Use atomic load and store functions to access refcnt and wait

variables.  Although not necessary everywhere, using atomic functions
exclusively for variables marked as atomic is clearer.
OK mvs@ visa@

diff --git a/sys/dev/pci/if_iwm.c b/sys/dev/pci/if_iwm.c
index 26d48bf..f813c07 100644 (file)
--- a/sys/dev/pci/if_iwm.c
+++ b/sys/dev/pci/if_iwm.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: if_iwm.c,v 1.391 2022/02/08 14:24:36 stsp Exp $       */
+/*     $OpenBSD: if_iwm.c,v 1.392 2022/03/10 15:21:08 bluhm Exp $      */
 
 /*
  * Copyright (c) 2014, 2016 genua gmbh <info@genua.de>
@@ -9975,7 +9975,7 @@ iwm_init(struct ifnet *ifp)
 
        generation = ++sc->sc_generation;
 
-       KASSERT(sc->task_refs.refs == 0);
+       KASSERT(atomic_load_int(&sc->task_refs.r_refs) == 0);
        refcnt_init(&sc->task_refs);
 
        err = iwm_preinit(sc);
@@ -10116,7 +10116,7 @@ iwm_stop(struct ifnet *ifp)
        iwm_del_task(sc, systq, &sc->mac_ctxt_task);
        iwm_del_task(sc, systq, &sc->phy_ctxt_task);
        iwm_del_task(sc, systq, &sc->bgscan_done_task);
-       KASSERT(sc->task_refs.refs >= 1);
+       KASSERT(atomic_load_int(&sc->task_refs.r_refs) >= 1);
        refcnt_finalize(&sc->task_refs, "iwmstop");
 
        iwm_stop_device(sc);

diff --git a/sys/dev/pci/if_iwx.c b/sys/dev/pci/if_iwx.c
index 57bdcce..9ea26c4 100644 (file)
--- a/sys/dev/pci/if_iwx.c
+++ b/sys/dev/pci/if_iwx.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: if_iwx.c,v 1.134 2022/01/21 15:51:02 stsp Exp $       */
+/*     $OpenBSD: if_iwx.c,v 1.135 2022/03/10 15:21:08 bluhm Exp $      */
 
 /*
  * Copyright (c) 2014, 2016 genua gmbh <info@genua.de>
@@ -8017,7 +8017,7 @@ iwx_init(struct ifnet *ifp)
        if (sc->sc_nvm.sku_cap_11n_enable)
                iwx_setup_ht_rates(sc);
 
-       KASSERT(sc->task_refs.refs == 0);
+       KASSERT(atomic_load_int(&sc->task_refs.r_refs) == 0);
        refcnt_init(&sc->task_refs);
        ifq_clr_oactive(&ifp->if_snd);
        ifp->if_flags |= IFF_RUNNING;
@@ -8139,7 +8139,7 @@ iwx_stop(struct ifnet *ifp)
        iwx_del_task(sc, systq, &sc->mac_ctxt_task);
        iwx_del_task(sc, systq, &sc->phy_ctxt_task);
        iwx_del_task(sc, systq, &sc->bgscan_done_task);
-       KASSERT(sc->task_refs.refs >= 1);
+       KASSERT(atomic_load_int(&sc->task_refs.r_refs) >= 1);
        refcnt_finalize(&sc->task_refs, "iwxstop");
 
        iwx_stop_device(sc);

diff --git a/sys/kern/kern_synch.c b/sys/kern/kern_synch.c
index d888cb2..27e3650 100644 (file)
--- a/sys/kern/kern_synch.c
+++ b/sys/kern/kern_synch.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: kern_synch.c,v 1.182 2022/02/19 23:56:18 deraadt Exp $        */
+/*     $OpenBSD: kern_synch.c,v 1.183 2022/03/10 15:21:08 bluhm Exp $  */
 /*     $NetBSD: kern_synch.c,v 1.37 1996/04/22 01:38:37 christos Exp $ */
 
 /*
@@ -804,7 +804,7 @@ sys___thrwakeup(struct proc *p, void *v, register_t *retval)
 void
 refcnt_init(struct refcnt *r)
 {
-       r->refs = 1;
+       atomic_store_int(&r->r_refs, 1);
 }
 
 void
@@ -813,10 +813,10 @@ refcnt_take(struct refcnt *r)
 #ifdef DIAGNOSTIC
        u_int refcnt;
 
-       refcnt = atomic_inc_int_nv(&r->refs);
+       refcnt = atomic_inc_int_nv(&r->r_refs);
        KASSERT(refcnt != 0);
 #else
-       atomic_inc_int(&r->refs);
+       atomic_inc_int(&r->r_refs);
 #endif
 }
 
@@ -825,7 +825,7 @@ refcnt_rele(struct refcnt *r)
 {
        u_int refcnt;
 
-       refcnt = atomic_dec_int_nv(&r->refs);
+       refcnt = atomic_dec_int_nv(&r->r_refs);
        KASSERT(refcnt != ~0);
 
        return (refcnt == 0);
@@ -844,10 +844,10 @@ refcnt_finalize(struct refcnt *r, const char *wmesg)
        struct sleep_state sls;
        u_int refcnt;
 
-       refcnt = atomic_dec_int_nv(&r->refs);
+       refcnt = atomic_dec_int_nv(&r->r_refs);
        while (refcnt) {
                sleep_setup(&sls, r, PWAIT, wmesg, 0);
-               refcnt = r->refs;
+               refcnt = atomic_load_int(&r->r_refs);
                sleep_finish(&sls, refcnt);
        }
 }
@@ -855,13 +855,13 @@ refcnt_finalize(struct refcnt *r, const char *wmesg)
 void
 cond_init(struct cond *c)
 {
-       c->c_wait = 1;
+       atomic_store_int(&c->c_wait, 1);
 }
 
 void
 cond_signal(struct cond *c)
 {
-       c->c_wait = 0;
+       atomic_store_int(&c->c_wait, 0);
 
        wakeup_one(c);
 }
@@ -870,12 +870,12 @@ void
 cond_wait(struct cond *c, const char *wmesg)
 {
        struct sleep_state sls;
-       int wait;
+       unsigned int wait;
 
-       wait = c->c_wait;
+       wait = atomic_load_int(&c->c_wait);
        while (wait) {
                sleep_setup(&sls, c, PWAIT, wmesg, 0);
-               wait = c->c_wait;
+               wait = atomic_load_int(&c->c_wait);
                sleep_finish(&sls, wait);
        }
 }

diff --git a/sys/netinet/ip_ipsp.c b/sys/netinet/ip_ipsp.c
index 7b1b045..a24885c 100644 (file)
--- a/sys/netinet/ip_ipsp.c
+++ b/sys/netinet/ip_ipsp.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: ip_ipsp.c,v 1.268 2022/01/04 06:32:39 yasuoka Exp $   */
+/*     $OpenBSD: ip_ipsp.c,v 1.269 2022/03/10 15:21:08 bluhm Exp $     */
 /*
  * The authors of this code are John Ioannidis (ji@tla.org),
  * Angelos D. Keromytis (kermit@csd.uch.gr),
@@ -565,7 +565,7 @@ tdb_printit(void *addr, int full, int (*pr)(const char *, ...))
                DUMP(inext, "%p");
                DUMP(onext, "%p");
                DUMP(xform, "%p");
-               pr("%18s: %d\n", "refcnt", tdb->tdb_refcnt.refs);
+               pr("%18s: %d\n", "refcnt", tdb->tdb_refcnt.r_refs);
                DUMP(encalgxform, "%p");
                DUMP(authalgxform, "%p");
                DUMP(compalgxform, "%p");
@@ -625,7 +625,7 @@ tdb_printit(void *addr, int full, int (*pr)(const char *, ...))
                pr(" %s", ipsp_address(&tdb->tdb_src, buf, sizeof(buf)));
                pr("->%s", ipsp_address(&tdb->tdb_dst, buf, sizeof(buf)));
                pr(":%d", tdb->tdb_sproto);
-               pr(" #%d", tdb->tdb_refcnt.refs);
+               pr(" #%d", tdb->tdb_refcnt.r_refs);
                pr(" %08x\n", tdb->tdb_flags);
        }
 }

diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index 51e0ea8..241fc9e 100644 (file)
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: proc.h,v 1.328 2022/02/25 18:05:49 rob Exp $  */
+/*     $OpenBSD: proc.h,v 1.329 2022/03/10 15:21:08 bluhm Exp $        */
 /*     $NetBSD: proc.h,v 1.44 1996/04/22 01:23:21 christos Exp $       */
 
 /*-
@@ -589,10 +589,10 @@ struct sleep_state {
 };
 
 struct cond {
-       int     c_wait;
+       unsigned int    c_wait;         /* [a] initialized and waiting */
 };
 
-#define COND_INITIALIZER()             { 1 }
+#define COND_INITIALIZER()             { .c_wait = 1 }
 
 #if defined(MULTIPROCESSOR)
 void   proc_trampoline_mp(void);       /* XXX */

diff --git a/sys/sys/refcnt.h b/sys/sys/refcnt.h
index 85e84cf..2642334 100644 (file)
--- a/sys/sys/refcnt.h
+++ b/sys/sys/refcnt.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: refcnt.h,v 1.4 2016/06/07 07:53:33 mpi Exp $ */
+/*     $OpenBSD: refcnt.h,v 1.5 2022/03/10 15:21:08 bluhm Exp $ */
 
 /*
  * Copyright (c) 2015 David Gwynne <dlg@openbsd.org>
@@ -19,11 +19,16 @@
 #ifndef _SYS_REFCNT_H_
 #define _SYS_REFCNT_H_
 
+/*
+ * Locks used to protect struct members in this file:
+ *     a       atomic operations
+ */
+
 struct refcnt {
-       unsigned int refs;
+       unsigned int    r_refs;         /* [a] reference counter */
 };
 
-#define REFCNT_INITIALIZER()   { .refs = 1 }
+#define REFCNT_INITIALIZER()           { .r_refs = 1 }
 
 #ifdef _KERNEL