/*      $OpenBSD: cbus.c,v 1.17 2021/10/24 17:05:03 mpi Exp $   */
/*
 * Copyright (c) 2008 Mark Kettenis
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/param.h>
#include <sys/device.h>
#include <sys/malloc.h>
#include <sys/systm.h>

#include <machine/autoconf.h>
#include <machine/hypervisor.h>
#include <machine/mdesc.h>
#include <machine/openfirm.h>

#include <sparc64/dev/cbusvar.h>
#include <sparc64/dev/vbusvar.h>

struct cbus_softc {
        struct device           sc_dv;
        bus_space_tag_t         sc_bustag;
        bus_dma_tag_t           sc_dmatag;

        uint64_t                sc_devhandle;

        /* Machine description. */
        int                     sc_idx;
};

int     cbus_match(struct device *, void *, void *);
void    cbus_attach(struct device *, struct device *, void *);
int     cbus_print(void *, const char *);

const struct cfattach cbus_ca = {
        sizeof(struct cbus_softc), cbus_match, cbus_attach
};

struct cfdriver cbus_cd = {
        NULL, "cbus", DV_DULL
};

void    *cbus_intr_establish(bus_space_tag_t, bus_space_tag_t, int, int, int,
    int (*)(void *), void *, const char *);
void    cbus_intr_ack(struct intrhand *);
bus_space_tag_t cbus_alloc_bus_tag(struct cbus_softc *, bus_space_tag_t);

int     cbus_get_channel_endpoint(struct cbus_softc *,
            struct cbus_attach_args *);

int
cbus_match(struct device *parent, void *match, void *aux)
{
        struct vbus_attach_args *va = aux;

        if (strcmp(va->va_name, "channel-devices") == 0)
                return (1);

        return (0);
}

void
cbus_attach(struct device *parent, struct device *self, void *aux)
{
        struct cbus_softc *sc = (struct cbus_softc *)self;
        struct vbus_attach_args *va = aux;
        int node;
        int reg;

        sc->sc_bustag = cbus_alloc_bus_tag(sc, va->va_bustag);
        sc->sc_dmatag = va->va_dmatag;

        if (OF_getprop(va->va_node, "reg", &reg, sizeof(reg)) != sizeof(reg))
                return;
        sc->sc_devhandle = reg;

        printf("\n");

        sc->sc_idx = mdesc_find(va->va_name, va->va_reg[0]);
        if (sc->sc_idx == -1)
                return;

        for (node = OF_child(va->va_node); node; node = OF_peer(node)) {
                struct cbus_attach_args ca;
                char buf[32];

                bzero(&ca, sizeof(ca));
                ca.ca_node = node;
                if (OF_getprop(node, "name", buf, sizeof(buf)) <= 0)
                        continue;
                ca.ca_name = buf;
                ca.ca_bustag = sc->sc_bustag;
                ca.ca_dmatag = sc->sc_dmatag;
                getprop(node, "reg", sizeof(*ca.ca_reg),
                    &ca.ca_nreg, (void **)&ca.ca_reg);
                if (cbus_get_channel_endpoint(sc, &ca) != 0)
                        continue;

                config_found(self, &ca, cbus_print);
        }
}

int
cbus_print(void *aux, const char *name)
{
        struct cbus_attach_args *ca = aux;

        if (name)
                printf("\"%s\" at %s", ca->ca_name, name);
        if (ca->ca_id != -1)
                printf(" chan 0x%llx", ca->ca_id);
        return (UNCONF);
}

int
cbus_intr_setstate(bus_space_tag_t t, uint64_t devino, uint64_t state)
{
        struct cbus_softc *sc = t->cookie;
        uint64_t devhandle = sc->sc_devhandle;
        int err;

        err = hv_vintr_setstate(devhandle, devino, state);
        if (err != H_EOK)
                return (-1);

        return (0);
}

int
cbus_intr_setenabled(bus_space_tag_t t, uint64_t devino, uint64_t enabled)
{
        struct cbus_softc *sc = t->cookie;
        uint64_t devhandle = sc->sc_devhandle;
        int err;

        err = hv_vintr_setenabled(devhandle, devino, enabled);
        if (err != H_EOK)
                return (-1);

        return (0);
}

void *
cbus_intr_establish(bus_space_tag_t t, bus_space_tag_t t0, int ihandle,
    int level, int flags, int (*handler)(void *), void *arg, const char *what)
{
        struct cbus_softc *sc = t0->cookie;
        uint64_t devhandle = sc->sc_devhandle;
        uint64_t devino = ihandle;
        struct intrhand *ih;
        int err;

        ih = bus_intr_allocate(t0, handler, arg, ihandle, level,
            NULL, NULL, what);
        if (ih == NULL)
                return (NULL);

        err = hv_vintr_setenabled(devhandle, devino, INTR_DISABLED);
        if (err != H_EOK) {
                printf("hv_vintr_setenabled: %d\n", err);
                return (NULL);
        }

        err = hv_vintr_setcookie(devhandle, devino, (vaddr_t)ih);
        if (err != H_EOK) {
                printf("hv_vintr_setcookie: %d\n", err);
                return (NULL);
        }

        if (flags & BUS_INTR_ESTABLISH_MPSAFE)
                ih->ih_mpsafe = 1;

        evcount_attach(&ih->ih_count, ih->ih_name, NULL);

        ih->ih_ack = cbus_intr_ack;
        ih->ih_cpu = cpus;

        err = hv_vintr_settarget(devhandle, devino, ih->ih_cpu->ci_upaid);
        if (err != H_EOK) {
                printf("hv_vintr_settarget: %d\n", err);
                return (NULL);
        }

        /* Clear pending interrupts. */
        err = hv_vintr_setstate(devhandle, devino, INTR_IDLE);
        if (err != H_EOK) {
                printf("hv_vintr_setstate: %d\n", err);
                return (NULL);
        }

        return (ih);
}

void
cbus_intr_ack(struct intrhand *ih)
{
        bus_space_tag_t t = ih->ih_bus;
        struct cbus_softc *sc = t->cookie;
        uint64_t devhandle = sc->sc_devhandle;
        uint64_t devino = ih->ih_number;

        hv_vintr_setstate(devhandle, devino, INTR_IDLE);
}

bus_space_tag_t
cbus_alloc_bus_tag(struct cbus_softc *sc, bus_space_tag_t parent)
{
        struct sparc_bus_space_tag *bt;

        bt = malloc(sizeof(*bt), M_DEVBUF, M_NOWAIT | M_ZERO);
        if (bt == NULL)
                panic("could not allocate cbus bus tag");

        strlcpy(bt->name, sc->sc_dv.dv_xname, sizeof(bt->name));
        bt->cookie = sc;
        bt->parent = parent;
        bt->asi = parent->asi;
        bt->sasi = parent->sasi;
        bt->sparc_bus_map = parent->sparc_bus_map;
        bt->sparc_intr_establish = cbus_intr_establish;

        return (bt);
}

int
cbus_get_channel_endpoint(struct cbus_softc *sc, struct cbus_attach_args *ca)
{
        struct md_header *hdr;
        struct md_element *elem;
        const char *name_blk;
        const char *str;
        int idx;
        int arc;

        idx = mdesc_find_child(sc->sc_idx, ca->ca_name, ca->ca_reg[0]);
        if (idx == -1)
                return (ENOENT);

        hdr = (struct md_header *)mdesc;
        elem = (struct md_element *)(mdesc + sizeof(struct md_header));
        name_blk = mdesc + sizeof(struct md_header) + hdr->node_blk_sz;

        ca->ca_idx = idx;

        ca->ca_id = -1;
        ca->ca_tx_ino = -1;
        ca->ca_rx_ino = -1;

        if (strcmp(ca->ca_name, "disk") != 0 &&
            strcmp(ca->ca_name, "network") != 0)
                return (0);

        for (; elem[idx].tag != 'E'; idx++) {
                str = name_blk + elem[idx].name_offset;
                if (elem[idx].tag != 'a' || strcmp(str, "fwd") != 0)
                        continue;

                arc = elem[idx].d.val;
                str = name_blk + elem[arc].name_offset;
                if (strcmp(str, "virtual-device-port") == 0) {
                        idx = arc;
                        continue;
                }

                if (strcmp(str, "channel-endpoint") == 0) {
                        ca->ca_id = mdesc_get_prop_val(arc, "id");
                        ca->ca_tx_ino = mdesc_get_prop_val(arc, "tx-ino");
                        ca->ca_rx_ino = mdesc_get_prop_val(arc, "rx-ino");
                        return (0);
                }
        }

        return (0);
}