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| author |   David S. Miller <davem@davemloft.net> | 2012-11-09 19:37:59 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-11-09 19:37:59 -0800 |
| commit | 193d2aadc0ff5c687f6f0d5ef1d38c86ab511a14 (patch) | |
| tree | 294286e259a08c977e3e71819b2c1d763b13312f /arch/sparc/lib/atomic_64.S | |
| parent | of/address: sparc: Declare of_address_to_resource() as an extern function for sparc again (diff) | |
| download | linux-dev-193d2aadc0ff5c687f6f0d5ef1d38c86ab511a14.tar.xz linux-dev-193d2aadc0ff5c687f6f0d5ef1d38c86ab511a14.zip | |
sparc: Support atomic64_dec_if_positive properly.
Sparc32 already supported it, as a consequence of using the
generic atomic64 implementation. And the sparc64 implementation
is rather trivial.
This allows us to set ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE for all
of sparc, and avoid the annoying warning from lib/atomic64_test.c
Signed-off-by: David S. Miller <davem@davemloft.net>
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 4d502da3de78..85c233d0a340 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) |