drivers/cpuidle/cpuidle-powernv.c - kernel/msm-4.19 - Gitiles

 /*
  *  cpuidle-powernv - idle state cpuidle driver.
  *  Adapted from drivers/cpuidle/cpuidle-pseries
  *
  */

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/moduleparam.h>
 #include <linux/cpuidle.h>
 #include <linux/cpu.h>
 #include <linux/notifier.h>
 #include <linux/clockchips.h>
 #include <linux/of.h>
 #include <linux/slab.h>

 #include <asm/machdep.h>
 #include <asm/firmware.h>
 #include <asm/opal.h>
 #include <asm/runlatch.h>

 #define POWERNV_THRESHOLD_LATENCY_NS 200000

 struct cpuidle_driver powernv_idle_driver = {
 	.name             = "powernv_idle",
 	.owner            = THIS_MODULE,
 };

 static int max_idle_state;
 static struct cpuidle_state *cpuidle_state_table;

 static u64 stop_psscr_table[CPUIDLE_STATE_MAX];

 static u64 snooze_timeout;
 static bool snooze_timeout_en;

 static int snooze_loop(struct cpuidle_device *dev,
 			struct cpuidle_driver *drv,
 			int index)
 {
 	u64 snooze_exit_time;

 	local_irq_enable();
 	set_thread_flag(TIF_POLLING_NRFLAG);

 	snooze_exit_time = get_tb() + snooze_timeout;
 	ppc64_runlatch_off();
 	while (!need_resched()) {
 		HMT_low();
 		HMT_very_low();
 		if (snooze_timeout_en && get_tb() > snooze_exit_time)
 			break;
 	}

 	HMT_medium();
 	ppc64_runlatch_on();
 	clear_thread_flag(TIF_POLLING_NRFLAG);
 	smp_mb();
 	return index;
 }

 static int nap_loop(struct cpuidle_device *dev,
 			struct cpuidle_driver *drv,
 			int index)
 {
 	ppc64_runlatch_off();
 	power7_idle();
 	ppc64_runlatch_on();
 	return index;
 }

 /* Register for fastsleep only in oneshot mode of broadcast */
 #ifdef CONFIG_TICK_ONESHOT
 static int fastsleep_loop(struct cpuidle_device *dev,
 				struct cpuidle_driver *drv,
 				int index)
 {
 	unsigned long old_lpcr = mfspr(SPRN_LPCR);
 	unsigned long new_lpcr;

 	if (unlikely(system_state < SYSTEM_RUNNING))
 		return index;

 	new_lpcr = old_lpcr;
 	/* Do not exit powersave upon decrementer as we've setup the timer
 	 * offload.
 	 */
 	new_lpcr &= ~LPCR_PECE1;

 	mtspr(SPRN_LPCR, new_lpcr);
 	power7_sleep();

 	mtspr(SPRN_LPCR, old_lpcr);

 	return index;
 }
 #endif

 static int stop_loop(struct cpuidle_device *dev,
 		     struct cpuidle_driver *drv,
 		     int index)
 {
 	ppc64_runlatch_off();
 	power9_idle_stop(stop_psscr_table[index]);
 	ppc64_runlatch_on();
 	return index;
 }

 /*
  * States for dedicated partition case.
  */
 static struct cpuidle_state powernv_states[CPUIDLE_STATE_MAX] = {
 	{ /* Snooze */
 		.name = "snooze",
 		.desc = "snooze",
 		.exit_latency = 0,
 		.target_residency = 0,
 		.enter = snooze_loop },
 };

 static int powernv_cpuidle_add_cpu_notifier(struct notifier_block *n,
 			unsigned long action, void *hcpu)
 {
 	int hotcpu = (unsigned long)hcpu;
 	struct cpuidle_device *dev =
 				per_cpu(cpuidle_devices, hotcpu);

 	if (dev && cpuidle_get_driver()) {
 		switch (action) {
 		case CPU_ONLINE:
 		case CPU_ONLINE_FROZEN:
 			cpuidle_pause_and_lock();
 			cpuidle_enable_device(dev);
 			cpuidle_resume_and_unlock();
 			break;

 		case CPU_DEAD:
 		case CPU_DEAD_FROZEN:
 			cpuidle_pause_and_lock();
 			cpuidle_disable_device(dev);
 			cpuidle_resume_and_unlock();
 			break;

 		default:
 			return NOTIFY_DONE;
 		}
 	}
 	return NOTIFY_OK;
 }

 static struct notifier_block setup_hotplug_notifier = {
 	.notifier_call = powernv_cpuidle_add_cpu_notifier,
 };

 /*
  * powernv_cpuidle_driver_init()
  */
 static int powernv_cpuidle_driver_init(void)
 {
 	int idle_state;
 	struct cpuidle_driver *drv = &powernv_idle_driver;

 	drv->state_count = 0;

 	for (idle_state = 0; idle_state < max_idle_state; ++idle_state) {
 		/* Is the state not enabled? */
 		if (cpuidle_state_table[idle_state].enter == NULL)
 			continue;

 		drv->states[drv->state_count] =	/* structure copy */
 			cpuidle_state_table[idle_state];

 		drv->state_count += 1;
 	}

 	return 0;
 }

 static int powernv_add_idle_states(void)
 {
 	struct device_node *power_mgt;
 	int nr_idle_states = 1; /* Snooze */
 	int dt_idle_states;
 	u32 latency_ns[CPUIDLE_STATE_MAX];
 	u32 residency_ns[CPUIDLE_STATE_MAX];
 	u32 flags[CPUIDLE_STATE_MAX];
 	u64 psscr_val[CPUIDLE_STATE_MAX];
 	const char *names[CPUIDLE_STATE_MAX];
 	int i, rc;

 	/* Currently we have snooze statically defined */

 	power_mgt = of_find_node_by_path("/ibm,opal/power-mgt");
 	if (!power_mgt) {
 		pr_warn("opal: PowerMgmt Node not found\n");
 		goto out;
 	}

 	/* Read values of any property to determine the num of idle states */
 	dt_idle_states = of_property_count_u32_elems(power_mgt, "ibm,cpu-idle-state-flags");
 	if (dt_idle_states < 0) {
 		pr_warn("cpuidle-powernv: no idle states found in the DT\n");
 		goto out;
 	}

 	/*
 	 * Since snooze is used as first idle state, max idle states allowed is
 	 * CPUIDLE_STATE_MAX -1
 	 */
 	if (dt_idle_states > CPUIDLE_STATE_MAX - 1) {
 		pr_warn("cpuidle-powernv: discovered idle states more than allowed");
 		dt_idle_states = CPUIDLE_STATE_MAX - 1;
 	}

 	if (of_property_read_u32_array(power_mgt,
 			"ibm,cpu-idle-state-flags", flags, dt_idle_states)) {
 		pr_warn("cpuidle-powernv : missing ibm,cpu-idle-state-flags in DT\n");
 		goto out;
 	}

 	if (of_property_read_u32_array(power_mgt,
 		"ibm,cpu-idle-state-latencies-ns", latency_ns,
 		dt_idle_states)) {
 		pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-latencies-ns in DT\n");
 		goto out;
 	}
 	if (of_property_read_string_array(power_mgt,
 		"ibm,cpu-idle-state-names", names, dt_idle_states) < 0) {
 		pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-names in DT\n");
 		goto out;
 	}

 	/*
 	 * If the idle states use stop instruction, probe for psscr values
 	 * which are necessary to specify required stop level.
 	 */
 	if (flags[0] & (OPAL_PM_STOP_INST_FAST | OPAL_PM_STOP_INST_DEEP))
 		if (of_property_read_u64_array(power_mgt,
 		    "ibm,cpu-idle-state-psscr", psscr_val, dt_idle_states)) {
 			pr_warn("cpuidle-powernv: missing ibm,cpu-idle-states-psscr in DT\n");
 			goto out;
 		}

 	rc = of_property_read_u32_array(power_mgt,
 		"ibm,cpu-idle-state-residency-ns", residency_ns, dt_idle_states);

 	for (i = 0; i < dt_idle_states; i++) {
 		/*
 		 * If an idle state has exit latency beyond
 		 * POWERNV_THRESHOLD_LATENCY_NS then don't use it
 		 * in cpu-idle.
 		 */
 		if (latency_ns[i] > POWERNV_THRESHOLD_LATENCY_NS)
 			continue;

 		/*
 		 * Cpuidle accepts exit_latency and target_residency in us.
 		 * Use default target_residency values if f/w does not expose it.
 		 */
 		if (flags[i] & OPAL_PM_NAP_ENABLED) {
 			/* Add NAP state */
 			strcpy(powernv_states[nr_idle_states].name, "Nap");
 			strcpy(powernv_states[nr_idle_states].desc, "Nap");
 			powernv_states[nr_idle_states].flags = 0;
 			powernv_states[nr_idle_states].target_residency = 100;
 			powernv_states[nr_idle_states].enter = nap_loop;
 		} else if ((flags[i] & OPAL_PM_STOP_INST_FAST) &&
 				!(flags[i] & OPAL_PM_TIMEBASE_STOP)) {
 			strncpy(powernv_states[nr_idle_states].name,
 				names[i], CPUIDLE_NAME_LEN);
 			strncpy(powernv_states[nr_idle_states].desc,
 				names[i], CPUIDLE_NAME_LEN);
 			powernv_states[nr_idle_states].flags = 0;

 			powernv_states[nr_idle_states].enter = stop_loop;
 			stop_psscr_table[nr_idle_states] = psscr_val[i];
 		}

 		/*
 		 * All cpuidle states with CPUIDLE_FLAG_TIMER_STOP set must come
 		 * within this config dependency check.
 		 */
 #ifdef CONFIG_TICK_ONESHOT
 		if (flags[i] & OPAL_PM_SLEEP_ENABLED ||
 			flags[i] & OPAL_PM_SLEEP_ENABLED_ER1) {
 			/* Add FASTSLEEP state */
 			strcpy(powernv_states[nr_idle_states].name, "FastSleep");
 			strcpy(powernv_states[nr_idle_states].desc, "FastSleep");
 			powernv_states[nr_idle_states].flags = CPUIDLE_FLAG_TIMER_STOP;
 			powernv_states[nr_idle_states].target_residency = 300000;
 			powernv_states[nr_idle_states].enter = fastsleep_loop;
 		} else if ((flags[i] & OPAL_PM_STOP_INST_DEEP) &&
 				(flags[i] & OPAL_PM_TIMEBASE_STOP)) {
 			strncpy(powernv_states[nr_idle_states].name,
 				names[i], CPUIDLE_NAME_LEN);
 			strncpy(powernv_states[nr_idle_states].desc,
 				names[i], CPUIDLE_NAME_LEN);

 			powernv_states[nr_idle_states].flags = CPUIDLE_FLAG_TIMER_STOP;
 			powernv_states[nr_idle_states].enter = stop_loop;
 			stop_psscr_table[nr_idle_states] = psscr_val[i];
 		}
 #endif
 		powernv_states[nr_idle_states].exit_latency =
 				((unsigned int)latency_ns[i]) / 1000;

 		if (!rc) {
 			powernv_states[nr_idle_states].target_residency =
 				((unsigned int)residency_ns[i]) / 1000;
 		}

 		nr_idle_states++;
 	}
 out:
 	return nr_idle_states;
 }

 /*
  * powernv_idle_probe()
  * Choose state table for shared versus dedicated partition
  */
 static int powernv_idle_probe(void)
 {
 	if (cpuidle_disable != IDLE_NO_OVERRIDE)
 		return -ENODEV;

 	if (firmware_has_feature(FW_FEATURE_OPAL)) {
 		cpuidle_state_table = powernv_states;
 		/* Device tree can indicate more idle states */
 		max_idle_state = powernv_add_idle_states();
 		if (max_idle_state > 1) {
 			snooze_timeout_en = true;
 			snooze_timeout = powernv_states[1].target_residency *
 					 tb_ticks_per_usec;
 		}
  	} else
  		return -ENODEV;

 	return 0;
 }

 static int __init powernv_processor_idle_init(void)
 {
 	int retval;

 	retval = powernv_idle_probe();
 	if (retval)
 		return retval;

 	powernv_cpuidle_driver_init();
 	retval = cpuidle_register(&powernv_idle_driver, NULL);
 	if (retval) {
 		printk(KERN_DEBUG "Registration of powernv driver failed.\n");
 		return retval;
 	}

 	register_cpu_notifier(&setup_hotplug_notifier);
 	printk(KERN_DEBUG "powernv_idle_driver registered\n");
 	return 0;
 }

 device_initcall(powernv_processor_idle_init);
	/*
	* cpuidle-powernv - idle state cpuidle driver.
	* Adapted from drivers/cpuidle/cpuidle-pseries
	*
	*/

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/moduleparam.h>
	#include <linux/cpuidle.h>
	#include <linux/cpu.h>
	#include <linux/notifier.h>
	#include <linux/clockchips.h>
	#include <linux/of.h>
	#include <linux/slab.h>

	#include <asm/machdep.h>
	#include <asm/firmware.h>
	#include <asm/opal.h>
	#include <asm/runlatch.h>

	#define POWERNV_THRESHOLD_LATENCY_NS 200000

	struct cpuidle_driver powernv_idle_driver = {
	.name = "powernv_idle",
	.owner = THIS_MODULE,
	};

	static int max_idle_state;
	static struct cpuidle_state *cpuidle_state_table;

	static u64 stop_psscr_table[CPUIDLE_STATE_MAX];

	static u64 snooze_timeout;
	static bool snooze_timeout_en;

	static int snooze_loop(struct cpuidle_device *dev,
	struct cpuidle_driver *drv,
	int index)
	{
	u64 snooze_exit_time;

	local_irq_enable();
	set_thread_flag(TIF_POLLING_NRFLAG);

	snooze_exit_time = get_tb() + snooze_timeout;
	ppc64_runlatch_off();
	while (!need_resched()) {
	HMT_low();
	HMT_very_low();
	if (snooze_timeout_en && get_tb() > snooze_exit_time)
	break;
	}

	HMT_medium();
	ppc64_runlatch_on();
	clear_thread_flag(TIF_POLLING_NRFLAG);
	smp_mb();
	return index;
	}

	static int nap_loop(struct cpuidle_device *dev,
	struct cpuidle_driver *drv,
	int index)
	{
	ppc64_runlatch_off();
	power7_idle();
	ppc64_runlatch_on();
	return index;
	}

	/* Register for fastsleep only in oneshot mode of broadcast */
	#ifdef CONFIG_TICK_ONESHOT
	static int fastsleep_loop(struct cpuidle_device *dev,
	struct cpuidle_driver *drv,
	int index)
	{
	unsigned long old_lpcr = mfspr(SPRN_LPCR);
	unsigned long new_lpcr;

	if (unlikely(system_state < SYSTEM_RUNNING))
	return index;

	new_lpcr = old_lpcr;
	/* Do not exit powersave upon decrementer as we've setup the timer
	* offload.
	*/
	new_lpcr &= ~LPCR_PECE1;

	mtspr(SPRN_LPCR, new_lpcr);
	power7_sleep();

	mtspr(SPRN_LPCR, old_lpcr);

	return index;
	}
	#endif

	static int stop_loop(struct cpuidle_device *dev,
	struct cpuidle_driver *drv,
	int index)
	{
	ppc64_runlatch_off();
	power9_idle_stop(stop_psscr_table[index]);
	ppc64_runlatch_on();
	return index;
	}

	/*
	* States for dedicated partition case.
	*/
	static struct cpuidle_state powernv_states[CPUIDLE_STATE_MAX] = {
	{ /* Snooze */
	.name = "snooze",
	.desc = "snooze",
	.exit_latency = 0,
	.target_residency = 0,
	.enter = snooze_loop },
	};

	static int powernv_cpuidle_add_cpu_notifier(struct notifier_block *n,
	unsigned long action, void *hcpu)
	{
	int hotcpu = (unsigned long)hcpu;
	struct cpuidle_device *dev =
	per_cpu(cpuidle_devices, hotcpu);

	if (dev && cpuidle_get_driver()) {
	switch (action) {
	case CPU_ONLINE:
	case CPU_ONLINE_FROZEN:
	cpuidle_pause_and_lock();
	cpuidle_enable_device(dev);
	cpuidle_resume_and_unlock();
	break;

	case CPU_DEAD:
	case CPU_DEAD_FROZEN:
	cpuidle_pause_and_lock();
	cpuidle_disable_device(dev);
	cpuidle_resume_and_unlock();
	break;

	default:
	return NOTIFY_DONE;
	}
	}
	return NOTIFY_OK;
	}

	static struct notifier_block setup_hotplug_notifier = {
	.notifier_call = powernv_cpuidle_add_cpu_notifier,
	};

	/*
	* powernv_cpuidle_driver_init()
	*/
	static int powernv_cpuidle_driver_init(void)
	{
	int idle_state;
	struct cpuidle_driver *drv = &powernv_idle_driver;

	drv->state_count = 0;

	for (idle_state = 0; idle_state < max_idle_state; ++idle_state) {
	/* Is the state not enabled? */
	if (cpuidle_state_table[idle_state].enter == NULL)
	continue;

	drv->states[drv->state_count] = /* structure copy */
	cpuidle_state_table[idle_state];

	drv->state_count += 1;
	}

	return 0;
	}

	static int powernv_add_idle_states(void)
	{
	struct device_node *power_mgt;
	int nr_idle_states = 1; /* Snooze */
	int dt_idle_states;
	u32 latency_ns[CPUIDLE_STATE_MAX];
	u32 residency_ns[CPUIDLE_STATE_MAX];
	u32 flags[CPUIDLE_STATE_MAX];
	u64 psscr_val[CPUIDLE_STATE_MAX];
	const char *names[CPUIDLE_STATE_MAX];
	int i, rc;

	/* Currently we have snooze statically defined */

	power_mgt = of_find_node_by_path("/ibm,opal/power-mgt");
	if (!power_mgt) {
	pr_warn("opal: PowerMgmt Node not found\n");
	goto out;
	}

	/* Read values of any property to determine the num of idle states */
	dt_idle_states = of_property_count_u32_elems(power_mgt, "ibm,cpu-idle-state-flags");
	if (dt_idle_states < 0) {
	pr_warn("cpuidle-powernv: no idle states found in the DT\n");
	goto out;
	}

	/*
	* Since snooze is used as first idle state, max idle states allowed is
	* CPUIDLE_STATE_MAX -1
	*/
	if (dt_idle_states > CPUIDLE_STATE_MAX - 1) {
	pr_warn("cpuidle-powernv: discovered idle states more than allowed");
	dt_idle_states = CPUIDLE_STATE_MAX - 1;
	}

	if (of_property_read_u32_array(power_mgt,
	"ibm,cpu-idle-state-flags", flags, dt_idle_states)) {
	pr_warn("cpuidle-powernv : missing ibm,cpu-idle-state-flags in DT\n");
	goto out;
	}

	if (of_property_read_u32_array(power_mgt,
	"ibm,cpu-idle-state-latencies-ns", latency_ns,
	dt_idle_states)) {
	pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-latencies-ns in DT\n");
	goto out;
	}
	if (of_property_read_string_array(power_mgt,
	"ibm,cpu-idle-state-names", names, dt_idle_states) < 0) {
	pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-names in DT\n");
	goto out;
	}

	/*
	* If the idle states use stop instruction, probe for psscr values
	* which are necessary to specify required stop level.
	*/
	if (flags[0] & (OPAL_PM_STOP_INST_FAST \| OPAL_PM_STOP_INST_DEEP))
	if (of_property_read_u64_array(power_mgt,
	"ibm,cpu-idle-state-psscr", psscr_val, dt_idle_states)) {
	pr_warn("cpuidle-powernv: missing ibm,cpu-idle-states-psscr in DT\n");
	goto out;
	}

	rc = of_property_read_u32_array(power_mgt,
	"ibm,cpu-idle-state-residency-ns", residency_ns, dt_idle_states);

	for (i = 0; i < dt_idle_states; i++) {
	/*
	* If an idle state has exit latency beyond
	* POWERNV_THRESHOLD_LATENCY_NS then don't use it
	* in cpu-idle.
	*/
	if (latency_ns[i] > POWERNV_THRESHOLD_LATENCY_NS)
	continue;

	/*
	* Cpuidle accepts exit_latency and target_residency in us.
	* Use default target_residency values if f/w does not expose it.
	*/
	if (flags[i] & OPAL_PM_NAP_ENABLED) {
	/* Add NAP state */
	strcpy(powernv_states[nr_idle_states].name, "Nap");
	strcpy(powernv_states[nr_idle_states].desc, "Nap");
	powernv_states[nr_idle_states].flags = 0;
	powernv_states[nr_idle_states].target_residency = 100;
	powernv_states[nr_idle_states].enter = nap_loop;
	} else if ((flags[i] & OPAL_PM_STOP_INST_FAST) &&
	!(flags[i] & OPAL_PM_TIMEBASE_STOP)) {
	strncpy(powernv_states[nr_idle_states].name,
	names[i], CPUIDLE_NAME_LEN);
	strncpy(powernv_states[nr_idle_states].desc,
	names[i], CPUIDLE_NAME_LEN);
	powernv_states[nr_idle_states].flags = 0;

	powernv_states[nr_idle_states].enter = stop_loop;
	stop_psscr_table[nr_idle_states] = psscr_val[i];
	}

	/*
	* All cpuidle states with CPUIDLE_FLAG_TIMER_STOP set must come
	* within this config dependency check.
	*/
	#ifdef CONFIG_TICK_ONESHOT
	if (flags[i] & OPAL_PM_SLEEP_ENABLED \|\|
	flags[i] & OPAL_PM_SLEEP_ENABLED_ER1) {
	/* Add FASTSLEEP state */
	strcpy(powernv_states[nr_idle_states].name, "FastSleep");
	strcpy(powernv_states[nr_idle_states].desc, "FastSleep");
	powernv_states[nr_idle_states].flags = CPUIDLE_FLAG_TIMER_STOP;
	powernv_states[nr_idle_states].target_residency = 300000;
	powernv_states[nr_idle_states].enter = fastsleep_loop;
	} else if ((flags[i] & OPAL_PM_STOP_INST_DEEP) &&
	(flags[i] & OPAL_PM_TIMEBASE_STOP)) {
	strncpy(powernv_states[nr_idle_states].name,
	names[i], CPUIDLE_NAME_LEN);
	strncpy(powernv_states[nr_idle_states].desc,
	names[i], CPUIDLE_NAME_LEN);

	powernv_states[nr_idle_states].flags = CPUIDLE_FLAG_TIMER_STOP;
	powernv_states[nr_idle_states].enter = stop_loop;
	stop_psscr_table[nr_idle_states] = psscr_val[i];
	}
	#endif
	powernv_states[nr_idle_states].exit_latency =
	((unsigned int)latency_ns[i]) / 1000;

	if (!rc) {
	powernv_states[nr_idle_states].target_residency =
	((unsigned int)residency_ns[i]) / 1000;
	}

	nr_idle_states++;
	}
	out:
	return nr_idle_states;
	}

	/*
	* powernv_idle_probe()
	* Choose state table for shared versus dedicated partition
	*/
	static int powernv_idle_probe(void)
	{
	if (cpuidle_disable != IDLE_NO_OVERRIDE)
	return -ENODEV;

	if (firmware_has_feature(FW_FEATURE_OPAL)) {
	cpuidle_state_table = powernv_states;
	/* Device tree can indicate more idle states */
	max_idle_state = powernv_add_idle_states();
	if (max_idle_state > 1) {
	snooze_timeout_en = true;
	snooze_timeout = powernv_states[1].target_residency *
	tb_ticks_per_usec;
	}
	} else
	return -ENODEV;

	return 0;
	}

	static int __init powernv_processor_idle_init(void)
	{
	int retval;

	retval = powernv_idle_probe();
	if (retval)
	return retval;

	powernv_cpuidle_driver_init();
	retval = cpuidle_register(&powernv_idle_driver, NULL);
	if (retval) {
	printk(KERN_DEBUG "Registration of powernv driver failed.\n");
	return retval;
	}

	register_cpu_notifier(&setup_hotplug_notifier);
	printk(KERN_DEBUG "powernv_idle_driver registered\n");
	return 0;
	}

	device_initcall(powernv_processor_idle_init);