Commit Graph

68 Commits

Author SHA1 Message Date
Alan Cox
c65c9bc3ef tty: rewrite the ldisc locking
There are several pretty much unfixable races in the old ldisc code, especially
with respect to pty behaviour and also to hangup. It's easier to rewrite the
code than simply try and patch it up.

This patch
- splits the ldisc from the tty (so we will be able to refcount it more cleanly
  later)
- introduces a mutex lock for ldisc changing on an active device
- fixes the complete mess that hangup caused
- implements hopefully correct setldisc/close/hangup locking

There are still some problems around pty pairs that have always been there but
at least it is now possible to understand the code and fix further problems.

This fixes the following known bugs
- hang up can leak ldisc references
- hang up may not call open/close on ldisc in a matched way
- pty/tty pairs can deadlock during an ldisc change
- reading the ldisc proc files can cause every ldisc to be loaded

and probably a few other of the mysterious ldisc race reports.

I'm sure it also adds the odd new one.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:51:01 -07:00
Alexey Dobriyan
cdda7cd92b proc tty: switch ip2 to ->proc_fops
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01 08:59:08 -07:00
Greg Kroah-Hartman
03457cd455 device create: char: convert device_create_drvdata to device_create
Now that device_create() has been audited, rename things back to the
original call to be sane.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-10-16 09:24:42 -07:00
Alan Cox
7d7b93c145 tty: kref the tty driver object
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13 09:51:42 -07:00
Akinobu Mita
9d020a2e5f ip2: avoid add_timer with pending timer
add_timer() is not supposed to be called when the timer is pending.
ip2 driver attempts to avoid that condition by setting and resetting
a flag (TimerOn) in timer function. But there is some gap between
add_timer() and setting TimerOn.

This patch fix this problem by using mod_timer() and remove TimerOn
which has been unnecessary by this change.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13 09:51:39 -07:00
Jiri Slaby
f1ddfd9502 ip2: init/deinit cleanup
Cleanup of module_init/exit:
- mostly whitespace
- remove empty functions
- replace c++ comments
- remove useless prints (module loaded, unloaded)
- mark the calls as __exit and __init
- use break; and return; to save some indent levels after it
- note resource leakage

It's still mess, but now it's readable.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13 09:51:39 -07:00
Jiri Slaby
7ccd7020ef ip2: fix sparse warnings
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13 09:51:39 -07:00
Jiri Slaby
cf176bc302 ip2: cleanup globals
- do not init .bss zeroed data to zero again (by memset or
  explicit assignment)
- use char [] instead of char * for string constants

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13 09:51:39 -07:00
Jiri Slaby
47babd4c6a Char: merge ip2main and ip2base
It's pretty useless to have one setup() function separated along with
module_init() which only calls a function from ip2main anyway. Get rid
of ip2base.

Remove also checks of always-true now.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13 09:51:39 -07:00
Alan Cox
47be36a24d ip2: push BKL down for the firmware interface
(The tty side is already done)

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 10:53:43 -07:00
Greg Kroah-Hartman
47aa5793f7 device create: char: convert device_create to device_create_drvdata
device_create() is race-prone, so use the race-free
device_create_drvdata() instead as device_create() is going away.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-21 21:54:41 -07:00
Alan Cox
a352def21a tty: Ldisc revamp
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: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-20 17:12:34 -07:00
Linus Torvalds
5a86102248 Merge branch 'for-2.6.27' of git://git.infradead.org/users/dwmw2/firmware-2.6
* 'for-2.6.27' of git://git.infradead.org/users/dwmw2/firmware-2.6: (64 commits)
  firmware: convert sb16_csp driver to use firmware loader exclusively
  dsp56k: use request_firmware
  edgeport-ti: use request_firmware()
  edgeport: use request_firmware()
  vicam: use request_firmware()
  dabusb: use request_firmware()
  cpia2: use request_firmware()
  ip2: use request_firmware()
  firmware: convert Ambassador ATM driver to request_firmware()
  whiteheat: use request_firmware()
  ti_usb_3410_5052: use request_firmware()
  emi62: use request_firmware()
  emi26: use request_firmware()
  keyspan_pda: use request_firmware()
  keyspan: use request_firmware()
  ttusb-budget: use request_firmware()
  kaweth: use request_firmware()
  smctr: use request_firmware()
  firmware: convert ymfpci driver to use firmware loader exclusively
  firmware: convert maestro3 driver to use firmware loader exclusively
  ...

Fix up trivial conflicts with BKL removal in drivers/char/dsp56k.c and
drivers/char/ip2/ip2main.c manually.
2008-07-14 16:54:07 -07:00
Jonathan Corbet
2fceef397f Merge commit 'v2.6.26' into bkl-removal 2008-07-14 15:29:34 -06:00
David Woodhouse
547d8bb7dd ip2: use request_firmware()
Converted with help from Jaswinder Singh

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Acked-by: Alan Cox <alan@redhat.com>
2008-07-10 14:49:41 +01:00
Jonathan Corbet
f2b9857eee Add a bunch of cycle_kernel_lock() calls
All of the open() functions which don't need the BKL on their face may
still depend on its acquisition to serialize opens against driver
initialization.  So make those functions acquire then release the BKL to be
on the safe side.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2008-06-20 14:05:53 -06:00
Alan Cox
6089093e58 ip2: fix crashes on load/unload
This doesn't need to be two modules, and making it one cleans up the
problem

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-24 09:56:11 -07:00
Alan Cox
a6fc819ebe ip2: switch remaining direct call of ops->flush_buffer
Signed-off-by: Alan Cox <alan@redhat.com>

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:47 -07:00
Alan Cox
f34d7a5b70 tty: The big operations rework
- Operations are now a shared const function block as with most other Linux
  objects

- Introduce wrappers for some optional functions to get consistent behaviour

- Wrap put_char which used to be patched by the tty layer

- Document which functions are needed/optional

- Make put_char report success/fail

- Cache the driver->ops pointer in the tty as tty->ops

- Remove various surplus lock calls we no longer need

- Remove proc_write method as noted by Alexey Dobriyan

- Introduce some missing sanity checks where certain driver/ldisc
  combinations would oops as they didn't check needed methods were present

[akpm@linux-foundation.org: fix fs/compat_ioctl.c build]
[akpm@linux-foundation.org: fix isicom]
[akpm@linux-foundation.org: fix arch/ia64/hp/sim/simserial.c build]
[akpm@linux-foundation.org: fix kgdb]
Signed-off-by: Alan Cox <alan@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:47 -07:00
Jiri Slaby
cf1c63c3e6 Char: ip2, macros cleanup
- remove i2os.h -- there was only macro to macro renaming or useless
  stuff
- remove another uselless stuf (NULLFUNC, NULLPTR, YES, NO)
- use outb/inb directly
- use locking functions directly
- don't define another ROUNDUP, use roundup(x, 2) instead
- some comments and whitespace cleanup
- remove some commented crap
- prepend the rest by I2 prefix to not collide with rest of the world
  like in following output (pointed out by akpm)

In file included from drivers/char/ip2/ip2main.c:128:
drivers/char/ip2/i2ellis.h:608:1: warning: "COMPLETE" redefined
In file included from include/net/netns/ipv4.h:8,
                 from include/net/net_namespace.h:13,
                 from include/linux/seq_file.h:7,
                 from include/asm/machdep.h:12,
                 from include/asm/pci.h:17,
                 from include/linux/pci.h:951,
                 from drivers/char/ip2/ip2main.c:95:
include/net/inet_frag.h:28:1: warning: this is the location of the previous definition

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:44 -07:00
Jon Schindler
83e422b764 drivers/char/ip2/ip2main.c: replace init_module&cleanup_module with module_init&module_exit
Replace init_module and cleanup_module with static functions and
module_init/module_exit.

Signed-off-by: Jon Schindler <jkschind@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:44 -07:00
Alexey Dobriyan
4a5cdb5b8f proc: switch /proc/ip2mem to seq_file interface
/******************************************/
/* Remove useless comment, while I am it. */
/******************************************/

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:19 -07:00
Alexey Dobriyan
c74c120a21 proc: remove proc_root from drivers
Remove proc_root export.  Creation and removal works well if parent PDE is
supplied as NULL -- it worked always that way.

So, one useless export removed and consistency added, some drivers created
PDEs with &proc_root as parent but removed them as NULL and so on.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:18 -07:00
Jiri Slaby
3d0ae36ea9 Char: ip2, fix sparse warnings
Unlock two grabbed locks on some paths.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-02 15:28:19 -07:00
Jiri Slaby
1237a2ef31 Char: char/serial, remove SERIAL_TYPE_NORMAL redefines
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:33 -08:00
Joe Perches
8dfba4d71b drivers/char/: Spelling fixes
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
2008-02-03 17:11:42 +02:00
Jeff Garzik
6bd3bd6794 drivers/char/ip2: separate polling and irq-driven work entry points
Polling currently calls the irq handler, which loops through all the
boards, calling the work function for all polling boards with work.

irq handling loops through all the boards, finding the specific board
that applies to us, and calling the work just for that one board.

The two logics are sufficiently different to warrant different
functions, rather than being slack and calling the same function in two
different ways.

This serves to make the interrupt handler a -lot- more efficient.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2007-10-23 19:53:16 -04:00
Jeff Garzik
f3518e4ee7 drivers/char/ip2: split out irq core logic into separate function
No changes besides code movement and glue.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2007-10-23 19:53:16 -04:00
Jeff Garzik
2b0172e1c6 drivers/char/ip2: fix used-uninit'd bug
Fix bug flagged by a variable-used-uninitialized warning.

[akpm@linux-foundation.org: coding-style]
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17 08:43:01 -07:00
Mariusz Kozlowski
978550b828 drivers/char/ip2/ip2main.c: kmalloc + memset conversion to kzalloc
drivers/char/ip2/ip2main.c | 104398 -> 104346 (-52 bytes)
 drivers/char/ip2/ip2main.o | 210710 -> 210702 (-8 bytes)

Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17 08:42:50 -07:00
tonyj@suse.de
07c015e765 Convert from class_device to device in drivers/char
Convert from class_device to device in drivers/char.

Signed-off-by: Tony Jones <tonyj@suse.de>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12 14:51:04 -07:00
Andrew Morton
ad4a5bb885 ip2main warning fix
CONFIG_PCI=n:

drivers/char/ip2/ip2main.c: In function `ip2_loadmain':
drivers/char/ip2/ip2main.c:503: warning: unused variable `status'

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-31 15:39:44 -07:00
Akinobu Mita
68fc4fabca unregister_chrdev(): ignore the return value
unregister_chrdev() always returns 0.  There is no need to check the return
value.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:43 -07:00
Jiri Slaby
7126dd0562 Char: ip2, use msleep for sleeping
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:44 -07:00
Linus Torvalds
5fc7e655a5 Fix bogus 'inline' in drivers/char/ip2/i2lib.c
Not only was the function way too big to be inlined in the first place,
it was used before it was even defined.

Noted-by: Faik Uygur <faik@pardus.org.tr>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-21 11:18:26 -08:00
Eric W. Biederman
ab521dc0f8 [PATCH] tty: update the tty layer to work with struct pid
Of kernel subsystems that work with pids the tty layer is probably the largest
consumer.  But it has the nice virtue that the assiation with a session only
lasts until the session leader exits.  Which means that no reference counting
is required.  So using struct pid winds up being a simple optimization to
avoid hash table lookups.

In the long term the use of pid_nr also ensures that when we have multiple pid
spaces mixed everything will work correctly.

Signed-off-by: Eric W. Biederman <eric@maxwell.lnxi.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:32 -08:00
Jiri Slaby
40565f1962 [PATCH] Char: timers cleanup
- Use timer macros to set function and data members and to modify
  expiration time.
- Use DEFINE_TIMER for global timers and do not init them at run-time in
  these cases.
- del_timer_sync is common in most cases -- we want to wait for timer
  function if it's still running.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Dave Airlie <airlied@linux.ie>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Paul Fulghum <paulkf@microgate.com>
Cc: Kylene Jo Hall <kjhall@us.ibm.com>
Cc: Wim Van Sebroeck <wim@iguana.be>
Acked-by: Dmitry Torokhov <dtor@mail.ru>	(Input bits)
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:30 -08:00
Jiri Slaby
b963a8441c [PATCH] Char: tty_wakeup cleanup
tty_wakeup cleanup

- remove wake_up_interruptible(&tty->write_wait) surrounding
  tty_wakup(tty);
- substitute tty->ldisc.write_wakeup(tty) + wake_up() by tty_wakeup(tty);

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11 10:51:26 -08:00
Andrew Morton
2723f9603a [PATCH] ip2 warning fix
Make this:

drivers/char/ip2/ip2main.c: In function 'ip2_loadmain':
drivers/char/ip2/ip2main.c:654: warning: control may reach end of non-void function 'iiSetAddress' being inlined
drivers/char/ip2/ip2main.c:808: warning: control may reach end of non-void function 'iiInitialize' being inlined

go away.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2007-01-05 23:55:23 -08:00
Alan Cox
606d099cdd [PATCH] tty: switch to ktermios
This is the grungy swap all the occurrences in the right places patch that
goes with the updates.  At this point we have the same functionality as
before (except that sgttyb() returns speeds not zero) and are ready to
begin turning new stuff on providing nobody reports lots of bugs

If you are a tty driver author converting an out of tree driver the only
impact should be termios->ktermios name changes for the speed/property
setting functions from your upper layers.

If you are implementing your own TCGETS function before then your driver
was broken already and its about to get a whole lot more painful for you so
please fix it 8)

Also fill in c_ispeed/ospeed on init for most devices, although the current
code will do this for you anyway but I'd like eventually to lose that extra
paranoia

[akpm@osdl.org: bluetooth fix]
[mp3@de.ibm.com: sclp fix]
[mp3@de.ibm.com: warning fix for tty3270]
[hugh@veritas.com: fix tty_ioctl powerpc build]
[jdike@addtoit.com: uml: fix ->set_termios declaration]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Acked-by: Peter Oberparleiter <oberpar@de.ibm.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 08:28:57 -08:00
Josef Sipek
a7113a9662 [PATCH] struct path: convert char-drivers
Signed-off-by: Josef Sipek <jsipek@fsl.cs.sunysb.edu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 08:28:44 -08:00
Mariusz Kozlowski
652d3a3ed7 [PATCH] char: ip2 remove broken macro
This macro is broken and unused so why not remove it.

Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:43 -08:00
Mariusz Kozlowski
f6337e2af4 [PATCH] i2lib unused variable cleanup
In file included from drivers/char/ip2/ip2main.c:285:
    drivers/char/ip2/i2lib.c: In function `i2Output':
    drivers/char/ip2/i2lib.c:1019: warning: unused variable `rc'

Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:35 -08:00
David Howells
c4028958b6 WorkStruct: make allyesconfig
Fix up for make allyesconfig.

Signed-Off-By: David Howells <dhowells@redhat.com>
2006-11-22 14:57:56 +00:00
Al Viro
f061c5847b [PATCH] i2Output always takes kernel data now
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-11 11:17:07 -07:00
David Howells
7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:10:12 +01:00
Jeff Garzik
fcc7a8c463 [PATCH] drivers/char/ip2: kill unused code, label
Kill warning:

drivers/char/ip2/ip2main.c: In function ‘ip2_loadmain’:
drivers/char/ip2/ip2main.c:782: warning: label ‘out_class’ defined but not used

This driver's initialization (and cleanup of errors during init) is
extremely convoluted, and could stand to be transformed into the standard
unwinding-goto style of error cleanup.

Signed-off-by: Jeff Garzik <jeff@garzik.org>
Acked-by: Michael H. Warfield <mhw@wittsend.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03 08:03:41 -07:00
Jeff Dike
b68e31d0eb [PATCH] const struct tty_operations
As part of an SMP cleanliness pass over UML, I consted a bunch of
structures in order to not have to document their locking.  One of these
structures was a struct tty_operations.  In order to const it in UML
without introducing compiler complaints, the declaration of
tty_set_operations needs to be changed, and then all of its callers need to
be fixed.

This patch declares all struct tty_operations in the tree as const.  In all
cases, they are static and used only as input to tty_set_operations.  As an
extra check, I ran an i386 allyesconfig build which produced no extra
warnings.

53 drivers are affected.  I checked the history of a bunch of them, and in
most cases, there have been only a handful of maintenance changes in the
last six months.  serial_core.c was the busiest one that I looked at.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 07:57:14 -07:00
Alan Cox
1aff0ecafb [PATCH] ip2: use newer pci_get functions
This is one of a series of patches I plan to gradually trickle into the
tree which eliminates almost all remaining use of pci_find_* and lets me
build a pci_find_* free kernel for all but some obscure ISDN and SCSI
drivers.  This is important as all pci_find_* users are not hotplug safe -
even if they are not the device being plugged.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:23 -07:00
Chuck Short
eb0e71c7f3 [PATCH] Add Computone IntelliPort Plus serial hotplug support
Patch Description:
Add "Computone IntelliPort Plus serial" hotplug support

patch location:
http://www.kernel.org/git/?p=linux/kernel/git/bcollins/ubuntu-dapper.git;a=commitdiff;h=8c36723187c0fa5efe0e5c6a9b1e66ed4b824792

[akpm@osdl.org: cleanup]
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Chuck Short <zulcss@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10 13:24:13 -07:00