mac80211: track assigned vifs in chanctx

This can be useful. Provides a more straghtforward
way to iterate over interfaces bound to a given
chanctx and allows tracking chanctx usage
explicitly.

The structure is protected by local->chanctx_mtx.

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

3 files changed, 9 insertions, 0 deletions

diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index 4ed229c0966a..504526c97867 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -276,6 +276,7 @@ ieee80211_new_chanctx(struct ieee80211_local *local,
         if (!ctx)
                 return ERR_PTR(-ENOMEM);
 
+        INIT_LIST_HEAD(&ctx->assigned_vifs);
         ctx->conf.def = *chandef;
         ctx->conf.rx_chains_static = 1;
         ctx->conf.rx_chains_dynamic = 1;
@@ -420,6 +421,7 @@ static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
                 curr_ctx->refcount--;
                 drv_unassign_vif_chanctx(local, sdata, curr_ctx);
                 conf = NULL;
+                list_del(&sdata->assigned_chanctx_list);
         }
 
         if (new_ctx) {
@@ -429,6 +431,8 @@ static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
 
                 new_ctx->refcount++;
                 conf = &new_ctx->conf;
+                list_add(&sdata->assigned_chanctx_list,
+                         &new_ctx->assigned_vifs);
         }
 
 out:
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 4018ba13c028..3b3b45a21501 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -691,6 +691,8 @@ struct ieee80211_chanctx {
         struct list_head list;
         struct rcu_head rcu_head;
 
+        struct list_head assigned_vifs;
+
         enum ieee80211_chanctx_mode mode;
         int refcount;
         bool driver_present;
@@ -756,6 +758,8 @@ struct ieee80211_sub_if_data {
         bool csa_radar_required;
         struct cfg80211_chan_def csa_chandef;
 
+        struct list_head assigned_chanctx_list; /* protected by chanctx_mtx */
+
         /* context reservation -- protected with chanctx_mtx */
         struct ieee80211_chanctx *reserved_chanctx;
         struct cfg80211_chan_def reserved_chandef;
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 90b60633a27a..a562d0f489e1 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -1291,6 +1291,7 @@ static void ieee80211_setup_sdata(struct ieee80211_sub_if_data *sdata,
         INIT_WORK(&sdata->work, ieee80211_iface_work);
         INIT_WORK(&sdata->recalc_smps, ieee80211_recalc_smps_work);
         INIT_WORK(&sdata->csa_finalize_work, ieee80211_csa_finalize_work);
+        INIT_LIST_HEAD(&sdata->assigned_chanctx_list);
 
         switch (type) {
         case NL80211_IFTYPE_P2P_GO: