drivers/s390/block/dasd.c

   1 /*
   2  * File...........: linux/drivers/s390/block/dasd.c
   3  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
   4  *                  Horst Hummel <Horst.Hummel@de.ibm.com>
   5  *                  Carsten Otte <Cotte@de.ibm.com>
   6  *                  Martin Schwidefsky <schwidefsky@de.ibm.com>
   7  * Bugreports.to..: <Linux390@de.ibm.com>
   8  * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999-2001
   9  *
  10  * $Revision: 1.158 $
  11  */
  12
  13 #include <linux/config.h>
  14 #include <linux/kmod.h>
  15 #include <linux/init.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/ctype.h>
  18 #include <linux/major.h>
  19 #include <linux/slab.h>
  20 #include <linux/buffer_head.h>
  21
  22 #include <asm/ccwdev.h>
  23 #include <asm/ebcdic.h>
  24 #include <asm/idals.h>
  25 #include <asm/todclk.h>
  26
  27 /* This is ugly... */
  28 #define PRINTK_HEADER "dasd:"
  29
  30 #include "dasd_int.h"
  31 /*
  32  * SECTION: Constant definitions to be used within this file
  33  */
  34 #define DASD_CHANQ_MAX_SIZE 4
  35
  36 /*
  37  * SECTION: exported variables of dasd.c
  38  */
  39 debug_info_t *dasd_debug_area;
  40 struct dasd_discipline *dasd_diag_discipline_pointer;
  41
  42 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
  43 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
  44                    " Copyright 2000 IBM Corporation");
  45 MODULE_SUPPORTED_DEVICE("dasd");
  46 MODULE_PARM(dasd, "1-" __MODULE_STRING(256) "s");
  47 MODULE_LICENSE("GPL");
  48
  49 /*
  50  * SECTION: prototypes for static functions of dasd.c
  51  */
  52 static int  dasd_alloc_queue(struct dasd_device * device);
  53 static void dasd_setup_queue(struct dasd_device * device);
  54 static void dasd_free_queue(struct dasd_device * device);
  55 static void dasd_flush_request_queue(struct dasd_device *);
  56 static void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
  57 static void dasd_flush_ccw_queue(struct dasd_device *, int);
  58 static void dasd_tasklet(struct dasd_device *);
  59 static void do_kick_device(void *data);
  60
  61 /*
  62  * SECTION: Operations on the device structure.
  63  */
  64 static wait_queue_head_t dasd_init_waitq;
  65
  66 /*
  67  * Allocate memory for a new device structure.
  68  */
  69 struct dasd_device *
  70 dasd_alloc_device(void)
  71 {
  72         struct dasd_device *device;
  73
  74         device = kmalloc(sizeof (struct dasd_device), GFP_ATOMIC);
  75         if (device == NULL)
  76                 return ERR_PTR(-ENOMEM);
  77         memset(device, 0, sizeof (struct dasd_device));
  78         /* open_count = 0 means device online but not in use */
  79         atomic_set(&device->open_count, -1);
  80
  81         /* Get two pages for normal block device operations. */
  82         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
  83         if (device->ccw_mem == NULL) {
  84                 kfree(device);
  85                 return ERR_PTR(-ENOMEM);
  86         }
  87         /* Get one page for error recovery. */
  88         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
  89         if (device->erp_mem == NULL) {
  90                 free_pages((unsigned long) device->ccw_mem, 1);
  91                 kfree(device);
  92                 return ERR_PTR(-ENOMEM);
  93         }
  94
  95         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
  96         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
  97         spin_lock_init(&device->mem_lock);
  98         spin_lock_init(&device->request_queue_lock);
  99         atomic_set (&device->tasklet_scheduled, 0);
 100         tasklet_init(&device->tasklet,
 101                      (void (*)(unsigned long)) dasd_tasklet,
 102                      (unsigned long) device);
 103         INIT_LIST_HEAD(&device->ccw_queue);
 104         init_timer(&device->timer);
 105         INIT_WORK(&device->kick_work, do_kick_device, device);
 106         device->state = DASD_STATE_NEW;
 107         device->target = DASD_STATE_NEW;
 108
 109         return device;
 110 }
 111
 112 /*
 113  * Free memory of a device structure.
 114  */
 115 void
 116 dasd_free_device(struct dasd_device *device)
 117 {
 118         if (device->private)
 119                 kfree(device->private);
 120         free_page((unsigned long) device->erp_mem);
 121         free_pages((unsigned long) device->ccw_mem, 1);
 122         kfree(device);
 123 }
 124
 125 /*
 126  * Make a new device known to the system.
 127  */
 128 static inline int
 129 dasd_state_new_to_known(struct dasd_device *device)
 130 {
 131         int rc;
 132
 133         /*
 134          * As long as the device is not in state DASD_STATE_NEW we want to
 135          * keep the reference count > 0.
 136          */
 137         dasd_get_device(device);
 138
 139         rc = dasd_alloc_queue(device);
 140         if (rc) {
 141                 dasd_put_device(device);
 142                 return rc;
 143         }
 144
 145         device->state = DASD_STATE_KNOWN;
 146         return 0;
 147 }
 148
 149 /*
 150  * Let the system forget about a device.
 151  */
 152 static inline void
 153 dasd_state_known_to_new(struct dasd_device * device)
 154 {
 155         /* Forget the discipline information. */
 156         device->discipline = NULL;
 157         device->state = DASD_STATE_NEW;
 158
 159         dasd_free_queue(device);
 160
 161         /* Give up reference we took in dasd_state_new_to_known. */
 162         dasd_put_device(device);
 163 }
 164
 165 /*
 166  * Request the irq line for the device.
 167  */
 168 static inline int
 169 dasd_state_known_to_basic(struct dasd_device * device)
 170 {
 171         int rc;
 172
 173         /* Allocate and register gendisk structure. */
 174         rc = dasd_gendisk_alloc(device);
 175         if (rc)
 176                 return rc;
 177
 178         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 179         device->debug_area = debug_register(device->cdev->dev.bus_id, 0, 2,
 180                                             8 * sizeof (long));
 181         debug_register_view(device->debug_area, &debug_sprintf_view);
 182         debug_set_level(device->debug_area, DBF_EMERG);
 183         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 184
 185         device->state = DASD_STATE_BASIC;
 186         return 0;
 187 }
 188
 189 /*
 190  * Release the irq line for the device. Terminate any running i/o.
 191  */
 192 static inline void
 193 dasd_state_basic_to_known(struct dasd_device * device)
 194 {
 195         dasd_gendisk_free(device);
 196         dasd_flush_ccw_queue(device, 1);
 197         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
 198         if (device->debug_area != NULL) {
 199                 debug_unregister(device->debug_area);
 200                 device->debug_area = NULL;
 201         }
 202         device->state = DASD_STATE_KNOWN;
 203 }
 204
 205 /*
 206  * Do the initial analysis. The do_analysis function may return
 207  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 208  * until the discipline decides to continue the startup sequence
 209  * by calling the function dasd_change_state. The eckd disciplines
 210  * uses this to start a ccw that detects the format. The completion
 211  * interrupt for this detection ccw uses the kernel event daemon to
 212  * trigger the call to dasd_change_state. All this is done in the
 213  * discipline code, see dasd_eckd.c.
 214  * After the analysis ccw is done (do_analysis returned 0 or error)
 215  * the block device is setup. Either a fake disk is added to allow
 216  * formatting or a proper device request queue is created.
 217  */
 218 static inline int
 219 dasd_state_basic_to_ready(struct dasd_device * device)
 220 {
 221         int rc;
 222
 223         rc = 0;
 224         if (device->discipline->do_analysis != NULL)
 225                 rc = device->discipline->do_analysis(device);
 226         if (rc)
 227                 return rc;
 228         dasd_setup_queue(device);
 229         device->state = DASD_STATE_READY;
 230         if (dasd_scan_partitions(device) != 0)
 231                 device->state = DASD_STATE_BASIC;
 232         return 0;
 233 }
 234
 235 /*
 236  * Remove device from block device layer. Destroy dirty buffers.
 237  * Forget format information. Check if the target level is basic
 238  * and if it is create fake disk for formatting.
 239  */
 240 static inline void
 241 dasd_state_ready_to_basic(struct dasd_device * device)
 242 {
 243         dasd_flush_ccw_queue(device, 0);
 244         dasd_destroy_partitions(device);
 245         dasd_flush_request_queue(device);
 246         device->blocks = 0;
 247         device->bp_block = 0;
 248         device->s2b_shift = 0;
 249         device->state = DASD_STATE_BASIC;
 250 }
 251
 252 /*
 253  * Make the device online and schedule the bottom half to start
 254  * the requeueing of requests from the linux request queue to the
 255  * ccw queue.
 256  */
 257 static inline int
 258 dasd_state_ready_to_online(struct dasd_device * device)
 259 {
 260         device->state = DASD_STATE_ONLINE;
 261         dasd_schedule_bh(device);
 262         return 0;
 263 }
 264
 265 /*
 266  * Stop the requeueing of requests again.
 267  */
 268 static inline void
 269 dasd_state_online_to_ready(struct dasd_device * device)
 270 {
 271         device->state = DASD_STATE_READY;
 272 }
 273
 274 /*
 275  * Device startup state changes.
 276  */
 277 static inline int
 278 dasd_increase_state(struct dasd_device *device)
 279 {
 280         int rc;
 281
 282         rc = 0;
 283         if (device->state == DASD_STATE_NEW &&
 284             device->target >= DASD_STATE_KNOWN)
 285                 rc = dasd_state_new_to_known(device);
 286
 287         if (!rc &&
 288             device->state == DASD_STATE_KNOWN &&
 289             device->target >= DASD_STATE_BASIC)
 290                 rc = dasd_state_known_to_basic(device);
 291
 292         if (!rc &&
 293             device->state == DASD_STATE_BASIC &&
 294             device->target >= DASD_STATE_READY)
 295                 rc = dasd_state_basic_to_ready(device);
 296
 297         if (!rc &&
 298             device->state == DASD_STATE_READY &&
 299             device->target >= DASD_STATE_ONLINE)
 300                 rc = dasd_state_ready_to_online(device);
 301
 302         return rc;
 303 }
 304
 305 /*
 306  * Device shutdown state changes.
 307  */
 308 static inline int
 309 dasd_decrease_state(struct dasd_device *device)
 310 {
 311         if (device->state == DASD_STATE_ONLINE &&
 312             device->target <= DASD_STATE_READY)
 313                 dasd_state_online_to_ready(device);
 314
 315         if (device->state == DASD_STATE_READY &&
 316             device->target <= DASD_STATE_BASIC)
 317                 dasd_state_ready_to_basic(device);
 318
 319         if (device->state == DASD_STATE_BASIC &&
 320             device->target <= DASD_STATE_KNOWN)
 321                 dasd_state_basic_to_known(device);
 322
 323         if (device->state == DASD_STATE_KNOWN &&
 324             device->target <= DASD_STATE_NEW)
 325                 dasd_state_known_to_new(device);
 326
 327         return 0;
 328 }
 329
 330 /*
 331  * This is the main startup/shutdown routine.
 332  */
 333 static void
 334 dasd_change_state(struct dasd_device *device)
 335 {
 336         int rc;
 337
 338         if (device->state == device->target)
 339                 /* Already where we want to go today... */
 340                 return;
 341         if (device->state < device->target)
 342                 rc = dasd_increase_state(device);
 343         else
 344                 rc = dasd_decrease_state(device);
 345         if (rc && rc != -EAGAIN)
 346                 device->target = device->state;
 347
 348         if (device->state == device->target)
 349                 wake_up(&dasd_init_waitq);
 350 }
 351
 352 /*
 353  * Kick starter for devices that did not complete the startup/shutdown
 354  * procedure or were sleeping because of a pending state.
 355  * dasd_kick_device will schedule a call do do_kick_device to the kernel
 356  * event daemon.
 357  */
 358 static void
 359 do_kick_device(void *data)
 360 {
 361         struct dasd_device *device;
 362
 363         device = (struct dasd_device *) data;
 364         dasd_change_state(device);
 365         dasd_schedule_bh(device);
 366         dasd_put_device(device);
 367 }
 368
 369 void
 370 dasd_kick_device(struct dasd_device *device)
 371 {
 372         dasd_get_device(device);
 373         /* queue call to dasd_kick_device to the kernel event daemon. */
 374         schedule_work(&device->kick_work);
 375 }
 376
 377 /*
 378  * Set the target state for a device and starts the state change.
 379  */
 380 void
 381 dasd_set_target_state(struct dasd_device *device, int target)
 382 {
 383         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 384         if (dasd_probeonly && target > DASD_STATE_READY)
 385                 target = DASD_STATE_READY;
 386         if (device->target != target) {
 387                 if (device->state == target)
 388                         wake_up(&dasd_init_waitq);
 389                 device->target = target;
 390         }
 391         if (device->state != device->target)
 392                 dasd_change_state(device);
 393 }
 394
 395 /*
 396  * Enable devices with device numbers in [from..to].
 397  */
 398 static inline int
 399 _wait_for_device(struct dasd_device *device)
 400 {
 401         return (device->state == device->target);
 402 }
 403
 404 void
 405 dasd_enable_device(struct dasd_device *device)
 406 {
 407         dasd_set_target_state(device, DASD_STATE_ONLINE);
 408         if (device->state <= DASD_STATE_KNOWN)
 409                 /* No discipline for device found. */
 410                 dasd_set_target_state(device, DASD_STATE_NEW);
 411         /* Now wait for the devices to come up. */
 412         wait_event(dasd_init_waitq, _wait_for_device(device));
 413 }
 414
 415 /*
 416  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 417  */
 418 #ifdef CONFIG_DASD_PROFILE
 419
 420 struct dasd_profile_info_t dasd_global_profile;
 421 unsigned int dasd_profile_level = DASD_PROFILE_OFF;
 422
 423 /*
 424  * Increments counter in global and local profiling structures.
 425  */
 426 #define dasd_profile_counter(value, counter, device) \
 427 { \
 428         int index; \
 429         for (index = 0; index < 31 && value >> (2+index); index++); \
 430         dasd_global_profile.counter[index]++; \
 431         device->profile.counter[index]++; \
 432 }
 433
 434 /*
 435  * Add profiling information for cqr before execution.
 436  */
 437 static inline void
 438 dasd_profile_start(struct dasd_device *device, struct dasd_ccw_req * cqr,
 439                    struct request *req)
 440 {
 441         struct list_head *l;
 442         unsigned int counter;
 443
 444         if (dasd_profile_level != DASD_PROFILE_ON)
 445                 return;
 446
 447         /* count the length of the chanq for statistics */
 448         counter = 0;
 449         list_for_each(l, &device->ccw_queue)
 450                 if (++counter >= 31)
 451                         break;
 452         dasd_global_profile.dasd_io_nr_req[counter]++;
 453         device->profile.dasd_io_nr_req[counter]++;
 454 }
 455
 456 /*
 457  * Add profiling information for cqr after execution.
 458  */
 459 static inline void
 460 dasd_profile_end(struct dasd_device *device, struct dasd_ccw_req * cqr,
 461                  struct request *req)
 462 {
 463         long strtime, irqtime, endtime, tottime;        /* in microseconds */
 464         long tottimeps, sectors;
 465
 466         if (dasd_profile_level != DASD_PROFILE_ON)
 467                 return;
 468
 469         sectors = req->nr_sectors;
 470         if (!cqr->buildclk || !cqr->startclk ||
 471             !cqr->stopclk || !cqr->endclk ||
 472             !sectors)
 473                 return;
 474
 475         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 476         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 477         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 478         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 479         tottimeps = tottime / sectors;
 480
 481         if (!dasd_global_profile.dasd_io_reqs)
 482                 memset(&dasd_global_profile, 0,
 483                        sizeof (struct dasd_profile_info_t));
 484         dasd_global_profile.dasd_io_reqs++;
 485         dasd_global_profile.dasd_io_sects += sectors;
 486
 487         if (!device->profile.dasd_io_reqs)
 488                 memset(&device->profile, 0,
 489                        sizeof (struct dasd_profile_info_t));
 490         device->profile.dasd_io_reqs++;
 491         device->profile.dasd_io_sects += sectors;
 492
 493         dasd_profile_counter(sectors, dasd_io_secs, device);
 494         dasd_profile_counter(tottime, dasd_io_times, device);
 495         dasd_profile_counter(tottimeps, dasd_io_timps, device);
 496         dasd_profile_counter(strtime, dasd_io_time1, device);
 497         dasd_profile_counter(irqtime, dasd_io_time2, device);
 498         dasd_profile_counter(irqtime / sectors, dasd_io_time2ps, device);
 499         dasd_profile_counter(endtime, dasd_io_time3, device);
 500 }
 501 #else
 502 #define dasd_profile_start(device, cqr, req) do {} while (0)
 503 #define dasd_profile_end(device, cqr, req) do {} while (0)
 504 #endif                          /* CONFIG_DASD_PROFILE */
 505
 506 /*
 507  * Allocate memory for a channel program with 'cplength' channel
 508  * command words and 'datasize' additional space. There are two
 509  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
 510  * memory and 2) dasd_smalloc_request uses the static ccw memory
 511  * that gets allocated for each device.
 512  */
 513 struct dasd_ccw_req *
 514 dasd_kmalloc_request(char *magic, int cplength, int datasize,
 515                    struct dasd_device * device)
 516 {
 517         struct dasd_ccw_req *cqr;
 518
 519         /* Sanity checks */
 520         if ( magic == NULL || datasize > PAGE_SIZE ||
 521              (cplength*sizeof(struct ccw1)) > PAGE_SIZE)
 522                 BUG();
 523
 524         cqr = kmalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
 525         if (cqr == NULL)
 526                 return ERR_PTR(-ENOMEM);
 527         memset(cqr, 0, sizeof(struct dasd_ccw_req));
 528         cqr->cpaddr = NULL;
 529         if (cplength > 0) {
 530                 cqr->cpaddr = kmalloc(cplength*sizeof(struct ccw1),
 531                                       GFP_ATOMIC | GFP_DMA);
 532                 if (cqr->cpaddr == NULL) {
 533                         kfree(cqr);
 534                         return ERR_PTR(-ENOMEM);
 535                 }
 536                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
 537         }
 538         cqr->data = NULL;
 539         if (datasize > 0) {
 540                 cqr->data = kmalloc(datasize, GFP_ATOMIC | GFP_DMA);
 541                 if (cqr->data == NULL) {
 542                         if (cqr->cpaddr != NULL)
 543                                 kfree(cqr->cpaddr);
 544                         kfree(cqr);
 545                         return ERR_PTR(-ENOMEM);
 546                 }
 547                 memset(cqr->data, 0, datasize);
 548         }
 549         strncpy((char *) &cqr->magic, magic, 4);
 550         ASCEBC((char *) &cqr->magic, 4);
 551         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
 552         dasd_get_device(device);
 553         return cqr;
 554 }
 555
 556 struct dasd_ccw_req *
 557 dasd_smalloc_request(char *magic, int cplength, int datasize,
 558                    struct dasd_device * device)
 559 {
 560         unsigned long flags;
 561         struct dasd_ccw_req *cqr;
 562         char *data;
 563         int size;
 564
 565         /* Sanity checks */
 566         if ( magic == NULL || datasize > PAGE_SIZE ||
 567              (cplength*sizeof(struct ccw1)) > PAGE_SIZE)
 568                 BUG();
 569
 570         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
 571         if (cplength > 0)
 572                 size += cplength * sizeof(struct ccw1);
 573         if (datasize > 0)
 574                 size += datasize;
 575         spin_lock_irqsave(&device->mem_lock, flags);
 576         cqr = (struct dasd_ccw_req *)
 577                 dasd_alloc_chunk(&device->ccw_chunks, size);
 578         spin_unlock_irqrestore(&device->mem_lock, flags);
 579         if (cqr == NULL)
 580                 return ERR_PTR(-ENOMEM);
 581         memset(cqr, 0, sizeof(struct dasd_ccw_req));
 582         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
 583         cqr->cpaddr = NULL;
 584         if (cplength > 0) {
 585                 cqr->cpaddr = (struct ccw1 *) data;
 586                 data += cplength*sizeof(struct ccw1);
 587                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
 588         }
 589         cqr->data = NULL;
 590         if (datasize > 0) {
 591                 cqr->data = data;
 592                 memset(cqr->data, 0, datasize);
 593         }
 594         strncpy((char *) &cqr->magic, magic, 4);
 595         ASCEBC((char *) &cqr->magic, 4);
 596         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
 597         dasd_get_device(device);
 598         return cqr;
 599 }
 600
 601 /*
 602  * Free memory of a channel program. This function needs to free all the
 603  * idal lists that might have been created by dasd_set_cda and the
 604  * struct dasd_ccw_req itself.
 605  */
 606 void
 607 dasd_kfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
 608 {
 609 #ifdef CONFIG_ARCH_S390X
 610         struct ccw1 *ccw;
 611
 612         /* Clear any idals used for the request. */
 613         ccw = cqr->cpaddr;
 614         do {
 615                 clear_normalized_cda(ccw);
 616         } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
 617 #endif
 618         if (cqr->cpaddr != NULL)
 619                 kfree(cqr->cpaddr);
 620         if (cqr->data != NULL)
 621                 kfree(cqr->data);
 622         kfree(cqr);
 623         dasd_put_device(device);
 624 }
 625
 626 void
 627 dasd_sfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
 628 {
 629         unsigned long flags;
 630
 631         spin_lock_irqsave(&device->mem_lock, flags);
 632         dasd_free_chunk(&device->ccw_chunks, cqr);
 633         spin_unlock_irqrestore(&device->mem_lock, flags);
 634         dasd_put_device(device);
 635 }
 636
 637 /*
 638  * Check discipline magic in cqr.
 639  */
 640 static inline int
 641 dasd_check_cqr(struct dasd_ccw_req *cqr)
 642 {
 643         struct dasd_device *device;
 644
 645         if (cqr == NULL)
 646                 return -EINVAL;
 647         device = cqr->device;
 648         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
 649                 DEV_MESSAGE(KERN_WARNING, device,
 650                             " dasd_ccw_req 0x%08x magic doesn't match"
 651                             " discipline 0x%08x",
 652                             cqr->magic,
 653                             *(unsigned int *) device->discipline->name);
 654                 return -EINVAL;
 655         }
 656         return 0;
 657 }
 658
 659 /*
 660  * Terminate the current i/o and set the request to clear_pending.
 661  * Timer keeps device runnig.
 662  * ccw_device_clear can fail if the i/o subsystem
 663  * is in a bad mood.
 664  */
 665 int
 666 dasd_term_IO(struct dasd_ccw_req * cqr)
 667 {
 668         struct dasd_device *device;
 669         int retries, rc;
 670
 671         /* Check the cqr */
 672         rc = dasd_check_cqr(cqr);
 673         if (rc)
 674                 return rc;
 675         retries = 0;
 676         device = (struct dasd_device *) cqr->device;
 677         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
 678                 rc = ccw_device_clear(device->cdev, (long) cqr);
 679                 switch (rc) {
 680                 case 0: /* termination successful */
 681                         if (cqr->retries > 0) {
 682                                 cqr->retries--;
 683                                 cqr->status = DASD_CQR_CLEAR;
 684                         } else
 685                                 cqr->status = DASD_CQR_FAILED;
 686                         cqr->stopclk = get_clock();
 687                         DBF_DEV_EVENT(DBF_DEBUG, device,
 688                                       "terminate cqr %p successful",
 689                                       cqr);
 690                         break;
 691                 case -ENODEV:
 692                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 693                                       "device gone, retry");
 694                         break;
 695                 case -EIO:
 696                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 697                                       "I/O error, retry");
 698                         break;
 699                 case -EINVAL:
 700                 case -EBUSY:
 701                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 702                                       "device busy, retry later");
 703                         break;
 704                 default:
 705                         DEV_MESSAGE(KERN_ERR, device,
 706                                     "line %d unknown RC=%d, please "
 707                                     "report to linux390@de.ibm.com",
 708                                     __LINE__, rc);
 709                         BUG();
 710                         break;
 711                 }
 712                 retries++;
 713         }
 714         dasd_schedule_bh(device);
 715         return rc;
 716 }
 717
 718 /*
 719  * Start the i/o. This start_IO can fail if the channel is really busy.
 720  * In that case set up a timer to start the request later.
 721  */
 722 int
 723 dasd_start_IO(struct dasd_ccw_req * cqr)
 724 {
 725         struct dasd_device *device;
 726         int rc;
 727
 728         /* Check the cqr */
 729         rc = dasd_check_cqr(cqr);
 730         if (rc)
 731                 return rc;
 732         device = (struct dasd_device *) cqr->device;
 733         if (cqr->retries < 0) {
 734                 DEV_MESSAGE(KERN_DEBUG, device,
 735                             "start_IO: request %p (%02x/%i) - no retry left.",
 736                             cqr, cqr->status, cqr->retries);
 737                 cqr->status = DASD_CQR_FAILED;
 738                 return -EIO;
 739         }
 740         cqr->startclk = get_clock();
 741         cqr->starttime = jiffies;
 742         cqr->retries--;
 743         rc = ccw_device_start(device->cdev, cqr->cpaddr, (long) cqr,
 744                               cqr->lpm, 0);
 745         switch (rc) {
 746         case 0:
 747                 cqr->status = DASD_CQR_IN_IO;
 748                 DBF_DEV_EVENT(DBF_DEBUG, device,
 749                               "start_IO: request %p started successful",
 750                               cqr);
 751                 break;
 752         case -EBUSY:
 753                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 754                               "start_IO: device busy, retry later");
 755                 break;
 756         case -ETIMEDOUT:
 757                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 758                               "start_IO: request timeout, retry later");
 759                 break;
 760         case -EACCES:
 761                 /* -EACCES indicates that the request used only a
 762                  * subset of the available pathes and all these
 763                  * pathes are gone.
 764                  * Do a retry with all available pathes.
 765                  */
 766                 cqr->lpm = LPM_ANYPATH;
 767                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 768                               "start_IO: selected pathes gone,"
 769                               " retry on all pathes");
 770                 break;
 771         case -ENODEV:
 772         case -EIO:
 773                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 774                               "start_IO: device gone, retry");
 775                 break;
 776         default:
 777                 DEV_MESSAGE(KERN_ERR, device,
 778                             "line %d unknown RC=%d, please report"
 779                             " to linux390@de.ibm.com", __LINE__, rc);
 780                 BUG();
 781                 break;
 782         }
 783         return rc;
 784 }
 785
 786 /*
 787  * Timeout function for dasd devices. This is used for different purposes
 788  *  1) missing interrupt handler for normal operation
 789  *  2) delayed start of request where start_IO failed with -EBUSY
 790  *  3) timeout for missing state change interrupts
 791  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
 792  * DASD_CQR_QUEUED for 2) and 3).
 793  */
 794 static void
 795 dasd_timeout_device(unsigned long ptr)
 796 {
 797         unsigned long flags;
 798         struct dasd_device *device;
 799
 800         device = (struct dasd_device *) ptr;
 801         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
 802         /* re-activate request queue */
 803         device->stopped &= ~DASD_STOPPED_PENDING;
 804         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
 805         dasd_schedule_bh(device);
 806 }
 807
 808 /*
 809  * Setup timeout for a device in jiffies.
 810  */
 811 void
 812 dasd_set_timer(struct dasd_device *device, int expires)
 813 {
 814         if (expires == 0) {
 815                 if (timer_pending(&device->timer))
 816                         del_timer(&device->timer);
 817                 return;
 818         }
 819         if (timer_pending(&device->timer)) {
 820                 if (mod_timer(&device->timer, jiffies + expires))
 821                         return;
 822         }
 823         device->timer.function = dasd_timeout_device;
 824         device->timer.data = (unsigned long) device;
 825         device->timer.expires = jiffies + expires;
 826         add_timer(&device->timer);
 827 }
 828
 829 /*
 830  * Clear timeout for a device.
 831  */
 832 void
 833 dasd_clear_timer(struct dasd_device *device)
 834 {
 835         if (timer_pending(&device->timer))
 836                 del_timer(&device->timer);
 837 }
 838
 839 static void
 840 dasd_handle_killed_request(struct ccw_device *cdev, unsigned long intparm)
 841 {
 842         struct dasd_ccw_req *cqr;
 843         struct dasd_device *device;
 844
 845         cqr = (struct dasd_ccw_req *) intparm;
 846         if (cqr->status != DASD_CQR_IN_IO) {
 847                 MESSAGE(KERN_DEBUG,
 848                         "invalid status in handle_killed_request: "
 849                         "bus_id %s, status %02x",
 850                         cdev->dev.bus_id, cqr->status);
 851                 return;
 852         }
 853
 854         device = (struct dasd_device *) cqr->device;
 855         if (device == NULL ||
 856             device != dasd_device_from_cdev(cdev) ||
 857             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
 858                 MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
 859                         cdev->dev.bus_id);
 860                 return;
 861         }
 862
 863         /* Schedule request to be retried. */
 864         cqr->status = DASD_CQR_QUEUED;
 865
 866         dasd_clear_timer(device);
 867         dasd_schedule_bh(device);
 868         dasd_put_device(device);
 869 }
 870
 871 static void
 872 dasd_handle_state_change_pending(struct dasd_device *device)
 873 {
 874         struct dasd_ccw_req *cqr;
 875         struct list_head *l, *n;
 876
 877         device->stopped &= ~DASD_STOPPED_PENDING;
 878
 879         /* restart all 'running' IO on queue */
 880         list_for_each_safe(l, n, &device->ccw_queue) {
 881                 cqr = list_entry(l, struct dasd_ccw_req, list);
 882                 if (cqr->status == DASD_CQR_IN_IO) {
 883                         cqr->status = DASD_CQR_QUEUED;
 884                 }
 885         }
 886         dasd_clear_timer(device);
 887         dasd_schedule_bh(device);
 888 }
 889
 890 /*
 891  * Interrupt handler for "normal" ssch-io based dasd devices.
 892  */
 893 void
 894 dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
 895                  struct irb *irb)
 896 {
 897         struct dasd_ccw_req *cqr, *next;
 898         struct dasd_device *device;
 899         unsigned long long now;
 900         int expires;
 901         dasd_era_t era;
 902         char mask;
 903
 904         if (IS_ERR(irb)) {
 905                 switch (PTR_ERR(irb)) {
 906                 case -EIO:
 907                         dasd_handle_killed_request(cdev, intparm);
 908                         break;
 909                 case -ETIMEDOUT:
 910                         printk(KERN_WARNING"%s(%s): request timed out\n",
 911                                __FUNCTION__, cdev->dev.bus_id);
 912                         //FIXME - dasd uses own timeout interface...
 913                         break;
 914                 default:
 915                         printk(KERN_WARNING"%s(%s): unknown error %ld\n",
 916                                __FUNCTION__, cdev->dev.bus_id, PTR_ERR(irb));
 917                 }
 918                 return;
 919         }
 920
 921         now = get_clock();
 922
 923         DBF_EVENT(DBF_ERR, "Interrupt: bus_id %s CS/DS %04x ip %08x",
 924                   cdev->dev.bus_id, ((irb->scsw.cstat<<8)|irb->scsw.dstat),
 925                   (unsigned int) intparm);
 926
 927         /* first of all check for state change pending interrupt */
 928         mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP;
 929         if ((irb->scsw.dstat & mask) == mask) {
 930                 device = dasd_device_from_cdev(cdev);
 931                 if (!IS_ERR(device)) {
 932                         dasd_handle_state_change_pending(device);
 933                         dasd_put_device(device);
 934                 }
 935                 return;
 936         }
 937
 938         cqr = (struct dasd_ccw_req *) intparm;
 939
 940         /* check for unsolicited interrupts */
 941         if (cqr == NULL) {
 942                 MESSAGE(KERN_DEBUG,
 943                         "unsolicited interrupt received: bus_id %s",
 944                         cdev->dev.bus_id);
 945                 return;
 946         }
 947
 948         device = (struct dasd_device *) cqr->device;
 949         if (device == NULL ||
 950             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
 951                 MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
 952                         cdev->dev.bus_id);
 953                 return;
 954         }
 955
 956         /* Check for clear pending */
 957         if (cqr->status == DASD_CQR_CLEAR &&
 958             irb->scsw.fctl & SCSW_FCTL_CLEAR_FUNC) {
 959                 cqr->status = DASD_CQR_QUEUED;
 960                 dasd_clear_timer(device);
 961                 dasd_schedule_bh(device);
 962                 return;
 963         }
 964
 965         /* check status - the request might have been killed by dyn detach */
 966         if (cqr->status != DASD_CQR_IN_IO) {
 967                 MESSAGE(KERN_DEBUG,
 968                         "invalid status: bus_id %s, status %02x",
 969                         cdev->dev.bus_id, cqr->status);
 970                 return;
 971         }
 972         DBF_DEV_EVENT(DBF_DEBUG, device, "Int: CS/DS 0x%04x for cqr %p",
 973                       ((irb->scsw.cstat << 8) | irb->scsw.dstat), cqr);
 974
 975         /* Find out the appropriate era_action. */
 976         if (irb->scsw.fctl & SCSW_FCTL_HALT_FUNC)
 977                 era = dasd_era_fatal;
 978         else if (irb->scsw.dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
 979                  irb->scsw.cstat == 0 &&
 980                  !irb->esw.esw0.erw.cons)
 981                 era = dasd_era_none;
 982         else if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags))
 983                 era = dasd_era_fatal; /* don't recover this request */
 984         else if (irb->esw.esw0.erw.cons)
 985                 era = device->discipline->examine_error(cqr, irb);
 986         else
 987                 era = dasd_era_recover;
 988
 989         DBF_DEV_EVENT(DBF_DEBUG, device, "era_code %d", era);
 990         expires = 0;
 991         if (era == dasd_era_none) {
 992                 cqr->status = DASD_CQR_DONE;
 993                 cqr->stopclk = now;
 994                 /* Start first request on queue if possible -> fast_io. */
 995                 if (cqr->list.next != &device->ccw_queue) {
 996                         next = list_entry(cqr->list.next,
 997                                           struct dasd_ccw_req, list);
 998                         if ((next->status == DASD_CQR_QUEUED) &&
 999                             (!device->stopped)) {
1000                                 if (device->discipline->start_IO(next) == 0)
1001                                         expires = next->expires;
1002                                 else
1003                                         DEV_MESSAGE(KERN_DEBUG, device, "%s",
1004                                                     "Interrupt fastpath "
1005                                                     "failed!");
1006                         }
1007                 }
1008         } else {                /* error */
1009                 memcpy(&cqr->irb, irb, sizeof (struct irb));
1010 #ifdef ERP_DEBUG
1011                 /* dump sense data */
1012                 dasd_log_sense(cqr, irb);
1013 #endif
1014                 switch (era) {
1015                 case dasd_era_fatal:
1016                         cqr->status = DASD_CQR_FAILED;
1017                         cqr->stopclk = now;
1018                         break;
1019                 case dasd_era_recover:
1020                         cqr->status = DASD_CQR_ERROR;
1021                         break;
1022                 default:
1023                         BUG();
1024                 }
1025         }
1026         if (expires != 0)
1027                 dasd_set_timer(device, expires);
1028         else
1029                 dasd_clear_timer(device);
1030         dasd_schedule_bh(device);
1031 }
1032
1033 /*
1034  * posts the buffer_cache about a finalized request
1035  */
1036 static inline void
1037 dasd_end_request(struct request *req, int uptodate)
1038 {
1039         if (end_that_request_first(req, uptodate, req->hard_nr_sectors))
1040                 BUG();
1041         add_disk_randomness(req->rq_disk);
1042         end_that_request_last(req);
1043 }
1044
1045 /*
1046  * Process finished error recovery ccw.
1047  */
1048 static inline void
1049 __dasd_process_erp(struct dasd_device *device, struct dasd_ccw_req *cqr)
1050 {
1051         dasd_erp_fn_t erp_fn;
1052
1053         if (cqr->status == DASD_CQR_DONE)
1054                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
1055         else
1056                 DEV_MESSAGE(KERN_ERR, device, "%s", "ERP unsuccessful");
1057         erp_fn = device->discipline->erp_postaction(cqr);
1058         erp_fn(cqr);
1059 }
1060
1061 /*
1062  * Process ccw request queue.
1063  */
1064 static inline void
1065 __dasd_process_ccw_queue(struct dasd_device * device,
1066                          struct list_head *final_queue)
1067 {
1068         struct list_head *l, *n;
1069         struct dasd_ccw_req *cqr;
1070         dasd_erp_fn_t erp_fn;
1071
1072 restart:
1073         /* Process request with final status. */
1074         list_for_each_safe(l, n, &device->ccw_queue) {
1075                 cqr = list_entry(l, struct dasd_ccw_req, list);
1076                 /* Stop list processing at the first non-final request. */
1077                 if (cqr->status != DASD_CQR_DONE &&
1078                     cqr->status != DASD_CQR_FAILED &&
1079                     cqr->status != DASD_CQR_ERROR)
1080                         break;
1081                 /*  Process requests with DASD_CQR_ERROR */
1082                 if (cqr->status == DASD_CQR_ERROR) {
1083                         if (cqr->irb.scsw.fctl & SCSW_FCTL_HALT_FUNC) {
1084                                 cqr->status = DASD_CQR_FAILED;
1085                                 cqr->stopclk = get_clock();
1086                         } else {
1087                                 if (cqr->irb.esw.esw0.erw.cons) {
1088                                         erp_fn = device->discipline->
1089                                                 erp_action(cqr);
1090                                         erp_fn(cqr);
1091                                 } else
1092                                         dasd_default_erp_action(cqr);
1093                         }
1094                         goto restart;
1095                 }
1096                 /* Process finished ERP request. */
1097                 if (cqr->refers) {
1098                         __dasd_process_erp(device, cqr);
1099                         goto restart;
1100                 }
1101
1102                 /* Rechain finished requests to final queue */
1103                 cqr->endclk = get_clock();
1104                 list_move_tail(&cqr->list, final_queue);
1105         }
1106 }
1107
1108 static void
1109 dasd_end_request_cb(struct dasd_ccw_req * cqr, void *data)
1110 {
1111         struct request *req;
1112         struct dasd_device *device;
1113         int status;
1114
1115         req = (struct request *) data;
1116         device = cqr->device;
1117         dasd_profile_end(device, cqr, req);
1118         status = cqr->device->discipline->free_cp(cqr,req);
1119         spin_lock_irq(&device->request_queue_lock);
1120         dasd_end_request(req, status);
1121         spin_unlock_irq(&device->request_queue_lock);
1122 }
1123
1124
1125 /*
1126  * Fetch requests from the block device queue.
1127  */
1128 static inline void
1129 __dasd_process_blk_queue(struct dasd_device * device)
1130 {
1131         request_queue_t *queue;
1132         struct request *req;
1133         struct dasd_ccw_req *cqr;
1134         int nr_queued;
1135
1136         queue = device->request_queue;
1137         /* No queue ? Then there is nothing to do. */
1138         if (queue == NULL)
1139                 return;
1140
1141         /*
1142          * We requeue request from the block device queue to the ccw
1143          * queue only in two states. In state DASD_STATE_READY the
1144          * partition detection is done and we need to requeue requests
1145          * for that. State DASD_STATE_ONLINE is normal block device
1146          * operation.
1147          */
1148         if (device->state != DASD_STATE_READY &&
1149             device->state != DASD_STATE_ONLINE)
1150                 return;
1151         nr_queued = 0;
1152         /* Now we try to fetch requests from the request queue */
1153         list_for_each_entry(cqr, &device->ccw_queue, list)
1154                 if (cqr->status == DASD_CQR_QUEUED)
1155                         nr_queued++;
1156         while (!blk_queue_plugged(queue) &&
1157                elv_next_request(queue) &&
1158                 nr_queued < DASD_CHANQ_MAX_SIZE) {
1159                 req = elv_next_request(queue);
1160                 if (test_bit(DASD_FLAG_RO, &device->flags) &&
1161                     rq_data_dir(req) == WRITE) {
1162                         DBF_DEV_EVENT(DBF_ERR, device,
1163                                       "Rejecting write request %p",
1164                                       req);
1165                         blkdev_dequeue_request(req);
1166                         dasd_end_request(req, 0);
1167                         continue;
1168                 }
1169                 if (device->stopped & DASD_STOPPED_DC_EIO) {
1170                         blkdev_dequeue_request(req);
1171                         dasd_end_request(req, 0);
1172                         continue;
1173                 }
1174                 cqr = device->discipline->build_cp(device, req);
1175                 if (IS_ERR(cqr)) {
1176                         if (PTR_ERR(cqr) == -ENOMEM)
1177                                 break;  /* terminate request queue loop */
1178                         DBF_DEV_EVENT(DBF_ERR, device,
1179                                       "CCW creation failed (rc=%ld) "
1180                                       "on request %p",
1181                                       PTR_ERR(cqr), req);
1182                         blkdev_dequeue_request(req);
1183                         dasd_end_request(req, 0);
1184                         continue;
1185                 }
1186                 cqr->callback = dasd_end_request_cb;
1187                 cqr->callback_data = (void *) req;
1188                 cqr->status = DASD_CQR_QUEUED;
1189                 blkdev_dequeue_request(req);
1190                 list_add_tail(&cqr->list, &device->ccw_queue);
1191                 dasd_profile_start(device, cqr, req);
1192                 nr_queued++;
1193         }
1194 }
1195
1196 /*
1197  * Take a look at the first request on the ccw queue and check
1198  * if it reached its expire time. If so, terminate the IO.
1199  */
1200 static inline void
1201 __dasd_check_expire(struct dasd_device * device)
1202 {
1203         struct dasd_ccw_req *cqr;
1204
1205         if (list_empty(&device->ccw_queue))
1206                 return;
1207         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1208         if (cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) {
1209                 if (time_after_eq(jiffies, cqr->expires + cqr->starttime)) {
1210                         if (device->discipline->term_IO(cqr) != 0)
1211                                 /* Hmpf, try again in 1/10 sec */
1212                                 dasd_set_timer(device, 10);
1213                 }
1214         }
1215 }
1216
1217 /*
1218  * Take a look at the first request on the ccw queue and check
1219  * if it needs to be started.
1220  */
1221 static inline void
1222 __dasd_start_head(struct dasd_device * device)
1223 {
1224         struct dasd_ccw_req *cqr;
1225         int rc;
1226
1227         if (list_empty(&device->ccw_queue))
1228                 return;
1229         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1230         if ((cqr->status == DASD_CQR_QUEUED) &&
1231             (!device->stopped)) {
1232                 /* try to start the first I/O that can be started */
1233                 rc = device->discipline->start_IO(cqr);
1234                 if (rc == 0)
1235                         dasd_set_timer(device, cqr->expires);
1236                 else if (rc == -EACCES) {
1237                         dasd_schedule_bh(device);
1238                 } else
1239                         /* Hmpf, try again in 1/2 sec */
1240                         dasd_set_timer(device, 50);
1241         }
1242 }
1243
1244 /*
1245  * Remove requests from the ccw queue.
1246  */
1247 static void
1248 dasd_flush_ccw_queue(struct dasd_device * device, int all)
1249 {
1250         struct list_head flush_queue;
1251         struct list_head *l, *n;
1252         struct dasd_ccw_req *cqr;
1253
1254         INIT_LIST_HEAD(&flush_queue);
1255         spin_lock_irq(get_ccwdev_lock(device->cdev));
1256         list_for_each_safe(l, n, &device->ccw_queue) {
1257                 cqr = list_entry(l, struct dasd_ccw_req, list);
1258                 /* Flush all request or only block device requests? */
1259                 if (all == 0 && cqr->callback == dasd_end_request_cb)
1260                         continue;
1261                 if (cqr->status == DASD_CQR_IN_IO)
1262                         device->discipline->term_IO(cqr);
1263                 if (cqr->status != DASD_CQR_DONE ||
1264                     cqr->status != DASD_CQR_FAILED) {
1265                         cqr->status = DASD_CQR_FAILED;
1266                         cqr->stopclk = get_clock();
1267                 }
1268                 /* Process finished ERP request. */
1269                 if (cqr->refers) {
1270                         __dasd_process_erp(device, cqr);
1271                         continue;
1272                 }
1273                 /* Rechain request on device request queue */
1274                 cqr->endclk = get_clock();
1275                 list_move_tail(&cqr->list, &flush_queue);
1276         }
1277         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1278         /* Now call the callback function of flushed requests */
1279         list_for_each_safe(l, n, &flush_queue) {
1280                 cqr = list_entry(l, struct dasd_ccw_req, list);
1281                 if (cqr->callback != NULL)
1282                         (cqr->callback)(cqr, cqr->callback_data);
1283         }
1284 }
1285
1286 /*
1287  * Acquire the device lock and process queues for the device.
1288  */
1289 static void
1290 dasd_tasklet(struct dasd_device * device)
1291 {
1292         struct list_head final_queue;
1293         struct list_head *l, *n;
1294         struct dasd_ccw_req *cqr;
1295
1296         atomic_set (&device->tasklet_scheduled, 0);
1297         INIT_LIST_HEAD(&final_queue);
1298         spin_lock_irq(get_ccwdev_lock(device->cdev));
1299         /* Check expire time of first request on the ccw queue. */
1300         __dasd_check_expire(device);
1301         /* Finish off requests on ccw queue */
1302         __dasd_process_ccw_queue(device, &final_queue);
1303         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1304         /* Now call the callback function of requests with final status */
1305         list_for_each_safe(l, n, &final_queue) {
1306                 cqr = list_entry(l, struct dasd_ccw_req, list);
1307                 list_del(&cqr->list);
1308                 if (cqr->callback != NULL)
1309                         (cqr->callback)(cqr, cqr->callback_data);
1310         }
1311         spin_lock_irq(&device->request_queue_lock);
1312         spin_lock(get_ccwdev_lock(device->cdev));
1313         /* Get new request from the block device request queue */
1314         __dasd_process_blk_queue(device);
1315         /* Now check if the head of the ccw queue needs to be started. */
1316         __dasd_start_head(device);
1317         spin_unlock(get_ccwdev_lock(device->cdev));
1318         spin_unlock_irq(&device->request_queue_lock);
1319         dasd_put_device(device);
1320 }
1321
1322 /*
1323  * Schedules a call to dasd_tasklet over the device tasklet.
1324  */
1325 void
1326 dasd_schedule_bh(struct dasd_device * device)
1327 {
1328         /* Protect against rescheduling. */
1329         if (atomic_compare_and_swap (0, 1, &device->tasklet_scheduled))
1330                 return;
1331         dasd_get_device(device);
1332         tasklet_hi_schedule(&device->tasklet);
1333 }
1334
1335 /*
1336  * Queue a request to the head of the ccw_queue. Start the I/O if
1337  * possible.
1338  */
1339 void
1340 dasd_add_request_head(struct dasd_ccw_req *req)
1341 {
1342         struct dasd_device *device;
1343         unsigned long flags;
1344
1345         device = req->device;
1346         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1347         req->status = DASD_CQR_QUEUED;
1348         req->device = device;
1349         list_add(&req->list, &device->ccw_queue);
1350         /* let the bh start the request to keep them in order */
1351         dasd_schedule_bh(device);
1352         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1353 }
1354
1355 /*
1356  * Queue a request to the tail of the ccw_queue. Start the I/O if
1357  * possible.
1358  */
1359 void
1360 dasd_add_request_tail(struct dasd_ccw_req *req)
1361 {
1362         struct dasd_device *device;
1363         unsigned long flags;
1364
1365         device = req->device;
1366         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1367         req->status = DASD_CQR_QUEUED;
1368         req->device = device;
1369         list_add_tail(&req->list, &device->ccw_queue);
1370         /* let the bh start the request to keep them in order */
1371         dasd_schedule_bh(device);
1372         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1373 }
1374
1375 /*
1376  * Wakeup callback.
1377  */
1378 static void
1379 dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
1380 {
1381         wake_up((wait_queue_head_t *) data);
1382 }
1383
1384 static inline int
1385 _wait_for_wakeup(struct dasd_ccw_req *cqr)
1386 {
1387         struct dasd_device *device;
1388         int rc;
1389
1390         device = cqr->device;
1391         spin_lock_irq(get_ccwdev_lock(device->cdev));
1392         rc = cqr->status == DASD_CQR_DONE || cqr->status == DASD_CQR_FAILED;
1393         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1394         return rc;
1395 }
1396
1397 /*
1398  * Attempts to start a special ccw queue and waits for its completion.
1399  */
1400 int
1401 dasd_sleep_on(struct dasd_ccw_req * cqr)
1402 {
1403         wait_queue_head_t wait_q;
1404         struct dasd_device *device;
1405         int rc;
1406
1407         device = cqr->device;
1408         spin_lock_irq(get_ccwdev_lock(device->cdev));
1409
1410         init_waitqueue_head (&wait_q);
1411         cqr->callback = dasd_wakeup_cb;
1412         cqr->callback_data = (void *) &wait_q;
1413         cqr->status = DASD_CQR_QUEUED;
1414         list_add_tail(&cqr->list, &device->ccw_queue);
1415
1416         /* let the bh start the request to keep them in order */
1417         dasd_schedule_bh(device);
1418
1419         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1420
1421         wait_event(wait_q, _wait_for_wakeup(cqr));
1422
1423         /* Request status is either done or failed. */
1424         rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1425         return rc;
1426 }
1427
1428 /*
1429  * Attempts to start a special ccw queue and wait interruptible
1430  * for its completion.
1431  */
1432 int
1433 dasd_sleep_on_interruptible(struct dasd_ccw_req * cqr)
1434 {
1435         wait_queue_head_t wait_q;
1436         struct dasd_device *device;
1437         int rc, finished;
1438
1439         device = cqr->device;
1440         spin_lock_irq(get_ccwdev_lock(device->cdev));
1441
1442         init_waitqueue_head (&wait_q);
1443         cqr->callback = dasd_wakeup_cb;
1444         cqr->callback_data = (void *) &wait_q;
1445         cqr->status = DASD_CQR_QUEUED;
1446         list_add_tail(&cqr->list, &device->ccw_queue);
1447
1448         /* let the bh start the request to keep them in order */
1449         dasd_schedule_bh(device);
1450         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1451
1452         finished = 0;
1453         while (!finished) {
1454                 rc = wait_event_interruptible(wait_q, _wait_for_wakeup(cqr));
1455                 if (rc != -ERESTARTSYS) {
1456                         /* Request status is either done or failed. */
1457                         rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1458                         break;
1459                 }
1460                 spin_lock_irq(get_ccwdev_lock(device->cdev));
1461                 if (cqr->status == DASD_CQR_IN_IO &&
1462                     device->discipline->term_IO(cqr) == 0) {
1463                         list_del(&cqr->list);
1464                         finished = 1;
1465                 }
1466                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1467         }
1468         return rc;
1469 }
1470
1471 /*
1472  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
1473  * for eckd devices) the currently running request has to be terminated
1474  * and be put back to status queued, before the special request is added
1475  * to the head of the queue. Then the special request is waited on normally.
1476  */
1477 static inline int
1478 _dasd_term_running_cqr(struct dasd_device *device)
1479 {
1480         struct dasd_ccw_req *cqr;
1481         int rc;
1482
1483         if (list_empty(&device->ccw_queue))
1484                 return 0;
1485         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1486         rc = device->discipline->term_IO(cqr);
1487         if (rc == 0) {
1488                 /* termination successful */
1489                 cqr->status = DASD_CQR_QUEUED;
1490                 cqr->startclk = cqr->stopclk = 0;
1491                 cqr->starttime = 0;
1492         }
1493         return rc;
1494 }
1495
1496 int
1497 dasd_sleep_on_immediatly(struct dasd_ccw_req * cqr)
1498 {
1499         wait_queue_head_t wait_q;
1500         struct dasd_device *device;
1501         int rc;
1502
1503         device = cqr->device;
1504         spin_lock_irq(get_ccwdev_lock(device->cdev));
1505         rc = _dasd_term_running_cqr(device);
1506         if (rc) {
1507                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1508                 return rc;
1509         }
1510
1511         init_waitqueue_head (&wait_q);
1512         cqr->callback = dasd_wakeup_cb;
1513         cqr->callback_data = (void *) &wait_q;
1514         cqr->status = DASD_CQR_QUEUED;
1515         list_add(&cqr->list, &device->ccw_queue);
1516
1517         /* let the bh start the request to keep them in order */
1518         dasd_schedule_bh(device);
1519
1520         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1521
1522         wait_event(wait_q, _wait_for_wakeup(cqr));
1523
1524         /* Request status is either done or failed. */
1525         rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1526         return rc;
1527 }
1528
1529 /*
1530  * Cancels a request that was started with dasd_sleep_on_req.
1531  * This is useful to timeout requests. The request will be
1532  * terminated if it is currently in i/o.
1533  * Returns 1 if the request has been terminated.
1534  */
1535 int
1536 dasd_cancel_req(struct dasd_ccw_req *cqr)
1537 {
1538         struct dasd_device *device = cqr->device;
1539         unsigned long flags;
1540         int rc;
1541
1542         rc = 0;
1543         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1544         switch (cqr->status) {
1545         case DASD_CQR_QUEUED:
1546                 /* request was not started - just set to failed */
1547                 cqr->status = DASD_CQR_FAILED;
1548                 break;
1549         case DASD_CQR_IN_IO:
1550                 /* request in IO - terminate IO and release again */
1551                 if (device->discipline->term_IO(cqr) != 0)
1552                         /* what to do if unable to terminate ??????
1553                            e.g. not _IN_IO */
1554                         cqr->status = DASD_CQR_FAILED;
1555                 cqr->stopclk = get_clock();
1556                 rc = 1;
1557                 break;
1558         case DASD_CQR_DONE:
1559         case DASD_CQR_FAILED:
1560                 /* already finished - do nothing */
1561                 break;
1562         default:
1563                 DEV_MESSAGE(KERN_ALERT, device,
1564                             "invalid status %02x in request",
1565                             cqr->status);
1566                 BUG();
1567
1568         }
1569         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1570         dasd_schedule_bh(device);
1571         return rc;
1572 }
1573
1574 /*
1575  * SECTION: Block device operations (request queue, partitions, open, release).
1576  */
1577
1578 /*
1579  * Dasd request queue function. Called from ll_rw_blk.c
1580  */
1581 static void
1582 do_dasd_request(request_queue_t * queue)
1583 {
1584         struct dasd_device *device;
1585
1586         device = (struct dasd_device *) queue->queuedata;
1587         spin_lock(get_ccwdev_lock(device->cdev));
1588         /* Get new request from the block device request queue */
1589         __dasd_process_blk_queue(device);
1590         /* Now check if the head of the ccw queue needs to be started. */
1591         __dasd_start_head(device);
1592         spin_unlock(get_ccwdev_lock(device->cdev));
1593 }
1594
1595 /*
1596  * Allocate and initialize request queue and default I/O scheduler.
1597  */
1598 static int
1599 dasd_alloc_queue(struct dasd_device * device)
1600 {
1601         int rc;
1602
1603         device->request_queue = blk_init_queue(do_dasd_request,
1604                                                &device->request_queue_lock);
1605         if (device->request_queue == NULL)
1606                 return -ENOMEM;
1607
1608         device->request_queue->queuedata = device;
1609
1610         elevator_exit(device->request_queue->elevator);
1611         rc = elevator_init(device->request_queue, "deadline");
1612         if (rc) {
1613                 blk_cleanup_queue(device->request_queue);
1614                 return rc;
1615         }
1616         return 0;
1617 }
1618
1619 /*
1620  * Allocate and initialize request queue.
1621  */
1622 static void
1623 dasd_setup_queue(struct dasd_device * device)
1624 {
1625         int max;
1626
1627         blk_queue_hardsect_size(device->request_queue, device->bp_block);
1628         max = device->discipline->max_blocks << device->s2b_shift;
1629         blk_queue_max_sectors(device->request_queue, max);
1630         blk_queue_max_phys_segments(device->request_queue, -1L);
1631         blk_queue_max_hw_segments(device->request_queue, -1L);
1632         blk_queue_max_segment_size(device->request_queue, -1L);
1633         blk_queue_segment_boundary(device->request_queue, -1L);
1634 }
1635
1636 /*
1637  * Deactivate and free request queue.
1638  */
1639 static void
1640 dasd_free_queue(struct dasd_device * device)
1641 {
1642         if (device->request_queue) {
1643                 blk_cleanup_queue(device->request_queue);
1644                 device->request_queue = NULL;
1645         }
1646 }
1647
1648 /*
1649  * Flush request on the request queue.
1650  */
1651 static void
1652 dasd_flush_request_queue(struct dasd_device * device)
1653 {
1654         struct request *req;
1655
1656         if (!device->request_queue)
1657                 return;
1658
1659         spin_lock_irq(&device->request_queue_lock);
1660         while (!list_empty(&device->request_queue->queue_head)) {
1661                 req = elv_next_request(device->request_queue);
1662                 if (req == NULL)
1663                         break;
1664                 dasd_end_request(req, 0);
1665                 blkdev_dequeue_request(req);
1666         }
1667         spin_unlock_irq(&device->request_queue_lock);
1668 }
1669
1670 static int
1671 dasd_open(struct inode *inp, struct file *filp)
1672 {
1673         struct gendisk *disk = inp->i_bdev->bd_disk;
1674         struct dasd_device *device = disk->private_data;
1675         int rc;
1676
1677         atomic_inc(&device->open_count);
1678         if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1679                 rc = -ENODEV;
1680                 goto unlock;
1681         }
1682
1683         if (!try_module_get(device->discipline->owner)) {
1684                 rc = -EINVAL;
1685                 goto unlock;
1686         }
1687
1688         if (dasd_probeonly) {
1689                 DEV_MESSAGE(KERN_INFO, device, "%s",
1690                             "No access to device due to probeonly mode");
1691                 rc = -EPERM;
1692                 goto out;
1693         }
1694
1695         if (device->state < DASD_STATE_BASIC) {
1696                 DBF_DEV_EVENT(DBF_ERR, device, " %s",
1697                               " Cannot open unrecognized device");
1698                 rc = -ENODEV;
1699                 goto out;
1700         }
1701
1702         return 0;
1703
1704 out:
1705         module_put(device->discipline->owner);
1706 unlock:
1707         atomic_dec(&device->open_count);
1708         return rc;
1709 }
1710
1711 static int
1712 dasd_release(struct inode *inp, struct file *filp)
1713 {
1714         struct gendisk *disk = inp->i_bdev->bd_disk;
1715         struct dasd_device *device = disk->private_data;
1716
1717         atomic_dec(&device->open_count);
1718         module_put(device->discipline->owner);
1719         return 0;
1720 }
1721
1722 struct block_device_operations
1723 dasd_device_operations = {
1724         .owner          = THIS_MODULE,
1725         .open           = dasd_open,
1726         .release        = dasd_release,
1727         .ioctl          = dasd_ioctl,
1728 };
1729
1730
1731 static void
1732 dasd_exit(void)
1733 {
1734 #ifdef CONFIG_PROC_FS
1735         dasd_proc_exit();
1736 #endif
1737         dasd_ioctl_exit();
1738         dasd_gendisk_exit();
1739         dasd_devmap_exit();
1740         devfs_remove("dasd");
1741         if (dasd_debug_area != NULL) {
1742                 debug_unregister(dasd_debug_area);
1743                 dasd_debug_area = NULL;
1744         }
1745 }
1746
1747 /*
1748  * SECTION: common functions for ccw_driver use
1749  */
1750
1751 /* initial attempt at a probe function. this can be simplified once
1752  * the other detection code is gone */
1753 int
1754 dasd_generic_probe (struct ccw_device *cdev,
1755                     struct dasd_discipline *discipline)
1756 {
1757         int ret;
1758
1759         ret = dasd_add_sysfs_files(cdev);
1760         if (ret) {
1761                 printk(KERN_WARNING
1762                        "dasd_generic_probe: could not add sysfs entries "
1763                        "for %s\n", cdev->dev.bus_id);
1764         }
1765
1766         cdev->handler = &dasd_int_handler;
1767
1768         return ret;
1769 }
1770
1771 /* this will one day be called from a global not_oper handler.
1772  * It is also used by driver_unregister during module unload */
1773 void
1774 dasd_generic_remove (struct ccw_device *cdev)
1775 {
1776         struct dasd_device *device;
1777
1778         dasd_remove_sysfs_files(cdev);
1779         device = dasd_device_from_cdev(cdev);
1780         if (IS_ERR(device))
1781                 return;
1782         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1783                 /* Already doing offline processing */
1784                 dasd_put_device(device);
1785                 return;
1786         }
1787         /*
1788          * This device is removed unconditionally. Set offline
1789          * flag to prevent dasd_open from opening it while it is
1790          * no quite down yet.
1791          */
1792         dasd_set_target_state(device, DASD_STATE_NEW);
1793         /* dasd_delete_device destroys the device reference. */
1794         dasd_delete_device(device);
1795 }
1796
1797 /* activate a device. This is called from dasd_{eckd,fba}_probe() when either
1798  * the device is detected for the first time and is supposed to be used
1799  * or the user has started activation through sysfs */
1800 int
1801 dasd_generic_set_online (struct ccw_device *cdev,
1802                          struct dasd_discipline *discipline)
1803
1804 {
1805         struct dasd_device *device;
1806         int rc;
1807
1808         device = dasd_create_device(cdev);
1809         if (IS_ERR(device))
1810                 return PTR_ERR(device);
1811
1812         if (test_bit(DASD_FLAG_USE_DIAG, &device->flags)) {
1813                 if (!dasd_diag_discipline_pointer) {
1814                         printk (KERN_WARNING
1815                                 "dasd_generic couldn't online device %s "
1816                                 "- discipline DIAG not available\n",
1817                                 cdev->dev.bus_id);
1818                         dasd_delete_device(device);
1819                         return -ENODEV;
1820                 }
1821                 discipline = dasd_diag_discipline_pointer;
1822         }
1823         device->discipline = discipline;
1824
1825         rc = discipline->check_device(device);
1826         if (rc) {
1827                 printk (KERN_WARNING
1828                         "dasd_generic couldn't online device %s "
1829                         "with discipline %s rc=%i\n",
1830                         cdev->dev.bus_id, discipline->name, rc);
1831                 dasd_delete_device(device);
1832                 return rc;
1833         }
1834
1835         dasd_set_target_state(device, DASD_STATE_ONLINE);
1836         if (device->state <= DASD_STATE_KNOWN) {
1837                 printk (KERN_WARNING
1838                         "dasd_generic discipline not found for %s\n",
1839                         cdev->dev.bus_id);
1840                 rc = -ENODEV;
1841                 dasd_set_target_state(device, DASD_STATE_NEW);
1842                 dasd_delete_device(device);
1843         } else
1844                 pr_debug("dasd_generic device %s found\n",
1845                                 cdev->dev.bus_id);
1846
1847         /* FIXME: we have to wait for the root device but we don't want
1848          * to wait for each single device but for all at once. */
1849         wait_event(dasd_init_waitq, _wait_for_device(device));
1850
1851         dasd_put_device(device);
1852
1853         return rc;
1854 }
1855
1856 int
1857 dasd_generic_set_offline (struct ccw_device *cdev)
1858 {
1859         struct dasd_device *device;
1860         int max_count;
1861
1862         device = dasd_device_from_cdev(cdev);
1863         if (IS_ERR(device))
1864                 return PTR_ERR(device);
1865         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1866                 /* Already doing offline processing */
1867                 dasd_put_device(device);
1868                 return 0;
1869         }
1870         /*
1871          * We must make sure that this device is currently not in use.
1872          * The open_count is increased for every opener, that includes
1873          * the blkdev_get in dasd_scan_partitions. We are only interested
1874          * in the other openers.
1875          */
1876         max_count = device->bdev ? 0 : -1;
1877         if (atomic_read(&device->open_count) > max_count) {
1878                 printk (KERN_WARNING "Can't offline dasd device with open"
1879                         " count = %i.\n",
1880                         atomic_read(&device->open_count));
1881                 clear_bit(DASD_FLAG_OFFLINE, &device->flags);
1882                 dasd_put_device(device);
1883                 return -EBUSY;
1884         }
1885         dasd_set_target_state(device, DASD_STATE_NEW);
1886         /* dasd_delete_device destroys the device reference. */
1887         dasd_delete_device(device);
1888
1889         return 0;
1890 }
1891
1892 int
1893 dasd_generic_notify(struct ccw_device *cdev, int event)
1894 {
1895         struct dasd_device *device;
1896         struct dasd_ccw_req *cqr;
1897         unsigned long flags;
1898         int ret;
1899
1900         device = dasd_device_from_cdev(cdev);
1901         if (IS_ERR(device))
1902                 return 0;
1903         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1904         ret = 0;
1905         switch (event) {
1906         case CIO_GONE:
1907         case CIO_NO_PATH:
1908                 if (device->state < DASD_STATE_BASIC)
1909                         break;
1910                 /* Device is active. We want to keep it. */
1911                 if (test_bit(DASD_FLAG_DSC_ERROR, &device->flags)) {
1912                         list_for_each_entry(cqr, &device->ccw_queue, list)
1913                                 if (cqr->status == DASD_CQR_IN_IO)
1914                                         cqr->status = DASD_CQR_FAILED;
1915                         device->stopped |= DASD_STOPPED_DC_EIO;
1916                         dasd_schedule_bh(device);
1917                 } else {
1918                         list_for_each_entry(cqr, &device->ccw_queue, list)
1919                                 if (cqr->status == DASD_CQR_IN_IO) {
1920                                         cqr->status = DASD_CQR_QUEUED;
1921                                         cqr->retries++;
1922                                 }
1923                         device->stopped |= DASD_STOPPED_DC_WAIT;
1924                         dasd_set_timer(device, 0);
1925                 }
1926                 ret = 1;
1927                 break;
1928         case CIO_OPER:
1929                 /* FIXME: add a sanity check. */
1930                 device->stopped &= ~(DASD_STOPPED_DC_WAIT|DASD_STOPPED_DC_EIO);
1931                 dasd_schedule_bh(device);
1932                 ret = 1;
1933                 break;
1934         }
1935         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1936         dasd_put_device(device);
1937         return ret;
1938 }
1939
1940 /*
1941  * Automatically online either all dasd devices (dasd_autodetect) or
1942  * all devices specified with dasd= parameters.
1943  */
1944 void
1945 dasd_generic_auto_online (struct ccw_driver *dasd_discipline_driver)
1946 {
1947         struct device_driver *drv;
1948         struct device *d, *dev;
1949         struct ccw_device *cdev;
1950
1951         drv = get_driver(&dasd_discipline_driver->driver);
1952         down_read(&drv->bus->subsys.rwsem);
1953         dev = NULL;
1954         list_for_each_entry(d, &drv->devices, driver_list) {
1955                 dev = get_device(d);
1956                 if (!dev)
1957                         continue;
1958                 cdev = to_ccwdev(dev);
1959                 if (dasd_autodetect || dasd_busid_known(cdev->dev.bus_id) == 0)
1960                         ccw_device_set_online(cdev);
1961                 put_device(dev);
1962         }
1963         up_read(&drv->bus->subsys.rwsem);
1964         put_driver(drv);
1965 }
1966
1967 static int __init
1968 dasd_init(void)
1969 {
1970         int rc;
1971
1972         init_waitqueue_head(&dasd_init_waitq);
1973
1974         /* register 'common' DASD debug area, used for all DBF_XXX calls */
1975         dasd_debug_area = debug_register("dasd", 0, 2, 8 * sizeof (long));
1976         if (dasd_debug_area == NULL) {
1977                 rc = -ENOMEM;
1978                 goto failed;
1979         }
1980         debug_register_view(dasd_debug_area, &debug_sprintf_view);
1981         debug_set_level(dasd_debug_area, DBF_EMERG);
1982
1983         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
1984
1985         dasd_diag_discipline_pointer = NULL;
1986
1987         rc = devfs_mk_dir("dasd");
1988         if (rc)
1989                 goto failed;
1990         rc = dasd_devmap_init();
1991         if (rc)
1992                 goto failed;
1993         rc = dasd_gendisk_init();
1994         if (rc)
1995                 goto failed;
1996         rc = dasd_parse();
1997         if (rc)
1998                 goto failed;
1999         rc = dasd_ioctl_init();
2000         if (rc)
2001                 goto failed;
2002 #ifdef CONFIG_PROC_FS
2003         rc = dasd_proc_init();
2004         if (rc)
2005                 goto failed;
2006 #endif
2007
2008         return 0;
2009 failed:
2010         MESSAGE(KERN_INFO, "%s", "initialization not performed due to errors");
2011         dasd_exit();
2012         return rc;
2013 }
2014
2015 module_init(dasd_init);
2016 module_exit(dasd_exit);
2017
2018 EXPORT_SYMBOL(dasd_debug_area);
2019 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
2020
2021 EXPORT_SYMBOL(dasd_add_request_head);
2022 EXPORT_SYMBOL(dasd_add_request_tail);
2023 EXPORT_SYMBOL(dasd_cancel_req);
2024 EXPORT_SYMBOL(dasd_clear_timer);
2025 EXPORT_SYMBOL(dasd_enable_device);
2026 EXPORT_SYMBOL(dasd_int_handler);
2027 EXPORT_SYMBOL(dasd_kfree_request);
2028 EXPORT_SYMBOL(dasd_kick_device);
2029 EXPORT_SYMBOL(dasd_kmalloc_request);
2030 EXPORT_SYMBOL(dasd_schedule_bh);
2031 EXPORT_SYMBOL(dasd_set_target_state);
2032 EXPORT_SYMBOL(dasd_set_timer);
2033 EXPORT_SYMBOL(dasd_sfree_request);
2034 EXPORT_SYMBOL(dasd_sleep_on);
2035 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2036 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2037 EXPORT_SYMBOL(dasd_smalloc_request);
2038 EXPORT_SYMBOL(dasd_start_IO);
2039 EXPORT_SYMBOL(dasd_term_IO);
2040
2041 EXPORT_SYMBOL_GPL(dasd_generic_probe);
2042 EXPORT_SYMBOL_GPL(dasd_generic_remove);
2043 EXPORT_SYMBOL_GPL(dasd_generic_notify);
2044 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
2045 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
2046 EXPORT_SYMBOL_GPL(dasd_generic_auto_online);
2047
2048 /*
2049  * Overrides for Emacs so that we follow Linus's tabbing style.
2050  * Emacs will notice this stuff at the end of the file and automatically
2051  * adjust the settings for this buffer only.  This must remain at the end
2052  * of the file.
2053  * ---------------------------------------------------------------------------
2054  * Local variables:
2055  * c-indent-level: 4
2056  * c-brace-imaginary-offset: 0
2057  * c-brace-offset: -4
2058  * c-argdecl-indent: 4
2059  * c-label-offset: -4
2060  * c-continued-statement-offset: 4
2061  * c-continued-brace-offset: 0
2062  * indent-tabs-mode: 1
2063  * tab-width: 8
2064  * End:
2065  */