1 // SPDX-License-Identifier: GPL-2.0
3 * Hypervisor filesystem for Linux on s390 - debugfs interface
5 * Copyright IBM Corp. 2010
6 * Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com>
9 #include <linux/slab.h>
12 static struct dentry *dbfs_dir;
14 static struct hypfs_dbfs_data *hypfs_dbfs_data_alloc(struct hypfs_dbfs_file *f)
16 struct hypfs_dbfs_data *data;
18 data = kmalloc(sizeof(*data), GFP_KERNEL);
25 static void hypfs_dbfs_data_free(struct hypfs_dbfs_data *data)
27 data->dbfs_file->data_free(data->buf_free_ptr);
31 static ssize_t dbfs_read(struct file *file, char __user *buf,
32 size_t size, loff_t *ppos)
34 struct hypfs_dbfs_data *data;
35 struct hypfs_dbfs_file *df;
41 df = file_inode(file)->i_private;
42 mutex_lock(&df->lock);
43 data = hypfs_dbfs_data_alloc(df);
45 mutex_unlock(&df->lock);
48 rc = df->data_create(&data->buf, &data->buf_free_ptr, &data->size);
50 mutex_unlock(&df->lock);
54 mutex_unlock(&df->lock);
56 rc = simple_read_from_buffer(buf, size, ppos, data->buf, data->size);
57 hypfs_dbfs_data_free(data);
61 static long dbfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
63 struct hypfs_dbfs_file *df = file_inode(file)->i_private;
66 mutex_lock(&df->lock);
67 if (df->unlocked_ioctl)
68 rc = df->unlocked_ioctl(file, cmd, arg);
71 mutex_unlock(&df->lock);
75 static const struct file_operations dbfs_ops = {
78 .unlocked_ioctl = dbfs_ioctl,
81 int hypfs_dbfs_create_file(struct hypfs_dbfs_file *df)
83 df->dentry = debugfs_create_file(df->name, 0400, dbfs_dir, df,
85 if (IS_ERR(df->dentry))
86 return PTR_ERR(df->dentry);
87 mutex_init(&df->lock);
91 void hypfs_dbfs_remove_file(struct hypfs_dbfs_file *df)
93 debugfs_remove(df->dentry);
96 int hypfs_dbfs_init(void)
98 dbfs_dir = debugfs_create_dir("s390_hypfs", NULL);
99 return PTR_ERR_OR_ZERO(dbfs_dir);
102 void hypfs_dbfs_exit(void)
104 debugfs_remove(dbfs_dir);