diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c index 79d2e92e5c28..b4c91d57f3d4 100644 --- a/drivers/acpi/platform_profile.c +++ b/drivers/acpi/platform_profile.c @@ -8,15 +8,25 @@ #include #include #include +#include #include #include #include #define to_pprof_handler(d) (container_of(d, struct platform_profile_handler, dev)) +/* + * Protects profile_handlers membership and serializes profile operations + * against each other and handler removal. Never held across sysfs teardown, + * which can wait for callbacks that acquire this lock. + */ static DEFINE_MUTEX(profile_lock); +/* Serialize registration and sysfs updates without blocking sysfs callbacks. */ +static DEFINE_MUTEX(profile_registration_lock); +static LIST_HEAD(profile_handlers); struct platform_profile_handler { + struct list_head node; const char *name; struct device dev; int minor; @@ -44,6 +54,23 @@ static_assert(ARRAY_SIZE(profile_names) == PLATFORM_PROFILE_LAST); static DEFINE_IDA(platform_profile_ida); +static int profile_for_each_handler(void *data, + int (*fn)(struct device *dev, void *data)) +{ + struct platform_profile_handler *handler; + int ret; + + lockdep_assert_held(&profile_lock); + + list_for_each_entry(handler, &profile_handlers, node) { + ret = fn(&handler->dev, data); + if (ret) + return ret; + } + + return 0; +} + /** * _commmon_choices_show - Show the available profile choices * @choices: The available profile choices @@ -306,20 +333,18 @@ static ssize_t platform_profile_choices_show(struct kobject *kobj, int err; scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &profile_lock) { - err = class_for_each_device(&platform_profile_class, NULL, - &data, _aggregate_choices); + err = profile_for_each_handler(&data, _aggregate_choices); if (err) return err; if (data.count == 1) { - err = class_for_each_device(&platform_profile_class, NULL, - &data, _remove_hidden_choices); + err = profile_for_each_handler(&data, _remove_hidden_choices); if (err) return err; } } /* no profile handler registered any more */ - if (bitmap_empty(data.aggregate, PLATFORM_PROFILE_LAST)) + if (!data.count || bitmap_empty(data.aggregate, PLATFORM_PROFILE_LAST)) return -EINVAL; return _commmon_choices_show(data.aggregate, buf); @@ -384,8 +409,7 @@ static ssize_t platform_profile_show(struct kobject *kobj, int err; scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &profile_lock) { - err = class_for_each_device(&platform_profile_class, NULL, - &profile, _aggregate_profiles); + err = profile_for_each_handler(&profile, _aggregate_profiles); if (err) return err; } @@ -423,15 +447,13 @@ static ssize_t platform_profile_store(struct kobject *kobj, return -EINVAL; scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &profile_lock) { - ret = class_for_each_device(&platform_profile_class, NULL, - &data, _aggregate_choices); + ret = profile_for_each_handler(&data, _aggregate_choices); if (ret) return ret; - if (!test_bit(i, data.aggregate)) + if (!data.count || !test_bit(i, data.aggregate)) return -EOPNOTSUPP; - ret = class_for_each_device(&platform_profile_class, NULL, &i, - _store_and_notify); + ret = profile_for_each_handler(&i, _store_and_notify); if (ret) return ret; } @@ -450,22 +472,11 @@ static struct attribute *platform_profile_attrs[] = { NULL }; -static int profile_class_registered(struct device *dev, const void *data) -{ - return 1; -} - static umode_t profile_class_is_visible(struct kobject *kobj, struct attribute *attr, int idx) { - struct device *dev; + guard(mutex)(&profile_lock); - dev = class_find_device(&platform_profile_class, NULL, NULL, profile_class_registered); - if (!dev) - return 0; - - put_device(dev); - - return attr->mode; + return list_empty(&profile_handlers) ? 0 : attr->mode; } static const struct attribute_group platform_profile_group = { @@ -502,8 +513,7 @@ int platform_profile_cycle(void) int err; scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &profile_lock) { - err = class_for_each_device(&platform_profile_class, NULL, - &profile, _aggregate_profiles); + err = profile_for_each_handler(&profile, _aggregate_profiles); if (err) return err; @@ -512,8 +522,7 @@ int platform_profile_cycle(void) profile == PLATFORM_PROFILE_LAST) return -EINVAL; - err = class_for_each_device(&platform_profile_class, NULL, - &data, _aggregate_choices); + err = profile_for_each_handler(&data, _aggregate_choices); if (err) return err; @@ -525,8 +534,7 @@ int platform_profile_cycle(void) PLATFORM_PROFILE_LAST, profile + 1); - err = class_for_each_device(&platform_profile_class, NULL, &next, - _store_and_notify); + err = profile_for_each_handler(&next, _store_and_notify); if (err) return err; @@ -583,7 +591,7 @@ struct device *platform_profile_register(struct device *dev, const char *name, } } - guard(mutex)(&profile_lock); + guard(mutex)(&profile_registration_lock); /* create class interface for individual handler */ minor = ida_alloc(&platform_profile_ida, GFP_KERNEL); @@ -604,6 +612,8 @@ struct device *platform_profile_register(struct device *dev, const char *name, put_device(ppdev); goto cleanup_ida; } + scoped_guard(mutex, &profile_lock) + list_add_tail(&to_pprof_handler(ppdev)->node, &profile_handlers); sysfs_notify(acpi_kobj, NULL, "platform_profile"); @@ -614,6 +624,9 @@ struct device *platform_profile_register(struct device *dev, const char *name, return ppdev; cleanup_cur: + scoped_guard(mutex, &profile_lock) + list_del(&to_pprof_handler(ppdev)->node); + device_unregister(ppdev); cleanup_ida: @@ -636,7 +649,10 @@ void platform_profile_remove(struct device *dev) pprof = to_pprof_handler(dev); - guard(mutex)(&profile_lock); + guard(mutex)(&profile_registration_lock); + + scoped_guard(mutex, &profile_lock) + list_del(&pprof->node); ida_free(&platform_profile_ida, pprof->minor); device_unregister(&pprof->dev);