intel-iommu: Clean up identity mapping code, remove CONFIG_DMAR_GFX_WA

There's no need for the GFX workaround now we have 'iommu=pt' for the
cases where people really care about performance. There's no need to
have a special case for just one type of device.

This also speeds up the iommu=pt path and reduces memory usage by
setting up the si_domain _once_ and then using it for all devices,
rather than giving each device its own private page tables.

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

1 files changed, 2 insertions, 13 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index d1430ef6b4f9..c07f72205909 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1913,25 +1913,14 @@ config DMAR_DEFAULT_ON
           recommended you say N here while the DMAR code remains
           experimental.
 
-config DMAR_GFX_WA
-        def_bool y
-        prompt "Support for Graphics workaround"
-        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.
-
 config DMAR_FLOPPY_WA
         def_bool y
         depends on DMAR
         ---help---
-          Floppy disk drivers are know to bypass DMA API calls
+          Floppy disk drivers are known to bypass DMA API calls
           thereby failing to work when IOMMU is enabled. This
           workaround will setup a 1:1 mapping for the first
-          16M to make floppy (an ISA device) work.
+          16MiB to make floppy (an ISA device) work.
 
 config INTR_REMAP
         bool "Support for Interrupt Remapping (EXPERIMENTAL)"