/*
 * (MPSAFE)
 *
 * Copyright (c) 2006 The DragonFly Project.  All rights reserved.
 *
 * This code is derived from software contributed to The DragonFly Project
 * by Matthew Dillon <dillon@backplane.com>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. Neither the name of The DragonFly Project nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific, prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``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
 * COPYRIGHT HOLDERS OR CONTRIBUTORS 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.
 *
 */

#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/conf.h>
#include <sys/cons.h>
#include <sys/tty.h>
#include <sys/fcntl.h>
#include <sys/signalvar.h>
#include <sys/eventhandler.h>
#include <sys/interrupt.h>
#include <sys/bus.h>
#include <machine/md_var.h>
#include <unistd.h>
#include <termios.h>
#include <stdlib.h>

static int console_stolen_by_kernel;
static struct kqueue_info *kqueue_console_info;
static struct tty *kqueue_console_tty;
static int vcons_started;

/************************************************************************
 *                          CONSOLE DEVICE                              *
 ************************************************************************
 *
 */

static int vcons_tty_param(struct tty *tp, struct termios *tio);
static void vcons_tty_start(struct tty *tp);
static void vcons_hardintr(void *tpx, struct intrframe *frame __unused);

static d_open_t         vcons_open;
static d_close_t        vcons_close;
static d_ioctl_t        vcons_ioctl;

static struct dev_ops vcons_ops = {
        { "vcons", 0, D_TTY },
        .d_open =       vcons_open,
        .d_close =      vcons_close,
        .d_read =       ttyread,
        .d_write =      ttywrite,
        .d_ioctl =      vcons_ioctl,
        .d_kqfilter =   ttykqfilter
};

static int
vcons_open(struct dev_open_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        struct tty *tp;
        int error;

        tp = ttymalloc(&dev->si_tty);
        lwkt_gettoken(&tp->t_token);

#define ISSET(t, f)     ((t) & (f))

        if ((tp->t_state & TS_ISOPEN) == 0) {
                tp->t_oproc = vcons_tty_start;
                tp->t_param = vcons_tty_param;
                tp->t_stop = nottystop;
                tp->t_dev = dev;

                tp->t_state |= TS_CARR_ON | TS_CONNECTED;
                ttychars(tp);
                tp->t_iflag = TTYDEF_IFLAG;
                tp->t_oflag = TTYDEF_OFLAG;
                tp->t_cflag = TTYDEF_CFLAG;
                tp->t_lflag = TTYDEF_LFLAG;
                tp->t_ispeed = TTYDEF_SPEED;
                tp->t_ospeed = TTYDEF_SPEED;
                ttsetwater(tp);
        }
        if (minor(dev) == 0) {
                error = (*linesw[tp->t_line].l_open)(dev, tp);
                ioctl(0, TIOCGWINSZ, &tp->t_winsize);

                if (kqueue_console_info == NULL) {
                        kqueue_console_tty = tp;
                        kqueue_console_info = kqueue_add(0, vcons_hardintr, tp);
                }
        } else {
                /* dummy up other minors so the installer will run */
                error = 0;
        }
        lwkt_reltoken(&tp->t_token);

        return(error);
}

static int
vcons_close(struct dev_close_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        struct tty *tp;

        tp = dev->si_tty;
        lwkt_gettoken(&tp->t_token);
        (*linesw[tp->t_line].l_close)(tp, ap->a_fflag);
        ttyclose(tp);
        lwkt_reltoken(&tp->t_token);
        return(0);
}

static int
vcons_ioctl(struct dev_ioctl_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        struct tty *tp;
        int error;

        tp = dev->si_tty;
        lwkt_gettoken(&tp->t_token);
        error = (*linesw[tp->t_line].l_ioctl)(tp, ap->a_cmd, ap->a_data,
                                              ap->a_fflag, ap->a_cred);
        if (error != ENOIOCTL) {
                lwkt_reltoken(&tp->t_token);
                return (error);
        }
        error = ttioctl(tp, ap->a_cmd, ap->a_data, ap->a_fflag);
        if (error != ENOIOCTL) {
                lwkt_reltoken(&tp->t_token);
                return (error);
        }
        lwkt_reltoken(&tp->t_token);

        return (ENOTTY);
}

static int
vcons_tty_param(struct tty *tp, struct termios *tio)
{
        lwkt_gettoken(&tp->t_token);
        tp->t_ispeed = tio->c_ispeed;
        tp->t_ospeed = tio->c_ospeed;
        tp->t_cflag = tio->c_cflag;
        lwkt_reltoken(&tp->t_token);
        return(0);
}

static void
vcons_tty_start(struct tty *tp)
{
        int n;
        char buf[64];

        lwkt_gettoken(&tp->t_token);
        if (tp->t_state & (TS_TIMEOUT | TS_TTSTOP)) {
                ttwwakeup(tp);
                lwkt_reltoken(&tp->t_token);
                return;
        }
        tp->t_state |= TS_BUSY;
        while ((n = clist_qtob(&tp->t_outq, buf, sizeof(buf))) > 0) {
                /*
                 * Dummy up ttyv1, etc.
                 */
                if (minor(tp->t_dev) == 0) {
                        pwrite(1, buf, n, -1);
                }
        }
        tp->t_state &= ~TS_BUSY;
        lwkt_reltoken(&tp->t_token);
        ttwwakeup(tp);
}

static
void
vcons_hardintr(void *tpx, struct intrframe *frame __unused)
{
        if (console_stolen_by_kernel == 0)
                signalintr(4);
}

/************************************************************************
 *                      KERNEL CONSOLE INTERFACE                        *
 ************************************************************************
 *
 * Kernel direct-call interface console driver
 */
static cn_probe_t       vconsprobe;
static cn_init_t        vconsinit;
static cn_init_fini_t   vconsinit_fini;
static cn_term_t        vconsterm;
static cn_getc_t        vconsgetc;
static cn_checkc_t      vconscheckc;
static cn_putc_t        vconsputc;

CONS_DRIVER(vcons, vconsprobe, vconsinit, vconsinit_fini, vconsterm, vconsgetc,
                vconscheckc, vconsputc, NULL, NULL);

static struct termios init_tio;
static struct consdev *vconsole;

static void
vconsprobe(struct consdev *cp)
{
        cp->cn_pri = CN_NORMAL;
        cp->cn_probegood = 1;
}

/*
 * This is a little bulky handler to set proper terminal
 * settings in the case of a signal which might lead to
 * termination or suspension.
 */
static void
vconssignal(int sig)
{
        struct termios curtio;
        struct sigaction sa, osa;
        sigset_t ss, oss;

        tcgetattr(0, &curtio);
        tcsetattr(0, TCSAFLUSH, &init_tio);
        bzero(&sa, sizeof(sa));
        sigemptyset(&sa.sa_mask);
        sa.sa_handler = SIG_DFL;
        sigaction(sig, &sa, &osa);
        sigemptyset(&ss);
        sigaddset(&ss, sig);
        sigprocmask(SIG_UNBLOCK, &ss, &oss);
        raise(sig);     /* now hand down the sig */
        sigprocmask(SIG_SETMASK, &oss, NULL);
        sigaction(sig, &osa, NULL);
        tcsetattr(0, TCSAFLUSH, &curtio);
}

static void
vconswinchsig(int __unused sig)
{
        signalintr(3);
}

static void
vconswinch_intr(void *arg __unused, void *frame __unused)
{
        struct winsize newsize;

        if (vconsole != NULL && vconsole->cn_dev->si_tty != NULL) {
                ioctl(0, TIOCGWINSZ, &newsize);
                /*
                 * ttioctl(vconsole->cn_dev->si_tty, TIOCSWINSZ, &newsize, 0);
                 * I wished.  Unfortunately this needs a curproc, so do it
                 * manually.
                 */
                if (bcmp(&newsize, &vconsole->cn_dev->si_tty->t_winsize,
                         sizeof(newsize)) != 0) {
                        vconsole->cn_dev->si_tty->t_winsize = newsize;
                        pgsignal(vconsole->cn_dev->si_tty->t_pgrp, SIGWINCH, 1);
                }
        }
}

/*
 * This has to be an interrupt thread and not a hard interrupt.
 */
static
void
vconsvirt_intr(void *arg __unused, void *frame __unused)
{
        struct tty *tp;
        unsigned char buf[32];
        int i;
        int n;

        if (kqueue_console_info == NULL)
                return;
        tp = kqueue_console_tty;

        lwkt_gettoken(&tp->t_token);
        /*
         * If we aren't open we only have synchronous traffic via the
         * debugger and do not need to poll.
         */
        if ((tp->t_state & TS_ISOPEN) == 0) {
                lwkt_reltoken(&tp->t_token);
                return;
        }

        /*
         * Only poll if we are open and haven't been stolen by the debugger.
         */
        if (console_stolen_by_kernel == 0 && (tp->t_state & TS_ISOPEN)) {
                do {
                        n = extpread(0, buf, sizeof(buf), O_FNONBLOCKING, -1LL);
                        for (i = 0; i < n; ++i)
                                (*linesw[tp->t_line].l_rint)(buf[i], tp);
                } while (n > 0);
        }
        lwkt_reltoken(&tp->t_token);
}



static void
vconscleanup(void)
{
        /*
         * We might catch stray SIGIOs, so try hard.
         */
        while (tcsetattr(0, TCSAFLUSH, &init_tio) != 0 && errno == EINTR)
                /* NOTHING */;
}

static void
vconsinit(struct consdev *cp)
{
        struct sigaction sa;

        if (vcons_started)
                return;
        vcons_started = 1;
        vconsole = cp;

        tcgetattr(0, &init_tio);
        bzero(&sa, sizeof(sa));
        sigemptyset(&sa.sa_mask);
        sa.sa_handler = vconssignal;
        sigaction(SIGTSTP, &sa, NULL);
        sigaction(SIGINT, &sa, NULL);
        sigaction(SIGTERM, &sa, NULL);
        atexit(vconscleanup);
        vcons_set_mode(0);
}

static void
vconsinit_fini(struct consdev *cp)
{
        struct sigaction sa;
        cdev_t dev;
        int i;

        /*
         * We have to do this here rather then in early boot to be able
         * to use the interrupt subsystem.
         */
        register_int_virtual(3, vconswinch_intr, NULL, "swinch", NULL,
                             INTR_MPSAFE);
        register_int_virtual(4, vconsvirt_intr, NULL, "vintr", NULL,
                             INTR_MPSAFE);
        bzero(&sa, sizeof(sa));
        sigemptyset(&sa.sa_mask);
        sa.sa_handler = vconswinchsig;
        sigaction(SIGWINCH, &sa, NULL);

        /*
         * Implement ttyv0-ttyv7.  At the moment ttyv1-7 are sink nulls.
         */
        for (i = 0; i < 8; ++i) {
                dev = make_dev(&vcons_ops, i,
                               UID_ROOT, GID_WHEEL, 0600, "ttyv%d", i);
                if (i == 0) {
                        cp->cn_dev = dev;
                }
        }
        EVENTHANDLER_REGISTER(shutdown_final, vconscleanup, NULL, SHUTDOWN_PRI_LAST);
}

static void
vconsterm(struct consdev *vp)
{
        vconsole = NULL;
        vconscleanup();
}

static int
vconsgetc(void *private)
{
        unsigned char c;
        ssize_t n;

        console_stolen_by_kernel = 1;
        for (;;) {
                n = pread(0, &c, 1, -1);
                if (n == 1)
                        break;
                if (n < 0 && errno == EINTR)
                        continue;
                panic("vconsgetc: EOF on console %jd %d", (intmax_t)n, errno);
        }
        console_stolen_by_kernel = 0;
        return((int)c);
}

static int
vconscheckc(void *private)
{
        unsigned char c;

        if (extpread(0, &c, 1, O_FNONBLOCKING, -1LL) == 1)
                return((int)c);
        return(-1);
}

static void
vconsputc(void *private, int c)
{
        char cc = c;

        pwrite(1, &cc, 1, -1);
}

void
vcons_set_mode(int in_debugger)
{
        struct termios tio;

        if (tcgetattr(0, &tio) < 0) {
                return;
        }
        cfmakeraw(&tio);
        tio.c_oflag |= OPOST | ONLCR;
        tio.c_lflag |= ISIG;
        if (in_debugger) {
                tio.c_cc[VINTR] = init_tio.c_cc[VINTR];
                tio.c_cc[VSUSP] = init_tio.c_cc[VSUSP];
                tio.c_cc[VSTATUS] = init_tio.c_cc[VSTATUS];
        } else {
                tio.c_cc[VINTR] = _POSIX_VDISABLE;
                tio.c_cc[VSUSP] = _POSIX_VDISABLE;
                tio.c_cc[VSTATUS] = _POSIX_VDISABLE;
        }
        tcsetattr(0, TCSAFLUSH, &tio);
}