drivers/virtio/virtio_debug.c

   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
   7 static struct dentry *virtio_debugfs_dir;
   8
   9 static 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 }
  22 DEFINE_SHOW_ATTRIBUTE(virtio_debug_device_features);
  23
  24 static 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 }
  35 DEFINE_SHOW_ATTRIBUTE(virtio_debug_filter_features);
  36
  37 static 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
  46 DEFINE_DEBUGFS_ATTRIBUTE(virtio_debug_filter_features_clear_fops, NULL,
  47                          virtio_debug_filter_features_clear, "%llu\n");
  48
  49 static 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
  59 DEFINE_DEBUGFS_ATTRIBUTE(virtio_debug_filter_feature_add_fops, NULL,
  60                          virtio_debug_filter_feature_add, "%llu\n");
  61
  62 static 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
  72 DEFINE_DEBUGFS_ATTRIBUTE(virtio_debug_filter_feature_del_fops, NULL,
  73                          virtio_debug_filter_feature_del, "%llu\n");
  74
  75 void 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 }
  90 EXPORT_SYMBOL_GPL(virtio_debug_device_init);
  91
  92 void virtio_debug_device_filter_features(struct virtio_device *dev)
  93 {
  94         dev->features &= ~dev->debugfs_filter_features;
  95 }
  96 EXPORT_SYMBOL_GPL(virtio_debug_device_filter_features);
  97
  98 void virtio_debug_device_exit(struct virtio_device *dev)
  99 {
 100         debugfs_remove_recursive(dev->debugfs_dir);
 101 }
 102 EXPORT_SYMBOL_GPL(virtio_debug_device_exit);
 103
 104 void virtio_debug_init(void)
 105 {
 106         virtio_debugfs_dir = debugfs_create_dir("virtio", NULL);
 107 }
 108 EXPORT_SYMBOL_GPL(virtio_debug_init);
 109
 110 void virtio_debug_exit(void)
 111 {
 112         debugfs_remove_recursive(virtio_debugfs_dir);
 113 }
 114 EXPORT_SYMBOL_GPL(virtio_debug_exit);