Version:  2.0.40 2.2.26 2.4.37 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18

Linux/drivers/s390/char/vmur.c

  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/cdev.h>
 15 #include <linux/slab.h>
 16 #include <linux/module.h>
 17 
 18 #include <asm/uaccess.h>
 19 #include <asm/cio.h>
 20 #include <asm/ccwdev.h>
 21 #include <asm/debug.h>
 22 #include <asm/diag.h>
 23 
 24 #include "vmur.h"
 25 
 26 /*
 27  * Driver overview
 28  *
 29  * Unit record device support is implemented as a character device driver.
 30  * We can fit at least 16 bits into a device minor number and use the
 31  * simple method of mapping a character device number with minor abcd
 32  * to the unit record device with devno abcd.
 33  * I/O to virtual unit record devices is handled as follows:
 34  * Reads: Diagnose code 0x14 (input spool file manipulation)
 35  * is used to read spool data page-wise.
 36  * Writes: The CCW used is WRITE_CCW_CMD (0x01). The device's record length
 37  * is available by reading sysfs attr reclen. Each write() to the device
 38  * must specify an integral multiple (maximal 511) of reclen.
 39  */
 40 
 41 static char ur_banner[] = "z/VM virtual unit record device driver";
 42 
 43 MODULE_AUTHOR("IBM Corporation");
 44 MODULE_DESCRIPTION("s390 z/VM virtual unit record device driver");
 45 MODULE_LICENSE("GPL");
 46 
 47 static dev_t ur_first_dev_maj_min;
 48 static struct class *vmur_class;
 49 static struct debug_info *vmur_dbf;
 50 
 51 /* We put the device's record length (for writes) in the driver_info field */
 52 static struct ccw_device_id ur_ids[] = {
 53         { CCWDEV_CU_DI(READER_PUNCH_DEVTYPE, 80) },
 54         { CCWDEV_CU_DI(PRINTER_DEVTYPE, 132) },
 55         { /* end of list */ }
 56 };
 57 
 58 MODULE_DEVICE_TABLE(ccw, ur_ids);
 59 
 60 static int ur_probe(struct ccw_device *cdev);
 61 static void ur_remove(struct ccw_device *cdev);
 62 static int ur_set_online(struct ccw_device *cdev);
 63 static int ur_set_offline(struct ccw_device *cdev);
 64 static int ur_pm_suspend(struct ccw_device *cdev);
 65 
 66 static struct ccw_driver ur_driver = {
 67         .driver = {
 68                 .name   = "vmur",
 69                 .owner  = THIS_MODULE,
 70         },
 71         .ids            = ur_ids,
 72         .probe          = ur_probe,
 73         .remove         = ur_remove,
 74         .set_online     = ur_set_online,
 75         .set_offline    = ur_set_offline,
 76         .freeze         = ur_pm_suspend,
 77         .int_class      = IRQIO_VMR,
 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_release 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         TRACE("ur_int_handler: intparm=0x%lx cstat=%02x dstat=%02x res=%u\n",
310               intparm, irb->scsw.cmd.cstat, irb->scsw.cmd.dstat,
311               irb->scsw.cmd.count);
312 
313         if (!intparm) {
314                 TRACE("ur_int_handler: unsolicited interrupt\n");
315                 return;
316         }
317         urd = dev_get_drvdata(&cdev->dev);
318         BUG_ON(!urd);
319         /* On special conditions irb is an error pointer */
320         if (IS_ERR(irb))
321                 urd->io_request_rc = PTR_ERR(irb);
322         else if (irb->scsw.cmd.dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END))
323                 urd->io_request_rc = 0;
324         else
325                 urd->io_request_rc = -EIO;
326 
327         complete(urd->io_done);
328 }
329 
330 /*
331  * reclen sysfs attribute - The record length to be used for write CCWs
332  */
333 static ssize_t ur_attr_reclen_show(struct device *dev,
334                                    struct device_attribute *attr, char *buf)
335 {
336         struct urdev *urd;
337         int rc;
338 
339         urd = urdev_get_from_cdev(to_ccwdev(dev));
340         if (!urd)
341                 return -ENODEV;
342         rc = sprintf(buf, "%zu\n", urd->reclen);
343         urdev_put(urd);
344         return rc;
345 }
346 
347 static DEVICE_ATTR(reclen, 0444, ur_attr_reclen_show, NULL);
348 
349 static int ur_create_attributes(struct device *dev)
350 {
351         return device_create_file(dev, &dev_attr_reclen);
352 }
353 
354 static void ur_remove_attributes(struct device *dev)
355 {
356         device_remove_file(dev, &dev_attr_reclen);
357 }
358 
359 /*
360  * diagnose code 0x210 - retrieve device information
361  * cc=0  normal completion, we have a real device
362  * cc=1  CP paging error
363  * cc=2  The virtual device exists, but is not associated with a real device
364  * cc=3  Invalid device address, or the virtual device does not exist
365  */
366 static int get_urd_class(struct urdev *urd)
367 {
368         static struct diag210 ur_diag210;
369         int cc;
370 
371         ur_diag210.vrdcdvno = urd->dev_id.devno;
372         ur_diag210.vrdclen = sizeof(struct diag210);
373 
374         cc = diag210(&ur_diag210);
375         switch (cc) {
376         case 0:
377                 return -EOPNOTSUPP;
378         case 2:
379                 return ur_diag210.vrdcvcla; /* virtual device class */
380         case 3:
381                 return -ENODEV;
382         default:
383                 return -EIO;
384         }
385 }
386 
387 /*
388  * Allocation and freeing of urfile structures
389  */
390 static struct urfile *urfile_alloc(struct urdev *urd)
391 {
392         struct urfile *urf;
393 
394         urf = kzalloc(sizeof(struct urfile), GFP_KERNEL);
395         if (!urf)
396                 return NULL;
397         urf->urd = urd;
398 
399         TRACE("urfile_alloc: urd=%p urf=%p rl=%zu\n", urd, urf,
400               urf->dev_reclen);
401 
402         return urf;
403 }
404 
405 static void urfile_free(struct urfile *urf)
406 {
407         TRACE("urfile_free: urf=%p urd=%p\n", urf, urf->urd);
408         kfree(urf);
409 }
410 
411 /*
412  * The fops implementation of the character device driver
413  */
414 static ssize_t do_write(struct urdev *urd, const char __user *udata,
415                         size_t count, size_t reclen, loff_t *ppos)
416 {
417         struct ccw1 *cpa;
418         int rc;
419 
420         cpa = alloc_chan_prog(udata, count / reclen, reclen);
421         if (IS_ERR(cpa))
422                 return PTR_ERR(cpa);
423 
424         rc = do_ur_io(urd, cpa);
425         if (rc)
426                 goto fail_kfree_cpa;
427 
428         if (urd->io_request_rc) {
429                 rc = urd->io_request_rc;
430                 goto fail_kfree_cpa;
431         }
432         *ppos += count;
433         rc = count;
434 
435 fail_kfree_cpa:
436         free_chan_prog(cpa);
437         return rc;
438 }
439 
440 static ssize_t ur_write(struct file *file, const char __user *udata,
441                         size_t count, loff_t *ppos)
442 {
443         struct urfile *urf = file->private_data;
444 
445         TRACE("ur_write: count=%zu\n", count);
446 
447         if (count == 0)
448                 return 0;
449 
450         if (count % urf->dev_reclen)
451                 return -EINVAL; /* count must be a multiple of reclen */
452 
453         if (count > urf->dev_reclen * MAX_RECS_PER_IO)
454                 count = urf->dev_reclen * MAX_RECS_PER_IO;
455 
456         return do_write(urf->urd, udata, count, urf->dev_reclen, ppos);
457 }
458 
459 /*
460  * diagnose code 0x14 subcode 0x0028 - position spool file to designated
461  *                                     record
462  * cc=0  normal completion
463  * cc=2  no file active on the virtual reader or device not ready
464  * cc=3  record specified is beyond EOF
465  */
466 static int diag_position_to_record(int devno, int record)
467 {
468         int cc;
469 
470         cc = diag14(record, devno, 0x28);
471         switch (cc) {
472         case 0:
473                 return 0;
474         case 2:
475                 return -ENOMEDIUM;
476         case 3:
477                 return -ENODATA; /* position beyond end of file */
478         default:
479                 return -EIO;
480         }
481 }
482 
483 /*
484  * diagnose code 0x14 subcode 0x0000 - read next spool file buffer
485  * cc=0  normal completion
486  * cc=1  EOF reached
487  * cc=2  no file active on the virtual reader, and no file eligible
488  * cc=3  file already active on the virtual reader or specified virtual
489  *       reader does not exist or is not a reader
490  */
491 static int diag_read_file(int devno, char *buf)
492 {
493         int cc;
494 
495         cc = diag14((unsigned long) buf, devno, 0x00);
496         switch (cc) {
497         case 0:
498                 return 0;
499         case 1:
500                 return -ENODATA;
501         case 2:
502                 return -ENOMEDIUM;
503         default:
504                 return -EIO;
505         }
506 }
507 
508 static ssize_t diag14_read(struct file *file, char __user *ubuf, size_t count,
509                            loff_t *offs)
510 {
511         size_t len, copied, res;
512         char *buf;
513         int rc;
514         u16 reclen;
515         struct urdev *urd;
516 
517         urd = ((struct urfile *) file->private_data)->urd;
518         reclen = ((struct urfile *) file->private_data)->file_reclen;
519 
520         rc = diag_position_to_record(urd->dev_id.devno, *offs / PAGE_SIZE + 1);
521         if (rc == -ENODATA)
522                 return 0;
523         if (rc)
524                 return rc;
525 
526         len = min((size_t) PAGE_SIZE, count);
527         buf = (char *) __get_free_page(GFP_KERNEL | GFP_DMA);
528         if (!buf)
529                 return -ENOMEM;
530 
531         copied = 0;
532         res = (size_t) (*offs % PAGE_SIZE);
533         do {
534                 rc = diag_read_file(urd->dev_id.devno, buf);
535                 if (rc == -ENODATA) {
536                         break;
537                 }
538                 if (rc)
539                         goto fail;
540                 if (reclen && (copied == 0) && (*offs < PAGE_SIZE))
541                         *((u16 *) &buf[FILE_RECLEN_OFFSET]) = reclen;
542                 len = min(count - copied, PAGE_SIZE - res);
543                 if (copy_to_user(ubuf + copied, buf + res, len)) {
544                         rc = -EFAULT;
545                         goto fail;
546                 }
547                 res = 0;
548                 copied += len;
549         } while (copied != count);
550 
551         *offs += copied;
552         rc = copied;
553 fail:
554         free_page((unsigned long) buf);
555         return rc;
556 }
557 
558 static ssize_t ur_read(struct file *file, char __user *ubuf, size_t count,
559                        loff_t *offs)
560 {
561         struct urdev *urd;
562         int rc;
563 
564         TRACE("ur_read: count=%zu ppos=%li\n", count, (unsigned long) *offs);
565 
566         if (count == 0)
567                 return 0;
568 
569         urd = ((struct urfile *) file->private_data)->urd;
570         rc = mutex_lock_interruptible(&urd->io_mutex);
571         if (rc)
572                 return rc;
573         rc = diag14_read(file, ubuf, count, offs);
574         mutex_unlock(&urd->io_mutex);
575         return rc;
576 }
577 
578 /*
579  * diagnose code 0x14 subcode 0x0fff - retrieve next file descriptor
580  * cc=0  normal completion
581  * cc=1  no files on reader queue or no subsequent file
582  * cc=2  spid specified is invalid
583  */
584 static int diag_read_next_file_info(struct file_control_block *buf, int spid)
585 {
586         int cc;
587 
588         cc = diag14((unsigned long) buf, spid, 0xfff);
589         switch (cc) {
590         case 0:
591                 return 0;
592         default:
593                 return -ENODATA;
594         }
595 }
596 
597 static int verify_uri_device(struct urdev *urd)
598 {
599         struct file_control_block *fcb;
600         char *buf;
601         int rc;
602 
603         fcb = kmalloc(sizeof(*fcb), GFP_KERNEL | GFP_DMA);
604         if (!fcb)
605                 return -ENOMEM;
606 
607         /* check for empty reader device (beginning of chain) */
608         rc = diag_read_next_file_info(fcb, 0);
609         if (rc)
610                 goto fail_free_fcb;
611 
612         /* if file is in hold status, we do not read it */
613         if (fcb->file_stat & (FLG_SYSTEM_HOLD | FLG_USER_HOLD)) {
614                 rc = -EPERM;
615                 goto fail_free_fcb;
616         }
617 
618         /* open file on virtual reader  */
619         buf = (char *) __get_free_page(GFP_KERNEL | GFP_DMA);
620         if (!buf) {
621                 rc = -ENOMEM;
622                 goto fail_free_fcb;
623         }
624         rc = diag_read_file(urd->dev_id.devno, buf);
625         if ((rc != 0) && (rc != -ENODATA)) /* EOF does not hurt */
626                 goto fail_free_buf;
627 
628         /* check if the file on top of the queue is open now */
629         rc = diag_read_next_file_info(fcb, 0);
630         if (rc)
631                 goto fail_free_buf;
632         if (!(fcb->file_stat & FLG_IN_USE)) {
633                 rc = -EMFILE;
634                 goto fail_free_buf;
635         }
636         rc = 0;
637 
638 fail_free_buf:
639         free_page((unsigned long) buf);
640 fail_free_fcb:
641         kfree(fcb);
642         return rc;
643 }
644 
645 static int verify_device(struct urdev *urd)
646 {
647         switch (urd->class) {
648         case DEV_CLASS_UR_O:
649                 return 0; /* no check needed here */
650         case DEV_CLASS_UR_I:
651                 return verify_uri_device(urd);
652         default:
653                 return -EOPNOTSUPP;
654         }
655 }
656 
657 static int get_uri_file_reclen(struct urdev *urd)
658 {
659         struct file_control_block *fcb;
660         int rc;
661 
662         fcb = kmalloc(sizeof(*fcb), GFP_KERNEL | GFP_DMA);
663         if (!fcb)
664                 return -ENOMEM;
665         rc = diag_read_next_file_info(fcb, 0);
666         if (rc)
667                 goto fail_free;
668         if (fcb->file_stat & FLG_CP_DUMP)
669                 rc = 0;
670         else
671                 rc = fcb->rec_len;
672 
673 fail_free:
674         kfree(fcb);
675         return rc;
676 }
677 
678 static int get_file_reclen(struct urdev *urd)
679 {
680         switch (urd->class) {
681         case DEV_CLASS_UR_O:
682                 return 0;
683         case DEV_CLASS_UR_I:
684                 return get_uri_file_reclen(urd);
685         default:
686                 return -EOPNOTSUPP;
687         }
688 }
689 
690 static int ur_open(struct inode *inode, struct file *file)
691 {
692         u16 devno;
693         struct urdev *urd;
694         struct urfile *urf;
695         unsigned short accmode;
696         int rc;
697 
698         accmode = file->f_flags & O_ACCMODE;
699 
700         if (accmode == O_RDWR)
701                 return -EACCES;
702         /*
703          * We treat the minor number as the devno of the ur device
704          * to find in the driver tree.
705          */
706         devno = MINOR(file_inode(file)->i_rdev);
707 
708         urd = urdev_get_from_devno(devno);
709         if (!urd) {
710                 rc = -ENXIO;
711                 goto out;
712         }
713 
714         spin_lock(&urd->open_lock);
715         while (urd->open_flag) {
716                 spin_unlock(&urd->open_lock);
717                 if (file->f_flags & O_NONBLOCK) {
718                         rc = -EBUSY;
719                         goto fail_put;
720                 }
721                 if (wait_event_interruptible(urd->wait, urd->open_flag == 0)) {
722                         rc = -ERESTARTSYS;
723                         goto fail_put;
724                 }
725                 spin_lock(&urd->open_lock);
726         }
727         urd->open_flag++;
728         spin_unlock(&urd->open_lock);
729 
730         TRACE("ur_open\n");
731 
732         if (((accmode == O_RDONLY) && (urd->class != DEV_CLASS_UR_I)) ||
733             ((accmode == O_WRONLY) && (urd->class != DEV_CLASS_UR_O))) {
734                 TRACE("ur_open: unsupported dev class (%d)\n", urd->class);
735                 rc = -EACCES;
736                 goto fail_unlock;
737         }
738 
739         rc = verify_device(urd);
740         if (rc)
741                 goto fail_unlock;
742 
743         urf = urfile_alloc(urd);
744         if (!urf) {
745                 rc = -ENOMEM;
746                 goto fail_unlock;
747         }
748 
749         urf->dev_reclen = urd->reclen;
750         rc = get_file_reclen(urd);
751         if (rc < 0)
752                 goto fail_urfile_free;
753         urf->file_reclen = rc;
754         file->private_data = urf;
755         return 0;
756 
757 fail_urfile_free:
758         urfile_free(urf);
759 fail_unlock:
760         spin_lock(&urd->open_lock);
761         urd->open_flag--;
762         spin_unlock(&urd->open_lock);
763 fail_put:
764         urdev_put(urd);
765 out:
766         return rc;
767 }
768 
769 static int ur_release(struct inode *inode, struct file *file)
770 {
771         struct urfile *urf = file->private_data;
772 
773         TRACE("ur_release\n");
774         spin_lock(&urf->urd->open_lock);
775         urf->urd->open_flag--;
776         spin_unlock(&urf->urd->open_lock);
777         wake_up_interruptible(&urf->urd->wait);
778         urdev_put(urf->urd);
779         urfile_free(urf);
780         return 0;
781 }
782 
783 static loff_t ur_llseek(struct file *file, loff_t offset, int whence)
784 {
785         loff_t newpos;
786 
787         if ((file->f_flags & O_ACCMODE) != O_RDONLY)
788                 return -ESPIPE; /* seek allowed only for reader */
789         if (offset % PAGE_SIZE)
790                 return -ESPIPE; /* only multiples of 4K allowed */
791         switch (whence) {
792         case 0: /* SEEK_SET */
793                 newpos = offset;
794                 break;
795         case 1: /* SEEK_CUR */
796                 newpos = file->f_pos + offset;
797                 break;
798         default:
799                 return -EINVAL;
800         }
801         file->f_pos = newpos;
802         return newpos;
803 }
804 
805 static const struct file_operations ur_fops = {
806         .owner   = THIS_MODULE,
807         .open    = ur_open,
808         .release = ur_release,
809         .read    = ur_read,
810         .write   = ur_write,
811         .llseek  = ur_llseek,
812 };
813 
814 /*
815  * ccw_device infrastructure:
816  *     ur_probe creates the struct urdev (with refcount = 1), the device
817  *     attributes, sets up the interrupt handler and validates the virtual
818  *     unit record device.
819  *     ur_remove removes the device attributes and drops the reference to
820  *     struct urdev.
821  *
822  *     ur_probe, ur_remove, ur_set_online and ur_set_offline are serialized
823  *     by the vmur_mutex lock.
824  *
825  *     urd->char_device is used as indication that the online function has
826  *     been completed successfully.
827  */
828 static int ur_probe(struct ccw_device *cdev)
829 {
830         struct urdev *urd;
831         int rc;
832 
833         TRACE("ur_probe: cdev=%p\n", cdev);
834 
835         mutex_lock(&vmur_mutex);
836         urd = urdev_alloc(cdev);
837         if (!urd) {
838                 rc = -ENOMEM;
839                 goto fail_unlock;
840         }
841 
842         rc = ur_create_attributes(&cdev->dev);
843         if (rc) {
844                 rc = -ENOMEM;
845                 goto fail_urdev_put;
846         }
847         cdev->handler = ur_int_handler;
848 
849         /* validate virtual unit record device */
850         urd->class = get_urd_class(urd);
851         if (urd->class < 0) {
852                 rc = urd->class;
853                 goto fail_remove_attr;
854         }
855         if ((urd->class != DEV_CLASS_UR_I) && (urd->class != DEV_CLASS_UR_O)) {
856                 rc = -EOPNOTSUPP;
857                 goto fail_remove_attr;
858         }
859         spin_lock_irq(get_ccwdev_lock(cdev));
860         dev_set_drvdata(&cdev->dev, urd);
861         spin_unlock_irq(get_ccwdev_lock(cdev));
862 
863         mutex_unlock(&vmur_mutex);
864         return 0;
865 
866 fail_remove_attr:
867         ur_remove_attributes(&cdev->dev);
868 fail_urdev_put:
869         urdev_put(urd);
870 fail_unlock:
871         mutex_unlock(&vmur_mutex);
872         return rc;
873 }
874 
875 static int ur_set_online(struct ccw_device *cdev)
876 {
877         struct urdev *urd;
878         int minor, major, rc;
879         char node_id[16];
880 
881         TRACE("ur_set_online: cdev=%p\n", cdev);
882 
883         mutex_lock(&vmur_mutex);
884         urd = urdev_get_from_cdev(cdev);
885         if (!urd) {
886                 /* ur_remove already deleted our urd */
887                 rc = -ENODEV;
888                 goto fail_unlock;
889         }
890 
891         if (urd->char_device) {
892                 /* Another ur_set_online was faster */
893                 rc = -EBUSY;
894                 goto fail_urdev_put;
895         }
896 
897         minor = urd->dev_id.devno;
898         major = MAJOR(ur_first_dev_maj_min);
899 
900         urd->char_device = cdev_alloc();
901         if (!urd->char_device) {
902                 rc = -ENOMEM;
903                 goto fail_urdev_put;
904         }
905 
906         urd->char_device->ops = &ur_fops;
907         urd->char_device->dev = MKDEV(major, minor);
908         urd->char_device->owner = ur_fops.owner;
909 
910         rc = cdev_add(urd->char_device, urd->char_device->dev, 1);
911         if (rc)
912                 goto fail_free_cdev;
913         if (urd->cdev->id.cu_type == READER_PUNCH_DEVTYPE) {
914                 if (urd->class == DEV_CLASS_UR_I)
915                         sprintf(node_id, "vmrdr-%s", dev_name(&cdev->dev));
916                 if (urd->class == DEV_CLASS_UR_O)
917                         sprintf(node_id, "vmpun-%s", dev_name(&cdev->dev));
918         } else if (urd->cdev->id.cu_type == PRINTER_DEVTYPE) {
919                 sprintf(node_id, "vmprt-%s", dev_name(&cdev->dev));
920         } else {
921                 rc = -EOPNOTSUPP;
922                 goto fail_free_cdev;
923         }
924 
925         urd->device = device_create(vmur_class, &cdev->dev,
926                                     urd->char_device->dev, NULL, "%s", node_id);
927         if (IS_ERR(urd->device)) {
928                 rc = PTR_ERR(urd->device);
929                 TRACE("ur_set_online: device_create rc=%d\n", rc);
930                 goto fail_free_cdev;
931         }
932         urdev_put(urd);
933         mutex_unlock(&vmur_mutex);
934         return 0;
935 
936 fail_free_cdev:
937         cdev_del(urd->char_device);
938         urd->char_device = NULL;
939 fail_urdev_put:
940         urdev_put(urd);
941 fail_unlock:
942         mutex_unlock(&vmur_mutex);
943         return rc;
944 }
945 
946 static int ur_set_offline_force(struct ccw_device *cdev, int force)
947 {
948         struct urdev *urd;
949         int rc;
950 
951         TRACE("ur_set_offline: cdev=%p\n", cdev);
952         urd = urdev_get_from_cdev(cdev);
953         if (!urd)
954                 /* ur_remove already deleted our urd */
955                 return -ENODEV;
956         if (!urd->char_device) {
957                 /* Another ur_set_offline was faster */
958                 rc = -EBUSY;
959                 goto fail_urdev_put;
960         }
961         if (!force && (atomic_read(&urd->ref_count) > 2)) {
962                 /* There is still a user of urd (e.g. ur_open) */
963                 TRACE("ur_set_offline: BUSY\n");
964                 rc = -EBUSY;
965                 goto fail_urdev_put;
966         }
967         device_destroy(vmur_class, urd->char_device->dev);
968         cdev_del(urd->char_device);
969         urd->char_device = NULL;
970         rc = 0;
971 
972 fail_urdev_put:
973         urdev_put(urd);
974         return rc;
975 }
976 
977 static int ur_set_offline(struct ccw_device *cdev)
978 {
979         int rc;
980 
981         mutex_lock(&vmur_mutex);
982         rc = ur_set_offline_force(cdev, 0);
983         mutex_unlock(&vmur_mutex);
984         return rc;
985 }
986 
987 static void ur_remove(struct ccw_device *cdev)
988 {
989         unsigned long flags;
990 
991         TRACE("ur_remove\n");
992 
993         mutex_lock(&vmur_mutex);
994 
995         if (cdev->online)
996                 ur_set_offline_force(cdev, 1);
997         ur_remove_attributes(&cdev->dev);
998 
999         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1000         urdev_put(dev_get_drvdata(&cdev->dev));
1001         dev_set_drvdata(&cdev->dev, NULL);
1002         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1003 
1004         mutex_unlock(&vmur_mutex);
1005 }
1006 
1007 /*
1008  * Module initialisation and cleanup
1009  */
1010 static int __init ur_init(void)
1011 {
1012         int rc;
1013         dev_t dev;
1014 
1015         if (!MACHINE_IS_VM) {
1016                 pr_err("The %s cannot be loaded without z/VM\n",
1017                        ur_banner);
1018                 return -ENODEV;
1019         }
1020 
1021         vmur_dbf = debug_register("vmur", 4, 1, 4 * sizeof(long));
1022         if (!vmur_dbf)
1023                 return -ENOMEM;
1024         rc = debug_register_view(vmur_dbf, &debug_sprintf_view);
1025         if (rc)
1026                 goto fail_free_dbf;
1027 
1028         debug_set_level(vmur_dbf, 6);
1029 
1030         vmur_class = class_create(THIS_MODULE, "vmur");
1031         if (IS_ERR(vmur_class)) {
1032                 rc = PTR_ERR(vmur_class);
1033                 goto fail_free_dbf;
1034         }
1035 
1036         rc = ccw_driver_register(&ur_driver);
1037         if (rc)
1038                 goto fail_class_destroy;
1039 
1040         rc = alloc_chrdev_region(&dev, 0, NUM_MINORS, "vmur");
1041         if (rc) {
1042                 pr_err("Kernel function alloc_chrdev_region failed with "
1043                        "error code %d\n", rc);
1044                 goto fail_unregister_driver;
1045         }
1046         ur_first_dev_maj_min = MKDEV(MAJOR(dev), 0);
1047 
1048         pr_info("%s loaded.\n", ur_banner);
1049         return 0;
1050 
1051 fail_unregister_driver:
1052         ccw_driver_unregister(&ur_driver);
1053 fail_class_destroy:
1054         class_destroy(vmur_class);
1055 fail_free_dbf:
1056         debug_unregister(vmur_dbf);
1057         return rc;
1058 }
1059 
1060 static void __exit ur_exit(void)
1061 {
1062         unregister_chrdev_region(ur_first_dev_maj_min, NUM_MINORS);
1063         ccw_driver_unregister(&ur_driver);
1064         class_destroy(vmur_class);
1065         debug_unregister(vmur_dbf);
1066         pr_info("%s unloaded.\n", ur_banner);
1067 }
1068 
1069 module_init(ur_init);
1070 module_exit(ur_exit);
1071 

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