locking/ww_mutex: Implement rt_mutex accessors

Provide the type defines and the helper inlines for rtmutex based ww_mutexes.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.790760545@linutronix.de

diff --git a/kernel/locking/ww_mutex.h b/kernel/locking/ww_mutex.h
index 309f3e4..7da9890 100644 (file)
--- a/kernel/locking/ww_mutex.h
+++ b/kernel/locking/ww_mutex.h
@@ -1,5 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
+#ifndef WW_RT
+
 #define MUTEX          mutex
 #define MUTEX_WAITER   mutex_waiter
 
@@ -83,6 +85,82 @@ static inline void lockdep_assert_wait_lock_held(struct mutex *lock)
        lockdep_assert_held(&lock->wait_lock);
 }
 
+#else /* WW_RT */
+
+#define MUTEX          rt_mutex
+#define MUTEX_WAITER   rt_mutex_waiter
+
+static inline struct rt_mutex_waiter *
+__ww_waiter_first(struct rt_mutex *lock)
+{
+       struct rb_node *n = rb_first(&lock->rtmutex.waiters.rb_root);
+       if (!n)
+               return NULL;
+       return rb_entry(n, struct rt_mutex_waiter, tree_entry);
+}
+
+static inline struct rt_mutex_waiter *
+__ww_waiter_next(struct rt_mutex *lock, struct rt_mutex_waiter *w)
+{
+       struct rb_node *n = rb_next(&w->tree_entry);
+       if (!n)
+               return NULL;
+       return rb_entry(n, struct rt_mutex_waiter, tree_entry);
+}
+
+static inline struct rt_mutex_waiter *
+__ww_waiter_prev(struct rt_mutex *lock, struct rt_mutex_waiter *w)
+{
+       struct rb_node *n = rb_prev(&w->tree_entry);
+       if (!n)
+               return NULL;
+       return rb_entry(n, struct rt_mutex_waiter, tree_entry);
+}
+
+static inline struct rt_mutex_waiter *
+__ww_waiter_last(struct rt_mutex *lock)
+{
+       struct rb_node *n = rb_last(&lock->rtmutex.waiters.rb_root);
+       if (!n)
+               return NULL;
+       return rb_entry(n, struct rt_mutex_waiter, tree_entry);
+}
+
+static inline void
+__ww_waiter_add(struct rt_mutex *lock, struct rt_mutex_waiter *waiter, struct rt_mutex_waiter *pos)
+{
+       /* RT unconditionally adds the waiter first and then removes it on error */
+}
+
+static inline struct task_struct *
+__ww_mutex_owner(struct rt_mutex *lock)
+{
+       return rt_mutex_owner(&lock->rtmutex);
+}
+
+static inline bool
+__ww_mutex_has_waiters(struct rt_mutex *lock)
+{
+       return rt_mutex_has_waiters(&lock->rtmutex);
+}
+
+static inline void lock_wait_lock(struct rt_mutex *lock)
+{
+       raw_spin_lock(&lock->rtmutex.wait_lock);
+}
+
+static inline void unlock_wait_lock(struct rt_mutex *lock)
+{
+       raw_spin_unlock(&lock->rtmutex.wait_lock);
+}
+
+static inline void lockdep_assert_wait_lock_held(struct rt_mutex *lock)
+{
+       lockdep_assert_held(&lock->rtmutex.wait_lock);
+}
+
+#endif /* WW_RT */
+
 /*
  * Wait-Die:
  *   The newer transactions are killed when:
@@ -169,7 +247,9 @@ __ww_mutex_die(struct MUTEX *lock, struct MUTEX_WAITER *waiter,
 
        if (waiter->ww_ctx->acquired > 0 &&
                        __ww_ctx_stamp_after(waiter->ww_ctx, ww_ctx)) {
+#ifndef WW_RT
                debug_mutex_wake_waiter(lock, waiter);
+#endif
                wake_up_process(waiter->task);
        }