Linux-libre 4.6.2-gnu

1 files changed, 328 insertions, 137 deletions

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 3b29308f6..d63074ff6 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -64,6 +64,25 @@ static inline int ceiling_fp(int32_t x)
 	return ret;
 }
 
+/**
+ * struct sample -	Store performance sample
+ * @core_pct_busy:	Ratio of APERF/MPERF in percent, which is actual
+ *			performance during last sample period
+ * @busy_scaled:	Scaled busy value which is used to calculate next
+ *			P state. This can be different than core_pct_busy
+ *			to account for cpu idle period
+ * @aperf:		Difference of actual performance frequency clock count
+ *			read from APERF MSR between last and current sample
+ * @mperf:		Difference of maximum performance frequency clock count
+ *			read from MPERF MSR between last and current sample
+ * @tsc:		Difference of time stamp counter between last and
+ *			current sample
+ * @freq:		Effective frequency calculated from APERF/MPERF
+ * @time:		Current time from scheduler
+ *
+ * This structure is used in the cpudata structure to store performance sample
+ * data for choosing next P State.
+ */
 struct sample {
 	int32_t core_pct_busy;
 	int32_t busy_scaled;
@@ -71,9 +90,23 @@ struct sample {
 	u64 mperf;
 	u64 tsc;
 	int freq;
-	ktime_t time;
+	u64 time;
 };
 
+/**
+ * struct pstate_data - Store P state data
+ * @current_pstate:	Current requested P state
+ * @min_pstate:		Min P state possible for this platform
+ * @max_pstate:		Max P state possible for this platform
+ * @max_pstate_physical:This is physical Max P state for a processor
+ *			This can be higher than the max_pstate which can
+ *			be limited by platform thermal design power limits
+ * @scaling:		Scaling factor to  convert frequency to cpufreq
+ *			frequency units
+ * @turbo_pstate:	Max Turbo P state possible for this platform
+ *
+ * Stores the per cpu model P state limits and current P state.
+ */
 struct pstate_data {
 	int	current_pstate;
 	int	min_pstate;
@@ -83,6 +116,19 @@ struct pstate_data {
 	int	turbo_pstate;
 };
 
+/**
+ * struct vid_data -	Stores voltage information data
+ * @min:		VID data for this platform corresponding to
+ *			the lowest P state
+ * @max:		VID data corresponding to the highest P State.
+ * @turbo:		VID data for turbo P state
+ * @ratio:		Ratio of (vid max - vid min) /
+ *			(max P state - Min P State)
+ *
+ * Stores the voltage data for DVFS (Dynamic Voltage and Frequency Scaling)
+ * This data is used in Atom platforms, where in addition to target P state,
+ * the voltage data needs to be specified to select next P State.
+ */
 struct vid_data {
 	int min;
 	int max;
@@ -90,6 +136,18 @@ struct vid_data {
 	int32_t ratio;
 };
 
+/**
+ * struct _pid -	Stores PID data
+ * @setpoint:		Target set point for busyness or performance
+ * @integral:		Storage for accumulated error values
+ * @p_gain:		PID proportional gain
+ * @i_gain:		PID integral gain
+ * @d_gain:		PID derivative gain
+ * @deadband:		PID deadband
+ * @last_err:		Last error storage for integral part of PID calculation
+ *
+ * Stores PID coefficients and last error for PID controller.
+ */
 struct _pid {
 	int setpoint;
 	int32_t integral;
@@ -100,16 +158,33 @@ struct _pid {
 	int32_t last_err;
 };
 
+/**
+ * struct cpudata -	Per CPU instance data storage
+ * @cpu:		CPU number for this instance data
+ * @update_util:	CPUFreq utility callback information
+ * @pstate:		Stores P state limits for this CPU
+ * @vid:		Stores VID limits for this CPU
+ * @pid:		Stores PID parameters for this CPU
+ * @last_sample_time:	Last Sample time
+ * @prev_aperf:		Last APERF value read from APERF MSR
+ * @prev_mperf:		Last MPERF value read from MPERF MSR
+ * @prev_tsc:		Last timestamp counter (TSC) value
+ * @prev_cummulative_iowait: IO Wait time difference from last and
+ *			current sample
+ * @sample:		Storage for storing last Sample data
+ *
+ * This structure stores per CPU instance data for all CPUs.
+ */
 struct cpudata {
 	int cpu;
 
-	struct timer_list timer;
+	struct update_util_data update_util;
 
 	struct pstate_data pstate;
 	struct vid_data vid;
 	struct _pid pid;
 
-	ktime_t last_sample_time;
+	u64	last_sample_time;
 	u64	prev_aperf;
 	u64	prev_mperf;
 	u64	prev_tsc;
@@ -118,8 +193,22 @@ struct cpudata {
 };
 
 static struct cpudata **all_cpu_data;
+
+/**
+ * struct pid_adjust_policy - Stores static PID configuration data
+ * @sample_rate_ms:	PID calculation sample rate in ms
+ * @sample_rate_ns:	Sample rate calculation in ns
+ * @deadband:		PID deadband
+ * @setpoint:		PID Setpoint
+ * @p_gain_pct:		PID proportional gain
+ * @i_gain_pct:		PID integral gain
+ * @d_gain_pct:		PID derivative gain
+ *
+ * Stores per CPU model static PID configuration data.
+ */
 struct pstate_adjust_policy {
 	int sample_rate_ms;
+	s64 sample_rate_ns;
 	int deadband;
 	int setpoint;
 	int p_gain_pct;
@@ -127,17 +216,36 @@ struct pstate_adjust_policy {
 	int i_gain_pct;
 };
 
+/**
+ * struct pstate_funcs - Per CPU model specific callbacks
+ * @get_max:		Callback to get maximum non turbo effective P state
+ * @get_max_physical:	Callback to get maximum non turbo physical P state
+ * @get_min:		Callback to get minimum P state
+ * @get_turbo:		Callback to get turbo P state
+ * @get_scaling:	Callback to get frequency scaling factor
+ * @get_val:		Callback to convert P state to actual MSR write value
+ * @get_vid:		Callback to get VID data for Atom platforms
+ * @get_target_pstate:	Callback to a function to calculate next P state to use
+ *
+ * Core and Atom CPU models have different way to get P State limits. This
+ * structure is used to store those callbacks.
+ */
 struct pstate_funcs {
 	int (*get_max)(void);
 	int (*get_max_physical)(void);
 	int (*get_min)(void);
 	int (*get_turbo)(void);
 	int (*get_scaling)(void);
-	void (*set)(struct cpudata*, int pstate);
+	u64 (*get_val)(struct cpudata*, int pstate);
 	void (*get_vid)(struct cpudata *);
 	int32_t (*get_target_pstate)(struct cpudata *);
 };
 
+/**
+ * struct cpu_defaults- Per CPU model default config data
+ * @pid_policy:	PID config data
+ * @funcs:		Callback function data
+ */
 struct cpu_defaults {
 	struct pstate_adjust_policy pid_policy;
 	struct pstate_funcs funcs;
@@ -150,6 +258,34 @@ static struct pstate_adjust_policy pid_params;
 static struct pstate_funcs pstate_funcs;
 static int hwp_active;
 
+
+/**
+ * struct perf_limits - Store user and policy limits
+ * @no_turbo:		User requested turbo state from intel_pstate sysfs
+ * @turbo_disabled:	Platform turbo status either from msr
+ *			MSR_IA32_MISC_ENABLE or when maximum available pstate
+ *			matches the maximum turbo pstate
+ * @max_perf_pct:	Effective maximum performance limit in percentage, this
+ *			is minimum of either limits enforced by cpufreq policy
+ *			or limits from user set limits via intel_pstate sysfs
+ * @min_perf_pct:	Effective minimum performance limit in percentage, this
+ *			is maximum of either limits enforced by cpufreq policy
+ *			or limits from user set limits via intel_pstate sysfs
+ * @max_perf:		This is a scaled value between 0 to 255 for max_perf_pct
+ *			This value is used to limit max pstate
+ * @min_perf:		This is a scaled value between 0 to 255 for min_perf_pct
+ *			This value is used to limit min pstate
+ * @max_policy_pct:	The maximum performance in percentage enforced by
+ *			cpufreq setpolicy interface
+ * @max_sysfs_pct:	The maximum performance in percentage enforced by
+ *			intel pstate sysfs interface
+ * @min_policy_pct:	The minimum performance in percentage enforced by
+ *			cpufreq setpolicy interface
+ * @min_sysfs_pct:	The minimum performance in percentage enforced by
+ *			intel pstate sysfs interface
+ *
+ * Storage for user and policy defined limits.
+ */
 struct perf_limits {
 	int no_turbo;
 	int turbo_disabled;
@@ -197,8 +333,8 @@ static struct perf_limits *limits = &powersave_limits;
 
 static inline void pid_reset(struct _pid *pid, int setpoint, int busy,
 			     int deadband, int integral) {
-	pid->setpoint = setpoint;
-	pid->deadband  = deadband;
+	pid->setpoint = int_tofp(setpoint);
+	pid->deadband  = int_tofp(deadband);
 	pid->integral  = int_tofp(integral);
 	pid->last_err  = int_tofp(setpoint) - int_tofp(busy);
 }
@@ -224,9 +360,9 @@ static signed int pid_calc(struct _pid *pid, int32_t busy)
 	int32_t pterm, dterm, fp_error;
 	int32_t integral_limit;
 
-	fp_error = int_tofp(pid->setpoint) - busy;
+	fp_error = pid->setpoint - busy;
 
-	if (abs(fp_error) <= int_tofp(pid->deadband))
+	if (abs(fp_error) <= pid->deadband)
 		return 0;
 
 	pterm = mul_fp(pid->p_gain, fp_error);
@@ -286,7 +422,7 @@ static inline void update_turbo_state(void)
 		 cpu->pstate.max_pstate == cpu->pstate.turbo_pstate);
 }
 
-static void intel_pstate_hwp_set(void)
+static void intel_pstate_hwp_set(const struct cpumask *cpumask)
 {
 	int min, hw_min, max, hw_max, cpu, range, adj_range;
 	u64 value, cap;
@@ -296,9 +432,7 @@ static void intel_pstate_hwp_set(void)
 	hw_max = HWP_HIGHEST_PERF(cap);
 	range = hw_max - hw_min;
 
-	get_online_cpus();
-
-	for_each_online_cpu(cpu) {
+	for_each_cpu(cpu, cpumask) {
 		rdmsrl_on_cpu(cpu, MSR_HWP_REQUEST, &value);
 		adj_range = limits->min_perf_pct * range / 100;
 		min = hw_min + adj_range;
@@ -317,7 +451,20 @@ static void intel_pstate_hwp_set(void)
 		value |= HWP_MAX_PERF(max);
 		wrmsrl_on_cpu(cpu, MSR_HWP_REQUEST, value);
 	}
+}
 
+static int intel_pstate_hwp_set_policy(struct cpufreq_policy *policy)
+{
+	if (hwp_active)
+		intel_pstate_hwp_set(policy->cpus);
+
+	return 0;
+}
+
+static void intel_pstate_hwp_set_online_cpus(void)
+{
+	get_online_cpus();
+	intel_pstate_hwp_set(cpu_online_mask);
 	put_online_cpus();
 }
 
@@ -439,7 +586,7 @@ static ssize_t store_no_turbo(struct kobject *a, struct attribute *b,
 	limits->no_turbo = clamp_t(int, input, 0, 1);
 
 	if (hwp_active)
-		intel_pstate_hwp_set();
+		intel_pstate_hwp_set_online_cpus();
 
 	return count;
 }
@@ -465,7 +612,7 @@ static ssize_t store_max_perf_pct(struct kobject *a, struct attribute *b,
 				  int_tofp(100));
 
 	if (hwp_active)
-		intel_pstate_hwp_set();
+		intel_pstate_hwp_set_online_cpus();
 	return count;
 }
 
@@ -490,7 +637,7 @@ static ssize_t store_min_perf_pct(struct kobject *a, struct attribute *b,
 				  int_tofp(100));
 
 	if (hwp_active)
-		intel_pstate_hwp_set();
+		intel_pstate_hwp_set_online_cpus();
 	return count;
 }
 
@@ -531,6 +678,9 @@ static void __init intel_pstate_sysfs_expose_params(void)
 
 static void intel_pstate_hwp_enable(struct cpudata *cpudata)
 {
+	/* First disable HWP notification interrupt as we don't process them */
+	wrmsrl_on_cpu(cpudata->cpu, MSR_HWP_INTERRUPT, 0x00);
+
 	wrmsrl_on_cpu(cpudata->cpu, MSR_PM_ENABLE, 0x1);
 }
 
@@ -558,7 +708,7 @@ static int atom_get_turbo_pstate(void)
 	return value & 0x7F;
 }
 
-static void atom_set_pstate(struct cpudata *cpudata, int pstate)
+static u64 atom_get_val(struct cpudata *cpudata, int pstate)
 {
 	u64 val;
 	int32_t vid_fp;
@@ -583,9 +733,7 @@ static void atom_set_pstate(struct cpudata *cpudata, int pstate)
 		cpu_nonscaling(cpudata->cpu);
 	}
 
-	val |= vid;
-
-	wrmsrl_on_cpu(cpudata->cpu, MSR_IA32_PERF_CTL, val);
+	return val | vid;
 }
 
 static int silvermont_get_scaling(void)
@@ -714,7 +862,7 @@ static inline int core_get_scaling(void)
 	return 100000;
 }
 
-static void core_set_pstate(struct cpudata *cpudata, int pstate)
+static u64 core_get_val(struct cpudata *cpudata, int pstate)
 {
 	u64 val;
 
@@ -722,7 +870,7 @@ static void core_set_pstate(struct cpudata *cpudata, int pstate)
 	if (limits->no_turbo && !limits->turbo_disabled)
 		val |= (u64)1 << 32;
 
-	wrmsrl_on_cpu(cpudata->cpu, MSR_IA32_PERF_CTL, val);
+	return val;
 }
 
 static int knl_get_turbo_pstate(void)
@@ -753,7 +901,7 @@ static struct cpu_defaults core_params = {
 		.get_min = core_get_min_pstate,
 		.get_turbo = core_get_turbo_pstate,
 		.get_scaling = core_get_scaling,
-		.set = core_set_pstate,
+		.get_val = core_get_val,
 		.get_target_pstate = get_target_pstate_use_performance,
 	},
 };
@@ -772,7 +920,7 @@ static struct cpu_defaults silvermont_params = {
 		.get_max_physical = atom_get_max_pstate,
 		.get_min = atom_get_min_pstate,
 		.get_turbo = atom_get_turbo_pstate,
-		.set = atom_set_pstate,
+		.get_val = atom_get_val,
 		.get_scaling = silvermont_get_scaling,
 		.get_vid = atom_get_vid,
 		.get_target_pstate = get_target_pstate_use_cpu_load,
@@ -793,7 +941,7 @@ static struct cpu_defaults airmont_params = {
 		.get_max_physical = atom_get_max_pstate,
 		.get_min = atom_get_min_pstate,
 		.get_turbo = atom_get_turbo_pstate,
-		.set = atom_set_pstate,
+		.get_val = atom_get_val,
 		.get_scaling = airmont_get_scaling,
 		.get_vid = atom_get_vid,
 		.get_target_pstate = get_target_pstate_use_cpu_load,
@@ -815,7 +963,7 @@ static struct cpu_defaults knl_params = {
 		.get_min = core_get_min_pstate,
 		.get_turbo = knl_get_turbo_pstate,
 		.get_scaling = core_get_scaling,
-		.set = core_set_pstate,
+		.get_val = core_get_val,
 		.get_target_pstate = get_target_pstate_use_performance,
 	},
 };
@@ -834,33 +982,32 @@ static void intel_pstate_get_min_max(struct cpudata *cpu, int *min, int *max)
 	 * policy, or by cpu specific default values determined through
 	 * experimentation.
 	 */
-	max_perf_adj = fp_toint(mul_fp(int_tofp(max_perf), limits->max_perf));
+	max_perf_adj = fp_toint(max_perf * limits->max_perf);
 	*max = clamp_t(int, max_perf_adj,
 			cpu->pstate.min_pstate, cpu->pstate.turbo_pstate);
 
-	min_perf = fp_toint(mul_fp(int_tofp(max_perf), limits->min_perf));
+	min_perf = fp_toint(max_perf * limits->min_perf);
 	*min = clamp_t(int, min_perf, cpu->pstate.min_pstate, max_perf);
 }
 
-static void intel_pstate_set_pstate(struct cpudata *cpu, int pstate, bool force)
+static inline void intel_pstate_record_pstate(struct cpudata *cpu, int pstate)
 {
-	int max_perf, min_perf;
-
-	if (force) {
-		update_turbo_state();
-
-		intel_pstate_get_min_max(cpu, &min_perf, &max_perf);
-
-		pstate = clamp_t(int, pstate, min_perf, max_perf);
-
-		if (pstate == cpu->pstate.current_pstate)
-			return;
-	}
 	trace_cpu_frequency(pstate * cpu->pstate.scaling, cpu->cpu);
-
 	cpu->pstate.current_pstate = pstate;
+}
+
+static void intel_pstate_set_min_pstate(struct cpudata *cpu)
+{
+	int pstate = cpu->pstate.min_pstate;
 
-	pstate_funcs.set(cpu, pstate);
+	intel_pstate_record_pstate(cpu, pstate);
+	/*
+	 * Generally, there is no guarantee that this code will always run on
+	 * the CPU being updated, so force the register update to run on the
+	 * right CPU.
+	 */
+	wrmsrl_on_cpu(cpu->cpu, MSR_IA32_PERF_CTL,
+		      pstate_funcs.get_val(cpu, pstate));
 }
 
 static void intel_pstate_get_cpu_pstates(struct cpudata *cpu)
@@ -873,7 +1020,8 @@ static void intel_pstate_get_cpu_pstates(struct cpudata *cpu)
 
 	if (pstate_funcs.get_vid)
 		pstate_funcs.get_vid(cpu);
-	intel_pstate_set_pstate(cpu, cpu->pstate.min_pstate, false);
+
+	intel_pstate_set_min_pstate(cpu);
 }
 
 static inline void intel_pstate_calc_busy(struct cpudata *cpu)
@@ -884,16 +1032,10 @@ static inline void intel_pstate_calc_busy(struct cpudata *cpu)
 	core_pct = int_tofp(sample->aperf) * int_tofp(100);
 	core_pct = div64_u64(core_pct, int_tofp(sample->mperf));
 
-	sample->freq = fp_toint(
-		mul_fp(int_tofp(
-			cpu->pstate.max_pstate_physical *
-			cpu->pstate.scaling / 100),
-			core_pct));
-
 	sample->core_pct_busy = (int32_t)core_pct;
 }
 
-static inline void intel_pstate_sample(struct cpudata *cpu)
+static inline bool intel_pstate_sample(struct cpudata *cpu, u64 time)
 {
 	u64 aperf, mperf;
 	unsigned long flags;
@@ -903,14 +1045,14 @@ static inline void intel_pstate_sample(struct cpudata *cpu)
 	rdmsrl(MSR_IA32_APERF, aperf);
 	rdmsrl(MSR_IA32_MPERF, mperf);
 	tsc = rdtsc();
-	if ((cpu->prev_mperf == mperf) || (cpu->prev_tsc == tsc)) {
+	if (cpu->prev_mperf == mperf || cpu->prev_tsc == tsc) {
 		local_irq_restore(flags);
-		return;
+		return false;
 	}
 	local_irq_restore(flags);
 
 	cpu->last_sample_time = cpu->sample.time;
-	cpu->sample.time = ktime_get();
+	cpu->sample.time = time;
 	cpu->sample.aperf = aperf;
 	cpu->sample.mperf = mperf;
 	cpu->sample.tsc =  tsc;
@@ -918,27 +1060,24 @@ static inline void intel_pstate_sample(struct cpudata *cpu)
 	cpu->sample.mperf -= cpu->prev_mperf;
 	cpu->sample.tsc -= cpu->prev_tsc;
 
-	intel_pstate_calc_busy(cpu);
-
 	cpu->prev_aperf = aperf;
 	cpu->prev_mperf = mperf;
 	cpu->prev_tsc = tsc;
+	/*
+	 * First time this function is invoked in a given cycle, all of the
+	 * previous sample data fields are equal to zero or stale and they must
+	 * be populated with meaningful numbers for things to work, so assume
+	 * that sample.time will always be reset before setting the utilization
+	 * update hook and make the caller skip the sample then.
+	 */
+	return !!cpu->last_sample_time;
 }
 
-static inline void intel_hwp_set_sample_time(struct cpudata *cpu)
-{
-	int delay;
-
-	delay = msecs_to_jiffies(50);
-	mod_timer_pinned(&cpu->timer, jiffies + delay);
-}
-
-static inline void intel_pstate_set_sample_time(struct cpudata *cpu)
+static inline int32_t get_avg_frequency(struct cpudata *cpu)
 {
-	int delay;
-
-	delay = msecs_to_jiffies(pid_params.sample_rate_ms);
-	mod_timer_pinned(&cpu->timer, jiffies + delay);
+	return fp_toint(mul_fp(cpu->sample.core_pct_busy,
+			       int_tofp(cpu->pstate.max_pstate_physical *
+						cpu->pstate.scaling / 100)));
 }
 
 static inline int32_t get_target_pstate_use_cpu_load(struct cpudata *cpu)
@@ -964,7 +1103,6 @@ static inline int32_t get_target_pstate_use_cpu_load(struct cpudata *cpu)
 	mperf = cpu->sample.mperf + delta_iowait_mperf;
 	cpu->prev_cummulative_iowait = cummulative_iowait;
 
-
 	/*
 	 * The load can be estimated as the ratio of the mperf counter
 	 * running at a constant frequency during active periods
@@ -980,8 +1118,7 @@ static inline int32_t get_target_pstate_use_cpu_load(struct cpudata *cpu)
 static inline int32_t get_target_pstate_use_performance(struct cpudata *cpu)
 {
 	int32_t core_busy, max_pstate, current_pstate, sample_ratio;
-	s64 duration_us;
-	u32 sample_time;
+	u64 duration_ns;
 
 	/*
 	 * core_busy is the ratio of actual performance to max
@@ -1000,25 +1137,41 @@ static inline int32_t get_target_pstate_use_performance(struct cpudata *cpu)
 	core_busy = mul_fp(core_busy, div_fp(max_pstate, current_pstate));
 
 	/*
-	 * Since we have a deferred timer, it will not fire unless
-	 * we are in C0.  So, determine if the actual elapsed time
-	 * is significantly greater (3x) than our sample interval.  If it
-	 * is, then we were idle for a long enough period of time
-	 * to adjust our busyness.
+	 * Since our utilization update callback will not run unless we are
+	 * in C0, check if the actual elapsed time is significantly greater (3x)
+	 * than our sample interval.  If it is, then we were idle for a long
+	 * enough period of time to adjust our busyness.
 	 */
-	sample_time = pid_params.sample_rate_ms  * USEC_PER_MSEC;
-	duration_us = ktime_us_delta(cpu->sample.time,
-				     cpu->last_sample_time);
-	if (duration_us > sample_time * 3) {
-		sample_ratio = div_fp(int_tofp(sample_time),
-				      int_tofp(duration_us));
+	duration_ns = cpu->sample.time - cpu->last_sample_time;
+	if ((s64)duration_ns > pid_params.sample_rate_ns * 3) {
+		sample_ratio = div_fp(int_tofp(pid_params.sample_rate_ns),
+				      int_tofp(duration_ns));
 		core_busy = mul_fp(core_busy, sample_ratio);
+	} else {
+		sample_ratio = div_fp(100 * cpu->sample.mperf, cpu->sample.tsc);
+		if (sample_ratio < int_tofp(1))
+			core_busy = 0;
 	}
 
 	cpu->sample.busy_scaled = core_busy;
 	return cpu->pstate.current_pstate - pid_calc(&cpu->pid, core_busy);
 }
 
+static inline void intel_pstate_update_pstate(struct cpudata *cpu, int pstate)
+{
+	int max_perf, min_perf;
+
+	update_turbo_state();
+
+	intel_pstate_get_min_max(cpu, &min_perf, &max_perf);
+	pstate = clamp_t(int, pstate, min_perf, max_perf);
+	if (pstate == cpu->pstate.current_pstate)
+		return;
+
+	intel_pstate_record_pstate(cpu, pstate);
+	wrmsrl(MSR_IA32_PERF_CTL, pstate_funcs.get_val(cpu, pstate));
+}
+
 static inline void intel_pstate_adjust_busy_pstate(struct cpudata *cpu)
 {
 	int from, target_pstate;
@@ -1028,7 +1181,7 @@ static inline void intel_pstate_adjust_busy_pstate(struct cpudata *cpu)
 
 	target_pstate = pstate_funcs.get_target_pstate(cpu);
 
-	intel_pstate_set_pstate(cpu, target_pstate, true);
+	intel_pstate_update_pstate(cpu, target_pstate);
 
 	sample = &cpu->sample;
 	trace_pstate_sample(fp_toint(sample->core_pct_busy),
@@ -1038,26 +1191,24 @@ static inline void intel_pstate_adjust_busy_pstate(struct cpudata *cpu)
 		sample->mperf,
 		sample->aperf,
 		sample->tsc,
-		sample->freq);
-}
-
-static void intel_hwp_timer_func(unsigned long __data)
-{
-	struct cpudata *cpu = (struct cpudata *) __data;
-
-	intel_pstate_sample(cpu);
-	intel_hwp_set_sample_time(cpu);
+		get_avg_frequency(cpu));
 }
 
-static void intel_pstate_timer_func(unsigned long __data)
+static void intel_pstate_update_util(struct update_util_data *data, u64 time,
+				     unsigned long util, unsigned long max)
 {
-	struct cpudata *cpu = (struct cpudata *) __data;
-
-	intel_pstate_sample(cpu);
+	struct cpudata *cpu = container_of(data, struct cpudata, update_util);
+	u64 delta_ns = time - cpu->sample.time;
 
-	intel_pstate_adjust_busy_pstate(cpu);
+	if ((s64)delta_ns >= pid_params.sample_rate_ns) {
+		bool sample_taken = intel_pstate_sample(cpu, time);
 
-	intel_pstate_set_sample_time(cpu);
+		if (sample_taken) {
+			intel_pstate_calc_busy(cpu);
+			if (!hwp_active)
+				intel_pstate_adjust_busy_pstate(cpu);
+		}
+	}
 }
 
 #define ICPU(model, policy) \
@@ -1105,24 +1256,17 @@ static int intel_pstate_init_cpu(unsigned int cpunum)
 
 	cpu->cpu = cpunum;
 
-	if (hwp_active)
+	if (hwp_active) {
 		intel_pstate_hwp_enable(cpu);
+		pid_params.sample_rate_ms = 50;
+		pid_params.sample_rate_ns = 50 * NSEC_PER_MSEC;
+	}
 
 	intel_pstate_get_cpu_pstates(cpu);
 
-	init_timer_deferrable(&cpu->timer);
-	cpu->timer.data = (unsigned long)cpu;
-	cpu->timer.expires = jiffies + HZ/100;
-
-	if (!hwp_active)
-		cpu->timer.function = intel_pstate_timer_func;
-	else
-		cpu->timer.function = intel_hwp_timer_func;
-
 	intel_pstate_busy_pid_reset(cpu);
-	intel_pstate_sample(cpu);
 
-	add_timer_on(&cpu->timer, cpunum);
+	cpu->update_util.func = intel_pstate_update_util;
 
 	pr_debug("intel_pstate: controlling: cpu %d\n", cpunum);
 
@@ -1138,7 +1282,36 @@ static unsigned int intel_pstate_get(unsigned int cpu_num)
 	if (!cpu)
 		return 0;
 	sample = &cpu->sample;
-	return sample->freq;
+	return get_avg_frequency(cpu);
+}
+
+static void intel_pstate_set_update_util_hook(unsigned int cpu_num)
+{
+	struct cpudata *cpu = all_cpu_data[cpu_num];
+
+	/* Prevent intel_pstate_update_util() from using stale data. */
+	cpu->sample.time = 0;
+	cpufreq_set_update_util_data(cpu_num, &cpu->update_util);
+}
+
+static void intel_pstate_clear_update_util_hook(unsigned int cpu)
+{
+	cpufreq_set_update_util_data(cpu, NULL);
+	synchronize_sched();
+}
+
+static void intel_pstate_set_performance_limits(struct perf_limits *limits)
+{
+	limits->no_turbo = 0;
+	limits->turbo_disabled = 0;
+	limits->max_perf_pct = 100;
+	limits->max_perf = int_tofp(1);
+	limits->min_perf_pct = 100;
+	limits->min_perf = int_tofp(1);
+	limits->max_policy_pct = 100;
+	limits->max_sysfs_pct = 100;
+	limits->min_policy_pct = 0;
+	limits->min_sysfs_pct = 0;
 }
 
 static int intel_pstate_set_policy(struct cpufreq_policy *policy)
@@ -1146,17 +1319,20 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)
 	if (!policy->cpuinfo.max_freq)
 		return -ENODEV;
 
-	if (policy->policy == CPUFREQ_POLICY_PERFORMANCE &&
-	    policy->max >= policy->cpuinfo.max_freq) {
-		pr_debug("intel_pstate: set performance\n");
+	intel_pstate_clear_update_util_hook(policy->cpu);
+
+	if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) {
 		limits = &performance_limits;
-		if (hwp_active)
-			intel_pstate_hwp_set();
-		return 0;
+		if (policy->max >= policy->cpuinfo.max_freq) {
+			pr_debug("intel_pstate: set performance\n");
+			intel_pstate_set_performance_limits(limits);
+			goto out;
+		}
+	} else {
+		pr_debug("intel_pstate: set powersave\n");
+		limits = &powersave_limits;
 	}
 
-	pr_debug("intel_pstate: set powersave\n");
-	limits = &powersave_limits;
 	limits->min_policy_pct = (policy->min * 100) / policy->cpuinfo.max_freq;
 	limits->min_policy_pct = clamp_t(int, limits->min_policy_pct, 0 , 100);
 	limits->max_policy_pct = DIV_ROUND_UP(policy->max * 100,
@@ -1182,8 +1358,10 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)
 	limits->max_perf = div_fp(int_tofp(limits->max_perf_pct),
 				  int_tofp(100));
 
-	if (hwp_active)
-		intel_pstate_hwp_set();
+ out:
+	intel_pstate_set_update_util_hook(policy->cpu);
+
+	intel_pstate_hwp_set_policy(policy);
 
 	return 0;
 }
@@ -1206,11 +1384,12 @@ static void intel_pstate_stop_cpu(struct cpufreq_policy *policy)
 
 	pr_debug("intel_pstate: CPU %d exiting\n", cpu_num);
 
-	del_timer_sync(&all_cpu_data[cpu_num]->timer);
+	intel_pstate_clear_update_util_hook(cpu_num);
+
 	if (hwp_active)
 		return;
 
-	intel_pstate_set_pstate(cpu, cpu->pstate.min_pstate, false);
+	intel_pstate_set_min_pstate(cpu);
 }
 
 static int intel_pstate_cpu_init(struct cpufreq_policy *policy)
@@ -1246,6 +1425,7 @@ static struct cpufreq_driver intel_pstate_driver = {
 	.flags		= CPUFREQ_CONST_LOOPS,
 	.verify		= intel_pstate_verify_policy,
 	.setpolicy	= intel_pstate_set_policy,
+	.resume		= intel_pstate_hwp_set_policy,
 	.get		= intel_pstate_get,
 	.init		= intel_pstate_cpu_init,
 	.stop_cpu	= intel_pstate_stop_cpu,
@@ -1270,6 +1450,7 @@ static int intel_pstate_msrs_not_valid(void)
 static void copy_pid_params(struct pstate_adjust_policy *policy)
 {
 	pid_params.sample_rate_ms = policy->sample_rate_ms;
+	pid_params.sample_rate_ns = pid_params.sample_rate_ms * NSEC_PER_MSEC;
 	pid_params.p_gain_pct = policy->p_gain_pct;
 	pid_params.i_gain_pct = policy->i_gain_pct;
 	pid_params.d_gain_pct = policy->d_gain_pct;
@@ -1284,7 +1465,7 @@ static void copy_cpu_funcs(struct pstate_funcs *funcs)
 	pstate_funcs.get_min   = funcs->get_min;
 	pstate_funcs.get_turbo = funcs->get_turbo;
 	pstate_funcs.get_scaling = funcs->get_scaling;
-	pstate_funcs.set       = funcs->set;
+	pstate_funcs.get_val   = funcs->get_val;
 	pstate_funcs.get_vid   = funcs->get_vid;
 	pstate_funcs.get_target_pstate = funcs->get_target_pstate;
 
@@ -1407,6 +1588,11 @@ static inline bool intel_pstate_platform_pwr_mgmt_exists(void) { return false; }
 static inline bool intel_pstate_has_acpi_ppc(void) { return false; }
 #endif /* CONFIG_ACPI */
 
+static const struct x86_cpu_id hwp_support_ids[] __initconst = {
+	{ X86_VENDOR_INTEL, 6, X86_MODEL_ANY, X86_FEATURE_HWP },
+	{}
+};
+
 static int __init intel_pstate_init(void)
 {
 	int cpu, rc = 0;
@@ -1416,17 +1602,16 @@ static int __init intel_pstate_init(void)
 	if (no_load)
 		return -ENODEV;
 
+	if (x86_match_cpu(hwp_support_ids) && !no_hwp) {
+		copy_cpu_funcs(&core_params.funcs);
+		hwp_active++;
+		goto hwp_cpu_matched;
+	}
+
 	id = x86_match_cpu(intel_pstate_cpu_ids);
 	if (!id)
 		return -ENODEV;
 
-	/*
-	 * The Intel pstate driver will be ignored if the platform
-	 * firmware has its own power management modes.
-	 */
-	if (intel_pstate_platform_pwr_mgmt_exists())
-		return -ENODEV;
-
 	cpu_def = (struct cpu_defaults *)id->driver_data;
 
 	copy_pid_params(&cpu_def->pid_policy);
@@ -1435,17 +1620,20 @@ static int __init intel_pstate_init(void)
 	if (intel_pstate_msrs_not_valid())
 		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())
+		return -ENODEV;
+
 	pr_info("Intel P-state driver initializing.\n");
 
 	all_cpu_data = vzalloc(sizeof(void *) * num_possible_cpus());
 	if (!all_cpu_data)
 		return -ENOMEM;
 
-	if (static_cpu_has_safe(X86_FEATURE_HWP) && !no_hwp) {
-		pr_info("intel_pstate: HWP enabled\n");
-		hwp_active++;
-	}
-
 	if (!hwp_active && hwp_only)
 		goto out;
 
@@ -1456,12 +1644,15 @@ static int __init intel_pstate_init(void)
 	intel_pstate_debug_expose_params();
 	intel_pstate_sysfs_expose_params();
 
+	if (hwp_active)
+		pr_info("intel_pstate: HWP enabled\n");
+
 	return rc;
 out:
 	get_online_cpus();
 	for_each_online_cpu(cpu) {
 		if (all_cpu_data[cpu]) {
-			del_timer_sync(&all_cpu_data[cpu]->timer);
+			intel_pstate_clear_update_util_hook(cpu);
 			kfree(all_cpu_data[cpu]);
 		}
 	}