mac80211: use chanctx reservation for AP CSA

Channel switch finalization is now 2-step. First
step is when driver calls csa_finish(), the other
is when reservation is actually finalized (which
can be deferred for in-place reservation).

It is now safe to call ieee80211_csa_finish() more
than once.

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

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 73c9e10..927b4ea 100644 (file)
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -2792,17 +2792,35 @@ static int __ieee80211_csa_finalize(struct ieee80211_sub_if_data *sdata)
 
        sdata_assert_lock(sdata);
        lockdep_assert_held(&local->mtx);
+       lockdep_assert_held(&local->chanctx_mtx);
 
-       sdata->radar_required = sdata->csa_radar_required;
-       err = ieee80211_vif_change_channel(sdata, &changed);
-       if (err < 0)
-               return err;
+       /*
+        * using reservation isn't immediate as it may be deferred until later
+        * with multi-vif. once reservation is complete it will re-schedule the
+        * work with no reserved_chanctx so verify chandef to check if it
+        * completed successfully
+        */
 
-       if (!local->use_chanctx) {
-               local->_oper_chandef = sdata->csa_chandef;
-               ieee80211_hw_config(local, 0);
+       if (sdata->reserved_chanctx) {
+               /*
+                * with multi-vif csa driver may call ieee80211_csa_finish()
+                * many times while waiting for other interfaces to use their
+                * reservations
+                */
+               if (sdata->reserved_ready)
+                       return 0;
+
+               err = ieee80211_vif_use_reserved_context(sdata);
+               if (err)
+                       return err;
+
+               return 0;
        }
 
+       if (!cfg80211_chandef_identical(&sdata->vif.bss_conf.chandef,
+                                       &sdata->csa_chandef))
+               return -EINVAL;
+
        sdata->vif.csa_active = false;
 
        err = ieee80211_set_after_csa_beacon(sdata, &changed);
@@ -2839,6 +2857,7 @@ void ieee80211_csa_finalize_work(struct work_struct *work)
 
        sdata_lock(sdata);
        mutex_lock(&local->mtx);
+       mutex_lock(&local->chanctx_mtx);
 
        /* AP might have been stopped while waiting for the lock. */
        if (!sdata->vif.csa_active)
@@ -2850,6 +2869,7 @@ void ieee80211_csa_finalize_work(struct work_struct *work)
        ieee80211_csa_finalize(sdata);
 
 unlock:
+       mutex_unlock(&local->chanctx_mtx);
        mutex_unlock(&local->mtx);
        sdata_unlock(sdata);
 }
@@ -2995,7 +3015,7 @@ __ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev,
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_chanctx_conf *conf;
        struct ieee80211_chanctx *chanctx;
-       int err, num_chanctx, changed = 0;
+       int err, changed = 0;
 
        sdata_assert_lock(sdata);
        lockdep_assert_held(&local->mtx);
@@ -3010,37 +3030,43 @@ __ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev,
                                       &sdata->vif.bss_conf.chandef))
                return -EINVAL;
 
+       /* don't allow another channel switch if one is already active. */
+       if (sdata->vif.csa_active)
+               return -EBUSY;
+
        mutex_lock(&local->chanctx_mtx);
        conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
                                         lockdep_is_held(&local->chanctx_mtx));
        if (!conf) {
-               mutex_unlock(&local->chanctx_mtx);
-               return -EBUSY;
+               err = -EBUSY;
+               goto out;
        }
 
-       /* don't handle for multi-VIF cases */
        chanctx = container_of(conf, struct ieee80211_chanctx, conf);
-       if (ieee80211_chanctx_refcount(local, chanctx) > 1) {
-               mutex_unlock(&local->chanctx_mtx);
-               return -EBUSY;
+       if (!chanctx) {
+               err = -EBUSY;
+               goto out;
        }
-       num_chanctx = 0;
-       list_for_each_entry_rcu(chanctx, &local->chanctx_list, list)
-               num_chanctx++;
-       mutex_unlock(&local->chanctx_mtx);
 
-       if (num_chanctx > 1)
-               return -EBUSY;
+       err = ieee80211_vif_reserve_chanctx(sdata, &params->chandef,
+                                           chanctx->mode,
+                                           params->radar_required);
+       if (err)
+               goto out;
 
-       /* don't allow another channel switch if one is already active. */
-       if (sdata->vif.csa_active)
-               return -EBUSY;
+       /* if reservation is invalid then this will fail */
+       err = ieee80211_check_combinations(sdata, NULL, chanctx->mode, 0);
+       if (err) {
+               ieee80211_vif_unreserve_chanctx(sdata);
+               goto out;
+       }
 
        err = ieee80211_set_csa_beacon(sdata, params, &changed);
-       if (err)
-               return err;
+       if (err) {
+               ieee80211_vif_unreserve_chanctx(sdata);
+               goto out;
+       }
 
-       sdata->csa_radar_required = params->radar_required;
        sdata->csa_chandef = params->chandef;
        sdata->csa_block_tx = params->block_tx;
        sdata->vif.csa_active = true;
@@ -3057,7 +3083,9 @@ __ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev,
                ieee80211_csa_finalize(sdata);
        }
 
-       return 0;
+out:
+       mutex_unlock(&local->chanctx_mtx);
+       return err;
 }
 
 int ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev,

diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index 0e4302b..ea4db2f 100644 (file)
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -1056,6 +1056,30 @@ int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
        return 0;
 }
 
+static void
+ieee80211_vif_chanctx_reservation_complete(struct ieee80211_sub_if_data *sdata)
+{
+       switch (sdata->vif.type) {
+       case NL80211_IFTYPE_ADHOC:
+       case NL80211_IFTYPE_AP:
+       case NL80211_IFTYPE_MESH_POINT:
+               ieee80211_queue_work(&sdata->local->hw,
+                                    &sdata->csa_finalize_work);
+               break;
+       case NL80211_IFTYPE_UNSPECIFIED:
+       case NL80211_IFTYPE_STATION:
+       case NL80211_IFTYPE_AP_VLAN:
+       case NL80211_IFTYPE_WDS:
+       case NL80211_IFTYPE_MONITOR:
+       case NL80211_IFTYPE_P2P_CLIENT:
+       case NL80211_IFTYPE_P2P_GO:
+       case NL80211_IFTYPE_P2P_DEVICE:
+       case NUM_NL80211_IFTYPES:
+               WARN_ON(1);
+               break;
+       }
+}
+
 static int
 ieee80211_vif_use_reserved_reassign(struct ieee80211_sub_if_data *sdata)
 {
@@ -1103,7 +1127,7 @@ ieee80211_vif_use_reserved_reassign(struct ieee80211_sub_if_data *sdata)
                if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
                        ieee80211_free_chanctx(local, new_ctx);
 
-               return err;
+               goto out;
        }
 
        list_move(&sdata->assigned_chanctx_list, &new_ctx->assigned_vifs);
@@ -1123,6 +1147,8 @@ ieee80211_vif_use_reserved_reassign(struct ieee80211_sub_if_data *sdata)
        if (changed)
                ieee80211_bss_info_change_notify(sdata, changed);
 
+out:
+       ieee80211_vif_chanctx_reservation_complete(sdata);
        return err;
 }
 
@@ -1167,6 +1193,7 @@ ieee80211_vif_use_reserved_assign(struct ieee80211_sub_if_data *sdata)
        }
 
 out:
+       ieee80211_vif_chanctx_reservation_complete(sdata);
        return err;
 }
 
@@ -1480,6 +1507,8 @@ ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
                        list_move(&sdata->assigned_chanctx_list,
                                  &new_ctx->assigned_vifs);
                        sdata->reserved_chanctx = NULL;
+
+                       ieee80211_vif_chanctx_reservation_complete(sdata);
                }
 
                /*
@@ -1543,8 +1572,10 @@ err:
                        continue;
 
                list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
-                                        reserved_chanctx_list)
+                                        reserved_chanctx_list) {
                        ieee80211_vif_unreserve_chanctx(sdata);
+                       ieee80211_vif_chanctx_reservation_complete(sdata);
+               }
        }
 
        return err;