locking/rtmutex: Add mutex variant for RT

Add the necessary defines, helpers and API functions for replacing struct mutex on
a PREEMPT_RT enabled kernel with an rtmutex based variant.

No functional change when CONFIG_PREEMPT_RT=n

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/20210815211305.081517417@linutronix.de
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 5ddd575..e5cdf98 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1235,7 +1235,7 @@
 	depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
 	select LOCKDEP
 	select DEBUG_SPINLOCK
-	select DEBUG_MUTEXES
+	select DEBUG_MUTEXES if !PREEMPT_RT
 	select DEBUG_RT_MUTEXES if RT_MUTEXES
 	select DEBUG_RWSEMS
 	select DEBUG_WW_MUTEX_SLOWPATH
@@ -1299,7 +1299,7 @@
 	depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
 	select LOCKDEP
 	select DEBUG_SPINLOCK
-	select DEBUG_MUTEXES
+	select DEBUG_MUTEXES if !PREEMPT_RT
 	select DEBUG_RT_MUTEXES if RT_MUTEXES
 	select DEBUG_LOCK_ALLOC
 	default n
@@ -1335,7 +1335,7 @@
 
 config DEBUG_MUTEXES
 	bool "Mutex debugging: basic checks"
-	depends on DEBUG_KERNEL
+	depends on DEBUG_KERNEL && !PREEMPT_RT
 	help
 	 This feature allows mutex semantics violations to be detected and
 	 reported.
@@ -1345,7 +1345,8 @@
 	depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
 	select DEBUG_LOCK_ALLOC
 	select DEBUG_SPINLOCK
-	select DEBUG_MUTEXES
+	select DEBUG_MUTEXES if !PREEMPT_RT
+	select DEBUG_RT_MUTEXES if PREEMPT_RT
 	help
 	 This feature enables slowpath testing for w/w mutex users by
 	 injecting additional -EDEADLK wound/backoff cases. Together with
@@ -1368,7 +1369,7 @@
 	bool "Lock debugging: detect incorrect freeing of live locks"
 	depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
 	select DEBUG_SPINLOCK
-	select DEBUG_MUTEXES
+	select DEBUG_MUTEXES if !PREEMPT_RT
 	select DEBUG_RT_MUTEXES if RT_MUTEXES
 	select LOCKDEP
 	help