1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Hypervisor filesystem for Linux on s390 - debugfs interface |
4 | * |
5 | * Copyright IBM Corp. 2010 |
6 | * Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com> |
7 | */ |
8 | |
9 | #include <linux/slab.h> |
10 | #include "hypfs.h" |
11 | |
12 | static struct dentry *dbfs_dir; |
13 | |
14 | static struct hypfs_dbfs_data *hypfs_dbfs_data_alloc(struct hypfs_dbfs_file *f) |
15 | { |
16 | struct hypfs_dbfs_data *data; |
17 | |
18 | data = kmalloc(size: sizeof(*data), GFP_KERNEL); |
19 | if (!data) |
20 | return NULL; |
21 | data->dbfs_file = f; |
22 | return data; |
23 | } |
24 | |
25 | static void hypfs_dbfs_data_free(struct hypfs_dbfs_data *data) |
26 | { |
27 | data->dbfs_file->data_free(data->buf_free_ptr); |
28 | kfree(objp: data); |
29 | } |
30 | |
31 | static ssize_t dbfs_read(struct file *file, char __user *buf, |
32 | size_t size, loff_t *ppos) |
33 | { |
34 | struct hypfs_dbfs_data *data; |
35 | struct hypfs_dbfs_file *df; |
36 | ssize_t rc; |
37 | |
38 | if (*ppos != 0) |
39 | return 0; |
40 | |
41 | df = file_inode(f: file)->i_private; |
42 | mutex_lock(&df->lock); |
43 | data = hypfs_dbfs_data_alloc(f: df); |
44 | if (!data) { |
45 | mutex_unlock(lock: &df->lock); |
46 | return -ENOMEM; |
47 | } |
48 | rc = df->data_create(&data->buf, &data->buf_free_ptr, &data->size); |
49 | if (rc) { |
50 | mutex_unlock(lock: &df->lock); |
51 | kfree(objp: data); |
52 | return rc; |
53 | } |
54 | mutex_unlock(lock: &df->lock); |
55 | |
56 | rc = simple_read_from_buffer(to: buf, count: size, ppos, from: data->buf, available: data->size); |
57 | hypfs_dbfs_data_free(data); |
58 | return rc; |
59 | } |
60 | |
61 | static long dbfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
62 | { |
63 | struct hypfs_dbfs_file *df = file_inode(f: file)->i_private; |
64 | long rc; |
65 | |
66 | mutex_lock(&df->lock); |
67 | if (df->unlocked_ioctl) |
68 | rc = df->unlocked_ioctl(file, cmd, arg); |
69 | else |
70 | rc = -ENOTTY; |
71 | mutex_unlock(lock: &df->lock); |
72 | return rc; |
73 | } |
74 | |
75 | static const struct file_operations dbfs_ops = { |
76 | .read = dbfs_read, |
77 | .llseek = no_llseek, |
78 | .unlocked_ioctl = dbfs_ioctl, |
79 | }; |
80 | |
81 | void hypfs_dbfs_create_file(struct hypfs_dbfs_file *df) |
82 | { |
83 | df->dentry = debugfs_create_file(name: df->name, mode: 0400, parent: dbfs_dir, data: df, |
84 | fops: &dbfs_ops); |
85 | mutex_init(&df->lock); |
86 | } |
87 | |
88 | void hypfs_dbfs_remove_file(struct hypfs_dbfs_file *df) |
89 | { |
90 | debugfs_remove(dentry: df->dentry); |
91 | } |
92 | |
93 | static int __init hypfs_dbfs_init(void) |
94 | { |
95 | int rc = -ENODATA; |
96 | |
97 | dbfs_dir = debugfs_create_dir(name: "s390_hypfs" , NULL); |
98 | if (hypfs_diag_init()) |
99 | goto fail_dbfs_exit; |
100 | if (hypfs_vm_init()) |
101 | goto fail_hypfs_diag_exit; |
102 | hypfs_sprp_init(); |
103 | if (hypfs_diag0c_init()) |
104 | goto fail_hypfs_sprp_exit; |
105 | rc = hypfs_fs_init(); |
106 | if (rc) |
107 | goto fail_hypfs_diag0c_exit; |
108 | return 0; |
109 | |
110 | fail_hypfs_diag0c_exit: |
111 | hypfs_diag0c_exit(); |
112 | fail_hypfs_sprp_exit: |
113 | hypfs_sprp_exit(); |
114 | hypfs_vm_exit(); |
115 | fail_hypfs_diag_exit: |
116 | hypfs_diag_exit(); |
117 | pr_err("Initialization of hypfs failed with rc=%i\n" , rc); |
118 | fail_dbfs_exit: |
119 | debugfs_remove(dentry: dbfs_dir); |
120 | return rc; |
121 | } |
122 | device_initcall(hypfs_dbfs_init) |
123 | |