1// SPDX-License-Identifier: GPL-2.0-or-later
  2
  3#include <linux/virtio.h>
  4#include <linux/virtio_config.h>
  5#include <linux/debugfs.h>
  6
  7static struct dentry *virtio_debugfs_dir;
  8
  9static int virtio_debug_device_features_show(struct seq_file *s, void *data)
 10{
 11	struct virtio_device *dev = s->private;
 12	u64 device_features;
 13	unsigned int i;
 14
 15	device_features = dev->config->get_features(dev);
 16	for (i = 0; i < BITS_PER_LONG_LONG; i++) {
 17		if (device_features & (1ULL << i))
 18			seq_printf(s, "%u\n", i);
 19	}
 20	return 0;
 21}
 22DEFINE_SHOW_ATTRIBUTE(virtio_debug_device_features);
 23
 24static int virtio_debug_filter_features_show(struct seq_file *s, void *data)
 25{
 26	struct virtio_device *dev = s->private;
 27	unsigned int i;
 28
 29	for (i = 0; i < BITS_PER_LONG_LONG; i++) {
 30		if (dev->debugfs_filter_features & (1ULL << i))
 31			seq_printf(s, "%u\n", i);
 32	}
 33	return 0;
 34}
 35DEFINE_SHOW_ATTRIBUTE(virtio_debug_filter_features);
 36
 37static int virtio_debug_filter_features_clear(void *data, u64 val)
 38{
 39	struct virtio_device *dev = data;
 40
 41	if (val == 1)
 42		dev->debugfs_filter_features = 0;
 43	return 0;
 44}
 45
 46DEFINE_DEBUGFS_ATTRIBUTE(virtio_debug_filter_features_clear_fops, NULL,
 47			 virtio_debug_filter_features_clear, "%llu\n");
 48
 49static int virtio_debug_filter_feature_add(void *data, u64 val)
 50{
 51	struct virtio_device *dev = data;
 52
 53	if (val >= BITS_PER_LONG_LONG)
 54		return -EINVAL;
 55	dev->debugfs_filter_features |= BIT_ULL_MASK(val);
 56	return 0;
 57}
 58
 59DEFINE_DEBUGFS_ATTRIBUTE(virtio_debug_filter_feature_add_fops, NULL,
 60			 virtio_debug_filter_feature_add, "%llu\n");
 61
 62static int virtio_debug_filter_feature_del(void *data, u64 val)
 63{
 64	struct virtio_device *dev = data;
 65
 66	if (val >= BITS_PER_LONG_LONG)
 67		return -EINVAL;
 68	dev->debugfs_filter_features &= ~BIT_ULL_MASK(val);
 69	return 0;
 70}
 71
 72DEFINE_DEBUGFS_ATTRIBUTE(virtio_debug_filter_feature_del_fops, NULL,
 73			 virtio_debug_filter_feature_del, "%llu\n");
 74
 75void virtio_debug_device_init(struct virtio_device *dev)
 76{
 77	dev->debugfs_dir = debugfs_create_dir(dev_name(&dev->dev),
 78					      virtio_debugfs_dir);
 79	debugfs_create_file("device_features", 0400, dev->debugfs_dir, dev,
 80			    &virtio_debug_device_features_fops);
 81	debugfs_create_file("filter_features", 0400, dev->debugfs_dir, dev,
 82			    &virtio_debug_filter_features_fops);
 83	debugfs_create_file("filter_features_clear", 0200, dev->debugfs_dir, dev,
 84			    &virtio_debug_filter_features_clear_fops);
 85	debugfs_create_file("filter_feature_add", 0200, dev->debugfs_dir, dev,
 86			    &virtio_debug_filter_feature_add_fops);
 87	debugfs_create_file("filter_feature_del", 0200, dev->debugfs_dir, dev,
 88			    &virtio_debug_filter_feature_del_fops);
 89}
 90EXPORT_SYMBOL_GPL(virtio_debug_device_init);
 91
 92void virtio_debug_device_filter_features(struct virtio_device *dev)
 93{
 94	dev->features &= ~dev->debugfs_filter_features;
 95}
 96EXPORT_SYMBOL_GPL(virtio_debug_device_filter_features);
 97
 98void virtio_debug_device_exit(struct virtio_device *dev)
 99{
100	debugfs_remove_recursive(dev->debugfs_dir);
101}
102EXPORT_SYMBOL_GPL(virtio_debug_device_exit);
103
104void virtio_debug_init(void)
105{
106	virtio_debugfs_dir = debugfs_create_dir("virtio", NULL);
107}
108EXPORT_SYMBOL_GPL(virtio_debug_init);
109
110void virtio_debug_exit(void)
111{
112	debugfs_remove_recursive(virtio_debugfs_dir);
113}
114EXPORT_SYMBOL_GPL(virtio_debug_exit);