xref: /linux/drivers/hv/hv_debugfs.c (revision ead5d1f4d877e92c051e1a1ade623d0d30e71619)
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 
14 static struct dentry *hv_debug_root;
15 
hv_debugfs_delay_get(void * data,u64 * val)16 static int hv_debugfs_delay_get(void *data, u64 *val)
17 {
18 	*val = *(u32 *)data;
19 	return 0;
20 }
21 
hv_debugfs_delay_set(void * data,u64 val)22 static 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 
30 DEFINE_DEBUGFS_ATTRIBUTE(hv_debugfs_delay_fops, hv_debugfs_delay_get,
31 			 hv_debugfs_delay_set, "%llu\n");
32 
hv_debugfs_state_get(void * data,u64 * val)33 static int hv_debugfs_state_get(void *data, u64 *val)
34 {
35 	*val = *(bool *)data;
36 	return 0;
37 }
38 
hv_debugfs_state_set(void * data,u64 val)39 static 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 
50 DEFINE_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 */
hv_debug_delay_files(struct hv_device * dev,struct dentry * root)54 static 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 */
hv_debug_set_test_state(struct hv_device * dev,struct dentry * root)83 static 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 */
hv_debug_set_dir_dentry(struct hv_device * dev,struct dentry * root)102 static 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 */
hv_debug_add_dev_dir(struct hv_device * dev)109 int 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 */
hv_debug_rm_dev_dir(struct hv_device * dev)141 void 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 */
hv_debug_rm_all_dir(void)148 void 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 */
hv_debug_delay_test(struct vmbus_channel * channel,enum delay delay_type)154 void 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 */
hv_debug_init(void)170 int 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