From: Scott Wood <scottwood@freescale•com>
To: leroy christophe <christophe.leroy@c-s•fr>
Cc: linuxppc-dev@lists•ozlabs.org, Paul Mackerras <paulus@samba•org>,
linux-kernel@vger•kernel.org
Subject: Re: [PATCH v2] powerpc 8xx: Loading kernels over 8Mbytes without CONFIG_PIN_TLB
Date: Tue, 17 Dec 2013 16:38:24 -0600 [thread overview]
Message-ID: <1387319904.10013.482.camel@snotra.buserror.net> (raw)
In-Reply-To: <52AFE70D.70407@c-s.fr>
On Tue, 2013-12-17 at 06:54 +0100, leroy christophe wrote:
> Le 16/12/2013 23:57, Scott Wood a écrit :
> > On Wed, 2013-12-11 at 00:36 +0100, leroy christophe wrote:
> >> Le 11/12/2013 00:18, Scott Wood a écrit :
> >>> There wasn't previously an ifdef specifically around the setting of
> >>> SPRN_MD_CTR. That's new. There was an ifdef around the entire block,
> >>> which has gone away because you are now trying to map more than 8M
> >>> regardless of CONFIG_PIN_TLB, but that has nothing to do with whether
> >>> there should be an ifdef around SPRN_MD_CTR.
> >>>
> >>>
> >> Euh, ok, but then we have to fix it in the whole function, not only in
> >> this block. Do you think it is worth doing it ?
> > Fix what in the whole function? I was asking what harm there would be
> > if you just remove all the CONFIG_PIN_TLB ifdefs except around the
> > actual RSV4I setting -- do we really care what value goes in MD_CTR for
> > the non-pinned case, as long as it's different for each entry?
> >
> >
> MD_CTR is decremented after each entry added.
> However, the function populates entry 28, then 29, then 30, then 31. At
> the end MD_CTR has then value 30, ready to overide entry 30 then 29 then
> 28 then 27 .....
>
> So I will remove all the CONFIG_PIN_TLB, but I'll also have to fix the
> value set in MD_CTR to start from 31, won't I ?
OK, so the answer is that we rely on autodecrement avoiding entries over
28 in the CONFIG_PIN_TLB case. Leave the ifdefs, then.
> Do you have any comment/recommendation on my tentative v3 patch where I
> have tried to implement based on the use of r7 as you recommended ?
I haven't reviewed it yet.
-Scott
prev parent reply other threads:[~2013-12-17 22:38 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-10 11:29 [PATCH v2] powerpc 8xx: Loading kernels over 8Mbytes without CONFIG_PIN_TLB Christophe Leroy
2013-12-10 22:24 ` Scott Wood
2013-12-10 23:05 ` leroy christophe
2013-12-10 23:18 ` Scott Wood
2013-12-10 23:36 ` leroy christophe
2013-12-16 22:57 ` Scott Wood
2013-12-17 5:54 ` leroy christophe
2013-12-17 22:38 ` Scott Wood [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1387319904.10013.482.camel@snotra.buserror.net \
--to=scottwood@freescale$(echo .)com \
--cc=christophe.leroy@c-s$(echo .)fr \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=linuxppc-dev@lists$(echo .)ozlabs.org \
--cc=paulus@samba$(echo .)org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox