[PATCH 30/54] Add arch/nios2/include/asm/dma-mapping.h

[franck.jullien at gmail.com]

From: Franck JULLIEN <franck.jullien at gmail.com>

Add arch/nios2/include/asm/dma-mapping.h

---
 arch/nios2/include/asm/dma-mapping.h |   25 +++++++++++++++++++++++++
 1 files changed, 25 insertions(+), 0 deletions(-)
 create mode 100644 arch/nios2/include/asm/dma-mapping.h

diff --git a/arch/nios2/include/asm/dma-mapping.h b/arch/nios2/include/asm/dma-mapping.h
new file mode 100644
index 0000000..f9159c5
--- /dev/null
+++ b/arch/nios2/include/asm/dma-mapping.h
@@ -0,0 +1,25 @@
+#ifndef __ASM_NIOS2_DMA_MAPPING_H
+#define __ASM_NIOS2_DMA_MAPPING_H
+
+#include <asm/cache.h>
+
+/* dma_alloc_coherent() return cache-line aligned allocation which is mapped
+ * to uncached io region.
+ *
+ * IO_REGION_BASE should be defined in board config header file
+ *   0x80000000 for nommu, 0xe0000000 for mmu
+ */
+
+static inline void *dma_alloc_coherent(size_t len, unsigned long *handle)
+{
+	void *addr = malloc(len + DCACHE_LINE_SIZE);
+	if (!addr)
+		return 0;
+	flush_dcache((unsigned long)addr, len + DCACHE_LINE_SIZE);
+	*handle = ((unsigned long)addr +
+		   (DCACHE_LINE_SIZE - 1)) &
+		~(DCACHE_LINE_SIZE - 1) & ~(IO_REGION_BASE);
+	return (void *)(*handle | IO_REGION_BASE);
+}
+
+#endif /* __ASM_NIOS2_DMA_MAPPING_H */
-- 
1.7.3.4