drivers/s390/block/dasd.c

   1 /*
   2  * File...........: linux/drivers/s390/block/dasd.c
   3  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
   4  *                  Horst Hummel <Horst.Hummel@de.ibm.com>
   5  *                  Carsten Otte <Cotte@de.ibm.com>
   6  *                  Martin Schwidefsky <schwidefsky@de.ibm.com>
   7  * Bugreports.to..: <Linux390@de.ibm.com>
   8  * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999-2001
   9  *
  10  */
  11
  12 #include <linux/kmod.h>
  13 #include <linux/init.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/ctype.h>
  16 #include <linux/major.h>
  17 #include <linux/slab.h>
  18 #include <linux/buffer_head.h>
  19 #include <linux/hdreg.h>
  20
  21 #include <asm/ccwdev.h>
  22 #include <asm/ebcdic.h>
  23 #include <asm/idals.h>
  24 #include <asm/todclk.h>
  25
  26 /* This is ugly... */
  27 #define PRINTK_HEADER "dasd:"
  28
  29 #include "dasd_int.h"
  30 /*
  31  * SECTION: Constant definitions to be used within this file
  32  */
  33 #define DASD_CHANQ_MAX_SIZE 4
  34
  35 /*
  36  * SECTION: exported variables of dasd.c
  37  */
  38 debug_info_t *dasd_debug_area;
  39 struct dasd_discipline *dasd_diag_discipline_pointer;
  40 void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
  41
  42 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
  43 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
  44                    " Copyright 2000 IBM Corporation");
  45 MODULE_SUPPORTED_DEVICE("dasd");
  46 MODULE_LICENSE("GPL");
  47
  48 /*
  49  * SECTION: prototypes for static functions of dasd.c
  50  */
  51 static int  dasd_alloc_queue(struct dasd_device * device);
  52 static void dasd_setup_queue(struct dasd_device * device);
  53 static void dasd_free_queue(struct dasd_device * device);
  54 static void dasd_flush_request_queue(struct dasd_device *);
  55 static int dasd_flush_ccw_queue(struct dasd_device *, int);
  56 static void dasd_tasklet(struct dasd_device *);
  57 static void do_kick_device(struct work_struct *);
  58
  59 /*
  60  * SECTION: Operations on the device structure.
  61  */
  62 static wait_queue_head_t dasd_init_waitq;
  63 static wait_queue_head_t dasd_flush_wq;
  64
  65 /*
  66  * Allocate memory for a new device structure.
  67  */
  68 struct dasd_device *
  69 dasd_alloc_device(void)
  70 {
  71         struct dasd_device *device;
  72
  73         device = kzalloc(sizeof (struct dasd_device), GFP_ATOMIC);
  74         if (device == NULL)
  75                 return ERR_PTR(-ENOMEM);
  76         /* open_count = 0 means device online but not in use */
  77         atomic_set(&device->open_count, -1);
  78
  79         /* Get two pages for normal block device operations. */
  80         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
  81         if (device->ccw_mem == NULL) {
  82                 kfree(device);
  83                 return ERR_PTR(-ENOMEM);
  84         }
  85         /* Get one page for error recovery. */
  86         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
  87         if (device->erp_mem == NULL) {
  88                 free_pages((unsigned long) device->ccw_mem, 1);
  89                 kfree(device);
  90                 return ERR_PTR(-ENOMEM);
  91         }
  92
  93         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
  94         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
  95         spin_lock_init(&device->mem_lock);
  96         spin_lock_init(&device->request_queue_lock);
  97         atomic_set (&device->tasklet_scheduled, 0);
  98         tasklet_init(&device->tasklet,
  99                      (void (*)(unsigned long)) dasd_tasklet,
 100                      (unsigned long) device);
 101         INIT_LIST_HEAD(&device->ccw_queue);
 102         init_timer(&device->timer);
 103         INIT_WORK(&device->kick_work, do_kick_device);
 104         device->state = DASD_STATE_NEW;
 105         device->target = DASD_STATE_NEW;
 106
 107         return device;
 108 }
 109
 110 /*
 111  * Free memory of a device structure.
 112  */
 113 void
 114 dasd_free_device(struct dasd_device *device)
 115 {
 116         kfree(device->private);
 117         free_page((unsigned long) device->erp_mem);
 118         free_pages((unsigned long) device->ccw_mem, 1);
 119         kfree(device);
 120 }
 121
 122 /*
 123  * Make a new device known to the system.
 124  */
 125 static int
 126 dasd_state_new_to_known(struct dasd_device *device)
 127 {
 128         int rc;
 129
 130         /*
 131          * As long as the device is not in state DASD_STATE_NEW we want to
 132          * keep the reference count > 0.
 133          */
 134         dasd_get_device(device);
 135
 136         rc = dasd_alloc_queue(device);
 137         if (rc) {
 138                 dasd_put_device(device);
 139                 return rc;
 140         }
 141
 142         device->state = DASD_STATE_KNOWN;
 143         return 0;
 144 }
 145
 146 /*
 147  * Let the system forget about a device.
 148  */
 149 static int
 150 dasd_state_known_to_new(struct dasd_device * device)
 151 {
 152         /* Disable extended error reporting for this device. */
 153         dasd_eer_disable(device);
 154         /* Forget the discipline information. */
 155         if (device->discipline)
 156                 module_put(device->discipline->owner);
 157         device->discipline = NULL;
 158         if (device->base_discipline)
 159                 module_put(device->base_discipline->owner);
 160         device->base_discipline = NULL;
 161         device->state = DASD_STATE_NEW;
 162
 163         dasd_free_queue(device);
 164
 165         /* Give up reference we took in dasd_state_new_to_known. */
 166         dasd_put_device(device);
 167         return 0;
 168 }
 169
 170 /*
 171  * Request the irq line for the device.
 172  */
 173 static int
 174 dasd_state_known_to_basic(struct dasd_device * device)
 175 {
 176         int rc;
 177
 178         /* Allocate and register gendisk structure. */
 179         rc = dasd_gendisk_alloc(device);
 180         if (rc)
 181                 return rc;
 182
 183         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 184         device->debug_area = debug_register(device->cdev->dev.bus_id, 1, 2,
 185                                             8 * sizeof (long));
 186         debug_register_view(device->debug_area, &debug_sprintf_view);
 187         debug_set_level(device->debug_area, DBF_WARNING);
 188         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 189
 190         device->state = DASD_STATE_BASIC;
 191         return 0;
 192 }
 193
 194 /*
 195  * Release the irq line for the device. Terminate any running i/o.
 196  */
 197 static int
 198 dasd_state_basic_to_known(struct dasd_device * device)
 199 {
 200         int rc;
 201
 202         dasd_gendisk_free(device);
 203         rc = dasd_flush_ccw_queue(device, 1);
 204         if (rc)
 205                 return rc;
 206         dasd_clear_timer(device);
 207
 208         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
 209         if (device->debug_area != NULL) {
 210                 debug_unregister(device->debug_area);
 211                 device->debug_area = NULL;
 212         }
 213         device->state = DASD_STATE_KNOWN;
 214         return 0;
 215 }
 216
 217 /*
 218  * Do the initial analysis. The do_analysis function may return
 219  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 220  * until the discipline decides to continue the startup sequence
 221  * by calling the function dasd_change_state. The eckd disciplines
 222  * uses this to start a ccw that detects the format. The completion
 223  * interrupt for this detection ccw uses the kernel event daemon to
 224  * trigger the call to dasd_change_state. All this is done in the
 225  * discipline code, see dasd_eckd.c.
 226  * After the analysis ccw is done (do_analysis returned 0) the block
 227  * device is setup.
 228  * In case the analysis returns an error, the device setup is stopped
 229  * (a fake disk was already added to allow formatting).
 230  */
 231 static int
 232 dasd_state_basic_to_ready(struct dasd_device * device)
 233 {
 234         int rc;
 235
 236         rc = 0;
 237         if (device->discipline->do_analysis != NULL)
 238                 rc = device->discipline->do_analysis(device);
 239         if (rc) {
 240                 if (rc != -EAGAIN)
 241                         device->state = DASD_STATE_UNFMT;
 242                 return rc;
 243         }
 244         /* make disk known with correct capacity */
 245         dasd_setup_queue(device);
 246         set_capacity(device->gdp, device->blocks << device->s2b_shift);
 247         device->state = DASD_STATE_READY;
 248         rc = dasd_scan_partitions(device);
 249         if (rc)
 250                 device->state = DASD_STATE_BASIC;
 251         return rc;
 252 }
 253
 254 /*
 255  * Remove device from block device layer. Destroy dirty buffers.
 256  * Forget format information. Check if the target level is basic
 257  * and if it is create fake disk for formatting.
 258  */
 259 static int
 260 dasd_state_ready_to_basic(struct dasd_device * device)
 261 {
 262         int rc;
 263
 264         rc = dasd_flush_ccw_queue(device, 0);
 265         if (rc)
 266                 return rc;
 267         dasd_destroy_partitions(device);
 268         dasd_flush_request_queue(device);
 269         device->blocks = 0;
 270         device->bp_block = 0;
 271         device->s2b_shift = 0;
 272         device->state = DASD_STATE_BASIC;
 273         return 0;
 274 }
 275
 276 /*
 277  * Back to basic.
 278  */
 279 static int
 280 dasd_state_unfmt_to_basic(struct dasd_device * device)
 281 {
 282         device->state = DASD_STATE_BASIC;
 283         return 0;
 284 }
 285
 286 /*
 287  * Make the device online and schedule the bottom half to start
 288  * the requeueing of requests from the linux request queue to the
 289  * ccw queue.
 290  */
 291 static int
 292 dasd_state_ready_to_online(struct dasd_device * device)
 293 {
 294         device->state = DASD_STATE_ONLINE;
 295         dasd_schedule_bh(device);
 296         return 0;
 297 }
 298
 299 /*
 300  * Stop the requeueing of requests again.
 301  */
 302 static int
 303 dasd_state_online_to_ready(struct dasd_device * device)
 304 {
 305         device->state = DASD_STATE_READY;
 306         return 0;
 307 }
 308
 309 /*
 310  * Device startup state changes.
 311  */
 312 static int
 313 dasd_increase_state(struct dasd_device *device)
 314 {
 315         int rc;
 316
 317         rc = 0;
 318         if (device->state == DASD_STATE_NEW &&
 319             device->target >= DASD_STATE_KNOWN)
 320                 rc = dasd_state_new_to_known(device);
 321
 322         if (!rc &&
 323             device->state == DASD_STATE_KNOWN &&
 324             device->target >= DASD_STATE_BASIC)
 325                 rc = dasd_state_known_to_basic(device);
 326
 327         if (!rc &&
 328             device->state == DASD_STATE_BASIC &&
 329             device->target >= DASD_STATE_READY)
 330                 rc = dasd_state_basic_to_ready(device);
 331
 332         if (!rc &&
 333             device->state == DASD_STATE_UNFMT &&
 334             device->target > DASD_STATE_UNFMT)
 335                 rc = -EPERM;
 336
 337         if (!rc &&
 338             device->state == DASD_STATE_READY &&
 339             device->target >= DASD_STATE_ONLINE)
 340                 rc = dasd_state_ready_to_online(device);
 341
 342         return rc;
 343 }
 344
 345 /*
 346  * Device shutdown state changes.
 347  */
 348 static int
 349 dasd_decrease_state(struct dasd_device *device)
 350 {
 351         int rc;
 352
 353         rc = 0;
 354         if (device->state == DASD_STATE_ONLINE &&
 355             device->target <= DASD_STATE_READY)
 356                 rc = dasd_state_online_to_ready(device);
 357
 358         if (!rc &&
 359             device->state == DASD_STATE_READY &&
 360             device->target <= DASD_STATE_BASIC)
 361                 rc = dasd_state_ready_to_basic(device);
 362
 363         if (!rc &&
 364             device->state == DASD_STATE_UNFMT &&
 365             device->target <= DASD_STATE_BASIC)
 366                 rc = dasd_state_unfmt_to_basic(device);
 367
 368         if (!rc &&
 369             device->state == DASD_STATE_BASIC &&
 370             device->target <= DASD_STATE_KNOWN)
 371                 rc = dasd_state_basic_to_known(device);
 372
 373         if (!rc &&
 374             device->state == DASD_STATE_KNOWN &&
 375             device->target <= DASD_STATE_NEW)
 376                 rc = dasd_state_known_to_new(device);
 377
 378         return rc;
 379 }
 380
 381 /*
 382  * This is the main startup/shutdown routine.
 383  */
 384 static void
 385 dasd_change_state(struct dasd_device *device)
 386 {
 387         int rc;
 388
 389         if (device->state == device->target)
 390                 /* Already where we want to go today... */
 391                 return;
 392         if (device->state < device->target)
 393                 rc = dasd_increase_state(device);
 394         else
 395                 rc = dasd_decrease_state(device);
 396         if (rc && rc != -EAGAIN)
 397                 device->target = device->state;
 398
 399         if (device->state == device->target)
 400                 wake_up(&dasd_init_waitq);
 401
 402         /* let user-space know that the device status changed */
 403         kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
 404 }
 405
 406 /*
 407  * Kick starter for devices that did not complete the startup/shutdown
 408  * procedure or were sleeping because of a pending state.
 409  * dasd_kick_device will schedule a call do do_kick_device to the kernel
 410  * event daemon.
 411  */
 412 static void
 413 do_kick_device(struct work_struct *work)
 414 {
 415         struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
 416         dasd_change_state(device);
 417         dasd_schedule_bh(device);
 418         dasd_put_device(device);
 419 }
 420
 421 void
 422 dasd_kick_device(struct dasd_device *device)
 423 {
 424         dasd_get_device(device);
 425         /* queue call to dasd_kick_device to the kernel event daemon. */
 426         schedule_work(&device->kick_work);
 427 }
 428
 429 /*
 430  * Set the target state for a device and starts the state change.
 431  */
 432 void
 433 dasd_set_target_state(struct dasd_device *device, int target)
 434 {
 435         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 436         if (dasd_probeonly && target > DASD_STATE_READY)
 437                 target = DASD_STATE_READY;
 438         if (device->target != target) {
 439                 if (device->state == target)
 440                         wake_up(&dasd_init_waitq);
 441                 device->target = target;
 442         }
 443         if (device->state != device->target)
 444                 dasd_change_state(device);
 445 }
 446
 447 /*
 448  * Enable devices with device numbers in [from..to].
 449  */
 450 static inline int
 451 _wait_for_device(struct dasd_device *device)
 452 {
 453         return (device->state == device->target);
 454 }
 455
 456 void
 457 dasd_enable_device(struct dasd_device *device)
 458 {
 459         dasd_set_target_state(device, DASD_STATE_ONLINE);
 460         if (device->state <= DASD_STATE_KNOWN)
 461                 /* No discipline for device found. */
 462                 dasd_set_target_state(device, DASD_STATE_NEW);
 463         /* Now wait for the devices to come up. */
 464         wait_event(dasd_init_waitq, _wait_for_device(device));
 465 }
 466
 467 /*
 468  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 469  */
 470 #ifdef CONFIG_DASD_PROFILE
 471
 472 struct dasd_profile_info_t dasd_global_profile;
 473 unsigned int dasd_profile_level = DASD_PROFILE_OFF;
 474
 475 /*
 476  * Increments counter in global and local profiling structures.
 477  */
 478 #define dasd_profile_counter(value, counter, device) \
 479 { \
 480         int index; \
 481         for (index = 0; index < 31 && value >> (2+index); index++); \
 482         dasd_global_profile.counter[index]++; \
 483         device->profile.counter[index]++; \
 484 }
 485
 486 /*
 487  * Add profiling information for cqr before execution.
 488  */
 489 static void
 490 dasd_profile_start(struct dasd_device *device, struct dasd_ccw_req * cqr,
 491                    struct request *req)
 492 {
 493         struct list_head *l;
 494         unsigned int counter;
 495
 496         if (dasd_profile_level != DASD_PROFILE_ON)
 497                 return;
 498
 499         /* count the length of the chanq for statistics */
 500         counter = 0;
 501         list_for_each(l, &device->ccw_queue)
 502                 if (++counter >= 31)
 503                         break;
 504         dasd_global_profile.dasd_io_nr_req[counter]++;
 505         device->profile.dasd_io_nr_req[counter]++;
 506 }
 507
 508 /*
 509  * Add profiling information for cqr after execution.
 510  */
 511 static void
 512 dasd_profile_end(struct dasd_device *device, struct dasd_ccw_req * cqr,
 513                  struct request *req)
 514 {
 515         long strtime, irqtime, endtime, tottime;        /* in microseconds */
 516         long tottimeps, sectors;
 517
 518         if (dasd_profile_level != DASD_PROFILE_ON)
 519                 return;
 520
 521         sectors = req->nr_sectors;
 522         if (!cqr->buildclk || !cqr->startclk ||
 523             !cqr->stopclk || !cqr->endclk ||
 524             !sectors)
 525                 return;
 526
 527         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 528         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 529         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 530         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 531         tottimeps = tottime / sectors;
 532
 533         if (!dasd_global_profile.dasd_io_reqs)
 534                 memset(&dasd_global_profile, 0,
 535                        sizeof (struct dasd_profile_info_t));
 536         dasd_global_profile.dasd_io_reqs++;
 537         dasd_global_profile.dasd_io_sects += sectors;
 538
 539         if (!device->profile.dasd_io_reqs)
 540                 memset(&device->profile, 0,
 541                        sizeof (struct dasd_profile_info_t));
 542         device->profile.dasd_io_reqs++;
 543         device->profile.dasd_io_sects += sectors;
 544
 545         dasd_profile_counter(sectors, dasd_io_secs, device);
 546         dasd_profile_counter(tottime, dasd_io_times, device);
 547         dasd_profile_counter(tottimeps, dasd_io_timps, device);
 548         dasd_profile_counter(strtime, dasd_io_time1, device);
 549         dasd_profile_counter(irqtime, dasd_io_time2, device);
 550         dasd_profile_counter(irqtime / sectors, dasd_io_time2ps, device);
 551         dasd_profile_counter(endtime, dasd_io_time3, device);
 552 }
 553 #else
 554 #define dasd_profile_start(device, cqr, req) do {} while (0)
 555 #define dasd_profile_end(device, cqr, req) do {} while (0)
 556 #endif                          /* CONFIG_DASD_PROFILE */
 557
 558 /*
 559  * Allocate memory for a channel program with 'cplength' channel
 560  * command words and 'datasize' additional space. There are two
 561  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
 562  * memory and 2) dasd_smalloc_request uses the static ccw memory
 563  * that gets allocated for each device.
 564  */
 565 struct dasd_ccw_req *
 566 dasd_kmalloc_request(char *magic, int cplength, int datasize,
 567                    struct dasd_device * device)
 568 {
 569         struct dasd_ccw_req *cqr;
 570
 571         /* Sanity checks */
 572         BUG_ON( magic == NULL || datasize > PAGE_SIZE ||
 573              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
 574
 575         cqr = kzalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
 576         if (cqr == NULL)
 577                 return ERR_PTR(-ENOMEM);
 578         cqr->cpaddr = NULL;
 579         if (cplength > 0) {
 580                 cqr->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
 581                                       GFP_ATOMIC | GFP_DMA);
 582                 if (cqr->cpaddr == NULL) {
 583                         kfree(cqr);
 584                         return ERR_PTR(-ENOMEM);
 585                 }
 586         }
 587         cqr->data = NULL;
 588         if (datasize > 0) {
 589                 cqr->data = kzalloc(datasize, GFP_ATOMIC | GFP_DMA);
 590                 if (cqr->data == NULL) {
 591                         kfree(cqr->cpaddr);
 592                         kfree(cqr);
 593                         return ERR_PTR(-ENOMEM);
 594                 }
 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 struct dasd_ccw_req *
 604 dasd_smalloc_request(char *magic, int cplength, int datasize,
 605                    struct dasd_device * device)
 606 {
 607         unsigned long flags;
 608         struct dasd_ccw_req *cqr;
 609         char *data;
 610         int size;
 611
 612         /* Sanity checks */
 613         BUG_ON( magic == NULL || datasize > PAGE_SIZE ||
 614              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
 615
 616         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
 617         if (cplength > 0)
 618                 size += cplength * sizeof(struct ccw1);
 619         if (datasize > 0)
 620                 size += datasize;
 621         spin_lock_irqsave(&device->mem_lock, flags);
 622         cqr = (struct dasd_ccw_req *)
 623                 dasd_alloc_chunk(&device->ccw_chunks, size);
 624         spin_unlock_irqrestore(&device->mem_lock, flags);
 625         if (cqr == NULL)
 626                 return ERR_PTR(-ENOMEM);
 627         memset(cqr, 0, sizeof(struct dasd_ccw_req));
 628         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
 629         cqr->cpaddr = NULL;
 630         if (cplength > 0) {
 631                 cqr->cpaddr = (struct ccw1 *) data;
 632                 data += cplength*sizeof(struct ccw1);
 633                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
 634         }
 635         cqr->data = NULL;
 636         if (datasize > 0) {
 637                 cqr->data = data;
 638                 memset(cqr->data, 0, datasize);
 639         }
 640         strncpy((char *) &cqr->magic, magic, 4);
 641         ASCEBC((char *) &cqr->magic, 4);
 642         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
 643         dasd_get_device(device);
 644         return cqr;
 645 }
 646
 647 /*
 648  * Free memory of a channel program. This function needs to free all the
 649  * idal lists that might have been created by dasd_set_cda and the
 650  * struct dasd_ccw_req itself.
 651  */
 652 void
 653 dasd_kfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
 654 {
 655 #ifdef CONFIG_64BIT
 656         struct ccw1 *ccw;
 657
 658         /* Clear any idals used for the request. */
 659         ccw = cqr->cpaddr;
 660         do {
 661                 clear_normalized_cda(ccw);
 662         } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
 663 #endif
 664         kfree(cqr->cpaddr);
 665         kfree(cqr->data);
 666         kfree(cqr);
 667         dasd_put_device(device);
 668 }
 669
 670 void
 671 dasd_sfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
 672 {
 673         unsigned long flags;
 674
 675         spin_lock_irqsave(&device->mem_lock, flags);
 676         dasd_free_chunk(&device->ccw_chunks, cqr);
 677         spin_unlock_irqrestore(&device->mem_lock, flags);
 678         dasd_put_device(device);
 679 }
 680
 681 /*
 682  * Check discipline magic in cqr.
 683  */
 684 static inline int
 685 dasd_check_cqr(struct dasd_ccw_req *cqr)
 686 {
 687         struct dasd_device *device;
 688
 689         if (cqr == NULL)
 690                 return -EINVAL;
 691         device = cqr->device;
 692         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
 693                 DEV_MESSAGE(KERN_WARNING, device,
 694                             " dasd_ccw_req 0x%08x magic doesn't match"
 695                             " discipline 0x%08x",
 696                             cqr->magic,
 697                             *(unsigned int *) device->discipline->name);
 698                 return -EINVAL;
 699         }
 700         return 0;
 701 }
 702
 703 /*
 704  * Terminate the current i/o and set the request to clear_pending.
 705  * Timer keeps device runnig.
 706  * ccw_device_clear can fail if the i/o subsystem
 707  * is in a bad mood.
 708  */
 709 int
 710 dasd_term_IO(struct dasd_ccw_req * cqr)
 711 {
 712         struct dasd_device *device;
 713         int retries, rc;
 714
 715         /* Check the cqr */
 716         rc = dasd_check_cqr(cqr);
 717         if (rc)
 718                 return rc;
 719         retries = 0;
 720         device = (struct dasd_device *) cqr->device;
 721         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
 722                 rc = ccw_device_clear(device->cdev, (long) cqr);
 723                 switch (rc) {
 724                 case 0: /* termination successful */
 725                         cqr->retries--;
 726                         cqr->status = DASD_CQR_CLEAR;
 727                         cqr->stopclk = get_clock();
 728                         cqr->starttime = 0;
 729                         DBF_DEV_EVENT(DBF_DEBUG, device,
 730                                       "terminate cqr %p successful",
 731                                       cqr);
 732                         break;
 733                 case -ENODEV:
 734                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 735                                       "device gone, retry");
 736                         break;
 737                 case -EIO:
 738                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 739                                       "I/O error, retry");
 740                         break;
 741                 case -EINVAL:
 742                 case -EBUSY:
 743                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 744                                       "device busy, retry later");
 745                         break;
 746                 default:
 747                         DEV_MESSAGE(KERN_ERR, device,
 748                                     "line %d unknown RC=%d, please "
 749                                     "report to linux390@de.ibm.com",
 750                                     __LINE__, rc);
 751                         BUG();
 752                         break;
 753                 }
 754                 retries++;
 755         }
 756         dasd_schedule_bh(device);
 757         return rc;
 758 }
 759
 760 /*
 761  * Start the i/o. This start_IO can fail if the channel is really busy.
 762  * In that case set up a timer to start the request later.
 763  */
 764 int
 765 dasd_start_IO(struct dasd_ccw_req * cqr)
 766 {
 767         struct dasd_device *device;
 768         int rc;
 769
 770         /* Check the cqr */
 771         rc = dasd_check_cqr(cqr);
 772         if (rc)
 773                 return rc;
 774         device = (struct dasd_device *) cqr->device;
 775         if (cqr->retries < 0) {
 776                 DEV_MESSAGE(KERN_DEBUG, device,
 777                             "start_IO: request %p (%02x/%i) - no retry left.",
 778                             cqr, cqr->status, cqr->retries);
 779                 cqr->status = DASD_CQR_FAILED;
 780                 return -EIO;
 781         }
 782         cqr->startclk = get_clock();
 783         cqr->starttime = jiffies;
 784         cqr->retries--;
 785         rc = ccw_device_start(device->cdev, cqr->cpaddr, (long) cqr,
 786                               cqr->lpm, 0);
 787         switch (rc) {
 788         case 0:
 789                 cqr->status = DASD_CQR_IN_IO;
 790                 DBF_DEV_EVENT(DBF_DEBUG, device,
 791                               "start_IO: request %p started successful",
 792                               cqr);
 793                 break;
 794         case -EBUSY:
 795                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 796                               "start_IO: device busy, retry later");
 797                 break;
 798         case -ETIMEDOUT:
 799                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 800                               "start_IO: request timeout, retry later");
 801                 break;
 802         case -EACCES:
 803                 /* -EACCES indicates that the request used only a
 804                  * subset of the available pathes and all these
 805                  * pathes are gone.
 806                  * Do a retry with all available pathes.
 807                  */
 808                 cqr->lpm = LPM_ANYPATH;
 809                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 810                               "start_IO: selected pathes gone,"
 811                               " retry on all pathes");
 812                 break;
 813         case -ENODEV:
 814         case -EIO:
 815                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 816                               "start_IO: device gone, retry");
 817                 break;
 818         default:
 819                 DEV_MESSAGE(KERN_ERR, device,
 820                             "line %d unknown RC=%d, please report"
 821                             " to linux390@de.ibm.com", __LINE__, rc);
 822                 BUG();
 823                 break;
 824         }
 825         return rc;
 826 }
 827
 828 /*
 829  * Timeout function for dasd devices. This is used for different purposes
 830  *  1) missing interrupt handler for normal operation
 831  *  2) delayed start of request where start_IO failed with -EBUSY
 832  *  3) timeout for missing state change interrupts
 833  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
 834  * DASD_CQR_QUEUED for 2) and 3).
 835  */
 836 static void
 837 dasd_timeout_device(unsigned long ptr)
 838 {
 839         unsigned long flags;
 840         struct dasd_device *device;
 841
 842         device = (struct dasd_device *) ptr;
 843         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
 844         /* re-activate request queue */
 845         device->stopped &= ~DASD_STOPPED_PENDING;
 846         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
 847         dasd_schedule_bh(device);
 848 }
 849
 850 /*
 851  * Setup timeout for a device in jiffies.
 852  */
 853 void
 854 dasd_set_timer(struct dasd_device *device, int expires)
 855 {
 856         if (expires == 0) {
 857                 if (timer_pending(&device->timer))
 858                         del_timer(&device->timer);
 859                 return;
 860         }
 861         if (timer_pending(&device->timer)) {
 862                 if (mod_timer(&device->timer, jiffies + expires))
 863                         return;
 864         }
 865         device->timer.function = dasd_timeout_device;
 866         device->timer.data = (unsigned long) device;
 867         device->timer.expires = jiffies + expires;
 868         add_timer(&device->timer);
 869 }
 870
 871 /*
 872  * Clear timeout for a device.
 873  */
 874 void
 875 dasd_clear_timer(struct dasd_device *device)
 876 {
 877         if (timer_pending(&device->timer))
 878                 del_timer(&device->timer);
 879 }
 880
 881 static void
 882 dasd_handle_killed_request(struct ccw_device *cdev, unsigned long intparm)
 883 {
 884         struct dasd_ccw_req *cqr;
 885         struct dasd_device *device;
 886
 887         cqr = (struct dasd_ccw_req *) intparm;
 888         if (cqr->status != DASD_CQR_IN_IO) {
 889                 MESSAGE(KERN_DEBUG,
 890                         "invalid status in handle_killed_request: "
 891                         "bus_id %s, status %02x",
 892                         cdev->dev.bus_id, cqr->status);
 893                 return;
 894         }
 895
 896         device = (struct dasd_device *) cqr->device;
 897         if (device == NULL ||
 898             device != dasd_device_from_cdev_locked(cdev) ||
 899             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
 900                 MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
 901                         cdev->dev.bus_id);
 902                 return;
 903         }
 904
 905         /* Schedule request to be retried. */
 906         cqr->status = DASD_CQR_QUEUED;
 907
 908         dasd_clear_timer(device);
 909         dasd_schedule_bh(device);
 910         dasd_put_device(device);
 911 }
 912
 913 static void
 914 dasd_handle_state_change_pending(struct dasd_device *device)
 915 {
 916         struct dasd_ccw_req *cqr;
 917         struct list_head *l, *n;
 918
 919         /* First of all start sense subsystem status request. */
 920         dasd_eer_snss(device);
 921
 922         device->stopped &= ~DASD_STOPPED_PENDING;
 923
 924         /* restart all 'running' IO on queue */
 925         list_for_each_safe(l, n, &device->ccw_queue) {
 926                 cqr = list_entry(l, struct dasd_ccw_req, list);
 927                 if (cqr->status == DASD_CQR_IN_IO) {
 928                         cqr->status = DASD_CQR_QUEUED;
 929                 }
 930         }
 931         dasd_clear_timer(device);
 932         dasd_schedule_bh(device);
 933 }
 934
 935 /*
 936  * Interrupt handler for "normal" ssch-io based dasd devices.
 937  */
 938 void
 939 dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
 940                  struct irb *irb)
 941 {
 942         struct dasd_ccw_req *cqr, *next;
 943         struct dasd_device *device;
 944         unsigned long long now;
 945         int expires;
 946         dasd_era_t era;
 947         char mask;
 948
 949         if (IS_ERR(irb)) {
 950                 switch (PTR_ERR(irb)) {
 951                 case -EIO:
 952                         dasd_handle_killed_request(cdev, intparm);
 953                         break;
 954                 case -ETIMEDOUT:
 955                         printk(KERN_WARNING"%s(%s): request timed out\n",
 956                                __FUNCTION__, cdev->dev.bus_id);
 957                         //FIXME - dasd uses own timeout interface...
 958                         break;
 959                 default:
 960                         printk(KERN_WARNING"%s(%s): unknown error %ld\n",
 961                                __FUNCTION__, cdev->dev.bus_id, PTR_ERR(irb));
 962                 }
 963                 return;
 964         }
 965
 966         now = get_clock();
 967
 968         DBF_EVENT(DBF_ERR, "Interrupt: bus_id %s CS/DS %04x ip %08x",
 969                   cdev->dev.bus_id, ((irb->scsw.cstat<<8)|irb->scsw.dstat),
 970                   (unsigned int) intparm);
 971
 972         /* first of all check for state change pending interrupt */
 973         mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP;
 974         if ((irb->scsw.dstat & mask) == mask) {
 975                 device = dasd_device_from_cdev_locked(cdev);
 976                 if (!IS_ERR(device)) {
 977                         dasd_handle_state_change_pending(device);
 978                         dasd_put_device(device);
 979                 }
 980                 return;
 981         }
 982
 983         cqr = (struct dasd_ccw_req *) intparm;
 984
 985         /* check for unsolicited interrupts */
 986         if (cqr == NULL) {
 987                 MESSAGE(KERN_DEBUG,
 988                         "unsolicited interrupt received: bus_id %s",
 989                         cdev->dev.bus_id);
 990                 return;
 991         }
 992
 993         device = (struct dasd_device *) cqr->device;
 994         if (device == NULL ||
 995             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
 996                 MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
 997                         cdev->dev.bus_id);
 998                 return;
 999         }
1000
1001         /* Check for clear pending */
1002         if (cqr->status == DASD_CQR_CLEAR &&
1003             irb->scsw.fctl & SCSW_FCTL_CLEAR_FUNC) {
1004                 cqr->status = DASD_CQR_QUEUED;
1005                 dasd_clear_timer(device);
1006                 wake_up(&dasd_flush_wq);
1007                 dasd_schedule_bh(device);
1008                 return;
1009         }
1010
1011         /* check status - the request might have been killed by dyn detach */
1012         if (cqr->status != DASD_CQR_IN_IO) {
1013                 MESSAGE(KERN_DEBUG,
1014                         "invalid status: bus_id %s, status %02x",
1015                         cdev->dev.bus_id, cqr->status);
1016                 return;
1017         }
1018         DBF_DEV_EVENT(DBF_DEBUG, device, "Int: CS/DS 0x%04x for cqr %p",
1019                       ((irb->scsw.cstat << 8) | irb->scsw.dstat), cqr);
1020
1021         /* Find out the appropriate era_action. */
1022         if (irb->scsw.fctl & SCSW_FCTL_HALT_FUNC)
1023                 era = dasd_era_fatal;
1024         else if (irb->scsw.dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1025                  irb->scsw.cstat == 0 &&
1026                  !irb->esw.esw0.erw.cons)
1027                 era = dasd_era_none;
1028         else if (irb->esw.esw0.erw.cons)
1029                 era = device->discipline->examine_error(cqr, irb);
1030         else
1031                 era = dasd_era_recover;
1032
1033         DBF_DEV_EVENT(DBF_DEBUG, device, "era_code %d", era);
1034         expires = 0;
1035         if (era == dasd_era_none) {
1036                 cqr->status = DASD_CQR_DONE;
1037                 cqr->stopclk = now;
1038                 /* Start first request on queue if possible -> fast_io. */
1039                 if (cqr->list.next != &device->ccw_queue) {
1040                         next = list_entry(cqr->list.next,
1041                                           struct dasd_ccw_req, list);
1042                         if ((next->status == DASD_CQR_QUEUED) &&
1043                             (!device->stopped)) {
1044                                 if (device->discipline->start_IO(next) == 0)
1045                                         expires = next->expires;
1046                                 else
1047                                         DEV_MESSAGE(KERN_DEBUG, device, "%s",
1048                                                     "Interrupt fastpath "
1049                                                     "failed!");
1050                         }
1051                 }
1052         } else {                /* error */
1053                 memcpy(&cqr->irb, irb, sizeof (struct irb));
1054                 if (device->features & DASD_FEATURE_ERPLOG) {
1055                         /* dump sense data */
1056                         dasd_log_sense(cqr, irb);
1057                 }
1058                 switch (era) {
1059                 case dasd_era_fatal:
1060                         cqr->status = DASD_CQR_FAILED;
1061                         cqr->stopclk = now;
1062                         break;
1063                 case dasd_era_recover:
1064                         cqr->status = DASD_CQR_ERROR;
1065                         break;
1066                 default:
1067                         BUG();
1068                 }
1069         }
1070         if (expires != 0)
1071                 dasd_set_timer(device, expires);
1072         else
1073                 dasd_clear_timer(device);
1074         dasd_schedule_bh(device);
1075 }
1076
1077 /*
1078  * posts the buffer_cache about a finalized request
1079  */
1080 static inline void
1081 dasd_end_request(struct request *req, int uptodate)
1082 {
1083         if (end_that_request_first(req, uptodate, req->hard_nr_sectors))
1084                 BUG();
1085         add_disk_randomness(req->rq_disk);
1086         end_that_request_last(req, uptodate);
1087 }
1088
1089 /*
1090  * Process finished error recovery ccw.
1091  */
1092 static inline void
1093 __dasd_process_erp(struct dasd_device *device, struct dasd_ccw_req *cqr)
1094 {
1095         dasd_erp_fn_t erp_fn;
1096
1097         if (cqr->status == DASD_CQR_DONE)
1098                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
1099         else
1100                 DEV_MESSAGE(KERN_ERR, device, "%s", "ERP unsuccessful");
1101         erp_fn = device->discipline->erp_postaction(cqr);
1102         erp_fn(cqr);
1103 }
1104
1105 /*
1106  * Process ccw request queue.
1107  */
1108 static void
1109 __dasd_process_ccw_queue(struct dasd_device * device,
1110                          struct list_head *final_queue)
1111 {
1112         struct list_head *l, *n;
1113         struct dasd_ccw_req *cqr;
1114         dasd_erp_fn_t erp_fn;
1115
1116 restart:
1117         /* Process request with final status. */
1118         list_for_each_safe(l, n, &device->ccw_queue) {
1119                 cqr = list_entry(l, struct dasd_ccw_req, list);
1120                 /* Stop list processing at the first non-final request. */
1121                 if (cqr->status != DASD_CQR_DONE &&
1122                     cqr->status != DASD_CQR_FAILED &&
1123                     cqr->status != DASD_CQR_ERROR)
1124                         break;
1125                 /*  Process requests with DASD_CQR_ERROR */
1126                 if (cqr->status == DASD_CQR_ERROR) {
1127                         if (cqr->irb.scsw.fctl & SCSW_FCTL_HALT_FUNC) {
1128                                 cqr->status = DASD_CQR_FAILED;
1129                                 cqr->stopclk = get_clock();
1130                         } else {
1131                                 if (cqr->irb.esw.esw0.erw.cons &&
1132                                     test_bit(DASD_CQR_FLAGS_USE_ERP,
1133                                              &cqr->flags)) {
1134                                         erp_fn = device->discipline->
1135                                                 erp_action(cqr);
1136                                         erp_fn(cqr);
1137                                 } else
1138                                         dasd_default_erp_action(cqr);
1139                         }
1140                         goto restart;
1141                 }
1142
1143                 /* First of all call extended error reporting. */
1144                 if (dasd_eer_enabled(device) &&
1145                     cqr->status == DASD_CQR_FAILED) {
1146                         dasd_eer_write(device, cqr, DASD_EER_FATALERROR);
1147
1148                         /* restart request  */
1149                         cqr->status = DASD_CQR_QUEUED;
1150                         cqr->retries = 255;
1151                         device->stopped |= DASD_STOPPED_QUIESCE;
1152                         goto restart;
1153                 }
1154
1155                 /* Process finished ERP request. */
1156                 if (cqr->refers) {
1157                         __dasd_process_erp(device, cqr);
1158                         goto restart;
1159                 }
1160
1161                 /* Rechain finished requests to final queue */
1162                 cqr->endclk = get_clock();
1163                 list_move_tail(&cqr->list, final_queue);
1164         }
1165 }
1166
1167 static void
1168 dasd_end_request_cb(struct dasd_ccw_req * cqr, void *data)
1169 {
1170         struct request *req;
1171         struct dasd_device *device;
1172         int status;
1173
1174         req = (struct request *) data;
1175         device = cqr->device;
1176         dasd_profile_end(device, cqr, req);
1177         status = cqr->device->discipline->free_cp(cqr,req);
1178         spin_lock_irq(&device->request_queue_lock);
1179         dasd_end_request(req, status);
1180         spin_unlock_irq(&device->request_queue_lock);
1181 }
1182
1183
1184 /*
1185  * Fetch requests from the block device queue.
1186  */
1187 static void
1188 __dasd_process_blk_queue(struct dasd_device * device)
1189 {
1190         request_queue_t *queue;
1191         struct request *req;
1192         struct dasd_ccw_req *cqr;
1193         int nr_queued;
1194
1195         queue = device->request_queue;
1196         /* No queue ? Then there is nothing to do. */
1197         if (queue == NULL)
1198                 return;
1199
1200         /*
1201          * We requeue request from the block device queue to the ccw
1202          * queue only in two states. In state DASD_STATE_READY the
1203          * partition detection is done and we need to requeue requests
1204          * for that. State DASD_STATE_ONLINE is normal block device
1205          * operation.
1206          */
1207         if (device->state != DASD_STATE_READY &&
1208             device->state != DASD_STATE_ONLINE)
1209                 return;
1210         nr_queued = 0;
1211         /* Now we try to fetch requests from the request queue */
1212         list_for_each_entry(cqr, &device->ccw_queue, list)
1213                 if (cqr->status == DASD_CQR_QUEUED)
1214                         nr_queued++;
1215         while (!blk_queue_plugged(queue) &&
1216                elv_next_request(queue) &&
1217                 nr_queued < DASD_CHANQ_MAX_SIZE) {
1218                 req = elv_next_request(queue);
1219
1220                 if (device->features & DASD_FEATURE_READONLY &&
1221                     rq_data_dir(req) == WRITE) {
1222                         DBF_DEV_EVENT(DBF_ERR, device,
1223                                       "Rejecting write request %p",
1224                                       req);
1225                         blkdev_dequeue_request(req);
1226                         dasd_end_request(req, 0);
1227                         continue;
1228                 }
1229                 if (device->stopped & DASD_STOPPED_DC_EIO) {
1230                         blkdev_dequeue_request(req);
1231                         dasd_end_request(req, 0);
1232                         continue;
1233                 }
1234                 cqr = device->discipline->build_cp(device, req);
1235                 if (IS_ERR(cqr)) {
1236                         if (PTR_ERR(cqr) == -ENOMEM)
1237                                 break;  /* terminate request queue loop */
1238                         if (PTR_ERR(cqr) == -EAGAIN) {
1239                                 /*
1240                                  * The current request cannot be build right
1241                                  * now, we have to try later. If this request
1242                                  * is the head-of-queue we stop the device
1243                                  * for 1/2 second.
1244                                  */
1245                                 if (!list_empty(&device->ccw_queue))
1246                                         break;
1247                                 device->stopped |= DASD_STOPPED_PENDING;
1248                                 dasd_set_timer(device, HZ/2);
1249                                 break;
1250                         }
1251                         DBF_DEV_EVENT(DBF_ERR, device,
1252                                       "CCW creation failed (rc=%ld) "
1253                                       "on request %p",
1254                                       PTR_ERR(cqr), req);
1255                         blkdev_dequeue_request(req);
1256                         dasd_end_request(req, 0);
1257                         continue;
1258                 }
1259                 cqr->callback = dasd_end_request_cb;
1260                 cqr->callback_data = (void *) req;
1261                 cqr->status = DASD_CQR_QUEUED;
1262                 blkdev_dequeue_request(req);
1263                 list_add_tail(&cqr->list, &device->ccw_queue);
1264                 dasd_profile_start(device, cqr, req);
1265                 nr_queued++;
1266         }
1267 }
1268
1269 /*
1270  * Take a look at the first request on the ccw queue and check
1271  * if it reached its expire time. If so, terminate the IO.
1272  */
1273 static void
1274 __dasd_check_expire(struct dasd_device * device)
1275 {
1276         struct dasd_ccw_req *cqr;
1277
1278         if (list_empty(&device->ccw_queue))
1279                 return;
1280         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1281         if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1282             (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1283                 if (device->discipline->term_IO(cqr) != 0) {
1284                         /* Hmpf, try again in 5 sec */
1285                         dasd_set_timer(device, 5*HZ);
1286                         DEV_MESSAGE(KERN_ERR, device,
1287                                     "internal error - timeout (%is) expired "
1288                                     "for cqr %p, termination failed, "
1289                                     "retrying in 5s",
1290                                     (cqr->expires/HZ), cqr);
1291                 } else {
1292                         DEV_MESSAGE(KERN_ERR, device,
1293                                     "internal error - timeout (%is) expired "
1294                                     "for cqr %p (%i retries left)",
1295                                     (cqr->expires/HZ), cqr, cqr->retries);
1296                 }
1297         }
1298 }
1299
1300 /*
1301  * Take a look at the first request on the ccw queue and check
1302  * if it needs to be started.
1303  */
1304 static void
1305 __dasd_start_head(struct dasd_device * device)
1306 {
1307         struct dasd_ccw_req *cqr;
1308         int rc;
1309
1310         if (list_empty(&device->ccw_queue))
1311                 return;
1312         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1313         if (cqr->status != DASD_CQR_QUEUED)
1314                 return;
1315         /* Non-temporary stop condition will trigger fail fast */
1316         if (device->stopped & ~DASD_STOPPED_PENDING &&
1317             test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
1318             (!dasd_eer_enabled(device))) {
1319                 cqr->status = DASD_CQR_FAILED;
1320                 dasd_schedule_bh(device);
1321                 return;
1322         }
1323         /* Don't try to start requests if device is stopped */
1324         if (device->stopped)
1325                 return;
1326
1327         rc = device->discipline->start_IO(cqr);
1328         if (rc == 0)
1329                 dasd_set_timer(device, cqr->expires);
1330         else if (rc == -EACCES) {
1331                 dasd_schedule_bh(device);
1332         } else
1333                 /* Hmpf, try again in 1/2 sec */
1334                 dasd_set_timer(device, 50);
1335 }
1336
1337 static inline int
1338 _wait_for_clear(struct dasd_ccw_req *cqr)
1339 {
1340         return (cqr->status == DASD_CQR_QUEUED);
1341 }
1342
1343 /*
1344  * Remove all requests from the ccw queue (all = '1') or only block device
1345  * requests in case all = '0'.
1346  * Take care of the erp-chain (chained via cqr->refers) and remove either
1347  * the whole erp-chain or none of the erp-requests.
1348  * If a request is currently running, term_IO is called and the request
1349  * is re-queued. Prior to removing the terminated request we need to wait
1350  * for the clear-interrupt.
1351  * In case termination is not possible we stop processing and just finishing
1352  * the already moved requests.
1353  */
1354 static int
1355 dasd_flush_ccw_queue(struct dasd_device * device, int all)
1356 {
1357         struct dasd_ccw_req *cqr, *orig, *n;
1358         int rc, i;
1359
1360         struct list_head flush_queue;
1361
1362         INIT_LIST_HEAD(&flush_queue);
1363         spin_lock_irq(get_ccwdev_lock(device->cdev));
1364         rc = 0;
1365 restart:
1366         list_for_each_entry_safe(cqr, n, &device->ccw_queue, list) {
1367                 /* get original request of erp request-chain */
1368                 for (orig = cqr; orig->refers != NULL; orig = orig->refers);
1369
1370                 /* Flush all request or only block device requests? */
1371                 if (all == 0 && cqr->callback != dasd_end_request_cb &&
1372                     orig->callback != dasd_end_request_cb) {
1373                         continue;
1374                 }
1375                 /* Check status and move request to flush_queue */
1376                 switch (cqr->status) {
1377                 case DASD_CQR_IN_IO:
1378                         rc = device->discipline->term_IO(cqr);
1379                         if (rc) {
1380                                 /* unable to terminate requeust */
1381                                 DEV_MESSAGE(KERN_ERR, device,
1382                                             "dasd flush ccw_queue is unable "
1383                                             " to terminate request %p",
1384                                             cqr);
1385                                 /* stop flush processing */
1386                                 goto finished;
1387                         }
1388                         break;
1389                 case DASD_CQR_QUEUED:
1390                 case DASD_CQR_ERROR:
1391                         /* set request to FAILED */
1392                         cqr->stopclk = get_clock();
1393                         cqr->status = DASD_CQR_FAILED;
1394                         break;
1395                 default: /* do not touch the others */
1396                         break;
1397                 }
1398                 /* Rechain request (including erp chain) */
1399                 for (i = 0; cqr != NULL; cqr = cqr->refers, i++) {
1400                         cqr->endclk = get_clock();
1401                         list_move_tail(&cqr->list, &flush_queue);
1402                 }
1403                 if (i > 1)
1404                         /* moved more than one request - need to restart */
1405                         goto restart;
1406         }
1407
1408 finished:
1409         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1410         /* Now call the callback function of flushed requests */
1411 restart_cb:
1412         list_for_each_entry_safe(cqr, n, &flush_queue, list) {
1413                 if (cqr->status == DASD_CQR_CLEAR) {
1414                         /* wait for clear interrupt! */
1415                         wait_event(dasd_flush_wq, _wait_for_clear(cqr));
1416                         cqr->status = DASD_CQR_FAILED;
1417                 }
1418                 /* Process finished ERP request. */
1419                 if (cqr->refers) {
1420                         __dasd_process_erp(device, cqr);
1421                         /* restart list_for_xx loop since dasd_process_erp
1422                          * might remove multiple elements */
1423                         goto restart_cb;
1424                 }
1425                 /* call the callback function */
1426                 cqr->endclk = get_clock();
1427                 if (cqr->callback != NULL)
1428                         (cqr->callback)(cqr, cqr->callback_data);
1429         }
1430         return rc;
1431 }
1432
1433 /*
1434  * Acquire the device lock and process queues for the device.
1435  */
1436 static void
1437 dasd_tasklet(struct dasd_device * device)
1438 {
1439         struct list_head final_queue;
1440         struct list_head *l, *n;
1441         struct dasd_ccw_req *cqr;
1442
1443         atomic_set (&device->tasklet_scheduled, 0);
1444         INIT_LIST_HEAD(&final_queue);
1445         spin_lock_irq(get_ccwdev_lock(device->cdev));
1446         /* Check expire time of first request on the ccw queue. */
1447         __dasd_check_expire(device);
1448         /* Finish off requests on ccw queue */
1449         __dasd_process_ccw_queue(device, &final_queue);
1450         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1451         /* Now call the callback function of requests with final status */
1452         list_for_each_safe(l, n, &final_queue) {
1453                 cqr = list_entry(l, struct dasd_ccw_req, list);
1454                 list_del_init(&cqr->list);
1455                 if (cqr->callback != NULL)
1456                         (cqr->callback)(cqr, cqr->callback_data);
1457         }
1458         spin_lock_irq(&device->request_queue_lock);
1459         spin_lock(get_ccwdev_lock(device->cdev));
1460         /* Get new request from the block device request queue */
1461         __dasd_process_blk_queue(device);
1462         /* Now check if the head of the ccw queue needs to be started. */
1463         __dasd_start_head(device);
1464         spin_unlock(get_ccwdev_lock(device->cdev));
1465         spin_unlock_irq(&device->request_queue_lock);
1466         dasd_put_device(device);
1467 }
1468
1469 /*
1470  * Schedules a call to dasd_tasklet over the device tasklet.
1471  */
1472 void
1473 dasd_schedule_bh(struct dasd_device * device)
1474 {
1475         /* Protect against rescheduling. */
1476         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
1477                 return;
1478         dasd_get_device(device);
1479         tasklet_hi_schedule(&device->tasklet);
1480 }
1481
1482 /*
1483  * Queue a request to the head of the ccw_queue. Start the I/O if
1484  * possible.
1485  */
1486 void
1487 dasd_add_request_head(struct dasd_ccw_req *req)
1488 {
1489         struct dasd_device *device;
1490         unsigned long flags;
1491
1492         device = req->device;
1493         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1494         req->status = DASD_CQR_QUEUED;
1495         req->device = device;
1496         list_add(&req->list, &device->ccw_queue);
1497         /* let the bh start the request to keep them in order */
1498         dasd_schedule_bh(device);
1499         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1500 }
1501
1502 /*
1503  * Queue a request to the tail of the ccw_queue. Start the I/O if
1504  * possible.
1505  */
1506 void
1507 dasd_add_request_tail(struct dasd_ccw_req *req)
1508 {
1509         struct dasd_device *device;
1510         unsigned long flags;
1511
1512         device = req->device;
1513         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1514         req->status = DASD_CQR_QUEUED;
1515         req->device = device;
1516         list_add_tail(&req->list, &device->ccw_queue);
1517         /* let the bh start the request to keep them in order */
1518         dasd_schedule_bh(device);
1519         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1520 }
1521
1522 /*
1523  * Wakeup callback.
1524  */
1525 static void
1526 dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
1527 {
1528         wake_up((wait_queue_head_t *) data);
1529 }
1530
1531 static inline int
1532 _wait_for_wakeup(struct dasd_ccw_req *cqr)
1533 {
1534         struct dasd_device *device;
1535         int rc;
1536
1537         device = cqr->device;
1538         spin_lock_irq(get_ccwdev_lock(device->cdev));
1539         rc = ((cqr->status == DASD_CQR_DONE ||
1540                cqr->status == DASD_CQR_FAILED) &&
1541               list_empty(&cqr->list));
1542         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1543         return rc;
1544 }
1545
1546 /*
1547  * Attempts to start a special ccw queue and waits for its completion.
1548  */
1549 int
1550 dasd_sleep_on(struct dasd_ccw_req * cqr)
1551 {
1552         wait_queue_head_t wait_q;
1553         struct dasd_device *device;
1554         int rc;
1555
1556         device = cqr->device;
1557         spin_lock_irq(get_ccwdev_lock(device->cdev));
1558
1559         init_waitqueue_head (&wait_q);
1560         cqr->callback = dasd_wakeup_cb;
1561         cqr->callback_data = (void *) &wait_q;
1562         cqr->status = DASD_CQR_QUEUED;
1563         list_add_tail(&cqr->list, &device->ccw_queue);
1564
1565         /* let the bh start the request to keep them in order */
1566         dasd_schedule_bh(device);
1567
1568         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1569
1570         wait_event(wait_q, _wait_for_wakeup(cqr));
1571
1572         /* Request status is either done or failed. */
1573         rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1574         return rc;
1575 }
1576
1577 /*
1578  * Attempts to start a special ccw queue and wait interruptible
1579  * for its completion.
1580  */
1581 int
1582 dasd_sleep_on_interruptible(struct dasd_ccw_req * cqr)
1583 {
1584         wait_queue_head_t wait_q;
1585         struct dasd_device *device;
1586         int rc, finished;
1587
1588         device = cqr->device;
1589         spin_lock_irq(get_ccwdev_lock(device->cdev));
1590
1591         init_waitqueue_head (&wait_q);
1592         cqr->callback = dasd_wakeup_cb;
1593         cqr->callback_data = (void *) &wait_q;
1594         cqr->status = DASD_CQR_QUEUED;
1595         list_add_tail(&cqr->list, &device->ccw_queue);
1596
1597         /* let the bh start the request to keep them in order */
1598         dasd_schedule_bh(device);
1599         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1600
1601         finished = 0;
1602         while (!finished) {
1603                 rc = wait_event_interruptible(wait_q, _wait_for_wakeup(cqr));
1604                 if (rc != -ERESTARTSYS) {
1605                         /* Request is final (done or failed) */
1606                         rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO;
1607                         break;
1608                 }
1609                 spin_lock_irq(get_ccwdev_lock(device->cdev));
1610                 switch (cqr->status) {
1611                 case DASD_CQR_IN_IO:
1612                         /* terminate runnig cqr */
1613                         if (device->discipline->term_IO) {
1614                                 cqr->retries = -1;
1615                                 device->discipline->term_IO(cqr);
1616                                 /* wait (non-interruptible) for final status
1617                                  * because signal ist still pending */
1618                                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1619                                 wait_event(wait_q, _wait_for_wakeup(cqr));
1620                                 spin_lock_irq(get_ccwdev_lock(device->cdev));
1621                                 rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO;
1622                                 finished = 1;
1623                         }
1624                         break;
1625                 case DASD_CQR_QUEUED:
1626                         /* request  */
1627                         list_del_init(&cqr->list);
1628                         rc = -EIO;
1629                         finished = 1;
1630                         break;
1631                 default:
1632                         /* cqr with 'non-interruptable' status - just wait */
1633                         break;
1634                 }
1635                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1636         }
1637         return rc;
1638 }
1639
1640 /*
1641  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
1642  * for eckd devices) the currently running request has to be terminated
1643  * and be put back to status queued, before the special request is added
1644  * to the head of the queue. Then the special request is waited on normally.
1645  */
1646 static inline int
1647 _dasd_term_running_cqr(struct dasd_device *device)
1648 {
1649         struct dasd_ccw_req *cqr;
1650
1651         if (list_empty(&device->ccw_queue))
1652                 return 0;
1653         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1654         return device->discipline->term_IO(cqr);
1655 }
1656
1657 int
1658 dasd_sleep_on_immediatly(struct dasd_ccw_req * cqr)
1659 {
1660         wait_queue_head_t wait_q;
1661         struct dasd_device *device;
1662         int rc;
1663
1664         device = cqr->device;
1665         spin_lock_irq(get_ccwdev_lock(device->cdev));
1666         rc = _dasd_term_running_cqr(device);
1667         if (rc) {
1668                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1669                 return rc;
1670         }
1671
1672         init_waitqueue_head (&wait_q);
1673         cqr->callback = dasd_wakeup_cb;
1674         cqr->callback_data = (void *) &wait_q;
1675         cqr->status = DASD_CQR_QUEUED;
1676         list_add(&cqr->list, &device->ccw_queue);
1677
1678         /* let the bh start the request to keep them in order */
1679         dasd_schedule_bh(device);
1680
1681         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1682
1683         wait_event(wait_q, _wait_for_wakeup(cqr));
1684
1685         /* Request status is either done or failed. */
1686         rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1687         return rc;
1688 }
1689
1690 /*
1691  * Cancels a request that was started with dasd_sleep_on_req.
1692  * This is useful to timeout requests. The request will be
1693  * terminated if it is currently in i/o.
1694  * Returns 1 if the request has been terminated.
1695  */
1696 int
1697 dasd_cancel_req(struct dasd_ccw_req *cqr)
1698 {
1699         struct dasd_device *device = cqr->device;
1700         unsigned long flags;
1701         int rc;
1702
1703         rc = 0;
1704         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1705         switch (cqr->status) {
1706         case DASD_CQR_QUEUED:
1707                 /* request was not started - just set to failed */
1708                 cqr->status = DASD_CQR_FAILED;
1709                 break;
1710         case DASD_CQR_IN_IO:
1711                 /* request in IO - terminate IO and release again */
1712                 if (device->discipline->term_IO(cqr) != 0)
1713                         /* what to do if unable to terminate ??????
1714                            e.g. not _IN_IO */
1715                         cqr->status = DASD_CQR_FAILED;
1716                 cqr->stopclk = get_clock();
1717                 rc = 1;
1718                 break;
1719         case DASD_CQR_DONE:
1720         case DASD_CQR_FAILED:
1721                 /* already finished - do nothing */
1722                 break;
1723         default:
1724                 DEV_MESSAGE(KERN_ALERT, device,
1725                             "invalid status %02x in request",
1726                             cqr->status);
1727                 BUG();
1728
1729         }
1730         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1731         dasd_schedule_bh(device);
1732         return rc;
1733 }
1734
1735 /*
1736  * SECTION: Block device operations (request queue, partitions, open, release).
1737  */
1738
1739 /*
1740  * Dasd request queue function. Called from ll_rw_blk.c
1741  */
1742 static void
1743 do_dasd_request(request_queue_t * queue)
1744 {
1745         struct dasd_device *device;
1746
1747         device = (struct dasd_device *) queue->queuedata;
1748         spin_lock(get_ccwdev_lock(device->cdev));
1749         /* Get new request from the block device request queue */
1750         __dasd_process_blk_queue(device);
1751         /* Now check if the head of the ccw queue needs to be started. */
1752         __dasd_start_head(device);
1753         spin_unlock(get_ccwdev_lock(device->cdev));
1754 }
1755
1756 /*
1757  * Allocate and initialize request queue and default I/O scheduler.
1758  */
1759 static int
1760 dasd_alloc_queue(struct dasd_device * device)
1761 {
1762         int rc;
1763
1764         device->request_queue = blk_init_queue(do_dasd_request,
1765                                                &device->request_queue_lock);
1766         if (device->request_queue == NULL)
1767                 return -ENOMEM;
1768
1769         device->request_queue->queuedata = device;
1770
1771         elevator_exit(device->request_queue->elevator);
1772         rc = elevator_init(device->request_queue, "deadline");
1773         if (rc) {
1774                 blk_cleanup_queue(device->request_queue);
1775                 return rc;
1776         }
1777         return 0;
1778 }
1779
1780 /*
1781  * Allocate and initialize request queue.
1782  */
1783 static void
1784 dasd_setup_queue(struct dasd_device * device)
1785 {
1786         int max;
1787
1788         blk_queue_hardsect_size(device->request_queue, device->bp_block);
1789         max = device->discipline->max_blocks << device->s2b_shift;
1790         blk_queue_max_sectors(device->request_queue, max);
1791         blk_queue_max_phys_segments(device->request_queue, -1L);
1792         blk_queue_max_hw_segments(device->request_queue, -1L);
1793         blk_queue_max_segment_size(device->request_queue, -1L);
1794         blk_queue_segment_boundary(device->request_queue, -1L);
1795         blk_queue_ordered(device->request_queue, QUEUE_ORDERED_TAG, NULL);
1796 }
1797
1798 /*
1799  * Deactivate and free request queue.
1800  */
1801 static void
1802 dasd_free_queue(struct dasd_device * device)
1803 {
1804         if (device->request_queue) {
1805                 blk_cleanup_queue(device->request_queue);
1806                 device->request_queue = NULL;
1807         }
1808 }
1809
1810 /*
1811  * Flush request on the request queue.
1812  */
1813 static void
1814 dasd_flush_request_queue(struct dasd_device * device)
1815 {
1816         struct request *req;
1817
1818         if (!device->request_queue)
1819                 return;
1820
1821         spin_lock_irq(&device->request_queue_lock);
1822         while ((req = elv_next_request(device->request_queue))) {
1823                 blkdev_dequeue_request(req);
1824                 dasd_end_request(req, 0);
1825         }
1826         spin_unlock_irq(&device->request_queue_lock);
1827 }
1828
1829 static int
1830 dasd_open(struct inode *inp, struct file *filp)
1831 {
1832         struct gendisk *disk = inp->i_bdev->bd_disk;
1833         struct dasd_device *device = disk->private_data;
1834         int rc;
1835
1836         atomic_inc(&device->open_count);
1837         if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1838                 rc = -ENODEV;
1839                 goto unlock;
1840         }
1841
1842         if (!try_module_get(device->discipline->owner)) {
1843                 rc = -EINVAL;
1844                 goto unlock;
1845         }
1846
1847         if (dasd_probeonly) {
1848                 DEV_MESSAGE(KERN_INFO, device, "%s",
1849                             "No access to device due to probeonly mode");
1850                 rc = -EPERM;
1851                 goto out;
1852         }
1853
1854         if (device->state <= DASD_STATE_BASIC) {
1855                 DBF_DEV_EVENT(DBF_ERR, device, " %s",
1856                               " Cannot open unrecognized device");
1857                 rc = -ENODEV;
1858                 goto out;
1859         }
1860
1861         return 0;
1862
1863 out:
1864         module_put(device->discipline->owner);
1865 unlock:
1866         atomic_dec(&device->open_count);
1867         return rc;
1868 }
1869
1870 static int
1871 dasd_release(struct inode *inp, struct file *filp)
1872 {
1873         struct gendisk *disk = inp->i_bdev->bd_disk;
1874         struct dasd_device *device = disk->private_data;
1875
1876         atomic_dec(&device->open_count);
1877         module_put(device->discipline->owner);
1878         return 0;
1879 }
1880
1881 /*
1882  * Return disk geometry.
1883  */
1884 static int
1885 dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
1886 {
1887         struct dasd_device *device;
1888
1889         device = bdev->bd_disk->private_data;
1890         if (!device)
1891                 return -ENODEV;
1892
1893         if (!device->discipline ||
1894             !device->discipline->fill_geometry)
1895                 return -EINVAL;
1896
1897         device->discipline->fill_geometry(device, geo);
1898         geo->start = get_start_sect(bdev) >> device->s2b_shift;
1899         return 0;
1900 }
1901
1902 struct block_device_operations
1903 dasd_device_operations = {
1904         .owner          = THIS_MODULE,
1905         .open           = dasd_open,
1906         .release        = dasd_release,
1907         .ioctl          = dasd_ioctl,
1908         .compat_ioctl   = dasd_compat_ioctl,
1909         .getgeo         = dasd_getgeo,
1910 };
1911
1912
1913 static void
1914 dasd_exit(void)
1915 {
1916 #ifdef CONFIG_PROC_FS
1917         dasd_proc_exit();
1918 #endif
1919         dasd_eer_exit();
1920         if (dasd_page_cache != NULL) {
1921                 kmem_cache_destroy(dasd_page_cache);
1922                 dasd_page_cache = NULL;
1923         }
1924         dasd_gendisk_exit();
1925         dasd_devmap_exit();
1926         if (dasd_debug_area != NULL) {
1927                 debug_unregister(dasd_debug_area);
1928                 dasd_debug_area = NULL;
1929         }
1930 }
1931
1932 /*
1933  * SECTION: common functions for ccw_driver use
1934  */
1935
1936 /*
1937  * Initial attempt at a probe function. this can be simplified once
1938  * the other detection code is gone.
1939  */
1940 int
1941 dasd_generic_probe (struct ccw_device *cdev,
1942                     struct dasd_discipline *discipline)
1943 {
1944         int ret;
1945
1946         ret = ccw_device_set_options(cdev, CCWDEV_DO_PATHGROUP);
1947         if (ret) {
1948                 printk(KERN_WARNING
1949                        "dasd_generic_probe: could not set ccw-device options "
1950                        "for %s\n", cdev->dev.bus_id);
1951                 return ret;
1952         }
1953         ret = dasd_add_sysfs_files(cdev);
1954         if (ret) {
1955                 printk(KERN_WARNING
1956                        "dasd_generic_probe: could not add sysfs entries "
1957                        "for %s\n", cdev->dev.bus_id);
1958                 return ret;
1959         }
1960         cdev->handler = &dasd_int_handler;
1961
1962         /*
1963          * Automatically online either all dasd devices (dasd_autodetect)
1964          * or all devices specified with dasd= parameters during
1965          * initial probe.
1966          */
1967         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
1968             (dasd_autodetect && dasd_busid_known(cdev->dev.bus_id) != 0))
1969                 ret = ccw_device_set_online(cdev);
1970         if (ret)
1971                 printk(KERN_WARNING
1972                        "dasd_generic_probe: could not initially online "
1973                        "ccw-device %s\n", cdev->dev.bus_id);
1974         return ret;
1975 }
1976
1977 /*
1978  * This will one day be called from a global not_oper handler.
1979  * It is also used by driver_unregister during module unload.
1980  */
1981 void
1982 dasd_generic_remove (struct ccw_device *cdev)
1983 {
1984         struct dasd_device *device;
1985
1986         cdev->handler = NULL;
1987
1988         dasd_remove_sysfs_files(cdev);
1989         device = dasd_device_from_cdev(cdev);
1990         if (IS_ERR(device))
1991                 return;
1992         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1993                 /* Already doing offline processing */
1994                 dasd_put_device(device);
1995                 return;
1996         }
1997         /*
1998          * This device is removed unconditionally. Set offline
1999          * flag to prevent dasd_open from opening it while it is
2000          * no quite down yet.
2001          */
2002         dasd_set_target_state(device, DASD_STATE_NEW);
2003         /* dasd_delete_device destroys the device reference. */
2004         dasd_delete_device(device);
2005 }
2006
2007 /*
2008  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
2009  * the device is detected for the first time and is supposed to be used
2010  * or the user has started activation through sysfs.
2011  */
2012 int
2013 dasd_generic_set_online (struct ccw_device *cdev,
2014                          struct dasd_discipline *base_discipline)
2015
2016 {
2017         struct dasd_discipline *discipline;
2018         struct dasd_device *device;
2019         int rc;
2020
2021         /* first online clears initial online feature flag */
2022         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
2023         device = dasd_create_device(cdev);
2024         if (IS_ERR(device))
2025                 return PTR_ERR(device);
2026
2027         discipline = base_discipline;
2028         if (device->features & DASD_FEATURE_USEDIAG) {
2029                 if (!dasd_diag_discipline_pointer) {
2030                         printk (KERN_WARNING
2031                                 "dasd_generic couldn't online device %s "
2032                                 "- discipline DIAG not available\n",
2033                                 cdev->dev.bus_id);
2034                         dasd_delete_device(device);
2035                         return -ENODEV;
2036                 }
2037                 discipline = dasd_diag_discipline_pointer;
2038         }
2039         if (!try_module_get(base_discipline->owner)) {
2040                 dasd_delete_device(device);
2041                 return -EINVAL;
2042         }
2043         if (!try_module_get(discipline->owner)) {
2044                 module_put(base_discipline->owner);
2045                 dasd_delete_device(device);
2046                 return -EINVAL;
2047         }
2048         device->base_discipline = base_discipline;
2049         device->discipline = discipline;
2050
2051         rc = discipline->check_device(device);
2052         if (rc) {
2053                 printk (KERN_WARNING
2054                         "dasd_generic couldn't online device %s "
2055                         "with discipline %s rc=%i\n",
2056                         cdev->dev.bus_id, discipline->name, rc);
2057                 module_put(discipline->owner);
2058                 module_put(base_discipline->owner);
2059                 dasd_delete_device(device);
2060                 return rc;
2061         }
2062
2063         dasd_set_target_state(device, DASD_STATE_ONLINE);
2064         if (device->state <= DASD_STATE_KNOWN) {
2065                 printk (KERN_WARNING
2066                         "dasd_generic discipline not found for %s\n",
2067                         cdev->dev.bus_id);
2068                 rc = -ENODEV;
2069                 dasd_set_target_state(device, DASD_STATE_NEW);
2070                 dasd_delete_device(device);
2071         } else
2072                 pr_debug("dasd_generic device %s found\n",
2073                                 cdev->dev.bus_id);
2074
2075         /* FIXME: we have to wait for the root device but we don't want
2076          * to wait for each single device but for all at once. */
2077         wait_event(dasd_init_waitq, _wait_for_device(device));
2078
2079         dasd_put_device(device);
2080
2081         return rc;
2082 }
2083
2084 int
2085 dasd_generic_set_offline (struct ccw_device *cdev)
2086 {
2087         struct dasd_device *device;
2088         int max_count, open_count;
2089
2090         device = dasd_device_from_cdev(cdev);
2091         if (IS_ERR(device))
2092                 return PTR_ERR(device);
2093         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
2094                 /* Already doing offline processing */
2095                 dasd_put_device(device);
2096                 return 0;
2097         }
2098         /*
2099          * We must make sure that this device is currently not in use.
2100          * The open_count is increased for every opener, that includes
2101          * the blkdev_get in dasd_scan_partitions. We are only interested
2102          * in the other openers.
2103          */
2104         max_count = device->bdev ? 0 : -1;
2105         open_count = (int) atomic_read(&device->open_count);
2106         if (open_count > max_count) {
2107                 if (open_count > 0)
2108                         printk (KERN_WARNING "Can't offline dasd device with "
2109                                 "open count = %i.\n",
2110                                 open_count);
2111                 else
2112                         printk (KERN_WARNING "%s",
2113                                 "Can't offline dasd device due to internal "
2114                                 "use\n");
2115                 clear_bit(DASD_FLAG_OFFLINE, &device->flags);
2116                 dasd_put_device(device);
2117                 return -EBUSY;
2118         }
2119         dasd_set_target_state(device, DASD_STATE_NEW);
2120         /* dasd_delete_device destroys the device reference. */
2121         dasd_delete_device(device);
2122
2123         return 0;
2124 }
2125
2126 int
2127 dasd_generic_notify(struct ccw_device *cdev, int event)
2128 {
2129         struct dasd_device *device;
2130         struct dasd_ccw_req *cqr;
2131         unsigned long flags;
2132         int ret;
2133
2134         device = dasd_device_from_cdev(cdev);
2135         if (IS_ERR(device))
2136                 return 0;
2137         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
2138         ret = 0;
2139         switch (event) {
2140         case CIO_GONE:
2141         case CIO_NO_PATH:
2142                 /* First of all call extended error reporting. */
2143                 dasd_eer_write(device, NULL, DASD_EER_NOPATH);
2144
2145                 if (device->state < DASD_STATE_BASIC)
2146                         break;
2147                 /* Device is active. We want to keep it. */
2148                 if (test_bit(DASD_FLAG_DSC_ERROR, &device->flags)) {
2149                         list_for_each_entry(cqr, &device->ccw_queue, list)
2150                                 if (cqr->status == DASD_CQR_IN_IO)
2151                                         cqr->status = DASD_CQR_FAILED;
2152                         device->stopped |= DASD_STOPPED_DC_EIO;
2153                 } else {
2154                         list_for_each_entry(cqr, &device->ccw_queue, list)
2155                                 if (cqr->status == DASD_CQR_IN_IO) {
2156                                         cqr->status = DASD_CQR_QUEUED;
2157                                         cqr->retries++;
2158                                 }
2159                         device->stopped |= DASD_STOPPED_DC_WAIT;
2160                         dasd_set_timer(device, 0);
2161                 }
2162                 dasd_schedule_bh(device);
2163                 ret = 1;
2164                 break;
2165         case CIO_OPER:
2166                 /* FIXME: add a sanity check. */
2167                 device->stopped &= ~(DASD_STOPPED_DC_WAIT|DASD_STOPPED_DC_EIO);
2168                 dasd_schedule_bh(device);
2169                 ret = 1;
2170                 break;
2171         }
2172         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
2173         dasd_put_device(device);
2174         return ret;
2175 }
2176
2177 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
2178                                                    void *rdc_buffer,
2179                                                    int rdc_buffer_size,
2180                                                    char *magic)
2181 {
2182         struct dasd_ccw_req *cqr;
2183         struct ccw1 *ccw;
2184
2185         cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device);
2186
2187         if (IS_ERR(cqr)) {
2188                 DEV_MESSAGE(KERN_WARNING, device, "%s",
2189                             "Could not allocate RDC request");
2190                 return cqr;
2191         }
2192
2193         ccw = cqr->cpaddr;
2194         ccw->cmd_code = CCW_CMD_RDC;
2195         ccw->cda = (__u32)(addr_t)rdc_buffer;
2196         ccw->count = rdc_buffer_size;
2197
2198         cqr->device = device;
2199         cqr->expires = 10*HZ;
2200         clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
2201         cqr->retries = 2;
2202         cqr->buildclk = get_clock();
2203         cqr->status = DASD_CQR_FILLED;
2204         return cqr;
2205 }
2206
2207
2208 int dasd_generic_read_dev_chars(struct dasd_device *device, char *magic,
2209                                 void **rdc_buffer, int rdc_buffer_size)
2210 {
2211         int ret;
2212         struct dasd_ccw_req *cqr;
2213
2214         cqr = dasd_generic_build_rdc(device, *rdc_buffer, rdc_buffer_size,
2215                                      magic);
2216         if (IS_ERR(cqr))
2217                 return PTR_ERR(cqr);
2218
2219         ret = dasd_sleep_on(cqr);
2220         dasd_sfree_request(cqr, cqr->device);
2221         return ret;
2222 }
2223 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
2224
2225 static int __init
2226 dasd_init(void)
2227 {
2228         int rc;
2229
2230         init_waitqueue_head(&dasd_init_waitq);
2231         init_waitqueue_head(&dasd_flush_wq);
2232
2233         /* register 'common' DASD debug area, used for all DBF_XXX calls */
2234         dasd_debug_area = debug_register("dasd", 1, 2, 8 * sizeof (long));
2235         if (dasd_debug_area == NULL) {
2236                 rc = -ENOMEM;
2237                 goto failed;
2238         }
2239         debug_register_view(dasd_debug_area, &debug_sprintf_view);
2240         debug_set_level(dasd_debug_area, DBF_WARNING);
2241
2242         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
2243
2244         dasd_diag_discipline_pointer = NULL;
2245
2246         rc = dasd_devmap_init();
2247         if (rc)
2248                 goto failed;
2249         rc = dasd_gendisk_init();
2250         if (rc)
2251                 goto failed;
2252         rc = dasd_parse();
2253         if (rc)
2254                 goto failed;
2255         rc = dasd_eer_init();
2256         if (rc)
2257                 goto failed;
2258 #ifdef CONFIG_PROC_FS
2259         rc = dasd_proc_init();
2260         if (rc)
2261                 goto failed;
2262 #endif
2263
2264         return 0;
2265 failed:
2266         MESSAGE(KERN_INFO, "%s", "initialization not performed due to errors");
2267         dasd_exit();
2268         return rc;
2269 }
2270
2271 module_init(dasd_init);
2272 module_exit(dasd_exit);
2273
2274 EXPORT_SYMBOL(dasd_debug_area);
2275 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
2276
2277 EXPORT_SYMBOL(dasd_add_request_head);
2278 EXPORT_SYMBOL(dasd_add_request_tail);
2279 EXPORT_SYMBOL(dasd_cancel_req);
2280 EXPORT_SYMBOL(dasd_clear_timer);
2281 EXPORT_SYMBOL(dasd_enable_device);
2282 EXPORT_SYMBOL(dasd_int_handler);
2283 EXPORT_SYMBOL(dasd_kfree_request);
2284 EXPORT_SYMBOL(dasd_kick_device);
2285 EXPORT_SYMBOL(dasd_kmalloc_request);
2286 EXPORT_SYMBOL(dasd_schedule_bh);
2287 EXPORT_SYMBOL(dasd_set_target_state);
2288 EXPORT_SYMBOL(dasd_set_timer);
2289 EXPORT_SYMBOL(dasd_sfree_request);
2290 EXPORT_SYMBOL(dasd_sleep_on);
2291 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2292 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2293 EXPORT_SYMBOL(dasd_smalloc_request);
2294 EXPORT_SYMBOL(dasd_start_IO);
2295 EXPORT_SYMBOL(dasd_term_IO);
2296
2297 EXPORT_SYMBOL_GPL(dasd_generic_probe);
2298 EXPORT_SYMBOL_GPL(dasd_generic_remove);
2299 EXPORT_SYMBOL_GPL(dasd_generic_notify);
2300 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
2301 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
2302