drivers/s390/block/dasd.c

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