/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2009 Andrew Thompson (thompsa@FreeBSD.org)
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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/cdefs.h>
#include <sys/epoch.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/condvar.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/sysctl.h>
#include <sys/sx.h>

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

#include <dev/mii/mii.h>
#include <dev/mii/miivar.h>

#include <dev/usb/usb.h>
#include <dev/usb/usbdi.h>

#include <dev/usb/usb_process.h>
#include <dev/usb/net/usb_ethernet.h>

#ifdef __HAIKU__
#define bus_topo_lock()
#define bus_topo_unlock()
#endif

#define UE_LOCK(_ue)            mtx_lock((_ue)->ue_mtx)
#define UE_UNLOCK(_ue)          mtx_unlock((_ue)->ue_mtx)
#define UE_LOCK_ASSERT(_ue, t)  mtx_assert((_ue)->ue_mtx, t)

static struct unrhdr *ueunit;

static usb_proc_callback_t ue_attach_post_task;
static usb_proc_callback_t ue_promisc_task;
static usb_proc_callback_t ue_setmulti_task;
static usb_proc_callback_t ue_ifmedia_task;
static usb_proc_callback_t ue_tick_task;
static usb_proc_callback_t ue_start_task;
static usb_proc_callback_t ue_stop_task;

static void     ue_init(void *);
static void     ue_start(if_t);
static int      ue_ifmedia_upd(if_t);
static void     ue_watchdog(void *);

/*
 * Return values:
 *    0: success
 * Else: device has been detached
 */
uint8_t
uether_pause(struct usb_ether *ue, unsigned _ticks)
{
        if (usb_proc_is_gone(&ue->ue_tq)) {
                /* nothing to do */
                return (1);
        }
        usb_pause_mtx(ue->ue_mtx, _ticks);
        return (0);
}

static void
ue_queue_command(struct usb_ether *ue,
    usb_proc_callback_t *fn,
    struct usb_proc_msg *t0, struct usb_proc_msg *t1)
{
        struct usb_ether_cfg_task *task;

        UE_LOCK_ASSERT(ue, MA_OWNED);

        if (usb_proc_is_gone(&ue->ue_tq)) {
                return;         /* nothing to do */
        }
        /* 
         * NOTE: The task cannot get executed before we drop the
         * "sc_mtx" mutex. It is safe to update fields in the message
         * structure after that the message got queued.
         */
        task = (struct usb_ether_cfg_task *)
          usb_proc_msignal(&ue->ue_tq, t0, t1);

        /* Setup callback and self pointers */
        task->hdr.pm_callback = fn;
        task->ue = ue;

        /*
         * Start and stop must be synchronous!
         */
        if ((fn == ue_start_task) || (fn == ue_stop_task)
#ifdef __HAIKU__
                        || (fn == ue_attach_post_task)
#endif
                        )
                usb_proc_mwait(&ue->ue_tq, t0, t1);
}

if_t 
uether_getifp(struct usb_ether *ue)
{
        return (ue->ue_ifp);
}

struct mii_data *
uether_getmii(struct usb_ether *ue)
{
        return (device_get_softc(ue->ue_miibus));
}

void *
uether_getsc(struct usb_ether *ue)
{
        return (ue->ue_sc);
}

#ifndef __HAIKU__
static int
ue_sysctl_parent(SYSCTL_HANDLER_ARGS)
{
        struct usb_ether *ue = arg1;
        const char *name;

        name = device_get_nameunit(ue->ue_dev);
        return SYSCTL_OUT_STR(req, name);
}
#endif

int
uether_ifattach(struct usb_ether *ue)
{
        int error;

        /* check some critical parameters */
        if ((ue->ue_dev == NULL) ||
            (ue->ue_udev == NULL) ||
            (ue->ue_mtx == NULL) ||
            (ue->ue_methods == NULL))
                return (EINVAL);

        error = usb_proc_create(&ue->ue_tq, ue->ue_mtx, 
            device_get_nameunit(ue->ue_dev), USB_PRI_MED);
        if (error) {
                device_printf(ue->ue_dev, "could not setup taskqueue\n");
                goto error;
        }

        /* fork rest of the attach code */
        UE_LOCK(ue);
        ue_queue_command(ue, ue_attach_post_task,
            &ue->ue_sync_task[0].hdr,
            &ue->ue_sync_task[1].hdr);
        UE_UNLOCK(ue);

error:
        return (error);
}

void
uether_ifattach_wait(struct usb_ether *ue)
{

        UE_LOCK(ue);
        usb_proc_mwait(&ue->ue_tq,
            &ue->ue_sync_task[0].hdr,
            &ue->ue_sync_task[1].hdr);
        UE_UNLOCK(ue);
}

static void
ue_attach_post_task(struct usb_proc_msg *_task)
{
        struct usb_ether_cfg_task *task =
            (struct usb_ether_cfg_task *)_task;
        struct usb_ether *ue = task->ue;
        if_t ifp;
        int error;
        char num[14];                   /* sufficient for 32 bits */

        /* first call driver's post attach routine */
        ue->ue_methods->ue_attach_post(ue);

        UE_UNLOCK(ue);

        ue->ue_unit = alloc_unr(ueunit);
        usb_callout_init_mtx(&ue->ue_watchdog, ue->ue_mtx, 0);
        sysctl_ctx_init(&ue->ue_sysctl_ctx);
        mbufq_init(&ue->ue_rxq, 0 /* unlimited length */);

        error = 0;
        ifp = if_alloc(IFT_ETHER);
        if_setsoftc(ifp, ue);
        if_initname(ifp, "ue", ue->ue_unit);
        if (ue->ue_methods->ue_attach_post_sub != NULL) {
                ue->ue_ifp = ifp;
                error = ue->ue_methods->ue_attach_post_sub(ue);
        } else {
                if_setflags(ifp, IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST);
                if (ue->ue_methods->ue_ioctl != NULL)
                        if_setioctlfn(ifp, ue->ue_methods->ue_ioctl);
                else
                        if_setioctlfn(ifp, uether_ioctl);
                if_setstartfn(ifp, ue_start);
                if_setinitfn(ifp, ue_init);
                if_setsendqlen(ifp, ifqmaxlen);
                if_setsendqready(ifp);
                ue->ue_ifp = ifp;

                if (ue->ue_methods->ue_mii_upd != NULL &&
                    ue->ue_methods->ue_mii_sts != NULL) {
                        bus_topo_lock();
                        error = mii_attach(ue->ue_dev, &ue->ue_miibus, ifp,
                            ue_ifmedia_upd, ue->ue_methods->ue_mii_sts,
                            BMSR_DEFCAPMASK, MII_PHY_ANY, MII_OFFSET_ANY, 0);
                        bus_topo_unlock();
                }
        }

        if (error) {
                device_printf(ue->ue_dev, "attaching PHYs failed\n");
                goto fail;
        }

        if_printf(ifp, "<USB Ethernet> on %s\n", device_get_nameunit(ue->ue_dev));
        ether_ifattach(ifp, ue->ue_eaddr);
        /* Tell upper layer we support VLAN oversized frames. */
        if (if_getcapabilities(ifp) & IFCAP_VLAN_MTU)
                if_setifheaderlen(ifp, sizeof(struct ether_vlan_header));

        snprintf(num, sizeof(num), "%u", ue->ue_unit);
#ifndef __HAIKU__
        ue->ue_sysctl_oid = SYSCTL_ADD_NODE(&ue->ue_sysctl_ctx,
            &SYSCTL_NODE_CHILDREN(_net, ue),
            OID_AUTO, num, CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
        SYSCTL_ADD_PROC(&ue->ue_sysctl_ctx,
            SYSCTL_CHILDREN(ue->ue_sysctl_oid), OID_AUTO, "%parent",
            CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, ue, 0,
            ue_sysctl_parent, "A", "parent device");
#endif

        UE_LOCK(ue);
        return;

fail:
        /* drain mbuf queue */
        mbufq_drain(&ue->ue_rxq);

        /* free unit */
        free_unr(ueunit, ue->ue_unit);
        if (ue->ue_ifp != NULL) {
                if_free(ue->ue_ifp);
                ue->ue_ifp = NULL;
        }
        UE_LOCK(ue);
        return;
}

void
uether_ifdetach(struct usb_ether *ue)
{
        if_t ifp;

        /* wait for any post attach or other command to complete */
        usb_proc_drain(&ue->ue_tq);

        /* read "ifnet" pointer after taskqueue drain */
        ifp = ue->ue_ifp;

        if (ifp != NULL) {
                /* we are not running any more */
                UE_LOCK(ue);
                if_setdrvflagbits(ifp, 0, IFF_DRV_RUNNING);
                UE_UNLOCK(ue);

                /* drain any callouts */
                usb_callout_drain(&ue->ue_watchdog);

                /*
                 * Detach ethernet first to stop miibus calls from
                 * user-space:
                 */
                ether_ifdetach(ifp);

                /* detach miibus */
                if (ue->ue_miibus != NULL) {
                        bus_topo_lock();
                        device_delete_child(ue->ue_dev, ue->ue_miibus);
                        bus_topo_unlock();
                }

                /* free interface instance */
                if_free(ifp);

                /* free sysctl */
                sysctl_ctx_free(&ue->ue_sysctl_ctx);

                /* drain mbuf queue */
                mbufq_drain(&ue->ue_rxq);

                /* free unit */
                free_unr(ueunit, ue->ue_unit);
        }

        /* free taskqueue, if any */
        usb_proc_free(&ue->ue_tq);
}

uint8_t
uether_is_gone(struct usb_ether *ue)
{
        return (usb_proc_is_gone(&ue->ue_tq));
}

void
uether_init(void *arg)
{

        ue_init(arg);
}

static void
ue_init(void *arg)
{
        struct usb_ether *ue = arg;

        UE_LOCK(ue);
        ue_queue_command(ue, ue_start_task,
            &ue->ue_sync_task[0].hdr, 
            &ue->ue_sync_task[1].hdr);
        UE_UNLOCK(ue);
}

static void
ue_start_task(struct usb_proc_msg *_task)
{
        struct usb_ether_cfg_task *task =
            (struct usb_ether_cfg_task *)_task;
        struct usb_ether *ue = task->ue;
        if_t ifp = ue->ue_ifp;

        UE_LOCK_ASSERT(ue, MA_OWNED);

        ue->ue_methods->ue_init(ue);

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

        if (ue->ue_methods->ue_tick != NULL)
                usb_callout_reset(&ue->ue_watchdog, hz, ue_watchdog, ue);
}

static void
ue_stop_task(struct usb_proc_msg *_task)
{
        struct usb_ether_cfg_task *task =
            (struct usb_ether_cfg_task *)_task;
        struct usb_ether *ue = task->ue;

        UE_LOCK_ASSERT(ue, MA_OWNED);

        usb_callout_stop(&ue->ue_watchdog);

        ue->ue_methods->ue_stop(ue);
}

void
uether_start(if_t ifp)
{

        ue_start(ifp);
}

static void
ue_start(if_t ifp)
{
        struct usb_ether *ue = if_getsoftc(ifp);

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

        UE_LOCK(ue);
        ue->ue_methods->ue_start(ue);
        UE_UNLOCK(ue);
}

static void
ue_promisc_task(struct usb_proc_msg *_task)
{
        struct usb_ether_cfg_task *task =
            (struct usb_ether_cfg_task *)_task;
        struct usb_ether *ue = task->ue;

        ue->ue_methods->ue_setpromisc(ue);
}

static void
ue_setmulti_task(struct usb_proc_msg *_task)
{
        struct usb_ether_cfg_task *task =
            (struct usb_ether_cfg_task *)_task;
        struct usb_ether *ue = task->ue;

        ue->ue_methods->ue_setmulti(ue);
}

int
uether_ifmedia_upd(if_t ifp)
{

        return (ue_ifmedia_upd(ifp));
}

static int
ue_ifmedia_upd(if_t ifp)
{
        struct usb_ether *ue = if_getsoftc(ifp);

        /* Defer to process context */
        UE_LOCK(ue);
        ue_queue_command(ue, ue_ifmedia_task,
            &ue->ue_media_task[0].hdr,
            &ue->ue_media_task[1].hdr);
        UE_UNLOCK(ue);

        return (0);
}

static void
ue_ifmedia_task(struct usb_proc_msg *_task)
{
        struct usb_ether_cfg_task *task =
            (struct usb_ether_cfg_task *)_task;
        struct usb_ether *ue = task->ue;
        if_t ifp = ue->ue_ifp;

        ue->ue_methods->ue_mii_upd(ifp);
}

static void
ue_watchdog(void *arg)
{
        struct usb_ether *ue = arg;
        if_t ifp = ue->ue_ifp;

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

        ue_queue_command(ue, ue_tick_task,
            &ue->ue_tick_task[0].hdr, 
            &ue->ue_tick_task[1].hdr);

        usb_callout_reset(&ue->ue_watchdog, hz, ue_watchdog, ue);
}

static void
ue_tick_task(struct usb_proc_msg *_task)
{
        struct usb_ether_cfg_task *task =
            (struct usb_ether_cfg_task *)_task;
        struct usb_ether *ue = task->ue;
        if_t ifp = ue->ue_ifp;

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

        ue->ue_methods->ue_tick(ue);
}

int
uether_ioctl(if_t ifp, u_long command, caddr_t data)
{
        struct usb_ether *ue = if_getsoftc(ifp);
        struct ifreq *ifr = (struct ifreq *)data;
        struct mii_data *mii;
        int error = 0;

        switch (command) {
        case SIOCSIFFLAGS:
                UE_LOCK(ue);
                if (if_getflags(ifp) & IFF_UP) {
                        if (if_getdrvflags(ifp) & IFF_DRV_RUNNING)
                                ue_queue_command(ue, ue_promisc_task,
                                    &ue->ue_promisc_task[0].hdr, 
                                    &ue->ue_promisc_task[1].hdr);
                        else
                                ue_queue_command(ue, ue_start_task,
                                    &ue->ue_sync_task[0].hdr, 
                                    &ue->ue_sync_task[1].hdr);
                } else {
                        ue_queue_command(ue, ue_stop_task,
                            &ue->ue_sync_task[0].hdr, 
                            &ue->ue_sync_task[1].hdr);
                }
                UE_UNLOCK(ue);
                break;
        case SIOCADDMULTI:
        case SIOCDELMULTI:
                UE_LOCK(ue);
                ue_queue_command(ue, ue_setmulti_task,
                    &ue->ue_multi_task[0].hdr, 
                    &ue->ue_multi_task[1].hdr);
                UE_UNLOCK(ue);
                break;
        case SIOCGIFMEDIA:
        case SIOCSIFMEDIA:
                if (ue->ue_miibus != NULL) {
                        mii = device_get_softc(ue->ue_miibus);
                        error = ifmedia_ioctl(ifp, ifr, &mii->mii_media, command);
                } else
                        error = ether_ioctl(ifp, command, data);
                break;
        default:
                error = ether_ioctl(ifp, command, data);
                break;
        }
        return (error);
}

#ifdef __HAIKU__
static void
init_ue_unrhdr(void *arg)
{
        // TODO: RadixBitmap can't handle INT_MAX limit.
        ueunit = new_unrhdr(0, INT_MAX/16, NULL);
}

static void
uninit_ue_unrhdr(void *arg)
{
        delete_unrhdr(ueunit);
}

SYSINIT(init_ue_unrhdr, SI_SUB_INIT_IF, SI_ORDER_SECOND, init_ue_unrhdr, NULL);
SYSUNINIT(init_ue_unrhdr, SI_SUB_INIT_IF, SI_ORDER_SECOND, uninit_ue_unrhdr, NULL);
#else
static int
uether_modevent(module_t mod, int type, void *data)
{

        switch (type) {
        case MOD_LOAD:
                ueunit = new_unrhdr(0, INT_MAX, NULL);
                break;
        case MOD_UNLOAD:
                break;
        default:
                return (EOPNOTSUPP);
        }
        return (0);
}
static moduledata_t uether_mod = {
        "uether",
        uether_modevent,
        0
};
#endif

struct mbuf *
uether_newbuf(void)
{
        struct mbuf *m_new;

        m_new = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
        if (m_new == NULL)
                return (NULL);
        m_new->m_len = m_new->m_pkthdr.len = MCLBYTES;

        m_adj(m_new, ETHER_ALIGN);
        return (m_new);
}

int
uether_rxmbuf(struct usb_ether *ue, struct mbuf *m, 
    unsigned len)
{
        if_t ifp = ue->ue_ifp;

        UE_LOCK_ASSERT(ue, MA_OWNED);

        /* finalize mbuf */
        if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
        m->m_pkthdr.rcvif = ifp;
        m->m_pkthdr.len = m->m_len = len;

        /* enqueue for later when the lock can be released */
        (void)mbufq_enqueue(&ue->ue_rxq, m);
        return (0);
}

int
uether_rxbuf(struct usb_ether *ue, struct usb_page_cache *pc, 
    unsigned offset, unsigned len)
{
        if_t ifp = ue->ue_ifp;
        struct mbuf *m;

        UE_LOCK_ASSERT(ue, MA_OWNED);

        if (len < ETHER_HDR_LEN || len > MCLBYTES - ETHER_ALIGN)
                return (1);

        m = uether_newbuf();
        if (m == NULL) {
                if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
                return (ENOMEM);
        }

        usbd_copy_out(pc, offset, mtod(m, uint8_t *), len);

        /* finalize mbuf */
        if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
        m->m_pkthdr.rcvif = ifp;
        m->m_pkthdr.len = m->m_len = len;

        /* enqueue for later when the lock can be released */
        (void)mbufq_enqueue(&ue->ue_rxq, m);
        return (0);
}

void
uether_rxflush(struct usb_ether *ue)
{
        if_t ifp = ue->ue_ifp;
        struct epoch_tracker et;
        struct mbuf *m, *n;

        UE_LOCK_ASSERT(ue, MA_OWNED);

        n = mbufq_flush(&ue->ue_rxq);
        UE_UNLOCK(ue);
        NET_EPOCH_ENTER(et);
        while ((m = n) != NULL) {
                n = STAILQ_NEXT(m, m_stailqpkt);
                m->m_nextpkt = NULL;
                if_input(ifp, m);
        }
        NET_EPOCH_EXIT(et);
        UE_LOCK(ue);
}

#ifndef __HAIKU__
/*
 * USB net drivers are run by DRIVER_MODULE() thus SI_SUB_DRIVERS,
 * SI_ORDER_MIDDLE.  Run uether after that.
 */
DECLARE_MODULE(uether, uether_mod, SI_SUB_DRIVERS, SI_ORDER_ANY);
MODULE_VERSION(uether, 1);
#endif