[PATCH 2/3] x86, intel: Use cpu_update for Atom errata check

From: Andi Kleen
Date: Thu Oct 13 2011 - 18:55:42 EST


From: Andi Kleen <ak@xxxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxxx>
Acked-by: H. Peter Anvin <hpa@xxxxxxxxx>
---
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 26627a3..5231312 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -64,17 +64,10 @@ 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->microcode < 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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