[tip: irq/core] genirq: Expose irq_find_desc_at_or_after() in core code

[tip-bot2 for Thomas Gleixner]

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

Commit-ID:     7603e0575d8a92318bd4695917fce7ec2c5825a1
Gitweb:        https://git.kernel.org/tip/7603e0575d8a92318bd4695917fce7ec2c5825a1
Author:        Thomas Gleixner <tglx@xxxxxxxxxx>
AuthorDate:    Sun, 17 May 2026 22:02:39 +02:00
Committer:     Thomas Gleixner <tglx@xxxxxxxxxx>
CommitterDate: Tue, 26 May 2026 16:21:15 +02:00

genirq: Expose irq_find_desc_at_or_after() in core code

... in preparation for a smarter iterator for /proc/interrupts.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxx>
Tested-by: Michael Kelley <mhklinux@xxxxxxxxxxx>
Reviewed-by: Dmitry Ilvokhin <d@xxxxxxxxxxxx>
Link: https://patch.msgid.link/20260517194932.005787611@xxxxxxxxxx
---
 kernel/irq/internals.h |  2 ++
 kernel/irq/irqdesc.c   | 15 ++++++++-------
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index bacbf40..37eec03 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -155,6 +155,8 @@ void irq_proc_calc_prec(void);
 static inline void irq_proc_calc_prec(void) { }
 #endif
 
+struct irq_desc *irq_find_desc_at_or_after(unsigned int offset);
+
 extern bool irq_can_set_affinity_usr(unsigned int irq);
 
 extern int irq_do_set_affinity(struct irq_data *data,
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index 23f2176..80ef4e2 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -181,15 +181,12 @@ static int irq_find_free_area(unsigned int from, unsigned int cnt)
 	return mas.index;
 }
 
-static unsigned int irq_find_at_or_after(unsigned int offset)
+struct irq_desc *irq_find_desc_at_or_after(unsigned int offset)
 {
 	unsigned long index = offset;
-	struct irq_desc *desc;
-
-	guard(rcu)();
-	desc = mt_find(&sparse_irqs, &index, total_nr_irqs);
 
-	return desc ? irq_desc_get_irq(desc) : total_nr_irqs;
+	lockdep_assert_in_rcu_read_lock();
+	return mt_find(&sparse_irqs, &index, total_nr_irqs);
 }
 
 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
@@ -934,7 +931,11 @@ EXPORT_SYMBOL_GPL(__irq_alloc_descs);
  */
 unsigned int irq_get_next_irq(unsigned int offset)
 {
-	return irq_find_at_or_after(offset);
+	struct irq_desc *desc;
+
+	guard(rcu)();
+	desc = irq_find_desc_at_or_after(offset);
+	return desc ? irq_desc_get_irq(desc) : total_nr_irqs;
 }
 
 struct irq_desc *__irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,