Install the callbacks via the state machine and let the core invoke the callbacks on the already online CPUs. Replace the wrmsr/rdmrs_on_cpu() calls in the hotplug callbacks as they are guaranteed to be invoked on the incoming/outgoing cpu. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner --- drivers/thermal/x86_pkg_temp_thermal.c | 81 +++++++++------------------------ 1 file changed, 24 insertions(+), 57 deletions(-) --- a/drivers/thermal/x86_pkg_temp_thermal.c +++ b/drivers/thermal/x86_pkg_temp_thermal.c @@ -78,6 +78,9 @@ static DEFINE_SPINLOCK(pkg_temp_lock); /* Protects zone operation in the work function against hotplug removal */ static DEFINE_MUTEX(thermal_zone_mutex); +/* The dynamically assigned cpu hotplug state for module_exit() */ +static enum cpuhp_state pkg_thermal_hp_state __read_mostly; + /* Debug counters to show using debugfs */ static struct dentry *debugfs; static unsigned int pkg_interrupt_cnt; @@ -385,9 +388,8 @@ static int pkg_temp_thermal_device_add(u return err; } /* Store MSR value for package thermal interrupt, to restore at exit */ - rdmsr_on_cpu(cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT, - &pkgdev->msr_pkg_therm_low, - &pkgdev->msr_pkg_therm_high); + rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, pkgdev->msr_pkg_therm_low, + pkgdev->msr_pkg_therm_high); spin_lock_irq(&pkg_temp_lock); packages[pkgid] = pkgdev; @@ -395,16 +397,17 @@ static int pkg_temp_thermal_device_add(u return 0; } -static void put_core_offline(unsigned int cpu) +static int pkg_thermal_cpu_offline(unsigned int cpu) { int target = cpumask_any_but(topology_core_cpumask(cpu), cpu); struct pkg_device *pkgdev = pkg_temp_thermal_get_dev(cpu); bool lastcpu, was_target; if (!pkgdev) - return; + return 0; lastcpu = target >= nr_cpu_ids; + /* * Remove the sysfs files, if this is the last cpu in the package * before doing further cleanups. @@ -444,16 +447,9 @@ static void put_core_offline(unsigned in */ if (lastcpu) { packages[topology_logical_package_id(cpu)] = NULL; - /* - * After this point nothing touches the MSR anymore. We - * must drop the lock to make the cross cpu call. This goes - * away once we move that code to the hotplug state machine. - */ - spin_unlock_irq(&pkg_temp_lock); - wrmsr_on_cpu(cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT, - pkgdev->msr_pkg_therm_low, - pkgdev->msr_pkg_therm_high); - spin_lock_irq(&pkg_temp_lock); + /* After this point nothing touches the MSR anymore. */ + wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, + pkgdev->msr_pkg_therm_low, pkgdev->msr_pkg_therm_high); } /* @@ -483,9 +479,10 @@ static void put_core_offline(unsigned in /* Final cleanup if this is the last cpu */ if (lastcpu) kfree(pkgdev); + return 0; } -static int get_core_online(unsigned int cpu) +static int pkg_thermal_cpu_online(unsigned int cpu) { struct pkg_device *pkgdev = pkg_temp_thermal_get_dev(cpu); struct cpuinfo_x86 *c = &cpu_data(cpu); @@ -500,27 +497,6 @@ static int get_core_online(unsigned int return pkg_temp_thermal_device_add(cpu); } -static int pkg_temp_thermal_cpu_callback(struct notifier_block *nfb, - unsigned long action, void *hcpu) -{ - unsigned int cpu = (unsigned long) hcpu; - - switch (action & ~CPU_TASKS_FROZEN) { - case CPU_ONLINE: - case CPU_DOWN_FAILED: - get_core_online(cpu); - break; - case CPU_DOWN_PREPARE: - put_core_offline(cpu); - break; - } - return NOTIFY_OK; -} - -static struct notifier_block pkg_temp_thermal_notifier __refdata = { - .notifier_call = pkg_temp_thermal_cpu_callback, -}; - static const struct x86_cpu_id __initconst pkg_temp_thermal_ids[] = { { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, X86_FEATURE_PTS }, {} @@ -529,7 +505,7 @@ MODULE_DEVICE_TABLE(x86cpu, pkg_temp_the static int __init pkg_temp_thermal_init(void) { - int i; + int ret; if (!x86_match_cpu(pkg_temp_thermal_ids)) return -ENODEV; @@ -539,12 +515,13 @@ static int __init pkg_temp_thermal_init( if (!packages) return -ENOMEM; - cpu_notifier_register_begin(); - for_each_online_cpu(i) - if (get_core_online(i)) - goto err_ret; - __register_hotcpu_notifier(&pkg_temp_thermal_notifier); - cpu_notifier_register_done(); + ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "thermal/x86_pkg:online", + pkg_thermal_cpu_online, pkg_thermal_cpu_offline); + if (ret < 0) + goto err; + + /* Store the state for module exit */ + pkg_thermal_hp_state = ret; platform_thermal_package_notify = pkg_thermal_notify; platform_thermal_package_rate_control = pkg_thermal_rate_control; @@ -553,28 +530,18 @@ static int __init pkg_temp_thermal_init( pkg_temp_debugfs_init(); return 0; -err_ret: - for_each_online_cpu(i) - put_core_offline(i); - cpu_notifier_register_done(); +err: kfree(packages); - return -ENODEV; + return ret; } module_init(pkg_temp_thermal_init) static void __exit pkg_temp_thermal_exit(void) { - int i; - platform_thermal_package_notify = NULL; platform_thermal_package_rate_control = NULL; - cpu_notifier_register_begin(); - __unregister_hotcpu_notifier(&pkg_temp_thermal_notifier); - for_each_online_cpu(i) - put_core_offline(i); - cpu_notifier_register_done(); - + cpuhp_remove_state(pkg_thermal_hp_state); debugfs_remove_recursive(debugfs); kfree(packages); }