This reverts the tty layer change to use per-tty locking, because it's
not correct yet, and fixing it will require some more deep surgery.

The main revert is d29f3ef3 ("tty_lock: Localise the lock"), but
there are several smaller commits that built upon it, they also get
reverted here. The list of reverted commits is:

  fde86d31 - tty: add lockdep annotations
  8f6576ad - tty: fix ldisc lock inversion trace
  d3ca8b64 - pty: Fix lock inversion
  b1d679af - tty: drop the pty lock during hangup
  abcefe5f - tty/amiserial: Add missing argument for tty_unlock()
  fd11b42e - cris: fix missing tty arg in wait_event_interruptible_tty call
  d29f3ef3 - tty_lock: Localise the lock

The revert had a trivial conflict in the 68360serial.c staging driver
that got removed in the meantime.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In each remaining case the tty_lock is associated with a specific tty. This
means we can now lock on a per tty basis. We do need tty_lock_pair() for
the pty case. Uglier but still a step in the right direction.

[fixed up calls in 3 missing drivers - gregkh]
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove all #inclusions of asm/system.h preparatory to splitting and killing
it.  Performed with the following command:

perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *`
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Checking if tty->index is in bounds is not needed. The tty has the
index set in the initial open. This is done in get_tty_driver. And it
can be only in interval <0,driver->num).

So remove the tests which check exactly this interval. Some are
left untouched as they check against the current backing device count.
(Leaving apart that the check is racy in most of the cases.)
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

All num, magic and owner are set by alloc_tty_driver. No need to
re-set them on each allocation site.

pti driver sets something different to what it passes to
alloc_tty_driver. It is not a bug, since we don't use the lines
parameter in any way. Anyway this is fixed, and now we do the right
thing.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Acked-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

module_param(bool) used to counter-intuitively take an int.  In
fddd5201 (mid-2009) we allowed bool or int/unsigned int using a messy
trick.

It's time to remove the int/unsigned int option.  For this version
it'll simply give a warning, but it'll break next kernel version.
Acked-by: NMauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Redundant comment line was removed
Signed-off-by: NEdwin van Vliet <edwin@cheatah.nl>
Reviewed-by: NJesper Juhl <jj@chaosbits.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

remove invalid location line in each file header after location
moved from driver/char to driver/tty
Signed-off-by: NJovi Zhang <bookjovi@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

As planned by Arnd Bergmann, this moves the following drivers from
drivers/char/ to drivers/tty/ as that's where they really belong:
	amiserial
	nozomi
	synclink
	rocket
	cyclades
	moxa
	mxser
	isicom
	bfin_jtag_comm

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Only oddities here are a couple of drivers that bogusly called the ldisc
helpers instead of returning -ENOIOCTLCMD. Fix the bug and the rest goes
away.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Doing tiocmget was such fun we should do tiocmset as well for the same
reasons
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

We don't actually need this and it causes problems for internal use of
this functionality. Currently there is a single use of the FILE * pointer.
That is the serial core which uses it to check tty_hung_up_p. However if
that is true then IO_ERROR is also already set so the check may be removed.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Again basically cut and paste

Convert the main driver set to use the hooks for GICOUNT
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Most tty drivers may block while opening a device.
Since this possibly depends on another thread
closing it first and both threads may need the BTM,
we need to release it here.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

We don't need it while waiting and we can lock the ioctls using the port
mutex. While at it eliminate use of the hangup mutex and switch to the port
mutex.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Stanse found a potential null dereference in mgsl_put_char and
mgsl_write. There is a check for tty being NULL, but it is
dereferenced earlier.

Actually, tty cannot be NULL in .write and .put_char, so remove
the tests.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

* Remove smp_lock.h from files which don't need it (including some headers!)
* Add smp_lock.h to files which do need it
* Make smp_lock.h include conditional in hardirq.h
  It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT

  This will make hardirq.h inclusion cheaper for every PREEMPT=n config
  (which includes allmodconfig/allyesconfig, BTW)
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Some drivers implement this internally, others miss it out. Push the
behaviour into the core code as that way everyone will do it consistently.

Update the dtr rts method to raise or lower depending upon flags. Having a
single method in this style fits most of the implementations more cleanly than
two funtions.

We need this in place before we tackle the USB side
Signed-off-by: NAlan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Also remove unneeded last_rx update from Synclink drivers.
Synclink part mostly by Stephen Hemminger.
Signed-off-by: NKrzysztof Hałasa <khc@pm.waw.pl>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

disc_data and driver_data are void *
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Again this is a lot of common code we can unify
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Start sucking more commonality out of the drivers into a single piece of
core code.
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This moves another per device special out of what should be shared open
wait paths into private methods
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is the first step to generalising the various pieces of waiting logic
duplicated in all sorts of serial drivers.
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NKrzysztof Hałasa <khc@pm.waw.pl>

Some hardware needs to do break handling itself and may have partial
support only. Make break_ctl return an error code. Add a tty driver flag
so you can indicate driver hardware side break support.
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Move more bits into the tty_port structure
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Switch the synclink ports to use the new tty_port structure
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Move the line disciplines towards a conventional ->ops arrangement.  For
the moment the actual 'tty_ldisc' struct in the tty is kept as part of
the tty struct but this can then be changed if it turns out that when it
all settles down we want to refcount ldiscs separately to the tty.

Pull the ldisc code out of /proc and put it with our ldisc code.
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There is no point in using separate net_device_stats structs when
the one in struct net_device is present. Compiles.
Signed-off-by: NKrzysztof Hałasa <khc@pm.waw.pl>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Repair the effects of

commit 55da7789
Author: Alan Cox <alan@lxorguk.ukuu.org.uk>
Date:   Wed Apr 30 00:54:07 2008 -0700

    synclink series: switch to int put_char method
Signed-off-by: NAlan Cox <alan@redhat.com>
    Cc: Paul Fulghum <paulkf@microgate.com>
    Cc: Jiri Slaby <jirislaby@gmail.com>

drivers/char/synclink_gt.c: In function 'put_char':
drivers/char/synclink_gt.c:919: warning: 'ret' may be used uninitialized in this function

and do some whitespace repair and unneeded-cast-removal in there as well.

Cc: Paul Fulghum <paulkf@microgate.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Simple search/replace except for synclink.c where I noticed a real bug and
fixed it too.  It was doing NULL + offset, then checking for NULL if the remap
failed.
Signed-off-by: NAlan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Acked-by: NJiri Slaby <jirislaby@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAlan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

- Stop drivers calling their own flush method indirectly, it obfuscates code
  and it will change soon anyway

- A few more lock_kernel paths temporarily needed in some driver internal
  waiting code

- Remove private put_char method that does a write call for one char - we
  have that anyway

- Most but not yet all of the termios copy under lock fixing (some has other
  dependencies to follow)

- Note a few locking bugs in drivers found in the process

- Kill remaining [ab]users of TIOCG/SSOFTCAR in the driver, these must go to
  fix the termios locking
Signed-off-by: NAlan Cox <alan@redhat.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

As these are quite complex I've simply pushed the BKL down into the ioctl
handler not tried to do anything neater.
Signed-off-by: NAlan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove more TRUE/FALSE defines and uses
Remove == TRUE tests
Convert BOOLEAN to bool
Convert int to bool where appropriate
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NPaul Fulghum <paulkf@microgate.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>