From: Mark Rutland <mark.rutland@arm.com>
To: Robin Murphy <robin.murphy@arm.com>
Cc: Al Stone <ahs3@redhat.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>
Subject: Re: [PATCH 3/3] arm64: cpuinfo: display product info in /proc/cpuinfo
Date: Wed, 27 Sep 2017 14:39:32 +0100 [thread overview]
Message-ID: <20170927133931.GH32150@leverpostej> (raw)
In-Reply-To: <f09e55d8-28ba-30e3-d58a-ad125fd73019@arm.com>
Hi,
On Wed, Sep 27, 2017 at 11:42:07AM +0100, Robin Murphy wrote:
> On 26/09/17 23:23, Al Stone wrote:
> > + seq_printf(m, ", ARM 8.%d (r%dp%d) CPU",
> > + MIDR_VARIANT(midr),
> > + MIDR_VARIANT(midr),
> > + MIDR_REVISION(midr));
>
> What is "ARM 8.1" meant to infer for, say, a typical Cortex-A57?
Just to make Robin's point a little clearer, MIDR_EL1.Variant is
IMPLEMENTATION DEFINED, and doesn't describe the ARMv8.x architecture
revision.
For example, on Cortex A57 is contains the major revision number of the
CPU, and is 1 for any r1pY Cortex-A57 (e.g. those on Juno R1).
For better or worse, the architecture provides us no mechanism to
determine the architecture revision.
Thanks,
Mark.
next prev parent reply other threads:[~2017-09-27 13:41 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-26 22:23 [PATCH 0/3] arm64: cpuinfo: make /proc/cpuinfo more human-readable Al Stone
2017-09-26 22:23 ` [PATCH 1/3] arm64: cpuinfo: add MPIDR value to /proc/cpuinfo Al Stone
2017-09-27 11:33 ` Mark Rutland
2017-09-26 22:23 ` [PATCH 2/3] arm64: cpuinfo: add human readable CPU names " Al Stone
2017-09-27 10:35 ` Robin Murphy
2017-09-27 11:26 ` Mark Rutland
2017-10-13 14:16 ` Timur Tabi
2017-09-26 22:23 ` [PATCH 3/3] arm64: cpuinfo: display product info in /proc/cpuinfo Al Stone
2017-09-27 0:40 ` Florian Fainelli
2017-09-27 10:42 ` Robin Murphy
2017-09-27 13:39 ` Mark Rutland [this message]
2017-09-27 11:36 ` Mark Rutland
2017-10-13 19:27 ` Timur Tabi
2017-09-27 10:34 ` [PATCH 0/3] arm64: cpuinfo: make /proc/cpuinfo more human-readable Mark Rutland
2017-10-09 22:46 ` Al Stone
2017-10-13 13:39 ` Timur Tabi
2017-10-13 14:27 ` Mark Rutland
2017-10-16 23:43 ` Al Stone
2017-10-20 16:10 ` Mark Rutland
2017-10-20 17:24 ` Jon Masters
2017-10-21 0:50 ` Jon Masters
2017-10-20 23:26 ` Al Stone
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