Messages in this thread | | | Date | Wed, 24 Feb 2016 13:40:16 +0000 | From | Will Deacon <> | Subject | Re: [PATCH v3] arm64: Add workaround for Cavium erratum 27456 |
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On Tue, Feb 23, 2016 at 04:08:54PM -0800, David Daney wrote: > From: Andrew Pinski <apinski@cavium.com> > > On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI > instructions may cause the icache to become corrupted if it contains > data for a non-current ASID. > > This patch implements the workaround (which flushes the local icache > when switching the mm) by using code patching. > > Signed-off-by: Andrew Pinski <apinski@cavium.com> > Signed-off-by: David Daney <david.daney@cavium.com> > --- > Documentation/arm64/silicon-errata.txt | 1 + > arch/arm64/Kconfig | 11 +++++++++++ > arch/arm64/include/asm/cpufeature.h | 3 ++- > arch/arm64/kernel/cpu_errata.c | 9 +++++++++ > arch/arm64/mm/proc.S | 12 ++++++++++++ > 5 files changed, 35 insertions(+), 1 deletion(-) > > diff --git a/Documentation/arm64/silicon-errata.txt b/Documentation/arm64/silicon-errata.txt > index 58b71dd..ba4b6ac 100644 > --- a/Documentation/arm64/silicon-errata.txt > +++ b/Documentation/arm64/silicon-errata.txt > @@ -56,3 +56,4 @@ stable kernels. > | | | | | > | Cavium | ThunderX ITS | #22375, #24313 | CAVIUM_ERRATUM_22375 | > | Cavium | ThunderX GICv3 | #23154 | CAVIUM_ERRATUM_23154 | > +| Cavium | ThunderX Core | #27456 | CAVIUM_ERRATUM_27456 | > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 8cc6228..39f2203 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -432,6 +432,17 @@ config CAVIUM_ERRATUM_23154 > > If unsure, say Y. > > +config CAVIUM_ERRATUM_27456 > + bool "Cavium erratum 27456: Broadcast TLBI instructions may cause the icache corruption"
Doesn't really make sense. Maybe just drop the "the"?
> + default y > + help > + On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI > + instructions may cause the icache to become corrupted if it > + contains data for a non-current ASID. The fix is to flush > + the icache when changing the mm context.
s/flush/invalidate/
Anyway, the rest of the patch looks fine. I still don't have a good idea as to whether or not KVM is affected by this, but I guess that's your problem, so:
Reviewed-by: Will Deacon <will.deacon@arm.com>
(and Catalin, if you pick this up, watch out for the conflicts in cpufeature.h)
Will
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