Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff
[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 #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 timespec *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] = kzalloc(PAGE_SIZE, GFP_KERNEL);
208                         if(!areas[i][j]) {
209                                 for(j--; j >=0 ; j--) {
210                                         kfree(areas[i][j]);
211                                 }
212                                 kfree(areas[i]);
213                                 goto fail_malloc_areas2;
214                         }
215                 }
216         }
217         return areas;
218
219 fail_malloc_areas2:
220         for(i--; i >= 0; i--){
221                 for(j=0; j < pages_per_area;j++){
222                         kfree(areas[i][j]);
223                 }
224                 kfree(areas[i]);
225         }
226         kfree(areas);
227 fail_malloc_areas:
228         return NULL;
229
230 }
231
232
233 /*
234  * debug_info_alloc
235  * - alloc new debug-info
236  */
237
238 static debug_info_t*
239 debug_info_alloc(char *name, int pages_per_area, int nr_areas, int buf_size,
240                 int level, int mode)
241 {
242         debug_info_t* rc;
243
244         /* alloc everything */
245
246         rc = (debug_info_t*) kmalloc(sizeof(debug_info_t), GFP_KERNEL);
247         if(!rc)
248                 goto fail_malloc_rc;
249         rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
250         if(!rc->active_entries)
251                 goto fail_malloc_active_entries;
252         rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
253         if(!rc->active_pages)
254                 goto fail_malloc_active_pages;
255         if((mode == ALL_AREAS) && (pages_per_area != 0)){
256                 rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
257                 if(!rc->areas)
258                         goto fail_malloc_areas;
259         } else {
260                 rc->areas = NULL;
261         }
262
263         /* initialize members */
264
265         spin_lock_init(&rc->lock);
266         rc->pages_per_area = pages_per_area;
267         rc->nr_areas       = nr_areas;
268         rc->active_area    = 0;
269         rc->level          = level;
270         rc->buf_size       = buf_size;
271         rc->entry_size     = sizeof(debug_entry_t) + buf_size;
272         strlcpy(rc->name, name, sizeof(rc->name)-1);
273         memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
274         memset(rc->debugfs_entries, 0 ,DEBUG_MAX_VIEWS *
275                 sizeof(struct dentry*));
276         atomic_set(&(rc->ref_count), 0);
277
278         return rc;
279
280 fail_malloc_areas:
281         kfree(rc->active_pages);
282 fail_malloc_active_pages:
283         kfree(rc->active_entries);
284 fail_malloc_active_entries:
285         kfree(rc);
286 fail_malloc_rc:
287         return NULL;
288 }
289
290 /*
291  * debug_areas_free
292  * - free all debug areas
293  */
294
295 static void
296 debug_areas_free(debug_info_t* db_info)
297 {
298         int i,j;
299
300         if(!db_info->areas)
301                 return;
302         for (i = 0; i < db_info->nr_areas; i++) {
303                 for(j = 0; j < db_info->pages_per_area; j++) {
304                         kfree(db_info->areas[i][j]);
305                 }
306                 kfree(db_info->areas[i]);
307         }
308         kfree(db_info->areas);
309         db_info->areas = NULL;
310 }
311
312 /*
313  * debug_info_free
314  * - free memory debug-info
315  */
316
317 static void
318 debug_info_free(debug_info_t* db_info){
319         debug_areas_free(db_info);
320         kfree(db_info->active_entries);
321         kfree(db_info->active_pages);
322         kfree(db_info);
323 }
324
325 /*
326  * debug_info_create
327  * - create new debug-info
328  */
329
330 static debug_info_t*
331 debug_info_create(char *name, int pages_per_area, int nr_areas, int buf_size)
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         /* create root directory */
341         rc->debugfs_root_entry = debugfs_create_dir(rc->name,
342                                         debug_debugfs_root_entry);
343
344         /* append new element to linked list */
345         if (!debug_area_first) {
346                 /* first element in list */
347                 debug_area_first = rc;
348                 rc->prev = NULL;
349         } else {
350                 /* append element to end of list */
351                 debug_area_last->next = rc;
352                 rc->prev = debug_area_last;
353         }
354         debug_area_last = rc;
355         rc->next = NULL;
356
357         debug_info_get(rc);
358 out:
359         return rc;
360 }
361
362 /*
363  * debug_info_copy
364  * - copy debug-info
365  */
366
367 static debug_info_t*
368 debug_info_copy(debug_info_t* in, int mode)
369 {
370         int i,j;
371         debug_info_t* rc;
372         unsigned long flags;
373
374         /* get a consistent copy of the debug areas */
375         do {
376                 rc = debug_info_alloc(in->name, in->pages_per_area,
377                         in->nr_areas, in->buf_size, in->level, mode);
378                 spin_lock_irqsave(&in->lock, flags);
379                 if(!rc)
380                         goto out;
381                 /* has something changed in the meantime ? */
382                 if((rc->pages_per_area == in->pages_per_area) &&
383                    (rc->nr_areas == in->nr_areas)) {
384                         break;
385                 }
386                 spin_unlock_irqrestore(&in->lock, flags);
387                 debug_info_free(rc);
388         } while (1);
389
390         if(!rc || (mode == NO_AREAS))
391                 goto out;
392
393         for(i = 0; i < in->nr_areas; i++){
394                 for(j = 0; j < in->pages_per_area; j++) {
395                         memcpy(rc->areas[i][j], in->areas[i][j],PAGE_SIZE);
396                 }
397         }
398 out:
399         spin_unlock_irqrestore(&in->lock, flags);
400         return rc;
401 }
402
403 /*
404  * debug_info_get
405  * - increments reference count for debug-info
406  */
407
408 static void
409 debug_info_get(debug_info_t * db_info)
410 {
411         if (db_info)
412                 atomic_inc(&db_info->ref_count);
413 }
414
415 /*
416  * debug_info_put:
417  * - decreases reference count for debug-info and frees it if necessary
418  */
419
420 static void
421 debug_info_put(debug_info_t *db_info)
422 {
423         int i;
424
425         if (!db_info)
426                 return;
427         if (atomic_dec_and_test(&db_info->ref_count)) {
428                 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
429                         if (!db_info->views[i])
430                                 continue;
431                         debugfs_remove(db_info->debugfs_entries[i]);
432                 }
433                 debugfs_remove(db_info->debugfs_root_entry);
434                 if(db_info == debug_area_first)
435                         debug_area_first = db_info->next;
436                 if(db_info == debug_area_last)
437                         debug_area_last = db_info->prev;
438                 if(db_info->prev) db_info->prev->next = db_info->next;
439                 if(db_info->next) db_info->next->prev = db_info->prev;
440                 debug_info_free(db_info);
441         }
442 }
443
444 /*
445  * debug_format_entry:
446  * - format one debug entry and return size of formated data
447  */
448
449 static int
450 debug_format_entry(file_private_info_t *p_info)
451 {
452         debug_info_t *id_snap   = p_info->debug_info_snap;
453         struct debug_view *view = p_info->view;
454         debug_entry_t *act_entry;
455         size_t len = 0;
456         if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
457                 /* print prolog */
458                 if (view->prolog_proc)
459                         len += view->prolog_proc(id_snap,view,p_info->temp_buf);
460                 goto out;
461         }
462         if (!id_snap->areas) /* this is true, if we have a prolog only view */
463                 goto out;    /* or if 'pages_per_area' is 0 */
464         act_entry = (debug_entry_t *) ((char*)id_snap->areas[p_info->act_area]
465                                 [p_info->act_page] + p_info->act_entry);
466                         
467         if (act_entry->id.stck == 0LL)
468                         goto out;  /* empty entry */
469         if (view->header_proc)
470                 len += view->header_proc(id_snap, view, p_info->act_area,
471                                         act_entry, p_info->temp_buf + len);
472         if (view->format_proc)
473                 len += view->format_proc(id_snap, view, p_info->temp_buf + len,
474                                                 DEBUG_DATA(act_entry));
475 out:
476         return len;
477 }
478
479 /*
480  * debug_next_entry:
481  * - goto next entry in p_info
482  */
483
484 static inline int
485 debug_next_entry(file_private_info_t *p_info)
486 {
487         debug_info_t *id;
488
489         id = p_info->debug_info_snap;
490         if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
491                 p_info->act_entry = 0;
492                 p_info->act_page  = 0;
493                 goto out;
494         }
495         if(!id->areas)
496                 return 1;
497         p_info->act_entry += id->entry_size;
498         /* switch to next page, if we reached the end of the page  */
499         if (p_info->act_entry > (PAGE_SIZE - id->entry_size)){
500                 /* next page */
501                 p_info->act_entry = 0;
502                 p_info->act_page += 1;
503                 if((p_info->act_page % id->pages_per_area) == 0) {
504                         /* next area */
505                         p_info->act_area++;
506                         p_info->act_page=0;
507                 }
508                 if(p_info->act_area >= id->nr_areas)
509                         return 1;
510         }
511 out:
512         return 0;       
513 }
514
515 /*
516  * debug_output:
517  * - called for user read()
518  * - copies formated debug entries to the user buffer
519  */
520
521 static ssize_t
522 debug_output(struct file *file,         /* file descriptor */
523             char __user *user_buf,      /* user buffer */
524             size_t  len,                /* length of buffer */
525             loff_t *offset)             /* offset in the file */
526 {
527         size_t count = 0;
528         size_t entry_offset;
529         file_private_info_t *p_info;
530
531         p_info = ((file_private_info_t *) file->private_data);
532         if (*offset != p_info->offset) 
533                 return -EPIPE;
534         if(p_info->act_area >= p_info->debug_info_snap->nr_areas)
535                 return 0;
536         entry_offset = p_info->act_entry_offset;
537         while(count < len){
538                 int formatted_line_size;
539                 int formatted_line_residue;
540                 int user_buf_residue;
541                 size_t copy_size;
542
543                 formatted_line_size = debug_format_entry(p_info);
544                 formatted_line_residue = formatted_line_size - entry_offset;
545                 user_buf_residue = len-count;
546                 copy_size = min(user_buf_residue, formatted_line_residue);
547                 if(copy_size){
548                         if (copy_to_user(user_buf + count, p_info->temp_buf
549                                         + entry_offset, copy_size))
550                                 return -EFAULT;
551                         count += copy_size;
552                         entry_offset += copy_size;
553                 }
554                 if(copy_size == formatted_line_residue){
555                         entry_offset = 0;
556                         if(debug_next_entry(p_info))
557                                 goto out;
558                 }
559         }
560 out:
561         p_info->offset           = *offset + count;
562         p_info->act_entry_offset = entry_offset;
563         *offset = p_info->offset;
564         return count;
565 }
566
567 /*
568  * debug_input:
569  * - called for user write()
570  * - calls input function of view
571  */
572
573 static ssize_t
574 debug_input(struct file *file, const char __user *user_buf, size_t length,
575                 loff_t *offset)
576 {
577         int rc = 0;
578         file_private_info_t *p_info;
579
580         down(&debug_lock);
581         p_info = ((file_private_info_t *) file->private_data);
582         if (p_info->view->input_proc)
583                 rc = p_info->view->input_proc(p_info->debug_info_org,
584                                               p_info->view, file, user_buf,
585                                               length, offset);
586         else
587                 rc = -EPERM;
588         up(&debug_lock);
589         return rc;              /* number of input characters */
590 }
591
592 /*
593  * debug_open:
594  * - called for user open()
595  * - copies formated output to private_data area of the file
596  *   handle
597  */
598
599 static int
600 debug_open(struct inode *inode, struct file *file)
601 {
602         int i = 0, rc = 0;
603         file_private_info_t *p_info;
604         debug_info_t *debug_info, *debug_info_snapshot;
605
606         down(&debug_lock);
607         debug_info = (struct debug_info*)file->f_dentry->d_inode->u.generic_ip;
608         /* find debug view */
609         for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
610                 if (!debug_info->views[i])
611                         continue;
612                 else if (debug_info->debugfs_entries[i] ==
613                          file->f_dentry) {
614                         goto found;     /* found view ! */
615                 }
616         }
617         /* no entry found */
618         rc = -EINVAL;
619         goto out;
620
621 found:
622
623         /* Make snapshot of current debug areas to get it consistent.     */
624         /* To copy all the areas is only needed, if we have a view which  */
625         /* formats the debug areas. */
626
627         if(!debug_info->views[i]->format_proc &&
628                 !debug_info->views[i]->header_proc){
629                 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS);
630         } else {
631                 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS);
632         }
633
634         if(!debug_info_snapshot){
635                 rc = -ENOMEM;
636                 goto out;
637         }
638         p_info = (file_private_info_t *) kmalloc(sizeof(file_private_info_t),
639                                                 GFP_KERNEL);
640         if(!p_info){
641                 if(debug_info_snapshot)
642                         debug_info_free(debug_info_snapshot);
643                 rc = -ENOMEM;
644                 goto out;
645         }
646         p_info->offset = 0;
647         p_info->debug_info_snap = debug_info_snapshot;
648         p_info->debug_info_org  = debug_info;
649         p_info->view = debug_info->views[i];
650         p_info->act_area = 0;
651         p_info->act_page = 0;
652         p_info->act_entry = DEBUG_PROLOG_ENTRY;
653         p_info->act_entry_offset = 0;
654         file->private_data = p_info;
655         debug_info_get(debug_info);
656 out:
657         up(&debug_lock);
658         return rc;
659 }
660
661 /*
662  * debug_close:
663  * - called for user close()
664  * - deletes  private_data area of the file handle
665  */
666
667 static int
668 debug_close(struct inode *inode, struct file *file)
669 {
670         file_private_info_t *p_info;
671         p_info = (file_private_info_t *) file->private_data;
672         if(p_info->debug_info_snap)
673                 debug_info_free(p_info->debug_info_snap);
674         debug_info_put(p_info->debug_info_org);
675         kfree(file->private_data);
676         return 0;               /* success */
677 }
678
679 /*
680  * debug_register:
681  * - creates and initializes debug area for the caller
682  * - returns handle for debug area
683  */
684
685 debug_info_t*
686 debug_register (char *name, int pages_per_area, int nr_areas, int buf_size)
687 {
688         debug_info_t *rc = NULL;
689
690         if (!initialized)
691                 BUG();
692         down(&debug_lock);
693
694         /* create new debug_info */
695
696         rc = debug_info_create(name, pages_per_area, nr_areas, buf_size);
697         if(!rc) 
698                 goto out;
699         debug_register_view(rc, &debug_level_view);
700         debug_register_view(rc, &debug_flush_view);
701         debug_register_view(rc, &debug_pages_view);
702 out:
703         if (!rc){
704                 printk(KERN_ERR "debug: debug_register failed for %s\n",name);
705         }
706         up(&debug_lock);
707         return rc;
708 }
709
710 /*
711  * debug_unregister:
712  * - give back debug area
713  */
714
715 void
716 debug_unregister(debug_info_t * id)
717 {
718         if (!id)
719                 goto out;
720         down(&debug_lock);
721         debug_info_put(id);
722         up(&debug_lock);
723
724 out:
725         return;
726 }
727
728 /*
729  * debug_set_size:
730  * - set area size (number of pages) and number of areas
731  */
732 static int
733 debug_set_size(debug_info_t* id, int nr_areas, int pages_per_area)
734 {
735         unsigned long flags;
736         debug_entry_t *** new_areas;
737         int rc=0;
738
739         if(!id || (nr_areas <= 0) || (pages_per_area < 0))
740                 return -EINVAL;
741         if(pages_per_area > 0){
742                 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
743                 if(!new_areas) {
744                         printk(KERN_WARNING "debug: could not allocate memory "\
745                                          "for pagenumber: %i\n",pages_per_area);
746                         rc = -ENOMEM;
747                         goto out;
748                 }
749         } else {
750                 new_areas = NULL;
751         }
752         spin_lock_irqsave(&id->lock,flags);
753         debug_areas_free(id);
754         id->areas = new_areas;
755         id->nr_areas = nr_areas;
756         id->pages_per_area = pages_per_area;
757         id->active_area = 0;
758         memset(id->active_entries,0,sizeof(int)*id->nr_areas);
759         memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
760         spin_unlock_irqrestore(&id->lock,flags);
761         printk(KERN_INFO "debug: %s: set new size (%i pages)\n"\
762                          ,id->name, pages_per_area);
763 out:
764         return rc;
765 }
766
767 /*
768  * debug_set_level:
769  * - set actual debug level
770  */
771
772 void
773 debug_set_level(debug_info_t* id, int new_level)
774 {
775         unsigned long flags;
776         if(!id)
777                 return; 
778         spin_lock_irqsave(&id->lock,flags);
779         if(new_level == DEBUG_OFF_LEVEL){
780                 id->level = DEBUG_OFF_LEVEL;
781                 printk(KERN_INFO "debug: %s: switched off\n",id->name);
782         } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
783                 printk(KERN_INFO
784                         "debug: %s: level %i is out of range (%i - %i)\n",
785                         id->name, new_level, 0, DEBUG_MAX_LEVEL);
786         } else {
787                 id->level = new_level;
788         }
789         spin_unlock_irqrestore(&id->lock,flags);
790 }
791
792
793 /*
794  * proceed_active_entry:
795  * - set active entry to next in the ring buffer
796  */
797
798 static inline void
799 proceed_active_entry(debug_info_t * id)
800 {
801         if ((id->active_entries[id->active_area] += id->entry_size)
802             > (PAGE_SIZE - id->entry_size)){
803                 id->active_entries[id->active_area] = 0;
804                 id->active_pages[id->active_area] =
805                         (id->active_pages[id->active_area] + 1) %
806                         id->pages_per_area;
807         }
808 }
809
810 /*
811  * proceed_active_area:
812  * - set active area to next in the ring buffer
813  */
814
815 static inline void
816 proceed_active_area(debug_info_t * id)
817 {
818         id->active_area++;
819         id->active_area = id->active_area % id->nr_areas;
820 }
821
822 /*
823  * get_active_entry:
824  */
825
826 static inline debug_entry_t*
827 get_active_entry(debug_info_t * id)
828 {
829         return (debug_entry_t *) (((char *) id->areas[id->active_area]
830                                         [id->active_pages[id->active_area]]) +
831                                         id->active_entries[id->active_area]);
832 }
833
834 /*
835  * debug_finish_entry:
836  * - set timestamp, caller address, cpu number etc.
837  */
838
839 static inline void
840 debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level,
841                         int exception)
842 {
843         active->id.stck = get_clock();
844         active->id.fields.cpuid = smp_processor_id();
845         active->caller = __builtin_return_address(0);
846         active->id.fields.exception = exception;
847         active->id.fields.level     = level;
848         proceed_active_entry(id);
849         if(exception)
850                 proceed_active_area(id);
851 }
852
853 static int debug_stoppable=1;
854 static int debug_active=1;
855
856 #define CTL_S390DBF 5677
857 #define CTL_S390DBF_STOPPABLE 5678
858 #define CTL_S390DBF_ACTIVE 5679
859
860 /*
861  * proc handler for the running debug_active sysctl
862  * always allow read, allow write only if debug_stoppable is set or
863  * if debug_active is already off
864  */
865 static int
866 s390dbf_procactive(ctl_table *table, int write, struct file *filp,
867                      void __user *buffer, size_t *lenp, loff_t *ppos)
868 {
869         if (!write || debug_stoppable || !debug_active)
870                 return proc_dointvec(table, write, filp, buffer, lenp, ppos);
871         else
872                 return 0;
873 }
874
875
876 static struct ctl_table s390dbf_table[] = {
877         {
878                 .ctl_name       = CTL_S390DBF_STOPPABLE,
879                 .procname       = "debug_stoppable",
880                 .data           = &debug_stoppable,
881                 .maxlen         = sizeof(int),
882                 .mode           = S_IRUGO | S_IWUSR,
883                 .proc_handler   = &proc_dointvec,
884                 .strategy       = &sysctl_intvec,
885         },
886          {
887                 .ctl_name       = CTL_S390DBF_ACTIVE,
888                 .procname       = "debug_active",
889                 .data           = &debug_active,
890                 .maxlen         = sizeof(int),
891                 .mode           = S_IRUGO | S_IWUSR,
892                 .proc_handler   = &s390dbf_procactive,
893                 .strategy       = &sysctl_intvec,
894         },
895         { .ctl_name = 0 }
896 };
897
898 static struct ctl_table s390dbf_dir_table[] = {
899         {
900                 .ctl_name       = CTL_S390DBF,
901                 .procname       = "s390dbf",
902                 .maxlen         = 0,
903                 .mode           = S_IRUGO | S_IXUGO,
904                 .child          = s390dbf_table,
905         },
906         { .ctl_name = 0 }
907 };
908
909 struct ctl_table_header *s390dbf_sysctl_header;
910
911 void
912 debug_stop_all(void)
913 {
914         if (debug_stoppable)
915                 debug_active = 0;
916 }
917
918
919 /*
920  * debug_event_common:
921  * - write debug entry with given size
922  */
923
924 debug_entry_t*
925 debug_event_common(debug_info_t * id, int level, const void *buf, int len)
926 {
927         unsigned long flags;
928         debug_entry_t *active;
929
930         if (!debug_active || !id->areas)
931                 return NULL;
932         spin_lock_irqsave(&id->lock, flags);
933         active = get_active_entry(id);
934         memset(DEBUG_DATA(active), 0, id->buf_size);
935         memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
936         debug_finish_entry(id, active, level, 0);
937         spin_unlock_irqrestore(&id->lock, flags);
938
939         return active;
940 }
941
942 /*
943  * debug_exception_common:
944  * - write debug entry with given size and switch to next debug area
945  */
946
947 debug_entry_t
948 *debug_exception_common(debug_info_t * id, int level, const void *buf, int len)
949 {
950         unsigned long flags;
951         debug_entry_t *active;
952
953         if (!debug_active || !id->areas)
954                 return NULL;
955         spin_lock_irqsave(&id->lock, flags);
956         active = get_active_entry(id);
957         memset(DEBUG_DATA(active), 0, id->buf_size);
958         memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
959         debug_finish_entry(id, active, level, 1);
960         spin_unlock_irqrestore(&id->lock, flags);
961
962         return active;
963 }
964
965 /*
966  * counts arguments in format string for sprintf view
967  */
968
969 static inline int
970 debug_count_numargs(char *string)
971 {
972         int numargs=0;
973
974         while(*string) {
975                 if(*string++=='%')
976                         numargs++;
977         }
978         return(numargs);
979 }
980
981 /*
982  * debug_sprintf_event:
983  */
984
985 debug_entry_t*
986 debug_sprintf_event(debug_info_t* id, int level,char *string,...)
987 {
988         va_list   ap;
989         int numargs,idx;
990         unsigned long flags;
991         debug_sprintf_entry_t *curr_event;
992         debug_entry_t *active;
993
994         if((!id) || (level > id->level))
995                 return NULL;
996         if (!debug_active || !id->areas)
997                 return NULL;
998         numargs=debug_count_numargs(string);
999
1000         spin_lock_irqsave(&id->lock, flags);
1001         active = get_active_entry(id);
1002         curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active);
1003         va_start(ap,string);
1004         curr_event->string=string;
1005         for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1006                 curr_event->args[idx]=va_arg(ap,long);
1007         va_end(ap);
1008         debug_finish_entry(id, active, level, 0);
1009         spin_unlock_irqrestore(&id->lock, flags);
1010
1011         return active;
1012 }
1013
1014 /*
1015  * debug_sprintf_exception:
1016  */
1017
1018 debug_entry_t*
1019 debug_sprintf_exception(debug_info_t* id, int level,char *string,...)
1020 {
1021         va_list   ap;
1022         int numargs,idx;
1023         unsigned long flags;
1024         debug_sprintf_entry_t *curr_event;
1025         debug_entry_t *active;
1026
1027         if((!id) || (level > id->level))
1028                 return NULL;
1029         if (!debug_active || !id->areas)
1030                 return NULL;
1031
1032         numargs=debug_count_numargs(string);
1033
1034         spin_lock_irqsave(&id->lock, flags);
1035         active = get_active_entry(id);
1036         curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active);
1037         va_start(ap,string);
1038         curr_event->string=string;
1039         for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1040                 curr_event->args[idx]=va_arg(ap,long);
1041         va_end(ap);
1042         debug_finish_entry(id, active, level, 1);
1043         spin_unlock_irqrestore(&id->lock, flags);
1044
1045         return active;
1046 }
1047
1048 /*
1049  * debug_init:
1050  * - is called exactly once to initialize the debug feature
1051  */
1052
1053 static int
1054 __init debug_init(void)
1055 {
1056         int rc = 0;
1057
1058         s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table, 1);
1059         down(&debug_lock);
1060         debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT,NULL);
1061         printk(KERN_INFO "debug: Initialization complete\n");
1062         initialized = 1;
1063         up(&debug_lock);
1064
1065         return rc;
1066 }
1067
1068 /*
1069  * debug_register_view:
1070  */
1071
1072 int
1073 debug_register_view(debug_info_t * id, struct debug_view *view)
1074 {
1075         int rc = 0;
1076         int i;
1077         unsigned long flags;
1078         mode_t mode = S_IFREG;
1079         struct dentry *pde;
1080
1081         if (!id)
1082                 goto out;
1083         if (view->prolog_proc || view->format_proc || view->header_proc)
1084                 mode |= S_IRUSR;
1085         if (view->input_proc)
1086                 mode |= S_IWUSR;
1087         pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1088                                 id , &debug_file_ops);
1089         if (!pde){
1090                 printk(KERN_WARNING "debug: debugfs_create_file() failed!"\
1091                         " Cannot register view %s/%s\n", id->name,view->name);
1092                 rc = -1;
1093                 goto out;
1094         }
1095         spin_lock_irqsave(&id->lock, flags);
1096         for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1097                 if (!id->views[i])
1098                         break;
1099         }
1100         if (i == DEBUG_MAX_VIEWS) {
1101                 printk(KERN_WARNING "debug: cannot register view %s/%s\n",
1102                         id->name,view->name);
1103                 printk(KERN_WARNING 
1104                         "debug: maximum number of views reached (%i)!\n", i);
1105                 debugfs_remove(pde);
1106                 rc = -1;
1107         } else {
1108                 id->views[i] = view;
1109                 id->debugfs_entries[i] = pde;
1110         }
1111         spin_unlock_irqrestore(&id->lock, flags);
1112 out:
1113         return rc;
1114 }
1115
1116 /*
1117  * debug_unregister_view:
1118  */
1119
1120 int
1121 debug_unregister_view(debug_info_t * id, struct debug_view *view)
1122 {
1123         int rc = 0;
1124         int i;
1125         unsigned long flags;
1126
1127         if (!id)
1128                 goto out;
1129         spin_lock_irqsave(&id->lock, flags);
1130         for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1131                 if (id->views[i] == view)
1132                         break;
1133         }
1134         if (i == DEBUG_MAX_VIEWS)
1135                 rc = -1;
1136         else {
1137                 debugfs_remove(id->debugfs_entries[i]);
1138                 id->views[i] = NULL;
1139                 rc = 0;
1140         }
1141         spin_unlock_irqrestore(&id->lock, flags);
1142 out:
1143         return rc;
1144 }
1145
1146 static inline char *
1147 debug_get_user_string(const char __user *user_buf, size_t user_len)
1148 {
1149         char* buffer;
1150
1151         buffer = kmalloc(user_len + 1, GFP_KERNEL);
1152         if (!buffer)
1153                 return ERR_PTR(-ENOMEM);
1154         if (copy_from_user(buffer, user_buf, user_len) != 0) {
1155                 kfree(buffer);
1156                 return ERR_PTR(-EFAULT);
1157         }
1158         /* got the string, now strip linefeed. */
1159         if (buffer[user_len - 1] == '\n')
1160                 buffer[user_len - 1] = 0;
1161         else
1162                 buffer[user_len] = 0;
1163         return buffer;
1164 }
1165
1166 static inline int
1167 debug_get_uint(char *buf)
1168 {
1169         int rc;
1170
1171         for(; isspace(*buf); buf++);
1172         rc = simple_strtoul(buf, &buf, 10);
1173         if(*buf){
1174                 printk("debug: no integer specified!\n");
1175                 rc = -EINVAL;
1176         }
1177         return rc;
1178 }
1179
1180 /*
1181  * functions for debug-views
1182  ***********************************
1183 */
1184
1185 /*
1186  * prints out actual debug level
1187  */
1188
1189 static int
1190 debug_prolog_pages_fn(debug_info_t * id,
1191                                  struct debug_view *view, char *out_buf)
1192 {
1193         return sprintf(out_buf, "%i\n", id->pages_per_area);
1194 }
1195
1196 /*
1197  * reads new size (number of pages per debug area)
1198  */
1199
1200 static int
1201 debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
1202                         struct file *file, const char __user *user_buf,
1203                         size_t user_len, loff_t * offset)
1204 {
1205         char *str;
1206         int rc,new_pages;
1207
1208         if (user_len > 0x10000)
1209                 user_len = 0x10000;
1210         if (*offset != 0){
1211                 rc = -EPIPE;
1212                 goto out;
1213         }
1214         str = debug_get_user_string(user_buf,user_len);
1215         if(IS_ERR(str)){
1216                 rc = PTR_ERR(str);
1217                 goto out;
1218         }
1219         new_pages = debug_get_uint(str);
1220         if(new_pages < 0){
1221                 rc = -EINVAL;
1222                 goto free_str;
1223         }
1224         rc = debug_set_size(id,id->nr_areas, new_pages);
1225         if(rc != 0){
1226                 rc = -EINVAL;
1227                 goto free_str;
1228         }
1229         rc = user_len;
1230 free_str:
1231         kfree(str);
1232 out:
1233         *offset += user_len;
1234         return rc;              /* number of input characters */
1235 }
1236
1237 /*
1238  * prints out actual debug level
1239  */
1240
1241 static int
1242 debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf)
1243 {
1244         int rc = 0;
1245
1246         if(id->level == DEBUG_OFF_LEVEL) {
1247                 rc = sprintf(out_buf,"-\n");
1248         }
1249         else {
1250                 rc = sprintf(out_buf, "%i\n", id->level);
1251         }
1252         return rc;
1253 }
1254
1255 /*
1256  * reads new debug level
1257  */
1258
1259 static int
1260 debug_input_level_fn(debug_info_t * id, struct debug_view *view,
1261                         struct file *file, const char __user *user_buf,
1262                         size_t user_len, loff_t * offset)
1263 {
1264         char *str;
1265         int rc,new_level;
1266
1267         if (user_len > 0x10000)
1268                 user_len = 0x10000;
1269         if (*offset != 0){
1270                 rc = -EPIPE;
1271                 goto out;
1272         }
1273         str = debug_get_user_string(user_buf,user_len);
1274         if(IS_ERR(str)){
1275                 rc = PTR_ERR(str);
1276                 goto out;
1277         }
1278         if(str[0] == '-'){
1279                 debug_set_level(id, DEBUG_OFF_LEVEL);
1280                 rc = user_len;
1281                 goto free_str;
1282         } else {
1283                 new_level = debug_get_uint(str);
1284         }
1285         if(new_level < 0) {
1286                 printk(KERN_INFO "debug: level `%s` is not valid\n", str);
1287                 rc = -EINVAL;
1288         } else {
1289                 debug_set_level(id, new_level);
1290                 rc = user_len;
1291         }
1292 free_str:
1293         kfree(str);
1294 out:
1295         *offset += user_len;
1296         return rc;              /* number of input characters */
1297 }
1298
1299
1300 /*
1301  * flushes debug areas
1302  */
1303  
1304 void
1305 debug_flush(debug_info_t* id, int area)
1306 {
1307         unsigned long flags;
1308         int i,j;
1309
1310         if(!id || !id->areas)
1311                 return;
1312         spin_lock_irqsave(&id->lock,flags);
1313         if(area == DEBUG_FLUSH_ALL){
1314                 id->active_area = 0;
1315                 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1316                 for (i = 0; i < id->nr_areas; i++) {
1317                         id->active_pages[i] = 0;
1318                         for(j = 0; j < id->pages_per_area; j++) {
1319                                 memset(id->areas[i][j], 0, PAGE_SIZE);
1320                         }
1321                 }
1322                 printk(KERN_INFO "debug: %s: all areas flushed\n",id->name);
1323         } else if(area >= 0 && area < id->nr_areas) {
1324                 id->active_entries[area] = 0;
1325                 id->active_pages[area] = 0;
1326                 for(i = 0; i < id->pages_per_area; i++) {
1327                         memset(id->areas[area][i],0,PAGE_SIZE);
1328                 }
1329                 printk(KERN_INFO "debug: %s: area %i has been flushed\n",
1330                         id->name, area);
1331         } else {
1332                 printk(KERN_INFO
1333                       "debug: %s: area %i cannot be flushed (range: %i - %i)\n",
1334                         id->name, area, 0, id->nr_areas-1);
1335         }
1336         spin_unlock_irqrestore(&id->lock,flags);
1337 }
1338
1339 /*
1340  * view function: flushes debug areas 
1341  */
1342
1343 static int
1344 debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
1345                         struct file *file, const char __user *user_buf,
1346                         size_t user_len, loff_t * offset)
1347 {
1348         char input_buf[1];
1349         int rc = user_len;
1350
1351         if (user_len > 0x10000)
1352                 user_len = 0x10000;
1353         if (*offset != 0){
1354                 rc = -EPIPE;
1355                 goto out;
1356         }
1357         if (copy_from_user(input_buf, user_buf, 1)){
1358                 rc = -EFAULT;
1359                 goto out;
1360         }
1361         if(input_buf[0] == '-') { 
1362                 debug_flush(id, DEBUG_FLUSH_ALL);
1363                 goto out;
1364         }
1365         if (isdigit(input_buf[0])) {
1366                 int area = ((int) input_buf[0] - (int) '0');
1367                 debug_flush(id, area);
1368                 goto out;
1369         }
1370
1371         printk(KERN_INFO "debug: area `%c` is not valid\n", input_buf[0]);
1372
1373 out:
1374         *offset += user_len;
1375         return rc;              /* number of input characters */
1376 }
1377
1378 /*
1379  * prints debug header in raw format
1380  */
1381
1382 static int
1383 debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
1384                         int area, debug_entry_t * entry, char *out_buf)
1385 {
1386         int rc;
1387
1388         rc = sizeof(debug_entry_t);
1389         memcpy(out_buf,entry,sizeof(debug_entry_t));
1390         return rc;
1391 }
1392
1393 /*
1394  * prints debug data in raw format
1395  */
1396
1397 static int
1398 debug_raw_format_fn(debug_info_t * id, struct debug_view *view,
1399                                char *out_buf, const char *in_buf)
1400 {
1401         int rc;
1402
1403         rc = id->buf_size;
1404         memcpy(out_buf, in_buf, id->buf_size);
1405         return rc;
1406 }
1407
1408 /*
1409  * prints debug data in hex/ascii format
1410  */
1411
1412 static int
1413 debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
1414                           char *out_buf, const char *in_buf)
1415 {
1416         int i, rc = 0;
1417
1418         for (i = 0; i < id->buf_size; i++) {
1419                 rc += sprintf(out_buf + rc, "%02x ",
1420                               ((unsigned char *) in_buf)[i]);
1421         }
1422         rc += sprintf(out_buf + rc, "| ");
1423         for (i = 0; i < id->buf_size; i++) {
1424                 unsigned char c = in_buf[i];
1425                 if (!isprint(c))
1426                         rc += sprintf(out_buf + rc, ".");
1427                 else
1428                         rc += sprintf(out_buf + rc, "%c", c);
1429         }
1430         rc += sprintf(out_buf + rc, "\n");
1431         return rc;
1432 }
1433
1434 /*
1435  * prints header for debug entry
1436  */
1437
1438 int
1439 debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
1440                          int area, debug_entry_t * entry, char *out_buf)
1441 {
1442         struct timespec time_spec;
1443         unsigned long long time;
1444         char *except_str;
1445         unsigned long caller;
1446         int rc = 0;
1447         unsigned int level;
1448
1449         level = entry->id.fields.level;
1450         time = entry->id.stck;
1451         /* adjust todclock to 1970 */
1452         time -= 0x8126d60e46000000LL - (0x3c26700LL * 1000000 * 4096);
1453         tod_to_timeval(time, &time_spec);
1454
1455         if (entry->id.fields.exception)
1456                 except_str = "*";
1457         else
1458                 except_str = "-";
1459         caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN;
1460         rc += sprintf(out_buf, "%02i %011lu:%06lu %1u %1s %02i %p  ",
1461                       area, time_spec.tv_sec, time_spec.tv_nsec / 1000, level,
1462                       except_str, entry->id.fields.cpuid, (void *) caller);
1463         return rc;
1464 }
1465
1466 /*
1467  * prints debug data sprintf-formated:
1468  * debug_sprinf_event/exception calls must be used together with this view
1469  */
1470
1471 #define DEBUG_SPRINTF_MAX_ARGS 10
1472
1473 static int
1474 debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
1475                         char *out_buf, debug_sprintf_entry_t *curr_event)
1476 {
1477         int num_longs, num_used_args = 0,i, rc = 0;
1478         int index[DEBUG_SPRINTF_MAX_ARGS];
1479
1480         /* count of longs fit into one entry */
1481         num_longs = id->buf_size /  sizeof(long); 
1482
1483         if(num_longs < 1)
1484                 goto out; /* bufsize of entry too small */
1485         if(num_longs == 1) {
1486                 /* no args, we use only the string */
1487                 strcpy(out_buf, curr_event->string);
1488                 rc = strlen(curr_event->string);
1489                 goto out;
1490         }
1491
1492         /* number of arguments used for sprintf (without the format string) */
1493         num_used_args   = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1494
1495         memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1496
1497         for(i = 0; i < num_used_args; i++)
1498                 index[i] = i;
1499
1500         rc =  sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1501                 curr_event->args[index[1]], curr_event->args[index[2]],
1502                 curr_event->args[index[3]], curr_event->args[index[4]],
1503                 curr_event->args[index[5]], curr_event->args[index[6]],
1504                 curr_event->args[index[7]], curr_event->args[index[8]],
1505                 curr_event->args[index[9]]);
1506
1507 out:
1508
1509         return rc;
1510 }
1511
1512 /*
1513  * clean up module
1514  */
1515 void
1516 __exit debug_exit(void)
1517 {
1518         debugfs_remove(debug_debugfs_root_entry);
1519         unregister_sysctl_table(s390dbf_sysctl_header);
1520         return;
1521 }
1522
1523 /*
1524  * module definitions
1525  */
1526 postcore_initcall(debug_init);
1527 module_exit(debug_exit);
1528 MODULE_LICENSE("GPL");
1529
1530 EXPORT_SYMBOL(debug_register);
1531 EXPORT_SYMBOL(debug_unregister); 
1532 EXPORT_SYMBOL(debug_set_level);
1533 EXPORT_SYMBOL(debug_stop_all);
1534 EXPORT_SYMBOL(debug_register_view);
1535 EXPORT_SYMBOL(debug_unregister_view);
1536 EXPORT_SYMBOL(debug_event_common);
1537 EXPORT_SYMBOL(debug_exception_common);
1538 EXPORT_SYMBOL(debug_hex_ascii_view);
1539 EXPORT_SYMBOL(debug_raw_view);
1540 EXPORT_SYMBOL(debug_dflt_header_fn);
1541 EXPORT_SYMBOL(debug_sprintf_view);
1542 EXPORT_SYMBOL(debug_sprintf_exception);
1543 EXPORT_SYMBOL(debug_sprintf_event);