From: Mark Mokryn <mark@sangate.com>
To: linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: ioremap_nocache problem?
Date: Tue, 23 Jan 2001 12:30:00 +0200 [thread overview]
Message-ID: <3A6D5D28.C132D416@sangate.com> (raw)
ioremap_nocache does the following:
return __ioremap(offset, size, _PAGE_PCD);
However, in drivers/char/mem.c (2.4.0), we see the following:
/* On PPro and successors, PCD alone doesn't always mean
uncached because of interactions with the MTRRs. PCD | PWT
means definitely uncached. */
if (boot_cpu_data.x86 > 3)
prot |= _PAGE_PCD | _PAGE_PWT;
Does this mean ioremap_nocache() may not do the job?
-mark
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WARNING: multiple messages have this Message-ID (diff)
From: Mark Mokryn <mark@sangate.com>
To: linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: ioremap_nocache problem?
Date: Tue, 23 Jan 2001 12:30:00 +0200 [thread overview]
Message-ID: <3A6D5D28.C132D416@sangate.com> (raw)
ioremap_nocache does the following:
return __ioremap(offset, size, _PAGE_PCD);
However, in drivers/char/mem.c (2.4.0), we see the following:
/* On PPro and successors, PCD alone doesn't always mean
uncached because of interactions with the MTRRs. PCD | PWT
means definitely uncached. */
if (boot_cpu_data.x86 > 3)
prot |= _PAGE_PCD | _PAGE_PWT;
Does this mean ioremap_nocache() may not do the job?
-mark
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux.eu.org/Linux-MM/
next reply other threads:[~2001-01-23 10:32 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-01-23 10:30 Mark Mokryn [this message]
2001-01-23 10:30 ` ioremap_nocache problem? Mark Mokryn
2001-01-23 16:53 ` Timur Tabi
2001-01-23 16:53 ` Timur Tabi
2001-01-25 15:16 ` Stephen C. Tweedie
2001-01-25 15:16 ` Stephen C. Tweedie
2001-01-25 15:56 ` Timur Tabi
2001-01-25 16:44 ` Roman Zippel
2001-01-25 16:44 ` Roman Zippel
2001-01-25 16:49 ` Timur Tabi
2001-01-26 10:39 ` Stephen C. Tweedie
2001-01-26 10:39 ` Stephen C. Tweedie
2001-01-25 16:49 ` Timur Tabi
2001-01-25 17:04 ` Jeff Hartmann
2001-01-25 17:04 ` Jeff Hartmann
2001-01-25 17:11 ` Timur Tabi
2001-01-25 17:11 ` Timur Tabi
[not found] ` <E14LpvQ-0008Pw-00@mail.valinux.com>
2001-01-25 17:47 ` Jeff Hartmann
2001-01-25 17:47 ` Jeff Hartmann
2001-01-25 17:53 ` Timur Tabi
2001-01-26 10:43 ` Stephen C. Tweedie
2001-01-26 10:43 ` Stephen C. Tweedie
2001-01-26 16:32 ` Eric W. Biederman
2001-01-26 19:22 ` Timur Tabi
2001-01-25 17:53 ` Timur Tabi
2001-01-25 18:13 ` Jeff Hartmann
2001-01-25 18:13 ` Jeff Hartmann
2001-01-25 18:18 ` Timur Tabi
2001-01-25 18:18 ` Timur Tabi
[not found] ` <E14Lqyt-0003z6-00@mail.valinux.com>
2001-01-25 18:46 ` Jeff Hartmann
2001-01-25 18:46 ` Jeff Hartmann
[not found] ` <200101251556.f0PFuPd01743@mail.redhat.com>
2001-01-26 10:37 ` Stephen C. Tweedie
2001-01-26 10:37 ` Stephen C. Tweedie
2001-01-25 15:56 ` Timur Tabi
2001-01-23 18:12 ` Roman Zippel
2001-01-23 18:12 ` Roman Zippel
2001-01-23 18:38 ` Timur Tabi
2001-01-24 0:50 ` David Wragg
2001-01-24 0:50 ` David Wragg, David Wragg
2001-01-24 15:14 ` Timur Tabi
2001-01-24 15:14 ` Timur Tabi
[not found] ` <E14LRce-0008FU-00@diver.doc.ic.ac.uk>
2001-01-24 15:39 ` David Wragg
2001-01-24 15:39 ` David Wragg
2001-01-23 18:38 ` Timur Tabi
2001-01-24 1:01 ` David Wragg
2001-01-24 1:01 ` David Wragg
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