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 a GPE of 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          - Add a reference to this GPE
 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
 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 acpi_ev_remove_gpe_reference(struct acpi_gpe_event_info *gpe_event_info)
 196 {
 197         acpi_status status = AE_OK;
 198
 199         ACPI_FUNCTION_TRACE(ev_remove_gpe_reference);
 200
 201         if (!gpe_event_info->runtime_count) {
 202                 return_ACPI_STATUS(AE_LIMIT);
 203         }
 204
 205         gpe_event_info->runtime_count--;
 206         if (!gpe_event_info->runtime_count) {
 207
 208                 /* Disable on last reference */
 209
 210                 status = acpi_ev_update_gpe_enable_mask(gpe_event_info);
 211                 if (ACPI_SUCCESS(status)) {
 212                         status = acpi_hw_low_set_gpe(gpe_event_info,
 213                                                      ACPI_GPE_DISABLE);
 214                 }
 215
 216                 if (ACPI_FAILURE(status)) {
 217                         gpe_event_info->runtime_count++;
 218                 }
 219         }
 220
 221         return_ACPI_STATUS(status);
 222 }
 223
 224 /*******************************************************************************
 225  *
 226  * FUNCTION:    acpi_ev_low_get_gpe_info
 227  *
 228  * PARAMETERS:  gpe_number          - Raw GPE number
 229  *              gpe_block           - A GPE info block
 230  *
 231  * RETURN:      A GPE event_info struct. NULL if not a valid GPE (The gpe_number
 232  *              is not within the specified GPE block)
 233  *
 234  * DESCRIPTION: Returns the event_info struct associated with this GPE. This is
 235  *              the low-level implementation of ev_get_gpe_event_info.
 236  *
 237  ******************************************************************************/
 238
 239 struct acpi_gpe_event_info *acpi_ev_low_get_gpe_info(u32 gpe_number,
 240                                                      struct acpi_gpe_block_info
 241                                                      *gpe_block)
 242 {
 243         u32 gpe_index;
 244
 245         /*
 246          * Validate that the gpe_number is within the specified gpe_block.
 247          * (Two steps)
 248          */
 249         if (!gpe_block || (gpe_number < gpe_block->block_base_number)) {
 250                 return (NULL);
 251         }
 252
 253         gpe_index = gpe_number - gpe_block->block_base_number;
 254         if (gpe_index >= gpe_block->gpe_count) {
 255                 return (NULL);
 256         }
 257
 258         return (&gpe_block->event_info[gpe_index]);
 259 }
 260
 261
 262 /*******************************************************************************
 263  *
 264  * FUNCTION:    acpi_ev_get_gpe_event_info
 265  *
 266  * PARAMETERS:  gpe_device          - Device node. NULL for GPE0/GPE1
 267  *              gpe_number          - Raw GPE number
 268  *
 269  * RETURN:      A GPE event_info struct. NULL if not a valid GPE
 270  *
 271  * DESCRIPTION: Returns the event_info struct associated with this GPE.
 272  *              Validates the gpe_block and the gpe_number
 273  *
 274  *              Should be called only when the GPE lists are semaphore locked
 275  *              and not subject to change.
 276  *
 277  ******************************************************************************/
 278
 279 struct acpi_gpe_event_info *acpi_ev_get_gpe_event_info(acpi_handle gpe_device,
 280                                                        u32 gpe_number)
 281 {
 282         union acpi_operand_object *obj_desc;
 283         struct acpi_gpe_event_info *gpe_info;
 284         u32 i;
 285
 286         ACPI_FUNCTION_ENTRY();
 287
 288         /* A NULL gpe_device means use the FADT-defined GPE block(s) */
 289
 290         if (!gpe_device) {
 291
 292                 /* Examine GPE Block 0 and 1 (These blocks are permanent) */
 293
 294                 for (i = 0; i < ACPI_MAX_GPE_BLOCKS; i++) {
 295                         gpe_info = acpi_ev_low_get_gpe_info(gpe_number,
 296                                                             acpi_gbl_gpe_fadt_blocks
 297                                                             [i]);
 298                         if (gpe_info) {
 299                                 return (gpe_info);
 300                         }
 301                 }
 302
 303                 /* The gpe_number was not in the range of either FADT GPE block */
 304
 305                 return (NULL);
 306         }
 307
 308         /* A Non-NULL gpe_device means this is a GPE Block Device */
 309
 310         obj_desc = acpi_ns_get_attached_object((struct acpi_namespace_node *)
 311                                                gpe_device);
 312         if (!obj_desc || !obj_desc->device.gpe_block) {
 313                 return (NULL);
 314         }
 315
 316         return (acpi_ev_low_get_gpe_info
 317                 (gpe_number, obj_desc->device.gpe_block));
 318 }
 319
 320 /*******************************************************************************
 321  *
 322  * FUNCTION:    acpi_ev_gpe_detect
 323  *
 324  * PARAMETERS:  gpe_xrupt_list      - Interrupt block for this interrupt.
 325  *                                    Can have multiple GPE blocks attached.
 326  *
 327  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
 328  *
 329  * DESCRIPTION: Detect if any GP events have occurred. This function is
 330  *              executed at interrupt level.
 331  *
 332  ******************************************************************************/
 333
 334 u32 acpi_ev_gpe_detect(struct acpi_gpe_xrupt_info * gpe_xrupt_list)
 335 {
 336         acpi_status status;
 337         struct acpi_gpe_block_info *gpe_block;
 338         struct acpi_gpe_register_info *gpe_register_info;
 339         u32 int_status = ACPI_INTERRUPT_NOT_HANDLED;
 340         u8 enabled_status_byte;
 341         u32 status_reg;
 342         u32 enable_reg;
 343         acpi_cpu_flags flags;
 344         u32 i;
 345         u32 j;
 346
 347         ACPI_FUNCTION_NAME(ev_gpe_detect);
 348
 349         /* Check for the case where there are no GPEs */
 350
 351         if (!gpe_xrupt_list) {
 352                 return (int_status);
 353         }
 354
 355         /*
 356          * We need to obtain the GPE lock for both the data structs and registers
 357          * Note: Not necessary to obtain the hardware lock, since the GPE
 358          * registers are owned by the gpe_lock.
 359          */
 360         flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
 361
 362         /* Examine all GPE blocks attached to this interrupt level */
 363
 364         gpe_block = gpe_xrupt_list->gpe_block_list_head;
 365         while (gpe_block) {
 366                 /*
 367                  * Read all of the 8-bit GPE status and enable registers in this GPE
 368                  * block, saving all of them. Find all currently active GP events.
 369                  */
 370                 for (i = 0; i < gpe_block->register_count; i++) {
 371
 372                         /* Get the next status/enable pair */
 373
 374                         gpe_register_info = &gpe_block->register_info[i];
 375
 376                         /* Read the Status Register */
 377
 378                         status =
 379                             acpi_hw_read(&status_reg,
 380                                          &gpe_register_info->status_address);
 381                         if (ACPI_FAILURE(status)) {
 382                                 goto unlock_and_exit;
 383                         }
 384
 385                         /* Read the Enable Register */
 386
 387                         status =
 388                             acpi_hw_read(&enable_reg,
 389                                          &gpe_register_info->enable_address);
 390                         if (ACPI_FAILURE(status)) {
 391                                 goto unlock_and_exit;
 392                         }
 393
 394                         ACPI_DEBUG_PRINT((ACPI_DB_INTERRUPTS,
 395                                           "Read GPE Register at GPE%02X: Status=%02X, Enable=%02X\n",
 396                                           gpe_register_info->base_gpe_number,
 397                                           status_reg, enable_reg));
 398
 399                         /* Check if there is anything active at all in this register */
 400
 401                         enabled_status_byte = (u8) (status_reg & enable_reg);
 402                         if (!enabled_status_byte) {
 403
 404                                 /* No active GPEs in this register, move on */
 405
 406                                 continue;
 407                         }
 408
 409                         /* Now look at the individual GPEs in this byte register */
 410
 411                         for (j = 0; j < ACPI_GPE_REGISTER_WIDTH; j++) {
 412
 413                                 /* Examine one GPE bit */
 414
 415                                 if (enabled_status_byte & (1 << j)) {
 416                                         /*
 417                                          * Found an active GPE. Dispatch the event to a handler
 418                                          * or method.
 419                                          */
 420                                         int_status |=
 421                                             acpi_ev_gpe_dispatch(gpe_block->
 422                                                                  node,
 423                                                                  &gpe_block->
 424                                                 event_info[((acpi_size) i * ACPI_GPE_REGISTER_WIDTH) + j], j + gpe_register_info->base_gpe_number);
 425                                 }
 426                         }
 427                 }
 428
 429                 gpe_block = gpe_block->next;
 430         }
 431
 432       unlock_and_exit:
 433
 434         acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 435         return (int_status);
 436 }
 437
 438 /*******************************************************************************
 439  *
 440  * FUNCTION:    acpi_ev_asynch_execute_gpe_method
 441  *
 442  * PARAMETERS:  Context (gpe_event_info) - Info for this GPE
 443  *
 444  * RETURN:      None
 445  *
 446  * DESCRIPTION: Perform the actual execution of a GPE control method. This
 447  *              function is called from an invocation of acpi_os_execute and
 448  *              therefore does NOT execute at interrupt level - so that
 449  *              the control method itself is not executed in the context of
 450  *              an interrupt handler.
 451  *
 452  ******************************************************************************/
 453
 454 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
 455 {
 456         struct acpi_gpe_event_info *gpe_event_info = context;
 457         acpi_status status;
 458         struct acpi_gpe_event_info *local_gpe_event_info;
 459         struct acpi_evaluate_info *info;
 460
 461         ACPI_FUNCTION_TRACE(ev_asynch_execute_gpe_method);
 462
 463         /* Allocate a local GPE block */
 464
 465         local_gpe_event_info =
 466             ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_gpe_event_info));
 467         if (!local_gpe_event_info) {
 468                 ACPI_EXCEPTION((AE_INFO, AE_NO_MEMORY, "while handling a GPE"));
 469                 return_VOID;
 470         }
 471
 472         status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
 473         if (ACPI_FAILURE(status)) {
 474                 ACPI_FREE(local_gpe_event_info);
 475                 return_VOID;
 476         }
 477
 478         /* Must revalidate the gpe_number/gpe_block */
 479
 480         if (!acpi_ev_valid_gpe_event(gpe_event_info)) {
 481                 status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 482                 ACPI_FREE(local_gpe_event_info);
 483                 return_VOID;
 484         }
 485
 486         /*
 487          * Take a snapshot of the GPE info for this level - we copy the info to
 488          * prevent a race condition with remove_handler/remove_block.
 489          */
 490         ACPI_MEMCPY(local_gpe_event_info, gpe_event_info,
 491                     sizeof(struct acpi_gpe_event_info));
 492
 493         status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 494         if (ACPI_FAILURE(status)) {
 495                 return_VOID;
 496         }
 497
 498         /* Do the correct dispatch - normal method or implicit notify */
 499
 500         switch (local_gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) {
 501         case ACPI_GPE_DISPATCH_NOTIFY:
 502
 503                 /*
 504                  * Implicit notify.
 505                  * Dispatch a DEVICE_WAKE notify to the appropriate handler.
 506                  * NOTE: the request is queued for execution after this method
 507                  * completes. The notify handlers are NOT invoked synchronously
 508                  * from this thread -- because handlers may in turn run other
 509                  * control methods.
 510                  */
 511                 status =
 512                     acpi_ev_queue_notify_request(local_gpe_event_info->dispatch.
 513                                                  device_node,
 514                                                  ACPI_NOTIFY_DEVICE_WAKE);
 515                 break;
 516
 517         case ACPI_GPE_DISPATCH_METHOD:
 518
 519                 /* Allocate the evaluation information block */
 520
 521                 info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
 522                 if (!info) {
 523                         status = AE_NO_MEMORY;
 524                 } else {
 525                         /*
 526                          * Invoke the GPE Method (_Lxx, _Exx) i.e., evaluate the _Lxx/_Exx
 527                          * control method that corresponds to this GPE
 528                          */
 529                         info->prefix_node =
 530                             local_gpe_event_info->dispatch.method_node;
 531                         info->flags = ACPI_IGNORE_RETURN_VALUE;
 532
 533                         status = acpi_ns_evaluate(info);
 534                         ACPI_FREE(info);
 535                 }
 536
 537                 if (ACPI_FAILURE(status)) {
 538                         ACPI_EXCEPTION((AE_INFO, status,
 539                                         "while evaluating GPE method [%4.4s]",
 540                                         acpi_ut_get_node_name
 541                                         (local_gpe_event_info->dispatch.
 542                                          method_node)));
 543                 }
 544
 545                 break;
 546
 547         default:
 548                 return_VOID;    /* Should never happen */
 549         }
 550
 551         /* Defer enabling of GPE until all notify handlers are done */
 552
 553         status = acpi_os_execute(OSL_NOTIFY_HANDLER,
 554                                  acpi_ev_asynch_enable_gpe,
 555                                  local_gpe_event_info);
 556         if (ACPI_FAILURE(status)) {
 557                 ACPI_FREE(local_gpe_event_info);
 558         }
 559         return_VOID;
 560 }
 561
 562
 563 /*******************************************************************************
 564  *
 565  * FUNCTION:    acpi_ev_asynch_enable_gpe
 566  *
 567  * PARAMETERS:  Context (gpe_event_info) - Info for this GPE
 568  *              Callback from acpi_os_execute
 569  *
 570  * RETURN:      None
 571  *
 572  * DESCRIPTION: Asynchronous clear/enable for GPE. This allows the GPE to
 573  *              complete (i.e., finish execution of Notify)
 574  *
 575  ******************************************************************************/
 576
 577 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_enable_gpe(void *context)
 578 {
 579         struct acpi_gpe_event_info *gpe_event_info = context;
 580
 581         (void)acpi_ev_finish_gpe(gpe_event_info);
 582
 583         ACPI_FREE(gpe_event_info);
 584         return;
 585 }
 586
 587
 588 /*******************************************************************************
 589  *
 590  * FUNCTION:    acpi_ev_finish_gpe
 591  *
 592  * PARAMETERS:  gpe_event_info      - Info for this GPE
 593  *
 594  * RETURN:      Status
 595  *
 596  * DESCRIPTION: Clear/Enable a GPE. Common code that is used after execution
 597  *              of a GPE method or a synchronous or asynchronous GPE handler.
 598  *
 599  ******************************************************************************/
 600
 601 acpi_status acpi_ev_finish_gpe(struct acpi_gpe_event_info *gpe_event_info)
 602 {
 603         acpi_status status;
 604
 605         if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
 606             ACPI_GPE_LEVEL_TRIGGERED) {
 607                 /*
 608                  * GPE is level-triggered, we clear the GPE status bit after
 609                  * handling the event.
 610                  */
 611                 status = acpi_hw_clear_gpe(gpe_event_info);
 612                 if (ACPI_FAILURE(status)) {
 613                         return (status);
 614                 }
 615         }
 616
 617         /*
 618          * Enable this GPE, conditionally. This means that the GPE will
 619          * only be physically enabled if the enable_for_run bit is set
 620          * in the event_info.
 621          */
 622         (void)acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_CONDITIONAL_ENABLE);
 623         return (AE_OK);
 624 }
 625
 626
 627 /*******************************************************************************
 628  *
 629  * FUNCTION:    acpi_ev_gpe_dispatch
 630  *
 631  * PARAMETERS:  gpe_device      - Device node. NULL for GPE0/GPE1
 632  *              gpe_event_info  - Info for this GPE
 633  *              gpe_number      - Number relative to the parent GPE block
 634  *
 635  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
 636  *
 637  * DESCRIPTION: Dispatch a General Purpose Event to either a function (e.g. EC)
 638  *              or method (e.g. _Lxx/_Exx) handler.
 639  *
 640  *              This function executes at interrupt level.
 641  *
 642  ******************************************************************************/
 643
 644 u32
 645 acpi_ev_gpe_dispatch(struct acpi_namespace_node *gpe_device,
 646                     struct acpi_gpe_event_info *gpe_event_info, u32 gpe_number)
 647 {
 648         acpi_status status;
 649         u32 return_value;
 650
 651         ACPI_FUNCTION_TRACE(ev_gpe_dispatch);
 652
 653         /* Invoke global event handler if present */
 654
 655         acpi_gpe_count++;
 656         if (acpi_gbl_global_event_handler) {
 657                 acpi_gbl_global_event_handler(ACPI_EVENT_TYPE_GPE, gpe_device,
 658                                               gpe_number,
 659                                               acpi_gbl_global_event_handler_context);
 660         }
 661
 662         /*
 663          * If edge-triggered, clear the GPE status bit now. Note that
 664          * level-triggered events are cleared after the GPE is serviced.
 665          */
 666         if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
 667             ACPI_GPE_EDGE_TRIGGERED) {
 668                 status = acpi_hw_clear_gpe(gpe_event_info);
 669                 if (ACPI_FAILURE(status)) {
 670                         ACPI_EXCEPTION((AE_INFO, status,
 671                                         "Unable to clear GPE%02X", gpe_number));
 672                         return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
 673                 }
 674         }
 675
 676         /*
 677          * Always disable the GPE so that it does not keep firing before
 678          * any asynchronous activity completes (either from the execution
 679          * of a GPE method or an asynchronous GPE handler.)
 680          *
 681          * If there is no handler or method to run, just disable the
 682          * GPE and leave it disabled permanently to prevent further such
 683          * pointless events from firing.
 684          */
 685         status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
 686         if (ACPI_FAILURE(status)) {
 687                 ACPI_EXCEPTION((AE_INFO, status,
 688                                 "Unable to disable GPE%02X", gpe_number));
 689                 return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
 690         }
 691
 692         /*
 693          * Dispatch the GPE to either an installed handler or the control
 694          * method associated with this GPE (_Lxx or _Exx). If a handler
 695          * exists, we invoke it and do not attempt to run the method.
 696          * If there is neither a handler nor a method, leave the GPE
 697          * disabled.
 698          */
 699         switch (gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) {
 700         case ACPI_GPE_DISPATCH_HANDLER:
 701
 702                 /* Invoke the installed handler (at interrupt level) */
 703
 704                 return_value =
 705                     gpe_event_info->dispatch.handler->address(gpe_device,
 706                                                               gpe_number,
 707                                                               gpe_event_info->
 708                                                               dispatch.handler->
 709                                                               context);
 710
 711                 /* If requested, clear (if level-triggered) and reenable the GPE */
 712
 713                 if (return_value & ACPI_REENABLE_GPE) {
 714                         (void)acpi_ev_finish_gpe(gpe_event_info);
 715                 }
 716                 break;
 717
 718         case ACPI_GPE_DISPATCH_METHOD:
 719         case ACPI_GPE_DISPATCH_NOTIFY:
 720
 721                 /*
 722                  * Execute the method associated with the GPE
 723                  * NOTE: Level-triggered GPEs are cleared after the method completes.
 724                  */
 725                 status = acpi_os_execute(OSL_GPE_HANDLER,
 726                                          acpi_ev_asynch_execute_gpe_method,
 727                                          gpe_event_info);
 728                 if (ACPI_FAILURE(status)) {
 729                         ACPI_EXCEPTION((AE_INFO, status,
 730                                         "Unable to queue handler for GPE%2X - event disabled",
 731                                         gpe_number));
 732                 }
 733                 break;
 734
 735         default:
 736
 737                 /*
 738                  * No handler or method to run!
 739                  * 03/2010: This case should no longer be possible. We will not allow
 740                  * a GPE to be enabled if it has no handler or method.
 741                  */
 742                 ACPI_ERROR((AE_INFO,
 743                             "No handler or method for GPE%02X, disabling event",
 744                             gpe_number));
 745
 746                 break;
 747         }
 748
 749         return_UINT32(ACPI_INTERRUPT_HANDLED);
 750 }