From:   Nathan Chancellor <nathan@kernel.org>
Subject: [PATCH 0/3] Allow CONFIG_PPC64_BIG_ENDIAN_ELF_ABI_V2 with ld.lld
 15+
Date:   Wed, 15 Feb 2023 11:41:14 -0700
Message-Id: <20230118-ppc64-elfv2-llvm-v1-0-b9e2ec9da11d@kernel.org>
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To:     mpe@ellerman.id.au
Cc:     npiggin@gmail.com, christophe.leroy@csgroup.eu,
        erhard_f@mailbox.org, nathan@kernel.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
Precedence: bulk

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.

---
Nathan Chancellor (3):
      powerpc/boot: Only use '-mabi=elfv2' with CONFIG_PPC64_BOOT_WRAPPER
      powerpc: Fix use of '-mabi=elfv2' with clang
      powerpc: Allow CONFIG_PPC64_BIG_ENDIAN_ELF_ABI_V2 with ld.lld 15+

 arch/powerpc/Kconfig       | 3 +--
 arch/powerpc/Makefile      | 4 +---
 arch/powerpc/boot/Makefile | 6 +++---
 3 files changed, 5 insertions(+), 8 deletions(-)
---
base-commit: 5dc4c995db9eb45f6373a956eb1f69460e69e6d4
change-id: 20230118-ppc64-elfv2-llvm-39edac67bf0a

Best regards,
-- 
Nathan Chancellor <nathan@kernel.org>