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.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 
52 #if (!ACPI_REDUCED_HARDWARE) /* Entire module */
53 
54 /* Local prototypes */
55 
56 static void ACPI_SYSTEM_XFACE
57 AcpiEvAsynchExecuteGpeMethod (
58     void                    *Context);
59 
60 static void ACPI_SYSTEM_XFACE
61 AcpiEvAsynchEnableGpe (
62     void                    *Context);
63 
64 
65 /*******************************************************************************
66  *
67  * FUNCTION:    AcpiEvUpdateGpeEnableMask
68  *
69  * PARAMETERS:  GpeEventInfo            - GPE to update
70  *
71  * RETURN:      Status
72  *
73  * DESCRIPTION: Updates GPE register enable mask based upon whether there are
74  *              runtime references to this GPE
75  *
76  ******************************************************************************/
77 
78 ACPI_STATUS
79 AcpiEvUpdateGpeEnableMask (
80     ACPI_GPE_EVENT_INFO     *GpeEventInfo)
81 {
82     ACPI_GPE_REGISTER_INFO  *GpeRegisterInfo;
83     UINT32                  RegisterBit;
84 
85 
86     ACPI_FUNCTION_TRACE (EvUpdateGpeEnableMask);
87 
88 
89     GpeRegisterInfo = GpeEventInfo->RegisterInfo;
90     if (!GpeRegisterInfo)
91     {
92         return_ACPI_STATUS (AE_NOT_EXIST);
93     }
94 
95     RegisterBit = AcpiHwGetGpeRegisterBit (GpeEventInfo);
96 
97     /* Clear the run bit up front */
98 
99     ACPI_CLEAR_BIT (GpeRegisterInfo->EnableForRun, RegisterBit);
100 
101     /* Set the mask bit only if there are references to this GPE */
102 
103     if (GpeEventInfo->RuntimeCount)
104     {
105         ACPI_SET_BIT (GpeRegisterInfo->EnableForRun, (UINT8) RegisterBit);
106     }
107     GpeRegisterInfo->EnableMask = GpeRegisterInfo->EnableForRun;
108 
109     return_ACPI_STATUS (AE_OK);
110 }
111 
112 
113 /*******************************************************************************
114  *
115  * FUNCTION:    AcpiEvEnableGpe
116  *
117  * PARAMETERS:  GpeEventInfo            - GPE to enable
118  *
119  * RETURN:      Status
120  *
121  * DESCRIPTION: Clear a GPE of stale events and enable it.
122  *
123  ******************************************************************************/
124 
125 ACPI_STATUS
126 AcpiEvEnableGpe (
127     ACPI_GPE_EVENT_INFO     *GpeEventInfo)
128 {
129     ACPI_STATUS             Status;
130 
131 
132     ACPI_FUNCTION_TRACE (EvEnableGpe);
133 
134 
135     /* Clear the GPE (of stale events) */
136 
137     Status = AcpiHwClearGpe (GpeEventInfo);
138     if (ACPI_FAILURE (Status))
139     {
140         return_ACPI_STATUS (Status);
141     }
142 
143     /* Enable the requested GPE */
144 
145     Status = AcpiHwLowSetGpe (GpeEventInfo, ACPI_GPE_ENABLE);
146     return_ACPI_STATUS (Status);
147 }
148 
149 
150 /*******************************************************************************
151  *
152  * FUNCTION:    AcpiEvAddGpeReference
153  *
154  * PARAMETERS:  GpeEventInfo            - Add a reference to this GPE
155  *
156  * RETURN:      Status
157  *
158  * DESCRIPTION: Add a reference to a GPE. On the first reference, the GPE is
159  *              hardware-enabled.
160  *
161  ******************************************************************************/
162 
163 ACPI_STATUS
164 AcpiEvAddGpeReference (
165     ACPI_GPE_EVENT_INFO     *GpeEventInfo)
166 {
167     ACPI_STATUS             Status = AE_OK;
168 
169 
170     ACPI_FUNCTION_TRACE (EvAddGpeReference);
171 
172 
173     if (GpeEventInfo->RuntimeCount == ACPI_UINT8_MAX)
174     {
175         return_ACPI_STATUS (AE_LIMIT);
176     }
177 
178     GpeEventInfo->RuntimeCount++;
179     if (GpeEventInfo->RuntimeCount == 1)
180     {
181         /* Enable on first reference */
182 
183         Status = AcpiEvUpdateGpeEnableMask (GpeEventInfo);
184         if (ACPI_SUCCESS (Status))
185         {
186             Status = AcpiEvEnableGpe (GpeEventInfo);
187         }
188 
189         if (ACPI_FAILURE (Status))
190         {
191             GpeEventInfo->RuntimeCount--;
192         }
193     }
194 
195     return_ACPI_STATUS (Status);
196 }
197 
198 
199 /*******************************************************************************
200  *
201  * FUNCTION:    AcpiEvRemoveGpeReference
202  *
203  * PARAMETERS:  GpeEventInfo            - Remove a reference to this GPE
204  *
205  * RETURN:      Status
206  *
207  * DESCRIPTION: Remove a reference to a GPE. When the last reference is
208  *              removed, the GPE is hardware-disabled.
209  *
210  ******************************************************************************/
211 
212 ACPI_STATUS
213 AcpiEvRemoveGpeReference (
214     ACPI_GPE_EVENT_INFO     *GpeEventInfo)
215 {
216     ACPI_STATUS             Status = AE_OK;
217 
218 
219     ACPI_FUNCTION_TRACE (EvRemoveGpeReference);
220 
221 
222     if (!GpeEventInfo->RuntimeCount)
223     {
224         return_ACPI_STATUS (AE_LIMIT);
225     }
226 
227     GpeEventInfo->RuntimeCount--;
228     if (!GpeEventInfo->RuntimeCount)
229     {
230         /* Disable on last reference */
231 
232         Status = AcpiEvUpdateGpeEnableMask (GpeEventInfo);
233         if (ACPI_SUCCESS (Status))
234         {
235             Status = AcpiHwLowSetGpe (GpeEventInfo, ACPI_GPE_DISABLE);
236         }
237 
238         if (ACPI_FAILURE (Status))
239         {
240             GpeEventInfo->RuntimeCount++;
241         }
242     }
243 
244     return_ACPI_STATUS (Status);
245 }
246 
247 
248 /*******************************************************************************
249  *
250  * FUNCTION:    AcpiEvLowGetGpeInfo
251  *
252  * PARAMETERS:  GpeNumber           - Raw GPE number
253  *              GpeBlock            - A GPE info block
254  *
255  * RETURN:      A GPE EventInfo struct. NULL if not a valid GPE (The GpeNumber
256  *              is not within the specified GPE block)
257  *
258  * DESCRIPTION: Returns the EventInfo struct associated with this GPE. This is
259  *              the low-level implementation of EvGetGpeEventInfo.
260  *
261  ******************************************************************************/
262 
263 ACPI_GPE_EVENT_INFO *
264 AcpiEvLowGetGpeInfo (
265     UINT32                  GpeNumber,
266     ACPI_GPE_BLOCK_INFO     *GpeBlock)
267 {
268     UINT32                  GpeIndex;
269 
270 
271     /*
272      * Validate that the GpeNumber is within the specified GpeBlock.
273      * (Two steps)
274      */
275     if (!GpeBlock ||
276         (GpeNumber < GpeBlock->BlockBaseNumber))
277     {
278         return (NULL);
279     }
280 
281     GpeIndex = GpeNumber - GpeBlock->BlockBaseNumber;
282     if (GpeIndex >= GpeBlock->GpeCount)
283     {
284         return (NULL);
285     }
286 
287     return (&GpeBlock->EventInfo[GpeIndex]);
288 }
289 
290 
291 /*******************************************************************************
292  *
293  * FUNCTION:    AcpiEvGetGpeEventInfo
294  *
295  * PARAMETERS:  GpeDevice           - Device node. NULL for GPE0/GPE1
296  *              GpeNumber           - Raw GPE number
297  *
298  * RETURN:      A GPE EventInfo struct. NULL if not a valid GPE
299  *
300  * DESCRIPTION: Returns the EventInfo struct associated with this GPE.
301  *              Validates the GpeBlock and the GpeNumber
302  *
303  *              Should be called only when the GPE lists are semaphore locked
304  *              and not subject to change.
305  *
306  ******************************************************************************/
307 
308 ACPI_GPE_EVENT_INFO *
309 AcpiEvGetGpeEventInfo (
310     ACPI_HANDLE             GpeDevice,
311     UINT32                  GpeNumber)
312 {
313     ACPI_OPERAND_OBJECT     *ObjDesc;
314     ACPI_GPE_EVENT_INFO     *GpeInfo;
315     UINT32                  i;
316 
317 
318     ACPI_FUNCTION_ENTRY ();
319 
320 
321     /* A NULL GpeDevice means use the FADT-defined GPE block(s) */
322 
323     if (!GpeDevice)
324     {
325         /* Examine GPE Block 0 and 1 (These blocks are permanent) */
326 
327         for (i = 0; i < ACPI_MAX_GPE_BLOCKS; i++)
328         {
329             GpeInfo = AcpiEvLowGetGpeInfo (GpeNumber,
330                         AcpiGbl_GpeFadtBlocks[i]);
331             if (GpeInfo)
332             {
333                 return (GpeInfo);
334             }
335         }
336 
337         /* The GpeNumber was not in the range of either FADT GPE block */
338 
339         return (NULL);
340     }
341 
342     /* A Non-NULL GpeDevice means this is a GPE Block Device */
343 
344     ObjDesc = AcpiNsGetAttachedObject ((ACPI_NAMESPACE_NODE *) GpeDevice);
345     if (!ObjDesc ||
346         !ObjDesc->Device.GpeBlock)
347     {
348         return (NULL);
349     }
350 
351     return (AcpiEvLowGetGpeInfo (GpeNumber, ObjDesc->Device.GpeBlock));
352 }
353 
354 
355 /*******************************************************************************
356  *
357  * FUNCTION:    AcpiEvGpeDetect
358  *
359  * PARAMETERS:  GpeXruptList        - Interrupt block for this interrupt.
360  *                                    Can have multiple GPE blocks attached.
361  *
362  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
363  *
364  * DESCRIPTION: Detect if any GP events have occurred. This function is
365  *              executed at interrupt level.
366  *
367  ******************************************************************************/
368 
369 UINT32
370 AcpiEvGpeDetect (
371     ACPI_GPE_XRUPT_INFO     *GpeXruptList)
372 {
373     ACPI_STATUS             Status;
374     ACPI_GPE_BLOCK_INFO     *GpeBlock;
375     ACPI_NAMESPACE_NODE     *GpeDevice;
376     ACPI_GPE_REGISTER_INFO  *GpeRegisterInfo;
377     ACPI_GPE_EVENT_INFO     *GpeEventInfo;
378     UINT32                  GpeNumber;
379     ACPI_GPE_HANDLER_INFO   *GpeHandlerInfo;
380     UINT32                  IntStatus = ACPI_INTERRUPT_NOT_HANDLED;
381     UINT8                   EnabledStatusByte;
382     UINT32                  StatusReg;
383     UINT32                  EnableReg;
384     ACPI_CPU_FLAGS          Flags;
385     UINT32                  i;
386     UINT32                  j;
387 
388 
389     ACPI_FUNCTION_NAME (EvGpeDetect);
390 
391     /* Check for the case where there are no GPEs */
392 
393     if (!GpeXruptList)
394     {
395         return (IntStatus);
396     }
397 
398     /*
399      * We need to obtain the GPE lock for both the data structs and registers
400      * Note: Not necessary to obtain the hardware lock, since the GPE
401      * registers are owned by the GpeLock.
402      */
403     Flags = AcpiOsAcquireLock (AcpiGbl_GpeLock);
404 
405     /* Examine all GPE blocks attached to this interrupt level */
406 
407     GpeBlock = GpeXruptList->GpeBlockListHead;
408     while (GpeBlock)
409     {
410         GpeDevice = GpeBlock->Node;
411 
412         /*
413          * Read all of the 8-bit GPE status and enable registers in this GPE
414          * block, saving all of them. Find all currently active GP events.
415          */
416         for (i = 0; i < GpeBlock->RegisterCount; i++)
417         {
418             /* Get the next status/enable pair */
419 
420             GpeRegisterInfo = &GpeBlock->RegisterInfo[i];
421 
422             /*
423              * Optimization: If there are no GPEs enabled within this
424              * register, we can safely ignore the entire register.
425              */
426             if (!(GpeRegisterInfo->EnableForRun |
427                   GpeRegisterInfo->EnableForWake))
428             {
429                 ACPI_DEBUG_PRINT ((ACPI_DB_INTERRUPTS,
430                     "Ignore disabled registers for GPE %02X-%02X: "
431                     "RunEnable=%02X, WakeEnable=%02X\n",
432                     GpeRegisterInfo->BaseGpeNumber,
433                     GpeRegisterInfo->BaseGpeNumber + (ACPI_GPE_REGISTER_WIDTH - 1),
434                     GpeRegisterInfo->EnableForRun,
435                     GpeRegisterInfo->EnableForWake));
436                 continue;
437             }
438 
439             /* Read the Status Register */
440 
441             Status = AcpiHwRead (&StatusReg, &GpeRegisterInfo->StatusAddress);
442             if (ACPI_FAILURE (Status))
443             {
444                 goto UnlockAndExit;
445             }
446 
447             /* Read the Enable Register */
448 
449             Status = AcpiHwRead (&EnableReg, &GpeRegisterInfo->EnableAddress);
450             if (ACPI_FAILURE (Status))
451             {
452                 goto UnlockAndExit;
453             }
454 
455             ACPI_DEBUG_PRINT ((ACPI_DB_INTERRUPTS,
456                 "Read registers for GPE %02X-%02X: Status=%02X, Enable=%02X, "
457                 "RunEnable=%02X, WakeEnable=%02X\n",
458                 GpeRegisterInfo->BaseGpeNumber,
459                 GpeRegisterInfo->BaseGpeNumber + (ACPI_GPE_REGISTER_WIDTH - 1),
460                 StatusReg, EnableReg,
461                 GpeRegisterInfo->EnableForRun,
462                 GpeRegisterInfo->EnableForWake));
463 
464             /* Check if there is anything active at all in this register */
465 
466             EnabledStatusByte = (UINT8) (StatusReg & EnableReg);
467             if (!EnabledStatusByte)
468             {
469                 /* No active GPEs in this register, move on */
470 
471                 continue;
472             }
473 
474             /* Now look at the individual GPEs in this byte register */
475 
476             for (j = 0; j < ACPI_GPE_REGISTER_WIDTH; j++)
477             {
478                 /* Examine one GPE bit */
479 
480                 GpeEventInfo = &GpeBlock->EventInfo[((ACPI_SIZE) i *
481                     ACPI_GPE_REGISTER_WIDTH) + j];
482                 GpeNumber = j + GpeRegisterInfo->BaseGpeNumber;
483 
484                 if (EnabledStatusByte & (1 << j))
485                 {
486                     /* Invoke global event handler if present */
487 
488                     AcpiGpeCount++;
489                     if (AcpiGbl_GlobalEventHandler)
490                     {
491                         AcpiGbl_GlobalEventHandler (ACPI_EVENT_TYPE_GPE,
492                             GpeDevice, GpeNumber,
493                             AcpiGbl_GlobalEventHandlerContext);
494                     }
495 
496                     /* Found an active GPE */
497 
498                     if (ACPI_GPE_DISPATCH_TYPE (GpeEventInfo->Flags) ==
499                         ACPI_GPE_DISPATCH_RAW_HANDLER)
500                     {
501                         /* Dispatch the event to a raw handler */
502 
503                         GpeHandlerInfo = GpeEventInfo->Dispatch.Handler;
504 
505                         /*
506                          * There is no protection around the namespace node
507                          * and the GPE handler to ensure a safe destruction
508                          * because:
509                          * 1. The namespace node is expected to always
510                          *    exist after loading a table.
511                          * 2. The GPE handler is expected to be flushed by
512                          *    AcpiOsWaitEventsComplete() before the
513                          *    destruction.
514                          */
515                         AcpiOsReleaseLock (AcpiGbl_GpeLock, Flags);
516                         IntStatus |= GpeHandlerInfo->Address (
517                             GpeDevice, GpeNumber, GpeHandlerInfo->Context);
518                         Flags = AcpiOsAcquireLock (AcpiGbl_GpeLock);
519                     }
520                     else
521                     {
522                         /*
523                          * Dispatch the event to a standard handler or
524                          * method.
525                          */
526                         IntStatus |= AcpiEvGpeDispatch (GpeDevice,
527                             GpeEventInfo, GpeNumber);
528                     }
529                 }
530             }
531         }
532 
533         GpeBlock = GpeBlock->Next;
534     }
535 
536 UnlockAndExit:
537 
538     AcpiOsReleaseLock (AcpiGbl_GpeLock, Flags);
539     return (IntStatus);
540 }
541 
542 
543 /*******************************************************************************
544  *
545  * FUNCTION:    AcpiEvAsynchExecuteGpeMethod
546  *
547  * PARAMETERS:  Context (GpeEventInfo) - Info for this GPE
548  *
549  * RETURN:      None
550  *
551  * DESCRIPTION: Perform the actual execution of a GPE control method. This
552  *              function is called from an invocation of AcpiOsExecute and
553  *              therefore does NOT execute at interrupt level - so that
554  *              the control method itself is not executed in the context of
555  *              an interrupt handler.
556  *
557  ******************************************************************************/
558 
559 static void ACPI_SYSTEM_XFACE
560 AcpiEvAsynchExecuteGpeMethod (
561     void                    *Context)
562 {
563     ACPI_GPE_EVENT_INFO     *GpeEventInfo = Context;
564     ACPI_STATUS             Status = AE_OK;
565     ACPI_EVALUATE_INFO      *Info;
566     ACPI_GPE_NOTIFY_INFO    *Notify;
567 
568 
569     ACPI_FUNCTION_TRACE (EvAsynchExecuteGpeMethod);
570 
571 
572     /* Do the correct dispatch - normal method or implicit notify */
573 
574     switch (ACPI_GPE_DISPATCH_TYPE (GpeEventInfo->Flags))
575     {
576     case ACPI_GPE_DISPATCH_NOTIFY:
577         /*
578          * Implicit notify.
579          * Dispatch a DEVICE_WAKE notify to the appropriate handler.
580          * NOTE: the request is queued for execution after this method
581          * completes. The notify handlers are NOT invoked synchronously
582          * from this thread -- because handlers may in turn run other
583          * control methods.
584          *
585          * June 2012: Expand implicit notify mechanism to support
586          * notifies on multiple device objects.
587          */
588         Notify = GpeEventInfo->Dispatch.NotifyList;
589         while (ACPI_SUCCESS (Status) && Notify)
590         {
591             Status = AcpiEvQueueNotifyRequest (Notify->DeviceNode,
592                         ACPI_NOTIFY_DEVICE_WAKE);
593 
594             Notify = Notify->Next;
595         }
596         break;
597 
598     case ACPI_GPE_DISPATCH_METHOD:
599 
600         /* Allocate the evaluation information block */
601 
602         Info = ACPI_ALLOCATE_ZEROED (sizeof (ACPI_EVALUATE_INFO));
603         if (!Info)
604         {
605             Status = AE_NO_MEMORY;
606         }
607         else
608         {
609             /*
610              * Invoke the GPE Method (_Lxx, _Exx) i.e., evaluate the
611              * _Lxx/_Exx control method that corresponds to this GPE
612              */
613             Info->PrefixNode = GpeEventInfo->Dispatch.MethodNode;
614             Info->Flags = ACPI_IGNORE_RETURN_VALUE;
615 
616             Status = AcpiNsEvaluate (Info);
617             ACPI_FREE (Info);
618         }
619 
620         if (ACPI_FAILURE (Status))
621         {
622             ACPI_EXCEPTION ((AE_INFO, Status,
623                 "while evaluating GPE method [%4.4s]",
624                 AcpiUtGetNodeName (GpeEventInfo->Dispatch.MethodNode)));
625         }
626         break;
627 
628     default:
629 
630         goto ErrorExit; /* Should never happen */
631     }
632 
633     /* Defer enabling of GPE until all notify handlers are done */
634 
635     Status = AcpiOsExecute (OSL_NOTIFY_HANDLER,
636                 AcpiEvAsynchEnableGpe, GpeEventInfo);
637     if (ACPI_SUCCESS (Status))
638     {
639         return_VOID;
640     }
641 
642 ErrorExit:
643     AcpiEvAsynchEnableGpe (GpeEventInfo);
644     return_VOID;
645 }
646 
647 
648 /*******************************************************************************
649  *
650  * FUNCTION:    AcpiEvAsynchEnableGpe
651  *
652  * PARAMETERS:  Context (GpeEventInfo) - Info for this GPE
653  *              Callback from AcpiOsExecute
654  *
655  * RETURN:      None
656  *
657  * DESCRIPTION: Asynchronous clear/enable for GPE. This allows the GPE to
658  *              complete (i.e., finish execution of Notify)
659  *
660  ******************************************************************************/
661 
662 static void ACPI_SYSTEM_XFACE
663 AcpiEvAsynchEnableGpe (
664     void                    *Context)
665 {
666     ACPI_GPE_EVENT_INFO     *GpeEventInfo = Context;
667     ACPI_CPU_FLAGS          Flags;
668 
669 
670     Flags = AcpiOsAcquireLock (AcpiGbl_GpeLock);
671     (void) AcpiEvFinishGpe (GpeEventInfo);
672     AcpiOsReleaseLock (AcpiGbl_GpeLock, Flags);
673 
674     return;
675 }
676 
677 
678 /*******************************************************************************
679  *
680  * FUNCTION:    AcpiEvFinishGpe
681  *
682  * PARAMETERS:  GpeEventInfo        - Info for this GPE
683  *
684  * RETURN:      Status
685  *
686  * DESCRIPTION: Clear/Enable a GPE. Common code that is used after execution
687  *              of a GPE method or a synchronous or asynchronous GPE handler.
688  *
689  ******************************************************************************/
690 
691 ACPI_STATUS
692 AcpiEvFinishGpe (
693     ACPI_GPE_EVENT_INFO     *GpeEventInfo)
694 {
695     ACPI_STATUS             Status;
696 
697 
698     if ((GpeEventInfo->Flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
699             ACPI_GPE_LEVEL_TRIGGERED)
700     {
701         /*
702          * GPE is level-triggered, we clear the GPE status bit after
703          * handling the event.
704          */
705         Status = AcpiHwClearGpe (GpeEventInfo);
706         if (ACPI_FAILURE (Status))
707         {
708             return (Status);
709         }
710     }
711 
712     /*
713      * Enable this GPE, conditionally. This means that the GPE will
714      * only be physically enabled if the EnableMask bit is set
715      * in the EventInfo.
716      */
717     (void) AcpiHwLowSetGpe (GpeEventInfo, ACPI_GPE_CONDITIONAL_ENABLE);
718     return (AE_OK);
719 }
720 
721 
722 /*******************************************************************************
723  *
724  * FUNCTION:    AcpiEvGpeDispatch
725  *
726  * PARAMETERS:  GpeDevice           - Device node. NULL for GPE0/GPE1
727  *              GpeEventInfo        - Info for this GPE
728  *              GpeNumber           - Number relative to the parent GPE block
729  *
730  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
731  *
732  * DESCRIPTION: Dispatch a General Purpose Event to either a function (e.g. EC)
733  *              or method (e.g. _Lxx/_Exx) handler.
734  *
735  *              This function executes at interrupt level.
736  *
737  ******************************************************************************/
738 
739 UINT32
740 AcpiEvGpeDispatch (
741     ACPI_NAMESPACE_NODE     *GpeDevice,
742     ACPI_GPE_EVENT_INFO     *GpeEventInfo,
743     UINT32                  GpeNumber)
744 {
745     ACPI_STATUS             Status;
746     UINT32                  ReturnValue;
747 
748 
749     ACPI_FUNCTION_TRACE (EvGpeDispatch);
750 
751 
752     /*
753      * Always disable the GPE so that it does not keep firing before
754      * any asynchronous activity completes (either from the execution
755      * of a GPE method or an asynchronous GPE handler.)
756      *
757      * If there is no handler or method to run, just disable the
758      * GPE and leave it disabled permanently to prevent further such
759      * pointless events from firing.
760      */
761     Status = AcpiHwLowSetGpe (GpeEventInfo, ACPI_GPE_DISABLE);
762     if (ACPI_FAILURE (Status))
763     {
764         ACPI_EXCEPTION ((AE_INFO, Status,
765             "Unable to disable GPE %02X", GpeNumber));
766         return_UINT32 (ACPI_INTERRUPT_NOT_HANDLED);
767     }
768 
769     /*
770      * If edge-triggered, clear the GPE status bit now. Note that
771      * level-triggered events are cleared after the GPE is serviced.
772      */
773     if ((GpeEventInfo->Flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
774             ACPI_GPE_EDGE_TRIGGERED)
775     {
776         Status = AcpiHwClearGpe (GpeEventInfo);
777         if (ACPI_FAILURE (Status))
778         {
779             ACPI_EXCEPTION ((AE_INFO, Status,
780                 "Unable to clear GPE %02X", GpeNumber));
781             (void) AcpiHwLowSetGpe (GpeEventInfo,
782                     ACPI_GPE_CONDITIONAL_ENABLE);
783             return_UINT32 (ACPI_INTERRUPT_NOT_HANDLED);
784         }
785     }
786 
787     /*
788      * Dispatch the GPE to either an installed handler or the control
789      * method associated with this GPE (_Lxx or _Exx). If a handler
790      * exists, we invoke it and do not attempt to run the method.
791      * If there is neither a handler nor a method, leave the GPE
792      * disabled.
793      */
794     switch (ACPI_GPE_DISPATCH_TYPE (GpeEventInfo->Flags))
795     {
796     case ACPI_GPE_DISPATCH_HANDLER:
797 
798         /* Invoke the installed handler (at interrupt level) */
799 
800         ReturnValue = GpeEventInfo->Dispatch.Handler->Address (
801             GpeDevice, GpeNumber,
802             GpeEventInfo->Dispatch.Handler->Context);
803 
804         /* If requested, clear (if level-triggered) and reenable the GPE */
805 
806         if (ReturnValue & ACPI_REENABLE_GPE)
807         {
808             (void) AcpiEvFinishGpe (GpeEventInfo);
809         }
810         break;
811 
812     case ACPI_GPE_DISPATCH_METHOD:
813     case ACPI_GPE_DISPATCH_NOTIFY:
814         /*
815          * Execute the method associated with the GPE
816          * NOTE: Level-triggered GPEs are cleared after the method completes.
817          */
818         Status = AcpiOsExecute (OSL_GPE_HANDLER,
819                     AcpiEvAsynchExecuteGpeMethod, GpeEventInfo);
820         if (ACPI_FAILURE (Status))
821         {
822             ACPI_EXCEPTION ((AE_INFO, Status,
823                 "Unable to queue handler for GPE %02X - event disabled",
824                 GpeNumber));
825         }
826         break;
827 
828     default:
829         /*
830          * No handler or method to run!
831          * 03/2010: This case should no longer be possible. We will not allow
832          * a GPE to be enabled if it has no handler or method.
833          */
834         ACPI_ERROR ((AE_INFO,
835             "No handler or method for GPE %02X, disabling event",
836             GpeNumber));
837         break;
838     }
839 
840     return_UINT32 (ACPI_INTERRUPT_HANDLED);
841 }
842 
843 #endif /* !ACPI_REDUCED_HARDWARE */
844