7e89aa7680
The DMA_ATTR_FORCE_COHERENT DMA attribute can be used to force a buffer to be mapped as IO coherent. The DMA_ATTR_FORCE_NON_COHERENT DMA attribute can be used to force a buffer to not be mapped as IO coherent. Change-Id: Id80d77a5ccd797eec36b45b320423fb46c9f5861 Signed-off-by: Liam Mark <lmark@codeaurora.org>
86 lines
2 KiB
C
86 lines
2 KiB
C
#ifndef _DMA_ATTR_H
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#define _DMA_ATTR_H
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#include <linux/bitmap.h>
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#include <linux/bitops.h>
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#include <linux/bug.h>
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/**
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* an enum dma_attr represents an attribute associated with a DMA
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* mapping. The semantics of each attribute should be defined in
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* Documentation/DMA-attributes.txt.
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*/
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enum dma_attr {
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DMA_ATTR_WRITE_BARRIER,
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DMA_ATTR_WEAK_ORDERING,
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DMA_ATTR_WRITE_COMBINE,
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DMA_ATTR_NON_CONSISTENT,
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DMA_ATTR_NO_KERNEL_MAPPING,
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DMA_ATTR_SKIP_CPU_SYNC,
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DMA_ATTR_FORCE_CONTIGUOUS,
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DMA_ATTR_STRONGLY_ORDERED,
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DMA_ATTR_SKIP_ZEROING,
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DMA_ATTR_NO_DELAYED_UNMAP,
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DMA_ATTR_EXEC_MAPPING,
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DMA_ATTR_FORCE_COHERENT,
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DMA_ATTR_FORCE_NON_COHERENT,
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DMA_ATTR_MAX,
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};
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#define __DMA_ATTRS_LONGS BITS_TO_LONGS(DMA_ATTR_MAX)
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/**
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* struct dma_attrs - an opaque container for DMA attributes
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* @flags - bitmask representing a collection of enum dma_attr
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*/
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struct dma_attrs {
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unsigned long flags[__DMA_ATTRS_LONGS];
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};
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#define DEFINE_DMA_ATTRS(x) \
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struct dma_attrs x = { \
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.flags = { [0 ... __DMA_ATTRS_LONGS-1] = 0 }, \
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}
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static inline void init_dma_attrs(struct dma_attrs *attrs)
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{
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bitmap_zero(attrs->flags, __DMA_ATTRS_LONGS);
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}
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#ifdef CONFIG_HAVE_DMA_ATTRS
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/**
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* dma_set_attr - set a specific attribute
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* @attr: attribute to set
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* @attrs: struct dma_attrs (may be NULL)
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*/
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static inline void dma_set_attr(enum dma_attr attr, struct dma_attrs *attrs)
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{
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if (attrs == NULL)
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return;
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BUG_ON(attr >= DMA_ATTR_MAX);
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__set_bit(attr, attrs->flags);
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}
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/**
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* dma_get_attr - check for a specific attribute
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* @attr: attribute to set
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* @attrs: struct dma_attrs (may be NULL)
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*/
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static inline int dma_get_attr(enum dma_attr attr, struct dma_attrs *attrs)
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{
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if (attrs == NULL)
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return 0;
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BUG_ON(attr >= DMA_ATTR_MAX);
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return test_bit(attr, attrs->flags);
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}
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#else /* !CONFIG_HAVE_DMA_ATTRS */
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static inline void dma_set_attr(enum dma_attr attr, struct dma_attrs *attrs)
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{
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}
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static inline int dma_get_attr(enum dma_attr attr, struct dma_attrs *attrs)
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{
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return 0;
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}
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#endif /* CONFIG_HAVE_DMA_ATTRS */
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#endif /* _DMA_ATTR_H */
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