powerpc/dma: Add optional platform override of dma_set_mask()

Some platforms may want to override dma_set_mask() to take into
account some specific "features" such as the availability of
a direct-map window in addition to an iommu.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

2 files changed, 4 insertions, 13 deletions

diff --git a/arch/powerpc/include/asm/dma-mapping.h b/arch/powerpc/include/asm/dma-mapping.h
index 8c9c6ad2004e..6d2416a85709 100644
--- a/arch/powerpc/include/asm/dma-mapping.h
+++ b/arch/powerpc/include/asm/dma-mapping.h
@@ -127,19 +127,7 @@ static inline int dma_supported(struct device *dev, u64 mask)
 	return dma_ops->dma_supported(dev, mask);
 }
 
-static inline int dma_set_mask(struct device *dev, u64 dma_mask)
-{
-	struct dma_map_ops *dma_ops = get_dma_ops(dev);
-
-	if (unlikely(dma_ops == NULL))
-		return -EIO;
-	if (dma_ops->set_dma_mask != NULL)
-		return dma_ops->set_dma_mask(dev, dma_mask);
-	if (!dev->dma_mask || !dma_supported(dev, dma_mask))
-		return -EIO;
-	*dev->dma_mask = dma_mask;
-	return 0;
-}
+extern int dma_set_mask(struct device *dev, u64 dma_mask);
 
 static inline void *dma_alloc_coherent(struct device *dev, size_t size,
 				       dma_addr_t *dma_handle, gfp_t flag)
diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h
index adc8e6cdf339..d045b0145537 100644
--- a/arch/powerpc/include/asm/machdep.h
+++ b/arch/powerpc/include/asm/machdep.h
@@ -102,6 +102,9 @@ struct machdep_calls {
 	void		(*pci_dma_dev_setup)(struct pci_dev *dev);
 	void		(*pci_dma_bus_setup)(struct pci_bus *bus);
 
+	/* Platform set_dma_mask override */
+	int		(*dma_set_mask)(struct device *dev, u64 dma_mask);
+
 	int		(*probe)(void);
 	void		(*setup_arch)(void); /* Optional, may be NULL */
 	void		(*init_early)(void);