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1 /******************************************************************************
2  *
3  * Module Name: evgpe - General Purpose Event handling and dispatch
4  *
5  *****************************************************************************/
6
7 /*
8  * Copyright (C) 2000 - 2013, 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 acpi_status acpi_ev_enable_gpe(struct acpi_gpe_event_info *gpe_event_info)
111 {
112         acpi_status status;
113
114         ACPI_FUNCTION_TRACE(ev_enable_gpe);
115
116         /*
117          * We will only allow a GPE to be enabled if it has either an associated
118          * method (_Lxx/_Exx) or a handler, or is using the implicit notify
119          * feature. Otherwise, the GPE will be immediately disabled by
120          * acpi_ev_gpe_dispatch the first time it fires.
121          */
122         if ((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) ==
123             ACPI_GPE_DISPATCH_NONE) {
124                 return_ACPI_STATUS(AE_NO_HANDLER);
125         }
126
127         /* Clear the GPE (of stale events) */
128         status = acpi_hw_clear_gpe(gpe_event_info);
129         if (ACPI_FAILURE(status)) {
130                 return_ACPI_STATUS(status);
131         }
132
133         /* Enable the requested GPE */
134
135         status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_ENABLE);
136         return_ACPI_STATUS(status);
137 }
138
139
140 /*******************************************************************************
141  *
142  * FUNCTION:    acpi_ev_add_gpe_reference
143  *
144  * PARAMETERS:  gpe_event_info          - Add a reference to this GPE
145  *
146  * RETURN:      Status
147  *
148  * DESCRIPTION: Add a reference to a GPE. On the first reference, the GPE is
149  *              hardware-enabled.
150  *
151  ******************************************************************************/
152
153 acpi_status
154 acpi_ev_add_gpe_reference(struct acpi_gpe_event_info *gpe_event_info)
155 {
156         acpi_status status = AE_OK;
157
158         ACPI_FUNCTION_TRACE(ev_add_gpe_reference);
159
160         if (gpe_event_info->runtime_count == ACPI_UINT8_MAX) {
161                 return_ACPI_STATUS(AE_LIMIT);
162         }
163
164         gpe_event_info->runtime_count++;
165         if (gpe_event_info->runtime_count == 1) {
166
167                 /* Enable on first reference */
168
169                 status = acpi_ev_update_gpe_enable_mask(gpe_event_info);
170                 if (ACPI_SUCCESS(status)) {
171                         status = acpi_ev_enable_gpe(gpe_event_info);
172                 }
173
174                 if (ACPI_FAILURE(status)) {
175                         gpe_event_info->runtime_count--;
176                 }
177         }
178
179         return_ACPI_STATUS(status);
180 }
181
182 /*******************************************************************************
183  *
184  * FUNCTION:    acpi_ev_remove_gpe_reference
185  *
186  * PARAMETERS:  gpe_event_info          - Remove a reference to this GPE
187  *
188  * RETURN:      Status
189  *
190  * DESCRIPTION: Remove a reference to a GPE. When the last reference is
191  *              removed, the GPE is hardware-disabled.
192  *
193  ******************************************************************************/
194
195 acpi_status
196 acpi_ev_remove_gpe_reference(struct acpi_gpe_event_info *gpe_event_info)
197 {
198         acpi_status status = AE_OK;
199
200         ACPI_FUNCTION_TRACE(ev_remove_gpe_reference);
201
202         if (!gpe_event_info->runtime_count) {
203                 return_ACPI_STATUS(AE_LIMIT);
204         }
205
206         gpe_event_info->runtime_count--;
207         if (!gpe_event_info->runtime_count) {
208
209                 /* Disable on last reference */
210
211                 status = acpi_ev_update_gpe_enable_mask(gpe_event_info);
212                 if (ACPI_SUCCESS(status)) {
213                         status =
214                             acpi_hw_low_set_gpe(gpe_event_info,
215                                                      ACPI_GPE_DISABLE);
216                 }
217
218                 if (ACPI_FAILURE(status)) {
219                         gpe_event_info->runtime_count++;
220                 }
221         }
222
223         return_ACPI_STATUS(status);
224 }
225
226 /*******************************************************************************
227  *
228  * FUNCTION:    acpi_ev_low_get_gpe_info
229  *
230  * PARAMETERS:  gpe_number          - Raw GPE number
231  *              gpe_block           - A GPE info block
232  *
233  * RETURN:      A GPE event_info struct. NULL if not a valid GPE (The gpe_number
234  *              is not within the specified GPE block)
235  *
236  * DESCRIPTION: Returns the event_info struct associated with this GPE. This is
237  *              the low-level implementation of ev_get_gpe_event_info.
238  *
239  ******************************************************************************/
240
241 struct acpi_gpe_event_info *acpi_ev_low_get_gpe_info(u32 gpe_number,
242                                                      struct acpi_gpe_block_info
243                                                      *gpe_block)
244 {
245         u32 gpe_index;
246
247         /*
248          * Validate that the gpe_number is within the specified gpe_block.
249          * (Two steps)
250          */
251         if (!gpe_block || (gpe_number < gpe_block->block_base_number)) {
252                 return (NULL);
253         }
254
255         gpe_index = gpe_number - gpe_block->block_base_number;
256         if (gpe_index >= gpe_block->gpe_count) {
257                 return (NULL);
258         }
259
260         return (&gpe_block->event_info[gpe_index]);
261 }
262
263
264 /*******************************************************************************
265  *
266  * FUNCTION:    acpi_ev_get_gpe_event_info
267  *
268  * PARAMETERS:  gpe_device          - Device node. NULL for GPE0/GPE1
269  *              gpe_number          - Raw GPE number
270  *
271  * RETURN:      A GPE event_info struct. NULL if not a valid GPE
272  *
273  * DESCRIPTION: Returns the event_info struct associated with this GPE.
274  *              Validates the gpe_block and the gpe_number
275  *
276  *              Should be called only when the GPE lists are semaphore locked
277  *              and not subject to change.
278  *
279  ******************************************************************************/
280
281 struct acpi_gpe_event_info *acpi_ev_get_gpe_event_info(acpi_handle gpe_device,
282                                                        u32 gpe_number)
283 {
284         union acpi_operand_object *obj_desc;
285         struct acpi_gpe_event_info *gpe_info;
286         u32 i;
287
288         ACPI_FUNCTION_ENTRY();
289
290         /* A NULL gpe_device means use the FADT-defined GPE block(s) */
291
292         if (!gpe_device) {
293
294                 /* Examine GPE Block 0 and 1 (These blocks are permanent) */
295
296                 for (i = 0; i < ACPI_MAX_GPE_BLOCKS; i++) {
297                         gpe_info = acpi_ev_low_get_gpe_info(gpe_number,
298                                                             acpi_gbl_gpe_fadt_blocks
299                                                             [i]);
300                         if (gpe_info) {
301                                 return (gpe_info);
302                         }
303                 }
304
305                 /* The gpe_number was not in the range of either FADT GPE block */
306
307                 return (NULL);
308         }
309
310         /* A Non-NULL gpe_device means this is a GPE Block Device */
311
312         obj_desc =
313             acpi_ns_get_attached_object((struct acpi_namespace_node *)
314                                                gpe_device);
315         if (!obj_desc || !obj_desc->device.gpe_block) {
316                 return (NULL);
317         }
318
319         return (acpi_ev_low_get_gpe_info
320                 (gpe_number, obj_desc->device.gpe_block));
321 }
322
323 /*******************************************************************************
324  *
325  * FUNCTION:    acpi_ev_gpe_detect
326  *
327  * PARAMETERS:  gpe_xrupt_list      - Interrupt block for this interrupt.
328  *                                    Can have multiple GPE blocks attached.
329  *
330  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
331  *
332  * DESCRIPTION: Detect if any GP events have occurred. This function is
333  *              executed at interrupt level.
334  *
335  ******************************************************************************/
336
337 u32 acpi_ev_gpe_detect(struct acpi_gpe_xrupt_info * gpe_xrupt_list)
338 {
339         acpi_status status;
340         struct acpi_gpe_block_info *gpe_block;
341         struct acpi_gpe_register_info *gpe_register_info;
342         u32 int_status = ACPI_INTERRUPT_NOT_HANDLED;
343         u8 enabled_status_byte;
344         u32 status_reg;
345         u32 enable_reg;
346         acpi_cpu_flags flags;
347         u32 i;
348         u32 j;
349
350         ACPI_FUNCTION_NAME(ev_gpe_detect);
351
352         /* Check for the case where there are no GPEs */
353
354         if (!gpe_xrupt_list) {
355                 return (int_status);
356         }
357
358         /*
359          * We need to obtain the GPE lock for both the data structs and registers
360          * Note: Not necessary to obtain the hardware lock, since the GPE
361          * registers are owned by the gpe_lock.
362          */
363         flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
364
365         /* Examine all GPE blocks attached to this interrupt level */
366
367         gpe_block = gpe_xrupt_list->gpe_block_list_head;
368         while (gpe_block) {
369                 /*
370                  * Read all of the 8-bit GPE status and enable registers in this GPE
371                  * block, saving all of them. Find all currently active GP events.
372                  */
373                 for (i = 0; i < gpe_block->register_count; i++) {
374
375                         /* Get the next status/enable pair */
376
377                         gpe_register_info = &gpe_block->register_info[i];
378
379                         /*
380                          * Optimization: If there are no GPEs enabled within this
381                          * register, we can safely ignore the entire register.
382                          */
383                         if (!(gpe_register_info->enable_for_run |
384                               gpe_register_info->enable_for_wake)) {
385                                 ACPI_DEBUG_PRINT((ACPI_DB_INTERRUPTS,
386                                                   "Ignore disabled registers for GPE%02X-GPE%02X: "
387                                                   "RunEnable=%02X, WakeEnable=%02X\n",
388                                                   gpe_register_info->
389                                                   base_gpe_number,
390                                                   gpe_register_info->
391                                                   base_gpe_number +
392                                                   (ACPI_GPE_REGISTER_WIDTH - 1),
393                                                   gpe_register_info->
394                                                   enable_for_run,
395                                                   gpe_register_info->
396                                                   enable_for_wake));
397                                 continue;
398                         }
399
400                         /* Read the Status Register */
401
402                         status =
403                             acpi_hw_read(&status_reg,
404                                          &gpe_register_info->status_address);
405                         if (ACPI_FAILURE(status)) {
406                                 goto unlock_and_exit;
407                         }
408
409                         /* Read the Enable Register */
410
411                         status =
412                             acpi_hw_read(&enable_reg,
413                                          &gpe_register_info->enable_address);
414                         if (ACPI_FAILURE(status)) {
415                                 goto unlock_and_exit;
416                         }
417
418                         ACPI_DEBUG_PRINT((ACPI_DB_INTERRUPTS,
419                                           "Read registers for GPE%02X-GPE%02X: Status=%02X, Enable=%02X, "
420                                           "RunEnable=%02X, WakeEnable=%02X\n",
421                                           gpe_register_info->base_gpe_number,
422                                           gpe_register_info->base_gpe_number +
423                                           (ACPI_GPE_REGISTER_WIDTH - 1),
424                                           status_reg, enable_reg,
425                                           gpe_register_info->enable_for_run,
426                                           gpe_register_info->enable_for_wake));
427
428                         /* Check if there is anything active at all in this register */
429
430                         enabled_status_byte = (u8) (status_reg & enable_reg);
431                         if (!enabled_status_byte) {
432
433                                 /* No active GPEs in this register, move on */
434
435                                 continue;
436                         }
437
438                         /* Now look at the individual GPEs in this byte register */
439
440                         for (j = 0; j < ACPI_GPE_REGISTER_WIDTH; j++) {
441
442                                 /* Examine one GPE bit */
443
444                                 if (enabled_status_byte & (1 << j)) {
445                                         /*
446                                          * Found an active GPE. Dispatch the event to a handler
447                                          * or method.
448                                          */
449                                         int_status |=
450                                             acpi_ev_gpe_dispatch(gpe_block->
451                                                                  node,
452                                                                  &gpe_block->
453                                                 event_info[((acpi_size) i * ACPI_GPE_REGISTER_WIDTH) + j], j + gpe_register_info->base_gpe_number);
454                                 }
455                         }
456                 }
457
458                 gpe_block = gpe_block->next;
459         }
460
461       unlock_and_exit:
462
463         acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
464         return (int_status);
465 }
466
467 /*******************************************************************************
468  *
469  * FUNCTION:    acpi_ev_asynch_execute_gpe_method
470  *
471  * PARAMETERS:  Context (gpe_event_info) - Info for this GPE
472  *
473  * RETURN:      None
474  *
475  * DESCRIPTION: Perform the actual execution of a GPE control method. This
476  *              function is called from an invocation of acpi_os_execute and
477  *              therefore does NOT execute at interrupt level - so that
478  *              the control method itself is not executed in the context of
479  *              an interrupt handler.
480  *
481  ******************************************************************************/
482
483 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
484 {
485         struct acpi_gpe_event_info *gpe_event_info = context;
486         acpi_status status;
487         struct acpi_gpe_event_info *local_gpe_event_info;
488         struct acpi_evaluate_info *info;
489         struct acpi_gpe_notify_info *notify;
490
491         ACPI_FUNCTION_TRACE(ev_asynch_execute_gpe_method);
492
493         /* Allocate a local GPE block */
494
495         local_gpe_event_info =
496             ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_gpe_event_info));
497         if (!local_gpe_event_info) {
498                 ACPI_EXCEPTION((AE_INFO, AE_NO_MEMORY, "while handling a GPE"));
499                 return_VOID;
500         }
501
502         status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
503         if (ACPI_FAILURE(status)) {
504                 ACPI_FREE(local_gpe_event_info);
505                 return_VOID;
506         }
507
508         /* Must revalidate the gpe_number/gpe_block */
509
510         if (!acpi_ev_valid_gpe_event(gpe_event_info)) {
511                 status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
512                 ACPI_FREE(local_gpe_event_info);
513                 return_VOID;
514         }
515
516         /*
517          * Take a snapshot of the GPE info for this level - we copy the info to
518          * prevent a race condition with remove_handler/remove_block.
519          */
520         ACPI_MEMCPY(local_gpe_event_info, gpe_event_info,
521                     sizeof(struct acpi_gpe_event_info));
522
523         status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
524         if (ACPI_FAILURE(status)) {
525                 return_VOID;
526         }
527
528         /* Do the correct dispatch - normal method or implicit notify */
529
530         switch (local_gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) {
531         case ACPI_GPE_DISPATCH_NOTIFY:
532
533                 /*
534                  * Implicit notify.
535                  * Dispatch a DEVICE_WAKE notify to the appropriate handler.
536                  * NOTE: the request is queued for execution after this method
537                  * completes. The notify handlers are NOT invoked synchronously
538                  * from this thread -- because handlers may in turn run other
539                  * control methods.
540                  *
541                  * June 2012: Expand implicit notify mechanism to support
542                  * notifies on multiple device objects.
543                  */
544                 notify = local_gpe_event_info->dispatch.notify_list;
545                 while (ACPI_SUCCESS(status) && notify) {
546                         status =
547                             acpi_ev_queue_notify_request(notify->device_node,
548                                                          ACPI_NOTIFY_DEVICE_WAKE);
549
550                         notify = notify->next;
551                 }
552
553                 break;
554
555         case ACPI_GPE_DISPATCH_METHOD:
556
557                 /* Allocate the evaluation information block */
558
559                 info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
560                 if (!info) {
561                         status = AE_NO_MEMORY;
562                 } else {
563                         /*
564                          * Invoke the GPE Method (_Lxx, _Exx) i.e., evaluate the
565                          * _Lxx/_Exx control method that corresponds to this GPE
566                          */
567                         info->prefix_node =
568                             local_gpe_event_info->dispatch.method_node;
569                         info->flags = ACPI_IGNORE_RETURN_VALUE;
570
571                         status = acpi_ns_evaluate(info);
572                         ACPI_FREE(info);
573                 }
574
575                 if (ACPI_FAILURE(status)) {
576                         ACPI_EXCEPTION((AE_INFO, status,
577                                         "while evaluating GPE method [%4.4s]",
578                                         acpi_ut_get_node_name
579                                         (local_gpe_event_info->dispatch.
580                                          method_node)));
581                 }
582
583                 break;
584
585         default:
586                 return_VOID;    /* Should never happen */
587         }
588
589         /* Defer enabling of GPE until all notify handlers are done */
590
591         status = acpi_os_execute(OSL_NOTIFY_HANDLER,
592                                  acpi_ev_asynch_enable_gpe,
593                                  local_gpe_event_info);
594         if (ACPI_FAILURE(status)) {
595                 ACPI_FREE(local_gpe_event_info);
596         }
597         return_VOID;
598 }
599
600
601 /*******************************************************************************
602  *
603  * FUNCTION:    acpi_ev_asynch_enable_gpe
604  *
605  * PARAMETERS:  Context (gpe_event_info) - Info for this GPE
606  *              Callback from acpi_os_execute
607  *
608  * RETURN:      None
609  *
610  * DESCRIPTION: Asynchronous clear/enable for GPE. This allows the GPE to
611  *              complete (i.e., finish execution of Notify)
612  *
613  ******************************************************************************/
614
615 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_enable_gpe(void *context)
616 {
617         struct acpi_gpe_event_info *gpe_event_info = context;
618
619         (void)acpi_ev_finish_gpe(gpe_event_info);
620
621         ACPI_FREE(gpe_event_info);
622         return;
623 }
624
625
626 /*******************************************************************************
627  *
628  * FUNCTION:    acpi_ev_finish_gpe
629  *
630  * PARAMETERS:  gpe_event_info      - Info for this GPE
631  *
632  * RETURN:      Status
633  *
634  * DESCRIPTION: Clear/Enable a GPE. Common code that is used after execution
635  *              of a GPE method or a synchronous or asynchronous GPE handler.
636  *
637  ******************************************************************************/
638
639 acpi_status acpi_ev_finish_gpe(struct acpi_gpe_event_info *gpe_event_info)
640 {
641         acpi_status status;
642
643         if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
644             ACPI_GPE_LEVEL_TRIGGERED) {
645                 /*
646                  * GPE is level-triggered, we clear the GPE status bit after
647                  * handling the event.
648                  */
649                 status = acpi_hw_clear_gpe(gpe_event_info);
650                 if (ACPI_FAILURE(status)) {
651                         return (status);
652                 }
653         }
654
655         /*
656          * Enable this GPE, conditionally. This means that the GPE will
657          * only be physically enabled if the enable_for_run bit is set
658          * in the event_info.
659          */
660         (void)acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_CONDITIONAL_ENABLE);
661         return (AE_OK);
662 }
663
664
665 /*******************************************************************************
666  *
667  * FUNCTION:    acpi_ev_gpe_dispatch
668  *
669  * PARAMETERS:  gpe_device      - Device node. NULL for GPE0/GPE1
670  *              gpe_event_info  - Info for this GPE
671  *              gpe_number      - Number relative to the parent GPE block
672  *
673  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
674  *
675  * DESCRIPTION: Dispatch a General Purpose Event to either a function (e.g. EC)
676  *              or method (e.g. _Lxx/_Exx) handler.
677  *
678  *              This function executes at interrupt level.
679  *
680  ******************************************************************************/
681
682 u32
683 acpi_ev_gpe_dispatch(struct acpi_namespace_node *gpe_device,
684                     struct acpi_gpe_event_info *gpe_event_info, u32 gpe_number)
685 {
686         acpi_status status;
687         u32 return_value;
688
689         ACPI_FUNCTION_TRACE(ev_gpe_dispatch);
690
691         /* Invoke global event handler if present */
692
693         acpi_gpe_count++;
694         if (acpi_gbl_global_event_handler) {
695                 acpi_gbl_global_event_handler(ACPI_EVENT_TYPE_GPE, gpe_device,
696                                               gpe_number,
697                                               acpi_gbl_global_event_handler_context);
698         }
699
700         /*
701          * If edge-triggered, clear the GPE status bit now. Note that
702          * level-triggered events are cleared after the GPE is serviced.
703          */
704         if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
705             ACPI_GPE_EDGE_TRIGGERED) {
706                 status = acpi_hw_clear_gpe(gpe_event_info);
707                 if (ACPI_FAILURE(status)) {
708                         ACPI_EXCEPTION((AE_INFO, status,
709                                         "Unable to clear GPE%02X", gpe_number));
710                         return_VALUE(ACPI_INTERRUPT_NOT_HANDLED);
711                 }
712         }
713
714         /*
715          * Always disable the GPE so that it does not keep firing before
716          * any asynchronous activity completes (either from the execution
717          * of a GPE method or an asynchronous GPE handler.)
718          *
719          * If there is no handler or method to run, just disable the
720          * GPE and leave it disabled permanently to prevent further such
721          * pointless events from firing.
722          */
723         status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
724         if (ACPI_FAILURE(status)) {
725                 ACPI_EXCEPTION((AE_INFO, status,
726                                 "Unable to disable GPE%02X", gpe_number));
727                 return_VALUE(ACPI_INTERRUPT_NOT_HANDLED);
728         }
729
730         /*
731          * Dispatch the GPE to either an installed handler or the control
732          * method associated with this GPE (_Lxx or _Exx). If a handler
733          * exists, we invoke it and do not attempt to run the method.
734          * If there is neither a handler nor a method, leave the GPE
735          * disabled.
736          */
737         switch (gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) {
738         case ACPI_GPE_DISPATCH_HANDLER:
739
740                 /* Invoke the installed handler (at interrupt level) */
741
742                 return_value =
743                     gpe_event_info->dispatch.handler->address(gpe_device,
744                                                               gpe_number,
745                                                               gpe_event_info->
746                                                               dispatch.handler->
747                                                               context);
748
749                 /* If requested, clear (if level-triggered) and reenable the GPE */
750
751                 if (return_value & ACPI_REENABLE_GPE) {
752                         (void)acpi_ev_finish_gpe(gpe_event_info);
753                 }
754                 break;
755
756         case ACPI_GPE_DISPATCH_METHOD:
757         case ACPI_GPE_DISPATCH_NOTIFY:
758
759                 /*
760                  * Execute the method associated with the GPE
761                  * NOTE: Level-triggered GPEs are cleared after the method completes.
762                  */
763                 status = acpi_os_execute(OSL_GPE_HANDLER,
764                                          acpi_ev_asynch_execute_gpe_method,
765                                          gpe_event_info);
766                 if (ACPI_FAILURE(status)) {
767                         ACPI_EXCEPTION((AE_INFO, status,
768                                         "Unable to queue handler for GPE%02X - event disabled",
769                                         gpe_number));
770                 }
771                 break;
772
773         default:
774
775                 /*
776                  * No handler or method to run!
777                  * 03/2010: This case should no longer be possible. We will not allow
778                  * a GPE to be enabled if it has no handler or method.
779                  */
780                 ACPI_ERROR((AE_INFO,
781                             "No handler or method for GPE%02X, disabling event",
782                             gpe_number));
783
784                 break;
785         }
786
787         return_VALUE(ACPI_INTERRUPT_HANDLED);
788 }
789
790 #endif                          /* !ACPI_REDUCED_HARDWARE */