Pileus Git - ~andy/linux/blob - drivers/acpi/acpica/evxface.c

   1 /******************************************************************************
   2  *
   3  * Module Name: evxface - External interfaces for ACPI events
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2012, 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 <linux/export.h>
  45 #include <acpi/acpi.h>
  46 #include "accommon.h"
  47 #include "acnamesp.h"
  48 #include "acevents.h"
  49 #include "acinterp.h"
  50
  51 #define _COMPONENT          ACPI_EVENTS
  52 ACPI_MODULE_NAME("evxface")
  53
  54
  55 /*******************************************************************************
  56  *
  57  * FUNCTION:    acpi_install_notify_handler
  58  *
  59  * PARAMETERS:  Device          - The device for which notifies will be handled
  60  *              handler_type    - The type of handler:
  61  *                                  ACPI_SYSTEM_NOTIFY: System Handler (00-7F)
  62  *                                  ACPI_DEVICE_NOTIFY: Device Handler (80-FF)
  63  *                                  ACPI_ALL_NOTIFY:    Both System and Device
  64  *              Handler         - Address of the handler
  65  *              Context         - Value passed to the handler on each GPE
  66  *
  67  * RETURN:      Status
  68  *
  69  * DESCRIPTION: Install a handler for notifications on an ACPI Device,
  70  *              thermal_zone, or Processor object.
  71  *
  72  * NOTES:       The Root namespace object may have only one handler for each
  73  *              type of notify (System/Device). Device/Thermal/Processor objects
  74  *              may have one device notify handler, and multiple system notify
  75  *              handlers.
  76  *
  77  ******************************************************************************/
  78 acpi_status
  79 acpi_install_notify_handler(acpi_handle device,
  80                             u32 handler_type,
  81                             acpi_notify_handler handler, void *context)
  82 {
  83         struct acpi_namespace_node *node =
  84             ACPI_CAST_PTR(struct acpi_namespace_node, device);
  85         union acpi_operand_object *obj_desc;
  86         union acpi_operand_object *handler_obj;
  87         acpi_status status;
  88         u32 i;
  89
  90         ACPI_FUNCTION_TRACE(acpi_install_notify_handler);
  91
  92         /* Parameter validation */
  93
  94         if ((!device) || (!handler) || (!handler_type) ||
  95             (handler_type > ACPI_MAX_NOTIFY_HANDLER_TYPE)) {
  96                 return_ACPI_STATUS(AE_BAD_PARAMETER);
  97         }
  98
  99         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 100         if (ACPI_FAILURE(status)) {
 101                 return_ACPI_STATUS(status);
 102         }
 103
 104         /*
 105          * Root Object:
 106          * Registering a notify handler on the root object indicates that the
 107          * caller wishes to receive notifications for all objects. Note that
 108          * only one global handler can be registered per notify type.
 109          * Ensure that a handler is not already installed.
 110          */
 111         if (device == ACPI_ROOT_OBJECT) {
 112                 for (i = 0; i < ACPI_NUM_NOTIFY_TYPES; i++) {
 113                         if (handler_type & (i + 1)) {
 114                                 if (acpi_gbl_global_notify[i].handler) {
 115                                         status = AE_ALREADY_EXISTS;
 116                                         goto unlock_and_exit;
 117                                 }
 118
 119                                 acpi_gbl_global_notify[i].handler = handler;
 120                                 acpi_gbl_global_notify[i].context = context;
 121                         }
 122                 }
 123
 124                 goto unlock_and_exit;   /* Global notify handler installed, all done */
 125         }
 126
 127         /*
 128          * All Other Objects:
 129          * Caller will only receive notifications specific to the target
 130          * object. Note that only certain object types are allowed to
 131          * receive notifications.
 132          */
 133
 134         /* Are Notifies allowed on this object? */
 135
 136         if (!acpi_ev_is_notify_object(node)) {
 137                 status = AE_TYPE;
 138                 goto unlock_and_exit;
 139         }
 140
 141         /* Check for an existing internal object, might not exist */
 142
 143         obj_desc = acpi_ns_get_attached_object(node);
 144         if (!obj_desc) {
 145
 146                 /* Create a new object */
 147
 148                 obj_desc = acpi_ut_create_internal_object(node->type);
 149                 if (!obj_desc) {
 150                         status = AE_NO_MEMORY;
 151                         goto unlock_and_exit;
 152                 }
 153
 154                 /* Attach new object to the Node, remove local reference */
 155
 156                 status = acpi_ns_attach_object(device, obj_desc, node->type);
 157                 acpi_ut_remove_reference(obj_desc);
 158                 if (ACPI_FAILURE(status)) {
 159                         goto unlock_and_exit;
 160                 }
 161         }
 162
 163         /* Ensure that the handler is not already installed in the lists */
 164
 165         for (i = 0; i < ACPI_NUM_NOTIFY_TYPES; i++) {
 166                 if (handler_type & (i + 1)) {
 167                         handler_obj = obj_desc->common_notify.notify_list[i];
 168                         while (handler_obj) {
 169                                 if (handler_obj->notify.handler == handler) {
 170                                         status = AE_ALREADY_EXISTS;
 171                                         goto unlock_and_exit;
 172                                 }
 173
 174                                 handler_obj = handler_obj->notify.next[i];
 175                         }
 176                 }
 177         }
 178
 179         /* Create and populate a new notify handler object */
 180
 181         handler_obj = acpi_ut_create_internal_object(ACPI_TYPE_LOCAL_NOTIFY);
 182         if (!handler_obj) {
 183                 status = AE_NO_MEMORY;
 184                 goto unlock_and_exit;
 185         }
 186
 187         handler_obj->notify.node = node;
 188         handler_obj->notify.handler_type = handler_type;
 189         handler_obj->notify.handler = handler;
 190         handler_obj->notify.context = context;
 191
 192         /* Install the handler at the list head(s) */
 193
 194         for (i = 0; i < ACPI_NUM_NOTIFY_TYPES; i++) {
 195                 if (handler_type & (i + 1)) {
 196                         handler_obj->notify.next[i] =
 197                             obj_desc->common_notify.notify_list[i];
 198
 199                         obj_desc->common_notify.notify_list[i] = handler_obj;
 200                 }
 201         }
 202
 203         /* Add an extra reference if handler was installed in both lists */
 204
 205         if (handler_type == ACPI_ALL_NOTIFY) {
 206                 acpi_ut_add_reference(handler_obj);
 207         }
 208
 209 unlock_and_exit:
 210         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 211         return_ACPI_STATUS(status);
 212 }
 213
 214 ACPI_EXPORT_SYMBOL(acpi_install_notify_handler)
 215
 216 /*******************************************************************************
 217  *
 218  * FUNCTION:    acpi_remove_notify_handler
 219  *
 220  * PARAMETERS:  Device          - The device for which the handler is installed
 221  *              handler_type    - The type of handler:
 222  *                                  ACPI_SYSTEM_NOTIFY: System Handler (00-7F)
 223  *                                  ACPI_DEVICE_NOTIFY: Device Handler (80-FF)
 224  *                                  ACPI_ALL_NOTIFY:    Both System and Device
 225  *              Handler         - Address of the handler
 226  *
 227  * RETURN:      Status
 228  *
 229  * DESCRIPTION: Remove a handler for notifies on an ACPI device
 230  *
 231  ******************************************************************************/
 232 acpi_status
 233 acpi_remove_notify_handler(acpi_handle device,
 234                            u32 handler_type, acpi_notify_handler handler)
 235 {
 236         struct acpi_namespace_node *node =
 237             ACPI_CAST_PTR(struct acpi_namespace_node, device);
 238         union acpi_operand_object *obj_desc;
 239         union acpi_operand_object *handler_obj;
 240         union acpi_operand_object *previous_handler_obj;
 241         acpi_status status;
 242         u32 i;
 243
 244         ACPI_FUNCTION_TRACE(acpi_remove_notify_handler);
 245
 246         /* Parameter validation */
 247
 248         if ((!device) || (!handler) || (!handler_type) ||
 249             (handler_type > ACPI_MAX_NOTIFY_HANDLER_TYPE)) {
 250                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 251         }
 252         /* Make sure all deferred tasks are completed */
 253
 254         acpi_os_wait_events_complete();
 255
 256         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 257         if (ACPI_FAILURE(status)) {
 258                 return_ACPI_STATUS(status);
 259         }
 260
 261         /* Root Object. Global handlers are removed here */
 262
 263         if (device == ACPI_ROOT_OBJECT) {
 264                 for (i = 0; i < ACPI_NUM_NOTIFY_TYPES; i++) {
 265                         if (handler_type & (i + 1)) {
 266                                 if (!acpi_gbl_global_notify[i].handler ||
 267                                     (acpi_gbl_global_notify[i].handler !=
 268                                      handler)) {
 269                                         status = AE_NOT_EXIST;
 270                                         goto unlock_and_exit;
 271                                 }
 272
 273                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 274                                                   "Removing global notify handler\n"));
 275
 276                                 acpi_gbl_global_notify[i].handler = NULL;
 277                                 acpi_gbl_global_notify[i].context = NULL;
 278                         }
 279                 }
 280
 281                 goto unlock_and_exit;
 282         }
 283
 284         /* All other objects: Are Notifies allowed on this object? */
 285
 286         if (!acpi_ev_is_notify_object(node)) {
 287                 status = AE_TYPE;
 288                 goto unlock_and_exit;
 289         }
 290
 291         /* Must have an existing internal object */
 292
 293         obj_desc = acpi_ns_get_attached_object(node);
 294         if (!obj_desc) {
 295                 status = AE_NOT_EXIST;
 296                 goto unlock_and_exit;
 297         }
 298
 299         /* Internal object exists. Find the handler and remove it */
 300
 301         for (i = 0; i < ACPI_NUM_NOTIFY_TYPES; i++) {
 302                 if (handler_type & (i + 1)) {
 303                         handler_obj = obj_desc->common_notify.notify_list[i];
 304                         previous_handler_obj = NULL;
 305
 306                         /* Attempt to find the handler in the handler list */
 307
 308                         while (handler_obj &&
 309                                (handler_obj->notify.handler != handler)) {
 310                                 previous_handler_obj = handler_obj;
 311                                 handler_obj = handler_obj->notify.next[i];
 312                         }
 313
 314                         if (!handler_obj) {
 315                                 status = AE_NOT_EXIST;
 316                                 goto unlock_and_exit;
 317                         }
 318
 319                         /* Remove the handler object from the list */
 320
 321                         if (previous_handler_obj) {     /* Handler is not at the list head */
 322                                 previous_handler_obj->notify.next[i] =
 323                                     handler_obj->notify.next[i];
 324                         } else {        /* Handler is at the list head */
 325
 326                                 obj_desc->common_notify.notify_list[i] =
 327                                     handler_obj->notify.next[i];
 328                         }
 329
 330                         acpi_ut_remove_reference(handler_obj);
 331                 }
 332         }
 333
 334 unlock_and_exit:
 335         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 336         return_ACPI_STATUS(status);
 337 }
 338
 339 ACPI_EXPORT_SYMBOL(acpi_remove_notify_handler)
 340
 341 /*******************************************************************************
 342  *
 343  * FUNCTION:    acpi_install_exception_handler
 344  *
 345  * PARAMETERS:  handler         - Pointer to the handler function for the
 346  *                                event
 347  *
 348  * RETURN:      Status
 349  *
 350  * DESCRIPTION: Saves the pointer to the handler function
 351  *
 352  ******************************************************************************/
 353 #ifdef ACPI_FUTURE_USAGE
 354 acpi_status acpi_install_exception_handler(acpi_exception_handler handler)
 355 {
 356         acpi_status status;
 357
 358         ACPI_FUNCTION_TRACE(acpi_install_exception_handler);
 359
 360         status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
 361         if (ACPI_FAILURE(status)) {
 362                 return_ACPI_STATUS(status);
 363         }
 364
 365         /* Don't allow two handlers. */
 366
 367         if (acpi_gbl_exception_handler) {
 368                 status = AE_ALREADY_EXISTS;
 369                 goto cleanup;
 370         }
 371
 372         /* Install the handler */
 373
 374         acpi_gbl_exception_handler = handler;
 375
 376       cleanup:
 377         (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 378         return_ACPI_STATUS(status);
 379 }
 380
 381 ACPI_EXPORT_SYMBOL(acpi_install_exception_handler)
 382 #endif                          /*  ACPI_FUTURE_USAGE  */
 383
 384 #if (!ACPI_REDUCED_HARDWARE)
 385 /*******************************************************************************
 386  *
 387  * FUNCTION:    acpi_install_global_event_handler
 388  *
 389  * PARAMETERS:  handler         - Pointer to the global event handler function
 390  *              context         - Value passed to the handler on each event
 391  *
 392  * RETURN:      Status
 393  *
 394  * DESCRIPTION: Saves the pointer to the handler function. The global handler
 395  *              is invoked upon each incoming GPE and Fixed Event. It is
 396  *              invoked at interrupt level at the time of the event dispatch.
 397  *              Can be used to update event counters, etc.
 398  *
 399  ******************************************************************************/
 400 acpi_status
 401 acpi_install_global_event_handler(ACPI_GBL_EVENT_HANDLER handler, void *context)
 402 {
 403         acpi_status status;
 404
 405         ACPI_FUNCTION_TRACE(acpi_install_global_event_handler);
 406
 407         /* Parameter validation */
 408
 409         if (!handler) {
 410                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 411         }
 412
 413         status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
 414         if (ACPI_FAILURE(status)) {
 415                 return_ACPI_STATUS(status);
 416         }
 417
 418         /* Don't allow two handlers. */
 419
 420         if (acpi_gbl_global_event_handler) {
 421                 status = AE_ALREADY_EXISTS;
 422                 goto cleanup;
 423         }
 424
 425         acpi_gbl_global_event_handler = handler;
 426         acpi_gbl_global_event_handler_context = context;
 427
 428       cleanup:
 429         (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 430         return_ACPI_STATUS(status);
 431 }
 432
 433 ACPI_EXPORT_SYMBOL(acpi_install_global_event_handler)
 434
 435 /*******************************************************************************
 436  *
 437  * FUNCTION:    acpi_install_fixed_event_handler
 438  *
 439  * PARAMETERS:  event           - Event type to enable.
 440  *              handler         - Pointer to the handler function for the
 441  *                                event
 442  *              context         - Value passed to the handler on each GPE
 443  *
 444  * RETURN:      Status
 445  *
 446  * DESCRIPTION: Saves the pointer to the handler function and then enables the
 447  *              event.
 448  *
 449  ******************************************************************************/
 450 acpi_status
 451 acpi_install_fixed_event_handler(u32 event,
 452                                  acpi_event_handler handler, void *context)
 453 {
 454         acpi_status status;
 455
 456         ACPI_FUNCTION_TRACE(acpi_install_fixed_event_handler);
 457
 458         /* Parameter validation */
 459
 460         if (event > ACPI_EVENT_MAX) {
 461                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 462         }
 463
 464         status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
 465         if (ACPI_FAILURE(status)) {
 466                 return_ACPI_STATUS(status);
 467         }
 468
 469         /* Don't allow two handlers. */
 470
 471         if (NULL != acpi_gbl_fixed_event_handlers[event].handler) {
 472                 status = AE_ALREADY_EXISTS;
 473                 goto cleanup;
 474         }
 475
 476         /* Install the handler before enabling the event */
 477
 478         acpi_gbl_fixed_event_handlers[event].handler = handler;
 479         acpi_gbl_fixed_event_handlers[event].context = context;
 480
 481         status = acpi_clear_event(event);
 482         if (ACPI_SUCCESS(status))
 483                 status = acpi_enable_event(event, 0);
 484         if (ACPI_FAILURE(status)) {
 485                 ACPI_WARNING((AE_INFO, "Could not enable fixed event 0x%X",
 486                               event));
 487
 488                 /* Remove the handler */
 489
 490                 acpi_gbl_fixed_event_handlers[event].handler = NULL;
 491                 acpi_gbl_fixed_event_handlers[event].context = NULL;
 492         } else {
 493                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 494                                   "Enabled fixed event %X, Handler=%p\n", event,
 495                                   handler));
 496         }
 497
 498       cleanup:
 499         (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 500         return_ACPI_STATUS(status);
 501 }
 502
 503 ACPI_EXPORT_SYMBOL(acpi_install_fixed_event_handler)
 504
 505 /*******************************************************************************
 506  *
 507  * FUNCTION:    acpi_remove_fixed_event_handler
 508  *
 509  * PARAMETERS:  event           - Event type to disable.
 510  *              handler         - Address of the handler
 511  *
 512  * RETURN:      Status
 513  *
 514  * DESCRIPTION: Disables the event and unregisters the event handler.
 515  *
 516  ******************************************************************************/
 517 acpi_status
 518 acpi_remove_fixed_event_handler(u32 event, acpi_event_handler handler)
 519 {
 520         acpi_status status = AE_OK;
 521
 522         ACPI_FUNCTION_TRACE(acpi_remove_fixed_event_handler);
 523
 524         /* Parameter validation */
 525
 526         if (event > ACPI_EVENT_MAX) {
 527                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 528         }
 529
 530         status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
 531         if (ACPI_FAILURE(status)) {
 532                 return_ACPI_STATUS(status);
 533         }
 534
 535         /* Disable the event before removing the handler */
 536
 537         status = acpi_disable_event(event, 0);
 538
 539         /* Always Remove the handler */
 540
 541         acpi_gbl_fixed_event_handlers[event].handler = NULL;
 542         acpi_gbl_fixed_event_handlers[event].context = NULL;
 543
 544         if (ACPI_FAILURE(status)) {
 545                 ACPI_WARNING((AE_INFO,
 546                               "Could not write to fixed event enable register 0x%X",
 547                               event));
 548         } else {
 549                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Disabled fixed event %X\n",
 550                                   event));
 551         }
 552
 553         (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 554         return_ACPI_STATUS(status);
 555 }
 556
 557 ACPI_EXPORT_SYMBOL(acpi_remove_fixed_event_handler)
 558
 559 /*******************************************************************************
 560  *
 561  * FUNCTION:    acpi_install_gpe_handler
 562  *
 563  * PARAMETERS:  gpe_device      - Namespace node for the GPE (NULL for FADT
 564  *                                defined GPEs)
 565  *              gpe_number      - The GPE number within the GPE block
 566  *              type            - Whether this GPE should be treated as an
 567  *                                edge- or level-triggered interrupt.
 568  *              address         - Address of the handler
 569  *              context         - Value passed to the handler on each GPE
 570  *
 571  * RETURN:      Status
 572  *
 573  * DESCRIPTION: Install a handler for a General Purpose Event.
 574  *
 575  ******************************************************************************/
 576 acpi_status
 577 acpi_install_gpe_handler(acpi_handle gpe_device,
 578                          u32 gpe_number,
 579                          u32 type, acpi_gpe_handler address, void *context)
 580 {
 581         struct acpi_gpe_event_info *gpe_event_info;
 582         struct acpi_gpe_handler_info *handler;
 583         acpi_status status;
 584         acpi_cpu_flags flags;
 585
 586         ACPI_FUNCTION_TRACE(acpi_install_gpe_handler);
 587
 588         /* Parameter validation */
 589
 590         if ((!address) || (type & ~ACPI_GPE_XRUPT_TYPE_MASK)) {
 591                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 592         }
 593
 594         status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
 595         if (ACPI_FAILURE(status)) {
 596                 return_ACPI_STATUS(status);
 597         }
 598
 599         /* Allocate memory for the handler object */
 600
 601         handler = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_gpe_handler_info));
 602         if (!handler) {
 603                 status = AE_NO_MEMORY;
 604                 goto unlock_and_exit;
 605         }
 606
 607         flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
 608
 609         /* Ensure that we have a valid GPE number */
 610
 611         gpe_event_info = acpi_ev_get_gpe_event_info(gpe_device, gpe_number);
 612         if (!gpe_event_info) {
 613                 status = AE_BAD_PARAMETER;
 614                 goto free_and_exit;
 615         }
 616
 617         /* Make sure that there isn't a handler there already */
 618
 619         if ((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) ==
 620             ACPI_GPE_DISPATCH_HANDLER) {
 621                 status = AE_ALREADY_EXISTS;
 622                 goto free_and_exit;
 623         }
 624
 625         /* Allocate and init handler object */
 626
 627         handler->address = address;
 628         handler->context = context;
 629         handler->method_node = gpe_event_info->dispatch.method_node;
 630         handler->original_flags = gpe_event_info->flags &
 631                         (ACPI_GPE_XRUPT_TYPE_MASK | ACPI_GPE_DISPATCH_MASK);
 632
 633         /*
 634          * If the GPE is associated with a method, it might have been enabled
 635          * automatically during initialization, in which case it has to be
 636          * disabled now to avoid spurious execution of the handler.
 637          */
 638
 639         if ((handler->original_flags & ACPI_GPE_DISPATCH_METHOD)
 640             && gpe_event_info->runtime_count) {
 641                 handler->originally_enabled = 1;
 642                 (void)acpi_ev_remove_gpe_reference(gpe_event_info);
 643         }
 644
 645         /* Install the handler */
 646
 647         gpe_event_info->dispatch.handler = handler;
 648
 649         /* Setup up dispatch flags to indicate handler (vs. method) */
 650
 651         gpe_event_info->flags &=
 652             ~(ACPI_GPE_XRUPT_TYPE_MASK | ACPI_GPE_DISPATCH_MASK);
 653         gpe_event_info->flags |= (u8) (type | ACPI_GPE_DISPATCH_HANDLER);
 654
 655         acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 656
 657 unlock_and_exit:
 658         (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 659         return_ACPI_STATUS(status);
 660
 661 free_and_exit:
 662         acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 663         ACPI_FREE(handler);
 664         goto unlock_and_exit;
 665 }
 666
 667 ACPI_EXPORT_SYMBOL(acpi_install_gpe_handler)
 668
 669 /*******************************************************************************
 670  *
 671  * FUNCTION:    acpi_remove_gpe_handler
 672  *
 673  * PARAMETERS:  gpe_device      - Namespace node for the GPE (NULL for FADT
 674  *                                defined GPEs)
 675  *              gpe_number      - The event to remove a handler
 676  *              address         - Address of the handler
 677  *
 678  * RETURN:      Status
 679  *
 680  * DESCRIPTION: Remove a handler for a General Purpose acpi_event.
 681  *
 682  ******************************************************************************/
 683 acpi_status
 684 acpi_remove_gpe_handler(acpi_handle gpe_device,
 685                         u32 gpe_number, acpi_gpe_handler address)
 686 {
 687         struct acpi_gpe_event_info *gpe_event_info;
 688         struct acpi_gpe_handler_info *handler;
 689         acpi_status status;
 690         acpi_cpu_flags flags;
 691
 692         ACPI_FUNCTION_TRACE(acpi_remove_gpe_handler);
 693
 694         /* Parameter validation */
 695
 696         if (!address) {
 697                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 698         }
 699
 700         /* Make sure all deferred tasks are completed */
 701
 702         acpi_os_wait_events_complete();
 703
 704         status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
 705         if (ACPI_FAILURE(status)) {
 706                 return_ACPI_STATUS(status);
 707         }
 708
 709         flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
 710
 711         /* Ensure that we have a valid GPE number */
 712
 713         gpe_event_info = acpi_ev_get_gpe_event_info(gpe_device, gpe_number);
 714         if (!gpe_event_info) {
 715                 status = AE_BAD_PARAMETER;
 716                 goto unlock_and_exit;
 717         }
 718
 719         /* Make sure that a handler is indeed installed */
 720
 721         if ((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) !=
 722             ACPI_GPE_DISPATCH_HANDLER) {
 723                 status = AE_NOT_EXIST;
 724                 goto unlock_and_exit;
 725         }
 726
 727         /* Make sure that the installed handler is the same */
 728
 729         if (gpe_event_info->dispatch.handler->address != address) {
 730                 status = AE_BAD_PARAMETER;
 731                 goto unlock_and_exit;
 732         }
 733
 734         /* Remove the handler */
 735
 736         handler = gpe_event_info->dispatch.handler;
 737
 738         /* Restore Method node (if any), set dispatch flags */
 739
 740         gpe_event_info->dispatch.method_node = handler->method_node;
 741         gpe_event_info->flags &=
 742                 ~(ACPI_GPE_XRUPT_TYPE_MASK | ACPI_GPE_DISPATCH_MASK);
 743         gpe_event_info->flags |= handler->original_flags;
 744
 745         /*
 746          * If the GPE was previously associated with a method and it was
 747          * enabled, it should be enabled at this point to restore the
 748          * post-initialization configuration.
 749          */
 750
 751         if ((handler->original_flags & ACPI_GPE_DISPATCH_METHOD)
 752             && handler->originally_enabled)
 753                 (void)acpi_ev_add_gpe_reference(gpe_event_info);
 754
 755         /* Now we can free the handler object */
 756
 757         ACPI_FREE(handler);
 758
 759 unlock_and_exit:
 760         acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 761
 762         (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 763         return_ACPI_STATUS(status);
 764 }
 765
 766 ACPI_EXPORT_SYMBOL(acpi_remove_gpe_handler)
 767
 768 /*******************************************************************************
 769  *
 770  * FUNCTION:    acpi_acquire_global_lock
 771  *
 772  * PARAMETERS:  timeout         - How long the caller is willing to wait
 773  *              handle          - Where the handle to the lock is returned
 774  *                                (if acquired)
 775  *
 776  * RETURN:      Status
 777  *
 778  * DESCRIPTION: Acquire the ACPI Global Lock
 779  *
 780  * Note: Allows callers with the same thread ID to acquire the global lock
 781  * multiple times. In other words, externally, the behavior of the global lock
 782  * is identical to an AML mutex. On the first acquire, a new handle is
 783  * returned. On any subsequent calls to acquire by the same thread, the same
 784  * handle is returned.
 785  *
 786  ******************************************************************************/
 787 acpi_status acpi_acquire_global_lock(u16 timeout, u32 * handle)
 788 {
 789         acpi_status status;
 790
 791         if (!handle) {
 792                 return (AE_BAD_PARAMETER);
 793         }
 794
 795         /* Must lock interpreter to prevent race conditions */
 796
 797         acpi_ex_enter_interpreter();
 798
 799         status = acpi_ex_acquire_mutex_object(timeout,
 800                                               acpi_gbl_global_lock_mutex,
 801                                               acpi_os_get_thread_id());
 802
 803         if (ACPI_SUCCESS(status)) {
 804
 805                 /* Return the global lock handle (updated in acpi_ev_acquire_global_lock) */
 806
 807                 *handle = acpi_gbl_global_lock_handle;
 808         }
 809
 810         acpi_ex_exit_interpreter();
 811         return (status);
 812 }
 813
 814 ACPI_EXPORT_SYMBOL(acpi_acquire_global_lock)
 815
 816 /*******************************************************************************
 817  *
 818  * FUNCTION:    acpi_release_global_lock
 819  *
 820  * PARAMETERS:  handle      - Returned from acpi_acquire_global_lock
 821  *
 822  * RETURN:      Status
 823  *
 824  * DESCRIPTION: Release the ACPI Global Lock. The handle must be valid.
 825  *
 826  ******************************************************************************/
 827 acpi_status acpi_release_global_lock(u32 handle)
 828 {
 829         acpi_status status;
 830
 831         if (!handle || (handle != acpi_gbl_global_lock_handle)) {
 832                 return (AE_NOT_ACQUIRED);
 833         }
 834
 835         status = acpi_ex_release_mutex_object(acpi_gbl_global_lock_mutex);
 836         return (status);
 837 }
 838
 839 ACPI_EXPORT_SYMBOL(acpi_release_global_lock)
 840 #endif                          /* !ACPI_REDUCED_HARDWARE */