v4.19.13 snapshot.
diff --git a/kernel/irq/debug.h b/kernel/irq/debug.h
new file mode 100644
index 0000000..8ccb326
--- /dev/null
+++ b/kernel/irq/debug.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Debugging printout:
+ */
+
+#define ___P(f) if (desc->status_use_accessors & f) printk("%14s set\n", #f)
+#define ___PS(f) if (desc->istate & f) printk("%14s set\n", #f)
+/* FIXME */
+#define ___PD(f) do { } while (0)
+
+static inline void print_irq_desc(unsigned int irq, struct irq_desc *desc)
+{
+ static DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 5);
+
+ if (!__ratelimit(&ratelimit))
+ return;
+
+ printk("irq %d, desc: %p, depth: %d, count: %d, unhandled: %d\n",
+ irq, desc, desc->depth, desc->irq_count, desc->irqs_unhandled);
+ printk("->handle_irq(): %p, %pS\n",
+ desc->handle_irq, desc->handle_irq);
+ printk("->irq_data.chip(): %p, %pS\n",
+ desc->irq_data.chip, desc->irq_data.chip);
+ printk("->action(): %p\n", desc->action);
+ if (desc->action) {
+ printk("->action->handler(): %p, %pS\n",
+ desc->action->handler, desc->action->handler);
+ }
+
+ ___P(IRQ_LEVEL);
+ ___P(IRQ_PER_CPU);
+ ___P(IRQ_NOPROBE);
+ ___P(IRQ_NOREQUEST);
+ ___P(IRQ_NOTHREAD);
+ ___P(IRQ_NOAUTOEN);
+
+ ___PS(IRQS_AUTODETECT);
+ ___PS(IRQS_REPLAY);
+ ___PS(IRQS_WAITING);
+ ___PS(IRQS_PENDING);
+
+ ___PD(IRQS_INPROGRESS);
+ ___PD(IRQS_DISABLED);
+ ___PD(IRQS_MASKED);
+}
+
+#undef ___P
+#undef ___PS
+#undef ___PD