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

// SPDX-License-Identifier: GPL-2.0
/*
 * PM domains for CPUs via genpd - managed by cpuidle-psci.
 *
 * Copyright (C) 2019 Linaro Ltd.
 * Author: Ulf Hansson <ulf.hansson@linaro.org>
 *
 */

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

#include <linux/cpu.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/pm_domain.h>
#include <linux/pm_runtime.h>
#include <linux/psci.h>
#include <linux/slab.h>
#include <linux/string.h>

#include "cpuidle-psci.h"

struct psci_pd_provider {
	struct list_head link;
	struct device_node *node;
};

static LIST_HEAD(psci_pd_providers);
static bool psci_pd_allow_domain_state;

static int psci_pd_power_off(struct generic_pm_domain *pd)
{
	struct genpd_power_state *state = &pd->states[pd->state_idx];
	u32 *pd_state;

	if (!state->data)
		return 0;

	if (!psci_pd_allow_domain_state)
		return -EBUSY;

	/* OSI mode is enabled, set the corresponding domain state. */
	pd_state = state->data;
	psci_set_domain_state(*pd_state);

	return 0;
}

static int psci_pd_parse_state_nodes(struct genpd_power_state *states,
				     int state_count)
{
	int i, ret;
	u32 psci_state, *psci_state_buf;

	for (i = 0; i < state_count; i++) {
		ret = psci_dt_parse_state_node(to_of_node(states[i].fwnode),
					&psci_state);
		if (ret)
			goto free_state;

		psci_state_buf = kmalloc(sizeof(u32), GFP_KERNEL);
		if (!psci_state_buf) {
			ret = -ENOMEM;
			goto free_state;
		}
		*psci_state_buf = psci_state;
		states[i].data = psci_state_buf;
	}

	return 0;

free_state:
	i--;
	for (; i >= 0; i--)
		kfree(states[i].data);
	return ret;
}

static int psci_pd_parse_states(struct device_node *np,
			struct genpd_power_state **states, int *state_count)
{
	int ret;

	/* Parse the domain idle states. */
	ret = of_genpd_parse_idle_states(np, states, state_count);
	if (ret)
		return ret;

	/* Fill out the PSCI specifics for each found state. */
	ret = psci_pd_parse_state_nodes(*states, *state_count);
	if (ret)
		kfree(*states);

	return ret;
}

static void psci_pd_free_states(struct genpd_power_state *states,
				unsigned int state_count)
{
	int i;

	for (i = 0; i < state_count; i++)
		kfree(states[i].data);
	kfree(states);
}

static int psci_pd_init(struct device_node *np, bool use_osi)
{
	struct generic_pm_domain *pd;
	struct psci_pd_provider *pd_provider;
	struct dev_power_governor *pd_gov;
	struct genpd_power_state *states = NULL;
	int ret = -ENOMEM, state_count = 0;

	pd = kzalloc(sizeof(*pd), GFP_KERNEL);
	if (!pd)
		goto out;

	pd_provider = kzalloc(sizeof(*pd_provider), GFP_KERNEL);
	if (!pd_provider)
		goto free_pd;

	pd->name = kasprintf(GFP_KERNEL, "%pOF", np);
	if (!pd->name)
		goto free_pd_prov;

	/*
	 * Parse the domain idle states and let genpd manage the state selection
	 * for those being compatible with "domain-idle-state".
	 */
	ret = psci_pd_parse_states(np, &states, &state_count);
	if (ret)
		goto free_name;

	pd->free_states = psci_pd_free_states;
	pd->name = kbasename(pd->name);
	pd->states = states;
	pd->state_count = state_count;
	pd->flags |= GENPD_FLAG_IRQ_SAFE | GENPD_FLAG_CPU_DOMAIN;

	/* Allow power off when OSI has been successfully enabled. */
	if (use_osi)
		pd->power_off = psci_pd_power_off;
	else
		pd->flags |= GENPD_FLAG_ALWAYS_ON;

	/* Use governor for CPU PM domains if it has some states to manage. */
	pd_gov = state_count > 0 ? &pm_domain_cpu_gov : NULL;

	ret = pm_genpd_init(pd, pd_gov, false);
	if (ret) {
		psci_pd_free_states(states, state_count);
		goto free_name;
	}

	ret = of_genpd_add_provider_simple(np, pd);
	if (ret)
		goto remove_pd;

	pd_provider->node = of_node_get(np);
	list_add(&pd_provider->link, &psci_pd_providers);

	pr_debug("init PM domain %s\n", pd->name);
	return 0;

remove_pd:
	pm_genpd_remove(pd);
free_name:
	kfree(pd->name);
free_pd_prov:
	kfree(pd_provider);
free_pd:
	kfree(pd);
out:
	pr_err("failed to init PM domain ret=%d %pOF\n", ret, np);
	return ret;
}

static void psci_pd_remove(void)
{
	struct psci_pd_provider *pd_provider, *it;
	struct generic_pm_domain *genpd;

	list_for_each_entry_safe(pd_provider, it, &psci_pd_providers, link) {
		of_genpd_del_provider(pd_provider->node);

		genpd = of_genpd_remove_last(pd_provider->node);
		if (!IS_ERR(genpd))
			kfree(genpd);

		of_node_put(pd_provider->node);
		list_del(&pd_provider->link);
		kfree(pd_provider);
	}
}

static int psci_pd_init_topology(struct device_node *np)
{
	struct device_node *node;
	struct of_phandle_args child, parent;
	int ret;

	for_each_child_of_node(np, node) {
		if (of_parse_phandle_with_args(node, "power-domains",
					"#power-domain-cells", 0, &parent))
			continue;

		child.np = node;
		child.args_count = 0;
		ret = of_genpd_add_subdomain(&parent, &child);
		of_node_put(parent.np);
		if (ret) {
			of_node_put(node);
			return ret;
		}
	}

	return 0;
}

static bool psci_pd_try_set_osi_mode(void)
{
	int ret;

	if (!psci_has_osi_support())
		return false;

	ret = psci_set_osi_mode(true);
	if (ret) {
		pr_warn("failed to enable OSI mode: %d\n", ret);
		return false;
	}

	return true;
}

static void psci_cpuidle_domain_sync_state(struct device *dev)
{
	/*
	 * All devices have now been attached/probed to the PM domain topology,
	 * hence it's fine to allow domain states to be picked.
	 */
	psci_pd_allow_domain_state = true;
}

static const struct of_device_id psci_of_match[] = {
	{ .compatible = "arm,psci-1.0" },
	{}
};

static int psci_cpuidle_domain_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	struct device_node *node;
	bool use_osi;
	int ret = 0, pd_count = 0;

	if (!np)
		return -ENODEV;

	/* If OSI mode is supported, let's try to enable it. */
	use_osi = psci_pd_try_set_osi_mode();

	/*
	 * Parse child nodes for the "#power-domain-cells" property and
	 * initialize a genpd/genpd-of-provider pair when it's found.
	 */
	for_each_child_of_node(np, node) {
		if (!of_find_property(node, "#power-domain-cells", NULL))
			continue;

		ret = psci_pd_init(node, use_osi);
		if (ret)
			goto put_node;

		pd_count++;
	}

	/* Bail out if not using the hierarchical CPU topology. */
	if (!pd_count)
		goto no_pd;

	/* Link genpd masters/subdomains to model the CPU topology. */
	ret = psci_pd_init_topology(np);
	if (ret)
		goto remove_pd;

	pr_info("Initialized CPU PM domain topology\n");
	return 0;

put_node:
	of_node_put(node);
remove_pd:
	psci_pd_remove();
	pr_err("failed to create CPU PM domains ret=%d\n", ret);
no_pd:
	if (use_osi)
		psci_set_osi_mode(false);
	return ret;
}

static struct platform_driver psci_cpuidle_domain_driver = {
	.probe  = psci_cpuidle_domain_probe,
	.driver = {
		.name = "psci-cpuidle-domain",
		.of_match_table = psci_of_match,
		.sync_state = psci_cpuidle_domain_sync_state,
	},
};

static int __init psci_idle_init_domains(void)
{
	return platform_driver_register(&psci_cpuidle_domain_driver);
}
subsys_initcall(psci_idle_init_domains);

struct device *psci_dt_attach_cpu(int cpu)
{
	struct device *dev;

	dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), "psci");
	if (IS_ERR_OR_NULL(dev))
		return dev;

	pm_runtime_irq_safe(dev);
	if (cpu_online(cpu))
		pm_runtime_get_sync(dev);

	dev_pm_syscore_device(dev, true);

	return dev;
}

void psci_dt_detach_cpu(struct device *dev)
{
	if (IS_ERR_OR_NULL(dev))
		return;

	dev_pm_domain_detach(dev, false);
}
Commit	Line	Data
a5e0454c UH	1	// SPDX-License-Identifier: GPL-2.0
	2	/*
	3	* PM domains for CPUs via genpd - managed by cpuidle-psci.
	4	*
	5	* Copyright (C) 2019 Linaro Ltd.
	6	* Author: Ulf Hansson <ulf.hansson@linaro.org>
	7	*
	8	*/
	9
a65a397f UH	10	#define pr_fmt(fmt) "CPUidle PSCI: " fmt
a65a397f UH	11
a5e0454c UH	12	#include <linux/cpu.h>
	13	#include <linux/device.h>
	14	#include <linux/kernel.h>
ee7c34ca	15	#include <linux/platform_device.h>
a5e0454c UH	16	#include <linux/pm_domain.h>
a5e0454c UH	17	#include <linux/pm_runtime.h>
a65a397f UH	18	#include <linux/psci.h>
	19	#include <linux/slab.h>
	20	#include <linux/string.h>
a5e0454c UH	21
	22	#include "cpuidle-psci.h"
	23
a65a397f UH	24	struct psci_pd_provider {
	25	struct list_head link;
	26	struct device_node *node;
	27	};
	28
	29	static LIST_HEAD(psci_pd_providers);
81f94ddf	30	static bool psci_pd_allow_domain_state;
a65a397f UH	31
	32	static int psci_pd_power_off(struct generic_pm_domain *pd)
	33	{
	34	struct genpd_power_state *state = &pd->states[pd->state_idx];
	35	u32 *pd_state;
	36
	37	if (!state->data)
	38	return 0;
	39
81f94ddf UH	40	if (!psci_pd_allow_domain_state)
	41	return -EBUSY;
	42
a65a397f UH	43	/* OSI mode is enabled, set the corresponding domain state. */
	44	pd_state = state->data;
	45	psci_set_domain_state(*pd_state);
	46
	47	return 0;
	48	}
	49
ee7c34ca UH	50	static int psci_pd_parse_state_nodes(struct genpd_power_state *states,
ee7c34ca UH	51	int state_count)
a65a397f UH	52	{
	53	int i, ret;
	54	u32 psci_state, *psci_state_buf;
	55
	56	for (i = 0; i < state_count; i++) {
	57	ret = psci_dt_parse_state_node(to_of_node(states[i].fwnode),
	58	&psci_state);
	59	if (ret)
	60	goto free_state;
	61
	62	psci_state_buf = kmalloc(sizeof(u32), GFP_KERNEL);
	63	if (!psci_state_buf) {
	64	ret = -ENOMEM;
	65	goto free_state;
	66	}
	67	*psci_state_buf = psci_state;
	68	states[i].data = psci_state_buf;
	69	}
	70
	71	return 0;
	72
	73	free_state:
	74	i--;
	75	for (; i >= 0; i--)
	76	kfree(states[i].data);
	77	return ret;
	78	}
	79
ee7c34ca	80	static int psci_pd_parse_states(struct device_node *np,
a65a397f UH	81	struct genpd_power_state *states, int state_count)
	82	{
	83	int ret;
	84
	85	/* Parse the domain idle states. */
	86	ret = of_genpd_parse_idle_states(np, states, state_count);
	87	if (ret)
	88	return ret;
	89
	90	/* Fill out the PSCI specifics for each found state. */
	91	ret = psci_pd_parse_state_nodes(states, state_count);
	92	if (ret)
	93	kfree(*states);
	94
	95	return ret;
	96	}
	97
	98	static void psci_pd_free_states(struct genpd_power_state *states,
	99	unsigned int state_count)
	100	{
	101	int i;
	102
	103	for (i = 0; i < state_count; i++)
	104	kfree(states[i].data);
	105	kfree(states);
	106	}
	107
70c179b4	108	static int psci_pd_init(struct device_node *np, bool use_osi)
a65a397f UH	109	{
	110	struct generic_pm_domain *pd;
	111	struct psci_pd_provider *pd_provider;
	112	struct dev_power_governor *pd_gov;
	113	struct genpd_power_state *states = NULL;
	114	int ret = -ENOMEM, state_count = 0;
	115
	116	pd = kzalloc(sizeof(*pd), GFP_KERNEL);
	117	if (!pd)
	118	goto out;
	119
	120	pd_provider = kzalloc(sizeof(*pd_provider), GFP_KERNEL);
	121	if (!pd_provider)
	122	goto free_pd;
	123
	124	pd->name = kasprintf(GFP_KERNEL, "%pOF", np);
	125	if (!pd->name)
	126	goto free_pd_prov;
	127
	128	/*
	129	* Parse the domain idle states and let genpd manage the state selection
	130	* for those being compatible with "domain-idle-state".
	131	*/
	132	ret = psci_pd_parse_states(np, &states, &state_count);
	133	if (ret)
	134	goto free_name;
	135
	136	pd->free_states = psci_pd_free_states;
	137	pd->name = kbasename(pd->name);
a65a397f UH	138	pd->states = states;
	139	pd->state_count = state_count;
	140	pd->flags \|= GENPD_FLAG_IRQ_SAFE \| GENPD_FLAG_CPU_DOMAIN;
	141
70c179b4 UH	142	/* Allow power off when OSI has been successfully enabled. */
	143	if (use_osi)
	144	pd->power_off = psci_pd_power_off;
	145	else
	146	pd->flags \|= GENPD_FLAG_ALWAYS_ON;
	147
a65a397f UH	148	/* Use governor for CPU PM domains if it has some states to manage. */
	149	pd_gov = state_count > 0 ? &pm_domain_cpu_gov : NULL;
	150
	151	ret = pm_genpd_init(pd, pd_gov, false);
	152	if (ret) {
	153	psci_pd_free_states(states, state_count);
	154	goto free_name;
	155	}
	156
	157	ret = of_genpd_add_provider_simple(np, pd);
	158	if (ret)
	159	goto remove_pd;
	160
	161	pd_provider->node = of_node_get(np);
	162	list_add(&pd_provider->link, &psci_pd_providers);
	163
	164	pr_debug("init PM domain %s\n", pd->name);
	165	return 0;
	166
	167	remove_pd:
	168	pm_genpd_remove(pd);
	169	free_name:
	170	kfree(pd->name);
	171	free_pd_prov:
	172	kfree(pd_provider);
	173	free_pd:
	174	kfree(pd);
	175	out:
	176	pr_err("failed to init PM domain ret=%d %pOF\n", ret, np);
	177	return ret;
	178	}
	179
ee7c34ca	180	static void psci_pd_remove(void)
a65a397f UH	181	{
	182	struct psci_pd_provider pd_provider, it;
	183	struct generic_pm_domain *genpd;
	184
	185	list_for_each_entry_safe(pd_provider, it, &psci_pd_providers, link) {
	186	of_genpd_del_provider(pd_provider->node);
	187
	188	genpd = of_genpd_remove_last(pd_provider->node);
	189	if (!IS_ERR(genpd))
	190	kfree(genpd);
	191
	192	of_node_put(pd_provider->node);
	193	list_del(&pd_provider->link);
	194	kfree(pd_provider);
	195	}
	196	}
	197
70c179b4	198	static int psci_pd_init_topology(struct device_node *np)
a65a397f UH	199	{
	200	struct device_node *node;
	201	struct of_phandle_args child, parent;
	202	int ret;
	203
	204	for_each_child_of_node(np, node) {
	205	if (of_parse_phandle_with_args(node, "power-domains",
	206	"#power-domain-cells", 0, &parent))
	207	continue;
	208
	209	child.np = node;
	210	child.args_count = 0;
70c179b4	211	ret = of_genpd_add_subdomain(&parent, &child);
a65a397f UH	212	of_node_put(parent.np);
	213	if (ret) {
	214	of_node_put(node);
	215	return ret;
	216	}
	217	}
	218
	219	return 0;
	220	}
	221
70c179b4	222	static bool psci_pd_try_set_osi_mode(void)
a65a397f	223	{
70c179b4	224	int ret;
a65a397f	225
70c179b4 UH	226	if (!psci_has_osi_support())
	227	return false;
	228
	229	ret = psci_set_osi_mode(true);
	230	if (ret) {
	231	pr_warn("failed to enable OSI mode: %d\n", ret);
	232	return false;
	233	}
	234
	235	return true;
a65a397f UH	236	}
a65a397f UH	237
81f94ddf UH	238	static void psci_cpuidle_domain_sync_state(struct device *dev)
	239	{
	240	/*
	241	* All devices have now been attached/probed to the PM domain topology,
	242	* hence it's fine to allow domain states to be picked.
	243	*/
	244	psci_pd_allow_domain_state = true;
	245	}
	246
ee7c34ca	247	static const struct of_device_id psci_of_match[] = {
a65a397f UH	248	{ .compatible = "arm,psci-1.0" },
	249	{}
	250	};
	251
ee7c34ca	252	static int psci_cpuidle_domain_probe(struct platform_device *pdev)
a65a397f	253	{
ee7c34ca	254	struct device_node *np = pdev->dev.of_node;
a65a397f	255	struct device_node *node;
70c179b4	256	bool use_osi;
a65a397f UH	257	int ret = 0, pd_count = 0;
	258
	259	if (!np)
	260	return -ENODEV;
	261
70c179b4 UH	262	/* If OSI mode is supported, let's try to enable it. */
70c179b4 UH	263	use_osi = psci_pd_try_set_osi_mode();
a65a397f UH	264
	265	/*
	266	* Parse child nodes for the "#power-domain-cells" property and
	267	* initialize a genpd/genpd-of-provider pair when it's found.
	268	*/
	269	for_each_child_of_node(np, node) {
	270	if (!of_find_property(node, "#power-domain-cells", NULL))
	271	continue;
	272
70c179b4	273	ret = psci_pd_init(node, use_osi);
a65a397f UH	274	if (ret)
	275	goto put_node;
	276
	277	pd_count++;
	278	}
	279
	280	/* Bail out if not using the hierarchical CPU topology. */
	281	if (!pd_count)
70c179b4	282	goto no_pd;
a65a397f UH	283
a65a397f UH	284	/* Link genpd masters/subdomains to model the CPU topology. */
70c179b4	285	ret = psci_pd_init_topology(np);
a65a397f UH	286	if (ret)
	287	goto remove_pd;
	288
a65a397f	289	pr_info("Initialized CPU PM domain topology\n");
ee7c34ca	290	return 0;
a65a397f UH	291
	292	put_node:
	293	of_node_put(node);
	294	remove_pd:
70c179b4	295	psci_pd_remove();
a65a397f	296	pr_err("failed to create CPU PM domains ret=%d\n", ret);
70c179b4 UH	297	no_pd:
	298	if (use_osi)
	299	psci_set_osi_mode(false);
a65a397f UH	300	return ret;
a65a397f UH	301	}
ee7c34ca UH	302
	303	static struct platform_driver psci_cpuidle_domain_driver = {
	304	.probe = psci_cpuidle_domain_probe,
	305	.driver = {
	306	.name = "psci-cpuidle-domain",
	307	.of_match_table = psci_of_match,
81f94ddf	308	.sync_state = psci_cpuidle_domain_sync_state,
ee7c34ca UH	309	},
	310	};
	311
	312	static int __init psci_idle_init_domains(void)
	313	{
	314	return platform_driver_register(&psci_cpuidle_domain_driver);
	315	}
a65a397f UH	316	subsys_initcall(psci_idle_init_domains);
a65a397f UH	317
166bf835	318	struct device *psci_dt_attach_cpu(int cpu)
a5e0454c UH	319	{
	320	struct device *dev;
	321
	322	dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), "psci");
	323	if (IS_ERR_OR_NULL(dev))
	324	return dev;
	325
	326	pm_runtime_irq_safe(dev);
	327	if (cpu_online(cpu))
	328	pm_runtime_get_sync(dev);
	329
670c90de UH	330	dev_pm_syscore_device(dev, true);
670c90de UH	331
a5e0454c UH	332	return dev;
a5e0454c UH	333	}
166bf835 UH	334
	335	void psci_dt_detach_cpu(struct device *dev)
	336	{
	337	if (IS_ERR_OR_NULL(dev))
	338	return;
	339
	340	dev_pm_domain_detach(dev, false);
	341	}