[PATCH v2] locking: Fixup write_lock_nested() implementation.

[Sebastian Andrzej Siewior]

Andrew, please merge it into:
  locking/rwlocks: introduce write_lock_nested
  locking-rwlocks-introduce-write_lock_nested.patch

And if someone could test it, I get sh4 defconfig built with and without
lockdep. x86 seems still to build, too. So it can't be that bad.

v1…v2: I noticed a typo in _raw_write_lock_nested() and decided that it
is no needed so now it is removed for !CONFIG_INLINE_WRITE_LOCK.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
 include/linux/rwlock_api_smp.h | 1 -
 kernel/locking/spinlock.c      | 4 ++++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/linux/rwlock_api_smp.h b/include/linux/rwlock_api_smp.h
index f0c535ec4e654..dceb0a59b6927 100644
--- a/include/linux/rwlock_api_smp.h
+++ b/include/linux/rwlock_api_smp.h
@@ -47,7 +47,6 @@ _raw_write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
 
 #ifdef CONFIG_INLINE_WRITE_LOCK
 #define _raw_write_lock(lock) __raw_write_lock(lock)
-#define _raw_write_lock_nested(lock, subclass) __raw_write_lock_nested(lock, subclass)
 #endif
 
 #ifdef CONFIG_INLINE_READ_LOCK_BH
diff --git a/kernel/locking/spinlock.c b/kernel/locking/spinlock.c
index 996811efa6d6e..7f49baaa49793 100644
--- a/kernel/locking/spinlock.c
+++ b/kernel/locking/spinlock.c
@@ -301,6 +301,10 @@ void __lockfunc _raw_write_lock(rwlock_t *lock)
 }
 EXPORT_SYMBOL(_raw_write_lock);
 
+#ifndef CONFIG_DEBUG_LOCK_ALLOC
+#define __raw_write_lock_nested(lock, subclass)	__raw_write_lock(((void)(subclass), (lock)))
+#endif
+
 void __lockfunc _raw_write_lock_nested(rwlock_t *lock, int subclass)
 {
 	__raw_write_lock_nested(lock, subclass);
-- 
2.34.0