diff options
Diffstat (limited to 'arch/x86/kernel/process.c')
| -rw-r--r-- | arch/x86/kernel/process.c | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index dac41a0072ea..ff9b80a0e3e3 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -759,15 +759,26 @@ bool xen_set_default_idle(void) } #endif +struct cpumask cpus_stop_mask; + void __noreturn stop_this_cpu(void *dummy) { + struct cpuinfo_x86 *c = this_cpu_ptr(&cpu_info); + unsigned int cpu = smp_processor_id(); + local_irq_disable(); + /* - * Remove this CPU: + * Remove this CPU from the online mask and disable it + * unconditionally. This might be redundant in case that the reboot + * vector was handled late and stop_other_cpus() sent an NMI. + * + * According to SDM and APM NMIs can be accepted even after soft + * disabling the local APIC. */ - set_cpu_online(smp_processor_id(), false); + set_cpu_online(cpu, false); disable_local_APIC(); - mcheck_cpu_clear(this_cpu_ptr(&cpu_info)); + mcheck_cpu_clear(c); /* * Use wbinvd on processors that support SME. This provides support @@ -781,8 +792,17 @@ void __noreturn stop_this_cpu(void *dummy) * Test the CPUID bit directly because the machine might've cleared * X86_FEATURE_SME due to cmdline options. */ - if (cpuid_eax(0x8000001f) & BIT(0)) + if (c->extended_cpuid_level >= 0x8000001f && (cpuid_eax(0x8000001f) & BIT(0))) native_wbinvd(); + + /* + * This brings a cache line back and dirties it, but + * native_stop_other_cpus() will overwrite cpus_stop_mask after it + * observed that all CPUs reported stop. This write will invalidate + * the related cache line on this CPU. + */ + cpumask_clear_cpu(cpu, &cpus_stop_mask); + for (;;) { /* * Use native_halt() so that memory contents don't change |