[PATCH v3 6/6] sparc64: Enable 64-bit DMA

[Tushar Dave]

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

Signed-off-by: Tushar Dave <tushar.n.d...@oracle.com>
Reviewed-by: chris hyser <chris.hy...@oracle.com>
Acked-by: Sowmini Varadhan <sowmini.varad...@oracle.com>
---
 arch/sparc/Kconfig        | 4 ++++
 arch/sparc/kernel/iommu.c | 8 ++++++--
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 5202eb4..60145c9 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 5c615ab..852a329 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;
-- 
1.9.1