Merge tag 'irq-core-2024-05-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull interrupt subsystem updates from Thomas Gleixner:
 "Core code:

   - Interrupt storm detection for the lockup watchdog:

     Lockups which are caused by interrupt storms are not easy to debug
     because there is no information about the events which make the
     lockup detector trigger.

     To make this more user friendly, provide an extenstion to interrupt
     statistics which allows to take snapshots and an interface to
     retrieve the delta to the snapshot. Use this new mechanism in the
     watchdog code to do a two stage lockup analysis by taking the
     snapshot and printing the deltas for the topmost active interrupts
     on the second trigger.

     Note: This contains both the interrupt and the watchdog changes as
     the latter depend on the former obviously.

   - Avoid summation loops in the /proc/interrupts output and use the
     global counter when possible

   - Skip suspended interrupts on CPU hotplug operations to ensure that
     they are not delivered before the system resumes the device drivers
     when coming out of suspend.

   - On CPU hot-unplug interrupts which are affine to the outgoing CPU
     are migrated to a different CPU in the affinity mask. This can fail
     when the CPUs have no vectors left. Instead of giving up try to
     migrate it to any online CPU and thereby breaking the affinity
     setting in order to prevent a stale device interrupt which targets
     an offline CPU

   - The usual small cleanups

  Driver code:

   - Support for the RISCV AIA MSI controller

   - Make the interrupt allocation for the Loongson PCH controller more
     flexible to prevent vector exhaustion

   - The usual set of cleanups and fixes all over the place"

* tag 'irq-core-2024-05-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (51 commits)
  irqchip/gic-v3-its: Remove BUG_ON in its_vpe_irq_domain_alloc
  cpuidle: Avoid explicit cpumask allocation on stack
  irqchip/sifive-plic: Avoid explicit cpumask allocation on stack
  irqchip/riscv-aplic-direct: Avoid explicit cpumask allocation on stack
  irqchip/loongson-eiointc: Avoid explicit cpumask allocation on stack
  irqchip/gic-v3-its: Avoid explicit cpumask allocation on stack
  irqchip/irq-bcm6345-l1: Avoid explicit cpumask allocation on stack
  cpumask: Introduce cpumask_first_and_and()
  irqchip/irq-brcmstb-l2: Avoid saving mask on shutdown
  genirq: Reuse irq_is_nmi()
  genirq/cpuhotplug: Retry with cpu_online_mask when migration fails
  genirq/cpuhotplug: Skip suspended interrupts when restoring affinity
  arm64: dts: st: Add interrupt parent to pinctrl on stm32mp251
  arm64: dts: st: Add exti1 and exti2 nodes on stm32mp251
  ARM: dts: stm32: List exti parent interrupts on stm32mp131
  ARM: dts: stm32: List exti parent interrupts on stm32mp151
  arm64: Kconfig.platforms: Enable STM32_EXTI for ARCH_STM32
  irqchip/stm32-exti: Mark events reserved with RIF configuration check
  irqchip/stm32-exti: Skip secure events
  irqchip/stm32-exti: Convert driver to standard PM
  ...

1 files changed, 42 insertions, 23 deletions

diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index 4c6b32318ce3..88ac3652fcf2 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -134,7 +134,7 @@ static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
 	desc->name = NULL;
 	desc->owner = owner;
 	for_each_possible_cpu(cpu)
-		*per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
+		*per_cpu_ptr(desc->kstat_irqs, cpu) = (struct irqstat) { };
 	desc_smp_init(desc, node, affinity);
 }
 
@@ -186,7 +186,7 @@ static int init_desc(struct irq_desc *desc, int irq, int node,
 		     const struct cpumask *affinity,
 		     struct module *owner)
 {
-	desc->kstat_irqs = alloc_percpu(unsigned int);
+	desc->kstat_irqs = alloc_percpu(struct irqstat);
 	if (!desc->kstat_irqs)
 		return -ENOMEM;
 
@@ -911,10 +911,7 @@ int irq_set_percpu_devid_partition(unsigned int irq,
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 
-	if (!desc)
-		return -EINVAL;
-
-	if (desc->percpu_enabled)
+	if (!desc || desc->percpu_enabled)
 		return -EINVAL;
 
 	desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
@@ -922,10 +919,7 @@ int irq_set_percpu_devid_partition(unsigned int irq,
 	if (!desc->percpu_enabled)
 		return -ENOMEM;
 
-	if (affinity)
-		desc->percpu_affinity = affinity;
-	else
-		desc->percpu_affinity = cpu_possible_mask;
+	desc->percpu_affinity = affinity ? : cpu_possible_mask;
 
 	irq_set_percpu_devid_flags(irq);
 	return 0;
@@ -968,33 +962,58 @@ unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 
-	return desc && desc->kstat_irqs ?
-			*per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
+	return desc && desc->kstat_irqs ? per_cpu(desc->kstat_irqs->cnt, cpu) : 0;
 }
 
-static bool irq_is_nmi(struct irq_desc *desc)
+unsigned int kstat_irqs_desc(struct irq_desc *desc, const struct cpumask *cpumask)
 {
-	return desc->istate & IRQS_NMI;
-}
-
-static unsigned int kstat_irqs(unsigned int irq)
-{
-	struct irq_desc *desc = irq_to_desc(irq);
 	unsigned int sum = 0;
 	int cpu;
 
-	if (!desc || !desc->kstat_irqs)
-		return 0;
 	if (!irq_settings_is_per_cpu_devid(desc) &&
 	    !irq_settings_is_per_cpu(desc) &&
 	    !irq_is_nmi(desc))
 		return data_race(desc->tot_count);
 
-	for_each_possible_cpu(cpu)
-		sum += data_race(*per_cpu_ptr(desc->kstat_irqs, cpu));
+	for_each_cpu(cpu, cpumask)
+		sum += data_race(per_cpu(desc->kstat_irqs->cnt, cpu));
 	return sum;
 }
 
+static unsigned int kstat_irqs(unsigned int irq)
+{
+	struct irq_desc *desc = irq_to_desc(irq);
+
+	if (!desc || !desc->kstat_irqs)
+		return 0;
+	return kstat_irqs_desc(desc, cpu_possible_mask);
+}
+
+#ifdef CONFIG_GENERIC_IRQ_STAT_SNAPSHOT
+
+void kstat_snapshot_irqs(void)
+{
+	struct irq_desc *desc;
+	unsigned int irq;
+
+	for_each_irq_desc(irq, desc) {
+		if (!desc->kstat_irqs)
+			continue;
+		this_cpu_write(desc->kstat_irqs->ref, this_cpu_read(desc->kstat_irqs->cnt));
+	}
+}
+
+unsigned int kstat_get_irq_since_snapshot(unsigned int irq)
+{
+	struct irq_desc *desc = irq_to_desc(irq);
+
+	if (!desc || !desc->kstat_irqs)
+		return 0;
+	return this_cpu_read(desc->kstat_irqs->cnt) - this_cpu_read(desc->kstat_irqs->ref);
+}
+
+#endif
+
 /**
  * kstat_irqs_usr - Get the statistics for an interrupt from thread context
  * @irq:	The interrupt number