sparc64: Enable 64-bit DMA

ATU 64bit addressing allows PCIe devices with 64bit DMA capabilities
to use ATU for 64bit DMA.

Signed-off-by: Tushar Dave <tushar.n.dave@oracle.com>
Reviewed-by: chris hyser <chris.hyser@oracle.com>
Acked-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 10 insertions, 2 deletions

diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 5202eb4ba2db..60145c9b9f84 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -93,6 +93,10 @@ config ARCH_ATU
         bool
         default y if SPARC64
 
+config ARCH_DMA_ADDR_T_64BIT
+        bool
+        default y if ARCH_ATU
+
 config IOMMU_HELPER
         bool
         default y if SPARC64
diff --git a/arch/sparc/kernel/iommu.c b/arch/sparc/kernel/iommu.c
index 5c615abff030..852a3291db96 100644
--- a/arch/sparc/kernel/iommu.c
+++ b/arch/sparc/kernel/iommu.c
@@ -760,8 +760,12 @@ int dma_supported(struct device *dev, u64 device_mask)
         struct iommu *iommu = dev->archdata.iommu;
         u64 dma_addr_mask = iommu->dma_addr_mask;
 
-        if (device_mask >= (1UL << 32UL))
-                return 0;
+        if (device_mask > DMA_BIT_MASK(32)) {
+                if (iommu->atu)
+                        dma_addr_mask = iommu->atu->dma_addr_mask;
+                else
+                        return 0;
+        }
 
         if ((device_mask & dma_addr_mask) == dma_addr_mask)
                 return 1;