Merge branch 'for-2.6.37/misc' of git://git.kernel.dk/linux-2.6-block
[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         .llseek  = no_llseek,
178 };
179
180 static struct dentry *debug_debugfs_root_entry;
181
182 /* functions */
183
184 /*
185  * debug_areas_alloc
186  * - Debug areas are implemented as a threedimensonal array:
187  *   areas[areanumber][pagenumber][pageoffset]
188  */
189
190 static debug_entry_t***
191 debug_areas_alloc(int pages_per_area, int nr_areas)
192 {
193         debug_entry_t*** areas;
194         int i,j;
195
196         areas = kmalloc(nr_areas *
197                                         sizeof(debug_entry_t**),
198                                         GFP_KERNEL);
199         if (!areas)
200                 goto fail_malloc_areas;
201         for (i = 0; i < nr_areas; i++) {
202                 areas[i] = kmalloc(pages_per_area *
203                                 sizeof(debug_entry_t*),GFP_KERNEL);
204                 if (!areas[i]) {
205                         goto fail_malloc_areas2;
206                 }
207                 for(j = 0; j < pages_per_area; j++) {
208                         areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL);
209                         if(!areas[i][j]) {
210                                 for(j--; j >=0 ; j--) {
211                                         kfree(areas[i][j]);
212                                 }
213                                 kfree(areas[i]);
214                                 goto fail_malloc_areas2;
215                         }
216                 }
217         }
218         return areas;
219
220 fail_malloc_areas2:
221         for(i--; i >= 0; i--){
222                 for(j=0; j < pages_per_area;j++){
223                         kfree(areas[i][j]);
224                 }
225                 kfree(areas[i]);
226         }
227         kfree(areas);
228 fail_malloc_areas:
229         return NULL;
230
231 }
232
233
234 /*
235  * debug_info_alloc
236  * - alloc new debug-info
237  */
238
239 static debug_info_t*
240 debug_info_alloc(const char *name, int pages_per_area, int nr_areas,
241                  int buf_size, int level, int mode)
242 {
243         debug_info_t* rc;
244
245         /* alloc everything */
246
247         rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL);
248         if(!rc)
249                 goto fail_malloc_rc;
250         rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
251         if(!rc->active_entries)
252                 goto fail_malloc_active_entries;
253         rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
254         if(!rc->active_pages)
255                 goto fail_malloc_active_pages;
256         if((mode == ALL_AREAS) && (pages_per_area != 0)){
257                 rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
258                 if(!rc->areas)
259                         goto fail_malloc_areas;
260         } else {
261                 rc->areas = NULL;
262         }
263
264         /* initialize members */
265
266         spin_lock_init(&rc->lock);
267         rc->pages_per_area = pages_per_area;
268         rc->nr_areas       = nr_areas;
269         rc->active_area    = 0;
270         rc->level          = level;
271         rc->buf_size       = buf_size;
272         rc->entry_size     = sizeof(debug_entry_t) + buf_size;
273         strlcpy(rc->name, name, sizeof(rc->name));
274         memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
275         memset(rc->debugfs_entries, 0 ,DEBUG_MAX_VIEWS *
276                 sizeof(struct dentry*));
277         atomic_set(&(rc->ref_count), 0);
278
279         return rc;
280
281 fail_malloc_areas:
282         kfree(rc->active_pages);
283 fail_malloc_active_pages:
284         kfree(rc->active_entries);
285 fail_malloc_active_entries:
286         kfree(rc);
287 fail_malloc_rc:
288         return NULL;
289 }
290
291 /*
292  * debug_areas_free
293  * - free all debug areas
294  */
295
296 static void
297 debug_areas_free(debug_info_t* db_info)
298 {
299         int i,j;
300
301         if(!db_info->areas)
302                 return;
303         for (i = 0; i < db_info->nr_areas; i++) {
304                 for(j = 0; j < db_info->pages_per_area; j++) {
305                         kfree(db_info->areas[i][j]);
306                 }
307                 kfree(db_info->areas[i]);
308         }
309         kfree(db_info->areas);
310         db_info->areas = NULL;
311 }
312
313 /*
314  * debug_info_free
315  * - free memory debug-info
316  */
317
318 static void
319 debug_info_free(debug_info_t* db_info){
320         debug_areas_free(db_info);
321         kfree(db_info->active_entries);
322         kfree(db_info->active_pages);
323         kfree(db_info);
324 }
325
326 /*
327  * debug_info_create
328  * - create new debug-info
329  */
330
331 static debug_info_t*
332 debug_info_create(const char *name, int pages_per_area, int nr_areas,
333                   int buf_size, mode_t mode)
334 {
335         debug_info_t* rc;
336
337         rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size,
338                                 DEBUG_DEFAULT_LEVEL, ALL_AREAS);
339         if(!rc) 
340                 goto out;
341
342         rc->mode = mode & ~S_IFMT;
343
344         /* create root directory */
345         rc->debugfs_root_entry = debugfs_create_dir(rc->name,
346                                         debug_debugfs_root_entry);
347
348         /* append new element to linked list */
349         if (!debug_area_first) {
350                 /* first element in list */
351                 debug_area_first = rc;
352                 rc->prev = NULL;
353         } else {
354                 /* append element to end of list */
355                 debug_area_last->next = rc;
356                 rc->prev = debug_area_last;
357         }
358         debug_area_last = rc;
359         rc->next = NULL;
360
361         debug_info_get(rc);
362 out:
363         return rc;
364 }
365
366 /*
367  * debug_info_copy
368  * - copy debug-info
369  */
370
371 static debug_info_t*
372 debug_info_copy(debug_info_t* in, int mode)
373 {
374         int i,j;
375         debug_info_t* rc;
376         unsigned long flags;
377
378         /* get a consistent copy of the debug areas */
379         do {
380                 rc = debug_info_alloc(in->name, in->pages_per_area,
381                         in->nr_areas, in->buf_size, in->level, mode);
382                 spin_lock_irqsave(&in->lock, flags);
383                 if(!rc)
384                         goto out;
385                 /* has something changed in the meantime ? */
386                 if((rc->pages_per_area == in->pages_per_area) &&
387                    (rc->nr_areas == in->nr_areas)) {
388                         break;
389                 }
390                 spin_unlock_irqrestore(&in->lock, flags);
391                 debug_info_free(rc);
392         } while (1);
393
394         if (mode == NO_AREAS)
395                 goto out;
396
397         for(i = 0; i < in->nr_areas; i++){
398                 for(j = 0; j < in->pages_per_area; j++) {
399                         memcpy(rc->areas[i][j], in->areas[i][j],PAGE_SIZE);
400                 }
401         }
402 out:
403         spin_unlock_irqrestore(&in->lock, flags);
404         return rc;
405 }
406
407 /*
408  * debug_info_get
409  * - increments reference count for debug-info
410  */
411
412 static void
413 debug_info_get(debug_info_t * db_info)
414 {
415         if (db_info)
416                 atomic_inc(&db_info->ref_count);
417 }
418
419 /*
420  * debug_info_put:
421  * - decreases reference count for debug-info and frees it if necessary
422  */
423
424 static void
425 debug_info_put(debug_info_t *db_info)
426 {
427         int i;
428
429         if (!db_info)
430                 return;
431         if (atomic_dec_and_test(&db_info->ref_count)) {
432                 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
433                         if (!db_info->views[i])
434                                 continue;
435                         debugfs_remove(db_info->debugfs_entries[i]);
436                 }
437                 debugfs_remove(db_info->debugfs_root_entry);
438                 if(db_info == debug_area_first)
439                         debug_area_first = db_info->next;
440                 if(db_info == debug_area_last)
441                         debug_area_last = db_info->prev;
442                 if(db_info->prev) db_info->prev->next = db_info->next;
443                 if(db_info->next) db_info->next->prev = db_info->prev;
444                 debug_info_free(db_info);
445         }
446 }
447
448 /*
449  * debug_format_entry:
450  * - format one debug entry and return size of formated data
451  */
452
453 static int
454 debug_format_entry(file_private_info_t *p_info)
455 {
456         debug_info_t *id_snap   = p_info->debug_info_snap;
457         struct debug_view *view = p_info->view;
458         debug_entry_t *act_entry;
459         size_t len = 0;
460         if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
461                 /* print prolog */
462                 if (view->prolog_proc)
463                         len += view->prolog_proc(id_snap,view,p_info->temp_buf);
464                 goto out;
465         }
466         if (!id_snap->areas) /* this is true, if we have a prolog only view */
467                 goto out;    /* or if 'pages_per_area' is 0 */
468         act_entry = (debug_entry_t *) ((char*)id_snap->areas[p_info->act_area]
469                                 [p_info->act_page] + p_info->act_entry);
470                         
471         if (act_entry->id.stck == 0LL)
472                         goto out;  /* empty entry */
473         if (view->header_proc)
474                 len += view->header_proc(id_snap, view, p_info->act_area,
475                                         act_entry, p_info->temp_buf + len);
476         if (view->format_proc)
477                 len += view->format_proc(id_snap, view, p_info->temp_buf + len,
478                                                 DEBUG_DATA(act_entry));
479 out:
480         return len;
481 }
482
483 /*
484  * debug_next_entry:
485  * - goto next entry in p_info
486  */
487
488 static inline int
489 debug_next_entry(file_private_info_t *p_info)
490 {
491         debug_info_t *id;
492
493         id = p_info->debug_info_snap;
494         if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
495                 p_info->act_entry = 0;
496                 p_info->act_page  = 0;
497                 goto out;
498         }
499         if(!id->areas)
500                 return 1;
501         p_info->act_entry += id->entry_size;
502         /* switch to next page, if we reached the end of the page  */
503         if (p_info->act_entry > (PAGE_SIZE - id->entry_size)){
504                 /* next page */
505                 p_info->act_entry = 0;
506                 p_info->act_page += 1;
507                 if((p_info->act_page % id->pages_per_area) == 0) {
508                         /* next area */
509                         p_info->act_area++;
510                         p_info->act_page=0;
511                 }
512                 if(p_info->act_area >= id->nr_areas)
513                         return 1;
514         }
515 out:
516         return 0;       
517 }
518
519 /*
520  * debug_output:
521  * - called for user read()
522  * - copies formated debug entries to the user buffer
523  */
524
525 static ssize_t
526 debug_output(struct file *file,         /* file descriptor */
527             char __user *user_buf,      /* user buffer */
528             size_t  len,                /* length of buffer */
529             loff_t *offset)             /* offset in the file */
530 {
531         size_t count = 0;
532         size_t entry_offset;
533         file_private_info_t *p_info;
534
535         p_info = ((file_private_info_t *) file->private_data);
536         if (*offset != p_info->offset) 
537                 return -EPIPE;
538         if(p_info->act_area >= p_info->debug_info_snap->nr_areas)
539                 return 0;
540         entry_offset = p_info->act_entry_offset;
541         while(count < len){
542                 int formatted_line_size;
543                 int formatted_line_residue;
544                 int user_buf_residue;
545                 size_t copy_size;
546
547                 formatted_line_size = debug_format_entry(p_info);
548                 formatted_line_residue = formatted_line_size - entry_offset;
549                 user_buf_residue = len-count;
550                 copy_size = min(user_buf_residue, formatted_line_residue);
551                 if(copy_size){
552                         if (copy_to_user(user_buf + count, p_info->temp_buf
553                                         + entry_offset, copy_size))
554                                 return -EFAULT;
555                         count += copy_size;
556                         entry_offset += copy_size;
557                 }
558                 if(copy_size == formatted_line_residue){
559                         entry_offset = 0;
560                         if(debug_next_entry(p_info))
561                                 goto out;
562                 }
563         }
564 out:
565         p_info->offset           = *offset + count;
566         p_info->act_entry_offset = entry_offset;
567         *offset = p_info->offset;
568         return count;
569 }
570
571 /*
572  * debug_input:
573  * - called for user write()
574  * - calls input function of view
575  */
576
577 static ssize_t
578 debug_input(struct file *file, const char __user *user_buf, size_t length,
579                 loff_t *offset)
580 {
581         int rc = 0;
582         file_private_info_t *p_info;
583
584         mutex_lock(&debug_mutex);
585         p_info = ((file_private_info_t *) file->private_data);
586         if (p_info->view->input_proc)
587                 rc = p_info->view->input_proc(p_info->debug_info_org,
588                                               p_info->view, file, user_buf,
589                                               length, offset);
590         else
591                 rc = -EPERM;
592         mutex_unlock(&debug_mutex);
593         return rc;              /* number of input characters */
594 }
595
596 /*
597  * debug_open:
598  * - called for user open()
599  * - copies formated output to private_data area of the file
600  *   handle
601  */
602
603 static int
604 debug_open(struct inode *inode, struct file *file)
605 {
606         int i, rc = 0;
607         file_private_info_t *p_info;
608         debug_info_t *debug_info, *debug_info_snapshot;
609
610         mutex_lock(&debug_mutex);
611         debug_info = file->f_path.dentry->d_inode->i_private;
612         /* find debug view */
613         for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
614                 if (!debug_info->views[i])
615                         continue;
616                 else if (debug_info->debugfs_entries[i] ==
617                          file->f_path.dentry) {
618                         goto found;     /* found view ! */
619                 }
620         }
621         /* no entry found */
622         rc = -EINVAL;
623         goto out;
624
625 found:
626
627         /* Make snapshot of current debug areas to get it consistent.     */
628         /* To copy all the areas is only needed, if we have a view which  */
629         /* formats the debug areas. */
630
631         if(!debug_info->views[i]->format_proc &&
632                 !debug_info->views[i]->header_proc){
633                 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS);
634         } else {
635                 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS);
636         }
637
638         if(!debug_info_snapshot){
639                 rc = -ENOMEM;
640                 goto out;
641         }
642         p_info = kmalloc(sizeof(file_private_info_t),
643                                                 GFP_KERNEL);
644         if(!p_info){
645                 debug_info_free(debug_info_snapshot);
646                 rc = -ENOMEM;
647                 goto out;
648         }
649         p_info->offset = 0;
650         p_info->debug_info_snap = debug_info_snapshot;
651         p_info->debug_info_org  = debug_info;
652         p_info->view = debug_info->views[i];
653         p_info->act_area = 0;
654         p_info->act_page = 0;
655         p_info->act_entry = DEBUG_PROLOG_ENTRY;
656         p_info->act_entry_offset = 0;
657         file->private_data = p_info;
658         debug_info_get(debug_info);
659         nonseekable_open(inode, file);
660 out:
661         mutex_unlock(&debug_mutex);
662         return rc;
663 }
664
665 /*
666  * debug_close:
667  * - called for user close()
668  * - deletes  private_data area of the file handle
669  */
670
671 static int
672 debug_close(struct inode *inode, struct file *file)
673 {
674         file_private_info_t *p_info;
675         p_info = (file_private_info_t *) file->private_data;
676         if(p_info->debug_info_snap)
677                 debug_info_free(p_info->debug_info_snap);
678         debug_info_put(p_info->debug_info_org);
679         kfree(file->private_data);
680         return 0;               /* success */
681 }
682
683 /*
684  * debug_register_mode:
685  * - Creates and initializes debug area for the caller
686  *   The mode parameter allows to specify access rights for the s390dbf files
687  * - Returns handle for debug area
688  */
689
690 debug_info_t *debug_register_mode(const char *name, int pages_per_area,
691                                   int nr_areas, int buf_size, mode_t mode,
692                                   uid_t uid, gid_t gid)
693 {
694         debug_info_t *rc = NULL;
695
696         /* Since debugfs currently does not support uid/gid other than root, */
697         /* we do not allow gid/uid != 0 until we get support for that. */
698         if ((uid != 0) || (gid != 0))
699                 pr_warning("Root becomes the owner of all s390dbf files "
700                            "in sysfs\n");
701         BUG_ON(!initialized);
702         mutex_lock(&debug_mutex);
703
704         /* create new debug_info */
705
706         rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
707         if(!rc) 
708                 goto out;
709         debug_register_view(rc, &debug_level_view);
710         debug_register_view(rc, &debug_flush_view);
711         debug_register_view(rc, &debug_pages_view);
712 out:
713         if (!rc){
714                 pr_err("Registering debug feature %s failed\n", name);
715         }
716         mutex_unlock(&debug_mutex);
717         return rc;
718 }
719 EXPORT_SYMBOL(debug_register_mode);
720
721 /*
722  * debug_register:
723  * - creates and initializes debug area for the caller
724  * - returns handle for debug area
725  */
726
727 debug_info_t *debug_register(const char *name, int pages_per_area,
728                              int nr_areas, int buf_size)
729 {
730         return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
731                                    S_IRUSR | S_IWUSR, 0, 0);
732 }
733
734 /*
735  * debug_unregister:
736  * - give back debug area
737  */
738
739 void
740 debug_unregister(debug_info_t * id)
741 {
742         if (!id)
743                 goto out;
744         mutex_lock(&debug_mutex);
745         debug_info_put(id);
746         mutex_unlock(&debug_mutex);
747
748 out:
749         return;
750 }
751
752 /*
753  * debug_set_size:
754  * - set area size (number of pages) and number of areas
755  */
756 static int
757 debug_set_size(debug_info_t* id, int nr_areas, int pages_per_area)
758 {
759         unsigned long flags;
760         debug_entry_t *** new_areas;
761         int rc=0;
762
763         if(!id || (nr_areas <= 0) || (pages_per_area < 0))
764                 return -EINVAL;
765         if(pages_per_area > 0){
766                 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
767                 if(!new_areas) {
768                         pr_info("Allocating memory for %i pages failed\n",
769                                 pages_per_area);
770                         rc = -ENOMEM;
771                         goto out;
772                 }
773         } else {
774                 new_areas = NULL;
775         }
776         spin_lock_irqsave(&id->lock,flags);
777         debug_areas_free(id);
778         id->areas = new_areas;
779         id->nr_areas = nr_areas;
780         id->pages_per_area = pages_per_area;
781         id->active_area = 0;
782         memset(id->active_entries,0,sizeof(int)*id->nr_areas);
783         memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
784         spin_unlock_irqrestore(&id->lock,flags);
785         pr_info("%s: set new size (%i pages)\n" ,id->name, pages_per_area);
786 out:
787         return rc;
788 }
789
790 /*
791  * debug_set_level:
792  * - set actual debug level
793  */
794
795 void
796 debug_set_level(debug_info_t* id, int new_level)
797 {
798         unsigned long flags;
799         if(!id)
800                 return; 
801         spin_lock_irqsave(&id->lock,flags);
802         if(new_level == DEBUG_OFF_LEVEL){
803                 id->level = DEBUG_OFF_LEVEL;
804                 pr_info("%s: switched off\n",id->name);
805         } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
806                 pr_info("%s: level %i is out of range (%i - %i)\n",
807                         id->name, new_level, 0, DEBUG_MAX_LEVEL);
808         } else {
809                 id->level = new_level;
810         }
811         spin_unlock_irqrestore(&id->lock,flags);
812 }
813
814
815 /*
816  * proceed_active_entry:
817  * - set active entry to next in the ring buffer
818  */
819
820 static inline void
821 proceed_active_entry(debug_info_t * id)
822 {
823         if ((id->active_entries[id->active_area] += id->entry_size)
824             > (PAGE_SIZE - id->entry_size)){
825                 id->active_entries[id->active_area] = 0;
826                 id->active_pages[id->active_area] =
827                         (id->active_pages[id->active_area] + 1) %
828                         id->pages_per_area;
829         }
830 }
831
832 /*
833  * proceed_active_area:
834  * - set active area to next in the ring buffer
835  */
836
837 static inline void
838 proceed_active_area(debug_info_t * id)
839 {
840         id->active_area++;
841         id->active_area = id->active_area % id->nr_areas;
842 }
843
844 /*
845  * get_active_entry:
846  */
847
848 static inline debug_entry_t*
849 get_active_entry(debug_info_t * id)
850 {
851         return (debug_entry_t *) (((char *) id->areas[id->active_area]
852                                         [id->active_pages[id->active_area]]) +
853                                         id->active_entries[id->active_area]);
854 }
855
856 /*
857  * debug_finish_entry:
858  * - set timestamp, caller address, cpu number etc.
859  */
860
861 static inline void
862 debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level,
863                         int exception)
864 {
865         active->id.stck = get_clock();
866         active->id.fields.cpuid = smp_processor_id();
867         active->caller = __builtin_return_address(0);
868         active->id.fields.exception = exception;
869         active->id.fields.level     = level;
870         proceed_active_entry(id);
871         if(exception)
872                 proceed_active_area(id);
873 }
874
875 static int debug_stoppable=1;
876 static int debug_active=1;
877
878 #define CTL_S390DBF_STOPPABLE 5678
879 #define CTL_S390DBF_ACTIVE 5679
880
881 /*
882  * proc handler for the running debug_active sysctl
883  * always allow read, allow write only if debug_stoppable is set or
884  * if debug_active is already off
885  */
886 static int
887 s390dbf_procactive(ctl_table *table, int write,
888                      void __user *buffer, size_t *lenp, loff_t *ppos)
889 {
890         if (!write || debug_stoppable || !debug_active)
891                 return proc_dointvec(table, write, buffer, lenp, ppos);
892         else
893                 return 0;
894 }
895
896
897 static struct ctl_table s390dbf_table[] = {
898         {
899                 .procname       = "debug_stoppable",
900                 .data           = &debug_stoppable,
901                 .maxlen         = sizeof(int),
902                 .mode           = S_IRUGO | S_IWUSR,
903                 .proc_handler   = proc_dointvec,
904         },
905          {
906                 .procname       = "debug_active",
907                 .data           = &debug_active,
908                 .maxlen         = sizeof(int),
909                 .mode           = S_IRUGO | S_IWUSR,
910                 .proc_handler   = s390dbf_procactive,
911         },
912         { }
913 };
914
915 static struct ctl_table s390dbf_dir_table[] = {
916         {
917                 .procname       = "s390dbf",
918                 .maxlen         = 0,
919                 .mode           = S_IRUGO | S_IXUGO,
920                 .child          = s390dbf_table,
921         },
922         { }
923 };
924
925 static struct ctl_table_header *s390dbf_sysctl_header;
926
927 void
928 debug_stop_all(void)
929 {
930         if (debug_stoppable)
931                 debug_active = 0;
932 }
933
934
935 /*
936  * debug_event_common:
937  * - write debug entry with given size
938  */
939
940 debug_entry_t*
941 debug_event_common(debug_info_t * id, int level, const void *buf, int len)
942 {
943         unsigned long flags;
944         debug_entry_t *active;
945
946         if (!debug_active || !id->areas)
947                 return NULL;
948         spin_lock_irqsave(&id->lock, flags);
949         active = get_active_entry(id);
950         memset(DEBUG_DATA(active), 0, id->buf_size);
951         memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
952         debug_finish_entry(id, active, level, 0);
953         spin_unlock_irqrestore(&id->lock, flags);
954
955         return active;
956 }
957
958 /*
959  * debug_exception_common:
960  * - write debug entry with given size and switch to next debug area
961  */
962
963 debug_entry_t
964 *debug_exception_common(debug_info_t * id, int level, const void *buf, int len)
965 {
966         unsigned long flags;
967         debug_entry_t *active;
968
969         if (!debug_active || !id->areas)
970                 return NULL;
971         spin_lock_irqsave(&id->lock, flags);
972         active = get_active_entry(id);
973         memset(DEBUG_DATA(active), 0, id->buf_size);
974         memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
975         debug_finish_entry(id, active, level, 1);
976         spin_unlock_irqrestore(&id->lock, flags);
977
978         return active;
979 }
980
981 /*
982  * counts arguments in format string for sprintf view
983  */
984
985 static inline int
986 debug_count_numargs(char *string)
987 {
988         int numargs=0;
989
990         while(*string) {
991                 if(*string++=='%')
992                         numargs++;
993         }
994         return(numargs);
995 }
996
997 /*
998  * debug_sprintf_event:
999  */
1000
1001 debug_entry_t*
1002 debug_sprintf_event(debug_info_t* id, int level,char *string,...)
1003 {
1004         va_list   ap;
1005         int numargs,idx;
1006         unsigned long flags;
1007         debug_sprintf_entry_t *curr_event;
1008         debug_entry_t *active;
1009
1010         if((!id) || (level > id->level))
1011                 return NULL;
1012         if (!debug_active || !id->areas)
1013                 return NULL;
1014         numargs=debug_count_numargs(string);
1015
1016         spin_lock_irqsave(&id->lock, flags);
1017         active = get_active_entry(id);
1018         curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active);
1019         va_start(ap,string);
1020         curr_event->string=string;
1021         for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1022                 curr_event->args[idx]=va_arg(ap,long);
1023         va_end(ap);
1024         debug_finish_entry(id, active, level, 0);
1025         spin_unlock_irqrestore(&id->lock, flags);
1026
1027         return active;
1028 }
1029
1030 /*
1031  * debug_sprintf_exception:
1032  */
1033
1034 debug_entry_t*
1035 debug_sprintf_exception(debug_info_t* id, int level,char *string,...)
1036 {
1037         va_list   ap;
1038         int numargs,idx;
1039         unsigned long flags;
1040         debug_sprintf_entry_t *curr_event;
1041         debug_entry_t *active;
1042
1043         if((!id) || (level > id->level))
1044                 return NULL;
1045         if (!debug_active || !id->areas)
1046                 return NULL;
1047
1048         numargs=debug_count_numargs(string);
1049
1050         spin_lock_irqsave(&id->lock, flags);
1051         active = get_active_entry(id);
1052         curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active);
1053         va_start(ap,string);
1054         curr_event->string=string;
1055         for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1056                 curr_event->args[idx]=va_arg(ap,long);
1057         va_end(ap);
1058         debug_finish_entry(id, active, level, 1);
1059         spin_unlock_irqrestore(&id->lock, flags);
1060
1061         return active;
1062 }
1063
1064 /*
1065  * debug_init:
1066  * - is called exactly once to initialize the debug feature
1067  */
1068
1069 static int
1070 __init debug_init(void)
1071 {
1072         int rc = 0;
1073
1074         s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1075         mutex_lock(&debug_mutex);
1076         debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT,NULL);
1077         initialized = 1;
1078         mutex_unlock(&debug_mutex);
1079
1080         return rc;
1081 }
1082
1083 /*
1084  * debug_register_view:
1085  */
1086
1087 int
1088 debug_register_view(debug_info_t * id, struct debug_view *view)
1089 {
1090         int rc = 0;
1091         int i;
1092         unsigned long flags;
1093         mode_t mode;
1094         struct dentry *pde;
1095
1096         if (!id)
1097                 goto out;
1098         mode = (id->mode | S_IFREG) & ~S_IXUGO;
1099         if (!(view->prolog_proc || view->format_proc || view->header_proc))
1100                 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1101         if (!view->input_proc)
1102                 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1103         pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1104                                 id , &debug_file_ops);
1105         if (!pde){
1106                 pr_err("Registering view %s/%s failed due to out of "
1107                        "memory\n", id->name,view->name);
1108                 rc = -1;
1109                 goto out;
1110         }
1111         spin_lock_irqsave(&id->lock, flags);
1112         for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1113                 if (!id->views[i])
1114                         break;
1115         }
1116         if (i == DEBUG_MAX_VIEWS) {
1117                 pr_err("Registering view %s/%s would exceed the maximum "
1118                        "number of views %i\n", id->name, view->name, i);
1119                 debugfs_remove(pde);
1120                 rc = -1;
1121         } else {
1122                 id->views[i] = view;
1123                 id->debugfs_entries[i] = pde;
1124         }
1125         spin_unlock_irqrestore(&id->lock, flags);
1126 out:
1127         return rc;
1128 }
1129
1130 /*
1131  * debug_unregister_view:
1132  */
1133
1134 int
1135 debug_unregister_view(debug_info_t * id, struct debug_view *view)
1136 {
1137         int rc = 0;
1138         int i;
1139         unsigned long flags;
1140
1141         if (!id)
1142                 goto out;
1143         spin_lock_irqsave(&id->lock, flags);
1144         for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1145                 if (id->views[i] == view)
1146                         break;
1147         }
1148         if (i == DEBUG_MAX_VIEWS)
1149                 rc = -1;
1150         else {
1151                 debugfs_remove(id->debugfs_entries[i]);
1152                 id->views[i] = NULL;
1153         }
1154         spin_unlock_irqrestore(&id->lock, flags);
1155 out:
1156         return rc;
1157 }
1158
1159 static inline char *
1160 debug_get_user_string(const char __user *user_buf, size_t user_len)
1161 {
1162         char* buffer;
1163
1164         buffer = kmalloc(user_len + 1, GFP_KERNEL);
1165         if (!buffer)
1166                 return ERR_PTR(-ENOMEM);
1167         if (copy_from_user(buffer, user_buf, user_len) != 0) {
1168                 kfree(buffer);
1169                 return ERR_PTR(-EFAULT);
1170         }
1171         /* got the string, now strip linefeed. */
1172         if (buffer[user_len - 1] == '\n')
1173                 buffer[user_len - 1] = 0;
1174         else
1175                 buffer[user_len] = 0;
1176         return buffer;
1177 }
1178
1179 static inline int
1180 debug_get_uint(char *buf)
1181 {
1182         int rc;
1183
1184         buf = skip_spaces(buf);
1185         rc = simple_strtoul(buf, &buf, 10);
1186         if(*buf){
1187                 rc = -EINVAL;
1188         }
1189         return rc;
1190 }
1191
1192 /*
1193  * functions for debug-views
1194  ***********************************
1195 */
1196
1197 /*
1198  * prints out actual debug level
1199  */
1200
1201 static int
1202 debug_prolog_pages_fn(debug_info_t * id,
1203                                  struct debug_view *view, char *out_buf)
1204 {
1205         return sprintf(out_buf, "%i\n", id->pages_per_area);
1206 }
1207
1208 /*
1209  * reads new size (number of pages per debug area)
1210  */
1211
1212 static int
1213 debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
1214                         struct file *file, const char __user *user_buf,
1215                         size_t user_len, loff_t * offset)
1216 {
1217         char *str;
1218         int rc,new_pages;
1219
1220         if (user_len > 0x10000)
1221                 user_len = 0x10000;
1222         if (*offset != 0){
1223                 rc = -EPIPE;
1224                 goto out;
1225         }
1226         str = debug_get_user_string(user_buf,user_len);
1227         if(IS_ERR(str)){
1228                 rc = PTR_ERR(str);
1229                 goto out;
1230         }
1231         new_pages = debug_get_uint(str);
1232         if(new_pages < 0){
1233                 rc = -EINVAL;
1234                 goto free_str;
1235         }
1236         rc = debug_set_size(id,id->nr_areas, new_pages);
1237         if(rc != 0){
1238                 rc = -EINVAL;
1239                 goto free_str;
1240         }
1241         rc = user_len;
1242 free_str:
1243         kfree(str);
1244 out:
1245         *offset += user_len;
1246         return rc;              /* number of input characters */
1247 }
1248
1249 /*
1250  * prints out actual debug level
1251  */
1252
1253 static int
1254 debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf)
1255 {
1256         int rc = 0;
1257
1258         if(id->level == DEBUG_OFF_LEVEL) {
1259                 rc = sprintf(out_buf,"-\n");
1260         }
1261         else {
1262                 rc = sprintf(out_buf, "%i\n", id->level);
1263         }
1264         return rc;
1265 }
1266
1267 /*
1268  * reads new debug level
1269  */
1270
1271 static int
1272 debug_input_level_fn(debug_info_t * id, struct debug_view *view,
1273                         struct file *file, const char __user *user_buf,
1274                         size_t user_len, loff_t * offset)
1275 {
1276         char *str;
1277         int rc,new_level;
1278
1279         if (user_len > 0x10000)
1280                 user_len = 0x10000;
1281         if (*offset != 0){
1282                 rc = -EPIPE;
1283                 goto out;
1284         }
1285         str = debug_get_user_string(user_buf,user_len);
1286         if(IS_ERR(str)){
1287                 rc = PTR_ERR(str);
1288                 goto out;
1289         }
1290         if(str[0] == '-'){
1291                 debug_set_level(id, DEBUG_OFF_LEVEL);
1292                 rc = user_len;
1293                 goto free_str;
1294         } else {
1295                 new_level = debug_get_uint(str);
1296         }
1297         if(new_level < 0) {
1298                 pr_warning("%s is not a valid level for a debug "
1299                            "feature\n", str);
1300                 rc = -EINVAL;
1301         } else {
1302                 debug_set_level(id, new_level);
1303                 rc = user_len;
1304         }
1305 free_str:
1306         kfree(str);
1307 out:
1308         *offset += user_len;
1309         return rc;              /* number of input characters */
1310 }
1311
1312
1313 /*
1314  * flushes debug areas
1315  */
1316  
1317 static void debug_flush(debug_info_t* id, int area)
1318 {
1319         unsigned long flags;
1320         int i,j;
1321
1322         if(!id || !id->areas)
1323                 return;
1324         spin_lock_irqsave(&id->lock,flags);
1325         if(area == DEBUG_FLUSH_ALL){
1326                 id->active_area = 0;
1327                 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1328                 for (i = 0; i < id->nr_areas; i++) {
1329                         id->active_pages[i] = 0;
1330                         for(j = 0; j < id->pages_per_area; j++) {
1331                                 memset(id->areas[i][j], 0, PAGE_SIZE);
1332                         }
1333                 }
1334         } else if(area >= 0 && area < id->nr_areas) {
1335                 id->active_entries[area] = 0;
1336                 id->active_pages[area] = 0;
1337                 for(i = 0; i < id->pages_per_area; i++) {
1338                         memset(id->areas[area][i],0,PAGE_SIZE);
1339                 }
1340         }
1341         spin_unlock_irqrestore(&id->lock,flags);
1342 }
1343
1344 /*
1345  * view function: flushes debug areas 
1346  */
1347
1348 static int
1349 debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
1350                         struct file *file, const char __user *user_buf,
1351                         size_t user_len, loff_t * offset)
1352 {
1353         char input_buf[1];
1354         int rc = user_len;
1355
1356         if (user_len > 0x10000)
1357                 user_len = 0x10000;
1358         if (*offset != 0){
1359                 rc = -EPIPE;
1360                 goto out;
1361         }
1362         if (copy_from_user(input_buf, user_buf, 1)){
1363                 rc = -EFAULT;
1364                 goto out;
1365         }
1366         if(input_buf[0] == '-') { 
1367                 debug_flush(id, DEBUG_FLUSH_ALL);
1368                 goto out;
1369         }
1370         if (isdigit(input_buf[0])) {
1371                 int area = ((int) input_buf[0] - (int) '0');
1372                 debug_flush(id, area);
1373                 goto out;
1374         }
1375
1376         pr_info("Flushing debug data failed because %c is not a valid "
1377                  "area\n", input_buf[0]);
1378
1379 out:
1380         *offset += user_len;
1381         return rc;              /* number of input characters */
1382 }
1383
1384 /*
1385  * prints debug header in raw format
1386  */
1387
1388 static int
1389 debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
1390                         int area, debug_entry_t * entry, char *out_buf)
1391 {
1392         int rc;
1393
1394         rc = sizeof(debug_entry_t);
1395         memcpy(out_buf,entry,sizeof(debug_entry_t));
1396         return rc;
1397 }
1398
1399 /*
1400  * prints debug data in raw format
1401  */
1402
1403 static int
1404 debug_raw_format_fn(debug_info_t * id, struct debug_view *view,
1405                                char *out_buf, const char *in_buf)
1406 {
1407         int rc;
1408
1409         rc = id->buf_size;
1410         memcpy(out_buf, in_buf, id->buf_size);
1411         return rc;
1412 }
1413
1414 /*
1415  * prints debug data in hex/ascii format
1416  */
1417
1418 static int
1419 debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
1420                           char *out_buf, const char *in_buf)
1421 {
1422         int i, rc = 0;
1423
1424         for (i = 0; i < id->buf_size; i++) {
1425                 rc += sprintf(out_buf + rc, "%02x ",
1426                               ((unsigned char *) in_buf)[i]);
1427         }
1428         rc += sprintf(out_buf + rc, "| ");
1429         for (i = 0; i < id->buf_size; i++) {
1430                 unsigned char c = in_buf[i];
1431                 if (!isprint(c))
1432                         rc += sprintf(out_buf + rc, ".");
1433                 else
1434                         rc += sprintf(out_buf + rc, "%c", c);
1435         }
1436         rc += sprintf(out_buf + rc, "\n");
1437         return rc;
1438 }
1439
1440 /*
1441  * prints header for debug entry
1442  */
1443
1444 int
1445 debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
1446                          int area, debug_entry_t * entry, char *out_buf)
1447 {
1448         struct timespec time_spec;
1449         char *except_str;
1450         unsigned long caller;
1451         int rc = 0;
1452         unsigned int level;
1453
1454         level = entry->id.fields.level;
1455         stck_to_timespec(entry->id.stck, &time_spec);
1456
1457         if (entry->id.fields.exception)
1458                 except_str = "*";
1459         else
1460                 except_str = "-";
1461         caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN;
1462         rc += sprintf(out_buf, "%02i %011lu:%06lu %1u %1s %02i %p  ",
1463                       area, time_spec.tv_sec, time_spec.tv_nsec / 1000, level,
1464                       except_str, entry->id.fields.cpuid, (void *) caller);
1465         return rc;
1466 }
1467
1468 /*
1469  * prints debug data sprintf-formated:
1470  * debug_sprinf_event/exception calls must be used together with this view
1471  */
1472
1473 #define DEBUG_SPRINTF_MAX_ARGS 10
1474
1475 static int
1476 debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
1477                         char *out_buf, debug_sprintf_entry_t *curr_event)
1478 {
1479         int num_longs, num_used_args = 0,i, rc = 0;
1480         int index[DEBUG_SPRINTF_MAX_ARGS];
1481
1482         /* count of longs fit into one entry */
1483         num_longs = id->buf_size /  sizeof(long); 
1484
1485         if(num_longs < 1)
1486                 goto out; /* bufsize of entry too small */
1487         if(num_longs == 1) {
1488                 /* no args, we use only the string */
1489                 strcpy(out_buf, curr_event->string);
1490                 rc = strlen(curr_event->string);
1491                 goto out;
1492         }
1493
1494         /* number of arguments used for sprintf (without the format string) */
1495         num_used_args   = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1496
1497         memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1498
1499         for(i = 0; i < num_used_args; i++)
1500                 index[i] = i;
1501
1502         rc =  sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1503                 curr_event->args[index[1]], curr_event->args[index[2]],
1504                 curr_event->args[index[3]], curr_event->args[index[4]],
1505                 curr_event->args[index[5]], curr_event->args[index[6]],
1506                 curr_event->args[index[7]], curr_event->args[index[8]],
1507                 curr_event->args[index[9]]);
1508
1509 out:
1510
1511         return rc;
1512 }
1513
1514 /*
1515  * clean up module
1516  */
1517 static void __exit debug_exit(void)
1518 {
1519         debugfs_remove(debug_debugfs_root_entry);
1520         unregister_sysctl_table(s390dbf_sysctl_header);
1521         return;
1522 }
1523
1524 /*
1525  * module definitions
1526  */
1527 postcore_initcall(debug_init);
1528 module_exit(debug_exit);
1529 MODULE_LICENSE("GPL");
1530
1531 EXPORT_SYMBOL(debug_register);
1532 EXPORT_SYMBOL(debug_unregister); 
1533 EXPORT_SYMBOL(debug_set_level);
1534 EXPORT_SYMBOL(debug_stop_all);
1535 EXPORT_SYMBOL(debug_register_view);
1536 EXPORT_SYMBOL(debug_unregister_view);
1537 EXPORT_SYMBOL(debug_event_common);
1538 EXPORT_SYMBOL(debug_exception_common);
1539 EXPORT_SYMBOL(debug_hex_ascii_view);
1540 EXPORT_SYMBOL(debug_raw_view);
1541 EXPORT_SYMBOL(debug_dflt_header_fn);
1542 EXPORT_SYMBOL(debug_sprintf_view);
1543 EXPORT_SYMBOL(debug_sprintf_exception);
1544 EXPORT_SYMBOL(debug_sprintf_event);