[src/trunk]: src/sys/net Replace the list for vlan interfaces with the counter

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

details:   https://anonhg.NetBSD.org/src/rev/5d4e3e5ebbfb
branches:  trunk
changeset: 1023948:5d4e3e5ebbfb
user:      yamaguchi <yamaguchi%NetBSD.org@localhost>
date:      Tue Oct 05 04:09:49 2021 +0000

description:
Replace the list for vlan interfaces with the counter

The list had been used in vlan_ifdetach(), but it is no longer in
use as a linked list by introducing ether_ifdetach hook.

diffstat:

 sys/net/if_vlan.c |  32 ++++++++------------------------
 1 files changed, 8 insertions(+), 24 deletions(-)

diffs (104 lines):

diff -r 300779dec2a6 -r 5d4e3e5ebbfb sys/net/if_vlan.c
--- a/sys/net/if_vlan.c Mon Oct 04 21:02:39 2021 +0000
+++ b/sys/net/if_vlan.c Tue Oct 05 04:09:49 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_vlan.c,v 1.163 2021/09/30 04:13:42 yamaguchi Exp $  */
+/*     $NetBSD: if_vlan.c,v 1.164 2021/10/05 04:09:49 yamaguchi Exp $  */
 
 /*
  * Copyright (c) 2000, 2001 The NetBSD Foundation, Inc.
@@ -78,7 +78,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_vlan.c,v 1.163 2021/09/30 04:13:42 yamaguchi Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_vlan.c,v 1.164 2021/10/05 04:09:49 yamaguchi Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
@@ -160,7 +160,6 @@
        void *ifv_ifdetach_hook;
 
        LIST_HEAD(__vlan_mchead, vlan_mc_entry) ifv_mc_listhead;
-       LIST_ENTRY(ifvlan) ifv_list;
        struct pslist_entry ifv_hash;
        int ifv_flags;
        bool ifv_stopping;
@@ -212,12 +211,6 @@
 static struct ifvlan_linkmib*  vlan_lookup_tag_psref(struct ifnet *,
     uint16_t, struct psref *);
 
-static struct {
-       kmutex_t lock;
-       LIST_HEAD(vlan_ifvlist, ifvlan) list;
-} ifv_list __cacheline_aligned;
-
-
 #if !defined(VLAN_TAG_HASH_SIZE)
 #define VLAN_TAG_HASH_SIZE 32
 #endif
@@ -239,6 +232,8 @@
 /* Used to pad ethernet frames with < ETHER_MIN_LEN bytes */
 static char vlan_zero_pad_buff[ETHER_MIN_LEN];
 
+static uint32_t nvlanifs;
+
 static inline int
 vlan_safe_ifpromisc(struct ifnet *ifp, int pswitch)
 {
@@ -276,8 +271,7 @@
 static void
 vlaninit(void)
 {
-       mutex_init(&ifv_list.lock, MUTEX_DEFAULT, IPL_NONE);
-       LIST_INIT(&ifv_list.list);
+       nvlanifs = 0;
 
        mutex_init(&ifv_hash.lock, MUTEX_DEFAULT, IPL_NONE);
        vlan_psz = pserialize_create();
@@ -291,14 +285,9 @@
 static int
 vlandetach(void)
 {
-       bool is_empty;
        int error;
 
-       mutex_enter(&ifv_list.lock);
-       is_empty = LIST_EMPTY(&ifv_list.list);
-       mutex_exit(&ifv_list.lock);
-
-       if (!is_empty)
+       if (nvlanifs > 0)
                return EBUSY;
 
        error = vlan_hash_fini();
@@ -309,7 +298,6 @@
        psref_class_destroy(ifvm_psref_class);
        pserialize_destroy(vlan_psz);
        mutex_destroy(&ifv_hash.lock);
-       mutex_destroy(&ifv_list.lock);
 
        MODULE_HOOK_UNSET(if_vlan_vlan_input_hook);
        return 0;
@@ -352,9 +340,7 @@
        ifv->ifv_psz = pserialize_create();
        ifv->ifv_mib = mib;
 
-       mutex_enter(&ifv_list.lock);
-       LIST_INSERT_HEAD(&ifv_list.list, ifv, ifv_list);
-       mutex_exit(&ifv_list.lock);
+       atomic_inc_uint(&nvlanifs);
 
        if_initname(ifp, ifc->ifc_name, unit);
        ifp->if_softc = ifv;
@@ -385,9 +371,7 @@
 {
        struct ifvlan *ifv = ifp->if_softc;
 
-       mutex_enter(&ifv_list.lock);
-       LIST_REMOVE(ifv, ifv_list);
-       mutex_exit(&ifv_list.lock);
+       atomic_dec_uint(&nvlanifs);
 
        IFNET_LOCK(ifp);
        vlan_unconfig(ifp);