1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 *   S/390 debug facility
4 *
5 *    Copyright IBM Corp. 1999, 2020
6 */
7#ifndef _ASM_S390_DEBUG_H
8#define _ASM_S390_DEBUG_H
9
10#include <linux/string.h>
11#include <linux/spinlock.h>
12#include <linux/kernel.h>
13#include <linux/time.h>
14#include <linux/refcount.h>
15#include <linux/fs.h>
16
17#define DEBUG_MAX_LEVEL		   6  /* debug levels range from 0 to 6 */
18#define DEBUG_OFF_LEVEL		   -1 /* level where debug is switched off */
19#define DEBUG_FLUSH_ALL		   -1 /* parameter to flush all areas */
20#define DEBUG_MAX_VIEWS		   10 /* max number of views in proc fs */
21#define DEBUG_MAX_NAME_LEN	   64 /* max length for a debugfs file name */
22#define DEBUG_DEFAULT_LEVEL	   3  /* initial debug level */
23
24#define DEBUG_DIR_ROOT "s390dbf" /* name of debug root directory in proc fs */
25
26#define DEBUG_DATA(entry) (char *)(entry + 1) /* data is stored behind */
27					      /* the entry information */
28
29#define __DEBUG_FEATURE_VERSION	   3  /* version of debug feature */
30
31struct __debug_entry {
32	unsigned long clock	: 60;
33	unsigned long exception	:  1;
34	unsigned long level	:  3;
35	void *caller;
36	unsigned short cpu;
37} __packed;
38
39typedef struct __debug_entry debug_entry_t;
40
41struct debug_view;
42
43typedef struct debug_info {
44	struct debug_info *next;
45	struct debug_info *prev;
46	refcount_t ref_count;
47	spinlock_t lock;
48	int level;
49	int nr_areas;
50	int pages_per_area;
51	int buf_size;
52	int entry_size;
53	debug_entry_t ***areas;
54	int active_area;
55	int *active_pages;
56	int *active_entries;
57	struct dentry *debugfs_root_entry;
58	struct dentry *debugfs_entries[DEBUG_MAX_VIEWS];
59	struct debug_view *views[DEBUG_MAX_VIEWS];
60	char name[DEBUG_MAX_NAME_LEN];
61	umode_t mode;
62} debug_info_t;
63
64typedef int (debug_header_proc_t) (debug_info_t *id,
65				   struct debug_view *view,
66				   int area,
67				   debug_entry_t *entry,
68				   char *out_buf);
69
70typedef int (debug_format_proc_t) (debug_info_t *id,
71				   struct debug_view *view, char *out_buf,
72				   const char *in_buf);
73typedef int (debug_prolog_proc_t) (debug_info_t *id,
74				   struct debug_view *view,
75				   char *out_buf);
76typedef int (debug_input_proc_t) (debug_info_t *id,
77				  struct debug_view *view,
78				  struct file *file,
79				  const char __user *user_buf,
80				  size_t in_buf_size, loff_t *offset);
81
82int debug_dflt_header_fn(debug_info_t *id, struct debug_view *view,
83			 int area, debug_entry_t *entry, char *out_buf);
84
85struct debug_view {
86	char name[DEBUG_MAX_NAME_LEN];
87	debug_prolog_proc_t *prolog_proc;
88	debug_header_proc_t *header_proc;
89	debug_format_proc_t *format_proc;
90	debug_input_proc_t  *input_proc;
91	void		    *private_data;
92};
93
94extern struct debug_view debug_hex_ascii_view;
95extern struct debug_view debug_sprintf_view;
96
97/* do NOT use the _common functions */
98
99debug_entry_t *debug_event_common(debug_info_t *id, int level,
100				  const void *data, int length);
101
102debug_entry_t *debug_exception_common(debug_info_t *id, int level,
103				      const void *data, int length);
104
105/* Debug Feature API: */
106
107debug_info_t *debug_register(const char *name, int pages, int nr_areas,
108			     int buf_size);
109
110debug_info_t *debug_register_mode(const char *name, int pages, int nr_areas,
111				  int buf_size, umode_t mode, uid_t uid,
112				  gid_t gid);
113
114void debug_unregister(debug_info_t *id);
115
116void debug_set_level(debug_info_t *id, int new_level);
117
118void debug_set_critical(void);
119
120void debug_stop_all(void);
121
122/**
123 * debug_level_enabled() - Returns true if debug events for the specified
124 *			   level would be logged. Otherwise returns false.
125 *
126 * @id:		handle for debug log
127 * @level:	debug level
128 *
129 * Return:
130 * - %true if level is less or equal to the current debug level.
131 */
132static inline bool debug_level_enabled(debug_info_t *id, int level)
133{
134	return level <= id->level;
135}
136
137/**
138 * debug_event() - writes binary debug entry to active debug area
139 *		   (if level <= actual debug level)
140 *
141 * @id:		handle for debug log
142 * @level:	debug level
143 * @data:	pointer to data for debug entry
144 * @length:	length of data in bytes
145 *
146 * Return:
147 * - Address of written debug entry
148 * - %NULL if error
149 */
150static inline debug_entry_t *debug_event(debug_info_t *id, int level,
151					 void *data, int length)
152{
153	if ((!id) || (level > id->level) || (id->pages_per_area == 0))
154		return NULL;
155	return debug_event_common(id, level, data, length);
156}
157
158/**
159 * debug_int_event() - writes unsigned integer debug entry to active debug area
160 *		       (if level <= actual debug level)
161 *
162 * @id:		handle for debug log
163 * @level:	debug level
164 * @tag:	integer value for debug entry
165 *
166 * Return:
167 * - Address of written debug entry
168 * - %NULL if error
169 */
170static inline debug_entry_t *debug_int_event(debug_info_t *id, int level,
171					     unsigned int tag)
172{
173	unsigned int t = tag;
174
175	if ((!id) || (level > id->level) || (id->pages_per_area == 0))
176		return NULL;
177	return debug_event_common(id, level, &t, sizeof(unsigned int));
178}
179
180/**
181 * debug_long_event() - writes unsigned long debug entry to active debug area
182 *		       (if level <= actual debug level)
183 *
184 * @id:		handle for debug log
185 * @level:	debug level
186 * @tag:	long integer value for debug entry
187 *
188 * Return:
189 * - Address of written debug entry
190 * - %NULL if error
191 */
192static inline debug_entry_t *debug_long_event(debug_info_t *id, int level,
193					      unsigned long tag)
194{
195	unsigned long t = tag;
196
197	if ((!id) || (level > id->level) || (id->pages_per_area == 0))
198		return NULL;
199	return debug_event_common(id, level, &t, sizeof(unsigned long));
200}
201
202/**
203 * debug_text_event() - writes string debug entry in ascii format to active
204 *			debug area (if level <= actual debug level)
205 *
206 * @id:		handle for debug log
207 * @level:	debug level
208 * @txt:	string for debug entry
209 *
210 * Return:
211 * - Address of written debug entry
212 * - %NULL if error
213 */
214static inline debug_entry_t *debug_text_event(debug_info_t *id, int level,
215					      const char *txt)
216{
217	if ((!id) || (level > id->level) || (id->pages_per_area == 0))
218		return NULL;
219	return debug_event_common(id, level, txt, strlen(txt));
220}
221
222/*
223 * IMPORTANT: Use "%s" in sprintf format strings with care! Only pointers are
224 * stored in the s390dbf. See Documentation/s390/s390dbf.rst for more details!
225 */
226extern debug_entry_t *
227__debug_sprintf_event(debug_info_t *id, int level, char *string, ...)
228	__attribute__ ((format(printf, 3, 4)));
229
230/**
231 * debug_sprintf_event() - writes debug entry with format string
232 *			   and varargs (longs) to active debug area
233 *			   (if level $<=$ actual debug level).
234 *
235 * @_id:	handle for debug log
236 * @_level:	debug level
237 * @_fmt:	format string for debug entry
238 * @...:	varargs used as in sprintf()
239 *
240 * Return:
241 * - Address of written debug entry
242 * - %NULL if error
243 *
244 * floats and long long datatypes cannot be used as varargs.
245 */
246#define debug_sprintf_event(_id, _level, _fmt, ...)			\
247({									\
248	debug_entry_t *__ret;						\
249	debug_info_t *__id = _id;					\
250	int __level = _level;						\
251									\
252	if ((!__id) || (__level > __id->level))				\
253		__ret = NULL;						\
254	else								\
255		__ret = __debug_sprintf_event(__id, __level,		\
256					      _fmt, ## __VA_ARGS__);	\
257	__ret;								\
258})
259
260/**
261 * debug_exception() - writes binary debug entry to active debug area
262 *		       (if level <= actual debug level)
263 *		       and switches to next debug area
264 *
265 * @id:		handle for debug log
266 * @level:	debug level
267 * @data:	pointer to data for debug entry
268 * @length:	length of data in bytes
269 *
270 * Return:
271 * - Address of written debug entry
272 * - %NULL if error
273 */
274static inline debug_entry_t *debug_exception(debug_info_t *id, int level,
275					     void *data, int length)
276{
277	if ((!id) || (level > id->level) || (id->pages_per_area == 0))
278		return NULL;
279	return debug_exception_common(id, level, data, length);
280}
281
282/**
283 * debug_int_exception() - writes unsigned int debug entry to active debug area
284 *			   (if level <= actual debug level)
285 *			   and switches to next debug area
286 *
287 * @id:		handle for debug log
288 * @level:	debug level
289 * @tag:	integer value for debug entry
290 *
291 * Return:
292 * - Address of written debug entry
293 * - %NULL if error
294 */
295static inline debug_entry_t *debug_int_exception(debug_info_t *id, int level,
296						 unsigned int tag)
297{
298	unsigned int t = tag;
299
300	if ((!id) || (level > id->level) || (id->pages_per_area == 0))
301		return NULL;
302	return debug_exception_common(id, level, &t, sizeof(unsigned int));
303}
304
305/**
306 * debug_long_exception() - writes long debug entry to active debug area
307 *			   (if level <= actual debug level)
308 *			   and switches to next debug area
309 *
310 * @id:		handle for debug log
311 * @level:	debug level
312 * @tag:	long integer value for debug entry
313 *
314 * Return:
315 * - Address of written debug entry
316 * - %NULL if error
317 */
318static inline debug_entry_t *debug_long_exception (debug_info_t *id, int level,
319						   unsigned long tag)
320{
321	unsigned long t = tag;
322
323	if ((!id) || (level > id->level) || (id->pages_per_area == 0))
324		return NULL;
325	return debug_exception_common(id, level, &t, sizeof(unsigned long));
326}
327
328/**
329 * debug_text_exception() - writes string debug entry in ascii format to active
330 *			    debug area (if level <= actual debug level)
331 *			    and switches to next debug area
332 * area
333 *
334 * @id:	handle for debug log
335 * @level:	debug level
336 * @txt:	string for debug entry
337 *
338 * Return:
339 * - Address of written debug entry
340 * - %NULL if error
341 */
342static inline debug_entry_t *debug_text_exception(debug_info_t *id, int level,
343						  const char *txt)
344{
345	if ((!id) || (level > id->level) || (id->pages_per_area == 0))
346		return NULL;
347	return debug_exception_common(id, level, txt, strlen(txt));
348}
349
350/*
351 * IMPORTANT: Use "%s" in sprintf format strings with care! Only pointers are
352 * stored in the s390dbf. See Documentation/s390/s390dbf.rst for more details!
353 */
354extern debug_entry_t *
355__debug_sprintf_exception(debug_info_t *id, int level, char *string, ...)
356	__attribute__ ((format(printf, 3, 4)));
357
358
359/**
360 * debug_sprintf_exception() - writes debug entry with format string and
361 *			       varargs (longs) to active debug area
362 *			       (if level <= actual debug level)
363 *			       and switches to next debug area.
364 *
365 * @_id:	handle for debug log
366 * @_level:	debug level
367 * @_fmt:	format string for debug entry
368 * @...:	varargs used as in sprintf()
369 *
370 * Return:
371 * - Address of written debug entry
372 * - %NULL if error
373 *
374 * floats and long long datatypes cannot be used as varargs.
375 */
376#define debug_sprintf_exception(_id, _level, _fmt, ...)			\
377({									\
378	debug_entry_t *__ret;						\
379	debug_info_t *__id = _id;					\
380	int __level = _level;						\
381									\
382	if ((!__id) || (__level > __id->level))				\
383		__ret = NULL;						\
384	else								\
385		__ret = __debug_sprintf_exception(__id, __level,	\
386						  _fmt, ## __VA_ARGS__);\
387	__ret;								\
388})
389
390int debug_register_view(debug_info_t *id, struct debug_view *view);
391
392int debug_unregister_view(debug_info_t *id, struct debug_view *view);
393
394/*
395   define the debug levels:
396   - 0 No debugging output to console or syslog
397   - 1 Log internal errors to syslog, ignore check conditions
398   - 2 Log internal errors and check conditions to syslog
399   - 3 Log internal errors to console, log check conditions to syslog
400   - 4 Log internal errors and check conditions to console
401   - 5 panic on internal errors, log check conditions to console
402   - 6 panic on both, internal errors and check conditions
403 */
404
405#ifndef DEBUG_LEVEL
406#define DEBUG_LEVEL 4
407#endif
408
409#define INTERNAL_ERRMSG(x,y...) "E" __FILE__ "%d: " x, __LINE__, y
410#define INTERNAL_WRNMSG(x,y...) "W" __FILE__ "%d: " x, __LINE__, y
411#define INTERNAL_INFMSG(x,y...) "I" __FILE__ "%d: " x, __LINE__, y
412#define INTERNAL_DEBMSG(x,y...) "D" __FILE__ "%d: " x, __LINE__, y
413
414#if DEBUG_LEVEL > 0
415#define PRINT_DEBUG(x...)	printk(KERN_DEBUG PRINTK_HEADER x)
416#define PRINT_INFO(x...)	printk(KERN_INFO PRINTK_HEADER x)
417#define PRINT_WARN(x...)	printk(KERN_WARNING PRINTK_HEADER x)
418#define PRINT_ERR(x...)		printk(KERN_ERR PRINTK_HEADER x)
419#define PRINT_FATAL(x...)	panic(PRINTK_HEADER x)
420#else
421#define PRINT_DEBUG(x...)	printk(KERN_DEBUG PRINTK_HEADER x)
422#define PRINT_INFO(x...)	printk(KERN_DEBUG PRINTK_HEADER x)
423#define PRINT_WARN(x...)	printk(KERN_DEBUG PRINTK_HEADER x)
424#define PRINT_ERR(x...)		printk(KERN_DEBUG PRINTK_HEADER x)
425#define PRINT_FATAL(x...)	printk(KERN_DEBUG PRINTK_HEADER x)
426#endif /* DASD_DEBUG */
427
428#endif /* _ASM_S390_DEBUG_H */
429