/*-
 * SPDX-License-Identifier: BSD-4-Clause
 *
 * Copyright (c) 2002-2003
 *      Hidetoshi Shimokawa. All rights reserved.
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *
 *      This product includes software developed by Hidetoshi Shimokawa.
 *
 * 4. Neither the name of the author 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 REGENTS 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 REGENTS 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.
 */

#ifdef HAVE_KERNEL_OPTION_HEADERS
#include "opt_device_polling.h"
#include "opt_inet.h"
#endif

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <machine/bus.h>

#include <net/bpf.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_arp.h>
#include <net/if_types.h>
#include <net/if_vlan_var.h>

#include <dev/firewire/firewire.h>
#include <dev/firewire/firewirereg.h>
#include <dev/firewire/if_fwevar.h>
#include <dev/firewire/fw_net.h>

#define FWEDEBUG        if (fwedebug) if_printf
#define TX_MAX_QUEUE    (FWMAXQUEUE - 1)

/* network interface */
static void fwe_start (if_t);
static int fwe_ioctl (if_t, u_long, caddr_t);
static void fwe_init (void *);

static void fwe_output_callback (struct fw_xfer *);
static void fwe_as_output (struct fwe_softc *, if_t);
static void fwe_as_input (struct fw_xferq *);

static int fwedebug = 0;
static int stream_ch = 1;
static int tx_speed = FWSPD_S400;
static int rx_queue_len = FWMAXQUEUE;

static MALLOC_DEFINE(M_FWE, "if_fwe", "Ethernet over FireWire interface");
SYSCTL_INT(_debug, OID_AUTO, if_fwe_debug, CTLFLAG_RWTUN, &fwedebug, 0, "");
SYSCTL_DECL(_hw_firewire);
static SYSCTL_NODE(_hw_firewire, OID_AUTO, fwe, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
    "Ethernet emulation subsystem");
SYSCTL_INT(_hw_firewire_fwe, OID_AUTO, stream_ch, CTLFLAG_RWTUN, &stream_ch, 0,
        "Stream channel to use");
SYSCTL_INT(_hw_firewire_fwe, OID_AUTO, tx_speed, CTLFLAG_RWTUN, &tx_speed, 0,
        "Transmission speed");
SYSCTL_INT(_hw_firewire_fwe, OID_AUTO, rx_queue_len, CTLFLAG_RWTUN, &rx_queue_len,
        0, "Length of the receive queue");

#ifdef DEVICE_POLLING
static poll_handler_t fwe_poll;

static int
fwe_poll(if_t ifp, enum poll_cmd cmd, int count)
{
        struct fwe_softc *fwe;
        struct firewire_comm *fc;

        if (!(if_getdrvflags(ifp) & IFF_DRV_RUNNING))
                return (0);

        fwe = ((struct fwe_eth_softc *)if_getsoftc(ifp))->fwe;
        fc = fwe->fd.fc;
        fc->poll(fc, (cmd == POLL_AND_CHECK_STATUS)?0:1, count);
        return (0);
}
#endif /* DEVICE_POLLING */

static void
fwe_identify(driver_t *driver, device_t parent)
{
        BUS_ADD_CHILD(parent, 0, "fwe", device_get_unit(parent));
}

static int
fwe_probe(device_t dev)
{
        device_t pa;

        if (fw_get_unit(dev) != NULL)
                return (ENXIO);

        pa = device_get_parent(dev);
        if (device_get_unit(dev) != device_get_unit(pa))
                return (ENXIO);

        device_set_desc(dev, "Ethernet over FireWire");
        return (0);
}

static int
fwe_attach(device_t dev)
{
        struct fwe_softc *fwe;
        if_t ifp;
        int unit;
        u_char eaddr[6];
        struct fw_eui64 *eui;

        fwe = ((struct fwe_softc *)device_get_softc(dev));
        unit = device_get_unit(dev);

        bzero(fwe, sizeof(struct fwe_softc));
        mtx_init(&fwe->mtx, "fwe", NULL, MTX_DEF);
        /* XXX */
        fwe->stream_ch = stream_ch;
        fwe->dma_ch = -1;

        fwe->fd.fc = fw_get_comm(dev);
        if (tx_speed < 0)
                tx_speed = fwe->fd.fc->speed;

        fwe->fd.dev = dev;
        fwe->fd.post_explore = NULL;
        fwe->eth_softc.fwe = fwe;

        fwe->pkt_hdr.mode.stream.tcode = FWTCODE_STREAM;
        fwe->pkt_hdr.mode.stream.sy = 0;
        fwe->pkt_hdr.mode.stream.chtag = fwe->stream_ch;

        /* generate fake MAC address: first and last 3bytes from eui64 */
#define LOCAL (0x02)
#define GROUP (0x01)

        eui = &fwe->fd.fc->eui;
        eaddr[0] = (FW_EUI64_BYTE(eui, 0) | LOCAL) & ~GROUP;
        eaddr[1] = FW_EUI64_BYTE(eui, 1);
        eaddr[2] = FW_EUI64_BYTE(eui, 2);
        eaddr[3] = FW_EUI64_BYTE(eui, 5);
        eaddr[4] = FW_EUI64_BYTE(eui, 6);
        eaddr[5] = FW_EUI64_BYTE(eui, 7);
        printf("if_fwe%d: Fake Ethernet address: "
                "%02x:%02x:%02x:%02x:%02x:%02x\n", unit,
                eaddr[0], eaddr[1], eaddr[2], eaddr[3], eaddr[4], eaddr[5]);

        /* fill the rest and attach interface */
        ifp = fwe->eth_softc.ifp = if_alloc(IFT_ETHER);
        if_setsoftc(ifp, &fwe->eth_softc);

        if_initname(ifp, device_get_name(dev), unit);
        if_setinitfn(ifp, fwe_init);
        if_setstartfn(ifp, fwe_start);
        if_setioctlfn(ifp, fwe_ioctl);
        if_setflags(ifp, (IFF_BROADCAST|IFF_SIMPLEX|IFF_MULTICAST));
        if_setsendqlen(ifp, TX_MAX_QUEUE);

        ether_ifattach(ifp, eaddr);

        /* Tell the upper layer(s) we support long frames. */
        if_setifheaderlen(ifp, sizeof(struct ether_vlan_header));
        if_setcapabilitiesbit(ifp, IFCAP_VLAN_MTU | IFCAP_POLLING, 0);
        if_setcapenablebit(ifp, IFCAP_VLAN_MTU, 0);

        FWEDEBUG(ifp, "interface created\n");
        return (0);
}

static void
fwe_stop(struct fwe_softc *fwe)
{
        struct firewire_comm *fc;
        struct fw_xferq *xferq;
        if_t ifp = fwe->eth_softc.ifp;
        int i;

        fc = fwe->fd.fc;

        if (fwe->dma_ch >= 0) {
                xferq = fc->ir[fwe->dma_ch];

                if (xferq->flag & FWXFERQ_RUNNING)
                        fc->irx_disable(fc, fwe->dma_ch);
                xferq->flag &=
                        ~(FWXFERQ_MODEMASK | FWXFERQ_OPEN | FWXFERQ_STREAM |
                        FWXFERQ_EXTBUF | FWXFERQ_HANDLER | FWXFERQ_CHTAGMASK);
                xferq->hand =  NULL;

                for (i = 0; i < xferq->bnchunk; i++)
                        m_freem(xferq->bulkxfer[i].mbuf);
                free(xferq->bulkxfer, M_FWE);

                FW_NET_FREE_XFERLIST(&fwe->xferlist);
                STAILQ_INIT(&fwe->xferlist);

                xferq->bulkxfer =  NULL;
                fwe->dma_ch = -1;
        }

        if_setdrvflagbits(ifp, 0, (IFF_DRV_RUNNING | IFF_DRV_OACTIVE));
}

static int
fwe_detach(device_t dev)
{
        struct fwe_softc *fwe;
        if_t ifp;

        fwe = device_get_softc(dev);
        ifp = fwe->eth_softc.ifp;

#ifdef DEVICE_POLLING
        if (if_getcapenable(ifp) & IFCAP_POLLING)
                ether_poll_deregister(ifp);
#endif

        fwe_stop(fwe);
        ether_ifdetach(ifp);
        if_free(ifp);

        mtx_destroy(&fwe->mtx);
        return 0;
}

static void
fwe_init(void *arg)
{
        struct fwe_softc *fwe = ((struct fwe_eth_softc *)arg)->fwe;
        struct firewire_comm *fc;
        if_t ifp = fwe->eth_softc.ifp;
        struct fw_xferq *xferq;
        struct fw_xfer *xfer;
        int i;

        FWEDEBUG(ifp, "initializing\n");

        /* keep promiscuous mode */
        if_setflagbits(ifp, IFF_PROMISC, 0);

        fc = fwe->fd.fc;
        if (fwe->dma_ch < 0) {
                fwe->dma_ch = fw_open_isodma(fc, /* tx */0);
                if (fwe->dma_ch < 0)
                        return;
                xferq = fc->ir[fwe->dma_ch];
                xferq->flag |= FWXFERQ_EXTBUF |
                                FWXFERQ_HANDLER | FWXFERQ_STREAM;
                fwe->stream_ch = stream_ch;
                fwe->pkt_hdr.mode.stream.chtag = fwe->stream_ch;
                xferq->flag &= ~0xff;
                xferq->flag |= fwe->stream_ch & 0xff;
                /* register fwe_input handler */
                xferq->sc = (caddr_t) fwe;
                xferq->hand = fwe_as_input;
                xferq->bnchunk = rx_queue_len;
                xferq->bnpacket = 1;
                xferq->psize = MCLBYTES;
                xferq->queued = 0;
                xferq->buf = NULL;
                xferq->bulkxfer = (struct fw_bulkxfer *) malloc(
                        sizeof(struct fw_bulkxfer) * xferq->bnchunk,
                                                        M_FWE, M_WAITOK);
                STAILQ_INIT(&xferq->stvalid);
                STAILQ_INIT(&xferq->stfree);
                STAILQ_INIT(&xferq->stdma);
                xferq->stproc = NULL;
                fw_net_init_iso_chunks(xferq);
                STAILQ_INIT(&fwe->xferlist);
                for (i = 0; i < TX_MAX_QUEUE; i++) {
                        xfer = fw_net_alloc_txfer(fwe->fd.fc, tx_speed,
                            fwe, fwe_output_callback, M_FWE);
                        if (xfer == NULL)
                                break;
                        STAILQ_INSERT_TAIL(&fwe->xferlist, xfer, link);
                }
        } else
                xferq = fc->ir[fwe->dma_ch];


        /* start dma */
        if ((xferq->flag & FWXFERQ_RUNNING) == 0)
                fc->irx_enable(fc, fwe->dma_ch);

        if_setdrvflagbits(ifp, IFF_DRV_RUNNING, 0);
        if_setdrvflagbits(ifp, 0, IFF_DRV_OACTIVE);

}


static int
fwe_ioctl(if_t ifp, u_long cmd, caddr_t data)
{
        struct fwe_softc *fwe = ((struct fwe_eth_softc *)if_getsoftc(ifp))->fwe;
        struct ifstat *ifs = NULL;
        int error;

        switch (cmd) {
                case SIOCSIFFLAGS:
                        if (if_getflags(ifp) & IFF_UP) {
                                if (!(if_getdrvflags(ifp) & IFF_DRV_RUNNING))
                                        fwe_init(&fwe->eth_softc);
                        } else {
                                if (if_getdrvflags(ifp) & IFF_DRV_RUNNING)
                                        fwe_stop(fwe);
                        }
                        /* keep promiscuous mode */
                        if_setflagbits(ifp, IFF_PROMISC, 0);
                        break;
                case SIOCADDMULTI:
                case SIOCDELMULTI:
                        break;

                case SIOCGIFSTATUS:
                        ifs = (struct ifstat *)data;
                        snprintf(ifs->ascii, sizeof(ifs->ascii),
                            "\tch %d dma %d\n", fwe->stream_ch, fwe->dma_ch);
                        break;
                case SIOCSIFCAP:
#ifdef DEVICE_POLLING
                    {
                        struct ifreq *ifr = (struct ifreq *) data;

                        error = fw_net_poll_ioctl(ifp, ifr,
                            fwe->fd.fc, fwe_poll);
                        if (error >= 0)
                                return (error);
                    }
#endif /* DEVICE_POLLING */
                        break;
                default:
                        error = ether_ioctl(ifp, cmd, data);
                        return (error);
        }

        return (0);
}

static void
fwe_output_callback(struct fw_xfer *xfer)
{
        struct fwe_softc *fwe;
        if_t ifp;

        fwe = (struct fwe_softc *)xfer->sc;
        ifp = fwe->eth_softc.ifp;
        /* XXX error check */
        FWEDEBUG(ifp, "resp = %d\n", xfer->resp);
        if (xfer->resp != 0)
                if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
        m_freem(xfer->mbuf);
        fw_xfer_unload(xfer);

        FWE_LOCK(fwe);
        STAILQ_INSERT_TAIL(&fwe->xferlist, xfer, link);
        FWE_UNLOCK(fwe);

        /* for queue full */
        if (!if_sendq_empty(ifp))
                fwe_start(ifp);
}

static void
fwe_start(if_t ifp)
{
        struct fwe_softc *fwe = ((struct fwe_eth_softc *)if_getsoftc(ifp))->fwe;

        FWEDEBUG(ifp, "starting\n");

        if (fwe->dma_ch < 0) {
                FWEDEBUG(ifp, "not ready\n");

                fw_net_drain_sendq(ifp);

                return;
        }

        if_setdrvflagbits(ifp, IFF_DRV_OACTIVE, 0);

        if (!if_sendq_empty(ifp))
                fwe_as_output(fwe, ifp);

        if_setdrvflagbits(ifp, 0, IFF_DRV_OACTIVE);
}

#define HDR_LEN 4
#ifndef ETHER_ALIGN
#define ETHER_ALIGN 2
#endif
/* Async. stream output */
static void
fwe_as_output(struct fwe_softc *fwe, if_t ifp)
{
        struct mbuf *m;
        struct fw_xfer *xfer;
        struct fw_xferq *xferq;
        struct fw_pkt *fp;
        int i = 0;

        xfer = NULL;
        xferq = fwe->fd.fc->atq;
        while ((xferq->queued < xferq->maxq - 1) &&
                        !if_sendq_empty(ifp)) {
                FWE_LOCK(fwe);
                xfer = STAILQ_FIRST(&fwe->xferlist);
                if (xfer == NULL) {
                        FWE_UNLOCK(fwe);
                        break;
                }
                STAILQ_REMOVE_HEAD(&fwe->xferlist, link);
                FWE_UNLOCK(fwe);

                m = if_dequeue(ifp);
                if (m == NULL) {
                        FWE_LOCK(fwe);
                        STAILQ_INSERT_HEAD(&fwe->xferlist, xfer, link);
                        FWE_UNLOCK(fwe);
                        break;
                }
                BPF_MTAP(ifp, m);

                /* keep ip packet alignment for alpha */
                M_PREPEND(m, ETHER_ALIGN, M_NOWAIT);
                fp = &xfer->send.hdr;
                *(uint32_t *)&xfer->send.hdr = *(int32_t *)&fwe->pkt_hdr;
                fp->mode.stream.len = m->m_pkthdr.len;
                xfer->mbuf = m;
                xfer->send.pay_len = m->m_pkthdr.len;

                if (fw_asyreq(fwe->fd.fc, -1, xfer) != 0) {
                        /* error */
                        if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
                        /* XXX set error code */
                        fwe_output_callback(xfer);
                } else {
                        if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
                        i++;
                }
        }
        if (i > 0)
                xferq->start(fwe->fd.fc);
}

/* Async. stream output */
static void
fwe_as_input(struct fw_xferq *xferq)
{
        struct mbuf *m, *m0;
        if_t ifp;
        struct fwe_softc *fwe;
        struct fw_bulkxfer *sxfer;
        struct fw_pkt *fp;
        struct epoch_tracker et;

        fwe = (struct fwe_softc *)xferq->sc;
        ifp = fwe->eth_softc.ifp;

        /* We do not need a lock here because the bottom half is serialized */
        while ((sxfer = STAILQ_FIRST(&xferq->stvalid)) != NULL) {
                STAILQ_REMOVE_HEAD(&xferq->stvalid, link);
                fp = mtod(sxfer->mbuf, struct fw_pkt *);
                if (fwe->fd.fc->irx_post != NULL)
                        fwe->fd.fc->irx_post(fwe->fd.fc, fp->mode.ld);
                m = sxfer->mbuf;

                /* insert new rbuf */
                sxfer->mbuf = m0 = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
                if (m0 != NULL) {
                        m0->m_len = m0->m_pkthdr.len = m0->m_ext.ext_size;
                        STAILQ_INSERT_TAIL(&xferq->stfree, sxfer, link);
                } else
                        printf("%s: m_getcl failed\n", __FUNCTION__);

                if (sxfer->resp != 0 || fp->mode.stream.len <
                    ETHER_ALIGN + sizeof(struct ether_header)) {
                        m_freem(m);
                        if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
                        continue;
                }

                m->m_data += HDR_LEN + ETHER_ALIGN;
                m->m_len = m->m_pkthdr.len = fp->mode.stream.len - ETHER_ALIGN;
                m->m_pkthdr.rcvif = ifp;
                NET_EPOCH_ENTER(et);
                if_input(ifp, m);
                NET_EPOCH_EXIT(et);
                if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
        }
        if (STAILQ_FIRST(&xferq->stfree) != NULL)
                fwe->fd.fc->irx_enable(fwe->fd.fc, fwe->dma_ch);
}


static device_method_t fwe_methods[] = {
        /* device interface */
        DEVMETHOD(device_identify,      fwe_identify),
        DEVMETHOD(device_probe,         fwe_probe),
        DEVMETHOD(device_attach,        fwe_attach),
        DEVMETHOD(device_detach,        fwe_detach),
        DEVMETHOD_END
};

static driver_t fwe_driver = {
        "fwe",
        fwe_methods,
        sizeof(struct fwe_softc),
};


DRIVER_MODULE(fwe, firewire, fwe_driver, 0, 0);
MODULE_VERSION(fwe, 1);
MODULE_DEPEND(fwe, firewire, 1, 1, 1);