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 000000000000..3c55b87f8b63
--- /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_coherent         = dma_generic_alloc_coherent,
+        .free_coherent          = 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;
+}