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locking/atomic, arch/sparc: Implement atomic{,64}_fetch_{add,sub,and,or,xor}()

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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>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: James Y Knight <jyknight@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: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Peter Zijlstra 2016-04-18 01:16:04 +02:00 committed by Ingo Molnar
parent 7d9794e752
commit 3a1adb23a5
6 changed files with 109 additions and 38 deletions
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1
arch/sparc/include/asm/atomic.h
View file

@ -5,4 +5,5 @@
#else
#include <asm/atomic_32.h>
#endif
#define atomic_fetch_or atomic_fetch_or
#endif

15
arch/sparc/include/asm/atomic_32.h
View file

@ -20,9 +20,10 @@
#define ATOMIC_INIT(i) { (i) }
int atomic_add_return(int, atomic_t *);
void atomic_and(int, atomic_t *);
void atomic_or(int, atomic_t *);
void atomic_xor(int, atomic_t *);
int atomic_fetch_add(int, atomic_t *);
int atomic_fetch_and(int, atomic_t *);
int atomic_fetch_or(int, atomic_t *);
int atomic_fetch_xor(int, atomic_t *);
int atomic_cmpxchg(atomic_t *, int, int);
int atomic_xchg(atomic_t *, int);
int __atomic_add_unless(atomic_t *, int, int);
@ -35,7 +36,15 @@ void atomic_set(atomic_t *, int);
#define atomic_inc(v) ((void)atomic_add_return( 1, (v)))
#define atomic_dec(v) ((void)atomic_add_return( -1, (v)))
#define atomic_fetch_or atomic_fetch_or
#define atomic_and(i, v) ((void)atomic_fetch_and((i), (v)))
#define atomic_or(i, v) ((void)atomic_fetch_or((i), (v)))
#define atomic_xor(i, v) ((void)atomic_fetch_xor((i), (v)))
#define atomic_sub_return(i, v) (atomic_add_return(-(int)(i), (v)))
#define atomic_fetch_sub(i, v) (atomic_fetch_add (-(int)(i), (v)))
#define atomic_inc_return(v) (atomic_add_return( 1, (v)))
#define atomic_dec_return(v) (atomic_add_return( -1, (v)))

16
arch/sparc/include/asm/atomic_64.h
View file

@ -28,16 +28,24 @@ void atomic64_##op(long, atomic64_t *);
int atomic_##op##_return(int, atomic_t *); \
long atomic64_##op##_return(long, atomic64_t *);
#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op)
#define ATOMIC_FETCH_OP(op) \
int atomic_fetch_##op(int, atomic_t *); \
long atomic64_fetch_##op(long, atomic64_t *);
#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

37
arch/sparc/lib/atomic32.c
View file

@ -27,6 +27,21 @@ static DEFINE_SPINLOCK(dummy);
#endif /* SMP */
#define ATOMIC_FETCH_OP(op, c_op) \
int atomic_fetch_##op(int i, atomic_t *v) \
{ \
int ret; \
unsigned long flags; \
spin_lock_irqsave(ATOMIC_HASH(v), flags); \
\
ret = v->counter; \
v->counter c_op i; \
\
spin_unlock_irqrestore(ATOMIC_HASH(v), flags); \
return ret; \
} \
EXPORT_SYMBOL(atomic_fetch_##op);
#define ATOMIC_OP_RETURN(op, c_op) \
int atomic_##op##_return(int i, atomic_t *v) \
{ \
@ -41,25 +56,15 @@ int atomic_##op##_return(int i, atomic_t *v) \
} \
EXPORT_SYMBOL(atomic_##op##_return);
#define ATOMIC_OP(op, c_op) \
void atomic_##op(int i, atomic_t *v) \
{ \
unsigned long flags; \
spin_lock_irqsave(ATOMIC_HASH(v), flags); \
\
v->counter c_op i; \
\
spin_unlock_irqrestore(ATOMIC_HASH(v), flags); \
} \
EXPORT_SYMBOL(atomic_##op);
ATOMIC_OP_RETURN(add, +=)
ATOMIC_OP(and, &=)
ATOMIC_OP(or, |=)
ATOMIC_OP(xor, ^=)
ATOMIC_FETCH_OP(add, +=)
ATOMIC_FETCH_OP(and, &=)
ATOMIC_FETCH_OP(or, |=)
ATOMIC_FETCH_OP(xor, ^=)
#undef ATOMIC_FETCH_OP
#undef ATOMIC_OP_RETURN
#undef ATOMIC_OP
int atomic_xchg(atomic_t *v, int new)
{

61
arch/sparc/lib/atomic_64.S
View file

@ -9,10 +9,11 @@
.text
/* Two versions of the atomic routines, one that
/* Three versions of the atomic routines, one that
* does not return a value and does not perform
* memory barriers, and a second which returns
* a value and does the barriers.
* memory barriers, and a two which return
* a value, the new and old value resp. and does the
* barriers.
*/
#define ATOMIC_OP(op) \
@ -43,15 +44,34 @@ ENTRY(atomic_##op##_return) /* %o0 = increment, %o1 = atomic_ptr */ \
2: BACKOFF_SPIN(%o2, %o3, 1b); \
ENDPROC(atomic_##op##_return);
#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op)
#define ATOMIC_FETCH_OP(op) \
ENTRY(atomic_fetch_##op) /* %o0 = increment, %o1 = atomic_ptr */ \
BACKOFF_SETUP(%o2); \
1: lduw [%o1], %g1; \
op %g1, %o0, %g7; \
cas [%o1], %g1, %g7; \
cmp %g1, %g7; \
bne,pn %icc, BACKOFF_LABEL(2f, 1b); \
nop; \
retl; \
sra %g1, 0, %o0; \
2: BACKOFF_SPIN(%o2, %o3, 1b); \
ENDPROC(atomic_fetch_##op);
#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
@ -83,15 +103,34 @@ ENTRY(atomic64_##op##_return) /* %o0 = increment, %o1 = atomic_ptr */ \
2: BACKOFF_SPIN(%o2, %o3, 1b); \
ENDPROC(atomic64_##op##_return);
#define ATOMIC64_OPS(op) ATOMIC64_OP(op) ATOMIC64_OP_RETURN(op)
#define ATOMIC64_FETCH_OP(op) \
ENTRY(atomic64_fetch_##op) /* %o0 = increment, %o1 = atomic_ptr */ \
BACKOFF_SETUP(%o2); \
1: ldx [%o1], %g1; \
op %g1, %o0, %g7; \
casx [%o1], %g1, %g7; \
cmp %g1, %g7; \
bne,pn %xcc, BACKOFF_LABEL(2f, 1b); \
nop; \
retl; \
mov %g1, %o0; \
2: BACKOFF_SPIN(%o2, %o3, 1b); \
ENDPROC(atomic64_fetch_##op);
#define ATOMIC64_OPS(op) ATOMIC64_OP(op) ATOMIC64_OP_RETURN(op) ATOMIC64_FETCH_OP(op)
ATOMIC64_OPS(add)
ATOMIC64_OPS(sub)
ATOMIC64_OP(and)
ATOMIC64_OP(or)
ATOMIC64_OP(xor)
#undef ATOMIC64_OPS
#define ATOMIC64_OPS(op) ATOMIC64_OP(op) ATOMIC64_FETCH_OP(op)
ATOMIC64_OPS(and)
ATOMIC64_OPS(or)
ATOMIC64_OPS(xor)
#undef ATOMIC64_OPS
#undef ATOMIC64_FETCH_OP
#undef ATOMIC64_OP_RETURN
#undef ATOMIC64_OP

17
arch/sparc/lib/ksyms.c
View file

@ -107,15 +107,24 @@ EXPORT_SYMBOL(atomic64_##op);
EXPORT_SYMBOL(atomic_##op##_return); \
EXPORT_SYMBOL(atomic64_##op##_return);
#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op)
#define ATOMIC_FETCH_OP(op) \
EXPORT_SYMBOL(atomic_fetch_##op); \
EXPORT_SYMBOL(atomic64_fetch_##op);
#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