Merge tag 'v3.15' into next

Linux 3.15

1 files changed, 30 insertions, 27 deletions

diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 5cd9bfabd64..a80029035bf 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