powerpc/dma: Fix check for direct DMA support

The current check is wrong because it does not take the DMA offset intot
account, and in the case of a driver which doesn't actually support
64bits would falsely report that device as working.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c
index f368c075c90b0f6081af5cd60c25bc9edc3f182c..cf02cad62d9a78ecaae14161d7deb6cd78bdf768 100644 (file)
--- a/arch/powerpc/kernel/dma.c
+++ b/arch/powerpc/kernel/dma.c
@@ -90,7 +90,7 @@ static int dma_direct_dma_supported(struct device *dev, u64 mask)
        /* Could be improved so platforms can set the limit in case
         * they have limited DMA windows
         */
-       return mask >= (memblock_end_of_DRAM() - 1);
+       return mask >= get_dma_offset(dev) + (memblock_end_of_DRAM() - 1);
 #else
        return 1;
 #endif