usb: gadget: f_ecm: add configfs support

f_ecm learns about our new configfs-based binding.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

diff --git a/drivers/usb/gadget/f_ecm.c b/drivers/usb/gadget/f_ecm.c
index 22d19483e101352f471c4f3f1c389dbb85016b7d..fcafe1af45850f5ee3d9906efb91d4beefcccefd 100644 (file)
--- a/drivers/usb/gadget/f_ecm.c
+++ b/drivers/usb/gadget/f_ecm.c
@@ -19,6 +19,7 @@
 #include <linux/etherdevice.h>
 
 #include "u_ether.h"
+#include "u_ether_configfs.h"
 #include "u_ecm.h"
 
 
@@ -706,8 +707,10 @@ ecm_bind(struct usb_configuration *c, struct usb_function *f)
         * with regard to ecm_opts->bound access
         */
        if (!ecm_opts->bound) {
+               mutex_lock(&ecm_opts->lock);
                gether_set_gadget(ecm_opts->net, cdev->gadget);
                status = gether_register_netdev(ecm_opts->net);
+               mutex_unlock(&ecm_opts->lock);
                if (status)
                        return status;
                ecm_opts->bound = true;
@@ -899,6 +902,41 @@ ecm_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN],
 
 #else
 
+static inline struct f_ecm_opts *to_f_ecm_opts(struct config_item *item)
+{
+       return container_of(to_config_group(item), struct f_ecm_opts,
+                           func_inst.group);
+}
+
+/* f_ecm_item_ops */
+USB_ETHERNET_CONFIGFS_ITEM(ecm);
+
+/* f_ecm_opts_dev_addr */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(ecm);
+
+/* f_ecm_opts_host_addr */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(ecm);
+
+/* f_ecm_opts_qmult */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(ecm);
+
+/* f_ecm_opts_ifname */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(ecm);
+
+static struct configfs_attribute *ecm_attrs[] = {
+       &f_ecm_opts_dev_addr.attr,
+       &f_ecm_opts_host_addr.attr,
+       &f_ecm_opts_qmult.attr,
+       &f_ecm_opts_ifname.attr,
+       NULL,
+};
+
+static struct config_item_type ecm_func_type = {
+       .ct_item_ops    = &ecm_item_ops,
+       .ct_attrs       = ecm_attrs,
+       .ct_owner       = THIS_MODULE,
+};
+
 static void ecm_free_inst(struct usb_function_instance *f)
 {
        struct f_ecm_opts *opts;
@@ -918,21 +956,28 @@ static struct usb_function_instance *ecm_alloc_inst(void)
        opts = kzalloc(sizeof(*opts), GFP_KERNEL);
        if (!opts)
                return ERR_PTR(-ENOMEM);
-
+       mutex_init(&opts->lock);
        opts->func_inst.free_func_inst = ecm_free_inst;
        opts->net = gether_setup_default();
        if (IS_ERR(opts->net))
                return ERR_PTR(PTR_ERR(opts->net));
 
+       config_group_init_type_name(&opts->func_inst.group, "", &ecm_func_type);
+
        return &opts->func_inst;
 }
 
 static void ecm_free(struct usb_function *f)
 {
        struct f_ecm *ecm;
+       struct f_ecm_opts *opts;
 
        ecm = func_to_ecm(f);
+       opts = container_of(f->fi, struct f_ecm_opts, func_inst);
        kfree(ecm);
+       mutex_lock(&opts->lock);
+       opts->refcnt--;
+       mutex_unlock(&opts->lock);
 }
 
 static void ecm_unbind(struct usb_configuration *c, struct usb_function *f)
@@ -959,6 +1004,8 @@ struct usb_function *ecm_alloc(struct usb_function_instance *fi)
                return ERR_PTR(-ENOMEM);
 
        opts = container_of(fi, struct f_ecm_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, ecm->ethaddr,
@@ -970,6 +1017,7 @@ struct usb_function *ecm_alloc(struct usb_function_instance *fi)
        ecm_string_defs[1].s = ecm->ethaddr;
 
        ecm->port.ioport = netdev_priv(opts->net);
+       mutex_unlock(&opts->lock);
        ecm->port.cdc_filter = DEFAULT_FILTER;
 
        ecm->port.func.name = "cdc_ethernet";

diff --git a/drivers/usb/gadget/u_ecm.h b/drivers/usb/gadget/u_ecm.h
index 99b6b995988f4b0f2b3f5b24ee5269eac914f2d1..262cc03cc2c01cb2a739310f53814e0ad6691d7c 100644 (file)
--- a/drivers/usb/gadget/u_ecm.h
+++ b/drivers/usb/gadget/u_ecm.h
@@ -22,6 +22,15 @@ struct f_ecm_opts {
        struct usb_function_instance    func_inst;
        struct net_device               *net;
        bool                            bound;
+
+       /*
+        * Read/write access to configfs attributes is handled by configfs.
+        *
+        * This is to protect the data from concurrent access by read/write
+        * and create symlink/remove symlink.
+        */
+       struct mutex                    lock;
+       int                             refcnt;
 };
 
 #endif /* U_ECM_H */