drivers/acpi/acpica/evgpe.c

   1 /******************************************************************************
   2  *
   3  * Module Name: evgpe - General Purpose Event handling and dispatch
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2010, 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
  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                                                 gpe_register_info);
  85
  86         /* Clear the run bit up front */
  87
  88         ACPI_CLEAR_BIT(gpe_register_info->enable_for_run, register_bit);
  89
  90         /* Set the mask bit only if there are references to this GPE */
  91
  92         if (gpe_event_info->runtime_count) {
  93                 ACPI_SET_BIT(gpe_register_info->enable_for_run, (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 the given GPE from stale events and enable it.
 108  *
 109  ******************************************************************************/
 110 acpi_status
 111 acpi_ev_enable_gpe(struct acpi_gpe_event_info *gpe_event_info)
 112 {
 113         acpi_status status;
 114
 115         ACPI_FUNCTION_TRACE(ev_enable_gpe);
 116
 117         /*
 118          * We will only allow a GPE to be enabled if it has either an associated
 119          * method (_Lxx/_Exx) or a handler, or is using the implicit notify
 120          * feature. Otherwise, the GPE will be immediately disabled by
 121          * acpi_ev_gpe_dispatch the first time it fires.
 122          */
 123         if ((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) ==
 124             ACPI_GPE_DISPATCH_NONE) {
 125                 return_ACPI_STATUS(AE_NO_HANDLER);
 126         }
 127
 128         /* Clear the GPE (of stale events) */
 129         status = acpi_hw_clear_gpe(gpe_event_info);
 130         if (ACPI_FAILURE(status)) {
 131                 return_ACPI_STATUS(status);
 132         }
 133
 134         /* Enable the requested GPE */
 135         status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_ENABLE);
 136
 137         return_ACPI_STATUS(status);
 138 }
 139
 140
 141 /*******************************************************************************
 142  *
 143  * FUNCTION:    acpi_ev_add_gpe_reference
 144  *
 145  * PARAMETERS:  gpe_event_info  - GPE to enable
 146  *
 147  * RETURN:      Status
 148  *
 149  * DESCRIPTION: Add a reference to a GPE. On the first reference, the GPE is
 150  *              hardware-enabled.
 151  *
 152  ******************************************************************************/
 153
 154 acpi_status 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                 status = acpi_ev_update_gpe_enable_mask(gpe_event_info);
 167                 if (ACPI_SUCCESS(status)) {
 168                         status = acpi_ev_enable_gpe(gpe_event_info);
 169                 }
 170
 171                 if (ACPI_FAILURE(status)) {
 172                         gpe_event_info->runtime_count--;
 173                 }
 174         }
 175
 176         return_ACPI_STATUS(status);
 177 }
 178
 179 /*******************************************************************************
 180  *
 181  * FUNCTION:    acpi_ev_remove_gpe_reference
 182  *
 183  * PARAMETERS:  gpe_event_info  - GPE to disable
 184  *
 185  * RETURN:      Status
 186  *
 187  * DESCRIPTION: Remove a reference to a GPE. When the last reference is
 188  *              removed, the GPE is hardware-disabled.
 189  *
 190  ******************************************************************************/
 191
 192 acpi_status acpi_ev_remove_gpe_reference(struct acpi_gpe_event_info *gpe_event_info)
 193 {
 194         acpi_status status = AE_OK;
 195
 196         ACPI_FUNCTION_TRACE(ev_remove_gpe_reference);
 197
 198         if (!gpe_event_info->runtime_count) {
 199                 return_ACPI_STATUS(AE_LIMIT);
 200         }
 201
 202         gpe_event_info->runtime_count--;
 203         if (!gpe_event_info->runtime_count) {
 204                 status = acpi_ev_update_gpe_enable_mask(gpe_event_info);
 205                 if (ACPI_SUCCESS(status)) {
 206                         status = acpi_hw_low_set_gpe(gpe_event_info,
 207                                                      ACPI_GPE_DISABLE);
 208                 }
 209
 210                 if (ACPI_FAILURE(status)) {
 211                         gpe_event_info->runtime_count++;
 212                 }
 213         }
 214
 215         return_ACPI_STATUS(status);
 216 }
 217
 218 /*******************************************************************************
 219  *
 220  * FUNCTION:    acpi_ev_low_get_gpe_info
 221  *
 222  * PARAMETERS:  gpe_number          - Raw GPE number
 223  *              gpe_block           - A GPE info block
 224  *
 225  * RETURN:      A GPE event_info struct. NULL if not a valid GPE (The gpe_number
 226  *              is not within the specified GPE block)
 227  *
 228  * DESCRIPTION: Returns the event_info struct associated with this GPE. This is
 229  *              the low-level implementation of ev_get_gpe_event_info.
 230  *
 231  ******************************************************************************/
 232
 233 struct acpi_gpe_event_info *acpi_ev_low_get_gpe_info(u32 gpe_number,
 234                                                      struct acpi_gpe_block_info
 235                                                      *gpe_block)
 236 {
 237         u32 gpe_index;
 238
 239         /*
 240          * Validate that the gpe_number is within the specified gpe_block.
 241          * (Two steps)
 242          */
 243         if (!gpe_block || (gpe_number < gpe_block->block_base_number)) {
 244                 return (NULL);
 245         }
 246
 247         gpe_index = gpe_number - gpe_block->block_base_number;
 248         if (gpe_index >= gpe_block->gpe_count) {
 249                 return (NULL);
 250         }
 251
 252         return (&gpe_block->event_info[gpe_index]);
 253 }
 254
 255
 256 /*******************************************************************************
 257  *
 258  * FUNCTION:    acpi_ev_get_gpe_event_info
 259  *
 260  * PARAMETERS:  gpe_device          - Device node. NULL for GPE0/GPE1
 261  *              gpe_number          - Raw GPE number
 262  *
 263  * RETURN:      A GPE event_info struct. NULL if not a valid GPE
 264  *
 265  * DESCRIPTION: Returns the event_info struct associated with this GPE.
 266  *              Validates the gpe_block and the gpe_number
 267  *
 268  *              Should be called only when the GPE lists are semaphore locked
 269  *              and not subject to change.
 270  *
 271  ******************************************************************************/
 272
 273 struct acpi_gpe_event_info *acpi_ev_get_gpe_event_info(acpi_handle gpe_device,
 274                                                        u32 gpe_number)
 275 {
 276         union acpi_operand_object *obj_desc;
 277         struct acpi_gpe_event_info *gpe_info;
 278         u32 i;
 279
 280         ACPI_FUNCTION_ENTRY();
 281
 282         /* A NULL gpe_device means use the FADT-defined GPE block(s) */
 283
 284         if (!gpe_device) {
 285
 286                 /* Examine GPE Block 0 and 1 (These blocks are permanent) */
 287
 288                 for (i = 0; i < ACPI_MAX_GPE_BLOCKS; i++) {
 289                         gpe_info = acpi_ev_low_get_gpe_info(gpe_number,
 290                                                             acpi_gbl_gpe_fadt_blocks
 291                                                             [i]);
 292                         if (gpe_info) {
 293                                 return (gpe_info);
 294                         }
 295                 }
 296
 297                 /* The gpe_number was not in the range of either FADT GPE block */
 298
 299                 return (NULL);
 300         }
 301
 302         /* A Non-NULL gpe_device means this is a GPE Block Device */
 303
 304         obj_desc = 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_gpe_register_info *gpe_register_info;
 333         u32 int_status = ACPI_INTERRUPT_NOT_HANDLED;
 334         u8 enabled_status_byte;
 335         u32 status_reg;
 336         u32 enable_reg;
 337         acpi_cpu_flags flags;
 338         u32 i;
 339         u32 j;
 340
 341         ACPI_FUNCTION_NAME(ev_gpe_detect);
 342
 343         /* Check for the case where there are no GPEs */
 344
 345         if (!gpe_xrupt_list) {
 346                 return (int_status);
 347         }
 348
 349         /*
 350          * We need to obtain the GPE lock for both the data structs and registers
 351          * Note: Not necessary to obtain the hardware lock, since the GPE
 352          * registers are owned by the gpe_lock.
 353          */
 354         flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
 355
 356         /* Examine all GPE blocks attached to this interrupt level */
 357
 358         gpe_block = gpe_xrupt_list->gpe_block_list_head;
 359         while (gpe_block) {
 360                 /*
 361                  * Read all of the 8-bit GPE status and enable registers in this GPE
 362                  * block, saving all of them. Find all currently active GP events.
 363                  */
 364                 for (i = 0; i < gpe_block->register_count; i++) {
 365
 366                         /* Get the next status/enable pair */
 367
 368                         gpe_register_info = &gpe_block->register_info[i];
 369
 370                         /* Read the Status Register */
 371
 372                         status =
 373                             acpi_hw_read(&status_reg,
 374                                          &gpe_register_info->status_address);
 375                         if (ACPI_FAILURE(status)) {
 376                                 goto unlock_and_exit;
 377                         }
 378
 379                         /* Read the Enable Register */
 380
 381                         status =
 382                             acpi_hw_read(&enable_reg,
 383                                          &gpe_register_info->enable_address);
 384                         if (ACPI_FAILURE(status)) {
 385                                 goto unlock_and_exit;
 386                         }
 387
 388                         ACPI_DEBUG_PRINT((ACPI_DB_INTERRUPTS,
 389                                           "Read GPE Register at GPE%X: Status=%02X, Enable=%02X\n",
 390                                           gpe_register_info->base_gpe_number,
 391                                           status_reg, enable_reg));
 392
 393                         /* Check if there is anything active at all in this register */
 394
 395                         enabled_status_byte = (u8) (status_reg & enable_reg);
 396                         if (!enabled_status_byte) {
 397
 398                                 /* No active GPEs in this register, move on */
 399
 400                                 continue;
 401                         }
 402
 403                         /* Now look at the individual GPEs in this byte register */
 404
 405                         for (j = 0; j < ACPI_GPE_REGISTER_WIDTH; j++) {
 406
 407                                 /* Examine one GPE bit */
 408
 409                                 if (enabled_status_byte & (1 << j)) {
 410                                         /*
 411                                          * Found an active GPE. Dispatch the event to a handler
 412                                          * or method.
 413                                          */
 414                                         int_status |=
 415                                             acpi_ev_gpe_dispatch(gpe_block->
 416                                                                  node,
 417                                                                  &gpe_block->
 418                                                 event_info[((acpi_size) i * ACPI_GPE_REGISTER_WIDTH) + j], j + gpe_register_info->base_gpe_number);
 419                                 }
 420                         }
 421                 }
 422
 423                 gpe_block = gpe_block->next;
 424         }
 425
 426       unlock_and_exit:
 427
 428         acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 429         return (int_status);
 430 }
 431
 432 /*******************************************************************************
 433  *
 434  * FUNCTION:    acpi_ev_asynch_execute_gpe_method
 435  *
 436  * PARAMETERS:  Context (gpe_event_info) - Info for this GPE
 437  *
 438  * RETURN:      None
 439  *
 440  * DESCRIPTION: Perform the actual execution of a GPE control method. This
 441  *              function is called from an invocation of acpi_os_execute and
 442  *              therefore does NOT execute at interrupt level - so that
 443  *              the control method itself is not executed in the context of
 444  *              an interrupt handler.
 445  *
 446  ******************************************************************************/
 447
 448 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
 449 {
 450         struct acpi_gpe_event_info *gpe_event_info = context;
 451         acpi_status status;
 452         struct acpi_gpe_event_info *local_gpe_event_info;
 453         struct acpi_evaluate_info *info;
 454
 455         ACPI_FUNCTION_TRACE(ev_asynch_execute_gpe_method);
 456
 457         /* Allocate a local GPE block */
 458
 459         local_gpe_event_info =
 460             ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_gpe_event_info));
 461         if (!local_gpe_event_info) {
 462                 ACPI_EXCEPTION((AE_INFO, AE_NO_MEMORY, "while handling a GPE"));
 463                 return_VOID;
 464         }
 465
 466         status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
 467         if (ACPI_FAILURE(status)) {
 468                 return_VOID;
 469         }
 470
 471         /* Must revalidate the gpe_number/gpe_block */
 472
 473         if (!acpi_ev_valid_gpe_event(gpe_event_info)) {
 474                 status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 475                 return_VOID;
 476         }
 477
 478         /*
 479          * Take a snapshot of the GPE info for this level - we copy the info to
 480          * prevent a race condition with remove_handler/remove_block.
 481          */
 482         ACPI_MEMCPY(local_gpe_event_info, gpe_event_info,
 483                     sizeof(struct acpi_gpe_event_info));
 484
 485         status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 486         if (ACPI_FAILURE(status)) {
 487                 return_VOID;
 488         }
 489
 490         /* Do the correct dispatch - normal method or implicit notify */
 491
 492         switch (local_gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) {
 493         case ACPI_GPE_DISPATCH_NOTIFY:
 494
 495                 /*
 496                  * Implicit notify.
 497                  * Dispatch a DEVICE_WAKE notify to the appropriate handler.
 498                  * NOTE: the request is queued for execution after this method
 499                  * completes. The notify handlers are NOT invoked synchronously
 500                  * from this thread -- because handlers may in turn run other
 501                  * control methods.
 502                  */
 503                 status =
 504                     acpi_ev_queue_notify_request(local_gpe_event_info->dispatch.
 505                                                  device_node,
 506                                                  ACPI_NOTIFY_DEVICE_WAKE);
 507                 break;
 508
 509         case ACPI_GPE_DISPATCH_METHOD:
 510
 511                 /* Allocate the evaluation information block */
 512
 513                 info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
 514                 if (!info) {
 515                         status = AE_NO_MEMORY;
 516                 } else {
 517                         /*
 518                          * Invoke the GPE Method (_Lxx, _Exx) i.e., evaluate the _Lxx/_Exx
 519                          * control method that corresponds to this GPE
 520                          */
 521                         info->prefix_node =
 522                             local_gpe_event_info->dispatch.method_node;
 523                         info->flags = ACPI_IGNORE_RETURN_VALUE;
 524
 525                         status = acpi_ns_evaluate(info);
 526                         ACPI_FREE(info);
 527                 }
 528
 529                 if (ACPI_FAILURE(status)) {
 530                         ACPI_EXCEPTION((AE_INFO, status,
 531                                         "while evaluating GPE method [%4.4s]",
 532                                         acpi_ut_get_node_name
 533                                         (local_gpe_event_info->dispatch.
 534                                          method_node)));
 535                 }
 536
 537                 break;
 538
 539         default:
 540                 return_VOID;    /* Should never happen */
 541         }
 542
 543         /* Defer enabling of GPE until all notify handlers are done */
 544
 545         status = acpi_os_execute(OSL_NOTIFY_HANDLER,
 546                                  acpi_ev_asynch_enable_gpe,
 547                                  local_gpe_event_info);
 548         if (ACPI_FAILURE(status)) {
 549                 ACPI_FREE(local_gpe_event_info);
 550         }
 551         return_VOID;
 552 }
 553
 554
 555 /*******************************************************************************
 556  *
 557  * FUNCTION:    acpi_ev_asynch_enable_gpe
 558  *
 559  * PARAMETERS:  Context (gpe_event_info) - Info for this GPE
 560  *              Callback from acpi_os_execute
 561  *
 562  * RETURN:      None
 563  *
 564  * DESCRIPTION: Asynchronous clear/enable for GPE. This allows the GPE to
 565  *              complete (i.e., finish execution of Notify)
 566  *
 567  ******************************************************************************/
 568
 569 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_enable_gpe(void *context)
 570 {
 571         struct acpi_gpe_event_info *gpe_event_info = context;
 572
 573         (void)acpi_ev_finish_gpe(gpe_event_info);
 574
 575         ACPI_FREE(gpe_event_info);
 576         return;
 577 }
 578
 579
 580 /*******************************************************************************
 581  *
 582  * FUNCTION:    acpi_ev_finish_gpe
 583  *
 584  * PARAMETERS:  gpe_event_info      - Info for this GPE
 585  *
 586  * RETURN:      Status
 587  *
 588  * DESCRIPTION: Clear/Enable a GPE. Common code that is used after execution
 589  *              of a GPE method or a synchronous or asynchronous GPE handler.
 590  *
 591  ******************************************************************************/
 592
 593 acpi_status acpi_ev_finish_gpe(struct acpi_gpe_event_info *gpe_event_info)
 594 {
 595         acpi_status status;
 596
 597         if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
 598             ACPI_GPE_LEVEL_TRIGGERED) {
 599                 /*
 600                  * GPE is level-triggered, we clear the GPE status bit after
 601                  * handling the event.
 602                  */
 603                 status = acpi_hw_clear_gpe(gpe_event_info);
 604                 if (ACPI_FAILURE(status)) {
 605                         return (status);
 606                 }
 607         }
 608
 609         /*
 610          * Enable this GPE, conditionally. This means that the GPE will
 611          * only be physically enabled if the enable_for_run bit is set
 612          * in the event_info.
 613          */
 614         (void)acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_CONDITIONAL_ENABLE);
 615         return (AE_OK);
 616 }
 617
 618
 619 /*******************************************************************************
 620  *
 621  * FUNCTION:    acpi_ev_gpe_dispatch
 622  *
 623  * PARAMETERS:  gpe_device      - Device node. NULL for GPE0/GPE1
 624  *              gpe_event_info  - Info for this GPE
 625  *              gpe_number      - Number relative to the parent GPE block
 626  *
 627  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
 628  *
 629  * DESCRIPTION: Dispatch a General Purpose Event to either a function (e.g. EC)
 630  *              or method (e.g. _Lxx/_Exx) handler.
 631  *
 632  *              This function executes at interrupt level.
 633  *
 634  ******************************************************************************/
 635
 636 u32
 637 acpi_ev_gpe_dispatch(struct acpi_namespace_node *gpe_device,
 638                     struct acpi_gpe_event_info *gpe_event_info, u32 gpe_number)
 639 {
 640         acpi_status status;
 641         u32 return_value;
 642
 643         ACPI_FUNCTION_TRACE(ev_gpe_dispatch);
 644
 645         /* Invoke global event handler if present */
 646
 647         acpi_gpe_count++;
 648         if (acpi_gbl_global_event_handler) {
 649                 acpi_gbl_global_event_handler(ACPI_EVENT_TYPE_GPE, gpe_device,
 650                                               gpe_number,
 651                                               acpi_gbl_global_event_handler_context);
 652         }
 653
 654         /*
 655          * If edge-triggered, clear the GPE status bit now. Note that
 656          * level-triggered events are cleared after the GPE is serviced.
 657          */
 658         if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
 659             ACPI_GPE_EDGE_TRIGGERED) {
 660                 status = acpi_hw_clear_gpe(gpe_event_info);
 661                 if (ACPI_FAILURE(status)) {
 662                         ACPI_EXCEPTION((AE_INFO, status,
 663                                         "Unable to clear GPE[0x%2X]",
 664                                         gpe_number));
 665                         return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
 666                 }
 667         }
 668
 669         /*
 670          * Always disable the GPE so that it does not keep firing before
 671          * any asynchronous activity completes (either from the execution
 672          * of a GPE method or an asynchronous GPE handler.)
 673          *
 674          * If there is no handler or method to run, just disable the
 675          * GPE and leave it disabled permanently to prevent further such
 676          * pointless events from firing.
 677          */
 678         status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
 679         if (ACPI_FAILURE(status)) {
 680                 ACPI_EXCEPTION((AE_INFO, status,
 681                                 "Unable to disable GPE%02X", gpe_number));
 682                 return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
 683         }
 684
 685         /*
 686          * Dispatch the GPE to either an installed handler or the control
 687          * method associated with this GPE (_Lxx or _Exx). If a handler
 688          * exists, we invoke it and do not attempt to run the method.
 689          * If there is neither a handler nor a method, leave the GPE
 690          * disabled.
 691          */
 692         switch (gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) {
 693         case ACPI_GPE_DISPATCH_HANDLER:
 694
 695                 /* Invoke the installed handler (at interrupt level) */
 696
 697                 return_value =
 698                     gpe_event_info->dispatch.handler->address(gpe_device,
 699                                                               gpe_number,
 700                                                               gpe_event_info->
 701                                                               dispatch.handler->
 702                                                               context);
 703
 704                 /* If requested, clear (if level-triggered) and reenable the GPE */
 705
 706                 if (return_value & ACPI_REENABLE_GPE) {
 707                         (void)acpi_ev_finish_gpe(gpe_event_info);
 708                 }
 709                 break;
 710
 711         case ACPI_GPE_DISPATCH_METHOD:
 712         case ACPI_GPE_DISPATCH_NOTIFY:
 713
 714                 /*
 715                  * Execute the method associated with the GPE
 716                  * NOTE: Level-triggered GPEs are cleared after the method completes.
 717                  */
 718                 status = acpi_os_execute(OSL_GPE_HANDLER,
 719                                          acpi_ev_asynch_execute_gpe_method,
 720                                          gpe_event_info);
 721                 if (ACPI_FAILURE(status)) {
 722                         ACPI_EXCEPTION((AE_INFO, status,
 723                                         "Unable to queue handler for GPE[0x%2X] - event disabled",
 724                                         gpe_number));
 725                 }
 726                 break;
 727
 728         default:
 729
 730                 /*
 731                  * No handler or method to run!
 732                  * 03/2010: This case should no longer be possible. We will not allow
 733                  * a GPE to be enabled if it has no handler or method.
 734                  */
 735                 ACPI_ERROR((AE_INFO,
 736                             "No handler or method for GPE[0x%2X], disabling event",
 737                             gpe_number));
 738
 739                 break;
 740         }
 741
 742         return_UINT32(ACPI_INTERRUPT_HANDLED);
 743 }