From ce33cea5d833c24fe2564e3f0416c7f2720a9c9c Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Tue, 18 Jul 2023 20:45:44 +0100 Subject: [PATCH 1/4] arm64/cpufeature: Use ARM64_CPUID_FIELD() to match EVT The recently added Enhanced Virtualization Traps cpufeature does not use the ARM64_CPUID_FIELDS() helper, convert it to do so. No functional change. Signed-off-by: Mark Brown Reviewed-by: Zenghui Yu Link: https://lore.kernel.org/r/20230718-arm64-evt-cpuid-helper-v1-1-68375d1e6b92@kernel.org Signed-off-by: Will Deacon --- arch/arm64/kernel/cpufeature.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index f9d456fe132d..bcb006390e55 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -2708,12 +2708,8 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .desc = "Enhanced Virtualization Traps", .capability = ARM64_HAS_EVT, .type = ARM64_CPUCAP_SYSTEM_FEATURE, - .sys_reg = SYS_ID_AA64MMFR2_EL1, - .sign = FTR_UNSIGNED, - .field_pos = ID_AA64MMFR2_EL1_EVT_SHIFT, - .field_width = 4, - .min_field_value = ID_AA64MMFR2_EL1_EVT_IMP, .matches = has_cpuid_feature, + ARM64_CPUID_FIELDS(ID_AA64MMFR2_EL1, EVT, IMP) }, {}, }; From 7f86d128e437990fd08d9e66ae7c1571666cff8a Mon Sep 17 00:00:00 2001 From: Joey Gouly Date: Fri, 4 Aug 2023 15:37:45 +0100 Subject: [PATCH 2/4] arm64: add HWCAP for FEAT_HBC (hinted conditional branches) Add a HWCAP for FEAT_HBC, so that userspace can make a decision on using this feature. Signed-off-by: Joey Gouly Cc: Catalin Marinas Cc: Will Deacon Link: https://lore.kernel.org/r/20230804143746.3900803-2-joey.gouly@arm.com Signed-off-by: Will Deacon --- 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 + 4 files changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h index 692b1ec663b2..521267478d18 100644 --- a/arch/arm64/include/asm/hwcap.h +++ b/arch/arm64/include/asm/hwcap.h @@ -138,6 +138,7 @@ #define KERNEL_HWCAP_SME_B16B16 __khwcap2_feature(SME_B16B16) #define KERNEL_HWCAP_SME_F16F16 __khwcap2_feature(SME_F16F16) #define KERNEL_HWCAP_MOPS __khwcap2_feature(MOPS) +#define KERNEL_HWCAP_HBC __khwcap2_feature(HBC) /* * 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 a2cac4305b1e..53026f45a509 100644 --- a/arch/arm64/include/uapi/asm/hwcap.h +++ b/arch/arm64/include/uapi/asm/hwcap.h @@ -103,5 +103,6 @@ #define HWCAP2_SME_B16B16 (1UL << 41) #define HWCAP2_SME_F16F16 (1UL << 42) #define HWCAP2_MOPS (1UL << 43) +#define HWCAP2_HBC (1UL << 44) #endif /* _UAPI__ASM_HWCAP_H */ diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index bcb006390e55..a5f533f63b60 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -222,7 +222,7 @@ static const struct arm64_ftr_bits ftr_id_aa64isar1[] = { static const struct arm64_ftr_bits ftr_id_aa64isar2[] = { ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_EL1_CSSC_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_EL1_RPRFM_SHIFT, 4, 0), - ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_HIGHER_SAFE, ID_AA64ISAR2_EL1_BC_SHIFT, 4, 0), + ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_SAFE, ID_AA64ISAR2_EL1_BC_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_EL1_MOPS_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH), FTR_STRICT, FTR_EXACT, ID_AA64ISAR2_EL1_APA3_SHIFT, 4, 0), @@ -2840,6 +2840,7 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = { HWCAP_CAP(ID_AA64ISAR2_EL1, RPRES, IMP, CAP_HWCAP, KERNEL_HWCAP_RPRES), HWCAP_CAP(ID_AA64ISAR2_EL1, WFxT, IMP, CAP_HWCAP, KERNEL_HWCAP_WFXT), HWCAP_CAP(ID_AA64ISAR2_EL1, MOPS, IMP, CAP_HWCAP, KERNEL_HWCAP_MOPS), + HWCAP_CAP(ID_AA64ISAR2_EL1, BC, IMP, CAP_HWCAP, KERNEL_HWCAP_HBC), #ifdef CONFIG_ARM64_SME HWCAP_CAP(ID_AA64PFR1_EL1, SME, IMP, CAP_HWCAP, KERNEL_HWCAP_SME), HWCAP_CAP(ID_AA64SMFR0_EL1, FA64, IMP, CAP_HWCAP, KERNEL_HWCAP_SME_FA64), diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c index 58622dc85917..98fda8500535 100644 --- a/arch/arm64/kernel/cpuinfo.c +++ b/arch/arm64/kernel/cpuinfo.c @@ -126,6 +126,7 @@ static const char *const hwcap_str[] = { [KERNEL_HWCAP_SME_B16B16] = "smeb16b16", [KERNEL_HWCAP_SME_F16F16] = "smef16f16", [KERNEL_HWCAP_MOPS] = "mops", + [KERNEL_HWCAP_HBC] = "hbc", }; #ifdef CONFIG_COMPAT From d70175b1470c4bdc8643fd744d722a00c7f0fb17 Mon Sep 17 00:00:00 2001 From: Joey Gouly Date: Fri, 4 Aug 2023 15:37:46 +0100 Subject: [PATCH 3/4] selftests/arm64: add HWCAP2_HBC test Add a test for the newly added HWCAP2_HBC. Signed-off-by: Joey Gouly Cc: Catalin Marinas Cc: Will Deacon Link: https://lore.kernel.org/r/20230804143746.3900803-3-joey.gouly@arm.com Signed-off-by: Will Deacon --- tools/testing/selftests/arm64/abi/hwcap.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/tools/testing/selftests/arm64/abi/hwcap.c b/tools/testing/selftests/arm64/abi/hwcap.c index d4ad813fed10..fabeac9a1b5e 100644 --- a/tools/testing/selftests/arm64/abi/hwcap.c +++ b/tools/testing/selftests/arm64/abi/hwcap.c @@ -208,6 +208,13 @@ static void svebf16_sigill(void) asm volatile(".inst 0x658aa000" : : : "z0"); } +static void hbc_sigill(void) +{ + /* BC.EQ +4 */ + asm volatile("cmp xzr, xzr\n" + ".inst 0x54000030" : : : "cc"); +} + static const struct hwcap_data { const char *name; unsigned long at_hwcap; @@ -386,6 +393,14 @@ static const struct hwcap_data { .hwcap_bit = HWCAP2_SVE_EBF16, .cpuinfo = "sveebf16", }, + { + .name = "HBC", + .at_hwcap = AT_HWCAP2, + .hwcap_bit = HWCAP2_HBC, + .cpuinfo = "hbc", + .sigill_fn = hbc_sigill, + .sigill_reliable = true, + }, }; static bool seen_sigill; From 01948b09edc3fecf8486c57c2d2fb8b80886f3d0 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Mon, 31 Jul 2023 14:58:48 +0100 Subject: [PATCH 4/4] arm64/fpsimd: Only provide the length to cpufeature for xCR registers For both SVE and SME we abuse the generic register field comparison support in the cpufeature code as part of our detection of unsupported variations in the vector lengths available to PEs, reporting the maximum vector lengths via ZCR_EL1.LEN and SMCR_EL1.LEN. Since these are configuration registers rather than identification registers the assumptions the cpufeature code makes about how unknown bitfields behave are invalid, leading to warnings when SME features like FA64 are enabled and we hotplug a CPU: CPU features: SANITY CHECK: Unexpected variation in SYS_SMCR_EL1. Boot CPU: 0x0000000000000f, CPU3: 0x0000008000000f CPU features: Unsupported CPU feature variation detected. SVE has no controls other than the vector length so is not yet impacted but the same issue will apply there if any are defined. Since the only field we are interested in having the cpufeature code handle is the length field and we use a custom read function to obtain the value we can avoid these warnings by filtering out all other bits when we return the register value, if we're doing that we don't need to bother reading the register at all and can simply use the RDVL/RDSVL value we were filling in instead. Fixes: 2e0f2478ea37 ("arm64/sve: Probe SVE capabilities and usable vector lengths") FixeS: b42990d3bf77 ("arm64/sme: Identify supported SME vector lengths at boot") Signed-off-by: Mark Brown Reviewed-by: Catalin Marinas Link: https://lore.kernel.org/r/20230731-arm64-sme-fa64-hotplug-v2-1-7714c00dd902@kernel.org Signed-off-by: Will Deacon --- arch/arm64/kernel/fpsimd.c | 22 ++++------------------ 1 file changed, 4 insertions(+), 18 deletions(-) diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 89d54a5242d1..8e9a3451af4c 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -1178,9 +1178,6 @@ void sve_kernel_enable(const struct arm64_cpu_capabilities *__always_unused p) */ u64 read_zcr_features(void) { - u64 zcr; - unsigned int vq_max; - /* * Set the maximum possible VL, and write zeroes to all other * bits to see if they stick. @@ -1188,12 +1185,8 @@ u64 read_zcr_features(void) sve_kernel_enable(NULL); write_sysreg_s(ZCR_ELx_LEN_MASK, SYS_ZCR_EL1); - zcr = read_sysreg_s(SYS_ZCR_EL1); - zcr &= ~(u64)ZCR_ELx_LEN_MASK; /* find sticky 1s outside LEN field */ - vq_max = sve_vq_from_vl(sve_get_vl()); - zcr |= vq_max - 1; /* set LEN field to maximum effective value */ - - return zcr; + /* Return LEN value that would be written to get the maximum VL */ + return sve_vq_from_vl(sve_get_vl()) - 1; } void __init sve_setup(void) @@ -1348,9 +1341,6 @@ void fa64_kernel_enable(const struct arm64_cpu_capabilities *__always_unused p) */ u64 read_smcr_features(void) { - u64 smcr; - unsigned int vq_max; - sme_kernel_enable(NULL); /* @@ -1359,12 +1349,8 @@ u64 read_smcr_features(void) write_sysreg_s(read_sysreg_s(SYS_SMCR_EL1) | SMCR_ELx_LEN_MASK, SYS_SMCR_EL1); - smcr = read_sysreg_s(SYS_SMCR_EL1); - smcr &= ~(u64)SMCR_ELx_LEN_MASK; /* Only the LEN field */ - vq_max = sve_vq_from_vl(sme_get_vl()); - smcr |= vq_max - 1; /* set LEN field to maximum effective value */ - - return smcr; + /* Return LEN value that would be written to get the maximum VL */ + return sve_vq_from_vl(sme_get_vl()) - 1; } void __init sme_setup(void)