PERFORCE change 65684 for review

[Sam Leffler]

http://perforce.freebsd.org/chv.cgi?CH=65684

Change 65684 by sam at sam_ebb on 2004/11/23 03:48:38

	pack allocated vap identifiers

Affected files ...

.. //depot/projects/wifi/sys/net80211/ieee80211.c#10 edit

Differences ...

==== //depot/projects/wifi/sys/net80211/ieee80211.c#10 (text+ko) ====

@@ -65,10 +65,44 @@
 SLIST_HEAD(ieee80211_list, ieee80211com);
 static struct ieee80211_list ieee80211_list =
 	SLIST_HEAD_INITIALIZER(ieee80211_list);
-static int ieee80211_vap = 0;			/* next avail vap number */
+static u_int8_t ieee80211_vapmap[32];		/* enough for 256 */
 static struct mtx ieee80211_vap_mtx;
 MTX_SYSINIT(ieee80211, &ieee80211_vap_mtx, "net80211 instances", MTX_DEF);
 
+static void
+ieee80211_add_vap(struct ieee80211com *ic)
+{
+#define	N(a)	(sizeof(a)/sizeof(a[0]))
+	int i;
+	u_int8_t b;
+
+	mtx_lock(&ieee80211_vap_mtx);
+	ic->ic_vap = 0;
+	for (i = 0; i < N(ieee80211_vapmap) && ieee80211_vapmap[i] == 0xff; i++)
+		ic->ic_vap += NBBY;
+	if (i == N(ieee80211_vapmap))
+		panic("vap table full");
+	for (b = ieee80211_vapmap[i]; b & 1; b >>= 1)
+		ic->ic_vap++;
+	setbit(ieee80211_vapmap, ic->ic_vap);
+	SLIST_INSERT_HEAD(&ieee80211_list, ic, ic_next);
+	mtx_unlock(&ieee80211_vap_mtx);
+#undef N
+}
+
+static void
+ieee80211_remove_vap(struct ieee80211com *ic)
+{
+	mtx_lock(&ieee80211_vap_mtx);
+	SLIST_REMOVE(&ieee80211_list, ic, ieee80211com, ic_next);
+	KASSERT(ic->ic_vap < sizeof(ieee80211_vapmap)*NBBY,
+		("invalid vap id %d", ic->ic_vap));
+	KASSERT(isset(ieee80211_vapmap, ic->ic_vap),
+		("vap id %d not allocated", ic->ic_vap));
+	clrbit(ieee80211_vapmap, ic->ic_vap);
+	mtx_unlock(&ieee80211_vap_mtx);
+}
+
 void
 ieee80211_ifattach(struct ieee80211com *ic)
 {
@@ -135,10 +169,7 @@
 	ieee80211_node_attach(ic);
 	ieee80211_proto_attach(ic);
 
-	mtx_lock(&ieee80211_vap_mtx);
-	ic->ic_vap = ieee80211_vap++;		/* XXX use bitmap */
-	SLIST_INSERT_HEAD(&ieee80211_list, ic, ic_next);
-	mtx_unlock(&ieee80211_vap_mtx);
+	ieee80211_add_vap(ic);
 
 	ieee80211_sysctl_attach(ic);		/* NB: requires ic_vap */
 }
@@ -148,9 +179,7 @@
 {
 	struct ifnet *ifp = ic->ic_ifp;
 
-	mtx_lock(&ieee80211_vap_mtx);
-	SLIST_REMOVE(&ieee80211_list, ic, ieee80211com, ic_next);
-	mtx_unlock(&ieee80211_vap_mtx);
+	ieee80211_remove_vap(ic);
 
 	ieee80211_sysctl_detach(ic);
 	ieee80211_proto_detach(ic);