From: Catalin Marinas <catalin.marinas@arm.com>
To: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org,
Marc Zyngier <maz@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Peter Zijlstra <peterz@infradead.org>,
Morten Rasmussen <morten.rasmussen@arm.com>,
Qais Yousef <qais.yousef@arm.com>,
Suren Baghdasaryan <surenb@google.com>,
kernel-team@android.com
Subject: Re: [PATCH 2/6] arm64: Allow mismatched 32-bit EL0 support
Date: Wed, 28 Oct 2020 11:22:06 +0000 [thread overview]
Message-ID: <20201028112206.GD13345@gaia> (raw)
In-Reply-To: <20201028111713.GA27927@willie-the-truck>
On Wed, Oct 28, 2020 at 11:17:13AM +0000, Will Deacon wrote:
> On Wed, Oct 28, 2020 at 11:12:04AM +0000, Catalin Marinas wrote:
> > On Tue, Oct 27, 2020 at 09:51:14PM +0000, Will Deacon wrote:
> > > +static bool has_32bit_el0(const struct arm64_cpu_capabilities *entry, int scope)
> > > +{
> > > + return has_cpuid_feature(entry, scope) || __allow_mismatched_32bit_el0;
> > > +}
> > > +
> > > static bool has_useable_gicv3_cpuif(const struct arm64_cpu_capabilities *entry, int scope)
> > > {
> > > bool has_sre;
> > > @@ -1803,7 +1851,7 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
> > > .desc = "32-bit EL0 Support",
> > > .capability = ARM64_HAS_32BIT_EL0,
> > > .type = ARM64_CPUCAP_SYSTEM_FEATURE,
> > > - .matches = has_cpuid_feature,
> > > + .matches = has_32bit_el0,
> >
> > Ah, so this one reports 32-bit EL0 support even if no CPU actually
> > supports 32-bit (passing the command line option on TX2 would come up
> > with 32-bit EL0 in dmesg). I'd rather hide the .desc above and print the
> > information elsewhere when have at least one CPU supporting this.
>
> Yeah, the problem is if a CPU with 32-bit EL0 support was late-onlined,
> then we would have 32-bit support, so I think this is an oddity that you
> get when the command line is passed. That said, I could nobble .desc and
> print it from the .matches function, with a slightly different message
> when the command line is passed.
I think we could do a pr_info_once() in update_32bit_cpu_features().
--
Catalin
next prev parent reply other threads:[~2020-10-29 0:59 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-27 21:51 [PATCH 0/6] An alternative series for asymmetric AArch32 systems Will Deacon
2020-10-27 21:51 ` [PATCH 1/6] KVM: arm64: Handle Asymmetric " Will Deacon
2020-10-27 21:51 ` [PATCH 2/6] arm64: Allow mismatched 32-bit EL0 support Will Deacon
2020-10-28 11:12 ` Catalin Marinas
2020-10-28 11:17 ` Will Deacon
2020-10-28 11:22 ` Catalin Marinas [this message]
2020-10-28 11:23 ` Will Deacon
2020-10-28 11:49 ` Catalin Marinas
2020-10-28 12:40 ` Will Deacon
2020-10-28 18:56 ` Catalin Marinas
2020-10-29 22:20 ` Will Deacon
2020-10-30 11:18 ` Catalin Marinas
2020-10-30 16:13 ` Will Deacon
2020-11-02 11:44 ` Catalin Marinas
2020-11-05 21:38 ` Will Deacon
2020-11-06 12:54 ` Qais Yousef
2020-11-06 13:00 ` Will Deacon
2020-11-06 14:48 ` Qais Yousef
2020-11-09 13:52 ` Will Deacon
2020-11-11 16:27 ` Qais Yousef
2020-11-12 10:24 ` Will Deacon
2020-11-12 11:55 ` Qais Yousef
2020-11-12 16:49 ` Qais Yousef
2020-11-12 17:06 ` Marc Zyngier
2020-11-12 17:36 ` Qais Yousef
2020-11-12 17:44 ` Will Deacon
2020-11-12 17:36 ` Will Deacon
2020-11-13 10:45 ` Qais Yousef
2020-11-06 14:30 ` Catalin Marinas
2020-10-28 11:18 ` Catalin Marinas
2020-10-28 11:21 ` Will Deacon
2020-10-27 21:51 ` [PATCH 3/6] KVM: arm64: Kill 32-bit vCPUs on systems with mismatched " Will Deacon
2020-10-27 21:51 ` [PATCH 4/6] arm64: Kill 32-bit applications scheduled on 64-bit-only CPUs Will Deacon
2020-10-28 12:10 ` Catalin Marinas
2020-10-28 12:36 ` Will Deacon
2020-10-27 21:51 ` [PATCH 5/6] arm64: Advertise CPUs capable of running 32-bit applcations in sysfs Will Deacon
2020-10-28 8:37 ` Greg Kroah-Hartman
2020-10-28 9:51 ` Will Deacon
2020-10-28 12:15 ` Catalin Marinas
2020-10-28 12:27 ` Will Deacon
2020-10-28 15:14 ` Catalin Marinas
2020-10-28 15:35 ` Will Deacon
2020-10-27 21:51 ` [PATCH 6/6] arm64: Hook up cmdline parameter to allow mismatched 32-bit EL0 Will Deacon
2020-10-29 18:42 ` [PATCH 0/6] An alternative series for asymmetric AArch32 systems Suren Baghdasaryan
2020-10-29 22:17 ` Will Deacon
2020-10-30 16:16 ` Marc Zyngier
2020-10-30 16:24 ` Will Deacon
2020-10-30 17:04 ` Marc Zyngier
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