[OS-BUILD PATCHv3] rust: Fix build error

[Eder Zulian (via Email Bridge)]

From: Eder Zulian

rust: Fix build error

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/[e-mail]/

Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/[e-mail]/
Signed-off-by: Eder Zulian

diff --git a/include/linux/spinlock_rt.h b/include/linux/spinlock_rt.h
index blahblah..blahblah 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);
 extern void rt_spin_lock_nested(spinlock_t *lock, int subclass);
 extern void rt_spin_lock_nest_lock(spinlock_t *lock, struct lockdep_map *nest_lock);
diff --git a/rust/helpers/spinlock.c b/rust/helpers/spinlock.c
index blahblah..blahblah 100644
--- a/rust/helpers/spinlock.c
+++ b/rust/helpers/spinlock.c
@@ -7,10 +7,16 @@ void rust_helper___spin_lock_init(spinlock_t *lock, const char *name,
    			  struct lock_class_key *key)
 {
 #ifdef CONFIG_DEBUG_SPINLOCK
+
+#ifdef 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)

--
https://gitlab.com/cki-project/kernel-ark/-/merge_requests/3471

[Eder Zulian (via Email Bridge)]

From: Eder Zulian on gitlab.com
https://gitlab.com/cki-project/kernel-ark/-/merge_requests/3471#note_2203476...

Latest version has been merged into locking/core branch of tip:

https://lore.kernel.org/all/173132268241.32228.2951825322377955708.tip-
bot2@tip-bot2/