[PATCH v1] arm64/sysreg: Add hwcap for SVE EBF16
From: Mark Brown <broonie@kernel.org>
Date: 2022-08-15 13:21:54
Subsystem:
arm64 port (aarch64 architecture), documentation, the rest · Maintainers:
Catalin Marinas, Will Deacon, Jonathan Corbet, Linus Torvalds
SVE has a separate identification register indicating support for BFloat16 operations. Add a hwcap identifying support for EBF16 in this register, mirroring what we did for the non-SVE case. While there is currently an architectural requirement for BF16 support to be the same in SVE and non-SVE contexts there are separate identification registers this separate hwcap helps avoid issues if that requirement were to be relaxed in the future, we have already chosen to have a separate capability for base BF16 support. Signed-off-by: Mark Brown <broonie@kernel.org> --- Documentation/arm64/elf_hwcaps.rst | 4 ++++ 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, 8 insertions(+)
diff --git a/Documentation/arm64/elf_hwcaps.rst b/Documentation/arm64/elf_hwcaps.rst
index 31fc10b833dd..37fbe844fa7e 100644
--- a/Documentation/arm64/elf_hwcaps.rst
+++ b/Documentation/arm64/elf_hwcaps.rst@@ -305,6 +305,10 @@ HWCAP2_EBF16 Functionality implied by ID_AA64ISAR1_EL1.BF16 == 0b0010. +HWCAP2_SVE_EBF16 + + Functionality implied by ID_AA64ZFR0_EL1.BF16 == 0b0010. + 4. Unused AT_HWCAP bits -----------------------
diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h
index cef4ae7a3d8b..298b386d3ebe 100644
--- a/arch/arm64/include/asm/hwcap.h
+++ b/arch/arm64/include/asm/hwcap.h@@ -119,6 +119,7 @@ #define KERNEL_HWCAP_SME_FA64 __khwcap2_feature(SME_FA64) #define KERNEL_HWCAP_WFXT __khwcap2_feature(WFXT) #define KERNEL_HWCAP_EBF16 __khwcap2_feature(EBF16) +#define KERNEL_HWCAP_SVE_EBF16 __khwcap2_feature(SVE_EBF16) /* * 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 1ad2568a2569..9b245da6f507 100644
--- a/arch/arm64/include/uapi/asm/hwcap.h
+++ b/arch/arm64/include/uapi/asm/hwcap.h@@ -92,5 +92,6 @@ #define HWCAP2_SME_FA64 (1 << 30) #define HWCAP2_WFXT (1UL << 31) #define HWCAP2_EBF16 (1UL << 32) +#define HWCAP2_SVE_EBF16 (1UL << 33) #endif /* _UAPI__ASM_HWCAP_H */
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index ad64cab0a2ba..4ebd25159d04 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c@@ -2732,6 +2732,7 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = { HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_EL1_AES_SHIFT, 4, FTR_UNSIGNED, ID_AA64ZFR0_EL1_AES_PMULL128, CAP_HWCAP, KERNEL_HWCAP_SVEPMULL), HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_EL1_BitPerm_SHIFT, 4, FTR_UNSIGNED, ID_AA64ZFR0_EL1_BitPerm_IMP, CAP_HWCAP, KERNEL_HWCAP_SVEBITPERM), HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_EL1_BF16_SHIFT, 4, FTR_UNSIGNED, ID_AA64ZFR0_EL1_BF16_IMP, CAP_HWCAP, KERNEL_HWCAP_SVEBF16), + HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_EL1_BF16_SHIFT, 4, FTR_UNSIGNED, ID_AA64ZFR0_EL1_BF16_EBF16, CAP_HWCAP, KERNEL_HWCAP_SVE_EBF16), HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_EL1_SHA3_SHIFT, 4, FTR_UNSIGNED, ID_AA64ZFR0_EL1_SHA3_IMP, CAP_HWCAP, KERNEL_HWCAP_SVESHA3), HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_EL1_SM4_SHIFT, 4, FTR_UNSIGNED, ID_AA64ZFR0_EL1_SM4_IMP, CAP_HWCAP, KERNEL_HWCAP_SVESM4), HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_EL1_I8MM_SHIFT, 4, FTR_UNSIGNED, ID_AA64ZFR0_EL1_I8MM_IMP, CAP_HWCAP, KERNEL_HWCAP_SVEI8MM),
diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
index d7702f39b4d3..28d4f442b0bc 100644
--- a/arch/arm64/kernel/cpuinfo.c
+++ b/arch/arm64/kernel/cpuinfo.c@@ -115,6 +115,7 @@ static const char *const hwcap_str[] = { [KERNEL_HWCAP_SME_FA64] = "smefa64", [KERNEL_HWCAP_WFXT] = "wfxt", [KERNEL_HWCAP_EBF16] = "ebf16", + [KERNEL_HWCAP_SVE_EBF16] = "sveebf16", }; #ifdef CONFIG_COMPAT
base-commit: 892f7237b3ffb090f1b1f1e55fe7c50664405aed -- 2.30.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel