linux-toradex.git/arch/um/drivers/hostaudio_kern.c, branch v3.4.77

Merge branch 'config' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl

2010-10-22T17:43:11+00:00

* 'config' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
  BKL: introduce CONFIG_BKL.
  dabusb: remove the BKL
  sunrpc: remove the big kernel lock
  init/main.c: remove BKL notations
  blktrace: remove the big kernel lock
  rtmutex-tester: make it build without BKL
  dvb-core: kill the big kernel lock
  dvb/bt8xx: kill the big kernel lock
  tlclk: remove big kernel lock
  fix rawctl compat ioctls breakage on amd64 and itanic
  uml: kill big kernel lock
  parisc: remove big kernel lock
  cris: autoconvert trivial BKL users
  alpha: kill big kernel lock
  isapnp: BKL removal
  s390/block: kill the big kernel lock
  hpet: kill BKL, add compat_ioctl

uml: kill big kernel lock

2010-10-19T09:29:42+00:00

Three uml device drivers still use the big kernel lock,
but all of them can be safely converted to using
a per-driver mutex instead. Most likely this is not
even necessary, so after further review these can
and should be removed as well.

The exec system call no longer requires the BKL either,
so remove it from there, too.

Signed-off-by: Arnd Bergmann 
Cc: Jeff Dike 
Cc: user-mode-linux-devel@lists.sourceforge.net

uml: fix build

2010-10-15T21:42:24+00:00

Fix a build error introduced by d6d1b650ae6acce73d55dd024 ("param: simple
locking for sysfs-writable charp parameters").

    CC      arch/um/kernel/trap.o
  arch/um/drivers/hostaudio_kern.c: In function 'hostaudio_open':
  arch/um/drivers/hostaudio_kern.c:204: error: '__param_dsp' undeclared (first use in this function)
  arch/um/drivers/hostaudio_kern.c:204: error: (Each undeclared identifier is reported only once
  arch/um/drivers/hostaudio_kern.c:204: error: for each function it appears in.)
  arch/um/drivers/hostaudio_kern.c: In function 'hostmixer_open_mixdev':
  arch/um/drivers/hostaudio_kern.c:265: error: '__param_mixer' undeclared (first use in this function)
  arch/um/drivers/hostaudio_kern.c:272: error: '__param_dsp' undeclared (first use in this function)

Reported-by: Toralf Förster 
Tested-by: Toralf Förster 
Cc: Rusty Russell 
Cc: Takashi Iwai 
Cc: Jeff Dike 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

param: simple locking for sysfs-writable charp parameters

2010-08-11T13:34:31+00:00

Since the writing to sysfs can free the old one, we need to block that
when we access the charp variables.

Signed-off-by: Rusty Russell 
Reviewed-by: Takashi Iwai 
Tested-by: Phil Carmody 
Cc: Jeff Dike 
Cc: Dan Williams 
Cc: John W. Linville 
Cc: Jing Huang 
Cc: James E.J. Bottomley 
Cc: Greg Kroah-Hartman 
Cc: Johannes Berg 
Cc: David S. Miller 
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: libertas-dev@lists.infradead.org
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: linux-usb@vger.kernel.org

sound: push BKL into open functions

2010-07-12T15:41:05+00:00

This moves the lock_kernel() call from soundcore_open
to the individual OSS device drivers, where we can deal
with it one driver at a time if needed, or just kill
off the drivers.

All core components in ALSA already provide
adequate locking in their open()-functions
and do not require the big kernel lock, so
there is no need to add the BKL there.

Signed-off-by: Arnd Bergmann 
Signed-off-by: Takashi Iwai

uml: Convert to unlocked_ioctls to remove implicit BKL

2010-05-17T03:27:42+00:00

Convert hostaudio_ioctl and hostmixer_ioctl_mixdev to
unlocked_ioctl without pushdown.

There is nothing to protect inside, the synchronization
is made from the host already.

Signed-off-by: John Kacur 
Cc: Arnd Bergmann 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Jeff Dike 
Signed-off-by: Frederic Weisbecker

uml: fix errno return

2008-05-13T15:02:21+00:00

Error returns are negative.

Signed-off-by: Johann Felix Soden 
Signed-off-by: Jeff Dike 
Cc: WANG Cong 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

uml: arch/um/drivers formatting

2007-10-16T16:43:09+00:00

Style fixes for the rest of the drivers.  arch/um/drivers should be pretty
CodingStyle-compliant now.

Except for the ubd driver, which will have to be treated separately.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jeff Dike 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

uml: rename os_{read_write}_file_k back to os_{read_write}_file

2007-05-07T19:13:03+00:00

Rename os_{read_write}_file_k back to os_{read_write}_file, delete
the originals and their bogus infrastructure, and fix all the callers.

Signed-off-by: Jeff Dike 
Cc: Paolo 'Blaisorblade' Giarrusso 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

uml: start fixing os_read_file and os_write_file

2007-05-07T19:13:03+00:00

This patch starts the removal of a very old, very broken piece of code.  This
stems from the problem of passing a userspace buffer into read() or write() on
the host.  If that buffer had not yet been faulted in, read and write will
return -EFAULT.

To avoid this problem, the solution was to fault the buffer in before the
system call by touching the pages that hold the buffer by doing a copy-user of
a byte to each page.  This is obviously bogus, but it does usually work, in tt
mode, since the kernel and process are in the same address space and userspace
addresses can be accessed directly in the kernel.

In skas mode, where the kernel and process are in separate address spaces, it
is completely bogus because the userspace address, which is invalid in the
kernel, is passed into the system call instead of the corresponding physical
address, which would be valid.  Here, it appears that this code, on every host
read() or write(), tries to fault in a random process page.  This doesn't seem
to cause any correctness problems, but there is a performance impact.  This
patch, and the ones following, result in a 10-15% performance gain on a kernel
build.

This code can't be immediately tossed out because when it is, you can't log
in.  Apparently, there is some code in the console driver which depends on
this somehow.

However, we can start removing it by switching the code which does I/O using
kernel addresses to using plain read() and write().  This patch introduces
os_read_file_k and os_write_file_k for use with kernel buffers and converts
all call locations which use obvious kernel buffers to use them.  These
include I/O using buffers which are local variables which are on the stack or
kmalloc-ed.  Later patches will handle the less obvious cases, followed by a
mass conversion back to the original interface.

Signed-off-by: Jeff Dike 
Cc: Paolo 'Blaisorblade' Giarrusso 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds