root/sys/dev/pci/drm/include/linux/irqreturn.h 
/* Public domain. */

#ifndef _LINUX_IRQRETURN_H
#define _LINUX_IRQRETURN_H

typedef int irqreturn_t;
enum irqreturn {
        IRQ_NONE = 0,
        IRQ_HANDLED = 1
};

#endif