Hi Julien, I agree. You can update the commit message. Thanks for review.
Michal ________________________________ From: Julien Grall <jul...@xen.org> Sent: Wednesday, October 14, 2020 12:56 PM To: Michal Orzel <michal.or...@arm.com>; xen-devel@lists.xenproject.org <xen-devel@lists.xenproject.org> Cc: Stefano Stabellini <sstabell...@kernel.org>; Volodymyr Babchuk <volodymyr_babc...@epam.com>; Bertrand Marquis <bertrand.marq...@arm.com> Subject: Re: [PATCH] xen/arm: Document the erratum #853709 related to Cortex A72 Hi Michal, On 14/10/2020 11:05, Michal Orzel wrote: > Workaround for Cortex-A57 erratum #852523 is already > in Xen but Cortex-A72 erratum #853709 is not although > it applies to the same issue. This commit message is a bit confusing because it implies that Xen doesn't workaround #852523. However, we do workaround it (there is no runtime check) but not document it. So how about the following commit message? "The Cortex-A72 erratum #853709 is the same as the Cortex-A57 erratum #852523. As the latter is already workaround, we only need to update the documentation." > Signed-off-by: Michal Orzel <michal.or...@arm.com> Other than the commit message, I have cross-checked with the documentation ([1]): Reviewed-by: Julien Grall <jgr...@amazon.com> I can update the commit message on commit. Cheers, > --- > docs/misc/arm/silicon-errata.txt | 1 + > xen/arch/arm/domain.c | 6 ++++-- > 2 files changed, 5 insertions(+), 2 deletions(-) > > diff --git a/docs/misc/arm/silicon-errata.txt > b/docs/misc/arm/silicon-errata.txt > index e15d0923e9..1f18a9df58 100644 > --- a/docs/misc/arm/silicon-errata.txt > +++ b/docs/misc/arm/silicon-errata.txt > @@ -50,6 +50,7 @@ stable hypervisors. > | ARM | Cortex-A57 | #834220 | ARM64_ERRATUM_834220 > | > | ARM | Cortex-A57 | #1319537 | N/A > | > | ARM | Cortex-A72 | #1319367 | N/A > | > +| ARM | Cortex-A72 | #853709 | N/A > | > | ARM | Cortex-A76 | #1165522 | N/A > | > | ARM | Neoverse-N1 | #1165522 | N/A > | ARM | MMU-500 | #842869 | N/A > | > diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c > index 3b37f899b9..18cafcdda7 100644 > --- a/xen/arch/arm/domain.c > +++ b/xen/arch/arm/domain.c > @@ -216,7 +216,8 @@ static void ctxt_switch_to(struct vcpu *n) > WRITE_SYSREG64(n->arch.ttbr1, TTBR1_EL1); > > /* > - * Erratum #852523: DACR32_EL2 must be restored before one of the > + * Erratum #852523 (Cortex-A57) or erratum #853709 (Cortex-A72): > + * DACR32_EL2 must be restored before one of the > * following sysregs: SCTLR_EL1, TCR_EL1, TTBR0_EL1, TTBR1_EL1 or > * CONTEXTIDR_EL1. > */ > @@ -245,7 +246,8 @@ static void ctxt_switch_to(struct vcpu *n) > > /* > * This write to sysreg CONTEXTIDR_EL1 ensures we don't hit erratum > - * #852523. I.e DACR32_EL2 is not correctly synchronized. > + * #852523 (Cortex-A57) or #853709 (Cortex-A72). > + * I.e DACR32_EL2 is not correctly synchronized. > */ > WRITE_SYSREG(n->arch.contextidr, CONTEXTIDR_EL1); > WRITE_SYSREG(n->arch.tpidr_el0, TPIDR_EL0); > [1] https://developer.arm.com/documentation/epm012079/11/ -- Julien Grall
