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8
9#define KMSG_COMPONENT "monreader"
10#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
11
12#include <linux/module.h>
13#include <linux/moduleparam.h>
14#include <linux/init.h>
15#include <linux/errno.h>
16#include <linux/types.h>
17#include <linux/kernel.h>
18#include <linux/miscdevice.h>
19#include <linux/ctype.h>
20#include <linux/spinlock.h>
21#include <linux/interrupt.h>
22#include <linux/poll.h>
23#include <linux/device.h>
24#include <linux/slab.h>
25#include <net/iucv/iucv.h>
26#include <linux/uaccess.h>
27#include <asm/ebcdic.h>
28#include <asm/extmem.h>
29
30
31#define MON_COLLECT_SAMPLE 0x80
32#define MON_COLLECT_EVENT 0x40
33#define MON_SERVICE "*MONITOR"
34#define MON_IN_USE 0x01
35#define MON_MSGLIM 255
36
37static char mon_dcss_name[9] = "MONDCSS\0";
38
39struct mon_msg {
40 u32 pos;
41 u32 mca_offset;
42 struct iucv_message msg;
43 char msglim_reached;
44 char replied_msglim;
45};
46
47struct mon_private {
48 struct iucv_path *path;
49 struct mon_msg *msg_array[MON_MSGLIM];
50 unsigned int write_index;
51 unsigned int read_index;
52 atomic_t msglim_count;
53 atomic_t read_ready;
54 atomic_t iucv_connected;
55 atomic_t iucv_severed;
56};
57
58static unsigned long mon_in_use = 0;
59
60static unsigned long mon_dcss_start;
61static unsigned long mon_dcss_end;
62
63static DECLARE_WAIT_QUEUE_HEAD(mon_read_wait_queue);
64static DECLARE_WAIT_QUEUE_HEAD(mon_conn_wait_queue);
65
66static u8 user_data_connect[16] = {
67
68 0x01,
69
70 MON_COLLECT_SAMPLE | MON_COLLECT_EVENT,
71
72 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
73 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
74};
75
76static u8 user_data_sever[16] = {
77 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
78 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
79};
80
81static struct device *monreader_device;
82
83
84
85
86
87
88
89
90static void dcss_mkname(char *ascii_name, char *ebcdic_name)
91{
92 int i;
93
94 for (i = 0; i < 8; i++) {
95 if (ascii_name[i] == '\0')
96 break;
97 ebcdic_name[i] = toupper(ascii_name[i]);
98 }
99 for (; i < 8; i++)
100 ebcdic_name[i] = ' ';
101 ASCEBC(ebcdic_name, 8);
102}
103
104static inline unsigned long mon_mca_start(struct mon_msg *monmsg)
105{
106 return *(u32 *) &monmsg->msg.rmmsg;
107}
108
109static inline unsigned long mon_mca_end(struct mon_msg *monmsg)
110{
111 return *(u32 *) &monmsg->msg.rmmsg[4];
112}
113
114static inline u8 mon_mca_type(struct mon_msg *monmsg, u8 index)
115{
116 return *((u8 *) mon_mca_start(monmsg) + monmsg->mca_offset + index);
117}
118
119static inline u32 mon_mca_size(struct mon_msg *monmsg)
120{
121 return mon_mca_end(monmsg) - mon_mca_start(monmsg) + 1;
122}
123
124static inline u32 mon_rec_start(struct mon_msg *monmsg)
125{
126 return *((u32 *) (mon_mca_start(monmsg) + monmsg->mca_offset + 4));
127}
128
129static inline u32 mon_rec_end(struct mon_msg *monmsg)
130{
131 return *((u32 *) (mon_mca_start(monmsg) + monmsg->mca_offset + 8));
132}
133
134static int mon_check_mca(struct mon_msg *monmsg)
135{
136 if ((mon_rec_end(monmsg) <= mon_rec_start(monmsg)) ||
137 (mon_rec_start(monmsg) < mon_dcss_start) ||
138 (mon_rec_end(monmsg) > mon_dcss_end) ||
139 (mon_mca_type(monmsg, 0) == 0) ||
140 (mon_mca_size(monmsg) % 12 != 0) ||
141 (mon_mca_end(monmsg) <= mon_mca_start(monmsg)) ||
142 (mon_mca_end(monmsg) > mon_dcss_end) ||
143 (mon_mca_start(monmsg) < mon_dcss_start) ||
144 ((mon_mca_type(monmsg, 1) == 0) && (mon_mca_type(monmsg, 2) == 0)))
145 return -EINVAL;
146 return 0;
147}
148
149static int mon_send_reply(struct mon_msg *monmsg,
150 struct mon_private *monpriv)
151{
152 int rc;
153
154 rc = iucv_message_reply(monpriv->path, &monmsg->msg,
155 IUCV_IPRMDATA, NULL, 0);
156 atomic_dec(&monpriv->msglim_count);
157 if (likely(!monmsg->msglim_reached)) {
158 monmsg->pos = 0;
159 monmsg->mca_offset = 0;
160 monpriv->read_index = (monpriv->read_index + 1) %
161 MON_MSGLIM;
162 atomic_dec(&monpriv->read_ready);
163 } else
164 monmsg->replied_msglim = 1;
165 if (rc) {
166 pr_err("Reading monitor data failed with rc=%i\n", rc);
167 return -EIO;
168 }
169 return 0;
170}
171
172static void mon_free_mem(struct mon_private *monpriv)
173{
174 int i;
175
176 for (i = 0; i < MON_MSGLIM; i++)
177 kfree(monpriv->msg_array[i]);
178 kfree(monpriv);
179}
180
181static struct mon_private *mon_alloc_mem(void)
182{
183 int i;
184 struct mon_private *monpriv;
185
186 monpriv = kzalloc(sizeof(struct mon_private), GFP_KERNEL);
187 if (!monpriv)
188 return NULL;
189 for (i = 0; i < MON_MSGLIM; i++) {
190 monpriv->msg_array[i] = kzalloc(sizeof(struct mon_msg),
191 GFP_KERNEL);
192 if (!monpriv->msg_array[i]) {
193 mon_free_mem(monpriv);
194 return NULL;
195 }
196 }
197 return monpriv;
198}
199
200static inline void mon_next_mca(struct mon_msg *monmsg)
201{
202 if (likely((mon_mca_size(monmsg) - monmsg->mca_offset) == 12))
203 return;
204 monmsg->mca_offset += 12;
205 monmsg->pos = 0;
206}
207
208static struct mon_msg *mon_next_message(struct mon_private *monpriv)
209{
210 struct mon_msg *monmsg;
211
212 if (!atomic_read(&monpriv->read_ready))
213 return NULL;
214 monmsg = monpriv->msg_array[monpriv->read_index];
215 if (unlikely(monmsg->replied_msglim)) {
216 monmsg->replied_msglim = 0;
217 monmsg->msglim_reached = 0;
218 monmsg->pos = 0;
219 monmsg->mca_offset = 0;
220 monpriv->read_index = (monpriv->read_index + 1) %
221 MON_MSGLIM;
222 atomic_dec(&monpriv->read_ready);
223 return ERR_PTR(-EOVERFLOW);
224 }
225 return monmsg;
226}
227
228
229
230
231
232static void mon_iucv_path_complete(struct iucv_path *path, u8 *ipuser)
233{
234 struct mon_private *monpriv = path->private;
235
236 atomic_set(&monpriv->iucv_connected, 1);
237 wake_up(&mon_conn_wait_queue);
238}
239
240static void mon_iucv_path_severed(struct iucv_path *path, u8 *ipuser)
241{
242 struct mon_private *monpriv = path->private;
243
244 pr_err("z/VM *MONITOR system service disconnected with rc=%i\n",
245 ipuser[0]);
246 iucv_path_sever(path, NULL);
247 atomic_set(&monpriv->iucv_severed, 1);
248 wake_up(&mon_conn_wait_queue);
249 wake_up_interruptible(&mon_read_wait_queue);
250}
251
252static void mon_iucv_message_pending(struct iucv_path *path,
253 struct iucv_message *msg)
254{
255 struct mon_private *monpriv = path->private;
256
257 memcpy(&monpriv->msg_array[monpriv->write_index]->msg,
258 msg, sizeof(*msg));
259 if (atomic_inc_return(&monpriv->msglim_count) == MON_MSGLIM) {
260 pr_warn("The read queue for monitor data is full\n");
261 monpriv->msg_array[monpriv->write_index]->msglim_reached = 1;
262 }
263 monpriv->write_index = (monpriv->write_index + 1) % MON_MSGLIM;
264 atomic_inc(&monpriv->read_ready);
265 wake_up_interruptible(&mon_read_wait_queue);
266}
267
268static struct iucv_handler monreader_iucv_handler = {
269 .path_complete = mon_iucv_path_complete,
270 .path_severed = mon_iucv_path_severed,
271 .message_pending = mon_iucv_message_pending,
272};
273
274
275
276
277static int mon_open(struct inode *inode, struct file *filp)
278{
279 struct mon_private *monpriv;
280 int rc;
281
282
283
284
285 rc = -EBUSY;
286 if (test_and_set_bit(MON_IN_USE, &mon_in_use))
287 goto out;
288
289 rc = -ENOMEM;
290 monpriv = mon_alloc_mem();
291 if (!monpriv)
292 goto out_use;
293
294
295
296
297 monpriv->path = iucv_path_alloc(MON_MSGLIM, IUCV_IPRMDATA, GFP_KERNEL);
298 if (!monpriv->path)
299 goto out_priv;
300 rc = iucv_path_connect(monpriv->path, &monreader_iucv_handler,
301 MON_SERVICE, NULL, user_data_connect, monpriv);
302 if (rc) {
303 pr_err("Connecting to the z/VM *MONITOR system service "
304 "failed with rc=%i\n", rc);
305 rc = -EIO;
306 goto out_path;
307 }
308
309
310
311 wait_event(mon_conn_wait_queue,
312 atomic_read(&monpriv->iucv_connected) ||
313 atomic_read(&monpriv->iucv_severed));
314 if (atomic_read(&monpriv->iucv_severed)) {
315 atomic_set(&monpriv->iucv_severed, 0);
316 atomic_set(&monpriv->iucv_connected, 0);
317 rc = -EIO;
318 goto out_path;
319 }
320 filp->private_data = monpriv;
321 dev_set_drvdata(monreader_device, monpriv);
322 return nonseekable_open(inode, filp);
323
324out_path:
325 iucv_path_free(monpriv->path);
326out_priv:
327 mon_free_mem(monpriv);
328out_use:
329 clear_bit(MON_IN_USE, &mon_in_use);
330out:
331 return rc;
332}
333
334static int mon_close(struct inode *inode, struct file *filp)
335{
336 int rc, i;
337 struct mon_private *monpriv = filp->private_data;
338
339
340
341
342 if (monpriv->path) {
343 rc = iucv_path_sever(monpriv->path, user_data_sever);
344 if (rc)
345 pr_warn("Disconnecting the z/VM *MONITOR system service failed with rc=%i\n",
346 rc);
347 iucv_path_free(monpriv->path);
348 }
349
350 atomic_set(&monpriv->iucv_severed, 0);
351 atomic_set(&monpriv->iucv_connected, 0);
352 atomic_set(&monpriv->read_ready, 0);
353 atomic_set(&monpriv->msglim_count, 0);
354 monpriv->write_index = 0;
355 monpriv->read_index = 0;
356 dev_set_drvdata(monreader_device, NULL);
357
358 for (i = 0; i < MON_MSGLIM; i++)
359 kfree(monpriv->msg_array[i]);
360 kfree(monpriv);
361 clear_bit(MON_IN_USE, &mon_in_use);
362 return 0;
363}
364
365static ssize_t mon_read(struct file *filp, char __user *data,
366 size_t count, loff_t *ppos)
367{
368 struct mon_private *monpriv = filp->private_data;
369 struct mon_msg *monmsg;
370 int ret;
371 u32 mce_start;
372
373 monmsg = mon_next_message(monpriv);
374 if (IS_ERR(monmsg))
375 return PTR_ERR(monmsg);
376
377 if (!monmsg) {
378 if (filp->f_flags & O_NONBLOCK)
379 return -EAGAIN;
380 ret = wait_event_interruptible(mon_read_wait_queue,
381 atomic_read(&monpriv->read_ready) ||
382 atomic_read(&monpriv->iucv_severed));
383 if (ret)
384 return ret;
385 if (unlikely(atomic_read(&monpriv->iucv_severed)))
386 return -EIO;
387 monmsg = monpriv->msg_array[monpriv->read_index];
388 }
389
390 if (!monmsg->pos)
391 monmsg->pos = mon_mca_start(monmsg) + monmsg->mca_offset;
392 if (mon_check_mca(monmsg))
393 goto reply;
394
395
396 mce_start = mon_mca_start(monmsg) + monmsg->mca_offset;
397 if ((monmsg->pos >= mce_start) && (monmsg->pos < mce_start + 12)) {
398 count = min(count, (size_t) mce_start + 12 - monmsg->pos);
399 ret = copy_to_user(data, (void *) (unsigned long) monmsg->pos,
400 count);
401 if (ret)
402 return -EFAULT;
403 monmsg->pos += count;
404 if (monmsg->pos == mce_start + 12)
405 monmsg->pos = mon_rec_start(monmsg);
406 goto out_copy;
407 }
408
409
410 if (monmsg->pos <= mon_rec_end(monmsg)) {
411 count = min(count, (size_t) mon_rec_end(monmsg) - monmsg->pos
412 + 1);
413 ret = copy_to_user(data, (void *) (unsigned long) monmsg->pos,
414 count);
415 if (ret)
416 return -EFAULT;
417 monmsg->pos += count;
418 if (monmsg->pos > mon_rec_end(monmsg))
419 mon_next_mca(monmsg);
420 goto out_copy;
421 }
422reply:
423 ret = mon_send_reply(monmsg, monpriv);
424 return ret;
425
426out_copy:
427 *ppos += count;
428 return count;
429}
430
431static unsigned int mon_poll(struct file *filp, struct poll_table_struct *p)
432{
433 struct mon_private *monpriv = filp->private_data;
434
435 poll_wait(filp, &mon_read_wait_queue, p);
436 if (unlikely(atomic_read(&monpriv->iucv_severed)))
437 return POLLERR;
438 if (atomic_read(&monpriv->read_ready))
439 return POLLIN | POLLRDNORM;
440 return 0;
441}
442
443static const struct file_operations mon_fops = {
444 .owner = THIS_MODULE,
445 .open = &mon_open,
446 .release = &mon_close,
447 .read = &mon_read,
448 .poll = &mon_poll,
449 .llseek = noop_llseek,
450};
451
452static struct miscdevice mon_dev = {
453 .name = "monreader",
454 .fops = &mon_fops,
455 .minor = MISC_DYNAMIC_MINOR,
456};
457
458
459
460
461
462static int monreader_freeze(struct device *dev)
463{
464 struct mon_private *monpriv = dev_get_drvdata(dev);
465 int rc;
466
467 if (!monpriv)
468 return 0;
469 if (monpriv->path) {
470 rc = iucv_path_sever(monpriv->path, user_data_sever);
471 if (rc)
472 pr_warn("Disconnecting the z/VM *MONITOR system service failed with rc=%i\n",
473 rc);
474 iucv_path_free(monpriv->path);
475 }
476 atomic_set(&monpriv->iucv_severed, 0);
477 atomic_set(&monpriv->iucv_connected, 0);
478 atomic_set(&monpriv->read_ready, 0);
479 atomic_set(&monpriv->msglim_count, 0);
480 monpriv->write_index = 0;
481 monpriv->read_index = 0;
482 monpriv->path = NULL;
483 return 0;
484}
485
486static int monreader_thaw(struct device *dev)
487{
488 struct mon_private *monpriv = dev_get_drvdata(dev);
489 int rc;
490
491 if (!monpriv)
492 return 0;
493 rc = -ENOMEM;
494 monpriv->path = iucv_path_alloc(MON_MSGLIM, IUCV_IPRMDATA, GFP_KERNEL);
495 if (!monpriv->path)
496 goto out;
497 rc = iucv_path_connect(monpriv->path, &monreader_iucv_handler,
498 MON_SERVICE, NULL, user_data_connect, monpriv);
499 if (rc) {
500 pr_err("Connecting to the z/VM *MONITOR system service "
501 "failed with rc=%i\n", rc);
502 goto out_path;
503 }
504 wait_event(mon_conn_wait_queue,
505 atomic_read(&monpriv->iucv_connected) ||
506 atomic_read(&monpriv->iucv_severed));
507 if (atomic_read(&monpriv->iucv_severed))
508 goto out_path;
509 return 0;
510out_path:
511 rc = -EIO;
512 iucv_path_free(monpriv->path);
513 monpriv->path = NULL;
514out:
515 atomic_set(&monpriv->iucv_severed, 1);
516 return rc;
517}
518
519static int monreader_restore(struct device *dev)
520{
521 int rc;
522
523 segment_unload(mon_dcss_name);
524 rc = segment_load(mon_dcss_name, SEGMENT_SHARED,
525 &mon_dcss_start, &mon_dcss_end);
526 if (rc < 0) {
527 segment_warning(rc, mon_dcss_name);
528 panic("fatal monreader resume error: no monitor dcss\n");
529 }
530 return monreader_thaw(dev);
531}
532
533static const struct dev_pm_ops monreader_pm_ops = {
534 .freeze = monreader_freeze,
535 .thaw = monreader_thaw,
536 .restore = monreader_restore,
537};
538
539static struct device_driver monreader_driver = {
540 .name = "monreader",
541 .bus = &iucv_bus,
542 .pm = &monreader_pm_ops,
543};
544
545
546
547
548
549static int __init mon_init(void)
550{
551 int rc;
552
553 if (!MACHINE_IS_VM) {
554 pr_err("The z/VM *MONITOR record device driver cannot be "
555 "loaded without z/VM\n");
556 return -ENODEV;
557 }
558
559
560
561
562 rc = iucv_register(&monreader_iucv_handler, 1);
563 if (rc) {
564 pr_err("The z/VM *MONITOR record device driver failed to "
565 "register with IUCV\n");
566 return rc;
567 }
568
569 rc = driver_register(&monreader_driver);
570 if (rc)
571 goto out_iucv;
572 monreader_device = kzalloc(sizeof(struct device), GFP_KERNEL);
573 if (!monreader_device) {
574 rc = -ENOMEM;
575 goto out_driver;
576 }
577
578 dev_set_name(monreader_device, "monreader-dev");
579 monreader_device->bus = &iucv_bus;
580 monreader_device->parent = iucv_root;
581 monreader_device->driver = &monreader_driver;
582 monreader_device->release = (void (*)(struct device *))kfree;
583 rc = device_register(monreader_device);
584 if (rc) {
585 put_device(monreader_device);
586 goto out_driver;
587 }
588
589 rc = segment_type(mon_dcss_name);
590 if (rc < 0) {
591 segment_warning(rc, mon_dcss_name);
592 goto out_device;
593 }
594 if (rc != SEG_TYPE_SC) {
595 pr_err("The specified *MONITOR DCSS %s does not have the "
596 "required type SC\n", mon_dcss_name);
597 rc = -EINVAL;
598 goto out_device;
599 }
600
601 rc = segment_load(mon_dcss_name, SEGMENT_SHARED,
602 &mon_dcss_start, &mon_dcss_end);
603 if (rc < 0) {
604 segment_warning(rc, mon_dcss_name);
605 rc = -EINVAL;
606 goto out_device;
607 }
608 dcss_mkname(mon_dcss_name, &user_data_connect[8]);
609
610
611
612
613
614 rc = misc_register(&mon_dev);
615 if (rc < 0 )
616 goto out;
617 return 0;
618
619out:
620 segment_unload(mon_dcss_name);
621out_device:
622 device_unregister(monreader_device);
623out_driver:
624 driver_unregister(&monreader_driver);
625out_iucv:
626 iucv_unregister(&monreader_iucv_handler, 1);
627 return rc;
628}
629
630static void __exit mon_exit(void)
631{
632 segment_unload(mon_dcss_name);
633 misc_deregister(&mon_dev);
634 device_unregister(monreader_device);
635 driver_unregister(&monreader_driver);
636 iucv_unregister(&monreader_iucv_handler, 1);
637 return;
638}
639
640
641module_init(mon_init);
642module_exit(mon_exit);
643
644module_param_string(mondcss, mon_dcss_name, 9, 0444);
645MODULE_PARM_DESC(mondcss, "Name of DCSS segment to be used for *MONITOR "
646 "service, max. 8 chars. Default is MONDCSS");
647
648MODULE_AUTHOR("Gerald Schaefer <geraldsc@de.ibm.com>");
649MODULE_DESCRIPTION("Character device driver for reading z/VM "
650 "monitor service records.");
651MODULE_LICENSE("GPL");
652
