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Date: Thu, 28 Jun 2012 10:46:42 +0200
From: Daniel Lezcano <daniel.lezcano@...aro.org>
To: trenn@...e.de
Cc: srivatsa.bhat@...ux.vnet.ibm.com, deepthi@...ux.vnet.ibm.com,
linux-acpi@...r.kernel.org, linux-pm@...ts.linux-foundation.org,
linux-pm@...r.kernel.org, lenb@...nel.org, rjw@...k.pl,
x86@...nel.org, linux-kernel@...r.kernel.org,
linaro-dev@...ts.linaro.org
Subject: [PATCH v2] acpi: intel_idle : break dependency between modules
When the system is booted with some cpus offline, the idle
driver is not initialized. When a cpu is set online, the
acpi code call the intel idle init function. Unfortunately
this code introduce a dependency between intel_idle and acpi.
This patch is intended to remove this dependency by using the
notifier of intel_idle. This patch has the benefit of
encapsulating the intel_idle driver and remove some exported
functions.
Signed-off-by: Daniel Lezcano <daniel.lezcano@...aro.org>
---
drivers/acpi/processor_driver.c | 7 ------
drivers/idle/intel_idle.c | 41 +++++++++++++++++++++++++-------------
include/linux/cpuidle.h | 7 ------
3 files changed, 27 insertions(+), 28 deletions(-)
diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
index 0734086..8648b29 100644
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -427,18 +427,11 @@ static int acpi_cpu_soft_notify(struct notifier_block *nfb,
* 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);
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index d0f59c3..fe95d54 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -96,6 +96,7 @@ static const struct idle_cpu *icpu;
static struct cpuidle_device __percpu *intel_idle_cpuidle_devices;
static int intel_idle(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;
@@ -302,22 +303,35 @@ static void __setup_broadcast_timer(void *arg)
clockevents_notify(reason, &cpu);
}
-static int setup_broadcast_cpuhp_notify(struct notifier_block *n,
- unsigned long action, void *hcpu)
+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 & 0xf) {
case CPU_ONLINE:
- smp_call_function_single(hotcpu, __setup_broadcast_timer,
- (void *)true, 1);
+
+ if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
+ smp_call_function_single(hotcpu, __setup_broadcast_timer,
+ (void *)true, 1);
+
+ /*
+ * 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)
+ intel_idle_cpu_init(hotcpu);
+
break;
}
return NOTIFY_OK;
}
-static struct notifier_block setup_broadcast_notifier = {
- .notifier_call = setup_broadcast_cpuhp_notify,
+static struct notifier_block cpu_hotplug_notifier = {
+ .notifier_call = cpu_hotplug_notify,
};
static void auto_demotion_disable(void *dummy)
@@ -405,10 +419,10 @@ static int intel_idle_probe(void)
if (boot_cpu_has(X86_FEATURE_ARAT)) /* Always Reliable APIC Timer */
lapic_timer_reliable_states = LAPIC_TIMER_ALWAYS_RELIABLE;
- else {
+ else
on_each_cpu(__setup_broadcast_timer, (void *)true, 1);
- register_cpu_notifier(&setup_broadcast_notifier);
- }
+
+ register_cpu_notifier(&cpu_hotplug_notifier);
pr_debug(PREFIX "v" INTEL_IDLE_VERSION
" model 0x%X\n", boot_cpu_data.x86_model);
@@ -494,7 +508,7 @@ static int intel_idle_cpuidle_driver_init(void)
* allocate, initialize, register cpuidle_devices
* @cpu: cpu/core to initialize
*/
-int intel_idle_cpu_init(int cpu)
+static int intel_idle_cpu_init(int cpu)
{
int cstate;
struct cpuidle_device *dev;
@@ -539,7 +553,6 @@ int intel_idle_cpu_init(int cpu)
return 0;
}
-EXPORT_SYMBOL_GPL(intel_idle_cpu_init);
static int __init intel_idle_init(void)
{
@@ -581,10 +594,10 @@ static void __exit intel_idle_exit(void)
intel_idle_cpuidle_devices_uninit();
cpuidle_unregister_driver(&intel_idle_driver);
- if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE) {
+
+ if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
on_each_cpu(__setup_broadcast_timer, (void *)false, 1);
- unregister_cpu_notifier(&setup_broadcast_notifier);
- }
+ unregister_cpu_notifier(&cpu_hotplug_notifier);
return;
}
diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index 5ab7183..66d7e0d 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -213,14 +213,7 @@ struct cpuidle_governor {
extern int cpuidle_register_governor(struct cpuidle_governor *gov);
extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
-#ifdef CONFIG_INTEL_IDLE
-extern int intel_idle_cpu_init(int cpu);
#else
-static inline int intel_idle_cpu_init(int cpu) { return -1; }
-#endif
-
-#else
-static inline int intel_idle_cpu_init(int cpu) { return -1; }
static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
{return 0;}
--
1.7.5.4
--
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