Hi Daniel,
On 07/27/2013 10:57 AM, Daniel Lezcano wrote:
> On 07/23/2013 11:01 AM, Deepthi Dharwar wrote:
>> This patch implements a back-end cpuidle driver for
>> powernv calling power7_nap and snooze idle states.
>> This can be extended by adding more idle states
>> in the future to the existing framework.
>>
>> Signed-off-by: Deepthi Dharwar <deep...@linux.vnet.ibm.com>
>> ---
>> arch/powerpc/platforms/powernv/Kconfig | 9 +
>> arch/powerpc/platforms/powernv/Makefile | 1
>> arch/powerpc/platforms/powernv/processor_idle.c | 239
>> +++++++++++++++++++++++
>> 3 files changed, 249 insertions(+)
>> create mode 100644 arch/powerpc/platforms/powernv/processor_idle.c
>>
>> diff --git a/arch/powerpc/platforms/powernv/processor_idle.c
>> b/arch/powerpc/platforms/powernv/processor_idle.c
>> new file mode 100644
>> index 0000000..f43ad91a
>> --- /dev/null
>> +++ b/arch/powerpc/platforms/powernv/processor_idle.c
>> @@ -0,0 +1,239 @@
>> +/*
>> + * processor_idle - idle state cpuidle driver.
>> + */
>> +
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/init.h>
>> +#include <linux/moduleparam.h>
>> +#include <linux/cpuidle.h>
>> +#include <linux/cpu.h>
>> +#include <linux/notifier.h>
>> +
>> +#include <asm/machdep.h>
>> +#include <asm/runlatch.h>
>> +
>> +struct cpuidle_driver powernv_idle_driver = {
>> + .name = "powernv_idle",
>> + .owner = THIS_MODULE,
>> +};
>> +
>> +#define MAX_IDLE_STATE_COUNT 2
>> +
>> +static int max_idle_state = MAX_IDLE_STATE_COUNT - 1;
>> +static struct cpuidle_device __percpu *powernv_cpuidle_devices;
>> +static struct cpuidle_state *cpuidle_state_table;
>> +
>> +static int snooze_loop(struct cpuidle_device *dev,
>> + struct cpuidle_driver *drv,
>> + int index)
>> +{
>> + int cpu = dev->cpu;
>> +
>> + local_irq_enable();
>> + set_thread_flag(TIF_POLLING_NRFLAG);
>> +
>> + while ((!need_resched()) && cpu_online(cpu)) {
>> + ppc64_runlatch_off();
>> + HMT_very_low();
>> + }
>
> Why are you using the cpu_online test here ?
>
>> +
>> + HMT_medium();
>> + clear_thread_flag(TIF_POLLING_NRFLAG);
>> + smp_mb();
>> + return index;
>> +}
>> +
>> +
>> +static int nap_loop(struct cpuidle_device *dev,
>> + struct cpuidle_driver *drv,
>> + int index)
>> +{
>> + ppc64_runlatch_off();
>> + power7_idle();
>> + return index;
>> +}
>> +
>> +/*
>> + * States for dedicated partition case.
>> + */
>> +static struct cpuidle_state powernv_states[MAX_IDLE_STATE_COUNT] = {
>> + { /* Snooze */
>> + .name = "snooze",
>> + .desc = "snooze",
>> + .flags = CPUIDLE_FLAG_TIME_VALID,
>> + .exit_latency = 0,
>> + .target_residency = 0,
>> + .enter = &snooze_loop },
>> + { /* Nap */
>> + .name = "Nap",
>> + .desc = "Nap",
>> + .flags = CPUIDLE_FLAG_TIME_VALID,
>> + .exit_latency = 10,
>> + .target_residency = 100,
>> + .enter = &nap_loop },
>> +};
>> +
>> +static int powernv_cpuidle_add_cpu_notifier(struct notifier_block *n,
>> + unsigned long action, void *hcpu)
>> +{
>> + int hotcpu = (unsigned long)hcpu;
>> + struct cpuidle_device *dev =
>> + per_cpu_ptr(powernv_cpuidle_devices, hotcpu);
>> +
>> + if (dev && cpuidle_get_driver()) {
>> + switch (action) {
>> + case CPU_ONLINE:
>> + case CPU_ONLINE_FROZEN:
>> + cpuidle_pause_and_lock();
>> + cpuidle_enable_device(dev);
>> + cpuidle_resume_and_unlock();
>> + break;
>> +
>> + case CPU_DEAD:
>> + case CPU_DEAD_FROZEN:
>> + cpuidle_pause_and_lock();
>> + cpuidle_disable_device(dev);
>> + cpuidle_resume_and_unlock();
>> + break;
>> +
>> + default:
>> + return NOTIFY_DONE;
>> + }
>> + }
>> + return NOTIFY_OK;
>> +}
>> +
>> +static struct notifier_block setup_hotplug_notifier = {
>> + .notifier_call = powernv_cpuidle_add_cpu_notifier,
>> +};
>
> This is duplicated code with the pseries cpuidle driver and IMHO it
> should be moved to the cpuidle framework.
>
Will this not require a cleanup of the hotplug cpuidle notifiers from
other architectures into the cpuidle framework as well?
Regards
Preeti U Murthy
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