This function will be used in the next patch to allow a driver to set
both the message and message length of a nbcon_write_context. This is
necessary because the function also initializes the ->unsafe_takeover
struct member. By using this helper we ensure that the struct is
initialized correctly.

Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
---
 include/linux/console.h | 4 ++++
 kernel/printk/nbcon.c   | 4 ++--
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/include/linux/console.h b/include/linux/console.h
index 0d589a933b6b..81d2c247c01f 100644
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -603,6 +603,8 @@ static inline bool console_is_registered(const struct console *con)
 extern void nbcon_cpu_emergency_enter(void);
 extern void nbcon_cpu_emergency_exit(void);
 extern bool nbcon_can_proceed(struct nbcon_write_context *wctxt);
+extern void nbcon_write_context_set_buf(struct nbcon_write_context *wctxt,
+					char *buf, unsigned int len);
 extern bool nbcon_enter_unsafe(struct nbcon_write_context *wctxt);
 extern bool nbcon_exit_unsafe(struct nbcon_write_context *wctxt);
 extern void nbcon_reacquire_nobuf(struct nbcon_write_context *wctxt);
@@ -655,6 +657,8 @@ static inline bool console_is_usable(struct console *con, short flags, bool use_
 static inline void nbcon_cpu_emergency_enter(void) { }
 static inline void nbcon_cpu_emergency_exit(void) { }
 static inline bool nbcon_can_proceed(struct nbcon_write_context *wctxt) { return false; }
+static inline void nbcon_write_context_set_buf(struct nbcon_write_context *wctxt,
+					       char *buf, unsigned int len) { }
 static inline bool nbcon_enter_unsafe(struct nbcon_write_context *wctxt) { return false; }
 static inline bool nbcon_exit_unsafe(struct nbcon_write_context *wctxt) { return false; }
 static inline void nbcon_reacquire_nobuf(struct nbcon_write_context *wctxt) { }
diff --git a/kernel/printk/nbcon.c b/kernel/printk/nbcon.c
index 5be018493909..fdd1cbebe77d 100644
--- a/kernel/printk/nbcon.c
+++ b/kernel/printk/nbcon.c
@@ -854,8 +854,8 @@ static bool __nbcon_context_update_unsafe(struct nbcon_context *ctxt, bool unsaf
 	return nbcon_context_can_proceed(ctxt, &cur);
 }
 
-static void nbcon_write_context_set_buf(struct nbcon_write_context *wctxt,
-					char *buf, unsigned int len)
+void nbcon_write_context_set_buf(struct nbcon_write_context *wctxt,
+				 char *buf, unsigned int len)
 {
 	struct nbcon_context *ctxt = &ACCESS_PRIVATE(wctxt, ctxt);
 	struct console *con = ctxt->console;

-- 
2.51.0