cpufreq: intel_pstate: Update hybrid scaling factor for Meteor Lake

On some Meteor Lake platforms, maximum one core turbo frequency is not
observed. During hybrid performance to frequency conversion, the maximum
frequency is 100 MHz less. This results in requesting maximum frequency
100 MHz less.

For example when the max one core turbo is 4.9 GHz:
MSR HWP_CAPABILITIES shows highest performance ratio for P-core is 0x3E.
With the current scaling factor of 78741 (1.27x for converting frequency
to performance) results in max frequency of 4.8 GHz. This results in
capping the max scaling frequency as 4.8 GHz, which is 100 MHz less than
the desired.

Add capability to define per CPU model specific scaling factor and define
scaling factor of 80000 (1.25x for converting frequency to performance for
P-cores) for Meteor Lake.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
[ rjw: Debug message adjustment, subject edit ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/intel_pstate.c

@@ -303,6 +303,9 @@ static bool hwp_forced __read_mostly;
 static struct cpufreq_driver *intel_pstate_driver __read_mostly;
 
 #define HYBRID_SCALING_FACTOR		78741
+#define HYBRID_SCALING_FACTOR_MTL	80000
+
+static int hybrid_scaling_factor = HYBRID_SCALING_FACTOR;
 
 static inline int core_get_scaling(void)
 {
@@ -422,7 +425,7 @@ static int intel_pstate_cppc_get_scaling(int cpu)
 	 */
 	if (!ret && cppc_perf.nominal_perf && cppc_perf.nominal_freq &&
 	    cppc_perf.nominal_perf * 100 != cppc_perf.nominal_freq)
-		return HYBRID_SCALING_FACTOR;
+		return hybrid_scaling_factor;
 
 	return core_get_scaling();
 }
@@ -1968,7 +1971,7 @@ static int hwp_get_cpu_scaling(int cpu)
 	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 HYBRID_SCALING_FACTOR;
+		return hybrid_scaling_factor;
 
 	/* Use default core scaling for E-cores */
 	if (cpu_type == 0x20)
@@ -3399,6 +3402,11 @@ static const struct x86_cpu_id intel_epp_balance_perf[] = {
 	{}
 };
 
+static const struct x86_cpu_id intel_hybrid_scaling_factor[] = {
+	X86_MATCH_INTEL_FAM6_MODEL(METEORLAKE_L, HYBRID_SCALING_FACTOR_MTL),
+	{}
+};
+
 static int __init intel_pstate_init(void)
 {
 	static struct cpudata **_all_cpu_data;
@@ -3489,9 +3497,16 @@ static int __init intel_pstate_init(void)
 
 	if (hwp_active) {
 		const struct x86_cpu_id *id = x86_match_cpu(intel_epp_balance_perf);
+		const struct x86_cpu_id *hybrid_id = x86_match_cpu(intel_hybrid_scaling_factor);
 
 		if (id)
 			epp_values[EPP_INDEX_BALANCE_PERFORMANCE] = id->driver_data;
+
+		if (hybrid_id) {
+			hybrid_scaling_factor = hybrid_id->driver_data;
+			pr_debug("hybrid scaling factor: %d\n", hybrid_scaling_factor);
+		}
+
 	}
 
 	mutex_lock(&intel_pstate_driver_lock);