#ifndef _DYNAMIC_DEBUG_H
  #define _DYNAMIC_DEBUG_H

  /*
   * An instance of this structure is created in a special
   * ELF section at every dynamic debug callsite.  At runtime,
   * the special section is treated as an array of these.
   */
  struct _ddebug {
  	/*
  	 * These fields are used to drive the user interface
  	 * for selecting and displaying debug callsites.
  	 */
  	const char *modname;
  	const char *function;
  	const char *filename;
  	const char *format;

  	unsigned int lineno:18;

  	/*

  	 * The flags field controls the behaviour at the callsite.
  	 * The bits here are changed dynamically when the user

  	 * writes commands to <debugfs>/dynamic_debug/control

  	 */

  #define _DPRINTK_FLAGS_NONE	0
  #define _DPRINTK_FLAGS_PRINT	(1<<0) /* printk() a message using the format */

  #define _DPRINTK_FLAGS_INCL_MODNAME	(1<<1)
  #define _DPRINTK_FLAGS_INCL_FUNCNAME	(1<<2)
  #define _DPRINTK_FLAGS_INCL_LINENO	(1<<3)
  #define _DPRINTK_FLAGS_INCL_TID		(1<<4)

  #if defined DEBUG
  #define _DPRINTK_FLAGS_DEFAULT _DPRINTK_FLAGS_PRINT
  #else

  #define _DPRINTK_FLAGS_DEFAULT 0

  #endif

  	unsigned int flags:8;
  } __attribute__((aligned(8)));
  
  
  int ddebug_add_module(struct _ddebug *tab, unsigned int n,
  				const char *modname);
  
  #if defined(CONFIG_DYNAMIC_DEBUG)

  extern int ddebug_remove_module(const char *mod_name);

  extern __printf(2, 3)

  void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);

  extern int ddebug_dyndbg_module_param_cb(char *param, char *val,
  					const char *modname);

  struct device;

  extern __printf(3, 4)

  void __dynamic_dev_dbg(struct _ddebug *descriptor, const struct device *dev,
  		       const char *fmt, ...);

  struct net_device;

  extern __printf(3, 4)

  void __dynamic_netdev_dbg(struct _ddebug *descriptor,
  			  const struct net_device *dev,
  			  const char *fmt, ...);

  #define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt)		\

  	static struct _ddebug  __aligned(8)			\

  	__attribute__((section("__verbose"))) name = {		\
  		.modname = KBUILD_MODNAME,			\
  		.function = __func__,				\
  		.filename = __FILE__,				\
  		.format = (fmt),				\
  		.lineno = __LINE__,				\
  		.flags =  _DPRINTK_FLAGS_DEFAULT,		\

  	}
  
  #define dynamic_pr_debug(fmt, ...)				\
  do {								\
  	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);		\

  	if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))	\

  		__dynamic_pr_debug(&descriptor, pr_fmt(fmt),	\
  				   ##__VA_ARGS__);		\
  } while (0)
  
  #define dynamic_dev_dbg(dev, fmt, ...)				\
  do {								\

  	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);		\
  	if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))	\

  		__dynamic_dev_dbg(&descriptor, dev, fmt,	\
  				  ##__VA_ARGS__);		\
  } while (0)
  
  #define dynamic_netdev_dbg(dev, fmt, ...)			\
  do {								\
  	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);		\

  	if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))	\

  		__dynamic_netdev_dbg(&descriptor, dev, fmt,	\
  				     ##__VA_ARGS__);		\
  } while (0)

  #define dynamic_hex_dump(prefix_str, prefix_type, rowsize,	\
  			 groupsize, buf, len, ascii)		\
  do {								\
  	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor,		\
  		__builtin_constant_p(prefix_str) ? prefix_str : "hexdump");\
  	if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))	\
  		print_hex_dump(KERN_DEBUG, prefix_str,		\
  			       prefix_type, rowsize, groupsize,	\
  			       buf, len, ascii);		\
  } while (0)

  #else

  #include <linux/string.h>
  #include <linux/errno.h>

  static inline int ddebug_remove_module(const char *mod)

  {
  	return 0;
  }

  static inline int ddebug_dyndbg_module_param_cb(char *param, char *val,
  						const char *modname)
  {
  	if (strstr(param, "dyndbg")) {

  		/* avoid pr_warn(), which wants pr_fmt() fully defined */
  		printk(KERN_WARNING "dyndbg param is supported only in "

  			"CONFIG_DYNAMIC_DEBUG builds
  ");
  		return 0; /* allow and ignore */
  	}
  	return -EINVAL;
  }

  #define dynamic_pr_debug(fmt, ...)					\
  	do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)

  #define dynamic_dev_dbg(dev, fmt, ...)					\

  	do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0)

  #endif
  
  #endif