WebSVN – HelenOS – Diff – /tags/0.4.1/kernel/generic/src/ipc/ipc.c


/*
 * Copyright (c) 2006 Ondrej Palkovsky
 * 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 genericipc
 * @{
 */
/** @file
 */
 
/* Lock ordering
 *
 * First the answerbox, then the phone.
 */
 
#include <synch/synch.h>
#include <synch/spinlock.h>
#include <synch/mutex.h>
#include <synch/waitq.h>
#include <synch/synch.h>
#include <ipc/ipc.h>
#include <ipc/kbox.h>
#include <ipc/event.h>
#include <errno.h>
#include <mm/slab.h>
#include <arch.h>
#include <proc/task.h>
#include <memstr.h>
#include <debug.h>
#include <print.h>
#include <console/console.h>
#include <proc/thread.h>
#include <arch/interrupt.h>
#include <ipc/irq.h>
 
/** Open channel that is assigned automatically to new tasks */
answerbox_t *ipc_phone_0 = NULL;
 
static slab_cache_t *ipc_call_slab;
 
/** Initialize a call structure.
 *
 * @param call      Call structure to be initialized.
 */
static void _ipc_call_init(call_t *call)
{
    memsetb(call, sizeof(*call), 0);
    call->callerbox = &TASK->answerbox;
    call->sender = TASK;
    call->buffer = NULL;
}
 
/** Allocate and initialize a call structure.
 *
 * The call is initialized, so that the reply will be directed to
 * TASK->answerbox.
 *
 * @param flags     Parameters for slab_alloc (e.g FRAME_ATOMIC).
 *
 * @return      If flags permit it, return NULL, or initialized kernel
 *          call structure.
 */
call_t *ipc_call_alloc(int flags)
{
    call_t *call;
 
    call = slab_alloc(ipc_call_slab, flags);
    if (call)
        _ipc_call_init(call);
 
    return call;
}
 
/** Initialize a statically allocated call structure.
 *
 * @param call      Statically allocated kernel call structure to be
 *          initialized.
 */
void ipc_call_static_init(call_t *call)
{
    _ipc_call_init(call);
    call->flags |= IPC_CALL_STATIC_ALLOC;
}
 
/** Deallocate a call structure.
 *
 * @param call      Call structure to be freed.
 */
void ipc_call_free(call_t *call)
{
    ASSERT(!(call->flags & IPC_CALL_STATIC_ALLOC));
    /* Check to see if we have data in the IPC_M_DATA_SEND buffer. */
    if (call->buffer)
        free(call->buffer);
    slab_free(ipc_call_slab, call);
}
 
/** Initialize an answerbox structure.
 *
 * @param box       Answerbox structure to be initialized.
 * @param task      Task to which the answerbox belongs.
 */
void ipc_answerbox_init(answerbox_t *box, task_t *task)
{
    spinlock_initialize(&box->lock, "ipc_box_lock");
    spinlock_initialize(&box->irq_lock, "ipc_box_irqlock");
    waitq_initialize(&box->wq);
    list_initialize(&box->connected_phones);
    list_initialize(&box->calls);
    list_initialize(&box->dispatched_calls);
    list_initialize(&box->answers);
    list_initialize(&box->irq_notifs);
    list_initialize(&box->irq_head);
    box->task = task;
}
 
/** Connect a phone to an answerbox.
 *
 * @param phone     Initialized phone structure.
 * @param box       Initialized answerbox structure.
 */
void ipc_phone_connect(phone_t *phone, answerbox_t *box)
{
    mutex_lock(&phone->lock);
 
    phone->state = IPC_PHONE_CONNECTED;
    phone->callee = box;
 
    spinlock_lock(&box->lock);
    list_append(&phone->link, &box->connected_phones);
    spinlock_unlock(&box->lock);
 
    mutex_unlock(&phone->lock);
}
 
/** Initialize a phone structure.
 *
 * @param phone     Phone structure to be initialized.
 */
void ipc_phone_init(phone_t *phone)
{
    mutex_initialize(&phone->lock, MUTEX_PASSIVE);
    phone->callee = NULL;
    phone->state = IPC_PHONE_FREE;
    atomic_set(&phone->active_calls, 0);
}
 
/** Helper function to facilitate synchronous calls.
 *
 * @param phone     Destination kernel phone structure.
 * @param request   Call structure with request.
 *
 * @return      EOK on success or EINTR if the sleep was interrupted.
 */
int ipc_call_sync(phone_t *phone, call_t *request)
{
    answerbox_t sync_box;
 
    ipc_answerbox_init(&sync_box, TASK);
 
    /* We will receive data in a special box. */
    request->callerbox = &sync_box;
 
    ipc_call(phone, request);
    if (!ipc_wait_for_call(&sync_box, SYNCH_NO_TIMEOUT,
        SYNCH_FLAGS_INTERRUPTIBLE))
        return EINTR;
    return EOK;
}
 
/** Answer a message which was not dispatched and is not listed in any queue.
 *
 * @param call      Call structure to be answered.
 */
static void _ipc_answer_free_call(call_t *call)
{
    answerbox_t *callerbox = call->callerbox;
 
    call->flags |= IPC_CALL_ANSWERED;
 
    if (call->flags & IPC_CALL_FORWARDED) {
        if (call->caller_phone) {
            /* Demasquerade the caller phone. */
            call->data.phone = call->caller_phone;
        }
    }
 
    spinlock_lock(&callerbox->lock);
    list_append(&call->link, &callerbox->answers);
    spinlock_unlock(&callerbox->lock);
    waitq_wakeup(&callerbox->wq, WAKEUP_FIRST);
}
 
/** Answer a message which is in a callee queue.
 *
 * @param box       Answerbox that is answering the message.
 * @param call      Modified request that is being sent back.
 */
void ipc_answer(answerbox_t *box, call_t *call)
{
    /* Remove from active box */
    spinlock_lock(&box->lock);
    list_remove(&call->link);
    spinlock_unlock(&box->lock);
    /* Send back answer */
    _ipc_answer_free_call(call);
}
 
/** Simulate sending back a message.
 *
 * Most errors are better handled by forming a normal backward
 * message and sending it as a normal answer.
 *
 * @param phone     Phone structure the call should appear to come from.
 * @param call      Call structure to be answered.
 * @param err       Return value to be used for the answer.
 */
void ipc_backsend_err(phone_t *phone, call_t *call, unative_t err)
{
    call->data.phone = phone;
    atomic_inc(&phone->active_calls);
    IPC_SET_RETVAL(call->data, err);
    _ipc_answer_free_call(call);
}
 
/** Unsafe unchecking version of ipc_call.
 *
 * @param phone     Phone structure the call comes from.
 * @param box       Destination answerbox structure.
 * @param call      Call structure with request.
 */
static void _ipc_call(phone_t *phone, answerbox_t *box, call_t *call)
{
    if (!(call->flags & IPC_CALL_FORWARDED)) {
        atomic_inc(&phone->active_calls);
        call->data.phone = phone;
    }
 
    spinlock_lock(&box->lock);
    list_append(&call->link, &box->calls);
    spinlock_unlock(&box->lock);
    waitq_wakeup(&box->wq, WAKEUP_FIRST);
}
 
/** Send an asynchronous request using a phone to an answerbox.
 *
 * @param phone     Phone structure the call comes from and which is
 *          connected to the destination answerbox.
 * @param call      Call structure with request.
 *
 * @return      Return 0 on success, ENOENT on error.
 */
int ipc_call(phone_t *phone, call_t *call)
{
    answerbox_t *box;
 
    mutex_lock(&phone->lock);
    if (phone->state != IPC_PHONE_CONNECTED) {
        mutex_unlock(&phone->lock);
        if (call->flags & IPC_CALL_FORWARDED) {
            IPC_SET_RETVAL(call->data, EFORWARD);
            _ipc_answer_free_call(call);
        } else {
            if (phone->state == IPC_PHONE_HUNGUP)
                ipc_backsend_err(phone, call, EHANGUP);
            else
                ipc_backsend_err(phone, call, ENOENT);
        }
        return ENOENT;
    }
    box = phone->callee;
    _ipc_call(phone, box, call);
   
    mutex_unlock(&phone->lock);
    return 0;
}
 
/** Disconnect phone from answerbox.
 *
 * This call leaves the phone in the HUNGUP state. The change to 'free' is done
 * lazily later.
 *
 * @param phone     Phone structure to be hung up.
 *              
 * @return      Return 0 if the phone is disconnected.
 *          Return -1 if the phone was already disconnected.
 */
int ipc_phone_hangup(phone_t *phone)
{
    answerbox_t *box;
    call_t *call;
   
    mutex_lock(&phone->lock);
    if (phone->state == IPC_PHONE_FREE ||
        phone->state == IPC_PHONE_HUNGUP ||
        phone->state == IPC_PHONE_CONNECTING) {
        mutex_unlock(&phone->lock);
        return -1;
    }
    box = phone->callee;
    if (phone->state != IPC_PHONE_SLAMMED) {
        /* Remove myself from answerbox */
        spinlock_lock(&box->lock);
        list_remove(&phone->link);
        spinlock_unlock(&box->lock);
 
        call = ipc_call_alloc(0);
        IPC_SET_METHOD(call->data, IPC_M_PHONE_HUNGUP);
        call->flags |= IPC_CALL_DISCARD_ANSWER;
        _ipc_call(phone, box, call);
    }
 
    phone->state = IPC_PHONE_HUNGUP;
    mutex_unlock(&phone->lock);
 
    return 0;
}
 
/** Forwards call from one answerbox to another one.
 *
 * @param call      Call structure to be redirected.
 * @param newphone  Phone structure to target answerbox.
 * @param oldbox    Old answerbox structure.
 * @param mode      Flags that specify mode of the forward operation.
 *
 * @return      Return 0 if forwarding succeeded or an error code if
 *          there was error.
 *
 * The return value serves only as an information for the forwarder,
 * the original caller is notified automatically with EFORWARD.
 */
int ipc_forward(call_t *call, phone_t *newphone, answerbox_t *oldbox, int mode)
{
    spinlock_lock(&oldbox->lock);
    list_remove(&call->link);
    spinlock_unlock(&oldbox->lock);
 
    if (mode & IPC_FF_ROUTE_FROM_ME) {
        if (!call->caller_phone)
            call->caller_phone = call->data.phone;
        call->data.phone = newphone;
    }
 
    return ipc_call(newphone, call);
}
 
 
/** Wait for a phone call.
 *
 * @param box       Answerbox expecting the call.
 * @param usec      Timeout in microseconds. See documentation for
 *          waitq_sleep_timeout() for decription of its special
 *          meaning.
 * @param flags     Select mode of sleep operation. See documentation for
 *          waitq_sleep_timeout() for description of its special
 *          meaning.
 * @return      Recived call structure or NULL.
 *
 * To distinguish between a call and an answer, have a look at call->flags.
 */
call_t *ipc_wait_for_call(answerbox_t *box, uint32_t usec, int flags)
{
    call_t *request;
    ipl_t ipl;
    int rc;
 
restart:
    rc = waitq_sleep_timeout(&box->wq, usec, flags);
    if (SYNCH_FAILED(rc))
        return NULL;
   
    spinlock_lock(&box->lock);
    if (!list_empty(&box->irq_notifs)) {
        ipl = interrupts_disable();
        spinlock_lock(&box->irq_lock);
 
        request = list_get_instance(box->irq_notifs.next, call_t, link);
        list_remove(&request->link);
 
        spinlock_unlock(&box->irq_lock);
        interrupts_restore(ipl);
    } else if (!list_empty(&box->answers)) {
        /* Handle asynchronous answers */
        request = list_get_instance(box->answers.next, call_t, link);
        list_remove(&request->link);
        atomic_dec(&request->data.phone->active_calls);
    } else if (!list_empty(&box->calls)) {
        /* Handle requests */
        request = list_get_instance(box->calls.next, call_t, link);
        list_remove(&request->link);
        /* Append request to dispatch queue */
        list_append(&request->link, &box->dispatched_calls);
    } else {
        /* This can happen regularly after ipc_cleanup */
        spinlock_unlock(&box->lock);
        goto restart;
    }
    spinlock_unlock(&box->lock);
    return request;
}
 
/** Answer all calls from list with EHANGUP answer.
 *
 * @param lst       Head of the list to be cleaned up.
 */
void ipc_cleanup_call_list(link_t *lst)
{
    call_t *call;
 
    while (!list_empty(lst)) {
        call = list_get_instance(lst->next, call_t, link);
        if (call->buffer)
            free(call->buffer);
        list_remove(&call->link);
 
        IPC_SET_RETVAL(call->data, EHANGUP);
        _ipc_answer_free_call(call);
    }
}
 
/** Disconnects all phones connected to an answerbox.
 *
 * @param box       Answerbox to disconnect phones from.
 * @param notify_box    If true, the answerbox will get a hangup message for
 *          each disconnected phone.
 */
void ipc_answerbox_slam_phones(answerbox_t *box, bool notify_box)
{
    phone_t *phone;
    DEADLOCK_PROBE_INIT(p_phonelck);
    ipl_t ipl;
    call_t *call;
 
    call = notify_box ? ipc_call_alloc(0) : NULL;
 
    /* Disconnect all phones connected to our answerbox */
restart_phones:
    ipl = interrupts_disable();
    spinlock_lock(&box->lock);
    while (!list_empty(&box->connected_phones)) {
        phone = list_get_instance(box->connected_phones.next,
            phone_t, link);
        if (SYNCH_FAILED(mutex_trylock(&phone->lock))) {
            spinlock_unlock(&box->lock);
            interrupts_restore(ipl);
            DEADLOCK_PROBE(p_phonelck, DEADLOCK_THRESHOLD);
            goto restart_phones;
        }
       
        /* Disconnect phone */
        ASSERT(phone->state == IPC_PHONE_CONNECTED);
 
        list_remove(&phone->link);
        phone->state = IPC_PHONE_SLAMMED;
 
        if (notify_box) {
            mutex_unlock(&phone->lock);
            spinlock_unlock(&box->lock);
            interrupts_restore(ipl);
 
            /*
             * Send one message to the answerbox for each
             * phone. Used to make sure the kbox thread
             * wakes up after the last phone has been
             * disconnected.
             */
            IPC_SET_METHOD(call->data, IPC_M_PHONE_HUNGUP);
            call->flags |= IPC_CALL_DISCARD_ANSWER;
            _ipc_call(phone, box, call);
 
            /* Allocate another call in advance */
            call = ipc_call_alloc(0);
 
            /* Must start again */
            goto restart_phones;
        }
 
        mutex_unlock(&phone->lock);
    }
 
    spinlock_unlock(&box->lock);
    interrupts_restore(ipl);
 
    /* Free unused call */
    if (call)
        ipc_call_free(call);
}
 
/** Cleans up all IPC communication of the current task.
 *
 * Note: ipc_hangup sets returning answerbox to TASK->answerbox, you
 * have to change it as well if you want to cleanup other tasks than TASK.
 */
void ipc_cleanup(void)
{
    int i;
    call_t *call;
 
    /* Disconnect all our phones ('ipc_phone_hangup') */
    for (i = 0; i < IPC_MAX_PHONES; i++)
        ipc_phone_hangup(&TASK->phones[i]);
 
    /* Unsubscribe from any event notifications. */
    event_cleanup_answerbox(&TASK->answerbox);
 
    /* Disconnect all connected irqs */
    ipc_irq_cleanup(&TASK->answerbox);
 
    /* Disconnect all phones connected to our regular answerbox */
    ipc_answerbox_slam_phones(&TASK->answerbox, false);
 
#ifdef CONFIG_UDEBUG
    /* Clean up kbox thread and communications */
    ipc_kbox_cleanup();
#endif
 
    /* Answer all messages in 'calls' and 'dispatched_calls' queues */
    spinlock_lock(&TASK->answerbox.lock);
    ipc_cleanup_call_list(&TASK->answerbox.dispatched_calls);
    ipc_cleanup_call_list(&TASK->answerbox.calls);
    spinlock_unlock(&TASK->answerbox.lock);
   
    /* Wait for all async answers to arrive */
    while (1) {
        /* Go through all phones, until all are FREE... */
        /* Locking not needed, no one else should modify
         * it, when we are in cleanup */
        for (i = 0; i < IPC_MAX_PHONES; i++) {
            if (TASK->phones[i].state == IPC_PHONE_HUNGUP &&
                atomic_get(&TASK->phones[i].active_calls) == 0)
                TASK->phones[i].state = IPC_PHONE_FREE;
           
            /* Just for sure, we might have had some
             * IPC_PHONE_CONNECTING phones */
            if (TASK->phones[i].state == IPC_PHONE_CONNECTED)
                ipc_phone_hangup(&TASK->phones[i]);
            /* If the hangup succeeded, it has sent a HANGUP
             * message, the IPC is now in HUNGUP state, we
             * wait for the reply to come */
           
            if (TASK->phones[i].state != IPC_PHONE_FREE)
                break;
        }
        /* Voila, got into cleanup */
        if (i == IPC_MAX_PHONES)
            break;
       
        call = ipc_wait_for_call(&TASK->answerbox, SYNCH_NO_TIMEOUT,
            SYNCH_FLAGS_NONE);
        ASSERT((call->flags & IPC_CALL_ANSWERED) ||
            (call->flags & IPC_CALL_NOTIF));
        ASSERT(!(call->flags & IPC_CALL_STATIC_ALLOC));
       
        /*
         * Record the receipt of this call in the current task's counter
         * of active calls. IPC_M_PHONE_HUNGUP calls do not contribute
         * to this counter so do not record answers to them either.
         */
        if (!(call->flags & IPC_CALL_DISCARD_ANSWER))
            atomic_dec(&TASK->active_calls);
        ipc_call_free(call);
    }
}
 
 
/** Initilize IPC subsystem */
void ipc_init(void)
{
    ipc_call_slab = slab_cache_create("ipc_call", sizeof(call_t), 0, NULL,
        NULL, 0);
}
 
 
/** List answerbox contents.
 *
 * @param taskid    Task ID.
 */
void ipc_print_task(task_id_t taskid)
{
    task_t *task;
    int i;
    call_t *call;
    link_t *tmp;
   
    spinlock_lock(&tasks_lock);
    task = task_find_by_id(taskid);
    if (task)
        spinlock_lock(&task->lock);
    spinlock_unlock(&tasks_lock);
    if (!task)
        return;
 
    /* Print opened phones & details */
    printf("PHONE:\n");
    for (i = 0; i < IPC_MAX_PHONES; i++) {
        if (SYNCH_FAILED(mutex_trylock(&task->phones[i].lock))) {
            printf("%d: mutex busy\n", i);
            continue;
        }
        if (task->phones[i].state != IPC_PHONE_FREE) {
            printf("%d: ", i);
            switch (task->phones[i].state) {
            case IPC_PHONE_CONNECTING:
                printf("connecting ");
                break;
            case IPC_PHONE_CONNECTED:
                printf("connected to: %p ",
                       task->phones[i].callee);
                break;
            case IPC_PHONE_SLAMMED:
                printf("slammed by: %p ",
                       task->phones[i].callee);
                break;
            case IPC_PHONE_HUNGUP:
                printf("hung up - was: %p ",
                       task->phones[i].callee);
                break;
            default:
                break;
            }
            printf("active: %ld\n",
                atomic_get(&task->phones[i].active_calls));
        }
        mutex_unlock(&task->phones[i].lock);
    }
 
 
    /* Print answerbox - calls */
    spinlock_lock(&task->answerbox.lock);
    printf("ABOX - CALLS:\n");
    for (tmp = task->answerbox.calls.next; tmp != &task->answerbox.calls;
        tmp = tmp->next) {
        call = list_get_instance(tmp, call_t, link);
        printf("Callid: %p Srctask:%" PRIu64 " M:%" PRIun
            " A1:%" PRIun " A2:%" PRIun " A3:%" PRIun
            " A4:%" PRIun " A5:%" PRIun " Flags:%x\n", call,
            call->sender->taskid,
            IPC_GET_METHOD(call->data), IPC_GET_ARG1(call->data),
            IPC_GET_ARG2(call->data), IPC_GET_ARG3(call->data),
            IPC_GET_ARG4(call->data), IPC_GET_ARG5(call->data),
            call->flags);
    }
    /* Print answerbox - calls */
    printf("ABOX - DISPATCHED CALLS:\n");
    for (tmp = task->answerbox.dispatched_calls.next;
        tmp != &task->answerbox.dispatched_calls;
        tmp = tmp->next) {
        call = list_get_instance(tmp, call_t, link);
        printf("Callid: %p Srctask:%" PRIu64 " M:%" PRIun
            " A1:%" PRIun " A2:%" PRIun " A3:%" PRIun
            " A4:%" PRIun " A5:%" PRIun " Flags:%x\n", call,
            call->sender->taskid,
            IPC_GET_METHOD(call->data), IPC_GET_ARG1(call->data),
            IPC_GET_ARG2(call->data), IPC_GET_ARG3(call->data),
            IPC_GET_ARG4(call->data), IPC_GET_ARG5(call->data),
            call->flags);
    }
    /* Print answerbox - calls */
    printf("ABOX - ANSWERS:\n");
    for (tmp = task->answerbox.answers.next;
        tmp != &task->answerbox.answers;
        tmp = tmp->next) {
        call = list_get_instance(tmp, call_t, link);
        printf("Callid:%p M:%" PRIun " A1:%" PRIun " A2:%" PRIun
            " A3:%" PRIun " A4:%" PRIun " A5:%" PRIun " Flags:%x\n",
            call, IPC_GET_METHOD(call->data), IPC_GET_ARG1(call->data),
            IPC_GET_ARG2(call->data), IPC_GET_ARG3(call->data),
            IPC_GET_ARG4(call->data), IPC_GET_ARG5(call->data),
            call->flags);
    }
 
    spinlock_unlock(&task->answerbox.lock);
    spinlock_unlock(&task->lock);
}
 
/** @}
 */
 

Rev 4405	Rev 4687
1	/*	1	/*
2	* Copyright (c) 2006 Ondrej Palkovsky	2	* Copyright (c) 2006 Ondrej Palkovsky
3	* All rights reserved.	3	* All rights reserved.
4	*	4	*
5	* Redistribution and use in source and binary forms, with or without	5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions	6	* modification, are permitted provided that the following conditions
7	* are met:	7	* are met:
8	*	8	*
9	* - Redistributions of source code must retain the above copyright	9	* - Redistributions of source code must retain the above copyright
10	* notice, this list of conditions and the following disclaimer.	10	* notice, this list of conditions and the following disclaimer.
11	* - Redistributions in binary form must reproduce the above copyright	11	* - Redistributions in binary form must reproduce the above copyright
12	* notice, this list of conditions and the following disclaimer in the	12	* notice, this list of conditions and the following disclaimer in the
13	* documentation and/or other materials provided with the distribution.	13	* documentation and/or other materials provided with the distribution.
14	* - The name of the author may not be used to endorse or promote products	14	* - The name of the author may not be used to endorse or promote products
15	* derived from this software without specific prior written permission.	15	* derived from this software without specific prior written permission.
16	*	16	*
17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27	*/	27	*/
28		28
29	/** @addtogroup genericipc	29	/** @addtogroup genericipc
30	* @{	30	* @{
31	*/	31	*/
32	/** @file	32	/** @file
33	*/	33	*/
34		34
35	/* Lock ordering	35	/* Lock ordering
36	*	36	*
37	* First the answerbox, then the phone.	37	* First the answerbox, then the phone.
38	*/	38	*/
39		39
40	#include <synch/synch.h>	40	#include <synch/synch.h>
41	#include <synch/spinlock.h>	41	#include <synch/spinlock.h>
42	#include <synch/mutex.h>	42	#include <synch/mutex.h>
43	#include <synch/waitq.h>	43	#include <synch/waitq.h>
44	#include <synch/synch.h>	44	#include <synch/synch.h>
45	#include <ipc/ipc.h>	45	#include <ipc/ipc.h>
46	#include <ipc/kbox.h>	46	#include <ipc/kbox.h>
47	#include <ipc/event.h>	47	#include <ipc/event.h>
48	#include <errno.h>	48	#include <errno.h>
49	#include <mm/slab.h>	49	#include <mm/slab.h>
50	#include <arch.h>	50	#include <arch.h>
51	#include <proc/task.h>	51	#include <proc/task.h>
52	#include <memstr.h>	52	#include <memstr.h>
53	#include <debug.h>	53	#include <debug.h>
54	#include <print.h>	54	#include <print.h>
55	#include <console/console.h>	55	#include <console/console.h>
56	#include <proc/thread.h>	56	#include <proc/thread.h>
57	#include <arch/interrupt.h>	57	#include <arch/interrupt.h>
58	#include <ipc/irq.h>	58	#include <ipc/irq.h>
59		59
60	/** Open channel that is assigned automatically to new tasks */	60	/** Open channel that is assigned automatically to new tasks */
61	answerbox_t *ipc_phone_0 = NULL;	61	answerbox_t *ipc_phone_0 = NULL;
62		62
63	static slab_cache_t *ipc_call_slab;	63	static slab_cache_t *ipc_call_slab;
64		64
65	/** Initialize a call structure.	65	/** Initialize a call structure.
66	*	66	*
67	* @param call Call structure to be initialized.	67	* @param call Call structure to be initialized.
68	*/	68	*/
69	static void _ipc_call_init(call_t *call)	69	static void _ipc_call_init(call_t *call)
70	{	70	{
71	memsetb(call, sizeof(*call), 0);	71	memsetb(call, sizeof(*call), 0);
72	call->callerbox = &TASK->answerbox;	72	call->callerbox = &TASK->answerbox;
73	call->sender = TASK;	73	call->sender = TASK;
74	call->buffer = NULL;	74	call->buffer = NULL;
75	}	75	}
76		76
77	/** Allocate and initialize a call structure.	77	/** Allocate and initialize a call structure.
78	*	78	*
79	* The call is initialized, so that the reply will be directed to	79	* The call is initialized, so that the reply will be directed to
80	* TASK->answerbox.	80	* TASK->answerbox.
81	*	81	*
82	* @param flags Parameters for slab_alloc (e.g FRAME_ATOMIC).	82	* @param flags Parameters for slab_alloc (e.g FRAME_ATOMIC).
83	*	83	*
84	* @return If flags permit it, return NULL, or initialized kernel	84	* @return If flags permit it, return NULL, or initialized kernel
85	* call structure.	85	* call structure.
86	*/	86	*/
87	call_t *ipc_call_alloc(int flags)	87	call_t *ipc_call_alloc(int flags)
88	{	88	{
89	call_t *call;	89	call_t *call;
90		90
91	call = slab_alloc(ipc_call_slab, flags);	91	call = slab_alloc(ipc_call_slab, flags);
92	if (call)	92	if (call)
93	_ipc_call_init(call);	93	_ipc_call_init(call);
94		94
95	return call;	95	return call;
96	}	96	}
97		97
98	/** Initialize a statically allocated call structure.	98	/** Initialize a statically allocated call structure.
99	*	99	*
100	* @param call Statically allocated kernel call structure to be	100	* @param call Statically allocated kernel call structure to be
101	* initialized.	101	* initialized.
102	*/	102	*/
103	void ipc_call_static_init(call_t *call)	103	void ipc_call_static_init(call_t *call)
104	{	104	{
105	_ipc_call_init(call);	105	_ipc_call_init(call);
106	call->flags \|= IPC_CALL_STATIC_ALLOC;	106	call->flags \|= IPC_CALL_STATIC_ALLOC;
107	}	107	}
108		108
109	/** Deallocate a call structure.	109	/** Deallocate a call structure.
110	*	110	*
111	* @param call Call structure to be freed.	111	* @param call Call structure to be freed.
112	*/	112	*/
113	void ipc_call_free(call_t *call)	113	void ipc_call_free(call_t *call)
114	{	114	{
115	ASSERT(!(call->flags & IPC_CALL_STATIC_ALLOC));	115	ASSERT(!(call->flags & IPC_CALL_STATIC_ALLOC));
116	/* Check to see if we have data in the IPC_M_DATA_SEND buffer. */	116	/* Check to see if we have data in the IPC_M_DATA_SEND buffer. */
117	if (call->buffer)	117	if (call->buffer)
118	free(call->buffer);	118	free(call->buffer);
119	slab_free(ipc_call_slab, call);	119	slab_free(ipc_call_slab, call);
120	}	120	}
121		121
122	/** Initialize an answerbox structure.	122	/** Initialize an answerbox structure.
123	*	123	*
124	* @param box Answerbox structure to be initialized.	124	* @param box Answerbox structure to be initialized.
125	* @param task Task to which the answerbox belongs.	125	* @param task Task to which the answerbox belongs.
126	*/	126	*/
127	void ipc_answerbox_init(answerbox_t box, task_t task)	127	void ipc_answerbox_init(answerbox_t box, task_t task)
128	{	128	{
129	spinlock_initialize(&box->lock, "ipc_box_lock");	129	spinlock_initialize(&box->lock, "ipc_box_lock");
130	spinlock_initialize(&box->irq_lock, "ipc_box_irqlock");	130	spinlock_initialize(&box->irq_lock, "ipc_box_irqlock");
131	waitq_initialize(&box->wq);	131	waitq_initialize(&box->wq);
132	list_initialize(&box->connected_phones);	132	list_initialize(&box->connected_phones);
133	list_initialize(&box->calls);	133	list_initialize(&box->calls);
134	list_initialize(&box->dispatched_calls);	134	list_initialize(&box->dispatched_calls);
135	list_initialize(&box->answers);	135	list_initialize(&box->answers);
136	list_initialize(&box->irq_notifs);	136	list_initialize(&box->irq_notifs);
137	list_initialize(&box->irq_head);	137	list_initialize(&box->irq_head);
138	box->task = task;	138	box->task = task;
139	}	139	}
140		140
141	/** Connect a phone to an answerbox.	141	/** Connect a phone to an answerbox.
142	*	142	*
143	* @param phone Initialized phone structure.	143	* @param phone Initialized phone structure.
144	* @param box Initialized answerbox structure.	144	* @param box Initialized answerbox structure.
145	*/	145	*/
146	void ipc_phone_connect(phone_t phone, answerbox_t box)	146	void ipc_phone_connect(phone_t phone, answerbox_t box)
147	{	147	{
148	mutex_lock(&phone->lock);	148	mutex_lock(&phone->lock);
149		149
150	phone->state = IPC_PHONE_CONNECTED;	150	phone->state = IPC_PHONE_CONNECTED;
151	phone->callee = box;	151	phone->callee = box;
152		152
153	spinlock_lock(&box->lock);	153	spinlock_lock(&box->lock);
154	list_append(&phone->link, &box->connected_phones);	154	list_append(&phone->link, &box->connected_phones);
155	spinlock_unlock(&box->lock);	155	spinlock_unlock(&box->lock);
156		156
157	mutex_unlock(&phone->lock);	157	mutex_unlock(&phone->lock);
158	}	158	}
159		159
160	/** Initialize a phone structure.	160	/** Initialize a phone structure.
161	*	161	*
162	* @param phone Phone structure to be initialized.	162	* @param phone Phone structure to be initialized.
163	*/	163	*/
164	void ipc_phone_init(phone_t *phone)	164	void ipc_phone_init(phone_t *phone)
165	{	165	{
166	mutex_initialize(&phone->lock, MUTEX_PASSIVE);	166	mutex_initialize(&phone->lock, MUTEX_PASSIVE);
167	phone->callee = NULL;	167	phone->callee = NULL;
168	phone->state = IPC_PHONE_FREE;	168	phone->state = IPC_PHONE_FREE;
169	atomic_set(&phone->active_calls, 0);	169	atomic_set(&phone->active_calls, 0);
170	}	170	}
171		171
172	/** Helper function to facilitate synchronous calls.	172	/** Helper function to facilitate synchronous calls.
173	*	173	*
174	* @param phone Destination kernel phone structure.	174	* @param phone Destination kernel phone structure.
175	* @param request Call structure with request.	175	* @param request Call structure with request.
176	*	176	*
177	* @return EOK on success or EINTR if the sleep was interrupted.	177	* @return EOK on success or EINTR if the sleep was interrupted.
178	*/	178	*/
179	int ipc_call_sync(phone_t phone, call_t request)	179	int ipc_call_sync(phone_t phone, call_t request)
180	{	180	{
181	answerbox_t sync_box;	181	answerbox_t sync_box;
182		182
183	ipc_answerbox_init(&sync_box, TASK);	183	ipc_answerbox_init(&sync_box, TASK);
184		184
185	/* We will receive data in a special box. */	185	/* We will receive data in a special box. */
186	request->callerbox = &sync_box;	186	request->callerbox = &sync_box;
187		187
188	ipc_call(phone, request);	188	ipc_call(phone, request);
189	if (!ipc_wait_for_call(&sync_box, SYNCH_NO_TIMEOUT,	189	if (!ipc_wait_for_call(&sync_box, SYNCH_NO_TIMEOUT,
190	SYNCH_FLAGS_INTERRUPTIBLE))	190	SYNCH_FLAGS_INTERRUPTIBLE))
191	return EINTR;	191	return EINTR;
192	return EOK;	192	return EOK;
193	}	193	}
194		194
195	/** Answer a message which was not dispatched and is not listed in any queue.	195	/** Answer a message which was not dispatched and is not listed in any queue.
196	*	196	*
197	* @param call Call structure to be answered.	197	* @param call Call structure to be answered.
198	*/	198	*/
199	static void _ipc_answer_free_call(call_t *call)	199	static void _ipc_answer_free_call(call_t *call)
200	{	200	{
201	answerbox_t *callerbox = call->callerbox;	201	answerbox_t *callerbox = call->callerbox;
202		202
203	call->flags \|= IPC_CALL_ANSWERED;	203	call->flags \|= IPC_CALL_ANSWERED;
204		204
205	if (call->flags & IPC_CALL_FORWARDED) {	205	if (call->flags & IPC_CALL_FORWARDED) {
206	if (call->caller_phone) {	206	if (call->caller_phone) {
207	/* Demasquerade the caller phone. */	207	/* Demasquerade the caller phone. */
208	call->data.phone = call->caller_phone;	208	call->data.phone = call->caller_phone;
209	}	209	}
210	}	210	}
211		211
212	spinlock_lock(&callerbox->lock);	212	spinlock_lock(&callerbox->lock);
213	list_append(&call->link, &callerbox->answers);	213	list_append(&call->link, &callerbox->answers);
214	spinlock_unlock(&callerbox->lock);	214	spinlock_unlock(&callerbox->lock);
215	waitq_wakeup(&callerbox->wq, WAKEUP_FIRST);	215	waitq_wakeup(&callerbox->wq, WAKEUP_FIRST);
216	}	216	}
217		217
218	/** Answer a message which is in a callee queue.	218	/** Answer a message which is in a callee queue.
219	*	219	*
220	* @param box Answerbox that is answering the message.	220	* @param box Answerbox that is answering the message.
221	* @param call Modified request that is being sent back.	221	* @param call Modified request that is being sent back.
222	*/	222	*/
223	void ipc_answer(answerbox_t box, call_t call)	223	void ipc_answer(answerbox_t box, call_t call)
224	{	224	{
225	/* Remove from active box */	225	/* Remove from active box */
226	spinlock_lock(&box->lock);	226	spinlock_lock(&box->lock);
227	list_remove(&call->link);	227	list_remove(&call->link);
228	spinlock_unlock(&box->lock);	228	spinlock_unlock(&box->lock);
229	/* Send back answer */	229	/* Send back answer */
230	_ipc_answer_free_call(call);	230	_ipc_answer_free_call(call);
231	}	231	}
232		232
233	/** Simulate sending back a message.	233	/** Simulate sending back a message.
234	*	234	*
235	* Most errors are better handled by forming a normal backward	235	* Most errors are better handled by forming a normal backward
236	* message and sending it as a normal answer.	236	* message and sending it as a normal answer.
237	*	237	*
238	* @param phone Phone structure the call should appear to come from.	238	* @param phone Phone structure the call should appear to come from.
239	* @param call Call structure to be answered.	239	* @param call Call structure to be answered.
240	* @param err Return value to be used for the answer.	240	* @param err Return value to be used for the answer.
241	*/	241	*/
242	void ipc_backsend_err(phone_t phone, call_t call, unative_t err)	242	void ipc_backsend_err(phone_t phone, call_t call, unative_t err)
243	{	243	{
244	call->data.phone = phone;	244	call->data.phone = phone;
245	atomic_inc(&phone->active_calls);	245	atomic_inc(&phone->active_calls);
246	IPC_SET_RETVAL(call->data, err);	246	IPC_SET_RETVAL(call->data, err);
247	_ipc_answer_free_call(call);	247	_ipc_answer_free_call(call);
248	}	248	}
249		249
250	/** Unsafe unchecking version of ipc_call.	250	/** Unsafe unchecking version of ipc_call.
251	*	251	*
252	* @param phone Phone structure the call comes from.	252	* @param phone Phone structure the call comes from.
253	* @param box Destination answerbox structure.	253	* @param box Destination answerbox structure.
254	* @param call Call structure with request.	254	* @param call Call structure with request.
255	*/	255	*/
256	static void _ipc_call(phone_t phone, answerbox_t box, call_t *call)	256	static void _ipc_call(phone_t phone, answerbox_t box, call_t *call)
257	{	257	{
258	if (!(call->flags & IPC_CALL_FORWARDED)) {	258	if (!(call->flags & IPC_CALL_FORWARDED)) {
259	atomic_inc(&phone->active_calls);	259	atomic_inc(&phone->active_calls);
260	call->data.phone = phone;	260	call->data.phone = phone;
261	}	261	}
262		262
263	spinlock_lock(&box->lock);	263	spinlock_lock(&box->lock);
264	list_append(&call->link, &box->calls);	264	list_append(&call->link, &box->calls);
265	spinlock_unlock(&box->lock);	265	spinlock_unlock(&box->lock);
266	waitq_wakeup(&box->wq, WAKEUP_FIRST);	266	waitq_wakeup(&box->wq, WAKEUP_FIRST);
267	}	267	}
268		268
269	/** Send an asynchronous request using a phone to an answerbox.	269	/** Send an asynchronous request using a phone to an answerbox.
270	*	270	*
271	* @param phone Phone structure the call comes from and which is	271	* @param phone Phone structure the call comes from and which is
272	* connected to the destination answerbox.	272	* connected to the destination answerbox.
273	* @param call Call structure with request.	273	* @param call Call structure with request.
274	*	274	*
275	* @return Return 0 on success, ENOENT on error.	275	* @return Return 0 on success, ENOENT on error.
276	*/	276	*/
277	int ipc_call(phone_t phone, call_t call)	277	int ipc_call(phone_t phone, call_t call)
278	{	278	{
279	answerbox_t *box;	279	answerbox_t *box;
280		280
281	mutex_lock(&phone->lock);	281	mutex_lock(&phone->lock);
282	if (phone->state != IPC_PHONE_CONNECTED) {	282	if (phone->state != IPC_PHONE_CONNECTED) {
283	mutex_unlock(&phone->lock);	283	mutex_unlock(&phone->lock);
284	if (call->flags & IPC_CALL_FORWARDED) {	284	if (call->flags & IPC_CALL_FORWARDED) {
285	IPC_SET_RETVAL(call->data, EFORWARD);	285	IPC_SET_RETVAL(call->data, EFORWARD);
286	_ipc_answer_free_call(call);	286	_ipc_answer_free_call(call);
287	} else {	287	} else {
288	if (phone->state == IPC_PHONE_HUNGUP)	288	if (phone->state == IPC_PHONE_HUNGUP)
289	ipc_backsend_err(phone, call, EHANGUP);	289	ipc_backsend_err(phone, call, EHANGUP);
290	else	290	else
291	ipc_backsend_err(phone, call, ENOENT);	291	ipc_backsend_err(phone, call, ENOENT);
292	}	292	}
293	return ENOENT;	293	return ENOENT;
294	}	294	}
295	box = phone->callee;	295	box = phone->callee;
296	_ipc_call(phone, box, call);	296	_ipc_call(phone, box, call);
297		297
298	mutex_unlock(&phone->lock);	298	mutex_unlock(&phone->lock);
299	return 0;	299	return 0;
300	}	300	}
301		301
302	/** Disconnect phone from answerbox.	302	/** Disconnect phone from answerbox.
303	*	303	*
304	* This call leaves the phone in the HUNGUP state. The change to 'free' is done	304	* This call leaves the phone in the HUNGUP state. The change to 'free' is done
305	* lazily later.	305	* lazily later.
306	*	306	*
307	* @param phone Phone structure to be hung up.	307	* @param phone Phone structure to be hung up.
308	*	308	*
309	* @return Return 0 if the phone is disconnected.	309	* @return Return 0 if the phone is disconnected.
310	* Return -1 if the phone was already disconnected.	310	* Return -1 if the phone was already disconnected.
311	*/	311	*/
312	int ipc_phone_hangup(phone_t *phone)	312	int ipc_phone_hangup(phone_t *phone)
313	{	313	{
314	answerbox_t *box;	314	answerbox_t *box;
315	call_t *call;	315	call_t *call;
316		316
317	mutex_lock(&phone->lock);	317	mutex_lock(&phone->lock);
318	if (phone->state == IPC_PHONE_FREE \|\|	318	if (phone->state == IPC_PHONE_FREE \|\|
319	phone->state == IPC_PHONE_HUNGUP \|\|	319	phone->state == IPC_PHONE_HUNGUP \|\|
320	phone->state == IPC_PHONE_CONNECTING) {	320	phone->state == IPC_PHONE_CONNECTING) {
321	mutex_unlock(&phone->lock);	321	mutex_unlock(&phone->lock);
322	return -1;	322	return -1;
323	}	323	}
324	box = phone->callee;	324	box = phone->callee;
325	if (phone->state != IPC_PHONE_SLAMMED) {	325	if (phone->state != IPC_PHONE_SLAMMED) {
326	/* Remove myself from answerbox */	326	/* Remove myself from answerbox */
327	spinlock_lock(&box->lock);	327	spinlock_lock(&box->lock);
328	list_remove(&phone->link);	328	list_remove(&phone->link);
329	spinlock_unlock(&box->lock);	329	spinlock_unlock(&box->lock);
330		330
331	call = ipc_call_alloc(0);	331	call = ipc_call_alloc(0);
332	IPC_SET_METHOD(call->data, IPC_M_PHONE_HUNGUP);	332	IPC_SET_METHOD(call->data, IPC_M_PHONE_HUNGUP);
333	call->flags \|= IPC_CALL_DISCARD_ANSWER;	333	call->flags \|= IPC_CALL_DISCARD_ANSWER;
334	_ipc_call(phone, box, call);	334	_ipc_call(phone, box, call);
335	}	335	}
336		336
337	phone->state = IPC_PHONE_HUNGUP;	337	phone->state = IPC_PHONE_HUNGUP;
338	mutex_unlock(&phone->lock);	338	mutex_unlock(&phone->lock);
339		339
340	return 0;	340	return 0;
341	}	341	}
342		342
343	/** Forwards call from one answerbox to another one.	343	/** Forwards call from one answerbox to another one.
344	*	344	*
345	* @param call Call structure to be redirected.	345	* @param call Call structure to be redirected.
346	* @param newphone Phone structure to target answerbox.	346	* @param newphone Phone structure to target answerbox.
347	* @param oldbox Old answerbox structure.	347	* @param oldbox Old answerbox structure.
348	* @param mode Flags that specify mode of the forward operation.	348	* @param mode Flags that specify mode of the forward operation.
349	*	349	*
350	* @return Return 0 if forwarding succeeded or an error code if	350	* @return Return 0 if forwarding succeeded or an error code if
351	* there was error.	351	* there was error.
352	*	352	*
353	* The return value serves only as an information for the forwarder,	353	* The return value serves only as an information for the forwarder,
354	* the original caller is notified automatically with EFORWARD.	354	* the original caller is notified automatically with EFORWARD.
355	*/	355	*/
356	int ipc_forward(call_t call, phone_t newphone, answerbox_t *oldbox, int mode)	356	int ipc_forward(call_t call, phone_t newphone, answerbox_t *oldbox, int mode)
357	{	357	{
358	spinlock_lock(&oldbox->lock);	358	spinlock_lock(&oldbox->lock);
359	list_remove(&call->link);	359	list_remove(&call->link);
360	spinlock_unlock(&oldbox->lock);	360	spinlock_unlock(&oldbox->lock);
361		361
362	if (mode & IPC_FF_ROUTE_FROM_ME) {	362	if (mode & IPC_FF_ROUTE_FROM_ME) {
363	if (!call->caller_phone)	363	if (!call->caller_phone)
364	call->caller_phone = call->data.phone;	364	call->caller_phone = call->data.phone;
365	call->data.phone = newphone;	365	call->data.phone = newphone;
366	}	366	}
367		367
368	return ipc_call(newphone, call);	368	return ipc_call(newphone, call);
369	}	369	}
370		370
371		371
372	/** Wait for a phone call.	372	/** Wait for a phone call.
373	*	373	*
374	* @param box Answerbox expecting the call.	374	* @param box Answerbox expecting the call.
375	* @param usec Timeout in microseconds. See documentation for	375	* @param usec Timeout in microseconds. See documentation for
376	* waitq_sleep_timeout() for decription of its special	376	* waitq_sleep_timeout() for decription of its special
377	* meaning.	377	* meaning.
378	* @param flags Select mode of sleep operation. See documentation for	378	* @param flags Select mode of sleep operation. See documentation for
379	* waitq_sleep_timeout() for description of its special	379	* waitq_sleep_timeout() for description of its special
380	* meaning.	380	* meaning.
381	* @return Recived call structure or NULL.	381	* @return Recived call structure or NULL.
382	*	382	*
383	* To distinguish between a call and an answer, have a look at call->flags.	383	* To distinguish between a call and an answer, have a look at call->flags.
384	*/	384	*/
385	call_t ipc_wait_for_call(answerbox_t box, uint32_t usec, int flags)	385	call_t ipc_wait_for_call(answerbox_t box, uint32_t usec, int flags)
386	{	386	{
387	call_t *request;	387	call_t *request;
388	ipl_t ipl;	388	ipl_t ipl;
389	int rc;	389	int rc;
390		390
391	restart:	391	restart:
392	rc = waitq_sleep_timeout(&box->wq, usec, flags);	392	rc = waitq_sleep_timeout(&box->wq, usec, flags);
393	if (SYNCH_FAILED(rc))	393	if (SYNCH_FAILED(rc))
394	return NULL;	394	return NULL;
395		395
396	spinlock_lock(&box->lock);	396	spinlock_lock(&box->lock);
397	if (!list_empty(&box->irq_notifs)) {	397	if (!list_empty(&box->irq_notifs)) {
398	ipl = interrupts_disable();	398	ipl = interrupts_disable();
399	spinlock_lock(&box->irq_lock);	399	spinlock_lock(&box->irq_lock);
400		400
401	request = list_get_instance(box->irq_notifs.next, call_t, link);	401	request = list_get_instance(box->irq_notifs.next, call_t, link);
402	list_remove(&request->link);	402	list_remove(&request->link);
403		403
404	spinlock_unlock(&box->irq_lock);	404	spinlock_unlock(&box->irq_lock);
405	interrupts_restore(ipl);	405	interrupts_restore(ipl);
406	} else if (!list_empty(&box->answers)) {	406	} else if (!list_empty(&box->answers)) {
407	/* Handle asynchronous answers */	407	/* Handle asynchronous answers */
408	request = list_get_instance(box->answers.next, call_t, link);	408	request = list_get_instance(box->answers.next, call_t, link);
409	list_remove(&request->link);	409	list_remove(&request->link);
410	atomic_dec(&request->data.phone->active_calls);	410	atomic_dec(&request->data.phone->active_calls);
411	} else if (!list_empty(&box->calls)) {	411	} else if (!list_empty(&box->calls)) {
412	/* Handle requests */	412	/* Handle requests */
413	request = list_get_instance(box->calls.next, call_t, link);	413	request = list_get_instance(box->calls.next, call_t, link);
414	list_remove(&request->link);	414	list_remove(&request->link);
415	/* Append request to dispatch queue */	415	/* Append request to dispatch queue */
416	list_append(&request->link, &box->dispatched_calls);	416	list_append(&request->link, &box->dispatched_calls);
417	} else {	417	} else {
418	/* This can happen regularly after ipc_cleanup */	418	/* This can happen regularly after ipc_cleanup */
419	spinlock_unlock(&box->lock);	419	spinlock_unlock(&box->lock);
420	goto restart;	420	goto restart;
421	}	421	}
422	spinlock_unlock(&box->lock);	422	spinlock_unlock(&box->lock);
423	return request;	423	return request;
424	}	424	}
425		425
426	/** Answer all calls from list with EHANGUP answer.	426	/** Answer all calls from list with EHANGUP answer.
427	*	427	*
428	* @param lst Head of the list to be cleaned up.	428	* @param lst Head of the list to be cleaned up.
429	*/	429	*/
430	void ipc_cleanup_call_list(link_t *lst)	430	void ipc_cleanup_call_list(link_t *lst)
431	{	431	{
432	call_t *call;	432	call_t *call;
433		433
434	while (!list_empty(lst)) {	434	while (!list_empty(lst)) {
435	call = list_get_instance(lst->next, call_t, link);	435	call = list_get_instance(lst->next, call_t, link);
436	if (call->buffer)	436	if (call->buffer)
437	free(call->buffer);	437	free(call->buffer);
438	list_remove(&call->link);	438	list_remove(&call->link);
439		439
440	IPC_SET_RETVAL(call->data, EHANGUP);	440	IPC_SET_RETVAL(call->data, EHANGUP);
441	_ipc_answer_free_call(call);	441	_ipc_answer_free_call(call);
442	}	442	}
443	}	443	}
444		444
445	/** Disconnects all phones connected to an answerbox.	445	/** Disconnects all phones connected to an answerbox.
446	*	446	*
447	* @param box Answerbox to disconnect phones from.	447	* @param box Answerbox to disconnect phones from.
448	* @param notify_box If true, the answerbox will get a hangup message for	448	* @param notify_box If true, the answerbox will get a hangup message for
449	* each disconnected phone.	449	* each disconnected phone.
450	*/	450	*/
451	void ipc_answerbox_slam_phones(answerbox_t *box, bool notify_box)	451	void ipc_answerbox_slam_phones(answerbox_t *box, bool notify_box)
452	{	452	{
453	phone_t *phone;	453	phone_t *phone;
454	DEADLOCK_PROBE_INIT(p_phonelck);	454	DEADLOCK_PROBE_INIT(p_phonelck);
455	ipl_t ipl;	455	ipl_t ipl;
456	call_t *call;	456	call_t *call;
457		457
458	call = notify_box ? ipc_call_alloc(0) : NULL;	458	call = notify_box ? ipc_call_alloc(0) : NULL;
459		459
460	/* Disconnect all phones connected to our answerbox */	460	/* Disconnect all phones connected to our answerbox */
461	restart_phones:	461	restart_phones:
462	ipl = interrupts_disable();	462	ipl = interrupts_disable();
463	spinlock_lock(&box->lock);	463	spinlock_lock(&box->lock);
464	while (!list_empty(&box->connected_phones)) {	464	while (!list_empty(&box->connected_phones)) {
465	phone = list_get_instance(box->connected_phones.next,	465	phone = list_get_instance(box->connected_phones.next,
466	phone_t, link);	466	phone_t, link);
467	if (SYNCH_FAILED(mutex_trylock(&phone->lock))) {	467	if (SYNCH_FAILED(mutex_trylock(&phone->lock))) {
468	spinlock_unlock(&box->lock);	468	spinlock_unlock(&box->lock);
469	interrupts_restore(ipl);	469	interrupts_restore(ipl);
470	DEADLOCK_PROBE(p_phonelck, DEADLOCK_THRESHOLD);	470	DEADLOCK_PROBE(p_phonelck, DEADLOCK_THRESHOLD);
471	goto restart_phones;	471	goto restart_phones;
472	}	472	}
473		473
474	/* Disconnect phone */	474	/* Disconnect phone */
475	ASSERT(phone->state == IPC_PHONE_CONNECTED);	475	ASSERT(phone->state == IPC_PHONE_CONNECTED);
476		476
477	list_remove(&phone->link);	477	list_remove(&phone->link);
478	phone->state = IPC_PHONE_SLAMMED;	478	phone->state = IPC_PHONE_SLAMMED;
479		479
480	if (notify_box) {	480	if (notify_box) {
481	mutex_unlock(&phone->lock);	481	mutex_unlock(&phone->lock);
482	spinlock_unlock(&box->lock);	482	spinlock_unlock(&box->lock);
483	interrupts_restore(ipl);	483	interrupts_restore(ipl);
484		484
485	/*	485	/*
486	* Send one message to the answerbox for each	486	* Send one message to the answerbox for each
487	* phone. Used to make sure the kbox thread	487	* phone. Used to make sure the kbox thread
488	* wakes up after the last phone has been	488	* wakes up after the last phone has been
489	* disconnected.	489	* disconnected.
490	*/	490	*/
491	IPC_SET_METHOD(call->data, IPC_M_PHONE_HUNGUP);	491	IPC_SET_METHOD(call->data, IPC_M_PHONE_HUNGUP);
492	call->flags \|= IPC_CALL_DISCARD_ANSWER;	492	call->flags \|= IPC_CALL_DISCARD_ANSWER;
493	_ipc_call(phone, box, call);	493	_ipc_call(phone, box, call);
494		494
495	/* Allocate another call in advance */	495	/* Allocate another call in advance */
496	call = ipc_call_alloc(0);	496	call = ipc_call_alloc(0);
497		497
498	/* Must start again */	498	/* Must start again */
499	goto restart_phones;	499	goto restart_phones;
500	}	500	}

Subversion Repositories HelenOS

(root)/tags/0.4.1/kernel/generic/src/ipc/ipc.c – Rev 4405 → 4687