wifi: mac80211: replace link_id with link_conf in switch/(un)assign_vif_chanctx()

Since mac80211 already has a protected pointer to link_conf,
pass it to the driver to avoid additional RCU locking.

Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

4 files changed, 31 insertions, 22 deletions

diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index 2e9bc285f0a5..f247daa41563 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -835,7 +835,6 @@ static int ieee80211_assign_link_chanctx(struct ieee80211_link_data *link,
 					 struct ieee80211_chanctx *new_ctx)
 {
 	struct ieee80211_sub_if_data *sdata = link->sdata;
-	unsigned int link_id = link->link_id;
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_chanctx_conf *conf;
 	struct ieee80211_chanctx *curr_ctx = NULL;
@@ -850,13 +849,13 @@ static int ieee80211_assign_link_chanctx(struct ieee80211_link_data *link,
 	if (conf) {
 		curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);
 
-		drv_unassign_vif_chanctx(local, sdata, link_id, curr_ctx);
+		drv_unassign_vif_chanctx(local, sdata, link->conf, curr_ctx);
 		conf = NULL;
 		list_del(&link->assigned_chanctx_list);
 	}
 
 	if (new_ctx) {
-		ret = drv_assign_vif_chanctx(local, sdata, link_id, new_ctx);
+		ret = drv_assign_vif_chanctx(local, sdata, link->conf, new_ctx);
 		if (ret)
 			goto out;
 
@@ -1276,7 +1275,7 @@ ieee80211_link_use_reserved_reassign(struct ieee80211_link_data *link)
 	vif_chsw[0].vif = &sdata->vif;
 	vif_chsw[0].old_ctx = &old_ctx->conf;
 	vif_chsw[0].new_ctx = &new_ctx->conf;
-	vif_chsw[0].link_id = link->link_id;
+	vif_chsw[0].link_conf = link->conf;
 
 	list_del(&link->reserved_chanctx_list);
 	link->reserved_chanctx = NULL;
@@ -1440,7 +1439,7 @@ static int ieee80211_chsw_switch_vifs(struct ieee80211_local *local,
 			vif_chsw[i].vif = &link->sdata->vif;
 			vif_chsw[i].old_ctx = &old_ctx->conf;
 			vif_chsw[i].new_ctx = &ctx->conf;
-			vif_chsw[i].link_id = link->link_id;
+			vif_chsw[i].link_conf = link->conf;
 
 			i++;
 		}
diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
index a04a88d122b7..0f06081c68ca 100644
--- a/net/mac80211/driver-ops.h
+++ b/net/mac80211/driver-ops.h
@@ -937,22 +937,31 @@ static inline void drv_change_chanctx(struct ieee80211_local *local,
 	trace_drv_return_void(local);
 }
 
+static inline void drv_verify_link_exists(struct ieee80211_sub_if_data *sdata,
+					  struct ieee80211_bss_conf *link_conf)
+{
+	/* deflink always exists, so need to check only for other links */
+	if (sdata->deflink.conf != link_conf)
+		sdata_assert_lock(sdata);
+}
+
 static inline int drv_assign_vif_chanctx(struct ieee80211_local *local,
 					 struct ieee80211_sub_if_data *sdata,
-					 unsigned int link_id,
+					 struct ieee80211_bss_conf *link_conf,
 					 struct ieee80211_chanctx *ctx)
 {
 	int ret = 0;
 
+	drv_verify_link_exists(sdata, link_conf);
 	if (!check_sdata_in_driver(sdata))
 		return -EIO;
 
-	trace_drv_assign_vif_chanctx(local, sdata, link_id, ctx);
+	trace_drv_assign_vif_chanctx(local, sdata, link_conf, ctx);
 	if (local->ops->assign_vif_chanctx) {
 		WARN_ON_ONCE(!ctx->driver_present);
 		ret = local->ops->assign_vif_chanctx(&local->hw,
 						     &sdata->vif,
-						     link_id,
+						     link_conf,
 						     &ctx->conf);
 	}
 	trace_drv_return_int(local, ret);
@@ -962,20 +971,21 @@ static inline int drv_assign_vif_chanctx(struct ieee80211_local *local,
 
 static inline void drv_unassign_vif_chanctx(struct ieee80211_local *local,
 					    struct ieee80211_sub_if_data *sdata,
-					    unsigned int link_id,
+					    struct ieee80211_bss_conf *link_conf,
 					    struct ieee80211_chanctx *ctx)
 {
 	might_sleep();
 
+	drv_verify_link_exists(sdata, link_conf);
 	if (!check_sdata_in_driver(sdata))
 		return;
 
-	trace_drv_unassign_vif_chanctx(local, sdata, link_id, ctx);
+	trace_drv_unassign_vif_chanctx(local, sdata, link_conf, ctx);
 	if (local->ops->unassign_vif_chanctx) {
 		WARN_ON_ONCE(!ctx->driver_present);
 		local->ops->unassign_vif_chanctx(&local->hw,
 						 &sdata->vif,
-						 link_id,
+						 link_conf,
 						 &ctx->conf);
 	}
 	trace_drv_return_void(local);
@@ -992,7 +1002,7 @@ static inline int drv_start_ap(struct ieee80211_local *local,
 	int ret = 0;
 
 	/* make sure link_conf is protected */
-	sdata_assert_lock(sdata);
+	drv_verify_link_exists(sdata, link_conf);
 
 	might_sleep();
 
@@ -1011,7 +1021,7 @@ static inline void drv_stop_ap(struct ieee80211_local *local,
 			       struct ieee80211_bss_conf *link_conf)
 {
 	/* make sure link_conf is protected */
-	sdata_assert_lock(sdata);
+	drv_verify_link_exists(sdata, link_conf);
 
 	if (!check_sdata_in_driver(sdata))
 		return;
diff --git a/net/mac80211/trace.h b/net/mac80211/trace.h
index 75e5c1376351..402110f439f8 100644
--- a/net/mac80211/trace.h
+++ b/net/mac80211/trace.h
@@ -1669,7 +1669,7 @@ TRACE_EVENT(drv_switch_vif_chanctx,
 
 				SWITCH_ENTRY_ASSIGN(vif.vif_type, vif->type);
 				SWITCH_ENTRY_ASSIGN(vif.p2p, vif->p2p);
-				SWITCH_ENTRY_ASSIGN(link_id, link_id);
+				SWITCH_ENTRY_ASSIGN(link_id, link_conf->link_id);
 				strncpy(local_vifs[i].vif.vif_name,
 					sdata->name,
 					sizeof(local_vifs[i].vif.vif_name));
@@ -1710,10 +1710,10 @@ TRACE_EVENT(drv_switch_vif_chanctx,
 DECLARE_EVENT_CLASS(local_sdata_chanctx,
 	TP_PROTO(struct ieee80211_local *local,
 		 struct ieee80211_sub_if_data *sdata,
-		 unsigned int link_id,
+		 struct ieee80211_bss_conf *link_conf,
 		 struct ieee80211_chanctx *ctx),
 
-	TP_ARGS(local, sdata, link_id, ctx),
+	TP_ARGS(local, sdata, link_conf, ctx),
 
 	TP_STRUCT__entry(
 		LOCAL_ENTRY
@@ -1726,7 +1726,7 @@ DECLARE_EVENT_CLASS(local_sdata_chanctx,
 		LOCAL_ASSIGN;
 		VIF_ASSIGN;
 		CHANCTX_ASSIGN;
-		__entry->link_id = link_id;
+		__entry->link_id = link_conf->link_id;
 	),
 
 	TP_printk(
@@ -1738,17 +1738,17 @@ DECLARE_EVENT_CLASS(local_sdata_chanctx,
 DEFINE_EVENT(local_sdata_chanctx, drv_assign_vif_chanctx,
 	TP_PROTO(struct ieee80211_local *local,
 		 struct ieee80211_sub_if_data *sdata,
-		 unsigned int link_id,
+		 struct ieee80211_bss_conf *link_conf,
 		 struct ieee80211_chanctx *ctx),
-	TP_ARGS(local, sdata, link_id, ctx)
+	TP_ARGS(local, sdata, link_conf, ctx)
 );
 
 DEFINE_EVENT(local_sdata_chanctx, drv_unassign_vif_chanctx,
 	TP_PROTO(struct ieee80211_local *local,
 		 struct ieee80211_sub_if_data *sdata,
-		 unsigned int link_id,
+		 struct ieee80211_bss_conf *link_conf,
 		 struct ieee80211_chanctx *ctx),
-	TP_ARGS(local, sdata, link_id, ctx)
+	TP_ARGS(local, sdata, link_conf, ctx)
 );
 
 TRACE_EVENT(drv_start_ap,
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 739c05fdb9bb..8cb93d65b80e 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -2270,7 +2270,7 @@ static void ieee80211_assign_chanctx(struct ieee80211_local *local,
 					 lockdep_is_held(&local->chanctx_mtx));
 	if (conf) {
 		ctx = container_of(conf, struct ieee80211_chanctx, conf);
-		drv_assign_vif_chanctx(local, sdata, link->link_id, ctx);
+		drv_assign_vif_chanctx(local, sdata, link->conf, ctx);
 	}
 	mutex_unlock(&local->chanctx_mtx);
 }