From netbsd: implementations of _bus_dmamap_load_mbuf() and

_bus_dmamap_load_uio().

2 files changed, 185 insertions, 77 deletions

diff --git a/sys/arch/i386/i386/machdep.c b/sys/arch/i386/i386/machdep.c
index 2d06dc4c7d3..08bebc6137a 100644
--- a/sys/arch/i386/i386/machdep.c
+++ b/sys/arch/i386/i386/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.159 2001/05/05 23:25:37 art Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.160 2001/05/08 18:19:43 jason Exp $	*/
 /*	$NetBSD: machdep.c,v 1.214 1996/11/10 03:16:17 thorpej Exp $	*/
 
 /*-
@@ -281,6 +281,8 @@ void	consinit __P((void));
 
 int	bus_mem_add_mapping __P((bus_addr_t, bus_size_t,
 	    int, bus_space_handle_t *));
+int	_bus_dmamap_load_buffer __P((bus_dma_tag_t, bus_dmamap_t, void *,
+    bus_size_t, struct proc *, int, paddr_t *, int *, int));
 
 #ifdef KGDB
 #ifndef KGDB_DEVNAME
@@ -2850,101 +2852,69 @@ _bus_dmamap_load(t, map, buf, buflen, p, flags)
 	struct proc *p;
 	int flags;
 {
-	bus_size_t sgsize;
-	bus_addr_t curaddr, lastaddr, baddr, bmask;
-	vaddr_t vaddr = (vaddr_t)buf;
-	int first, seg;
-	pmap_t pmap;
+	bus_addr_t lastaddr;
+	int seg, error;
 
 	/*
 	 * Make sure that on error condition we return "no valid mappings".
 	 */
+	map->dm_mapsize = 0;
 	map->dm_nsegs = 0;
 
 	if (buflen > map->_dm_size)
 		return (EINVAL);
 
-	if (p != NULL)
-		pmap = p->p_vmspace->vm_map.pmap;
-	else
-		pmap = pmap_kernel();
-
-	lastaddr = ~0;		/* XXX gcc */
-	bmask  = ~(map->_dm_boundary - 1);
-
-	for (first = 1, seg = 0; buflen > 0; ) {
-		/*
-		 * Get the physical address for this segment.
-		 */
-		curaddr = (bus_addr_t)pmap_extract(pmap, (vm_offset_t)vaddr);
-
-		/*
-		 * Compute the segment size, and adjust counts.
-		 */
-		sgsize = NBPG - ((u_long)vaddr & PGOFSET);
-		if (buflen < sgsize)
-			sgsize = buflen;
-
-		/*
-		 * Make sure we don't cross any boundaries.
-		 */
-		if (map->_dm_boundary > 0) {
-			baddr = (curaddr + map->_dm_boundary) & bmask;
-			if (sgsize > (baddr - curaddr))
-				sgsize = (baddr - curaddr);
-		}
-
-		/*
-		 * Insert chunk into a segment, coalescing with
-		 * previous segment if possible.
-		 */
-		if (first) {
-			map->dm_segs[seg].ds_addr = curaddr;
-			map->dm_segs[seg].ds_len = sgsize;
-			first = 0;
-		} else {
-			if (curaddr == lastaddr &&
-			    (map->dm_segs[seg].ds_len + sgsize) <=
-			     map->_dm_maxsegsz &&
-			     (map->_dm_boundary == 0 ||
-			     (map->dm_segs[seg].ds_addr & bmask) ==
-			     (curaddr & bmask)))
-				map->dm_segs[seg].ds_len += sgsize;
-			else {
-				if (++seg >= map->_dm_segcnt)
-					break;
-				map->dm_segs[seg].ds_addr = curaddr;
-				map->dm_segs[seg].ds_len = sgsize;
-			}
-		}
-
-		lastaddr = curaddr + sgsize;
-		vaddr += sgsize;
-		buflen -= sgsize;
+	seg = 0;
+	error = _bus_dmamap_load_buffer(t, map, buf, buflen, p, flags,
+	    &lastaddr, &seg, 1);
+	if (error == 0) {
+		map->dm_mapsize = buflen;
+		map->dm_nsegs = seg + 1;
 	}
-
-	/*
-	 * Did we fit?
-	 */
-	if (buflen != 0)
-		return (EFBIG);		/* XXX better return value here? */
-
-	map->dm_nsegs = seg + 1;
-	return (0);
+	return (error);
 }
 
 /*
  * Like _bus_dmamap_load(), but for mbufs.
  */
 int
-_bus_dmamap_load_mbuf(t, map, m, flags)
+_bus_dmamap_load_mbuf(t, map, m0, flags)
 	bus_dma_tag_t t;
 	bus_dmamap_t map;
-	struct mbuf *m;
+	struct mbuf *m0;
 	int flags;
 {
+	paddr_t lastaddr;
+	int seg, error, first;
+	struct mbuf *m;
+
+	/*
+	 * 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("_bus_dmamap_load_mbuf: no packet header");
+#endif
+
+	if (m0->m_pkthdr.len > map->_dm_size)
+		return (EINVAL);
 
-	panic("_bus_dmamap_load: not implemented");
+	first = 1;
+	seg = 1;
+	error = 0;
+	for (m = m0; m != NULL && error == 0; m = m->m_next) {
+		error = _bus_dmamap_load_buffer(t, map, m->m_data, m->m_len,
+		    NULL, flags, &lastaddr, &seg, first);
+		first = 0;
+	}
+	if (error == 0) {
+		map->dm_mapsize = m0->m_pkthdr.len;
+		map->dm_nsegs = seg + 1;
+	}
+	return (error);
 }
 
 /*
@@ -2957,8 +2927,52 @@ _bus_dmamap_load_uio(t, map, uio, flags)
 	struct uio *uio;
 	int flags;
 {
+	paddr_t lastaddr;
+	int seg, i, error, first;
+	bus_size_t minlen, resid;
+	struct proc *p = NULL;
+	struct iovec *iov;
+	caddr_t addr;
+
+	/*
+	 * Make sure that on error condition we return "no valid mappings".
+	 */
+	map->dm_mapsize = 0;
+	map->dm_nsegs = 0;
+
+	resid = uio->uio_resid;
+	iov = uio->uio_iov;
+
+	if (uio->uio_segflg == UIO_USERSPACE) {
+		p = uio->uio_procp;
+#ifdef DIAGNOSTIC
+		if (p == NULL)
+			panic("_bus_dmamap_load_uio: USERSPACE but no proc");
+#endif
+	}
+
+	first = 1;
+	seg = 0;
+	error = 0;
+	for (i = 0; i < uio->uio_iovcnt && resid != 0 && error == 0; i++) {
+		/*
+		 * Now at the first iovec to load.  Load each iovec
+		 * until we have exhausted the residual count.
+		 */
+		minlen = resid < iov[i].iov_len ? resid : iov[i].iov_len;
+		addr = (caddr_t)iov[i].iov_base;
 
-	panic("_bus_dmamap_load_uio: not implemented");
+		error = _bus_dmamap_load_buffer(t, map, addr, minlen,
+		    p, flags, &lastaddr, &seg, first);
+		first = 0;
+
+		resid -= minlen;
+	}
+	if (error == 0) {
+		map->dm_mapsize = uio->uio_resid;
+		map->dm_nsegs = seg + 1;
+	}
+	return (error);
 }
 
 /*
@@ -3154,6 +3168,99 @@ _bus_dmamem_mmap(t, segs, nsegs, off, prot, flags)
 /**********************************************************************
  * DMA utility functions
  **********************************************************************/
+/*
+ * Utility function to load a linear buffer.  lastaddrp holds state
+ * between invocations (for multiple-buffer loads).  segp contains
+ * the starting segment on entrace, and the ending segment on exit.
+ * first indicates if this is the first invocation of this function.
+ */
+int
+_bus_dmamap_load_buffer(t, map, buf, buflen, p, flags, lastaddrp, segp, first)
+	bus_dma_tag_t t;
+	bus_dmamap_t map;
+	void *buf;
+	bus_size_t buflen;
+	struct proc *p;
+	int flags;
+	paddr_t *lastaddrp;
+	int *segp;
+	int first;
+{
+	bus_size_t sgsize;
+	bus_addr_t curaddr, lastaddr, baddr, bmask;
+	vaddr_t vaddr = (vaddr_t)buf;
+	int seg;
+	pmap_t pmap;
+
+	if (p != NULL)
+		pmap = p->p_vmspace->vm_map.pmap;
+	else
+		pmap = pmap_kernel();
+
+	lastaddr = *lastaddrp;
+	bmask  = ~(map->_dm_boundary - 1);
+
+	for (seg = *segp; buflen > 0 ; ) {
+		/*
+		 * Get the physical address for this segment.
+		 */
+		curaddr = (bus_addr_t)pmap_extract(pmap, (vm_offset_t)vaddr);
+
+		/*
+		 * Compute the segment size, and adjust counts.
+		 */
+		sgsize = PAGE_SIZE - ((u_long)vaddr & PGOFSET);
+		if (buflen < sgsize)
+			sgsize = buflen;
+
+		/*
+		 * Make sure we don't cross any boundaries.
+		 */
+		if (map->_dm_boundary > 0) {
+			baddr = (curaddr + map->_dm_boundary) & bmask;
+			if (sgsize > (baddr - curaddr))
+				sgsize = (baddr - curaddr);
+		}
+
+		/*
+		 * Insert chunk into a segment, coalescing with
+		 * previous segment if possible.
+		 */
+		if (first) {
+			map->dm_segs[seg].ds_addr = curaddr;
+			map->dm_segs[seg].ds_len = sgsize;
+			first = 0;
+		} else {
+			if (curaddr == lastaddr &&
+			    (map->dm_segs[seg].ds_len + sgsize) <=
+			     map->_dm_maxsegsz &&
+			    (map->_dm_boundary == 0 ||
+			     (map->dm_segs[seg].ds_addr & bmask) ==
+			     (curaddr & bmask)))
+				map->dm_segs[seg].ds_len += sgsize;
+			else {
+				if (++seg >= map->_dm_segcnt)
+					break;
+				map->dm_segs[seg].ds_addr = curaddr;
+				map->dm_segs[seg].ds_len = sgsize;
+			}
+		}
+
+		lastaddr = curaddr + sgsize;
+		vaddr += sgsize;
+		buflen -= sgsize;
+	}
+
+	*segp = seg;
+	*lastaddrp = lastaddr;
+
+	/*
+	 * Did we fit?
+	 */
+	if (buflen != 0)
+		return (EFBIG);		/* XXX better return value here? */
+	return (0);
+}
 
 /*
  * Allocate physical memory from the given physical address range.
diff --git a/sys/arch/i386/include/bus.h b/sys/arch/i386/include/bus.h
index 50aa7cd6452..d6a73c8b9bb 100644
--- a/sys/arch/i386/include/bus.h
+++ b/sys/arch/i386/include/bus.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bus.h,v 1.27 2001/02/06 23:13:31 mickey Exp $	*/
+/*	$OpenBSD: bus.h,v 1.28 2001/05/08 18:19:44 jason Exp $	*/
 /*	$NetBSD: bus.h,v 1.6 1996/11/10 03:19:25 thorpej Exp $	*/
 
 /*-
@@ -891,6 +891,7 @@ struct i386_bus_dmamap {
 	/*
 	 * PUBLIC MEMBERS: these are used by machine-independent code.
 	 */
+	bus_size_t	dm_mapsize;	/* size of the mapping */
 	int		dm_nsegs;	/* # valid segments in mapping */
 	bus_dma_segment_t dm_segs[1];	/* segments; variable length */
 };