x86/aperfmperf: Untangle Intel and AMD frequency invariance init

AMD boot CPU initialization happens late via ACPI/CPPC which prevents the
Intel parts from being marked __init.

Split out the common code and provide a dedicated interface for the AMD
initialization and mark the Intel specific code and data __init.

The remaining text size is almost cut in half:

  text:		2614	->	1350
  init.text:	   0	->	 786

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20220415161206.592465719@linutronix.de

diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h
index e2faedc6e793783377f6ff465d02c8020f006f70..cc317077e73eef65dc146bfdd72b4b941185c4d5 100644 (file)
--- a/arch/x86/include/asm/topology.h
+++ b/arch/x86/include/asm/topology.h
@@ -216,24 +216,19 @@ extern void arch_scale_freq_tick(void);
 #define arch_scale_freq_tick arch_scale_freq_tick
 
 extern void arch_set_max_freq_ratio(bool turbo_disabled);
-extern void bp_init_freq_invariance(bool cppc_ready);
+extern void freq_invariance_set_perf_ratio(u64 ratio, bool turbo_disabled);
+extern void bp_init_freq_invariance(void);
 extern void ap_init_freq_invariance(void);
 #else
 static inline void arch_set_max_freq_ratio(bool turbo_disabled) { }
-static inline void bp_init_freq_invariance(bool cppc_ready) { }
+static inline void freq_invariance_set_perf_ratio(u64 ratio, bool turbo_disabled) { }
+static inline void bp_init_freq_invariance(void) { }
 static inline void ap_init_freq_invariance(void) { }
 #endif
 
 #ifdef CONFIG_ACPI_CPPC_LIB
 void init_freq_invariance_cppc(void);
 #define arch_init_invariance_cppc init_freq_invariance_cppc
-
-bool amd_set_max_freq_ratio(u64 *ratio);
-#else
-static inline bool amd_set_max_freq_ratio(u64 *ratio)
-{
-       return false;
-}
 #endif
 
 #endif /* _ASM_X86_TOPOLOGY_H */

diff --git a/arch/x86/kernel/acpi/cppc.c b/arch/x86/kernel/acpi/cppc.c
index 06109d927a188acf3c2e8f414122391a84ffe119..8b8cbf22461a4feff2249a2d731b538a31c30501 100644 (file)
--- a/arch/x86/kernel/acpi/cppc.c
+++ b/arch/x86/kernel/acpi/cppc.c
@@ -50,20 +50,17 @@ int cpc_write_ffh(int cpunum, struct cpc_reg *reg, u64 val)
        return err;
 }
 
-bool amd_set_max_freq_ratio(u64 *ratio)
+static void amd_set_max_freq_ratio(void)
 {
        struct cppc_perf_caps perf_caps;
        u64 highest_perf, nominal_perf;
        u64 perf_ratio;
        int rc;
 
-       if (!ratio)
-               return false;
-
        rc = cppc_get_perf_caps(0, &perf_caps);
        if (rc) {
                pr_debug("Could not retrieve perf counters (%d)\n", rc);
-               return false;
+               return;
        }
 
        highest_perf = amd_get_highest_perf();
@@ -71,7 +68,7 @@ bool amd_set_max_freq_ratio(u64 *ratio)
 
        if (!highest_perf || !nominal_perf) {
                pr_debug("Could not retrieve highest or nominal performance\n");
-               return false;
+               return;
        }
 
        perf_ratio = div_u64(highest_perf * SCHED_CAPACITY_SCALE, nominal_perf);
@@ -79,26 +76,27 @@ bool amd_set_max_freq_ratio(u64 *ratio)
        perf_ratio = (perf_ratio + SCHED_CAPACITY_SCALE) >> 1;
        if (!perf_ratio) {
                pr_debug("Non-zero highest/nominal perf values led to a 0 ratio\n");
-               return false;
+               return;
        }
 
-       *ratio = perf_ratio;
-       arch_set_max_freq_ratio(false);
-
-       return true;
+       freq_invariance_set_perf_ratio(perf_ratio, false);
 }
 
 static DEFINE_MUTEX(freq_invariance_lock);
 
 void init_freq_invariance_cppc(void)
 {
-       static bool secondary;
+       static bool init_done;
 
-       mutex_lock(&freq_invariance_lock);
+       if (!cpu_feature_enabled(X86_FEATURE_APERFMPERF))
+               return;
 
-       if (!secondary)
-               bp_init_freq_invariance(true);
-       secondary = true;
+       if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
+               return;
 
+       mutex_lock(&freq_invariance_lock);
+       if (!init_done)
+               amd_set_max_freq_ratio();
+       init_done = true;
        mutex_unlock(&freq_invariance_lock);
 }

diff --git a/arch/x86/kernel/cpu/aperfmperf.c b/arch/x86/kernel/cpu/aperfmperf.c
index 87f34f23a9744b5e8a6e0d9166c76d29d0bd20b8..b4f4ea529f2d09f5effa7ead864b8dfc706c17cf 100644 (file)
--- a/arch/x86/kernel/cpu/aperfmperf.c
+++ b/arch/x86/kernel/cpu/aperfmperf.c
@@ -206,7 +206,7 @@ void arch_set_max_freq_ratio(bool turbo_disabled)
 }
 EXPORT_SYMBOL_GPL(arch_set_max_freq_ratio);
 
-static bool turbo_disabled(void)
+static bool __init turbo_disabled(void)
 {
        u64 misc_en;
        int err;
@@ -218,7 +218,7 @@ static bool turbo_disabled(void)
        return (misc_en & MSR_IA32_MISC_ENABLE_TURBO_DISABLE);
 }
 
-static bool slv_set_max_freq_ratio(u64 *base_freq, u64 *turbo_freq)
+static bool __init slv_set_max_freq_ratio(u64 *base_freq, u64 *turbo_freq)
 {
        int err;
 
@@ -240,26 +240,26 @@ static bool slv_set_max_freq_ratio(u64 *base_freq, u64 *turbo_freq)
        X86_MATCH_VENDOR_FAM_MODEL_FEATURE(INTEL, 6,            \
                INTEL_FAM6_##model, X86_FEATURE_APERFMPERF, NULL)
 
-static const struct x86_cpu_id has_knl_turbo_ratio_limits[] = {
+static const struct x86_cpu_id has_knl_turbo_ratio_limits[] __initconst = {
        X86_MATCH(XEON_PHI_KNL),
        X86_MATCH(XEON_PHI_KNM),
        {}
 };
 
-static const struct x86_cpu_id has_skx_turbo_ratio_limits[] = {
+static const struct x86_cpu_id has_skx_turbo_ratio_limits[] __initconst = {
        X86_MATCH(SKYLAKE_X),
        {}
 };
 
-static const struct x86_cpu_id has_glm_turbo_ratio_limits[] = {
+static const struct x86_cpu_id has_glm_turbo_ratio_limits[] __initconst = {
        X86_MATCH(ATOM_GOLDMONT),
        X86_MATCH(ATOM_GOLDMONT_D),
        X86_MATCH(ATOM_GOLDMONT_PLUS),
        {}
 };
 
-static bool knl_set_max_freq_ratio(u64 *base_freq, u64 *turbo_freq,
-                               int num_delta_fratio)
+static bool __init knl_set_max_freq_ratio(u64 *base_freq, u64 *turbo_freq,
+                                         int num_delta_fratio)
 {
        int fratio, delta_fratio, found;
        int err, i;
@@ -297,7 +297,7 @@ static bool knl_set_max_freq_ratio(u64 *base_freq, u64 *turbo_freq,
        return true;
 }
 
-static bool skx_set_max_freq_ratio(u64 *base_freq, u64 *turbo_freq, int size)
+static bool __init skx_set_max_freq_ratio(u64 *base_freq, u64 *turbo_freq, int size)
 {
        u64 ratios, counts;
        u32 group_size;
@@ -328,7 +328,7 @@ static bool skx_set_max_freq_ratio(u64 *base_freq, u64 *turbo_freq, int size)
        return false;
 }
 
-static bool core_set_max_freq_ratio(u64 *base_freq, u64 *turbo_freq)
+static bool __init core_set_max_freq_ratio(u64 *base_freq, u64 *turbo_freq)
 {
        u64 msr;
        int err;
@@ -351,7 +351,7 @@ static bool core_set_max_freq_ratio(u64 *base_freq, u64 *turbo_freq)
        return true;
 }
 
-static bool intel_set_max_freq_ratio(void)
+static bool __init intel_set_max_freq_ratio(void)
 {
        u64 base_freq, turbo_freq;
        u64 turbo_ratio;
@@ -418,40 +418,42 @@ static struct syscore_ops freq_invariance_syscore_ops = {
 
 static void register_freq_invariance_syscore_ops(void)
 {
-       /* Bail out if registered already. */
-       if (freq_invariance_syscore_ops.node.prev)
-               return;
-
        register_syscore_ops(&freq_invariance_syscore_ops);
 }
 #else
 static inline void register_freq_invariance_syscore_ops(void) {}
 #endif
 
-void bp_init_freq_invariance(bool cppc_ready)
+static void freq_invariance_enable(void)
+{
+       if (static_branch_unlikely(&arch_scale_freq_key)) {
+               WARN_ON_ONCE(1);
+               return;
+       }
+       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);
+}
+
+void freq_invariance_set_perf_ratio(u64 ratio, bool turbo_disabled)
 {
-       bool ret;
+       arch_turbo_freq_ratio = ratio;
+       arch_set_max_freq_ratio(turbo_disabled);
+       freq_invariance_enable();
+}
 
+void __init bp_init_freq_invariance(void)
+{
        if (!cpu_feature_enabled(X86_FEATURE_APERFMPERF))
                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)
-                       return;
-               ret = amd_set_max_freq_ratio(&arch_turbo_freq_ratio);
-       }
+       if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
+               return;
 
-       if (ret) {
-               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");
-       }
+       if (intel_set_max_freq_ratio())
+               freq_invariance_enable();
 }
 
 void ap_init_freq_invariance(void)

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 023feb40f5c0952b2c281d92a9ffe409a0bffd97..b1ba7ddfe930738d41b9a12df2ded903a3d87144 100644 (file)
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1396,7 +1396,7 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
 {
        smp_prepare_cpus_common();
 
-       bp_init_freq_invariance(false);
+       bp_init_freq_invariance();
        smp_sanity_check();
 
        switch (apic_intr_mode) {