mac80211: add radar detection command/event

Add command to trigger radar detection in the driver/FW.
Once radar detection is started it should continuously
monitor for radars as long as the channel active.
If radar is detected usermode notified with 'radar
detected' event.

Scanning and remain on channel functionality must be disabled
while doing radar detection/scanning, and vice versa.

Based on original patch by Victor Goldenshtein <victorg@ti.com>

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

10 files changed, 190 insertions, 1 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index e3dec80..0969978 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -928,6 +928,7 @@ static int ieee80211_start_ap(struct wiphy *wiphy, struct net_device *dev,
 	/* TODO: make hostapd tell us what it wants */
 	sdata->smps_mode = IEEE80211_SMPS_OFF;
 	sdata->needed_rx_chains = sdata->local->rx_chains;
+	sdata->radar_required = params->radar_required;
 
 	err = ieee80211_vif_use_channel(sdata, &params->chandef,
 					IEEE80211_CHANCTX_SHARED);
@@ -2395,7 +2396,8 @@ static int ieee80211_start_roc_work(struct ieee80211_local *local,
 	INIT_LIST_HEAD(&roc->dependents);
 
 	/* if there's one pending or we're scanning, queue this one */
-	if (!list_empty(&local->roc_list) || local->scanning)
+	if (!list_empty(&local->roc_list) ||
+	    local->scanning || local->radar_detect_enabled)
 		goto out_check_combine;
 
 	/* if not HW assist, just queue & schedule work */
@@ -2645,6 +2647,37 @@ static int ieee80211_cancel_remain_on_channel(struct wiphy *wiphy,
 	return ieee80211_cancel_roc(local, cookie, false);
 }
 
+static int ieee80211_start_radar_detection(struct wiphy *wiphy,
+					   struct net_device *dev,
+					   struct cfg80211_chan_def *chandef)
+{
+	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+	struct ieee80211_local *local = sdata->local;
+	unsigned long timeout;
+	int err;
+
+	if (!list_empty(&local->roc_list) || local->scanning)
+		return -EBUSY;
+
+	/* whatever, but channel contexts should not complain about that one */
+	sdata->smps_mode = IEEE80211_SMPS_OFF;
+	sdata->needed_rx_chains = local->rx_chains;
+	sdata->radar_required = true;
+
+	mutex_lock(&local->iflist_mtx);
+	err = ieee80211_vif_use_channel(sdata, chandef,
+					IEEE80211_CHANCTX_SHARED);
+	mutex_unlock(&local->iflist_mtx);
+	if (err)
+		return err;
+
+	timeout = msecs_to_jiffies(IEEE80211_DFS_MIN_CAC_TIME_MS);
+	ieee80211_queue_delayed_work(&sdata->local->hw,
+				     &sdata->dfs_cac_timer_work, timeout);
+
+	return 0;
+}
+
 static int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
 			     struct ieee80211_channel *chan, bool offchan,
 			     unsigned int wait, const u8 *buf, size_t len,
@@ -3350,4 +3383,5 @@ struct cfg80211_ops mac80211_config_ops = {
 	.get_et_stats = ieee80211_get_et_stats,
 	.get_et_strings = ieee80211_get_et_strings,
 	.get_channel = ieee80211_cfg_get_channel,
+	.start_radar_detection = ieee80211_start_radar_detection,
 };
diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index 038f249..2e6faed 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -193,6 +193,7 @@ static void ieee80211_unassign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
 	if (ctx->refcount > 0) {
 		ieee80211_recalc_chanctx_chantype(sdata->local, ctx);
 		ieee80211_recalc_smps_chanctx(local, ctx);
+		ieee80211_recalc_radar_chanctx(local, ctx);
 	}
 }
 
@@ -216,6 +217,37 @@ static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
 		ieee80211_free_chanctx(local, ctx);
 }
 
+void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
+				    struct ieee80211_chanctx *chanctx)
+{
+	struct ieee80211_sub_if_data *sdata;
+	bool radar_enabled = false;
+
+	lockdep_assert_held(&local->chanctx_mtx);
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
+		if (sdata->radar_required) {
+			radar_enabled = true;
+			break;
+		}
+	}
+	rcu_read_unlock();
+
+	if (radar_enabled == chanctx->conf.radar_enabled)
+		return;
+
+	chanctx->conf.radar_enabled = radar_enabled;
+	local->radar_detect_enabled = chanctx->conf.radar_enabled;
+
+	if (!local->use_chanctx) {
+		local->hw.conf.radar_enabled = chanctx->conf.radar_enabled;
+		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
+	}
+
+	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
+}
+
 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
 				   struct ieee80211_chanctx *chanctx)
 {
@@ -331,6 +363,7 @@ int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
 	}
 
 	ieee80211_recalc_smps_chanctx(local, ctx);
+	ieee80211_recalc_radar_chanctx(local, ctx);
  out:
 	mutex_unlock(&local->chanctx_mtx);
 	return ret;
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 76cdcfc..0e0a977 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -722,6 +722,9 @@ struct ieee80211_sub_if_data {
 	int user_power_level; /* in dBm */
 	int ap_power_level; /* in dBm */
 
+	bool radar_required;
+	struct delayed_work dfs_cac_timer_work;
+
 	/*
 	 * AP this belongs to: self in AP mode and
 	 * corresponding AP in VLAN mode, NULL for
@@ -942,6 +945,10 @@ struct ieee80211_local {
 	/* wowlan is enabled -- don't reconfig on resume */
 	bool wowlan;
 
+	/* DFS/radar detection is enabled */
+	bool radar_detect_enabled;
+	struct work_struct radar_detected_work;
+
 	/* number of RX chains the hardware has */
 	u8 rx_chains;
 
@@ -1606,6 +1613,13 @@ void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
 
 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
 				   struct ieee80211_chanctx *chanctx);
+void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
+				    struct ieee80211_chanctx *chanctx);
+
+void ieee80211_dfs_cac_timer(unsigned long data);
+void ieee80211_dfs_cac_timer_work(struct work_struct *work);
+void ieee80211_dfs_cac_cancel(struct ieee80211_local *local);
+void ieee80211_dfs_radar_detected_work(struct work_struct *work);
 
 #ifdef CONFIG_MAC80211_NOINLINE
 #define debug_noinline noinline
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 40ff030..e9223ce 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -749,6 +749,16 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata,
 
 	cancel_work_sync(&sdata->recalc_smps);
 
+	cancel_delayed_work_sync(&sdata->dfs_cac_timer_work);
+
+	if (sdata->wdev.cac_started) {
+		mutex_lock(&local->iflist_mtx);
+		ieee80211_vif_release_channel(sdata);
+		mutex_unlock(&local->iflist_mtx);
+		cfg80211_cac_event(sdata->dev, NL80211_RADAR_CAC_ABORTED,
+				   GFP_KERNEL);
+	}
+
 	/* APs need special treatment */
 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
 		struct ieee80211_sub_if_data *vlan, *tmpsdata;
@@ -1513,6 +1523,8 @@ int ieee80211_if_add(struct ieee80211_local *local, const char *name,
 	spin_lock_init(&sdata->cleanup_stations_lock);
 	INIT_LIST_HEAD(&sdata->cleanup_stations);
 	INIT_WORK(&sdata->cleanup_stations_wk, ieee80211_cleanup_sdata_stas_wk);
+	INIT_DELAYED_WORK(&sdata->dfs_cac_timer_work,
+			  ieee80211_dfs_cac_timer_work);
 
 	for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
 		struct ieee80211_supported_band *sband;
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 38b3468..9cdbc77 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -621,6 +621,9 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
 
 	INIT_WORK(&local->restart_work, ieee80211_restart_work);
 
+	INIT_WORK(&local->radar_detected_work,
+		  ieee80211_dfs_radar_detected_work);
+
 	INIT_WORK(&local->reconfig_filter, ieee80211_reconfig_filter);
 	local->smps_mode = IEEE80211_SMPS_OFF;
 
@@ -713,6 +716,16 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 		 */
 		if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_WDS))
 			return -EINVAL;
+
+		/* DFS currently not supported with channel context drivers */
+		for (i = 0; i < local->hw.wiphy->n_iface_combinations; i++) {
+			const struct ieee80211_iface_combination *comb;
+
+			comb = &local->hw.wiphy->iface_combinations[i];
+
+			if (comb->radar_detect_widths)
+				return -EINVAL;
+		}
 	}
 
 	/* Only HW csum features are currently compatible with mac80211 */
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index efb2276..7d4cde7 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1212,6 +1212,19 @@ void ieee80211_dynamic_ps_timer(unsigned long data)
 	ieee80211_queue_work(&local->hw, &local->dynamic_ps_enable_work);
 }
 
+void ieee80211_dfs_cac_timer_work(struct work_struct *work)
+{
+	struct delayed_work *delayed_work =
+		container_of(work, struct delayed_work, work);
+	struct ieee80211_sub_if_data *sdata =
+		container_of(delayed_work, struct ieee80211_sub_if_data,
+			     dfs_cac_timer_work);
+
+	ieee80211_vif_release_channel(sdata);
+
+	cfg80211_cac_event(sdata->dev, NL80211_RADAR_CAC_FINISHED, GFP_KERNEL);
+}
+
 /* MLME */
 static bool ieee80211_sta_wmm_params(struct ieee80211_local *local,
 				     struct ieee80211_sub_if_data *sdata,
diff --git a/net/mac80211/pm.c b/net/mac80211/pm.c
index 53801d2..d0275f3 100644
--- a/net/mac80211/pm.c
+++ b/net/mac80211/pm.c
@@ -38,6 +38,8 @@ int __ieee80211_suspend(struct ieee80211_hw *hw, struct cfg80211_wowlan *wowlan)
 
 	ieee80211_scan_cancel(local);
 
+	ieee80211_dfs_cac_cancel(local);
+
 	if (hw->flags & IEEE80211_HW_AMPDU_AGGREGATION) {
 		mutex_lock(&local->sta_mtx);
 		list_for_each_entry(sta, &local->sta_list, list) {
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 6d0b89e..43a45cf 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -351,6 +351,9 @@ static int ieee80211_start_sw_scan(struct ieee80211_local *local)
 static bool ieee80211_can_scan(struct ieee80211_local *local,
 			       struct ieee80211_sub_if_data *sdata)
 {
+	if (local->radar_detect_enabled)
+		return false;
+
 	if (!list_empty(&local->roc_list))
 		return false;
 
diff --git a/net/mac80211/trace.h b/net/mac80211/trace.h
index 0bdd7ae..1183c4a 100644
--- a/net/mac80211/trace.h
+++ b/net/mac80211/trace.h
@@ -1862,6 +1862,25 @@ TRACE_EVENT(drv_set_default_unicast_key,
 		  LOCAL_PR_ARG, VIF_PR_ARG, __entry->key_idx)
 );
 
+TRACE_EVENT(api_radar_detected,
+	TP_PROTO(struct ieee80211_local *local),
+
+	TP_ARGS(local),
+
+	TP_STRUCT__entry(
+		LOCAL_ENTRY
+	),
+
+	TP_fast_assign(
+		LOCAL_ASSIGN;
+	),
+
+	TP_printk(
+		LOCAL_PR_FMT " radar detected",
+		LOCAL_PR_ARG
+	)
+);
+
 #ifdef CONFIG_MAC80211_MESSAGE_TRACING
 #undef TRACE_SYSTEM
 #define TRACE_SYSTEM mac80211_msg
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 6cb71a3..218cb52 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -2133,3 +2133,49 @@ u64 ieee80211_calculate_rx_timestamp(struct ieee80211_local *local,
 
 	return ts;
 }
+
+void ieee80211_dfs_cac_cancel(struct ieee80211_local *local)
+{
+	struct ieee80211_sub_if_data *sdata;
+
+	mutex_lock(&local->iflist_mtx);
+	list_for_each_entry(sdata, &local->interfaces, list) {
+		cancel_delayed_work_sync(&sdata->dfs_cac_timer_work);
+
+		if (sdata->wdev.cac_started) {
+			ieee80211_vif_release_channel(sdata);
+			cfg80211_cac_event(sdata->dev,
+					   NL80211_RADAR_CAC_ABORTED,
+					   GFP_KERNEL);
+		}
+	}
+	mutex_unlock(&local->iflist_mtx);
+}
+
+void ieee80211_dfs_radar_detected_work(struct work_struct *work)
+{
+	struct ieee80211_local *local =
+		container_of(work, struct ieee80211_local, radar_detected_work);
+	struct cfg80211_chan_def chandef;
+
+	ieee80211_dfs_cac_cancel(local);
+
+	if (local->use_chanctx)
+		/* currently not handled */
+		WARN_ON(1);
+	else {
+		cfg80211_chandef_create(&chandef, local->hw.conf.channel,
+					local->hw.conf.channel_type);
+		cfg80211_radar_event(local->hw.wiphy, &chandef, GFP_KERNEL);
+	}
+}
+
+void ieee80211_radar_detected(struct ieee80211_hw *hw)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+
+	trace_api_radar_detected(local);
+
+	ieee80211_queue_work(hw, &local->radar_detected_work);
+}
+EXPORT_SYMBOL(ieee80211_radar_detected);