46 lines
1.3 KiB
C
46 lines
1.3 KiB
C
/*
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* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* vineetg: Feb 2009
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* -For AA4 board, kernel to DMA address APIs
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*/
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/*
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* kernel addresses are 0x800_000 based, while Bus addr are 0 based
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*/
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#ifndef __PLAT_DMA_ADDR_H
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#define __PLAT_DMA_ADDR_H
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#include <linux/device.h>
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static inline unsigned long plat_dma_addr_to_kernel(struct device *dev,
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dma_addr_t dma_addr)
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{
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return dma_addr + PAGE_OFFSET;
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}
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static inline dma_addr_t plat_kernel_addr_to_dma(struct device *dev, void *ptr)
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{
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unsigned long addr = (unsigned long)ptr;
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/*
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* To Catch buggy drivers which can call DMA map API with kernel vaddr
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* i.e. for buffers alloc via vmalloc or ioremap which are not
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* gaurnateed to be PHY contiguous and hence unfit for DMA anyways.
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* On ARC kernel virtual address is 0x7000_0000 to 0x7FFF_FFFF, so
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* ideally we want to check this range here, but our implementation is
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* better as it checks for even worse user virtual address as well.
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*/
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if (likely(addr >= PAGE_OFFSET))
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return addr - PAGE_OFFSET;
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BUG();
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return addr;
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}
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#endif
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