iwlwifi: mvm: disallow new TDLS stations when appropriate

HW/FW constraints dictate that TDLS should only be used when a single
phy ctx is active. We also support at most 4 TDLS peers. We don't
support TDLS on a P2P vif.

Unify and move a phy-ctx counting implementation from the power-mgmt code
in order to simplify implementation.

Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

5 files changed, 60 insertions, 21 deletions

diff --git a/drivers/net/wireless/iwlwifi/mvm/fw-api.h b/drivers/net/wireless/iwlwifi/mvm/fw-api.h
index 99329edcd99f..b8e4e78d601b 100644
--- a/drivers/net/wireless/iwlwifi/mvm/fw-api.h
+++ b/drivers/net/wireless/iwlwifi/mvm/fw-api.h
@@ -86,6 +86,8 @@ enum {
 
 #define IWL_MVM_STATION_COUNT   16
 
+#define IWL_MVM_TDLS_STA_COUNT  4
+
 /* commands */
 enum {
         MVM_ALIVE = 0x1,
diff --git a/drivers/net/wireless/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/iwlwifi/mvm/mac80211.c
index 5ed6fb32087c..57945fe06216 100644
--- a/drivers/net/wireless/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/iwlwifi/mvm/mac80211.c
@@ -1843,6 +1843,26 @@ static void iwl_mvm_sta_pre_rcu_remove(struct ieee80211_hw *hw,
         mutex_unlock(&mvm->mutex);
 }
 
+static int iwl_mvm_tdls_sta_count(struct iwl_mvm *mvm)
+{
+        struct ieee80211_sta *sta;
+        int count = 0;
+        int i;
+
+        lockdep_assert_held(&mvm->mutex);
+
+        for (i = 0; i < IWL_MVM_STATION_COUNT; i++) {
+                sta = rcu_dereference_protected(mvm->fw_id_to_mac_id[i],
+                                                lockdep_is_held(&mvm->mutex));
+                if (!sta || IS_ERR(sta) || !sta->tdls)
+                        continue;
+
+                count++;
+        }
+
+        return count;
+}
+
 static int iwl_mvm_mac_sta_state(struct ieee80211_hw *hw,
                                  struct ieee80211_vif *vif,
                                  struct ieee80211_sta *sta,
@@ -1881,6 +1901,16 @@ static int iwl_mvm_mac_sta_state(struct ieee80211_hw *hw,
                         ret = -EINVAL;
                         goto out_unlock;
                 }
+
+                if (sta->tdls &&
+                    (vif->p2p ||
+                     iwl_mvm_tdls_sta_count(mvm) == IWL_MVM_TDLS_STA_COUNT ||
+                     iwl_mvm_phy_ctx_count(mvm) > 1)) {
+                        IWL_DEBUG_MAC80211(mvm, "refusing TDLS sta\n");
+                        ret = -EBUSY;
+                        goto out_unlock;
+                }
+
                 ret = iwl_mvm_add_sta(mvm, vif, sta);
         } else if (old_state == IEEE80211_STA_NONE &&
                    new_state == IEEE80211_STA_AUTH) {
diff --git a/drivers/net/wireless/iwlwifi/mvm/mvm.h b/drivers/net/wireless/iwlwifi/mvm/mvm.h
index 7b308c4834f6..c75b958736bc 100644
--- a/drivers/net/wireless/iwlwifi/mvm/mvm.h
+++ b/drivers/net/wireless/iwlwifi/mvm/mvm.h
@@ -838,6 +838,7 @@ void iwl_mvm_phy_ctxt_ref(struct iwl_mvm *mvm,
                           struct iwl_mvm_phy_ctxt *ctxt);
 void iwl_mvm_phy_ctxt_unref(struct iwl_mvm *mvm,
                             struct iwl_mvm_phy_ctxt *ctxt);
+int iwl_mvm_phy_ctx_count(struct iwl_mvm *mvm);
 
 /* MAC (virtual interface) programming */
 int iwl_mvm_mac_ctxt_init(struct iwl_mvm *mvm, struct ieee80211_vif *vif);
diff --git a/drivers/net/wireless/iwlwifi/mvm/phy-ctxt.c b/drivers/net/wireless/iwlwifi/mvm/phy-ctxt.c
index 539f3a942d43..6cc243f7cf60 100644
--- a/drivers/net/wireless/iwlwifi/mvm/phy-ctxt.c
+++ b/drivers/net/wireless/iwlwifi/mvm/phy-ctxt.c
@@ -261,3 +261,29 @@ void iwl_mvm_phy_ctxt_unref(struct iwl_mvm *mvm, struct iwl_mvm_phy_ctxt *ctxt)
 
         ctxt->ref--;
 }
+
+static void iwl_mvm_binding_iterator(void *_data, u8 *mac,
+                                     struct ieee80211_vif *vif)
+{
+        unsigned long *data = _data;
+        struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
+
+        if (!mvmvif->phy_ctxt)
+                return;
+
+        if (vif->type == NL80211_IFTYPE_STATION ||
+            vif->type == NL80211_IFTYPE_AP)
+                __set_bit(mvmvif->phy_ctxt->id, data);
+}
+
+int iwl_mvm_phy_ctx_count(struct iwl_mvm *mvm)
+{
+        unsigned long phy_ctxt_counter = 0;
+
+        ieee80211_iterate_active_interfaces_atomic(mvm->hw,
+                                                   IEEE80211_IFACE_ITER_NORMAL,
+                                                   iwl_mvm_binding_iterator,
+                                                   &phy_ctxt_counter);
+
+        return hweight8(phy_ctxt_counter);
+}
diff --git a/drivers/net/wireless/iwlwifi/mvm/power.c b/drivers/net/wireless/iwlwifi/mvm/power.c
index c182a8baf685..3b582dd6d77f 100644
--- a/drivers/net/wireless/iwlwifi/mvm/power.c
+++ b/drivers/net/wireless/iwlwifi/mvm/power.c
@@ -246,30 +246,10 @@ static void iwl_mvm_power_configure_uapsd(struct iwl_mvm *mvm,
                 IWL_MVM_PS_HEAVY_RX_THLD_PERCENT;
 }
 
-static void iwl_mvm_binding_iterator(void *_data, u8 *mac,
-                                      struct ieee80211_vif *vif)
-{
-        unsigned long *data = _data;
-        struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
-
-        if (!mvmvif->phy_ctxt)
-                return;
-
-        if (vif->type == NL80211_IFTYPE_STATION ||
-            vif->type == NL80211_IFTYPE_AP)
-                __set_bit(mvmvif->phy_ctxt->id, data);
-}
-
 static bool iwl_mvm_power_allow_uapsd(struct iwl_mvm *mvm,
                                        struct ieee80211_vif *vif)
 {
         struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
-        unsigned long phy_ctxt_counter = 0;
-
-        ieee80211_iterate_active_interfaces_atomic(mvm->hw,
-                                                   IEEE80211_IFACE_ITER_NORMAL,
-                                                   iwl_mvm_binding_iterator,
-                                                   &phy_ctxt_counter);
 
         if (!memcmp(mvmvif->uapsd_misbehaving_bssid, vif->bss_conf.bssid,
                     ETH_ALEN))
@@ -291,7 +271,7 @@ static bool iwl_mvm_power_allow_uapsd(struct iwl_mvm *mvm,
          * Avoid using uAPSD if client is in DCM -
          * low latency issue in Miracast
          */
-        if (hweight8(phy_ctxt_counter) >= 2)
+        if (iwl_mvm_phy_ctx_count(mvm) >= 2)
                 return false;
 
         return true;