usb: gadget: f_rndis: convert to new function interface with backward compatibility

Converting rndis to the new function interface requires converting
the USB rndis' function code and its users.

This patch converts the f_rndis.c to the new function interface.

The file is now compiled into a separate usb_f_rndis.ko module.

The old function interface is provided by means of a preprocessor
conditional directives. After all users are converted, the old interface
can be removed.

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>

1 files changed, 175 insertions, 28 deletions

diff --git a/drivers/usb/gadget/f_rndis.c b/drivers/usb/gadget/f_rndis.c
index 36e8c44d8e5e..437198b6d8fa 100644
--- a/drivers/usb/gadget/f_rndis.c
+++ b/drivers/usb/gadget/f_rndis.c
@@ -17,15 +17,16 @@
 
 #include <linux/slab.h>
 #include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/device.h>
 #include <linux/etherdevice.h>
 
 #include <linux/atomic.h>
 
 #include "u_ether.h"
+#include "u_rndis.h"
 #include "rndis.h"
 
-
 /*
  * This function is an RNDIS Ethernet port -- a Microsoft protocol that's
  * been promoted instead of the standard CDC Ethernet.  The published RNDIS
@@ -655,6 +656,13 @@ static void rndis_close(struct gether *geth)
 
 /*-------------------------------------------------------------------------*/
 
+/* Some controllers can't support RNDIS ... */
+static inline bool can_support_rndis(struct usb_configuration *c)
+{
+        /* everything else is *presumably* fine */
+        return true;
+}
+
 /* ethernet function driver setup/binding */
 
 static int
@@ -665,6 +673,45 @@ rndis_bind(struct usb_configuration *c, struct usb_function *f)
         int                     status;
         struct usb_ep           *ep;
 
+#ifndef USB_FRNDIS_INCLUDED
+        struct f_rndis_opts *rndis_opts;
+
+        if (!can_support_rndis(c))
+                return -EINVAL;
+
+        rndis_opts = container_of(f->fi, struct f_rndis_opts, func_inst);
+
+        /*
+         * 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 rndis_opts->bound access
+         */
+        if (!rndis_opts->bound) {
+                gether_set_gadget(rndis_opts->net, cdev->gadget);
+                status = gether_register_netdev(rndis_opts->net);
+                if (status)
+                        return status;
+                rndis_opts->bound = true;
+        }
+#endif
+
+        if (rndis_string_defs[0].id == 0) {
+                /* ... and setup RNDIS itself */
+                status = rndis_init();
+                if (status < 0)
+                        return status;
+
+                status = usb_string_ids_tab(c->cdev, rndis_string_defs);
+                if (status)
+                        return status;
+
+                rndis_control_intf.iInterface = rndis_string_defs[0].id;
+                rndis_data_intf.iInterface = rndis_string_defs[1].id;
+                rndis_iad_descriptor.iFunction = rndis_string_defs[2].id;
+        }
+
         /* allocate instance-specific interface IDs */
         status = usb_interface_id(c, f);
         if (status < 0)
@@ -741,10 +788,12 @@ rndis_bind(struct usb_configuration *c, struct usb_function *f)
         rndis->port.open = rndis_open;
         rndis->port.close = rndis_close;
 
+#ifdef USB_FRNDIS_INCLUDED
         status = rndis_register(rndis_response_available, rndis);
         if (status < 0)
                 goto fail;
         rndis->config = status;
+#endif
 
         rndis_set_param_medium(rndis->config, RNDIS_MEDIUM_802_3, 0);
         rndis_set_host_mac(rndis->config, rndis->ethaddr);
@@ -787,8 +836,10 @@ fail:
         return status;
 }
 
+#ifdef USB_FRNDIS_INCLUDED
+
 static void
-rndis_unbind(struct usb_configuration *c, struct usb_function *f)
+rndis_old_unbind(struct usb_configuration *c, struct usb_function *f)
 {
         struct f_rndis          *rndis = func_to_rndis(f);
 
@@ -804,13 +855,6 @@ rndis_unbind(struct usb_configuration *c, struct usb_function *f)
         kfree(rndis);
 }
 
-/* Some controllers can't support RNDIS ... */
-static inline bool can_support_rndis(struct usb_configuration *c)
-{
-        /* everything else is *presumably* fine */
-        return true;
-}
-
 int
 rndis_bind_config_vendor(struct usb_configuration *c, u8 ethaddr[ETH_ALEN],
                 u32 vendorID, const char *manufacturer, struct eth_dev *dev)
@@ -818,24 +862,6 @@ rndis_bind_config_vendor(struct usb_configuration *c, u8 ethaddr[ETH_ALEN],
         struct f_rndis  *rndis;
         int             status;
 
-        if (!can_support_rndis(c) || !ethaddr)
-                return -EINVAL;
-
-        if (rndis_string_defs[0].id == 0) {
-                /* ... and setup RNDIS itself */
-                status = rndis_init();
-                if (status < 0)
-                        return status;
-
-                status = usb_string_ids_tab(c->cdev, rndis_string_defs);
-                if (status)
-                        return status;
-
-                rndis_control_intf.iInterface = rndis_string_defs[0].id;
-                rndis_data_intf.iInterface = rndis_string_defs[1].id;
-                rndis_iad_descriptor.iFunction = rndis_string_defs[2].id;
-        }
-
         /* allocate and initialize one new instance */
         status = -ENOMEM;
         rndis = kzalloc(sizeof *rndis, GFP_KERNEL);
@@ -859,7 +885,7 @@ rndis_bind_config_vendor(struct usb_configuration *c, u8 ethaddr[ETH_ALEN],
         rndis->port.func.strings = rndis_strings;
         /* descriptors are per-instance copies */
         rndis->port.func.bind = rndis_bind;
-        rndis->port.func.unbind = rndis_unbind;
+        rndis->port.func.unbind = rndis_old_unbind;
         rndis->port.func.set_alt = rndis_set_alt;
         rndis->port.func.setup = rndis_setup;
         rndis->port.func.disable = rndis_disable;
@@ -872,3 +898,124 @@ fail:
         }
         return status;
 }
+
+#else
+
+void rndis_borrow_net(struct usb_function_instance *f, struct net_device *net)
+{
+        struct f_rndis_opts *opts;
+
+        opts = container_of(f, struct f_rndis_opts, func_inst);
+        if (opts->bound)
+                gether_cleanup(netdev_priv(opts->net));
+        else
+                free_netdev(opts->net);
+        opts->borrowed_net = opts->bound = true;
+        opts->net = net;
+}
+EXPORT_SYMBOL(rndis_borrow_net);
+
+static void rndis_free_inst(struct usb_function_instance *f)
+{
+        struct f_rndis_opts *opts;
+
+        opts = container_of(f, struct f_rndis_opts, func_inst);
+        if (!opts->borrowed_net) {
+                if (opts->bound)
+                        gether_cleanup(netdev_priv(opts->net));
+                else
+                        free_netdev(opts->net);
+        }
+        kfree(opts);
+}
+
+static struct usb_function_instance *rndis_alloc_inst(void)
+{
+        struct f_rndis_opts *opts;
+
+        opts = kzalloc(sizeof(*opts), GFP_KERNEL);
+        if (!opts)
+                return ERR_PTR(-ENOMEM);
+
+        opts->func_inst.free_func_inst = rndis_free_inst;
+        opts->net = gether_setup_default();
+        if (IS_ERR(opts->net))
+                return ERR_CAST(opts->net);
+
+        return &opts->func_inst;
+}
+
+static void rndis_free(struct usb_function *f)
+{
+        struct f_rndis *rndis;
+
+        rndis = func_to_rndis(f);
+        rndis_deregister(rndis->config);
+        kfree(rndis);
+}
+
+static void rndis_unbind(struct usb_configuration *c, struct usb_function *f)
+{
+        struct f_rndis          *rndis = func_to_rndis(f);
+
+        rndis_exit();
+        rndis_string_defs[0].id = 0;
+        usb_free_all_descriptors(f);
+
+        kfree(rndis->notify_req->buf);
+        usb_ep_free_request(rndis->notify, rndis->notify_req);
+}
+
+static struct usb_function *rndis_alloc(struct usb_function_instance *fi)
+{
+        struct f_rndis  *rndis;
+        struct f_rndis_opts *opts;
+        int status;
+
+        /* allocate and initialize one new instance */
+        rndis = kzalloc(sizeof(*rndis), GFP_KERNEL);
+        if (!rndis) {
+                rndis_exit();
+                return ERR_PTR(-ENOMEM);
+        }
+
+        opts = container_of(fi, struct f_rndis_opts, func_inst);
+
+        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);
+        /* RNDIS activates when the host changes this filter */
+        rndis->port.cdc_filter = 0;
+
+        /* RNDIS has special (and complex) framing */
+        rndis->port.header_len = sizeof(struct rndis_packet_msg_type);
+        rndis->port.wrap = rndis_add_header;
+        rndis->port.unwrap = rndis_rm_hdr;
+
+        rndis->port.func.name = "rndis";
+        rndis->port.func.strings = rndis_strings;
+        /* descriptors are per-instance copies */
+        rndis->port.func.bind = rndis_bind;
+        rndis->port.func.unbind = rndis_unbind;
+        rndis->port.func.set_alt = rndis_set_alt;
+        rndis->port.func.setup = rndis_setup;
+        rndis->port.func.disable = rndis_disable;
+        rndis->port.func.free_func = rndis_free;
+
+        status = rndis_register(rndis_response_available, rndis);
+        if (status < 0) {
+                kfree(rndis);
+                return ERR_PTR(status);
+        }
+        rndis->config = status;
+
+        return &rndis->port.func;
+}
+
+DECLARE_USB_FUNCTION_INIT(rndis, rndis_alloc_inst, rndis_alloc);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David Brownell");
+
+#endif