Lock down netnatm and mark as MPSAFE:

- Introduce a subsystem mutex, natm_mtx, manipulated with accessor macros
  NATM_LOCK_INIT(), NATM_LOCK(), NATM_UNLOCK(), NATM_LOCK_ASSERT().  It
  protects the consistency of pcb-related data structures.  Finer grained
  locking is possible, but should be done in the context of specific
  measurements (as very little work is done in netnatm -- most is in the
  ATM device driver or socket layer, so there's probably not much
  contention).

- Remove GIANT_REQUIRED, mark as NETISR_MPSAFE, remove
  NET_NEEDS_GIANT("netnatm").

- Conditionally acquire Giant when entering network interfaces for
  ifp->if_ioctl() using IFF_LOCKGIANT(ifp)/IFF_UNLOCKGIANT(ifp) in order
  to coexist with non-MPSAFE atm ifnet drivers..

- De-spl.

MFC after:	2 weeks
Reviewed by:	harti, bms (various versions)

1 files changed, 2 insertions, 3 deletions

diff --git a/sys/netnatm/natm_proto.c b/sys/netnatm/natm_proto.c
index 7e3ec35..235ccc0 100644
--- a/sys/netnatm/natm_proto.c
+++ b/sys/netnatm/natm_proto.c
@@ -56,8 +56,6 @@ extern	struct domain natmdomain;
 
 static	void natm_init(void);
 
-NET_NEEDS_GIANT("netnatm");
-
 static struct protosw natmsw[] = {
 { SOCK_STREAM,	&natmdomain,	PROTO_NATMAAL5, PR_CONNREQUIRED,
   0,	0,	0,	0,
@@ -123,8 +121,9 @@ natm_init(void)
 	LIST_INIT(&natm_pcbs);
 	bzero(&natmintrq, sizeof(natmintrq));
 	natmintrq.ifq_maxlen = natmqmaxlen;
+	NATM_LOCK_INIT();
 	mtx_init(&natmintrq.ifq_mtx, "natm_inq", NULL, MTX_DEF);
-	netisr_register(NETISR_NATM, natmintr, &natmintrq, 0);
+	netisr_register(NETISR_NATM, natmintr, &natmintrq, NETISR_MPSAFE);
 }
 
 #if defined(__FreeBSD__)