Protect ixl(4) admin queue with mutex(9).

with tweaks from bluhm

tested by bluhm

ok bluhm@

diff --git a/sys/dev/pci/if_ixl.c b/sys/dev/pci/if_ixl.c
index 3aa9c22..5f42dd5 100644 (file)
--- a/sys/dev/pci/if_ixl.c
+++ b/sys/dev/pci/if_ixl.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: if_ixl.c,v 1.87 2023/02/06 20:27:45 jan Exp $ */
+/*     $OpenBSD: if_ixl.c,v 1.88 2023/07/19 20:22:05 jan Exp $ */
 
 /*
  * Copyright (c) 2013-2015, Intel Corporation
@@ -1274,6 +1274,7 @@ struct ixl_softc {
        unsigned int             sc_atq_prod;
        unsigned int             sc_atq_cons;
 
+       struct mutex             sc_atq_mtx;
        struct ixl_dmamem        sc_arq;
        struct task              sc_arq_task;
        struct ixl_aq_bufs       sc_arq_idle;
@@ -1723,6 +1724,8 @@ ixl_attach(struct device *parent, struct device *self, void *aux)
 
        /* initialise the adminq */
 
+       mtx_init(&sc->sc_atq_mtx, IPL_NET);
+
        if (ixl_dmamem_alloc(sc, &sc->sc_atq,
            sizeof(struct ixl_aq_desc) * IXL_AQ_NUM, IXL_AQ_ALIGN) != 0) {
                printf("\n" "%s: unable to allocate atq\n", DEVNAME(sc));
@@ -3599,7 +3602,7 @@ ixl_atq_post(struct ixl_softc *sc, struct ixl_atq *iatq)
        struct ixl_aq_desc *atq, *slot;
        unsigned int prod;
 
-       /* assert locked */
+       mtx_enter(&sc->sc_atq_mtx);
 
        atq = IXL_DMA_KVA(&sc->sc_atq);
        prod = sc->sc_atq_prod;
@@ -3618,6 +3621,8 @@ ixl_atq_post(struct ixl_softc *sc, struct ixl_atq *iatq)
        prod &= IXL_AQ_MASK;
        sc->sc_atq_prod = prod;
        ixl_wr(sc, sc->sc_aq_regs->atq_tail, prod);
+
+       mtx_leave(&sc->sc_atq_mtx);
 }
 
 static void
@@ -3628,11 +3633,15 @@ ixl_atq_done(struct ixl_softc *sc)
        unsigned int cons;
        unsigned int prod;
 
+       mtx_enter(&sc->sc_atq_mtx);
+
        prod = sc->sc_atq_prod;
        cons = sc->sc_atq_cons;
 
-       if (prod == cons)
+       if (prod == cons) {
+               mtx_leave(&sc->sc_atq_mtx);
                return;
+       }
 
        atq = IXL_DMA_KVA(&sc->sc_atq);
 
@@ -3645,6 +3654,7 @@ ixl_atq_done(struct ixl_softc *sc)
                if (!ISSET(slot->iaq_flags, htole16(IXL_AQ_DD)))
                        break;
 
+               KASSERT(slot->iaq_cookie != 0);
                iatq = (struct ixl_atq *)slot->iaq_cookie;
                iatq->iatq_desc = *slot;
 
@@ -3661,6 +3671,8 @@ ixl_atq_done(struct ixl_softc *sc)
            BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
 
        sc->sc_atq_cons = cons;
+
+       mtx_leave(&sc->sc_atq_mtx);
 }
 
 static void
@@ -3691,6 +3703,8 @@ ixl_atq_poll(struct ixl_softc *sc, struct ixl_aq_desc *iaq, unsigned int tm)
        unsigned int prod;
        unsigned int t = 0;
 
+       mtx_enter(&sc->sc_atq_mtx);
+
        atq = IXL_DMA_KVA(&sc->sc_atq);
        prod = sc->sc_atq_prod;
        slot = atq + prod;
@@ -3712,8 +3726,10 @@ ixl_atq_poll(struct ixl_softc *sc, struct ixl_aq_desc *iaq, unsigned int tm)
        while (ixl_rd(sc, sc->sc_aq_regs->atq_head) != prod) {
                delaymsec(1);
 
-               if (t++ > tm)
+               if (t++ > tm) {
+                       mtx_leave(&sc->sc_atq_mtx);
                        return (ETIMEDOUT);
+               }
        }
 
        bus_dmamap_sync(sc->sc_dmat, IXL_DMA_MAP(&sc->sc_atq),
@@ -3724,6 +3740,7 @@ ixl_atq_poll(struct ixl_softc *sc, struct ixl_aq_desc *iaq, unsigned int tm)
 
        sc->sc_atq_cons = prod;
 
+       mtx_leave(&sc->sc_atq_mtx);
        return (0);
 }