From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1B665197 for ; Fri, 24 Feb 2023 16:37:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5477EC433D2; Fri, 24 Feb 2023 16:37:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1677256650; bh=5KoQTxArulQ7bM11DTjGz3jpBGFaiF67rqpLvKCWpdE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QT3lnmzoBM8WBMSOtsmWwtV/MjjuR4LlWs7fV+LRoEEcojnIAajocqIaN8QTd5U95 BCLXCInp+XtxHHlUU7WCazrUcZpRJKgJRT15TE+LX2GT9gYxQt79WXdnthPc0LfIzr QzISB4RSDm/THC8QT+99L8duDhQdD23jvG18aOPLTPEtduUF0xfYiQAA9UXTRNvFUM Pc0j+FCmpDuQRgP5LJKjtEerJwMA3sZjtexUrf9EL+kw78XmTg48XcMX8tosBJ38xl zfX/IJVQhrDtZtCkINutpNf9yGz10pPEOorK7POER2Pn6eYQS5biM3g4g36Y7UsEie XdOLx7qvA/PzA== Date: Fri, 24 Feb 2023 09:37:28 -0700 From: Nathan Chancellor To: Conor Dooley Cc: palmer@dabbelt.com, Conor Dooley , naresh.kamboju@linaro.org, linux-riscv@lists.infradead.org, llvm@lists.linux.dev Subject: Re: [PATCH v1 1/2] RISC-V: move zicsr/zifencei spec version check to Kconfig Message-ID: References: <20230223220546.52879-1-conor@kernel.org> <20230223220546.52879-2-conor@kernel.org> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230223220546.52879-2-conor@kernel.org> On Thu, Feb 23, 2023 at 10:05:45PM +0000, Conor Dooley wrote: > From: Conor Dooley > > Checking whether binutils defaults to using a version of the spec > requiring zicsr/zifencei being done in our Makefile is functionally > sufficient at present, but makes it harder to tell after the fact > which extensions are enabled. > By moving it to Kconfig, it's easy to tell from standard build artifacts > what has been done & the road is paved for dealing with this differently > for both binutils and LLVM. > > Signed-off-by: Conor Dooley Reviewed-by: Nathan Chancellor > --- > arch/riscv/Kconfig | 10 ++++++++++ > arch/riscv/Makefile | 5 +---- > 2 files changed, 11 insertions(+), 4 deletions(-) > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index cebf0c5f8824..4eb0ef8314b3 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -288,6 +288,16 @@ config ARCH_RV64I > > endchoice > > +config TOOLCHAIN_NEEDS_SPEC_20191213 This symbol's name is a little confusing to me, how does the toolchain need spec version 20191213. Maybe 'SPEC_20191213' should be something like 'EXPLICIT_ZICSR_ZIFENCEI'? Otherwise, maybe it should be something like 'TOOLCHAIN_HAS_DEFAULT_SPEC_20191213'? Sorry for the bikeshed but I think most Kconfig symbols should be self describing. > + bool > + default y > + depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zicsr_zifencei) > + depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zicsr_zifencei) > + help > + Newer binutils versions default to ISA spec version 20191213 which > + moves some instructions from the I extension to the Zicsr and Zifencei > + extensions. > + > # We must be able to map all physical memory into the kernel, but the compiler > # is still a bit more efficient when generating code if it's setup in a manner > # such that it can only map 2GiB of memory. > diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile > index 12d91b0a73d8..7e1267b0e73f 100644 > --- a/arch/riscv/Makefile > +++ b/arch/riscv/Makefile > @@ -53,10 +53,7 @@ riscv-march-$(CONFIG_ARCH_RV64I) := rv64ima > riscv-march-$(CONFIG_FPU) := $(riscv-march-y)fd > riscv-march-$(CONFIG_RISCV_ISA_C) := $(riscv-march-y)c > > -# Newer binutils versions default to ISA spec version 20191213 which moves some > -# instructions from the I extension to the Zicsr and Zifencei extensions. > -toolchain-need-zicsr-zifencei := $(call cc-option-yn, -march=$(riscv-march-y)_zicsr_zifencei) > -riscv-march-$(toolchain-need-zicsr-zifencei) := $(riscv-march-y)_zicsr_zifencei > +riscv-march-$(CONFIG_TOOLCHAIN_NEEDS_SPEC_20191213) := $(riscv-march-y)_zicsr_zifencei > > # Check if the toolchain supports Zicbom extension > riscv-march-$(CONFIG_TOOLCHAIN_HAS_ZICBOM) := $(riscv-march-y)_zicbom > -- > 2.39.1 >