#ifndef _LINUX_TRACE_BOOT_H#define _LINUX_TRACE_BOOT_H #include <linux/module.h>#include <linux/kallsyms.h>#include <linux/init.h> /* * Structure which defines the trace of an initcall * while it is called. * You don't have to fill the func field since it is * only used internally by the tracer. */struct boot_trace_call {	pid_t			caller;	char			func[KSYM_SYMBOL_LEN];}; /* * Structure which defines the trace of an initcall * while it returns. */struct boot_trace_ret {	char			func[KSYM_SYMBOL_LEN];	int				result;	unsigned long long	duration;		/* nsecs */}; #ifdef CONFIG_BOOT_TRACER/* Append the traces on the ring-buffer */extern void trace_boot_call(struct boot_trace_call *bt, initcall_t fn);extern void trace_boot_ret(struct boot_trace_ret *bt, initcall_t fn); /* Tells the tracer that smp_pre_initcall is finished. * So we can start the tracing */extern void start_boot_trace(void); /* Resume the tracing of other necessary events * such as sched switches */extern void enable_boot_trace(void); /* Suspend this tracing. Actually, only sched_switches tracing have * to be suspended. Initcalls doesn't need it.) */extern void disable_boot_trace(void);#elsestatic inlinevoid trace_boot_call(struct boot_trace_call *bt, initcall_t fn) { } static inlinevoid trace_boot_ret(struct boot_trace_ret *bt, initcall_t fn) { } static inline void start_boot_trace(void) { }static inline void enable_boot_trace(void) { }static inline void disable_boot_trace(void) { }#endif /* CONFIG_BOOT_TRACER */ #endif /* __LINUX_TRACE_BOOT_H */