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-rw-r--r--arch/powerpc/kernel/dma-iommu.c119
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);