Introduce macro stubs in the mutex implementation that will be always

defined and will allow consumers, willing to provide options, file and
line to locking requests, to not worry about options redefining the
interfaces.
This is typically useful when there is the need to build another
locking interface on top of the mutex one.

The introduced functions that consumers can use are:
- mtx_lock_flags_
- mtx_unlock_flags_
- mtx_lock_spin_flags_
- mtx_unlock_spin_flags_
- mtx_assert_
- thread_lock_flags_

Spare notes:
- Likely we can get rid of all the 'INVARIANTS' specification in the
  ppbus code by using the same macro as done in this patch (but this is
  left to the ppbus maintainer)
- all the other locking interfaces may require a similar cleanup, where
  the most notable case is sx which will allow a further cleanup of
  vm_map locking facilities
- The patch should be fully compatible with older branches, thus a MFC
  is previewed (infact it uses all the underlying mechanisms already
  present).

Comments review by:	eadler, Ben Kaduk
Discussed with:		kib, jhb
MFC after:	1 month

1 files changed, 2 insertions, 2 deletions

diff --git a/sys/kern/kern_mutex.c b/sys/kern/kern_mutex.c
index 7666116..eddb0d3 100644
--- a/sys/kern/kern_mutex.c
+++ b/sys/kern/kern_mutex.c
@@ -274,7 +274,7 @@ _mtx_unlock_spin_flags(struct mtx *m, int opts, const char *file, int line)
  * is already owned, it will recursively acquire the lock.
  */
 int
-_mtx_trylock(struct mtx *m, int opts, const char *file, int line)
+mtx_trylock_flags_(struct mtx *m, int opts, const char *file, int line)
 {
 #ifdef LOCK_PROFILING
 	uint64_t waittime = 0;
@@ -540,7 +540,7 @@ _mtx_lock_spin(struct mtx *m, uintptr_t tid, int opts, const char *file,
 #endif /* SMP */
 
 void
-_thread_lock_flags(struct thread *td, int opts, const char *file, int line)
+thread_lock_flags_(struct thread *td, int opts, const char *file, int line)
 {
 	struct mtx *m;
 	uintptr_t tid;