Subversion Repositories HelenOS

/*

 * Copyright (c) 2006 Ondrej Palkovsky

 * Copyright (c) 2006 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 genericipc

 * @{

 */

/**

 * @file

 * @brief IRQ notification framework.

 *

 * This framework allows applications to register to receive a notification

 * when interrupt is detected. The application may provide a simple 'top-half'

 * handler as part of its registration, which can perform simple operations

 * (read/write port/memory, add information to notification ipc message).

 *

 * The structure of a notification message is as follows:

 * - METHOD: method as registered by the SYS_IPC_REGISTER_IRQ syscall

 * - ARG1: payload modified by a 'top-half' handler

 * - ARG2: payload modified by a 'top-half' handler

 * - ARG3: payload modified by a 'top-half' handler

 * - in_phone_hash: interrupt counter (may be needed to assure correct order

 *         in multithreaded drivers)

 */

#include <arch.h>

#include <mm/slab.h>

#include <errno.h>

#include <ddi/irq.h>

#include <ipc/ipc.h>

#include <ipc/irq.h>

#include <syscall/copy.h>

#include <console/console.h>

#include <print.h>

#include <synch/rcu.h>

#include <adt/listrcu.h>

/** Execute code associated with IRQ notification.

 *

 * @param call Notification call.

 * @param code Top-half pseudocode.

 */

static void code_execute(call_t *call, irq_code_t *code)

{

    int i;

    unative_t dstval = 0;

    if (!code)

        return;

    for (i=0; i < code->cmdcount;i++) {

        switch (code->cmds[i].cmd) {

        case CMD_MEM_READ_1:

            dstval = *((uint8_t *)code->cmds[i].addr);

            break;

        case CMD_MEM_READ_2:

            dstval = *((uint16_t *)code->cmds[i].addr);

            break;

        case CMD_MEM_READ_4:

            dstval = *((uint32_t *)code->cmds[i].addr);

            break;

        case CMD_MEM_READ_8:

            dstval = *((uint64_t *)code->cmds[i].addr);

            break;

        case CMD_MEM_WRITE_1:

            *((uint8_t *)code->cmds[i].addr) = code->cmds[i].value;

            break;

        case CMD_MEM_WRITE_2:

            *((uint16_t *)code->cmds[i].addr) = code->cmds[i].value;

            break;

        case CMD_MEM_WRITE_4:

            *((uint32_t *)code->cmds[i].addr) = code->cmds[i].value;

            break;

        case CMD_MEM_WRITE_8:

            *((uint64_t *)code->cmds[i].addr) = code->cmds[i].value;

            break;

#if defined(ia32) || defined(amd64)

        case CMD_PORT_READ_1:

            dstval = inb((long)code->cmds[i].addr);

            break;

        case CMD_PORT_WRITE_1:

            outb((long)code->cmds[i].addr, code->cmds[i].value);

            break;

#endif

#if defined(ia64) && defined(SKI)

        case CMD_IA64_GETCHAR:

            dstval = _getc(&ski_uconsole);

            break;

#endif

#if defined(ppc32)

        case CMD_PPC32_GETCHAR:

            dstval = cuda_get_scancode();

            break;

#endif

        default:

            break;

        }

        if (code->cmds[i].dstarg && code->cmds[i].dstarg < 4) {

            call->data.args[code->cmds[i].dstarg] = dstval;

        }

    }

}

static void code_free(irq_code_t *code)

{

    if (code) {

        free(code->cmds);

        free(code);

    }

}

static irq_code_t * code_from_uspace(irq_code_t *ucode)

{

    irq_code_t *code;

    irq_cmd_t *ucmds;

    int rc;

    code = malloc(sizeof(*code), 0);

    rc = copy_from_uspace(code, ucode, sizeof(*code));

    if (rc != 0) {

        free(code);

        return NULL;

    }

    if (code->cmdcount > IRQ_MAX_PROG_SIZE) {

        free(code);

        return NULL;

    }

    ucmds = code->cmds;

    code->cmds = malloc(sizeof(code->cmds[0]) * (code->cmdcount), 0);

    rc = copy_from_uspace(code->cmds, ucmds, sizeof(code->cmds[0]) * (code->cmdcount));

    if (rc != 0) {

        free(code->cmds);

        free(code);

        return NULL;

    }

    return code;

}

/** Unregister task from IRQ notification.

 *

 * @param box Answerbox associated with the notification.

 * @param inr IRQ numbe.

 * @param devno Device number.

 */

void ipc_irq_unregister(answerbox_t *box, inr_t inr, devno_t devno)

{

    ipl_t ipl;

    irq_t *irq;

    ipc_notif_cfg_t *new_notify, *old_notify;

    ipl = interrupts_disable();

    irq = irq_find_and_lock(inr, devno);

    if (irq) {

        if (rcu_dereference_pointer(irq->notif_cfg).answerbox == box) {

            new_notify = malloc(sizeof(ipc_notif_cfg_t),0);

            new_notify->notify = false;

            new_notify->answerbox = NULL;

            new_notify->code = NULL;

            new_notify->method = 0;

            new_notify->counter = 0;

            old_notify = irq->notif_cfg;

            copy_link_rcu(&irq->notif_cfg->link, &new_notify->link);

            rcu_assign_pointer(old_notify, new_notify);

            spinlock_lock(&box->irq_lock);

            list_remove_rcu(&rcu_dereference_pointer(irq->notif_cfg).link);

            spinlock_unlock(&box->irq_lock);

            rcu_sync_callback_normal_alloc(&ipc_notif_free_callback, irq->notif_cfg);

            spinlock_unlock(&irq->lock);

        }

    }

    interrupts_restore(ipl);

}

void ipc_notif_free_callback(void* notif)

{

    code_free(((ipc_notif_cfg_t *)notif)->code);

    free(notif);

}

/** Register an answerbox as a receiving end for IRQ notifications.

 *

 * @param box Receiving answerbox.

 * @param inr IRQ number.

 * @param devno Device number.

 * @param method Method to be associated with the notification.

 * @param ucode Uspace pointer to top-half pseudocode.

 *

 * @return EBADMEM, ENOENT or EEXISTS on failure or 0 on success.

 */

int ipc_irq_register(answerbox_t *box, inr_t inr, devno_t devno, unative_t method, irq_code_t *ucode)

{

    ipl_t ipl;

    irq_code_t *code;

    irq_t *irq;

    ipc_notif_cfg_t *new_notify, *old_notify;

    if (ucode) {

        code = code_from_uspace(ucode);

        if (!code)

            return EBADMEM;

    } else

        code = NULL;

    ipl = interrupts_disable();

    irq = irq_find_and_lock(inr, devno);

    if (!irq) {

        interrupts_restore(ipl);

        code_free(code);

        return ENOENT;

    }

    if (rcu_dereference_pointer(irq->notif_cfg).answerbox) {

        spinlock_unlock(&irq->lock);

        interrupts_restore(ipl);

        code_free(code);

        return EEXISTS;

    }

    new_notify = malloc(sizeof(ipc_notif_cfg_t),0);

    new_notify->notify = true;

    new_notify->answerbox = box;

    new_notify->method = method;

    new_notify->code = code;

    new_notify->counter = 0;

    copy_link_rcu(&irq->notif_cfg->link, &new_notify->link);

    old_notify = irq->notif_cfg;

    rcu_assign_pointer(irq->notif_cfg, new_notify);

    rcu_sync_callback_normal_alloc(&ipc_notif_free_callback, old_notify);

    spinlock_lock(&box->irq_lock);

    list_append_rcu(&new_notify->link, &box->irq_head);

    spinlock_unlock(&box->irq_lock);

    spinlock_unlock(&irq->lock);

    interrupts_restore(ipl);

    return 0;

}

/** Add call to proper answerbox queue.

 *

 * Assume irq->lock is locked.

 *

 */

static void send_call(irq_t *irq, call_t *call)

{

    spinlock_lock(&rcu_dereference_pointer(irq->notif_cfg).answerbox->irq_lock);

    list_append_rcu(&call->link, &rcu_dereference_pointer(irq->notif_cfg).answerbox->irq_notifs);

    spinlock_unlock(&rcu_dereference_pointer(irq->notif_cfg).answerbox->irq_lock);

    waitq_wakeup(&rcu_dereference_pointer(irq->notif_cfg).answerbox->wq, WAKEUP_FIRST);

}

/** Send notification message

 *

 */

void ipc_irq_send_msg(irq_t *irq, unative_t a1, unative_t a2, unative_t a3)

{

    call_t *call;

    spinlock_lock(&irq->lock);

    if (rcu_dereference_pointer(irq->notif_cfg).answerbox) {

        call = ipc_call_alloc(FRAME_ATOMIC);

        if (!call) {

            spinlock_unlock(&irq->lock);

            return;

        }

        call->flags |= IPC_CALL_NOTIF;

        IPC_SET_METHOD(call->data, rcu_dereference_pointer(irq->notif_cfg).method);

        IPC_SET_ARG1(call->data, a1);

        IPC_SET_ARG2(call->data, a2);

        IPC_SET_ARG3(call->data, a3);

        /* Put a counter to the message */

        call->priv = ++rcu_dereference_pointer(irq->notif_cfg).counter;

        send_call(irq, call);

    }

    spinlock_unlock(&irq->lock);

}

/** Notify task that an irq had occurred.

 *

 * We expect interrupts to be disabled and the irq->lock already held.

 */

void ipc_irq_send_notif(irq_t *irq)

{

    call_t *call;

    ASSERT(irq);

    if (rcu_dereference_pointer(irq->notif_cfg).answerbox) {

        call = ipc_call_alloc(FRAME_ATOMIC);

        if (!call) {

            return;

        }

        call->flags |= IPC_CALL_NOTIF;

        /* Put a counter to the message */

        call->priv = ++rcu_dereference_pointer(irq->notif_cfg).counter;

        /* Set up args */

        IPC_SET_METHOD(call->data, rcu_dereference_pointer(irq->notif_cfg).method);

        /* Execute code to handle irq */

        code_execute(call, rcu_dereference_pointer(irq->notif_cfg).code);

        send_call(irq, call);

    }

}

/** Disconnect all IRQ notifications from an answerbox.

 *

 * This function is effective because the answerbox contains

 * list of all irq_t structures that are registered to

 * send notifications to it.

 *

 * @param box Answerbox for which we want to carry out the cleanup.

 */

void ipc_irq_cleanup(answerbox_t *box)

{

    ipl_t ipl;

    ipc_notif_cfg_t *new_notify, *old_notify;

loop:

    ipl = interrupts_disable();

    spinlock_lock(&box->irq_lock);

    while (box->irq_head.next != &box->irq_head) {

        link_t *cur = box->irq_head.next;

        irq_t *irq;

        DEADLOCK_PROBE_INIT(p_irqlock);

        irq = list_get_instance(cur, irq_t, notif_cfg->link);

        if (!spinlock_trylock(&irq->lock)) {

            /*

             * Avoid deadlock by trying again.

             */

            spinlock_unlock(&box->irq_lock);

            interrupts_restore(ipl);

            DEADLOCK_PROBE(p_irqlock, DEADLOCK_THRESHOLD);

            goto loop;

        }

        ASSERT(irq->notif_cfg->answerbox == box);

        list_remove_rcu(&irq->notif_cfg->link);

        new_notify = malloc(sizeof(ipc_notif_cfg_t),0);

        new_notify->notify = false;

        new_notify->answerbox = NULL;

        new_notify->method = 0;

        new_notify->code = NULL;

        new_notify->counter = 0;

        copy_link_rcu(&irq->notif_cfg->link, &new_notify->link);

        old_notify = irq->notif_cfg;

        rcu_assign_pointer(irq->notif_cfg, new_notify);

        rcu_sync_callback_normal_alloc(&ipc_notif_free_callback, old_notify);

        spinlock_unlock(&irq->lock);

    }

    spinlock_unlock(&box->irq_lock);

    interrupts_restore(ipl);

}

/** @}

 */