drivers/s390/block/dasd_fba.c

   1 /*
   2  * File...........: linux/drivers/s390/block/dasd_fba.c
   3  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
   4  * Bugreports.to..: <Linux390@de.ibm.com>
   5  * Copyright IBM Corp. 1999, 2009
   6  */
   7
   8 #define KMSG_COMPONENT "dasd-fba"
   9
  10 #include <linux/stddef.h>
  11 #include <linux/kernel.h>
  12 #include <asm/debug.h>
  13
  14 #include <linux/slab.h>
  15 #include <linux/hdreg.h>        /* HDIO_GETGEO                      */
  16 #include <linux/bio.h>
  17 #include <linux/module.h>
  18 #include <linux/init.h>
  19
  20 #include <asm/idals.h>
  21 #include <asm/ebcdic.h>
  22 #include <asm/io.h>
  23 #include <asm/ccwdev.h>
  24
  25 #include "dasd_int.h"
  26 #include "dasd_fba.h"
  27
  28 #ifdef PRINTK_HEADER
  29 #undef PRINTK_HEADER
  30 #endif                          /* PRINTK_HEADER */
  31 #define PRINTK_HEADER "dasd(fba):"
  32
  33 #define DASD_FBA_CCW_WRITE 0x41
  34 #define DASD_FBA_CCW_READ 0x42
  35 #define DASD_FBA_CCW_LOCATE 0x43
  36 #define DASD_FBA_CCW_DEFINE_EXTENT 0x63
  37
  38 MODULE_LICENSE("GPL");
  39
  40 static struct dasd_discipline dasd_fba_discipline;
  41
  42 struct dasd_fba_private {
  43         struct dasd_fba_characteristics rdc_data;
  44 };
  45
  46 static struct ccw_device_id dasd_fba_ids[] = {
  47         { CCW_DEVICE_DEVTYPE (0x6310, 0, 0x9336, 0), .driver_info = 0x1},
  48         { CCW_DEVICE_DEVTYPE (0x3880, 0, 0x3370, 0), .driver_info = 0x2},
  49         { /* end of list */ },
  50 };
  51
  52 MODULE_DEVICE_TABLE(ccw, dasd_fba_ids);
  53
  54 static struct ccw_driver dasd_fba_driver; /* see below */
  55 static int
  56 dasd_fba_probe(struct ccw_device *cdev)
  57 {
  58         return dasd_generic_probe(cdev, &dasd_fba_discipline);
  59 }
  60
  61 static int
  62 dasd_fba_set_online(struct ccw_device *cdev)
  63 {
  64         return dasd_generic_set_online(cdev, &dasd_fba_discipline);
  65 }
  66
  67 static struct ccw_driver dasd_fba_driver = {
  68         .driver = {
  69                 .name   = "dasd-fba",
  70                 .owner  = THIS_MODULE,
  71         },
  72         .ids         = dasd_fba_ids,
  73         .probe       = dasd_fba_probe,
  74         .remove      = dasd_generic_remove,
  75         .set_offline = dasd_generic_set_offline,
  76         .set_online  = dasd_fba_set_online,
  77         .notify      = dasd_generic_notify,
  78         .path_event  = dasd_generic_path_event,
  79         .freeze      = dasd_generic_pm_freeze,
  80         .thaw        = dasd_generic_restore_device,
  81         .restore     = dasd_generic_restore_device,
  82         .int_class   = IOINT_DAS,
  83 };
  84
  85 static void
  86 define_extent(struct ccw1 * ccw, struct DE_fba_data *data, int rw,
  87               int blksize, int beg, int nr)
  88 {
  89         ccw->cmd_code = DASD_FBA_CCW_DEFINE_EXTENT;
  90         ccw->flags = 0;
  91         ccw->count = 16;
  92         ccw->cda = (__u32) __pa(data);
  93         memset(data, 0, sizeof (struct DE_fba_data));
  94         if (rw == WRITE)
  95                 (data->mask).perm = 0x0;
  96         else if (rw == READ)
  97                 (data->mask).perm = 0x1;
  98         else
  99                 data->mask.perm = 0x2;
 100         data->blk_size = blksize;
 101         data->ext_loc = beg;
 102         data->ext_end = nr - 1;
 103 }
 104
 105 static void
 106 locate_record(struct ccw1 * ccw, struct LO_fba_data *data, int rw,
 107               int block_nr, int block_ct)
 108 {
 109         ccw->cmd_code = DASD_FBA_CCW_LOCATE;
 110         ccw->flags = 0;
 111         ccw->count = 8;
 112         ccw->cda = (__u32) __pa(data);
 113         memset(data, 0, sizeof (struct LO_fba_data));
 114         if (rw == WRITE)
 115                 data->operation.cmd = 0x5;
 116         else if (rw == READ)
 117                 data->operation.cmd = 0x6;
 118         else
 119                 data->operation.cmd = 0x8;
 120         data->blk_nr = block_nr;
 121         data->blk_ct = block_ct;
 122 }
 123
 124 static int
 125 dasd_fba_check_characteristics(struct dasd_device *device)
 126 {
 127         struct dasd_block *block;
 128         struct dasd_fba_private *private;
 129         struct ccw_device *cdev = device->cdev;
 130         int rc;
 131         int readonly;
 132
 133         private = (struct dasd_fba_private *) device->private;
 134         if (!private) {
 135                 private = kzalloc(sizeof(*private), GFP_KERNEL | GFP_DMA);
 136                 if (!private) {
 137                         dev_warn(&device->cdev->dev,
 138                                  "Allocating memory for private DASD "
 139                                  "data failed\n");
 140                         return -ENOMEM;
 141                 }
 142                 device->private = (void *) private;
 143         } else {
 144                 memset(private, 0, sizeof(*private));
 145         }
 146         block = dasd_alloc_block();
 147         if (IS_ERR(block)) {
 148                 DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s", "could not allocate "
 149                                 "dasd block structure");
 150                 device->private = NULL;
 151                 kfree(private);
 152                 return PTR_ERR(block);
 153         }
 154         device->block = block;
 155         block->base = device;
 156
 157         /* Read Device Characteristics */
 158         rc = dasd_generic_read_dev_chars(device, DASD_FBA_MAGIC,
 159                                          &private->rdc_data, 32);
 160         if (rc) {
 161                 DBF_EVENT_DEVID(DBF_WARNING, cdev, "Read device "
 162                                 "characteristics returned error %d", rc);
 163                 device->block = NULL;
 164                 dasd_free_block(block);
 165                 device->private = NULL;
 166                 kfree(private);
 167                 return rc;
 168         }
 169
 170         device->default_expires = DASD_EXPIRES;
 171         device->path_data.opm = LPM_ANYPATH;
 172
 173         readonly = dasd_device_is_ro(device);
 174         if (readonly)
 175                 set_bit(DASD_FLAG_DEVICE_RO, &device->flags);
 176
 177         dev_info(&device->cdev->dev,
 178                  "New FBA DASD %04X/%02X (CU %04X/%02X) with %d MB "
 179                  "and %d B/blk%s\n",
 180                  cdev->id.dev_type,
 181                  cdev->id.dev_model,
 182                  cdev->id.cu_type,
 183                  cdev->id.cu_model,
 184                  ((private->rdc_data.blk_bdsa *
 185                    (private->rdc_data.blk_size >> 9)) >> 11),
 186                  private->rdc_data.blk_size,
 187                  readonly ? ", read-only device" : "");
 188         return 0;
 189 }
 190
 191 static int dasd_fba_do_analysis(struct dasd_block *block)
 192 {
 193         struct dasd_fba_private *private;
 194         int sb, rc;
 195
 196         private = (struct dasd_fba_private *) block->base->private;
 197         rc = dasd_check_blocksize(private->rdc_data.blk_size);
 198         if (rc) {
 199                 DBF_DEV_EVENT(DBF_WARNING, block->base, "unknown blocksize %d",
 200                             private->rdc_data.blk_size);
 201                 return rc;
 202         }
 203         block->blocks = private->rdc_data.blk_bdsa;
 204         block->bp_block = private->rdc_data.blk_size;
 205         block->s2b_shift = 0;   /* bits to shift 512 to get a block */
 206         for (sb = 512; sb < private->rdc_data.blk_size; sb = sb << 1)
 207                 block->s2b_shift++;
 208         return 0;
 209 }
 210
 211 static int dasd_fba_fill_geometry(struct dasd_block *block,
 212                                   struct hd_geometry *geo)
 213 {
 214         if (dasd_check_blocksize(block->bp_block) != 0)
 215                 return -EINVAL;
 216         geo->cylinders = (block->blocks << block->s2b_shift) >> 10;
 217         geo->heads = 16;
 218         geo->sectors = 128 >> block->s2b_shift;
 219         return 0;
 220 }
 221
 222 static dasd_erp_fn_t
 223 dasd_fba_erp_action(struct dasd_ccw_req * cqr)
 224 {
 225         return dasd_default_erp_action;
 226 }
 227
 228 static dasd_erp_fn_t
 229 dasd_fba_erp_postaction(struct dasd_ccw_req * cqr)
 230 {
 231         if (cqr->function == dasd_default_erp_action)
 232                 return dasd_default_erp_postaction;
 233
 234         DBF_DEV_EVENT(DBF_WARNING, cqr->startdev, "unknown ERP action %p",
 235                     cqr->function);
 236         return NULL;
 237 }
 238
 239 static void dasd_fba_check_for_device_change(struct dasd_device *device,
 240                                              struct dasd_ccw_req *cqr,
 241                                              struct irb *irb)
 242 {
 243         char mask;
 244
 245         /* first of all check for state change pending interrupt */
 246         mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP;
 247         if ((irb->scsw.cmd.dstat & mask) == mask)
 248                 dasd_generic_handle_state_change(device);
 249 };
 250
 251 static struct dasd_ccw_req *dasd_fba_build_cp(struct dasd_device * memdev,
 252                                               struct dasd_block *block,
 253                                               struct request *req)
 254 {
 255         struct dasd_fba_private *private;
 256         unsigned long *idaws;
 257         struct LO_fba_data *LO_data;
 258         struct dasd_ccw_req *cqr;
 259         struct ccw1 *ccw;
 260         struct req_iterator iter;
 261         struct bio_vec *bv;
 262         char *dst;
 263         int count, cidaw, cplength, datasize;
 264         sector_t recid, first_rec, last_rec;
 265         unsigned int blksize, off;
 266         unsigned char cmd;
 267
 268         private = (struct dasd_fba_private *) block->base->private;
 269         if (rq_data_dir(req) == READ) {
 270                 cmd = DASD_FBA_CCW_READ;
 271         } else if (rq_data_dir(req) == WRITE) {
 272                 cmd = DASD_FBA_CCW_WRITE;
 273         } else
 274                 return ERR_PTR(-EINVAL);
 275         blksize = block->bp_block;
 276         /* Calculate record id of first and last block. */
 277         first_rec = blk_rq_pos(req) >> block->s2b_shift;
 278         last_rec =
 279                 (blk_rq_pos(req) + blk_rq_sectors(req) - 1) >> block->s2b_shift;
 280         /* Check struct bio and count the number of blocks for the request. */
 281         count = 0;
 282         cidaw = 0;
 283         rq_for_each_segment(bv, req, iter) {
 284                 if (bv->bv_len & (blksize - 1))
 285                         /* Fba can only do full blocks. */
 286                         return ERR_PTR(-EINVAL);
 287                 count += bv->bv_len >> (block->s2b_shift + 9);
 288 #if defined(CONFIG_64BIT)
 289                 if (idal_is_needed (page_address(bv->bv_page), bv->bv_len))
 290                         cidaw += bv->bv_len / blksize;
 291 #endif
 292         }
 293         /* Paranoia. */
 294         if (count != last_rec - first_rec + 1)
 295                 return ERR_PTR(-EINVAL);
 296         /* 1x define extent + 1x locate record + number of blocks */
 297         cplength = 2 + count;
 298         /* 1x define extent + 1x locate record */
 299         datasize = sizeof(struct DE_fba_data) + sizeof(struct LO_fba_data) +
 300                 cidaw * sizeof(unsigned long);
 301         /*
 302          * Find out number of additional locate record ccws if the device
 303          * can't do data chaining.
 304          */
 305         if (private->rdc_data.mode.bits.data_chain == 0) {
 306                 cplength += count - 1;
 307                 datasize += (count - 1)*sizeof(struct LO_fba_data);
 308         }
 309         /* Allocate the ccw request. */
 310         cqr = dasd_smalloc_request(DASD_FBA_MAGIC, cplength, datasize, memdev);
 311         if (IS_ERR(cqr))
 312                 return cqr;
 313         ccw = cqr->cpaddr;
 314         /* First ccw is define extent. */
 315         define_extent(ccw++, cqr->data, rq_data_dir(req),
 316                       block->bp_block, blk_rq_pos(req), blk_rq_sectors(req));
 317         /* Build locate_record + read/write ccws. */
 318         idaws = (unsigned long *) (cqr->data + sizeof(struct DE_fba_data));
 319         LO_data = (struct LO_fba_data *) (idaws + cidaw);
 320         /* Locate record for all blocks for smart devices. */
 321         if (private->rdc_data.mode.bits.data_chain != 0) {
 322                 ccw[-1].flags |= CCW_FLAG_CC;
 323                 locate_record(ccw++, LO_data++, rq_data_dir(req), 0, count);
 324         }
 325         recid = first_rec;
 326         rq_for_each_segment(bv, req, iter) {
 327                 dst = page_address(bv->bv_page) + bv->bv_offset;
 328                 if (dasd_page_cache) {
 329                         char *copy = kmem_cache_alloc(dasd_page_cache,
 330                                                       GFP_DMA | __GFP_NOWARN);
 331                         if (copy && rq_data_dir(req) == WRITE)
 332                                 memcpy(copy + bv->bv_offset, dst, bv->bv_len);
 333                         if (copy)
 334                                 dst = copy + bv->bv_offset;
 335                 }
 336                 for (off = 0; off < bv->bv_len; off += blksize) {
 337                         /* Locate record for stupid devices. */
 338                         if (private->rdc_data.mode.bits.data_chain == 0) {
 339                                 ccw[-1].flags |= CCW_FLAG_CC;
 340                                 locate_record(ccw, LO_data++,
 341                                               rq_data_dir(req),
 342                                               recid - first_rec, 1);
 343                                 ccw->flags = CCW_FLAG_CC;
 344                                 ccw++;
 345                         } else {
 346                                 if (recid > first_rec)
 347                                         ccw[-1].flags |= CCW_FLAG_DC;
 348                                 else
 349                                         ccw[-1].flags |= CCW_FLAG_CC;
 350                         }
 351                         ccw->cmd_code = cmd;
 352                         ccw->count = block->bp_block;
 353                         if (idal_is_needed(dst, blksize)) {
 354                                 ccw->cda = (__u32)(addr_t) idaws;
 355                                 ccw->flags = CCW_FLAG_IDA;
 356                                 idaws = idal_create_words(idaws, dst, blksize);
 357                         } else {
 358                                 ccw->cda = (__u32)(addr_t) dst;
 359                                 ccw->flags = 0;
 360                         }
 361                         ccw++;
 362                         dst += blksize;
 363                         recid++;
 364                 }
 365         }
 366         if (blk_noretry_request(req) ||
 367             block->base->features & DASD_FEATURE_FAILFAST)
 368                 set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
 369         cqr->startdev = memdev;
 370         cqr->memdev = memdev;
 371         cqr->block = block;
 372         cqr->expires = memdev->default_expires * HZ;    /* default 5 minutes */
 373         cqr->retries = 32;
 374         cqr->buildclk = get_clock();
 375         cqr->status = DASD_CQR_FILLED;
 376         return cqr;
 377 }
 378
 379 static int
 380 dasd_fba_free_cp(struct dasd_ccw_req *cqr, struct request *req)
 381 {
 382         struct dasd_fba_private *private;
 383         struct ccw1 *ccw;
 384         struct req_iterator iter;
 385         struct bio_vec *bv;
 386         char *dst, *cda;
 387         unsigned int blksize, off;
 388         int status;
 389
 390         if (!dasd_page_cache)
 391                 goto out;
 392         private = (struct dasd_fba_private *) cqr->block->base->private;
 393         blksize = cqr->block->bp_block;
 394         ccw = cqr->cpaddr;
 395         /* Skip over define extent & locate record. */
 396         ccw++;
 397         if (private->rdc_data.mode.bits.data_chain != 0)
 398                 ccw++;
 399         rq_for_each_segment(bv, req, iter) {
 400                 dst = page_address(bv->bv_page) + bv->bv_offset;
 401                 for (off = 0; off < bv->bv_len; off += blksize) {
 402                         /* Skip locate record. */
 403                         if (private->rdc_data.mode.bits.data_chain == 0)
 404                                 ccw++;
 405                         if (dst) {
 406                                 if (ccw->flags & CCW_FLAG_IDA)
 407                                         cda = *((char **)((addr_t) ccw->cda));
 408                                 else
 409                                         cda = (char *)((addr_t) ccw->cda);
 410                                 if (dst != cda) {
 411                                         if (rq_data_dir(req) == READ)
 412                                                 memcpy(dst, cda, bv->bv_len);
 413                                         kmem_cache_free(dasd_page_cache,
 414                                             (void *)((addr_t)cda & PAGE_MASK));
 415                                 }
 416                                 dst = NULL;
 417                         }
 418                         ccw++;
 419                 }
 420         }
 421 out:
 422         status = cqr->status == DASD_CQR_DONE;
 423         dasd_sfree_request(cqr, cqr->memdev);
 424         return status;
 425 }
 426
 427 static void dasd_fba_handle_terminated_request(struct dasd_ccw_req *cqr)
 428 {
 429         cqr->status = DASD_CQR_FILLED;
 430 };
 431
 432 static int
 433 dasd_fba_fill_info(struct dasd_device * device,
 434                    struct dasd_information2_t * info)
 435 {
 436         info->label_block = 1;
 437         info->FBA_layout = 1;
 438         info->format = DASD_FORMAT_LDL;
 439         info->characteristics_size = sizeof(struct dasd_fba_characteristics);
 440         memcpy(info->characteristics,
 441                &((struct dasd_fba_private *) device->private)->rdc_data,
 442                sizeof (struct dasd_fba_characteristics));
 443         info->confdata_size = 0;
 444         return 0;
 445 }
 446
 447 static void
 448 dasd_fba_dump_sense_dbf(struct dasd_device *device, struct irb *irb,
 449                         char *reason)
 450 {
 451         u64 *sense;
 452
 453         sense = (u64 *) dasd_get_sense(irb);
 454         if (sense) {
 455                 DBF_DEV_EVENT(DBF_EMERG, device,
 456                               "%s: %s %02x%02x%02x %016llx %016llx %016llx "
 457                               "%016llx", reason,
 458                               scsw_is_tm(&irb->scsw) ? "t" : "c",
 459                               scsw_cc(&irb->scsw), scsw_cstat(&irb->scsw),
 460                               scsw_dstat(&irb->scsw), sense[0], sense[1],
 461                               sense[2], sense[3]);
 462         } else {
 463                 DBF_DEV_EVENT(DBF_EMERG, device, "%s",
 464                               "SORRY - NO VALID SENSE AVAILABLE\n");
 465         }
 466 }
 467
 468
 469 static void
 470 dasd_fba_dump_sense(struct dasd_device *device, struct dasd_ccw_req * req,
 471                     struct irb *irb)
 472 {
 473         char *page;
 474         struct ccw1 *act, *end, *last;
 475         int len, sl, sct, count;
 476
 477         page = (char *) get_zeroed_page(GFP_ATOMIC);
 478         if (page == NULL) {
 479                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
 480                             "No memory to dump sense data");
 481                 return;
 482         }
 483         len = sprintf(page, KERN_ERR PRINTK_HEADER
 484                       " I/O status report for device %s:\n",
 485                       dev_name(&device->cdev->dev));
 486         len += sprintf(page + len, KERN_ERR PRINTK_HEADER
 487                        " in req: %p CS: 0x%02X DS: 0x%02X\n", req,
 488                        irb->scsw.cmd.cstat, irb->scsw.cmd.dstat);
 489         len += sprintf(page + len, KERN_ERR PRINTK_HEADER
 490                        " device %s: Failing CCW: %p\n",
 491                        dev_name(&device->cdev->dev),
 492                        (void *) (addr_t) irb->scsw.cmd.cpa);
 493         if (irb->esw.esw0.erw.cons) {
 494                 for (sl = 0; sl < 4; sl++) {
 495                         len += sprintf(page + len, KERN_ERR PRINTK_HEADER
 496                                        " Sense(hex) %2d-%2d:",
 497                                        (8 * sl), ((8 * sl) + 7));
 498
 499                         for (sct = 0; sct < 8; sct++) {
 500                                 len += sprintf(page + len, " %02x",
 501                                                irb->ecw[8 * sl + sct]);
 502                         }
 503                         len += sprintf(page + len, "\n");
 504                 }
 505         } else {
 506                 len += sprintf(page + len, KERN_ERR PRINTK_HEADER
 507                                " SORRY - NO VALID SENSE AVAILABLE\n");
 508         }
 509         printk(KERN_ERR "%s", page);
 510
 511         /* dump the Channel Program */
 512         /* print first CCWs (maximum 8) */
 513         act = req->cpaddr;
 514         for (last = act; last->flags & (CCW_FLAG_CC | CCW_FLAG_DC); last++);
 515         end = min(act + 8, last);
 516         len = sprintf(page, KERN_ERR PRINTK_HEADER
 517                       " Related CP in req: %p\n", req);
 518         while (act <= end) {
 519                 len += sprintf(page + len, KERN_ERR PRINTK_HEADER
 520                                " CCW %p: %08X %08X DAT:",
 521                                act, ((int *) act)[0], ((int *) act)[1]);
 522                 for (count = 0; count < 32 && count < act->count;
 523                      count += sizeof(int))
 524                         len += sprintf(page + len, " %08X",
 525                                        ((int *) (addr_t) act->cda)
 526                                        [(count>>2)]);
 527                 len += sprintf(page + len, "\n");
 528                 act++;
 529         }
 530         printk(KERN_ERR "%s", page);
 531
 532
 533         /* print failing CCW area */
 534         len = 0;
 535         if (act <  ((struct ccw1 *)(addr_t) irb->scsw.cmd.cpa) - 2) {
 536                 act = ((struct ccw1 *)(addr_t) irb->scsw.cmd.cpa) - 2;
 537                 len += sprintf(page + len, KERN_ERR PRINTK_HEADER "......\n");
 538         }
 539         end = min((struct ccw1 *)(addr_t) irb->scsw.cmd.cpa + 2, last);
 540         while (act <= end) {
 541                 len += sprintf(page + len, KERN_ERR PRINTK_HEADER
 542                                " CCW %p: %08X %08X DAT:",
 543                                act, ((int *) act)[0], ((int *) act)[1]);
 544                 for (count = 0; count < 32 && count < act->count;
 545                      count += sizeof(int))
 546                         len += sprintf(page + len, " %08X",
 547                                        ((int *) (addr_t) act->cda)
 548                                        [(count>>2)]);
 549                 len += sprintf(page + len, "\n");
 550                 act++;
 551         }
 552
 553         /* print last CCWs */
 554         if (act <  last - 2) {
 555                 act = last - 2;
 556                 len += sprintf(page + len, KERN_ERR PRINTK_HEADER "......\n");
 557         }
 558         while (act <= last) {
 559                 len += sprintf(page + len, KERN_ERR PRINTK_HEADER
 560                                " CCW %p: %08X %08X DAT:",
 561                                act, ((int *) act)[0], ((int *) act)[1]);
 562                 for (count = 0; count < 32 && count < act->count;
 563                      count += sizeof(int))
 564                         len += sprintf(page + len, " %08X",
 565                                        ((int *) (addr_t) act->cda)
 566                                        [(count>>2)]);
 567                 len += sprintf(page + len, "\n");
 568                 act++;
 569         }
 570         if (len > 0)
 571                 printk(KERN_ERR "%s", page);
 572         free_page((unsigned long) page);
 573 }
 574
 575 /*
 576  * max_blocks is dependent on the amount of storage that is available
 577  * in the static io buffer for each device. Currently each device has
 578  * 8192 bytes (=2 pages). For 64 bit one dasd_mchunkt_t structure has
 579  * 24 bytes, the struct dasd_ccw_req has 136 bytes and each block can use
 580  * up to 16 bytes (8 for the ccw and 8 for the idal pointer). In
 581  * addition we have one define extent ccw + 16 bytes of data and a
 582  * locate record ccw for each block (stupid devices!) + 16 bytes of data.
 583  * That makes:
 584  * (8192 - 24 - 136 - 8 - 16) / 40 = 200.2 blocks at maximum.
 585  * We want to fit two into the available memory so that we can immediately
 586  * start the next request if one finishes off. That makes 100.1 blocks
 587  * for one request. Give a little safety and the result is 96.
 588  */
 589 static struct dasd_discipline dasd_fba_discipline = {
 590         .owner = THIS_MODULE,
 591         .name = "FBA ",
 592         .ebcname = "FBA ",
 593         .max_blocks = 96,
 594         .check_device = dasd_fba_check_characteristics,
 595         .do_analysis = dasd_fba_do_analysis,
 596         .verify_path = dasd_generic_verify_path,
 597         .fill_geometry = dasd_fba_fill_geometry,
 598         .start_IO = dasd_start_IO,
 599         .term_IO = dasd_term_IO,
 600         .handle_terminated_request = dasd_fba_handle_terminated_request,
 601         .erp_action = dasd_fba_erp_action,
 602         .erp_postaction = dasd_fba_erp_postaction,
 603         .check_for_device_change = dasd_fba_check_for_device_change,
 604         .build_cp = dasd_fba_build_cp,
 605         .free_cp = dasd_fba_free_cp,
 606         .dump_sense = dasd_fba_dump_sense,
 607         .dump_sense_dbf = dasd_fba_dump_sense_dbf,
 608         .fill_info = dasd_fba_fill_info,
 609 };
 610
 611 static int __init
 612 dasd_fba_init(void)
 613 {
 614         int ret;
 615
 616         ASCEBC(dasd_fba_discipline.ebcname, 4);
 617         ret = ccw_driver_register(&dasd_fba_driver);
 618         if (!ret)
 619                 wait_for_device_probe();
 620
 621         return ret;
 622 }
 623
 624 static void __exit
 625 dasd_fba_cleanup(void)
 626 {
 627         ccw_driver_unregister(&dasd_fba_driver);
 628 }
 629
 630 module_init(dasd_fba_init);
 631 module_exit(dasd_fba_cleanup);