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46bcfad7a8
This patch makes the cpuidle_states structure global (single copy) instead of per-cpu. The statistics needed on per-cpu basis by the governor are kept per-cpu. This simplifies the cpuidle subsystem as state registration is done by single cpu only. Having single copy of cpuidle_states saves memory. Rare case of asymmetric C-states can be handled within the cpuidle driver and architectures such as POWER do not have asymmetric C-states. Having single/global registration of all the idle states, dynamic C-state transitions on x86 are handled by the boot cpu. Here, the boot cpu would disable all the devices, re-populate the states and later enable all the devices, irrespective of the cpu that would receive the notification first. Reference: https://lkml.org/lkml/2011/4/25/83 Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com> Signed-off-by: Trinabh Gupta <g.trinabh@gmail.com> Tested-by: Jean Pihet <j-pihet@ti.com> Reviewed-by: Kevin Hilman <khilman@ti.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Len Brown <len.brown@intel.com>
396 lines
10 KiB
C
396 lines
10 KiB
C
/*
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* sysfs.c - sysfs support
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*
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* (C) 2006-2007 Shaohua Li <shaohua.li@intel.com>
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*
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* This code is licenced under the GPL.
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*/
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#include <linux/kernel.h>
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#include <linux/cpuidle.h>
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#include <linux/sysfs.h>
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#include <linux/slab.h>
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#include <linux/cpu.h>
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#include "cpuidle.h"
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static unsigned int sysfs_switch;
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static int __init cpuidle_sysfs_setup(char *unused)
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{
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sysfs_switch = 1;
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return 1;
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}
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__setup("cpuidle_sysfs_switch", cpuidle_sysfs_setup);
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static ssize_t show_available_governors(struct sysdev_class *class,
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struct sysdev_class_attribute *attr,
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char *buf)
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{
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ssize_t i = 0;
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struct cpuidle_governor *tmp;
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mutex_lock(&cpuidle_lock);
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list_for_each_entry(tmp, &cpuidle_governors, governor_list) {
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if (i >= (ssize_t) ((PAGE_SIZE/sizeof(char)) - CPUIDLE_NAME_LEN - 2))
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goto out;
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i += scnprintf(&buf[i], CPUIDLE_NAME_LEN, "%s ", tmp->name);
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}
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out:
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i+= sprintf(&buf[i], "\n");
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mutex_unlock(&cpuidle_lock);
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return i;
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}
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static ssize_t show_current_driver(struct sysdev_class *class,
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struct sysdev_class_attribute *attr,
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char *buf)
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{
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ssize_t ret;
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struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver();
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spin_lock(&cpuidle_driver_lock);
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if (cpuidle_driver)
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ret = sprintf(buf, "%s\n", cpuidle_driver->name);
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else
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ret = sprintf(buf, "none\n");
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spin_unlock(&cpuidle_driver_lock);
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return ret;
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}
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static ssize_t show_current_governor(struct sysdev_class *class,
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struct sysdev_class_attribute *attr,
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char *buf)
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{
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ssize_t ret;
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mutex_lock(&cpuidle_lock);
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if (cpuidle_curr_governor)
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ret = sprintf(buf, "%s\n", cpuidle_curr_governor->name);
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else
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ret = sprintf(buf, "none\n");
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mutex_unlock(&cpuidle_lock);
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return ret;
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}
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static ssize_t store_current_governor(struct sysdev_class *class,
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struct sysdev_class_attribute *attr,
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const char *buf, size_t count)
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{
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char gov_name[CPUIDLE_NAME_LEN];
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int ret = -EINVAL;
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size_t len = count;
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struct cpuidle_governor *gov;
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if (!len || len >= sizeof(gov_name))
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return -EINVAL;
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memcpy(gov_name, buf, len);
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gov_name[len] = '\0';
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if (gov_name[len - 1] == '\n')
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gov_name[--len] = '\0';
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mutex_lock(&cpuidle_lock);
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list_for_each_entry(gov, &cpuidle_governors, governor_list) {
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if (strlen(gov->name) == len && !strcmp(gov->name, gov_name)) {
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ret = cpuidle_switch_governor(gov);
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break;
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}
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}
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mutex_unlock(&cpuidle_lock);
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if (ret)
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return ret;
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else
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return count;
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}
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static SYSDEV_CLASS_ATTR(current_driver, 0444, show_current_driver, NULL);
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static SYSDEV_CLASS_ATTR(current_governor_ro, 0444, show_current_governor,
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NULL);
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static struct attribute *cpuclass_default_attrs[] = {
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&attr_current_driver.attr,
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&attr_current_governor_ro.attr,
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NULL
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};
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static SYSDEV_CLASS_ATTR(available_governors, 0444, show_available_governors,
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NULL);
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static SYSDEV_CLASS_ATTR(current_governor, 0644, show_current_governor,
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store_current_governor);
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static struct attribute *cpuclass_switch_attrs[] = {
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&attr_available_governors.attr,
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&attr_current_driver.attr,
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&attr_current_governor.attr,
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NULL
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};
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static struct attribute_group cpuclass_attr_group = {
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.attrs = cpuclass_default_attrs,
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.name = "cpuidle",
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};
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/**
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* cpuidle_add_class_sysfs - add CPU global sysfs attributes
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*/
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int cpuidle_add_class_sysfs(struct sysdev_class *cls)
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{
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if (sysfs_switch)
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cpuclass_attr_group.attrs = cpuclass_switch_attrs;
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return sysfs_create_group(&cls->kset.kobj, &cpuclass_attr_group);
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}
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/**
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* cpuidle_remove_class_sysfs - remove CPU global sysfs attributes
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*/
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void cpuidle_remove_class_sysfs(struct sysdev_class *cls)
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{
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sysfs_remove_group(&cls->kset.kobj, &cpuclass_attr_group);
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}
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struct cpuidle_attr {
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struct attribute attr;
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ssize_t (*show)(struct cpuidle_device *, char *);
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ssize_t (*store)(struct cpuidle_device *, const char *, size_t count);
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};
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#define define_one_ro(_name, show) \
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static struct cpuidle_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
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#define define_one_rw(_name, show, store) \
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static struct cpuidle_attr attr_##_name = __ATTR(_name, 0644, show, store)
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#define kobj_to_cpuidledev(k) container_of(k, struct cpuidle_device, kobj)
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#define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
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static ssize_t cpuidle_show(struct kobject * kobj, struct attribute * attr ,char * buf)
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{
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int ret = -EIO;
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struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
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struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr);
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if (cattr->show) {
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mutex_lock(&cpuidle_lock);
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ret = cattr->show(dev, buf);
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mutex_unlock(&cpuidle_lock);
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}
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return ret;
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}
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static ssize_t cpuidle_store(struct kobject * kobj, struct attribute * attr,
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const char * buf, size_t count)
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{
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int ret = -EIO;
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struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
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struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr);
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if (cattr->store) {
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mutex_lock(&cpuidle_lock);
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ret = cattr->store(dev, buf, count);
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mutex_unlock(&cpuidle_lock);
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}
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return ret;
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}
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static const struct sysfs_ops cpuidle_sysfs_ops = {
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.show = cpuidle_show,
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.store = cpuidle_store,
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};
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static void cpuidle_sysfs_release(struct kobject *kobj)
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{
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struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
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complete(&dev->kobj_unregister);
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}
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static struct kobj_type ktype_cpuidle = {
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.sysfs_ops = &cpuidle_sysfs_ops,
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.release = cpuidle_sysfs_release,
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};
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struct cpuidle_state_attr {
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struct attribute attr;
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ssize_t (*show)(struct cpuidle_state *, \
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struct cpuidle_state_usage *, char *);
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ssize_t (*store)(struct cpuidle_state *, const char *, size_t);
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};
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#define define_one_state_ro(_name, show) \
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static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
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#define define_show_state_function(_name) \
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static ssize_t show_state_##_name(struct cpuidle_state *state, \
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struct cpuidle_state_usage *state_usage, char *buf) \
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{ \
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return sprintf(buf, "%u\n", state->_name);\
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}
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#define define_show_state_ull_function(_name) \
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static ssize_t show_state_##_name(struct cpuidle_state *state, \
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struct cpuidle_state_usage *state_usage, char *buf) \
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{ \
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return sprintf(buf, "%llu\n", state_usage->_name);\
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}
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#define define_show_state_str_function(_name) \
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static ssize_t show_state_##_name(struct cpuidle_state *state, \
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struct cpuidle_state_usage *state_usage, char *buf) \
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{ \
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if (state->_name[0] == '\0')\
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return sprintf(buf, "<null>\n");\
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return sprintf(buf, "%s\n", state->_name);\
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}
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define_show_state_function(exit_latency)
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define_show_state_function(power_usage)
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define_show_state_ull_function(usage)
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define_show_state_ull_function(time)
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define_show_state_str_function(name)
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define_show_state_str_function(desc)
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define_one_state_ro(name, show_state_name);
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define_one_state_ro(desc, show_state_desc);
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define_one_state_ro(latency, show_state_exit_latency);
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define_one_state_ro(power, show_state_power_usage);
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define_one_state_ro(usage, show_state_usage);
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define_one_state_ro(time, show_state_time);
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static struct attribute *cpuidle_state_default_attrs[] = {
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&attr_name.attr,
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&attr_desc.attr,
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&attr_latency.attr,
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&attr_power.attr,
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&attr_usage.attr,
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&attr_time.attr,
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NULL
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};
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#define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
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#define kobj_to_state(k) (kobj_to_state_obj(k)->state)
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#define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
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#define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
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static ssize_t cpuidle_state_show(struct kobject * kobj,
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struct attribute * attr ,char * buf)
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{
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int ret = -EIO;
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struct cpuidle_state *state = kobj_to_state(kobj);
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struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
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struct cpuidle_state_attr * cattr = attr_to_stateattr(attr);
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if (cattr->show)
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ret = cattr->show(state, state_usage, buf);
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return ret;
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}
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static const struct sysfs_ops cpuidle_state_sysfs_ops = {
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.show = cpuidle_state_show,
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};
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static void cpuidle_state_sysfs_release(struct kobject *kobj)
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{
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struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
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complete(&state_obj->kobj_unregister);
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}
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static struct kobj_type ktype_state_cpuidle = {
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.sysfs_ops = &cpuidle_state_sysfs_ops,
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.default_attrs = cpuidle_state_default_attrs,
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.release = cpuidle_state_sysfs_release,
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};
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static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
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{
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kobject_put(&device->kobjs[i]->kobj);
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wait_for_completion(&device->kobjs[i]->kobj_unregister);
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kfree(device->kobjs[i]);
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device->kobjs[i] = NULL;
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}
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/**
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* cpuidle_add_driver_sysfs - adds driver-specific sysfs attributes
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* @device: the target device
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*/
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int cpuidle_add_state_sysfs(struct cpuidle_device *device)
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{
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int i, ret = -ENOMEM;
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struct cpuidle_state_kobj *kobj;
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struct cpuidle_driver *drv = cpuidle_get_driver();
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/* state statistics */
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for (i = 0; i < device->state_count; i++) {
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kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
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if (!kobj)
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goto error_state;
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kobj->state = &drv->states[i];
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kobj->state_usage = &device->states_usage[i];
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init_completion(&kobj->kobj_unregister);
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ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle, &device->kobj,
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"state%d", i);
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if (ret) {
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kfree(kobj);
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goto error_state;
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}
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kobject_uevent(&kobj->kobj, KOBJ_ADD);
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device->kobjs[i] = kobj;
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}
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return 0;
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error_state:
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for (i = i - 1; i >= 0; i--)
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cpuidle_free_state_kobj(device, i);
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return ret;
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}
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/**
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* cpuidle_remove_driver_sysfs - removes driver-specific sysfs attributes
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* @device: the target device
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*/
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void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
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{
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int i;
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for (i = 0; i < device->state_count; i++)
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cpuidle_free_state_kobj(device, i);
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}
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/**
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* cpuidle_add_sysfs - creates a sysfs instance for the target device
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* @sysdev: the target device
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*/
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int cpuidle_add_sysfs(struct sys_device *sysdev)
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{
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int cpu = sysdev->id;
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struct cpuidle_device *dev;
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int error;
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dev = per_cpu(cpuidle_devices, cpu);
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error = kobject_init_and_add(&dev->kobj, &ktype_cpuidle, &sysdev->kobj,
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"cpuidle");
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if (!error)
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kobject_uevent(&dev->kobj, KOBJ_ADD);
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return error;
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}
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/**
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* cpuidle_remove_sysfs - deletes a sysfs instance on the target device
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* @sysdev: the target device
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*/
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void cpuidle_remove_sysfs(struct sys_device *sysdev)
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{
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int cpu = sysdev->id;
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struct cpuidle_device *dev;
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dev = per_cpu(cpuidle_devices, cpu);
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kobject_put(&dev->kobj);
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}
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