wifi: mac80211: introduce 'channel request'

For channel contexts, mac80211 currently uses the cfg80211
chandef struct (control channel, center freq(s), width) to
define towards drivers and internally how these behave. In
fact, there are _two_ such structs used, where the min_def
can reduce bandwidth according to the stations connected.

Unfortunately,  with EHT this is longer be sufficient,  at
least not for all hardware.  EHT requires that non-AP STAs
that are connected to an AP with a lower bandwidth than it
(the AP) advertises (e.g. 160 MHz STA connected to 320 MHz
AP) still be able to receive downlink OFDMA and respond to
trigger frames for uplink OFDMA  that specify the position
and bandwidth  for the non-AP STA  relative to the channel
the AP is using.  Therefore, they need to be aware of this,
and at least for some hardware (e.g. Intel) this awareness
is in the hardware. As a result, use of the "same" channel
may need to be split over  two channel contexts where they
differ by the AP being used.

As a first step,  introduce a concept of a channel request
('chanreq') for each interface,  to control the context it
requests.   This step does nothing but reorganise the code,
so that later the AP's chandef can be added to the request
in order to handle the EHT case described above.

Link: https://msgid.link/20240129194108.2e88e48bd2e9.I4256183debe975c5ed71621611206fdbb69ba330@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 18 insertions, 18 deletions

diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index c23f46218af7..27cc9ddd0432 100644
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -223,7 +223,7 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 	struct ieee80211_mgmt *mgmt;
 	struct cfg80211_bss *bss;
 	u64 bss_change;
-	struct cfg80211_chan_def chandef;
+	struct ieee80211_chan_req chanreq = {};
 	struct ieee80211_channel *chan;
 	struct beacon_data *presp;
 	struct cfg80211_inform_bss bss_meta = {};
@@ -257,22 +257,22 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 		kfree_rcu(presp, rcu_head);
 
 	/* make a copy of the chandef, it could be modified below. */
-	chandef = *req_chandef;
-	chan = chandef.chan;
-	if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef,
+	chanreq.oper = *req_chandef;
+	chan = chanreq.oper.chan;
+	if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chanreq.oper,
 				     NL80211_IFTYPE_ADHOC)) {
-		if (chandef.width == NL80211_CHAN_WIDTH_5 ||
-		    chandef.width == NL80211_CHAN_WIDTH_10 ||
-		    chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
-		    chandef.width == NL80211_CHAN_WIDTH_20) {
+		if (chanreq.oper.width == NL80211_CHAN_WIDTH_5 ||
+		    chanreq.oper.width == NL80211_CHAN_WIDTH_10 ||
+		    chanreq.oper.width == NL80211_CHAN_WIDTH_20_NOHT ||
+		    chanreq.oper.width == NL80211_CHAN_WIDTH_20) {
 			sdata_info(sdata,
 				   "Failed to join IBSS, beacons forbidden\n");
 			return;
 		}
-		chandef.width = NL80211_CHAN_WIDTH_20;
-		chandef.center_freq1 = chan->center_freq;
+		chanreq.oper.width = NL80211_CHAN_WIDTH_20;
+		chanreq.oper.center_freq1 = chan->center_freq;
 		/* check again for downgraded chandef */
-		if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef,
+		if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chanreq.oper,
 					     NL80211_IFTYPE_ADHOC)) {
 			sdata_info(sdata,
 				   "Failed to join IBSS, beacons forbidden\n");
@@ -281,7 +281,7 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 	}
 
 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
-					    &chandef, NL80211_IFTYPE_ADHOC);
+					    &chanreq.oper, NL80211_IFTYPE_ADHOC);
 	if (err < 0) {
 		sdata_info(sdata,
 			   "Failed to join IBSS, invalid chandef\n");
@@ -295,7 +295,7 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 
 	radar_required = err;
 
-	if (ieee80211_link_use_channel(&sdata->deflink, &chandef,
+	if (ieee80211_link_use_channel(&sdata->deflink, &chanreq,
 				       ifibss->fixed_channel ?
 					IEEE80211_CHANCTX_SHARED :
 					IEEE80211_CHANCTX_EXCLUSIVE)) {
@@ -307,7 +307,7 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 	memcpy(ifibss->bssid, bssid, ETH_ALEN);
 
 	presp = ieee80211_ibss_build_presp(sdata, beacon_int, basic_rates,
-					   capability, tsf, &chandef,
+					   capability, tsf, &chanreq.oper,
 					   &have_higher_than_11mbit, NULL);
 	if (!presp)
 		return;
@@ -533,12 +533,12 @@ int ieee80211_ibss_finish_csa(struct ieee80211_sub_if_data *sdata, u64 *changed)
 					IEEE80211_PRIVACY(ifibss->privacy));
 		/* XXX: should not really modify cfg80211 data */
 		if (cbss) {
-			cbss->channel = sdata->deflink.csa_chandef.chan;
+			cbss->channel = sdata->deflink.csa_chanreq.oper.chan;
 			cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
 		}
 	}
 
-	ifibss->chandef = sdata->deflink.csa_chandef;
+	ifibss->chandef = sdata->deflink.csa_chanreq.oper;
 
 	/* generate the beacon */
 	return ieee80211_ibss_csa_beacon(sdata, NULL, changed);
@@ -799,7 +799,7 @@ ieee80211_ibss_process_chanswitch(struct ieee80211_sub_if_data *sdata,
 		goto disconnect;
 
 	params.count = csa_ie.count;
-	params.chandef = csa_ie.chandef;
+	params.chandef = csa_ie.chanreq.oper;
 
 	switch (ifibss->chandef.width) {
 	case NL80211_CHAN_WIDTH_20_NOHT:
@@ -858,7 +858,7 @@ ieee80211_ibss_process_chanswitch(struct ieee80211_sub_if_data *sdata,
 	params.radar_required = err;
 
 	if (cfg80211_chandef_identical(&params.chandef,
-				       &sdata->vif.bss_conf.chandef)) {
+				       &sdata->vif.bss_conf.chanreq.oper)) {
 		ibss_dbg(sdata,
 			 "received csa with an identical chandef, ignoring\n");
 		return true;