Intel IOMMU: Iommu Gfx workaround

[deliverable/linux.git] / arch / x86_64 / Kconfig

diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index 5c9aaed589a5416de030619d7c6a5a5ce0152a3c..5cf941774347fb02c2dbb34d148abbe96fca313e 100644 (file)
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -755,11 +755,22 @@ config DMAR
        depends on PCI_MSI && ACPI && EXPERIMENTAL
        default y
        help
-         DMA remapping(DMAR) devices support enables independent address
-         translations for Direct Memory Access(DMA) from Devices.
+         DMA remapping (DMAR) devices support enables independent address
+         translations for Direct Memory Access (DMA) from devices.
          These DMA remapping devices are reported via ACPI tables
-         and includes pci device scope covered by these DMA
-         remapping device.
+         and include PCI device scope covered by these DMA
+         remapping devices.
+
+config DMAR_GFX_WA
+       bool "Support for Graphics workaround"
+       depends on DMAR
+       default y
+       help
+        Current Graphics drivers tend to use physical address
+        for DMA and avoid using DMA APIs. Setting this config
+        option permits the IOMMU driver to set a unity map for
+        all the OS-visible memory. Hence the driver can continue
+        to use physical addresses for DMA.
 
 source "drivers/pci/pcie/Kconfig"