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/*

 * 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 <arch/asm.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>

/** 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)

{

    unsigned 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) || defined(ia64)

        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 <

            IPC_CALL_LEN) {

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

        }

    }

}

/** Free top-half pseudocode.

 *

 * @param code      Pointer to the top-half pseudocode.

 */

static void code_free(irq_code_t *code)

{

    if (code) {

        free(code->cmds);

        free(code);

    }

}

/** Copy top-half pseudocode from userspace into the kernel.

 *

 * @param ucode     Userspace address of the top-half pseudocode.

 *

 * @return      Kernel address of the copied pseudocode.

 */

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 number.

 * @param devno     Device number.

 */

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

{

    ipl_t ipl;

    irq_t *irq;

    ipl = interrupts_disable();

    irq = irq_find_and_lock(inr, devno);

    if (irq) {

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

            code_free(irq->notif_cfg.code);

            irq->notif_cfg.notify = false;

            irq->notif_cfg.answerbox = NULL;

            irq->notif_cfg.code = NULL;

            irq->notif_cfg.method = 0;

            irq->notif_cfg.counter = 0;

            spinlock_lock(&box->irq_lock);

            list_remove(&irq->notif_cfg.link);

            spinlock_unlock(&box->irq_lock);

            spinlock_unlock(&irq->lock);

        }

    }

    interrupts_restore(ipl);

}

/** 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;

    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 (irq->notif_cfg.answerbox) {

        spinlock_unlock(&irq->lock);

        interrupts_restore(ipl);

        code_free(code);

        return EEXISTS;

    }

    irq->notif_cfg.notify = true;

    irq->notif_cfg.answerbox = box;

    irq->notif_cfg.method = method;

    irq->notif_cfg.code = code;

    irq->notif_cfg.counter = 0;

    spinlock_lock(&box->irq_lock);

    list_append(&irq->notif_cfg.link, &box->irq_head);

    spinlock_unlock(&box->irq_lock);

    spinlock_unlock(&irq->lock);

    interrupts_restore(ipl);

    return 0;

}

/** Add a call to the proper answerbox queue.

 *

 * Assume irq->lock is locked.

 *

 * @param irq       IRQ structure referencing the target answerbox.

 * @param call      IRQ notification call.

 */

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

{

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

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

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

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

}

/** Send notification message.

 *

 * @param irq       IRQ structure.

 * @param a1        Driver-specific payload argument.

 * @param a2        Driver-specific payload argument.

 * @param a3        Driver-specific payload argument.

 * @param a4        Driver-specific payload argument.

 * @param a5        Driver-specific payload argument.

 */

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

    unative_t a4, unative_t a5)

{

    call_t *call;

    spinlock_lock(&irq->lock);

    if (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, irq->notif_cfg.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);

        /* Put a counter to the message */

        call->priv = ++irq->notif_cfg.counter;

        send_call(irq, call);

    }

    spinlock_unlock(&irq->lock);

}

/** Notify a task that an IRQ had occurred.

 *

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

 *

 * @param irq       IRQ structure.

 */

void ipc_irq_send_notif(irq_t *irq)

{

    call_t *call;

    ASSERT(irq);

    if (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 = ++irq->notif_cfg.counter;

        /* Set up args */

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

        /* Execute code to handle irq */

        code_execute(call, 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;

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(&irq->notif_cfg.link);

        /*

         * Don't forget to free any top-half pseudocode.

         */

        code_free(irq->notif_cfg.code);

        irq->notif_cfg.notify = false;

        irq->notif_cfg.answerbox = NULL;

        irq->notif_cfg.code = NULL;

        irq->notif_cfg.method = 0;

        irq->notif_cfg.counter = 0;

        spinlock_unlock(&irq->lock);

    }

    spinlock_unlock(&box->irq_lock);

    interrupts_restore(ipl);

}

/** @}

 */