1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Authors:
4 * Branden Bonaby <brandonbonaby94@gmail.com>
5 */
6
7#include <linux/hyperv.h>
8#include <linux/debugfs.h>
9#include <linux/delay.h>
10#include <linux/err.h>
11
12#include "hyperv_vmbus.h"
13
14static struct dentry *hv_debug_root;
15
16static int hv_debugfs_delay_get(void *data, u64 *val)
17{
18 *val = *(u32 *)data;
19 return 0;
20}
21
22static int hv_debugfs_delay_set(void *data, u64 val)
23{
24 if (val > 1000)
25 return -EINVAL;
26 *(u32 *)data = val;
27 return 0;
28}
29
30DEFINE_DEBUGFS_ATTRIBUTE(hv_debugfs_delay_fops, hv_debugfs_delay_get,
31 hv_debugfs_delay_set, "%llu\n");
32
33static int hv_debugfs_state_get(void *data, u64 *val)
34{
35 *val = *(bool *)data;
36 return 0;
37}
38
39static int hv_debugfs_state_set(void *data, u64 val)
40{
41 if (val == 1)
42 *(bool *)data = true;
43 else if (val == 0)
44 *(bool *)data = false;
45 else
46 return -EINVAL;
47 return 0;
48}
49
50DEFINE_DEBUGFS_ATTRIBUTE(hv_debugfs_state_fops, hv_debugfs_state_get,
51 hv_debugfs_state_set, "%llu\n");
52
53/* Setup delay files to store test values */
54static int hv_debug_delay_files(struct hv_device *dev, struct dentry *root)
55{
56 struct vmbus_channel *channel = dev->channel;
57 char *buffer = "fuzz_test_buffer_interrupt_delay";
58 char *message = "fuzz_test_message_delay";
59 int *buffer_val = &channel->fuzz_testing_interrupt_delay;
60 int *message_val = &channel->fuzz_testing_message_delay;
61 struct dentry *buffer_file, *message_file;
62
63 buffer_file = debugfs_create_file(name: buffer, mode: 0644, parent: root,
64 data: buffer_val,
65 fops: &hv_debugfs_delay_fops);
66 if (IS_ERR(ptr: buffer_file)) {
67 pr_debug("debugfs_hyperv: file %s not created\n", buffer);
68 return PTR_ERR(ptr: buffer_file);
69 }
70
71 message_file = debugfs_create_file(name: message, mode: 0644, parent: root,
72 data: message_val,
73 fops: &hv_debugfs_delay_fops);
74 if (IS_ERR(ptr: message_file)) {
75 pr_debug("debugfs_hyperv: file %s not created\n", message);
76 return PTR_ERR(ptr: message_file);
77 }
78
79 return 0;
80}
81
82/* Setup test state value for vmbus device */
83static int hv_debug_set_test_state(struct hv_device *dev, struct dentry *root)
84{
85 struct vmbus_channel *channel = dev->channel;
86 bool *state = &channel->fuzz_testing_state;
87 char *status = "fuzz_test_state";
88 struct dentry *test_state;
89
90 test_state = debugfs_create_file(name: status, mode: 0644, parent: root,
91 data: state,
92 fops: &hv_debugfs_state_fops);
93 if (IS_ERR(ptr: test_state)) {
94 pr_debug("debugfs_hyperv: file %s not created\n", status);
95 return PTR_ERR(ptr: test_state);
96 }
97
98 return 0;
99}
100
101/* Bind hv device to a dentry for debugfs */
102static void hv_debug_set_dir_dentry(struct hv_device *dev, struct dentry *root)
103{
104 if (hv_debug_root)
105 dev->debug_dir = root;
106}
107
108/* Create all test dentry's and names for fuzz testing */
109int hv_debug_add_dev_dir(struct hv_device *dev)
110{
111 const char *device = dev_name(dev: &dev->device);
112 char *delay_name = "delay";
113 struct dentry *delay, *dev_root;
114 int ret;
115
116 if (!IS_ERR(ptr: hv_debug_root)) {
117 dev_root = debugfs_create_dir(name: device, parent: hv_debug_root);
118 if (IS_ERR(ptr: dev_root)) {
119 pr_debug("debugfs_hyperv: hyperv/%s/ not created\n",
120 device);
121 return PTR_ERR(ptr: dev_root);
122 }
123 hv_debug_set_test_state(dev, root: dev_root);
124 hv_debug_set_dir_dentry(dev, root: dev_root);
125 delay = debugfs_create_dir(name: delay_name, parent: dev_root);
126
127 if (IS_ERR(ptr: delay)) {
128 pr_debug("debugfs_hyperv: hyperv/%s/%s/ not created\n",
129 device, delay_name);
130 return PTR_ERR(ptr: delay);
131 }
132 ret = hv_debug_delay_files(dev, root: delay);
133
134 return ret;
135 }
136 pr_debug("debugfs_hyperv: hyperv/ not in root debugfs path\n");
137 return PTR_ERR(ptr: hv_debug_root);
138}
139
140/* Remove dentry associated with released hv device */
141void hv_debug_rm_dev_dir(struct hv_device *dev)
142{
143 if (!IS_ERR(ptr: hv_debug_root))
144 debugfs_remove_recursive(dentry: dev->debug_dir);
145}
146
147/* Remove all dentrys associated with vmbus testing */
148void hv_debug_rm_all_dir(void)
149{
150 debugfs_remove_recursive(dentry: hv_debug_root);
151}
152
153/* Delay buffer/message reads on a vmbus channel */
154void hv_debug_delay_test(struct vmbus_channel *channel, enum delay delay_type)
155{
156 struct vmbus_channel *test_channel = channel->primary_channel ?
157 channel->primary_channel :
158 channel;
159 bool state = test_channel->fuzz_testing_state;
160
161 if (state) {
162 if (delay_type == 0)
163 udelay(test_channel->fuzz_testing_interrupt_delay);
164 else
165 udelay(test_channel->fuzz_testing_message_delay);
166 }
167}
168
169/* Initialize top dentry for vmbus testing */
170int hv_debug_init(void)
171{
172 hv_debug_root = debugfs_create_dir(name: "hyperv", NULL);
173 if (IS_ERR(ptr: hv_debug_root)) {
174 pr_debug("debugfs_hyperv: hyperv/ not created\n");
175 return PTR_ERR(ptr: hv_debug_root);
176 }
177 return 0;
178}
179

source code of linux/drivers/hv/hv_debugfs.c