This is a note to let you know that I've just added the patch titled riscv: fix detection of toolchain Zihintpause support to the 6.0-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: riscv-fix-detection-of-toolchain-zihintpause-support.patch and it can be found in the queue-6.0 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit bc9ce3a6f0940c5fa8f9c5007f9d39f27d9939c7 Author: Conor Dooley <conor.dooley@xxxxxxxxxxxxx> Date: Thu Oct 6 18:35:21 2022 +0100 riscv: fix detection of toolchain Zihintpause support [ Upstream commit aae538cd03bc8fc35979653d9180922d146da0ca ] It is not sufficient to check if a toolchain supports a particular extension without checking if the linker supports that extension too. For example, Clang 15 supports Zihintpause but GNU bintutils 2.35.2 does not, leading build errors like so: riscv64-linux-gnu-ld: -march=rv64i2p0_m2p0_a2p0_c2p0_zihintpause2p0: Invalid or unknown z ISA extension: 'zihintpause' Add a TOOLCHAIN_HAS_ZIHINTPAUSE which checks if each of the compiler, assembler and linker support the extension. Replace the ifdef in the vdso with one depending on this new symbol. Fixes: 8eb060e10185 ("arch/riscv: add Zihintpause support") Signed-off-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx> Reviewed-by: Heiko Stuebner <heiko@xxxxxxxxx> Reviewed-by: Nathan Chancellor <nathan@xxxxxxxxxx> Link: https://lore.kernel.org/r/20221006173520.1785507-3-conor@xxxxxxxxxx Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index e646298d2d65..9d5b7fa1b622 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -426,6 +426,13 @@ config RISCV_ISA_ZICBOM If you don't know what to do here, say Y. +config TOOLCHAIN_HAS_ZIHINTPAUSE + bool + default y + depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zihintpause) + depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zihintpause) + depends on LLD_VERSION >= 150000 || LD_VERSION >= 23600 + config FPU bool "FPU support" default y diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile index d1dbbe0fb0f8..e5a608e37f45 100644 --- a/arch/riscv/Makefile +++ b/arch/riscv/Makefile @@ -62,8 +62,7 @@ riscv-march-$(toolchain-need-zicsr-zifencei) := $(riscv-march-y)_zicsr_zifencei riscv-march-$(CONFIG_TOOLCHAIN_HAS_ZICBOM) := $(riscv-march-y)_zicbom # Check if the toolchain supports Zihintpause extension -toolchain-supports-zihintpause := $(call cc-option-yn, -march=$(riscv-march-y)_zihintpause) -riscv-march-$(toolchain-supports-zihintpause) := $(riscv-march-y)_zihintpause +riscv-march-$(CONFIG_TOOLCHAIN_HAS_ZIHINTPAUSE) := $(riscv-march-y)_zihintpause KBUILD_CFLAGS += -march=$(subst fd,,$(riscv-march-y)) KBUILD_AFLAGS += -march=$(riscv-march-y) diff --git a/arch/riscv/include/asm/vdso/processor.h b/arch/riscv/include/asm/vdso/processor.h index 1e4f8b4aef79..fa70cfe507aa 100644 --- a/arch/riscv/include/asm/vdso/processor.h +++ b/arch/riscv/include/asm/vdso/processor.h @@ -21,7 +21,7 @@ static inline void cpu_relax(void) * Reduce instruction retirement. * This assumes the PC changes. */ -#ifdef __riscv_zihintpause +#ifdef CONFIG_TOOLCHAIN_HAS_ZIHINTPAUSE __asm__ __volatile__ ("pause"); #else /* Encoding of the pause instruction */