1/*
2 * sysfs.c - sysfs support
3 *
4 * (C) 2006-2007 Shaohua Li <shaohua.li@intel.com>
5 *
6 * This code is licenced under the GPL.
7 */
8
9#include <linux/kernel.h>
10#include <linux/cpuidle.h>
11#include <linux/sysfs.h>
12#include <linux/slab.h>
13#include <linux/cpu.h>
14
15#include "cpuidle.h"
16
17static unsigned int sysfs_switch;
18static int __init cpuidle_sysfs_setup(char *unused)
19{
20	sysfs_switch = 1;
21	return 1;
22}
23__setup("cpuidle_sysfs_switch", cpuidle_sysfs_setup);
24
25static ssize_t show_available_governors(struct device *dev,
26					struct device_attribute *attr,
27					char *buf)
28{
29	ssize_t i = 0;
30	struct cpuidle_governor *tmp;
31
32	mutex_lock(&cpuidle_lock);
33	list_for_each_entry(tmp, &cpuidle_governors, governor_list) {
34		if (i >= (ssize_t) ((PAGE_SIZE/sizeof(char)) - CPUIDLE_NAME_LEN - 2))
35			goto out;
36		i += scnprintf(&buf[i], CPUIDLE_NAME_LEN, "%s ", tmp->name);
37	}
38
39out:
40	i+= sprintf(&buf[i], "\n");
41	mutex_unlock(&cpuidle_lock);
42	return i;
43}
44
45static ssize_t show_current_driver(struct device *dev,
46				   struct device_attribute *attr,
47				   char *buf)
48{
49	ssize_t ret;
50	struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver();
51
52	spin_lock(&cpuidle_driver_lock);
53	if (cpuidle_driver)
54		ret = sprintf(buf, "%s\n", cpuidle_driver->name);
55	else
56		ret = sprintf(buf, "none\n");
57	spin_unlock(&cpuidle_driver_lock);
58
59	return ret;
60}
61
62static ssize_t show_current_governor(struct device *dev,
63				     struct device_attribute *attr,
64				     char *buf)
65{
66	ssize_t ret;
67
68	mutex_lock(&cpuidle_lock);
69	if (cpuidle_curr_governor)
70		ret = sprintf(buf, "%s\n", cpuidle_curr_governor->name);
71	else
72		ret = sprintf(buf, "none\n");
73	mutex_unlock(&cpuidle_lock);
74
75	return ret;
76}
77
78static ssize_t store_current_governor(struct device *dev,
79				      struct device_attribute *attr,
80				      const char *buf, size_t count)
81{
82	char gov_name[CPUIDLE_NAME_LEN];
83	int ret = -EINVAL;
84	size_t len = count;
85	struct cpuidle_governor *gov;
86
87	if (!len || len >= sizeof(gov_name))
88		return -EINVAL;
89
90	memcpy(gov_name, buf, len);
91	gov_name[len] = '\0';
92	if (gov_name[len - 1] == '\n')
93		gov_name[--len] = '\0';
94
95	mutex_lock(&cpuidle_lock);
96
97	list_for_each_entry(gov, &cpuidle_governors, governor_list) {
98		if (strlen(gov->name) == len && !strcmp(gov->name, gov_name)) {
99			ret = cpuidle_switch_governor(gov);
100			break;
101		}
102	}
103
104	mutex_unlock(&cpuidle_lock);
105
106	if (ret)
107		return ret;
108	else
109		return count;
110}
111
112static DEVICE_ATTR(current_driver, 0444, show_current_driver, NULL);
113static DEVICE_ATTR(current_governor_ro, 0444, show_current_governor, NULL);
114
115static struct attribute *cpuidle_default_attrs[] = {
116	&dev_attr_current_driver.attr,
117	&dev_attr_current_governor_ro.attr,
118	NULL
119};
120
121static DEVICE_ATTR(available_governors, 0444, show_available_governors, NULL);
122static DEVICE_ATTR(current_governor, 0644, show_current_governor,
123		   store_current_governor);
124
125static struct attribute *cpuidle_switch_attrs[] = {
126	&dev_attr_available_governors.attr,
127	&dev_attr_current_driver.attr,
128	&dev_attr_current_governor.attr,
129	NULL
130};
131
132static struct attribute_group cpuidle_attr_group = {
133	.attrs = cpuidle_default_attrs,
134	.name = "cpuidle",
135};
136
137/**
138 * cpuidle_add_interface - add CPU global sysfs attributes
139 */
140int cpuidle_add_interface(struct device *dev)
141{
142	if (sysfs_switch)
143		cpuidle_attr_group.attrs = cpuidle_switch_attrs;
144
145	return sysfs_create_group(&dev->kobj, &cpuidle_attr_group);
146}
147
148/**
149 * cpuidle_remove_interface - remove CPU global sysfs attributes
150 */
151void cpuidle_remove_interface(struct device *dev)
152{
153	sysfs_remove_group(&dev->kobj, &cpuidle_attr_group);
154}
155
156struct cpuidle_attr {
157	struct attribute attr;
158	ssize_t (*show)(struct cpuidle_device *, char *);
159	ssize_t (*store)(struct cpuidle_device *, const char *, size_t count);
160};
161
162#define define_one_ro(_name, show) \
163	static struct cpuidle_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
164#define define_one_rw(_name, show, store) \
165	static struct cpuidle_attr attr_##_name = __ATTR(_name, 0644, show, store)
166
167#define kobj_to_cpuidledev(k) container_of(k, struct cpuidle_device, kobj)
168#define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
169static ssize_t cpuidle_show(struct kobject * kobj, struct attribute * attr ,char * buf)
170{
171	int ret = -EIO;
172	struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
173	struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr);
174
175	if (cattr->show) {
176		mutex_lock(&cpuidle_lock);
177		ret = cattr->show(dev, buf);
178		mutex_unlock(&cpuidle_lock);
179	}
180	return ret;
181}
182
183static ssize_t cpuidle_store(struct kobject * kobj, struct attribute * attr,
184		     const char * buf, size_t count)
185{
186	int ret = -EIO;
187	struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
188	struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr);
189
190	if (cattr->store) {
191		mutex_lock(&cpuidle_lock);
192		ret = cattr->store(dev, buf, count);
193		mutex_unlock(&cpuidle_lock);
194	}
195	return ret;
196}
197
198static const struct sysfs_ops cpuidle_sysfs_ops = {
199	.show = cpuidle_show,
200	.store = cpuidle_store,
201};
202
203static void cpuidle_sysfs_release(struct kobject *kobj)
204{
205	struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
206
207	complete(&dev->kobj_unregister);
208}
209
210static struct kobj_type ktype_cpuidle = {
211	.sysfs_ops = &cpuidle_sysfs_ops,
212	.release = cpuidle_sysfs_release,
213};
214
215struct cpuidle_state_attr {
216	struct attribute attr;
217	ssize_t (*show)(struct cpuidle_state *, \
218					struct cpuidle_state_usage *, char *);
219	ssize_t (*store)(struct cpuidle_state *, const char *, size_t);
220};
221
222#define define_one_state_ro(_name, show) \
223static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
224
225#define define_show_state_function(_name) \
226static ssize_t show_state_##_name(struct cpuidle_state *state, \
227			 struct cpuidle_state_usage *state_usage, char *buf) \
228{ \
229	return sprintf(buf, "%u\n", state->_name);\
230}
231
232#define define_show_state_ull_function(_name) \
233static ssize_t show_state_##_name(struct cpuidle_state *state, \
234			struct cpuidle_state_usage *state_usage, char *buf) \
235{ \
236	return sprintf(buf, "%llu\n", state_usage->_name);\
237}
238
239#define define_show_state_str_function(_name) \
240static ssize_t show_state_##_name(struct cpuidle_state *state, \
241			struct cpuidle_state_usage *state_usage, char *buf) \
242{ \
243	if (state->_name[0] == '\0')\
244		return sprintf(buf, "<null>\n");\
245	return sprintf(buf, "%s\n", state->_name);\
246}
247
248define_show_state_function(exit_latency)
249define_show_state_function(power_usage)
250define_show_state_ull_function(usage)
251define_show_state_ull_function(time)
252define_show_state_str_function(name)
253define_show_state_str_function(desc)
254
255define_one_state_ro(name, show_state_name);
256define_one_state_ro(desc, show_state_desc);
257define_one_state_ro(latency, show_state_exit_latency);
258define_one_state_ro(power, show_state_power_usage);
259define_one_state_ro(usage, show_state_usage);
260define_one_state_ro(time, show_state_time);
261
262static struct attribute *cpuidle_state_default_attrs[] = {
263	&attr_name.attr,
264	&attr_desc.attr,
265	&attr_latency.attr,
266	&attr_power.attr,
267	&attr_usage.attr,
268	&attr_time.attr,
269	NULL
270};
271
272#define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
273#define kobj_to_state(k) (kobj_to_state_obj(k)->state)
274#define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
275#define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
276static ssize_t cpuidle_state_show(struct kobject * kobj,
277	struct attribute * attr ,char * buf)
278{
279	int ret = -EIO;
280	struct cpuidle_state *state = kobj_to_state(kobj);
281	struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
282	struct cpuidle_state_attr * cattr = attr_to_stateattr(attr);
283
284	if (cattr->show)
285		ret = cattr->show(state, state_usage, buf);
286
287	return ret;
288}
289
290static const struct sysfs_ops cpuidle_state_sysfs_ops = {
291	.show = cpuidle_state_show,
292};
293
294static void cpuidle_state_sysfs_release(struct kobject *kobj)
295{
296	struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
297
298	complete(&state_obj->kobj_unregister);
299}
300
301static struct kobj_type ktype_state_cpuidle = {
302	.sysfs_ops = &cpuidle_state_sysfs_ops,
303	.default_attrs = cpuidle_state_default_attrs,
304	.release = cpuidle_state_sysfs_release,
305};
306
307static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
308{
309	kobject_put(&device->kobjs[i]->kobj);
310	wait_for_completion(&device->kobjs[i]->kobj_unregister);
311	kfree(device->kobjs[i]);
312	device->kobjs[i] = NULL;
313}
314
315/**
316 * cpuidle_add_driver_sysfs - adds driver-specific sysfs attributes
317 * @device: the target device
318 */
319int cpuidle_add_state_sysfs(struct cpuidle_device *device)
320{
321	int i, ret = -ENOMEM;
322	struct cpuidle_state_kobj *kobj;
323	struct cpuidle_driver *drv = cpuidle_get_driver();
324
325	/* state statistics */
326	for (i = 0; i < device->state_count; i++) {
327		kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
328		if (!kobj)
329			goto error_state;
330		kobj->state = &drv->states[i];
331		kobj->state_usage = &device->states_usage[i];
332		init_completion(&kobj->kobj_unregister);
333
334		ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle, &device->kobj,
335					   "state%d", i);
336		if (ret) {
337			kfree(kobj);
338			goto error_state;
339		}
340		kobject_uevent(&kobj->kobj, KOBJ_ADD);
341		device->kobjs[i] = kobj;
342	}
343
344	return 0;
345
346error_state:
347	for (i = i - 1; i >= 0; i--)
348		cpuidle_free_state_kobj(device, i);
349	return ret;
350}
351
352/**
353 * cpuidle_remove_driver_sysfs - removes driver-specific sysfs attributes
354 * @device: the target device
355 */
356void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
357{
358	int i;
359
360	for (i = 0; i < device->state_count; i++)
361		cpuidle_free_state_kobj(device, i);
362}
363
364/**
365 * cpuidle_add_sysfs - creates a sysfs instance for the target device
366 * @dev: the target device
367 */
368int cpuidle_add_sysfs(struct device *cpu_dev)
369{
370	int cpu = cpu_dev->id;
371	struct cpuidle_device *dev;
372	int error;
373
374	dev = per_cpu(cpuidle_devices, cpu);
375	error = kobject_init_and_add(&dev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
376				     "cpuidle");
377	if (!error)
378		kobject_uevent(&dev->kobj, KOBJ_ADD);
379	return error;
380}
381
382/**
383 * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
384 * @dev: the target device
385 */
386void cpuidle_remove_sysfs(struct device *cpu_dev)
387{
388	int cpu = cpu_dev->id;
389	struct cpuidle_device *dev;
390
391	dev = per_cpu(cpuidle_devices, cpu);
392	kobject_put(&dev->kobj);
393}
394