[src/trunk]: src/sys/net Simplify bridge(4)

[ozaki-r <ozaki-r%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/38490e70444e
branches:  trunk
changeset: 343569:38490e70444e
user:      ozaki-r <ozaki-r%NetBSD.org@localhost>
date:      Mon Feb 15 01:11:41 2016 +0000

description:
Simplify bridge(4)

Thanks to introducing softint-based if_input, the entire bridge code now
never run in hardware interrupt context. So we can simplify the code.

- Remove spin mutexes
  - They were needed because some code of bridge could run in
    hardware interrupt context
  - We now need only an adaptive mutex for each shared object
    (a member list and a forwarding table)
- Remove pktqueue
  - bridge_input is already in softint, using another softint
    (for bridge_forward) is useless
  - Packet distribution should be down at device drivers

diffstat:

 sys/net/bridgestp.c    |   42 ++--
 sys/net/if_bridge.c    |  408 +++++++++++++++---------------------------------
 sys/net/if_bridgevar.h |   40 +----
 3 files changed, 159 insertions(+), 331 deletions(-)

diffs (truncated from 906 to 300 lines):

diff -r 6bc27342a9f0 -r 38490e70444e sys/net/bridgestp.c
--- a/sys/net/bridgestp.c       Sun Feb 14 23:47:57 2016 +0000
+++ b/sys/net/bridgestp.c       Mon Feb 15 01:11:41 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: bridgestp.c,v 1.18 2014/12/31 17:36:24 ozaki-r Exp $   */
+/*     $NetBSD: bridgestp.c,v 1.19 2016/02/15 01:11:41 ozaki-r Exp $   */
 
 /*
  * Copyright (c) 2000 Jason L. Wright (jason%thought.net@localhost)
@@ -40,7 +40,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: bridgestp.c,v 1.18 2014/12/31 17:36:24 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: bridgestp.c,v 1.19 2016/02/15 01:11:41 ozaki-r Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -221,7 +221,7 @@
        struct bstp_cbpdu bpdu;
        int s;
 
-       KASSERT(BRIDGE_INTR_LOCKED(sc));
+       KASSERT(BRIDGE_LOCKED(sc));
 
        ifp = bif->bif_ifp;
 
@@ -276,11 +276,11 @@
 
        memcpy(mtod(m, char *) + sizeof(*eh), &bpdu, sizeof(bpdu));
 
-       BRIDGE_INTR_UNLOCK(sc);
+       BRIDGE_UNLOCK(sc);
        s = splnet();
        bridge_enqueue(sc, ifp, m, 0);
        splx(s);
-       BRIDGE_INTR_LOCK(sc);
+       BRIDGE_LOCK(sc);
 }
 
 static int
@@ -367,7 +367,7 @@
        struct mbuf *m;
        int s;
 
-       KASSERT(BRIDGE_INTR_LOCKED(sc));
+       KASSERT(BRIDGE_LOCKED(sc));
 
        KASSERT(bif != NULL);
        ifp = bif->bif_ifp;
@@ -396,11 +396,11 @@
 
        memcpy(mtod(m, char *) + sizeof(*eh), &bpdu, sizeof(bpdu));
 
-       BRIDGE_INTR_UNLOCK(sc);
+       BRIDGE_UNLOCK(sc);
        s = splnet();
        bridge_enqueue(sc, ifp, m, 0);
        splx(s);
-       BRIDGE_INTR_LOCK(sc);
+       BRIDGE_LOCK(sc);
 }
 
 static void
@@ -634,9 +634,9 @@
        case BSTP_MSGTYPE_TCN:
                tu.tu_message_type = tpdu.tbu_bpdutype;
 
-               BRIDGE_INTR_LOCK(sc);
+               BRIDGE_LOCK(sc);
                bstp_received_tcn_bpdu(sc, bif, &tu);
-               BRIDGE_INTR_UNLOCK(sc);
+               BRIDGE_UNLOCK(sc);
 
                break;
        case BSTP_MSGTYPE_CFG:
@@ -675,9 +675,9 @@
                cu.cu_topology_change =
                    (cpdu.cbu_flags & BSTP_FLAG_TC) ? 1 : 0;
 
-               BRIDGE_INTR_LOCK(sc);
+               BRIDGE_LOCK(sc);
                bstp_received_config_bpdu(sc, bif, &cu);
-               BRIDGE_INTR_UNLOCK(sc);
+               BRIDGE_UNLOCK(sc);
 
                break;
        default:
@@ -826,7 +826,7 @@
 
        mif = NULL;
 
-       BRIDGE_INTR_LOCK(sc);
+       BRIDGE_LOCK(sc);
 
        LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
                if ((bif->bif_flags & IFBIF_STP) == 0)
@@ -848,7 +848,7 @@
        }
 
        if (mif == NULL) {
-               BRIDGE_INTR_UNLOCK(sc);
+               BRIDGE_UNLOCK(sc);
                bstp_stop(sc);
                return;
        }
@@ -862,7 +862,7 @@
            (((uint64_t)(uint8_t)CLLADDR(mif->bif_ifp->if_sadl)[4]) << 8) |
            (((uint64_t)(uint8_t)CLLADDR(mif->bif_ifp->if_sadl)[5]) << 0);
 
-       BRIDGE_INTR_UNLOCK(sc);
+       BRIDGE_UNLOCK(sc);
 
        sc->sc_designated_root = sc->sc_bridge_id;
        sc->sc_root_path_cost = 0;
@@ -880,7 +880,7 @@
                callout_reset(&sc->sc_bstpcallout, hz,
                    bstp_tick, sc);
 
-       BRIDGE_INTR_LOCK(sc);
+       BRIDGE_LOCK(sc);
 
        LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
                if (bif->bif_flags & IFBIF_STP)
@@ -893,7 +893,7 @@
        bstp_config_bpdu_generation(sc);
        bstp_timer_start(&sc->sc_hello_timer, 0);
 
-       BRIDGE_INTR_UNLOCK(sc);
+       BRIDGE_UNLOCK(sc);
 }
 
 void
@@ -901,14 +901,14 @@
 {
        struct bridge_iflist *bif;
 
-       BRIDGE_INTR_LOCK(sc);
+       BRIDGE_LOCK(sc);
        LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
                bstp_set_port_state(bif, BSTP_IFSTATE_DISABLED);
                bstp_timer_stop(&bif->bif_hold_timer);
                bstp_timer_stop(&bif->bif_message_age_timer);
                bstp_timer_stop(&bif->bif_forward_delay_timer);
        }
-       BRIDGE_INTR_UNLOCK(sc);
+       BRIDGE_UNLOCK(sc);
 
        callout_stop(&sc->sc_bstpcallout);
 
@@ -1065,7 +1065,7 @@
        int s;
 
        s = splnet();
-       BRIDGE_INTR_LOCK(sc);
+       BRIDGE_LOCK(sc);
 
        LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
                if ((bif->bif_flags & IFBIF_STP) == 0)
@@ -1113,7 +1113,7 @@
        if (sc->sc_if.if_flags & IFF_RUNNING)
                callout_reset(&sc->sc_bstpcallout, hz, bstp_tick, sc);
 
-       BRIDGE_INTR_UNLOCK(sc);
+       BRIDGE_UNLOCK(sc);
        splx(s);
 }
 
diff -r 6bc27342a9f0 -r 38490e70444e sys/net/if_bridge.c
--- a/sys/net/if_bridge.c       Sun Feb 14 23:47:57 2016 +0000
+++ b/sys/net/if_bridge.c       Mon Feb 15 01:11:41 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_bridge.c,v 1.107 2016/02/10 06:30:23 ozaki-r Exp $  */
+/*     $NetBSD: if_bridge.c,v 1.108 2016/02/15 01:11:41 ozaki-r Exp $  */
 
 /*
  * Copyright 2001 Wasabi Systems, Inc.
@@ -80,7 +80,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_bridge.c,v 1.107 2016/02/10 06:30:23 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_bridge.c,v 1.108 2016/02/15 01:11:41 ozaki-r Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_bridge_ipf.h"
@@ -108,7 +108,6 @@
 #include <net/if_dl.h>
 #include <net/if_types.h>
 #include <net/if_llc.h>
-#include <net/pktqueue.h>
 
 #include <net/if_ether.h>
 #include <net/if_bridgevar.h>
@@ -181,10 +180,6 @@
 #define        BRIDGE_RTABLE_PRUNE_PERIOD      (5 * 60)
 #endif
 
-#define BRIDGE_RT_INTR_LOCK(_sc)       mutex_enter((_sc)->sc_rtlist_intr_lock)
-#define BRIDGE_RT_INTR_UNLOCK(_sc)     mutex_exit((_sc)->sc_rtlist_intr_lock)
-#define BRIDGE_RT_INTR_LOCKED(_sc)     mutex_owned((_sc)->sc_rtlist_intr_lock)
-
 #define BRIDGE_RT_LOCK(_sc)    if ((_sc)->sc_rtlist_lock) \
                                        mutex_enter((_sc)->sc_rtlist_lock)
 #define BRIDGE_RT_UNLOCK(_sc)  if ((_sc)->sc_rtlist_lock) \
@@ -197,18 +192,8 @@
                                        pserialize_perform((_sc)->sc_rtlist_psz);
 
 #ifdef BRIDGE_MPSAFE
-#define BRIDGE_RT_RENTER(__s)  do { \
-                                       if (!cpu_intr_p()) \
-                                               __s = pserialize_read_enter(); \
-                                       else \
-                                               __s = splhigh(); \
-                               } while (0)
-#define BRIDGE_RT_REXIT(__s)   do { \
-                                       if (!cpu_intr_p()) \
-                                               pserialize_read_exit(__s); \
-                                       else \
-                                               splx(__s); \
-                               } while (0)
+#define BRIDGE_RT_RENTER(__s)  do { __s = pserialize_read_enter(); } while (0)
+#define BRIDGE_RT_REXIT(__s)   do { pserialize_read_exit(__s); } while (0)
 #else /* BRIDGE_MPSAFE */
 #define BRIDGE_RT_RENTER(__s)  do { __s = 0; } while (0)
 #define BRIDGE_RT_REXIT(__s)   do { (void)__s; } while (0)
@@ -227,7 +212,7 @@
 static void    bridge_start(struct ifnet *);
 
 static void    bridge_input(struct ifnet *, struct mbuf *);
-static void    bridge_forward(void *);
+static void    bridge_forward(struct bridge_softc *, struct mbuf *);
 
 static void    bridge_timer(void *);
 
@@ -297,9 +282,6 @@
 # endif /* INET6 */
 #endif /* BRIDGE_IPF */
 
-static void bridge_sysctl_fwdq_setup(struct sysctllog **clog,
-    struct bridge_softc *sc);
-
 struct bridge_control {
        int     (*bc_func)(struct bridge_softc *, void *);
        int     bc_argsize;
@@ -424,11 +406,9 @@
 
        LIST_INIT(&sc->sc_iflist);
 #ifdef BRIDGE_MPSAFE
-       sc->sc_iflist_intr_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NET);
        sc->sc_iflist_psz = pserialize_create();
        sc->sc_iflist_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_SOFTNET);
 #else
-       sc->sc_iflist_intr_lock = NULL;
        sc->sc_iflist_psz = NULL;
        sc->sc_iflist_lock = NULL;
 #endif
@@ -447,11 +427,6 @@
        ifp->if_dlt = DLT_EN10MB;
        ifp->if_hdrlen = ETHER_HDR_LEN;
 
-       sc->sc_fwd_pktq = pktq_create(IFQ_MAXLEN, bridge_forward, sc);
-       KASSERT(sc->sc_fwd_pktq != NULL);
-
-       bridge_sysctl_fwdq_setup(&ifp->if_sysctl_log, sc);
-
        if_initialize(ifp);
        if_register(ifp);
 
@@ -476,9 +451,6 @@
        struct bridge_iflist *bif;
        int s;
 
-       /* Must be called during IFF_RUNNING, i.e., before bridge_stop */
-       pktq_barrier(sc->sc_fwd_pktq);
-
        s = splnet();
 
        bridge_stop(ifp, 1);
@@ -496,16 +468,10 @@
 
        if_detach(ifp);
 
-       /* Should be called after if_detach for safe */
-       pktq_flush(sc->sc_fwd_pktq);
-       pktq_destroy(sc->sc_fwd_pktq);
-
        /* Tear down the routing table. */
        bridge_rtable_fini(sc);
 
        cv_destroy(&sc->sc_iflist_cv);
-       if (sc->sc_iflist_intr_lock)
-               mutex_obj_free(sc->sc_iflist_intr_lock);
 
        if (sc->sc_iflist_psz)
                pserialize_destroy(sc->sc_iflist_psz);
@@ -519,92 +485,6 @@
        return (0);
 }