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 - 2013, 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 #if (!ACPI_REDUCED_HARDWARE)    /* Entire module */
  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
  85         /* Clear the run bit up front */
  86
  87         ACPI_CLEAR_BIT(gpe_register_info->enable_for_run, register_bit);
  88
  89         /* Set the mask bit only if there are references to this GPE */
  90
  91         if (gpe_event_info->runtime_count) {
  92                 ACPI_SET_BIT(gpe_register_info->enable_for_run,
  93                              (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 acpi_ev_enable_gpe(struct acpi_gpe_event_info *gpe_event_info)
 111 {
 112         acpi_status status;
 113
 114         ACPI_FUNCTION_TRACE(ev_enable_gpe);
 115
 116         /*
 117          * We will only allow a GPE to be enabled if it has either an associated
 118          * method (_Lxx/_Exx) or a handler, or is using the implicit notify
 119          * feature. Otherwise, the GPE will be immediately disabled by
 120          * acpi_ev_gpe_dispatch the first time it fires.
 121          */
 122         if ((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) ==
 123             ACPI_GPE_DISPATCH_NONE) {
 124                 return_ACPI_STATUS(AE_NO_HANDLER);
 125         }
 126
 127         /* Clear the GPE (of stale events) */
 128         status = acpi_hw_clear_gpe(gpe_event_info);
 129         if (ACPI_FAILURE(status)) {
 130                 return_ACPI_STATUS(status);
 131         }
 132
 133         /* Enable the requested GPE */
 134
 135         status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_ENABLE);
 136         return_ACPI_STATUS(status);
 137 }
 138
 139
 140 /*******************************************************************************
 141  *
 142  * FUNCTION:    acpi_ev_add_gpe_reference
 143  *
 144  * PARAMETERS:  gpe_event_info          - Add a reference to this GPE
 145  *
 146  * RETURN:      Status
 147  *
 148  * DESCRIPTION: Add a reference to a GPE. On the first reference, the GPE is
 149  *              hardware-enabled.
 150  *
 151  ******************************************************************************/
 152
 153 acpi_status
 154 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
 196 acpi_ev_remove_gpe_reference(struct acpi_gpe_event_info *gpe_event_info)
 197 {
 198         acpi_status status = AE_OK;
 199
 200         ACPI_FUNCTION_TRACE(ev_remove_gpe_reference);
 201
 202         if (!gpe_event_info->runtime_count) {
 203                 return_ACPI_STATUS(AE_LIMIT);
 204         }
 205
 206         gpe_event_info->runtime_count--;
 207         if (!gpe_event_info->runtime_count) {
 208
 209                 /* Disable on last reference */
 210
 211                 status = acpi_ev_update_gpe_enable_mask(gpe_event_info);
 212                 if (ACPI_SUCCESS(status)) {
 213                         status =
 214                             acpi_hw_low_set_gpe(gpe_event_info,
 215                                                      ACPI_GPE_DISABLE);
 216                 }
 217
 218                 if (ACPI_FAILURE(status)) {
 219                         gpe_event_info->runtime_count++;
 220                 }
 221         }
 222
 223         return_ACPI_STATUS(status);
 224 }
 225
 226 /*******************************************************************************
 227  *
 228  * FUNCTION:    acpi_ev_low_get_gpe_info
 229  *
 230  * PARAMETERS:  gpe_number          - Raw GPE number
 231  *              gpe_block           - A GPE info block
 232  *
 233  * RETURN:      A GPE event_info struct. NULL if not a valid GPE (The gpe_number
 234  *              is not within the specified GPE block)
 235  *
 236  * DESCRIPTION: Returns the event_info struct associated with this GPE. This is
 237  *              the low-level implementation of ev_get_gpe_event_info.
 238  *
 239  ******************************************************************************/
 240
 241 struct acpi_gpe_event_info *acpi_ev_low_get_gpe_info(u32 gpe_number,
 242                                                      struct acpi_gpe_block_info
 243                                                      *gpe_block)
 244 {
 245         u32 gpe_index;
 246
 247         /*
 248          * Validate that the gpe_number is within the specified gpe_block.
 249          * (Two steps)
 250          */
 251         if (!gpe_block || (gpe_number < gpe_block->block_base_number)) {
 252                 return (NULL);
 253         }
 254
 255         gpe_index = gpe_number - gpe_block->block_base_number;
 256         if (gpe_index >= gpe_block->gpe_count) {
 257                 return (NULL);
 258         }
 259
 260         return (&gpe_block->event_info[gpe_index]);
 261 }
 262
 263
 264 /*******************************************************************************
 265  *
 266  * FUNCTION:    acpi_ev_get_gpe_event_info
 267  *
 268  * PARAMETERS:  gpe_device          - Device node. NULL for GPE0/GPE1
 269  *              gpe_number          - Raw GPE number
 270  *
 271  * RETURN:      A GPE event_info struct. NULL if not a valid GPE
 272  *
 273  * DESCRIPTION: Returns the event_info struct associated with this GPE.
 274  *              Validates the gpe_block and the gpe_number
 275  *
 276  *              Should be called only when the GPE lists are semaphore locked
 277  *              and not subject to change.
 278  *
 279  ******************************************************************************/
 280
 281 struct acpi_gpe_event_info *acpi_ev_get_gpe_event_info(acpi_handle gpe_device,
 282                                                        u32 gpe_number)
 283 {
 284         union acpi_operand_object *obj_desc;
 285         struct acpi_gpe_event_info *gpe_info;
 286         u32 i;
 287
 288         ACPI_FUNCTION_ENTRY();
 289
 290         /* A NULL gpe_device means use the FADT-defined GPE block(s) */
 291
 292         if (!gpe_device) {
 293
 294                 /* Examine GPE Block 0 and 1 (These blocks are permanent) */
 295
 296                 for (i = 0; i < ACPI_MAX_GPE_BLOCKS; i++) {
 297                         gpe_info = acpi_ev_low_get_gpe_info(gpe_number,
 298                                                             acpi_gbl_gpe_fadt_blocks
 299                                                             [i]);
 300                         if (gpe_info) {
 301                                 return (gpe_info);
 302                         }
 303                 }
 304
 305                 /* The gpe_number was not in the range of either FADT GPE block */
 306
 307                 return (NULL);
 308         }
 309
 310         /* A Non-NULL gpe_device means this is a GPE Block Device */
 311
 312         obj_desc =
 313             acpi_ns_get_attached_object((struct acpi_namespace_node *)
 314                                                gpe_device);
 315         if (!obj_desc || !obj_desc->device.gpe_block) {
 316                 return (NULL);
 317         }
 318
 319         return (acpi_ev_low_get_gpe_info
 320                 (gpe_number, obj_desc->device.gpe_block));
 321 }
 322
 323 /*******************************************************************************
 324  *
 325  * FUNCTION:    acpi_ev_gpe_detect
 326  *
 327  * PARAMETERS:  gpe_xrupt_list      - Interrupt block for this interrupt.
 328  *                                    Can have multiple GPE blocks attached.
 329  *
 330  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
 331  *
 332  * DESCRIPTION: Detect if any GP events have occurred. This function is
 333  *              executed at interrupt level.
 334  *
 335  ******************************************************************************/
 336
 337 u32 acpi_ev_gpe_detect(struct acpi_gpe_xrupt_info * gpe_xrupt_list)
 338 {
 339         acpi_status status;
 340         struct acpi_gpe_block_info *gpe_block;
 341         struct acpi_gpe_register_info *gpe_register_info;
 342         u32 int_status = ACPI_INTERRUPT_NOT_HANDLED;
 343         u8 enabled_status_byte;
 344         u32 status_reg;
 345         u32 enable_reg;
 346         acpi_cpu_flags flags;
 347         u32 i;
 348         u32 j;
 349
 350         ACPI_FUNCTION_NAME(ev_gpe_detect);
 351
 352         /* Check for the case where there are no GPEs */
 353
 354         if (!gpe_xrupt_list) {
 355                 return (int_status);
 356         }
 357
 358         /*
 359          * We need to obtain the GPE lock for both the data structs and registers
 360          * Note: Not necessary to obtain the hardware lock, since the GPE
 361          * registers are owned by the gpe_lock.
 362          */
 363         flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
 364
 365         /* Examine all GPE blocks attached to this interrupt level */
 366
 367         gpe_block = gpe_xrupt_list->gpe_block_list_head;
 368         while (gpe_block) {
 369                 /*
 370                  * Read all of the 8-bit GPE status and enable registers in this GPE
 371                  * block, saving all of them. Find all currently active GP events.
 372                  */
 373                 for (i = 0; i < gpe_block->register_count; i++) {
 374
 375                         /* Get the next status/enable pair */
 376
 377                         gpe_register_info = &gpe_block->register_info[i];
 378
 379                         /*
 380                          * Optimization: If there are no GPEs enabled within this
 381                          * register, we can safely ignore the entire register.
 382                          */
 383                         if (!(gpe_register_info->enable_for_run |
 384                               gpe_register_info->enable_for_wake)) {
 385                                 ACPI_DEBUG_PRINT((ACPI_DB_INTERRUPTS,
 386                                                   "Ignore disabled registers for GPE%02X-GPE%02X: "
 387                                                   "RunEnable=%02X, WakeEnable=%02X\n",
 388                                                   gpe_register_info->
 389                                                   base_gpe_number,
 390                                                   gpe_register_info->
 391                                                   base_gpe_number +
 392                                                   (ACPI_GPE_REGISTER_WIDTH - 1),
 393                                                   gpe_register_info->
 394                                                   enable_for_run,
 395                                                   gpe_register_info->
 396                                                   enable_for_wake));
 397                                 continue;
 398                         }
 399
 400                         /* Read the Status Register */
 401
 402                         status =
 403                             acpi_hw_read(&status_reg,
 404                                          &gpe_register_info->status_address);
 405                         if (ACPI_FAILURE(status)) {
 406                                 goto unlock_and_exit;
 407                         }
 408
 409                         /* Read the Enable Register */
 410
 411                         status =
 412                             acpi_hw_read(&enable_reg,
 413                                          &gpe_register_info->enable_address);
 414                         if (ACPI_FAILURE(status)) {
 415                                 goto unlock_and_exit;
 416                         }
 417
 418                         ACPI_DEBUG_PRINT((ACPI_DB_INTERRUPTS,
 419                                           "Read registers for GPE%02X-GPE%02X: Status=%02X, Enable=%02X, "
 420                                           "RunEnable=%02X, WakeEnable=%02X\n",
 421                                           gpe_register_info->base_gpe_number,
 422                                           gpe_register_info->base_gpe_number +
 423                                           (ACPI_GPE_REGISTER_WIDTH - 1),
 424                                           status_reg, enable_reg,
 425                                           gpe_register_info->enable_for_run,
 426                                           gpe_register_info->enable_for_wake));
 427
 428                         /* Check if there is anything active at all in this register */
 429
 430                         enabled_status_byte = (u8) (status_reg & enable_reg);
 431                         if (!enabled_status_byte) {
 432
 433                                 /* No active GPEs in this register, move on */
 434
 435                                 continue;
 436                         }
 437
 438                         /* Now look at the individual GPEs in this byte register */
 439
 440                         for (j = 0; j < ACPI_GPE_REGISTER_WIDTH; j++) {
 441
 442                                 /* Examine one GPE bit */
 443
 444                                 if (enabled_status_byte & (1 << j)) {
 445                                         /*
 446                                          * Found an active GPE. Dispatch the event to a handler
 447                                          * or method.
 448                                          */
 449                                         int_status |=
 450                                             acpi_ev_gpe_dispatch(gpe_block->
 451                                                                  node,
 452                                                                  &gpe_block->
 453                                                 event_info[((acpi_size) i * ACPI_GPE_REGISTER_WIDTH) + j], j + gpe_register_info->base_gpe_number);
 454                                 }
 455                         }
 456                 }
 457
 458                 gpe_block = gpe_block->next;
 459         }
 460
 461       unlock_and_exit:
 462
 463         acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 464         return (int_status);
 465 }
 466
 467 /*******************************************************************************
 468  *
 469  * FUNCTION:    acpi_ev_asynch_execute_gpe_method
 470  *
 471  * PARAMETERS:  Context (gpe_event_info) - Info for this GPE
 472  *
 473  * RETURN:      None
 474  *
 475  * DESCRIPTION: Perform the actual execution of a GPE control method. This
 476  *              function is called from an invocation of acpi_os_execute and
 477  *              therefore does NOT execute at interrupt level - so that
 478  *              the control method itself is not executed in the context of
 479  *              an interrupt handler.
 480  *
 481  ******************************************************************************/
 482
 483 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
 484 {
 485         struct acpi_gpe_event_info *gpe_event_info = context;
 486         acpi_status status;
 487         struct acpi_gpe_event_info *local_gpe_event_info;
 488         struct acpi_evaluate_info *info;
 489         struct acpi_gpe_notify_info *notify;
 490
 491         ACPI_FUNCTION_TRACE(ev_asynch_execute_gpe_method);
 492
 493         /* Allocate a local GPE block */
 494
 495         local_gpe_event_info =
 496             ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_gpe_event_info));
 497         if (!local_gpe_event_info) {
 498                 ACPI_EXCEPTION((AE_INFO, AE_NO_MEMORY, "while handling a GPE"));
 499                 return_VOID;
 500         }
 501
 502         status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
 503         if (ACPI_FAILURE(status)) {
 504                 ACPI_FREE(local_gpe_event_info);
 505                 return_VOID;
 506         }
 507
 508         /* Must revalidate the gpe_number/gpe_block */
 509
 510         if (!acpi_ev_valid_gpe_event(gpe_event_info)) {
 511                 status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 512                 ACPI_FREE(local_gpe_event_info);
 513                 return_VOID;
 514         }
 515
 516         /*
 517          * Take a snapshot of the GPE info for this level - we copy the info to
 518          * prevent a race condition with remove_handler/remove_block.
 519          */
 520         ACPI_MEMCPY(local_gpe_event_info, gpe_event_info,
 521                     sizeof(struct acpi_gpe_event_info));
 522
 523         status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 524         if (ACPI_FAILURE(status)) {
 525                 return_VOID;
 526         }
 527
 528         /* Do the correct dispatch - normal method or implicit notify */
 529
 530         switch (local_gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) {
 531         case ACPI_GPE_DISPATCH_NOTIFY:
 532
 533                 /*
 534                  * Implicit notify.
 535                  * Dispatch a DEVICE_WAKE notify to the appropriate handler.
 536                  * NOTE: the request is queued for execution after this method
 537                  * completes. The notify handlers are NOT invoked synchronously
 538                  * from this thread -- because handlers may in turn run other
 539                  * control methods.
 540                  *
 541                  * June 2012: Expand implicit notify mechanism to support
 542                  * notifies on multiple device objects.
 543                  */
 544                 notify = local_gpe_event_info->dispatch.notify_list;
 545                 while (ACPI_SUCCESS(status) && notify) {
 546                         status =
 547                             acpi_ev_queue_notify_request(notify->device_node,
 548                                                          ACPI_NOTIFY_DEVICE_WAKE);
 549
 550                         notify = notify->next;
 551                 }
 552
 553                 break;
 554
 555         case ACPI_GPE_DISPATCH_METHOD:
 556
 557                 /* Allocate the evaluation information block */
 558
 559                 info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
 560                 if (!info) {
 561                         status = AE_NO_MEMORY;
 562                 } else {
 563                         /*
 564                          * Invoke the GPE Method (_Lxx, _Exx) i.e., evaluate the
 565                          * _Lxx/_Exx control method that corresponds to this GPE
 566                          */
 567                         info->prefix_node =
 568                             local_gpe_event_info->dispatch.method_node;
 569                         info->flags = ACPI_IGNORE_RETURN_VALUE;
 570
 571                         status = acpi_ns_evaluate(info);
 572                         ACPI_FREE(info);
 573                 }
 574
 575                 if (ACPI_FAILURE(status)) {
 576                         ACPI_EXCEPTION((AE_INFO, status,
 577                                         "while evaluating GPE method [%4.4s]",
 578                                         acpi_ut_get_node_name
 579                                         (local_gpe_event_info->dispatch.
 580                                          method_node)));
 581                 }
 582
 583                 break;
 584
 585         default:
 586                 return_VOID;    /* Should never happen */
 587         }
 588
 589         /* Defer enabling of GPE until all notify handlers are done */
 590
 591         status = acpi_os_execute(OSL_NOTIFY_HANDLER,
 592                                  acpi_ev_asynch_enable_gpe,
 593                                  local_gpe_event_info);
 594         if (ACPI_FAILURE(status)) {
 595                 ACPI_FREE(local_gpe_event_info);
 596         }
 597         return_VOID;
 598 }
 599
 600
 601 /*******************************************************************************
 602  *
 603  * FUNCTION:    acpi_ev_asynch_enable_gpe
 604  *
 605  * PARAMETERS:  Context (gpe_event_info) - Info for this GPE
 606  *              Callback from acpi_os_execute
 607  *
 608  * RETURN:      None
 609  *
 610  * DESCRIPTION: Asynchronous clear/enable for GPE. This allows the GPE to
 611  *              complete (i.e., finish execution of Notify)
 612  *
 613  ******************************************************************************/
 614
 615 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_enable_gpe(void *context)
 616 {
 617         struct acpi_gpe_event_info *gpe_event_info = context;
 618
 619         (void)acpi_ev_finish_gpe(gpe_event_info);
 620
 621         ACPI_FREE(gpe_event_info);
 622         return;
 623 }
 624
 625
 626 /*******************************************************************************
 627  *
 628  * FUNCTION:    acpi_ev_finish_gpe
 629  *
 630  * PARAMETERS:  gpe_event_info      - Info for this GPE
 631  *
 632  * RETURN:      Status
 633  *
 634  * DESCRIPTION: Clear/Enable a GPE. Common code that is used after execution
 635  *              of a GPE method or a synchronous or asynchronous GPE handler.
 636  *
 637  ******************************************************************************/
 638
 639 acpi_status acpi_ev_finish_gpe(struct acpi_gpe_event_info *gpe_event_info)
 640 {
 641         acpi_status status;
 642
 643         if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
 644             ACPI_GPE_LEVEL_TRIGGERED) {
 645                 /*
 646                  * GPE is level-triggered, we clear the GPE status bit after
 647                  * handling the event.
 648                  */
 649                 status = acpi_hw_clear_gpe(gpe_event_info);
 650                 if (ACPI_FAILURE(status)) {
 651                         return (status);
 652                 }
 653         }
 654
 655         /*
 656          * Enable this GPE, conditionally. This means that the GPE will
 657          * only be physically enabled if the enable_for_run bit is set
 658          * in the event_info.
 659          */
 660         (void)acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_CONDITIONAL_ENABLE);
 661         return (AE_OK);
 662 }
 663
 664
 665 /*******************************************************************************
 666  *
 667  * FUNCTION:    acpi_ev_gpe_dispatch
 668  *
 669  * PARAMETERS:  gpe_device      - Device node. NULL for GPE0/GPE1
 670  *              gpe_event_info  - Info for this GPE
 671  *              gpe_number      - Number relative to the parent GPE block
 672  *
 673  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
 674  *
 675  * DESCRIPTION: Dispatch a General Purpose Event to either a function (e.g. EC)
 676  *              or method (e.g. _Lxx/_Exx) handler.
 677  *
 678  *              This function executes at interrupt level.
 679  *
 680  ******************************************************************************/
 681
 682 u32
 683 acpi_ev_gpe_dispatch(struct acpi_namespace_node *gpe_device,
 684                     struct acpi_gpe_event_info *gpe_event_info, u32 gpe_number)
 685 {
 686         acpi_status status;
 687         u32 return_value;
 688
 689         ACPI_FUNCTION_TRACE(ev_gpe_dispatch);
 690
 691         /* Invoke global event handler if present */
 692
 693         acpi_gpe_count++;
 694         if (acpi_gbl_global_event_handler) {
 695                 acpi_gbl_global_event_handler(ACPI_EVENT_TYPE_GPE, gpe_device,
 696                                               gpe_number,
 697                                               acpi_gbl_global_event_handler_context);
 698         }
 699
 700         /*
 701          * If edge-triggered, clear the GPE status bit now. Note that
 702          * level-triggered events are cleared after the GPE is serviced.
 703          */
 704         if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
 705             ACPI_GPE_EDGE_TRIGGERED) {
 706                 status = acpi_hw_clear_gpe(gpe_event_info);
 707                 if (ACPI_FAILURE(status)) {
 708                         ACPI_EXCEPTION((AE_INFO, status,
 709                                         "Unable to clear GPE%02X", gpe_number));
 710                         return_VALUE(ACPI_INTERRUPT_NOT_HANDLED);
 711                 }
 712         }
 713
 714         /*
 715          * Always disable the GPE so that it does not keep firing before
 716          * any asynchronous activity completes (either from the execution
 717          * of a GPE method or an asynchronous GPE handler.)
 718          *
 719          * If there is no handler or method to run, just disable the
 720          * GPE and leave it disabled permanently to prevent further such
 721          * pointless events from firing.
 722          */
 723         status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
 724         if (ACPI_FAILURE(status)) {
 725                 ACPI_EXCEPTION((AE_INFO, status,
 726                                 "Unable to disable GPE%02X", gpe_number));
 727                 return_VALUE(ACPI_INTERRUPT_NOT_HANDLED);
 728         }
 729
 730         /*
 731          * Dispatch the GPE to either an installed handler or the control
 732          * method associated with this GPE (_Lxx or _Exx). If a handler
 733          * exists, we invoke it and do not attempt to run the method.
 734          * If there is neither a handler nor a method, leave the GPE
 735          * disabled.
 736          */
 737         switch (gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) {
 738         case ACPI_GPE_DISPATCH_HANDLER:
 739
 740                 /* Invoke the installed handler (at interrupt level) */
 741
 742                 return_value =
 743                     gpe_event_info->dispatch.handler->address(gpe_device,
 744                                                               gpe_number,
 745                                                               gpe_event_info->
 746                                                               dispatch.handler->
 747                                                               context);
 748
 749                 /* If requested, clear (if level-triggered) and reenable the GPE */
 750
 751                 if (return_value & ACPI_REENABLE_GPE) {
 752                         (void)acpi_ev_finish_gpe(gpe_event_info);
 753                 }
 754                 break;
 755
 756         case ACPI_GPE_DISPATCH_METHOD:
 757         case ACPI_GPE_DISPATCH_NOTIFY:
 758
 759                 /*
 760                  * Execute the method associated with the GPE
 761                  * NOTE: Level-triggered GPEs are cleared after the method completes.
 762                  */
 763                 status = acpi_os_execute(OSL_GPE_HANDLER,
 764                                          acpi_ev_asynch_execute_gpe_method,
 765                                          gpe_event_info);
 766                 if (ACPI_FAILURE(status)) {
 767                         ACPI_EXCEPTION((AE_INFO, status,
 768                                         "Unable to queue handler for GPE%02X - event disabled",
 769                                         gpe_number));
 770                 }
 771                 break;
 772
 773         default:
 774
 775                 /*
 776                  * No handler or method to run!
 777                  * 03/2010: This case should no longer be possible. We will not allow
 778                  * a GPE to be enabled if it has no handler or method.
 779                  */
 780                 ACPI_ERROR((AE_INFO,
 781                             "No handler or method for GPE%02X, disabling event",
 782                             gpe_number));
 783
 784                 break;
 785         }
 786
 787         return_VALUE(ACPI_INTERRUPT_HANDLED);
 788 }
 789
 790 #endif                          /* !ACPI_REDUCED_HARDWARE */