intel-iommu: Restore DMAR_BROKEN_GFX_WA option for broken graphics drivers

We need to give people a little more time to fix the broken drivers.
Re-introduce this, but tied in properly with the 'iommu=pt' support this
time. Change the config option name and make it default to 'no' too.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index c07f72205909..738bdc6b0f8b 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1913,6 +1913,18 @@ config DMAR_DEFAULT_ON
           recommended you say N here while the DMAR code remains
           experimental.
 
+config DMAR_BROKEN_GFX_WA
+        def_bool n
+        prompt "Workaround broken graphics drivers (going away soon)"
+        depends on DMAR
+        ---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, at least until this
+          option is removed in the 2.6.32 kernel.
+
 config DMAR_FLOPPY_WA
         def_bool y
         depends on DMAR