mac80211: reuse channels for channel contexts

Reuse channels with compatible channel types. Some
channel types are compatible and can be used
concurrently.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index ff3b29ec396adc5ada44393dc8814f74ec944cd9..1a8dee42e546c0f3e2e1fc67fa76a72a7caf3bcd 100644 (file)
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -167,7 +167,17 @@ bool ieee80211_set_channel_type(struct ieee80211_local *local,
                sdata->vif.bss_conf.channel_type = chantype;
 
        return true;
+}
+
+static void ieee80211_change_chantype(struct ieee80211_local *local,
+                                     struct ieee80211_chanctx *ctx,
+                                     enum nl80211_channel_type chantype)
+{
+       if (chantype == ctx->conf.channel_type)
+               return;
 
+       ctx->conf.channel_type = chantype;
+       drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_CHANNEL_TYPE);
 }
 
 static struct ieee80211_chanctx *
@@ -177,6 +187,7 @@ ieee80211_find_chanctx(struct ieee80211_local *local,
                       enum ieee80211_chanctx_mode mode)
 {
        struct ieee80211_chanctx *ctx;
+       enum nl80211_channel_type compat_type;
 
        lockdep_assert_held(&local->chanctx_mtx);
 
@@ -186,13 +197,19 @@ ieee80211_find_chanctx(struct ieee80211_local *local,
                return NULL;
 
        list_for_each_entry(ctx, &local->chanctx_list, list) {
+               compat_type = ctx->conf.channel_type;
+
                if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
                        continue;
                if (ctx->conf.channel != channel)
                        continue;
-               if (ctx->conf.channel_type != channel_type)
+               if (!ieee80211_channel_types_are_compatible(ctx->conf.channel_type,
+                                                           channel_type,
+                                                           &compat_type))
                        continue;
 
+               ieee80211_change_chantype(local, ctx, compat_type);
+
                return ctx;
        }
 
@@ -260,6 +277,43 @@ static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
        return 0;
 }
 
+static enum nl80211_channel_type
+ieee80211_calc_chantype(struct ieee80211_local *local,
+                       struct ieee80211_chanctx *ctx)
+{
+       struct ieee80211_chanctx_conf *conf = &ctx->conf;
+       struct ieee80211_sub_if_data *sdata;
+       enum nl80211_channel_type result = NL80211_CHAN_NO_HT;
+
+       lockdep_assert_held(&local->chanctx_mtx);
+
+       rcu_read_lock();
+       list_for_each_entry_rcu(sdata, &local->interfaces, list) {
+               if (!ieee80211_sdata_running(sdata))
+                       continue;
+               if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
+                       continue;
+
+               WARN_ON_ONCE(!ieee80211_channel_types_are_compatible(
+                                       sdata->vif.bss_conf.channel_type,
+                                       result, &result));
+       }
+       rcu_read_unlock();
+
+       return result;
+}
+
+static void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
+                                             struct ieee80211_chanctx *ctx)
+{
+       enum nl80211_channel_type chantype;
+
+       lockdep_assert_held(&local->chanctx_mtx);
+
+       chantype = ieee80211_calc_chantype(local, ctx);
+       ieee80211_change_chantype(local, ctx, chantype);
+}
+
 static void ieee80211_unassign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
                                           struct ieee80211_chanctx *ctx)
 {
@@ -271,6 +325,9 @@ static void ieee80211_unassign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
        rcu_assign_pointer(sdata->vif.chanctx_conf, NULL);
 
        drv_unassign_vif_chanctx(local, sdata, ctx);
+
+       if (ctx->refcount > 0)
+               ieee80211_recalc_chanctx_chantype(sdata->local, ctx);
 }
 
 static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)