Signed-off-by: NRich Felker <dalias@libc.org>

Since all architectures have this implemented now natively, remove this
dead code.
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Implement FETCH-OP atomic primitives, these are very similar to the
existing OP-RETURN primitives we already have, except they return the
value of the atomic variable _before_ modification.

This is especially useful for irreversible operations -- such as
bitops (because it becomes impossible to reconstruct the state prior
to modification).
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

This patch makes sure that atomic_{read,set}() are at least
{READ,WRITE}_ONCE().

We already had the 'requirement' that atomic_read() should use
ACCESS_ONCE(), and most archs had this, but a few were lacking.
All are now converted to use READ_ONCE().

And, by a symmetry and general paranoia argument, upgrade atomic_set()
to use WRITE_ONCE().
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: james.hogan@imgtec.com
Cc: linux-kernel@vger.kernel.org
Cc: oleg@redhat.com
Cc: will.deacon@arm.com
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Move the now generic definitions of atomic_{set,clear}_mask() into
linux/atomic.h to avoid endless and pointless repetition.

Also, provide an atomic_andnot() wrapper for those few archs that can
implement that.
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Implement atomic logic ops -- atomic_{or,xor,and}.

These will replace the atomic_{set,clear}_mask functions that are
available on some archs.
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Use the much more reader friendly ACCESS_ONCE() instead of the cast to volatile.
This is purely a stylistic change.
Signed-off-by: NPranith Kumar <bobby.prani@gmail.com>
Acked-by: NJesper Nilsson <jesper.nilsson@axis.com>
Acked-by: NHans-Christian Egtvedt <egtvedt@samfundet.no>
Acked-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-arch@vger.kernel.org
Link: http://lkml.kernel.org/r/1411482607-20948-1-git-send-email-bobby.prani@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

SH can use the asm-generic/barrier.h implementation since that uses
smp_mb().
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-2z962by2ppzcd984ybw2mwdw@git.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

With the introduction of static keys, anything using tracepoints blows up
in the following manner:

include/trace/events/oom.h:8:13: error: initializer element is not constant
include/trace/events/oom.h:8:13: error: (near initialization for '__tracepoint_oom_score_adj_update')
include/trace/events/oom.h:8:13: error: initializer element is not constant
include/trace/events/oom.h:8:13: error: (near initialization for '__tracepoint_oom_score_adj_update.key')

This is a result of the STATIC_KEY_INIT_xxx defs wrapping ATOMIC_INIT()
which on sh includes an atomic_t typecast. Given that we don't really
need the typecast for anything anymore, the simplest solution is simply
to kill off the cast.
Signed-off-by: NNobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Disintegrate asm/system.h for SH.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
cc: linux-sh@vger.kernel.org

After changing all consumers of atomics to include <linux/atomic.h>, we
ran into some compile time errors due to this dependency chain:

linux/atomic.h
  -> asm/atomic.h
    -> asm-generic/atomic-long.h

where atomic-long.h could use funcs defined later in linux/atomic.h
without a prototype.  This patches moves the code that includes
asm-generic/atomic*.h to linux/atomic.h.

Archs that need <asm-generic/atomic64.h> need to select
CONFIG_GENERIC_ATOMIC64 from now on (some of them used to include it
unconditionally).

Compile tested on i386 and x86_64 with allnoconfig.
Signed-off-by: NArun Sharma <asharma@fb.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Acked-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is in preparation for more generic atomic primitives based on
__atomic_add_unless.
Signed-off-by: NArun Sharma <asharma@fb.com>
Signed-off-by: NHans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Reviewed-by: NEric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Acked-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>
Signed-off-by: NArun Sharma <asharma@fb.com>
Reviewed-by: NEric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In preparation for removing volatile from the atomic_t definition, this
patch adds a volatile cast to all the atomic read functions.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The LL/SC and IRQ versions were using generic stubs while the GRB version
was just reimplementing what it already had for the standard cmpxchg()
code. As we have optimized cmpxchg() implementations that are decoupled
from the atomic code, simply falling back on the generic wrapper does the
right thing. With this in place the GRB case is unaffected while the
LL/SC case gets to use its optimized cmpxchg().
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

In the past these were simply wrapping to barrier() which was sufficient
on SH SMP platforms predating SH-4A. Unfortunately due to ll/sc semantics
an explicit synco is needed in these cases, which is sorted for us by
just switching these over to smp_mb(). smp_mb() also has the benefit of
being wrapped to barrier() in the UP and non-SH4A cases, so old behaviour
is maintained for those parts.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

The existing asm-generic/atomic.h only defines the
atomic_long type. This renames it to atomic-long.h
so we have a place to add a truly generic atomic.h
that can be used on all non-SMP systems.
Signed-off-by: NRemis Lima Baima <remis.developer@googlemail.com>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NIngo Molnar <mingo@elte.hu>

This fixes up a typo in the ll/sc based cmpxchg code which apparently
wasn't getting a lot of testing due to the swapped old/new pair. With
that fixed up, the ll/sc code also starts using it and provides its own
atomic_add_unless().
Signed-off-by: NAoi Shinkai <shinkoi2005@gmail.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

The atomic_t type cannot currently be used in some header files because it
would create an include loop with asm/atomic.h.  Move the type definition
to linux/types.h to break the loop.
Signed-off-by: NMatthew Wilcox <willy@linux.intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This follows the sparc changes a439fe51.

Most of the moving about was done with Sam's directions at:

http://marc.info/?l=linux-sh&m=121724823706062&w=2

with subsequent hacking and fixups entirely my fault.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This implements kernel-level atomic rollback built on top of gUSA,
as an alternative non-IRQ based atomicity method. This is generally
a faster method for platforms that are lacking the LL/SC pairs that
SH-4A and later use, and is only supportable on legacy cores.
Signed-off-by: NStuart Menefy <stuart.menefy@st.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

We have a few different ways to do the atomic operations, so split
them out in to different headers rather than bloating atomic.h.
Kernelspace gUSA will take this up to a third implementation.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

gcc4 gets a bit pissy about the outputs:

include/asm/atomic.h: In function 'atomic_add':
include/asm/atomic.h:37: error: invalid lvalue in asm statement
include/asm/atomic.h:30: error: invalid lvalue in asm output 1
...

this ended up being a thinko anyways, so just fix it up.

Verified for proper behaviour with the older toolchains, too.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

SH-4A implements LL/SC instructions, so we implement a simple
set of atomic operations using these.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

We had quite a bit of whitespace damage, clean most of it up..
Signed-off-by: NStuart Menefy <stuart.menefy@st.com>
Signed-off-by: NArthur Othieno <a.othieno@bluewin.ch>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

add atomic_xchg() to all the architectures. Needed by the new mutex code.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NArjan van de Ven <arjan@infradead.org>

Several counters already have the need to use 64 atomic variables on 64 bit
platforms (see mm_counter_t in sched.h).  We have to do ugly ifdefs to fall
back to 32 bit atomic on 32 bit platforms.

The VM statistics patch that I am working on will also make more extensive
use of atomic64.

This patch introduces a new type atomic_long_t by providing definitions in
asm-generic/atomic.h that works similar to the c "long" type.  Its 32 bits
on 32 bit platforms and 64 bits on 64 bit platforms.

Also cleans up the determination of the mm_counter_t in sched.h.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Introduce an atomic_inc_not_zero operation.  Make this a special case of
atomic_add_unless because lockless pagecache actually wants
atomic_inc_not_negativeone due to its offset refcount.
Signed-off-by: NNick Piggin <npiggin@suse.de>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Introduce an atomic_cmpxchg operation.
Signed-off-by: NNick Piggin <npiggin@suse.de>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

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!