bug: Allow architectures to provide __WARN_printf()

In addition to providing __WARN_FLAGS(), allow an architecture to also
provide __WARN_printf().

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251110115757.807154591@infradead.org

Author: Peter Zijlstra

include/asm-generic/bug.h

@@ -100,23 +100,9 @@ void warn_slowpath_fmt(const char *file, const int line, unsigned taint,
 		       const char *fmt, ...);
 extern __printf(1, 2) void __warn_printk(const char *fmt, ...);
 
-#ifndef __WARN_FLAGS
-#define __WARN()		__WARN_printf(TAINT_WARN, NULL)
-#define __WARN_printf(taint, arg...) do {				\
-		instrumentation_begin();				\
-		warn_slowpath_fmt(__FILE__, __LINE__, taint, arg);	\
-		instrumentation_end();					\
-	} while (0)
-#else
+#ifdef __WARN_FLAGS
 #define __WARN()		__WARN_FLAGS("", BUGFLAG_TAINT(TAINT_WARN))
 
-#define __WARN_printf(taint, arg...) do {				\
-		instrumentation_begin();				\
-		__warn_printk(arg);					\
-		__WARN_FLAGS("", BUGFLAG_NO_CUT_HERE | BUGFLAG_TAINT(taint));\
-		instrumentation_end();					\
-	} while (0)
-
 #ifndef WARN_ON
 #define WARN_ON(condition) ({						\
 	int __ret_warn_on = !!(condition);				\
@@ -139,6 +125,27 @@ extern __printf(1, 2) void __warn_printk(const char *fmt, ...);
 #endif
 #endif /* __WARN_FLAGS */
 
+#if defined(__WARN_FLAGS) && !defined(__WARN_printf)
+#define __WARN_printf(taint, arg...) do {				\
+		instrumentation_begin();				\
+		__warn_printk(arg);					\
+		__WARN_FLAGS("", BUGFLAG_NO_CUT_HERE | BUGFLAG_TAINT(taint));\
+		instrumentation_end();					\
+	} while (0)
+#endif
+
+#ifndef __WARN_printf
+#define __WARN_printf(taint, arg...) do {				\
+		instrumentation_begin();				\
+		warn_slowpath_fmt(__FILE__, __LINE__, taint, arg);	\
+		instrumentation_end();					\
+	} while (0)
+#endif
+
+#ifndef __WARN
+#define __WARN()		__WARN_printf(TAINT_WARN, NULL)
+#endif
+
 /* used internally by panic.c */
 
 #ifndef WARN_ON