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 #include <linux/notifier.h>
  22
  23 #include <asm/ccwdev.h>
  24 #include <asm/ebcdic.h>
  25 #include <asm/idals.h>
  26 #include <asm/todclk.h>
  27
  28 /* This is ugly... */
  29 #define PRINTK_HEADER "dasd:"
  30
  31 #include "dasd_int.h"
  32 /*
  33  * SECTION: Constant definitions to be used within this file
  34  */
  35 #define DASD_CHANQ_MAX_SIZE 4
  36
  37 /*
  38  * SECTION: exported variables of dasd.c
  39  */
  40 debug_info_t *dasd_debug_area;
  41 struct dasd_discipline *dasd_diag_discipline_pointer;
  42
  43 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
  44 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
  45                    " Copyright 2000 IBM Corporation");
  46 MODULE_SUPPORTED_DEVICE("dasd");
  47 MODULE_PARM(dasd, "1-" __MODULE_STRING(256) "s");
  48 MODULE_LICENSE("GPL");
  49
  50 /*
  51  * SECTION: prototypes for static functions of dasd.c
  52  */
  53 static int  dasd_alloc_queue(struct dasd_device * device);
  54 static void dasd_setup_queue(struct dasd_device * device);
  55 static void dasd_free_queue(struct dasd_device * device);
  56 static void dasd_flush_request_queue(struct dasd_device *);
  57 static void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
  58 static void dasd_flush_ccw_queue(struct dasd_device *, int);
  59 static void dasd_tasklet(struct dasd_device *);
  60 static void do_kick_device(void *data);
  61 static void dasd_disable_eer(struct dasd_device *device);
  62
  63 /*
  64  * SECTION: Operations on the device structure.
  65  */
  66 static wait_queue_head_t dasd_init_waitq;
  67
  68 /*
  69  * Allocate memory for a new device structure.
  70  */
  71 struct dasd_device *
  72 dasd_alloc_device(void)
  73 {
  74         struct dasd_device *device;
  75
  76         device = kmalloc(sizeof (struct dasd_device), GFP_ATOMIC);
  77         if (device == NULL)
  78                 return ERR_PTR(-ENOMEM);
  79         memset(device, 0, sizeof (struct dasd_device));
  80         /* open_count = 0 means device online but not in use */
  81         atomic_set(&device->open_count, -1);
  82
  83         /* Get two pages for normal block device operations. */
  84         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
  85         if (device->ccw_mem == NULL) {
  86                 kfree(device);
  87                 return ERR_PTR(-ENOMEM);
  88         }
  89         /* Get one page for error recovery. */
  90         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
  91         if (device->erp_mem == NULL) {
  92                 free_pages((unsigned long) device->ccw_mem, 1);
  93                 kfree(device);
  94                 return ERR_PTR(-ENOMEM);
  95         }
  96
  97         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
  98         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
  99         spin_lock_init(&device->mem_lock);
 100         spin_lock_init(&device->request_queue_lock);
 101         atomic_set (&device->tasklet_scheduled, 0);
 102         tasklet_init(&device->tasklet,
 103                      (void (*)(unsigned long)) dasd_tasklet,
 104                      (unsigned long) device);
 105         INIT_LIST_HEAD(&device->ccw_queue);
 106         init_timer(&device->timer);
 107         INIT_WORK(&device->kick_work, do_kick_device, device);
 108         device->state = DASD_STATE_NEW;
 109         device->target = DASD_STATE_NEW;
 110
 111         return device;
 112 }
 113
 114 /*
 115  * Free memory of a device structure.
 116  */
 117 void
 118 dasd_free_device(struct dasd_device *device)
 119 {
 120         kfree(device->private);
 121         free_page((unsigned long) device->erp_mem);
 122         free_pages((unsigned long) device->ccw_mem, 1);
 123         kfree(device);
 124 }
 125
 126 /*
 127  * Make a new device known to the system.
 128  */
 129 static inline int
 130 dasd_state_new_to_known(struct dasd_device *device)
 131 {
 132         int rc;
 133
 134         /*
 135          * As long as the device is not in state DASD_STATE_NEW we want to
 136          * keep the reference count > 0.
 137          */
 138         dasd_get_device(device);
 139
 140         rc = dasd_alloc_queue(device);
 141         if (rc) {
 142                 dasd_put_device(device);
 143                 return rc;
 144         }
 145
 146         device->state = DASD_STATE_KNOWN;
 147         return 0;
 148 }
 149
 150 /*
 151  * Let the system forget about a device.
 152  */
 153 static inline void
 154 dasd_state_known_to_new(struct dasd_device * device)
 155 {
 156         /* disable extended error reporting for this device */
 157         dasd_disable_eer(device);
 158         /* Forget the discipline information. */
 159         device->discipline = NULL;
 160         device->state = DASD_STATE_NEW;
 161
 162         dasd_free_queue(device);
 163
 164         /* Give up reference we took in dasd_state_new_to_known. */
 165         dasd_put_device(device);
 166 }
 167
 168 /*
 169  * Request the irq line for the device.
 170  */
 171 static inline int
 172 dasd_state_known_to_basic(struct dasd_device * device)
 173 {
 174         int rc;
 175
 176         /* Allocate and register gendisk structure. */
 177         rc = dasd_gendisk_alloc(device);
 178         if (rc)
 179                 return rc;
 180
 181         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 182         device->debug_area = debug_register(device->cdev->dev.bus_id, 1, 2,
 183                                             8 * sizeof (long));
 184         debug_register_view(device->debug_area, &debug_sprintf_view);
 185         debug_set_level(device->debug_area, DBF_EMERG);
 186         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 187
 188         device->state = DASD_STATE_BASIC;
 189         return 0;
 190 }
 191
 192 /*
 193  * Release the irq line for the device. Terminate any running i/o.
 194  */
 195 static inline void
 196 dasd_state_basic_to_known(struct dasd_device * device)
 197 {
 198         dasd_gendisk_free(device);
 199         dasd_flush_ccw_queue(device, 1);
 200         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
 201         if (device->debug_area != NULL) {
 202                 debug_unregister(device->debug_area);
 203                 device->debug_area = NULL;
 204         }
 205         device->state = DASD_STATE_KNOWN;
 206 }
 207
 208 /*
 209  * Do the initial analysis. The do_analysis function may return
 210  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 211  * until the discipline decides to continue the startup sequence
 212  * by calling the function dasd_change_state. The eckd disciplines
 213  * uses this to start a ccw that detects the format. The completion
 214  * interrupt for this detection ccw uses the kernel event daemon to
 215  * trigger the call to dasd_change_state. All this is done in the
 216  * discipline code, see dasd_eckd.c.
 217  * After the analysis ccw is done (do_analysis returned 0 or error)
 218  * the block device is setup. Either a fake disk is added to allow
 219  * formatting or a proper device request queue is created.
 220  */
 221 static inline int
 222 dasd_state_basic_to_ready(struct dasd_device * device)
 223 {
 224         int rc;
 225
 226         rc = 0;
 227         if (device->discipline->do_analysis != NULL)
 228                 rc = device->discipline->do_analysis(device);
 229         if (rc)
 230                 return rc;
 231         dasd_setup_queue(device);
 232         device->state = DASD_STATE_READY;
 233         if (dasd_scan_partitions(device) != 0)
 234                 device->state = DASD_STATE_BASIC;
 235         return 0;
 236 }
 237
 238 /*
 239  * Remove device from block device layer. Destroy dirty buffers.
 240  * Forget format information. Check if the target level is basic
 241  * and if it is create fake disk for formatting.
 242  */
 243 static inline void
 244 dasd_state_ready_to_basic(struct dasd_device * device)
 245 {
 246         dasd_flush_ccw_queue(device, 0);
 247         dasd_destroy_partitions(device);
 248         dasd_flush_request_queue(device);
 249         device->blocks = 0;
 250         device->bp_block = 0;
 251         device->s2b_shift = 0;
 252         device->state = DASD_STATE_BASIC;
 253 }
 254
 255 /*
 256  * Make the device online and schedule the bottom half to start
 257  * the requeueing of requests from the linux request queue to the
 258  * ccw queue.
 259  */
 260 static inline int
 261 dasd_state_ready_to_online(struct dasd_device * device)
 262 {
 263         device->state = DASD_STATE_ONLINE;
 264         dasd_schedule_bh(device);
 265         return 0;
 266 }
 267
 268 /*
 269  * Stop the requeueing of requests again.
 270  */
 271 static inline void
 272 dasd_state_online_to_ready(struct dasd_device * device)
 273 {
 274         device->state = DASD_STATE_READY;
 275 }
 276
 277 /*
 278  * Device startup state changes.
 279  */
 280 static inline int
 281 dasd_increase_state(struct dasd_device *device)
 282 {
 283         int rc;
 284
 285         rc = 0;
 286         if (device->state == DASD_STATE_NEW &&
 287             device->target >= DASD_STATE_KNOWN)
 288                 rc = dasd_state_new_to_known(device);
 289
 290         if (!rc &&
 291             device->state == DASD_STATE_KNOWN &&
 292             device->target >= DASD_STATE_BASIC)
 293                 rc = dasd_state_known_to_basic(device);
 294
 295         if (!rc &&
 296             device->state == DASD_STATE_BASIC &&
 297             device->target >= DASD_STATE_READY)
 298                 rc = dasd_state_basic_to_ready(device);
 299
 300         if (!rc &&
 301             device->state == DASD_STATE_READY &&
 302             device->target >= DASD_STATE_ONLINE)
 303                 rc = dasd_state_ready_to_online(device);
 304
 305         return rc;
 306 }
 307
 308 /*
 309  * Device shutdown state changes.
 310  */
 311 static inline int
 312 dasd_decrease_state(struct dasd_device *device)
 313 {
 314         if (device->state == DASD_STATE_ONLINE &&
 315             device->target <= DASD_STATE_READY)
 316                 dasd_state_online_to_ready(device);
 317
 318         if (device->state == DASD_STATE_READY &&
 319             device->target <= DASD_STATE_BASIC)
 320                 dasd_state_ready_to_basic(device);
 321
 322         if (device->state == DASD_STATE_BASIC &&
 323             device->target <= DASD_STATE_KNOWN)
 324                 dasd_state_basic_to_known(device);
 325
 326         if (device->state == DASD_STATE_KNOWN &&
 327             device->target <= DASD_STATE_NEW)
 328                 dasd_state_known_to_new(device);
 329
 330         return 0;
 331 }
 332
 333 /*
 334  * This is the main startup/shutdown routine.
 335  */
 336 static void
 337 dasd_change_state(struct dasd_device *device)
 338 {
 339         int rc;
 340
 341         if (device->state == device->target)
 342                 /* Already where we want to go today... */
 343                 return;
 344         if (device->state < device->target)
 345                 rc = dasd_increase_state(device);
 346         else
 347                 rc = dasd_decrease_state(device);
 348         if (rc && rc != -EAGAIN)
 349                 device->target = device->state;
 350
 351         if (device->state == device->target)
 352                 wake_up(&dasd_init_waitq);
 353 }
 354
 355 /*
 356  * Kick starter for devices that did not complete the startup/shutdown
 357  * procedure or were sleeping because of a pending state.
 358  * dasd_kick_device will schedule a call do do_kick_device to the kernel
 359  * event daemon.
 360  */
 361 static void
 362 do_kick_device(void *data)
 363 {
 364         struct dasd_device *device;
 365
 366         device = (struct dasd_device *) data;
 367         dasd_change_state(device);
 368         dasd_schedule_bh(device);
 369         dasd_put_device(device);
 370 }
 371
 372 void
 373 dasd_kick_device(struct dasd_device *device)
 374 {
 375         dasd_get_device(device);
 376         /* queue call to dasd_kick_device to the kernel event daemon. */
 377         schedule_work(&device->kick_work);
 378 }
 379
 380 /*
 381  * Set the target state for a device and starts the state change.
 382  */
 383 void
 384 dasd_set_target_state(struct dasd_device *device, int target)
 385 {
 386         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 387         if (dasd_probeonly && target > DASD_STATE_READY)
 388                 target = DASD_STATE_READY;
 389         if (device->target != target) {
 390                 if (device->state == target)
 391                         wake_up(&dasd_init_waitq);
 392                 device->target = target;
 393         }
 394         if (device->state != device->target)
 395                 dasd_change_state(device);
 396 }
 397
 398 /*
 399  * Enable devices with device numbers in [from..to].
 400  */
 401 static inline int
 402 _wait_for_device(struct dasd_device *device)
 403 {
 404         return (device->state == device->target);
 405 }
 406
 407 void
 408 dasd_enable_device(struct dasd_device *device)
 409 {
 410         dasd_set_target_state(device, DASD_STATE_ONLINE);
 411         if (device->state <= DASD_STATE_KNOWN)
 412                 /* No discipline for device found. */
 413                 dasd_set_target_state(device, DASD_STATE_NEW);
 414         /* Now wait for the devices to come up. */
 415         wait_event(dasd_init_waitq, _wait_for_device(device));
 416 }
 417
 418 /*
 419  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 420  */
 421 #ifdef CONFIG_DASD_PROFILE
 422
 423 struct dasd_profile_info_t dasd_global_profile;
 424 unsigned int dasd_profile_level = DASD_PROFILE_OFF;
 425
 426 /*
 427  * Increments counter in global and local profiling structures.
 428  */
 429 #define dasd_profile_counter(value, counter, device) \
 430 { \
 431         int index; \
 432         for (index = 0; index < 31 && value >> (2+index); index++); \
 433         dasd_global_profile.counter[index]++; \
 434         device->profile.counter[index]++; \
 435 }
 436
 437 /*
 438  * Add profiling information for cqr before execution.
 439  */
 440 static inline void
 441 dasd_profile_start(struct dasd_device *device, struct dasd_ccw_req * cqr,
 442                    struct request *req)
 443 {
 444         struct list_head *l;
 445         unsigned int counter;
 446
 447         if (dasd_profile_level != DASD_PROFILE_ON)
 448                 return;
 449
 450         /* count the length of the chanq for statistics */
 451         counter = 0;
 452         list_for_each(l, &device->ccw_queue)
 453                 if (++counter >= 31)
 454                         break;
 455         dasd_global_profile.dasd_io_nr_req[counter]++;
 456         device->profile.dasd_io_nr_req[counter]++;
 457 }
 458
 459 /*
 460  * Add profiling information for cqr after execution.
 461  */
 462 static inline void
 463 dasd_profile_end(struct dasd_device *device, struct dasd_ccw_req * cqr,
 464                  struct request *req)
 465 {
 466         long strtime, irqtime, endtime, tottime;        /* in microseconds */
 467         long tottimeps, sectors;
 468
 469         if (dasd_profile_level != DASD_PROFILE_ON)
 470                 return;
 471
 472         sectors = req->nr_sectors;
 473         if (!cqr->buildclk || !cqr->startclk ||
 474             !cqr->stopclk || !cqr->endclk ||
 475             !sectors)
 476                 return;
 477
 478         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 479         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 480         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 481         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 482         tottimeps = tottime / sectors;
 483
 484         if (!dasd_global_profile.dasd_io_reqs)
 485                 memset(&dasd_global_profile, 0,
 486                        sizeof (struct dasd_profile_info_t));
 487         dasd_global_profile.dasd_io_reqs++;
 488         dasd_global_profile.dasd_io_sects += sectors;
 489
 490         if (!device->profile.dasd_io_reqs)
 491                 memset(&device->profile, 0,
 492                        sizeof (struct dasd_profile_info_t));
 493         device->profile.dasd_io_reqs++;
 494         device->profile.dasd_io_sects += sectors;
 495
 496         dasd_profile_counter(sectors, dasd_io_secs, device);
 497         dasd_profile_counter(tottime, dasd_io_times, device);
 498         dasd_profile_counter(tottimeps, dasd_io_timps, device);
 499         dasd_profile_counter(strtime, dasd_io_time1, device);
 500         dasd_profile_counter(irqtime, dasd_io_time2, device);
 501         dasd_profile_counter(irqtime / sectors, dasd_io_time2ps, device);
 502         dasd_profile_counter(endtime, dasd_io_time3, device);
 503 }
 504 #else
 505 #define dasd_profile_start(device, cqr, req) do {} while (0)
 506 #define dasd_profile_end(device, cqr, req) do {} while (0)
 507 #endif                          /* CONFIG_DASD_PROFILE */
 508
 509 /*
 510  * Allocate memory for a channel program with 'cplength' channel
 511  * command words and 'datasize' additional space. There are two
 512  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
 513  * memory and 2) dasd_smalloc_request uses the static ccw memory
 514  * that gets allocated for each device.
 515  */
 516 struct dasd_ccw_req *
 517 dasd_kmalloc_request(char *magic, int cplength, int datasize,
 518                    struct dasd_device * device)
 519 {
 520         struct dasd_ccw_req *cqr;
 521
 522         /* Sanity checks */
 523         if ( magic == NULL || datasize > PAGE_SIZE ||
 524              (cplength*sizeof(struct ccw1)) > PAGE_SIZE)
 525                 BUG();
 526
 527         cqr = kmalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
 528         if (cqr == NULL)
 529                 return ERR_PTR(-ENOMEM);
 530         memset(cqr, 0, sizeof(struct dasd_ccw_req));
 531         cqr->cpaddr = NULL;
 532         if (cplength > 0) {
 533                 cqr->cpaddr = kmalloc(cplength*sizeof(struct ccw1),
 534                                       GFP_ATOMIC | GFP_DMA);
 535                 if (cqr->cpaddr == NULL) {
 536                         kfree(cqr);
 537                         return ERR_PTR(-ENOMEM);
 538                 }
 539                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
 540         }
 541         cqr->data = NULL;
 542         if (datasize > 0) {
 543                 cqr->data = kmalloc(datasize, GFP_ATOMIC | GFP_DMA);
 544                 if (cqr->data == NULL) {
 545                         kfree(cqr->cpaddr);
 546                         kfree(cqr);
 547                         return ERR_PTR(-ENOMEM);
 548                 }
 549                 memset(cqr->data, 0, datasize);
 550         }
 551         strncpy((char *) &cqr->magic, magic, 4);
 552         ASCEBC((char *) &cqr->magic, 4);
 553         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
 554         dasd_get_device(device);
 555         return cqr;
 556 }
 557
 558 struct dasd_ccw_req *
 559 dasd_smalloc_request(char *magic, int cplength, int datasize,
 560                    struct dasd_device * device)
 561 {
 562         unsigned long flags;
 563         struct dasd_ccw_req *cqr;
 564         char *data;
 565         int size;
 566
 567         /* Sanity checks */
 568         if ( magic == NULL || datasize > PAGE_SIZE ||
 569              (cplength*sizeof(struct ccw1)) > PAGE_SIZE)
 570                 BUG();
 571
 572         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
 573         if (cplength > 0)
 574                 size += cplength * sizeof(struct ccw1);
 575         if (datasize > 0)
 576                 size += datasize;
 577         spin_lock_irqsave(&device->mem_lock, flags);
 578         cqr = (struct dasd_ccw_req *)
 579                 dasd_alloc_chunk(&device->ccw_chunks, size);
 580         spin_unlock_irqrestore(&device->mem_lock, flags);
 581         if (cqr == NULL)
 582                 return ERR_PTR(-ENOMEM);
 583         memset(cqr, 0, sizeof(struct dasd_ccw_req));
 584         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
 585         cqr->cpaddr = NULL;
 586         if (cplength > 0) {
 587                 cqr->cpaddr = (struct ccw1 *) data;
 588                 data += cplength*sizeof(struct ccw1);
 589                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
 590         }
 591         cqr->data = NULL;
 592         if (datasize > 0) {
 593                 cqr->data = data;
 594                 memset(cqr->data, 0, datasize);
 595         }
 596         strncpy((char *) &cqr->magic, magic, 4);
 597         ASCEBC((char *) &cqr->magic, 4);
 598         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
 599         dasd_get_device(device);
 600         return cqr;
 601 }
 602
 603 /*
 604  * Free memory of a channel program. This function needs to free all the
 605  * idal lists that might have been created by dasd_set_cda and the
 606  * struct dasd_ccw_req itself.
 607  */
 608 void
 609 dasd_kfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
 610 {
 611 #ifdef CONFIG_64BIT
 612         struct ccw1 *ccw;
 613
 614         /* Clear any idals used for the request. */
 615         ccw = cqr->cpaddr;
 616         do {
 617                 clear_normalized_cda(ccw);
 618         } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
 619 #endif
 620         kfree(cqr->cpaddr);
 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                         cqr->retries--;
 682                         cqr->status = DASD_CQR_CLEAR;
 683                         cqr->stopclk = get_clock();
 684                         DBF_DEV_EVENT(DBF_DEBUG, device,
 685                                       "terminate cqr %p successful",
 686                                       cqr);
 687                         break;
 688                 case -ENODEV:
 689                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 690                                       "device gone, retry");
 691                         break;
 692                 case -EIO:
 693                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 694                                       "I/O error, retry");
 695                         break;
 696                 case -EINVAL:
 697                 case -EBUSY:
 698                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 699                                       "device busy, retry later");
 700                         break;
 701                 default:
 702                         DEV_MESSAGE(KERN_ERR, device,
 703                                     "line %d unknown RC=%d, please "
 704                                     "report to linux390@de.ibm.com",
 705                                     __LINE__, rc);
 706                         BUG();
 707                         break;
 708                 }
 709                 retries++;
 710         }
 711         dasd_schedule_bh(device);
 712         return rc;
 713 }
 714
 715 /*
 716  * Start the i/o. This start_IO can fail if the channel is really busy.
 717  * In that case set up a timer to start the request later.
 718  */
 719 int
 720 dasd_start_IO(struct dasd_ccw_req * cqr)
 721 {
 722         struct dasd_device *device;
 723         int rc;
 724
 725         /* Check the cqr */
 726         rc = dasd_check_cqr(cqr);
 727         if (rc)
 728                 return rc;
 729         device = (struct dasd_device *) cqr->device;
 730         if (cqr->retries < 0) {
 731                 DEV_MESSAGE(KERN_DEBUG, device,
 732                             "start_IO: request %p (%02x/%i) - no retry left.",
 733                             cqr, cqr->status, cqr->retries);
 734                 cqr->status = DASD_CQR_FAILED;
 735                 return -EIO;
 736         }
 737         cqr->startclk = get_clock();
 738         cqr->starttime = jiffies;
 739         cqr->retries--;
 740         rc = ccw_device_start(device->cdev, cqr->cpaddr, (long) cqr,
 741                               cqr->lpm, 0);
 742         switch (rc) {
 743         case 0:
 744                 cqr->status = DASD_CQR_IN_IO;
 745                 DBF_DEV_EVENT(DBF_DEBUG, device,
 746                               "start_IO: request %p started successful",
 747                               cqr);
 748                 break;
 749         case -EBUSY:
 750                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 751                               "start_IO: device busy, retry later");
 752                 break;
 753         case -ETIMEDOUT:
 754                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 755                               "start_IO: request timeout, retry later");
 756                 break;
 757         case -EACCES:
 758                 /* -EACCES indicates that the request used only a
 759                  * subset of the available pathes and all these
 760                  * pathes are gone.
 761                  * Do a retry with all available pathes.
 762                  */
 763                 cqr->lpm = LPM_ANYPATH;
 764                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 765                               "start_IO: selected pathes gone,"
 766                               " retry on all pathes");
 767                 break;
 768         case -ENODEV:
 769         case -EIO:
 770                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 771                               "start_IO: device gone, retry");
 772                 break;
 773         default:
 774                 DEV_MESSAGE(KERN_ERR, device,
 775                             "line %d unknown RC=%d, please report"
 776                             " to linux390@de.ibm.com", __LINE__, rc);
 777                 BUG();
 778                 break;
 779         }
 780         return rc;
 781 }
 782
 783 /*
 784  * Timeout function for dasd devices. This is used for different purposes
 785  *  1) missing interrupt handler for normal operation
 786  *  2) delayed start of request where start_IO failed with -EBUSY
 787  *  3) timeout for missing state change interrupts
 788  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
 789  * DASD_CQR_QUEUED for 2) and 3).
 790  */
 791 static void
 792 dasd_timeout_device(unsigned long ptr)
 793 {
 794         unsigned long flags;
 795         struct dasd_device *device;
 796
 797         device = (struct dasd_device *) ptr;
 798         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
 799         /* re-activate request queue */
 800         device->stopped &= ~DASD_STOPPED_PENDING;
 801         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
 802         dasd_schedule_bh(device);
 803 }
 804
 805 /*
 806  * Setup timeout for a device in jiffies.
 807  */
 808 void
 809 dasd_set_timer(struct dasd_device *device, int expires)
 810 {
 811         if (expires == 0) {
 812                 if (timer_pending(&device->timer))
 813                         del_timer(&device->timer);
 814                 return;
 815         }
 816         if (timer_pending(&device->timer)) {
 817                 if (mod_timer(&device->timer, jiffies + expires))
 818                         return;
 819         }
 820         device->timer.function = dasd_timeout_device;
 821         device->timer.data = (unsigned long) device;
 822         device->timer.expires = jiffies + expires;
 823         add_timer(&device->timer);
 824 }
 825
 826 /*
 827  * Clear timeout for a device.
 828  */
 829 void
 830 dasd_clear_timer(struct dasd_device *device)
 831 {
 832         if (timer_pending(&device->timer))
 833                 del_timer(&device->timer);
 834 }
 835
 836 static void
 837 dasd_handle_killed_request(struct ccw_device *cdev, unsigned long intparm)
 838 {
 839         struct dasd_ccw_req *cqr;
 840         struct dasd_device *device;
 841
 842         cqr = (struct dasd_ccw_req *) intparm;
 843         if (cqr->status != DASD_CQR_IN_IO) {
 844                 MESSAGE(KERN_DEBUG,
 845                         "invalid status in handle_killed_request: "
 846                         "bus_id %s, status %02x",
 847                         cdev->dev.bus_id, cqr->status);
 848                 return;
 849         }
 850
 851         device = (struct dasd_device *) cqr->device;
 852         if (device == NULL ||
 853             device != dasd_device_from_cdev(cdev) ||
 854             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
 855                 MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
 856                         cdev->dev.bus_id);
 857                 return;
 858         }
 859
 860         /* Schedule request to be retried. */
 861         cqr->status = DASD_CQR_QUEUED;
 862
 863         dasd_clear_timer(device);
 864         dasd_schedule_bh(device);
 865         dasd_put_device(device);
 866 }
 867
 868 static void
 869 dasd_handle_state_change_pending(struct dasd_device *device)
 870 {
 871         struct dasd_ccw_req *cqr;
 872         struct list_head *l, *n;
 873
 874         /* first of all call extended error reporting */
 875         dasd_write_eer_trigger(DASD_EER_STATECHANGE, device, NULL);
 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, uptodate);
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
1097                 /* first of all call extended error reporting */
1098                 if (device->eer && cqr->status == DASD_CQR_FAILED) {
1099                         dasd_write_eer_trigger(DASD_EER_FATALERROR,
1100                                                device, cqr);
1101
1102                         /* restart request  */
1103                         cqr->status = DASD_CQR_QUEUED;
1104                         cqr->retries = 255;
1105                         device->stopped |= DASD_STOPPED_QUIESCE;
1106                         goto restart;
1107                 }
1108
1109                 /* Process finished ERP request. */
1110                 if (cqr->refers) {
1111                         __dasd_process_erp(device, cqr);
1112                         goto restart;
1113                 }
1114
1115                 /* Rechain finished requests to final queue */
1116                 cqr->endclk = get_clock();
1117                 list_move_tail(&cqr->list, final_queue);
1118         }
1119 }
1120
1121 static void
1122 dasd_end_request_cb(struct dasd_ccw_req * cqr, void *data)
1123 {
1124         struct request *req;
1125         struct dasd_device *device;
1126         int status;
1127
1128         req = (struct request *) data;
1129         device = cqr->device;
1130         dasd_profile_end(device, cqr, req);
1131         status = cqr->device->discipline->free_cp(cqr,req);
1132         spin_lock_irq(&device->request_queue_lock);
1133         dasd_end_request(req, status);
1134         spin_unlock_irq(&device->request_queue_lock);
1135 }
1136
1137
1138 /*
1139  * Fetch requests from the block device queue.
1140  */
1141 static inline void
1142 __dasd_process_blk_queue(struct dasd_device * device)
1143 {
1144         request_queue_t *queue;
1145         struct request *req;
1146         struct dasd_ccw_req *cqr;
1147         int nr_queued;
1148
1149         queue = device->request_queue;
1150         /* No queue ? Then there is nothing to do. */
1151         if (queue == NULL)
1152                 return;
1153
1154         /*
1155          * We requeue request from the block device queue to the ccw
1156          * queue only in two states. In state DASD_STATE_READY the
1157          * partition detection is done and we need to requeue requests
1158          * for that. State DASD_STATE_ONLINE is normal block device
1159          * operation.
1160          */
1161         if (device->state != DASD_STATE_READY &&
1162             device->state != DASD_STATE_ONLINE)
1163                 return;
1164         nr_queued = 0;
1165         /* Now we try to fetch requests from the request queue */
1166         list_for_each_entry(cqr, &device->ccw_queue, list)
1167                 if (cqr->status == DASD_CQR_QUEUED)
1168                         nr_queued++;
1169         while (!blk_queue_plugged(queue) &&
1170                elv_next_request(queue) &&
1171                 nr_queued < DASD_CHANQ_MAX_SIZE) {
1172                 req = elv_next_request(queue);
1173
1174                 if (device->features & DASD_FEATURE_READONLY &&
1175                     rq_data_dir(req) == WRITE) {
1176                         DBF_DEV_EVENT(DBF_ERR, device,
1177                                       "Rejecting write request %p",
1178                                       req);
1179                         blkdev_dequeue_request(req);
1180                         dasd_end_request(req, 0);
1181                         continue;
1182                 }
1183                 if (device->stopped & DASD_STOPPED_DC_EIO) {
1184                         blkdev_dequeue_request(req);
1185                         dasd_end_request(req, 0);
1186                         continue;
1187                 }
1188                 cqr = device->discipline->build_cp(device, req);
1189                 if (IS_ERR(cqr)) {
1190                         if (PTR_ERR(cqr) == -ENOMEM)
1191                                 break;  /* terminate request queue loop */
1192                         DBF_DEV_EVENT(DBF_ERR, device,
1193                                       "CCW creation failed (rc=%ld) "
1194                                       "on request %p",
1195                                       PTR_ERR(cqr), req);
1196                         blkdev_dequeue_request(req);
1197                         dasd_end_request(req, 0);
1198                         continue;
1199                 }
1200                 cqr->callback = dasd_end_request_cb;
1201                 cqr->callback_data = (void *) req;
1202                 cqr->status = DASD_CQR_QUEUED;
1203                 blkdev_dequeue_request(req);
1204                 list_add_tail(&cqr->list, &device->ccw_queue);
1205                 dasd_profile_start(device, cqr, req);
1206                 nr_queued++;
1207         }
1208 }
1209
1210 /*
1211  * Take a look at the first request on the ccw queue and check
1212  * if it reached its expire time. If so, terminate the IO.
1213  */
1214 static inline void
1215 __dasd_check_expire(struct dasd_device * device)
1216 {
1217         struct dasd_ccw_req *cqr;
1218
1219         if (list_empty(&device->ccw_queue))
1220                 return;
1221         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1222         if (cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) {
1223                 if (time_after_eq(jiffies, cqr->expires + cqr->starttime)) {
1224                         if (device->discipline->term_IO(cqr) != 0)
1225                                 /* Hmpf, try again in 1/10 sec */
1226                                 dasd_set_timer(device, 10);
1227                 }
1228         }
1229 }
1230
1231 /*
1232  * Take a look at the first request on the ccw queue and check
1233  * if it needs to be started.
1234  */
1235 static inline void
1236 __dasd_start_head(struct dasd_device * device)
1237 {
1238         struct dasd_ccw_req *cqr;
1239         int rc;
1240
1241         if (list_empty(&device->ccw_queue))
1242                 return;
1243         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1244         /* check FAILFAST */
1245         if (device->stopped & ~DASD_STOPPED_PENDING &&
1246             test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
1247             (!device->eer)) {
1248                 cqr->status = DASD_CQR_FAILED;
1249                 dasd_schedule_bh(device);
1250         }
1251         if ((cqr->status == DASD_CQR_QUEUED) &&
1252             (!device->stopped)) {
1253                 /* try to start the first I/O that can be started */
1254                 rc = device->discipline->start_IO(cqr);
1255                 if (rc == 0)
1256                         dasd_set_timer(device, cqr->expires);
1257                 else if (rc == -EACCES) {
1258                         dasd_schedule_bh(device);
1259                 } else
1260                         /* Hmpf, try again in 1/2 sec */
1261                         dasd_set_timer(device, 50);
1262         }
1263 }
1264
1265 /*
1266  * Remove requests from the ccw queue.
1267  */
1268 static void
1269 dasd_flush_ccw_queue(struct dasd_device * device, int all)
1270 {
1271         struct list_head flush_queue;
1272         struct list_head *l, *n;
1273         struct dasd_ccw_req *cqr;
1274
1275         INIT_LIST_HEAD(&flush_queue);
1276         spin_lock_irq(get_ccwdev_lock(device->cdev));
1277         list_for_each_safe(l, n, &device->ccw_queue) {
1278                 cqr = list_entry(l, struct dasd_ccw_req, list);
1279                 /* Flush all request or only block device requests? */
1280                 if (all == 0 && cqr->callback == dasd_end_request_cb)
1281                         continue;
1282                 if (cqr->status == DASD_CQR_IN_IO)
1283                         device->discipline->term_IO(cqr);
1284                 if (cqr->status != DASD_CQR_DONE ||
1285                     cqr->status != DASD_CQR_FAILED) {
1286                         cqr->status = DASD_CQR_FAILED;
1287                         cqr->stopclk = get_clock();
1288                 }
1289                 /* Process finished ERP request. */
1290                 if (cqr->refers) {
1291                         __dasd_process_erp(device, cqr);
1292                         continue;
1293                 }
1294                 /* Rechain request on device request queue */
1295                 cqr->endclk = get_clock();
1296                 list_move_tail(&cqr->list, &flush_queue);
1297         }
1298         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1299         /* Now call the callback function of flushed requests */
1300         list_for_each_safe(l, n, &flush_queue) {
1301                 cqr = list_entry(l, struct dasd_ccw_req, list);
1302                 if (cqr->callback != NULL)
1303                         (cqr->callback)(cqr, cqr->callback_data);
1304         }
1305 }
1306
1307 /*
1308  * Acquire the device lock and process queues for the device.
1309  */
1310 static void
1311 dasd_tasklet(struct dasd_device * device)
1312 {
1313         struct list_head final_queue;
1314         struct list_head *l, *n;
1315         struct dasd_ccw_req *cqr;
1316
1317         atomic_set (&device->tasklet_scheduled, 0);
1318         INIT_LIST_HEAD(&final_queue);
1319         spin_lock_irq(get_ccwdev_lock(device->cdev));
1320         /* Check expire time of first request on the ccw queue. */
1321         __dasd_check_expire(device);
1322         /* Finish off requests on ccw queue */
1323         __dasd_process_ccw_queue(device, &final_queue);
1324         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1325         /* Now call the callback function of requests with final status */
1326         list_for_each_safe(l, n, &final_queue) {
1327                 cqr = list_entry(l, struct dasd_ccw_req, list);
1328                 list_del_init(&cqr->list);
1329                 if (cqr->callback != NULL)
1330                         (cqr->callback)(cqr, cqr->callback_data);
1331         }
1332         spin_lock_irq(&device->request_queue_lock);
1333         spin_lock(get_ccwdev_lock(device->cdev));
1334         /* Get new request from the block device request queue */
1335         __dasd_process_blk_queue(device);
1336         /* Now check if the head of the ccw queue needs to be started. */
1337         __dasd_start_head(device);
1338         spin_unlock(get_ccwdev_lock(device->cdev));
1339         spin_unlock_irq(&device->request_queue_lock);
1340         dasd_put_device(device);
1341 }
1342
1343 /*
1344  * Schedules a call to dasd_tasklet over the device tasklet.
1345  */
1346 void
1347 dasd_schedule_bh(struct dasd_device * device)
1348 {
1349         /* Protect against rescheduling. */
1350         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
1351                 return;
1352         dasd_get_device(device);
1353         tasklet_hi_schedule(&device->tasklet);
1354 }
1355
1356 /*
1357  * Queue a request to the head of the ccw_queue. Start the I/O if
1358  * possible.
1359  */
1360 void
1361 dasd_add_request_head(struct dasd_ccw_req *req)
1362 {
1363         struct dasd_device *device;
1364         unsigned long flags;
1365
1366         device = req->device;
1367         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1368         req->status = DASD_CQR_QUEUED;
1369         req->device = device;
1370         list_add(&req->list, &device->ccw_queue);
1371         /* let the bh start the request to keep them in order */
1372         dasd_schedule_bh(device);
1373         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1374 }
1375
1376 /*
1377  * Queue a request to the tail of the ccw_queue. Start the I/O if
1378  * possible.
1379  */
1380 void
1381 dasd_add_request_tail(struct dasd_ccw_req *req)
1382 {
1383         struct dasd_device *device;
1384         unsigned long flags;
1385
1386         device = req->device;
1387         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1388         req->status = DASD_CQR_QUEUED;
1389         req->device = device;
1390         list_add_tail(&req->list, &device->ccw_queue);
1391         /* let the bh start the request to keep them in order */
1392         dasd_schedule_bh(device);
1393         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1394 }
1395
1396 /*
1397  * Wakeup callback.
1398  */
1399 static void
1400 dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
1401 {
1402         wake_up((wait_queue_head_t *) data);
1403 }
1404
1405 static inline int
1406 _wait_for_wakeup(struct dasd_ccw_req *cqr)
1407 {
1408         struct dasd_device *device;
1409         int rc;
1410
1411         device = cqr->device;
1412         spin_lock_irq(get_ccwdev_lock(device->cdev));
1413         rc = ((cqr->status == DASD_CQR_DONE ||
1414                cqr->status == DASD_CQR_FAILED) &&
1415               list_empty(&cqr->list));
1416         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1417         return rc;
1418 }
1419
1420 /*
1421  * Attempts to start a special ccw queue and waits for its completion.
1422  */
1423 int
1424 dasd_sleep_on(struct dasd_ccw_req * cqr)
1425 {
1426         wait_queue_head_t wait_q;
1427         struct dasd_device *device;
1428         int rc;
1429
1430         device = cqr->device;
1431         spin_lock_irq(get_ccwdev_lock(device->cdev));
1432
1433         init_waitqueue_head (&wait_q);
1434         cqr->callback = dasd_wakeup_cb;
1435         cqr->callback_data = (void *) &wait_q;
1436         cqr->status = DASD_CQR_QUEUED;
1437         list_add_tail(&cqr->list, &device->ccw_queue);
1438
1439         /* let the bh start the request to keep them in order */
1440         dasd_schedule_bh(device);
1441
1442         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1443
1444         wait_event(wait_q, _wait_for_wakeup(cqr));
1445
1446         /* Request status is either done or failed. */
1447         rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1448         return rc;
1449 }
1450
1451 /*
1452  * Attempts to start a special ccw queue and wait interruptible
1453  * for its completion.
1454  */
1455 int
1456 dasd_sleep_on_interruptible(struct dasd_ccw_req * cqr)
1457 {
1458         wait_queue_head_t wait_q;
1459         struct dasd_device *device;
1460         int rc, finished;
1461
1462         device = cqr->device;
1463         spin_lock_irq(get_ccwdev_lock(device->cdev));
1464
1465         init_waitqueue_head (&wait_q);
1466         cqr->callback = dasd_wakeup_cb;
1467         cqr->callback_data = (void *) &wait_q;
1468         cqr->status = DASD_CQR_QUEUED;
1469         list_add_tail(&cqr->list, &device->ccw_queue);
1470
1471         /* let the bh start the request to keep them in order */
1472         dasd_schedule_bh(device);
1473         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1474
1475         finished = 0;
1476         while (!finished) {
1477                 rc = wait_event_interruptible(wait_q, _wait_for_wakeup(cqr));
1478                 if (rc != -ERESTARTSYS) {
1479                         /* Request is final (done or failed) */
1480                         rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO;
1481                         break;
1482                 }
1483                 spin_lock_irq(get_ccwdev_lock(device->cdev));
1484                 switch (cqr->status) {
1485                 case DASD_CQR_IN_IO:
1486                         /* terminate runnig cqr */
1487                         if (device->discipline->term_IO) {
1488                                 cqr->retries = -1;
1489                                 device->discipline->term_IO(cqr);
1490                                 /*nished =
1491                                  * wait (non-interruptible) for final status
1492                                  * because signal ist still pending
1493                                  */
1494                                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1495                                 wait_event(wait_q, _wait_for_wakeup(cqr));
1496                                 spin_lock_irq(get_ccwdev_lock(device->cdev));
1497                                 rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO;
1498                                 finished = 1;
1499                         }
1500                         break;
1501                 case DASD_CQR_QUEUED:
1502                         /* request  */
1503                         list_del_init(&cqr->list);
1504                         rc = -EIO;
1505                         finished = 1;
1506                         break;
1507                 default:
1508                         /* cqr with 'non-interruptable' status - just wait */
1509                         break;
1510                 }
1511                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1512         }
1513         return rc;
1514 }
1515
1516 /*
1517  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
1518  * for eckd devices) the currently running request has to be terminated
1519  * and be put back to status queued, before the special request is added
1520  * to the head of the queue. Then the special request is waited on normally.
1521  */
1522 static inline int
1523 _dasd_term_running_cqr(struct dasd_device *device)
1524 {
1525         struct dasd_ccw_req *cqr;
1526         int rc;
1527
1528         if (list_empty(&device->ccw_queue))
1529                 return 0;
1530         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1531         rc = device->discipline->term_IO(cqr);
1532         if (rc == 0) {
1533                 /* termination successful */
1534                 cqr->status = DASD_CQR_QUEUED;
1535                 cqr->startclk = cqr->stopclk = 0;
1536                 cqr->starttime = 0;
1537         }
1538         return rc;
1539 }
1540
1541 int
1542 dasd_sleep_on_immediatly(struct dasd_ccw_req * cqr)
1543 {
1544         wait_queue_head_t wait_q;
1545         struct dasd_device *device;
1546         int rc;
1547
1548         device = cqr->device;
1549         spin_lock_irq(get_ccwdev_lock(device->cdev));
1550         rc = _dasd_term_running_cqr(device);
1551         if (rc) {
1552                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1553                 return rc;
1554         }
1555
1556         init_waitqueue_head (&wait_q);
1557         cqr->callback = dasd_wakeup_cb;
1558         cqr->callback_data = (void *) &wait_q;
1559         cqr->status = DASD_CQR_QUEUED;
1560         list_add(&cqr->list, &device->ccw_queue);
1561
1562         /* let the bh start the request to keep them in order */
1563         dasd_schedule_bh(device);
1564
1565         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1566
1567         wait_event(wait_q, _wait_for_wakeup(cqr));
1568
1569         /* Request status is either done or failed. */
1570         rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1571         return rc;
1572 }
1573
1574 /*
1575  * Cancels a request that was started with dasd_sleep_on_req.
1576  * This is useful to timeout requests. The request will be
1577  * terminated if it is currently in i/o.
1578  * Returns 1 if the request has been terminated.
1579  */
1580 int
1581 dasd_cancel_req(struct dasd_ccw_req *cqr)
1582 {
1583         struct dasd_device *device = cqr->device;
1584         unsigned long flags;
1585         int rc;
1586
1587         rc = 0;
1588         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1589         switch (cqr->status) {
1590         case DASD_CQR_QUEUED:
1591                 /* request was not started - just set to failed */
1592                 cqr->status = DASD_CQR_FAILED;
1593                 break;
1594         case DASD_CQR_IN_IO:
1595                 /* request in IO - terminate IO and release again */
1596                 if (device->discipline->term_IO(cqr) != 0)
1597                         /* what to do if unable to terminate ??????
1598                            e.g. not _IN_IO */
1599                         cqr->status = DASD_CQR_FAILED;
1600                 cqr->stopclk = get_clock();
1601                 rc = 1;
1602                 break;
1603         case DASD_CQR_DONE:
1604         case DASD_CQR_FAILED:
1605                 /* already finished - do nothing */
1606                 break;
1607         default:
1608                 DEV_MESSAGE(KERN_ALERT, device,
1609                             "invalid status %02x in request",
1610                             cqr->status);
1611                 BUG();
1612
1613         }
1614         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1615         dasd_schedule_bh(device);
1616         return rc;
1617 }
1618
1619 /*
1620  * SECTION: Block device operations (request queue, partitions, open, release).
1621  */
1622
1623 /*
1624  * Dasd request queue function. Called from ll_rw_blk.c
1625  */
1626 static void
1627 do_dasd_request(request_queue_t * queue)
1628 {
1629         struct dasd_device *device;
1630
1631         device = (struct dasd_device *) queue->queuedata;
1632         spin_lock(get_ccwdev_lock(device->cdev));
1633         /* Get new request from the block device request queue */
1634         __dasd_process_blk_queue(device);
1635         /* Now check if the head of the ccw queue needs to be started. */
1636         __dasd_start_head(device);
1637         spin_unlock(get_ccwdev_lock(device->cdev));
1638 }
1639
1640 /*
1641  * Allocate and initialize request queue and default I/O scheduler.
1642  */
1643 static int
1644 dasd_alloc_queue(struct dasd_device * device)
1645 {
1646         int rc;
1647
1648         device->request_queue = blk_init_queue(do_dasd_request,
1649                                                &device->request_queue_lock);
1650         if (device->request_queue == NULL)
1651                 return -ENOMEM;
1652
1653         device->request_queue->queuedata = device;
1654
1655         elevator_exit(device->request_queue->elevator);
1656         rc = elevator_init(device->request_queue, "deadline");
1657         if (rc) {
1658                 blk_cleanup_queue(device->request_queue);
1659                 return rc;
1660         }
1661         return 0;
1662 }
1663
1664 /*
1665  * Allocate and initialize request queue.
1666  */
1667 static void
1668 dasd_setup_queue(struct dasd_device * device)
1669 {
1670         int max;
1671
1672         blk_queue_hardsect_size(device->request_queue, device->bp_block);
1673         max = device->discipline->max_blocks << device->s2b_shift;
1674         blk_queue_max_sectors(device->request_queue, max);
1675         blk_queue_max_phys_segments(device->request_queue, -1L);
1676         blk_queue_max_hw_segments(device->request_queue, -1L);
1677         blk_queue_max_segment_size(device->request_queue, -1L);
1678         blk_queue_segment_boundary(device->request_queue, -1L);
1679         blk_queue_ordered(device->request_queue, QUEUE_ORDERED_TAG, NULL);
1680 }
1681
1682 /*
1683  * Deactivate and free request queue.
1684  */
1685 static void
1686 dasd_free_queue(struct dasd_device * device)
1687 {
1688         if (device->request_queue) {
1689                 blk_cleanup_queue(device->request_queue);
1690                 device->request_queue = NULL;
1691         }
1692 }
1693
1694 /*
1695  * Flush request on the request queue.
1696  */
1697 static void
1698 dasd_flush_request_queue(struct dasd_device * device)
1699 {
1700         struct request *req;
1701
1702         if (!device->request_queue)
1703                 return;
1704
1705         spin_lock_irq(&device->request_queue_lock);
1706         while (!list_empty(&device->request_queue->queue_head)) {
1707                 req = elv_next_request(device->request_queue);
1708                 if (req == NULL)
1709                         break;
1710                 dasd_end_request(req, 0);
1711                 blkdev_dequeue_request(req);
1712         }
1713         spin_unlock_irq(&device->request_queue_lock);
1714 }
1715
1716 static int
1717 dasd_open(struct inode *inp, struct file *filp)
1718 {
1719         struct gendisk *disk = inp->i_bdev->bd_disk;
1720         struct dasd_device *device = disk->private_data;
1721         int rc;
1722
1723         atomic_inc(&device->open_count);
1724         if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1725                 rc = -ENODEV;
1726                 goto unlock;
1727         }
1728
1729         if (!try_module_get(device->discipline->owner)) {
1730                 rc = -EINVAL;
1731                 goto unlock;
1732         }
1733
1734         if (dasd_probeonly) {
1735                 DEV_MESSAGE(KERN_INFO, device, "%s",
1736                             "No access to device due to probeonly mode");
1737                 rc = -EPERM;
1738                 goto out;
1739         }
1740
1741         if (device->state < DASD_STATE_BASIC) {
1742                 DBF_DEV_EVENT(DBF_ERR, device, " %s",
1743                               " Cannot open unrecognized device");
1744                 rc = -ENODEV;
1745                 goto out;
1746         }
1747
1748         return 0;
1749
1750 out:
1751         module_put(device->discipline->owner);
1752 unlock:
1753         atomic_dec(&device->open_count);
1754         return rc;
1755 }
1756
1757 static int
1758 dasd_release(struct inode *inp, struct file *filp)
1759 {
1760         struct gendisk *disk = inp->i_bdev->bd_disk;
1761         struct dasd_device *device = disk->private_data;
1762
1763         atomic_dec(&device->open_count);
1764         module_put(device->discipline->owner);
1765         return 0;
1766 }
1767
1768 /*
1769  * Return disk geometry.
1770  */
1771 static int
1772 dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
1773 {
1774         struct dasd_device *device;
1775
1776         device = bdev->bd_disk->private_data;
1777         if (!device)
1778                 return -ENODEV;
1779
1780         if (!device->discipline ||
1781             !device->discipline->fill_geometry)
1782                 return -EINVAL;
1783
1784         device->discipline->fill_geometry(device, geo);
1785         geo->start = get_start_sect(bdev) >> device->s2b_shift;
1786         return 0;
1787 }
1788
1789 struct block_device_operations
1790 dasd_device_operations = {
1791         .owner          = THIS_MODULE,
1792         .open           = dasd_open,
1793         .release        = dasd_release,
1794         .ioctl          = dasd_ioctl,
1795         .compat_ioctl   = dasd_compat_ioctl,
1796         .getgeo         = dasd_getgeo,
1797 };
1798
1799
1800 static void
1801 dasd_exit(void)
1802 {
1803 #ifdef CONFIG_PROC_FS
1804         dasd_proc_exit();
1805 #endif
1806         dasd_ioctl_exit();
1807         if (dasd_page_cache != NULL) {
1808                 kmem_cache_destroy(dasd_page_cache);
1809                 dasd_page_cache = NULL;
1810         }
1811         dasd_gendisk_exit();
1812         dasd_devmap_exit();
1813         devfs_remove("dasd");
1814         if (dasd_debug_area != NULL) {
1815                 debug_unregister(dasd_debug_area);
1816                 dasd_debug_area = NULL;
1817         }
1818 }
1819
1820 /*
1821  * SECTION: common functions for ccw_driver use
1822  */
1823
1824 /*
1825  * Initial attempt at a probe function. this can be simplified once
1826  * the other detection code is gone.
1827  */
1828 int
1829 dasd_generic_probe (struct ccw_device *cdev,
1830                     struct dasd_discipline *discipline)
1831 {
1832         int ret;
1833
1834         ret = dasd_add_sysfs_files(cdev);
1835         if (ret) {
1836                 printk(KERN_WARNING
1837                        "dasd_generic_probe: could not add sysfs entries "
1838                        "for %s\n", cdev->dev.bus_id);
1839         } else {
1840                 cdev->handler = &dasd_int_handler;
1841         }
1842
1843         return ret;
1844 }
1845
1846 /*
1847  * This will one day be called from a global not_oper handler.
1848  * It is also used by driver_unregister during module unload.
1849  */
1850 void
1851 dasd_generic_remove (struct ccw_device *cdev)
1852 {
1853         struct dasd_device *device;
1854
1855         cdev->handler = NULL;
1856
1857         dasd_remove_sysfs_files(cdev);
1858         device = dasd_device_from_cdev(cdev);
1859         if (IS_ERR(device))
1860                 return;
1861         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1862                 /* Already doing offline processing */
1863                 dasd_put_device(device);
1864                 return;
1865         }
1866         /*
1867          * This device is removed unconditionally. Set offline
1868          * flag to prevent dasd_open from opening it while it is
1869          * no quite down yet.
1870          */
1871         dasd_set_target_state(device, DASD_STATE_NEW);
1872         /* dasd_delete_device destroys the device reference. */
1873         dasd_delete_device(device);
1874 }
1875
1876 /*
1877  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
1878  * the device is detected for the first time and is supposed to be used
1879  * or the user has started activation through sysfs.
1880  */
1881 int
1882 dasd_generic_set_online (struct ccw_device *cdev,
1883                          struct dasd_discipline *discipline)
1884
1885 {
1886         struct dasd_device *device;
1887         int rc;
1888
1889         device = dasd_create_device(cdev);
1890         if (IS_ERR(device))
1891                 return PTR_ERR(device);
1892
1893         if (device->features & DASD_FEATURE_USEDIAG) {
1894                 if (!dasd_diag_discipline_pointer) {
1895                         printk (KERN_WARNING
1896                                 "dasd_generic couldn't online device %s "
1897                                 "- discipline DIAG not available\n",
1898                                 cdev->dev.bus_id);
1899                         dasd_delete_device(device);
1900                         return -ENODEV;
1901                 }
1902                 discipline = dasd_diag_discipline_pointer;
1903         }
1904         device->discipline = discipline;
1905
1906         rc = discipline->check_device(device);
1907         if (rc) {
1908                 printk (KERN_WARNING
1909                         "dasd_generic couldn't online device %s "
1910                         "with discipline %s rc=%i\n",
1911                         cdev->dev.bus_id, discipline->name, rc);
1912                 dasd_delete_device(device);
1913                 return rc;
1914         }
1915
1916         dasd_set_target_state(device, DASD_STATE_ONLINE);
1917         if (device->state <= DASD_STATE_KNOWN) {
1918                 printk (KERN_WARNING
1919                         "dasd_generic discipline not found for %s\n",
1920                         cdev->dev.bus_id);
1921                 rc = -ENODEV;
1922                 dasd_set_target_state(device, DASD_STATE_NEW);
1923                 dasd_delete_device(device);
1924         } else
1925                 pr_debug("dasd_generic device %s found\n",
1926                                 cdev->dev.bus_id);
1927
1928         /* FIXME: we have to wait for the root device but we don't want
1929          * to wait for each single device but for all at once. */
1930         wait_event(dasd_init_waitq, _wait_for_device(device));
1931
1932         dasd_put_device(device);
1933
1934         return rc;
1935 }
1936
1937 int
1938 dasd_generic_set_offline (struct ccw_device *cdev)
1939 {
1940         struct dasd_device *device;
1941         int max_count;
1942
1943         device = dasd_device_from_cdev(cdev);
1944         if (IS_ERR(device))
1945                 return PTR_ERR(device);
1946         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1947                 /* Already doing offline processing */
1948                 dasd_put_device(device);
1949                 return 0;
1950         }
1951         /*
1952          * We must make sure that this device is currently not in use.
1953          * The open_count is increased for every opener, that includes
1954          * the blkdev_get in dasd_scan_partitions. We are only interested
1955          * in the other openers.
1956          */
1957         max_count = device->bdev ? 0 : -1;
1958         if (atomic_read(&device->open_count) > max_count) {
1959                 printk (KERN_WARNING "Can't offline dasd device with open"
1960                         " count = %i.\n",
1961                         atomic_read(&device->open_count));
1962                 clear_bit(DASD_FLAG_OFFLINE, &device->flags);
1963                 dasd_put_device(device);
1964                 return -EBUSY;
1965         }
1966         dasd_set_target_state(device, DASD_STATE_NEW);
1967         /* dasd_delete_device destroys the device reference. */
1968         dasd_delete_device(device);
1969
1970         return 0;
1971 }
1972
1973 int
1974 dasd_generic_notify(struct ccw_device *cdev, int event)
1975 {
1976         struct dasd_device *device;
1977         struct dasd_ccw_req *cqr;
1978         unsigned long flags;
1979         int ret;
1980
1981         device = dasd_device_from_cdev(cdev);
1982         if (IS_ERR(device))
1983                 return 0;
1984         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1985         ret = 0;
1986         switch (event) {
1987         case CIO_GONE:
1988         case CIO_NO_PATH:
1989                 /* first of all call extended error reporting */
1990                 dasd_write_eer_trigger(DASD_EER_NOPATH, device, NULL);
1991
1992                 if (device->state < DASD_STATE_BASIC)
1993                         break;
1994                 /* Device is active. We want to keep it. */
1995                 if (test_bit(DASD_FLAG_DSC_ERROR, &device->flags)) {
1996                         list_for_each_entry(cqr, &device->ccw_queue, list)
1997                                 if (cqr->status == DASD_CQR_IN_IO)
1998                                         cqr->status = DASD_CQR_FAILED;
1999                         device->stopped |= DASD_STOPPED_DC_EIO;
2000                 } else {
2001                         list_for_each_entry(cqr, &device->ccw_queue, list)
2002                                 if (cqr->status == DASD_CQR_IN_IO) {
2003                                         cqr->status = DASD_CQR_QUEUED;
2004                                         cqr->retries++;
2005                                 }
2006                         device->stopped |= DASD_STOPPED_DC_WAIT;
2007                         dasd_set_timer(device, 0);
2008                 }
2009                 dasd_schedule_bh(device);
2010                 ret = 1;
2011                 break;
2012         case CIO_OPER:
2013                 /* FIXME: add a sanity check. */
2014                 device->stopped &= ~(DASD_STOPPED_DC_WAIT|DASD_STOPPED_DC_EIO);
2015                 dasd_schedule_bh(device);
2016                 ret = 1;
2017                 break;
2018         }
2019         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
2020         dasd_put_device(device);
2021         return ret;
2022 }
2023
2024 /*
2025  * Automatically online either all dasd devices (dasd_autodetect) or
2026  * all devices specified with dasd= parameters.
2027  */
2028 static int
2029 __dasd_auto_online(struct device *dev, void *data)
2030 {
2031         struct ccw_device *cdev;
2032
2033         cdev = to_ccwdev(dev);
2034         if (dasd_autodetect || dasd_busid_known(cdev->dev.bus_id) == 0)
2035                 ccw_device_set_online(cdev);
2036         return 0;
2037 }
2038
2039 void
2040 dasd_generic_auto_online (struct ccw_driver *dasd_discipline_driver)
2041 {
2042         struct device_driver *drv;
2043
2044         drv = get_driver(&dasd_discipline_driver->driver);
2045         driver_for_each_device(drv, NULL, NULL, __dasd_auto_online);
2046         put_driver(drv);
2047 }
2048
2049 /*
2050  * notifications for extended error reports
2051  */
2052 static struct notifier_block *dasd_eer_chain;
2053
2054 int
2055 dasd_register_eer_notifier(struct notifier_block *nb)
2056 {
2057         return notifier_chain_register(&dasd_eer_chain, nb);
2058 }
2059
2060 int
2061 dasd_unregister_eer_notifier(struct notifier_block *nb)
2062 {
2063         return notifier_chain_unregister(&dasd_eer_chain, nb);
2064 }
2065
2066 /*
2067  * Notify the registered error reporting module of a problem
2068  */
2069 void
2070 dasd_write_eer_trigger(unsigned int id, struct dasd_device *device,
2071                        struct dasd_ccw_req *cqr)
2072 {
2073         if (device->eer) {
2074                 struct dasd_eer_trigger temp;
2075                 temp.id = id;
2076                 temp.device = device;
2077                 temp.cqr = cqr;
2078                 notifier_call_chain(&dasd_eer_chain, DASD_EER_TRIGGER,
2079                                     (void *)&temp);
2080         }
2081 }
2082
2083 /*
2084  * Tell the registered error reporting module to disable error reporting for
2085  * a given device and to cleanup any private data structures on that device.
2086  */
2087 static void
2088 dasd_disable_eer(struct dasd_device *device)
2089 {
2090         notifier_call_chain(&dasd_eer_chain, DASD_EER_DISABLE, (void *)device);
2091 }
2092
2093
2094 static int __init
2095 dasd_init(void)
2096 {
2097         int rc;
2098
2099         init_waitqueue_head(&dasd_init_waitq);
2100
2101         /* register 'common' DASD debug area, used for all DBF_XXX calls */
2102         dasd_debug_area = debug_register("dasd", 1, 2, 8 * sizeof (long));
2103         if (dasd_debug_area == NULL) {
2104                 rc = -ENOMEM;
2105                 goto failed;
2106         }
2107         debug_register_view(dasd_debug_area, &debug_sprintf_view);
2108         debug_set_level(dasd_debug_area, DBF_EMERG);
2109
2110         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
2111
2112         dasd_diag_discipline_pointer = NULL;
2113
2114         rc = devfs_mk_dir("dasd");
2115         if (rc)
2116                 goto failed;
2117         rc = dasd_devmap_init();
2118         if (rc)
2119                 goto failed;
2120         rc = dasd_gendisk_init();
2121         if (rc)
2122                 goto failed;
2123         rc = dasd_parse();
2124         if (rc)
2125                 goto failed;
2126         rc = dasd_ioctl_init();
2127         if (rc)
2128                 goto failed;
2129 #ifdef CONFIG_PROC_FS
2130         rc = dasd_proc_init();
2131         if (rc)
2132                 goto failed;
2133 #endif
2134
2135         return 0;
2136 failed:
2137         MESSAGE(KERN_INFO, "%s", "initialization not performed due to errors");
2138         dasd_exit();
2139         return rc;
2140 }
2141
2142 module_init(dasd_init);
2143 module_exit(dasd_exit);
2144
2145 EXPORT_SYMBOL(dasd_debug_area);
2146 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
2147
2148 EXPORT_SYMBOL(dasd_add_request_head);
2149 EXPORT_SYMBOL(dasd_add_request_tail);
2150 EXPORT_SYMBOL(dasd_cancel_req);
2151 EXPORT_SYMBOL(dasd_clear_timer);
2152 EXPORT_SYMBOL(dasd_enable_device);
2153 EXPORT_SYMBOL(dasd_int_handler);
2154 EXPORT_SYMBOL(dasd_kfree_request);
2155 EXPORT_SYMBOL(dasd_kick_device);
2156 EXPORT_SYMBOL(dasd_kmalloc_request);
2157 EXPORT_SYMBOL(dasd_schedule_bh);
2158 EXPORT_SYMBOL(dasd_set_target_state);
2159 EXPORT_SYMBOL(dasd_set_timer);
2160 EXPORT_SYMBOL(dasd_sfree_request);
2161 EXPORT_SYMBOL(dasd_sleep_on);
2162 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2163 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2164 EXPORT_SYMBOL(dasd_smalloc_request);
2165 EXPORT_SYMBOL(dasd_start_IO);
2166 EXPORT_SYMBOL(dasd_term_IO);
2167
2168 EXPORT_SYMBOL_GPL(dasd_generic_probe);
2169 EXPORT_SYMBOL_GPL(dasd_generic_remove);
2170 EXPORT_SYMBOL_GPL(dasd_generic_notify);
2171 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
2172 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
2173 EXPORT_SYMBOL_GPL(dasd_generic_auto_online);
2174
2175 EXPORT_SYMBOL(dasd_register_eer_notifier);
2176 EXPORT_SYMBOL(dasd_unregister_eer_notifier);
2177 EXPORT_SYMBOL(dasd_write_eer_trigger);
2178
2179
2180 /*
2181  * Overrides for Emacs so that we follow Linus's tabbing style.
2182  * Emacs will notice this stuff at the end of the file and automatically
2183  * adjust the settings for this buffer only.  This must remain at the end
2184  * of the file.
2185  * ---------------------------------------------------------------------------
2186  * Local variables:
2187  * c-indent-level: 4
2188  * c-brace-imaginary-offset: 0
2189  * c-brace-offset: -4
2190  * c-argdecl-indent: 4
2191  * c-label-offset: -4
2192  * c-continued-statement-offset: 4
2193  * c-continued-brace-offset: 0
2194  * indent-tabs-mode: 1
2195  * tab-width: 8
2196  * End:
2197  */