ia64: remove the dead iommu_sac_force variable (77308e27) · Commits · 戴 / test

arch/ia64/kernel/pci-dma.c

+0 −19

Original line number	Diff line number	Diff line
		@@ -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);