1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * character device driver for reading z/VM system service records |
4 | * |
5 | * |
6 | * Copyright IBM Corp. 2004, 2009 |
7 | * character device driver for reading z/VM system service records, |
8 | * Version 1.0 |
9 | * Author(s): Xenia Tkatschow <xenia@us.ibm.com> |
10 | * Stefan Weinhuber <wein@de.ibm.com> |
11 | * |
12 | */ |
13 | |
14 | #define KMSG_COMPONENT "vmlogrdr" |
15 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt |
16 | |
17 | #include <linux/module.h> |
18 | #include <linux/init.h> |
19 | #include <linux/slab.h> |
20 | #include <linux/errno.h> |
21 | #include <linux/types.h> |
22 | #include <linux/interrupt.h> |
23 | #include <linux/spinlock.h> |
24 | #include <linux/atomic.h> |
25 | #include <linux/uaccess.h> |
26 | #include <asm/cpcmd.h> |
27 | #include <asm/debug.h> |
28 | #include <asm/ebcdic.h> |
29 | #include <net/iucv/iucv.h> |
30 | #include <linux/kmod.h> |
31 | #include <linux/cdev.h> |
32 | #include <linux/device.h> |
33 | #include <linux/string.h> |
34 | |
35 | MODULE_AUTHOR |
36 | ("(C) 2004 IBM Corporation by Xenia Tkatschow (xenia@us.ibm.com)\n" |
37 | " Stefan Weinhuber (wein@de.ibm.com)" ); |
38 | MODULE_DESCRIPTION ("Character device driver for reading z/VM " |
39 | "system service records." ); |
40 | MODULE_LICENSE("GPL" ); |
41 | |
42 | |
43 | /* |
44 | * The size of the buffer for iucv data transfer is one page, |
45 | * but in addition to the data we read from iucv we also |
46 | * place an integer and some characters into that buffer, |
47 | * so the maximum size for record data is a little less then |
48 | * one page. |
49 | */ |
50 | #define NET_BUFFER_SIZE (PAGE_SIZE - sizeof(int) - sizeof(FENCE)) |
51 | |
52 | /* |
53 | * The elements that are concurrently accessed by bottom halves are |
54 | * connection_established, iucv_path_severed, local_interrupt_buffer |
55 | * and receive_ready. The first three can be protected by |
56 | * priv_lock. receive_ready is atomic, so it can be incremented and |
57 | * decremented without holding a lock. |
58 | * The variable dev_in_use needs to be protected by the lock, since |
59 | * it's a flag used by open to make sure that the device is opened only |
60 | * by one user at the same time. |
61 | */ |
62 | struct vmlogrdr_priv_t { |
63 | char system_service[8]; |
64 | char internal_name[8]; |
65 | char recording_name[8]; |
66 | struct iucv_path *path; |
67 | int connection_established; |
68 | int iucv_path_severed; |
69 | struct iucv_message local_interrupt_buffer; |
70 | atomic_t receive_ready; |
71 | int minor_num; |
72 | char * buffer; |
73 | char * current_position; |
74 | int remaining; |
75 | ulong residual_length; |
76 | int buffer_free; |
77 | int dev_in_use; /* 1: already opened, 0: not opened*/ |
78 | spinlock_t priv_lock; |
79 | struct device *device; |
80 | struct device *class_device; |
81 | int autorecording; |
82 | int autopurge; |
83 | }; |
84 | |
85 | |
86 | /* |
87 | * File operation structure for vmlogrdr devices |
88 | */ |
89 | static int vmlogrdr_open(struct inode *, struct file *); |
90 | static int vmlogrdr_release(struct inode *, struct file *); |
91 | static ssize_t vmlogrdr_read (struct file *filp, char __user *data, |
92 | size_t count, loff_t * ppos); |
93 | |
94 | static const struct file_operations vmlogrdr_fops = { |
95 | .owner = THIS_MODULE, |
96 | .open = vmlogrdr_open, |
97 | .release = vmlogrdr_release, |
98 | .read = vmlogrdr_read, |
99 | .llseek = no_llseek, |
100 | }; |
101 | |
102 | |
103 | static void vmlogrdr_iucv_path_complete(struct iucv_path *, u8 *ipuser); |
104 | static void vmlogrdr_iucv_path_severed(struct iucv_path *, u8 *ipuser); |
105 | static void vmlogrdr_iucv_message_pending(struct iucv_path *, |
106 | struct iucv_message *); |
107 | |
108 | |
109 | static struct iucv_handler vmlogrdr_iucv_handler = { |
110 | .path_complete = vmlogrdr_iucv_path_complete, |
111 | .path_severed = vmlogrdr_iucv_path_severed, |
112 | .message_pending = vmlogrdr_iucv_message_pending, |
113 | }; |
114 | |
115 | |
116 | static DECLARE_WAIT_QUEUE_HEAD(conn_wait_queue); |
117 | static DECLARE_WAIT_QUEUE_HEAD(read_wait_queue); |
118 | |
119 | /* |
120 | * pointer to system service private structure |
121 | * minor number 0 --> logrec |
122 | * minor number 1 --> account |
123 | * minor number 2 --> symptom |
124 | */ |
125 | |
126 | static struct vmlogrdr_priv_t sys_ser[] = { |
127 | { .system_service = "*LOGREC " , |
128 | .internal_name = "logrec" , |
129 | .recording_name = "EREP" , |
130 | .minor_num = 0, |
131 | .buffer_free = 1, |
132 | .priv_lock = __SPIN_LOCK_UNLOCKED(sys_ser[0].priv_lock), |
133 | .autorecording = 1, |
134 | .autopurge = 1, |
135 | }, |
136 | { .system_service = "*ACCOUNT" , |
137 | .internal_name = "account" , |
138 | .recording_name = "ACCOUNT" , |
139 | .minor_num = 1, |
140 | .buffer_free = 1, |
141 | .priv_lock = __SPIN_LOCK_UNLOCKED(sys_ser[1].priv_lock), |
142 | .autorecording = 1, |
143 | .autopurge = 1, |
144 | }, |
145 | { .system_service = "*SYMPTOM" , |
146 | .internal_name = "symptom" , |
147 | .recording_name = "SYMPTOM" , |
148 | .minor_num = 2, |
149 | .buffer_free = 1, |
150 | .priv_lock = __SPIN_LOCK_UNLOCKED(sys_ser[2].priv_lock), |
151 | .autorecording = 1, |
152 | .autopurge = 1, |
153 | } |
154 | }; |
155 | |
156 | #define MAXMINOR ARRAY_SIZE(sys_ser) |
157 | |
158 | static char FENCE[] = {"EOR" }; |
159 | static int vmlogrdr_major = 0; |
160 | static struct cdev *vmlogrdr_cdev = NULL; |
161 | static int recording_class_AB; |
162 | |
163 | |
164 | static void vmlogrdr_iucv_path_complete(struct iucv_path *path, u8 *ipuser) |
165 | { |
166 | struct vmlogrdr_priv_t * logptr = path->private; |
167 | |
168 | spin_lock(lock: &logptr->priv_lock); |
169 | logptr->connection_established = 1; |
170 | spin_unlock(lock: &logptr->priv_lock); |
171 | wake_up(&conn_wait_queue); |
172 | } |
173 | |
174 | |
175 | static void vmlogrdr_iucv_path_severed(struct iucv_path *path, u8 *ipuser) |
176 | { |
177 | struct vmlogrdr_priv_t * logptr = path->private; |
178 | u8 reason = (u8) ipuser[8]; |
179 | |
180 | pr_err("vmlogrdr: connection severed with reason %i\n" , reason); |
181 | |
182 | iucv_path_sever(path, NULL); |
183 | kfree(objp: path); |
184 | logptr->path = NULL; |
185 | |
186 | spin_lock(lock: &logptr->priv_lock); |
187 | logptr->connection_established = 0; |
188 | logptr->iucv_path_severed = 1; |
189 | spin_unlock(lock: &logptr->priv_lock); |
190 | |
191 | wake_up(&conn_wait_queue); |
192 | /* just in case we're sleeping waiting for a record */ |
193 | wake_up_interruptible(&read_wait_queue); |
194 | } |
195 | |
196 | |
197 | static void vmlogrdr_iucv_message_pending(struct iucv_path *path, |
198 | struct iucv_message *msg) |
199 | { |
200 | struct vmlogrdr_priv_t * logptr = path->private; |
201 | |
202 | /* |
203 | * This function is the bottom half so it should be quick. |
204 | * Copy the external interrupt data into our local eib and increment |
205 | * the usage count |
206 | */ |
207 | spin_lock(lock: &logptr->priv_lock); |
208 | memcpy(&logptr->local_interrupt_buffer, msg, sizeof(*msg)); |
209 | atomic_inc(v: &logptr->receive_ready); |
210 | spin_unlock(lock: &logptr->priv_lock); |
211 | wake_up_interruptible(&read_wait_queue); |
212 | } |
213 | |
214 | |
215 | static int vmlogrdr_get_recording_class_AB(void) |
216 | { |
217 | static const char cp_command[] = "QUERY COMMAND RECORDING " ; |
218 | char cp_response[80]; |
219 | char *tail; |
220 | int len,i; |
221 | |
222 | cpcmd(cp_command, cp_response, sizeof(cp_response), NULL); |
223 | len = strnlen(p: cp_response,maxlen: sizeof(cp_response)); |
224 | // now the parsing |
225 | tail=strnchr(cp_response,len,'='); |
226 | if (!tail) |
227 | return 0; |
228 | tail++; |
229 | if (!strncmp("ANY" ,tail,3)) |
230 | return 1; |
231 | if (!strncmp("NONE" ,tail,4)) |
232 | return 0; |
233 | /* |
234 | * expect comma separated list of classes here, if one of them |
235 | * is A or B return 1 otherwise 0 |
236 | */ |
237 | for (i=tail-cp_response; i<len; i++) |
238 | if ( cp_response[i]=='A' || cp_response[i]=='B' ) |
239 | return 1; |
240 | return 0; |
241 | } |
242 | |
243 | |
244 | static int vmlogrdr_recording(struct vmlogrdr_priv_t * logptr, |
245 | int action, int purge) |
246 | { |
247 | |
248 | char cp_command[80]; |
249 | char cp_response[160]; |
250 | char *onoff, *qid_string; |
251 | int rc; |
252 | |
253 | onoff = ((action == 1) ? "ON" : "OFF" ); |
254 | qid_string = ((recording_class_AB == 1) ? " QID * " : "" ); |
255 | |
256 | /* |
257 | * The recording commands needs to be called with option QID |
258 | * for guests that have previlege classes A or B. |
259 | * Purging has to be done as separate step, because recording |
260 | * can't be switched on as long as records are on the queue. |
261 | * Doing both at the same time doesn't work. |
262 | */ |
263 | if (purge && (action == 1)) { |
264 | memset(cp_command, 0x00, sizeof(cp_command)); |
265 | memset(cp_response, 0x00, sizeof(cp_response)); |
266 | snprintf(buf: cp_command, size: sizeof(cp_command), |
267 | fmt: "RECORDING %s PURGE %s" , |
268 | logptr->recording_name, |
269 | qid_string); |
270 | cpcmd(cp_command, cp_response, sizeof(cp_response), NULL); |
271 | } |
272 | |
273 | memset(cp_command, 0x00, sizeof(cp_command)); |
274 | memset(cp_response, 0x00, sizeof(cp_response)); |
275 | snprintf(buf: cp_command, size: sizeof(cp_command), fmt: "RECORDING %s %s %s" , |
276 | logptr->recording_name, |
277 | onoff, |
278 | qid_string); |
279 | cpcmd(cp_command, cp_response, sizeof(cp_response), NULL); |
280 | /* The recording command will usually answer with 'Command complete' |
281 | * on success, but when the specific service was never connected |
282 | * before then there might be an additional informational message |
283 | * 'HCPCRC8072I Recording entry not found' before the |
284 | * 'Command complete'. So I use strstr rather then the strncmp. |
285 | */ |
286 | if (strstr(cp_response,"Command complete" )) |
287 | rc = 0; |
288 | else |
289 | rc = -EIO; |
290 | /* |
291 | * If we turn recording off, we have to purge any remaining records |
292 | * afterwards, as a large number of queued records may impact z/VM |
293 | * performance. |
294 | */ |
295 | if (purge && (action == 0)) { |
296 | memset(cp_command, 0x00, sizeof(cp_command)); |
297 | memset(cp_response, 0x00, sizeof(cp_response)); |
298 | snprintf(buf: cp_command, size: sizeof(cp_command), |
299 | fmt: "RECORDING %s PURGE %s" , |
300 | logptr->recording_name, |
301 | qid_string); |
302 | cpcmd(cp_command, cp_response, sizeof(cp_response), NULL); |
303 | } |
304 | |
305 | return rc; |
306 | } |
307 | |
308 | |
309 | static int vmlogrdr_open (struct inode *inode, struct file *filp) |
310 | { |
311 | int dev_num = 0; |
312 | struct vmlogrdr_priv_t * logptr = NULL; |
313 | int connect_rc = 0; |
314 | int ret; |
315 | |
316 | dev_num = iminor(inode); |
317 | if (dev_num >= MAXMINOR) |
318 | return -ENODEV; |
319 | logptr = &sys_ser[dev_num]; |
320 | |
321 | /* |
322 | * only allow for blocking reads to be open |
323 | */ |
324 | if (filp->f_flags & O_NONBLOCK) |
325 | return -EOPNOTSUPP; |
326 | |
327 | /* Besure this device hasn't already been opened */ |
328 | spin_lock_bh(lock: &logptr->priv_lock); |
329 | if (logptr->dev_in_use) { |
330 | spin_unlock_bh(lock: &logptr->priv_lock); |
331 | return -EBUSY; |
332 | } |
333 | logptr->dev_in_use = 1; |
334 | logptr->connection_established = 0; |
335 | logptr->iucv_path_severed = 0; |
336 | atomic_set(v: &logptr->receive_ready, i: 0); |
337 | logptr->buffer_free = 1; |
338 | spin_unlock_bh(lock: &logptr->priv_lock); |
339 | |
340 | /* set the file options */ |
341 | filp->private_data = logptr; |
342 | |
343 | /* start recording for this service*/ |
344 | if (logptr->autorecording) { |
345 | ret = vmlogrdr_recording(logptr,action: 1,purge: logptr->autopurge); |
346 | if (ret) |
347 | pr_warn("vmlogrdr: failed to start recording automatically\n" ); |
348 | } |
349 | |
350 | /* create connection to the system service */ |
351 | logptr->path = iucv_path_alloc(msglim: 10, flags: 0, GFP_KERNEL); |
352 | if (!logptr->path) |
353 | goto out_dev; |
354 | connect_rc = iucv_path_connect(path: logptr->path, handler: &vmlogrdr_iucv_handler, |
355 | userid: logptr->system_service, NULL, NULL, |
356 | private: logptr); |
357 | if (connect_rc) { |
358 | pr_err("vmlogrdr: iucv connection to %s " |
359 | "failed with rc %i \n" , |
360 | logptr->system_service, connect_rc); |
361 | goto out_path; |
362 | } |
363 | |
364 | /* We've issued the connect and now we must wait for a |
365 | * ConnectionComplete or ConnectinSevered Interrupt |
366 | * before we can continue to process. |
367 | */ |
368 | wait_event(conn_wait_queue, (logptr->connection_established) |
369 | || (logptr->iucv_path_severed)); |
370 | if (logptr->iucv_path_severed) |
371 | goto out_record; |
372 | nonseekable_open(inode, filp); |
373 | return 0; |
374 | |
375 | out_record: |
376 | if (logptr->autorecording) |
377 | vmlogrdr_recording(logptr,action: 0,purge: logptr->autopurge); |
378 | out_path: |
379 | kfree(objp: logptr->path); /* kfree(NULL) is ok. */ |
380 | logptr->path = NULL; |
381 | out_dev: |
382 | logptr->dev_in_use = 0; |
383 | return -EIO; |
384 | } |
385 | |
386 | |
387 | static int vmlogrdr_release (struct inode *inode, struct file *filp) |
388 | { |
389 | int ret; |
390 | |
391 | struct vmlogrdr_priv_t * logptr = filp->private_data; |
392 | |
393 | iucv_path_sever(path: logptr->path, NULL); |
394 | kfree(objp: logptr->path); |
395 | logptr->path = NULL; |
396 | if (logptr->autorecording) { |
397 | ret = vmlogrdr_recording(logptr,action: 0,purge: logptr->autopurge); |
398 | if (ret) |
399 | pr_warn("vmlogrdr: failed to stop recording automatically\n" ); |
400 | } |
401 | logptr->dev_in_use = 0; |
402 | |
403 | return 0; |
404 | } |
405 | |
406 | |
407 | static int vmlogrdr_receive_data(struct vmlogrdr_priv_t *priv) |
408 | { |
409 | int rc, *temp; |
410 | /* we need to keep track of two data sizes here: |
411 | * The number of bytes we need to receive from iucv and |
412 | * the total number of bytes we actually write into the buffer. |
413 | */ |
414 | int user_data_count, iucv_data_count; |
415 | char * buffer; |
416 | |
417 | if (atomic_read(v: &priv->receive_ready)) { |
418 | spin_lock_bh(lock: &priv->priv_lock); |
419 | if (priv->residual_length){ |
420 | /* receive second half of a record */ |
421 | iucv_data_count = priv->residual_length; |
422 | user_data_count = 0; |
423 | buffer = priv->buffer; |
424 | } else { |
425 | /* receive a new record: |
426 | * We need to return the total length of the record |
427 | * + size of FENCE in the first 4 bytes of the buffer. |
428 | */ |
429 | iucv_data_count = priv->local_interrupt_buffer.length; |
430 | user_data_count = sizeof(int); |
431 | temp = (int*)priv->buffer; |
432 | *temp= iucv_data_count + sizeof(FENCE); |
433 | buffer = priv->buffer + sizeof(int); |
434 | } |
435 | /* |
436 | * If the record is bigger than our buffer, we receive only |
437 | * a part of it. We can get the rest later. |
438 | */ |
439 | if (iucv_data_count > NET_BUFFER_SIZE) |
440 | iucv_data_count = NET_BUFFER_SIZE; |
441 | rc = iucv_message_receive(path: priv->path, |
442 | msg: &priv->local_interrupt_buffer, |
443 | flags: 0, buffer, size: iucv_data_count, |
444 | residual: &priv->residual_length); |
445 | spin_unlock_bh(lock: &priv->priv_lock); |
446 | /* An rc of 5 indicates that the record was bigger than |
447 | * the buffer, which is OK for us. A 9 indicates that the |
448 | * record was purged befor we could receive it. |
449 | */ |
450 | if (rc == 5) |
451 | rc = 0; |
452 | if (rc == 9) |
453 | atomic_set(v: &priv->receive_ready, i: 0); |
454 | } else { |
455 | rc = 1; |
456 | } |
457 | if (!rc) { |
458 | priv->buffer_free = 0; |
459 | user_data_count += iucv_data_count; |
460 | priv->current_position = priv->buffer; |
461 | if (priv->residual_length == 0){ |
462 | /* the whole record has been captured, |
463 | * now add the fence */ |
464 | atomic_dec(v: &priv->receive_ready); |
465 | buffer = priv->buffer + user_data_count; |
466 | memcpy(buffer, FENCE, sizeof(FENCE)); |
467 | user_data_count += sizeof(FENCE); |
468 | } |
469 | priv->remaining = user_data_count; |
470 | } |
471 | |
472 | return rc; |
473 | } |
474 | |
475 | |
476 | static ssize_t vmlogrdr_read(struct file *filp, char __user *data, |
477 | size_t count, loff_t * ppos) |
478 | { |
479 | int rc; |
480 | struct vmlogrdr_priv_t * priv = filp->private_data; |
481 | |
482 | while (priv->buffer_free) { |
483 | rc = vmlogrdr_receive_data(priv); |
484 | if (rc) { |
485 | rc = wait_event_interruptible(read_wait_queue, |
486 | atomic_read(&priv->receive_ready)); |
487 | if (rc) |
488 | return rc; |
489 | } |
490 | } |
491 | /* copy only up to end of record */ |
492 | if (count > priv->remaining) |
493 | count = priv->remaining; |
494 | |
495 | if (copy_to_user(to: data, from: priv->current_position, n: count)) |
496 | return -EFAULT; |
497 | |
498 | *ppos += count; |
499 | priv->current_position += count; |
500 | priv->remaining -= count; |
501 | |
502 | /* if all data has been transferred, set buffer free */ |
503 | if (priv->remaining == 0) |
504 | priv->buffer_free = 1; |
505 | |
506 | return count; |
507 | } |
508 | |
509 | static ssize_t vmlogrdr_autopurge_store(struct device * dev, |
510 | struct device_attribute *attr, |
511 | const char * buf, size_t count) |
512 | { |
513 | struct vmlogrdr_priv_t *priv = dev_get_drvdata(dev); |
514 | ssize_t ret = count; |
515 | |
516 | switch (buf[0]) { |
517 | case '0': |
518 | priv->autopurge=0; |
519 | break; |
520 | case '1': |
521 | priv->autopurge=1; |
522 | break; |
523 | default: |
524 | ret = -EINVAL; |
525 | } |
526 | return ret; |
527 | } |
528 | |
529 | |
530 | static ssize_t vmlogrdr_autopurge_show(struct device *dev, |
531 | struct device_attribute *attr, |
532 | char *buf) |
533 | { |
534 | struct vmlogrdr_priv_t *priv = dev_get_drvdata(dev); |
535 | return sprintf(buf, fmt: "%u\n" , priv->autopurge); |
536 | } |
537 | |
538 | |
539 | static DEVICE_ATTR(autopurge, 0644, vmlogrdr_autopurge_show, |
540 | vmlogrdr_autopurge_store); |
541 | |
542 | |
543 | static ssize_t vmlogrdr_purge_store(struct device * dev, |
544 | struct device_attribute *attr, |
545 | const char * buf, size_t count) |
546 | { |
547 | |
548 | char cp_command[80]; |
549 | char cp_response[80]; |
550 | struct vmlogrdr_priv_t *priv = dev_get_drvdata(dev); |
551 | |
552 | if (buf[0] != '1') |
553 | return -EINVAL; |
554 | |
555 | memset(cp_command, 0x00, sizeof(cp_command)); |
556 | memset(cp_response, 0x00, sizeof(cp_response)); |
557 | |
558 | /* |
559 | * The recording command needs to be called with option QID |
560 | * for guests that have previlege classes A or B. |
561 | * Other guests will not recognize the command and we have to |
562 | * issue the same command without the QID parameter. |
563 | */ |
564 | |
565 | if (recording_class_AB) |
566 | snprintf(buf: cp_command, size: sizeof(cp_command), |
567 | fmt: "RECORDING %s PURGE QID * " , |
568 | priv->recording_name); |
569 | else |
570 | snprintf(buf: cp_command, size: sizeof(cp_command), |
571 | fmt: "RECORDING %s PURGE " , |
572 | priv->recording_name); |
573 | |
574 | cpcmd(cp_command, cp_response, sizeof(cp_response), NULL); |
575 | |
576 | return count; |
577 | } |
578 | |
579 | |
580 | static DEVICE_ATTR(purge, 0200, NULL, vmlogrdr_purge_store); |
581 | |
582 | |
583 | static ssize_t vmlogrdr_autorecording_store(struct device *dev, |
584 | struct device_attribute *attr, |
585 | const char *buf, size_t count) |
586 | { |
587 | struct vmlogrdr_priv_t *priv = dev_get_drvdata(dev); |
588 | ssize_t ret = count; |
589 | |
590 | switch (buf[0]) { |
591 | case '0': |
592 | priv->autorecording=0; |
593 | break; |
594 | case '1': |
595 | priv->autorecording=1; |
596 | break; |
597 | default: |
598 | ret = -EINVAL; |
599 | } |
600 | return ret; |
601 | } |
602 | |
603 | |
604 | static ssize_t vmlogrdr_autorecording_show(struct device *dev, |
605 | struct device_attribute *attr, |
606 | char *buf) |
607 | { |
608 | struct vmlogrdr_priv_t *priv = dev_get_drvdata(dev); |
609 | return sprintf(buf, fmt: "%u\n" , priv->autorecording); |
610 | } |
611 | |
612 | |
613 | static DEVICE_ATTR(autorecording, 0644, vmlogrdr_autorecording_show, |
614 | vmlogrdr_autorecording_store); |
615 | |
616 | |
617 | static ssize_t vmlogrdr_recording_store(struct device * dev, |
618 | struct device_attribute *attr, |
619 | const char * buf, size_t count) |
620 | { |
621 | struct vmlogrdr_priv_t *priv = dev_get_drvdata(dev); |
622 | ssize_t ret; |
623 | |
624 | switch (buf[0]) { |
625 | case '0': |
626 | ret = vmlogrdr_recording(logptr: priv,action: 0,purge: 0); |
627 | break; |
628 | case '1': |
629 | ret = vmlogrdr_recording(logptr: priv,action: 1,purge: 0); |
630 | break; |
631 | default: |
632 | ret = -EINVAL; |
633 | } |
634 | if (ret) |
635 | return ret; |
636 | else |
637 | return count; |
638 | |
639 | } |
640 | |
641 | |
642 | static DEVICE_ATTR(recording, 0200, NULL, vmlogrdr_recording_store); |
643 | |
644 | |
645 | static ssize_t recording_status_show(struct device_driver *driver, char *buf) |
646 | { |
647 | static const char cp_command[] = "QUERY RECORDING " ; |
648 | int len; |
649 | |
650 | cpcmd(cp_command, buf, 4096, NULL); |
651 | len = strlen(buf); |
652 | return len; |
653 | } |
654 | static DRIVER_ATTR_RO(recording_status); |
655 | static struct attribute *vmlogrdr_drv_attrs[] = { |
656 | &driver_attr_recording_status.attr, |
657 | NULL, |
658 | }; |
659 | static struct attribute_group vmlogrdr_drv_attr_group = { |
660 | .attrs = vmlogrdr_drv_attrs, |
661 | }; |
662 | static const struct attribute_group *vmlogrdr_drv_attr_groups[] = { |
663 | &vmlogrdr_drv_attr_group, |
664 | NULL, |
665 | }; |
666 | |
667 | static struct attribute *vmlogrdr_attrs[] = { |
668 | &dev_attr_autopurge.attr, |
669 | &dev_attr_purge.attr, |
670 | &dev_attr_autorecording.attr, |
671 | &dev_attr_recording.attr, |
672 | NULL, |
673 | }; |
674 | static struct attribute_group vmlogrdr_attr_group = { |
675 | .attrs = vmlogrdr_attrs, |
676 | }; |
677 | static const struct attribute_group *vmlogrdr_attr_groups[] = { |
678 | &vmlogrdr_attr_group, |
679 | NULL, |
680 | }; |
681 | |
682 | static struct class *vmlogrdr_class; |
683 | static struct device_driver vmlogrdr_driver = { |
684 | .name = "vmlogrdr" , |
685 | .bus = &iucv_bus, |
686 | .groups = vmlogrdr_drv_attr_groups, |
687 | }; |
688 | |
689 | static int vmlogrdr_register_driver(void) |
690 | { |
691 | int ret; |
692 | |
693 | /* Register with iucv driver */ |
694 | ret = iucv_register(handler: &vmlogrdr_iucv_handler, smp: 1); |
695 | if (ret) |
696 | goto out; |
697 | |
698 | ret = driver_register(drv: &vmlogrdr_driver); |
699 | if (ret) |
700 | goto out_iucv; |
701 | |
702 | vmlogrdr_class = class_create(name: "vmlogrdr" ); |
703 | if (IS_ERR(ptr: vmlogrdr_class)) { |
704 | ret = PTR_ERR(ptr: vmlogrdr_class); |
705 | vmlogrdr_class = NULL; |
706 | goto out_driver; |
707 | } |
708 | return 0; |
709 | |
710 | out_driver: |
711 | driver_unregister(drv: &vmlogrdr_driver); |
712 | out_iucv: |
713 | iucv_unregister(handle: &vmlogrdr_iucv_handler, smp: 1); |
714 | out: |
715 | return ret; |
716 | } |
717 | |
718 | |
719 | static void vmlogrdr_unregister_driver(void) |
720 | { |
721 | class_destroy(cls: vmlogrdr_class); |
722 | vmlogrdr_class = NULL; |
723 | driver_unregister(drv: &vmlogrdr_driver); |
724 | iucv_unregister(handle: &vmlogrdr_iucv_handler, smp: 1); |
725 | } |
726 | |
727 | |
728 | static int vmlogrdr_register_device(struct vmlogrdr_priv_t *priv) |
729 | { |
730 | struct device *dev; |
731 | int ret; |
732 | |
733 | dev = kzalloc(size: sizeof(struct device), GFP_KERNEL); |
734 | if (dev) { |
735 | dev_set_name(dev, name: "%s" , priv->internal_name); |
736 | dev->bus = &iucv_bus; |
737 | dev->parent = iucv_root; |
738 | dev->driver = &vmlogrdr_driver; |
739 | dev->groups = vmlogrdr_attr_groups; |
740 | dev_set_drvdata(dev, data: priv); |
741 | /* |
742 | * The release function could be called after the |
743 | * module has been unloaded. It's _only_ task is to |
744 | * free the struct. Therefore, we specify kfree() |
745 | * directly here. (Probably a little bit obfuscating |
746 | * but legitime ...). |
747 | */ |
748 | dev->release = (void (*)(struct device *))kfree; |
749 | } else |
750 | return -ENOMEM; |
751 | ret = device_register(dev); |
752 | if (ret) { |
753 | put_device(dev); |
754 | return ret; |
755 | } |
756 | |
757 | priv->class_device = device_create(cls: vmlogrdr_class, parent: dev, |
758 | MKDEV(vmlogrdr_major, |
759 | priv->minor_num), |
760 | drvdata: priv, fmt: "%s" , dev_name(dev)); |
761 | if (IS_ERR(ptr: priv->class_device)) { |
762 | ret = PTR_ERR(ptr: priv->class_device); |
763 | priv->class_device=NULL; |
764 | device_unregister(dev); |
765 | return ret; |
766 | } |
767 | priv->device = dev; |
768 | return 0; |
769 | } |
770 | |
771 | |
772 | static int vmlogrdr_unregister_device(struct vmlogrdr_priv_t *priv) |
773 | { |
774 | device_destroy(cls: vmlogrdr_class, MKDEV(vmlogrdr_major, priv->minor_num)); |
775 | if (priv->device != NULL) { |
776 | device_unregister(dev: priv->device); |
777 | priv->device=NULL; |
778 | } |
779 | return 0; |
780 | } |
781 | |
782 | |
783 | static int vmlogrdr_register_cdev(dev_t dev) |
784 | { |
785 | int rc = 0; |
786 | vmlogrdr_cdev = cdev_alloc(); |
787 | if (!vmlogrdr_cdev) { |
788 | return -ENOMEM; |
789 | } |
790 | vmlogrdr_cdev->owner = THIS_MODULE; |
791 | vmlogrdr_cdev->ops = &vmlogrdr_fops; |
792 | rc = cdev_add(vmlogrdr_cdev, dev, MAXMINOR); |
793 | if (!rc) |
794 | return 0; |
795 | |
796 | // cleanup: cdev is not fully registered, no cdev_del here! |
797 | kobject_put(kobj: &vmlogrdr_cdev->kobj); |
798 | vmlogrdr_cdev=NULL; |
799 | return rc; |
800 | } |
801 | |
802 | |
803 | static void vmlogrdr_cleanup(void) |
804 | { |
805 | int i; |
806 | |
807 | if (vmlogrdr_cdev) { |
808 | cdev_del(vmlogrdr_cdev); |
809 | vmlogrdr_cdev=NULL; |
810 | } |
811 | for (i=0; i < MAXMINOR; ++i ) { |
812 | vmlogrdr_unregister_device(priv: &sys_ser[i]); |
813 | free_page((unsigned long)sys_ser[i].buffer); |
814 | } |
815 | vmlogrdr_unregister_driver(); |
816 | if (vmlogrdr_major) { |
817 | unregister_chrdev_region(MKDEV(vmlogrdr_major, 0), MAXMINOR); |
818 | vmlogrdr_major=0; |
819 | } |
820 | } |
821 | |
822 | |
823 | static int __init vmlogrdr_init(void) |
824 | { |
825 | int rc; |
826 | int i; |
827 | dev_t dev; |
828 | |
829 | if (! MACHINE_IS_VM) { |
830 | pr_err("not running under VM, driver not loaded.\n" ); |
831 | return -ENODEV; |
832 | } |
833 | |
834 | recording_class_AB = vmlogrdr_get_recording_class_AB(); |
835 | |
836 | rc = alloc_chrdev_region(&dev, 0, MAXMINOR, "vmlogrdr" ); |
837 | if (rc) |
838 | return rc; |
839 | vmlogrdr_major = MAJOR(dev); |
840 | |
841 | rc=vmlogrdr_register_driver(); |
842 | if (rc) |
843 | goto cleanup; |
844 | |
845 | for (i=0; i < MAXMINOR; ++i ) { |
846 | sys_ser[i].buffer = (char *) get_zeroed_page(GFP_KERNEL | GFP_DMA); |
847 | if (!sys_ser[i].buffer) { |
848 | rc = -ENOMEM; |
849 | break; |
850 | } |
851 | sys_ser[i].current_position = sys_ser[i].buffer; |
852 | rc=vmlogrdr_register_device(priv: &sys_ser[i]); |
853 | if (rc) |
854 | break; |
855 | } |
856 | if (rc) |
857 | goto cleanup; |
858 | |
859 | rc = vmlogrdr_register_cdev(dev); |
860 | if (rc) |
861 | goto cleanup; |
862 | return 0; |
863 | |
864 | cleanup: |
865 | vmlogrdr_cleanup(); |
866 | return rc; |
867 | } |
868 | |
869 | |
870 | static void __exit vmlogrdr_exit(void) |
871 | { |
872 | vmlogrdr_cleanup(); |
873 | return; |
874 | } |
875 | |
876 | |
877 | module_init(vmlogrdr_init); |
878 | module_exit(vmlogrdr_exit); |
879 | |