/*-
 * Copyright (c) 2015, 2019 Marcel Moolenaar
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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/param.h>
#include <sys/systm.h>
#include <machine/bus.h>
#include <machine/bus_dma.h>
#include <machine/resource.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/proc.h>
#include <sys/queue.h>
#include <sys/rman.h>
#include <sys/sbuf.h>
#include <sys/sx.h>
#include <sys/uio.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>

#include <dev/proto/proto.h>
#include <dev/proto/proto_dev.h>
#include <dev/proto/proto_busdma.h>

MALLOC_DEFINE(M_PROTO_BUSDMA, "proto_busdma", "DMA management data");

#define BNDRY_MIN(a, b)         \
        (((a) == 0) ? (b) : (((b) == 0) ? (a) : MIN((a), (b))))

struct proto_callback_bundle {
        struct proto_busdma *busdma;
        struct proto_md *md;
        struct proto_ioc_busdma *ioc;
};

static int
proto_busdma_tag_create(struct proto_busdma *busdma, struct proto_tag *parent,
    struct proto_ioc_busdma *ioc)
{
        struct proto_tag *tag;

        /* Make sure that when a boundary is specified, it's a power of 2 */
        if (ioc->u.tag.bndry != 0 &&
            (ioc->u.tag.bndry & (ioc->u.tag.bndry - 1)) != 0)
                return (EINVAL);

        /*
         * If nsegs is 1, ignore maxsegsz. What this means is that if we have
         * just 1 segment, then maxsz should be equal to maxsegsz. To keep it
         * simple for us, limit maxsegsz to maxsz in any case.
         */
        if (ioc->u.tag.maxsegsz > ioc->u.tag.maxsz || ioc->u.tag.nsegs == 1)
                ioc->u.tag.maxsegsz = ioc->u.tag.maxsz;

        tag = malloc(sizeof(*tag), M_PROTO_BUSDMA, M_WAITOK | M_ZERO);
        if (parent != NULL) {
                tag->parent = parent;
                LIST_INSERT_HEAD(&parent->children, tag, peers);
                tag->align = MAX(ioc->u.tag.align, parent->align);
                tag->bndry = BNDRY_MIN(ioc->u.tag.bndry, parent->bndry);
                tag->maxaddr = MIN(ioc->u.tag.maxaddr, parent->maxaddr);
                tag->maxsz = MIN(ioc->u.tag.maxsz, parent->maxsz);
                tag->maxsegsz = MIN(ioc->u.tag.maxsegsz, parent->maxsegsz);
                tag->nsegs = MIN(ioc->u.tag.nsegs, parent->nsegs);
                tag->datarate = MIN(ioc->u.tag.datarate, parent->datarate);
                /* Write constraints back */
                ioc->u.tag.align = tag->align;
                ioc->u.tag.bndry = tag->bndry;
                ioc->u.tag.maxaddr = tag->maxaddr;
                ioc->u.tag.maxsz = tag->maxsz;
                ioc->u.tag.maxsegsz = tag->maxsegsz;
                ioc->u.tag.nsegs = tag->nsegs;
                ioc->u.tag.datarate = tag->datarate;
        } else {
                tag->align = ioc->u.tag.align;
                tag->bndry = ioc->u.tag.bndry;
                tag->maxaddr = ioc->u.tag.maxaddr;
                tag->maxsz = ioc->u.tag.maxsz;
                tag->maxsegsz = ioc->u.tag.maxsegsz;
                tag->nsegs = ioc->u.tag.nsegs;
                tag->datarate = ioc->u.tag.datarate;
        }
        LIST_INSERT_HEAD(&busdma->tags, tag, tags);
        ioc->result = (uintptr_t)(void *)tag;
        return (0);
}

static int
proto_busdma_tag_destroy(struct proto_busdma *busdma, struct proto_tag *tag)
{

        if (!LIST_EMPTY(&tag->mds))
                return (EBUSY);
        if (!LIST_EMPTY(&tag->children))
                return (EBUSY);

        if (tag->parent != NULL) {
                LIST_REMOVE(tag, peers);
                tag->parent = NULL;
        }
        LIST_REMOVE(tag, tags);
        free(tag, M_PROTO_BUSDMA);
        return (0);
}

static struct proto_tag *
proto_busdma_tag_lookup(struct proto_busdma *busdma, u_long key)
{
        struct proto_tag *tag;

        LIST_FOREACH(tag, &busdma->tags, tags) {
                if ((void *)tag == (void *)key)
                        return (tag);
        }
        return (NULL);
}

static int
proto_busdma_md_destroy_internal(struct proto_busdma *busdma,
    struct proto_md *md)
{

        LIST_REMOVE(md, mds);
        LIST_REMOVE(md, peers);
        if (md->physaddr)
                bus_dmamap_unload(md->bd_tag, md->bd_map);
        if (md->virtaddr != NULL)
                bus_dmamem_free(md->bd_tag, md->virtaddr, md->bd_map);
        else
                bus_dmamap_destroy(md->bd_tag, md->bd_map);
        bus_dma_tag_destroy(md->bd_tag);
        free(md, M_PROTO_BUSDMA);
        return (0);
}

static void
proto_busdma_mem_alloc_callback(void *arg, bus_dma_segment_t *segs, int nseg,
    int error)
{
        struct proto_callback_bundle *pcb = arg;

        pcb->ioc->u.md.bus_nsegs = nseg;
        pcb->ioc->u.md.bus_addr = segs[0].ds_addr;
}

static int
proto_busdma_mem_alloc(struct proto_busdma *busdma, struct proto_tag *tag,
    struct proto_ioc_busdma *ioc)
{
        struct proto_callback_bundle pcb;
        struct proto_md *md;
        int error;

        md = malloc(sizeof(*md), M_PROTO_BUSDMA, M_WAITOK | M_ZERO);
        md->tag = tag;

        error = bus_dma_tag_create(busdma->bd_roottag, tag->align, tag->bndry,
            tag->maxaddr, BUS_SPACE_MAXADDR, NULL, NULL, tag->maxsz,
            tag->nsegs, tag->maxsegsz, 0, NULL, NULL, &md->bd_tag);
        if (error) {
                free(md, M_PROTO_BUSDMA);
                return (error);
        }
        error = bus_dmamem_alloc(md->bd_tag, &md->virtaddr, 0, &md->bd_map);
        if (error) {
                bus_dma_tag_destroy(md->bd_tag);
                free(md, M_PROTO_BUSDMA);
                return (error);
        }
        md->physaddr = pmap_kextract((uintptr_t)(md->virtaddr));
        pcb.busdma = busdma;
        pcb.md = md;
        pcb.ioc = ioc;
        error = bus_dmamap_load(md->bd_tag, md->bd_map, md->virtaddr,
            tag->maxsz, proto_busdma_mem_alloc_callback, &pcb, BUS_DMA_NOWAIT);
        if (error) {
                bus_dmamem_free(md->bd_tag, md->virtaddr, md->bd_map);
                bus_dma_tag_destroy(md->bd_tag);
                free(md, M_PROTO_BUSDMA);
                return (error);
        }
        LIST_INSERT_HEAD(&tag->mds, md, peers);
        LIST_INSERT_HEAD(&busdma->mds, md, mds);
        ioc->u.md.virt_addr = (uintptr_t)md->virtaddr;
        ioc->u.md.virt_size = tag->maxsz;
        ioc->u.md.phys_nsegs = 1;
        ioc->u.md.phys_addr = md->physaddr;
        ioc->result = (uintptr_t)(void *)md;
        return (0);
}

static int
proto_busdma_mem_free(struct proto_busdma *busdma, struct proto_md *md)
{

        if (md->virtaddr == NULL)
                return (ENXIO);
        return (proto_busdma_md_destroy_internal(busdma, md));
}

static int
proto_busdma_md_create(struct proto_busdma *busdma, struct proto_tag *tag,
    struct proto_ioc_busdma *ioc)
{
        struct proto_md *md;
        int error;

        md = malloc(sizeof(*md), M_PROTO_BUSDMA, M_WAITOK | M_ZERO);
        md->tag = tag;

        error = bus_dma_tag_create(busdma->bd_roottag, tag->align, tag->bndry,
            tag->maxaddr, BUS_SPACE_MAXADDR, NULL, NULL, tag->maxsz,
            tag->nsegs, tag->maxsegsz, 0, NULL, NULL, &md->bd_tag);
        if (error) {
                free(md, M_PROTO_BUSDMA);
                return (error);
        }
        error = bus_dmamap_create(md->bd_tag, 0, &md->bd_map);
        if (error) {
                bus_dma_tag_destroy(md->bd_tag);
                free(md, M_PROTO_BUSDMA);
                return (error);
        }

        LIST_INSERT_HEAD(&tag->mds, md, peers);
        LIST_INSERT_HEAD(&busdma->mds, md, mds);
        ioc->result = (uintptr_t)(void *)md;
        return (0);
}

static int
proto_busdma_md_destroy(struct proto_busdma *busdma, struct proto_md *md)
{

        if (md->virtaddr != NULL)
                return (ENXIO);
        return (proto_busdma_md_destroy_internal(busdma, md));
}

static void
proto_busdma_md_load_callback(void *arg, bus_dma_segment_t *segs, int nseg,
    bus_size_t sz, int error)
{
        struct proto_callback_bundle *pcb = arg;

        pcb->ioc->u.md.bus_nsegs = nseg;
        pcb->ioc->u.md.bus_addr = segs[0].ds_addr;
}

static int
proto_busdma_md_load(struct proto_busdma *busdma, struct proto_md *md,
    struct proto_ioc_busdma *ioc, struct thread *td)
{
        struct proto_callback_bundle pcb;
        struct iovec iov;
        struct uio uio;
        pmap_t pmap;
        int error;

        iov.iov_base = (void *)(uintptr_t)ioc->u.md.virt_addr;
        iov.iov_len = ioc->u.md.virt_size;
        uio.uio_iov = &iov;
        uio.uio_iovcnt = 1;
        uio.uio_offset = 0;
        uio.uio_resid = iov.iov_len;
        uio.uio_segflg = UIO_USERSPACE;
        uio.uio_rw = UIO_READ;
        uio.uio_td = td;

        pcb.busdma = busdma;
        pcb.md = md;
        pcb.ioc = ioc;
        error = bus_dmamap_load_uio(md->bd_tag, md->bd_map, &uio,
            proto_busdma_md_load_callback, &pcb, BUS_DMA_NOWAIT);
        if (error)
                return (error);

        /* XXX determine *all* physical memory segments */
        pmap = vmspace_pmap(td->td_proc->p_vmspace);
        md->physaddr = pmap_extract(pmap, ioc->u.md.virt_addr);
        ioc->u.md.phys_nsegs = 1;       /* XXX */
        ioc->u.md.phys_addr = md->physaddr;
        return (0);
}

static int
proto_busdma_md_unload(struct proto_busdma *busdma, struct proto_md *md)
{

        if (!md->physaddr)
                return (ENXIO);
        bus_dmamap_unload(md->bd_tag, md->bd_map);
        md->physaddr = 0;
        return (0);
}

static int
proto_busdma_sync(struct proto_busdma *busdma, struct proto_md *md,
    struct proto_ioc_busdma *ioc)
{
        u_int ops;

        ops = BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE |
            BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE;
        if (ioc->u.sync.op & ~ops)
                return (EINVAL);
        if (!md->physaddr)
                return (ENXIO);
        bus_dmamap_sync(md->bd_tag, md->bd_map, ioc->u.sync.op);
        return (0);
}

static struct proto_md *
proto_busdma_md_lookup(struct proto_busdma *busdma, u_long key)
{
        struct proto_md *md;

        LIST_FOREACH(md, &busdma->mds, mds) {
                if ((void *)md == (void *)key)
                        return (md);
        }
        return (NULL);
}

struct proto_busdma *
proto_busdma_attach(struct proto_softc *sc)
{
        struct proto_busdma *busdma;

        busdma = malloc(sizeof(*busdma), M_PROTO_BUSDMA, M_WAITOK | M_ZERO);
        sx_init(&busdma->sxlck, "proto-busdma");
        return (busdma);
}

int
proto_busdma_detach(struct proto_softc *sc, struct proto_busdma *busdma)
{

        proto_busdma_cleanup(sc, busdma);
        sx_destroy(&busdma->sxlck);
        free(busdma, M_PROTO_BUSDMA);
        return (0);
}

int
proto_busdma_cleanup(struct proto_softc *sc, struct proto_busdma *busdma)
{
        struct proto_md *md, *md1;
        struct proto_tag *tag, *tag1;

        sx_xlock(&busdma->sxlck);
        LIST_FOREACH_SAFE(md, &busdma->mds, mds, md1)
                proto_busdma_md_destroy_internal(busdma, md);
        LIST_FOREACH_SAFE(tag, &busdma->tags, tags, tag1)
                proto_busdma_tag_destroy(busdma, tag);
        sx_xunlock(&busdma->sxlck);
        return (0);
}

int
proto_busdma_ioctl(struct proto_softc *sc, struct proto_busdma *busdma,
    struct proto_ioc_busdma *ioc, struct thread *td)
{
        struct proto_tag *tag;
        struct proto_md *md;
        int error;

        sx_xlock(&busdma->sxlck);

        error = 0;
        switch (ioc->request) {
        case PROTO_IOC_BUSDMA_TAG_CREATE:
                busdma->bd_roottag = bus_get_dma_tag(sc->sc_dev);
                error = proto_busdma_tag_create(busdma, NULL, ioc);
                break;
        case PROTO_IOC_BUSDMA_TAG_DERIVE:
                tag = proto_busdma_tag_lookup(busdma, ioc->key);
                if (tag == NULL) {
                        error = EINVAL;
                        break;
                }
                error = proto_busdma_tag_create(busdma, tag, ioc);
                break;
        case PROTO_IOC_BUSDMA_TAG_DESTROY:
                tag = proto_busdma_tag_lookup(busdma, ioc->key);
                if (tag == NULL) {
                        error = EINVAL;
                        break;
                }
                error = proto_busdma_tag_destroy(busdma, tag);
                break;
        case PROTO_IOC_BUSDMA_MEM_ALLOC:
                tag = proto_busdma_tag_lookup(busdma, ioc->u.md.tag);
                if (tag == NULL) {
                        error = EINVAL;
                        break;
                }
                error = proto_busdma_mem_alloc(busdma, tag, ioc);
                break;
        case PROTO_IOC_BUSDMA_MEM_FREE:
                md = proto_busdma_md_lookup(busdma, ioc->key);
                if (md == NULL) {
                        error = EINVAL;
                        break;
                }
                error = proto_busdma_mem_free(busdma, md);
                break;
        case PROTO_IOC_BUSDMA_MD_CREATE:
                tag = proto_busdma_tag_lookup(busdma, ioc->u.md.tag);
                if (tag == NULL) {
                        error = EINVAL;
                        break;
                }
                error = proto_busdma_md_create(busdma, tag, ioc);
                break;
        case PROTO_IOC_BUSDMA_MD_DESTROY:
                md = proto_busdma_md_lookup(busdma, ioc->key);
                if (md == NULL) {
                        error = EINVAL;
                        break;
                }
                error = proto_busdma_md_destroy(busdma, md);
                break;
        case PROTO_IOC_BUSDMA_MD_LOAD:
                md = proto_busdma_md_lookup(busdma, ioc->key);
                if (md == NULL) {
                        error = EINVAL;
                        break;
                }
                error = proto_busdma_md_load(busdma, md, ioc, td);
                break;
        case PROTO_IOC_BUSDMA_MD_UNLOAD:
                md = proto_busdma_md_lookup(busdma, ioc->key);
                if (md == NULL) {
                        error = EINVAL;
                        break;
                }
                error = proto_busdma_md_unload(busdma, md);
                break;
        case PROTO_IOC_BUSDMA_SYNC:
                md = proto_busdma_md_lookup(busdma, ioc->key);
                if (md == NULL) {
                        error = EINVAL;
                        break;
                }
                error = proto_busdma_sync(busdma, md, ioc);
                break;
        default:
                error = EINVAL;
                break;
        }

        sx_xunlock(&busdma->sxlck);

        return (error);
}

int
proto_busdma_mmap_allowed(struct proto_busdma *busdma, vm_paddr_t physaddr)
{
        struct proto_md *md;
        int result;

        sx_xlock(&busdma->sxlck);

        result = 0;
        LIST_FOREACH(md, &busdma->mds, mds) {
                if (physaddr >= trunc_page(md->physaddr) &&
                    physaddr <= trunc_page(md->physaddr + md->tag->maxsz)) {
                        result = 1;
                        break;
                }
        }

        sx_xunlock(&busdma->sxlck);

        return (result);
}