From: Yeoreum Yun Date: Wed, 18 Jun 2025 09:29:53 +0000 (+0100) Subject: arm64/hwcaps: Add MTE_STORE_ONLY hwcaps X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f620372209bfe5b1c468540320a0bc3549d6afc7;p=thirdparty%2Fkernel%2Fstable.git arm64/hwcaps: Add MTE_STORE_ONLY hwcaps 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 Link: https://lore.kernel.org/r/20250618092957.2069907-5-yeoreum.yun@arm.com Signed-off-by: Catalin Marinas --- diff --git a/Documentation/arch/arm64/elf_hwcaps.rst b/Documentation/arch/arm64/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 == 0b0001. +HWCAP3_MTE_STORE_ONLY + Functionality implied by ID_AA64PFR2_EL1.MTESTOREONLY == 0b0001. + 4. Unused AT_HWCAP bits ----------------------- 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 @@ #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) /* * 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) #endif /* _UAPI__ASM_HWCAP_H */ diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index fdc48aa1f0e2..b4204fa743f0 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -3228,6 +3228,7 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = { 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_MTE_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 e552cb305641..ba834909a28b 100644 --- a/arch/arm64/kernel/cpuinfo.c +++ b/arch/arm64/kernel/cpuinfo.c @@ -161,6 +161,7 @@ static const char *const hwcap_str[] = { [KERNEL_HWCAP_SME_STMOP] = "smestmop", [KERNEL_HWCAP_SME_SMOP4] = "smesmop4", [KERNEL_HWCAP_MTE_FAR] = "mtefar", + [KERNEL_HWCAP_MTE_STORE_ONLY] = "mtestoreonly", }; #ifdef CONFIG_COMPAT