235 lines
		
	
	
		
			6.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			235 lines
		
	
	
		
			6.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* DMA mapping routines for the MN10300 arch
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 *
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 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
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 * Written by David Howells (dhowells@redhat.com)
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 *
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 * This program is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU General Public Licence
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 * as published by the Free Software Foundation; either version
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 * 2 of the Licence, or (at your option) any later version.
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 */
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#ifndef _ASM_DMA_MAPPING_H
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#define _ASM_DMA_MAPPING_H
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#include <linux/mm.h>
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#include <linux/scatterlist.h>
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#include <asm/cache.h>
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#include <asm/io.h>
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extern void *dma_alloc_coherent(struct device *dev, size_t size,
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				dma_addr_t *dma_handle, int flag);
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extern void dma_free_coherent(struct device *dev, size_t size,
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			      void *vaddr, dma_addr_t dma_handle);
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#define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent((d), (s), (h), (f))
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#define dma_free_noncoherent(d, s, v, h)  dma_free_coherent((d), (s), (v), (h))
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/*
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 * Map a single buffer of the indicated size for DMA in streaming mode.  The
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 * 32-bit bus address to use is returned.
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 *
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 * Once the device is given the dma address, the device owns this memory until
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 * either pci_unmap_single or pci_dma_sync_single is performed.
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 */
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static inline
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dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
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			  enum dma_data_direction direction)
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{
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	BUG_ON(direction == DMA_NONE);
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	mn10300_dcache_flush_inv();
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	return virt_to_bus(ptr);
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}
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/*
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 * Unmap a single streaming mode DMA translation.  The dma_addr and size must
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 * match what was provided for in a previous pci_map_single call.  All other
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 * usages are undefined.
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 *
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 * After this call, reads by the cpu to the buffer are guarenteed to see
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 * whatever the device wrote there.
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 */
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static inline
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void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
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		      enum dma_data_direction direction)
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{
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	BUG_ON(direction == DMA_NONE);
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}
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/*
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 * Map a set of buffers described by scatterlist in streaming mode for DMA.
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 * This is the scather-gather version of the above pci_map_single interface.
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 * Here the scatter gather list elements are each tagged with the appropriate
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 * dma address and length.  They are obtained via sg_dma_{address,length}(SG).
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 *
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 * NOTE: An implementation may be able to use a smaller number of DMA
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 *       address/length pairs than there are SG table elements.  (for example
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 *       via virtual mapping capabilities) The routine returns the number of
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 *       addr/length pairs actually used, at most nents.
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 *
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 * Device ownership issues as mentioned above for pci_map_single are the same
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 * here.
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 */
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static inline
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int dma_map_sg(struct device *dev, struct scatterlist *sglist, int nents,
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	       enum dma_data_direction direction)
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{
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	struct scatterlist *sg;
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	int i;
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	BUG_ON(!valid_dma_direction(direction));
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	WARN_ON(nents == 0 || sglist[0].length == 0);
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	for_each_sg(sglist, sg, nents, i) {
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		BUG_ON(!sg_page(sg));
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		sg->dma_address = sg_phys(sg);
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	}
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	mn10300_dcache_flush_inv();
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	return nents;
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}
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/*
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 * Unmap a set of streaming mode DMA translations.
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 * Again, cpu read rules concerning calls here are the same as for
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 * pci_unmap_single() above.
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 */
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static inline
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void dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
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		  enum dma_data_direction direction)
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{
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	BUG_ON(!valid_dma_direction(direction));
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}
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/*
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 * pci_{map,unmap}_single_page maps a kernel page to a dma_addr_t. identical
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 * to pci_map_single, but takes a struct page instead of a virtual address
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 */
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static inline
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dma_addr_t dma_map_page(struct device *dev, struct page *page,
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			unsigned long offset, size_t size,
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			enum dma_data_direction direction)
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{
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	BUG_ON(direction == DMA_NONE);
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	return page_to_bus(page) + offset;
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}
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static inline
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void dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
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		    enum dma_data_direction direction)
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{
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	BUG_ON(direction == DMA_NONE);
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}
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/*
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 * Make physical memory consistent for a single streaming mode DMA translation
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 * after a transfer.
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 *
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 * If you perform a pci_map_single() but wish to interrogate the buffer using
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 * the cpu, yet do not wish to teardown the PCI dma mapping, you must call this
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 * function before doing so.  At the next point you give the PCI dma address
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 * back to the card, the device again owns the buffer.
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 */
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static inline
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void dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
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			     size_t size, enum dma_data_direction direction)
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{
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}
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static inline
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void dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle,
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				size_t size, enum dma_data_direction direction)
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{
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	mn10300_dcache_flush_inv();
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}
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static inline
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void dma_sync_single_range_for_cpu(struct device *dev, dma_addr_t dma_handle,
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				   unsigned long offset, size_t size,
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				   enum dma_data_direction direction)
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{
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}
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static inline void
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dma_sync_single_range_for_device(struct device *dev, dma_addr_t dma_handle,
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				 unsigned long offset, size_t size,
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				 enum dma_data_direction direction)
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{
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	mn10300_dcache_flush_inv();
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}
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/*
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 * Make physical memory consistent for a set of streaming mode DMA translations
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 * after a transfer.
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 *
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 * The same as pci_dma_sync_single but for a scatter-gather list, same rules
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 * and usage.
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 */
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static inline
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void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
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			 int nelems, enum dma_data_direction direction)
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{
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}
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static inline
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void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
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			    int nelems, enum dma_data_direction direction)
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{
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	mn10300_dcache_flush_inv();
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}
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static inline
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int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
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{
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	return 0;
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}
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/*
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 * Return whether the given PCI device DMA address mask can be supported
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 * properly.  For example, if your device can only drive the low 24-bits during
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 * PCI bus mastering, then you would pass 0x00ffffff as the mask to this
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 * function.
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 */
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static inline
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int dma_supported(struct device *dev, u64 mask)
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{
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	/*
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	 * we fall back to GFP_DMA when the mask isn't all 1s, so we can't
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	 * guarantee allocations that must be within a tighter range than
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	 * GFP_DMA
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	 */
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	if (mask < 0x00ffffff)
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		return 0;
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	return 1;
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}
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static inline
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int dma_set_mask(struct device *dev, u64 mask)
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{
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	if (!dev->dma_mask || !dma_supported(dev, mask))
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		return -EIO;
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	*dev->dma_mask = mask;
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	return 0;
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}
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static inline
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int dma_get_cache_alignment(void)
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{
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	return 1 << L1_CACHE_SHIFT;
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}
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#define dma_is_consistent(d)	(1)
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static inline
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void dma_cache_sync(void *vaddr, size_t size,
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		    enum dma_data_direction direction)
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{
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	mn10300_dcache_flush_inv();
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}
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#endif
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