wifi: iwlwifi: mvm: rework debugfs handling

mac80211 added a new callback to add a vif debugfs.
Implement it instead of adding the debugfs directly,
which will make it properly preserved over switching
the vif from non-MLD/MLD and back.

This requires some rework so that we still have the
symlink but trust mac80211 to add/remove the debugfs.
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20231004123422.818810e242e6.I805a28f9fbef5c52a3a575d04e7a6a909ecf9078@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/intel/iwlwifi/mvm/debugfs-vif.c

@@ -699,19 +699,11 @@ MVM_DEBUGFS_READ_WRITE_FILE_OPS(rx_phyinfo, 10);
 MVM_DEBUGFS_READ_WRITE_FILE_OPS(quota_min, 32);
 MVM_DEBUGFS_READ_FILE_OPS(os_device_timediff);
 
-
-void iwl_mvm_vif_dbgfs_register(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
+void iwl_mvm_vif_add_debugfs(struct ieee80211_hw *hw, struct ieee80211_vif *vif)
 {
+	struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
 	struct dentry *dbgfs_dir = vif->debugfs_dir;
 	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
-	char buf[100];
-
-	/*
-	 * Check if debugfs directory already exist before creating it.
-	 * This may happen when, for example, resetting hw or suspend-resume
-	 */
-	if (!dbgfs_dir || mvmvif->dbgfs_dir)
-		return;
 
 	mvmvif->dbgfs_dir = debugfs_create_dir("iwlmvm", dbgfs_dir);
 	if (IS_ERR_OR_NULL(mvmvif->dbgfs_dir)) {
@@ -737,6 +729,17 @@ void iwl_mvm_vif_dbgfs_register(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
 	if (vif->type == NL80211_IFTYPE_STATION && !vif->p2p &&
 	    mvmvif == mvm->bf_allowed_vif)
 		MVM_DEBUGFS_ADD_FILE_VIF(bf_params, mvmvif->dbgfs_dir, 0600);
+}
+
+void iwl_mvm_vif_dbgfs_add_link(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];
+
+	/* this will happen in monitor mode */
+	if (!dbgfs_dir)
+		return;
 
 	/*
 	 * Create symlink for convenience pointing to interface specific
@@ -745,21 +748,16 @@ void iwl_mvm_vif_dbgfs_register(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
 	 * find
 	 * netdev:wlan0 -> ../../../ieee80211/phy0/netdev:wlan0/iwlmvm/
 	 */
-	snprintf(buf, 100, "../../../%pd3/%pd",
-		 dbgfs_dir,
-		 mvmvif->dbgfs_dir);
+	snprintf(buf, 100, "../../../%pd3/iwlmvm", dbgfs_dir);
 
 	mvmvif->dbgfs_slink = debugfs_create_symlink(dbgfs_dir->d_name.name,
 						     mvm->debugfs_dir, buf);
 }
 
-void iwl_mvm_vif_dbgfs_clean(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
+void iwl_mvm_vif_dbgfs_rm_link(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/intel/iwlwifi/mvm/mac80211.c

@@ -1580,7 +1580,7 @@ static int iwl_mvm_mac_add_interface(struct ieee80211_hw *hw,
 	 */
 	if (vif->type == NL80211_IFTYPE_AP ||
 	    vif->type == NL80211_IFTYPE_ADHOC) {
-		iwl_mvm_vif_dbgfs_register(mvm, vif);
+		iwl_mvm_vif_dbgfs_add_link(mvm, vif);
 		ret = 0;
 		goto out;
 	}
@@ -1644,7 +1644,7 @@ static int iwl_mvm_mac_add_interface(struct ieee80211_hw *hw,
 			iwl_mvm_chandef_get_primary_80(&vif->bss_conf.chandef);
 	}
 
-	iwl_mvm_vif_dbgfs_register(mvm, vif);
+	iwl_mvm_vif_dbgfs_add_link(mvm, vif);
 
 	if (!test_bit(IWL_MVM_STATUS_IN_HW_RESTART, &mvm->status) &&
 	    vif->type == NL80211_IFTYPE_STATION && !vif->p2p &&
@@ -1732,7 +1732,7 @@ static bool iwl_mvm_mac_remove_interface_common(struct ieee80211_hw *hw,
 	if (vif->bss_conf.ftm_responder)
 		memset(&mvm->ftm_resp_stats, 0, sizeof(mvm->ftm_resp_stats));
 
-	iwl_mvm_vif_dbgfs_clean(mvm, vif);
+	iwl_mvm_vif_dbgfs_rm_link(mvm, vif);
 
 	/*
 	 * For AP/GO interface, the tear down of the resources allocated to the
@@ -6324,6 +6324,7 @@ const struct ieee80211_ops iwl_mvm_hw_ops = {
 
 	.can_aggregate_in_amsdu = iwl_mvm_mac_can_aggregate,
 #ifdef CONFIG_IWLWIFI_DEBUGFS
+	.vif_add_debugfs = iwl_mvm_vif_add_debugfs,
 	.link_sta_add_debugfs = iwl_mvm_link_sta_add_debugfs,
 #endif
 	.set_hw_timestamp = iwl_mvm_set_hw_timestamp,

drivers/net/wireless/intel/iwlwifi/mvm/mld-mac80211.c

@@ -107,7 +107,7 @@ static int iwl_mvm_mld_mac_add_interface(struct ieee80211_hw *hw,
 		ieee80211_hw_set(mvm->hw, RX_INCLUDES_FCS);
 	}
 
-	iwl_mvm_vif_dbgfs_register(mvm, vif);
+	iwl_mvm_vif_dbgfs_add_link(mvm, vif);
 
 	if (!test_bit(IWL_MVM_STATUS_IN_HW_RESTART, &mvm->status) &&
 	    vif->type == NL80211_IFTYPE_STATION && !vif->p2p &&
@@ -168,7 +168,7 @@ static void iwl_mvm_mld_mac_remove_interface(struct ieee80211_hw *hw,
 	if (vif->bss_conf.ftm_responder)
 		memset(&mvm->ftm_resp_stats, 0, sizeof(mvm->ftm_resp_stats));
 
-	iwl_mvm_vif_dbgfs_clean(mvm, vif);
+	iwl_mvm_vif_dbgfs_rm_link(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.
@@ -1209,6 +1209,7 @@ const struct ieee80211_ops iwl_mvm_mld_hw_ops = {
 	.abort_pmsr = iwl_mvm_abort_pmsr,
 
 #ifdef CONFIG_IWLWIFI_DEBUGFS
+	.vif_add_debugfs = iwl_mvm_vif_add_debugfs,
 	.link_sta_add_debugfs = iwl_mvm_link_sta_add_debugfs,
 #endif
 	.set_hw_timestamp = iwl_mvm_set_hw_timestamp,

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

@@ -2048,18 +2048,19 @@ void iwl_mvm_rx_umac_scan_iter_complete_notif(struct iwl_mvm *mvm,
 /* MVM debugfs */
 #ifdef CONFIG_IWLWIFI_DEBUGFS
 void iwl_mvm_dbgfs_register(struct iwl_mvm *mvm);
-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_mvm_vif_add_debugfs(struct ieee80211_hw *hw, struct ieee80211_vif *vif);
+void iwl_mvm_vif_dbgfs_add_link(struct iwl_mvm *mvm, struct ieee80211_vif *vif);
+void iwl_mvm_vif_dbgfs_rm_link(struct iwl_mvm *mvm, struct ieee80211_vif *vif);
 #else
 static inline void iwl_mvm_dbgfs_register(struct iwl_mvm *mvm)
 {
 }
 static inline void
-iwl_mvm_vif_dbgfs_register(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
+iwl_mvm_vif_dbgfs_add_link(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
 {
 }
 static inline void
-iwl_mvm_vif_dbgfs_clean(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
+iwl_mvm_vif_dbgfs_rm_link(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
 {
 }
 #endif /* CONFIG_IWLWIFI_DEBUGFS */