RFR(M): 8154736: enhancement of cmpxchg and copy_to_survivor for ppc64

[John Paul Adrian Glaubitz]

Hi Gustavo!

On 04/24/2018 05:54 PM, Gustavo Romero wrote:
>> Quick question: Does this pose any assumptions on the instruction set baseline
>> on ppc64? I haven't build-tested this yet, but I want to avoid it doesn't break
>> on POWER5, for example, which is used in Debian's big-endian ppc64 port.
> 
> Yes, it does. But POWER5 and above are ok. Lightweight sync (lwsync) was
> introduced with Power ISA v2.03 which, by its turn, maps to POWER5.

We are primarily interested in PPC970 and compatible which - according
to Wikipedia - is compliant with POWER ISA 2.03:

> https://en.wikipedia.org/wiki/Power_Architecture#Power_ISA_v.2.03

It's sometimes a bit confusing to differentiate all the different
POWER ISAs because there are so many. That's why I usually ask
in such cases.

> Thanks for taking care of Power + Debian :-)

You're welcome. Debian has both a big-endian (POWER5/970) and little-endian
(POWER8) ppc64 port as well as powerpc (32-bit) and powerpcspe (e500v2)
ports, so PowerPC is quite popular within Debian ;).

Thanks,
Adrian

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer - glaubitz at debian.org
`. `'   Freie Universitaet Berlin - glaubitz at physik.fu-berlin.de
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