1 files changed, 39 insertions, 17 deletions

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index f6dd1e76112..cc3a8e6c92b 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -1,5 +1,5 @@
 /*
- * cpufreq_snb.c: Native P state management for Intel processors
+ * intel_pstate.c: Native P state management for Intel processors
  *
  * (C) Copyright 2012 Intel Corporation
  * Author: Dirk Brandewie <dirk.j.brandewie@intel.com>
@@ -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);
@@ -502,7 +502,6 @@ static inline void intel_pstate_set_sample_time(struct cpudata *cpu)
 
 	sample_time = cpu->pstate_policy->sample_rate_ms;
 	delay = msecs_to_jiffies(sample_time);
-	delay -= jiffies % delay;
 	mod_timer_pinned(&cpu->timer, jiffies + delay);
 }
 
@@ -658,30 +657,27 @@ static unsigned int intel_pstate_get(unsigned int cpu_num)
 static int intel_pstate_set_policy(struct cpufreq_policy *policy)
 {
 	struct cpudata *cpu;
-	int min, max;
 
 	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;
-	limits.min_perf_pct = clamp_t(int, limits.min_perf_pct, 0 , 100);
-	limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));
-
-	limits.max_perf_pct = policy->max * 100 / policy->cpuinfo.max_freq;
-	limits.max_perf_pct = clamp_t(int, limits.max_perf_pct, 0 , 100);
-	limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100));
-
 	if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) {
 		limits.min_perf_pct = 100;
 		limits.min_perf = int_tofp(1);
 		limits.max_perf_pct = 100;
 		limits.max_perf = int_tofp(1);
 		limits.no_turbo = 0;
+		return 0;
 	}
+	limits.min_perf_pct = (policy->min * 100) / policy->cpuinfo.max_freq;
+	limits.min_perf_pct = clamp_t(int, limits.min_perf_pct, 0 , 100);
+	limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));
+
+	limits.max_perf_pct = policy->max * 100 / policy->cpuinfo.max_freq;
+	limits.max_perf_pct = clamp_t(int, limits.max_perf_pct, 0 , 100);
+	limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100));
 
 	return 0;
 }
@@ -752,6 +748,29 @@ static struct cpufreq_driver intel_pstate_driver = {
 
 static int __initdata no_load;
 
+static int intel_pstate_msrs_not_valid(void)
+{
+	/* Check that all the msr's we are using are valid. */
+	u64 aperf, mperf, tmp;
+
+	rdmsrl(MSR_IA32_APERF, aperf);
+	rdmsrl(MSR_IA32_MPERF, mperf);
+
+	if (!intel_pstate_min_pstate() ||
+		!intel_pstate_max_pstate() ||
+		!intel_pstate_turbo_pstate())
+		return -ENODEV;
+
+	rdmsrl(MSR_IA32_APERF, tmp);
+	if (!(tmp - aperf))
+		return -ENODEV;
+
+	rdmsrl(MSR_IA32_MPERF, tmp);
+	if (!(tmp - mperf))
+		return -ENODEV;
+
+	return 0;
+}
 static int __init intel_pstate_init(void)
 {
 	int cpu, rc = 0;
@@ -764,6 +783,9 @@ 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());