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>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index c07f722..738bdc6 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1913,6 +1913,18 @@
 	  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