nios2: DMA mapping API

This patch adds support for the DMA mapping API.

Signed-off-by: Ley Foon Tan <lftan@altera.com>

arch/nios2/mm/dma-mapping.c

@@ -0,0 +1,186 @@
+/*
+ * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
+ * Copyright (C) 2009 Wind River Systems Inc
+ *  Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
+ *
+ * Based on DMA code from MIPS.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/export.h>
+#include <linux/string.h>
+#include <linux/scatterlist.h>
+#include <linux/dma-mapping.h>
+#include <linux/io.h>
+#include <linux/cache.h>
+#include <asm/cacheflush.h>
+
+
+void *dma_alloc_coherent(struct device *dev, size_t size,
+			    dma_addr_t *dma_handle, gfp_t gfp)
+{
+	void *ret;
+
+	/* ignore region specifiers */
+	gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
+
+	/* optimized page clearing */
+	gfp |= __GFP_ZERO;
+
+	if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
+		gfp |= GFP_DMA;
+
+	ret = (void *) __get_free_pages(gfp, get_order(size));
+	if (ret != NULL) {
+		*dma_handle = virt_to_phys(ret);
+		flush_dcache_range((unsigned long) ret,
+			(unsigned long) ret + size);
+		ret = UNCAC_ADDR(ret);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(dma_alloc_coherent);
+
+void dma_free_coherent(struct device *dev, size_t size, void *vaddr,
+			dma_addr_t dma_handle)
+{
+	unsigned long addr = (unsigned long) CAC_ADDR((unsigned long) vaddr);
+
+	free_pages(addr, get_order(size));
+}
+EXPORT_SYMBOL(dma_free_coherent);
+
+int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
+		enum dma_data_direction direction)
+{
+	int i;
+
+	BUG_ON(!valid_dma_direction(direction));
+
+	for_each_sg(sg, sg, nents, i) {
+		void *addr;
+
+		addr = sg_virt(sg);
+		if (addr) {
+			__dma_sync_for_device(addr, sg->length, direction);
+			sg->dma_address = sg_phys(sg);
+		}
+	}
+
+	return nents;
+}
+EXPORT_SYMBOL(dma_map_sg);
+
+dma_addr_t dma_map_page(struct device *dev, struct page *page,
+			unsigned long offset, size_t size,
+			enum dma_data_direction direction)
+{
+	void *addr;
+
+	BUG_ON(!valid_dma_direction(direction));
+
+	addr = page_address(page) + offset;
+	__dma_sync_for_device(addr, size, direction);
+
+	return page_to_phys(page) + offset;
+}
+EXPORT_SYMBOL(dma_map_page);
+
+void dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
+		    enum dma_data_direction direction)
+{
+	BUG_ON(!valid_dma_direction(direction));
+
+	__dma_sync_for_cpu(phys_to_virt(dma_address), size, direction);
+}
+EXPORT_SYMBOL(dma_unmap_page);
+
+void dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
+		  enum dma_data_direction direction)
+{
+	void *addr;
+	int i;
+
+	BUG_ON(!valid_dma_direction(direction));
+
+	if (direction == DMA_TO_DEVICE)
+		return;
+
+	for_each_sg(sg, sg, nhwentries, i) {
+		addr = sg_virt(sg);
+		if (addr)
+			__dma_sync_for_cpu(addr, sg->length, direction);
+	}
+}
+EXPORT_SYMBOL(dma_unmap_sg);
+
+void dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
+			     size_t size, enum dma_data_direction direction)
+{
+	BUG_ON(!valid_dma_direction(direction));
+
+	__dma_sync_for_cpu(phys_to_virt(dma_handle), size, direction);
+}
+EXPORT_SYMBOL(dma_sync_single_for_cpu);
+
+void dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle,
+				size_t size, enum dma_data_direction direction)
+{
+	BUG_ON(!valid_dma_direction(direction));
+
+	__dma_sync_for_device(phys_to_virt(dma_handle), size, direction);
+}
+EXPORT_SYMBOL(dma_sync_single_for_device);
+
+void dma_sync_single_range_for_cpu(struct device *dev, dma_addr_t dma_handle,
+					unsigned long offset, size_t size,
+					enum dma_data_direction direction)
+{
+	BUG_ON(!valid_dma_direction(direction));
+
+	__dma_sync_for_cpu(phys_to_virt(dma_handle), size, direction);
+}
+EXPORT_SYMBOL(dma_sync_single_range_for_cpu);
+
+void dma_sync_single_range_for_device(struct device *dev, dma_addr_t dma_handle,
+					unsigned long offset, size_t size,
+					enum dma_data_direction direction)
+{
+	BUG_ON(!valid_dma_direction(direction));
+
+	__dma_sync_for_device(phys_to_virt(dma_handle), size, direction);
+}
+EXPORT_SYMBOL(dma_sync_single_range_for_device);
+
+void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nelems,
+			 enum dma_data_direction direction)
+{
+	int i;
+
+	BUG_ON(!valid_dma_direction(direction));
+
+	/* Make sure that gcc doesn't leave the empty loop body.  */
+	for_each_sg(sg, sg, nelems, i)
+		__dma_sync_for_cpu(sg_virt(sg), sg->length, direction);
+}
+EXPORT_SYMBOL(dma_sync_sg_for_cpu);
+
+void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
+				int nelems, enum dma_data_direction direction)
+{
+	int i;
+
+	BUG_ON(!valid_dma_direction(direction));
+
+	/* Make sure that gcc doesn't leave the empty loop body.  */
+	for_each_sg(sg, sg, nelems, i)
+		__dma_sync_for_device(sg_virt(sg), sg->length, direction);
+
+}
+EXPORT_SYMBOL(dma_sync_sg_for_device);