[U-Boot] [PATCH v2] nios2: add dma_alloc_coherent with asm-nios2/dma-mapping.h

[Thomas Chou]

This function return cache-line aligned allocation which is mapped
to uncached io region.

Signed-off-by: Thomas Chou <thomas at wytron.com.tw>
---
 include/asm-nios2/dma-mapping.h |   23 +++++++++++++++++++++++
 1 files changed, 23 insertions(+), 0 deletions(-)
 create mode 100644 include/asm-nios2/dma-mapping.h

diff --git a/include/asm-nios2/dma-mapping.h b/include/asm-nios2/dma-mapping.h
new file mode 100644
index 0000000..1350e3b
--- /dev/null
+++ b/include/asm-nios2/dma-mapping.h
@@ -0,0 +1,23 @@
+#ifndef __ASM_NIOS2_DMA_MAPPING_H
+#define __ASM_NIOS2_DMA_MAPPING_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 + CONFIG_SYS_DCACHELINE_SIZE);
+	if (!addr)
+		return 0;
+	flush_dcache((unsigned long)addr, len + CONFIG_SYS_DCACHELINE_SIZE);
+	*handle = ((unsigned long)addr +
+		   (CONFIG_SYS_DCACHELINE_SIZE - 1)) &
+		~(CONFIG_SYS_DCACHELINE_SIZE - 1) & ~(IO_REGION_BASE);
+	return (void *)(*handle | IO_REGION_BASE);
+}
+
+#endif /* __ASM_NIOS2_DMA_MAPPING_H */
-- 
1.6.6.1