From: Thomas Renninger <trenn@xxxxxxx>
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 <trenn@xxxxxxx>
Signed-off-by: Len Brown <len.brown@xxxxxxxxx>
---
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 bec5593..2b805d7 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 20bce51..54ab97b 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 610f6fb..8cf7e98 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 {
--
1.7.9.rc2
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