wifi: mac80211: add a flag to disallow puncturing

There may be cases where puncturing isn't possible, and
a connection needs to be downgraded. Add a hardware flag
to support this.

This is likely temporary: it seems we will need to move
puncturing to the chandef/channel context.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Gregory Greenman <gregory.greenman@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20231211085121.c1e89ea55e93.I37b8ca0ee64d5d7699e351785a9010afc106da3c@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/mac80211.h

@@ -2686,6 +2686,9 @@ struct ieee80211_txq {
  * @IEEE80211_HW_MLO_MCAST_MULTI_LINK_TX: Hardware/driver handles transmitting
  *	multicast frames on all links, mac80211 should not do that.
  *
+ * @IEEE80211_HW_DISALLOW_PUNCTURING: HW requires disabling puncturing in EHT
+ *	and connecting with a lower bandwidth instead
+ *
  * @NUM_IEEE80211_HW_FLAGS: number of hardware flags, used for sizing arrays
  */
 enum ieee80211_hw_flags {
@@ -2743,6 +2746,7 @@ enum ieee80211_hw_flags {
 	IEEE80211_HW_SUPPORTS_CONC_MON_RX_DECAP,
 	IEEE80211_HW_DETECTS_COLOR_COLLISION,
 	IEEE80211_HW_MLO_MCAST_MULTI_LINK_TX,
+	IEEE80211_HW_DISALLOW_PUNCTURING,
 
 	/* keep last, obviously */
 	NUM_IEEE80211_HW_FLAGS

net/mac80211/debugfs.c

@@ -497,6 +497,7 @@ static const char *hw_flag_names[] = {
 	FLAG(SUPPORTS_CONC_MON_RX_DECAP),
 	FLAG(DETECTS_COLOR_COLLISION),
 	FLAG(MLO_MCAST_MULTI_LINK_TX),
+	FLAG(DISALLOW_PUNCTURING),
 #undef FLAG
 };
 

net/mac80211/mlme.c

@@ -135,6 +135,7 @@ ieee80211_handle_puncturing_bitmap(struct ieee80211_link_data *link,
 				   u16 bitmap, u64 *changed)
 {
 	struct cfg80211_chan_def *chandef = &link->conf->chandef;
+	struct ieee80211_local *local = link->sdata->local;
 	u16 extracted;
 	u64 _changed = 0;
 
@@ -147,7 +148,9 @@ ieee80211_handle_puncturing_bitmap(struct ieee80211_link_data *link,
 							 bitmap);
 
 		if (cfg80211_valid_disable_subchannel_bitmap(&bitmap,
-							     chandef))
+							     chandef) &&
+		    !(bitmap && ieee80211_hw_check(&local->hw,
+						   DISALLOW_PUNCTURING)))
 			break;
 		link->u.mgd.conn_flags |=
 			ieee80211_chandef_downgrade(chandef);
@@ -5682,6 +5685,7 @@ static bool ieee80211_config_puncturing(struct ieee80211_link_data *link,
 					const struct ieee80211_eht_operation *eht_oper,
 					u64 *changed)
 {
+	struct ieee80211_local *local = link->sdata->local;
 	u16 bitmap = 0, extracted;
 
 	if ((eht_oper->params & IEEE80211_EHT_OPER_INFO_PRESENT) &&
@@ -5713,6 +5717,9 @@ static bool ieee80211_config_puncturing(struct ieee80211_link_data *link,
 		return false;
 	}
 
+	if (bitmap && ieee80211_hw_check(&local->hw, DISALLOW_PUNCTURING))
+		return false;
+
 	ieee80211_handle_puncturing_bitmap(link, eht_oper, bitmap, changed);
 	return true;
 }
@@ -7584,7 +7591,8 @@ ieee80211_setup_assoc_link(struct ieee80211_sub_if_data *sdata,
 
 			bitmap = get_unaligned_le16(disable_subchannel_bitmap);
 			if (cfg80211_valid_disable_subchannel_bitmap(&bitmap,
-								     &link->conf->chandef))
+								     &link->conf->chandef) &&
+			    !(bitmap && ieee80211_hw_check(&local->hw, DISALLOW_PUNCTURING)))
 				ieee80211_handle_puncturing_bitmap(link,
 								   eht_oper,
 								   bitmap,