/* $NetBSD: irongate_dma.c,v 1.10 2021/07/04 22:42:36 thorpej Exp $ */

/*-
 * Copyright (c) 2000, 2020 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.
 */

/*
 * DMA support for the AMD 751 (``Irongate'') core logic chipset.
 *
 * The AMD 751 is really unlike all of the other Alpha PCI core logic
 * chipsets.  Instead, it looks like a normal PC chipset (not surprising,
 * since it is used for Athlon processors).
 *
 * Because of this, it lacks all of the SGMAP hardware normally present
 * on an Alpha system, and there are no DMA windows.  Instead, a memory
 * bus address is a PCI DMA address, and ISA DMA above 16M has to be
 * bounced (this is not unlike the Jensen, actually).
 */

#include <sys/cdefs.h>                  /* RCS ID & Copyright macro defns */

__KERNEL_RCSID(0, "$NetBSD: irongate_dma.c,v 1.10 2021/07/04 22:42:36 thorpej Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/device.h>

#define _ALPHA_BUS_DMA_PRIVATE
#include <sys/bus.h>

#include <dev/pci/pcireg.h>
#include <dev/pci/pcivar.h>

#include <alpha/pci/irongatereg.h>
#include <alpha/pci/irongatevar.h>

#include <dev/isa/isareg.h>
#include <dev/isa/isavar.h>

#include <machine/alpha.h>

static bus_dma_tag_t irongate_dma_get_tag(bus_dma_tag_t, alpha_bus_t);

void
irongate_page_physload(unsigned long const start_pfn,
    unsigned long const end_pfn)
{
        /*
         * The Irongate does not have SGMAP DMA.  For this reason, we
         * need to protect the first 16MB of RAM from random allocations
         * in order to give ISA DMA a snowball's chance of working.
         */
        alpha_page_physload_sheltered(start_pfn, end_pfn,
            0, alpha_btop(0x1000000));
}

void
irongate_dma_init(struct irongate_config *icp)
{
        bus_dma_tag_t t;

        /*
         * Initialize the DMA tag used for PCI DMA.
         */
        t = &icp->ic_dmat_pci;
        t->_cookie = icp;
        t->_wbase = 0;
        t->_wsize = 0x100000000UL;
        t->_next_window = NULL;
        t->_boundary = 0;
        t->_sgmap = NULL;
        t->_get_tag = irongate_dma_get_tag;
        t->_dmamap_create = _bus_dmamap_create;
        t->_dmamap_destroy = _bus_dmamap_destroy;
        t->_dmamap_load = _bus_dmamap_load_direct;
        t->_dmamap_load_mbuf = _bus_dmamap_load_mbuf_direct;
        t->_dmamap_load_uio = _bus_dmamap_load_uio_direct;
        t->_dmamap_load_raw = _bus_dmamap_load_raw_direct;
        t->_dmamap_unload = _bus_dmamap_unload;
        t->_dmamap_sync = _bus_dmamap_sync;

        t->_dmamem_alloc = _bus_dmamem_alloc;
        t->_dmamem_free = _bus_dmamem_free;
        t->_dmamem_map = _bus_dmamem_map;
        t->_dmamem_unmap = _bus_dmamem_unmap;
        t->_dmamem_mmap = _bus_dmamem_mmap;

        /*
         * Initialize the DMA tag used for ISA DMA.
         */
        t = &icp->ic_dmat_isa;
        t->_cookie = icp;
        t->_wbase = 0;
        t->_wsize = 0x1000000;
        t->_next_window = NULL;
        t->_boundary = 0;
        t->_sgmap = NULL;
        t->_get_tag = irongate_dma_get_tag;
        t->_dmamap_create = isadma_bounce_dmamap_create;
        t->_dmamap_destroy = isadma_bounce_dmamap_destroy;
        t->_dmamap_load = isadma_bounce_dmamap_load;
        t->_dmamap_load_mbuf = isadma_bounce_dmamap_load_mbuf;
        t->_dmamap_load_uio = isadma_bounce_dmamap_load_uio;
        t->_dmamap_load_raw = isadma_bounce_dmamap_load_raw;
        t->_dmamap_unload = isadma_bounce_dmamap_unload;
        t->_dmamap_sync = isadma_bounce_dmamap_sync;

        t->_dmamem_alloc = isadma_bounce_dmamem_alloc;
        t->_dmamem_free = _bus_dmamem_free;
        t->_dmamem_map = _bus_dmamem_map;
        t->_dmamem_unmap = _bus_dmamem_unmap;
        t->_dmamem_mmap = _bus_dmamem_mmap;
}

/*
 * Return the bus dma tag to be used for the specified bus type.
 * INTERNAL USE ONLY!
 */
static bus_dma_tag_t
irongate_dma_get_tag(bus_dma_tag_t t, alpha_bus_t bustype)
{
        struct irongate_config *icp = t->_cookie;

        switch (bustype) {
        case ALPHA_BUS_PCI:
        case ALPHA_BUS_EISA:
                /*
                 * Busses capable of 32-bit DMA get the PCI DMA tag.
                 */
                return (&icp->ic_dmat_pci);

        case ALPHA_BUS_ISA:
                /*
                 * Lame 24-bit busses have to bounce.
                 */
                return (&icp->ic_dmat_isa);

        default:
                panic("irongate_dma_get_tag: shouldn't be here, really...");
        }
}