On Fri, Sep 21, 2018 at 2:21 PM Matthew Whitehead <[email protected]> wrote: > > Presently we check for cpuid to be enabled first. If it is not already > enabled, then we next call identify_cpu_without_cpuid() and clear > X86_FEATURE_CPUID. > > Unfortunately, identify_cpu_without_cpuid() is the function where cpuid > becomes _enabled_ on Cyrix 6x86/6x86L cpus. So we must reverse the > calling sequence so that cpuid is first enabled, and then check a second > time to see if the feature has now been activated. > > Reviewed-by: Andy Lutomirski <[email protected]>
How about Suggested-and-reviewed-by: Andy Lutomirski <[email protected]> instead? (No need to resubmit for just that. Ingo or Thomas, if you like these, can you just make that substitution?) > Signed-off-by: Matthew Whitehead <[email protected]> > --- > arch/x86/kernel/cpu/common.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c > index eb4cb3efd20e..60c7c5ce7e55 100644 > --- a/arch/x86/kernel/cpu/common.c > +++ b/arch/x86/kernel/cpu/common.c > @@ -1040,6 +1040,9 @@ static void __init early_identify_cpu(struct > cpuinfo_x86 *c) > memset(&c->x86_capability, 0, sizeof c->x86_capability); > c->extended_cpuid_level = 0; > > + if (!have_cpuid_p()) > + identify_cpu_without_cpuid(c); > + > /* cyrix could have cpuid enabled via c_identify()*/ > if (have_cpuid_p()) { > cpu_detect(c); > @@ -1057,7 +1060,6 @@ static void __init early_identify_cpu(struct > cpuinfo_x86 *c) > if (this_cpu->c_bsp_init) > this_cpu->c_bsp_init(c); > } else { > - identify_cpu_without_cpuid(c); > setup_clear_cpu_cap(X86_FEATURE_CPUID); > } > > -- > 2.16.4 > -- Andy Lutomirski AMA Capital Management, LLC
