usb: gadget: f_rndis: add configfs support

f_rndis learns about configfs so we can, eventually,
remove in-kernel gadget drivers.

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/Documentation/ABI/testing/configfs-usb-gadget-rndis b/Documentation/ABI/testing/configfs-usb-gadget-rndis
new file mode 100644 (file)
index 0000000..ff127dd
--- /dev/null
+++ b/Documentation/ABI/testing/configfs-usb-gadget-rndis
@@ -0,0 +1,14 @@
+What:          /config/usb-gadget/gadget/functions/rndis.name
+Date:          May 2013
+KenelVersion:  3.11
+Description:
+               The attributes:
+
+               ifname          - network device interface name associated with
+                               this function instance
+               qmult           - queue length multiplier for high and
+                               super speed
+               host_addr       - MAC address of host's end of this
+                               Ethernet over USB link
+               dev_addr        - MAC address of device's end of this
+                               Ethernet over USB link

diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index 19373a300ec4fae633539364cde6949d560fbc8a..b6cd4bd74cb234f3f6eafa3208366579affbb054 100644 (file)
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -560,6 +560,22 @@ config USB_CONFIGFS_ECM_SUBSET
          On hardware that can't implement the full protocol,
          a simple CDC subset is used, placing fewer demands on USB.
 
+config USB_CONFIGFS_RNDIS
+       bool "RNDIS"
+       depends on USB_CONFIGFS
+       depends on NET
+       select USB_U_ETHER
+       select USB_F_RNDIS
+       help
+          Microsoft Windows XP bundles the "Remote NDIS" (RNDIS) protocol,
+          and Microsoft provides redistributable binary RNDIS drivers for
+          older versions of Windows.
+
+          To make MS-Windows work with this, use Documentation/usb/linux.inf
+          as the "driver info file".  For versions of MS-Windows older than
+          XP, you'll need to download drivers from Microsoft's website; a URL
+          is given in comments found in that info file.
+
 config USB_CONFIGFS_EEM
        bool "Ethernet Emulation Model (EEM)"
        depends on USB_CONFIGFS

diff --git a/drivers/usb/gadget/f_rndis.c b/drivers/usb/gadget/f_rndis.c
index 4045ca24e7c8e6dc0c9e007e69cb34a41eb0a62d..191df35ae69d04e31c6fc70ac7d76f2b4ff83be3 100644 (file)
--- a/drivers/usb/gadget/f_rndis.c
+++ b/drivers/usb/gadget/f_rndis.c
@@ -24,6 +24,7 @@
 #include <linux/atomic.h>
 
 #include "u_ether.h"
+#include "u_ether_configfs.h"
 #include "u_rndis.h"
 #include "rndis.h"
 
@@ -903,6 +904,41 @@ void rndis_borrow_net(struct usb_function_instance *f, struct net_device *net)
 }
 EXPORT_SYMBOL(rndis_borrow_net);
 
+static inline struct f_rndis_opts *to_f_rndis_opts(struct config_item *item)
+{
+       return container_of(to_config_group(item), struct f_rndis_opts,
+                           func_inst.group);
+}
+
+/* f_rndis_item_ops */
+USB_ETHERNET_CONFIGFS_ITEM(rndis);
+
+/* f_rndis_opts_dev_addr */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(rndis);
+
+/* f_rndis_opts_host_addr */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(rndis);
+
+/* f_rndis_opts_qmult */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(rndis);
+
+/* f_rndis_opts_ifname */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(rndis);
+
+static struct configfs_attribute *rndis_attrs[] = {
+       &f_rndis_opts_dev_addr.attr,
+       &f_rndis_opts_host_addr.attr,
+       &f_rndis_opts_qmult.attr,
+       &f_rndis_opts_ifname.attr,
+       NULL,
+};
+
+static struct config_item_type rndis_func_type = {
+       .ct_item_ops    = &rndis_item_ops,
+       .ct_attrs       = rndis_attrs,
+       .ct_owner       = THIS_MODULE,
+};
+
 static void rndis_free_inst(struct usb_function_instance *f)
 {
        struct f_rndis_opts *opts;
@@ -924,22 +960,30 @@ static struct usb_function_instance *rndis_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 = rndis_free_inst;
        opts->net = gether_setup_default();
        if (IS_ERR(opts->net))
                return ERR_CAST(opts->net);
 
+       config_group_init_type_name(&opts->func_inst.group, "",
+                                   &rndis_func_type);
+
        return &opts->func_inst;
 }
 
 static void rndis_free(struct usb_function *f)
 {
        struct f_rndis *rndis;
+       struct f_rndis_opts *opts;
 
        rndis = func_to_rndis(f);
        rndis_deregister(rndis->config);
+       opts = container_of(f->fi, struct f_rndis_opts, func_inst);
        kfree(rndis);
+       mutex_lock(&opts->lock);
+       opts->refcnt--;
+       mutex_unlock(&opts->lock);
 }
 
 static void rndis_unbind(struct usb_configuration *c, struct usb_function *f)
@@ -964,12 +1008,15 @@ static struct usb_function *rndis_alloc(struct usb_function_instance *fi)
                return ERR_PTR(-ENOMEM);
 
        opts = container_of(fi, struct f_rndis_opts, func_inst);
+       mutex_lock(&opts->lock);
+       opts->refcnt++;
 
        gether_get_host_addr_u8(opts->net, rndis->ethaddr);
        rndis->vendorID = opts->vendor_id;
        rndis->manufacturer = opts->manufacturer;
 
        rndis->port.ioport = netdev_priv(opts->net);
+       mutex_unlock(&opts->lock);
        /* RNDIS activates when the host changes this filter */
        rndis->port.cdc_filter = 0;
 

diff --git a/drivers/usb/gadget/u_rndis.h b/drivers/usb/gadget/u_rndis.h
index d274df56ce757a831f44ea4054a81f5daed83d6a..c62ba82e96003593b7366df34165a423b38f46a0 100644 (file)
--- a/drivers/usb/gadget/u_rndis.h
+++ b/drivers/usb/gadget/u_rndis.h
@@ -25,6 +25,15 @@ struct f_rndis_opts {
        struct net_device               *net;
        bool                            bound;
        bool                            borrowed_net;
+
+       /*
+        * 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;
 };
 
 void rndis_borrow_net(struct usb_function_instance *f, struct net_device *net);