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80 lines
1.8 KiB
80 lines
1.8 KiB
#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_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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