usb: gadget: constify the struct device_type usage

Since commit aed65af1cc2f ("drivers: make device_type const"), the driver
core can properly handle constant struct device_type. Move the gadget_type
variable to be a constant structure as well, placing it into read-only
memory which can not be modified at runtime.

Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Link: https://lore.kernel.org/r/20240218-device_cleanup-usb-v1-3-77423c4da262@marliere.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: u_ether: Re-attach netif device to mirror detachment

In 6.7-rc1, there was a netif_device_detach call added to the
gether_disconnect function. This clears the __LINK_STATE_PRESENT bit of
the netif device and suppresses pings (ICMP messages) and TCP connection
requests from the connected host. If userspace temporarily disconnects
the gadget, such as by temporarily removing configuration in the gadget
configfs interface, network activity should continue to be processed
when the gadget is re-connected. Mirror the netif_device_detach call
with a netif_device_attach call in gether_connect to fix re-connecting
gadgets.

Link: https://gitlab.com/postmarketOS/pmaports/-/tree/6002e51b7090aeeb42947e0ca7ec22278d7227d0/main/postmarketos-base-ui/rootfs-usr-lib-NetworkManager-dispatcher.d-50-tethering.sh
Cc: stable <stable@kernel.org>
Fixes: f49449fbc21e ("usb: gadget: u_ether: Replace netif_stop_queue with netif_device_detach")
Signed-off-by: Richard Acayan <mailingradian@gmail.com>
Tested-by: Luca Weiss <luca@z3ntu.xyz>
Tested-by: Duje Mihanović <duje.mihanovic@skole.hr>
Link: https://lore.kernel.org/r/20231218164532.411125-2-mailingradian@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: u_ether: Replace netif_stop_queue with netif_device_detach

This patch replaces the usage of netif_stop_queue with netif_device_detach
in the u_ether driver. The netif_device_detach function not only stops all
tx queues by calling netif_tx_stop_all_queues but also marks the device as
removed by clearing the __LINK_STATE_PRESENT bit.

This change helps notify user space about the disconnection of the device
more effectively, compared to netif_stop_queue, which only stops a single
transmit queue.

Signed-off-by: Hardik Gajjar <hgajjar@de.adit-jv.com>
Link: https://lore.kernel.org/r/20231006155646.12938-1-hgajjar@de.adit-jv.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: use working speed to calcaulate network bitrate and qlen

Take ecm_bitrate() as example, it will be called after gadget device
link speed negotiation, consider code
if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER),
if a gadget device link speed is USB_SPEED_SUPER,
gadget_is_superspeed(g) must be true, or not it is a wrong
configuration of gadget max support speed.

Remove gadget_is_superspeed(g) checking should be safe, and remove other
similar operation in ncm, rndis, u_ether.

Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Link: https://lore.kernel.org/r/20230803091053.9714-2-quic_linyyuan@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: u_ether: Fix host MAC address case

The CDC-ECM specification [1] requires to send the host MAC address as
an uppercase hexadecimal string in chapter "5.4 Ethernet Networking
Functional Descriptor":
The Unicode character is chosen from the set of values 30h through
39h and 41h through 46h (0-9 and A-F).

However, snprintf(.., "%pm", ..) generates a lowercase MAC address
string. While most host drivers are tolerant to this, UsbNcm.sys on
Windows 10 is not. Instead it uses a different MAC address with all
bytes set to zero including and after the first byte containing a
lowercase letter. On Windows 11 Microsoft fixed it, but apparently they
did not backport the fix.

This change fixes the issue by upper-casing the MAC to comply with the
specification.

[1]: https://www.usb.org/document-library/class-definitions-communication-devices-12, file ECM120.pdf

Fixes: bcd4a1c40bee ("usb: gadget: u_ether: construct with default values and add setters/getters")
Cc: stable@vger.kernel.org
Signed-off-by: Konrad Gräfe <k.graefe@gateware.de>
Link: https://lore.kernel.org/r/20230505143640.443014-1-k.graefe@gateware.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: f_ecm: Add suspend/resume and remote wakeup support

When host sends suspend notification to the device, handle
the suspend callbacks in the function driver. Depending on
the remote wakeup capability the device can either trigger a
remote wakeup or wait for the host initiated resume to resume
data transfer.

Signed-off-by: Elson Roy Serrao <quic_eserrao@quicinc.com>
Reviewed-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/1679694482-16430-7-git-send-email-quic_eserrao@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: u_ether: Don't warn in gether_setup_name_default()

The function gether_setup_name_default() is called by various USB
ethernet gadget drivers. Calling this function will select a random
host and device MAC addresses. A properly working driver should be
silent and not warn the user about default MAC addresses selection.
Given that the MAC addresses are also printed when the function
gether_register_netdev() is called, remove these unnecessary warnings.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
Link: https://lore.kernel.org/r/20230209125319.18589-2-jonathanh@nvidia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: u_ether: Convert prints to device prints

The USB ethernet gadget driver implements its own print macros which
call printk. Device drivers should use the device prints that print the
device name. Fortunately, the same macro names are defined in the header
file 'linux/usb/composite.h' and these use the device prints. Therefore,
remove the local definitions in the USB ethernet gadget driver and use
those in 'linux/usb/composite.h'. The only difference is that now the
device name is printed instead of the ethernet interface name.

Tested using ethernet gadget on Jetson AGX Orin.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20230209125319.18589-1-jonathanh@nvidia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Revert "usb: gadget: u_ether: Do not make UDC parent of the net device"

This reverts commit 321b59870f850a10dbb211ecd2bd87b41497ea6f.

This commit broke USB networking on Ingenic SoCs and maybe elsewhere.
The actual reason is unknown; and while a proper fix would be better,
we're sitting at -rc7 now, so a revert is justified - and we can work on
re-introducing this change for 6.3.

Fixes: 321b59870f85 ("usb: gadget: u_ether: Do not make UDC parent of the net device")
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Link: https://lore.kernel.org/r/20230209105626.10597-1-paul@crapouillou.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: u_ether: Do not make UDC parent of the net device

The UDC is not a suitable parent of the net device as the UDC can
change or vanish during the lifecycle of the ethernet gadget. This
can be illustrated with the following:

mkdir -p /sys/kernel/config/usb_gadget/mygadget
cd /sys/kernel/config/usb_gadget/mygadget
mkdir -p configs/c.1/strings/0x409
echo "C1:Composite Device" > configs/c.1/strings/0x409/configuration
mkdir -p functions/ecm.usb0
ln -s functions/ecm.usb0 configs/c.1/
echo "dummy_udc.0" > UDC
rmmod dummy_hcd

The 'rmmod' removes the UDC from the just created gadget, leaving
the still existing net device with a no longer existing parent.

Accessing the ethernet device with commands like:

ip --details link show usb0

will result in a KASAN splat:

==================================================================
BUG: KASAN: use-after-free in if_nlmsg_size+0x3e8/0x528
Read of size 4 at addr c5c84754 by task ip/357

CPU: 3 PID: 357 Comm: ip Not tainted 6.1.0-rc3-00013-gd14953726b24-dirty #324
Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
unwind_backtrace from show_stack+0x10/0x14
show_stack from dump_stack_lvl+0x58/0x70
dump_stack_lvl from print_report+0x134/0x4d4
print_report from kasan_report+0x78/0x10c
kasan_report from if_nlmsg_size+0x3e8/0x528
if_nlmsg_size from rtnl_getlink+0x2b4/0x4d0
rtnl_getlink from rtnetlink_rcv_msg+0x1f4/0x674
rtnetlink_rcv_msg from netlink_rcv_skb+0xb4/0x1f8
netlink_rcv_skb from netlink_unicast+0x294/0x478
netlink_unicast from netlink_sendmsg+0x328/0x640
netlink_sendmsg from ____sys_sendmsg+0x2a4/0x3b4
____sys_sendmsg from ___sys_sendmsg+0xc8/0x12c
___sys_sendmsg from sys_sendmsg+0xa0/0x120
sys_sendmsg from ret_fast_syscall+0x0/0x1c

Solve this by not setting the parent of the ethernet device.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Link: https://lore.kernel.org/r/20221104131031.850850-2-s.hauer@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: move from strlcpy with unused retval to strscpy

Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.

Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Reviewed-by: Richard Leitner <richard.leitner@skidata.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20220818210116.7517-1-wsa+renesas@sang-engineering.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: u_ether: Remove duplicated include in u_ether.c

Fix following includecheck warning:
./drivers/usb/gadget/function/u_ether.c: linux/etherdevice.h is included
more than once.

Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220623010808.9816-1-yang.lee@linux.alibaba.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: u_ether: fix regression in setting fixed MAC address

In systemd systems setting a fixed MAC address through
the "dev_addr" module argument fails systematically.
When checking the MAC address after the interface is created
it always has the same but different MAC address to the one
supplied as argument.

This is partially caused by systemd which by default will
set an internally generated permanent MAC address for interfaces
that are marked as having a randomly generated address.

Commit 890d5b40908bfd1a ("usb: gadget: u_ether: fix race in
setting MAC address in setup phase") didn't take into account
the fact that the interface must be marked as having a set
MAC address when it's set as module argument.

Fixed by marking the interface with NET_ADDR_SET when
the "dev_addr" module argument is supplied.

Fixes: 890d5b40908bfd1a ("usb: gadget: u_ether: fix race in setting MAC address in setup phase")
Cc: stable@vger.kernel.org
Signed-off-by: Marian Postevca <posteuca@mutex.one>
Link: https://lore.kernel.org/r/20220603153459.32722-1-posteuca@mutex.one
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: u_ether: fix race in setting MAC address in setup phase

When listening for notifications through netlink of a new interface being
registered, sporadically, it is possible for the MAC to be read as zero.
The zero MAC address lasts a short period of time and then switches to a
valid random MAC address.

This causes problems for netd in Android, which assumes that the interface
is malfunctioning and will not use it.

In the good case we get this log:
InterfaceController::getCfg() ifName usb0
hwAddr 92:a8:f0:73:79:5b ipv4Addr 0.0.0.0 flags 0x1002

In the error case we get these logs:
InterfaceController::getCfg() ifName usb0
hwAddr 00:00:00:00:00:00 ipv4Addr 0.0.0.0 flags 0x1002

netd : interfaceGetCfg("usb0")
netd : interfaceSetCfg() -> ServiceSpecificException
(99, "[Cannot assign requested address] : ioctl() failed")

The reason for the issue is the order in which the interface is setup,
it is first registered through register_netdev() and after the MAC
address is set.

Fixed by first setting the MAC address of the net_device and after that
calling register_netdev().

Fixes: bcd4a1c40bee885e ("usb: gadget: u_ether: construct with default values and add setters/getters")
Cc: stable@vger.kernel.org
Signed-off-by: Marian Postevca <posteuca@mutex.one>
Link: https://lore.kernel.org/r/20211204214912.17627-1-posteuca@mutex.one
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: u_ether: use eth_hw_addr_set()

Commit 406f42fa0d3c ("net-next: When a bond have a massive amount
of VLANs...") introduced a rbtree for faster Ethernet address look
up. To maintain netdev->dev_addr in this tree we need to make all
the writes to it got through appropriate helpers.

Reviewed-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20211019172124.1413620-1-kuba@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: u_ether: fix a potential null pointer dereference

f_ncm tx timeout can call us with null skb to flush
a pending frame. In this case skb is NULL to begin
with but ceases to be null after dev->wrap() completes.

In such a case in->maxpacket will be read, even though
we've failed to check that 'in' is not NULL.

Though I've never observed this fail in practice,
however the 'flush operation' simply does not make sense with
a null usb IN endpoint - there's nowhere to flush to...
(note that we're the gadget/device, and IN is from the point
of view of the host, so here IN actually means outbound...)

Cc: Brooke Basile <brookebasile@gmail.com>
Cc: "Bryan O'Donoghue" <bryan.odonoghue@linaro.org>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Link: https://lore.kernel.org/r/20210701114834.884597-6-zenczykowski@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: u_ether: support configuring interface names.

This patch allows the administrator to configure the interface
name of a function using u_ether (e.g., eem, ncm, rndis).

Currently, all such interfaces, regardless of function type, are
always called usb0, usb1, etc. This makes it very cumbersome to
use more than one such type at a time, because userspace cannnot
easily tell the interfaces apart and apply the right
configuration to each one. Interface renaming in userspace based
on driver doesn't help, because the interfaces all have the same
driver. Without this patch, doing this require hacks/workarounds
such as setting fixed MAC addresses on the functions, and then
renaming by MAC address, or scraping configfs after each
interface is created to find out what it is.

Setting the interface name is done by writing to the same
"ifname" configfs attribute that reports the interface name after
the function is bound. The write must contain an interface
pattern such as "usb%d" (which will cause the net core to pick
the next available interface name starting with "usb").
This patch does not allow writing an exact interface name (as
opposed to a pattern) because if the interface already exists at
bind time, the bind will fail and the whole gadget will fail to
activate. This could be allowed in a future patch.

For compatibility with current userspace, when reading an ifname
that has not currently been set, the result is still "(unnamed
net_device)". Once a write to ifname happens, then reading ifname
will return whatever was last written.

Tested by configuring an rndis function and an ncm function on
the same gadget, and writing "rndis%d" to ifname on the rndis
function and "ncm%d" to ifname on the ncm function. When the
gadget was bound, the rndis interface was rndis0 and the ncm
interface was ncm0.

Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Link: https://lore.kernel.org/r/20210113234222.3272933-1-lorenzo@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: u_ether: Fix MTU size mismatch with RX packet size

Fix the MTU size issue with RX packet size as the host sends the packet
with extra bytes containing ethernet header. This causes failure when
user sets the MTU size to the maximum i.e. 15412. In this case the
ethernet packet received will be of length 15412 plus the ethernet header
length. This patch fixes the issue where there is a check that RX packet
length must not be more than max packet length.

Fixes: bba787a860fa ("usb: gadget: ether: Allow jumbo frames")
Signed-off-by: Manish Narani <manish.narani@xilinx.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/1605597215-122027-1-git-send-email-manish.narani@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: u_ether: enable qmult on SuperSpeed Plus as well

The u_ether driver has a qmult setting that multiplies the
transmit queue length (which by default is 2).

The intent is that it should be enabled at high/super speed, but
because the code does not explicitly check for USB_SUPER_PLUS,
it is disabled at that speed.

Fix this by ensuring that the queue multiplier is enabled for any
wired link at high speed or above. Using >= for USB_SPEED_*
constants seems correct because it is what the gadget_is_xxxspeed
functions do.

The queue multiplier substantially helps performance at higher
speeds. On a direct SuperSpeed Plus link to a Linux laptop,
iperf3 single TCP stream:

Before (qmult=1): 1.3 Gbps
After (qmult=5): 3.2 Gbps

Fixes: 04617db7aa68 ("usb: gadget: add SS descriptors to Ethernet gadget")
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

usb: gadget: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20200707171500.GA13620@embeddedor
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: function: u_ether: Downgrade kerneldoc headers which to not make the mark

Kerneldoc expects all function arguments to be documented. If any
are missed it will complain. Downgrade one header with 3 missing
argument descriptions and one which makes no attempt.

Fixes the following W=1 kernel build warning(s):

drivers/usb/gadget/function/u_ether.c:750: warning: Function parameter or member 'dev_addr' not described in 'gether_setup_name'
drivers/usb/gadget/function/u_ether.c:750: warning: Function parameter or member 'host_addr' not described in 'gether_setup_name'
drivers/usb/gadget/function/u_ether.c:750: warning: Function parameter or member 'qmult' not described in 'gether_setup_name'
drivers/usb/gadget/function/u_ether.c:1022: warning: Function parameter or member 'dev' not described in 'gether_cleanup'

Cc: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20200706133341.476881-6-lee.jones@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: Replace snprintf with scnprintf in gether_get_ifname

snprintf returns the actual length of the buffer created; however,
this is not the case if snprintf truncates its parameter.
See https://lwn.net/Articles/69419/ for a detailed explanation.
The current code correctly handles this case at the expense
of extra code in the return statement.

scnprintf does returns the actual length of the buffer created
making the ?: operator unnecessary in the return
statement.

This change does not alter the functionality of the code.

Signed-off-by: Daniel M German <dmg@turingmachine.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: ether: Fix race between gether_disconnect and rx_submit

On spin lock release in rx_submit, gether_disconnect get a chance to
run, it makes port_usb NULL, rx_submit access NULL port USB, hence null
pointer crash.

Fixed by releasing the lock in rx_submit after port_usb is used.

Fixes: 2b3d942c4878 ("usb ethernet gadget: split out network core")
Cc: <stable@vger.kernel.org>
Signed-off-by: Kiruthika Varadarajan <Kiruthika.Varadarajan@harman.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

net: dev: Add extack argument to dev_set_mac_address()

A follow-up patch will add a notifier type NETDEV_PRE_CHANGEADDR, which
allows vetoing of MAC address changes. One prominent path to that
notification is through dev_set_mac_address(). Therefore give this
function an extack argument, so that it can be packed together with the
notification. Thus a textual reason for rejection (or a warning) can be
communicated back to the user.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

usb: gadget: u_ether: fix unsafe list iteration

list_for_each_entry_safe() is not safe for deleting entries from the
list if the spin lock, which protects it, is released and reacquired during
the list iteration. Fix this issue by replacing this construction with
a simple check if list is empty and removing the first entry in each
iteration. This is almost equivalent to a revert of the commit mentioned in
the Fixes: tag.

This patch fixes following issue:
--->8---
Unable to handle kernel NULL pointer dereference at virtual address 00000104
pgd = (ptrval)
[00000104] *pgd=00000000
Internal error: Oops: 817 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 1 PID: 84 Comm: kworker/1:1 Not tainted 4.20.0-rc2-next-20181114-00009-g8266b35ec404 #1061
Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
Workqueue: events eth_work
PC is at rx_fill+0x60/0xac
LR is at _raw_spin_lock_irqsave+0x50/0x5c
pc : [<c065fee0>] lr : [<c0a056b8>] psr: 80000093
sp : ee7fbee8 ip : 00000100 fp : 00000000
r10: 006000c0 r9 : c10b0ab0 r8 : ee7eb5c0
r7 : ee7eb614 r6 : ee7eb5ec r5 : 000000dc r4 : ee12ac00
r3 : ee12ac24 r2 : 00000200 r1 : 60000013 r0 : ee7eb5ec
Flags: Nzcv IRQs off FIQs on Mode SVC_32 ISA ARM Segment none
Control: 10c5387d Table: 6d5dc04a DAC: 00000051
Process kworker/1:1 (pid: 84, stack limit = 0x(ptrval))
Stack: (0xee7fbee8 to 0xee7fc000)
...
[<c065fee0>] (rx_fill) from [<c0143b7c>] (process_one_work+0x200/0x738)
[<c0143b7c>] (process_one_work) from [<c0144118>] (worker_thread+0x2c/0x4c8)
[<c0144118>] (worker_thread) from [<c014a8a4>] (kthread+0x128/0x164)
[<c014a8a4>] (kthread) from [<c01010b4>] (ret_from_fork+0x14/0x20)
Exception stack(0xee7fbfb0 to 0xee7fbff8)
...
---[ end trace 64480bc835eba7d6 ]---

Fixes: fea14e68ff5e ("usb: gadget: u_ether: use better list accessors")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

USB: Gadget Ethernet: Re-enable Jumbo frames.

Fixes: <b3e3893e1253> ("net: use core MTU range checking")
which patched only one of two functions used to setup the
USB Gadget Ethernet driver, causing a serious performance
regression in the ability to increase mtu size above 1500.

Signed-off-by: John Greb <h3x4m3r0n@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

USB: gadget: function: Remove redundant license text

Now that the SPDX tag is in all USB files, that identifies the license
in a specific and legally-defined manner. So the extra GPL text wording
can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text. And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Oliver Neukum <oneukum@suse.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Jerry Zhang <zhangjerry@google.com>
Cc: John Keeping <john@metanate.com>
Cc: Krzysztof Opasiak <k.opasiak@samsung.com>
Cc: Abdulhadi Mohamed <abdulahhadi2@gmail.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Janusz Dziedzic <januszx.dziedzic@linux.intel.com>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Vincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: add SPDX identifiers to all remaining files in drivers/usb/

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/usb/ and include/linux/usb* files with the correct
SPDX license identifier based on the license text in the file itself.
The SPDX identifier is a legally binding shorthand, which can be used
instead of the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: f_ncm/u_ether: Move 'SKB reserve' quirk setup to u_ether

That quirk is required to make USB Ethernet gadget working on HW that
can't cope with unaligned DMA. For some reason only f_ncm sets up that
quirk, let's setup it directly in u_ether so other network models would
have that quirk applied as well. All network models have been tested with
ChipIdea UDC driver on NVIDIA Tegra20 SoC that require DMA to be aligned.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: u_ether: conditionally align transfer size

Unless HW sets quirk_ep_out_aligned_size, gadget driver shouldn't make
any efforts towards aligning transfers. If the UDC needs, it *must*
set the quirk flag.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: u_ether: use better list accessors

We have helpers for some of these, let's rely on them instead of open
coding what they do in u_ether.c

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: ether: Add \n to each attribute of ethernet functions

Generally in SysFS and ConfigFS files are new line terminated.
Also most of USB functions adds a trailing newline to each attribute.
Let's follow this convention also in ethernet functions.

Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: NCM: differentiate consumed packets from dropped packets

dev_kfree_skb_any() is used to free packets that are dropped by the
network stack. Therefore the function should not be used for packets
that have been successfully processed by the network stack. Instead
dev_consume_skb_any() has to be used for such consumed packets.

This separation helps to identify dropped packets.

Signed-off-by: Torsten Polle <tpolle@de.adit-jv.com>
Signed-off-by: Harish Jenny K N <harish_kandiga@mentor.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: u_ether: link socket buffers to the device for received packets

Socket buffers should be linked to the (network) device that allocated
the buffers. __netdev_alloc_skb performs this task.

Signed-off-by: Torsten Polle <tpolle@de.adit-jv.com>
Signed-off-by: Jim Baxter <jim_baxter@mentor.com>
Signed-off-by: Harish Jenny K N <harish_kandiga@mentor.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: u_ether: remove interrupt throttling

According to Dave Miller "the networking stack has a
hard requirement that all SKBs which are transmitted
must have their completion signalled in a fininte
amount of time. This is because, until the SKB is
freed by the driver, it holds onto socket,
netfilter, and other subsystem resources."

In summary, this means that using TX IRQ throttling
for the networking gadgets is, at least, complex and
we should avoid it for the time being.

Cc: <stable@vger.kernel.org>
Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Suggested-by: David Miller <davem@davemloft.net>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

net: use core MTU range checking in misc drivers

firewire-net:
- set min/max_mtu
- remove fwnet_change_mtu

nes:
- set max_mtu
- clean up nes_netdev_change_mtu

xpnet:
- set min/max_mtu
- remove xpnet_dev_change_mtu

hippi:
- set min/max_mtu
- remove hippi_change_mtu

batman-adv:
- set max_mtu
- remove batadv_interface_change_mtu
- initialization is a little async, not 100% certain that max_mtu is set
in the optimal place, don't have hardware to test with

rionet:
- set min/max_mtu
- remove rionet_change_mtu

slip:
- set min/max_mtu
- streamline sl_change_mtu

um/net_kern:
- remove pointless ndo_change_mtu

hsi/clients/ssi_protocol:
- use core MTU range checking
- remove now redundant ssip_pn_set_mtu

ipoib:
- set a default max MTU value
- Note: ipoib's actual max MTU can vary, depending on if the device is in
connected mode or not, so we'll just set the max_mtu value to the max
possible, and let the ndo_change_mtu function continue to validate any new
MTU change requests with checks for CM or not. Note that ipoib has no
min_mtu set, and thus, the network core's mtu > 0 check is the only lower
bounds here.

mptlan:
- use net core MTU range checking
- remove now redundant mpt_lan_change_mtu

fddi:
- min_mtu = 21, max_mtu = 4470
- remove now redundant fddi_change_mtu (including export)

fjes:
- min_mtu = 8192, max_mtu = 65536
- The max_mtu value is actually one over IP_MAX_MTU here, but the idea is to
get past the core net MTU range checks so fjes_change_mtu can validate a
new MTU against what it supports (see fjes_support_mtu in fjes_hw.c)

hsr:
- min_mtu = 0 (calls ether_setup, max_mtu is 1500)

f_phonet:
- min_mtu = 6, max_mtu = 65541

u_ether:
- min_mtu = 14, max_mtu = 15412

phonet/pep-gprs:
- min_mtu = 576, max_mtu = 65530
- remove redundant gprs_set_mtu

CC: netdev@vger.kernel.org
CC: linux-rdma@vger.kernel.org
CC: Stefan Richter <stefanr@s5r6.in-berlin.de>
CC: Faisal Latif <faisal.latif@intel.com>
CC: linux-rdma@vger.kernel.org
CC: Cliff Whickman <cpw@sgi.com>
CC: Robin Holt <robinmholt@gmail.com>
CC: Jes Sorensen <jes@trained-monkey.org>
CC: Marek Lindner <mareklindner@neomailbox.ch>
CC: Simon Wunderlich <sw@simonwunderlich.de>
CC: Antonio Quartulli <a@unstable.cc>
CC: Sathya Prakash <sathya.prakash@broadcom.com>
CC: Chaitra P B <chaitra.basappa@broadcom.com>
CC: Suganath Prabu Subramani <suganath-prabu.subramani@broadcom.com>
CC: MPT-FusionLinux.pdl@broadcom.com
CC: Sebastian Reichel <sre@kernel.org>
CC: Felipe Balbi <balbi@kernel.org>
CC: Arvid Brodin <arvid.brodin@alten.se>
CC: Remi Denis-Courmont <courmisch@gmail.com>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

usb: gadget: function: u_ether: don't starve tx request queue

If we don't guarantee that we will always get an
interrupt at least when we're queueing our very last
request, we could fall into situation where we queue
every request with 'no_interrupt' set. This will
cause the link to get stuck.

The behavior above has been triggered with g_ether
and dwc3.

Cc: <stable@vger.kernel.org>
Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

Revert "usb: gadget: NCM: Protect dev->port_usb using dev->lock"

This reverts commit c9ffc78745f89e300fe704348dd8e6800acf4d18 as it was
reported to be broken.

Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: Jim Baxter <jim_baxter@mentor.com>
Cc: Harish Jenny K N <harish_kandiga@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: NCM: Protect dev->port_usb using dev->lock

This commit incorporates findings from
https://lkml.org/lkml/2016/4/25/594

The function has been modified to make sure we hold
the dev lock when accessing the net device pointer.

Acked-by: Jim Baxter <jim_baxter@mentor.com>
Signed-off-by: Harish Jenny K N <harish_kandiga@mentor.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: u_ether: fix another dereference after null check

dev->port_usb is checked for null pointer previously, so dev->port_usb
might be null during no zlp check, fix it by adding null pointer check.

Acked-by: Jim Baxter <jim_baxter@mentor.com>
Signed-off-by: Harish Jenny K N <harish_kandiga@mentor.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: u_ether: add a flag to avoid skb_reserve() calling

This patch adds a flag "no_skb_reserve" in struct eth_dev.
So, if a peripheral driver sets the quirk_avoids_skb_reserve flag,
upper network gadget drivers (e.g. f_ncm.c) can avoid skb_reserve()
calling using the flag as well.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: u_ether: fix dereference after null check coverify warning

dev->port_usb is checked for null pointer at above code, so dev->port_usb
might be null, fix it by adding null pointer check.

Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

treewide: replace dev->trans_start update with helper

Replace all trans_start updates with netif_trans_update helper.
change was done via spatch:

struct net_device *d;
@@
- d->trans_start = jiffies
+ netif_trans_update(d)

Compile tested only.

Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: linux-xtensa@linux-xtensa.org
Cc: linux1394-devel@lists.sourceforge.net
Cc: linux-rdma@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: MPT-FusionLinux.pdl@broadcom.com
Cc: linux-scsi@vger.kernel.org
Cc: linux-can@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linux-omap@vger.kernel.org
Cc: linux-hams@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Cc: linux-wireless@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: devel@driverdev.osuosl.org
Cc: b.a.t.m.a.n@lists.open-mesh.org
Cc: linux-bluetooth@vger.kernel.org
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Mugunthan V N <mugunthanvnm@ti.com>
Acked-by: Antonio Quartulli <a@unstable.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>

usb: gadget: ether: Allow changing the MTU

The gadget ethernet driver supports changing the MTU, but only allows this
when the USB cable is removed. The comment indicates that this is because
the "peer won't know". Even if the network link is still down and only the
USB link is established, the driver won't allow the change.

Other network interfaces allow changing the MTU any time, and don't force
the link to be disabled. This makes perfect sense, because in order to be
able to negotiate the MTU, the link needs to be up.

Remove the restriction so that it is now actually possible to change the
MTU (e.g. using "ifconfig usb0 mtu 15000") without having to manually pull
the plug or change the driver's default setting.

This is especially important after commit bba787a860fa
("usb: gadget: ether: Allow jumbo frames")

Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: u_ether: eliminate abuse of ep->driver data

Since ep->driver_data is not used for endpoint claiming, neither for
enabled/disabled state storing, we can reduce number of places where
we read or modify it's value, as now it has no particular meaning for
function or framework logic.

In case of u_ether we only need to store in ep->driver_data pointer to
struct eth_dev, as it's used in rx_complete() and tx_complete() callbacks.
All other uses of ep->driver_data are now meaningless and can be safely
removed.

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: ether: Allow jumbo frames

USB network adapters support Jumbo frames. The only thing blocking
that feature is the code in the gadget driver that disposes of
packets larger than 1518 bytes, and the limit on the ioctl to set
the mtu.

This patch relaxes these limits, and allows up to 15k frames sizes.
The 15k value was chosen because 16k does not work on all platforms,
and usingclose to 16k will result in allocating 5 or 8 4k pages to
store the skb, wasting pages at no measurable performance gain.

On a topic-miami board (Zynq-7000), iperf3 performance reports:
MTU= 1500, PC-to-gadget: 139 Mbps, Gadget-to-PC: 116 Mbps
MTU=15000, PC-to-gadget: 239 Mbps, Gadget-to-PC: 361 Mbps

On boards with slower CPUs the performance improvement will be
relatively much larger, e.g. an OMAP-L138 increased from 40 to
220 Mbps using a similar patch on an 2.6.37 kernel.

Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: ethernet: re-use %pM specifier to print MAC

Instead of custom approach the patch converts code to use %pM specifier to
print MAC.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

Revert "usb: gadget: u_ether: synchronize with transmit when stopping queue"

This reverts commit a9232076374334ca2bc2a448dfde96d38a54349a.

It introduced a dead lock, and did not fix anything.

it made netif_tx_lock() be called in IRQ context, but in softirq context,
the same lock is locked without disabling IRQ. In fact, the commit a923207637
did not fix anything, since netif_stop_queue did not free the any resource

[ 10.154920] =================================
[ 10.156026] [ INFO: inconsistent lock state ]
[ 10.156026] 3.16.0-rc5+ #13 Not tainted
[ 10.156026] ---------------------------------
[ 10.156026] inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
[ 10.156026] swapper/1/0 [HC0[0]:SC1[5]:HE1:SE0] takes:
[ 10.156026] (_xmit_ETHER){?.-...}, at: [<80948b6a>] sch_direct_xmit+0x7a/0x250
[ 10.156026] {IN-HARDIRQ-W} state was registered at:
[ 10.156026] [<804811f0>] __lock_acquire+0x800/0x17a0
[ 10.156026] [<804828ba>] lock_acquire+0x6a/0xf0
[ 10.156026] [<809ed477>] _raw_spin_lock+0x27/0x40
[ 10.156026] [<8088d508>] gether_disconnect+0x68/0x280
[ 10.156026] [<8088e777>] eem_set_alt+0x37/0xc0
[ 10.156026] [<808847ce>] composite_setup+0x30e/0x1240
[ 10.156026] [<8088b8ae>] pch_udc_isr+0xa6e/0xf50
[ 10.156026] [<8048abe8>] handle_irq_event_percpu+0x38/0x1e0
[ 10.156026] [<8048adc1>] handle_irq_event+0x31/0x50
[ 10.156026] [<8048d94b>] handle_fasteoi_irq+0x6b/0x140
[ 10.156026] [<804040a5>] handle_irq+0x65/0x80
[ 10.156026] [<80403cfc>] do_IRQ+0x3c/0xc0
[ 10.156026] [<809ee6ae>] common_interrupt+0x2e/0x34
[ 10.156026] [<804668c5>] finish_task_switch+0x65/0xd0
[ 10.156026] [<809e89df>] __schedule+0x20f/0x7d0
[ 10.156026] [<809e94aa>] schedule_preempt_disabled+0x2a/0x70
[ 10.156026] [<8047bf03>] cpu_startup_entry+0x143/0x410
[ 10.156026] [<809e2e61>] rest_init+0xa1/0xb0
[ 10.156026] [<80ce2a3b>] start_kernel+0x336/0x33b
[ 10.156026] [<80ce22ab>] i386_start_kernel+0x79/0x7d
[ 10.156026] irq event stamp: 52070
[ 10.156026] hardirqs last enabled at (52070): [<809375de>] neigh_resolve_output+0xee/0x2a0
[ 10.156026] hardirqs last disabled at (52069): [<809375a8>] neigh_resolve_output+0xb8/0x2a0
[ 10.156026] softirqs last enabled at (52020): [<8044401f>] _local_bh_enable+0x1f/0x50
[ 10.156026] softirqs last disabled at (52021): [<80404036>] do_softirq_own_stack+0x26/0x30
[ 10.156026]
[ 10.156026] other info that might help us debug this:
[ 10.156026] Possible unsafe locking scenario:
[ 10.156026]
[ 10.156026] CPU0
[ 10.156026] ----
[ 10.156026] lock(_xmit_ETHER);
[ 10.156026] <Interrupt>
[ 10.156026] lock(_xmit_ETHER);
[ 10.156026]
[ 10.156026] *** DEADLOCK ***
[ 10.156026]
[ 10.156026] 4 locks held by swapper/1/0:
[ 10.156026] #0: (((&idev->mc_ifc_timer))){+.-...}, at: [<8044b100>] call_timer_fn+0x0/0x190
[ 10.156026] #1: (rcu_read_lock){......}, at: [<a0577c40>] mld_sendpack+0x0/0x590 [ipv6]
[ 10.156026] #2: (rcu_read_lock_bh){......}, at: [<a055680c>] ip6_finish_output2+0x4c/0x7f0 [ipv6]
[ 10.156026] #3: (rcu_read_lock_bh){......}, at: [<8092e510>] __dev_queue_xmit+0x0/0x5f0
[ 10.156026]
[ 10.156026] stack backtrace:
[ 10.156026] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.16.0-rc5+ #13
[ 10.156026] 811dbb10 00000000 9e919d10 809e6785 9e8b8000 9e919d3c 809e561e 80b95511
[ 10.156026] 80b9545a 80b9543d 80b95450 80b95441 80b957e4 9e8b84e0 00000002 8047f7b0
[ 10.156026] 9e919d5c 8048043b 00000002 00000000 9e8b8000 00000001 00000004 9e8b8000
[ 10.156026] Call Trace:
[ 10.156026] [<809e6785>] dump_stack+0x48/0x69
[ 10.156026] [<809e561e>] print_usage_bug+0x18f/0x19c
[ 10.156026] [<8047f7b0>] ? print_shortest_lock_dependencies+0x170/0x170
[ 10.156026] [<8048043b>] mark_lock+0x53b/0x5f0
[ 10.156026] [<804810cf>] __lock_acquire+0x6df/0x17a0
[ 10.156026] [<804828ba>] lock_acquire+0x6a/0xf0
[ 10.156026] [<80948b6a>] ? sch_direct_xmit+0x7a/0x250
[ 10.156026] [<809ed477>] _raw_spin_lock+0x27/0x40
[ 10.156026] [<80948b6a>] ? sch_direct_xmit+0x7a/0x250
[ 10.156026] [<80948b6a>] sch_direct_xmit+0x7a/0x250
[ 10.156026] [<8092e6bf>] __dev_queue_xmit+0x1af/0x5f0
[ 10.156026] [<80947fc0>] ? ether_setup+0x80/0x80
[ 10.156026] [<8092eb0f>] dev_queue_xmit+0xf/0x20
[ 10.156026] [<8093764c>] neigh_resolve_output+0x15c/0x2a0
[ 10.156026] [<a0556927>] ip6_finish_output2+0x167/0x7f0 [ipv6]
[ 10.156026] [<a0559b05>] ip6_finish_output+0x85/0x1c0 [ipv6]
[ 10.156026] [<a0559cb7>] ip6_output+0x77/0x240 [ipv6]
[ 10.156026] [<a0578163>] mld_sendpack+0x523/0x590 [ipv6]
[ 10.156026] [<80480501>] ? mark_held_locks+0x11/0x90
[ 10.156026] [<a057947d>] mld_ifc_timer_expire+0x15d/0x280 [ipv6]
[ 10.156026] [<8044b168>] call_timer_fn+0x68/0x190
[ 10.156026] [<a0579320>] ? igmp6_group_added+0x150/0x150 [ipv6]
[ 10.156026] [<8044b3fa>] run_timer_softirq+0x16a/0x240
[ 10.156026] [<a0579320>] ? igmp6_group_added+0x150/0x150 [ipv6]
[ 10.156026] [<80444984>] __do_softirq+0xd4/0x2f0
[ 10.156026] [<804448b0>] ? tasklet_action+0x100/0x100
[ 10.156026] [<80404036>] do_softirq_own_stack+0x26/0x30
[ 10.156026] <IRQ> [<80444d05>] irq_exit+0x65/0x70
[ 10.156026] [<8042d758>] smp_apic_timer_interrupt+0x38/0x50
[ 10.156026] [<809ee91f>] apic_timer_interrupt+0x2f/0x34
[ 10.156026] [<8048007b>] ? mark_lock+0x17b/0x5f0
[ 10.156026] [<8040a912>] ? default_idle+0x22/0xf0
[ 10.156026] [<8040b13e>] arch_cpu_idle+0xe/0x10
[ 10.156026] [<8047bfc6>] cpu_startup_entry+0x206/0x410
[ 10.156026] [<8042bfbd>] start_secondary+0x19d/0x1e0

Acked-by: Tony Lindgren <tony@atomide.com>
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jeff Westfahl <jeff.westfahl@ni.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <linux-usb@vger.kernel.org>
Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: Gadget directory cleanup - group usb functions

The drivers/usb/gadget directory contains many files.
Files which are related can be distributed into separate directories.
This patch moves the USB functions implementations into a separate directory.

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