1 /* 2 * File...........: linux/drivers/s390/block/dasd_diag.c 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 * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000 8 * 9 */ 10 11 #define KMSG_COMPONENT "dasd" 12 13 #include <linux/stddef.h> 14 #include <linux/kernel.h> 15 #include <linux/slab.h> 16 #include <linux/hdreg.h> 17 #include <linux/bio.h> 18 #include <linux/module.h> 19 #include <linux/init.h> 20 #include <linux/jiffies.h> 21 22 #include <asm/dasd.h> 23 #include <asm/debug.h> 24 #include <asm/ebcdic.h> 25 #include <asm/io.h> 26 #include <asm/s390_ext.h> 27 #include <asm/vtoc.h> 28 #include <asm/diag.h> 29 30 #include "dasd_int.h" 31 #include "dasd_diag.h" 32 33 #define PRINTK_HEADER "dasd(diag):" 34 35 MODULE_LICENSE("GPL"); 36 37 /* The maximum number of blocks per request (max_blocks) is dependent on the 38 * amount of storage that is available in the static I/O buffer for each 39 * device. Currently each device gets 2 pages. We want to fit two requests 40 * into the available memory so that we can immediately start the next if one 41 * finishes. */ 42 #define DIAG_MAX_BLOCKS (((2 * PAGE_SIZE - sizeof(struct dasd_ccw_req) - \ 43 sizeof(struct dasd_diag_req)) / \ 44 sizeof(struct dasd_diag_bio)) / 2) 45 #define DIAG_MAX_RETRIES 32 46 #define DIAG_TIMEOUT 50 * HZ 47 48 static struct dasd_discipline dasd_diag_discipline; 49 50 struct dasd_diag_private { 51 struct dasd_diag_characteristics rdc_data; 52 struct dasd_diag_rw_io iob; 53 struct dasd_diag_init_io iib; 54 blocknum_t pt_block; 55 struct ccw_dev_id dev_id; 56 }; 57 58 struct dasd_diag_req { 59 unsigned int block_count; 60 struct dasd_diag_bio bio[0]; 61 }; 62 63 static const u8 DASD_DIAG_CMS1[] = { 0xc3, 0xd4, 0xe2, 0xf1 };/* EBCDIC CMS1 */ 64 65 /* Perform DIAG250 call with block I/O parameter list iob (input and output) 66 * and function code cmd. 67 * In case of an exception return 3. Otherwise return result of bitwise OR of 68 * resulting condition code and DIAG return code. */ 69 static inline int dia250(void *iob, int cmd) 70 { 71 register unsigned long reg2 asm ("2") = (unsigned long) iob; 72 typedef union { 73 struct dasd_diag_init_io init_io; 74 struct dasd_diag_rw_io rw_io; 75 } addr_type; 76 int rc; 77 78 rc = 3; 79 asm volatile( 80 " diag 2,%2,0x250\n" 81 "0: ipm %0\n" 82 " srl %0,28\n" 83 " or %0,3\n" 84 "1:\n" 85 EX_TABLE(0b,1b) 86 : "+d" (rc), "=m" (*(addr_type *) iob) 87 : "d" (cmd), "d" (reg2), "m" (*(addr_type *) iob) 88 : "3", "cc"); 89 return rc; 90 } 91 92 /* Initialize block I/O to DIAG device using the specified blocksize and 93 * block offset. On success, return zero and set end_block to contain the 94 * number of blocks on the device minus the specified offset. Return non-zero 95 * otherwise. */ 96 static inline int 97 mdsk_init_io(struct dasd_device *device, unsigned int blocksize, 98 blocknum_t offset, blocknum_t *end_block) 99 { 100 struct dasd_diag_private *private; 101 struct dasd_diag_init_io *iib; 102 int rc; 103 104 private = (struct dasd_diag_private *) device->private; 105 iib = &private->iib; 106 memset(iib, 0, sizeof (struct dasd_diag_init_io)); 107 108 iib->dev_nr = private->dev_id.devno; 109 iib->block_size = blocksize; 110 iib->offset = offset; 111 iib->flaga = DASD_DIAG_FLAGA_DEFAULT; 112 113 rc = dia250(iib, INIT_BIO); 114 115 if ((rc & 3) == 0 && end_block) 116 *end_block = iib->end_block; 117 118 return rc; 119 } 120 121 /* Remove block I/O environment for device. Return zero on success, non-zero 122 * otherwise. */ 123 static inline int 124 mdsk_term_io(struct dasd_device * device) 125 { 126 struct dasd_diag_private *private; 127 struct dasd_diag_init_io *iib; 128 int rc; 129 130 private = (struct dasd_diag_private *) device->private; 131 iib = &private->iib; 132 memset(iib, 0, sizeof (struct dasd_diag_init_io)); 133 iib->dev_nr = private->dev_id.devno; 134 rc = dia250(iib, TERM_BIO); 135 return rc; 136 } 137 138 /* Error recovery for failed DIAG requests - try to reestablish the DIAG 139 * environment. */ 140 static void 141 dasd_diag_erp(struct dasd_device *device) 142 { 143 int rc; 144 145 mdsk_term_io(device); 146 rc = mdsk_init_io(device, device->block->bp_block, 0, NULL); 147 if (rc == 4) { 148 if (!(device->features & DASD_FEATURE_READONLY)) { 149 pr_warning("%s: The access mode of a DIAG device " 150 "changed to read-only\n", 151 dev_name(&device->cdev->dev)); 152 device->features |= DASD_FEATURE_READONLY; 153 } 154 rc = 0; 155 } 156 if (rc) 157 pr_warning("%s: DIAG ERP failed with " 158 "rc=%d\n", 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 = (struct dasd_diag_private *) device->private; 179 dreq = (struct dasd_diag_req *) 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_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_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_clock(); 228 dasd_schedule_device_bh(device); 229 return 0; 230 } 231 232 /* Handle external interruption. */ 233 static void 234 dasd_ext_handler(__u16 code) 235 { 236 struct dasd_ccw_req *cqr, *next; 237 struct dasd_device *device; 238 unsigned long long expires; 239 unsigned long flags; 240 u8 int_code, status; 241 addr_t ip; 242 int rc; 243 244 int_code = *((u8 *) DASD_DIAG_LC_INT_CODE); 245 status = *((u8 *) DASD_DIAG_LC_INT_STATUS); 246 switch (int_code) { 247 case DASD_DIAG_CODE_31BIT: 248 ip = (addr_t) *((u32 *) DASD_DIAG_LC_INT_PARM_31BIT); 249 break; 250 case DASD_DIAG_CODE_64BIT: 251 ip = (addr_t) *((u64 *) DASD_DIAG_LC_INT_PARM_64BIT); 252 break; 253 default: 254 return; 255 } 256 if (!ip) { /* no intparm: unsolicited interrupt */ 257 DBF_EVENT(DBF_NOTICE, "%s", "caught unsolicited " 258 "interrupt"); 259 return; 260 } 261 cqr = (struct dasd_ccw_req *) ip; 262 device = (struct dasd_device *) cqr->startdev; 263 if (strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) { 264 DBF_DEV_EVENT(DBF_WARNING, device, 265 " magic number of dasd_ccw_req 0x%08X doesn't" 266 " match discipline 0x%08X", 267 cqr->magic, *(int *) (&device->discipline->name)); 268 return; 269 } 270 271 /* get irq lock to modify request queue */ 272 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); 273 274 /* Check for a pending clear operation */ 275 if (cqr->status == DASD_CQR_CLEAR_PENDING) { 276 cqr->status = DASD_CQR_CLEARED; 277 dasd_device_clear_timer(device); 278 dasd_schedule_device_bh(device); 279 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); 280 return; 281 } 282 283 cqr->stopclk = get_clock(); 284 285 expires = 0; 286 if (status == 0) { 287 cqr->status = DASD_CQR_SUCCESS; 288 /* Start first request on queue if possible -> fast_io. */ 289 if (!list_empty(&device->ccw_queue)) { 290 next = list_entry(device->ccw_queue.next, 291 struct dasd_ccw_req, devlist); 292 if (next->status == DASD_CQR_QUEUED) { 293 rc = dasd_start_diag(next); 294 if (rc == 0) 295 expires = next->expires; 296 } 297 } 298 } else { 299 cqr->status = DASD_CQR_QUEUED; 300 DBF_DEV_EVENT(DBF_DEBUG, device, "interrupt status for " 301 "request %p was %d (%d retries left)", cqr, status, 302 cqr->retries); 303 dasd_diag_erp(device); 304 } 305 306 if (expires != 0) 307 dasd_device_set_timer(device, expires); 308 else 309 dasd_device_clear_timer(device); 310 dasd_schedule_device_bh(device); 311 312 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); 313 } 314 315 /* Check whether device can be controlled by DIAG discipline. Return zero on 316 * success, non-zero otherwise. */ 317 static int 318 dasd_diag_check_device(struct dasd_device *device) 319 { 320 struct dasd_block *block; 321 struct dasd_diag_private *private; 322 struct dasd_diag_characteristics *rdc_data; 323 struct dasd_diag_bio bio; 324 struct vtoc_cms_label *label; 325 blocknum_t end_block; 326 unsigned int sb, bsize; 327 int rc; 328 329 private = (struct dasd_diag_private *) device->private; 330 if (private == NULL) { 331 private = kzalloc(sizeof(struct dasd_diag_private),GFP_KERNEL); 332 if (private == NULL) { 333 DBF_DEV_EVENT(DBF_WARNING, device, "%s", 334 "Allocating memory for private DASD data " 335 "failed\n"); 336 return -ENOMEM; 337 } 338 ccw_device_get_id(device->cdev, &private->dev_id); 339 device->private = (void *) private; 340 } 341 block = dasd_alloc_block(); 342 if (IS_ERR(block)) { 343 DBF_DEV_EVENT(DBF_WARNING, device, "%s", 344 "could not allocate dasd block structure"); 345 device->private = NULL; 346 kfree(private); 347 return PTR_ERR(block); 348 } 349 device->block = block; 350 block->base = device; 351 352 /* Read Device Characteristics */ 353 rdc_data = (void *) &(private->rdc_data); 354 rdc_data->dev_nr = private->dev_id.devno; 355 rdc_data->rdc_len = sizeof (struct dasd_diag_characteristics); 356 357 rc = diag210((struct diag210 *) rdc_data); 358 if (rc) { 359 DBF_DEV_EVENT(DBF_WARNING, device, "failed to retrieve device " 360 "information (rc=%d)", rc); 361 rc = -EOPNOTSUPP; 362 goto out; 363 } 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_warning("%s: Device type %d is not supported " 375 "in DIAG mode\n", 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_warning("%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_warning("%s: Accessing the DASD failed because of an " 428 "incorrect format (rc=%d)\n", 429 dev_name(&device->cdev->dev), rc); 430 rc = -EIO; 431 goto out_label; 432 } 433 /* check for label block */ 434 if (memcmp(label->label_id, DASD_DIAG_CMS1, 435 sizeof(DASD_DIAG_CMS1)) == 0) { 436 /* get formatted blocksize from label block */ 437 bsize = (unsigned int) label->block_size; 438 block->blocks = (unsigned long) label->block_count; 439 } else 440 block->blocks = end_block; 441 block->bp_block = bsize; 442 block->s2b_shift = 0; /* bits to shift 512 to get a block */ 443 for (sb = 512; sb < bsize; sb = sb << 1) 444 block->s2b_shift++; 445 rc = mdsk_init_io(device, block->bp_block, 0, NULL); 446 if (rc && (rc != 4)) { 447 pr_warning("%s: DIAG initialization failed with rc=%d\n", 448 dev_name(&device->cdev->dev), rc); 449 rc = -EIO; 450 } else { 451 if (rc == 4) 452 device->features |= DASD_FEATURE_READONLY; 453 pr_info("%s: New DASD with %ld byte/block, total size %ld " 454 "KB%s\n", dev_name(&device->cdev->dev), 455 (unsigned long) block->bp_block, 456 (unsigned long) (block->blocks << 457 block->s2b_shift) >> 1, 458 (rc == 4) ? ", read-only device" : ""); 459 rc = 0; 460 } 461 out_label: 462 free_page((long) label); 463 out: 464 if (rc) { 465 device->block = NULL; 466 dasd_free_block(block); 467 device->private = NULL; 468 kfree(private); 469 } 470 return rc; 471 } 472 473 /* Fill in virtual disk geometry for device. Return zero on success, non-zero 474 * otherwise. */ 475 static int 476 dasd_diag_fill_geometry(struct dasd_block *block, struct hd_geometry *geo) 477 { 478 if (dasd_check_blocksize(block->bp_block) != 0) 479 return -EINVAL; 480 geo->cylinders = (block->blocks << block->s2b_shift) >> 10; 481 geo->heads = 16; 482 geo->sectors = 128 >> block->s2b_shift; 483 return 0; 484 } 485 486 static dasd_erp_fn_t 487 dasd_diag_erp_action(struct dasd_ccw_req * cqr) 488 { 489 return dasd_default_erp_action; 490 } 491 492 static dasd_erp_fn_t 493 dasd_diag_erp_postaction(struct dasd_ccw_req * cqr) 494 { 495 return dasd_default_erp_postaction; 496 } 497 498 /* Create DASD request from block device request. Return pointer to new 499 * request on success, ERR_PTR otherwise. */ 500 static struct dasd_ccw_req *dasd_diag_build_cp(struct dasd_device *memdev, 501 struct dasd_block *block, 502 struct request *req) 503 { 504 struct dasd_ccw_req *cqr; 505 struct dasd_diag_req *dreq; 506 struct dasd_diag_bio *dbio; 507 struct req_iterator iter; 508 struct bio_vec *bv; 509 char *dst; 510 unsigned int count, datasize; 511 sector_t recid, first_rec, last_rec; 512 unsigned int blksize, off; 513 unsigned char rw_cmd; 514 515 if (rq_data_dir(req) == READ) 516 rw_cmd = MDSK_READ_REQ; 517 else if (rq_data_dir(req) == WRITE) 518 rw_cmd = MDSK_WRITE_REQ; 519 else 520 return ERR_PTR(-EINVAL); 521 blksize = block->bp_block; 522 /* Calculate record id of first and last block. */ 523 first_rec = blk_rq_pos(req) >> block->s2b_shift; 524 last_rec = 525 (blk_rq_pos(req) + blk_rq_sectors(req) - 1) >> block->s2b_shift; 526 /* Check struct bio and count the number of blocks for the request. */ 527 count = 0; 528 rq_for_each_segment(bv, req, iter) { 529 if (bv->bv_len & (blksize - 1)) 530 /* Fba can only do full blocks. */ 531 return ERR_PTR(-EINVAL); 532 count += bv->bv_len >> (block->s2b_shift + 9); 533 } 534 /* Paranoia. */ 535 if (count != last_rec - first_rec + 1) 536 return ERR_PTR(-EINVAL); 537 /* Build the request */ 538 datasize = sizeof(struct dasd_diag_req) + 539 count*sizeof(struct dasd_diag_bio); 540 cqr = dasd_smalloc_request(DASD_DIAG_MAGIC, 0, datasize, memdev); 541 if (IS_ERR(cqr)) 542 return cqr; 543 544 dreq = (struct dasd_diag_req *) cqr->data; 545 dreq->block_count = count; 546 dbio = dreq->bio; 547 recid = first_rec; 548 rq_for_each_segment(bv, req, iter) { 549 dst = page_address(bv->bv_page) + bv->bv_offset; 550 for (off = 0; off < bv->bv_len; off += blksize) { 551 memset(dbio, 0, sizeof (struct dasd_diag_bio)); 552 dbio->type = rw_cmd; 553 dbio->block_number = recid + 1; 554 dbio->buffer = dst; 555 dbio++; 556 dst += blksize; 557 recid++; 558 } 559 } 560 cqr->retries = DIAG_MAX_RETRIES; 561 cqr->buildclk = get_clock(); 562 if (blk_noretry_request(req) || 563 block->base->features & DASD_FEATURE_FAILFAST) 564 set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags); 565 cqr->startdev = memdev; 566 cqr->memdev = memdev; 567 cqr->block = block; 568 cqr->expires = DIAG_TIMEOUT; 569 cqr->status = DASD_CQR_FILLED; 570 return cqr; 571 } 572 573 /* Release DASD request. Return non-zero if request was successful, zero 574 * otherwise. */ 575 static int 576 dasd_diag_free_cp(struct dasd_ccw_req *cqr, struct request *req) 577 { 578 int status; 579 580 status = cqr->status == DASD_CQR_DONE; 581 dasd_sfree_request(cqr, cqr->memdev); 582 return status; 583 } 584 585 static void dasd_diag_handle_terminated_request(struct dasd_ccw_req *cqr) 586 { 587 cqr->status = DASD_CQR_FILLED; 588 }; 589 590 /* Fill in IOCTL data for device. */ 591 static int 592 dasd_diag_fill_info(struct dasd_device * device, 593 struct dasd_information2_t * info) 594 { 595 struct dasd_diag_private *private; 596 597 private = (struct dasd_diag_private *) device->private; 598 info->label_block = (unsigned int) private->pt_block; 599 info->FBA_layout = 1; 600 info->format = DASD_FORMAT_LDL; 601 info->characteristics_size = sizeof (struct dasd_diag_characteristics); 602 memcpy(info->characteristics, 603 &((struct dasd_diag_private *) device->private)->rdc_data, 604 sizeof (struct dasd_diag_characteristics)); 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 .fill_geometry = dasd_diag_fill_geometry, 624 .start_IO = dasd_start_diag, 625 .term_IO = dasd_diag_term_IO, 626 .handle_terminated_request = dasd_diag_handle_terminated_request, 627 .erp_action = dasd_diag_erp_action, 628 .erp_postaction = dasd_diag_erp_postaction, 629 .build_cp = dasd_diag_build_cp, 630 .free_cp = dasd_diag_free_cp, 631 .dump_sense = dasd_diag_dump_sense, 632 .fill_info = dasd_diag_fill_info, 633 }; 634 635 static int __init 636 dasd_diag_init(void) 637 { 638 if (!MACHINE_IS_VM) { 639 pr_info("Discipline %s cannot be used without z/VM\n", 640 dasd_diag_discipline.name); 641 return -ENODEV; 642 } 643 ASCEBC(dasd_diag_discipline.ebcname, 4); 644 645 ctl_set_bit(0, 9); 646 register_external_interrupt(0x2603, dasd_ext_handler); 647 dasd_diag_discipline_pointer = &dasd_diag_discipline; 648 return 0; 649 } 650 651 static void __exit 652 dasd_diag_cleanup(void) 653 { 654 unregister_external_interrupt(0x2603, dasd_ext_handler); 655 ctl_clear_bit(0, 9); 656 dasd_diag_discipline_pointer = NULL; 657 } 658 659 module_init(dasd_diag_init); 660 module_exit(dasd_diag_cleanup); 661