Change and clean the mutex lock interface.

mtx_enter(lock, type) becomes:

mtx_lock(lock) for sleep locks (MTX_DEF-initialized locks)
mtx_lock_spin(lock) for spin locks (MTX_SPIN-initialized)

similarily, for releasing a lock, we now have:

mtx_unlock(lock) for MTX_DEF and mtx_unlock_spin(lock) for MTX_SPIN.
We change the caller interface for the two different types of locks
because the semantics are entirely different for each case, and this
makes it explicitly clear and, at the same time, it rids us of the
extra `type' argument.

The enter->lock and exit->unlock change has been made with the idea
that we're "locking data" and not "entering locked code" in mind.

Further, remove all additional "flags" previously passed to the
lock acquire/release routines with the exception of two:

MTX_QUIET and MTX_NOSWITCH

The functionality of these flags is preserved and they can be passed
to the lock/unlock routines by calling the corresponding wrappers:

mtx_{lock, unlock}_flags(lock, flag(s)) and
mtx_{lock, unlock}_spin_flags(lock, flag(s)) for MTX_DEF and MTX_SPIN
locks, respectively.

Re-inline some lock acq/rel code; in the sleep lock case, we only
inline the _obtain_lock()s in order to ensure that the inlined code
fits into a cache line. In the spin lock case, we inline recursion and
actually only perform a function call if we need to spin. This change
has been made with the idea that we generally tend to avoid spin locks
and that also the spin locks that we do have and are heavily used
(i.e. sched_lock) do recurse, and therefore in an effort to reduce
function call overhead for some architectures (such as alpha), we
inline recursion for this case.

Create a new malloc type for the witness code and retire from using
the M_DEV type. The new type is called M_WITNESS and is only declared
if WITNESS is enabled.

Begin cleaning up some machdep/mutex.h code - specifically updated the
"optimized" inlined code in alpha/mutex.h and wrote MTX_LOCK_SPIN
and MTX_UNLOCK_SPIN asm macros for the i386/mutex.h as we presently
need those.

Finally, caught up to the interface changes in all sys code.

Contributors: jake, jhb, jasone (in no particular order)

3 files changed, 6 insertions, 6 deletions

diff --git a/sys/dev/usb/if_auereg.h b/sys/dev/usb/if_auereg.h
index 5558b50..5544091 100644
--- a/sys/dev/usb/if_auereg.h
+++ b/sys/dev/usb/if_auereg.h
@@ -249,8 +249,8 @@ struct aue_softc {
 	struct mtx		aue_mtx;
 };
 
-#define	AUE_LOCK(_sc)		mtx_enter(&(_sc)->aue_mtx, MTX_DEF)
-#define	AUE_UNLOCK(_sc)		mtx_exit(&(_sc)->aue_mtx, MTX_DEF)
+#define	AUE_LOCK(_sc)		mtx_lock(&(_sc)->aue_mtx)
+#define	AUE_UNLOCK(_sc)		mtx_unlock(&(_sc)->aue_mtx)
 
 #define AUE_TIMEOUT		1000
 #define ETHER_ALIGN		2
diff --git a/sys/dev/usb/if_cuereg.h b/sys/dev/usb/if_cuereg.h
index 5d043e4..dc7b8c8 100644
--- a/sys/dev/usb/if_cuereg.h
+++ b/sys/dev/usb/if_cuereg.h
@@ -182,5 +182,5 @@ struct cue_softc {
 	struct mtx		cue_mtx;
 };
 
-#define	CUE_LOCK(_sc)		mtx_enter(&(_sc)->cue_mtx, MTX_DEF)
-#define	CUE_UNLOCK(_sc)		mtx_exit(&(_sc)->cue_mtx, MTX_DEF)
+#define	CUE_LOCK(_sc)		mtx_lock(&(_sc)->cue_mtx)
+#define	CUE_UNLOCK(_sc)		mtx_unlock(&(_sc)->cue_mtx)
diff --git a/sys/dev/usb/if_kuereg.h b/sys/dev/usb/if_kuereg.h
index 49cd235..b5ffb32 100644
--- a/sys/dev/usb/if_kuereg.h
+++ b/sys/dev/usb/if_kuereg.h
@@ -173,5 +173,5 @@ struct kue_softc {
 	struct mtx		kue_mtx;
 };
 
-#define	KUE_LOCK(_sc)		mtx_enter(&(_sc)->kue_mtx, MTX_DEF)
-#define	KUE_UNLOCK(_sc)		mtx_exit(&(_sc)->kue_mtx, MTX_DEF)
+#define	KUE_LOCK(_sc)		mtx_lock(&(_sc)->kue_mtx)
+#define	KUE_UNLOCK(_sc)		mtx_unlock(&(_sc)->kue_mtx)