remove dtp_mtx which protected dtp_ref; the code is always called with KERNEL_LOCK...

discussed with and OK mpi@

diff --git a/sys/dev/dt/dt_prov_kprobe.c b/sys/dev/dt/dt_prov_kprobe.c
index f239ad1..5275b61 100644 (file)
--- a/sys/dev/dt/dt_prov_kprobe.c
+++ b/sys/dev/dt/dt_prov_kprobe.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: dt_prov_kprobe.c,v 1.1 2021/09/03 16:45:45 jasper Exp $       */
+/*     $OpenBSD: dt_prov_kprobe.c,v 1.2 2021/10/25 17:15:29 jasper Exp $       */
 
 /*
  * Copyright (c) 2020 Tom Rollet <tom.rollet@epita.fr>
@@ -243,7 +243,6 @@ dt_prov_kprobe_alloc(struct dt_probe *dtp, struct dt_softc *sc,
                return ENOMEM;
 
        /* Patch only if it's first pcb referencing this probe */
-       mtx_enter(&dtp->dtp_mtx);
        dtp->dtp_ref++;
        KASSERT(dtp->dtp_ref != 0);
 
@@ -252,7 +251,6 @@ dt_prov_kprobe_alloc(struct dt_probe *dtp, struct dt_softc *sc,
                db_write_bytes(dtp->dtp_addr, BKPT_SIZE, &patch);
                intr_restore(s);
        }
-       mtx_leave(&dtp->dtp_mtx);
 
        dp->dp_filter = dtrq->dtrq_filter;
        dp->dp_evtflags = dtrq->dtrq_evtflags & DTEVT_PROV_KPROBE;
@@ -282,7 +280,6 @@ dt_prov_kprobe_dealloc(struct dt_probe *dtp, struct dt_softc *sc,
        } else
                KASSERT(0 && "Trying to dealloc not yet implemented probe type");
 
-       mtx_enter(&dtp->dtp_mtx);
        dtp->dtp_ref--;
 
        if (dtp->dtp_ref == 0) {
@@ -291,8 +288,6 @@ dt_prov_kprobe_dealloc(struct dt_probe *dtp, struct dt_softc *sc,
                intr_restore(s);
        }
 
-       mtx_leave(&dtp->dtp_mtx);
-
        /* Deallocation of PCB is done by dt_pcb_purge when closing the dev */
        return 0;
 }
@@ -417,8 +412,6 @@ dt_prov_kprobe_patch_all_entry(void)
        for (i = 0; i < PPTMASK; ++i) {
                SLIST_FOREACH(kprobe_dtp, &dtpf_entry[i], kprobe_next) {
                        dtp = kprobe_dtp->dtp;
-
-                       mtx_enter(&dtp->dtp_mtx);
                        dtp->dtp_ref++;
 
                        if (dtp->dtp_ref == 1) {
@@ -427,8 +420,6 @@ dt_prov_kprobe_patch_all_entry(void)
                                db_write_bytes(dtp->dtp_addr, BKPT_SIZE, &patch);
                                intr_restore(s);
                        }
-
-                       mtx_leave(&dtp->dtp_mtx);
                }
        }
 }
@@ -445,8 +436,6 @@ dt_prov_kprobe_depatch_all_entry(void)
        for (i = 0; i < PPTMASK; ++i) {
                SLIST_FOREACH(kprobe_dtp, &dtpf_entry[i], kprobe_next) {
                        dtp = kprobe_dtp->dtp;
-
-                       mtx_enter(&dtp->dtp_mtx);
                        dtp->dtp_ref--;
 
                        if (dtp->dtp_ref == 0) {
@@ -455,8 +444,6 @@ dt_prov_kprobe_depatch_all_entry(void)
                                db_write_bytes(dtp->dtp_addr, SSF_SIZE, &patch);
                                intr_restore(s);
                        }
-
-                       mtx_leave(&dtp->dtp_mtx);
                }
 
        }

diff --git a/sys/dev/dt/dtvar.h b/sys/dev/dt/dtvar.h
index db47cfd..e90e44f 100644 (file)
--- a/sys/dev/dt/dtvar.h
+++ b/sys/dev/dt/dtvar.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: dtvar.h,v 1.8 2021/09/03 16:45:45 jasper Exp $ */
+/*     $OpenBSD: dtvar.h,v 1.9 2021/10/25 17:15:29 jasper Exp $ */
 
 /*
  * Copyright (c) 2019 Martin Pieuchot <mpi@openbsd.org>
@@ -215,7 +215,6 @@ struct dt_probe {
        const char              *dtp_name;      /* [I] probe name */
        uint32_t                 dtp_pbn;       /* [I] unique ID */
        volatile uint32_t        dtp_recording; /* [d] is it recording? */
-       struct mutex             dtp_mtx;
        unsigned                 dtp_ref;       /* [m] # of PCBs referencing the probe */
 
        /* Provider specific fields. */