/*      $NetBSD: bus.c,v 1.39 2024/01/07 07:58:35 isaki Exp $   */

/*-
 * Copyright (c) 1998 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jason R. Thorpe.
 *
 * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

/*
 * bus_space(9) and bus_dma(9) implementation for NetBSD/x68k.
 * These are default implementations; some buses may use their own.
 */

#include "opt_m68k_arch.h"

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: bus.c,v 1.39 2024/01/07 07:58:35 isaki Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/kernel.h>
#include <sys/conf.h>
#include <sys/device.h>
#include <sys/proc.h>

#include <uvm/uvm_extern.h>

#include <m68k/cacheops.h>
#include <machine/bus.h>

#include <dev/bus_dma/bus_dmamem_common.h>

#if defined(M68040) || defined(M68060)
static inline void dmasync_flush(bus_addr_t, bus_size_t);
static inline void dmasync_inval(bus_addr_t, bus_size_t);
#endif

int
x68k_bus_space_alloc(bus_space_tag_t t, bus_addr_t rstart, bus_addr_t rend,
    bus_size_t size, bus_size_t alignment, bus_size_t boundary, int flags,
    bus_addr_t *bpap, bus_space_handle_t *bshp)
{
        return (EINVAL);
}

void
x68k_bus_space_free(bus_space_tag_t t, bus_space_handle_t bsh, bus_size_t size)
{
        panic("bus_space_free: shouldn't be here");
}


extern paddr_t avail_end;

/*
 * Common function for DMA map creation.  May be called by bus-specific
 * DMA map creation functions.
 */
int
x68k_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)
{
        struct x68k_bus_dmamap *map;
        void *mapstore;
        size_t mapsize;

        /*
         * 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).
         */
        mapsize = sizeof(struct x68k_bus_dmamap) +
            (sizeof(bus_dma_segment_t) * (nsegments - 1));
        if ((mapstore = malloc(mapsize, M_DMAMAP,
            (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK)) == NULL)
                return (ENOMEM);

        memset(mapstore, 0, mapsize);
        map = (struct x68k_bus_dmamap *)mapstore;
        map->x68k_dm_size = size;
        map->x68k_dm_segcnt = nsegments;
        map->x68k_dm_maxmaxsegsz = maxsegsz;
        map->x68k_dm_boundary = boundary;
        map->x68k_dm_bounce_thresh = t->_bounce_thresh;
        map->x68k_dm_flags = flags & ~(BUS_DMA_WAITOK|BUS_DMA_NOWAIT);
        map->dm_maxsegsz = maxsegsz;
        map->dm_mapsize = 0;            /* no valid mappings */
        map->dm_nsegs = 0;

        *dmamp = map;
        return (0);
}

/*
 * Common function for DMA map destruction.  May be called by bus-specific
 * DMA map destruction functions.
 */
void
x68k_bus_dmamap_destroy(bus_dma_tag_t t, bus_dmamap_t map)
{

        free(map, M_DMAMAP);
}

/*
 * Common function for loading a DMA map with a linear buffer.  May
 * be called by bus-specific DMA map load functions.
 */
int
x68k_bus_dmamap_load(bus_dma_tag_t t, bus_dmamap_t map, void *buf,
    bus_size_t buflen, struct proc *p, int flags)
{
        paddr_t lastaddr;
        int seg, error;

        /*
         * Make sure that on error condition we return "no valid mappings".
         */
        map->dm_mapsize = 0;
        map->dm_nsegs = 0;
        KASSERT(map->dm_maxsegsz <= map->x68k_dm_maxmaxsegsz);

        if (buflen > map->x68k_dm_size)
                return (EINVAL);

        seg = 0;
        error = x68k_bus_dmamap_load_buffer(map, buf, buflen, p, flags,
            &lastaddr, &seg, 1);
        if (error == 0) {
                map->dm_mapsize = buflen;
                map->dm_nsegs = seg + 1;
        }
        return (error);
}

/*
 * Like x68k_bus_dmamap_load(), but for mbufs.
 */
int
x68k_bus_dmamap_load_mbuf(bus_dma_tag_t t, bus_dmamap_t map, struct mbuf *m0,
    int flags)
{
        paddr_t lastaddr;
        int seg, error, first;
        struct mbuf *m;

        /*
         * Make sure that on error condition we return "no valid mappings."
         */
        map->dm_mapsize = 0;
        map->dm_nsegs = 0;
        KASSERT(map->dm_maxsegsz <= map->x68k_dm_maxmaxsegsz);

#ifdef DIAGNOSTIC
        if ((m0->m_flags & M_PKTHDR) == 0)
                panic("x68k_bus_dmamap_load_mbuf: no packet header");
#endif

        if (m0->m_pkthdr.len > map->x68k_dm_size)
                return (EINVAL);

        first = 1;
        seg = 0;
        error = 0;
        for (m = m0; m != NULL && error == 0; m = m->m_next) {
                if (m->m_len == 0)
                        continue;
                error = x68k_bus_dmamap_load_buffer(map, m->m_data, m->m_len,
                    NULL, flags, &lastaddr, &seg, first);
                first = 0;
        }
        if (error == 0) {
                map->dm_mapsize = m0->m_pkthdr.len;
                map->dm_nsegs = seg + 1;
        }
        return (error);
}

/*
 * Like x68k_bus_dmamap_load(), but for uios.
 */
int
x68k_bus_dmamap_load_uio(bus_dma_tag_t t, bus_dmamap_t map, struct uio *uio,
    int flags)
{
#if 0
        paddr_t lastaddr;
        int seg, i, error, first;
        bus_size_t minlen, resid;
        struct proc *p = NULL;
        struct iovec *iov;
        void *addr;

        /*
         * Make sure that on error condition we return "no valid mappings."
         */
        map->dm_mapsize = 0;
        map->dm_nsegs = 0;
        KASSERT(map->dm_maxsegsz <= map->x68k_dm_maxmaxsegsz);

        resid = uio->uio_resid;
        iov = uio->uio_iov;

        if (uio->uio_segflg == UIO_USERSPACE) {
                p = uio->uio_lwp ? uio->uio_lwp->l_proc : NULL;
#ifdef DIAGNOSTIC
                if (p == NULL)
                        panic("_bus_dmamap_load_uio: USERSPACE but no proc");
#endif
        }

        first = 1;
        seg = 0;
        error = 0;
        for (i = 0; i < uio->uio_iovcnt && resid != 0 && error == 0; i++) {
                /*
                 * Now at the first iovec to load.  Load each iovec
                 * until we have exhausted the residual count.
                 */
                minlen = resid < iov[i].iov_len ? resid : iov[i].iov_len;
                addr = (void *)iov[i].iov_base;

                error = x68k_bus_dmamap_load_buffer(map, addr, minlen,
                    p, flags, &lastaddr, &seg, first);
                first = 0;

                resid -= minlen;
        }
        if (error == 0) {
                map->dm_mapsize = uio->uio_resid;
                map->dm_nsegs = seg + 1;
        }
        return (error);
#else
        panic ("x68k_bus_dmamap_load_uio: not implemented");
#endif
}

/*
 * Like x68k_bus_dmamap_load(), but for raw memory allocated with
 * bus_dmamem_alloc().
 */
int
x68k_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("x68k_bus_dmamap_load_raw: not implemented");
}

/*
 * Common function for unloading a DMA map.  May be called by
 * bus-specific DMA map unload functions.
 */
void
x68k_bus_dmamap_unload(bus_dma_tag_t t, bus_dmamap_t map)
{

        /*
         * No resources to free; just mark the mappings as
         * invalid.
         */
        map->dm_maxsegsz = map->x68k_dm_maxmaxsegsz;
        map->dm_mapsize = 0;
        map->dm_nsegs = 0;
}

#if defined(M68040) || defined(M68060)
static inline void
dmasync_flush(bus_addr_t addr, bus_size_t len)
{
        bus_addr_t end = addr+len;

        if (len <= 1024) {
                addr = addr & ~0xF;

                do {
                        DCFL(addr);
                        addr += 16;
                } while (addr < end);
        } else {
                addr = m68k_trunc_page(addr);

                do {
                        DCFP(addr);
                        addr += PAGE_SIZE;
                } while (addr < end);
        }
}

static inline void
dmasync_inval(bus_addr_t addr, bus_size_t len)
{
        bus_addr_t end = addr+len;

        if (len <= 1024) {
                addr = addr & ~0xF;

                do {
                        DCFL(addr);
                        ICPL(addr);
                        addr += 16;
                } while (addr < end);
        } else {
                addr = m68k_trunc_page(addr);

                do {
                        DCPL(addr);
                        ICPP(addr);
                        addr += PAGE_SIZE;
                } while (addr < end);
        }
}
#endif

/*
 * Common function for DMA map synchronization.  May be called
 * by bus-specific DMA map synchronization functions.
 */
void
x68k_bus_dmamap_sync(bus_dma_tag_t t, bus_dmamap_t map, bus_addr_t offset,
    bus_size_t len, int ops)
{
#if defined(M68040) || defined(M68060)
        bus_dma_segment_t *ds = map->dm_segs;
        bus_addr_t seg;
        int i;

        if ((ops & (BUS_DMASYNC_PREREAD|BUS_DMASYNC_POSTWRITE)) == 0)
                return;
#if defined(M68020) || defined(M68030)
        if (mmutype != MMU_68040) {
                if ((ops & BUS_DMASYNC_POSTWRITE) == 0)
                        return; /* no copyback cache */
                ICIA();         /* no per-page/per-line control */
                DCIA();
                return;
        }
#endif
        if (offset >= map->dm_mapsize)
                return; /* driver bug; warn it? */
        if (offset+len > map->dm_mapsize)
                len = map->dm_mapsize; /* driver bug; warn it? */

        i = 0;
        while (ds[i].ds_len <= offset) {
                offset -= ds[i++].ds_len;
                continue;
        }
        while (len > 0) {
                seg = ds[i].ds_len - offset;
                if (seg > len)
                        seg = len;
                if (mmutype == MMU_68040 && (ops & BUS_DMASYNC_PREWRITE))
                        dmasync_flush(ds[i].ds_addr+offset, seg);
                if (ops & BUS_DMASYNC_POSTREAD)
                        dmasync_inval(ds[i].ds_addr+offset, seg);
                offset = 0;
                len -= seg;
                i++;
        }
#else  /* no 040/060 */
        if ((ops & BUS_DMASYNC_POSTWRITE)) {
                ICIA();         /* no per-page/per-line control */
                DCIA();
        }
#endif
}

/*
 * Common function for DMA-safe memory allocation.  May be called
 * by bus-specific DMA memory allocation functions.
 */
int
x68k_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)
{

        return (x68k_bus_dmamem_alloc_range(t, size, alignment, boundary,
            segs, nsegs, rsegs, flags, 0, trunc_page(avail_end)));
}

/*
 * Common function for freeing DMA-safe memory.  May be called by
 * bus-specific DMA memory free functions.
 */
void
x68k_bus_dmamem_free(bus_dma_tag_t t, bus_dma_segment_t *segs, int nsegs)
{

        _bus_dmamem_free_common(t, segs, nsegs);
}

/*
 * Common function for mapping DMA-safe memory.  May be called by
 * bus-specific DMA memory map functions.
 */
int
x68k_bus_dmamem_map(bus_dma_tag_t t, bus_dma_segment_t *segs, int nsegs,
    size_t size, void **kvap, int flags)
{

        /* XXX BUS_DMA_COHERENT */
        return (_bus_dmamem_map_common(t, segs, nsegs, size, kvap, flags, 0));
}

/*
 * Common function for unmapping DMA-safe memory.  May be called by
 * bus-specific DMA memory unmapping functions.
 */
void
x68k_bus_dmamem_unmap(bus_dma_tag_t t, void *kva, size_t size)
{

        _bus_dmamem_unmap_common(t, kva, size);
}

/*
 * Common function for mmap(2)'ing DMA-safe memory.  May be called by
 * bus-specific DMA mmap(2)'ing functions.
 */
paddr_t
x68k_bus_dmamem_mmap(bus_dma_tag_t t, bus_dma_segment_t *segs, int nsegs,
    off_t off, int prot, int flags)
{
        bus_addr_t rv;

        rv = _bus_dmamem_mmap_common(t, segs, nsegs, off, prot, flags);
        if (rv == (bus_addr_t)-1)
                return (-1);

        return (m68k_btop((char *)rv));
}


/**********************************************************************
 * DMA utility functions
 **********************************************************************/

/*
 * Utility function to load a linear buffer.  lastaddrp holds state
 * between invocations (for multiple-buffer loads).  segp contains
 * the starting segment on entrance, and the ending segment on exit.
 * first indicates if this is the first invocation of this function.
 */
int
x68k_bus_dmamap_load_buffer(bus_dmamap_t map, void *buf, bus_size_t buflen,
     struct proc *p, int flags, paddr_t *lastaddrp, int *segp, int first)
{
        bus_size_t sgsize;
        bus_addr_t curaddr, lastaddr, baddr, bmask;
        vaddr_t vaddr = (vaddr_t)buf;
        int seg;
        pmap_t pmap;

        if (p != NULL)
                pmap = p->p_vmspace->vm_map.pmap;
        else
                pmap = pmap_kernel();

        lastaddr = *lastaddrp;
        bmask  = ~(map->x68k_dm_boundary - 1);

        for (seg = *segp; buflen > 0 ; ) {
                /*
                 * Get the physical address for this segment.
                 */
                (void) pmap_extract(pmap, vaddr, &curaddr);

                /*
                 * If we're beyond the bounce threshold, notify
                 * the caller.
                 */
                if (map->x68k_dm_bounce_thresh != 0 &&
                    curaddr >= map->x68k_dm_bounce_thresh)
                        return (EINVAL);

                /*
                 * Compute the segment size, and adjust counts.
                 */
                sgsize = PAGE_SIZE - m68k_page_offset(vaddr);
                if (buflen < sgsize)
                        sgsize = buflen;

                /*
                 * Make sure we don't cross any boundaries.
                 */
                if (map->x68k_dm_boundary > 0) {
                        baddr = (curaddr + map->x68k_dm_boundary) & bmask;
                        if (sgsize > (baddr - curaddr))
                                sgsize = (baddr - curaddr);
                }

                /*
                 * Insert chunk into a segment, coalescing with
                 * previous segment if possible.
                 */
                if (first) {
                        map->dm_segs[seg].ds_addr = curaddr;
                        map->dm_segs[seg].ds_len = sgsize;
                        first = 0;
                } else {
                        if (curaddr == lastaddr &&
                            (map->dm_segs[seg].ds_len + sgsize) <=
                             map->dm_maxsegsz &&
                            (map->x68k_dm_boundary == 0 ||
                             (map->dm_segs[seg].ds_addr & bmask) ==
                             (curaddr & bmask)))
                                map->dm_segs[seg].ds_len += sgsize;
                        else {
                                if (++seg >= map->x68k_dm_segcnt)
                                        break;
                                map->dm_segs[seg].ds_addr = curaddr;
                                map->dm_segs[seg].ds_len = sgsize;
                        }
                }

                lastaddr = curaddr + sgsize;
                vaddr += sgsize;
                buflen -= sgsize;
        }

        *segp = seg;
        *lastaddrp = lastaddr;

        /*
         * Did we fit?
         */
        if (buflen != 0)
                return (EFBIG);         /* XXX better return value here? */
        return (0);
}

/*
 * Allocate physical memory from the given physical address range.
 * Called by DMA-safe memory allocation methods.
 */
int
x68k_bus_dmamem_alloc_range(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, paddr_t low, paddr_t high)
{

        return (_bus_dmamem_alloc_range_common(t, size, alignment, boundary,
                                               segs, nsegs, rsegs, flags,
                                               low, high));
}