wifi: mac80211: simplify non-chanctx drivers

There are still surprisingly many non-chanctx drivers, but in
mac80211 that code is a bit awkward. Simplify this by having
those drivers assign 'emulated' ops, so that the mac80211 code
can be more unified between non-chanctx/chanctx drivers. This
cuts the number of places caring about it by about 15, which
are scattered across - now they're fewer and no longer in the
channel context handling.

Link: https://msgid.link/20240129194108.6d0ead50f5cf.I60d093b2fc81ca1853925a4d0ac3a2337d5baa5b@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

10 files changed, 243 insertions, 201 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 6e2acad7fd715..d3bf029709d54 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -886,33 +886,30 @@ static int ieee80211_set_monitor_channel(struct wiphy *wiphy,
 {
 	struct ieee80211_local *local = wiphy_priv(wiphy);
 	struct ieee80211_sub_if_data *sdata;
-	int ret = 0;
+	int ret;
 
 	lockdep_assert_wiphy(local->hw.wiphy);
 
 	if (cfg80211_chandef_identical(&local->monitor_chandef, chandef))
 		return 0;
 
-	if (local->use_chanctx) {
-		sdata = wiphy_dereference(local->hw.wiphy,
-					  local->monitor_sdata);
-		if (sdata) {
-			ieee80211_link_release_channel(&sdata->deflink);
-			ret = ieee80211_link_use_channel(&sdata->deflink,
-							 chandef,
-							 IEEE80211_CHANCTX_EXCLUSIVE);
-		}
-	} else {
-		if (local->open_count == local->monitors) {
-			local->_oper_chandef = *chandef;
-			ieee80211_hw_config(local, 0);
-		}
-	}
+	sdata = wiphy_dereference(local->hw.wiphy,
+				  local->monitor_sdata);
+	if (!sdata)
+		goto done;
 
-	if (ret == 0)
-		local->monitor_chandef = *chandef;
+	if (cfg80211_chandef_identical(&sdata->vif.bss_conf.chandef, chandef))
+		return 0;
 
-	return ret;
+	ieee80211_link_release_channel(&sdata->deflink);
+	ret = ieee80211_link_use_channel(&sdata->deflink,
+					 chandef,
+					 IEEE80211_CHANCTX_EXCLUSIVE);
+	if (ret)
+		return ret;
+done:
+	local->monitor_chandef = *chandef;
+	return 0;
 }
 
 static int
@@ -3086,7 +3083,7 @@ static int ieee80211_get_tx_power(struct wiphy *wiphy,
 	if (local->ops->get_txpower)
 		return drv_get_txpower(local, sdata, dbm);
 
-	if (!local->use_chanctx)
+	if (local->emulate_chanctx)
 		*dbm = local->hw.conf.power_level;
 	else
 		*dbm = sdata->vif.bss_conf.txpower;
@@ -4214,10 +4211,7 @@ static int ieee80211_cfg_get_channel(struct wiphy *wiphy,
 	} else if (local->open_count > 0 &&
 		   local->open_count == local->monitors &&
 		   sdata->vif.type == NL80211_IFTYPE_MONITOR) {
-		if (local->use_chanctx)
-			*chandef = local->monitor_chandef;
-		else
-			*chandef = local->_oper_chandef;
+		*chandef = local->monitor_chandef;
 		ret = 0;
 	}
 out:
diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index 70ba5dc4b2837..cf6297ffaef32 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -519,11 +519,6 @@ static void _ieee80211_change_chanctx(struct ieee80211_local *local,
 
 	drv_change_chanctx(local, ctx, changed);
 
-	if (!local->use_chanctx) {
-		local->_oper_chandef = *chandef;
-		ieee80211_hw_config(local, 0);
-	}
-
 	/* check is BW wider */
 	ieee80211_chan_bw_change(local, old_ctx, false);
 }
@@ -674,23 +669,15 @@ static int ieee80211_add_chanctx(struct ieee80211_local *local,
 
 	ieee80211_add_wbrf(local, &ctx->conf.def);
 
-	if (!local->use_chanctx)
-		local->hw.conf.radar_enabled = ctx->conf.radar_enabled;
-
 	/* turn idle off *before* setting channel -- some drivers need that */
 	changed = ieee80211_idle_off(local);
 	if (changed)
 		ieee80211_hw_config(local, changed);
 
-	if (!local->use_chanctx) {
-		local->_oper_chandef = ctx->conf.def;
-		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
-	} else {
-		err = drv_add_chanctx(local, ctx);
-		if (err) {
-			ieee80211_recalc_idle(local);
-			return err;
-		}
+	err = drv_add_chanctx(local, ctx);
+	if (err) {
+		ieee80211_recalc_idle(local);
+		return err;
 	}
 
 	return 0;
@@ -725,32 +712,7 @@ static void ieee80211_del_chanctx(struct ieee80211_local *local,
 {
 	lockdep_assert_wiphy(local->hw.wiphy);
 
-	if (!local->use_chanctx) {
-		struct cfg80211_chan_def *chandef = &local->_oper_chandef;
-		/* S1G doesn't have 20MHz, so get the correct width for the
-		 * current channel.
-		 */
-		if (chandef->chan->band == NL80211_BAND_S1GHZ)
-			chandef->width =
-				ieee80211_s1g_channel_width(chandef->chan);
-		else
-			chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
-		chandef->center_freq1 = chandef->chan->center_freq;
-		chandef->freq1_offset = chandef->chan->freq_offset;
-		chandef->center_freq2 = 0;
-
-		/* NOTE: Disabling radar is only valid here for
-		 * single channel context. To be sure, check it ...
-		 */
-		WARN_ON(local->hw.conf.radar_enabled &&
-			!list_empty(&local->chanctx_list));
-
-		local->hw.conf.radar_enabled = false;
-
-		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
-	} else {
-		drv_remove_chanctx(local, ctx);
-	}
+	drv_remove_chanctx(local, ctx);
 
 	ieee80211_recalc_idle(local);
 
@@ -849,11 +811,6 @@ static void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
 
 	chanctx->conf.radar_enabled = radar_enabled;
 
-	if (!local->use_chanctx) {
-		local->hw.conf.radar_enabled = chanctx->conf.radar_enabled;
-		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
-	}
-
 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
 }
 
@@ -995,16 +952,6 @@ void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
 
 	rcu_read_unlock();
 
-	if (!local->use_chanctx) {
-		if (rx_chains_static > 1)
-			local->smps_mode = IEEE80211_SMPS_OFF;
-		else if (rx_chains_dynamic > 1)
-			local->smps_mode = IEEE80211_SMPS_DYNAMIC;
-		else
-			local->smps_mode = IEEE80211_SMPS_STATIC;
-		ieee80211_hw_config(local, 0);
-	}
-
 	if (rx_chains_static == chanctx->conf.rx_chains_static &&
 	    rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
 		return;
@@ -1114,7 +1061,7 @@ int ieee80211_link_reserve_chanctx(struct ieee80211_link_data *link,
 	lockdep_assert_wiphy(local->hw.wiphy);
 
 	curr_ctx = ieee80211_link_get_chanctx(link);
-	if (curr_ctx && local->use_chanctx && !local->ops->switch_vif_chanctx)
+	if (curr_ctx && !local->ops->switch_vif_chanctx)
 		return -EOPNOTSUPP;
 
 	new_ctx = ieee80211_find_reservation_chanctx(local, chandef, mode);
@@ -1412,24 +1359,6 @@ ieee80211_link_has_in_place_reservation(struct ieee80211_link_data *link)
 	return true;
 }
 
-static int ieee80211_chsw_switch_hwconf(struct ieee80211_local *local,
-					struct ieee80211_chanctx *new_ctx)
-{
-	const struct cfg80211_chan_def *chandef;
-
-	lockdep_assert_wiphy(local->hw.wiphy);
-
-	chandef = ieee80211_chanctx_reserved_chandef(local, new_ctx, NULL);
-	if (WARN_ON(!chandef))
-		return -EINVAL;
-
-	local->hw.conf.radar_enabled = new_ctx->conf.radar_enabled;
-	local->_oper_chandef = *chandef;
-	ieee80211_hw_config(local, 0);
-
-	return 0;
-}
-
 static int ieee80211_chsw_switch_vifs(struct ieee80211_local *local,
 				      int n_vifs)
 {
@@ -1518,7 +1447,6 @@ err:
 static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
 {
 	struct ieee80211_chanctx *ctx, *ctx_tmp, *old_ctx;
-	struct ieee80211_chanctx *new_ctx = NULL;
 	int err, n_assigned, n_reserved, n_ready;
 	int n_ctx = 0, n_vifs_switch = 0, n_vifs_assign = 0, n_vifs_ctxless = 0;
 
@@ -1551,9 +1479,6 @@ static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
 			goto err;
 		}
 
-		if (!local->use_chanctx)
-			new_ctx = ctx;
-
 		n_ctx++;
 
 		n_assigned = 0;
@@ -1607,9 +1532,7 @@ static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
 	if (WARN_ON(n_ctx == 0) ||
 	    WARN_ON(n_vifs_switch == 0 &&
 		    n_vifs_assign == 0 &&
-		    n_vifs_ctxless == 0) ||
-	    WARN_ON(n_ctx > 1 && !local->use_chanctx) ||
-	    WARN_ON(!new_ctx && !local->use_chanctx)) {
+		    n_vifs_ctxless == 0)) {
 		err = -EINVAL;
 		goto err;
 	}
@@ -1619,20 +1542,14 @@ static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
 	 * reservations and driver capabilities.
 	 */
 
-	if (local->use_chanctx) {
-		if (n_vifs_switch > 0) {
-			err = ieee80211_chsw_switch_vifs(local, n_vifs_switch);
-			if (err)
-				goto err;
-		}
+	if (n_vifs_switch > 0) {
+		err = ieee80211_chsw_switch_vifs(local, n_vifs_switch);
+		if (err)
+			goto err;
+	}
 
-		if (n_vifs_assign > 0 || n_vifs_ctxless > 0) {
-			err = ieee80211_chsw_switch_ctxs(local);
-			if (err)
-				goto err;
-		}
-	} else {
-		err = ieee80211_chsw_switch_hwconf(local, new_ctx);
+	if (n_vifs_assign > 0 || n_vifs_ctxless > 0) {
+		err = ieee80211_chsw_switch_ctxs(local);
 		if (err)
 			goto err;
 	}
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 29294cf88d39c..cb4684a9451e4 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1348,7 +1348,8 @@ struct ieee80211_local {
 
 	bool wiphy_ciphers_allocated;
 
-	bool use_chanctx;
+	struct cfg80211_chan_def dflt_chandef;
+	bool emulate_chanctx;
 
 	/* protects the aggregated multicast list and filter calls */
 	spinlock_t filter_lock;
@@ -1474,8 +1475,6 @@ struct ieee80211_local {
 	enum mac80211_scan_state next_scan_state;
 	struct wiphy_delayed_work scan_work;
 	struct ieee80211_sub_if_data __rcu *scan_sdata;
-	/* For backward compatibility only -- do not use */
-	struct cfg80211_chan_def _oper_chandef;
 
 	/* Temporary remain-on-channel for off-channel operations */
 	struct ieee80211_channel *tmp_channel;
@@ -1549,8 +1548,6 @@ struct ieee80211_local {
 
 	int user_power_level; /* in dBm, for all interfaces */
 
-	enum ieee80211_smps_mode smps_mode;
-
 	struct work_struct restart_work;
 
 #ifdef CONFIG_MAC80211_DEBUGFS
@@ -1819,6 +1816,8 @@ u64 ieee80211_calculate_rx_timestamp(struct ieee80211_local *local,
 				     unsigned int mpdu_len,
 				     unsigned int mpdu_offset);
 int ieee80211_hw_config(struct ieee80211_local *local, u32 changed);
+int ieee80211_hw_conf_chan(struct ieee80211_local *local);
+void ieee80211_hw_conf_init(struct ieee80211_local *local);
 void ieee80211_tx_set_protected(struct ieee80211_tx_data *tx);
 void ieee80211_bss_info_change_notify(struct ieee80211_sub_if_data *sdata,
 				      u64 changed);
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 1a6e9dd39a375..d81162bf7d48b 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -1288,8 +1288,6 @@ int ieee80211_do_open(struct wireless_dev *wdev, bool coming_up)
 		res = drv_start(local);
 		if (res)
 			goto err_del_bss;
-		/* we're brought up, everything changes */
-		hw_reconf_flags = ~0;
 		ieee80211_led_radio(local, true);
 		ieee80211_mod_tpt_led_trig(local,
 					   IEEE80211_TPT_LEDTRIG_FL_RADIO, 0);
@@ -1436,7 +1434,9 @@ int ieee80211_do_open(struct wireless_dev *wdev, bool coming_up)
 	if (coming_up)
 		local->open_count++;
 
-	if (hw_reconf_flags)
+	if (local->open_count == 1)
+		ieee80211_hw_conf_init(local);
+	else if (hw_reconf_flags)
 		ieee80211_hw_config(local, hw_reconf_flags);
 
 	ieee80211_recalc_ps(local);
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index e05bcc35bc1e0..ce0cba8d7afc0 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -93,16 +93,32 @@ static void ieee80211_reconfig_filter(struct wiphy *wiphy,
 	ieee80211_configure_filter(local);
 }
 
-static u32 ieee80211_hw_conf_chan(struct ieee80211_local *local)
+static u32 ieee80211_calc_hw_conf_chan(struct ieee80211_local *local,
+				       struct ieee80211_chanctx_conf *ctx)
 {
 	struct ieee80211_sub_if_data *sdata;
 	struct cfg80211_chan_def chandef = {};
+	struct cfg80211_chan_def *oper = NULL;
+	enum ieee80211_smps_mode smps_mode = IEEE80211_SMPS_STATIC;
 	u32 changed = 0;
 	int power;
 	u32 offchannel_flag;
 
+	if (!local->emulate_chanctx)
+		return 0;
+
 	offchannel_flag = local->hw.conf.flags & IEEE80211_CONF_OFFCHANNEL;
 
+	if (ctx && !WARN_ON(!ctx->def.chan)) {
+		oper = &ctx->def;
+		if (ctx->rx_chains_static > 1)
+			smps_mode = IEEE80211_SMPS_OFF;
+		else if (ctx->rx_chains_dynamic > 1)
+			smps_mode = IEEE80211_SMPS_DYNAMIC;
+		else
+			smps_mode = IEEE80211_SMPS_STATIC;
+	}
+
 	if (local->scan_chandef.chan) {
 		chandef = local->scan_chandef;
 	} else if (local->tmp_channel) {
@@ -110,25 +126,30 @@ static u32 ieee80211_hw_conf_chan(struct ieee80211_local *local)
 		chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
 		chandef.center_freq1 = chandef.chan->center_freq;
 		chandef.freq1_offset = chandef.chan->freq_offset;
-	} else
-		chandef = local->_oper_chandef;
+	} else if (oper) {
+		chandef = *oper;
+	} else {
+		chandef = local->dflt_chandef;
+	}
 
-	WARN(!cfg80211_chandef_valid(&chandef),
-	     "control:%d.%03d MHz width:%d center: %d.%03d/%d MHz",
-	     chandef.chan->center_freq, chandef.chan->freq_offset,
-	     chandef.width, chandef.center_freq1, chandef.freq1_offset,
-	     chandef.center_freq2);
+	if (WARN(!cfg80211_chandef_valid(&chandef),
+		 "control:%d.%03d MHz width:%d center: %d.%03d/%d MHz",
+		 chandef.chan ? chandef.chan->center_freq : -1,
+		 chandef.chan ? chandef.chan->freq_offset : 0,
+		 chandef.width, chandef.center_freq1, chandef.freq1_offset,
+		 chandef.center_freq2))
+		return 0;
 
-	if (!cfg80211_chandef_identical(&chandef, &local->_oper_chandef))
+	if (!oper || !cfg80211_chandef_identical(&chandef, oper))
 		local->hw.conf.flags |= IEEE80211_CONF_OFFCHANNEL;
 	else
 		local->hw.conf.flags &= ~IEEE80211_CONF_OFFCHANNEL;
 
 	offchannel_flag ^= local->hw.conf.flags & IEEE80211_CONF_OFFCHANNEL;
 
-	if (offchannel_flag ||
-	    !cfg80211_chandef_identical(&local->hw.conf.chandef,
-					&local->_oper_chandef)) {
+	/* force it also for scanning, since drivers might config differently */
+	if (offchannel_flag || local->scanning ||
+	    !cfg80211_chandef_identical(&local->hw.conf.chandef, &chandef)) {
 		local->hw.conf.chandef = chandef;
 		changed |= IEEE80211_CONF_CHANGE_CHANNEL;
 	}
@@ -140,8 +161,8 @@ static u32 ieee80211_hw_conf_chan(struct ieee80211_local *local)
 		 * that otherwise STATIC is used.
 		 */
 		local->hw.conf.smps_mode = IEEE80211_SMPS_STATIC;
-	} else if (local->hw.conf.smps_mode != local->smps_mode) {
-		local->hw.conf.smps_mode = local->smps_mode;
+	} else if (local->hw.conf.smps_mode != smps_mode) {
+		local->hw.conf.smps_mode = smps_mode;
 		changed |= IEEE80211_CONF_CHANGE_SMPS;
 	}
 
@@ -173,12 +194,9 @@ int ieee80211_hw_config(struct ieee80211_local *local, u32 changed)
 
 	might_sleep();
 
-	if (!local->use_chanctx)
-		changed |= ieee80211_hw_conf_chan(local);
-	else
-		changed &= ~(IEEE80211_CONF_CHANGE_CHANNEL |
-			     IEEE80211_CONF_CHANGE_POWER |
-			     IEEE80211_CONF_CHANGE_SMPS);
+	WARN_ON(changed & (IEEE80211_CONF_CHANGE_CHANNEL |
+			   IEEE80211_CONF_CHANGE_POWER |
+			   IEEE80211_CONF_CHANGE_SMPS));
 
 	if (changed && local->open_count) {
 		ret = drv_config(local, changed);
@@ -202,6 +220,107 @@ int ieee80211_hw_config(struct ieee80211_local *local, u32 changed)
 	return ret;
 }
 
+/* for scanning, offchannel and chanctx emulation only */
+static int _ieee80211_hw_conf_chan(struct ieee80211_local *local,
+				   struct ieee80211_chanctx_conf *ctx)
+{
+	u32 changed;
+
+	if (!local->open_count)
+		return 0;
+
+	changed = ieee80211_calc_hw_conf_chan(local, ctx);
+	if (!changed)
+		return 0;
+
+	return drv_config(local, changed);
+}
+
+int ieee80211_hw_conf_chan(struct ieee80211_local *local)
+{
+	struct ieee80211_chanctx *ctx;
+
+	ctx = list_first_entry_or_null(&local->chanctx_list,
+				       struct ieee80211_chanctx,
+				       list);
+
+	return _ieee80211_hw_conf_chan(local, ctx ? &ctx->conf : NULL);
+}
+
+void ieee80211_hw_conf_init(struct ieee80211_local *local)
+{
+	u32 changed = ~(IEEE80211_CONF_CHANGE_CHANNEL |
+			IEEE80211_CONF_CHANGE_POWER |
+			IEEE80211_CONF_CHANGE_SMPS);
+
+	if (WARN_ON(!local->open_count))
+		return;
+
+	if (local->emulate_chanctx) {
+		struct ieee80211_chanctx *ctx;
+
+		ctx = list_first_entry_or_null(&local->chanctx_list,
+					       struct ieee80211_chanctx,
+					       list);
+
+		changed |= ieee80211_calc_hw_conf_chan(local,
+						       ctx ? &ctx->conf : NULL);
+	}
+
+	WARN_ON(drv_config(local, changed));
+}
+
+int ieee80211_emulate_add_chanctx(struct ieee80211_hw *hw,
+				  struct ieee80211_chanctx_conf *ctx)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+
+	local->hw.conf.radar_enabled = ctx->radar_enabled;
+
+	return _ieee80211_hw_conf_chan(local, ctx);
+}
+EXPORT_SYMBOL(ieee80211_emulate_add_chanctx);
+
+void ieee80211_emulate_remove_chanctx(struct ieee80211_hw *hw,
+				      struct ieee80211_chanctx_conf *ctx)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+
+	local->hw.conf.radar_enabled = false;
+
+	_ieee80211_hw_conf_chan(local, NULL);
+}
+EXPORT_SYMBOL(ieee80211_emulate_remove_chanctx);
+
+void ieee80211_emulate_change_chanctx(struct ieee80211_hw *hw,
+				      struct ieee80211_chanctx_conf *ctx,
+				      u32 changed)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+
+	local->hw.conf.radar_enabled = ctx->radar_enabled;
+
+	_ieee80211_hw_conf_chan(local, ctx);
+}
+EXPORT_SYMBOL(ieee80211_emulate_change_chanctx);
+
+int ieee80211_emulate_switch_vif_chanctx(struct ieee80211_hw *hw,
+					 struct ieee80211_vif_chanctx_switch *vifs,
+					 int n_vifs,
+					 enum ieee80211_chanctx_switch_mode mode)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+
+	if (n_vifs <= 0)
+		return -EINVAL;
+
+	local->hw.conf.radar_enabled = vifs[0].new_ctx->radar_enabled;
+	_ieee80211_hw_conf_chan(local, vifs[0].new_ctx);
+
+	return 0;
+}
+EXPORT_SYMBOL(ieee80211_emulate_switch_vif_chanctx);
+
 #define BSS_CHANGED_VIF_CFG_FLAGS (BSS_CHANGED_ASSOC |\
 				   BSS_CHANGED_IDLE |\
 				   BSS_CHANGED_PS |\
@@ -645,7 +764,7 @@ struct ieee80211_hw *ieee80211_alloc_hw_nm(size_t priv_data_len,
 	struct ieee80211_local *local;
 	int priv_size, i;
 	struct wiphy *wiphy;
-	bool use_chanctx;
+	bool emulate_chanctx;
 
 	if (WARN_ON(!ops->tx || !ops->start || !ops->stop || !ops->config ||
 		    !ops->add_interface || !ops->remove_interface ||
@@ -660,12 +779,26 @@ struct ieee80211_hw *ieee80211_alloc_hw_nm(size_t priv_data_len,
 		return NULL;
 
 	/* check all or no channel context operations exist */
-	i = !!ops->add_chanctx + !!ops->remove_chanctx +
-	    !!ops->change_chanctx + !!ops->assign_vif_chanctx +
-	    !!ops->unassign_vif_chanctx;
-	if (WARN_ON(i != 0 && i != 5))
-		return NULL;
-	use_chanctx = i == 5;
+	if (ops->add_chanctx == ieee80211_emulate_add_chanctx &&
+	    ops->remove_chanctx == ieee80211_emulate_remove_chanctx &&
+	    ops->change_chanctx == ieee80211_emulate_change_chanctx) {
+		if (WARN_ON(ops->assign_vif_chanctx ||
+			    ops->unassign_vif_chanctx))
+			return NULL;
+		emulate_chanctx = true;
+	} else {
+		if (WARN_ON(ops->add_chanctx == ieee80211_emulate_add_chanctx ||
+			    ops->remove_chanctx == ieee80211_emulate_remove_chanctx ||
+			    ops->change_chanctx == ieee80211_emulate_change_chanctx))
+			return NULL;
+		if (WARN_ON(!ops->add_chanctx ||
+			    !ops->remove_chanctx ||
+			    !ops->change_chanctx ||
+			    !ops->assign_vif_chanctx ||
+			    !ops->unassign_vif_chanctx))
+			return NULL;
+		emulate_chanctx = false;
+	}
 
 	/* Ensure 32-byte alignment of our private data and hw private data.
 	 * We use the wiphy priv data for both our ieee80211_local and for
@@ -699,7 +832,7 @@ struct ieee80211_hw *ieee80211_alloc_hw_nm(size_t priv_data_len,
 			WIPHY_FLAG_REPORTS_OBSS |
 			WIPHY_FLAG_OFFCHAN_TX;
 
-	if (!use_chanctx || ops->remain_on_channel)
+	if (emulate_chanctx || ops->remain_on_channel)
 		wiphy->flags |= WIPHY_FLAG_HAS_REMAIN_ON_CHANNEL;
 
 	wiphy->features |= NL80211_FEATURE_SK_TX_STATUS |
@@ -756,7 +889,10 @@ struct ieee80211_hw *ieee80211_alloc_hw_nm(size_t priv_data_len,
 	local->hw.priv = (char *)local + ALIGN(sizeof(*local), NETDEV_ALIGN);
 
 	local->ops = ops;
-	local->use_chanctx = use_chanctx;
+	local->emulate_chanctx = emulate_chanctx;
+
+	if (emulate_chanctx)
+		ieee80211_hw_set(&local->hw, CHANCTX_STA_CSA);
 
 	/*
 	 * We need a bit of data queued to build aggregates properly, so
@@ -833,7 +969,6 @@ struct ieee80211_hw *ieee80211_alloc_hw_nm(size_t priv_data_len,
 			ieee80211_dfs_radar_detected_work);
 
 	wiphy_work_init(&local->reconfig_filter, ieee80211_reconfig_filter);
-	local->smps_mode = IEEE80211_SMPS_OFF;
 
 	wiphy_work_init(&local->dynamic_ps_enable_work,
 			ieee80211_dynamic_ps_enable_work);
@@ -984,7 +1119,7 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 		 * as much, e.g. monitoring beacons would be hard if we
 		 * might not even know which link is active at which time.
 		 */
-		if (WARN_ON(!local->use_chanctx))
+		if (WARN_ON(local->emulate_chanctx))
 			return -EINVAL;
 
 		if (WARN_ON(!local->ops->link_info_changed))
@@ -1028,7 +1163,7 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 		return -EINVAL;
 #endif
 
-	if (!local->use_chanctx) {
+	if (local->emulate_chanctx) {
 		for (i = 0; i < local->hw.wiphy->n_iface_combinations; i++) {
 			const struct ieee80211_iface_combination *comb;
 
@@ -1094,11 +1229,11 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 						&sband->channels[i],
 						NL80211_CHAN_NO_HT);
 			/* init channel we're on */
-			if (!local->use_chanctx && !local->_oper_chandef.chan) {
+			local->monitor_chandef = dflt_chandef;
+			if (local->emulate_chanctx) {
+				local->dflt_chandef = dflt_chandef;
 				local->hw.conf.chandef = dflt_chandef;
-				local->_oper_chandef = dflt_chandef;
 			}
-			local->monitor_chandef = dflt_chandef;
 		}
 
 		channels += sband->n_channels;
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 7c0339d4f0598..9968bc0ddf6ea 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -2287,8 +2287,7 @@ ieee80211_sta_process_chanswitch(struct ieee80211_link_data *link,
 
 	chanctx = container_of(conf, struct ieee80211_chanctx, conf);
 
-	if (local->use_chanctx &&
-	    !ieee80211_hw_check(&local->hw, CHANCTX_STA_CSA)) {
+	if (!ieee80211_hw_check(&local->hw, CHANCTX_STA_CSA)) {
 		sdata_info(sdata,
 			   "driver doesn't support chan-switch with channel contexts\n");
 		goto drop_connection;
diff --git a/net/mac80211/offchannel.c b/net/mac80211/offchannel.c
index 6c40802025733..221695d841fd3 100644
--- a/net/mac80211/offchannel.c
+++ b/net/mac80211/offchannel.c
@@ -86,7 +86,7 @@ void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local)
 
 	lockdep_assert_wiphy(local->hw.wiphy);
 
-	if (WARN_ON(local->use_chanctx))
+	if (WARN_ON(!local->emulate_chanctx))
 		return;
 
 	/*
@@ -136,7 +136,7 @@ void ieee80211_offchannel_return(struct ieee80211_local *local)
 
 	lockdep_assert_wiphy(local->hw.wiphy);
 
-	if (WARN_ON(local->use_chanctx))
+	if (WARN_ON(!local->emulate_chanctx))
 		return;
 
 	list_for_each_entry(sdata, &local->interfaces, list) {
@@ -351,10 +351,13 @@ static void _ieee80211_start_next_roc(struct ieee80211_local *local)
 		 * 20 MHz channel width) don't stop all the operations but still
 		 * treat it as though the ROC operation started properly, so
 		 * other ROC operations won't interfere with this one.
+		 *
+		 * Note: scan can't run, tmp_channel is what we use, so this
+		 * must be the currently active channel.
 		 */
-		roc->on_channel = roc->chan == local->_oper_chandef.chan &&
-				  local->_oper_chandef.width != NL80211_CHAN_WIDTH_5 &&
-				  local->_oper_chandef.width != NL80211_CHAN_WIDTH_10;
+		roc->on_channel = roc->chan == local->hw.conf.chandef.chan &&
+				  local->hw.conf.chandef.width != NL80211_CHAN_WIDTH_5 &&
+				  local->hw.conf.chandef.width != NL80211_CHAN_WIDTH_10;
 
 		/* start this ROC */
 		ieee80211_recalc_idle(local);
@@ -363,7 +366,7 @@ static void _ieee80211_start_next_roc(struct ieee80211_local *local)
 			ieee80211_offchannel_stop_vifs(local);
 
 			local->tmp_channel = roc->chan;
-			ieee80211_hw_config(local, 0);
+			ieee80211_hw_conf_chan(local);
 		}
 
 		wiphy_delayed_work_queue(local->hw.wiphy, &local->roc_work,
@@ -426,7 +429,7 @@ static void __ieee80211_roc_work(struct ieee80211_local *local)
 		return;
 
 	if (!roc->started) {
-		WARN_ON(local->use_chanctx);
+		WARN_ON(!local->emulate_chanctx);
 		_ieee80211_start_next_roc(local);
 	} else {
 		on_channel = roc->on_channel;
@@ -439,7 +442,7 @@ static void __ieee80211_roc_work(struct ieee80211_local *local)
 			ieee80211_flush_queues(local, NULL, false);
 
 			local->tmp_channel = NULL;
-			ieee80211_hw_config(local, 0);
+			ieee80211_hw_conf_chan(local);
 
 			ieee80211_offchannel_return(local);
 		}
@@ -539,7 +542,7 @@ static int ieee80211_start_roc_work(struct ieee80211_local *local,
 		/* this may work, but is untested */
 		return -EOPNOTSUPP;
 
-	if (local->use_chanctx && !local->ops->remain_on_channel)
+	if (!local->emulate_chanctx && !local->ops->remain_on_channel)
 		return -EOPNOTSUPP;
 
 	roc = kzalloc(sizeof(*roc), GFP_KERNEL);
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 81644d15fe2fa..6dedbbba153a0 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -476,7 +476,7 @@ static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
 	}
 
 	/* Set power back to normal operating levels. */
-	ieee80211_hw_config(local, 0);
+	ieee80211_hw_conf_chan(local);
 
 	if (!hw_scan && was_scanning) {
 		ieee80211_configure_filter(local);
@@ -523,7 +523,7 @@ static int ieee80211_start_sw_scan(struct ieee80211_local *local,
 				   struct ieee80211_sub_if_data *sdata)
 {
 	/* Software scan is not supported in multi-channel cases */
-	if (local->use_chanctx)
+	if (!local->emulate_chanctx)
 		return -EOPNOTSUPP;
 
 	/*
@@ -553,7 +553,7 @@ static int ieee80211_start_sw_scan(struct ieee80211_local *local,
 	ieee80211_configure_filter(local);
 
 	/* We need to set power level at maximum rate for scanning. */
-	ieee80211_hw_config(local, 0);
+	ieee80211_hw_conf_chan(local);
 
 	wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
 
@@ -790,7 +790,7 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
 	if (hw_scan) {
 		__set_bit(SCAN_HW_SCANNING, &local->scanning);
 	} else if ((req->n_channels == 1) &&
-		   (req->channels[0] == local->_oper_chandef.chan)) {
+		   (req->channels[0] == local->hw.conf.chandef.chan)) {
 		/*
 		 * If we are scanning only on the operating channel
 		 * then we do not need to stop normal activities
@@ -808,7 +808,7 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
 		ieee80211_configure_filter(local); /* accept probe-responses */
 
 		/* We need to ensure power level is at max for scanning. */
-		ieee80211_hw_config(local, 0);
+		ieee80211_hw_conf_chan(local);
 
 		if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
 						IEEE80211_CHAN_RADAR)) ||
@@ -973,13 +973,13 @@ static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
 	/* If scanning on oper channel, use whatever channel-type
 	 * is currently in use.
 	 */
-	if (chan == local->_oper_chandef.chan)
-		local->scan_chandef = local->_oper_chandef;
+	if (chan == local->hw.conf.chandef.chan)
+		local->scan_chandef = local->hw.conf.chandef;
 	else
 		local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
 
 set_channel:
-	if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
+	if (ieee80211_hw_conf_chan(local))
 		skip = 1;
 
 	/* advance state machine to next channel/band */
@@ -1023,7 +1023,7 @@ static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
 {
 	/* switch back to the operating channel */
 	local->scan_chandef.chan = NULL;
-	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
+	ieee80211_hw_conf_chan(local);
 
 	/* disable PS */
 	ieee80211_offchannel_return(local);
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 7b33942ea51f4..f57f7963ca377 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -2390,8 +2390,6 @@ netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb,
 
 	if (chanctx_conf)
 		chandef = &chanctx_conf->def;
-	else if (!local->use_chanctx)
-		chandef = &local->_oper_chandef;
 	else
 		goto fail_rcu;
 
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 1a2522e699d41..51c1a99f57b83 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -2472,9 +2472,6 @@ static void ieee80211_assign_chanctx(struct ieee80211_local *local,
 
 	lockdep_assert_wiphy(local->hw.wiphy);
 
-	if (!local->use_chanctx)
-		return;
-
 	conf = rcu_dereference_protected(link->conf->chanctx_conf,
 					 lockdep_is_held(&local->hw.wiphy->mtx));
 	if (conf) {
@@ -2704,20 +2701,20 @@ int ieee80211_reconfig(struct ieee80211_local *local)
 	}
 
 	/* add channel contexts */
-	if (local->use_chanctx) {
-		list_for_each_entry(ctx, &local->chanctx_list, list)
-			if (ctx->replace_state !=
-			    IEEE80211_CHANCTX_REPLACES_OTHER)
-				WARN_ON(drv_add_chanctx(local, ctx));
-
-		sdata = wiphy_dereference(local->hw.wiphy,
-					  local->monitor_sdata);
-		if (sdata && ieee80211_sdata_running(sdata))
-			ieee80211_assign_chanctx(local, sdata, &sdata->deflink);
-	}
+	list_for_each_entry(ctx, &local->chanctx_list, list)
+		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
+			WARN_ON(drv_add_chanctx(local, ctx));
+
+	sdata = wiphy_dereference(local->hw.wiphy, local->monitor_sdata);
+	if (sdata && ieee80211_sdata_running(sdata))
+		ieee80211_assign_chanctx(local, sdata, &sdata->deflink);
 
 	/* reconfigure hardware */
-	ieee80211_hw_config(local, ~0);
+	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_LISTEN_INTERVAL |
+				   IEEE80211_CONF_CHANGE_MONITOR |
+				   IEEE80211_CONF_CHANGE_PS |
+				   IEEE80211_CONF_CHANGE_RETRY_LIMITS |
+				   IEEE80211_CONF_CHANGE_IDLE);
 
 	ieee80211_configure_filter(local);