From: Suzuki K Poulose suzuki.poulose@arm.com
[ Upstream commit be5b299830c63ed76e0357473c4218c85fb388b3 ]
Add helpers for detecting an errata on list of midr ranges of affected CPUs, with the same work around.
Cc: Will Deacon will.deacon@arm.com Cc: Mark Rutland mark.rutland@arm.com Cc: Ard Biesheuvel ard.biesheuvel@linaro.org Reviewed-by: Dave Martin dave.martin@arm.com Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com Signed-off-by: Will Deacon will.deacon@arm.com [ardb: add Cortex-A35 to kpti_safe_list[] as well] Signed-off-by: Ard Biesheuvel ard.biesheuvel@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: James Morse james.morse@arm.com --- arch/arm64/include/asm/cpufeature.h | 1 + arch/arm64/include/asm/cputype.h | 9 +++++ arch/arm64/kernel/cpu_errata.c | 62 +++++++++++++++++------------ arch/arm64/kernel/cpufeature.c | 21 +++++----- 4 files changed, 58 insertions(+), 35 deletions(-)
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index f8646d7fae49..45206dd20ffd 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -233,6 +233,7 @@ struct arm64_cpu_capabilities { struct midr_range midr_range; };
+ const struct midr_range *midr_range_list; struct { /* Feature register checking */ u32 sys_reg; u8 field_pos; diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h index e76245ea6b60..61041e051acb 100644 --- a/arch/arm64/include/asm/cputype.h +++ b/arch/arm64/include/asm/cputype.h @@ -143,6 +143,15 @@ static inline bool is_midr_in_range(u32 midr, struct midr_range const *range) range->rv_min, range->rv_max); }
+static inline bool +is_midr_in_range_list(u32 midr, struct midr_range const *ranges) +{ + while (ranges->model) + if (is_midr_in_range(midr, ranges++)) + return true; + return false; +} + /* * The CPU ID never changes at run time, so we might as well tell the * compiler that it's constant. Use this function to read the CPU ID diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index e2630e88e8ad..69c3492cb063 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -33,6 +33,14 @@ is_affected_midr_range(const struct arm64_cpu_capabilities *entry, int scope) return is_midr_in_range(midr, &entry->midr_range); }
+static bool __maybe_unused +is_affected_midr_range_list(const struct arm64_cpu_capabilities *entry, + int scope) +{ + WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible()); + return is_midr_in_range_list(read_cpuid_id(), entry->midr_range_list); +} + static bool has_mismatched_cache_type(const struct arm64_cpu_capabilities *entry, int scope) @@ -383,6 +391,10 @@ static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry, .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, \ CAP_MIDR_RANGE(model, v_min, r_min, v_max, r_max)
+#define CAP_MIDR_RANGE_LIST(list) \ + .matches = is_affected_midr_range_list, \ + .midr_range_list = list + /* Errata affecting a range of revisions of given model variant */ #define ERRATA_MIDR_REV_RANGE(m, var, r_min, r_max) \ ERRATA_MIDR_RANGE(m, var, r_min, var, r_max) @@ -396,6 +408,29 @@ static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry, .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, \ CAP_MIDR_ALL_VERSIONS(model)
+/* Errata affecting a list of midr ranges, with same work around */ +#define ERRATA_MIDR_RANGE_LIST(midr_list) \ + .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, \ + CAP_MIDR_RANGE_LIST(midr_list) + +#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR + +/* + * List of CPUs where we need to issue a psci call to + * harden the branch predictor. + */ +static const struct midr_range arm64_bp_harden_smccc_cpus[] = { + MIDR_ALL_VERSIONS(MIDR_CORTEX_A57), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A72), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A73), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A75), + MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN), + MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2), + {}, +}; + +#endif + const struct arm64_cpu_capabilities arm64_errata[] = { #if defined(CONFIG_ARM64_ERRATUM_826319) || \ defined(CONFIG_ARM64_ERRATUM_827319) || \ @@ -486,32 +521,7 @@ const struct arm64_cpu_capabilities arm64_errata[] = { #ifdef CONFIG_HARDEN_BRANCH_PREDICTOR { .capability = ARM64_HARDEN_BRANCH_PREDICTOR, - ERRATA_MIDR_ALL_VERSIONS(MIDR_CORTEX_A57), - .cpu_enable = enable_smccc_arch_workaround_1, - }, - { - .capability = ARM64_HARDEN_BRANCH_PREDICTOR, - ERRATA_MIDR_ALL_VERSIONS(MIDR_CORTEX_A72), - .cpu_enable = enable_smccc_arch_workaround_1, - }, - { - .capability = ARM64_HARDEN_BRANCH_PREDICTOR, - ERRATA_MIDR_ALL_VERSIONS(MIDR_CORTEX_A73), - .cpu_enable = enable_smccc_arch_workaround_1, - }, - { - .capability = ARM64_HARDEN_BRANCH_PREDICTOR, - ERRATA_MIDR_ALL_VERSIONS(MIDR_CORTEX_A75), - .cpu_enable = enable_smccc_arch_workaround_1, - }, - { - .capability = ARM64_HARDEN_BRANCH_PREDICTOR, - ERRATA_MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN), - .cpu_enable = enable_smccc_arch_workaround_1, - }, - { - .capability = ARM64_HARDEN_BRANCH_PREDICTOR, - ERRATA_MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2), + ERRATA_MIDR_RANGE_LIST(arm64_bp_harden_smccc_cpus), .cpu_enable = enable_smccc_arch_workaround_1, }, #endif diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 51567cd83099..1b5afb80247d 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -767,6 +767,17 @@ 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 __unused) { + /* 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), + }; char const *str = "command line option"; u64 pfr0 = read_system_reg(SYS_ID_AA64PFR0_EL1);
@@ -792,16 +803,8 @@ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry, return true;
/* Don't force KPTI for CPUs that are not vulnerable */ - switch (read_cpuid_id() & MIDR_CPU_MODEL_MASK) { - case MIDR_CAVIUM_THUNDERX2: - case MIDR_BRCM_VULCAN: - case MIDR_CORTEX_A53: - case MIDR_CORTEX_A55: - case MIDR_CORTEX_A57: - case MIDR_CORTEX_A72: - case MIDR_CORTEX_A73: + if (is_midr_in_range_list(read_cpuid_id(), kpti_safe_list)) return false; - }
/* Defer to CPU feature registers */ return !cpuid_feature_extract_unsigned_field(pfr0,