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Linux kernel mirror (for testing)
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linux
1#ifndef _DMA_ATTR_H
2#define _DMA_ATTR_H
3
4#include <linux/bitmap.h>
5#include <linux/bitops.h>
6#include <linux/bug.h>
7
8/**
9 * an enum dma_attr represents an attribute associated with a DMA
10 * mapping. The semantics of each attribute should be defined in
11 * Documentation/DMA-attributes.txt.
12 */
13enum dma_attr {
14 DMA_ATTR_WRITE_BARRIER,
15 DMA_ATTR_MAX,
16};
17
18#define __DMA_ATTRS_LONGS BITS_TO_LONGS(DMA_ATTR_MAX)
19
20/**
21 * struct dma_attrs - an opaque container for DMA attributes
22 * @flags - bitmask representing a collection of enum dma_attr
23 */
24struct dma_attrs {
25 unsigned long flags[__DMA_ATTRS_LONGS];
26};
27
28#define DEFINE_DMA_ATTRS(x) \
29 struct dma_attrs x = { \
30 .flags = { [0 ... __DMA_ATTRS_LONGS-1] = 0 }, \
31 }
32
33static inline void init_dma_attrs(struct dma_attrs *attrs)
34{
35 bitmap_zero(attrs->flags, __DMA_ATTRS_LONGS);
36}
37
38#ifdef CONFIG_HAVE_DMA_ATTRS
39/**
40 * dma_set_attr - set a specific attribute
41 * @attr: attribute to set
42 * @attrs: struct dma_attrs (may be NULL)
43 */
44static inline void dma_set_attr(enum dma_attr attr, struct dma_attrs *attrs)
45{
46 if (attrs == NULL)
47 return;
48 BUG_ON(attr >= DMA_ATTR_MAX);
49 __set_bit(attr, attrs->flags);
50}
51
52/**
53 * dma_get_attr - check for a specific attribute
54 * @attr: attribute to set
55 * @attrs: struct dma_attrs (may be NULL)
56 */
57static inline int dma_get_attr(enum dma_attr attr, struct dma_attrs *attrs)
58{
59 if (attrs == NULL)
60 return 0;
61 BUG_ON(attr >= DMA_ATTR_MAX);
62 return test_bit(attr, attrs->flags);
63}
64#else /* !CONFIG_HAVE_DMA_ATTRS */
65static inline void dma_set_attr(enum dma_attr attr, struct dma_attrs *attrs)
66{
67}
68
69static inline int dma_get_attr(enum dma_attr attr, struct dma_attrs *attrs)
70{
71 return 0;
72}
73#endif /* CONFIG_HAVE_DMA_ATTRS */
74#endif /* _DMA_ATTR_H */