Re: [PATCH 9/24] make atomic_read() behave consistently on ia64

From: Andreas Schwab
Date: Fri Aug 10 2007 - 17:43:30 EST


"Luck, Tony" <tony.luck@xxxxxxxxx> writes:

>> That's distressing. I'm about to resubmit with a volatile cast in
>> atomic_set as well, since people expect that behavior and I've been
>> shown a legitimate case where it could matter. Does the assembly look
>> right with that cast in atomic_set() as well?
>
> No. With the casts to volatile in atomic_set and atomic64_set I
> still see places where ld8 is changed to ld4 + sign-extend.

Use atomic64_read to read an atomic64_t.

Signed-off-by: Andreas Schwab <schwab@xxxxxxx>

diff --git a/include/asm-ia64/atomic.h b/include/asm-ia64/atomic.h
index 1fc3b83..50c2b83 100644
--- a/include/asm-ia64/atomic.h
+++ b/include/asm-ia64/atomic.h
@@ -55,7 +55,7 @@ ia64_atomic64_add (__s64 i, atomic64_t *v)

do {
CMPXCHG_BUGCHECK(v);
- old = atomic_read(v);
+ old = atomic64_read(v);
new = old + i;
} while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic64_t)) != old);
return new;
@@ -83,7 +83,7 @@ ia64_atomic64_sub (__s64 i, atomic64_t *v)

do {
CMPXCHG_BUGCHECK(v);
- old = atomic_read(v);
+ old = atomic64_read(v);
new = old - i;
} while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic64_t)) != old);
return new;

Andreas.

--
Andreas Schwab, SuSE Labs, schwab@xxxxxxx
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
PGP key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5
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