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(buffer, 0644, root,
64					  buffer_val,
65					  &hv_debugfs_delay_fops);
66	if (IS_ERR(buffer_file)) {
67		pr_debug("debugfs_hyperv: file %s not created\n", buffer);
68		return PTR_ERR(buffer_file);
69	}
70
71	message_file = debugfs_create_file(message, 0644, root,
72					   message_val,
73					   &hv_debugfs_delay_fops);
74	if (IS_ERR(message_file)) {
75		pr_debug("debugfs_hyperv: file %s not created\n", message);
76		return PTR_ERR(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(status, 0644, root,
91					 state,
92					 &hv_debugfs_state_fops);
93	if (IS_ERR(test_state)) {
94		pr_debug("debugfs_hyperv: file %s not created\n", status);
95		return PTR_ERR(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->device);
112	char *delay_name = "delay";
113	struct dentry *delay, *dev_root;
114	int ret;
115
116	if (!IS_ERR(hv_debug_root)) {
117		dev_root = debugfs_create_dir(device, hv_debug_root);
118		if (IS_ERR(dev_root)) {
119			pr_debug("debugfs_hyperv: hyperv/%s/ not created\n",
120				 device);
121			return PTR_ERR(dev_root);
122		}
123		hv_debug_set_test_state(dev, dev_root);
124		hv_debug_set_dir_dentry(dev, dev_root);
125		delay = debugfs_create_dir(delay_name, dev_root);
126
127		if (IS_ERR(delay)) {
128			pr_debug("debugfs_hyperv: hyperv/%s/%s/ not created\n",
129				 device, delay_name);
130			return PTR_ERR(delay);
131		}
132		ret = hv_debug_delay_files(dev, delay);
133
134		return ret;
135	}
136	pr_debug("debugfs_hyperv: hyperv/ not in root debugfs path\n");
137	return PTR_ERR(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(hv_debug_root))
144		debugfs_remove_recursive(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(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("hyperv", NULL);
173	if (IS_ERR(hv_debug_root)) {
174		pr_debug("debugfs_hyperv: hyperv/ not created\n");
175		return PTR_ERR(hv_debug_root);
176	}
177	return 0;
178}
179