[src/trunk]: src/sys/net/npf npf(4): Use atomic_store_release and atomic_load...

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

details:   https://anonhg.NetBSD.org/src/rev/1e330892c5c5
branches:  trunk
changeset: 361553:1e330892c5c5
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Sun Feb 13 19:20:23 2022 +0000

description:
npf(4): Use atomic_store_release and atomic_load_consume for conn_db.

...or atomic_load_relaxed, when npf->conn_lock is held, for the sake
of C11.

No need for store-before-load implied by membar_sync.

diffstat:

 sys/net/npf/npf_conn.c |  11 +++++------
 1 files changed, 5 insertions(+), 6 deletions(-)

diffs (49 lines):

diff -r d16ca8ac9df6 -r 1e330892c5c5 sys/net/npf/npf_conn.c
--- a/sys/net/npf/npf_conn.c    Sun Feb 13 19:20:11 2022 +0000
+++ b/sys/net/npf/npf_conn.c    Sun Feb 13 19:20:23 2022 +0000
@@ -104,7 +104,7 @@
 
 #ifdef _KERNEL
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: npf_conn.c,v 1.33 2021/01/25 17:18:55 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: npf_conn.c,v 1.34 2022/02/13 19:20:23 riastradh Exp $");
 
 #include <sys/param.h>
 #include <sys/types.h>
@@ -221,8 +221,7 @@
                KASSERT(atomic_load_relaxed(&npf->conn_tracking)
                    == CONN_TRACKING_OFF);
                odb = atomic_load_relaxed(&npf->conn_db);
-               membar_sync();
-               atomic_store_relaxed(&npf->conn_db, ndb);
+               atomic_store_release(&npf->conn_db, ndb);
        }
        if (track) {
                /* After this point lookups start flying in. */
@@ -492,7 +491,7 @@
         * the connection later.
         */
        mutex_enter(&con->c_lock);
-       conn_db = atomic_load_relaxed(&npf->conn_db);
+       conn_db = atomic_load_consume(&npf->conn_db);
        if (!npf_conndb_insert(conn_db, fw, con, NPF_FLOW_FORW)) {
                error = EISCONN;
                goto err;
@@ -597,7 +596,7 @@
        }
 
        /* Remove the "backwards" key. */
-       conn_db = atomic_load_relaxed(&npf->conn_db);
+       conn_db = atomic_load_consume(&npf->conn_db);
        bk = npf_conn_getbackkey(con, con->c_alen);
        ret = npf_conndb_remove(conn_db, bk);
        KASSERT(ret == con);
@@ -762,7 +761,7 @@
 void
 npf_conn_worker(npf_t *npf)
 {
-       npf_conndb_t *conn_db = atomic_load_relaxed(&npf->conn_db);
+       npf_conndb_t *conn_db = atomic_load_consume(&npf->conn_db);
        npf_conndb_gc(npf, conn_db, false, true);
 }