[tip: irq/core] genirq: Update request_percpu_nmi() to take an affinity

tip-bot2 for Marc Zyngier
2025-10-27T16:31:08Z

The following commit has been merged into the irq/core branch of tip:

Commit-ID: b9c6aa9efc71dae656f9f913d1250ea08cd6e10f
Gitweb: https://git.kernel.org/tip/b9c6aa9efc71dae656f9f913d1250ea08cd6e10f
Author: Marc Zyngier <maz@kernel.org>
AuthorDate: Mon, 20 Oct 2025 13:29:32 +01:00
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 27 Oct 2025 17:16:35 +01:00

genirq: Update request_percpu_nmi() to take an affinity

Continue spreading the notion of affinity to the per CPU interrupt request
code by updating the call sites that use request_percpu_nmi() (all two of
them) to take an affinity pointer. This pointer is firmly NULL for now.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20251020122944.3074811-16-maz@kernel.org
---
arch/arm64/kernel/smp.c | 2 +-
drivers/perf/arm_pmu.c | 2 +-
include/linux/interrupt.h | 4 ++--
kernel/irq/manage.c | 12 +++++++-----
4 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 68cea3a..6fb838e 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -1094,7 +1094,7 @@ static void ipi_setup_sgi(int ipi)
irq = ipi_irq_base + ipi;

if (ipi_should_be_nmi(ipi)) {
- err = request_percpu_nmi(irq, ipi_handler, "IPI", &irq_stat);
+ err = request_percpu_nmi(irq, ipi_handler, "IPI", NULL, &irq_stat);
WARN(err, "Could not request IRQ %d as NMI, err=%d\n", irq, err);
} else {
err = request_percpu_irq(irq, ipi_handler, "IPI", &irq_stat);
diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 5c310e8..22c601b 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -659,7 +659,7 @@ int armpmu_request_irq(int irq, int cpu)
irq_ops = &pmunmi_ops;
}
} else if (armpmu_count_irq_users(irq) == 0) {
- err = request_percpu_nmi(irq, handler, "arm-pmu", &cpu_armpmu);
+ err = request_percpu_nmi(irq, handler, "arm-pmu", NULL, &cpu_armpmu);

/* If cannot get an NMI, get a normal interrupt */
if (err) {
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 52147d5..81506ab 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -197,8 +197,8 @@ request_percpu_irq(unsigned int irq, irq_handler_t handler,
}

extern int __must_check
-request_percpu_nmi(unsigned int irq, irq_handler_t handler,
- const char *devname, void __percpu *dev);
+request_percpu_nmi(unsigned int irq, irq_handler_t handler, const char *name,
+ const struct cpumask *affinity, void __percpu *dev_id);

extern const 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 5f4c651..b1a3140 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -2527,6 +2527,7 @@ EXPORT_SYMBOL_GPL(__request_percpu_irq);
* @irq: Interrupt line to allocate
* @handler: Function to be called when the IRQ occurs.
* @name: An ascii name for the claiming device
+ * @affinity: A cpumask describing the target CPUs for this interrupt
* @dev_id: A percpu cookie passed back to the handler function
*
* This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs
@@ -2543,8 +2544,8 @@ EXPORT_SYMBOL_GPL(__request_percpu_irq);
* If the interrupt line cannot be used to deliver NMIs, function
* will fail returning a negative value.
*/
-int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
- const char *name, void __percpu *dev_id)
+int request_percpu_nmi(unsigned int irq, irq_handler_t handler, const char *name,
+ const struct cpumask *affinity, void __percpu *dev_id)
{
struct irqaction *action;
struct irq_desc *desc;
@@ -2561,12 +2562,13 @@ int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
!irq_supports_nmi(desc))
return -EINVAL;

- /* The line cannot already be NMI */
- if (irq_is_nmi(desc))
+ /* The line cannot be NMI already if the new request covers all CPUs */
+ if (irq_is_nmi(desc) &&
+ (!affinity || cpumask_equal(affinity, cpu_possible_mask)))
return -EINVAL;

action = create_percpu_irqaction(handler, IRQF_NO_THREAD | IRQF_NOBALANCING,
- name, NULL, dev_id);
+ name, affinity, dev_id);
if (!action)
return -ENOMEM;