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@kernel.org>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Dmitry Ilvokhin <d@ilvokhin.com>
Link: https://patch.msgid.link/20260517194932.005787611@kernel.org

diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index bacbf4020242fa71b7a2a65f48300c30410fa689..37eec0337867c06d1eeefb9942eb3aca2aeb0cef 100644 (file)
--- 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 23f21763bfed7738e13f20aed58ec9132899d7d7..80ef4e27dcf470a6bcaa9568722f8d0f3a8b5c41 100644 (file)
--- 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,