1 files changed, 767 insertions, 0 deletions

diff --git a/drivers/thermal/intel/intel_powerclamp.c b/drivers/thermal/intel/intel_powerclamp.c
new file mode 100644
index 000000000..2f4cbfdf2
--- /dev/null
+++ b/drivers/thermal/intel/intel_powerclamp.c
@@ -0,0 +1,767 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * intel_powerclamp.c - package c-state idle injection
+ *
+ * Copyright (c) 2012, Intel Corporation.
+ *
+ * Authors:
+ *     Arjan van de Ven <arjan@linux.intel.com>
+ *     Jacob Pan <jacob.jun.pan@linux.intel.com>
+ *
+ *	TODO:
+ *           1. better handle wakeup from external interrupts, currently a fixed
+ *              compensation is added to clamping duration when excessive amount
+ *              of wakeups are observed during idle time. the reason is that in
+ *              case of external interrupts without need for ack, clamping down
+ *              cpu in non-irq context does not reduce irq. for majority of the
+ *              cases, clamping down cpu does help reduce irq as well, we should
+ *              be able to differentiate the two cases and give a quantitative
+ *              solution for the irqs that we can control. perhaps based on
+ *              get_cpu_iowait_time_us()
+ *
+ *	     2. synchronization with other hw blocks
+ */
+
+#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/kthread.h>
+#include <linux/cpu.h>
+#include <linux/thermal.h>
+#include <linux/slab.h>
+#include <linux/tick.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/sched/rt.h>
+#include <uapi/linux/sched/types.h>
+
+#include <asm/nmi.h>
+#include <asm/msr.h>
+#include <asm/mwait.h>
+#include <asm/cpu_device_id.h>
+#include <asm/hardirq.h>
+
+#define MAX_TARGET_RATIO (50U)
+/* For each undisturbed clamping period (no extra wake ups during idle time),
+ * we increment the confidence counter for the given target ratio.
+ * CONFIDENCE_OK defines the level where runtime calibration results are
+ * valid.
+ */
+#define CONFIDENCE_OK (3)
+/* Default idle injection duration, driver adjust sleep time to meet target
+ * idle ratio. Similar to frequency modulation.
+ */
+#define DEFAULT_DURATION_JIFFIES (6)
+
+static unsigned int target_mwait;
+static struct dentry *debug_dir;
+static bool poll_pkg_cstate_enable;
+
+/* user selected target */
+static unsigned int set_target_ratio;
+static unsigned int current_ratio;
+static bool should_skip;
+
+static unsigned int control_cpu; /* The cpu assigned to collect stat and update
+				  * control parameters. default to BSP but BSP
+				  * can be offlined.
+				  */
+static bool clamping;
+
+struct powerclamp_worker_data {
+	struct kthread_worker *worker;
+	struct kthread_work balancing_work;
+	struct kthread_delayed_work idle_injection_work;
+	unsigned int cpu;
+	unsigned int count;
+	unsigned int guard;
+	unsigned int window_size_now;
+	unsigned int target_ratio;
+	unsigned int duration_jiffies;
+	bool clamping;
+};
+
+static struct powerclamp_worker_data __percpu *worker_data;
+static struct thermal_cooling_device *cooling_dev;
+static unsigned long *cpu_clamping_mask;  /* bit map for tracking per cpu
+					   * clamping kthread worker
+					   */
+
+static unsigned int duration;
+static unsigned int pkg_cstate_ratio_cur;
+static unsigned int window_size;
+
+static int duration_set(const char *arg, const struct kernel_param *kp)
+{
+	int ret = 0;
+	unsigned long new_duration;
+
+	ret = kstrtoul(arg, 10, &new_duration);
+	if (ret)
+		goto exit;
+	if (new_duration > 25 || new_duration < 6) {
+		pr_err("Out of recommended range %lu, between 6-25ms\n",
+			new_duration);
+		ret = -EINVAL;
+	}
+
+	duration = clamp(new_duration, 6ul, 25ul);
+	smp_mb();
+
+exit:
+
+	return ret;
+}
+
+static const struct kernel_param_ops duration_ops = {
+	.set = duration_set,
+	.get = param_get_int,
+};
+
+
+module_param_cb(duration, &duration_ops, &duration, 0644);
+MODULE_PARM_DESC(duration, "forced idle time for each attempt in msec.");
+
+struct powerclamp_calibration_data {
+	unsigned long confidence;  /* used for calibration, basically a counter
+				    * gets incremented each time a clamping
+				    * period is completed without extra wakeups
+				    * once that counter is reached given level,
+				    * compensation is deemed usable.
+				    */
+	unsigned long steady_comp; /* steady state compensation used when
+				    * no extra wakeups occurred.
+				    */
+	unsigned long dynamic_comp; /* compensate excessive wakeup from idle
+				     * mostly from external interrupts.
+				     */
+};
+
+static struct powerclamp_calibration_data cal_data[MAX_TARGET_RATIO];
+
+static int window_size_set(const char *arg, const struct kernel_param *kp)
+{
+	int ret = 0;
+	unsigned long new_window_size;
+
+	ret = kstrtoul(arg, 10, &new_window_size);
+	if (ret)
+		goto exit_win;
+	if (new_window_size > 10 || new_window_size < 2) {
+		pr_err("Out of recommended window size %lu, between 2-10\n",
+			new_window_size);
+		ret = -EINVAL;
+	}
+
+	window_size = clamp(new_window_size, 2ul, 10ul);
+	smp_mb();
+
+exit_win:
+
+	return ret;
+}
+
+static const struct kernel_param_ops window_size_ops = {
+	.set = window_size_set,
+	.get = param_get_int,
+};
+
+module_param_cb(window_size, &window_size_ops, &window_size, 0644);
+MODULE_PARM_DESC(window_size, "sliding window in number of clamping cycles\n"
+	"\tpowerclamp controls idle ratio within this window. larger\n"
+	"\twindow size results in slower response time but more smooth\n"
+	"\tclamping results. default to 2.");
+
+static void find_target_mwait(void)
+{
+	unsigned int eax, ebx, ecx, edx;
+	unsigned int highest_cstate = 0;
+	unsigned int highest_subcstate = 0;
+	int i;
+
+	if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
+		return;
+
+	cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &edx);
+
+	if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
+	    !(ecx & CPUID5_ECX_INTERRUPT_BREAK))
+		return;
+
+	edx >>= MWAIT_SUBSTATE_SIZE;
+	for (i = 0; i < 7 && edx; i++, edx >>= MWAIT_SUBSTATE_SIZE) {
+		if (edx & MWAIT_SUBSTATE_MASK) {
+			highest_cstate = i;
+			highest_subcstate = edx & MWAIT_SUBSTATE_MASK;
+		}
+	}
+	target_mwait = (highest_cstate << MWAIT_SUBSTATE_SIZE) |
+		(highest_subcstate - 1);
+
+}
+
+struct pkg_cstate_info {
+	bool skip;
+	int msr_index;
+	int cstate_id;
+};
+
+#define PKG_CSTATE_INIT(id) {				\
+		.msr_index = MSR_PKG_C##id##_RESIDENCY, \
+		.cstate_id = id				\
+			}
+
+static struct pkg_cstate_info pkg_cstates[] = {
+	PKG_CSTATE_INIT(2),
+	PKG_CSTATE_INIT(3),
+	PKG_CSTATE_INIT(6),
+	PKG_CSTATE_INIT(7),
+	PKG_CSTATE_INIT(8),
+	PKG_CSTATE_INIT(9),
+	PKG_CSTATE_INIT(10),
+	{NULL},
+};
+
+static bool has_pkg_state_counter(void)
+{
+	u64 val;
+	struct pkg_cstate_info *info = pkg_cstates;
+
+	/* check if any one of the counter msrs exists */
+	while (info->msr_index) {
+		if (!rdmsrl_safe(info->msr_index, &val))
+			return true;
+		info++;
+	}
+
+	return false;
+}
+
+static u64 pkg_state_counter(void)
+{
+	u64 val;
+	u64 count = 0;
+	struct pkg_cstate_info *info = pkg_cstates;
+
+	while (info->msr_index) {
+		if (!info->skip) {
+			if (!rdmsrl_safe(info->msr_index, &val))
+				count += val;
+			else
+				info->skip = true;
+		}
+		info++;
+	}
+
+	return count;
+}
+
+static unsigned int get_compensation(int ratio)
+{
+	unsigned int comp = 0;
+
+	if (!poll_pkg_cstate_enable)
+		return 0;
+
+	/* we only use compensation if all adjacent ones are good */
+	if (ratio == 1 &&
+		cal_data[ratio].confidence >= CONFIDENCE_OK &&
+		cal_data[ratio + 1].confidence >= CONFIDENCE_OK &&
+		cal_data[ratio + 2].confidence >= CONFIDENCE_OK) {
+		comp = (cal_data[ratio].steady_comp +
+			cal_data[ratio + 1].steady_comp +
+			cal_data[ratio + 2].steady_comp) / 3;
+	} else if (ratio == MAX_TARGET_RATIO - 1 &&
+		cal_data[ratio].confidence >= CONFIDENCE_OK &&
+		cal_data[ratio - 1].confidence >= CONFIDENCE_OK &&
+		cal_data[ratio - 2].confidence >= CONFIDENCE_OK) {
+		comp = (cal_data[ratio].steady_comp +
+			cal_data[ratio - 1].steady_comp +
+			cal_data[ratio - 2].steady_comp) / 3;
+	} else if (cal_data[ratio].confidence >= CONFIDENCE_OK &&
+		cal_data[ratio - 1].confidence >= CONFIDENCE_OK &&
+		cal_data[ratio + 1].confidence >= CONFIDENCE_OK) {
+		comp = (cal_data[ratio].steady_comp +
+			cal_data[ratio - 1].steady_comp +
+			cal_data[ratio + 1].steady_comp) / 3;
+	}
+
+	/* do not exceed limit */
+	if (comp + ratio >= MAX_TARGET_RATIO)
+		comp = MAX_TARGET_RATIO - ratio - 1;
+
+	return comp;
+}
+
+static void adjust_compensation(int target_ratio, unsigned int win)
+{
+	int delta;
+	struct powerclamp_calibration_data *d = &cal_data[target_ratio];
+
+	/*
+	 * adjust compensations if confidence level has not been reached.
+	 */
+	if (d->confidence >= CONFIDENCE_OK)
+		return;
+
+	delta = set_target_ratio - current_ratio;
+	/* filter out bad data */
+	if (delta >= 0 && delta <= (1+target_ratio/10)) {
+		if (d->steady_comp)
+			d->steady_comp =
+				roundup(delta+d->steady_comp, 2)/2;
+		else
+			d->steady_comp = delta;
+		d->confidence++;
+	}
+}
+
+static bool powerclamp_adjust_controls(unsigned int target_ratio,
+				unsigned int guard, unsigned int win)
+{
+	static u64 msr_last, tsc_last;
+	u64 msr_now, tsc_now;
+	u64 val64;
+
+	/* check result for the last window */
+	msr_now = pkg_state_counter();
+	tsc_now = rdtsc();
+
+	/* calculate pkg cstate vs tsc ratio */
+	if (!msr_last || !tsc_last)
+		current_ratio = 1;
+	else if (tsc_now-tsc_last) {
+		val64 = 100*(msr_now-msr_last);
+		do_div(val64, (tsc_now-tsc_last));
+		current_ratio = val64;
+	}
+
+	/* update record */
+	msr_last = msr_now;
+	tsc_last = tsc_now;
+
+	adjust_compensation(target_ratio, win);
+
+	/* if we are above target+guard, skip */
+	return set_target_ratio + guard <= current_ratio;
+}
+
+static void clamp_balancing_func(struct kthread_work *work)
+{
+	struct powerclamp_worker_data *w_data;
+	int sleeptime;
+	unsigned long target_jiffies;
+	unsigned int compensated_ratio;
+	int interval; /* jiffies to sleep for each attempt */
+
+	w_data = container_of(work, struct powerclamp_worker_data,
+			      balancing_work);
+
+	/*
+	 * make sure user selected ratio does not take effect until
+	 * the next round. adjust target_ratio if user has changed
+	 * target such that we can converge quickly.
+	 */
+	w_data->target_ratio = READ_ONCE(set_target_ratio);
+	w_data->guard = 1 + w_data->target_ratio / 20;
+	w_data->window_size_now = window_size;
+	w_data->duration_jiffies = msecs_to_jiffies(duration);
+	w_data->count++;
+
+	/*
+	 * systems may have different ability to enter package level
+	 * c-states, thus we need to compensate the injected idle ratio
+	 * to achieve the actual target reported by the HW.
+	 */
+	compensated_ratio = w_data->target_ratio +
+		get_compensation(w_data->target_ratio);
+	if (compensated_ratio <= 0)
+		compensated_ratio = 1;
+	interval = w_data->duration_jiffies * 100 / compensated_ratio;
+
+	/* align idle time */
+	target_jiffies = roundup(jiffies, interval);
+	sleeptime = target_jiffies - jiffies;
+	if (sleeptime <= 0)
+		sleeptime = 1;
+
+	if (clamping && w_data->clamping && cpu_online(w_data->cpu))
+		kthread_queue_delayed_work(w_data->worker,
+					   &w_data->idle_injection_work,
+					   sleeptime);
+}
+
+static void clamp_idle_injection_func(struct kthread_work *work)
+{
+	struct powerclamp_worker_data *w_data;
+
+	w_data = container_of(work, struct powerclamp_worker_data,
+			      idle_injection_work.work);
+
+	/*
+	 * only elected controlling cpu can collect stats and update
+	 * control parameters.
+	 */
+	if (w_data->cpu == control_cpu &&
+	    !(w_data->count % w_data->window_size_now)) {
+		should_skip =
+			powerclamp_adjust_controls(w_data->target_ratio,
+						   w_data->guard,
+						   w_data->window_size_now);
+		smp_mb();
+	}
+
+	if (should_skip)
+		goto balance;
+
+	play_idle(jiffies_to_usecs(w_data->duration_jiffies));
+
+balance:
+	if (clamping && w_data->clamping && cpu_online(w_data->cpu))
+		kthread_queue_work(w_data->worker, &w_data->balancing_work);
+}
+
+/*
+ * 1 HZ polling while clamping is active, useful for userspace
+ * to monitor actual idle ratio.
+ */
+static void poll_pkg_cstate(struct work_struct *dummy);
+static DECLARE_DELAYED_WORK(poll_pkg_cstate_work, poll_pkg_cstate);
+static void poll_pkg_cstate(struct work_struct *dummy)
+{
+	static u64 msr_last;
+	static u64 tsc_last;
+
+	u64 msr_now;
+	u64 tsc_now;
+	u64 val64;
+
+	msr_now = pkg_state_counter();
+	tsc_now = rdtsc();
+
+	/* calculate pkg cstate vs tsc ratio */
+	if (!msr_last || !tsc_last)
+		pkg_cstate_ratio_cur = 1;
+	else {
+		if (tsc_now - tsc_last) {
+			val64 = 100 * (msr_now - msr_last);
+			do_div(val64, (tsc_now - tsc_last));
+			pkg_cstate_ratio_cur = val64;
+		}
+	}
+
+	/* update record */
+	msr_last = msr_now;
+	tsc_last = tsc_now;
+
+	if (true == clamping)
+		schedule_delayed_work(&poll_pkg_cstate_work, HZ);
+}
+
+static void start_power_clamp_worker(unsigned long cpu)
+{
+	struct powerclamp_worker_data *w_data = per_cpu_ptr(worker_data, cpu);
+	struct kthread_worker *worker;
+
+	worker = kthread_create_worker_on_cpu(cpu, 0, "kidle_inj/%ld", cpu);
+	if (IS_ERR(worker))
+		return;
+
+	w_data->worker = worker;
+	w_data->count = 0;
+	w_data->cpu = cpu;
+	w_data->clamping = true;
+	set_bit(cpu, cpu_clamping_mask);
+	sched_set_fifo(worker->task);
+	kthread_init_work(&w_data->balancing_work, clamp_balancing_func);
+	kthread_init_delayed_work(&w_data->idle_injection_work,
+				  clamp_idle_injection_func);
+	kthread_queue_work(w_data->worker, &w_data->balancing_work);
+}
+
+static void stop_power_clamp_worker(unsigned long cpu)
+{
+	struct powerclamp_worker_data *w_data = per_cpu_ptr(worker_data, cpu);
+
+	if (!w_data->worker)
+		return;
+
+	w_data->clamping = false;
+	/*
+	 * Make sure that all works that get queued after this point see
+	 * the clamping disabled. The counter part is not needed because
+	 * there is an implicit memory barrier when the queued work
+	 * is proceed.
+	 */
+	smp_wmb();
+	kthread_cancel_work_sync(&w_data->balancing_work);
+	kthread_cancel_delayed_work_sync(&w_data->idle_injection_work);
+	/*
+	 * The balancing work still might be queued here because
+	 * the handling of the "clapming" variable, cancel, and queue
+	 * operations are not synchronized via a lock. But it is not
+	 * a big deal. The balancing work is fast and destroy kthread
+	 * will wait for it.
+	 */
+	clear_bit(w_data->cpu, cpu_clamping_mask);
+	kthread_destroy_worker(w_data->worker);
+
+	w_data->worker = NULL;
+}
+
+static int start_power_clamp(void)
+{
+	unsigned long cpu;
+
+	set_target_ratio = clamp(set_target_ratio, 0U, MAX_TARGET_RATIO - 1);
+	/* prevent cpu hotplug */
+	cpus_read_lock();
+
+	/* prefer BSP */
+	control_cpu = cpumask_first(cpu_online_mask);
+
+	clamping = true;
+	if (poll_pkg_cstate_enable)
+		schedule_delayed_work(&poll_pkg_cstate_work, 0);
+
+	/* start one kthread worker per online cpu */
+	for_each_online_cpu(cpu) {
+		start_power_clamp_worker(cpu);
+	}
+	cpus_read_unlock();
+
+	return 0;
+}
+
+static void end_power_clamp(void)
+{
+	int i;
+
+	/*
+	 * Block requeuing in all the kthread workers. They will flush and
+	 * stop faster.
+	 */
+	clamping = false;
+	for_each_set_bit(i, cpu_clamping_mask, num_possible_cpus()) {
+		pr_debug("clamping worker for cpu %d alive, destroy\n", i);
+		stop_power_clamp_worker(i);
+	}
+}
+
+static int powerclamp_cpu_online(unsigned int cpu)
+{
+	if (clamping == false)
+		return 0;
+	start_power_clamp_worker(cpu);
+	/* prefer BSP as controlling CPU */
+	if (cpu == 0) {
+		control_cpu = 0;
+		smp_mb();
+	}
+	return 0;
+}
+
+static int powerclamp_cpu_predown(unsigned int cpu)
+{
+	if (clamping == false)
+		return 0;
+
+	stop_power_clamp_worker(cpu);
+	if (cpu != control_cpu)
+		return 0;
+
+	control_cpu = cpumask_first(cpu_online_mask);
+	if (control_cpu == cpu)
+		control_cpu = cpumask_next(cpu, cpu_online_mask);
+	smp_mb();
+	return 0;
+}
+
+static int powerclamp_get_max_state(struct thermal_cooling_device *cdev,
+				 unsigned long *state)
+{
+	*state = MAX_TARGET_RATIO;
+
+	return 0;
+}
+
+static int powerclamp_get_cur_state(struct thermal_cooling_device *cdev,
+				 unsigned long *state)
+{
+	if (clamping) {
+		if (poll_pkg_cstate_enable)
+			*state = pkg_cstate_ratio_cur;
+		else
+			*state = set_target_ratio;
+	} else {
+		/* to save power, do not poll idle ratio while not clamping */
+		*state = -1; /* indicates invalid state */
+	}
+
+	return 0;
+}
+
+static int powerclamp_set_cur_state(struct thermal_cooling_device *cdev,
+				 unsigned long new_target_ratio)
+{
+	int ret = 0;
+
+	new_target_ratio = clamp(new_target_ratio, 0UL,
+				(unsigned long) (MAX_TARGET_RATIO-1));
+	if (set_target_ratio == 0 && new_target_ratio > 0) {
+		pr_info("Start idle injection to reduce power\n");
+		set_target_ratio = new_target_ratio;
+		ret = start_power_clamp();
+		goto exit_set;
+	} else	if (set_target_ratio > 0 && new_target_ratio == 0) {
+		pr_info("Stop forced idle injection\n");
+		end_power_clamp();
+		set_target_ratio = 0;
+	} else	/* adjust currently running */ {
+		set_target_ratio = new_target_ratio;
+		/* make new set_target_ratio visible to other cpus */
+		smp_mb();
+	}
+
+exit_set:
+	return ret;
+}
+
+/* bind to generic thermal layer as cooling device*/
+static const struct thermal_cooling_device_ops powerclamp_cooling_ops = {
+	.get_max_state = powerclamp_get_max_state,
+	.get_cur_state = powerclamp_get_cur_state,
+	.set_cur_state = powerclamp_set_cur_state,
+};
+
+static const struct x86_cpu_id __initconst intel_powerclamp_ids[] = {
+	X86_MATCH_VENDOR_FEATURE(INTEL, X86_FEATURE_MWAIT, NULL),
+	{}
+};
+MODULE_DEVICE_TABLE(x86cpu, intel_powerclamp_ids);
+
+static int __init powerclamp_probe(void)
+{
+
+	if (!x86_match_cpu(intel_powerclamp_ids)) {
+		pr_err("CPU does not support MWAIT\n");
+		return -ENODEV;
+	}
+
+	/* The goal for idle time alignment is to achieve package cstate. */
+	if (!has_pkg_state_counter()) {
+		pr_info("No package C-state available\n");
+		return -ENODEV;
+	}
+
+	/* find the deepest mwait value */
+	find_target_mwait();
+
+	return 0;
+}
+
+static int powerclamp_debug_show(struct seq_file *m, void *unused)
+{
+	int i = 0;
+
+	seq_printf(m, "controlling cpu: %d\n", control_cpu);
+	seq_printf(m, "pct confidence steady dynamic (compensation)\n");
+	for (i = 0; i < MAX_TARGET_RATIO; i++) {
+		seq_printf(m, "%d\t%lu\t%lu\t%lu\n",
+			i,
+			cal_data[i].confidence,
+			cal_data[i].steady_comp,
+			cal_data[i].dynamic_comp);
+	}
+
+	return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(powerclamp_debug);
+
+static inline void powerclamp_create_debug_files(void)
+{
+	debug_dir = debugfs_create_dir("intel_powerclamp", NULL);
+
+	debugfs_create_file("powerclamp_calib", S_IRUGO, debug_dir, cal_data,
+			    &powerclamp_debug_fops);
+}
+
+static enum cpuhp_state hp_state;
+
+static int __init powerclamp_init(void)
+{
+	int retval;
+
+	cpu_clamping_mask = bitmap_zalloc(num_possible_cpus(), GFP_KERNEL);
+	if (!cpu_clamping_mask)
+		return -ENOMEM;
+
+	/* probe cpu features and ids here */
+	retval = powerclamp_probe();
+	if (retval)
+		goto exit_free;
+
+	/* set default limit, maybe adjusted during runtime based on feedback */
+	window_size = 2;
+	retval = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
+					   "thermal/intel_powerclamp:online",
+					   powerclamp_cpu_online,
+					   powerclamp_cpu_predown);
+	if (retval < 0)
+		goto exit_free;
+
+	hp_state = retval;
+
+	worker_data = alloc_percpu(struct powerclamp_worker_data);
+	if (!worker_data) {
+		retval = -ENOMEM;
+		goto exit_unregister;
+	}
+
+	if (topology_max_packages() == 1 && topology_max_die_per_package() == 1)
+		poll_pkg_cstate_enable = true;
+
+	cooling_dev = thermal_cooling_device_register("intel_powerclamp", NULL,
+						&powerclamp_cooling_ops);
+	if (IS_ERR(cooling_dev)) {
+		retval = -ENODEV;
+		goto exit_free_thread;
+	}
+
+	if (!duration)
+		duration = jiffies_to_msecs(DEFAULT_DURATION_JIFFIES);
+
+	powerclamp_create_debug_files();
+
+	return 0;
+
+exit_free_thread:
+	free_percpu(worker_data);
+exit_unregister:
+	cpuhp_remove_state_nocalls(hp_state);
+exit_free:
+	bitmap_free(cpu_clamping_mask);
+	return retval;
+}
+module_init(powerclamp_init);
+
+static void __exit powerclamp_exit(void)
+{
+	end_power_clamp();
+	cpuhp_remove_state_nocalls(hp_state);
+	free_percpu(worker_data);
+	thermal_cooling_device_unregister(cooling_dev);
+	bitmap_free(cpu_clamping_mask);
+
+	cancel_delayed_work_sync(&poll_pkg_cstate_work);
+	debugfs_remove_recursive(debug_dir);
+}
+module_exit(powerclamp_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>");
+MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@linux.intel.com>");
+MODULE_DESCRIPTION("Package Level C-state Idle Injection for Intel CPUs");