wifi: mt76: mt7996: add eht rx rate support

Add support to report eht rx rate.
Note that extended fields for eht in mt76_rx_status will make the struct
size exceed the cb size, so make nss and band share the same u8.
Signed-off-by: Shayne Chen <shayne.chen@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mac80211.c

@@ -1067,9 +1067,14 @@ mt76_rx_convert(struct mt76_dev *dev, struct sk_buff *skb,
 	status->enc_flags = mstat.enc_flags;
 	status->encoding = mstat.encoding;
 	status->bw = mstat.bw;
+	if (status->encoding == RX_ENC_EHT) {
+		status->eht.ru = mstat.eht.ru;
+		status->eht.gi = mstat.eht.gi;
+	} else {
 		status->he_ru = mstat.he_ru;
 		status->he_gi = mstat.he_gi;
 		status->he_dcm = mstat.he_dcm;
+	}
 	status->rate_idx = mstat.rate_idx;
 	status->nss = mstat.nss;
 	status->band = mstat.band;

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

@@ -621,12 +621,22 @@ struct mt76_rx_status {
 	u16 freq;
 	u32 flag;
 	u8 enc_flags;
-	u8 encoding:2, bw:3, he_ru:3;
-	u8 he_gi:2, he_dcm:1;
+	u8 encoding:3, bw:4;
+	union {
+		struct {
+			u8 he_ru:3;
+			u8 he_gi:2;
+			u8 he_dcm:1;
+		};
+		struct {
+			u8 ru:4;
+			u8 gi:2;
+		} eht;
+	};
+
 	u8 amsdu:1, first_amsdu:1, last_amsdu:1;
 	u8 rate_idx;
-	u8 nss;
-	u8 band;
+	u8 nss:5, band:3;
 	s8 signal;
 	u8 chains;
 	s8 chain_signal[IEEE80211_MAX_CHAINS];

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

@@ -572,11 +572,12 @@ mt7996_mac_fill_rx_rate(struct mt7996_dev *dev,
 	case MT_PHY_TYPE_EHT_SU:
 	case MT_PHY_TYPE_EHT_TRIG:
 	case MT_PHY_TYPE_EHT_MU:
-		/* TODO: currently report rx rate with HE rate */
 		status->nss = nss;
-		status->encoding = RX_ENC_HE;
-		bw = min_t(int, bw, IEEE80211_STA_RX_BW_160);
-		i = min_t(int, i & 0xf, 11);
+		status->encoding = RX_ENC_EHT;
+		i &= GENMASK(3, 0);
+
+		if (gi <= NL80211_RATE_INFO_EHT_GI_3_2)
+			status->eht.gi = gi;
 		break;
 	default:
 		return -EINVAL;