[PATCH v2] rust: Fix build error

[Eder Zulian <ezulian@redhat.com>]

On a PREEMPT_RT build, spin locks have been mapped to rt_mutex types, so
avoid the raw_spinlock_init call for RT.

When CONFIG_DEBUG_SPINLOCK=y and CONFIG_PREEMPT_RT=y the following build
error occurs:

https://lore.kernel.org/oe-kbuild-all/202409251238.vetlgXE9-lkp@intel.com/

Fixes: 876346536c1b ("rust: kbuild: split up helpers.c")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202409251238.vetlgXE9-lkp@intel.com/
Signed-off-by: Eder Zulian <ezulian@redhat.com>
---
V1 -> V2: Cleaned up style and addressed review comments
 include/linux/spinlock_rt.h | 15 +++++++--------
 rust/helpers/spinlock.c     |  8 ++++++--
 2 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/include/linux/spinlock_rt.h b/include/linux/spinlock_rt.h
index f9f14e135be7..f6499c37157d 100644
--- a/include/linux/spinlock_rt.h
+++ b/include/linux/spinlock_rt.h
@@ -16,22 +16,21 @@ static inline void __rt_spin_lock_init(spinlock_t *lock, const char *name,
 }
 #endif
 
-#define spin_lock_init(slock)					\
+#define __spin_lock_init(slock, name, key, percpu)		\
 do {								\
-	static struct lock_class_key __key;			\
-								\
 	rt_mutex_base_init(&(slock)->lock);			\
-	__rt_spin_lock_init(slock, #slock, &__key, false);	\
+	__rt_spin_lock_init(slock, name, key, percpu);		\
 } while (0)
 
-#define local_spin_lock_init(slock)				\
+#define _spin_lock_init(slock, percpu)				\
 do {								\
 	static struct lock_class_key __key;			\
-								\
-	rt_mutex_base_init(&(slock)->lock);			\
-	__rt_spin_lock_init(slock, #slock, &__key, true);	\
+	__spin_lock_init(slock, #slock, &__key, percpu);	\
 } while (0)
 
+#define spin_lock_init(slock)		_spin_lock_init(slock, false)
+#define local_spin_lock_init(slock)	_spin_lock_init(slock, true)
+
 extern void rt_spin_lock(spinlock_t *lock) __acquires(lock);
 extern void rt_spin_lock_nested(spinlock_t *lock, int subclass)	__acquires(lock);
 extern void rt_spin_lock_nest_lock(spinlock_t *lock, struct lockdep_map *nest_lock) __acquires(lock);
diff --git a/rust/helpers/spinlock.c b/rust/helpers/spinlock.c
index b7b0945e8b3c..5971fdf6f755 100644
--- a/rust/helpers/spinlock.c
+++ b/rust/helpers/spinlock.c
@@ -6,10 +6,14 @@ void rust_helper___spin_lock_init(spinlock_t *lock, const char *name,
 				  struct lock_class_key *key)
 {
 #ifdef CONFIG_DEBUG_SPINLOCK
+# if defined(CONFIG_PREEMPT_RT)
+	__spin_lock_init(lock, name, key, false);
+# else /*!CONFIG_PREEMPT_RT */
 	__raw_spin_lock_init(spinlock_check(lock), name, key, LD_WAIT_CONFIG);
-#else
+# endif /* CONFIG_PREEMPT_RT */
+#else /* !CONFIG_DEBUG_SPINLOCK */
 	spin_lock_init(lock);
-#endif
+#endif /* CONFIG_DEBUG_SPINLOCK */
 }
 
 void rust_helper_spin_lock(spinlock_t *lock)
-- 
2.47.0