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1 /*
2 * Linux driver for System z and s390 unit record devices
3 * (z/VM virtual punch, reader, printer)
4 *
5 * Copyright IBM Corp. 2001, 2009
6 * Authors: Malcolm Beattie <beattiem@uk.ibm.com>
7 * Michael Holzheu <holzheu@de.ibm.com>
8 * Frank Munzert <munzert@de.ibm.com>
9 */
10
11 #define KMSG_COMPONENT "vmur"
12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
13
14 #include <linux/kernel_stat.h>
15 #include <linux/cdev.h>
16 #include <linux/slab.h>
17 #include <linux/module.h>
18
19 #include <asm/uaccess.h>
20 #include <asm/cio.h>
21 #include <asm/ccwdev.h>
22 #include <asm/debug.h>
23 #include <asm/diag.h>
24
25 #include "vmur.h"
26
27 /*
28 * Driver overview
29 *
30 * Unit record device support is implemented as a character device driver.
31 * We can fit at least 16 bits into a device minor number and use the
32 * simple method of mapping a character device number with minor abcd
33 * to the unit record device with devno abcd.
34 * I/O to virtual unit record devices is handled as follows:
35 * Reads: Diagnose code 0x14 (input spool file manipulation)
36 * is used to read spool data page-wise.
37 * Writes: The CCW used is WRITE_CCW_CMD (0x01). The device's record length
38 * is available by reading sysfs attr reclen. Each write() to the device
39 * must specify an integral multiple (maximal 511) of reclen.
40 */
41
42 static char ur_banner[] = "z/VM virtual unit record device driver";
43
44 MODULE_AUTHOR("IBM Corporation");
45 MODULE_DESCRIPTION("s390 z/VM virtual unit record device driver");
46 MODULE_LICENSE("GPL");
47
48 static dev_t ur_first_dev_maj_min;
49 static struct class *vmur_class;
50 static struct debug_info *vmur_dbf;
51
52 /* We put the device's record length (for writes) in the driver_info field */
53 static struct ccw_device_id ur_ids[] = {
54 { CCWDEV_CU_DI(READER_PUNCH_DEVTYPE, 80) },
55 { CCWDEV_CU_DI(PRINTER_DEVTYPE, 132) },
56 { /* end of list */ }
57 };
58
59 MODULE_DEVICE_TABLE(ccw, ur_ids);
60
61 static int ur_probe(struct ccw_device *cdev);
62 static void ur_remove(struct ccw_device *cdev);
63 static int ur_set_online(struct ccw_device *cdev);
64 static int ur_set_offline(struct ccw_device *cdev);
65 static int ur_pm_suspend(struct ccw_device *cdev);
66
67 static struct ccw_driver ur_driver = {
68 .driver = {
69 .name = "vmur",
70 .owner = THIS_MODULE,
71 },
72 .ids = ur_ids,
73 .probe = ur_probe,
74 .remove = ur_remove,
75 .set_online = ur_set_online,
76 .set_offline = ur_set_offline,
77 .freeze = ur_pm_suspend,
78 };
79
80 static DEFINE_MUTEX(vmur_mutex);
81
82 /*
83 * Allocation, freeing, getting and putting of urdev structures
84 *
85 * Each ur device (urd) contains a reference to its corresponding ccw device
86 * (cdev) using the urd->cdev pointer. Each ccw device has a reference to the
87 * ur device using dev_get_drvdata(&cdev->dev) pointer.
88 *
89 * urd references:
90 * - ur_probe gets a urd reference, ur_remove drops the reference
91 * dev_get_drvdata(&cdev->dev)
92 * - ur_open gets a urd reference, ur_relase drops the reference
93 * (urf->urd)
94 *
95 * cdev references:
96 * - urdev_alloc get a cdev reference (urd->cdev)
97 * - urdev_free drops the cdev reference (urd->cdev)
98 *
99 * Setting and clearing of dev_get_drvdata(&cdev->dev) is protected by the ccwdev lock
100 */
101 static struct urdev *urdev_alloc(struct ccw_device *cdev)
102 {
103 struct urdev *urd;
104
105 urd = kzalloc(sizeof(struct urdev), GFP_KERNEL);
106 if (!urd)
107 return NULL;
108 urd->reclen = cdev->id.driver_info;
109 ccw_device_get_id(cdev, &urd->dev_id);
110 mutex_init(&urd->io_mutex);
111 init_waitqueue_head(&urd->wait);
112 spin_lock_init(&urd->open_lock);
113 atomic_set(&urd->ref_count, 1);
114 urd->cdev = cdev;
115 get_device(&cdev->dev);
116 return urd;
117 }
118
119 static void urdev_free(struct urdev *urd)
120 {
121 TRACE("urdev_free: %p\n", urd);
122 if (urd->cdev)
123 put_device(&urd->cdev->dev);
124 kfree(urd);
125 }
126
127 static void urdev_get(struct urdev *urd)
128 {
129 atomic_inc(&urd->ref_count);
130 }
131
132 static struct urdev *urdev_get_from_cdev(struct ccw_device *cdev)
133 {
134 struct urdev *urd;
135 unsigned long flags;
136
137 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
138 urd = dev_get_drvdata(&cdev->dev);
139 if (urd)
140 urdev_get(urd);
141 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
142 return urd;
143 }
144
145 static struct urdev *urdev_get_from_devno(u16 devno)
146 {
147 char bus_id[16];
148 struct ccw_device *cdev;
149 struct urdev *urd;
150
151 sprintf(bus_id, "0.0.%04x", devno);
152 cdev = get_ccwdev_by_busid(&ur_driver, bus_id);
153 if (!cdev)
154 return NULL;
155 urd = urdev_get_from_cdev(cdev);
156 put_device(&cdev->dev);
157 return urd;
158 }
159
160 static void urdev_put(struct urdev *urd)
161 {
162 if (atomic_dec_and_test(&urd->ref_count))
163 urdev_free(urd);
164 }
165
166 /*
167 * State and contents of ur devices can be changed by class D users issuing
168 * CP commands such as PURGE or TRANSFER, while the Linux guest is suspended.
169 * Also the Linux guest might be logged off, which causes all active spool
170 * files to be closed.
171 * So we cannot guarantee that spool files are still the same when the Linux
172 * guest is resumed. In order to avoid unpredictable results at resume time
173 * we simply refuse to suspend if a ur device node is open.
174 */
175 static int ur_pm_suspend(struct ccw_device *cdev)
176 {
177 struct urdev *urd = dev_get_drvdata(&cdev->dev);
178
179 TRACE("ur_pm_suspend: cdev=%p\n", cdev);
180 if (urd->open_flag) {
181 pr_err("Unit record device %s is busy, %s refusing to "
182 "suspend.\n", dev_name(&cdev->dev), ur_banner);
183 return -EBUSY;
184 }
185 return 0;
186 }
187
188 /*
189 * Low-level functions to do I/O to a ur device.
190 * alloc_chan_prog
191 * free_chan_prog
192 * do_ur_io
193 * ur_int_handler
194 *
195 * alloc_chan_prog allocates and builds the channel program
196 * free_chan_prog frees memory of the channel program
197 *
198 * do_ur_io issues the channel program to the device and blocks waiting
199 * on a completion event it publishes at urd->io_done. The function
200 * serialises itself on the device's mutex so that only one I/O
201 * is issued at a time (and that I/O is synchronous).
202 *
203 * ur_int_handler catches the "I/O done" interrupt, writes the
204 * subchannel status word into the scsw member of the urdev structure
205 * and complete()s the io_done to wake the waiting do_ur_io.
206 *
207 * The caller of do_ur_io is responsible for kfree()ing the channel program
208 * address pointer that alloc_chan_prog returned.
209 */
210
211 static void free_chan_prog(struct ccw1 *cpa)
212 {
213 struct ccw1 *ptr = cpa;
214
215 while (ptr->cda) {
216 kfree((void *)(addr_t) ptr->cda);
217 ptr++;
218 }
219 kfree(cpa);
220 }
221
222 /*
223 * alloc_chan_prog
224 * The channel program we use is write commands chained together
225 * with a final NOP CCW command-chained on (which ensures that CE and DE
226 * are presented together in a single interrupt instead of as separate
227 * interrupts unless an incorrect length indication kicks in first). The
228 * data length in each CCW is reclen.
229 */
230 static struct ccw1 *alloc_chan_prog(const char __user *ubuf, int rec_count,
231 int reclen)
232 {
233 struct ccw1 *cpa;
234 void *kbuf;
235 int i;
236
237 TRACE("alloc_chan_prog(%p, %i, %i)\n", ubuf, rec_count, reclen);
238
239 /*
240 * We chain a NOP onto the writes to force CE+DE together.
241 * That means we allocate room for CCWs to cover count/reclen
242 * records plus a NOP.
243 */
244 cpa = kzalloc((rec_count + 1) * sizeof(struct ccw1),
245 GFP_KERNEL | GFP_DMA);
246 if (!cpa)
247 return ERR_PTR(-ENOMEM);
248
249 for (i = 0; i < rec_count; i++) {
250 cpa[i].cmd_code = WRITE_CCW_CMD;
251 cpa[i].flags = CCW_FLAG_CC | CCW_FLAG_SLI;
252 cpa[i].count = reclen;
253 kbuf = kmalloc(reclen, GFP_KERNEL | GFP_DMA);
254 if (!kbuf) {
255 free_chan_prog(cpa);
256 return ERR_PTR(-ENOMEM);
257 }
258 cpa[i].cda = (u32)(addr_t) kbuf;
259 if (copy_from_user(kbuf, ubuf, reclen)) {
260 free_chan_prog(cpa);
261 return ERR_PTR(-EFAULT);
262 }
263 ubuf += reclen;
264 }
265 /* The following NOP CCW forces CE+DE to be presented together */
266 cpa[i].cmd_code = CCW_CMD_NOOP;
267 return cpa;
268 }
269
270 static int do_ur_io(struct urdev *urd, struct ccw1 *cpa)
271 {
272 int rc;
273 struct ccw_device *cdev = urd->cdev;
274 DECLARE_COMPLETION_ONSTACK(event);
275
276 TRACE("do_ur_io: cpa=%p\n", cpa);
277
278 rc = mutex_lock_interruptible(&urd->io_mutex);
279 if (rc)
280 return rc;
281
282 urd->io_done = &event;
283
284 spin_lock_irq(get_ccwdev_lock(cdev));
285 rc = ccw_device_start(cdev, cpa, 1, 0, 0);
286 spin_unlock_irq(get_ccwdev_lock(cdev));
287
288 TRACE("do_ur_io: ccw_device_start returned %d\n", rc);
289 if (rc)
290 goto out;
291
292 wait_for_completion(&event);
293 TRACE("do_ur_io: I/O complete\n");
294 rc = 0;
295
296 out:
297 mutex_unlock(&urd->io_mutex);
298 return rc;
299 }
300
301 /*
302 * ur interrupt handler, called from the ccw_device layer
303 */
304 static void ur_int_handler(struct ccw_device *cdev, unsigned long intparm,
305 struct irb *irb)
306 {
307 struct urdev *urd;
308
309 kstat_cpu(smp_processor_id()).irqs[IOINT_VMR]++;
310 TRACE("ur_int_handler: intparm=0x%lx cstat=%02x dstat=%02x res=%u\n",
311 intparm, irb->scsw.cmd.cstat, irb->scsw.cmd.dstat,
312 irb->scsw.cmd.count);
313
314 if (!intparm) {
315 TRACE("ur_int_handler: unsolicited interrupt\n");
316 return;
317 }
318 urd = dev_get_drvdata(&cdev->dev);
319 BUG_ON(!urd);
320 /* On special conditions irb is an error pointer */
321 if (IS_ERR(irb))
322 urd->io_request_rc = PTR_ERR(irb);
323 else if (irb->scsw.cmd.dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END))
324 urd->io_request_rc = 0;
325 else
326 urd->io_request_rc = -EIO;
327
328 complete(urd->io_done);
329 }
330
331 /*
332 * reclen sysfs attribute - The record length to be used for write CCWs
333 */
334 static ssize_t ur_attr_reclen_show(struct device *dev,
335 struct device_attribute *attr, char *buf)
336 {
337 struct urdev *urd;
338 int rc;
339
340 urd = urdev_get_from_cdev(to_ccwdev(dev));
341 if (!urd)
342 return -ENODEV;
343 rc = sprintf(buf, "%zu\n", urd->reclen);
344 urdev_put(urd);
345 return rc;
346 }
347
348 static DEVICE_ATTR(reclen, 0444, ur_attr_reclen_show, NULL);
349
350 static int ur_create_attributes(struct device *dev)
351 {
352 return device_create_file(dev, &dev_attr_reclen);
353 }
354
355 static void ur_remove_attributes(struct device *dev)
356 {
357 device_remove_file(dev, &dev_attr_reclen);
358 }
359
360 /*
361 * diagnose code 0x210 - retrieve device information
362 * cc=0 normal completion, we have a real device
363 * cc=1 CP paging error
364 * cc=2 The virtual device exists, but is not associated with a real device
365 * cc=3 Invalid device address, or the virtual device does not exist
366 */
367 static int get_urd_class(struct urdev *urd)
368 {
369 static struct diag210 ur_diag210;
370 int cc;
371
372 ur_diag210.vrdcdvno = urd->dev_id.devno;
373 ur_diag210.vrdclen = sizeof(struct diag210);
374
375 cc = diag210(&ur_diag210);
376 switch (cc) {
377 case 0:
378 return -EOPNOTSUPP;
379 case 2:
380 return ur_diag210.vrdcvcla; /* virtual device class */
381 case 3:
382 return -ENODEV;
383 default:
384 return -EIO;
385 }
386 }
387
388 /*
389 * Allocation and freeing of urfile structures
390 */
391 static struct urfile *urfile_alloc(struct urdev *urd)
392 {
393 struct urfile *urf;
394
395 urf = kzalloc(sizeof(struct urfile), GFP_KERNEL);
396 if (!urf)
397 return NULL;
398 urf->urd = urd;
399
400 TRACE("urfile_alloc: urd=%p urf=%p rl=%zu\n", urd, urf,
401 urf->dev_reclen);
402
403 return urf;
404 }
405
406 static void urfile_free(struct urfile *urf)
407 {
408 TRACE("urfile_free: urf=%p urd=%p\n", urf, urf->urd);
409 kfree(urf);
410 }
411
412 /*
413 * The fops implementation of the character device driver
414 */
415 static ssize_t do_write(struct urdev *urd, const char __user *udata,
416 size_t count, size_t reclen, loff_t *ppos)
417 {
418 struct ccw1 *cpa;
419 int rc;
420
421 cpa = alloc_chan_prog(udata, count / reclen, reclen);
422 if (IS_ERR(cpa))
423 return PTR_ERR(cpa);
424
425 rc = do_ur_io(urd, cpa);
426 if (rc)
427 goto fail_kfree_cpa;
428
429 if (urd->io_request_rc) {
430 rc = urd->io_request_rc;
431 goto fail_kfree_cpa;
432 }
433 *ppos += count;
434 rc = count;
435
436 fail_kfree_cpa:
437 free_chan_prog(cpa);
438 return rc;
439 }
440
441 static ssize_t ur_write(struct file *file, const char __user *udata,
442 size_t count, loff_t *ppos)
443 {
444 struct urfile *urf = file->private_data;
445
446 TRACE("ur_write: count=%zu\n", count);
447
448 if (count == 0)
449 return 0;
450
451 if (count % urf->dev_reclen)
452 return -EINVAL; /* count must be a multiple of reclen */
453
454 if (count > urf->dev_reclen * MAX_RECS_PER_IO)
455 count = urf->dev_reclen * MAX_RECS_PER_IO;
456
457 return do_write(urf->urd, udata, count, urf->dev_reclen, ppos);
458 }
459
460 /*
461 * diagnose code 0x14 subcode 0x0028 - position spool file to designated
462 * record
463 * cc=0 normal completion
464 * cc=2 no file active on the virtual reader or device not ready
465 * cc=3 record specified is beyond EOF
466 */
467 static int diag_position_to_record(int devno, int record)
468 {
469 int cc;
470
471 cc = diag14(record, devno, 0x28);
472 switch (cc) {
473 case 0:
474 return 0;
475 case 2:
476 return -ENOMEDIUM;
477 case 3:
478 return -ENODATA; /* position beyond end of file */
479 default:
480 return -EIO;
481 }
482 }
483
484 /*
485 * diagnose code 0x14 subcode 0x0000 - read next spool file buffer
486 * cc=0 normal completion
487 * cc=1 EOF reached
488 * cc=2 no file active on the virtual reader, and no file eligible
489 * cc=3 file already active on the virtual reader or specified virtual
490 * reader does not exist or is not a reader
491 */
492 static int diag_read_file(int devno, char *buf)
493 {
494 int cc;
495
496 cc = diag14((unsigned long) buf, devno, 0x00);
497 switch (cc) {
498 case 0:
499 return 0;
500 case 1:
501 return -ENODATA;
502 case 2:
503 return -ENOMEDIUM;
504 default:
505 return -EIO;
506 }
507 }
508
509 static ssize_t diag14_read(struct file *file, char __user *ubuf, size_t count,
510 loff_t *offs)
511 {
512 size_t len, copied, res;
513 char *buf;
514 int rc;
515 u16 reclen;
516 struct urdev *urd;
517
518 urd = ((struct urfile *) file->private_data)->urd;
519 reclen = ((struct urfile *) file->private_data)->file_reclen;
520
521 rc = diag_position_to_record(urd->dev_id.devno, *offs / PAGE_SIZE + 1);
522 if (rc == -ENODATA)
523 return 0;
524 if (rc)
525 return rc;
526
527 len = min((size_t) PAGE_SIZE, count);
528 buf = (char *) __get_free_page(GFP_KERNEL | GFP_DMA);
529 if (!buf)
530 return -ENOMEM;
531
532 copied = 0;
533 res = (size_t) (*offs % PAGE_SIZE);
534 do {
535 rc = diag_read_file(urd->dev_id.devno, buf);
536 if (rc == -ENODATA) {
537 break;
538 }
539 if (rc)
540 goto fail;
541 if (reclen && (copied == 0) && (*offs < PAGE_SIZE))
542 *((u16 *) &buf[FILE_RECLEN_OFFSET]) = reclen;
543 len = min(count - copied, PAGE_SIZE - res);
544 if (copy_to_user(ubuf + copied, buf + res, len)) {
545 rc = -EFAULT;
546 goto fail;
547 }
548 res = 0;
549 copied += len;
550 } while (copied != count);
551
552 *offs += copied;
553 rc = copied;
554 fail:
555 free_page((unsigned long) buf);
556 return rc;
557 }
558
559 static ssize_t ur_read(struct file *file, char __user *ubuf, size_t count,
560 loff_t *offs)
561 {
562 struct urdev *urd;
563 int rc;
564
565 TRACE("ur_read: count=%zu ppos=%li\n", count, (unsigned long) *offs);
566
567 if (count == 0)
568 return 0;
569
570 urd = ((struct urfile *) file->private_data)->urd;
571 rc = mutex_lock_interruptible(&urd->io_mutex);
572 if (rc)
573 return rc;
574 rc = diag14_read(file, ubuf, count, offs);
575 mutex_unlock(&urd->io_mutex);
576 return rc;
577 }
578
579 /*
580 * diagnose code 0x14 subcode 0x0fff - retrieve next file descriptor
581 * cc=0 normal completion
582 * cc=1 no files on reader queue or no subsequent file
583 * cc=2 spid specified is invalid
584 */
585 static int diag_read_next_file_info(struct file_control_block *buf, int spid)
586 {
587 int cc;
588
589 cc = diag14((unsigned long) buf, spid, 0xfff);
590 switch (cc) {
591 case 0:
592 return 0;
593 default:
594 return -ENODATA;
595 }
596 }
597
598 static int verify_uri_device(struct urdev *urd)
599 {
600 struct file_control_block *fcb;
601 char *buf;
602 int rc;
603
604 fcb = kmalloc(sizeof(*fcb), GFP_KERNEL | GFP_DMA);
605 if (!fcb)
606 return -ENOMEM;
607
608 /* check for empty reader device (beginning of chain) */
609 rc = diag_read_next_file_info(fcb, 0);
610 if (rc)
611 goto fail_free_fcb;
612
613 /* if file is in hold status, we do not read it */
614 if (fcb->file_stat & (FLG_SYSTEM_HOLD | FLG_USER_HOLD)) {
615 rc = -EPERM;
616 goto fail_free_fcb;
617 }
618
619 /* open file on virtual reader */
620 buf = (char *) __get_free_page(GFP_KERNEL | GFP_DMA);
621 if (!buf) {
622 rc = -ENOMEM;
623 goto fail_free_fcb;
624 }
625 rc = diag_read_file(urd->dev_id.devno, buf);
626 if ((rc != 0) && (rc != -ENODATA)) /* EOF does not hurt */
627 goto fail_free_buf;
628
629 /* check if the file on top of the queue is open now */
630 rc = diag_read_next_file_info(fcb, 0);
631 if (rc)
632 goto fail_free_buf;
633 if (!(fcb->file_stat & FLG_IN_USE)) {
634 rc = -EMFILE;
635 goto fail_free_buf;
636 }
637 rc = 0;
638
639 fail_free_buf:
640 free_page((unsigned long) buf);
641 fail_free_fcb:
642 kfree(fcb);
643 return rc;
644 }
645
646 static int verify_device(struct urdev *urd)
647 {
648 switch (urd->class) {
649 case DEV_CLASS_UR_O:
650 return 0; /* no check needed here */
651 case DEV_CLASS_UR_I:
652 return verify_uri_device(urd);
653 default:
654 return -EOPNOTSUPP;
655 }
656 }
657
658 static int get_uri_file_reclen(struct urdev *urd)
659 {
660 struct file_control_block *fcb;
661 int rc;
662
663 fcb = kmalloc(sizeof(*fcb), GFP_KERNEL | GFP_DMA);
664 if (!fcb)
665 return -ENOMEM;
666 rc = diag_read_next_file_info(fcb, 0);
667 if (rc)
668 goto fail_free;
669 if (fcb->file_stat & FLG_CP_DUMP)
670 rc = 0;
671 else
672 rc = fcb->rec_len;
673
674 fail_free:
675 kfree(fcb);
676 return rc;
677 }
678
679 static int get_file_reclen(struct urdev *urd)
680 {
681 switch (urd->class) {
682 case DEV_CLASS_UR_O:
683 return 0;
684 case DEV_CLASS_UR_I:
685 return get_uri_file_reclen(urd);
686 default:
687 return -EOPNOTSUPP;
688 }
689 }
690
691 static int ur_open(struct inode *inode, struct file *file)
692 {
693 u16 devno;
694 struct urdev *urd;
695 struct urfile *urf;
696 unsigned short accmode;
697 int rc;
698
699 accmode = file->f_flags & O_ACCMODE;
700
701 if (accmode == O_RDWR)
702 return -EACCES;
703 /*
704 * We treat the minor number as the devno of the ur device
705 * to find in the driver tree.
706 */
707 devno = MINOR(file->f_dentry->d_inode->i_rdev);
708
709 urd = urdev_get_from_devno(devno);
710 if (!urd) {
711 rc = -ENXIO;
712 goto out;
713 }
714
715 spin_lock(&urd->open_lock);
716 while (urd->open_flag) {
717 spin_unlock(&urd->open_lock);
718 if (file->f_flags & O_NONBLOCK) {
719 rc = -EBUSY;
720 goto fail_put;
721 }
722 if (wait_event_interruptible(urd->wait, urd->open_flag == 0)) {
723 rc = -ERESTARTSYS;
724 goto fail_put;
725 }
726 spin_lock(&urd->open_lock);
727 }
728 urd->open_flag++;
729 spin_unlock(&urd->open_lock);
730
731 TRACE("ur_open\n");
732
733 if (((accmode == O_RDONLY) && (urd->class != DEV_CLASS_UR_I)) ||
734 ((accmode == O_WRONLY) && (urd->class != DEV_CLASS_UR_O))) {
735 TRACE("ur_open: unsupported dev class (%d)\n", urd->class);
736 rc = -EACCES;
737 goto fail_unlock;
738 }
739
740 rc = verify_device(urd);
741 if (rc)
742 goto fail_unlock;
743
744 urf = urfile_alloc(urd);
745 if (!urf) {
746 rc = -ENOMEM;
747 goto fail_unlock;
748 }
749
750 urf->dev_reclen = urd->reclen;
751 rc = get_file_reclen(urd);
752 if (rc < 0)
753 goto fail_urfile_free;
754 urf->file_reclen = rc;
755 file->private_data = urf;
756 return 0;
757
758 fail_urfile_free:
759 urfile_free(urf);
760 fail_unlock:
761 spin_lock(&urd->open_lock);
762 urd->open_flag--;
763 spin_unlock(&urd->open_lock);
764 fail_put:
765 urdev_put(urd);
766 out:
767 return rc;
768 }
769
770 static int ur_release(struct inode *inode, struct file *file)
771 {
772 struct urfile *urf = file->private_data;
773
774 TRACE("ur_release\n");
775 spin_lock(&urf->urd->open_lock);
776 urf->urd->open_flag--;
777 spin_unlock(&urf->urd->open_lock);
778 wake_up_interruptible(&urf->urd->wait);
779 urdev_put(urf->urd);
780 urfile_free(urf);
781 return 0;
782 }
783
784 static loff_t ur_llseek(struct file *file, loff_t offset, int whence)
785 {
786 loff_t newpos;
787
788 if ((file->f_flags & O_ACCMODE) != O_RDONLY)
789 return -ESPIPE; /* seek allowed only for reader */
790 if (offset % PAGE_SIZE)
791 return -ESPIPE; /* only multiples of 4K allowed */
792 switch (whence) {
793 case 0: /* SEEK_SET */
794 newpos = offset;
795 break;
796 case 1: /* SEEK_CUR */
797 newpos = file->f_pos + offset;
798 break;
799 default:
800 return -EINVAL;
801 }
802 file->f_pos = newpos;
803 return newpos;
804 }
805
806 static const struct file_operations ur_fops = {
807 .owner = THIS_MODULE,
808 .open = ur_open,
809 .release = ur_release,
810 .read = ur_read,
811 .write = ur_write,
812 .llseek = ur_llseek,
813 };
814
815 /*
816 * ccw_device infrastructure:
817 * ur_probe creates the struct urdev (with refcount = 1), the device
818 * attributes, sets up the interrupt handler and validates the virtual
819 * unit record device.
820 * ur_remove removes the device attributes and drops the reference to
821 * struct urdev.
822 *
823 * ur_probe, ur_remove, ur_set_online and ur_set_offline are serialized
824 * by the vmur_mutex lock.
825 *
826 * urd->char_device is used as indication that the online function has
827 * been completed successfully.
828 */
829 static int ur_probe(struct ccw_device *cdev)
830 {
831 struct urdev *urd;
832 int rc;
833
834 TRACE("ur_probe: cdev=%p\n", cdev);
835
836 mutex_lock(&vmur_mutex);
837 urd = urdev_alloc(cdev);
838 if (!urd) {
839 rc = -ENOMEM;
840 goto fail_unlock;
841 }
842
843 rc = ur_create_attributes(&cdev->dev);
844 if (rc) {
845 rc = -ENOMEM;
846 goto fail_urdev_put;
847 }
848 cdev->handler = ur_int_handler;
849
850 /* validate virtual unit record device */
851 urd->class = get_urd_class(urd);
852 if (urd->class < 0) {
853 rc = urd->class;
854 goto fail_remove_attr;
855 }
856 if ((urd->class != DEV_CLASS_UR_I) && (urd->class != DEV_CLASS_UR_O)) {
857 rc = -EOPNOTSUPP;
858 goto fail_remove_attr;
859 }
860 spin_lock_irq(get_ccwdev_lock(cdev));
861 dev_set_drvdata(&cdev->dev, urd);
862 spin_unlock_irq(get_ccwdev_lock(cdev));
863
864 mutex_unlock(&vmur_mutex);
865 return 0;
866
867 fail_remove_attr:
868 ur_remove_attributes(&cdev->dev);
869 fail_urdev_put:
870 urdev_put(urd);
871 fail_unlock:
872 mutex_unlock(&vmur_mutex);
873 return rc;
874 }
875
876 static int ur_set_online(struct ccw_device *cdev)
877 {
878 struct urdev *urd;
879 int minor, major, rc;
880 char node_id[16];
881
882 TRACE("ur_set_online: cdev=%p\n", cdev);
883
884 mutex_lock(&vmur_mutex);
885 urd = urdev_get_from_cdev(cdev);
886 if (!urd) {
887 /* ur_remove already deleted our urd */
888 rc = -ENODEV;
889 goto fail_unlock;
890 }
891
892 if (urd->char_device) {
893 /* Another ur_set_online was faster */
894 rc = -EBUSY;
895 goto fail_urdev_put;
896 }
897
898 minor = urd->dev_id.devno;
899 major = MAJOR(ur_first_dev_maj_min);
900
901 urd->char_device = cdev_alloc();
902 if (!urd->char_device) {
903 rc = -ENOMEM;
904 goto fail_urdev_put;
905 }
906
907 cdev_init(urd->char_device, &ur_fops);
908 urd->char_device->dev = MKDEV(major, minor);
909 urd->char_device->owner = ur_fops.owner;
910
911 rc = cdev_add(urd->char_device, urd->char_device->dev, 1);
912 if (rc)
913 goto fail_free_cdev;
914 if (urd->cdev->id.cu_type == READER_PUNCH_DEVTYPE) {
915 if (urd->class == DEV_CLASS_UR_I)
916 sprintf(node_id, "vmrdr-%s", dev_name(&cdev->dev));
917 if (urd->class == DEV_CLASS_UR_O)
918 sprintf(node_id, "vmpun-%s", dev_name(&cdev->dev));
919 } else if (urd->cdev->id.cu_type == PRINTER_DEVTYPE) {
920 sprintf(node_id, "vmprt-%s", dev_name(&cdev->dev));
921 } else {
922 rc = -EOPNOTSUPP;
923 goto fail_free_cdev;
924 }
925
926 urd->device = device_create(vmur_class, NULL, urd->char_device->dev,
927 NULL, "%s", node_id);
928 if (IS_ERR(urd->device)) {
929 rc = PTR_ERR(urd->device);
930 TRACE("ur_set_online: device_create rc=%d\n", rc);
931 goto fail_free_cdev;
932 }
933 urdev_put(urd);
934 mutex_unlock(&vmur_mutex);
935 return 0;
936
937 fail_free_cdev:
938 cdev_del(urd->char_device);
939 urd->char_device = NULL;
940 fail_urdev_put:
941 urdev_put(urd);
942 fail_unlock:
943 mutex_unlock(&vmur_mutex);
944 return rc;
945 }
946
947 static int ur_set_offline_force(struct ccw_device *cdev, int force)
948 {
949 struct urdev *urd;
950 int rc;
951
952 TRACE("ur_set_offline: cdev=%p\n", cdev);
953 urd = urdev_get_from_cdev(cdev);
954 if (!urd)
955 /* ur_remove already deleted our urd */
956 return -ENODEV;
957 if (!urd->char_device) {
958 /* Another ur_set_offline was faster */
959 rc = -EBUSY;
960 goto fail_urdev_put;
961 }
962 if (!force && (atomic_read(&urd->ref_count) > 2)) {
963 /* There is still a user of urd (e.g. ur_open) */
964 TRACE("ur_set_offline: BUSY\n");
965 rc = -EBUSY;
966 goto fail_urdev_put;
967 }
968 device_destroy(vmur_class, urd->char_device->dev);
969 cdev_del(urd->char_device);
970 urd->char_device = NULL;
971 rc = 0;
972
973 fail_urdev_put:
974 urdev_put(urd);
975 return rc;
976 }
977
978 static int ur_set_offline(struct ccw_device *cdev)
979 {
980 int rc;
981
982 mutex_lock(&vmur_mutex);
983 rc = ur_set_offline_force(cdev, 0);
984 mutex_unlock(&vmur_mutex);
985 return rc;
986 }
987
988 static void ur_remove(struct ccw_device *cdev)
989 {
990 unsigned long flags;
991
992 TRACE("ur_remove\n");
993
994 mutex_lock(&vmur_mutex);
995
996 if (cdev->online)
997 ur_set_offline_force(cdev, 1);
998 ur_remove_attributes(&cdev->dev);
999
1000 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1001 urdev_put(dev_get_drvdata(&cdev->dev));
1002 dev_set_drvdata(&cdev->dev, NULL);
1003 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1004
1005 mutex_unlock(&vmur_mutex);
1006 }
1007
1008 /*
1009 * Module initialisation and cleanup
1010 */
1011 static int __init ur_init(void)
1012 {
1013 int rc;
1014 dev_t dev;
1015
1016 if (!MACHINE_IS_VM) {
1017 pr_err("The %s cannot be loaded without z/VM\n",
1018 ur_banner);
1019 return -ENODEV;
1020 }
1021
1022 vmur_dbf = debug_register("vmur", 4, 1, 4 * sizeof(long));
1023 if (!vmur_dbf)
1024 return -ENOMEM;
1025 rc = debug_register_view(vmur_dbf, &debug_sprintf_view);
1026 if (rc)
1027 goto fail_free_dbf;
1028
1029 debug_set_level(vmur_dbf, 6);
1030
1031 vmur_class = class_create(THIS_MODULE, "vmur");
1032 if (IS_ERR(vmur_class)) {
1033 rc = PTR_ERR(vmur_class);
1034 goto fail_free_dbf;
1035 }
1036
1037 rc = ccw_driver_register(&ur_driver);
1038 if (rc)
1039 goto fail_class_destroy;
1040
1041 rc = alloc_chrdev_region(&dev, 0, NUM_MINORS, "vmur");
1042 if (rc) {
1043 pr_err("Kernel function alloc_chrdev_region failed with "
1044 "error code %d\n", rc);
1045 goto fail_unregister_driver;
1046 }
1047 ur_first_dev_maj_min = MKDEV(MAJOR(dev), 0);
1048
1049 pr_info("%s loaded.\n", ur_banner);
1050 return 0;
1051
1052 fail_unregister_driver:
1053 ccw_driver_unregister(&ur_driver);
1054 fail_class_destroy:
1055 class_destroy(vmur_class);
1056 fail_free_dbf:
1057 debug_unregister(vmur_dbf);
1058 return rc;
1059 }
1060
1061 static void __exit ur_exit(void)
1062 {
1063 unregister_chrdev_region(ur_first_dev_maj_min, NUM_MINORS);
1064 ccw_driver_unregister(&ur_driver);
1065 class_destroy(vmur_class);
1066 debug_unregister(vmur_dbf);
1067 pr_info("%s unloaded.\n", ur_banner);
1068 }
1069
1070 module_init(ur_init);
1071 module_exit(ur_exit);