On 21.02.2009 21:49, Stefan Reinauer wrote: > On 21.02.2009 21:39 Uhr, Carl-Daniel Hailfinger wrote: > >> On 21.02.2009 21:31, ron minnich wrote: >> >> >>> Also I guess it's time to make printk smp-safe. >>> >>> >>> >> Cool! The big problem here is that you need locking and for that you >> need something which is shared between CPUs. IIRC this means storing the >> lock in CAR is a no-go on some processors. >> >> > > Yes. the locking mechanisms are all there but can not be used. (or they > were, at some point) > > The simplest way would be to use a scratchpad register of the chipset as > a semaphore. That's rather safe but unless on PCIe it can not be done > atomic. >
What about scratchpad registers in the CPU which are guaranteed to be cache-coherent across multiple cores and processors? Regards, Carl-Daniel -- http://www.hailfinger.org/ -- coreboot mailing list: [email protected] http://www.coreboot.org/mailman/listinfo/coreboot
