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From: Suzuki K Poulose <Suzuki.Poulose@arm.com>
To: Christoffer Dall <christoffer.dall@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org, marc.zyngier@arm.com,
	will.deacon@arm.com, catalin.marinas@arm.com,
	linux-kernel@vger.kernel.org, mark.rutland@arm.com
Subject: Re: [PATCH 2/2] arm64: vhe: Verify CPU Exception Levels
Date: Wed, 13 Apr 2016 12:16:26 +0100	[thread overview]
Message-ID: <570E2A8A.5050504@arm.com> (raw)
In-Reply-To: <20160413111424.GA17696@cbox>

On 13/04/16 12:14, Christoffer Dall wrote:
> On Tue, Apr 12, 2016 at 03:46:01PM +0100, Suzuki K Poulose wrote:
>> With a VHE capable CPU, kernel can run at EL2 and is a decided at early
>> boot. If some of the CPUs didn't start it EL2 or doesn't have VHE, we
>> could have CPUs running at different exception levels, all in the same
>> kernel! This patch adds an early check for the secondary CPUs to detect
>> such situations.
>>
>> For each non-boot CPU add a sanity check to make sure we don't have
>> different run levels w.r.t the boot CPU. We save the information on
>> whether the boot CPU is running in hyp mode or not and ensure the
>> remaining CPUs match it.
>>
>> Applies on 4.6-rc3.

>> +#ifdef CONFIG_ARM64_VHE
>> +
>> +extern bool boot_cpu_hyp_mode;
>> +static inline bool is_boot_cpu_in_hyp_mode(void)
>> +{
>> +	return boot_cpu_hyp_mode;
>> +}
>
> would it make sense to move this to smp.c to avoid exporting
> boot_cpu_hyp_mode?

Sure, we can.

>
> Note that boot_cpu_hyp_mode is never set without CONFIG_SMP, but that
> shouldn't matter I suppose.

Right. The check will be invoked only by the secondary CPUs. I will
respin it.

Cheers
Suzuki

WARNING: multiple messages have this Message-ID (diff)
From: Suzuki.Poulose@arm.com (Suzuki K Poulose)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/2] arm64: vhe: Verify CPU Exception Levels
Date: Wed, 13 Apr 2016 12:16:26 +0100	[thread overview]
Message-ID: <570E2A8A.5050504@arm.com> (raw)
In-Reply-To: <20160413111424.GA17696@cbox>

On 13/04/16 12:14, Christoffer Dall wrote:
> On Tue, Apr 12, 2016 at 03:46:01PM +0100, Suzuki K Poulose wrote:
>> With a VHE capable CPU, kernel can run at EL2 and is a decided at early
>> boot. If some of the CPUs didn't start it EL2 or doesn't have VHE, we
>> could have CPUs running at different exception levels, all in the same
>> kernel! This patch adds an early check for the secondary CPUs to detect
>> such situations.
>>
>> For each non-boot CPU add a sanity check to make sure we don't have
>> different run levels w.r.t the boot CPU. We save the information on
>> whether the boot CPU is running in hyp mode or not and ensure the
>> remaining CPUs match it.
>>
>> Applies on 4.6-rc3.

>> +#ifdef CONFIG_ARM64_VHE
>> +
>> +extern bool boot_cpu_hyp_mode;
>> +static inline bool is_boot_cpu_in_hyp_mode(void)
>> +{
>> +	return boot_cpu_hyp_mode;
>> +}
>
> would it make sense to move this to smp.c to avoid exporting
> boot_cpu_hyp_mode?

Sure, we can.

>
> Note that boot_cpu_hyp_mode is never set without CONFIG_SMP, but that
> shouldn't matter I suppose.

Right. The check will be invoked only by the secondary CPUs. I will
respin it.

Cheers
Suzuki

  reply	other threads:[~2016-04-13 11:16 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-12 14:46 [PATCH 1/2] arm64: Add cpu_panic_kernel helper Suzuki K Poulose
2016-04-12 14:46 ` Suzuki K Poulose
2016-04-12 14:46 ` [PATCH 2/2] arm64: vhe: Verify CPU Exception Levels Suzuki K Poulose
2016-04-12 14:46   ` Suzuki K Poulose
2016-04-13 11:14   ` Christoffer Dall
2016-04-13 11:14     ` Christoffer Dall
2016-04-13 11:16     ` Suzuki K Poulose [this message]
2016-04-13 11:16       ` Suzuki K Poulose
2016-04-13 13:41   ` [PATCH v2 " Suzuki K Poulose
2016-04-13 13:41     ` Suzuki K Poulose
2016-04-14 12:19     ` Christoffer Dall
2016-04-14 12:19       ` Christoffer Dall
2016-04-14 12:54       ` Suzuki K Poulose
2016-04-14 12:54         ` Suzuki K Poulose
2016-04-15 13:55         ` Will Deacon
2016-04-15 13:55           ` Will Deacon

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