diff options
Diffstat (limited to 'arch/arm64/kernel/cpufeature.c')
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index f15e2fb97011..237f8822a391 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 @@ -863,6 +865,20 @@ static bool has_cache_dic(const struct arm64_cpu_capabilities *entry, return read_sanitised_ftr_reg(SYS_CTR_EL0) & 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 static int __kpti_forced; /* 0: not forced, >0: forced on, <0: forced off */ @@ -1312,6 +1328,19 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .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 {}, }; @@ -1749,6 +1778,11 @@ 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] |