Add locking to the twe(4) driver and make it MPSAFE:

- Add per-controller configuration (sx) and I/O (mutex) locks.  The
  configuration lock protects the relationship of volumes and drives
  while the I/O lock protects access to the controller's registers and
  the main I/O path.
- Remove some checks for M_WAITOK malloc()'s failing.
- Remove the explicit bus space tag/handle from the softc and use
  bus_*() rather than bus_space_*().
- Reuse the existing new-bus sysctl context instead of creating a
  new one.
- Remove compat shims for FreeBSD 4.x.
- Use pci_enable_busmaster() rather than doing it by hand, and rely
  on bus_alloc_resource() to enable PCI I/O decoding.

Tested by:	Mike Tancsa  mike sentex net
Reviewed by:	scottl (partially)
MFC after:	1 month

1 files changed, 1 insertions, 22 deletions

diff --git a/sys/dev/twe/twevar.h b/sys/dev/twe/twevar.h
index 4990ca8..d2017aa 100644
--- a/sys/dev/twe/twevar.h
+++ b/sys/dev/twe/twevar.h
@@ -134,6 +134,7 @@ struct twe_softc
 #define TWE_STATE_SUSPEND	(1<<3)	/* controller is suspended */
 #define TWE_STATE_FRZN		(1<<4)	/* got EINPROGRESS */
 #define TWE_STATE_CTLR_BUSY	(1<<5)	/* controller cmd queue full */
+#define	TWE_STATE_DETACHING	(1<<6)	/* controller is being shut down */
     int			twe_host_id;
     struct twe_qstat	twe_qstat[TWEQ_COUNT];	/* queue statistics */
 
@@ -209,46 +210,31 @@ twe_initq_ ## name (struct twe_softc *sc)				\
 static __inline void							\
 twe_enqueue_ ## name (struct twe_request *tr)				\
 {									\
-    int		s;							\
-									\
-    s = splbio();							\
     TAILQ_INSERT_TAIL(&tr->tr_sc->twe_ ## name, tr, tr_link);		\
     TWEQ_ADD(tr->tr_sc, index);						\
-    splx(s);								\
 }									\
 static __inline void							\
 twe_requeue_ ## name (struct twe_request *tr)				\
 {									\
-    int		s;							\
-									\
-    s = splbio();							\
     TAILQ_INSERT_HEAD(&tr->tr_sc->twe_ ## name, tr, tr_link);		\
     TWEQ_ADD(tr->tr_sc, index);						\
-    splx(s);								\
 }									\
 static __inline struct twe_request *					\
 twe_dequeue_ ## name (struct twe_softc *sc)				\
 {									\
     struct twe_request	*tr;						\
-    int			s;						\
 									\
-    s = splbio();							\
     if ((tr = TAILQ_FIRST(&sc->twe_ ## name)) != NULL) {		\
 	TAILQ_REMOVE(&sc->twe_ ## name, tr, tr_link);			\
 	TWEQ_REMOVE(sc, index);						\
     }									\
-    splx(s);								\
     return(tr);								\
 }									\
 static __inline void							\
 twe_remove_ ## name (struct twe_request *tr)				\
 {									\
-    int			s;						\
-									\
-    s = splbio();							\
     TAILQ_REMOVE(&tr->tr_sc->twe_ ## name, tr, tr_link);		\
     TWEQ_REMOVE(tr->tr_sc, index);					\
-    splx(s);								\
 }
 
 TWEQ_REQUEST_QUEUE(free, TWEQ_FREE)
@@ -269,25 +255,18 @@ twe_initq_bio(struct twe_softc *sc)
 static __inline void
 twe_enqueue_bio(struct twe_softc *sc, twe_bio *bp)
 {
-    int		s;
-
-    s = splbio();
     TWE_BIO_QINSERT(sc->twe_bioq, bp);
     TWEQ_ADD(sc, TWEQ_BIO);
-    splx(s);
 }
 
 static __inline twe_bio *
 twe_dequeue_bio(struct twe_softc *sc)
 {
-    int		s;
     twe_bio	*bp;
 
-    s = splbio();
     if ((bp = TWE_BIO_QFIRST(sc->twe_bioq)) != NULL) {
 	TWE_BIO_QREMOVE(sc->twe_bioq, bp);
 	TWEQ_REMOVE(sc, TWEQ_BIO);
     }
-    splx(s);
     return(bp);
 }