[src/trunk]: src/sys/dev/pci mcx: Add if_transmit callback to enable more tha...

[jmcneill <jmcneill%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/0cbef263435c
branches:  trunk
changeset: 951544:0cbef263435c
user:      jmcneill <jmcneill%NetBSD.org@localhost>
date:      Fri Feb 05 22:23:30 2021 +0000

description:
mcx: Add if_transmit callback to enable more than one tx queue

diffstat:

 sys/dev/pci/if_mcx.c |  85 ++++++++++++++++++++++++++++++++++++++++++++++++---
 1 files changed, 79 insertions(+), 6 deletions(-)

diffs (171 lines):

diff -r ebaf1a000e84 -r 0cbef263435c sys/dev/pci/if_mcx.c
--- a/sys/dev/pci/if_mcx.c      Fri Feb 05 22:15:44 2021 +0000
+++ b/sys/dev/pci/if_mcx.c      Fri Feb 05 22:23:30 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_mcx.c,v 1.15 2021/01/30 21:26:32 jmcneill Exp $ */
+/*     $NetBSD: if_mcx.c,v 1.16 2021/02/05 22:23:30 jmcneill Exp $ */
 /*     $OpenBSD: if_mcx.c,v 1.98 2021/01/27 07:46:11 dlg Exp $ */
 
 /*
@@ -23,7 +23,7 @@
 #endif
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_mcx.c,v 1.15 2021/01/30 21:26:32 jmcneill Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_mcx.c,v 1.16 2021/02/05 22:23:30 jmcneill Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -41,6 +41,8 @@
 #include <sys/kmem.h>
 #include <sys/bus.h>
 #include <sys/interrupt.h>
+#include <sys/pcq.h>
+#include <sys/cpu.h>
 
 #include <machine/intr.h>
 
@@ -70,6 +72,8 @@
 #define        CALLOUT_FLAGS   0
 /* #endif */
 
+#define        MCX_TXQ_NUM             2048
+
 #define BUS_DMASYNC_PRERW      (BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE)
 #define BUS_DMASYNC_POSTRW     (BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE)
 
@@ -2318,6 +2322,9 @@
 
 struct mcx_tx {
        struct mcx_softc        *tx_softc;
+       kmutex_t                 tx_lock;
+       pcq_t                   *tx_pcq;
+       void                    *tx_softint;
 
        int                      tx_uar;
        int                      tx_sqn;
@@ -2624,6 +2631,8 @@
 static void    mcx_stop(struct ifnet *, int);
 static int     mcx_ioctl(struct ifnet *, u_long, void *);
 static void    mcx_start(struct ifnet *);
+static int     mcx_transmit(struct ifnet *, struct mbuf *);
+static void    mcx_deferred_transmit(void *);
 static void    mcx_watchdog(struct ifnet *);
 static void    mcx_media_add_types(struct mcx_softc *);
 static void    mcx_media_status(struct ifnet *, struct ifmediareq *);
@@ -2954,6 +2963,9 @@
        ifp->if_stop = mcx_stop;
        ifp->if_ioctl = mcx_ioctl;
        ifp->if_start = mcx_start;
+       if (sc->sc_nqueues > 1) {
+               ifp->if_transmit = mcx_transmit;
+       }
        ifp->if_watchdog = mcx_watchdog;
        ifp->if_mtu = sc->sc_hardmtu;
        ifp->if_capabilities = IFCAP_CSUM_IPv4_Rx | IFCAP_CSUM_IPv4_Tx |
@@ -3009,6 +3021,10 @@
                callout_setfunc(&rx->rx_refill, mcx_refill, rx);
 
                tx->tx_softc = sc;
+               mutex_init(&tx->tx_lock, MUTEX_DEFAULT, IPL_NET);
+               tx->tx_pcq = pcq_create(MCX_TXQ_NUM, KM_SLEEP);
+               tx->tx_softint = softint_establish(SOFTINT_NET|SOFTINT_MPSAFE,
+                   mcx_deferred_transmit, tx);
 
                snprintf(intrxname, sizeof(intrxname), "%s queue %d",
                    DEVNAME(sc), i);
@@ -7763,11 +7779,9 @@
 }
 
 static void
-mcx_start(struct ifnet *ifp)
+mcx_send_common_locked(struct ifnet *ifp, struct mcx_tx *tx, bool is_transmit)
 {
        struct mcx_softc *sc = ifp->if_softc;
-       /* mcx_start() always uses TX ring[0] */
-       struct mcx_tx *tx = &sc->sc_queues[0].q_tx;
        struct mcx_sq_entry *sq, *sqe;
        struct mcx_sq_entry_seg *sqs;
        struct mcx_slot *ms;
@@ -7779,6 +7793,11 @@
        size_t bf_base;
        int i, seg, nseg;
 
+       KASSERT(mutex_owned(&tx->tx_lock));
+
+       if ((ifp->if_flags & IFF_RUNNING) == 0)
+               return;
+
        bf_base = (tx->tx_uar * MCX_PAGE_SIZE) + MCX_UAR_BF;
 
        idx = tx->tx_prod % (1 << MCX_LOG_SQ_SIZE);
@@ -7798,7 +7817,11 @@
                        break;
                }
 
-               IFQ_DEQUEUE(&ifp->if_snd, m);
+               if (is_transmit) {
+                       m = pcq_get(tx->tx_pcq);
+               } else {
+                       IFQ_DEQUEUE(&ifp->if_snd, m);
+               }
                if (m == NULL) {
                        break;
                }
@@ -7917,6 +7940,56 @@
 }
 
 static void
+mcx_start(struct ifnet *ifp)
+{
+       struct mcx_softc *sc = ifp->if_softc;
+       /* mcx_start() always uses TX ring[0] */
+       struct mcx_tx *tx = &sc->sc_queues[0].q_tx;
+
+       mutex_enter(&tx->tx_lock);
+       if (!ISSET(ifp->if_flags, IFF_OACTIVE)) {
+               mcx_send_common_locked(ifp, tx, false);
+       }
+       mutex_exit(&tx->tx_lock);
+}
+
+static int
+mcx_transmit(struct ifnet *ifp, struct mbuf *m)
+{
+       struct mcx_softc *sc = ifp->if_softc;
+       struct mcx_tx *tx;
+
+       tx = &sc->sc_queues[cpu_index(curcpu()) % sc->sc_nqueues].q_tx;
+       if (__predict_false(!pcq_put(tx->tx_pcq, m))) {
+               m_freem(m);
+               return ENOBUFS;
+       }
+
+       if (mutex_tryenter(&tx->tx_lock)) {
+               mcx_send_common_locked(ifp, tx, true);
+               mutex_exit(&tx->tx_lock);
+       } else {
+               softint_schedule(tx->tx_softint);
+       }
+
+       return 0;
+}
+
+static void
+mcx_deferred_transmit(void *arg)
+{
+       struct mcx_tx *tx = arg;
+       struct mcx_softc *sc = tx->tx_softc;
+       struct ifnet *ifp = &sc->sc_ec.ec_if;
+
+       mutex_enter(&tx->tx_lock);
+       if (pcq_peek(tx->tx_pcq) != NULL) {
+               mcx_send_common_locked(ifp, tx, true);
+       }
+       mutex_exit(&tx->tx_lock);
+}
+
+static void
 mcx_watchdog(struct ifnet *ifp)
 {
 }