From: Arjan van de Ven <arjan@infradead.org>
To: Jes Sorensen <jes@trained-monkey.org>
Cc: Andrew Morton <akpm@osdl.org>,
linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [patch -mm series] ia64 specific /dev/mem handlers
Date: Tue, 22 Feb 2005 22:03:53 +0000 [thread overview]
Message-ID: <1109109833.6024.109.camel@laptopd505.fenrus.org> (raw)
In-Reply-To: <16923.193.128608.607599@jaguar.mkp.net>
On Tue, 2005-02-22 at 04:52 -0500, Jes Sorensen wrote:
> Hi,
>
> This patch introduces ia64 specific read/write handlers for /dev/mem
> access which is needed to avoid uncached pages to be accessed through
> the cached kernel window which can lead to random corruption. It also
> introduces a new page-flag PG_uncached which will be used to mark the
> uncached pages. I assume this may be useful to other architectures as
> well where the CPU may use speculative reads which conflict with
> uncached access. In addition I moved do_write_mem to be under
> ARCH_HAS_DEV_MEM as it's only ever used if that is defined.
>
> The patch is needed for the new ia64 special memory driver (mspec -
> former fetchop).
is there ANY valid reason to allow access to cached uses at all?
(eg kernel ram)
why not just disable any such ram access entirely...
next prev parent reply other threads:[~2005-02-22 22:03 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-02-22 9:52 [patch -mm series] ia64 specific /dev/mem handlers Jes Sorensen
2005-02-22 10:03 ` Andrew Morton
2005-02-22 12:08 ` Andi Kleen
2005-02-22 14:41 ` Jes Sorensen
2005-02-22 17:52 ` Matthew Wilcox
2005-02-22 19:25 ` Andrew Morton
2005-02-22 19:35 ` Dave Hansen
2005-02-22 21:38 ` Jes Sorensen
2005-02-23 0:48 ` Dave Hansen
2005-02-22 21:34 ` Jes Sorensen
2005-02-22 22:39 ` Jes Sorensen
2005-02-22 23:34 ` Andrew Morton
2005-02-23 10:01 ` Jes Sorensen
2005-02-23 22:34 ` Christoph Hellwig
2005-02-24 16:11 ` Jes Sorensen
2005-03-10 6:55 ` Andrew Morton
2005-03-10 13:49 ` Jes Sorensen
2005-02-22 18:05 ` Luck, Tony
2005-02-22 22:03 ` Arjan van de Ven [this message]
2005-02-22 22:30 ` Jes Sorensen
2005-02-22 22:42 ` Arjan van de Ven
2005-02-23 8:12 ` Jes Sorensen
2005-02-23 8:24 ` Arjan van de Ven
2005-03-03 11:37 ` Andrew Morton
2005-03-03 12:53 ` Jes Sorensen
2005-03-04 12:26 ` Jes Sorensen
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