drivers/acpi/events/evgpe.c

   1 /******************************************************************************
   2  *
   3  * Module Name: evgpe - General Purpose Event handling and dispatch
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2008, 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 <acpi/acevents.h>
  46 #include <acpi/acnamesp.h>
  47
  48 #define _COMPONENT          ACPI_EVENTS
  49 ACPI_MODULE_NAME("evgpe")
  50
  51 /* Local prototypes */
  52 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context);
  53
  54 /*******************************************************************************
  55  *
  56  * FUNCTION:    acpi_ev_set_gpe_type
  57  *
  58  * PARAMETERS:  gpe_event_info          - GPE to set
  59  *              Type                    - New type
  60  *
  61  * RETURN:      Status
  62  *
  63  * DESCRIPTION: Sets the new type for the GPE (wake, run, or wake/run)
  64  *
  65  ******************************************************************************/
  66
  67 acpi_status
  68 acpi_ev_set_gpe_type(struct acpi_gpe_event_info *gpe_event_info, u8 type)
  69 {
  70         acpi_status status;
  71
  72         ACPI_FUNCTION_TRACE(ev_set_gpe_type);
  73
  74         /* Validate type and update register enable masks */
  75
  76         switch (type) {
  77         case ACPI_GPE_TYPE_WAKE:
  78         case ACPI_GPE_TYPE_RUNTIME:
  79         case ACPI_GPE_TYPE_WAKE_RUN:
  80                 break;
  81
  82         default:
  83                 return_ACPI_STATUS(AE_BAD_PARAMETER);
  84         }
  85
  86         /* Disable the GPE if currently enabled */
  87
  88         status = acpi_ev_disable_gpe(gpe_event_info);
  89
  90         /* Type was validated above */
  91
  92         gpe_event_info->flags &= ~ACPI_GPE_TYPE_MASK;   /* Clear type bits */
  93         gpe_event_info->flags |= type;  /* Insert type */
  94         return_ACPI_STATUS(status);
  95 }
  96
  97 /*******************************************************************************
  98  *
  99  * FUNCTION:    acpi_ev_update_gpe_enable_masks
 100  *
 101  * PARAMETERS:  gpe_event_info          - GPE to update
 102  *              Type                    - What to do: ACPI_GPE_DISABLE or
 103  *                                        ACPI_GPE_ENABLE
 104  *
 105  * RETURN:      Status
 106  *
 107  * DESCRIPTION: Updates GPE register enable masks based on the GPE type
 108  *
 109  ******************************************************************************/
 110
 111 acpi_status
 112 acpi_ev_update_gpe_enable_masks(struct acpi_gpe_event_info *gpe_event_info,
 113                                 u8 type)
 114 {
 115         struct acpi_gpe_register_info *gpe_register_info;
 116         u8 register_bit;
 117
 118         ACPI_FUNCTION_TRACE(ev_update_gpe_enable_masks);
 119
 120         gpe_register_info = gpe_event_info->register_info;
 121         if (!gpe_register_info) {
 122                 return_ACPI_STATUS(AE_NOT_EXIST);
 123         }
 124         register_bit = (u8)
 125             (1 <<
 126              (gpe_event_info->gpe_number - gpe_register_info->base_gpe_number));
 127
 128         /* 1) Disable case.  Simply clear all enable bits */
 129
 130         if (type == ACPI_GPE_DISABLE) {
 131                 ACPI_CLEAR_BIT(gpe_register_info->enable_for_wake,
 132                                register_bit);
 133                 ACPI_CLEAR_BIT(gpe_register_info->enable_for_run, register_bit);
 134                 return_ACPI_STATUS(AE_OK);
 135         }
 136
 137         /* 2) Enable case.  Set/Clear the appropriate enable bits */
 138
 139         switch (gpe_event_info->flags & ACPI_GPE_TYPE_MASK) {
 140         case ACPI_GPE_TYPE_WAKE:
 141                 ACPI_SET_BIT(gpe_register_info->enable_for_wake, register_bit);
 142                 ACPI_CLEAR_BIT(gpe_register_info->enable_for_run, register_bit);
 143                 break;
 144
 145         case ACPI_GPE_TYPE_RUNTIME:
 146                 ACPI_CLEAR_BIT(gpe_register_info->enable_for_wake,
 147                                register_bit);
 148                 ACPI_SET_BIT(gpe_register_info->enable_for_run, register_bit);
 149                 break;
 150
 151         case ACPI_GPE_TYPE_WAKE_RUN:
 152                 ACPI_SET_BIT(gpe_register_info->enable_for_wake, register_bit);
 153                 ACPI_SET_BIT(gpe_register_info->enable_for_run, register_bit);
 154                 break;
 155
 156         default:
 157                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 158         }
 159
 160         return_ACPI_STATUS(AE_OK);
 161 }
 162
 163 /*******************************************************************************
 164  *
 165  * FUNCTION:    acpi_ev_enable_gpe
 166  *
 167  * PARAMETERS:  gpe_event_info          - GPE to enable
 168  *              write_to_hardware       - Enable now, or just mark data structs
 169  *                                        (WAKE GPEs should be deferred)
 170  *
 171  * RETURN:      Status
 172  *
 173  * DESCRIPTION: Enable a GPE based on the GPE type
 174  *
 175  ******************************************************************************/
 176
 177 acpi_status
 178 acpi_ev_enable_gpe(struct acpi_gpe_event_info *gpe_event_info,
 179                    u8 write_to_hardware)
 180 {
 181         acpi_status status;
 182
 183         ACPI_FUNCTION_TRACE(ev_enable_gpe);
 184
 185         /* Make sure HW enable masks are updated */
 186
 187         status =
 188             acpi_ev_update_gpe_enable_masks(gpe_event_info, ACPI_GPE_ENABLE);
 189         if (ACPI_FAILURE(status)) {
 190                 return_ACPI_STATUS(status);
 191         }
 192
 193         /* Mark wake-enabled or HW enable, or both */
 194
 195         switch (gpe_event_info->flags & ACPI_GPE_TYPE_MASK) {
 196         case ACPI_GPE_TYPE_WAKE:
 197
 198                 ACPI_SET_BIT(gpe_event_info->flags, ACPI_GPE_WAKE_ENABLED);
 199                 break;
 200
 201         case ACPI_GPE_TYPE_WAKE_RUN:
 202
 203                 ACPI_SET_BIT(gpe_event_info->flags, ACPI_GPE_WAKE_ENABLED);
 204
 205                 /*lint -fallthrough */
 206
 207         case ACPI_GPE_TYPE_RUNTIME:
 208
 209                 ACPI_SET_BIT(gpe_event_info->flags, ACPI_GPE_RUN_ENABLED);
 210
 211                 if (write_to_hardware) {
 212
 213                         /* Clear the GPE (of stale events), then enable it */
 214
 215                         status = acpi_hw_clear_gpe(gpe_event_info);
 216                         if (ACPI_FAILURE(status)) {
 217                                 return_ACPI_STATUS(status);
 218                         }
 219
 220                         /* Enable the requested runtime GPE */
 221
 222                         status = acpi_hw_write_gpe_enable_reg(gpe_event_info);
 223                 }
 224                 break;
 225
 226         default:
 227                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 228         }
 229
 230         return_ACPI_STATUS(AE_OK);
 231 }
 232
 233 /*******************************************************************************
 234  *
 235  * FUNCTION:    acpi_ev_disable_gpe
 236  *
 237  * PARAMETERS:  gpe_event_info          - GPE to disable
 238  *
 239  * RETURN:      Status
 240  *
 241  * DESCRIPTION: Disable a GPE based on the GPE type
 242  *
 243  ******************************************************************************/
 244
 245 acpi_status acpi_ev_disable_gpe(struct acpi_gpe_event_info *gpe_event_info)
 246 {
 247         acpi_status status;
 248
 249         ACPI_FUNCTION_TRACE(ev_disable_gpe);
 250
 251         /* Make sure HW enable masks are updated */
 252
 253         status =
 254             acpi_ev_update_gpe_enable_masks(gpe_event_info, ACPI_GPE_DISABLE);
 255         if (ACPI_FAILURE(status)) {
 256                 return_ACPI_STATUS(status);
 257         }
 258
 259         /* Clear the appropriate enabled flags for this GPE */
 260
 261         switch (gpe_event_info->flags & ACPI_GPE_TYPE_MASK) {
 262         case ACPI_GPE_TYPE_WAKE:
 263                 ACPI_CLEAR_BIT(gpe_event_info->flags, ACPI_GPE_WAKE_ENABLED);
 264                 break;
 265
 266         case ACPI_GPE_TYPE_WAKE_RUN:
 267                 ACPI_CLEAR_BIT(gpe_event_info->flags, ACPI_GPE_WAKE_ENABLED);
 268
 269                 /* fallthrough */
 270
 271         case ACPI_GPE_TYPE_RUNTIME:
 272
 273                 /* Disable the requested runtime GPE */
 274
 275                 ACPI_CLEAR_BIT(gpe_event_info->flags, ACPI_GPE_RUN_ENABLED);
 276                 break;
 277
 278         default:
 279                 break;
 280         }
 281
 282         /*
 283          * Even if we don't know the GPE type, make sure that we always
 284          * disable it. low_disable_gpe will just clear the enable bit for this
 285          * GPE and write it. It will not write out the current GPE enable mask,
 286          * since this may inadvertently enable GPEs too early, if a rogue GPE has
 287          * come in during ACPICA initialization - possibly as a result of AML or
 288          * other code that has enabled the GPE.
 289          */
 290         status = acpi_hw_low_disable_gpe(gpe_event_info);
 291         return_ACPI_STATUS(status);
 292
 293         return_ACPI_STATUS(AE_OK);
 294 }
 295
 296 /*******************************************************************************
 297  *
 298  * FUNCTION:    acpi_ev_get_gpe_event_info
 299  *
 300  * PARAMETERS:  gpe_device          - Device node.  NULL for GPE0/GPE1
 301  *              gpe_number          - Raw GPE number
 302  *
 303  * RETURN:      A GPE event_info struct. NULL if not a valid GPE
 304  *
 305  * DESCRIPTION: Returns the event_info struct associated with this GPE.
 306  *              Validates the gpe_block and the gpe_number
 307  *
 308  *              Should be called only when the GPE lists are semaphore locked
 309  *              and not subject to change.
 310  *
 311  ******************************************************************************/
 312
 313 struct acpi_gpe_event_info *acpi_ev_get_gpe_event_info(acpi_handle gpe_device,
 314                                                        u32 gpe_number)
 315 {
 316         union acpi_operand_object *obj_desc;
 317         struct acpi_gpe_block_info *gpe_block;
 318         u32 i;
 319
 320         ACPI_FUNCTION_ENTRY();
 321
 322         /* A NULL gpe_block means use the FADT-defined GPE block(s) */
 323
 324         if (!gpe_device) {
 325
 326                 /* Examine GPE Block 0 and 1 (These blocks are permanent) */
 327
 328                 for (i = 0; i < ACPI_MAX_GPE_BLOCKS; i++) {
 329                         gpe_block = acpi_gbl_gpe_fadt_blocks[i];
 330                         if (gpe_block) {
 331                                 if ((gpe_number >= gpe_block->block_base_number)
 332                                     && (gpe_number <
 333                                         gpe_block->block_base_number +
 334                                         (gpe_block->register_count * 8))) {
 335                                         return (&gpe_block->
 336                                                 event_info[gpe_number -
 337                                                            gpe_block->
 338                                                            block_base_number]);
 339                                 }
 340                         }
 341                 }
 342
 343                 /* The gpe_number was not in the range of either FADT GPE block */
 344
 345                 return (NULL);
 346         }
 347
 348         /* A Non-NULL gpe_device means this is a GPE Block Device */
 349
 350         obj_desc = acpi_ns_get_attached_object((struct acpi_namespace_node *)
 351                                                gpe_device);
 352         if (!obj_desc || !obj_desc->device.gpe_block) {
 353                 return (NULL);
 354         }
 355
 356         gpe_block = obj_desc->device.gpe_block;
 357
 358         if ((gpe_number >= gpe_block->block_base_number) &&
 359             (gpe_number <
 360              gpe_block->block_base_number + (gpe_block->register_count * 8))) {
 361                 return (&gpe_block->
 362                         event_info[gpe_number - gpe_block->block_base_number]);
 363         }
 364
 365         return (NULL);
 366 }
 367
 368 /*******************************************************************************
 369  *
 370  * FUNCTION:    acpi_ev_gpe_detect
 371  *
 372  * PARAMETERS:  gpe_xrupt_list      - Interrupt block for this interrupt.
 373  *                                    Can have multiple GPE blocks attached.
 374  *
 375  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
 376  *
 377  * DESCRIPTION: Detect if any GP events have occurred.  This function is
 378  *              executed at interrupt level.
 379  *
 380  ******************************************************************************/
 381
 382 u32 acpi_ev_gpe_detect(struct acpi_gpe_xrupt_info * gpe_xrupt_list)
 383 {
 384         acpi_status status;
 385         struct acpi_gpe_block_info *gpe_block;
 386         struct acpi_gpe_register_info *gpe_register_info;
 387         u32 int_status = ACPI_INTERRUPT_NOT_HANDLED;
 388         u8 enabled_status_byte;
 389         u32 status_reg;
 390         u32 enable_reg;
 391         acpi_cpu_flags flags;
 392         u32 i;
 393         u32 j;
 394
 395         ACPI_FUNCTION_NAME(ev_gpe_detect);
 396
 397         /* Check for the case where there are no GPEs */
 398
 399         if (!gpe_xrupt_list) {
 400                 return (int_status);
 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 registers
 406          * are owned by the gpe_lock.
 407          */
 408         flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
 409
 410         /* Examine all GPE blocks attached to this interrupt level */
 411
 412         gpe_block = gpe_xrupt_list->gpe_block_list_head;
 413         while (gpe_block) {
 414                 /*
 415                  * Read all of the 8-bit GPE status and enable registers
 416                  * in this GPE block, saving all of them.
 417                  * Find all currently active GP events.
 418                  */
 419                 for (i = 0; i < gpe_block->register_count; i++) {
 420
 421                         /* Get the next status/enable pair */
 422
 423                         gpe_register_info = &gpe_block->register_info[i];
 424
 425                         /* Read the Status Register */
 426
 427                         status =
 428                             acpi_hw_low_level_read(ACPI_GPE_REGISTER_WIDTH,
 429                                                    &status_reg,
 430                                                    &gpe_register_info->
 431                                                    status_address);
 432                         if (ACPI_FAILURE(status)) {
 433                                 goto unlock_and_exit;
 434                         }
 435
 436                         /* Read the Enable Register */
 437
 438                         status =
 439                             acpi_hw_low_level_read(ACPI_GPE_REGISTER_WIDTH,
 440                                                    &enable_reg,
 441                                                    &gpe_register_info->
 442                                                    enable_address);
 443                         if (ACPI_FAILURE(status)) {
 444                                 goto unlock_and_exit;
 445                         }
 446
 447                         ACPI_DEBUG_PRINT((ACPI_DB_INTERRUPTS,
 448                                           "Read GPE Register at GPE%X: Status=%02X, Enable=%02X\n",
 449                                           gpe_register_info->base_gpe_number,
 450                                           status_reg, enable_reg));
 451
 452                         /* Check if there is anything active at all in this register */
 453
 454                         enabled_status_byte = (u8) (status_reg & enable_reg);
 455                         if (!enabled_status_byte) {
 456
 457                                 /* No active GPEs in this register, move on */
 458
 459                                 continue;
 460                         }
 461
 462                         /* Now look at the individual GPEs in this byte register */
 463
 464                         for (j = 0; j < ACPI_GPE_REGISTER_WIDTH; j++) {
 465
 466                                 /* Examine one GPE bit */
 467
 468                                 if (enabled_status_byte & (1 << j)) {
 469                                         /*
 470                                          * Found an active GPE. Dispatch the event to a handler
 471                                          * or method.
 472                                          */
 473                                         int_status |=
 474                                             acpi_ev_gpe_dispatch(&gpe_block->
 475                                                 event_info[((acpi_size) i * ACPI_GPE_REGISTER_WIDTH) + j], j + gpe_register_info->base_gpe_number);
 476                                 }
 477                         }
 478                 }
 479
 480                 gpe_block = gpe_block->next;
 481         }
 482
 483       unlock_and_exit:
 484
 485         acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 486         return (int_status);
 487 }
 488
 489 /*******************************************************************************
 490  *
 491  * FUNCTION:    acpi_ev_asynch_execute_gpe_method
 492  *
 493  * PARAMETERS:  Context (gpe_event_info) - Info for this GPE
 494  *
 495  * RETURN:      None
 496  *
 497  * DESCRIPTION: Perform the actual execution of a GPE control method. This
 498  *              function is called from an invocation of acpi_os_execute and
 499  *              therefore does NOT execute at interrupt level - so that
 500  *              the control method itself is not executed in the context of
 501  *              an interrupt handler.
 502  *
 503  ******************************************************************************/
 504 static void acpi_ev_asynch_enable_gpe(void *context);
 505
 506 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
 507 {
 508         struct acpi_gpe_event_info *gpe_event_info = (void *)context;
 509         acpi_status status;
 510         struct acpi_gpe_event_info local_gpe_event_info;
 511         struct acpi_evaluate_info *info;
 512
 513         ACPI_FUNCTION_TRACE(ev_asynch_execute_gpe_method);
 514
 515         status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
 516         if (ACPI_FAILURE(status)) {
 517                 return_VOID;
 518         }
 519
 520         /* Must revalidate the gpe_number/gpe_block */
 521
 522         if (!acpi_ev_valid_gpe_event(gpe_event_info)) {
 523                 status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 524                 return_VOID;
 525         }
 526
 527         /* Set the GPE flags for return to enabled state */
 528
 529         (void)acpi_ev_enable_gpe(gpe_event_info, FALSE);
 530
 531         /*
 532          * Take a snapshot of the GPE info for this level - we copy the
 533          * info to prevent a race condition with remove_handler/remove_block.
 534          */
 535         ACPI_MEMCPY(&local_gpe_event_info, gpe_event_info,
 536                     sizeof(struct acpi_gpe_event_info));
 537
 538         status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 539         if (ACPI_FAILURE(status)) {
 540                 return_VOID;
 541         }
 542
 543         /*
 544          * Must check for control method type dispatch one more
 545          * time to avoid race with ev_gpe_install_handler
 546          */
 547         if ((local_gpe_event_info.flags & ACPI_GPE_DISPATCH_MASK) ==
 548             ACPI_GPE_DISPATCH_METHOD) {
 549
 550                 /* Allocate the evaluation information block */
 551
 552                 info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
 553                 if (!info) {
 554                         status = AE_NO_MEMORY;
 555                 } else {
 556                         /*
 557                          * Invoke the GPE Method (_Lxx, _Exx) i.e., evaluate the _Lxx/_Exx
 558                          * control method that corresponds to this GPE
 559                          */
 560                         info->prefix_node =
 561                             local_gpe_event_info.dispatch.method_node;
 562                         info->flags = ACPI_IGNORE_RETURN_VALUE;
 563
 564                         status = acpi_ns_evaluate(info);
 565                         ACPI_FREE(info);
 566                 }
 567
 568                 if (ACPI_FAILURE(status)) {
 569                         ACPI_EXCEPTION((AE_INFO, status,
 570                                         "while evaluating GPE method [%4.4s]",
 571                                         acpi_ut_get_node_name
 572                                         (local_gpe_event_info.dispatch.
 573                                          method_node)));
 574                 }
 575         }
 576         /* Defer enabling of GPE until all notify handlers are done */
 577         acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_ev_asynch_enable_gpe,
 578                                 gpe_event_info);
 579         return_VOID;
 580 }
 581
 582 static void acpi_ev_asynch_enable_gpe(void *context)
 583 {
 584         struct acpi_gpe_event_info *gpe_event_info = context;
 585         acpi_status status;
 586         if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
 587             ACPI_GPE_LEVEL_TRIGGERED) {
 588                 /*
 589                  * GPE is level-triggered, we clear the GPE status bit after
 590                  * handling the event.
 591                  */
 592                 status = acpi_hw_clear_gpe(gpe_event_info);
 593                 if (ACPI_FAILURE(status)) {
 594                         return_VOID;
 595                 }
 596         }
 597
 598         /* Enable this GPE */
 599         (void)acpi_hw_write_gpe_enable_reg(gpe_event_info);
 600         return_VOID;
 601 }
 602
 603 /*******************************************************************************
 604  *
 605  * FUNCTION:    acpi_ev_gpe_dispatch
 606  *
 607  * PARAMETERS:  gpe_event_info  - Info for this GPE
 608  *              gpe_number      - Number relative to the parent GPE block
 609  *
 610  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
 611  *
 612  * DESCRIPTION: Dispatch a General Purpose Event to either a function (e.g. EC)
 613  *              or method (e.g. _Lxx/_Exx) handler.
 614  *
 615  *              This function executes at interrupt level.
 616  *
 617  ******************************************************************************/
 618
 619 u32
 620 acpi_ev_gpe_dispatch(struct acpi_gpe_event_info *gpe_event_info, u32 gpe_number)
 621 {
 622         acpi_status status;
 623
 624         ACPI_FUNCTION_TRACE(ev_gpe_dispatch);
 625
 626         acpi_os_gpe_count(gpe_number);
 627
 628         /*
 629          * If edge-triggered, clear the GPE status bit now.  Note that
 630          * level-triggered events are cleared after the GPE is serviced.
 631          */
 632         if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
 633             ACPI_GPE_EDGE_TRIGGERED) {
 634                 status = acpi_hw_clear_gpe(gpe_event_info);
 635                 if (ACPI_FAILURE(status)) {
 636                         ACPI_EXCEPTION((AE_INFO, status,
 637                                         "Unable to clear GPE[%2X]",
 638                                         gpe_number));
 639                         return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
 640                 }
 641         }
 642
 643         /*
 644          * Dispatch the GPE to either an installed handler, or the control method
 645          * associated with this GPE (_Lxx or _Exx). If a handler exists, we invoke
 646          * it and do not attempt to run the method. If there is neither a handler
 647          * nor a method, we disable this GPE to prevent further such pointless
 648          * events from firing.
 649          */
 650         switch (gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) {
 651         case ACPI_GPE_DISPATCH_HANDLER:
 652
 653                 /*
 654                  * Invoke the installed handler (at interrupt level)
 655                  * Ignore return status for now.  TBD: leave GPE disabled on error?
 656                  */
 657                 (void)gpe_event_info->dispatch.handler->address(gpe_event_info->
 658                                                                 dispatch.
 659                                                                 handler->
 660                                                                 context);
 661
 662                 /* It is now safe to clear level-triggered events. */
 663
 664                 if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
 665                     ACPI_GPE_LEVEL_TRIGGERED) {
 666                         status = acpi_hw_clear_gpe(gpe_event_info);
 667                         if (ACPI_FAILURE(status)) {
 668                                 ACPI_EXCEPTION((AE_INFO, status,
 669                                                 "Unable to clear GPE[%2X]",
 670                                                 gpe_number));
 671                                 return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
 672                         }
 673                 }
 674                 break;
 675
 676         case ACPI_GPE_DISPATCH_METHOD:
 677
 678                 /*
 679                  * Disable the GPE, so it doesn't keep firing before the method has a
 680                  * chance to run (it runs asynchronously with interrupts enabled).
 681                  */
 682                 status = acpi_ev_disable_gpe(gpe_event_info);
 683                 if (ACPI_FAILURE(status)) {
 684                         ACPI_EXCEPTION((AE_INFO, status,
 685                                         "Unable to disable GPE[%2X]",
 686                                         gpe_number));
 687                         return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
 688                 }
 689
 690                 /*
 691                  * Execute the method associated with the GPE
 692                  * NOTE: Level-triggered GPEs are cleared after the method completes.
 693                  */
 694                 status = acpi_os_execute(OSL_GPE_HANDLER,
 695                                          acpi_ev_asynch_execute_gpe_method,
 696                                          gpe_event_info);
 697                 if (ACPI_FAILURE(status)) {
 698                         ACPI_EXCEPTION((AE_INFO, status,
 699                                         "Unable to queue handler for GPE[%2X] - event disabled",
 700                                         gpe_number));
 701                 }
 702                 break;
 703
 704         default:
 705
 706                 /* No handler or method to run! */
 707
 708                 ACPI_ERROR((AE_INFO,
 709                             "No handler or method for GPE[%2X], disabling event",
 710                             gpe_number));
 711
 712                 /*
 713                  * Disable the GPE. The GPE will remain disabled until the ACPI
 714                  * Core Subsystem is restarted, or a handler is installed.
 715                  */
 716                 status = acpi_ev_disable_gpe(gpe_event_info);
 717                 if (ACPI_FAILURE(status)) {
 718                         ACPI_EXCEPTION((AE_INFO, status,
 719                                         "Unable to disable GPE[%2X]",
 720                                         gpe_number));
 721                         return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
 722                 }
 723                 break;
 724         }
 725
 726         return_UINT32(ACPI_INTERRUPT_HANDLED);
 727 }