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/*

 * 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.

 */

/** 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: IPC_M_INTERRUPT

 * - ARG1: interrupt number

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

 * - ARG3: interrupt counter (may be needed to assure correct order

 *         in multithreaded drivers)

 */

#include <arch.h>

#include <mm/slab.h>

#include <errno.h>

#include <ipc/ipc.h>

#include <ipc/irq.h>

#include <atomic.h>

#include <syscall/copy.h>

typedef struct {

    SPINLOCK_DECLARE(lock);

    answerbox_t *box;

    irq_code_t *code;

    atomic_t counter;

} ipc_irq_t;

static ipc_irq_t *irq_conns = NULL;

static int irq_conns_size;

#include <print.h>

/* Execute code associated with IRQ notification */

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

{

    int i;

    if (!code)

        return;

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

        switch (code->cmds[i].cmd) {

        case CMD_MEM_READ_1:

            IPC_SET_ARG2(call->data, *((__u8 *)code->cmds[i].addr));

            break;

        case CMD_MEM_READ_2:

            IPC_SET_ARG2(call->data, *((__u16 *)code->cmds[i].addr));

            break;

        case CMD_MEM_READ_4:

            IPC_SET_ARG2(call->data, *((__u32 *)code->cmds[i].addr));

            break;

        case CMD_MEM_READ_8:

            IPC_SET_ARG2(call->data, *((__u64 *)code->cmds[i].addr));

            break;

        case CMD_MEM_WRITE_1:

            *((__u8 *)code->cmds[i].addr) = code->cmds[i].value;

            break;

        case CMD_MEM_WRITE_2:

            *((__u16 *)code->cmds[i].addr) = code->cmds[i].value;

            break;

        case CMD_MEM_WRITE_4:

            *((__u32 *)code->cmds[i].addr) = code->cmds[i].value;

            break;

        case CMD_MEM_WRITE_8:

            *((__u64 *)code->cmds[i].addr) = code->cmds[i].value;

            break;

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

        case CMD_PORT_READ_1:

            IPC_SET_ARG2(call->data, inb((long)code->cmds[i].addr));

            break;

        case CMD_PORT_WRITE_1:

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

            break;

#endif

        default:

            break;

        }

    }

}

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 */

void ipc_irq_unregister(answerbox_t *box, int irq)

{

    ipl_t ipl;

    ipl = interrupts_disable();

    spinlock_lock(&irq_conns[irq].lock);

    if (irq_conns[irq].box == box) {

        irq_conns[irq].box = NULL;

        code_free(irq_conns[irq].code);

        irq_conns[irq].code = NULL;

    }

    spinlock_unlock(&irq_conns[irq].lock);

    interrupts_restore(ipl);

}

/** Register an answerbox as a receiving end of interrupts notifications */

int ipc_irq_register(answerbox_t *box, int irq, irq_code_t *ucode)

{

    ipl_t ipl;

    irq_code_t *code;

    ASSERT(irq_conns);

    if (ucode) {

        code = code_from_uspace(ucode);

        if (!code)

            return EBADMEM;

    } else

        code = NULL;

    ipl = interrupts_disable();

    spinlock_lock(&irq_conns[irq].lock);

    if (irq_conns[irq].box) {

        spinlock_unlock(&irq_conns[irq].lock);

        interrupts_restore(ipl);

        code_free(code);

        return EEXISTS;

    }

    irq_conns[irq].box = box;

    irq_conns[irq].code = code;

    atomic_set(&irq_conns[irq].counter, 0);

    spinlock_unlock(&irq_conns[irq].lock);

    interrupts_restore(ipl);

    return 0;

}

/** Notify process that an irq had happend

 *

 * We expect interrupts to be disabled

 */

void ipc_irq_send_notif(int irq)

{

    call_t *call;

    ASSERT(irq_conns);

    spinlock_lock(&irq_conns[irq].lock);

    if (irq_conns[irq].box) {

        call = ipc_call_alloc(FRAME_ATOMIC);

        call->flags |= IPC_CALL_NOTIF;

        IPC_SET_METHOD(call->data, IPC_M_INTERRUPT);

        IPC_SET_ARG1(call->data, irq);

        IPC_SET_ARG3(call->data, atomic_preinc(&irq_conns[irq].counter));

        /* Execute code to handle irq */

        code_execute(call, irq_conns[irq].code);

        spinlock_lock(&irq_conns[irq].box->irq_lock);

        list_append(&call->list, &irq_conns[irq].box->irq_notifs);

        spinlock_unlock(&irq_conns[irq].box->irq_lock);

        waitq_wakeup(&irq_conns[irq].box->wq, 0);

    }

    spinlock_unlock(&irq_conns[irq].lock);

}

/** Initialize table of interrupt handlers */

void ipc_irq_make_table(int irqcount)

{

    int i;

    irq_conns_size = irqcount;

    irq_conns = malloc(irqcount * (sizeof(*irq_conns)), 0);

    for (i=0; i < irqcount; i++) {

        spinlock_initialize(&irq_conns[i].lock, "irq_ipc_lock");

        irq_conns[i].box = NULL;

        irq_conns[i].code = NULL;

    }

}

/** Disconnect all irq's notifications

 *

 * TODO: It may be better to do some linked list, so that

 *       we wouldn't need to go through whole array every cleanup

 */

void ipc_irq_cleanup(answerbox_t *box)

{

    int i;

    ipl_t ipl;

    for (i=0; i < irq_conns_size; i++) {

        ipl = interrupts_disable();

        spinlock_lock(&irq_conns[i].lock);

        if (irq_conns[i].box == box)

            irq_conns[i].box = NULL;

        spinlock_unlock(&irq_conns[i].lock);

        interrupts_restore(ipl);

    }

}