/* * Contains CPU feature definitions * * Copyright (C) 2015 ARM Ltd. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . */ #define pr_fmt(fmt) "CPU features: " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include unsigned long elf_hwcap __read_mostly; EXPORT_SYMBOL_GPL(elf_hwcap); #ifdef CONFIG_COMPAT #define COMPAT_ELF_HWCAP_DEFAULT \ (COMPAT_HWCAP_HALF|COMPAT_HWCAP_THUMB|\ COMPAT_HWCAP_FAST_MULT|COMPAT_HWCAP_EDSP|\ COMPAT_HWCAP_TLS|COMPAT_HWCAP_IDIV|\ COMPAT_HWCAP_LPAE) unsigned int compat_elf_hwcap __read_mostly = COMPAT_ELF_HWCAP_DEFAULT; unsigned int compat_elf_hwcap2 __read_mostly; #endif DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS); EXPORT_SYMBOL(cpu_hwcaps); DEFINE_PER_CPU_READ_MOSTLY(const char *, this_cpu_vector) = vectors; /* * Flag to indicate if we have computed the system wide * capabilities based on the boot time active CPUs. This * will be used to determine if a new booting CPU should * go through the verification process to make sure that it * supports the system capabilities, without using a hotplug * notifier. */ static bool sys_caps_initialised; static inline void set_sys_caps_initialised(void) { sys_caps_initialised = true; } static int dump_cpu_hwcaps(struct notifier_block *self, unsigned long v, void *p) { /* file-wide pr_fmt adds "CPU features: " prefix */ pr_emerg("0x%*pb\n", ARM64_NCAPS, &cpu_hwcaps); return 0; } static struct notifier_block cpu_hwcaps_notifier = { .notifier_call = dump_cpu_hwcaps }; static int __init register_cpu_hwcaps_dumper(void) { atomic_notifier_chain_register(&panic_notifier_list, &cpu_hwcaps_notifier); return 0; } __initcall(register_cpu_hwcaps_dumper); DEFINE_STATIC_KEY_ARRAY_FALSE(cpu_hwcap_keys, ARM64_NCAPS); EXPORT_SYMBOL(cpu_hwcap_keys); #define __ARM64_FTR_BITS(SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \ { \ .sign = SIGNED, \ .visible = VISIBLE, \ .strict = STRICT, \ .type = TYPE, \ .shift = SHIFT, \ .width = WIDTH, \ .safe_val = SAFE_VAL, \ } /* Define a feature with unsigned values */ #define ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \ __ARM64_FTR_BITS(FTR_UNSIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) /* Define a feature with a signed value */ #define S_ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \ __ARM64_FTR_BITS(FTR_SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) #define ARM64_FTR_END \ { \ .width = 0, \ } /* meta feature for alternatives */ static bool __maybe_unused cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry, int __unused); /* * NOTE: Any changes to the visibility of features should be kept in * sync with the documentation of the CPU feature register ABI. */ static const struct arm64_ftr_bits ftr_id_aa64isar0[] = { ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_TS_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_FHM_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_DP_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SM4_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SM3_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA3_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_RDM_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_ATOMICS_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_CRC32_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA2_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA1_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_AES_SHIFT, 4, 0), ARM64_FTR_END, }; static const struct arm64_ftr_bits ftr_id_aa64isar1[] = { ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_LRCPC_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_FCMA_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_JSCVT_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_DPB_SHIFT, 4, 0), ARM64_FTR_END, }; static const struct arm64_ftr_bits ftr_id_aa64isar2[] = { ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_HIGHER_SAFE, ID_AA64ISAR2_CLEARBHB_SHIFT, 4, 0), ARM64_FTR_END, }; static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = { ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_CSV3_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_CSV2_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_DIT_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE), FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_SVE_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_RAS_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_GIC_SHIFT, 4, 0), S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_ASIMD_SHIFT, 4, ID_AA64PFR0_ASIMD_NI), S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_FP_SHIFT, 4, ID_AA64PFR0_FP_NI), ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL3_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL2_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_SHIFT, 4, ID_AA64PFR0_EL1_64BIT_ONLY), ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL0_SHIFT, 4, ID_AA64PFR0_EL0_64BIT_ONLY), ARM64_FTR_END, }; static const struct arm64_ftr_bits ftr_id_aa64pfr1[] = { ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_SSBS_SHIFT, 4, ID_AA64PFR1_SSBS_PSTATE_NI), ARM64_FTR_END, }; static const struct arm64_ftr_bits ftr_id_aa64mmfr0[] = { /* * We already refuse to boot CPUs that don't support our configured * page size, so we can only detect mismatches for a page size other * than the one we're currently using. Unfortunately, SoCs like this * exist in the wild so, even though we don't like it, we'll have to go * along with it and treat them as non-strict. */ S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN4_SHIFT, 4, ID_AA64MMFR0_TGRAN4_NI), S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN64_SHIFT, 4, ID_AA64MMFR0_TGRAN64_NI), ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN16_SHIFT, 4, ID_AA64MMFR0_TGRAN16_NI), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_BIGENDEL0_SHIFT, 4, 0), /* Linux shouldn't care about secure memory */ ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_SNSMEM_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_BIGENDEL_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_ASID_SHIFT, 4, 0), /* * Differing PARange is fine as long as all peripherals and memory are mapped * within the minimum PARange of all CPUs */ ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_PARANGE_SHIFT, 4, 0), ARM64_FTR_END, }; static const struct arm64_ftr_bits ftr_id_aa64mmfr1[] = { ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_PAN_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_LOR_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_HPD_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_VHE_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_VMIDBITS_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_HADBS_SHIFT, 4, 0), ARM64_FTR_END, }; static const struct arm64_ftr_bits ftr_id_aa64mmfr2[] = { ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_FWB_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_AT_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_LVA_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_IESB_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_LSM_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_UAO_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_CNP_SHIFT, 4, 0), ARM64_FTR_END, }; static const struct arm64_ftr_bits ftr_ctr[] = { ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, 31, 1, 1), /* RES1 */ ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_DIC_SHIFT, 1, 1), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_IDC_SHIFT, 1, 1), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_OR_ZERO_SAFE, CTR_CWG_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_OR_ZERO_SAFE, CTR_ERG_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_DMINLINE_SHIFT, 4, 1), /* * Linux can handle differing I-cache policies. Userspace JITs will * make use of *minLine. * If we have differing I-cache policies, report it as the weakest - VIPT. */ ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_EXACT, 14, 2, ICACHE_POLICY_VIPT), /* L1Ip */ ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_IMINLINE_SHIFT, 4, 0), ARM64_FTR_END, }; struct arm64_ftr_reg arm64_ftr_reg_ctrel0 = { .name = "SYS_CTR_EL0", .ftr_bits = ftr_ctr }; static const struct arm64_ftr_bits ftr_id_mmfr0[] = { S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0xf), /* InnerShr */ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0), /* FCSE */ ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, 20, 4, 0), /* AuxReg */ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0), /* TCM */ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0), /* ShareLvl */ S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0xf), /* OuterShr */ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0), /* PMSA */ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0), /* VMSA */ ARM64_FTR_END, }; static const struct arm64_ftr_bits ftr_id_aa64dfr0[] = { ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 36, 28, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64DFR0_PMSVER_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_CTX_CMPS_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_WRPS_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_BRPS_SHIFT, 4, 0), /* * We can instantiate multiple PMU instances with different levels * of support. */ S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64DFR0_PMUVER_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64DFR0_DEBUGVER_SHIFT, 4, 0x6), ARM64_FTR_END, }; static const struct arm64_ftr_bits ftr_mvfr2[] = { ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0), /* FPMisc */ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0), /* SIMDMisc */ ARM64_FTR_END, }; static const struct arm64_ftr_bits ftr_dczid[] = { ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, 4, 1, 1), /* DZP */ ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0), /* BS */ ARM64_FTR_END, }; static const struct arm64_ftr_bits ftr_id_isar5[] = { ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_RDM_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_CRC32_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SHA2_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SHA1_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_AES_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SEVL_SHIFT, 4, 0), ARM64_FTR_END, }; static const struct arm64_ftr_bits ftr_id_mmfr4[] = { ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0), /* ac2 */ ARM64_FTR_END, }; static const struct arm64_ftr_bits ftr_id_pfr0[] = { ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0), /* State3 */ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0), /* State2 */ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0), /* State1 */ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0), /* State0 */ ARM64_FTR_END, }; static const struct arm64_ftr_bits ftr_id_dfr0[] = { /* [31:28] TraceFilt */ S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0xf), /* PerfMon */ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0), ARM64_FTR_END, }; static const struct arm64_ftr_bits ftr_zcr[] = { ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ZCR_ELx_LEN_SHIFT, ZCR_ELx_LEN_SIZE, 0), /* LEN */ ARM64_FTR_END, }; /* * Common ftr bits for a 32bit register with all hidden, strict * attributes, with 4bit feature fields and a default safe value of * 0. Covers the following 32bit registers: * id_isar[0-4], id_mmfr[1-3], id_pfr1, mvfr[0-1] */ static const struct arm64_ftr_bits ftr_generic_32bits[] = { ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0), ARM64_FTR_END, }; /* Table for a single 32bit feature value */ static const struct arm64_ftr_bits ftr_single32[] = { ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 0, 32, 0), ARM64_FTR_END, }; static const struct arm64_ftr_bits ftr_raz[] = { ARM64_FTR_END, }; #define ARM64_FTR_REG(id, table) { \ .sys_id = id, \ .reg = &(struct arm64_ftr_reg){ \ .name = #id, \ .ftr_bits = &((table)[0]), \ }} static const struct __ftr_reg_entry { u32 sys_id; struct arm64_ftr_reg *reg; } arm64_ftr_regs[] = { /* Op1 = 0, CRn = 0, CRm = 1 */ ARM64_FTR_REG(SYS_ID_PFR0_EL1, ftr_id_pfr0), ARM64_FTR_REG(SYS_ID_PFR1_EL1, ftr_generic_32bits), ARM64_FTR_REG(SYS_ID_DFR0_EL1, ftr_id_dfr0), ARM64_FTR_REG(SYS_ID_MMFR0_EL1, ftr_id_mmfr0), ARM64_FTR_REG(SYS_ID_MMFR1_EL1, ftr_generic_32bits), ARM64_FTR_REG(SYS_ID_MMFR2_EL1, ftr_generic_32bits), ARM64_FTR_REG(SYS_ID_MMFR3_EL1, ftr_generic_32bits), /* Op1 = 0, CRn = 0, CRm = 2 */ ARM64_FTR_REG(SYS_ID_ISAR0_EL1, ftr_generic_32bits), ARM64_FTR_REG(SYS_ID_ISAR1_EL1, ftr_generic_32bits), ARM64_FTR_REG(SYS_ID_ISAR2_EL1, ftr_generic_32bits), ARM64_FTR_REG(SYS_ID_ISAR3_EL1, ftr_generic_32bits), ARM64_FTR_REG(SYS_ID_ISAR4_EL1, ftr_generic_32bits), ARM64_FTR_REG(SYS_ID_ISAR5_EL1, ftr_id_isar5), ARM64_FTR_REG(SYS_ID_MMFR4_EL1, ftr_id_mmfr4), /* Op1 = 0, CRn = 0, CRm = 3 */ ARM64_FTR_REG(SYS_MVFR0_EL1, ftr_generic_32bits), ARM64_FTR_REG(SYS_MVFR1_EL1, ftr_generic_32bits), ARM64_FTR_REG(SYS_MVFR2_EL1, ftr_mvfr2), /* Op1 = 0, CRn = 0, CRm = 4 */ ARM64_FTR_REG(SYS_ID_AA64PFR0_EL1, ftr_id_aa64pfr0), ARM64_FTR_REG(SYS_ID_AA64PFR1_EL1, ftr_id_aa64pfr1), ARM64_FTR_REG(SYS_ID_AA64ZFR0_EL1, ftr_raz), /* Op1 = 0, CRn = 0, CRm = 5 */ ARM64_FTR_REG(SYS_ID_AA64DFR0_EL1, ftr_id_aa64dfr0), ARM64_FTR_REG(SYS_ID_AA64DFR1_EL1, ftr_raz), /* Op1 = 0, CRn = 0, CRm = 6 */ ARM64_FTR_REG(SYS_ID_AA64ISAR0_EL1, ftr_id_aa64isar0), ARM64_FTR_REG(SYS_ID_AA64ISAR1_EL1, ftr_id_aa64isar1), ARM64_FTR_REG(SYS_ID_AA64ISAR2_EL1, ftr_id_aa64isar2), /* Op1 = 0, CRn = 0, CRm = 7 */ ARM64_FTR_REG(SYS_ID_AA64MMFR0_EL1, ftr_id_aa64mmfr0), ARM64_FTR_REG(SYS_ID_AA64MMFR1_EL1, ftr_id_aa64mmfr1), ARM64_FTR_REG(SYS_ID_AA64MMFR2_EL1, ftr_id_aa64mmfr2), /* Op1 = 0, CRn = 1, CRm = 2 */ ARM64_FTR_REG(SYS_ZCR_EL1, ftr_zcr), /* Op1 = 3, CRn = 0, CRm = 0 */ { SYS_CTR_EL0, &arm64_ftr_reg_ctrel0 }, ARM64_FTR_REG(SYS_DCZID_EL0, ftr_dczid), /* Op1 = 3, CRn = 14, CRm = 0 */ ARM64_FTR_REG(SYS_CNTFRQ_EL0, ftr_single32), }; static int search_cmp_ftr_reg(const void *id, const void *regp) { return (int)(unsigned long)id - (int)((const struct __ftr_reg_entry *)regp)->sys_id; } /* * get_arm64_ftr_reg - Lookup a feature register entry using its * sys_reg() encoding. With the array arm64_ftr_regs sorted in the * ascending order of sys_id , we use binary search to find a matching * entry. * * returns - Upon success, matching ftr_reg entry for id. * - NULL on failure. It is upto the caller to decide * the impact of a failure. */ static struct arm64_ftr_reg *get_arm64_ftr_reg(u32 sys_id) { const struct __ftr_reg_entry *ret; ret = bsearch((const void *)(unsigned long)sys_id, arm64_ftr_regs, ARRAY_SIZE(arm64_ftr_regs), sizeof(arm64_ftr_regs[0]), search_cmp_ftr_reg); if (ret) return ret->reg; return NULL; } static u64 arm64_ftr_set_value(const struct arm64_ftr_bits *ftrp, s64 reg, s64 ftr_val) { u64 mask = arm64_ftr_mask(ftrp); reg &= ~mask; reg |= (ftr_val << ftrp->shift) & mask; return reg; } static s64 arm64_ftr_safe_value(const struct arm64_ftr_bits *ftrp, s64 new, s64 cur) { s64 ret = 0; switch (ftrp->type) { case FTR_EXACT: ret = ftrp->safe_val; break; case FTR_LOWER_SAFE: ret = new < cur ? new : cur; break; case FTR_HIGHER_OR_ZERO_SAFE: if (!cur || !new) break; /* Fallthrough */ case FTR_HIGHER_SAFE: ret = new > cur ? new : cur; break; default: BUG(); } return ret; } static void __init sort_ftr_regs(void) { int i; /* Check that the array is sorted so that we can do the binary search */ for (i = 1; i < ARRAY_SIZE(arm64_ftr_regs); i++) BUG_ON(arm64_ftr_regs[i].sys_id < arm64_ftr_regs[i - 1].sys_id); } /* * Initialise the CPU feature register from Boot CPU values. * Also initiliases the strict_mask for the register. * Any bits that are not covered by an arm64_ftr_bits entry are considered * RES0 for the system-wide value, and must strictly match. */ static void __init init_cpu_ftr_reg(u32 sys_reg, u64 new) { u64 val = 0; u64 strict_mask = ~0x0ULL; u64 user_mask = 0; u64 valid_mask = 0; const struct arm64_ftr_bits *ftrp; struct arm64_ftr_reg *reg = get_arm64_ftr_reg(sys_reg); BUG_ON(!reg); for (ftrp = reg->ftr_bits; ftrp->width; ftrp++) { u64 ftr_mask = arm64_ftr_mask(ftrp); s64 ftr_new = arm64_ftr_value(ftrp, new); val = arm64_ftr_set_value(ftrp, val, ftr_new); valid_mask |= ftr_mask; if (!ftrp->strict) strict_mask &= ~ftr_mask; if (ftrp->visible) user_mask |= ftr_mask; else reg->user_val = arm64_ftr_set_value(ftrp, reg->user_val, ftrp->safe_val); } val &= valid_mask; reg->sys_val = val; reg->strict_mask = strict_mask; reg->user_mask = user_mask; } extern const struct arm64_cpu_capabilities arm64_errata[]; static void __init setup_boot_cpu_capabilities(void); void __init init_cpu_features(struct cpuinfo_arm64 *info) { /* Before we start using the tables, make sure it is sorted */ sort_ftr_regs(); init_cpu_ftr_reg(SYS_CTR_EL0, info->reg_ctr); init_cpu_ftr_reg(SYS_DCZID_EL0, info->reg_dczid); init_cpu_ftr_reg(SYS_CNTFRQ_EL0, info->reg_cntfrq); init_cpu_ftr_reg(SYS_ID_AA64DFR0_EL1, info->reg_id_aa64dfr0); init_cpu_ftr_reg(SYS_ID_AA64DFR1_EL1, info->reg_id_aa64dfr1); init_cpu_ftr_reg(SYS_ID_AA64ISAR0_EL1, info->reg_id_aa64isar0); init_cpu_ftr_reg(SYS_ID_AA64ISAR1_EL1, info->reg_id_aa64isar1); init_cpu_ftr_reg(SYS_ID_AA64ISAR2_EL1, info->reg_id_aa64isar2); init_cpu_ftr_reg(SYS_ID_AA64MMFR0_EL1, info->reg_id_aa64mmfr0); init_cpu_ftr_reg(SYS_ID_AA64MMFR1_EL1, info->reg_id_aa64mmfr1); init_cpu_ftr_reg(SYS_ID_AA64MMFR2_EL1, info->reg_id_aa64mmfr2); init_cpu_ftr_reg(SYS_ID_AA64PFR0_EL1, info->reg_id_aa64pfr0); init_cpu_ftr_reg(SYS_ID_AA64PFR1_EL1, info->reg_id_aa64pfr1); init_cpu_ftr_reg(SYS_ID_AA64ZFR0_EL1, info->reg_id_aa64zfr0); if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) { init_cpu_ftr_reg(SYS_ID_DFR0_EL1, info->reg_id_dfr0); init_cpu_ftr_reg(SYS_ID_ISAR0_EL1, info->reg_id_isar0); init_cpu_ftr_reg(SYS_ID_ISAR1_EL1, info->reg_id_isar1); init_cpu_ftr_reg(SYS_ID_ISAR2_EL1, info->reg_id_isar2); init_cpu_ftr_reg(SYS_ID_ISAR3_EL1, info->reg_id_isar3); init_cpu_ftr_reg(SYS_ID_ISAR4_EL1, info->reg_id_isar4); init_cpu_ftr_reg(SYS_ID_ISAR5_EL1, info->reg_id_isar5); init_cpu_ftr_reg(SYS_ID_MMFR0_EL1, info->reg_id_mmfr0); init_cpu_ftr_reg(SYS_ID_MMFR1_EL1, info->reg_id_mmfr1); init_cpu_ftr_reg(SYS_ID_MMFR2_EL1, info->reg_id_mmfr2); init_cpu_ftr_reg(SYS_ID_MMFR3_EL1, info->reg_id_mmfr3); init_cpu_ftr_reg(SYS_ID_PFR0_EL1, info->reg_id_pfr0); init_cpu_ftr_reg(SYS_ID_PFR1_EL1, info->reg_id_pfr1); init_cpu_ftr_reg(SYS_MVFR0_EL1, info->reg_mvfr0); init_cpu_ftr_reg(SYS_MVFR1_EL1, info->reg_mvfr1); init_cpu_ftr_reg(SYS_MVFR2_EL1, info->reg_mvfr2); } if (id_aa64pfr0_sve(info->reg_id_aa64pfr0)) { init_cpu_ftr_reg(SYS_ZCR_EL1, info->reg_zcr); sve_init_vq_map(); } /* * Detect and enable early CPU capabilities based on the boot CPU, * after we have initialised the CPU feature infrastructure. */ setup_boot_cpu_capabilities(); } static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new) { const struct arm64_ftr_bits *ftrp; for (ftrp = reg->ftr_bits; ftrp->width; ftrp++) { s64 ftr_cur = arm64_ftr_value(ftrp, reg->sys_val); s64 ftr_new = arm64_ftr_value(ftrp, new); if (ftr_cur == ftr_new) continue; /* Find a safe value */ ftr_new = arm64_ftr_safe_value(ftrp, ftr_new, ftr_cur); reg->sys_val = arm64_ftr_set_value(ftrp, reg->sys_val, ftr_new); } } static int check_update_ftr_reg(u32 sys_id, int cpu, u64 val, u64 boot) { struct arm64_ftr_reg *regp = get_arm64_ftr_reg(sys_id); BUG_ON(!regp); update_cpu_ftr_reg(regp, val); if ((boot & regp->strict_mask) == (val & regp->strict_mask)) return 0; pr_warn("SANITY CHECK: Unexpected variation in %s. Boot CPU: %#016llx, CPU%d: %#016llx\n", regp->name, boot, cpu, val); return 1; } /* * Update system wide CPU feature registers with the values from a * non-boot CPU. Also performs SANITY checks to make sure that there * aren't any insane variations from that of the boot CPU. */ void update_cpu_features(int cpu, struct cpuinfo_arm64 *info, struct cpuinfo_arm64 *boot) { int taint = 0; /* * The kernel can handle differing I-cache policies, but otherwise * caches should look identical. Userspace JITs will make use of * *minLine. */ taint |= check_update_ftr_reg(SYS_CTR_EL0, cpu, info->reg_ctr, boot->reg_ctr); /* * Userspace may perform DC ZVA instructions. Mismatched block sizes * could result in too much or too little memory being zeroed if a * process is preempted and migrated between CPUs. */ taint |= check_update_ftr_reg(SYS_DCZID_EL0, cpu, info->reg_dczid, boot->reg_dczid); /* If different, timekeeping will be broken (especially with KVM) */ taint |= check_update_ftr_reg(SYS_CNTFRQ_EL0, cpu, info->reg_cntfrq, boot->reg_cntfrq); /* * The kernel uses self-hosted debug features and expects CPUs to * support identical debug features. We presently need CTX_CMPs, WRPs, * and BRPs to be identical. * ID_AA64DFR1 is currently RES0. */ taint |= check_update_ftr_reg(SYS_ID_AA64DFR0_EL1, cpu, info->reg_id_aa64dfr0, boot->reg_id_aa64dfr0); taint |= check_update_ftr_reg(SYS_ID_AA64DFR1_EL1, cpu, info->reg_id_aa64dfr1, boot->reg_id_aa64dfr1); /* * Even in big.LITTLE, processors should be identical instruction-set * wise. */ taint |= check_update_ftr_reg(SYS_ID_AA64ISAR0_EL1, cpu, info->reg_id_aa64isar0, boot->reg_id_aa64isar0); taint |= check_update_ftr_reg(SYS_ID_AA64ISAR1_EL1, cpu, info->reg_id_aa64isar1, boot->reg_id_aa64isar1); taint |= check_update_ftr_reg(SYS_ID_AA64ISAR2_EL1, cpu, info->reg_id_aa64isar2, boot->reg_id_aa64isar2); /* * Differing PARange support is fine as long as all peripherals and * memory are mapped within the minimum PARange of all CPUs. * Linux should not care about secure memory. */ taint |= check_update_ftr_reg(SYS_ID_AA64MMFR0_EL1, cpu, info->reg_id_aa64mmfr0, boot->reg_id_aa64mmfr0); taint |= check_update_ftr_reg(SYS_ID_AA64MMFR1_EL1, cpu, info->reg_id_aa64mmfr1, boot->reg_id_aa64mmfr1); taint |= check_update_ftr_reg(SYS_ID_AA64MMFR2_EL1, cpu, info->reg_id_aa64mmfr2, boot->reg_id_aa64mmfr2); taint |= check_update_ftr_reg(SYS_ID_AA64PFR0_EL1, cpu, info->reg_id_aa64pfr0, boot->reg_id_aa64pfr0); taint |= check_update_ftr_reg(SYS_ID_AA64PFR1_EL1, cpu, info->reg_id_aa64pfr1, boot->reg_id_aa64pfr1); taint |= check_update_ftr_reg(SYS_ID_AA64ZFR0_EL1, cpu, info->reg_id_aa64zfr0, boot->reg_id_aa64zfr0); /* * If we have AArch32, we care about 32-bit features for compat. * If the system doesn't support AArch32, don't update them. */ if (id_aa64pfr0_32bit_el0(read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1)) && id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) { taint |= check_update_ftr_reg(SYS_ID_DFR0_EL1, cpu, info->reg_id_dfr0, boot->reg_id_dfr0); taint |= check_update_ftr_reg(SYS_ID_ISAR0_EL1, cpu, info->reg_id_isar0, boot->reg_id_isar0); taint |= check_update_ftr_reg(SYS_ID_ISAR1_EL1, cpu, info->reg_id_isar1, boot->reg_id_isar1); taint |= check_update_ftr_reg(SYS_ID_ISAR2_EL1, cpu, info->reg_id_isar2, boot->reg_id_isar2); taint |= check_update_ftr_reg(SYS_ID_ISAR3_EL1, cpu, info->reg_id_isar3, boot->reg_id_isar3); taint |= check_update_ftr_reg(SYS_ID_ISAR4_EL1, cpu, info->reg_id_isar4, boot->reg_id_isar4); taint |= check_update_ftr_reg(SYS_ID_ISAR5_EL1, cpu, info->reg_id_isar5, boot->reg_id_isar5); /* * Regardless of the value of the AuxReg field, the AIFSR, ADFSR, and * ACTLR formats could differ across CPUs and therefore would have to * be trapped for virtualization anyway. */ taint |= check_update_ftr_reg(SYS_ID_MMFR0_EL1, cpu, info->reg_id_mmfr0, boot->reg_id_mmfr0); taint |= check_update_ftr_reg(SYS_ID_MMFR1_EL1, cpu, info->reg_id_mmfr1, boot->reg_id_mmfr1); taint |= check_update_ftr_reg(SYS_ID_MMFR2_EL1, cpu, info->reg_id_mmfr2, boot->reg_id_mmfr2); taint |= check_update_ftr_reg(SYS_ID_MMFR3_EL1, cpu, info->reg_id_mmfr3, boot->reg_id_mmfr3); taint |= check_update_ftr_reg(SYS_ID_PFR0_EL1, cpu, info->reg_id_pfr0, boot->reg_id_pfr0); taint |= check_update_ftr_reg(SYS_ID_PFR1_EL1, cpu, info->reg_id_pfr1, boot->reg_id_pfr1); taint |= check_update_ftr_reg(SYS_MVFR0_EL1, cpu, info->reg_mvfr0, boot->reg_mvfr0); taint |= check_update_ftr_reg(SYS_MVFR1_EL1, cpu, info->reg_mvfr1, boot->reg_mvfr1); taint |= check_update_ftr_reg(SYS_MVFR2_EL1, cpu, info->reg_mvfr2, boot->reg_mvfr2); } if (id_aa64pfr0_sve(info->reg_id_aa64pfr0)) { taint |= check_update_ftr_reg(SYS_ZCR_EL1, cpu, info->reg_zcr, boot->reg_zcr); /* Probe vector lengths, unless we already gave up on SVE */ if (id_aa64pfr0_sve(read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1)) && !sys_caps_initialised) sve_update_vq_map(); } /* * Mismatched CPU features are a recipe for disaster. Don't even * pretend to support them. */ if (taint) { pr_warn_once("Unsupported CPU feature variation detected.\n"); add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK); } } u64 read_sanitised_ftr_reg(u32 id) { struct arm64_ftr_reg *regp = get_arm64_ftr_reg(id); /* We shouldn't get a request for an unsupported register */ BUG_ON(!regp); return regp->sys_val; } #define read_sysreg_case(r) \ case r: return read_sysreg_s(r) /* * __read_sysreg_by_encoding() - Used by a STARTING cpu before cpuinfo is populated. * Read the system register on the current CPU */ static u64 __read_sysreg_by_encoding(u32 sys_id) { switch (sys_id) { read_sysreg_case(SYS_ID_PFR0_EL1); read_sysreg_case(SYS_ID_PFR1_EL1); read_sysreg_case(SYS_ID_DFR0_EL1); read_sysreg_case(SYS_ID_MMFR0_EL1); read_sysreg_case(SYS_ID_MMFR1_EL1); read_sysreg_case(SYS_ID_MMFR2_EL1); read_sysreg_case(SYS_ID_MMFR3_EL1); read_sysreg_case(SYS_ID_ISAR0_EL1); read_sysreg_case(SYS_ID_ISAR1_EL1); read_sysreg_case(SYS_ID_ISAR2_EL1); read_sysreg_case(SYS_ID_ISAR3_EL1); read_sysreg_case(SYS_ID_ISAR4_EL1); read_sysreg_case(SYS_ID_ISAR5_EL1); read_sysreg_case(SYS_MVFR0_EL1); read_sysreg_case(SYS_MVFR1_EL1); read_sysreg_case(SYS_MVFR2_EL1); read_sysreg_case(SYS_ID_AA64PFR0_EL1); read_sysreg_case(SYS_ID_AA64PFR1_EL1); read_sysreg_case(SYS_ID_AA64DFR0_EL1); read_sysreg_case(SYS_ID_AA64DFR1_EL1); read_sysreg_case(SYS_ID_AA64MMFR0_EL1); read_sysreg_case(SYS_ID_AA64MMFR1_EL1); read_sysreg_case(SYS_ID_AA64MMFR2_EL1); read_sysreg_case(SYS_ID_AA64ISAR0_EL1); read_sysreg_case(SYS_ID_AA64ISAR1_EL1); read_sysreg_case(SYS_ID_AA64ISAR2_EL1); read_sysreg_case(SYS_CNTFRQ_EL0); read_sysreg_case(SYS_CTR_EL0); read_sysreg_case(SYS_DCZID_EL0); default: BUG(); return 0; } } #include static bool feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry) { int val = cpuid_feature_extract_field(reg, entry->field_pos, entry->sign); return val >= entry->min_field_value; } static bool has_cpuid_feature(const struct arm64_cpu_capabilities *entry, int scope) { u64 val; WARN_ON(scope == SCOPE_LOCAL_CPU && preemptible()); if (scope == SCOPE_SYSTEM) val = read_sanitised_ftr_reg(entry->sys_reg); else val = __read_sysreg_by_encoding(entry->sys_reg); return feature_matches(val, entry); } static bool has_useable_gicv3_cpuif(const struct arm64_cpu_capabilities *entry, int scope) { bool has_sre; if (!has_cpuid_feature(entry, scope)) return false; has_sre = gic_enable_sre(); if (!has_sre) pr_warn_once("%s present but disabled by higher exception level\n", entry->desc); return has_sre; } static bool has_no_hw_prefetch(const struct arm64_cpu_capabilities *entry, int __unused) { u32 midr = read_cpuid_id(); /* Cavium ThunderX pass 1.x and 2.x */ return midr_is_cpu_model_range(midr, MIDR_THUNDERX, MIDR_CPU_VAR_REV(0, 0), MIDR_CPU_VAR_REV(1, MIDR_REVISION_MASK)); } static bool has_no_fpsimd(const struct arm64_cpu_capabilities *entry, int __unused) { u64 pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1); return cpuid_feature_extract_signed_field(pfr0, ID_AA64PFR0_FP_SHIFT) < 0; } static bool has_cache_idc(const struct arm64_cpu_capabilities *entry, int scope) { u64 ctr; if (scope == SCOPE_SYSTEM) ctr = arm64_ftr_reg_ctrel0.sys_val; else ctr = read_cpuid_cachetype(); return ctr & BIT(CTR_IDC_SHIFT); } static bool has_cache_dic(const struct arm64_cpu_capabilities *entry, int scope) { u64 ctr; if (scope == SCOPE_SYSTEM) ctr = arm64_ftr_reg_ctrel0.sys_val; else ctr = read_cpuid_cachetype(); return ctr & BIT(CTR_DIC_SHIFT); } static bool __meltdown_safe = true; static int __kpti_forced; /* 0: not forced, >0: forced on, <0: forced off */ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry, int scope) { /* List of CPUs that are not vulnerable and don't need KPTI */ static const struct midr_range kpti_safe_list[] = { MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2), MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN), MIDR_ALL_VERSIONS(MIDR_CORTEX_A35), MIDR_ALL_VERSIONS(MIDR_CORTEX_A53), MIDR_ALL_VERSIONS(MIDR_CORTEX_A55), MIDR_ALL_VERSIONS(MIDR_CORTEX_A57), MIDR_ALL_VERSIONS(MIDR_CORTEX_A72), MIDR_ALL_VERSIONS(MIDR_CORTEX_A73), MIDR_ALL_VERSIONS(MIDR_HISI_TSV110), { /* sentinel */ } }; char const *str = "kpti command line option"; bool meltdown_safe; meltdown_safe = is_midr_in_range_list(read_cpuid_id(), kpti_safe_list); /* Defer to CPU feature registers */ if (has_cpuid_feature(entry, scope)) meltdown_safe = true; if (!meltdown_safe) __meltdown_safe = false; /* * For reasons that aren't entirely clear, enabling KPTI on Cavium * ThunderX leads to apparent I-cache corruption of kernel text, which * ends as well as you might imagine. Don't even try. */ if (cpus_have_const_cap(ARM64_WORKAROUND_CAVIUM_27456)) { str = "ARM64_WORKAROUND_CAVIUM_27456"; __kpti_forced = -1; } /* Useful for KASLR robustness */ if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && kaslr_offset() > 0) { if (!__kpti_forced) { str = "KASLR"; __kpti_forced = 1; } } if (cpu_mitigations_off() && !__kpti_forced) { str = "mitigations=off"; __kpti_forced = -1; } if (!IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0)) { pr_info_once("kernel page table isolation disabled by kernel configuration\n"); return false; } /* Forced? */ if (__kpti_forced) { pr_info_once("kernel page table isolation forced %s by %s\n", __kpti_forced > 0 ? "ON" : "OFF", str); return __kpti_forced > 0; } return !meltdown_safe; } #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 static void kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused) { typedef void (kpti_remap_fn)(int, int, phys_addr_t); extern kpti_remap_fn idmap_kpti_install_ng_mappings; kpti_remap_fn *remap_fn; static bool kpti_applied = false; int cpu = smp_processor_id(); if (__this_cpu_read(this_cpu_vector) == vectors) { const char *v = arm64_get_bp_hardening_vector(EL1_VECTOR_KPTI); __this_cpu_write(this_cpu_vector, v); } if (kpti_applied) return; remap_fn = (void *)__pa_symbol(idmap_kpti_install_ng_mappings); cpu_install_idmap(); remap_fn(cpu, num_online_cpus(), __pa_symbol(swapper_pg_dir)); cpu_uninstall_idmap(); if (!cpu) kpti_applied = true; return; } #else static void kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused) { } #endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */ static int __init parse_kpti(char *str) { bool enabled; int ret = strtobool(str, &enabled); if (ret) return ret; __kpti_forced = enabled ? 1 : -1; return 0; } early_param("kpti", parse_kpti); #ifdef CONFIG_ARM64_HW_AFDBM static inline void __cpu_enable_hw_dbm(void) { u64 tcr = read_sysreg(tcr_el1) | TCR_HD; write_sysreg(tcr, tcr_el1); isb(); } static bool cpu_has_broken_dbm(void) { /* List of CPUs which have broken DBM support. */ static const struct midr_range cpus[] = { #ifdef CONFIG_ARM64_ERRATUM_1024718 MIDR_ALL_VERSIONS(MIDR_CORTEX_A55), #endif {}, }; return is_midr_in_range_list(read_cpuid_id(), cpus); } static bool cpu_can_use_dbm(const struct arm64_cpu_capabilities *cap) { return has_cpuid_feature(cap, SCOPE_LOCAL_CPU) && !cpu_has_broken_dbm(); } static void cpu_enable_hw_dbm(struct arm64_cpu_capabilities const *cap) { if (cpu_can_use_dbm(cap)) __cpu_enable_hw_dbm(); } static bool has_hw_dbm(const struct arm64_cpu_capabilities *cap, int __unused) { static bool detected = false; /* * DBM is a non-conflicting feature. i.e, the kernel can safely * run a mix of CPUs with and without the feature. So, we * unconditionally enable the capability to allow any late CPU * to use the feature. We only enable the control bits on the * CPU, if it actually supports. * * We have to make sure we print the "feature" detection only * when at least one CPU actually uses it. So check if this CPU * can actually use it and print the message exactly once. * * This is safe as all CPUs (including secondary CPUs - due to the * LOCAL_CPU scope - and the hotplugged CPUs - via verification) * goes through the "matches" check exactly once. Also if a CPU * matches the criteria, it is guaranteed that the CPU will turn * the DBM on, as the capability is unconditionally enabled. */ if (!detected && cpu_can_use_dbm(cap)) { detected = true; pr_info("detected: Hardware dirty bit management\n"); } return true; } #endif #ifdef CONFIG_ARM64_VHE static bool runs_at_el2(const struct arm64_cpu_capabilities *entry, int __unused) { return is_kernel_in_hyp_mode(); } static void cpu_copy_el2regs(const struct arm64_cpu_capabilities *__unused) { /* * Copy register values that aren't redirected by hardware. * * Before code patching, we only set tpidr_el1, all CPUs need to copy * this value to tpidr_el2 before we patch the code. Once we've done * that, freshly-onlined CPUs will set tpidr_el2, so we don't need to * do anything here. */ if (!alternatives_applied) write_sysreg(read_sysreg(tpidr_el1), tpidr_el2); } #endif static void cpu_has_fwb(const struct arm64_cpu_capabilities *__unused) { u64 val = read_sysreg_s(SYS_CLIDR_EL1); /* Check that CLIDR_EL1.LOU{U,IS} are both 0 */ WARN_ON(val & (7 << 27 | 7 << 21)); } #ifdef CONFIG_ARM64_SSBD static int ssbs_emulation_handler(struct pt_regs *regs, u32 instr) { if (user_mode(regs)) return 1; if (instr & BIT(CRm_shift)) regs->pstate |= PSR_SSBS_BIT; else regs->pstate &= ~PSR_SSBS_BIT; arm64_skip_faulting_instruction(regs, 4); return 0; } static struct undef_hook ssbs_emulation_hook = { .instr_mask = ~(1U << CRm_shift), .instr_val = 0xd500001f | REG_PSTATE_SSBS_IMM, .fn = ssbs_emulation_handler, }; static void cpu_enable_ssbs(const struct arm64_cpu_capabilities *__unused) { static bool undef_hook_registered = false; static DEFINE_SPINLOCK(hook_lock); spin_lock(&hook_lock); if (!undef_hook_registered) { register_undef_hook(&ssbs_emulation_hook); undef_hook_registered = true; } spin_unlock(&hook_lock); if (arm64_get_ssbd_state() == ARM64_SSBD_FORCE_DISABLE) { sysreg_clear_set(sctlr_el1, 0, SCTLR_ELx_DSSBS); arm64_set_ssbd_mitigation(false); } else { arm64_set_ssbd_mitigation(true); } } #endif /* CONFIG_ARM64_SSBD */ static void elf_hwcap_fixup(void) { #ifdef CONFIG_ARM64_ERRATUM_1742098 if (cpus_have_const_cap(ARM64_WORKAROUND_1742098)) compat_elf_hwcap2 &= ~COMPAT_HWCAP2_AES; #endif /* ARM64_ERRATUM_1742098 */ } static const struct arm64_cpu_capabilities arm64_features[] = { { .desc = "GIC system register CPU interface", .capability = ARM64_HAS_SYSREG_GIC_CPUIF, .type = ARM64_CPUCAP_SYSTEM_FEATURE, .matches = has_useable_gicv3_cpuif, .sys_reg = SYS_ID_AA64PFR0_EL1, .field_pos = ID_AA64PFR0_GIC_SHIFT, .sign = FTR_UNSIGNED, .min_field_value = 1, }, #ifdef CONFIG_ARM64_PAN { .desc = "Privileged Access Never", .capability = ARM64_HAS_PAN, .type = ARM64_CPUCAP_SYSTEM_FEATURE, .matches = has_cpuid_feature, .sys_reg = SYS_ID_AA64MMFR1_EL1, .field_pos = ID_AA64MMFR1_PAN_SHIFT, .sign = FTR_UNSIGNED, .min_field_value = 1, .cpu_enable = cpu_enable_pan, }, #endif /* CONFIG_ARM64_PAN */ #if defined(CONFIG_AS_LSE) && defined(CONFIG_ARM64_LSE_ATOMICS) { .desc = "LSE atomic instructions", .capability = ARM64_HAS_LSE_ATOMICS, .type = ARM64_CPUCAP_SYSTEM_FEATURE, .matches = has_cpuid_feature, .sys_reg = SYS_ID_AA64ISAR0_EL1, .field_pos = ID_AA64ISAR0_ATOMICS_SHIFT, .sign = FTR_UNSIGNED, .min_field_value = 2, }, #endif /* CONFIG_AS_LSE && CONFIG_ARM64_LSE_ATOMICS */ { .desc = "Software prefetching using PRFM", .capability = ARM64_HAS_NO_HW_PREFETCH, .type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE, .matches = has_no_hw_prefetch, }, #ifdef CONFIG_ARM64_UAO { .desc = "User Access Override", .capability = ARM64_HAS_UAO, .type = ARM64_CPUCAP_SYSTEM_FEATURE, .matches = has_cpuid_feature, .sys_reg = SYS_ID_AA64MMFR2_EL1, .field_pos = ID_AA64MMFR2_UAO_SHIFT, .min_field_value = 1, /* * We rely on stop_machine() calling uao_thread_switch() to set * UAO immediately after patching. */ }, #endif /* CONFIG_ARM64_UAO */ #ifdef CONFIG_ARM64_PAN { .capability = ARM64_ALT_PAN_NOT_UAO, .type = ARM64_CPUCAP_SYSTEM_FEATURE, .matches = cpufeature_pan_not_uao, }, #endif /* CONFIG_ARM64_PAN */ #ifdef CONFIG_ARM64_VHE { .desc = "Virtualization Host Extensions", .capability = ARM64_HAS_VIRT_HOST_EXTN, .type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE, .matches = runs_at_el2, .cpu_enable = cpu_copy_el2regs, }, #endif /* CONFIG_ARM64_VHE */ { .desc = "32-bit EL0 Support", .capability = ARM64_HAS_32BIT_EL0, .type = ARM64_CPUCAP_SYSTEM_FEATURE, .matches = has_cpuid_feature, .sys_reg = SYS_ID_AA64PFR0_EL1, .sign = FTR_UNSIGNED, .field_pos = ID_AA64PFR0_EL0_SHIFT, .min_field_value = ID_AA64PFR0_EL0_32BIT_64BIT, }, { .desc = "Kernel page table isolation (KPTI)", .capability = ARM64_UNMAP_KERNEL_AT_EL0, .type = ARM64_CPUCAP_BOOT_RESTRICTED_CPU_LOCAL_FEATURE, /* * The ID feature fields below are used to indicate that * the CPU doesn't need KPTI. See unmap_kernel_at_el0 for * more details. */ .sys_reg = SYS_ID_AA64PFR0_EL1, .field_pos = ID_AA64PFR0_CSV3_SHIFT, .min_field_value = 1, .matches = unmap_kernel_at_el0, .cpu_enable = kpti_install_ng_mappings, }, { /* FP/SIMD is not implemented */ .capability = ARM64_HAS_NO_FPSIMD, .type = ARM64_CPUCAP_BOOT_RESTRICTED_CPU_LOCAL_FEATURE, .min_field_value = 0, .matches = has_no_fpsimd, }, #ifdef CONFIG_ARM64_PMEM { .desc = "Data cache clean to Point of Persistence", .capability = ARM64_HAS_DCPOP, .type = ARM64_CPUCAP_SYSTEM_FEATURE, .matches = has_cpuid_feature, .sys_reg = SYS_ID_AA64ISAR1_EL1, .field_pos = ID_AA64ISAR1_DPB_SHIFT, .min_field_value = 1, }, #endif #ifdef CONFIG_ARM64_SVE { .desc = "Scalable Vector Extension", .type = ARM64_CPUCAP_SYSTEM_FEATURE, .capability = ARM64_SVE, .sys_reg = SYS_ID_AA64PFR0_EL1, .sign = FTR_UNSIGNED, .field_pos = ID_AA64PFR0_SVE_SHIFT, .min_field_value = ID_AA64PFR0_SVE, .matches = has_cpuid_feature, .cpu_enable = sve_kernel_enable, }, #endif /* CONFIG_ARM64_SVE */ #ifdef CONFIG_ARM64_RAS_EXTN { .desc = "RAS Extension Support", .capability = ARM64_HAS_RAS_EXTN, .type = ARM64_CPUCAP_SYSTEM_FEATURE, .matches = has_cpuid_feature, .sys_reg = SYS_ID_AA64PFR0_EL1, .sign = FTR_UNSIGNED, .field_pos = ID_AA64PFR0_RAS_SHIFT, .min_field_value = ID_AA64PFR0_RAS_V1, .cpu_enable = cpu_clear_disr, }, #endif /* CONFIG_ARM64_RAS_EXTN */ { .desc = "Data cache clean to the PoU not required for I/D coherence", .capability = ARM64_HAS_CACHE_IDC, .type = ARM64_CPUCAP_SYSTEM_FEATURE, .matches = has_cache_idc, }, { .desc = "Instruction cache invalidation not required for I/D coherence", .capability = ARM64_HAS_CACHE_DIC, .type = ARM64_CPUCAP_SYSTEM_FEATURE, .matches = has_cache_dic, }, { .desc = "Stage-2 Force Write-Back", .type = ARM64_CPUCAP_SYSTEM_FEATURE, .capability = ARM64_HAS_STAGE2_FWB, .sys_reg = SYS_ID_AA64MMFR2_EL1, .sign = FTR_UNSIGNED, .field_pos = ID_AA64MMFR2_FWB_SHIFT, .min_field_value = 1, .matches = has_cpuid_feature, .cpu_enable = cpu_has_fwb, }, #ifdef CONFIG_ARM64_HW_AFDBM { /* * Since we turn this on always, we don't want the user to * think that the feature is available when it may not be. * So hide the description. * * .desc = "Hardware pagetable Dirty Bit Management", * */ .type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE, .capability = ARM64_HW_DBM, .sys_reg = SYS_ID_AA64MMFR1_EL1, .sign = FTR_UNSIGNED, .field_pos = ID_AA64MMFR1_HADBS_SHIFT, .min_field_value = 2, .matches = has_hw_dbm, .cpu_enable = cpu_enable_hw_dbm, }, #endif #ifdef CONFIG_ARM64_SSBD { .desc = "Speculative Store Bypassing Safe (SSBS)", .capability = ARM64_SSBS, .type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE, .matches = has_cpuid_feature, .sys_reg = SYS_ID_AA64PFR1_EL1, .field_pos = ID_AA64PFR1_SSBS_SHIFT, .sign = FTR_UNSIGNED, .min_field_value = ID_AA64PFR1_SSBS_PSTATE_ONLY, .cpu_enable = cpu_enable_ssbs, }, #endif {}, }; #define HWCAP_CPUID_MATCH(reg, field, s, min_value) \ .matches = has_cpuid_feature, \ .sys_reg = reg, \ .field_pos = field, \ .sign = s, \ .min_field_value = min_value, \ #define __HWCAP_CAP(name, cap_type, cap) \ .desc = name, \ .type = ARM64_CPUCAP_SYSTEM_FEATURE, \ .hwcap_type = cap_type, \ .hwcap = cap, \ #define HWCAP_CAP(reg, field, s, min_value, cap_type, cap) \ { \ __HWCAP_CAP(#cap, cap_type, cap) \ HWCAP_CPUID_MATCH(reg, field, s, min_value) \ } #define HWCAP_CAP_MATCH(match, cap_type, cap) \ { \ __HWCAP_CAP(#cap, cap_type, cap) \ .matches = match, \ } static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = { HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, HWCAP_PMULL), HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_AES), HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA1_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_SHA1), HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA2_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_SHA2), HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA2_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, HWCAP_SHA512), HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_CRC32_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_CRC32), HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_ATOMICS_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, HWCAP_ATOMICS), HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_RDM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_ASIMDRDM), HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA3_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_SHA3), HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SM3_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_SM3), HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SM4_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_SM4), HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_DP_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_ASIMDDP), HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_FHM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_ASIMDFHM), HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_TS_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_FLAGM), HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, FTR_SIGNED, 0, CAP_HWCAP, HWCAP_FP), HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, HWCAP_FPHP), HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, FTR_SIGNED, 0, CAP_HWCAP, HWCAP_ASIMD), HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, HWCAP_ASIMDHP), HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_DIT_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, HWCAP_DIT), HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DPB_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_DCPOP), HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_JSCVT_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_JSCVT), HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_FCMA_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_FCMA), HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_LRCPC), HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, HWCAP_ILRCPC), HWCAP_CAP(SYS_ID_AA64MMFR2_EL1, ID_AA64MMFR2_AT_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_USCAT), #ifdef CONFIG_ARM64_SVE HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_SVE_SHIFT, FTR_UNSIGNED, ID_AA64PFR0_SVE, CAP_HWCAP, HWCAP_SVE), #endif HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_SSBS_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_SSBS_PSTATE_INSNS, CAP_HWCAP, HWCAP_SSBS), {}, }; #ifdef CONFIG_COMPAT static bool compat_has_neon(const struct arm64_cpu_capabilities *cap, int scope) { /* * Check that all of MVFR1_EL1.{SIMDSP, SIMDInt, SIMDLS} are available, * in line with that of arm32 as in vfp_init(). We make sure that the * check is future proof, by making sure value is non-zero. */ u32 mvfr1; WARN_ON(scope == SCOPE_LOCAL_CPU && preemptible()); if (scope == SCOPE_SYSTEM) mvfr1 = read_sanitised_ftr_reg(SYS_MVFR1_EL1); else mvfr1 = read_sysreg_s(SYS_MVFR1_EL1); return cpuid_feature_extract_unsigned_field(mvfr1, MVFR1_SIMDSP_SHIFT) && cpuid_feature_extract_unsigned_field(mvfr1, MVFR1_SIMDINT_SHIFT) && cpuid_feature_extract_unsigned_field(mvfr1, MVFR1_SIMDLS_SHIFT); } #endif static const struct arm64_cpu_capabilities compat_elf_hwcaps[] = { #ifdef CONFIG_COMPAT HWCAP_CAP_MATCH(compat_has_neon, CAP_COMPAT_HWCAP, COMPAT_HWCAP_NEON), HWCAP_CAP(SYS_MVFR1_EL1, MVFR1_SIMDFMAC_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP, COMPAT_HWCAP_VFPv4), /* Arm v8 mandates MVFR0.FPDP == {0, 2}. So, piggy back on this for the presence of VFP support */ HWCAP_CAP(SYS_MVFR0_EL1, MVFR0_FPDP_SHIFT, FTR_UNSIGNED, 2, CAP_COMPAT_HWCAP, COMPAT_HWCAP_VFP), HWCAP_CAP(SYS_MVFR0_EL1, MVFR0_FPDP_SHIFT, FTR_UNSIGNED, 2, CAP_COMPAT_HWCAP, COMPAT_HWCAP_VFPv3), HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, FTR_UNSIGNED, 2, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_PMULL), HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_AES), HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA1_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA1), HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA2_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA2), HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_CRC32_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_CRC32), #endif {}, }; static void __init cap_set_elf_hwcap(const struct arm64_cpu_capabilities *cap) { switch (cap->hwcap_type) { case CAP_HWCAP: elf_hwcap |= cap->hwcap; break; #ifdef CONFIG_COMPAT case CAP_COMPAT_HWCAP: compat_elf_hwcap |= (u32)cap->hwcap; break; case CAP_COMPAT_HWCAP2: compat_elf_hwcap2 |= (u32)cap->hwcap; break; #endif default: WARN_ON(1); break; } } /* Check if we have a particular HWCAP enabled */ static bool cpus_have_elf_hwcap(const struct arm64_cpu_capabilities *cap) { bool rc; switch (cap->hwcap_type) { case CAP_HWCAP: rc = (elf_hwcap & cap->hwcap) != 0; break; #ifdef CONFIG_COMPAT case CAP_COMPAT_HWCAP: rc = (compat_elf_hwcap & (u32)cap->hwcap) != 0; break; case CAP_COMPAT_HWCAP2: rc = (compat_elf_hwcap2 & (u32)cap->hwcap) != 0; break; #endif default: WARN_ON(1); rc = false; } return rc; } static void __init setup_elf_hwcaps(const struct arm64_cpu_capabilities *hwcaps) { /* We support emulation of accesses to CPU ID feature registers */ elf_hwcap |= HWCAP_CPUID; for (; hwcaps->matches; hwcaps++) if (hwcaps->matches(hwcaps, cpucap_default_scope(hwcaps))) cap_set_elf_hwcap(hwcaps); } /* * Check if the current CPU has a given feature capability. * Should be called from non-preemptible context. */ static bool __this_cpu_has_cap(const struct arm64_cpu_capabilities *cap_array, unsigned int cap) { const struct arm64_cpu_capabilities *caps; if (WARN_ON(preemptible())) return false; for (caps = cap_array; caps->matches; caps++) if (caps->capability == cap) return caps->matches(caps, SCOPE_LOCAL_CPU); return false; } static void __update_cpu_capabilities(const struct arm64_cpu_capabilities *caps, u16 scope_mask, const char *info) { scope_mask &= ARM64_CPUCAP_SCOPE_MASK; for (; caps->matches; caps++) { if (!(caps->type & scope_mask) || !caps->matches(caps, cpucap_default_scope(caps))) continue; if (!cpus_have_cap(caps->capability) && caps->desc) pr_info("%s %s\n", info, caps->desc); cpus_set_cap(caps->capability); } } static void update_cpu_capabilities(u16 scope_mask) { __update_cpu_capabilities(arm64_errata, scope_mask, "enabling workaround for"); __update_cpu_capabilities(arm64_features, scope_mask, "detected:"); } static int __enable_cpu_capability(void *arg) { const struct arm64_cpu_capabilities *cap = arg; cap->cpu_enable(cap); return 0; } /* * Run through the enabled capabilities and enable() it on all active * CPUs */ static void __init __enable_cpu_capabilities(const struct arm64_cpu_capabilities *caps, u16 scope_mask) { scope_mask &= ARM64_CPUCAP_SCOPE_MASK; for (; caps->matches; caps++) { unsigned int num = caps->capability; if (!(caps->type & scope_mask) || !cpus_have_cap(num)) continue; /* Ensure cpus_have_const_cap(num) works */ static_branch_enable(&cpu_hwcap_keys[num]); if (caps->cpu_enable) { /* * Capabilities with SCOPE_BOOT_CPU scope are finalised * before any secondary CPU boots. Thus, each secondary * will enable the capability as appropriate via * check_local_cpu_capabilities(). The only exception is * the boot CPU, for which the capability must be * enabled here. This approach avoids costly * stop_machine() calls for this case. * * Otherwise, use stop_machine() as it schedules the * work allowing us to modify PSTATE, instead of * on_each_cpu() which uses an IPI, giving us a PSTATE * that disappears when we return. */ if (scope_mask & SCOPE_BOOT_CPU) caps->cpu_enable(caps); else stop_machine(__enable_cpu_capability, (void *)caps, cpu_online_mask); } } } static void __init enable_cpu_capabilities(u16 scope_mask) { __enable_cpu_capabilities(arm64_errata, scope_mask); __enable_cpu_capabilities(arm64_features, scope_mask); } /* * Run through the list of capabilities to check for conflicts. * If the system has already detected a capability, take necessary * action on this CPU. * * Returns "false" on conflicts. */ static bool __verify_local_cpu_caps(const struct arm64_cpu_capabilities *caps, u16 scope_mask) { bool cpu_has_cap, system_has_cap; scope_mask &= ARM64_CPUCAP_SCOPE_MASK; for (; caps->matches; caps++) { if (!(caps->type & scope_mask)) continue; cpu_has_cap = caps->matches(caps, SCOPE_LOCAL_CPU); system_has_cap = cpus_have_cap(caps->capability); if (system_has_cap) { /* * Check if the new CPU misses an advertised feature, * which is not safe to miss. */ if (!cpu_has_cap && !cpucap_late_cpu_optional(caps)) break; /* * We have to issue cpu_enable() irrespective of * whether the CPU has it or not, as it is enabeld * system wide. It is upto the call back to take * appropriate action on this CPU. */ if (caps->cpu_enable) caps->cpu_enable(caps); } else { /* * Check if the CPU has this capability if it isn't * safe to have when the system doesn't. */ if (cpu_has_cap && !cpucap_late_cpu_permitted(caps)) break; } } if (caps->matches) { pr_crit("CPU%d: Detected conflict for capability %d (%s), System: %d, CPU: %d\n", smp_processor_id(), caps->capability, caps->desc, system_has_cap, cpu_has_cap); return false; } return true; } static bool verify_local_cpu_caps(u16 scope_mask) { return __verify_local_cpu_caps(arm64_errata, scope_mask) && __verify_local_cpu_caps(arm64_features, scope_mask); } /* * Check for CPU features that are used in early boot * based on the Boot CPU value. */ static void check_early_cpu_features(void) { verify_cpu_asid_bits(); /* * Early features are used by the kernel already. If there * is a conflict, we cannot proceed further. */ if (!verify_local_cpu_caps(SCOPE_BOOT_CPU)) cpu_panic_kernel(); } static void verify_local_elf_hwcaps(const struct arm64_cpu_capabilities *caps) { for (; caps->matches; caps++) if (cpus_have_elf_hwcap(caps) && !caps->matches(caps, SCOPE_LOCAL_CPU)) { pr_crit("CPU%d: missing HWCAP: %s\n", smp_processor_id(), caps->desc); cpu_die_early(); } } static void verify_sve_features(void) { u64 safe_zcr = read_sanitised_ftr_reg(SYS_ZCR_EL1); u64 zcr = read_zcr_features(); unsigned int safe_len = safe_zcr & ZCR_ELx_LEN_MASK; unsigned int len = zcr & ZCR_ELx_LEN_MASK; if (len < safe_len || sve_verify_vq_map()) { pr_crit("CPU%d: SVE: required vector length(s) missing\n", smp_processor_id()); cpu_die_early(); } /* Add checks on other ZCR bits here if necessary */ } /* * Run through the enabled system capabilities and enable() it on this CPU. * The capabilities were decided based on the available CPUs at the boot time. * Any new CPU should match the system wide status of the capability. If the * new CPU doesn't have a capability which the system now has enabled, we * cannot do anything to fix it up and could cause unexpected failures. So * we park the CPU. */ static void verify_local_cpu_capabilities(void) { /* * The capabilities with SCOPE_BOOT_CPU are checked from * check_early_cpu_features(), as they need to be verified * on all secondary CPUs. */ if (!verify_local_cpu_caps(SCOPE_ALL & ~SCOPE_BOOT_CPU)) cpu_die_early(); verify_local_elf_hwcaps(arm64_elf_hwcaps); if (system_supports_32bit_el0()) verify_local_elf_hwcaps(compat_elf_hwcaps); if (system_supports_sve()) verify_sve_features(); } void check_local_cpu_capabilities(void) { /* * All secondary CPUs should conform to the early CPU features * in use by the kernel based on boot CPU. */ check_early_cpu_features(); /* * If we haven't finalised the system capabilities, this CPU gets * a chance to update the errata work arounds and local features. * Otherwise, this CPU should verify that it has all the system * advertised capabilities. */ if (!sys_caps_initialised) update_cpu_capabilities(SCOPE_LOCAL_CPU); else verify_local_cpu_capabilities(); } static void __init setup_boot_cpu_capabilities(void) { /* Detect capabilities with either SCOPE_BOOT_CPU or SCOPE_LOCAL_CPU */ update_cpu_capabilities(SCOPE_BOOT_CPU | SCOPE_LOCAL_CPU); /* Enable the SCOPE_BOOT_CPU capabilities alone right away */ enable_cpu_capabilities(SCOPE_BOOT_CPU); } DEFINE_STATIC_KEY_FALSE(arm64_const_caps_ready); EXPORT_SYMBOL(arm64_const_caps_ready); static void __init mark_const_caps_ready(void) { static_branch_enable(&arm64_const_caps_ready); } extern const struct arm64_cpu_capabilities arm64_errata[]; bool this_cpu_has_cap(unsigned int cap) { return (__this_cpu_has_cap(arm64_features, cap) || __this_cpu_has_cap(arm64_errata, cap)); } static void __init setup_system_capabilities(void) { /* * We have finalised the system-wide safe feature * registers, finalise the capabilities that depend * on it. Also enable all the available capabilities, * that are not enabled already. */ update_cpu_capabilities(SCOPE_SYSTEM); enable_cpu_capabilities(SCOPE_ALL & ~SCOPE_BOOT_CPU); } void __init setup_cpu_features(void) { u32 cwg; setup_system_capabilities(); mark_const_caps_ready(); setup_elf_hwcaps(arm64_elf_hwcaps); if (system_supports_32bit_el0()) { setup_elf_hwcaps(compat_elf_hwcaps); elf_hwcap_fixup(); } if (system_uses_ttbr0_pan()) pr_info("emulated: Privileged Access Never (PAN) using TTBR0_EL1 switching\n"); sve_setup(); minsigstksz_setup(); /* Advertise that we have computed the system capabilities */ set_sys_caps_initialised(); /* * Check for sane CTR_EL0.CWG value. */ cwg = cache_type_cwg(); if (!cwg) pr_warn("No Cache Writeback Granule information, assuming %d\n", ARCH_DMA_MINALIGN); } static bool __maybe_unused cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry, int __unused) { return (cpus_have_const_cap(ARM64_HAS_PAN) && !cpus_have_const_cap(ARM64_HAS_UAO)); } /* * We emulate only the following system register space. * Op0 = 0x3, CRn = 0x0, Op1 = 0x0, CRm = [0, 4 - 7] * See Table C5-6 System instruction encodings for System register accesses, * ARMv8 ARM(ARM DDI 0487A.f) for more details. */ static inline bool __attribute_const__ is_emulated(u32 id) { return (sys_reg_Op0(id) == 0x3 && sys_reg_CRn(id) == 0x0 && sys_reg_Op1(id) == 0x0 && (sys_reg_CRm(id) == 0 || ((sys_reg_CRm(id) >= 4) && (sys_reg_CRm(id) <= 7)))); } /* * With CRm == 0, reg should be one of : * MIDR_EL1, MPIDR_EL1 or REVIDR_EL1. */ static inline int emulate_id_reg(u32 id, u64 *valp) { switch (id) { case SYS_MIDR_EL1: *valp = read_cpuid_id(); break; case SYS_MPIDR_EL1: *valp = SYS_MPIDR_SAFE_VAL; break; case SYS_REVIDR_EL1: /* IMPLEMENTATION DEFINED values are emulated with 0 */ *valp = 0; break; default: return -EINVAL; } return 0; } static int emulate_sys_reg(u32 id, u64 *valp) { struct arm64_ftr_reg *regp; if (!is_emulated(id)) return -EINVAL; if (sys_reg_CRm(id) == 0) return emulate_id_reg(id, valp); regp = get_arm64_ftr_reg(id); if (regp) *valp = arm64_ftr_reg_user_value(regp); else /* * The untracked registers are either IMPLEMENTATION DEFINED * (e.g, ID_AFR0_EL1) or reserved RAZ. */ *valp = 0; return 0; } static int emulate_mrs(struct pt_regs *regs, u32 insn) { int rc; u32 sys_reg, dst; u64 val; /* * sys_reg values are defined as used in mrs/msr instruction. * shift the imm value to get the encoding. */ sys_reg = (u32)aarch64_insn_decode_immediate(AARCH64_INSN_IMM_16, insn) << 5; rc = emulate_sys_reg(sys_reg, &val); if (!rc) { dst = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RT, insn); pt_regs_write_reg(regs, dst, val); arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE); } return rc; } static struct undef_hook mrs_hook = { .instr_mask = 0xfff00000, .instr_val = 0xd5300000, .pstate_mask = PSR_AA32_MODE_MASK, .pstate_val = PSR_MODE_EL0t, .fn = emulate_mrs, }; static int __init enable_mrs_emulation(void) { register_undef_hook(&mrs_hook); return 0; } core_initcall(enable_mrs_emulation); void cpu_clear_disr(const struct arm64_cpu_capabilities *__unused) { /* Firmware may have left a deferred SError in this register. */ write_sysreg_s(0, SYS_DISR_EL1); } ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf) { if (__meltdown_safe) return sprintf(buf, "Not affected\n"); if (arm64_kernel_unmapped_at_el0()) return sprintf(buf, "Mitigation: PTI\n"); return sprintf(buf, "Vulnerable\n"); }