Commit Graph

39 Commits

Author SHA1 Message Date
David S. Miller 8fd90bb889 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/infiniband/hw/cxgb4/device.c

The cxgb4 conflict was simply overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-22 00:44:59 -07:00
Dan Carpenter a28d0e873d wan/x25_asy: integer overflow in x25_asy_change_mtu()
If "newmtu * 2 + 4" is too large then it can cause an integer overflow
leading to memory corruption.  Eric Dumazet suggests that 65534 is a
reasonable upper limit.

Btw, "newmtu" is not allowed to be a negative number because of the
check in dev_set_mtu(), so that's ok.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-17 16:47:50 -07:00
Tom Gundersen c835a67733 net: set name_assign_type in alloc_netdev()
Extend alloc_netdev{,_mq{,s}}() to take name_assign_type as argument, and convert
all users to pass NET_NAME_UNKNOWN.

Coccinelle patch:

@@
expression sizeof_priv, name, setup, txqs, rxqs, count;
@@

(
-alloc_netdev_mqs(sizeof_priv, name, setup, txqs, rxqs)
+alloc_netdev_mqs(sizeof_priv, name, NET_NAME_UNKNOWN, setup, txqs, rxqs)
|
-alloc_netdev_mq(sizeof_priv, name, setup, count)
+alloc_netdev_mq(sizeof_priv, name, NET_NAME_UNKNOWN, setup, count)
|
-alloc_netdev(sizeof_priv, name, setup)
+alloc_netdev(sizeof_priv, name, NET_NAME_UNKNOWN, setup)
)

v9: move comments here from the wrong commit

Signed-off-by: Tom Gundersen <teg@jklm.no>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-15 16:12:48 -07:00
Joe Perches 1d5d1fdc52 wan: Remove unnecessary alloc/OOM messages
alloc failures already get standardized OOM
messages and a dump_stack.

Hoist assigns from if tests.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-04 13:22:34 -05:00
Joe Perches c2fd03a011 drivers: net: Remove casts to same type
Adding casts of objects to the same type is unnecessary
and confusing for a human reader.

For example, this cast:

        int y;
        int *p = (int *)&y;

I used the coccinelle script below to find and remove these
unnecessary casts.  I manually removed the conversions this
script produces of casts with __force, __iomem and __user.

@@
type T;
T *p;
@@

-       (T *)p
+       p

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-06 09:31:33 -07:00
David Howells 9ffc93f203 Remove all #inclusions of asm/system.h
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: David Howells <dhowells@redhat.com>
2012-03-28 18:30:03 +01:00
Joe Perches e404decb0f drivers/net: Remove unnecessary k.alloc/v.alloc OOM messages
alloc failures use dump_stack so emitting an additional
out-of-memory message is an unnecessary duplication.

Remove the allocation failure messages.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-01-31 16:20:21 -05:00
stephen hemminger d97a077a15 wan: make LAPB callbacks const
This is compile tested only.
Suggested by dumpster diving in PAX.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-09-16 19:20:20 -04:00
Joe Perches 23efcb738e wan: Update to current logging forms
Use pr_fmt, pr_<level> and netdev_<level> as appropriate.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-06-27 00:09:47 -07:00
Linus Torvalds eed5ee1a3a Merge branch 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6
* 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6:
  serial: mfd: adjust the baud rate setting
  TTY: open/hangup race fixup
  TTY: don't allow reopen when ldisc is changing
  NET: wan/x25, fix ldisc->open retval
  TTY: ldisc, fix open flag handling
  serial8250: Mark console as CON_ANYTIME
2010-12-02 12:58:16 -08:00
Jiri Slaby 6a20bd45fd NET: wan/x25, fix ldisc->open retval
We should never return positive values from ldisc->open, tty layer
doesn't (and never did) expect that.

If we do that, weird things like warnings in tty_ldisc_close happen.

Not sure if dev->base_addr is used somehow now.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Andrew Hendry <andrew.hendry@gmail.com>
Cc: linux-x25@vger.kernel.org
Tested-by: Sergey Lapin <slapin@ossfans.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-29 14:51:54 -08:00
Jiri Slaby 03fe5f3ef7 NET: wan/x25_asy, move lapb_unregister to x25_asy_close_tty
We register lapb when tty is created, but unregister it only when the
device is UP. So move the lapb_unregister to x25_asy_close_tty after
the device is down.

The old behaviour causes ldisc switching to fail each second attempt,
because we noted for us that the device is unused, so we use it the
second time, but labp layer still have it registered, so it fails
obviously.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reported-by: Sergey Lapin <slapin@ossfans.org>
Cc: Andrew Hendry <andrew.hendry@gmail.com>
Tested-by: Sergey Lapin <slapin@ossfans.org>
Tested-by: Mikhail Ulyanov <ulyanov.mikhail@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-28 11:43:47 -08:00
Eric Dumazet 807540baae drivers/net: return operator cleanup
Change "return (EXPR);" to "return EXPR;"

return is not a function, parentheses are not required.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-26 18:34:29 -07:00
Huang Weiyi ca7335948e X25: remove duplicated #include
Remove duplicated #include('s) in drivers/net/wan/x25_asy.c

Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-04 16:14:48 -07:00
andrew hendry 7eeeacf0b5 X25: Use identifiers for x25 async device to x25 interface
Change magic numbers to identifiers for X25 interface.

Signed-off-by: Andrew Hendry <andrew.hendry@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-22 16:12:49 -07:00
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Joe Perches 8e95a2026f drivers/net: Move && and || to end of previous line
Only files where David Miller is the primary git-signer.
wireless, wimax, ixgbe, etc are not modified.

Compile tested x86 allyesconfig only
Not all files compiled (not x86 compatible)

Added a few > 80 column lines, which I ignored.
Existing checkpatch complaints ignored.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-03 13:18:01 -08:00
Arnd Bergmann 9646e7ce3d net, compat_ioctl: handle socket ioctl abuses in tty drivers
Slip and a few other drivers use the same ioctl numbers on
tty devices that are normally meant for sockets. This causes
problems with our compat_ioctl handling that tries to convert
the data structures in a different format.

Fortunately, these five drivers all use 32 bit compatible
data structures in the ioctl numbers, so we can just add
a trivial compat_ioctl conversion function to each of them.

SIOCSIFENCAP and SIOCGIFENCAP do not need to live in
fs/compat_ioctl.c after this any more, and they are not
used on any sockets.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-06 22:52:38 -08:00
Stephen Hemminger d71a674922 wan: convert drivers to netdev_tx_t
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-01 01:13:28 -07:00
Patrick McHardy 6ed106549d net: use NETDEV_TX_OK instead of 0 in ndo_start_xmit() functions
This patch is the result of an automatic spatch transformation to convert
all ndo_start_xmit() return values of 0 to NETDEV_TX_OK.

Some occurences are missed by the automatic conversion, those will be
handled in a seperate patch.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-05 19:16:04 -07:00
Stephen Hemminger 48f26ad5c0 x25_asy: convert to net_device_ops
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-21 22:37:57 -07:00
Stephen Hemminger 6a8eba3bf4 x25_asy: convert to internal net_device_stats
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-21 22:37:57 -07:00
Hannes Eder 7b3dfa11cd drivers/net/wan: fix sparse warning: make symbol static
Fix this sparse warning:

  drivers/net/wan/x25_asy.c:623:5: warning: symbol 'x25_asy_esc' was not declared. Should it be static?

Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-26 00:11:21 -08:00
Alan Cox d2b88814c6 tty: driverdata and discdata are void *
Remove all the extra casting while we are cleaning up

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-05 22:32:22 -08:00
Alan Cox 8a1ec21e6c tty: Flags should be accessed via the foo_bit interfaces
We have various drivers that poke around directly and we need to clean this
up before it causes problems.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-05 22:31:52 -08:00
Wang Chen 8f15ea42b6 netdevice: safe convert to netdev_priv() #part-3
We have some reasons to kill netdev->priv:
1. netdev->priv is equal to netdev_priv().
2. netdev_priv() wraps the calculation of netdev->priv's offset, obviously
   netdev_priv() is more flexible than netdev->priv.
But we cann't kill netdev->priv, because so many drivers reference to it
directly.

This patch is a safe convert for netdev->priv to netdev_priv(netdev).
Since all of the netdev->priv is only for read.
But it is too big to be sent in one mail.
I split it to 4 parts and make every part smaller than 100,000 bytes,
which is max size allowed by vger.

Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-12 23:38:36 -08:00
David S. Miller babcda74e9 drivers/net: Kill now superfluous ->last_rx stores.
The generic packet receive code takes care of setting
netdev->last_rx when necessary, for the sake of the
bonding ARP monitor.

Drivers need not do it any more.

Some cases had to be skipped over because the drivers
were making use of the ->last_rx value themselves.

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-03 21:11:17 -08:00
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
Ben Hutchings 3e3cda96d0 Hold RTNL while calling dev_close()
dev_close() must be called holding the RTNL.  Compile-tested only.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2008-06-27 01:31:52 -04:00
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
S.Çağlar Onur 91a0736531 x25_asy.c: silence compiler warning
Commit 11b0cc3a4a ("x25_asy: Fix ref count
rule violation") introduced the warning

  drivers/net/wan/x25_asy.c: In function `x25_asy_open_tty':
  drivers/net/wan/x25_asy.c:557: warning: unused variable `ld'

Signed-off-by: S.Çağlar Onur <caglar@pardus.org.tr>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-09 23:27:01 -08:00
Alan Cox 11b0cc3a4a x25_asy: Fix ref count rule violation
x25_asy does not take an ldisc reference before calling the flush method.
Fix it to use the helper function we provide.

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Krzysztof Halasa <khc@pm.waw.pl>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 15:33:33 -08:00
Alan Cox d0127539ea [TTY]: Use tty_mode_ioctl() in network drivers.
We conciously make a change here - we permit mode and speed setting to
be done in things like SLIP mode. There isn't actually a technical
reason to disallow this. It's usually a silly thing to do but we can
do it and soemone might wish to do so.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-11-07 04:14:24 -08:00
Yoann Padioleau dd00cc486a some kmalloc/memset ->kzalloc (tree wide)
Transform some calls to kmalloc/memset to a single kzalloc (or kcalloc).

Here is a short excerpt of the semantic patch performing
this transformation:

@@
type T2;
expression x;
identifier f,fld;
expression E;
expression E1,E2;
expression e1,e2,e3,y;
statement S;
@@

 x =
- kmalloc
+ kzalloc
  (E1,E2)
  ...  when != \(x->fld=E;\|y=f(...,x,...);\|f(...,x,...);\|x=E;\|while(...) S\|for(e1;e2;e3) S\)
- memset((T2)x,0,E1);

@@
expression E1,E2,E3;
@@

- kzalloc(E1 * E2,E3)
+ kcalloc(E1,E2,E3)

[akpm@linux-foundation.org: get kcalloc args the right way around]
Signed-off-by: Yoann Padioleau <padator@wanadoo.fr>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Acked-by: Russell King <rmk@arm.linux.org.uk>
Cc: Bryan Wu <bryan.wu@analog.com>
Acked-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Dave Airlie <airlied@linux.ie>
Acked-by: Roland Dreier <rolandd@cisco.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Acked-by: Pierre Ossman <drzeus-list@drzeus.cx>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: "David S. Miller" <davem@davemloft.net>
Acked-by: Greg KH <greg@kroah.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:50 -07:00
Robert P. J. Day 5cbded585d [PATCH] getting rid of all casts of k[cmz]alloc() calls
Run this:

	#!/bin/sh
	for f in $(grep -Erl "\([^\)]*\) *k[cmz]alloc" *) ; do
	  echo "De-casting $f..."
	  perl -pi -e "s/ ?= ?\([^\)]*\) *(k[cmz]alloc) *\(/ = \1\(/" $f
	done

And then go through and reinstate those cases where code is casting pointers
to non-pointers.

And then drop a few hunks which conflicted with outstanding work.

Cc: Russell King <rmk@arm.linux.org.uk>, Ian Molton <spyro@f2s.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Greg KH <greg@kroah.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Karsten Keil <kkeil@suse.de>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Ian Kent <raven@themaw.net>
Cc: Steven French <sfrench@us.ibm.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: Jaroslav Kysela <perex@suse.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-13 09:05:58 -08:00
Alan Cox 33f0f88f1c [PATCH] TTY layer buffering revamp
The API and code have been through various bits of initial review by
serial driver people but they definitely need to live somewhere for a
while so the unconverted drivers can get knocked into shape, existing
drivers that have been updated can be better tuned and bugs whacked out.

This replaces the tty flip buffers with kmalloc objects in rings. In the
normal situation for an IRQ driven serial port at typical speeds the
behaviour is pretty much the same, two buffers end up allocated and the
kernel cycles between them as before.

When there are delays or at high speed we now behave far better as the
buffer pool can grow a bit rather than lose characters. This also means
that we can operate at higher speeds reliably.

For drivers that receive characters in blocks (DMA based, USB and
especially virtualisation) the layer allows a lot of driver specific
code that works around the tty layer with private secondary queues to be
removed. The IBM folks need this sort of layer, the smart serial port
people do, the virtualisers do (because a virtualised tty typically
operates at infinite speed rather than emulating 9600 baud).

Finally many drivers had invalid and unsafe attempts to avoid buffer
overflows by directly invoking tty methods extracted out of the innards
of work queue structs. These are no longer needed and all go away. That
fixes various random hangs with serial ports on overflow.

The other change in here is to optimise the receive_room path that is
used by some callers. It turns out that only one ldisc uses receive room
except asa constant and it updates it far far less than the value is
read. We thus make it a variable not a function call.

I expect the code to contain bugs due to the size alone but I'll be
watching and squashing them and feeding out new patches as it goes.

Because the buffers now dynamically expand you should only run out of
buffering when the kernel runs out of memory for real.  That means a lot of
the horrible hacks high performance drivers used to do just aren't needed any
more.

Description:

tty_insert_flip_char is an old API and continues to work as before, as does
tty_flip_buffer_push() [this is why many drivers dont need modification].  It
does now also return the number of chars inserted

There are also

tty_buffer_request_room(tty, len)

which asks for a buffer block of the length requested and returns the space
found.  This improves efficiency with hardware that knows how much to
transfer.

and tty_insert_flip_string_flags(tty, str, flags, len)

to insert a string of characters and flags

For a smart interface the usual code is

    len = tty_request_buffer_room(tty, amount_hardware_says);
    tty_insert_flip_string(tty, buffer_from_card, len);

More description!

At the moment tty buffers are attached directly to the tty.  This is causing a
lot of the problems related to tty layer locking, also problems at high speed
and also with bursty data (such as occurs in virtualised environments)

I'm working on ripping out the flip buffers and replacing them with a pool of
dynamically allocated buffers.  This allows both for old style "byte I/O"
devices and also helps virtualisation and smart devices where large blocks of
data suddenely materialise and need storing.

So far so good.  Lots of drivers reference tty->flip.*.  Several of them also
call directly and unsafely into function pointers it provides.  This will all
break.  Most drivers can use tty_insert_flip_char which can be kept as an API
but others need more.

At the moment I've added the following interfaces, if people think more will
be needed now is a good time to say

 int tty_buffer_request_room(tty, size)

Try and ensure at least size bytes are available, returns actual room (may be
zero).  At the moment it just uses the flipbuf space but that will change.
Repeated calls without characters being added are not cumulative.  (ie if you
call it with 1, 1, 1, and then 4 you'll have four characters of space.  The
other functions will also try and grow buffers in future but this will be a
more efficient way when you know block sizes.

 int tty_insert_flip_char(tty, ch, flag)

As before insert a character if there is room.  Now returns 1 for success, 0
for failure.

 int tty_insert_flip_string(tty, str, len)

Insert a block of non error characters.  Returns the number inserted.

 int tty_prepare_flip_string(tty, strptr, len)

Adjust the buffer to allow len characters to be added.  Returns a buffer
pointer in strptr and the length available.  This allows for hardware that
needs to use functions like insl or mencpy_fromio.

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: John Hawkes <hawkes@sgi.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10 08:01:59 -08:00
Alexey Dobriyan 64ccd715d3 [PATCH] Convert users to tty_unregister_ldisc()
tty_register_ldisc(N_FOO, NULL) => tty_unregister_ldisc(N_FOO)

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-23 09:45:36 -07:00
Jesper Juhl 6a5d362120 [WAN]: kfree of NULL pointer is valid
kfree(0) is perfectly valid, checking pointers for NULL before calling 
kfree() on them is redundant. The patch below cleans away a few such 
redundant checks (and while I was around some of those bits I couldn't 
stop myself from making a few tiny whitespace changes as well).

Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
Acked-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-03 14:33:27 -07:00
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00