[linux-block.git] / drivers / cpuidle / cpuidle-psci.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * PSCI CPU idle driver.
 *
 * Copyright (C) 2019 ARM Ltd.
 * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
 */

#define pr_fmt(fmt) "CPUidle PSCI: " fmt

#include <linux/cpuhotplug.h>
#include <linux/cpu_cooling.h>
#include <linux/cpuidle.h>
#include <linux/cpumask.h>
#include <linux/cpu_pm.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/device/faux.h>
#include <linux/psci.h>
#include <linux/pm_domain.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/syscore_ops.h>

#include <asm/cpuidle.h>
#include <trace/events/power.h>

#include "cpuidle-psci.h"
#include "dt_idle_states.h"
#include "dt_idle_genpd.h"

struct psci_cpuidle_data {
	u32 *psci_states;
	struct device *dev;
};

struct psci_cpuidle_domain_state {
	struct generic_pm_domain *pd;
	unsigned int state_idx;
	u32 state;
};

static DEFINE_PER_CPU_READ_MOSTLY(struct psci_cpuidle_data, psci_cpuidle_data);
static DEFINE_PER_CPU(struct psci_cpuidle_domain_state, psci_domain_state);
static bool psci_cpuidle_use_syscore;
static bool psci_cpuidle_use_cpuhp;

void psci_set_domain_state(struct generic_pm_domain *pd, unsigned int state_idx,
			   u32 state)
{
	struct psci_cpuidle_domain_state *ds = this_cpu_ptr(&psci_domain_state);

	ds->pd = pd;
	ds->state_idx = state_idx;
	ds->state = state;
}

static inline void psci_clear_domain_state(void)
{
	__this_cpu_write(psci_domain_state.state, 0);
}

static __cpuidle int __psci_enter_domain_idle_state(struct cpuidle_device *dev,
						    struct cpuidle_driver *drv, int idx,
						    bool s2idle)
{
	struct psci_cpuidle_data *data = this_cpu_ptr(&psci_cpuidle_data);
	u32 *states = data->psci_states;
	struct device *pd_dev = data->dev;
	struct psci_cpuidle_domain_state *ds;
	u32 state = states[idx];
	int ret;

	ret = cpu_pm_enter();
	if (ret)
		return -1;

	/* Do runtime PM to manage a hierarchical CPU toplogy. */
	if (s2idle)
		dev_pm_genpd_suspend(pd_dev);
	else
		pm_runtime_put_sync_suspend(pd_dev);

	ds = this_cpu_ptr(&psci_domain_state);
	if (ds->state)
		state = ds->state;

	trace_psci_domain_idle_enter(dev->cpu, state, s2idle);
	ret = psci_cpu_suspend_enter(state) ? -1 : idx;
	trace_psci_domain_idle_exit(dev->cpu, state, s2idle);

	if (s2idle)
		dev_pm_genpd_resume(pd_dev);
	else
		pm_runtime_get_sync(pd_dev);

	cpu_pm_exit();

	/* Correct domain-idlestate statistics if we failed to enter. */
	if (ret == -1 && ds->state)
		pm_genpd_inc_rejected(ds->pd, ds->state_idx);

	/* Clear the domain state to start fresh when back from idle. */
	psci_clear_domain_state();
	return ret;
}

static int psci_enter_domain_idle_state(struct cpuidle_device *dev,
					struct cpuidle_driver *drv, int idx)
{
	return __psci_enter_domain_idle_state(dev, drv, idx, false);
}

static int psci_enter_s2idle_domain_idle_state(struct cpuidle_device *dev,
					       struct cpuidle_driver *drv,
					       int idx)
{
	return __psci_enter_domain_idle_state(dev, drv, idx, true);
}

static int psci_idle_cpuhp_up(unsigned int cpu)
{
	struct device *pd_dev = __this_cpu_read(psci_cpuidle_data.dev);

	if (pd_dev)
		pm_runtime_get_sync(pd_dev);

	return 0;
}

static int psci_idle_cpuhp_down(unsigned int cpu)
{
	struct device *pd_dev = __this_cpu_read(psci_cpuidle_data.dev);

	if (pd_dev) {
		pm_runtime_put_sync(pd_dev);
		/* Clear domain state to start fresh at next online. */
		psci_clear_domain_state();
	}

	return 0;
}

static void psci_idle_syscore_switch(bool suspend)
{
	bool cleared = false;
	struct device *dev;
	int cpu;

	for_each_possible_cpu(cpu) {
		dev = per_cpu_ptr(&psci_cpuidle_data, cpu)->dev;

		if (dev && suspend) {
			dev_pm_genpd_suspend(dev);
		} else if (dev) {
			dev_pm_genpd_resume(dev);

			/* Account for userspace having offlined a CPU. */
			if (pm_runtime_status_suspended(dev))
				pm_runtime_set_active(dev);

			/* Clear domain state to re-start fresh. */
			if (!cleared) {
				psci_clear_domain_state();
				cleared = true;
			}
		}
	}
}

static int psci_idle_syscore_suspend(void)
{
	psci_idle_syscore_switch(true);
	return 0;
}

static void psci_idle_syscore_resume(void)
{
	psci_idle_syscore_switch(false);
}

static struct syscore_ops psci_idle_syscore_ops = {
	.suspend = psci_idle_syscore_suspend,
	.resume = psci_idle_syscore_resume,
};

static void psci_idle_init_syscore(void)
{
	if (psci_cpuidle_use_syscore)
		register_syscore_ops(&psci_idle_syscore_ops);
}

static void psci_idle_init_cpuhp(void)
{
	int err;

	if (!psci_cpuidle_use_cpuhp)
		return;

	err = cpuhp_setup_state_nocalls(CPUHP_AP_CPU_PM_STARTING,
					"cpuidle/psci:online",
					psci_idle_cpuhp_up,
					psci_idle_cpuhp_down);
	if (err)
		pr_warn("Failed %d while setup cpuhp state\n", err);
}

static __cpuidle int psci_enter_idle_state(struct cpuidle_device *dev,
					   struct cpuidle_driver *drv, int idx)
{
	u32 *state = __this_cpu_read(psci_cpuidle_data.psci_states);

	return CPU_PM_CPU_IDLE_ENTER_PARAM_RCU(psci_cpu_suspend_enter, idx, state[idx]);
}

static const struct of_device_id psci_idle_state_match[] = {
	{ .compatible = "arm,idle-state",
	  .data = psci_enter_idle_state },
	{ },
};

int psci_dt_parse_state_node(struct device_node *np, u32 *state)
{
	int err = of_property_read_u32(np, "arm,psci-suspend-param", state);

	if (err) {
		pr_warn("%pOF missing arm,psci-suspend-param property\n", np);
		return err;
	}

	if (!psci_power_state_is_valid(*state)) {
		pr_warn("Invalid PSCI power state %#x\n", *state);
		return -EINVAL;
	}

	return 0;
}

static int psci_dt_cpu_init_topology(struct cpuidle_driver *drv,
				     struct psci_cpuidle_data *data,
				     unsigned int state_count, int cpu)
{
	/* Currently limit the hierarchical topology to be used in OSI mode. */
	if (!psci_has_osi_support())
		return 0;

	data->dev = dt_idle_attach_cpu(cpu, "psci");
	if (IS_ERR_OR_NULL(data->dev))
		return PTR_ERR_OR_ZERO(data->dev);

	psci_cpuidle_use_syscore = true;

	/*
	 * Using the deepest state for the CPU to trigger a potential selection
	 * of a shared state for the domain, assumes the domain states are all
	 * deeper states. On PREEMPT_RT the hierarchical topology is limited to
	 * s2ram and s2idle.
	 */
	drv->states[state_count - 1].enter_s2idle = psci_enter_s2idle_domain_idle_state;
	if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
		drv->states[state_count - 1].enter = psci_enter_domain_idle_state;
		psci_cpuidle_use_cpuhp = true;
	}

	return 0;
}

static int psci_dt_cpu_init_idle(struct device *dev, struct cpuidle_driver *drv,
				 struct device_node *cpu_node,
				 unsigned int state_count, int cpu)
{
	int i, ret = 0;
	u32 *psci_states;
	struct device_node *state_node;
	struct psci_cpuidle_data *data = per_cpu_ptr(&psci_cpuidle_data, cpu);

	state_count++; /* Add WFI state too */
	psci_states = devm_kcalloc(dev, state_count, sizeof(*psci_states),
				   GFP_KERNEL);
	if (!psci_states)
		return -ENOMEM;

	for (i = 1; i < state_count; i++) {
		state_node = of_get_cpu_state_node(cpu_node, i - 1);
		if (!state_node)
			break;

		ret = psci_dt_parse_state_node(state_node, &psci_states[i]);
		of_node_put(state_node);

		if (ret)
			return ret;

		pr_debug("psci-power-state %#x index %d\n", psci_states[i], i);
	}

	if (i != state_count)
		return -ENODEV;

	/* Initialize optional data, used for the hierarchical topology. */
	ret = psci_dt_cpu_init_topology(drv, data, state_count, cpu);
	if (ret < 0)
		return ret;

	/* Idle states parsed correctly, store them in the per-cpu struct. */
	data->psci_states = psci_states;
	return 0;
}

static int psci_cpu_init_idle(struct device *dev, struct cpuidle_driver *drv,
			      unsigned int cpu, unsigned int state_count)
{
	struct device_node *cpu_node;
	int ret;

	/*
	 * If the PSCI cpu_suspend function hook has not been initialized
	 * idle states must not be enabled, so bail out
	 */
	if (!psci_ops.cpu_suspend)
		return -EOPNOTSUPP;

	cpu_node = of_cpu_device_node_get(cpu);
	if (!cpu_node)
		return -ENODEV;

	ret = psci_dt_cpu_init_idle(dev, drv, cpu_node, state_count, cpu);

	of_node_put(cpu_node);

	return ret;
}

static void psci_cpu_deinit_idle(int cpu)
{
	struct psci_cpuidle_data *data = per_cpu_ptr(&psci_cpuidle_data, cpu);

	dt_idle_detach_cpu(data->dev);
	psci_cpuidle_use_syscore = false;
	psci_cpuidle_use_cpuhp = false;
}

static int psci_idle_init_cpu(struct device *dev, int cpu)
{
	struct cpuidle_driver *drv;
	struct device_node *cpu_node;
	const char *enable_method;
	int ret = 0;

	cpu_node = of_cpu_device_node_get(cpu);
	if (!cpu_node)
		return -ENODEV;

	/*
	 * Check whether the enable-method for the cpu is PSCI, fail
	 * if it is not.
	 */
	enable_method = of_get_property(cpu_node, "enable-method", NULL);
	if (!enable_method || (strcmp(enable_method, "psci")))
		ret = -ENODEV;

	of_node_put(cpu_node);
	if (ret)
		return ret;

	drv = devm_kzalloc(dev, sizeof(*drv), GFP_KERNEL);
	if (!drv)
		return -ENOMEM;

	drv->name = "psci_idle";
	drv->owner = THIS_MODULE;
	drv->cpumask = (struct cpumask *)cpumask_of(cpu);

	/*
	 * PSCI idle states relies on architectural WFI to be represented as
	 * state index 0.
	 */
	drv->states[0].enter = psci_enter_idle_state;
	drv->states[0].exit_latency = 1;
	drv->states[0].target_residency = 1;
	drv->states[0].power_usage = UINT_MAX;
	strcpy(drv->states[0].name, "WFI");
	strcpy(drv->states[0].desc, "ARM WFI");

	/*
	 * If no DT idle states are detected (ret == 0) let the driver
	 * initialization fail accordingly since there is no reason to
	 * initialize the idle driver if only wfi is supported, the
	 * default archictectural back-end already executes wfi
	 * on idle entry.
	 */
	ret = dt_init_idle_driver(drv, psci_idle_state_match, 1);
	if (ret <= 0)
		return ret ? : -ENODEV;

	/*
	 * Initialize PSCI idle states.
	 */
	ret = psci_cpu_init_idle(dev, drv, cpu, ret);
	if (ret) {
		pr_err("CPU %d failed to PSCI idle\n", cpu);
		return ret;
	}

	ret = cpuidle_register(drv, NULL);
	if (ret)
		goto deinit;

	cpuidle_cooling_register(drv);

	return 0;
deinit:
	psci_cpu_deinit_idle(cpu);
	return ret;
}

/*
 * psci_idle_probe - Initializes PSCI cpuidle driver
 *
 * Initializes PSCI cpuidle driver for all present CPUs, if any CPU fails
 * to register cpuidle driver then rollback to cancel all CPUs
 * registration.
 */
static int psci_cpuidle_probe(struct faux_device *fdev)
{
	int cpu, ret;
	struct cpuidle_driver *drv;
	struct cpuidle_device *dev;

	for_each_present_cpu(cpu) {
		ret = psci_idle_init_cpu(&fdev->dev, cpu);
		if (ret)
			goto out_fail;
	}

	psci_idle_init_syscore();
	psci_idle_init_cpuhp();
	return 0;

out_fail:
	while (--cpu >= 0) {
		dev = per_cpu(cpuidle_devices, cpu);
		drv = cpuidle_get_cpu_driver(dev);
		cpuidle_unregister(drv);
		psci_cpu_deinit_idle(cpu);
	}

	return ret;
}

static struct faux_device_ops psci_cpuidle_ops = {
	.probe = psci_cpuidle_probe,
};

static bool __init dt_idle_state_present(void)
{
	struct device_node *cpu_node __free(device_node) =
			of_cpu_device_node_get(cpumask_first(cpu_possible_mask));
	if (!cpu_node)
		return false;

	struct device_node *state_node __free(device_node) =
			of_get_cpu_state_node(cpu_node, 0);
	if (!state_node)
		return false;

	return !!of_match_node(psci_idle_state_match, state_node);
}

static int __init psci_idle_init(void)
{
	struct faux_device *fdev;

	if (!dt_idle_state_present())
		return 0;

	fdev = faux_device_create("psci-cpuidle", NULL, &psci_cpuidle_ops);
	if (!fdev) {
		pr_err("Failed to create psci-cpuidle device\n");
		return -ENODEV;
	}

	return 0;
}
device_initcall(psci_idle_init);
Commit	Line	Data
81d549e0 LP	1	// SPDX-License-Identifier: GPL-2.0-only
	2	/*
	3	* PSCI CPU idle driver.
	4	*
	5	* Copyright (C) 2019 ARM Ltd.
	6	* Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
	7	*/
	8
	9	#define pr_fmt(fmt) "CPUidle PSCI: " fmt
	10
9c6ceecb	11	#include <linux/cpuhotplug.h>
fc7a3d9e	12	#include <linux/cpu_cooling.h>
81d549e0 LP	13	#include <linux/cpuidle.h>
	14	#include <linux/cpumask.h>
	15	#include <linux/cpu_pm.h>
	16	#include <linux/kernel.h>
	17	#include <linux/module.h>
	18	#include <linux/of.h>
af5376a7	19	#include <linux/device/faux.h>
81d549e0	20	#include <linux/psci.h>
670c90de	21	#include <linux/pm_domain.h>
ce85aef5	22	#include <linux/pm_runtime.h>
81d549e0	23	#include <linux/slab.h>
166bf835	24	#include <linux/string.h>
171b66e2	25	#include <linux/syscore_ops.h>
81d549e0 LP	26
81d549e0 LP	27	#include <asm/cpuidle.h>
7b764483	28	#include <trace/events/power.h>
81d549e0	29
8554951a	30	#include "cpuidle-psci.h"
81d549e0	31	#include "dt_idle_states.h"
d72d7d6c	32	#include "dt_idle_genpd.h"
81d549e0	33
8554951a UH	34	struct psci_cpuidle_data {
	35	u32 *psci_states;
	36	struct device *dev;
	37	};
	38
3290e9f9	39	struct psci_cpuidle_domain_state {
d0252ba8 UH	40	struct generic_pm_domain *pd;
d0252ba8 UH	41	unsigned int state_idx;
3290e9f9 UH	42	u32 state;
	43	};
	44
8554951a	45	static DEFINE_PER_CPU_READ_MOSTLY(struct psci_cpuidle_data, psci_cpuidle_data);
3290e9f9	46	static DEFINE_PER_CPU(struct psci_cpuidle_domain_state, psci_domain_state);
4517b1c3	47	static bool psci_cpuidle_use_syscore;
166bf835	48	static bool psci_cpuidle_use_cpuhp;
a0cf3194	49
d0252ba8 UH	50	void psci_set_domain_state(struct generic_pm_domain *pd, unsigned int state_idx,
d0252ba8 UH	51	u32 state)
a0cf3194	52	{
d0252ba8	53	struct psci_cpuidle_domain_state *ds = this_cpu_ptr(&psci_domain_state);
a0cf3194	54
d0252ba8 UH	55	ds->pd = pd;
	56	ds->state_idx = state_idx;
	57	ds->state = state;
3290e9f9 UH	58	}
	59
	60	static inline void psci_clear_domain_state(void)
	61	{
	62	__this_cpu_write(psci_domain_state.state, 0);
a0cf3194 UH	63	}
a0cf3194 UH	64
69e26b4f PZ	65	static __cpuidle int __psci_enter_domain_idle_state(struct cpuidle_device *dev,
	66	struct cpuidle_driver *drv, int idx,
	67	bool s2idle)
a0cf3194 UH	68	{
	69	struct psci_cpuidle_data *data = this_cpu_ptr(&psci_cpuidle_data);
	70	u32 *states = data->psci_states;
ce85aef5	71	struct device *pd_dev = data->dev;
d0252ba8 UH	72	struct psci_cpuidle_domain_state *ds;
d0252ba8 UH	73	u32 state = states[idx];
a0cf3194 UH	74	int ret;
a0cf3194 UH	75
8b7ce5e4 UH	76	ret = cpu_pm_enter();
	77	if (ret)
	78	return -1;
	79
ce85aef5	80	/* Do runtime PM to manage a hierarchical CPU toplogy. */
670c90de UH	81	if (s2idle)
	82	dev_pm_genpd_suspend(pd_dev);
	83	else
	84	pm_runtime_put_sync_suspend(pd_dev);
e038f7b8	85
d0252ba8 UH	86	ds = this_cpu_ptr(&psci_domain_state);
	87	if (ds->state)
	88	state = ds->state;
a0cf3194	89
7b764483	90	trace_psci_domain_idle_enter(dev->cpu, state, s2idle);
8b7ce5e4	91	ret = psci_cpu_suspend_enter(state) ? -1 : idx;
7b764483	92	trace_psci_domain_idle_exit(dev->cpu, state, s2idle);
a0cf3194	93
670c90de UH	94	if (s2idle)
	95	dev_pm_genpd_resume(pd_dev);
	96	else
	97	pm_runtime_get_sync(pd_dev);
ce85aef5	98
8b7ce5e4 UH	99	cpu_pm_exit();
8b7ce5e4 UH	100
d0252ba8 UH	101	/* Correct domain-idlestate statistics if we failed to enter. */
	102	if (ret == -1 && ds->state)
	103	pm_genpd_inc_rejected(ds->pd, ds->state_idx);
	104
a0cf3194	105	/* Clear the domain state to start fresh when back from idle. */
3290e9f9	106	psci_clear_domain_state();
a0cf3194 UH	107	return ret;
a0cf3194 UH	108	}
9ffeb6d0	109
670c90de UH	110	static int psci_enter_domain_idle_state(struct cpuidle_device *dev,
	111	struct cpuidle_driver *drv, int idx)
	112	{
	113	return __psci_enter_domain_idle_state(dev, drv, idx, false);
	114	}
	115
	116	static int psci_enter_s2idle_domain_idle_state(struct cpuidle_device *dev,
	117	struct cpuidle_driver *drv,
	118	int idx)
	119	{
	120	return __psci_enter_domain_idle_state(dev, drv, idx, true);
	121	}
	122
9c6ceecb UH	123	static int psci_idle_cpuhp_up(unsigned int cpu)
	124	{
	125	struct device *pd_dev = __this_cpu_read(psci_cpuidle_data.dev);
	126
	127	if (pd_dev)
	128	pm_runtime_get_sync(pd_dev);
	129
	130	return 0;
	131	}
	132
	133	static int psci_idle_cpuhp_down(unsigned int cpu)
	134	{
	135	struct device *pd_dev = __this_cpu_read(psci_cpuidle_data.dev);
	136
	137	if (pd_dev) {
	138	pm_runtime_put_sync(pd_dev);
	139	/* Clear domain state to start fresh at next online. */
3290e9f9	140	psci_clear_domain_state();
9c6ceecb UH	141	}
	142
	143	return 0;
	144	}
	145
171b66e2 UH	146	static void psci_idle_syscore_switch(bool suspend)
	147	{
	148	bool cleared = false;
	149	struct device *dev;
	150	int cpu;
	151
	152	for_each_possible_cpu(cpu) {
	153	dev = per_cpu_ptr(&psci_cpuidle_data, cpu)->dev;
	154
	155	if (dev && suspend) {
	156	dev_pm_genpd_suspend(dev);
	157	} else if (dev) {
	158	dev_pm_genpd_resume(dev);
	159
	160	/* Account for userspace having offlined a CPU. */
	161	if (pm_runtime_status_suspended(dev))
	162	pm_runtime_set_active(dev);
	163
	164	/* Clear domain state to re-start fresh. */
	165	if (!cleared) {
3290e9f9	166	psci_clear_domain_state();
171b66e2 UH	167	cleared = true;
	168	}
	169	}
	170	}
	171	}
	172
	173	static int psci_idle_syscore_suspend(void)
	174	{
	175	psci_idle_syscore_switch(true);
	176	return 0;
	177	}
	178
	179	static void psci_idle_syscore_resume(void)
	180	{
	181	psci_idle_syscore_switch(false);
	182	}
	183
	184	static struct syscore_ops psci_idle_syscore_ops = {
	185	.suspend = psci_idle_syscore_suspend,
	186	.resume = psci_idle_syscore_resume,
	187	};
	188
4517b1c3 UH	189	static void psci_idle_init_syscore(void)
	190	{
	191	if (psci_cpuidle_use_syscore)
	192	register_syscore_ops(&psci_idle_syscore_ops);
	193	}
	194
166bf835	195	static void psci_idle_init_cpuhp(void)
9c6ceecb UH	196	{
	197	int err;
	198
	199	if (!psci_cpuidle_use_cpuhp)
	200	return;
	201
	202	err = cpuhp_setup_state_nocalls(CPUHP_AP_CPU_PM_STARTING,
	203	"cpuidle/psci:online",
	204	psci_idle_cpuhp_up,
	205	psci_idle_cpuhp_down);
	206	if (err)
	207	pr_warn("Failed %d while setup cpuhp state\n", err);
	208	}
	209
69e26b4f PZ	210	static __cpuidle int psci_enter_idle_state(struct cpuidle_device *dev,
69e26b4f PZ	211	struct cpuidle_driver *drv, int idx)
81d549e0	212	{
8554951a	213	u32 *state = __this_cpu_read(psci_cpuidle_data.psci_states);
9ffeb6d0	214
19235e47	215	return CPU_PM_CPU_IDLE_ENTER_PARAM_RCU(psci_cpu_suspend_enter, idx, state[idx]);
81d549e0 LP	216	}
81d549e0 LP	217
166bf835	218	static const struct of_device_id psci_idle_state_match[] = {
81d549e0 LP	219	{ .compatible = "arm,idle-state",
	220	.data = psci_enter_idle_state },
	221	{ },
	222	};
	223
166bf835	224	int psci_dt_parse_state_node(struct device_node np, u32 state)
9ffeb6d0 LP	225	{
	226	int err = of_property_read_u32(np, "arm,psci-suspend-param", state);
	227
	228	if (err) {
	229	pr_warn("%pOF missing arm,psci-suspend-param property\n", np);
	230	return err;
	231	}
	232
	233	if (!psci_power_state_is_valid(*state)) {
	234	pr_warn("Invalid PSCI power state %#x\n", *state);
	235	return -EINVAL;
	236	}
	237
	238	return 0;
	239	}
	240
166bf835 UH	241	static int psci_dt_cpu_init_topology(struct cpuidle_driver *drv,
	242	struct psci_cpuidle_data *data,
	243	unsigned int state_count, int cpu)
7fbee48e UH	244	{
	245	/* Currently limit the hierarchical topology to be used in OSI mode. */
	246	if (!psci_has_osi_support())
	247	return 0;
	248
d72d7d6c	249	data->dev = dt_idle_attach_cpu(cpu, "psci");
7fbee48e UH	250	if (IS_ERR_OR_NULL(data->dev))
	251	return PTR_ERR_OR_ZERO(data->dev);
	252
4517b1c3 UH	253	psci_cpuidle_use_syscore = true;
4517b1c3 UH	254
7fbee48e UH	255	/*
	256	* Using the deepest state for the CPU to trigger a potential selection
	257	* of a shared state for the domain, assumes the domain states are all
1c4b2932 UH	258	* deeper states. On PREEMPT_RT the hierarchical topology is limited to
1c4b2932 UH	259	* s2ram and s2idle.
7fbee48e	260	*/
670c90de	261	drv->states[state_count - 1].enter_s2idle = psci_enter_s2idle_domain_idle_state;
1c4b2932 UH	262	if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
	263	drv->states[state_count - 1].enter = psci_enter_domain_idle_state;
	264	psci_cpuidle_use_cpuhp = true;
	265	}
7fbee48e UH	266
	267	return 0;
	268	}
	269
166bf835 UH	270	static int psci_dt_cpu_init_idle(struct device dev, struct cpuidle_driver drv,
	271	struct device_node *cpu_node,
	272	unsigned int state_count, int cpu)
9ffeb6d0	273	{
1595e4b0	274	int i, ret = 0;
9ffeb6d0 LP	275	u32 *psci_states;
9ffeb6d0 LP	276	struct device_node *state_node;
8554951a	277	struct psci_cpuidle_data *data = per_cpu_ptr(&psci_cpuidle_data, cpu);
9ffeb6d0	278
1595e4b0	279	state_count++; /* Add WFI state too */
166bf835 UH	280	psci_states = devm_kcalloc(dev, state_count, sizeof(*psci_states),
166bf835 UH	281	GFP_KERNEL);
9ffeb6d0 LP	282	if (!psci_states)
	283	return -ENOMEM;
	284
1595e4b0	285	for (i = 1; i < state_count; i++) {
f08cfbfa	286	state_node = of_get_cpu_state_node(cpu_node, i - 1);
1595e4b0 UH	287	if (!state_node)
	288	break;
	289
9ffeb6d0 LP	290	ret = psci_dt_parse_state_node(state_node, &psci_states[i]);
	291	of_node_put(state_node);
	292
	293	if (ret)
166bf835	294	return ret;
9ffeb6d0 LP	295
	296	pr_debug("psci-power-state %#x index %d\n", psci_states[i], i);
	297	}
	298
166bf835 UH	299	if (i != state_count)
166bf835 UH	300	return -ENODEV;
1595e4b0	301
7fbee48e UH	302	/* Initialize optional data, used for the hierarchical topology. */
	303	ret = psci_dt_cpu_init_topology(drv, data, state_count, cpu);
	304	if (ret < 0)
166bf835	305	return ret;
8554951a UH	306
	307	/* Idle states parsed correctly, store them in the per-cpu struct. */
	308	data->psci_states = psci_states;
9ffeb6d0	309	return 0;
9ffeb6d0 LP	310	}
9ffeb6d0 LP	311
166bf835 UH	312	static int psci_cpu_init_idle(struct device dev, struct cpuidle_driver drv,
166bf835 UH	313	unsigned int cpu, unsigned int state_count)
9ffeb6d0 LP	314	{
	315	struct device_node *cpu_node;
	316	int ret;
	317
	318	/*
	319	* If the PSCI cpu_suspend function hook has not been initialized
	320	* idle states must not be enabled, so bail out
	321	*/
	322	if (!psci_ops.cpu_suspend)
	323	return -EOPNOTSUPP;
	324
	325	cpu_node = of_cpu_device_node_get(cpu);
	326	if (!cpu_node)
	327	return -ENODEV;
	328
166bf835	329	ret = psci_dt_cpu_init_idle(dev, drv, cpu_node, state_count, cpu);
9ffeb6d0 LP	330
	331	of_node_put(cpu_node);
	332
	333	return ret;
	334	}
	335
166bf835 UH	336	static void psci_cpu_deinit_idle(int cpu)
	337	{
	338	struct psci_cpuidle_data *data = per_cpu_ptr(&psci_cpuidle_data, cpu);
	339
d72d7d6c	340	dt_idle_detach_cpu(data->dev);
4517b1c3	341	psci_cpuidle_use_syscore = false;
166bf835 UH	342	psci_cpuidle_use_cpuhp = false;
	343	}
	344
	345	static int psci_idle_init_cpu(struct device *dev, int cpu)
81d549e0 LP	346	{
	347	struct cpuidle_driver *drv;
	348	struct device_node *cpu_node;
	349	const char *enable_method;
	350	int ret = 0;
	351
	352	cpu_node = of_cpu_device_node_get(cpu);
	353	if (!cpu_node)
	354	return -ENODEV;
	355
	356	/*
	357	* Check whether the enable-method for the cpu is PSCI, fail
	358	* if it is not.
	359	*/
	360	enable_method = of_get_property(cpu_node, "enable-method", NULL);
	361	if (!enable_method \|\| (strcmp(enable_method, "psci")))
	362	ret = -ENODEV;
	363
	364	of_node_put(cpu_node);
	365	if (ret)
	366	return ret;
	367
166bf835	368	drv = devm_kzalloc(dev, sizeof(*drv), GFP_KERNEL);
81d549e0 LP	369	if (!drv)
	370	return -ENOMEM;
	371
166bf835 UH	372	drv->name = "psci_idle";
166bf835 UH	373	drv->owner = THIS_MODULE;
81d549e0 LP	374	drv->cpumask = (struct cpumask *)cpumask_of(cpu);
	375
	376	/*
166bf835 UH	377	* PSCI idle states relies on architectural WFI to be represented as
	378	* state index 0.
	379	*/
	380	drv->states[0].enter = psci_enter_idle_state;
	381	drv->states[0].exit_latency = 1;
	382	drv->states[0].target_residency = 1;
	383	drv->states[0].power_usage = UINT_MAX;
	384	strcpy(drv->states[0].name, "WFI");
	385	strcpy(drv->states[0].desc, "ARM WFI");
	386
	387	/*
81d549e0 LP	388	* If no DT idle states are detected (ret == 0) let the driver
	389	* initialization fail accordingly since there is no reason to
	390	* initialize the idle driver if only wfi is supported, the
	391	* default archictectural back-end already executes wfi
	392	* on idle entry.
	393	*/
	394	ret = dt_init_idle_driver(drv, psci_idle_state_match, 1);
166bf835 UH	395	if (ret <= 0)
166bf835 UH	396	return ret ? : -ENODEV;
81d549e0 LP	397
	398	/*
	399	* Initialize PSCI idle states.
	400	*/
166bf835	401	ret = psci_cpu_init_idle(dev, drv, cpu, ret);
81d549e0 LP	402	if (ret) {
81d549e0 LP	403	pr_err("CPU %d failed to PSCI idle\n", cpu);
166bf835	404	return ret;
81d549e0 LP	405	}
	406
	407	ret = cpuidle_register(drv, NULL);
	408	if (ret)
166bf835	409	goto deinit;
81d549e0	410
fc7a3d9e DL	411	cpuidle_cooling_register(drv);
fc7a3d9e DL	412
81d549e0	413	return 0;
166bf835 UH	414	deinit:
166bf835 UH	415	psci_cpu_deinit_idle(cpu);
81d549e0 LP	416	return ret;
	417	}
	418
	419	/*
166bf835	420	* psci_idle_probe - Initializes PSCI cpuidle driver
81d549e0	421	*
68cb0139	422	* Initializes PSCI cpuidle driver for all present CPUs, if any CPU fails
81d549e0 LP	423	* to register cpuidle driver then rollback to cancel all CPUs
	424	* registration.
	425	*/
af5376a7	426	static int psci_cpuidle_probe(struct faux_device *fdev)
81d549e0 LP	427	{
	428	int cpu, ret;
	429	struct cpuidle_driver *drv;
	430	struct cpuidle_device *dev;
	431
68cb0139	432	for_each_present_cpu(cpu) {
af5376a7	433	ret = psci_idle_init_cpu(&fdev->dev, cpu);
81d549e0 LP	434	if (ret)
	435	goto out_fail;
	436	}
	437
4517b1c3	438	psci_idle_init_syscore();
9c6ceecb	439	psci_idle_init_cpuhp();
81d549e0 LP	440	return 0;
	441
	442	out_fail:
	443	while (--cpu >= 0) {
	444	dev = per_cpu(cpuidle_devices, cpu);
	445	drv = cpuidle_get_cpu_driver(dev);
	446	cpuidle_unregister(drv);
166bf835	447	psci_cpu_deinit_idle(cpu);
81d549e0 LP	448	}
	449
	450	return ret;
	451	}
166bf835	452
af5376a7	453	static struct faux_device_ops psci_cpuidle_ops = {
166bf835	454	.probe = psci_cpuidle_probe,
166bf835 UH	455	};
166bf835 UH	456
5836ebeb SH	457	static bool __init dt_idle_state_present(void)
5836ebeb SH	458	{
39cdf87a DC	459	struct device_node *cpu_node __free(device_node) =
39cdf87a DC	460	of_cpu_device_node_get(cpumask_first(cpu_possible_mask));
5836ebeb SH	461	if (!cpu_node)
	462	return false;
	463
39cdf87a DC	464	struct device_node *state_node __free(device_node) =
39cdf87a DC	465	of_get_cpu_state_node(cpu_node, 0);
5836ebeb SH	466	if (!state_node)
	467	return false;
	468
	469	return !!of_match_node(psci_idle_state_match, state_node);
	470	}
	471
166bf835 UH	472	static int __init psci_idle_init(void)
166bf835 UH	473	{
af5376a7	474	struct faux_device *fdev;
166bf835	475
5836ebeb SH	476	if (!dt_idle_state_present())
5836ebeb SH	477	return 0;
166bf835	478
af5376a7 SH	479	fdev = faux_device_create("psci-cpuidle", NULL, &psci_cpuidle_ops);
	480	if (!fdev) {
	481	pr_err("Failed to create psci-cpuidle device\n");
	482	return -ENODEV;
166bf835 UH	483	}
	484
	485	return 0;
	486	}
81d549e0	487	device_initcall(psci_idle_init);