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 --- include/linux/dma-mapping.h | 10 ++++++++++ 1 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index ec951f9..27d1421 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)