1 /* SPDX-License-Identifier: GPL-2.0 */
5 * Copyright IBM Corp. 1999, 2020
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>
16 #include <linux/init.h>
18 #define DEBUG_MAX_LEVEL 6 /* debug levels range from 0 to 6 */
19 #define DEBUG_OFF_LEVEL -1 /* level where debug is switched off */
20 #define DEBUG_FLUSH_ALL -1 /* parameter to flush all areas */
21 #define DEBUG_MAX_VIEWS 10 /* max number of views in proc fs */
22 #define DEBUG_MAX_NAME_LEN 64 /* max length for a debugfs file name */
23 #define DEBUG_DEFAULT_LEVEL 3 /* initial debug level */
25 #define DEBUG_DIR_ROOT "s390dbf" /* name of debug root directory in proc fs */
27 #define DEBUG_DATA(entry) (char *)(entry + 1) /* data is stored behind */
28 /* the entry information */
30 #define __DEBUG_FEATURE_VERSION 3 /* version of debug feature */
32 struct __debug_entry {
33 unsigned long clock : 60;
34 unsigned long exception : 1;
35 unsigned long level : 3;
40 typedef struct __debug_entry debug_entry_t;
44 typedef struct debug_info {
45 struct debug_info *next;
46 struct debug_info *prev;
54 debug_entry_t ***areas;
58 struct dentry *debugfs_root_entry;
59 struct dentry *debugfs_entries[DEBUG_MAX_VIEWS];
60 struct debug_view *views[DEBUG_MAX_VIEWS];
61 char name[DEBUG_MAX_NAME_LEN];
65 typedef int (debug_header_proc_t) (debug_info_t *id,
66 struct debug_view *view,
71 typedef int (debug_format_proc_t) (debug_info_t *id,
72 struct debug_view *view, char *out_buf,
74 typedef int (debug_prolog_proc_t) (debug_info_t *id,
75 struct debug_view *view,
77 typedef int (debug_input_proc_t) (debug_info_t *id,
78 struct debug_view *view,
80 const char __user *user_buf,
81 size_t in_buf_size, loff_t *offset);
83 int debug_dflt_header_fn(debug_info_t *id, struct debug_view *view,
84 int area, debug_entry_t *entry, char *out_buf);
87 char name[DEBUG_MAX_NAME_LEN];
88 debug_prolog_proc_t *prolog_proc;
89 debug_header_proc_t *header_proc;
90 debug_format_proc_t *format_proc;
91 debug_input_proc_t *input_proc;
95 extern struct debug_view debug_hex_ascii_view;
96 extern struct debug_view debug_sprintf_view;
98 /* do NOT use the _common functions */
100 debug_entry_t *debug_event_common(debug_info_t *id, int level,
101 const void *data, int length);
103 debug_entry_t *debug_exception_common(debug_info_t *id, int level,
104 const void *data, int length);
106 /* Debug Feature API: */
108 debug_info_t *debug_register(const char *name, int pages, int nr_areas,
111 debug_info_t *debug_register_mode(const char *name, int pages, int nr_areas,
112 int buf_size, umode_t mode, uid_t uid,
115 void debug_unregister(debug_info_t *id);
117 void debug_set_level(debug_info_t *id, int new_level);
119 void debug_set_critical(void);
121 void debug_stop_all(void);
124 * debug_level_enabled() - Returns true if debug events for the specified
125 * level would be logged. Otherwise returns false.
127 * @id: handle for debug log
128 * @level: debug level
131 * - %true if level is less or equal to the current debug level.
133 static inline bool debug_level_enabled(debug_info_t *id, int level)
135 return level <= id->level;
139 * debug_event() - writes binary debug entry to active debug area
140 * (if level <= actual debug level)
142 * @id: handle for debug log
143 * @level: debug level
144 * @data: pointer to data for debug entry
145 * @length: length of data in bytes
148 * - Address of written debug entry
151 static inline debug_entry_t *debug_event(debug_info_t *id, int level,
152 void *data, int length)
154 if ((!id) || (level > id->level) || (id->pages_per_area == 0))
156 return debug_event_common(id, level, data, length);
160 * debug_int_event() - writes unsigned integer debug entry to active debug area
161 * (if level <= actual debug level)
163 * @id: handle for debug log
164 * @level: debug level
165 * @tag: integer value for debug entry
168 * - Address of written debug entry
171 static inline debug_entry_t *debug_int_event(debug_info_t *id, int level,
174 unsigned int t = tag;
176 if ((!id) || (level > id->level) || (id->pages_per_area == 0))
178 return debug_event_common(id, level, &t, sizeof(unsigned int));
182 * debug_long_event() - writes unsigned long debug entry to active debug area
183 * (if level <= actual debug level)
185 * @id: handle for debug log
186 * @level: debug level
187 * @tag: long integer value for debug entry
190 * - Address of written debug entry
193 static inline debug_entry_t *debug_long_event(debug_info_t *id, int level,
196 unsigned long t = tag;
198 if ((!id) || (level > id->level) || (id->pages_per_area == 0))
200 return debug_event_common(id, level, &t, sizeof(unsigned long));
204 * debug_text_event() - writes string debug entry in ascii format to active
205 * debug area (if level <= actual debug level)
207 * @id: handle for debug log
208 * @level: debug level
209 * @txt: string for debug entry
212 * - Address of written debug entry
215 static inline debug_entry_t *debug_text_event(debug_info_t *id, int level,
218 if ((!id) || (level > id->level) || (id->pages_per_area == 0))
220 return debug_event_common(id, level, txt, strlen(txt));
224 * IMPORTANT: Use "%s" in sprintf format strings with care! Only pointers are
225 * stored in the s390dbf. See Documentation/s390/s390dbf.rst for more details!
227 extern debug_entry_t *
228 __debug_sprintf_event(debug_info_t *id, int level, char *string, ...)
229 __attribute__ ((format(printf, 3, 4)));
232 * debug_sprintf_event() - writes debug entry with format string
233 * and varargs (longs) to active debug area
234 * (if level $<=$ actual debug level).
236 * @_id: handle for debug log
237 * @_level: debug level
238 * @_fmt: format string for debug entry
239 * @...: varargs used as in sprintf()
242 * - Address of written debug entry
245 * floats and long long datatypes cannot be used as varargs.
247 #define debug_sprintf_event(_id, _level, _fmt, ...) \
249 debug_entry_t *__ret; \
250 debug_info_t *__id = _id; \
251 int __level = _level; \
253 if ((!__id) || (__level > __id->level)) \
256 __ret = __debug_sprintf_event(__id, __level, \
257 _fmt, ## __VA_ARGS__); \
262 * debug_exception() - writes binary debug entry to active debug area
263 * (if level <= actual debug level)
264 * and switches to next debug area
266 * @id: handle for debug log
267 * @level: debug level
268 * @data: pointer to data for debug entry
269 * @length: length of data in bytes
272 * - Address of written debug entry
275 static inline debug_entry_t *debug_exception(debug_info_t *id, int level,
276 void *data, int length)
278 if ((!id) || (level > id->level) || (id->pages_per_area == 0))
280 return debug_exception_common(id, level, data, length);
284 * debug_int_exception() - writes unsigned int debug entry to active debug area
285 * (if level <= actual debug level)
286 * and switches to next debug area
288 * @id: handle for debug log
289 * @level: debug level
290 * @tag: integer value for debug entry
293 * - Address of written debug entry
296 static inline debug_entry_t *debug_int_exception(debug_info_t *id, int level,
299 unsigned int t = tag;
301 if ((!id) || (level > id->level) || (id->pages_per_area == 0))
303 return debug_exception_common(id, level, &t, sizeof(unsigned int));
307 * debug_long_exception() - writes long debug entry to active debug area
308 * (if level <= actual debug level)
309 * and switches to next debug area
311 * @id: handle for debug log
312 * @level: debug level
313 * @tag: long integer value for debug entry
316 * - Address of written debug entry
319 static inline debug_entry_t *debug_long_exception (debug_info_t *id, int level,
322 unsigned long t = tag;
324 if ((!id) || (level > id->level) || (id->pages_per_area == 0))
326 return debug_exception_common(id, level, &t, sizeof(unsigned long));
330 * debug_text_exception() - writes string debug entry in ascii format to active
331 * debug area (if level <= actual debug level)
332 * and switches to next debug area
335 * @id: handle for debug log
336 * @level: debug level
337 * @txt: string for debug entry
340 * - Address of written debug entry
343 static inline debug_entry_t *debug_text_exception(debug_info_t *id, int level,
346 if ((!id) || (level > id->level) || (id->pages_per_area == 0))
348 return debug_exception_common(id, level, txt, strlen(txt));
352 * IMPORTANT: Use "%s" in sprintf format strings with care! Only pointers are
353 * stored in the s390dbf. See Documentation/s390/s390dbf.rst for more details!
355 extern debug_entry_t *
356 __debug_sprintf_exception(debug_info_t *id, int level, char *string, ...)
357 __attribute__ ((format(printf, 3, 4)));
361 * debug_sprintf_exception() - writes debug entry with format string and
362 * varargs (longs) to active debug area
363 * (if level <= actual debug level)
364 * and switches to next debug area.
366 * @_id: handle for debug log
367 * @_level: debug level
368 * @_fmt: format string for debug entry
369 * @...: varargs used as in sprintf()
372 * - Address of written debug entry
375 * floats and long long datatypes cannot be used as varargs.
377 #define debug_sprintf_exception(_id, _level, _fmt, ...) \
379 debug_entry_t *__ret; \
380 debug_info_t *__id = _id; \
381 int __level = _level; \
383 if ((!__id) || (__level > __id->level)) \
386 __ret = __debug_sprintf_exception(__id, __level, \
387 _fmt, ## __VA_ARGS__);\
391 int debug_register_view(debug_info_t *id, struct debug_view *view);
393 int debug_unregister_view(debug_info_t *id, struct debug_view *view);
398 * Note: Initial page and area numbers must be fixed to allow static
399 * initialization. This enables very early tracing. Changes to these values
400 * must be reflected in __DEFINE_STATIC_AREA.
402 #define EARLY_PAGES 8
403 #define EARLY_AREAS 1
405 #define VNAME(var, suffix) __##var##_##suffix
408 * Define static areas for early trace data. During boot debug_register_static()
409 * will replace these with dynamically allocated areas to allow custom page and
410 * area sizes, and dynamic resizing.
412 #define __DEFINE_STATIC_AREA(var) \
413 static char VNAME(var, data)[EARLY_PAGES][PAGE_SIZE] __initdata; \
414 static debug_entry_t *VNAME(var, pages)[EARLY_PAGES] __initdata = { \
415 (debug_entry_t *)VNAME(var, data)[0], \
416 (debug_entry_t *)VNAME(var, data)[1], \
417 (debug_entry_t *)VNAME(var, data)[2], \
418 (debug_entry_t *)VNAME(var, data)[3], \
419 (debug_entry_t *)VNAME(var, data)[4], \
420 (debug_entry_t *)VNAME(var, data)[5], \
421 (debug_entry_t *)VNAME(var, data)[6], \
422 (debug_entry_t *)VNAME(var, data)[7], \
424 static debug_entry_t **VNAME(var, areas)[EARLY_AREAS] __initdata = { \
425 (debug_entry_t **)VNAME(var, pages), \
427 static int VNAME(var, active_pages)[EARLY_AREAS] __initdata; \
428 static int VNAME(var, active_entries)[EARLY_AREAS] __initdata
430 #define __DEBUG_INFO_INIT(var, _name, _buf_size) { \
433 .ref_count = REFCOUNT_INIT(1), \
434 .lock = __SPIN_LOCK_UNLOCKED(var.lock), \
435 .level = DEBUG_DEFAULT_LEVEL, \
436 .nr_areas = EARLY_AREAS, \
437 .pages_per_area = EARLY_PAGES, \
438 .buf_size = (_buf_size), \
439 .entry_size = sizeof(debug_entry_t) + (_buf_size), \
440 .areas = VNAME(var, areas), \
442 .active_pages = VNAME(var, active_pages), \
443 .active_entries = VNAME(var, active_entries), \
444 .debugfs_root_entry = NULL, \
445 .debugfs_entries = { NULL }, \
451 #define __REGISTER_STATIC_DEBUG_INFO(var, name, pages, areas, view) \
452 static int __init VNAME(var, reg)(void) \
454 debug_register_static(&var, (pages), (areas)); \
455 debug_register_view(&var, (view)); \
458 arch_initcall(VNAME(var, reg))
461 * DEFINE_STATIC_DEBUG_INFO - Define static debug_info_t
463 * @var: Name of debug_info_t variable
464 * @name: Name of debug log (e.g. used for debugfs entry)
465 * @pages: Number of pages per area
466 * @nr_areas: Number of debug areas
467 * @buf_size: Size of data area in each debug entry
468 * @view: Pointer to debug view struct
470 * Define a static debug_info_t for early tracing. The associated debugfs log
471 * is automatically registered with the specified debug view.
473 * Important: Users of this macro must not call any of the
474 * debug_register/_unregister() functions for this debug_info_t!
476 * Note: Tracing will start with a fixed number of initial pages and areas.
477 * The debug area will be changed to use the specified numbers during
480 #define DEFINE_STATIC_DEBUG_INFO(var, name, pages, nr_areas, buf_size, view) \
481 __DEFINE_STATIC_AREA(var); \
482 static debug_info_t __refdata var = \
483 __DEBUG_INFO_INIT(var, (name), (buf_size)); \
484 __REGISTER_STATIC_DEBUG_INFO(var, name, pages, nr_areas, view)
486 void debug_register_static(debug_info_t *id, int pages_per_area, int nr_areas);