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Commit a8eb92d0 authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

arc: fix arc_dma_{map,unmap}_page 



These functions should perform the same cache synchronoization as calling
arc_dma_sync_single_for_{cpu,device} in addition to doing any required
address translation or mapping [1].  Ensure they actually do that by calling
arc_dma_sync_single_for_{cpu,device} instead of passing the dir argument
along to _dma_cache_sync.

The now unused _dma_cache_sync function is removed as well.

[1] in fact various drivers rely on that by passing DMA_ATTR_SKIP_CPU_SYNC
to the map/unmap routines and doing the cache synchronization manually.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Tested-by: default avatarAlexey Brodkin <abrodkin@synopsys.com>
Acked-by: default avatarVineet Gupta <vgupta@synopsys.com>
parent b5917410

arch/arc/mm/dma.c

+2 −25
Original line number Original line Diff line number Diff line
@@ -130,29 +130,6 @@ static int arc_dma_mmap(struct device *dev, struct vm_area_struct *vma, 
	return ret;

	return ret;

}

}





/*

 * streaming DMA Mapping API...

 * CPU accesses page via normal paddr, thus needs to explicitly made

 * consistent before each use

 */

static void _dma_cache_sync(phys_addr_t paddr, size_t size,

		enum dma_data_direction dir)

{

	switch (dir) {

	case DMA_FROM_DEVICE:

		dma_cache_inv(paddr, size);

		break;

	case DMA_TO_DEVICE:

		dma_cache_wback(paddr, size);

		break;

	case DMA_BIDIRECTIONAL:

		dma_cache_wback_inv(paddr, size);

		break;

	default:

		pr_err("Invalid DMA dir [%d] for OP @ %pa[p]\n", dir, &paddr);

	}

}



static void arc_dma_sync_single_for_device(struct device *dev,

static void arc_dma_sync_single_for_device(struct device *dev,

		dma_addr_t dma_handle, size_t size, enum dma_data_direction dir)

		dma_addr_t dma_handle, size_t size, enum dma_data_direction dir)

{

{
@@ -185,7 +162,7 @@ static dma_addr_t arc_dma_map_page(struct device *dev, struct page *page, 
	phys_addr_t paddr = page_to_phys(page) + offset;

	phys_addr_t paddr = page_to_phys(page) + offset;





	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))

	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))

		_dma_cache_sync(paddr, size, dir);

		arc_dma_sync_single_for_device(dev, paddr, size, dir);





	return paddr;

	return paddr;

}

}
@@ -205,7 +182,7 @@ static void arc_dma_unmap_page(struct device *dev, dma_addr_t handle, 
	phys_addr_t paddr = handle;

	phys_addr_t paddr = handle;





	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))

	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))

		_dma_cache_sync(paddr, size, dir);

		arc_dma_sync_single_for_cpu(dev, paddr, size, dir);

}

}





static int arc_dma_map_sg(struct device *dev, struct scatterlist *sg,

static int arc_dma_map_sg(struct device *dev, struct scatterlist *sg,