1 files changed, 82 insertions, 0 deletions
diff --git a/arch/sh/kernel/dma-nommu.c b/arch/sh/kernel/dma-nommu.c
new file mode 100644
index 000000000..5b0bfcda6
--- /dev/null
+++ b/arch/sh/kernel/dma-nommu.c
@@ -0,0 +1,82 @@
+/*
+ * DMA mapping support for platforms lacking IOMMUs.
+ *
+ * Copyright (C) 2009  Paul Mundt
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/dma-mapping.h>
+#include <linux/io.h>
+
+static dma_addr_t nommu_map_page(struct device *dev, struct page *page,
+				 unsigned long offset, size_t size,
+				 enum dma_data_direction dir,
+				 struct dma_attrs *attrs)
+{
+	dma_addr_t addr = page_to_phys(page) + offset;
+
+	WARN_ON(size == 0);
+	dma_cache_sync(dev, page_address(page) + offset, size, dir);
+
+	return addr;
+}
+
+static int nommu_map_sg(struct device *dev, struct scatterlist *sg,
+			int nents, enum dma_data_direction dir,
+			struct dma_attrs *attrs)
+{
+	struct scatterlist *s;
+	int i;
+
+	WARN_ON(nents == 0 || sg[0].length == 0);
+
+	for_each_sg(sg, s, nents, i) {
+		BUG_ON(!sg_page(s));
+
+		dma_cache_sync(dev, sg_virt(s), s->length, dir);
+
+		s->dma_address = sg_phys(s);
+		s->dma_length = s->length;
+	}
+
+	return nents;
+}
+
+#ifdef CONFIG_DMA_NONCOHERENT
+static void nommu_sync_single(struct device *dev, dma_addr_t addr,
+			      size_t size, enum dma_data_direction dir)
+{
+	dma_cache_sync(dev, phys_to_virt(addr), size, dir);
+}
+
+static void nommu_sync_sg(struct device *dev, struct scatterlist *sg,
+			  int nelems, enum dma_data_direction dir)
+{
+	struct scatterlist *s;
+	int i;
+
+	for_each_sg(sg, s, nelems, i)
+		dma_cache_sync(dev, sg_virt(s), s->length, dir);
+}
+#endif
+
+struct dma_map_ops nommu_dma_ops = {
+	.alloc			= dma_generic_alloc_coherent,
+	.free			= dma_generic_free_coherent,
+	.map_page		= nommu_map_page,
+	.map_sg			= nommu_map_sg,
+#ifdef CONFIG_DMA_NONCOHERENT
+	.sync_single_for_device	= nommu_sync_single,
+	.sync_sg_for_device	= nommu_sync_sg,
+#endif
+	.is_phys		= 1,
+};
+
+void __init no_iommu_init(void)
+{
+	if (dma_ops)
+		return;
+	dma_ops = &nommu_dma_ops;
+}