72 lines
1.6 KiB
C
72 lines
1.6 KiB
C
#ifndef _DMA_ATTR_H
|
|
#define _DMA_ATTR_H
|
|
|
|
#include <linux/bitmap.h>
|
|
#include <linux/bitops.h>
|
|
#include <linux/bug.h>
|
|
|
|
/**
|
|
* 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_ALLOC_SINGLE_PAGES,
|
|
DMA_ATTR_MAX,
|
|
};
|
|
|
|
#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];
|
|
};
|
|
|
|
#define DEFINE_DMA_ATTRS(x) \
|
|
struct dma_attrs x = { \
|
|
.flags = { [0 ... __DMA_ATTRS_LONGS-1] = 0 }, \
|
|
}
|
|
|
|
static inline void init_dma_attrs(struct dma_attrs *attrs)
|
|
{
|
|
bitmap_zero(attrs->flags, __DMA_ATTRS_LONGS);
|
|
}
|
|
|
|
/**
|
|
* 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);
|
|
}
|
|
|
|
#endif /* _DMA_ATTR_H */
|