/*-
* Copyright (c) 1996, 1997, 1998, 2000 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
* NASA Ames Research Center.
*
* 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.
*/
#include <sys/cdefs.h> /* RCS ID & Copyright macro defns */
/*
* Cookie used by bouncing ISA DMA. A pointer to one of these is stashed
* in the DMA map.
*/
struct isadma_bounce_cookie {
int id_flags; /* flags; see below */
/*
* Information about the original buffer used during
* DMA map syncs. Note that origbuflen is only used
* for ID_BUFTYPE_LINEAR.
*/
void *id_origbuf; /* pointer to orig buffer if
bouncing */
bus_size_t id_origbuflen; /* ...and size */
int id_buftype; /* type of buffer */
void *id_bouncebuf; /* pointer to the bounce buffer */
bus_size_t id_bouncebuflen; /* ...and size */
int id_nbouncesegs; /* number of valid bounce segs */
bus_dma_segment_t id_bouncesegs[1]; /* array of bounce buffer
physical memory segments */
};
/* id_flags */
#define ID_MIGHT_NEED_BOUNCE 0x01 /* map could need bounce buffers */
#define ID_HAS_BOUNCE 0x02 /* map currently has bounce buffers */
#define ID_IS_BOUNCING 0x04 /* map is bouncing current xfer */
static int isadma_bounce_alloc_bouncebuf(bus_dma_tag_t, bus_dmamap_t,
bus_size_t, int);
static void isadma_bounce_free_bouncebuf(bus_dma_tag_t, bus_dmamap_t);
/*
* Returns true if the system memory configuration exceeds the
* capabilities of ISA DMA.
*/
static bool
isadma_bounce_check_range(bus_dma_tag_t const t)
{
return avail_end > (t->_wbase + t->_wsize);
}
static int
isadma_bounce_cookieflags(bus_dma_tag_t const t, bus_dmamap_t const map)
{
int cookieflags = 0;
/*
* ISA only has 24-bits of address space. This means
* we can't DMA to pages over 16M. In order to DMA to
* arbitrary buffers, we use "bounce buffers" - pages
* in memory below the 16M boundary. On DMA reads,
* DMA happens to the bounce buffers, and is copied into
* the caller's buffer. On writes, data is copied into
* the bounce buffer, and the DMA happens from those
* pages. To software using the DMA mapping interface,
* this looks simply like a data cache.
*
* If we have more than 16M of RAM in the system, we may
* need bounce buffers. We check and remember that here.
*
* ...or, there is an opposite case. The most segments
* a transfer will require is (maxxfer / PAGE_SIZE) + 1. If
* the caller can't handle that many segments (e.g. the
* ISA DMA controller), we may have to bounce it as well.
*/
if (isadma_bounce_check_range(t) ||
((map->_dm_size / PAGE_SIZE) + 1) > map->_dm_segcnt) {
cookieflags |= ID_MIGHT_NEED_BOUNCE;
}
return cookieflags;
}
/*
* Create an ISA DMA map.
*/
int
isadma_bounce_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 isadma_bounce_cookie *cookie;
bus_dmamap_t map;
int error;
/* Call common function to create the basic map. */
error = _bus_dmamap_create(t, size, nsegments, maxsegsz, boundary,
flags, dmamp);
if (error)
return (error);
if (cookie->id_flags & ID_MIGHT_NEED_BOUNCE) {
/*
* Allocate the bounce pages now if the caller
* wishes us to do so.
*/
if (flags & BUS_DMA_ALLOCNOW) {
error = isadma_bounce_alloc_bouncebuf(t, map, size,
flags);
}
}
/*
* Load an ISA DMA map with a linear buffer.
*/
int
isadma_bounce_dmamap_load(bus_dma_tag_t t, bus_dmamap_t map, void *buf,
size_t buflen, struct proc *p, int flags)
{
struct isadma_bounce_cookie *cookie = map->_dm_cookie;
int error;
/*
* Make sure that on error condition we return "no valid mappings."
*/
map->dm_mapsize = 0;
map->dm_nsegs = 0;
/*
* Try to load the map the normal way. If this errors out,
* and we can bounce, we will.
*/
error = _bus_dmamap_load_direct(t, map, buf, buflen, p, flags);
if (error == 0 || (cookie->id_flags & ID_MIGHT_NEED_BOUNCE) == 0)
return (error);
/*
* First attempt failed; bounce it.
*/
/*
* Allocate bounce pages, if necessary.
*/
if ((cookie->id_flags & ID_HAS_BOUNCE) == 0) {
error = isadma_bounce_alloc_bouncebuf(t, map, buflen, flags);
if (error)
return (error);
}
/*
* Cache a pointer to the caller's buffer and load the DMA map
* with the bounce buffer.
*/
cookie->id_origbuf = buf;
cookie->id_origbuflen = buflen;
cookie->id_buftype = ID_BUFTYPE_LINEAR;
error = _bus_dmamap_load_direct(t, map, cookie->id_bouncebuf, buflen,
p, flags);
if (error) {
/*
* Free the bounce pages, unless our resources
* are reserved for our exclusive use.
*/
if ((map->_dm_flags & BUS_DMA_ALLOCNOW) == 0)
isadma_bounce_free_bouncebuf(t, map);
return (error);
}
/*
* Like isadma_bounce_dmamap_load(), but for mbufs.
*/
int
isadma_bounce_dmamap_load_mbuf(bus_dma_tag_t t, bus_dmamap_t map,
struct mbuf *m0, int flags)
{
struct isadma_bounce_cookie *cookie = map->_dm_cookie;
int error;
/*
* Make sure on error condition we return "no valid mappings."
*/
map->dm_mapsize = 0;
map->dm_nsegs = 0;
#ifdef DIAGNOSTIC
if ((m0->m_flags & M_PKTHDR) == 0)
panic("isadma_bounce_dmamap_load_mbuf: no packet header");
#endif
if (m0->m_pkthdr.len > map->_dm_size)
return (EINVAL);
/*
* Try to load the map the normal way. If this errors out,
* and we can bounce, we will.
*/
error = _bus_dmamap_load_mbuf_direct(t, map, m0, flags);
if (error == 0 || (cookie->id_flags & ID_MIGHT_NEED_BOUNCE) == 0)
return (error);
/*
* First attempt failed; bounce it.
*/
/*
* Allocate bounce pages, if necessary.
*/
if ((cookie->id_flags & ID_HAS_BOUNCE) == 0) {
error = isadma_bounce_alloc_bouncebuf(t, map, m0->m_pkthdr.len,
flags);
if (error)
return (error);
}
/*
* Cache a pointer to the caller's buffer and load the DMA map
* with the bounce buffer.
*/
cookie->id_origbuf = m0;
cookie->id_origbuflen = m0->m_pkthdr.len; /* not really used */
cookie->id_buftype = ID_BUFTYPE_MBUF;
error = _bus_dmamap_load_direct(t, map, cookie->id_bouncebuf,
m0->m_pkthdr.len, NULL, flags);
if (error) {
/*
* Free the bounce pages, unless our resources
* are reserved for our exclusive use.
*/
if ((map->_dm_flags & BUS_DMA_ALLOCNOW) == 0)
isadma_bounce_free_bouncebuf(t, map);
return (error);
}
/*
* Like isadma_bounce_dmamap_load(), but for uios.
*/
int
isadma_bounce_dmamap_load_uio(bus_dma_tag_t t, bus_dmamap_t map,
struct uio *uio, int flags)
{
panic("isadma_bounce_dmamap_load_uio: not implemented");
}
/*
* Like isadma_bounce_dmamap_load(), but for raw memory allocated with
* bus_dmamem_alloc().
*/
int
isadma_bounce_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("isadma_bounce_dmamap_load_raw: not implemented");
}
/*
* Unload an ISA DMA map.
*/
void
isadma_bounce_dmamap_unload(bus_dma_tag_t t, bus_dmamap_t map)
{
struct isadma_bounce_cookie *cookie = map->_dm_cookie;
/*
* If we have bounce pages, free them, unless they're
* reserved for our exclusive use.
*/
if ((cookie->id_flags & ID_HAS_BOUNCE) &&
(map->_dm_flags & BUS_DMA_ALLOCNOW) == 0)
isadma_bounce_free_bouncebuf(t, map);
/*
* Do the generic bits of the unload.
*/
_bus_dmamap_unload(t, map);
}
/*
* Synchronize an ISA DMA map.
*/
void
isadma_bounce_dmamap_sync(bus_dma_tag_t t, bus_dmamap_t map, bus_addr_t offset,
bus_size_t len, int ops)
{
struct isadma_bounce_cookie *cookie = map->_dm_cookie;
/*
* 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("isadma_bounce_dmamap_sync: mix PRE and POST");
#ifdef DIAGNOSTIC
if ((ops & (BUS_DMASYNC_PREWRITE|BUS_DMASYNC_POSTREAD)) != 0) {
if (offset >= map->dm_mapsize)
panic("isadma_bounce_dmamap_sync: bad offset");
if (len == 0 || (offset + len) > map->dm_mapsize)
panic("isadma_bounce_dmamap_sync: bad length");
}
#endif
/*
* If we're not bouncing, just drain the write buffer
* and return.
*/
if ((cookie->id_flags & ID_IS_BOUNCING) == 0) {
alpha_mb();
return;
}
switch (cookie->id_buftype) {
case ID_BUFTYPE_LINEAR:
/*
* Nothing to do for pre-read.
*/
if (ops & BUS_DMASYNC_PREWRITE) {
/*
* Copy the caller's buffer to the bounce buffer.
*/
memcpy((char *)cookie->id_bouncebuf + offset,
(char *)cookie->id_origbuf + offset, len);
}
if (ops & BUS_DMASYNC_POSTREAD) {
/*
* Copy the bounce buffer to the caller's buffer.
*/
memcpy((char *)cookie->id_origbuf + offset,
(char *)cookie->id_bouncebuf + offset, len);
}
if (ops & BUS_DMASYNC_PREWRITE) {
/*
* Copy the caller's buffer to the bounce buffer.
*/
m_copydata(m0, offset, len,
(char *)cookie->id_bouncebuf + offset);
}
if (ops & BUS_DMASYNC_POSTREAD) {
/*
* Copy the bounce buffer to the caller's buffer.
*/
for (moff = offset, m = m0; m != NULL && len != 0;
m = m->m_next) {
/* Find the beginning mbuf. */
if (moff >= m->m_len) {
moff -= m->m_len;
continue;
}
/*
* Now at the first mbuf to sync; nail
* each one until we have exhausted the
* length.
*/
minlen = len < m->m_len - moff ?
len : m->m_len - moff;
case ID_BUFTYPE_UIO:
panic("isadma_bounce_dmamap_sync: ID_BUFTYPE_UIO");
break;
case ID_BUFTYPE_RAW:
panic("isadma_bounce_dmamap_sync: ID_BUFTYPE_RAW");
break;
case ID_BUFTYPE_INVALID:
panic("isadma_bounce_dmamap_sync: ID_BUFTYPE_INVALID");
break;
default:
printf("unknown buffer type %d\n", cookie->id_buftype);
panic("isadma_bounce_dmamap_sync");
}
/* Drain the write buffer. */
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 = ISA_DMA_BOUNCE_THRESHOLD - 1;
else
high = avail_end - 1;
