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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, | |
1ed6af73 | 15 | DMA_ATTR_WEAK_ORDERING, |
8a413432 | 16 | DMA_ATTR_WRITE_COMBINE, |
64d70fe5 | 17 | DMA_ATTR_NON_CONSISTENT, |
d5724f17 | 18 | DMA_ATTR_NO_KERNEL_MAPPING, |
74bc7cee AK |
19 | DMA_ATTR_MAX, |
20 | }; | |
21 | ||
22 | #define __DMA_ATTRS_LONGS BITS_TO_LONGS(DMA_ATTR_MAX) | |
23 | ||
24 | /** | |
25 | * struct dma_attrs - an opaque container for DMA attributes | |
26 | * @flags - bitmask representing a collection of enum dma_attr | |
27 | */ | |
28 | struct dma_attrs { | |
29 | unsigned long flags[__DMA_ATTRS_LONGS]; | |
30 | }; | |
31 | ||
32 | #define DEFINE_DMA_ATTRS(x) \ | |
33 | struct dma_attrs x = { \ | |
34 | .flags = { [0 ... __DMA_ATTRS_LONGS-1] = 0 }, \ | |
35 | } | |
36 | ||
37 | static inline void init_dma_attrs(struct dma_attrs *attrs) | |
38 | { | |
39 | bitmap_zero(attrs->flags, __DMA_ATTRS_LONGS); | |
40 | } | |
41 | ||
42 | #ifdef CONFIG_HAVE_DMA_ATTRS | |
43 | /** | |
44 | * dma_set_attr - set a specific attribute | |
45 | * @attr: attribute to set | |
46 | * @attrs: struct dma_attrs (may be NULL) | |
47 | */ | |
48 | static inline void dma_set_attr(enum dma_attr attr, struct dma_attrs *attrs) | |
49 | { | |
50 | if (attrs == NULL) | |
51 | return; | |
52 | BUG_ON(attr >= DMA_ATTR_MAX); | |
53 | __set_bit(attr, attrs->flags); | |
54 | } | |
55 | ||
56 | /** | |
57 | * dma_get_attr - check for a specific attribute | |
58 | * @attr: attribute to set | |
59 | * @attrs: struct dma_attrs (may be NULL) | |
60 | */ | |
61 | static inline int dma_get_attr(enum dma_attr attr, struct dma_attrs *attrs) | |
62 | { | |
63 | if (attrs == NULL) | |
64 | return 0; | |
65 | BUG_ON(attr >= DMA_ATTR_MAX); | |
66 | return test_bit(attr, attrs->flags); | |
67 | } | |
68 | #else /* !CONFIG_HAVE_DMA_ATTRS */ | |
69 | static inline void dma_set_attr(enum dma_attr attr, struct dma_attrs *attrs) | |
70 | { | |
71 | } | |
72 | ||
73 | static inline int dma_get_attr(enum dma_attr attr, struct dma_attrs *attrs) | |
74 | { | |
75 | return 0; | |
76 | } | |
77 | #endif /* CONFIG_HAVE_DMA_ATTRS */ | |
78 | #endif /* _DMA_ATTR_H */ |