1 /**
2  * Copyright (c) 2014 Raspberry Pi (Trading) Ltd. All rights reserved.
3  * Copyright (c) 2010-2012 Broadcom. All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions, and the following disclaimer,
10  *    without modification.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. The names of the above-listed copyright holders may not be used
15  *    to endorse or promote products derived from this software without
16  *    specific prior written permission.
17  *
18  * ALTERNATIVELY, this software may be distributed under the terms of the
19  * GNU General Public License ("GPL") version 2, as published by the Free
20  * Software Foundation.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
23  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
24  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
25  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
26  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
27  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
28  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
29  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
30  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
31  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
32  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 
36 #include <linux/debugfs.h>
37 #include "vchiq_core.h"
38 #include "vchiq_arm.h"
39 #include "vchiq_debugfs.h"
40 
41 #ifdef CONFIG_DEBUG_FS
42 
43 /****************************************************************************
44 *
45 *   log category entries
46 *
47 ***************************************************************************/
48 #define DEBUGFS_WRITE_BUF_SIZE 256
49 
50 #define VCHIQ_LOG_ERROR_STR   "error"
51 #define VCHIQ_LOG_WARNING_STR "warning"
52 #define VCHIQ_LOG_INFO_STR    "info"
53 #define VCHIQ_LOG_TRACE_STR   "trace"
54 
55 
56 /* Top-level debug info */
57 struct vchiq_debugfs_info {
58 	/* Global 'vchiq' debugfs entry used by all instances */
59 	struct dentry *vchiq_cfg_dir;
60 
61 	/* one entry per client process */
62 	struct dentry *clients;
63 
64 	/* log categories */
65 	struct dentry *log_categories;
66 };
67 
68 static struct vchiq_debugfs_info debugfs_info;
69 
70 /* Log category debugfs entries */
71 struct vchiq_debugfs_log_entry {
72 	const char *name;
73 	int *plevel;
74 	struct dentry *dir;
75 };
76 
77 static struct vchiq_debugfs_log_entry vchiq_debugfs_log_entries[] = {
78 	{ "core", &vchiq_core_log_level },
79 	{ "msg",  &vchiq_core_msg_log_level },
80 	{ "sync", &vchiq_sync_log_level },
81 	{ "susp", &vchiq_susp_log_level },
82 	{ "arm",  &vchiq_arm_log_level },
83 };
84 static int n_log_entries = ARRAY_SIZE(vchiq_debugfs_log_entries);
85 
86 static struct dentry *vchiq_clients_top(void);
87 static struct dentry *vchiq_debugfs_top(void);
88 
89 static int debugfs_log_show(struct seq_file *f, void *offset)
90 {
91 	int *levp = f->private;
92 	char *log_value = NULL;
93 
94 	switch (*levp) {
95 	case VCHIQ_LOG_ERROR:
96 		log_value = VCHIQ_LOG_ERROR_STR;
97 		break;
98 	case VCHIQ_LOG_WARNING:
99 		log_value = VCHIQ_LOG_WARNING_STR;
100 		break;
101 	case VCHIQ_LOG_INFO:
102 		log_value = VCHIQ_LOG_INFO_STR;
103 		break;
104 	case VCHIQ_LOG_TRACE:
105 		log_value = VCHIQ_LOG_TRACE_STR;
106 		break;
107 	default:
108 		break;
109 	}
110 
111 	seq_printf(f, "%s\n", log_value ? log_value : "(null)");
112 
113 	return 0;
114 }
115 
116 static int debugfs_log_open(struct inode *inode, struct file *file)
117 {
118 	return single_open(file, debugfs_log_show, inode->i_private);
119 }
120 
121 static ssize_t debugfs_log_write(struct file *file,
122 	const char __user *buffer,
123 	size_t count, loff_t *ppos)
124 {
125 	struct seq_file *f = (struct seq_file *)file->private_data;
126 	int *levp = f->private;
127 	char kbuf[DEBUGFS_WRITE_BUF_SIZE + 1];
128 
129 	memset(kbuf, 0, DEBUGFS_WRITE_BUF_SIZE + 1);
130 	if (count >= DEBUGFS_WRITE_BUF_SIZE)
131 		count = DEBUGFS_WRITE_BUF_SIZE;
132 
133 	if (copy_from_user(kbuf, buffer, count) != 0)
134 		return -EFAULT;
135 	kbuf[count - 1] = 0;
136 
137 	if (strncmp("error", kbuf, strlen("error")) == 0)
138 		*levp = VCHIQ_LOG_ERROR;
139 	else if (strncmp("warning", kbuf, strlen("warning")) == 0)
140 		*levp = VCHIQ_LOG_WARNING;
141 	else if (strncmp("info", kbuf, strlen("info")) == 0)
142 		*levp = VCHIQ_LOG_INFO;
143 	else if (strncmp("trace", kbuf, strlen("trace")) == 0)
144 		*levp = VCHIQ_LOG_TRACE;
145 	else
146 		*levp = VCHIQ_LOG_DEFAULT;
147 
148 	*ppos += count;
149 
150 	return count;
151 }
152 
153 static const struct file_operations debugfs_log_fops = {
154 	.owner		= THIS_MODULE,
155 	.open		= debugfs_log_open,
156 	.write		= debugfs_log_write,
157 	.read		= seq_read,
158 	.llseek		= seq_lseek,
159 	.release	= single_release,
160 };
161 
162 /* create an entry under <debugfs>/vchiq/log for each log category */
163 static int vchiq_debugfs_create_log_entries(struct dentry *top)
164 {
165 	struct dentry *dir;
166 	size_t i;
167 	int ret = 0;
168 
169 	dir = debugfs_create_dir("log", vchiq_debugfs_top());
170 	if (!dir)
171 		return -ENOMEM;
172 	debugfs_info.log_categories = dir;
173 
174 	for (i = 0; i < n_log_entries; i++) {
175 		void *levp = (void *)vchiq_debugfs_log_entries[i].plevel;
176 
177 		dir = debugfs_create_file(vchiq_debugfs_log_entries[i].name,
178 					  0644,
179 					  debugfs_info.log_categories,
180 					  levp,
181 					  &debugfs_log_fops);
182 		if (!dir) {
183 			ret = -ENOMEM;
184 			break;
185 		}
186 
187 		vchiq_debugfs_log_entries[i].dir = dir;
188 	}
189 	return ret;
190 }
191 
192 static int debugfs_usecount_show(struct seq_file *f, void *offset)
193 {
194 	VCHIQ_INSTANCE_T instance = f->private;
195 	int use_count;
196 
197 	use_count = vchiq_instance_get_use_count(instance);
198 	seq_printf(f, "%d\n", use_count);
199 
200 	return 0;
201 }
202 
203 static int debugfs_usecount_open(struct inode *inode, struct file *file)
204 {
205 	return single_open(file, debugfs_usecount_show, inode->i_private);
206 }
207 
208 static const struct file_operations debugfs_usecount_fops = {
209 	.owner		= THIS_MODULE,
210 	.open		= debugfs_usecount_open,
211 	.read		= seq_read,
212 	.llseek		= seq_lseek,
213 	.release	= single_release,
214 };
215 
216 static int debugfs_trace_show(struct seq_file *f, void *offset)
217 {
218 	VCHIQ_INSTANCE_T instance = f->private;
219 	int trace;
220 
221 	trace = vchiq_instance_get_trace(instance);
222 	seq_printf(f, "%s\n", trace ? "Y" : "N");
223 
224 	return 0;
225 }
226 
227 static int debugfs_trace_open(struct inode *inode, struct file *file)
228 {
229 	return single_open(file, debugfs_trace_show, inode->i_private);
230 }
231 
232 static ssize_t debugfs_trace_write(struct file *file,
233 	const char __user *buffer,
234 	size_t count, loff_t *ppos)
235 {
236 	struct seq_file *f = (struct seq_file *)file->private_data;
237 	VCHIQ_INSTANCE_T instance = f->private;
238 	char firstchar;
239 
240 	if (copy_from_user(&firstchar, buffer, 1) != 0)
241 		return -EFAULT;
242 
243 	switch (firstchar) {
244 	case 'Y':
245 	case 'y':
246 	case '1':
247 		vchiq_instance_set_trace(instance, 1);
248 		break;
249 	case 'N':
250 	case 'n':
251 	case '0':
252 		vchiq_instance_set_trace(instance, 0);
253 		break;
254 	default:
255 		break;
256 	}
257 
258 	*ppos += count;
259 
260 	return count;
261 }
262 
263 static const struct file_operations debugfs_trace_fops = {
264 	.owner		= THIS_MODULE,
265 	.open		= debugfs_trace_open,
266 	.write		= debugfs_trace_write,
267 	.read		= seq_read,
268 	.llseek		= seq_lseek,
269 	.release	= single_release,
270 };
271 
272 /* add an instance (process) to the debugfs entries */
273 int vchiq_debugfs_add_instance(VCHIQ_INSTANCE_T instance)
274 {
275 	char pidstr[16];
276 	struct dentry *top, *use_count, *trace;
277 	struct dentry *clients = vchiq_clients_top();
278 
279 	snprintf(pidstr, sizeof(pidstr), "%d",
280 		 vchiq_instance_get_pid(instance));
281 
282 	top = debugfs_create_dir(pidstr, clients);
283 	if (!top)
284 		goto fail_top;
285 
286 	use_count = debugfs_create_file("use_count",
287 					0444, top,
288 					instance,
289 					&debugfs_usecount_fops);
290 	if (!use_count)
291 		goto fail_use_count;
292 
293 	trace = debugfs_create_file("trace",
294 				    0644, top,
295 				    instance,
296 				    &debugfs_trace_fops);
297 	if (!trace)
298 		goto fail_trace;
299 
300 	vchiq_instance_get_debugfs_node(instance)->dentry = top;
301 
302 	return 0;
303 
304 fail_trace:
305 	debugfs_remove(use_count);
306 fail_use_count:
307 	debugfs_remove(top);
308 fail_top:
309 	return -ENOMEM;
310 }
311 
312 void vchiq_debugfs_remove_instance(VCHIQ_INSTANCE_T instance)
313 {
314 	VCHIQ_DEBUGFS_NODE_T *node = vchiq_instance_get_debugfs_node(instance);
315 
316 	debugfs_remove_recursive(node->dentry);
317 }
318 
319 
320 int vchiq_debugfs_init(void)
321 {
322 	BUG_ON(debugfs_info.vchiq_cfg_dir != NULL);
323 
324 	debugfs_info.vchiq_cfg_dir = debugfs_create_dir("vchiq", NULL);
325 	if (debugfs_info.vchiq_cfg_dir == NULL)
326 		goto fail;
327 
328 	debugfs_info.clients = debugfs_create_dir("clients",
329 				vchiq_debugfs_top());
330 	if (!debugfs_info.clients)
331 		goto fail;
332 
333 	if (vchiq_debugfs_create_log_entries(vchiq_debugfs_top()) != 0)
334 		goto fail;
335 
336 	return 0;
337 
338 fail:
339 	vchiq_debugfs_deinit();
340 	vchiq_log_error(vchiq_arm_log_level,
341 		"%s: failed to create debugfs directory",
342 		__func__);
343 
344 	return -ENOMEM;
345 }
346 
347 /* remove all the debugfs entries */
348 void vchiq_debugfs_deinit(void)
349 {
350 	debugfs_remove_recursive(vchiq_debugfs_top());
351 }
352 
353 static struct dentry *vchiq_clients_top(void)
354 {
355 	return debugfs_info.clients;
356 }
357 
358 static struct dentry *vchiq_debugfs_top(void)
359 {
360 	BUG_ON(debugfs_info.vchiq_cfg_dir == NULL);
361 	return debugfs_info.vchiq_cfg_dir;
362 }
363 
364 #else /* CONFIG_DEBUG_FS */
365 
366 int vchiq_debugfs_init(void)
367 {
368 	return 0;
369 }
370 
371 void vchiq_debugfs_deinit(void)
372 {
373 }
374 
375 int vchiq_debugfs_add_instance(VCHIQ_INSTANCE_T instance)
376 {
377 	return 0;
378 }
379 
380 void vchiq_debugfs_remove_instance(VCHIQ_INSTANCE_T instance)
381 {
382 }
383 
384 #endif /* CONFIG_DEBUG_FS */
385