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>
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 879ca62..87d4670 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -1585,9 +1585,13 @@
 	}
 
 	if (info->attrs[NL80211_ATTR_WIPHY_TX_POWER_SETTING]) {
+		struct wireless_dev *txp_wdev = wdev;
 		enum nl80211_tx_power_setting type;
 		int idx, mbm = 0;
 
+		if (!(rdev->wiphy.features & NL80211_FEATURE_VIF_TXPOWER))
+			txp_wdev = NULL;
+
 		if (!rdev->ops->set_tx_power) {
 			result = -EOPNOTSUPP;
 			goto bad_res;
@@ -1607,7 +1611,7 @@
 			mbm = nla_get_u32(info->attrs[idx]);
 		}
 
-		result = rdev_set_tx_power(rdev, type, mbm);
+		result = rdev_set_tx_power(rdev, txp_wdev, type, mbm);
 		if (result)
 			goto bad_res;
 	}
diff --git a/net/wireless/rdev-ops.h b/net/wireless/rdev-ops.h
index eb5f897..6e5fa65 100644
--- a/net/wireless/rdev-ops.h
+++ b/net/wireless/rdev-ops.h
@@ -476,21 +476,22 @@
 }
 
 static inline int rdev_set_tx_power(struct cfg80211_registered_device *rdev,
+				    struct wireless_dev *wdev,
 				    enum nl80211_tx_power_setting type, int mbm)
 {
 	int ret;
-	trace_rdev_set_tx_power(&rdev->wiphy, type, mbm);
-	ret = rdev->ops->set_tx_power(&rdev->wiphy, type, mbm);
+	trace_rdev_set_tx_power(&rdev->wiphy, wdev, type, mbm);
+	ret = rdev->ops->set_tx_power(&rdev->wiphy, wdev, type, mbm);
 	trace_rdev_return_int(&rdev->wiphy, ret);
 	return ret;
 }
 
 static inline int rdev_get_tx_power(struct cfg80211_registered_device *rdev,
-				    int *dbm)
+				    struct wireless_dev *wdev, int *dbm)
 {
 	int ret;
-	trace_rdev_get_tx_power(&rdev->wiphy);
-	ret = rdev->ops->get_tx_power(&rdev->wiphy, dbm);
+	trace_rdev_get_tx_power(&rdev->wiphy, wdev);
+	ret = rdev->ops->get_tx_power(&rdev->wiphy, wdev, dbm);
 	trace_rdev_return_int_int(&rdev->wiphy, ret, *dbm);
 	return ret;
 }
diff --git a/net/wireless/trace.h b/net/wireless/trace.h
index 0ca71ca..8e03c63 100644
--- a/net/wireless/trace.h
+++ b/net/wireless/trace.h
@@ -26,7 +26,7 @@
 #define WIPHY_PR_ARG MAC_PR_ARG(wiphy_mac)
 
 #define WDEV_ENTRY __field(u32, id)
-#define WDEV_ASSIGN (__entry->id) = (wdev->identifier)
+#define WDEV_ASSIGN (__entry->id) = (wdev ? wdev->identifier : 0)
 #define WDEV_PR_FMT ", wdev id: %u"
 #define WDEV_PR_ARG (__entry->id)
 
@@ -260,11 +260,6 @@
 	TP_ARGS(wiphy)
 );
 
-DEFINE_EVENT(wiphy_only_evt, rdev_get_tx_power,
-	TP_PROTO(struct wiphy *wiphy),
-	TP_ARGS(wiphy)
-);
-
 DEFINE_EVENT(wiphy_only_evt, rdev_rfkill_poll,
 	TP_PROTO(struct wiphy *wiphy),
 	TP_ARGS(wiphy)
@@ -1230,22 +1225,29 @@
 		  WIPHY_PR_ARG, __entry->changed)
 );
 
+DEFINE_EVENT(wiphy_wdev_evt, rdev_get_tx_power,
+	TP_PROTO(struct wiphy *wiphy, struct wireless_dev *wdev),
+	TP_ARGS(wiphy, wdev)
+);
+
 TRACE_EVENT(rdev_set_tx_power,
-	TP_PROTO(struct wiphy *wiphy, enum nl80211_tx_power_setting type,
-		 int mbm),
-	TP_ARGS(wiphy, type, mbm),
+	TP_PROTO(struct wiphy *wiphy, struct wireless_dev *wdev,
+		 enum nl80211_tx_power_setting type, int mbm),
+	TP_ARGS(wiphy, wdev, type, mbm),
 	TP_STRUCT__entry(
 		WIPHY_ENTRY
+		WDEV_ENTRY
 		__field(enum nl80211_tx_power_setting, type)
 		__field(int, mbm)
 	),
 	TP_fast_assign(
 		WIPHY_ASSIGN;
+		WDEV_ASSIGN;
 		__entry->type = type;
 		__entry->mbm = mbm;
 	),
-	TP_printk(WIPHY_PR_FMT ", type: %d, mbm: %d",
-		  WIPHY_PR_ARG, __entry->type, __entry->mbm)
+	TP_printk(WIPHY_PR_FMT WDEV_PR_FMT ", type: %d, mbm: %d",
+		  WIPHY_PR_ARG, WDEV_PR_ARG,__entry->type, __entry->mbm)
 );
 
 TRACE_EVENT(rdev_return_int_int,
diff --git a/net/wireless/wext-compat.c b/net/wireless/wext-compat.c
index 6488d2d..742ab6e 100644
--- a/net/wireless/wext-compat.c
+++ b/net/wireless/wext-compat.c
@@ -895,7 +895,7 @@
 		return 0;
 	}
 
-	return rdev_set_tx_power(rdev, type, DBM_TO_MBM(dbm));
+	return rdev_set_tx_power(rdev, wdev, type, DBM_TO_MBM(dbm));
 }
 
 static int cfg80211_wext_giwtxpower(struct net_device *dev,
@@ -914,7 +914,7 @@
 	if (!rdev->ops->get_tx_power)
 		return -EOPNOTSUPP;
 
-	err = rdev_get_tx_power(rdev, &val);
+	err = rdev_get_tx_power(rdev, wdev, &val);
 	if (err)
 		return err;