1 files changed, 56 insertions, 49 deletions

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index dd66decf2087..002f5169d4eb 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -50,6 +50,8 @@
 #define int_tofp(X) ((int64_t)(X) << FRAC_BITS)
 #define fp_toint(X) ((X) >> FRAC_BITS)
 
+#define ONE_EIGHTH_FP ((int64_t)1 << (FRAC_BITS - 3))
+
 #define EXT_BITS 6
 #define EXT_FRAC_BITS (EXT_BITS + FRAC_BITS)
 #define fp_ext_toint(X) ((X) >> EXT_FRAC_BITS)
@@ -895,7 +897,7 @@ static void intel_pstate_update_policies(void)
 /************************** sysfs begin ************************/
 #define show_one(file_name, object)					\
 	static ssize_t show_##file_name					\
-	(struct kobject *kobj, struct attribute *attr, char *buf)	\
+	(struct kobject *kobj, struct kobj_attribute *attr, char *buf)	\
 	{								\
 		return sprintf(buf, "%u\n", global.object);		\
 	}
@@ -904,7 +906,7 @@ static ssize_t intel_pstate_show_status(char *buf);
 static int intel_pstate_update_status(const char *buf, size_t size);
 
 static ssize_t show_status(struct kobject *kobj,
-			   struct attribute *attr, char *buf)
+			   struct kobj_attribute *attr, char *buf)
 {
 	ssize_t ret;
 
@@ -915,7 +917,7 @@ static ssize_t show_status(struct kobject *kobj,
 	return ret;
 }
 
-static ssize_t store_status(struct kobject *a, struct attribute *b,
+static ssize_t store_status(struct kobject *a, struct kobj_attribute *b,
 			    const char *buf, size_t count)
 {
 	char *p = memchr(buf, '\n', count);
@@ -929,7 +931,7 @@ static ssize_t store_status(struct kobject *a, struct attribute *b,
 }
 
 static ssize_t show_turbo_pct(struct kobject *kobj,
-				struct attribute *attr, char *buf)
+				struct kobj_attribute *attr, char *buf)
 {
 	struct cpudata *cpu;
 	int total, no_turbo, turbo_pct;
@@ -955,7 +957,7 @@ static ssize_t show_turbo_pct(struct kobject *kobj,
 }
 
 static ssize_t show_num_pstates(struct kobject *kobj,
-				struct attribute *attr, char *buf)
+				struct kobj_attribute *attr, char *buf)
 {
 	struct cpudata *cpu;
 	int total;
@@ -976,7 +978,7 @@ static ssize_t show_num_pstates(struct kobject *kobj,
 }
 
 static ssize_t show_no_turbo(struct kobject *kobj,
-			     struct attribute *attr, char *buf)
+			     struct kobj_attribute *attr, char *buf)
 {
 	ssize_t ret;
 
@@ -998,7 +1000,7 @@ static ssize_t show_no_turbo(struct kobject *kobj,
 	return ret;
 }
 
-static ssize_t store_no_turbo(struct kobject *a, struct attribute *b,
+static ssize_t store_no_turbo(struct kobject *a, struct kobj_attribute *b,
 			      const char *buf, size_t count)
 {
 	unsigned int input;
@@ -1045,7 +1047,7 @@ static ssize_t store_no_turbo(struct kobject *a, struct attribute *b,
 	return count;
 }
 
-static ssize_t store_max_perf_pct(struct kobject *a, struct attribute *b,
+static ssize_t store_max_perf_pct(struct kobject *a, struct kobj_attribute *b,
 				  const char *buf, size_t count)
 {
 	unsigned int input;
@@ -1075,7 +1077,7 @@ static ssize_t store_max_perf_pct(struct kobject *a, struct attribute *b,
 	return count;
 }
 
-static ssize_t store_min_perf_pct(struct kobject *a, struct attribute *b,
+static ssize_t store_min_perf_pct(struct kobject *a, struct kobj_attribute *b,
 				  const char *buf, size_t count)
 {
 	unsigned int input;
@@ -1107,12 +1109,13 @@ static ssize_t store_min_perf_pct(struct kobject *a, struct attribute *b,
 }
 
 static ssize_t show_hwp_dynamic_boost(struct kobject *kobj,
-				struct attribute *attr, char *buf)
+				struct kobj_attribute *attr, char *buf)
 {
 	return sprintf(buf, "%u\n", hwp_boost);
 }
 
-static ssize_t store_hwp_dynamic_boost(struct kobject *a, struct attribute *b,
+static ssize_t store_hwp_dynamic_boost(struct kobject *a,
+				       struct kobj_attribute *b,
 				       const char *buf, size_t count)
 {
 	unsigned int input;
@@ -1444,12 +1447,6 @@ static int knl_get_turbo_pstate(void)
 	return ret;
 }
 
-static int intel_pstate_get_base_pstate(struct cpudata *cpu)
-{
-	return global.no_turbo || global.turbo_disabled ?
-			cpu->pstate.max_pstate : cpu->pstate.turbo_pstate;
-}
-
 static void intel_pstate_set_pstate(struct cpudata *cpu, int pstate)
 {
 	trace_cpu_frequency(pstate * cpu->pstate.scaling, cpu->cpu);
@@ -1470,11 +1467,9 @@ static void intel_pstate_set_min_pstate(struct cpudata *cpu)
 
 static void intel_pstate_max_within_limits(struct cpudata *cpu)
 {
-	int pstate;
+	int pstate = max(cpu->pstate.min_pstate, cpu->max_perf_ratio);
 
 	update_turbo_state();
-	pstate = intel_pstate_get_base_pstate(cpu);
-	pstate = max(cpu->pstate.min_pstate, cpu->max_perf_ratio);
 	intel_pstate_set_pstate(cpu, pstate);
 }
 
@@ -1678,17 +1673,14 @@ static inline int32_t get_avg_pstate(struct cpudata *cpu)
 static inline int32_t get_target_pstate(struct cpudata *cpu)
 {
 	struct sample *sample = &cpu->sample;
-	int32_t busy_frac, boost;
+	int32_t busy_frac;
 	int target, avg_pstate;
 
 	busy_frac = div_fp(sample->mperf << cpu->aperf_mperf_shift,
 			   sample->tsc);
 
-	boost = cpu->iowait_boost;
-	cpu->iowait_boost >>= 1;
-
-	if (busy_frac < boost)
-		busy_frac = boost;
+	if (busy_frac < cpu->iowait_boost)
+		busy_frac = cpu->iowait_boost;
 
 	sample->busy_scaled = busy_frac * 100;
 
@@ -1715,11 +1707,9 @@ static inline int32_t get_target_pstate(struct cpudata *cpu)
 
 static int intel_pstate_prepare_request(struct cpudata *cpu, int pstate)
 {
-	int max_pstate = intel_pstate_get_base_pstate(cpu);
-	int min_pstate;
+	int min_pstate = max(cpu->pstate.min_pstate, cpu->min_perf_ratio);
+	int max_pstate = max(min_pstate, cpu->max_perf_ratio);
 
-	min_pstate = max(cpu->pstate.min_pstate, cpu->min_perf_ratio);
-	max_pstate = max(min_pstate, cpu->max_perf_ratio);
 	return clamp_t(int, pstate, min_pstate, max_pstate);
 }
 
@@ -1767,29 +1757,30 @@ static void intel_pstate_update_util(struct update_util_data *data, u64 time,
 	if (smp_processor_id() != cpu->cpu)
 		return;
 
+	delta_ns = time - cpu->last_update;
 	if (flags & SCHED_CPUFREQ_IOWAIT) {
-		cpu->iowait_boost = int_tofp(1);
-		cpu->last_update = time;
-		/*
-		 * The last time the busy was 100% so P-state was max anyway
-		 * so avoid overhead of computation.
-		 */
-		if (fp_toint(cpu->sample.busy_scaled) == 100)
-			return;
-
-		goto set_pstate;
+		/* Start over if the CPU may have been idle. */
+		if (delta_ns > TICK_NSEC) {
+			cpu->iowait_boost = ONE_EIGHTH_FP;
+		} else if (cpu->iowait_boost) {
+			cpu->iowait_boost <<= 1;
+			if (cpu->iowait_boost > int_tofp(1))
+				cpu->iowait_boost = int_tofp(1);
+		} else {
+			cpu->iowait_boost = ONE_EIGHTH_FP;
+		}
 	} else if (cpu->iowait_boost) {
 		/* Clear iowait_boost if the CPU may have been idle. */
-		delta_ns = time - cpu->last_update;
 		if (delta_ns > TICK_NSEC)
 			cpu->iowait_boost = 0;
+		else
+			cpu->iowait_boost >>= 1;
 	}
 	cpu->last_update = time;
 	delta_ns = time - cpu->sample.time;
 	if ((s64)delta_ns < INTEL_PSTATE_SAMPLING_INTERVAL)
 		return;
 
-set_pstate:
 	if (intel_pstate_sample(cpu, time))
 		intel_pstate_adjust_pstate(cpu);
 }
@@ -1976,7 +1967,8 @@ static void intel_pstate_update_perf_limits(struct cpufreq_policy *policy,
 	if (hwp_active) {
 		intel_pstate_get_hwp_max(cpu->cpu, &turbo_max, &max_state);
 	} else {
-		max_state = intel_pstate_get_base_pstate(cpu);
+		max_state = global.no_turbo || global.turbo_disabled ?
+			cpu->pstate.max_pstate : cpu->pstate.turbo_pstate;
 		turbo_max = cpu->pstate.turbo_pstate;
 	}
 
@@ -2475,6 +2467,7 @@ static bool __init intel_pstate_no_acpi_pss(void)
 		kfree(pss);
 	}
 
+	pr_debug("ACPI _PSS not found\n");
 	return true;
 }
 
@@ -2485,9 +2478,14 @@ static bool __init intel_pstate_no_acpi_pcch(void)
 
 	status = acpi_get_handle(NULL, "\\_SB", &handle);
 	if (ACPI_FAILURE(status))
-		return true;
+		goto not_found;
+
+	if (acpi_has_method(handle, "PCCH"))
+		return false;
 
-	return !acpi_has_method(handle, "PCCH");
+not_found:
+	pr_debug("ACPI PCCH not found\n");
+	return true;
 }
 
 static bool __init intel_pstate_has_acpi_ppc(void)
@@ -2502,6 +2500,7 @@ static bool __init intel_pstate_has_acpi_ppc(void)
 		if (acpi_has_method(pr->handle, "_PPC"))
 			return true;
 	}
+	pr_debug("ACPI _PPC not found\n");
 	return false;
 }
 
@@ -2539,8 +2538,10 @@ static bool __init intel_pstate_platform_pwr_mgmt_exists(void)
 	id = x86_match_cpu(intel_pstate_cpu_oob_ids);
 	if (id) {
 		rdmsrl(MSR_MISC_PWR_MGMT, misc_pwr);
-		if ( misc_pwr & (1 << 8))
+		if (misc_pwr & (1 << 8)) {
+			pr_debug("Bit 8 in the MISC_PWR_MGMT MSR set\n");
 			return true;
+		}
 	}
 
 	idx = acpi_match_platform_list(plat_info);
@@ -2606,22 +2607,28 @@ static int __init intel_pstate_init(void)
 		}
 	} else {
 		id = x86_match_cpu(intel_pstate_cpu_ids);
-		if (!id)
+		if (!id) {
+			pr_info("CPU ID not supported\n");
 			return -ENODEV;
+		}
 
 		copy_cpu_funcs((struct pstate_funcs *)id->driver_data);
 	}
 
-	if (intel_pstate_msrs_not_valid())
+	if (intel_pstate_msrs_not_valid()) {
+		pr_info("Invalid MSRs\n");
 		return -ENODEV;
+	}
 
 hwp_cpu_matched:
 	/*
 	 * The Intel pstate driver will be ignored if the platform
 	 * firmware has its own power management modes.
 	 */
-	if (intel_pstate_platform_pwr_mgmt_exists())
+	if (intel_pstate_platform_pwr_mgmt_exists()) {
+		pr_info("P-states controlled by the platform\n");
 		return -ENODEV;
+	}
 
 	if (!hwp_active && hwp_only)
 		return -ENOTSUPP;