Add DMA memory allocation and freeing.

Slightly rework the tag handling.

Author: marcel

sys/dev/proto/proto_busdma.c

@@ -39,6 +39,8 @@ __FBSDID("$FreeBSD$");
 #include <sys/queue.h>
 #include <sys/rman.h>
 #include <sys/sbuf.h>
+#include <vm/vm.h>
+#include <vm/pmap.h>
 
 #include <dev/proto/proto.h>
 #include <dev/proto/proto_dev.h>
@@ -47,45 +49,139 @@ __FBSDID("$FreeBSD$");
 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)
+proto_busdma_tag_create(struct proto_busdma *busdma, struct proto_tag *parent,
+    struct proto_ioc_busdma *ioc)
 {
 	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);
+	/*
+	 * If nsegs is 1, ignore maxsegsz. What this means is that if we have
+	 * just 1 segment, then maxsz should be equal to maxsegsz. To keep it
+	 * simple for us, limit maxsegsz to maxsz in any case.
+	 */
+	if (ioc->u.tag.maxsegsz > ioc->u.tag.maxsz || ioc->u.tag.nsegs == 1)
+		ioc->u.tag.maxsegsz = ioc->u.tag.maxsz;
+
+	/* A bndry of 0 really means ~0, or no boundary. */
+	if (ioc->u.tag.bndry == 0)
+		ioc->u.tag.bndry = ~0U;
 
 	tag = malloc(sizeof(*tag), M_PROTO_BUSDMA, M_WAITOK | M_ZERO);
-	tag->parent = *tag_io;
-	tag->busdma_tag = *busdma_tag_io;
-	*tag_io = tag;
+	if (parent != NULL) {
+		tag->parent = parent;
+		LIST_INSERT_HEAD(&parent->children, tag, peers);
+		tag->align = MAX(ioc->u.tag.align, parent->align);
+		tag->bndry = MIN(ioc->u.tag.bndry, parent->bndry);
+		tag->maxaddr = MIN(ioc->u.tag.maxaddr, parent->maxaddr);
+		tag->maxsz = MIN(ioc->u.tag.maxsz, parent->maxsz);
+		tag->maxsegsz = MIN(ioc->u.tag.maxsegsz, parent->maxsegsz);
+		tag->nsegs = MIN(ioc->u.tag.nsegs, parent->nsegs);
+		tag->datarate = MIN(ioc->u.tag.datarate, parent->datarate);
+		/* Write constraints back */
+		ioc->u.tag.align = tag->align;
+		ioc->u.tag.bndry = tag->bndry;
+		ioc->u.tag.maxaddr = tag->maxaddr;
+		ioc->u.tag.maxsz = tag->maxsz;
+		ioc->u.tag.maxsegsz = tag->maxsegsz;
+		ioc->u.tag.nsegs = tag->nsegs;
+		ioc->u.tag.datarate = tag->datarate;
+	} else {
+		tag->align = ioc->u.tag.align;
+		tag->bndry = ioc->u.tag.bndry;
+		tag->maxaddr = ioc->u.tag.maxaddr;
+		tag->maxsz = ioc->u.tag.maxsz;
+		tag->maxsegsz = ioc->u.tag.maxsegsz;
+		tag->nsegs = ioc->u.tag.nsegs;
+		tag->datarate = ioc->u.tag.datarate;
+	}
+	LIST_INSERT_HEAD(&busdma->tags, tag, tags);
+	ioc->result = (uintptr_t)(void *)tag;
 	return (0);
 }
 
-static void
-proto_busdma_tag_destroy(struct proto_tag *tag)
+static int
+proto_busdma_tag_destroy(struct proto_busdma *busdma, struct proto_tag *tag)
 {
 
-	bus_dma_tag_destroy(tag->busdma_tag);
+	if (!LIST_EMPTY(&tag->mds))
+		return (EBUSY);
+	if (!LIST_EMPTY(&tag->children))
+		return (EBUSY);
+
+	if (tag->parent != NULL) {
+		LIST_REMOVE(tag, peers);
+		tag->parent = NULL;
+	}
+	LIST_REMOVE(tag, tags);
 	free(tag, M_PROTO_BUSDMA);
+	return (0);
 }
 
 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) {
+	LIST_FOREACH(tag, &busdma->tags, tags) {
 		if ((void *)tag == (void *)key)
 			return (tag);
-        }
-        return (NULL);
+	}
+	return (NULL);
+}
+
+static int
+proto_busdma_mem_alloc(struct proto_busdma *busdma, struct proto_tag *tag,
+    struct proto_ioc_busdma *ioc)
+{
+	struct proto_md *md;
+	int error;
+
+	md = malloc(sizeof(*md), M_PROTO_BUSDMA, M_WAITOK | M_ZERO);
+	md->tag = tag;
+ 
+	error = bus_dma_tag_create(busdma->bd_roottag, tag->align, tag->bndry,
+	    tag->maxaddr, BUS_SPACE_MAXADDR, NULL, NULL, tag->maxsz,
+	    tag->nsegs, tag->maxsegsz, 0, NULL, NULL, &md->bd_tag);
+	if (error) {
+		free(md, M_PROTO_BUSDMA);
+		return (error);
+	}
+	error = bus_dmamem_alloc(md->bd_tag, &md->kva, 0, &md->bd_map);
+	if (error) {
+		bus_dma_tag_destroy(md->bd_tag);
+		free(md, M_PROTO_BUSDMA);
+		return (error);
+	}
+	LIST_INSERT_HEAD(&tag->mds, md, peers);
+	LIST_INSERT_HEAD(&busdma->mds, md, mds);
+	ioc->u.mem.nsegs = 1;
+	ioc->u.mem.physaddr = pmap_kextract((uintptr_t)(md->kva));
+	ioc->result = (uintptr_t)(void *)md;
+	return (0);
+}
+
+static int
+proto_busdma_mem_free(struct proto_busdma *busdma, struct proto_md *md)
+{
+
+	LIST_REMOVE(md, mds);
+	LIST_REMOVE(md, peers);
+	bus_dmamem_free(md->bd_tag, md->kva, md->bd_map);
+	bus_dma_tag_destroy(md->bd_tag);
+	free(md, M_PROTO_BUSDMA);
+	return (0);
+}
+
+static struct proto_md *
+proto_busdma_md_lookup(struct proto_busdma *busdma, u_long key)
+{
+	struct proto_md *md;
+
+	LIST_FOREACH(md, &busdma->mds, mds) {
+		if ((void *)md == (void *)key)
+			return (md);
+	}
+	return (NULL);
 }
 
 struct proto_busdma *
@@ -109,12 +205,13 @@ proto_busdma_detach(struct proto_softc *sc, struct proto_busdma *busdma)
 int
 proto_busdma_cleanup(struct proto_softc *sc, struct proto_busdma *busdma)
 {
+	struct proto_md *md, *md1;
 	struct proto_tag *tag, *tag1;
 
-	LIST_FOREACH_SAFE(tag, &busdma->tags, link, tag1) {
-		LIST_REMOVE(tag, link);
-		proto_busdma_tag_destroy(tag);
-	}
+	LIST_FOREACH_SAFE(md, &busdma->mds, mds, md1)
+		proto_busdma_mem_free(busdma, md);
+	LIST_FOREACH_SAFE(tag, &busdma->tags, tags, tag1)
+		proto_busdma_tag_destroy(busdma, tag);
 	return (0);
 }
 
@@ -123,41 +220,46 @@ 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;
+	struct proto_md *md;
 	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;
+		busdma->bd_roottag = bus_get_dma_tag(sc->sc_dev);
+		error = proto_busdma_tag_create(busdma, NULL, ioc);
 		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;
+		error = proto_busdma_tag_create(busdma, tag, ioc);
 		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);
+		error = proto_busdma_tag_destroy(busdma, tag);
+		break;
+	case PROTO_IOC_BUSDMA_MEM_ALLOC:
+		tag = proto_busdma_tag_lookup(busdma, ioc->u.mem.tag);
+		if (tag == NULL) {
+			error = EINVAL;
+			break;
+		}
+		error = proto_busdma_mem_alloc(busdma, tag, ioc);
+		break;
+	case PROTO_IOC_BUSDMA_MEM_FREE:
+		md = proto_busdma_md_lookup(busdma, ioc->key);
+		if (md == NULL) {
+			error = EINVAL;
+			break;
+		}
+		error = proto_busdma_mem_free(busdma, md);
 		break;
 	default:
 		error = EINVAL;

sys/dev/proto/proto_busdma.h

@@ -29,14 +29,36 @@
 #ifndef _DEV_PROTO_BUSDMA_H_
 #define _DEV_PROTO_BUSDMA_H_
 
+struct proto_md;
+
 struct proto_tag {
-	LIST_ENTRY(proto_tag)	link;
+	LIST_ENTRY(proto_tag)	tags;
 	struct proto_tag	*parent;
-	bus_dma_tag_t		busdma_tag;
+	LIST_ENTRY(proto_tag)	peers;
+	LIST_HEAD(,proto_tag)	children;
+	LIST_HEAD(,proto_md)	mds;
+	bus_addr_t		align;
+	bus_addr_t		bndry;
+	bus_addr_t		maxaddr;
+	bus_size_t		maxsz;
+	bus_size_t		maxsegsz;
+	u_int			nsegs;
+	u_int			datarate;
+};
+
+struct proto_md {
+	LIST_ENTRY(proto_md)	mds;
+	LIST_ENTRY(proto_md)	peers;
+	struct proto_tag	*tag;
+	void			*kva;
+	bus_dma_tag_t		bd_tag;
+	bus_dmamap_t		bd_map;
 };
 
 struct proto_busdma {
 	LIST_HEAD(,proto_tag)	tags;
+	LIST_HEAD(,proto_md)	mds;
+	bus_dma_tag_t		bd_roottag;
 };
 
 struct proto_busdma *proto_busdma_attach(struct proto_softc *);

sys/dev/proto/proto_core.c

@@ -370,6 +370,10 @@ proto_ioctl(struct cdev *cdev, u_long cmd, caddr_t data, int fflag,
 	error = 0;
 	switch (cmd) {
 	case PROTO_IOC_REGION:
+		if (r->r_type == PROTO_RES_BUSDMA) {
+			error = EINVAL;
+			break;
+		}
 		region = (struct proto_ioc_region *)data;
 		region->size = r->r_size;
 		if (r->r_type == PROTO_RES_PCICFG)
@@ -378,6 +382,10 @@ proto_ioctl(struct cdev *cdev, u_long cmd, caddr_t data, int fflag,
 			region->address = rman_get_start(r->r_d.res);
 		break;
 	case PROTO_IOC_BUSDMA:
+		if (r->r_type != PROTO_RES_BUSDMA) {
+			error = EINVAL;
+			break;
+		}
 		busdma = (struct proto_ioc_busdma *)data;
 		error = proto_busdma_ioctl(sc, r->r_d.busdma, busdma);
 		break;

sys/dev/proto/proto_dev.h

@@ -45,6 +45,8 @@ struct proto_ioc_busdma {
 #define	PROTO_IOC_BUSDMA_TAG_CREATE	1
 #define	PROTO_IOC_BUSDMA_TAG_DERIVE	2
 #define	PROTO_IOC_BUSDMA_TAG_DESTROY	3
+#define	PROTO_IOC_BUSDMA_MEM_ALLOC	10
+#define	PROTO_IOC_BUSDMA_MEM_FREE	11
 	unsigned long	key;
 	union {
 		struct {
@@ -57,6 +59,12 @@ struct proto_ioc_busdma {
 			unsigned int	datarate;
 			unsigned int	flags;
 		} tag;
+		struct {
+			unsigned long	tag;
+			unsigned int	flags;
+			unsigned int	nsegs;
+			unsigned long	physaddr;
+		} mem;
 	} u;
 	unsigned long	result;
 };