1 files changed, 41 insertions, 0 deletions
diff --git a/include/linux/irqchip/chained_irq.h b/include/linux/irqchip/chained_irq.h
new file mode 100644
index 000000000..dd8b3c476
--- /dev/null
+++ b/include/linux/irqchip/chained_irq.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Chained IRQ handlers support.
+ *
+ * Copyright (C) 2011 ARM Ltd.
+ */
+#ifndef __IRQCHIP_CHAINED_IRQ_H
+#define __IRQCHIP_CHAINED_IRQ_H
+
+#include <linux/irq.h>
+
+/*
+ * Entry/exit functions for chained handlers where the primary IRQ chip
+ * may implement either fasteoi or level-trigger flow control.
+ */
+static inline void chained_irq_enter(struct irq_chip *chip,
+				     struct irq_desc *desc)
+{
+	/* FastEOI controllers require no action on entry. */
+	if (chip->irq_eoi)
+		return;
+
+	if (chip->irq_mask_ack) {
+		chip->irq_mask_ack(&desc->irq_data);
+	} else {
+		chip->irq_mask(&desc->irq_data);
+		if (chip->irq_ack)
+			chip->irq_ack(&desc->irq_data);
+	}
+}
+
+static inline void chained_irq_exit(struct irq_chip *chip,
+				    struct irq_desc *desc)
+{
+	if (chip->irq_eoi)
+		chip->irq_eoi(&desc->irq_data);
+	else
+		chip->irq_unmask(&desc->irq_data);
+}
+
+#endif /* __IRQCHIP_CHAINED_IRQ_H */