diff options
| author | Karsten Weiss <K.Weiss@science-computing.de> | 2007-02-13 13:26:21 +0100 |
|---|---|---|
| committer | Andi Kleen <andi@basil.nowhere.org> | 2007-02-13 13:26:21 +0100 |
| commit | 5558870bfbcca10cfc7b13ab866687012ea3c9af (patch) | |
| tree | 45605429a4fd5eee9b05d5e7c852fa72bfd07a21 /arch/x86_64/Kconfig | |
| parent | 5809f9d442e9dbb23859e2c37d8c47043f6b5cc9 (diff) | |
[PATCH] x86-64: improved iommu documentation
- add SWIOTLB config help text
- mention Documentation/x86_64/boot-options.txt in
Documentation/kernel-parameters.txt
- remove the duplication of the iommu kernel parameter documentation.
- Better explanation of some of the iommu kernel parameter options.
- "32MB<<order" instead of "32MB^order".
- Mention the default "order" value.
- list the four existing PCI-DMA mapping implementations of arch x86_64
- group the iommu= option keywords by PCI-DMA mapping implementation.
- Distinguish iommu= option keywords from number arguments.
- Explain the meaning of DAC and SAC.
Signed-off-by: Karsten Weiss <knweiss@science-computing.de>
Signed-off-by: Andi Kleen <ak@suse.de>
Acked-by: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Diffstat (limited to 'arch/x86_64/Kconfig')
| -rw-r--r-- | arch/x86_64/Kconfig | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig index 02dd39457bcf..a55382a1bb46 100644 --- a/arch/x86_64/Kconfig +++ b/arch/x86_64/Kconfig @@ -458,8 +458,8 @@ config IOMMU 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. + based hardware 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. @@ -496,6 +496,12 @@ config CALGARY_IOMMU_ENABLED_BY_DEFAULT # need this always selected by IOMMU for the VIA workaround config SWIOTLB bool + help + Support for software bounce buffers used on x86-64 systems + which don't have a hardware IOMMU (e.g. the current generation + of Intel's x86-64 CPUs). Using this PCI devices which can only + access 32-bits of memory can be used on systems with more than + 3 GB of memory. If unsure, say Y. config X86_MCE bool "Machine check support" if EMBEDDED |