[PATCH v2 3/4] tracing/remotes: Add REMOTE_EVENT_CUSTOM_PRINTK() helper

[Vincent Donnefort <vdonnefort@google.com>]

The current REMOTE_EVENT() takes as a __printk argument a string format
and a list of arguments, such as RE_STRUCT("foo=%d bar=%d", foo, bar).
Add a REMOTE_EVENT_CUSTOM_PRINTK() where the __printk argument can be a
function. This intends to support the creation of a "printk" event for
the arm64 nVHE/pKVM hypervisor with a dynamic prototype and by extension
a dynamic print format.

Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>

diff --git a/include/trace/define_remote_events.h b/include/trace/define_remote_events.h
index 676e803dc144..4f4d58e37b84 100644
--- a/include/trace/define_remote_events.h
+++ b/include/trace/define_remote_events.h
@@ -35,17 +35,26 @@ do {											\
 
 #define RE_PRINTK(__args...) __args
 
-#define REMOTE_EVENT(__name, __id, __struct, __printk)					\
-	REMOTE_EVENT_FORMAT(__name, __struct);						\
+#define REMOTE_EVENT_PRINT_FUNC(__name, __printk)					\
 	static void remote_event_print_##__name(void *evt, struct trace_seq *seq)	\
 	{										\
 		struct remote_event_format_##__name __maybe_unused *__entry = evt;	\
 		trace_seq_puts(seq, #__name);						\
-		remote_printk(__printk);						\
+		__printk;								\
 	}
+
+#define REMOTE_EVENT(__name, __id, __struct, __printk)					\
+	REMOTE_EVENT_FORMAT(__name, __struct);						\
+	REMOTE_EVENT_PRINT_FUNC(__name, remote_printk(__printk))
+
+#define REMOTE_EVENT_CUSTOM_PRINTK(__name, __id, __struct, __printk)			\
+	REMOTE_EVENT_FORMAT(__name, __struct);						\
+	REMOTE_EVENT_PRINT_FUNC(__name, __printk)
+
 #include REMOTE_EVENT_INCLUDE(REMOTE_EVENT_INCLUDE_FILE)
 
 #undef REMOTE_EVENT
+#undef REMOTE_EVENT_CUSTOM_PRINTK
 #undef RE_PRINTK
 #undef re_field
 #define re_field(__type, __field)							\
@@ -70,4 +79,8 @@ do {											\
 		.print_fmt	= remote_event_print_fmt_##__name,			\
 		.print		= remote_event_print_##__name,				\
 	}
+
+#define REMOTE_EVENT_CUSTOM_PRINTK(__name, __id, __struct, __printk)			\
+	REMOTE_EVENT(__name, __id, RE_STRUCT(__struct), "Unknown")
+
 #include REMOTE_EVENT_INCLUDE(REMOTE_EVENT_INCLUDE_FILE)
-- 
2.55.0.795.g602f6c329a-goog