpe_number < gpe_block->block_base_number)) {
243 		return (NULL);
244 	}
245 
246 	gpe_index = gpe_number - gpe_block->block_base_number;
247 	if (gpe_index >= gpe_block->gpe_count) {
248 		return (NULL);
249 	}
250 
251 	return (&gpe_block->event_info[gpe_index]);
252 }
253 
254 
255 /*******************************************************************************
256  *
257  * FUNCTION:    acpi_ev_get_gpe_event_info
258  *
259  * PARAMETERS:  gpe_device          - Device node. NULL for GPE0/GPE1
260  *              gpe_number          - Raw GPE number
261  *
262  * RETURN:      A GPE event_info struct. NULL if not a valid GPE
263  *
264  * DESCRIPTION: Returns the event_info struct associated with this GPE.
265  *              Validates the gpe_block and the gpe_number
266  *
267  *              Should be called only when the GPE lists are semaphore locked
268  *              and not subject to change.
269  *
270  ******************************************************************************/
271 
272 struct acpi_gpe_event_info *acpi_ev_get_gpe_event_info(acpi_handle gpe_device,
273 						       u32 gpe_number)
274 {
275 	union acpi_operand_object *obj_desc;
276 	struct acpi_gpe_event_info *gpe_info;
277 	u32 i;
278 
279 	ACPI_FUNCTION_ENTRY();
280 
281 	/* A NULL gpe_device means use the FADT-defined GPE block(s) */
282 
283 	if (!gpe_device) {
284 
285 		/* Examine GPE Block 0 and 1 (These blocks are permanent) */
286 
287 		for (i = 0; i < ACPI_MAX_GPE_BLOCKS; i++) {
288 			gpe_info = acpi_ev_low_get_gpe_info(gpe_number,
289 							    acpi_gbl_gpe_fadt_blocks
290 							    [i]);
291 			if (gpe_info) {
292 				return (gpe_info);
293 			}
294 		}
295 
296 		/* The gpe_number was not in the range of either FADT GPE block */
297 
298 		return (NULL);
299 	}
300 
301 	/* A Non-NULL gpe_device means this is a GPE Block Device */
302 
303 	obj_desc =
304 	    acpi_ns_get_attached_object((struct acpi_namespace_node *)
305 					       gpe_device);
306 	if (!obj_desc || !obj_desc->device.gpe_block) {
307 		return (NULL);
308 	}
309 
310 	return (acpi_ev_low_get_gpe_info
311 		(gpe_number, obj_desc->device.gpe_block));
312 }
313 
314 /*******************************************************************************
315  *
316  * FUNCTION:    acpi_ev_gpe_detect
317  *
318  * PARAMETERS:  gpe_xrupt_list      - Interrupt block for this interrupt.
319  *                                    Can have multiple GPE blocks attached.
320  *
321  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
322  *
323  * DESCRIPTION: Detect if any GP events have occurred. This function is
324  *              executed at interrupt level.
325  *
326  ******************************************************************************/
327 
328 u32 acpi_ev_gpe_detect(struct acpi_gpe_xrupt_info *gpe_xrupt_list)
329 {
330 	acpi_status status;
331 	struct acpi_gpe_block_info *gpe_block;
332 	struct acpi_namespace_node *gpe_device;
333 	struct acpi_gpe_register_info *gpe_register_info;
334 	struct acpi_gpe_event_info *gpe_event_info;
335 	u32 gpe_number;
336 	struct acpi_gpe_handler_info *gpe_handler_info;
337 	u32 int_status = ACPI_INTERRUPT_NOT_HANDLED;
338 	u8 enabled_status_byte;
339 	u32 status_reg;
340 	u32 enable_reg;
341 	acpi_cpu_flags flags;
342 	u32 i;
343 	u32 j;
344 
345 	ACPI_FUNCTION_NAME(ev_gpe_detect);
346 
347 	/* Check for the case where there are no GPEs */
348 
349 	if (!gpe_xrupt_list) {
350 		return (int_status);
351 	}
352 
353 	/*
354 	 * We need to obtain the GPE lock for both the data structs and registers
355 	 * Note: Not necessary to obtain the hardware lock, since the GPE
356 	 * registers are owned by the gpe_lock.
357 	 */
358 	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
359 
360 	/* Examine all GPE blocks attached to this interrupt level */
361 
362 	gpe_block = gpe_xrupt_list->gpe_block_list_head;
363 	while (gpe_block) {
364 		gpe_device = gpe_block->node;
365 
366 		/*
367 		 * Read all of the 8-bit GPE status and enable registers in this GPE
368 		 * block, saving all of them. Find all currently active GP events.
369 		 */
370 		for (i = 0; i < gpe_block->register_count; i++) {
371 
372 			/* Get the next status/enable pair */
373 
374 			gpe_register_info = &gpe_block->register_info[i];
375 
376 			/*
377 			 * Optimization: If there are no GPEs enabled within this
378 			 * register, we can safely ignore the entire register.
379 			 */
380 			if (!(gpe_register_info->enable_for_run |
381 			      gpe_register_info->enable_for_wake)) {
382 				ACPI_DEBUG_PRINT((ACPI_DB_INTERRUPTS,
383 						  "Ignore disabled registers for GPE %02X-%02X: "
384 						  "RunEnable=%02X, WakeEnable=%02X\n",
385 						  gpe_register_info->
386 						  base_gpe_number,
387 						  gpe_register_info->
388 						  base_gpe_number +
389 						  (ACPI_GPE_REGISTER_WIDTH - 1),
390 						  gpe_register_info->
391 						  enable_for_run,
392 						  gpe_register_info->
393 						  enable_for_wake));
394 				continue;
395 			}
396 
397 			/* Read the Status Register */
398 
399 			status =
400 			    acpi_hw_read(&status_reg,
401 					 &gpe_register_info->status_address);
402 			if (ACPI_FAILURE(status)) {
403 				goto unlock_and_exit;
404 			}
405 
406 			/* Read the Enable Register */
407 
408 			status =
409 			    acpi_hw_read(&enable_reg,
410 					 &gpe_register_info->enable_address);
411 			if (ACPI_FAILURE(status)) {
412 				goto unlock_and_exit;
413 			}
414 
415 			ACPI_DEBUG_PRINT((ACPI_DB_INTERRUPTS,
416 					  "Read registers for GPE %02X-%02X: Status=%02X, Enable=%02X, "
417 					  "RunEnable=%02X, WakeEnable=%02X\n",
418 					  gpe_register_info->base_gpe_number,
419 					  gpe_register_info->base_gpe_number +
420 					  (ACPI_GPE_REGISTER_WIDTH - 1),
421 					  status_reg, enable_reg,
422 					  gpe_register_info->enable_for_run,
423 					  gpe_register_info->enable_for_wake));
424 
425 			/* Check if there is anything active at all in this register */
426 
427 			enabled_status_byte = (u8)(status_reg & enable_reg);
428 			if (!enabled_status_byte) {
429 
430 				/* No active GPEs in this register, move on */
431 
432 				continue;
433 			}
434 
435 			/* Now look at the individual GPEs in this byte register */
436 
437 			for (j = 0; j < ACPI_GPE_REGISTER_WIDTH; j++) {
438 
439 				/* Examine one GPE bit */
440 
441 				gpe_event_info =
442 				    &gpe_block->
443 				    event_info[((acpi_size) i *
444 						ACPI_GPE_REGISTER_WIDTH) + j];
445 				gpe_number =
446 				    j + gpe_register_info->base_gpe_number;
447 
448 				if (enabled_status_byte & (1 << j)) {
449 
450 					/* Invoke global event handler if present */
451 
452 					acpi_gpe_count++;
453 					if (acpi_gbl_global_event_handler) {
454 						acpi_gbl_global_event_handler
455 						    (ACPI_EVENT_TYPE_GPE,
456 						     gpe_device, gpe_number,
457 						     acpi_gbl_global_event_handler_context);
458 					}
459 
460 					/* Found an active GPE */
461 
462 					if (ACPI_GPE_DISPATCH_TYPE
463 					    (gpe_event_info->flags) ==
464 					    ACPI_GPE_DISPATCH_RAW_HANDLER) {
465 
466 						/* Dispatch the event to a raw handler */
467 
468 						gpe_handler_info =
469 						    gpe_event_info->dispatch.
470 						    handler;
471 
472 						/*
473 						 * There is no protection around the namespace node
474 						 * and the GPE handler to ensure a safe destruction
475 						 * because:
476 						 * 1. The namespace node is expected to always
477 						 *    exist after loading a table.
478 						 * 2. The GPE handler is expected to be flushed by
479 						 *    acpi_os_wait_events_complete() before the
480 						 *    destruction.
481 						 */
482 						acpi_os_release_lock
483 						    (acpi_gbl_gpe_lock, flags);
484 						int_status |=
485 						    gpe_handler_info->
486 						    address(gpe_device,
487 							    gpe_number,
488 							    gpe_handler_info->
489 							    context);
490 						flags =
491 						    acpi_os_acquire_lock
492 						    (acpi_gbl_gpe_lock);
493 					} else {
494 						/*
495 						 * Dispatch the event to a standard handler or
496 						 * method.
497 						 */
498 						int_status |=
499 						    acpi_ev_gpe_dispatch
500 						    (gpe_device, gpe_event_info,
501 						     gpe_number);
502 					}
503 				}
504 			}
505 		}
506 
507 		gpe_block = gpe_block->next;
508 	}
509 
510 unlock_and_exit:
511 
512 	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
513 	return (int_status);
514 }
515 
516 /*******************************************************************************
517  *
518  * FUNCTION:    acpi_ev_asynch_execute_gpe_method
519  *
520  * PARAMETERS:  Context (gpe_event_info) - Info for this GPE
521  *
522  * RETURN:      None
523  *
524  * DESCRIPTION: Perform the actual execution of a GPE control method. This
525  *              function is called from an invocation of acpi_os_execute and
526  *              therefore does NOT execute at interrupt level - so that
527  *              the control method itself is not executed in the context of
528  *              an interrupt handler.
529  *
530  ******************************************************************************/
531 
532 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
533 {
534 	struct acpi_gpe_event_info *gpe_event_info = context;
535 	acpi_status status = AE_OK;
536 	struct acpi_evaluate_info *info;
537 	struct acpi_gpe_notify_info *notify;
538 
539 	ACPI_FUNCTION_TRACE(ev_asynch_execute_gpe_method);
540 
541 	/* Do the correct dispatch - normal method or implicit notify */
542 
543 	switch (ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags)) {
544 	case ACPI_GPE_DISPATCH_NOTIFY:
545 		/*
546 		 * Implicit notify.
547 		 * Dispatch a DEVICE_WAKE notify to the appropriate handler.
548 		 * NOTE: the request is queued for execution after this method
549 		 * completes. The notify handlers are NOT invoked synchronously
550 		 * from this thread -- because handlers may in turn run other
551 		 * control methods.
552 		 *
553 		 * June 2012: Expand implicit notify mechanism to support
554 		 * notifies on multiple device objects.
555 		 */
556 		notify = gpe_event_info->dispatch.notify_list;
557 		while (ACPI_SUCCESS(status) && notify) {
558 			status =
559 			    acpi_ev_queue_notify_request(notify->device_node,
560 							 ACPI_NOTIFY_DEVICE_WAKE);
561 
562 			notify = notify->next;
563 		}
564 
565 		break;
566 
567 	case ACPI_GPE_DISPATCH_METHOD:
568 
569 		/* Allocate the evaluation information block */
570 
571 		info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
572 		if (!info) {
573 			status = AE_NO_MEMORY;
574 		} else {
575 			/*
576 			 * Invoke the GPE Method (_Lxx, _Exx) i.e., evaluate the
577 			 * _Lxx/_Exx control method that corresponds to this GPE
578 			 */
579 			info->prefix_node =
580 			    gpe_event_info->dispatch.method_node;
581 			info->flags = ACPI_IGNORE_RETURN_VALUE;
582 
583 			status = acpi_ns_evaluate(info);
584 			ACPI_FREE(info);
585 		}
586 
587 		if (ACPI_FAILURE(status)) {
588 			ACPI_EXCEPTION((AE_INFO, status,
589 					"while evaluating GPE method [%4.4s]",
590 					acpi_ut_get_node_name(gpe_event_info->
591 							      dispatch.
592 							      method_node)));
593 		}
594 		break;
595 
596 	default:
597 
598 		goto error_exit;	/* Should never happen */
599 	}
600 
601 	/* Defer enabling of GPE until all notify handlers are done */
602 
603 	status = acpi_os_execute(OSL_NOTIFY_HANDLER,
604 				 acpi_ev_asynch_enable_gpe, gpe_event_info);
605 	if (ACPI_SUCCESS(status)) {
606 		return_VOID;
607 	}
608 
609 error_exit:
610 	acpi_ev_asynch_enable_gpe(gpe_event_info);
611 	return_VOID;
612 }
613 
614 
615 /*******************************************************************************
616  *
617  * FUNCTION:    acpi_ev_asynch_enable_gpe
618  *
619  * PARAMETERS:  Context (gpe_event_info) - Info for this GPE
620  *              Callback from acpi_os_execute
621  *
622  * RETURN:      None
623  *
624  * DESCRIPTION: Asynchronous clear/enable for GPE. This allows the GPE to
625  *              complete (i.e., finish execution of Notify)
626  *
627  ******************************************************************************/
628 
629 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_enable_gpe(void *context)
630 {
631 	struct acpi_gpe_event_info *gpe_event_info = context;
632 	acpi_cpu_flags flags;
633 
634 	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
635 	(void)acpi_ev_finish_gpe(gpe_event_info);
636 	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
637 
638 	return;
639 }
640 
641 
642 /*******************************************************************************
643  *
644  * FUNCTION:    acpi_ev_finish_gpe
645  *
646  * PARAMETERS:  gpe_event_info      - Info for this GPE
647  *
648  * RETURN:      Status
649  *
650  * DESCRIPTION: Clear/Enable a GPE. Common code that is used after execution
651  *              of a GPE method or a synchronous or asynchronous GPE handler.
652  *
653  ******************************************************************************/
654 
655 acpi_status acpi_ev_finish_gpe(struct acpi_gpe_event_info * gpe_event_info)
656 {
657 	acpi_status status;
658 
659 	if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
660 	    ACPI_GPE_LEVEL_TRIGGERED) {
661 		/*
662 		 * GPE is level-triggered, we clear the GPE status bit after
663 		 * handling the event.
664 		 */
665 		status = acpi_hw_clear_gpe(gpe_event_info);
666 		if (ACPI_FAILURE(status)) {
667 			return (status);
668 		}
669 	}
670 
671 	/*
672 	 * Enable this GPE, conditionally. This means that the GPE will
673 	 * only be physically enabled if the enable_mask bit is set
674 	 * in the event_info.
675 	 */
676 	(void)acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_CONDITIONAL_ENABLE);
677 	return (AE_OK);
678 }
679 
680 
681 /*******************************************************************************
682  *
683  * FUNCTION:    acpi_ev_gpe_dispatch
684  *
685  * PARAMETERS:  gpe_device          - Device node. NULL for GPE0/GPE1
686  *              gpe_event_info      - Info for this GPE
687  *              gpe_number          - Number relative to the parent GPE block
688  *
689  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
690  *
691  * DESCRIPTION: Dispatch a General Purpose Event to either a function (e.g. EC)
692  *              or method (e.g. _Lxx/_Exx) handler.
693  *
694  *              This function executes at interrupt level.
695  *
696  ******************************************************************************/
697 
698 u32
699 acpi_ev_gpe_dispatch(struct acpi_namespace_node *gpe_device,
700 		     struct acpi_gpe_event_info *gpe_event_info, u32 gpe_number)
701 {
702 	acpi_status status;
703 	u32 return_value;
704 
705 	ACPI_FUNCTION_TRACE(ev_gpe_dispatch);
706 
707 	/*
708 	 * Always disable the GPE so that it does not keep firing before
709 	 * any asynchronous activity completes (either from the execution
710 	 * of a GPE method or an asynchronous GPE handler.)
711 	 *
712 	 * If there is no handler or method to run, just disable the
713 	 * GPE and leave it disabled permanently to prevent further such
714 	 * pointless events from firing.
715 	 */
716 	status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
717 	if (ACPI_FAILURE(status)) {
718 		ACPI_EXCEPTION((AE_INFO, status,
719 				"Unable to disable GPE %02X", gpe_number));
720 		return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
721 	}
722 
723 	/*
724 	 * If edge-triggered, clear the GPE status bit now. Note that
725 	 * level-triggered events are cleared after the GPE is serviced.
726 	 */
727 	if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
728 	    ACPI_GPE_EDGE_TRIGGERED) {
729 		status = acpi_hw_clear_gpe(gpe_event_info);
730 		if (ACPI_FAILURE(status)) {
731 			ACPI_EXCEPTION((AE_INFO, status,
732 					"Unable to clear GPE %02X",
733 					gpe_number));
734 			(void)acpi_hw_low_set_gpe(gpe_event_info,
735 						  ACPI_GPE_CONDITIONAL_ENABLE);
736 			return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
737 		}
738 	}
739 
740 	/*
741 	 * Dispatch the GPE to either an installed handler or the control
742 	 * method associated with this GPE (_Lxx or _Exx). If a handler
743 	 * exists, we invoke it and do not attempt to run the method.
744 	 * If there is neither a handler nor a method, leave the GPE
745 	 * disabled.
746 	 */
747 	switch (ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags)) {
748 	case ACPI_GPE_DISPATCH_HANDLER:
749 
750 		/* Invoke the installed handler (at interrupt level) */
751 
752 		return_value =
753 		    gpe_event_info->dispatch.handler->address(gpe_device,
754 							      gpe_number,
755 							      gpe_event_info->
756 							      dispatch.handler->
757 							      context);
758 
759 		/* If requested, clear (if level-triggered) and reenable the GPE */
760 
761 		if (return_value & ACPI_REENABLE_GPE) {
762 			(void)acpi_ev_finish_gpe(gpe_event_info);
763 		}
764 		break;
765 
766 	case ACPI_GPE_DISPATCH_METHOD:
767 	case ACPI_GPE_DISPATCH_NOTIFY:
768 		/*
769 		 * Execute the method associated with the GPE
770 		 * NOTE: Level-triggered GPEs are cleared after the method completes.
771 		 */
772 		status = acpi_os_execute(OSL_GPE_HANDLER,
773 					 acpi_ev_asynch_execute_gpe_method,
774 					 gpe_event_info);
775 		if (ACPI_FAILURE(status)) {
776 			ACPI_EXCEPTION((AE_INFO, status,
777 					"Unable to queue handler for GPE %02X - event disabled",
778 					gpe_number));
779 		}
780 		break;
781 
782 	default:
783 		/*
784 		 * No handler or method to run!
785 		 * 03/2010: This case should no longer be possible. We will not allow
786 		 * a GPE to be enabled if it has no handler or method.
787 		 */
788 		ACPI_ERROR((AE_INFO,
789 			    "No handler or method for GPE %02X, disabling event",
790 			    gpe_number));
791 
792 		break;
793 	}
794 
795 	return_UINT32(ACPI_INTERRUPT_HANDLED);
796 }
797 
798 #endif				/* !ACPI_REDUCED_HARDWARE */
799