Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6
[linux-2.6] / drivers / s390 / char / monreader.c
1 /*
2  * drivers/s390/char/monreader.c
3  *
4  * Character device driver for reading z/VM *MONITOR service records.
5  *
6  * Copyright (C) 2004 IBM Corporation, IBM Deutschland Entwicklung GmbH.
7  *
8  * Author: Gerald Schaefer <geraldsc@de.ibm.com>
9  */
10
11 #include <linux/module.h>
12 #include <linux/moduleparam.h>
13 #include <linux/init.h>
14 #include <linux/errno.h>
15 #include <linux/types.h>
16 #include <linux/kernel.h>
17 #include <linux/miscdevice.h>
18 #include <linux/ctype.h>
19 #include <linux/spinlock.h>
20 #include <linux/interrupt.h>
21 #include <asm/uaccess.h>
22 #include <asm/ebcdic.h>
23 #include <asm/extmem.h>
24 #include <linux/poll.h>
25 #include "../net/iucv.h"
26
27
28 //#define MON_DEBUG                     /* Debug messages on/off */
29
30 #define MON_NAME "monreader"
31
32 #define P_INFO(x...)    printk(KERN_INFO MON_NAME " info: " x)
33 #define P_ERROR(x...)   printk(KERN_ERR MON_NAME " error: " x)
34 #define P_WARNING(x...) printk(KERN_WARNING MON_NAME " warning: " x)
35
36 #ifdef MON_DEBUG
37 #define P_DEBUG(x...)   printk(KERN_DEBUG MON_NAME " debug: " x)
38 #else
39 #define P_DEBUG(x...)   do {} while (0)
40 #endif
41
42 #define MON_COLLECT_SAMPLE 0x80
43 #define MON_COLLECT_EVENT  0x40
44 #define MON_SERVICE        "*MONITOR"
45 #define MON_IN_USE         0x01
46 #define MON_MSGLIM         255
47
48 static char mon_dcss_name[9] = "MONDCSS\0";
49
50 struct mon_msg {
51         u32 pos;
52         u32 mca_offset;
53         iucv_MessagePending local_eib;
54         char msglim_reached;
55         char replied_msglim;
56 };
57
58 struct mon_private {
59         u16 pathid;
60         iucv_handle_t iucv_handle;
61         struct mon_msg *msg_array[MON_MSGLIM];
62         unsigned int   write_index;
63         unsigned int   read_index;
64         atomic_t msglim_count;
65         atomic_t read_ready;
66         atomic_t iucv_connected;
67         atomic_t iucv_severed;
68 };
69
70 static unsigned long mon_in_use = 0;
71
72 static unsigned long mon_dcss_start;
73 static unsigned long mon_dcss_end;
74
75 static DECLARE_WAIT_QUEUE_HEAD(mon_read_wait_queue);
76 static DECLARE_WAIT_QUEUE_HEAD(mon_conn_wait_queue);
77
78 static u8 iucv_host[8] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
79
80 static u8 user_data_connect[16] = {
81         /* Version code, must be 0x01 for shared mode */
82         0x01,
83         /* what to collect */
84         MON_COLLECT_SAMPLE | MON_COLLECT_EVENT,
85         /* DCSS name in EBCDIC, 8 bytes padded with blanks */
86         0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
87         0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
88 };
89
90 static u8 user_data_sever[16] = {
91         0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
92         0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
93 };
94
95
96 /******************************************************************************
97  *                             helper functions                               *
98  *****************************************************************************/
99 /*
100  * Create the 8 bytes EBCDIC DCSS segment name from
101  * an ASCII name, incl. padding
102  */
103 static inline void
104 dcss_mkname(char *ascii_name, char *ebcdic_name)
105 {
106         int i;
107
108         for (i = 0; i < 8; i++) {
109                 if (ascii_name[i] == '\0')
110                         break;
111                 ebcdic_name[i] = toupper(ascii_name[i]);
112         };
113         for (; i < 8; i++)
114                 ebcdic_name[i] = ' ';
115         ASCEBC(ebcdic_name, 8);
116 }
117
118 /*
119  * print appropriate error message for segment_load()/segment_type()
120  * return code
121  */
122 static void
123 mon_segment_warn(int rc, char* seg_name)
124 {
125         switch (rc) {
126         case -ENOENT:
127                 P_WARNING("cannot load/query segment %s, does not exist\n",
128                           seg_name);
129                 break;
130         case -ENOSYS:
131                 P_WARNING("cannot load/query segment %s, not running on VM\n",
132                           seg_name);
133                 break;
134         case -EIO:
135                 P_WARNING("cannot load/query segment %s, hardware error\n",
136                           seg_name);
137                 break;
138         case -ENOTSUPP:
139                 P_WARNING("cannot load/query segment %s, is a multi-part "
140                           "segment\n", seg_name);
141                 break;
142         case -ENOSPC:
143                 P_WARNING("cannot load/query segment %s, overlaps with "
144                           "storage\n", seg_name);
145                 break;
146         case -EBUSY:
147                 P_WARNING("cannot load/query segment %s, overlaps with "
148                           "already loaded dcss\n", seg_name);
149                 break;
150         case -EPERM:
151                 P_WARNING("cannot load/query segment %s, already loaded in "
152                           "incompatible mode\n", seg_name);
153                 break;
154         case -ENOMEM:
155                 P_WARNING("cannot load/query segment %s, out of memory\n",
156                           seg_name);
157                 break;
158         case -ERANGE:
159                 P_WARNING("cannot load/query segment %s, exceeds kernel "
160                           "mapping range\n", seg_name);
161                 break;
162         default:
163                 P_WARNING("cannot load/query segment %s, return value %i\n",
164                           seg_name, rc);
165                 break;
166         }
167 }
168
169 static inline unsigned long
170 mon_mca_start(struct mon_msg *monmsg)
171 {
172         return monmsg->local_eib.ln1msg1.iprmmsg1_u32;
173 }
174
175 static inline unsigned long
176 mon_mca_end(struct mon_msg *monmsg)
177 {
178         return monmsg->local_eib.ln1msg2.ipbfln1f;
179 }
180
181 static inline u8
182 mon_mca_type(struct mon_msg *monmsg, u8 index)
183 {
184         return *((u8 *) mon_mca_start(monmsg) + monmsg->mca_offset + index);
185 }
186
187 static inline u32
188 mon_mca_size(struct mon_msg *monmsg)
189 {
190         return mon_mca_end(monmsg) - mon_mca_start(monmsg) + 1;
191 }
192
193 static inline u32
194 mon_rec_start(struct mon_msg *monmsg)
195 {
196         return *((u32 *) (mon_mca_start(monmsg) + monmsg->mca_offset + 4));
197 }
198
199 static inline u32
200 mon_rec_end(struct mon_msg *monmsg)
201 {
202         return *((u32 *) (mon_mca_start(monmsg) + monmsg->mca_offset + 8));
203 }
204
205 static inline int
206 mon_check_mca(struct mon_msg *monmsg)
207 {
208         if ((mon_rec_end(monmsg) <= mon_rec_start(monmsg)) ||
209             (mon_rec_start(monmsg) < mon_dcss_start) ||
210             (mon_rec_end(monmsg) > mon_dcss_end) ||
211             (mon_mca_type(monmsg, 0) == 0) ||
212             (mon_mca_size(monmsg) % 12 != 0) ||
213             (mon_mca_end(monmsg) <= mon_mca_start(monmsg)) ||
214             (mon_mca_end(monmsg) > mon_dcss_end) ||
215             (mon_mca_start(monmsg) < mon_dcss_start) ||
216             ((mon_mca_type(monmsg, 1) == 0) && (mon_mca_type(monmsg, 2) == 0)))
217         {
218                 P_DEBUG("READ, IGNORED INVALID MCA\n\n");
219                 return -EINVAL;
220         }
221         return 0;
222 }
223
224 static inline int
225 mon_send_reply(struct mon_msg *monmsg, struct mon_private *monpriv)
226 {
227         u8 prmmsg[8];
228         int rc;
229
230         P_DEBUG("read, REPLY: pathid = 0x%04X, msgid = 0x%08X, trgcls = "
231                 "0x%08X\n\n",
232                 monmsg->local_eib.ippathid, monmsg->local_eib.ipmsgid,
233                 monmsg->local_eib.iptrgcls);
234         rc = iucv_reply_prmmsg(monmsg->local_eib.ippathid,
235                                 monmsg->local_eib.ipmsgid,
236                                 monmsg->local_eib.iptrgcls,
237                                 0, prmmsg);
238         atomic_dec(&monpriv->msglim_count);
239         if (likely(!monmsg->msglim_reached)) {
240                 monmsg->pos = 0;
241                 monmsg->mca_offset = 0;
242                 monpriv->read_index = (monpriv->read_index + 1) %
243                                       MON_MSGLIM;
244                 atomic_dec(&monpriv->read_ready);
245         } else
246                 monmsg->replied_msglim = 1;
247         if (rc) {
248                 P_ERROR("read, IUCV reply failed with rc = %i\n\n", rc);
249                 return -EIO;
250         }
251         return 0;
252 }
253
254 static inline struct mon_private *
255 mon_alloc_mem(void)
256 {
257         int i,j;
258         struct mon_private *monpriv;
259
260         monpriv = kzalloc(sizeof(struct mon_private), GFP_KERNEL);
261         if (!monpriv) {
262                 P_ERROR("no memory for monpriv\n");
263                 return NULL;
264         }
265         for (i = 0; i < MON_MSGLIM; i++) {
266                 monpriv->msg_array[i] = kzalloc(sizeof(struct mon_msg),
267                                                     GFP_KERNEL);
268                 if (!monpriv->msg_array[i]) {
269                         P_ERROR("open, no memory for msg_array\n");
270                         for (j = 0; j < i; j++)
271                                 kfree(monpriv->msg_array[j]);
272                         return NULL;
273                 }
274         }
275         return monpriv;
276 }
277
278 static inline void
279 mon_read_debug(struct mon_msg *monmsg, struct mon_private *monpriv)
280 {
281 #ifdef MON_DEBUG
282         u8 msg_type[2], mca_type;
283         unsigned long records_len;
284
285         records_len = mon_rec_end(monmsg) - mon_rec_start(monmsg) + 1;
286
287         memcpy(msg_type, &monmsg->local_eib.iptrgcls, 2);
288         EBCASC(msg_type, 2);
289         mca_type = mon_mca_type(monmsg, 0);
290         EBCASC(&mca_type, 1);
291
292         P_DEBUG("read, mon_read_index = %i, mon_write_index = %i\n",
293                 monpriv->read_index, monpriv->write_index);
294         P_DEBUG("read, pathid = 0x%04X, msgid = 0x%08X, trgcls = 0x%08X\n",
295                 monmsg->local_eib.ippathid, monmsg->local_eib.ipmsgid,
296                 monmsg->local_eib.iptrgcls);
297         P_DEBUG("read, msg_type = '%c%c', mca_type = '%c' / 0x%X / 0x%X\n",
298                 msg_type[0], msg_type[1], mca_type ? mca_type : 'X',
299                 mon_mca_type(monmsg, 1), mon_mca_type(monmsg, 2));
300         P_DEBUG("read, MCA: start = 0x%lX, end = 0x%lX\n",
301                 mon_mca_start(monmsg), mon_mca_end(monmsg));
302         P_DEBUG("read, REC: start = 0x%X, end = 0x%X, len = %lu\n\n",
303                 mon_rec_start(monmsg), mon_rec_end(monmsg), records_len);
304         if (mon_mca_size(monmsg) > 12)
305                 P_DEBUG("READ, MORE THAN ONE MCA\n\n");
306 #endif
307 }
308
309 static inline void
310 mon_next_mca(struct mon_msg *monmsg)
311 {
312         if (likely((mon_mca_size(monmsg) - monmsg->mca_offset) == 12))
313                 return;
314         P_DEBUG("READ, NEXT MCA\n\n");
315         monmsg->mca_offset += 12;
316         monmsg->pos = 0;
317 }
318
319 static inline struct mon_msg *
320 mon_next_message(struct mon_private *monpriv)
321 {
322         struct mon_msg *monmsg;
323
324         if (!atomic_read(&monpriv->read_ready))
325                 return NULL;
326         monmsg = monpriv->msg_array[monpriv->read_index];
327         if (unlikely(monmsg->replied_msglim)) {
328                 monmsg->replied_msglim = 0;
329                 monmsg->msglim_reached = 0;
330                 monmsg->pos = 0;
331                 monmsg->mca_offset = 0;
332                 P_WARNING("read, message limit reached\n");
333                 monpriv->read_index = (monpriv->read_index + 1) %
334                                       MON_MSGLIM;
335                 atomic_dec(&monpriv->read_ready);
336                 return ERR_PTR(-EOVERFLOW);
337         }
338         return monmsg;
339 }
340
341
342 /******************************************************************************
343  *                               IUCV handler                                 *
344  *****************************************************************************/
345 static void
346 mon_iucv_ConnectionComplete(iucv_ConnectionComplete *eib, void *pgm_data)
347 {
348         struct mon_private *monpriv = (struct mon_private *) pgm_data;
349
350         P_DEBUG("IUCV connection completed\n");
351         P_DEBUG("IUCV ACCEPT (from *MONITOR): Version = 0x%02X, Event = "
352                 "0x%02X, Sample = 0x%02X\n",
353                 eib->ipuser[0], eib->ipuser[1], eib->ipuser[2]);
354         atomic_set(&monpriv->iucv_connected, 1);
355         wake_up(&mon_conn_wait_queue);
356 }
357
358 static void
359 mon_iucv_ConnectionSevered(iucv_ConnectionSevered *eib, void *pgm_data)
360 {
361         struct mon_private *monpriv = (struct mon_private *) pgm_data;
362
363         P_ERROR("IUCV connection severed with rc = 0x%X\n",
364                 (u8) eib->ipuser[0]);
365         atomic_set(&monpriv->iucv_severed, 1);
366         wake_up(&mon_conn_wait_queue);
367         wake_up_interruptible(&mon_read_wait_queue);
368 }
369
370 static void
371 mon_iucv_MessagePending(iucv_MessagePending *eib, void *pgm_data)
372 {
373         struct mon_private *monpriv = (struct mon_private *) pgm_data;
374
375         P_DEBUG("IUCV message pending\n");
376         memcpy(&monpriv->msg_array[monpriv->write_index]->local_eib, eib,
377                sizeof(iucv_MessagePending));
378         if (atomic_inc_return(&monpriv->msglim_count) == MON_MSGLIM) {
379                 P_WARNING("IUCV message pending, message limit (%i) reached\n",
380                           MON_MSGLIM);
381                 monpriv->msg_array[monpriv->write_index]->msglim_reached = 1;
382         }
383         monpriv->write_index = (monpriv->write_index + 1) % MON_MSGLIM;
384         atomic_inc(&monpriv->read_ready);
385         wake_up_interruptible(&mon_read_wait_queue);
386 }
387
388 static iucv_interrupt_ops_t mon_iucvops = {
389         .ConnectionComplete = mon_iucv_ConnectionComplete,
390         .ConnectionSevered  = mon_iucv_ConnectionSevered,
391         .MessagePending     = mon_iucv_MessagePending,
392 };
393
394 /******************************************************************************
395  *                               file operations                              *
396  *****************************************************************************/
397 static int
398 mon_open(struct inode *inode, struct file *filp)
399 {
400         int rc, i;
401         struct mon_private *monpriv;
402
403         /*
404          * only one user allowed
405          */
406         if (test_and_set_bit(MON_IN_USE, &mon_in_use))
407                 return -EBUSY;
408
409         monpriv = mon_alloc_mem();
410         if (!monpriv)
411                 return -ENOMEM;
412
413         /*
414          * Register with IUCV and connect to *MONITOR service
415          */
416         monpriv->iucv_handle = iucv_register_program("my_monreader    ",
417                                                         MON_SERVICE,
418                                                         NULL,
419                                                         &mon_iucvops,
420                                                         monpriv);
421         if (!monpriv->iucv_handle) {
422                 P_ERROR("failed to register with iucv driver\n");
423                 rc = -EIO;
424                 goto out_error;
425         }
426         P_INFO("open, registered with IUCV\n");
427
428         rc = iucv_connect(&monpriv->pathid, MON_MSGLIM, user_data_connect,
429                           MON_SERVICE, iucv_host, IPRMDATA, NULL, NULL,
430                           monpriv->iucv_handle, NULL);
431         if (rc) {
432                 P_ERROR("iucv connection to *MONITOR failed with "
433                         "IPUSER SEVER code = %i\n", rc);
434                 rc = -EIO;
435                 goto out_unregister;
436         }
437         /*
438          * Wait for connection confirmation
439          */
440         wait_event(mon_conn_wait_queue,
441                    atomic_read(&monpriv->iucv_connected) ||
442                    atomic_read(&monpriv->iucv_severed));
443         if (atomic_read(&monpriv->iucv_severed)) {
444                 atomic_set(&monpriv->iucv_severed, 0);
445                 atomic_set(&monpriv->iucv_connected, 0);
446                 rc = -EIO;
447                 goto out_unregister;
448         }
449         P_INFO("open, established connection to *MONITOR service\n\n");
450         filp->private_data = monpriv;
451         return nonseekable_open(inode, filp);
452
453 out_unregister:
454         iucv_unregister_program(monpriv->iucv_handle);
455 out_error:
456         for (i = 0; i < MON_MSGLIM; i++)
457                 kfree(monpriv->msg_array[i]);
458         kfree(monpriv);
459         clear_bit(MON_IN_USE, &mon_in_use);
460         return rc;
461 }
462
463 static int
464 mon_close(struct inode *inode, struct file *filp)
465 {
466         int rc, i;
467         struct mon_private *monpriv = filp->private_data;
468
469         /*
470          * Close IUCV connection and unregister
471          */
472         rc = iucv_sever(monpriv->pathid, user_data_sever);
473         if (rc)
474                 P_ERROR("close, iucv_sever failed with rc = %i\n", rc);
475         else
476                 P_INFO("close, terminated connection to *MONITOR service\n");
477
478         rc = iucv_unregister_program(monpriv->iucv_handle);
479         if (rc)
480                 P_ERROR("close, iucv_unregister failed with rc = %i\n", rc);
481         else
482                 P_INFO("close, unregistered with IUCV\n");
483
484         atomic_set(&monpriv->iucv_severed, 0);
485         atomic_set(&monpriv->iucv_connected, 0);
486         atomic_set(&monpriv->read_ready, 0);
487         atomic_set(&monpriv->msglim_count, 0);
488         monpriv->write_index  = 0;
489         monpriv->read_index   = 0;
490
491         for (i = 0; i < MON_MSGLIM; i++)
492                 kfree(monpriv->msg_array[i]);
493         kfree(monpriv);
494         clear_bit(MON_IN_USE, &mon_in_use);
495         return 0;
496 }
497
498 static ssize_t
499 mon_read(struct file *filp, char __user *data, size_t count, loff_t *ppos)
500 {
501         struct mon_private *monpriv = filp->private_data;
502         struct mon_msg *monmsg;
503         int ret;
504         u32 mce_start;
505
506         monmsg = mon_next_message(monpriv);
507         if (IS_ERR(monmsg))
508                 return PTR_ERR(monmsg);
509
510         if (!monmsg) {
511                 if (filp->f_flags & O_NONBLOCK)
512                         return -EAGAIN;
513                 ret = wait_event_interruptible(mon_read_wait_queue,
514                                         atomic_read(&monpriv->read_ready) ||
515                                         atomic_read(&monpriv->iucv_severed));
516                 if (ret)
517                         return ret;
518                 if (unlikely(atomic_read(&monpriv->iucv_severed)))
519                         return -EIO;
520                 monmsg = monpriv->msg_array[monpriv->read_index];
521         }
522
523         if (!monmsg->pos) {
524                 monmsg->pos = mon_mca_start(monmsg) + monmsg->mca_offset;
525                 mon_read_debug(monmsg, monpriv);
526         }
527         if (mon_check_mca(monmsg))
528                 goto reply;
529
530         /* read monitor control element (12 bytes) first */
531         mce_start = mon_mca_start(monmsg) + monmsg->mca_offset;
532         if ((monmsg->pos >= mce_start) && (monmsg->pos < mce_start + 12)) {
533                 count = min(count, (size_t) mce_start + 12 - monmsg->pos);
534                 ret = copy_to_user(data, (void *) (unsigned long) monmsg->pos,
535                                    count);
536                 if (ret)
537                         return -EFAULT;
538                 monmsg->pos += count;
539                 if (monmsg->pos == mce_start + 12)
540                         monmsg->pos = mon_rec_start(monmsg);
541                 goto out_copy;
542         }
543
544         /* read records */
545         if (monmsg->pos <= mon_rec_end(monmsg)) {
546                 count = min(count, (size_t) mon_rec_end(monmsg) - monmsg->pos
547                                             + 1);
548                 ret = copy_to_user(data, (void *) (unsigned long) monmsg->pos,
549                                    count);
550                 if (ret)
551                         return -EFAULT;
552                 monmsg->pos += count;
553                 if (monmsg->pos > mon_rec_end(monmsg))
554                         mon_next_mca(monmsg);
555                 goto out_copy;
556         }
557 reply:
558         ret = mon_send_reply(monmsg, monpriv);
559         return ret;
560
561 out_copy:
562         *ppos += count;
563         return count;
564 }
565
566 static unsigned int
567 mon_poll(struct file *filp, struct poll_table_struct *p)
568 {
569         struct mon_private *monpriv = filp->private_data;
570
571         poll_wait(filp, &mon_read_wait_queue, p);
572         if (unlikely(atomic_read(&monpriv->iucv_severed)))
573                 return POLLERR;
574         if (atomic_read(&monpriv->read_ready))
575                 return POLLIN | POLLRDNORM;
576         return 0;
577 }
578
579 static struct file_operations mon_fops = {
580         .owner   = THIS_MODULE,
581         .open    = &mon_open,
582         .release = &mon_close,
583         .read    = &mon_read,
584         .poll    = &mon_poll,
585 };
586
587 static struct miscdevice mon_dev = {
588         .name       = "monreader",
589         .fops       = &mon_fops,
590         .minor      = MISC_DYNAMIC_MINOR,
591 };
592
593 /******************************************************************************
594  *                              module init/exit                              *
595  *****************************************************************************/
596 static int __init
597 mon_init(void)
598 {
599         int rc;
600
601         if (!MACHINE_IS_VM) {
602                 P_ERROR("not running under z/VM, driver not loaded\n");
603                 return -ENODEV;
604         }
605
606         rc = segment_type(mon_dcss_name);
607         if (rc < 0) {
608                 mon_segment_warn(rc, mon_dcss_name);
609                 return rc;
610         }
611         if (rc != SEG_TYPE_SC) {
612                 P_ERROR("segment %s has unsupported type, should be SC\n",
613                         mon_dcss_name);
614                 return -EINVAL;
615         }
616
617         rc = segment_load(mon_dcss_name, SEGMENT_SHARED,
618                           &mon_dcss_start, &mon_dcss_end);
619         if (rc < 0) {
620                 mon_segment_warn(rc, mon_dcss_name);
621                 return -EINVAL;
622         }
623         dcss_mkname(mon_dcss_name, &user_data_connect[8]);
624
625         rc = misc_register(&mon_dev);
626         if (rc < 0 ) {
627                 P_ERROR("misc_register failed, rc = %i\n", rc);
628                 goto out;
629         }
630         P_INFO("Loaded segment %s from %p to %p, size = %lu Byte\n",
631                 mon_dcss_name, (void *) mon_dcss_start, (void *) mon_dcss_end,
632                 mon_dcss_end - mon_dcss_start + 1);
633         return 0;
634
635 out:
636         segment_unload(mon_dcss_name);
637         return rc;
638 }
639
640 static void __exit
641 mon_exit(void)
642 {
643         segment_unload(mon_dcss_name);
644         WARN_ON(misc_deregister(&mon_dev) != 0);
645         return;
646 }
647
648
649 module_init(mon_init);
650 module_exit(mon_exit);
651
652 module_param_string(mondcss, mon_dcss_name, 9, 0444);
653 MODULE_PARM_DESC(mondcss, "Name of DCSS segment to be used for *MONITOR "
654                  "service, max. 8 chars. Default is MONDCSS");
655
656 MODULE_AUTHOR("Gerald Schaefer <geraldsc@de.ibm.com>");
657 MODULE_DESCRIPTION("Character device driver for reading z/VM "
658                    "monitor service records.");
659 MODULE_LICENSE("GPL");