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, 2007 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 #include <linux/cdev.h> 12 #include <linux/smp_lock.h> 13 14 #include <asm/uaccess.h> 15 #include <asm/cio.h> 16 #include <asm/ccwdev.h> 17 #include <asm/debug.h> 18 #include <asm/diag.h> 19 20 #include "vmur.h" 21 22 /* 23 * Driver overview 24 * 25 * Unit record device support is implemented as a character device driver. 26 * We can fit at least 16 bits into a device minor number and use the 27 * simple method of mapping a character device number with minor abcd 28 * to the unit record device with devno abcd. 29 * I/O to virtual unit record devices is handled as follows: 30 * Reads: Diagnose code 0x14 (input spool file manipulation) 31 * is used to read spool data page-wise. 32 * Writes: The CCW used is WRITE_CCW_CMD (0x01). The device's record length 33 * is available by reading sysfs attr reclen. Each write() to the device 34 * must specify an integral multiple (maximal 511) of reclen. 35 */ 36 37 static char ur_banner[] = "z/VM virtual unit record device driver"; 38 39 MODULE_AUTHOR("IBM Corporation"); 40 MODULE_DESCRIPTION("s390 z/VM virtual unit record device driver"); 41 MODULE_LICENSE("GPL"); 42 43 #define PRINTK_HEADER "vmur: " 44 45 static dev_t ur_first_dev_maj_min; 46 static struct class *vmur_class; 47 static struct debug_info *vmur_dbf; 48 49 /* We put the device's record length (for writes) in the driver_info field */ 50 static struct ccw_device_id ur_ids[] = { 51 { CCWDEV_CU_DI(READER_PUNCH_DEVTYPE, 80) }, 52 { CCWDEV_CU_DI(PRINTER_DEVTYPE, 132) }, 53 { /* end of list */ } 54 }; 55 56 MODULE_DEVICE_TABLE(ccw, ur_ids); 57 58 static int ur_probe(struct ccw_device *cdev); 59 static void ur_remove(struct ccw_device *cdev); 60 static int ur_set_online(struct ccw_device *cdev); 61 static int ur_set_offline(struct ccw_device *cdev); 62 63 static struct ccw_driver ur_driver = { 64 .name = "vmur", 65 .owner = THIS_MODULE, 66 .ids = ur_ids, 67 .probe = ur_probe, 68 .remove = ur_remove, 69 .set_online = ur_set_online, 70 .set_offline = ur_set_offline, 71 }; 72 73 static DEFINE_MUTEX(vmur_mutex); 74 75 /* 76 * Allocation, freeing, getting and putting of urdev structures 77 * 78 * Each ur device (urd) contains a reference to its corresponding ccw device 79 * (cdev) using the urd->cdev pointer. Each ccw device has a reference to the 80 * ur device using the cdev->dev.driver_data pointer. 81 * 82 * urd references: 83 * - ur_probe gets a urd reference, ur_remove drops the reference 84 * (cdev->dev.driver_data) 85 * - ur_open gets a urd reference, ur_relase drops the reference 86 * (urf->urd) 87 * 88 * cdev references: 89 * - urdev_alloc get a cdev reference (urd->cdev) 90 * - urdev_free drops the cdev reference (urd->cdev) 91 * 92 * Setting and clearing of cdev->dev.driver_data is protected by the ccwdev lock 93 */ 94 static struct urdev *urdev_alloc(struct ccw_device *cdev) 95 { 96 struct urdev *urd; 97 98 urd = kzalloc(sizeof(struct urdev), GFP_KERNEL); 99 if (!urd) 100 return NULL; 101 urd->reclen = cdev->id.driver_info; 102 ccw_device_get_id(cdev, &urd->dev_id); 103 mutex_init(&urd->io_mutex); 104 init_waitqueue_head(&urd->wait); 105 spin_lock_init(&urd->open_lock); 106 atomic_set(&urd->ref_count, 1); 107 urd->cdev = cdev; 108 get_device(&cdev->dev); 109 return urd; 110 } 111 112 static void urdev_free(struct urdev *urd) 113 { 114 TRACE("urdev_free: %p\n", urd); 115 if (urd->cdev) 116 put_device(&urd->cdev->dev); 117 kfree(urd); 118 } 119 120 static void urdev_get(struct urdev *urd) 121 { 122 atomic_inc(&urd->ref_count); 123 } 124 125 static struct urdev *urdev_get_from_cdev(struct ccw_device *cdev) 126 { 127 struct urdev *urd; 128 unsigned long flags; 129 130 spin_lock_irqsave(get_ccwdev_lock(cdev), flags); 131 urd = cdev->dev.driver_data; 132 if (urd) 133 urdev_get(urd); 134 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags); 135 return urd; 136 } 137 138 static struct urdev *urdev_get_from_devno(u16 devno) 139 { 140 char bus_id[16]; 141 struct ccw_device *cdev; 142 struct urdev *urd; 143 144 sprintf(bus_id, "0.0.%04x", devno); 145 cdev = get_ccwdev_by_busid(&ur_driver, bus_id); 146 if (!cdev) 147 return NULL; 148 urd = urdev_get_from_cdev(cdev); 149 put_device(&cdev->dev); 150 return urd; 151 } 152 153 static void urdev_put(struct urdev *urd) 154 { 155 if (atomic_dec_and_test(&urd->ref_count)) 156 urdev_free(urd); 157 } 158 159 /* 160 * Low-level functions to do I/O to a ur device. 161 * alloc_chan_prog 162 * free_chan_prog 163 * do_ur_io 164 * ur_int_handler 165 * 166 * alloc_chan_prog allocates and builds the channel program 167 * free_chan_prog frees memory of the channel program 168 * 169 * do_ur_io issues the channel program to the device and blocks waiting 170 * on a completion event it publishes at urd->io_done. The function 171 * serialises itself on the device's mutex so that only one I/O 172 * is issued at a time (and that I/O is synchronous). 173 * 174 * ur_int_handler catches the "I/O done" interrupt, writes the 175 * subchannel status word into the scsw member of the urdev structure 176 * and complete()s the io_done to wake the waiting do_ur_io. 177 * 178 * The caller of do_ur_io is responsible for kfree()ing the channel program 179 * address pointer that alloc_chan_prog returned. 180 */ 181 182 static void free_chan_prog(struct ccw1 *cpa) 183 { 184 struct ccw1 *ptr = cpa; 185 186 while (ptr->cda) { 187 kfree((void *)(addr_t) ptr->cda); 188 ptr++; 189 } 190 kfree(cpa); 191 } 192 193 /* 194 * alloc_chan_prog 195 * The channel program we use is write commands chained together 196 * with a final NOP CCW command-chained on (which ensures that CE and DE 197 * are presented together in a single interrupt instead of as separate 198 * interrupts unless an incorrect length indication kicks in first). The 199 * data length in each CCW is reclen. 200 */ 201 static struct ccw1 *alloc_chan_prog(const char __user *ubuf, int rec_count, 202 int reclen) 203 { 204 struct ccw1 *cpa; 205 void *kbuf; 206 int i; 207 208 TRACE("alloc_chan_prog(%p, %i, %i)\n", ubuf, rec_count, reclen); 209 210 /* 211 * We chain a NOP onto the writes to force CE+DE together. 212 * That means we allocate room for CCWs to cover count/reclen 213 * records plus a NOP. 214 */ 215 cpa = kzalloc((rec_count + 1) * sizeof(struct ccw1), 216 GFP_KERNEL | GFP_DMA); 217 if (!cpa) 218 return ERR_PTR(-ENOMEM); 219 220 for (i = 0; i < rec_count; i++) { 221 cpa[i].cmd_code = WRITE_CCW_CMD; 222 cpa[i].flags = CCW_FLAG_CC | CCW_FLAG_SLI; 223 cpa[i].count = reclen; 224 kbuf = kmalloc(reclen, GFP_KERNEL | GFP_DMA); 225 if (!kbuf) { 226 free_chan_prog(cpa); 227 return ERR_PTR(-ENOMEM); 228 } 229 cpa[i].cda = (u32)(addr_t) kbuf; 230 if (copy_from_user(kbuf, ubuf, reclen)) { 231 free_chan_prog(cpa); 232 return ERR_PTR(-EFAULT); 233 } 234 ubuf += reclen; 235 } 236 /* The following NOP CCW forces CE+DE to be presented together */ 237 cpa[i].cmd_code = CCW_CMD_NOOP; 238 return cpa; 239 } 240 241 static int do_ur_io(struct urdev *urd, struct ccw1 *cpa) 242 { 243 int rc; 244 struct ccw_device *cdev = urd->cdev; 245 DECLARE_COMPLETION_ONSTACK(event); 246 247 TRACE("do_ur_io: cpa=%p\n", cpa); 248 249 rc = mutex_lock_interruptible(&urd->io_mutex); 250 if (rc) 251 return rc; 252 253 urd->io_done = &event; 254 255 spin_lock_irq(get_ccwdev_lock(cdev)); 256 rc = ccw_device_start(cdev, cpa, 1, 0, 0); 257 spin_unlock_irq(get_ccwdev_lock(cdev)); 258 259 TRACE("do_ur_io: ccw_device_start returned %d\n", rc); 260 if (rc) 261 goto out; 262 263 wait_for_completion(&event); 264 TRACE("do_ur_io: I/O complete\n"); 265 rc = 0; 266 267 out: 268 mutex_unlock(&urd->io_mutex); 269 return rc; 270 } 271 272 /* 273 * ur interrupt handler, called from the ccw_device layer 274 */ 275 static void ur_int_handler(struct ccw_device *cdev, unsigned long intparm, 276 struct irb *irb) 277 { 278 struct urdev *urd; 279 280 TRACE("ur_int_handler: intparm=0x%lx cstat=%02x dstat=%02x res=%u\n", 281 intparm, irb->scsw.cmd.cstat, irb->scsw.cmd.dstat, 282 irb->scsw.cmd.count); 283 284 if (!intparm) { 285 TRACE("ur_int_handler: unsolicited interrupt\n"); 286 return; 287 } 288 urd = cdev->dev.driver_data; 289 BUG_ON(!urd); 290 /* On special conditions irb is an error pointer */ 291 if (IS_ERR(irb)) 292 urd->io_request_rc = PTR_ERR(irb); 293 else if (irb->scsw.cmd.dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END)) 294 urd->io_request_rc = 0; 295 else 296 urd->io_request_rc = -EIO; 297 298 complete(urd->io_done); 299 } 300 301 /* 302 * reclen sysfs attribute - The record length to be used for write CCWs 303 */ 304 static ssize_t ur_attr_reclen_show(struct device *dev, 305 struct device_attribute *attr, char *buf) 306 { 307 struct urdev *urd; 308 int rc; 309 310 urd = urdev_get_from_cdev(to_ccwdev(dev)); 311 if (!urd) 312 return -ENODEV; 313 rc = sprintf(buf, "%zu\n", urd->reclen); 314 urdev_put(urd); 315 return rc; 316 } 317 318 static DEVICE_ATTR(reclen, 0444, ur_attr_reclen_show, NULL); 319 320 static int ur_create_attributes(struct device *dev) 321 { 322 return device_create_file(dev, &dev_attr_reclen); 323 } 324 325 static void ur_remove_attributes(struct device *dev) 326 { 327 device_remove_file(dev, &dev_attr_reclen); 328 } 329 330 /* 331 * diagnose code 0x210 - retrieve device information 332 * cc=0 normal completion, we have a real device 333 * cc=1 CP paging error 334 * cc=2 The virtual device exists, but is not associated with a real device 335 * cc=3 Invalid device address, or the virtual device does not exist 336 */ 337 static int get_urd_class(struct urdev *urd) 338 { 339 static struct diag210 ur_diag210; 340 int cc; 341 342 ur_diag210.vrdcdvno = urd->dev_id.devno; 343 ur_diag210.vrdclen = sizeof(struct diag210); 344 345 cc = diag210(&ur_diag210); 346 switch (cc) { 347 case 0: 348 return -EOPNOTSUPP; 349 case 2: 350 return ur_diag210.vrdcvcla; /* virtual device class */ 351 case 3: 352 return -ENODEV; 353 default: 354 return -EIO; 355 } 356 } 357 358 /* 359 * Allocation and freeing of urfile structures 360 */ 361 static struct urfile *urfile_alloc(struct urdev *urd) 362 { 363 struct urfile *urf; 364 365 urf = kzalloc(sizeof(struct urfile), GFP_KERNEL); 366 if (!urf) 367 return NULL; 368 urf->urd = urd; 369 370 TRACE("urfile_alloc: urd=%p urf=%p rl=%zu\n", urd, urf, 371 urf->dev_reclen); 372 373 return urf; 374 } 375 376 static void urfile_free(struct urfile *urf) 377 { 378 TRACE("urfile_free: urf=%p urd=%p\n", urf, urf->urd); 379 kfree(urf); 380 } 381 382 /* 383 * The fops implementation of the character device driver 384 */ 385 static ssize_t do_write(struct urdev *urd, const char __user *udata, 386 size_t count, size_t reclen, loff_t *ppos) 387 { 388 struct ccw1 *cpa; 389 int rc; 390 391 cpa = alloc_chan_prog(udata, count / reclen, reclen); 392 if (IS_ERR(cpa)) 393 return PTR_ERR(cpa); 394 395 rc = do_ur_io(urd, cpa); 396 if (rc) 397 goto fail_kfree_cpa; 398 399 if (urd->io_request_rc) { 400 rc = urd->io_request_rc; 401 goto fail_kfree_cpa; 402 } 403 *ppos += count; 404 rc = count; 405 406 fail_kfree_cpa: 407 free_chan_prog(cpa); 408 return rc; 409 } 410 411 static ssize_t ur_write(struct file *file, const char __user *udata, 412 size_t count, loff_t *ppos) 413 { 414 struct urfile *urf = file->private_data; 415 416 TRACE("ur_write: count=%zu\n", count); 417 418 if (count == 0) 419 return 0; 420 421 if (count % urf->dev_reclen) 422 return -EINVAL; /* count must be a multiple of reclen */ 423 424 if (count > urf->dev_reclen * MAX_RECS_PER_IO) 425 count = urf->dev_reclen * MAX_RECS_PER_IO; 426 427 return do_write(urf->urd, udata, count, urf->dev_reclen, ppos); 428 } 429 430 /* 431 * diagnose code 0x14 subcode 0x0028 - position spool file to designated 432 * record 433 * cc=0 normal completion 434 * cc=2 no file active on the virtual reader or device not ready 435 * cc=3 record specified is beyond EOF 436 */ 437 static int diag_position_to_record(int devno, int record) 438 { 439 int cc; 440 441 cc = diag14(record, devno, 0x28); 442 switch (cc) { 443 case 0: 444 return 0; 445 case 2: 446 return -ENOMEDIUM; 447 case 3: 448 return -ENODATA; /* position beyond end of file */ 449 default: 450 return -EIO; 451 } 452 } 453 454 /* 455 * diagnose code 0x14 subcode 0x0000 - read next spool file buffer 456 * cc=0 normal completion 457 * cc=1 EOF reached 458 * cc=2 no file active on the virtual reader, and no file eligible 459 * cc=3 file already active on the virtual reader or specified virtual 460 * reader does not exist or is not a reader 461 */ 462 static int diag_read_file(int devno, char *buf) 463 { 464 int cc; 465 466 cc = diag14((unsigned long) buf, devno, 0x00); 467 switch (cc) { 468 case 0: 469 return 0; 470 case 1: 471 return -ENODATA; 472 case 2: 473 return -ENOMEDIUM; 474 default: 475 return -EIO; 476 } 477 } 478 479 static ssize_t diag14_read(struct file *file, char __user *ubuf, size_t count, 480 loff_t *offs) 481 { 482 size_t len, copied, res; 483 char *buf; 484 int rc; 485 u16 reclen; 486 struct urdev *urd; 487 488 urd = ((struct urfile *) file->private_data)->urd; 489 reclen = ((struct urfile *) file->private_data)->file_reclen; 490 491 rc = diag_position_to_record(urd->dev_id.devno, *offs / PAGE_SIZE + 1); 492 if (rc == -ENODATA) 493 return 0; 494 if (rc) 495 return rc; 496 497 len = min((size_t) PAGE_SIZE, count); 498 buf = (char *) __get_free_page(GFP_KERNEL | GFP_DMA); 499 if (!buf) 500 return -ENOMEM; 501 502 copied = 0; 503 res = (size_t) (*offs % PAGE_SIZE); 504 do { 505 rc = diag_read_file(urd->dev_id.devno, buf); 506 if (rc == -ENODATA) { 507 break; 508 } 509 if (rc) 510 goto fail; 511 if (reclen && (copied == 0) && (*offs < PAGE_SIZE)) 512 *((u16 *) &buf[FILE_RECLEN_OFFSET]) = reclen; 513 len = min(count - copied, PAGE_SIZE - res); 514 if (copy_to_user(ubuf + copied, buf + res, len)) { 515 rc = -EFAULT; 516 goto fail; 517 } 518 res = 0; 519 copied += len; 520 } while (copied != count); 521 522 *offs += copied; 523 rc = copied; 524 fail: 525 free_page((unsigned long) buf); 526 return rc; 527 } 528 529 static ssize_t ur_read(struct file *file, char __user *ubuf, size_t count, 530 loff_t *offs) 531 { 532 struct urdev *urd; 533 int rc; 534 535 TRACE("ur_read: count=%zu ppos=%li\n", count, (unsigned long) *offs); 536 537 if (count == 0) 538 return 0; 539 540 urd = ((struct urfile *) file->private_data)->urd; 541 rc = mutex_lock_interruptible(&urd->io_mutex); 542 if (rc) 543 return rc; 544 rc = diag14_read(file, ubuf, count, offs); 545 mutex_unlock(&urd->io_mutex); 546 return rc; 547 } 548 549 /* 550 * diagnose code 0x14 subcode 0x0fff - retrieve next file descriptor 551 * cc=0 normal completion 552 * cc=1 no files on reader queue or no subsequent file 553 * cc=2 spid specified is invalid 554 */ 555 static int diag_read_next_file_info(struct file_control_block *buf, int spid) 556 { 557 int cc; 558 559 cc = diag14((unsigned long) buf, spid, 0xfff); 560 switch (cc) { 561 case 0: 562 return 0; 563 default: 564 return -ENODATA; 565 } 566 } 567 568 static int verify_uri_device(struct urdev *urd) 569 { 570 struct file_control_block *fcb; 571 char *buf; 572 int rc; 573 574 fcb = kmalloc(sizeof(*fcb), GFP_KERNEL | GFP_DMA); 575 if (!fcb) 576 return -ENOMEM; 577 578 /* check for empty reader device (beginning of chain) */ 579 rc = diag_read_next_file_info(fcb, 0); 580 if (rc) 581 goto fail_free_fcb; 582 583 /* if file is in hold status, we do not read it */ 584 if (fcb->file_stat & (FLG_SYSTEM_HOLD | FLG_USER_HOLD)) { 585 rc = -EPERM; 586 goto fail_free_fcb; 587 } 588 589 /* open file on virtual reader */ 590 buf = (char *) __get_free_page(GFP_KERNEL | GFP_DMA); 591 if (!buf) { 592 rc = -ENOMEM; 593 goto fail_free_fcb; 594 } 595 rc = diag_read_file(urd->dev_id.devno, buf); 596 if ((rc != 0) && (rc != -ENODATA)) /* EOF does not hurt */ 597 goto fail_free_buf; 598 599 /* check if the file on top of the queue is open now */ 600 rc = diag_read_next_file_info(fcb, 0); 601 if (rc) 602 goto fail_free_buf; 603 if (!(fcb->file_stat & FLG_IN_USE)) { 604 rc = -EMFILE; 605 goto fail_free_buf; 606 } 607 rc = 0; 608 609 fail_free_buf: 610 free_page((unsigned long) buf); 611 fail_free_fcb: 612 kfree(fcb); 613 return rc; 614 } 615 616 static int verify_device(struct urdev *urd) 617 { 618 switch (urd->class) { 619 case DEV_CLASS_UR_O: 620 return 0; /* no check needed here */ 621 case DEV_CLASS_UR_I: 622 return verify_uri_device(urd); 623 default: 624 return -EOPNOTSUPP; 625 } 626 } 627 628 static int get_uri_file_reclen(struct urdev *urd) 629 { 630 struct file_control_block *fcb; 631 int rc; 632 633 fcb = kmalloc(sizeof(*fcb), GFP_KERNEL | GFP_DMA); 634 if (!fcb) 635 return -ENOMEM; 636 rc = diag_read_next_file_info(fcb, 0); 637 if (rc) 638 goto fail_free; 639 if (fcb->file_stat & FLG_CP_DUMP) 640 rc = 0; 641 else 642 rc = fcb->rec_len; 643 644 fail_free: 645 kfree(fcb); 646 return rc; 647 } 648 649 static int get_file_reclen(struct urdev *urd) 650 { 651 switch (urd->class) { 652 case DEV_CLASS_UR_O: 653 return 0; 654 case DEV_CLASS_UR_I: 655 return get_uri_file_reclen(urd); 656 default: 657 return -EOPNOTSUPP; 658 } 659 } 660 661 static int ur_open(struct inode *inode, struct file *file) 662 { 663 u16 devno; 664 struct urdev *urd; 665 struct urfile *urf; 666 unsigned short accmode; 667 int rc; 668 669 accmode = file->f_flags & O_ACCMODE; 670 671 if (accmode == O_RDWR) 672 return -EACCES; 673 lock_kernel(); 674 /* 675 * We treat the minor number as the devno of the ur device 676 * to find in the driver tree. 677 */ 678 devno = MINOR(file->f_dentry->d_inode->i_rdev); 679 680 urd = urdev_get_from_devno(devno); 681 if (!urd) { 682 rc = -ENXIO; 683 goto out; 684 } 685 686 spin_lock(&urd->open_lock); 687 while (urd->open_flag) { 688 spin_unlock(&urd->open_lock); 689 if (file->f_flags & O_NONBLOCK) { 690 rc = -EBUSY; 691 goto fail_put; 692 } 693 if (wait_event_interruptible(urd->wait, urd->open_flag == 0)) { 694 rc = -ERESTARTSYS; 695 goto fail_put; 696 } 697 spin_lock(&urd->open_lock); 698 } 699 urd->open_flag++; 700 spin_unlock(&urd->open_lock); 701 702 TRACE("ur_open\n"); 703 704 if (((accmode == O_RDONLY) && (urd->class != DEV_CLASS_UR_I)) || 705 ((accmode == O_WRONLY) && (urd->class != DEV_CLASS_UR_O))) { 706 TRACE("ur_open: unsupported dev class (%d)\n", urd->class); 707 rc = -EACCES; 708 goto fail_unlock; 709 } 710 711 rc = verify_device(urd); 712 if (rc) 713 goto fail_unlock; 714 715 urf = urfile_alloc(urd); 716 if (!urf) { 717 rc = -ENOMEM; 718 goto fail_unlock; 719 } 720 721 urf->dev_reclen = urd->reclen; 722 rc = get_file_reclen(urd); 723 if (rc < 0) 724 goto fail_urfile_free; 725 urf->file_reclen = rc; 726 file->private_data = urf; 727 unlock_kernel(); 728 return 0; 729 730 fail_urfile_free: 731 urfile_free(urf); 732 fail_unlock: 733 spin_lock(&urd->open_lock); 734 urd->open_flag--; 735 spin_unlock(&urd->open_lock); 736 fail_put: 737 urdev_put(urd); 738 out: 739 unlock_kernel(); 740 return rc; 741 } 742 743 static int ur_release(struct inode *inode, struct file *file) 744 { 745 struct urfile *urf = file->private_data; 746 747 TRACE("ur_release\n"); 748 spin_lock(&urf->urd->open_lock); 749 urf->urd->open_flag--; 750 spin_unlock(&urf->urd->open_lock); 751 wake_up_interruptible(&urf->urd->wait); 752 urdev_put(urf->urd); 753 urfile_free(urf); 754 return 0; 755 } 756 757 static loff_t ur_llseek(struct file *file, loff_t offset, int whence) 758 { 759 loff_t newpos; 760 761 if ((file->f_flags & O_ACCMODE) != O_RDONLY) 762 return -ESPIPE; /* seek allowed only for reader */ 763 if (offset % PAGE_SIZE) 764 return -ESPIPE; /* only multiples of 4K allowed */ 765 switch (whence) { 766 case 0: /* SEEK_SET */ 767 newpos = offset; 768 break; 769 case 1: /* SEEK_CUR */ 770 newpos = file->f_pos + offset; 771 break; 772 default: 773 return -EINVAL; 774 } 775 file->f_pos = newpos; 776 return newpos; 777 } 778 779 static const struct file_operations ur_fops = { 780 .owner = THIS_MODULE, 781 .open = ur_open, 782 .release = ur_release, 783 .read = ur_read, 784 .write = ur_write, 785 .llseek = ur_llseek, 786 }; 787 788 /* 789 * ccw_device infrastructure: 790 * ur_probe creates the struct urdev (with refcount = 1), the device 791 * attributes, sets up the interrupt handler and validates the virtual 792 * unit record device. 793 * ur_remove removes the device attributes and drops the reference to 794 * struct urdev. 795 * 796 * ur_probe, ur_remove, ur_set_online and ur_set_offline are serialized 797 * by the vmur_mutex lock. 798 * 799 * urd->char_device is used as indication that the online function has 800 * been completed successfully. 801 */ 802 static int ur_probe(struct ccw_device *cdev) 803 { 804 struct urdev *urd; 805 int rc; 806 807 TRACE("ur_probe: cdev=%p\n", cdev); 808 809 mutex_lock(&vmur_mutex); 810 urd = urdev_alloc(cdev); 811 if (!urd) { 812 rc = -ENOMEM; 813 goto fail_unlock; 814 } 815 816 rc = ur_create_attributes(&cdev->dev); 817 if (rc) { 818 rc = -ENOMEM; 819 goto fail_urdev_put; 820 } 821 cdev->handler = ur_int_handler; 822 823 /* validate virtual unit record device */ 824 urd->class = get_urd_class(urd); 825 if (urd->class < 0) { 826 rc = urd->class; 827 goto fail_remove_attr; 828 } 829 if ((urd->class != DEV_CLASS_UR_I) && (urd->class != DEV_CLASS_UR_O)) { 830 rc = -EOPNOTSUPP; 831 goto fail_remove_attr; 832 } 833 spin_lock_irq(get_ccwdev_lock(cdev)); 834 cdev->dev.driver_data = urd; 835 spin_unlock_irq(get_ccwdev_lock(cdev)); 836 837 mutex_unlock(&vmur_mutex); 838 return 0; 839 840 fail_remove_attr: 841 ur_remove_attributes(&cdev->dev); 842 fail_urdev_put: 843 urdev_put(urd); 844 fail_unlock: 845 mutex_unlock(&vmur_mutex); 846 return rc; 847 } 848 849 static int ur_set_online(struct ccw_device *cdev) 850 { 851 struct urdev *urd; 852 int minor, major, rc; 853 char node_id[16]; 854 855 TRACE("ur_set_online: cdev=%p\n", cdev); 856 857 mutex_lock(&vmur_mutex); 858 urd = urdev_get_from_cdev(cdev); 859 if (!urd) { 860 /* ur_remove already deleted our urd */ 861 rc = -ENODEV; 862 goto fail_unlock; 863 } 864 865 if (urd->char_device) { 866 /* Another ur_set_online was faster */ 867 rc = -EBUSY; 868 goto fail_urdev_put; 869 } 870 871 minor = urd->dev_id.devno; 872 major = MAJOR(ur_first_dev_maj_min); 873 874 urd->char_device = cdev_alloc(); 875 if (!urd->char_device) { 876 rc = -ENOMEM; 877 goto fail_urdev_put; 878 } 879 880 cdev_init(urd->char_device, &ur_fops); 881 urd->char_device->dev = MKDEV(major, minor); 882 urd->char_device->owner = ur_fops.owner; 883 884 rc = cdev_add(urd->char_device, urd->char_device->dev, 1); 885 if (rc) 886 goto fail_free_cdev; 887 if (urd->cdev->id.cu_type == READER_PUNCH_DEVTYPE) { 888 if (urd->class == DEV_CLASS_UR_I) 889 sprintf(node_id, "vmrdr-%s", cdev->dev.bus_id); 890 if (urd->class == DEV_CLASS_UR_O) 891 sprintf(node_id, "vmpun-%s", cdev->dev.bus_id); 892 } else if (urd->cdev->id.cu_type == PRINTER_DEVTYPE) { 893 sprintf(node_id, "vmprt-%s", cdev->dev.bus_id); 894 } else { 895 rc = -EOPNOTSUPP; 896 goto fail_free_cdev; 897 } 898 899 urd->device = device_create_drvdata(vmur_class, NULL, 900 urd->char_device->dev, NULL, 901 "%s", node_id); 902 if (IS_ERR(urd->device)) { 903 rc = PTR_ERR(urd->device); 904 TRACE("ur_set_online: device_create rc=%d\n", rc); 905 goto fail_free_cdev; 906 } 907 urdev_put(urd); 908 mutex_unlock(&vmur_mutex); 909 return 0; 910 911 fail_free_cdev: 912 cdev_del(urd->char_device); 913 urd->char_device = NULL; 914 fail_urdev_put: 915 urdev_put(urd); 916 fail_unlock: 917 mutex_unlock(&vmur_mutex); 918 return rc; 919 } 920 921 static int ur_set_offline_force(struct ccw_device *cdev, int force) 922 { 923 struct urdev *urd; 924 int rc; 925 926 TRACE("ur_set_offline: cdev=%p\n", cdev); 927 urd = urdev_get_from_cdev(cdev); 928 if (!urd) 929 /* ur_remove already deleted our urd */ 930 return -ENODEV; 931 if (!urd->char_device) { 932 /* Another ur_set_offline was faster */ 933 rc = -EBUSY; 934 goto fail_urdev_put; 935 } 936 if (!force && (atomic_read(&urd->ref_count) > 2)) { 937 /* There is still a user of urd (e.g. ur_open) */ 938 TRACE("ur_set_offline: BUSY\n"); 939 rc = -EBUSY; 940 goto fail_urdev_put; 941 } 942 device_destroy(vmur_class, urd->char_device->dev); 943 cdev_del(urd->char_device); 944 urd->char_device = NULL; 945 rc = 0; 946 947 fail_urdev_put: 948 urdev_put(urd); 949 return rc; 950 } 951 952 static int ur_set_offline(struct ccw_device *cdev) 953 { 954 int rc; 955 956 mutex_lock(&vmur_mutex); 957 rc = ur_set_offline_force(cdev, 0); 958 mutex_unlock(&vmur_mutex); 959 return rc; 960 } 961 962 static void ur_remove(struct ccw_device *cdev) 963 { 964 unsigned long flags; 965 966 TRACE("ur_remove\n"); 967 968 mutex_lock(&vmur_mutex); 969 970 if (cdev->online) 971 ur_set_offline_force(cdev, 1); 972 ur_remove_attributes(&cdev->dev); 973 974 spin_lock_irqsave(get_ccwdev_lock(cdev), flags); 975 urdev_put(cdev->dev.driver_data); 976 cdev->dev.driver_data = NULL; 977 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags); 978 979 mutex_unlock(&vmur_mutex); 980 } 981 982 /* 983 * Module initialisation and cleanup 984 */ 985 static int __init ur_init(void) 986 { 987 int rc; 988 dev_t dev; 989 990 if (!MACHINE_IS_VM) { 991 PRINT_ERR("%s is only available under z/VM.\n", ur_banner); 992 return -ENODEV; 993 } 994 995 vmur_dbf = debug_register("vmur", 4, 1, 4 * sizeof(long)); 996 if (!vmur_dbf) 997 return -ENOMEM; 998 rc = debug_register_view(vmur_dbf, &debug_sprintf_view); 999 if (rc) 1000 goto fail_free_dbf; 1001 1002 debug_set_level(vmur_dbf, 6); 1003 1004 rc = ccw_driver_register(&ur_driver); 1005 if (rc) 1006 goto fail_free_dbf; 1007 1008 rc = alloc_chrdev_region(&dev, 0, NUM_MINORS, "vmur"); 1009 if (rc) { 1010 PRINT_ERR("alloc_chrdev_region failed: err = %d\n", rc); 1011 goto fail_unregister_driver; 1012 } 1013 ur_first_dev_maj_min = MKDEV(MAJOR(dev), 0); 1014 1015 vmur_class = class_create(THIS_MODULE, "vmur"); 1016 if (IS_ERR(vmur_class)) { 1017 rc = PTR_ERR(vmur_class); 1018 goto fail_unregister_region; 1019 } 1020 PRINT_INFO("%s loaded.\n", ur_banner); 1021 return 0; 1022 1023 fail_unregister_region: 1024 unregister_chrdev_region(ur_first_dev_maj_min, NUM_MINORS); 1025 fail_unregister_driver: 1026 ccw_driver_unregister(&ur_driver); 1027 fail_free_dbf: 1028 debug_unregister(vmur_dbf); 1029 return rc; 1030 } 1031 1032 static void __exit ur_exit(void) 1033 { 1034 class_destroy(vmur_class); 1035 unregister_chrdev_region(ur_first_dev_maj_min, NUM_MINORS); 1036 ccw_driver_unregister(&ur_driver); 1037 debug_unregister(vmur_dbf); 1038 PRINT_INFO("%s unloaded.\n", ur_banner); 1039 } 1040 1041 module_init(ur_init); 1042 module_exit(ur_exit); 1043