diff options
Diffstat (limited to 'arch/x86/kernel/process_64.c')
| -rw-r--r-- | arch/x86/kernel/process_64.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 4e65ae8a54bf..dbe0a846ec52 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -280,10 +280,19 @@ static void mwait_idle(void) } } + +static int mwait_usable(const struct cpuinfo_x86 *c) +{ + if (force_mwait) + return 1; + /* Any C1 states supported? */ + return c->cpuid_level >= 5 && ((cpuid_edx(5) >> 4) & 0xf) > 0; +} + void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c) { static int printed; - if (cpu_has(c, X86_FEATURE_MWAIT)) { + if (cpu_has(c, X86_FEATURE_MWAIT) && mwait_usable(c)) { /* * Skip, if setup has overridden idle. * One CPU supports mwait => All CPUs supports mwait |
