dynamic_debug: dynamic hex dump

Introduce print_hex_dump_debug() that can be dynamically controlled, similar to
pr_debug.

Also, make print_hex_dump_bytes() dynamically controlled

Implement only 'p' flag (_DPRINTK_FLAGS_PRINT) to keep it simple since hex dump prints
multiple lines and long prefix would impact readability.
To provide line/file etc. information, use pr_debug or similar
before/after print_hex_dump_debug()

Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 6dd4787..2fe93b2 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -95,6 +95,17 @@
 				     ##__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>