0,0 → 1,80 |
#ifndef _DMA_ATTR_H |
#define _DMA_ATTR_H |
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#include <linux/bitmap.h> |
#include <linux/bitops.h> |
#include <linux/bug.h> |
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/** |
* an enum dma_attr represents an attribute associated with a DMA |
* mapping. The semantics of each attribute should be defined in |
* Documentation/DMA-attributes.txt. |
*/ |
enum dma_attr { |
DMA_ATTR_WRITE_BARRIER, |
DMA_ATTR_WEAK_ORDERING, |
DMA_ATTR_WRITE_COMBINE, |
DMA_ATTR_NON_CONSISTENT, |
DMA_ATTR_NO_KERNEL_MAPPING, |
DMA_ATTR_SKIP_CPU_SYNC, |
DMA_ATTR_FORCE_CONTIGUOUS, |
DMA_ATTR_MAX, |
}; |
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#define __DMA_ATTRS_LONGS BITS_TO_LONGS(DMA_ATTR_MAX) |
|
/** |
* struct dma_attrs - an opaque container for DMA attributes |
* @flags - bitmask representing a collection of enum dma_attr |
*/ |
struct dma_attrs { |
unsigned long flags[__DMA_ATTRS_LONGS]; |
}; |
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#define DEFINE_DMA_ATTRS(x) \ |
struct dma_attrs x = { \ |
.flags = { [0 ... __DMA_ATTRS_LONGS-1] = 0 }, \ |
} |
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static inline void init_dma_attrs(struct dma_attrs *attrs) |
{ |
bitmap_zero(attrs->flags, __DMA_ATTRS_LONGS); |
} |
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#ifdef CONFIG_HAVE_DMA_ATTRS |
/** |
* dma_set_attr - set a specific attribute |
* @attr: attribute to set |
* @attrs: struct dma_attrs (may be NULL) |
*/ |
static inline void dma_set_attr(enum dma_attr attr, struct dma_attrs *attrs) |
{ |
if (attrs == NULL) |
return; |
BUG_ON(attr >= DMA_ATTR_MAX); |
__set_bit(attr, attrs->flags); |
} |
|
/** |
* dma_get_attr - check for a specific attribute |
* @attr: attribute to set |
* @attrs: struct dma_attrs (may be NULL) |
*/ |
static inline int dma_get_attr(enum dma_attr attr, struct dma_attrs *attrs) |
{ |
if (attrs == NULL) |
return 0; |
BUG_ON(attr >= DMA_ATTR_MAX); |
return test_bit(attr, attrs->flags); |
} |
#else /* !CONFIG_HAVE_DMA_ATTRS */ |
static inline void dma_set_attr(enum dma_attr attr, struct dma_attrs *attrs) |
{ |
} |
|
static inline int dma_get_attr(enum dma_attr attr, struct dma_attrs *attrs) |
{ |
return 0; |
} |
#endif /* CONFIG_HAVE_DMA_ATTRS */ |
#endif /* _DMA_ATTR_H */ |