ia64: remove the dead iommu_sac_force variable

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

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
This commit is contained in:
Christoph Hellwig 2018-09-17 19:10:24 +02:00 committed by Tony Luck
parent b501fb9227
commit 77308e27a0

View File

@ -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);