[PATCH] Calgary: allow compiling Calgary in but not using it by default

This patch makes it possible to compile Calgary in but not use it by
default. In this mode, use 'iommu=calgary' to activate it.

Signed-off-by: Muli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
Signed-off-by: Andi Kleen <ak@suse.de>

1 files changed, 11 insertions, 0 deletions

diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index 010d2265f1cf..5cb509dbffe4 100644
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -455,6 +455,17 @@ config CALGARY_IOMMU
           Normally the kernel will make the right choice by itself.
           If unsure, say Y.
 
+config CALGARY_IOMMU_ENABLED_BY_DEFAULT
+        bool "Should Calgary be enabled by default?"
+        default y
+        depends on CALGARY_IOMMU
+        help
+          Should Calgary be enabled by default? if you choose 'y', Calgary
+          will be used (if it exists). If you choose 'n', Calgary will not be
+          used even if it exists. If you choose 'n' and would like to use
+          Calgary anyway, pass 'iommu=calgary' on the kernel command line.
+          If unsure, say Y.
+
 # need this always selected by IOMMU for the VIA workaround
 config SWIOTLB
         bool