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, 38 insertions, 28 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index d3bf029709d5..5aa02b0872d9 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -886,11 +886,13 @@ static int ieee80211_set_monitor_channel(struct wiphy *wiphy,
 {
 	struct ieee80211_local *local = wiphy_priv(wiphy);
 	struct ieee80211_sub_if_data *sdata;
+	struct ieee80211_chan_req chanreq = { .oper = *chandef };
 	int ret;
 
 	lockdep_assert_wiphy(local->hw.wiphy);
 
-	if (cfg80211_chandef_identical(&local->monitor_chandef, chandef))
+	if (cfg80211_chandef_identical(&local->monitor_chanreq.oper,
+				       &chanreq.oper))
 		return 0;
 
 	sdata = wiphy_dereference(local->hw.wiphy,
@@ -898,17 +900,17 @@ static int ieee80211_set_monitor_channel(struct wiphy *wiphy,
 	if (!sdata)
 		goto done;
 
-	if (cfg80211_chandef_identical(&sdata->vif.bss_conf.chandef, chandef))
+	if (cfg80211_chandef_identical(&sdata->vif.bss_conf.chanreq.oper,
+				       &chanreq.oper))
 		return 0;
 
 	ieee80211_link_release_channel(&sdata->deflink);
-	ret = ieee80211_link_use_channel(&sdata->deflink,
-					 chandef,
+	ret = ieee80211_link_use_channel(&sdata->deflink, &chanreq,
 					 IEEE80211_CHANCTX_EXCLUSIVE);
 	if (ret)
 		return ret;
 done:
-	local->monitor_chandef = *chandef;
+	local->monitor_chanreq = chanreq;
 	return 0;
 }
 
@@ -1257,6 +1259,7 @@ static int ieee80211_start_ap(struct wiphy *wiphy, struct net_device *dev,
 	unsigned int link_id = params->beacon.link_id;
 	struct ieee80211_link_data *link;
 	struct ieee80211_bss_conf *link_conf;
+	struct ieee80211_chan_req chanreq = { .oper = params->chandef };
 
 	lockdep_assert_wiphy(local->hw.wiphy);
 
@@ -1369,7 +1372,7 @@ static int ieee80211_start_ap(struct wiphy *wiphy, struct net_device *dev,
 			return err;
 	}
 
-	err = ieee80211_link_use_channel(link, &params->chandef,
+	err = ieee80211_link_use_channel(link, &chanreq,
 					 IEEE80211_CHANCTX_SHARED);
 	if (!err)
 		ieee80211_link_copy_chanctx_to_vlans(link, false);
@@ -1626,7 +1629,7 @@ static int ieee80211_stop_ap(struct wiphy *wiphy, struct net_device *dev,
 					  BSS_CHANGED_BEACON_ENABLED);
 
 	if (sdata->wdev.cac_started) {
-		chandef = link_conf->chandef;
+		chandef = link_conf->chanreq.oper;
 		wiphy_delayed_work_cancel(wiphy, &link->dfs_cac_timer_work);
 		cfg80211_cac_event(sdata->dev, &chandef,
 				   NL80211_RADAR_CAC_ABORTED,
@@ -1826,7 +1829,7 @@ static int sta_link_apply_parameters(struct ieee80211_local *local,
 
 	if (params->supported_rates &&
 	    params->supported_rates_len) {
-		ieee80211_parse_bitrates(link->conf->chandef.width,
+		ieee80211_parse_bitrates(link->conf->chanreq.oper.width,
 					 sband, params->supported_rates,
 					 params->supported_rates_len,
 					 &link_sta->pub->supp_rates[sband->band]);
@@ -2602,6 +2605,7 @@ static int ieee80211_join_mesh(struct wiphy *wiphy, struct net_device *dev,
 			       const struct mesh_setup *setup)
 {
 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+	struct ieee80211_chan_req chanreq = { .oper = setup->chandef };
 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 	int err;
 
@@ -2618,7 +2622,7 @@ static int ieee80211_join_mesh(struct wiphy *wiphy, struct net_device *dev,
 	sdata->deflink.smps_mode = IEEE80211_SMPS_OFF;
 	sdata->deflink.needed_rx_chains = sdata->local->rx_chains;
 
-	err = ieee80211_link_use_channel(&sdata->deflink, &setup->chandef,
+	err = ieee80211_link_use_channel(&sdata->deflink, &chanreq,
 					 IEEE80211_CHANCTX_SHARED);
 	if (err)
 		return err;
@@ -2661,7 +2665,7 @@ static int ieee80211_change_bss(struct wiphy *wiphy,
 		return -EINVAL;
 
 	if (params->basic_rates) {
-		if (!ieee80211_parse_bitrates(link->conf->chandef.width,
+		if (!ieee80211_parse_bitrates(link->conf->chanreq.oper.width,
 					      wiphy->bands[sband->band],
 					      params->basic_rates,
 					      params->basic_rates_len,
@@ -3176,7 +3180,7 @@ int __ieee80211_request_smps_mgd(struct ieee80211_sub_if_data *sdata,
 	 * the new value until we associate.
 	 */
 	if (!sdata->u.mgd.associated ||
-	    link->conf->chandef.width == NL80211_CHAN_WIDTH_20_NOHT)
+	    link->conf->chanreq.oper.width == NL80211_CHAN_WIDTH_20_NOHT)
 		return 0;
 
 	ap = sdata->vif.cfg.ap_addr;
@@ -3331,9 +3335,11 @@ static int ieee80211_set_bitrate_mask(struct wiphy *wiphy,
 	 * so at a basic rate so that all clients can receive it.
 	 */
 	if (rcu_access_pointer(sdata->vif.bss_conf.chanctx_conf) &&
-	    sdata->vif.bss_conf.chandef.chan) {
+	    sdata->vif.bss_conf.chanreq.oper.chan) {
 		u32 basic_rates = sdata->vif.bss_conf.basic_rates;
-		enum nl80211_band band = sdata->vif.bss_conf.chandef.chan->band;
+		enum nl80211_band band;
+
+		band = sdata->vif.bss_conf.chanreq.oper.chan->band;
 
 		if (!(mask->control[band].legacy & basic_rates))
 			return -EINVAL;
@@ -3385,6 +3391,7 @@ static int ieee80211_start_radar_detection(struct wiphy *wiphy,
 					   u32 cac_time_ms)
 {
 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+	struct ieee80211_chan_req chanreq = { .oper = *chandef };
 	struct ieee80211_local *local = sdata->local;
 	int err;
 
@@ -3399,7 +3406,7 @@ static int ieee80211_start_radar_detection(struct wiphy *wiphy,
 	sdata->deflink.smps_mode = IEEE80211_SMPS_OFF;
 	sdata->deflink.needed_rx_chains = local->rx_chains;
 
-	err = ieee80211_link_use_channel(&sdata->deflink, chandef,
+	err = ieee80211_link_use_channel(&sdata->deflink, &chanreq,
 					 IEEE80211_CHANCTX_SHARED);
 	if (err)
 		goto out_unlock;
@@ -3651,8 +3658,8 @@ static int __ieee80211_csa_finalize(struct ieee80211_link_data *link_data)
 		return ieee80211_link_use_reserved_context(&sdata->deflink);
 	}
 
-	if (!cfg80211_chandef_identical(&link_data->conf->chandef,
-					&link_data->csa_chandef))
+	if (!cfg80211_chandef_identical(&link_data->conf->chanreq.oper,
+					&link_data->csa_chanreq.oper))
 		return -EINVAL;
 
 	sdata->vif.bss_conf.csa_active = false;
@@ -3679,7 +3686,7 @@ static int __ieee80211_csa_finalize(struct ieee80211_link_data *link_data)
 	if (err)
 		return err;
 
-	cfg80211_ch_switch_notify(sdata->dev, &link_data->csa_chandef,
+	cfg80211_ch_switch_notify(sdata->dev, &link_data->csa_chanreq.oper,
 				  link_data->link_id,
 				  link_data->conf->eht_puncturing);
 
@@ -3814,7 +3821,7 @@ static int ieee80211_set_csa_beacon(struct ieee80211_sub_if_data *sdata,
 		struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 
 		/* changes into another band are not supported */
-		if (sdata->vif.bss_conf.chandef.chan->band !=
+		if (sdata->vif.bss_conf.chanreq.oper.chan->band !=
 		    params->chandef.chan->band)
 			return -EINVAL;
 
@@ -3862,6 +3869,7 @@ __ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev,
 			   struct cfg80211_csa_settings *params)
 {
 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+	struct ieee80211_chan_req chanreq = { .oper = params->chandef };
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_channel_switch ch_switch;
 	struct ieee80211_chanctx_conf *conf;
@@ -3877,8 +3885,8 @@ __ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev,
 	if (sdata->wdev.cac_started)
 		return -EBUSY;
 
-	if (cfg80211_chandef_identical(&params->chandef,
-				       &sdata->vif.bss_conf.chandef))
+	if (cfg80211_chandef_identical(&chanreq.oper,
+				       &sdata->vif.bss_conf.chanreq.oper))
 		return -EINVAL;
 
 	/* don't allow another channel switch if one is already active. */
@@ -3903,14 +3911,14 @@ __ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev,
 	ch_switch.timestamp = 0;
 	ch_switch.device_timestamp = 0;
 	ch_switch.block_tx = params->block_tx;
-	ch_switch.chandef = params->chandef;
+	ch_switch.chandef = chanreq.oper;
 	ch_switch.count = params->count;
 
 	err = drv_pre_channel_switch(sdata, &ch_switch);
 	if (err)
 		goto out;
 
-	err = ieee80211_link_reserve_chanctx(&sdata->deflink, &params->chandef,
+	err = ieee80211_link_reserve_chanctx(&sdata->deflink, &chanreq,
 					     chanctx->mode,
 					     params->radar_required);
 	if (err)
@@ -3936,7 +3944,7 @@ __ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev,
 	if (params->punct_bitmap && !sdata->vif.bss_conf.eht_support)
 		goto out;
 
-	sdata->deflink.csa_chandef = params->chandef;
+	sdata->deflink.csa_chanreq = chanreq; 
 	sdata->deflink.csa_block_tx = params->block_tx;
 	sdata->vif.bss_conf.csa_active = true;
 	sdata->vif.bss_conf.csa_punct_bitmap = params->punct_bitmap;
@@ -3946,14 +3954,15 @@ __ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev,
 					  IEEE80211_QUEUE_STOP_REASON_CSA);
 
 	cfg80211_ch_switch_started_notify(sdata->dev,
-					  &sdata->deflink.csa_chandef, 0,
+					  &sdata->deflink.csa_chanreq.oper, 0,
 					  params->count, params->block_tx,
 					  sdata->vif.bss_conf.csa_punct_bitmap);
 
 	if (changed) {
 		ieee80211_link_info_change_notify(sdata, &sdata->deflink,
 						  changed);
-		drv_channel_switch_beacon(sdata, &params->chandef);
+		drv_channel_switch_beacon(sdata,
+					  &sdata->deflink.csa_chanreq.oper);
 	} else {
 		/* if the beacon didn't change, we can finalize immediately */
 		ieee80211_csa_finalize(&sdata->deflink);
@@ -4206,12 +4215,12 @@ static int ieee80211_cfg_get_channel(struct wiphy *wiphy,
 
 	chanctx_conf = rcu_dereference(link->conf->chanctx_conf);
 	if (chanctx_conf) {
-		*chandef = link->conf->chandef;
+		*chandef = link->conf->chanreq.oper;
 		ret = 0;
 	} else if (local->open_count > 0 &&
 		   local->open_count == local->monitors &&
 		   sdata->vif.type == NL80211_IFTYPE_MONITOR) {
-		*chandef = local->monitor_chandef;
+		*chandef = local->monitor_chanreq.oper;
 		ret = 0;
 	}
 out:
@@ -4259,12 +4268,13 @@ static int ieee80211_set_ap_chanwidth(struct wiphy *wiphy,
 {
 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 	struct ieee80211_link_data *link;
+	struct ieee80211_chan_req chanreq = { .oper = *chandef };
 	int ret;
 	u64 changed = 0;
 
 	link = sdata_dereference(sdata->link[link_id], sdata);
 
-	ret = ieee80211_link_change_bandwidth(link, chandef, &changed);
+	ret = ieee80211_link_change_chanreq(link, &chanreq, &changed);
 	if (ret == 0)
 		ieee80211_link_info_change_notify(sdata, link, changed);