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intel_idle: Convert to hotplug state machine 

Install the callbacks via the state machine and let the core invoke the
callbacks on the already online CPUs.

The two smp_call_function_single() invocations in intel_idle_cpu_init() have
been removed because intel_idle_cpu_init() is now invoked via the hotplug
callback which runs on the target CPU. The IRQ-off calling convention for
auto_demotion_disable() and c1e_promotion_disable() has not been preserved
because only those two modify the MSR during CPU intialization.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Sebastian Andrzej Siewior 2016-11-29 10:51:43 +01:00 committed by Rafael J. Wysocki
parent 29d7bbada9
commit fb1013a016
1 changed files with 39 additions and 64 deletions
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103
drivers/idle/intel_idle.c
View File

@ -98,8 +98,6 @@ static int intel_idle(struct cpuidle_device *dev,
struct cpuidle_driver *drv, int index);
static void intel_idle_freeze(struct cpuidle_device *dev,
struct cpuidle_driver *drv, int index);
static int intel_idle_cpu_init(int cpu);
static struct cpuidle_state *cpuidle_state_table;
/*
@ -951,50 +949,15 @@ static void intel_idle_freeze(struct cpuidle_device *dev,
mwait_idle_with_hints(eax, ecx);
}
static void __setup_broadcast_timer(void *arg)
static void __setup_broadcast_timer(bool on)
{
unsigned long on = (unsigned long)arg;
if (on)
tick_broadcast_enable();
else
tick_broadcast_disable();
}
static int cpu_hotplug_notify(struct notifier_block *n,
unsigned long action, void *hcpu)
{
int hotcpu = (unsigned long)hcpu;
struct cpuidle_device *dev;
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_ONLINE:
if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
__setup_broadcast_timer((void *)true);
/*
* Some systems can hotplug a cpu at runtime after
* the kernel has booted, we have to initialize the
* driver in this case
*/
dev = per_cpu_ptr(intel_idle_cpuidle_devices, hotcpu);
if (dev->registered)
break;
if (intel_idle_cpu_init(hotcpu))
return NOTIFY_BAD;
break;
}
return NOTIFY_OK;
}
static struct notifier_block cpu_hotplug_notifier = {
.notifier_call = cpu_hotplug_notify,
};
static void auto_demotion_disable(void *dummy)
static void auto_demotion_disable(void)
{
unsigned long long msr_bits;
@ -1002,7 +965,7 @@ static void auto_demotion_disable(void *dummy)
msr_bits &= ~(icpu->auto_demotion_disable_flags);
wrmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits);
}
static void c1e_promotion_disable(void *dummy)
static void c1e_promotion_disable(void)
{
unsigned long long msr_bits;
@ -1422,12 +1385,11 @@ static void __init intel_idle_cpuidle_driver_init(void)
* allocate, initialize, register cpuidle_devices
* @cpu: cpu/core to initialize
*/
static int intel_idle_cpu_init(int cpu)
static int intel_idle_cpu_init(unsigned int cpu)
{
struct cpuidle_device *dev;
dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
dev->cpu = cpu;
if (cpuidle_register_device(dev)) {
@ -1436,17 +1398,36 @@ static int intel_idle_cpu_init(int cpu)
}
if (icpu->auto_demotion_disable_flags)
smp_call_function_single(cpu, auto_demotion_disable, NULL, 1);
auto_demotion_disable();
if (icpu->disable_promotion_to_c1e)
smp_call_function_single(cpu, c1e_promotion_disable, NULL, 1);
c1e_promotion_disable();
return 0;
}
static int intel_idle_cpu_online(unsigned int cpu)
{
struct cpuidle_device *dev;
if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
__setup_broadcast_timer(true);
/*
* Some systems can hotplug a cpu at runtime after
* the kernel has booted, we have to initialize the
* driver in this case
*/
dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
if (!dev->registered)
return intel_idle_cpu_init(cpu);
return 0;
}
static int __init intel_idle_init(void)
{
int retval, i;
int retval;
/* Do not load intel_idle at all for now if idle= is passed */
if (boot_option_idle_override != IDLE_NO_OVERRIDE)
@ -1466,35 +1447,29 @@ static int __init intel_idle_init(void)
struct cpuidle_driver *drv = cpuidle_get_driver();
printk(KERN_DEBUG PREFIX "intel_idle yielding to %s",
drv ? drv->name : "none");
free_percpu(intel_idle_cpuidle_devices);
return retval;
goto init_driver_fail;
}
cpu_notifier_register_begin();
for_each_online_cpu(i) {
retval = intel_idle_cpu_init(i);
if (retval) {
intel_idle_cpuidle_devices_uninit();
cpu_notifier_register_done();
cpuidle_unregister_driver(&intel_idle_driver);
free_percpu(intel_idle_cpuidle_devices);
return retval;
}
}
__register_cpu_notifier(&cpu_hotplug_notifier);
if (boot_cpu_has(X86_FEATURE_ARAT)) /* Always Reliable APIC Timer */
lapic_timer_reliable_states = LAPIC_TIMER_ALWAYS_RELIABLE;
else
on_each_cpu(__setup_broadcast_timer, (void *)true, 1);
cpu_notifier_register_done();
retval = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "idle/intel:online",
intel_idle_cpu_online, NULL);
if (retval < 0)
goto hp_setup_fail;
pr_debug(PREFIX "lapic_timer_reliable_states 0x%x\n",
lapic_timer_reliable_states);
return 0;
hp_setup_fail:
intel_idle_cpuidle_devices_uninit();
cpuidle_unregister_driver(&intel_idle_driver);
init_driver_fail:
free_percpu(intel_idle_cpuidle_devices);
return retval;
}
device_initcall(intel_idle_init);