iwlwifi: implement switching iftype while up

Implement switching the interface while an
interface is up in iwlwifi. Interfaces have
to stay on the context they were created on.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

5 files changed, 130 insertions, 44 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-4965.c b/drivers/net/wireless/iwlwifi/iwl-4965.c
index 8f07964e4305..6d313c817040 100644
--- a/drivers/net/wireless/iwlwifi/iwl-4965.c
+++ b/drivers/net/wireless/iwlwifi/iwl-4965.c
@@ -2589,6 +2589,7 @@ struct ieee80211_ops iwl4965_hw_ops = {
         .stop = iwlagn_mac_stop,
         .add_interface = iwl_mac_add_interface,
         .remove_interface = iwl_mac_remove_interface,
+        .change_interface = iwl_mac_change_interface,
         .config = iwl_legacy_mac_config,
         .configure_filter = iwlagn_configure_filter,
         .set_key = iwlagn_mac_set_key,
diff --git a/drivers/net/wireless/iwlwifi/iwl-agn.c b/drivers/net/wireless/iwlwifi/iwl-agn.c
index 1050f31d90a4..481c993c2491 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn.c
@@ -3909,6 +3909,7 @@ struct ieee80211_ops iwlagn_hw_ops = {
         .stop = iwlagn_mac_stop,
         .add_interface = iwl_mac_add_interface,
         .remove_interface = iwl_mac_remove_interface,
+        .change_interface = iwl_mac_change_interface,
         .config = iwlagn_mac_config,
         .configure_filter = iwlagn_configure_filter,
         .set_key = iwlagn_mac_set_key,
diff --git a/drivers/net/wireless/iwlwifi/iwl-core.c b/drivers/net/wireless/iwlwifi/iwl-core.c
index 776713c6a7ff..180d09ec3136 100644
--- a/drivers/net/wireless/iwlwifi/iwl-core.c
+++ b/drivers/net/wireless/iwlwifi/iwl-core.c
@@ -1427,10 +1427,8 @@ int iwl_mac_tx_last_beacon(struct ieee80211_hw *hw)
 }
 EXPORT_SYMBOL_GPL(iwl_mac_tx_last_beacon);
 
-static int iwl_set_mode(struct iwl_priv *priv, struct ieee80211_vif *vif)
+static int iwl_set_mode(struct iwl_priv *priv, struct iwl_rxon_context *ctx)
 {
-        struct iwl_rxon_context *ctx = iwl_rxon_ctx_from_vif(vif);
-
         iwl_connection_init_rx_config(priv, ctx);
 
         if (priv->cfg->ops->hcmd->set_rxon_chain)
@@ -1439,12 +1437,49 @@ static int iwl_set_mode(struct iwl_priv *priv, struct ieee80211_vif *vif)
         return iwlcore_commit_rxon(priv, ctx);
 }
 
+static int iwl_setup_interface(struct iwl_priv *priv,
+                               struct iwl_rxon_context *ctx)
+{
+        struct ieee80211_vif *vif = ctx->vif;
+        int err;
+
+        lockdep_assert_held(&priv->mutex);
+
+        /*
+         * This variable will be correct only when there's just
+         * a single context, but all code using it is for hardware
+         * that supports only one context.
+         */
+        priv->iw_mode = vif->type;
+
+        ctx->is_active = true;
+
+        err = iwl_set_mode(priv, ctx);
+        if (err) {
+                if (!ctx->always_active)
+                        ctx->is_active = false;
+                return err;
+        }
+
+        if (priv->cfg->bt_params && priv->cfg->bt_params->advanced_bt_coexist &&
+            vif->type == NL80211_IFTYPE_ADHOC) {
+                /*
+                 * pretend to have high BT traffic as long as we
+                 * are operating in IBSS mode, as this will cause
+                 * the rate scaling etc. to behave as intended.
+                 */
+                priv->bt_traffic_load = IWL_BT_COEX_TRAFFIC_LOAD_HIGH;
+        }
+
+        return 0;
+}
+
 int iwl_mac_add_interface(struct ieee80211_hw *hw, struct ieee80211_vif *vif)
 {
         struct iwl_priv *priv = hw->priv;
         struct iwl_vif_priv *vif_priv = (void *)vif->drv_priv;
         struct iwl_rxon_context *tmp, *ctx = NULL;
-        int err = 0;
+        int err;
 
         IWL_DEBUG_MAC80211(priv, "enter: type %d, addr %pM\n",
                            vif->type, vif->addr);
@@ -1486,36 +1521,11 @@ int iwl_mac_add_interface(struct ieee80211_hw *hw, struct ieee80211_vif *vif)
 
         vif_priv->ctx = ctx;
         ctx->vif = vif;
-        /*
-         * This variable will be correct only when there's just
-         * a single context, but all code using it is for hardware
-         * that supports only one context.
-         */
-        priv->iw_mode = vif->type;
-
-        ctx->is_active = true;
-
-        err = iwl_set_mode(priv, vif);
-        if (err) {
-                if (!ctx->always_active)
-                        ctx->is_active = false;
-                goto out_err;
-        }
-
-        if (priv->cfg->bt_params &&
-            priv->cfg->bt_params->advanced_bt_coexist &&
-            vif->type == NL80211_IFTYPE_ADHOC) {
-                /*
-                 * pretend to have high BT traffic as long as we
-                 * are operating in IBSS mode, as this will cause
-                 * the rate scaling etc. to behave as intended.
-                 */
-                priv->bt_traffic_load = IWL_BT_COEX_TRAFFIC_LOAD_HIGH;
-        }
 
-        goto out;
+        err = iwl_setup_interface(priv, ctx);
+        if (!err)
+                goto out;
 
- out_err:
         ctx->vif = NULL;
         priv->iw_mode = NL80211_IFTYPE_STATION;
  out:
@@ -1526,27 +1536,24 @@ int iwl_mac_add_interface(struct ieee80211_hw *hw, struct ieee80211_vif *vif)
 }
 EXPORT_SYMBOL(iwl_mac_add_interface);
 
-void iwl_mac_remove_interface(struct ieee80211_hw *hw,
-                              struct ieee80211_vif *vif)
+static void iwl_teardown_interface(struct iwl_priv *priv,
+                                   struct ieee80211_vif *vif,
+                                   bool mode_change)
 {
-        struct iwl_priv *priv = hw->priv;
         struct iwl_rxon_context *ctx = iwl_rxon_ctx_from_vif(vif);
 
-        IWL_DEBUG_MAC80211(priv, "enter\n");
-
-        mutex_lock(&priv->mutex);
-
-        WARN_ON(ctx->vif != vif);
-        ctx->vif = NULL;
+        lockdep_assert_held(&priv->mutex);
 
         if (priv->scan_vif == vif) {
                 iwl_scan_cancel_timeout(priv, 200);
                 iwl_force_scan_end(priv);
         }
-        iwl_set_mode(priv, vif);
 
-        if (!ctx->always_active)
-                ctx->is_active = false;
+        if (!mode_change) {
+                iwl_set_mode(priv, ctx);
+                if (!ctx->always_active)
+                        ctx->is_active = false;
+        }
 
         /*
          * When removing the IBSS interface, overwrite the
@@ -1557,6 +1564,22 @@ void iwl_mac_remove_interface(struct ieee80211_hw *hw,
          */
         if (vif->type == NL80211_IFTYPE_ADHOC)
                 priv->bt_traffic_load = priv->notif_bt_traffic_load;
+}
+
+void iwl_mac_remove_interface(struct ieee80211_hw *hw,
+                              struct ieee80211_vif *vif)
+{
+        struct iwl_priv *priv = hw->priv;
+        struct iwl_rxon_context *ctx = iwl_rxon_ctx_from_vif(vif);
+
+        IWL_DEBUG_MAC80211(priv, "enter\n");
+
+        mutex_lock(&priv->mutex);
+
+        WARN_ON(ctx->vif != vif);
+        ctx->vif = NULL;
+
+        iwl_teardown_interface(priv, vif, false);
 
         memset(priv->bssid, 0, ETH_ALEN);
         mutex_unlock(&priv->mutex);
@@ -1908,6 +1931,63 @@ int iwl_force_reset(struct iwl_priv *priv, int mode, bool external)
         return 0;
 }
 
+int iwl_mac_change_interface(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
+                             enum nl80211_iftype newtype, bool newp2p)
+{
+        struct iwl_priv *priv = hw->priv;
+        struct iwl_rxon_context *ctx = iwl_rxon_ctx_from_vif(vif);
+        struct iwl_rxon_context *tmp;
+        u32 interface_modes;
+        int err;
+
+        newtype = ieee80211_iftype_p2p(newtype, newp2p);
+
+        mutex_lock(&priv->mutex);
+
+        interface_modes = ctx->interface_modes | ctx->exclusive_interface_modes;
+
+        if (!(interface_modes & BIT(newtype))) {
+                err = -EBUSY;
+                goto out;
+        }
+
+        if (ctx->exclusive_interface_modes & BIT(newtype)) {
+                for_each_context(priv, tmp) {
+                        if (ctx == tmp)
+                                continue;
+
+                        if (!tmp->vif)
+                                continue;
+
+                        /*
+                         * The current mode switch would be exclusive, but
+                         * another context is active ... refuse the switch.
+                         */
+                        err = -EBUSY;
+                        goto out;
+                }
+        }
+
+        /* success */
+        iwl_teardown_interface(priv, vif, true);
+        vif->type = newtype;
+        err = iwl_setup_interface(priv, ctx);
+        WARN_ON(err);
+        /*
+         * We've switched internally, but submitting to the
+         * device may have failed for some reason. Mask this
+         * error, because otherwise mac80211 will not switch
+         * (and set the interface type back) and we'll be
+         * out of sync with it.
+         */
+        err = 0;
+
+ out:
+        mutex_unlock(&priv->mutex);
+        return err;
+}
+EXPORT_SYMBOL(iwl_mac_change_interface);
+
 /**
  * iwl_bg_monitor_recover - Timer callback to check for stuck queue and recover
  *
diff --git a/drivers/net/wireless/iwlwifi/iwl-core.h b/drivers/net/wireless/iwlwifi/iwl-core.h
index 854613e4f2be..8fb063affac4 100644
--- a/drivers/net/wireless/iwlwifi/iwl-core.h
+++ b/drivers/net/wireless/iwlwifi/iwl-core.h
@@ -432,6 +432,9 @@ int iwl_mac_add_interface(struct ieee80211_hw *hw,
                           struct ieee80211_vif *vif);
 void iwl_mac_remove_interface(struct ieee80211_hw *hw,
                               struct ieee80211_vif *vif);
+int iwl_mac_change_interface(struct ieee80211_hw *hw,
+                             struct ieee80211_vif *vif,
+                             enum nl80211_iftype newtype, bool newp2p);
 int iwl_alloc_txq_mem(struct iwl_priv *priv);
 void iwl_free_txq_mem(struct iwl_priv *priv);
 void iwlcore_tx_cmd_protection(struct iwl_priv *priv,
diff --git a/drivers/net/wireless/iwlwifi/iwl3945-base.c b/drivers/net/wireless/iwlwifi/iwl3945-base.c
index 73f2f3fcb49c..6152a86c19b5 100644
--- a/drivers/net/wireless/iwlwifi/iwl3945-base.c
+++ b/drivers/net/wireless/iwlwifi/iwl3945-base.c
@@ -3832,6 +3832,7 @@ struct ieee80211_ops iwl3945_hw_ops = {
         .stop = iwl3945_mac_stop,
         .add_interface = iwl_mac_add_interface,
         .remove_interface = iwl_mac_remove_interface,
+        .change_interface = iwl_mac_change_interface,
         .config = iwl_legacy_mac_config,
         .configure_filter = iwl3945_configure_filter,
         .set_key = iwl3945_mac_set_key,