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Commit 23bc9873 authored by Russell King's avatar Russell King
Browse files

ARM: dmabounce: separate out decision to bounce 



Move the decision to perform DMA bouncing out of map_single() into its
own stand-alone function.

Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 71695dd8

arch/arm/common/dmabounce.c

+28 −18
Original line number Diff line number Diff line
@@ -219,36 +219,46 @@ static struct safe_buffer *find_safe_buffer_dev(struct device *dev, 
	return find_safe_buffer(dev->archdata.dmabounce, dma_addr);

}



static int needs_bounce(struct device *dev, dma_addr_t dma_addr, size_t size)

{

	if (!dev || !dev->archdata.dmabounce)

		return 0;



	if (dev->dma_mask) {

		unsigned long limit, mask = *dev->dma_mask;



		limit = (mask + 1) & ~mask;

		if (limit && size > limit) {

			dev_err(dev, "DMA mapping too big (requested %#x "

				"mask %#Lx)\n", size, *dev->dma_mask);

			return -E2BIG;

		}



		/* Figure out if we need to bounce from the DMA mask. */

		if ((dma_addr | (dma_addr + size - 1)) & ~mask)

			return 1;

	}



	return dma_needs_bounce(dev, dma_addr, size) ? 1 : 0;

}



static inline dma_addr_t map_single(struct device *dev, void *ptr, size_t size,

		enum dma_data_direction dir)

{

	struct dmabounce_device_info *device_info = dev->archdata.dmabounce;

	dma_addr_t dma_addr;

	int needs_bounce = 0;

	int ret;



	if (device_info)

		DO_STATS ( device_info->map_op_count++ );



	dma_addr = virt_to_dma(dev, ptr);



	if (dev->dma_mask) {

		unsigned long mask = *dev->dma_mask;

		unsigned long limit;



		limit = (mask + 1) & ~mask;

		if (limit && size > limit) {

			dev_err(dev, "DMA mapping too big (requested %#x "

				"mask %#Lx)\n", size, *dev->dma_mask);

	ret = needs_bounce(dev, dma_addr, size);

	if (ret < 0)

		return ~0;

		}



		/*

		 * Figure out if we need to bounce from the DMA mask.

		 */

		needs_bounce = (dma_addr | (dma_addr + size - 1)) & ~mask;

	}



	if (device_info && (needs_bounce || dma_needs_bounce(dev, dma_addr, size))) {

	if (ret > 0) {

		struct safe_buffer *buf;



		buf = alloc_safe_buffer(device_info, ptr, size, dir);