/******************************************************************************
 *
 * Module Name: evmisc - Miscellaneous event manager support functions
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2011, 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 <acpi/acpi.h>
#include "accommon.h"
#include "acevents.h"
#include "acnamesp.h"
#include "acinterp.h"

#define _COMPONENT          ACPI_EVENTS
ACPI_MODULE_NAME("evmisc")

/* Local prototypes */
static void ACPI_SYSTEM_XFACE acpi_ev_notify_dispatch(void *context);

static u32 acpi_ev_global_lock_handler(void *context);

static acpi_status acpi_ev_remove_global_lock_handler(void);

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_is_notify_object
 *
 * PARAMETERS:  Node            - Node to check
 *
 * RETURN:      TRUE if notifies allowed on this object
 *
 * DESCRIPTION: Check type of node for a object that supports notifies.
 *
 *              TBD: This could be replaced by a flag bit in the node.
 *
 ******************************************************************************/

u8 acpi_ev_is_notify_object(struct acpi_namespace_node *node)
{
        switch (node->type) {
        case ACPI_TYPE_DEVICE:
        case ACPI_TYPE_PROCESSOR:
        case ACPI_TYPE_THERMAL:
                /*
                 * These are the ONLY objects that can receive ACPI notifications
                 */
                return (TRUE);

        default:
                return (FALSE);
        }
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_queue_notify_request
 *
 * PARAMETERS:  Node            - NS node for the notified object
 *              notify_value    - Value from the Notify() request
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Dispatch a device notification event to a previously
 *              installed handler.
 *
 ******************************************************************************/

acpi_status
acpi_ev_queue_notify_request(struct acpi_namespace_node * node,
                             u32 notify_value)
{
        union acpi_operand_object *obj_desc;
        union acpi_operand_object *handler_obj = NULL;
        union acpi_generic_state *notify_info;
        acpi_status status = AE_OK;

        ACPI_FUNCTION_NAME(ev_queue_notify_request);

        /*
         * For value 3 (Ejection Request), some device method may need to be run.
         * For value 2 (Device Wake) if _PRW exists, the _PS0 method may need
         *   to be run.
         * For value 0x80 (Status Change) on the power button or sleep button,
         *   initiate soft-off or sleep operation?
         */
        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                          "Dispatching Notify on [%4.4s] Node %p Value 0x%2.2X (%s)\n",
                          acpi_ut_get_node_name(node), node, notify_value,
                          acpi_ut_get_notify_name(notify_value)));

        /* Get the notify object attached to the NS Node */

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

                /* We have the notify object, Get the right handler */

                switch (node->type) {

                        /* Notify allowed only on these types */

                case ACPI_TYPE_DEVICE:
                case ACPI_TYPE_THERMAL:
                case ACPI_TYPE_PROCESSOR:

                        if (notify_value <= ACPI_MAX_SYS_NOTIFY) {
                                handler_obj =
                                    obj_desc->common_notify.system_notify;
                        } else {
                                handler_obj =
                                    obj_desc->common_notify.device_notify;
                        }
                        break;

                default:

                        /* All other types are not supported */

                        return (AE_TYPE);
                }
        }

        /*
         * If there is any handler to run, schedule the dispatcher.
         * Check for:
         * 1) Global system notify handler
         * 2) Global device notify handler
         * 3) Per-device notify handler
         */
        if ((acpi_gbl_system_notify.handler &&
             (notify_value <= ACPI_MAX_SYS_NOTIFY)) ||
            (acpi_gbl_device_notify.handler &&
             (notify_value > ACPI_MAX_SYS_NOTIFY)) || handler_obj) {
                notify_info = acpi_ut_create_generic_state();
                if (!notify_info) {
                        return (AE_NO_MEMORY);
                }

                if (!handler_obj) {
                        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                                          "Executing system notify handler for Notify (%4.4s, %X) "
                                          "node %p\n",
                                          acpi_ut_get_node_name(node),
                                          notify_value, node));
                }

                notify_info->common.descriptor_type =
                    ACPI_DESC_TYPE_STATE_NOTIFY;
                notify_info->notify.node = node;
                notify_info->notify.value = (u16) notify_value;
                notify_info->notify.handler_obj = handler_obj;

                status =
                    acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_ev_notify_dispatch,
                                    notify_info);
                if (ACPI_FAILURE(status)) {
                        acpi_ut_delete_generic_state(notify_info);
                }
        } else {
                /* There is no notify handler (per-device or system) for this device */

                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                                  "No notify handler for Notify (%4.4s, %X) node %p\n",
                                  acpi_ut_get_node_name(node), notify_value,
                                  node));
        }

        return (status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_notify_dispatch
 *
 * PARAMETERS:  Context         - To be passed to the notify handler
 *
 * RETURN:      None.
 *
 * DESCRIPTION: Dispatch a device notification event to a previously
 *              installed handler.
 *
 ******************************************************************************/

static void ACPI_SYSTEM_XFACE acpi_ev_notify_dispatch(void *context)
{
        union acpi_generic_state *notify_info =
            (union acpi_generic_state *)context;
        acpi_notify_handler global_handler = NULL;
        void *global_context = NULL;
        union acpi_operand_object *handler_obj;

        ACPI_FUNCTION_ENTRY();

        /*
         * We will invoke a global notify handler if installed. This is done
         * _before_ we invoke the per-device handler attached to the device.
         */
        if (notify_info->notify.value <= ACPI_MAX_SYS_NOTIFY) {

                /* Global system notification handler */

                if (acpi_gbl_system_notify.handler) {
                        global_handler = acpi_gbl_system_notify.handler;
                        global_context = acpi_gbl_system_notify.context;
                }
        } else {
                /* Global driver notification handler */

                if (acpi_gbl_device_notify.handler) {
                        global_handler = acpi_gbl_device_notify.handler;
                        global_context = acpi_gbl_device_notify.context;
                }
        }

        /* Invoke the system handler first, if present */

        if (global_handler) {
                global_handler(notify_info->notify.node,
                               notify_info->notify.value, global_context);
        }

        /* Now invoke the per-device handler, if present */

        handler_obj = notify_info->notify.handler_obj;
        if (handler_obj) {
                struct acpi_object_notify_handler *notifier;

                notifier = &handler_obj->notify;
                while (notifier) {
                        notifier->handler(notify_info->notify.node,
                                          notify_info->notify.value,
                                          notifier->context);
                        notifier = notifier->next;
                }
        }

        /* All done with the info object */

        acpi_ut_delete_generic_state(notify_info);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_global_lock_handler
 *
 * PARAMETERS:  Context         - From thread interface, not used
 *
 * RETURN:      ACPI_INTERRUPT_HANDLED
 *
 * DESCRIPTION: Invoked directly from the SCI handler when a global lock
 *              release interrupt occurs.  If there's a thread waiting for
 *              the global lock, signal it.
 *
 * NOTE: Assumes that the semaphore can be signaled from interrupt level. If
 * this is not possible for some reason, a separate thread will have to be
 * scheduled to do this.
 *
 ******************************************************************************/
static u8 acpi_ev_global_lock_pending;

static u32 acpi_ev_global_lock_handler(void *context)
{
        acpi_status status;
        acpi_cpu_flags flags;

        flags = acpi_os_acquire_lock(acpi_ev_global_lock_pending_lock);

        if (!acpi_ev_global_lock_pending) {
                goto out;
        }

        /* Send a unit to the semaphore */

        status = acpi_os_signal_semaphore(acpi_gbl_global_lock_semaphore, 1);
        if (ACPI_FAILURE(status)) {
                ACPI_ERROR((AE_INFO, "Could not signal Global Lock semaphore"));
        }

        acpi_ev_global_lock_pending = FALSE;

 out:
        acpi_os_release_lock(acpi_ev_global_lock_pending_lock, flags);

        return (ACPI_INTERRUPT_HANDLED);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_init_global_lock_handler
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Install a handler for the global lock release event
 *
 ******************************************************************************/

acpi_status acpi_ev_init_global_lock_handler(void)
{
        acpi_status status;

        ACPI_FUNCTION_TRACE(ev_init_global_lock_handler);

        /* Attempt installation of the global lock handler */

        status = acpi_install_fixed_event_handler(ACPI_EVENT_GLOBAL,
                                                  acpi_ev_global_lock_handler,
                                                  NULL);

        /*
         * If the global lock does not exist on this platform, the attempt to
         * enable GBL_STATUS will fail (the GBL_ENABLE bit will not stick).
         * Map to AE_OK, but mark global lock as not present. Any attempt to
         * actually use the global lock will be flagged with an error.
         */
        if (status == AE_NO_HARDWARE_RESPONSE) {
                ACPI_ERROR((AE_INFO,
                            "No response from Global Lock hardware, disabling lock"));

                acpi_gbl_global_lock_present = FALSE;
                return_ACPI_STATUS(AE_OK);
        }

        acpi_gbl_global_lock_present = TRUE;
        return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_remove_global_lock_handler
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Remove the handler for the Global Lock
 *
 ******************************************************************************/

static acpi_status acpi_ev_remove_global_lock_handler(void)
{
        acpi_status status;

        ACPI_FUNCTION_TRACE(ev_remove_global_lock_handler);

        acpi_gbl_global_lock_present = FALSE;
        status = acpi_remove_fixed_event_handler(ACPI_EVENT_GLOBAL,
                                                 acpi_ev_global_lock_handler);

        return_ACPI_STATUS(status);
}

/******************************************************************************
 *
 * FUNCTION:    acpi_ev_acquire_global_lock
 *
 * PARAMETERS:  Timeout         - Max time to wait for the lock, in millisec.
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Attempt to gain ownership of the Global Lock.
 *
 * MUTEX:       Interpreter must be locked
 *
 * Note: The original implementation allowed multiple threads to "acquire" the
 * Global Lock, and the OS would hold the lock until the last thread had
 * released it. However, this could potentially starve the BIOS out of the
 * lock, especially in the case where there is a tight handshake between the
 * Embedded Controller driver and the BIOS. Therefore, this implementation
 * allows only one thread to acquire the HW Global Lock at a time, and makes
 * the global lock appear as a standard mutex on the OS side.
 *
 *****************************************************************************/
static acpi_thread_id acpi_ev_global_lock_thread_id;
static int acpi_ev_global_lock_acquired;

acpi_status acpi_ev_acquire_global_lock(u16 timeout)
{
        acpi_cpu_flags flags;
        acpi_status status = AE_OK;
        u8 acquired = FALSE;

        ACPI_FUNCTION_TRACE(ev_acquire_global_lock);

        /*
         * Only one thread can acquire the GL at a time, the global_lock_mutex
         * enforces this. This interface releases the interpreter if we must wait.
         */
        status = acpi_ex_system_wait_mutex(
                        acpi_gbl_global_lock_mutex->mutex.os_mutex, 0);
        if (status == AE_TIME) {
                if (acpi_ev_global_lock_thread_id == acpi_os_get_thread_id()) {
                        acpi_ev_global_lock_acquired++;
                        return AE_OK;
                }
        }

        if (ACPI_FAILURE(status)) {
                status = acpi_ex_system_wait_mutex(
                                acpi_gbl_global_lock_mutex->mutex.os_mutex,
                                timeout);
        }
        if (ACPI_FAILURE(status)) {
                return_ACPI_STATUS(status);
        }

        acpi_ev_global_lock_thread_id = acpi_os_get_thread_id();
        acpi_ev_global_lock_acquired++;

        /*
         * Update the global lock handle and check for wraparound. The handle is
         * only used for the external global lock interfaces, but it is updated
         * here to properly handle the case where a single thread may acquire the
         * lock via both the AML and the acpi_acquire_global_lock interfaces. The
         * handle is therefore updated on the first acquire from a given thread
         * regardless of where the acquisition request originated.
         */
        acpi_gbl_global_lock_handle++;
        if (acpi_gbl_global_lock_handle == 0) {
                acpi_gbl_global_lock_handle = 1;
        }

        /*
         * Make sure that a global lock actually exists. If not, just treat the
         * lock as a standard mutex.
         */
        if (!acpi_gbl_global_lock_present) {
                acpi_gbl_global_lock_acquired = TRUE;
                return_ACPI_STATUS(AE_OK);
        }

        flags = acpi_os_acquire_lock(acpi_ev_global_lock_pending_lock);

        do {

                /* Attempt to acquire the actual hardware lock */

                ACPI_ACQUIRE_GLOBAL_LOCK(acpi_gbl_FACS, acquired);
                if (acquired) {
                        acpi_gbl_global_lock_acquired = TRUE;

                        ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
                                          "Acquired hardware Global Lock\n"));
                        break;
                }

                acpi_ev_global_lock_pending = TRUE;

                acpi_os_release_lock(acpi_ev_global_lock_pending_lock, flags);

                /*
                 * Did not get the lock. The pending bit was set above, and we
                 * must wait until we get the global lock released interrupt.
                 */
                ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
                                  "Waiting for hardware Global Lock\n"));

                /*
                 * Wait for handshake with the global lock interrupt handler.
                 * This interface releases the interpreter if we must wait.
                 */
                status = acpi_ex_system_wait_semaphore(
                                                acpi_gbl_global_lock_semaphore,
                                                ACPI_WAIT_FOREVER);

                flags = acpi_os_acquire_lock(acpi_ev_global_lock_pending_lock);

        } while (ACPI_SUCCESS(status));

        acpi_ev_global_lock_pending = FALSE;

        acpi_os_release_lock(acpi_ev_global_lock_pending_lock, flags);

        return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_release_global_lock
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Releases ownership of the Global Lock.
 *
 ******************************************************************************/

acpi_status acpi_ev_release_global_lock(void)
{
        u8 pending = FALSE;
        acpi_status status = AE_OK;

        ACPI_FUNCTION_TRACE(ev_release_global_lock);

        /* Lock must be already acquired */

        if (!acpi_gbl_global_lock_acquired) {
                ACPI_WARNING((AE_INFO,
                              "Cannot release the ACPI Global Lock, it has not been acquired"));
                return_ACPI_STATUS(AE_NOT_ACQUIRED);
        }

        acpi_ev_global_lock_acquired--;
        if (acpi_ev_global_lock_acquired > 0) {
                return AE_OK;
        }

        if (acpi_gbl_global_lock_present) {

                /* Allow any thread to release the lock */

                ACPI_RELEASE_GLOBAL_LOCK(acpi_gbl_FACS, pending);

                /*
                 * If the pending bit was set, we must write GBL_RLS to the control
                 * register
                 */
                if (pending) {
                        status =
                            acpi_write_bit_register
                            (ACPI_BITREG_GLOBAL_LOCK_RELEASE,
                             ACPI_ENABLE_EVENT);
                }

                ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
                                  "Released hardware Global Lock\n"));
        }

        acpi_gbl_global_lock_acquired = FALSE;

        /* Release the local GL mutex */
        acpi_ev_global_lock_thread_id = 0;
        acpi_ev_global_lock_acquired = 0;
        acpi_os_release_mutex(acpi_gbl_global_lock_mutex->mutex.os_mutex);
        return_ACPI_STATUS(status);
}

/******************************************************************************
 *
 * FUNCTION:    acpi_ev_terminate
 *
 * PARAMETERS:  none
 *
 * RETURN:      none
 *
 * DESCRIPTION: Disable events and free memory allocated for table storage.
 *
 ******************************************************************************/

void acpi_ev_terminate(void)
{
        u32 i;
        acpi_status status;

        ACPI_FUNCTION_TRACE(ev_terminate);

        if (acpi_gbl_events_initialized) {
                /*
                 * Disable all event-related functionality. In all cases, on error,
                 * print a message but obviously we don't abort.
                 */

                /* Disable all fixed events */

                for (i = 0; i < ACPI_NUM_FIXED_EVENTS; i++) {
                        status = acpi_disable_event(i, 0);
                        if (ACPI_FAILURE(status)) {
                                ACPI_ERROR((AE_INFO,
                                            "Could not disable fixed event %u",
                                            (u32) i));
                        }
                }

                /* Disable all GPEs in all GPE blocks */

                status = acpi_ev_walk_gpe_list(acpi_hw_disable_gpe_block, NULL);

                /* Remove SCI handler */

                status = acpi_ev_remove_sci_handler();
                if (ACPI_FAILURE(status)) {
                        ACPI_ERROR((AE_INFO, "Could not remove SCI handler"));
                }

                status = acpi_ev_remove_global_lock_handler();
                if (ACPI_FAILURE(status)) {
                        ACPI_ERROR((AE_INFO,
                                    "Could not remove Global Lock handler"));
                }
        }

        /* Deallocate all handler objects installed within GPE info structs */

        status = acpi_ev_walk_gpe_list(acpi_ev_delete_gpe_handlers, NULL);

        /* Return to original mode if necessary */

        if (acpi_gbl_original_mode == ACPI_SYS_MODE_LEGACY) {
                status = acpi_disable();
                if (ACPI_FAILURE(status)) {
                        ACPI_WARNING((AE_INFO, "AcpiDisable failed"));
                }
        }
        return_VOID;
}