diff options
| author | Ralf Baechle <ralf@linux-mips.org> | 2000-08-28 22:00:09 +0000 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2000-08-28 22:00:09 +0000 |
| commit | 1a1d77dd589de5a567fa95e36aa6999c704ceca4 (patch) | |
| tree | 141e31f89f18b9fe0831f31852e0435ceaccafc5 /arch/sparc64/lib/dec_and_lock.S | |
| parent | fb9c690a18b3d66925a65b17441c37fa14d4370b (diff) | |
Merge with 2.4.0-test7.
Diffstat (limited to 'arch/sparc64/lib/dec_and_lock.S')
| -rw-r--r-- | arch/sparc64/lib/dec_and_lock.S | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/arch/sparc64/lib/dec_and_lock.S b/arch/sparc64/lib/dec_and_lock.S index 75dfdbfcf..2a59b2788 100644 --- a/arch/sparc64/lib/dec_and_lock.S +++ b/arch/sparc64/lib/dec_and_lock.S @@ -1,4 +1,4 @@ -/* $Id: dec_and_lock.S,v 1.1 2000/07/10 20:57:34 davem Exp $ +/* $Id: dec_and_lock.S,v 1.2 2000/08/13 18:24:12 davem Exp $ * dec_and_lock.S: Sparc64 version of "atomic_dec_and_lock()" * using cas and ldstub instructions. * @@ -17,12 +17,10 @@ * TMP = *(MEM); * *(MEM) = REG2; * REG2 = TMP; - * } + * } else + * REG2 = *(MEM); * END_ATOMIC(); * } - * - * All non-contention cases are handled in 2 I-cache - * lines which is 1 L2 cache line. */ .globl atomic_dec_and_lock @@ -42,20 +40,24 @@ to_zero:ldstub [%o1], %g3 brnz,pn %g3, spin_on_lock membar #StoreLoad | #StoreStore loop2: cas [%o0], %g5, %g7 /* ASSERT(g7 == 0) */ - brnz,pt %g7, out - mov 1, %g1 + nop + cmp %g5, %g7 + be,pt %icc, out + mov 1, %g1 lduw [%o0], %g5 subcc %g5, 1, %g7 be,pn %icc, loop2 nop membar #StoreStore | #LoadStore stb %g0, [%o1] + b,pt %xcc, nzero nop - spin_on_lock: ldub [%o1], %g3 brnz,pt %g3, spin_on_lock membar #LoadLoad - b,a,pt %xcc, to_zero + ba,pt %xcc, to_zero + nop + nop |