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Diffstat (limited to 'arch/x86/kernel/cpu/intel.c')
-rw-r--r--arch/x86/kernel/cpu/intel.c57
1 files changed, 30 insertions, 27 deletions
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 5cd9bfabd645..a80029035bf2 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -31,11 +31,8 @@ static void early_init_intel(struct cpuinfo_x86 *c)
/* Unmask CPUID levels if masked: */
if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
- rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
-
- if (misc_enable & MSR_IA32_MISC_ENABLE_LIMIT_CPUID) {
- misc_enable &= ~MSR_IA32_MISC_ENABLE_LIMIT_CPUID;
- wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
+ if (msr_clear_bit(MSR_IA32_MISC_ENABLE,
+ MSR_IA32_MISC_ENABLE_LIMIT_CPUID_BIT) > 0) {
c->cpuid_level = cpuid_eax(0);
get_cpu_cap(c);
}
@@ -129,16 +126,10 @@ static void early_init_intel(struct cpuinfo_x86 *c)
* Ingo Molnar reported a Pentium D (model 6) and a Xeon
* (model 2) with the same problem.
*/
- if (c->x86 == 15) {
- rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
-
- if (misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING) {
- printk(KERN_INFO "kmemcheck: Disabling fast string operations\n");
-
- misc_enable &= ~MSR_IA32_MISC_ENABLE_FAST_STRING;
- wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
- }
- }
+ if (c->x86 == 15)
+ if (msr_clear_bit(MSR_IA32_MISC_ENABLE,
+ MSR_IA32_MISC_ENABLE_FAST_STRING_BIT) > 0)
+ pr_info("kmemcheck: Disabling fast string operations\n");
#endif
/*
@@ -195,10 +186,16 @@ static void intel_smp_check(struct cpuinfo_x86 *c)
}
}
-static void intel_workarounds(struct cpuinfo_x86 *c)
+static int forcepae;
+static int __init forcepae_setup(char *__unused)
{
- unsigned long lo, hi;
+ forcepae = 1;
+ return 1;
+}
+__setup("forcepae", forcepae_setup);
+static void intel_workarounds(struct cpuinfo_x86 *c)
+{
#ifdef CONFIG_X86_F00F_BUG
/*
* All current models of Pentium and Pentium with MMX technology CPUs
@@ -225,16 +222,26 @@ static void intel_workarounds(struct cpuinfo_x86 *c)
clear_cpu_cap(c, X86_FEATURE_SEP);
/*
+ * PAE CPUID issue: many Pentium M report no PAE but may have a
+ * functionally usable PAE implementation.
+ * Forcefully enable PAE if kernel parameter "forcepae" is present.
+ */
+ if (forcepae) {
+ printk(KERN_WARNING "PAE forced!\n");
+ set_cpu_cap(c, X86_FEATURE_PAE);
+ add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_NOW_UNRELIABLE);
+ }
+
+ /*
* P4 Xeon errata 037 workaround.
* Hardware prefetcher may cause stale data to be loaded into the cache.
*/
if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) {
- rdmsr(MSR_IA32_MISC_ENABLE, lo, hi);
- 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 |= MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE;
- wrmsr(MSR_IA32_MISC_ENABLE, lo, hi);
+ if (msr_set_bit(MSR_IA32_MISC_ENABLE,
+ MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE_BIT)
+ > 0) {
+ pr_info("CPU: C0 stepping P4 Xeon detected.\n");
+ pr_info("CPU: Disabling hardware prefetching (Errata 037)\n");
}
}
@@ -267,10 +274,6 @@ static void intel_workarounds(struct cpuinfo_x86 *c)
}
#endif
-#ifdef CONFIG_X86_NUMAQ
- numaq_tsc_disable();
-#endif
-
intel_smp_check(c);
}
#else