Add function cppc_get_highest_perf in generic CPPC driver to get the
highest perf register value for specified core.

Signed-off-by: Tony W Wang-oc <TonyWWang-oc@zhaoxin.com>
---
 drivers/acpi/cppc_acpi.c | 13 +++++++++++++
 include/acpi/cppc_acpi.h |  5 +++++
 2 files changed, 18 insertions(+)

diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 7ff269a78c20..1a77c514d007 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -1154,6 +1154,19 @@ int cppc_get_nominal_perf(int cpunum, u64 *nominal_perf)
 	return cppc_get_perf(cpunum, NOMINAL_PERF, nominal_perf);
 }
 
+/**
+ * cppc_get_highest_perf - Get the highest performance register value.
+ * @cpunum: CPU from which to get highest performance.
+ * @highest_perf: Return address.
+ *
+ * Return: 0 for success, -EIO otherwise.
+ */
+int cppc_get_highest_perf(int cpunum, u64 *highest_perf)
+{
+	return cppc_get_perf(cpunum, HIGHEST_PERF, highest_perf);
+}
+EXPORT_SYMBOL_GPL(cppc_get_highest_perf);
+
 /**
  * cppc_get_epp_perf - Get the epp register value.
  * @cpunum: CPU from which to get epp preference value.
diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h
index 6126c977ece0..c0b69ffe7bdb 100644
--- a/include/acpi/cppc_acpi.h
+++ b/include/acpi/cppc_acpi.h
@@ -139,6 +139,7 @@ struct cppc_cpudata {
 #ifdef CONFIG_ACPI_CPPC_LIB
 extern int cppc_get_desired_perf(int cpunum, u64 *desired_perf);
 extern int cppc_get_nominal_perf(int cpunum, u64 *nominal_perf);
+extern int cppc_get_highest_perf(int cpunum, u64 *highest_perf);
 extern int cppc_get_perf_ctrs(int cpu, struct cppc_perf_fb_ctrs *perf_fb_ctrs);
 extern int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls);
 extern int cppc_set_enable(int cpu, bool enable);
@@ -165,6 +166,10 @@ static inline int cppc_get_nominal_perf(int cpunum, u64 *nominal_perf)
 {
 	return -ENOTSUPP;
 }
+static inline int cppc_get_highest_perf(int cpunum, u64 *highest_perf)
+{
+	return -ENOTSUPP;
+}
 static inline int cppc_get_perf_ctrs(int cpu, struct cppc_perf_fb_ctrs *perf_fb_ctrs)
 {
 	return -ENOTSUPP;
-- 
2.25.1

On Thu, Dec 28, 2023 at 03:57:03PM +0800, Tony W Wang-oc wrote:
> Add function cppc_get_highest_perf in generic CPPC driver to get the
> highest perf register value for specified core.
> 
> Signed-off-by: Tony W Wang-oc <TonyWWang-oc@zhaoxin.com>
> ---
>  drivers/acpi/cppc_acpi.c | 13 +++++++++++++
>  include/acpi/cppc_acpi.h |  5 +++++
>  2 files changed, 18 insertions(+)
> 
> diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
> index 7ff269a78c20..1a77c514d007 100644
> --- a/drivers/acpi/cppc_acpi.c
> +++ b/drivers/acpi/cppc_acpi.c
> @@ -1154,6 +1154,19 @@ int cppc_get_nominal_perf(int cpunum, u64 *nominal_perf)
>  	return cppc_get_perf(cpunum, NOMINAL_PERF, nominal_perf);
>  }
>  
> +/**
> + * cppc_get_highest_perf - Get the highest performance register value.
> + * @cpunum: CPU from which to get highest performance.
> + * @highest_perf: Return address.
> + *
> + * Return: 0 for success, -EIO otherwise.
> + */
> +int cppc_get_highest_perf(int cpunum, u64 *highest_perf)
> +{
> +	return cppc_get_perf(cpunum, HIGHEST_PERF, highest_perf);
> +}
> +EXPORT_SYMBOL_GPL(cppc_get_highest_perf);

The Intel P-State driver uses cppc_get_perf_caps(). You would not need to
export this function.

Having said that, the Intel P-State driver could also use this new
function, IMO. AFAICS, it does not *have* to use cppc_get_perf_caps().

On 2024/1/18 06:07, Ricardo Neri wrote:
>
> [这封邮件来自外部发件人]
>
> On Thu, Dec 28, 2023 at 03:57:03PM +0800, Tony W Wang-oc wrote:
>> Add function cppc_get_highest_perf in generic CPPC driver to get the
>> highest perf register value for specified core.
>>
>> Signed-off-by: Tony W Wang-oc <TonyWWang-oc@zhaoxin.com>
>> ---
>>   drivers/acpi/cppc_acpi.c | 13 +++++++++++++
>>   include/acpi/cppc_acpi.h |  5 +++++
>>   2 files changed, 18 insertions(+)
>>
>> diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
>> index 7ff269a78c20..1a77c514d007 100644
>> --- a/drivers/acpi/cppc_acpi.c
>> +++ b/drivers/acpi/cppc_acpi.c
>> @@ -1154,6 +1154,19 @@ int cppc_get_nominal_perf(int cpunum, u64 *nominal_perf)
>>        return cppc_get_perf(cpunum, NOMINAL_PERF, nominal_perf);
>>   }
>>
>> +/**
>> + * cppc_get_highest_perf - Get the highest performance register value.
>> + * @cpunum: CPU from which to get highest performance.
>> + * @highest_perf: Return address.
>> + *
>> + * Return: 0 for success, -EIO otherwise.
>> + */
>> +int cppc_get_highest_perf(int cpunum, u64 *highest_perf)
>> +{
>> +     return cppc_get_perf(cpunum, HIGHEST_PERF, highest_perf);
>> +}
>> +EXPORT_SYMBOL_GPL(cppc_get_highest_perf);
> The Intel P-State driver uses cppc_get_perf_caps(). You would not need to
> export this function.
>
> Having said that, the Intel P-State driver could also use this new
> function, IMO. AFAICS, it does not *have* to use cppc_get_perf_caps().

Yes, you are right.