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