locking/rwsem: Move owner setting code from rwsem.c to rwsem.h

Move all the owner setting code closer to the rwsem-xadd fast paths
directly within rwsem.h file as well as in the slowpaths where owner
setting is done after acquring the lock. This will enable us to add
DEBUG_RWSEMS check in a later patch to make sure that read lock is
really acquired when rwsem_down_read_failed() returns, for instance.

Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/20190404174320.22416-3-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

kernel/locking/rwsem.c

@@ -24,7 +24,6 @@ void __sched down_read(struct rw_semaphore *sem)
 	rwsem_acquire_read(&sem->dep_map, 0, 0, _RET_IP_);
 
 	LOCK_CONTENDED(sem, __down_read_trylock, __down_read);
-	rwsem_set_reader_owned(sem);
 }
 
 EXPORT_SYMBOL(down_read);
@@ -39,7 +38,6 @@ int __sched down_read_killable(struct rw_semaphore *sem)
 		return -EINTR;
 	}
 
-	rwsem_set_reader_owned(sem);
 	return 0;
 }
 
@@ -52,10 +50,8 @@ int down_read_trylock(struct rw_semaphore *sem)
 {
 	int ret = __down_read_trylock(sem);
 
-	if (ret == 1) {
+	if (ret == 1)
 		rwsem_acquire_read(&sem->dep_map, 0, 1, _RET_IP_);
-		rwsem_set_reader_owned(sem);
-	}
 	return ret;
 }
 
@@ -70,7 +66,6 @@ void __sched down_write(struct rw_semaphore *sem)
 	rwsem_acquire(&sem->dep_map, 0, 0, _RET_IP_);
 
 	LOCK_CONTENDED(sem, __down_write_trylock, __down_write);
-	rwsem_set_owner(sem);
 }
 
 EXPORT_SYMBOL(down_write);
@@ -88,7 +83,6 @@ int __sched down_write_killable(struct rw_semaphore *sem)
 		return -EINTR;
 	}
 
-	rwsem_set_owner(sem);
 	return 0;
 }
 
@@ -101,10 +95,8 @@ int down_write_trylock(struct rw_semaphore *sem)
 {
 	int ret = __down_write_trylock(sem);
 
-	if (ret == 1) {
+	if (ret == 1)
 		rwsem_acquire(&sem->dep_map, 0, 1, _RET_IP_);
-		rwsem_set_owner(sem);
-	}
 
 	return ret;
 }
@@ -119,7 +111,6 @@ void up_read(struct rw_semaphore *sem)
 	rwsem_release(&sem->dep_map, 1, _RET_IP_);
 	DEBUG_RWSEMS_WARN_ON(!((unsigned long)sem->owner & RWSEM_READER_OWNED));
 
-	rwsem_clear_reader_owned(sem);
 	__up_read(sem);
 }
 
@@ -133,7 +124,6 @@ void up_write(struct rw_semaphore *sem)
 	rwsem_release(&sem->dep_map, 1, _RET_IP_);
 	DEBUG_RWSEMS_WARN_ON(sem->owner != current);
 
-	rwsem_clear_owner(sem);
 	__up_write(sem);
 }
 
@@ -147,7 +137,6 @@ void downgrade_write(struct rw_semaphore *sem)
 	lock_downgrade(&sem->dep_map, _RET_IP_);
 	DEBUG_RWSEMS_WARN_ON(sem->owner != current);
 
-	rwsem_set_reader_owned(sem);
 	__downgrade_write(sem);
 }
 
@@ -161,7 +150,6 @@ void down_read_nested(struct rw_semaphore *sem, int subclass)
 	rwsem_acquire_read(&sem->dep_map, subclass, 0, _RET_IP_);
 
 	LOCK_CONTENDED(sem, __down_read_trylock, __down_read);
-	rwsem_set_reader_owned(sem);
 }
 
 EXPORT_SYMBOL(down_read_nested);
@@ -172,7 +160,6 @@ void _down_write_nest_lock(struct rw_semaphore *sem, struct lockdep_map *nest)
 	rwsem_acquire_nest(&sem->dep_map, 0, 0, nest, _RET_IP_);
 
 	LOCK_CONTENDED(sem, __down_write_trylock, __down_write);
-	rwsem_set_owner(sem);
 }
 
 EXPORT_SYMBOL(_down_write_nest_lock);
@@ -193,7 +180,6 @@ void down_write_nested(struct rw_semaphore *sem, int subclass)
 	rwsem_acquire(&sem->dep_map, subclass, 0, _RET_IP_);
 
 	LOCK_CONTENDED(sem, __down_write_trylock, __down_write);
-	rwsem_set_owner(sem);
 }
 
 EXPORT_SYMBOL(down_write_nested);
@@ -208,7 +194,6 @@ int __sched down_write_killable_nested(struct rw_semaphore *sem, int subclass)
 		return -EINTR;
 	}
 
-	rwsem_set_owner(sem);
 	return 0;
 }