From 99b725084450bbc6f8e1ab20a0df4cc291c342b5 Mon Sep 17 00:00:00 2001 From: Thomas Renninger Date: Thu, 19 Jan 2012 18:18:43 +0100 Subject: [PATCH] ACPI processor hotplug: Delay acpi_processor_start() call for hotplugged cores Delay the setting up of features (cpuidle, throttling by calling acpi_processor_start()) to the time when the hotplugged core got onlined the first time and got fully initialized. Signed-off-by: Thomas Renninger Signed-off-by: Len Brown --- drivers/acpi/processor_driver.c | 72 +++++++++++++++++++++++++++++---- drivers/idle/intel_idle.c | 2 +- include/acpi/processor.h | 1 + 3 files changed, 67 insertions(+), 8 deletions(-) diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c index bec55937cf10..2b805d7ef317 100644 --- a/drivers/acpi/processor_driver.c +++ b/drivers/acpi/processor_driver.c @@ -84,7 +84,7 @@ static int acpi_processor_remove(struct acpi_device *device, int type); static void acpi_processor_notify(struct acpi_device *device, u32 event); static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr); static int acpi_processor_handle_eject(struct acpi_processor *pr); - +static int acpi_processor_start(struct acpi_processor *pr); static const struct acpi_device_id processor_device_ids[] = { {ACPI_PROCESSOR_OBJECT_HID, 0}, @@ -423,10 +423,29 @@ static int acpi_cpu_soft_notify(struct notifier_block *nfb, struct acpi_processor *pr = per_cpu(processors, cpu); if (action == CPU_ONLINE && pr) { - acpi_processor_ppc_has_changed(pr, 0); - acpi_processor_hotplug(pr); - acpi_processor_reevaluate_tstate(pr, action); - acpi_processor_tstate_has_changed(pr); + /* CPU got physically hotplugged and onlined the first time: + * Initialize missing things + */ + if (pr->flags.need_hotplug_init) { + struct cpuidle_driver *idle_driver = + cpuidle_get_driver(); + + printk(KERN_INFO "Will online and init hotplugged " + "CPU: %d\n", pr->id); + WARN(acpi_processor_start(pr), "Failed to start CPU:" + " %d\n", pr->id); + pr->flags.need_hotplug_init = 0; + if (idle_driver && !strcmp(idle_driver->name, + "intel_idle")) { + intel_idle_cpu_init(pr->id); + } + /* Normal CPU soft online event */ + } else { + acpi_processor_ppc_has_changed(pr, 0); + acpi_processor_cst_has_changed(pr); + acpi_processor_reevaluate_tstate(pr, action); + acpi_processor_tstate_has_changed(pr); + } } if (action == CPU_DEAD && pr) { /* invalidate the flag.throttling after one CPU is offline */ @@ -440,7 +459,15 @@ static struct notifier_block acpi_cpu_notifier = .notifier_call = acpi_cpu_soft_notify, }; -static int __cpuinit acpi_processor_start(struct acpi_processor *pr) +/* + * acpi_processor_start() is called by the cpu_hotplug_notifier func: + * acpi_cpu_soft_notify(). Getting it __cpuinit{data} is difficult, the + * root cause seem to be that acpi_processor_uninstall_hotplug_notify() + * is in the module_exit (__exit) func. Allowing acpi_processor_start() + * to not be in __cpuinit section, but being called from __cpuinit funcs + * via __ref looks like the right thing to do here. + */ +static __ref int acpi_processor_start(struct acpi_processor *pr) { struct acpi_device *device = per_cpu(processor_device_array, pr->id); int result = 0; @@ -491,7 +518,12 @@ err_power_exit: return result; } - +/* + * Do not put anything in here which needs the core to be online. + * For example MSR access or setting up things which check for cpuinfo_x86 + * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc. + * Such things have to be put in and set up above in acpi_processor_start() + */ static int __cpuinit acpi_processor_add(struct acpi_device *device) { struct acpi_processor *pr = NULL; @@ -546,6 +578,21 @@ static int __cpuinit acpi_processor_add(struct acpi_device *device) result = -EFAULT; goto err_free_cpumask; } + + /* + * Do not start hotplugged CPUs now, but when they + * are onlined the first time + */ + if (pr->flags.need_hotplug_init) + return 0; + + /* + * Do not start hotplugged CPUs now, but when they + * are onlined the first time + */ + if (pr->flags.need_hotplug_init) + return 0; + result = acpi_processor_start(pr); if (result) goto err_remove_sysfs; @@ -751,6 +798,17 @@ static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr) return AE_ERROR; } + /* CPU got hot-plugged, but cpu_data is not initialized yet + * Set flag to delay cpu_idle/throttling initialization + * in: + * acpi_processor_add() + * acpi_processor_get_info() + * and do it when the CPU gets online the first time + * TBD: Cleanup above functions and try to do this more elegant. + */ + printk(KERN_INFO "CPU %d got hotplugged\n", pr->id); + pr->flags.need_hotplug_init = 1; + return AE_OK; } diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index 20bce51c2e82..54ab97bae042 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -527,7 +527,7 @@ int intel_idle_cpu_init(int cpu) return 0; } - +EXPORT_SYMBOL_GPL(intel_idle_cpu_init); static int __init intel_idle_init(void) { diff --git a/include/acpi/processor.h b/include/acpi/processor.h index 610f6fb1bbc2..8cf7e98a2c7b 100644 --- a/include/acpi/processor.h +++ b/include/acpi/processor.h @@ -195,6 +195,7 @@ struct acpi_processor_flags { u8 has_cst:1; u8 power_setup_done:1; u8 bm_rld_set:1; + u8 need_hotplug_init:1; }; struct acpi_processor { -- 2.20.1