iwlwifi: mvm: add per-interface debugfs with mac_params file

Use the per-interface debugfs infrastructure to create a
directory and symlink, and add a file containing debug
data related to each virtual interface.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/iwlwifi/mvm/debugfs.c

@@ -300,6 +300,58 @@ static ssize_t iwl_dbgfs_power_down_d3_allow_write(struct file *file,
 	return count;
 }
 
+static ssize_t iwl_dbgfs_mac_params_read(struct file *file,
+					 char __user *user_buf,
+					 size_t count, loff_t *ppos)
+{
+	struct ieee80211_vif *vif = file->private_data;
+	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
+	struct iwl_mvm *mvm = mvmvif->dbgfs_data;
+	u8 ap_sta_id;
+	struct ieee80211_chanctx_conf *chanctx_conf;
+	char buf[512];
+	int bufsz = sizeof(buf);
+	int pos = 0;
+	int i;
+
+	mutex_lock(&mvm->mutex);
+
+	ap_sta_id = mvmvif->ap_sta_id;
+
+	pos += scnprintf(buf+pos, bufsz-pos, "mac id/color: %d / %d\n",
+			 mvmvif->id, mvmvif->color);
+	pos += scnprintf(buf+pos, bufsz-pos, "bssid: %pM\n",
+			 vif->bss_conf.bssid);
+	pos += scnprintf(buf+pos, bufsz-pos, "QoS:\n");
+	for (i = 0; i < ARRAY_SIZE(mvmvif->queue_params); i++) {
+		pos += scnprintf(buf+pos, bufsz-pos,
+				 "\t%d: txop:%d - cw_min:%d - cw_max = %d - aifs = %d upasd = %d\n",
+				 i, mvmvif->queue_params[i].txop,
+				 mvmvif->queue_params[i].cw_min,
+				 mvmvif->queue_params[i].cw_max,
+				 mvmvif->queue_params[i].aifs,
+				 mvmvif->queue_params[i].uapsd);
+	}
+
+	if (vif->type == NL80211_IFTYPE_STATION)
+		pos += scnprintf(buf+pos, bufsz-pos, "ap_sta_id %d\n",
+				 ap_sta_id);
+
+	rcu_read_lock();
+	chanctx_conf = rcu_dereference(vif->chanctx_conf);
+	if (chanctx_conf) {
+		pos += scnprintf(buf+pos, bufsz-pos,
+				 "idle rx chains %d, active rx chains: %d\n",
+				 chanctx_conf->rx_chains_static,
+				 chanctx_conf->rx_chains_dynamic);
+	}
+	rcu_read_unlock();
+
+	mutex_unlock(&mvm->mutex);
+
+	return simple_read_from_buffer(user_buf, count, ppos, buf, pos);
+}
+
 #define BT_MBOX_MSG(_notif, _num, _field)				     \
 	((le32_to_cpu((_notif)->mbox_msg[(_num)]) & BT_MBOX##_num##_##_field)\
 	>> BT_MBOX##_num##_##_field##_POS)
@@ -464,6 +516,9 @@ MVM_DEBUGFS_WRITE_FILE_OPS(power_down_allow);
 MVM_DEBUGFS_WRITE_FILE_OPS(power_down_d3_allow);
 MVM_DEBUGFS_WRITE_FILE_OPS(fw_restart);
 
+/* Interface specific debugfs entries */
+MVM_DEBUGFS_READ_FILE_OPS(mac_params);
+
 int iwl_mvm_dbgfs_register(struct iwl_mvm *mvm, struct dentry *dbgfs_dir)
 {
 	char buf[100];
@@ -494,3 +549,58 @@ int iwl_mvm_dbgfs_register(struct iwl_mvm *mvm, struct dentry *dbgfs_dir)
 	IWL_ERR(mvm, "Can't create the mvm debugfs directory\n");
 	return -ENOMEM;
 }
+
+void iwl_mvm_vif_dbgfs_register(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
+{
+	struct dentry *dbgfs_dir = vif->debugfs_dir;
+	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
+	char buf[100];
+
+	if (!dbgfs_dir)
+		return;
+
+	mvmvif->dbgfs_dir = debugfs_create_dir("iwlmvm", dbgfs_dir);
+	mvmvif->dbgfs_data = mvm;
+
+	if (!mvmvif->dbgfs_dir) {
+		IWL_ERR(mvm, "Failed to create debugfs directory under %s\n",
+			dbgfs_dir->d_name.name);
+		return;
+	}
+
+	MVM_DEBUGFS_ADD_FILE_VIF(mac_params, mvmvif->dbgfs_dir,
+				 S_IRUSR);
+
+	/*
+	 * Create symlink for convenience pointing to interface specific
+	 * debugfs entries for the driver. For example, under
+	 * /sys/kernel/debug/iwlwifi/0000\:02\:00.0/iwlmvm/
+	 * find
+	 * netdev:wlan0 -> ../../../ieee80211/phy0/netdev:wlan0/iwlmvm/
+	 */
+	snprintf(buf, 100, "../../../%s/%s/%s/%s",
+		 dbgfs_dir->d_parent->d_parent->d_name.name,
+		 dbgfs_dir->d_parent->d_name.name,
+		 dbgfs_dir->d_name.name,
+		 mvmvif->dbgfs_dir->d_name.name);
+
+	mvmvif->dbgfs_slink = debugfs_create_symlink(dbgfs_dir->d_name.name,
+						     mvm->debugfs_dir, buf);
+	if (!mvmvif->dbgfs_slink)
+		IWL_ERR(mvm, "Can't create debugfs symbolic link under %s\n",
+			dbgfs_dir->d_name.name);
+	return;
+err:
+	IWL_ERR(mvm, "Can't create debugfs entity\n");
+}
+
+void iwl_mvm_vif_dbgfs_clean(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
+{
+	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
+
+	debugfs_remove(mvmvif->dbgfs_slink);
+	mvmvif->dbgfs_slink = NULL;
+
+	debugfs_remove_recursive(mvmvif->dbgfs_dir);
+	mvmvif->dbgfs_dir = NULL;
+}

drivers/net/wireless/iwlwifi/mvm/mac80211.c

@@ -562,6 +562,7 @@ static int iwl_mvm_mac_add_interface(struct ieee80211_hw *hw,
 		mvm->p2p_device_vif = vif;
 	}
 
+	iwl_mvm_vif_dbgfs_register(mvm, vif);
 	goto out_unlock;
 
  out_unbind:
@@ -640,6 +641,8 @@ static void iwl_mvm_mac_remove_interface(struct ieee80211_hw *hw,
 
 	mutex_lock(&mvm->mutex);
 
+	iwl_mvm_vif_dbgfs_clean(mvm, vif);
+
 	/*
 	 * For AP/GO interface, the tear down of the resources allocated to the
 	 * interface is be handled as part of the stop_ap flow.

drivers/net/wireless/iwlwifi/mvm/mvm.h

@@ -212,6 +212,7 @@ struct iwl_mvm_vif {
 
 #ifdef CONFIG_IWLWIFI_DEBUGFS
 	struct dentry *dbgfs_dir;
+	struct dentry *dbgfs_slink;
 	void *dbgfs_data;
 #endif
 };
@@ -471,8 +472,8 @@ void iwl_mvm_cancel_scan(struct iwl_mvm *mvm);
 /* MVM debugfs */
 #ifdef CONFIG_IWLWIFI_DEBUGFS
 int iwl_mvm_dbgfs_register(struct iwl_mvm *mvm, struct dentry *dbgfs_dir);
-int iwl_mvm_vif_dbgfs_register(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
-			       struct dentry *dbgfs_dir);
+void iwl_mvm_vif_dbgfs_register(struct iwl_mvm *mvm, struct ieee80211_vif *vif);
+void iwl_mvm_vif_dbgfs_clean(struct iwl_mvm *mvm, struct ieee80211_vif *vif);
 void iwl_power_get_params(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 			  struct iwl_powertable_cmd *cmd);
 #else
@@ -481,6 +482,14 @@ static inline int iwl_mvm_dbgfs_register(struct iwl_mvm *mvm,
 {
 	return 0;
 }
+static inline void
+iwl_mvm_vif_dbgfs_register(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
+{
+}
+static inline void
+iwl_mvm_vif_dbgfs_clean(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
+{
+}
 #endif /* CONFIG_IWLWIFI_DEBUGFS */
 
 /* rate scaling */