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  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}
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