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, 12 insertions, 9 deletions

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index cb4684a9451e..70c48cad180a 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -884,6 +884,9 @@ struct ieee80211_chanctx {
 	enum ieee80211_chanctx_mode mode;
 	bool driver_present;
 
+	/* temporary data for search algorithm etc. */
+	struct ieee80211_chan_req req;
+
 	struct ieee80211_chanctx_conf conf;
 };
 
@@ -1035,7 +1038,7 @@ struct ieee80211_link_data {
 
 	bool operating_11g_mode;
 
-	struct cfg80211_chan_def csa_chandef;
+	struct ieee80211_chan_req csa_chanreq;
 
 	struct wiphy_work color_change_finalize_work;
 	struct delayed_work color_collision_detect_work;
@@ -1043,7 +1046,7 @@ struct ieee80211_link_data {
 
 	/* context reservation -- protected with wiphy mutex */
 	struct ieee80211_chanctx *reserved_chanctx;
-	struct cfg80211_chan_def reserved_chandef;
+	struct ieee80211_chan_req reserved;
 	bool reserved_radar_required;
 	bool reserved_ready;
 
@@ -1574,7 +1577,7 @@ struct ieee80211_local {
 
 	/* virtual monitor interface */
 	struct ieee80211_sub_if_data __rcu *monitor_sdata;
-	struct cfg80211_chan_def monitor_chandef;
+	struct ieee80211_chan_req monitor_chanreq;
 
 	/* extended capabilities provided by mac80211 */
 	u8 ext_capa[8];
@@ -1639,7 +1642,7 @@ ieee80211_get_link_sband(struct ieee80211_link_data *link)
 
 /* this struct holds the value parsing from channel switch IE  */
 struct ieee80211_csa_ie {
-	struct cfg80211_chan_def chandef;
+	struct ieee80211_chan_req chanreq;
 	u8 mode;
 	u8 count;
 	u8 ttl;
@@ -2523,11 +2526,11 @@ void ieee80211_chandef_downgrade(struct cfg80211_chan_def *chandef,
 
 int __must_check
 ieee80211_link_use_channel(struct ieee80211_link_data *link,
-			   const struct cfg80211_chan_def *chandef,
+			   const struct ieee80211_chan_req *req,
 			   enum ieee80211_chanctx_mode mode);
 int __must_check
 ieee80211_link_reserve_chanctx(struct ieee80211_link_data *link,
-			       const struct cfg80211_chan_def *chandef,
+			       const struct ieee80211_chan_req *req,
 			       enum ieee80211_chanctx_mode mode,
 			       bool radar_required);
 int __must_check
@@ -2535,9 +2538,9 @@ ieee80211_link_use_reserved_context(struct ieee80211_link_data *link);
 int ieee80211_link_unreserve_chanctx(struct ieee80211_link_data *link);
 
 int __must_check
-ieee80211_link_change_bandwidth(struct ieee80211_link_data *link,
-				const struct cfg80211_chan_def *chandef,
-				u64 *changed);
+ieee80211_link_change_chanreq(struct ieee80211_link_data *link,
+			      const struct ieee80211_chan_req *req,
+			      u64 *changed);
 void ieee80211_link_release_channel(struct ieee80211_link_data *link);
 void ieee80211_link_vlan_copy_chanctx(struct ieee80211_link_data *link);
 void ieee80211_link_copy_chanctx_to_vlans(struct ieee80211_link_data *link,