wifi: mt76: mt7996: fix TWT issues

[ Upstream commit 5c832c228f6a7ba7e900c5296ce0fb3844bafec5 ]

This patch fixes the following TWT issues:
- Change table_mask to u16 to support up to 16 TWT stations
- Reject TWT flows for duplicated establishment
- Fix possible unaligned pointer
- Remove unsupported TWT_CONTROL_WAKE_DUR_UNIT flag
- The minimum TWT duration supported by mt7996 chipsets is 64. Reply
  with TWT_SETUP_CMD_DICTATE if the min_twt_dur is smaller than 64

Fixes: 98686cd ("wifi: mt76: mt7996: add driver for MediaTek Wi-Fi 7 (802.11be) devices")
Signed-off-by: Peter Chiu <chui-hao.chiu@mediatek.com>
Signed-off-by: Shayne Chen <shayne.chen@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/net/wireless/mediatek/mt76/mt7996/mac.c

@@ -2433,6 +2433,34 @@ static int mt7996_mac_check_twt_req(struct ieee80211_twt_setup *twt)
 	return 0;
 }
 
+static bool
+mt7996_mac_twt_param_equal(struct mt7996_sta *msta,
+			   struct ieee80211_twt_params *twt_agrt)
+{
+	u16 type = le16_to_cpu(twt_agrt->req_type);
+	u8 exp;
+	int i;
+
+	exp = FIELD_GET(IEEE80211_TWT_REQTYPE_WAKE_INT_EXP, type);
+	for (i = 0; i < MT7996_MAX_STA_TWT_AGRT; i++) {
+		struct mt7996_twt_flow *f;
+
+		if (!(msta->twt.flowid_mask & BIT(i)))
+			continue;
+
+		f = &msta->twt.flow[i];
+		if (f->duration == twt_agrt->min_twt_dur &&
+		    f->mantissa == twt_agrt->mantissa &&
+		    f->exp == exp &&
+		    f->protection == !!(type & IEEE80211_TWT_REQTYPE_PROTECTION) &&
+		    f->flowtype == !!(type & IEEE80211_TWT_REQTYPE_FLOWTYPE) &&
+		    f->trigger == !!(type & IEEE80211_TWT_REQTYPE_TRIGGER))
+			return true;
+	}
+
+	return false;
+}
+
 void mt7996_mac_add_twt_setup(struct ieee80211_hw *hw,
 			      struct ieee80211_sta *sta,
 			      struct ieee80211_twt_setup *twt)
@@ -2444,8 +2472,7 @@ void mt7996_mac_add_twt_setup(struct ieee80211_hw *hw,
 	enum ieee80211_twt_setup_cmd sta_setup_cmd;
 	struct mt7996_dev *dev = mt7996_hw_dev(hw);
 	struct mt7996_twt_flow *flow;
-	int flowid, table_id;
-	u8 exp;
+	u8 flowid, table_id, exp;
 
 	if (mt7996_mac_check_twt_req(twt))
 		goto out;
@@ -2458,9 +2485,19 @@ void mt7996_mac_add_twt_setup(struct ieee80211_hw *hw,
 	if (hweight8(msta->twt.flowid_mask) == ARRAY_SIZE(msta->twt.flow))
 		goto unlock;
 
+	if (twt_agrt->min_twt_dur < MT7996_MIN_TWT_DUR) {
+		setup_cmd = TWT_SETUP_CMD_DICTATE;
+		twt_agrt->min_twt_dur = MT7996_MIN_TWT_DUR;
+		goto unlock;
+	}
+
+	if (mt7996_mac_twt_param_equal(msta, twt_agrt))
+		goto unlock;
+
 	flowid = ffs(~msta->twt.flowid_mask) - 1;
-	le16p_replace_bits(&twt_agrt->req_type, flowid,
-			   IEEE80211_TWT_REQTYPE_FLOWID);
+	twt_agrt->req_type &= ~cpu_to_le16(IEEE80211_TWT_REQTYPE_FLOWID);
+	twt_agrt->req_type |= le16_encode_bits(flowid,
+					       IEEE80211_TWT_REQTYPE_FLOWID);
 
 	table_id = ffs(~dev->twt.table_mask) - 1;
 	exp = FIELD_GET(IEEE80211_TWT_REQTYPE_WAKE_INT_EXP, req_type);
@@ -2507,10 +2544,10 @@ void mt7996_mac_add_twt_setup(struct ieee80211_hw *hw,
 unlock:
 	mutex_unlock(&dev->mt76.mutex);
 out:
-	le16p_replace_bits(&twt_agrt->req_type, setup_cmd,
-			   IEEE80211_TWT_REQTYPE_SETUP_CMD);
-	twt->control = (twt->control & IEEE80211_TWT_CONTROL_WAKE_DUR_UNIT) |
-		       (twt->control & IEEE80211_TWT_CONTROL_RX_DISABLED);
+	twt_agrt->req_type &= ~cpu_to_le16(IEEE80211_TWT_REQTYPE_SETUP_CMD);
+	twt_agrt->req_type |=
+		le16_encode_bits(setup_cmd, IEEE80211_TWT_REQTYPE_SETUP_CMD);
+	twt->control = twt->control & IEEE80211_TWT_CONTROL_RX_DISABLED;
 }
 
 void mt7996_mac_twt_teardown_flow(struct mt7996_dev *dev,

drivers/net/wireless/mediatek/mt76/mt7996/mt7996.h

@@ -43,6 +43,7 @@
 
 #define MT7996_MAX_TWT_AGRT		16
 #define MT7996_MAX_STA_TWT_AGRT		8
+#define MT7996_MIN_TWT_DUR		64
 #define MT7996_MAX_QUEUE		(__MT_RXQ_MAX +	__MT_MCUQ_MAX + 3)
 
 /* NOTE: used to map mt76_rates. idx may change if firmware expands table */
@@ -237,7 +238,7 @@ struct mt7996_dev {
 	struct rchan *relay_fwlog;
 
 	struct {
-		u8 table_mask;
+		u16 table_mask;
 		u8 n_agrt;
 	} twt;