[PATCH] x86_64: Rename IOMMU option, fix help and mark option embedded.
- Rename the GART_IOMMU option to IOMMU to make clear it's not
just for AMD
- Rewrite the help text to better emphatise this fact
- Make it an embedded option because too many people get it wrong.
To my astonishment I discovered the aacraid driver tests this
symbol directly. This looks quite broken to me - it's an internal
implementation detail of the PCI DMA API. Can the maintainer
please clarify what this test was intended to do?
Cc: linux-scsi@vger.kernel.org
Cc: alan@redhat.com
Cc: markh@osdl.org
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index fc75275..e8c52a1 100644
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -386,24 +386,26 @@
bool "Provide RTC interrupt"
depends on HPET_TIMER && RTC=y
-config GART_IOMMU
- bool "K8 GART IOMMU support"
+# Mark as embedded because too many people got it wrong.
+# The code disables itself when not needed.
+config IOMMU
+ bool "IOMMU support" if EMBEDDED
default y
select SWIOTLB
select AGP
depends on PCI
help
- Support for hardware IOMMU in AMD's Opteron/Athlon64 Processors
- and for the bounce buffering software 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
- northbridge and a software emulation used on other systems without
- hardware IOMMU. If unsure, say Y.
+ Support for full DMA access of devices with 32bit memory access only
+ on systems with more than 3GB. This is usually needed for USB,
+ sound, many IDE/SATA chipsets and some other devices.
+ Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
+ based IOMMU and a software bounce buffer based IOMMU used on Intel
+ systems and as fallback.
+ The code is only active when needed (enough memory and limited
+ device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
+ too.
-# need this always selected by GART_IOMMU for the VIA workaround
+# need this always selected by IOMMU for the VIA workaround
config SWIOTLB
bool
@@ -503,7 +505,7 @@
config K8_NB
def_bool y
- depends on AGP_AMD64 || GART_IOMMU || (PCI && NUMA)
+ depends on AGP_AMD64 || IOMMU || (PCI && NUMA)
endmenu