diff options
Diffstat (limited to 'arch/sparc/lib/atomic_64.S')
| -rw-r--r-- | arch/sparc/lib/atomic_64.S | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/arch/sparc/lib/atomic_64.S b/arch/sparc/lib/atomic_64.S index 4d502da3de7..85c233d0a34 100644 --- a/arch/sparc/lib/atomic_64.S +++ b/arch/sparc/lib/atomic_64.S @@ -1,6 +1,6 @@ /* atomic.S: These things are too big to do inline. * - * Copyright (C) 1999, 2007 David S. Miller (davem@davemloft.net) + * Copyright (C) 1999, 2007 2012 David S. Miller (davem@davemloft.net) */ #include <linux/linkage.h> @@ -117,3 +117,17 @@ ENTRY(atomic64_sub_ret) /* %o0 = decrement, %o1 = atomic_ptr */ sub %g1, %o0, %o0 2: BACKOFF_SPIN(%o2, %o3, 1b) ENDPROC(atomic64_sub_ret) + +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) |