how to check for "optional" ppc chip features (MSR_BE)

Benjamin Herrenschmidt benh at
Mon May 5 10:49:10 EST 2008

On Sun, 2008-05-04 at 16:12 -0700, Roland McGrath wrote:
> > Oh and classic pitfall: If you define a new feature bit, make sure
> > CPU_FTRS_POSSIBLE is updated to contain it in cputable.h
> Yeah, all that stuff I could figure out as needed.  What I really meant
> was, where is the big official table of which chips behave which ways that
> you base all code that on?

There isn't any ...

> Actually, I don't really care as long as you
> all are happy to be responsible for figuring out what matters.  With the
> patch I posted to use MSR_BE, I took Kumar Gala's word as gospel that all
> the chips on which we use MSR_SE also have MSR_BE.  If that's not right,
> then I hope you'd like to pick a feature bit, populate the tables, etc.,
> and fix the definition of arch_has_block_step() as appropriate.

I'll have to check with Paul, we'll scrub the IBM parts, and Kumar can
dbl check the "classic 32" FSL parts.


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