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  */
  11
  12 #include <linux/kmod.h>
  13 #include <linux/init.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/ctype.h>
  16 #include <linux/major.h>
  17 #include <linux/slab.h>
  18 #include <linux/buffer_head.h>
  19 #include <linux/hdreg.h>
  20
  21 #include <asm/ccwdev.h>
  22 #include <asm/ebcdic.h>
  23 #include <asm/idals.h>
  24 #include <asm/todclk.h>
  25
  26 /* This is ugly... */
  27 #define PRINTK_HEADER "dasd:"
  28
  29 #include "dasd_int.h"
  30 /*
  31  * SECTION: Constant definitions to be used within this file
  32  */
  33 #define DASD_CHANQ_MAX_SIZE 4
  34
  35 /*
  36  * SECTION: exported variables of dasd.c
  37  */
  38 debug_info_t *dasd_debug_area;
  39 struct dasd_discipline *dasd_diag_discipline_pointer;
  40
  41 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
  42 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
  43                    " Copyright 2000 IBM Corporation");
  44 MODULE_SUPPORTED_DEVICE("dasd");
  45 MODULE_LICENSE("GPL");
  46
  47 /*
  48  * SECTION: prototypes for static functions of dasd.c
  49  */
  50 static int  dasd_alloc_queue(struct dasd_device * device);
  51 static void dasd_setup_queue(struct dasd_device * device);
  52 static void dasd_free_queue(struct dasd_device * device);
  53 static void dasd_flush_request_queue(struct dasd_device *);
  54 static void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
  55 static void dasd_flush_ccw_queue(struct dasd_device *, int);
  56 static void dasd_tasklet(struct dasd_device *);
  57 static void do_kick_device(void *data);
  58
  59 /*
  60  * SECTION: Operations on the device structure.
  61  */
  62 static wait_queue_head_t dasd_init_waitq;
  63
  64 /*
  65  * Allocate memory for a new device structure.
  66  */
  67 struct dasd_device *
  68 dasd_alloc_device(void)
  69 {
  70         struct dasd_device *device;
  71
  72         device = kzalloc(sizeof (struct dasd_device), GFP_ATOMIC);
  73         if (device == NULL)
  74                 return ERR_PTR(-ENOMEM);
  75         /* open_count = 0 means device online but not in use */
  76         atomic_set(&device->open_count, -1);
  77
  78         /* Get two pages for normal block device operations. */
  79         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
  80         if (device->ccw_mem == NULL) {
  81                 kfree(device);
  82                 return ERR_PTR(-ENOMEM);
  83         }
  84         /* Get one page for error recovery. */
  85         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
  86         if (device->erp_mem == NULL) {
  87                 free_pages((unsigned long) device->ccw_mem, 1);
  88                 kfree(device);
  89                 return ERR_PTR(-ENOMEM);
  90         }
  91
  92         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
  93         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
  94         spin_lock_init(&device->mem_lock);
  95         spin_lock_init(&device->request_queue_lock);
  96         atomic_set (&device->tasklet_scheduled, 0);
  97         tasklet_init(&device->tasklet,
  98                      (void (*)(unsigned long)) dasd_tasklet,
  99                      (unsigned long) device);
 100         INIT_LIST_HEAD(&device->ccw_queue);
 101         init_timer(&device->timer);
 102         INIT_WORK(&device->kick_work, do_kick_device, device);
 103         device->state = DASD_STATE_NEW;
 104         device->target = DASD_STATE_NEW;
 105
 106         return device;
 107 }
 108
 109 /*
 110  * Free memory of a device structure.
 111  */
 112 void
 113 dasd_free_device(struct dasd_device *device)
 114 {
 115         kfree(device->private);
 116         free_page((unsigned long) device->erp_mem);
 117         free_pages((unsigned long) device->ccw_mem, 1);
 118         kfree(device);
 119 }
 120
 121 /*
 122  * Make a new device known to the system.
 123  */
 124 static inline int
 125 dasd_state_new_to_known(struct dasd_device *device)
 126 {
 127         int rc;
 128
 129         /*
 130          * As long as the device is not in state DASD_STATE_NEW we want to
 131          * keep the reference count > 0.
 132          */
 133         dasd_get_device(device);
 134
 135         rc = dasd_alloc_queue(device);
 136         if (rc) {
 137                 dasd_put_device(device);
 138                 return rc;
 139         }
 140
 141         device->state = DASD_STATE_KNOWN;
 142         return 0;
 143 }
 144
 145 /*
 146  * Let the system forget about a device.
 147  */
 148 static inline void
 149 dasd_state_known_to_new(struct dasd_device * device)
 150 {
 151         /* Disable extended error reporting for this device. */
 152         dasd_eer_disable(device);
 153         /* Forget the discipline information. */
 154         if (device->discipline)
 155                 module_put(device->discipline->owner);
 156         device->discipline = NULL;
 157         if (device->base_discipline)
 158                 module_put(device->base_discipline->owner);
 159         device->base_discipline = NULL;
 160         device->state = DASD_STATE_NEW;
 161
 162         dasd_free_queue(device);
 163
 164         /* Give up reference we took in dasd_state_new_to_known. */
 165         dasd_put_device(device);
 166 }
 167
 168 /*
 169  * Request the irq line for the device.
 170  */
 171 static inline int
 172 dasd_state_known_to_basic(struct dasd_device * device)
 173 {
 174         int rc;
 175
 176         /* Allocate and register gendisk structure. */
 177         rc = dasd_gendisk_alloc(device);
 178         if (rc)
 179                 return rc;
 180
 181         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 182         device->debug_area = debug_register(device->cdev->dev.bus_id, 1, 2,
 183                                             8 * sizeof (long));
 184         debug_register_view(device->debug_area, &debug_sprintf_view);
 185         debug_set_level(device->debug_area, DBF_EMERG);
 186         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 187
 188         device->state = DASD_STATE_BASIC;
 189         return 0;
 190 }
 191
 192 /*
 193  * Release the irq line for the device. Terminate any running i/o.
 194  */
 195 static inline void
 196 dasd_state_basic_to_known(struct dasd_device * device)
 197 {
 198         dasd_gendisk_free(device);
 199         dasd_flush_ccw_queue(device, 1);
 200         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
 201         if (device->debug_area != NULL) {
 202                 debug_unregister(device->debug_area);
 203                 device->debug_area = NULL;
 204         }
 205         device->state = DASD_STATE_KNOWN;
 206 }
 207
 208 /*
 209  * Do the initial analysis. The do_analysis function may return
 210  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 211  * until the discipline decides to continue the startup sequence
 212  * by calling the function dasd_change_state. The eckd disciplines
 213  * uses this to start a ccw that detects the format. The completion
 214  * interrupt for this detection ccw uses the kernel event daemon to
 215  * trigger the call to dasd_change_state. All this is done in the
 216  * discipline code, see dasd_eckd.c.
 217  * After the analysis ccw is done (do_analysis returned 0) the block
 218  * device is setup.
 219  * In case the analysis returns an error, the device setup is stopped
 220  * (a fake disk was already added to allow formatting).
 221  */
 222 static inline int
 223 dasd_state_basic_to_ready(struct dasd_device * device)
 224 {
 225         int rc;
 226
 227         rc = 0;
 228         if (device->discipline->do_analysis != NULL)
 229                 rc = device->discipline->do_analysis(device);
 230         if (rc) {
 231                 if (rc != -EAGAIN)
 232                         device->state = DASD_STATE_UNFMT;
 233                 return rc;
 234         }
 235         /* make disk known with correct capacity */
 236         dasd_setup_queue(device);
 237         set_capacity(device->gdp, device->blocks << device->s2b_shift);
 238         device->state = DASD_STATE_READY;
 239         rc = dasd_scan_partitions(device);
 240         if (rc)
 241                 device->state = DASD_STATE_BASIC;
 242         return rc;
 243 }
 244
 245 /*
 246  * Remove device from block device layer. Destroy dirty buffers.
 247  * Forget format information. Check if the target level is basic
 248  * and if it is create fake disk for formatting.
 249  */
 250 static inline void
 251 dasd_state_ready_to_basic(struct dasd_device * device)
 252 {
 253         dasd_flush_ccw_queue(device, 0);
 254         dasd_destroy_partitions(device);
 255         dasd_flush_request_queue(device);
 256         device->blocks = 0;
 257         device->bp_block = 0;
 258         device->s2b_shift = 0;
 259         device->state = DASD_STATE_BASIC;
 260 }
 261
 262 /*
 263  * Back to basic.
 264  */
 265 static inline void
 266 dasd_state_unfmt_to_basic(struct dasd_device * device)
 267 {
 268         device->state = DASD_STATE_BASIC;
 269 }
 270
 271 /*
 272  * Make the device online and schedule the bottom half to start
 273  * the requeueing of requests from the linux request queue to the
 274  * ccw queue.
 275  */
 276 static inline int
 277 dasd_state_ready_to_online(struct dasd_device * device)
 278 {
 279         device->state = DASD_STATE_ONLINE;
 280         dasd_schedule_bh(device);
 281         return 0;
 282 }
 283
 284 /*
 285  * Stop the requeueing of requests again.
 286  */
 287 static inline void
 288 dasd_state_online_to_ready(struct dasd_device * device)
 289 {
 290         device->state = DASD_STATE_READY;
 291 }
 292
 293 /*
 294  * Device startup state changes.
 295  */
 296 static inline int
 297 dasd_increase_state(struct dasd_device *device)
 298 {
 299         int rc;
 300
 301         rc = 0;
 302         if (device->state == DASD_STATE_NEW &&
 303             device->target >= DASD_STATE_KNOWN)
 304                 rc = dasd_state_new_to_known(device);
 305
 306         if (!rc &&
 307             device->state == DASD_STATE_KNOWN &&
 308             device->target >= DASD_STATE_BASIC)
 309                 rc = dasd_state_known_to_basic(device);
 310
 311         if (!rc &&
 312             device->state == DASD_STATE_BASIC &&
 313             device->target >= DASD_STATE_READY)
 314                 rc = dasd_state_basic_to_ready(device);
 315
 316         if (!rc &&
 317             device->state == DASD_STATE_UNFMT &&
 318             device->target > DASD_STATE_UNFMT)
 319                 rc = -EPERM;
 320
 321         if (!rc &&
 322             device->state == DASD_STATE_READY &&
 323             device->target >= DASD_STATE_ONLINE)
 324                 rc = dasd_state_ready_to_online(device);
 325
 326         return rc;
 327 }
 328
 329 /*
 330  * Device shutdown state changes.
 331  */
 332 static inline int
 333 dasd_decrease_state(struct dasd_device *device)
 334 {
 335         if (device->state == DASD_STATE_ONLINE &&
 336             device->target <= DASD_STATE_READY)
 337                 dasd_state_online_to_ready(device);
 338
 339         if (device->state == DASD_STATE_READY &&
 340             device->target <= DASD_STATE_BASIC)
 341                 dasd_state_ready_to_basic(device);
 342
 343         if (device->state == DASD_STATE_UNFMT &&
 344             device->target <= DASD_STATE_BASIC)
 345                 dasd_state_unfmt_to_basic(device);
 346
 347         if (device->state == DASD_STATE_BASIC &&
 348             device->target <= DASD_STATE_KNOWN)
 349                 dasd_state_basic_to_known(device);
 350
 351         if (device->state == DASD_STATE_KNOWN &&
 352             device->target <= DASD_STATE_NEW)
 353                 dasd_state_known_to_new(device);
 354
 355         return 0;
 356 }
 357
 358 /*
 359  * This is the main startup/shutdown routine.
 360  */
 361 static void
 362 dasd_change_state(struct dasd_device *device)
 363 {
 364         int rc;
 365
 366         if (device->state == device->target)
 367                 /* Already where we want to go today... */
 368                 return;
 369         if (device->state < device->target)
 370                 rc = dasd_increase_state(device);
 371         else
 372                 rc = dasd_decrease_state(device);
 373         if (rc && rc != -EAGAIN)
 374                 device->target = device->state;
 375
 376         if (device->state == device->target)
 377                 wake_up(&dasd_init_waitq);
 378 }
 379
 380 /*
 381  * Kick starter for devices that did not complete the startup/shutdown
 382  * procedure or were sleeping because of a pending state.
 383  * dasd_kick_device will schedule a call do do_kick_device to the kernel
 384  * event daemon.
 385  */
 386 static void
 387 do_kick_device(void *data)
 388 {
 389         struct dasd_device *device;
 390
 391         device = (struct dasd_device *) data;
 392         dasd_change_state(device);
 393         dasd_schedule_bh(device);
 394         dasd_put_device(device);
 395 }
 396
 397 void
 398 dasd_kick_device(struct dasd_device *device)
 399 {
 400         dasd_get_device(device);
 401         /* queue call to dasd_kick_device to the kernel event daemon. */
 402         schedule_work(&device->kick_work);
 403 }
 404
 405 /*
 406  * Set the target state for a device and starts the state change.
 407  */
 408 void
 409 dasd_set_target_state(struct dasd_device *device, int target)
 410 {
 411         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 412         if (dasd_probeonly && target > DASD_STATE_READY)
 413                 target = DASD_STATE_READY;
 414         if (device->target != target) {
 415                 if (device->state == target)
 416                         wake_up(&dasd_init_waitq);
 417                 device->target = target;
 418         }
 419         if (device->state != device->target)
 420                 dasd_change_state(device);
 421 }
 422
 423 /*
 424  * Enable devices with device numbers in [from..to].
 425  */
 426 static inline int
 427 _wait_for_device(struct dasd_device *device)
 428 {
 429         return (device->state == device->target);
 430 }
 431
 432 void
 433 dasd_enable_device(struct dasd_device *device)
 434 {
 435         dasd_set_target_state(device, DASD_STATE_ONLINE);
 436         if (device->state <= DASD_STATE_KNOWN)
 437                 /* No discipline for device found. */
 438                 dasd_set_target_state(device, DASD_STATE_NEW);
 439         /* Now wait for the devices to come up. */
 440         wait_event(dasd_init_waitq, _wait_for_device(device));
 441 }
 442
 443 /*
 444  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 445  */
 446 #ifdef CONFIG_DASD_PROFILE
 447
 448 struct dasd_profile_info_t dasd_global_profile;
 449 unsigned int dasd_profile_level = DASD_PROFILE_OFF;
 450
 451 /*
 452  * Increments counter in global and local profiling structures.
 453  */
 454 #define dasd_profile_counter(value, counter, device) \
 455 { \
 456         int index; \
 457         for (index = 0; index < 31 && value >> (2+index); index++); \
 458         dasd_global_profile.counter[index]++; \
 459         device->profile.counter[index]++; \
 460 }
 461
 462 /*
 463  * Add profiling information for cqr before execution.
 464  */
 465 static inline void
 466 dasd_profile_start(struct dasd_device *device, struct dasd_ccw_req * cqr,
 467                    struct request *req)
 468 {
 469         struct list_head *l;
 470         unsigned int counter;
 471
 472         if (dasd_profile_level != DASD_PROFILE_ON)
 473                 return;
 474
 475         /* count the length of the chanq for statistics */
 476         counter = 0;
 477         list_for_each(l, &device->ccw_queue)
 478                 if (++counter >= 31)
 479                         break;
 480         dasd_global_profile.dasd_io_nr_req[counter]++;
 481         device->profile.dasd_io_nr_req[counter]++;
 482 }
 483
 484 /*
 485  * Add profiling information for cqr after execution.
 486  */
 487 static inline void
 488 dasd_profile_end(struct dasd_device *device, struct dasd_ccw_req * cqr,
 489                  struct request *req)
 490 {
 491         long strtime, irqtime, endtime, tottime;        /* in microseconds */
 492         long tottimeps, sectors;
 493
 494         if (dasd_profile_level != DASD_PROFILE_ON)
 495                 return;
 496
 497         sectors = req->nr_sectors;
 498         if (!cqr->buildclk || !cqr->startclk ||
 499             !cqr->stopclk || !cqr->endclk ||
 500             !sectors)
 501                 return;
 502
 503         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 504         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 505         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 506         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 507         tottimeps = tottime / sectors;
 508
 509         if (!dasd_global_profile.dasd_io_reqs)
 510                 memset(&dasd_global_profile, 0,
 511                        sizeof (struct dasd_profile_info_t));
 512         dasd_global_profile.dasd_io_reqs++;
 513         dasd_global_profile.dasd_io_sects += sectors;
 514
 515         if (!device->profile.dasd_io_reqs)
 516                 memset(&device->profile, 0,
 517                        sizeof (struct dasd_profile_info_t));
 518         device->profile.dasd_io_reqs++;
 519         device->profile.dasd_io_sects += sectors;
 520
 521         dasd_profile_counter(sectors, dasd_io_secs, device);
 522         dasd_profile_counter(tottime, dasd_io_times, device);
 523         dasd_profile_counter(tottimeps, dasd_io_timps, device);
 524         dasd_profile_counter(strtime, dasd_io_time1, device);
 525         dasd_profile_counter(irqtime, dasd_io_time2, device);
 526         dasd_profile_counter(irqtime / sectors, dasd_io_time2ps, device);
 527         dasd_profile_counter(endtime, dasd_io_time3, device);
 528 }
 529 #else
 530 #define dasd_profile_start(device, cqr, req) do {} while (0)
 531 #define dasd_profile_end(device, cqr, req) do {} while (0)
 532 #endif                          /* CONFIG_DASD_PROFILE */
 533
 534 /*
 535  * Allocate memory for a channel program with 'cplength' channel
 536  * command words and 'datasize' additional space. There are two
 537  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
 538  * memory and 2) dasd_smalloc_request uses the static ccw memory
 539  * that gets allocated for each device.
 540  */
 541 struct dasd_ccw_req *
 542 dasd_kmalloc_request(char *magic, int cplength, int datasize,
 543                    struct dasd_device * device)
 544 {
 545         struct dasd_ccw_req *cqr;
 546
 547         /* Sanity checks */
 548         BUG_ON( magic == NULL || datasize > PAGE_SIZE ||
 549              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
 550
 551         cqr = kzalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
 552         if (cqr == NULL)
 553                 return ERR_PTR(-ENOMEM);
 554         cqr->cpaddr = NULL;
 555         if (cplength > 0) {
 556                 cqr->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
 557                                       GFP_ATOMIC | GFP_DMA);
 558                 if (cqr->cpaddr == NULL) {
 559                         kfree(cqr);
 560                         return ERR_PTR(-ENOMEM);
 561                 }
 562         }
 563         cqr->data = NULL;
 564         if (datasize > 0) {
 565                 cqr->data = kzalloc(datasize, GFP_ATOMIC | GFP_DMA);
 566                 if (cqr->data == NULL) {
 567                         kfree(cqr->cpaddr);
 568                         kfree(cqr);
 569                         return ERR_PTR(-ENOMEM);
 570                 }
 571         }
 572         strncpy((char *) &cqr->magic, magic, 4);
 573         ASCEBC((char *) &cqr->magic, 4);
 574         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
 575         dasd_get_device(device);
 576         return cqr;
 577 }
 578
 579 struct dasd_ccw_req *
 580 dasd_smalloc_request(char *magic, int cplength, int datasize,
 581                    struct dasd_device * device)
 582 {
 583         unsigned long flags;
 584         struct dasd_ccw_req *cqr;
 585         char *data;
 586         int size;
 587
 588         /* Sanity checks */
 589         BUG_ON( magic == NULL || datasize > PAGE_SIZE ||
 590              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
 591
 592         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
 593         if (cplength > 0)
 594                 size += cplength * sizeof(struct ccw1);
 595         if (datasize > 0)
 596                 size += datasize;
 597         spin_lock_irqsave(&device->mem_lock, flags);
 598         cqr = (struct dasd_ccw_req *)
 599                 dasd_alloc_chunk(&device->ccw_chunks, size);
 600         spin_unlock_irqrestore(&device->mem_lock, flags);
 601         if (cqr == NULL)
 602                 return ERR_PTR(-ENOMEM);
 603         memset(cqr, 0, sizeof(struct dasd_ccw_req));
 604         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
 605         cqr->cpaddr = NULL;
 606         if (cplength > 0) {
 607                 cqr->cpaddr = (struct ccw1 *) data;
 608                 data += cplength*sizeof(struct ccw1);
 609                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
 610         }
 611         cqr->data = NULL;
 612         if (datasize > 0) {
 613                 cqr->data = data;
 614                 memset(cqr->data, 0, datasize);
 615         }
 616         strncpy((char *) &cqr->magic, magic, 4);
 617         ASCEBC((char *) &cqr->magic, 4);
 618         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
 619         dasd_get_device(device);
 620         return cqr;
 621 }
 622
 623 /*
 624  * Free memory of a channel program. This function needs to free all the
 625  * idal lists that might have been created by dasd_set_cda and the
 626  * struct dasd_ccw_req itself.
 627  */
 628 void
 629 dasd_kfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
 630 {
 631 #ifdef CONFIG_64BIT
 632         struct ccw1 *ccw;
 633
 634         /* Clear any idals used for the request. */
 635         ccw = cqr->cpaddr;
 636         do {
 637                 clear_normalized_cda(ccw);
 638         } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
 639 #endif
 640         kfree(cqr->cpaddr);
 641         kfree(cqr->data);
 642         kfree(cqr);
 643         dasd_put_device(device);
 644 }
 645
 646 void
 647 dasd_sfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
 648 {
 649         unsigned long flags;
 650
 651         spin_lock_irqsave(&device->mem_lock, flags);
 652         dasd_free_chunk(&device->ccw_chunks, cqr);
 653         spin_unlock_irqrestore(&device->mem_lock, flags);
 654         dasd_put_device(device);
 655 }
 656
 657 /*
 658  * Check discipline magic in cqr.
 659  */
 660 static inline int
 661 dasd_check_cqr(struct dasd_ccw_req *cqr)
 662 {
 663         struct dasd_device *device;
 664
 665         if (cqr == NULL)
 666                 return -EINVAL;
 667         device = cqr->device;
 668         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
 669                 DEV_MESSAGE(KERN_WARNING, device,
 670                             " dasd_ccw_req 0x%08x magic doesn't match"
 671                             " discipline 0x%08x",
 672                             cqr->magic,
 673                             *(unsigned int *) device->discipline->name);
 674                 return -EINVAL;
 675         }
 676         return 0;
 677 }
 678
 679 /*
 680  * Terminate the current i/o and set the request to clear_pending.
 681  * Timer keeps device runnig.
 682  * ccw_device_clear can fail if the i/o subsystem
 683  * is in a bad mood.
 684  */
 685 int
 686 dasd_term_IO(struct dasd_ccw_req * cqr)
 687 {
 688         struct dasd_device *device;
 689         int retries, rc;
 690
 691         /* Check the cqr */
 692         rc = dasd_check_cqr(cqr);
 693         if (rc)
 694                 return rc;
 695         retries = 0;
 696         device = (struct dasd_device *) cqr->device;
 697         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
 698                 rc = ccw_device_clear(device->cdev, (long) cqr);
 699                 switch (rc) {
 700                 case 0: /* termination successful */
 701                         cqr->retries--;
 702                         cqr->status = DASD_CQR_CLEAR;
 703                         cqr->stopclk = get_clock();
 704                         DBF_DEV_EVENT(DBF_DEBUG, device,
 705                                       "terminate cqr %p successful",
 706                                       cqr);
 707                         break;
 708                 case -ENODEV:
 709                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 710                                       "device gone, retry");
 711                         break;
 712                 case -EIO:
 713                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 714                                       "I/O error, retry");
 715                         break;
 716                 case -EINVAL:
 717                 case -EBUSY:
 718                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 719                                       "device busy, retry later");
 720                         break;
 721                 default:
 722                         DEV_MESSAGE(KERN_ERR, device,
 723                                     "line %d unknown RC=%d, please "
 724                                     "report to linux390@de.ibm.com",
 725                                     __LINE__, rc);
 726                         BUG();
 727                         break;
 728                 }
 729                 retries++;
 730         }
 731         dasd_schedule_bh(device);
 732         return rc;
 733 }
 734
 735 /*
 736  * Start the i/o. This start_IO can fail if the channel is really busy.
 737  * In that case set up a timer to start the request later.
 738  */
 739 int
 740 dasd_start_IO(struct dasd_ccw_req * cqr)
 741 {
 742         struct dasd_device *device;
 743         int rc;
 744
 745         /* Check the cqr */
 746         rc = dasd_check_cqr(cqr);
 747         if (rc)
 748                 return rc;
 749         device = (struct dasd_device *) cqr->device;
 750         if (cqr->retries < 0) {
 751                 DEV_MESSAGE(KERN_DEBUG, device,
 752                             "start_IO: request %p (%02x/%i) - no retry left.",
 753                             cqr, cqr->status, cqr->retries);
 754                 cqr->status = DASD_CQR_FAILED;
 755                 return -EIO;
 756         }
 757         cqr->startclk = get_clock();
 758         cqr->starttime = jiffies;
 759         cqr->retries--;
 760         rc = ccw_device_start(device->cdev, cqr->cpaddr, (long) cqr,
 761                               cqr->lpm, 0);
 762         switch (rc) {
 763         case 0:
 764                 cqr->status = DASD_CQR_IN_IO;
 765                 DBF_DEV_EVENT(DBF_DEBUG, device,
 766                               "start_IO: request %p started successful",
 767                               cqr);
 768                 break;
 769         case -EBUSY:
 770                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 771                               "start_IO: device busy, retry later");
 772                 break;
 773         case -ETIMEDOUT:
 774                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 775                               "start_IO: request timeout, retry later");
 776                 break;
 777         case -EACCES:
 778                 /* -EACCES indicates that the request used only a
 779                  * subset of the available pathes and all these
 780                  * pathes are gone.
 781                  * Do a retry with all available pathes.
 782                  */
 783                 cqr->lpm = LPM_ANYPATH;
 784                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 785                               "start_IO: selected pathes gone,"
 786                               " retry on all pathes");
 787                 break;
 788         case -ENODEV:
 789         case -EIO:
 790                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 791                               "start_IO: device gone, retry");
 792                 break;
 793         default:
 794                 DEV_MESSAGE(KERN_ERR, device,
 795                             "line %d unknown RC=%d, please report"
 796                             " to linux390@de.ibm.com", __LINE__, rc);
 797                 BUG();
 798                 break;
 799         }
 800         return rc;
 801 }
 802
 803 /*
 804  * Timeout function for dasd devices. This is used for different purposes
 805  *  1) missing interrupt handler for normal operation
 806  *  2) delayed start of request where start_IO failed with -EBUSY
 807  *  3) timeout for missing state change interrupts
 808  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
 809  * DASD_CQR_QUEUED for 2) and 3).
 810  */
 811 static void
 812 dasd_timeout_device(unsigned long ptr)
 813 {
 814         unsigned long flags;
 815         struct dasd_device *device;
 816
 817         device = (struct dasd_device *) ptr;
 818         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
 819         /* re-activate request queue */
 820         device->stopped &= ~DASD_STOPPED_PENDING;
 821         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
 822         dasd_schedule_bh(device);
 823 }
 824
 825 /*
 826  * Setup timeout for a device in jiffies.
 827  */
 828 void
 829 dasd_set_timer(struct dasd_device *device, int expires)
 830 {
 831         if (expires == 0) {
 832                 if (timer_pending(&device->timer))
 833                         del_timer(&device->timer);
 834                 return;
 835         }
 836         if (timer_pending(&device->timer)) {
 837                 if (mod_timer(&device->timer, jiffies + expires))
 838                         return;
 839         }
 840         device->timer.function = dasd_timeout_device;
 841         device->timer.data = (unsigned long) device;
 842         device->timer.expires = jiffies + expires;
 843         add_timer(&device->timer);
 844 }
 845
 846 /*
 847  * Clear timeout for a device.
 848  */
 849 void
 850 dasd_clear_timer(struct dasd_device *device)
 851 {
 852         if (timer_pending(&device->timer))
 853                 del_timer(&device->timer);
 854 }
 855
 856 static void
 857 dasd_handle_killed_request(struct ccw_device *cdev, unsigned long intparm)
 858 {
 859         struct dasd_ccw_req *cqr;
 860         struct dasd_device *device;
 861
 862         cqr = (struct dasd_ccw_req *) intparm;
 863         if (cqr->status != DASD_CQR_IN_IO) {
 864                 MESSAGE(KERN_DEBUG,
 865                         "invalid status in handle_killed_request: "
 866                         "bus_id %s, status %02x",
 867                         cdev->dev.bus_id, cqr->status);
 868                 return;
 869         }
 870
 871         device = (struct dasd_device *) cqr->device;
 872         if (device == NULL ||
 873             device != dasd_device_from_cdev(cdev) ||
 874             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
 875                 MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
 876                         cdev->dev.bus_id);
 877                 return;
 878         }
 879
 880         /* Schedule request to be retried. */
 881         cqr->status = DASD_CQR_QUEUED;
 882
 883         dasd_clear_timer(device);
 884         dasd_schedule_bh(device);
 885         dasd_put_device(device);
 886 }
 887
 888 static void
 889 dasd_handle_state_change_pending(struct dasd_device *device)
 890 {
 891         struct dasd_ccw_req *cqr;
 892         struct list_head *l, *n;
 893
 894         /* First of all start sense subsystem status request. */
 895         dasd_eer_snss(device);
 896
 897         device->stopped &= ~DASD_STOPPED_PENDING;
 898
 899         /* restart all 'running' IO on queue */
 900         list_for_each_safe(l, n, &device->ccw_queue) {
 901                 cqr = list_entry(l, struct dasd_ccw_req, list);
 902                 if (cqr->status == DASD_CQR_IN_IO) {
 903                         cqr->status = DASD_CQR_QUEUED;
 904                 }
 905         }
 906         dasd_clear_timer(device);
 907         dasd_schedule_bh(device);
 908 }
 909
 910 /*
 911  * Interrupt handler for "normal" ssch-io based dasd devices.
 912  */
 913 void
 914 dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
 915                  struct irb *irb)
 916 {
 917         struct dasd_ccw_req *cqr, *next;
 918         struct dasd_device *device;
 919         unsigned long long now;
 920         int expires;
 921         dasd_era_t era;
 922         char mask;
 923
 924         if (IS_ERR(irb)) {
 925                 switch (PTR_ERR(irb)) {
 926                 case -EIO:
 927                         dasd_handle_killed_request(cdev, intparm);
 928                         break;
 929                 case -ETIMEDOUT:
 930                         printk(KERN_WARNING"%s(%s): request timed out\n",
 931                                __FUNCTION__, cdev->dev.bus_id);
 932                         //FIXME - dasd uses own timeout interface...
 933                         break;
 934                 default:
 935                         printk(KERN_WARNING"%s(%s): unknown error %ld\n",
 936                                __FUNCTION__, cdev->dev.bus_id, PTR_ERR(irb));
 937                 }
 938                 return;
 939         }
 940
 941         now = get_clock();
 942
 943         DBF_EVENT(DBF_ERR, "Interrupt: bus_id %s CS/DS %04x ip %08x",
 944                   cdev->dev.bus_id, ((irb->scsw.cstat<<8)|irb->scsw.dstat),
 945                   (unsigned int) intparm);
 946
 947         /* first of all check for state change pending interrupt */
 948         mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP;
 949         if ((irb->scsw.dstat & mask) == mask) {
 950                 device = dasd_device_from_cdev(cdev);
 951                 if (!IS_ERR(device)) {
 952                         dasd_handle_state_change_pending(device);
 953                         dasd_put_device(device);
 954                 }
 955                 return;
 956         }
 957
 958         cqr = (struct dasd_ccw_req *) intparm;
 959
 960         /* check for unsolicited interrupts */
 961         if (cqr == NULL) {
 962                 MESSAGE(KERN_DEBUG,
 963                         "unsolicited interrupt received: bus_id %s",
 964                         cdev->dev.bus_id);
 965                 return;
 966         }
 967
 968         device = (struct dasd_device *) cqr->device;
 969         if (device == NULL ||
 970             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
 971                 MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
 972                         cdev->dev.bus_id);
 973                 return;
 974         }
 975
 976         /* Check for clear pending */
 977         if (cqr->status == DASD_CQR_CLEAR &&
 978             irb->scsw.fctl & SCSW_FCTL_CLEAR_FUNC) {
 979                 cqr->status = DASD_CQR_QUEUED;
 980                 dasd_clear_timer(device);
 981                 dasd_schedule_bh(device);
 982                 return;
 983         }
 984
 985         /* check status - the request might have been killed by dyn detach */
 986         if (cqr->status != DASD_CQR_IN_IO) {
 987                 MESSAGE(KERN_DEBUG,
 988                         "invalid status: bus_id %s, status %02x",
 989                         cdev->dev.bus_id, cqr->status);
 990                 return;
 991         }
 992         DBF_DEV_EVENT(DBF_DEBUG, device, "Int: CS/DS 0x%04x for cqr %p",
 993                       ((irb->scsw.cstat << 8) | irb->scsw.dstat), cqr);
 994
 995         /* Find out the appropriate era_action. */
 996         if (irb->scsw.fctl & SCSW_FCTL_HALT_FUNC)
 997                 era = dasd_era_fatal;
 998         else if (irb->scsw.dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
 999                  irb->scsw.cstat == 0 &&
1000                  !irb->esw.esw0.erw.cons)
1001                 era = dasd_era_none;
1002         else if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags))
1003                 era = dasd_era_fatal; /* don't recover this request */
1004         else if (irb->esw.esw0.erw.cons)
1005                 era = device->discipline->examine_error(cqr, irb);
1006         else
1007                 era = dasd_era_recover;
1008
1009         DBF_DEV_EVENT(DBF_DEBUG, device, "era_code %d", era);
1010         expires = 0;
1011         if (era == dasd_era_none) {
1012                 cqr->status = DASD_CQR_DONE;
1013                 cqr->stopclk = now;
1014                 /* Start first request on queue if possible -> fast_io. */
1015                 if (cqr->list.next != &device->ccw_queue) {
1016                         next = list_entry(cqr->list.next,
1017                                           struct dasd_ccw_req, list);
1018                         if ((next->status == DASD_CQR_QUEUED) &&
1019                             (!device->stopped)) {
1020                                 if (device->discipline->start_IO(next) == 0)
1021                                         expires = next->expires;
1022                                 else
1023                                         DEV_MESSAGE(KERN_DEBUG, device, "%s",
1024                                                     "Interrupt fastpath "
1025                                                     "failed!");
1026                         }
1027                 }
1028         } else {                /* error */
1029                 memcpy(&cqr->irb, irb, sizeof (struct irb));
1030 #ifdef ERP_DEBUG
1031                 /* dump sense data */
1032                 dasd_log_sense(cqr, irb);
1033 #endif
1034                 switch (era) {
1035                 case dasd_era_fatal:
1036                         cqr->status = DASD_CQR_FAILED;
1037                         cqr->stopclk = now;
1038                         break;
1039                 case dasd_era_recover:
1040                         cqr->status = DASD_CQR_ERROR;
1041                         break;
1042                 default:
1043                         BUG();
1044                 }
1045         }
1046         if (expires != 0)
1047                 dasd_set_timer(device, expires);
1048         else
1049                 dasd_clear_timer(device);
1050         dasd_schedule_bh(device);
1051 }
1052
1053 /*
1054  * posts the buffer_cache about a finalized request
1055  */
1056 static inline void
1057 dasd_end_request(struct request *req, int uptodate)
1058 {
1059         if (end_that_request_first(req, uptodate, req->hard_nr_sectors))
1060                 BUG();
1061         add_disk_randomness(req->rq_disk);
1062         end_that_request_last(req, uptodate);
1063 }
1064
1065 /*
1066  * Process finished error recovery ccw.
1067  */
1068 static inline void
1069 __dasd_process_erp(struct dasd_device *device, struct dasd_ccw_req *cqr)
1070 {
1071         dasd_erp_fn_t erp_fn;
1072
1073         if (cqr->status == DASD_CQR_DONE)
1074                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
1075         else
1076                 DEV_MESSAGE(KERN_ERR, device, "%s", "ERP unsuccessful");
1077         erp_fn = device->discipline->erp_postaction(cqr);
1078         erp_fn(cqr);
1079 }
1080
1081 /*
1082  * Process ccw request queue.
1083  */
1084 static inline void
1085 __dasd_process_ccw_queue(struct dasd_device * device,
1086                          struct list_head *final_queue)
1087 {
1088         struct list_head *l, *n;
1089         struct dasd_ccw_req *cqr;
1090         dasd_erp_fn_t erp_fn;
1091
1092 restart:
1093         /* Process request with final status. */
1094         list_for_each_safe(l, n, &device->ccw_queue) {
1095                 cqr = list_entry(l, struct dasd_ccw_req, list);
1096                 /* Stop list processing at the first non-final request. */
1097                 if (cqr->status != DASD_CQR_DONE &&
1098                     cqr->status != DASD_CQR_FAILED &&
1099                     cqr->status != DASD_CQR_ERROR)
1100                         break;
1101                 /*  Process requests with DASD_CQR_ERROR */
1102                 if (cqr->status == DASD_CQR_ERROR) {
1103                         if (cqr->irb.scsw.fctl & SCSW_FCTL_HALT_FUNC) {
1104                                 cqr->status = DASD_CQR_FAILED;
1105                                 cqr->stopclk = get_clock();
1106                         } else {
1107                                 if (cqr->irb.esw.esw0.erw.cons) {
1108                                         erp_fn = device->discipline->
1109                                                 erp_action(cqr);
1110                                         erp_fn(cqr);
1111                                 } else
1112                                         dasd_default_erp_action(cqr);
1113                         }
1114                         goto restart;
1115                 }
1116
1117                 /* First of all call extended error reporting. */
1118                 if (dasd_eer_enabled(device) &&
1119                     cqr->status == DASD_CQR_FAILED) {
1120                         dasd_eer_write(device, cqr, DASD_EER_FATALERROR);
1121
1122                         /* restart request  */
1123                         cqr->status = DASD_CQR_QUEUED;
1124                         cqr->retries = 255;
1125                         device->stopped |= DASD_STOPPED_QUIESCE;
1126                         goto restart;
1127                 }
1128
1129                 /* Process finished ERP request. */
1130                 if (cqr->refers) {
1131                         __dasd_process_erp(device, cqr);
1132                         goto restart;
1133                 }
1134
1135                 /* Rechain finished requests to final queue */
1136                 cqr->endclk = get_clock();
1137                 list_move_tail(&cqr->list, final_queue);
1138         }
1139 }
1140
1141 static void
1142 dasd_end_request_cb(struct dasd_ccw_req * cqr, void *data)
1143 {
1144         struct request *req;
1145         struct dasd_device *device;
1146         int status;
1147
1148         req = (struct request *) data;
1149         device = cqr->device;
1150         dasd_profile_end(device, cqr, req);
1151         status = cqr->device->discipline->free_cp(cqr,req);
1152         spin_lock_irq(&device->request_queue_lock);
1153         dasd_end_request(req, status);
1154         spin_unlock_irq(&device->request_queue_lock);
1155 }
1156
1157
1158 /*
1159  * Fetch requests from the block device queue.
1160  */
1161 static inline void
1162 __dasd_process_blk_queue(struct dasd_device * device)
1163 {
1164         request_queue_t *queue;
1165         struct request *req;
1166         struct dasd_ccw_req *cqr;
1167         int nr_queued;
1168
1169         queue = device->request_queue;
1170         /* No queue ? Then there is nothing to do. */
1171         if (queue == NULL)
1172                 return;
1173
1174         /*
1175          * We requeue request from the block device queue to the ccw
1176          * queue only in two states. In state DASD_STATE_READY the
1177          * partition detection is done and we need to requeue requests
1178          * for that. State DASD_STATE_ONLINE is normal block device
1179          * operation.
1180          */
1181         if (device->state != DASD_STATE_READY &&
1182             device->state != DASD_STATE_ONLINE)
1183                 return;
1184         nr_queued = 0;
1185         /* Now we try to fetch requests from the request queue */
1186         list_for_each_entry(cqr, &device->ccw_queue, list)
1187                 if (cqr->status == DASD_CQR_QUEUED)
1188                         nr_queued++;
1189         while (!blk_queue_plugged(queue) &&
1190                elv_next_request(queue) &&
1191                 nr_queued < DASD_CHANQ_MAX_SIZE) {
1192                 req = elv_next_request(queue);
1193
1194                 if (device->features & DASD_FEATURE_READONLY &&
1195                     rq_data_dir(req) == WRITE) {
1196                         DBF_DEV_EVENT(DBF_ERR, device,
1197                                       "Rejecting write request %p",
1198                                       req);
1199                         blkdev_dequeue_request(req);
1200                         dasd_end_request(req, 0);
1201                         continue;
1202                 }
1203                 if (device->stopped & DASD_STOPPED_DC_EIO) {
1204                         blkdev_dequeue_request(req);
1205                         dasd_end_request(req, 0);
1206                         continue;
1207                 }
1208                 cqr = device->discipline->build_cp(device, req);
1209                 if (IS_ERR(cqr)) {
1210                         if (PTR_ERR(cqr) == -ENOMEM)
1211                                 break;  /* terminate request queue loop */
1212                         DBF_DEV_EVENT(DBF_ERR, device,
1213                                       "CCW creation failed (rc=%ld) "
1214                                       "on request %p",
1215                                       PTR_ERR(cqr), req);
1216                         blkdev_dequeue_request(req);
1217                         dasd_end_request(req, 0);
1218                         continue;
1219                 }
1220                 cqr->callback = dasd_end_request_cb;
1221                 cqr->callback_data = (void *) req;
1222                 cqr->status = DASD_CQR_QUEUED;
1223                 blkdev_dequeue_request(req);
1224                 list_add_tail(&cqr->list, &device->ccw_queue);
1225                 dasd_profile_start(device, cqr, req);
1226                 nr_queued++;
1227         }
1228 }
1229
1230 /*
1231  * Take a look at the first request on the ccw queue and check
1232  * if it reached its expire time. If so, terminate the IO.
1233  */
1234 static inline void
1235 __dasd_check_expire(struct dasd_device * device)
1236 {
1237         struct dasd_ccw_req *cqr;
1238
1239         if (list_empty(&device->ccw_queue))
1240                 return;
1241         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1242         if (cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) {
1243                 if (time_after_eq(jiffies, cqr->expires + cqr->starttime)) {
1244                         if (device->discipline->term_IO(cqr) != 0)
1245                                 /* Hmpf, try again in 1/10 sec */
1246                                 dasd_set_timer(device, 10);
1247                 }
1248         }
1249 }
1250
1251 /*
1252  * Take a look at the first request on the ccw queue and check
1253  * if it needs to be started.
1254  */
1255 static inline void
1256 __dasd_start_head(struct dasd_device * device)
1257 {
1258         struct dasd_ccw_req *cqr;
1259         int rc;
1260
1261         if (list_empty(&device->ccw_queue))
1262                 return;
1263         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1264         if (cqr->status != DASD_CQR_QUEUED)
1265                 return;
1266         /* Non-temporary stop condition will trigger fail fast */
1267         if (device->stopped & ~DASD_STOPPED_PENDING &&
1268             test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
1269             (!dasd_eer_enabled(device))) {
1270                 cqr->status = DASD_CQR_FAILED;
1271                 dasd_schedule_bh(device);
1272                 return;
1273         }
1274         /* Don't try to start requests if device is stopped */
1275         if (device->stopped)
1276                 return;
1277
1278         rc = device->discipline->start_IO(cqr);
1279         if (rc == 0)
1280                 dasd_set_timer(device, cqr->expires);
1281         else if (rc == -EACCES) {
1282                 dasd_schedule_bh(device);
1283         } else
1284                 /* Hmpf, try again in 1/2 sec */
1285                 dasd_set_timer(device, 50);
1286 }
1287
1288 /*
1289  * Remove requests from the ccw queue.
1290  */
1291 static void
1292 dasd_flush_ccw_queue(struct dasd_device * device, int all)
1293 {
1294         struct list_head flush_queue;
1295         struct list_head *l, *n;
1296         struct dasd_ccw_req *cqr;
1297
1298         INIT_LIST_HEAD(&flush_queue);
1299         spin_lock_irq(get_ccwdev_lock(device->cdev));
1300         list_for_each_safe(l, n, &device->ccw_queue) {
1301                 cqr = list_entry(l, struct dasd_ccw_req, list);
1302                 /* Flush all request or only block device requests? */
1303                 if (all == 0 && cqr->callback == dasd_end_request_cb)
1304                         continue;
1305                 if (cqr->status == DASD_CQR_IN_IO)
1306                         device->discipline->term_IO(cqr);
1307                 if (cqr->status != DASD_CQR_DONE ||
1308                     cqr->status != DASD_CQR_FAILED) {
1309                         cqr->status = DASD_CQR_FAILED;
1310                         cqr->stopclk = get_clock();
1311                 }
1312                 /* Process finished ERP request. */
1313                 if (cqr->refers) {
1314                         __dasd_process_erp(device, cqr);
1315                         continue;
1316                 }
1317                 /* Rechain request on device request queue */
1318                 cqr->endclk = get_clock();
1319                 list_move_tail(&cqr->list, &flush_queue);
1320         }
1321         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1322         /* Now call the callback function of flushed requests */
1323         list_for_each_safe(l, n, &flush_queue) {
1324                 cqr = list_entry(l, struct dasd_ccw_req, list);
1325                 if (cqr->callback != NULL)
1326                         (cqr->callback)(cqr, cqr->callback_data);
1327         }
1328 }
1329
1330 /*
1331  * Acquire the device lock and process queues for the device.
1332  */
1333 static void
1334 dasd_tasklet(struct dasd_device * device)
1335 {
1336         struct list_head final_queue;
1337         struct list_head *l, *n;
1338         struct dasd_ccw_req *cqr;
1339
1340         atomic_set (&device->tasklet_scheduled, 0);
1341         INIT_LIST_HEAD(&final_queue);
1342         spin_lock_irq(get_ccwdev_lock(device->cdev));
1343         /* Check expire time of first request on the ccw queue. */
1344         __dasd_check_expire(device);
1345         /* Finish off requests on ccw queue */
1346         __dasd_process_ccw_queue(device, &final_queue);
1347         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1348         /* Now call the callback function of requests with final status */
1349         list_for_each_safe(l, n, &final_queue) {
1350                 cqr = list_entry(l, struct dasd_ccw_req, list);
1351                 list_del_init(&cqr->list);
1352                 if (cqr->callback != NULL)
1353                         (cqr->callback)(cqr, cqr->callback_data);
1354         }
1355         spin_lock_irq(&device->request_queue_lock);
1356         spin_lock(get_ccwdev_lock(device->cdev));
1357         /* Get new request from the block device request queue */
1358         __dasd_process_blk_queue(device);
1359         /* Now check if the head of the ccw queue needs to be started. */
1360         __dasd_start_head(device);
1361         spin_unlock(get_ccwdev_lock(device->cdev));
1362         spin_unlock_irq(&device->request_queue_lock);
1363         dasd_put_device(device);
1364 }
1365
1366 /*
1367  * Schedules a call to dasd_tasklet over the device tasklet.
1368  */
1369 void
1370 dasd_schedule_bh(struct dasd_device * device)
1371 {
1372         /* Protect against rescheduling. */
1373         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
1374                 return;
1375         dasd_get_device(device);
1376         tasklet_hi_schedule(&device->tasklet);
1377 }
1378
1379 /*
1380  * Queue a request to the head of the ccw_queue. Start the I/O if
1381  * possible.
1382  */
1383 void
1384 dasd_add_request_head(struct dasd_ccw_req *req)
1385 {
1386         struct dasd_device *device;
1387         unsigned long flags;
1388
1389         device = req->device;
1390         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1391         req->status = DASD_CQR_QUEUED;
1392         req->device = device;
1393         list_add(&req->list, &device->ccw_queue);
1394         /* let the bh start the request to keep them in order */
1395         dasd_schedule_bh(device);
1396         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1397 }
1398
1399 /*
1400  * Queue a request to the tail of the ccw_queue. Start the I/O if
1401  * possible.
1402  */
1403 void
1404 dasd_add_request_tail(struct dasd_ccw_req *req)
1405 {
1406         struct dasd_device *device;
1407         unsigned long flags;
1408
1409         device = req->device;
1410         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1411         req->status = DASD_CQR_QUEUED;
1412         req->device = device;
1413         list_add_tail(&req->list, &device->ccw_queue);
1414         /* let the bh start the request to keep them in order */
1415         dasd_schedule_bh(device);
1416         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1417 }
1418
1419 /*
1420  * Wakeup callback.
1421  */
1422 static void
1423 dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
1424 {
1425         wake_up((wait_queue_head_t *) data);
1426 }
1427
1428 static inline int
1429 _wait_for_wakeup(struct dasd_ccw_req *cqr)
1430 {
1431         struct dasd_device *device;
1432         int rc;
1433
1434         device = cqr->device;
1435         spin_lock_irq(get_ccwdev_lock(device->cdev));
1436         rc = ((cqr->status == DASD_CQR_DONE ||
1437                cqr->status == DASD_CQR_FAILED) &&
1438               list_empty(&cqr->list));
1439         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1440         return rc;
1441 }
1442
1443 /*
1444  * Attempts to start a special ccw queue and waits for its completion.
1445  */
1446 int
1447 dasd_sleep_on(struct dasd_ccw_req * cqr)
1448 {
1449         wait_queue_head_t wait_q;
1450         struct dasd_device *device;
1451         int rc;
1452
1453         device = cqr->device;
1454         spin_lock_irq(get_ccwdev_lock(device->cdev));
1455
1456         init_waitqueue_head (&wait_q);
1457         cqr->callback = dasd_wakeup_cb;
1458         cqr->callback_data = (void *) &wait_q;
1459         cqr->status = DASD_CQR_QUEUED;
1460         list_add_tail(&cqr->list, &device->ccw_queue);
1461
1462         /* let the bh start the request to keep them in order */
1463         dasd_schedule_bh(device);
1464
1465         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1466
1467         wait_event(wait_q, _wait_for_wakeup(cqr));
1468
1469         /* Request status is either done or failed. */
1470         rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1471         return rc;
1472 }
1473
1474 /*
1475  * Attempts to start a special ccw queue and wait interruptible
1476  * for its completion.
1477  */
1478 int
1479 dasd_sleep_on_interruptible(struct dasd_ccw_req * cqr)
1480 {
1481         wait_queue_head_t wait_q;
1482         struct dasd_device *device;
1483         int rc, finished;
1484
1485         device = cqr->device;
1486         spin_lock_irq(get_ccwdev_lock(device->cdev));
1487
1488         init_waitqueue_head (&wait_q);
1489         cqr->callback = dasd_wakeup_cb;
1490         cqr->callback_data = (void *) &wait_q;
1491         cqr->status = DASD_CQR_QUEUED;
1492         list_add_tail(&cqr->list, &device->ccw_queue);
1493
1494         /* let the bh start the request to keep them in order */
1495         dasd_schedule_bh(device);
1496         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1497
1498         finished = 0;
1499         while (!finished) {
1500                 rc = wait_event_interruptible(wait_q, _wait_for_wakeup(cqr));
1501                 if (rc != -ERESTARTSYS) {
1502                         /* Request is final (done or failed) */
1503                         rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO;
1504                         break;
1505                 }
1506                 spin_lock_irq(get_ccwdev_lock(device->cdev));
1507                 switch (cqr->status) {
1508                 case DASD_CQR_IN_IO:
1509                         /* terminate runnig cqr */
1510                         if (device->discipline->term_IO) {
1511                                 cqr->retries = -1;
1512                                 device->discipline->term_IO(cqr);
1513                                 /*nished =
1514                                  * wait (non-interruptible) for final status
1515                                  * because signal ist still pending
1516                                  */
1517                                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1518                                 wait_event(wait_q, _wait_for_wakeup(cqr));
1519                                 spin_lock_irq(get_ccwdev_lock(device->cdev));
1520                                 rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO;
1521                                 finished = 1;
1522                         }
1523                         break;
1524                 case DASD_CQR_QUEUED:
1525                         /* request  */
1526                         list_del_init(&cqr->list);
1527                         rc = -EIO;
1528                         finished = 1;
1529                         break;
1530                 default:
1531                         /* cqr with 'non-interruptable' status - just wait */
1532                         break;
1533                 }
1534                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1535         }
1536         return rc;
1537 }
1538
1539 /*
1540  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
1541  * for eckd devices) the currently running request has to be terminated
1542  * and be put back to status queued, before the special request is added
1543  * to the head of the queue. Then the special request is waited on normally.
1544  */
1545 static inline int
1546 _dasd_term_running_cqr(struct dasd_device *device)
1547 {
1548         struct dasd_ccw_req *cqr;
1549         int rc;
1550
1551         if (list_empty(&device->ccw_queue))
1552                 return 0;
1553         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1554         rc = device->discipline->term_IO(cqr);
1555         if (rc == 0) {
1556                 /* termination successful */
1557                 cqr->status = DASD_CQR_QUEUED;
1558                 cqr->startclk = cqr->stopclk = 0;
1559                 cqr->starttime = 0;
1560         }
1561         return rc;
1562 }
1563
1564 int
1565 dasd_sleep_on_immediatly(struct dasd_ccw_req * cqr)
1566 {
1567         wait_queue_head_t wait_q;
1568         struct dasd_device *device;
1569         int rc;
1570
1571         device = cqr->device;
1572         spin_lock_irq(get_ccwdev_lock(device->cdev));
1573         rc = _dasd_term_running_cqr(device);
1574         if (rc) {
1575                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1576                 return rc;
1577         }
1578
1579         init_waitqueue_head (&wait_q);
1580         cqr->callback = dasd_wakeup_cb;
1581         cqr->callback_data = (void *) &wait_q;
1582         cqr->status = DASD_CQR_QUEUED;
1583         list_add(&cqr->list, &device->ccw_queue);
1584
1585         /* let the bh start the request to keep them in order */
1586         dasd_schedule_bh(device);
1587
1588         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1589
1590         wait_event(wait_q, _wait_for_wakeup(cqr));
1591
1592         /* Request status is either done or failed. */
1593         rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1594         return rc;
1595 }
1596
1597 /*
1598  * Cancels a request that was started with dasd_sleep_on_req.
1599  * This is useful to timeout requests. The request will be
1600  * terminated if it is currently in i/o.
1601  * Returns 1 if the request has been terminated.
1602  */
1603 int
1604 dasd_cancel_req(struct dasd_ccw_req *cqr)
1605 {
1606         struct dasd_device *device = cqr->device;
1607         unsigned long flags;
1608         int rc;
1609
1610         rc = 0;
1611         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1612         switch (cqr->status) {
1613         case DASD_CQR_QUEUED:
1614                 /* request was not started - just set to failed */
1615                 cqr->status = DASD_CQR_FAILED;
1616                 break;
1617         case DASD_CQR_IN_IO:
1618                 /* request in IO - terminate IO and release again */
1619                 if (device->discipline->term_IO(cqr) != 0)
1620                         /* what to do if unable to terminate ??????
1621                            e.g. not _IN_IO */
1622                         cqr->status = DASD_CQR_FAILED;
1623                 cqr->stopclk = get_clock();
1624                 rc = 1;
1625                 break;
1626         case DASD_CQR_DONE:
1627         case DASD_CQR_FAILED:
1628                 /* already finished - do nothing */
1629                 break;
1630         default:
1631                 DEV_MESSAGE(KERN_ALERT, device,
1632                             "invalid status %02x in request",
1633                             cqr->status);
1634                 BUG();
1635
1636         }
1637         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1638         dasd_schedule_bh(device);
1639         return rc;
1640 }
1641
1642 /*
1643  * SECTION: Block device operations (request queue, partitions, open, release).
1644  */
1645
1646 /*
1647  * Dasd request queue function. Called from ll_rw_blk.c
1648  */
1649 static void
1650 do_dasd_request(request_queue_t * queue)
1651 {
1652         struct dasd_device *device;
1653
1654         device = (struct dasd_device *) queue->queuedata;
1655         spin_lock(get_ccwdev_lock(device->cdev));
1656         /* Get new request from the block device request queue */
1657         __dasd_process_blk_queue(device);
1658         /* Now check if the head of the ccw queue needs to be started. */
1659         __dasd_start_head(device);
1660         spin_unlock(get_ccwdev_lock(device->cdev));
1661 }
1662
1663 /*
1664  * Allocate and initialize request queue and default I/O scheduler.
1665  */
1666 static int
1667 dasd_alloc_queue(struct dasd_device * device)
1668 {
1669         int rc;
1670
1671         device->request_queue = blk_init_queue(do_dasd_request,
1672                                                &device->request_queue_lock);
1673         if (device->request_queue == NULL)
1674                 return -ENOMEM;
1675
1676         device->request_queue->queuedata = device;
1677
1678         elevator_exit(device->request_queue->elevator);
1679         rc = elevator_init(device->request_queue, "deadline");
1680         if (rc) {
1681                 blk_cleanup_queue(device->request_queue);
1682                 return rc;
1683         }
1684         return 0;
1685 }
1686
1687 /*
1688  * Allocate and initialize request queue.
1689  */
1690 static void
1691 dasd_setup_queue(struct dasd_device * device)
1692 {
1693         int max;
1694
1695         blk_queue_hardsect_size(device->request_queue, device->bp_block);
1696         max = device->discipline->max_blocks << device->s2b_shift;
1697         blk_queue_max_sectors(device->request_queue, max);
1698         blk_queue_max_phys_segments(device->request_queue, -1L);
1699         blk_queue_max_hw_segments(device->request_queue, -1L);
1700         blk_queue_max_segment_size(device->request_queue, -1L);
1701         blk_queue_segment_boundary(device->request_queue, -1L);
1702         blk_queue_ordered(device->request_queue, QUEUE_ORDERED_TAG, NULL);
1703 }
1704
1705 /*
1706  * Deactivate and free request queue.
1707  */
1708 static void
1709 dasd_free_queue(struct dasd_device * device)
1710 {
1711         if (device->request_queue) {
1712                 blk_cleanup_queue(device->request_queue);
1713                 device->request_queue = NULL;
1714         }
1715 }
1716
1717 /*
1718  * Flush request on the request queue.
1719  */
1720 static void
1721 dasd_flush_request_queue(struct dasd_device * device)
1722 {
1723         struct request *req;
1724
1725         if (!device->request_queue)
1726                 return;
1727
1728         spin_lock_irq(&device->request_queue_lock);
1729         while (!list_empty(&device->request_queue->queue_head)) {
1730                 req = elv_next_request(device->request_queue);
1731                 if (req == NULL)
1732                         break;
1733                 blkdev_dequeue_request(req);
1734                 dasd_end_request(req, 0);
1735         }
1736         spin_unlock_irq(&device->request_queue_lock);
1737 }
1738
1739 static int
1740 dasd_open(struct inode *inp, struct file *filp)
1741 {
1742         struct gendisk *disk = inp->i_bdev->bd_disk;
1743         struct dasd_device *device = disk->private_data;
1744         int rc;
1745
1746         atomic_inc(&device->open_count);
1747         if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1748                 rc = -ENODEV;
1749                 goto unlock;
1750         }
1751
1752         if (!try_module_get(device->discipline->owner)) {
1753                 rc = -EINVAL;
1754                 goto unlock;
1755         }
1756
1757         if (dasd_probeonly) {
1758                 DEV_MESSAGE(KERN_INFO, device, "%s",
1759                             "No access to device due to probeonly mode");
1760                 rc = -EPERM;
1761                 goto out;
1762         }
1763
1764         if (device->state <= DASD_STATE_BASIC) {
1765                 DBF_DEV_EVENT(DBF_ERR, device, " %s",
1766                               " Cannot open unrecognized device");
1767                 rc = -ENODEV;
1768                 goto out;
1769         }
1770
1771         return 0;
1772
1773 out:
1774         module_put(device->discipline->owner);
1775 unlock:
1776         atomic_dec(&device->open_count);
1777         return rc;
1778 }
1779
1780 static int
1781 dasd_release(struct inode *inp, struct file *filp)
1782 {
1783         struct gendisk *disk = inp->i_bdev->bd_disk;
1784         struct dasd_device *device = disk->private_data;
1785
1786         atomic_dec(&device->open_count);
1787         module_put(device->discipline->owner);
1788         return 0;
1789 }
1790
1791 /*
1792  * Return disk geometry.
1793  */
1794 static int
1795 dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
1796 {
1797         struct dasd_device *device;
1798
1799         device = bdev->bd_disk->private_data;
1800         if (!device)
1801                 return -ENODEV;
1802
1803         if (!device->discipline ||
1804             !device->discipline->fill_geometry)
1805                 return -EINVAL;
1806
1807         device->discipline->fill_geometry(device, geo);
1808         geo->start = get_start_sect(bdev) >> device->s2b_shift;
1809         return 0;
1810 }
1811
1812 struct block_device_operations
1813 dasd_device_operations = {
1814         .owner          = THIS_MODULE,
1815         .open           = dasd_open,
1816         .release        = dasd_release,
1817         .ioctl          = dasd_ioctl,
1818         .compat_ioctl   = dasd_compat_ioctl,
1819         .getgeo         = dasd_getgeo,
1820 };
1821
1822
1823 static void
1824 dasd_exit(void)
1825 {
1826 #ifdef CONFIG_PROC_FS
1827         dasd_proc_exit();
1828 #endif
1829         dasd_eer_exit();
1830         if (dasd_page_cache != NULL) {
1831                 kmem_cache_destroy(dasd_page_cache);
1832                 dasd_page_cache = NULL;
1833         }
1834         dasd_gendisk_exit();
1835         dasd_devmap_exit();
1836         if (dasd_debug_area != NULL) {
1837                 debug_unregister(dasd_debug_area);
1838                 dasd_debug_area = NULL;
1839         }
1840 }
1841
1842 /*
1843  * SECTION: common functions for ccw_driver use
1844  */
1845
1846 /*
1847  * Initial attempt at a probe function. this can be simplified once
1848  * the other detection code is gone.
1849  */
1850 int
1851 dasd_generic_probe (struct ccw_device *cdev,
1852                     struct dasd_discipline *discipline)
1853 {
1854         int ret;
1855
1856         ret = ccw_device_set_options(cdev, CCWDEV_DO_PATHGROUP);
1857         if (ret) {
1858                 printk(KERN_WARNING
1859                        "dasd_generic_probe: could not set ccw-device options "
1860                        "for %s\n", cdev->dev.bus_id);
1861                 return ret;
1862         }
1863         ret = dasd_add_sysfs_files(cdev);
1864         if (ret) {
1865                 printk(KERN_WARNING
1866                        "dasd_generic_probe: could not add sysfs entries "
1867                        "for %s\n", cdev->dev.bus_id);
1868                 return ret;
1869         }
1870         cdev->handler = &dasd_int_handler;
1871
1872         /*
1873          * Automatically online either all dasd devices (dasd_autodetect)
1874          * or all devices specified with dasd= parameters during
1875          * initial probe.
1876          */
1877         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
1878             (dasd_autodetect && dasd_busid_known(cdev->dev.bus_id) != 0))
1879                 ret = ccw_device_set_online(cdev);
1880         if (ret)
1881                 printk(KERN_WARNING
1882                        "dasd_generic_probe: could not initially online "
1883                        "ccw-device %s\n", cdev->dev.bus_id);
1884         return ret;
1885 }
1886
1887 /*
1888  * This will one day be called from a global not_oper handler.
1889  * It is also used by driver_unregister during module unload.
1890  */
1891 void
1892 dasd_generic_remove (struct ccw_device *cdev)
1893 {
1894         struct dasd_device *device;
1895
1896         cdev->handler = NULL;
1897
1898         dasd_remove_sysfs_files(cdev);
1899         device = dasd_device_from_cdev(cdev);
1900         if (IS_ERR(device))
1901                 return;
1902         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1903                 /* Already doing offline processing */
1904                 dasd_put_device(device);
1905                 return;
1906         }
1907         /*
1908          * This device is removed unconditionally. Set offline
1909          * flag to prevent dasd_open from opening it while it is
1910          * no quite down yet.
1911          */
1912         dasd_set_target_state(device, DASD_STATE_NEW);
1913         /* dasd_delete_device destroys the device reference. */
1914         dasd_delete_device(device);
1915 }
1916
1917 /*
1918  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
1919  * the device is detected for the first time and is supposed to be used
1920  * or the user has started activation through sysfs.
1921  */
1922 int
1923 dasd_generic_set_online (struct ccw_device *cdev,
1924                          struct dasd_discipline *base_discipline)
1925
1926 {
1927         struct dasd_discipline *discipline;
1928         struct dasd_device *device;
1929         int rc;
1930
1931         /* first online clears initial online feature flag */
1932         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
1933         device = dasd_create_device(cdev);
1934         if (IS_ERR(device))
1935                 return PTR_ERR(device);
1936
1937         discipline = base_discipline;
1938         if (device->features & DASD_FEATURE_USEDIAG) {
1939                 if (!dasd_diag_discipline_pointer) {
1940                         printk (KERN_WARNING
1941                                 "dasd_generic couldn't online device %s "
1942                                 "- discipline DIAG not available\n",
1943                                 cdev->dev.bus_id);
1944                         dasd_delete_device(device);
1945                         return -ENODEV;
1946                 }
1947                 discipline = dasd_diag_discipline_pointer;
1948         }
1949         if (!try_module_get(base_discipline->owner)) {
1950                 dasd_delete_device(device);
1951                 return -EINVAL;
1952         }
1953         if (!try_module_get(discipline->owner)) {
1954                 module_put(base_discipline->owner);
1955                 dasd_delete_device(device);
1956                 return -EINVAL;
1957         }
1958         device->base_discipline = base_discipline;
1959         device->discipline = discipline;
1960
1961         rc = discipline->check_device(device);
1962         if (rc) {
1963                 printk (KERN_WARNING
1964                         "dasd_generic couldn't online device %s "
1965                         "with discipline %s rc=%i\n",
1966                         cdev->dev.bus_id, discipline->name, rc);
1967                 module_put(discipline->owner);
1968                 module_put(base_discipline->owner);
1969                 dasd_delete_device(device);
1970                 return rc;
1971         }
1972
1973         dasd_set_target_state(device, DASD_STATE_ONLINE);
1974         if (device->state <= DASD_STATE_KNOWN) {
1975                 printk (KERN_WARNING
1976                         "dasd_generic discipline not found for %s\n",
1977                         cdev->dev.bus_id);
1978                 rc = -ENODEV;
1979                 dasd_set_target_state(device, DASD_STATE_NEW);
1980                 dasd_delete_device(device);
1981         } else
1982                 pr_debug("dasd_generic device %s found\n",
1983                                 cdev->dev.bus_id);
1984
1985         /* FIXME: we have to wait for the root device but we don't want
1986          * to wait for each single device but for all at once. */
1987         wait_event(dasd_init_waitq, _wait_for_device(device));
1988
1989         dasd_put_device(device);
1990
1991         return rc;
1992 }
1993
1994 int
1995 dasd_generic_set_offline (struct ccw_device *cdev)
1996 {
1997         struct dasd_device *device;
1998         int max_count, open_count;
1999
2000         device = dasd_device_from_cdev(cdev);
2001         if (IS_ERR(device))
2002                 return PTR_ERR(device);
2003         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
2004                 /* Already doing offline processing */
2005                 dasd_put_device(device);
2006                 return 0;
2007         }
2008         /*
2009          * We must make sure that this device is currently not in use.
2010          * The open_count is increased for every opener, that includes
2011          * the blkdev_get in dasd_scan_partitions. We are only interested
2012          * in the other openers.
2013          */
2014         max_count = device->bdev ? 0 : -1;
2015         open_count = (int) atomic_read(&device->open_count);
2016         if (open_count > max_count) {
2017                 if (open_count > 0)
2018                         printk (KERN_WARNING "Can't offline dasd device with "
2019                                 "open count = %i.\n",
2020                                 open_count);
2021                 else
2022                         printk (KERN_WARNING "%s",
2023                                 "Can't offline dasd device due to internal "
2024                                 "use\n");
2025                 clear_bit(DASD_FLAG_OFFLINE, &device->flags);
2026                 dasd_put_device(device);
2027                 return -EBUSY;
2028         }
2029         dasd_set_target_state(device, DASD_STATE_NEW);
2030         /* dasd_delete_device destroys the device reference. */
2031         dasd_delete_device(device);
2032
2033         return 0;
2034 }
2035
2036 int
2037 dasd_generic_notify(struct ccw_device *cdev, int event)
2038 {
2039         struct dasd_device *device;
2040         struct dasd_ccw_req *cqr;
2041         unsigned long flags;
2042         int ret;
2043
2044         device = dasd_device_from_cdev(cdev);
2045         if (IS_ERR(device))
2046                 return 0;
2047         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
2048         ret = 0;
2049         switch (event) {
2050         case CIO_GONE:
2051         case CIO_NO_PATH:
2052                 /* First of all call extended error reporting. */
2053                 dasd_eer_write(device, NULL, DASD_EER_NOPATH);
2054
2055                 if (device->state < DASD_STATE_BASIC)
2056                         break;
2057                 /* Device is active. We want to keep it. */
2058                 if (test_bit(DASD_FLAG_DSC_ERROR, &device->flags)) {
2059                         list_for_each_entry(cqr, &device->ccw_queue, list)
2060                                 if (cqr->status == DASD_CQR_IN_IO)
2061                                         cqr->status = DASD_CQR_FAILED;
2062                         device->stopped |= DASD_STOPPED_DC_EIO;
2063                 } else {
2064                         list_for_each_entry(cqr, &device->ccw_queue, list)
2065                                 if (cqr->status == DASD_CQR_IN_IO) {
2066                                         cqr->status = DASD_CQR_QUEUED;
2067                                         cqr->retries++;
2068                                 }
2069                         device->stopped |= DASD_STOPPED_DC_WAIT;
2070                         dasd_set_timer(device, 0);
2071                 }
2072                 dasd_schedule_bh(device);
2073                 ret = 1;
2074                 break;
2075         case CIO_OPER:
2076                 /* FIXME: add a sanity check. */
2077                 device->stopped &= ~(DASD_STOPPED_DC_WAIT|DASD_STOPPED_DC_EIO);
2078                 dasd_schedule_bh(device);
2079                 ret = 1;
2080                 break;
2081         }
2082         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
2083         dasd_put_device(device);
2084         return ret;
2085 }
2086
2087
2088 static int __init
2089 dasd_init(void)
2090 {
2091         int rc;
2092
2093         init_waitqueue_head(&dasd_init_waitq);
2094
2095         /* register 'common' DASD debug area, used for all DBF_XXX calls */
2096         dasd_debug_area = debug_register("dasd", 1, 2, 8 * sizeof (long));
2097         if (dasd_debug_area == NULL) {
2098                 rc = -ENOMEM;
2099                 goto failed;
2100         }
2101         debug_register_view(dasd_debug_area, &debug_sprintf_view);
2102         debug_set_level(dasd_debug_area, DBF_EMERG);
2103
2104         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
2105
2106         dasd_diag_discipline_pointer = NULL;
2107
2108         rc = dasd_devmap_init();
2109         if (rc)
2110                 goto failed;
2111         rc = dasd_gendisk_init();
2112         if (rc)
2113                 goto failed;
2114         rc = dasd_parse();
2115         if (rc)
2116                 goto failed;
2117         rc = dasd_eer_init();
2118         if (rc)
2119                 goto failed;
2120 #ifdef CONFIG_PROC_FS
2121         rc = dasd_proc_init();
2122         if (rc)
2123                 goto failed;
2124 #endif
2125
2126         return 0;
2127 failed:
2128         MESSAGE(KERN_INFO, "%s", "initialization not performed due to errors");
2129         dasd_exit();
2130         return rc;
2131 }
2132
2133 module_init(dasd_init);
2134 module_exit(dasd_exit);
2135
2136 EXPORT_SYMBOL(dasd_debug_area);
2137 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
2138
2139 EXPORT_SYMBOL(dasd_add_request_head);
2140 EXPORT_SYMBOL(dasd_add_request_tail);
2141 EXPORT_SYMBOL(dasd_cancel_req);
2142 EXPORT_SYMBOL(dasd_clear_timer);
2143 EXPORT_SYMBOL(dasd_enable_device);
2144 EXPORT_SYMBOL(dasd_int_handler);
2145 EXPORT_SYMBOL(dasd_kfree_request);
2146 EXPORT_SYMBOL(dasd_kick_device);
2147 EXPORT_SYMBOL(dasd_kmalloc_request);
2148 EXPORT_SYMBOL(dasd_schedule_bh);
2149 EXPORT_SYMBOL(dasd_set_target_state);
2150 EXPORT_SYMBOL(dasd_set_timer);
2151 EXPORT_SYMBOL(dasd_sfree_request);
2152 EXPORT_SYMBOL(dasd_sleep_on);
2153 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2154 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2155 EXPORT_SYMBOL(dasd_smalloc_request);
2156 EXPORT_SYMBOL(dasd_start_IO);
2157 EXPORT_SYMBOL(dasd_term_IO);
2158
2159 EXPORT_SYMBOL_GPL(dasd_generic_probe);
2160 EXPORT_SYMBOL_GPL(dasd_generic_remove);
2161 EXPORT_SYMBOL_GPL(dasd_generic_notify);
2162 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
2163 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
2164