1 files changed, 87 insertions, 0 deletions
diff --git a/arch/csky/mm/dma-mapping.c b/arch/csky/mm/dma-mapping.c
new file mode 100644
index 000000000..82447029f
--- /dev/null
+++ b/arch/csky/mm/dma-mapping.c
@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/cache.h>
+#include <linux/dma-map-ops.h>
+#include <linux/genalloc.h>
+#include <linux/highmem.h>
+#include <linux/io.h>
+#include <linux/mm.h>
+#include <linux/scatterlist.h>
+#include <linux/types.h>
+#include <asm/cache.h>
+
+static inline void cache_op(phys_addr_t paddr, size_t size,
+			    void (*fn)(unsigned long start, unsigned long end))
+{
+	struct page *page    = phys_to_page(paddr);
+	void *start          = __va(page_to_phys(page));
+	unsigned long offset = offset_in_page(paddr);
+	size_t left          = size;
+
+	do {
+		size_t len = left;
+
+		if (offset + len > PAGE_SIZE)
+			len = PAGE_SIZE - offset;
+
+		if (PageHighMem(page)) {
+			start = kmap_atomic(page);
+
+			fn((unsigned long)start + offset,
+					(unsigned long)start + offset + len);
+
+			kunmap_atomic(start);
+		} else {
+			fn((unsigned long)start + offset,
+					(unsigned long)start + offset + len);
+		}
+		offset = 0;
+
+		page++;
+		start += PAGE_SIZE;
+		left -= len;
+	} while (left);
+}
+
+static void dma_wbinv_set_zero_range(unsigned long start, unsigned long end)
+{
+	memset((void *)start, 0, end - start);
+	dma_wbinv_range(start, end);
+}
+
+void arch_dma_prep_coherent(struct page *page, size_t size)
+{
+	cache_op(page_to_phys(page), size, dma_wbinv_set_zero_range);
+}
+
+void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
+		enum dma_data_direction dir)
+{
+	switch (dir) {
+	case DMA_TO_DEVICE:
+		cache_op(paddr, size, dma_wb_range);
+		break;
+	case DMA_FROM_DEVICE:
+	case DMA_BIDIRECTIONAL:
+		cache_op(paddr, size, dma_wbinv_range);
+		break;
+	default:
+		BUG();
+	}
+}
+
+void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
+		enum dma_data_direction dir)
+{
+	switch (dir) {
+	case DMA_TO_DEVICE:
+		return;
+	case DMA_FROM_DEVICE:
+	case DMA_BIDIRECTIONAL:
+		cache_op(paddr, size, dma_inv_range);
+		break;
+	default:
+		BUG();
+	}
+}