linux-kernel - [PATCH 2/3] x86, intel: Use cpu

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Message-Id: <1306351948-23382-2-git-send-email-andi@firstfloor.org>
Date:	Wed, 25 May 2011 12:32:27 -0700
From:	Andi Kleen <andi@...stfloor.org>
To:	x86@...nel.org
Cc:	linux-kernel@...r.kernel.org, Andi Kleen <ak@...ux.intel.com>
Subject: [PATCH 2/3] x86, intel: Use cpu_update for Atom errata check

From: Andi Kleen <ak@...ux.intel.com>

Now that the cpu update level is available the Atom PSE errata
check can use it directly without reading the MSR again.

Signed-off-by: Andi Kleen <ak@...ux.intel.com>
---
 arch/x86/kernel/cpu/intel.c |   15 ++++-----------
 1 files changed, 4 insertions(+), 11 deletions(-)

diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index ba5ba17..701efa4 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -55,17 +55,10 @@ static void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
 	 * need the microcode to have already been loaded... so if it is
 	 * not, recommend a BIOS update and disable large pages.
 	 */
-	if (c->x86 == 6 && c->x86_model == 0x1c && c->x86_mask <= 2) {
-		u32 ucode, junk;
-
-		wrmsr(MSR_IA32_UCODE_REV, 0, 0);
-		sync_core();
-		rdmsr(MSR_IA32_UCODE_REV, junk, ucode);
-
-		if (ucode < 0x20e) {
-			printk(KERN_WARNING "Atom PSE erratum detected, BIOS microcode update recommended\n");
-			clear_cpu_cap(c, X86_FEATURE_PSE);
-		}
+	if (c->x86 == 6 && c->x86_model == 0x1c && c->x86_mask <= 2 &&
+	    c->cpu_update < 0x20e) {
+		printk(KERN_WARNING "Atom PSE erratum detected, BIOS microcode update recommended\n");
+		clear_cpu_cap(c, X86_FEATURE_PSE);
 	}
 
 #ifdef CONFIG_X86_64
-- 
1.7.4.4

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