freebsd-dev/sys/dev/proto/proto_busdma.c
Marcel Moolenaar 4f027abddb DMA support part 1: DMA tag create & destroy
Create a special resource (= device special file) for management
of tags and maps, as well as for mapping memory into the address
space. DMA resources are managed using the PROTO_IOC_BUSDMA ioctl.
Part 1 implements tag creation, derivation and destruction.
2015-06-06 16:09:25 +00:00

168 lines
4.4 KiB
C

/*-
* Copyright (c) 2015 Marcel Moolenaar
* All rights reserved.
*
* 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 AUTHOR ``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 AUTHOR 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>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <machine/bus.h>
#include <machine/bus_dma.h>
#include <machine/resource.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/queue.h>
#include <sys/rman.h>
#include <sys/sbuf.h>
#include <dev/proto/proto.h>
#include <dev/proto/proto_dev.h>
#include <dev/proto/proto_busdma.h>
MALLOC_DEFINE(M_PROTO_BUSDMA, "proto_busdma", "DMA management data");
static int
proto_busdma_tag_create(struct proto_ioc_busdma *ioc,
struct proto_tag **tag_io, bus_dma_tag_t *busdma_tag_io)
{
struct proto_tag *tag;
int error;
error = bus_dma_tag_create(*busdma_tag_io, ioc->u.tag.align,
ioc->u.tag.bndry, ioc->u.tag.maxaddr, BUS_SPACE_MAXADDR,
NULL, NULL, ioc->u.tag.maxsz, ioc->u.tag.nsegs,
ioc->u.tag.maxsegsz, ioc->u.tag.flags, NULL, NULL,
busdma_tag_io);
if (error)
return (error);
tag = malloc(sizeof(*tag), M_PROTO_BUSDMA, M_WAITOK | M_ZERO);
tag->parent = *tag_io;
tag->busdma_tag = *busdma_tag_io;
*tag_io = tag;
return (0);
}
static void
proto_busdma_tag_destroy(struct proto_tag *tag)
{
bus_dma_tag_destroy(tag->busdma_tag);
free(tag, M_PROTO_BUSDMA);
}
static struct proto_tag *
proto_busdma_tag_lookup(struct proto_busdma *busdma, u_long key)
{
struct proto_tag *tag;
LIST_FOREACH(tag, &busdma->tags, link) {
if ((void *)tag == (void *)key)
return (tag);
}
return (NULL);
}
struct proto_busdma *
proto_busdma_attach(struct proto_softc *sc)
{
struct proto_busdma *busdma;
busdma = malloc(sizeof(*busdma), M_PROTO_BUSDMA, M_WAITOK | M_ZERO);
return (busdma);
}
int
proto_busdma_detach(struct proto_softc *sc, struct proto_busdma *busdma)
{
proto_busdma_cleanup(sc, busdma);
free(busdma, M_PROTO_BUSDMA);
return (0);
}
int
proto_busdma_cleanup(struct proto_softc *sc, struct proto_busdma *busdma)
{
struct proto_tag *tag, *tag1;
LIST_FOREACH_SAFE(tag, &busdma->tags, link, tag1) {
LIST_REMOVE(tag, link);
proto_busdma_tag_destroy(tag);
}
return (0);
}
int
proto_busdma_ioctl(struct proto_softc *sc, struct proto_busdma *busdma,
struct proto_ioc_busdma *ioc)
{
struct proto_tag *tag;
bus_dma_tag_t busdma_tag;
int error;
error = 0;
switch (ioc->request) {
case PROTO_IOC_BUSDMA_TAG_CREATE:
busdma_tag = bus_get_dma_tag(sc->sc_dev);
tag = NULL;
error = proto_busdma_tag_create(ioc, &tag, &busdma_tag);
if (error)
break;
LIST_INSERT_HEAD(&busdma->tags, tag, link);
ioc->key = (uintptr_t)(void *)tag;
break;
case PROTO_IOC_BUSDMA_TAG_DERIVE:
tag = proto_busdma_tag_lookup(busdma, ioc->key);
if (tag == NULL) {
error = EINVAL;
break;
}
busdma_tag = tag->busdma_tag;
error = proto_busdma_tag_create(ioc, &tag, &busdma_tag);
if (error)
break;
LIST_INSERT_HEAD(&busdma->tags, tag, link);
ioc->key = (uintptr_t)(void *)tag;
break;
case PROTO_IOC_BUSDMA_TAG_DESTROY:
tag = proto_busdma_tag_lookup(busdma, ioc->key);
if (tag == NULL) {
error = EINVAL;
break;
}
LIST_REMOVE(tag, link);
proto_busdma_tag_destroy(tag);
break;
default:
error = EINVAL;
break;
}
return (error);
}