/*-
 * Copyright (c) 2017-2019 Ruslan Bukin <br@bsdpad.com>
 * All rights reserved.
 *
 * This software was developed by SRI International and the University of
 * Cambridge Computer Laboratory under DARPA/AFRL contract FA8750-10-C-0237
 * ("CTSRD"), as part of the DARPA CRASH research programme.
 *
 * 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 "opt_platform.h"
#include <sys/param.h>
#include <sys/conf.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mbuf.h>
#include <sys/mutex.h>

#include <machine/bus.h>

#ifdef FDT
#include <dev/fdt/fdt_common.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#endif

#include <dev/xdma/xdma.h>

int
xdma_dequeue_mbuf(xdma_channel_t *xchan, struct mbuf **mp,
    xdma_transfer_status_t *status)
{
        struct xdma_request *xr;
        struct xdma_request *xr_tmp;

        QUEUE_OUT_LOCK(xchan);
        TAILQ_FOREACH_SAFE(xr, &xchan->queue_out, xr_next, xr_tmp) {
                TAILQ_REMOVE(&xchan->queue_out, xr, xr_next);
                break;
        }
        QUEUE_OUT_UNLOCK(xchan);

        if (xr == NULL)
                return (-1);

        *mp = xr->m;
        status->error = xr->status.error;
        status->transferred = xr->status.transferred;

        xchan_bank_put(xchan, xr);

        return (0);
}

int
xdma_enqueue_mbuf(xdma_channel_t *xchan, struct mbuf **mp,
    uintptr_t addr, uint8_t src_width, uint8_t dst_width,
    enum xdma_direction dir)
{
        struct xdma_request *xr;

        xr = xchan_bank_get(xchan);
        if (xr == NULL)
                return (-1); /* No space is available yet. */

        xr->direction = dir;
        xr->m = *mp;
        xr->req_type = XR_TYPE_MBUF;
        if (dir == XDMA_MEM_TO_DEV) {
                xr->dst_addr = addr;
                xr->src_addr = 0;
        } else {
                xr->src_addr = addr;
                xr->dst_addr = 0;
        }
        xr->src_width = src_width;
        xr->dst_width = dst_width;

        QUEUE_IN_LOCK(xchan);
        TAILQ_INSERT_TAIL(&xchan->queue_in, xr, xr_next);
        QUEUE_IN_UNLOCK(xchan);

        return (0);
}

uint32_t
xdma_mbuf_chain_count(struct mbuf *m0)
{
        struct mbuf *m;
        uint32_t c;

        c = 0;

        for (m = m0; m != NULL; m = m->m_next)
                c++;

        return (c);
}

uint32_t
xdma_mbuf_defrag(xdma_channel_t *xchan, struct xdma_request *xr)
{
        xdma_controller_t *xdma;
        struct mbuf *m;
        uint32_t c;

        xdma = xchan->xdma;

        c = xdma_mbuf_chain_count(xr->m);
        if (c == 1)
                return (c); /* Nothing to do. */

        if ((m = m_defrag(xr->m, M_NOWAIT)) == NULL) {
                device_printf(xdma->dma_dev,
                    "%s: Can't defrag mbuf\n",
                    __func__);
                return (c);
        }

        xr->m = m;
        c = 1;

        return (c);
}