git.oblomov.eu Git - linux-2.6/blob - 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         BUG_ON( magic == NULL || datasize > PAGE_SIZE ||
 545              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
 546
 547         cqr = kzalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
 548         if (cqr == NULL)
 549                 return ERR_PTR(-ENOMEM);
 550         cqr->cpaddr = NULL;
 551         if (cplength > 0) {
 552                 cqr->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
 553                                       GFP_ATOMIC | GFP_DMA);
 554                 if (cqr->cpaddr == NULL) {
 555                         kfree(cqr);
 556                         return ERR_PTR(-ENOMEM);
 557                 }
 558         }
 559         cqr->data = NULL;
 560         if (datasize > 0) {
 561                 cqr->data = kzalloc(datasize, GFP_ATOMIC | GFP_DMA);
 562                 if (cqr->data == NULL) {
 563                         kfree(cqr->cpaddr);
 564                         kfree(cqr);
 565                         return ERR_PTR(-ENOMEM);
 566                 }
 567         }
 568         strncpy((char *) &cqr->magic, magic, 4);
 569         ASCEBC((char *) &cqr->magic, 4);
 570         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
 571         dasd_get_device(device);
 572         return cqr;
 573 }
 574
 575 struct dasd_ccw_req *
 576 dasd_smalloc_request(char *magic, int cplength, int datasize,
 577                    struct dasd_device * device)
 578 {
 579         unsigned long flags;
 580         struct dasd_ccw_req *cqr;
 581         char *data;
 582         int size;
 583
 584         /* Sanity checks */
 585         BUG_ON( magic == NULL || datasize > PAGE_SIZE ||
 586              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
 587
 588         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
 589         if (cplength > 0)
 590                 size += cplength * sizeof(struct ccw1);
 591         if (datasize > 0)
 592                 size += datasize;
 593         spin_lock_irqsave(&device->mem_lock, flags);
 594         cqr = (struct dasd_ccw_req *)
 595                 dasd_alloc_chunk(&device->ccw_chunks, size);
 596         spin_unlock_irqrestore(&device->mem_lock, flags);
 597         if (cqr == NULL)
 598                 return ERR_PTR(-ENOMEM);
 599         memset(cqr, 0, sizeof(struct dasd_ccw_req));
 600         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
 601         cqr->cpaddr = NULL;
 602         if (cplength > 0) {
 603                 cqr->cpaddr = (struct ccw1 *) data;
 604                 data += cplength*sizeof(struct ccw1);
 605                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
 606         }
 607         cqr->data = NULL;
 608         if (datasize > 0) {
 609                 cqr->data = data;
 610                 memset(cqr->data, 0, datasize);
 611         }
 612         strncpy((char *) &cqr->magic, magic, 4);
 613         ASCEBC((char *) &cqr->magic, 4);
 614         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
 615         dasd_get_device(device);
 616         return cqr;
 617 }
 618
 619 /*
 620  * Free memory of a channel program. This function needs to free all the
 621  * idal lists that might have been created by dasd_set_cda and the
 622  * struct dasd_ccw_req itself.
 623  */
 624 void
 625 dasd_kfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
 626 {
 627 #ifdef CONFIG_64BIT
 628         struct ccw1 *ccw;
 629
 630         /* Clear any idals used for the request. */
 631         ccw = cqr->cpaddr;
 632         do {
 633                 clear_normalized_cda(ccw);
 634         } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
 635 #endif
 636         kfree(cqr->cpaddr);
 637         kfree(cqr->data);
 638         kfree(cqr);
 639         dasd_put_device(device);
 640 }
 641
 642 void
 643 dasd_sfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
 644 {
 645         unsigned long flags;
 646
 647         spin_lock_irqsave(&device->mem_lock, flags);
 648         dasd_free_chunk(&device->ccw_chunks, cqr);
 649         spin_unlock_irqrestore(&device->mem_lock, flags);
 650         dasd_put_device(device);
 651 }
 652
 653 /*
 654  * Check discipline magic in cqr.
 655  */
 656 static inline int
 657 dasd_check_cqr(struct dasd_ccw_req *cqr)
 658 {
 659         struct dasd_device *device;
 660
 661         if (cqr == NULL)
 662                 return -EINVAL;
 663         device = cqr->device;
 664         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
 665                 DEV_MESSAGE(KERN_WARNING, device,
 666                             " dasd_ccw_req 0x%08x magic doesn't match"
 667                             " discipline 0x%08x",
 668                             cqr->magic,
 669                             *(unsigned int *) device->discipline->name);
 670                 return -EINVAL;
 671         }
 672         return 0;
 673 }
 674
 675 /*
 676  * Terminate the current i/o and set the request to clear_pending.
 677  * Timer keeps device runnig.
 678  * ccw_device_clear can fail if the i/o subsystem
 679  * is in a bad mood.
 680  */
 681 int
 682 dasd_term_IO(struct dasd_ccw_req * cqr)
 683 {
 684         struct dasd_device *device;
 685         int retries, rc;
 686
 687         /* Check the cqr */
 688         rc = dasd_check_cqr(cqr);
 689         if (rc)
 690                 return rc;
 691         retries = 0;
 692         device = (struct dasd_device *) cqr->device;
 693         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
 694                 rc = ccw_device_clear(device->cdev, (long) cqr);
 695                 switch (rc) {
 696                 case 0: /* termination successful */
 697                         cqr->retries--;
 698                         cqr->status = DASD_CQR_CLEAR;
 699                         cqr->stopclk = get_clock();
 700                         DBF_DEV_EVENT(DBF_DEBUG, device,
 701                                       "terminate cqr %p successful",
 702                                       cqr);
 703                         break;
 704                 case -ENODEV:
 705                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 706                                       "device gone, retry");
 707                         break;
 708                 case -EIO:
 709                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 710                                       "I/O error, retry");
 711                         break;
 712                 case -EINVAL:
 713                 case -EBUSY:
 714                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 715                                       "device busy, retry later");
 716                         break;
 717                 default:
 718                         DEV_MESSAGE(KERN_ERR, device,
 719                                     "line %d unknown RC=%d, please "
 720                                     "report to linux390@de.ibm.com",
 721                                     __LINE__, rc);
 722                         BUG();
 723                         break;
 724                 }
 725                 retries++;
 726         }
 727         dasd_schedule_bh(device);
 728         return rc;
 729 }
 730
 731 /*
 732  * Start the i/o. This start_IO can fail if the channel is really busy.
 733  * In that case set up a timer to start the request later.
 734  */
 735 int
 736 dasd_start_IO(struct dasd_ccw_req * cqr)
 737 {
 738         struct dasd_device *device;
 739         int rc;
 740
 741         /* Check the cqr */
 742         rc = dasd_check_cqr(cqr);
 743         if (rc)
 744                 return rc;
 745         device = (struct dasd_device *) cqr->device;
 746         if (cqr->retries < 0) {
 747                 DEV_MESSAGE(KERN_DEBUG, device,
 748                             "start_IO: request %p (%02x/%i) - no retry left.",
 749                             cqr, cqr->status, cqr->retries);
 750                 cqr->status = DASD_CQR_FAILED;
 751                 return -EIO;
 752         }
 753         cqr->startclk = get_clock();
 754         cqr->starttime = jiffies;
 755         cqr->retries--;
 756         rc = ccw_device_start(device->cdev, cqr->cpaddr, (long) cqr,
 757                               cqr->lpm, 0);
 758         switch (rc) {
 759         case 0:
 760                 cqr->status = DASD_CQR_IN_IO;
 761                 DBF_DEV_EVENT(DBF_DEBUG, device,
 762                               "start_IO: request %p started successful",
 763                               cqr);
 764                 break;
 765         case -EBUSY:
 766                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 767                               "start_IO: device busy, retry later");
 768                 break;
 769         case -ETIMEDOUT:
 770                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 771                               "start_IO: request timeout, retry later");
 772                 break;
 773         case -EACCES:
 774                 /* -EACCES indicates that the request used only a
 775                  * subset of the available pathes and all these
 776                  * pathes are gone.
 777                  * Do a retry with all available pathes.
 778                  */
 779                 cqr->lpm = LPM_ANYPATH;
 780                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 781                               "start_IO: selected pathes gone,"
 782                               " retry on all pathes");
 783                 break;
 784         case -ENODEV:
 785         case -EIO:
 786                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 787                               "start_IO: device gone, retry");
 788                 break;
 789         default:
 790                 DEV_MESSAGE(KERN_ERR, device,
 791                             "line %d unknown RC=%d, please report"
 792                             " to linux390@de.ibm.com", __LINE__, rc);
 793                 BUG();
 794                 break;
 795         }
 796         return rc;
 797 }
 798
 799 /*
 800  * Timeout function for dasd devices. This is used for different purposes
 801  *  1) missing interrupt handler for normal operation
 802  *  2) delayed start of request where start_IO failed with -EBUSY
 803  *  3) timeout for missing state change interrupts
 804  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
 805  * DASD_CQR_QUEUED for 2) and 3).
 806  */
 807 static void
 808 dasd_timeout_device(unsigned long ptr)
 809 {
 810         unsigned long flags;
 811         struct dasd_device *device;
 812
 813         device = (struct dasd_device *) ptr;
 814         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
 815         /* re-activate request queue */
 816         device->stopped &= ~DASD_STOPPED_PENDING;
 817         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
 818         dasd_schedule_bh(device);
 819 }
 820
 821 /*
 822  * Setup timeout for a device in jiffies.
 823  */
 824 void
 825 dasd_set_timer(struct dasd_device *device, int expires)
 826 {
 827         if (expires == 0) {
 828                 if (timer_pending(&device->timer))
 829                         del_timer(&device->timer);
 830                 return;
 831         }
 832         if (timer_pending(&device->timer)) {
 833                 if (mod_timer(&device->timer, jiffies + expires))
 834                         return;
 835         }
 836         device->timer.function = dasd_timeout_device;
 837         device->timer.data = (unsigned long) device;
 838         device->timer.expires = jiffies + expires;
 839         add_timer(&device->timer);
 840 }
 841
 842 /*
 843  * Clear timeout for a device.
 844  */
 845 void
 846 dasd_clear_timer(struct dasd_device *device)
 847 {
 848         if (timer_pending(&device->timer))
 849                 del_timer(&device->timer);
 850 }
 851
 852 static void
 853 dasd_handle_killed_request(struct ccw_device *cdev, unsigned long intparm)
 854 {
 855         struct dasd_ccw_req *cqr;
 856         struct dasd_device *device;
 857
 858         cqr = (struct dasd_ccw_req *) intparm;
 859         if (cqr->status != DASD_CQR_IN_IO) {
 860                 MESSAGE(KERN_DEBUG,
 861                         "invalid status in handle_killed_request: "
 862                         "bus_id %s, status %02x",
 863                         cdev->dev.bus_id, cqr->status);
 864                 return;
 865         }
 866
 867         device = (struct dasd_device *) cqr->device;
 868         if (device == NULL ||
 869             device != dasd_device_from_cdev(cdev) ||
 870             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
 871                 MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
 872                         cdev->dev.bus_id);
 873                 return;
 874         }
 875
 876         /* Schedule request to be retried. */
 877         cqr->status = DASD_CQR_QUEUED;
 878
 879         dasd_clear_timer(device);
 880         dasd_schedule_bh(device);
 881         dasd_put_device(device);
 882 }
 883
 884 static void
 885 dasd_handle_state_change_pending(struct dasd_device *device)
 886 {
 887         struct dasd_ccw_req *cqr;
 888         struct list_head *l, *n;
 889
 890         /* First of all start sense subsystem status request. */
 891         dasd_eer_snss(device);
 892
 893         device->stopped &= ~DASD_STOPPED_PENDING;
 894
 895         /* restart all 'running' IO on queue */
 896         list_for_each_safe(l, n, &device->ccw_queue) {
 897                 cqr = list_entry(l, struct dasd_ccw_req, list);
 898                 if (cqr->status == DASD_CQR_IN_IO) {
 899                         cqr->status = DASD_CQR_QUEUED;
 900                 }
 901         }
 902         dasd_clear_timer(device);
 903         dasd_schedule_bh(device);
 904 }
 905
 906 /*
 907  * Interrupt handler for "normal" ssch-io based dasd devices.
 908  */
 909 void
 910 dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
 911                  struct irb *irb)
 912 {
 913         struct dasd_ccw_req *cqr, *next;
 914         struct dasd_device *device;
 915         unsigned long long now;
 916         int expires;
 917         dasd_era_t era;
 918         char mask;
 919
 920         if (IS_ERR(irb)) {
 921                 switch (PTR_ERR(irb)) {
 922                 case -EIO:
 923                         dasd_handle_killed_request(cdev, intparm);
 924                         break;
 925                 case -ETIMEDOUT:
 926                         printk(KERN_WARNING"%s(%s): request timed out\n",
 927                                __FUNCTION__, cdev->dev.bus_id);
 928                         //FIXME - dasd uses own timeout interface...
 929                         break;
 930                 default:
 931                         printk(KERN_WARNING"%s(%s): unknown error %ld\n",
 932                                __FUNCTION__, cdev->dev.bus_id, PTR_ERR(irb));
 933                 }
 934                 return;
 935         }
 936
 937         now = get_clock();
 938
 939         DBF_EVENT(DBF_ERR, "Interrupt: bus_id %s CS/DS %04x ip %08x",
 940                   cdev->dev.bus_id, ((irb->scsw.cstat<<8)|irb->scsw.dstat),
 941                   (unsigned int) intparm);
 942
 943         /* first of all check for state change pending interrupt */
 944         mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP;
 945         if ((irb->scsw.dstat & mask) == mask) {
 946                 device = dasd_device_from_cdev(cdev);
 947                 if (!IS_ERR(device)) {
 948                         dasd_handle_state_change_pending(device);
 949                         dasd_put_device(device);
 950                 }
 951                 return;
 952         }
 953
 954         cqr = (struct dasd_ccw_req *) intparm;
 955
 956         /* check for unsolicited interrupts */
 957         if (cqr == NULL) {
 958                 MESSAGE(KERN_DEBUG,
 959                         "unsolicited interrupt received: bus_id %s",
 960                         cdev->dev.bus_id);
 961                 return;
 962         }
 963
 964         device = (struct dasd_device *) cqr->device;
 965         if (device == NULL ||
 966             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
 967                 MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
 968                         cdev->dev.bus_id);
 969                 return;
 970         }
 971
 972         /* Check for clear pending */
 973         if (cqr->status == DASD_CQR_CLEAR &&
 974             irb->scsw.fctl & SCSW_FCTL_CLEAR_FUNC) {
 975                 cqr->status = DASD_CQR_QUEUED;
 976                 dasd_clear_timer(device);
 977                 dasd_schedule_bh(device);
 978                 return;
 979         }
 980
 981         /* check status - the request might have been killed by dyn detach */
 982         if (cqr->status != DASD_CQR_IN_IO) {
 983                 MESSAGE(KERN_DEBUG,
 984                         "invalid status: bus_id %s, status %02x",
 985                         cdev->dev.bus_id, cqr->status);
 986                 return;
 987         }
 988         DBF_DEV_EVENT(DBF_DEBUG, device, "Int: CS/DS 0x%04x for cqr %p",
 989                       ((irb->scsw.cstat << 8) | irb->scsw.dstat), cqr);
 990
 991         /* Find out the appropriate era_action. */
 992         if (irb->scsw.fctl & SCSW_FCTL_HALT_FUNC)
 993                 era = dasd_era_fatal;
 994         else if (irb->scsw.dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
 995                  irb->scsw.cstat == 0 &&
 996                  !irb->esw.esw0.erw.cons)
 997                 era = dasd_era_none;
 998         else if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags))
 999                 era = dasd_era_fatal; /* don't recover this request */
1000         else if (irb->esw.esw0.erw.cons)
1001                 era = device->discipline->examine_error(cqr, irb);
1002         else
1003                 era = dasd_era_recover;
1004
1005         DBF_DEV_EVENT(DBF_DEBUG, device, "era_code %d", era);
1006         expires = 0;
1007         if (era == dasd_era_none) {
1008                 cqr->status = DASD_CQR_DONE;
1009                 cqr->stopclk = now;
1010                 /* Start first request on queue if possible -> fast_io. */
1011                 if (cqr->list.next != &device->ccw_queue) {
1012                         next = list_entry(cqr->list.next,
1013                                           struct dasd_ccw_req, list);
1014                         if ((next->status == DASD_CQR_QUEUED) &&
1015                             (!device->stopped)) {
1016                                 if (device->discipline->start_IO(next) == 0)
1017                                         expires = next->expires;
1018                                 else
1019                                         DEV_MESSAGE(KERN_DEBUG, device, "%s",
1020                                                     "Interrupt fastpath "
1021                                                     "failed!");
1022                         }
1023                 }
1024         } else {                /* error */
1025                 memcpy(&cqr->irb, irb, sizeof (struct irb));
1026 #ifdef ERP_DEBUG
1027                 /* dump sense data */
1028                 dasd_log_sense(cqr, irb);
1029 #endif
1030                 switch (era) {
1031                 case dasd_era_fatal:
1032                         cqr->status = DASD_CQR_FAILED;
1033                         cqr->stopclk = now;
1034                         break;
1035                 case dasd_era_recover:
1036                         cqr->status = DASD_CQR_ERROR;
1037                         break;
1038                 default:
1039                         BUG();
1040                 }
1041         }
1042         if (expires != 0)
1043                 dasd_set_timer(device, expires);
1044         else
1045                 dasd_clear_timer(device);
1046         dasd_schedule_bh(device);
1047 }
1048
1049 /*
1050  * posts the buffer_cache about a finalized request
1051  */
1052 static inline void
1053 dasd_end_request(struct request *req, int uptodate)
1054 {
1055         if (end_that_request_first(req, uptodate, req->hard_nr_sectors))
1056                 BUG();
1057         add_disk_randomness(req->rq_disk);
1058         end_that_request_last(req, uptodate);
1059 }
1060
1061 /*
1062  * Process finished error recovery ccw.
1063  */
1064 static inline void
1065 __dasd_process_erp(struct dasd_device *device, struct dasd_ccw_req *cqr)
1066 {
1067         dasd_erp_fn_t erp_fn;
1068
1069         if (cqr->status == DASD_CQR_DONE)
1070                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
1071         else
1072                 DEV_MESSAGE(KERN_ERR, device, "%s", "ERP unsuccessful");
1073         erp_fn = device->discipline->erp_postaction(cqr);
1074         erp_fn(cqr);
1075 }
1076
1077 /*
1078  * Process ccw request queue.
1079  */
1080 static inline void
1081 __dasd_process_ccw_queue(struct dasd_device * device,
1082                          struct list_head *final_queue)
1083 {
1084         struct list_head *l, *n;
1085         struct dasd_ccw_req *cqr;
1086         dasd_erp_fn_t erp_fn;
1087
1088 restart:
1089         /* Process request with final status. */
1090         list_for_each_safe(l, n, &device->ccw_queue) {
1091                 cqr = list_entry(l, struct dasd_ccw_req, list);
1092                 /* Stop list processing at the first non-final request. */
1093                 if (cqr->status != DASD_CQR_DONE &&
1094                     cqr->status != DASD_CQR_FAILED &&
1095                     cqr->status != DASD_CQR_ERROR)
1096                         break;
1097                 /*  Process requests with DASD_CQR_ERROR */
1098                 if (cqr->status == DASD_CQR_ERROR) {
1099                         if (cqr->irb.scsw.fctl & SCSW_FCTL_HALT_FUNC) {
1100                                 cqr->status = DASD_CQR_FAILED;
1101                                 cqr->stopclk = get_clock();
1102                         } else {
1103                                 if (cqr->irb.esw.esw0.erw.cons) {
1104                                         erp_fn = device->discipline->
1105                                                 erp_action(cqr);
1106                                         erp_fn(cqr);
1107                                 } else
1108                                         dasd_default_erp_action(cqr);
1109                         }
1110                         goto restart;
1111                 }
1112
1113                 /* First of all call extended error reporting. */
1114                 if (dasd_eer_enabled(device) &&
1115                     cqr->status == DASD_CQR_FAILED) {
1116                         dasd_eer_write(device, cqr, DASD_EER_FATALERROR);
1117
1118                         /* restart request  */
1119                         cqr->status = DASD_CQR_QUEUED;
1120                         cqr->retries = 255;
1121                         device->stopped |= DASD_STOPPED_QUIESCE;
1122                         goto restart;
1123                 }
1124
1125                 /* Process finished ERP request. */
1126                 if (cqr->refers) {
1127                         __dasd_process_erp(device, cqr);
1128                         goto restart;
1129                 }
1130
1131                 /* Rechain finished requests to final queue */
1132                 cqr->endclk = get_clock();
1133                 list_move_tail(&cqr->list, final_queue);
1134         }
1135 }
1136
1137 static void
1138 dasd_end_request_cb(struct dasd_ccw_req * cqr, void *data)
1139 {
1140         struct request *req;
1141         struct dasd_device *device;
1142         int status;
1143
1144         req = (struct request *) data;
1145         device = cqr->device;
1146         dasd_profile_end(device, cqr, req);
1147         status = cqr->device->discipline->free_cp(cqr,req);
1148         spin_lock_irq(&device->request_queue_lock);
1149         dasd_end_request(req, status);
1150         spin_unlock_irq(&device->request_queue_lock);
1151 }
1152
1153
1154 /*
1155  * Fetch requests from the block device queue.
1156  */
1157 static inline void
1158 __dasd_process_blk_queue(struct dasd_device * device)
1159 {
1160         request_queue_t *queue;
1161         struct request *req;
1162         struct dasd_ccw_req *cqr;
1163         int nr_queued;
1164
1165         queue = device->request_queue;
1166         /* No queue ? Then there is nothing to do. */
1167         if (queue == NULL)
1168                 return;
1169
1170         /*
1171          * We requeue request from the block device queue to the ccw
1172          * queue only in two states. In state DASD_STATE_READY the
1173          * partition detection is done and we need to requeue requests
1174          * for that. State DASD_STATE_ONLINE is normal block device
1175          * operation.
1176          */
1177         if (device->state != DASD_STATE_READY &&
1178             device->state != DASD_STATE_ONLINE)
1179                 return;
1180         nr_queued = 0;
1181         /* Now we try to fetch requests from the request queue */
1182         list_for_each_entry(cqr, &device->ccw_queue, list)
1183                 if (cqr->status == DASD_CQR_QUEUED)
1184                         nr_queued++;
1185         while (!blk_queue_plugged(queue) &&
1186                elv_next_request(queue) &&
1187                 nr_queued < DASD_CHANQ_MAX_SIZE) {
1188                 req = elv_next_request(queue);
1189
1190                 if (device->features & DASD_FEATURE_READONLY &&
1191                     rq_data_dir(req) == WRITE) {
1192                         DBF_DEV_EVENT(DBF_ERR, device,
1193                                       "Rejecting write request %p",
1194                                       req);
1195                         blkdev_dequeue_request(req);
1196                         dasd_end_request(req, 0);
1197                         continue;
1198                 }
1199                 if (device->stopped & DASD_STOPPED_DC_EIO) {
1200                         blkdev_dequeue_request(req);
1201                         dasd_end_request(req, 0);
1202                         continue;
1203                 }
1204                 cqr = device->discipline->build_cp(device, req);
1205                 if (IS_ERR(cqr)) {
1206                         if (PTR_ERR(cqr) == -ENOMEM)
1207                                 break;  /* terminate request queue loop */
1208                         DBF_DEV_EVENT(DBF_ERR, device,
1209                                       "CCW creation failed (rc=%ld) "
1210                                       "on request %p",
1211                                       PTR_ERR(cqr), req);
1212                         blkdev_dequeue_request(req);
1213                         dasd_end_request(req, 0);
1214                         continue;
1215                 }
1216                 cqr->callback = dasd_end_request_cb;
1217                 cqr->callback_data = (void *) req;
1218                 cqr->status = DASD_CQR_QUEUED;
1219                 blkdev_dequeue_request(req);
1220                 list_add_tail(&cqr->list, &device->ccw_queue);
1221                 dasd_profile_start(device, cqr, req);
1222                 nr_queued++;
1223         }
1224 }
1225
1226 /*
1227  * Take a look at the first request on the ccw queue and check
1228  * if it reached its expire time. If so, terminate the IO.
1229  */
1230 static inline void
1231 __dasd_check_expire(struct dasd_device * device)
1232 {
1233         struct dasd_ccw_req *cqr;
1234
1235         if (list_empty(&device->ccw_queue))
1236                 return;
1237         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1238         if (cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) {
1239                 if (time_after_eq(jiffies, cqr->expires + cqr->starttime)) {
1240                         if (device->discipline->term_IO(cqr) != 0)
1241                                 /* Hmpf, try again in 1/10 sec */
1242                                 dasd_set_timer(device, 10);
1243                 }
1244         }
1245 }
1246
1247 /*
1248  * Take a look at the first request on the ccw queue and check
1249  * if it needs to be started.
1250  */
1251 static inline void
1252 __dasd_start_head(struct dasd_device * device)
1253 {
1254         struct dasd_ccw_req *cqr;
1255         int rc;
1256
1257         if (list_empty(&device->ccw_queue))
1258                 return;
1259         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1260         /* check FAILFAST */
1261         if (device->stopped & ~DASD_STOPPED_PENDING &&
1262             test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
1263             (!dasd_eer_enabled(device))) {
1264                 cqr->status = DASD_CQR_FAILED;
1265                 dasd_schedule_bh(device);
1266         }
1267         if ((cqr->status == DASD_CQR_QUEUED) &&
1268             (!device->stopped)) {
1269                 /* try to start the first I/O that can be started */
1270                 rc = device->discipline->start_IO(cqr);
1271                 if (rc == 0)
1272                         dasd_set_timer(device, cqr->expires);
1273                 else if (rc == -EACCES) {
1274                         dasd_schedule_bh(device);
1275                 } else
1276                         /* Hmpf, try again in 1/2 sec */
1277                         dasd_set_timer(device, 50);
1278         }
1279 }
1280
1281 /*
1282  * Remove requests from the ccw queue.
1283  */
1284 static void
1285 dasd_flush_ccw_queue(struct dasd_device * device, int all)
1286 {
1287         struct list_head flush_queue;
1288         struct list_head *l, *n;
1289         struct dasd_ccw_req *cqr;
1290
1291         INIT_LIST_HEAD(&flush_queue);
1292         spin_lock_irq(get_ccwdev_lock(device->cdev));
1293         list_for_each_safe(l, n, &device->ccw_queue) {
1294                 cqr = list_entry(l, struct dasd_ccw_req, list);
1295                 /* Flush all request or only block device requests? */
1296                 if (all == 0 && cqr->callback == dasd_end_request_cb)
1297                         continue;
1298                 if (cqr->status == DASD_CQR_IN_IO)
1299                         device->discipline->term_IO(cqr);
1300                 if (cqr->status != DASD_CQR_DONE ||
1301                     cqr->status != DASD_CQR_FAILED) {
1302                         cqr->status = DASD_CQR_FAILED;
1303                         cqr->stopclk = get_clock();
1304                 }
1305                 /* Process finished ERP request. */
1306                 if (cqr->refers) {
1307                         __dasd_process_erp(device, cqr);
1308                         continue;
1309                 }
1310                 /* Rechain request on device request queue */
1311                 cqr->endclk = get_clock();
1312                 list_move_tail(&cqr->list, &flush_queue);
1313         }
1314         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1315         /* Now call the callback function of flushed requests */
1316         list_for_each_safe(l, n, &flush_queue) {
1317                 cqr = list_entry(l, struct dasd_ccw_req, list);
1318                 if (cqr->callback != NULL)
1319                         (cqr->callback)(cqr, cqr->callback_data);
1320         }
1321 }
1322
1323 /*
1324  * Acquire the device lock and process queues for the device.
1325  */
1326 static void
1327 dasd_tasklet(struct dasd_device * device)
1328 {
1329         struct list_head final_queue;
1330         struct list_head *l, *n;
1331         struct dasd_ccw_req *cqr;
1332
1333         atomic_set (&device->tasklet_scheduled, 0);
1334         INIT_LIST_HEAD(&final_queue);
1335         spin_lock_irq(get_ccwdev_lock(device->cdev));
1336         /* Check expire time of first request on the ccw queue. */
1337         __dasd_check_expire(device);
1338         /* Finish off requests on ccw queue */
1339         __dasd_process_ccw_queue(device, &final_queue);
1340         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1341         /* Now call the callback function of requests with final status */
1342         list_for_each_safe(l, n, &final_queue) {
1343                 cqr = list_entry(l, struct dasd_ccw_req, list);
1344                 list_del_init(&cqr->list);
1345                 if (cqr->callback != NULL)
1346                         (cqr->callback)(cqr, cqr->callback_data);
1347         }
1348         spin_lock_irq(&device->request_queue_lock);
1349         spin_lock(get_ccwdev_lock(device->cdev));
1350         /* Get new request from the block device request queue */
1351         __dasd_process_blk_queue(device);
1352         /* Now check if the head of the ccw queue needs to be started. */
1353         __dasd_start_head(device);
1354         spin_unlock(get_ccwdev_lock(device->cdev));
1355         spin_unlock_irq(&device->request_queue_lock);
1356         dasd_put_device(device);
1357 }
1358
1359 /*
1360  * Schedules a call to dasd_tasklet over the device tasklet.
1361  */
1362 void
1363 dasd_schedule_bh(struct dasd_device * device)
1364 {
1365         /* Protect against rescheduling. */
1366         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
1367                 return;
1368         dasd_get_device(device);
1369         tasklet_hi_schedule(&device->tasklet);
1370 }
1371
1372 /*
1373  * Queue a request to the head of the ccw_queue. Start the I/O if
1374  * possible.
1375  */
1376 void
1377 dasd_add_request_head(struct dasd_ccw_req *req)
1378 {
1379         struct dasd_device *device;
1380         unsigned long flags;
1381
1382         device = req->device;
1383         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1384         req->status = DASD_CQR_QUEUED;
1385         req->device = device;
1386         list_add(&req->list, &device->ccw_queue);
1387         /* let the bh start the request to keep them in order */
1388         dasd_schedule_bh(device);
1389         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1390 }
1391
1392 /*
1393  * Queue a request to the tail of the ccw_queue. Start the I/O if
1394  * possible.
1395  */
1396 void
1397 dasd_add_request_tail(struct dasd_ccw_req *req)
1398 {
1399         struct dasd_device *device;
1400         unsigned long flags;
1401
1402         device = req->device;
1403         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1404         req->status = DASD_CQR_QUEUED;
1405         req->device = device;
1406         list_add_tail(&req->list, &device->ccw_queue);
1407         /* let the bh start the request to keep them in order */
1408         dasd_schedule_bh(device);
1409         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1410 }
1411
1412 /*
1413  * Wakeup callback.
1414  */
1415 static void
1416 dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
1417 {
1418         wake_up((wait_queue_head_t *) data);
1419 }
1420
1421 static inline int
1422 _wait_for_wakeup(struct dasd_ccw_req *cqr)
1423 {
1424         struct dasd_device *device;
1425         int rc;
1426
1427         device = cqr->device;
1428         spin_lock_irq(get_ccwdev_lock(device->cdev));
1429         rc = ((cqr->status == DASD_CQR_DONE ||
1430                cqr->status == DASD_CQR_FAILED) &&
1431               list_empty(&cqr->list));
1432         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1433         return rc;
1434 }
1435
1436 /*
1437  * Attempts to start a special ccw queue and waits for its completion.
1438  */
1439 int
1440 dasd_sleep_on(struct dasd_ccw_req * cqr)
1441 {
1442         wait_queue_head_t wait_q;
1443         struct dasd_device *device;
1444         int rc;
1445
1446         device = cqr->device;
1447         spin_lock_irq(get_ccwdev_lock(device->cdev));
1448
1449         init_waitqueue_head (&wait_q);
1450         cqr->callback = dasd_wakeup_cb;
1451         cqr->callback_data = (void *) &wait_q;
1452         cqr->status = DASD_CQR_QUEUED;
1453         list_add_tail(&cqr->list, &device->ccw_queue);
1454
1455         /* let the bh start the request to keep them in order */
1456         dasd_schedule_bh(device);
1457
1458         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1459
1460         wait_event(wait_q, _wait_for_wakeup(cqr));
1461
1462         /* Request status is either done or failed. */
1463         rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1464         return rc;
1465 }
1466
1467 /*
1468  * Attempts to start a special ccw queue and wait interruptible
1469  * for its completion.
1470  */
1471 int
1472 dasd_sleep_on_interruptible(struct dasd_ccw_req * cqr)
1473 {
1474         wait_queue_head_t wait_q;
1475         struct dasd_device *device;
1476         int rc, finished;
1477
1478         device = cqr->device;
1479         spin_lock_irq(get_ccwdev_lock(device->cdev));
1480
1481         init_waitqueue_head (&wait_q);
1482         cqr->callback = dasd_wakeup_cb;
1483         cqr->callback_data = (void *) &wait_q;
1484         cqr->status = DASD_CQR_QUEUED;
1485         list_add_tail(&cqr->list, &device->ccw_queue);
1486
1487         /* let the bh start the request to keep them in order */
1488         dasd_schedule_bh(device);
1489         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1490
1491         finished = 0;
1492         while (!finished) {
1493                 rc = wait_event_interruptible(wait_q, _wait_for_wakeup(cqr));
1494                 if (rc != -ERESTARTSYS) {
1495                         /* Request is final (done or failed) */
1496                         rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO;
1497                         break;
1498                 }
1499                 spin_lock_irq(get_ccwdev_lock(device->cdev));
1500                 switch (cqr->status) {
1501                 case DASD_CQR_IN_IO:
1502                         /* terminate runnig cqr */
1503                         if (device->discipline->term_IO) {
1504                                 cqr->retries = -1;
1505                                 device->discipline->term_IO(cqr);
1506                                 /*nished =
1507                                  * wait (non-interruptible) for final status
1508                                  * because signal ist still pending
1509                                  */
1510                                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1511                                 wait_event(wait_q, _wait_for_wakeup(cqr));
1512                                 spin_lock_irq(get_ccwdev_lock(device->cdev));
1513                                 rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO;
1514                                 finished = 1;
1515                         }
1516                         break;
1517                 case DASD_CQR_QUEUED:
1518                         /* request  */
1519                         list_del_init(&cqr->list);
1520                         rc = -EIO;
1521                         finished = 1;
1522                         break;
1523                 default:
1524                         /* cqr with 'non-interruptable' status - just wait */
1525                         break;
1526                 }
1527                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1528         }
1529         return rc;
1530 }
1531
1532 /*
1533  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
1534  * for eckd devices) the currently running request has to be terminated
1535  * and be put back to status queued, before the special request is added
1536  * to the head of the queue. Then the special request is waited on normally.
1537  */
1538 static inline int
1539 _dasd_term_running_cqr(struct dasd_device *device)
1540 {
1541         struct dasd_ccw_req *cqr;
1542         int rc;
1543
1544         if (list_empty(&device->ccw_queue))
1545                 return 0;
1546         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1547         rc = device->discipline->term_IO(cqr);
1548         if (rc == 0) {
1549                 /* termination successful */
1550                 cqr->status = DASD_CQR_QUEUED;
1551                 cqr->startclk = cqr->stopclk = 0;
1552                 cqr->starttime = 0;
1553         }
1554         return rc;
1555 }
1556
1557 int
1558 dasd_sleep_on_immediatly(struct dasd_ccw_req * cqr)
1559 {
1560         wait_queue_head_t wait_q;
1561         struct dasd_device *device;
1562         int rc;
1563
1564         device = cqr->device;
1565         spin_lock_irq(get_ccwdev_lock(device->cdev));
1566         rc = _dasd_term_running_cqr(device);
1567         if (rc) {
1568                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1569                 return rc;
1570         }
1571
1572         init_waitqueue_head (&wait_q);
1573         cqr->callback = dasd_wakeup_cb;
1574         cqr->callback_data = (void *) &wait_q;
1575         cqr->status = DASD_CQR_QUEUED;
1576         list_add(&cqr->list, &device->ccw_queue);
1577
1578         /* let the bh start the request to keep them in order */
1579         dasd_schedule_bh(device);
1580
1581         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1582
1583         wait_event(wait_q, _wait_for_wakeup(cqr));
1584
1585         /* Request status is either done or failed. */
1586         rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1587         return rc;
1588 }
1589
1590 /*
1591  * Cancels a request that was started with dasd_sleep_on_req.
1592  * This is useful to timeout requests. The request will be
1593  * terminated if it is currently in i/o.
1594  * Returns 1 if the request has been terminated.
1595  */
1596 int
1597 dasd_cancel_req(struct dasd_ccw_req *cqr)
1598 {
1599         struct dasd_device *device = cqr->device;
1600         unsigned long flags;
1601         int rc;
1602
1603         rc = 0;
1604         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1605         switch (cqr->status) {
1606         case DASD_CQR_QUEUED:
1607                 /* request was not started - just set to failed */
1608                 cqr->status = DASD_CQR_FAILED;
1609                 break;
1610         case DASD_CQR_IN_IO:
1611                 /* request in IO - terminate IO and release again */
1612                 if (device->discipline->term_IO(cqr) != 0)
1613                         /* what to do if unable to terminate ??????
1614                            e.g. not _IN_IO */
1615                         cqr->status = DASD_CQR_FAILED;
1616                 cqr->stopclk = get_clock();
1617                 rc = 1;
1618                 break;
1619         case DASD_CQR_DONE:
1620         case DASD_CQR_FAILED:
1621                 /* already finished - do nothing */
1622                 break;
1623         default:
1624                 DEV_MESSAGE(KERN_ALERT, device,
1625                             "invalid status %02x in request",
1626                             cqr->status);
1627                 BUG();
1628
1629         }
1630         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1631         dasd_schedule_bh(device);
1632         return rc;
1633 }
1634
1635 /*
1636  * SECTION: Block device operations (request queue, partitions, open, release).
1637  */
1638
1639 /*
1640  * Dasd request queue function. Called from ll_rw_blk.c
1641  */
1642 static void
1643 do_dasd_request(request_queue_t * queue)
1644 {
1645         struct dasd_device *device;
1646
1647         device = (struct dasd_device *) queue->queuedata;
1648         spin_lock(get_ccwdev_lock(device->cdev));
1649         /* Get new request from the block device request queue */
1650         __dasd_process_blk_queue(device);
1651         /* Now check if the head of the ccw queue needs to be started. */
1652         __dasd_start_head(device);
1653         spin_unlock(get_ccwdev_lock(device->cdev));
1654 }
1655
1656 /*
1657  * Allocate and initialize request queue and default I/O scheduler.
1658  */
1659 static int
1660 dasd_alloc_queue(struct dasd_device * device)
1661 {
1662         int rc;
1663
1664         device->request_queue = blk_init_queue(do_dasd_request,
1665                                                &device->request_queue_lock);
1666         if (device->request_queue == NULL)
1667                 return -ENOMEM;
1668
1669         device->request_queue->queuedata = device;
1670
1671         elevator_exit(device->request_queue->elevator);
1672         rc = elevator_init(device->request_queue, "deadline");
1673         if (rc) {
1674                 blk_cleanup_queue(device->request_queue);
1675                 return rc;
1676         }
1677         return 0;
1678 }
1679
1680 /*
1681  * Allocate and initialize request queue.
1682  */
1683 static void
1684 dasd_setup_queue(struct dasd_device * device)
1685 {
1686         int max;
1687
1688         blk_queue_hardsect_size(device->request_queue, device->bp_block);
1689         max = device->discipline->max_blocks << device->s2b_shift;
1690         blk_queue_max_sectors(device->request_queue, max);
1691         blk_queue_max_phys_segments(device->request_queue, -1L);
1692         blk_queue_max_hw_segments(device->request_queue, -1L);
1693         blk_queue_max_segment_size(device->request_queue, -1L);
1694         blk_queue_segment_boundary(device->request_queue, -1L);
1695         blk_queue_ordered(device->request_queue, QUEUE_ORDERED_TAG, NULL);
1696 }
1697
1698 /*
1699  * Deactivate and free request queue.
1700  */
1701 static void
1702 dasd_free_queue(struct dasd_device * device)
1703 {
1704         if (device->request_queue) {
1705                 blk_cleanup_queue(device->request_queue);
1706                 device->request_queue = NULL;
1707         }
1708 }
1709
1710 /*
1711  * Flush request on the request queue.
1712  */
1713 static void
1714 dasd_flush_request_queue(struct dasd_device * device)
1715 {
1716         struct request *req;
1717
1718         if (!device->request_queue)
1719                 return;
1720
1721         spin_lock_irq(&device->request_queue_lock);
1722         while (!list_empty(&device->request_queue->queue_head)) {
1723                 req = elv_next_request(device->request_queue);
1724                 if (req == NULL)
1725                         break;
1726                 dasd_end_request(req, 0);
1727                 blkdev_dequeue_request(req);
1728         }
1729         spin_unlock_irq(&device->request_queue_lock);
1730 }
1731
1732 static int
1733 dasd_open(struct inode *inp, struct file *filp)
1734 {
1735         struct gendisk *disk = inp->i_bdev->bd_disk;
1736         struct dasd_device *device = disk->private_data;
1737         int rc;
1738
1739         atomic_inc(&device->open_count);
1740         if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1741                 rc = -ENODEV;
1742                 goto unlock;
1743         }
1744
1745         if (!try_module_get(device->discipline->owner)) {
1746                 rc = -EINVAL;
1747                 goto unlock;
1748         }
1749
1750         if (dasd_probeonly) {
1751                 DEV_MESSAGE(KERN_INFO, device, "%s",
1752                             "No access to device due to probeonly mode");
1753                 rc = -EPERM;
1754                 goto out;
1755         }
1756
1757         if (device->state <= DASD_STATE_BASIC) {
1758                 DBF_DEV_EVENT(DBF_ERR, device, " %s",
1759                               " Cannot open unrecognized device");
1760                 rc = -ENODEV;
1761                 goto out;
1762         }
1763
1764         return 0;
1765
1766 out:
1767         module_put(device->discipline->owner);
1768 unlock:
1769         atomic_dec(&device->open_count);
1770         return rc;
1771 }
1772
1773 static int
1774 dasd_release(struct inode *inp, struct file *filp)
1775 {
1776         struct gendisk *disk = inp->i_bdev->bd_disk;
1777         struct dasd_device *device = disk->private_data;
1778
1779         atomic_dec(&device->open_count);
1780         module_put(device->discipline->owner);
1781         return 0;
1782 }
1783
1784 /*
1785  * Return disk geometry.
1786  */
1787 static int
1788 dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
1789 {
1790         struct dasd_device *device;
1791
1792         device = bdev->bd_disk->private_data;
1793         if (!device)
1794                 return -ENODEV;
1795
1796         if (!device->discipline ||
1797             !device->discipline->fill_geometry)
1798                 return -EINVAL;
1799
1800         device->discipline->fill_geometry(device, geo);
1801         geo->start = get_start_sect(bdev) >> device->s2b_shift;
1802         return 0;
1803 }
1804
1805 struct block_device_operations
1806 dasd_device_operations = {
1807         .owner          = THIS_MODULE,
1808         .open           = dasd_open,
1809         .release        = dasd_release,
1810         .ioctl          = dasd_ioctl,
1811         .compat_ioctl   = dasd_compat_ioctl,
1812         .getgeo         = dasd_getgeo,
1813 };
1814
1815
1816 static void
1817 dasd_exit(void)
1818 {
1819 #ifdef CONFIG_PROC_FS
1820         dasd_proc_exit();
1821 #endif
1822         dasd_eer_exit();
1823         if (dasd_page_cache != NULL) {
1824                 kmem_cache_destroy(dasd_page_cache);
1825                 dasd_page_cache = NULL;
1826         }
1827         dasd_gendisk_exit();
1828         dasd_devmap_exit();
1829         devfs_remove("dasd");
1830         if (dasd_debug_area != NULL) {
1831                 debug_unregister(dasd_debug_area);
1832                 dasd_debug_area = NULL;
1833         }
1834 }
1835
1836 /*
1837  * SECTION: common functions for ccw_driver use
1838  */
1839
1840 /*
1841  * Initial attempt at a probe function. this can be simplified once
1842  * the other detection code is gone.
1843  */
1844 int
1845 dasd_generic_probe (struct ccw_device *cdev,
1846                     struct dasd_discipline *discipline)
1847 {
1848         int ret;
1849
1850         ret = dasd_add_sysfs_files(cdev);
1851         if (ret) {
1852                 printk(KERN_WARNING
1853                        "dasd_generic_probe: could not add sysfs entries "
1854                        "for %s\n", cdev->dev.bus_id);
1855         } else {
1856                 cdev->handler = &dasd_int_handler;
1857         }
1858
1859         return ret;
1860 }
1861
1862 /*
1863  * This will one day be called from a global not_oper handler.
1864  * It is also used by driver_unregister during module unload.
1865  */
1866 void
1867 dasd_generic_remove (struct ccw_device *cdev)
1868 {
1869         struct dasd_device *device;
1870
1871         cdev->handler = NULL;
1872
1873         dasd_remove_sysfs_files(cdev);
1874         device = dasd_device_from_cdev(cdev);
1875         if (IS_ERR(device))
1876                 return;
1877         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1878                 /* Already doing offline processing */
1879                 dasd_put_device(device);
1880                 return;
1881         }
1882         /*
1883          * This device is removed unconditionally. Set offline
1884          * flag to prevent dasd_open from opening it while it is
1885          * no quite down yet.
1886          */
1887         dasd_set_target_state(device, DASD_STATE_NEW);
1888         /* dasd_delete_device destroys the device reference. */
1889         dasd_delete_device(device);
1890 }
1891
1892 /*
1893  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
1894  * the device is detected for the first time and is supposed to be used
1895  * or the user has started activation through sysfs.
1896  */
1897 int
1898 dasd_generic_set_online (struct ccw_device *cdev,
1899                          struct dasd_discipline *base_discipline)
1900
1901 {
1902         struct dasd_discipline *discipline;
1903         struct dasd_device *device;
1904         int rc;
1905
1906         device = dasd_create_device(cdev);
1907         if (IS_ERR(device))
1908                 return PTR_ERR(device);
1909
1910         discipline = base_discipline;
1911         if (device->features & DASD_FEATURE_USEDIAG) {
1912                 if (!dasd_diag_discipline_pointer) {
1913                         printk (KERN_WARNING
1914                                 "dasd_generic couldn't online device %s "
1915                                 "- discipline DIAG not available\n",
1916                                 cdev->dev.bus_id);
1917                         dasd_delete_device(device);
1918                         return -ENODEV;
1919                 }
1920                 discipline = dasd_diag_discipline_pointer;
1921         }
1922         if (!try_module_get(base_discipline->owner)) {
1923                 dasd_delete_device(device);
1924                 return -EINVAL;
1925         }
1926         if (!try_module_get(discipline->owner)) {
1927                 module_put(base_discipline->owner);
1928                 dasd_delete_device(device);
1929                 return -EINVAL;
1930         }
1931         device->base_discipline = base_discipline;
1932         device->discipline = discipline;
1933
1934         rc = discipline->check_device(device);
1935         if (rc) {
1936                 printk (KERN_WARNING
1937                         "dasd_generic couldn't online device %s "
1938                         "with discipline %s rc=%i\n",
1939                         cdev->dev.bus_id, discipline->name, rc);
1940                 module_put(discipline->owner);
1941                 module_put(base_discipline->owner);
1942                 dasd_delete_device(device);
1943                 return rc;
1944         }
1945
1946         dasd_set_target_state(device, DASD_STATE_ONLINE);
1947         if (device->state <= DASD_STATE_KNOWN) {
1948                 printk (KERN_WARNING
1949                         "dasd_generic discipline not found for %s\n",
1950                         cdev->dev.bus_id);
1951                 rc = -ENODEV;
1952                 dasd_set_target_state(device, DASD_STATE_NEW);
1953                 dasd_delete_device(device);
1954         } else
1955                 pr_debug("dasd_generic device %s found\n",
1956                                 cdev->dev.bus_id);
1957
1958         /* FIXME: we have to wait for the root device but we don't want
1959          * to wait for each single device but for all at once. */
1960         wait_event(dasd_init_waitq, _wait_for_device(device));
1961
1962         dasd_put_device(device);
1963
1964         return rc;
1965 }
1966
1967 int
1968 dasd_generic_set_offline (struct ccw_device *cdev)
1969 {
1970         struct dasd_device *device;
1971         int max_count;
1972
1973         device = dasd_device_from_cdev(cdev);
1974         if (IS_ERR(device))
1975                 return PTR_ERR(device);
1976         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1977                 /* Already doing offline processing */
1978                 dasd_put_device(device);
1979                 return 0;
1980         }
1981         /*
1982          * We must make sure that this device is currently not in use.
1983          * The open_count is increased for every opener, that includes
1984          * the blkdev_get in dasd_scan_partitions. We are only interested
1985          * in the other openers.
1986          */
1987         max_count = device->bdev ? 0 : -1;
1988         if (atomic_read(&device->open_count) > max_count) {
1989                 printk (KERN_WARNING "Can't offline dasd device with open"
1990                         " count = %i.\n",
1991                         atomic_read(&device->open_count));
1992                 clear_bit(DASD_FLAG_OFFLINE, &device->flags);
1993                 dasd_put_device(device);
1994                 return -EBUSY;
1995         }
1996         dasd_set_target_state(device, DASD_STATE_NEW);
1997         /* dasd_delete_device destroys the device reference. */
1998         dasd_delete_device(device);
1999
2000         return 0;
2001 }
2002
2003 int
2004 dasd_generic_notify(struct ccw_device *cdev, int event)
2005 {
2006         struct dasd_device *device;
2007         struct dasd_ccw_req *cqr;
2008         unsigned long flags;
2009         int ret;
2010
2011         device = dasd_device_from_cdev(cdev);
2012         if (IS_ERR(device))
2013                 return 0;
2014         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
2015         ret = 0;
2016         switch (event) {
2017         case CIO_GONE:
2018         case CIO_NO_PATH:
2019                 /* First of all call extended error reporting. */
2020                 dasd_eer_write(device, NULL, DASD_EER_NOPATH);
2021
2022                 if (device->state < DASD_STATE_BASIC)
2023                         break;
2024                 /* Device is active. We want to keep it. */
2025                 if (test_bit(DASD_FLAG_DSC_ERROR, &device->flags)) {
2026                         list_for_each_entry(cqr, &device->ccw_queue, list)
2027                                 if (cqr->status == DASD_CQR_IN_IO)
2028                                         cqr->status = DASD_CQR_FAILED;
2029                         device->stopped |= DASD_STOPPED_DC_EIO;
2030                 } else {
2031                         list_for_each_entry(cqr, &device->ccw_queue, list)
2032                                 if (cqr->status == DASD_CQR_IN_IO) {
2033                                         cqr->status = DASD_CQR_QUEUED;
2034                                         cqr->retries++;
2035                                 }
2036                         device->stopped |= DASD_STOPPED_DC_WAIT;
2037                         dasd_set_timer(device, 0);
2038                 }
2039                 dasd_schedule_bh(device);
2040                 ret = 1;
2041                 break;
2042         case CIO_OPER:
2043                 /* FIXME: add a sanity check. */
2044                 device->stopped &= ~(DASD_STOPPED_DC_WAIT|DASD_STOPPED_DC_EIO);
2045                 dasd_schedule_bh(device);
2046                 ret = 1;
2047                 break;
2048         }
2049         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
2050         dasd_put_device(device);
2051         return ret;
2052 }
2053
2054 /*
2055  * Automatically online either all dasd devices (dasd_autodetect) or
2056  * all devices specified with dasd= parameters.
2057  */
2058 static int
2059 __dasd_auto_online(struct device *dev, void *data)
2060 {
2061         struct ccw_device *cdev;
2062
2063         cdev = to_ccwdev(dev);
2064         if (dasd_autodetect || dasd_busid_known(cdev->dev.bus_id) == 0)
2065                 ccw_device_set_online(cdev);
2066         return 0;
2067 }
2068
2069 void
2070 dasd_generic_auto_online (struct ccw_driver *dasd_discipline_driver)
2071 {
2072         struct device_driver *drv;
2073
2074         drv = get_driver(&dasd_discipline_driver->driver);
2075         driver_for_each_device(drv, NULL, NULL, __dasd_auto_online);
2076         put_driver(drv);
2077 }
2078
2079
2080 static int __init
2081 dasd_init(void)
2082 {
2083         int rc;
2084
2085         init_waitqueue_head(&dasd_init_waitq);
2086
2087         /* register 'common' DASD debug area, used for all DBF_XXX calls */
2088         dasd_debug_area = debug_register("dasd", 1, 2, 8 * sizeof (long));
2089         if (dasd_debug_area == NULL) {
2090                 rc = -ENOMEM;
2091                 goto failed;
2092         }
2093         debug_register_view(dasd_debug_area, &debug_sprintf_view);
2094         debug_set_level(dasd_debug_area, DBF_EMERG);
2095
2096         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
2097
2098         dasd_diag_discipline_pointer = NULL;
2099
2100         rc = devfs_mk_dir("dasd");
2101         if (rc)
2102                 goto failed;
2103         rc = dasd_devmap_init();
2104         if (rc)
2105                 goto failed;
2106         rc = dasd_gendisk_init();
2107         if (rc)
2108                 goto failed;
2109         rc = dasd_parse();
2110         if (rc)
2111                 goto failed;
2112         rc = dasd_eer_init();
2113         if (rc)
2114                 goto failed;
2115 #ifdef CONFIG_PROC_FS
2116         rc = dasd_proc_init();
2117         if (rc)
2118                 goto failed;
2119 #endif
2120
2121         return 0;
2122 failed:
2123         MESSAGE(KERN_INFO, "%s", "initialization not performed due to errors");
2124         dasd_exit();
2125         return rc;
2126 }
2127
2128 module_init(dasd_init);
2129 module_exit(dasd_exit);
2130
2131 EXPORT_SYMBOL(dasd_debug_area);
2132 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
2133
2134 EXPORT_SYMBOL(dasd_add_request_head);
2135 EXPORT_SYMBOL(dasd_add_request_tail);
2136 EXPORT_SYMBOL(dasd_cancel_req);
2137 EXPORT_SYMBOL(dasd_clear_timer);
2138 EXPORT_SYMBOL(dasd_enable_device);
2139 EXPORT_SYMBOL(dasd_int_handler);
2140 EXPORT_SYMBOL(dasd_kfree_request);
2141 EXPORT_SYMBOL(dasd_kick_device);
2142 EXPORT_SYMBOL(dasd_kmalloc_request);
2143 EXPORT_SYMBOL(dasd_schedule_bh);
2144 EXPORT_SYMBOL(dasd_set_target_state);
2145 EXPORT_SYMBOL(dasd_set_timer);
2146 EXPORT_SYMBOL(dasd_sfree_request);
2147 EXPORT_SYMBOL(dasd_sleep_on);
2148 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2149 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2150 EXPORT_SYMBOL(dasd_smalloc_request);
2151 EXPORT_SYMBOL(dasd_start_IO);
2152 EXPORT_SYMBOL(dasd_term_IO);
2153
2154 EXPORT_SYMBOL_GPL(dasd_generic_probe);
2155 EXPORT_SYMBOL_GPL(dasd_generic_remove);
2156 EXPORT_SYMBOL_GPL(dasd_generic_notify);
2157 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
2158 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
2159 EXPORT_SYMBOL_GPL(dasd_generic_auto_online);
2160
2161 /*
2162  * Overrides for Emacs so that we follow Linus's tabbing style.
2163  * Emacs will notice this stuff at the end of the file and automatically
2164  * adjust the settings for this buffer only.  This must remain at the end
2165  * of the file.
2166  * ---------------------------------------------------------------------------
2167  * Local variables:
2168  * c-indent-level: 4
2169  * c-brace-imaginary-offset: 0
2170  * c-brace-offset: -4
2171  * c-argdecl-indent: 4
2172  * c-label-offset: -4
2173  * c-continued-statement-offset: 4
2174  * c-continued-brace-offset: 0
2175  * indent-tabs-mode: 1
2176  * tab-width: 8
2177  * End:
2178  */