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Message-ID: <20161129095143.w6k2ytljvujbuatk@linutronix.de>
Date: Tue, 29 Nov 2016 10:51:43 +0100
From: Sebastian Andrzej Siewior <bigeasy@...utronix.de>
To: Thomas Gleixner <tglx@...utronix.de>
Cc: linux-pm@...r.kernel.org, Len Brown <lenb@...nel.org>,
linux-kernel@...r.kernel.org, rt@...utronix.de
Subject: [PATCH 04/22 v2] idle/intel: 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.
Cc: Len Brown <lenb@...nel.org>
Cc: linux-pm@...r.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@...utronix.de>
---
v1…v2: drop the superfluous saving of the hotplug state (not a module
anymore).
drivers/idle/intel_idle.c | 103 ++++++++++++++++++----------------------------
1 file changed, 39 insertions(+), 64 deletions(-)
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index f53b42a78186..df532c4398e5 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -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;
/*
@@ -907,50 +905,15 @@ 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;
@@ -958,7 +921,7 @@ 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;
@@ -1372,12 +1335,11 @@ 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)) {
@@ -1386,17 +1348,36 @@ 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)
@@ -1416,35 +1397,29 @@ 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);
--
2.10.2
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