netmap: import changes from upstream

- make sure rings are disabled during resets
 - introduce netmap_update_hostrings_mode(), with support
   for multiple host rings
 - always initialize ni_bufs_head in netmap_if
      ni_bufs_head was not properly initialized when no external buffers were
      requestedx and contained the ni_bufs_head from the last request. This
      was causing spurious buffer frees when alternating between apps that
      used external buffers and apps that did not use them.
 - check na validitity under lock on detach
 - netmap_mem: fix leak on error path
 - nm_dispatch: fix compilation on Raspberry Pi

MFC after:	2 weeks

sys/dev/netmap/netmap.c

@@ -1002,6 +1002,22 @@ netmap_mem_drop(struct netmap_adapter *na)
 	}
 }
 
+static void
+netmap_update_hostrings_mode(struct netmap_adapter *na)
+{
+	enum txrx t;
+	struct netmap_kring *kring;
+	int i;
+
+	for_rx_tx(t) {
+		for (i = nma_get_nrings(na, t);
+		     i < netmap_real_rings(na, t); i++) {
+			kring = NMR(na, t)[i];
+			kring->nr_mode = kring->nr_pending_mode;
+		}
+	}
+}
+
 /*
  * Undo everything that was done in netmap_do_regif(). In particular,
  * call nm_register(ifp,0) to stop netmap mode on the interface and
@@ -1032,7 +1048,9 @@ netmap_do_unregif(struct netmap_priv_d *priv)
 #endif
 
 	if (na->active_fds <= 0 || nm_kring_pending(priv)) {
+		netmap_set_all_rings(na, NM_KR_LOCKED);
 		na->nm_register(na, 0);
+		netmap_set_all_rings(na, 0);
 	}
 
 	/* delete rings and buffers that are no longer needed */
@@ -2630,7 +2648,9 @@ netmap_do_regif(struct netmap_priv_d *priv, struct netmap_adapter *na,
 	if (nm_kring_pending(priv)) {
 		/* Some kring is switching mode, tell the adapter to
 		 * react on this. */
+		netmap_set_all_rings(na, NM_KR_LOCKED);
 		error = na->nm_register(na, 1);
+		netmap_set_all_rings(na, 0);
 		if (error)
 			goto err_del_if;
 	}
@@ -2858,6 +2878,8 @@ netmap_ioctl(struct netmap_priv_d *priv, u_long cmd, caddr_t data,
 						&nifp->ni_bufs_head, req->nr_extra_bufs);
 					if (netmap_verbose)
 						nm_prinf("got %d extra buffers", req->nr_extra_bufs);
+				} else {
+					nifp->ni_bufs_head = 0;
 				}
 				req->nr_offset = netmap_mem_if_offset(na->nm_mem, nifp);
 
@@ -4178,12 +4200,16 @@ netmap_hw_krings_create(struct netmap_adapter *na)
 void
 netmap_detach(struct ifnet *ifp)
 {
-	struct netmap_adapter *na = NA(ifp);
-
-	if (!na)
-		return;
+	struct netmap_adapter *na;
 
 	NMG_LOCK();
+
+	if (!NM_NA_VALID(ifp)) {
+		NMG_UNLOCK();
+		return;
+	}
+
+	na = NA(ifp);
 	netmap_set_all_rings(na, NM_KR_LOCKED);
 	/*
 	 * if the netmap adapter is not native, somebody
@@ -4491,7 +4517,7 @@ nm_set_native_flags(struct netmap_adapter *na)
 
 	na->na_flags |= NAF_NETMAP_ON;
 	nm_os_onenter(ifp);
-	nm_update_hostrings_mode(na);
+	netmap_update_hostrings_mode(na);
 }
 
 void
@@ -4505,7 +4531,7 @@ nm_clear_native_flags(struct netmap_adapter *na)
 		return;
 	}
 
-	nm_update_hostrings_mode(na);
+	netmap_update_hostrings_mode(na);
 	nm_os_onexit(ifp);
 
 	na->na_flags &= ~NAF_NETMAP_ON;

sys/dev/netmap/netmap_kern.h

@@ -1435,16 +1435,6 @@ nm_iszombie(struct netmap_adapter *na)
 	return na == NULL || (na->na_flags & NAF_ZOMBIE);
 }
 
-static inline void
-nm_update_hostrings_mode(struct netmap_adapter *na)
-{
-	/* Process nr_mode and nr_pending_mode for host rings. */
-	na->tx_rings[na->num_tx_rings]->nr_mode =
-		na->tx_rings[na->num_tx_rings]->nr_pending_mode;
-	na->rx_rings[na->num_rx_rings]->nr_mode =
-		na->rx_rings[na->num_rx_rings]->nr_pending_mode;
-}
-
 void nm_set_native_flags(struct netmap_adapter *);
 void nm_clear_native_flags(struct netmap_adapter *);
 

sys/dev/netmap/netmap_mem2.c

@@ -1706,7 +1706,7 @@ _netmap_mem_private_new(size_t size, struct netmap_obj_params *p, int grp_id,
 			if (memtotal < poolsz) {
 				nm_prerr("%s: request too large", d->pools[i].name);
 				err = ENOMEM;
-				goto error;
+				goto error_rel_id;
 			}
 			memtotal -= poolsz;
 		}
@@ -1731,14 +1731,15 @@ _netmap_mem_private_new(size_t size, struct netmap_obj_params *p, int grp_id,
 
 	err = netmap_mem_config(d);
 	if (err)
-		goto error_rel_id;
+		goto error_destroy_lock;
 
 	d->flags &= ~NETMAP_MEM_FINALIZED;
 
 	return d;
 
-error_rel_id:
+error_destroy_lock:
 	NMA_LOCK_DESTROY(d);
+error_rel_id:
 	nm_mem_release_id(d);
 error_free:
 	nm_os_free(d);

sys/net/netmap_user.h

@@ -1131,7 +1131,7 @@ nm_dispatch(struct nm_desc *d, int cnt, nm_cb_t cb, u_char *arg)
 				slot = &ring->slot[i];
 				d->hdr.len += slot->len;
 				nbuf = (u_char *)NETMAP_BUF(ring, slot->buf_idx);
-				if (oldbuf != NULL && nbuf - oldbuf == ring->nr_buf_size &&
+				if (oldbuf != NULL && (uint32_t)(nbuf - oldbuf) == ring->nr_buf_size &&
 						oldlen == ring->nr_buf_size) {
 					d->hdr.caplen += slot->len;
 					oldbuf = nbuf;