// SPDX-License-Identifier: GPL-2.0-or-later #include <linux/virtio.h>#include <linux/virtio_config.h>#include <linux/debugfs.h> static struct dentry *virtio_debugfs_dir; static int virtio_debug_device_features_show(struct seq_file *s, void *data){	struct virtio_device *dev = s->private;	u64 device_features;	unsigned int i; 	device_features = dev->config->get_features(dev);	for (i = 0; i < BITS_PER_LONG_LONG; i++) {		if (device_features & (1ULL << i))			seq_printf(s, "%u\n", i);	}	return 0;}DEFINE_SHOW_ATTRIBUTE(virtio_debug_device_features); static int virtio_debug_filter_features_show(struct seq_file *s, void *data){	struct virtio_device *dev = s->private;	unsigned int i; 	for (i = 0; i < BITS_PER_LONG_LONG; i++) {		if (dev->debugfs_filter_features & (1ULL << i))			seq_printf(s, "%u\n", i);	}	return 0;}DEFINE_SHOW_ATTRIBUTE(virtio_debug_filter_features); static int virtio_debug_filter_features_clear(void *data, u64 val){	struct virtio_device *dev = data; 	if (val == 1)		dev->debugfs_filter_features = 0;	return 0;} DEFINE_DEBUGFS_ATTRIBUTE(virtio_debug_filter_features_clear_fops, NULL,			 virtio_debug_filter_features_clear, "%llu\n"); static int virtio_debug_filter_feature_add(void *data, u64 val){	struct virtio_device *dev = data; 	if (val >= BITS_PER_LONG_LONG)		return -EINVAL;	dev->debugfs_filter_features |= BIT_ULL_MASK(val);	return 0;} DEFINE_DEBUGFS_ATTRIBUTE(virtio_debug_filter_feature_add_fops, NULL,			 virtio_debug_filter_feature_add, "%llu\n"); static int virtio_debug_filter_feature_del(void *data, u64 val){	struct virtio_device *dev = data; 	if (val >= BITS_PER_LONG_LONG)		return -EINVAL;	dev->debugfs_filter_features &= ~BIT_ULL_MASK(val);	return 0;} DEFINE_DEBUGFS_ATTRIBUTE(virtio_debug_filter_feature_del_fops, NULL,			 virtio_debug_filter_feature_del, "%llu\n"); void virtio_debug_device_init(struct virtio_device *dev){	dev->debugfs_dir = debugfs_create_dir(dev_name(&dev->dev),					      virtio_debugfs_dir);	debugfs_create_file("device_features", 0400, dev->debugfs_dir, dev,			    &virtio_debug_device_features_fops);	debugfs_create_file("filter_features", 0400, dev->debugfs_dir, dev,			    &virtio_debug_filter_features_fops);	debugfs_create_file("filter_features_clear", 0200, dev->debugfs_dir, dev,			    &virtio_debug_filter_features_clear_fops);	debugfs_create_file("filter_feature_add", 0200, dev->debugfs_dir, dev,			    &virtio_debug_filter_feature_add_fops);	debugfs_create_file("filter_feature_del", 0200, dev->debugfs_dir, dev,			    &virtio_debug_filter_feature_del_fops);}EXPORT_SYMBOL_GPL(virtio_debug_device_init); void virtio_debug_device_filter_features(struct virtio_device *dev){	dev->features &= ~dev->debugfs_filter_features;}EXPORT_SYMBOL_GPL(virtio_debug_device_filter_features); void virtio_debug_device_exit(struct virtio_device *dev){	debugfs_remove_recursive(dev->debugfs_dir);}EXPORT_SYMBOL_GPL(virtio_debug_device_exit); void virtio_debug_init(void){	virtio_debugfs_dir = debugfs_create_dir("virtio", NULL);}EXPORT_SYMBOL_GPL(virtio_debug_init); void virtio_debug_exit(void){	debugfs_remove_recursive(virtio_debugfs_dir);}EXPORT_SYMBOL_GPL(virtio_debug_exit);