Looks like copy and paste from x86 that never actually got used.

Signed-off-by: Christoph Hellwig <h...@lst.de>
---
 arch/ia64/kernel/pci-dma.c | 19 -------------------
 1 file changed, 19 deletions(-)

diff --git a/arch/ia64/kernel/pci-dma.c b/arch/ia64/kernel/pci-dma.c
index b5df084c0af4..50b6ad282a90 100644
--- a/arch/ia64/kernel/pci-dma.c
+++ b/arch/ia64/kernel/pci-dma.c
@@ -18,8 +18,6 @@
 dma_addr_t bad_dma_address __read_mostly;
 EXPORT_SYMBOL(bad_dma_address);
 
-static int iommu_sac_force __read_mostly;
-
 int no_iommu __read_mostly;
 #ifdef CONFIG_IOMMU_DEBUG
 int force_iommu __read_mostly = 1;
@@ -61,23 +59,6 @@ int iommu_dma_supported(struct device *dev, u64 mask)
        if (mask < DMA_BIT_MASK(24))
                return 0;
 
-       /* Tell the device to use SAC when IOMMU force is on.  This
-          allows the driver to use cheaper accesses in some cases.
-
-          Problem with this is that if we overflow the IOMMU area and
-          return DAC as fallback address the device may not handle it
-          correctly.
-
-          As a special case some controllers have a 39bit address
-          mode that is as efficient as 32bit (aic79xx). Don't force
-          SAC for these.  Assume all masks <= 40 bits are of this
-          type. Normally this doesn't make any difference, but gives
-          more gentle handling of IOMMU overflow. */
-       if (iommu_sac_force && (mask >= DMA_BIT_MASK(40))) {
-               dev_info(dev, "Force SAC with mask %llx\n", mask);
-               return 0;
-       }
-
        return 1;
 }
 EXPORT_SYMBOL(iommu_dma_supported);
-- 
2.18.0

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