mac80211: Allow drivers to differentiate between ROC types

Some devices can handle remain on channel requests differently
based on the request type/priority. Add support to
differentiate between different ROC types, i.e., indicate that
the ROC is required for sending managment frames.
Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/iwlwifi/dvm/mac80211.c

@@ -1137,7 +1137,8 @@ static void iwlagn_mac_flush(struct ieee80211_hw *hw, bool drop)
 static int iwlagn_mac_remain_on_channel(struct ieee80211_hw *hw,
 				     struct ieee80211_vif *vif,
 				     struct ieee80211_channel *channel,
-				     int duration)
+				     int duration,
+				     enum ieee80211_roc_type type)
 {
 	struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);
 	struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_PAN];

drivers/net/wireless/iwlwifi/mvm/mac80211.c

@@ -1081,7 +1081,8 @@ static void iwl_mvm_mac_update_tkip_key(struct ieee80211_hw *hw,
 static int iwl_mvm_roc(struct ieee80211_hw *hw,
 		       struct ieee80211_vif *vif,
 		       struct ieee80211_channel *channel,
-		       int duration)
+		       int duration,
+		       enum ieee80211_roc_type type)
 {
 	struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
 	struct cfg80211_chan_def chandef;
@@ -1092,8 +1093,8 @@ static int iwl_mvm_roc(struct ieee80211_hw *hw,
 		return -EINVAL;
 	}
 
-	IWL_DEBUG_MAC80211(mvm, "enter (%d, %d)\n", channel->hw_value,
-			   duration);
+	IWL_DEBUG_MAC80211(mvm, "enter (%d, %d, %d)\n", channel->hw_value,
+			   duration, type);
 
 	mutex_lock(&mvm->mutex);
 

drivers/net/wireless/mac80211_hwsim.c

@@ -1535,7 +1535,8 @@ static void hw_roc_done(struct work_struct *work)
 static int mac80211_hwsim_roc(struct ieee80211_hw *hw,
 			      struct ieee80211_vif *vif,
 			      struct ieee80211_channel *chan,
-			      int duration)
+			      int duration,
+			      enum ieee80211_roc_type type)
 {
 	struct mac80211_hwsim_data *hwsim = hw->priv;
 

drivers/net/wireless/ti/wlcore/main.c

@@ -4956,7 +4956,8 @@ static void wlcore_op_flush(struct ieee80211_hw *hw, bool drop)
 static int wlcore_op_remain_on_channel(struct ieee80211_hw *hw,
 				       struct ieee80211_vif *vif,
 				       struct ieee80211_channel *chan,
-				       int duration)
+				       int duration,
+				       enum ieee80211_roc_type type)
 {
 	struct wl12xx_vif *wlvif = wl12xx_vif_to_data(vif);
 	struct wl1271 *wl = hw->priv;

include/net/mac80211.h

@@ -2134,6 +2134,24 @@ enum ieee80211_rate_control_changed {
 	IEEE80211_RC_NSS_CHANGED	= BIT(3),
 };
 
+/**
+ * enum ieee80211_roc_type - remain on channel type
+ *
+ * With the support for multi channel contexts and multi channel operations,
+ * remain on channel operations might be limited/deferred/aborted by other
+ * flows/operations which have higher priority (and vise versa).
+ * Specifying the ROC type can be used by devices to prioritize the ROC
+ * operations compared to other operations/flows.
+ *
+ * @IEEE80211_ROC_TYPE_NORMAL: There are no special requirements for this ROC.
+ * @IEEE80211_ROC_TYPE_MGMT_TX: The remain on channel request is required
+ *	for sending managment frames offchannel.
+ */
+enum ieee80211_roc_type {
+	IEEE80211_ROC_TYPE_NORMAL = 0,
+	IEEE80211_ROC_TYPE_MGMT_TX,
+};
+
 /**
  * struct ieee80211_ops - callbacks from mac80211 to the driver
  *
@@ -2687,7 +2705,8 @@ struct ieee80211_ops {
 	int (*remain_on_channel)(struct ieee80211_hw *hw,
 				 struct ieee80211_vif *vif,
 				 struct ieee80211_channel *chan,
-				 int duration);
+				 int duration,
+				 enum ieee80211_roc_type type);
 	int (*cancel_remain_on_channel)(struct ieee80211_hw *hw);
 	int (*set_ringparam)(struct ieee80211_hw *hw, u32 tx, u32 rx);
 	void (*get_ringparam)(struct ieee80211_hw *hw,

net/mac80211/cfg.c

@@ -2410,7 +2410,8 @@ static int ieee80211_start_roc_work(struct ieee80211_local *local,
 				    struct ieee80211_sub_if_data *sdata,
 				    struct ieee80211_channel *channel,
 				    unsigned int duration, u64 *cookie,
-				    struct sk_buff *txskb)
+				    struct sk_buff *txskb,
+				    enum ieee80211_roc_type type)
 {
 	struct ieee80211_roc_work *roc, *tmp;
 	bool queued = false;
@@ -2429,6 +2430,7 @@ static int ieee80211_start_roc_work(struct ieee80211_local *local,
 	roc->duration = duration;
 	roc->req_duration = duration;
 	roc->frame = txskb;
+	roc->type = type;
 	roc->mgmt_tx_cookie = (unsigned long)txskb;
 	roc->sdata = sdata;
 	INIT_DELAYED_WORK(&roc->work, ieee80211_sw_roc_work);
@@ -2459,7 +2461,7 @@ static int ieee80211_start_roc_work(struct ieee80211_local *local,
 	if (!duration)
 		duration = 10;
 
-	ret = drv_remain_on_channel(local, sdata, channel, duration);
+	ret = drv_remain_on_channel(local, sdata, channel, duration, type);
 	if (ret) {
 		kfree(roc);
 		return ret;
@@ -2478,10 +2480,13 @@ static int ieee80211_start_roc_work(struct ieee80211_local *local,
 		 *
 		 * If it hasn't started yet, just increase the duration
 		 * and add the new one to the list of dependents.
+		 * If the type of the new ROC has higher priority, modify the
+		 * type of the previous one to match that of the new one.
 		 */
 		if (!tmp->started) {
 			list_add_tail(&roc->list, &tmp->dependents);
 			tmp->duration = max(tmp->duration, roc->duration);
+			tmp->type = max(tmp->type, roc->type);
 			queued = true;
 			break;
 		}
@@ -2493,16 +2498,18 @@ static int ieee80211_start_roc_work(struct ieee80211_local *local,
 			/*
 			 * In the offloaded ROC case, if it hasn't begun, add
 			 * this new one to the dependent list to be handled
-			 * when the the master one begins. If it has begun,
+			 * when the master one begins. If it has begun,
 			 * check that there's still a minimum time left and
 			 * if so, start this one, transmitting the frame, but
-			 * add it to the list directly after this one with a
+			 * add it to the list directly after this one with
 			 * a reduced time so we'll ask the driver to execute
 			 * it right after finishing the previous one, in the
 			 * hope that it'll also be executed right afterwards,
 			 * effectively extending the old one.
 			 * If there's no minimum time left, just add it to the
 			 * normal list.
+			 * TODO: the ROC type is ignored here, assuming that it
+			 * is better to immediately use the current ROC.
 			 */
 			if (!tmp->hw_begun) {
 				list_add_tail(&roc->list, &tmp->dependents);
@@ -2596,7 +2603,8 @@ static int ieee80211_remain_on_channel(struct wiphy *wiphy,
 
 	mutex_lock(&local->mtx);
 	ret = ieee80211_start_roc_work(local, sdata, chan,
-				       duration, cookie, NULL);
+				       duration, cookie, NULL,
+				       IEEE80211_ROC_TYPE_NORMAL);
 	mutex_unlock(&local->mtx);
 
 	return ret;
@@ -2829,7 +2837,8 @@ static int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
 
 	/* This will handle all kinds of coalescing and immediate TX */
 	ret = ieee80211_start_roc_work(local, sdata, chan,
-				       wait, cookie, skb);
+				       wait, cookie, skb,
+				       IEEE80211_ROC_TYPE_MGMT_TX);
 	if (ret)
 		kfree_skb(skb);
  out_unlock:

net/mac80211/driver-ops.h

@@ -787,15 +787,16 @@ static inline int drv_get_antenna(struct ieee80211_local *local,
 static inline int drv_remain_on_channel(struct ieee80211_local *local,
 					struct ieee80211_sub_if_data *sdata,
 					struct ieee80211_channel *chan,
-					unsigned int duration)
+					unsigned int duration,
+					enum ieee80211_roc_type type)
 {
 	int ret;
 
 	might_sleep();
 
-	trace_drv_remain_on_channel(local, sdata, chan, duration);
+	trace_drv_remain_on_channel(local, sdata, chan, duration, type);
 	ret = local->ops->remain_on_channel(&local->hw, &sdata->vif,
-					    chan, duration);
+					    chan, duration, type);
 	trace_drv_return_int(local, ret);
 
 	return ret;

net/mac80211/ieee80211_i.h

@@ -315,6 +315,7 @@ struct ieee80211_roc_work {
 	u32 duration, req_duration;
 	struct sk_buff *frame;
 	u64 cookie, mgmt_tx_cookie;
+	enum ieee80211_roc_type type;
 };
 
 /* flags used in struct ieee80211_if_managed.flags */

net/mac80211/offchannel.c

@@ -277,7 +277,7 @@ void ieee80211_start_next_roc(struct ieee80211_local *local)
 			duration = 10;
 
 		ret = drv_remain_on_channel(local, roc->sdata, roc->chan,
-					    duration);
+					    duration, roc->type);
 
 		roc->started = true;
 

net/mac80211/trace.h

@@ -1042,15 +1042,17 @@ TRACE_EVENT(drv_remain_on_channel,
 	TP_PROTO(struct ieee80211_local *local,
 		 struct ieee80211_sub_if_data *sdata,
 		 struct ieee80211_channel *chan,
-		 unsigned int duration),
+		 unsigned int duration,
+		 enum ieee80211_roc_type type),
 
-	TP_ARGS(local, sdata, chan, duration),
+	TP_ARGS(local, sdata, chan, duration, type),
 
 	TP_STRUCT__entry(
 		LOCAL_ENTRY
 		VIF_ENTRY
 		__field(int, center_freq)
 		__field(unsigned int, duration)
+		__field(u32, type)
 	),
 
 	TP_fast_assign(
@@ -1058,12 +1060,13 @@ TRACE_EVENT(drv_remain_on_channel,
 		VIF_ASSIGN;
 		__entry->center_freq = chan->center_freq;
 		__entry->duration = duration;
+		__entry->type = type;
 	),
 
 	TP_printk(
-		LOCAL_PR_FMT  VIF_PR_FMT " freq:%dMHz duration:%dms",
+		LOCAL_PR_FMT  VIF_PR_FMT " freq:%dMHz duration:%dms type=%d",
 		LOCAL_PR_ARG, VIF_PR_ARG,
-		__entry->center_freq, __entry->duration
+		__entry->center_freq, __entry->duration, __entry->type
 	)
 );