Add BUS_DMA(9) support for mbufs

1 files changed, 128 insertions, 0 deletions

diff --git a/rtemsbsd/src/rtems-bsd-bus-dma-mbuf.c b/rtemsbsd/src/rtems-bsd-bus-dma-mbuf.c
new file mode 100644
index 00000000..45526686
--- /dev/null
+++ b/rtemsbsd/src/rtems-bsd-bus-dma-mbuf.c
@@ -0,0 +1,128 @@
+/**
+ * @file
+ *
+ * @ingroup rtems_bsd_rtems
+ *
+ * @brief TODO.
+ *
+ * File origin from FreeBSD "sys/powerpc/powerpc/busdma_machdep.c".
+ */
+
+/*-
+ * Copyright (c) 2012 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Obere Lagerstr. 30
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * Copyright (c) 1997, 1998 Justin T. Gibbs.
+ * 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,
+ *    without modification, immediately at the beginning of the file.
+ * 2. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 <freebsd/machine/rtems-bsd-config.h>
+#include <freebsd/machine/rtems-bsd-bus-dma.h>
+
+#include <freebsd/sys/mbuf.h>
+
+/*
+ * Like bus_dmamap_load(), but for mbufs.
+ */
+int
+bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
+		     struct mbuf *m0,
+		     bus_dmamap_callback2_t *callback, void *callback_arg,
+		     int flags)
+{
+	bus_dma_segment_t dm_segments[dmat->nsegments];
+	int nsegs, error;
+
+	M_ASSERTPKTHDR(m0);
+
+	flags |= BUS_DMA_NOWAIT;
+	nsegs = 0;
+	error = 0;
+	if (m0->m_pkthdr.len <= dmat->maxsize) {
+		int first = 1;
+		bus_addr_t lastaddr = 0;
+		struct mbuf *m;
+
+		for (m = m0; m != NULL && error == 0; m = m->m_next) {
+			if (m->m_len > 0) {
+				error = bus_dmamap_load_buffer(dmat, dm_segments,
+						m->m_data, m->m_len,
+						NULL, flags, &lastaddr,
+						&nsegs, first);
+				first = 0;
+			}
+		}
+	} else {
+		error = EINVAL;
+	}
+
+	if (error) {
+		/* force "no valid mappings" in callback */
+		(*callback)(callback_arg, dm_segments, 0, 0, error);
+	} else {
+		(*callback)(callback_arg, dm_segments,
+			    nsegs+1, m0->m_pkthdr.len, error);
+	}
+	return (error);
+}
+
+int
+bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map,
+			struct mbuf *m0, bus_dma_segment_t *segs, int *nsegs,
+			int flags)
+{
+	int error;
+
+	M_ASSERTPKTHDR(m0);
+
+	flags |= BUS_DMA_NOWAIT;
+	*nsegs = 0;
+	error = 0;
+	if (m0->m_pkthdr.len <= dmat->maxsize) {
+		int first = 1;
+		bus_addr_t lastaddr = 0;
+		struct mbuf *m;
+
+		for (m = m0; m != NULL && error == 0; m = m->m_next) {
+			if (m->m_len > 0) {
+				error = bus_dmamap_load_buffer(dmat, segs,
+						m->m_data, m->m_len,
+						NULL, flags, &lastaddr,
+						nsegs, first);
+				first = 0;
+			}
+		}
+	} else {
+		error = EINVAL;
+	}
+
+	/* XXX FIXME: Having to increment nsegs is really annoying */
+	++*nsegs;
+	return (error);
+}