[Skiboot] [PATCH] phb: Work around XSL bug sending PTE updates with wrong scope

Stewart Smith stewart at linux.vnet.ibm.com
Thu Jun 9 15:50:14 AEST 2016

Ian Munsie <imunsie at au1.ibm.com> writes:
> From: Ian Munsie <imunsie at au1.ibm.com>
> The XSL incorrectly sends out PTE updates with nodal scope instead of
> group scope, which causes a system checkstop. This is exacerbated by the
> fact that recent Linux kernels do not set the R bit in the hashed page
> tables, requiring the XSL to write them back to set that bit. Work
> around this issue by forcing all commands to be unlimited scope.
> This might have a slight performance impact, but it is expected to be
> negligible since the XSL is only used for translations, not for block
> data transfers. To avoid impacting other cards, tie it off the use of
> DMA mode, as only the XSL based Mellanox CX4 card uses this mode and is
> affected.
> Signed-off-by: Ian Munsie <imunsie at au1.ibm.com>
> ---
> Note that this patch depends on '[2/2] phb3: Add support for CAPP DMA mode':
> http://patchwork.ozlabs.org/patch/625582/

Thanks, merged to master as of b99aa9b753fcdc20a88a5728ebdbf3811ee5e455.

Stewart Smith
OPAL Architect, IBM.

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