From: Eugene Surovegin <ebs@ebshome.net>
To: Marcelo Tosatti <marcelo.tosatti@cyclades.com>
Cc: linuxppc-embedded@ozlabs.org
Subject: Re: [PATCH] 8xx: add cpm_get_cpmp()
Date: Sun, 7 Aug 2005 12:18:29 -0700 [thread overview]
Message-ID: <20050807191829.GA5375@gate.ebshome.net> (raw)
In-Reply-To: <20050807155731.GA2715@dmt.cnet>
On Sun, Aug 07, 2005 at 12:57:31PM -0300, Marcelo Tosatti wrote:
> On Sun, Aug 07, 2005 at 12:44:32PM -0300, Aristeu Sergio Rozanski Filho wrote:
> > > It depends how you define the semantics of this function call.
> > > Can you call it any (and all of the) time you need it, or does it
> > > actually perform an ioremap() and you only want to call it
> > > once?
> > what about don't cache it and call ioremap() from driver? (I guess
> > ioremap() already check if an area is already mapped, no?)
>
> Yep, ioremap() should be doing virtual address caching already, no?
In general, ioremap() doesn't do any caching currently. Some subarchs
do some limited caching, e.g. if BATs (classic PPC) or CAMs (e500) are
available and were used previously for ioremap() mappings.
Some time ago I made a trivial ioremap cache patch (useful on 4xx,
which doesn't have BATs nor CAMs), although it wass really a hack and
it was never merged :).
--
Eugene
next prev parent reply other threads:[~2005-08-07 19:18 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-08-06 18:03 [PATCH] 8xx: add cpm_get_cpmp() Aristeu Sergio Rozanski Filho
2005-08-06 23:27 ` Marcelo Tosatti
2005-08-06 23:42 ` Aristeu Sergio Rozanski Filho
2005-08-07 0:33 ` Marcelo Tosatti
2005-08-07 3:36 ` Dan Malek
2005-08-07 2:40 ` Dan Malek
2005-08-07 4:31 ` Marcelo Tosatti
2005-08-07 15:39 ` Dan Malek
2005-08-07 15:44 ` Aristeu Sergio Rozanski Filho
2005-08-07 15:57 ` Marcelo Tosatti
2005-08-07 19:18 ` Eugene Surovegin [this message]
2005-08-07 17:25 ` Dan Malek
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