Re: [PATCH v3 06/11] selftests: Fix arm64 IO barriers to match kernel
From: Nathan Chancellor <nathan@kernel.org>
Date: 2026-07-16 23:22:17
Also in:
kvm, linux-kselftest, linux-patches, linux-rdma, llvm
On Thu, Jul 16, 2026 at 02:03:22PM -0300, Jason Gunthorpe wrote:
The tools/include readl/writel MMIO accessors on arm64 use inner-shareable barriers (dmb ish) while the kernel uses outer-shareable (dmb osh). Fix them to match. Add __io_bw() and __io_ar() definitions matching the kernel's arch/arm64/include/asm/io.h, including the dummy control dependency in __io_ar() that orders MMIO reads against all subsequent instructions. Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
...
quoted hunk ↗ jump to hunk
diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk index f02cc8a2e4ae32..fdd22df9174b88 100644 --- a/tools/testing/selftests/lib.mk +++ b/tools/testing/selftests/lib.mk@@ -5,9 +5,14 @@ ifneq ($(filter %/,$(LLVM)),) LLVM_PREFIX := $(LLVM) else ifneq ($(filter -%,$(LLVM)),) LLVM_SUFFIX := $(LLVM) +else ifneq ($(LLVM),1) +$(error Invalid value for LLVM, see Documentation/kbuild/llvm.rst) endif CLANG := $(LLVM_PREFIX)clang$(LLVM_SUFFIX) +LD := $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX) +# Selftests link through $(CC), so point clang at the LLVM linker. +LDFLAGS += --ld-path=$(LD) CLANG_TARGET_FLAGS_arm := arm-linux-gnueabi CLANG_TARGET_FLAGS_arm64 := aarch64-linux-gnu
Was this hunk intended to be included in this change? It is not mentioned anywhere. I assume this is the only reason that the LLVM folks were CC'd on this series. -- Cheers, Nathan