1 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
2 /*
3  * Copyright (c) 2014 Raspberry Pi (Trading) Ltd. All rights reserved.
4  * Copyright (c) 2010-2012 Broadcom. All rights reserved.
5  */
6 
7 #include <linux/debugfs.h>
8 #include "vchiq_core.h"
9 #include "vchiq_arm.h"
10 #include "vchiq_debugfs.h"
11 
12 #ifdef CONFIG_DEBUG_FS
13 
14 /****************************************************************************
15 *
16 *   log category entries
17 *
18 ***************************************************************************/
19 #define DEBUGFS_WRITE_BUF_SIZE 256
20 
21 #define VCHIQ_LOG_ERROR_STR   "error"
22 #define VCHIQ_LOG_WARNING_STR "warning"
23 #define VCHIQ_LOG_INFO_STR    "info"
24 #define VCHIQ_LOG_TRACE_STR   "trace"
25 
26 /* Global 'vchiq' debugfs and clients entry used by all instances */
27 static struct dentry *vchiq_dbg_dir;
28 static struct dentry *vchiq_dbg_clients;
29 
30 /* Log category debugfs entries */
31 struct vchiq_debugfs_log_entry {
32 	const char *name;
33 	void *plevel;
34 };
35 
36 static struct vchiq_debugfs_log_entry vchiq_debugfs_log_entries[] = {
37 	{ "core", &vchiq_core_log_level },
38 	{ "msg",  &vchiq_core_msg_log_level },
39 	{ "sync", &vchiq_sync_log_level },
40 	{ "susp", &vchiq_susp_log_level },
41 	{ "arm",  &vchiq_arm_log_level },
42 };
43 static int n_log_entries = ARRAY_SIZE(vchiq_debugfs_log_entries);
44 
45 static int debugfs_log_show(struct seq_file *f, void *offset)
46 {
47 	int *levp = f->private;
48 	char *log_value = NULL;
49 
50 	switch (*levp) {
51 	case VCHIQ_LOG_ERROR:
52 		log_value = VCHIQ_LOG_ERROR_STR;
53 		break;
54 	case VCHIQ_LOG_WARNING:
55 		log_value = VCHIQ_LOG_WARNING_STR;
56 		break;
57 	case VCHIQ_LOG_INFO:
58 		log_value = VCHIQ_LOG_INFO_STR;
59 		break;
60 	case VCHIQ_LOG_TRACE:
61 		log_value = VCHIQ_LOG_TRACE_STR;
62 		break;
63 	default:
64 		break;
65 	}
66 
67 	seq_printf(f, "%s\n", log_value ? log_value : "(null)");
68 
69 	return 0;
70 }
71 
72 static int debugfs_log_open(struct inode *inode, struct file *file)
73 {
74 	return single_open(file, debugfs_log_show, inode->i_private);
75 }
76 
77 static ssize_t debugfs_log_write(struct file *file,
78 	const char __user *buffer,
79 	size_t count, loff_t *ppos)
80 {
81 	struct seq_file *f = (struct seq_file *)file->private_data;
82 	int *levp = f->private;
83 	char kbuf[DEBUGFS_WRITE_BUF_SIZE + 1];
84 
85 	memset(kbuf, 0, DEBUGFS_WRITE_BUF_SIZE + 1);
86 	if (count >= DEBUGFS_WRITE_BUF_SIZE)
87 		count = DEBUGFS_WRITE_BUF_SIZE;
88 
89 	if (copy_from_user(kbuf, buffer, count))
90 		return -EFAULT;
91 	kbuf[count - 1] = 0;
92 
93 	if (strncmp("error", kbuf, strlen("error")) == 0)
94 		*levp = VCHIQ_LOG_ERROR;
95 	else if (strncmp("warning", kbuf, strlen("warning")) == 0)
96 		*levp = VCHIQ_LOG_WARNING;
97 	else if (strncmp("info", kbuf, strlen("info")) == 0)
98 		*levp = VCHIQ_LOG_INFO;
99 	else if (strncmp("trace", kbuf, strlen("trace")) == 0)
100 		*levp = VCHIQ_LOG_TRACE;
101 	else
102 		*levp = VCHIQ_LOG_DEFAULT;
103 
104 	*ppos += count;
105 
106 	return count;
107 }
108 
109 static const struct file_operations debugfs_log_fops = {
110 	.owner		= THIS_MODULE,
111 	.open		= debugfs_log_open,
112 	.write		= debugfs_log_write,
113 	.read		= seq_read,
114 	.llseek		= seq_lseek,
115 	.release	= single_release,
116 };
117 
118 static int debugfs_usecount_show(struct seq_file *f, void *offset)
119 {
120 	struct vchiq_instance *instance = f->private;
121 	int use_count;
122 
123 	use_count = vchiq_instance_get_use_count(instance);
124 	seq_printf(f, "%d\n", use_count);
125 
126 	return 0;
127 }
128 DEFINE_SHOW_ATTRIBUTE(debugfs_usecount);
129 
130 static int debugfs_trace_show(struct seq_file *f, void *offset)
131 {
132 	struct vchiq_instance *instance = f->private;
133 	int trace;
134 
135 	trace = vchiq_instance_get_trace(instance);
136 	seq_printf(f, "%s\n", trace ? "Y" : "N");
137 
138 	return 0;
139 }
140 
141 static int debugfs_trace_open(struct inode *inode, struct file *file)
142 {
143 	return single_open(file, debugfs_trace_show, inode->i_private);
144 }
145 
146 static ssize_t debugfs_trace_write(struct file *file,
147 	const char __user *buffer,
148 	size_t count, loff_t *ppos)
149 {
150 	struct seq_file *f = (struct seq_file *)file->private_data;
151 	struct vchiq_instance *instance = f->private;
152 	char firstchar;
153 
154 	if (copy_from_user(&firstchar, buffer, 1))
155 		return -EFAULT;
156 
157 	switch (firstchar) {
158 	case 'Y':
159 	case 'y':
160 	case '1':
161 		vchiq_instance_set_trace(instance, 1);
162 		break;
163 	case 'N':
164 	case 'n':
165 	case '0':
166 		vchiq_instance_set_trace(instance, 0);
167 		break;
168 	default:
169 		break;
170 	}
171 
172 	*ppos += count;
173 
174 	return count;
175 }
176 
177 static const struct file_operations debugfs_trace_fops = {
178 	.owner		= THIS_MODULE,
179 	.open		= debugfs_trace_open,
180 	.write		= debugfs_trace_write,
181 	.read		= seq_read,
182 	.llseek		= seq_lseek,
183 	.release	= single_release,
184 };
185 
186 /* add an instance (process) to the debugfs entries */
187 void vchiq_debugfs_add_instance(struct vchiq_instance *instance)
188 {
189 	char pidstr[16];
190 	struct dentry *top;
191 
192 	snprintf(pidstr, sizeof(pidstr), "%d",
193 		 vchiq_instance_get_pid(instance));
194 
195 	top = debugfs_create_dir(pidstr, vchiq_dbg_clients);
196 
197 	debugfs_create_file("use_count", 0444, top, instance,
198 			    &debugfs_usecount_fops);
199 	debugfs_create_file("trace", 0644, top, instance, &debugfs_trace_fops);
200 
201 	vchiq_instance_get_debugfs_node(instance)->dentry = top;
202 }
203 
204 void vchiq_debugfs_remove_instance(struct vchiq_instance *instance)
205 {
206 	struct vchiq_debugfs_node *node =
207 				vchiq_instance_get_debugfs_node(instance);
208 
209 	debugfs_remove_recursive(node->dentry);
210 }
211 
212 void vchiq_debugfs_init(void)
213 {
214 	struct dentry *dir;
215 	int i;
216 
217 	vchiq_dbg_dir = debugfs_create_dir("vchiq", NULL);
218 	vchiq_dbg_clients = debugfs_create_dir("clients", vchiq_dbg_dir);
219 
220 	/* create an entry under <debugfs>/vchiq/log for each log category */
221 	dir = debugfs_create_dir("log", vchiq_dbg_dir);
222 
223 	for (i = 0; i < n_log_entries; i++)
224 		debugfs_create_file(vchiq_debugfs_log_entries[i].name, 0644,
225 				    dir, vchiq_debugfs_log_entries[i].plevel,
226 				    &debugfs_log_fops);
227 }
228 
229 /* remove all the debugfs entries */
230 void vchiq_debugfs_deinit(void)
231 {
232 	debugfs_remove_recursive(vchiq_dbg_dir);
233 }
234 
235 #else /* CONFIG_DEBUG_FS */
236 
237 void vchiq_debugfs_init(void)
238 {
239 }
240 
241 void vchiq_debugfs_deinit(void)
242 {
243 }
244 
245 void vchiq_debugfs_add_instance(struct vchiq_instance *instance)
246 {
247 }
248 
249 void vchiq_debugfs_remove_instance(struct vchiq_instance *instance)
250 {
251 }
252 
253 #endif /* CONFIG_DEBUG_FS */
254