[PATCH 2/9] ia64: remove the dead iommu_sac_force variable

Christoph Hellwig
2018-09-17T17:10:24Z

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

Signed-off-by: Christoph Hellwig <hch@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