v4.19.13 snapshot.
diff --git a/include/linux/irq_sim.h b/include/linux/irq_sim.h
new file mode 100644
index 0000000..630a57e
--- /dev/null
+++ b/include/linux/irq_sim.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2017-2018 Bartosz Golaszewski <brgl@bgdev.pl>
+ */
+
+#ifndef _LINUX_IRQ_SIM_H
+#define _LINUX_IRQ_SIM_H
+
+#include <linux/irq_work.h>
+#include <linux/device.h>
+
+/*
+ * Provides a framework for allocating simulated interrupts which can be
+ * requested like normal irqs and enqueued from process context.
+ */
+
+struct irq_sim_work_ctx {
+ struct irq_work work;
+ int irq;
+};
+
+struct irq_sim_irq_ctx {
+ int irqnum;
+ bool enabled;
+};
+
+struct irq_sim {
+ struct irq_sim_work_ctx work_ctx;
+ int irq_base;
+ unsigned int irq_count;
+ struct irq_sim_irq_ctx *irqs;
+};
+
+int irq_sim_init(struct irq_sim *sim, unsigned int num_irqs);
+int devm_irq_sim_init(struct device *dev, struct irq_sim *sim,
+ unsigned int num_irqs);
+void irq_sim_fini(struct irq_sim *sim);
+void irq_sim_fire(struct irq_sim *sim, unsigned int offset);
+int irq_sim_irqnum(struct irq_sim *sim, unsigned int offset);
+
+#endif /* _LINUX_IRQ_SIM_H */