Merge tag 'pm-5.11-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
"Address a performance regression related to scale-invariance on x86
that may prevent turbo CPU frequencies from being used in certain
workloads on systems using acpi-cpufreq as the CPU performance scaling
driver and schedutil as the scaling governor"

* tag 'pm-5.11-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
cpufreq: ACPI: Update arch scale-invariance max perf ratio if CPPC is not there
cpufreq: ACPI: Extend frequency tables to cover boost frequencies

arch/x86/kernel/smpboot.c

···
 	arch_max_freq_ratio = turbo_disabled ? SCHED_CAPACITY_SCALE :
 					arch_turbo_freq_ratio;
 }
+EXPORT_SYMBOL_GPL(arch_set_max_freq_ratio);
 
 static bool turbo_disabled(void)
 {

drivers/cpufreq/acpi-cpufreq.c

···
 #include <linux/uaccess.h>
 
 #include <acpi/processor.h>
+#include <acpi/cppc_acpi.h>
 
 #include <asm/msr.h>
 #include <asm/processor.h>
···
 	unsigned int resume;
 	unsigned int cpu_feature;
 	unsigned int acpi_perf_cpu;
+	unsigned int first_perf_state;
 	cpumask_var_t freqdomain_cpus;
 	void (*cpu_freq_write)(struct acpi_pct_register *reg, u32 val);
 	u32 (*cpu_freq_read)(struct acpi_pct_register *reg);
···
 
 	perf = to_perf_data(data);
 
-	cpufreq_for_each_entry(pos, policy->freq_table)
+	cpufreq_for_each_entry(pos, policy->freq_table + data->first_perf_state)
 		if (msr == perf->states[pos->driver_data].status)
 			return pos->frequency;
-	return policy->freq_table[0].frequency;
+	return policy->freq_table[data->first_perf_state].frequency;
 }
 
 static unsigned extract_freq(struct cpufreq_policy *policy, u32 val)
···
 	struct cpufreq_policy *policy;
 	unsigned int freq;
 	unsigned int cached_freq;
+	unsigned int state;
 
 	pr_debug("%s (%d)\n", __func__, cpu);
 
···
 	if (unlikely(!data || !policy->freq_table))
 		return 0;
 
-	cached_freq = policy->freq_table[to_perf_data(data)->state].frequency;
+	state = to_perf_data(data)->state;
+	if (state < data->first_perf_state)
+		state = data->first_perf_state;
+
+	cached_freq = policy->freq_table[state].frequency;
 	freq = extract_freq(policy, get_cur_val(cpumask_of(cpu), data));
 	if (freq != cached_freq) {
 		/*
···
 }
 #endif
 
+#ifdef CONFIG_ACPI_CPPC_LIB
+static u64 get_max_boost_ratio(unsigned int cpu)
+{
+	struct cppc_perf_caps perf_caps;
+	u64 highest_perf, nominal_perf;
+	int ret;
+
+	if (acpi_pstate_strict)
+		return 0;
+
+	ret = cppc_get_perf_caps(cpu, &perf_caps);
+	if (ret) {
+		pr_debug("CPU%d: Unable to get performance capabilities (%d)\n",
+			 cpu, ret);
+		return 0;
+	}
+
+	highest_perf = perf_caps.highest_perf;
+	nominal_perf = perf_caps.nominal_perf;
+
+	if (!highest_perf || !nominal_perf) {
+		pr_debug("CPU%d: highest or nominal performance missing\n", cpu);
+		return 0;
+	}
+
+	if (highest_perf < nominal_perf) {
+		pr_debug("CPU%d: nominal performance above highest\n", cpu);
+		return 0;
+	}
+
+	return div_u64(highest_perf << SCHED_CAPACITY_SHIFT, nominal_perf);
+}
+#else
+static inline u64 get_max_boost_ratio(unsigned int cpu) { return 0; }
+#endif
+
 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
 {
-	unsigned int i;
-	unsigned int valid_states = 0;
-	unsigned int cpu = policy->cpu;
-	struct acpi_cpufreq_data *data;
-	unsigned int result = 0;
-	struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
-	struct acpi_processor_performance *perf;
 	struct cpufreq_frequency_table *freq_table;
+	struct acpi_processor_performance *perf;
+	struct acpi_cpufreq_data *data;
+	unsigned int cpu = policy->cpu;
+	struct cpuinfo_x86 *c = &cpu_data(cpu);
+	unsigned int valid_states = 0;
+	unsigned int result = 0;
+	unsigned int state_count;
+	u64 max_boost_ratio;
+	unsigned int i;
 #ifdef CONFIG_SMP
 	static int blacklisted;
 #endif
···
 		goto err_unreg;
 	}
 
-	freq_table = kcalloc(perf->state_count + 1, sizeof(*freq_table),
-			     GFP_KERNEL);
+	state_count = perf->state_count + 1;
+
+	max_boost_ratio = get_max_boost_ratio(cpu);
+	if (max_boost_ratio) {
+		/*
+		 * Make a room for one more entry to represent the highest
+		 * available "boost" frequency.
+		 */
+		state_count++;
+		valid_states++;
+		data->first_perf_state = valid_states;
+	} else {
+		/*
+		 * If the maximum "boost" frequency is unknown, ask the arch
+		 * scale-invariance code to use the "nominal" performance for
+		 * CPU utilization scaling so as to prevent the schedutil
+		 * governor from selecting inadequate CPU frequencies.
+		 */
+		arch_set_max_freq_ratio(true);
+	}
+
+	freq_table = kcalloc(state_count, sizeof(*freq_table), GFP_KERNEL);
 	if (!freq_table) {
 		result = -ENOMEM;
 		goto err_unreg;
···
 		valid_states++;
 	}
 	freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
+
+	if (max_boost_ratio) {
+		unsigned int state = data->first_perf_state;
+		unsigned int freq = freq_table[state].frequency;
+
+		/*
+		 * Because the loop above sorts the freq_table entries in the
+		 * descending order, freq is the maximum frequency in the table.
+		 * Assume that it corresponds to the CPPC nominal frequency and
+		 * use it to populate the frequency field of the extra "boost"
+		 * frequency entry.
+		 */
+		freq_table[0].frequency = freq * max_boost_ratio >> SCHED_CAPACITY_SHIFT;
+		/*
+		 * The purpose of the extra "boost" frequency entry is to make
+		 * the rest of cpufreq aware of the real maximum frequency, but
+		 * the way to request it is the same as for the first_perf_state
+		 * entry that is expected to cover the entire range of "boost"
+		 * frequencies of the CPU, so copy the driver_data value from
+		 * that entry.
+		 */
+		freq_table[0].driver_data = freq_table[state].driver_data;
+	}
+
 	policy->freq_table = freq_table;
 	perf->state = 0;
 
···
 {
 	struct acpi_processor_performance *perf = per_cpu_ptr(acpi_perf_data,
 							      policy->cpu);
+	struct acpi_cpufreq_data *data = policy->driver_data;
+	unsigned int freq = policy->freq_table[data->first_perf_state].frequency;
 
-	if (perf->states[0].core_frequency * 1000 != policy->cpuinfo.max_freq)
+	if (perf->states[0].core_frequency * 1000 != freq)
 		pr_warn(FW_WARN "P-state 0 is not max freq\n");
 }