summaryrefslogtreecommitdiff
path: root/drivers/cpuidle/cpuidle-psci-domain.c
blob: b6ab0415f450af03180bf52ad30063b43f6a5b6e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
// 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)
{
	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->power_off = psci_pd_power_off;
	pd->states = states;
	pd->state_count = state_count;
	pd->flags |= GENPD_FLAG_IRQ_SAFE | GENPD_FLAG_CPU_DOMAIN;

	/* 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, bool add)
{
	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 = add ? of_genpd_add_subdomain(&parent, &child) :
			of_genpd_remove_subdomain(&parent, &child);
		of_node_put(parent.np);
		if (ret) {
			of_node_put(node);
			return ret;
		}
	}

	return 0;
}

static int psci_pd_add_topology(struct device_node *np)
{
	return psci_pd_init_topology(np, true);
}

static void psci_pd_remove_topology(struct device_node *np)
{
	psci_pd_init_topology(np, false);
}

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;
	int ret = 0, pd_count = 0;

	if (!np)
		return -ENODEV;

	/* Currently limit the hierarchical topology to be used in OSI mode. */
	if (!psci_has_osi_support())
		return 0;

	/*
	 * 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);
		if (ret)
			goto put_node;

		pd_count++;
	}

	/* Bail out if not using the hierarchical CPU topology. */
	if (!pd_count)
		return 0;

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

	/* Try to enable OSI mode. */
	ret = psci_set_osi_mode(true);
	if (ret) {
		pr_warn("failed to enable OSI mode: %d\n", ret);
		psci_pd_remove_topology(np);
		goto remove_pd;
	}

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

put_node:
	of_node_put(node);
remove_pd:
	if (pd_count)
		psci_pd_remove();
	pr_err("failed to create CPU PM domains ret=%d\n", ret);
	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);

	return dev;
}

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

	dev_pm_domain_detach(dev, false);
}