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