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         /* Clear the GPE status */
  85         status = acpi_hw_clear_gpe(gpe_event_info);
  86         if (ACPI_FAILURE(status))
  87                 return_ACPI_STATUS(status);
  88
  89         /* Enable the requested GPE */
  90         status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_ENABLE);
  91         return_ACPI_STATUS(status);
  92 }
  93
  94 /*******************************************************************************
  95  *
  96  * FUNCTION:    acpi_ev_mask_gpe
  97  *
  98  * PARAMETERS:  gpe_event_info          - GPE to be blocked/unblocked
  99  *              is_masked               - Whether the GPE is masked or not
 100  *
 101  * RETURN:      Status
 102  *
 103  * DESCRIPTION: Unconditionally mask/unmask a GPE during runtime.
 104  *
 105  ******************************************************************************/
 106
 107 acpi_status
 108 acpi_ev_mask_gpe(struct acpi_gpe_event_info *gpe_event_info, u8 is_masked)
 109 {
 110         struct acpi_gpe_register_info *gpe_register_info;
 111         u32 register_bit;
 112
 113         ACPI_FUNCTION_TRACE(ev_mask_gpe);
 114
 115         gpe_register_info = gpe_event_info->register_info;
 116         if (!gpe_register_info) {
 117                 return_ACPI_STATUS(AE_NOT_EXIST);
 118         }
 119
 120         register_bit = acpi_hw_get_gpe_register_bit(gpe_event_info);
 121
 122         /* Perform the action */
 123
 124         if (is_masked) {
 125                 if (register_bit & gpe_register_info->mask_for_run) {
 126                         return_ACPI_STATUS(AE_BAD_PARAMETER);
 127                 }
 128
 129                 (void)acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
 130                 ACPI_SET_BIT(gpe_register_info->mask_for_run, (u8)register_bit);
 131         } else {
 132                 if (!(register_bit & gpe_register_info->mask_for_run)) {
 133                         return_ACPI_STATUS(AE_BAD_PARAMETER);
 134                 }
 135
 136                 ACPI_CLEAR_BIT(gpe_register_info->mask_for_run,
 137                                (u8)register_bit);
 138                 if (gpe_event_info->runtime_count
 139                     && !gpe_event_info->disable_for_dispatch) {
 140                         (void)acpi_hw_low_set_gpe(gpe_event_info,
 141                                                   ACPI_GPE_ENABLE);
 142                 }
 143         }
 144
 145         return_ACPI_STATUS(AE_OK);
 146 }
 147
 148 /*******************************************************************************
 149  *
 150  * FUNCTION:    acpi_ev_add_gpe_reference
 151  *
 152  * PARAMETERS:  gpe_event_info          - Add a reference to this GPE
 153  *
 154  * RETURN:      Status
 155  *
 156  * DESCRIPTION: Add a reference to a GPE. On the first reference, the GPE is
 157  *              hardware-enabled.
 158  *
 159  ******************************************************************************/
 160
 161 acpi_status
 162 acpi_ev_add_gpe_reference(struct acpi_gpe_event_info *gpe_event_info)
 163 {
 164         acpi_status status = AE_OK;
 165
 166         ACPI_FUNCTION_TRACE(ev_add_gpe_reference);
 167
 168         if (gpe_event_info->runtime_count == ACPI_UINT8_MAX) {
 169                 return_ACPI_STATUS(AE_LIMIT);
 170         }
 171
 172         gpe_event_info->runtime_count++;
 173         if (gpe_event_info->runtime_count == 1) {
 174
 175                 /* Enable on first reference */
 176
 177                 status = acpi_ev_update_gpe_enable_mask(gpe_event_info);
 178                 if (ACPI_SUCCESS(status)) {
 179                         status = acpi_ev_enable_gpe(gpe_event_info);
 180                 }
 181
 182                 if (ACPI_FAILURE(status)) {
 183                         gpe_event_info->runtime_count--;
 184                 }
 185         }
 186
 187         return_ACPI_STATUS(status);
 188 }
 189
 190 /*******************************************************************************
 191  *
 192  * FUNCTION:    acpi_ev_remove_gpe_reference
 193  *
 194  * PARAMETERS:  gpe_event_info          - Remove a reference to this GPE
 195  *
 196  * RETURN:      Status
 197  *
 198  * DESCRIPTION: Remove a reference to a GPE. When the last reference is
 199  *              removed, the GPE is hardware-disabled.
 200  *
 201  ******************************************************************************/
 202
 203 acpi_status
 204 acpi_ev_remove_gpe_reference(struct acpi_gpe_event_info *gpe_event_info)
 205 {
 206         acpi_status status = AE_OK;
 207
 208         ACPI_FUNCTION_TRACE(ev_remove_gpe_reference);
 209
 210         if (!gpe_event_info->runtime_count) {
 211                 return_ACPI_STATUS(AE_LIMIT);
 212         }
 213
 214         gpe_event_info->runtime_count--;
 215         if (!gpe_event_info->runtime_count) {
 216
 217                 /* Disable on last reference */
 218
 219                 status = acpi_ev_update_gpe_enable_mask(gpe_event_info);
 220                 if (ACPI_SUCCESS(status)) {
 221                         status =
 222                             acpi_hw_low_set_gpe(gpe_event_info,
 223                                                 ACPI_GPE_DISABLE);
 224                 }
 225
 226                 if (ACPI_FAILURE(status)) {
 227                         gpe_event_info->runtime_count++;
 228                 }
 229         }
 230
 231         return_ACPI_STATUS(status);
 232 }
 233
 234 /*******************************************************************************
 235  *
 236  * FUNCTION:    acpi_ev_low_get_gpe_info
 237  *
 238  * PARAMETERS:  gpe_number          - Raw GPE number
 239  *              gpe_block           - A GPE info block
 240  *
 241  * RETURN:      A GPE event_info struct. NULL if not a valid GPE (The gpe_number
 242  *              is not within the specified GPE block)
 243  *
 244  * DESCRIPTION: Returns the event_info struct associated with this GPE. This is
 245  *              the low-level implementation of ev_get_gpe_event_info.
 246  *
 247  ******************************************************************************/
 248
 249 struct acpi_gpe_event_info *acpi_ev_low_get_gpe_info(u32 gpe_number,
 250                                                      struct acpi_gpe_block_info
 251                                                      *gpe_block)
 252 {
 253         u32 gpe_index;
 254
 255         /*
 256          * Validate that the gpe_number is within the specified gpe_block.
 257          * (Two steps)
 258          */
 259         if (!gpe_block || (gpe_number < gpe_block->block_base_number)) {
 260                 return (NULL);
 261         }
 262
 263         gpe_index = gpe_number - gpe_block->block_base_number;
 264         if (gpe_index >= gpe_block->gpe_count) {
 265                 return (NULL);
 266         }
 267
 268         return (&gpe_block->event_info[gpe_index]);
 269 }
 270
 271
 272 /*******************************************************************************
 273  *
 274  * FUNCTION:    acpi_ev_get_gpe_event_info
 275  *
 276  * PARAMETERS:  gpe_device          - Device node. NULL for GPE0/GPE1
 277  *              gpe_number          - Raw GPE number
 278  *
 279  * RETURN:      A GPE event_info struct. NULL if not a valid GPE
 280  *
 281  * DESCRIPTION: Returns the event_info struct associated with this GPE.
 282  *              Validates the gpe_block and the gpe_number
 283  *
 284  *              Should be called only when the GPE lists are semaphore locked
 285  *              and not subject to change.
 286  *
 287  ******************************************************************************/
 288
 289 struct acpi_gpe_event_info *acpi_ev_get_gpe_event_info(acpi_handle gpe_device,
 290                                                        u32 gpe_number)
 291 {
 292         union acpi_operand_object *obj_desc;
 293         struct acpi_gpe_event_info *gpe_info;
 294         u32 i;
 295
 296         ACPI_FUNCTION_ENTRY();
 297
 298         /* A NULL gpe_device means use the FADT-defined GPE block(s) */
 299
 300         if (!gpe_device) {
 301
 302                 /* Examine GPE Block 0 and 1 (These blocks are permanent) */
 303
 304                 for (i = 0; i < ACPI_MAX_GPE_BLOCKS; i++) {
 305                         gpe_info = acpi_ev_low_get_gpe_info(gpe_number,
 306                                                             acpi_gbl_gpe_fadt_blocks
 307                                                             [i]);
 308                         if (gpe_info) {
 309                                 return (gpe_info);
 310                         }
 311                 }
 312
 313                 /* The gpe_number was not in the range of either FADT GPE block */
 314
 315                 return (NULL);
 316         }
 317
 318         /* A Non-NULL gpe_device means this is a GPE Block Device */
 319
 320         obj_desc =
 321             acpi_ns_get_attached_object((struct acpi_namespace_node *)
 322                                                gpe_device);
 323         if (!obj_desc || !obj_desc->device.gpe_block) {
 324                 return (NULL);
 325         }
 326
 327         return (acpi_ev_low_get_gpe_info
 328                 (gpe_number, obj_desc->device.gpe_block));
 329 }
 330
 331 /*******************************************************************************
 332  *
 333  * FUNCTION:    acpi_ev_gpe_detect
 334  *
 335  * PARAMETERS:  gpe_xrupt_list      - Interrupt block for this interrupt.
 336  *                                    Can have multiple GPE blocks attached.
 337  *
 338  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
 339  *
 340  * DESCRIPTION: Detect if any GP events have occurred. This function is
 341  *              executed at interrupt level.
 342  *
 343  ******************************************************************************/
 344
 345 u32 acpi_ev_gpe_detect(struct acpi_gpe_xrupt_info *gpe_xrupt_list)
 346 {
 347         struct acpi_gpe_block_info *gpe_block;
 348         struct acpi_namespace_node *gpe_device;
 349         struct acpi_gpe_register_info *gpe_register_info;
 350         struct acpi_gpe_event_info *gpe_event_info;
 351         u32 gpe_number;
 352         u32 int_status = ACPI_INTERRUPT_NOT_HANDLED;
 353         acpi_cpu_flags flags;
 354         u32 i;
 355         u32 j;
 356
 357         ACPI_FUNCTION_NAME(ev_gpe_detect);
 358
 359         /* Check for the case where there are no GPEs */
 360
 361         if (!gpe_xrupt_list) {
 362                 return (int_status);
 363         }
 364
 365         /*
 366          * We need to obtain the GPE lock for both the data structs and registers
 367          * Note: Not necessary to obtain the hardware lock, since the GPE
 368          * registers are owned by the gpe_lock.
 369          */
 370         flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
 371
 372         /* Examine all GPE blocks attached to this interrupt level */
 373
 374         gpe_block = gpe_xrupt_list->gpe_block_list_head;
 375         while (gpe_block) {
 376                 gpe_device = gpe_block->node;
 377
 378                 /*
 379                  * Read all of the 8-bit GPE status and enable registers in this GPE
 380                  * block, saving all of them. Find all currently active GP events.
 381                  */
 382                 for (i = 0; i < gpe_block->register_count; i++) {
 383
 384                         /* Get the next status/enable pair */
 385
 386                         gpe_register_info = &gpe_block->register_info[i];
 387
 388                         /*
 389                          * Optimization: If there are no GPEs enabled within this
 390                          * register, we can safely ignore the entire register.
 391                          */
 392                         if (!(gpe_register_info->enable_for_run |
 393                               gpe_register_info->enable_for_wake)) {
 394                                 ACPI_DEBUG_PRINT((ACPI_DB_INTERRUPTS,
 395                                                   "Ignore disabled registers for GPE %02X-%02X: "
 396                                                   "RunEnable=%02X, WakeEnable=%02X\n",
 397                                                   gpe_register_info->
 398                                                   base_gpe_number,
 399                                                   gpe_register_info->
 400                                                   base_gpe_number +
 401                                                   (ACPI_GPE_REGISTER_WIDTH - 1),
 402                                                   gpe_register_info->
 403                                                   enable_for_run,
 404                                                   gpe_register_info->
 405                                                   enable_for_wake));
 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                                 /* Detect and dispatch one GPE bit */
 414
 415                                 gpe_event_info =
 416                                     &gpe_block->
 417                                     event_info[((acpi_size)i *
 418                                                 ACPI_GPE_REGISTER_WIDTH) + j];
 419                                 gpe_number =
 420                                     j + gpe_register_info->base_gpe_number;
 421                                 acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 422                                 int_status |=
 423                                     acpi_ev_detect_gpe(gpe_device,
 424                                                        gpe_event_info,
 425                                                        gpe_number);
 426                                 flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
 427                         }
 428                 }
 429
 430                 gpe_block = gpe_block->next;
 431         }
 432
 433         acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 434         return (int_status);
 435 }
 436
 437 /*******************************************************************************
 438  *
 439  * FUNCTION:    acpi_ev_asynch_execute_gpe_method
 440  *
 441  * PARAMETERS:  Context (gpe_event_info) - Info for this GPE
 442  *
 443  * RETURN:      None
 444  *
 445  * DESCRIPTION: Perform the actual execution of a GPE control method. This
 446  *              function is called from an invocation of acpi_os_execute and
 447  *              therefore does NOT execute at interrupt level - so that
 448  *              the control method itself is not executed in the context of
 449  *              an interrupt handler.
 450  *
 451  ******************************************************************************/
 452
 453 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
 454 {
 455         struct acpi_gpe_event_info *gpe_event_info = context;
 456         acpi_status status = AE_OK;
 457         struct acpi_evaluate_info *info;
 458         struct acpi_gpe_notify_info *notify;
 459
 460         ACPI_FUNCTION_TRACE(ev_asynch_execute_gpe_method);
 461
 462         /* Do the correct dispatch - normal method or implicit notify */
 463
 464         switch (ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags)) {
 465         case ACPI_GPE_DISPATCH_NOTIFY:
 466                 /*
 467                  * Implicit notify.
 468                  * Dispatch a DEVICE_WAKE notify to the appropriate handler.
 469                  * NOTE: the request is queued for execution after this method
 470                  * completes. The notify handlers are NOT invoked synchronously
 471                  * from this thread -- because handlers may in turn run other
 472                  * control methods.
 473                  *
 474                  * June 2012: Expand implicit notify mechanism to support
 475                  * notifies on multiple device objects.
 476                  */
 477                 notify = gpe_event_info->dispatch.notify_list;
 478                 while (ACPI_SUCCESS(status) && notify) {
 479                         status =
 480                             acpi_ev_queue_notify_request(notify->device_node,
 481                                                          ACPI_NOTIFY_DEVICE_WAKE);
 482
 483                         notify = notify->next;
 484                 }
 485
 486                 break;
 487
 488         case ACPI_GPE_DISPATCH_METHOD:
 489
 490                 /* Allocate the evaluation information block */
 491
 492                 info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
 493                 if (!info) {
 494                         status = AE_NO_MEMORY;
 495                 } else {
 496                         /*
 497                          * Invoke the GPE Method (_Lxx, _Exx) i.e., evaluate the
 498                          * _Lxx/_Exx control method that corresponds to this GPE
 499                          */
 500                         info->prefix_node =
 501                             gpe_event_info->dispatch.method_node;
 502                         info->flags = ACPI_IGNORE_RETURN_VALUE;
 503
 504                         status = acpi_ns_evaluate(info);
 505                         ACPI_FREE(info);
 506                 }
 507
 508                 if (ACPI_FAILURE(status)) {
 509                         ACPI_EXCEPTION((AE_INFO, status,
 510                                         "while evaluating GPE method [%4.4s]",
 511                                         acpi_ut_get_node_name(gpe_event_info->
 512                                                               dispatch.
 513                                                               method_node)));
 514                 }
 515                 break;
 516
 517         default:
 518
 519                 goto error_exit;        /* Should never happen */
 520         }
 521
 522         /* Defer enabling of GPE until all notify handlers are done */
 523
 524         status = acpi_os_execute(OSL_NOTIFY_HANDLER,
 525                                  acpi_ev_asynch_enable_gpe, gpe_event_info);
 526         if (ACPI_SUCCESS(status)) {
 527                 return_VOID;
 528         }
 529
 530 error_exit:
 531         acpi_ev_asynch_enable_gpe(gpe_event_info);
 532         return_VOID;
 533 }
 534
 535
 536 /*******************************************************************************
 537  *
 538  * FUNCTION:    acpi_ev_asynch_enable_gpe
 539  *
 540  * PARAMETERS:  Context (gpe_event_info) - Info for this GPE
 541  *              Callback from acpi_os_execute
 542  *
 543  * RETURN:      None
 544  *
 545  * DESCRIPTION: Asynchronous clear/enable for GPE. This allows the GPE to
 546  *              complete (i.e., finish execution of Notify)
 547  *
 548  ******************************************************************************/
 549
 550 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_enable_gpe(void *context)
 551 {
 552         struct acpi_gpe_event_info *gpe_event_info = context;
 553         acpi_cpu_flags flags;
 554
 555         flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
 556         (void)acpi_ev_finish_gpe(gpe_event_info);
 557         acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 558
 559         return;
 560 }
 561
 562
 563 /*******************************************************************************
 564  *
 565  * FUNCTION:    acpi_ev_finish_gpe
 566  *
 567  * PARAMETERS:  gpe_event_info      - Info for this GPE
 568  *
 569  * RETURN:      Status
 570  *
 571  * DESCRIPTION: Clear/Enable a GPE. Common code that is used after execution
 572  *              of a GPE method or a synchronous or asynchronous GPE handler.
 573  *
 574  ******************************************************************************/
 575
 576 acpi_status acpi_ev_finish_gpe(struct acpi_gpe_event_info *gpe_event_info)
 577 {
 578         acpi_status status;
 579
 580         if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
 581             ACPI_GPE_LEVEL_TRIGGERED) {
 582                 /*
 583                  * GPE is level-triggered, we clear the GPE status bit after
 584                  * handling the event.
 585                  */
 586                 status = acpi_hw_clear_gpe(gpe_event_info);
 587                 if (ACPI_FAILURE(status)) {
 588                         return (status);
 589                 }
 590         }
 591
 592         /*
 593          * Enable this GPE, conditionally. This means that the GPE will
 594          * only be physically enabled if the enable_mask bit is set
 595          * in the event_info.
 596          */
 597         (void)acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_CONDITIONAL_ENABLE);
 598         gpe_event_info->disable_for_dispatch = FALSE;
 599         return (AE_OK);
 600 }
 601
 602
 603 /*******************************************************************************
 604  *
 605  * FUNCTION:    acpi_ev_detect_gpe
 606  *
 607  * PARAMETERS:  gpe_device          - Device node. NULL for GPE0/GPE1
 608  *              gpe_event_info      - Info for this GPE
 609  *              gpe_number          - Number relative to the parent GPE block
 610  *
 611  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
 612  *
 613  * DESCRIPTION: Detect and dispatch a General Purpose Event to either a function
 614  *              (e.g. EC) or method (e.g. _Lxx/_Exx) handler.
 615  * NOTE:        GPE is W1C, so it is possible to handle a single GPE from both
 616  *              task and irq context in parallel as long as the process to
 617  *              detect and mask the GPE is atomic.
 618  *              However the atomicity of ACPI_GPE_DISPATCH_RAW_HANDLER is
 619  *              dependent on the raw handler itself.
 620  *
 621  ******************************************************************************/
 622
 623 u32
 624 acpi_ev_detect_gpe(struct acpi_namespace_node *gpe_device,
 625                    struct acpi_gpe_event_info *gpe_event_info, u32 gpe_number)
 626 {
 627         u32 int_status = ACPI_INTERRUPT_NOT_HANDLED;
 628         u8 enabled_status_byte;
 629         u64 status_reg;
 630         u64 enable_reg;
 631         u32 register_bit;
 632         struct acpi_gpe_register_info *gpe_register_info;
 633         struct acpi_gpe_handler_info *gpe_handler_info;
 634         acpi_cpu_flags flags;
 635         acpi_status status;
 636
 637         ACPI_FUNCTION_TRACE(ev_gpe_detect);
 638
 639         flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
 640
 641         if (!gpe_event_info) {
 642                 gpe_event_info = acpi_ev_get_gpe_event_info(gpe_device, gpe_number);
 643                 if (!gpe_event_info)
 644                         goto error_exit;
 645         }
 646
 647         /* Get the info block for the entire GPE register */
 648
 649         gpe_register_info = gpe_event_info->register_info;
 650
 651         /* Get the register bitmask for this GPE */
 652
 653         register_bit = acpi_hw_get_gpe_register_bit(gpe_event_info);
 654
 655         /* GPE currently enabled (enable bit == 1)? */
 656
 657         status = acpi_hw_read(&enable_reg, &gpe_register_info->enable_address);
 658         if (ACPI_FAILURE(status)) {
 659                 goto error_exit;
 660         }
 661
 662         /* GPE currently active (status bit == 1)? */
 663
 664         status = acpi_hw_read(&status_reg, &gpe_register_info->status_address);
 665         if (ACPI_FAILURE(status)) {
 666                 goto error_exit;
 667         }
 668
 669         /* Check if there is anything active at all in this GPE */
 670
 671         ACPI_DEBUG_PRINT((ACPI_DB_INTERRUPTS,
 672                           "Read registers for GPE %02X: Status=%02X, Enable=%02X, "
 673                           "RunEnable=%02X, WakeEnable=%02X\n",
 674                           gpe_number,
 675                           (u32)(status_reg & register_bit),
 676                           (u32)(enable_reg & register_bit),
 677                           gpe_register_info->enable_for_run,
 678                           gpe_register_info->enable_for_wake));
 679
 680         enabled_status_byte = (u8)(status_reg & enable_reg);
 681         if (!(enabled_status_byte & register_bit)) {
 682                 goto error_exit;
 683         }
 684
 685         /* Invoke global event handler if present */
 686
 687         acpi_gpe_count++;
 688         if (acpi_gbl_global_event_handler) {
 689                 acpi_gbl_global_event_handler(ACPI_EVENT_TYPE_GPE,
 690                                               gpe_device, gpe_number,
 691                                               acpi_gbl_global_event_handler_context);
 692         }
 693
 694         /* Found an active GPE */
 695
 696         if (ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags) ==
 697             ACPI_GPE_DISPATCH_RAW_HANDLER) {
 698
 699                 /* Dispatch the event to a raw handler */
 700
 701                 gpe_handler_info = gpe_event_info->dispatch.handler;
 702
 703                 /*
 704                  * There is no protection around the namespace node
 705                  * and the GPE handler to ensure a safe destruction
 706                  * because:
 707                  * 1. The namespace node is expected to always
 708                  *    exist after loading a table.
 709                  * 2. The GPE handler is expected to be flushed by
 710                  *    acpi_os_wait_events_complete() before the
 711                  *    destruction.
 712                  */
 713                 acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 714                 int_status |=
 715                     gpe_handler_info->address(gpe_device, gpe_number,
 716                                               gpe_handler_info->context);
 717                 flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
 718         } else {
 719                 /* Dispatch the event to a standard handler or method. */
 720
 721                 int_status |= acpi_ev_gpe_dispatch(gpe_device,
 722                                                    gpe_event_info, gpe_number);
 723         }
 724
 725 error_exit:
 726         acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 727         return (int_status);
 728 }
 729
 730 /*******************************************************************************
 731  *
 732  * FUNCTION:    acpi_ev_gpe_dispatch
 733  *
 734  * PARAMETERS:  gpe_device          - Device node. NULL for GPE0/GPE1
 735  *              gpe_event_info      - Info for this GPE
 736  *              gpe_number          - Number relative to the parent GPE block
 737  *
 738  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
 739  *
 740  * DESCRIPTION: Dispatch a General Purpose Event to either a function (e.g. EC)
 741  *              or method (e.g. _Lxx/_Exx) handler.
 742  *
 743  ******************************************************************************/
 744
 745 u32
 746 acpi_ev_gpe_dispatch(struct acpi_namespace_node *gpe_device,
 747                      struct acpi_gpe_event_info *gpe_event_info, u32 gpe_number)
 748 {
 749         acpi_status status;
 750         u32 return_value;
 751
 752         ACPI_FUNCTION_TRACE(ev_gpe_dispatch);
 753
 754         /*
 755          * Always disable the GPE so that it does not keep firing before
 756          * any asynchronous activity completes (either from the execution
 757          * of a GPE method or an asynchronous GPE handler.)
 758          *
 759          * If there is no handler or method to run, just disable the
 760          * GPE and leave it disabled permanently to prevent further such
 761          * pointless events from firing.
 762          */
 763         status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
 764         if (ACPI_FAILURE(status)) {
 765                 ACPI_EXCEPTION((AE_INFO, status,
 766                                 "Unable to disable GPE %02X", gpe_number));
 767                 return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
 768         }
 769
 770         /*
 771          * If edge-triggered, clear the GPE status bit now. Note that
 772          * level-triggered events are cleared after the GPE is serviced.
 773          */
 774         if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
 775             ACPI_GPE_EDGE_TRIGGERED) {
 776                 status = acpi_hw_clear_gpe(gpe_event_info);
 777                 if (ACPI_FAILURE(status)) {
 778                         ACPI_EXCEPTION((AE_INFO, status,
 779                                         "Unable to clear GPE %02X",
 780                                         gpe_number));
 781                         (void)acpi_hw_low_set_gpe(gpe_event_info,
 782                                                   ACPI_GPE_CONDITIONAL_ENABLE);
 783                         return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
 784                 }
 785         }
 786
 787         gpe_event_info->disable_for_dispatch = TRUE;
 788
 789         /*
 790          * Dispatch the GPE to either an installed handler or the control
 791          * method associated with this GPE (_Lxx or _Exx). If a handler
 792          * exists, we invoke it and do not attempt to run the method.
 793          * If there is neither a handler nor a method, leave the GPE
 794          * disabled.
 795          */
 796         switch (ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags)) {
 797         case ACPI_GPE_DISPATCH_HANDLER:
 798
 799                 /* Invoke the installed handler (at interrupt level) */
 800
 801                 return_value =
 802                     gpe_event_info->dispatch.handler->address(gpe_device,
 803                                                               gpe_number,
 804                                                               gpe_event_info->
 805                                                               dispatch.handler->
 806                                                               context);
 807
 808                 /* If requested, clear (if level-triggered) and re-enable the GPE */
 809
 810                 if (return_value & ACPI_REENABLE_GPE) {
 811                         (void)acpi_ev_finish_gpe(gpe_event_info);
 812                 }
 813                 break;
 814
 815         case ACPI_GPE_DISPATCH_METHOD:
 816         case ACPI_GPE_DISPATCH_NOTIFY:
 817                 /*
 818                  * Execute the method associated with the GPE
 819                  * NOTE: Level-triggered GPEs are cleared after the method completes.
 820                  */
 821                 status = acpi_os_execute(OSL_GPE_HANDLER,
 822                                          acpi_ev_asynch_execute_gpe_method,
 823                                          gpe_event_info);
 824                 if (ACPI_FAILURE(status)) {
 825                         ACPI_EXCEPTION((AE_INFO, status,
 826                                         "Unable to queue handler for GPE %02X - event disabled",
 827                                         gpe_number));
 828                 }
 829                 break;
 830
 831         default:
 832                 /*
 833                  * No handler or method to run!
 834                  * 03/2010: This case should no longer be possible. We will not allow
 835                  * a GPE to be enabled if it has no handler or method.
 836                  */
 837                 ACPI_ERROR((AE_INFO,
 838                             "No handler or method for GPE %02X, disabling event",
 839                             gpe_number));
 840
 841                 break;
 842         }
 843
 844         return_UINT32(ACPI_INTERRUPT_HANDLED);
 845 }
 846
 847 #endif                          /* !ACPI_REDUCED_HARDWARE */