drivers/acpi/acpica/evgpe.c

   1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
   2 /******************************************************************************
   3  *
   4  * Module Name: evgpe - General Purpose Event handling and dispatch
   5  *
   6  * Copyright (C) 2000 - 2019, Intel Corp.
   7  *
   8  *****************************************************************************/
   9
  10 #include <acpi/acpi.h>
  11 #include "accommon.h"
  12 #include "acevents.h"
  13 #include "acnamesp.h"
  14
  15 #define _COMPONENT          ACPI_EVENTS
  16 ACPI_MODULE_NAME("evgpe")
  17 #if (!ACPI_REDUCED_HARDWARE)    /* Entire module */
  18 /* Local prototypes */
  19 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context);
  20
  21 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_enable_gpe(void *context);
  22
  23 /*******************************************************************************
  24  *
  25  * FUNCTION:    acpi_ev_update_gpe_enable_mask
  26  *
  27  * PARAMETERS:  gpe_event_info          - GPE to update
  28  *
  29  * RETURN:      Status
  30  *
  31  * DESCRIPTION: Updates GPE register enable mask based upon whether there are
  32  *              runtime references to this GPE
  33  *
  34  ******************************************************************************/
  35
  36 acpi_status
  37 acpi_ev_update_gpe_enable_mask(struct acpi_gpe_event_info *gpe_event_info)
  38 {
  39         struct acpi_gpe_register_info *gpe_register_info;
  40         u32 register_bit;
  41
  42         ACPI_FUNCTION_TRACE(ev_update_gpe_enable_mask);
  43
  44         gpe_register_info = gpe_event_info->register_info;
  45         if (!gpe_register_info) {
  46                 return_ACPI_STATUS(AE_NOT_EXIST);
  47         }
  48
  49         register_bit = acpi_hw_get_gpe_register_bit(gpe_event_info);
  50
  51         /* Clear the run bit up front */
  52
  53         ACPI_CLEAR_BIT(gpe_register_info->enable_for_run, register_bit);
  54
  55         /* Set the mask bit only if there are references to this GPE */
  56
  57         if (gpe_event_info->runtime_count) {
  58                 ACPI_SET_BIT(gpe_register_info->enable_for_run,
  59                              (u8)register_bit);
  60         }
  61
  62         gpe_register_info->enable_mask = gpe_register_info->enable_for_run;
  63         return_ACPI_STATUS(AE_OK);
  64 }
  65
  66 /*******************************************************************************
  67  *
  68  * FUNCTION:    acpi_ev_enable_gpe
  69  *
  70  * PARAMETERS:  gpe_event_info          - GPE to enable
  71  *
  72  * RETURN:      Status
  73  *
  74  * DESCRIPTION: Enable a GPE.
  75  *
  76  ******************************************************************************/
  77
  78 acpi_status acpi_ev_enable_gpe(struct acpi_gpe_event_info *gpe_event_info)
  79 {
  80         acpi_status status;
  81
  82         ACPI_FUNCTION_TRACE(ev_enable_gpe);
  83
  84         /* Enable the requested GPE */
  85
  86         status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_ENABLE);
  87         return_ACPI_STATUS(status);
  88 }
  89
  90 /*******************************************************************************
  91  *
  92  * FUNCTION:    acpi_ev_mask_gpe
  93  *
  94  * PARAMETERS:  gpe_event_info          - GPE to be blocked/unblocked
  95  *              is_masked               - Whether the GPE is masked or not
  96  *
  97  * RETURN:      Status
  98  *
  99  * DESCRIPTION: Unconditionally mask/unmask a GPE during runtime.
 100  *
 101  ******************************************************************************/
 102
 103 acpi_status
 104 acpi_ev_mask_gpe(struct acpi_gpe_event_info *gpe_event_info, u8 is_masked)
 105 {
 106         struct acpi_gpe_register_info *gpe_register_info;
 107         u32 register_bit;
 108
 109         ACPI_FUNCTION_TRACE(ev_mask_gpe);
 110
 111         gpe_register_info = gpe_event_info->register_info;
 112         if (!gpe_register_info) {
 113                 return_ACPI_STATUS(AE_NOT_EXIST);
 114         }
 115
 116         register_bit = acpi_hw_get_gpe_register_bit(gpe_event_info);
 117
 118         /* Perform the action */
 119
 120         if (is_masked) {
 121                 if (register_bit & gpe_register_info->mask_for_run) {
 122                         return_ACPI_STATUS(AE_BAD_PARAMETER);
 123                 }
 124
 125                 (void)acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
 126                 ACPI_SET_BIT(gpe_register_info->mask_for_run, (u8)register_bit);
 127         } else {
 128                 if (!(register_bit & gpe_register_info->mask_for_run)) {
 129                         return_ACPI_STATUS(AE_BAD_PARAMETER);
 130                 }
 131
 132                 ACPI_CLEAR_BIT(gpe_register_info->mask_for_run,
 133                                (u8)register_bit);
 134                 if (gpe_event_info->runtime_count
 135                     && !gpe_event_info->disable_for_dispatch) {
 136                         (void)acpi_hw_low_set_gpe(gpe_event_info,
 137                                                   ACPI_GPE_ENABLE);
 138                 }
 139         }
 140
 141         return_ACPI_STATUS(AE_OK);
 142 }
 143
 144 /*******************************************************************************
 145  *
 146  * FUNCTION:    acpi_ev_add_gpe_reference
 147  *
 148  * PARAMETERS:  gpe_event_info          - Add a reference to this GPE
 149  *
 150  * RETURN:      Status
 151  *
 152  * DESCRIPTION: Add a reference to a GPE. On the first reference, the GPE is
 153  *              hardware-enabled.
 154  *
 155  ******************************************************************************/
 156
 157 acpi_status
 158 acpi_ev_add_gpe_reference(struct acpi_gpe_event_info *gpe_event_info)
 159 {
 160         acpi_status status = AE_OK;
 161
 162         ACPI_FUNCTION_TRACE(ev_add_gpe_reference);
 163
 164         if (gpe_event_info->runtime_count == ACPI_UINT8_MAX) {
 165                 return_ACPI_STATUS(AE_LIMIT);
 166         }
 167
 168         gpe_event_info->runtime_count++;
 169         if (gpe_event_info->runtime_count == 1) {
 170
 171                 /* Enable on first reference */
 172
 173                 status = acpi_ev_update_gpe_enable_mask(gpe_event_info);
 174                 if (ACPI_SUCCESS(status)) {
 175                         status = acpi_ev_enable_gpe(gpe_event_info);
 176                 }
 177
 178                 if (ACPI_FAILURE(status)) {
 179                         gpe_event_info->runtime_count--;
 180                 }
 181         }
 182
 183         return_ACPI_STATUS(status);
 184 }
 185
 186 /*******************************************************************************
 187  *
 188  * FUNCTION:    acpi_ev_remove_gpe_reference
 189  *
 190  * PARAMETERS:  gpe_event_info          - Remove a reference to this GPE
 191  *
 192  * RETURN:      Status
 193  *
 194  * DESCRIPTION: Remove a reference to a GPE. When the last reference is
 195  *              removed, the GPE is hardware-disabled.
 196  *
 197  ******************************************************************************/
 198
 199 acpi_status
 200 acpi_ev_remove_gpe_reference(struct acpi_gpe_event_info *gpe_event_info)
 201 {
 202         acpi_status status = AE_OK;
 203
 204         ACPI_FUNCTION_TRACE(ev_remove_gpe_reference);
 205
 206         if (!gpe_event_info->runtime_count) {
 207                 return_ACPI_STATUS(AE_LIMIT);
 208         }
 209
 210         gpe_event_info->runtime_count--;
 211         if (!gpe_event_info->runtime_count) {
 212
 213                 /* Disable on last reference */
 214
 215                 status = acpi_ev_update_gpe_enable_mask(gpe_event_info);
 216                 if (ACPI_SUCCESS(status)) {
 217                         status =
 218                             acpi_hw_low_set_gpe(gpe_event_info,
 219                                                 ACPI_GPE_DISABLE);
 220                 }
 221
 222                 if (ACPI_FAILURE(status)) {
 223                         gpe_event_info->runtime_count++;
 224                 }
 225         }
 226
 227         return_ACPI_STATUS(status);
 228 }
 229
 230 /*******************************************************************************
 231  *
 232  * FUNCTION:    acpi_ev_low_get_gpe_info
 233  *
 234  * PARAMETERS:  gpe_number          - Raw GPE number
 235  *              gpe_block           - A GPE info block
 236  *
 237  * RETURN:      A GPE event_info struct. NULL if not a valid GPE (The gpe_number
 238  *              is not within the specified GPE block)
 239  *
 240  * DESCRIPTION: Returns the event_info struct associated with this GPE. This is
 241  *              the low-level implementation of ev_get_gpe_event_info.
 242  *
 243  ******************************************************************************/
 244
 245 struct acpi_gpe_event_info *acpi_ev_low_get_gpe_info(u32 gpe_number,
 246                                                      struct acpi_gpe_block_info
 247                                                      *gpe_block)
 248 {
 249         u32 gpe_index;
 250
 251         /*
 252          * Validate that the gpe_number is within the specified gpe_block.
 253          * (Two steps)
 254          */
 255         if (!gpe_block || (gpe_number < gpe_block->block_base_number)) {
 256                 return (NULL);
 257         }
 258
 259         gpe_index = gpe_number - gpe_block->block_base_number;
 260         if (gpe_index >= gpe_block->gpe_count) {
 261                 return (NULL);
 262         }
 263
 264         return (&gpe_block->event_info[gpe_index]);
 265 }
 266
 267
 268 /*******************************************************************************
 269  *
 270  * FUNCTION:    acpi_ev_get_gpe_event_info
 271  *
 272  * PARAMETERS:  gpe_device          - Device node. NULL for GPE0/GPE1
 273  *              gpe_number          - Raw GPE number
 274  *
 275  * RETURN:      A GPE event_info struct. NULL if not a valid GPE
 276  *
 277  * DESCRIPTION: Returns the event_info struct associated with this GPE.
 278  *              Validates the gpe_block and the gpe_number
 279  *
 280  *              Should be called only when the GPE lists are semaphore locked
 281  *              and not subject to change.
 282  *
 283  ******************************************************************************/
 284
 285 struct acpi_gpe_event_info *acpi_ev_get_gpe_event_info(acpi_handle gpe_device,
 286                                                        u32 gpe_number)
 287 {
 288         union acpi_operand_object *obj_desc;
 289         struct acpi_gpe_event_info *gpe_info;
 290         u32 i;
 291
 292         ACPI_FUNCTION_ENTRY();
 293
 294         /* A NULL gpe_device means use the FADT-defined GPE block(s) */
 295
 296         if (!gpe_device) {
 297
 298                 /* Examine GPE Block 0 and 1 (These blocks are permanent) */
 299
 300                 for (i = 0; i < ACPI_MAX_GPE_BLOCKS; i++) {
 301                         gpe_info = acpi_ev_low_get_gpe_info(gpe_number,
 302                                                             acpi_gbl_gpe_fadt_blocks
 303                                                             [i]);
 304                         if (gpe_info) {
 305                                 return (gpe_info);
 306                         }
 307                 }
 308
 309                 /* The gpe_number was not in the range of either FADT GPE block */
 310
 311                 return (NULL);
 312         }
 313
 314         /* A Non-NULL gpe_device means this is a GPE Block Device */
 315
 316         obj_desc =
 317             acpi_ns_get_attached_object((struct acpi_namespace_node *)
 318                                                gpe_device);
 319         if (!obj_desc || !obj_desc->device.gpe_block) {
 320                 return (NULL);
 321         }
 322
 323         return (acpi_ev_low_get_gpe_info
 324                 (gpe_number, obj_desc->device.gpe_block));
 325 }
 326
 327 /*******************************************************************************
 328  *
 329  * FUNCTION:    acpi_ev_gpe_detect
 330  *
 331  * PARAMETERS:  gpe_xrupt_list      - Interrupt block for this interrupt.
 332  *                                    Can have multiple GPE blocks attached.
 333  *
 334  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
 335  *
 336  * DESCRIPTION: Detect if any GP events have occurred. This function is
 337  *              executed at interrupt level.
 338  *
 339  ******************************************************************************/
 340
 341 u32 acpi_ev_gpe_detect(struct acpi_gpe_xrupt_info *gpe_xrupt_list)
 342 {
 343         struct acpi_gpe_block_info *gpe_block;
 344         struct acpi_namespace_node *gpe_device;
 345         struct acpi_gpe_register_info *gpe_register_info;
 346         struct acpi_gpe_event_info *gpe_event_info;
 347         u32 gpe_number;
 348         u32 int_status = ACPI_INTERRUPT_NOT_HANDLED;
 349         acpi_cpu_flags flags;
 350         u32 i;
 351         u32 j;
 352
 353         ACPI_FUNCTION_NAME(ev_gpe_detect);
 354
 355         /* Check for the case where there are no GPEs */
 356
 357         if (!gpe_xrupt_list) {
 358                 return (int_status);
 359         }
 360
 361         /*
 362          * We need to obtain the GPE lock for both the data structs and registers
 363          * Note: Not necessary to obtain the hardware lock, since the GPE
 364          * registers are owned by the gpe_lock.
 365          */
 366         flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
 367
 368         /* Examine all GPE blocks attached to this interrupt level */
 369
 370         gpe_block = gpe_xrupt_list->gpe_block_list_head;
 371         while (gpe_block) {
 372                 gpe_device = gpe_block->node;
 373
 374                 /*
 375                  * Read all of the 8-bit GPE status and enable registers in this GPE
 376                  * block, saving all of them. Find all currently active GP events.
 377                  */
 378                 for (i = 0; i < gpe_block->register_count; i++) {
 379
 380                         /* Get the next status/enable pair */
 381
 382                         gpe_register_info = &gpe_block->register_info[i];
 383
 384                         /*
 385                          * Optimization: If there are no GPEs enabled within this
 386                          * register, we can safely ignore the entire register.
 387                          */
 388                         if (!(gpe_register_info->enable_for_run |
 389                               gpe_register_info->enable_for_wake)) {
 390                                 ACPI_DEBUG_PRINT((ACPI_DB_INTERRUPTS,
 391                                                   "Ignore disabled registers for GPE %02X-%02X: "
 392                                                   "RunEnable=%02X, WakeEnable=%02X\n",
 393                                                   gpe_register_info->
 394                                                   base_gpe_number,
 395                                                   gpe_register_info->
 396                                                   base_gpe_number +
 397                                                   (ACPI_GPE_REGISTER_WIDTH - 1),
 398                                                   gpe_register_info->
 399                                                   enable_for_run,
 400                                                   gpe_register_info->
 401                                                   enable_for_wake));
 402                                 continue;
 403                         }
 404
 405                         /* Now look at the individual GPEs in this byte register */
 406
 407                         for (j = 0; j < ACPI_GPE_REGISTER_WIDTH; j++) {
 408
 409                                 /* Detect and dispatch one GPE bit */
 410
 411                                 gpe_event_info =
 412                                     &gpe_block->
 413                                     event_info[((acpi_size)i *
 414                                                 ACPI_GPE_REGISTER_WIDTH) + j];
 415                                 gpe_number =
 416                                     j + gpe_register_info->base_gpe_number;
 417                                 acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 418                                 int_status |=
 419                                     acpi_ev_detect_gpe(gpe_device,
 420                                                        gpe_event_info,
 421                                                        gpe_number);
 422                                 flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
 423                         }
 424                 }
 425
 426                 gpe_block = gpe_block->next;
 427         }
 428
 429         acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 430         return (int_status);
 431 }
 432
 433 /*******************************************************************************
 434  *
 435  * FUNCTION:    acpi_ev_asynch_execute_gpe_method
 436  *
 437  * PARAMETERS:  Context (gpe_event_info) - Info for this GPE
 438  *
 439  * RETURN:      None
 440  *
 441  * DESCRIPTION: Perform the actual execution of a GPE control method. This
 442  *              function is called from an invocation of acpi_os_execute and
 443  *              therefore does NOT execute at interrupt level - so that
 444  *              the control method itself is not executed in the context of
 445  *              an interrupt handler.
 446  *
 447  ******************************************************************************/
 448
 449 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
 450 {
 451         struct acpi_gpe_event_info *gpe_event_info = context;
 452         acpi_status status = AE_OK;
 453         struct acpi_evaluate_info *info;
 454         struct acpi_gpe_notify_info *notify;
 455
 456         ACPI_FUNCTION_TRACE(ev_asynch_execute_gpe_method);
 457
 458         /* Do the correct dispatch - normal method or implicit notify */
 459
 460         switch (ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags)) {
 461         case ACPI_GPE_DISPATCH_NOTIFY:
 462                 /*
 463                  * Implicit notify.
 464                  * Dispatch a DEVICE_WAKE notify to the appropriate handler.
 465                  * NOTE: the request is queued for execution after this method
 466                  * completes. The notify handlers are NOT invoked synchronously
 467                  * from this thread -- because handlers may in turn run other
 468                  * control methods.
 469                  *
 470                  * June 2012: Expand implicit notify mechanism to support
 471                  * notifies on multiple device objects.
 472                  */
 473                 notify = gpe_event_info->dispatch.notify_list;
 474                 while (ACPI_SUCCESS(status) && notify) {
 475                         status =
 476                             acpi_ev_queue_notify_request(notify->device_node,
 477                                                          ACPI_NOTIFY_DEVICE_WAKE);
 478
 479                         notify = notify->next;
 480                 }
 481
 482                 break;
 483
 484         case ACPI_GPE_DISPATCH_METHOD:
 485
 486                 /* Allocate the evaluation information block */
 487
 488                 info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
 489                 if (!info) {
 490                         status = AE_NO_MEMORY;
 491                 } else {
 492                         /*
 493                          * Invoke the GPE Method (_Lxx, _Exx) i.e., evaluate the
 494                          * _Lxx/_Exx control method that corresponds to this GPE
 495                          */
 496                         info->prefix_node =
 497                             gpe_event_info->dispatch.method_node;
 498                         info->flags = ACPI_IGNORE_RETURN_VALUE;
 499
 500                         status = acpi_ns_evaluate(info);
 501                         ACPI_FREE(info);
 502                 }
 503
 504                 if (ACPI_FAILURE(status)) {
 505                         ACPI_EXCEPTION((AE_INFO, status,
 506                                         "while evaluating GPE method [%4.4s]",
 507                                         acpi_ut_get_node_name(gpe_event_info->
 508                                                               dispatch.
 509                                                               method_node)));
 510                 }
 511                 break;
 512
 513         default:
 514
 515                 goto error_exit;        /* Should never happen */
 516         }
 517
 518         /* Defer enabling of GPE until all notify handlers are done */
 519
 520         status = acpi_os_execute(OSL_NOTIFY_HANDLER,
 521                                  acpi_ev_asynch_enable_gpe, gpe_event_info);
 522         if (ACPI_SUCCESS(status)) {
 523                 return_VOID;
 524         }
 525
 526 error_exit:
 527         acpi_ev_asynch_enable_gpe(gpe_event_info);
 528         return_VOID;
 529 }
 530
 531
 532 /*******************************************************************************
 533  *
 534  * FUNCTION:    acpi_ev_asynch_enable_gpe
 535  *
 536  * PARAMETERS:  Context (gpe_event_info) - Info for this GPE
 537  *              Callback from acpi_os_execute
 538  *
 539  * RETURN:      None
 540  *
 541  * DESCRIPTION: Asynchronous clear/enable for GPE. This allows the GPE to
 542  *              complete (i.e., finish execution of Notify)
 543  *
 544  ******************************************************************************/
 545
 546 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_enable_gpe(void *context)
 547 {
 548         struct acpi_gpe_event_info *gpe_event_info = context;
 549         acpi_cpu_flags flags;
 550
 551         flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
 552         (void)acpi_ev_finish_gpe(gpe_event_info);
 553         acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 554
 555         return;
 556 }
 557
 558
 559 /*******************************************************************************
 560  *
 561  * FUNCTION:    acpi_ev_finish_gpe
 562  *
 563  * PARAMETERS:  gpe_event_info      - Info for this GPE
 564  *
 565  * RETURN:      Status
 566  *
 567  * DESCRIPTION: Clear/Enable a GPE. Common code that is used after execution
 568  *              of a GPE method or a synchronous or asynchronous GPE handler.
 569  *
 570  ******************************************************************************/
 571
 572 acpi_status acpi_ev_finish_gpe(struct acpi_gpe_event_info *gpe_event_info)
 573 {
 574         acpi_status status;
 575
 576         if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
 577             ACPI_GPE_LEVEL_TRIGGERED) {
 578                 /*
 579                  * GPE is level-triggered, we clear the GPE status bit after
 580                  * handling the event.
 581                  */
 582                 status = acpi_hw_clear_gpe(gpe_event_info);
 583                 if (ACPI_FAILURE(status)) {
 584                         return (status);
 585                 }
 586         }
 587
 588         /*
 589          * Enable this GPE, conditionally. This means that the GPE will
 590          * only be physically enabled if the enable_mask bit is set
 591          * in the event_info.
 592          */
 593         (void)acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_CONDITIONAL_ENABLE);
 594         gpe_event_info->disable_for_dispatch = FALSE;
 595         return (AE_OK);
 596 }
 597
 598
 599 /*******************************************************************************
 600  *
 601  * FUNCTION:    acpi_ev_detect_gpe
 602  *
 603  * PARAMETERS:  gpe_device          - Device node. NULL for GPE0/GPE1
 604  *              gpe_event_info      - Info for this GPE
 605  *              gpe_number          - Number relative to the parent GPE block
 606  *
 607  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
 608  *
 609  * DESCRIPTION: Detect and dispatch a General Purpose Event to either a function
 610  *              (e.g. EC) or method (e.g. _Lxx/_Exx) handler.
 611  * NOTE:        GPE is W1C, so it is possible to handle a single GPE from both
 612  *              task and irq context in parallel as long as the process to
 613  *              detect and mask the GPE is atomic.
 614  *              However the atomicity of ACPI_GPE_DISPATCH_RAW_HANDLER is
 615  *              dependent on the raw handler itself.
 616  *
 617  ******************************************************************************/
 618
 619 u32
 620 acpi_ev_detect_gpe(struct acpi_namespace_node *gpe_device,
 621                    struct acpi_gpe_event_info *gpe_event_info, u32 gpe_number)
 622 {
 623         u32 int_status = ACPI_INTERRUPT_NOT_HANDLED;
 624         u8 enabled_status_byte;
 625         u64 status_reg;
 626         u64 enable_reg;
 627         u32 register_bit;
 628         struct acpi_gpe_register_info *gpe_register_info;
 629         struct acpi_gpe_handler_info *gpe_handler_info;
 630         acpi_cpu_flags flags;
 631         acpi_status status;
 632
 633         ACPI_FUNCTION_TRACE(ev_gpe_detect);
 634
 635         flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
 636
 637         if (!gpe_event_info) {
 638                 gpe_event_info = acpi_ev_get_gpe_event_info(gpe_device, gpe_number);
 639                 if (!gpe_event_info)
 640                         goto error_exit;
 641         }
 642
 643         /* Get the info block for the entire GPE register */
 644
 645         gpe_register_info = gpe_event_info->register_info;
 646
 647         /* Get the register bitmask for this GPE */
 648
 649         register_bit = acpi_hw_get_gpe_register_bit(gpe_event_info);
 650
 651         /* GPE currently enabled (enable bit == 1)? */
 652
 653         status = acpi_hw_read(&enable_reg, &gpe_register_info->enable_address);
 654         if (ACPI_FAILURE(status)) {
 655                 goto error_exit;
 656         }
 657
 658         /* GPE currently active (status bit == 1)? */
 659
 660         status = acpi_hw_read(&status_reg, &gpe_register_info->status_address);
 661         if (ACPI_FAILURE(status)) {
 662                 goto error_exit;
 663         }
 664
 665         /* Check if there is anything active at all in this GPE */
 666
 667         ACPI_DEBUG_PRINT((ACPI_DB_INTERRUPTS,
 668                           "Read registers for GPE %02X: Status=%02X, Enable=%02X, "
 669                           "RunEnable=%02X, WakeEnable=%02X\n",
 670                           gpe_number,
 671                           (u32)(status_reg & register_bit),
 672                           (u32)(enable_reg & register_bit),
 673                           gpe_register_info->enable_for_run,
 674                           gpe_register_info->enable_for_wake));
 675
 676         enabled_status_byte = (u8)(status_reg & enable_reg);
 677         if (!(enabled_status_byte & register_bit)) {
 678                 goto error_exit;
 679         }
 680
 681         /* Invoke global event handler if present */
 682
 683         acpi_gpe_count++;
 684         if (acpi_gbl_global_event_handler) {
 685                 acpi_gbl_global_event_handler(ACPI_EVENT_TYPE_GPE,
 686                                               gpe_device, gpe_number,
 687                                               acpi_gbl_global_event_handler_context);
 688         }
 689
 690         /* Found an active GPE */
 691
 692         if (ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags) ==
 693             ACPI_GPE_DISPATCH_RAW_HANDLER) {
 694
 695                 /* Dispatch the event to a raw handler */
 696
 697                 gpe_handler_info = gpe_event_info->dispatch.handler;
 698
 699                 /*
 700                  * There is no protection around the namespace node
 701                  * and the GPE handler to ensure a safe destruction
 702                  * because:
 703                  * 1. The namespace node is expected to always
 704                  *    exist after loading a table.
 705                  * 2. The GPE handler is expected to be flushed by
 706                  *    acpi_os_wait_events_complete() before the
 707                  *    destruction.
 708                  */
 709                 acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 710                 int_status |=
 711                     gpe_handler_info->address(gpe_device, gpe_number,
 712                                               gpe_handler_info->context);
 713                 flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
 714         } else {
 715                 /* Dispatch the event to a standard handler or method. */
 716
 717                 int_status |= acpi_ev_gpe_dispatch(gpe_device,
 718                                                    gpe_event_info, gpe_number);
 719         }
 720
 721 error_exit:
 722         acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 723         return (int_status);
 724 }
 725
 726 /*******************************************************************************
 727  *
 728  * FUNCTION:    acpi_ev_gpe_dispatch
 729  *
 730  * PARAMETERS:  gpe_device          - Device node. NULL for GPE0/GPE1
 731  *              gpe_event_info      - Info for this GPE
 732  *              gpe_number          - Number relative to the parent GPE block
 733  *
 734  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
 735  *
 736  * DESCRIPTION: Dispatch a General Purpose Event to either a function (e.g. EC)
 737  *              or method (e.g. _Lxx/_Exx) handler.
 738  *
 739  ******************************************************************************/
 740
 741 u32
 742 acpi_ev_gpe_dispatch(struct acpi_namespace_node *gpe_device,
 743                      struct acpi_gpe_event_info *gpe_event_info, u32 gpe_number)
 744 {
 745         acpi_status status;
 746         u32 return_value;
 747
 748         ACPI_FUNCTION_TRACE(ev_gpe_dispatch);
 749
 750         /*
 751          * Always disable the GPE so that it does not keep firing before
 752          * any asynchronous activity completes (either from the execution
 753          * of a GPE method or an asynchronous GPE handler.)
 754          *
 755          * If there is no handler or method to run, just disable the
 756          * GPE and leave it disabled permanently to prevent further such
 757          * pointless events from firing.
 758          */
 759         status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
 760         if (ACPI_FAILURE(status)) {
 761                 ACPI_EXCEPTION((AE_INFO, status,
 762                                 "Unable to disable GPE %02X", gpe_number));
 763                 return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
 764         }
 765
 766         /*
 767          * If edge-triggered, clear the GPE status bit now. Note that
 768          * level-triggered events are cleared after the GPE is serviced.
 769          */
 770         if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
 771             ACPI_GPE_EDGE_TRIGGERED) {
 772                 status = acpi_hw_clear_gpe(gpe_event_info);
 773                 if (ACPI_FAILURE(status)) {
 774                         ACPI_EXCEPTION((AE_INFO, status,
 775                                         "Unable to clear GPE %02X",
 776                                         gpe_number));
 777                         (void)acpi_hw_low_set_gpe(gpe_event_info,
 778                                                   ACPI_GPE_CONDITIONAL_ENABLE);
 779                         return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
 780                 }
 781         }
 782
 783         gpe_event_info->disable_for_dispatch = TRUE;
 784
 785         /*
 786          * Dispatch the GPE to either an installed handler or the control
 787          * method associated with this GPE (_Lxx or _Exx). If a handler
 788          * exists, we invoke it and do not attempt to run the method.
 789          * If there is neither a handler nor a method, leave the GPE
 790          * disabled.
 791          */
 792         switch (ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags)) {
 793         case ACPI_GPE_DISPATCH_HANDLER:
 794
 795                 /* Invoke the installed handler (at interrupt level) */
 796
 797                 return_value =
 798                     gpe_event_info->dispatch.handler->address(gpe_device,
 799                                                               gpe_number,
 800                                                               gpe_event_info->
 801                                                               dispatch.handler->
 802                                                               context);
 803
 804                 /* If requested, clear (if level-triggered) and re-enable the GPE */
 805
 806                 if (return_value & ACPI_REENABLE_GPE) {
 807                         (void)acpi_ev_finish_gpe(gpe_event_info);
 808                 }
 809                 break;
 810
 811         case ACPI_GPE_DISPATCH_METHOD:
 812         case ACPI_GPE_DISPATCH_NOTIFY:
 813                 /*
 814                  * Execute the method associated with the GPE
 815                  * NOTE: Level-triggered GPEs are cleared after the method completes.
 816                  */
 817                 status = acpi_os_execute(OSL_GPE_HANDLER,
 818                                          acpi_ev_asynch_execute_gpe_method,
 819                                          gpe_event_info);
 820                 if (ACPI_FAILURE(status)) {
 821                         ACPI_EXCEPTION((AE_INFO, status,
 822                                         "Unable to queue handler for GPE %02X - event disabled",
 823                                         gpe_number));
 824                 }
 825                 break;
 826
 827         default:
 828                 /*
 829                  * No handler or method to run!
 830                  * 03/2010: This case should no longer be possible. We will not allow
 831                  * a GPE to be enabled if it has no handler or method.
 832                  */
 833                 ACPI_ERROR((AE_INFO,
 834                             "No handler or method for GPE %02X, disabling event",
 835                             gpe_number));
 836
 837                 break;
 838         }
 839
 840         return_UINT32(ACPI_INTERRUPT_HANDLED);
 841 }
 842
 843 #endif                          /* !ACPI_REDUCED_HARDWARE */