[PATCH] x86_64: Improve CONFIG_GART_IOMMU description and make it default y
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index 4b83261..660a03a 100644
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -329,12 +329,15 @@
config GART_IOMMU
bool "IOMMU support"
+ default y
depends on PCI
help
- Support the K8 IOMMU. Needed to run systems with more than 4GB of memory
+ Support the IOMMU. Needed to run systems with more than 3GB of memory
properly with 32-bit PCI devices that do not support DAC (Double Address
Cycle). The IOMMU can be turned off at runtime with the iommu=off parameter.
Normally the kernel will take the right choice by itself.
+ This option includes a driver for the AMD Opteron/Athlon64 IOMMU
+ and a software emulation used on some other systems.
If unsure, say Y.
# need this always enabled with GART_IOMMU for the VIA workaround