From: Yicong Yang <yangyicong@hisilicon.com> driver inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IC1F41 ---------------------------------------------------------------------- Armv8.7 introduces single-copy atomic 64-byte loads and stores instructions and its variants named under FEAT_{LS64, LS64_V}. These features are identified by ID_AA64ISAR1_EL1.LS64 and the use of such instructions in userspace (EL0) can be trapped. In order to support the use of corresponding instructions in userspace: - Make ID_AA64ISAR1_EL1.LS64 visbile to userspace - Add identifying and enabling in the cpufeature list - Expose these support of these features to userspace through HWCAP3 and cpuinfo Signed-off-by: Yicong Yang <yangyicong@hisilicon.com> Reviewed-by: Yicong Yang <yangyicong@hisilicon.com> Signed-off-by: Hongye Lin <linhongye@h-partners.com> --- Documentation/arch/arm64/booting.rst | 12 ++++++ Documentation/arch/arm64/elf_hwcaps.rst | 6 +++ arch/arm64/include/asm/hwcap.h | 3 ++ arch/arm64/include/uapi/asm/hwcap.h | 6 +++ arch/arm64/kernel/cpufeature.c | 51 +++++++++++++++++++++++++ arch/arm64/kernel/cpuinfo.c | 2 + arch/arm64/tools/cpucaps | 4 +- 7 files changed, 82 insertions(+), 2 deletions(-) diff --git a/Documentation/arch/arm64/booting.rst b/Documentation/arch/arm64/booting.rst index 408d2e27b641..b540e0933dde 100644 --- a/Documentation/arch/arm64/booting.rst +++ b/Documentation/arch/arm64/booting.rst @@ -438,6 +438,18 @@ Before jumping into the kernel, the following conditions must be met: - HCRX_EL2.TALLINT must be initialised to 0b0. + For CPUs support for 64-byte loads and stores without status (FEAT_LS64): + + - If the kernel is entered at EL1 and EL2 is present: + + - HCRX_EL2.EnALS (bit 1) must be initialised to 0b1. + + For CPUs support for 64-byte loads and stores with status (FEAT_LS64_V): + + - If the kernel is entered at EL1 and EL2 is present: + + - HCRX_EL2.EnASR (bit 2) must be initialised to 0b1. + The requirements described above for CPU mode, caches, MMUs, architected timers, coherency and system registers apply to all CPUs. All CPUs must enter the kernel in the same exception level. Where the values documented diff --git a/Documentation/arch/arm64/elf_hwcaps.rst b/Documentation/arch/arm64/elf_hwcaps.rst index f88a24d621dd..129d2e9862b8 100644 --- a/Documentation/arch/arm64/elf_hwcaps.rst +++ b/Documentation/arch/arm64/elf_hwcaps.rst @@ -320,6 +320,12 @@ HWCAP2_MOPS HWCAP2_HBC Functionality implied by ID_AA64ISAR2_EL1.BC == 0b0001. +HWCAP3_LS64 + Functionality implied by ID_AA64ISAR1_EL1.LS64 == 0b0001. + +HWCAP3_LS64_V + Functionality implied by ID_AA64ISAR1_EL1.LS64 == 0b0010. + 4. Unused AT_HWCAP bits ----------------------- diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h index 2e914609db93..d68a3f2f6bbb 100644 --- a/arch/arm64/include/asm/hwcap.h +++ b/arch/arm64/include/asm/hwcap.h @@ -140,6 +140,9 @@ #define KERNEL_HWCAP_MOPS __khwcap2_feature(MOPS) #define KERNEL_HWCAP_HBC __khwcap2_feature(HBC) +#define KERNEL_HWCAP_LS64 __khwcap3_feature(LS64) +#define KERNEL_HWCAP_LS64_V __khwcap3_feature(LS64_V) + /* * This yields a mask that user programs can use to figure out what * instruction set this cpu supports. diff --git a/arch/arm64/include/uapi/asm/hwcap.h b/arch/arm64/include/uapi/asm/hwcap.h index 53026f45a509..13a8ad7bc492 100644 --- a/arch/arm64/include/uapi/asm/hwcap.h +++ b/arch/arm64/include/uapi/asm/hwcap.h @@ -105,4 +105,10 @@ #define HWCAP2_MOPS (1UL << 43) #define HWCAP2_HBC (1UL << 44) +/* + * HWCAP3 flags - for AT_HWCAP3 + */ +#define HWCAP3_LS64 (1UL << 0) +#define HWCAP3_LS64_V (1UL << 1) + #endif /* _UAPI__ASM_HWCAP_H */ diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index c49a76ad747f..16b335b918fd 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -200,6 +200,7 @@ static const struct arm64_ftr_bits ftr_id_aa64isar0[] = { }; static const struct arm64_ftr_bits ftr_id_aa64isar1[] = { + ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_EL1_LS64_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_EL1_I8MM_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_EL1_DGH_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_EL1_BF16_SHIFT, 4, 0), @@ -2133,6 +2134,38 @@ static void cpu_enable_e0pd(struct arm64_cpu_capabilities const *cap) static bool enable_pseudo_nmi; #endif +static bool has_ls64(const struct arm64_cpu_capabilities *entry, int __unused) +{ + u64 ls64; + + ls64 = cpuid_feature_extract_field(__read_sysreg_by_encoding(entry->sys_reg), + entry->field_pos, entry->sign); + + if (ls64 == ID_AA64ISAR1_EL1_LS64_NI || + ls64 > ID_AA64ISAR1_EL1_LS64_LS64_ACCDATA) + return false; + + if (entry->capability == ARM64_HAS_LS64 && + ls64 >= ID_AA64ISAR1_EL1_LS64_LS64) + return true; + + if (entry->capability == ARM64_HAS_LS64_V && + ls64 >= ID_AA64ISAR1_EL1_LS64_LS64_V) + return true; + + return false; +} + +static void cpu_enable_ls64(struct arm64_cpu_capabilities const *cap) +{ + sysreg_clear_set(sctlr_el1, SCTLR_EL1_EnALS, SCTLR_EL1_EnALS); +} + +static void cpu_enable_ls64_v(struct arm64_cpu_capabilities const *cap) +{ + sysreg_clear_set(sctlr_el1, SCTLR_EL1_EnASR, SCTLR_EL1_EnASR); +} + #ifdef CONFIG_ARM64_PSEUDO_NMI static int __init early_enable_pseudo_nmi(char *p) { @@ -2972,6 +3005,22 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .matches = has_xint_support, }, #endif + { + .desc = "LS64", + .capability = ARM64_HAS_LS64, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .matches = has_ls64, + .cpu_enable = cpu_enable_ls64, + ARM64_CPUID_FIELDS(ID_AA64ISAR1_EL1, LS64, LS64) + }, + { + .desc = "LS64_V", + .capability = ARM64_HAS_LS64_V, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .matches = has_ls64, + .cpu_enable = cpu_enable_ls64_v, + ARM64_CPUID_FIELDS(ID_AA64ISAR1_EL1, LS64, LS64_V) + }, {}, }; @@ -3080,6 +3129,8 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = { HWCAP_CAP(ID_AA64ISAR1_EL1, BF16, EBF16, CAP_HWCAP, KERNEL_HWCAP_EBF16), HWCAP_CAP(ID_AA64ISAR1_EL1, DGH, IMP, CAP_HWCAP, KERNEL_HWCAP_DGH), HWCAP_CAP(ID_AA64ISAR1_EL1, I8MM, IMP, CAP_HWCAP, KERNEL_HWCAP_I8MM), + HWCAP_CAP(ID_AA64ISAR1_EL1, LS64, LS64, CAP_HWCAP, KERNEL_HWCAP_LS64), + HWCAP_CAP(ID_AA64ISAR1_EL1, LS64, LS64_V, CAP_HWCAP, KERNEL_HWCAP_LS64_V), HWCAP_CAP(ID_AA64MMFR2_EL1, AT, IMP, CAP_HWCAP, KERNEL_HWCAP_USCAT), #ifdef CONFIG_ARM64_SVE HWCAP_CAP(ID_AA64PFR0_EL1, SVE, IMP, CAP_HWCAP, KERNEL_HWCAP_SVE), diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c index 7466b6066d87..dade66047478 100644 --- a/arch/arm64/kernel/cpuinfo.c +++ b/arch/arm64/kernel/cpuinfo.c @@ -82,6 +82,8 @@ static const char *const hwcap_str[] = { [KERNEL_HWCAP_SB] = "sb", [KERNEL_HWCAP_PACA] = "paca", [KERNEL_HWCAP_PACG] = "pacg", + [KERNEL_HWCAP_LS64] = "ls64", + [KERNEL_HWCAP_LS64_V] = "ls64_v", [KERNEL_HWCAP_DCPODP] = "dcpodp", [KERNEL_HWCAP_SVE2] = "sve2", [KERNEL_HWCAP_SVEAES] = "sveaes", diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps index f2ddced689b5..27d93050e5da 100644 --- a/arch/arm64/tools/cpucaps +++ b/arch/arm64/tools/cpucaps @@ -110,8 +110,8 @@ WORKAROUND_HISI_HIP08_RU_PREFETCH WORKAROUND_HISILICON_1980005 HAS_XCALL HAS_XINT -KABI_RESERVE_3 -KABI_RESERVE_4 +HAS_LS64 +HAS_LS64_V KABI_RESERVE_5 KABI_RESERVE_6 KABI_RESERVE_7 -- 2.33.0