On Fri, Jun 16, 2017 at 02:23:36PM +0200, Mike Belopuhov wrote:
> On Fri, Jun 16, 2017 at 16:31 +1000, Jonathan Matthew wrote:
> > Index: arch/i386/include/cpufunc.h
> > ===================================================================
> > RCS file: /cvs/src/sys/arch/i386/include/cpufunc.h,v
> > retrieving revision 1.25
> > diff -u -p -u -p -r1.25 cpufunc.h
> > --- arch/i386/include/cpufunc.h 27 May 2017 12:21:50 -0000 1.25
> > +++ arch/i386/include/cpufunc.h 16 Jun 2017 06:07:16 -0000
> > @@ -217,6 +217,15 @@ mfence(void)
> > __asm volatile("mfence" : : : "memory");
> > }
> >
> > +static __inline u_int64_t
> > +rdtsc(void)
> > +{
> > + uint32_t hi, lo;
> > +
> > + __asm volatile("rdtsc" : "=d" (hi), "=a" (lo));
> > + return (((uint64_t)hi << 32) | (uint64_t) lo);
> > +}
> > +
> > static __inline void
> > wrmsr(u_int msr, u_int64_t newval)
> > {
>
> I think it's OK to get this chunk in. amd64 has got this already.
>
Perhaps make it __asm volatile ("rdtsc" : "=A" (v)); like the pctr.h version?
That's also what the gcc example uses for rdtsc in
https://gcc.gnu.org/onlinedocs/gcc/Machine-Constraints.html#Machine-Constraints
I guess the chance of something pretending to be a 486 without TSC attaching
pvbus is slim.
