1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com> 4 * Based on.......: linux/drivers/s390/block/mdisk.c 5 * ...............: by Hartmunt Penner <hpenner@de.ibm.com> 6 * Bugreports.to..: <Linux390@de.ibm.com> 7 * Copyright IBM Corp. 1999, 2000 8 * 9 */ 10 11 #define KMSG_COMPONENT "dasd" 12 13 #include <linux/kernel_stat.h> 14 #include <linux/stddef.h> 15 #include <linux/kernel.h> 16 #include <linux/slab.h> 17 #include <linux/hdreg.h> 18 #include <linux/bio.h> 19 #include <linux/module.h> 20 #include <linux/init.h> 21 #include <linux/jiffies.h> 22 23 #include <asm/dasd.h> 24 #include <asm/debug.h> 25 #include <asm/diag.h> 26 #include <asm/ebcdic.h> 27 #include <asm/io.h> 28 #include <asm/irq.h> 29 #include <asm/vtoc.h> 30 31 #include "dasd_int.h" 32 #include "dasd_diag.h" 33 34 #define PRINTK_HEADER "dasd(diag):" 35 36 MODULE_LICENSE("GPL"); 37 38 /* The maximum number of blocks per request (max_blocks) is dependent on the 39 * amount of storage that is available in the static I/O buffer for each 40 * device. Currently each device gets 2 pages. We want to fit two requests 41 * into the available memory so that we can immediately start the next if one 42 * finishes. */ 43 #define DIAG_MAX_BLOCKS (((2 * PAGE_SIZE - sizeof(struct dasd_ccw_req) - \ 44 sizeof(struct dasd_diag_req)) / \ 45 sizeof(struct dasd_diag_bio)) / 2) 46 #define DIAG_MAX_RETRIES 32 47 #define DIAG_TIMEOUT 50 48 49 static struct dasd_discipline dasd_diag_discipline; 50 51 struct dasd_diag_private { 52 struct dasd_diag_characteristics rdc_data; 53 struct dasd_diag_rw_io iob; 54 struct dasd_diag_init_io iib; 55 blocknum_t pt_block; 56 struct ccw_dev_id dev_id; 57 }; 58 59 struct dasd_diag_req { 60 unsigned int block_count; 61 struct dasd_diag_bio bio[0]; 62 }; 63 64 static const u8 DASD_DIAG_CMS1[] = { 0xc3, 0xd4, 0xe2, 0xf1 };/* EBCDIC CMS1 */ 65 66 /* Perform DIAG250 call with block I/O parameter list iob (input and output) 67 * and function code cmd. 68 * In case of an exception return 3. Otherwise return result of bitwise OR of 69 * resulting condition code and DIAG return code. */ 70 static inline int __dia250(void *iob, int cmd) 71 { 72 register unsigned long reg2 asm ("2") = (unsigned long) iob; 73 typedef union { 74 struct dasd_diag_init_io init_io; 75 struct dasd_diag_rw_io rw_io; 76 } addr_type; 77 int rc; 78 79 rc = 3; 80 asm volatile( 81 " diag 2,%2,0x250\n" 82 "0: ipm %0\n" 83 " srl %0,28\n" 84 " or %0,3\n" 85 "1:\n" 86 EX_TABLE(0b,1b) 87 : "+d" (rc), "=m" (*(addr_type *) iob) 88 : "d" (cmd), "d" (reg2), "m" (*(addr_type *) iob) 89 : "3", "cc"); 90 return rc; 91 } 92 93 static inline int dia250(void *iob, int cmd) 94 { 95 diag_stat_inc(DIAG_STAT_X250); 96 return __dia250(iob, cmd); 97 } 98 99 /* Initialize block I/O to DIAG device using the specified blocksize and 100 * block offset. On success, return zero and set end_block to contain the 101 * number of blocks on the device minus the specified offset. Return non-zero 102 * otherwise. */ 103 static inline int 104 mdsk_init_io(struct dasd_device *device, unsigned int blocksize, 105 blocknum_t offset, blocknum_t *end_block) 106 { 107 struct dasd_diag_private *private = device->private; 108 struct dasd_diag_init_io *iib = &private->iib; 109 int rc; 110 111 memset(iib, 0, sizeof (struct dasd_diag_init_io)); 112 113 iib->dev_nr = private->dev_id.devno; 114 iib->block_size = blocksize; 115 iib->offset = offset; 116 iib->flaga = DASD_DIAG_FLAGA_DEFAULT; 117 118 rc = dia250(iib, INIT_BIO); 119 120 if ((rc & 3) == 0 && end_block) 121 *end_block = iib->end_block; 122 123 return rc; 124 } 125 126 /* Remove block I/O environment for device. Return zero on success, non-zero 127 * otherwise. */ 128 static inline int 129 mdsk_term_io(struct dasd_device * device) 130 { 131 struct dasd_diag_private *private = device->private; 132 struct dasd_diag_init_io *iib = &private->iib; 133 int rc; 134 135 memset(iib, 0, sizeof (struct dasd_diag_init_io)); 136 iib->dev_nr = private->dev_id.devno; 137 rc = dia250(iib, TERM_BIO); 138 return rc; 139 } 140 141 /* Error recovery for failed DIAG requests - try to reestablish the DIAG 142 * environment. */ 143 static void 144 dasd_diag_erp(struct dasd_device *device) 145 { 146 int rc; 147 148 mdsk_term_io(device); 149 rc = mdsk_init_io(device, device->block->bp_block, 0, NULL); 150 if (rc == 4) { 151 if (!(test_and_set_bit(DASD_FLAG_DEVICE_RO, &device->flags))) 152 pr_warn("%s: The access mode of a DIAG device changed to read-only\n", 153 dev_name(&device->cdev->dev)); 154 rc = 0; 155 } 156 if (rc) 157 pr_warn("%s: DIAG ERP failed with rc=%d\n", 158 dev_name(&device->cdev->dev), rc); 159 } 160 161 /* Start a given request at the device. Return zero on success, non-zero 162 * otherwise. */ 163 static int 164 dasd_start_diag(struct dasd_ccw_req * cqr) 165 { 166 struct dasd_device *device; 167 struct dasd_diag_private *private; 168 struct dasd_diag_req *dreq; 169 int rc; 170 171 device = cqr->startdev; 172 if (cqr->retries < 0) { 173 DBF_DEV_EVENT(DBF_ERR, device, "DIAG start_IO: request %p " 174 "- no retry left)", cqr); 175 cqr->status = DASD_CQR_ERROR; 176 return -EIO; 177 } 178 private = device->private; 179 dreq = cqr->data; 180 181 private->iob.dev_nr = private->dev_id.devno; 182 private->iob.key = 0; 183 private->iob.flags = DASD_DIAG_RWFLAG_ASYNC; 184 private->iob.block_count = dreq->block_count; 185 private->iob.interrupt_params = (addr_t) cqr; 186 private->iob.bio_list = dreq->bio; 187 private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT; 188 189 cqr->startclk = get_tod_clock(); 190 cqr->starttime = jiffies; 191 cqr->retries--; 192 193 rc = dia250(&private->iob, RW_BIO); 194 switch (rc) { 195 case 0: /* Synchronous I/O finished successfully */ 196 cqr->stopclk = get_tod_clock(); 197 cqr->status = DASD_CQR_SUCCESS; 198 /* Indicate to calling function that only a dasd_schedule_bh() 199 and no timer is needed */ 200 rc = -EACCES; 201 break; 202 case 8: /* Asynchronous I/O was started */ 203 cqr->status = DASD_CQR_IN_IO; 204 rc = 0; 205 break; 206 default: /* Error condition */ 207 cqr->status = DASD_CQR_QUEUED; 208 DBF_DEV_EVENT(DBF_WARNING, device, "dia250 returned rc=%d", rc); 209 dasd_diag_erp(device); 210 rc = -EIO; 211 break; 212 } 213 cqr->intrc = rc; 214 return rc; 215 } 216 217 /* Terminate given request at the device. */ 218 static int 219 dasd_diag_term_IO(struct dasd_ccw_req * cqr) 220 { 221 struct dasd_device *device; 222 223 device = cqr->startdev; 224 mdsk_term_io(device); 225 mdsk_init_io(device, device->block->bp_block, 0, NULL); 226 cqr->status = DASD_CQR_CLEAR_PENDING; 227 cqr->stopclk = get_tod_clock(); 228 dasd_schedule_device_bh(device); 229 return 0; 230 } 231 232 /* Handle external interruption. */ 233 static void dasd_ext_handler(struct ext_code ext_code, 234 unsigned int param32, unsigned long param64) 235 { 236 struct dasd_ccw_req *cqr, *next; 237 struct dasd_device *device; 238 unsigned long expires; 239 unsigned long flags; 240 addr_t ip; 241 int rc; 242 243 switch (ext_code.subcode >> 8) { 244 case DASD_DIAG_CODE_31BIT: 245 ip = (addr_t) param32; 246 break; 247 case DASD_DIAG_CODE_64BIT: 248 ip = (addr_t) param64; 249 break; 250 default: 251 return; 252 } 253 inc_irq_stat(IRQEXT_DSD); 254 if (!ip) { /* no intparm: unsolicited interrupt */ 255 DBF_EVENT(DBF_NOTICE, "%s", "caught unsolicited " 256 "interrupt"); 257 return; 258 } 259 cqr = (struct dasd_ccw_req *) ip; 260 device = (struct dasd_device *) cqr->startdev; 261 if (strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) { 262 DBF_DEV_EVENT(DBF_WARNING, device, 263 " magic number of dasd_ccw_req 0x%08X doesn't" 264 " match discipline 0x%08X", 265 cqr->magic, *(int *) (&device->discipline->name)); 266 return; 267 } 268 269 /* get irq lock to modify request queue */ 270 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); 271 272 /* Check for a pending clear operation */ 273 if (cqr->status == DASD_CQR_CLEAR_PENDING) { 274 cqr->status = DASD_CQR_CLEARED; 275 dasd_device_clear_timer(device); 276 dasd_schedule_device_bh(device); 277 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); 278 return; 279 } 280 281 cqr->stopclk = get_tod_clock(); 282 283 expires = 0; 284 if ((ext_code.subcode & 0xff) == 0) { 285 cqr->status = DASD_CQR_SUCCESS; 286 /* Start first request on queue if possible -> fast_io. */ 287 if (!list_empty(&device->ccw_queue)) { 288 next = list_entry(device->ccw_queue.next, 289 struct dasd_ccw_req, devlist); 290 if (next->status == DASD_CQR_QUEUED) { 291 rc = dasd_start_diag(next); 292 if (rc == 0) 293 expires = next->expires; 294 } 295 } 296 } else { 297 cqr->status = DASD_CQR_QUEUED; 298 DBF_DEV_EVENT(DBF_DEBUG, device, "interrupt status for " 299 "request %p was %d (%d retries left)", cqr, 300 ext_code.subcode & 0xff, cqr->retries); 301 dasd_diag_erp(device); 302 } 303 304 if (expires != 0) 305 dasd_device_set_timer(device, expires); 306 else 307 dasd_device_clear_timer(device); 308 dasd_schedule_device_bh(device); 309 310 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); 311 } 312 313 /* Check whether device can be controlled by DIAG discipline. Return zero on 314 * success, non-zero otherwise. */ 315 static int 316 dasd_diag_check_device(struct dasd_device *device) 317 { 318 struct dasd_diag_private *private = device->private; 319 struct dasd_diag_characteristics *rdc_data; 320 struct vtoc_cms_label *label; 321 struct dasd_block *block; 322 struct dasd_diag_bio bio; 323 unsigned int sb, bsize; 324 blocknum_t end_block; 325 int rc; 326 327 if (private == NULL) { 328 private = kzalloc(sizeof(*private), GFP_KERNEL); 329 if (private == NULL) { 330 DBF_DEV_EVENT(DBF_WARNING, device, "%s", 331 "Allocating memory for private DASD data " 332 "failed\n"); 333 return -ENOMEM; 334 } 335 ccw_device_get_id(device->cdev, &private->dev_id); 336 device->private = private; 337 } 338 block = dasd_alloc_block(); 339 if (IS_ERR(block)) { 340 DBF_DEV_EVENT(DBF_WARNING, device, "%s", 341 "could not allocate dasd block structure"); 342 device->private = NULL; 343 kfree(private); 344 return PTR_ERR(block); 345 } 346 device->block = block; 347 block->base = device; 348 349 /* Read Device Characteristics */ 350 rdc_data = &private->rdc_data; 351 rdc_data->dev_nr = private->dev_id.devno; 352 rdc_data->rdc_len = sizeof (struct dasd_diag_characteristics); 353 354 rc = diag210((struct diag210 *) rdc_data); 355 if (rc) { 356 DBF_DEV_EVENT(DBF_WARNING, device, "failed to retrieve device " 357 "information (rc=%d)", rc); 358 rc = -EOPNOTSUPP; 359 goto out; 360 } 361 362 device->default_expires = DIAG_TIMEOUT; 363 device->default_retries = DIAG_MAX_RETRIES; 364 365 /* Figure out position of label block */ 366 switch (private->rdc_data.vdev_class) { 367 case DEV_CLASS_FBA: 368 private->pt_block = 1; 369 break; 370 case DEV_CLASS_ECKD: 371 private->pt_block = 2; 372 break; 373 default: 374 pr_warn("%s: Device type %d is not supported in DIAG mode\n", 375 dev_name(&device->cdev->dev), 376 private->rdc_data.vdev_class); 377 rc = -EOPNOTSUPP; 378 goto out; 379 } 380 381 DBF_DEV_EVENT(DBF_INFO, device, 382 "%04X: %04X on real %04X/%02X", 383 rdc_data->dev_nr, 384 rdc_data->vdev_type, 385 rdc_data->rdev_type, rdc_data->rdev_model); 386 387 /* terminate all outstanding operations */ 388 mdsk_term_io(device); 389 390 /* figure out blocksize of device */ 391 label = (struct vtoc_cms_label *) get_zeroed_page(GFP_KERNEL); 392 if (label == NULL) { 393 DBF_DEV_EVENT(DBF_WARNING, device, "%s", 394 "No memory to allocate initialization request"); 395 rc = -ENOMEM; 396 goto out; 397 } 398 rc = 0; 399 end_block = 0; 400 /* try all sizes - needed for ECKD devices */ 401 for (bsize = 512; bsize <= PAGE_SIZE; bsize <<= 1) { 402 mdsk_init_io(device, bsize, 0, &end_block); 403 memset(&bio, 0, sizeof (struct dasd_diag_bio)); 404 bio.type = MDSK_READ_REQ; 405 bio.block_number = private->pt_block + 1; 406 bio.buffer = label; 407 memset(&private->iob, 0, sizeof (struct dasd_diag_rw_io)); 408 private->iob.dev_nr = rdc_data->dev_nr; 409 private->iob.key = 0; 410 private->iob.flags = 0; /* do synchronous io */ 411 private->iob.block_count = 1; 412 private->iob.interrupt_params = 0; 413 private->iob.bio_list = &bio; 414 private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT; 415 rc = dia250(&private->iob, RW_BIO); 416 if (rc == 3) { 417 pr_warn("%s: A 64-bit DIAG call failed\n", 418 dev_name(&device->cdev->dev)); 419 rc = -EOPNOTSUPP; 420 goto out_label; 421 } 422 mdsk_term_io(device); 423 if (rc == 0) 424 break; 425 } 426 if (bsize > PAGE_SIZE) { 427 pr_warn("%s: Accessing the DASD failed because of an incorrect format (rc=%d)\n", 428 dev_name(&device->cdev->dev), rc); 429 rc = -EIO; 430 goto out_label; 431 } 432 /* check for label block */ 433 if (memcmp(label->label_id, DASD_DIAG_CMS1, 434 sizeof(DASD_DIAG_CMS1)) == 0) { 435 /* get formatted blocksize from label block */ 436 bsize = (unsigned int) label->block_size; 437 block->blocks = (unsigned long) label->block_count; 438 } else 439 block->blocks = end_block; 440 block->bp_block = bsize; 441 block->s2b_shift = 0; /* bits to shift 512 to get a block */ 442 for (sb = 512; sb < bsize; sb = sb << 1) 443 block->s2b_shift++; 444 rc = mdsk_init_io(device, block->bp_block, 0, NULL); 445 if (rc && (rc != 4)) { 446 pr_warn("%s: DIAG initialization failed with rc=%d\n", 447 dev_name(&device->cdev->dev), rc); 448 rc = -EIO; 449 } else { 450 if (rc == 4) 451 set_bit(DASD_FLAG_DEVICE_RO, &device->flags); 452 pr_info("%s: New DASD with %ld byte/block, total size %ld " 453 "KB%s\n", dev_name(&device->cdev->dev), 454 (unsigned long) block->bp_block, 455 (unsigned long) (block->blocks << 456 block->s2b_shift) >> 1, 457 (rc == 4) ? ", read-only device" : ""); 458 rc = 0; 459 } 460 out_label: 461 free_page((long) label); 462 out: 463 if (rc) { 464 device->block = NULL; 465 dasd_free_block(block); 466 device->private = NULL; 467 kfree(private); 468 } 469 return rc; 470 } 471 472 /* Fill in virtual disk geometry for device. Return zero on success, non-zero 473 * otherwise. */ 474 static int 475 dasd_diag_fill_geometry(struct dasd_block *block, struct hd_geometry *geo) 476 { 477 if (dasd_check_blocksize(block->bp_block) != 0) 478 return -EINVAL; 479 geo->cylinders = (block->blocks << block->s2b_shift) >> 10; 480 geo->heads = 16; 481 geo->sectors = 128 >> block->s2b_shift; 482 return 0; 483 } 484 485 static dasd_erp_fn_t 486 dasd_diag_erp_action(struct dasd_ccw_req * cqr) 487 { 488 return dasd_default_erp_action; 489 } 490 491 static dasd_erp_fn_t 492 dasd_diag_erp_postaction(struct dasd_ccw_req * cqr) 493 { 494 return dasd_default_erp_postaction; 495 } 496 497 /* Create DASD request from block device request. Return pointer to new 498 * request on success, ERR_PTR otherwise. */ 499 static struct dasd_ccw_req *dasd_diag_build_cp(struct dasd_device *memdev, 500 struct dasd_block *block, 501 struct request *req) 502 { 503 struct dasd_ccw_req *cqr; 504 struct dasd_diag_req *dreq; 505 struct dasd_diag_bio *dbio; 506 struct req_iterator iter; 507 struct bio_vec bv; 508 char *dst; 509 unsigned int count, datasize; 510 sector_t recid, first_rec, last_rec; 511 unsigned int blksize, off; 512 unsigned char rw_cmd; 513 514 if (rq_data_dir(req) == READ) 515 rw_cmd = MDSK_READ_REQ; 516 else if (rq_data_dir(req) == WRITE) 517 rw_cmd = MDSK_WRITE_REQ; 518 else 519 return ERR_PTR(-EINVAL); 520 blksize = block->bp_block; 521 /* Calculate record id of first and last block. */ 522 first_rec = blk_rq_pos(req) >> block->s2b_shift; 523 last_rec = 524 (blk_rq_pos(req) + blk_rq_sectors(req) - 1) >> block->s2b_shift; 525 /* Check struct bio and count the number of blocks for the request. */ 526 count = 0; 527 rq_for_each_segment(bv, req, iter) { 528 if (bv.bv_len & (blksize - 1)) 529 /* Fba can only do full blocks. */ 530 return ERR_PTR(-EINVAL); 531 count += bv.bv_len >> (block->s2b_shift + 9); 532 } 533 /* Paranoia. */ 534 if (count != last_rec - first_rec + 1) 535 return ERR_PTR(-EINVAL); 536 /* Build the request */ 537 datasize = sizeof(struct dasd_diag_req) + 538 count*sizeof(struct dasd_diag_bio); 539 cqr = dasd_smalloc_request(DASD_DIAG_MAGIC, 0, datasize, memdev); 540 if (IS_ERR(cqr)) 541 return cqr; 542 543 dreq = (struct dasd_diag_req *) cqr->data; 544 dreq->block_count = count; 545 dbio = dreq->bio; 546 recid = first_rec; 547 rq_for_each_segment(bv, req, iter) { 548 dst = page_address(bv.bv_page) + bv.bv_offset; 549 for (off = 0; off < bv.bv_len; off += blksize) { 550 memset(dbio, 0, sizeof (struct dasd_diag_bio)); 551 dbio->type = rw_cmd; 552 dbio->block_number = recid + 1; 553 dbio->buffer = dst; 554 dbio++; 555 dst += blksize; 556 recid++; 557 } 558 } 559 cqr->retries = memdev->default_retries; 560 cqr->buildclk = get_tod_clock(); 561 if (blk_noretry_request(req) || 562 block->base->features & DASD_FEATURE_FAILFAST) 563 set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags); 564 cqr->startdev = memdev; 565 cqr->memdev = memdev; 566 cqr->block = block; 567 cqr->expires = memdev->default_expires * HZ; 568 cqr->status = DASD_CQR_FILLED; 569 return cqr; 570 } 571 572 /* Release DASD request. Return non-zero if request was successful, zero 573 * otherwise. */ 574 static int 575 dasd_diag_free_cp(struct dasd_ccw_req *cqr, struct request *req) 576 { 577 int status; 578 579 status = cqr->status == DASD_CQR_DONE; 580 dasd_sfree_request(cqr, cqr->memdev); 581 return status; 582 } 583 584 static void dasd_diag_handle_terminated_request(struct dasd_ccw_req *cqr) 585 { 586 if (cqr->retries < 0) 587 cqr->status = DASD_CQR_FAILED; 588 else 589 cqr->status = DASD_CQR_FILLED; 590 }; 591 592 /* Fill in IOCTL data for device. */ 593 static int 594 dasd_diag_fill_info(struct dasd_device * device, 595 struct dasd_information2_t * info) 596 { 597 struct dasd_diag_private *private = device->private; 598 599 info->label_block = (unsigned int) private->pt_block; 600 info->FBA_layout = 1; 601 info->format = DASD_FORMAT_LDL; 602 info->characteristics_size = sizeof(private->rdc_data); 603 memcpy(info->characteristics, &private->rdc_data, 604 sizeof(private->rdc_data)); 605 info->confdata_size = 0; 606 return 0; 607 } 608 609 static void 610 dasd_diag_dump_sense(struct dasd_device *device, struct dasd_ccw_req * req, 611 struct irb *stat) 612 { 613 DBF_DEV_EVENT(DBF_WARNING, device, "%s", 614 "dump sense not available for DIAG data"); 615 } 616 617 static struct dasd_discipline dasd_diag_discipline = { 618 .owner = THIS_MODULE, 619 .name = "DIAG", 620 .ebcname = "DIAG", 621 .max_blocks = DIAG_MAX_BLOCKS, 622 .check_device = dasd_diag_check_device, 623 .verify_path = dasd_generic_verify_path, 624 .fill_geometry = dasd_diag_fill_geometry, 625 .start_IO = dasd_start_diag, 626 .term_IO = dasd_diag_term_IO, 627 .handle_terminated_request = dasd_diag_handle_terminated_request, 628 .erp_action = dasd_diag_erp_action, 629 .erp_postaction = dasd_diag_erp_postaction, 630 .build_cp = dasd_diag_build_cp, 631 .free_cp = dasd_diag_free_cp, 632 .dump_sense = dasd_diag_dump_sense, 633 .fill_info = dasd_diag_fill_info, 634 }; 635 636 static int __init 637 dasd_diag_init(void) 638 { 639 if (!MACHINE_IS_VM) { 640 pr_info("Discipline %s cannot be used without z/VM\n", 641 dasd_diag_discipline.name); 642 return -ENODEV; 643 } 644 ASCEBC(dasd_diag_discipline.ebcname, 4); 645 646 irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL); 647 register_external_irq(EXT_IRQ_CP_SERVICE, dasd_ext_handler); 648 dasd_diag_discipline_pointer = &dasd_diag_discipline; 649 return 0; 650 } 651 652 static void __exit 653 dasd_diag_cleanup(void) 654 { 655 unregister_external_irq(EXT_IRQ_CP_SERVICE, dasd_ext_handler); 656 irq_subclass_unregister(IRQ_SUBCLASS_SERVICE_SIGNAL); 657 dasd_diag_discipline_pointer = NULL; 658 } 659 660 module_init(dasd_diag_init); 661 module_exit(dasd_diag_cleanup); 662