sysctl: Drop & in front of every proc_handler.
[linux-2.6.git] / arch / s390 / kernel / debug.c
1 /*
2  *  arch/s390/kernel/debug.c
3  *   S/390 debug facility
4  *
5  *    Copyright (C) 1999, 2000 IBM Deutschland Entwicklung GmbH,
6  *                             IBM Corporation
7  *    Author(s): Michael Holzheu (holzheu@de.ibm.com),
8  *               Holger Smolinski (Holger.Smolinski@de.ibm.com)
9  *
10  *    Bugreports to: <Linux390@de.ibm.com>
11  */
12
13 #define KMSG_COMPONENT "s390dbf"
14 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
15
16 #include <linux/stddef.h>
17 #include <linux/kernel.h>
18 #include <linux/errno.h>
19 #include <linux/slab.h>
20 #include <linux/ctype.h>
21 #include <linux/sysctl.h>
22 #include <asm/uaccess.h>
23 #include <linux/module.h>
24 #include <linux/init.h>
25 #include <linux/fs.h>
26 #include <linux/debugfs.h>
27
28 #include <asm/debug.h>
29
30 #define DEBUG_PROLOG_ENTRY -1
31
32 #define ALL_AREAS 0 /* copy all debug areas */
33 #define NO_AREAS  1 /* copy no debug areas */
34
35 /* typedefs */
36
37 typedef struct file_private_info {
38         loff_t offset;                  /* offset of last read in file */
39         int    act_area;                /* number of last formated area */
40         int    act_page;                /* act page in given area */
41         int    act_entry;               /* last formated entry (offset */
42                                         /* relative to beginning of last */
43                                         /* formated page) */
44         size_t act_entry_offset;        /* up to this offset we copied */
45                                         /* in last read the last formated */
46                                         /* entry to userland */
47         char   temp_buf[2048];          /* buffer for output */
48         debug_info_t *debug_info_org;   /* original debug information */
49         debug_info_t *debug_info_snap;  /* snapshot of debug information */
50         struct debug_view *view;        /* used view of debug info */
51 } file_private_info_t;
52
53 typedef struct
54 {
55         char *string;
56         /* 
57          * This assumes that all args are converted into longs 
58          * on L/390 this is the case for all types of parameter 
59          * except of floats, and long long (32 bit) 
60          *
61          */
62         long args[0];
63 } debug_sprintf_entry_t;
64
65
66 /* internal function prototyes */
67
68 static int debug_init(void);
69 static ssize_t debug_output(struct file *file, char __user *user_buf,
70                         size_t user_len, loff_t * offset);
71 static ssize_t debug_input(struct file *file, const char __user *user_buf,
72                         size_t user_len, loff_t * offset);
73 static int debug_open(struct inode *inode, struct file *file);
74 static int debug_close(struct inode *inode, struct file *file);
75 static debug_info_t *debug_info_create(const char *name, int pages_per_area,
76                         int nr_areas, int buf_size, mode_t mode);
77 static void debug_info_get(debug_info_t *);
78 static void debug_info_put(debug_info_t *);
79 static int debug_prolog_level_fn(debug_info_t * id,
80                         struct debug_view *view, char *out_buf);
81 static int debug_input_level_fn(debug_info_t * id, struct debug_view *view,
82                         struct file *file, const char __user *user_buf,
83                         size_t user_buf_size, loff_t * offset);
84 static int debug_prolog_pages_fn(debug_info_t * id,
85                         struct debug_view *view, char *out_buf);
86 static int debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
87                         struct file *file, const char __user *user_buf,
88                         size_t user_buf_size, loff_t * offset);
89 static int debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
90                         struct file *file, const char __user *user_buf,
91                         size_t user_buf_size, loff_t * offset);
92 static int debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
93                         char *out_buf, const char *in_buf);
94 static int debug_raw_format_fn(debug_info_t * id,
95                         struct debug_view *view, char *out_buf,
96                         const char *in_buf);
97 static int debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
98                         int area, debug_entry_t * entry, char *out_buf);
99
100 static int debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
101                         char *out_buf, debug_sprintf_entry_t *curr_event);
102
103 /* globals */
104
105 struct debug_view debug_raw_view = {
106         "raw",
107         NULL,
108         &debug_raw_header_fn,
109         &debug_raw_format_fn,
110         NULL,
111         NULL
112 };
113
114 struct debug_view debug_hex_ascii_view = {
115         "hex_ascii",
116         NULL,
117         &debug_dflt_header_fn,
118         &debug_hex_ascii_format_fn,
119         NULL,
120         NULL
121 };
122
123 static struct debug_view debug_level_view = {
124         "level",
125         &debug_prolog_level_fn,
126         NULL,
127         NULL,
128         &debug_input_level_fn,
129         NULL
130 };
131
132 static struct debug_view debug_pages_view = {
133         "pages",
134         &debug_prolog_pages_fn,
135         NULL,
136         NULL,
137         &debug_input_pages_fn,
138         NULL
139 };
140
141 static struct debug_view debug_flush_view = {
142         "flush",
143         NULL,
144         NULL,
145         NULL,
146         &debug_input_flush_fn,
147         NULL
148 };
149
150 struct debug_view debug_sprintf_view = {
151         "sprintf",
152         NULL,
153         &debug_dflt_header_fn,
154         (debug_format_proc_t*)&debug_sprintf_format_fn,
155         NULL,
156         NULL
157 };
158
159 /* used by dump analysis tools to determine version of debug feature */
160 static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION;
161
162 /* static globals */
163
164 static debug_info_t *debug_area_first = NULL;
165 static debug_info_t *debug_area_last = NULL;
166 static DEFINE_MUTEX(debug_mutex);
167
168 static int initialized;
169
170 static const struct file_operations debug_file_ops = {
171         .owner   = THIS_MODULE,
172         .read    = debug_output,
173         .write   = debug_input,
174         .open    = debug_open,
175         .release = debug_close,
176 };
177
178 static struct dentry *debug_debugfs_root_entry;
179
180 /* functions */
181
182 /*
183  * debug_areas_alloc
184  * - Debug areas are implemented as a threedimensonal array:
185  *   areas[areanumber][pagenumber][pageoffset]
186  */
187
188 static debug_entry_t***
189 debug_areas_alloc(int pages_per_area, int nr_areas)
190 {
191         debug_entry_t*** areas;
192         int i,j;
193
194         areas = kmalloc(nr_areas *
195                                         sizeof(debug_entry_t**),
196                                         GFP_KERNEL);
197         if (!areas)
198                 goto fail_malloc_areas;
199         for (i = 0; i < nr_areas; i++) {
200                 areas[i] = kmalloc(pages_per_area *
201                                 sizeof(debug_entry_t*),GFP_KERNEL);
202                 if (!areas[i]) {
203                         goto fail_malloc_areas2;
204                 }
205                 for(j = 0; j < pages_per_area; j++) {
206                         areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL);
207                         if(!areas[i][j]) {
208                                 for(j--; j >=0 ; j--) {
209                                         kfree(areas[i][j]);
210                                 }
211                                 kfree(areas[i]);
212                                 goto fail_malloc_areas2;
213                         }
214                 }
215         }
216         return areas;
217
218 fail_malloc_areas2:
219         for(i--; i >= 0; i--){
220                 for(j=0; j < pages_per_area;j++){
221                         kfree(areas[i][j]);
222                 }
223                 kfree(areas[i]);
224         }
225         kfree(areas);
226 fail_malloc_areas:
227         return NULL;
228
229 }
230
231
232 /*
233  * debug_info_alloc
234  * - alloc new debug-info
235  */
236
237 static debug_info_t*
238 debug_info_alloc(const char *name, int pages_per_area, int nr_areas,
239                  int buf_size, int level, int mode)
240 {
241         debug_info_t* rc;
242
243         /* alloc everything */
244
245         rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL);
246         if(!rc)
247                 goto fail_malloc_rc;
248         rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
249         if(!rc->active_entries)
250                 goto fail_malloc_active_entries;
251         rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
252         if(!rc->active_pages)
253                 goto fail_malloc_active_pages;
254         if((mode == ALL_AREAS) && (pages_per_area != 0)){
255                 rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
256                 if(!rc->areas)
257                         goto fail_malloc_areas;
258         } else {
259                 rc->areas = NULL;
260         }
261
262         /* initialize members */
263
264         spin_lock_init(&rc->lock);
265         rc->pages_per_area = pages_per_area;
266         rc->nr_areas       = nr_areas;
267         rc->active_area    = 0;
268         rc->level          = level;
269         rc->buf_size       = buf_size;
270         rc->entry_size     = sizeof(debug_entry_t) + buf_size;
271         strlcpy(rc->name, name, sizeof(rc->name));
272         memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
273         memset(rc->debugfs_entries, 0 ,DEBUG_MAX_VIEWS *
274                 sizeof(struct dentry*));
275         atomic_set(&(rc->ref_count), 0);
276
277         return rc;
278
279 fail_malloc_areas:
280         kfree(rc->active_pages);
281 fail_malloc_active_pages:
282         kfree(rc->active_entries);
283 fail_malloc_active_entries:
284         kfree(rc);
285 fail_malloc_rc:
286         return NULL;
287 }
288
289 /*
290  * debug_areas_free
291  * - free all debug areas
292  */
293
294 static void
295 debug_areas_free(debug_info_t* db_info)
296 {
297         int i,j;
298
299         if(!db_info->areas)
300                 return;
301         for (i = 0; i < db_info->nr_areas; i++) {
302                 for(j = 0; j < db_info->pages_per_area; j++) {
303                         kfree(db_info->areas[i][j]);
304                 }
305                 kfree(db_info->areas[i]);
306         }
307         kfree(db_info->areas);
308         db_info->areas = NULL;
309 }
310
311 /*
312  * debug_info_free
313  * - free memory debug-info
314  */
315
316 static void
317 debug_info_free(debug_info_t* db_info){
318         debug_areas_free(db_info);
319         kfree(db_info->active_entries);
320         kfree(db_info->active_pages);
321         kfree(db_info);
322 }
323
324 /*
325  * debug_info_create
326  * - create new debug-info
327  */
328
329 static debug_info_t*
330 debug_info_create(const char *name, int pages_per_area, int nr_areas,
331                   int buf_size, mode_t mode)
332 {
333         debug_info_t* rc;
334
335         rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size,
336                                 DEBUG_DEFAULT_LEVEL, ALL_AREAS);
337         if(!rc) 
338                 goto out;
339
340         rc->mode = mode & ~S_IFMT;
341
342         /* create root directory */
343         rc->debugfs_root_entry = debugfs_create_dir(rc->name,
344                                         debug_debugfs_root_entry);
345
346         /* append new element to linked list */
347         if (!debug_area_first) {
348                 /* first element in list */
349                 debug_area_first = rc;
350                 rc->prev = NULL;
351         } else {
352                 /* append element to end of list */
353                 debug_area_last->next = rc;
354                 rc->prev = debug_area_last;
355         }
356         debug_area_last = rc;
357         rc->next = NULL;
358
359         debug_info_get(rc);
360 out:
361         return rc;
362 }
363
364 /*
365  * debug_info_copy
366  * - copy debug-info
367  */
368
369 static debug_info_t*
370 debug_info_copy(debug_info_t* in, int mode)
371 {
372         int i,j;
373         debug_info_t* rc;
374         unsigned long flags;
375
376         /* get a consistent copy of the debug areas */
377         do {
378                 rc = debug_info_alloc(in->name, in->pages_per_area,
379                         in->nr_areas, in->buf_size, in->level, mode);
380                 spin_lock_irqsave(&in->lock, flags);
381                 if(!rc)
382                         goto out;
383                 /* has something changed in the meantime ? */
384                 if((rc->pages_per_area == in->pages_per_area) &&
385                    (rc->nr_areas == in->nr_areas)) {
386                         break;
387                 }
388                 spin_unlock_irqrestore(&in->lock, flags);
389                 debug_info_free(rc);
390         } while (1);
391
392         if (mode == NO_AREAS)
393                 goto out;
394
395         for(i = 0; i < in->nr_areas; i++){
396                 for(j = 0; j < in->pages_per_area; j++) {
397                         memcpy(rc->areas[i][j], in->areas[i][j],PAGE_SIZE);
398                 }
399         }
400 out:
401         spin_unlock_irqrestore(&in->lock, flags);
402         return rc;
403 }
404
405 /*
406  * debug_info_get
407  * - increments reference count for debug-info
408  */
409
410 static void
411 debug_info_get(debug_info_t * db_info)
412 {
413         if (db_info)
414                 atomic_inc(&db_info->ref_count);
415 }
416
417 /*
418  * debug_info_put:
419  * - decreases reference count for debug-info and frees it if necessary
420  */
421
422 static void
423 debug_info_put(debug_info_t *db_info)
424 {
425         int i;
426
427         if (!db_info)
428                 return;
429         if (atomic_dec_and_test(&db_info->ref_count)) {
430                 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
431                         if (!db_info->views[i])
432                                 continue;
433                         debugfs_remove(db_info->debugfs_entries[i]);
434                 }
435                 debugfs_remove(db_info->debugfs_root_entry);
436                 if(db_info == debug_area_first)
437                         debug_area_first = db_info->next;
438                 if(db_info == debug_area_last)
439                         debug_area_last = db_info->prev;
440                 if(db_info->prev) db_info->prev->next = db_info->next;
441                 if(db_info->next) db_info->next->prev = db_info->prev;
442                 debug_info_free(db_info);
443         }
444 }
445
446 /*
447  * debug_format_entry:
448  * - format one debug entry and return size of formated data
449  */
450
451 static int
452 debug_format_entry(file_private_info_t *p_info)
453 {
454         debug_info_t *id_snap   = p_info->debug_info_snap;
455         struct debug_view *view = p_info->view;
456         debug_entry_t *act_entry;
457         size_t len = 0;
458         if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
459                 /* print prolog */
460                 if (view->prolog_proc)
461                         len += view->prolog_proc(id_snap,view,p_info->temp_buf);
462                 goto out;
463         }
464         if (!id_snap->areas) /* this is true, if we have a prolog only view */
465                 goto out;    /* or if 'pages_per_area' is 0 */
466         act_entry = (debug_entry_t *) ((char*)id_snap->areas[p_info->act_area]
467                                 [p_info->act_page] + p_info->act_entry);
468                         
469         if (act_entry->id.stck == 0LL)
470                         goto out;  /* empty entry */
471         if (view->header_proc)
472                 len += view->header_proc(id_snap, view, p_info->act_area,
473                                         act_entry, p_info->temp_buf + len);
474         if (view->format_proc)
475                 len += view->format_proc(id_snap, view, p_info->temp_buf + len,
476                                                 DEBUG_DATA(act_entry));
477 out:
478         return len;
479 }
480
481 /*
482  * debug_next_entry:
483  * - goto next entry in p_info
484  */
485
486 static inline int
487 debug_next_entry(file_private_info_t *p_info)
488 {
489         debug_info_t *id;
490
491         id = p_info->debug_info_snap;
492         if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
493                 p_info->act_entry = 0;
494                 p_info->act_page  = 0;
495                 goto out;
496         }
497         if(!id->areas)
498                 return 1;
499         p_info->act_entry += id->entry_size;
500         /* switch to next page, if we reached the end of the page  */
501         if (p_info->act_entry > (PAGE_SIZE - id->entry_size)){
502                 /* next page */
503                 p_info->act_entry = 0;
504                 p_info->act_page += 1;
505                 if((p_info->act_page % id->pages_per_area) == 0) {
506                         /* next area */
507                         p_info->act_area++;
508                         p_info->act_page=0;
509                 }
510                 if(p_info->act_area >= id->nr_areas)
511                         return 1;
512         }
513 out:
514         return 0;       
515 }
516
517 /*
518  * debug_output:
519  * - called for user read()
520  * - copies formated debug entries to the user buffer
521  */
522
523 static ssize_t
524 debug_output(struct file *file,         /* file descriptor */
525             char __user *user_buf,      /* user buffer */
526             size_t  len,                /* length of buffer */
527             loff_t *offset)             /* offset in the file */
528 {
529         size_t count = 0;
530         size_t entry_offset;
531         file_private_info_t *p_info;
532
533         p_info = ((file_private_info_t *) file->private_data);
534         if (*offset != p_info->offset) 
535                 return -EPIPE;
536         if(p_info->act_area >= p_info->debug_info_snap->nr_areas)
537                 return 0;
538         entry_offset = p_info->act_entry_offset;
539         while(count < len){
540                 int formatted_line_size;
541                 int formatted_line_residue;
542                 int user_buf_residue;
543                 size_t copy_size;
544
545                 formatted_line_size = debug_format_entry(p_info);
546                 formatted_line_residue = formatted_line_size - entry_offset;
547                 user_buf_residue = len-count;
548                 copy_size = min(user_buf_residue, formatted_line_residue);
549                 if(copy_size){
550                         if (copy_to_user(user_buf + count, p_info->temp_buf
551                                         + entry_offset, copy_size))
552                                 return -EFAULT;
553                         count += copy_size;
554                         entry_offset += copy_size;
555                 }
556                 if(copy_size == formatted_line_residue){
557                         entry_offset = 0;
558                         if(debug_next_entry(p_info))
559                                 goto out;
560                 }
561         }
562 out:
563         p_info->offset           = *offset + count;
564         p_info->act_entry_offset = entry_offset;
565         *offset = p_info->offset;
566         return count;
567 }
568
569 /*
570  * debug_input:
571  * - called for user write()
572  * - calls input function of view
573  */
574
575 static ssize_t
576 debug_input(struct file *file, const char __user *user_buf, size_t length,
577                 loff_t *offset)
578 {
579         int rc = 0;
580         file_private_info_t *p_info;
581
582         mutex_lock(&debug_mutex);
583         p_info = ((file_private_info_t *) file->private_data);
584         if (p_info->view->input_proc)
585                 rc = p_info->view->input_proc(p_info->debug_info_org,
586                                               p_info->view, file, user_buf,
587                                               length, offset);
588         else
589                 rc = -EPERM;
590         mutex_unlock(&debug_mutex);
591         return rc;              /* number of input characters */
592 }
593
594 /*
595  * debug_open:
596  * - called for user open()
597  * - copies formated output to private_data area of the file
598  *   handle
599  */
600
601 static int
602 debug_open(struct inode *inode, struct file *file)
603 {
604         int i, rc = 0;
605         file_private_info_t *p_info;
606         debug_info_t *debug_info, *debug_info_snapshot;
607
608         mutex_lock(&debug_mutex);
609         debug_info = file->f_path.dentry->d_inode->i_private;
610         /* find debug view */
611         for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
612                 if (!debug_info->views[i])
613                         continue;
614                 else if (debug_info->debugfs_entries[i] ==
615                          file->f_path.dentry) {
616                         goto found;     /* found view ! */
617                 }
618         }
619         /* no entry found */
620         rc = -EINVAL;
621         goto out;
622
623 found:
624
625         /* Make snapshot of current debug areas to get it consistent.     */
626         /* To copy all the areas is only needed, if we have a view which  */
627         /* formats the debug areas. */
628
629         if(!debug_info->views[i]->format_proc &&
630                 !debug_info->views[i]->header_proc){
631                 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS);
632         } else {
633                 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS);
634         }
635
636         if(!debug_info_snapshot){
637                 rc = -ENOMEM;
638                 goto out;
639         }
640         p_info = kmalloc(sizeof(file_private_info_t),
641                                                 GFP_KERNEL);
642         if(!p_info){
643                 debug_info_free(debug_info_snapshot);
644                 rc = -ENOMEM;
645                 goto out;
646         }
647         p_info->offset = 0;
648         p_info->debug_info_snap = debug_info_snapshot;
649         p_info->debug_info_org  = debug_info;
650         p_info->view = debug_info->views[i];
651         p_info->act_area = 0;
652         p_info->act_page = 0;
653         p_info->act_entry = DEBUG_PROLOG_ENTRY;
654         p_info->act_entry_offset = 0;
655         file->private_data = p_info;
656         debug_info_get(debug_info);
657 out:
658         mutex_unlock(&debug_mutex);
659         return rc;
660 }
661
662 /*
663  * debug_close:
664  * - called for user close()
665  * - deletes  private_data area of the file handle
666  */
667
668 static int
669 debug_close(struct inode *inode, struct file *file)
670 {
671         file_private_info_t *p_info;
672         p_info = (file_private_info_t *) file->private_data;
673         if(p_info->debug_info_snap)
674                 debug_info_free(p_info->debug_info_snap);
675         debug_info_put(p_info->debug_info_org);
676         kfree(file->private_data);
677         return 0;               /* success */
678 }
679
680 /*
681  * debug_register_mode:
682  * - Creates and initializes debug area for the caller
683  *   The mode parameter allows to specify access rights for the s390dbf files
684  * - Returns handle for debug area
685  */
686
687 debug_info_t *debug_register_mode(const char *name, int pages_per_area,
688                                   int nr_areas, int buf_size, mode_t mode,
689                                   uid_t uid, gid_t gid)
690 {
691         debug_info_t *rc = NULL;
692
693         /* Since debugfs currently does not support uid/gid other than root, */
694         /* we do not allow gid/uid != 0 until we get support for that. */
695         if ((uid != 0) || (gid != 0))
696                 pr_warning("Root becomes the owner of all s390dbf files "
697                            "in sysfs\n");
698         BUG_ON(!initialized);
699         mutex_lock(&debug_mutex);
700
701         /* create new debug_info */
702
703         rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
704         if(!rc) 
705                 goto out;
706         debug_register_view(rc, &debug_level_view);
707         debug_register_view(rc, &debug_flush_view);
708         debug_register_view(rc, &debug_pages_view);
709 out:
710         if (!rc){
711                 pr_err("Registering debug feature %s failed\n", name);
712         }
713         mutex_unlock(&debug_mutex);
714         return rc;
715 }
716 EXPORT_SYMBOL(debug_register_mode);
717
718 /*
719  * debug_register:
720  * - creates and initializes debug area for the caller
721  * - returns handle for debug area
722  */
723
724 debug_info_t *debug_register(const char *name, int pages_per_area,
725                              int nr_areas, int buf_size)
726 {
727         return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
728                                    S_IRUSR | S_IWUSR, 0, 0);
729 }
730
731 /*
732  * debug_unregister:
733  * - give back debug area
734  */
735
736 void
737 debug_unregister(debug_info_t * id)
738 {
739         if (!id)
740                 goto out;
741         mutex_lock(&debug_mutex);
742         debug_info_put(id);
743         mutex_unlock(&debug_mutex);
744
745 out:
746         return;
747 }
748
749 /*
750  * debug_set_size:
751  * - set area size (number of pages) and number of areas
752  */
753 static int
754 debug_set_size(debug_info_t* id, int nr_areas, int pages_per_area)
755 {
756         unsigned long flags;
757         debug_entry_t *** new_areas;
758         int rc=0;
759
760         if(!id || (nr_areas <= 0) || (pages_per_area < 0))
761                 return -EINVAL;
762         if(pages_per_area > 0){
763                 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
764                 if(!new_areas) {
765                         pr_info("Allocating memory for %i pages failed\n",
766                                 pages_per_area);
767                         rc = -ENOMEM;
768                         goto out;
769                 }
770         } else {
771                 new_areas = NULL;
772         }
773         spin_lock_irqsave(&id->lock,flags);
774         debug_areas_free(id);
775         id->areas = new_areas;
776         id->nr_areas = nr_areas;
777         id->pages_per_area = pages_per_area;
778         id->active_area = 0;
779         memset(id->active_entries,0,sizeof(int)*id->nr_areas);
780         memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
781         spin_unlock_irqrestore(&id->lock,flags);
782         pr_info("%s: set new size (%i pages)\n" ,id->name, pages_per_area);
783 out:
784         return rc;
785 }
786
787 /*
788  * debug_set_level:
789  * - set actual debug level
790  */
791
792 void
793 debug_set_level(debug_info_t* id, int new_level)
794 {
795         unsigned long flags;
796         if(!id)
797                 return; 
798         spin_lock_irqsave(&id->lock,flags);
799         if(new_level == DEBUG_OFF_LEVEL){
800                 id->level = DEBUG_OFF_LEVEL;
801                 pr_info("%s: switched off\n",id->name);
802         } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
803                 pr_info("%s: level %i is out of range (%i - %i)\n",
804                         id->name, new_level, 0, DEBUG_MAX_LEVEL);
805         } else {
806                 id->level = new_level;
807         }
808         spin_unlock_irqrestore(&id->lock,flags);
809 }
810
811
812 /*
813  * proceed_active_entry:
814  * - set active entry to next in the ring buffer
815  */
816
817 static inline void
818 proceed_active_entry(debug_info_t * id)
819 {
820         if ((id->active_entries[id->active_area] += id->entry_size)
821             > (PAGE_SIZE - id->entry_size)){
822                 id->active_entries[id->active_area] = 0;
823                 id->active_pages[id->active_area] =
824                         (id->active_pages[id->active_area] + 1) %
825                         id->pages_per_area;
826         }
827 }
828
829 /*
830  * proceed_active_area:
831  * - set active area to next in the ring buffer
832  */
833
834 static inline void
835 proceed_active_area(debug_info_t * id)
836 {
837         id->active_area++;
838         id->active_area = id->active_area % id->nr_areas;
839 }
840
841 /*
842  * get_active_entry:
843  */
844
845 static inline debug_entry_t*
846 get_active_entry(debug_info_t * id)
847 {
848         return (debug_entry_t *) (((char *) id->areas[id->active_area]
849                                         [id->active_pages[id->active_area]]) +
850                                         id->active_entries[id->active_area]);
851 }
852
853 /*
854  * debug_finish_entry:
855  * - set timestamp, caller address, cpu number etc.
856  */
857
858 static inline void
859 debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level,
860                         int exception)
861 {
862         active->id.stck = get_clock();
863         active->id.fields.cpuid = smp_processor_id();
864         active->caller = __builtin_return_address(0);
865         active->id.fields.exception = exception;
866         active->id.fields.level     = level;
867         proceed_active_entry(id);
868         if(exception)
869                 proceed_active_area(id);
870 }
871
872 static int debug_stoppable=1;
873 static int debug_active=1;
874
875 #define CTL_S390DBF_STOPPABLE 5678
876 #define CTL_S390DBF_ACTIVE 5679
877
878 /*
879  * proc handler for the running debug_active sysctl
880  * always allow read, allow write only if debug_stoppable is set or
881  * if debug_active is already off
882  */
883 static int
884 s390dbf_procactive(ctl_table *table, int write,
885                      void __user *buffer, size_t *lenp, loff_t *ppos)
886 {
887         if (!write || debug_stoppable || !debug_active)
888                 return proc_dointvec(table, write, buffer, lenp, ppos);
889         else
890                 return 0;
891 }
892
893
894 static struct ctl_table s390dbf_table[] = {
895         {
896                 .procname       = "debug_stoppable",
897                 .data           = &debug_stoppable,
898                 .maxlen         = sizeof(int),
899                 .mode           = S_IRUGO | S_IWUSR,
900                 .proc_handler   = proc_dointvec,
901         },
902          {
903                 .procname       = "debug_active",
904                 .data           = &debug_active,
905                 .maxlen         = sizeof(int),
906                 .mode           = S_IRUGO | S_IWUSR,
907                 .proc_handler   = s390dbf_procactive,
908         },
909         { }
910 };
911
912 static struct ctl_table s390dbf_dir_table[] = {
913         {
914                 .procname       = "s390dbf",
915                 .maxlen         = 0,
916                 .mode           = S_IRUGO | S_IXUGO,
917                 .child          = s390dbf_table,
918         },
919         { }
920 };
921
922 static struct ctl_table_header *s390dbf_sysctl_header;
923
924 void
925 debug_stop_all(void)
926 {
927         if (debug_stoppable)
928                 debug_active = 0;
929 }
930
931
932 /*
933  * debug_event_common:
934  * - write debug entry with given size
935  */
936
937 debug_entry_t*
938 debug_event_common(debug_info_t * id, int level, const void *buf, int len)
939 {
940         unsigned long flags;
941         debug_entry_t *active;
942
943         if (!debug_active || !id->areas)
944                 return NULL;
945         spin_lock_irqsave(&id->lock, flags);
946         active = get_active_entry(id);
947         memset(DEBUG_DATA(active), 0, id->buf_size);
948         memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
949         debug_finish_entry(id, active, level, 0);
950         spin_unlock_irqrestore(&id->lock, flags);
951
952         return active;
953 }
954
955 /*
956  * debug_exception_common:
957  * - write debug entry with given size and switch to next debug area
958  */
959
960 debug_entry_t
961 *debug_exception_common(debug_info_t * id, int level, const void *buf, int len)
962 {
963         unsigned long flags;
964         debug_entry_t *active;
965
966         if (!debug_active || !id->areas)
967                 return NULL;
968         spin_lock_irqsave(&id->lock, flags);
969         active = get_active_entry(id);
970         memset(DEBUG_DATA(active), 0, id->buf_size);
971         memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
972         debug_finish_entry(id, active, level, 1);
973         spin_unlock_irqrestore(&id->lock, flags);
974
975         return active;
976 }
977
978 /*
979  * counts arguments in format string for sprintf view
980  */
981
982 static inline int
983 debug_count_numargs(char *string)
984 {
985         int numargs=0;
986
987         while(*string) {
988                 if(*string++=='%')
989                         numargs++;
990         }
991         return(numargs);
992 }
993
994 /*
995  * debug_sprintf_event:
996  */
997
998 debug_entry_t*
999 debug_sprintf_event(debug_info_t* id, int level,char *string,...)
1000 {
1001         va_list   ap;
1002         int numargs,idx;
1003         unsigned long flags;
1004         debug_sprintf_entry_t *curr_event;
1005         debug_entry_t *active;
1006
1007         if((!id) || (level > id->level))
1008                 return NULL;
1009         if (!debug_active || !id->areas)
1010                 return NULL;
1011         numargs=debug_count_numargs(string);
1012
1013         spin_lock_irqsave(&id->lock, flags);
1014         active = get_active_entry(id);
1015         curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active);
1016         va_start(ap,string);
1017         curr_event->string=string;
1018         for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1019                 curr_event->args[idx]=va_arg(ap,long);
1020         va_end(ap);
1021         debug_finish_entry(id, active, level, 0);
1022         spin_unlock_irqrestore(&id->lock, flags);
1023
1024         return active;
1025 }
1026
1027 /*
1028  * debug_sprintf_exception:
1029  */
1030
1031 debug_entry_t*
1032 debug_sprintf_exception(debug_info_t* id, int level,char *string,...)
1033 {
1034         va_list   ap;
1035         int numargs,idx;
1036         unsigned long flags;
1037         debug_sprintf_entry_t *curr_event;
1038         debug_entry_t *active;
1039
1040         if((!id) || (level > id->level))
1041                 return NULL;
1042         if (!debug_active || !id->areas)
1043                 return NULL;
1044
1045         numargs=debug_count_numargs(string);
1046
1047         spin_lock_irqsave(&id->lock, flags);
1048         active = get_active_entry(id);
1049         curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active);
1050         va_start(ap,string);
1051         curr_event->string=string;
1052         for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1053                 curr_event->args[idx]=va_arg(ap,long);
1054         va_end(ap);
1055         debug_finish_entry(id, active, level, 1);
1056         spin_unlock_irqrestore(&id->lock, flags);
1057
1058         return active;
1059 }
1060
1061 /*
1062  * debug_init:
1063  * - is called exactly once to initialize the debug feature
1064  */
1065
1066 static int
1067 __init debug_init(void)
1068 {
1069         int rc = 0;
1070
1071         s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1072         mutex_lock(&debug_mutex);
1073         debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT,NULL);
1074         initialized = 1;
1075         mutex_unlock(&debug_mutex);
1076
1077         return rc;
1078 }
1079
1080 /*
1081  * debug_register_view:
1082  */
1083
1084 int
1085 debug_register_view(debug_info_t * id, struct debug_view *view)
1086 {
1087         int rc = 0;
1088         int i;
1089         unsigned long flags;
1090         mode_t mode;
1091         struct dentry *pde;
1092
1093         if (!id)
1094                 goto out;
1095         mode = (id->mode | S_IFREG) & ~S_IXUGO;
1096         if (!(view->prolog_proc || view->format_proc || view->header_proc))
1097                 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1098         if (!view->input_proc)
1099                 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1100         pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1101                                 id , &debug_file_ops);
1102         if (!pde){
1103                 pr_err("Registering view %s/%s failed due to out of "
1104                        "memory\n", id->name,view->name);
1105                 rc = -1;
1106                 goto out;
1107         }
1108         spin_lock_irqsave(&id->lock, flags);
1109         for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1110                 if (!id->views[i])
1111                         break;
1112         }
1113         if (i == DEBUG_MAX_VIEWS) {
1114                 pr_err("Registering view %s/%s would exceed the maximum "
1115                        "number of views %i\n", id->name, view->name, i);
1116                 debugfs_remove(pde);
1117                 rc = -1;
1118         } else {
1119                 id->views[i] = view;
1120                 id->debugfs_entries[i] = pde;
1121         }
1122         spin_unlock_irqrestore(&id->lock, flags);
1123 out:
1124         return rc;
1125 }
1126
1127 /*
1128  * debug_unregister_view:
1129  */
1130
1131 int
1132 debug_unregister_view(debug_info_t * id, struct debug_view *view)
1133 {
1134         int rc = 0;
1135         int i;
1136         unsigned long flags;
1137
1138         if (!id)
1139                 goto out;
1140         spin_lock_irqsave(&id->lock, flags);
1141         for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1142                 if (id->views[i] == view)
1143                         break;
1144         }
1145         if (i == DEBUG_MAX_VIEWS)
1146                 rc = -1;
1147         else {
1148                 debugfs_remove(id->debugfs_entries[i]);
1149                 id->views[i] = NULL;
1150         }
1151         spin_unlock_irqrestore(&id->lock, flags);
1152 out:
1153         return rc;
1154 }
1155
1156 static inline char *
1157 debug_get_user_string(const char __user *user_buf, size_t user_len)
1158 {
1159         char* buffer;
1160
1161         buffer = kmalloc(user_len + 1, GFP_KERNEL);
1162         if (!buffer)
1163                 return ERR_PTR(-ENOMEM);
1164         if (copy_from_user(buffer, user_buf, user_len) != 0) {
1165                 kfree(buffer);
1166                 return ERR_PTR(-EFAULT);
1167         }
1168         /* got the string, now strip linefeed. */
1169         if (buffer[user_len - 1] == '\n')
1170                 buffer[user_len - 1] = 0;
1171         else
1172                 buffer[user_len] = 0;
1173         return buffer;
1174 }
1175
1176 static inline int
1177 debug_get_uint(char *buf)
1178 {
1179         int rc;
1180
1181         for(; isspace(*buf); buf++);
1182         rc = simple_strtoul(buf, &buf, 10);
1183         if(*buf){
1184                 rc = -EINVAL;
1185         }
1186         return rc;
1187 }
1188
1189 /*
1190  * functions for debug-views
1191  ***********************************
1192 */
1193
1194 /*
1195  * prints out actual debug level
1196  */
1197
1198 static int
1199 debug_prolog_pages_fn(debug_info_t * id,
1200                                  struct debug_view *view, char *out_buf)
1201 {
1202         return sprintf(out_buf, "%i\n", id->pages_per_area);
1203 }
1204
1205 /*
1206  * reads new size (number of pages per debug area)
1207  */
1208
1209 static int
1210 debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
1211                         struct file *file, const char __user *user_buf,
1212                         size_t user_len, loff_t * offset)
1213 {
1214         char *str;
1215         int rc,new_pages;
1216
1217         if (user_len > 0x10000)
1218                 user_len = 0x10000;
1219         if (*offset != 0){
1220                 rc = -EPIPE;
1221                 goto out;
1222         }
1223         str = debug_get_user_string(user_buf,user_len);
1224         if(IS_ERR(str)){
1225                 rc = PTR_ERR(str);
1226                 goto out;
1227         }
1228         new_pages = debug_get_uint(str);
1229         if(new_pages < 0){
1230                 rc = -EINVAL;
1231                 goto free_str;
1232         }
1233         rc = debug_set_size(id,id->nr_areas, new_pages);
1234         if(rc != 0){
1235                 rc = -EINVAL;
1236                 goto free_str;
1237         }
1238         rc = user_len;
1239 free_str:
1240         kfree(str);
1241 out:
1242         *offset += user_len;
1243         return rc;              /* number of input characters */
1244 }
1245
1246 /*
1247  * prints out actual debug level
1248  */
1249
1250 static int
1251 debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf)
1252 {
1253         int rc = 0;
1254
1255         if(id->level == DEBUG_OFF_LEVEL) {
1256                 rc = sprintf(out_buf,"-\n");
1257         }
1258         else {
1259                 rc = sprintf(out_buf, "%i\n", id->level);
1260         }
1261         return rc;
1262 }
1263
1264 /*
1265  * reads new debug level
1266  */
1267
1268 static int
1269 debug_input_level_fn(debug_info_t * id, struct debug_view *view,
1270                         struct file *file, const char __user *user_buf,
1271                         size_t user_len, loff_t * offset)
1272 {
1273         char *str;
1274         int rc,new_level;
1275
1276         if (user_len > 0x10000)
1277                 user_len = 0x10000;
1278         if (*offset != 0){
1279                 rc = -EPIPE;
1280                 goto out;
1281         }
1282         str = debug_get_user_string(user_buf,user_len);
1283         if(IS_ERR(str)){
1284                 rc = PTR_ERR(str);
1285                 goto out;
1286         }
1287         if(str[0] == '-'){
1288                 debug_set_level(id, DEBUG_OFF_LEVEL);
1289                 rc = user_len;
1290                 goto free_str;
1291         } else {
1292                 new_level = debug_get_uint(str);
1293         }
1294         if(new_level < 0) {
1295                 pr_warning("%s is not a valid level for a debug "
1296                            "feature\n", str);
1297                 rc = -EINVAL;
1298         } else {
1299                 debug_set_level(id, new_level);
1300                 rc = user_len;
1301         }
1302 free_str:
1303         kfree(str);
1304 out:
1305         *offset += user_len;
1306         return rc;              /* number of input characters */
1307 }
1308
1309
1310 /*
1311  * flushes debug areas
1312  */
1313  
1314 static void debug_flush(debug_info_t* id, int area)
1315 {
1316         unsigned long flags;
1317         int i,j;
1318
1319         if(!id || !id->areas)
1320                 return;
1321         spin_lock_irqsave(&id->lock,flags);
1322         if(area == DEBUG_FLUSH_ALL){
1323                 id->active_area = 0;
1324                 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1325                 for (i = 0; i < id->nr_areas; i++) {
1326                         id->active_pages[i] = 0;
1327                         for(j = 0; j < id->pages_per_area; j++) {
1328                                 memset(id->areas[i][j], 0, PAGE_SIZE);
1329                         }
1330                 }
1331         } else if(area >= 0 && area < id->nr_areas) {
1332                 id->active_entries[area] = 0;
1333                 id->active_pages[area] = 0;
1334                 for(i = 0; i < id->pages_per_area; i++) {
1335                         memset(id->areas[area][i],0,PAGE_SIZE);
1336                 }
1337         }
1338         spin_unlock_irqrestore(&id->lock,flags);
1339 }
1340
1341 /*
1342  * view function: flushes debug areas 
1343  */
1344
1345 static int
1346 debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
1347                         struct file *file, const char __user *user_buf,
1348                         size_t user_len, loff_t * offset)
1349 {
1350         char input_buf[1];
1351         int rc = user_len;
1352
1353         if (user_len > 0x10000)
1354                 user_len = 0x10000;
1355         if (*offset != 0){
1356                 rc = -EPIPE;
1357                 goto out;
1358         }
1359         if (copy_from_user(input_buf, user_buf, 1)){
1360                 rc = -EFAULT;
1361                 goto out;
1362         }
1363         if(input_buf[0] == '-') { 
1364                 debug_flush(id, DEBUG_FLUSH_ALL);
1365                 goto out;
1366         }
1367         if (isdigit(input_buf[0])) {
1368                 int area = ((int) input_buf[0] - (int) '0');
1369                 debug_flush(id, area);
1370                 goto out;
1371         }
1372
1373         pr_info("Flushing debug data failed because %c is not a valid "
1374                  "area\n", input_buf[0]);
1375
1376 out:
1377         *offset += user_len;
1378         return rc;              /* number of input characters */
1379 }
1380
1381 /*
1382  * prints debug header in raw format
1383  */
1384
1385 static int
1386 debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
1387                         int area, debug_entry_t * entry, char *out_buf)
1388 {
1389         int rc;
1390
1391         rc = sizeof(debug_entry_t);
1392         memcpy(out_buf,entry,sizeof(debug_entry_t));
1393         return rc;
1394 }
1395
1396 /*
1397  * prints debug data in raw format
1398  */
1399
1400 static int
1401 debug_raw_format_fn(debug_info_t * id, struct debug_view *view,
1402                                char *out_buf, const char *in_buf)
1403 {
1404         int rc;
1405
1406         rc = id->buf_size;
1407         memcpy(out_buf, in_buf, id->buf_size);
1408         return rc;
1409 }
1410
1411 /*
1412  * prints debug data in hex/ascii format
1413  */
1414
1415 static int
1416 debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
1417                           char *out_buf, const char *in_buf)
1418 {
1419         int i, rc = 0;
1420
1421         for (i = 0; i < id->buf_size; i++) {
1422                 rc += sprintf(out_buf + rc, "%02x ",
1423                               ((unsigned char *) in_buf)[i]);
1424         }
1425         rc += sprintf(out_buf + rc, "| ");
1426         for (i = 0; i < id->buf_size; i++) {
1427                 unsigned char c = in_buf[i];
1428                 if (!isprint(c))
1429                         rc += sprintf(out_buf + rc, ".");
1430                 else
1431                         rc += sprintf(out_buf + rc, "%c", c);
1432         }
1433         rc += sprintf(out_buf + rc, "\n");
1434         return rc;
1435 }
1436
1437 /*
1438  * prints header for debug entry
1439  */
1440
1441 int
1442 debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
1443                          int area, debug_entry_t * entry, char *out_buf)
1444 {
1445         struct timespec time_spec;
1446         char *except_str;
1447         unsigned long caller;
1448         int rc = 0;
1449         unsigned int level;
1450
1451         level = entry->id.fields.level;
1452         stck_to_timespec(entry->id.stck, &time_spec);
1453
1454         if (entry->id.fields.exception)
1455                 except_str = "*";
1456         else
1457                 except_str = "-";
1458         caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN;
1459         rc += sprintf(out_buf, "%02i %011lu:%06lu %1u %1s %02i %p  ",
1460                       area, time_spec.tv_sec, time_spec.tv_nsec / 1000, level,
1461                       except_str, entry->id.fields.cpuid, (void *) caller);
1462         return rc;
1463 }
1464
1465 /*
1466  * prints debug data sprintf-formated:
1467  * debug_sprinf_event/exception calls must be used together with this view
1468  */
1469
1470 #define DEBUG_SPRINTF_MAX_ARGS 10
1471
1472 static int
1473 debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
1474                         char *out_buf, debug_sprintf_entry_t *curr_event)
1475 {
1476         int num_longs, num_used_args = 0,i, rc = 0;
1477         int index[DEBUG_SPRINTF_MAX_ARGS];
1478
1479         /* count of longs fit into one entry */
1480         num_longs = id->buf_size /  sizeof(long); 
1481
1482         if(num_longs < 1)
1483                 goto out; /* bufsize of entry too small */
1484         if(num_longs == 1) {
1485                 /* no args, we use only the string */
1486                 strcpy(out_buf, curr_event->string);
1487                 rc = strlen(curr_event->string);
1488                 goto out;
1489         }
1490
1491         /* number of arguments used for sprintf (without the format string) */
1492         num_used_args   = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1493
1494         memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1495
1496         for(i = 0; i < num_used_args; i++)
1497                 index[i] = i;
1498
1499         rc =  sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1500                 curr_event->args[index[1]], curr_event->args[index[2]],
1501                 curr_event->args[index[3]], curr_event->args[index[4]],
1502                 curr_event->args[index[5]], curr_event->args[index[6]],
1503                 curr_event->args[index[7]], curr_event->args[index[8]],
1504                 curr_event->args[index[9]]);
1505
1506 out:
1507
1508         return rc;
1509 }
1510
1511 /*
1512  * clean up module
1513  */
1514 static void __exit debug_exit(void)
1515 {
1516         debugfs_remove(debug_debugfs_root_entry);
1517         unregister_sysctl_table(s390dbf_sysctl_header);
1518         return;
1519 }
1520
1521 /*
1522  * module definitions
1523  */
1524 postcore_initcall(debug_init);
1525 module_exit(debug_exit);
1526 MODULE_LICENSE("GPL");
1527
1528 EXPORT_SYMBOL(debug_register);
1529 EXPORT_SYMBOL(debug_unregister); 
1530 EXPORT_SYMBOL(debug_set_level);
1531 EXPORT_SYMBOL(debug_stop_all);
1532 EXPORT_SYMBOL(debug_register_view);
1533 EXPORT_SYMBOL(debug_unregister_view);
1534 EXPORT_SYMBOL(debug_event_common);
1535 EXPORT_SYMBOL(debug_exception_common);
1536 EXPORT_SYMBOL(debug_hex_ascii_view);
1537 EXPORT_SYMBOL(debug_raw_view);
1538 EXPORT_SYMBOL(debug_dflt_header_fn);
1539 EXPORT_SYMBOL(debug_sprintf_view);
1540 EXPORT_SYMBOL(debug_sprintf_exception);
1541 EXPORT_SYMBOL(debug_sprintf_event);