[coreboot] LOCK prefix

[Patrick Georgi]

Am 2014-12-16 03:54, schrieb ron minnich:
> Notwithstanding the merits of the idea, does anyone know if this is
> doable or I am just misremembering?
Since even LOCK REP ... is not allowed, I think you're misremembering.
LOCK provides atomicity guarantees for the single instruction it covers, 
nothing else.

What's typically used in situations like your example is cmpxchg: load 
the value, copy it, modify, then atomically exchange ram and register 
content. compare exchanged value with copy to make sure there was no 
interference, otherwise restart.


Patrick