Based upon feedback from Linus:
- Touch on xchg(), cmpxchg() and spinlocks lightly.
- Discuss atomic_dec_and_test()
- Add some historical platform notes.
Signed-off-by: David S. Miller <davem@davemloft.net>

read_unlock should order all previous memory operations
before the atomic counter update to drop the lock.
The debugging version of write_unlock had a similar error.
Signed-off-by: David S. Miller <davem@davemloft.net>

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

into ppc970.osdl.org:/home/torvalds/v2.6/linux

into ppc970.osdl.org:/home/torvalds/v2.6/linux

into ppc970.osdl.org:/home/torvalds/v2.6/linux

Signed-off-by: Tejun Heo <tj@home-tj.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Signed-off-by: Tejun Heo <tj@home-tj.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Signed-off-by: Tejun Heo <tj@home-tj.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Signed-off-by: Tejun Heo <tj@home-tj.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Signed-off-by: Tejun Heo <tj@home-tj.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Signed-off-by: Tejun Heo <tj@home-tj.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Signed-off-by: Tejun Heo <tj@home-tj.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Signed-off-by: Tejun Heo <tj@home-tj.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Signed-off-by: Tejun Heo <tj@home-tj.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

bart: while at it do whitespace cleanup and add missing FIXME
Signed-off-by: Tejun Heo <tj@home-tj.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Signed-off-by: Tejun Heo <tj@home-tj.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

->init_chipset is optional
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

bart: do small whitespace cleanup while at it
Signed-off-by: Tejun Heo <tj@home-tj.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Signed-off-by: Tejun Heo <tj@home-tj.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

bart: s/byte/u8/
Signed-off-by: Tejun Heo <tj@home-tj.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

bart: leave BUSCLOCK() alone for now
Signed-off-by: Tejun Heo <tj@home-tj.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

From: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>

On Fri, 4 Feb 2005, Al Viro wrote:

> BTW, ide-lib.c code that triggers the ICE happens to be completely broken.
> Jens, it's your patch from September 2002 - what used to be
>        if ((stat & (BUSY_STAT|ERR_STAT)) == ERR_STAT) {
> became
>        if ((status.all & (status.b.bsy|status.b.check)) == status.b.check) {
> and that's *not* an equivalent transformation.  Fixing it doesn't get rid
> of ICE, but it certainly deserves fixing.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Return success if no device is connected to the interface.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

into kernel.bkbits.net:/home/davem/sparc-2.6

into kernel.bkbits.net:/home/davem/net-2.6

into kernel.bkbits.net:/home/davem/sparc-2.6

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

In light of the recent discussion about sk_buff, I think we need
the following patch for dst_entry.  This adds a memory barrier
before dst_release drops the refcnt, and a read memory barrier
before dst_destroy starts destroying the entry.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

Also kill kfree_skb_fast(), that is a relic from fast switching
which was killed off years ago.

The bug is that in the case where we do the atomic_read()
optimization, we need to make sure that reads of skb state
later in __kfree_skb() processing (particularly the skb->list
BUG check) are not reordered to occur before the counter
read by the cpu.

Thanks to Olaf Kirch and Anton Blanchard for discovering
and helping fix this bug.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

into ppc970.osdl.org:/home/torvalds/v2.6/linux

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

1) Correct memory barriers.  Routines not returning a value need
   no memory barriers, however routines returning values do need
   them.
2) Actually implement non-atomic ext2 bitops.

Thanks to Anton Blanchard for pointing out the memory barrier
requirements.
Signed-off-by: David S. Miller <davem@davemloft.net>

Georgi Guninski has some tools that warn about bad user accesses.
This one was harmless, but still..

The patch fixes the noexec= boot option on x86_64 to actually work when
other options come after it.

Credits (if any ;)) should go to Matt Zimmerman and Colin Watson for
spotting the problem and providing/testing the fix.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

This patch fixes a compile problem on x86-64 when CONFIG_PM is turned off. 
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

The Pentium4 models 0&1 have a longer MSR_EBC_FREQUENCY_ID register as the
models 2&3, so the bit shift must be bigger.
Signed-off-by: Matthias-Christian Ott <matthias.christian@tiscali.de>
Signed-off-by: Dominik Brodowski <linux@brodo.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>