1 files changed, 55 insertions, 10 deletions

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 2548ec92faa2..dc50c9fb488d 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -302,6 +302,13 @@ static bool hwp_forced __read_mostly;
 
 static struct cpufreq_driver *intel_pstate_driver __read_mostly;
 
+#define HYBRID_SCALING_FACTOR	78741
+
+static inline int core_get_scaling(void)
+{
+	return 100000;
+}
+
 #ifdef CONFIG_ACPI
 static bool acpi_ppc;
 #endif
@@ -400,6 +407,26 @@ static int intel_pstate_get_cppc_guaranteed(int cpu)
 
 	return cppc_perf.nominal_perf;
 }
+
+static int intel_pstate_cppc_get_scaling(int cpu)
+{
+	struct cppc_perf_caps cppc_perf;
+	int ret;
+
+	ret = cppc_get_perf_caps(cpu, &cppc_perf);
+
+	/*
+	 * If the nominal frequency and the nominal performance are not
+	 * zero and the ratio between them is not 100, return the hybrid
+	 * scaling factor.
+	 */
+	if (!ret && cppc_perf.nominal_perf && cppc_perf.nominal_freq &&
+	    cppc_perf.nominal_perf * 100 != cppc_perf.nominal_freq)
+		return HYBRID_SCALING_FACTOR;
+
+	return core_get_scaling();
+}
+
 #else /* CONFIG_ACPI_CPPC_LIB */
 static inline void intel_pstate_set_itmt_prio(int cpu)
 {
@@ -492,6 +519,11 @@ static inline int intel_pstate_get_cppc_guaranteed(int cpu)
 {
 	return -ENOTSUPP;
 }
+
+static int intel_pstate_cppc_get_scaling(int cpu)
+{
+	return core_get_scaling();
+}
 #endif /* CONFIG_ACPI_CPPC_LIB */
 
 /**
@@ -824,6 +856,8 @@ static ssize_t store_energy_performance_preference(
 			err = cpufreq_start_governor(policy);
 			if (!ret)
 				ret = err;
+		} else {
+			ret = 0;
 		}
 	}
 
@@ -1895,11 +1929,6 @@ static int core_get_turbo_pstate(int cpu)
 	return ret;
 }
 
-static inline int core_get_scaling(void)
-{
-	return 100000;
-}
-
 static u64 core_get_val(struct cpudata *cpudata, int pstate)
 {
 	u64 val;
@@ -1936,16 +1965,28 @@ static void hybrid_get_type(void *data)
 	*cpu_type = get_this_hybrid_cpu_type();
 }
 
-static int hybrid_get_cpu_scaling(int cpu)
+static int hwp_get_cpu_scaling(int cpu)
 {
 	u8 cpu_type = 0;
 
 	smp_call_function_single(cpu, hybrid_get_type, &cpu_type, 1);
 	/* P-cores have a smaller perf level-to-freqency scaling factor. */
 	if (cpu_type == 0x40)
-		return 78741;
+		return HYBRID_SCALING_FACTOR;
 
-	return core_get_scaling();
+	/* Use default core scaling for E-cores */
+	if (cpu_type == 0x20)
+		return core_get_scaling();
+
+	/*
+	 * If reached here, this system is either non-hybrid (like Tiger
+	 * Lake) or hybrid-capable (like Alder Lake or Raptor Lake) with
+	 * no E cores (in which case CPUID for hybrid support is 0).
+	 *
+	 * The CPPC nominal_frequency field is 0 for non-hybrid systems,
+	 * so the default core scaling will be used for them.
+	 */
+	return intel_pstate_cppc_get_scaling(cpu);
 }
 
 static void intel_pstate_set_pstate(struct cpudata *cpu, int pstate)
@@ -2568,6 +2609,11 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)
 			intel_pstate_clear_update_util_hook(policy->cpu);
 		intel_pstate_hwp_set(policy->cpu);
 	}
+	/*
+	 * policy->cur is never updated with the intel_pstate driver, but it
+	 * is used as a stale frequency value. So, keep it within limits.
+	 */
+	policy->cur = policy->min;
 
 	mutex_unlock(&intel_pstate_limits_lock);
 
@@ -3393,8 +3439,7 @@ static int __init intel_pstate_init(void)
 			if (!default_driver)
 				default_driver = &intel_pstate;
 
-			if (boot_cpu_has(X86_FEATURE_HYBRID_CPU))
-				pstate_funcs.get_cpu_scaling = hybrid_get_cpu_scaling;
+			pstate_funcs.get_cpu_scaling = hwp_get_cpu_scaling;
 
 			goto hwp_cpu_matched;
 		}