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(unknown [111.197.209.91]) by APP-03 (Coremail) with SMTP id rQCowACnrcW2zcdkoZmtDw--.21850S2; Mon, 31 Jul 2023 23:05:27 +0800 (CST) From: Mingzheng Xing To: Conor Dooley , Paul Walmsley , Palmer Dabbelt , Albert Ou , Nathan Chancellor , Nick Desaulniers , Tom Rix Cc: Bin Meng , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, stable@vger.kernel.org, Guo Ren , Mingzheng Xing Subject: [PATCH] riscv: Handle zicsr/zifencei issue between gcc and binutils Date: Mon, 31 Jul 2023 23:05:11 +0800 Message-Id: <20230731150511.38140-1-xingmingzheng@iscas.ac.cn> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230731095534.22842-1-xingmingzheng@iscas.ac.cn> References: <20230731095534.22842-1-xingmingzheng@iscas.ac.cn> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: rQCowACnrcW2zcdkoZmtDw--.21850S2 X-Coremail-Antispam: 1UD129KBjvJXoWxuw4UGFyrury5GFWfKF1rJFb_yoW7ZFyUpr W3CFyDCr4Fga18Gr1fAw1UWw1Yyrs3J3ySgFW0kw1UGrnxJFyDKr9Yyw17XFyUZFn2grZ0 vw1S9anYg3ZrAaDanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUv014x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26r1j6r1xM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4j 6F4UM28EF7xvwVC2z280aVAFwI0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_Cr 1j6rxdM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj 6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr 0_Gr1lF7xvr2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7M4IIrI8v6xkF7I0E 8cxan2IY04v7MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I 8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUtVW8 ZwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x 0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_ Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7VUb XdbUUUUUU== X-Originating-IP: [111.197.209.91] X-CM-SenderInfo: 50lqwzhlqj6xxhqjqxpvfd2hldfou0/1tbiBwgJCmTHvEwkBQAAs+ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Binutils-2.38 and GCC-12.1.0 bumped[0][1] the default ISA spec to the newer 20191213 version which moves some instructions from the I extension to the Zicsr and Zifencei extensions. So if one of the binutils and GCC exceeds that version, we should explicitly specifying Zicsr and Zifencei via -march to cope with the new changes. but this only occurs when binutils >=3D 2.36 and GCC >=3D 11.1.0. It's a different story when binutils < 2.36. binutils-2.36 supports the Zifencei extension[2] and splits Zifencei and Zicsr from I[3]. GCC-11.1.0 is particular[4] because it add support Zicsr and Zifencei extension for -march. binutils-2.35 does not support the Zifencei extension, and does not need to specify Zicsr and Zifencei when working with GCC >=3D 12.1.0. To make our lives easier, let's relax the check to binutils >=3D 2.36 in CONFIG_TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI. For the other two cases, where clang < 17 or GCC < 11.1.0, we will deal with them in CONFIG_TOOLCHAIN_NEEDS_OLD_ISA_SPEC. For more information, please refer to: commit 6df2a016c0c8 ("riscv: fix build with binutils 2.38") commit e89c2e815e76 ("riscv: Handle zicsr/zifencei issues between clang and= binutils") Link: https://sourceware.org/git/?p=3Dbinutils-gdb.git;a=3Dcommit;h=3Daed44= 286efa8ae8717a77d94b51ac3614e2ca6dc [0] Link: https://gcc.gnu.org/git/?p=3Dgcc.git;a=3Dcommit;h=3D98416dbb0a62579d4= a7a4a76bab51b5b52fec2cd [1] Link: https://sourceware.org/git/?p=3Dbinutils-gdb.git;a=3Dcommit;h=3D5a1b3= 1e1e1cee6e9f1c92abff59cdcfff0dddf30 [2] Link: https://sourceware.org/git/?p=3Dbinutils-gdb.git;a=3Dcommit;h=3D729a5= 3530e86972d1143553a415db34e6e01d5d2 [3] Link: https://gcc.gnu.org/git/?p=3Dgcc.git;a=3Dcommit;h=3Db03be74bad08c382d= a47e048007a78fa3fb4ef49 [4] Link: https://lore.kernel.org/all/20230308220842.1231003-1-conor@kernel.org Link: https://lore.kernel.org/all/20230223220546.52879-1-conor@kernel.org Cc: Signed-off-by: Mingzheng Xing Acked-by: Guo Ren Reviewed-by: Conor Dooley --- arch/riscv/Kconfig | 32 +++++++++++++++----------- arch/riscv/kernel/compat_vdso/Makefile | 8 ++++++- 2 files changed, 26 insertions(+), 14 deletions(-) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 4c07b9189c86..10e7a7ad175a 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -570,24 +570,30 @@ config TOOLCHAIN_HAS_ZIHINTPAUSE config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI def_bool y # https://sourceware.org/git/?p=3Dbinutils-gdb.git;a=3Dcommit;h=3Daed4428= 6efa8ae8717a77d94b51ac3614e2ca6dc - depends on AS_IS_GNU && AS_VERSION >=3D 23800 - help - Newer binutils versions default to ISA spec version 20191213 which - moves some instructions from the I extension to the Zicsr and Zifencei - extensions. + # https://gcc.gnu.org/git/?p=3Dgcc.git;a=3Dcommit;h=3D98416dbb0a62579d4a7= a4a76bab51b5b52fec2cd + depends on AS_IS_GNU && AS_VERSION >=3D 23600 + help + Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer + 20191213 version, which moves some instructions from the I extension to + the Zicsr and Zifencei extensions. This requires explicitly specifying + Zicsr and Zifencei when binutils >=3D 2.38 or GCC >=3D 12.1.0. Zicsr + and Zifencei are supported in binutils from version 2.36 onwards. + To make life easier, and avoid forcing toolchains that default to a + newer ISA spec to version 2.2, relax the check to binutils >=3D 2.36. + For clang < 17 or GCC < 11.1.0, for which this is not possible, this is + dealt with in CONFIG_TOOLCHAIN_NEEDS_OLD_ISA_SPEC. =20 config TOOLCHAIN_NEEDS_OLD_ISA_SPEC def_bool y depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI # https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d449= 8694e15bf8a16 - depends on CC_IS_CLANG && CLANG_VERSION < 170000 - help - Certain versions of clang do not support zicsr and zifencei via -march - but newer versions of binutils require it for the reasons noted in the - help text of CONFIG_TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI. This - option causes an older ISA spec compatible with these older versions - of clang to be passed to GAS, which has the same result as passing zicsr - and zifencei to -march. + # https://gcc.gnu.org/git/?p=3Dgcc.git;a=3Dcommit;h=3Db03be74bad08c382da4= 7e048007a78fa3fb4ef49 + depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_V= ERSION < 110100) + help + Certain versions of clang and GCC do not support zicsr and zifencei via + -march. This option causes an older ISA spec compatible with these older + versions of clang and GCC to be passed to GAS, which has the same result + as passing zicsr and zifencei to -march. =20 config FPU bool "FPU support" diff --git a/arch/riscv/kernel/compat_vdso/Makefile b/arch/riscv/kernel/com= pat_vdso/Makefile index 189345773e7e..b86e5e2c3aea 100644 --- a/arch/riscv/kernel/compat_vdso/Makefile +++ b/arch/riscv/kernel/compat_vdso/Makefile @@ -11,7 +11,13 @@ compat_vdso-syms +=3D flush_icache COMPAT_CC :=3D $(CC) COMPAT_LD :=3D $(LD) =20 -COMPAT_CC_FLAGS :=3D -march=3Drv32g -mabi=3Dilp32 +# binutils 2.35 does not support the zifencei extension, but in the ISA +# spec 20191213, G stands for IMAFD_ZICSR_ZIFENCEI. +ifdef CONFIG_TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI + COMPAT_CC_FLAGS :=3D -march=3Drv32g -mabi=3Dilp32 +else + COMPAT_CC_FLAGS :=3D -march=3Drv32imafd -mabi=3Dilp32 +endif COMPAT_LD_FLAGS :=3D -melf32lriscv =20 # Disable attributes, as they're useless and break the build. --=20 2.34.1