linux-kernel - Re: [RFC PATCH 1/4] cpufreq: acpi-cpufreq: Re-factor overriding ACPI PSD

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Message-ID: <87y2i7oox1.fsf@stealth>
Date:   Wed, 09 Dec 2020 08:31:38 +0900
From:   Punit Agrawal <punitagrawal@...il.com>
To:     Wei Huang <whuang2@....com>
Cc:     rjw@...ysocki.net, wei.huang2@....com,
        linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
        bp@...en8.de, x86@...nel.org
Subject: Re: [RFC PATCH 1/4] cpufreq: acpi-cpufreq: Re-factor overriding
 ACPI PSD

Hi Wei,

Wei Huang <whuang2@....com> writes:

> On 11/25/20 8:48 AM, Punit Agrawal wrote:
>> Re-factor the code to override the firmware provided frequency domain
>> information (via PSD) to localise the checks in one function.
>> 
>> No functional change intended.
>> 
>> Signed-off-by: Punit Agrawal <punitagrawal@...il.com>
>> Cc: Wei Huang <wei.huang2@....com>
>> ---
>>  drivers/cpufreq/acpi-cpufreq.c | 17 +++++++++++++++--
>>  1 file changed, 15 insertions(+), 2 deletions(-)
>> 
>> diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
>> index 1e4fbb002a31..b1e7df96d428 100644
>> --- a/drivers/cpufreq/acpi-cpufreq.c
>> +++ b/drivers/cpufreq/acpi-cpufreq.c
>> @@ -191,6 +191,20 @@ static int check_amd_hwpstate_cpu(unsigned int cpuid)
>>  	return cpu_has(cpu, X86_FEATURE_HW_PSTATE);
>>  }
>>  
>> +static int override_acpi_psd(unsigned int cpu_id)
>          ^^^^^
> int is fine, but it might be better to use bool. Otherwise I don't see
> any issues with this patch.

Makes sense - I will switch to a boolean in the next update.

Thanks for taking a look.

Punit

>
>> +{
>> +	struct cpuinfo_x86 *c = &boot_cpu_data;
>> +
>> +	if (c->x86_vendor == X86_VENDOR_AMD) {
>> +		if (!check_amd_hwpstate_cpu(cpu_id))
>> +			return false;
>> +
>> +		return c->x86 < 0x19;
>> +	}
>> +
>> +	return false;
>> +}
>> +
>>  static unsigned extract_io(struct cpufreq_policy *policy, u32 value)
>>  {
>>  	struct acpi_cpufreq_data *data = policy->driver_data;
>> @@ -691,8 +705,7 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
>>  		cpumask_copy(policy->cpus, topology_core_cpumask(cpu));
>>  	}
>>  
>> -	if (check_amd_hwpstate_cpu(cpu) && boot_cpu_data.x86 < 0x19 &&
>> -	    !acpi_pstate_strict) {
>> +	if (override_acpi_psd(cpu) && !acpi_pstate_strict) {
>>  		cpumask_clear(policy->cpus);
>>  		cpumask_set_cpu(cpu, policy->cpus);
>>  		cpumask_copy(data->freqdomain_cpus,
>>