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/config.h>
  13 #include <linux/kmod.h>
  14 #include <linux/init.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/ctype.h>
  17 #include <linux/major.h>
  18 #include <linux/slab.h>
  19 #include <linux/buffer_head.h>
  20 #include <linux/hdreg.h>
  21
  22 #include <asm/ccwdev.h>
  23 #include <asm/ebcdic.h>
  24 #include <asm/idals.h>
  25 #include <asm/todclk.h>
  26
  27 /* This is ugly... */
  28 #define PRINTK_HEADER "dasd:"
  29
  30 #include "dasd_int.h"
  31 /*
  32  * SECTION: Constant definitions to be used within this file
  33  */
  34 #define DASD_CHANQ_MAX_SIZE 4
  35
  36 /*
  37  * SECTION: exported variables of dasd.c
  38  */
  39 debug_info_t *dasd_debug_area;
  40 struct dasd_discipline *dasd_diag_discipline_pointer;
  41
  42 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
  43 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
  44                    " Copyright 2000 IBM Corporation");
  45 MODULE_SUPPORTED_DEVICE("dasd");
  46 MODULE_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 void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
  56 static void dasd_flush_ccw_queue(struct dasd_device *, int);
  57 static void dasd_tasklet(struct dasd_device *);
  58 static void do_kick_device(void *data);
  59
  60 /*
  61  * SECTION: Operations on the device structure.
  62  */
  63 static wait_queue_head_t dasd_init_waitq;
  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, 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 inline 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 inline void
 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 }
 168
 169 /*
 170  * Request the irq line for the device.
 171  */
 172 static inline int
 173 dasd_state_known_to_basic(struct dasd_device * device)
 174 {
 175         int rc;
 176
 177         /* Allocate and register gendisk structure. */
 178         rc = dasd_gendisk_alloc(device);
 179         if (rc)
 180                 return rc;
 181
 182         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 183         device->debug_area = debug_register(device->cdev->dev.bus_id, 1, 2,
 184                                             8 * sizeof (long));
 185         debug_register_view(device->debug_area, &debug_sprintf_view);
 186         debug_set_level(device->debug_area, DBF_EMERG);
 187         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 188
 189         device->state = DASD_STATE_BASIC;
 190         return 0;
 191 }
 192
 193 /*
 194  * Release the irq line for the device. Terminate any running i/o.
 195  */
 196 static inline void
 197 dasd_state_basic_to_known(struct dasd_device * device)
 198 {
 199         dasd_gendisk_free(device);
 200         dasd_flush_ccw_queue(device, 1);
 201         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
 202         if (device->debug_area != NULL) {
 203                 debug_unregister(device->debug_area);
 204                 device->debug_area = NULL;
 205         }
 206         device->state = DASD_STATE_KNOWN;
 207 }
 208
 209 /*
 210  * Do the initial analysis. The do_analysis function may return
 211  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 212  * until the discipline decides to continue the startup sequence
 213  * by calling the function dasd_change_state. The eckd disciplines
 214  * uses this to start a ccw that detects the format. The completion
 215  * interrupt for this detection ccw uses the kernel event daemon to
 216  * trigger the call to dasd_change_state. All this is done in the
 217  * discipline code, see dasd_eckd.c.
 218  * After the analysis ccw is done (do_analysis returned 0) the block
 219  * device is setup.
 220  * In case the analysis returns an error, the device setup is stopped
 221  * (a fake disk was already added to allow formatting).
 222  */
 223 static inline int
 224 dasd_state_basic_to_ready(struct dasd_device * device)
 225 {
 226         int rc;
 227
 228         rc = 0;
 229         if (device->discipline->do_analysis != NULL)
 230                 rc = device->discipline->do_analysis(device);
 231         if (rc) {
 232                 if (rc != -EAGAIN)
 233                         device->state = DASD_STATE_UNFMT;
 234                 return rc;
 235         }
 236         /* make disk known with correct capacity */
 237         dasd_setup_queue(device);
 238         set_capacity(device->gdp, device->blocks << device->s2b_shift);
 239         device->state = DASD_STATE_READY;
 240         rc = dasd_scan_partitions(device);
 241         if (rc)
 242                 device->state = DASD_STATE_BASIC;
 243         return rc;
 244 }
 245
 246 /*
 247  * Remove device from block device layer. Destroy dirty buffers.
 248  * Forget format information. Check if the target level is basic
 249  * and if it is create fake disk for formatting.
 250  */
 251 static inline void
 252 dasd_state_ready_to_basic(struct dasd_device * device)
 253 {
 254         dasd_flush_ccw_queue(device, 0);
 255         dasd_destroy_partitions(device);
 256         dasd_flush_request_queue(device);
 257         device->blocks = 0;
 258         device->bp_block = 0;
 259         device->s2b_shift = 0;
 260         device->state = DASD_STATE_BASIC;
 261 }
 262
 263 /*
 264  * Back to basic.
 265  */
 266 static inline void
 267 dasd_state_unfmt_to_basic(struct dasd_device * device)
 268 {
 269         device->state = DASD_STATE_BASIC;
 270 }
 271
 272 /*
 273  * Make the device online and schedule the bottom half to start
 274  * the requeueing of requests from the linux request queue to the
 275  * ccw queue.
 276  */
 277 static inline int
 278 dasd_state_ready_to_online(struct dasd_device * device)
 279 {
 280         device->state = DASD_STATE_ONLINE;
 281         dasd_schedule_bh(device);
 282         return 0;
 283 }
 284
 285 /*
 286  * Stop the requeueing of requests again.
 287  */
 288 static inline void
 289 dasd_state_online_to_ready(struct dasd_device * device)
 290 {
 291         device->state = DASD_STATE_READY;
 292 }
 293
 294 /*
 295  * Device startup state changes.
 296  */
 297 static inline int
 298 dasd_increase_state(struct dasd_device *device)
 299 {
 300         int rc;
 301
 302         rc = 0;
 303         if (device->state == DASD_STATE_NEW &&
 304             device->target >= DASD_STATE_KNOWN)
 305                 rc = dasd_state_new_to_known(device);
 306
 307         if (!rc &&
 308             device->state == DASD_STATE_KNOWN &&
 309             device->target >= DASD_STATE_BASIC)
 310                 rc = dasd_state_known_to_basic(device);
 311
 312         if (!rc &&
 313             device->state == DASD_STATE_BASIC &&
 314             device->target >= DASD_STATE_READY)
 315                 rc = dasd_state_basic_to_ready(device);
 316
 317         if (!rc &&
 318             device->state == DASD_STATE_READY &&
 319             device->target >= DASD_STATE_ONLINE)
 320                 rc = dasd_state_ready_to_online(device);
 321
 322         return rc;
 323 }
 324
 325 /*
 326  * Device shutdown state changes.
 327  */
 328 static inline int
 329 dasd_decrease_state(struct dasd_device *device)
 330 {
 331         if (device->state == DASD_STATE_ONLINE &&
 332             device->target <= DASD_STATE_READY)
 333                 dasd_state_online_to_ready(device);
 334
 335         if (device->state == DASD_STATE_READY &&
 336             device->target <= DASD_STATE_BASIC)
 337                 dasd_state_ready_to_basic(device);
 338
 339         if (device->state == DASD_STATE_UNFMT &&
 340             device->target <= DASD_STATE_BASIC)
 341                 dasd_state_unfmt_to_basic(device);
 342
 343         if (device->state == DASD_STATE_BASIC &&
 344             device->target <= DASD_STATE_KNOWN)
 345                 dasd_state_basic_to_known(device);
 346
 347         if (device->state == DASD_STATE_KNOWN &&
 348             device->target <= DASD_STATE_NEW)
 349                 dasd_state_known_to_new(device);
 350
 351         return 0;
 352 }
 353
 354 /*
 355  * This is the main startup/shutdown routine.
 356  */
 357 static void
 358 dasd_change_state(struct dasd_device *device)
 359 {
 360         int rc;
 361
 362         if (device->state == device->target)
 363                 /* Already where we want to go today... */
 364                 return;
 365         if (device->state < device->target)
 366                 rc = dasd_increase_state(device);
 367         else
 368                 rc = dasd_decrease_state(device);
 369         if (rc && rc != -EAGAIN)
 370                 device->target = device->state;
 371
 372         if (device->state == device->target)
 373                 wake_up(&dasd_init_waitq);
 374 }
 375
 376 /*
 377  * Kick starter for devices that did not complete the startup/shutdown
 378  * procedure or were sleeping because of a pending state.
 379  * dasd_kick_device will schedule a call do do_kick_device to the kernel
 380  * event daemon.
 381  */
 382 static void
 383 do_kick_device(void *data)
 384 {
 385         struct dasd_device *device;
 386
 387         device = (struct dasd_device *) data;
 388         dasd_change_state(device);
 389         dasd_schedule_bh(device);
 390         dasd_put_device(device);
 391 }
 392
 393 void
 394 dasd_kick_device(struct dasd_device *device)
 395 {
 396         dasd_get_device(device);
 397         /* queue call to dasd_kick_device to the kernel event daemon. */
 398         schedule_work(&device->kick_work);
 399 }
 400
 401 /*
 402  * Set the target state for a device and starts the state change.
 403  */
 404 void
 405 dasd_set_target_state(struct dasd_device *device, int target)
 406 {
 407         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 408         if (dasd_probeonly && target > DASD_STATE_READY)
 409                 target = DASD_STATE_READY;
 410         if (device->target != target) {
 411                 if (device->state == target)
 412                         wake_up(&dasd_init_waitq);
 413                 device->target = target;
 414         }
 415         if (device->state != device->target)
 416                 dasd_change_state(device);
 417 }
 418
 419 /*
 420  * Enable devices with device numbers in [from..to].
 421  */
 422 static inline int
 423 _wait_for_device(struct dasd_device *device)
 424 {
 425         return (device->state == device->target);
 426 }
 427
 428 void
 429 dasd_enable_device(struct dasd_device *device)
 430 {
 431         dasd_set_target_state(device, DASD_STATE_ONLINE);
 432         if (device->state <= DASD_STATE_KNOWN)
 433                 /* No discipline for device found. */
 434                 dasd_set_target_state(device, DASD_STATE_NEW);
 435         /* Now wait for the devices to come up. */
 436         wait_event(dasd_init_waitq, _wait_for_device(device));
 437 }
 438
 439 /*
 440  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 441  */
 442 #ifdef CONFIG_DASD_PROFILE
 443
 444 struct dasd_profile_info_t dasd_global_profile;
 445 unsigned int dasd_profile_level = DASD_PROFILE_OFF;
 446
 447 /*
 448  * Increments counter in global and local profiling structures.
 449  */
 450 #define dasd_profile_counter(value, counter, device) \
 451 { \
 452         int index; \
 453         for (index = 0; index < 31 && value >> (2+index); index++); \
 454         dasd_global_profile.counter[index]++; \
 455         device->profile.counter[index]++; \
 456 }
 457
 458 /*
 459  * Add profiling information for cqr before execution.
 460  */
 461 static inline void
 462 dasd_profile_start(struct dasd_device *device, struct dasd_ccw_req * cqr,
 463                    struct request *req)
 464 {
 465         struct list_head *l;
 466         unsigned int counter;
 467
 468         if (dasd_profile_level != DASD_PROFILE_ON)
 469                 return;
 470
 471         /* count the length of the chanq for statistics */
 472         counter = 0;
 473         list_for_each(l, &device->ccw_queue)
 474                 if (++counter >= 31)
 475                         break;
 476         dasd_global_profile.dasd_io_nr_req[counter]++;
 477         device->profile.dasd_io_nr_req[counter]++;
 478 }
 479
 480 /*
 481  * Add profiling information for cqr after execution.
 482  */
 483 static inline void
 484 dasd_profile_end(struct dasd_device *device, struct dasd_ccw_req * cqr,
 485                  struct request *req)
 486 {
 487         long strtime, irqtime, endtime, tottime;        /* in microseconds */
 488         long tottimeps, sectors;
 489
 490         if (dasd_profile_level != DASD_PROFILE_ON)
 491                 return;
 492
 493         sectors = req->nr_sectors;
 494         if (!cqr->buildclk || !cqr->startclk ||
 495             !cqr->stopclk || !cqr->endclk ||
 496             !sectors)
 497                 return;
 498
 499         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 500         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 501         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 502         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 503         tottimeps = tottime / sectors;
 504
 505         if (!dasd_global_profile.dasd_io_reqs)
 506                 memset(&dasd_global_profile, 0,
 507                        sizeof (struct dasd_profile_info_t));
 508         dasd_global_profile.dasd_io_reqs++;
 509         dasd_global_profile.dasd_io_sects += sectors;
 510
 511         if (!device->profile.dasd_io_reqs)
 512                 memset(&device->profile, 0,
 513                        sizeof (struct dasd_profile_info_t));
 514         device->profile.dasd_io_reqs++;
 515         device->profile.dasd_io_sects += sectors;
 516
 517         dasd_profile_counter(sectors, dasd_io_secs, device);
 518         dasd_profile_counter(tottime, dasd_io_times, device);
 519         dasd_profile_counter(tottimeps, dasd_io_timps, device);
 520         dasd_profile_counter(strtime, dasd_io_time1, device);
 521         dasd_profile_counter(irqtime, dasd_io_time2, device);
 522         dasd_profile_counter(irqtime / sectors, dasd_io_time2ps, device);
 523         dasd_profile_counter(endtime, dasd_io_time3, device);
 524 }
 525 #else
 526 #define dasd_profile_start(device, cqr, req) do {} while (0)
 527 #define dasd_profile_end(device, cqr, req) do {} while (0)
 528 #endif                          /* CONFIG_DASD_PROFILE */
 529
 530 /*
 531  * Allocate memory for a channel program with 'cplength' channel
 532  * command words and 'datasize' additional space. There are two
 533  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
 534  * memory and 2) dasd_smalloc_request uses the static ccw memory
 535  * that gets allocated for each device.
 536  */
 537 struct dasd_ccw_req *
 538 dasd_kmalloc_request(char *magic, int cplength, int datasize,
 539                    struct dasd_device * device)
 540 {
 541         struct dasd_ccw_req *cqr;
 542
 543         /* Sanity checks */
 544         if ( magic == NULL || datasize > PAGE_SIZE ||
 545              (cplength*sizeof(struct ccw1)) > PAGE_SIZE)
 546                 BUG();
 547
 548         cqr = kzalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
 549         if (cqr == NULL)
 550                 return ERR_PTR(-ENOMEM);
 551         cqr->cpaddr = NULL;
 552         if (cplength > 0) {
 553                 cqr->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
 554                                       GFP_ATOMIC | GFP_DMA);
 555                 if (cqr->cpaddr == NULL) {
 556                         kfree(cqr);
 557                         return ERR_PTR(-ENOMEM);
 558                 }
 559         }
 560         cqr->data = NULL;
 561         if (datasize > 0) {
 562                 cqr->data = kzalloc(datasize, GFP_ATOMIC | GFP_DMA);
 563                 if (cqr->data == NULL) {
 564                         kfree(cqr->cpaddr);
 565                         kfree(cqr);
 566                         return ERR_PTR(-ENOMEM);
 567                 }
 568         }
 569         strncpy((char *) &cqr->magic, magic, 4);
 570         ASCEBC((char *) &cqr->magic, 4);
 571         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
 572         dasd_get_device(device);
 573         return cqr;
 574 }
 575
 576 struct dasd_ccw_req *
 577 dasd_smalloc_request(char *magic, int cplength, int datasize,
 578                    struct dasd_device * device)
 579 {
 580         unsigned long flags;
 581         struct dasd_ccw_req *cqr;
 582         char *data;
 583         int size;
 584
 585         /* Sanity checks */
 586         if ( magic == NULL || datasize > PAGE_SIZE ||
 587              (cplength*sizeof(struct ccw1)) > PAGE_SIZE)
 588                 BUG();
 589
 590         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
 591         if (cplength > 0)
 592                 size += cplength * sizeof(struct ccw1);
 593         if (datasize > 0)
 594                 size += datasize;
 595         spin_lock_irqsave(&device->mem_lock, flags);
 596         cqr = (struct dasd_ccw_req *)
 597                 dasd_alloc_chunk(&device->ccw_chunks, size);
 598         spin_unlock_irqrestore(&device->mem_lock, flags);
 599         if (cqr == NULL)
 600                 return ERR_PTR(-ENOMEM);
 601         memset(cqr, 0, sizeof(struct dasd_ccw_req));
 602         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
 603         cqr->cpaddr = NULL;
 604         if (cplength > 0) {
 605                 cqr->cpaddr = (struct ccw1 *) data;
 606                 data += cplength*sizeof(struct ccw1);
 607                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
 608         }
 609         cqr->data = NULL;
 610         if (datasize > 0) {
 611                 cqr->data = data;
 612                 memset(cqr->data, 0, datasize);
 613         }
 614         strncpy((char *) &cqr->magic, magic, 4);
 615         ASCEBC((char *) &cqr->magic, 4);
 616         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
 617         dasd_get_device(device);
 618         return cqr;
 619 }
 620
 621 /*
 622  * Free memory of a channel program. This function needs to free all the
 623  * idal lists that might have been created by dasd_set_cda and the
 624  * struct dasd_ccw_req itself.
 625  */
 626 void
 627 dasd_kfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
 628 {
 629 #ifdef CONFIG_64BIT
 630         struct ccw1 *ccw;
 631
 632         /* Clear any idals used for the request. */
 633         ccw = cqr->cpaddr;
 634         do {
 635                 clear_normalized_cda(ccw);
 636         } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
 637 #endif
 638         kfree(cqr->cpaddr);
 639         kfree(cqr->data);
 640         kfree(cqr);
 641         dasd_put_device(device);
 642 }
 643
 644 void
 645 dasd_sfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
 646 {
 647         unsigned long flags;
 648
 649         spin_lock_irqsave(&device->mem_lock, flags);
 650         dasd_free_chunk(&device->ccw_chunks, cqr);
 651         spin_unlock_irqrestore(&device->mem_lock, flags);
 652         dasd_put_device(device);
 653 }
 654
 655 /*
 656  * Check discipline magic in cqr.
 657  */
 658 static inline int
 659 dasd_check_cqr(struct dasd_ccw_req *cqr)
 660 {
 661         struct dasd_device *device;
 662
 663         if (cqr == NULL)
 664                 return -EINVAL;
 665         device = cqr->device;
 666         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
 667                 DEV_MESSAGE(KERN_WARNING, device,
 668                             " dasd_ccw_req 0x%08x magic doesn't match"
 669                             " discipline 0x%08x",
 670                             cqr->magic,
 671                             *(unsigned int *) device->discipline->name);
 672                 return -EINVAL;
 673         }
 674         return 0;
 675 }
 676
 677 /*
 678  * Terminate the current i/o and set the request to clear_pending.
 679  * Timer keeps device runnig.
 680  * ccw_device_clear can fail if the i/o subsystem
 681  * is in a bad mood.
 682  */
 683 int
 684 dasd_term_IO(struct dasd_ccw_req * cqr)
 685 {
 686         struct dasd_device *device;
 687         int retries, rc;
 688
 689         /* Check the cqr */
 690         rc = dasd_check_cqr(cqr);
 691         if (rc)
 692                 return rc;
 693         retries = 0;
 694         device = (struct dasd_device *) cqr->device;
 695         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
 696                 rc = ccw_device_clear(device->cdev, (long) cqr);
 697                 switch (rc) {
 698                 case 0: /* termination successful */
 699                         cqr->retries--;
 700                         cqr->status = DASD_CQR_CLEAR;
 701                         cqr->stopclk = get_clock();
 702                         DBF_DEV_EVENT(DBF_DEBUG, device,
 703                                       "terminate cqr %p successful",
 704                                       cqr);
 705                         break;
 706                 case -ENODEV:
 707                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 708                                       "device gone, retry");
 709                         break;
 710                 case -EIO:
 711                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 712                                       "I/O error, retry");
 713                         break;
 714                 case -EINVAL:
 715                 case -EBUSY:
 716                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 717                                       "device busy, retry later");
 718                         break;
 719                 default:
 720                         DEV_MESSAGE(KERN_ERR, device,
 721                                     "line %d unknown RC=%d, please "
 722                                     "report to linux390@de.ibm.com",
 723                                     __LINE__, rc);
 724                         BUG();
 725                         break;
 726                 }
 727                 retries++;
 728         }
 729         dasd_schedule_bh(device);
 730         return rc;
 731 }
 732
 733 /*
 734  * Start the i/o. This start_IO can fail if the channel is really busy.
 735  * In that case set up a timer to start the request later.
 736  */
 737 int
 738 dasd_start_IO(struct dasd_ccw_req * cqr)
 739 {
 740         struct dasd_device *device;
 741         int rc;
 742
 743         /* Check the cqr */
 744         rc = dasd_check_cqr(cqr);
 745         if (rc)
 746                 return rc;
 747         device = (struct dasd_device *) cqr->device;
 748         if (cqr->retries < 0) {
 749                 DEV_MESSAGE(KERN_DEBUG, device,
 750                             "start_IO: request %p (%02x/%i) - no retry left.",
 751                             cqr, cqr->status, cqr->retries);
 752                 cqr->status = DASD_CQR_FAILED;
 753                 return -EIO;
 754         }
 755         cqr->startclk = get_clock();
 756         cqr->starttime = jiffies;
 757         cqr->retries--;
 758         rc = ccw_device_start(device->cdev, cqr->cpaddr, (long) cqr,
 759                               cqr->lpm, 0);
 760         switch (rc) {
 761         case 0:
 762                 cqr->status = DASD_CQR_IN_IO;
 763                 DBF_DEV_EVENT(DBF_DEBUG, device,
 764                               "start_IO: request %p started successful",
 765                               cqr);
 766                 break;
 767         case -EBUSY:
 768                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 769                               "start_IO: device busy, retry later");
 770                 break;
 771         case -ETIMEDOUT:
 772                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 773                               "start_IO: request timeout, retry later");
 774                 break;
 775         case -EACCES:
 776                 /* -EACCES indicates that the request used only a
 777                  * subset of the available pathes and all these
 778                  * pathes are gone.
 779                  * Do a retry with all available pathes.
 780                  */
 781                 cqr->lpm = LPM_ANYPATH;
 782                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 783                               "start_IO: selected pathes gone,"
 784                               " retry on all pathes");
 785                 break;
 786         case -ENODEV:
 787         case -EIO:
 788                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 789                               "start_IO: device gone, retry");
 790                 break;
 791         default:
 792                 DEV_MESSAGE(KERN_ERR, device,
 793                             "line %d unknown RC=%d, please report"
 794                             " to linux390@de.ibm.com", __LINE__, rc);
 795                 BUG();
 796                 break;
 797         }
 798         return rc;
 799 }
 800
 801 /*
 802  * Timeout function for dasd devices. This is used for different purposes
 803  *  1) missing interrupt handler for normal operation
 804  *  2) delayed start of request where start_IO failed with -EBUSY
 805  *  3) timeout for missing state change interrupts
 806  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
 807  * DASD_CQR_QUEUED for 2) and 3).
 808  */
 809 static void
 810 dasd_timeout_device(unsigned long ptr)
 811 {
 812         unsigned long flags;
 813         struct dasd_device *device;
 814
 815         device = (struct dasd_device *) ptr;
 816         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
 817         /* re-activate request queue */
 818         device->stopped &= ~DASD_STOPPED_PENDING;
 819         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
 820         dasd_schedule_bh(device);
 821 }
 822
 823 /*
 824  * Setup timeout for a device in jiffies.
 825  */
 826 void
 827 dasd_set_timer(struct dasd_device *device, int expires)
 828 {
 829         if (expires == 0) {
 830                 if (timer_pending(&device->timer))
 831                         del_timer(&device->timer);
 832                 return;
 833         }
 834         if (timer_pending(&device->timer)) {
 835                 if (mod_timer(&device->timer, jiffies + expires))
 836                         return;
 837         }
 838         device->timer.function = dasd_timeout_device;
 839         device->timer.data = (unsigned long) device;
 840         device->timer.expires = jiffies + expires;
 841         add_timer(&device->timer);
 842 }
 843
 844 /*
 845  * Clear timeout for a device.
 846  */
 847 void
 848 dasd_clear_timer(struct dasd_device *device)
 849 {
 850         if (timer_pending(&device->timer))
 851                 del_timer(&device->timer);
 852 }
 853
 854 static void
 855 dasd_handle_killed_request(struct ccw_device *cdev, unsigned long intparm)
 856 {
 857         struct dasd_ccw_req *cqr;
 858         struct dasd_device *device;
 859
 860         cqr = (struct dasd_ccw_req *) intparm;
 861         if (cqr->status != DASD_CQR_IN_IO) {
 862                 MESSAGE(KERN_DEBUG,
 863                         "invalid status in handle_killed_request: "
 864                         "bus_id %s, status %02x",
 865                         cdev->dev.bus_id, cqr->status);
 866                 return;
 867         }
 868
 869         device = (struct dasd_device *) cqr->device;
 870         if (device == NULL ||
 871             device != dasd_device_from_cdev(cdev) ||
 872             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
 873                 MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
 874                         cdev->dev.bus_id);
 875                 return;
 876         }
 877
 878         /* Schedule request to be retried. */
 879         cqr->status = DASD_CQR_QUEUED;
 880
 881         dasd_clear_timer(device);
 882         dasd_schedule_bh(device);
 883         dasd_put_device(device);
 884 }
 885
 886 static void
 887 dasd_handle_state_change_pending(struct dasd_device *device)
 888 {
 889         struct dasd_ccw_req *cqr;
 890         struct list_head *l, *n;
 891
 892         /* First of all start sense subsystem status request. */
 893         dasd_eer_snss(device);
 894
 895         device->stopped &= ~DASD_STOPPED_PENDING;
 896
 897         /* restart all 'running' IO on queue */
 898         list_for_each_safe(l, n, &device->ccw_queue) {
 899                 cqr = list_entry(l, struct dasd_ccw_req, list);
 900                 if (cqr->status == DASD_CQR_IN_IO) {
 901                         cqr->status = DASD_CQR_QUEUED;
 902                 }
 903         }
 904         dasd_clear_timer(device);
 905         dasd_schedule_bh(device);
 906 }
 907
 908 /*
 909  * Interrupt handler for "normal" ssch-io based dasd devices.
 910  */
 911 void
 912 dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
 913                  struct irb *irb)
 914 {
 915         struct dasd_ccw_req *cqr, *next;
 916         struct dasd_device *device;
 917         unsigned long long now;
 918         int expires;
 919         dasd_era_t era;
 920         char mask;
 921
 922         if (IS_ERR(irb)) {
 923                 switch (PTR_ERR(irb)) {
 924                 case -EIO:
 925                         dasd_handle_killed_request(cdev, intparm);
 926                         break;
 927                 case -ETIMEDOUT:
 928                         printk(KERN_WARNING"%s(%s): request timed out\n",
 929                                __FUNCTION__, cdev->dev.bus_id);
 930                         //FIXME - dasd uses own timeout interface...
 931                         break;
 932                 default:
 933                         printk(KERN_WARNING"%s(%s): unknown error %ld\n",
 934                                __FUNCTION__, cdev->dev.bus_id, PTR_ERR(irb));
 935                 }
 936                 return;
 937         }
 938
 939         now = get_clock();
 940
 941         DBF_EVENT(DBF_ERR, "Interrupt: bus_id %s CS/DS %04x ip %08x",
 942                   cdev->dev.bus_id, ((irb->scsw.cstat<<8)|irb->scsw.dstat),
 943                   (unsigned int) intparm);
 944
 945         /* first of all check for state change pending interrupt */
 946         mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP;
 947         if ((irb->scsw.dstat & mask) == mask) {
 948                 device = dasd_device_from_cdev(cdev);
 949                 if (!IS_ERR(device)) {
 950                         dasd_handle_state_change_pending(device);
 951                         dasd_put_device(device);
 952                 }
 953                 return;
 954         }
 955
 956         cqr = (struct dasd_ccw_req *) intparm;
 957
 958         /* check for unsolicited interrupts */
 959         if (cqr == NULL) {
 960                 MESSAGE(KERN_DEBUG,
 961                         "unsolicited interrupt received: bus_id %s",
 962                         cdev->dev.bus_id);
 963                 return;
 964         }
 965
 966         device = (struct dasd_device *) cqr->device;
 967         if (device == NULL ||
 968             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
 969                 MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
 970                         cdev->dev.bus_id);
 971                 return;
 972         }
 973
 974         /* Check for clear pending */
 975         if (cqr->status == DASD_CQR_CLEAR &&
 976             irb->scsw.fctl & SCSW_FCTL_CLEAR_FUNC) {
 977                 cqr->status = DASD_CQR_QUEUED;
 978                 dasd_clear_timer(device);
 979                 dasd_schedule_bh(device);
 980                 return;
 981         }
 982
 983         /* check status - the request might have been killed by dyn detach */
 984         if (cqr->status != DASD_CQR_IN_IO) {
 985                 MESSAGE(KERN_DEBUG,
 986                         "invalid status: bus_id %s, status %02x",
 987                         cdev->dev.bus_id, cqr->status);
 988                 return;
 989         }
 990         DBF_DEV_EVENT(DBF_DEBUG, device, "Int: CS/DS 0x%04x for cqr %p",
 991                       ((irb->scsw.cstat << 8) | irb->scsw.dstat), cqr);
 992
 993         /* Find out the appropriate era_action. */
 994         if (irb->scsw.fctl & SCSW_FCTL_HALT_FUNC)
 995                 era = dasd_era_fatal;
 996         else if (irb->scsw.dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
 997                  irb->scsw.cstat == 0 &&
 998                  !irb->esw.esw0.erw.cons)
 999                 era = dasd_era_none;
1000         else if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags))
1001                 era = dasd_era_fatal; /* don't recover this request */
1002         else if (irb->esw.esw0.erw.cons)
1003                 era = device->discipline->examine_error(cqr, irb);
1004         else
1005                 era = dasd_era_recover;
1006
1007         DBF_DEV_EVENT(DBF_DEBUG, device, "era_code %d", era);
1008         expires = 0;
1009         if (era == dasd_era_none) {
1010                 cqr->status = DASD_CQR_DONE;
1011                 cqr->stopclk = now;
1012                 /* Start first request on queue if possible -> fast_io. */
1013                 if (cqr->list.next != &device->ccw_queue) {
1014                         next = list_entry(cqr->list.next,
1015                                           struct dasd_ccw_req, list);
1016                         if ((next->status == DASD_CQR_QUEUED) &&
1017                             (!device->stopped)) {
1018                                 if (device->discipline->start_IO(next) == 0)
1019                                         expires = next->expires;
1020                                 else
1021                                         DEV_MESSAGE(KERN_DEBUG, device, "%s",
1022                                                     "Interrupt fastpath "
1023                                                     "failed!");
1024                         }
1025                 }
1026         } else {                /* error */
1027                 memcpy(&cqr->irb, irb, sizeof (struct irb));
1028 #ifdef ERP_DEBUG
1029                 /* dump sense data */
1030                 dasd_log_sense(cqr, irb);
1031 #endif
1032                 switch (era) {
1033                 case dasd_era_fatal:
1034                         cqr->status = DASD_CQR_FAILED;
1035                         cqr->stopclk = now;
1036                         break;
1037                 case dasd_era_recover:
1038                         cqr->status = DASD_CQR_ERROR;
1039                         break;
1040                 default:
1041                         BUG();
1042                 }
1043         }
1044         if (expires != 0)
1045                 dasd_set_timer(device, expires);
1046         else
1047                 dasd_clear_timer(device);
1048         dasd_schedule_bh(device);
1049 }
1050
1051 /*
1052  * posts the buffer_cache about a finalized request
1053  */
1054 static inline void
1055 dasd_end_request(struct request *req, int uptodate)
1056 {
1057         if (end_that_request_first(req, uptodate, req->hard_nr_sectors))
1058                 BUG();
1059         add_disk_randomness(req->rq_disk);
1060         end_that_request_last(req, uptodate);
1061 }
1062
1063 /*
1064  * Process finished error recovery ccw.
1065  */
1066 static inline void
1067 __dasd_process_erp(struct dasd_device *device, struct dasd_ccw_req *cqr)
1068 {
1069         dasd_erp_fn_t erp_fn;
1070
1071         if (cqr->status == DASD_CQR_DONE)
1072                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
1073         else
1074                 DEV_MESSAGE(KERN_ERR, device, "%s", "ERP unsuccessful");
1075         erp_fn = device->discipline->erp_postaction(cqr);
1076         erp_fn(cqr);
1077 }
1078
1079 /*
1080  * Process ccw request queue.
1081  */
1082 static inline void
1083 __dasd_process_ccw_queue(struct dasd_device * device,
1084                          struct list_head *final_queue)
1085 {
1086         struct list_head *l, *n;
1087         struct dasd_ccw_req *cqr;
1088         dasd_erp_fn_t erp_fn;
1089
1090 restart:
1091         /* Process request with final status. */
1092         list_for_each_safe(l, n, &device->ccw_queue) {
1093                 cqr = list_entry(l, struct dasd_ccw_req, list);
1094                 /* Stop list processing at the first non-final request. */
1095                 if (cqr->status != DASD_CQR_DONE &&
1096                     cqr->status != DASD_CQR_FAILED &&
1097                     cqr->status != DASD_CQR_ERROR)
1098                         break;
1099                 /*  Process requests with DASD_CQR_ERROR */
1100                 if (cqr->status == DASD_CQR_ERROR) {
1101                         if (cqr->irb.scsw.fctl & SCSW_FCTL_HALT_FUNC) {
1102                                 cqr->status = DASD_CQR_FAILED;
1103                                 cqr->stopclk = get_clock();
1104                         } else {
1105                                 if (cqr->irb.esw.esw0.erw.cons) {
1106                                         erp_fn = device->discipline->
1107                                                 erp_action(cqr);
1108                                         erp_fn(cqr);
1109                                 } else
1110                                         dasd_default_erp_action(cqr);
1111                         }
1112                         goto restart;
1113                 }
1114
1115                 /* First of all call extended error reporting. */
1116                 if (dasd_eer_enabled(device) &&
1117                     cqr->status == DASD_CQR_FAILED) {
1118                         dasd_eer_write(device, cqr, DASD_EER_FATALERROR);
1119
1120                         /* restart request  */
1121                         cqr->status = DASD_CQR_QUEUED;
1122                         cqr->retries = 255;
1123                         device->stopped |= DASD_STOPPED_QUIESCE;
1124                         goto restart;
1125                 }
1126
1127                 /* Process finished ERP request. */
1128                 if (cqr->refers) {
1129                         __dasd_process_erp(device, cqr);
1130                         goto restart;
1131                 }
1132
1133                 /* Rechain finished requests to final queue */
1134                 cqr->endclk = get_clock();
1135                 list_move_tail(&cqr->list, final_queue);
1136         }
1137 }
1138
1139 static void
1140 dasd_end_request_cb(struct dasd_ccw_req * cqr, void *data)
1141 {
1142         struct request *req;
1143         struct dasd_device *device;
1144         int status;
1145
1146         req = (struct request *) data;
1147         device = cqr->device;
1148         dasd_profile_end(device, cqr, req);
1149         status = cqr->device->discipline->free_cp(cqr,req);
1150         spin_lock_irq(&device->request_queue_lock);
1151         dasd_end_request(req, status);
1152         spin_unlock_irq(&device->request_queue_lock);
1153 }
1154
1155
1156 /*
1157  * Fetch requests from the block device queue.
1158  */
1159 static inline void
1160 __dasd_process_blk_queue(struct dasd_device * device)
1161 {
1162         request_queue_t *queue;
1163         struct request *req;
1164         struct dasd_ccw_req *cqr;
1165         int nr_queued;
1166
1167         queue = device->request_queue;
1168         /* No queue ? Then there is nothing to do. */
1169         if (queue == NULL)
1170                 return;
1171
1172         /*
1173          * We requeue request from the block device queue to the ccw
1174          * queue only in two states. In state DASD_STATE_READY the
1175          * partition detection is done and we need to requeue requests
1176          * for that. State DASD_STATE_ONLINE is normal block device
1177          * operation.
1178          */
1179         if (device->state != DASD_STATE_READY &&
1180             device->state != DASD_STATE_ONLINE)
1181                 return;
1182         nr_queued = 0;
1183         /* Now we try to fetch requests from the request queue */
1184         list_for_each_entry(cqr, &device->ccw_queue, list)
1185                 if (cqr->status == DASD_CQR_QUEUED)
1186                         nr_queued++;
1187         while (!blk_queue_plugged(queue) &&
1188                elv_next_request(queue) &&
1189                 nr_queued < DASD_CHANQ_MAX_SIZE) {
1190                 req = elv_next_request(queue);
1191
1192                 if (device->features & DASD_FEATURE_READONLY &&
1193                     rq_data_dir(req) == WRITE) {
1194                         DBF_DEV_EVENT(DBF_ERR, device,
1195                                       "Rejecting write request %p",
1196                                       req);
1197                         blkdev_dequeue_request(req);
1198                         dasd_end_request(req, 0);
1199                         continue;
1200                 }
1201                 if (device->stopped & DASD_STOPPED_DC_EIO) {
1202                         blkdev_dequeue_request(req);
1203                         dasd_end_request(req, 0);
1204                         continue;
1205                 }
1206                 cqr = device->discipline->build_cp(device, req);
1207                 if (IS_ERR(cqr)) {
1208                         if (PTR_ERR(cqr) == -ENOMEM)
1209                                 break;  /* terminate request queue loop */
1210                         DBF_DEV_EVENT(DBF_ERR, device,
1211                                       "CCW creation failed (rc=%ld) "
1212                                       "on request %p",
1213                                       PTR_ERR(cqr), req);
1214                         blkdev_dequeue_request(req);
1215                         dasd_end_request(req, 0);
1216                         continue;
1217                 }
1218                 cqr->callback = dasd_end_request_cb;
1219                 cqr->callback_data = (void *) req;
1220                 cqr->status = DASD_CQR_QUEUED;
1221                 blkdev_dequeue_request(req);
1222                 list_add_tail(&cqr->list, &device->ccw_queue);
1223                 dasd_profile_start(device, cqr, req);
1224                 nr_queued++;
1225         }
1226 }
1227
1228 /*
1229  * Take a look at the first request on the ccw queue and check
1230  * if it reached its expire time. If so, terminate the IO.
1231  */
1232 static inline void
1233 __dasd_check_expire(struct dasd_device * device)
1234 {
1235         struct dasd_ccw_req *cqr;
1236
1237         if (list_empty(&device->ccw_queue))
1238                 return;
1239         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1240         if (cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) {
1241                 if (time_after_eq(jiffies, cqr->expires + cqr->starttime)) {
1242                         if (device->discipline->term_IO(cqr) != 0)
1243                                 /* Hmpf, try again in 1/10 sec */
1244                                 dasd_set_timer(device, 10);
1245                 }
1246         }
1247 }
1248
1249 /*
1250  * Take a look at the first request on the ccw queue and check
1251  * if it needs to be started.
1252  */
1253 static inline void
1254 __dasd_start_head(struct dasd_device * device)
1255 {
1256         struct dasd_ccw_req *cqr;
1257         int rc;
1258
1259         if (list_empty(&device->ccw_queue))
1260                 return;
1261         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1262         /* check FAILFAST */
1263         if (device->stopped & ~DASD_STOPPED_PENDING &&
1264             test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
1265             (!dasd_eer_enabled(device))) {
1266                 cqr->status = DASD_CQR_FAILED;
1267                 dasd_schedule_bh(device);
1268         }
1269         if ((cqr->status == DASD_CQR_QUEUED) &&
1270             (!device->stopped)) {
1271                 /* try to start the first I/O that can be started */
1272                 rc = device->discipline->start_IO(cqr);
1273                 if (rc == 0)
1274                         dasd_set_timer(device, cqr->expires);
1275                 else if (rc == -EACCES) {
1276                         dasd_schedule_bh(device);
1277                 } else
1278                         /* Hmpf, try again in 1/2 sec */
1279                         dasd_set_timer(device, 50);
1280         }
1281 }
1282
1283 /*
1284  * Remove requests from the ccw queue.
1285  */
1286 static void
1287 dasd_flush_ccw_queue(struct dasd_device * device, int all)
1288 {
1289         struct list_head flush_queue;
1290         struct list_head *l, *n;
1291         struct dasd_ccw_req *cqr;
1292
1293         INIT_LIST_HEAD(&flush_queue);
1294         spin_lock_irq(get_ccwdev_lock(device->cdev));
1295         list_for_each_safe(l, n, &device->ccw_queue) {
1296                 cqr = list_entry(l, struct dasd_ccw_req, list);
1297                 /* Flush all request or only block device requests? */
1298                 if (all == 0 && cqr->callback == dasd_end_request_cb)
1299                         continue;
1300                 if (cqr->status == DASD_CQR_IN_IO)
1301                         device->discipline->term_IO(cqr);
1302                 if (cqr->status != DASD_CQR_DONE ||
1303                     cqr->status != DASD_CQR_FAILED) {
1304                         cqr->status = DASD_CQR_FAILED;
1305                         cqr->stopclk = get_clock();
1306                 }
1307                 /* Process finished ERP request. */
1308                 if (cqr->refers) {
1309                         __dasd_process_erp(device, cqr);
1310                         continue;
1311                 }
1312                 /* Rechain request on device request queue */
1313                 cqr->endclk = get_clock();
1314                 list_move_tail(&cqr->list, &flush_queue);
1315         }
1316         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1317         /* Now call the callback function of flushed requests */
1318         list_for_each_safe(l, n, &flush_queue) {
1319                 cqr = list_entry(l, struct dasd_ccw_req, list);
1320                 if (cqr->callback != NULL)
1321                         (cqr->callback)(cqr, cqr->callback_data);
1322         }
1323 }
1324
1325 /*
1326  * Acquire the device lock and process queues for the device.
1327  */
1328 static void
1329 dasd_tasklet(struct dasd_device * device)
1330 {
1331         struct list_head final_queue;
1332         struct list_head *l, *n;
1333         struct dasd_ccw_req *cqr;
1334
1335         atomic_set (&device->tasklet_scheduled, 0);
1336         INIT_LIST_HEAD(&final_queue);
1337         spin_lock_irq(get_ccwdev_lock(device->cdev));
1338         /* Check expire time of first request on the ccw queue. */
1339         __dasd_check_expire(device);
1340         /* Finish off requests on ccw queue */
1341         __dasd_process_ccw_queue(device, &final_queue);
1342         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1343         /* Now call the callback function of requests with final status */
1344         list_for_each_safe(l, n, &final_queue) {
1345                 cqr = list_entry(l, struct dasd_ccw_req, list);
1346                 list_del_init(&cqr->list);
1347                 if (cqr->callback != NULL)
1348                         (cqr->callback)(cqr, cqr->callback_data);
1349         }
1350         spin_lock_irq(&device->request_queue_lock);
1351         spin_lock(get_ccwdev_lock(device->cdev));
1352         /* Get new request from the block device request queue */
1353         __dasd_process_blk_queue(device);
1354         /* Now check if the head of the ccw queue needs to be started. */
1355         __dasd_start_head(device);
1356         spin_unlock(get_ccwdev_lock(device->cdev));
1357         spin_unlock_irq(&device->request_queue_lock);
1358         dasd_put_device(device);
1359 }
1360
1361 /*
1362  * Schedules a call to dasd_tasklet over the device tasklet.
1363  */
1364 void
1365 dasd_schedule_bh(struct dasd_device * device)
1366 {
1367         /* Protect against rescheduling. */
1368         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
1369                 return;
1370         dasd_get_device(device);
1371         tasklet_hi_schedule(&device->tasklet);
1372 }
1373
1374 /*
1375  * Queue a request to the head of the ccw_queue. Start the I/O if
1376  * possible.
1377  */
1378 void
1379 dasd_add_request_head(struct dasd_ccw_req *req)
1380 {
1381         struct dasd_device *device;
1382         unsigned long flags;
1383
1384         device = req->device;
1385         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1386         req->status = DASD_CQR_QUEUED;
1387         req->device = device;
1388         list_add(&req->list, &device->ccw_queue);
1389         /* let the bh start the request to keep them in order */
1390         dasd_schedule_bh(device);
1391         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1392 }
1393
1394 /*
1395  * Queue a request to the tail of the ccw_queue. Start the I/O if
1396  * possible.
1397  */
1398 void
1399 dasd_add_request_tail(struct dasd_ccw_req *req)
1400 {
1401         struct dasd_device *device;
1402         unsigned long flags;
1403
1404         device = req->device;
1405         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1406         req->status = DASD_CQR_QUEUED;
1407         req->device = device;
1408         list_add_tail(&req->list, &device->ccw_queue);
1409         /* let the bh start the request to keep them in order */
1410         dasd_schedule_bh(device);
1411         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1412 }
1413
1414 /*
1415  * Wakeup callback.
1416  */
1417 static void
1418 dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
1419 {
1420         wake_up((wait_queue_head_t *) data);
1421 }
1422
1423 static inline int
1424 _wait_for_wakeup(struct dasd_ccw_req *cqr)
1425 {
1426         struct dasd_device *device;
1427         int rc;
1428
1429         device = cqr->device;
1430         spin_lock_irq(get_ccwdev_lock(device->cdev));
1431         rc = ((cqr->status == DASD_CQR_DONE ||
1432                cqr->status == DASD_CQR_FAILED) &&
1433               list_empty(&cqr->list));
1434         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1435         return rc;
1436 }
1437
1438 /*
1439  * Attempts to start a special ccw queue and waits for its completion.
1440  */
1441 int
1442 dasd_sleep_on(struct dasd_ccw_req * cqr)
1443 {
1444         wait_queue_head_t wait_q;
1445         struct dasd_device *device;
1446         int rc;
1447
1448         device = cqr->device;
1449         spin_lock_irq(get_ccwdev_lock(device->cdev));
1450
1451         init_waitqueue_head (&wait_q);
1452         cqr->callback = dasd_wakeup_cb;
1453         cqr->callback_data = (void *) &wait_q;
1454         cqr->status = DASD_CQR_QUEUED;
1455         list_add_tail(&cqr->list, &device->ccw_queue);
1456
1457         /* let the bh start the request to keep them in order */
1458         dasd_schedule_bh(device);
1459
1460         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1461
1462         wait_event(wait_q, _wait_for_wakeup(cqr));
1463
1464         /* Request status is either done or failed. */
1465         rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1466         return rc;
1467 }
1468
1469 /*
1470  * Attempts to start a special ccw queue and wait interruptible
1471  * for its completion.
1472  */
1473 int
1474 dasd_sleep_on_interruptible(struct dasd_ccw_req * cqr)
1475 {
1476         wait_queue_head_t wait_q;
1477         struct dasd_device *device;
1478         int rc, finished;
1479
1480         device = cqr->device;
1481         spin_lock_irq(get_ccwdev_lock(device->cdev));
1482
1483         init_waitqueue_head (&wait_q);
1484         cqr->callback = dasd_wakeup_cb;
1485         cqr->callback_data = (void *) &wait_q;
1486         cqr->status = DASD_CQR_QUEUED;
1487         list_add_tail(&cqr->list, &device->ccw_queue);
1488
1489         /* let the bh start the request to keep them in order */
1490         dasd_schedule_bh(device);
1491         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1492
1493         finished = 0;
1494         while (!finished) {
1495                 rc = wait_event_interruptible(wait_q, _wait_for_wakeup(cqr));
1496                 if (rc != -ERESTARTSYS) {
1497                         /* Request is final (done or failed) */
1498                         rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO;
1499                         break;
1500                 }
1501                 spin_lock_irq(get_ccwdev_lock(device->cdev));
1502                 switch (cqr->status) {
1503                 case DASD_CQR_IN_IO:
1504                         /* terminate runnig cqr */
1505                         if (device->discipline->term_IO) {
1506                                 cqr->retries = -1;
1507                                 device->discipline->term_IO(cqr);
1508                                 /*nished =
1509                                  * wait (non-interruptible) for final status
1510                                  * because signal ist still pending
1511                                  */
1512                                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1513                                 wait_event(wait_q, _wait_for_wakeup(cqr));
1514                                 spin_lock_irq(get_ccwdev_lock(device->cdev));
1515                                 rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO;
1516                                 finished = 1;
1517                         }
1518                         break;
1519                 case DASD_CQR_QUEUED:
1520                         /* request  */
1521                         list_del_init(&cqr->list);
1522                         rc = -EIO;
1523                         finished = 1;
1524                         break;
1525                 default:
1526                         /* cqr with 'non-interruptable' status - just wait */
1527                         break;
1528                 }
1529                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1530         }
1531         return rc;
1532 }
1533
1534 /*
1535  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
1536  * for eckd devices) the currently running request has to be terminated
1537  * and be put back to status queued, before the special request is added
1538  * to the head of the queue. Then the special request is waited on normally.
1539  */
1540 static inline int
1541 _dasd_term_running_cqr(struct dasd_device *device)
1542 {
1543         struct dasd_ccw_req *cqr;
1544         int rc;
1545
1546         if (list_empty(&device->ccw_queue))
1547                 return 0;
1548         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1549         rc = device->discipline->term_IO(cqr);
1550         if (rc == 0) {
1551                 /* termination successful */
1552                 cqr->status = DASD_CQR_QUEUED;
1553                 cqr->startclk = cqr->stopclk = 0;
1554                 cqr->starttime = 0;
1555         }
1556         return rc;
1557 }
1558
1559 int
1560 dasd_sleep_on_immediatly(struct dasd_ccw_req * cqr)
1561 {
1562         wait_queue_head_t wait_q;
1563         struct dasd_device *device;
1564         int rc;
1565
1566         device = cqr->device;
1567         spin_lock_irq(get_ccwdev_lock(device->cdev));
1568         rc = _dasd_term_running_cqr(device);
1569         if (rc) {
1570                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1571                 return rc;
1572         }
1573
1574         init_waitqueue_head (&wait_q);
1575         cqr->callback = dasd_wakeup_cb;
1576         cqr->callback_data = (void *) &wait_q;
1577         cqr->status = DASD_CQR_QUEUED;
1578         list_add(&cqr->list, &device->ccw_queue);
1579
1580         /* let the bh start the request to keep them in order */
1581         dasd_schedule_bh(device);
1582
1583         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1584
1585         wait_event(wait_q, _wait_for_wakeup(cqr));
1586
1587         /* Request status is either done or failed. */
1588         rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1589         return rc;
1590 }
1591
1592 /*
1593  * Cancels a request that was started with dasd_sleep_on_req.
1594  * This is useful to timeout requests. The request will be
1595  * terminated if it is currently in i/o.
1596  * Returns 1 if the request has been terminated.
1597  */
1598 int
1599 dasd_cancel_req(struct dasd_ccw_req *cqr)
1600 {
1601         struct dasd_device *device = cqr->device;
1602         unsigned long flags;
1603         int rc;
1604
1605         rc = 0;
1606         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1607         switch (cqr->status) {
1608         case DASD_CQR_QUEUED:
1609                 /* request was not started - just set to failed */
1610                 cqr->status = DASD_CQR_FAILED;
1611                 break;
1612         case DASD_CQR_IN_IO:
1613                 /* request in IO - terminate IO and release again */
1614                 if (device->discipline->term_IO(cqr) != 0)
1615                         /* what to do if unable to terminate ??????
1616                            e.g. not _IN_IO */
1617                         cqr->status = DASD_CQR_FAILED;
1618                 cqr->stopclk = get_clock();
1619                 rc = 1;
1620                 break;
1621         case DASD_CQR_DONE:
1622         case DASD_CQR_FAILED:
1623                 /* already finished - do nothing */
1624                 break;
1625         default:
1626                 DEV_MESSAGE(KERN_ALERT, device,
1627                             "invalid status %02x in request",
1628                             cqr->status);
1629                 BUG();
1630
1631         }
1632         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1633         dasd_schedule_bh(device);
1634         return rc;
1635 }
1636
1637 /*
1638  * SECTION: Block device operations (request queue, partitions, open, release).
1639  */
1640
1641 /*
1642  * Dasd request queue function. Called from ll_rw_blk.c
1643  */
1644 static void
1645 do_dasd_request(request_queue_t * queue)
1646 {
1647         struct dasd_device *device;
1648
1649         device = (struct dasd_device *) queue->queuedata;
1650         spin_lock(get_ccwdev_lock(device->cdev));
1651         /* Get new request from the block device request queue */
1652         __dasd_process_blk_queue(device);
1653         /* Now check if the head of the ccw queue needs to be started. */
1654         __dasd_start_head(device);
1655         spin_unlock(get_ccwdev_lock(device->cdev));
1656 }
1657
1658 /*
1659  * Allocate and initialize request queue and default I/O scheduler.
1660  */
1661 static int
1662 dasd_alloc_queue(struct dasd_device * device)
1663 {
1664         int rc;
1665
1666         device->request_queue = blk_init_queue(do_dasd_request,
1667                                                &device->request_queue_lock);
1668         if (device->request_queue == NULL)
1669                 return -ENOMEM;
1670
1671         device->request_queue->queuedata = device;
1672
1673         elevator_exit(device->request_queue->elevator);
1674         rc = elevator_init(device->request_queue, "deadline");
1675         if (rc) {
1676                 blk_cleanup_queue(device->request_queue);
1677                 return rc;
1678         }
1679         return 0;
1680 }
1681
1682 /*
1683  * Allocate and initialize request queue.
1684  */
1685 static void
1686 dasd_setup_queue(struct dasd_device * device)
1687 {
1688         int max;
1689
1690         blk_queue_hardsect_size(device->request_queue, device->bp_block);
1691         max = device->discipline->max_blocks << device->s2b_shift;
1692         blk_queue_max_sectors(device->request_queue, max);
1693         blk_queue_max_phys_segments(device->request_queue, -1L);
1694         blk_queue_max_hw_segments(device->request_queue, -1L);
1695         blk_queue_max_segment_size(device->request_queue, -1L);
1696         blk_queue_segment_boundary(device->request_queue, -1L);
1697         blk_queue_ordered(device->request_queue, QUEUE_ORDERED_TAG, NULL);
1698 }
1699
1700 /*
1701  * Deactivate and free request queue.
1702  */
1703 static void
1704 dasd_free_queue(struct dasd_device * device)
1705 {
1706         if (device->request_queue) {
1707                 blk_cleanup_queue(device->request_queue);
1708                 device->request_queue = NULL;
1709         }
1710 }
1711
1712 /*
1713  * Flush request on the request queue.
1714  */
1715 static void
1716 dasd_flush_request_queue(struct dasd_device * device)
1717 {
1718         struct request *req;
1719
1720         if (!device->request_queue)
1721                 return;
1722
1723         spin_lock_irq(&device->request_queue_lock);
1724         while (!list_empty(&device->request_queue->queue_head)) {
1725                 req = elv_next_request(device->request_queue);
1726                 if (req == NULL)
1727                         break;
1728                 dasd_end_request(req, 0);
1729                 blkdev_dequeue_request(req);
1730         }
1731         spin_unlock_irq(&device->request_queue_lock);
1732 }
1733
1734 static int
1735 dasd_open(struct inode *inp, struct file *filp)
1736 {
1737         struct gendisk *disk = inp->i_bdev->bd_disk;
1738         struct dasd_device *device = disk->private_data;
1739         int rc;
1740
1741         atomic_inc(&device->open_count);
1742         if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1743                 rc = -ENODEV;
1744                 goto unlock;
1745         }
1746
1747         if (!try_module_get(device->discipline->owner)) {
1748                 rc = -EINVAL;
1749                 goto unlock;
1750         }
1751
1752         if (dasd_probeonly) {
1753                 DEV_MESSAGE(KERN_INFO, device, "%s",
1754                             "No access to device due to probeonly mode");
1755                 rc = -EPERM;
1756                 goto out;
1757         }
1758
1759         if (device->state <= DASD_STATE_BASIC) {
1760                 DBF_DEV_EVENT(DBF_ERR, device, " %s",
1761                               " Cannot open unrecognized device");
1762                 rc = -ENODEV;
1763                 goto out;
1764         }
1765
1766         return 0;
1767
1768 out:
1769         module_put(device->discipline->owner);
1770 unlock:
1771         atomic_dec(&device->open_count);
1772         return rc;
1773 }
1774
1775 static int
1776 dasd_release(struct inode *inp, struct file *filp)
1777 {
1778         struct gendisk *disk = inp->i_bdev->bd_disk;
1779         struct dasd_device *device = disk->private_data;
1780
1781         atomic_dec(&device->open_count);
1782         module_put(device->discipline->owner);
1783         return 0;
1784 }
1785
1786 /*
1787  * Return disk geometry.
1788  */
1789 static int
1790 dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
1791 {
1792         struct dasd_device *device;
1793
1794         device = bdev->bd_disk->private_data;
1795         if (!device)
1796                 return -ENODEV;
1797
1798         if (!device->discipline ||
1799             !device->discipline->fill_geometry)
1800                 return -EINVAL;
1801
1802         device->discipline->fill_geometry(device, geo);
1803         geo->start = get_start_sect(bdev) >> device->s2b_shift;
1804         return 0;
1805 }
1806
1807 struct block_device_operations
1808 dasd_device_operations = {
1809         .owner          = THIS_MODULE,
1810         .open           = dasd_open,
1811         .release        = dasd_release,
1812         .ioctl          = dasd_ioctl,
1813         .compat_ioctl   = dasd_compat_ioctl,
1814         .getgeo         = dasd_getgeo,
1815 };
1816
1817
1818 static void
1819 dasd_exit(void)
1820 {
1821 #ifdef CONFIG_PROC_FS
1822         dasd_proc_exit();
1823 #endif
1824         dasd_eer_exit();
1825         if (dasd_page_cache != NULL) {
1826                 kmem_cache_destroy(dasd_page_cache);
1827                 dasd_page_cache = NULL;
1828         }
1829         dasd_gendisk_exit();
1830         dasd_devmap_exit();
1831         devfs_remove("dasd");
1832         if (dasd_debug_area != NULL) {
1833                 debug_unregister(dasd_debug_area);
1834                 dasd_debug_area = NULL;
1835         }
1836 }
1837
1838 /*
1839  * SECTION: common functions for ccw_driver use
1840  */
1841
1842 /*
1843  * Initial attempt at a probe function. this can be simplified once
1844  * the other detection code is gone.
1845  */
1846 int
1847 dasd_generic_probe (struct ccw_device *cdev,
1848                     struct dasd_discipline *discipline)
1849 {
1850         int ret;
1851
1852         ret = dasd_add_sysfs_files(cdev);
1853         if (ret) {
1854                 printk(KERN_WARNING
1855                        "dasd_generic_probe: could not add sysfs entries "
1856                        "for %s\n", cdev->dev.bus_id);
1857         } else {
1858                 cdev->handler = &dasd_int_handler;
1859         }
1860
1861         return ret;
1862 }
1863
1864 /*
1865  * This will one day be called from a global not_oper handler.
1866  * It is also used by driver_unregister during module unload.
1867  */
1868 void
1869 dasd_generic_remove (struct ccw_device *cdev)
1870 {
1871         struct dasd_device *device;
1872
1873         cdev->handler = NULL;
1874
1875         dasd_remove_sysfs_files(cdev);
1876         device = dasd_device_from_cdev(cdev);
1877         if (IS_ERR(device))
1878                 return;
1879         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1880                 /* Already doing offline processing */
1881                 dasd_put_device(device);
1882                 return;
1883         }
1884         /*
1885          * This device is removed unconditionally. Set offline
1886          * flag to prevent dasd_open from opening it while it is
1887          * no quite down yet.
1888          */
1889         dasd_set_target_state(device, DASD_STATE_NEW);
1890         /* dasd_delete_device destroys the device reference. */
1891         dasd_delete_device(device);
1892 }
1893
1894 /*
1895  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
1896  * the device is detected for the first time and is supposed to be used
1897  * or the user has started activation through sysfs.
1898  */
1899 int
1900 dasd_generic_set_online (struct ccw_device *cdev,
1901                          struct dasd_discipline *base_discipline)
1902
1903 {
1904         struct dasd_discipline *discipline;
1905         struct dasd_device *device;
1906         int rc;
1907
1908         device = dasd_create_device(cdev);
1909         if (IS_ERR(device))
1910                 return PTR_ERR(device);
1911
1912         discipline = base_discipline;
1913         if (device->features & DASD_FEATURE_USEDIAG) {
1914                 if (!dasd_diag_discipline_pointer) {
1915                         printk (KERN_WARNING
1916                                 "dasd_generic couldn't online device %s "
1917                                 "- discipline DIAG not available\n",
1918                                 cdev->dev.bus_id);
1919                         dasd_delete_device(device);
1920                         return -ENODEV;
1921                 }
1922                 discipline = dasd_diag_discipline_pointer;
1923         }
1924         if (!try_module_get(base_discipline->owner)) {
1925                 dasd_delete_device(device);
1926                 return -EINVAL;
1927         }
1928         if (!try_module_get(discipline->owner)) {
1929                 module_put(base_discipline->owner);
1930                 dasd_delete_device(device);
1931                 return -EINVAL;
1932         }
1933         device->base_discipline = base_discipline;
1934         device->discipline = discipline;
1935
1936         rc = discipline->check_device(device);
1937         if (rc) {
1938                 printk (KERN_WARNING
1939                         "dasd_generic couldn't online device %s "
1940                         "with discipline %s rc=%i\n",
1941                         cdev->dev.bus_id, discipline->name, rc);
1942                 module_put(discipline->owner);
1943                 module_put(base_discipline->owner);
1944                 dasd_delete_device(device);
1945                 return rc;
1946         }
1947
1948         dasd_set_target_state(device, DASD_STATE_ONLINE);
1949         if (device->state <= DASD_STATE_KNOWN) {
1950                 printk (KERN_WARNING
1951                         "dasd_generic discipline not found for %s\n",
1952                         cdev->dev.bus_id);
1953                 rc = -ENODEV;
1954                 dasd_set_target_state(device, DASD_STATE_NEW);
1955                 dasd_delete_device(device);
1956         } else
1957                 pr_debug("dasd_generic device %s found\n",
1958                                 cdev->dev.bus_id);
1959
1960         /* FIXME: we have to wait for the root device but we don't want
1961          * to wait for each single device but for all at once. */
1962         wait_event(dasd_init_waitq, _wait_for_device(device));
1963
1964         dasd_put_device(device);
1965
1966         return rc;
1967 }
1968
1969 int
1970 dasd_generic_set_offline (struct ccw_device *cdev)
1971 {
1972         struct dasd_device *device;
1973         int max_count;
1974
1975         device = dasd_device_from_cdev(cdev);
1976         if (IS_ERR(device))
1977                 return PTR_ERR(device);
1978         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1979                 /* Already doing offline processing */
1980                 dasd_put_device(device);
1981                 return 0;
1982         }
1983         /*
1984          * We must make sure that this device is currently not in use.
1985          * The open_count is increased for every opener, that includes
1986          * the blkdev_get in dasd_scan_partitions. We are only interested
1987          * in the other openers.
1988          */
1989         max_count = device->bdev ? 0 : -1;
1990         if (atomic_read(&device->open_count) > max_count) {
1991                 printk (KERN_WARNING "Can't offline dasd device with open"
1992                         " count = %i.\n",
1993                         atomic_read(&device->open_count));
1994                 clear_bit(DASD_FLAG_OFFLINE, &device->flags);
1995                 dasd_put_device(device);
1996                 return -EBUSY;
1997         }
1998         dasd_set_target_state(device, DASD_STATE_NEW);
1999         /* dasd_delete_device destroys the device reference. */
2000         dasd_delete_device(device);
2001
2002         return 0;
2003 }
2004
2005 int
2006 dasd_generic_notify(struct ccw_device *cdev, int event)
2007 {
2008         struct dasd_device *device;
2009         struct dasd_ccw_req *cqr;
2010         unsigned long flags;
2011         int ret;
2012
2013         device = dasd_device_from_cdev(cdev);
2014         if (IS_ERR(device))
2015                 return 0;
2016         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
2017         ret = 0;
2018         switch (event) {
2019         case CIO_GONE:
2020         case CIO_NO_PATH:
2021                 /* First of all call extended error reporting. */
2022                 dasd_eer_write(device, NULL, DASD_EER_NOPATH);
2023
2024                 if (device->state < DASD_STATE_BASIC)
2025                         break;
2026                 /* Device is active. We want to keep it. */
2027                 if (test_bit(DASD_FLAG_DSC_ERROR, &device->flags)) {
2028                         list_for_each_entry(cqr, &device->ccw_queue, list)
2029                                 if (cqr->status == DASD_CQR_IN_IO)
2030                                         cqr->status = DASD_CQR_FAILED;
2031                         device->stopped |= DASD_STOPPED_DC_EIO;
2032                 } else {
2033                         list_for_each_entry(cqr, &device->ccw_queue, list)
2034                                 if (cqr->status == DASD_CQR_IN_IO) {
2035                                         cqr->status = DASD_CQR_QUEUED;
2036                                         cqr->retries++;
2037                                 }
2038                         device->stopped |= DASD_STOPPED_DC_WAIT;
2039                         dasd_set_timer(device, 0);
2040                 }
2041                 dasd_schedule_bh(device);
2042                 ret = 1;
2043                 break;
2044         case CIO_OPER:
2045                 /* FIXME: add a sanity check. */
2046                 device->stopped &= ~(DASD_STOPPED_DC_WAIT|DASD_STOPPED_DC_EIO);
2047                 dasd_schedule_bh(device);
2048                 ret = 1;
2049                 break;
2050         }
2051         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
2052         dasd_put_device(device);
2053         return ret;
2054 }
2055
2056 /*
2057  * Automatically online either all dasd devices (dasd_autodetect) or
2058  * all devices specified with dasd= parameters.
2059  */
2060 static int
2061 __dasd_auto_online(struct device *dev, void *data)
2062 {
2063         struct ccw_device *cdev;
2064
2065         cdev = to_ccwdev(dev);
2066         if (dasd_autodetect || dasd_busid_known(cdev->dev.bus_id) == 0)
2067                 ccw_device_set_online(cdev);
2068         return 0;
2069 }
2070
2071 void
2072 dasd_generic_auto_online (struct ccw_driver *dasd_discipline_driver)
2073 {
2074         struct device_driver *drv;
2075
2076         drv = get_driver(&dasd_discipline_driver->driver);
2077         driver_for_each_device(drv, NULL, NULL, __dasd_auto_online);
2078         put_driver(drv);
2079 }
2080
2081
2082 static int __init
2083 dasd_init(void)
2084 {
2085         int rc;
2086
2087         init_waitqueue_head(&dasd_init_waitq);
2088
2089         /* register 'common' DASD debug area, used for all DBF_XXX calls */
2090         dasd_debug_area = debug_register("dasd", 1, 2, 8 * sizeof (long));
2091         if (dasd_debug_area == NULL) {
2092                 rc = -ENOMEM;
2093                 goto failed;
2094         }
2095         debug_register_view(dasd_debug_area, &debug_sprintf_view);
2096         debug_set_level(dasd_debug_area, DBF_EMERG);
2097
2098         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
2099
2100         dasd_diag_discipline_pointer = NULL;
2101
2102         rc = devfs_mk_dir("dasd");
2103         if (rc)
2104                 goto failed;
2105         rc = dasd_devmap_init();
2106         if (rc)
2107                 goto failed;
2108         rc = dasd_gendisk_init();
2109         if (rc)
2110                 goto failed;
2111         rc = dasd_parse();
2112         if (rc)
2113                 goto failed;
2114         rc = dasd_eer_init();
2115         if (rc)
2116                 goto failed;
2117 #ifdef CONFIG_PROC_FS
2118         rc = dasd_proc_init();
2119         if (rc)
2120                 goto failed;
2121 #endif
2122
2123         return 0;
2124 failed:
2125         MESSAGE(KERN_INFO, "%s", "initialization not performed due to errors");
2126         dasd_exit();
2127         return rc;
2128 }
2129
2130 module_init(dasd_init);
2131 module_exit(dasd_exit);
2132
2133 EXPORT_SYMBOL(dasd_debug_area);
2134 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
2135
2136 EXPORT_SYMBOL(dasd_add_request_head);
2137 EXPORT_SYMBOL(dasd_add_request_tail);
2138 EXPORT_SYMBOL(dasd_cancel_req);
2139 EXPORT_SYMBOL(dasd_clear_timer);
2140 EXPORT_SYMBOL(dasd_enable_device);
2141 EXPORT_SYMBOL(dasd_int_handler);
2142 EXPORT_SYMBOL(dasd_kfree_request);
2143 EXPORT_SYMBOL(dasd_kick_device);
2144 EXPORT_SYMBOL(dasd_kmalloc_request);
2145 EXPORT_SYMBOL(dasd_schedule_bh);
2146 EXPORT_SYMBOL(dasd_set_target_state);
2147 EXPORT_SYMBOL(dasd_set_timer);
2148 EXPORT_SYMBOL(dasd_sfree_request);
2149 EXPORT_SYMBOL(dasd_sleep_on);
2150 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2151 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2152 EXPORT_SYMBOL(dasd_smalloc_request);
2153 EXPORT_SYMBOL(dasd_start_IO);
2154 EXPORT_SYMBOL(dasd_term_IO);
2155
2156 EXPORT_SYMBOL_GPL(dasd_generic_probe);
2157 EXPORT_SYMBOL_GPL(dasd_generic_remove);
2158 EXPORT_SYMBOL_GPL(dasd_generic_notify);
2159 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
2160 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
2161 EXPORT_SYMBOL_GPL(dasd_generic_auto_online);
2162
2163 /*
2164  * Overrides for Emacs so that we follow Linus's tabbing style.
2165  * Emacs will notice this stuff at the end of the file and automatically
2166  * adjust the settings for this buffer only.  This must remain at the end
2167  * of the file.
2168  * ---------------------------------------------------------------------------
2169  * Local variables:
2170  * c-indent-level: 4
2171  * c-brace-imaginary-offset: 0
2172  * c-brace-offset: -4
2173  * c-argdecl-indent: 4
2174  * c-label-offset: -4
2175  * c-continued-statement-offset: 4
2176  * c-continued-brace-offset: 0
2177  * indent-tabs-mode: 1
2178  * tab-width: 8
2179  * End:
2180  */