Subject: Re: [PATCH] powerpc/mm: Fix 40x and 8xx vs. _PAGE_SPECIAL

From: Benjamin Herrenschmidt <[email-masked]>
Date: Thu, 24 Sep 2009 12:53:35 +1000

On Wed, 2009-09-23 at 19:38 -0700, Rex Feany wrote:
> Thus spake Benjamin Herrenschmidt ([email-masked]):
> 
> > Hrm. This is really strange...
> 
> Is this a problem? in pte-8xx.h you added:
> 
> +#define _PAGE_SPECIAL  0x0008  /* SW entry, forced to 0 by the TLB miss */
> 
> but there is already this:
> 
> #define _PAGE_EXEC      0x0008  /* software: i-cache coherency required */

Ohhh... you aren't using upstream ! That explains :-)

I removed _PAGE_EXEC from 8xx (since it doesn't use it for anything)
recently.

I think the best option is to go for Bernhard's patch for "stable" and
my patch for upstream, so that "stable" gets the bug fix without the
feature of _PAGE_SPECIAL and upstream gets it both.

Cheers,
Ben.