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Date:   Sun, 13 Nov 2022 19:20:17 +0100
From:   Heiko Carstens <hca@linux.ibm.com>
To:     Heiko Carstens <hca@linux.ibm.com>
Cc:     Janis Schoetterl-Glausch <scgl@linux.ibm.com>,
        Christian Borntraeger <borntraeger@linux.ibm.com>,
        Janosch Frank <frankja@linux.ibm.com>,
        Claudio Imbrenda <imbrenda@linux.ibm.com>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Alexander Gordeev <agordeev@linux.ibm.com>,
        David Hildenbrand <david@redhat.com>,
        Jonathan Corbet <corbet@lwn.net>, kvm@vger.kernel.org,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-kselftest@vger.kernel.org, linux-s390@vger.kernel.org,
        Paolo Bonzini <pbonzini@redhat.com>,
        Shuah Khan <shuah@kernel.org>,
        Sven Schnelle <svens@linux.ibm.com>
Subject: Re: [PATCH 5/5] s390/uaccess: add cmpxchg_user_key()
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On Thu, Nov 10, 2022 at 12:32:06PM +0100, Heiko Carstens wrote:
> > That's why I asked about cmpxchg.h. If you don't want non-cosmetic changes to the existing
> > cmpxchg function and consistency of the new key checked function, then obviously the loop
> > condition needs to be the same.
> 
> Such a change is fine of course, even though compare-and-swap for one and
> two byte patterns don't really matter. I would appreciate if you could send
> one or two patches on-top of this series which adds the improved logic to
> (now) both variants.
> 
> And, since the question will come up anyway: as soon as we agreed on a
> complete patch series, I think we should go for a features branch on s390's
> kernel.org tree which would contain the first five patches sent by me plus
> potential addon patches provided by you.
> This tree can then be pulled in by the kvms390 tree where your kvm specific
> patches can then be applied on top.

FWIW, pushed a non-stable work-in-progress branch to
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git wip/cmpxchg_user_key

This includes also an updated patch, which fixes the missing shift of
the access key.