xref: /titanic_50/usr/src/uts/intel/io/acpica/events/evgpe.c (revision 10d63b7db37a83b39c7f511cf9426c9d03ea0760)
1 /******************************************************************************
2  *
3  * Module Name: evgpe - General Purpose Event handling and dispatch
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2011, 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 /* Local prototypes */
53 
54 static void ACPI_SYSTEM_XFACE
55 AcpiEvAsynchExecuteGpeMethod (
56     void                    *Context);
57 
58 static void ACPI_SYSTEM_XFACE
59 AcpiEvAsynchEnableGpe (
60     void                    *Context);
61 
62 
63 /*******************************************************************************
64  *
65  * FUNCTION:    AcpiEvUpdateGpeEnableMask
66  *
67  * PARAMETERS:  GpeEventInfo            - GPE to update
68  *
69  * RETURN:      Status
70  *
71  * DESCRIPTION: Updates GPE register enable mask based upon whether there are
72  *              runtime references to this GPE
73  *
74  ******************************************************************************/
75 
76 ACPI_STATUS
77 AcpiEvUpdateGpeEnableMask (
78     ACPI_GPE_EVENT_INFO     *GpeEventInfo)
79 {
80     ACPI_GPE_REGISTER_INFO  *GpeRegisterInfo;
81     UINT32                  RegisterBit;
82 
83 
84     ACPI_FUNCTION_TRACE (EvUpdateGpeEnableMask);
85 
86 
87     GpeRegisterInfo = GpeEventInfo->RegisterInfo;
88     if (!GpeRegisterInfo)
89     {
90         return_ACPI_STATUS (AE_NOT_EXIST);
91     }
92 
93     RegisterBit = AcpiHwGetGpeRegisterBit (GpeEventInfo, GpeRegisterInfo);
94 
95     /* Clear the run bit up front */
96 
97     ACPI_CLEAR_BIT (GpeRegisterInfo->EnableForRun, RegisterBit);
98 
99     /* Set the mask bit only if there are references to this GPE */
100 
101     if (GpeEventInfo->RuntimeCount)
102     {
103         ACPI_SET_BIT (GpeRegisterInfo->EnableForRun, (UINT8) RegisterBit);
104     }
105 
106     return_ACPI_STATUS (AE_OK);
107 }
108 
109 
110 /*******************************************************************************
111  *
112  * FUNCTION:    AcpiEvEnableGpe
113  *
114  * PARAMETERS:  GpeEventInfo            - GPE to enable
115  *
116  * RETURN:      Status
117  *
118  * DESCRIPTION: Clear a GPE of stale events and enable it.
119  *
120  ******************************************************************************/
121 
122 ACPI_STATUS
123 AcpiEvEnableGpe (
124     ACPI_GPE_EVENT_INFO     *GpeEventInfo)
125 {
126     ACPI_STATUS             Status;
127 
128 
129     ACPI_FUNCTION_TRACE (EvEnableGpe);
130 
131 
132     /*
133      * We will only allow a GPE to be enabled if it has either an associated
134      * method (_Lxx/_Exx) or a handler, or is using the implicit notify
135      * feature. Otherwise, the GPE will be immediately disabled by
136      * AcpiEvGpeDispatch the first time it fires.
137      */
138     if ((GpeEventInfo->Flags & ACPI_GPE_DISPATCH_MASK) ==
139         ACPI_GPE_DISPATCH_NONE)
140     {
141         return_ACPI_STATUS (AE_NO_HANDLER);
142     }
143 
144     /* Clear the GPE (of stale events) */
145 
146     Status = AcpiHwClearGpe (GpeEventInfo);
147     if (ACPI_FAILURE (Status))
148     {
149         return_ACPI_STATUS (Status);
150     }
151 
152     /* Enable the requested GPE */
153 
154     Status = AcpiHwLowSetGpe (GpeEventInfo, ACPI_GPE_ENABLE);
155     return_ACPI_STATUS (Status);
156 }
157 
158 
159 /*******************************************************************************
160  *
161  * FUNCTION:    AcpiEvAddGpeReference
162  *
163  * PARAMETERS:  GpeEventInfo            - Add a reference to this GPE
164  *
165  * RETURN:      Status
166  *
167  * DESCRIPTION: Add a reference to a GPE. On the first reference, the GPE is
168  *              hardware-enabled.
169  *
170  ******************************************************************************/
171 
172 ACPI_STATUS
173 AcpiEvAddGpeReference (
174     ACPI_GPE_EVENT_INFO     *GpeEventInfo)
175 {
176     ACPI_STATUS             Status = AE_OK;
177 
178 
179     ACPI_FUNCTION_TRACE (EvAddGpeReference);
180 
181 
182     if (GpeEventInfo->RuntimeCount == ACPI_UINT8_MAX)
183     {
184         return_ACPI_STATUS (AE_LIMIT);
185     }
186 
187     GpeEventInfo->RuntimeCount++;
188     if (GpeEventInfo->RuntimeCount == 1)
189     {
190         /* Enable on first reference */
191 
192         Status = AcpiEvUpdateGpeEnableMask (GpeEventInfo);
193         if (ACPI_SUCCESS (Status))
194         {
195             Status = AcpiEvEnableGpe (GpeEventInfo);
196         }
197 
198         if (ACPI_FAILURE (Status))
199         {
200             GpeEventInfo->RuntimeCount--;
201         }
202     }
203 
204     return_ACPI_STATUS (Status);
205 }
206 
207 
208 /*******************************************************************************
209  *
210  * FUNCTION:    AcpiEvRemoveGpeReference
211  *
212  * PARAMETERS:  GpeEventInfo            - Remove a reference to this GPE
213  *
214  * RETURN:      Status
215  *
216  * DESCRIPTION: Remove a reference to a GPE. When the last reference is
217  *              removed, the GPE is hardware-disabled.
218  *
219  ******************************************************************************/
220 
221 ACPI_STATUS
222 AcpiEvRemoveGpeReference (
223     ACPI_GPE_EVENT_INFO     *GpeEventInfo)
224 {
225     ACPI_STATUS             Status = AE_OK;
226 
227 
228     ACPI_FUNCTION_TRACE (EvRemoveGpeReference);
229 
230 
231     if (!GpeEventInfo->RuntimeCount)
232     {
233         return_ACPI_STATUS (AE_LIMIT);
234     }
235 
236     GpeEventInfo->RuntimeCount--;
237     if (!GpeEventInfo->RuntimeCount)
238     {
239         /* Disable on last reference */
240 
241         Status = AcpiEvUpdateGpeEnableMask (GpeEventInfo);
242         if (ACPI_SUCCESS (Status))
243         {
244             Status = AcpiHwLowSetGpe (GpeEventInfo, ACPI_GPE_DISABLE);
245         }
246 
247         if (ACPI_FAILURE (Status))
248         {
249             GpeEventInfo->RuntimeCount++;
250         }
251     }
252 
253     return_ACPI_STATUS (Status);
254 }
255 
256 
257 /*******************************************************************************
258  *
259  * FUNCTION:    AcpiEvLowGetGpeInfo
260  *
261  * PARAMETERS:  GpeNumber           - Raw GPE number
262  *              GpeBlock            - A GPE info block
263  *
264  * RETURN:      A GPE EventInfo struct. NULL if not a valid GPE (The GpeNumber
265  *              is not within the specified GPE block)
266  *
267  * DESCRIPTION: Returns the EventInfo struct associated with this GPE. This is
268  *              the low-level implementation of EvGetGpeEventInfo.
269  *
270  ******************************************************************************/
271 
272 ACPI_GPE_EVENT_INFO *
273 AcpiEvLowGetGpeInfo (
274     UINT32                  GpeNumber,
275     ACPI_GPE_BLOCK_INFO     *GpeBlock)
276 {
277     UINT32                  GpeIndex;
278 
279 
280     /*
281      * Validate that the GpeNumber is within the specified GpeBlock.
282      * (Two steps)
283      */
284     if (!GpeBlock ||
285         (GpeNumber < GpeBlock->BlockBaseNumber))
286     {
287         return (NULL);
288     }
289 
290     GpeIndex = GpeNumber - GpeBlock->BlockBaseNumber;
291     if (GpeIndex >= GpeBlock->GpeCount)
292     {
293         return (NULL);
294     }
295 
296     return (&GpeBlock->EventInfo[GpeIndex]);
297 }
298 
299 
300 /*******************************************************************************
301  *
302  * FUNCTION:    AcpiEvGetGpeEventInfo
303  *
304  * PARAMETERS:  GpeDevice           - Device node. NULL for GPE0/GPE1
305  *              GpeNumber           - Raw GPE number
306  *
307  * RETURN:      A GPE EventInfo struct. NULL if not a valid GPE
308  *
309  * DESCRIPTION: Returns the EventInfo struct associated with this GPE.
310  *              Validates the GpeBlock and the GpeNumber
311  *
312  *              Should be called only when the GPE lists are semaphore locked
313  *              and not subject to change.
314  *
315  ******************************************************************************/
316 
317 ACPI_GPE_EVENT_INFO *
318 AcpiEvGetGpeEventInfo (
319     ACPI_HANDLE             GpeDevice,
320     UINT32                  GpeNumber)
321 {
322     ACPI_OPERAND_OBJECT     *ObjDesc;
323     ACPI_GPE_EVENT_INFO     *GpeInfo;
324     UINT32                  i;
325 
326 
327     ACPI_FUNCTION_ENTRY ();
328 
329 
330     /* A NULL GpeDevice means use the FADT-defined GPE block(s) */
331 
332     if (!GpeDevice)
333     {
334         /* Examine GPE Block 0 and 1 (These blocks are permanent) */
335 
336         for (i = 0; i < ACPI_MAX_GPE_BLOCKS; i++)
337         {
338             GpeInfo = AcpiEvLowGetGpeInfo (GpeNumber,
339                         AcpiGbl_GpeFadtBlocks[i]);
340             if (GpeInfo)
341             {
342                 return (GpeInfo);
343             }
344         }
345 
346         /* The GpeNumber was not in the range of either FADT GPE block */
347 
348         return (NULL);
349     }
350 
351     /* A Non-NULL GpeDevice means this is a GPE Block Device */
352 
353     ObjDesc = AcpiNsGetAttachedObject ((ACPI_NAMESPACE_NODE *) GpeDevice);
354     if (!ObjDesc ||
355         !ObjDesc->Device.GpeBlock)
356     {
357         return (NULL);
358     }
359 
360     return (AcpiEvLowGetGpeInfo (GpeNumber, ObjDesc->Device.GpeBlock));
361 }
362 
363 
364 /*******************************************************************************
365  *
366  * FUNCTION:    AcpiEvGpeDetect
367  *
368  * PARAMETERS:  GpeXruptList        - Interrupt block for this interrupt.
369  *                                    Can have multiple GPE blocks attached.
370  *
371  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
372  *
373  * DESCRIPTION: Detect if any GP events have occurred. This function is
374  *              executed at interrupt level.
375  *
376  ******************************************************************************/
377 
378 UINT32
379 AcpiEvGpeDetect (
380     ACPI_GPE_XRUPT_INFO     *GpeXruptList)
381 {
382     ACPI_STATUS             Status;
383     ACPI_GPE_BLOCK_INFO     *GpeBlock;
384     ACPI_GPE_REGISTER_INFO  *GpeRegisterInfo;
385     UINT32                  IntStatus = ACPI_INTERRUPT_NOT_HANDLED;
386     UINT8                   EnabledStatusByte;
387     UINT32                  StatusReg;
388     UINT32                  EnableReg;
389     ACPI_CPU_FLAGS          Flags;
390     UINT32                  i;
391     UINT32                  j;
392 
393 
394     ACPI_FUNCTION_NAME (EvGpeDetect);
395 
396     /* Check for the case where there are no GPEs */
397 
398     if (!GpeXruptList)
399     {
400         return (IntStatus);
401     }
402 
403     /*
404      * We need to obtain the GPE lock for both the data structs and registers
405      * Note: Not necessary to obtain the hardware lock, since the GPE
406      * registers are owned by the GpeLock.
407      */
408     Flags = AcpiOsAcquireLock (AcpiGbl_GpeLock);
409 
410     /* Examine all GPE blocks attached to this interrupt level */
411 
412     GpeBlock = GpeXruptList->GpeBlockListHead;
413     while (GpeBlock)
414     {
415         /*
416          * Read all of the 8-bit GPE status and enable registers in this GPE
417          * block, saving all of them. Find all currently active GP events.
418          */
419         for (i = 0; i < GpeBlock->RegisterCount; i++)
420         {
421             /* Get the next status/enable pair */
422 
423             GpeRegisterInfo = &GpeBlock->RegisterInfo[i];
424 
425             /*
426              * Optimization: If there are no GPEs enabled within this
427              * register, we can safely ignore the entire register.
428              */
429             if (!(GpeRegisterInfo->EnableForRun |
430                   GpeRegisterInfo->EnableForWake))
431             {
432                 continue;
433             }
434 
435             /* Read the Status Register */
436 
437             Status = AcpiHwRead (&StatusReg, &GpeRegisterInfo->StatusAddress);
438             if (ACPI_FAILURE (Status))
439             {
440                 goto UnlockAndExit;
441             }
442 
443             /* Read the Enable Register */
444 
445             Status = AcpiHwRead (&EnableReg, &GpeRegisterInfo->EnableAddress);
446             if (ACPI_FAILURE (Status))
447             {
448                 goto UnlockAndExit;
449             }
450 
451             ACPI_DEBUG_PRINT ((ACPI_DB_INTERRUPTS,
452                 "Read GPE Register at GPE%02X: Status=%02X, Enable=%02X\n",
453                 GpeRegisterInfo->BaseGpeNumber, StatusReg, EnableReg));
454 
455             /* Check if there is anything active at all in this register */
456 
457             EnabledStatusByte = (UINT8) (StatusReg & EnableReg);
458             if (!EnabledStatusByte)
459             {
460                 /* No active GPEs in this register, move on */
461 
462                 continue;
463             }
464 
465             /* Now look at the individual GPEs in this byte register */
466 
467             for (j = 0; j < ACPI_GPE_REGISTER_WIDTH; j++)
468             {
469                 /* Examine one GPE bit */
470 
471                 if (EnabledStatusByte & (1 << j))
472                 {
473                     /*
474                      * Found an active GPE. Dispatch the event to a handler
475                      * or method.
476                      */
477                     IntStatus |= AcpiEvGpeDispatch (GpeBlock->Node,
478                         &GpeBlock->EventInfo[((ACPI_SIZE) i *
479                             ACPI_GPE_REGISTER_WIDTH) + j],
480                         j + GpeRegisterInfo->BaseGpeNumber);
481                 }
482             }
483         }
484 
485         GpeBlock = GpeBlock->Next;
486     }
487 
488 UnlockAndExit:
489 
490     AcpiOsReleaseLock (AcpiGbl_GpeLock, Flags);
491     return (IntStatus);
492 }
493 
494 
495 /*******************************************************************************
496  *
497  * FUNCTION:    AcpiEvAsynchExecuteGpeMethod
498  *
499  * PARAMETERS:  Context (GpeEventInfo) - Info for this GPE
500  *
501  * RETURN:      None
502  *
503  * DESCRIPTION: Perform the actual execution of a GPE control method. This
504  *              function is called from an invocation of AcpiOsExecute and
505  *              therefore does NOT execute at interrupt level - so that
506  *              the control method itself is not executed in the context of
507  *              an interrupt handler.
508  *
509  ******************************************************************************/
510 
511 static void ACPI_SYSTEM_XFACE
512 AcpiEvAsynchExecuteGpeMethod (
513     void                    *Context)
514 {
515     ACPI_GPE_EVENT_INFO     *GpeEventInfo = Context;
516     ACPI_STATUS             Status;
517     ACPI_GPE_EVENT_INFO     *LocalGpeEventInfo;
518     ACPI_EVALUATE_INFO      *Info;
519 
520 
521     ACPI_FUNCTION_TRACE (EvAsynchExecuteGpeMethod);
522 
523 
524     /* Allocate a local GPE block */
525 
526     LocalGpeEventInfo = ACPI_ALLOCATE_ZEROED (sizeof (ACPI_GPE_EVENT_INFO));
527     if (!LocalGpeEventInfo)
528     {
529         ACPI_EXCEPTION ((AE_INFO, AE_NO_MEMORY,
530             "while handling a GPE"));
531         return_VOID;
532     }
533 
534     Status = AcpiUtAcquireMutex (ACPI_MTX_EVENTS);
535     if (ACPI_FAILURE (Status))
536     {
537         return_VOID;
538     }
539 
540     /* Must revalidate the GpeNumber/GpeBlock */
541 
542     if (!AcpiEvValidGpeEvent (GpeEventInfo))
543     {
544         Status = AcpiUtReleaseMutex (ACPI_MTX_EVENTS);
545         return_VOID;
546     }
547 
548     /*
549      * Take a snapshot of the GPE info for this level - we copy the info to
550      * prevent a race condition with RemoveHandler/RemoveBlock.
551      */
552     ACPI_MEMCPY (LocalGpeEventInfo, GpeEventInfo,
553         sizeof (ACPI_GPE_EVENT_INFO));
554 
555     Status = AcpiUtReleaseMutex (ACPI_MTX_EVENTS);
556     if (ACPI_FAILURE (Status))
557     {
558         return_VOID;
559     }
560 
561     /* Do the correct dispatch - normal method or implicit notify */
562 
563     switch (LocalGpeEventInfo->Flags & ACPI_GPE_DISPATCH_MASK)
564     {
565     case ACPI_GPE_DISPATCH_NOTIFY:
566 
567         /*
568          * Implicit notify.
569          * Dispatch a DEVICE_WAKE notify to the appropriate handler.
570          * NOTE: the request is queued for execution after this method
571          * completes. The notify handlers are NOT invoked synchronously
572          * from this thread -- because handlers may in turn run other
573          * control methods.
574          */
575         Status = AcpiEvQueueNotifyRequest (
576                     LocalGpeEventInfo->Dispatch.DeviceNode,
577                     ACPI_NOTIFY_DEVICE_WAKE);
578         break;
579 
580     case ACPI_GPE_DISPATCH_METHOD:
581 
582         /* Allocate the evaluation information block */
583 
584         Info = ACPI_ALLOCATE_ZEROED (sizeof (ACPI_EVALUATE_INFO));
585         if (!Info)
586         {
587             Status = AE_NO_MEMORY;
588         }
589         else
590         {
591             /*
592              * Invoke the GPE Method (_Lxx, _Exx) i.e., evaluate the
593              * _Lxx/_Exx control method that corresponds to this GPE
594              */
595             Info->PrefixNode = LocalGpeEventInfo->Dispatch.MethodNode;
596             Info->Flags = ACPI_IGNORE_RETURN_VALUE;
597 
598             Status = AcpiNsEvaluate (Info);
599             ACPI_FREE (Info);
600         }
601 
602         if (ACPI_FAILURE (Status))
603         {
604             ACPI_EXCEPTION ((AE_INFO, Status,
605                 "while evaluating GPE method [%4.4s]",
606                 AcpiUtGetNodeName (LocalGpeEventInfo->Dispatch.MethodNode)));
607         }
608 
609         break;
610 
611     default:
612         return_VOID; /* Should never happen */
613     }
614 
615     /* Defer enabling of GPE until all notify handlers are done */
616 
617     Status = AcpiOsExecute (OSL_NOTIFY_HANDLER,
618                 AcpiEvAsynchEnableGpe, LocalGpeEventInfo);
619     if (ACPI_FAILURE (Status))
620     {
621         ACPI_FREE (LocalGpeEventInfo);
622     }
623     return_VOID;
624 }
625 
626 
627 /*******************************************************************************
628  *
629  * FUNCTION:    AcpiEvAsynchEnableGpe
630  *
631  * PARAMETERS:  Context (GpeEventInfo) - Info for this GPE
632  *              Callback from AcpiOsExecute
633  *
634  * RETURN:      None
635  *
636  * DESCRIPTION: Asynchronous clear/enable for GPE. This allows the GPE to
637  *              complete (i.e., finish execution of Notify)
638  *
639  ******************************************************************************/
640 
641 static void ACPI_SYSTEM_XFACE
642 AcpiEvAsynchEnableGpe (
643     void                    *Context)
644 {
645     ACPI_GPE_EVENT_INFO     *GpeEventInfo = Context;
646 
647 
648     (void) AcpiEvFinishGpe (GpeEventInfo);
649 
650     ACPI_FREE (GpeEventInfo);
651     return;
652 }
653 
654 
655 /*******************************************************************************
656  *
657  * FUNCTION:    AcpiEvFinishGpe
658  *
659  * PARAMETERS:  GpeEventInfo        - Info for this GPE
660  *
661  * RETURN:      Status
662  *
663  * DESCRIPTION: Clear/Enable a GPE. Common code that is used after execution
664  *              of a GPE method or a synchronous or asynchronous GPE handler.
665  *
666  ******************************************************************************/
667 
668 ACPI_STATUS
669 AcpiEvFinishGpe (
670     ACPI_GPE_EVENT_INFO     *GpeEventInfo)
671 {
672     ACPI_STATUS             Status;
673 
674 
675     if ((GpeEventInfo->Flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
676             ACPI_GPE_LEVEL_TRIGGERED)
677     {
678         /*
679          * GPE is level-triggered, we clear the GPE status bit after
680          * handling the event.
681          */
682         Status = AcpiHwClearGpe (GpeEventInfo);
683         if (ACPI_FAILURE (Status))
684         {
685             return (Status);
686         }
687     }
688 
689     /*
690      * Enable this GPE, conditionally. This means that the GPE will
691      * only be physically enabled if the EnableForRun bit is set
692      * in the EventInfo.
693      */
694     (void) AcpiHwLowSetGpe (GpeEventInfo, ACPI_GPE_CONDITIONAL_ENABLE);
695     return (AE_OK);
696 }
697 
698 
699 /*******************************************************************************
700  *
701  * FUNCTION:    AcpiEvGpeDispatch
702  *
703  * PARAMETERS:  GpeDevice           - Device node. NULL for GPE0/GPE1
704  *              GpeEventInfo        - Info for this GPE
705  *              GpeNumber           - Number relative to the parent GPE block
706  *
707  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
708  *
709  * DESCRIPTION: Dispatch a General Purpose Event to either a function (e.g. EC)
710  *              or method (e.g. _Lxx/_Exx) handler.
711  *
712  *              This function executes at interrupt level.
713  *
714  ******************************************************************************/
715 
716 UINT32
717 AcpiEvGpeDispatch (
718     ACPI_NAMESPACE_NODE     *GpeDevice,
719     ACPI_GPE_EVENT_INFO     *GpeEventInfo,
720     UINT32                  GpeNumber)
721 {
722     ACPI_STATUS             Status;
723     UINT32                  ReturnValue;
724 
725 
726     ACPI_FUNCTION_TRACE (EvGpeDispatch);
727 
728 
729     /* Invoke global event handler if present */
730 
731     AcpiGpeCount++;
732     if (AcpiGbl_GlobalEventHandler)
733     {
734         AcpiGbl_GlobalEventHandler (ACPI_EVENT_TYPE_GPE, GpeDevice,
735              GpeNumber, AcpiGbl_GlobalEventHandlerContext);
736     }
737 
738     /*
739      * If edge-triggered, clear the GPE status bit now. Note that
740      * level-triggered events are cleared after the GPE is serviced.
741      */
742     if ((GpeEventInfo->Flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
743             ACPI_GPE_EDGE_TRIGGERED)
744     {
745         Status = AcpiHwClearGpe (GpeEventInfo);
746         if (ACPI_FAILURE (Status))
747         {
748             ACPI_EXCEPTION ((AE_INFO, Status,
749                 "Unable to clear GPE%02X", GpeNumber));
750             return_UINT32 (ACPI_INTERRUPT_NOT_HANDLED);
751         }
752     }
753 
754     /*
755      * Always disable the GPE so that it does not keep firing before
756      * any asynchronous activity completes (either from the execution
757      * of a GPE method or an asynchronous GPE handler.)
758      *
759      * If there is no handler or method to run, just disable the
760      * GPE and leave it disabled permanently to prevent further such
761      * pointless events from firing.
762      */
763     Status = AcpiHwLowSetGpe (GpeEventInfo, ACPI_GPE_DISABLE);
764     if (ACPI_FAILURE (Status))
765     {
766         ACPI_EXCEPTION ((AE_INFO, Status,
767             "Unable to disable GPE%02X", GpeNumber));
768         return_UINT32 (ACPI_INTERRUPT_NOT_HANDLED);
769     }
770 
771     /*
772      * Dispatch the GPE to either an installed handler or the control
773      * method associated with this GPE (_Lxx or _Exx). If a handler
774      * exists, we invoke it and do not attempt to run the method.
775      * If there is neither a handler nor a method, leave the GPE
776      * disabled.
777      */
778     switch (GpeEventInfo->Flags & ACPI_GPE_DISPATCH_MASK)
779     {
780     case ACPI_GPE_DISPATCH_HANDLER:
781 
782         /* Invoke the installed handler (at interrupt level) */
783 
784         ReturnValue = GpeEventInfo->Dispatch.Handler->Address (
785             GpeDevice, GpeNumber,
786             GpeEventInfo->Dispatch.Handler->Context);
787 
788         /* If requested, clear (if level-triggered) and reenable the GPE */
789 
790         if (ReturnValue & ACPI_REENABLE_GPE)
791         {
792             (void) AcpiEvFinishGpe (GpeEventInfo);
793         }
794         break;
795 
796     case ACPI_GPE_DISPATCH_METHOD:
797     case ACPI_GPE_DISPATCH_NOTIFY:
798 
799         /*
800          * Execute the method associated with the GPE
801          * NOTE: Level-triggered GPEs are cleared after the method completes.
802          */
803         Status = AcpiOsExecute (OSL_GPE_HANDLER,
804                     AcpiEvAsynchExecuteGpeMethod, GpeEventInfo);
805         if (ACPI_FAILURE (Status))
806         {
807             ACPI_EXCEPTION ((AE_INFO, Status,
808                 "Unable to queue handler for GPE%02X - event disabled",
809                 GpeNumber));
810         }
811         break;
812 
813     default:
814 
815         /*
816          * No handler or method to run!
817          * 03/2010: This case should no longer be possible. We will not allow
818          * a GPE to be enabled if it has no handler or method.
819          */
820         ACPI_ERROR ((AE_INFO,
821             "No handler or method for GPE%02X, disabling event",
822             GpeNumber));
823         break;
824     }
825 
826     return_UINT32 (ACPI_INTERRUPT_HANDLED);
827 }
828 
829