This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>

Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
  firewire: document the sysfs ABIs
  firewire: cdev: ABI documentation enhancements
  firewire: cdev: prevent race between first get_info ioctl and bus reset event queuing
  firewire: cdev: return -ENOTTY for unimplemented ioctls, not -EINVAL
  firewire: ohci: skip soft reset retries after card ejection
  firewire: ohci: fix PHY reg access after card ejection
  firewire: ohci: add a comment on PHY reg access serialization
  firewire: ohci: reduce potential context_stop latency
  firewire: ohci: remove superfluous posted write flushes
  firewire: net: replacing deprecated __attribute__((packed)) with __packed

Between open(2) of a /dev/fw* and the first FW_CDEV_IOC_GET_INFO
ioctl(2) on it, the kernel already queues FW_CDEV_EVENT_BUS_RESET events
to be read(2) by the client.  The get_info ioctl is practically always
issued right away after open, hence this condition only occurs if the
client opens during a bus reset, especially during a rapid series of bus
resets.

The problem with this condition is twofold:

  - These bus reset events carry the (as yet undocumented) @closure
    value of 0.  But it is not the kernel's place to choose closures;
    they are privat to the client.  E.g., this 0 value forced from the
    kernel makes it unsafe for clients to dereference it as a pointer to
    a closure object without NULL pointer check.

  - It is impossible for clients to determine the relative order of bus
    reset events from get_info ioctl(2) versus those from read(2),
    except in one way:  By comparison of closure values.  Again, such a
    procedure imposes complexity on clients and reduces freedom in use
    of the bus reset closure.

So, change the ABI to suppress queuing of bus reset events before the
first FW_CDEV_IOC_GET_INFO ioctl was issued by the client.

Note, this ABI change cannot be version-controlled.  The kernel cannot
distinguish old from new clients before the first FW_CDEV_IOC_GET_INFO
ioctl.

We will try to back-merge this change into currently maintained stable/
longterm series, and we only document the new behaviour.  The old
behavior is now considered a kernel bug, which it basically is.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: <stable@kernel.org>

On Jun 27 Linus Torvalds wrote:
> The correct error code for "I don't understand this ioctl" is ENOTTY.
> The naming may be odd, but you should think of that error value as a
> "unrecognized ioctl number, you're feeding me random numbers that I
> don't understand and I assume for historical reasons that you tried to
> do some tty operation on me".
[...]
> The EINVAL thing goes way back, and is a disaster. It predates Linux
> itself, as far as I can tell. You'll find lots of man-pages that have
> this line in it:
>
>   EINVAL Request or argp is not valid.
>
> and it shows up in POSIX etc. And sadly, it generally shows up
> _before_ the line that says
>
>   ENOTTY The specified request does not apply to the kind of object
> that the descriptor d references.
>
> so a lot of people get to the EINVAL, and never even notice the ENOTTY.
[...]
> At least glibc (and hopefully other C libraries) use a _string_ that
> makes much more sense: strerror(ENOTTY) is "Inappropriate ioctl for
> device"

So let's correct this in the <linux/firewire-cdev.h> ABI while it is
still young, relative to distributor adoption.

Side note:  We return -ENOTTY not only on _IOC_TYPE or _IOC_NR mismatch,
but also on _IOC_SIZE mismatch.  An ioctl with an unsupported size of
argument structure can be seen as an unsupported version of that ioctl.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: <stable@kernel.org>

Conflicts:
	net/bluetooth/l2cap_core.c

Signed-off-by: David S. Miller <davem@davemloft.net>

When firewire-ohci is bound to a Pinnacle MovieBoard, eventually a
"Register access failure" is logged and an interrupt storm or a kernel
panic happens.  https://bugzilla.kernel.org/show_bug.cgi?id=36622

Until this is sorted out (if that is going to succeed at all), let's
just prevent firewire-ohci from touching these devices.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: <stable@kernel.org>

The software reset in firewire-ohci's pci_remove does not have a great
prospect of success if the card was already physically removed at this
point.  So let's skip the 500 ms that were spent in retries here.

Also, replace a defined constant by its open-coded value.  This is not a
constant from a specification but an arbitrarily chosen retry limit.  It
was only used in this single place.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

Detect and handle ejection of FireWire CardBus cards in PHY register
accesses:

  - The last attempt of firewire-core to reset the bus during shutdown
    caused a spurious "firewire_ohci: failed to write phy reg" error
    message in the log.  Skip this message as well as the prior retry
    loop that needlessly took 100 milliseconds.

  - In the unlikely case that a PHY register was read right after card
    ejection, a bogus value was obtained and possibly acted upon.
    Instead, fail the read attempt.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>