1 files changed, 84 insertions, 0 deletions
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
new file mode 100644
index 00000000..e747ecd4
--- /dev/null
+++ b/include/linux/dynamic_debug.h
@@ -0,0 +1,84 @@
+#ifndef _DYNAMIC_DEBUG_H
+#define _DYNAMIC_DEBUG_H
+
+/* dynamic_printk_enabled, and dynamic_printk_enabled2 are bitmasks in which
+ * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They
+ * use independent hash functions, to reduce the chance of false positives.
+ */
+extern long long dynamic_debug_enabled;
+extern long long dynamic_debug_enabled2;
+
+/*
+ * 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:24;
+	/*
+ 	 * 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_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)
+#define _DPRINTK_FLAGS_DEFAULT 0
+	unsigned int flags:8;
+	char enabled;
+} __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 int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
+	__attribute__ ((format (printf, 2, 3)));
+
+#define dynamic_pr_debug(fmt, ...) do {					\
+	static struct _ddebug descriptor				\
+	__used								\
+	__attribute__((section("__verbose"), aligned(8))) =		\
+	{ KBUILD_MODNAME, __func__, __FILE__, fmt, __LINE__,		\
+		_DPRINTK_FLAGS_DEFAULT };				\
+	if (unlikely(descriptor.enabled))				\
+		__dynamic_pr_debug(&descriptor, pr_fmt(fmt), ##__VA_ARGS__); \
+	} while (0)
+
+
+#define dynamic_dev_dbg(dev, fmt, ...) do {				\
+	static struct _ddebug descriptor				\
+	__used								\
+	__attribute__((section("__verbose"), aligned(8))) =		\
+	{ KBUILD_MODNAME, __func__, __FILE__, fmt, __LINE__,		\
+		_DPRINTK_FLAGS_DEFAULT };				\
+	if (unlikely(descriptor.enabled))				\
+		dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__);	\
+	} while (0)
+
+#else
+
+static inline int ddebug_remove_module(const char *mod)
+{
+	return 0;
+}
+
+#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