Sync netmap sources with the version in our private tree.

This commit contains large contributions from Giuseppe Lettieri and
Stefano Garzarella, is partly supported by grants from Verisign and Cisco,
and brings in the following:

- fix zerocopy monitor ports and introduce copying monitor ports
  (the latter are lower performance but give access to all traffic
  in parallel with the application)

- exclusive open mode, useful to implement solutions that recover
  from crashes of the main netmap client (suggested by Patrick Kelsey)

- revised memory allocator in preparation for the 'passthrough mode'
  (ptnetmap) recently presented at bsdcan. ptnetmap is described in
        S. Garzarella, G. Lettieri, L. Rizzo;
        Virtual device passthrough for high speed VM networking,
        ACM/IEEE ANCS 2015, Oakland (CA) May 2015
        http://info.iet.unipi.it/~luigi/research.html

- fix rx CRC handing on ixl

- add module dependencies for netmap when building drivers as modules

- minor simplifications to device-specific routines (*txsync, *rxsync)

- general code cleanup (remove unused variables, introduce macros
  to access rings and remove duplicate code,

Applications do not need to be recompiled, unless of course
they want to use the new features (monitors and exclusive open).

Those willing to try this code on stable/10 can just update the
sys/dev/netmap/*, sys/net/netmap* with the version in HEAD
and apply the small patches to individual device drivers.

MFC after:	1 month
Sponsored by:	(partly) Verisign, Cisco

1 files changed, 16 insertions, 14 deletions

diff --git a/sys/dev/netmap/netmap_generic.c b/sys/dev/netmap/netmap_generic.c
index ecdb36824077..bc5b452cfaae 100644
--- a/sys/dev/netmap/netmap_generic.c
+++ b/sys/dev/netmap/netmap_generic.c
@@ -305,7 +305,7 @@ generic_netmap_register(struct netmap_adapter *na, int enable)
 		}
 		rtnl_lock();
 		/* Prepare to intercept incoming traffic. */
-		error = netmap_catch_rx(na, 1);
+		error = netmap_catch_rx(gna, 1);
 		if (error) {
 			D("netdev_rx_handler_register() failed (%d)", error);
 			goto register_handler;
@@ -342,7 +342,7 @@ generic_netmap_register(struct netmap_adapter *na, int enable)
 		netmap_catch_tx(gna, 0);
 
 		/* Do not intercept packets on the rx path. */
-		netmap_catch_rx(na, 0);
+		netmap_catch_rx(gna, 0);
 
 		rtnl_unlock();
 
@@ -645,8 +645,6 @@ generic_netmap_txsync(struct netmap_kring *kring, int flags)
 
 	generic_netmap_tx_clean(kring);
 
-	nm_txsync_finalize(kring);
-
 	return 0;
 }
 
@@ -711,7 +709,7 @@ generic_netmap_rxsync(struct netmap_kring *kring, int flags)
 	u_int nm_i;	/* index into the netmap ring */ //j,
 	u_int n;
 	u_int const lim = kring->nkr_num_slots - 1;
-	u_int const head = nm_rxsync_prologue(kring);
+	u_int const head = kring->rhead;
 	int force_update = (flags & NAF_FORCE_READ) || kring->nr_kflags & NKR_PENDINTR;
 
 	if (head > lim)
@@ -774,8 +772,6 @@ generic_netmap_rxsync(struct netmap_kring *kring, int flags)
 		}
 		kring->nr_hwcur = head;
 	}
-	/* tell userspace that there might be new packets. */
-	nm_rxsync_finalize(kring);
 	IFRATE(rate_ctx.new.rxsync++);
 
 	return 0;
@@ -784,20 +780,25 @@ generic_netmap_rxsync(struct netmap_kring *kring, int flags)
 static void
 generic_netmap_dtor(struct netmap_adapter *na)
 {
-	struct ifnet *ifp = na->ifp;
 	struct netmap_generic_adapter *gna = (struct netmap_generic_adapter*)na;
+	struct ifnet *ifp = netmap_generic_getifp(gna);
 	struct netmap_adapter *prev_na = gna->prev;
 
 	if (prev_na != NULL) {
 		D("Released generic NA %p", gna);
-		if_rele(na->ifp);
+		if_rele(ifp);
 		netmap_adapter_put(prev_na);
+		if (na->ifp == NULL) {
+		        /*
+		         * The driver has been removed without releasing
+		         * the reference so we need to do it here.
+		         */
+		        netmap_adapter_put(prev_na);
+		}
 	}
-	if (ifp != NULL) {
-		WNA(ifp) = prev_na;
-		D("Restored native NA %p", prev_na);
-		na->ifp = NULL;
-	}
+	WNA(ifp) = prev_na;
+	D("Restored native NA %p", prev_na);
+	na->ifp = NULL;
 }
 
 /*
@@ -834,6 +835,7 @@ generic_netmap_attach(struct ifnet *ifp)
 		return ENOMEM;
 	}
 	na = (struct netmap_adapter *)gna;
+	strncpy(na->name, ifp->if_xname, sizeof(na->name));
 	na->ifp = ifp;
 	na->num_tx_desc = num_tx_desc;
 	na->num_rx_desc = num_rx_desc;