/* $NetBSD: isadma_machdep.c,v 1.14 2022/01/22 15:10:32 skrll Exp $ */
/*-
* Copyright (c) 1996, 1997, 1998 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>
__KERNEL_RCSID(0, "$NetBSD: isadma_machdep.c,v 1.14 2022/01/22 15:10:32 skrll Exp $");
#define ISA_DMA_STATS
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/syslog.h>
#include <sys/device.h>
#include <sys/kmem.h>
#include <sys/proc.h>
#include <sys/mbuf.h>
#define _POWERPC_BUS_DMA_PRIVATE
#include <sys/bus.h>
#include <machine/pio.h>
#include <dev/isa/isareg.h>
#include <dev/isa/isavar.h>
#include <uvm/uvm.h>
/*
* Cookie used by ISA dma. A pointer to one of these it stashed in
* the DMA map.
*/
struct powerpc_isa_dma_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[0]; /* 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 */
/* id_buftype */
#define ID_BUFTYPE_INVALID 0
#define ID_BUFTYPE_LINEAR 1
#define ID_BUFTYPE_MBUF 2
#define ID_BUFTYPE_UIO 3
#define ID_BUFTYPE_RAW 4
static int _isa_bus_dmamap_create(bus_dma_tag_t, bus_size_t, int,
bus_size_t, bus_size_t, int, bus_dmamap_t *);
static void _isa_bus_dmamap_destroy(bus_dma_tag_t, bus_dmamap_t);
static int _isa_bus_dmamap_load(bus_dma_tag_t, bus_dmamap_t, void *,
bus_size_t, struct proc *, int);
static int _isa_bus_dmamap_load_mbuf(bus_dma_tag_t, bus_dmamap_t,
struct mbuf *, int);
static int _isa_bus_dmamap_load_uio(bus_dma_tag_t, bus_dmamap_t,
struct uio *, int);
static int _isa_bus_dmamap_load_raw(bus_dma_tag_t, bus_dmamap_t,
bus_dma_segment_t *, int, bus_size_t, int);
static void _isa_bus_dmamap_unload(bus_dma_tag_t, bus_dmamap_t);
static void _isa_bus_dmamap_sync(bus_dma_tag_t, bus_dmamap_t,
bus_addr_t, bus_size_t, int);
static int _isa_bus_dmamem_alloc(bus_dma_tag_t, bus_size_t, bus_size_t,
bus_size_t, bus_dma_segment_t *, int, int *, int);
static int _isa_dma_alloc_bouncebuf(bus_dma_tag_t, bus_dmamap_t,
bus_size_t, int);
static void _isa_dma_free_bouncebuf(bus_dma_tag_t, bus_dmamap_t);
/*
* Entry points for ISA DMA. These are mostly wrappers around
* the generic functions that understand how to deal with bounce
* buffers, if necessary.
*/
struct powerpc_bus_dma_tag isa_bus_dma_tag = {
ISA_DMA_BOUNCE_THRESHOLD,
_isa_bus_dmamap_create,
_isa_bus_dmamap_destroy,
_isa_bus_dmamap_load,
_isa_bus_dmamap_load_mbuf,
_isa_bus_dmamap_load_uio,
_isa_bus_dmamap_load_raw,
_isa_bus_dmamap_unload,
_isa_bus_dmamap_sync,
_isa_bus_dmamem_alloc,
_bus_dmamem_free,
_bus_dmamem_map,
_bus_dmamem_unmap,
_bus_dmamem_mmap,
};
/**********************************************************************
* bus.h dma interface entry points
**********************************************************************/
#ifdef ISA_DMA_STATS
#define STAT_INCR(v) (v)++
#define STAT_DECR(v) do { \
if ((v) == 0) \
printf("%s:%d -- Already 0!\n", __FILE__, __LINE__); \
else \
(v)--; \
} while (0)
u_long isa_dma_stats_loads;
u_long isa_dma_stats_bounces;
u_long isa_dma_stats_nbouncebufs;
#else
#define STAT_INCR(v)
#define STAT_DECR(v)
#endif
/*
* Create an ISA DMA map.
*/
int
_isa_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 powerpc_isa_dma_cookie *cookie;
bus_dmamap_t map;
int error, cookieflags, bank;
void *cookiestore;
size_t cookiesize;
paddr_t avail_end = 0;
for (bank = uvm_physseg_get_first();
uvm_physseg_valid_p(bank);
bank = uvm_physseg_get_next(bank)) {
if (avail_end < uvm_physseg_get_avail_end(bank) << PGSHIFT)
avail_end = uvm_physseg_get_avail_end(bank) << PGSHIFT;
}
/* Call common function to create the basic map. */
error = _bus_dmamap_create(t, size, nsegments, maxsegsz, boundary,
flags, dmamp);
if (error)
return (error);
map = *dmamp;
map->_dm_cookie = NULL;
cookiesize = sizeof(*cookie);
/*
* 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.
*
* There are exceptions, however. VLB devices can do
* 32-bit DMA, and indicate 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 (avail_end <= t->_bounce_thresh ||
(flags & ISABUS_DMA_32BIT) != 0) {
/* Bouncing not necessary due to memory size. */
map->_dm_bounce_thresh = 0;
}
cookieflags = 0;
if (map->_dm_bounce_thresh != 0 ||
((map->_dm_size / PAGE_SIZE) + 1) > map->_dm_segcnt) {
cookieflags |= ID_MIGHT_NEED_BOUNCE;
cookiesize += (sizeof(bus_dma_segment_t) * map->_dm_segcnt);
}
/*
* Allocate our cookie.
*/
if ((cookiestore = kmem_intr_alloc(cookiesize,
(flags & BUS_DMA_NOWAIT) ? KM_NOSLEEP : KM_SLEEP)) == NULL) {
error = ENOMEM;
goto out;
}
memset(cookiestore, 0, cookiesize);
cookie = (struct powerpc_isa_dma_cookie *)cookiestore;
cookie->id_flags = cookieflags;
map->_dm_cookie = cookie;
if (cookieflags & ID_MIGHT_NEED_BOUNCE) {
/*
* Allocate the bounce pages now if the caller
* wishes us to do so.
*/
if ((flags & BUS_DMA_ALLOCNOW) == 0)
goto out;
error = _isa_dma_alloc_bouncebuf(t, map, size, flags);
}
out:
if (error) {
if (map->_dm_cookie != NULL)
kmem_intr_free(cookiestore, cookiesize);
_bus_dmamap_destroy(t, map);
}
return (error);
}
/*
* Destroy an ISA DMA map.
*/
void
_isa_bus_dmamap_destroy(bus_dma_tag_t t, bus_dmamap_t map)
{
struct powerpc_isa_dma_cookie *cookie = map->_dm_cookie;
/*
* Free any bounce pages this map might hold.
*/
if (cookie->id_flags & ID_HAS_BOUNCE)
_isa_dma_free_bouncebuf(t, map);
size_t cookiesize = sizeof(*cookie);
if (cookie->id_flags & ID_MIGHT_NEED_BOUNCE)
cookiesize += (sizeof(bus_dma_segment_t) * map->_dm_segcnt);
kmem_intr_free(cookie, cookiesize);
_bus_dmamap_destroy(t, map);
}
/*
* Load an ISA DMA map with a linear buffer.
*/
int
_isa_bus_dmamap_load(bus_dma_tag_t t, bus_dmamap_t map, void *buf,
bus_size_t buflen, struct proc *p, int flags)
{
struct powerpc_isa_dma_cookie *cookie = map->_dm_cookie;
int error;
STAT_INCR(isa_dma_stats_loads);
/*
* 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(t, map, buf, buflen, p, flags);
if (error == 0 || (cookie->id_flags & ID_MIGHT_NEED_BOUNCE) == 0)
return (error);
/*
* First attempt failed; bounce it.
*/
STAT_INCR(isa_dma_stats_bounces);
/*
* Allocate bounce pages, if necessary.
*/
if ((cookie->id_flags & ID_HAS_BOUNCE) == 0) {
error = _isa_dma_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(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)
_isa_dma_free_bouncebuf(t, map);
return (error);
}
/* ...so _isa_bus_dmamap_sync() knows we're bouncing */
cookie->id_flags |= ID_IS_BOUNCING;
return (0);
}
/*
* Like _isa_bus_dmamap_load(), but for mbufs.
*/
int
_isa_bus_dmamap_load_mbuf(bus_dma_tag_t t, bus_dmamap_t map, struct mbuf *m0,
int flags)
{
struct powerpc_isa_dma_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;
#ifdef DIAGNOSTIC
if ((m0->m_flags & M_PKTHDR) == 0)
panic("_isa_bus_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(t, map, m0, flags);
if (error == 0 || (cookie->id_flags & ID_MIGHT_NEED_BOUNCE) == 0)
return (error);
/*
* First attempt failed; bounce it.
*/
STAT_INCR(isa_dma_stats_bounces);
/*
* Allocate bounce pages, if necessary.
*/
if ((cookie->id_flags & ID_HAS_BOUNCE) == 0) {
error = _isa_dma_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(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)
_isa_dma_free_bouncebuf(t, map);
return (error);
}
/* ...so _isa_bus_dmamap_sync() knows we're bouncing */
cookie->id_flags |= ID_IS_BOUNCING;
return (0);
}
/*
* Like _isa_bus_dmamap_load(), but for uios.
*/
int
_isa_bus_dmamap_load_uio(bus_dma_tag_t t, bus_dmamap_t map,
struct uio *uio, int flags)
{
panic("_isa_bus_dmamap_load_uio: not implemented");
}
/*
* Like _isa_bus_dmamap_load(), but for raw memory allocated with
* bus_dmamem_alloc().
*/
int
_isa_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("_isa_bus_dmamap_load_raw: not implemented");
}
/*
* Unload an ISA DMA map.
*/
void
_isa_bus_dmamap_unload(bus_dma_tag_t t, bus_dmamap_t map)
{
struct powerpc_isa_dma_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)
_isa_dma_free_bouncebuf(t, map);
cookie->id_flags &= ~ID_IS_BOUNCING;
cookie->id_buftype = ID_BUFTYPE_INVALID;
/*
* Do the generic bits of the unload.
*/
_bus_dmamap_unload(t, map);
}
/*
* Synchronize an ISA DMA map.
*/
void
_isa_bus_dmamap_sync(bus_dma_tag_t t, bus_dmamap_t map, bus_addr_t offset,
bus_size_t len, int ops)
{
struct powerpc_isa_dma_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("_isa_bus_dmamap_sync: mix PRE and POST");
#ifdef DIAGNOSTIC
if ((ops & (BUS_DMASYNC_PREWRITE|BUS_DMASYNC_POSTREAD)) != 0) {
if (offset >= map->dm_mapsize)
panic("_isa_bus_dmamap_sync: bad offset");
if (len == 0 || (offset + len) > map->dm_mapsize)
panic("_isa_bus_dmamap_sync: bad length");
}
#endif
/*
* If we're not bouncing, just return; nothing to do.
*/
if ((cookie->id_flags & ID_IS_BOUNCING) == 0)
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);
}
/*
* Nothing to do for post-write.
*/
break;
case ID_BUFTYPE_MBUF:
{
struct mbuf *m, *m0 = cookie->id_origbuf;
bus_size_t minlen, moff;
/*
* Nothing to do for pre-read.
*/
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;
memcpy(mtod(m, char *) + moff,
(char *)cookie->id_bouncebuf + offset,
minlen);
moff = 0;
len -= minlen;
offset += minlen;
}
}
/*
* Nothing to do for post-write.
*/
break;
}
case ID_BUFTYPE_UIO:
panic("_isa_bus_dmamap_sync: ID_BUFTYPE_UIO");
break;
case ID_BUFTYPE_RAW:
panic("_isa_bus_dmamap_sync: ID_BUFTYPE_RAW");
break;
case ID_BUFTYPE_INVALID:
panic("_isa_bus_dmamap_sync: ID_BUFTYPE_INVALID");
break;
default:
printf("unknown buffer type %d\n", cookie->id_buftype);
panic("_isa_bus_dmamap_sync");
}
}
/*
* Allocate memory safe for ISA DMA.
*/
int
_isa_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)
{
paddr_t high, avail_end = 0;
int bank;
for (bank = uvm_physseg_get_first();
uvm_physseg_valid_p(bank);
bank = uvm_physseg_get_next(bank)) {
if (avail_end < uvm_physseg_get_avail_end(bank) << PGSHIFT)
avail_end = uvm_physseg_get_avail_end(bank) << PGSHIFT;
}
if (avail_end > ISA_DMA_BOUNCE_THRESHOLD)
high = ISA_DMA_BOUNCE_THRESHOLD - 1;
else
high = avail_end - 1;
return (_bus_dmamem_alloc_range(t, size, alignment, boundary,
segs, nsegs, rsegs, flags, 0, high));
}
/**********************************************************************
* ISA DMA utility functions
**********************************************************************/
int
_isa_dma_alloc_bouncebuf(bus_dma_tag_t t, bus_dmamap_t map, bus_size_t size,
int flags)
{
struct powerpc_isa_dma_cookie *cookie = map->_dm_cookie;
int error = 0;
cookie->id_bouncebuflen = round_page(size);
error = _isa_bus_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;
STAT_INCR(isa_dma_stats_nbouncebufs);
}
return (error);
}
void
_isa_dma_free_bouncebuf(bus_dma_tag_t t, bus_dmamap_t map)
{
struct powerpc_isa_dma_cookie *cookie = map->_dm_cookie;
STAT_DECR(isa_dma_stats_nbouncebufs);
_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;
}