[PATCH v2] irqchip/mips-gic: allow forced affinity

[PATCH v2] irqchip/mips-gic: allow forced affinity

[Markus Stockhausen]

Devices of the Realtek MIPS Otto platform use the official rtl-otto-timer
as clock event generator and cpu clocksource. It is registered for cpu
startup via cpuhp_setup_state() and forces the affinity of the clockevent
interrupts to the appropriate cpu via irq_force_affinity().

On the "smaller" devices with a vendor specific interrupt controller
(supported by irq-realtek-rtl) the registration works fine. The "larger"
RTL931x series is based on a MIPS interAptiv dual core with a MIPS GIC
controller. Interrupt routing setup is cancelled because gic_set_affinity()
does not accept the current (not yet online) cpu as a target.

Relax the checks by evaluating the force parameter that is provided for
exactly this purpose like in other drivers. With this patch affinity can
be set as follows:

- force = false: allow to set affinity to any online cpu
- force = true: allow to set affinity to any cpu

Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>
Signed-off-by: Sebastian Gottschall <s.gottschall@dd-wrt.com>
---
 drivers/irqchip/irq-mips-gic.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c
index bca8053864b2..1c2284297354 100644
--- a/drivers/irqchip/irq-mips-gic.c
+++ b/drivers/irqchip/irq-mips-gic.c
@@ -375,9 +375,13 @@ static int gic_set_affinity(struct irq_data *d, const struct cpumask *cpumask,
 	/*
 	 * The GIC specifies that we can only route an interrupt to one VP(E),
 	 * ie. CPU in Linux parlance, at a time. Therefore we always route to
-	 * the first online CPU in the mask.
+	 * the first forced or online CPU in the mask.
 	 */
-	cpu = cpumask_first_and(cpumask, cpu_online_mask);
+	if (force)
+		cpu = cpumask_first(cpumask);
+	else
+		cpu = cpumask_first_and(cpumask, cpu_online_mask);
+
 	if (cpu >= NR_CPUS)
 		return -EINVAL;
 
-- 
2.47.0

Re: [PATCH v2] irqchip/mips-gic: allow forced affinity

[Thomas Gleixner]

On Mon, May 26 2025 at 09:41, Markus Stockhausen wrote:
>
> Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>
> Signed-off-by: Sebastian Gottschall <s.gottschall@dd-wrt.com>

This Signed-off-by chain is broken.

https://www.kernel.org/doc/html/latest/process/submitting-patches.html#sign-your-work-the-developer-s-certificate-of-origin

and the following paragraphs explain it.

AW: [PATCH v2] irqchip/mips-gic: allow forced affinity

[markus.stockhausen]

> Von: Thomas Gleixner <tglx@linutronix.de> 
> Gesendet: Donnerstag, 12. Juni 2025 15:14
> 
> On Mon, May 26 2025 at 09:41, Markus Stockhausen wrote:
> >
> > Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>
> > Signed-off-by: Sebastian Gottschall <s.gottschall@dd-wrt.com>
>
> This Signed-off-by chain is broken.
>
>
https://www.kernel.org/doc/html/latest/process/submitting-patches.html#sign-
your-work-the-developer-s-certificate-of-origin
>
> and the following paragraphs explain it.

This is my first co-authorship. So want to make sure that I understand it
correctly.

- I developed the patched and
- Sebastian gave helpful input for it.

So it should be like this?

Co-developed-by: Sebastian Gottschall <s.gottschall@dd-wrt.com>
Signed-off-by: Sebastian Gottschall <s.gottschall@dd-wrt.com>
Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>

Thanks in advance.

Markus

Re: AW: [PATCH v2] irqchip/mips-gic: allow forced affinity

[Thomas Gleixner]

On Fri, Jun 13 2025 at 07:35, markus stockhausen wrote:
>> Von: Thomas Gleixner <tglx@linutronix.de> 
>> Gesendet: Donnerstag, 12. Juni 2025 15:14
>> 
>> On Mon, May 26 2025 at 09:41, Markus Stockhausen wrote:
>> >
>> > Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>
>> > Signed-off-by: Sebastian Gottschall <s.gottschall@dd-wrt.com>
>>
>> This Signed-off-by chain is broken.
>>
>>
> https://www.kernel.org/doc/html/latest/process/submitting-patches.html#sign-
> your-work-the-developer-s-certificate-of-origin
>>
>> and the following paragraphs explain it.
>
> This is my first co-authorship. So want to make sure that I understand it
> correctly.
>
> - I developed the patched and
> - Sebastian gave helpful input for it.
>
> So it should be like this?
>
> Co-developed-by: Sebastian Gottschall <s.gottschall@dd-wrt.com>
> Signed-off-by: Sebastian Gottschall <s.gottschall@dd-wrt.com>
> Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>

Yes.