On Wed, Nov 06, 2019 at 01:11:30PM +0800, Lu Baolu wrote:
This adds a Kconfig option INTEL_IOMMU_SCALABLE_MODE_ON to make
it easier for distributions to enable or disable the Intel IOMMU
scalable mode during kernel build.
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
drivers/iommu/Kconfig | 10 ++++++++++
drivers/iommu/intel-iommu.c | 5 +++++
2 files changed, 15 insertions(+)
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index e3842eabcfdd..32f30e27791c 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -242,6 +242,16 @@ config INTEL_IOMMU_FLOPPY_WA
workaround will setup a 1:1 mapping for the first
16MiB to make floppy (an ISA device) work.
+config INTEL_IOMMU_SCALABLE_MODE_ON
That should have a DEFAULT in the name as it is a default.
+ def_bool n
n is the default default, so this can just be bool.
+#ifdef CONFIG_INTEL_IOMMU_SCALABLE_MODE_ON
+int intel_iommu_sm = 1;
+#else
int intel_iommu_sm;
+#endif /* CONFIG_INTEL_IOMMU_SCALABLE_MODE_ON */
This can use IS_ENABLED().
But then again the distro can just add iommu=sm_on to CONFIG_CMDLINE
and have the same effect, so I don't really get the point of the whole
patch.
Or why we can't just enable it by default for that matter.