Commit-ID: e5857a6ed6004cac5273b8cdc189ab4b6363cfaf
Gitweb: http://git.kernel.org/tip/e5857a6ed6004cac5273b8cdc189ab4b6363cfaf
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Mon, 18 Apr 2016 01:16:05 +0200
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Thu, 16 Jun 2016 10:48:28 +0200
locking/atomic, arch/parisc: Implement atomic{,64}_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@xxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Helge Deller <deller@xxxxxx>
Cc: James E.J. Bottomley <jejb@xxxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-arch@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-parisc@xxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/parisc/include/asm/atomic.h | 65 +++++++++++++++++++++++++++++++++++-----
1 file changed, 57 insertions(+), 8 deletions(-)
diff --git a/arch/parisc/include/asm/atomic.h b/arch/parisc/include/asm/atomic.h
index 1d10999..29df1f8 100644
--- a/arch/parisc/include/asm/atomic.h
+++ b/arch/parisc/include/asm/atomic.h
@@ -121,16 +121,41 @@ static __inline__ int atomic_##op##_return(int i, atomic_t *v) \
return ret; \
}
-#define ATOMIC_OPS(op, c_op) ATOMIC_OP(op, c_op) ATOMIC_OP_RETURN(op, c_op)
+#define ATOMIC_FETCH_OP(op, c_op) \
+static __inline__ int atomic_fetch_##op(int i, atomic_t *v) \
+{ \
+ unsigned long flags; \
+ int ret; \
+ \
+ _atomic_spin_lock_irqsave(v, flags); \
+ ret = v->counter; \
+ v->counter c_op i; \
+ _atomic_spin_unlock_irqrestore(v, flags); \
+ \
+ return ret; \
+}
+
+#define ATOMIC_OPS(op, c_op) \
+ ATOMIC_OP(op, c_op) \
+ ATOMIC_OP_RETURN(op, c_op) \
+ ATOMIC_FETCH_OP(op, c_op)
ATOMIC_OPS(add, +=)
ATOMIC_OPS(sub, -=)
-ATOMIC_OP(and, &=)
-ATOMIC_OP(or, |=)
-ATOMIC_OP(xor, ^=)
+#undef ATOMIC_OPS
+#define ATOMIC_OPS(op, c_op) \
+ ATOMIC_OP(op, c_op) \
+ ATOMIC_FETCH_OP(op, c_op)
+
+#define atomic_fetch_or atomic_fetch_or
+
+ATOMIC_OPS(and, &=)
+ATOMIC_OPS(or, |=)
+ATOMIC_OPS(xor, ^=)
#undef ATOMIC_OPS
+#undef ATOMIC_FETCH_OP
#undef ATOMIC_OP_RETURN
#undef ATOMIC_OP
@@ -185,15 +210,39 @@ static __inline__ s64 atomic64_##op##_return(s64 i, atomic64_t *v) \
return ret; \
}
-#define ATOMIC64_OPS(op, c_op) ATOMIC64_OP(op, c_op) ATOMIC64_OP_RETURN(op, c_op)
+#define ATOMIC64_FETCH_OP(op, c_op) \
+static __inline__ s64 atomic64_fetch_##op(s64 i, atomic64_t *v) \
+{ \
+ unsigned long flags; \
+ s64 ret; \
+ \
+ _atomic_spin_lock_irqsave(v, flags); \
+ ret = v->counter; \
+ v->counter c_op i; \
+ _atomic_spin_unlock_irqrestore(v, flags); \
+ \
+ return ret; \
+}
+
+#define ATOMIC64_OPS(op, c_op) \
+ ATOMIC64_OP(op, c_op) \
+ ATOMIC64_OP_RETURN(op, c_op) \
+ ATOMIC64_FETCH_OP(op, c_op)
ATOMIC64_OPS(add, +=)
ATOMIC64_OPS(sub, -=)
-ATOMIC64_OP(and, &=)
-ATOMIC64_OP(or, |=)
-ATOMIC64_OP(xor, ^=)
#undef ATOMIC64_OPS
+#define ATOMIC64_OPS(op, c_op) \
+ ATOMIC64_OP(op, c_op) \
+ ATOMIC64_FETCH_OP(op, c_op)
+
+ATOMIC64_OPS(and, &=)
+ATOMIC64_OPS(or, |=)
+ATOMIC64_OPS(xor, ^=)
+
+#undef ATOMIC64_OPS
+#undef ATOMIC64_FETCH_OP
#undef ATOMIC64_OP_RETURN
#undef ATOMIC64_OP
--
To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
|