dma-mapping: Add get_required_mask if arch overrides default

If an architecture sets ARCH_HAS_DMA_GET_REQUIRED_MASK and has settable dma_map_ops, the required mask may change by the ops implementation. For example, a system that always has an mmu inline may only require 32 bits while a swiotlb would desire bits to cover all of memory. Therefore add the field if the architecture does not use the generic definition of dma_get_required_mask. The first use will by by powerpc. Note that this does add some dependency on the order in which files are visible here. Signed-off-by: Milton Miller <[email protected]> Signed-off-by: Nishanth Aravamudan <[email protected]> Signed-off-by: Benjamin Herrenschmidt <[email protected]> Acked-by: FUJITA Tomonori <[email protected]>
sum-it · Sep 19, 2011 · 3a8f755 · 3a8f755
1 parent 6a5c7be
commit 3a8f755
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
@@ -41,6 +41,9 @@ struct dma_map_ops {
 	int (*mapping_error)(struct device *dev, dma_addr_t dma_addr);
 	int (*dma_supported)(struct device *dev, u64 mask);
 	int (*set_dma_mask)(struct device *dev, u64 mask);
+#ifdef ARCH_HAS_DMA_GET_REQUIRED_MASK
+	u64 (*get_required_mask)(struct device *dev);
+#endif
 	int is_phys;
 };