Re: [PATCH] x86: Quark: Flush TLB via CR3 not CR4.PGE in setup_arch()

[Bryan O'Donoghue]

> > I'd have mentioned "erratum" there, otherwise people won't understand why
> > the PGE bit being set would be a problem in the first place.
> >
> > Something like:
> >
> > /*
> >   * Locate the page directory and flush the TLB.
> >   *
> >   * On Quark X1000 CPUs we still have the PGE bit incorrectly set
> >   * due to a processor erratum, so __flush_tlb_all() is not yet
> >   * doing what it says.  Fortunately we have a cr3 flush here,
> >   * which is what is needed in this processor to flush TLBs, so
> >   * there's no need to add a Quark X1000 quirk here.
> >   */
>
> Yeah.
>
> I'd also add the fact that it's an unintended erratum to the
> Quark quirk section of early_init_intel() as well.

OK.

How about.

/*
  * Locate the page directory and flush the TLB.
  *
  * On Quark X1000 CPUs we still have the PGE bit incorrectly set
  * due to a processor erratum, so __flush_tlb_all() is not yet
  * doing what it says.  Fortunately we have a cr3 flush here,
  * which is what is needed in this processor to flush TLBs, so
  * there's no need to add a Quark X1000 quirk here.
  *
  * early_init_intel will unset the X86_FEATURE_PGE flag later
  * and __flush_tlb_all() will flush via cr3
  */
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