diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2016-04-18 01:16:04 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-06-16 10:48:29 +0200 |
| commit | 7d9794e7523798e1b9422ad9f4e4d808ae5d5932 (patch) | |
| tree | 3a1a550803485049b8e8c2a434c0c9107831f3a6 /arch/sh/include/asm/atomic-llsc.h | |
| parent | 56fefbbc3f13ad8cc9f502dbc6b5c9ddc8c4395e (diff) | |
locking/atomic, arch/sh: 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: 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: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/sh/include/asm/atomic-llsc.h')
| -rw-r--r-- | arch/sh/include/asm/atomic-llsc.h | 32 |
1 files changed, 28 insertions, 4 deletions
diff --git a/arch/sh/include/asm/atomic-llsc.h b/arch/sh/include/asm/atomic-llsc.h index 33d34b16d4d6..caea2c45f6c2 100644 --- a/arch/sh/include/asm/atomic-llsc.h +++ b/arch/sh/include/asm/atomic-llsc.h @@ -48,15 +48,39 @@ static inline int atomic_##op##_return(int i, atomic_t *v) \ return temp; \ } -#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op) +#define ATOMIC_FETCH_OP(op) \ +static inline int atomic_fetch_##op(int i, atomic_t *v) \ +{ \ + unsigned long res, temp; \ + \ + __asm__ __volatile__ ( \ +"1: movli.l @%3, %0 ! atomic_fetch_" #op " \n" \ +" mov %0, %1 \n" \ +" " #op " %2, %0 \n" \ +" movco.l %0, @%3 \n" \ +" bf 1b \n" \ +" synco \n" \ + : "=&z" (temp), "=&z" (res) \ + : "r" (i), "r" (&v->counter) \ + : "t"); \ + \ + return res; \ +} + +#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op) ATOMIC_FETCH_OP(op) ATOMIC_OPS(add) ATOMIC_OPS(sub) -ATOMIC_OP(and) -ATOMIC_OP(or) -ATOMIC_OP(xor) #undef ATOMIC_OPS +#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_FETCH_OP(op) + +ATOMIC_OPS(and) +ATOMIC_OPS(or) +ATOMIC_OPS(xor) + +#undef ATOMIC_OPS +#undef ATOMIC_FETCH_OP #undef ATOMIC_OP_RETURN #undef ATOMIC_OP |