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Diffstat (limited to 'arch/x86/kernel/cpu/intel.c')
-rw-r--r--arch/x86/kernel/cpu/intel.c17
1 files changed, 14 insertions, 3 deletions
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 5fff00c..1a89a2b 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -25,7 +25,6 @@
#ifdef CONFIG_X86_LOCAL_APIC
#include <asm/mpspec.h>
#include <asm/apic.h>
-#include <mach_apic.h>
#endif
static void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
@@ -69,6 +68,18 @@ static void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
sched_clock_stable = 1;
}
+ /*
+ * There is a known erratum on Pentium III and Core Solo
+ * and Core Duo CPUs.
+ * " Page with PAT set to WC while associated MTRR is UC
+ * may consolidate to UC "
+ * Because of this erratum, it is better to stick with
+ * setting WC in MTRR rather than using PAT on these CPUs.
+ *
+ * Enable PAT WC only on P4, Core 2 or later CPUs.
+ */
+ if (c->x86 == 6 && c->x86_model < 15)
+ clear_cpu_cap(c, X86_FEATURE_PAT);
}
#ifdef CONFIG_X86_32
@@ -141,10 +152,10 @@ static void __cpuinit intel_workarounds(struct cpuinfo_x86 *c)
*/
if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) {
rdmsr(MSR_IA32_MISC_ENABLE, lo, hi);
- if ((lo & (1<<9)) == 0) {
+ if ((lo & MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE) == 0) {
printk (KERN_INFO "CPU: C0 stepping P4 Xeon detected.\n");
printk (KERN_INFO "CPU: Disabling hardware prefetching (Errata 037)\n");
- lo |= (1<<9); /* Disable hw prefetching */
+ lo |= MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE;
wrmsr (MSR_IA32_MISC_ENABLE, lo, hi);
}
}
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