locking: add lockevent_read() prototype

lockevent_read() has a __weak definition and the only caller in
kernel/locking/lock_events.c, plus a strong definition in qspinlock_stat.h
that overrides it, but no other declaration.  This causes a W=1 warning:

kernel/locking/lock_events.c:61:16: error: no previous prototype for 'lockevent_read' [-Werror=missing-prototypes]

Add shared prototype to avoid the warnings.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnd Bergmann <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Dennis Zhou <[email protected]>
Cc: Eric Paris <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Michal Simek <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Paul Moore <[email protected]>
Cc: Pavel Machek <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: Russell King <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Thomas Bogendoerfer <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Waiman Long <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

1 files changed, 4 insertions, 0 deletions

diff --git a/kernel/locking/lock_events.h b/kernel/locking/lock_events.h
index 8c7e7d25f09c..a6016b91803d 100644
--- a/kernel/locking/lock_events.h
+++ b/kernel/locking/lock_events.h
@@ -57,4 +57,8 @@ static inline void __lockevent_add(enum lock_events event, int inc)
 #define lockevent_cond_inc(ev, c)
 
 #endif /* CONFIG_LOCK_EVENT_COUNTS */
+
+ssize_t lockevent_read(struct file *file, char __user *user_buf,
+		       size_t count, loff_t *ppos);
+
 #endif /* __LOCKING_LOCK_EVENTS_H */