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74bc7cee AK |
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 | */ | |
13 | enum 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 | */ | |
24 | struct 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 | ||
33 | static 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 | */ | |
44 | static 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 | */ | |
57 | static 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 */ | |
65 | static inline void dma_set_attr(enum dma_attr attr, struct dma_attrs *attrs) | |
66 | { | |
67 | } | |
68 | ||
69 | static 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 */ |