mac80211: reduce peer HE MCS/NSS to own capabilities

For VHT capbility, we do intersection of MCS and NSS for peers in
mac80211, to simplify drivers.

Add this for HE as well.
Signed-off-by: Wen Gong <wgong@codeaurora.org>
Link: https://lore.kernel.org/r/1609816120-9411-3-git-send-email-wgong@codeaurora.org
[reword commit message, style cleanups, fix endian annotations]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/he.c

@@ -52,6 +52,57 @@ ieee80211_update_from_he_6ghz_capa(const struct ieee80211_he_6ghz_capa *he_6ghz_
 	sta->sta.he_6ghz_capa = *he_6ghz_capa;
 }
 
+static void ieee80211_he_mcs_disable(__le16 *he_mcs)
+{
+	u32 i;
+
+	for (i = 0; i < 8; i++)
+		*he_mcs |= cpu_to_le16(IEEE80211_HE_MCS_NOT_SUPPORTED << i * 2);
+}
+
+static void ieee80211_he_mcs_intersection(__le16 *he_own_rx, __le16 *he_peer_rx,
+					  __le16 *he_own_tx, __le16 *he_peer_tx)
+{
+	u32 i;
+	u16 own_rx, own_tx, peer_rx, peer_tx;
+
+	for (i = 0; i < 8; i++) {
+		own_rx = le16_to_cpu(*he_own_rx);
+		own_rx = (own_rx >> i * 2) & IEEE80211_HE_MCS_NOT_SUPPORTED;
+
+		own_tx = le16_to_cpu(*he_own_tx);
+		own_tx = (own_tx >> i * 2) & IEEE80211_HE_MCS_NOT_SUPPORTED;
+
+		peer_rx = le16_to_cpu(*he_peer_rx);
+		peer_rx = (peer_rx >> i * 2) & IEEE80211_HE_MCS_NOT_SUPPORTED;
+
+		peer_tx = le16_to_cpu(*he_peer_tx);
+		peer_tx = (peer_tx >> i * 2) & IEEE80211_HE_MCS_NOT_SUPPORTED;
+
+		if (peer_tx != IEEE80211_HE_MCS_NOT_SUPPORTED) {
+			if (own_rx == IEEE80211_HE_MCS_NOT_SUPPORTED)
+				peer_tx = IEEE80211_HE_MCS_NOT_SUPPORTED;
+			else if (own_rx < peer_tx)
+				peer_tx = own_rx;
+		}
+
+		if (peer_rx != IEEE80211_HE_MCS_NOT_SUPPORTED) {
+			if (own_tx == IEEE80211_HE_MCS_NOT_SUPPORTED)
+				peer_rx = IEEE80211_HE_MCS_NOT_SUPPORTED;
+			else if (own_tx < peer_rx)
+				peer_rx = own_tx;
+		}
+
+		*he_peer_rx &=
+			~cpu_to_le16(IEEE80211_HE_MCS_NOT_SUPPORTED << i * 2);
+		*he_peer_rx |= cpu_to_le16(peer_rx << i * 2);
+
+		*he_peer_tx &=
+			~cpu_to_le16(IEEE80211_HE_MCS_NOT_SUPPORTED << i * 2);
+		*he_peer_tx |= cpu_to_le16(peer_tx << i * 2);
+	}
+}
+
 void
 ieee80211_he_cap_ie_to_sta_he_cap(struct ieee80211_sub_if_data *sdata,
 				  struct ieee80211_supported_band *sband,
@@ -60,10 +111,12 @@ ieee80211_he_cap_ie_to_sta_he_cap(struct ieee80211_sub_if_data *sdata,
 				  struct sta_info *sta)
 {
 	struct ieee80211_sta_he_cap *he_cap = &sta->sta.he_cap;
+	struct ieee80211_sta_he_cap own_he_cap = sband->iftype_data->he_cap;
 	struct ieee80211_he_cap_elem *he_cap_ie_elem = (void *)he_cap_ie;
 	u8 he_ppe_size;
 	u8 mcs_nss_size;
 	u8 he_total_size;
+	bool own_160, peer_160, own_80p80, peer_80p80;
 
 	memset(he_cap, 0, sizeof(*he_cap));
 
@@ -101,6 +154,45 @@ ieee80211_he_cap_ie_to_sta_he_cap(struct ieee80211_sub_if_data *sdata,
 
 	if (sband->band == NL80211_BAND_6GHZ && he_6ghz_capa)
 		ieee80211_update_from_he_6ghz_capa(he_6ghz_capa, sta);
+
+	ieee80211_he_mcs_intersection(&own_he_cap.he_mcs_nss_supp.rx_mcs_80,
+				      &he_cap->he_mcs_nss_supp.rx_mcs_80,
+				      &own_he_cap.he_mcs_nss_supp.tx_mcs_80,
+				      &he_cap->he_mcs_nss_supp.tx_mcs_80);
+
+	own_160 = own_he_cap.he_cap_elem.phy_cap_info[0] &
+		  IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_160MHZ_IN_5G;
+	peer_160 = he_cap->he_cap_elem.phy_cap_info[0] &
+		   IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_160MHZ_IN_5G;
+
+	if (peer_160 && own_160) {
+		ieee80211_he_mcs_intersection(&own_he_cap.he_mcs_nss_supp.rx_mcs_160,
+					      &he_cap->he_mcs_nss_supp.rx_mcs_160,
+					      &own_he_cap.he_mcs_nss_supp.tx_mcs_160,
+					      &he_cap->he_mcs_nss_supp.tx_mcs_160);
+	} else if (peer_160 && !own_160) {
+		ieee80211_he_mcs_disable(&he_cap->he_mcs_nss_supp.rx_mcs_160);
+		ieee80211_he_mcs_disable(&he_cap->he_mcs_nss_supp.tx_mcs_160);
+		he_cap->he_cap_elem.phy_cap_info[0] &=
+			~IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_160MHZ_IN_5G;
+	}
+
+	own_80p80 = own_he_cap.he_cap_elem.phy_cap_info[0] &
+		    IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_80PLUS80_MHZ_IN_5G;
+	peer_80p80 = he_cap->he_cap_elem.phy_cap_info[0] &
+		     IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_80PLUS80_MHZ_IN_5G;
+
+	if (peer_80p80 && own_80p80) {
+		ieee80211_he_mcs_intersection(&own_he_cap.he_mcs_nss_supp.rx_mcs_80p80,
+					      &he_cap->he_mcs_nss_supp.rx_mcs_80p80,
+					      &own_he_cap.he_mcs_nss_supp.tx_mcs_80p80,
+					      &he_cap->he_mcs_nss_supp.tx_mcs_80p80);
+	} else if (peer_80p80 && !own_80p80) {
+		ieee80211_he_mcs_disable(&he_cap->he_mcs_nss_supp.rx_mcs_80p80);
+		ieee80211_he_mcs_disable(&he_cap->he_mcs_nss_supp.tx_mcs_80p80);
+		he_cap->he_cap_elem.phy_cap_info[0] &=
+			~IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_80PLUS80_MHZ_IN_5G;
+	}
 }
 
 void