cpufreq: intel_pstate: Do not walk policy->cpus

intel_pstate_hwp_set() is the only function walking policy->cpus
in intel_pstate.  The rest of the code simply assumes one CPU per
policy, including the initialization code.

Therefore it doesn't make sense for intel_pstate_hwp_set() to
walk policy->cpus as it is guaranteed to have only one bit set
for policy->cpu.

For this reason, rearrange intel_pstate_hwp_set() to take the CPU
number as the argument and drop the loop over policy->cpus from it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 6384557..5236701 100644 (file)
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -792,84 +792,80 @@ static struct freq_attr *hwp_cpufreq_attrs[] = {
        NULL,
 };
 
-static void intel_pstate_hwp_set(struct cpufreq_policy *policy)
+static void intel_pstate_hwp_set(unsigned int cpu)
 {
-       int min, hw_min, max, hw_max, cpu;
+       struct cpudata *cpu_data = all_cpu_data[cpu];
+       int min, hw_min, max, hw_max;
        u64 value, cap;
+       s16 epp;
 
-       for_each_cpu(cpu, policy->cpus) {
-               struct cpudata *cpu_data = all_cpu_data[cpu];
-               s16 epp;
-
-               rdmsrl_on_cpu(cpu, MSR_HWP_CAPABILITIES, &cap);
-               hw_min = HWP_LOWEST_PERF(cap);
-               if (global.no_turbo)
-                       hw_max = HWP_GUARANTEED_PERF(cap);
-               else
-                       hw_max = HWP_HIGHEST_PERF(cap);
-
-               max = fp_ext_toint(hw_max * cpu_data->max_perf);
-               if (cpu_data->policy == CPUFREQ_POLICY_PERFORMANCE)
-                       min = max;
-               else
-                       min = fp_ext_toint(hw_max * cpu_data->min_perf);
+       rdmsrl_on_cpu(cpu, MSR_HWP_CAPABILITIES, &cap);
+       hw_min = HWP_LOWEST_PERF(cap);
+       if (global.no_turbo)
+               hw_max = HWP_GUARANTEED_PERF(cap);
+       else
+               hw_max = HWP_HIGHEST_PERF(cap);
 
-               rdmsrl_on_cpu(cpu, MSR_HWP_REQUEST, &value);
+       max = fp_ext_toint(hw_max * cpu_data->max_perf);
+       if (cpu_data->policy == CPUFREQ_POLICY_PERFORMANCE)
+               min = max;
+       else
+               min = fp_ext_toint(hw_max * cpu_data->min_perf);
 
-               value &= ~HWP_MIN_PERF(~0L);
-               value |= HWP_MIN_PERF(min);
+       rdmsrl_on_cpu(cpu, MSR_HWP_REQUEST, &value);
 
-               value &= ~HWP_MAX_PERF(~0L);
-               value |= HWP_MAX_PERF(max);
+       value &= ~HWP_MIN_PERF(~0L);
+       value |= HWP_MIN_PERF(min);
 
-               if (cpu_data->epp_policy == cpu_data->policy)
-                       goto skip_epp;
+       value &= ~HWP_MAX_PERF(~0L);
+       value |= HWP_MAX_PERF(max);
 
-               cpu_data->epp_policy = cpu_data->policy;
+       if (cpu_data->epp_policy == cpu_data->policy)
+               goto skip_epp;
 
-               if (cpu_data->epp_saved >= 0) {
-                       epp = cpu_data->epp_saved;
-                       cpu_data->epp_saved = -EINVAL;
-                       goto update_epp;
-               }
+       cpu_data->epp_policy = cpu_data->policy;
 
-               if (cpu_data->policy == CPUFREQ_POLICY_PERFORMANCE) {
-                       epp = intel_pstate_get_epp(cpu_data, value);
-                       cpu_data->epp_powersave = epp;
-                       /* If EPP read was failed, then don't try to write */
-                       if (epp < 0)
-                               goto skip_epp;
+       if (cpu_data->epp_saved >= 0) {
+               epp = cpu_data->epp_saved;
+               cpu_data->epp_saved = -EINVAL;
+               goto update_epp;
+       }
 
+       if (cpu_data->policy == CPUFREQ_POLICY_PERFORMANCE) {
+               epp = intel_pstate_get_epp(cpu_data, value);
+               cpu_data->epp_powersave = epp;
+               /* If EPP read was failed, then don't try to write */
+               if (epp < 0)
+                       goto skip_epp;
 
-                       epp = 0;
-               } else {
-                       /* skip setting EPP, when saved value is invalid */
-                       if (cpu_data->epp_powersave < 0)
-                               goto skip_epp;
+               epp = 0;
+       } else {
+               /* skip setting EPP, when saved value is invalid */
+               if (cpu_data->epp_powersave < 0)
+                       goto skip_epp;
 
-                       /*
-                        * No need to restore EPP when it is not zero. This
-                        * means:
-                        *  - Policy is not changed
-                        *  - user has manually changed
-                        *  - Error reading EPB
-                        */
-                       epp = intel_pstate_get_epp(cpu_data, value);
-                       if (epp)
-                               goto skip_epp;
+               /*
+                * No need to restore EPP when it is not zero. This
+                * means:
+                *  - Policy is not changed
+                *  - user has manually changed
+                *  - Error reading EPB
+                */
+               epp = intel_pstate_get_epp(cpu_data, value);
+               if (epp)
+                       goto skip_epp;
 
-                       epp = cpu_data->epp_powersave;
-               }
+               epp = cpu_data->epp_powersave;
+       }
 update_epp:
-               if (static_cpu_has(X86_FEATURE_HWP_EPP)) {
-                       value &= ~GENMASK_ULL(31, 24);
-                       value |= (u64)epp << 24;
-               } else {
-                       intel_pstate_set_epb(cpu, epp);
-               }
-skip_epp:
-               wrmsrl_on_cpu(cpu, MSR_HWP_REQUEST, value);
+       if (static_cpu_has(X86_FEATURE_HWP_EPP)) {
+               value &= ~GENMASK_ULL(31, 24);
+               value |= (u64)epp << 24;
+       } else {
+               intel_pstate_set_epb(cpu, epp);
        }
+skip_epp:
+       wrmsrl_on_cpu(cpu, MSR_HWP_REQUEST, value);
 }
 
 static int intel_pstate_hwp_save_state(struct cpufreq_policy *policy)
@@ -892,7 +888,7 @@ static int intel_pstate_resume(struct cpufreq_policy *policy)
        mutex_lock(&intel_pstate_limits_lock);
 
        all_cpu_data[policy->cpu]->epp_policy = 0;
-       intel_pstate_hwp_set(policy);
+       intel_pstate_hwp_set(policy->cpu);
 
        mutex_unlock(&intel_pstate_limits_lock);
 
@@ -2057,7 +2053,7 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)
        intel_pstate_set_update_util_hook(policy->cpu);
 
        if (hwp_active)
-               intel_pstate_hwp_set(policy);
+               intel_pstate_hwp_set(policy->cpu);
 
        mutex_unlock(&intel_pstate_limits_lock);