usb: gadget: rndis: add spinlock for rndis response list

There's no lock for rndis response list. It could cause list corruption
if there're two different list_add at the same time like below.
It's better to add in rndis_add_response / rndis_free_response
/ rndis_get_next_response to prevent any race condition on response list.

[ 361.894299] [1: irq/191-dwc3:16979] list_add corruption.
next->prev should be prev (ffffff80651764d0),
but was ffffff883dc36f80. (next=ffffff80651764d0).

[ 361.904380] [1: irq/191-dwc3:16979] Call trace:
[ 361.904391] [1: irq/191-dwc3:16979] __list_add_valid+0x74/0x90
[ 361.904401] [1: irq/191-dwc3:16979] rndis_msg_parser+0x168/0x8c0
[ 361.904409] [1: irq/191-dwc3:16979] rndis_command_complete+0x24/0x84
[ 361.904417] [1: irq/191-dwc3:16979] usb_gadget_giveback_request+0x20/0xe4
[ 361.904426] [1: irq/191-dwc3:16979] dwc3_gadget_giveback+0x44/0x60
[ 361.904434] [1: irq/191-dwc3:16979] dwc3_ep0_complete_data+0x1e8/0x3a0
[ 361.904442] [1: irq/191-dwc3:16979] dwc3_ep0_interrupt+0x29c/0x3dc
[ 361.904450] [1: irq/191-dwc3:16979] dwc3_process_event_entry+0x78/0x6cc
[ 361.904457] [1: irq/191-dwc3:16979] dwc3_process_event_buf+0xa0/0x1ec
[ 361.904465] [1: irq/191-dwc3:16979] dwc3_thread_interrupt+0x34/0x5c

Fixes: f6281af9d62e ("usb: gadget: rndis: use list_for_each_entry_safe")
Cc: stable <stable@kernel.org>
Signed-off-by: Daehwan Jung <dh10.jung@samsung.com>
Link: https://lore.kernel.org/r/1645507768-77687-1-git-send-email-dh10.jung@samsung.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: gadget: Use the correct style for SPDX License Identifier

This patch corrects the SPDX License Identifier style in
header files related to USB peripheral controller drivers.
For C header files Documentation/process/license-rules.rst
mandates C-like comments (opposed to C source files where
C++ style should be used).

Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46.

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

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: Fix checkpatch error for braces

Fix error message by checkpath.pl
open brace '{' following struct/enum go on the same line

Patch applied by running fix inplace capability of checkpatch:
checkpatch.pl -f *.[ch] --types OPEN_BRACE --fix-inplace

Signed-off-by: Anson Jacob <ansonjacob.aj@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: rndis: use signed type for a signed value

rndis_get_nr() returns either a non-negative value on success
or a negative value on failure. In case of failure an error code
is returned to the caller of rndis_register().
If the "i" is unsigned, the information about error from rndis_get_nr()
is lost. If there is no error but rndis_get_nr() returns a value greater
than 256 the least significant bits of i are zero effectively limiting the
number of configs to 256.

This patch fixes that.

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

usb: gadget: rndis: style correction

Don't use a space between function name and parameter list opening bracket.
All other functions in this file comply wich checkpatch rules.

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

usb: gadget: rndis: use rndis_params instead of configNr

RNDIS function has a limitation on the number of allowed instances.
So far it has been RNDIS_MAX_CONFIGS, which happens to be one.
In order to eliminate this kind of arbitrary limitation we should not
preallocate a predefined (RNDIS_MAX_CONFIGS) array of struct rndis_params
instances but instead allow allocating them on demand.

This patch prepares the elimination of the said limit by converting all the
functions which accept rndis config number to accept a pointer to the
actual struct rndis_params. Consequently, rndis_register() returns
a pointer to a corresponding struct rndis_params instance. The pointer
is then always used by f_rndis.c instead of config number when it talks
to rndis.c API.

A nice side-effect of the changes is that many lines of code in rndis.c
become shorter and fit in 80 columns.

If a function prototype changes in rndis.h a style cleanup is made
at the same time, otherwise checkpatch complains that the patch
has style problems.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.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>