Merge branch 'pm-cpufreq'

Merge cpufreq fixes for 6.8-rc2:

 - Fix the handling of scaling_max/min_freq sysfs attributes in the AMD
   P-state cpufreq driver (Mario Limonciello).

 - Make the intel_pstate cpufreq driver avoid unnecessary computation of
   the HWP performance level corresponding to a given frequency in the
   cases when it is known already, which also helps to avoid reducing
   the maximum CPU capacity artificially on some systems (Rafael J.
   Wysocki).

* pm-cpufreq:
  cpufreq/amd-pstate: Fix setting scaling max/min freq values
  cpufreq: intel_pstate: Refine computation of P-state for given frequency

Author: rafaeljw

drivers/cpufreq/amd-pstate.c

@@ -1232,14 +1232,13 @@ static void amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
 	max_limit_perf = div_u64(policy->max * cpudata->highest_perf, cpudata->max_freq);
 	min_limit_perf = div_u64(policy->min * cpudata->highest_perf, cpudata->max_freq);
 
+	WRITE_ONCE(cpudata->max_limit_perf, max_limit_perf);
+	WRITE_ONCE(cpudata->min_limit_perf, min_limit_perf);
+
 	max_perf = clamp_t(unsigned long, max_perf, cpudata->min_limit_perf,
 			cpudata->max_limit_perf);
 	min_perf = clamp_t(unsigned long, min_perf, cpudata->min_limit_perf,
 			cpudata->max_limit_perf);
-
-	WRITE_ONCE(cpudata->max_limit_perf, max_limit_perf);
-	WRITE_ONCE(cpudata->min_limit_perf, min_limit_perf);
-
 	value = READ_ONCE(cpudata->cppc_req_cached);
 
 	if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)

drivers/cpufreq/intel_pstate.c

@@ -529,6 +529,30 @@ static int intel_pstate_cppc_get_scaling(int cpu)
 }
 #endif /* CONFIG_ACPI_CPPC_LIB */
 
+static int intel_pstate_freq_to_hwp_rel(struct cpudata *cpu, int freq,
+					unsigned int relation)
+{
+	if (freq == cpu->pstate.turbo_freq)
+		return cpu->pstate.turbo_pstate;
+
+	if (freq == cpu->pstate.max_freq)
+		return cpu->pstate.max_pstate;
+
+	switch (relation) {
+	case CPUFREQ_RELATION_H:
+		return freq / cpu->pstate.scaling;
+	case CPUFREQ_RELATION_C:
+		return DIV_ROUND_CLOSEST(freq, cpu->pstate.scaling);
+	}
+
+	return DIV_ROUND_UP(freq, cpu->pstate.scaling);
+}
+
+static int intel_pstate_freq_to_hwp(struct cpudata *cpu, int freq)
+{
+	return intel_pstate_freq_to_hwp_rel(cpu, freq, CPUFREQ_RELATION_L);
+}
+
 /**
  * intel_pstate_hybrid_hwp_adjust - Calibrate HWP performance levels.
  * @cpu: Target CPU.
@@ -546,6 +570,7 @@ static void intel_pstate_hybrid_hwp_adjust(struct cpudata *cpu)
 	int perf_ctl_scaling = cpu->pstate.perf_ctl_scaling;
 	int perf_ctl_turbo = pstate_funcs.get_turbo(cpu->cpu);
 	int scaling = cpu->pstate.scaling;
+	int freq;
 
 	pr_debug("CPU%d: perf_ctl_max_phys = %d\n", cpu->cpu, perf_ctl_max_phys);
 	pr_debug("CPU%d: perf_ctl_turbo = %d\n", cpu->cpu, perf_ctl_turbo);
@@ -559,16 +584,16 @@ static void intel_pstate_hybrid_hwp_adjust(struct cpudata *cpu)
 	cpu->pstate.max_freq = rounddown(cpu->pstate.max_pstate * scaling,
 					 perf_ctl_scaling);
 
-	cpu->pstate.max_pstate_physical =
-			DIV_ROUND_UP(perf_ctl_max_phys * perf_ctl_scaling,
-				     scaling);
+	freq = perf_ctl_max_phys * perf_ctl_scaling;
+	cpu->pstate.max_pstate_physical = intel_pstate_freq_to_hwp(cpu, freq);
 
-	cpu->pstate.min_freq = cpu->pstate.min_pstate * perf_ctl_scaling;
+	freq = cpu->pstate.min_pstate * perf_ctl_scaling;
+	cpu->pstate.min_freq = freq;
 	/*
 	 * Cast the min P-state value retrieved via pstate_funcs.get_min() to
 	 * the effective range of HWP performance levels.
 	 */
-	cpu->pstate.min_pstate = DIV_ROUND_UP(cpu->pstate.min_freq, scaling);
+	cpu->pstate.min_pstate = intel_pstate_freq_to_hwp(cpu, freq);
 }
 
 static inline void update_turbo_state(void)
@@ -2528,13 +2553,12 @@ static void intel_pstate_update_perf_limits(struct cpudata *cpu,
 	 * abstract values to represent performance rather than pure ratios.
 	 */
 	if (hwp_active && cpu->pstate.scaling != perf_ctl_scaling) {
-		int scaling = cpu->pstate.scaling;
 		int freq;
 
 		freq = max_policy_perf * perf_ctl_scaling;
-		max_policy_perf = DIV_ROUND_UP(freq, scaling);
+		max_policy_perf = intel_pstate_freq_to_hwp(cpu, freq);
 		freq = min_policy_perf * perf_ctl_scaling;
-		min_policy_perf = DIV_ROUND_UP(freq, scaling);
+		min_policy_perf = intel_pstate_freq_to_hwp(cpu, freq);
 	}
 
 	pr_debug("cpu:%d min_policy_perf:%d max_policy_perf:%d\n",
@@ -2908,18 +2932,7 @@ static int intel_cpufreq_target(struct cpufreq_policy *policy,
 
 	cpufreq_freq_transition_begin(policy, &freqs);
 
-	switch (relation) {
-	case CPUFREQ_RELATION_L:
-		target_pstate = DIV_ROUND_UP(freqs.new, cpu->pstate.scaling);
-		break;
-	case CPUFREQ_RELATION_H:
-		target_pstate = freqs.new / cpu->pstate.scaling;
-		break;
-	default:
-		target_pstate = DIV_ROUND_CLOSEST(freqs.new, cpu->pstate.scaling);
-		break;
-	}
-
+	target_pstate = intel_pstate_freq_to_hwp_rel(cpu, freqs.new, relation);
 	target_pstate = intel_cpufreq_update_pstate(policy, target_pstate, false);
 
 	freqs.new = target_pstate * cpu->pstate.scaling;
@@ -2937,7 +2950,7 @@ static unsigned int intel_cpufreq_fast_switch(struct cpufreq_policy *policy,
 
 	update_turbo_state();
 
-	target_pstate = DIV_ROUND_UP(target_freq, cpu->pstate.scaling);
+	target_pstate = intel_pstate_freq_to_hwp(cpu, target_freq);
 
 	target_pstate = intel_cpufreq_update_pstate(policy, target_pstate, true);