firewire: fix warnings to generate UAPI documentation

Any target to generate UAPI documentation reports warnings to missing
annotation for padding member in structures added recently.

This commit suppresses the warnings.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/lkml/20230531135306.43613a59@canb.auug.org.au/
Fixes: 7c22d4a92bb2 ("firewire: cdev: add new event to notify request subaction with time stamp")
Fixes: fc2b52cf2e0e ("firewire: cdev: add new event to notify response subaction with time stamp")
Link: https://lore.kernel.org/r/20230601144937.121179-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

firewire: cdev: add new event to notify phy packet with time stamp

This commit adds new event to notify event of phy packet with time stamp
field.

Unlike the fw_cdev_event_request3 and fw_cdev_event_response2, the size
of new structure, fw_cdev_event_phy_packet2, is multiples of 8, thus
padding is not required to keep the same size between System V ABI for
different architectures.

It is noticeable that for the case of ping request 1394 OHCI controller
does not record the isochronous cycle at which the packet was sent for
the request subaction. Instead, it records round-trip count measured by
hardware at 42.195 MHz resolution.

Cc: kunit-dev@googlegroups.com
Link: https://lore.kernel.org/r/20230529113406.986289-12-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

firewire: cdev: add new event to notify response subaction with time stamp

This commit adds new event to notify event of response subaction with
time stamp field.

Current compiler implementation of System V ABI selects one of structure
members which has the maximum alignment size in the structure to decide
the size of structure. In the case of fw_cdev_event_request3 structure,
it is closure member which has 8 byte storage. The size of alignment for
the type of 8 byte storage differs depending on architectures; 4 byte for
i386 architecture and 8 byte for the others including x32 architecture.
It is inconvenient to device driver developer to use structure layout
which varies between architectures since the developer takes care of ioctl
compat layer. This commit adds 32 bit member for padding to keep the
size of structure as multiples of 8.

Cc: kunit-dev@googlegroups.com
Link: https://lore.kernel.org/r/20230529113406.986289-9-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

firewire: cdev: add new event to notify request subaction with time stamp

This commit adds new event to notify event of request subaction with
time stamp field.

Current compiler implementation of System V ABI selects one of structure
members which has the maximum alignment size in the structure to decide
the size of structure. In the case of fw_cdev_event_request3 structure,
it is closure member which has 8 byte storage. The size of alignment for
the type of 8 byte storage differs depending on architectures; 4 byte for
i386 architecture and 8 byte for the others including x32 architecture.
It is inconvenient to device driver developer to use structure layout
which varies between architectures since the developer takes care of ioctl
compat layer. This commit adds 32 bit member for padding to keep the
size of structure as multiples of 8.

Cc: kunit-dev@googlegroups.com
Link: https://lore.kernel.org/r/20230529113406.986289-4-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

firewire: cdev: add new version of ABI to notify time stamp at request/response subaction of transaction

This commit adds new version of ABI for future new events with time stamp
for request/response subaction of asynchronous transaction to user
space.

Link: https://lore.kernel.org/r/20230529113406.986289-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

treewide: uapi: Replace zero-length arrays with flexible-array members

There is a regular need in the kernel to provide a way to declare
having a dynamically sized set of trailing elements in a structure.
Kernel code should always use “flexible array members”[1] for these
cases. The older style of one-element or zero-length arrays should
no longer be used[2].

This code was transformed with the help of Coccinelle:
(linux-5.19-rc2$ spatch --jobs $(getconf _NPROCESSORS_ONLN) --sp-file script.cocci --include-headers --dir . > output.patch)

@@
identifier S, member, array;
type T1, T2;
@@

struct S {
...
T1 member;
T2 array[
- 0
];
};

-fstrict-flex-arrays=3 is coming and we need to land these changes
to prevent issues like these in the short future:

../fs/minix/dir.c:337:3: warning: 'strcpy' will always overflow; destination buffer has size 0,
but the source string has length 2 (including NUL byte) [-Wfortify-source]
strcpy(de3->name, ".");
^

Since these are all [0] to [] changes, the risk to UAPI is nearly zero. If
this breaks anything, we can use a union with a new member name.

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays

Link: https://github.com/KSPP/linux/issues/78
Build-tested-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/62b675ec.wKX6AOZ6cbE71vtF%25lkp@intel.com/
Acked-by: Dan Williams <dan.j.williams@intel.com> # For ndctl.h
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

include/linux: remove repeated words

Drop the doubled word "for" in a comment. {firewire-cdev.h}
Drop the doubled word "in" in a comment. {input.h}
Drop the doubled word "a" in a comment. {mdev.h}
Drop the doubled word "the" in a comment. {ptrace.h}

Link: https://lkml.kernel.org/r/20210126232444.22861-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Kirti Wankhede <kwankhede@nvidia.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

firewire: firewire-cdev.hL get rid of a docs warning

This warning:

./include/uapi/linux/firewire-cdev.h:312: WARNING: Inline literal start-string without end-string.

is because %FOO doesn't work if there's a parenthesis at the
string (as a parenthesis may indicate a function). So, mark
the literal block using the alternate ``FOO`` syntax.

Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/9b2501a41eba27ccdd4603cac2353c0efba7a90a.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

FireWire: clean up firewire-cdev.h kernel-doc

Clean up kernel-doc warnings in <linux/firewire-cdev.h> so that
it can be added to a Firewire/IEEE 1394 driver-api chapter
without adding lots of noisy warnings to the documentation build.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Cc: linux-doc@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

firewire: fix libdc1394/FlyCap2 iso event regression

Commit 18d627113b83 (firewire: prevent dropping of completed iso packet
header data) was intended to be an obvious bug fix, but libdc1394 and
FlyCap2 depend on the old behaviour by ignoring all returned information
and thus not noticing that not all packets have been received yet. The
result was that the video frame buffers would be saved before they
contained the correct data.

Reintroduce the old behaviour for old clients.

Tested-by: Stepan Salenikovich <stepan.salenikovich@gmail.com>
Tested-by: Josep Bosch <jep250@gmail.com>
Cc: <stable@vger.kernel.org> # 3.4+
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

UAPI: (Scripted) Disintegrate include/linux

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>