diff options
Diffstat (limited to 'arch/arm64/kernel/cpufeature.c')
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 7566cad9fa1d..cdf1dca64133 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -19,13 +19,16 @@ #define pr_fmt(fmt) "CPU features: " fmt #include <linux/bsearch.h> +#include <linux/cpumask.h> #include <linux/sort.h> +#include <linux/stop_machine.h> #include <linux/types.h> #include <asm/cpu.h> #include <asm/cpufeature.h> #include <asm/cpu_ops.h> #include <asm/processor.h> #include <asm/sysreg.h> +#include <asm/virt.h> unsigned long elf_hwcap __read_mostly; EXPORT_SYMBOL_GPL(elf_hwcap); @@ -43,6 +46,7 @@ unsigned int compat_elf_hwcap2 __read_mostly; #endif DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS); +EXPORT_SYMBOL(cpu_hwcaps); #define __ARM64_FTR_BITS(SIGNED, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \ { \ @@ -646,6 +650,11 @@ static bool has_no_hw_prefetch(const struct arm64_cpu_capabilities *entry) return MIDR_IS_CPU_MODEL_RANGE(midr, MIDR_THUNDERX, rv_min, rv_max); } +static bool runs_at_el2(const struct arm64_cpu_capabilities *entry) +{ + return is_kernel_in_hyp_mode(); +} + static const struct arm64_cpu_capabilities arm64_features[] = { { .desc = "GIC system register CPU interface", @@ -698,6 +707,11 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .matches = cpufeature_pan_not_uao, }, #endif /* CONFIG_ARM64_PAN */ + { + .desc = "Virtualization Host Extensions", + .capability = ARM64_HAS_VIRT_HOST_EXTN, + .matches = runs_at_el2, + }, {}, }; @@ -812,7 +826,13 @@ enable_cpu_capabilities(const struct arm64_cpu_capabilities *caps) for (i = 0; caps[i].matches; i++) if (caps[i].enable && cpus_have_cap(caps[i].capability)) - on_each_cpu(caps[i].enable, NULL, true); + /* + * 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. + */ + stop_machine(caps[i].enable, NULL, cpu_online_mask); } #ifdef CONFIG_HOTPLUG_CPU |