linux-kernel - Re: [RFC PATCH 1/2] cpufreq/amd-pstate: Pass the policy to amd_pstate

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Message-ID: <8fb99491-093e-44e6-9227-8254ac8b51a6@kernel.org>
Date: Tue, 6 Jan 2026 13:30:04 -0600
From: "Mario Limonciello (AMD) (kernel.org)" <superm1@...nel.org>
To: K Prateek Nayak <kprateek.nayak@....com>, Huang Rui <ray.huang@....com>,
 "Gautham R. Shenoy" <gautham.shenoy@....com>,
 "Rafael J. Wysocki" <rafael@...nel.org>,
 Viresh Kumar <viresh.kumar@...aro.org>,
 Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
 Len Brown <lenb@...nel.org>,
 Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
 Clark Williams <clrkwllms@...nel.org>, Bert Karwatzki <spasswolf@....de>,
 linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org,
 linux-rt-devel@...ts.linux.dev
Cc: Perry Yuan <perry.yuan@....com>
Subject: Re: [RFC PATCH 1/2] cpufreq/amd-pstate: Pass the policy to
 amd_pstate_update()



On 1/6/2026 1:36 AM, K Prateek Nayak wrote:
> All callers of amd_pstate_update() already have a reference to the
> cpufreq_policy object.
> 
> Pass the entire policy object and grab the cpudata using
> "policy->driver_data" instead of passing the cpudata and unnecessarily
> grabbing another read-side reference to the cpufreq policy object when
> it is already available in the caller.
> 
> No functional changes intended.
> 
> Signed-off-by: K Prateek Nayak <kprateek.nayak@....com>
Reviewed-by: Mario Limonciello (AMD) <superm1@...nel.org>
> ---
>   drivers/cpufreq/amd-pstate.c | 11 ++++-------
>   1 file changed, 4 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index c45bc98721d2..5818a92d96b9 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -565,15 +565,12 @@ static inline bool amd_pstate_sample(struct amd_cpudata *cpudata)
>   	return true;
>   }
>   
> -static void amd_pstate_update(struct amd_cpudata *cpudata, u8 min_perf,
> +static void amd_pstate_update(struct cpufreq_policy *policy, u8 min_perf,
>   			      u8 des_perf, u8 max_perf, bool fast_switch, int gov_flags)
>   {
> -	struct cpufreq_policy *policy __free(put_cpufreq_policy) = cpufreq_cpu_get(cpudata->cpu);
> +	struct amd_cpudata *cpudata = policy->driver_data;
>   	union perf_cached perf = READ_ONCE(cpudata->perf);
>   
> -	if (!policy)
> -		return;
> -
>   	/* limit the max perf when core performance boost feature is disabled */
>   	if (!cpudata->boost_supported)
>   		max_perf = min_t(u8, perf.nominal_perf, max_perf);
> @@ -675,7 +672,7 @@ static int amd_pstate_update_freq(struct cpufreq_policy *policy,
>   	if (!fast_switch)
>   		cpufreq_freq_transition_begin(policy, &freqs);
>   
> -	amd_pstate_update(cpudata, perf.min_limit_perf, des_perf,
> +	amd_pstate_update(policy, perf.min_limit_perf, des_perf,
>   			  perf.max_limit_perf, fast_switch,
>   			  policy->governor->flags);
>   
> @@ -737,7 +734,7 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
>   	if (max_perf < min_perf)
>   		max_perf = min_perf;
>   
> -	amd_pstate_update(cpudata, min_perf, des_perf, max_perf, true,
> +	amd_pstate_update(policy, min_perf, des_perf, max_perf, true,
>   			policy->governor->flags);
>   }
>