This patch adds support for the DMA mapping API. It uses dma_map_ops for
flexibility and it currently supports swiotlb. This patch could be
simplified further if the DMA accesses are coherent (not mandated by the
architecture) or if corresponding hooks are placed in the generic
swiotlb code to deal with cache maintenance.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---
 arch/arm64/include/asm/dma-mapping.h |  124 ++++++++++++++++++++
 arch/arm64/mm/dma-mapping.c          |  208 ++++++++++++++++++++++++++++++++++
 2 files changed, 332 insertions(+), 0 deletions(-)
 create mode 100644 arch/arm64/include/asm/dma-mapping.h
 create mode 100644 arch/arm64/mm/dma-mapping.c

diff --git a/arch/arm64/include/asm/dma-mapping.h b/arch/arm64/include/asm/dma-mapping.h
new file mode 100644
index 0000000..538f4b4
--- /dev/null
+++ b/arch/arm64/include/asm/dma-mapping.h

@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef __ASM_DMA_MAPPING_H
+#define __ASM_DMA_MAPPING_H
+
+#ifdef __KERNEL__
+
+#include <linux/types.h>
+#include <linux/vmalloc.h>
+
+#include <asm-generic/dma-coherent.h>
+
+#define ARCH_HAS_DMA_GET_REQUIRED_MASK
+
+extern struct dma_map_ops *dma_ops;

+static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+{
+	if (unlikely(!dev) || !dev->archdata.dma_ops)
+		return dma_ops;
+	else
+		return dev->archdata.dma_ops;
+}