From fa6a8d6d65b19ab44e5244ea499bcd553cc72343 Mon Sep 17 00:00:00 2001 From: Russell King Date: Thu, 27 Jun 2013 12:21:45 +0100 Subject: 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 --- include/linux/dma-mapping.h | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index ec951f98e3d9..27d1421ad42c 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -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) -- cgit v1.2.3