linux-kernel - Re: [PATCH 3/6] drivers: firmware: psci: Decouple checker from generic ARM CPUidle

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Date:   Wed, 7 Aug 2019 16:09:55 +0200
From:   Daniel Lezcano <daniel.lezcano@...aro.org>
To:     Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
        linux-pm@...r.kernel.org
Cc:     Sudeep Holla <sudeep.holla@....com>,
        Mark Rutland <mark.rutland@....com>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        "Rafael J. Wysocki" <rjw@...ysocki.net>,
        LKML <linux-kernel@...r.kernel.org>,
        LAKML <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH 3/6] drivers: firmware: psci: Decouple checker from
 generic ARM CPUidle

On 22/07/2019 17:37, Lorenzo Pieralisi wrote:
> The PSCI checker currently relies on the generic ARM CPUidle
> infrastructure to enter an idle state, which in turn creates
> a dependency that is not really needed.
> 
> The PSCI checker code to test PSCI CPU suspend is built on
> top of the CPUidle framework and can easily reuse the
> struct cpuidle_state.enter() function (previously initialized
> by an idle driver, with a PSCI back-end) to trigger an entry
> into an idle state, decoupling the PSCI checker from the
> generic ARM CPUidle infrastructure and simplyfing the code
> in the process.
> 
> Convert the PSCI checker suspend entry function to use
> the struct cpuidle_state.enter() function callback.
> 
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@....com>
> Cc: Sudeep Holla <sudeep.holla@....com>
> Cc: Mark Rutland <mark.rutland@....com>

Acked-by: Daniel Lezcano <daniel.lezcano@...aro.org>

> ---
>  drivers/firmware/psci/psci_checker.c | 16 +++++++---------
>  1 file changed, 7 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/firmware/psci/psci_checker.c b/drivers/firmware/psci/psci_checker.c
> index f3659443f8c2..6a445397771c 100644
> --- a/drivers/firmware/psci/psci_checker.c
> +++ b/drivers/firmware/psci/psci_checker.c
> @@ -228,8 +228,11 @@ static int hotplug_tests(void)
>  
>  static void dummy_callback(struct timer_list *unused) {}
>  
> -static int suspend_cpu(int index, bool broadcast)
> +static int suspend_cpu(struct cpuidle_device *dev,
> +		       struct cpuidle_driver *drv, int index)
>  {
> +	struct cpuidle_state *state = &drv->states[index];
> +	bool broadcast = state->flags & CPUIDLE_FLAG_TIMER_STOP;
>  	int ret;
>  
>  	arch_cpu_idle_enter();
> @@ -254,11 +257,7 @@ static int suspend_cpu(int index, bool broadcast)
>  		}
>  	}
>  
> -	/*
> -	 * Replicate the common ARM cpuidle enter function
> -	 * (arm_enter_idle_state).
> -	 */
> -	ret = CPU_PM_CPU_IDLE_ENTER(arm_cpuidle_suspend, index);
> +	ret = state->enter(dev, drv, index);
>  
>  	if (broadcast)
>  		tick_broadcast_exit();
> @@ -301,9 +300,8 @@ static int suspend_test_thread(void *arg)
>  		 * doesn't use PSCI).
>  		 */
>  		for (index = 1; index < drv->state_count; ++index) {
> -			struct cpuidle_state *state = &drv->states[index];
> -			bool broadcast = state->flags & CPUIDLE_FLAG_TIMER_STOP;
>  			int ret;
> +			struct cpuidle_state *state = &drv->states[index];
>  
>  			/*
>  			 * Set the timer to wake this CPU up in some time (which
> @@ -318,7 +316,7 @@ static int suspend_test_thread(void *arg)
>  			/* IRQs must be disabled during suspend operations. */
>  			local_irq_disable();
>  
> -			ret = suspend_cpu(index, broadcast);
> +			ret = suspend_cpu(dev, drv, index);
>  
>  			/*
>  			 * We have woken up. Re-enable IRQs to handle any
> 


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