1 files changed, 39 insertions, 27 deletions

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 096fde0ebcb..ad72922919e 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -358,14 +358,14 @@ static void intel_pstate_sysfs_expose_params(void)
 static int intel_pstate_min_pstate(void)
 {
 	u64 value;
-	rdmsrl(0xCE, value);
+	rdmsrl(MSR_PLATFORM_INFO, value);
 	return (value >> 40) & 0xFF;
 }
 
 static int intel_pstate_max_pstate(void)
 {
 	u64 value;
-	rdmsrl(0xCE, value);
+	rdmsrl(MSR_PLATFORM_INFO, value);
 	return (value >> 8) & 0xFF;
 }
 
@@ -373,7 +373,7 @@ static int intel_pstate_turbo_pstate(void)
 {
 	u64 value;
 	int nont, ret;
-	rdmsrl(0x1AD, value);
+	rdmsrl(MSR_NHM_TURBO_RATIO_LIMIT, value);
 	nont = intel_pstate_max_pstate();
 	ret = ((value) & 255);
 	if (ret <= nont)
@@ -454,7 +454,7 @@ static inline void intel_pstate_calc_busy(struct cpudata *cpu,
 					sample->idletime_us * 100,
 					sample->duration_us);
 	core_pct = div64_u64(sample->aperf * 100, sample->mperf);
-	sample->freq = cpu->pstate.turbo_pstate * core_pct * 1000;
+	sample->freq = cpu->pstate.max_pstate * core_pct * 1000;
 
 	sample->core_pct_busy = div_s64((sample->pstate_pct_busy * core_pct),
 					100);
@@ -662,6 +662,9 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)
 
 	cpu = all_cpu_data[policy->cpu];
 
+	if (!policy->cpuinfo.max_freq)
+		return -ENODEV;
+
 	intel_pstate_get_min_max(cpu, &min, &max);
 
 	limits.min_perf_pct = (policy->min * 100) / policy->cpuinfo.max_freq;
@@ -747,37 +750,34 @@ static struct cpufreq_driver intel_pstate_driver = {
 	.owner		= THIS_MODULE,
 };
 
-static void intel_pstate_exit(void)
+static int __initdata no_load;
+
+static int intel_pstate_msrs_not_valid(void)
 {
-	int cpu;
+	/* Check that all the msr's we are using are valid. */
+	u64 aperf, mperf, tmp;
 
-	sysfs_remove_group(intel_pstate_kobject,
-				&intel_pstate_attr_group);
-	debugfs_remove_recursive(debugfs_parent);
+	rdmsrl(MSR_IA32_APERF, aperf);
+	rdmsrl(MSR_IA32_MPERF, mperf);
 
-	cpufreq_unregister_driver(&intel_pstate_driver);
+	if (!intel_pstate_min_pstate() ||
+		!intel_pstate_max_pstate() ||
+		!intel_pstate_turbo_pstate())
+		return -ENODEV;
 
-	if (!all_cpu_data)
-		return;
+	rdmsrl(MSR_IA32_APERF, tmp);
+	if (!(tmp - aperf))
+		return -ENODEV;
 
-	get_online_cpus();
-	for_each_online_cpu(cpu) {
-		if (all_cpu_data[cpu]) {
-			del_timer_sync(&all_cpu_data[cpu]->timer);
-			kfree(all_cpu_data[cpu]);
-		}
-	}
+	rdmsrl(MSR_IA32_MPERF, tmp);
+	if (!(tmp - mperf))
+		return -ENODEV;
 
-	put_online_cpus();
-	vfree(all_cpu_data);
+	return 0;
 }
-module_exit(intel_pstate_exit);
-
-static int __initdata no_load;
-
 static int __init intel_pstate_init(void)
 {
-	int rc = 0;
+	int cpu, rc = 0;
 	const struct x86_cpu_id *id;
 
 	if (no_load)
@@ -787,6 +787,9 @@ static int __init intel_pstate_init(void)
 	if (!id)
 		return -ENODEV;
 
+	if (intel_pstate_msrs_not_valid())
+		return -ENODEV;
+
 	pr_info("Intel P-state driver initializing.\n");
 
 	all_cpu_data = vmalloc(sizeof(void *) * num_possible_cpus());
@@ -802,7 +805,16 @@ static int __init intel_pstate_init(void)
 	intel_pstate_sysfs_expose_params();
 	return rc;
 out:
-	intel_pstate_exit();
+	get_online_cpus();
+	for_each_online_cpu(cpu) {
+		if (all_cpu_data[cpu]) {
+			del_timer_sync(&all_cpu_data[cpu]->timer);
+			kfree(all_cpu_data[cpu]);
+		}
+	}
+
+	put_online_cpus();
+	vfree(all_cpu_data);
 	return -ENODEV;
 }
 device_initcall(intel_pstate_init);