From aae538cd03bc8fc35979653d9180922d146da0ca Mon Sep 17 00:00:00 2001 From: Conor Dooley Date: Thu, 6 Oct 2022 18:35:21 +0100 Subject: [PATCH] riscv: fix detection of toolchain Zihintpause support 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 Reviewed-by: Heiko Stuebner Reviewed-by: Nathan Chancellor Link: https://lore.kernel.org/r/20221006173520.1785507-3-conor@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/Kconfig | 7 +++++++ arch/riscv/Makefile | 3 +-- arch/riscv/include/asm/vdso/processor.h | 2 +- 3 files changed, 9 insertions(+), 3 deletions(-) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 4c6a09f..d984f61 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -425,6 +425,13 @@ 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 || $(cc-option,-mabi=ilp32 -march=rv32ima_zihintpause) + depends on LLD_VERSION >= 150000 || LD_VERSION >= 23600 + config FPU bool "FPU support" default y diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile index 3607d38..6651517 100644 --- a/arch/riscv/Makefile +++ b/arch/riscv/Makefile @@ -60,8 +60,7 @@ riscv-march-$(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 1e4f8b4..fa70cfe 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 */ -- 2.7.4