sched: Provide raw_spin_rq_*lock*() helpers

In prepration for playing games with rq->lock, add some rq_lock
wrappers.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Don Hiatt <dhiatt@digitalocean.com>
Tested-by: Hongyu Ning <hongyu.ning@linux.intel.com>
Tested-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20210422123308.075967879@infradead.org

kernel/sched/core.c

@@ -184,6 +184,21 @@ int sysctl_sched_rt_runtime = 950000;
  *
  */
 
+void raw_spin_rq_lock_nested(struct rq *rq, int subclass)
+{
+	raw_spin_lock_nested(rq_lockp(rq), subclass);
+}
+
+bool raw_spin_rq_trylock(struct rq *rq)
+{
+	return raw_spin_trylock(rq_lockp(rq));
+}
+
+void raw_spin_rq_unlock(struct rq *rq)
+{
+	raw_spin_unlock(rq_lockp(rq));
+}
+
 /*
  * __task_rq_lock - lock the rq @p resides on.
  */

kernel/sched/sched.h

@@ -1113,6 +1113,56 @@ static inline bool is_migration_disabled(struct task_struct *p)
 #endif
 }
 
+static inline raw_spinlock_t *rq_lockp(struct rq *rq)
+{
+	return &rq->lock;
+}
+
+static inline void lockdep_assert_rq_held(struct rq *rq)
+{
+	lockdep_assert_held(rq_lockp(rq));
+}
+
+extern void raw_spin_rq_lock_nested(struct rq *rq, int subclass);
+extern bool raw_spin_rq_trylock(struct rq *rq);
+extern void raw_spin_rq_unlock(struct rq *rq);
+
+static inline void raw_spin_rq_lock(struct rq *rq)
+{
+	raw_spin_rq_lock_nested(rq, 0);
+}
+
+static inline void raw_spin_rq_lock_irq(struct rq *rq)
+{
+	local_irq_disable();
+	raw_spin_rq_lock(rq);
+}
+
+static inline void raw_spin_rq_unlock_irq(struct rq *rq)
+{
+	raw_spin_rq_unlock(rq);
+	local_irq_enable();
+}
+
+static inline unsigned long _raw_spin_rq_lock_irqsave(struct rq *rq)
+{
+	unsigned long flags;
+	local_irq_save(flags);
+	raw_spin_rq_lock(rq);
+	return flags;
+}
+
+static inline void raw_spin_rq_unlock_irqrestore(struct rq *rq, unsigned long flags)
+{
+	raw_spin_rq_unlock(rq);
+	local_irq_restore(flags);
+}
+
+#define raw_spin_rq_lock_irqsave(rq, flags)	\
+do {						\
+	flags = _raw_spin_rq_lock_irqsave(rq);	\
+} while (0)
+
 #ifdef CONFIG_SCHED_SMT
 extern void __update_idle_core(struct rq *rq);