mac80211: use chanctx reservation for STA CSA

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

It is now safe to call ieee80211_chswitch_done()
more than once.

Also remove the ieee80211_vif_change_channel()
because it is no longer used.

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 ea4db2f..c3fd4d2 100644 (file)
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -819,70 +819,6 @@ int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
        return ret;
 }
 
-static int __ieee80211_vif_change_channel(struct ieee80211_sub_if_data *sdata,
-                                         struct ieee80211_chanctx *ctx,
-                                         u32 *changed)
-{
-       struct ieee80211_local *local = sdata->local;
-       const struct cfg80211_chan_def *chandef = &sdata->csa_chandef;
-       u32 chanctx_changed = 0;
-
-       if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
-                                    IEEE80211_CHAN_DISABLED))
-               return -EINVAL;
-
-       if (ieee80211_chanctx_refcount(local, ctx) != 1)
-               return -EINVAL;
-
-       if (sdata->vif.bss_conf.chandef.width != chandef->width) {
-               chanctx_changed = IEEE80211_CHANCTX_CHANGE_WIDTH;
-               *changed |= BSS_CHANGED_BANDWIDTH;
-       }
-
-       sdata->vif.bss_conf.chandef = *chandef;
-       ctx->conf.def = *chandef;
-
-       chanctx_changed |= IEEE80211_CHANCTX_CHANGE_CHANNEL;
-       drv_change_chanctx(local, ctx, chanctx_changed);
-
-       ieee80211_recalc_chanctx_chantype(local, ctx);
-       ieee80211_recalc_smps_chanctx(local, ctx);
-       ieee80211_recalc_radar_chanctx(local, ctx);
-       ieee80211_recalc_chanctx_min_def(local, ctx);
-
-       return 0;
-}
-
-int ieee80211_vif_change_channel(struct ieee80211_sub_if_data *sdata,
-                                u32 *changed)
-{
-       struct ieee80211_local *local = sdata->local;
-       struct ieee80211_chanctx_conf *conf;
-       struct ieee80211_chanctx *ctx;
-       int ret;
-
-       lockdep_assert_held(&local->mtx);
-
-       /* should never be called if not performing a channel switch. */
-       if (WARN_ON(!sdata->vif.csa_active))
-               return -EINVAL;
-
-       mutex_lock(&local->chanctx_mtx);
-       conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
-                                        lockdep_is_held(&local->chanctx_mtx));
-       if (!conf) {
-               ret = -EINVAL;
-               goto out;
-       }
-
-       ctx = container_of(conf, struct ieee80211_chanctx, conf);
-
-       ret = __ieee80211_vif_change_channel(sdata, ctx, changed);
- out:
-       mutex_unlock(&local->chanctx_mtx);
-       return ret;
-}
-
 static void
 __ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
                                      bool clear)
@@ -1066,8 +1002,11 @@ ieee80211_vif_chanctx_reservation_complete(struct ieee80211_sub_if_data *sdata)
                ieee80211_queue_work(&sdata->local->hw,
                                     &sdata->csa_finalize_work);
                break;
-       case NL80211_IFTYPE_UNSPECIFIED:
        case NL80211_IFTYPE_STATION:
+               ieee80211_queue_work(&sdata->local->hw,
+                                    &sdata->u.mgd.chswitch_work);
+               break;
+       case NL80211_IFTYPE_UNSPECIFIED:
        case NL80211_IFTYPE_AP_VLAN:
        case NL80211_IFTYPE_WDS:
        case NL80211_IFTYPE_MONITOR:

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index c26955f..9e025e1 100644 (file)
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -788,7 +788,6 @@ struct ieee80211_sub_if_data {
        struct mac80211_qos_map __rcu *qos_map;
 
        struct work_struct csa_finalize_work;
-       bool csa_radar_required;
        bool csa_block_tx; /* write-protected by sdata_lock and local->mtx */
        struct cfg80211_chan_def csa_chandef;
 
@@ -1850,10 +1849,6 @@ int __must_check
 ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
                               const struct cfg80211_chan_def *chandef,
                               u32 *changed);
-/* NOTE: only use ieee80211_vif_change_channel() for channel switch */
-int __must_check
-ieee80211_vif_change_channel(struct ieee80211_sub_if_data *sdata,
-                            u32 *changed);
 void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata);
 void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata);
 void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index eccc849..931330b 100644 (file)
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -940,52 +940,70 @@ static void ieee80211_chswitch_work(struct work_struct *work)
                container_of(work, struct ieee80211_sub_if_data, u.mgd.chswitch_work);
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
-       u32 changed = 0;
        int ret;
 
        if (!ieee80211_sdata_running(sdata))
                return;
 
        sdata_lock(sdata);
+       mutex_lock(&local->mtx);
+       mutex_lock(&local->chanctx_mtx);
+
        if (!ifmgd->associated)
                goto out;
 
-       mutex_lock(&local->mtx);
-       ret = ieee80211_vif_change_channel(sdata, &changed);
-       mutex_unlock(&local->mtx);
-       if (ret) {
+       if (!sdata->vif.csa_active)
+               goto out;
+
+       /*
+        * 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 (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)
+                       goto out;
+
+               ret = ieee80211_vif_use_reserved_context(sdata);
+               if (ret) {
+                       sdata_info(sdata,
+                                  "failed to use reserved channel context, disconnecting (err=%d)\n",
+                                  ret);
+                       ieee80211_queue_work(&sdata->local->hw,
+                                            &ifmgd->csa_connection_drop_work);
+                       goto out;
+               }
+
+               goto out;
+       }
+
+       if (!cfg80211_chandef_identical(&sdata->vif.bss_conf.chandef,
+                                       &sdata->csa_chandef)) {
                sdata_info(sdata,
-                          "vif channel switch failed, disconnecting\n");
+                          "failed to finalize channel switch, disconnecting\n");
                ieee80211_queue_work(&sdata->local->hw,
                                     &ifmgd->csa_connection_drop_work);
                goto out;
        }
 
-       if (!local->use_chanctx) {
-               local->_oper_chandef = sdata->csa_chandef;
-               /* Call "hw_config" only if doing sw channel switch.
-                * Otherwise update the channel directly
-                */
-               if (!local->ops->channel_switch)
-                       ieee80211_hw_config(local, 0);
-               else
-                       local->hw.conf.chandef = local->_oper_chandef;
-       }
-
        /* XXX: shouldn't really modify cfg80211-owned data! */
        ifmgd->associated->channel = sdata->csa_chandef.chan;
 
-       ieee80211_bss_info_change_notify(sdata, changed);
-
-       mutex_lock(&local->mtx);
        sdata->vif.csa_active = false;
+
        /* XXX: wait for a beacon first? */
        if (sdata->csa_block_tx) {
                ieee80211_wake_vif_queues(local, sdata,
                                          IEEE80211_QUEUE_STOP_REASON_CSA);
                sdata->csa_block_tx = false;
        }
-       mutex_unlock(&local->mtx);
 
        ifmgd->flags &= ~IEEE80211_STA_CSA_RECEIVED;
 
@@ -993,6 +1011,8 @@ static void ieee80211_chswitch_work(struct work_struct *work)
        ieee80211_sta_reset_conn_monitor(sdata);
 
 out:
+       mutex_unlock(&local->chanctx_mtx);
+       mutex_unlock(&local->mtx);
        sdata_unlock(sdata);
 }
 
@@ -1029,6 +1049,7 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        struct cfg80211_bss *cbss = ifmgd->associated;
+       struct ieee80211_chanctx_conf *conf;
        struct ieee80211_chanctx *chanctx;
        enum ieee80211_band current_band;
        struct ieee80211_csa_ie csa_ie;
@@ -1072,7 +1093,22 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
 
        ifmgd->flags |= IEEE80211_STA_CSA_RECEIVED;
 
+       mutex_lock(&local->mtx);
        mutex_lock(&local->chanctx_mtx);
+       conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
+                                        lockdep_is_held(&local->chanctx_mtx));
+       if (!conf) {
+               sdata_info(sdata,
+                          "no channel context assigned to vif?, disconnecting\n");
+               ieee80211_queue_work(&local->hw,
+                                    &ifmgd->csa_connection_drop_work);
+               mutex_unlock(&local->chanctx_mtx);
+               mutex_unlock(&local->mtx);
+               return;
+       }
+
+       chanctx = container_of(conf, struct ieee80211_chanctx, conf);
+
        if (local->use_chanctx) {
                u32 num_chanctx = 0;
                list_for_each_entry(chanctx, &local->chanctx_list, list)
@@ -1085,32 +1121,27 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
                        ieee80211_queue_work(&local->hw,
                                             &ifmgd->csa_connection_drop_work);
                        mutex_unlock(&local->chanctx_mtx);
+                       mutex_unlock(&local->mtx);
                        return;
                }
        }
 
-       if (WARN_ON(!rcu_access_pointer(sdata->vif.chanctx_conf))) {
-               ieee80211_queue_work(&local->hw,
-                                    &ifmgd->csa_connection_drop_work);
-               mutex_unlock(&local->chanctx_mtx);
-               return;
-       }
-       chanctx = container_of(rcu_access_pointer(sdata->vif.chanctx_conf),
-                              struct ieee80211_chanctx, conf);
-       if (ieee80211_chanctx_refcount(local, chanctx) > 1) {
+       res = ieee80211_vif_reserve_chanctx(sdata, &csa_ie.chandef,
+                                           chanctx->mode, false);
+       if (res) {
                sdata_info(sdata,
-                          "channel switch with multiple interfaces on the same channel, disconnecting\n");
+                          "failed to reserve channel context for channel switch, disconnecting (err=%d)\n",
+                          res);
                ieee80211_queue_work(&local->hw,
                                     &ifmgd->csa_connection_drop_work);
                mutex_unlock(&local->chanctx_mtx);
+               mutex_unlock(&local->mtx);
                return;
        }
        mutex_unlock(&local->chanctx_mtx);
 
-       sdata->csa_chandef = csa_ie.chandef;
-
-       mutex_lock(&local->mtx);
        sdata->vif.csa_active = true;
+       sdata->csa_chandef = csa_ie.chandef;
        sdata->csa_block_tx = csa_ie.mode;
 
        if (sdata->csa_block_tx)