Opteron Rev E has a bug ... a locked instruction doesn't act as a read-acquire barrier

From: Arkadiusz Miskiewicz
Date: Sun Aug 03 2008 - 05:06:31 EST



" // Opteron Rev E has a bug in which on very rare occasions a locked
// instruction doesn't act as a read-acquire barrier if followed by a
// non-locked read-modify-write instruction. Rev F has this bug in
// pre-release versions, but not in versions released to customers,
// so we test only for Rev E, which is family 15, model 32..63 inclusive.
if (strcmp(vendor, "AuthenticAMD") == 0 && // AMD
family == 15 &&
32 <= model && model <= 63) {
AtomicOps_Internalx86CPUFeatures.has_amd_lock_mb_bug = true;
} else {
AtomicOps_Internalx86CPUFeatures.has_amd_lock_mb_bug = false;

does kernel have quirk/workaround for this? I'm looking at arch/x86/kernel/cpu
but I don't see workaround related to this (possibly I'm overlooking).

Arkadiusz MiÅkiewicz PLD/Linux Team
arekm / maven.pl http://ftp.pld-linux.org/
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/