From: Greg KH <gregkh@suse.de>
To: linux-kernel@vger.kernel.org, stable@kernel.org
Cc: stable-review@kernel.org, torvalds@linux-foundation.org,
akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk,
Andreas Herrmann <andreas.herrmann3@amd.com>,
"H. Peter Anvin" <hpa@linux.intel.com>
Subject: [19/82] x86, mtrr: Assume SYS_CFG[Tom2ForceMemTypeWB] exists on all future AMD CPUs
Date: Fri, 19 Nov 2010 13:55:40 -0800 [thread overview]
Message-ID: <20101119215640.306813138@clark.site> (raw)
In-Reply-To: <20101119215658.GA7804@kroah.com
2.6.35-stable review patch. If anyone has any objections, please let us know.
------------------
From: Andreas Herrmann <andreas.herrmann3@amd.com>
commit 3fdbf004c1706480a7c7fac3c9d836fa6df20d7d upstream.
Instead of adapting the CPU family check in amd_special_default_mtrr()
for each new CPU family assume that all new AMD CPUs support the
necessary bits in SYS_CFG MSR.
Tom2Enabled is architectural (defined in APM Vol.2).
Tom2ForceMemTypeWB is defined in all BKDGs starting with K8 NPT.
In pre K8-NPT BKDG this bit is reserved (read as zero).
W/o this adaption Linux would unnecessarily complain about bad MTRR
settings on every new AMD CPU family, e.g.
[ 0.000000] WARNING: BIOS bug: CPU MTRRs don't cover all of memory, losing 4863MB of RAM.
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
LKML-Reference: <20100930123235.GB20545@loge.amd.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
arch/x86/kernel/cpu/mtrr/cleanup.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/kernel/cpu/mtrr/cleanup.c
+++ b/arch/x86/kernel/cpu/mtrr/cleanup.c
@@ -827,7 +827,7 @@ int __init amd_special_default_mtrr(void
if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
return 0;
- if (boot_cpu_data.x86 < 0xf || boot_cpu_data.x86 > 0x11)
+ if (boot_cpu_data.x86 < 0xf)
return 0;
/* In case some hypervisor doesn't pass SYSCFG through: */
if (rdmsr_safe(MSR_K8_SYSCFG, &l, &h) < 0)
reply other threads:[~2010-11-19 22:32 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
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=20101119215640.306813138@clark.site \
--to=gregkh@suse.de \
--cc=akpm@linux-foundation.org \
--cc=alan@lxorguk.ukuu.org.uk \
--cc=andreas.herrmann3@amd.com \
--cc=hpa@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=stable-review@kernel.org \
--cc=stable@kernel.org \
--cc=torvalds@linux-foundation.org \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox