* Copyright (c) 2001 Wayne Knowles

/* $NetBSD: hpcdma.c,v 1.22 2023/12/13 20:53:14 andvar Exp $ */

/*
* Copyright (c) 2001 Wayne Knowles
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Wayne Knowles
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* 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.
*/

/*
* Support for SCSI DMA provided by the HPC.
*
* Note: We use SCSI0 offsets, etc. here. Since the layout of SCSI0
* and SCSI1 are the same, this is no problem.
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: hpcdma.c,v 1.22 2023/12/13 20:53:14 andvar Exp $");

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

#include <uvm/uvm_extern.h>

#include <sys/bus.h>

#include <sgimips/hpc/hpcvar.h>
#include <sgimips/hpc/hpcreg.h>
#include <sgimips/hpc/hpcdma.h>

/*
* Allocate DMA Chain descriptor list
*/
void
hpcdma_init(struct hpc_attach_args *haa, struct hpc_dma_softc *sc, int ndesc)
{
bus_dma_segment_t seg;
int rseg, allocsz;

sc->sc_bst = haa->ha_st;
sc->sc_dmat = haa->ha_dmat;
sc->sc_ndesc = ndesc;
sc->sc_flags = 0;

if (bus_space_subregion(haa->ha_st, haa->ha_sh, haa->ha_dmaoff,
sc->hpc->scsi0_regs_size, &sc->sc_bsh) != 0) {
printf(": can't map DMA registers\n");
return;
}

/* Alloc 1 additional descriptor - needed for DMA bug fix */
allocsz = sizeof(struct hpc_dma_desc) * (ndesc + 1);

/*
* Allocate a block of memory for dma chaining pointers
*/
if (bus_dmamem_alloc(sc->sc_dmat, allocsz, 0, 0, &seg, 1, &rseg,
BUS_DMA_NOWAIT)) {
printf(": can't allocate sglist\n");
return;
}
/* Map pages into kernel memory */
if (bus_dmamem_map(sc->sc_dmat, &seg, rseg, allocsz,
(void **)&sc->sc_desc_kva, BUS_DMA_NOWAIT)) {
printf(": can't map sglist\n");
bus_dmamem_free(sc->sc_dmat, &seg, rseg);
return;
}

if (bus_dmamap_create(sc->sc_dmat, allocsz, 1 /*seg*/, allocsz, 0,
BUS_DMA_WAITOK, &sc->sc_dmamap) != 0) {
printf(": failed to create dmamap\n");
return;
}

if (bus_dmamap_load(sc->sc_dmat, sc->sc_dmamap,
sc->sc_desc_kva, allocsz, NULL, BUS_DMA_NOWAIT)) {
printf(": can't load sglist\n");
return;
}

sc->sc_desc_pa = sc->sc_dmamap->dm_segs[0].ds_addr;
}

void
hpcdma_sglist_create(struct hpc_dma_softc *sc, bus_dmamap_t dmamap)
{
struct hpc_dma_desc *hva;
bus_addr_t hpa;
bus_dma_segment_t *segp;
int i;

KASSERT(dmamap->dm_nsegs <= sc->sc_ndesc);

hva = sc->sc_desc_kva;
hpa = sc->sc_desc_pa;
segp = dmamap->dm_segs;

#ifdef DMA_DEBUG
printf("DMA_SGLIST<");
#endif
for (i = dmamap->dm_nsegs; i; i--) {
#ifdef DMA_DEBUG
printf("%p:%lld, ", (void *)(intptr_t)segp->ds_addr, segp->ds_len);
#endif
hpa += sizeof(struct hpc_dma_desc); /* next chain desc */
if (sc->hpc->revision == 3) {
hva->hpc3_hdd_bufptr = segp->ds_addr;
hva->hpc3_hdd_ctl = segp->ds_len;
hva->hdd_descptr = hpa;
} else /* HPC 1/1.5 */ {
/*
* there doesn't seem to be any good way of doing this
* via an abstraction layer
*/
hva->hpc1_hdd_bufptr = segp->ds_addr;
hva->hpc1_hdd_ctl = segp->ds_len;
hva->hdd_descptr = hpa;
}
++hva;
++segp;
}

/* Work around HPC3 DMA bug */
if (sc->hpc->revision == 3) {
hva->hpc3_hdd_bufptr = 0;
hva->hpc3_hdd_ctl = HPC3_HDD_CTL_EOCHAIN;
hva->hdd_descptr = 0;
} else {
hva--;
hva->hpc1_hdd_bufptr |= HPC1_HDD_CTL_EOCHAIN;
hva->hdd_descptr = 0;
}

#ifdef DMA_DEBUG
printf(">\n");
#endif
bus_dmamap_sync(sc->sc_dmat, sc->sc_dmamap,
0, sizeof(struct hpc_dma_desc) * (dmamap->dm_nsegs + 1),
BUS_DMASYNC_PREWRITE);

/* Load DMA Descriptor list */
bus_space_write_4(sc->sc_bst, sc->sc_bsh, sc->hpc->scsi0_ndbp,
sc->sc_desc_pa);
}

void
hpcdma_cntl(struct hpc_dma_softc *sc, uint32_t mode)
{

bus_space_write_4(sc->sc_bst, sc->sc_bsh, sc->hpc->scsi0_ctl, mode);
}

void
hpcdma_reset(struct hpc_dma_softc *sc)
{

bus_space_write_4(sc->sc_bst, sc->sc_bsh, sc->hpc->scsi0_ctl,
sc->hpc->scsi_dmactl_reset);
delay(100);
bus_space_write_4(sc->sc_bst, sc->sc_bsh, sc->hpc->scsi0_ctl, 0);
delay(1000);
}

void
hpcdma_flush(struct hpc_dma_softc *sc)
{
uint32_t mode;

mode = bus_space_read_4(sc->sc_bst, sc->sc_bsh, sc->hpc->scsi0_ctl);
bus_space_write_4(sc->sc_bst, sc->sc_bsh,
sc->hpc->scsi0_ctl, mode | sc->hpc->scsi_dmactl_flush);

/* Wait for Active bit to drop */
while (bus_space_read_4(sc->sc_bst, sc->sc_bsh, sc->hpc->scsi0_ctl) &
sc->hpc->scsi_dmactl_active) {
bus_space_barrier(sc->sc_bst, sc->sc_bsh, sc->hpc->scsi0_ctl, 4,
BUS_SPACE_BARRIER_READ);
}
}