Patchwork [03/13] Revert "UBUNTU: Disable 4MB page tables for Atom, work around errata AAE44"

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Submitter Leann Ogasawara
Date May 21, 2010, 11:17 p.m.
Message ID <1274483859.19284.3320.camel@emiko>
Download mbox | patch
Permalink /patch/53218/
State Accepted
Delegated to: Leann Ogasawara
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Comments

Leann Ogasawara - May 21, 2010, 11:17 p.m.
>From 24c239d1bfe52777913b79975286b8a12f9809cd Mon Sep 17 00:00:00 2001
From: Leann Ogasawara <leann.ogasawara@canonical.com>
Date: Fri, 21 May 2010 14:26:53 -0700
Subject: [PATCH 03/13] Revert "UBUNTU: Disable 4MB page tables for Atom, work around errata AAE44"

This reverts commit e9c6db30796c6c2cd4e31308e44cbe9ae934814a.

Drop this patch in favor of the upstream incantation.

  commit 7a0fc404ae663776e96db43879a0fa24fec1fa3a
  Author: H. Peter Anvin <hpa@linux.intel.com>
  Date:   Tue Apr 13 14:40:54 2010 -0700

      x86: Disable large pages on CPUs with Atom erratum AAE44

Signed-off-by: Leann Ogasawara <leann.ogasawara@canonical.com>
---
 arch/x86/kernel/cpu/bugs.c |   15 ---------------
 1 files changed, 0 insertions(+), 15 deletions(-)

Patch

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 661c610..01a2652 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -151,20 +151,6 @@  static void __init check_config(void)
 #endif
 }
 
-static void __init check_atom(void)
-{	
-
-	/* 
-	 *  Disable 4MB page tables to work around Intel errata AAE44 for
-	 *  Atom. We cannot guarantee stopping undefined processor behaviour
-	 *  when two pageing structure translations differ with respect to
-	 *  page frame sizes.  Hence, for Atoms we disable the PSE.
-	 */
-	if (boot_cpu_data.x86_model == 0x1c) {
-		clear_bit(X86_FEATURE_PSE, boot_cpu_data.x86_capability);
-		printk(KERN_INFO "Disabling 4MB page tables to avoid TLB bug\n");
-	}
-}
 
 void __init check_bugs(void)
 {
@@ -177,7 +163,6 @@  void __init check_bugs(void)
 	check_fpu();
 	check_hlt();
 	check_popad();
-	check_atom();
 	init_utsname()->machine[1] =
 		'0' + (boot_cpu_data.x86 > 6 ? 6 : boot_cpu_data.x86);
 	alternative_instructions();