From: Manfred Spraul <manfred@colorfullife.com>
To: Terence Ripperda <tripperda@nvidia.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: PAT support
Date: Tue, 13 Apr 2004 07:34:22 +0200 [thread overview]
Message-ID: <407B7BDE.5030002@colorfullife.com> (raw)
Hi Terence,
in your patch, you write
+/* Here is the PAT's default layout on ia32 cpus when we are done.
+ * PAT0: Write Back
+ * PAT1: Write Combine
+ * PAT2: Uncached
+ * PAT3: Uncacheable
+ * PAT4: Write Through
+ * PAT5: Write Protect
+ * PAT6: Uncached
+ * PAT7: Uncacheable
Is that layout possible?
There is an errata in the B2 and C1 stepping of the Pentium 4 cpus that
results in incorrect PAT numbers: the highest bit is ignored by the CPU
under some circumstances. There's a similar errata (E27) that affects
all Pentium 3 cpus: The highest bit is always ignored.
I think we need a fallback to 4 PAT entries.
--
Manfred
next reply other threads:[~2004-04-13 5:34 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-04-13 5:34 Manfred Spraul [this message]
2004-04-13 14:02 ` PAT support Pavel Machek
2004-04-13 16:40 ` Terence Ripperda
2004-04-15 4:05 ` Eric W. Biederman
-- strict thread matches above, loose matches on Subject: below --
2004-04-15 21:38 Albert Cahalan
[not found] <1KifY-uA-7@gated-at.bofh.it>
2004-04-13 0:01 ` Andi Kleen
2004-04-13 16:21 ` Terence Ripperda
2004-04-14 0:58 ` Andi Kleen
2004-04-16 18:07 ` Terence Ripperda
2004-04-17 0:42 ` Andi Kleen
2004-04-19 22:54 ` Terence Ripperda
2004-04-20 18:51 ` Andi Kleen
2004-04-21 23:19 ` Terence Ripperda
2004-04-22 4:21 ` Andi Kleen
2004-04-15 4:11 ` Eric W. Biederman
2004-04-15 16:38 ` Andi Kleen
2004-04-15 18:39 ` Eric W. Biederman
2004-04-12 22:29 Terence Ripperda
2004-04-13 8:36 ` Andy Whitcroft
2004-04-13 16:50 ` Terence Ripperda
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=407B7BDE.5030002@colorfullife.com \
--to=manfred@colorfullife.com \
--cc=linux-kernel@vger.kernel.org \
--cc=tripperda@nvidia.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.