From 6a1ece141c92669d0e1e9f9f4883c88334197686 Mon Sep 17 00:00:00 2001
From: Nick Hudson <skrll@netbsd.org>
Date: Fri, 29 Jul 2022 15:59:25 +0100
Subject: [PATCH 06/67] wm: use a workqueue to reset the interface when
 wm_watchdog determines it needs a reset.

---
 sys/dev/pci/if_wm.c | 75 ++++++++++++++++++++++++++++++++++-----------
 1 file changed, 57 insertions(+), 18 deletions(-)

diff --git a/sys/dev/pci/if_wm.c b/sys/dev/pci/if_wm.c
index 78ebb22f5c40..e123005fa2f9 100644
--- a/sys/dev/pci/if_wm.c
+++ b/sys/dev/pci/if_wm.c
@@ -705,6 +705,10 @@ struct wm_softc {
 
 	struct wm_phyop phy;
 	struct wm_nvmop nvm;
+
+	struct workqueue *sc_reset_wq;
+	struct work sc_reset_work;
+
 #ifdef WM_DEBUG
 	uint32_t sc_debug;
 #endif
@@ -820,7 +824,7 @@ static void	wm_attach(device_t, device_t, void *);
 static int	wm_detach(device_t, int);
 static bool	wm_suspend(device_t, const pmf_qual_t *);
 static bool	wm_resume(device_t, const pmf_qual_t *);
-static void	wm_watchdog(struct ifnet *);
+static bool	wm_watchdog(struct ifnet *);
 static void	wm_watchdog_txq(struct ifnet *, struct wm_txqueue *,
     uint16_t *);
 static void	wm_watchdog_txq_locked(struct ifnet *, struct wm_txqueue *,
@@ -914,6 +918,7 @@ static void	wm_nq_send_common_locked(struct ifnet *, struct wm_txqueue *,
 static void	wm_deferred_start_locked(struct wm_txqueue *);
 static void	wm_handle_queue(void *);
 static void	wm_handle_queue_work(struct work *, void *);
+static void	wm_handle_reset_work(struct work *, void *);
 /* Interrupt */
 static bool	wm_txeof(struct wm_txqueue *, u_int);
 static bool	wm_rxeof(struct wm_rxqueue *, u_int);
@@ -2218,7 +2223,18 @@ alloc_retry:
 	    WM_WORKQUEUE_FLAGS);
 	if (error) {
 		aprint_error_dev(sc->sc_dev,
-		    "unable to create workqueue\n");
+		    "unable to create TxRx workqueue\n");
+		goto out;
+	}
+
+	snprintf(wqname, sizeof(wqname), "%sReset", device_xname(sc->sc_dev));
+	error = workqueue_create(&sc->sc_reset_wq, wqname,
+	    wm_handle_reset_work, sc, WM_WORKQUEUE_PRI, IPL_NET,
+	    WM_WORKQUEUE_FLAGS);
+	if (error) {
+		workqueue_destroy(sc->sc_queue_wq);
+		aprint_error_dev(sc->sc_dev,
+		    "unable to create reset workqueue\n");
 		goto out;
 	}
 
@@ -3510,8 +3526,9 @@ wm_detach(device_t self, int flags __unused)
 	}
 	pci_intr_release(sc->sc_pc, sc->sc_intrs, sc->sc_nintrs);
 
-	/* wm_stop() ensured that the workqueue is stopped. */
+	/* wm_stop() ensured that the tx workqueue is stopped. */
 	workqueue_destroy(sc->sc_queue_wq);
+	workqueue_destroy(sc->sc_reset_wq);
 
 	for (i = 0; i < sc->sc_nqueues; i++)
 		softint_disestablish(sc->sc_queue[i].wmq_si);
@@ -3594,11 +3611,11 @@ wm_resume(device_t self, const pmf_qual_t *qual)
 }
 
 /*
- * wm_watchdog:		[ifnet interface function]
+ * wm_watchdog:
  *
- *	Watchdog timer handler.
+ *	Watchdog checker.
  */
-static void
+static bool
 wm_watchdog(struct ifnet *ifp)
 {
 	int qid;
@@ -3611,17 +3628,38 @@ wm_watchdog(struct ifnet *ifp)
 		wm_watchdog_txq(ifp, txq, &hang_queue);
 	}
 
-	/* IF any of queues hanged up, reset the interface. */
-	if (hang_queue != 0) {
-		(void)wm_init(ifp);
+	if (hang_queue == 0)
+		return true;
 
-		/*
-		 * There are still some upper layer processing which call
-		 * ifp->if_start(). e.g. ALTQ or one CPU system
-		 */
-		/* Try to get more packets going. */
-		ifp->if_start(ifp);
-	}
+	workqueue_enqueue(sc->sc_reset_wq, &sc->sc_reset_work, NULL);
+
+	return false;
+}
+
+/*
+ * Perform an interface watchdog reset.
+ */
+static void
+wm_handle_reset_work(struct work *work, void *arg)
+{
+	struct wm_softc * const sc =
+	    container_of(work, struct wm_softc, sc_reset_work);
+	struct ifnet * const ifp = &sc->sc_ethercom.ec_if;
+
+	/* Don't want ioctl operations to happen */
+	IFNET_LOCK(ifp);
+
+	/* reset the interface. */
+	wm_init(ifp);
+
+	/*
+	 * There are still some upper layer processing which call
+	 * ifp->if_start(). e.g. ALTQ or one CPU system
+	 */
+	/* Try to get more packets going. */
+	ifp->if_start(ifp);
+
+	IFNET_UNLOCK(ifp);
 }
 
 
@@ -3854,9 +3892,10 @@ wm_tick(void *arg)
 	splx(s);
 #endif
 
-	wm_watchdog(ifp);
+	bool ok = wm_watchdog(ifp);
 
-	callout_schedule(&sc->sc_tick_ch, hz);
+	if (ok)
+		callout_schedule(&sc->sc_tick_ch, hz);
 }
 
 static int
-- 
2.25.1