mac80211: track needed RX chains for channel contexts

On each channel that the device is operating on, it
may need to listen using one or more chains depending
on the SMPS settings of the interfaces using it. The
previous channel context changes completely removed
this ability (before, it was available as the SMPS
mode).

Add per-context tracking of the required static and
dynamic RX chains and notify the driver on changes.
To achieve this, track the chains and SMPS mode used
on each virtual interface and update the channel
context whenever this changes.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 89 insertions, 1 deletions

diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index 41e1aa69f7aa..bfaa486d928c 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -118,6 +118,8 @@ ieee80211_new_chanctx(struct ieee80211_local *local,
 
 	ctx->conf.channel = channel;
 	ctx->conf.channel_type = channel_type;
+	ctx->conf.rx_chains_static = 1;
+	ctx->conf.rx_chains_dynamic = 1;
 	ctx->mode = mode;
 
 	if (!local->use_chanctx) {
@@ -222,8 +224,10 @@ static void ieee80211_unassign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
 
 	drv_unassign_vif_chanctx(local, sdata, ctx);
 
-	if (ctx->refcount > 0)
+	if (ctx->refcount > 0) {
 		ieee80211_recalc_chanctx_chantype(sdata->local, ctx);
+		ieee80211_recalc_smps_chanctx(local, ctx);
+	}
 }
 
 static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
@@ -246,6 +250,89 @@ static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
 		ieee80211_free_chanctx(local, ctx);
 }
 
+void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
+				   struct ieee80211_chanctx *chanctx)
+{
+	struct ieee80211_sub_if_data *sdata;
+	u8 rx_chains_static, rx_chains_dynamic;
+
+	lockdep_assert_held(&local->chanctx_mtx);
+
+	rx_chains_static = 1;
+	rx_chains_dynamic = 1;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
+		u8 needed_static, needed_dynamic;
+
+		if (!ieee80211_sdata_running(sdata))
+			continue;
+
+		if (rcu_access_pointer(sdata->vif.chanctx_conf) !=
+						&chanctx->conf)
+			continue;
+
+		switch (sdata->vif.type) {
+		case NL80211_IFTYPE_P2P_DEVICE:
+			continue;
+		case NL80211_IFTYPE_STATION:
+			if (!sdata->u.mgd.associated)
+				continue;
+			break;
+		case NL80211_IFTYPE_AP_VLAN:
+			continue;
+		case NL80211_IFTYPE_AP:
+		case NL80211_IFTYPE_ADHOC:
+		case NL80211_IFTYPE_WDS:
+		case NL80211_IFTYPE_MESH_POINT:
+			break;
+		default:
+			WARN_ON_ONCE(1);
+		}
+
+		switch (sdata->smps_mode) {
+		default:
+			WARN_ONCE(1, "Invalid SMPS mode %d\n",
+				  sdata->smps_mode);
+			/* fall through */
+		case IEEE80211_SMPS_OFF:
+			needed_static = sdata->needed_rx_chains;
+			needed_dynamic = sdata->needed_rx_chains;
+			break;
+		case IEEE80211_SMPS_DYNAMIC:
+			needed_static = 1;
+			needed_dynamic = sdata->needed_rx_chains;
+			break;
+		case IEEE80211_SMPS_STATIC:
+			needed_static = 1;
+			needed_dynamic = 1;
+			break;
+		}
+
+		rx_chains_static = max(rx_chains_static, needed_static);
+		rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
+	}
+	rcu_read_unlock();
+
+	if (!local->use_chanctx) {
+		if (rx_chains_static > 1)
+			local->smps_mode = IEEE80211_SMPS_OFF;
+		else if (rx_chains_dynamic > 1)
+			local->smps_mode = IEEE80211_SMPS_DYNAMIC;
+		else
+			local->smps_mode = IEEE80211_SMPS_STATIC;
+		ieee80211_hw_config(local, 0);
+	}
+
+	if (rx_chains_static == chanctx->conf.rx_chains_static &&
+	    rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
+		return;
+
+	chanctx->conf.rx_chains_static = rx_chains_static;
+	chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
+	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
+}
+
 int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
 			      struct ieee80211_channel *channel,
 			      enum nl80211_channel_type channel_type,
@@ -278,6 +365,7 @@ int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
 		goto out;
 	}
 
+	ieee80211_recalc_smps_chanctx(local, ctx);
  out:
 	mutex_unlock(&local->chanctx_mtx);
 	return ret;