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 void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
  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_LICENSE("GPL");
  47
  48 /*
  49  * SECTION: prototypes for static functions of dasd.c
  50  */
  51 static int  dasd_alloc_queue(struct dasd_device * device);
  52 static void dasd_setup_queue(struct dasd_device * device);
  53 static void dasd_free_queue(struct dasd_device * device);
  54 static void dasd_flush_request_queue(struct dasd_device *);
  55 static int dasd_flush_ccw_queue(struct dasd_device *, int);
  56 static void dasd_tasklet(struct dasd_device *);
  57 static void do_kick_device(struct work_struct *);
  58
  59 /*
  60  * SECTION: Operations on the device structure.
  61  */
  62 static wait_queue_head_t dasd_init_waitq;
  63 static wait_queue_head_t dasd_flush_wq;
  64
  65 /*
  66  * Allocate memory for a new device structure.
  67  */
  68 struct dasd_device *
  69 dasd_alloc_device(void)
  70 {
  71         struct dasd_device *device;
  72
  73         device = kzalloc(sizeof (struct dasd_device), GFP_ATOMIC);
  74         if (device == NULL)
  75                 return ERR_PTR(-ENOMEM);
  76         /* open_count = 0 means device online but not in use */
  77         atomic_set(&device->open_count, -1);
  78
  79         /* Get two pages for normal block device operations. */
  80         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
  81         if (device->ccw_mem == NULL) {
  82                 kfree(device);
  83                 return ERR_PTR(-ENOMEM);
  84         }
  85         /* Get one page for error recovery. */
  86         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
  87         if (device->erp_mem == NULL) {
  88                 free_pages((unsigned long) device->ccw_mem, 1);
  89                 kfree(device);
  90                 return ERR_PTR(-ENOMEM);
  91         }
  92
  93         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
  94         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
  95         spin_lock_init(&device->mem_lock);
  96         spin_lock_init(&device->request_queue_lock);
  97         atomic_set (&device->tasklet_scheduled, 0);
  98         tasklet_init(&device->tasklet,
  99                      (void (*)(unsigned long)) dasd_tasklet,
 100                      (unsigned long) device);
 101         INIT_LIST_HEAD(&device->ccw_queue);
 102         init_timer(&device->timer);
 103         INIT_WORK(&device->kick_work, do_kick_device);
 104         device->state = DASD_STATE_NEW;
 105         device->target = DASD_STATE_NEW;
 106
 107         return device;
 108 }
 109
 110 /*
 111  * Free memory of a device structure.
 112  */
 113 void
 114 dasd_free_device(struct dasd_device *device)
 115 {
 116         kfree(device->private);
 117         free_page((unsigned long) device->erp_mem);
 118         free_pages((unsigned long) device->ccw_mem, 1);
 119         kfree(device);
 120 }
 121
 122 /*
 123  * Make a new device known to the system.
 124  */
 125 static int
 126 dasd_state_new_to_known(struct dasd_device *device)
 127 {
 128         int rc;
 129
 130         /*
 131          * As long as the device is not in state DASD_STATE_NEW we want to
 132          * keep the reference count > 0.
 133          */
 134         dasd_get_device(device);
 135
 136         rc = dasd_alloc_queue(device);
 137         if (rc) {
 138                 dasd_put_device(device);
 139                 return rc;
 140         }
 141
 142         device->state = DASD_STATE_KNOWN;
 143         return 0;
 144 }
 145
 146 /*
 147  * Let the system forget about a device.
 148  */
 149 static int
 150 dasd_state_known_to_new(struct dasd_device * device)
 151 {
 152         /* Disable extended error reporting for this device. */
 153         dasd_eer_disable(device);
 154         /* Forget the discipline information. */
 155         if (device->discipline)
 156                 module_put(device->discipline->owner);
 157         device->discipline = NULL;
 158         if (device->base_discipline)
 159                 module_put(device->base_discipline->owner);
 160         device->base_discipline = NULL;
 161         device->state = DASD_STATE_NEW;
 162
 163         dasd_free_queue(device);
 164
 165         /* Give up reference we took in dasd_state_new_to_known. */
 166         dasd_put_device(device);
 167         return 0;
 168 }
 169
 170 /*
 171  * Request the irq line for the device.
 172  */
 173 static int
 174 dasd_state_known_to_basic(struct dasd_device * device)
 175 {
 176         int rc;
 177
 178         /* Allocate and register gendisk structure. */
 179         rc = dasd_gendisk_alloc(device);
 180         if (rc)
 181                 return rc;
 182
 183         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 184         device->debug_area = debug_register(device->cdev->dev.bus_id, 1, 2,
 185                                             8 * sizeof (long));
 186         debug_register_view(device->debug_area, &debug_sprintf_view);
 187         debug_set_level(device->debug_area, DBF_WARNING);
 188         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 189
 190         device->state = DASD_STATE_BASIC;
 191         return 0;
 192 }
 193
 194 /*
 195  * Release the irq line for the device. Terminate any running i/o.
 196  */
 197 static int
 198 dasd_state_basic_to_known(struct dasd_device * device)
 199 {
 200         int rc;
 201
 202         dasd_gendisk_free(device);
 203         rc = dasd_flush_ccw_queue(device, 1);
 204         if (rc)
 205                 return rc;
 206         dasd_clear_timer(device);
 207
 208         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
 209         if (device->debug_area != NULL) {
 210                 debug_unregister(device->debug_area);
 211                 device->debug_area = NULL;
 212         }
 213         device->state = DASD_STATE_KNOWN;
 214         return 0;
 215 }
 216
 217 /*
 218  * Do the initial analysis. The do_analysis function may return
 219  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 220  * until the discipline decides to continue the startup sequence
 221  * by calling the function dasd_change_state. The eckd disciplines
 222  * uses this to start a ccw that detects the format. The completion
 223  * interrupt for this detection ccw uses the kernel event daemon to
 224  * trigger the call to dasd_change_state. All this is done in the
 225  * discipline code, see dasd_eckd.c.
 226  * After the analysis ccw is done (do_analysis returned 0) the block
 227  * device is setup.
 228  * In case the analysis returns an error, the device setup is stopped
 229  * (a fake disk was already added to allow formatting).
 230  */
 231 static int
 232 dasd_state_basic_to_ready(struct dasd_device * device)
 233 {
 234         int rc;
 235
 236         rc = 0;
 237         if (device->discipline->do_analysis != NULL)
 238                 rc = device->discipline->do_analysis(device);
 239         if (rc) {
 240                 if (rc != -EAGAIN)
 241                         device->state = DASD_STATE_UNFMT;
 242                 return rc;
 243         }
 244         /* make disk known with correct capacity */
 245         dasd_setup_queue(device);
 246         set_capacity(device->gdp, device->blocks << device->s2b_shift);
 247         device->state = DASD_STATE_READY;
 248         rc = dasd_scan_partitions(device);
 249         if (rc)
 250                 device->state = DASD_STATE_BASIC;
 251         return rc;
 252 }
 253
 254 /*
 255  * Remove device from block device layer. Destroy dirty buffers.
 256  * Forget format information. Check if the target level is basic
 257  * and if it is create fake disk for formatting.
 258  */
 259 static int
 260 dasd_state_ready_to_basic(struct dasd_device * device)
 261 {
 262         int rc;
 263
 264         rc = dasd_flush_ccw_queue(device, 0);
 265         if (rc)
 266                 return rc;
 267         dasd_destroy_partitions(device);
 268         dasd_flush_request_queue(device);
 269         device->blocks = 0;
 270         device->bp_block = 0;
 271         device->s2b_shift = 0;
 272         device->state = DASD_STATE_BASIC;
 273         return 0;
 274 }
 275
 276 /*
 277  * Back to basic.
 278  */
 279 static int
 280 dasd_state_unfmt_to_basic(struct dasd_device * device)
 281 {
 282         device->state = DASD_STATE_BASIC;
 283         return 0;
 284 }
 285
 286 /*
 287  * Make the device online and schedule the bottom half to start
 288  * the requeueing of requests from the linux request queue to the
 289  * ccw queue.
 290  */
 291 static int
 292 dasd_state_ready_to_online(struct dasd_device * device)
 293 {
 294         device->state = DASD_STATE_ONLINE;
 295         dasd_schedule_bh(device);
 296         return 0;
 297 }
 298
 299 /*
 300  * Stop the requeueing of requests again.
 301  */
 302 static int
 303 dasd_state_online_to_ready(struct dasd_device * device)
 304 {
 305         device->state = DASD_STATE_READY;
 306         return 0;
 307 }
 308
 309 /*
 310  * Device startup state changes.
 311  */
 312 static int
 313 dasd_increase_state(struct dasd_device *device)
 314 {
 315         int rc;
 316
 317         rc = 0;
 318         if (device->state == DASD_STATE_NEW &&
 319             device->target >= DASD_STATE_KNOWN)
 320                 rc = dasd_state_new_to_known(device);
 321
 322         if (!rc &&
 323             device->state == DASD_STATE_KNOWN &&
 324             device->target >= DASD_STATE_BASIC)
 325                 rc = dasd_state_known_to_basic(device);
 326
 327         if (!rc &&
 328             device->state == DASD_STATE_BASIC &&
 329             device->target >= DASD_STATE_READY)
 330                 rc = dasd_state_basic_to_ready(device);
 331
 332         if (!rc &&
 333             device->state == DASD_STATE_UNFMT &&
 334             device->target > DASD_STATE_UNFMT)
 335                 rc = -EPERM;
 336
 337         if (!rc &&
 338             device->state == DASD_STATE_READY &&
 339             device->target >= DASD_STATE_ONLINE)
 340                 rc = dasd_state_ready_to_online(device);
 341
 342         return rc;
 343 }
 344
 345 /*
 346  * Device shutdown state changes.
 347  */
 348 static int
 349 dasd_decrease_state(struct dasd_device *device)
 350 {
 351         int rc;
 352
 353         rc = 0;
 354         if (device->state == DASD_STATE_ONLINE &&
 355             device->target <= DASD_STATE_READY)
 356                 rc = dasd_state_online_to_ready(device);
 357
 358         if (!rc &&
 359             device->state == DASD_STATE_READY &&
 360             device->target <= DASD_STATE_BASIC)
 361                 rc = dasd_state_ready_to_basic(device);
 362
 363         if (!rc &&
 364             device->state == DASD_STATE_UNFMT &&
 365             device->target <= DASD_STATE_BASIC)
 366                 rc = dasd_state_unfmt_to_basic(device);
 367
 368         if (!rc &&
 369             device->state == DASD_STATE_BASIC &&
 370             device->target <= DASD_STATE_KNOWN)
 371                 rc = dasd_state_basic_to_known(device);
 372
 373         if (!rc &&
 374             device->state == DASD_STATE_KNOWN &&
 375             device->target <= DASD_STATE_NEW)
 376                 rc = dasd_state_known_to_new(device);
 377
 378         return rc;
 379 }
 380
 381 /*
 382  * This is the main startup/shutdown routine.
 383  */
 384 static void
 385 dasd_change_state(struct dasd_device *device)
 386 {
 387         int rc;
 388
 389         if (device->state == device->target)
 390                 /* Already where we want to go today... */
 391                 return;
 392         if (device->state < device->target)
 393                 rc = dasd_increase_state(device);
 394         else
 395                 rc = dasd_decrease_state(device);
 396         if (rc && rc != -EAGAIN)
 397                 device->target = device->state;
 398
 399         if (device->state == device->target)
 400                 wake_up(&dasd_init_waitq);
 401 }
 402
 403 /*
 404  * Kick starter for devices that did not complete the startup/shutdown
 405  * procedure or were sleeping because of a pending state.
 406  * dasd_kick_device will schedule a call do do_kick_device to the kernel
 407  * event daemon.
 408  */
 409 static void
 410 do_kick_device(struct work_struct *work)
 411 {
 412         struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
 413         dasd_change_state(device);
 414         dasd_schedule_bh(device);
 415         dasd_put_device(device);
 416 }
 417
 418 void
 419 dasd_kick_device(struct dasd_device *device)
 420 {
 421         dasd_get_device(device);
 422         /* queue call to dasd_kick_device to the kernel event daemon. */
 423         schedule_work(&device->kick_work);
 424 }
 425
 426 /*
 427  * Set the target state for a device and starts the state change.
 428  */
 429 void
 430 dasd_set_target_state(struct dasd_device *device, int target)
 431 {
 432         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 433         if (dasd_probeonly && target > DASD_STATE_READY)
 434                 target = DASD_STATE_READY;
 435         if (device->target != target) {
 436                 if (device->state == target)
 437                         wake_up(&dasd_init_waitq);
 438                 device->target = target;
 439         }
 440         if (device->state != device->target)
 441                 dasd_change_state(device);
 442 }
 443
 444 /*
 445  * Enable devices with device numbers in [from..to].
 446  */
 447 static inline int
 448 _wait_for_device(struct dasd_device *device)
 449 {
 450         return (device->state == device->target);
 451 }
 452
 453 void
 454 dasd_enable_device(struct dasd_device *device)
 455 {
 456         dasd_set_target_state(device, DASD_STATE_ONLINE);
 457         if (device->state <= DASD_STATE_KNOWN)
 458                 /* No discipline for device found. */
 459                 dasd_set_target_state(device, DASD_STATE_NEW);
 460         /* Now wait for the devices to come up. */
 461         wait_event(dasd_init_waitq, _wait_for_device(device));
 462 }
 463
 464 /*
 465  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 466  */
 467 #ifdef CONFIG_DASD_PROFILE
 468
 469 struct dasd_profile_info_t dasd_global_profile;
 470 unsigned int dasd_profile_level = DASD_PROFILE_OFF;
 471
 472 /*
 473  * Increments counter in global and local profiling structures.
 474  */
 475 #define dasd_profile_counter(value, counter, device) \
 476 { \
 477         int index; \
 478         for (index = 0; index < 31 && value >> (2+index); index++); \
 479         dasd_global_profile.counter[index]++; \
 480         device->profile.counter[index]++; \
 481 }
 482
 483 /*
 484  * Add profiling information for cqr before execution.
 485  */
 486 static void
 487 dasd_profile_start(struct dasd_device *device, struct dasd_ccw_req * cqr,
 488                    struct request *req)
 489 {
 490         struct list_head *l;
 491         unsigned int counter;
 492
 493         if (dasd_profile_level != DASD_PROFILE_ON)
 494                 return;
 495
 496         /* count the length of the chanq for statistics */
 497         counter = 0;
 498         list_for_each(l, &device->ccw_queue)
 499                 if (++counter >= 31)
 500                         break;
 501         dasd_global_profile.dasd_io_nr_req[counter]++;
 502         device->profile.dasd_io_nr_req[counter]++;
 503 }
 504
 505 /*
 506  * Add profiling information for cqr after execution.
 507  */
 508 static void
 509 dasd_profile_end(struct dasd_device *device, struct dasd_ccw_req * cqr,
 510                  struct request *req)
 511 {
 512         long strtime, irqtime, endtime, tottime;        /* in microseconds */
 513         long tottimeps, sectors;
 514
 515         if (dasd_profile_level != DASD_PROFILE_ON)
 516                 return;
 517
 518         sectors = req->nr_sectors;
 519         if (!cqr->buildclk || !cqr->startclk ||
 520             !cqr->stopclk || !cqr->endclk ||
 521             !sectors)
 522                 return;
 523
 524         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 525         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 526         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 527         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 528         tottimeps = tottime / sectors;
 529
 530         if (!dasd_global_profile.dasd_io_reqs)
 531                 memset(&dasd_global_profile, 0,
 532                        sizeof (struct dasd_profile_info_t));
 533         dasd_global_profile.dasd_io_reqs++;
 534         dasd_global_profile.dasd_io_sects += sectors;
 535
 536         if (!device->profile.dasd_io_reqs)
 537                 memset(&device->profile, 0,
 538                        sizeof (struct dasd_profile_info_t));
 539         device->profile.dasd_io_reqs++;
 540         device->profile.dasd_io_sects += sectors;
 541
 542         dasd_profile_counter(sectors, dasd_io_secs, device);
 543         dasd_profile_counter(tottime, dasd_io_times, device);
 544         dasd_profile_counter(tottimeps, dasd_io_timps, device);
 545         dasd_profile_counter(strtime, dasd_io_time1, device);
 546         dasd_profile_counter(irqtime, dasd_io_time2, device);
 547         dasd_profile_counter(irqtime / sectors, dasd_io_time2ps, device);
 548         dasd_profile_counter(endtime, dasd_io_time3, device);
 549 }
 550 #else
 551 #define dasd_profile_start(device, cqr, req) do {} while (0)
 552 #define dasd_profile_end(device, cqr, req) do {} while (0)
 553 #endif                          /* CONFIG_DASD_PROFILE */
 554
 555 /*
 556  * Allocate memory for a channel program with 'cplength' channel
 557  * command words and 'datasize' additional space. There are two
 558  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
 559  * memory and 2) dasd_smalloc_request uses the static ccw memory
 560  * that gets allocated for each device.
 561  */
 562 struct dasd_ccw_req *
 563 dasd_kmalloc_request(char *magic, int cplength, int datasize,
 564                    struct dasd_device * device)
 565 {
 566         struct dasd_ccw_req *cqr;
 567
 568         /* Sanity checks */
 569         BUG_ON( magic == NULL || datasize > PAGE_SIZE ||
 570              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
 571
 572         cqr = kzalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
 573         if (cqr == NULL)
 574                 return ERR_PTR(-ENOMEM);
 575         cqr->cpaddr = NULL;
 576         if (cplength > 0) {
 577                 cqr->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
 578                                       GFP_ATOMIC | GFP_DMA);
 579                 if (cqr->cpaddr == NULL) {
 580                         kfree(cqr);
 581                         return ERR_PTR(-ENOMEM);
 582                 }
 583         }
 584         cqr->data = NULL;
 585         if (datasize > 0) {
 586                 cqr->data = kzalloc(datasize, GFP_ATOMIC | GFP_DMA);
 587                 if (cqr->data == NULL) {
 588                         kfree(cqr->cpaddr);
 589                         kfree(cqr);
 590                         return ERR_PTR(-ENOMEM);
 591                 }
 592         }
 593         strncpy((char *) &cqr->magic, magic, 4);
 594         ASCEBC((char *) &cqr->magic, 4);
 595         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
 596         dasd_get_device(device);
 597         return cqr;
 598 }
 599
 600 struct dasd_ccw_req *
 601 dasd_smalloc_request(char *magic, int cplength, int datasize,
 602                    struct dasd_device * device)
 603 {
 604         unsigned long flags;
 605         struct dasd_ccw_req *cqr;
 606         char *data;
 607         int size;
 608
 609         /* Sanity checks */
 610         BUG_ON( magic == NULL || datasize > PAGE_SIZE ||
 611              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
 612
 613         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
 614         if (cplength > 0)
 615                 size += cplength * sizeof(struct ccw1);
 616         if (datasize > 0)
 617                 size += datasize;
 618         spin_lock_irqsave(&device->mem_lock, flags);
 619         cqr = (struct dasd_ccw_req *)
 620                 dasd_alloc_chunk(&device->ccw_chunks, size);
 621         spin_unlock_irqrestore(&device->mem_lock, flags);
 622         if (cqr == NULL)
 623                 return ERR_PTR(-ENOMEM);
 624         memset(cqr, 0, sizeof(struct dasd_ccw_req));
 625         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
 626         cqr->cpaddr = NULL;
 627         if (cplength > 0) {
 628                 cqr->cpaddr = (struct ccw1 *) data;
 629                 data += cplength*sizeof(struct ccw1);
 630                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
 631         }
 632         cqr->data = NULL;
 633         if (datasize > 0) {
 634                 cqr->data = data;
 635                 memset(cqr->data, 0, datasize);
 636         }
 637         strncpy((char *) &cqr->magic, magic, 4);
 638         ASCEBC((char *) &cqr->magic, 4);
 639         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
 640         dasd_get_device(device);
 641         return cqr;
 642 }
 643
 644 /*
 645  * Free memory of a channel program. This function needs to free all the
 646  * idal lists that might have been created by dasd_set_cda and the
 647  * struct dasd_ccw_req itself.
 648  */
 649 void
 650 dasd_kfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
 651 {
 652 #ifdef CONFIG_64BIT
 653         struct ccw1 *ccw;
 654
 655         /* Clear any idals used for the request. */
 656         ccw = cqr->cpaddr;
 657         do {
 658                 clear_normalized_cda(ccw);
 659         } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
 660 #endif
 661         kfree(cqr->cpaddr);
 662         kfree(cqr->data);
 663         kfree(cqr);
 664         dasd_put_device(device);
 665 }
 666
 667 void
 668 dasd_sfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
 669 {
 670         unsigned long flags;
 671
 672         spin_lock_irqsave(&device->mem_lock, flags);
 673         dasd_free_chunk(&device->ccw_chunks, cqr);
 674         spin_unlock_irqrestore(&device->mem_lock, flags);
 675         dasd_put_device(device);
 676 }
 677
 678 /*
 679  * Check discipline magic in cqr.
 680  */
 681 static inline int
 682 dasd_check_cqr(struct dasd_ccw_req *cqr)
 683 {
 684         struct dasd_device *device;
 685
 686         if (cqr == NULL)
 687                 return -EINVAL;
 688         device = cqr->device;
 689         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
 690                 DEV_MESSAGE(KERN_WARNING, device,
 691                             " dasd_ccw_req 0x%08x magic doesn't match"
 692                             " discipline 0x%08x",
 693                             cqr->magic,
 694                             *(unsigned int *) device->discipline->name);
 695                 return -EINVAL;
 696         }
 697         return 0;
 698 }
 699
 700 /*
 701  * Terminate the current i/o and set the request to clear_pending.
 702  * Timer keeps device runnig.
 703  * ccw_device_clear can fail if the i/o subsystem
 704  * is in a bad mood.
 705  */
 706 int
 707 dasd_term_IO(struct dasd_ccw_req * cqr)
 708 {
 709         struct dasd_device *device;
 710         int retries, rc;
 711
 712         /* Check the cqr */
 713         rc = dasd_check_cqr(cqr);
 714         if (rc)
 715                 return rc;
 716         retries = 0;
 717         device = (struct dasd_device *) cqr->device;
 718         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
 719                 rc = ccw_device_clear(device->cdev, (long) cqr);
 720                 switch (rc) {
 721                 case 0: /* termination successful */
 722                         cqr->retries--;
 723                         cqr->status = DASD_CQR_CLEAR;
 724                         cqr->stopclk = get_clock();
 725                         cqr->starttime = 0;
 726                         DBF_DEV_EVENT(DBF_DEBUG, device,
 727                                       "terminate cqr %p successful",
 728                                       cqr);
 729                         break;
 730                 case -ENODEV:
 731                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 732                                       "device gone, retry");
 733                         break;
 734                 case -EIO:
 735                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 736                                       "I/O error, retry");
 737                         break;
 738                 case -EINVAL:
 739                 case -EBUSY:
 740                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 741                                       "device busy, retry later");
 742                         break;
 743                 default:
 744                         DEV_MESSAGE(KERN_ERR, device,
 745                                     "line %d unknown RC=%d, please "
 746                                     "report to linux390@de.ibm.com",
 747                                     __LINE__, rc);
 748                         BUG();
 749                         break;
 750                 }
 751                 retries++;
 752         }
 753         dasd_schedule_bh(device);
 754         return rc;
 755 }
 756
 757 /*
 758  * Start the i/o. This start_IO can fail if the channel is really busy.
 759  * In that case set up a timer to start the request later.
 760  */
 761 int
 762 dasd_start_IO(struct dasd_ccw_req * cqr)
 763 {
 764         struct dasd_device *device;
 765         int rc;
 766
 767         /* Check the cqr */
 768         rc = dasd_check_cqr(cqr);
 769         if (rc)
 770                 return rc;
 771         device = (struct dasd_device *) cqr->device;
 772         if (cqr->retries < 0) {
 773                 DEV_MESSAGE(KERN_DEBUG, device,
 774                             "start_IO: request %p (%02x/%i) - no retry left.",
 775                             cqr, cqr->status, cqr->retries);
 776                 cqr->status = DASD_CQR_FAILED;
 777                 return -EIO;
 778         }
 779         cqr->startclk = get_clock();
 780         cqr->starttime = jiffies;
 781         cqr->retries--;
 782         rc = ccw_device_start(device->cdev, cqr->cpaddr, (long) cqr,
 783                               cqr->lpm, 0);
 784         switch (rc) {
 785         case 0:
 786                 cqr->status = DASD_CQR_IN_IO;
 787                 DBF_DEV_EVENT(DBF_DEBUG, device,
 788                               "start_IO: request %p started successful",
 789                               cqr);
 790                 break;
 791         case -EBUSY:
 792                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 793                               "start_IO: device busy, retry later");
 794                 break;
 795         case -ETIMEDOUT:
 796                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 797                               "start_IO: request timeout, retry later");
 798                 break;
 799         case -EACCES:
 800                 /* -EACCES indicates that the request used only a
 801                  * subset of the available pathes and all these
 802                  * pathes are gone.
 803                  * Do a retry with all available pathes.
 804                  */
 805                 cqr->lpm = LPM_ANYPATH;
 806                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 807                               "start_IO: selected pathes gone,"
 808                               " retry on all pathes");
 809                 break;
 810         case -ENODEV:
 811         case -EIO:
 812                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 813                               "start_IO: device gone, retry");
 814                 break;
 815         default:
 816                 DEV_MESSAGE(KERN_ERR, device,
 817                             "line %d unknown RC=%d, please report"
 818                             " to linux390@de.ibm.com", __LINE__, rc);
 819                 BUG();
 820                 break;
 821         }
 822         return rc;
 823 }
 824
 825 /*
 826  * Timeout function for dasd devices. This is used for different purposes
 827  *  1) missing interrupt handler for normal operation
 828  *  2) delayed start of request where start_IO failed with -EBUSY
 829  *  3) timeout for missing state change interrupts
 830  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
 831  * DASD_CQR_QUEUED for 2) and 3).
 832  */
 833 static void
 834 dasd_timeout_device(unsigned long ptr)
 835 {
 836         unsigned long flags;
 837         struct dasd_device *device;
 838
 839         device = (struct dasd_device *) ptr;
 840         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
 841         /* re-activate request queue */
 842         device->stopped &= ~DASD_STOPPED_PENDING;
 843         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
 844         dasd_schedule_bh(device);
 845 }
 846
 847 /*
 848  * Setup timeout for a device in jiffies.
 849  */
 850 void
 851 dasd_set_timer(struct dasd_device *device, int expires)
 852 {
 853         if (expires == 0) {
 854                 if (timer_pending(&device->timer))
 855                         del_timer(&device->timer);
 856                 return;
 857         }
 858         if (timer_pending(&device->timer)) {
 859                 if (mod_timer(&device->timer, jiffies + expires))
 860                         return;
 861         }
 862         device->timer.function = dasd_timeout_device;
 863         device->timer.data = (unsigned long) device;
 864         device->timer.expires = jiffies + expires;
 865         add_timer(&device->timer);
 866 }
 867
 868 /*
 869  * Clear timeout for a device.
 870  */
 871 void
 872 dasd_clear_timer(struct dasd_device *device)
 873 {
 874         if (timer_pending(&device->timer))
 875                 del_timer(&device->timer);
 876 }
 877
 878 static void
 879 dasd_handle_killed_request(struct ccw_device *cdev, unsigned long intparm)
 880 {
 881         struct dasd_ccw_req *cqr;
 882         struct dasd_device *device;
 883
 884         cqr = (struct dasd_ccw_req *) intparm;
 885         if (cqr->status != DASD_CQR_IN_IO) {
 886                 MESSAGE(KERN_DEBUG,
 887                         "invalid status in handle_killed_request: "
 888                         "bus_id %s, status %02x",
 889                         cdev->dev.bus_id, cqr->status);
 890                 return;
 891         }
 892
 893         device = (struct dasd_device *) cqr->device;
 894         if (device == NULL ||
 895             device != dasd_device_from_cdev_locked(cdev) ||
 896             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
 897                 MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
 898                         cdev->dev.bus_id);
 899                 return;
 900         }
 901
 902         /* Schedule request to be retried. */
 903         cqr->status = DASD_CQR_QUEUED;
 904
 905         dasd_clear_timer(device);
 906         dasd_schedule_bh(device);
 907         dasd_put_device(device);
 908 }
 909
 910 static void
 911 dasd_handle_state_change_pending(struct dasd_device *device)
 912 {
 913         struct dasd_ccw_req *cqr;
 914         struct list_head *l, *n;
 915
 916         /* First of all start sense subsystem status request. */
 917         dasd_eer_snss(device);
 918
 919         device->stopped &= ~DASD_STOPPED_PENDING;
 920
 921         /* restart all 'running' IO on queue */
 922         list_for_each_safe(l, n, &device->ccw_queue) {
 923                 cqr = list_entry(l, struct dasd_ccw_req, list);
 924                 if (cqr->status == DASD_CQR_IN_IO) {
 925                         cqr->status = DASD_CQR_QUEUED;
 926                 }
 927         }
 928         dasd_clear_timer(device);
 929         dasd_schedule_bh(device);
 930 }
 931
 932 /*
 933  * Interrupt handler for "normal" ssch-io based dasd devices.
 934  */
 935 void
 936 dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
 937                  struct irb *irb)
 938 {
 939         struct dasd_ccw_req *cqr, *next;
 940         struct dasd_device *device;
 941         unsigned long long now;
 942         int expires;
 943         dasd_era_t era;
 944         char mask;
 945
 946         if (IS_ERR(irb)) {
 947                 switch (PTR_ERR(irb)) {
 948                 case -EIO:
 949                         dasd_handle_killed_request(cdev, intparm);
 950                         break;
 951                 case -ETIMEDOUT:
 952                         printk(KERN_WARNING"%s(%s): request timed out\n",
 953                                __FUNCTION__, cdev->dev.bus_id);
 954                         //FIXME - dasd uses own timeout interface...
 955                         break;
 956                 default:
 957                         printk(KERN_WARNING"%s(%s): unknown error %ld\n",
 958                                __FUNCTION__, cdev->dev.bus_id, PTR_ERR(irb));
 959                 }
 960                 return;
 961         }
 962
 963         now = get_clock();
 964
 965         DBF_EVENT(DBF_ERR, "Interrupt: bus_id %s CS/DS %04x ip %08x",
 966                   cdev->dev.bus_id, ((irb->scsw.cstat<<8)|irb->scsw.dstat),
 967                   (unsigned int) intparm);
 968
 969         /* first of all check for state change pending interrupt */
 970         mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP;
 971         if ((irb->scsw.dstat & mask) == mask) {
 972                 device = dasd_device_from_cdev_locked(cdev);
 973                 if (!IS_ERR(device)) {
 974                         dasd_handle_state_change_pending(device);
 975                         dasd_put_device(device);
 976                 }
 977                 return;
 978         }
 979
 980         cqr = (struct dasd_ccw_req *) intparm;
 981
 982         /* check for unsolicited interrupts */
 983         if (cqr == NULL) {
 984                 MESSAGE(KERN_DEBUG,
 985                         "unsolicited interrupt received: bus_id %s",
 986                         cdev->dev.bus_id);
 987                 return;
 988         }
 989
 990         device = (struct dasd_device *) cqr->device;
 991         if (device == NULL ||
 992             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
 993                 MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
 994                         cdev->dev.bus_id);
 995                 return;
 996         }
 997
 998         /* Check for clear pending */
 999         if (cqr->status == DASD_CQR_CLEAR &&
1000             irb->scsw.fctl & SCSW_FCTL_CLEAR_FUNC) {
1001                 cqr->status = DASD_CQR_QUEUED;
1002                 dasd_clear_timer(device);
1003                 wake_up(&dasd_flush_wq);
1004                 dasd_schedule_bh(device);
1005                 return;
1006         }
1007
1008         /* check status - the request might have been killed by dyn detach */
1009         if (cqr->status != DASD_CQR_IN_IO) {
1010                 MESSAGE(KERN_DEBUG,
1011                         "invalid status: bus_id %s, status %02x",
1012                         cdev->dev.bus_id, cqr->status);
1013                 return;
1014         }
1015         DBF_DEV_EVENT(DBF_DEBUG, device, "Int: CS/DS 0x%04x for cqr %p",
1016                       ((irb->scsw.cstat << 8) | irb->scsw.dstat), cqr);
1017
1018         /* Find out the appropriate era_action. */
1019         if (irb->scsw.fctl & SCSW_FCTL_HALT_FUNC)
1020                 era = dasd_era_fatal;
1021         else if (irb->scsw.dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1022                  irb->scsw.cstat == 0 &&
1023                  !irb->esw.esw0.erw.cons)
1024                 era = dasd_era_none;
1025         else if (irb->esw.esw0.erw.cons)
1026                 era = device->discipline->examine_error(cqr, irb);
1027         else
1028                 era = dasd_era_recover;
1029
1030         DBF_DEV_EVENT(DBF_DEBUG, device, "era_code %d", era);
1031         expires = 0;
1032         if (era == dasd_era_none) {
1033                 cqr->status = DASD_CQR_DONE;
1034                 cqr->stopclk = now;
1035                 /* Start first request on queue if possible -> fast_io. */
1036                 if (cqr->list.next != &device->ccw_queue) {
1037                         next = list_entry(cqr->list.next,
1038                                           struct dasd_ccw_req, list);
1039                         if ((next->status == DASD_CQR_QUEUED) &&
1040                             (!device->stopped)) {
1041                                 if (device->discipline->start_IO(next) == 0)
1042                                         expires = next->expires;
1043                                 else
1044                                         DEV_MESSAGE(KERN_DEBUG, device, "%s",
1045                                                     "Interrupt fastpath "
1046                                                     "failed!");
1047                         }
1048                 }
1049         } else {                /* error */
1050                 memcpy(&cqr->irb, irb, sizeof (struct irb));
1051                 if (device->features & DASD_FEATURE_ERPLOG) {
1052                         /* dump sense data */
1053                         dasd_log_sense(cqr, irb);
1054                 }
1055                 switch (era) {
1056                 case dasd_era_fatal:
1057                         cqr->status = DASD_CQR_FAILED;
1058                         cqr->stopclk = now;
1059                         break;
1060                 case dasd_era_recover:
1061                         cqr->status = DASD_CQR_ERROR;
1062                         break;
1063                 default:
1064                         BUG();
1065                 }
1066         }
1067         if (expires != 0)
1068                 dasd_set_timer(device, expires);
1069         else
1070                 dasd_clear_timer(device);
1071         dasd_schedule_bh(device);
1072 }
1073
1074 /*
1075  * posts the buffer_cache about a finalized request
1076  */
1077 static inline void
1078 dasd_end_request(struct request *req, int uptodate)
1079 {
1080         if (end_that_request_first(req, uptodate, req->hard_nr_sectors))
1081                 BUG();
1082         add_disk_randomness(req->rq_disk);
1083         end_that_request_last(req, uptodate);
1084 }
1085
1086 /*
1087  * Process finished error recovery ccw.
1088  */
1089 static inline void
1090 __dasd_process_erp(struct dasd_device *device, struct dasd_ccw_req *cqr)
1091 {
1092         dasd_erp_fn_t erp_fn;
1093
1094         if (cqr->status == DASD_CQR_DONE)
1095                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
1096         else
1097                 DEV_MESSAGE(KERN_ERR, device, "%s", "ERP unsuccessful");
1098         erp_fn = device->discipline->erp_postaction(cqr);
1099         erp_fn(cqr);
1100 }
1101
1102 /*
1103  * Process ccw request queue.
1104  */
1105 static void
1106 __dasd_process_ccw_queue(struct dasd_device * device,
1107                          struct list_head *final_queue)
1108 {
1109         struct list_head *l, *n;
1110         struct dasd_ccw_req *cqr;
1111         dasd_erp_fn_t erp_fn;
1112
1113 restart:
1114         /* Process request with final status. */
1115         list_for_each_safe(l, n, &device->ccw_queue) {
1116                 cqr = list_entry(l, struct dasd_ccw_req, list);
1117                 /* Stop list processing at the first non-final request. */
1118                 if (cqr->status != DASD_CQR_DONE &&
1119                     cqr->status != DASD_CQR_FAILED &&
1120                     cqr->status != DASD_CQR_ERROR)
1121                         break;
1122                 /*  Process requests with DASD_CQR_ERROR */
1123                 if (cqr->status == DASD_CQR_ERROR) {
1124                         if (cqr->irb.scsw.fctl & SCSW_FCTL_HALT_FUNC) {
1125                                 cqr->status = DASD_CQR_FAILED;
1126                                 cqr->stopclk = get_clock();
1127                         } else {
1128                                 if (cqr->irb.esw.esw0.erw.cons &&
1129                                     test_bit(DASD_CQR_FLAGS_USE_ERP,
1130                                              &cqr->flags)) {
1131                                         erp_fn = device->discipline->
1132                                                 erp_action(cqr);
1133                                         erp_fn(cqr);
1134                                 } else
1135                                         dasd_default_erp_action(cqr);
1136                         }
1137                         goto restart;
1138                 }
1139
1140                 /* First of all call extended error reporting. */
1141                 if (dasd_eer_enabled(device) &&
1142                     cqr->status == DASD_CQR_FAILED) {
1143                         dasd_eer_write(device, cqr, DASD_EER_FATALERROR);
1144
1145                         /* restart request  */
1146                         cqr->status = DASD_CQR_QUEUED;
1147                         cqr->retries = 255;
1148                         device->stopped |= DASD_STOPPED_QUIESCE;
1149                         goto restart;
1150                 }
1151
1152                 /* Process finished ERP request. */
1153                 if (cqr->refers) {
1154                         __dasd_process_erp(device, cqr);
1155                         goto restart;
1156                 }
1157
1158                 /* Rechain finished requests to final queue */
1159                 cqr->endclk = get_clock();
1160                 list_move_tail(&cqr->list, final_queue);
1161         }
1162 }
1163
1164 static void
1165 dasd_end_request_cb(struct dasd_ccw_req * cqr, void *data)
1166 {
1167         struct request *req;
1168         struct dasd_device *device;
1169         int status;
1170
1171         req = (struct request *) data;
1172         device = cqr->device;
1173         dasd_profile_end(device, cqr, req);
1174         status = cqr->device->discipline->free_cp(cqr,req);
1175         spin_lock_irq(&device->request_queue_lock);
1176         dasd_end_request(req, status);
1177         spin_unlock_irq(&device->request_queue_lock);
1178 }
1179
1180
1181 /*
1182  * Fetch requests from the block device queue.
1183  */
1184 static void
1185 __dasd_process_blk_queue(struct dasd_device * device)
1186 {
1187         request_queue_t *queue;
1188         struct request *req;
1189         struct dasd_ccw_req *cqr;
1190         int nr_queued;
1191
1192         queue = device->request_queue;
1193         /* No queue ? Then there is nothing to do. */
1194         if (queue == NULL)
1195                 return;
1196
1197         /*
1198          * We requeue request from the block device queue to the ccw
1199          * queue only in two states. In state DASD_STATE_READY the
1200          * partition detection is done and we need to requeue requests
1201          * for that. State DASD_STATE_ONLINE is normal block device
1202          * operation.
1203          */
1204         if (device->state != DASD_STATE_READY &&
1205             device->state != DASD_STATE_ONLINE)
1206                 return;
1207         nr_queued = 0;
1208         /* Now we try to fetch requests from the request queue */
1209         list_for_each_entry(cqr, &device->ccw_queue, list)
1210                 if (cqr->status == DASD_CQR_QUEUED)
1211                         nr_queued++;
1212         while (!blk_queue_plugged(queue) &&
1213                elv_next_request(queue) &&
1214                 nr_queued < DASD_CHANQ_MAX_SIZE) {
1215                 req = elv_next_request(queue);
1216
1217                 if (device->features & DASD_FEATURE_READONLY &&
1218                     rq_data_dir(req) == WRITE) {
1219                         DBF_DEV_EVENT(DBF_ERR, device,
1220                                       "Rejecting write request %p",
1221                                       req);
1222                         blkdev_dequeue_request(req);
1223                         dasd_end_request(req, 0);
1224                         continue;
1225                 }
1226                 if (device->stopped & DASD_STOPPED_DC_EIO) {
1227                         blkdev_dequeue_request(req);
1228                         dasd_end_request(req, 0);
1229                         continue;
1230                 }
1231                 cqr = device->discipline->build_cp(device, req);
1232                 if (IS_ERR(cqr)) {
1233                         if (PTR_ERR(cqr) == -ENOMEM)
1234                                 break;  /* terminate request queue loop */
1235                         if (PTR_ERR(cqr) == -EAGAIN) {
1236                                 /*
1237                                  * The current request cannot be build right
1238                                  * now, we have to try later. If this request
1239                                  * is the head-of-queue we stop the device
1240                                  * for 1/2 second.
1241                                  */
1242                                 if (!list_empty(&device->ccw_queue))
1243                                         break;
1244                                 device->stopped |= DASD_STOPPED_PENDING;
1245                                 dasd_set_timer(device, HZ/2);
1246                                 break;
1247                         }
1248                         DBF_DEV_EVENT(DBF_ERR, device,
1249                                       "CCW creation failed (rc=%ld) "
1250                                       "on request %p",
1251                                       PTR_ERR(cqr), req);
1252                         blkdev_dequeue_request(req);
1253                         dasd_end_request(req, 0);
1254                         continue;
1255                 }
1256                 cqr->callback = dasd_end_request_cb;
1257                 cqr->callback_data = (void *) req;
1258                 cqr->status = DASD_CQR_QUEUED;
1259                 blkdev_dequeue_request(req);
1260                 list_add_tail(&cqr->list, &device->ccw_queue);
1261                 dasd_profile_start(device, cqr, req);
1262                 nr_queued++;
1263         }
1264 }
1265
1266 /*
1267  * Take a look at the first request on the ccw queue and check
1268  * if it reached its expire time. If so, terminate the IO.
1269  */
1270 static void
1271 __dasd_check_expire(struct dasd_device * device)
1272 {
1273         struct dasd_ccw_req *cqr;
1274
1275         if (list_empty(&device->ccw_queue))
1276                 return;
1277         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1278         if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1279             (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1280                 if (device->discipline->term_IO(cqr) != 0) {
1281                         /* Hmpf, try again in 5 sec */
1282                         dasd_set_timer(device, 5*HZ);
1283                         DEV_MESSAGE(KERN_ERR, device,
1284                                     "internal error - timeout (%is) expired "
1285                                     "for cqr %p, termination failed, "
1286                                     "retrying in 5s",
1287                                     (cqr->expires/HZ), cqr);
1288                 } else {
1289                         DEV_MESSAGE(KERN_ERR, device,
1290                                     "internal error - timeout (%is) expired "
1291                                     "for cqr %p (%i retries left)",
1292                                     (cqr->expires/HZ), cqr, cqr->retries);
1293                 }
1294         }
1295 }
1296
1297 /*
1298  * Take a look at the first request on the ccw queue and check
1299  * if it needs to be started.
1300  */
1301 static void
1302 __dasd_start_head(struct dasd_device * device)
1303 {
1304         struct dasd_ccw_req *cqr;
1305         int rc;
1306
1307         if (list_empty(&device->ccw_queue))
1308                 return;
1309         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1310         if (cqr->status != DASD_CQR_QUEUED)
1311                 return;
1312         /* Non-temporary stop condition will trigger fail fast */
1313         if (device->stopped & ~DASD_STOPPED_PENDING &&
1314             test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
1315             (!dasd_eer_enabled(device))) {
1316                 cqr->status = DASD_CQR_FAILED;
1317                 dasd_schedule_bh(device);
1318                 return;
1319         }
1320         /* Don't try to start requests if device is stopped */
1321         if (device->stopped)
1322                 return;
1323
1324         rc = device->discipline->start_IO(cqr);
1325         if (rc == 0)
1326                 dasd_set_timer(device, cqr->expires);
1327         else if (rc == -EACCES) {
1328                 dasd_schedule_bh(device);
1329         } else
1330                 /* Hmpf, try again in 1/2 sec */
1331                 dasd_set_timer(device, 50);
1332 }
1333
1334 static inline int
1335 _wait_for_clear(struct dasd_ccw_req *cqr)
1336 {
1337         return (cqr->status == DASD_CQR_QUEUED);
1338 }
1339
1340 /*
1341  * Remove all requests from the ccw queue (all = '1') or only block device
1342  * requests in case all = '0'.
1343  * Take care of the erp-chain (chained via cqr->refers) and remove either
1344  * the whole erp-chain or none of the erp-requests.
1345  * If a request is currently running, term_IO is called and the request
1346  * is re-queued. Prior to removing the terminated request we need to wait
1347  * for the clear-interrupt.
1348  * In case termination is not possible we stop processing and just finishing
1349  * the already moved requests.
1350  */
1351 static int
1352 dasd_flush_ccw_queue(struct dasd_device * device, int all)
1353 {
1354         struct dasd_ccw_req *cqr, *orig, *n;
1355         int rc, i;
1356
1357         struct list_head flush_queue;
1358
1359         INIT_LIST_HEAD(&flush_queue);
1360         spin_lock_irq(get_ccwdev_lock(device->cdev));
1361         rc = 0;
1362 restart:
1363         list_for_each_entry_safe(cqr, n, &device->ccw_queue, list) {
1364                 /* get original request of erp request-chain */
1365                 for (orig = cqr; orig->refers != NULL; orig = orig->refers);
1366
1367                 /* Flush all request or only block device requests? */
1368                 if (all == 0 && cqr->callback != dasd_end_request_cb &&
1369                     orig->callback != dasd_end_request_cb) {
1370                         continue;
1371                 }
1372                 /* Check status and move request to flush_queue */
1373                 switch (cqr->status) {
1374                 case DASD_CQR_IN_IO:
1375                         rc = device->discipline->term_IO(cqr);
1376                         if (rc) {
1377                                 /* unable to terminate requeust */
1378                                 DEV_MESSAGE(KERN_ERR, device,
1379                                             "dasd flush ccw_queue is unable "
1380                                             " to terminate request %p",
1381                                             cqr);
1382                                 /* stop flush processing */
1383                                 goto finished;
1384                         }
1385                         break;
1386                 case DASD_CQR_QUEUED:
1387                 case DASD_CQR_ERROR:
1388                         /* set request to FAILED */
1389                         cqr->stopclk = get_clock();
1390                         cqr->status = DASD_CQR_FAILED;
1391                         break;
1392                 default: /* do not touch the others */
1393                         break;
1394                 }
1395                 /* Rechain request (including erp chain) */
1396                 for (i = 0; cqr != NULL; cqr = cqr->refers, i++) {
1397                         cqr->endclk = get_clock();
1398                         list_move_tail(&cqr->list, &flush_queue);
1399                 }
1400                 if (i > 1)
1401                         /* moved more than one request - need to restart */
1402                         goto restart;
1403         }
1404
1405 finished:
1406         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1407         /* Now call the callback function of flushed requests */
1408 restart_cb:
1409         list_for_each_entry_safe(cqr, n, &flush_queue, list) {
1410                 if (cqr->status == DASD_CQR_CLEAR) {
1411                         /* wait for clear interrupt! */
1412                         wait_event(dasd_flush_wq, _wait_for_clear(cqr));
1413                         cqr->status = DASD_CQR_FAILED;
1414                 }
1415                 /* Process finished ERP request. */
1416                 if (cqr->refers) {
1417                         __dasd_process_erp(device, cqr);
1418                         /* restart list_for_xx loop since dasd_process_erp
1419                          * might remove multiple elements */
1420                         goto restart_cb;
1421                 }
1422                 /* call the callback function */
1423                 cqr->endclk = get_clock();
1424                 if (cqr->callback != NULL)
1425                         (cqr->callback)(cqr, cqr->callback_data);
1426         }
1427         return rc;
1428 }
1429
1430 /*
1431  * Acquire the device lock and process queues for the device.
1432  */
1433 static void
1434 dasd_tasklet(struct dasd_device * device)
1435 {
1436         struct list_head final_queue;
1437         struct list_head *l, *n;
1438         struct dasd_ccw_req *cqr;
1439
1440         atomic_set (&device->tasklet_scheduled, 0);
1441         INIT_LIST_HEAD(&final_queue);
1442         spin_lock_irq(get_ccwdev_lock(device->cdev));
1443         /* Check expire time of first request on the ccw queue. */
1444         __dasd_check_expire(device);
1445         /* Finish off requests on ccw queue */
1446         __dasd_process_ccw_queue(device, &final_queue);
1447         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1448         /* Now call the callback function of requests with final status */
1449         list_for_each_safe(l, n, &final_queue) {
1450                 cqr = list_entry(l, struct dasd_ccw_req, list);
1451                 list_del_init(&cqr->list);
1452                 if (cqr->callback != NULL)
1453                         (cqr->callback)(cqr, cqr->callback_data);
1454         }
1455         spin_lock_irq(&device->request_queue_lock);
1456         spin_lock(get_ccwdev_lock(device->cdev));
1457         /* Get new request from the block device request queue */
1458         __dasd_process_blk_queue(device);
1459         /* Now check if the head of the ccw queue needs to be started. */
1460         __dasd_start_head(device);
1461         spin_unlock(get_ccwdev_lock(device->cdev));
1462         spin_unlock_irq(&device->request_queue_lock);
1463         dasd_put_device(device);
1464 }
1465
1466 /*
1467  * Schedules a call to dasd_tasklet over the device tasklet.
1468  */
1469 void
1470 dasd_schedule_bh(struct dasd_device * device)
1471 {
1472         /* Protect against rescheduling. */
1473         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
1474                 return;
1475         dasd_get_device(device);
1476         tasklet_hi_schedule(&device->tasklet);
1477 }
1478
1479 /*
1480  * Queue a request to the head of the ccw_queue. Start the I/O if
1481  * possible.
1482  */
1483 void
1484 dasd_add_request_head(struct dasd_ccw_req *req)
1485 {
1486         struct dasd_device *device;
1487         unsigned long flags;
1488
1489         device = req->device;
1490         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1491         req->status = DASD_CQR_QUEUED;
1492         req->device = device;
1493         list_add(&req->list, &device->ccw_queue);
1494         /* let the bh start the request to keep them in order */
1495         dasd_schedule_bh(device);
1496         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1497 }
1498
1499 /*
1500  * Queue a request to the tail of the ccw_queue. Start the I/O if
1501  * possible.
1502  */
1503 void
1504 dasd_add_request_tail(struct dasd_ccw_req *req)
1505 {
1506         struct dasd_device *device;
1507         unsigned long flags;
1508
1509         device = req->device;
1510         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1511         req->status = DASD_CQR_QUEUED;
1512         req->device = device;
1513         list_add_tail(&req->list, &device->ccw_queue);
1514         /* let the bh start the request to keep them in order */
1515         dasd_schedule_bh(device);
1516         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1517 }
1518
1519 /*
1520  * Wakeup callback.
1521  */
1522 static void
1523 dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
1524 {
1525         wake_up((wait_queue_head_t *) data);
1526 }
1527
1528 static inline int
1529 _wait_for_wakeup(struct dasd_ccw_req *cqr)
1530 {
1531         struct dasd_device *device;
1532         int rc;
1533
1534         device = cqr->device;
1535         spin_lock_irq(get_ccwdev_lock(device->cdev));
1536         rc = ((cqr->status == DASD_CQR_DONE ||
1537                cqr->status == DASD_CQR_FAILED) &&
1538               list_empty(&cqr->list));
1539         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1540         return rc;
1541 }
1542
1543 /*
1544  * Attempts to start a special ccw queue and waits for its completion.
1545  */
1546 int
1547 dasd_sleep_on(struct dasd_ccw_req * cqr)
1548 {
1549         wait_queue_head_t wait_q;
1550         struct dasd_device *device;
1551         int rc;
1552
1553         device = cqr->device;
1554         spin_lock_irq(get_ccwdev_lock(device->cdev));
1555
1556         init_waitqueue_head (&wait_q);
1557         cqr->callback = dasd_wakeup_cb;
1558         cqr->callback_data = (void *) &wait_q;
1559         cqr->status = DASD_CQR_QUEUED;
1560         list_add_tail(&cqr->list, &device->ccw_queue);
1561
1562         /* let the bh start the request to keep them in order */
1563         dasd_schedule_bh(device);
1564
1565         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1566
1567         wait_event(wait_q, _wait_for_wakeup(cqr));
1568
1569         /* Request status is either done or failed. */
1570         rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1571         return rc;
1572 }
1573
1574 /*
1575  * Attempts to start a special ccw queue and wait interruptible
1576  * for its completion.
1577  */
1578 int
1579 dasd_sleep_on_interruptible(struct dasd_ccw_req * cqr)
1580 {
1581         wait_queue_head_t wait_q;
1582         struct dasd_device *device;
1583         int rc, finished;
1584
1585         device = cqr->device;
1586         spin_lock_irq(get_ccwdev_lock(device->cdev));
1587
1588         init_waitqueue_head (&wait_q);
1589         cqr->callback = dasd_wakeup_cb;
1590         cqr->callback_data = (void *) &wait_q;
1591         cqr->status = DASD_CQR_QUEUED;
1592         list_add_tail(&cqr->list, &device->ccw_queue);
1593
1594         /* let the bh start the request to keep them in order */
1595         dasd_schedule_bh(device);
1596         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1597
1598         finished = 0;
1599         while (!finished) {
1600                 rc = wait_event_interruptible(wait_q, _wait_for_wakeup(cqr));
1601                 if (rc != -ERESTARTSYS) {
1602                         /* Request is final (done or failed) */
1603                         rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO;
1604                         break;
1605                 }
1606                 spin_lock_irq(get_ccwdev_lock(device->cdev));
1607                 switch (cqr->status) {
1608                 case DASD_CQR_IN_IO:
1609                         /* terminate runnig cqr */
1610                         if (device->discipline->term_IO) {
1611                                 cqr->retries = -1;
1612                                 device->discipline->term_IO(cqr);
1613                                 /* wait (non-interruptible) for final status
1614                                  * because signal ist still pending */
1615                                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1616                                 wait_event(wait_q, _wait_for_wakeup(cqr));
1617                                 spin_lock_irq(get_ccwdev_lock(device->cdev));
1618                                 rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO;
1619                                 finished = 1;
1620                         }
1621                         break;
1622                 case DASD_CQR_QUEUED:
1623                         /* request  */
1624                         list_del_init(&cqr->list);
1625                         rc = -EIO;
1626                         finished = 1;
1627                         break;
1628                 default:
1629                         /* cqr with 'non-interruptable' status - just wait */
1630                         break;
1631                 }
1632                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1633         }
1634         return rc;
1635 }
1636
1637 /*
1638  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
1639  * for eckd devices) the currently running request has to be terminated
1640  * and be put back to status queued, before the special request is added
1641  * to the head of the queue. Then the special request is waited on normally.
1642  */
1643 static inline int
1644 _dasd_term_running_cqr(struct dasd_device *device)
1645 {
1646         struct dasd_ccw_req *cqr;
1647
1648         if (list_empty(&device->ccw_queue))
1649                 return 0;
1650         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1651         return device->discipline->term_IO(cqr);
1652 }
1653
1654 int
1655 dasd_sleep_on_immediatly(struct dasd_ccw_req * cqr)
1656 {
1657         wait_queue_head_t wait_q;
1658         struct dasd_device *device;
1659         int rc;
1660
1661         device = cqr->device;
1662         spin_lock_irq(get_ccwdev_lock(device->cdev));
1663         rc = _dasd_term_running_cqr(device);
1664         if (rc) {
1665                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1666                 return rc;
1667         }
1668
1669         init_waitqueue_head (&wait_q);
1670         cqr->callback = dasd_wakeup_cb;
1671         cqr->callback_data = (void *) &wait_q;
1672         cqr->status = DASD_CQR_QUEUED;
1673         list_add(&cqr->list, &device->ccw_queue);
1674
1675         /* let the bh start the request to keep them in order */
1676         dasd_schedule_bh(device);
1677
1678         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1679
1680         wait_event(wait_q, _wait_for_wakeup(cqr));
1681
1682         /* Request status is either done or failed. */
1683         rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1684         return rc;
1685 }
1686
1687 /*
1688  * Cancels a request that was started with dasd_sleep_on_req.
1689  * This is useful to timeout requests. The request will be
1690  * terminated if it is currently in i/o.
1691  * Returns 1 if the request has been terminated.
1692  */
1693 int
1694 dasd_cancel_req(struct dasd_ccw_req *cqr)
1695 {
1696         struct dasd_device *device = cqr->device;
1697         unsigned long flags;
1698         int rc;
1699
1700         rc = 0;
1701         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1702         switch (cqr->status) {
1703         case DASD_CQR_QUEUED:
1704                 /* request was not started - just set to failed */
1705                 cqr->status = DASD_CQR_FAILED;
1706                 break;
1707         case DASD_CQR_IN_IO:
1708                 /* request in IO - terminate IO and release again */
1709                 if (device->discipline->term_IO(cqr) != 0)
1710                         /* what to do if unable to terminate ??????
1711                            e.g. not _IN_IO */
1712                         cqr->status = DASD_CQR_FAILED;
1713                 cqr->stopclk = get_clock();
1714                 rc = 1;
1715                 break;
1716         case DASD_CQR_DONE:
1717         case DASD_CQR_FAILED:
1718                 /* already finished - do nothing */
1719                 break;
1720         default:
1721                 DEV_MESSAGE(KERN_ALERT, device,
1722                             "invalid status %02x in request",
1723                             cqr->status);
1724                 BUG();
1725
1726         }
1727         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1728         dasd_schedule_bh(device);
1729         return rc;
1730 }
1731
1732 /*
1733  * SECTION: Block device operations (request queue, partitions, open, release).
1734  */
1735
1736 /*
1737  * Dasd request queue function. Called from ll_rw_blk.c
1738  */
1739 static void
1740 do_dasd_request(request_queue_t * queue)
1741 {
1742         struct dasd_device *device;
1743
1744         device = (struct dasd_device *) queue->queuedata;
1745         spin_lock(get_ccwdev_lock(device->cdev));
1746         /* Get new request from the block device request queue */
1747         __dasd_process_blk_queue(device);
1748         /* Now check if the head of the ccw queue needs to be started. */
1749         __dasd_start_head(device);
1750         spin_unlock(get_ccwdev_lock(device->cdev));
1751 }
1752
1753 /*
1754  * Allocate and initialize request queue and default I/O scheduler.
1755  */
1756 static int
1757 dasd_alloc_queue(struct dasd_device * device)
1758 {
1759         int rc;
1760
1761         device->request_queue = blk_init_queue(do_dasd_request,
1762                                                &device->request_queue_lock);
1763         if (device->request_queue == NULL)
1764                 return -ENOMEM;
1765
1766         device->request_queue->queuedata = device;
1767
1768         elevator_exit(device->request_queue->elevator);
1769         rc = elevator_init(device->request_queue, "deadline");
1770         if (rc) {
1771                 blk_cleanup_queue(device->request_queue);
1772                 return rc;
1773         }
1774         return 0;
1775 }
1776
1777 /*
1778  * Allocate and initialize request queue.
1779  */
1780 static void
1781 dasd_setup_queue(struct dasd_device * device)
1782 {
1783         int max;
1784
1785         blk_queue_hardsect_size(device->request_queue, device->bp_block);
1786         max = device->discipline->max_blocks << device->s2b_shift;
1787         blk_queue_max_sectors(device->request_queue, max);
1788         blk_queue_max_phys_segments(device->request_queue, -1L);
1789         blk_queue_max_hw_segments(device->request_queue, -1L);
1790         blk_queue_max_segment_size(device->request_queue, -1L);
1791         blk_queue_segment_boundary(device->request_queue, -1L);
1792         blk_queue_ordered(device->request_queue, QUEUE_ORDERED_TAG, NULL);
1793 }
1794
1795 /*
1796  * Deactivate and free request queue.
1797  */
1798 static void
1799 dasd_free_queue(struct dasd_device * device)
1800 {
1801         if (device->request_queue) {
1802                 blk_cleanup_queue(device->request_queue);
1803                 device->request_queue = NULL;
1804         }
1805 }
1806
1807 /*
1808  * Flush request on the request queue.
1809  */
1810 static void
1811 dasd_flush_request_queue(struct dasd_device * device)
1812 {
1813         struct request *req;
1814
1815         if (!device->request_queue)
1816                 return;
1817
1818         spin_lock_irq(&device->request_queue_lock);
1819         while ((req = elv_next_request(device->request_queue))) {
1820                 blkdev_dequeue_request(req);
1821                 dasd_end_request(req, 0);
1822         }
1823         spin_unlock_irq(&device->request_queue_lock);
1824 }
1825
1826 static int
1827 dasd_open(struct inode *inp, struct file *filp)
1828 {
1829         struct gendisk *disk = inp->i_bdev->bd_disk;
1830         struct dasd_device *device = disk->private_data;
1831         int rc;
1832
1833         atomic_inc(&device->open_count);
1834         if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1835                 rc = -ENODEV;
1836                 goto unlock;
1837         }
1838
1839         if (!try_module_get(device->discipline->owner)) {
1840                 rc = -EINVAL;
1841                 goto unlock;
1842         }
1843
1844         if (dasd_probeonly) {
1845                 DEV_MESSAGE(KERN_INFO, device, "%s",
1846                             "No access to device due to probeonly mode");
1847                 rc = -EPERM;
1848                 goto out;
1849         }
1850
1851         if (device->state <= DASD_STATE_BASIC) {
1852                 DBF_DEV_EVENT(DBF_ERR, device, " %s",
1853                               " Cannot open unrecognized device");
1854                 rc = -ENODEV;
1855                 goto out;
1856         }
1857
1858         return 0;
1859
1860 out:
1861         module_put(device->discipline->owner);
1862 unlock:
1863         atomic_dec(&device->open_count);
1864         return rc;
1865 }
1866
1867 static int
1868 dasd_release(struct inode *inp, struct file *filp)
1869 {
1870         struct gendisk *disk = inp->i_bdev->bd_disk;
1871         struct dasd_device *device = disk->private_data;
1872
1873         atomic_dec(&device->open_count);
1874         module_put(device->discipline->owner);
1875         return 0;
1876 }
1877
1878 /*
1879  * Return disk geometry.
1880  */
1881 static int
1882 dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
1883 {
1884         struct dasd_device *device;
1885
1886         device = bdev->bd_disk->private_data;
1887         if (!device)
1888                 return -ENODEV;
1889
1890         if (!device->discipline ||
1891             !device->discipline->fill_geometry)
1892                 return -EINVAL;
1893
1894         device->discipline->fill_geometry(device, geo);
1895         geo->start = get_start_sect(bdev) >> device->s2b_shift;
1896         return 0;
1897 }
1898
1899 struct block_device_operations
1900 dasd_device_operations = {
1901         .owner          = THIS_MODULE,
1902         .open           = dasd_open,
1903         .release        = dasd_release,
1904         .ioctl          = dasd_ioctl,
1905         .compat_ioctl   = dasd_compat_ioctl,
1906         .getgeo         = dasd_getgeo,
1907 };
1908
1909
1910 static void
1911 dasd_exit(void)
1912 {
1913 #ifdef CONFIG_PROC_FS
1914         dasd_proc_exit();
1915 #endif
1916         dasd_eer_exit();
1917         if (dasd_page_cache != NULL) {
1918                 kmem_cache_destroy(dasd_page_cache);
1919                 dasd_page_cache = NULL;
1920         }
1921         dasd_gendisk_exit();
1922         dasd_devmap_exit();
1923         if (dasd_debug_area != NULL) {
1924                 debug_unregister(dasd_debug_area);
1925                 dasd_debug_area = NULL;
1926         }
1927 }
1928
1929 /*
1930  * SECTION: common functions for ccw_driver use
1931  */
1932
1933 /*
1934  * Initial attempt at a probe function. this can be simplified once
1935  * the other detection code is gone.
1936  */
1937 int
1938 dasd_generic_probe (struct ccw_device *cdev,
1939                     struct dasd_discipline *discipline)
1940 {
1941         int ret;
1942
1943         ret = ccw_device_set_options(cdev, CCWDEV_DO_PATHGROUP);
1944         if (ret) {
1945                 printk(KERN_WARNING
1946                        "dasd_generic_probe: could not set ccw-device options "
1947                        "for %s\n", cdev->dev.bus_id);
1948                 return ret;
1949         }
1950         ret = dasd_add_sysfs_files(cdev);
1951         if (ret) {
1952                 printk(KERN_WARNING
1953                        "dasd_generic_probe: could not add sysfs entries "
1954                        "for %s\n", cdev->dev.bus_id);
1955                 return ret;
1956         }
1957         cdev->handler = &dasd_int_handler;
1958
1959         /*
1960          * Automatically online either all dasd devices (dasd_autodetect)
1961          * or all devices specified with dasd= parameters during
1962          * initial probe.
1963          */
1964         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
1965             (dasd_autodetect && dasd_busid_known(cdev->dev.bus_id) != 0))
1966                 ret = ccw_device_set_online(cdev);
1967         if (ret)
1968                 printk(KERN_WARNING
1969                        "dasd_generic_probe: could not initially online "
1970                        "ccw-device %s\n", cdev->dev.bus_id);
1971         return ret;
1972 }
1973
1974 /*
1975  * This will one day be called from a global not_oper handler.
1976  * It is also used by driver_unregister during module unload.
1977  */
1978 void
1979 dasd_generic_remove (struct ccw_device *cdev)
1980 {
1981         struct dasd_device *device;
1982
1983         cdev->handler = NULL;
1984
1985         dasd_remove_sysfs_files(cdev);
1986         device = dasd_device_from_cdev(cdev);
1987         if (IS_ERR(device))
1988                 return;
1989         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1990                 /* Already doing offline processing */
1991                 dasd_put_device(device);
1992                 return;
1993         }
1994         /*
1995          * This device is removed unconditionally. Set offline
1996          * flag to prevent dasd_open from opening it while it is
1997          * no quite down yet.
1998          */
1999         dasd_set_target_state(device, DASD_STATE_NEW);
2000         /* dasd_delete_device destroys the device reference. */
2001         dasd_delete_device(device);
2002 }
2003
2004 /*
2005  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
2006  * the device is detected for the first time and is supposed to be used
2007  * or the user has started activation through sysfs.
2008  */
2009 int
2010 dasd_generic_set_online (struct ccw_device *cdev,
2011                          struct dasd_discipline *base_discipline)
2012
2013 {
2014         struct dasd_discipline *discipline;
2015         struct dasd_device *device;
2016         int rc;
2017
2018         /* first online clears initial online feature flag */
2019         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
2020         device = dasd_create_device(cdev);
2021         if (IS_ERR(device))
2022                 return PTR_ERR(device);
2023
2024         discipline = base_discipline;
2025         if (device->features & DASD_FEATURE_USEDIAG) {
2026                 if (!dasd_diag_discipline_pointer) {
2027                         printk (KERN_WARNING
2028                                 "dasd_generic couldn't online device %s "
2029                                 "- discipline DIAG not available\n",
2030                                 cdev->dev.bus_id);
2031                         dasd_delete_device(device);
2032                         return -ENODEV;
2033                 }
2034                 discipline = dasd_diag_discipline_pointer;
2035         }
2036         if (!try_module_get(base_discipline->owner)) {
2037                 dasd_delete_device(device);
2038                 return -EINVAL;
2039         }
2040         if (!try_module_get(discipline->owner)) {
2041                 module_put(base_discipline->owner);
2042                 dasd_delete_device(device);
2043                 return -EINVAL;
2044         }
2045         device->base_discipline = base_discipline;
2046         device->discipline = discipline;
2047
2048         rc = discipline->check_device(device);
2049         if (rc) {
2050                 printk (KERN_WARNING
2051                         "dasd_generic couldn't online device %s "
2052                         "with discipline %s rc=%i\n",
2053                         cdev->dev.bus_id, discipline->name, rc);
2054                 module_put(discipline->owner);
2055                 module_put(base_discipline->owner);
2056                 dasd_delete_device(device);
2057                 return rc;
2058         }
2059
2060         dasd_set_target_state(device, DASD_STATE_ONLINE);
2061         if (device->state <= DASD_STATE_KNOWN) {
2062                 printk (KERN_WARNING
2063                         "dasd_generic discipline not found for %s\n",
2064                         cdev->dev.bus_id);
2065                 rc = -ENODEV;
2066                 dasd_set_target_state(device, DASD_STATE_NEW);
2067                 dasd_delete_device(device);
2068         } else
2069                 pr_debug("dasd_generic device %s found\n",
2070                                 cdev->dev.bus_id);
2071
2072         /* FIXME: we have to wait for the root device but we don't want
2073          * to wait for each single device but for all at once. */
2074         wait_event(dasd_init_waitq, _wait_for_device(device));
2075
2076         dasd_put_device(device);
2077
2078         return rc;
2079 }
2080
2081 int
2082 dasd_generic_set_offline (struct ccw_device *cdev)
2083 {
2084         struct dasd_device *device;
2085         int max_count, open_count;
2086
2087         device = dasd_device_from_cdev(cdev);
2088         if (IS_ERR(device))
2089                 return PTR_ERR(device);
2090         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
2091                 /* Already doing offline processing */
2092                 dasd_put_device(device);
2093                 return 0;
2094         }
2095         /*
2096          * We must make sure that this device is currently not in use.
2097          * The open_count is increased for every opener, that includes
2098          * the blkdev_get in dasd_scan_partitions. We are only interested
2099          * in the other openers.
2100          */
2101         max_count = device->bdev ? 0 : -1;
2102         open_count = (int) atomic_read(&device->open_count);
2103         if (open_count > max_count) {
2104                 if (open_count > 0)
2105                         printk (KERN_WARNING "Can't offline dasd device with "
2106                                 "open count = %i.\n",
2107                                 open_count);
2108                 else
2109                         printk (KERN_WARNING "%s",
2110                                 "Can't offline dasd device due to internal "
2111                                 "use\n");
2112                 clear_bit(DASD_FLAG_OFFLINE, &device->flags);
2113                 dasd_put_device(device);
2114                 return -EBUSY;
2115         }
2116         dasd_set_target_state(device, DASD_STATE_NEW);
2117         /* dasd_delete_device destroys the device reference. */
2118         dasd_delete_device(device);
2119
2120         return 0;
2121 }
2122
2123 int
2124 dasd_generic_notify(struct ccw_device *cdev, int event)
2125 {
2126         struct dasd_device *device;
2127         struct dasd_ccw_req *cqr;
2128         unsigned long flags;
2129         int ret;
2130
2131         device = dasd_device_from_cdev(cdev);
2132         if (IS_ERR(device))
2133                 return 0;
2134         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
2135         ret = 0;
2136         switch (event) {
2137         case CIO_GONE:
2138         case CIO_NO_PATH:
2139                 /* First of all call extended error reporting. */
2140                 dasd_eer_write(device, NULL, DASD_EER_NOPATH);
2141
2142                 if (device->state < DASD_STATE_BASIC)
2143                         break;
2144                 /* Device is active. We want to keep it. */
2145                 if (test_bit(DASD_FLAG_DSC_ERROR, &device->flags)) {
2146                         list_for_each_entry(cqr, &device->ccw_queue, list)
2147                                 if (cqr->status == DASD_CQR_IN_IO)
2148                                         cqr->status = DASD_CQR_FAILED;
2149                         device->stopped |= DASD_STOPPED_DC_EIO;
2150                 } else {
2151                         list_for_each_entry(cqr, &device->ccw_queue, list)
2152                                 if (cqr->status == DASD_CQR_IN_IO) {
2153                                         cqr->status = DASD_CQR_QUEUED;
2154                                         cqr->retries++;
2155                                 }
2156                         device->stopped |= DASD_STOPPED_DC_WAIT;
2157                         dasd_set_timer(device, 0);
2158                 }
2159                 dasd_schedule_bh(device);
2160                 ret = 1;
2161                 break;
2162         case CIO_OPER:
2163                 /* FIXME: add a sanity check. */
2164                 device->stopped &= ~(DASD_STOPPED_DC_WAIT|DASD_STOPPED_DC_EIO);
2165                 dasd_schedule_bh(device);
2166                 ret = 1;
2167                 break;
2168         }
2169         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
2170         dasd_put_device(device);
2171         return ret;
2172 }
2173
2174
2175 static int __init
2176 dasd_init(void)
2177 {
2178         int rc;
2179
2180         init_waitqueue_head(&dasd_init_waitq);
2181         init_waitqueue_head(&dasd_flush_wq);
2182
2183         /* register 'common' DASD debug area, used for all DBF_XXX calls */
2184         dasd_debug_area = debug_register("dasd", 1, 2, 8 * sizeof (long));
2185         if (dasd_debug_area == NULL) {
2186                 rc = -ENOMEM;
2187                 goto failed;
2188         }
2189         debug_register_view(dasd_debug_area, &debug_sprintf_view);
2190         debug_set_level(dasd_debug_area, DBF_WARNING);
2191
2192         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
2193
2194         dasd_diag_discipline_pointer = NULL;
2195
2196         rc = dasd_devmap_init();
2197         if (rc)
2198                 goto failed;
2199         rc = dasd_gendisk_init();
2200         if (rc)
2201                 goto failed;
2202         rc = dasd_parse();
2203         if (rc)
2204                 goto failed;
2205         rc = dasd_eer_init();
2206         if (rc)
2207                 goto failed;
2208 #ifdef CONFIG_PROC_FS
2209         rc = dasd_proc_init();
2210         if (rc)
2211                 goto failed;
2212 #endif
2213
2214         return 0;
2215 failed:
2216         MESSAGE(KERN_INFO, "%s", "initialization not performed due to errors");
2217         dasd_exit();
2218         return rc;
2219 }
2220
2221 module_init(dasd_init);
2222 module_exit(dasd_exit);
2223
2224 EXPORT_SYMBOL(dasd_debug_area);
2225 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
2226
2227 EXPORT_SYMBOL(dasd_add_request_head);
2228 EXPORT_SYMBOL(dasd_add_request_tail);
2229 EXPORT_SYMBOL(dasd_cancel_req);
2230 EXPORT_SYMBOL(dasd_clear_timer);
2231 EXPORT_SYMBOL(dasd_enable_device);
2232 EXPORT_SYMBOL(dasd_int_handler);
2233 EXPORT_SYMBOL(dasd_kfree_request);
2234 EXPORT_SYMBOL(dasd_kick_device);
2235 EXPORT_SYMBOL(dasd_kmalloc_request);
2236 EXPORT_SYMBOL(dasd_schedule_bh);
2237 EXPORT_SYMBOL(dasd_set_target_state);
2238 EXPORT_SYMBOL(dasd_set_timer);
2239 EXPORT_SYMBOL(dasd_sfree_request);
2240 EXPORT_SYMBOL(dasd_sleep_on);
2241 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2242 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2243 EXPORT_SYMBOL(dasd_smalloc_request);
2244 EXPORT_SYMBOL(dasd_start_IO);
2245 EXPORT_SYMBOL(dasd_term_IO);
2246
2247 EXPORT_SYMBOL_GPL(dasd_generic_probe);
2248 EXPORT_SYMBOL_GPL(dasd_generic_remove);
2249 EXPORT_SYMBOL_GPL(dasd_generic_notify);
2250 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
2251 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
2252