Merge remote-tracking branch 'sm8350/lineage-20' into lineage-22.2

* sm8350/lineage-20:
  usb: gadget: f_ncm: Always set current gadget in ncm_bind()
  FROMGIT: usb: gadget: u_ether: support configuring interface names.
  usb: gadget: f_ncm: Revert to upstream

Change-Id: I22e19c48a42cc4f436131de72b59dfb87aca6e3c

Documentation/usb/gadget-testing.rst

@@ -91,9 +91,9 @@ The ECM function provides these attributes in its function directory:
 
 and after creating the functions/ecm.<instance name> they contain default
 values: qmult is 5, dev_addr and host_addr are randomly selected.
-Except for ifname they can be written to until the function is linked to a
-configuration. The ifname is read-only and contains the name of the interface
-which was assigned by the net core, e. g. usb0.
+The ifname can be written to if the function is not bound. A write must be an
+interface pattern such as "usb%d", which will cause the net core to choose the
+next free usbX interface. By default, it is set to "usb%d".
 
 Testing the ECM function
 ------------------------
@@ -131,9 +131,9 @@ The ECM subset function provides these attributes in its function directory:
 
 and after creating the functions/ecm.<instance name> they contain default
 values: qmult is 5, dev_addr and host_addr are randomly selected.
-Except for ifname they can be written to until the function is linked to a
-configuration. The ifname is read-only and contains the name of the interface
-which was assigned by the net core, e. g. usb0.
+The ifname can be written to if the function is not bound. A write must be an
+interface pattern such as "usb%d", which will cause the net core to choose the
+next free usbX interface. By default, it is set to "usb%d".
 
 Testing the ECM subset function
 -------------------------------
@@ -171,9 +171,9 @@ The EEM function provides these attributes in its function directory:
 
 and after creating the functions/eem.<instance name> they contain default
 values: qmult is 5, dev_addr and host_addr are randomly selected.
-Except for ifname they can be written to until the function is linked to a
-configuration. The ifname is read-only and contains the name of the interface
-which was assigned by the net core, e. g. usb0.
+The ifname can be written to if the function is not bound. A write must be an
+interface pattern such as "usb%d", which will cause the net core to choose the
+next free usbX interface. By default, it is set to "usb%d".
 
 Testing the EEM function
 ------------------------
@@ -453,9 +453,9 @@ The NCM function provides these attributes in its function directory:
 
 and after creating the functions/ncm.<instance name> they contain default
 values: qmult is 5, dev_addr and host_addr are randomly selected.
-Except for ifname they can be written to until the function is linked to a
-configuration. The ifname is read-only and contains the name of the interface
-which was assigned by the net core, e. g. usb0.
+The ifname can be written to if the function is not bound. A write must be an
+interface pattern such as "usb%d", which will cause the net core to choose the
+next free usbX interface. By default, it is set to "usb%d".
 
 Testing the NCM function
 ------------------------
@@ -591,9 +591,9 @@ The RNDIS function provides these attributes in its function directory:
 
 and after creating the functions/rndis.<instance name> they contain default
 values: qmult is 5, dev_addr and host_addr are randomly selected.
-Except for ifname they can be written to until the function is linked to a
-configuration. The ifname is read-only and contains the name of the interface
-which was assigned by the net core, e. g. usb0.
+The ifname can be written to if the function is not bound. A write must be an
+interface pattern such as "usb%d", which will cause the net core to choose the
+next free usbX interface. By default, it is set to "usb%d".
 
 Testing the RNDIS function
 --------------------------

drivers/usb/gadget/function/f_ncm.c

@@ -1461,47 +1461,22 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f)
 		f->os_desc_table[0].os_desc = &ncm_opts->ncm_os_desc;
 	}
 
-	/*
-	 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
-	 * configurations are bound in sequence with list_for_each_entry,
-	 * in each configuration its functions are bound in sequence
-	 * with list_for_each_entry, so we assume no race condition
-	 * with regard to ncm_opts->bound access
-	 */
-	if (!ncm_opts->bound) {
-		mutex_lock(&ncm_opts->lock);
-		ncm_opts->net = gether_setup_default();
-		if (IS_ERR(ncm_opts->net)) {
-			status = PTR_ERR(ncm_opts->net);
-			mutex_unlock(&ncm_opts->lock);
-			goto error;
-		}
-		gether_set_gadget(ncm_opts->net, cdev->gadget);
+	mutex_lock(&ncm_opts->lock);
+	gether_set_gadget(ncm_opts->net, cdev->gadget);
+	if (!ncm_opts->bound)
 		status = gether_register_netdev(ncm_opts->net);
-		mutex_unlock(&ncm_opts->lock);
-		if (status) {
-			free_netdev(ncm_opts->net);
-			goto error;
-		}
-		ncm_opts->bound = true;
-	}
+	mutex_unlock(&ncm_opts->lock);
 
-	/* export host's Ethernet address in CDC format */
-	status = gether_get_host_addr_cdc(ncm_opts->net, ncm->ethaddr,
-				      sizeof(ncm->ethaddr));
-	if (status < 12) { /* strlen("01234567890a") */
-		ERROR(cdev, "%s: failed to get host eth addr, err %d\n",
-		__func__, status);
-		status = -EINVAL;
-		goto netdev_cleanup;
-	}
-	ncm->port.ioport = netdev_priv(ncm_opts->net);
+	if (status)
+		goto fail;
+
+	ncm_opts->bound = true;
 
 	us = usb_gstrings_attach(cdev, ncm_strings,
 				 ARRAY_SIZE(ncm_string_defs));
 	if (IS_ERR(us)) {
 		status = PTR_ERR(us);
-		goto netdev_cleanup;
+		goto fail;
 	}
 	ncm_control_intf.iInterface = us[STRING_CTRL_IDX].id;
 	ncm_data_nop_intf.iInterface = us[STRING_DATA_IDX].id;
@@ -1609,10 +1584,7 @@ fail:
 		kfree(ncm->notify_req->buf);
 		usb_ep_free_request(ncm->notify, ncm->notify_req);
 	}
-netdev_cleanup:
-	gether_cleanup(netdev_priv(ncm_opts->net));
 
-error:
 	ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
 
 	return status;
@@ -1660,7 +1632,8 @@ static void ncm_free_inst(struct usb_function_instance *f)
 	opts = container_of(f, struct f_ncm_opts, func_inst);
 	if (opts->bound)
 		gether_cleanup(netdev_priv(opts->net));
-
+	else
+		free_netdev(opts->net);
 	kfree(opts->ncm_interf_group);
 	kfree(opts);
 }
@@ -1679,6 +1652,12 @@ static struct usb_function_instance *ncm_alloc_inst(void)
 
 	mutex_init(&opts->lock);
 	opts->func_inst.free_func_inst = ncm_free_inst;
+	opts->net = gether_setup_default();
+	if (IS_ERR(opts->net)) {
+		struct net_device *net = opts->net;
+		kfree(opts);
+		return ERR_CAST(net);
+	}
 	INIT_LIST_HEAD(&opts->ncm_os_desc.ext_prop);
 
 	descs[0] = &opts->ncm_os_desc;
@@ -1713,13 +1692,9 @@ static void ncm_free(struct usb_function *f)
 static void ncm_unbind(struct usb_configuration *c, struct usb_function *f)
 {
 	struct f_ncm *ncm = func_to_ncm(f);
-	struct f_ncm_opts *opts = container_of(f->fi, struct f_ncm_opts,
-					func_inst);
 
 	DBG(c->cdev, "ncm unbind\n");
 
-	opts->bound = false;
-
 	hrtimer_cancel(&ncm->task_timer);
 
 	kfree(f->os_desc_table);
@@ -1735,14 +1710,13 @@ static void ncm_unbind(struct usb_configuration *c, struct usb_function *f)
 
 	kfree(ncm->notify_req->buf);
 	usb_ep_free_request(ncm->notify, ncm->notify_req);
-
-	gether_cleanup(netdev_priv(opts->net));
 }
 
 static struct usb_function *ncm_alloc(struct usb_function_instance *fi)
 {
 	struct f_ncm		*ncm;
 	struct f_ncm_opts	*opts;
+	int status;
 
 	/* allocate and initialize one new instance */
 	ncm = kzalloc(sizeof(*ncm), GFP_KERNEL);
@@ -1752,9 +1726,20 @@ static struct usb_function *ncm_alloc(struct usb_function_instance *fi)
 	opts = container_of(fi, struct f_ncm_opts, func_inst);
 	mutex_lock(&opts->lock);
 	opts->refcnt++;
+
+	/* export host's Ethernet address in CDC format */
+	status = gether_get_host_addr_cdc(opts->net, ncm->ethaddr,
+				      sizeof(ncm->ethaddr));
+	if (status < 12) { /* strlen("01234567890a") */
+		kfree(ncm);
+		mutex_unlock(&opts->lock);
+		return ERR_PTR(-EINVAL);
+	}
 	ncm_string_defs[STRING_MAC_IDX].s = ncm->ethaddr;
+
 	spin_lock_init(&ncm->lock);
 	ncm_reset_values(ncm);
+	ncm->port.ioport = netdev_priv(opts->net);
 	mutex_unlock(&opts->lock);
 	ncm->port.is_fixed = true;
 	ncm->port.supports_multi_frame = true;

drivers/usb/gadget/function/u_ether.c

@@ -82,6 +82,7 @@ struct eth_dev {
 
 	bool			zlp;
 	bool			no_skb_reserve;
+	bool			ifname_set;
 	u8			host_mac[ETH_ALEN];
 	u8			dev_mac[ETH_ALEN];
 };
@@ -979,15 +980,45 @@ EXPORT_SYMBOL_GPL(gether_get_qmult);
 
 int gether_get_ifname(struct net_device *net, char *name, int len)
 {
+	struct eth_dev *dev = netdev_priv(net);
 	int ret;
 
 	rtnl_lock();
-	ret = scnprintf(name, len, "%s\n", netdev_name(net));
+	ret = scnprintf(name, len, "%s\n",
+			dev->ifname_set ? net->name : netdev_name(net));
 	rtnl_unlock();
 	return ret;
 }
 EXPORT_SYMBOL_GPL(gether_get_ifname);
 
+int gether_set_ifname(struct net_device *net, const char *name, int len)
+{
+	struct eth_dev *dev = netdev_priv(net);
+	char tmp[IFNAMSIZ];
+	const char *p;
+
+	if (name[len - 1] == '\n')
+		len--;
+
+	if (len >= sizeof(tmp))
+		return -E2BIG;
+
+	strscpy(tmp, name, len + 1);
+	if (!dev_valid_name(tmp))
+		return -EINVAL;
+
+	/* Require exactly one %d, so binding will not fail with EEXIST. */
+	p = strchr(name, '%');
+	if (!p || p[1] != 'd' || strchr(p + 2, '%'))
+		return -EINVAL;
+
+	strncpy(net->name, tmp, sizeof(net->name));
+	dev->ifname_set = true;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(gether_set_ifname);
+
 /**
  * gether_cleanup - remove Ethernet-over-USB device
  * Context: may sleep

drivers/usb/gadget/function/u_ether.h

@@ -244,6 +244,18 @@ unsigned gether_get_qmult(struct net_device *net);
  */
 int gether_get_ifname(struct net_device *net, char *name, int len);
 
+/**
+ * gether_set_ifname - set an ethernet-over-usb link interface name
+ * @net: device representing this link
+ * @name: new interface name
+ * @len: length of @name
+ *
+ * This sets the interface name of this ethernet-over-usb link.
+ * A single terminating newline, if any, is ignored.
+ * Returns zero on success, else negative errno.
+ */
+int gether_set_ifname(struct net_device *net, const char *name, int len);
+
 void gether_cleanup(struct eth_dev *dev);
 
 /* connect/disconnect is handled by individual functions */

drivers/usb/gadget/function/u_ether_configfs.h

@@ -32,11 +32,6 @@
 		struct f_##_f_##_opts *opts = to_f_##_f_##_opts(item);	\
 		int result;						\
 									\
-		if (opts->bound == false) {		\
-			pr_err("Gadget function do not bind yet.\n");	\
-			return -ENODEV;			\
-		}							\
-									\
 		mutex_lock(&opts->lock);				\
 		result = gether_get_dev_addr(opts->net, page, PAGE_SIZE); \
 		mutex_unlock(&opts->lock);				\
@@ -50,11 +45,6 @@
 		struct f_##_f_##_opts *opts = to_f_##_f_##_opts(item);	\
 		int ret;						\
 									\
-		if (opts->bound == false) {		\
-			pr_err("Gadget function do not bind yet.\n");	\
-			return -ENODEV;			\
-		}							\
-									\
 		mutex_lock(&opts->lock);				\
 		if (opts->refcnt) {					\
 			mutex_unlock(&opts->lock);			\
@@ -77,11 +67,6 @@
 		struct f_##_f_##_opts *opts = to_f_##_f_##_opts(item);	\
 		int result;						\
 									\
-		if (opts->bound == false) {		\
-			pr_err("Gadget function do not bind yet.\n");	\
-			return -ENODEV;			\
-		}							\
-									\
 		mutex_lock(&opts->lock);				\
 		result = gether_get_host_addr(opts->net, page, PAGE_SIZE); \
 		mutex_unlock(&opts->lock);				\
@@ -95,11 +80,6 @@
 		struct f_##_f_##_opts *opts = to_f_##_f_##_opts(item);	\
 		int ret;						\
 									\
-		if (opts->bound == false) {		\
-			pr_err("Gadget function do not bind yet.\n");	\
-			return -ENODEV;			\
-		}							\
-									\
 		mutex_lock(&opts->lock);				\
 		if (opts->refcnt) {					\
 			mutex_unlock(&opts->lock);			\
@@ -122,11 +102,6 @@
 		struct f_##_f_##_opts *opts = to_f_##_f_##_opts(item);	\
 		unsigned qmult;						\
 									\
-		if (opts->bound == false) {		\
-			pr_err("Gadget function do not bind yet.\n");	\
-			return -ENODEV;			\
-		}							\
-									\
 		mutex_lock(&opts->lock);				\
 		qmult = gether_get_qmult(opts->net);			\
 		mutex_unlock(&opts->lock);				\
@@ -140,11 +115,6 @@
 		u8 val;							\
 		int ret;						\
 									\
-		if (opts->bound == false) {		\
-			pr_err("Gadget function do not bind yet.\n");	\
-			return -ENODEV;			\
-		}							\
-									\
 		mutex_lock(&opts->lock);				\
 		if (opts->refcnt) {					\
 			ret = -EBUSY;					\
@@ -171,11 +141,6 @@ out:									\
 		struct f_##_f_##_opts *opts = to_f_##_f_##_opts(item);	\
 		int ret;						\
 									\
-		if (opts->bound == false) {		\
-			pr_err("Gadget function do not bind yet.\n");	\
-			return -ENODEV;			\
-		}							\
-									\
 		mutex_lock(&opts->lock);				\
 		ret = gether_get_ifname(opts->net, page, PAGE_SIZE);	\
 		mutex_unlock(&opts->lock);				\
@@ -183,7 +148,20 @@ out:									\
 		return ret;						\
 	}								\
 									\
-	CONFIGFS_ATTR_RO(_f_##_opts_, ifname)
+	static ssize_t _f_##_opts_ifname_store(struct config_item *item, \
+					       const char *page, size_t len)\
+	{								\
+		struct f_##_f_##_opts *opts = to_f_##_f_##_opts(item);	\
+		int ret = -EBUSY;					\
+									\
+		mutex_lock(&opts->lock);				\
+		if (!opts->refcnt)					\
+			ret = gether_set_ifname(opts->net, page, len);	\
+		mutex_unlock(&opts->lock);				\
+		return ret ?: len;					\
+	}								\
+									\
+	CONFIGFS_ATTR(_f_##_opts_, ifname)
 
 #define USB_ETHER_CONFIGFS_ITEM_ATTR_U8_RW(_f_, _n_)			\
 	static ssize_t _f_##_opts_##_n_##_show(struct config_item *item,\