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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| 
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| #include <linux/mm.h>
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| #include <linux/scatterlist.h>
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| 
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| #include <asm/cache.h>
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| #include <asm/io.h>
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| 
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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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| 
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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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| 
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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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| /*
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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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| /*
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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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| /*
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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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| 
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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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| 
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| 	for_each_sg(sglist, sg, nents, i) {
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| 		BUG_ON(!sg_page(sg));
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| 
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| 		sg->dma_address = sg_phys(sg);
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| 	}
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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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| /*
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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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| /*
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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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| 
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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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| /*
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| /*
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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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| 
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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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| 
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| 	*dev->dma_mask = mask;
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| 	return 0;
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| }
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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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| 
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| #define dma_is_consistent(d)	(1)
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| 
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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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| 
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| #endif
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