From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from gloria.sntech.de (gloria.sntech.de [185.11.138.130]) (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 86B034690 for ; Thu, 6 Oct 2022 18:18:24 +0000 (UTC) Received: from ip5b412258.dynamic.kabel-deutschland.de ([91.65.34.88] helo=diego.localnet) by gloria.sntech.de with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1ogV3x-0001hI-UG; Thu, 06 Oct 2022 19:53:37 +0200 From: Heiko =?ISO-8859-1?Q?St=FCbner?= To: Palmer Dabbelt , Nathan Chancellor , Nick Desaulniers , Conor Dooley Cc: Tom Rix , Conor Dooley , Dao Lu , Guo Ren , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, Kevin Hilman Subject: Re: [PATCH 1/2] riscv: fix detection of toolchain Zicbom support Date: Thu, 06 Oct 2022 19:53:36 +0200 Message-ID: <14737143.tv2OnDr8pf@diego> In-Reply-To: <20221006173520.1785507-2-conor@kernel.org> References: <20221006173520.1785507-1-conor@kernel.org> <20221006173520.1785507-2-conor@kernel.org> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Hi Conor, Am Donnerstag, 6. Oktober 2022, 19:35:20 CEST schrieb Conor Dooley: > From: Conor Dooley > > 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 Zicbom but GNU bintutils 2.35.2 does > not, leading build errors like so: > > riscv64-linux-gnu-ld: -march=rv64i2p0_m2p0_a2p0_c2p0_zicbom1p0_zihintpause2p0: Invalid or unknown z ISA extension: 'zicbom' > > Convert CC_HAS_ZICBOM to TOOLCHAIN_HAS_ZICBOM & check if the linker > also supports Zicbom. > > Reported-by: Kevin Hilman > Link: https://github.com/ClangBuiltLinux/linux/issues/1714 > Link: https://storage.kernelci.org/next/master/next-20220920/riscv/defconfig+CONFIG_EFI=n/clang-16/logs/kernel.log > Fixes: 1631ba1259d6 ("riscv: Add support for non-coherent devices using zicbom extension") > Signed-off-by: Conor Dooley > --- > arch/riscv/Kconfig | 10 ++++++---- > arch/riscv/Makefile | 3 +-- > 2 files changed, 7 insertions(+), 6 deletions(-) > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index d557cc50295d..6da36553158b 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -401,14 +401,16 @@ config RISCV_ISA_SVPBMT > > If you don't know what to do here, say Y. > > -config CC_HAS_ZICBOM > +config TOOLCHAIN_HAS_ZICBOM > bool > - default y if 64BIT && $(cc-option,-mabi=lp64 -march=rv64ima_zicbom) > - default y if 32BIT && $(cc-option,-mabi=ilp32 -march=rv32ima_zicbom) > + default y > + depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zicbom) > + depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zicbom) > + depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 I did needed to look quite closely at the cc-option-voodoo, but it really seems to work out as expected :-) I can't say much to the specific L(L)D_VERSION values but the change itself looks good, so Reviewed-by: Heiko Stuebner > > config RISCV_ISA_ZICBOM > bool "Zicbom extension support for non-coherent DMA operation" > - depends on CC_HAS_ZICBOM > + depends on TOOLCHAIN_HAS_ZICBOM > depends on !XIP_KERNEL && MMU > select RISCV_DMA_NONCOHERENT > select RISCV_ALTERNATIVE > diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile > index 3fa8ef336822..3607d38edb4f 100644 > --- a/arch/riscv/Makefile > +++ b/arch/riscv/Makefile > @@ -57,8 +57,7 @@ toolchain-need-zicsr-zifencei := $(call cc-option-yn, -march=$(riscv-march-y)_zi > riscv-march-$(toolchain-need-zicsr-zifencei) := $(riscv-march-y)_zicsr_zifencei > > # Check if the toolchain supports Zicbom extension > -toolchain-supports-zicbom := $(call cc-option-yn, -march=$(riscv-march-y)_zicbom) > -riscv-march-$(toolchain-supports-zicbom) := $(riscv-march-y)_zicbom > +riscv-march-$(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) >