[PATCH V10 1/3] irq: Allow to pass the IRQF_TIMER flag with percpu irq request

On Tue, May 16, 2017 at 09:44:32PM +0200, Daniel Lezcano wrote:

In the next changes, we track when the interrupts occur in order to
statistically compute when is supposed to happen the next interrupt.

In all the interruptions, it does not make sense to store the timer interrupt
occurences and try to predict the next interrupt as when know the expiration
time.

The request_irq() has a irq flags parameter and the timer drivers use it to
pass the IRQF_TIMER flag, letting us know the interrupt is coming from a timer.
Based on this flag, we can discard these interrupts when tracking them.

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

Add a function request_percpu_irq_flags() where we can specify the flags. The
request_percpu_irq() function is changed to be a wrapper to
request_percpu_irq_flags() passing a zero flag parameter.

Change the timers using request_percpu_irq() to use request_percpu_irq_flags()
instead with the IRQF_TIMER flag set.

For now, in order to prevent a misusage of this parameter, only the IRQF_TIMER
flag (or zero) is a valid parameter to be passed to the
request_percpu_irq_flags() function.

Signed-off-by: Daniel Lezcano <redacted>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Vineet Gupta <redacted>
Cc: Marc Zyngier <redacted>
Cc: Patrice Chotard <redacted>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Javier Martinez Canillas <redacted>
Cc: Christoffer Dall <redacted>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Kr?m?? <redacted>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
---
Changelog:

   V10:
	- Drop the change for arch arm virtual timer
	  https://lkml.org/lkml/2017/4/25/184
   V9:
	- Clarified the patch description
	- Fixed EXPORT_SYMBOL_GPL(request_percpu_irq_flags)
---
 arch/arm/kernel/smp_twd.c                |  3 ++-
 drivers/clocksource/arc_timer.c          |  4 ++--
 drivers/clocksource/arm_arch_timer.c     | 20 ++++++++++++--------
 drivers/clocksource/arm_global_timer.c   |  4 ++--
 drivers/clocksource/exynos_mct.c         |  7 ++++---
 drivers/clocksource/qcom-timer.c         |  4 ++--
 drivers/clocksource/time-armada-370-xp.c |  9 +++++----
 drivers/clocksource/timer-nps.c          |  6 +++---
 include/linux/interrupt.h                | 11 ++++++++++-
 kernel/irq/manage.c                      | 15 ++++++++++-----
 10 files changed, 52 insertions(+), 31 deletions(-)

As an aside, perhaps it would make more sense to move the
request_percpu_irq_flags() addition into a preparatory patch? That way
it's clearly separated from the mechanical clocksource changes, and it's
easy to see how it works.

Either way, for arm_arch_timer:

Acked-by: Mark Rutland <mark.rutland@arm.com>

Thanks,
Mark.