From: Julien Grall Date: Mon, 14 Oct 2019 10:21:13 +0000 (+0100) Subject: arm64: cpufeature: Treat ID_AA64ZFR0_EL1 as RAZ when SVE is not enabled X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=ec52c7134b1fcef0edfc56d55072fd4f261ef198;p=linux.git arm64: cpufeature: Treat ID_AA64ZFR0_EL1 as RAZ when SVE is not enabled If CONFIG_ARM64_SVE=n then we fail to report ID_AA64ZFR0_EL1 as 0 when read by userspace, despite being required by the architecture. Although this is theoretically a change in ABI, userspace will first check for the presence of SVE via the HWCAP or the ID_AA64PFR0_EL1.SVE field before probing the ID_AA64ZFR0_EL1 register. Given that these are reported correctly for this configuration, we can safely tighten up the current behaviour. Ensure ID_AA64ZFR0_EL1 is treated as RAZ when CONFIG_ARM64_SVE=n. Signed-off-by: Julien Grall Reviewed-by: Suzuki K Poulose Reviewed-by: Mark Rutland Reviewed-by: Dave Martin Fixes: 06a916feca2b ("arm64: Expose SVE2 features for userspace") Signed-off-by: Will Deacon --- diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index cabebf1a79768..80f459ad0190d 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -176,11 +176,16 @@ static const struct arm64_ftr_bits ftr_id_aa64pfr1[] = { }; static const struct arm64_ftr_bits ftr_id_aa64zfr0[] = { - ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SM4_SHIFT, 4, 0), - ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SHA3_SHIFT, 4, 0), - ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_BITPERM_SHIFT, 4, 0), - ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_AES_SHIFT, 4, 0), - ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SVEVER_SHIFT, 4, 0), + ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE), + FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SM4_SHIFT, 4, 0), + ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE), + FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SHA3_SHIFT, 4, 0), + ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE), + FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_BITPERM_SHIFT, 4, 0), + ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE), + FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_AES_SHIFT, 4, 0), + ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE), + FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SVEVER_SHIFT, 4, 0), ARM64_FTR_END, };