Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1604591 > unrolled thread

Re: [PATCH 03/17] arm64: Allow checking of a CPU-local erratum

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  Re: [PATCH 03/17] arm64: Allow checking of a CPU-local erratum Mark Rutland <mark.rutland@arm.com> - 2017-03-20 15:00 +0100
    Re: [PATCH 03/17] arm64: Allow checking of a CPU-local erratum Suzuki K Poulose <Suzuki.Poulose@arm.com> - 2017-03-20 15:30 +0100

#1604591 — Re: [PATCH 03/17] arm64: Allow checking of a CPU-local erratum

On Mon, Mar 06, 2017 at 11:26:08AM +0000, Marc Zyngier wrote:
> this_cpu_has_cap() only checks the feature array, and not the errata
> one. In order to be able to check for a CPU-local erratum, allow it
> to inspect the latter as well.
> 
> This is consistent with cpus_have_cap()'s behaviour, which includes
> errata already.
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

This sounds sensible to me.

Suzuki, any comments?

Thanks,
Mark.

> ---
>  arch/arm64/kernel/cpufeature.c | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
> index abda8e861865..6eb77ae99b79 100644
> --- a/arch/arm64/kernel/cpufeature.c
> +++ b/arch/arm64/kernel/cpufeature.c
> @@ -1090,20 +1090,29 @@ static void __init setup_feature_capabilities(void)
>   * Check if the current CPU has a given feature capability.
>   * Should be called from non-preemptible context.
>   */
> -bool this_cpu_has_cap(unsigned int cap)
> +static bool __this_cpu_has_cap(const struct arm64_cpu_capabilities *cap_array,
> +			       unsigned int cap)
>  {
>  	const struct arm64_cpu_capabilities *caps;
>  
>  	if (WARN_ON(preemptible()))
>  		return false;
>  
> -	for (caps = arm64_features; caps->desc; caps++)
> +	for (caps = cap_array; caps->desc; caps++)
>  		if (caps->capability == cap && caps->matches)
>  			return caps->matches(caps, SCOPE_LOCAL_CPU);
>  
>  	return false;
>  }
>  
> +extern const struct arm64_cpu_capabilities arm64_errata[];
> +
> +bool this_cpu_has_cap(unsigned int cap)
> +{
> +	return (__this_cpu_has_cap(arm64_features, cap) ||
> +		__this_cpu_has_cap(arm64_errata, cap));
> +}
> +
>  void __init setup_cpu_features(void)
>  {
>  	u32 cwg;
> -- 
> 2.11.0
> 

[toc] | [next] | [standalone]

#1604626

On 20/03/17 13:56, Mark Rutland wrote:
> On Mon, Mar 06, 2017 at 11:26:08AM +0000, Marc Zyngier wrote:
>> this_cpu_has_cap() only checks the feature array, and not the errata
>> one. In order to be able to check for a CPU-local erratum, allow it
>> to inspect the latter as well.
>>
>> This is consistent with cpus_have_cap()'s behaviour, which includes
>> errata already.
>>
>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>
> This sounds sensible to me.
>
> Suzuki, any comments?

Yes, this looks fine to me.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>

>
> Thanks,
> Mark.
>
>> ---
>>  arch/arm64/kernel/cpufeature.c | 13 +++++++++++--
>>  1 file changed, 11 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
>> index abda8e861865..6eb77ae99b79 100644
>> --- a/arch/arm64/kernel/cpufeature.c
>> +++ b/arch/arm64/kernel/cpufeature.c
>> @@ -1090,20 +1090,29 @@ static void __init setup_feature_capabilities(void)
>>   * Check if the current CPU has a given feature capability.
>>   * Should be called from non-preemptible context.
>>   */
>> -bool this_cpu_has_cap(unsigned int cap)
>> +static bool __this_cpu_has_cap(const struct arm64_cpu_capabilities *cap_array,
>> +			       unsigned int cap)
>>  {
>>  	const struct arm64_cpu_capabilities *caps;
>>
>>  	if (WARN_ON(preemptible()))
>>  		return false;
>>
>> -	for (caps = arm64_features; caps->desc; caps++)
>> +	for (caps = cap_array; caps->desc; caps++)
>>  		if (caps->capability == cap && caps->matches)
>>  			return caps->matches(caps, SCOPE_LOCAL_CPU);
>>
>>  	return false;
>>  }
>>
>> +extern const struct arm64_cpu_capabilities arm64_errata[];
>> +
>> +bool this_cpu_has_cap(unsigned int cap)
>> +{
>> +	return (__this_cpu_has_cap(arm64_features, cap) ||
>> +		__this_cpu_has_cap(arm64_errata, cap));
>> +}
>> +
>>  void __init setup_cpu_features(void)
>>  {
>>  	u32 cwg;
>> --
>> 2.11.0
>>

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web