1 files changed, 119 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/dma-iommu.c b/arch/powerpc/kernel/dma-iommu.c
new file mode 100644
index 000000000..4c68bfe41
--- /dev/null
+++ b/arch/powerpc/kernel/dma-iommu.c
@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corporation
+ *
+ * Provide default implementations of the DMA mapping callbacks for
+ * busses using the iommu infrastructure
+ */
+
+#include <linux/export.h>
+#include <asm/iommu.h>
+
+/*
+ * Generic iommu implementation
+ */
+
+/* Allocates a contiguous real buffer and creates mappings over it.
+ * Returns the virtual address of the buffer and sets dma_handle
+ * to the dma address (mapping) of the first page.
+ */
+static void *dma_iommu_alloc_coherent(struct device *dev, size_t size,
+				      dma_addr_t *dma_handle, gfp_t flag,
+				      struct dma_attrs *attrs)
+{
+	return iommu_alloc_coherent(dev, get_iommu_table_base(dev), size,
+				    dma_handle, dev->coherent_dma_mask, flag,
+				    dev_to_node(dev));
+}
+
+static void dma_iommu_free_coherent(struct device *dev, size_t size,
+				    void *vaddr, dma_addr_t dma_handle,
+				    struct dma_attrs *attrs)
+{
+	iommu_free_coherent(get_iommu_table_base(dev), size, vaddr, dma_handle);
+}
+
+/* Creates TCEs for a user provided buffer.  The user buffer must be
+ * contiguous real kernel storage (not vmalloc).  The address passed here
+ * comprises a page address and offset into that page. The dma_addr_t
+ * returned will point to the same byte within the page as was passed in.
+ */
+static dma_addr_t dma_iommu_map_page(struct device *dev, struct page *page,
+				     unsigned long offset, size_t size,
+				     enum dma_data_direction direction,
+				     struct dma_attrs *attrs)
+{
+	return iommu_map_page(dev, get_iommu_table_base(dev), page, offset,
+			      size, device_to_mask(dev), direction, attrs);
+}
+
+
+static void dma_iommu_unmap_page(struct device *dev, dma_addr_t dma_handle,
+				 size_t size, enum dma_data_direction direction,
+				 struct dma_attrs *attrs)
+{
+	iommu_unmap_page(get_iommu_table_base(dev), dma_handle, size, direction,
+			 attrs);
+}
+
+
+static int dma_iommu_map_sg(struct device *dev, struct scatterlist *sglist,
+			    int nelems, enum dma_data_direction direction,
+			    struct dma_attrs *attrs)
+{
+	return ppc_iommu_map_sg(dev, get_iommu_table_base(dev), sglist, nelems,
+				device_to_mask(dev), direction, attrs);
+}
+
+static void dma_iommu_unmap_sg(struct device *dev, struct scatterlist *sglist,
+		int nelems, enum dma_data_direction direction,
+		struct dma_attrs *attrs)
+{
+	ppc_iommu_unmap_sg(get_iommu_table_base(dev), sglist, nelems,
+			   direction, attrs);
+}
+
+/* We support DMA to/from any memory page via the iommu */
+static int dma_iommu_dma_supported(struct device *dev, u64 mask)
+{
+	struct iommu_table *tbl = get_iommu_table_base(dev);
+
+	if (!tbl) {
+		dev_info(dev, "Warning: IOMMU dma not supported: mask 0x%08llx"
+			", table unavailable\n", mask);
+		return 0;
+	}
+
+	if (tbl->it_offset > (mask >> tbl->it_page_shift)) {
+		dev_info(dev, "Warning: IOMMU offset too big for device mask\n");
+		dev_info(dev, "mask: 0x%08llx, table offset: 0x%08lx\n",
+				mask, tbl->it_offset << tbl->it_page_shift);
+		return 0;
+	} else
+		return 1;
+}
+
+static u64 dma_iommu_get_required_mask(struct device *dev)
+{
+	struct iommu_table *tbl = get_iommu_table_base(dev);
+	u64 mask;
+	if (!tbl)
+		return 0;
+
+	mask = 1ULL < (fls_long(tbl->it_offset + tbl->it_size) - 1);
+	mask += mask - 1;
+
+	return mask;
+}
+
+struct dma_map_ops dma_iommu_ops = {
+	.alloc			= dma_iommu_alloc_coherent,
+	.free			= dma_iommu_free_coherent,
+	.mmap			= dma_direct_mmap_coherent,
+	.map_sg			= dma_iommu_map_sg,
+	.unmap_sg		= dma_iommu_unmap_sg,
+	.dma_supported		= dma_iommu_dma_supported,
+	.map_page		= dma_iommu_map_page,
+	.unmap_page		= dma_iommu_unmap_page,
+	.get_required_mask	= dma_iommu_get_required_mask,
+};
+EXPORT_SYMBOL(dma_iommu_ops);