/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2010-2016 Solarflare Communications Inc.
 * All rights reserved.
 *
 * This software was developed in part by Philip Paeps under contract for
 * Solarflare Communications, Inc.
 *
 * 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 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 OWNER 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.
 *
 * The views and conclusions contained in the software and documentation are
 * those of the authors and should not be interpreted as representing official
 * policies, either expressed or implied, of the FreeBSD Project.
 */

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/queue.h>
#include <sys/taskqueue.h>

#include <machine/bus.h>

#include "common/efx.h"

#include "sfxge.h"

static void
sfxge_dma_cb(void *arg, bus_dma_segment_t *segs, int nseg, int error)
{
        bus_addr_t *addr;

        addr = arg;

        if (error != 0) {
                *addr = 0;
                return;
        }

        *addr = segs[0].ds_addr;
}

int
sfxge_dma_map_sg_collapse(bus_dma_tag_t tag, bus_dmamap_t map,
                          struct mbuf **mp, bus_dma_segment_t *segs,
                          int *nsegs, int maxsegs)
{
        bus_dma_segment_t *psegs;
        struct mbuf *m;
        int seg_count;
        int defragged;
        int err;

        m = *mp;
        defragged = err = seg_count = 0;

        KASSERT(m->m_pkthdr.len, ("packet has zero header length"));

retry:
        psegs = segs;
        seg_count = 0;
        if (m->m_next == NULL) {
                sfxge_map_mbuf_fast(tag, map, m, segs);
                *nsegs = 1;
                return (0);
        }
#if defined(__i386__) || defined(__amd64__)
        while (m != NULL && seg_count < maxsegs) {
                /*
                 * firmware doesn't like empty segments
                 */
                if (m->m_len != 0) {
                        seg_count++;
                        sfxge_map_mbuf_fast(tag, map, m, psegs);
                        psegs++;
                }
                m = m->m_next;
        }
#else
        err = bus_dmamap_load_mbuf_sg(tag, map, *mp, segs, &seg_count, 0);
#endif
        if (seg_count == 0) {
                err = EFBIG;
                goto err_out;
        } else if (err == EFBIG || seg_count >= maxsegs) {
                if (!defragged) {
                        m = m_defrag(*mp, M_NOWAIT);
                        if (m == NULL) {
                                err = ENOBUFS;
                                goto err_out;
                        }
                        *mp = m;
                        defragged = 1;
                        goto retry;
                }
                err = EFBIG;
                goto err_out;
        }
        *nsegs = seg_count;

err_out:
        return (err);
}

void
sfxge_dma_free(efsys_mem_t *esmp)
{

        bus_dmamap_unload(esmp->esm_tag, esmp->esm_map);
        bus_dmamem_free(esmp->esm_tag, esmp->esm_base, esmp->esm_map);
        bus_dma_tag_destroy(esmp->esm_tag);

        esmp->esm_addr = 0;
        esmp->esm_base = NULL;
        esmp->esm_size = 0;
}

int
sfxge_dma_alloc(struct sfxge_softc *sc, bus_size_t len, efsys_mem_t *esmp)
{
        void *vaddr;

        /* Create the child DMA tag. */
        if (bus_dma_tag_create(sc->parent_dma_tag, PAGE_SIZE, 0,
            MIN(0x3FFFFFFFFFFFUL, BUS_SPACE_MAXADDR), BUS_SPACE_MAXADDR, NULL,
            NULL, len, 1, len, 0, NULL, NULL, &esmp->esm_tag) != 0) {
                device_printf(sc->dev, "Couldn't allocate txq DMA tag\n");
                goto fail_tag_create;
        }

        /* Allocate kernel memory. */
        if (bus_dmamem_alloc(esmp->esm_tag, (void **)&vaddr,
            BUS_DMA_WAITOK | BUS_DMA_COHERENT | BUS_DMA_ZERO,
            &esmp->esm_map) != 0) {
                device_printf(sc->dev, "Couldn't allocate DMA memory\n");
                goto fail_alloc;
        }

        /* Load map into device memory. */
        if (bus_dmamap_load(esmp->esm_tag, esmp->esm_map, vaddr, len,
            sfxge_dma_cb, &esmp->esm_addr, 0) != 0) {
                device_printf(sc->dev, "Couldn't load DMA mapping\n");
                goto fail_load;
        }

        /*
         * The callback gets error information about the mapping
         * and will have set esm_addr to 0 if something went
         * wrong.
         */
        if (esmp->esm_addr == 0)
                goto fail_load_check;

        esmp->esm_base = vaddr;
        esmp->esm_size = len;

        return (0);

fail_load_check:
fail_load:
        bus_dmamem_free(esmp->esm_tag, vaddr, esmp->esm_map);
fail_alloc:
        bus_dma_tag_destroy(esmp->esm_tag);
fail_tag_create:
        return (ENOMEM);
}

void
sfxge_dma_fini(struct sfxge_softc *sc)
{

        bus_dma_tag_destroy(sc->parent_dma_tag);
}

int
sfxge_dma_init(struct sfxge_softc *sc)
{

        /* Create the parent dma tag. */
        if (bus_dma_tag_create(bus_get_dma_tag(sc->dev),        /* parent */
            1, 0,                       /* algnmnt, boundary */
            BUS_SPACE_MAXADDR,          /* lowaddr */
            BUS_SPACE_MAXADDR,          /* highaddr */
            NULL, NULL,                 /* filter, filterarg */
            BUS_SPACE_MAXSIZE_32BIT,    /* maxsize */
            BUS_SPACE_UNRESTRICTED,     /* nsegments */
            BUS_SPACE_MAXSIZE_32BIT,    /* maxsegsize */
            0,                          /* flags */
            NULL, NULL,                 /* lock, lockarg */
            &sc->parent_dma_tag) != 0) {
                device_printf(sc->dev, "Cannot allocate parent DMA tag\n");
                return (ENOMEM);
        }

        return (0);
}