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
  41 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
  42 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
  43                    " Copyright 2000 IBM Corporation");
  44 MODULE_SUPPORTED_DEVICE("dasd");
  45 MODULE_LICENSE("GPL");
  46
  47 /*
  48  * SECTION: prototypes for static functions of dasd.c
  49  */
  50 static int  dasd_alloc_queue(struct dasd_device * device);
  51 static void dasd_setup_queue(struct dasd_device * device);
  52 static void dasd_free_queue(struct dasd_device * device);
  53 static void dasd_flush_request_queue(struct dasd_device *);
  54 static void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
  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(void *data);
  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, 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
 403 /*
 404  * Kick starter for devices that did not complete the startup/shutdown
 405  * procedure or were sleeping because of a pending state.
 406  * dasd_kick_device will schedule a call do do_kick_device to the kernel
 407  * event daemon.
 408  */
 409 static void
 410 do_kick_device(void *data)
 411 {
 412         struct dasd_device *device;
 413
 414         device = (struct dasd_device *) data;
 415         dasd_change_state(device);
 416         dasd_schedule_bh(device);
 417         dasd_put_device(device);
 418 }
 419
 420 void
 421 dasd_kick_device(struct dasd_device *device)
 422 {
 423         dasd_get_device(device);
 424         /* queue call to dasd_kick_device to the kernel event daemon. */
 425         schedule_work(&device->kick_work);
 426 }
 427
 428 /*
 429  * Set the target state for a device and starts the state change.
 430  */
 431 void
 432 dasd_set_target_state(struct dasd_device *device, int target)
 433 {
 434         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 435         if (dasd_probeonly && target > DASD_STATE_READY)
 436                 target = DASD_STATE_READY;
 437         if (device->target != target) {
 438                 if (device->state == target)
 439                         wake_up(&dasd_init_waitq);
 440                 device->target = target;
 441         }
 442         if (device->state != device->target)
 443                 dasd_change_state(device);
 444 }
 445
 446 /*
 447  * Enable devices with device numbers in [from..to].
 448  */
 449 static inline int
 450 _wait_for_device(struct dasd_device *device)
 451 {
 452         return (device->state == device->target);
 453 }
 454
 455 void
 456 dasd_enable_device(struct dasd_device *device)
 457 {
 458         dasd_set_target_state(device, DASD_STATE_ONLINE);
 459         if (device->state <= DASD_STATE_KNOWN)
 460                 /* No discipline for device found. */
 461                 dasd_set_target_state(device, DASD_STATE_NEW);
 462         /* Now wait for the devices to come up. */
 463         wait_event(dasd_init_waitq, _wait_for_device(device));
 464 }
 465
 466 /*
 467  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 468  */
 469 #ifdef CONFIG_DASD_PROFILE
 470
 471 struct dasd_profile_info_t dasd_global_profile;
 472 unsigned int dasd_profile_level = DASD_PROFILE_OFF;
 473
 474 /*
 475  * Increments counter in global and local profiling structures.
 476  */
 477 #define dasd_profile_counter(value, counter, device) \
 478 { \
 479         int index; \
 480         for (index = 0; index < 31 && value >> (2+index); index++); \
 481         dasd_global_profile.counter[index]++; \
 482         device->profile.counter[index]++; \
 483 }
 484
 485 /*
 486  * Add profiling information for cqr before execution.
 487  */
 488 static inline void
 489 dasd_profile_start(struct dasd_device *device, struct dasd_ccw_req * cqr,
 490                    struct request *req)
 491 {
 492         struct list_head *l;
 493         unsigned int counter;
 494
 495         if (dasd_profile_level != DASD_PROFILE_ON)
 496                 return;
 497
 498         /* count the length of the chanq for statistics */
 499         counter = 0;
 500         list_for_each(l, &device->ccw_queue)
 501                 if (++counter >= 31)
 502                         break;
 503         dasd_global_profile.dasd_io_nr_req[counter]++;
 504         device->profile.dasd_io_nr_req[counter]++;
 505 }
 506
 507 /*
 508  * Add profiling information for cqr after execution.
 509  */
 510 static inline void
 511 dasd_profile_end(struct dasd_device *device, struct dasd_ccw_req * cqr,
 512                  struct request *req)
 513 {
 514         long strtime, irqtime, endtime, tottime;        /* in microseconds */
 515         long tottimeps, sectors;
 516
 517         if (dasd_profile_level != DASD_PROFILE_ON)
 518                 return;
 519
 520         sectors = req->nr_sectors;
 521         if (!cqr->buildclk || !cqr->startclk ||
 522             !cqr->stopclk || !cqr->endclk ||
 523             !sectors)
 524                 return;
 525
 526         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 527         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 528         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 529         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 530         tottimeps = tottime / sectors;
 531
 532         if (!dasd_global_profile.dasd_io_reqs)
 533                 memset(&dasd_global_profile, 0,
 534                        sizeof (struct dasd_profile_info_t));
 535         dasd_global_profile.dasd_io_reqs++;
 536         dasd_global_profile.dasd_io_sects += sectors;
 537
 538         if (!device->profile.dasd_io_reqs)
 539                 memset(&device->profile, 0,
 540                        sizeof (struct dasd_profile_info_t));
 541         device->profile.dasd_io_reqs++;
 542         device->profile.dasd_io_sects += sectors;
 543
 544         dasd_profile_counter(sectors, dasd_io_secs, device);
 545         dasd_profile_counter(tottime, dasd_io_times, device);
 546         dasd_profile_counter(tottimeps, dasd_io_timps, device);
 547         dasd_profile_counter(strtime, dasd_io_time1, device);
 548         dasd_profile_counter(irqtime, dasd_io_time2, device);
 549         dasd_profile_counter(irqtime / sectors, dasd_io_time2ps, device);
 550         dasd_profile_counter(endtime, dasd_io_time3, device);
 551 }
 552 #else
 553 #define dasd_profile_start(device, cqr, req) do {} while (0)
 554 #define dasd_profile_end(device, cqr, req) do {} while (0)
 555 #endif                          /* CONFIG_DASD_PROFILE */
 556
 557 /*
 558  * Allocate memory for a channel program with 'cplength' channel
 559  * command words and 'datasize' additional space. There are two
 560  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
 561  * memory and 2) dasd_smalloc_request uses the static ccw memory
 562  * that gets allocated for each device.
 563  */
 564 struct dasd_ccw_req *
 565 dasd_kmalloc_request(char *magic, int cplength, int datasize,
 566                    struct dasd_device * device)
 567 {
 568         struct dasd_ccw_req *cqr;
 569
 570         /* Sanity checks */
 571         BUG_ON( magic == NULL || datasize > PAGE_SIZE ||
 572              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
 573
 574         cqr = kzalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
 575         if (cqr == NULL)
 576                 return ERR_PTR(-ENOMEM);
 577         cqr->cpaddr = NULL;
 578         if (cplength > 0) {
 579                 cqr->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
 580                                       GFP_ATOMIC | GFP_DMA);
 581                 if (cqr->cpaddr == NULL) {
 582                         kfree(cqr);
 583                         return ERR_PTR(-ENOMEM);
 584                 }
 585         }
 586         cqr->data = NULL;
 587         if (datasize > 0) {
 588                 cqr->data = kzalloc(datasize, GFP_ATOMIC | GFP_DMA);
 589                 if (cqr->data == NULL) {
 590                         kfree(cqr->cpaddr);
 591                         kfree(cqr);
 592                         return ERR_PTR(-ENOMEM);
 593                 }
 594         }
 595         strncpy((char *) &cqr->magic, magic, 4);
 596         ASCEBC((char *) &cqr->magic, 4);
 597         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
 598         dasd_get_device(device);
 599         return cqr;
 600 }
 601
 602 struct dasd_ccw_req *
 603 dasd_smalloc_request(char *magic, int cplength, int datasize,
 604                    struct dasd_device * device)
 605 {
 606         unsigned long flags;
 607         struct dasd_ccw_req *cqr;
 608         char *data;
 609         int size;
 610
 611         /* Sanity checks */
 612         BUG_ON( magic == NULL || datasize > PAGE_SIZE ||
 613              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
 614
 615         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
 616         if (cplength > 0)
 617                 size += cplength * sizeof(struct ccw1);
 618         if (datasize > 0)
 619                 size += datasize;
 620         spin_lock_irqsave(&device->mem_lock, flags);
 621         cqr = (struct dasd_ccw_req *)
 622                 dasd_alloc_chunk(&device->ccw_chunks, size);
 623         spin_unlock_irqrestore(&device->mem_lock, flags);
 624         if (cqr == NULL)
 625                 return ERR_PTR(-ENOMEM);
 626         memset(cqr, 0, sizeof(struct dasd_ccw_req));
 627         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
 628         cqr->cpaddr = NULL;
 629         if (cplength > 0) {
 630                 cqr->cpaddr = (struct ccw1 *) data;
 631                 data += cplength*sizeof(struct ccw1);
 632                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
 633         }
 634         cqr->data = NULL;
 635         if (datasize > 0) {
 636                 cqr->data = data;
 637                 memset(cqr->data, 0, datasize);
 638         }
 639         strncpy((char *) &cqr->magic, magic, 4);
 640         ASCEBC((char *) &cqr->magic, 4);
 641         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
 642         dasd_get_device(device);
 643         return cqr;
 644 }
 645
 646 /*
 647  * Free memory of a channel program. This function needs to free all the
 648  * idal lists that might have been created by dasd_set_cda and the
 649  * struct dasd_ccw_req itself.
 650  */
 651 void
 652 dasd_kfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
 653 {
 654 #ifdef CONFIG_64BIT
 655         struct ccw1 *ccw;
 656
 657         /* Clear any idals used for the request. */
 658         ccw = cqr->cpaddr;
 659         do {
 660                 clear_normalized_cda(ccw);
 661         } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
 662 #endif
 663         kfree(cqr->cpaddr);
 664         kfree(cqr->data);
 665         kfree(cqr);
 666         dasd_put_device(device);
 667 }
 668
 669 void
 670 dasd_sfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
 671 {
 672         unsigned long flags;
 673
 674         spin_lock_irqsave(&device->mem_lock, flags);
 675         dasd_free_chunk(&device->ccw_chunks, cqr);
 676         spin_unlock_irqrestore(&device->mem_lock, flags);
 677         dasd_put_device(device);
 678 }
 679
 680 /*
 681  * Check discipline magic in cqr.
 682  */
 683 static inline int
 684 dasd_check_cqr(struct dasd_ccw_req *cqr)
 685 {
 686         struct dasd_device *device;
 687
 688         if (cqr == NULL)
 689                 return -EINVAL;
 690         device = cqr->device;
 691         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
 692                 DEV_MESSAGE(KERN_WARNING, device,
 693                             " dasd_ccw_req 0x%08x magic doesn't match"
 694                             " discipline 0x%08x",
 695                             cqr->magic,
 696                             *(unsigned int *) device->discipline->name);
 697                 return -EINVAL;
 698         }
 699         return 0;
 700 }
 701
 702 /*
 703  * Terminate the current i/o and set the request to clear_pending.
 704  * Timer keeps device runnig.
 705  * ccw_device_clear can fail if the i/o subsystem
 706  * is in a bad mood.
 707  */
 708 int
 709 dasd_term_IO(struct dasd_ccw_req * cqr)
 710 {
 711         struct dasd_device *device;
 712         int retries, rc;
 713
 714         /* Check the cqr */
 715         rc = dasd_check_cqr(cqr);
 716         if (rc)
 717                 return rc;
 718         retries = 0;
 719         device = (struct dasd_device *) cqr->device;
 720         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
 721                 rc = ccw_device_clear(device->cdev, (long) cqr);
 722                 switch (rc) {
 723                 case 0: /* termination successful */
 724                         cqr->retries--;
 725                         cqr->status = DASD_CQR_CLEAR;
 726                         cqr->stopclk = get_clock();
 727                         cqr->starttime = 0;
 728                         DBF_DEV_EVENT(DBF_DEBUG, device,
 729                                       "terminate cqr %p successful",
 730                                       cqr);
 731                         break;
 732                 case -ENODEV:
 733                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 734                                       "device gone, retry");
 735                         break;
 736                 case -EIO:
 737                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 738                                       "I/O error, retry");
 739                         break;
 740                 case -EINVAL:
 741                 case -EBUSY:
 742                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 743                                       "device busy, retry later");
 744                         break;
 745                 default:
 746                         DEV_MESSAGE(KERN_ERR, device,
 747                                     "line %d unknown RC=%d, please "
 748                                     "report to linux390@de.ibm.com",
 749                                     __LINE__, rc);
 750                         BUG();
 751                         break;
 752                 }
 753                 retries++;
 754         }
 755         dasd_schedule_bh(device);
 756         return rc;
 757 }
 758
 759 /*
 760  * Start the i/o. This start_IO can fail if the channel is really busy.
 761  * In that case set up a timer to start the request later.
 762  */
 763 int
 764 dasd_start_IO(struct dasd_ccw_req * cqr)
 765 {
 766         struct dasd_device *device;
 767         int rc;
 768
 769         /* Check the cqr */
 770         rc = dasd_check_cqr(cqr);
 771         if (rc)
 772                 return rc;
 773         device = (struct dasd_device *) cqr->device;
 774         if (cqr->retries < 0) {
 775                 DEV_MESSAGE(KERN_DEBUG, device,
 776                             "start_IO: request %p (%02x/%i) - no retry left.",
 777                             cqr, cqr->status, cqr->retries);
 778                 cqr->status = DASD_CQR_FAILED;
 779                 return -EIO;
 780         }
 781         cqr->startclk = get_clock();
 782         cqr->starttime = jiffies;
 783         cqr->retries--;
 784         rc = ccw_device_start(device->cdev, cqr->cpaddr, (long) cqr,
 785                               cqr->lpm, 0);
 786         switch (rc) {
 787         case 0:
 788                 cqr->status = DASD_CQR_IN_IO;
 789                 DBF_DEV_EVENT(DBF_DEBUG, device,
 790                               "start_IO: request %p started successful",
 791                               cqr);
 792                 break;
 793         case -EBUSY:
 794                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 795                               "start_IO: device busy, retry later");
 796                 break;
 797         case -ETIMEDOUT:
 798                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 799                               "start_IO: request timeout, retry later");
 800                 break;
 801         case -EACCES:
 802                 /* -EACCES indicates that the request used only a
 803                  * subset of the available pathes and all these
 804                  * pathes are gone.
 805                  * Do a retry with all available pathes.
 806                  */
 807                 cqr->lpm = LPM_ANYPATH;
 808                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 809                               "start_IO: selected pathes gone,"
 810                               " retry on all pathes");
 811                 break;
 812         case -ENODEV:
 813         case -EIO:
 814                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
 815                               "start_IO: device gone, retry");
 816                 break;
 817         default:
 818                 DEV_MESSAGE(KERN_ERR, device,
 819                             "line %d unknown RC=%d, please report"
 820                             " to linux390@de.ibm.com", __LINE__, rc);
 821                 BUG();
 822                 break;
 823         }
 824         return rc;
 825 }
 826
 827 /*
 828  * Timeout function for dasd devices. This is used for different purposes
 829  *  1) missing interrupt handler for normal operation
 830  *  2) delayed start of request where start_IO failed with -EBUSY
 831  *  3) timeout for missing state change interrupts
 832  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
 833  * DASD_CQR_QUEUED for 2) and 3).
 834  */
 835 static void
 836 dasd_timeout_device(unsigned long ptr)
 837 {
 838         unsigned long flags;
 839         struct dasd_device *device;
 840
 841         device = (struct dasd_device *) ptr;
 842         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
 843         /* re-activate request queue */
 844         device->stopped &= ~DASD_STOPPED_PENDING;
 845         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
 846         dasd_schedule_bh(device);
 847 }
 848
 849 /*
 850  * Setup timeout for a device in jiffies.
 851  */
 852 void
 853 dasd_set_timer(struct dasd_device *device, int expires)
 854 {
 855         if (expires == 0) {
 856                 if (timer_pending(&device->timer))
 857                         del_timer(&device->timer);
 858                 return;
 859         }
 860         if (timer_pending(&device->timer)) {
 861                 if (mod_timer(&device->timer, jiffies + expires))
 862                         return;
 863         }
 864         device->timer.function = dasd_timeout_device;
 865         device->timer.data = (unsigned long) device;
 866         device->timer.expires = jiffies + expires;
 867         add_timer(&device->timer);
 868 }
 869
 870 /*
 871  * Clear timeout for a device.
 872  */
 873 void
 874 dasd_clear_timer(struct dasd_device *device)
 875 {
 876         if (timer_pending(&device->timer))
 877                 del_timer(&device->timer);
 878 }
 879
 880 static void
 881 dasd_handle_killed_request(struct ccw_device *cdev, unsigned long intparm)
 882 {
 883         struct dasd_ccw_req *cqr;
 884         struct dasd_device *device;
 885
 886         cqr = (struct dasd_ccw_req *) intparm;
 887         if (cqr->status != DASD_CQR_IN_IO) {
 888                 MESSAGE(KERN_DEBUG,
 889                         "invalid status in handle_killed_request: "
 890                         "bus_id %s, status %02x",
 891                         cdev->dev.bus_id, cqr->status);
 892                 return;
 893         }
 894
 895         device = (struct dasd_device *) cqr->device;
 896         if (device == NULL ||
 897             device != dasd_device_from_cdev_locked(cdev) ||
 898             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
 899                 MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
 900                         cdev->dev.bus_id);
 901                 return;
 902         }
 903
 904         /* Schedule request to be retried. */
 905         cqr->status = DASD_CQR_QUEUED;
 906
 907         dasd_clear_timer(device);
 908         dasd_schedule_bh(device);
 909         dasd_put_device(device);
 910 }
 911
 912 static void
 913 dasd_handle_state_change_pending(struct dasd_device *device)
 914 {
 915         struct dasd_ccw_req *cqr;
 916         struct list_head *l, *n;
 917
 918         /* First of all start sense subsystem status request. */
 919         dasd_eer_snss(device);
 920
 921         device->stopped &= ~DASD_STOPPED_PENDING;
 922
 923         /* restart all 'running' IO on queue */
 924         list_for_each_safe(l, n, &device->ccw_queue) {
 925                 cqr = list_entry(l, struct dasd_ccw_req, list);
 926                 if (cqr->status == DASD_CQR_IN_IO) {
 927                         cqr->status = DASD_CQR_QUEUED;
 928                 }
 929         }
 930         dasd_clear_timer(device);
 931         dasd_schedule_bh(device);
 932 }
 933
 934 /*
 935  * Interrupt handler for "normal" ssch-io based dasd devices.
 936  */
 937 void
 938 dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
 939                  struct irb *irb)
 940 {
 941         struct dasd_ccw_req *cqr, *next;
 942         struct dasd_device *device;
 943         unsigned long long now;
 944         int expires;
 945         dasd_era_t era;
 946         char mask;
 947
 948         if (IS_ERR(irb)) {
 949                 switch (PTR_ERR(irb)) {
 950                 case -EIO:
 951                         dasd_handle_killed_request(cdev, intparm);
 952                         break;
 953                 case -ETIMEDOUT:
 954                         printk(KERN_WARNING"%s(%s): request timed out\n",
 955                                __FUNCTION__, cdev->dev.bus_id);
 956                         //FIXME - dasd uses own timeout interface...
 957                         break;
 958                 default:
 959                         printk(KERN_WARNING"%s(%s): unknown error %ld\n",
 960                                __FUNCTION__, cdev->dev.bus_id, PTR_ERR(irb));
 961                 }
 962                 return;
 963         }
 964
 965         now = get_clock();
 966
 967         DBF_EVENT(DBF_ERR, "Interrupt: bus_id %s CS/DS %04x ip %08x",
 968                   cdev->dev.bus_id, ((irb->scsw.cstat<<8)|irb->scsw.dstat),
 969                   (unsigned int) intparm);
 970
 971         /* first of all check for state change pending interrupt */
 972         mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP;
 973         if ((irb->scsw.dstat & mask) == mask) {
 974                 device = dasd_device_from_cdev_locked(cdev);
 975                 if (!IS_ERR(device)) {
 976                         dasd_handle_state_change_pending(device);
 977                         dasd_put_device(device);
 978                 }
 979                 return;
 980         }
 981
 982         cqr = (struct dasd_ccw_req *) intparm;
 983
 984         /* check for unsolicited interrupts */
 985         if (cqr == NULL) {
 986                 MESSAGE(KERN_DEBUG,
 987                         "unsolicited interrupt received: bus_id %s",
 988                         cdev->dev.bus_id);
 989                 return;
 990         }
 991
 992         device = (struct dasd_device *) cqr->device;
 993         if (device == NULL ||
 994             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
 995                 MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
 996                         cdev->dev.bus_id);
 997                 return;
 998         }
 999
1000         /* Check for clear pending */
1001         if (cqr->status == DASD_CQR_CLEAR &&
1002             irb->scsw.fctl & SCSW_FCTL_CLEAR_FUNC) {
1003                 cqr->status = DASD_CQR_QUEUED;
1004                 dasd_clear_timer(device);
1005                 wake_up(&dasd_flush_wq);
1006                 dasd_schedule_bh(device);
1007                 return;
1008         }
1009
1010         /* check status - the request might have been killed by dyn detach */
1011         if (cqr->status != DASD_CQR_IN_IO) {
1012                 MESSAGE(KERN_DEBUG,
1013                         "invalid status: bus_id %s, status %02x",
1014                         cdev->dev.bus_id, cqr->status);
1015                 return;
1016         }
1017         DBF_DEV_EVENT(DBF_DEBUG, device, "Int: CS/DS 0x%04x for cqr %p",
1018                       ((irb->scsw.cstat << 8) | irb->scsw.dstat), cqr);
1019
1020         /* Find out the appropriate era_action. */
1021         if (irb->scsw.fctl & SCSW_FCTL_HALT_FUNC)
1022                 era = dasd_era_fatal;
1023         else if (irb->scsw.dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1024                  irb->scsw.cstat == 0 &&
1025                  !irb->esw.esw0.erw.cons)
1026                 era = dasd_era_none;
1027         else if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags))
1028                 era = dasd_era_fatal; /* don't recover this request */
1029         else if (irb->esw.esw0.erw.cons)
1030                 era = device->discipline->examine_error(cqr, irb);
1031         else
1032                 era = dasd_era_recover;
1033
1034         DBF_DEV_EVENT(DBF_DEBUG, device, "era_code %d", era);
1035         expires = 0;
1036         if (era == dasd_era_none) {
1037                 cqr->status = DASD_CQR_DONE;
1038                 cqr->stopclk = now;
1039                 /* Start first request on queue if possible -> fast_io. */
1040                 if (cqr->list.next != &device->ccw_queue) {
1041                         next = list_entry(cqr->list.next,
1042                                           struct dasd_ccw_req, list);
1043                         if ((next->status == DASD_CQR_QUEUED) &&
1044                             (!device->stopped)) {
1045                                 if (device->discipline->start_IO(next) == 0)
1046                                         expires = next->expires;
1047                                 else
1048                                         DEV_MESSAGE(KERN_DEBUG, device, "%s",
1049                                                     "Interrupt fastpath "
1050                                                     "failed!");
1051                         }
1052                 }
1053         } else {                /* error */
1054                 memcpy(&cqr->irb, irb, sizeof (struct irb));
1055 #ifdef ERP_DEBUG
1056                 /* dump sense data */
1057                 dasd_log_sense(cqr, irb);
1058 #endif
1059                 switch (era) {
1060                 case dasd_era_fatal:
1061                         cqr->status = DASD_CQR_FAILED;
1062                         cqr->stopclk = now;
1063                         break;
1064                 case dasd_era_recover:
1065                         cqr->status = DASD_CQR_ERROR;
1066                         break;
1067                 default:
1068                         BUG();
1069                 }
1070         }
1071         if (expires != 0)
1072                 dasd_set_timer(device, expires);
1073         else
1074                 dasd_clear_timer(device);
1075         dasd_schedule_bh(device);
1076 }
1077
1078 /*
1079  * posts the buffer_cache about a finalized request
1080  */
1081 static inline void
1082 dasd_end_request(struct request *req, int uptodate)
1083 {
1084         if (end_that_request_first(req, uptodate, req->hard_nr_sectors))
1085                 BUG();
1086         add_disk_randomness(req->rq_disk);
1087         end_that_request_last(req, uptodate);
1088 }
1089
1090 /*
1091  * Process finished error recovery ccw.
1092  */
1093 static inline void
1094 __dasd_process_erp(struct dasd_device *device, struct dasd_ccw_req *cqr)
1095 {
1096         dasd_erp_fn_t erp_fn;
1097
1098         if (cqr->status == DASD_CQR_DONE)
1099                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
1100         else
1101                 DEV_MESSAGE(KERN_ERR, device, "%s", "ERP unsuccessful");
1102         erp_fn = device->discipline->erp_postaction(cqr);
1103         erp_fn(cqr);
1104 }
1105
1106 /*
1107  * Process ccw request queue.
1108  */
1109 static inline void
1110 __dasd_process_ccw_queue(struct dasd_device * device,
1111                          struct list_head *final_queue)
1112 {
1113         struct list_head *l, *n;
1114         struct dasd_ccw_req *cqr;
1115         dasd_erp_fn_t erp_fn;
1116
1117 restart:
1118         /* Process request with final status. */
1119         list_for_each_safe(l, n, &device->ccw_queue) {
1120                 cqr = list_entry(l, struct dasd_ccw_req, list);
1121                 /* Stop list processing at the first non-final request. */
1122                 if (cqr->status != DASD_CQR_DONE &&
1123                     cqr->status != DASD_CQR_FAILED &&
1124                     cqr->status != DASD_CQR_ERROR)
1125                         break;
1126                 /*  Process requests with DASD_CQR_ERROR */
1127                 if (cqr->status == DASD_CQR_ERROR) {
1128                         if (cqr->irb.scsw.fctl & SCSW_FCTL_HALT_FUNC) {
1129                                 cqr->status = DASD_CQR_FAILED;
1130                                 cqr->stopclk = get_clock();
1131                         } else {
1132                                 if (cqr->irb.esw.esw0.erw.cons) {
1133                                         erp_fn = device->discipline->
1134                                                 erp_action(cqr);
1135                                         erp_fn(cqr);
1136                                 } else
1137                                         dasd_default_erp_action(cqr);
1138                         }
1139                         goto restart;
1140                 }
1141
1142                 /* First of all call extended error reporting. */
1143                 if (dasd_eer_enabled(device) &&
1144                     cqr->status == DASD_CQR_FAILED) {
1145                         dasd_eer_write(device, cqr, DASD_EER_FATALERROR);
1146
1147                         /* restart request  */
1148                         cqr->status = DASD_CQR_QUEUED;
1149                         cqr->retries = 255;
1150                         device->stopped |= DASD_STOPPED_QUIESCE;
1151                         goto restart;
1152                 }
1153
1154                 /* Process finished ERP request. */
1155                 if (cqr->refers) {
1156                         __dasd_process_erp(device, cqr);
1157                         goto restart;
1158                 }
1159
1160                 /* Rechain finished requests to final queue */
1161                 cqr->endclk = get_clock();
1162                 list_move_tail(&cqr->list, final_queue);
1163         }
1164 }
1165
1166 static void
1167 dasd_end_request_cb(struct dasd_ccw_req * cqr, void *data)
1168 {
1169         struct request *req;
1170         struct dasd_device *device;
1171         int status;
1172
1173         req = (struct request *) data;
1174         device = cqr->device;
1175         dasd_profile_end(device, cqr, req);
1176         status = cqr->device->discipline->free_cp(cqr,req);
1177         spin_lock_irq(&device->request_queue_lock);
1178         dasd_end_request(req, status);
1179         spin_unlock_irq(&device->request_queue_lock);
1180 }
1181
1182
1183 /*
1184  * Fetch requests from the block device queue.
1185  */
1186 static inline void
1187 __dasd_process_blk_queue(struct dasd_device * device)
1188 {
1189         request_queue_t *queue;
1190         struct request *req;
1191         struct dasd_ccw_req *cqr;
1192         int nr_queued;
1193
1194         queue = device->request_queue;
1195         /* No queue ? Then there is nothing to do. */
1196         if (queue == NULL)
1197                 return;
1198
1199         /*
1200          * We requeue request from the block device queue to the ccw
1201          * queue only in two states. In state DASD_STATE_READY the
1202          * partition detection is done and we need to requeue requests
1203          * for that. State DASD_STATE_ONLINE is normal block device
1204          * operation.
1205          */
1206         if (device->state != DASD_STATE_READY &&
1207             device->state != DASD_STATE_ONLINE)
1208                 return;
1209         nr_queued = 0;
1210         /* Now we try to fetch requests from the request queue */
1211         list_for_each_entry(cqr, &device->ccw_queue, list)
1212                 if (cqr->status == DASD_CQR_QUEUED)
1213                         nr_queued++;
1214         while (!blk_queue_plugged(queue) &&
1215                elv_next_request(queue) &&
1216                 nr_queued < DASD_CHANQ_MAX_SIZE) {
1217                 req = elv_next_request(queue);
1218
1219                 if (device->features & DASD_FEATURE_READONLY &&
1220                     rq_data_dir(req) == WRITE) {
1221                         DBF_DEV_EVENT(DBF_ERR, device,
1222                                       "Rejecting write request %p",
1223                                       req);
1224                         blkdev_dequeue_request(req);
1225                         dasd_end_request(req, 0);
1226                         continue;
1227                 }
1228                 if (device->stopped & DASD_STOPPED_DC_EIO) {
1229                         blkdev_dequeue_request(req);
1230                         dasd_end_request(req, 0);
1231                         continue;
1232                 }
1233                 cqr = device->discipline->build_cp(device, req);
1234                 if (IS_ERR(cqr)) {
1235                         if (PTR_ERR(cqr) == -ENOMEM)
1236                                 break;  /* terminate request queue loop */
1237                         DBF_DEV_EVENT(DBF_ERR, device,
1238                                       "CCW creation failed (rc=%ld) "
1239                                       "on request %p",
1240                                       PTR_ERR(cqr), req);
1241                         blkdev_dequeue_request(req);
1242                         dasd_end_request(req, 0);
1243                         continue;
1244                 }
1245                 cqr->callback = dasd_end_request_cb;
1246                 cqr->callback_data = (void *) req;
1247                 cqr->status = DASD_CQR_QUEUED;
1248                 blkdev_dequeue_request(req);
1249                 list_add_tail(&cqr->list, &device->ccw_queue);
1250                 dasd_profile_start(device, cqr, req);
1251                 nr_queued++;
1252         }
1253 }
1254
1255 /*
1256  * Take a look at the first request on the ccw queue and check
1257  * if it reached its expire time. If so, terminate the IO.
1258  */
1259 static inline void
1260 __dasd_check_expire(struct dasd_device * device)
1261 {
1262         struct dasd_ccw_req *cqr;
1263
1264         if (list_empty(&device->ccw_queue))
1265                 return;
1266         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1267         if (cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) {
1268                 if (time_after_eq(jiffies, cqr->expires + cqr->starttime)) {
1269                         DEV_MESSAGE(KERN_ERR, device,
1270                                     "internal error - timeout (%is) expired "
1271                                     "for cqr %p (%i retries left)",
1272                                     (cqr->expires/HZ), cqr, cqr->retries);
1273                         if (device->discipline->term_IO(cqr) != 0)
1274                                 /* Hmpf, try again in 1/10 sec */
1275                                 dasd_set_timer(device, 10);
1276                 }
1277         }
1278 }
1279
1280 /*
1281  * Take a look at the first request on the ccw queue and check
1282  * if it needs to be started.
1283  */
1284 static inline void
1285 __dasd_start_head(struct dasd_device * device)
1286 {
1287         struct dasd_ccw_req *cqr;
1288         int rc;
1289
1290         if (list_empty(&device->ccw_queue))
1291                 return;
1292         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1293         if (cqr->status != DASD_CQR_QUEUED)
1294                 return;
1295         /* Non-temporary stop condition will trigger fail fast */
1296         if (device->stopped & ~DASD_STOPPED_PENDING &&
1297             test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
1298             (!dasd_eer_enabled(device))) {
1299                 cqr->status = DASD_CQR_FAILED;
1300                 dasd_schedule_bh(device);
1301                 return;
1302         }
1303         /* Don't try to start requests if device is stopped */
1304         if (device->stopped)
1305                 return;
1306
1307         rc = device->discipline->start_IO(cqr);
1308         if (rc == 0)
1309                 dasd_set_timer(device, cqr->expires);
1310         else if (rc == -EACCES) {
1311                 dasd_schedule_bh(device);
1312         } else
1313                 /* Hmpf, try again in 1/2 sec */
1314                 dasd_set_timer(device, 50);
1315 }
1316
1317 static inline int
1318 _wait_for_clear(struct dasd_ccw_req *cqr)
1319 {
1320         return (cqr->status == DASD_CQR_QUEUED);
1321 }
1322
1323 /*
1324  * Remove all requests from the ccw queue (all = '1') or only block device
1325  * requests in case all = '0'.
1326  * Take care of the erp-chain (chained via cqr->refers) and remove either
1327  * the whole erp-chain or none of the erp-requests.
1328  * If a request is currently running, term_IO is called and the request
1329  * is re-queued. Prior to removing the terminated request we need to wait
1330  * for the clear-interrupt.
1331  * In case termination is not possible we stop processing and just finishing
1332  * the already moved requests.
1333  */
1334 static int
1335 dasd_flush_ccw_queue(struct dasd_device * device, int all)
1336 {
1337         struct dasd_ccw_req *cqr, *orig, *n;
1338         int rc, i;
1339
1340         struct list_head flush_queue;
1341
1342         INIT_LIST_HEAD(&flush_queue);
1343         spin_lock_irq(get_ccwdev_lock(device->cdev));
1344         rc = 0;
1345 restart:
1346         list_for_each_entry_safe(cqr, n, &device->ccw_queue, list) {
1347                 /* get original request of erp request-chain */
1348                 for (orig = cqr; orig->refers != NULL; orig = orig->refers);
1349
1350                 /* Flush all request or only block device requests? */
1351                 if (all == 0 && cqr->callback != dasd_end_request_cb &&
1352                     orig->callback != dasd_end_request_cb) {
1353                         continue;
1354                 }
1355                 /* Check status and move request to flush_queue */
1356                 switch (cqr->status) {
1357                 case DASD_CQR_IN_IO:
1358                         rc = device->discipline->term_IO(cqr);
1359                         if (rc) {
1360                                 /* unable to terminate requeust */
1361                                 DEV_MESSAGE(KERN_ERR, device,
1362                                             "dasd flush ccw_queue is unable "
1363                                             " to terminate request %p",
1364                                             cqr);
1365                                 /* stop flush processing */
1366                                 goto finished;
1367                         }
1368                         break;
1369                 case DASD_CQR_QUEUED:
1370                 case DASD_CQR_ERROR:
1371                         /* set request to FAILED */
1372                         cqr->stopclk = get_clock();
1373                         cqr->status = DASD_CQR_FAILED;
1374                         break;
1375                 default: /* do not touch the others */
1376                         break;
1377                 }
1378                 /* Rechain request (including erp chain) */
1379                 for (i = 0; cqr != NULL; cqr = cqr->refers, i++) {
1380                         cqr->endclk = get_clock();
1381                         list_move_tail(&cqr->list, &flush_queue);
1382                 }
1383                 if (i > 1)
1384                         /* moved more than one request - need to restart */
1385                         goto restart;
1386         }
1387
1388 finished:
1389         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1390         /* Now call the callback function of flushed requests */
1391 restart_cb:
1392         list_for_each_entry_safe(cqr, n, &flush_queue, list) {
1393                 if (cqr->status == DASD_CQR_CLEAR) {
1394                         /* wait for clear interrupt! */
1395                         wait_event(dasd_flush_wq, _wait_for_clear(cqr));
1396                         cqr->status = DASD_CQR_FAILED;
1397                 }
1398                 /* Process finished ERP request. */
1399                 if (cqr->refers) {
1400                         __dasd_process_erp(device, cqr);
1401                         /* restart list_for_xx loop since dasd_process_erp
1402                          * might remove multiple elements */
1403                         goto restart_cb;
1404                 }
1405                 /* call the callback function */
1406                 cqr->endclk = get_clock();
1407                 if (cqr->callback != NULL)
1408                         (cqr->callback)(cqr, cqr->callback_data);
1409         }
1410         return rc;
1411 }
1412
1413 /*
1414  * Acquire the device lock and process queues for the device.
1415  */
1416 static void
1417 dasd_tasklet(struct dasd_device * device)
1418 {
1419         struct list_head final_queue;
1420         struct list_head *l, *n;
1421         struct dasd_ccw_req *cqr;
1422
1423         atomic_set (&device->tasklet_scheduled, 0);
1424         INIT_LIST_HEAD(&final_queue);
1425         spin_lock_irq(get_ccwdev_lock(device->cdev));
1426         /* Check expire time of first request on the ccw queue. */
1427         __dasd_check_expire(device);
1428         /* Finish off requests on ccw queue */
1429         __dasd_process_ccw_queue(device, &final_queue);
1430         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1431         /* Now call the callback function of requests with final status */
1432         list_for_each_safe(l, n, &final_queue) {
1433                 cqr = list_entry(l, struct dasd_ccw_req, list);
1434                 list_del_init(&cqr->list);
1435                 if (cqr->callback != NULL)
1436                         (cqr->callback)(cqr, cqr->callback_data);
1437         }
1438         spin_lock_irq(&device->request_queue_lock);
1439         spin_lock(get_ccwdev_lock(device->cdev));
1440         /* Get new request from the block device request queue */
1441         __dasd_process_blk_queue(device);
1442         /* Now check if the head of the ccw queue needs to be started. */
1443         __dasd_start_head(device);
1444         spin_unlock(get_ccwdev_lock(device->cdev));
1445         spin_unlock_irq(&device->request_queue_lock);
1446         dasd_put_device(device);
1447 }
1448
1449 /*
1450  * Schedules a call to dasd_tasklet over the device tasklet.
1451  */
1452 void
1453 dasd_schedule_bh(struct dasd_device * device)
1454 {
1455         /* Protect against rescheduling. */
1456         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
1457                 return;
1458         dasd_get_device(device);
1459         tasklet_hi_schedule(&device->tasklet);
1460 }
1461
1462 /*
1463  * Queue a request to the head of the ccw_queue. Start the I/O if
1464  * possible.
1465  */
1466 void
1467 dasd_add_request_head(struct dasd_ccw_req *req)
1468 {
1469         struct dasd_device *device;
1470         unsigned long flags;
1471
1472         device = req->device;
1473         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1474         req->status = DASD_CQR_QUEUED;
1475         req->device = device;
1476         list_add(&req->list, &device->ccw_queue);
1477         /* let the bh start the request to keep them in order */
1478         dasd_schedule_bh(device);
1479         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1480 }
1481
1482 /*
1483  * Queue a request to the tail of the ccw_queue. Start the I/O if
1484  * possible.
1485  */
1486 void
1487 dasd_add_request_tail(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_tail(&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  * Wakeup callback.
1504  */
1505 static void
1506 dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
1507 {
1508         wake_up((wait_queue_head_t *) data);
1509 }
1510
1511 static inline int
1512 _wait_for_wakeup(struct dasd_ccw_req *cqr)
1513 {
1514         struct dasd_device *device;
1515         int rc;
1516
1517         device = cqr->device;
1518         spin_lock_irq(get_ccwdev_lock(device->cdev));
1519         rc = ((cqr->status == DASD_CQR_DONE ||
1520                cqr->status == DASD_CQR_FAILED) &&
1521               list_empty(&cqr->list));
1522         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1523         return rc;
1524 }
1525
1526 /*
1527  * Attempts to start a special ccw queue and waits for its completion.
1528  */
1529 int
1530 dasd_sleep_on(struct dasd_ccw_req * cqr)
1531 {
1532         wait_queue_head_t wait_q;
1533         struct dasd_device *device;
1534         int rc;
1535
1536         device = cqr->device;
1537         spin_lock_irq(get_ccwdev_lock(device->cdev));
1538
1539         init_waitqueue_head (&wait_q);
1540         cqr->callback = dasd_wakeup_cb;
1541         cqr->callback_data = (void *) &wait_q;
1542         cqr->status = DASD_CQR_QUEUED;
1543         list_add_tail(&cqr->list, &device->ccw_queue);
1544
1545         /* let the bh start the request to keep them in order */
1546         dasd_schedule_bh(device);
1547
1548         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1549
1550         wait_event(wait_q, _wait_for_wakeup(cqr));
1551
1552         /* Request status is either done or failed. */
1553         rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1554         return rc;
1555 }
1556
1557 /*
1558  * Attempts to start a special ccw queue and wait interruptible
1559  * for its completion.
1560  */
1561 int
1562 dasd_sleep_on_interruptible(struct dasd_ccw_req * cqr)
1563 {
1564         wait_queue_head_t wait_q;
1565         struct dasd_device *device;
1566         int rc, finished;
1567
1568         device = cqr->device;
1569         spin_lock_irq(get_ccwdev_lock(device->cdev));
1570
1571         init_waitqueue_head (&wait_q);
1572         cqr->callback = dasd_wakeup_cb;
1573         cqr->callback_data = (void *) &wait_q;
1574         cqr->status = DASD_CQR_QUEUED;
1575         list_add_tail(&cqr->list, &device->ccw_queue);
1576
1577         /* let the bh start the request to keep them in order */
1578         dasd_schedule_bh(device);
1579         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1580
1581         finished = 0;
1582         while (!finished) {
1583                 rc = wait_event_interruptible(wait_q, _wait_for_wakeup(cqr));
1584                 if (rc != -ERESTARTSYS) {
1585                         /* Request is final (done or failed) */
1586                         rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO;
1587                         break;
1588                 }
1589                 spin_lock_irq(get_ccwdev_lock(device->cdev));
1590                 switch (cqr->status) {
1591                 case DASD_CQR_IN_IO:
1592                         /* terminate runnig cqr */
1593                         if (device->discipline->term_IO) {
1594                                 cqr->retries = -1;
1595                                 device->discipline->term_IO(cqr);
1596                                 /* wait (non-interruptible) for final status
1597                                  * because signal ist still pending */
1598                                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1599                                 wait_event(wait_q, _wait_for_wakeup(cqr));
1600                                 spin_lock_irq(get_ccwdev_lock(device->cdev));
1601                                 rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO;
1602                                 finished = 1;
1603                         }
1604                         break;
1605                 case DASD_CQR_QUEUED:
1606                         /* request  */
1607                         list_del_init(&cqr->list);
1608                         rc = -EIO;
1609                         finished = 1;
1610                         break;
1611                 default:
1612                         /* cqr with 'non-interruptable' status - just wait */
1613                         break;
1614                 }
1615                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1616         }
1617         return rc;
1618 }
1619
1620 /*
1621  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
1622  * for eckd devices) the currently running request has to be terminated
1623  * and be put back to status queued, before the special request is added
1624  * to the head of the queue. Then the special request is waited on normally.
1625  */
1626 static inline int
1627 _dasd_term_running_cqr(struct dasd_device *device)
1628 {
1629         struct dasd_ccw_req *cqr;
1630
1631         if (list_empty(&device->ccw_queue))
1632                 return 0;
1633         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1634         return device->discipline->term_IO(cqr);
1635 }
1636
1637 int
1638 dasd_sleep_on_immediatly(struct dasd_ccw_req * cqr)
1639 {
1640         wait_queue_head_t wait_q;
1641         struct dasd_device *device;
1642         int rc;
1643
1644         device = cqr->device;
1645         spin_lock_irq(get_ccwdev_lock(device->cdev));
1646         rc = _dasd_term_running_cqr(device);
1647         if (rc) {
1648                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1649                 return rc;
1650         }
1651
1652         init_waitqueue_head (&wait_q);
1653         cqr->callback = dasd_wakeup_cb;
1654         cqr->callback_data = (void *) &wait_q;
1655         cqr->status = DASD_CQR_QUEUED;
1656         list_add(&cqr->list, &device->ccw_queue);
1657
1658         /* let the bh start the request to keep them in order */
1659         dasd_schedule_bh(device);
1660
1661         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1662
1663         wait_event(wait_q, _wait_for_wakeup(cqr));
1664
1665         /* Request status is either done or failed. */
1666         rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1667         return rc;
1668 }
1669
1670 /*
1671  * Cancels a request that was started with dasd_sleep_on_req.
1672  * This is useful to timeout requests. The request will be
1673  * terminated if it is currently in i/o.
1674  * Returns 1 if the request has been terminated.
1675  */
1676 int
1677 dasd_cancel_req(struct dasd_ccw_req *cqr)
1678 {
1679         struct dasd_device *device = cqr->device;
1680         unsigned long flags;
1681         int rc;
1682
1683         rc = 0;
1684         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1685         switch (cqr->status) {
1686         case DASD_CQR_QUEUED:
1687                 /* request was not started - just set to failed */
1688                 cqr->status = DASD_CQR_FAILED;
1689                 break;
1690         case DASD_CQR_IN_IO:
1691                 /* request in IO - terminate IO and release again */
1692                 if (device->discipline->term_IO(cqr) != 0)
1693                         /* what to do if unable to terminate ??????
1694                            e.g. not _IN_IO */
1695                         cqr->status = DASD_CQR_FAILED;
1696                 cqr->stopclk = get_clock();
1697                 rc = 1;
1698                 break;
1699         case DASD_CQR_DONE:
1700         case DASD_CQR_FAILED:
1701                 /* already finished - do nothing */
1702                 break;
1703         default:
1704                 DEV_MESSAGE(KERN_ALERT, device,
1705                             "invalid status %02x in request",
1706                             cqr->status);
1707                 BUG();
1708
1709         }
1710         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1711         dasd_schedule_bh(device);
1712         return rc;
1713 }
1714
1715 /*
1716  * SECTION: Block device operations (request queue, partitions, open, release).
1717  */
1718
1719 /*
1720  * Dasd request queue function. Called from ll_rw_blk.c
1721  */
1722 static void
1723 do_dasd_request(request_queue_t * queue)
1724 {
1725         struct dasd_device *device;
1726
1727         device = (struct dasd_device *) queue->queuedata;
1728         spin_lock(get_ccwdev_lock(device->cdev));
1729         /* Get new request from the block device request queue */
1730         __dasd_process_blk_queue(device);
1731         /* Now check if the head of the ccw queue needs to be started. */
1732         __dasd_start_head(device);
1733         spin_unlock(get_ccwdev_lock(device->cdev));
1734 }
1735
1736 /*
1737  * Allocate and initialize request queue and default I/O scheduler.
1738  */
1739 static int
1740 dasd_alloc_queue(struct dasd_device * device)
1741 {
1742         int rc;
1743
1744         device->request_queue = blk_init_queue(do_dasd_request,
1745                                                &device->request_queue_lock);
1746         if (device->request_queue == NULL)
1747                 return -ENOMEM;
1748
1749         device->request_queue->queuedata = device;
1750
1751         elevator_exit(device->request_queue->elevator);
1752         rc = elevator_init(device->request_queue, "deadline");
1753         if (rc) {
1754                 blk_cleanup_queue(device->request_queue);
1755                 return rc;
1756         }
1757         return 0;
1758 }
1759
1760 /*
1761  * Allocate and initialize request queue.
1762  */
1763 static void
1764 dasd_setup_queue(struct dasd_device * device)
1765 {
1766         int max;
1767
1768         blk_queue_hardsect_size(device->request_queue, device->bp_block);
1769         max = device->discipline->max_blocks << device->s2b_shift;
1770         blk_queue_max_sectors(device->request_queue, max);
1771         blk_queue_max_phys_segments(device->request_queue, -1L);
1772         blk_queue_max_hw_segments(device->request_queue, -1L);
1773         blk_queue_max_segment_size(device->request_queue, -1L);
1774         blk_queue_segment_boundary(device->request_queue, -1L);
1775         blk_queue_ordered(device->request_queue, QUEUE_ORDERED_TAG, NULL);
1776 }
1777
1778 /*
1779  * Deactivate and free request queue.
1780  */
1781 static void
1782 dasd_free_queue(struct dasd_device * device)
1783 {
1784         if (device->request_queue) {
1785                 blk_cleanup_queue(device->request_queue);
1786                 device->request_queue = NULL;
1787         }
1788 }
1789
1790 /*
1791  * Flush request on the request queue.
1792  */
1793 static void
1794 dasd_flush_request_queue(struct dasd_device * device)
1795 {
1796         struct request *req;
1797
1798         if (!device->request_queue)
1799                 return;
1800
1801         spin_lock_irq(&device->request_queue_lock);
1802         while ((req = elv_next_request(device->request_queue))) {
1803                 blkdev_dequeue_request(req);
1804                 dasd_end_request(req, 0);
1805         }
1806         spin_unlock_irq(&device->request_queue_lock);
1807 }
1808
1809 static int
1810 dasd_open(struct inode *inp, struct file *filp)
1811 {
1812         struct gendisk *disk = inp->i_bdev->bd_disk;
1813         struct dasd_device *device = disk->private_data;
1814         int rc;
1815
1816         atomic_inc(&device->open_count);
1817         if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1818                 rc = -ENODEV;
1819                 goto unlock;
1820         }
1821
1822         if (!try_module_get(device->discipline->owner)) {
1823                 rc = -EINVAL;
1824                 goto unlock;
1825         }
1826
1827         if (dasd_probeonly) {
1828                 DEV_MESSAGE(KERN_INFO, device, "%s",
1829                             "No access to device due to probeonly mode");
1830                 rc = -EPERM;
1831                 goto out;
1832         }
1833
1834         if (device->state <= DASD_STATE_BASIC) {
1835                 DBF_DEV_EVENT(DBF_ERR, device, " %s",
1836                               " Cannot open unrecognized device");
1837                 rc = -ENODEV;
1838                 goto out;
1839         }
1840
1841         return 0;
1842
1843 out:
1844         module_put(device->discipline->owner);
1845 unlock:
1846         atomic_dec(&device->open_count);
1847         return rc;
1848 }
1849
1850 static int
1851 dasd_release(struct inode *inp, struct file *filp)
1852 {
1853         struct gendisk *disk = inp->i_bdev->bd_disk;
1854         struct dasd_device *device = disk->private_data;
1855
1856         atomic_dec(&device->open_count);
1857         module_put(device->discipline->owner);
1858         return 0;
1859 }
1860
1861 /*
1862  * Return disk geometry.
1863  */
1864 static int
1865 dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
1866 {
1867         struct dasd_device *device;
1868
1869         device = bdev->bd_disk->private_data;
1870         if (!device)
1871                 return -ENODEV;
1872
1873         if (!device->discipline ||
1874             !device->discipline->fill_geometry)
1875                 return -EINVAL;
1876
1877         device->discipline->fill_geometry(device, geo);
1878         geo->start = get_start_sect(bdev) >> device->s2b_shift;
1879         return 0;
1880 }
1881
1882 struct block_device_operations
1883 dasd_device_operations = {
1884         .owner          = THIS_MODULE,
1885         .open           = dasd_open,
1886         .release        = dasd_release,
1887         .ioctl          = dasd_ioctl,
1888         .compat_ioctl   = dasd_compat_ioctl,
1889         .getgeo         = dasd_getgeo,
1890 };
1891
1892
1893 static void
1894 dasd_exit(void)
1895 {
1896 #ifdef CONFIG_PROC_FS
1897         dasd_proc_exit();
1898 #endif
1899         dasd_eer_exit();
1900         if (dasd_page_cache != NULL) {
1901                 kmem_cache_destroy(dasd_page_cache);
1902                 dasd_page_cache = NULL;
1903         }
1904         dasd_gendisk_exit();
1905         dasd_devmap_exit();
1906         if (dasd_debug_area != NULL) {
1907                 debug_unregister(dasd_debug_area);
1908                 dasd_debug_area = NULL;
1909         }
1910 }
1911
1912 /*
1913  * SECTION: common functions for ccw_driver use
1914  */
1915
1916 /*
1917  * Initial attempt at a probe function. this can be simplified once
1918  * the other detection code is gone.
1919  */
1920 int
1921 dasd_generic_probe (struct ccw_device *cdev,
1922                     struct dasd_discipline *discipline)
1923 {
1924         int ret;
1925
1926         ret = ccw_device_set_options(cdev, CCWDEV_DO_PATHGROUP);
1927         if (ret) {
1928                 printk(KERN_WARNING
1929                        "dasd_generic_probe: could not set ccw-device options "
1930                        "for %s\n", cdev->dev.bus_id);
1931                 return ret;
1932         }
1933         ret = dasd_add_sysfs_files(cdev);
1934         if (ret) {
1935                 printk(KERN_WARNING
1936                        "dasd_generic_probe: could not add sysfs entries "
1937                        "for %s\n", cdev->dev.bus_id);
1938                 return ret;
1939         }
1940         cdev->handler = &dasd_int_handler;
1941
1942         /*
1943          * Automatically online either all dasd devices (dasd_autodetect)
1944          * or all devices specified with dasd= parameters during
1945          * initial probe.
1946          */
1947         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
1948             (dasd_autodetect && dasd_busid_known(cdev->dev.bus_id) != 0))
1949                 ret = ccw_device_set_online(cdev);
1950         if (ret)
1951                 printk(KERN_WARNING
1952                        "dasd_generic_probe: could not initially online "
1953                        "ccw-device %s\n", cdev->dev.bus_id);
1954         return ret;
1955 }
1956
1957 /*
1958  * This will one day be called from a global not_oper handler.
1959  * It is also used by driver_unregister during module unload.
1960  */
1961 void
1962 dasd_generic_remove (struct ccw_device *cdev)
1963 {
1964         struct dasd_device *device;
1965
1966         cdev->handler = NULL;
1967
1968         dasd_remove_sysfs_files(cdev);
1969         device = dasd_device_from_cdev(cdev);
1970         if (IS_ERR(device))
1971                 return;
1972         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1973                 /* Already doing offline processing */
1974                 dasd_put_device(device);
1975                 return;
1976         }
1977         /*
1978          * This device is removed unconditionally. Set offline
1979          * flag to prevent dasd_open from opening it while it is
1980          * no quite down yet.
1981          */
1982         dasd_set_target_state(device, DASD_STATE_NEW);
1983         /* dasd_delete_device destroys the device reference. */
1984         dasd_delete_device(device);
1985 }
1986
1987 /*
1988  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
1989  * the device is detected for the first time and is supposed to be used
1990  * or the user has started activation through sysfs.
1991  */
1992 int
1993 dasd_generic_set_online (struct ccw_device *cdev,
1994                          struct dasd_discipline *base_discipline)
1995
1996 {
1997         struct dasd_discipline *discipline;
1998         struct dasd_device *device;
1999         int rc;
2000
2001         /* first online clears initial online feature flag */
2002         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
2003         device = dasd_create_device(cdev);
2004         if (IS_ERR(device))
2005                 return PTR_ERR(device);
2006
2007         discipline = base_discipline;
2008         if (device->features & DASD_FEATURE_USEDIAG) {
2009                 if (!dasd_diag_discipline_pointer) {
2010                         printk (KERN_WARNING
2011                                 "dasd_generic couldn't online device %s "
2012                                 "- discipline DIAG not available\n",
2013                                 cdev->dev.bus_id);
2014                         dasd_delete_device(device);
2015                         return -ENODEV;
2016                 }
2017                 discipline = dasd_diag_discipline_pointer;
2018         }
2019         if (!try_module_get(base_discipline->owner)) {
2020                 dasd_delete_device(device);
2021                 return -EINVAL;
2022         }
2023         if (!try_module_get(discipline->owner)) {
2024                 module_put(base_discipline->owner);
2025                 dasd_delete_device(device);
2026                 return -EINVAL;
2027         }
2028         device->base_discipline = base_discipline;
2029         device->discipline = discipline;
2030
2031         rc = discipline->check_device(device);
2032         if (rc) {
2033                 printk (KERN_WARNING
2034                         "dasd_generic couldn't online device %s "
2035                         "with discipline %s rc=%i\n",
2036                         cdev->dev.bus_id, discipline->name, rc);
2037                 module_put(discipline->owner);
2038                 module_put(base_discipline->owner);
2039                 dasd_delete_device(device);
2040                 return rc;
2041         }
2042
2043         dasd_set_target_state(device, DASD_STATE_ONLINE);
2044         if (device->state <= DASD_STATE_KNOWN) {
2045                 printk (KERN_WARNING
2046                         "dasd_generic discipline not found for %s\n",
2047                         cdev->dev.bus_id);
2048                 rc = -ENODEV;
2049                 dasd_set_target_state(device, DASD_STATE_NEW);
2050                 dasd_delete_device(device);
2051         } else
2052                 pr_debug("dasd_generic device %s found\n",
2053                                 cdev->dev.bus_id);
2054
2055         /* FIXME: we have to wait for the root device but we don't want
2056          * to wait for each single device but for all at once. */
2057         wait_event(dasd_init_waitq, _wait_for_device(device));
2058
2059         dasd_put_device(device);
2060
2061         return rc;
2062 }
2063
2064 int
2065 dasd_generic_set_offline (struct ccw_device *cdev)
2066 {
2067         struct dasd_device *device;
2068         int max_count, open_count;
2069
2070         device = dasd_device_from_cdev(cdev);
2071         if (IS_ERR(device))
2072                 return PTR_ERR(device);
2073         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
2074                 /* Already doing offline processing */
2075                 dasd_put_device(device);
2076                 return 0;
2077         }
2078         /*
2079          * We must make sure that this device is currently not in use.
2080          * The open_count is increased for every opener, that includes
2081          * the blkdev_get in dasd_scan_partitions. We are only interested
2082          * in the other openers.
2083          */
2084         max_count = device->bdev ? 0 : -1;
2085         open_count = (int) atomic_read(&device->open_count);
2086         if (open_count > max_count) {
2087                 if (open_count > 0)
2088                         printk (KERN_WARNING "Can't offline dasd device with "
2089                                 "open count = %i.\n",
2090                                 open_count);
2091                 else
2092                         printk (KERN_WARNING "%s",
2093                                 "Can't offline dasd device due to internal "
2094                                 "use\n");
2095                 clear_bit(DASD_FLAG_OFFLINE, &device->flags);
2096                 dasd_put_device(device);
2097                 return -EBUSY;
2098         }
2099         dasd_set_target_state(device, DASD_STATE_NEW);
2100         /* dasd_delete_device destroys the device reference. */
2101         dasd_delete_device(device);
2102
2103         return 0;
2104 }
2105
2106 int
2107 dasd_generic_notify(struct ccw_device *cdev, int event)
2108 {
2109         struct dasd_device *device;
2110         struct dasd_ccw_req *cqr;
2111         unsigned long flags;
2112         int ret;
2113
2114         device = dasd_device_from_cdev(cdev);
2115         if (IS_ERR(device))
2116                 return 0;
2117         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
2118         ret = 0;
2119         switch (event) {
2120         case CIO_GONE:
2121         case CIO_NO_PATH:
2122                 /* First of all call extended error reporting. */
2123                 dasd_eer_write(device, NULL, DASD_EER_NOPATH);
2124
2125                 if (device->state < DASD_STATE_BASIC)
2126                         break;
2127                 /* Device is active. We want to keep it. */
2128                 if (test_bit(DASD_FLAG_DSC_ERROR, &device->flags)) {
2129                         list_for_each_entry(cqr, &device->ccw_queue, list)
2130                                 if (cqr->status == DASD_CQR_IN_IO)
2131                                         cqr->status = DASD_CQR_FAILED;
2132                         device->stopped |= DASD_STOPPED_DC_EIO;
2133                 } else {
2134                         list_for_each_entry(cqr, &device->ccw_queue, list)
2135                                 if (cqr->status == DASD_CQR_IN_IO) {
2136                                         cqr->status = DASD_CQR_QUEUED;
2137                                         cqr->retries++;
2138                                 }
2139                         device->stopped |= DASD_STOPPED_DC_WAIT;
2140                         dasd_set_timer(device, 0);
2141                 }
2142                 dasd_schedule_bh(device);
2143                 ret = 1;
2144                 break;
2145         case CIO_OPER:
2146                 /* FIXME: add a sanity check. */
2147                 device->stopped &= ~(DASD_STOPPED_DC_WAIT|DASD_STOPPED_DC_EIO);
2148                 dasd_schedule_bh(device);
2149                 ret = 1;
2150                 break;
2151         }
2152         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
2153         dasd_put_device(device);
2154         return ret;
2155 }
2156
2157
2158 static int __init
2159 dasd_init(void)
2160 {
2161         int rc;
2162
2163         init_waitqueue_head(&dasd_init_waitq);
2164         init_waitqueue_head(&dasd_flush_wq);
2165
2166         /* register 'common' DASD debug area, used for all DBF_XXX calls */
2167         dasd_debug_area = debug_register("dasd", 1, 2, 8 * sizeof (long));
2168         if (dasd_debug_area == NULL) {
2169                 rc = -ENOMEM;
2170                 goto failed;
2171         }
2172         debug_register_view(dasd_debug_area, &debug_sprintf_view);
2173         debug_set_level(dasd_debug_area, DBF_WARNING);
2174
2175         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
2176
2177         dasd_diag_discipline_pointer = NULL;
2178
2179         rc = dasd_devmap_init();
2180         if (rc)
2181                 goto failed;
2182         rc = dasd_gendisk_init();
2183         if (rc)
2184                 goto failed;
2185         rc = dasd_parse();
2186         if (rc)
2187                 goto failed;
2188         rc = dasd_eer_init();
2189         if (rc)
2190                 goto failed;
2191 #ifdef CONFIG_PROC_FS
2192         rc = dasd_proc_init();
2193         if (rc)
2194                 goto failed;
2195 #endif
2196
2197         return 0;
2198 failed:
2199         MESSAGE(KERN_INFO, "%s", "initialization not performed due to errors");
2200         dasd_exit();
2201         return rc;
2202 }
2203
2204 module_init(dasd_init);
2205 module_exit(dasd_exit);
2206
2207 EXPORT_SYMBOL(dasd_debug_area);
2208 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
2209
2210 EXPORT_SYMBOL(dasd_add_request_head);
2211 EXPORT_SYMBOL(dasd_add_request_tail);
2212 EXPORT_SYMBOL(dasd_cancel_req);
2213 EXPORT_SYMBOL(dasd_clear_timer);
2214 EXPORT_SYMBOL(dasd_enable_device);
2215 EXPORT_SYMBOL(dasd_int_handler);
2216 EXPORT_SYMBOL(dasd_kfree_request);
2217 EXPORT_SYMBOL(dasd_kick_device);
2218 EXPORT_SYMBOL(dasd_kmalloc_request);
2219 EXPORT_SYMBOL(dasd_schedule_bh);
2220 EXPORT_SYMBOL(dasd_set_target_state);
2221 EXPORT_SYMBOL(dasd_set_timer);
2222 EXPORT_SYMBOL(dasd_sfree_request);
2223 EXPORT_SYMBOL(dasd_sleep_on);
2224 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2225 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2226 EXPORT_SYMBOL(dasd_smalloc_request);
2227 EXPORT_SYMBOL(dasd_start_IO);
2228 EXPORT_SYMBOL(dasd_term_IO);
2229
2230 EXPORT_SYMBOL_GPL(dasd_generic_probe);
2231 EXPORT_SYMBOL_GPL(dasd_generic_remove);
2232 EXPORT_SYMBOL_GPL(dasd_generic_notify);
2233 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
2234 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
2235