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authorThomas Gleixner <tglx@linutronix.de>2010-05-10 11:59:37 +0200
committerThomas Gleixner <tglx@linutronix.de>2010-05-10 14:20:42 +0200
commitdbb6be6d5e974c42bbecd183effaa0df69e1dd8b (patch)
tree5735cb47e70853d057a9881dd0ce44b83e88fa63 /arch/x86/kernel/cpu/intel.c
parent6a867a395558a7f882d041783e4cdea6744ca2bf (diff)
parentb57f95a38233a2e73b679bea4a5453a1cc2a1cc9 (diff)
Merge branch 'linus' into timers/core
Reason: Further posix_cpu_timer patches depend on mainline changes Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/kernel/cpu/intel.c')
-rw-r--r--arch/x86/kernel/cpu/intel.c21
1 files changed, 21 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 7e1cca13af3..1366c7cfd48 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -47,6 +47,27 @@ static void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
(c->x86 == 0x6 && c->x86_model >= 0x0e))
set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
+ /*
+ * Atom erratum AAE44/AAF40/AAG38/AAH41:
+ *
+ * A race condition between speculative fetches and invalidating
+ * a large page. This is worked around in microcode, but we
+ * 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);
+ }
+ }
+
#ifdef CONFIG_X86_64
set_cpu_cap(c, X86_FEATURE_SYSENTER32);
#else