2012-08-05 05:12:28

by Joe Millenbach

Subject: [PATCH] x86: Changing date reference in CONFIG_SWIOTLB help from a relative to fixed point

CONFIG_SWIOTLB's existing help information refers to "the current
generation of Intel's x86-64 CPUs", but the statement is no longer
true. After researching on Intel's ark site, I changed the statement
to the also true "all Intel CPUs released before 2008".

Signed-off-by: Joe Millenbach <[email protected]>
Reviewed-by: Josh Triplett <[email protected]>
---
arch/x86/Kconfig | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 5bed94e..dadbfd6 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -755,10 +755,10 @@ config SWIOTLB
def_bool y if X86_64
---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.
+ which don't have a hardware IOMMU (e.g. all Intel CPUs released
+ before 2008). 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 IOMMU_HELPER
def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
--
1.7.9.5

2012-08-06 15:01:59

by Konrad Rzeszutek Wilk

Subject: Re: [PATCH] x86: Changing date reference in CONFIG_SWIOTLB help from a relative to fixed point

On Sat, Aug 04, 2012 at 10:12:01PM -0700, Joe Millenbach wrote:
> CONFIG_SWIOTLB's existing help information refers to "the current
> generation of Intel's x86-64 CPUs", but the statement is no longer
> true. After researching on Intel's ark site, I changed the statement
> to the also true "all Intel CPUs released before 2008".
>
> Signed-off-by: Joe Millenbach <[email protected]>
> Reviewed-by: Josh Triplett <[email protected]>
> ---
> arch/x86/Kconfig | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 5bed94e..dadbfd6 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -755,10 +755,10 @@ config SWIOTLB
> def_bool y if X86_64
> ---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.
> + which don't have a hardware IOMMU (e.g. all Intel CPUs released
> + before 2008). 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.

It actually should have that part about Intel CPUs removed - as the hardware
IOMMUs have nothing to do with the CPU. For example the SWIOTLB is used
on the AMD IOMMUs if the IOMMU does not cover certain devices.
So is the case with the IBM Calgary.

>
> config IOMMU_HELPER
> def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
> --
> 1.7.9.5
>
> --
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