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/*
 * Copyright (c) 2009 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, 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 DAMAGE.
 */

/** @addtogroup generic
 * @{
 */
/**
 * @file
 * @brief Kernel event notifications.
 */

#include <ipc/event.h>
#include <ipc/event_types.h>
#include <mm/slab.h>
#include <arch/types.h>
#include <synch/spinlock.h>
#include <console/console.h>
#include <memstr.h>
#include <errno.h>
#include <arch.h>

/**
 * The events array.
 * Arranging the events in this two-dimensional array should decrease the
 * likelyhood of cacheline ping-pong.
 */
static event_t events[EVENT_END];

/** Initialize kernel events. */
void event_init(void)
{
    unsigned int i;
    
    for (i = 0; i < EVENT_END; i++) {
        spinlock_initialize(&events[i].lock, "event.lock");
        events[i].answerbox = NULL;
        events[i].counter = 0;
        events[i].method = 0;
    }
}

static int event_subscribe(event_type_t evno, unative_t method,
    answerbox_t *answerbox)
{
    if (evno >= EVENT_END)
        return ELIMIT;
    
    spinlock_lock(&events[evno].lock);
    
    int res;
    
    if (events[evno].answerbox == NULL) {
        events[evno].answerbox = answerbox;
        events[evno].method = method;
        events[evno].counter = 0;
        res = EOK;
    } else
        res = EEXISTS;
    
    spinlock_unlock(&events[evno].lock);
    
    return res;
}

unative_t sys_event_subscribe(unative_t evno, unative_t method)
{
    return (unative_t) event_subscribe((event_type_t) evno, (unative_t)
        method, &TASK->answerbox);
}

bool event_is_subscribed(event_type_t evno)
{
    bool res;
    
    ASSERT(evno < EVENT_END);
    
    spinlock_lock(&events[evno].lock);
    res = events[evno].answerbox != NULL;
    spinlock_unlock(&events[evno].lock);
    
    return res;
}


void event_cleanup_answerbox(answerbox_t *answerbox)
{
    unsigned int i;
    
    for (i = 0; i < EVENT_END; i++) {
        spinlock_lock(&events[i].lock);
        if (events[i].answerbox == answerbox) {
            events[i].answerbox = NULL;
            events[i].counter = 0;
            events[i].method = 0;
        }
        spinlock_unlock(&events[i].lock);
    }
}

void event_notify(event_type_t evno, unative_t a1, unative_t a2, unative_t a3,
    unative_t a4, unative_t a5)
{
    ASSERT(evno < EVENT_END);
    
    spinlock_lock(&events[evno].lock);
    if (events[evno].answerbox != NULL) {
        call_t *call = ipc_call_alloc(FRAME_ATOMIC);
        if (call) {
            call->flags |= IPC_CALL_NOTIF;
            call->priv = ++events[evno].counter;
            IPC_SET_METHOD(call->data, events[evno].method);
            IPC_SET_ARG1(call->data, a1);
            IPC_SET_ARG2(call->data, a2);
            IPC_SET_ARG3(call->data, a3);
            IPC_SET_ARG4(call->data, a4);
            IPC_SET_ARG5(call->data, a5);
            
            ipl_t ipl = interrupts_disable();
            spinlock_lock(&events[evno].answerbox->irq_lock);
            list_append(&call->link, &events[evno].answerbox->irq_notifs);
            spinlock_unlock(&events[evno].answerbox->irq_lock);
            interrupts_restore(ipl);
            
            waitq_wakeup(&events[evno].answerbox->wq, WAKEUP_FIRST);
        }
    }
    spinlock_unlock(&events[evno].lock);
}

/** @}
 */