swh:1:snp:77163734605b0ec556b01d897b7bb4a7e30d46b6
Tip revision: 64291f7db5bd8150a74ad2036f1037e6a0428df2 authored by Linus Torvalds on 30 August 2015, 18:34:09 UTC
Linux 4.2
Linux 4.2
Tip revision: 64291f7
atomic_64.S
/* atomic.S: These things are too big to do inline.
*
* Copyright (C) 1999, 2007 2012 David S. Miller (davem@davemloft.net)
*/
#include <linux/linkage.h>
#include <asm/asi.h>
#include <asm/backoff.h>
.text
/* Two 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.
*/
#define ATOMIC_OP(op) \
ENTRY(atomic_##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; \
nop; \
2: BACKOFF_SPIN(%o2, %o3, 1b); \
ENDPROC(atomic_##op); \
#define ATOMIC_OP_RETURN(op) \
ENTRY(atomic_##op##_return) /* %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); \
op %g1, %o0, %g1; \
retl; \
sra %g1, 0, %o0; \
2: BACKOFF_SPIN(%o2, %o3, 1b); \
ENDPROC(atomic_##op##_return);
#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op)
ATOMIC_OPS(add)
ATOMIC_OPS(sub)
#undef ATOMIC_OPS
#undef ATOMIC_OP_RETURN
#undef ATOMIC_OP
#define ATOMIC64_OP(op) \
ENTRY(atomic64_##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; \
nop; \
2: BACKOFF_SPIN(%o2, %o3, 1b); \
ENDPROC(atomic64_##op); \
#define ATOMIC64_OP_RETURN(op) \
ENTRY(atomic64_##op##_return) /* %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; \
op %g1, %o0, %o0; \
2: BACKOFF_SPIN(%o2, %o3, 1b); \
ENDPROC(atomic64_##op##_return);
#define ATOMIC64_OPS(op) ATOMIC64_OP(op) ATOMIC64_OP_RETURN(op)
ATOMIC64_OPS(add)
ATOMIC64_OPS(sub)
#undef ATOMIC64_OPS
#undef ATOMIC64_OP_RETURN
#undef ATOMIC64_OP
ENTRY(atomic64_dec_if_positive) /* %o0 = atomic_ptr */
BACKOFF_SETUP(%o2)
1: ldx [%o0], %g1
brlez,pn %g1, 3f
sub %g1, 1, %g7
casx [%o0], %g1, %g7
cmp %g1, %g7
bne,pn %xcc, BACKOFF_LABEL(2f, 1b)
nop
3: retl
sub %g1, 1, %o0
2: BACKOFF_SPIN(%o2, %o3, 1b)
ENDPROC(atomic64_dec_if_positive)