drivers/s390/block/dasd.c

   1 /*
   2  * File...........: linux/drivers/s390/block/dasd.c
   3  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
   4  *                  Horst Hummel <Horst.Hummel@de.ibm.com>
   5  *                  Carsten Otte <Cotte@de.ibm.com>
   6  *                  Martin Schwidefsky <schwidefsky@de.ibm.com>
   7  * Bugreports.to..: <Linux390@de.ibm.com>
   8  * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999-2001
   9  *
  10  * $Revision: 1.167 $
  11  */
  12
  13 #include <linux/config.h>
  14 #include <linux/kmod.h>
  15 #include <linux/init.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/ctype.h>
  18 #include <linux/major.h>
  19 #include <linux/slab.h>
  20 #include <linux/buffer_head.h>
  21
  22 #include <asm/ccwdev.h>
  23 #include <asm/ebcdic.h>
  24 #include <asm/idals.h>
  25 #include <asm/todclk.h>
  26
  27 /* This is ugly... */
  28 #define PRINTK_HEADER "dasd:"
  29
  30 #include "dasd_int.h"
  31 /*
  32  * SECTION: Constant definitions to be used within this file
  33  */
  34 #define DASD_CHANQ_MAX_SIZE 4
  35
  36 /*
  37  * SECTION: exported variables of dasd.c
  38  */
  39 debug_info_t *dasd_debug_area;
  40 struct dasd_discipline *dasd_diag_discipline_pointer;
  41
  42 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
  43 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
  44                    " Copyright 2000 IBM Corporation");
  45 MODULE_SUPPORTED_DEVICE("dasd");
  46 MODULE_PARM(dasd, "1-" __MODULE_STRING(256) "s");
  47 MODULE_LICENSE("GPL");
  48
  49 /*
  50  * SECTION: prototypes for static functions of dasd.c
  51  */
  52 static int  dasd_alloc_queue(struct dasd_device * device);
  53 static void dasd_setup_queue(struct dasd_device * device);
  54 static void dasd_free_queue(struct dasd_device * device);
  55 static void dasd_flush_request_queue(struct dasd_device *);
  56 static void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
  57 static void dasd_flush_ccw_queue(struct dasd_device *, int);
  58 static void dasd_tasklet(struct dasd_device *);
  59 static void do_kick_device(void *data);
  60
  61 /*
  62  * SECTION: Operations on the device structure.
  63  */
  64 static wait_queue_head_t dasd_init_waitq;
  65
  66 /*
  67  * Allocate memory for a new device structure.
  68  */
  69 struct dasd_device *
  70 dasd_alloc_device(void)
  71 {
  72         struct dasd_device *device;
  73
  74         device = kmalloc(sizeof (struct dasd_device), GFP_ATOMIC);
  75         if (device == NULL)
  76                 return ERR_PTR(-ENOMEM);
  77         memset(device, 0, sizeof (struct dasd_device));
  78         /* open_count = 0 means device online but not in use */
  79         atomic_set(&device->open_count, -1);
  80
  81         /* Get two pages for normal block device operations. */
  82         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
  83         if (device->ccw_mem == NULL) {
  84                 kfree(device);
  85                 return ERR_PTR(-ENOMEM);
  86         }
  87         /* Get one page for error recovery. */
  88         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
  89         if (device->erp_mem == NULL) {
  90                 free_pages((unsigned long) device->ccw_mem, 1);
  91                 kfree(device);
  92                 return ERR_PTR(-ENOMEM);
  93         }
  94
  95         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
  96         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
  97         spin_lock_init(&device->mem_lock);
  98         spin_lock_init(&device->request_queue_lock);
  99         atomic_set (&device->tasklet_scheduled, 0);
 100         tasklet_init(&device->tasklet,
 101                      (void (*)(unsigned long)) dasd_tasklet,
 102                      (unsigned long) device);
 103         INIT_LIST_HEAD(&device->ccw_queue);
 104         init_timer(&device->timer);
 105         INIT_WORK(&device->kick_work, do_kick_device, device);
 106         device->state = DASD_STATE_NEW;
 107         device->target = DASD_STATE_NEW;
 108
 109         return device;
 110 }
 111
 112 /*
 113  * Free memory of a device structure.
 114  */
 115 void
 116 dasd_free_device(struct dasd_device *device)
 117 {
 118         kfree(device->private);
 119         free_page((unsigned long) device->erp_mem);
 120         free_pages((unsigned long) device->ccw_mem, 1);
 121         kfree(device);
 122 }
 123
 124 /*
 125  * Make a new device known to the system.
 126  */
 127 static inline int
 128 dasd_state_new_to_known(struct dasd_device *device)
 129 {
 130         int rc;
 131
 132         /*
 133          * As long as the device is not in state DASD_STATE_NEW we want to
 134          * keep the reference count > 0.
 135          */
 136         dasd_get_device(device);
 137
 138         rc = dasd_alloc_queue(device);
 139         if (rc) {
 140                 dasd_put_device(device);
 141                 return rc;
 142         }
 143
 144         device->state = DASD_STATE_KNOWN;
 145         return 0;
 146 }
 147
 148 /*
 149  * Let the system forget about a device.
 150  */
 151 static inline void
 152 dasd_state_known_to_new(struct dasd_device * device)
 153 {
 154         /* Forget the discipline information. */
 155         device->discipline = NULL;
 156         device->state = DASD_STATE_NEW;
 157
 158         dasd_free_queue(device);
 159
 160         /* Give up reference we took in dasd_state_new_to_known. */
 161         dasd_put_device(device);
 162 }
 163
 164 /*
 165  * Request the irq line for the device.
 166  */
 167 static inline int
 168 dasd_state_known_to_basic(struct dasd_device * device)
 169 {
 170         int rc;
 171
 172         /* Allocate and register gendisk structure. */
 173         rc = dasd_gendisk_alloc(device);
 174         if (rc)
 175                 return rc;
 176
 177         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 178         device->debug_area = debug_register(device->cdev->dev.bus_id, 1, 2,
 179                                             8 * sizeof (long));
 180         debug_register_view(device->debug_area, &debug_sprintf_view);
 181         debug_set_level(device->debug_area, DBF_EMERG);
 182         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 183
 184         device->state = DASD_STATE_BASIC;
 185         return 0;
 186 }
 187
 188 /*
 189  * Release the irq line for the device. Terminate any running i/o.
 190  */
 191 static inline void
 192 dasd_state_basic_to_known(struct dasd_device * device)
 193 {
 194         dasd_gendisk_free(device);
 195         dasd_flush_ccw_queue(device, 1);
 196         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
 197         if (device->debug_area != NULL) {
 198                 debug_unregister(device->debug_area);
 199                 device->debug_area = NULL;
 200         }
 201         device->state = DASD_STATE_KNOWN;
 202 }
 203
 204 /*
 205  * Do the initial analysis. The do_analysis function may return
 206  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 207  * until the discipline decides to continue the startup sequence
 208  * by calling the function dasd_change_state. The eckd disciplines
 209  * uses this to start a ccw that detects the format. The completion
 210  * interrupt for this detection ccw uses the kernel event daemon to
 211  * trigger the call to dasd_change_state. All this is done in the
 212  * discipline code, see dasd_eckd.c.
 213  * After the analysis ccw is done (do_analysis returned 0 or error)
 214  * the block device is setup. Either a fake disk is added to allow
 215  * formatting or a proper device request queue is created.
 216  */
 217 static inline int
 218 dasd_state_basic_to_ready(struct dasd_device * device)
 219 {
 220         int rc;
 221
 222         rc = 0;
 223         if (device->discipline->do_analysis != NULL)
 224                 rc = device->discipline->do_analysis(device);
 225         if (rc)
 226                 return rc;
 227         dasd_setup_queue(device);
 228         device->state = DASD_STATE_READY;
 229         if (dasd_scan_partitions(device) != 0)
 230                 device->state = DASD_STATE_BASIC;
 231         return 0;
 232 }
 233
 234 /*
 235  * Remove device from block device layer. Destroy dirty buffers.
 236  * Forget format information. Check if the target level is basic
 237  * and if it is create fake disk for formatting.
 238  */
 239 static inline void
 240 dasd_state_ready_to_basic(struct dasd_device * device)
 241 {
 242         dasd_flush_ccw_queue(device, 0);
 243         dasd_destroy_partitions(device);
 244         dasd_flush_request_queue(device);
 245         device->blocks = 0;
 246         device->bp_block = 0;
 247         device->s2b_shift = 0;
 248         device->state = DASD_STATE_BASIC;
 249 }
 250
 251 /*
 252  * Make the device online and schedule the bottom half to start
 253  * the requeueing of requests from the linux request queue to the
 254  * ccw queue.
 255  */
 256 static inline int
 257 dasd_state_ready_to_online(struct dasd_device * device)
 258 {
 259         device->state = DASD_STATE_ONLINE;
 260         dasd_schedule_bh(device);
 261         return 0;
 262 }
 263
 264 /*
 265  * Stop the requeueing of requests again.
 266  */
 267 static inline void
 268 dasd_state_online_to_ready(struct dasd_device * device)
 269 {
 270         device->state = DASD_STATE_READY;
 271 }
 272
 273 /*
 274  * Device startup state changes.
 275  */
 276 static inline int
 277 dasd_increase_state(struct dasd_device *device)
 278 {
 279         int rc;
 280
 281         rc = 0;
 282         if (device->state == DASD_STATE_NEW &&
 283             device->target >= DASD_STATE_KNOWN)
 284                 rc = dasd_state_new_to_known(device);
 285
 286         if (!rc &&
 287             device->state == DASD_STATE_KNOWN &&
 288             device->target >= DASD_STATE_BASIC)
 289                 rc = dasd_state_known_to_basic(device);
 290
 291         if (!rc &&
 292             device->state == DASD_STATE_BASIC &&
 293             device->target >= DASD_STATE_READY)
 294                 rc = dasd_state_basic_to_ready(device);
 295
 296         if (!rc &&
 297             device->state == DASD_STATE_READY &&
 298             device->target >= DASD_STATE_ONLINE)
 299                 rc = dasd_state_ready_to_online(device);
 300
 301         return rc;
 302 }
 303
 304 /*
 305  * Device shutdown state changes.
 306  */
 307 static inline int
 308 dasd_decrease_state(struct dasd_device *device)
 309 {
 310         if (device->state == DASD_STATE_ONLINE &&
 311             device->target <= DASD_STATE_READY)
 312                 dasd_state_online_to_ready(device);
 313
 314         if (device->state == DASD_STATE_READY &&
 315             device->target <= DASD_STATE_BASIC)
 316                 dasd_state_ready_to_basic(device);
 317
 318         if (device->state == DASD_STATE_BASIC &&
 319             device->target <= DASD_STATE_KNOWN)
 320                 dasd_state_basic_to_known(device);
 321
 322         if (device->state == DASD_STATE_KNOWN &&
 323             device->target <= DASD_STATE_NEW)
 324                 dasd_state_known_to_new(device);
 325
 326         return 0;
 327 }
 328
 329 /*
 330  * This is the main startup/shutdown routine.
 331  */
 332 static void
 333 dasd_change_state(struct dasd_device *device)
 334 {
 335         int rc;
 336
 337         if (device->state == device->target)
 338                 /* Already where we want to go today... */
 339                 return;
 340         if (device->state < device->target)
 341                 rc = dasd_increase_state(device);
 342         else
 343                 rc = dasd_decrease_state(device);
 344         if (rc && rc != -EAGAIN)
 345                 device->target = device->state;
 346
 347         if (device->state == device->target)
 348                 wake_up(&dasd_init_waitq);
 349 }
 350
 351 /*
 352  * Kick starter for devices that did not complete the startup/shutdown
 353  * procedure or were sleeping because of a pending state.
 354  * dasd_kick_device will schedule a call do do_kick_device to the kernel
 355  * event daemon.
 356  */
 357 static void
 358 do_kick_device(void *data)
 359 {
 360         struct dasd_device *device;
 361
 362         device = (struct dasd_device *) data;
 363         dasd_change_state(device);
 364         dasd_schedule_bh(device);
 365         dasd_put_device(device);
 366 }
 367
 368 void
 369 dasd_kick_device(struct dasd_device *device)
 370 {
 371         dasd_get_device(device);
 372         /* queue call to dasd_kick_device to the kernel event daemon. */
 373         schedule_work(&device->kick_work);
 374 }
 375
 376 /*
 377  * Set the target state for a device and starts the state change.
 378  */
 379 void
 380 dasd_set_target_state(struct dasd_device *device, int target)
 381 {
 382         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 383         if (dasd_probeonly && target > DASD_STATE_READY)
 384                 target = DASD_STATE_READY;
 385         if (device->target != target) {
 386                 if (device->state == target)
 387                         wake_up(&dasd_init_waitq);
 388                 device->target = target;
 389         }
 390         if (device->state != device->target)
 391                 dasd_change_state(device);
 392 }
 393
 394 /*
 395  * Enable devices with device numbers in [from..to].
 396  */
 397 static inline int
 398 _wait_for_device(struct dasd_device *device)
 399 {
 400         return (device->state == device->target);
 401 }
 402
 403 void
 404 dasd_enable_device(struct dasd_device *device)
 405 {
 406         dasd_set_target_state(device, DASD_STATE_ONLINE);
 407         if (device->state <= DASD_STATE_KNOWN)
 408                 /* No discipline for device found. */
 409                 dasd_set_target_state(device, DASD_STATE_NEW);
 410         /* Now wait for the devices to come up. */
 411         wait_event(dasd_init_waitq, _wait_for_device(device));
 412 }
 413
 414 /*
 415  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 416  */
 417 #ifdef CONFIG_DASD_PROFILE
 418
 419 struct dasd_profile_info_t dasd_global_profile;
 420 unsigned int dasd_profile_level = DASD_PROFILE_OFF;
 421
 422 /*
 423  * Increments counter in global and local profiling structures.
 424  */
 425 #define dasd_profile_counter(value, counter, device) \
 426 { \
 427         int index; \
 428         for (index = 0; index < 31 && value >> (2+index); index++); \
 429         dasd_global_profile.counter[index]++; \
 430         device->profile.counter[index]++; \
 431 }
 432
 433 /*
 434  * Add profiling information for cqr before execution.
 435  */
 436 static inline void
 437 dasd_profile_start(struct dasd_device *device, struct dasd_ccw_req * cqr,
 438                    struct request *req)
 439 {
 440         struct list_head *l;
 441         unsigned int counter;
 442
 443         if (dasd_profile_level != DASD_PROFILE_ON)
 444                 return;
 445
 446         /* count the length of the chanq for statistics */
 447         counter = 0;
 448         list_for_each(l, &device->ccw_queue)
 449                 if (++counter >= 31)
 450                         break;
 451         dasd_global_profile.dasd_io_nr_req[counter]++;
 452         device->profile.dasd_io_nr_req[counter]++;
 453 }
 454
 455 /*
 456  * Add profiling information for cqr after execution.
 457  */
 458 static inline void
 459 dasd_profile_end(struct dasd_device *device, struct dasd_ccw_req * cqr,
 460                  struct request *req)
 461 {
 462         long strtime, irqtime, endtime, tottime;        /* in microseconds */
 463         long tottimeps, sectors;
 464
 465         if (dasd_profile_level != DASD_PROFILE_ON)
 466                 return;
 467
 468         sectors = req->nr_sectors;
 469         if (!cqr->buildclk || !cqr->startclk ||
 470             !cqr->stopclk || !cqr->endclk ||
 471             !sectors)
 472                 return;
 473
 474         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 475         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 476         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 477         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 478         tottimeps = tottime / sectors;
 479
 480         if (!dasd_global_profile.dasd_io_reqs)
 481                 memset(&dasd_global_profile, 0,
 482                        sizeof (struct dasd_profile_info_t));
 483         dasd_global_profile.dasd_io_reqs++;
 484         dasd_global_profile.dasd_io_sects += sectors;
 485
 486         if (!device->profile.dasd_io_reqs)
 487                 memset(&device->profile, 0,
 488                        sizeof (struct dasd_profile_info_t));
 489         device->profile.dasd_io_reqs++;
 490         device->profile.dasd_io_sects += sectors;
 491
 492         dasd_profile_counter(sectors, dasd_io_secs, device);
 493         dasd_profile_counter(tottime, dasd_io_times, device);
 494         dasd_profile_counter(tottimeps, dasd_io_timps, device);
 495         dasd_profile_counter(strtime, dasd_io_time1, device);
 496         dasd_profile_counter(irqtime, dasd_io_time2, device);
 497         dasd_profile_counter(irqtime / sectors, dasd_io_time2ps, device);
 498         dasd_profile_counter(endtime, dasd_io_time3, device);
 499 }
 500 #else
 501 #define dasd_profile_start(device, cqr, req) do {} while (0)
 502 #define dasd_profile_end(device, cqr, req) do {} while (0)
 503 #endif                          /* CONFIG_DASD_PROFILE */
 504
 505 /*
 506  * Allocate memory for a channel program with 'cplength' channel
 507  * command words and 'datasize' additional space. There are two
 508  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
 509  * memory and 2) dasd_smalloc_request uses the static ccw memory
 510  * that gets allocated for each device.
 511  */
 512 struct dasd_ccw_req *
 513 dasd_kmalloc_request(char *magic, int cplength, int datasize,
 514                    struct dasd_device * device)
 515 {
 516         struct dasd_ccw_req *cqr;
 517
 518         /* Sanity checks */
 519         if ( magic == NULL || datasize > PAGE_SIZE ||
 520              (cplength*sizeof(struct ccw1)) > PAGE_SIZE)
 521                 BUG();
 522
 523         cqr = kmalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
 524         if (cqr == NULL)
 525                 return ERR_PTR(-ENOMEM);
 526         memset(cqr, 0, sizeof(struct dasd_ccw_req));
 527         cqr->cpaddr = NULL;
 528         if (cplength > 0) {
 529                 cqr->cpaddr = kmalloc(cplength*sizeof(struct ccw1),
 530                                       GFP_ATOMIC | GFP_DMA);
 531                 if (cqr->cpaddr == NULL) {
 532                         kfree(cqr);
 533                         return ERR_PTR(-ENOMEM);
 534                 }
 535                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
 536         }
 537         cqr->data = NULL;
 538         if (datasize > 0) {
 539                 cqr->data = kmalloc(datasize, GFP_ATOMIC | GFP_DMA);
 540                 if (cqr->data == NULL) {
 541                         kfree(cqr->cpaddr);
 542                         kfree(cqr);
 543                         return ERR_PTR(-ENOMEM);
 544                 }
 545                 memset(cqr->data, 0, datasize);
 546         }
 547         strncpy((char *) &cqr->magic, magic, 4);
 548         ASCEBC((char *) &cqr->magic, 4);
 549         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
 550         dasd_get_device(device);
 551         return cqr;
 552 }
 553
 554 struct dasd_ccw_req *
 555 dasd_smalloc_request(char *magic, int cplength, int datasize,
 556                    struct dasd_device * device)
 557 {
 558         unsigned long flags;
 559         struct dasd_ccw_req *cqr;
 560         char *data;
 561         int size;
 562
 563         /* Sanity checks */
 564         if ( magic == NULL || datasize > PAGE_SIZE ||
 565              (cplength*sizeof(struct ccw1)) > PAGE_SIZE)
 566                 BUG();
 567
 568         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
 569         if (cplength > 0)
 570                 size += cplength * sizeof(struct ccw1);
 571         if (datasize > 0)
 572                 size += datasize;
 573         spin_lock_irqsave(&device->mem_lock, flags);
 574         cqr = (struct dasd_ccw_req *)
 575                 dasd_alloc_chunk(&device->ccw_chunks, size);
 576         spin_unlock_irqrestore(&device->mem_lock, flags);
 577         if (cqr == NULL)
 578                 return ERR_PTR(-ENOMEM);
 579         memset(cqr, 0, sizeof(struct dasd_ccw_req));
 580         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
 581         cqr->cpaddr = NULL;
 582         if (cplength > 0) {
 583                 cqr->cpaddr = (struct ccw1 *) data;
 584                 data += cplength*sizeof(struct ccw1);
 585                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
 586         }
 587         cqr->data = NULL;
 588         if (datasize > 0) {
 589                 cqr->data = data;
 590                 memset(cqr->data, 0, datasize);
 591         }
 592         strncpy((char *) &cqr->magic, magic, 4);
 593         ASCEBC((char *) &cqr->magic, 4);
 594         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
 595         dasd_get_device(device);
 596         return cqr;
 597 }
 598
 599 /*
 600  * Free memory of a channel program. This function needs to free all the
 601  * idal lists that might have been created by dasd_set_cda and the
 602  * struct dasd_ccw_req itself.
 603  */
 604 void
 605 dasd_kfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
 606 {
 607 #ifdef CONFIG_ARCH_S390X
 608         struct ccw1 *ccw;
 609
 610         /* Clear any idals used for the request. */
 611         ccw = cqr->cpaddr;
 612         do {
 613                 clear_normalized_cda(ccw);
 614         } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
 615 #endif
 616         kfree(cqr->cpaddr);
 617         kfree(cqr->data);
 618         kfree(cqr);
 619         dasd_put_device(device);
 620 }
 621
 622 void
 623 dasd_sfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
 624 {
 625         unsigned long flags;
 626
 627         spin_lock_irqsave(&device->mem_lock, flags);
 628         dasd_free_chunk(&device->ccw_chunks, cqr);
 629         spin_unlock_irqrestore(&device->mem_lock, flags);
 630         dasd_put_device(device);
 631 }
 632
 633 /*
 634  * Check discipline magic in cqr.
 635  */
 636 static inline int
 637 dasd_check_cqr(struct dasd_ccw_req *cqr)
 638 {
 639         struct dasd_device *device;
 640
 641         if (cqr == NULL)
 642                 return -EINVAL;
 643         device = cqr->device;
 644         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
 645                 DEV_MESSAGE(KERN_WARNING, device,
 646                             " dasd_ccw_req 0x%08x magic doesn't match"
 647                             " discipline 0x%08x",
 648                             cqr->magic,
 649                             *(unsigned int *) device->discipline->name);
 650                 return -EINVAL;
 651         }
 652         return 0;
 653 }
 654
 655 /*
 656  * Terminate the current i/o and set the request to clear_pending.
 657  * Timer keeps device runnig.
 658  * ccw_device_clear can fail if the i/o subsystem
 659  * is in a bad mood.
 660  */
 661 int
 662 dasd_term_IO(struct dasd_ccw_req * cqr)
 663 {
 664         struct dasd_device *device;
 665         int retries, rc;
 666
 667         /* Check the cqr */
 668         rc = dasd_check_cqr(cqr);
 669         if (rc)
 670                 return rc;
 671         retries = 0;
 672         device = (struct dasd_device *) cqr->device;
 673         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
 674                 rc = ccw_device_clear(device->cdev, (long) cqr);
 675                 switch (rc) {
 676                 case 0: /* termination successful */
 677                         if (cqr->retries > 0) {
 678                                 cqr->retries--;
 679                                 cqr->status = DASD_CQR_CLEAR;
 680                         } else
 681                                 cqr->status = DASD_CQR_FAILED;
 682                         cqr->stopclk = get_clock();
 683                         DBF_DEV_EVENT(DBF_DEBUG, device,
 684                                       "terminate cqr %p successful",
 685                                       cqr);
 686                         break;
 687                 case -ENODEV:
 688                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 689                                       "device gone, retry");
 690                         break;
 691                 case -EIO:
 692                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 693                                       "I/O error, retry");
 694                         break;
 695                 case -EINVAL:
 696                 case -EBUSY:
 697                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 698                                       "device busy, retry later");
 699                         break;
 700                 default:
 701                         DEV_MESSAGE(KERN_ERR, device,
 702                                     "line %d unknown RC=%d, please "
 703                                     "report to linux390@de.ibm.com",
 704                                     __LINE__, rc);
 705                         BUG();
 706                         break;
 707                 }
 708                 retries++;
 709         }
 710         dasd_schedule_bh(device);
 711         return rc;
 712 }
 713
 714 /*
 715  * Start the i/o. This start_IO can fail if the channel is really busy.
 716  * In that case set up a timer to start the request later.
 717  */
 718 int
 719 dasd_start_IO(struct dasd_ccw_req * cqr)
 720 {
 721         struct dasd_device *device;
 722         int rc;
 723
 724         /* Check the cqr */
 725         rc = dasd_check_cqr(cqr);
 726         if (rc)
 727                 return rc;
 728         device = (struct dasd_device *) cqr->device;
 729         if (cqr->retries < 0) {
 730                 DEV_MESSAGE(KERN_DEBUG, device,
 731                             "start_IO: request %p (%02x/%i) - no retry left.",
 732                             cqr, cqr->status, cqr->retries);
 733                 cqr->status = DASD_CQR_FAILED;
 734                 return -EIO;
 735         }
 736         cqr->startclk = get_clock();
 737         cqr->starttime = jiffies;
 738         cqr->retries--;
 739         rc = ccw_device_start(device->cdev, cqr->cpaddr, (long) cqr,
 740                               cqr->lpm, 0);
 741         switch (rc) {
 742         case 0:
 743                 cqr->status = DASD_CQR_IN_IO;
 744                 DBF_DEV_EVENT(DBF_DEBUG, device,
 745                               "start_IO: request %p started successful",
 746                               cqr);
 747                 break;
 748         case -EBUSY:
 749                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 750                               "start_IO: device busy, retry later");
 751                 break;
 752         case -ETIMEDOUT:
 753                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 754                               "start_IO: request timeout, retry later");
 755                 break;
 756         case -EACCES:
 757                 /* -EACCES indicates that the request used only a
 758                  * subset of the available pathes and all these
 759                  * pathes are gone.
 760                  * Do a retry with all available pathes.
 761                  */
 762                 cqr->lpm = LPM_ANYPATH;
 763                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 764                               "start_IO: selected pathes gone,"
 765                               " retry on all pathes");
 766                 break;
 767         case -ENODEV:
 768         case -EIO:
 769                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 770                               "start_IO: device gone, retry");
 771                 break;
 772         default:
 773                 DEV_MESSAGE(KERN_ERR, device,
 774                             "line %d unknown RC=%d, please report"
 775                             " to linux390@de.ibm.com", __LINE__, rc);
 776                 BUG();
 777                 break;
 778         }
 779         return rc;
 780 }
 781
 782 /*
 783  * Timeout function for dasd devices. This is used for different purposes
 784  *  1) missing interrupt handler for normal operation
 785  *  2) delayed start of request where start_IO failed with -EBUSY
 786  *  3) timeout for missing state change interrupts
 787  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
 788  * DASD_CQR_QUEUED for 2) and 3).
 789  */
 790 static void
 791 dasd_timeout_device(unsigned long ptr)
 792 {
 793         unsigned long flags;
 794         struct dasd_device *device;
 795
 796         device = (struct dasd_device *) ptr;
 797         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
 798         /* re-activate request queue */
 799         device->stopped &= ~DASD_STOPPED_PENDING;
 800         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
 801         dasd_schedule_bh(device);
 802 }
 803
 804 /*
 805  * Setup timeout for a device in jiffies.
 806  */
 807 void
 808 dasd_set_timer(struct dasd_device *device, int expires)
 809 {
 810         if (expires == 0) {
 811                 if (timer_pending(&device->timer))
 812                         del_timer(&device->timer);
 813                 return;
 814         }
 815         if (timer_pending(&device->timer)) {
 816                 if (mod_timer(&device->timer, jiffies + expires))
 817                         return;
 818         }
 819         device->timer.function = dasd_timeout_device;
 820         device->timer.data = (unsigned long) device;
 821         device->timer.expires = jiffies + expires;
 822         add_timer(&device->timer);
 823 }
 824
 825 /*
 826  * Clear timeout for a device.
 827  */
 828 void
 829 dasd_clear_timer(struct dasd_device *device)
 830 {
 831         if (timer_pending(&device->timer))
 832                 del_timer(&device->timer);
 833 }
 834
 835 static void
 836 dasd_handle_killed_request(struct ccw_device *cdev, unsigned long intparm)
 837 {
 838         struct dasd_ccw_req *cqr;
 839         struct dasd_device *device;
 840
 841         cqr = (struct dasd_ccw_req *) intparm;
 842         if (cqr->status != DASD_CQR_IN_IO) {
 843                 MESSAGE(KERN_DEBUG,
 844                         "invalid status in handle_killed_request: "
 845                         "bus_id %s, status %02x",
 846                         cdev->dev.bus_id, cqr->status);
 847                 return;
 848         }
 849
 850         device = (struct dasd_device *) cqr->device;
 851         if (device == NULL ||
 852             device != dasd_device_from_cdev(cdev) ||
 853             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
 854                 MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
 855                         cdev->dev.bus_id);
 856                 return;
 857         }
 858
 859         /* Schedule request to be retried. */
 860         cqr->status = DASD_CQR_QUEUED;
 861
 862         dasd_clear_timer(device);
 863         dasd_schedule_bh(device);
 864         dasd_put_device(device);
 865 }
 866
 867 static void
 868 dasd_handle_state_change_pending(struct dasd_device *device)
 869 {
 870         struct dasd_ccw_req *cqr;
 871         struct list_head *l, *n;
 872
 873         device->stopped &= ~DASD_STOPPED_PENDING;
 874
 875         /* restart all 'running' IO on queue */
 876         list_for_each_safe(l, n, &device->ccw_queue) {
 877                 cqr = list_entry(l, struct dasd_ccw_req, list);
 878                 if (cqr->status == DASD_CQR_IN_IO) {
 879                         cqr->status = DASD_CQR_QUEUED;
 880                 }
 881         }
 882         dasd_clear_timer(device);
 883         dasd_schedule_bh(device);
 884 }
 885
 886 /*
 887  * Interrupt handler for "normal" ssch-io based dasd devices.
 888  */
 889 void
 890 dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
 891                  struct irb *irb)
 892 {
 893         struct dasd_ccw_req *cqr, *next;
 894         struct dasd_device *device;
 895         unsigned long long now;
 896         int expires;
 897         dasd_era_t era;
 898         char mask;
 899
 900         if (IS_ERR(irb)) {
 901                 switch (PTR_ERR(irb)) {
 902                 case -EIO:
 903                         dasd_handle_killed_request(cdev, intparm);
 904                         break;
 905                 case -ETIMEDOUT:
 906                         printk(KERN_WARNING"%s(%s): request timed out\n",
 907                                __FUNCTION__, cdev->dev.bus_id);
 908                         //FIXME - dasd uses own timeout interface...
 909                         break;
 910                 default:
 911                         printk(KERN_WARNING"%s(%s): unknown error %ld\n",
 912                                __FUNCTION__, cdev->dev.bus_id, PTR_ERR(irb));
 913                 }
 914                 return;
 915         }
 916
 917         now = get_clock();
 918
 919         DBF_EVENT(DBF_ERR, "Interrupt: bus_id %s CS/DS %04x ip %08x",
 920                   cdev->dev.bus_id, ((irb->scsw.cstat<<8)|irb->scsw.dstat),
 921                   (unsigned int) intparm);
 922
 923         /* first of all check for state change pending interrupt */
 924         mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP;
 925         if ((irb->scsw.dstat & mask) == mask) {
 926                 device = dasd_device_from_cdev(cdev);
 927                 if (!IS_ERR(device)) {
 928                         dasd_handle_state_change_pending(device);
 929                         dasd_put_device(device);
 930                 }
 931                 return;
 932         }
 933
 934         cqr = (struct dasd_ccw_req *) intparm;
 935
 936         /* check for unsolicited interrupts */
 937         if (cqr == NULL) {
 938                 MESSAGE(KERN_DEBUG,
 939                         "unsolicited interrupt received: bus_id %s",
 940                         cdev->dev.bus_id);
 941                 return;
 942         }
 943
 944         device = (struct dasd_device *) cqr->device;
 945         if (device == NULL ||
 946             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
 947                 MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
 948                         cdev->dev.bus_id);
 949                 return;
 950         }
 951
 952         /* Check for clear pending */
 953         if (cqr->status == DASD_CQR_CLEAR &&
 954             irb->scsw.fctl & SCSW_FCTL_CLEAR_FUNC) {
 955                 cqr->status = DASD_CQR_QUEUED;
 956                 dasd_clear_timer(device);
 957                 dasd_schedule_bh(device);
 958                 return;
 959         }
 960
 961         /* check status - the request might have been killed by dyn detach */
 962         if (cqr->status != DASD_CQR_IN_IO) {
 963                 MESSAGE(KERN_DEBUG,
 964                         "invalid status: bus_id %s, status %02x",
 965                         cdev->dev.bus_id, cqr->status);
 966                 return;
 967         }
 968         DBF_DEV_EVENT(DBF_DEBUG, device, "Int: CS/DS 0x%04x for cqr %p",
 969                       ((irb->scsw.cstat << 8) | irb->scsw.dstat), cqr);
 970
 971         /* Find out the appropriate era_action. */
 972         if (irb->scsw.fctl & SCSW_FCTL_HALT_FUNC)
 973                 era = dasd_era_fatal;
 974         else if (irb->scsw.dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
 975                  irb->scsw.cstat == 0 &&
 976                  !irb->esw.esw0.erw.cons)
 977                 era = dasd_era_none;
 978         else if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags))
 979                 era = dasd_era_fatal; /* don't recover this request */
 980         else if (irb->esw.esw0.erw.cons)
 981                 era = device->discipline->examine_error(cqr, irb);
 982         else
 983                 era = dasd_era_recover;
 984
 985         DBF_DEV_EVENT(DBF_DEBUG, device, "era_code %d", era);
 986         expires = 0;
 987         if (era == dasd_era_none) {
 988                 cqr->status = DASD_CQR_DONE;
 989                 cqr->stopclk = now;
 990                 /* Start first request on queue if possible -> fast_io. */
 991                 if (cqr->list.next != &device->ccw_queue) {
 992                         next = list_entry(cqr->list.next,
 993                                           struct dasd_ccw_req, list);
 994                         if ((next->status == DASD_CQR_QUEUED) &&
 995                             (!device->stopped)) {
 996                                 if (device->discipline->start_IO(next) == 0)
 997                                         expires = next->expires;
 998                                 else
 999                                         DEV_MESSAGE(KERN_DEBUG, device, "%s",
1000                                                     "Interrupt fastpath "
1001                                                     "failed!");
1002                         }
1003                 }
1004         } else {                /* error */
1005                 memcpy(&cqr->irb, irb, sizeof (struct irb));
1006 #ifdef ERP_DEBUG
1007                 /* dump sense data */
1008                 dasd_log_sense(cqr, irb);
1009 #endif
1010                 switch (era) {
1011                 case dasd_era_fatal:
1012                         cqr->status = DASD_CQR_FAILED;
1013                         cqr->stopclk = now;
1014                         break;
1015                 case dasd_era_recover:
1016                         cqr->status = DASD_CQR_ERROR;
1017                         break;
1018                 default:
1019                         BUG();
1020                 }
1021         }
1022         if (expires != 0)
1023                 dasd_set_timer(device, expires);
1024         else
1025                 dasd_clear_timer(device);
1026         dasd_schedule_bh(device);
1027 }
1028
1029 /*
1030  * posts the buffer_cache about a finalized request
1031  */
1032 static inline void
1033 dasd_end_request(struct request *req, int uptodate)
1034 {
1035         if (end_that_request_first(req, uptodate, req->hard_nr_sectors))
1036                 BUG();
1037         add_disk_randomness(req->rq_disk);
1038         end_that_request_last(req);
1039 }
1040
1041 /*
1042  * Process finished error recovery ccw.
1043  */
1044 static inline void
1045 __dasd_process_erp(struct dasd_device *device, struct dasd_ccw_req *cqr)
1046 {
1047         dasd_erp_fn_t erp_fn;
1048
1049         if (cqr->status == DASD_CQR_DONE)
1050                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
1051         else
1052                 DEV_MESSAGE(KERN_ERR, device, "%s", "ERP unsuccessful");
1053         erp_fn = device->discipline->erp_postaction(cqr);
1054         erp_fn(cqr);
1055 }
1056
1057 /*
1058  * Process ccw request queue.
1059  */
1060 static inline void
1061 __dasd_process_ccw_queue(struct dasd_device * device,
1062                          struct list_head *final_queue)
1063 {
1064         struct list_head *l, *n;
1065         struct dasd_ccw_req *cqr;
1066         dasd_erp_fn_t erp_fn;
1067
1068 restart:
1069         /* Process request with final status. */
1070         list_for_each_safe(l, n, &device->ccw_queue) {
1071                 cqr = list_entry(l, struct dasd_ccw_req, list);
1072                 /* Stop list processing at the first non-final request. */
1073                 if (cqr->status != DASD_CQR_DONE &&
1074                     cqr->status != DASD_CQR_FAILED &&
1075                     cqr->status != DASD_CQR_ERROR)
1076                         break;
1077                 /*  Process requests with DASD_CQR_ERROR */
1078                 if (cqr->status == DASD_CQR_ERROR) {
1079                         if (cqr->irb.scsw.fctl & SCSW_FCTL_HALT_FUNC) {
1080                                 cqr->status = DASD_CQR_FAILED;
1081                                 cqr->stopclk = get_clock();
1082                         } else {
1083                                 if (cqr->irb.esw.esw0.erw.cons) {
1084                                         erp_fn = device->discipline->
1085                                                 erp_action(cqr);
1086                                         erp_fn(cqr);
1087                                 } else
1088                                         dasd_default_erp_action(cqr);
1089                         }
1090                         goto restart;
1091                 }
1092                 /* Process finished ERP request. */
1093                 if (cqr->refers) {
1094                         __dasd_process_erp(device, cqr);
1095                         goto restart;
1096                 }
1097
1098                 /* Rechain finished requests to final queue */
1099                 cqr->endclk = get_clock();
1100                 list_move_tail(&cqr->list, final_queue);
1101         }
1102 }
1103
1104 static void
1105 dasd_end_request_cb(struct dasd_ccw_req * cqr, void *data)
1106 {
1107         struct request *req;
1108         struct dasd_device *device;
1109         int status;
1110
1111         req = (struct request *) data;
1112         device = cqr->device;
1113         dasd_profile_end(device, cqr, req);
1114         status = cqr->device->discipline->free_cp(cqr,req);
1115         spin_lock_irq(&device->request_queue_lock);
1116         dasd_end_request(req, status);
1117         spin_unlock_irq(&device->request_queue_lock);
1118 }
1119
1120
1121 /*
1122  * Fetch requests from the block device queue.
1123  */
1124 static inline void
1125 __dasd_process_blk_queue(struct dasd_device * device)
1126 {
1127         request_queue_t *queue;
1128         struct request *req;
1129         struct dasd_ccw_req *cqr;
1130         int nr_queued;
1131
1132         queue = device->request_queue;
1133         /* No queue ? Then there is nothing to do. */
1134         if (queue == NULL)
1135                 return;
1136
1137         /*
1138          * We requeue request from the block device queue to the ccw
1139          * queue only in two states. In state DASD_STATE_READY the
1140          * partition detection is done and we need to requeue requests
1141          * for that. State DASD_STATE_ONLINE is normal block device
1142          * operation.
1143          */
1144         if (device->state != DASD_STATE_READY &&
1145             device->state != DASD_STATE_ONLINE)
1146                 return;
1147         nr_queued = 0;
1148         /* Now we try to fetch requests from the request queue */
1149         list_for_each_entry(cqr, &device->ccw_queue, list)
1150                 if (cqr->status == DASD_CQR_QUEUED)
1151                         nr_queued++;
1152         while (!blk_queue_plugged(queue) &&
1153                elv_next_request(queue) &&
1154                 nr_queued < DASD_CHANQ_MAX_SIZE) {
1155                 req = elv_next_request(queue);
1156
1157                 if (device->features & DASD_FEATURE_READONLY &&
1158                     rq_data_dir(req) == WRITE) {
1159                         DBF_DEV_EVENT(DBF_ERR, device,
1160                                       "Rejecting write request %p",
1161                                       req);
1162                         blkdev_dequeue_request(req);
1163                         dasd_end_request(req, 0);
1164                         continue;
1165                 }
1166                 if (device->stopped & DASD_STOPPED_DC_EIO) {
1167                         blkdev_dequeue_request(req);
1168                         dasd_end_request(req, 0);
1169                         continue;
1170                 }
1171                 cqr = device->discipline->build_cp(device, req);
1172                 if (IS_ERR(cqr)) {
1173                         if (PTR_ERR(cqr) == -ENOMEM)
1174                                 break;  /* terminate request queue loop */
1175                         DBF_DEV_EVENT(DBF_ERR, device,
1176                                       "CCW creation failed (rc=%ld) "
1177                                       "on request %p",
1178                                       PTR_ERR(cqr), req);
1179                         blkdev_dequeue_request(req);
1180                         dasd_end_request(req, 0);
1181                         continue;
1182                 }
1183                 cqr->callback = dasd_end_request_cb;
1184                 cqr->callback_data = (void *) req;
1185                 cqr->status = DASD_CQR_QUEUED;
1186                 blkdev_dequeue_request(req);
1187                 list_add_tail(&cqr->list, &device->ccw_queue);
1188                 dasd_profile_start(device, cqr, req);
1189                 nr_queued++;
1190         }
1191 }
1192
1193 /*
1194  * Take a look at the first request on the ccw queue and check
1195  * if it reached its expire time. If so, terminate the IO.
1196  */
1197 static inline void
1198 __dasd_check_expire(struct dasd_device * device)
1199 {
1200         struct dasd_ccw_req *cqr;
1201
1202         if (list_empty(&device->ccw_queue))
1203                 return;
1204         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1205         if (cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) {
1206                 if (time_after_eq(jiffies, cqr->expires + cqr->starttime)) {
1207                         if (device->discipline->term_IO(cqr) != 0)
1208                                 /* Hmpf, try again in 1/10 sec */
1209                                 dasd_set_timer(device, 10);
1210                 }
1211         }
1212 }
1213
1214 /*
1215  * Take a look at the first request on the ccw queue and check
1216  * if it needs to be started.
1217  */
1218 static inline void
1219 __dasd_start_head(struct dasd_device * device)
1220 {
1221         struct dasd_ccw_req *cqr;
1222         int rc;
1223
1224         if (list_empty(&device->ccw_queue))
1225                 return;
1226         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1227         if ((cqr->status == DASD_CQR_QUEUED) &&
1228             (!device->stopped)) {
1229                 /* try to start the first I/O that can be started */
1230                 rc = device->discipline->start_IO(cqr);
1231                 if (rc == 0)
1232                         dasd_set_timer(device, cqr->expires);
1233                 else if (rc == -EACCES) {
1234                         dasd_schedule_bh(device);
1235                 } else
1236                         /* Hmpf, try again in 1/2 sec */
1237                         dasd_set_timer(device, 50);
1238         }
1239 }
1240
1241 /*
1242  * Remove requests from the ccw queue.
1243  */
1244 static void
1245 dasd_flush_ccw_queue(struct dasd_device * device, int all)
1246 {
1247         struct list_head flush_queue;
1248         struct list_head *l, *n;
1249         struct dasd_ccw_req *cqr;
1250
1251         INIT_LIST_HEAD(&flush_queue);
1252         spin_lock_irq(get_ccwdev_lock(device->cdev));
1253         list_for_each_safe(l, n, &device->ccw_queue) {
1254                 cqr = list_entry(l, struct dasd_ccw_req, list);
1255                 /* Flush all request or only block device requests? */
1256                 if (all == 0 && cqr->callback == dasd_end_request_cb)
1257                         continue;
1258                 if (cqr->status == DASD_CQR_IN_IO)
1259                         device->discipline->term_IO(cqr);
1260                 if (cqr->status != DASD_CQR_DONE ||
1261                     cqr->status != DASD_CQR_FAILED) {
1262                         cqr->status = DASD_CQR_FAILED;
1263                         cqr->stopclk = get_clock();
1264                 }
1265                 /* Process finished ERP request. */
1266                 if (cqr->refers) {
1267                         __dasd_process_erp(device, cqr);
1268                         continue;
1269                 }
1270                 /* Rechain request on device request queue */
1271                 cqr->endclk = get_clock();
1272                 list_move_tail(&cqr->list, &flush_queue);
1273         }
1274         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1275         /* Now call the callback function of flushed requests */
1276         list_for_each_safe(l, n, &flush_queue) {
1277                 cqr = list_entry(l, struct dasd_ccw_req, list);
1278                 if (cqr->callback != NULL)
1279                         (cqr->callback)(cqr, cqr->callback_data);
1280         }
1281 }
1282
1283 /*
1284  * Acquire the device lock and process queues for the device.
1285  */
1286 static void
1287 dasd_tasklet(struct dasd_device * device)
1288 {
1289         struct list_head final_queue;
1290         struct list_head *l, *n;
1291         struct dasd_ccw_req *cqr;
1292
1293         atomic_set (&device->tasklet_scheduled, 0);
1294         INIT_LIST_HEAD(&final_queue);
1295         spin_lock_irq(get_ccwdev_lock(device->cdev));
1296         /* Check expire time of first request on the ccw queue. */
1297         __dasd_check_expire(device);
1298         /* Finish off requests on ccw queue */
1299         __dasd_process_ccw_queue(device, &final_queue);
1300         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1301         /* Now call the callback function of requests with final status */
1302         list_for_each_safe(l, n, &final_queue) {
1303                 cqr = list_entry(l, struct dasd_ccw_req, list);
1304                 list_del(&cqr->list);
1305                 if (cqr->callback != NULL)
1306                         (cqr->callback)(cqr, cqr->callback_data);
1307         }
1308         spin_lock_irq(&device->request_queue_lock);
1309         spin_lock(get_ccwdev_lock(device->cdev));
1310         /* Get new request from the block device request queue */
1311         __dasd_process_blk_queue(device);
1312         /* Now check if the head of the ccw queue needs to be started. */
1313         __dasd_start_head(device);
1314         spin_unlock(get_ccwdev_lock(device->cdev));
1315         spin_unlock_irq(&device->request_queue_lock);
1316         dasd_put_device(device);
1317 }
1318
1319 /*
1320  * Schedules a call to dasd_tasklet over the device tasklet.
1321  */
1322 void
1323 dasd_schedule_bh(struct dasd_device * device)
1324 {
1325         /* Protect against rescheduling. */
1326         if (atomic_compare_and_swap (0, 1, &device->tasklet_scheduled))
1327                 return;
1328         dasd_get_device(device);
1329         tasklet_hi_schedule(&device->tasklet);
1330 }
1331
1332 /*
1333  * Queue a request to the head of the ccw_queue. Start the I/O if
1334  * possible.
1335  */
1336 void
1337 dasd_add_request_head(struct dasd_ccw_req *req)
1338 {
1339         struct dasd_device *device;
1340         unsigned long flags;
1341
1342         device = req->device;
1343         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1344         req->status = DASD_CQR_QUEUED;
1345         req->device = device;
1346         list_add(&req->list, &device->ccw_queue);
1347         /* let the bh start the request to keep them in order */
1348         dasd_schedule_bh(device);
1349         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1350 }
1351
1352 /*
1353  * Queue a request to the tail of the ccw_queue. Start the I/O if
1354  * possible.
1355  */
1356 void
1357 dasd_add_request_tail(struct dasd_ccw_req *req)
1358 {
1359         struct dasd_device *device;
1360         unsigned long flags;
1361
1362         device = req->device;
1363         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1364         req->status = DASD_CQR_QUEUED;
1365         req->device = device;
1366         list_add_tail(&req->list, &device->ccw_queue);
1367         /* let the bh start the request to keep them in order */
1368         dasd_schedule_bh(device);
1369         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1370 }
1371
1372 /*
1373  * Wakeup callback.
1374  */
1375 static void
1376 dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
1377 {
1378         wake_up((wait_queue_head_t *) data);
1379 }
1380
1381 static inline int
1382 _wait_for_wakeup(struct dasd_ccw_req *cqr)
1383 {
1384         struct dasd_device *device;
1385         int rc;
1386
1387         device = cqr->device;
1388         spin_lock_irq(get_ccwdev_lock(device->cdev));
1389         rc = cqr->status == DASD_CQR_DONE || cqr->status == DASD_CQR_FAILED;
1390         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1391         return rc;
1392 }
1393
1394 /*
1395  * Attempts to start a special ccw queue and waits for its completion.
1396  */
1397 int
1398 dasd_sleep_on(struct dasd_ccw_req * cqr)
1399 {
1400         wait_queue_head_t wait_q;
1401         struct dasd_device *device;
1402         int rc;
1403
1404         device = cqr->device;
1405         spin_lock_irq(get_ccwdev_lock(device->cdev));
1406
1407         init_waitqueue_head (&wait_q);
1408         cqr->callback = dasd_wakeup_cb;
1409         cqr->callback_data = (void *) &wait_q;
1410         cqr->status = DASD_CQR_QUEUED;
1411         list_add_tail(&cqr->list, &device->ccw_queue);
1412
1413         /* let the bh start the request to keep them in order */
1414         dasd_schedule_bh(device);
1415
1416         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1417
1418         wait_event(wait_q, _wait_for_wakeup(cqr));
1419
1420         /* Request status is either done or failed. */
1421         rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1422         return rc;
1423 }
1424
1425 /*
1426  * Attempts to start a special ccw queue and wait interruptible
1427  * for its completion.
1428  */
1429 int
1430 dasd_sleep_on_interruptible(struct dasd_ccw_req * cqr)
1431 {
1432         wait_queue_head_t wait_q;
1433         struct dasd_device *device;
1434         int rc, finished;
1435
1436         device = cqr->device;
1437         spin_lock_irq(get_ccwdev_lock(device->cdev));
1438
1439         init_waitqueue_head (&wait_q);
1440         cqr->callback = dasd_wakeup_cb;
1441         cqr->callback_data = (void *) &wait_q;
1442         cqr->status = DASD_CQR_QUEUED;
1443         list_add_tail(&cqr->list, &device->ccw_queue);
1444
1445         /* let the bh start the request to keep them in order */
1446         dasd_schedule_bh(device);
1447         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1448
1449         finished = 0;
1450         while (!finished) {
1451                 rc = wait_event_interruptible(wait_q, _wait_for_wakeup(cqr));
1452                 if (rc != -ERESTARTSYS) {
1453                         /* Request status is either done or failed. */
1454                         rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1455                         break;
1456                 }
1457                 spin_lock_irq(get_ccwdev_lock(device->cdev));
1458                 if (cqr->status == DASD_CQR_IN_IO &&
1459                     device->discipline->term_IO(cqr) == 0) {
1460                         list_del(&cqr->list);
1461                         finished = 1;
1462                 }
1463                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1464         }
1465         return rc;
1466 }
1467
1468 /*
1469  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
1470  * for eckd devices) the currently running request has to be terminated
1471  * and be put back to status queued, before the special request is added
1472  * to the head of the queue. Then the special request is waited on normally.
1473  */
1474 static inline int
1475 _dasd_term_running_cqr(struct dasd_device *device)
1476 {
1477         struct dasd_ccw_req *cqr;
1478         int rc;
1479
1480         if (list_empty(&device->ccw_queue))
1481                 return 0;
1482         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1483         rc = device->discipline->term_IO(cqr);
1484         if (rc == 0) {
1485                 /* termination successful */
1486                 cqr->status = DASD_CQR_QUEUED;
1487                 cqr->startclk = cqr->stopclk = 0;
1488                 cqr->starttime = 0;
1489         }
1490         return rc;
1491 }
1492
1493 int
1494 dasd_sleep_on_immediatly(struct dasd_ccw_req * cqr)
1495 {
1496         wait_queue_head_t wait_q;
1497         struct dasd_device *device;
1498         int rc;
1499
1500         device = cqr->device;
1501         spin_lock_irq(get_ccwdev_lock(device->cdev));
1502         rc = _dasd_term_running_cqr(device);
1503         if (rc) {
1504                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1505                 return rc;
1506         }
1507
1508         init_waitqueue_head (&wait_q);
1509         cqr->callback = dasd_wakeup_cb;
1510         cqr->callback_data = (void *) &wait_q;
1511         cqr->status = DASD_CQR_QUEUED;
1512         list_add(&cqr->list, &device->ccw_queue);
1513
1514         /* let the bh start the request to keep them in order */
1515         dasd_schedule_bh(device);
1516
1517         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1518
1519         wait_event(wait_q, _wait_for_wakeup(cqr));
1520
1521         /* Request status is either done or failed. */
1522         rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1523         return rc;
1524 }
1525
1526 /*
1527  * Cancels a request that was started with dasd_sleep_on_req.
1528  * This is useful to timeout requests. The request will be
1529  * terminated if it is currently in i/o.
1530  * Returns 1 if the request has been terminated.
1531  */
1532 int
1533 dasd_cancel_req(struct dasd_ccw_req *cqr)
1534 {
1535         struct dasd_device *device = cqr->device;
1536         unsigned long flags;
1537         int rc;
1538
1539         rc = 0;
1540         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1541         switch (cqr->status) {
1542         case DASD_CQR_QUEUED:
1543                 /* request was not started - just set to failed */
1544                 cqr->status = DASD_CQR_FAILED;
1545                 break;
1546         case DASD_CQR_IN_IO:
1547                 /* request in IO - terminate IO and release again */
1548                 if (device->discipline->term_IO(cqr) != 0)
1549                         /* what to do if unable to terminate ??????
1550                            e.g. not _IN_IO */
1551                         cqr->status = DASD_CQR_FAILED;
1552                 cqr->stopclk = get_clock();
1553                 rc = 1;
1554                 break;
1555         case DASD_CQR_DONE:
1556         case DASD_CQR_FAILED:
1557                 /* already finished - do nothing */
1558                 break;
1559         default:
1560                 DEV_MESSAGE(KERN_ALERT, device,
1561                             "invalid status %02x in request",
1562                             cqr->status);
1563                 BUG();
1564
1565         }
1566         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1567         dasd_schedule_bh(device);
1568         return rc;
1569 }
1570
1571 /*
1572  * SECTION: Block device operations (request queue, partitions, open, release).
1573  */
1574
1575 /*
1576  * Dasd request queue function. Called from ll_rw_blk.c
1577  */
1578 static void
1579 do_dasd_request(request_queue_t * queue)
1580 {
1581         struct dasd_device *device;
1582
1583         device = (struct dasd_device *) queue->queuedata;
1584         spin_lock(get_ccwdev_lock(device->cdev));
1585         /* Get new request from the block device request queue */
1586         __dasd_process_blk_queue(device);
1587         /* Now check if the head of the ccw queue needs to be started. */
1588         __dasd_start_head(device);
1589         spin_unlock(get_ccwdev_lock(device->cdev));
1590 }
1591
1592 /*
1593  * Allocate and initialize request queue and default I/O scheduler.
1594  */
1595 static int
1596 dasd_alloc_queue(struct dasd_device * device)
1597 {
1598         int rc;
1599
1600         device->request_queue = blk_init_queue(do_dasd_request,
1601                                                &device->request_queue_lock);
1602         if (device->request_queue == NULL)
1603                 return -ENOMEM;
1604
1605         device->request_queue->queuedata = device;
1606
1607         elevator_exit(device->request_queue->elevator);
1608         rc = elevator_init(device->request_queue, "deadline");
1609         if (rc) {
1610                 blk_cleanup_queue(device->request_queue);
1611                 return rc;
1612         }
1613         return 0;
1614 }
1615
1616 /*
1617  * Allocate and initialize request queue.
1618  */
1619 static void
1620 dasd_setup_queue(struct dasd_device * device)
1621 {
1622         int max;
1623
1624         blk_queue_hardsect_size(device->request_queue, device->bp_block);
1625         max = device->discipline->max_blocks << device->s2b_shift;
1626         blk_queue_max_sectors(device->request_queue, max);
1627         blk_queue_max_phys_segments(device->request_queue, -1L);
1628         blk_queue_max_hw_segments(device->request_queue, -1L);
1629         blk_queue_max_segment_size(device->request_queue, -1L);
1630         blk_queue_segment_boundary(device->request_queue, -1L);
1631         blk_queue_ordered(device->request_queue, 1);
1632 }
1633
1634 /*
1635  * Deactivate and free request queue.
1636  */
1637 static void
1638 dasd_free_queue(struct dasd_device * device)
1639 {
1640         if (device->request_queue) {
1641                 blk_cleanup_queue(device->request_queue);
1642                 device->request_queue = NULL;
1643         }
1644 }
1645
1646 /*
1647  * Flush request on the request queue.
1648  */
1649 static void
1650 dasd_flush_request_queue(struct dasd_device * device)
1651 {
1652         struct request *req;
1653
1654         if (!device->request_queue)
1655                 return;
1656
1657         spin_lock_irq(&device->request_queue_lock);
1658         while (!list_empty(&device->request_queue->queue_head)) {
1659                 req = elv_next_request(device->request_queue);
1660                 if (req == NULL)
1661                         break;
1662                 dasd_end_request(req, 0);
1663                 blkdev_dequeue_request(req);
1664         }
1665         spin_unlock_irq(&device->request_queue_lock);
1666 }
1667
1668 static int
1669 dasd_open(struct inode *inp, struct file *filp)
1670 {
1671         struct gendisk *disk = inp->i_bdev->bd_disk;
1672         struct dasd_device *device = disk->private_data;
1673         int rc;
1674
1675         atomic_inc(&device->open_count);
1676         if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1677                 rc = -ENODEV;
1678                 goto unlock;
1679         }
1680
1681         if (!try_module_get(device->discipline->owner)) {
1682                 rc = -EINVAL;
1683                 goto unlock;
1684         }
1685
1686         if (dasd_probeonly) {
1687                 DEV_MESSAGE(KERN_INFO, device, "%s",
1688                             "No access to device due to probeonly mode");
1689                 rc = -EPERM;
1690                 goto out;
1691         }
1692
1693         if (device->state < DASD_STATE_BASIC) {
1694                 DBF_DEV_EVENT(DBF_ERR, device, " %s",
1695                               " Cannot open unrecognized device");
1696                 rc = -ENODEV;
1697                 goto out;
1698         }
1699
1700         return 0;
1701
1702 out:
1703         module_put(device->discipline->owner);
1704 unlock:
1705         atomic_dec(&device->open_count);
1706         return rc;
1707 }
1708
1709 static int
1710 dasd_release(struct inode *inp, struct file *filp)
1711 {
1712         struct gendisk *disk = inp->i_bdev->bd_disk;
1713         struct dasd_device *device = disk->private_data;
1714
1715         atomic_dec(&device->open_count);
1716         module_put(device->discipline->owner);
1717         return 0;
1718 }
1719
1720 struct block_device_operations
1721 dasd_device_operations = {
1722         .owner          = THIS_MODULE,
1723         .open           = dasd_open,
1724         .release        = dasd_release,
1725         .ioctl          = dasd_ioctl,
1726 };
1727
1728
1729 static void
1730 dasd_exit(void)
1731 {
1732 #ifdef CONFIG_PROC_FS
1733         dasd_proc_exit();
1734 #endif
1735         dasd_ioctl_exit();
1736         if (dasd_page_cache != NULL) {
1737                 kmem_cache_destroy(dasd_page_cache);
1738                 dasd_page_cache = NULL;
1739         }
1740         dasd_gendisk_exit();
1741         dasd_devmap_exit();
1742         devfs_remove("dasd");
1743         if (dasd_debug_area != NULL) {
1744                 debug_unregister(dasd_debug_area);
1745                 dasd_debug_area = NULL;
1746         }
1747 }
1748
1749 /*
1750  * SECTION: common functions for ccw_driver use
1751  */
1752
1753 /* initial attempt at a probe function. this can be simplified once
1754  * the other detection code is gone */
1755 int
1756 dasd_generic_probe (struct ccw_device *cdev,
1757                     struct dasd_discipline *discipline)
1758 {
1759         int ret;
1760
1761         ret = dasd_add_sysfs_files(cdev);
1762         if (ret) {
1763                 printk(KERN_WARNING
1764                        "dasd_generic_probe: could not add sysfs entries "
1765                        "for %s\n", cdev->dev.bus_id);
1766         } else {
1767                 cdev->handler = &dasd_int_handler;
1768         }
1769
1770         return ret;
1771 }
1772
1773 /* this will one day be called from a global not_oper handler.
1774  * It is also used by driver_unregister during module unload */
1775 void
1776 dasd_generic_remove (struct ccw_device *cdev)
1777 {
1778         struct dasd_device *device;
1779
1780         cdev->handler = NULL;
1781
1782         dasd_remove_sysfs_files(cdev);
1783         device = dasd_device_from_cdev(cdev);
1784         if (IS_ERR(device))
1785                 return;
1786         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1787                 /* Already doing offline processing */
1788                 dasd_put_device(device);
1789                 return;
1790         }
1791         /*
1792          * This device is removed unconditionally. Set offline
1793          * flag to prevent dasd_open from opening it while it is
1794          * no quite down yet.
1795          */
1796         dasd_set_target_state(device, DASD_STATE_NEW);
1797         /* dasd_delete_device destroys the device reference. */
1798         dasd_delete_device(device);
1799 }
1800
1801 /* activate a device. This is called from dasd_{eckd,fba}_probe() when either
1802  * the device is detected for the first time and is supposed to be used
1803  * or the user has started activation through sysfs */
1804 int
1805 dasd_generic_set_online (struct ccw_device *cdev,
1806                          struct dasd_discipline *discipline)
1807
1808 {
1809         struct dasd_device *device;
1810         int rc;
1811
1812         device = dasd_create_device(cdev);
1813         if (IS_ERR(device))
1814                 return PTR_ERR(device);
1815
1816         if (device->features & DASD_FEATURE_USEDIAG) {
1817                 if (!dasd_diag_discipline_pointer) {
1818                         printk (KERN_WARNING
1819                                 "dasd_generic couldn't online device %s "
1820                                 "- discipline DIAG not available\n",
1821                                 cdev->dev.bus_id);
1822                         dasd_delete_device(device);
1823                         return -ENODEV;
1824                 }
1825                 discipline = dasd_diag_discipline_pointer;
1826         }
1827         device->discipline = discipline;
1828
1829         rc = discipline->check_device(device);
1830         if (rc) {
1831                 printk (KERN_WARNING
1832                         "dasd_generic couldn't online device %s "
1833                         "with discipline %s rc=%i\n",
1834                         cdev->dev.bus_id, discipline->name, rc);
1835                 dasd_delete_device(device);
1836                 return rc;
1837         }
1838
1839         dasd_set_target_state(device, DASD_STATE_ONLINE);
1840         if (device->state <= DASD_STATE_KNOWN) {
1841                 printk (KERN_WARNING
1842                         "dasd_generic discipline not found for %s\n",
1843                         cdev->dev.bus_id);
1844                 rc = -ENODEV;
1845                 dasd_set_target_state(device, DASD_STATE_NEW);
1846                 dasd_delete_device(device);
1847         } else
1848                 pr_debug("dasd_generic device %s found\n",
1849                                 cdev->dev.bus_id);
1850
1851         /* FIXME: we have to wait for the root device but we don't want
1852          * to wait for each single device but for all at once. */
1853         wait_event(dasd_init_waitq, _wait_for_device(device));
1854
1855         dasd_put_device(device);
1856
1857         return rc;
1858 }
1859
1860 int
1861 dasd_generic_set_offline (struct ccw_device *cdev)
1862 {
1863         struct dasd_device *device;
1864         int max_count;
1865
1866         device = dasd_device_from_cdev(cdev);
1867         if (IS_ERR(device))
1868                 return PTR_ERR(device);
1869         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1870                 /* Already doing offline processing */
1871                 dasd_put_device(device);
1872                 return 0;
1873         }
1874         /*
1875          * We must make sure that this device is currently not in use.
1876          * The open_count is increased for every opener, that includes
1877          * the blkdev_get in dasd_scan_partitions. We are only interested
1878          * in the other openers.
1879          */
1880         max_count = device->bdev ? 0 : -1;
1881         if (atomic_read(&device->open_count) > max_count) {
1882                 printk (KERN_WARNING "Can't offline dasd device with open"
1883                         " count = %i.\n",
1884                         atomic_read(&device->open_count));
1885                 clear_bit(DASD_FLAG_OFFLINE, &device->flags);
1886                 dasd_put_device(device);
1887                 return -EBUSY;
1888         }
1889         dasd_set_target_state(device, DASD_STATE_NEW);
1890         /* dasd_delete_device destroys the device reference. */
1891         dasd_delete_device(device);
1892
1893         return 0;
1894 }
1895
1896 int
1897 dasd_generic_notify(struct ccw_device *cdev, int event)
1898 {
1899         struct dasd_device *device;
1900         struct dasd_ccw_req *cqr;
1901         unsigned long flags;
1902         int ret;
1903
1904         device = dasd_device_from_cdev(cdev);
1905         if (IS_ERR(device))
1906                 return 0;
1907         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1908         ret = 0;
1909         switch (event) {
1910         case CIO_GONE:
1911         case CIO_NO_PATH:
1912                 if (device->state < DASD_STATE_BASIC)
1913                         break;
1914                 /* Device is active. We want to keep it. */
1915                 if (test_bit(DASD_FLAG_DSC_ERROR, &device->flags)) {
1916                         list_for_each_entry(cqr, &device->ccw_queue, list)
1917                                 if (cqr->status == DASD_CQR_IN_IO)
1918                                         cqr->status = DASD_CQR_FAILED;
1919                         device->stopped |= DASD_STOPPED_DC_EIO;
1920                         dasd_schedule_bh(device);
1921                 } else {
1922                         list_for_each_entry(cqr, &device->ccw_queue, list)
1923                                 if (cqr->status == DASD_CQR_IN_IO) {
1924                                         cqr->status = DASD_CQR_QUEUED;
1925                                         cqr->retries++;
1926                                 }
1927                         device->stopped |= DASD_STOPPED_DC_WAIT;
1928                         dasd_set_timer(device, 0);
1929                 }
1930                 ret = 1;
1931                 break;
1932         case CIO_OPER:
1933                 /* FIXME: add a sanity check. */
1934                 device->stopped &= ~(DASD_STOPPED_DC_WAIT|DASD_STOPPED_DC_EIO);
1935                 dasd_schedule_bh(device);
1936                 ret = 1;
1937                 break;
1938         }
1939         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1940         dasd_put_device(device);
1941         return ret;
1942 }
1943
1944 /*
1945  * Automatically online either all dasd devices (dasd_autodetect) or
1946  * all devices specified with dasd= parameters.
1947  */
1948 static int
1949 __dasd_auto_online(struct device *dev, void *data)
1950 {
1951         struct ccw_device *cdev;
1952
1953         cdev = to_ccwdev(dev);
1954         if (dasd_autodetect || dasd_busid_known(cdev->dev.bus_id) == 0)
1955                 ccw_device_set_online(cdev);
1956         return 0;
1957 }
1958
1959 void
1960 dasd_generic_auto_online (struct ccw_driver *dasd_discipline_driver)
1961 {
1962         struct device_driver *drv;
1963
1964         drv = get_driver(&dasd_discipline_driver->driver);
1965         driver_for_each_device(drv, NULL, NULL, __dasd_auto_online);
1966         put_driver(drv);
1967 }
1968
1969 static int __init
1970 dasd_init(void)
1971 {
1972         int rc;
1973
1974         init_waitqueue_head(&dasd_init_waitq);
1975
1976         /* register 'common' DASD debug area, used for all DBF_XXX calls */
1977         dasd_debug_area = debug_register("dasd", 1, 2, 8 * sizeof (long));
1978         if (dasd_debug_area == NULL) {
1979                 rc = -ENOMEM;
1980                 goto failed;
1981         }
1982         debug_register_view(dasd_debug_area, &debug_sprintf_view);
1983         debug_set_level(dasd_debug_area, DBF_EMERG);
1984
1985         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
1986
1987         dasd_diag_discipline_pointer = NULL;
1988
1989         rc = devfs_mk_dir("dasd");
1990         if (rc)
1991                 goto failed;
1992         rc = dasd_devmap_init();
1993         if (rc)
1994                 goto failed;
1995         rc = dasd_gendisk_init();
1996         if (rc)
1997                 goto failed;
1998         rc = dasd_parse();
1999         if (rc)
2000                 goto failed;
2001         rc = dasd_ioctl_init();
2002         if (rc)
2003                 goto failed;
2004 #ifdef CONFIG_PROC_FS
2005         rc = dasd_proc_init();
2006         if (rc)
2007                 goto failed;
2008 #endif
2009
2010         return 0;
2011 failed:
2012         MESSAGE(KERN_INFO, "%s", "initialization not performed due to errors");
2013         dasd_exit();
2014         return rc;
2015 }
2016
2017 module_init(dasd_init);
2018 module_exit(dasd_exit);
2019
2020 EXPORT_SYMBOL(dasd_debug_area);
2021 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
2022
2023 EXPORT_SYMBOL(dasd_add_request_head);
2024 EXPORT_SYMBOL(dasd_add_request_tail);
2025 EXPORT_SYMBOL(dasd_cancel_req);
2026 EXPORT_SYMBOL(dasd_clear_timer);
2027 EXPORT_SYMBOL(dasd_enable_device);
2028 EXPORT_SYMBOL(dasd_int_handler);
2029 EXPORT_SYMBOL(dasd_kfree_request);
2030 EXPORT_SYMBOL(dasd_kick_device);
2031 EXPORT_SYMBOL(dasd_kmalloc_request);
2032 EXPORT_SYMBOL(dasd_schedule_bh);
2033 EXPORT_SYMBOL(dasd_set_target_state);
2034 EXPORT_SYMBOL(dasd_set_timer);
2035 EXPORT_SYMBOL(dasd_sfree_request);
2036 EXPORT_SYMBOL(dasd_sleep_on);
2037 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2038 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2039 EXPORT_SYMBOL(dasd_smalloc_request);
2040 EXPORT_SYMBOL(dasd_start_IO);
2041 EXPORT_SYMBOL(dasd_term_IO);
2042
2043 EXPORT_SYMBOL_GPL(dasd_generic_probe);
2044 EXPORT_SYMBOL_GPL(dasd_generic_remove);
2045 EXPORT_SYMBOL_GPL(dasd_generic_notify);
2046 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
2047 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
2048 EXPORT_SYMBOL_GPL(dasd_generic_auto_online);
2049
2050 /*
2051  * Overrides for Emacs so that we follow Linus's tabbing style.
2052  * Emacs will notice this stuff at the end of the file and automatically
2053  * adjust the settings for this buffer only.  This must remain at the end
2054  * of the file.
2055  * ---------------------------------------------------------------------------
2056  * Local variables:
2057  * c-indent-level: 4
2058  * c-brace-imaginary-offset: 0
2059  * c-brace-offset: -4
2060  * c-argdecl-indent: 4
2061  * c-label-offset: -4
2062  * c-continued-statement-offset: 4
2063  * c-continued-brace-offset: 0
2064  * indent-tabs-mode: 1
2065  * tab-width: 8
2066  * End:
2067  */