From: WANG Xuerui <git@xxxxxxxxxx> Hi, It's been a long time since the LoongArch port was upstreamed to LLVM, and there seems to be evidence that Linux was successfully built with Clang inside Loongson roughly around that time; however, a lot has changed since then, and the Linux/LoongArch codebase now makes use of more novel features that necessitate further work. (The enablement work is tracked at [1].) With this patch series and a patched LLVM/LLD ([2] for llvm-objcopy, and [3] for LLD), a working kernel can be built with `make LLVM=1`; although currently support for CONFIG_RELOCATABLE and CONFIG_MODULE is still TODO, we've decided to post the series early to hopefully reduce the rebase burden. The series contains several useful cleanups anyway. Regarding how to merge this: because only Patch 8 is outside arch/loongarch, I'd prefer the series to get merged through Huacai's tree. The series applies cleanly on top of next-20230622. Thanks go to the ClangBuiltLinux team, and LoongArch toolchain maintainers from Loongson and the community alike; without your help this would come much later, if at all (my free time has been steadily dwindling this year already). Your comments are welcome! [1]: https://github.com/ClangBuiltLinux/linux/issues/1787 [2]: https://reviews.llvm.org/D153609 [3]: https://reviews.llvm.org/D138135 WANG Rui (2): LoongArch: Calculate various sizes in the linker script LoongArch: extable: Also recognize ABI names of registers WANG Xuerui (7): LoongArch: Prepare for assemblers with proper FCSR bank support LoongArch: Make {read,write}_fcsr compatible with LLVM/Clang LoongArch: Make the CPUCFG and CSR ops simple aliases of compiler built-ins LoongArch: Simplify the invtlb wrappers LoongArch: Tweak CFLAGS for Clang compatibility Makefile: Add loongarch target flag for Clang compilation LoongArch: Mark Clang LTO as working arch/loongarch/Kconfig | 5 ++ arch/loongarch/Makefile | 14 ++++- arch/loongarch/include/asm/fpregdef.h | 7 +++ arch/loongarch/include/asm/gpr-num.h | 30 ++++++++++ arch/loongarch/include/asm/loongarch.h | 82 ++++++++------------------ arch/loongarch/include/asm/tlb.h | 45 +++++--------- arch/loongarch/kernel/efi-header.S | 6 +- arch/loongarch/kernel/head.S | 8 +-- arch/loongarch/kernel/traps.c | 2 +- arch/loongarch/kernel/vmlinux.lds.S | 7 +++ arch/loongarch/lib/dump_tlb.c | 6 +- arch/loongarch/mm/tlb.c | 10 ++-- arch/loongarch/vdso/Makefile | 6 +- scripts/Makefile.clang | 1 + 14 files changed, 122 insertions(+), 107 deletions(-) -- 2.40.0
