x86/aperfmperf: Separate AP/BP frequency invariance init

This code is convoluted and because it can be invoked post init via the
ACPI/CPPC code, all of the initialization functionality is built in instead
of being part of init text and init data.

As a first step create separate calls for the boot and the application
processors.

Signed-off-by: Thomas Gleixner <[e-mail]>
Reviewed-by: Rafael J. Wysocki <[e-mail]>
Acked-by: Peter Zijlstra (Intel) <[e-mail]>
Acked-by: Paul E. McKenney <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

arch/x86/include/asm/topology.h

···
 #define arch_scale_freq_tick arch_scale_freq_tick
 
 extern void arch_set_max_freq_ratio(bool turbo_disabled);
-void init_freq_invariance(bool secondary, bool cppc_ready);
+extern void bp_init_freq_invariance(bool cppc_ready);
+extern void ap_init_freq_invariance(void);
 #else
-static inline void arch_set_max_freq_ratio(bool turbo_disabled)
-{
-}
-static inline void init_freq_invariance(bool secondary, bool cppc_ready)
-{
-}
+static inline void arch_set_max_freq_ratio(bool turbo_disabled) { }
+static inline void bp_init_freq_invariance(bool cppc_ready) { }
+static inline void ap_init_freq_invariance(void) { }
 #endif
 
 #ifdef CONFIG_ACPI_CPPC_LIB

arch/x86/kernel/acpi/cppc.c

···
 
 	mutex_lock(&freq_invariance_lock);
 
-	init_freq_invariance(secondary, true);
+	if (!secondary)
+		bp_init_freq_invariance(true);
 	secondary = true;
 
 	mutex_unlock(&freq_invariance_lock);

arch/x86/kernel/cpu/aperfmperf.c

···
 static inline void register_freq_invariance_syscore_ops(void) {}
 #endif
 
-void init_freq_invariance(bool secondary, bool cppc_ready)
+void bp_init_freq_invariance(bool cppc_ready)
 {
-	bool ret = false;
+	bool ret;
 
-	if (!boot_cpu_has(X86_FEATURE_APERFMPERF))
+	if (!cpu_feature_enabled(X86_FEATURE_APERFMPERF))
 		return;
 
-	if (secondary) {
-		if (static_branch_likely(&arch_scale_freq_key)) {
-			init_counter_refs();
-		}
-		return;
-	}
+	init_counter_refs();
 
 	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
 		ret = intel_set_max_freq_ratio();
 	else if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) {
-		if (!cppc_ready) {
+		if (!cppc_ready)
 			return;
-		}
 		ret = amd_set_max_freq_ratio(&arch_turbo_freq_ratio);
 	}
 
 	if (ret) {
-		init_counter_refs();
 		static_branch_enable(&arch_scale_freq_key);
 		register_freq_invariance_syscore_ops();
 		pr_info("Estimated ratio of average max frequency by base frequency (times 1024): %llu\n", arch_max_freq_ratio);
 	} else {
 		pr_debug("Couldn't determine max cpu frequency, necessary for scale-invariant accounting.\n");
 	}
+}
+
+void ap_init_freq_invariance(void)
+{
+	if (cpu_feature_enabled(X86_FEATURE_APERFMPERF))
+		init_counter_refs();
 }
 
 static void disable_freq_invariance_workfn(struct work_struct *work)

arch/x86/kernel/smpboot.c

···
 	 */
 	set_cpu_sibling_map(raw_smp_processor_id());
 
-	init_freq_invariance(true, false);
+	ap_init_freq_invariance();
 
 	/*
 	 * Get our bogomips.
···
 {
 	smp_prepare_cpus_common();
 
-	init_freq_invariance(false, false);
+	bp_init_freq_invariance(false);
 	smp_sanity_check();
 
 	switch (apic_intr_mode) {