From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3D08276D.3080502@embeddededge.com> Date: Thu, 13 Jun 2002 01:02:37 -0400 From: Dan Malek MIME-Version: 1.0 To: David Gibson Cc: linuxppc-embedded@lists.linuxppc.org, Paul Mackerras Subject: Re: get_pteptr() References: <20020613040345.GD4228@zax> Content-Type: text/plain; charset=us-ascii; format=flowed Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: David Gibson wrote: > get_pteptr() is used in exactly three places: > - in arch/ppc/8xx_io/commproc.c in the #else side of a #if 1, > i.e. not really used at all. That was one of my earliest cache management hacks, that predated iopa() and consistent_alloc(). You can get rid of it. > - in do_page_fault() [arch/ppc/mm/fault.c] for the handling of > page execute faults on 40x. It's use here is arguably incorrect if > large page pmds are introduced, although we won't ever get execute > faults on large pages, so it doesn't really matter. Hmmmm.....I was always hoping we could use "standard" VM functions to find and update PTEs, but I guess that isn't happening. I would suggest just placing a comment around this about the large pages and leave it. > But given that iopa() is pretty much the only user of this function > (do_page_fault() should be done slightly differently, I think), there > doesn't seem a lot of point. Why not just eliminate get_pteptr() and > walk the page tables explicitly in iopa(). I sometimes use get_pteptr() for debug. Make sure xmon doesn't use it for printing page table information. > [*] Well, apart from removing iopa() entirely, but that's another > flamewar^Wdiscussion. Just remove it for 4xx, or put an #ifdef in iopa() to do the arithmetic conversion. It's only used on 4xx and 8xx, and I would like to ensure the 8xx still works correctly before we nuke everything. I would just be a little careful to ensure you have run enough PCI cards to verify everything is OK. Thanks. -- Dan ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/