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DMA-API: provide a helper to setup DMA masks 

Many drivers contain code such as:

	dev->dma_mask = &dev->coherent_dma_mask;
	dev->coherent_dma_mask = MASK;

Let's move this pattern out of drivers and have the DMA API provide a
helper for it.  This helper uses dma_set_mask_and_coherent() to allow
platform issues to be properly dealt with via dma_set_mask()/
dma_is_supported().

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King 2013-06-27 12:21:45 +01:00
parent 4ffb4318b0
commit fa6a8d6d65
1 changed files with 10 additions and 0 deletions
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10
include/linux/dma-mapping.h
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@ -111,6 +111,16 @@ static inline int dma_set_mask_and_coherent(struct device *dev, u64 mask)
return rc;
}
/*
* Similar to the above, except it deals with the case where the device
* does not have dev->dma_mask appropriately setup.
*/
static inline int dma_coerce_mask_and_coherent(struct device *dev, u64 mask)
{
dev->dma_mask = &dev->coherent_dma_mask;
return dma_set_mask_and_coherent(dev, mask);
}
extern u64 dma_get_required_mask(struct device *dev);
static inline unsigned int dma_get_max_seg_size(struct device *dev)