[PATCH V8 1/3] irq: Add flags to request_percpu_irq function

[PATCH V8 1/3] irq: Add flags to request_percpu_irq function

[Daniel Lezcano]

In the next changes, we track the interrupts but we discard the timers as
that does not make sense. The next interrupt on a timer is predictable.

But, the API request_percpu_irq does not allow to pass a flag, hence specifying
if the interrupt type is a timer.

Solve this by passing a 'flags' parameter to the function and change all the
callers to pass IRQF_TIMER when the interrupt is a timer interrupt, zero
otherwise.

For now, in order to prevent a misusage of this parameter, only the IRQF_TIMER
flag is a valid parameter to be passed to the request_percpu_irq function.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 arch/arc/kernel/perf_event.c             |  2 +-
 arch/arc/kernel/smp.c                    |  2 +-
 arch/arm/kernel/smp_twd.c                |  3 ++-
 arch/arm/xen/enlighten.c                 |  2 +-
 drivers/clocksource/arc_timer.c          |  2 +-
 drivers/clocksource/arm_arch_timer.c     | 15 +++++++++------
 drivers/clocksource/arm_global_timer.c   |  2 +-
 drivers/clocksource/exynos_mct.c         |  2 +-
 drivers/clocksource/qcom-timer.c         |  2 +-
 drivers/clocksource/time-armada-370-xp.c |  2 +-
 drivers/clocksource/timer-nps.c          |  2 +-
 drivers/net/ethernet/marvell/mvneta.c    |  2 +-
 drivers/perf/arm_pmu.c                   |  2 +-
 include/linux/interrupt.h                |  5 +++--
 kernel/irq/manage.c                      | 11 ++++++++---
 virt/kvm/arm/arch_timer.c                |  5 +++--
 virt/kvm/arm/vgic/vgic-init.c            |  2 +-
 17 files changed, 37 insertions(+), 26 deletions(-)

diff --git a/arch/arc/kernel/perf_event.c b/arch/arc/kernel/perf_event.c
index 2ce24e7..2a90c7a 100644
--- a/arch/arc/kernel/perf_event.c
+++ b/arch/arc/kernel/perf_event.c
@@ -525,7 +525,7 @@ static int arc_pmu_device_probe(struct platform_device *pdev)
 		arc_pmu->irq = irq;
 
 		/* intc map function ensures irq_set_percpu_devid() called */
-		request_percpu_irq(irq, arc_pmu_intr, "ARC perf counters",
+		request_percpu_irq(irq, 0, arc_pmu_intr, "ARC perf counters",
 				   this_cpu_ptr(&arc_pmu_cpu));
 
 		on_each_cpu(arc_cpu_pmu_irq_init, &irq, 1);
diff --git a/arch/arc/kernel/smp.c b/arch/arc/kernel/smp.c
index f462671..5cdd3c9 100644
--- a/arch/arc/kernel/smp.c
+++ b/arch/arc/kernel/smp.c
@@ -381,7 +381,7 @@ int smp_ipi_irq_setup(int cpu, irq_hw_number_t hwirq)
 	if (!cpu) {
 		int rc;
 
-		rc = request_percpu_irq(virq, do_IPI, "IPI Interrupt", dev);
+		rc = request_percpu_irq(virq, 0, do_IPI, "IPI Interrupt", dev);
 		if (rc)
 			panic("Percpu IRQ request failed for %u\n", virq);
 	}
diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c
index 895ae51..988f9b9 100644
--- a/arch/arm/kernel/smp_twd.c
+++ b/arch/arm/kernel/smp_twd.c
@@ -332,7 +332,8 @@ static int __init twd_local_timer_common_register(struct device_node *np)
 		goto out_free;
 	}
 
-	err = request_percpu_irq(twd_ppi, twd_handler, "twd", twd_evt);
+	err = request_percpu_irq(twd_ppi, IRQF_TIMER, twd_handler, "twd",
+				 twd_evt);
 	if (err) {
 		pr_err("twd: can't register interrupt %d (%d)\n", twd_ppi, err);
 		goto out_free;
diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 81e3217..2897f94 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -400,7 +400,7 @@ static int __init xen_guest_init(void)
 
 	xen_init_IRQ();
 
-	if (request_percpu_irq(xen_events_irq, xen_arm_callback,
+	if (request_percpu_irq(xen_events_irq, 0, xen_arm_callback,
 			       "events", &xen_vcpu)) {
 		pr_err("Error request IRQ %d\n", xen_events_irq);
 		return -EINVAL;
diff --git a/drivers/clocksource/arc_timer.c b/drivers/clocksource/arc_timer.c
index 7517f95..e78e306 100644
--- a/drivers/clocksource/arc_timer.c
+++ b/drivers/clocksource/arc_timer.c
@@ -301,7 +301,7 @@ static int __init arc_clockevent_setup(struct device_node *node)
 	}
 
 	/* Needs apriori irq_set_percpu_devid() done in intc map function */
-	ret = request_percpu_irq(arc_timer_irq, timer_irq_handler,
+	ret = request_percpu_irq(arc_timer_irq, IRQF_TIMER, timer_irq_handler,
 				 "Timer0 (per-cpu-tick)", evt);
 	if (ret) {
 		pr_err("clockevent: unable to request irq\n");
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 7a8a411..11398ff 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -768,16 +768,19 @@ static int __init arch_timer_register(void)
 	ppi = arch_timer_ppi[arch_timer_uses_ppi];
 	switch (arch_timer_uses_ppi) {
 	case VIRT_PPI:
-		err = request_percpu_irq(ppi, arch_timer_handler_virt,
-					 "arch_timer", arch_timer_evt);
+		err = request_percpu_irq(ppi, IRQF_TIMER,
+					 arch_timer_handler_virt, "arch_timer",
+					 arch_timer_evt);
 		break;
 	case PHYS_SECURE_PPI:
 	case PHYS_NONSECURE_PPI:
-		err = request_percpu_irq(ppi, arch_timer_handler_phys,
-					 "arch_timer", arch_timer_evt);
+		err = request_percpu_irq(ppi, IRQF_TIMER,
+					 arch_timer_handler_phys, "arch_timer",
+					 arch_timer_evt);
 		if (!err && arch_timer_ppi[PHYS_NONSECURE_PPI]) {
 			ppi = arch_timer_ppi[PHYS_NONSECURE_PPI];
-			err = request_percpu_irq(ppi, arch_timer_handler_phys,
+			err = request_percpu_irq(ppi, IRQF_TIMER,
+						 arch_timer_handler_phys,
 						 "arch_timer", arch_timer_evt);
 			if (err)
 				free_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI],
@@ -785,7 +788,7 @@ static int __init arch_timer_register(void)
 		}
 		break;
 	case HYP_PPI:
-		err = request_percpu_irq(ppi, arch_timer_handler_phys,
+		err = request_percpu_irq(ppi, IRQF_TIMER, arch_timer_handler_phys,
 					 "arch_timer", arch_timer_evt);
 		break;
 	default:
diff --git a/drivers/clocksource/arm_global_timer.c b/drivers/clocksource/arm_global_timer.c
index 123ed20..1262d50 100644
--- a/drivers/clocksource/arm_global_timer.c
+++ b/drivers/clocksource/arm_global_timer.c
@@ -302,7 +302,7 @@ static int __init global_timer_of_register(struct device_node *np)
 		goto out_clk;
 	}
 
-	err = request_percpu_irq(gt_ppi, gt_clockevent_interrupt,
+	err = request_percpu_irq(gt_ppi, IRQF_TIMER, gt_clockevent_interrupt,
 				 "gt", gt_evt);
 	if (err) {
 		pr_warn("global-timer: can't register interrupt %d (%d)\n",
diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c
index 670ff0f..6f174bb 100644
--- a/drivers/clocksource/exynos_mct.c
+++ b/drivers/clocksource/exynos_mct.c
@@ -524,7 +524,7 @@ static int __init exynos4_timer_resources(struct device_node *np, void __iomem *
 
 	if (mct_int_type == MCT_INT_PPI) {
 
-		err = request_percpu_irq(mct_irqs[MCT_L0_IRQ],
+		err = request_percpu_irq(mct_irqs[MCT_L0_IRQ], IRQF_TIMER,
 					 exynos4_mct_tick_isr, "MCT",
 					 &percpu_mct_tick);
 		WARN(err, "MCT: can't request IRQ %d (%d)\n",
diff --git a/drivers/clocksource/qcom-timer.c b/drivers/clocksource/qcom-timer.c
index ee358cd..80dc128 100644
--- a/drivers/clocksource/qcom-timer.c
+++ b/drivers/clocksource/qcom-timer.c
@@ -174,7 +174,7 @@ static int __init msm_timer_init(u32 dgt_hz, int sched_bits, int irq,
 	}
 
 	if (percpu)
-		res = request_percpu_irq(irq, msm_timer_interrupt,
+		res = request_percpu_irq(irq, IRQF_TIMER, msm_timer_interrupt,
 					 "gp_timer", msm_evt);
 
 	if (res) {
diff --git a/drivers/clocksource/time-armada-370-xp.c b/drivers/clocksource/time-armada-370-xp.c
index 4440aef..9643abd 100644
--- a/drivers/clocksource/time-armada-370-xp.c
+++ b/drivers/clocksource/time-armada-370-xp.c
@@ -309,7 +309,7 @@ static int __init armada_370_xp_timer_common_init(struct device_node *np)
 	/*
 	 * Setup clockevent timer (interrupt-driven).
 	 */
-	res = request_percpu_irq(armada_370_xp_clkevt_irq,
+	res = request_percpu_irq(armada_370_xp_clkevt_irq, IRQF_TIMER,
 				armada_370_xp_timer_interrupt,
 				"armada_370_xp_per_cpu_tick",
 				armada_370_xp_evt);
diff --git a/drivers/clocksource/timer-nps.c b/drivers/clocksource/timer-nps.c
index da1f798..dbdb622 100644
--- a/drivers/clocksource/timer-nps.c
+++ b/drivers/clocksource/timer-nps.c
@@ -256,7 +256,7 @@ static int __init nps_setup_clockevent(struct device_node *node)
 		return ret;
 
 	/* Needs apriori irq_set_percpu_devid() done in intc map function */
-	ret = request_percpu_irq(nps_timer0_irq, timer_irq_handler,
+	ret = request_percpu_irq(nps_timer0_irq, timer_irq_handler, IRQF_TIMER,
 				 "Timer0 (per-cpu-tick)",
 				 &nps_clockevent_device);
 	if (ret) {
diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index 61dd446..8004f670 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -3517,7 +3517,7 @@ static int mvneta_open(struct net_device *dev)
 		ret = request_irq(pp->dev->irq, mvneta_isr, 0,
 				  dev->name, pp);
 	else
-		ret = request_percpu_irq(pp->dev->irq, mvneta_percpu_isr,
+		ret = request_percpu_irq(pp->dev->irq, 0, mvneta_percpu_isr,
 					 dev->name, pp->ports);
 	if (ret) {
 		netdev_err(pp->dev, "cannot request irq %d\n", pp->dev->irq);
diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 9612b84..0f5ab4a 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -661,7 +661,7 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
 
 	irq = platform_get_irq(pmu_device, 0);
 	if (irq > 0 && irq_is_percpu(irq)) {
-		err = request_percpu_irq(irq, handler, "arm-pmu",
+		err = request_percpu_irq(irq, 0, handler, "arm-pmu",
 					 &hw_events->percpu_pmu);
 		if (err) {
 			pr_err("unable to request IRQ%d for ARM PMU counters\n",
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 53144e7..bc3b675 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -152,8 +152,9 @@ struct irqaction {
 			unsigned long flags, const char *name, void *dev_id);
 
 extern int __must_check
-request_percpu_irq(unsigned int irq, irq_handler_t handler,
-		   const char *devname, void __percpu *percpu_dev_id);
+request_percpu_irq(unsigned int irq, unsigned long flags,
+		   irq_handler_t handler,  const char *devname,
+		   void __percpu *percpu_dev_id);
 
 extern void free_irq(unsigned int, void *);
 extern void free_percpu_irq(unsigned int, void __percpu *);
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index a4afe5c..c0a23e2 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1951,6 +1951,7 @@ int setup_percpu_irq(unsigned int irq, struct irqaction *act)
 /**
  *	request_percpu_irq - allocate a percpu interrupt line
  *	@irq: Interrupt line to allocate
+ *	@flags: Interrupt type flags (IRQF_TIMER only)
  *	@handler: Function to be called when the IRQ occurs.
  *	@devname: An ascii name for the claiming device
  *	@dev_id: A percpu cookie passed back to the handler function
@@ -1964,8 +1965,9 @@ int setup_percpu_irq(unsigned int irq, struct irqaction *act)
  *	the handler gets called with the interrupted CPU's instance of
  *	that variable.
  */
-int request_percpu_irq(unsigned int irq, irq_handler_t handler,
-		       const char *devname, void __percpu *dev_id)
+int request_percpu_irq(unsigned int irq, unsigned long flags,
+		       irq_handler_t handler, const char *devname,
+		       void __percpu *dev_id)
 {
 	struct irqaction *action;
 	struct irq_desc *desc;
@@ -1979,12 +1981,15 @@ int request_percpu_irq(unsigned int irq, irq_handler_t handler,
 	    !irq_settings_is_per_cpu_devid(desc))
 		return -EINVAL;
 
+	if (flags && flags != IRQF_TIMER)
+		return -EINVAL;
+
 	action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
 	if (!action)
 		return -ENOMEM;
 
 	action->handler = handler;
-	action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND;
+	action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
 	action->name = devname;
 	action->percpu_dev_id = dev_id;
 
diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
index 35d7100..54809c8 100644
--- a/virt/kvm/arm/arch_timer.c
+++ b/virt/kvm/arm/arch_timer.c
@@ -523,8 +523,9 @@ int kvm_timer_hyp_init(void)
 		host_vtimer_irq_flags = IRQF_TRIGGER_LOW;
 	}
 
-	err = request_percpu_irq(host_vtimer_irq, kvm_arch_timer_handler,
-				 "kvm guest timer", kvm_get_running_vcpus());
+	err = request_percpu_irq(host_vtimer_irq, IRQF_TIMER,
+				 kvm_arch_timer_handler, "kvm guest timer",
+				 kvm_get_running_vcpus());
 	if (err) {
 		kvm_err("kvm_arch_timer: can't request interrupt %d (%d)\n",
 			host_vtimer_irq, err);
diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
index 276139a..a34d315 100644
--- a/virt/kvm/arm/vgic/vgic-init.c
+++ b/virt/kvm/arm/vgic/vgic-init.c
@@ -430,7 +430,7 @@ int kvm_vgic_hyp_init(void)
 		return ret;
 
 	kvm_vgic_global_state.maint_irq = gic_kvm_info->maint_irq;
-	ret = request_percpu_irq(kvm_vgic_global_state.maint_irq,
+	ret = request_percpu_irq(kvm_vgic_global_state.maint_irq, 0,
 				 vgic_maintenance_handler,
 				 "vgic", kvm_get_running_vcpus());
 	if (ret) {
-- 
1.9.1

Re: [PATCH V8 1/3] irq: Add flags to request_percpu_irq function

[Vineet Gupta]

On 03/23/2017 10:42 AM, Daniel Lezcano wrote:
> In the next changes, we track the interrupts but we discard the timers as
> that does not make sense. The next interrupt on a timer is predictable.
>
> But, the API request_percpu_irq does not allow to pass a flag, hence specifying
> if the interrupt type is a timer.
>
> Solve this by passing a 'flags' parameter to the function and change all the
> callers to pass IRQF_TIMER when the interrupt is a timer interrupt, zero
> otherwise.
>
> For now, in order to prevent a misusage of this parameter, only the IRQF_TIMER
> flag is a valid parameter to be passed to the request_percpu_irq function.
>
> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Acked-by: Vineet Gupta <vgupta@synopsys.com>   # for arch/arc, arc_timer bits

Re: [PATCH V8 1/3] irq: Add flags to request_percpu_irq function

[Mark Rutland]

Hi Daniel,

On Thu, Mar 23, 2017 at 06:42:01PM +0100, Daniel Lezcano wrote:
> In the next changes, we track the interrupts but we discard the timers as
> that does not make sense. The next interrupt on a timer is predictable.

Sorry, but I could not parse this. 

[...]

> diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
> index 9612b84..0f5ab4a 100644
> --- a/drivers/perf/arm_pmu.c
> +++ b/drivers/perf/arm_pmu.c
> @@ -661,7 +661,7 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
>  
>  	irq = platform_get_irq(pmu_device, 0);
>  	if (irq > 0 && irq_is_percpu(irq)) {
> -		err = request_percpu_irq(irq, handler, "arm-pmu",
> +		err = request_percpu_irq(irq, 0, handler, "arm-pmu",
>  					 &hw_events->percpu_pmu);
>  		if (err) {
>  			pr_err("unable to request IRQ%d for ARM PMU counters\n",

Please Cc myself and Will Deacon when modifying the arm_pmu driver, as
per MAINTAINERS. I only spotted this patch by chance.

This conflicts with arm_pmu changes I have queued for v4.12 [1].

So, can we leave the prototype of request_percpu_irq() as-is?

Why not add a new request_percpu_irq_flags() function, and leave
request_percpu_irq() as a wrapper for that? e.g.

static inline int
request_percpu_irq(unsigned int irq, irq_handler_t handler,
		   const char *devname, void __percpu *percpu_dev_id)
{
	return request_percpu_irq_flags(irq, handler, devname,
					percpu_dev_id, 0);
}

... that would avoid having to touch any non-timer driver for now.

[...]

> -request_percpu_irq(unsigned int irq, irq_handler_t handler,
> -		   const char *devname, void __percpu *percpu_dev_id);
> +request_percpu_irq(unsigned int irq, unsigned long flags,
> +		   irq_handler_t handler,  const char *devname,
> +		   void __percpu *percpu_dev_id);
>  

Looking at request_irq, the prototype is:

int __must_check
request_irq(unsigned int irq, irq_handler_t handler,
	    unsigned long flags, const char *name,
	    void *dev);

... surely it would be better to share the same argument order? i.e.

int __must_check
request_percpu_irq(unsigned int irq, irq_handler_t handler,
		   unsigned long flags, const char *devname,
		   void __percpu *percpu_dev_id);

Thanks,
Mark.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git/log/?h=arm/perf/refactoring

Re: [PATCH V8 1/3] irq: Add flags to request_percpu_irq function

[Daniel Lezcano]

Hi Mark,

On Thu, Mar 23, 2017 at 06:54:52PM +0000, Mark Rutland wrote:
> Hi Daniel,
> 
> On Thu, Mar 23, 2017 at 06:42:01PM +0100, Daniel Lezcano wrote:
> > In the next changes, we track the interrupts but we discard the timers as
> > that does not make sense. The next interrupt on a timer is predictable.
> 
> Sorry, but I could not parse this. 

I meant we are measuring when are happening the interrupts by getting the local
clock in the interrupt handler. But if the interrupts are coming from a timer, it
is not necessary to do that because we already know when they will occur.

So, in order to sort out which interrupt we measure, we use the IRQF_TIMER flag.

Unfortunately, this flag is missing when we do a request_percpu_irq. The
purpose of this patch is to fix that.

> > diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
> > index 9612b84..0f5ab4a 100644
> > --- a/drivers/perf/arm_pmu.c
> > +++ b/drivers/perf/arm_pmu.c
> > @@ -661,7 +661,7 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
> >  
> >  	irq = platform_get_irq(pmu_device, 0);
> >  	if (irq > 0 && irq_is_percpu(irq)) {
> > -		err = request_percpu_irq(irq, handler, "arm-pmu",
> > +		err = request_percpu_irq(irq, 0, handler, "arm-pmu",
> >  					 &hw_events->percpu_pmu);
> >  		if (err) {
> >  			pr_err("unable to request IRQ%d for ARM PMU counters\n",
> 
> Please Cc myself and Will Deacon when modifying the arm_pmu driver, as
> per MAINTAINERS. I only spotted this patch by chance.

Ah, ok, sorry for that. Thanks for spotting this, you should have been Cc'ed by
my cccmd script. I will check that.

> This conflicts with arm_pmu changes I have queued for v4.12 [1].
> 
> So, can we leave the prototype of request_percpu_irq() as-is?
> 
> Why not add a new request_percpu_irq_flags() function, and leave
> request_percpu_irq() as a wrapper for that? e.g.

[ ... ]

> static inline int
> request_percpu_irq(unsigned int irq, irq_handler_t handler,
> 		   const char *devname, void __percpu *percpu_dev_id)
> {
> 	return request_percpu_irq_flags(irq, handler, devname,
> 					percpu_dev_id, 0);
> }
> 
> ... that would avoid having to touch any non-timer driver for now.

Mmh, yes. That's a good suggestion.

> [...]
> 
> > -request_percpu_irq(unsigned int irq, irq_handler_t handler,
> > -		   const char *devname, void __percpu *percpu_dev_id);
> > +request_percpu_irq(unsigned int irq, unsigned long flags,
> > +		   irq_handler_t handler,  const char *devname,
> > +		   void __percpu *percpu_dev_id);
> >  
> 
> Looking at request_irq, the prototype is:
> 
> int __must_check
> request_irq(unsigned int irq, irq_handler_t handler,
> 	    unsigned long flags, const char *name,
> 	    void *dev);
> 
> ... surely it would be better to share the same argument order? i.e.
> 
> int __must_check
> request_percpu_irq(unsigned int irq, irq_handler_t handler,
> 		   unsigned long flags, const char *devname,
> 		   void __percpu *percpu_dev_id);
> 

Agree.

Thanks for the review.

  -- Daniel


-- 

 <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

Re: [PATCH V8 1/3] irq: Add flags to request_percpu_irq function

[Andrew Jones]

On Thu, Mar 23, 2017 at 06:42:01PM +0100, Daniel Lezcano wrote:
> diff --git a/drivers/clocksource/timer-nps.c b/drivers/clocksource/timer-nps.c
> index da1f798..dbdb622 100644
> --- a/drivers/clocksource/timer-nps.c
> +++ b/drivers/clocksource/timer-nps.c
> @@ -256,7 +256,7 @@ static int __init nps_setup_clockevent(struct device_node *node)
>  		return ret;
>  
>  	/* Needs apriori irq_set_percpu_devid() done in intc map function */
> -	ret = request_percpu_irq(nps_timer0_irq, timer_irq_handler,
> +	ret = request_percpu_irq(nps_timer0_irq, timer_irq_handler, IRQF_TIMER,
>  				 "Timer0 (per-cpu-tick)",
>  				 &nps_clockevent_device);

Wrong parameter order here.

drew