mac80211: enable spatial multiplexing powersave

Enable spatial multiplexing in mac80211 by telling the
driver what to do and, where necessary, sending action
frames to the AP to update the requested SMPS mode.

Also includes a trivial implementation for hwsim that
just logs the requested mode.

For now, the userspace interface is in debugfs only,
and let you toggle the requested mode at any time.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 47 insertions, 0 deletions

diff --git a/net/mac80211/ht.c b/net/mac80211/ht.c
index 45ebd06..63b8f86 100644
--- a/net/mac80211/ht.c
+++ b/net/mac80211/ht.c
@@ -166,3 +166,50 @@ void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
 		spin_unlock_bh(&sta->lock);
 	}
 }
+
+int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
+			       enum ieee80211_smps_mode smps, const u8 *da,
+			       const u8 *bssid)
+{
+	struct ieee80211_local *local = sdata->local;
+	struct sk_buff *skb;
+	struct ieee80211_mgmt *action_frame;
+
+	/* 27 = header + category + action + smps mode */
+	skb = dev_alloc_skb(27 + local->hw.extra_tx_headroom);
+	if (!skb)
+		return -ENOMEM;
+
+	skb_reserve(skb, local->hw.extra_tx_headroom);
+	action_frame = (void *)skb_put(skb, 27);
+	memcpy(action_frame->da, da, ETH_ALEN);
+	memcpy(action_frame->sa, sdata->dev->dev_addr, ETH_ALEN);
+	memcpy(action_frame->bssid, bssid, ETH_ALEN);
+	action_frame->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
+						  IEEE80211_STYPE_ACTION);
+	action_frame->u.action.category = WLAN_CATEGORY_HT;
+	action_frame->u.action.u.ht_smps.action = WLAN_HT_ACTION_SMPS;
+	switch (smps) {
+	case IEEE80211_SMPS_AUTOMATIC:
+	case IEEE80211_SMPS_NUM_MODES:
+		WARN_ON(1);
+	case IEEE80211_SMPS_OFF:
+		action_frame->u.action.u.ht_smps.smps_control =
+				WLAN_HT_SMPS_CONTROL_DISABLED;
+		break;
+	case IEEE80211_SMPS_STATIC:
+		action_frame->u.action.u.ht_smps.smps_control =
+				WLAN_HT_SMPS_CONTROL_STATIC;
+		break;
+	case IEEE80211_SMPS_DYNAMIC:
+		action_frame->u.action.u.ht_smps.smps_control =
+				WLAN_HT_SMPS_CONTROL_DYNAMIC;
+		break;
+	}
+
+	/* we'll do more on status of this frame */
+	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
+	ieee80211_tx_skb(sdata, skb);
+
+	return 0;
+}