[S390] zfcpdump support.
[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/stddef.h>
14 #include <linux/kernel.h>
15 #include <linux/errno.h>
16 #include <linux/slab.h>
17 #include <linux/ctype.h>
18 #include <linux/sysctl.h>
19 #include <asm/uaccess.h>
20 #include <asm/semaphore.h>
21 #include <linux/module.h>
22 #include <linux/init.h>
23 #include <linux/fs.h>
24 #include <linux/debugfs.h>
25
26 #include <asm/debug.h>
27
28 #define DEBUG_PROLOG_ENTRY -1
29
30 #define ALL_AREAS 0 /* copy all debug areas */
31 #define NO_AREAS  1 /* copy no debug areas */
32
33 /* typedefs */
34
35 typedef struct file_private_info {
36         loff_t offset;                  /* offset of last read in file */
37         int    act_area;                /* number of last formated area */
38         int    act_page;                /* act page in given area */
39         int    act_entry;               /* last formated entry (offset */
40                                         /* relative to beginning of last */
41                                         /* formated page) */
42         size_t act_entry_offset;        /* up to this offset we copied */
43                                         /* in last read the last formated */
44                                         /* entry to userland */
45         char   temp_buf[2048];          /* buffer for output */
46         debug_info_t *debug_info_org;   /* original debug information */
47         debug_info_t *debug_info_snap;  /* snapshot of debug information */
48         struct debug_view *view;        /* used view of debug info */
49 } file_private_info_t;
50
51 typedef struct
52 {
53         char *string;
54         /* 
55          * This assumes that all args are converted into longs 
56          * on L/390 this is the case for all types of parameter 
57          * except of floats, and long long (32 bit) 
58          *
59          */
60         long args[0];
61 } debug_sprintf_entry_t;
62
63
64 extern void tod_to_timeval(uint64_t todval, struct timespec *xtime);
65
66 /* internal function prototyes */
67
68 static int debug_init(void);
69 static ssize_t debug_output(struct file *file, char __user *user_buf,
70                         size_t user_len, loff_t * offset);
71 static ssize_t debug_input(struct file *file, const char __user *user_buf,
72                         size_t user_len, loff_t * offset);
73 static int debug_open(struct inode *inode, struct file *file);
74 static int debug_close(struct inode *inode, struct file *file);
75 static debug_info_t*  debug_info_create(char *name, int pages_per_area,
76                         int nr_areas, int buf_size);
77 static void debug_info_get(debug_info_t *);
78 static void debug_info_put(debug_info_t *);
79 static int debug_prolog_level_fn(debug_info_t * id,
80                         struct debug_view *view, char *out_buf);
81 static int debug_input_level_fn(debug_info_t * id, struct debug_view *view,
82                         struct file *file, const char __user *user_buf,
83                         size_t user_buf_size, loff_t * offset);
84 static int debug_prolog_pages_fn(debug_info_t * id,
85                         struct debug_view *view, char *out_buf);
86 static int debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
87                         struct file *file, const char __user *user_buf,
88                         size_t user_buf_size, loff_t * offset);
89 static int debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
90                         struct file *file, const char __user *user_buf,
91                         size_t user_buf_size, loff_t * offset);
92 static int debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
93                         char *out_buf, const char *in_buf);
94 static int debug_raw_format_fn(debug_info_t * id,
95                         struct debug_view *view, char *out_buf,
96                         const char *in_buf);
97 static int debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
98                         int area, debug_entry_t * entry, char *out_buf);
99
100 static int debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
101                         char *out_buf, debug_sprintf_entry_t *curr_event);
102
103 /* globals */
104
105 struct debug_view debug_raw_view = {
106         "raw",
107         NULL,
108         &debug_raw_header_fn,
109         &debug_raw_format_fn,
110         NULL,
111         NULL
112 };
113
114 struct debug_view debug_hex_ascii_view = {
115         "hex_ascii",
116         NULL,
117         &debug_dflt_header_fn,
118         &debug_hex_ascii_format_fn,
119         NULL,
120         NULL
121 };
122
123 static struct debug_view debug_level_view = {
124         "level",
125         &debug_prolog_level_fn,
126         NULL,
127         NULL,
128         &debug_input_level_fn,
129         NULL
130 };
131
132 static struct debug_view debug_pages_view = {
133         "pages",
134         &debug_prolog_pages_fn,
135         NULL,
136         NULL,
137         &debug_input_pages_fn,
138         NULL
139 };
140
141 static struct debug_view debug_flush_view = {
142         "flush",
143         NULL,
144         NULL,
145         NULL,
146         &debug_input_flush_fn,
147         NULL
148 };
149
150 struct debug_view debug_sprintf_view = {
151         "sprintf",
152         NULL,
153         &debug_dflt_header_fn,
154         (debug_format_proc_t*)&debug_sprintf_format_fn,
155         NULL,
156         NULL
157 };
158
159 /* used by dump analysis tools to determine version of debug feature */
160 unsigned int debug_feature_version = __DEBUG_FEATURE_VERSION;
161
162 /* static globals */
163
164 static debug_info_t *debug_area_first = NULL;
165 static debug_info_t *debug_area_last = NULL;
166 static DECLARE_MUTEX(debug_lock);
167
168 static int initialized;
169
170 static const struct file_operations debug_file_ops = {
171         .owner   = THIS_MODULE,
172         .read    = debug_output,
173         .write   = debug_input,
174         .open    = debug_open,
175         .release = debug_close,
176 };
177
178 static struct dentry *debug_debugfs_root_entry;
179
180 /* functions */
181
182 /*
183  * debug_areas_alloc
184  * - Debug areas are implemented as a threedimensonal array:
185  *   areas[areanumber][pagenumber][pageoffset]
186  */
187
188 static debug_entry_t***
189 debug_areas_alloc(int pages_per_area, int nr_areas)
190 {
191         debug_entry_t*** areas;
192         int i,j;
193
194         areas = kmalloc(nr_areas *
195                                         sizeof(debug_entry_t**),
196                                         GFP_KERNEL);
197         if (!areas)
198                 goto fail_malloc_areas;
199         for (i = 0; i < nr_areas; i++) {
200                 areas[i] = kmalloc(pages_per_area *
201                                 sizeof(debug_entry_t*),GFP_KERNEL);
202                 if (!areas[i]) {
203                         goto fail_malloc_areas2;
204                 }
205                 for(j = 0; j < pages_per_area; j++) {
206                         areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL);
207                         if(!areas[i][j]) {
208                                 for(j--; j >=0 ; j--) {
209                                         kfree(areas[i][j]);
210                                 }
211                                 kfree(areas[i]);
212                                 goto fail_malloc_areas2;
213                         }
214                 }
215         }
216         return areas;
217
218 fail_malloc_areas2:
219         for(i--; i >= 0; i--){
220                 for(j=0; j < pages_per_area;j++){
221                         kfree(areas[i][j]);
222                 }
223                 kfree(areas[i]);
224         }
225         kfree(areas);
226 fail_malloc_areas:
227         return NULL;
228
229 }
230
231
232 /*
233  * debug_info_alloc
234  * - alloc new debug-info
235  */
236
237 static debug_info_t*
238 debug_info_alloc(char *name, int pages_per_area, int nr_areas, int buf_size,
239                 int level, int mode)
240 {
241         debug_info_t* rc;
242
243         /* alloc everything */
244
245         rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL);
246         if(!rc)
247                 goto fail_malloc_rc;
248         rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
249         if(!rc->active_entries)
250                 goto fail_malloc_active_entries;
251         rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
252         if(!rc->active_pages)
253                 goto fail_malloc_active_pages;
254         if((mode == ALL_AREAS) && (pages_per_area != 0)){
255                 rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
256                 if(!rc->areas)
257                         goto fail_malloc_areas;
258         } else {
259                 rc->areas = NULL;
260         }
261
262         /* initialize members */
263
264         spin_lock_init(&rc->lock);
265         rc->pages_per_area = pages_per_area;
266         rc->nr_areas       = nr_areas;
267         rc->active_area    = 0;
268         rc->level          = level;
269         rc->buf_size       = buf_size;
270         rc->entry_size     = sizeof(debug_entry_t) + buf_size;
271         strlcpy(rc->name, name, sizeof(rc->name));
272         memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
273         memset(rc->debugfs_entries, 0 ,DEBUG_MAX_VIEWS *
274                 sizeof(struct dentry*));
275         atomic_set(&(rc->ref_count), 0);
276
277         return rc;
278
279 fail_malloc_areas:
280         kfree(rc->active_pages);
281 fail_malloc_active_pages:
282         kfree(rc->active_entries);
283 fail_malloc_active_entries:
284         kfree(rc);
285 fail_malloc_rc:
286         return NULL;
287 }
288
289 /*
290  * debug_areas_free
291  * - free all debug areas
292  */
293
294 static void
295 debug_areas_free(debug_info_t* db_info)
296 {
297         int i,j;
298
299         if(!db_info->areas)
300                 return;
301         for (i = 0; i < db_info->nr_areas; i++) {
302                 for(j = 0; j < db_info->pages_per_area; j++) {
303                         kfree(db_info->areas[i][j]);
304                 }
305                 kfree(db_info->areas[i]);
306         }
307         kfree(db_info->areas);
308         db_info->areas = NULL;
309 }
310
311 /*
312  * debug_info_free
313  * - free memory debug-info
314  */
315
316 static void
317 debug_info_free(debug_info_t* db_info){
318         debug_areas_free(db_info);
319         kfree(db_info->active_entries);
320         kfree(db_info->active_pages);
321         kfree(db_info);
322 }
323
324 /*
325  * debug_info_create
326  * - create new debug-info
327  */
328
329 static debug_info_t*
330 debug_info_create(char *name, int pages_per_area, int nr_areas, int buf_size)
331 {
332         debug_info_t* rc;
333
334         rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size,
335                                 DEBUG_DEFAULT_LEVEL, ALL_AREAS);
336         if(!rc) 
337                 goto out;
338
339         /* create root directory */
340         rc->debugfs_root_entry = debugfs_create_dir(rc->name,
341                                         debug_debugfs_root_entry);
342
343         /* append new element to linked list */
344         if (!debug_area_first) {
345                 /* first element in list */
346                 debug_area_first = rc;
347                 rc->prev = NULL;
348         } else {
349                 /* append element to end of list */
350                 debug_area_last->next = rc;
351                 rc->prev = debug_area_last;
352         }
353         debug_area_last = rc;
354         rc->next = NULL;
355
356         debug_info_get(rc);
357 out:
358         return rc;
359 }
360
361 /*
362  * debug_info_copy
363  * - copy debug-info
364  */
365
366 static debug_info_t*
367 debug_info_copy(debug_info_t* in, int mode)
368 {
369         int i,j;
370         debug_info_t* rc;
371         unsigned long flags;
372
373         /* get a consistent copy of the debug areas */
374         do {
375                 rc = debug_info_alloc(in->name, in->pages_per_area,
376                         in->nr_areas, in->buf_size, in->level, mode);
377                 spin_lock_irqsave(&in->lock, flags);
378                 if(!rc)
379                         goto out;
380                 /* has something changed in the meantime ? */
381                 if((rc->pages_per_area == in->pages_per_area) &&
382                    (rc->nr_areas == in->nr_areas)) {
383                         break;
384                 }
385                 spin_unlock_irqrestore(&in->lock, flags);
386                 debug_info_free(rc);
387         } while (1);
388
389         if(!rc || (mode == NO_AREAS))
390                 goto out;
391
392         for(i = 0; i < in->nr_areas; i++){
393                 for(j = 0; j < in->pages_per_area; j++) {
394                         memcpy(rc->areas[i][j], in->areas[i][j],PAGE_SIZE);
395                 }
396         }
397 out:
398         spin_unlock_irqrestore(&in->lock, flags);
399         return rc;
400 }
401
402 /*
403  * debug_info_get
404  * - increments reference count for debug-info
405  */
406
407 static void
408 debug_info_get(debug_info_t * db_info)
409 {
410         if (db_info)
411                 atomic_inc(&db_info->ref_count);
412 }
413
414 /*
415  * debug_info_put:
416  * - decreases reference count for debug-info and frees it if necessary
417  */
418
419 static void
420 debug_info_put(debug_info_t *db_info)
421 {
422         int i;
423
424         if (!db_info)
425                 return;
426         if (atomic_dec_and_test(&db_info->ref_count)) {
427                 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
428                         if (!db_info->views[i])
429                                 continue;
430                         debugfs_remove(db_info->debugfs_entries[i]);
431                 }
432                 debugfs_remove(db_info->debugfs_root_entry);
433                 if(db_info == debug_area_first)
434                         debug_area_first = db_info->next;
435                 if(db_info == debug_area_last)
436                         debug_area_last = db_info->prev;
437                 if(db_info->prev) db_info->prev->next = db_info->next;
438                 if(db_info->next) db_info->next->prev = db_info->prev;
439                 debug_info_free(db_info);
440         }
441 }
442
443 /*
444  * debug_format_entry:
445  * - format one debug entry and return size of formated data
446  */
447
448 static int
449 debug_format_entry(file_private_info_t *p_info)
450 {
451         debug_info_t *id_snap   = p_info->debug_info_snap;
452         struct debug_view *view = p_info->view;
453         debug_entry_t *act_entry;
454         size_t len = 0;
455         if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
456                 /* print prolog */
457                 if (view->prolog_proc)
458                         len += view->prolog_proc(id_snap,view,p_info->temp_buf);
459                 goto out;
460         }
461         if (!id_snap->areas) /* this is true, if we have a prolog only view */
462                 goto out;    /* or if 'pages_per_area' is 0 */
463         act_entry = (debug_entry_t *) ((char*)id_snap->areas[p_info->act_area]
464                                 [p_info->act_page] + p_info->act_entry);
465                         
466         if (act_entry->id.stck == 0LL)
467                         goto out;  /* empty entry */
468         if (view->header_proc)
469                 len += view->header_proc(id_snap, view, p_info->act_area,
470                                         act_entry, p_info->temp_buf + len);
471         if (view->format_proc)
472                 len += view->format_proc(id_snap, view, p_info->temp_buf + len,
473                                                 DEBUG_DATA(act_entry));
474 out:
475         return len;
476 }
477
478 /*
479  * debug_next_entry:
480  * - goto next entry in p_info
481  */
482
483 static inline int
484 debug_next_entry(file_private_info_t *p_info)
485 {
486         debug_info_t *id;
487
488         id = p_info->debug_info_snap;
489         if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
490                 p_info->act_entry = 0;
491                 p_info->act_page  = 0;
492                 goto out;
493         }
494         if(!id->areas)
495                 return 1;
496         p_info->act_entry += id->entry_size;
497         /* switch to next page, if we reached the end of the page  */
498         if (p_info->act_entry > (PAGE_SIZE - id->entry_size)){
499                 /* next page */
500                 p_info->act_entry = 0;
501                 p_info->act_page += 1;
502                 if((p_info->act_page % id->pages_per_area) == 0) {
503                         /* next area */
504                         p_info->act_area++;
505                         p_info->act_page=0;
506                 }
507                 if(p_info->act_area >= id->nr_areas)
508                         return 1;
509         }
510 out:
511         return 0;       
512 }
513
514 /*
515  * debug_output:
516  * - called for user read()
517  * - copies formated debug entries to the user buffer
518  */
519
520 static ssize_t
521 debug_output(struct file *file,         /* file descriptor */
522             char __user *user_buf,      /* user buffer */
523             size_t  len,                /* length of buffer */
524             loff_t *offset)             /* offset in the file */
525 {
526         size_t count = 0;
527         size_t entry_offset;
528         file_private_info_t *p_info;
529
530         p_info = ((file_private_info_t *) file->private_data);
531         if (*offset != p_info->offset) 
532                 return -EPIPE;
533         if(p_info->act_area >= p_info->debug_info_snap->nr_areas)
534                 return 0;
535         entry_offset = p_info->act_entry_offset;
536         while(count < len){
537                 int formatted_line_size;
538                 int formatted_line_residue;
539                 int user_buf_residue;
540                 size_t copy_size;
541
542                 formatted_line_size = debug_format_entry(p_info);
543                 formatted_line_residue = formatted_line_size - entry_offset;
544                 user_buf_residue = len-count;
545                 copy_size = min(user_buf_residue, formatted_line_residue);
546                 if(copy_size){
547                         if (copy_to_user(user_buf + count, p_info->temp_buf
548                                         + entry_offset, copy_size))
549                                 return -EFAULT;
550                         count += copy_size;
551                         entry_offset += copy_size;
552                 }
553                 if(copy_size == formatted_line_residue){
554                         entry_offset = 0;
555                         if(debug_next_entry(p_info))
556                                 goto out;
557                 }
558         }
559 out:
560         p_info->offset           = *offset + count;
561         p_info->act_entry_offset = entry_offset;
562         *offset = p_info->offset;
563         return count;
564 }
565
566 /*
567  * debug_input:
568  * - called for user write()
569  * - calls input function of view
570  */
571
572 static ssize_t
573 debug_input(struct file *file, const char __user *user_buf, size_t length,
574                 loff_t *offset)
575 {
576         int rc = 0;
577         file_private_info_t *p_info;
578
579         down(&debug_lock);
580         p_info = ((file_private_info_t *) file->private_data);
581         if (p_info->view->input_proc)
582                 rc = p_info->view->input_proc(p_info->debug_info_org,
583                                               p_info->view, file, user_buf,
584                                               length, offset);
585         else
586                 rc = -EPERM;
587         up(&debug_lock);
588         return rc;              /* number of input characters */
589 }
590
591 /*
592  * debug_open:
593  * - called for user open()
594  * - copies formated output to private_data area of the file
595  *   handle
596  */
597
598 static int
599 debug_open(struct inode *inode, struct file *file)
600 {
601         int i = 0, rc = 0;
602         file_private_info_t *p_info;
603         debug_info_t *debug_info, *debug_info_snapshot;
604
605         down(&debug_lock);
606         debug_info = file->f_path.dentry->d_inode->i_private;
607         /* find debug view */
608         for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
609                 if (!debug_info->views[i])
610                         continue;
611                 else if (debug_info->debugfs_entries[i] ==
612                          file->f_path.dentry) {
613                         goto found;     /* found view ! */
614                 }
615         }
616         /* no entry found */
617         rc = -EINVAL;
618         goto out;
619
620 found:
621
622         /* Make snapshot of current debug areas to get it consistent.     */
623         /* To copy all the areas is only needed, if we have a view which  */
624         /* formats the debug areas. */
625
626         if(!debug_info->views[i]->format_proc &&
627                 !debug_info->views[i]->header_proc){
628                 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS);
629         } else {
630                 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS);
631         }
632
633         if(!debug_info_snapshot){
634                 rc = -ENOMEM;
635                 goto out;
636         }
637         p_info = kmalloc(sizeof(file_private_info_t),
638                                                 GFP_KERNEL);
639         if(!p_info){
640                 if(debug_info_snapshot)
641                         debug_info_free(debug_info_snapshot);
642                 rc = -ENOMEM;
643                 goto out;
644         }
645         p_info->offset = 0;
646         p_info->debug_info_snap = debug_info_snapshot;
647         p_info->debug_info_org  = debug_info;
648         p_info->view = debug_info->views[i];
649         p_info->act_area = 0;
650         p_info->act_page = 0;
651         p_info->act_entry = DEBUG_PROLOG_ENTRY;
652         p_info->act_entry_offset = 0;
653         file->private_data = p_info;
654         debug_info_get(debug_info);
655 out:
656         up(&debug_lock);
657         return rc;
658 }
659
660 /*
661  * debug_close:
662  * - called for user close()
663  * - deletes  private_data area of the file handle
664  */
665
666 static int
667 debug_close(struct inode *inode, struct file *file)
668 {
669         file_private_info_t *p_info;
670         p_info = (file_private_info_t *) file->private_data;
671         if(p_info->debug_info_snap)
672                 debug_info_free(p_info->debug_info_snap);
673         debug_info_put(p_info->debug_info_org);
674         kfree(file->private_data);
675         return 0;               /* success */
676 }
677
678 /*
679  * debug_register:
680  * - creates and initializes debug area for the caller
681  * - returns handle for debug area
682  */
683
684 debug_info_t*
685 debug_register (char *name, int pages_per_area, int nr_areas, int buf_size)
686 {
687         debug_info_t *rc = NULL;
688
689         if (!initialized)
690                 BUG();
691         down(&debug_lock);
692
693         /* create new debug_info */
694
695         rc = debug_info_create(name, pages_per_area, nr_areas, buf_size);
696         if(!rc) 
697                 goto out;
698         debug_register_view(rc, &debug_level_view);
699         debug_register_view(rc, &debug_flush_view);
700         debug_register_view(rc, &debug_pages_view);
701 out:
702         if (!rc){
703                 printk(KERN_ERR "debug: debug_register failed for %s\n",name);
704         }
705         up(&debug_lock);
706         return rc;
707 }
708
709 /*
710  * debug_unregister:
711  * - give back debug area
712  */
713
714 void
715 debug_unregister(debug_info_t * id)
716 {
717         if (!id)
718                 goto out;
719         down(&debug_lock);
720         debug_info_put(id);
721         up(&debug_lock);
722
723 out:
724         return;
725 }
726
727 /*
728  * debug_set_size:
729  * - set area size (number of pages) and number of areas
730  */
731 static int
732 debug_set_size(debug_info_t* id, int nr_areas, int pages_per_area)
733 {
734         unsigned long flags;
735         debug_entry_t *** new_areas;
736         int rc=0;
737
738         if(!id || (nr_areas <= 0) || (pages_per_area < 0))
739                 return -EINVAL;
740         if(pages_per_area > 0){
741                 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
742                 if(!new_areas) {
743                         printk(KERN_WARNING "debug: could not allocate memory "\
744                                          "for pagenumber: %i\n",pages_per_area);
745                         rc = -ENOMEM;
746                         goto out;
747                 }
748         } else {
749                 new_areas = NULL;
750         }
751         spin_lock_irqsave(&id->lock,flags);
752         debug_areas_free(id);
753         id->areas = new_areas;
754         id->nr_areas = nr_areas;
755         id->pages_per_area = pages_per_area;
756         id->active_area = 0;
757         memset(id->active_entries,0,sizeof(int)*id->nr_areas);
758         memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
759         spin_unlock_irqrestore(&id->lock,flags);
760         printk(KERN_INFO "debug: %s: set new size (%i pages)\n"\
761                          ,id->name, pages_per_area);
762 out:
763         return rc;
764 }
765
766 /*
767  * debug_set_level:
768  * - set actual debug level
769  */
770
771 void
772 debug_set_level(debug_info_t* id, int new_level)
773 {
774         unsigned long flags;
775         if(!id)
776                 return; 
777         spin_lock_irqsave(&id->lock,flags);
778         if(new_level == DEBUG_OFF_LEVEL){
779                 id->level = DEBUG_OFF_LEVEL;
780                 printk(KERN_INFO "debug: %s: switched off\n",id->name);
781         } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
782                 printk(KERN_INFO
783                         "debug: %s: level %i is out of range (%i - %i)\n",
784                         id->name, new_level, 0, DEBUG_MAX_LEVEL);
785         } else {
786                 id->level = new_level;
787         }
788         spin_unlock_irqrestore(&id->lock,flags);
789 }
790
791
792 /*
793  * proceed_active_entry:
794  * - set active entry to next in the ring buffer
795  */
796
797 static inline void
798 proceed_active_entry(debug_info_t * id)
799 {
800         if ((id->active_entries[id->active_area] += id->entry_size)
801             > (PAGE_SIZE - id->entry_size)){
802                 id->active_entries[id->active_area] = 0;
803                 id->active_pages[id->active_area] =
804                         (id->active_pages[id->active_area] + 1) %
805                         id->pages_per_area;
806         }
807 }
808
809 /*
810  * proceed_active_area:
811  * - set active area to next in the ring buffer
812  */
813
814 static inline void
815 proceed_active_area(debug_info_t * id)
816 {
817         id->active_area++;
818         id->active_area = id->active_area % id->nr_areas;
819 }
820
821 /*
822  * get_active_entry:
823  */
824
825 static inline debug_entry_t*
826 get_active_entry(debug_info_t * id)
827 {
828         return (debug_entry_t *) (((char *) id->areas[id->active_area]
829                                         [id->active_pages[id->active_area]]) +
830                                         id->active_entries[id->active_area]);
831 }
832
833 /*
834  * debug_finish_entry:
835  * - set timestamp, caller address, cpu number etc.
836  */
837
838 static inline void
839 debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level,
840                         int exception)
841 {
842         active->id.stck = get_clock();
843         active->id.fields.cpuid = smp_processor_id();
844         active->caller = __builtin_return_address(0);
845         active->id.fields.exception = exception;
846         active->id.fields.level     = level;
847         proceed_active_entry(id);
848         if(exception)
849                 proceed_active_area(id);
850 }
851
852 static int debug_stoppable=1;
853 static int debug_active=1;
854
855 #define CTL_S390DBF_STOPPABLE 5678
856 #define CTL_S390DBF_ACTIVE 5679
857
858 /*
859  * proc handler for the running debug_active sysctl
860  * always allow read, allow write only if debug_stoppable is set or
861  * if debug_active is already off
862  */
863 static int
864 s390dbf_procactive(ctl_table *table, int write, struct file *filp,
865                      void __user *buffer, size_t *lenp, loff_t *ppos)
866 {
867         if (!write || debug_stoppable || !debug_active)
868                 return proc_dointvec(table, write, filp, buffer, lenp, ppos);
869         else
870                 return 0;
871 }
872
873
874 static struct ctl_table s390dbf_table[] = {
875         {
876                 .ctl_name       = CTL_S390DBF_STOPPABLE,
877                 .procname       = "debug_stoppable",
878                 .data           = &debug_stoppable,
879                 .maxlen         = sizeof(int),
880                 .mode           = S_IRUGO | S_IWUSR,
881                 .proc_handler   = &proc_dointvec,
882                 .strategy       = &sysctl_intvec,
883         },
884          {
885                 .ctl_name       = CTL_S390DBF_ACTIVE,
886                 .procname       = "debug_active",
887                 .data           = &debug_active,
888                 .maxlen         = sizeof(int),
889                 .mode           = S_IRUGO | S_IWUSR,
890                 .proc_handler   = &s390dbf_procactive,
891                 .strategy       = &sysctl_intvec,
892         },
893         { .ctl_name = 0 }
894 };
895
896 static struct ctl_table s390dbf_dir_table[] = {
897         {
898                 .ctl_name       = CTL_S390DBF,
899                 .procname       = "s390dbf",
900                 .maxlen         = 0,
901                 .mode           = S_IRUGO | S_IXUGO,
902                 .child          = s390dbf_table,
903         },
904         { .ctl_name = 0 }
905 };
906
907 static struct ctl_table_header *s390dbf_sysctl_header;
908
909 void
910 debug_stop_all(void)
911 {
912         if (debug_stoppable)
913                 debug_active = 0;
914 }
915
916
917 /*
918  * debug_event_common:
919  * - write debug entry with given size
920  */
921
922 debug_entry_t*
923 debug_event_common(debug_info_t * id, int level, const void *buf, int len)
924 {
925         unsigned long flags;
926         debug_entry_t *active;
927
928         if (!debug_active || !id->areas)
929                 return NULL;
930         spin_lock_irqsave(&id->lock, flags);
931         active = get_active_entry(id);
932         memset(DEBUG_DATA(active), 0, id->buf_size);
933         memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
934         debug_finish_entry(id, active, level, 0);
935         spin_unlock_irqrestore(&id->lock, flags);
936
937         return active;
938 }
939
940 /*
941  * debug_exception_common:
942  * - write debug entry with given size and switch to next debug area
943  */
944
945 debug_entry_t
946 *debug_exception_common(debug_info_t * id, int level, const void *buf, int len)
947 {
948         unsigned long flags;
949         debug_entry_t *active;
950
951         if (!debug_active || !id->areas)
952                 return NULL;
953         spin_lock_irqsave(&id->lock, flags);
954         active = get_active_entry(id);
955         memset(DEBUG_DATA(active), 0, id->buf_size);
956         memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
957         debug_finish_entry(id, active, level, 1);
958         spin_unlock_irqrestore(&id->lock, flags);
959
960         return active;
961 }
962
963 /*
964  * counts arguments in format string for sprintf view
965  */
966
967 static inline int
968 debug_count_numargs(char *string)
969 {
970         int numargs=0;
971
972         while(*string) {
973                 if(*string++=='%')
974                         numargs++;
975         }
976         return(numargs);
977 }
978
979 /*
980  * debug_sprintf_event:
981  */
982
983 debug_entry_t*
984 debug_sprintf_event(debug_info_t* id, int level,char *string,...)
985 {
986         va_list   ap;
987         int numargs,idx;
988         unsigned long flags;
989         debug_sprintf_entry_t *curr_event;
990         debug_entry_t *active;
991
992         if((!id) || (level > id->level))
993                 return NULL;
994         if (!debug_active || !id->areas)
995                 return NULL;
996         numargs=debug_count_numargs(string);
997
998         spin_lock_irqsave(&id->lock, flags);
999         active = get_active_entry(id);
1000         curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active);
1001         va_start(ap,string);
1002         curr_event->string=string;
1003         for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1004                 curr_event->args[idx]=va_arg(ap,long);
1005         va_end(ap);
1006         debug_finish_entry(id, active, level, 0);
1007         spin_unlock_irqrestore(&id->lock, flags);
1008
1009         return active;
1010 }
1011
1012 /*
1013  * debug_sprintf_exception:
1014  */
1015
1016 debug_entry_t*
1017 debug_sprintf_exception(debug_info_t* id, int level,char *string,...)
1018 {
1019         va_list   ap;
1020         int numargs,idx;
1021         unsigned long flags;
1022         debug_sprintf_entry_t *curr_event;
1023         debug_entry_t *active;
1024
1025         if((!id) || (level > id->level))
1026                 return NULL;
1027         if (!debug_active || !id->areas)
1028                 return NULL;
1029
1030         numargs=debug_count_numargs(string);
1031
1032         spin_lock_irqsave(&id->lock, flags);
1033         active = get_active_entry(id);
1034         curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active);
1035         va_start(ap,string);
1036         curr_event->string=string;
1037         for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1038                 curr_event->args[idx]=va_arg(ap,long);
1039         va_end(ap);
1040         debug_finish_entry(id, active, level, 1);
1041         spin_unlock_irqrestore(&id->lock, flags);
1042
1043         return active;
1044 }
1045
1046 /*
1047  * debug_init:
1048  * - is called exactly once to initialize the debug feature
1049  */
1050
1051 static int
1052 __init debug_init(void)
1053 {
1054         int rc = 0;
1055
1056         s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1057         down(&debug_lock);
1058         debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT,NULL);
1059         printk(KERN_INFO "debug: Initialization complete\n");
1060         initialized = 1;
1061         up(&debug_lock);
1062
1063         return rc;
1064 }
1065
1066 /*
1067  * debug_register_view:
1068  */
1069
1070 int
1071 debug_register_view(debug_info_t * id, struct debug_view *view)
1072 {
1073         int rc = 0;
1074         int i;
1075         unsigned long flags;
1076         mode_t mode = S_IFREG;
1077         struct dentry *pde;
1078
1079         if (!id)
1080                 goto out;
1081         if (view->prolog_proc || view->format_proc || view->header_proc)
1082                 mode |= S_IRUSR;
1083         if (view->input_proc)
1084                 mode |= S_IWUSR;
1085         pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1086                                 id , &debug_file_ops);
1087         if (!pde){
1088                 printk(KERN_WARNING "debug: debugfs_create_file() failed!"\
1089                         " Cannot register view %s/%s\n", id->name,view->name);
1090                 rc = -1;
1091                 goto out;
1092         }
1093         spin_lock_irqsave(&id->lock, flags);
1094         for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1095                 if (!id->views[i])
1096                         break;
1097         }
1098         if (i == DEBUG_MAX_VIEWS) {
1099                 printk(KERN_WARNING "debug: cannot register view %s/%s\n",
1100                         id->name,view->name);
1101                 printk(KERN_WARNING 
1102                         "debug: maximum number of views reached (%i)!\n", i);
1103                 debugfs_remove(pde);
1104                 rc = -1;
1105         } else {
1106                 id->views[i] = view;
1107                 id->debugfs_entries[i] = pde;
1108         }
1109         spin_unlock_irqrestore(&id->lock, flags);
1110 out:
1111         return rc;
1112 }
1113
1114 /*
1115  * debug_unregister_view:
1116  */
1117
1118 int
1119 debug_unregister_view(debug_info_t * id, struct debug_view *view)
1120 {
1121         int rc = 0;
1122         int i;
1123         unsigned long flags;
1124
1125         if (!id)
1126                 goto out;
1127         spin_lock_irqsave(&id->lock, flags);
1128         for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1129                 if (id->views[i] == view)
1130                         break;
1131         }
1132         if (i == DEBUG_MAX_VIEWS)
1133                 rc = -1;
1134         else {
1135                 debugfs_remove(id->debugfs_entries[i]);
1136                 id->views[i] = NULL;
1137                 rc = 0;
1138         }
1139         spin_unlock_irqrestore(&id->lock, flags);
1140 out:
1141         return rc;
1142 }
1143
1144 static inline char *
1145 debug_get_user_string(const char __user *user_buf, size_t user_len)
1146 {
1147         char* buffer;
1148
1149         buffer = kmalloc(user_len + 1, GFP_KERNEL);
1150         if (!buffer)
1151                 return ERR_PTR(-ENOMEM);
1152         if (copy_from_user(buffer, user_buf, user_len) != 0) {
1153                 kfree(buffer);
1154                 return ERR_PTR(-EFAULT);
1155         }
1156         /* got the string, now strip linefeed. */
1157         if (buffer[user_len - 1] == '\n')
1158                 buffer[user_len - 1] = 0;
1159         else
1160                 buffer[user_len] = 0;
1161         return buffer;
1162 }
1163
1164 static inline int
1165 debug_get_uint(char *buf)
1166 {
1167         int rc;
1168
1169         for(; isspace(*buf); buf++);
1170         rc = simple_strtoul(buf, &buf, 10);
1171         if(*buf){
1172                 printk("debug: no integer specified!\n");
1173                 rc = -EINVAL;
1174         }
1175         return rc;
1176 }
1177
1178 /*
1179  * functions for debug-views
1180  ***********************************
1181 */
1182
1183 /*
1184  * prints out actual debug level
1185  */
1186
1187 static int
1188 debug_prolog_pages_fn(debug_info_t * id,
1189                                  struct debug_view *view, char *out_buf)
1190 {
1191         return sprintf(out_buf, "%i\n", id->pages_per_area);
1192 }
1193
1194 /*
1195  * reads new size (number of pages per debug area)
1196  */
1197
1198 static int
1199 debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
1200                         struct file *file, const char __user *user_buf,
1201                         size_t user_len, loff_t * offset)
1202 {
1203         char *str;
1204         int rc,new_pages;
1205
1206         if (user_len > 0x10000)
1207                 user_len = 0x10000;
1208         if (*offset != 0){
1209                 rc = -EPIPE;
1210                 goto out;
1211         }
1212         str = debug_get_user_string(user_buf,user_len);
1213         if(IS_ERR(str)){
1214                 rc = PTR_ERR(str);
1215                 goto out;
1216         }
1217         new_pages = debug_get_uint(str);
1218         if(new_pages < 0){
1219                 rc = -EINVAL;
1220                 goto free_str;
1221         }
1222         rc = debug_set_size(id,id->nr_areas, new_pages);
1223         if(rc != 0){
1224                 rc = -EINVAL;
1225                 goto free_str;
1226         }
1227         rc = user_len;
1228 free_str:
1229         kfree(str);
1230 out:
1231         *offset += user_len;
1232         return rc;              /* number of input characters */
1233 }
1234
1235 /*
1236  * prints out actual debug level
1237  */
1238
1239 static int
1240 debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf)
1241 {
1242         int rc = 0;
1243
1244         if(id->level == DEBUG_OFF_LEVEL) {
1245                 rc = sprintf(out_buf,"-\n");
1246         }
1247         else {
1248                 rc = sprintf(out_buf, "%i\n", id->level);
1249         }
1250         return rc;
1251 }
1252
1253 /*
1254  * reads new debug level
1255  */
1256
1257 static int
1258 debug_input_level_fn(debug_info_t * id, struct debug_view *view,
1259                         struct file *file, const char __user *user_buf,
1260                         size_t user_len, loff_t * offset)
1261 {
1262         char *str;
1263         int rc,new_level;
1264
1265         if (user_len > 0x10000)
1266                 user_len = 0x10000;
1267         if (*offset != 0){
1268                 rc = -EPIPE;
1269                 goto out;
1270         }
1271         str = debug_get_user_string(user_buf,user_len);
1272         if(IS_ERR(str)){
1273                 rc = PTR_ERR(str);
1274                 goto out;
1275         }
1276         if(str[0] == '-'){
1277                 debug_set_level(id, DEBUG_OFF_LEVEL);
1278                 rc = user_len;
1279                 goto free_str;
1280         } else {
1281                 new_level = debug_get_uint(str);
1282         }
1283         if(new_level < 0) {
1284                 printk(KERN_INFO "debug: level `%s` is not valid\n", str);
1285                 rc = -EINVAL;
1286         } else {
1287                 debug_set_level(id, new_level);
1288                 rc = user_len;
1289         }
1290 free_str:
1291         kfree(str);
1292 out:
1293         *offset += user_len;
1294         return rc;              /* number of input characters */
1295 }
1296
1297
1298 /*
1299  * flushes debug areas
1300  */
1301  
1302 static void debug_flush(debug_info_t* id, int area)
1303 {
1304         unsigned long flags;
1305         int i,j;
1306
1307         if(!id || !id->areas)
1308                 return;
1309         spin_lock_irqsave(&id->lock,flags);
1310         if(area == DEBUG_FLUSH_ALL){
1311                 id->active_area = 0;
1312                 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1313                 for (i = 0; i < id->nr_areas; i++) {
1314                         id->active_pages[i] = 0;
1315                         for(j = 0; j < id->pages_per_area; j++) {
1316                                 memset(id->areas[i][j], 0, PAGE_SIZE);
1317                         }
1318                 }
1319                 printk(KERN_INFO "debug: %s: all areas flushed\n",id->name);
1320         } else if(area >= 0 && area < id->nr_areas) {
1321                 id->active_entries[area] = 0;
1322                 id->active_pages[area] = 0;
1323                 for(i = 0; i < id->pages_per_area; i++) {
1324                         memset(id->areas[area][i],0,PAGE_SIZE);
1325                 }
1326                 printk(KERN_INFO "debug: %s: area %i has been flushed\n",
1327                         id->name, area);
1328         } else {
1329                 printk(KERN_INFO
1330                       "debug: %s: area %i cannot be flushed (range: %i - %i)\n",
1331                         id->name, area, 0, id->nr_areas-1);
1332         }
1333         spin_unlock_irqrestore(&id->lock,flags);
1334 }
1335
1336 /*
1337  * view function: flushes debug areas 
1338  */
1339
1340 static int
1341 debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
1342                         struct file *file, const char __user *user_buf,
1343                         size_t user_len, loff_t * offset)
1344 {
1345         char input_buf[1];
1346         int rc = user_len;
1347
1348         if (user_len > 0x10000)
1349                 user_len = 0x10000;
1350         if (*offset != 0){
1351                 rc = -EPIPE;
1352                 goto out;
1353         }
1354         if (copy_from_user(input_buf, user_buf, 1)){
1355                 rc = -EFAULT;
1356                 goto out;
1357         }
1358         if(input_buf[0] == '-') { 
1359                 debug_flush(id, DEBUG_FLUSH_ALL);
1360                 goto out;
1361         }
1362         if (isdigit(input_buf[0])) {
1363                 int area = ((int) input_buf[0] - (int) '0');
1364                 debug_flush(id, area);
1365                 goto out;
1366         }
1367
1368         printk(KERN_INFO "debug: area `%c` is not valid\n", input_buf[0]);
1369
1370 out:
1371         *offset += user_len;
1372         return rc;              /* number of input characters */
1373 }
1374
1375 /*
1376  * prints debug header in raw format
1377  */
1378
1379 static int
1380 debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
1381                         int area, debug_entry_t * entry, char *out_buf)
1382 {
1383         int rc;
1384
1385         rc = sizeof(debug_entry_t);
1386         memcpy(out_buf,entry,sizeof(debug_entry_t));
1387         return rc;
1388 }
1389
1390 /*
1391  * prints debug data in raw format
1392  */
1393
1394 static int
1395 debug_raw_format_fn(debug_info_t * id, struct debug_view *view,
1396                                char *out_buf, const char *in_buf)
1397 {
1398         int rc;
1399
1400         rc = id->buf_size;
1401         memcpy(out_buf, in_buf, id->buf_size);
1402         return rc;
1403 }
1404
1405 /*
1406  * prints debug data in hex/ascii format
1407  */
1408
1409 static int
1410 debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
1411                           char *out_buf, const char *in_buf)
1412 {
1413         int i, rc = 0;
1414
1415         for (i = 0; i < id->buf_size; i++) {
1416                 rc += sprintf(out_buf + rc, "%02x ",
1417                               ((unsigned char *) in_buf)[i]);
1418         }
1419         rc += sprintf(out_buf + rc, "| ");
1420         for (i = 0; i < id->buf_size; i++) {
1421                 unsigned char c = in_buf[i];
1422                 if (!isprint(c))
1423                         rc += sprintf(out_buf + rc, ".");
1424                 else
1425                         rc += sprintf(out_buf + rc, "%c", c);
1426         }
1427         rc += sprintf(out_buf + rc, "\n");
1428         return rc;
1429 }
1430
1431 /*
1432  * prints header for debug entry
1433  */
1434
1435 int
1436 debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
1437                          int area, debug_entry_t * entry, char *out_buf)
1438 {
1439         struct timespec time_spec;
1440         unsigned long long time;
1441         char *except_str;
1442         unsigned long caller;
1443         int rc = 0;
1444         unsigned int level;
1445
1446         level = entry->id.fields.level;
1447         time = entry->id.stck;
1448         /* adjust todclock to 1970 */
1449         time -= 0x8126d60e46000000LL - (0x3c26700LL * 1000000 * 4096);
1450         tod_to_timeval(time, &time_spec);
1451
1452         if (entry->id.fields.exception)
1453                 except_str = "*";
1454         else
1455                 except_str = "-";
1456         caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN;
1457         rc += sprintf(out_buf, "%02i %011lu:%06lu %1u %1s %02i %p  ",
1458                       area, time_spec.tv_sec, time_spec.tv_nsec / 1000, level,
1459                       except_str, entry->id.fields.cpuid, (void *) caller);
1460         return rc;
1461 }
1462
1463 /*
1464  * prints debug data sprintf-formated:
1465  * debug_sprinf_event/exception calls must be used together with this view
1466  */
1467
1468 #define DEBUG_SPRINTF_MAX_ARGS 10
1469
1470 static int
1471 debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
1472                         char *out_buf, debug_sprintf_entry_t *curr_event)
1473 {
1474         int num_longs, num_used_args = 0,i, rc = 0;
1475         int index[DEBUG_SPRINTF_MAX_ARGS];
1476
1477         /* count of longs fit into one entry */
1478         num_longs = id->buf_size /  sizeof(long); 
1479
1480         if(num_longs < 1)
1481                 goto out; /* bufsize of entry too small */
1482         if(num_longs == 1) {
1483                 /* no args, we use only the string */
1484                 strcpy(out_buf, curr_event->string);
1485                 rc = strlen(curr_event->string);
1486                 goto out;
1487         }
1488
1489         /* number of arguments used for sprintf (without the format string) */
1490         num_used_args   = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1491
1492         memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1493
1494         for(i = 0; i < num_used_args; i++)
1495                 index[i] = i;
1496
1497         rc =  sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1498                 curr_event->args[index[1]], curr_event->args[index[2]],
1499                 curr_event->args[index[3]], curr_event->args[index[4]],
1500                 curr_event->args[index[5]], curr_event->args[index[6]],
1501                 curr_event->args[index[7]], curr_event->args[index[8]],
1502                 curr_event->args[index[9]]);
1503
1504 out:
1505
1506         return rc;
1507 }
1508
1509 /*
1510  * clean up module
1511  */
1512 static void __exit debug_exit(void)
1513 {
1514         debugfs_remove(debug_debugfs_root_entry);
1515         unregister_sysctl_table(s390dbf_sysctl_header);
1516         return;
1517 }
1518
1519 /*
1520  * module definitions
1521  */
1522 postcore_initcall(debug_init);
1523 module_exit(debug_exit);
1524 MODULE_LICENSE("GPL");
1525
1526 EXPORT_SYMBOL(debug_register);
1527 EXPORT_SYMBOL(debug_unregister); 
1528 EXPORT_SYMBOL(debug_set_level);
1529 EXPORT_SYMBOL(debug_stop_all);
1530 EXPORT_SYMBOL(debug_register_view);
1531 EXPORT_SYMBOL(debug_unregister_view);
1532 EXPORT_SYMBOL(debug_event_common);
1533 EXPORT_SYMBOL(debug_exception_common);
1534 EXPORT_SYMBOL(debug_hex_ascii_view);
1535 EXPORT_SYMBOL(debug_raw_view);
1536 EXPORT_SYMBOL(debug_dflt_header_fn);
1537 EXPORT_SYMBOL(debug_sprintf_view);
1538 EXPORT_SYMBOL(debug_sprintf_exception);
1539 EXPORT_SYMBOL(debug_sprintf_event);