From: Dan Malek <dan@mvista•com>
To: Matt Porter <mmporter@home•com>
Cc: Subodh Nijsure <SNijsure@SkyStream•com>,
linuxppc-embedded@lists•linuxppc.org
Subject: Re: How does one get physical address for iorempped window?
Date: Mon, 19 Feb 2001 12:59:10 -0500 [thread overview]
Message-ID: <3A915EEE.664737E1@mvista.com> (raw)
In-Reply-To: 20010218092828.A14685@cx258813-a.chnd1.az.home.com
Matt Porter wrote:
> Well, the base problem is that virt_to_*/*_to_virt were only ever
> intended to work on addresses mapped to system RAM.
I know.....But, even for someone like me that works with this
on a nearly daily basis it is sometimes confusing. It's truly
easy to have one function that can tell you virt/phys/virt mappings,
other OS implementations have done that for years. If you want
a "fast" RAM only mapping, use __pa()/__va(), they have been around
forever. The virt_to_*/*_to_virt functions _should_ have become
something more generic, but they are just yet another macro name
for doing the same thing. Now, we have gone of and created some pci_*
mapping functions, which are not at all useful for highly integrated
processors because their integrated features are not PCI devices.
Yet another set of functions for integrated processors? I don't think so.
I think that requiring knowledge of the object attributes for a VM or
physical space so you can call the proper mapping or other management
functions is just a poor design. If you know this information and
wish to take performance enhancement shortcuts, that's fine, but it
shouldn't be required.
I'm working on it........
-- Dan
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
next prev parent reply other threads:[~2001-02-19 17:59 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-02-15 17:58 How does one get physical address for iorempped window? Subodh Nijsure
2001-02-15 18:10 ` Dan Malek
2001-02-18 16:28 ` Matt Porter
2001-02-19 17:59 ` Dan Malek [this message]
-- strict thread matches above, loose matches on Subject: below --
2001-02-19 21:12 mod+linuxppc-embedded
2001-02-19 19:15 mod+linuxppc-embedded
2001-02-19 19:53 ` Dan Malek
2001-02-15 16:05 Subodh Nijsure
2001-02-15 17:03 ` Dan Malek
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