cfg80211: allow per interface TX power setting

The TX power setting is currently per wiphy (hardware
device) but with multi-channel capabilities that doesn't
make much sense any more.

Allow drivers (and mac80211) to advertise support for
per-interface TX power configuration. When the TX power
is configured for the wiphy, the wdev will be NULL and
the driver can still handle that, but when a wdev is
given the TX power can be set only for that wdev now.

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

2 files changed, 9 insertions, 3 deletions

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index c6964572890f..8034a4268fcb 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1551,7 +1551,10 @@ struct cfg80211_gtk_rekey_data {
  *      struct wiphy. If returning an error, no value should be changed.
  *
  * @set_tx_power: set the transmit power according to the parameters,
- *      the power passed is in mBm, to get dBm use MBM_TO_DBM().
+ *      the power passed is in mBm, to get dBm use MBM_TO_DBM(). The
+ *      wdev may be %NULL if power was set for the wiphy, and will
+ *      always be %NULL unless the driver supports per-vif TX power
+ *      (as advertised by the nl80211 feature flag.)
  * @get_tx_power: store the current TX power into the dbm variable;
  *      return 0 if successful
  *
@@ -1748,9 +1751,10 @@ struct cfg80211_ops {
 
         int     (*set_wiphy_params)(struct wiphy *wiphy, u32 changed);
 
-        int     (*set_tx_power)(struct wiphy *wiphy,
+        int     (*set_tx_power)(struct wiphy *wiphy, struct wireless_dev *wdev,
                                 enum nl80211_tx_power_setting type, int mbm);
-        int     (*get_tx_power)(struct wiphy *wiphy, int *dbm);
+        int     (*get_tx_power)(struct wiphy *wiphy, struct wireless_dev *wdev,
+                                int *dbm);
 
         int     (*set_wds_peer)(struct wiphy *wiphy, struct net_device *dev,
                                 const u8 *addr);
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 617d0fbfc96f..4c5f6748ed7d 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -3051,6 +3051,7 @@ enum nl80211_ap_sme_features {
  * @NL80211_FEATURE_LOW_PRIORITY_SCAN: This driver supports low priority scan
  * @NL80211_FEATURE_SCAN_FLUSH: Scan flush is supported
  * @NL80211_FEATURE_AP_SCAN: Support scanning using an AP vif
+ * @NL80211_FEATURE_VIF_TXPOWER: The driver supports per-vif TX power setting
  */
 enum nl80211_feature_flags {
         NL80211_FEATURE_SK_TX_STATUS                    = 1 << 0,
@@ -3062,6 +3063,7 @@ enum nl80211_feature_flags {
         NL80211_FEATURE_LOW_PRIORITY_SCAN               = 1 << 6,
         NL80211_FEATURE_SCAN_FLUSH                      = 1 << 7,
         NL80211_FEATURE_AP_SCAN                         = 1 << 8,
+        NL80211_FEATURE_VIF_TXPOWER                     = 1 << 9,
 };
 
 /**