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Diffstat (limited to 'arch/x86/kernel/cpu/intel.c')
-rw-r--r--arch/x86/kernel/cpu/intel.c42
1 files changed, 39 insertions, 3 deletions
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 24ff26a38ad..191117f1ad5 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -13,6 +13,7 @@
#include <asm/uaccess.h>
#include <asm/ds.h>
#include <asm/bugs.h>
+#include <asm/cpu.h>
#ifdef CONFIG_X86_64
#include <asm/topology.h>
@@ -24,7 +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)
@@ -63,6 +63,18 @@ static void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
}
+ /*
+ * 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
@@ -99,6 +111,28 @@ static void __cpuinit trap_init_f00f_bug(void)
}
#endif
+static void __cpuinit intel_smp_check(struct cpuinfo_x86 *c)
+{
+#ifdef CONFIG_SMP
+ /* calling is from identify_secondary_cpu() ? */
+ if (c->cpu_index == boot_cpu_id)
+ return;
+
+ /*
+ * Mask B, Pentium, but not Pentium MMX
+ */
+ if (c->x86 == 5 &&
+ c->x86_mask >= 1 && c->x86_mask <= 4 &&
+ c->x86_model <= 3) {
+ /*
+ * Remember we have B step Pentia with bugs
+ */
+ WARN_ONCE(1, "WARNING: SMP operation may be unreliable"
+ "with B stepping processors.\n");
+ }
+#endif
+}
+
static void __cpuinit intel_workarounds(struct cpuinfo_x86 *c)
{
unsigned long lo, hi;
@@ -135,10 +169,10 @@ 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);
}
}
@@ -175,6 +209,8 @@ static void __cpuinit intel_workarounds(struct cpuinfo_x86 *c)
#ifdef CONFIG_X86_NUMAQ
numaq_tsc_disable();
#endif
+
+ intel_smp_check(c);
}
#else
static void __cpuinit intel_workarounds(struct cpuinfo_x86 *c)