diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2016-04-18 01:16:08 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-06-16 10:48:23 +0200 |
| commit | e87fc0ec070554e34812be68267a9450271868d6 (patch) | |
| tree | d99ccf1052722bd4e699414851673768f4004e8f /arch/blackfin/mach-bf561 | |
| parent | 1a6eafacd4811cdc1b138faee858527658eee4e1 (diff) | |
| download | linux-e87fc0ec070554e34812be68267a9450271868d6.tar.bz2 | |
locking/atomic, arch/blackfin: Implement atomic_fetch_{add,sub,and,or,xor}()
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: Peter 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: Steven Miao <realmz6@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: adi-buildroot-devel@lists.sourceforge.net
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/blackfin/mach-bf561')
| -rw-r--r-- | arch/blackfin/mach-bf561/atomic.S | 43 |
1 files changed, 31 insertions, 12 deletions
diff --git a/arch/blackfin/mach-bf561/atomic.S b/arch/blackfin/mach-bf561/atomic.S index 26fccb5568b9..1e2989c5d6b2 100644 --- a/arch/blackfin/mach-bf561/atomic.S +++ b/arch/blackfin/mach-bf561/atomic.S @@ -607,6 +607,28 @@ ENDPROC(___raw_atomic_add_asm) /* * r0 = ptr + * r1 = value + * + * ADD a signed value to a 32bit word and return the old value atomically. + * Clobbers: r3:0, p1:0 + */ +ENTRY(___raw_atomic_xadd_asm) + p1 = r0; + r3 = r1; + [--sp] = rets; + call _get_core_lock; + r3 = [p1]; + r2 = r3 + r2; + [p1] = r2; + r1 = p1; + call _put_core_lock; + r0 = r3; + rets = [sp++]; + rts; +ENDPROC(___raw_atomic_add_asm) + +/* + * r0 = ptr * r1 = mask * * AND the mask bits from a 32bit word and return the old 32bit value @@ -618,10 +640,9 @@ ENTRY(___raw_atomic_and_asm) r3 = r1; [--sp] = rets; call _get_core_lock; - r2 = [p1]; - r3 = r2 & r3; - [p1] = r3; - r3 = r2; + r3 = [p1]; + r2 = r2 & r3; + [p1] = r2; r1 = p1; call _put_core_lock; r0 = r3; @@ -642,10 +663,9 @@ ENTRY(___raw_atomic_or_asm) r3 = r1; [--sp] = rets; call _get_core_lock; - r2 = [p1]; - r3 = r2 | r3; - [p1] = r3; - r3 = r2; + r3 = [p1]; + r2 = r2 | r3; + [p1] = r2; r1 = p1; call _put_core_lock; r0 = r3; @@ -666,10 +686,9 @@ ENTRY(___raw_atomic_xor_asm) r3 = r1; [--sp] = rets; call _get_core_lock; - r2 = [p1]; - r3 = r2 ^ r3; - [p1] = r3; - r3 = r2; + r3 = [p1]; + r2 = r2 ^ r3; + [p1] = r2; r1 = p1; call _put_core_lock; r0 = r3; |