SVE 2.1 introduced a new feature FEAT_SVE_B16B16 which adds instructions supporting the BFloat16 floating point format. Report this to userspace through the ID registers and hwcap.

Reported-by: Peter Maydell peter.maydell@linaro.org Signed-off-by: Mark Brown broonie@kernel.org --- Documentation/arch/arm64/cpu-feature-registers.rst | 2 ++ 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 | 3 +++ arch/arm64/kernel/cpuinfo.c | 1 + arch/arm64/tools/sysreg | 6 +++++- 7 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/Documentation/arch/arm64/cpu-feature-registers.rst b/Documentation/arch/arm64/cpu-feature-registers.rst index 4e4625f2455f..0c9edc3adb7b 100644 --- a/Documentation/arch/arm64/cpu-feature-registers.rst +++ b/Documentation/arch/arm64/cpu-feature-registers.rst @@ -266,6 +266,8 @@ infrastructure: +------------------------------+---------+---------+ | SHA3 | [35-32] | y | +------------------------------+---------+---------+ + | B16B16 | [27-24] | y | + +------------------------------+---------+---------+ | BF16 | [23-20] | y | +------------------------------+---------+---------+ | BitPerm | [19-16] | y | diff --git a/Documentation/arch/arm64/elf_hwcaps.rst b/Documentation/arch/arm64/elf_hwcaps.rst index 8c8addb4194c..077b9552ef38 100644 --- a/Documentation/arch/arm64/elf_hwcaps.rst +++ b/Documentation/arch/arm64/elf_hwcaps.rst @@ -305,6 +305,9 @@ HWCAP2_SMEF16F16 HWCAP2_MOPS Functionality implied by ID_AA64ISAR2_EL1.MOPS == 0b0001.

+HWCAP2_SVE_B16B16 + Functionality implied by ID_AA64ZFR0_EL1.B16B16 == 0b0001. + 4. Unused AT_HWCAP bits -----------------------

diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h index 521267478d18..210a41f8b10a 100644 --- a/arch/arm64/include/asm/hwcap.h +++ b/arch/arm64/include/asm/hwcap.h @@ -139,6 +139,7 @@ #define KERNEL_HWCAP_SME_F16F16 __khwcap2_feature(SME_F16F16) #define KERNEL_HWCAP_MOPS __khwcap2_feature(MOPS) #define KERNEL_HWCAP_HBC __khwcap2_feature(HBC) +#define KERNEL_HWCAP_SVE_B16B16 __khwcap2_feature(SVE_B16B16)

/* * 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 53026f45a509..6faf549077c5 100644 --- a/arch/arm64/include/uapi/asm/hwcap.h +++ b/arch/arm64/include/uapi/asm/hwcap.h @@ -104,5 +104,6 @@ #define HWCAP2_SME_F16F16 (1UL << 42) #define HWCAP2_MOPS (1UL << 43) #define HWCAP2_HBC (1UL << 44) +#define HWCAP2_SVE_B16B16 (1UL << 45)

#endif /* _UAPI__ASM_HWCAP_H */ diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index b018ae12ff5f..a8d373c0e476 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -277,6 +277,8 @@ static const struct arm64_ftr_bits ftr_id_aa64zfr0[] = { FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_EL1_SM4_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE), FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_EL1_SHA3_SHIFT, 4, 0), + ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE), + FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_EL1_B16B16_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE), FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_EL1_BF16_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE), @@ -2820,6 +2822,7 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = { HWCAP_CAP(ID_AA64ZFR0_EL1, AES, IMP, CAP_HWCAP, KERNEL_HWCAP_SVEAES), HWCAP_CAP(ID_AA64ZFR0_EL1, AES, PMULL128, CAP_HWCAP, KERNEL_HWCAP_SVEPMULL), HWCAP_CAP(ID_AA64ZFR0_EL1, BitPerm, IMP, CAP_HWCAP, KERNEL_HWCAP_SVEBITPERM), + HWCAP_CAP(ID_AA64ZFR0_EL1, B16B16, IMP, CAP_HWCAP, KERNEL_HWCAP_SVE_B16B16), HWCAP_CAP(ID_AA64ZFR0_EL1, BF16, IMP, CAP_HWCAP, KERNEL_HWCAP_SVEBF16), HWCAP_CAP(ID_AA64ZFR0_EL1, BF16, EBF16, CAP_HWCAP, KERNEL_HWCAP_SVE_EBF16), HWCAP_CAP(ID_AA64ZFR0_EL1, SHA3, IMP, CAP_HWCAP, KERNEL_HWCAP_SVESHA3), diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c index 98fda8500535..ea2a31988103 100644 --- a/arch/arm64/kernel/cpuinfo.c +++ b/arch/arm64/kernel/cpuinfo.c @@ -127,6 +127,7 @@ static const char *const hwcap_str[] = { [KERNEL_HWCAP_SME_F16F16] = "smef16f16", [KERNEL_HWCAP_MOPS] = "mops", [KERNEL_HWCAP_HBC] = "hbc", + [KERNEL_HWCAP_SVE_B16B16] = "sveb16b16", };

#ifdef CONFIG_COMPAT diff --git a/arch/arm64/tools/sysreg b/arch/arm64/tools/sysreg index 2517ef7c21cf..90bb04603811 100644 --- a/arch/arm64/tools/sysreg +++ b/arch/arm64/tools/sysreg @@ -1026,7 +1026,11 @@ UnsignedEnum 35:32 SHA3 0b0000 NI 0b0001 IMP EndEnum -Res0 31:24 +Res0 31:28 +UnsignedEnum 27:24 B16B16 + 0b0000 NI + 0b0001 IMP +EndEnum UnsignedEnum 23:20 BF16 0b0000 NI 0b0001 IMP