cpufreq: acpi-cpufreq: Convert to hotplug state machine

Install the callbacks via the state machine.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 45 insertions, 47 deletions

diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
index 297e9128fe9f..52b25f2356f2 100644
--- a/drivers/cpufreq/acpi-cpufreq.c
+++ b/drivers/cpufreq/acpi-cpufreq.c
@@ -536,46 +536,33 @@ static void free_acpi_perf_data(void)
         free_percpu(acpi_perf_data);
 }
 
-static int boost_notify(struct notifier_block *nb, unsigned long action,
-                      void *hcpu)
+static int cpufreq_boost_online(unsigned int cpu)
 {
-        unsigned cpu = (long)hcpu;
         const struct cpumask *cpumask;
 
         cpumask = get_cpu_mask(cpu);
-
         /*
-         * Clear the boost-disable bit on the CPU_DOWN path so that
-         * this cpu cannot block the remaining ones from boosting. On
-         * the CPU_UP path we simply keep the boost-disable flag in
-         * sync with the current global state.
+         * On the CPU_UP path we simply keep the boost-disable flag
+         * in sync with the current global state.
          */
+        boost_set_msrs(acpi_cpufreq_driver.boost_enabled, cpumask);
+        return 0;
+}
 
-        switch (action) {
-        case CPU_DOWN_FAILED:
-        case CPU_DOWN_FAILED_FROZEN:
-        case CPU_ONLINE:
-        case CPU_ONLINE_FROZEN:
-                boost_set_msrs(acpi_cpufreq_driver.boost_enabled, cpumask);
-                break;
-
-        case CPU_DOWN_PREPARE:
-        case CPU_DOWN_PREPARE_FROZEN:
-                boost_set_msrs(1, cpumask);
-                break;
+static int cpufreq_boost_down_prep(unsigned int cpu)
+{
+        const struct cpumask *cpumask;
 
-        default:
-                break;
-        }
+        cpumask = get_cpu_mask(cpu);
 
-        return NOTIFY_OK;
+        /*
+         * Clear the boost-disable bit on the CPU_DOWN path so that
+         * this cpu cannot block the remaining ones from boosting.
+         */
+        boost_set_msrs(1, cpumask);
+        return 0;
 }
 
-
-static struct notifier_block boost_nb = {
-        .notifier_call          = boost_notify,
-};
-
 /*
  * acpi_cpufreq_early_init - initialize ACPI P-States library
  *
@@ -922,37 +909,48 @@ static struct cpufreq_driver acpi_cpufreq_driver = {
         .attr           = acpi_cpufreq_attr,
 };
 
+static enum cpuhp_state acpi_cpufreq_online;
+
 static void __init acpi_cpufreq_boost_init(void)
 {
-        if (boot_cpu_has(X86_FEATURE_CPB) || boot_cpu_has(X86_FEATURE_IDA)) {
-                msrs = msrs_alloc();
-
-                if (!msrs)
-                        return;
+        int ret;
 
-                acpi_cpufreq_driver.set_boost = set_boost;
-                acpi_cpufreq_driver.boost_enabled = boost_state(0);
+        if (!(boot_cpu_has(X86_FEATURE_CPB) || boot_cpu_has(X86_FEATURE_IDA)))
+                return;
 
-                cpu_notifier_register_begin();
+        msrs = msrs_alloc();
 
-                /* Force all MSRs to the same value */
-                boost_set_msrs(acpi_cpufreq_driver.boost_enabled,
-                               cpu_online_mask);
+        if (!msrs)
+                return;
 
-                __register_cpu_notifier(&boost_nb);
+        acpi_cpufreq_driver.set_boost = set_boost;
+        acpi_cpufreq_driver.boost_enabled = boost_state(0);
 
-                cpu_notifier_register_done();
+        /*
+         * This calls the online callback on all online cpu and forces all
+         * MSRs to the same value.
+         */
+        ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "cpufreq/acpi:online",
+                                cpufreq_boost_online, cpufreq_boost_down_prep);
+        if (ret < 0) {
+                pr_err("acpi_cpufreq: failed to register hotplug callbacks\n");
+                msrs_free(msrs);
+                msrs = NULL;
+                return;
         }
+        acpi_cpufreq_online = ret;
 }
 
 static void acpi_cpufreq_boost_exit(void)
 {
-        if (msrs) {
-                unregister_cpu_notifier(&boost_nb);
+        if (!msrs)
+                return;
 
-                msrs_free(msrs);
-                msrs = NULL;
-        }
+        if (acpi_cpufreq_online >= 0)
+                cpuhp_remove_state_nocalls(acpi_cpufreq_online);
+
+        msrs_free(msrs);
+        msrs = NULL;
 }
 
 static int __init acpi_cpufreq_init(void)