From nobody Mon Feb 9 19:38:08 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 5981D28B7CE for ; Wed, 7 May 2025 15:47:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746632837; cv=none; b=o2zDIm9+UHP0eELhCwkjpmDRk6LA0y2cabYr48KJV9g4KICAA9dsfTU3xbR4pDW7rq6BZYE9Q02df7ltu4i747Vq05SLRkxAGzenwJTU/zVPibuTytLI7jjOXZPMrSCJyI8c1C13JjsH3e/BWPUu1SI10efXJUifZPE5vy5ED5M= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746632837; c=relaxed/simple; bh=HHW/VRW/mGVkdrpdo99wEo16Fvla27rU2A19JxzcK3M=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=s/FTIvEkC0cNSyesUVVV7U26lHtSNUiStLT574DLZG1cz/7+Cvpw6AYjSti3U4+2Fd+yoDcSIGYaMsdztBx2Y+ly23z3IfAUwxE3iuS7162fP9OEzvzteAx7Kdb/CQ9Xyt9fyKnE2qc58PLirm5fv9Wu0Ggv1pU2PG+6seTQ/ws= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C7901204C; Wed, 7 May 2025 08:47:05 -0700 (PDT) Received: from e129823.cambridge.arm.com (e129823.arm.com [10.1.197.6]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 4802C3F58B; Wed, 7 May 2025 08:47:12 -0700 (PDT) From: Yeoreum Yun To: catalin.marinas@arm.com, pcc@google.com, will@kernel.org, broonie@kernel.org, anshuman.khandual@arm.com, joey.gouly@arm.com, maz@kernel.org, oliver.upton@linux.dev, frederic@kernel.org, james.morse@arm.com, hardevsinh.palaniya@siliconsignals.io, huangxiaojia2@huawei.com, mark.rutland@arm.com, samuel.holland@sifive.com, palmer@rivosinc.com, charlie@rivosinc.com, thiago.bauermann@linaro.org, bgray@linux.ibm.com, tglx@linutronix.de, puranjay@kernel.org, david@redhat.com, yang@os.amperecomputing.com, mbenes@suse.cz, joel.granados@kernel.org Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Yeoreum Yun Subject: [PATCH v4 4/7] arm64/hwcaps: add MTE_STORE_ONLY hwcaps Date: Wed, 7 May 2025 16:46:51 +0100 Message-Id: <20250507154654.1937588-5-yeoreum.yun@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250507154654.1937588-1-yeoreum.yun@arm.com> References: <20250507154654.1937588-1-yeoreum.yun@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Since ARMv8.9, FEAT_MTE_STORE_ONLY can be used to restrict raise of tag check fault on store operation only. add MTE_STORE_ONLY hwcaps so that user can use this feature. Signed-off-by: Yeoreum Yun --- Documentation/arch/arm64/elf_hwcaps.rst | 3 +++ arch/arm64/include/asm/hwcap.h | 1 + arch/arm64/include/uapi/asm/hwcap.h | 1 + arch/arm64/kernel/cpufeature.c | 1 + arch/arm64/kernel/cpuinfo.c | 1 + 5 files changed, 7 insertions(+) diff --git a/Documentation/arch/arm64/elf_hwcaps.rst b/Documentation/arch/a= rm64/elf_hwcaps.rst index 358f5af035ff..f58ada4d6cb2 100644 --- a/Documentation/arch/arm64/elf_hwcaps.rst +++ b/Documentation/arch/arm64/elf_hwcaps.rst @@ -438,6 +438,9 @@ HWCAP2_POE HWCAP3_MTE_FAR Functionality implied by ID_AA64PFR2_EL1.MTEFAR =3D=3D 0b0001. =20 +HWCAP3_MTE_STORE_ONLY + Functionality implied by ID_AA64PFR2_EL1.MTESTOREONLY =3D=3D 0b0001. + 4. Unused AT_HWCAP bits ----------------------- =20 diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h index 28dd1ac29ecc..13f94c8ddfc0 100644 --- a/arch/arm64/include/asm/hwcap.h +++ b/arch/arm64/include/asm/hwcap.h @@ -177,6 +177,7 @@ =20 #define __khwcap3_feature(x) (const_ilog2(HWCAP3_ ## x) + 128) #define KERNEL_HWCAP_MTE_FAR __khwcap3_feature(MTE_FAR) +#define KERNEL_HWCAP_MTE_STORE_ONLY __khwcap3_feature(MTE_STORE_ONLY) =20 /* * This yields a mask that user programs can use to figure out what diff --git a/arch/arm64/include/uapi/asm/hwcap.h b/arch/arm64/include/uapi/= asm/hwcap.h index 7d22527a7975..72c78468b806 100644 --- a/arch/arm64/include/uapi/asm/hwcap.h +++ b/arch/arm64/include/uapi/asm/hwcap.h @@ -144,5 +144,6 @@ * HWCAP3 flags - for AT_HWCAP3 */ #define HWCAP3_MTE_FAR (1UL << 0) +#define HWCAP3_MTE_STORE_ONLY (1UL << 1) =20 #endif /* _UAPI__ASM_HWCAP_H */ diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index de42f890bcd7..a2f25a8bed96 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -3208,6 +3208,7 @@ static const struct arm64_cpu_capabilities arm64_elf_= hwcaps[] =3D { HWCAP_CAP(ID_AA64PFR1_EL1, MTE, MTE2, CAP_HWCAP, KERNEL_HWCAP_MTE), HWCAP_CAP(ID_AA64PFR1_EL1, MTE, MTE3, CAP_HWCAP, KERNEL_HWCAP_MTE3), HWCAP_CAP(ID_AA64PFR2_EL1, MTEFAR, IMP, CAP_HWCAP, KERNEL_HWCAP_MTE_FAR), + HWCAP_CAP(ID_AA64PFR2_EL1, MTESTOREONLY, IMP, CAP_HWCAP , KERNEL_HWCAP_MT= E_STORE_ONLY), #endif /* CONFIG_ARM64_MTE */ HWCAP_CAP(ID_AA64MMFR0_EL1, ECV, IMP, CAP_HWCAP, KERNEL_HWCAP_ECV), HWCAP_CAP(ID_AA64MMFR1_EL1, AFP, IMP, CAP_HWCAP, KERNEL_HWCAP_AFP), diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c index 058e21295003..37fd9a56b0ce 100644 --- a/arch/arm64/kernel/cpuinfo.c +++ b/arch/arm64/kernel/cpuinfo.c @@ -161,6 +161,7 @@ static const char *const hwcap_str[] =3D { [KERNEL_HWCAP_SME_STMOP] =3D "smestmop", [KERNEL_HWCAP_SME_SMOP4] =3D "smesmop4", [KERNEL_HWCAP_MTE_FAR] =3D "mtefar", + [KERNEL_HWCAP_MTE_STORE_ONLY] =3D "mtestoreonly", }; =20 #ifdef CONFIG_COMPAT --=20 LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}