#ifndef OP_IMPL_H
#define OP_IMPL_H 1
+struct pt_regs;
+
+extern int null_perf_irq(struct pt_regs *regs);
+extern int (*perf_irq)(struct pt_regs *regs);
+
/* Per-counter configuration as set via oprofilefs. */
struct op_counter_config {
unsigned long enabled;