evxface.c

Go to the documentation of this file.

/******************************************************************************
 *
 * Module Name: evxface - External interfaces for ACPI events
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2012, Intel Corp.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 */

#include <linux/export.h>
#include <acpi/acpi.h>
#include "accommon.h"
#include "acnamesp.h"
#include "acevents.h"
#include "acinterp.h"

#define _COMPONENT          ACPI_EVENTS
ACPI_MODULE_NAME("evxface")


/*******************************************************************************
 *
 * FUNCTION:    acpi_install_notify_handler
 *
 * PARAMETERS:  Device          - The device for which notifies will be handled
 *              handler_type    - The type of handler:
 *                                  ACPI_SYSTEM_NOTIFY: System Handler (00-7F)
 *                                  ACPI_DEVICE_NOTIFY: Device Handler (80-FF)
 *                                  ACPI_ALL_NOTIFY:    Both System and Device
 *              Handler         - Address of the handler
 *              Context         - Value passed to the handler on each GPE
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Install a handler for notifications on an ACPI Device,
 *              thermal_zone, or Processor object.
 *
 * NOTES:       The Root namespace object may have only one handler for each
 *              type of notify (System/Device). Device/Thermal/Processor objects
 *              may have one device notify handler, and multiple system notify
 *              handlers.
 *
 ******************************************************************************/
acpi_status
acpi_install_notify_handler(acpi_handle device,
                u32 handler_type,
                acpi_notify_handler handler, void *context)
{
    struct acpi_namespace_node *node =
        ACPI_CAST_PTR(struct acpi_namespace_node, device);
    union acpi_operand_object *obj_desc;
    union acpi_operand_object *handler_obj;
    acpi_status status;
    u32 i;

    ACPI_FUNCTION_TRACE(acpi_install_notify_handler);

    /* Parameter validation */

    if ((!device) || (!handler) || (!handler_type) ||
        (handler_type > ACPI_MAX_NOTIFY_HANDLER_TYPE)) {
        return_ACPI_STATUS(AE_BAD_PARAMETER);
    }

    status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
    if (ACPI_FAILURE(status)) {
        return_ACPI_STATUS(status);
    }

    /*
     * Root Object:
     * Registering a notify handler on the root object indicates that the
     * caller wishes to receive notifications for all objects. Note that
     * only one global handler can be registered per notify type.
     * Ensure that a handler is not already installed.
     */
    if (device == ACPI_ROOT_OBJECT) {
        for (i = 0; i < ACPI_NUM_NOTIFY_TYPES; i++) {
            if (handler_type & (i + 1)) {
                if (acpi_gbl_global_notify[i].handler) {
                    status = AE_ALREADY_EXISTS;
                    goto unlock_and_exit;
                }

                acpi_gbl_global_notify[i].handler = handler;
                acpi_gbl_global_notify[i].context = context;
            }
        }

        goto unlock_and_exit;   /* Global notify handler installed, all done */
    }

    /*
     * All Other Objects:
     * Caller will only receive notifications specific to the target
     * object. Note that only certain object types are allowed to
     * receive notifications.
     */

    /* Are Notifies allowed on this object? */

    if (!acpi_ev_is_notify_object(node)) {
        status = AE_TYPE;
        goto unlock_and_exit;
    }

    /* Check for an existing internal object, might not exist */

    obj_desc = acpi_ns_get_attached_object(node);
    if (!obj_desc) {

        /* Create a new object */

        obj_desc = acpi_ut_create_internal_object(node->type);
        if (!obj_desc) {
            status = AE_NO_MEMORY;
            goto unlock_and_exit;
        }

        /* Attach new object to the Node, remove local reference */

        status = acpi_ns_attach_object(device, obj_desc, node->type);
        acpi_ut_remove_reference(obj_desc);
        if (ACPI_FAILURE(status)) {
            goto unlock_and_exit;
        }
    }

    /* Ensure that the handler is not already installed in the lists */

    for (i = 0; i < ACPI_NUM_NOTIFY_TYPES; i++) {
        if (handler_type & (i + 1)) {
            handler_obj = obj_desc->common_notify.notify_list[i];
            while (handler_obj) {
                if (handler_obj->notify.handler == handler) {
                    status = AE_ALREADY_EXISTS;
                    goto unlock_and_exit;
                }

                handler_obj = handler_obj->notify.next[i];
            }
        }
    }

    /* Create and populate a new notify handler object */

    handler_obj = acpi_ut_create_internal_object(ACPI_TYPE_LOCAL_NOTIFY);
    if (!handler_obj) {
        status = AE_NO_MEMORY;
        goto unlock_and_exit;
    }

    handler_obj->notify.node = node;
    handler_obj->notify.handler_type = handler_type;
    handler_obj->notify.handler = handler;
    handler_obj->notify.context = context;

    /* Install the handler at the list head(s) */

    for (i = 0; i < ACPI_NUM_NOTIFY_TYPES; i++) {
        if (handler_type & (i + 1)) {
            handler_obj->notify.next[i] =
                obj_desc->common_notify.notify_list[i];

            obj_desc->common_notify.notify_list[i] = handler_obj;
        }
    }

    /* Add an extra reference if handler was installed in both lists */

    if (handler_type == ACPI_ALL_NOTIFY) {
        acpi_ut_add_reference(handler_obj);
    }

unlock_and_exit:
    (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
    return_ACPI_STATUS(status);
}

ACPI_EXPORT_SYMBOL(acpi_install_notify_handler)

/*******************************************************************************
 *
 * FUNCTION:    acpi_remove_notify_handler
 *
 * PARAMETERS:  Device          - The device for which the handler is installed
 *              handler_type    - The type of handler:
 *                                  ACPI_SYSTEM_NOTIFY: System Handler (00-7F)
 *                                  ACPI_DEVICE_NOTIFY: Device Handler (80-FF)
 *                                  ACPI_ALL_NOTIFY:    Both System and Device
 *              Handler         - Address of the handler
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Remove a handler for notifies on an ACPI device
 *
 ******************************************************************************/
acpi_status
acpi_remove_notify_handler(acpi_handle device,
               u32 handler_type, acpi_notify_handler handler)
{
    struct acpi_namespace_node *node =
        ACPI_CAST_PTR(struct acpi_namespace_node, device);
    union acpi_operand_object *obj_desc;
    union acpi_operand_object *handler_obj;
    union acpi_operand_object *previous_handler_obj;
    acpi_status status;
    u32 i;

    ACPI_FUNCTION_TRACE(acpi_remove_notify_handler);

    /* Parameter validation */

    if ((!device) || (!handler) || (!handler_type) ||
        (handler_type > ACPI_MAX_NOTIFY_HANDLER_TYPE)) {
        return_ACPI_STATUS(AE_BAD_PARAMETER);
    }
    /* Make sure all deferred tasks are completed */

    acpi_os_wait_events_complete();

    status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
    if (ACPI_FAILURE(status)) {
        return_ACPI_STATUS(status);
    }

    /* Root Object. Global handlers are removed here */

    if (device == ACPI_ROOT_OBJECT) {
        for (i = 0; i < ACPI_NUM_NOTIFY_TYPES; i++) {
            if (handler_type & (i + 1)) {
                if (!acpi_gbl_global_notify[i].handler ||
                    (acpi_gbl_global_notify[i].handler !=
                     handler)) {
                    status = AE_NOT_EXIST;
                    goto unlock_and_exit;
                }

                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                          "Removing global notify handler\n"));

                acpi_gbl_global_notify[i].handler = NULL;
                acpi_gbl_global_notify[i].context = NULL;
            }
        }

        goto unlock_and_exit;
    }

    /* All other objects: Are Notifies allowed on this object? */

    if (!acpi_ev_is_notify_object(node)) {
        status = AE_TYPE;
        goto unlock_and_exit;
    }

    /* Must have an existing internal object */

    obj_desc = acpi_ns_get_attached_object(node);
    if (!obj_desc) {
        status = AE_NOT_EXIST;
        goto unlock_and_exit;
    }

    /* Internal object exists. Find the handler and remove it */

    for (i = 0; i < ACPI_NUM_NOTIFY_TYPES; i++) {
        if (handler_type & (i + 1)) {
            handler_obj = obj_desc->common_notify.notify_list[i];
            previous_handler_obj = NULL;

            /* Attempt to find the handler in the handler list */

            while (handler_obj &&
                   (handler_obj->notify.handler != handler)) {
                previous_handler_obj = handler_obj;
                handler_obj = handler_obj->notify.next[i];
            }

            if (!handler_obj) {
                status = AE_NOT_EXIST;
                goto unlock_and_exit;
            }

            /* Remove the handler object from the list */

            if (previous_handler_obj) { /* Handler is not at the list head */
                previous_handler_obj->notify.next[i] =
                    handler_obj->notify.next[i];
            } else {    /* Handler is at the list head */

                obj_desc->common_notify.notify_list[i] =
                    handler_obj->notify.next[i];
            }

            acpi_ut_remove_reference(handler_obj);
        }
    }

unlock_and_exit:
    (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
    return_ACPI_STATUS(status);
}

ACPI_EXPORT_SYMBOL(acpi_remove_notify_handler)

/*******************************************************************************
 *
 * FUNCTION:    acpi_install_exception_handler
 *
 * PARAMETERS:  handler         - Pointer to the handler function for the
 *                                event
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Saves the pointer to the handler function
 *
 ******************************************************************************/
#ifdef ACPI_FUTURE_USAGE
acpi_status acpi_install_exception_handler(acpi_exception_handler handler)
{
    acpi_status status;

    ACPI_FUNCTION_TRACE(acpi_install_exception_handler);

    status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
    if (ACPI_FAILURE(status)) {
        return_ACPI_STATUS(status);
    }

    /* Don't allow two handlers. */

    if (acpi_gbl_exception_handler) {
        status = AE_ALREADY_EXISTS;
        goto cleanup;
    }

    /* Install the handler */

    acpi_gbl_exception_handler = handler;

      cleanup:
    (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
    return_ACPI_STATUS(status);
}

ACPI_EXPORT_SYMBOL(acpi_install_exception_handler)
#endif              /*  ACPI_FUTURE_USAGE  */

#if (!ACPI_REDUCED_HARDWARE)
/*******************************************************************************
 *
 * FUNCTION:    acpi_install_global_event_handler
 *
 * PARAMETERS:  handler         - Pointer to the global event handler function
 *              context         - Value passed to the handler on each event
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Saves the pointer to the handler function. The global handler
 *              is invoked upon each incoming GPE and Fixed Event. It is
 *              invoked at interrupt level at the time of the event dispatch.
 *              Can be used to update event counters, etc.
 *
 ******************************************************************************/
acpi_status
acpi_install_global_event_handler(ACPI_GBL_EVENT_HANDLER handler, void *context)
{
    acpi_status status;

    ACPI_FUNCTION_TRACE(acpi_install_global_event_handler);

    /* Parameter validation */

    if (!handler) {
        return_ACPI_STATUS(AE_BAD_PARAMETER);
    }

    status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
    if (ACPI_FAILURE(status)) {
        return_ACPI_STATUS(status);
    }

    /* Don't allow two handlers. */

    if (acpi_gbl_global_event_handler) {
        status = AE_ALREADY_EXISTS;
        goto cleanup;
    }

    acpi_gbl_global_event_handler = handler;
    acpi_gbl_global_event_handler_context = context;

      cleanup:
    (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
    return_ACPI_STATUS(status);
}

ACPI_EXPORT_SYMBOL(acpi_install_global_event_handler)

/*******************************************************************************
 *
 * FUNCTION:    acpi_install_fixed_event_handler
 *
 * PARAMETERS:  event           - Event type to enable.
 *              handler         - Pointer to the handler function for the
 *                                event
 *              context         - Value passed to the handler on each GPE
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Saves the pointer to the handler function and then enables the
 *              event.
 *
 ******************************************************************************/
acpi_status
acpi_install_fixed_event_handler(u32 event,
                 acpi_event_handler handler, void *context)
{
    acpi_status status;

    ACPI_FUNCTION_TRACE(acpi_install_fixed_event_handler);

    /* Parameter validation */

    if (event > ACPI_EVENT_MAX) {
        return_ACPI_STATUS(AE_BAD_PARAMETER);
    }

    status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
    if (ACPI_FAILURE(status)) {
        return_ACPI_STATUS(status);
    }

    /* Don't allow two handlers. */

    if (NULL != acpi_gbl_fixed_event_handlers[event].handler) {
        status = AE_ALREADY_EXISTS;
        goto cleanup;
    }

    /* Install the handler before enabling the event */

    acpi_gbl_fixed_event_handlers[event].handler = handler;
    acpi_gbl_fixed_event_handlers[event].context = context;

    status = acpi_clear_event(event);
    if (ACPI_SUCCESS(status))
        status = acpi_enable_event(event, 0);
    if (ACPI_FAILURE(status)) {
        ACPI_WARNING((AE_INFO, "Could not enable fixed event 0x%X",
                  event));

        /* Remove the handler */

        acpi_gbl_fixed_event_handlers[event].handler = NULL;
        acpi_gbl_fixed_event_handlers[event].context = NULL;
    } else {
        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                  "Enabled fixed event %X, Handler=%p\n", event,
                  handler));
    }

      cleanup:
    (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
    return_ACPI_STATUS(status);
}

ACPI_EXPORT_SYMBOL(acpi_install_fixed_event_handler)

/*******************************************************************************
 *
 * FUNCTION:    acpi_remove_fixed_event_handler
 *
 * PARAMETERS:  event           - Event type to disable.
 *              handler         - Address of the handler
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Disables the event and unregisters the event handler.
 *
 ******************************************************************************/
acpi_status
acpi_remove_fixed_event_handler(u32 event, acpi_event_handler handler)
{
    acpi_status status = AE_OK;

    ACPI_FUNCTION_TRACE(acpi_remove_fixed_event_handler);

    /* Parameter validation */

    if (event > ACPI_EVENT_MAX) {
        return_ACPI_STATUS(AE_BAD_PARAMETER);
    }

    status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
    if (ACPI_FAILURE(status)) {
        return_ACPI_STATUS(status);
    }

    /* Disable the event before removing the handler */

    status = acpi_disable_event(event, 0);

    /* Always Remove the handler */

    acpi_gbl_fixed_event_handlers[event].handler = NULL;
    acpi_gbl_fixed_event_handlers[event].context = NULL;

    if (ACPI_FAILURE(status)) {
        ACPI_WARNING((AE_INFO,
                  "Could not write to fixed event enable register 0x%X",
                  event));
    } else {
        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Disabled fixed event %X\n",
                  event));
    }

    (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
    return_ACPI_STATUS(status);
}

ACPI_EXPORT_SYMBOL(acpi_remove_fixed_event_handler)

/*******************************************************************************
 *
 * FUNCTION:    acpi_install_gpe_handler
 *
 * PARAMETERS:  gpe_device      - Namespace node for the GPE (NULL for FADT
 *                                defined GPEs)
 *              gpe_number      - The GPE number within the GPE block
 *              type            - Whether this GPE should be treated as an
 *                                edge- or level-triggered interrupt.
 *              address         - Address of the handler
 *              context         - Value passed to the handler on each GPE
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Install a handler for a General Purpose Event.
 *
 ******************************************************************************/
acpi_status
acpi_install_gpe_handler(acpi_handle gpe_device,
             u32 gpe_number,
             u32 type, acpi_gpe_handler address, void *context)
{
    struct acpi_gpe_event_info *gpe_event_info;
    struct acpi_gpe_handler_info *handler;
    acpi_status status;
    acpi_cpu_flags flags;

    ACPI_FUNCTION_TRACE(acpi_install_gpe_handler);

    /* Parameter validation */

    if ((!address) || (type & ~ACPI_GPE_XRUPT_TYPE_MASK)) {
        return_ACPI_STATUS(AE_BAD_PARAMETER);
    }

    status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
    if (ACPI_FAILURE(status)) {
        return_ACPI_STATUS(status);
    }

    /* Allocate memory for the handler object */

    handler = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_gpe_handler_info));
    if (!handler) {
        status = AE_NO_MEMORY;
        goto unlock_and_exit;
    }

    flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);

    /* Ensure that we have a valid GPE number */

    gpe_event_info = acpi_ev_get_gpe_event_info(gpe_device, gpe_number);
    if (!gpe_event_info) {
        status = AE_BAD_PARAMETER;
        goto free_and_exit;
    }

    /* Make sure that there isn't a handler there already */

    if ((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) ==
        ACPI_GPE_DISPATCH_HANDLER) {
        status = AE_ALREADY_EXISTS;
        goto free_and_exit;
    }

    /* Allocate and init handler object */

    handler->address = address;
    handler->context = context;
    handler->method_node = gpe_event_info->dispatch.method_node;
    handler->original_flags = gpe_event_info->flags &
            (ACPI_GPE_XRUPT_TYPE_MASK | ACPI_GPE_DISPATCH_MASK);

    /*
     * If the GPE is associated with a method, it might have been enabled
     * automatically during initialization, in which case it has to be
     * disabled now to avoid spurious execution of the handler.
     */

    if ((handler->original_flags & ACPI_GPE_DISPATCH_METHOD)
        && gpe_event_info->runtime_count) {
        handler->originally_enabled = 1;
        (void)acpi_ev_remove_gpe_reference(gpe_event_info);
    }

    /* Install the handler */

    gpe_event_info->dispatch.handler = handler;

    /* Setup up dispatch flags to indicate handler (vs. method) */

    gpe_event_info->flags &=
        ~(ACPI_GPE_XRUPT_TYPE_MASK | ACPI_GPE_DISPATCH_MASK);
    gpe_event_info->flags |= (u8) (type | ACPI_GPE_DISPATCH_HANDLER);

    acpi_os_release_lock(acpi_gbl_gpe_lock, flags);

unlock_and_exit:
    (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
    return_ACPI_STATUS(status);

free_and_exit:
    acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
    ACPI_FREE(handler);
    goto unlock_and_exit;
}

ACPI_EXPORT_SYMBOL(acpi_install_gpe_handler)

/*******************************************************************************
 *
 * FUNCTION:    acpi_remove_gpe_handler
 *
 * PARAMETERS:  gpe_device      - Namespace node for the GPE (NULL for FADT
 *                                defined GPEs)
 *              gpe_number      - The event to remove a handler
 *              address         - Address of the handler
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Remove a handler for a General Purpose acpi_event.
 *
 ******************************************************************************/
acpi_status
acpi_remove_gpe_handler(acpi_handle gpe_device,
            u32 gpe_number, acpi_gpe_handler address)
{
    struct acpi_gpe_event_info *gpe_event_info;
    struct acpi_gpe_handler_info *handler;
    acpi_status status;
    acpi_cpu_flags flags;

    ACPI_FUNCTION_TRACE(acpi_remove_gpe_handler);

    /* Parameter validation */

    if (!address) {
        return_ACPI_STATUS(AE_BAD_PARAMETER);
    }

    /* Make sure all deferred tasks are completed */

    acpi_os_wait_events_complete();

    status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
    if (ACPI_FAILURE(status)) {
        return_ACPI_STATUS(status);
    }

    flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);

    /* Ensure that we have a valid GPE number */

    gpe_event_info = acpi_ev_get_gpe_event_info(gpe_device, gpe_number);
    if (!gpe_event_info) {
        status = AE_BAD_PARAMETER;
        goto unlock_and_exit;
    }

    /* Make sure that a handler is indeed installed */

    if ((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) !=
        ACPI_GPE_DISPATCH_HANDLER) {
        status = AE_NOT_EXIST;
        goto unlock_and_exit;
    }

    /* Make sure that the installed handler is the same */

    if (gpe_event_info->dispatch.handler->address != address) {
        status = AE_BAD_PARAMETER;
        goto unlock_and_exit;
    }

    /* Remove the handler */

    handler = gpe_event_info->dispatch.handler;

    /* Restore Method node (if any), set dispatch flags */

    gpe_event_info->dispatch.method_node = handler->method_node;
    gpe_event_info->flags &=
        ~(ACPI_GPE_XRUPT_TYPE_MASK | ACPI_GPE_DISPATCH_MASK);
    gpe_event_info->flags |= handler->original_flags;

    /*
     * If the GPE was previously associated with a method and it was
     * enabled, it should be enabled at this point to restore the
     * post-initialization configuration.
     */

    if ((handler->original_flags & ACPI_GPE_DISPATCH_METHOD)
        && handler->originally_enabled)
        (void)acpi_ev_add_gpe_reference(gpe_event_info);

    /* Now we can free the handler object */

    ACPI_FREE(handler);

unlock_and_exit:
    acpi_os_release_lock(acpi_gbl_gpe_lock, flags);

    (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
    return_ACPI_STATUS(status);
}

ACPI_EXPORT_SYMBOL(acpi_remove_gpe_handler)

/*******************************************************************************
 *
 * FUNCTION:    acpi_acquire_global_lock
 *
 * PARAMETERS:  timeout         - How long the caller is willing to wait
 *              handle          - Where the handle to the lock is returned
 *                                (if acquired)
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Acquire the ACPI Global Lock
 *
 * Note: Allows callers with the same thread ID to acquire the global lock
 * multiple times. In other words, externally, the behavior of the global lock
 * is identical to an AML mutex. On the first acquire, a new handle is
 * returned. On any subsequent calls to acquire by the same thread, the same
 * handle is returned.
 *
 ******************************************************************************/
acpi_status acpi_acquire_global_lock(u16 timeout, u32 * handle)
{
    acpi_status status;

    if (!handle) {
        return (AE_BAD_PARAMETER);
    }

    /* Must lock interpreter to prevent race conditions */

    acpi_ex_enter_interpreter();

    status = acpi_ex_acquire_mutex_object(timeout,
                          acpi_gbl_global_lock_mutex,
                          acpi_os_get_thread_id());

    if (ACPI_SUCCESS(status)) {

        /* Return the global lock handle (updated in acpi_ev_acquire_global_lock) */

        *handle = acpi_gbl_global_lock_handle;
    }

    acpi_ex_exit_interpreter();
    return (status);
}

ACPI_EXPORT_SYMBOL(acpi_acquire_global_lock)

/*******************************************************************************
 *
 * FUNCTION:    acpi_release_global_lock
 *
 * PARAMETERS:  handle      - Returned from acpi_acquire_global_lock
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Release the ACPI Global Lock. The handle must be valid.
 *
 ******************************************************************************/
acpi_status acpi_release_global_lock(u32 handle)
{
    acpi_status status;

    if (!handle || (handle != acpi_gbl_global_lock_handle)) {
        return (AE_NOT_ACQUIRED);
    }

    status = acpi_ex_release_mutex_object(acpi_gbl_global_lock_mutex);
    return (status);
}

ACPI_EXPORT_SYMBOL(acpi_release_global_lock)
#endif              /* !ACPI_REDUCED_HARDWARE */