580 lines
15 KiB
C
580 lines
15 KiB
C
/* $NetBSD: isadma_bounce.c,v 1.9 2009/03/14 14:45:52 dsl Exp $ */
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/*-
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* Copyright (c) 1996, 1997, 1998, 2000 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
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* NASA Ames Research Center.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h> /* RCS ID & Copyright macro defns */
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__KERNEL_RCSID(0, "$NetBSD: isadma_bounce.c,v 1.9 2009/03/14 14:45:52 dsl Exp $");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/syslog.h>
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#include <sys/device.h>
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#include <sys/malloc.h>
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#include <sys/proc.h>
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#include <sys/mbuf.h>
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#define _ALPHA_BUS_DMA_PRIVATE
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#include <machine/bus.h>
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#include <dev/isa/isareg.h>
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#include <dev/isa/isavar.h>
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#include <uvm/uvm_extern.h>
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extern paddr_t avail_end;
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/*
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* Cookie used by bouncing ISA DMA. A pointer to one of these is stashed
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* in the DMA map.
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*/
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struct isadma_bounce_cookie {
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int id_flags; /* flags; see below */
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/*
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* Information about the original buffer used during
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* DMA map syncs. Note that origbuflen is only used
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* for ID_BUFTYPE_LINEAR.
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*/
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void *id_origbuf; /* pointer to orig buffer if
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bouncing */
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bus_size_t id_origbuflen; /* ...and size */
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int id_buftype; /* type of buffer */
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void *id_bouncebuf; /* pointer to the bounce buffer */
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bus_size_t id_bouncebuflen; /* ...and size */
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int id_nbouncesegs; /* number of valid bounce segs */
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bus_dma_segment_t id_bouncesegs[1]; /* array of bounce buffer
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physical memory segments */
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};
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/* id_flags */
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#define ID_MIGHT_NEED_BOUNCE 0x01 /* map could need bounce buffers */
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#define ID_HAS_BOUNCE 0x02 /* map currently has bounce buffers */
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#define ID_IS_BOUNCING 0x04 /* map is bouncing current xfer */
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/* id_buftype */
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#define ID_BUFTYPE_INVALID 0
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#define ID_BUFTYPE_LINEAR 1
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#define ID_BUFTYPE_MBUF 2
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#define ID_BUFTYPE_UIO 3
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#define ID_BUFTYPE_RAW 4
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int isadma_bounce_alloc_bouncebuf(bus_dma_tag_t, bus_dmamap_t,
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bus_size_t, int);
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void isadma_bounce_free_bouncebuf(bus_dma_tag_t, bus_dmamap_t);
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/*
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* Create an ISA DMA map.
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*/
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int
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isadma_bounce_dmamap_create(bus_dma_tag_t t, bus_size_t size, int nsegments,
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bus_size_t maxsegsz, bus_size_t boundary, int flags, bus_dmamap_t *dmamp)
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{
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struct isadma_bounce_cookie *cookie;
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bus_dmamap_t map;
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int error, cookieflags;
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void *cookiestore;
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size_t cookiesize;
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/* Call common function to create the basic map. */
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error = _bus_dmamap_create(t, size, nsegments, maxsegsz, boundary,
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flags, dmamp);
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if (error)
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return (error);
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map = *dmamp;
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map->_dm_cookie = NULL;
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cookiesize = sizeof(*cookie);
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/*
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* ISA only has 24-bits of address space. This means
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* we can't DMA to pages over 16M. In order to DMA to
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* arbitrary buffers, we use "bounce buffers" - pages
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* in memory below the 16M boundary. On DMA reads,
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* DMA happens to the bounce buffers, and is copied into
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* the caller's buffer. On writes, data is copied into
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* but bounce buffer, and the DMA happens from those
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* pages. To software using the DMA mapping interface,
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* this looks simply like a data cache.
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*
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* If we have more than 16M of RAM in the system, we may
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* need bounce buffers. We check and remember that here.
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*
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* ...or, there is an opposite case. The most segments
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* a transfer will require is (maxxfer / PAGE_SIZE) + 1. If
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* the caller can't handle that many segments (e.g. the
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* ISA DMA controller), we may have to bounce it as well.
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*/
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cookieflags = 0;
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if (avail_end > (t->_wbase + t->_wsize) ||
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((map->_dm_size / PAGE_SIZE) + 1) > map->_dm_segcnt) {
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cookieflags |= ID_MIGHT_NEED_BOUNCE;
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cookiesize += (sizeof(bus_dma_segment_t) *
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(map->_dm_segcnt - 1));
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}
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/*
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* Allocate our cookie.
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*/
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if ((cookiestore = malloc(cookiesize, M_DMAMAP,
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(flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK)) == NULL) {
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error = ENOMEM;
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goto out;
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}
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memset(cookiestore, 0, cookiesize);
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cookie = (struct isadma_bounce_cookie *)cookiestore;
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cookie->id_flags = cookieflags;
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map->_dm_cookie = cookie;
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if (cookieflags & ID_MIGHT_NEED_BOUNCE) {
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/*
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* Allocate the bounce pages now if the caller
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* wishes us to do so.
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*/
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if ((flags & BUS_DMA_ALLOCNOW) == 0)
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goto out;
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error = isadma_bounce_alloc_bouncebuf(t, map, size, flags);
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}
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out:
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if (error) {
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if (map->_dm_cookie != NULL)
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free(map->_dm_cookie, M_DMAMAP);
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_bus_dmamap_destroy(t, map);
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}
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return (error);
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}
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/*
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* Destroy an ISA DMA map.
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*/
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void
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isadma_bounce_dmamap_destroy(bus_dma_tag_t t, bus_dmamap_t map)
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{
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struct isadma_bounce_cookie *cookie = map->_dm_cookie;
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/*
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* Free any bounce pages this map might hold.
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*/
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if (cookie->id_flags & ID_HAS_BOUNCE)
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isadma_bounce_free_bouncebuf(t, map);
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free(cookie, M_DMAMAP);
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_bus_dmamap_destroy(t, map);
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}
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/*
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* Load an ISA DMA map with a linear buffer.
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*/
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int
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isadma_bounce_dmamap_load(bus_dma_tag_t t, bus_dmamap_t map, void *buf,
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size_t buflen, struct proc *p, int flags)
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{
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struct isadma_bounce_cookie *cookie = map->_dm_cookie;
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int error;
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/*
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* Make sure that on error condition we return "no valid mappings."
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*/
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map->dm_mapsize = 0;
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map->dm_nsegs = 0;
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/*
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* Try to load the map the normal way. If this errors out,
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* and we can bounce, we will.
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*/
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error = _bus_dmamap_load_direct(t, map, buf, buflen, p, flags);
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if (error == 0 ||
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(error != 0 && (cookie->id_flags & ID_MIGHT_NEED_BOUNCE) == 0))
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return (error);
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/*
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* First attempt failed; bounce it.
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*/
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/*
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* Allocate bounce pages, if necessary.
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*/
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if ((cookie->id_flags & ID_HAS_BOUNCE) == 0) {
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error = isadma_bounce_alloc_bouncebuf(t, map, buflen, flags);
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if (error)
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return (error);
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}
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/*
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* Cache a pointer to the caller's buffer and load the DMA map
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* with the bounce buffer.
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*/
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cookie->id_origbuf = buf;
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cookie->id_origbuflen = buflen;
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cookie->id_buftype = ID_BUFTYPE_LINEAR;
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error = _bus_dmamap_load_direct(t, map, cookie->id_bouncebuf, buflen,
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p, flags);
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if (error) {
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/*
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* Free the bounce pages, unless our resources
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* are reserved for our exclusive use.
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*/
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if ((map->_dm_flags & BUS_DMA_ALLOCNOW) == 0)
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isadma_bounce_free_bouncebuf(t, map);
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return (error);
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}
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/* ...so isadma_bounce_dmamap_sync() knows we're bouncing */
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cookie->id_flags |= ID_IS_BOUNCING;
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map->_dm_window = t;
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return (0);
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}
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/*
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* Like isadma_bounce_dmamap_load(), but for mbufs.
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*/
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int
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isadma_bounce_dmamap_load_mbuf(bus_dma_tag_t t, bus_dmamap_t map,
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struct mbuf *m0, int flags)
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{
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struct isadma_bounce_cookie *cookie = map->_dm_cookie;
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int error;
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/*
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* Make sure on error condition we return "no valid mappings."
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*/
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map->dm_mapsize = 0;
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map->dm_nsegs = 0;
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#ifdef DIAGNOSTIC
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if ((m0->m_flags & M_PKTHDR) == 0)
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panic("isadma_bounce_dmamap_load_mbuf: no packet header");
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#endif
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if (m0->m_pkthdr.len > map->_dm_size)
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return (EINVAL);
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/*
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* Try to load the map the normal way. If this errors out,
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* and we can bounce, we will.
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*/
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error = _bus_dmamap_load_mbuf_direct(t, map, m0, flags);
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if (error == 0 ||
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(error != 0 && (cookie->id_flags & ID_MIGHT_NEED_BOUNCE) == 0))
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return (error);
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/*
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* First attempt failed; bounce it.
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*/
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/*
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* Allocate bounce pages, if necessary.
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*/
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if ((cookie->id_flags & ID_HAS_BOUNCE) == 0) {
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error = isadma_bounce_alloc_bouncebuf(t, map, m0->m_pkthdr.len,
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flags);
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if (error)
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return (error);
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}
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/*
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* Cache a pointer to the caller's buffer and load the DMA map
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* with the bounce buffer.
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*/
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cookie->id_origbuf = m0;
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cookie->id_origbuflen = m0->m_pkthdr.len; /* not really used */
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cookie->id_buftype = ID_BUFTYPE_MBUF;
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error = _bus_dmamap_load_direct(t, map, cookie->id_bouncebuf,
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m0->m_pkthdr.len, NULL, flags);
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if (error) {
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/*
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* Free the bounce pages, unless our resources
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* are reserved for our exclusive use.
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*/
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if ((map->_dm_flags & BUS_DMA_ALLOCNOW) == 0)
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isadma_bounce_free_bouncebuf(t, map);
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return (error);
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}
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/* ...so isadma_bounce_dmamap_sync() knows we're bouncing */
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cookie->id_flags |= ID_IS_BOUNCING;
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map->_dm_window = t;
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return (0);
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}
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/*
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* Like isadma_bounce_dmamap_load(), but for uios.
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*/
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int
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isadma_bounce_dmamap_load_uio(bus_dma_tag_t t, bus_dmamap_t map,
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struct uio *uio, int flags)
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{
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panic("isadma_bounce_dmamap_load_uio: not implemented");
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}
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/*
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* Like isadma_bounce_dmamap_load(), but for raw memory allocated with
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* bus_dmamem_alloc().
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*/
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int
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isadma_bounce_dmamap_load_raw(bus_dma_tag_t t, bus_dmamap_t map,
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bus_dma_segment_t *segs, int nsegs, bus_size_t size, int flags)
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{
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panic("isadma_bounce_dmamap_load_raw: not implemented");
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}
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/*
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* Unload an ISA DMA map.
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*/
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void
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isadma_bounce_dmamap_unload(bus_dma_tag_t t, bus_dmamap_t map)
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{
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struct isadma_bounce_cookie *cookie = map->_dm_cookie;
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/*
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* If we have bounce pages, free them, unless they're
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* reserved for our exclusive use.
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*/
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if ((cookie->id_flags & ID_HAS_BOUNCE) &&
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(map->_dm_flags & BUS_DMA_ALLOCNOW) == 0)
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isadma_bounce_free_bouncebuf(t, map);
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cookie->id_flags &= ~ID_IS_BOUNCING;
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cookie->id_buftype = ID_BUFTYPE_INVALID;
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/*
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* Do the generic bits of the unload.
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*/
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_bus_dmamap_unload(t, map);
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}
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/*
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* Synchronize an ISA DMA map.
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*/
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void
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isadma_bounce_dmamap_sync(bus_dma_tag_t t, bus_dmamap_t map, bus_addr_t offset,
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bus_size_t len, int ops)
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{
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struct isadma_bounce_cookie *cookie = map->_dm_cookie;
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/*
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* Mixing PRE and POST operations is not allowed.
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*/
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if ((ops & (BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE)) != 0 &&
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(ops & (BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE)) != 0)
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panic("isadma_bounce_dmamap_sync: mix PRE and POST");
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#ifdef DIAGNOSTIC
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if ((ops & (BUS_DMASYNC_PREWRITE|BUS_DMASYNC_POSTREAD)) != 0) {
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if (offset >= map->dm_mapsize)
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panic("isadma_bounce_dmamap_sync: bad offset");
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if (len == 0 || (offset + len) > map->dm_mapsize)
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panic("isadma_bounce_dmamap_sync: bad length");
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}
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#endif
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/*
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* If we're not bouncing, just drain the write buffer
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* and return.
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*/
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if ((cookie->id_flags & ID_IS_BOUNCING) == 0) {
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alpha_mb();
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return;
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}
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switch (cookie->id_buftype) {
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case ID_BUFTYPE_LINEAR:
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/*
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* Nothing to do for pre-read.
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*/
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if (ops & BUS_DMASYNC_PREWRITE) {
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/*
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* Copy the caller's buffer to the bounce buffer.
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*/
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memcpy((char *)cookie->id_bouncebuf + offset,
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(char *)cookie->id_origbuf + offset, len);
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}
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if (ops & BUS_DMASYNC_POSTREAD) {
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/*
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* Copy the bounce buffer to the caller's buffer.
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*/
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memcpy((char *)cookie->id_origbuf + offset,
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(char *)cookie->id_bouncebuf + offset, len);
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}
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/*
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* Nothing to do for post-write.
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*/
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break;
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case ID_BUFTYPE_MBUF:
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{
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struct mbuf *m, *m0 = cookie->id_origbuf;
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bus_size_t minlen, moff;
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/*
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* Nothing to do for pre-read.
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*/
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if (ops & BUS_DMASYNC_PREWRITE) {
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/*
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* Copy the caller's buffer to the bounce buffer.
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*/
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m_copydata(m0, offset, len,
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(char *)cookie->id_bouncebuf + offset);
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}
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if (ops & BUS_DMASYNC_POSTREAD) {
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/*
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* Copy the bounce buffer to the caller's buffer.
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*/
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for (moff = offset, m = m0; m != NULL && len != 0;
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m = m->m_next) {
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/* Find the beginning mbuf. */
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if (moff >= m->m_len) {
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moff -= m->m_len;
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continue;
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}
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/*
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* Now at the first mbuf to sync; nail
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* each one until we have exhausted the
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* length.
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*/
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minlen = len < m->m_len - moff ?
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len : m->m_len - moff;
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memcpy(mtod(m, char *) + moff,
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(char *)cookie->id_bouncebuf + offset,
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minlen);
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moff = 0;
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len -= minlen;
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offset += minlen;
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}
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}
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/*
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* Nothing to do for post-write.
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*/
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break;
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}
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case ID_BUFTYPE_UIO:
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panic("isadma_bounce_dmamap_sync: ID_BUFTYPE_UIO");
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break;
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case ID_BUFTYPE_RAW:
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panic("isadma_bounce_dmamap_sync: ID_BUFTYPE_RAW");
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break;
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case ID_BUFTYPE_INVALID:
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panic("isadma_bounce_dmamap_sync: ID_BUFTYPE_INVALID");
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break;
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default:
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printf("unknown buffer type %d\n", cookie->id_buftype);
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panic("isadma_bounce_dmamap_sync");
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}
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/* Drain the write buffer. */
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alpha_mb();
|
|
}
|
|
|
|
/*
|
|
* Allocate memory safe for ISA DMA.
|
|
*/
|
|
int
|
|
isadma_bounce_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)
|
|
{
|
|
paddr_t high;
|
|
|
|
if (avail_end > ISA_DMA_BOUNCE_THRESHOLD)
|
|
high = trunc_page(ISA_DMA_BOUNCE_THRESHOLD);
|
|
else
|
|
high = trunc_page(avail_end);
|
|
|
|
return (_bus_dmamem_alloc_range(t, size, alignment, boundary,
|
|
segs, nsegs, rsegs, flags, 0, high));
|
|
}
|
|
|
|
/**********************************************************************
|
|
* ISA DMA utility functions
|
|
**********************************************************************/
|
|
|
|
int
|
|
isadma_bounce_alloc_bouncebuf(bus_dma_tag_t t, bus_dmamap_t map,
|
|
bus_size_t size, int flags)
|
|
{
|
|
struct isadma_bounce_cookie *cookie = map->_dm_cookie;
|
|
int error = 0;
|
|
|
|
cookie->id_bouncebuflen = round_page(size);
|
|
error = isadma_bounce_dmamem_alloc(t, cookie->id_bouncebuflen,
|
|
PAGE_SIZE, map->_dm_boundary, cookie->id_bouncesegs,
|
|
map->_dm_segcnt, &cookie->id_nbouncesegs, flags);
|
|
if (error)
|
|
goto out;
|
|
error = _bus_dmamem_map(t, cookie->id_bouncesegs,
|
|
cookie->id_nbouncesegs, cookie->id_bouncebuflen,
|
|
(void **)&cookie->id_bouncebuf, flags);
|
|
|
|
out:
|
|
if (error) {
|
|
_bus_dmamem_free(t, cookie->id_bouncesegs,
|
|
cookie->id_nbouncesegs);
|
|
cookie->id_bouncebuflen = 0;
|
|
cookie->id_nbouncesegs = 0;
|
|
} else
|
|
cookie->id_flags |= ID_HAS_BOUNCE;
|
|
|
|
return (error);
|
|
}
|
|
|
|
void
|
|
isadma_bounce_free_bouncebuf(bus_dma_tag_t t, bus_dmamap_t map)
|
|
{
|
|
struct isadma_bounce_cookie *cookie = map->_dm_cookie;
|
|
|
|
_bus_dmamem_unmap(t, cookie->id_bouncebuf,
|
|
cookie->id_bouncebuflen);
|
|
_bus_dmamem_free(t, cookie->id_bouncesegs,
|
|
cookie->id_nbouncesegs);
|
|
cookie->id_bouncebuflen = 0;
|
|
cookie->id_nbouncesegs = 0;
|
|
cookie->id_flags &= ~ID_HAS_BOUNCE;
|
|
}
|