Date:   Mon, 20 Feb 2023 08:51:06 -0700
From:   Nathan Chancellor <nathan@kernel.org>
To:     Michael Ellerman <mpe@ellerman.id.au>
Cc:     npiggin@gmail.com, christophe.leroy@csgroup.eu,
        erhard_f@mailbox.org, ndesaulniers@google.com, trix@redhat.com,
        linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
        llvm@lists.linux.dev, patches@lists.linux.dev
Subject: Re: [PATCH 0/3] Allow CONFIG_PPC64_BIG_ENDIAN_ELF_ABI_V2 with ld.lld
 15+
Message-ID: <Y/OW6mRi3qDpVQkc@dev-arch.thelio-3990X>
References: <20230118-ppc64-elfv2-llvm-v1-0-b9e2ec9da11d@kernel.org>
 <87wn4cyifp.fsf@mpe.ellerman.id.au>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <87wn4cyifp.fsf@mpe.ellerman.id.au>
Precedence: bulk

On Mon, Feb 20, 2023 at 05:11:54PM +1100, Michael Ellerman wrote:
> Nathan Chancellor <nathan@kernel.org> writes:
> > Currently, CONFIG_PPC64_BIG_ENDIAN_ELF_ABI_V2 is not selectable with
> > ld.lld because of an explicit dependency on GNU ld, due to lack of
> > testing with LLVM.
> >
> > Erhard was kind enough to test this option on his hardware with LLVM 15,
> > which ran without any issues. This should not be too surprising, as
> > ld.lld does not have support for the ELFv1 ABI, only ELFv2, so it should
> > have decent support. With this series, big endian kernels can be built
> > with LLVM=1.
> >
> > This has seen our basic set of powerpc configurations with clang-15,
> > clang-16, and clang-17 but I will never be opposed to more testing :)
> >
> > The first two patches fix a couple of issues I noticed while build
> > testing and the final patch actually allows the option to be selected.
> 
> Thanks for this.
> 
> I thought about applying this last week but decided not to. I'll plan to
> pick it up for 6.4.

No worries, I sent this much later in the development cycle than I had
initially intended, so I figured that 6.3 was a long shot anyways. Plus
more soak time is never a bad thing :)

Thanks for taking the initial look, cheers!
Nathan