iwlwifi: rework the iwlwifi debugfs structure

The generic part of the driver now creates all debugfs
directories. It creates a root directory directly in
the the root of the debugfs filesystem and within that
directories for each device, named after the device ID
of the devices iwlwifi is attached to.

In the cfg80211/mac80211 directory there's now a link
to the toplevel iwlwifi debugfs directory to make it
easier to find the debugfs files.

Signed-off-by: Meenakshi Venkataraman <meenakshi.venkataraman@intel.com>
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/iwlwifi/iwl-drv.c

@@ -101,6 +101,10 @@ MODULE_VERSION(DRV_VERSION);
 MODULE_AUTHOR(DRV_COPYRIGHT " " DRV_AUTHOR);
 MODULE_LICENSE("GPL");
 
+#ifdef CONFIG_IWLWIFI_DEBUGFS
+static struct dentry *iwl_dbgfs_root;
+#endif
+
 /**
  * struct iwl_drv - drv common data
  * @list: list of drv structures using this opmode
@@ -126,6 +130,12 @@ struct iwl_drv {
 	char firmware_name[25];         /* name of firmware file to load */
 
 	struct completion request_firmware_complete;
+
+#ifdef CONFIG_IWLWIFI_DEBUGFS
+	struct dentry *dbgfs_drv;
+	struct dentry *dbgfs_trans;
+	struct dentry *dbgfs_op_mode;
+#endif
 };
 
 #define DVM_OP_MODE	0
@@ -760,6 +770,50 @@ static int validate_sec_sizes(struct iwl_drv *drv,
 	return 0;
 }
 
+static struct iwl_op_mode *
+_iwl_op_mode_start(struct iwl_drv *drv, struct iwlwifi_opmode_table *op)
+{
+	const struct iwl_op_mode_ops *ops = op->ops;
+	struct dentry *dbgfs_dir = NULL;
+	struct iwl_op_mode *op_mode = NULL;
+
+#ifdef CONFIG_IWLWIFI_DEBUGFS
+	drv->dbgfs_op_mode = debugfs_create_dir(op->name,
+						drv->dbgfs_drv);
+	if (!drv->dbgfs_op_mode) {
+		IWL_ERR(drv,
+			"failed to create opmode debugfs directory\n");
+		return op_mode;
+	}
+	dbgfs_dir = drv->dbgfs_op_mode;
+#endif
+
+	op_mode = ops->start(drv->trans, drv->cfg, &drv->fw, dbgfs_dir);
+
+#ifdef CONFIG_IWLWIFI_DEBUGFS
+	if (!op_mode) {
+		debugfs_remove_recursive(drv->dbgfs_op_mode);
+		drv->dbgfs_op_mode = NULL;
+	}
+#endif
+
+	return op_mode;
+}
+
+static void _iwl_op_mode_stop(struct iwl_drv *drv)
+{
+	/* op_mode can be NULL if its start failed */
+	if (drv->op_mode) {
+		iwl_op_mode_stop(drv->op_mode);
+		drv->op_mode = NULL;
+
+#ifdef CONFIG_IWLWIFI_DEBUGFS
+		debugfs_remove_recursive(drv->dbgfs_op_mode);
+		drv->dbgfs_op_mode = NULL;
+#endif
+	}
+}
+
 /**
  * iwl_req_fw_callback - callback when firmware was loaded
  *
@@ -909,8 +963,7 @@ static void iwl_req_fw_callback(const struct firmware *ucode_raw, void *context)
 	list_add_tail(&drv->list, &op->drv);
 
 	if (op->ops) {
-		const struct iwl_op_mode_ops *ops = op->ops;
-		drv->op_mode = ops->start(drv->trans, drv->cfg, &drv->fw);
+		drv->op_mode = _iwl_op_mode_start(drv, op);
 
 		if (!drv->op_mode) {
 			mutex_unlock(&iwlwifi_opmode_table_mtx);
@@ -970,14 +1023,43 @@ struct iwl_drv *iwl_drv_start(struct iwl_trans *trans,
 	init_completion(&drv->request_firmware_complete);
 	INIT_LIST_HEAD(&drv->list);
 
+#ifdef CONFIG_IWLWIFI_DEBUGFS
+	/* Create the device debugfs entries. */
+	drv->dbgfs_drv = debugfs_create_dir(dev_name(trans->dev),
+					    iwl_dbgfs_root);
+
+	if (!drv->dbgfs_drv) {
+		IWL_ERR(drv, "failed to create debugfs directory\n");
+		goto err_free_drv;
+	}
+
+	/* Create transport layer debugfs dir */
+	drv->trans->dbgfs_dir = debugfs_create_dir("trans", drv->dbgfs_drv);
+
+	if (!drv->trans->dbgfs_dir) {
+		IWL_ERR(drv, "failed to create transport debugfs directory\n");
+		goto err_free_dbgfs;
+	}
+#endif
+
 	ret = iwl_request_firmware(drv, true);
 
 	if (ret) {
 		IWL_ERR(trans, "Couldn't request the fw\n");
-		kfree(drv);
-		drv = NULL;
+		goto err_fw;
 	}
 
+	return drv;
+
+err_fw:
+#ifdef CONFIG_IWLWIFI_DEBUGFS
+err_free_dbgfs:
+	debugfs_remove_recursive(drv->dbgfs_drv);
+err_free_drv:
+#endif
+	kfree(drv);
+	drv = NULL;
+
 	return drv;
 }
 
@@ -985,9 +1067,7 @@ void iwl_drv_stop(struct iwl_drv *drv)
 {
 	wait_for_completion(&drv->request_firmware_complete);
 
-	/* op_mode can be NULL if its start failed */
-	if (drv->op_mode)
-		iwl_op_mode_stop(drv->op_mode);
+	_iwl_op_mode_stop(drv);
 
 	iwl_dealloc_ucode(drv);
 
@@ -1001,6 +1081,10 @@ void iwl_drv_stop(struct iwl_drv *drv)
 		list_del(&drv->list);
 	mutex_unlock(&iwlwifi_opmode_table_mtx);
 
+#ifdef CONFIG_IWLWIFI_DEBUGFS
+	debugfs_remove_recursive(drv->dbgfs_drv);
+#endif
+
 	kfree(drv);
 }
 
@@ -1023,15 +1107,18 @@ int iwl_opmode_register(const char *name, const struct iwl_op_mode_ops *ops)
 {
 	int i;
 	struct iwl_drv *drv;
+	struct iwlwifi_opmode_table *op;
 
 	mutex_lock(&iwlwifi_opmode_table_mtx);
 	for (i = 0; i < ARRAY_SIZE(iwlwifi_opmode_table); i++) {
-		if (strcmp(iwlwifi_opmode_table[i].name, name))
+		op = &iwlwifi_opmode_table[i];
+		if (strcmp(op->name, name))
 			continue;
-		iwlwifi_opmode_table[i].ops = ops;
-		list_for_each_entry(drv, &iwlwifi_opmode_table[i].drv, list)
-			drv->op_mode = ops->start(drv->trans, drv->cfg,
-						  &drv->fw);
+		op->ops = ops;
+		/* TODO: need to handle exceptional case */
+		list_for_each_entry(drv, &op->drv, list)
+			drv->op_mode = _iwl_op_mode_start(drv, op);
+
 		mutex_unlock(&iwlwifi_opmode_table_mtx);
 		return 0;
 	}
@@ -1052,12 +1139,9 @@ void iwl_opmode_deregister(const char *name)
 		iwlwifi_opmode_table[i].ops = NULL;
 
 		/* call the stop routine for all devices */
-		list_for_each_entry(drv, &iwlwifi_opmode_table[i].drv, list) {
-			if (drv->op_mode) {
-				iwl_op_mode_stop(drv->op_mode);
-				drv->op_mode = NULL;
-			}
-		}
+		list_for_each_entry(drv, &iwlwifi_opmode_table[i].drv, list)
+			_iwl_op_mode_stop(drv);
+
 		mutex_unlock(&iwlwifi_opmode_table_mtx);
 		return;
 	}
@@ -1077,6 +1161,14 @@ static int __init iwl_drv_init(void)
 	pr_info(DRV_DESCRIPTION ", " DRV_VERSION "\n");
 	pr_info(DRV_COPYRIGHT "\n");
 
+#ifdef CONFIG_IWLWIFI_DEBUGFS
+	/* Create the root of iwlwifi debugfs subsystem. */
+	iwl_dbgfs_root = debugfs_create_dir(DRV_NAME, NULL);
+
+	if (!iwl_dbgfs_root)
+		return -EFAULT;
+#endif
+
 	return iwl_pci_register_driver();
 }
 module_init(iwl_drv_init);
@@ -1084,6 +1176,10 @@ module_init(iwl_drv_init);
 static void __exit iwl_drv_exit(void)
 {
 	iwl_pci_unregister_driver();
+
+#ifdef CONFIG_IWLWIFI_DEBUGFS
+	debugfs_remove_recursive(iwl_dbgfs_root);
+#endif
 }
 module_exit(iwl_drv_exit);