4 files changed, 21 insertions, 36 deletions

diff --git a/sys/net/if_ppp.c b/sys/net/if_ppp.c
index 5030ac58..a24cd81 100644
--- a/sys/net/if_ppp.c
+++ b/sys/net/if_ppp.c
@@ -274,7 +274,8 @@ ppp_modevent(module_t mod, int type, void *data)
 		LIST_INIT(&ppp_softc_list);
 		if_clone_attach(&ppp_cloner);
 
-		netisr_register(NETISR_PPP, (netisr_t *)pppintr, NULL, 0);
+		netisr_register(NETISR_PPP, (netisr_t *)pppintr, NULL,
+		    NETISR_FORCEQUEUE);
 		/*
 		 * XXX layering violation - if_ppp can work over any lower
 		 * level transport that cares to attach to it.
@@ -1212,8 +1213,7 @@ pppintr()
     int s;
     struct mbuf *m;
 
-    GIANT_REQUIRED;
-
+    mtx_lock(&Giant);
     PPP_LIST_LOCK();
     LIST_FOREACH(sc, &ppp_softc_list, sc_list) {
 	s = splimp();
@@ -1237,6 +1237,7 @@ pppintr()
 	}
     }
     PPP_LIST_UNLOCK();
+    mtx_unlock(&Giant);
 }
 
 #ifdef PPP_COMPRESS
diff --git a/sys/net/netisr.c b/sys/net/netisr.c
index 9307b53..ed5466c 100644
--- a/sys/net/netisr.c
+++ b/sys/net/netisr.c
@@ -77,6 +77,8 @@ netisr_register(int num, netisr_t *handler, struct ifqueue *inq, int flags)
 	
 	KASSERT(!(num < 0 || num >= (sizeof(netisrs)/sizeof(*netisrs))),
 	    ("bad isr %d", num));
+	KASSERT(flags == 0 || flags == NETISR_FORCEQUEUE,
+	    ("netisr_register: bad flags 0x%x\n", flags));
 	netisrs[num].ni_handler = handler;
 	netisrs[num].ni_queue = inq;
 	netisrs[num].ni_flags = flags;
@@ -161,27 +163,18 @@ netisr_dispatch(int num, struct mbuf *m)
 		m_freem(m);
 		return;
 	}
+
 	/*
-	 * Do direct dispatch only for MPSAFE netisrs (and
-	 * only when enabled).  Note that when a netisr is
-	 * marked MPSAFE we permit multiple concurrent instances
-	 * to run.  We guarantee only the order in which
-	 * packets are processed for each "dispatch point" in
-	 * the system (i.e. call to netisr_dispatch or
-	 * netisr_queue).  This insures ordering of packets
-	 * from an interface but does not guarantee ordering
-	 * between multiple places in the system (e.g. IP
-	 * dispatched from interfaces vs. IP queued from IPSec).
+	 * Unless NETISR_FORCEQUEUE is set on the netisr (generally
+	 * indicating that the handler still requires Giant, which cannot be
+	 * acquired in arbitrary order with respect to a caller), directly
+	 * dispatch handling of this packet.  Source ordering is maintained
+	 * by virtue of callers consistently calling one of queued or direct
+	 * dispatch, and the forcequeue flag being immutable after
+	 * registration.
 	 */
-	if (netisr_direct && (ni->ni_flags & NETISR_MPSAFE)) {
+	if (netisr_direct && !(ni->ni_flags & NETISR_FORCEQUEUE)) {
 		isrstat.isrs_directed++;
-		/*
-		 * NB: We used to drain the queue before handling
-		 * the packet but now do not.  Doing so here will
-		 * not preserve ordering so instead we fallback to
-		 * guaranteeing order only from dispatch points
-		 * in the system (see above).
-		 */
 		ni->ni_handler(m);
 	} else {
 		isrstat.isrs_deferred++;
@@ -242,19 +235,10 @@ swi_net(void *dummy)
 				printf("swi_net: unregistered isr %d.\n", i);
 				continue;
 			}
-			if ((ni->ni_flags & NETISR_MPSAFE) == 0) {
-				mtx_lock(&Giant);
-				if (ni->ni_queue == NULL)
-					ni->ni_handler(NULL);
-				else
-					netisr_processqueue(ni);
-				mtx_unlock(&Giant);
-			} else {
-				if (ni->ni_queue == NULL)
-					ni->ni_handler(NULL);
-				else
-					netisr_processqueue(ni);
-			}
+			if (ni->ni_queue == NULL)
+				ni->ni_handler(NULL);
+			else
+				netisr_processqueue(ni);
 		}
 	} while (polling);
 }
diff --git a/sys/net/netisr.h b/sys/net/netisr.h
index 1fb411c..d5bd8e7 100644
--- a/sys/net/netisr.h
+++ b/sys/net/netisr.h
@@ -83,7 +83,7 @@ typedef void netisr_t (struct mbuf *);
   
 void	netisr_dispatch(int, struct mbuf *);
 int	netisr_queue(int, struct mbuf *);
-#define	NETISR_MPSAFE	0x0001		/* ISR does not need Giant */
+#define	NETISR_FORCEQUEUE	0x0002		/* Force queued dispatch. */
 void	netisr_register(int, netisr_t *, struct ifqueue *, int);
 void	netisr_unregister(int);
 
diff --git a/sys/net/rtsock.c b/sys/net/rtsock.c
index 9511035..99e0257 100644
--- a/sys/net/rtsock.c
+++ b/sys/net/rtsock.c
@@ -117,7 +117,7 @@ rts_init(void)
 	if (TUNABLE_INT_FETCH("net.route.netisr_maxqlen", &tmp))
 		rtsintrq.ifq_maxlen = tmp;
 	mtx_init(&rtsintrq.ifq_mtx, "rts_inq", NULL, MTX_DEF);
-	netisr_register(NETISR_ROUTE, rts_input, &rtsintrq, NETISR_MPSAFE);
+	netisr_register(NETISR_ROUTE, rts_input, &rtsintrq, 0);
 }
 SYSINIT(rtsock, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, rts_init, 0);