diff options
Diffstat (limited to 'arch/arm64/kernel/cpufeature.c')
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 195 |
1 files changed, 173 insertions, 22 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index e238b7932096d..af50064dea51a 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -20,6 +20,7 @@ #include <linux/bsearch.h> #include <linux/cpumask.h> +#include <linux/crash_dump.h> #include <linux/sort.h> #include <linux/stop_machine.h> #include <linux/types.h> @@ -117,6 +118,7 @@ EXPORT_SYMBOL(cpu_hwcap_keys); static bool __maybe_unused cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry, int __unused); +static void cpu_enable_cnp(struct arm64_cpu_capabilities const *cap); /* * NOTE: Any changes to the visibility of features should be kept in @@ -164,6 +166,11 @@ static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = { 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[] = { S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN4_SHIFT, 4, ID_AA64MMFR0_TGRAN4_NI), S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN64_SHIFT, 4, ID_AA64MMFR0_TGRAN64_NI), @@ -371,7 +378,7 @@ static const struct __ftr_reg_entry { /* Op1 = 0, CRn = 0, CRm = 4 */ ARM64_FTR_REG(SYS_ID_AA64PFR0_EL1, ftr_id_aa64pfr0), - ARM64_FTR_REG(SYS_ID_AA64PFR1_EL1, ftr_raz), + 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 */ @@ -657,7 +664,6 @@ void update_cpu_features(int cpu, /* * EL3 is not our concern. - * ID_AA64PFR1 is currently RES0. */ taint |= check_update_ftr_reg(SYS_ID_AA64PFR0_EL1, cpu, info->reg_id_aa64pfr0, boot->reg_id_aa64pfr0); @@ -848,15 +854,55 @@ static bool has_no_fpsimd(const struct arm64_cpu_capabilities *entry, int __unus } static bool has_cache_idc(const struct arm64_cpu_capabilities *entry, - int __unused) + int scope) { - return read_sanitised_ftr_reg(SYS_CTR_EL0) & BIT(CTR_IDC_SHIFT); + u64 ctr; + + if (scope == SCOPE_SYSTEM) + ctr = arm64_ftr_reg_ctrel0.sys_val; + else + ctr = read_cpuid_effective_cachetype(); + + return ctr & BIT(CTR_IDC_SHIFT); +} + +static void cpu_emulate_effective_ctr(const struct arm64_cpu_capabilities *__unused) +{ + /* + * If the CPU exposes raw CTR_EL0.IDC = 0, while effectively + * CTR_EL0.IDC = 1 (from CLIDR values), we need to trap accesses + * to the CTR_EL0 on this CPU and emulate it with the real/safe + * value. + */ + if (!(read_cpuid_cachetype() & BIT(CTR_IDC_SHIFT))) + sysreg_clear_set(sctlr_el1, SCTLR_EL1_UCT, 0); } static bool has_cache_dic(const struct arm64_cpu_capabilities *entry, - int __unused) + int scope) { - return read_sanitised_ftr_reg(SYS_CTR_EL0) & BIT(CTR_DIC_SHIFT); + 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 __maybe_unused +has_useable_cnp(const struct arm64_cpu_capabilities *entry, int scope) +{ + /* + * Kdump isn't guaranteed to power-off all secondary CPUs, CNP + * may share TLB entries with a CPU stuck in the crashed + * kernel. + */ + if (is_kdump_kernel()) + return false; + + return has_cpuid_feature(entry, scope); } #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 @@ -1035,6 +1081,70 @@ static void cpu_has_fwb(const struct arm64_cpu_capabilities *__unused) 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(PSTATE_Imm_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 << PSTATE_Imm_shift), + .instr_val = 0xd500401f | PSTATE_SSBS, + .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 */ + +#ifdef CONFIG_ARM64_PAN +static void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused) +{ + /* + * We modify PSTATE. This won't work from irq context as the PSTATE + * is discarded once we return from the exception. + */ + WARN_ON_ONCE(in_interrupt()); + + sysreg_clear_set(sctlr_el1, SCTLR_EL1_SPAN, 0); + asm(SET_PSTATE_PAN(1)); +} +#endif /* CONFIG_ARM64_PAN */ + +#ifdef CONFIG_ARM64_RAS_EXTN +static 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); +} +#endif /* CONFIG_ARM64_RAS_EXTN */ + static const struct arm64_cpu_capabilities arm64_features[] = { { .desc = "GIC system register CPU interface", @@ -1184,6 +1294,7 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .capability = ARM64_HAS_CACHE_IDC, .type = ARM64_CPUCAP_SYSTEM_FEATURE, .matches = has_cache_idc, + .cpu_enable = cpu_emulate_effective_ctr, }, { .desc = "Instruction cache invalidation not required for I/D coherence", @@ -1222,6 +1333,41 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .cpu_enable = cpu_enable_hw_dbm, }, #endif +#ifdef CONFIG_ARM64_SSBD + { + .desc = "CRC32 instructions", + .capability = ARM64_HAS_CRC32, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .matches = has_cpuid_feature, + .sys_reg = SYS_ID_AA64ISAR0_EL1, + .field_pos = ID_AA64ISAR0_CRC32_SHIFT, + .min_field_value = 1, + }, + { + .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 +#ifdef CONFIG_ARM64_CNP + { + .desc = "Common not Private translations", + .capability = ARM64_HAS_CNP, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .matches = has_useable_cnp, + .sys_reg = SYS_ID_AA64MMFR2_EL1, + .sign = FTR_UNSIGNED, + .field_pos = ID_AA64MMFR2_CNP_SHIFT, + .min_field_value = 1, + .cpu_enable = cpu_enable_cnp, + }, +#endif {}, }; @@ -1267,6 +1413,7 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = { #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), {}, }; @@ -1658,6 +1805,11 @@ 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)); } +static void __maybe_unused cpu_enable_cnp(struct arm64_cpu_capabilities const *cap) +{ + cpu_replace_ttbr1(lm_alias(swapper_pg_dir)); +} + /* * We emulate only the following system register space. * Op0 = 0x3, CRn = 0x0, Op1 = 0x0, CRm = [0, 4 - 7] @@ -1719,27 +1871,32 @@ static int emulate_sys_reg(u32 id, u64 *valp) return 0; } -static int emulate_mrs(struct pt_regs *regs, u32 insn) +int do_emulate_mrs(struct pt_regs *regs, u32 sys_reg, u32 rt) { 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); + pt_regs_write_reg(regs, rt, val); arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE); } - return rc; } +static int emulate_mrs(struct pt_regs *regs, u32 insn) +{ + u32 sys_reg, rt; + + /* + * 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; + rt = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RT, insn); + return do_emulate_mrs(regs, sys_reg, rt); +} + static struct undef_hook mrs_hook = { .instr_mask = 0xfff00000, .instr_val = 0xd5300000, @@ -1755,9 +1912,3 @@ static int __init enable_mrs_emulation(void) } 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); -} |