iwlwifi: mvm: Protect mvm->csa_vif with RCU

Currently mvm->csa_vif is protected with mvm mutex. The RCU protection
is required for "iwlwifi: mvm: Reflect GO channel switch in NoA" patch.

Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

diff --git a/drivers/net/wireless/iwlwifi/mvm/mac-ctxt.c b/drivers/net/wireless/iwlwifi/mvm/mac-ctxt.c
index 6d09472..19bd696 100644 (file)
--- a/drivers/net/wireless/iwlwifi/mvm/mac-ctxt.c
+++ b/drivers/net/wireless/iwlwifi/mvm/mac-ctxt.c
@@ -1206,6 +1206,7 @@ int iwl_mvm_rx_beacon_notif(struct iwl_mvm *mvm,
 {
        struct iwl_rx_packet *pkt = rxb_addr(rxb);
        struct iwl_mvm_tx_resp *beacon_notify_hdr;
+       struct ieee80211_vif *csa_vif;
        u64 tsf;
 
        lockdep_assert_held(&mvm->mutex);
@@ -1231,13 +1232,15 @@ int iwl_mvm_rx_beacon_notif(struct iwl_mvm *mvm,
                     mvm->ap_last_beacon_gp2,
                     le32_to_cpu(beacon_notify_hdr->initial_rate));
 
-       if (unlikely(mvm->csa_vif && mvm->csa_vif->csa_active)) {
-               if (!ieee80211_csa_is_complete(mvm->csa_vif)) {
-                       ieee80211_csa_update_counter(mvm->csa_vif);
-                       iwl_mvm_mac_ctxt_beacon_changed(mvm, mvm->csa_vif);
+       csa_vif = rcu_dereference_protected(mvm->csa_vif,
+                                           lockdep_is_held(&mvm->mutex));
+       if (unlikely(csa_vif && csa_vif->csa_active)) {
+               if (!ieee80211_csa_is_complete(csa_vif)) {
+                       ieee80211_csa_update_counter(csa_vif);
+                       iwl_mvm_mac_ctxt_beacon_changed(mvm, csa_vif);
                } else {
-                       ieee80211_csa_finish(mvm->csa_vif);
-                       mvm->csa_vif = NULL;
+                       ieee80211_csa_finish(csa_vif);
+                       RCU_INIT_POINTER(mvm->csa_vif, NULL);
                }
        }
 

diff --git a/drivers/net/wireless/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/iwlwifi/mvm/mac80211.c
index 78a78c0..984a1e7 100644 (file)
--- a/drivers/net/wireless/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/iwlwifi/mvm/mac80211.c
@@ -1607,6 +1607,10 @@ static void iwl_mvm_stop_ap_ibss(struct ieee80211_hw *hw,
 
        mutex_lock(&mvm->mutex);
 
+       /* Handle AP stop while in CSA */
+       if (rcu_access_pointer(mvm->csa_vif) == vif)
+               RCU_INIT_POINTER(mvm->csa_vif, NULL);
+
        mvmvif->ap_ibss_active = false;
        mvm->ap_last_beacon_gp2 = 0;
 
@@ -2664,15 +2668,19 @@ static void iwl_mvm_channel_switch_beacon(struct ieee80211_hw *hw,
                                          struct cfg80211_chan_def *chandef)
 {
        struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
+       struct ieee80211_vif *csa_vif;
 
        mutex_lock(&mvm->mutex);
-       if (WARN(mvm->csa_vif && mvm->csa_vif->csa_active,
+
+       csa_vif = rcu_dereference_protected(mvm->csa_vif,
+                                           lockdep_is_held(&mvm->mutex));
+       if (WARN(csa_vif && csa_vif->csa_active,
                 "Another CSA is already in progress"))
                goto out_unlock;
 
        IWL_DEBUG_MAC80211(mvm, "CSA started to freq %d\n",
                           chandef->center_freq1);
-       mvm->csa_vif = vif;
+       rcu_assign_pointer(mvm->csa_vif, vif);
 
 out_unlock:
        mutex_unlock(&mvm->mutex);

diff --git a/drivers/net/wireless/iwlwifi/mvm/mvm.h b/drivers/net/wireless/iwlwifi/mvm/mvm.h
index fa8fcbc..5bb42af 100644 (file)
--- a/drivers/net/wireless/iwlwifi/mvm/mvm.h
+++ b/drivers/net/wireless/iwlwifi/mvm/mvm.h
@@ -658,7 +658,7 @@ struct iwl_mvm {
        /* Indicate if device power save is allowed */
        bool ps_disabled;
 
-       struct ieee80211_vif *csa_vif;
+       struct ieee80211_vif __rcu *csa_vif;
 
        /* system time of last beacon (for AP/GO interface) */
        u32 ap_last_beacon_gp2;