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Date:   Fri, 20 Nov 2020 08:56:31 +0000
From:   Marc Zyngier <maz@kernel.org>
To:     Neeraj Upadhyay <neeraju@codeaurora.org>
Cc:     ionela.voinescu@arm.com, valentin.schneider@arm.com,
        mark.rutland@arm.com, suzuki.poulose@arm.com,
        Will Deacon <will@kernel.org>, catalin.marinas@arm.com,
        linux-arm-kernel@lists.infradead.org,
        lkml <linux-kernel@vger.kernel.org>,
        MSM <linux-arm-msm@vger.kernel.org>
Subject: Re: AMU extension v1 support for cortex A76, A77, A78 CPUs
In-Reply-To: <2cc9dd44-0b4b-94a8-155a-7a2446a1b892@codeaurora.org>
References: <2cc9dd44-0b4b-94a8-155a-7a2446a1b892@codeaurora.org>
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On 2020-11-20 04:30, Neeraj Upadhyay wrote:
> Hi,
> 
> For ARM cortex A76, A77, A78 cores (which as per TRM, support AMU)
> AA64PFR0[47:44] field is not set, and AMU does not get enabled for
> them.
> Can you please provide support for these CPUs in cpufeature.c?

If that was the case, that'd be an erratum, and it would need to be
documented as such. It could also be that this is an optional feature
for these cores (though the TRM doesn't suggest that).

Can someone at ARM confirm what is the expected behaviour of these CPUs?

         M.
-- 
Jazz is not dead. It just smells funny...