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Message-ID: <Z1bFcicdCUgVNCGw@BLRRASHENOY1.amd.com>
Date: Mon, 9 Dec 2024 15:54:50 +0530
From: "Gautham R. Shenoy" <gautham.shenoy@....com>
To: Mario Limonciello <mario.limonciello@....com>
Cc: Perry Yuan <perry.yuan@....com>, linux-kernel@...r.kernel.org,
linux-pm@...r.kernel.org,
Dhananjay Ugwekar <Dhananjay.Ugwekar@....com>
Subject: Re: [PATCH v2 16/16] cpufreq/amd-pstate: Drop boost_state variable
Hello Mario,
On Sun, Dec 08, 2024 at 12:30:31AM -0600, Mario Limonciello wrote:
> Currently boost_state is cached for every processor in cpudata structure
> and driver boost state is set for every processor.
>
> Both of these aren't necessary as the driver only needs to set once and
> the policy stores whether boost is enabled.
>
> Move the driver boost setting to registration and adjust all references
> to cached value to pull from the policy instead.
>
> Signed-off-by: Mario Limonciello <mario.limonciello@....com>
Thanks for cleaning this up.
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@....com>
--
Thanks and Regards
gautham.
> ---
> drivers/cpufreq/amd-pstate.c | 26 +++++++++++++-------------
> drivers/cpufreq/amd-pstate.h | 1 -
> 2 files changed, 13 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index a4ededb8d89df..3f6208828c063 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -315,9 +315,10 @@ static int shmem_set_epp(struct amd_cpudata *cpudata, u32 epp)
> return ret;
> }
>
> -static int amd_pstate_set_energy_pref_index(struct amd_cpudata *cpudata,
> - int pref_index)
> +static int amd_pstate_set_energy_pref_index(struct cpufreq_policy *policy,
> + int pref_index)
> {
> + struct amd_cpudata *cpudata = policy->driver_data;
> int epp;
>
> if (!pref_index)
> @@ -335,7 +336,7 @@ static int amd_pstate_set_energy_pref_index(struct amd_cpudata *cpudata,
> epp,
> FIELD_GET(AMD_CPPC_MIN_PERF_MASK, cpudata->cppc_req_cached),
> FIELD_GET(AMD_CPPC_MAX_PERF_MASK, cpudata->cppc_req_cached),
> - cpudata->boost_state);
> + policy->boost_enabled);
> }
>
> return amd_pstate_set_epp(cpudata, epp);
> @@ -746,7 +747,6 @@ static int amd_pstate_set_boost(struct cpufreq_policy *policy, int state)
> guard(mutex)(&amd_pstate_driver_lock);
>
> ret = amd_pstate_cpu_boost_update(policy, state);
> - WRITE_ONCE(cpudata->boost_state, !ret ? state : false);
> policy->boost_enabled = !ret ? state : false;
> refresh_frequency_limits(policy);
>
> @@ -768,9 +768,6 @@ static int amd_pstate_init_boost_support(struct amd_cpudata *cpudata)
> goto exit_err;
> }
>
> - /* at least one CPU supports CPB, even if others fail later on to set up */
> - current_pstate_driver->boost_enabled = true;
> -
> ret = rdmsrl_on_cpu(cpudata->cpu, MSR_K7_HWCR, &boost_val);
> if (ret) {
> pr_err_once("failed to read initial CPU boost state!\n");
> @@ -1176,7 +1173,6 @@ static ssize_t show_energy_performance_available_preferences(
> static ssize_t store_energy_performance_preference(
> struct cpufreq_policy *policy, const char *buf, size_t count)
> {
> - struct amd_cpudata *cpudata = policy->driver_data;
> char str_preference[21];
> ssize_t ret;
>
> @@ -1190,7 +1186,7 @@ static ssize_t store_energy_performance_preference(
>
> guard(mutex)(&amd_pstate_limits_lock);
>
> - ret = amd_pstate_set_energy_pref_index(cpudata, ret);
> + ret = amd_pstate_set_energy_pref_index(policy, ret);
>
> return ret ? ret : count;
> }
> @@ -1265,6 +1261,9 @@ static int amd_pstate_register_driver(int mode)
> return ret;
> }
>
> + /* at least one CPU supports CPB */
> + current_pstate_driver->boost_enabled = cpu_feature_enabled(X86_FEATURE_CPB);
> +
> ret = cpufreq_register_driver(current_pstate_driver);
> if (ret) {
> amd_pstate_driver_cleanup();
> @@ -1604,8 +1603,9 @@ static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy)
> return 0;
> }
>
> -static int amd_pstate_epp_reenable(struct amd_cpudata *cpudata)
> +static int amd_pstate_epp_reenable(struct cpufreq_policy *policy)
> {
> + struct amd_cpudata *cpudata = policy->driver_data;
> u64 max_perf;
> int ret;
>
> @@ -1619,7 +1619,7 @@ static int amd_pstate_epp_reenable(struct amd_cpudata *cpudata)
> trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf,
> cpudata->epp_cached,
> FIELD_GET(AMD_CPPC_MIN_PERF_MASK, cpudata->cppc_req_cached),
> - max_perf, cpudata->boost_state);
> + max_perf, policy->boost_enabled);
> }
>
> return amd_pstate_update_perf(cpudata, 0, 0, max_perf, cpudata->epp_cached, false);
> @@ -1632,7 +1632,7 @@ static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy)
>
> pr_debug("AMD CPU Core %d going online\n", cpudata->cpu);
>
> - ret = amd_pstate_epp_reenable(cpudata);
> + ret = amd_pstate_epp_reenable(policy);
> if (ret)
> return ret;
> cpudata->suspended = false;
> @@ -1690,7 +1690,7 @@ static int amd_pstate_epp_resume(struct cpufreq_policy *policy)
> guard(mutex)(&amd_pstate_limits_lock);
>
> /* enable amd pstate from suspend state*/
> - amd_pstate_epp_reenable(cpudata);
> + amd_pstate_epp_reenable(policy);
>
> cpudata->suspended = false;
> }
> diff --git a/drivers/cpufreq/amd-pstate.h b/drivers/cpufreq/amd-pstate.h
> index 7765c82f975c6..9747e3be6ceee 100644
> --- a/drivers/cpufreq/amd-pstate.h
> +++ b/drivers/cpufreq/amd-pstate.h
> @@ -98,7 +98,6 @@ struct amd_cpudata {
> u64 cppc_cap1_cached;
> bool suspended;
> s16 epp_default;
> - bool boost_state;
> };
>
> /*
> --
> 2.43.0
>
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