Re: [PATCH 1/4] acpi: intel_idle : break dependency between modules

On Thursday, July 05, 2012, Daniel Lezcano wrote:

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@linaro.org Acked-by: Srivatsa S. Bhat srivatsa.bhat@linux.vnet.ibm.com Acked-by: Rafael J. Wysocki rjw@sisk.pl

OK, I'm taking this one.

Thanks, Rafael

---

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 13103aeb..7048b97 100644 --- a/drivers/acpi/processor_driver.c +++ b/drivers/acpi/processor_driver.c @@ -429,18 +429,11 @@ 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 8684a0d..a6b3f2e 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -207,14 +207,7 @@ 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;}