powerpc: Move iommu dma ops from dma.c to dma-iommu.c

32-bit platforms are about to start using dma.c; move the iommu
dma ops into their own file to make this a bit cleaner.

Signed-off-by: Becky Bruce <becky.bruce@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

1 files changed, 103 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/dma-iommu.c b/arch/powerpc/kernel/dma-iommu.c
new file mode 100644
index 000000000000..01091f1d508c
--- /dev/null
+++ b/arch/powerpc/kernel/dma-iommu.c
@@ -0,0 +1,103 @@
+/*
+ * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corporation
+ *
+ * Provide default implementations of the DMA mapping callbacks for
+ * busses using the iommu infrastructure
+ */
+
+#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)
+{
+        return iommu_alloc_coherent(dev, dev->archdata.dma_data, size,
+                                    dma_handle, device_to_mask(dev), flag,
+                                    dev->archdata.numa_node);
+}
+
+static void dma_iommu_free_coherent(struct device *dev, size_t size,
+                                    void *vaddr, dma_addr_t dma_handle)
+{
+        iommu_free_coherent(dev->archdata.dma_data, size, vaddr, dma_handle);
+}
+
+/* Creates TCEs for a user provided buffer.  The user buffer must be
+ * contiguous real kernel storage (not vmalloc).  The address of the buffer
+ * passed here is the kernel (virtual) address of the buffer.  The buffer
+ * need not be page aligned, the dma_addr_t returned will point to the same
+ * byte within the page as vaddr.
+ */
+static dma_addr_t dma_iommu_map_single(struct device *dev, void *vaddr,
+                                       size_t size,
+                                       enum dma_data_direction direction,
+                                       struct dma_attrs *attrs)
+{
+        return iommu_map_single(dev, dev->archdata.dma_data, vaddr, size,
+                                device_to_mask(dev), direction, attrs);
+}
+
+
+static void dma_iommu_unmap_single(struct device *dev, dma_addr_t dma_handle,
+                                   size_t size,
+                                   enum dma_data_direction direction,
+                                   struct dma_attrs *attrs)
+{
+        iommu_unmap_single(dev->archdata.dma_data, 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 iommu_map_sg(dev, dev->archdata.dma_data, 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)
+{
+        iommu_unmap_sg(dev->archdata.dma_data, 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 = dev->archdata.dma_data;
+
+        if (!tbl || tbl->it_offset > mask) {
+                printk(KERN_INFO
+                       "Warning: IOMMU offset too big for device mask\n");
+                if (tbl)
+                        printk(KERN_INFO
+                               "mask: 0x%08lx, table offset: 0x%08lx\n",
+                                mask, tbl->it_offset);
+                else
+                        printk(KERN_INFO "mask: 0x%08lx, table unavailable\n",
+                                mask);
+                return 0;
+        } else
+                return 1;
+}
+
+struct dma_mapping_ops dma_iommu_ops = {
+        .alloc_coherent = dma_iommu_alloc_coherent,
+        .free_coherent  = dma_iommu_free_coherent,
+        .map_single     = dma_iommu_map_single,
+        .unmap_single   = dma_iommu_unmap_single,
+        .map_sg         = dma_iommu_map_sg,
+        .unmap_sg       = dma_iommu_unmap_sg,
+        .dma_supported  = dma_iommu_dma_supported,
+};
+EXPORT_SYMBOL(dma_iommu_ops);