[PATCH 1/2] ARM: EXYNOS4: convert MCT to percpu interrupt API

[Kukjin Kim]

Marc Zyngier wrote:
> 
> MCT recently gained per cpu interrupts, and missed the fact that
> ARM has moved to a genirq based implementation.
> 
> This patch converts the driver to the new API.
> 
> Boot tested on Origen.
> 
> Cc: Kukjin Kim <kgene.kim at samsung.com>
> Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
> ---
>  arch/arm/mach-exynos4/mct.c |   40 +++++++++++++++++++++++++++-----------
> --
>  1 files changed, 27 insertions(+), 13 deletions(-)
> 
> diff --git a/arch/arm/mach-exynos4/mct.c b/arch/arm/mach-exynos4/mct.c
> index f191608..97343df 100644
> --- a/arch/arm/mach-exynos4/mct.c
> +++ b/arch/arm/mach-exynos4/mct.c
> @@ -44,7 +44,7 @@ struct mct_clock_event_device {
>  	char name[10];
>  };
> 
> -struct mct_clock_event_device mct_tick[NR_CPUS];
> +static DEFINE_PER_CPU(struct mct_clock_event_device, percpu_mct_tick);
> 
>  static void exynos4_mct_write(unsigned int value, void *addr)
>  {
> @@ -302,7 +302,7 @@ static void exynos4_mct_tick_start(unsigned long
cycles,
>  static int exynos4_tick_set_next_event(unsigned long cycles,
>  				       struct clock_event_device *evt)
>  {
> -	struct mct_clock_event_device *mevt = &mct_tick[smp_processor_id()];
> +	struct mct_clock_event_device *mevt =
this_cpu_ptr(&percpu_mct_tick);
> 
>  	exynos4_mct_tick_start(cycles, mevt);
> 
> @@ -312,7 +312,7 @@ static int exynos4_tick_set_next_event(unsigned long
> cycles,
>  static inline void exynos4_tick_set_mode(enum clock_event_mode mode,
>  					 struct clock_event_device *evt)
>  {
> -	struct mct_clock_event_device *mevt = &mct_tick[smp_processor_id()];
> +	struct mct_clock_event_device *mevt =
this_cpu_ptr(&percpu_mct_tick);
> 
>  	exynos4_mct_tick_stop(mevt);
> 
> @@ -376,14 +376,16 @@ static struct irqaction mct_tick1_event_irq = {
> 
>  static void exynos4_mct_tick_init(struct clock_event_device *evt)
>  {
> +	struct mct_clock_event_device *mevt;
>  	unsigned int cpu = smp_processor_id();
> 
> -	mct_tick[cpu].evt = evt;
> +	mevt = this_cpu_ptr(&percpu_mct_tick);
> +	mevt->evt = evt;
> 
> -	mct_tick[cpu].base = EXYNOS4_MCT_L_BASE(cpu);
> -	sprintf(mct_tick[cpu].name, "mct_tick%d", cpu);
> +	mevt->base = EXYNOS4_MCT_L_BASE(cpu);
> +	sprintf(mevt->name, "mct_tick%d", cpu);
> 
> -	evt->name = mct_tick[cpu].name;
> +	evt->name = mevt->name;
>  	evt->cpumask = cpumask_of(cpu);
>  	evt->set_next_event = exynos4_tick_set_next_event;
>  	evt->set_mode = exynos4_tick_set_mode;
> @@ -398,21 +400,21 @@ static void exynos4_mct_tick_init(struct
> clock_event_device *evt)
> 
>  	clockevents_register_device(evt);
> 
> -	exynos4_mct_write(0x1, mct_tick[cpu].base + MCT_L_TCNTB_OFFSET);
> +	exynos4_mct_write(0x1, mevt->base + MCT_L_TCNTB_OFFSET);
> 
>  	if (mct_int_type == MCT_INT_SPI) {
>  		if (cpu == 0) {
> -			mct_tick0_event_irq.dev_id = &mct_tick[cpu];
> +			mct_tick0_event_irq.dev_id = mevt;
>  			evt->irq = IRQ_MCT_L0;
>  			setup_irq(IRQ_MCT_L0, &mct_tick0_event_irq);
>  		} else {
> -			mct_tick1_event_irq.dev_id = &mct_tick[cpu];
> +			mct_tick1_event_irq.dev_id = mevt;
>  			evt->irq = IRQ_MCT_L1;
>  			setup_irq(IRQ_MCT_L1, &mct_tick1_event_irq);
>  			irq_set_affinity(IRQ_MCT_L1, cpumask_of(1));
>  		}
>  	} else {
> -		gic_enable_ppi(IRQ_MCT_LOCALTIMER);
> +		enable_percpu_irq(IRQ_MCT_LOCALTIMER, 0);
>  	}
>  }
> 
> @@ -427,9 +429,11 @@ int __cpuinit local_timer_setup(struct
clock_event_device
> *evt)
>  void local_timer_stop(struct clock_event_device *evt)
>  {
>  	evt->set_mode(CLOCK_EVT_MODE_UNUSED, evt);
> -	disable_irq(evt->irq);
> +	if (mct_int_type == MCT_INT_SPI)
> +		disable_irq(evt->irq);
> +	else
> +		disable_percpu_irq(IRQ_MCT_LOCALTIMER);
>  }
> -
>  #endif /* CONFIG_LOCAL_TIMERS */
> 
>  static void __init exynos4_timer_resources(void)
> @@ -438,6 +442,16 @@ static void __init exynos4_timer_resources(void)
>  	mct_clk = clk_get(NULL, "xtal");
> 
>  	clk_rate = clk_get_rate(mct_clk);
> +
> +	if (mct_int_type == MCT_INT_PPI) {
> +		int err;
> +
> +		err = request_percpu_irq(IRQ_MCT_LOCALTIMER,
> +					 exynos4_mct_tick_isr, "MCT",
> +					 &percpu_mct_tick);
> +		WARN(err, "MCT: can't request IRQ %d (%d)\n",
> +		     IRQ_MCT_LOCALTIMER, err);
> +	}
>  }
> 
>  static void __init exynos4_timer_init(void)
> --
> 1.7.0.4

Hi Marc,

It works fine on SMDKV310 and SMDK4X12.
I will pick this up in Samsung tree and it will be sent to Arnd for this
merge window soon.

Thanks.

Best regards,
Kgene.
--
Kukjin Kim <kgene.kim at samsung.com>, Senior Engineer,
SW Solution Development Team, Samsung Electronics Co., Ltd.