/* * sysfs.c - sysfs support * * (C) 2006-2007 Shaohua Li <shaohua.li@intel.com> * * This code is licenced under the GPL. */ #include <linux/kernel.h> #include <linux/cpuidle.h> #include <linux/sysfs.h> #include <linux/cpu.h> #include "cpuidle.h" static unsigned int sysfs_switch; static int __init cpuidle_sysfs_setup(char *unused) { sysfs_switch = 1; return 1; } __setup("cpuidle_sysfs_switch", cpuidle_sysfs_setup); static ssize_t show_available_governors(struct sysdev_class *class, struct sysdev_class_attribute *attr, char *buf) { ssize_t i = 0; struct cpuidle_governor *tmp; mutex_lock(&cpuidle_lock); list_for_each_entry(tmp, &cpuidle_governors, governor_list) { if (i >= (ssize_t) ((PAGE_SIZE/sizeof(char)) - CPUIDLE_NAME_LEN - 2)) goto out; i += scnprintf(&buf[i], CPUIDLE_NAME_LEN, "%s ", tmp->name); } out: i+= sprintf(&buf[i], "\n"); mutex_unlock(&cpuidle_lock); return i; } static ssize_t show_current_driver(struct sysdev_class *class, struct sysdev_class_attribute *attr, char *buf) { ssize_t ret; spin_lock(&cpuidle_driver_lock); if (cpuidle_curr_driver) ret = sprintf(buf, "%s\n", cpuidle_curr_driver->name); else ret = sprintf(buf, "none\n"); spin_unlock(&cpuidle_driver_lock); return ret; } static ssize_t show_current_governor(struct sysdev_class *class, struct sysdev_class_attribute *attr, char *buf) { ssize_t ret; mutex_lock(&cpuidle_lock); if (cpuidle_curr_governor) ret = sprintf(buf, "%s\n", cpuidle_curr_governor->name); else ret = sprintf(buf, "none\n"); mutex_unlock(&cpuidle_lock); return ret; } static ssize_t store_current_governor(struct sysdev_class *class, struct sysdev_class_attribute *attr, const char *buf, size_t count) { char gov_name[CPUIDLE_NAME_LEN]; int ret = -EINVAL; size_t len = count; struct cpuidle_governor *gov; if (!len || len >= sizeof(gov_name)) return -EINVAL; memcpy(gov_name, buf, len); gov_name[len] = '\0'; if (gov_name[len - 1] == '\n') gov_name[--len] = '\0'; mutex_lock(&cpuidle_lock); list_for_each_entry(gov, &cpuidle_governors, governor_list) { if (strlen(gov->name) == len && !strcmp(gov->name, gov_name)) { ret = cpuidle_switch_governor(gov); break; } } mutex_unlock(&cpuidle_lock); if (ret) return ret; else return count; } static SYSDEV_CLASS_ATTR(current_driver, 0444, show_current_driver, NULL); static SYSDEV_CLASS_ATTR(current_governor_ro, 0444, show_current_governor, NULL); static struct attribute *cpuclass_default_attrs[] = { &attr_current_driver.attr, &attr_current_governor_ro.attr, NULL }; static SYSDEV_CLASS_ATTR(available_governors, 0444, show_available_governors, NULL); static SYSDEV_CLASS_ATTR(current_governor, 0644, show_current_governor, store_current_governor); static struct attribute *cpuclass_switch_attrs[] = { &attr_available_governors.attr, &attr_current_driver.attr, &attr_current_governor.attr, NULL }; static struct attribute_group cpuclass_attr_group = { .attrs = cpuclass_default_attrs, .name = "cpuidle", }; /** * cpuidle_add_class_sysfs - add CPU global sysfs attributes */ int cpuidle_add_class_sysfs(struct sysdev_class *cls) { if (sysfs_switch) cpuclass_attr_group.attrs = cpuclass_switch_attrs; return sysfs_create_group(&cls->kset.kobj, &cpuclass_attr_group); } /** * cpuidle_remove_class_sysfs - remove CPU global sysfs attributes */ void cpuidle_remove_class_sysfs(struct sysdev_class *cls) { sysfs_remove_group(&cls->kset.kobj, &cpuclass_attr_group); } struct cpuidle_attr { struct attribute attr; ssize_t (*show)(struct cpuidle_device *, char *); ssize_t (*store)(struct cpuidle_device *, const char *, size_t count); }; #define define_one_ro(_name, show) \ static struct cpuidle_attr attr_##_name = __ATTR(_name, 0444, show, NULL) #define define_one_rw(_name, show, store) \ static struct cpuidle_attr attr_##_name = __ATTR(_name, 0644, show, store) #define kobj_to_cpuidledev(k) container_of(k, struct cpuidle_device, kobj) #define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr) static ssize_t cpuidle_show(struct kobject * kobj, struct attribute * attr ,char * buf) { int ret = -EIO; struct cpuidle_device *dev = kobj_to_cpuidledev(kobj); struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr); if (cattr->show) { mutex_lock(&cpuidle_lock); ret = cattr->show(dev, buf); mutex_unlock(&cpuidle_lock); } return ret; } static ssize_t cpuidle_store(struct kobject * kobj, struct attribute * attr, const char * buf, size_t count) { int ret = -EIO; struct cpuidle_device *dev = kobj_to_cpuidledev(kobj); struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr); if (cattr->store) { mutex_lock(&cpuidle_lock); ret = cattr->store(dev, buf, count); mutex_unlock(&cpuidle_lock); } return ret; } static const struct sysfs_ops cpuidle_sysfs_ops = { .show = cpuidle_show, .store = cpuidle_store, }; static void cpuidle_sysfs_release(struct kobject *kobj) { struct cpuidle_device *dev = kobj_to_cpuidledev(kobj); complete(&dev->kobj_unregister); } static struct kobj_type ktype_cpuidle = { .sysfs_ops = &cpuidle_sysfs_ops, .release = cpuidle_sysfs_release, }; struct cpuidle_state_attr { struct attribute attr; ssize_t (*show)(struct cpuidle_state *, char *); ssize_t (*store)(struct cpuidle_state *, const char *, size_t); }; #define define_one_state_ro(_name, show) \ static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL) #define define_show_state_function(_name) \ static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \ { \ return sprintf(buf, "%u\n", state->_name);\ } #define define_show_state_ull_function(_name) \ static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \ { \ return sprintf(buf, "%llu\n", state->_name);\ } #define define_show_state_str_function(_name) \ static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \ { \ if (state->_name[0] == '\0')\ return sprintf(buf, "<null>\n");\ return sprintf(buf, "%s\n", state->_name);\ } define_show_state_function(exit_latency) define_show_state_function(power_usage) define_show_state_ull_function(usage) define_show_state_ull_function(time) define_show_state_str_function(name) define_show_state_str_function(desc) define_one_state_ro(name, show_state_name); define_one_state_ro(desc, show_state_desc); define_one_state_ro(latency, show_state_exit_latency); define_one_state_ro(power, show_state_power_usage); define_one_state_ro(usage, show_state_usage); define_one_state_ro(time, show_state_time); static struct attribute *cpuidle_state_default_attrs[] = { &attr_name.attr, &attr_desc.attr, &attr_latency.attr, &attr_power.attr, &attr_usage.attr, &attr_time.attr, NULL }; #define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj) #define kobj_to_state(k) (kobj_to_state_obj(k)->state) #define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr) static ssize_t cpuidle_state_show(struct kobject * kobj, struct attribute * attr ,char * buf) { int ret = -EIO; struct cpuidle_state *state = kobj_to_state(kobj); struct cpuidle_state_attr * cattr = attr_to_stateattr(attr); if (cattr->show) ret = cattr->show(state, buf); return ret; } static const struct sysfs_ops cpuidle_state_sysfs_ops = { .show = cpuidle_state_show, }; static void cpuidle_state_sysfs_release(struct kobject *kobj) { struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj); complete(&state_obj->kobj_unregister); } static struct kobj_type ktype_state_cpuidle = { .sysfs_ops = &cpuidle_state_sysfs_ops, .default_attrs = cpuidle_state_default_attrs, .release = cpuidle_state_sysfs_release, }; static void inline cpuidle_free_state_kobj(struct cpuidle_device *device, int i) { kobject_put(&device->kobjs[i]->kobj); wait_for_completion(&device->kobjs[i]->kobj_unregister); kfree(device->kobjs[i]); device->kobjs[i] = NULL; } /** * cpuidle_add_driver_sysfs - adds driver-specific sysfs attributes * @device: the target device */ int cpuidle_add_state_sysfs(struct cpuidle_device *device) { int i, ret = -ENOMEM; struct cpuidle_state_kobj *kobj; /* state statistics */ for (i = 0; i < device->state_count; i++) { kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL); if (!kobj) goto error_state; kobj->state = &device->states[i]; init_completion(&kobj->kobj_unregister); ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle, &device->kobj, "state%d", i); if (ret) { kfree(kobj); goto error_state; } kobject_uevent(&kobj->kobj, KOBJ_ADD); device->kobjs[i] = kobj; } return 0; error_state: for (i = i - 1; i >= 0; i--) cpuidle_free_state_kobj(device, i); return ret; } /** * cpuidle_remove_driver_sysfs - removes driver-specific sysfs attributes * @device: the target device */ void cpuidle_remove_state_sysfs(struct cpuidle_device *device) { int i; for (i = 0; i < device->state_count; i++) cpuidle_free_state_kobj(device, i); } /** * cpuidle_add_sysfs - creates a sysfs instance for the target device * @sysdev: the target device */ int cpuidle_add_sysfs(struct sys_device *sysdev) { int cpu = sysdev->id; struct cpuidle_device *dev; int error; dev = per_cpu(cpuidle_devices, cpu); error = kobject_init_and_add(&dev->kobj, &ktype_cpuidle, &sysdev->kobj, "cpuidle"); if (!error) kobject_uevent(&dev->kobj, KOBJ_ADD); return error; } /** * cpuidle_remove_sysfs - deletes a sysfs instance on the target device * @sysdev: the target device */ void cpuidle_remove_sysfs(struct sys_device *sysdev) { int cpu = sysdev->id; struct cpuidle_device *dev; dev = per_cpu(cpuidle_devices, cpu); kobject_put(&dev->kobj); }