powerpc: Use the newly added get_required_mask dma_map_ops hook

Now that the generic code has dma_map_ops set, instead of having a
messy ifdef & if block in the base dma_get_required_mask hook push
the computation into the dma ops.

If the ops fails to set the get_required_mask hook default to the
width of dma_addr_t.

This also corrects ibmbus ibmebus_dma_supported to require a 64
bit mask.  I doubt anything is checking or setting the dma mask on
that bus.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org
Cc: benh@kernel.crashing.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 7 insertions, 1 deletions

diff --git a/arch/powerpc/kernel/ibmebus.c b/arch/powerpc/kernel/ibmebus.c
index 28581f1ad2c..90ef2a44613 100644
--- a/arch/powerpc/kernel/ibmebus.c
+++ b/arch/powerpc/kernel/ibmebus.c
@@ -125,7 +125,12 @@ static void ibmebus_unmap_sg(struct device *dev,
 
 static int ibmebus_dma_supported(struct device *dev, u64 mask)
 {
-	return 1;
+	return mask == DMA_BIT_MASK(64);
+}
+
+static u64 ibmebus_dma_get_required_mask(struct device *dev)
+{
+	return DMA_BIT_MASK(64);
 }
 
 static struct dma_map_ops ibmebus_dma_ops = {
@@ -134,6 +139,7 @@ static struct dma_map_ops ibmebus_dma_ops = {
 	.map_sg         = ibmebus_map_sg,
 	.unmap_sg       = ibmebus_unmap_sg,
 	.dma_supported  = ibmebus_dma_supported,
+	.get_required_mask  = ibmebus_dma_get_required_mask,
 	.map_page       = ibmebus_map_page,
 	.unmap_page     = ibmebus_unmap_page,
 };