/*      $OpenBSD: bus_dma.c,v 1.14 2018/01/11 15:49:34 visa Exp $       */
/*      $NetBSD: bus_dma.c,v 1.1 2006/09/01 21:26:18 uwe Exp $  */

/*
 * Copyright (c) 2005 NONAKA Kimihiro
 * 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 <sys/proc.h>
#include <sys/kernel.h>
#include <sys/device.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>

#include <uvm/uvm_extern.h>

#include <sh/cache.h>

#include <machine/autoconf.h>
#define _LANDISK_BUS_DMA_PRIVATE
#include <machine/bus.h>

#if defined(DEBUG) && defined(BUSDMA_DEBUG)
#define DPRINTF(a)      printf a
#else
#define DPRINTF(a)
#endif

struct _bus_dma_tag landisk_bus_dma = {
        ._cookie = NULL,

        ._dmamap_create = _bus_dmamap_create,
        ._dmamap_destroy = _bus_dmamap_destroy,
        ._dmamap_load = _bus_dmamap_load,
        ._dmamap_load_mbuf = _bus_dmamap_load_mbuf,
        ._dmamap_load_uio = _bus_dmamap_load_uio,
        ._dmamap_load_raw = _bus_dmamap_load_raw,
        ._dmamap_unload = _bus_dmamap_unload,
        ._dmamap_sync = _bus_dmamap_sync,

        ._dmamem_alloc = _bus_dmamem_alloc,
        ._dmamem_free = _bus_dmamem_free,
        ._dmamem_map = _bus_dmamem_map,
        ._dmamem_unmap = _bus_dmamem_unmap,
        ._dmamem_mmap = _bus_dmamem_mmap,
};

#define DMAMAP_RESET(_m) do { \
        (_m)->dm_mapsize = 0; \
        (_m)->dm_nsegs = 0; \
} while (0)

int     _bus_dmamap_load_vaddr(bus_dma_tag_t, bus_dmamap_t,
            void *, bus_size_t, pmap_t);
int     _bus_dmamap_load_paddr(bus_dma_tag_t, bus_dmamap_t,
            paddr_t, vaddr_t, bus_size_t);

/*
 * Create a DMA map.
 */
int
_bus_dmamap_create(bus_dma_tag_t t, bus_size_t size, int nsegments,
    bus_size_t maxsegsz, bus_size_t boundary, int flags, bus_dmamap_t *dmamp)
{
        bus_dmamap_t map;
        void *mapstore;
        size_t mapsize;
        int error;

        DPRINTF(("bus_dmamap_create: t = %p, size = %ld, nsegments = %d, maxsegsz = %ld, boundary = %ld, flags = %x\n", t, size, nsegments, maxsegsz, boundary, flags));

        /*
         * Allocate and initialize the DMA map.  The end of the map
         * is a variable-sized array of segments, so we allocate enough
         * room for them in one shot.
         *
         * Note we don't preserve the WAITOK or NOWAIT flags.  Preservation
         * of ALLOCNOW notifies others that we've reserved these resources,
         * and they are not to be freed.
         *
         * The bus_dmamap_t includes one bus_dma_segment_t, hence
         * the (nsegments - 1).
         */
        error = 0;
        mapsize = sizeof(struct _bus_dmamap) +
            (sizeof(bus_dma_segment_t) * (nsegments - 1));
        if ((mapstore = malloc(mapsize, M_DEVBUF, (flags & BUS_DMA_NOWAIT) ?
            (M_NOWAIT | M_ZERO) : (M_WAITOK | M_ZERO))) == NULL)
                return (ENOMEM);

        DPRINTF(("bus_dmamap_create: dmamp = %p\n", mapstore));

        map = (bus_dmamap_t)mapstore;
        map->_dm_size = size;
        map->_dm_segcnt = nsegments;
        map->_dm_maxsegsz = maxsegsz;
        map->_dm_boundary = boundary;
        map->_dm_flags = flags & ~(BUS_DMA_WAITOK|BUS_DMA_NOWAIT);

        DMAMAP_RESET(map); /* no valid mappings */

        *dmamp = map;

        return (0);
}

/*
 * Destroy a DMA map.
 */
void
_bus_dmamap_destroy(bus_dma_tag_t t, bus_dmamap_t map)
{
        size_t mapsize;

        DPRINTF(("bus_dmamap_destroy: t = %p, map = %p\n", t, map));

        mapsize = sizeof(struct _bus_dmamap) +
            (sizeof(bus_dma_segment_t) * (map->_dm_segcnt - 1));
        free(map, M_DEVBUF, mapsize);
}

int
_bus_dmamap_load_paddr(bus_dma_tag_t t, bus_dmamap_t map,
    paddr_t paddr, vaddr_t vaddr, bus_size_t size)
{
        bus_dma_segment_t * const segs = map->dm_segs;
        bus_addr_t bmask = ~(map->_dm_boundary - 1);

        int first = map->dm_mapsize == 0;
        int nseg = map->dm_nsegs;
        paddr_t lastaddr = SH3_P2SEG_TO_PHYS(segs[nseg].ds_addr);

        map->dm_mapsize += size;

        do {
                bus_size_t sgsize = size;

                /* Make sure we don't cross any boundaries. */
                if (map->_dm_boundary > 0) {
                        bus_addr_t baddr; /* next boundary address */

                        baddr = (paddr + map->_dm_boundary) & bmask;
                        if (sgsize > (baddr - paddr))
                                sgsize = (baddr - paddr);
                }

                /*
                 * Insert chunk into a segment, coalescing with
                 * previous segment if possible.
                 */
                if (first) {
                        /* first segment */
                        segs[nseg].ds_addr = SH3_PHYS_TO_P2SEG(paddr);
                        segs[nseg].ds_len = sgsize;
                        segs[nseg]._ds_vaddr = vaddr;
                        first = 0;
                } else if ((paddr == lastaddr)
                 && (segs[nseg].ds_len + sgsize <= map->_dm_maxsegsz)
                 && (map->_dm_boundary == 0 ||
                     (segs[nseg].ds_addr & bmask) == (paddr & bmask))) {
                        /* coalesce */
                        segs[nseg].ds_len += sgsize;
                } else {
                        if (++nseg >= map->_dm_segcnt)
                                return (EFBIG);

                        /* new segment */
                        segs[nseg].ds_addr = SH3_PHYS_TO_P2SEG(paddr);
                        segs[nseg].ds_len = sgsize;
                        segs[nseg]._ds_vaddr = vaddr;
                }

                lastaddr = paddr + sgsize;
                paddr += sgsize;
                vaddr += sgsize;
                size -= sgsize;
        } while (size > 0);

        map->dm_nsegs = nseg;

        return (0);
}

int
_bus_dmamap_load_vaddr(bus_dma_tag_t t, bus_dmamap_t map,
    void *buf, bus_size_t size, pmap_t pmap)
{
        vaddr_t vaddr;
        paddr_t paddr;
        vaddr_t next, end;
        int error;

        vaddr = (vaddr_t)buf;
        end = vaddr + size;

        if (pmap == pmap_kernel() &&
            vaddr >= SH3_P1SEG_BASE && end <= SH3_P2SEG_END)
                paddr = SH3_P1SEG_TO_PHYS(vaddr);
        else {
                for (next = (vaddr + PAGE_SIZE) & ~PAGE_MASK;
                    next < end; next += PAGE_SIZE) {
                        pmap_extract(pmap, vaddr, &paddr);
                        error = _bus_dmamap_load_paddr(t, map,
                            paddr, vaddr, next - vaddr);
                        if (error != 0)
                                return (error);

                        vaddr = next;
                }

                pmap_extract(pmap, vaddr, &paddr);
                size = end - vaddr;
        }

        return (_bus_dmamap_load_paddr(t, map, paddr, vaddr, size));
}

/*
 * Load a DMA map with a linear buffer.
 */
int
_bus_dmamap_load(bus_dma_tag_t t, bus_dmamap_t map, void *buf,
    bus_size_t buflen, struct proc *p, int flags)
{
        int error;

        DPRINTF(("bus_dmamap_load: t = %p, map = %p, buf = %p, buflen = %ld, p = %p, flags = %x\n", t, map, buf, buflen, p, flags));

        DMAMAP_RESET(map);

        if (buflen > map->_dm_size)
                return (EINVAL);

        error = _bus_dmamap_load_vaddr(t, map, buf, buflen,
            p == NULL ? pmap_kernel() : p->p_vmspace->vm_map.pmap);
        if (error != 0) {
                DMAMAP_RESET(map); /* no valid mappings */
                return (error);
        }

        map->dm_nsegs++;

        return (0);
}

/*
 * Like _bus_dmamap_load(), but for mbufs.
 */
int
_bus_dmamap_load_mbuf(bus_dma_tag_t t, bus_dmamap_t map, struct mbuf *m0,
    int flags)
{
        struct mbuf *m;
        int error;

        DMAMAP_RESET(map);

#ifdef DIAGNOSTIC
        if ((m0->m_flags & M_PKTHDR) == 0)
                panic("_bus_dmamap_load_mbuf: no packet header");
#endif

        if (m0->m_pkthdr.len > map->_dm_size)
                return (EINVAL);

        for (m = m0; m != NULL; m = m->m_next) {
                if (m->m_len == 0)
                        continue;

                error = _bus_dmamap_load_vaddr(t, map, m->m_data, m->m_len,
                    pmap_kernel());
                if (error != 0) {
                        DMAMAP_RESET(map);
                        return (error);
                }
        }

        map->dm_nsegs++;

        return (0);
}

/*
 * Like _bus_dmamap_load(), but for uios.
 */
int
_bus_dmamap_load_uio(bus_dma_tag_t t, bus_dmamap_t map, struct uio *uio,
    int flags)
{

        panic("_bus_dmamap_load_uio: not implemented");
}

/*
 * Like _bus_dmamap_load(), but for raw memory allocated with
 * bus_dmamem_alloc().
 */
int
_bus_dmamap_load_raw(bus_dma_tag_t t, bus_dmamap_t map,
    bus_dma_segment_t *segs, int nsegs, bus_size_t size, int flags)
{

        panic("_bus_dmamap_load_raw: not implemented");
}

/*
 * Unload a DMA map.
 */
void
_bus_dmamap_unload(bus_dma_tag_t t, bus_dmamap_t map)
{

        DPRINTF(("bus_dmamap_unload: t = %p, map = %p\n", t, map));

        map->dm_nsegs = 0;
        map->dm_mapsize = 0;
}

/*
 * Synchronize a DMA map.
 */
void
_bus_dmamap_sync(bus_dma_tag_t t, bus_dmamap_t map, bus_addr_t offset,
    bus_size_t len, int ops)
{
        bus_size_t minlen;
        bus_addr_t addr, naddr;
        int i;

        DPRINTF(("bus_dmamap_sync: t = %p, map = %p, offset = %ld, len = %ld, ops = %x\n", t, map, offset, len, ops));

#ifdef DIAGNOSTIC
        /*
         * Mixing PRE and POST operations is not allowed.
         */
        if ((ops & (BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE)) != 0 &&
            (ops & (BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE)) != 0)
                panic("_bus_dmamap_sync: mix PRE and POST");

        if (offset >= map->dm_mapsize)
                panic("_bus_dmamap_sync: bad offset");
        if ((offset + len) > map->dm_mapsize)
                panic("_bus_dmamap_sync: bad length");
#endif

        if (!sh_cache_enable_dcache) {
                /* Nothing to do */
                DPRINTF(("bus_dmamap_sync: disabled D-Cache\n"));
                return;
        }

        for (i = 0; i < map->dm_nsegs && len != 0; i++) {
                /* Find the beginning segment. */
                if (offset >= map->dm_segs[i].ds_len) {
                        offset -= map->dm_segs[i].ds_len;
                        continue;
                }

                /*
                 * Now at the first segment to sync; nail
                 * each segment until we have exhausted the
                 * length.
                 */
                minlen = len < map->dm_segs[i].ds_len - offset ?
                    len : map->dm_segs[i].ds_len - offset;

                addr = map->dm_segs[i]._ds_vaddr;
                naddr = addr + offset;

                if ((naddr >= SH3_P2SEG_BASE)
                 && (naddr + minlen <= SH3_P2SEG_END)) {
                        DPRINTF(("bus_dmamap_sync: P2SEG (0x%08lx)\n", naddr));
                        offset = 0;
                        len -= minlen;
                        continue;
                }

                DPRINTF(("bus_dmamap_sync: flushing segment %d "
                    "(0x%lx+%lx, 0x%lx+0x%lx) (remain = %ld)\n",
                    i, addr, offset, addr, offset + minlen - 1, len));

                switch (ops) {
                case BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE:
                        if (SH_HAS_WRITEBACK_CACHE)
                                sh_dcache_wbinv_range(naddr, minlen);
                        else
                                sh_dcache_inv_range(naddr, minlen);
                        break;

                case BUS_DMASYNC_PREREAD:
                        if (SH_HAS_WRITEBACK_CACHE &&
                            ((naddr | minlen) & (sh_cache_line_size - 1)) != 0)
                                sh_dcache_wbinv_range(naddr, minlen);
                        else
                                sh_dcache_inv_range(naddr, minlen);
                        break;

                case BUS_DMASYNC_PREWRITE:
                        if (SH_HAS_WRITEBACK_CACHE)
                                sh_dcache_wb_range(naddr, minlen);
                        break;

                case BUS_DMASYNC_POSTREAD:
                case BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE:
                        sh_dcache_inv_range(naddr, minlen);
                        break;
                }
                offset = 0;
                len -= minlen;
        }
}

/*
 * Allocate memory safe for DMA.
 */
int
_bus_dmamem_alloc(bus_dma_tag_t t, bus_size_t size, bus_size_t alignment,
    bus_size_t boundary, bus_dma_segment_t *segs, int nsegs, int *rsegs,
    int flags)
{
        struct pglist mlist;
        paddr_t curaddr, lastaddr;
        struct vm_page *m;
        int curseg, error, plaflag;

        DPRINTF(("bus_dmamem_alloc: t = %p, size = %ld, alignment = %ld, boundary = %ld, segs = %p, nsegs = %d, rsegs = %p, flags = %x\n", t, size, alignment, boundary, segs, nsegs, rsegs, flags));

        /* Always round the size. */
        size = round_page(size);

        /*
         * Allocate the pages from the VM system.
         */
        plaflag = flags & BUS_DMA_NOWAIT ? UVM_PLA_NOWAIT : UVM_PLA_WAITOK;
        if (flags & BUS_DMA_ZERO)
                plaflag |= UVM_PLA_ZERO;

        TAILQ_INIT(&mlist);
        error = uvm_pglistalloc(size, 0, -1, alignment, boundary,
            &mlist, nsegs, plaflag);
        if (error)
                return (error);

        /*
         * Compute the location, size, and number of segments actually
         * returned by the VM code.
         */
        m = mlist.tqh_first;
        curseg = 0;
        lastaddr = segs[curseg].ds_addr = VM_PAGE_TO_PHYS(m);
        segs[curseg].ds_len = PAGE_SIZE;

        DPRINTF(("bus_dmamem_alloc: m = %p, lastaddr = 0x%08lx\n",m,lastaddr));

        while ((m = TAILQ_NEXT(m, pageq)) != NULL) {
                curaddr = VM_PAGE_TO_PHYS(m);
                DPRINTF(("bus_dmamem_alloc: m = %p, curaddr = 0x%08lx, lastaddr = 0x%08lx\n", m, curaddr, lastaddr));
                if (curaddr == (lastaddr + PAGE_SIZE)) {
                        segs[curseg].ds_len += PAGE_SIZE;
                } else {
                        DPRINTF(("bus_dmamem_alloc: new segment\n"));
                        curseg++;
                        segs[curseg].ds_addr = curaddr;
                        segs[curseg].ds_len = PAGE_SIZE;
                }
                lastaddr = curaddr;
        }

        *rsegs = curseg + 1;

        DPRINTF(("bus_dmamem_alloc: curseg = %d, *rsegs = %d\n",curseg,*rsegs));

        return (0);
}

/*
 * Common function for freeing DMA-safe memory.  May be called by
 * bus-specific DMA memory free functions.
 */
void
_bus_dmamem_free(bus_dma_tag_t t, bus_dma_segment_t *segs, int nsegs)
{
        struct vm_page *m;
        bus_addr_t addr;
        struct pglist mlist;
        int curseg;

        DPRINTF(("bus_dmamem_free: t = %p, segs = %p, nsegs = %d\n", t, segs, nsegs));

        /*
         * Build a list of pages to free back to the VM system.
         */
        TAILQ_INIT(&mlist);
        for (curseg = 0; curseg < nsegs; curseg++) {
                DPRINTF(("bus_dmamem_free: segs[%d]: ds_addr = 0x%08lx, ds_len = %ld\n", curseg, segs[curseg].ds_addr, segs[curseg].ds_len));
                for (addr = segs[curseg].ds_addr;
                    addr < (segs[curseg].ds_addr + segs[curseg].ds_len);
                    addr += PAGE_SIZE) {
                        m = PHYS_TO_VM_PAGE(addr);
                        DPRINTF(("bus_dmamem_free: m = %p\n", m));
                        TAILQ_INSERT_TAIL(&mlist, m, pageq);
                }
        }

        uvm_pglistfree(&mlist);
}


int
_bus_dmamem_map(bus_dma_tag_t t, bus_dma_segment_t *segs, int nsegs,
    size_t size, caddr_t *kvap, int flags)
{
        vaddr_t va;
        bus_addr_t addr;
        int curseg;
        const struct kmem_dyn_mode *kd;

        DPRINTF(("bus_dmamem_map: t = %p, segs = %p, nsegs = %d, size = %d, kvap = %p, flags = %x\n", t, segs, nsegs, size, kvap, flags));

        /*
         * If we're only mapping 1 segment, use P2SEG, to avoid
         * TLB thrashing.
         */
        if (nsegs == 1) {
                if (flags & BUS_DMA_COHERENT) {
                        *kvap = (caddr_t)SH3_PHYS_TO_P2SEG(segs[0].ds_addr);
                } else {
                        *kvap = (caddr_t)SH3_PHYS_TO_P1SEG(segs[0].ds_addr);
                }
                DPRINTF(("bus_dmamem_map: addr = 0x%08lx, kva = %p\n", segs[0].ds_addr, *kvap));
                return 0;
        }

        /* Always round the size. */
        size = round_page(size);
        kd = flags & BUS_DMA_NOWAIT ? &kd_trylock : &kd_waitok;
        va = (vaddr_t)km_alloc(size, &kv_any, &kp_none, kd);
        if (va == 0)
                return (ENOMEM);

        *kvap = (caddr_t)va;
        for (curseg = 0; curseg < nsegs; curseg++) {
                DPRINTF(("bus_dmamem_map: segs[%d]: ds_addr = 0x%08lx, ds_len = %ld\n", curseg, segs[curseg].ds_addr, segs[curseg].ds_len));
                for (addr = segs[curseg].ds_addr;
                     addr < segs[curseg].ds_addr + segs[curseg].ds_len;
                     addr += PAGE_SIZE, va += PAGE_SIZE, size -= PAGE_SIZE) {
                        if (size == 0)
                                panic("_bus_dmamem_map: size botch");
                        pmap_kenter_pa(va, addr,
                            PROT_READ | PROT_WRITE);
                }
        }
        pmap_update(pmap_kernel());

        return (0);
}

void
_bus_dmamem_unmap(bus_dma_tag_t t, caddr_t kva, size_t size)
{

        DPRINTF(("bus_dmamem_unmap: t = %p, kva = %p, size = %d\n", t, kva, size));

#ifdef DIAGNOSTIC
        if ((u_long)kva & PAGE_MASK)
                panic("_bus_dmamem_unmap");
#endif

        /*
         * Nothing to do if we mapped it with P[12]SEG.
         */
        if ((kva >= (caddr_t)SH3_P1SEG_BASE)
         && (kva <= (caddr_t)SH3_P2SEG_END)) {
                return;
        }

        size = round_page(size);
        pmap_kremove((vaddr_t)kva, size);
        pmap_update(pmap_kernel());
        km_free(kva, size, &kv_any, &kp_none);
}

paddr_t
_bus_dmamem_mmap(bus_dma_tag_t t, bus_dma_segment_t *segs, int nsegs,
    off_t off, int prot, int flags)
{

        /* Not implemented. */
        return (paddr_t)(-1);
}