mac80211: track needed RX chains for channel contexts

On each channel that the device is operating on, it
may need to listen using one or more chains depending
on the SMPS settings of the interfaces using it. The
previous channel context changes completely removed
this ability (before, it was available as the SMPS
mode).

Add per-context tracking of the required static and
dynamic RX chains and notify the driver on changes.
To achieve this, track the chains and SMPS mode used
on each virtual interface and update the channel
context whenever this changes.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 14 insertions, 1 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index d9d2119f082..3560881d17e 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -146,9 +146,11 @@ struct ieee80211_low_level_stats {
 /**
  * enum ieee80211_chanctx_change - change flag for channel context
  * @IEEE80211_CHANCTX_CHANGE_CHANNEL_TYPE: The channel type was changed
+ * @IEEE80211_CHANCTX_CHANGE_RX_CHAINS: The number of RX chains changed
  */
 enum ieee80211_chanctx_change {
         IEEE80211_CHANCTX_CHANGE_CHANNEL_TYPE   = BIT(0),
+        IEEE80211_CHANCTX_CHANGE_RX_CHAINS      = BIT(1),
 };
 
 /**
@@ -159,6 +161,11 @@ enum ieee80211_chanctx_change {
  *
  * @channel: the channel to tune to
  * @channel_type: the channel (HT) type
+ * @rx_chains_static: The number of RX chains that must always be
+ *      active on the channel to receive MIMO transmissions
+ * @rx_chains_dynamic: The number of RX chains that must be enabled
+ *      after RTS/CTS handshake to receive SMPS MIMO transmissions;
+ *      this will always be >= @rx_chains_always.
  * @drv_priv: data area for driver use, will always be aligned to
  *      sizeof(void *), size is determined in hw information.
  */
@@ -166,6 +173,8 @@ struct ieee80211_chanctx_conf {
         struct ieee80211_channel *channel;
         enum nl80211_channel_type channel_type;
 
+        u8 rx_chains_static, rx_chains_dynamic;
+
         u8 drv_priv[0] __attribute__((__aligned__(sizeof(void *))));
 };
 
@@ -820,6 +829,8 @@ enum ieee80211_conf_flags {
  * @IEEE80211_CONF_CHANGE_RETRY_LIMITS: retry limits changed
  * @IEEE80211_CONF_CHANGE_IDLE: Idle flag changed
  * @IEEE80211_CONF_CHANGE_SMPS: Spatial multiplexing powersave mode changed
+ *      Note that this is only valid if channel contexts are not used,
+ *      otherwise each channel context has the number of chains listed.
  */
 enum ieee80211_conf_changed {
         IEEE80211_CONF_CHANGE_SMPS              = BIT(1),
@@ -885,7 +896,9 @@ enum ieee80211_smps_mode {
  *
  * @smps_mode: spatial multiplexing powersave mode; note that
  *      %IEEE80211_SMPS_STATIC is used when the device is not
- *      configured for an HT channel
+ *      configured for an HT channel.
+ *      Note that this is only valid if channel contexts are not used,
+ *      otherwise each channel context has the number of chains listed.
  */
 struct ieee80211_conf {
         u32 flags;