From: Will Deacon <will@kernel.org>
To: Marc Zyngier <maz@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>,
kernel-team@android.com, linux-arm-kernel@lists.infradead.org,
Doug Anderson <dianders@google.com>
Subject: Re: [PATCH] arm64: Allow CPUs unffected by ARM erratum 1418040 to come in late
Date: Fri, 11 Sep 2020 19:31:58 +0100 [thread overview]
Message-ID: <20200911183157.GA21405@willie-the-truck> (raw)
In-Reply-To: <20200911181611.2073183-1-maz@kernel.org>
On Fri, Sep 11, 2020 at 07:16:11PM +0100, Marc Zyngier wrote:
> Now that we allow CPUs affected by erratum 1418040 to come in late,
> this prevents their unaffected sibblings from coming in late (or
> coming back after a suspend or hotplug-off, which amounts to the
> same thing).
>
> To allow this, we need to add ARM64_CPUCAP_OPTIONAL_FOR_LATE_CPU,
> which amounts to set .type to ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE.
>
> Reported-by: Doug Anderson <dianders@google.com>
> Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
> Fixes: bf87bb0881d0 ("arm64: Allow booting of late CPUs affected by erratum 1418040")
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> arch/arm64/kernel/cpu_errata.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
> index c332d49780dc..560ba69e13c1 100644
> --- a/arch/arm64/kernel/cpu_errata.c
> +++ b/arch/arm64/kernel/cpu_errata.c
> @@ -910,8 +910,12 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
> .desc = "ARM erratum 1418040",
> .capability = ARM64_WORKAROUND_1418040,
> ERRATA_MIDR_RANGE_LIST(erratum_1418040_list),
> - .type = (ARM64_CPUCAP_SCOPE_LOCAL_CPU |
> - ARM64_CPUCAP_PERMITTED_FOR_LATE_CPU),
> + /*
> + * We need to allow affected CPUs to come in late, but
> + * also need the non-affected CPUs to be able to come
> + * in at any point in time. Wonderful.
> + */
> + .type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
Acked-by: Will Deacon <will@kernel.org>
Will
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next prev parent reply other threads:[~2020-09-11 18:33 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-11 18:16 [PATCH] arm64: Allow CPUs unffected by ARM erratum 1418040 to come in late Marc Zyngier
2020-09-11 18:31 ` Will Deacon [this message]
2020-09-11 18:59 ` Matthias Kaehlcke
2020-09-11 19:51 ` Doug Anderson
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