Merge ../to-linus-stable/
[sfrench/cifs-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 #include <linux/config.h>
14 #include <linux/stddef.h>
15 #include <linux/kernel.h>
16 #include <linux/errno.h>
17 #include <linux/slab.h>
18 #include <linux/ctype.h>
19 #include <linux/sysctl.h>
20 #include <asm/uaccess.h>
21 #include <asm/semaphore.h>
22 #include <linux/module.h>
23 #include <linux/init.h>
24 #include <linux/fs.h>
25 #include <linux/debugfs.h>
26
27 #include <asm/debug.h>
28
29 #define DEBUG_PROLOG_ENTRY -1
30
31 #define ALL_AREAS 0 /* copy all debug areas */
32 #define NO_AREAS  1 /* copy no debug areas */
33
34 /* typedefs */
35
36 typedef struct file_private_info {
37         loff_t offset;                  /* offset of last read in file */
38         int    act_area;                /* number of last formated area */
39         int    act_page;                /* act page in given area */
40         int    act_entry;               /* last formated entry (offset */
41                                         /* relative to beginning of last */
42                                         /* formated page) */
43         size_t act_entry_offset;        /* up to this offset we copied */
44                                         /* in last read the last formated */
45                                         /* entry to userland */
46         char   temp_buf[2048];          /* buffer for output */
47         debug_info_t *debug_info_org;   /* original debug information */
48         debug_info_t *debug_info_snap;  /* snapshot of debug information */
49         struct debug_view *view;        /* used view of debug info */
50 } file_private_info_t;
51
52 typedef struct
53 {
54         char *string;
55         /* 
56          * This assumes that all args are converted into longs 
57          * on L/390 this is the case for all types of parameter 
58          * except of floats, and long long (32 bit) 
59          *
60          */
61         long args[0];
62 } debug_sprintf_entry_t;
63
64
65 extern void tod_to_timeval(uint64_t todval, struct timeval *xtime);
66
67 /* internal function prototyes */
68
69 static int debug_init(void);
70 static ssize_t debug_output(struct file *file, char __user *user_buf,
71                         size_t user_len, loff_t * offset);
72 static ssize_t debug_input(struct file *file, const char __user *user_buf,
73                         size_t user_len, loff_t * offset);
74 static int debug_open(struct inode *inode, struct file *file);
75 static int debug_close(struct inode *inode, struct file *file);
76 static debug_info_t*  debug_info_create(char *name, int pages_per_area,
77                         int nr_areas, int buf_size);
78 static void debug_info_get(debug_info_t *);
79 static void debug_info_put(debug_info_t *);
80 static int debug_prolog_level_fn(debug_info_t * id,
81                         struct debug_view *view, char *out_buf);
82 static int debug_input_level_fn(debug_info_t * id, struct debug_view *view,
83                         struct file *file, const char __user *user_buf,
84                         size_t user_buf_size, loff_t * offset);
85 static int debug_prolog_pages_fn(debug_info_t * id,
86                         struct debug_view *view, char *out_buf);
87 static int debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
88                         struct file *file, const char __user *user_buf,
89                         size_t user_buf_size, loff_t * offset);
90 static int debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
91                         struct file *file, const char __user *user_buf,
92                         size_t user_buf_size, loff_t * offset);
93 static int debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
94                         char *out_buf, const char *in_buf);
95 static int debug_raw_format_fn(debug_info_t * id,
96                         struct debug_view *view, char *out_buf,
97                         const char *in_buf);
98 static int debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
99                         int area, debug_entry_t * entry, char *out_buf);
100
101 static int debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
102                         char *out_buf, debug_sprintf_entry_t *curr_event);
103
104 /* globals */
105
106 struct debug_view debug_raw_view = {
107         "raw",
108         NULL,
109         &debug_raw_header_fn,
110         &debug_raw_format_fn,
111         NULL,
112         NULL
113 };
114
115 struct debug_view debug_hex_ascii_view = {
116         "hex_ascii",
117         NULL,
118         &debug_dflt_header_fn,
119         &debug_hex_ascii_format_fn,
120         NULL,
121         NULL
122 };
123
124 struct debug_view debug_level_view = {
125         "level",
126         &debug_prolog_level_fn,
127         NULL,
128         NULL,
129         &debug_input_level_fn,
130         NULL
131 };
132
133 struct debug_view debug_pages_view = {
134         "pages",
135         &debug_prolog_pages_fn,
136         NULL,
137         NULL,
138         &debug_input_pages_fn,
139         NULL
140 };
141
142 struct debug_view debug_flush_view = {
143         "flush",
144         NULL,
145         NULL,
146         NULL,
147         &debug_input_flush_fn,
148         NULL
149 };
150
151 struct debug_view debug_sprintf_view = {
152         "sprintf",
153         NULL,
154         &debug_dflt_header_fn,
155         (debug_format_proc_t*)&debug_sprintf_format_fn,
156         NULL,
157         NULL
158 };
159
160
161 unsigned int debug_feature_version = __DEBUG_FEATURE_VERSION;
162
163 /* static globals */
164
165 static debug_info_t *debug_area_first = NULL;
166 static debug_info_t *debug_area_last = NULL;
167 DECLARE_MUTEX(debug_lock);
168
169 static int initialized;
170
171 static struct file_operations debug_file_ops = {
172         .owner   = THIS_MODULE,
173         .read    = debug_output,
174         .write   = debug_input,
175         .open    = debug_open,
176         .release = debug_close,
177 };
178
179 static struct dentry *debug_debugfs_root_entry;
180
181 /* functions */
182
183 /*
184  * debug_areas_alloc
185  * - Debug areas are implemented as a threedimensonal array:
186  *   areas[areanumber][pagenumber][pageoffset]
187  */
188
189 static debug_entry_t***
190 debug_areas_alloc(int pages_per_area, int nr_areas)
191 {
192         debug_entry_t*** areas;
193         int i,j;
194
195         areas = (debug_entry_t ***) kmalloc(nr_areas *
196                                         sizeof(debug_entry_t**),
197                                         GFP_KERNEL);
198         if (!areas)
199                 goto fail_malloc_areas;
200         for (i = 0; i < nr_areas; i++) {
201                 areas[i] = (debug_entry_t**) kmalloc(pages_per_area *
202                                 sizeof(debug_entry_t*),GFP_KERNEL);
203                 if (!areas[i]) {
204                         goto fail_malloc_areas2;
205                 }
206                 for(j = 0; j < pages_per_area; j++) {
207                         areas[i][j] = (debug_entry_t*)kmalloc(PAGE_SIZE,
208                                                 GFP_KERNEL);
209                         if(!areas[i][j]) {
210                                 for(j--; j >=0 ; j--) {
211                                         kfree(areas[i][j]);
212                                 }
213                                 kfree(areas[i]);
214                                 goto fail_malloc_areas2;
215                         } else {
216                                 memset(areas[i][j],0,PAGE_SIZE);
217                         }
218                 }
219         }
220         return areas;
221
222 fail_malloc_areas2:
223         for(i--; i >= 0; i--){
224                 for(j=0; j < pages_per_area;j++){
225                         kfree(areas[i][j]);
226                 }
227                 kfree(areas[i]);
228         }
229         kfree(areas);
230 fail_malloc_areas:
231         return NULL;
232
233 }
234
235
236 /*
237  * debug_info_alloc
238  * - alloc new debug-info
239  */
240
241 static debug_info_t*
242 debug_info_alloc(char *name, int pages_per_area, int nr_areas, int buf_size,
243                 int level, int mode)
244 {
245         debug_info_t* rc;
246
247         /* alloc everything */
248
249         rc = (debug_info_t*) kmalloc(sizeof(debug_info_t), GFP_KERNEL);
250         if(!rc)
251                 goto fail_malloc_rc;
252         rc->active_entries = (int*)kmalloc(nr_areas * sizeof(int), GFP_KERNEL);
253         if(!rc->active_entries)
254                 goto fail_malloc_active_entries;
255         memset(rc->active_entries, 0, nr_areas * sizeof(int));
256         rc->active_pages = (int*)kmalloc(nr_areas * sizeof(int), GFP_KERNEL);
257         if(!rc->active_pages)
258                 goto fail_malloc_active_pages;
259         memset(rc->active_pages, 0, nr_areas * sizeof(int));
260         if((mode == ALL_AREAS) && (pages_per_area != 0)){
261                 rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
262                 if(!rc->areas)
263                         goto fail_malloc_areas;
264         } else {
265                 rc->areas = NULL;
266         }
267
268         /* initialize members */
269
270         spin_lock_init(&rc->lock);
271         rc->pages_per_area = pages_per_area;
272         rc->nr_areas       = nr_areas;
273         rc->active_area    = 0;
274         rc->level          = level;
275         rc->buf_size       = buf_size;
276         rc->entry_size     = sizeof(debug_entry_t) + buf_size;
277         strlcpy(rc->name, name, sizeof(rc->name)-1);
278         memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
279         memset(rc->debugfs_entries, 0 ,DEBUG_MAX_VIEWS *
280                 sizeof(struct dentry*));
281         atomic_set(&(rc->ref_count), 0);
282
283         return rc;
284
285 fail_malloc_areas:
286         kfree(rc->active_pages);
287 fail_malloc_active_pages:
288         kfree(rc->active_entries);
289 fail_malloc_active_entries:
290         kfree(rc);
291 fail_malloc_rc:
292         return NULL;
293 }
294
295 /*
296  * debug_areas_free
297  * - free all debug areas
298  */
299
300 static void
301 debug_areas_free(debug_info_t* db_info)
302 {
303         int i,j;
304
305         if(!db_info->areas)
306                 return;
307         for (i = 0; i < db_info->nr_areas; i++) {
308                 for(j = 0; j < db_info->pages_per_area; j++) {
309                         kfree(db_info->areas[i][j]);
310                 }
311                 kfree(db_info->areas[i]);
312         }
313         kfree(db_info->areas);
314         db_info->areas = NULL;
315 }
316
317 /*
318  * debug_info_free
319  * - free memory debug-info
320  */
321
322 static void
323 debug_info_free(debug_info_t* db_info){
324         debug_areas_free(db_info);
325         kfree(db_info->active_entries);
326         kfree(db_info->active_pages);
327         kfree(db_info);
328 }
329
330 /*
331  * debug_info_create
332  * - create new debug-info
333  */
334
335 static debug_info_t*
336 debug_info_create(char *name, int pages_per_area, int nr_areas, int buf_size)
337 {
338         debug_info_t* rc;
339
340         rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size,
341                                 DEBUG_DEFAULT_LEVEL, ALL_AREAS);
342         if(!rc) 
343                 goto out;
344
345         /* create root directory */
346         rc->debugfs_root_entry = debugfs_create_dir(rc->name,
347                                         debug_debugfs_root_entry);
348
349         /* append new element to linked list */
350         if (!debug_area_first) {
351                 /* first element in list */
352                 debug_area_first = rc;
353                 rc->prev = NULL;
354         } else {
355                 /* append element to end of list */
356                 debug_area_last->next = rc;
357                 rc->prev = debug_area_last;
358         }
359         debug_area_last = rc;
360         rc->next = NULL;
361
362         debug_info_get(rc);
363 out:
364         return rc;
365 }
366
367 /*
368  * debug_info_copy
369  * - copy debug-info
370  */
371
372 static debug_info_t*
373 debug_info_copy(debug_info_t* in, int mode)
374 {
375         int i,j;
376         debug_info_t* rc;
377
378         rc = debug_info_alloc(in->name, in->pages_per_area, in->nr_areas,
379                                 in->buf_size, in->level, mode);
380         if(!rc || (mode == NO_AREAS))
381                 goto out;
382
383         for(i = 0; i < in->nr_areas; i++){
384                 for(j = 0; j < in->pages_per_area; j++) {
385                         memcpy(rc->areas[i][j], in->areas[i][j],PAGE_SIZE);
386                 }
387         }
388 out:
389         return rc;
390 }
391
392 /*
393  * debug_info_get
394  * - increments reference count for debug-info
395  */
396
397 static void
398 debug_info_get(debug_info_t * db_info)
399 {
400         if (db_info)
401                 atomic_inc(&db_info->ref_count);
402 }
403
404 /*
405  * debug_info_put:
406  * - decreases reference count for debug-info and frees it if necessary
407  */
408
409 static void
410 debug_info_put(debug_info_t *db_info)
411 {
412         int i;
413
414         if (!db_info)
415                 return;
416         if (atomic_dec_and_test(&db_info->ref_count)) {
417                 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
418                         if (!db_info->views[i])
419                                 continue;
420                         debugfs_remove(db_info->debugfs_entries[i]);
421                 }
422                 debugfs_remove(db_info->debugfs_root_entry);
423                 if(db_info == debug_area_first)
424                         debug_area_first = db_info->next;
425                 if(db_info == debug_area_last)
426                         debug_area_last = db_info->prev;
427                 if(db_info->prev) db_info->prev->next = db_info->next;
428                 if(db_info->next) db_info->next->prev = db_info->prev;
429                 debug_info_free(db_info);
430         }
431 }
432
433 /*
434  * debug_format_entry:
435  * - format one debug entry and return size of formated data
436  */
437
438 static int
439 debug_format_entry(file_private_info_t *p_info)
440 {
441         debug_info_t *id_snap   = p_info->debug_info_snap;
442         struct debug_view *view = p_info->view;
443         debug_entry_t *act_entry;
444         size_t len = 0;
445         if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
446                 /* print prolog */
447                 if (view->prolog_proc)
448                         len += view->prolog_proc(id_snap,view,p_info->temp_buf);
449                 goto out;
450         }
451         if (!id_snap->areas) /* this is true, if we have a prolog only view */
452                 goto out;    /* or if 'pages_per_area' is 0 */
453         act_entry = (debug_entry_t *) ((char*)id_snap->areas[p_info->act_area]
454                                 [p_info->act_page] + p_info->act_entry);
455                         
456         if (act_entry->id.stck == 0LL)
457                         goto out;  /* empty entry */
458         if (view->header_proc)
459                 len += view->header_proc(id_snap, view, p_info->act_area,
460                                         act_entry, p_info->temp_buf + len);
461         if (view->format_proc)
462                 len += view->format_proc(id_snap, view, p_info->temp_buf + len,
463                                                 DEBUG_DATA(act_entry));
464 out:
465         return len;
466 }
467
468 /*
469  * debug_next_entry:
470  * - goto next entry in p_info
471  */
472
473 extern inline int
474 debug_next_entry(file_private_info_t *p_info)
475 {
476         debug_info_t *id;
477
478         id = p_info->debug_info_snap;
479         if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
480                 p_info->act_entry = 0;
481                 p_info->act_page  = 0;
482                 goto out;
483         }
484         if(!id->areas)
485                 return 1;
486         p_info->act_entry += id->entry_size;
487         /* switch to next page, if we reached the end of the page  */
488         if (p_info->act_entry > (PAGE_SIZE - id->entry_size)){
489                 /* next page */
490                 p_info->act_entry = 0;
491                 p_info->act_page += 1;
492                 if((p_info->act_page % id->pages_per_area) == 0) {
493                         /* next area */
494                         p_info->act_area++;
495                         p_info->act_page=0;
496                 }
497                 if(p_info->act_area >= id->nr_areas)
498                         return 1;
499         }
500 out:
501         return 0;       
502 }
503
504 /*
505  * debug_output:
506  * - called for user read()
507  * - copies formated debug entries to the user buffer
508  */
509
510 static ssize_t
511 debug_output(struct file *file,         /* file descriptor */
512             char __user *user_buf,      /* user buffer */
513             size_t  len,                /* length of buffer */
514             loff_t *offset)             /* offset in the file */
515 {
516         size_t count = 0;
517         size_t entry_offset;
518         file_private_info_t *p_info;
519
520         p_info = ((file_private_info_t *) file->private_data);
521         if (*offset != p_info->offset) 
522                 return -EPIPE;
523         if(p_info->act_area >= p_info->debug_info_snap->nr_areas)
524                 return 0;
525         entry_offset = p_info->act_entry_offset;
526         while(count < len){
527                 int formatted_line_size;
528                 int formatted_line_residue;
529                 int user_buf_residue;
530                 size_t copy_size;
531
532                 formatted_line_size = debug_format_entry(p_info);
533                 formatted_line_residue = formatted_line_size - entry_offset;
534                 user_buf_residue = len-count;
535                 copy_size = min(user_buf_residue, formatted_line_residue);
536                 if(copy_size){
537                         if (copy_to_user(user_buf + count, p_info->temp_buf
538                                         + entry_offset, copy_size))
539                                 return -EFAULT;
540                         count += copy_size;
541                         entry_offset += copy_size;
542                 }
543                 if(copy_size == formatted_line_residue){
544                         entry_offset = 0;
545                         if(debug_next_entry(p_info))
546                                 goto out;
547                 }
548         }
549 out:
550         p_info->offset           = *offset + count;
551         p_info->act_entry_offset = entry_offset;
552         *offset = p_info->offset;
553         return count;
554 }
555
556 /*
557  * debug_input:
558  * - called for user write()
559  * - calls input function of view
560  */
561
562 static ssize_t
563 debug_input(struct file *file, const char __user *user_buf, size_t length,
564                 loff_t *offset)
565 {
566         int rc = 0;
567         file_private_info_t *p_info;
568
569         down(&debug_lock);
570         p_info = ((file_private_info_t *) file->private_data);
571         if (p_info->view->input_proc)
572                 rc = p_info->view->input_proc(p_info->debug_info_org,
573                                               p_info->view, file, user_buf,
574                                               length, offset);
575         else
576                 rc = -EPERM;
577         up(&debug_lock);
578         return rc;              /* number of input characters */
579 }
580
581 /*
582  * debug_open:
583  * - called for user open()
584  * - copies formated output to private_data area of the file
585  *   handle
586  */
587
588 static int
589 debug_open(struct inode *inode, struct file *file)
590 {
591         int i = 0, rc = 0;
592         file_private_info_t *p_info;
593         debug_info_t *debug_info, *debug_info_snapshot;
594
595         down(&debug_lock);
596
597         /* find debug log and view */
598         debug_info = debug_area_first;
599         while(debug_info != NULL){
600                 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
601                         if (!debug_info->views[i])
602                                 continue;
603                         else if (debug_info->debugfs_entries[i] ==
604                                  file->f_dentry) {
605                                 goto found;     /* found view ! */
606                         }
607                 }
608                 debug_info = debug_info->next;
609         }
610         /* no entry found */
611         rc = -EINVAL;
612         goto out;
613
614 found:
615
616         /* Make snapshot of current debug areas to get it consistent.     */
617         /* To copy all the areas is only needed, if we have a view which  */
618         /* formats the debug areas. */
619
620         if(!debug_info->views[i]->format_proc &&
621                 !debug_info->views[i]->header_proc){
622                 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS);
623         } else {
624                 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS);
625         }
626
627         if(!debug_info_snapshot){
628                 rc = -ENOMEM;
629                 goto out;
630         }
631         p_info = (file_private_info_t *) kmalloc(sizeof(file_private_info_t),
632                                                 GFP_KERNEL);
633         if(!p_info){
634                 if(debug_info_snapshot)
635                         debug_info_free(debug_info_snapshot);
636                 rc = -ENOMEM;
637                 goto out;
638         }
639         p_info->offset = 0;
640         p_info->debug_info_snap = debug_info_snapshot;
641         p_info->debug_info_org  = debug_info;
642         p_info->view = debug_info->views[i];
643         p_info->act_area = 0;
644         p_info->act_page = 0;
645         p_info->act_entry = DEBUG_PROLOG_ENTRY;
646         p_info->act_entry_offset = 0;
647         file->private_data = p_info;
648         debug_info_get(debug_info);
649 out:
650         up(&debug_lock);
651         return rc;
652 }
653
654 /*
655  * debug_close:
656  * - called for user close()
657  * - deletes  private_data area of the file handle
658  */
659
660 static int
661 debug_close(struct inode *inode, struct file *file)
662 {
663         file_private_info_t *p_info;
664         p_info = (file_private_info_t *) file->private_data;
665         if(p_info->debug_info_snap)
666                 debug_info_free(p_info->debug_info_snap);
667         debug_info_put(p_info->debug_info_org);
668         kfree(file->private_data);
669         return 0;               /* success */
670 }
671
672 /*
673  * debug_register:
674  * - creates and initializes debug area for the caller
675  * - returns handle for debug area
676  */
677
678 debug_info_t*
679 debug_register (char *name, int pages_per_area, int nr_areas, int buf_size)
680 {
681         debug_info_t *rc = NULL;
682
683         if (!initialized)
684                 BUG();
685         down(&debug_lock);
686
687         /* create new debug_info */
688
689         rc = debug_info_create(name, pages_per_area, nr_areas, buf_size);
690         if(!rc) 
691                 goto out;
692         debug_register_view(rc, &debug_level_view);
693         debug_register_view(rc, &debug_flush_view);
694         debug_register_view(rc, &debug_pages_view);
695 out:
696         if (!rc){
697                 printk(KERN_ERR "debug: debug_register failed for %s\n",name);
698         }
699         up(&debug_lock);
700         return rc;
701 }
702
703 /*
704  * debug_unregister:
705  * - give back debug area
706  */
707
708 void
709 debug_unregister(debug_info_t * id)
710 {
711         if (!id)
712                 goto out;
713         down(&debug_lock);
714         debug_info_put(id);
715         up(&debug_lock);
716
717 out:
718         return;
719 }
720
721 /*
722  * debug_set_size:
723  * - set area size (number of pages) and number of areas
724  */
725 static int
726 debug_set_size(debug_info_t* id, int nr_areas, int pages_per_area)
727 {
728         unsigned long flags;
729         debug_entry_t *** new_areas;
730         int rc=0;
731
732         if(!id || (nr_areas <= 0) || (pages_per_area < 0))
733                 return -EINVAL;
734         if(pages_per_area > 0){
735                 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
736                 if(!new_areas) {
737                         printk(KERN_WARNING "debug: could not allocate memory "\
738                                          "for pagenumber: %i\n",pages_per_area);
739                         rc = -ENOMEM;
740                         goto out;
741                 }
742         } else {
743                 new_areas = NULL;
744         }
745         spin_lock_irqsave(&id->lock,flags);
746         debug_areas_free(id);
747         id->areas = new_areas;
748         id->nr_areas = nr_areas;
749         id->pages_per_area = pages_per_area;
750         id->active_area = 0;
751         memset(id->active_entries,0,sizeof(int)*id->nr_areas);
752         memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
753         spin_unlock_irqrestore(&id->lock,flags);
754         printk(KERN_INFO "debug: %s: set new size (%i pages)\n"\
755                          ,id->name, pages_per_area);
756 out:
757         return rc;
758 }
759
760 /*
761  * debug_set_level:
762  * - set actual debug level
763  */
764
765 void
766 debug_set_level(debug_info_t* id, int new_level)
767 {
768         unsigned long flags;
769         if(!id)
770                 return; 
771         spin_lock_irqsave(&id->lock,flags);
772         if(new_level == DEBUG_OFF_LEVEL){
773                 id->level = DEBUG_OFF_LEVEL;
774                 printk(KERN_INFO "debug: %s: switched off\n",id->name);
775         } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
776                 printk(KERN_INFO
777                         "debug: %s: level %i is out of range (%i - %i)\n",
778                         id->name, new_level, 0, DEBUG_MAX_LEVEL);
779         } else {
780                 id->level = new_level;
781         }
782         spin_unlock_irqrestore(&id->lock,flags);
783 }
784
785
786 /*
787  * proceed_active_entry:
788  * - set active entry to next in the ring buffer
789  */
790
791 extern inline void
792 proceed_active_entry(debug_info_t * id)
793 {
794         if ((id->active_entries[id->active_area] += id->entry_size)
795             > (PAGE_SIZE - id->entry_size)){
796                 id->active_entries[id->active_area] = 0;
797                 id->active_pages[id->active_area] =
798                         (id->active_pages[id->active_area] + 1) %
799                         id->pages_per_area;
800         }
801 }
802
803 /*
804  * proceed_active_area:
805  * - set active area to next in the ring buffer
806  */
807
808 extern inline void
809 proceed_active_area(debug_info_t * id)
810 {
811         id->active_area++;
812         id->active_area = id->active_area % id->nr_areas;
813 }
814
815 /*
816  * get_active_entry:
817  */
818
819 extern inline debug_entry_t*
820 get_active_entry(debug_info_t * id)
821 {
822         return (debug_entry_t *) (((char *) id->areas[id->active_area]
823                                         [id->active_pages[id->active_area]]) +
824                                         id->active_entries[id->active_area]);
825 }
826
827 /*
828  * debug_finish_entry:
829  * - set timestamp, caller address, cpu number etc.
830  */
831
832 extern inline void
833 debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level,
834                         int exception)
835 {
836         STCK(active->id.stck);
837         active->id.fields.cpuid = smp_processor_id();
838         active->caller = __builtin_return_address(0);
839         active->id.fields.exception = exception;
840         active->id.fields.level     = level;
841         proceed_active_entry(id);
842         if(exception)
843                 proceed_active_area(id);
844 }
845
846 static int debug_stoppable=1;
847 static int debug_active=1;
848
849 #define CTL_S390DBF 5677
850 #define CTL_S390DBF_STOPPABLE 5678
851 #define CTL_S390DBF_ACTIVE 5679
852
853 /*
854  * proc handler for the running debug_active sysctl
855  * always allow read, allow write only if debug_stoppable is set or
856  * if debug_active is already off
857  */
858 static int
859 s390dbf_procactive(ctl_table *table, int write, struct file *filp,
860                      void __user *buffer, size_t *lenp, loff_t *ppos)
861 {
862         if (!write || debug_stoppable || !debug_active)
863                 return proc_dointvec(table, write, filp, buffer, lenp, ppos);
864         else
865                 return 0;
866 }
867
868
869 static struct ctl_table s390dbf_table[] = {
870         {
871                 .ctl_name       = CTL_S390DBF_STOPPABLE,
872                 .procname       = "debug_stoppable",
873                 .data           = &debug_stoppable,
874                 .maxlen         = sizeof(int),
875                 .mode           = S_IRUGO | S_IWUSR,
876                 .proc_handler   = &proc_dointvec,
877                 .strategy       = &sysctl_intvec,
878         },
879          {
880                 .ctl_name       = CTL_S390DBF_ACTIVE,
881                 .procname       = "debug_active",
882                 .data           = &debug_active,
883                 .maxlen         = sizeof(int),
884                 .mode           = S_IRUGO | S_IWUSR,
885                 .proc_handler   = &s390dbf_procactive,
886                 .strategy       = &sysctl_intvec,
887         },
888         { .ctl_name = 0 }
889 };
890
891 static struct ctl_table s390dbf_dir_table[] = {
892         {
893                 .ctl_name       = CTL_S390DBF,
894                 .procname       = "s390dbf",
895                 .maxlen         = 0,
896                 .mode           = S_IRUGO | S_IXUGO,
897                 .child          = s390dbf_table,
898         },
899         { .ctl_name = 0 }
900 };
901
902 struct ctl_table_header *s390dbf_sysctl_header;
903
904 void
905 debug_stop_all(void)
906 {
907         if (debug_stoppable)
908                 debug_active = 0;
909 }
910
911
912 /*
913  * debug_event_common:
914  * - write debug entry with given size
915  */
916
917 debug_entry_t*
918 debug_event_common(debug_info_t * id, int level, const void *buf, int len)
919 {
920         unsigned long flags;
921         debug_entry_t *active;
922
923         if (!debug_active || !id->areas)
924                 return NULL;
925         spin_lock_irqsave(&id->lock, flags);
926         active = get_active_entry(id);
927         memset(DEBUG_DATA(active), 0, id->buf_size);
928         memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
929         debug_finish_entry(id, active, level, 0);
930         spin_unlock_irqrestore(&id->lock, flags);
931
932         return active;
933 }
934
935 /*
936  * debug_exception_common:
937  * - write debug entry with given size and switch to next debug area
938  */
939
940 debug_entry_t
941 *debug_exception_common(debug_info_t * id, int level, const void *buf, int len)
942 {
943         unsigned long flags;
944         debug_entry_t *active;
945
946         if (!debug_active || !id->areas)
947                 return NULL;
948         spin_lock_irqsave(&id->lock, flags);
949         active = get_active_entry(id);
950         memset(DEBUG_DATA(active), 0, id->buf_size);
951         memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
952         debug_finish_entry(id, active, level, 1);
953         spin_unlock_irqrestore(&id->lock, flags);
954
955         return active;
956 }
957
958 /*
959  * counts arguments in format string for sprintf view
960  */
961
962 extern inline int
963 debug_count_numargs(char *string)
964 {
965         int numargs=0;
966
967         while(*string) {
968                 if(*string++=='%')
969                         numargs++;
970         }
971         return(numargs);
972 }
973
974 /*
975  * debug_sprintf_event:
976  */
977
978 debug_entry_t*
979 debug_sprintf_event(debug_info_t* id, int level,char *string,...)
980 {
981         va_list   ap;
982         int numargs,idx;
983         unsigned long flags;
984         debug_sprintf_entry_t *curr_event;
985         debug_entry_t *active;
986
987         if((!id) || (level > id->level))
988                 return NULL;
989         if (!debug_active || !id->areas)
990                 return NULL;
991         numargs=debug_count_numargs(string);
992
993         spin_lock_irqsave(&id->lock, flags);
994         active = get_active_entry(id);
995         curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active);
996         va_start(ap,string);
997         curr_event->string=string;
998         for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
999                 curr_event->args[idx]=va_arg(ap,long);
1000         va_end(ap);
1001         debug_finish_entry(id, active, level, 0);
1002         spin_unlock_irqrestore(&id->lock, flags);
1003
1004         return active;
1005 }
1006
1007 /*
1008  * debug_sprintf_exception:
1009  */
1010
1011 debug_entry_t*
1012 debug_sprintf_exception(debug_info_t* id, int level,char *string,...)
1013 {
1014         va_list   ap;
1015         int numargs,idx;
1016         unsigned long flags;
1017         debug_sprintf_entry_t *curr_event;
1018         debug_entry_t *active;
1019
1020         if((!id) || (level > id->level))
1021                 return NULL;
1022         if (!debug_active || !id->areas)
1023                 return NULL;
1024
1025         numargs=debug_count_numargs(string);
1026
1027         spin_lock_irqsave(&id->lock, flags);
1028         active = get_active_entry(id);
1029         curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active);
1030         va_start(ap,string);
1031         curr_event->string=string;
1032         for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1033                 curr_event->args[idx]=va_arg(ap,long);
1034         va_end(ap);
1035         debug_finish_entry(id, active, level, 1);
1036         spin_unlock_irqrestore(&id->lock, flags);
1037
1038         return active;
1039 }
1040
1041 /*
1042  * debug_init:
1043  * - is called exactly once to initialize the debug feature
1044  */
1045
1046 static int
1047 __init debug_init(void)
1048 {
1049         int rc = 0;
1050
1051         s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table, 1);
1052         down(&debug_lock);
1053         debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT,NULL);
1054         printk(KERN_INFO "debug: Initialization complete\n");
1055         initialized = 1;
1056         up(&debug_lock);
1057
1058         return rc;
1059 }
1060
1061 /*
1062  * debug_register_view:
1063  */
1064
1065 int
1066 debug_register_view(debug_info_t * id, struct debug_view *view)
1067 {
1068         int rc = 0;
1069         int i;
1070         unsigned long flags;
1071         mode_t mode = S_IFREG;
1072         struct dentry *pde;
1073
1074         if (!id)
1075                 goto out;
1076         if (view->prolog_proc || view->format_proc || view->header_proc)
1077                 mode |= S_IRUSR;
1078         if (view->input_proc)
1079                 mode |= S_IWUSR;
1080         pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1081                                 NULL, &debug_file_ops);
1082         if (!pde){
1083                 printk(KERN_WARNING "debug: debugfs_create_file() failed!"\
1084                         " Cannot register view %s/%s\n", id->name,view->name);
1085                 rc = -1;
1086                 goto out;
1087         }
1088         spin_lock_irqsave(&id->lock, flags);
1089         for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1090                 if (!id->views[i])
1091                         break;
1092         }
1093         if (i == DEBUG_MAX_VIEWS) {
1094                 printk(KERN_WARNING "debug: cannot register view %s/%s\n",
1095                         id->name,view->name);
1096                 printk(KERN_WARNING 
1097                         "debug: maximum number of views reached (%i)!\n", i);
1098                 debugfs_remove(pde);
1099                 rc = -1;
1100         } else {
1101                 id->views[i] = view;
1102                 id->debugfs_entries[i] = pde;
1103         }
1104         spin_unlock_irqrestore(&id->lock, flags);
1105 out:
1106         return rc;
1107 }
1108
1109 /*
1110  * debug_unregister_view:
1111  */
1112
1113 int
1114 debug_unregister_view(debug_info_t * id, struct debug_view *view)
1115 {
1116         int rc = 0;
1117         int i;
1118         unsigned long flags;
1119
1120         if (!id)
1121                 goto out;
1122         spin_lock_irqsave(&id->lock, flags);
1123         for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1124                 if (id->views[i] == view)
1125                         break;
1126         }
1127         if (i == DEBUG_MAX_VIEWS)
1128                 rc = -1;
1129         else {
1130                 debugfs_remove(id->debugfs_entries[i]);
1131                 id->views[i] = NULL;
1132                 rc = 0;
1133         }
1134         spin_unlock_irqrestore(&id->lock, flags);
1135 out:
1136         return rc;
1137 }
1138
1139 static inline char *
1140 debug_get_user_string(const char __user *user_buf, size_t user_len)
1141 {
1142         char* buffer;
1143
1144         buffer = kmalloc(user_len + 1, GFP_KERNEL);
1145         if (!buffer)
1146                 return ERR_PTR(-ENOMEM);
1147         if (copy_from_user(buffer, user_buf, user_len) != 0) {
1148                 kfree(buffer);
1149                 return ERR_PTR(-EFAULT);
1150         }
1151         /* got the string, now strip linefeed. */
1152         if (buffer[user_len - 1] == '\n')
1153                 buffer[user_len - 1] = 0;
1154         else
1155                 buffer[user_len] = 0;
1156         return buffer;
1157 }
1158
1159 static inline int
1160 debug_get_uint(char *buf)
1161 {
1162         int rc;
1163
1164         for(; isspace(*buf); buf++);
1165         rc = simple_strtoul(buf, &buf, 10);
1166         if(*buf){
1167                 printk("debug: no integer specified!\n");
1168                 rc = -EINVAL;
1169         }
1170         return rc;
1171 }
1172
1173 /*
1174  * functions for debug-views
1175  ***********************************
1176 */
1177
1178 /*
1179  * prints out actual debug level
1180  */
1181
1182 static int
1183 debug_prolog_pages_fn(debug_info_t * id,
1184                                  struct debug_view *view, char *out_buf)
1185 {
1186         return sprintf(out_buf, "%i\n", id->pages_per_area);
1187 }
1188
1189 /*
1190  * reads new size (number of pages per debug area)
1191  */
1192
1193 static int
1194 debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
1195                         struct file *file, const char __user *user_buf,
1196                         size_t user_len, loff_t * offset)
1197 {
1198         char *str;
1199         int rc,new_pages;
1200
1201         if (user_len > 0x10000)
1202                 user_len = 0x10000;
1203         if (*offset != 0){
1204                 rc = -EPIPE;
1205                 goto out;
1206         }
1207         str = debug_get_user_string(user_buf,user_len);
1208         if(IS_ERR(str)){
1209                 rc = PTR_ERR(str);
1210                 goto out;
1211         }
1212         new_pages = debug_get_uint(str);
1213         if(new_pages < 0){
1214                 rc = -EINVAL;
1215                 goto free_str;
1216         }
1217         rc = debug_set_size(id,id->nr_areas, new_pages);
1218         if(rc != 0){
1219                 rc = -EINVAL;
1220                 goto free_str;
1221         }
1222         rc = user_len;
1223 free_str:
1224         kfree(str);
1225 out:
1226         *offset += user_len;
1227         return rc;              /* number of input characters */
1228 }
1229
1230 /*
1231  * prints out actual debug level
1232  */
1233
1234 static int
1235 debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf)
1236 {
1237         int rc = 0;
1238
1239         if(id->level == DEBUG_OFF_LEVEL) {
1240                 rc = sprintf(out_buf,"-\n");
1241         }
1242         else {
1243                 rc = sprintf(out_buf, "%i\n", id->level);
1244         }
1245         return rc;
1246 }
1247
1248 /*
1249  * reads new debug level
1250  */
1251
1252 static int
1253 debug_input_level_fn(debug_info_t * id, struct debug_view *view,
1254                         struct file *file, const char __user *user_buf,
1255                         size_t user_len, loff_t * offset)
1256 {
1257         char *str;
1258         int rc,new_level;
1259
1260         if (user_len > 0x10000)
1261                 user_len = 0x10000;
1262         if (*offset != 0){
1263                 rc = -EPIPE;
1264                 goto out;
1265         }
1266         str = debug_get_user_string(user_buf,user_len);
1267         if(IS_ERR(str)){
1268                 rc = PTR_ERR(str);
1269                 goto out;
1270         }
1271         if(str[0] == '-'){
1272                 debug_set_level(id, DEBUG_OFF_LEVEL);
1273                 rc = user_len;
1274                 goto free_str;
1275         } else {
1276                 new_level = debug_get_uint(str);
1277         }
1278         if(new_level < 0) {
1279                 printk(KERN_INFO "debug: level `%s` is not valid\n", str);
1280                 rc = -EINVAL;
1281         } else {
1282                 debug_set_level(id, new_level);
1283                 rc = user_len;
1284         }
1285 free_str:
1286         kfree(str);
1287 out:
1288         *offset += user_len;
1289         return rc;              /* number of input characters */
1290 }
1291
1292
1293 /*
1294  * flushes debug areas
1295  */
1296  
1297 void
1298 debug_flush(debug_info_t* id, int area)
1299 {
1300         unsigned long flags;
1301         int i,j;
1302
1303         if(!id || !id->areas)
1304                 return;
1305         spin_lock_irqsave(&id->lock,flags);
1306         if(area == DEBUG_FLUSH_ALL){
1307                 id->active_area = 0;
1308                 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1309                 for (i = 0; i < id->nr_areas; i++) {
1310                         id->active_pages[i] = 0;
1311                         for(j = 0; j < id->pages_per_area; j++) {
1312                                 memset(id->areas[i][j], 0, PAGE_SIZE);
1313                         }
1314                 }
1315                 printk(KERN_INFO "debug: %s: all areas flushed\n",id->name);
1316         } else if(area >= 0 && area < id->nr_areas) {
1317                 id->active_entries[area] = 0;
1318                 id->active_pages[area] = 0;
1319                 for(i = 0; i < id->pages_per_area; i++) {
1320                         memset(id->areas[area][i],0,PAGE_SIZE);
1321                 }
1322                 printk(KERN_INFO "debug: %s: area %i has been flushed\n",
1323                         id->name, area);
1324         } else {
1325                 printk(KERN_INFO
1326                       "debug: %s: area %i cannot be flushed (range: %i - %i)\n",
1327                         id->name, area, 0, id->nr_areas-1);
1328         }
1329         spin_unlock_irqrestore(&id->lock,flags);
1330 }
1331
1332 /*
1333  * view function: flushes debug areas 
1334  */
1335
1336 static int
1337 debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
1338                         struct file *file, const char __user *user_buf,
1339                         size_t user_len, loff_t * offset)
1340 {
1341         char input_buf[1];
1342         int rc = user_len;
1343
1344         if (user_len > 0x10000)
1345                 user_len = 0x10000;
1346         if (*offset != 0){
1347                 rc = -EPIPE;
1348                 goto out;
1349         }
1350         if (copy_from_user(input_buf, user_buf, 1)){
1351                 rc = -EFAULT;
1352                 goto out;
1353         }
1354         if(input_buf[0] == '-') { 
1355                 debug_flush(id, DEBUG_FLUSH_ALL);
1356                 goto out;
1357         }
1358         if (isdigit(input_buf[0])) {
1359                 int area = ((int) input_buf[0] - (int) '0');
1360                 debug_flush(id, area);
1361                 goto out;
1362         }
1363
1364         printk(KERN_INFO "debug: area `%c` is not valid\n", input_buf[0]);
1365
1366 out:
1367         *offset += user_len;
1368         return rc;              /* number of input characters */
1369 }
1370
1371 /*
1372  * prints debug header in raw format
1373  */
1374
1375 static int
1376 debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
1377                         int area, debug_entry_t * entry, char *out_buf)
1378 {
1379         int rc;
1380
1381         rc = sizeof(debug_entry_t);
1382         memcpy(out_buf,entry,sizeof(debug_entry_t));
1383         return rc;
1384 }
1385
1386 /*
1387  * prints debug data in raw format
1388  */
1389
1390 static int
1391 debug_raw_format_fn(debug_info_t * id, struct debug_view *view,
1392                                char *out_buf, const char *in_buf)
1393 {
1394         int rc;
1395
1396         rc = id->buf_size;
1397         memcpy(out_buf, in_buf, id->buf_size);
1398         return rc;
1399 }
1400
1401 /*
1402  * prints debug data in hex/ascii format
1403  */
1404
1405 static int
1406 debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
1407                           char *out_buf, const char *in_buf)
1408 {
1409         int i, rc = 0;
1410
1411         for (i = 0; i < id->buf_size; i++) {
1412                 rc += sprintf(out_buf + rc, "%02x ",
1413                               ((unsigned char *) in_buf)[i]);
1414         }
1415         rc += sprintf(out_buf + rc, "| ");
1416         for (i = 0; i < id->buf_size; i++) {
1417                 unsigned char c = in_buf[i];
1418                 if (!isprint(c))
1419                         rc += sprintf(out_buf + rc, ".");
1420                 else
1421                         rc += sprintf(out_buf + rc, "%c", c);
1422         }
1423         rc += sprintf(out_buf + rc, "\n");
1424         return rc;
1425 }
1426
1427 /*
1428  * prints header for debug entry
1429  */
1430
1431 int
1432 debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
1433                          int area, debug_entry_t * entry, char *out_buf)
1434 {
1435         struct timeval time_val;
1436         unsigned long long time;
1437         char *except_str;
1438         unsigned long caller;
1439         int rc = 0;
1440         unsigned int level;
1441
1442         level = entry->id.fields.level;
1443         time = entry->id.stck;
1444         /* adjust todclock to 1970 */
1445         time -= 0x8126d60e46000000LL - (0x3c26700LL * 1000000 * 4096);
1446         tod_to_timeval(time, &time_val);
1447
1448         if (entry->id.fields.exception)
1449                 except_str = "*";
1450         else
1451                 except_str = "-";
1452         caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN;
1453         rc += sprintf(out_buf, "%02i %011lu:%06lu %1u %1s %02i %p  ",
1454                       area, time_val.tv_sec, time_val.tv_usec, level,
1455                       except_str, entry->id.fields.cpuid, (void *) caller);
1456         return rc;
1457 }
1458
1459 /*
1460  * prints debug data sprintf-formated:
1461  * debug_sprinf_event/exception calls must be used together with this view
1462  */
1463
1464 #define DEBUG_SPRINTF_MAX_ARGS 10
1465
1466 static int
1467 debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
1468                         char *out_buf, debug_sprintf_entry_t *curr_event)
1469 {
1470         int num_longs, num_used_args = 0,i, rc = 0;
1471         int index[DEBUG_SPRINTF_MAX_ARGS];
1472
1473         /* count of longs fit into one entry */
1474         num_longs = id->buf_size /  sizeof(long); 
1475
1476         if(num_longs < 1)
1477                 goto out; /* bufsize of entry too small */
1478         if(num_longs == 1) {
1479                 /* no args, we use only the string */
1480                 strcpy(out_buf, curr_event->string);
1481                 rc = strlen(curr_event->string);
1482                 goto out;
1483         }
1484
1485         /* number of arguments used for sprintf (without the format string) */
1486         num_used_args   = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1487
1488         memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1489
1490         for(i = 0; i < num_used_args; i++)
1491                 index[i] = i;
1492
1493         rc =  sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1494                 curr_event->args[index[1]], curr_event->args[index[2]],
1495                 curr_event->args[index[3]], curr_event->args[index[4]],
1496                 curr_event->args[index[5]], curr_event->args[index[6]],
1497                 curr_event->args[index[7]], curr_event->args[index[8]],
1498                 curr_event->args[index[9]]);
1499
1500 out:
1501
1502         return rc;
1503 }
1504
1505 /*
1506  * clean up module
1507  */
1508 void
1509 __exit debug_exit(void)
1510 {
1511         debugfs_remove(debug_debugfs_root_entry);
1512         unregister_sysctl_table(s390dbf_sysctl_header);
1513         return;
1514 }
1515
1516 /*
1517  * module definitions
1518  */
1519 postcore_initcall(debug_init);
1520 module_exit(debug_exit);
1521 MODULE_LICENSE("GPL");
1522
1523 EXPORT_SYMBOL(debug_register);
1524 EXPORT_SYMBOL(debug_unregister); 
1525 EXPORT_SYMBOL(debug_set_level);
1526 EXPORT_SYMBOL(debug_stop_all);
1527 EXPORT_SYMBOL(debug_register_view);
1528 EXPORT_SYMBOL(debug_unregister_view);
1529 EXPORT_SYMBOL(debug_event_common);
1530 EXPORT_SYMBOL(debug_exception_common);
1531 EXPORT_SYMBOL(debug_hex_ascii_view);
1532 EXPORT_SYMBOL(debug_raw_view);
1533 EXPORT_SYMBOL(debug_dflt_header_fn);
1534 EXPORT_SYMBOL(debug_sprintf_view);
1535 EXPORT_SYMBOL(debug_sprintf_exception);
1536 EXPORT_SYMBOL(debug_sprintf_event);